From SWODY1 at goshenarc.org Sat Apr 1 00:44:23 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 31 Mar 2006 19:44:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010045 SWODY1 SPC AC 010044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 PM CST FRI MAR 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF MIDDLE TN AND NRN MS/AL... ...OH VALLEY... WELL DEFINED SQUALL LINE HAS FINALLY EMERGED FROM SERN LOWER MI...SWWD INTO SRN IND...AHEAD OF STRONG SHORTWAVE TROUGH. THIS ACTIVITY IS SPREADING EWD AT ROUGHLY 30-35KT AND WILL LIKELY SPREAD ACROSS WRN OH WITH AT LEAST A LARGE HAIL AND DAMAGING WIND THREAT. IN THE ABSENCE OF MEANINGFUL INSTABILITY OVER CENTRAL OH...STRONG CAP AND MEAGER CAPE ON ILN 00Z SOUNDING...LARGE SCALE FORCING WILL AID EWD EXTENT OF CONVECTIVE LINE BUT OVERALL INTENSITY IS EXPECTED TO GRADUALLY DECREASE OVER CNTRL OH LATER THIS EVENING...ESPECIALLY IN THE ABSENCE OF HEATING. ...MIDDLE TN/NCNTRL GULF COAST... BROAD WARM ADVECTION AND STRONG DAYTIME HEATING CONTRIBUTED TO AFTERNOON CONVECTION FROM PORTIONS OF AR...EWD ACROSS MIDDLE TN INTO CNTRL AL. AS DEEP LAYER FLOW GRADUALLY VEERS THIS EVENING...IT APPEARS CONVECTION WILL BECOME CONCENTRATED OVER NRN AL/SRN TN INTO NWRN PORTIONS OF GA. SUFFICIENT VERTICAL SHEAR EXISTS ACROSS THIS REGION FOR MAINTAINING UPDRAFT ORGANIZATION...THUS A FEW STORMS WILL CONTINUE TO PRODUCE HAIL AND LOCALLY DAMAGING WINDS FOR THE NEXT 2-4 HOURS. ...NORTH TX/SRN OK... STALLED FRONTAL ZONE WILL BEGIN TO LIFT NWD ACROSS TX THIS EVENING WITH WEAK WARM ADVECTION EXPECTED TO ENHANCE ASCENT ATOP BOUNDARY LAYER...ESPECIALLY TOWARD THE END OF THE PERIOD. FORECAST SOUNDINGS DISPLAY SUFFICIENT ELEVATED INSTABILITY FOR THUNDERSTORM DEVELOPMENT...THE MAIN IMPEDIMENT FOR ORGANIZED SEVERE THUNDERSTORMS AT THIS TIME APPEARS TO BE THE LACK OF A STRONG LLJ/FORCING. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 05:44:45 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 00:44:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010542 SWODY1 SPC AC 010540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN TX INTO SOUTH CENTRAL KS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM WEST TX INTO SRN NEB...WRN MO...AR...AND NRN LA... ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS FRIDAY... ...CNTRL/SRN PLAINS... UPPER RIDGE WILL BREAK DOWN OVER THE PLAINS EARLY IN THE PERIOD AS A TROUGH EJECTS ACROSS THE SWRN U.S./SRN ROCKIES INTO THE HIGH PLAINS OF WRN KS/TX PANHANDLE BY 00Z/02. LATEST WATER VAPOR IMAGERY DEPICTS A WELL DEFINED UPPER VORT JUST WEST OF SAN...CLEARLY DEFINED AND LIKELY STRONGER THAN MODELS ARE INDICATING. THIS FEATURE WILL PROVE INSTRUMENTAL IN WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT FROM WRN KS INTO THE TX PANHANDLE BY 21Z. LATE EVENING DIAGNOSTIC DATA AND TRENDS SUGGEST BOUNDARY LAYER RECOVERY IS WELL UNDER WAY ACROSS NORTH TX WITH WARM ADVECTION/MOISTENING CONTRIBUTING TO RECENT THUNDERSTORM DEVELOPMENT ACROSS THE TX SOUTH PLAINS...JUST SE OF LBB. IT APPEARS WARM FRONT WILL LIFT INTO OK LATER THIS MORNING AND SLOWLY LOSE ITS IDENTITY. EVEN SO...THUNDERSTORM CLUSTERS MAY BE NOTED WITH THIS RETREAT ACROSS SRN OK...THEN INTO PORTIONS OF AR/LA LATER IN THE MORNING AS BOUNDARY LAYER WARMS/DESTABILIZES. OF MORE CONCERN IS THE EXPECTED RAPID MOISTENING INTO THE TX PANHANDLE/WRN OK INTO WRN KS AHEAD OF UPPER SHORTWAVE. LATEST THINKING IS MODERATE INSTABILITY WILL DEVELOP AS FAR NW AS SWRN KS...WITH SBCAPES IN EXCESS OF 3000 J/KG FARTHER SOUTH INTO THE TX PANHANDLE/WRN OK WHERE MID 60S DEW POINTS WILL BE IN PLACE AHEAD OF THUNDERSTORM INITIATION. IT APPEARS CONVECTION WILL INITIATE PRIOR TO 21Z OVER THE WRN TX PANHANDLE...THEN SPREAD/DEVELOP EWD INTO VERY FAVORABLE ENVIRONMENT FOR SUPERCELLS. FORECAST SOUNDINGS STRONGLY FAVOR TORNADO DEVELOPMENT IF BOUNDARY LAYER MOISTURE DOES INDEED RETURN AS EXPECTED. VERY LARGE HAIL WILL ALSO ACCOMPANY THIS ACTIVITY AS IT SPREADS DOWNSTREAM. BY LATE EVENING AN UPWARD EVOLVING LINEAR MCS WITH EMBEDDED SUPERCELLS AND BOW ECHOES SHOULD SPREAD ACROSS THE REMAINDER OF CNTRL KS/OK TOWARD WRN MO BY THE END OF THE PERIOD. ...LOWER MS VALLEY... RETREATING WARM FRONT ACROSS THE ARKLATEX REGION WILL ENHANCE INSTABILITY/FOCUS FOR LATE MORNING INTO AFTERNOON THUNDERSTORM CLUSTERS ACROSS AR INTO WRN MS. WEAK WARM ADVECTION MAY AID INITIAL THUNDERSTORM DEVELOPMENT...HOWEVER DAYTIME HEATING SHOULD ALSO CONTRIBUTE TO STRONGER THUNDERSTORM ACTIVITY. LARGE HAIL AND DAMAGING DOWNBURSTS SHOULD BE THE PRIMARY FOCUS BEFORE CONVECTION WEAKENS AND LIFTS NEWD INTO THE TN VALLEY LATER IN THE EVENING. ...NERN U.S... A NARROW WEDGE OF MOISTENING/HEATING WILL OCCUR AHEAD OF COLD FRONT ACROSS NY INTO PORTIONS OF SRN NEW ENGLAND LATER THIS MORNING. FORECAST SOUNDINGS ACROSS THE HUDSON VALLEY INTO ERN PA SUGGEST 200-400 J/KG SFC-BASED INSTABILITY WILL DEVELOP PRIOR TO FRONTAL PASSAGE. IT APPEARS A FORCED LINE OF LOW TOPPED THUNDERSTORMS WILL EVOLVE ALONG THE WIND SHIFT THEN SURGE EWD ACROSS THE REMAINDER OF NEW ENGLAND DURING THE AFTERNOON. FORECAST SHEAR AND THE POSSIBILITY FOR WLY MOMENTUM TRANSFER ARE NOT THAT SIGNIFICANT GIVEN THE WEAK INSTABILITY ENVIRONMENT. FORECAST STORM MOTIONS SUGGEST LOCALLY STRONG/DAMAGING WIND GUSTS WITH MORE ORGANIZED CELLS...HOWEVER AT THIS TIME IT APPEARS COVERAGE OF SEVERE WIND GUSTS WILL NOT WARRANT A SLIGHT RISK. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 05:54:48 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 00:54:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010553 SWODY1 SPC AC 010551 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1151 PM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN TX INTO SOUTH CENTRAL KS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM WEST TX INTO SRN NEB...WRN MO...AR...AND NRN LA... CORRECTED FOR WRONG DAY ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS SATURDAY... ...CNTRL/SRN PLAINS... UPPER RIDGE WILL BREAK DOWN OVER THE PLAINS EARLY IN THE PERIOD AS A TROUGH EJECTS ACROSS THE SWRN U.S./SRN ROCKIES INTO THE HIGH PLAINS OF WRN KS/TX PANHANDLE BY 00Z/02. LATEST WATER VAPOR IMAGERY DEPICTS A WELL DEFINED UPPER VORT JUST WEST OF SAN...CLEARLY DEFINED AND LIKELY STRONGER THAN MODELS ARE INDICATING. THIS FEATURE WILL PROVE INSTRUMENTAL IN WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT FROM WRN KS INTO THE TX PANHANDLE BY 21Z. LATE EVENING DIAGNOSTIC DATA AND TRENDS SUGGEST BOUNDARY LAYER RECOVERY IS WELL UNDER WAY ACROSS NORTH TX WITH WARM ADVECTION/MOISTENING CONTRIBUTING TO RECENT THUNDERSTORM DEVELOPMENT ACROSS THE TX SOUTH PLAINS...JUST SE OF LBB. IT APPEARS WARM FRONT WILL LIFT INTO OK LATER THIS MORNING AND SLOWLY LOSE ITS IDENTITY. EVEN SO...THUNDERSTORM CLUSTERS MAY BE NOTED WITH THIS RETREAT ACROSS SRN OK...THEN INTO PORTIONS OF AR/LA LATER IN THE MORNING AS BOUNDARY LAYER WARMS/DESTABILIZES. OF MORE CONCERN IS THE EXPECTED RAPID MOISTENING INTO THE TX PANHANDLE/WRN OK INTO WRN KS AHEAD OF UPPER SHORTWAVE. LATEST THINKING IS MODERATE INSTABILITY WILL DEVELOP AS FAR NW AS SWRN KS...WITH SBCAPES IN EXCESS OF 3000 J/KG FARTHER SOUTH INTO THE TX PANHANDLE/WRN OK WHERE MID 60S DEW POINTS WILL BE IN PLACE AHEAD OF THUNDERSTORM INITIATION. IT APPEARS CONVECTION WILL INITIATE PRIOR TO 21Z OVER THE WRN TX PANHANDLE...THEN SPREAD/DEVELOP EWD INTO VERY FAVORABLE ENVIRONMENT FOR SUPERCELLS. FORECAST SOUNDINGS STRONGLY FAVOR TORNADO DEVELOPMENT IF BOUNDARY LAYER MOISTURE DOES INDEED RETURN AS EXPECTED. VERY LARGE HAIL WILL ALSO ACCOMPANY THIS ACTIVITY AS IT SPREADS DOWNSTREAM. BY LATE EVENING AN UPWARD EVOLVING LINEAR MCS WITH EMBEDDED SUPERCELLS AND BOW ECHOES SHOULD SPREAD ACROSS THE REMAINDER OF CNTRL KS/OK TOWARD WRN MO BY THE END OF THE PERIOD. ...LOWER MS VALLEY... RETREATING WARM FRONT ACROSS THE ARKLATEX REGION WILL ENHANCE INSTABILITY/FOCUS FOR LATE MORNING INTO AFTERNOON THUNDERSTORM CLUSTERS ACROSS AR INTO WRN MS. WEAK WARM ADVECTION MAY AID INITIAL THUNDERSTORM DEVELOPMENT...HOWEVER DAYTIME HEATING SHOULD ALSO CONTRIBUTE TO STRONGER THUNDERSTORM ACTIVITY. LARGE HAIL AND DAMAGING DOWNBURSTS SHOULD BE THE PRIMARY FOCUS BEFORE CONVECTION WEAKENS AND LIFTS NEWD INTO THE TN VALLEY LATER IN THE EVENING. ...NERN U.S... A NARROW WEDGE OF MOISTENING/HEATING WILL OCCUR AHEAD OF COLD FRONT ACROSS NY INTO PORTIONS OF SRN NEW ENGLAND LATER THIS MORNING. FORECAST SOUNDINGS ACROSS THE HUDSON VALLEY INTO ERN PA SUGGEST 200-400 J/KG SFC-BASED INSTABILITY WILL DEVELOP PRIOR TO FRONTAL PASSAGE. IT APPEARS A FORCED LINE OF LOW TOPPED THUNDERSTORMS WILL EVOLVE ALONG THE WIND SHIFT THEN SURGE EWD ACROSS THE REMAINDER OF NEW ENGLAND DURING THE AFTERNOON. FORECAST SHEAR AND THE POSSIBILITY FOR WLY MOMENTUM TRANSFER ARE NOT THAT SIGNIFICANT GIVEN THE WEAK INSTABILITY ENVIRONMENT. FORECAST STORM MOTIONS SUGGEST LOCALLY STRONG/DAMAGING WIND GUSTS WITH MORE ORGANIZED CELLS...HOWEVER AT THIS TIME IT APPEARS COVERAGE OF SEVERE WIND GUSTS WILL NOT WARRANT A SLIGHT RISK. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 12:44:13 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 07:44:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011241 SWODY1 SPC AC 011240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST SAT APR 01 2006 VALID 011300Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF WRN OK...SWRN KS...ERN TX PANHANDLE LATE THIS AFTERNOON AND EARLY TONIGHT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SRN/CENTRAL PLAINS... ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS LATER TODAY... ...SRN/CENTRAL PLAINS... DRY LINE SEVERE PATTERN...MORE TYPICAL LATER IN THE SPRING...WILL DEVELOP FROM WRN KS INTO PORTIONS OF WRN TX/OK TODAY AND TONIGHT. PRESSURE FALLS AHEAD OF LOW AMPLITUDE SHORTWAVE TROUGH...NOW LIFTING NEWD ACROSS THE SRN ROCKIES...WILL INCREASE SSELY LOW LEVEL FLOW INTO THE SRN/CENTRAL HIGH PLAINS THROUGH THE AFTERNOON. AS THIS OCCURS...BOUNDARY LAYER MOISTURE WILL QUICKLY INCREASE DUE TO BOTH DOWNWARD MIXING AND ADVECTION UNDER STRONG CAP EVIDENT AT FTW/OUN THIS MORNING...WITH AXIS OF 50+F SURFACE DEW POINTS EXPECTED INTO WRN KS AND MID/UPPER 60F DEW POINTS ALONG AND SOUTH OF I-40 BY LATE THIS AFTERNOON. MODELS ARE IN AGREEMENT IN MIXING DRY LINE/LEE TROUGH ALONG AN AXIS EXTENDING FROM NEAR THE KS/CO BORDER SWD INTO THE CENTRAL TX PANHANDLE BY 21Z...WHICH THEN PROGRESSES EWD INTO WRN OK/CENTRAL KS THIS EVENING IN WAKE OF DEEPENING LOW CENTER LIFTING INTO SERN NEB OVERNIGHT. HEATING AND MOISTENING WITHIN THE BOUNDARY LAYER WILL BE AUGMENTED BY INCREASING LARGE SCALE ASCENT AND SUPPORT RAPID SEVERE THUNDERSTORM DEVELOPMENT FROM SWRN KS INTO THE ERN TX PANHANDLE...MOST LIKELY AROUND 21-22Z. STORMS WILL QUICKLY BECOME SUPERCELLS WITH EFFECTIVE BULK-SHEAR NEAR 50 KT...0-2 KM SRH FROM 150-200 M2/S2 AND MLCAPE APPROACHING 2000 J/KG. AS CAP BREAKS AND STRONGEST ASCENT OVERSPREADS THE REGION...STORMS WILL BECOME INCREASINGLY WIDESPREAD WITH POTENTIAL FOR VERY LARGE HAIL AND TORNADOES. CAPPING WILL LIMIT SWD DEVELOPMENT ALONG DRY LINE INTO MORE OF WRN TX. HOWEVER...SHEAR WILL REMAIN SUPPORTIVE OF SUPERCELLS SHOULD AN ISOLATED STORM OR TWO DEVELOP LATER TODAY. TORNADO THREAT WILL LIKELY INCREASE AROUND 00Z AS SUPERCELLS MATURE...LOW LEVEL RH INCREASES AND LLJ BEGINS TO DECOUPLE/INTENSIFY. FORECAST SOUNDINGS...ESPECIALLY INTO RICHER BOUNDARY LAYER MOISTURE OVER SWRN OK/NWRN TX...WILL BECOME FAVORABLE FOR SIGNIFICANT TORNADOES LATE TODAY AND EARLY THIS EVENING. ACTIVITY WILL LIKELY ORGANIZE INTO AN MCS AS IT LIFTS ENEWD ACROSS NRN OK/KS THIS EVENING...WITH MORE DISCRETE DEVELOPMENT DIMINISHING DURING THE MID EVENING SOUTH OF I-40 AS CAPPING INCREASES AND LARGE SCALE ASCENT LIFTS INTO THE CENTRAL PLAINS. SEVERE THREAT...MAINLY IN THE FORM OF LARGE HAIL AND ISOLATED DAMAGING WINDS...SHOULD SPREAD INTO PORTIONS OF SRN NEB AND ERN KS/WRN MO LATER TONIGHT. ...SERN OK INTO THE LOWER MS RIVER VALLEY... MODELS INDICATE CAP WILL REMAIN WEAK ALONG STALLED SURFACE FRONT NOW EXTENDING ROUGHLY E-W ACROSS THIS REGION. DEEP LAYER SHEAR IS FORECAST TO REMAIN MODEST...20-30 KT OF 0-6 KM SHEAR...WITH WEAK LAPSE RATES EVIDENT ON MORNING SOUNDINGS. THUS...DESPITE MODERATE INSTABILITY...SEVERE THREAT WILL LIKELY REMAIN LIMITED TODAY THOUGH AN ISOLATED LARGE HAIL/DAMAGING WIND SHOULD ACCOMPANY STRONGER CELLS. ...NEW ENGLAND ACROSS THE CHESAPEAKE REGION... BROAD AREA OF 50+ SURFACE DEW POINTS AND RATHER WARM SURFACE TEMPERATURES WILL SUPPORT MARGINAL INSTABILITY AHEAD OF SURFACE COLD FRONT MOVING ACROSS WRN NY/PA AT 12Z. THIS FRONT WILL CONTINUE EWD OFF THE COAST BY LATER TODAY. CONVECTION HAS ALREADY INCREASED NEAR THE FRONT INTO CENTRAL NY EARLY THIS MORNING /REFERENCE SWOMCD 387 FOR FURTHER DETAILS/. DIURNAL HEATING AND 30-40 KT WSWLY FLOW JUST OFF THE SURFACE SHOULD SUPPORT STRONG TO ISOLATED SEVERE WIND GUSTS WITH THUNDERSTORMS DEVELOPING ALONG AND AHEAD OF THE FRONT FROM PORTIONS OF NEW ENGLAND ACROSS MUCH OF THE MID ATLANTIC/CHESAPEAKE. ..EVANS/CROSBIE.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 16:37:51 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 11:37:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011634 SWODY1 SPC AC 011632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SAT APR 01 2006 VALID 011630Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTERNOON INTO EARLY TONIGHT ACROSS WRN OK...THE ERN TX PANHANDLE...AND SW KS.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NW TX NWD TO SE NEB THROUGH TONIGHT...AND SEWD ACROSS ERN OK INTO SW AR THIS AFTERNOON.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS THE TIDEWATER AREA.... ...SRN PLAINS THIS AFTERNOON INTO TONIGHT... BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S WILL CONTINUE TO SPREAD NWD ACROSS OK/KS/NW TX...IN RESPONSE TO CYCLOGENESIS ACROSS ERN CO/WRN KS IN ADVANCE OF A LEAD SHORTWAVE TROUGH PROGRESSING EWD/ENEWD OVER WRN NM/CO THIS MORNING. S OF THE DEVELOPING SURFACE LOW...A DRYLINE WILL BECOME BETTER DEFINED BY LATE AFTERNOON ACROSS THE CENTRAL TX PANHANDLE. 12Z UPPER AIR ANALYSES AND 00-12Z CHANGES IN OBSERVED SOUNDINGS SUGGEST THAT CONVECTIVE INHIBITION WILL BE MINIMIZED E OF THE DRYLINE WITH AFTERNOON TEMPERATURES IN THE UPPER 70S TO LOWER 80S...AND THAT STORM INITIATION IS LIKELY BY ABOUT 22Z ACROSS THE CENTRAL TX PANHANDLE. STORMS SHOULD THEN MOVE EWD/NEWD INTO SW KS AND WRN OK DURING THE EVENING AND EARLY OVERNIGHT HOURS...AND CONTINUE THROUGH MOST OF THE NIGHT ACROSS KS INTO NRN OK. SUBSTANTIAL LOW-LEVEL MOISTENING TODAY BENEATH 8 C/KM MID LEVEL LAPSE RATES WILL RESULT IN STRONG DESTABILIZATION THROUGH THE AFTERNOON E OF THE DEVELOPING DRYLINE AND S OF THE WARM FRONT...WHERE MLCAPE VALUES OF 2000-3500 J/KG APPEAR LIKELY. THOUGH VERTICAL SHEAR WILL BE SOMEWHAT LIMITED THROUGH MID AFTERNOON...INCREASING LOW-MID LEVEL FLOW FROM 21-03Z WILL RESULT IN INCREASINGLY FAVORABLE HODOGRAPH STRUCTURES FOR SUPERCELLS WITH TORNADOES AND VERY LARGE HAIL AS CONVECTION MOVES INTO W/NW OK THIS EVENING. THE THREAT FOR DAMAGING WINDS WILL GRADUALLY INCREASE DURING THE EVENING AS CONVECTION MERGES AND GROWS UPSCALE INTO MORE OF A LINE/MCS ACROSS OK/KS BY EARLY TONIGHT. ...SE VA AREA THIS AFTERNOON... BOUNDARY LAYER DEWPOINTS REMAIN IN THE UPPER 50S TO LOWER 60S...WHILE STRONG SURFACE HEATING WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S THIS AFTERNOON IN ADVANCE OF A WEAK PRE-FRONTAL TROUGH AND COLD FRONT. THE NET RESULT WILL BE SOUNDING PROFILES WITH VERY STEEP LOW-LEVEL LAPSE RATES AND MLCAPE VALUES AOA 1000 J/KG. ADDITIONALLY...40 KT LOW-MID LEVEL FLOW AND MODEST DEEP LAYER SHEAR MAY SUPPORT A FEW SUPERCELLS AND/OR LINE SEGMENTS CAPABLE OF PRODUCING DAMAGING WINDS AND LARGE HAIL DURING THE AFTERNOON. ..THOMPSON/JEWELL.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 20:01:14 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 15:01:14 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011958 SWODY1 SPC AC 011956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST SAT APR 01 2006 VALID 012000Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PARTS OF SWRN KS / THE ERN OK AND TX PNHDLS / WRN OK AND NWRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM THE MID MO VALLEY SWD INTO THE SRN PLAINS AND ARKLATEX... --CONCENTRATED SEVERE WEATHER EVENT IS STILL ANTICIPATED THIS AFTERNOON AND TONIGHT OVER PORTIONS OF THE CNTRL AND SRN PLAINS-- ...CNTRL / SRN PLAINS... 19Z MESOANALYSIS INDICATED LEE CYCLONE DEVELOPMENT OCCURRING OVER ERN CO WITH ASSOCIATED WARM FRONT EXTENDING SEWD THROUGH SERN CO/SWRN KS AND INTO NERN OK...WHILE DRY LINE WAS BECOMING BETTER DEFINED FROM E OF DHT TO E OF MAF. RAPID AIR MASS DESTABILIZATION IS IN PROGRESS E OF THE DRY LINE AND S OF THE WARM FRONT FROM NWRN TX ACROSS THE ERN TX/OK PNHDLS AND WRN OK INTO WRN KS. MODIFICATION OF 18Z SOUNDINGS FROM MAF AND AMA FOR MORE MOIST BOUNDARY-LAYER TO THE E YIELDS MLCAPES OF 2000-3000 J/KG AND A WEAKENING CAP. RAPID TSTM DEVELOPMENT IS ANTICIPATED BY 21-22Z ALONG DRY LINE FROM THE TX PNHDL NWD TO ALONG ITS INTERSECTION WITH WARM FRONT AS WEAK SHORTWAVE TROUGH/SPEED MAXIMUM OVER CNTRL NM APPROACHES WRN EDGE OF INSTABILITY AXIS. WHILE VERTICAL SHEAR PROFILES ARE CURRENTLY ONLY MARGINALLY FAVORABLE FOR ORGANIZED SEVERE STORMS...STRENGTHENING LOW-LEVEL SHEAR ALONG WITH INTENSIFICATION OF MID AND HIGH-LEVEL WIND FIELDS WILL RESULT IN VERTICAL SHEAR PROFILES QUITE FAVORABLE FOR INTENSE SUPERCELLS CAPABLE OF DESTRUCTIVE HAIL AND TORNADOES. IT APPEARS THE GREATEST POTENTIAL FOR A FEW STRONG TORNADOES WILL EXIST PRIMARILY BETWEEN 23-03Z AS BOUNDARY-LAYER RH INCREASES AND LOW-LEVEL SHEAR FURTHER INTENSIFIES /I.E. 0-1 KM SRH OF 200-300 M2/S2/. CLUSTERS OF SEVERE TSTMS SHOULD MOVE DEVELOP NEWD ACROSS KS/NEB TONIGHT AS LLJ BROADENS AND INTENSIFIES AHEAD OF MID-LEVEL TROUGH MOVING OUT OF THE ROCKIES. WHILE LARGE HAIL AND DAMAGING WINDS WILL REMAIN THE PRIMARY SEVERE WEATHER THREATS...ISOLATED TORNADOES WILL BE POSSIBLE WITH ANY STORMS THAT CAN REMAIN DISCRETE AND SURFACE-BASED. ...NERN TX / ERN OK / AR / NRN LA... ERN EXTENSION OF WARM FRONT EXTENDS FROM N OF TUL TO NEAR HOT AND THEN EWD ACROSS NRN MS. AIR MASS ALONG AND S OF THIS BOUNDARY IS MOIST WITH DEWPOINTS IN THE 60S...AND WHEN COUPLED WITH DAYTIME HEATING...ENVIRONMENT HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-2000 J/KG. AFTERNOON WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH SHIFTING EWD THROUGH THE ARKLATEX WHICH SHOULD SUPPORT DIURNAL TSTM DEVELOPMENT FROM VICINITY OF WARM FRONT SWD INTO FREE WARM SECTOR. WHILE MID AND HIGH-LEVEL WIND FIELDS ARE NOT PARTICULARLY STRONG...AREA VWPS AND PROFILERS DO SHOW CONSIDERABLE VEERING WITH HEIGHT. POTENTIAL WILL EXIST FOR ORGANIZED...SEVERE TSTMS THIS AFTERNOON INTO EVENING WITH THE THREAT OF LARGE HAIL...DAMAGING WINDS AND PERHAPS A TORNADO OR TWO...ESPECIALLY NEAR WARM FRONT. PERSISTENT TSTM CLUSTER JUST N OF WARM FRONT OVER FAR NERN OK INTO SWRN MO MAY ALSO INTENSIFY THIS AFTERNOON OWING TO INFLUX OF UNSTABLE AIR MASS FROM THE SW...WITH SEVERE WEATHER POTENTIAL DEVELOPING ACROSS SWRN MO. ...SERN VA / NERN NC... STRONG DAYTIME HEATING AND RESULTANT STEEPENING OF LOW-LEVEL LAPSE RATES HAVE CONTRIBUTED TO AIR MASS DESTABILIZATION AHEAD OF COLD FRONT AND PRE-FRONTAL TROUGH ACROSS THE TIDEWATER REGION WITH MLCAPES OF AROUND 1000 J/KG. WATER VAPOR IMAGERY SHOWS A COMPACT VORTICITY MAXIMUM TRANSLATING EWD THROUGH CHESAPEAKE BAY INTO DE WHICH IS LIKELY CONTRIBUTING TO SOME INTENSIFICATION OF ONGOING STORMS. SOME POTENTIAL EXISTS FOR THE SWWD DEVELOPMENT OF TSTMS ACROSS SERN VA INTO NERN NC LATE THIS AFTERNOON INTO EARLY EVENING AS SURFACE FRONT MOVES THROUGH AREA. THOUGH ISOLATED LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH ANY ADDITIONAL STORMS THAT DEVELOP...IT APPEARS THAT THIS THREAT IS TOO LIMITED TO WARRANT A CATEGORICAL OUTLOOK. ..MEAD.. 04/01/2006  From SWODY1 at goshenarc.org Sun Apr 2 01:05:08 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 20:05:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020102 SWODY1 SPC AC 020101 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0701 PM CST SAT APR 01 2006 VALID 020100Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SOUTHERN KANSAS...WESTERN OKLAHOMA, AND WESTERN NORTH TEXAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL PLAINS INTO OK/TX AND WRN PARTS OF MO/AR... ...CENTRAL AND SRN PLAINS... N-S CLUSTER OF SEVERE STORMS/SUPERCELLS IS NOW SHIFTING ACROSS CENTRAL KS/WRN OK/WRN N TX...INTO INTO INCREASINGLY-MOIST/ MODERATELY-UNSTABLE AIRMASS. SLY LOW-LEVEL JET HAS BEGUN TO INCREASE...AND WILL CONTINUE TO DO SO THIS EVENING AS UPPER TROUGH CONTINUES SHIFTING EWD INTO THE REGION. THIS COMBINED WITH 50 KT WSWLY MID-LEVEL JET WILL YIELD INCREASINGLY-FAVORABLE DEEP-LAYER SHEAR FOR SEVERE/SUPERCELL STORMS. THEREFORE...EXPECT STORMS TO REMAIN CAPABLE OF PRODUCING VERY LARGE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONALLY...WITH SURFACE LOW FORECAST TO LINGER OVER WRN KS THROUGH THE EVENING...RESULTING SSWLY SURFACE WINDS VEERING/INCREASING TO SWLY AT 40-PLUS KT NEAR 3 KM WILL YIELD LOW-LEVEL SHEAR SUPPORTIVE OF A COUPLE OF STRONG TORNADOES. ...AR/WRN MO... THUNDERSTORMS CONTINUE INVOF WARM FRONT/WITHIN ZONE OF STRONG LOW-LEVEL WARM ADVECTION. AIRMASS REMAINS UNSTABLE INVOF FRONT /500 TO 1000 J/KG MEAN-LAYER CAPE/...BUT SHEAR REMAINS SOMEWHAT LIMITED ATTM. HOWEVER...AS UPPER TROUGH AND ASSOCIATED MID-LEVEL JET STREAK SHIFT EWD OVERNIGHT...SHEAR WILL INCREASE ACROSS AR AND WRN MO. THEREFORE...EXPECT THREAT FOR HAIL AND LOCALLY DAMAGING WINDS TO PERSIST THROUGH THE NIGHT. ..GOSS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 06:03:48 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 01:03:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020601 SWODY1 SPC AC 020559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 PM CST SAT APR 01 2006 VALID 021200Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS EASTERN MISSOURI...SOUTHEAST IOWA...MUCH OF ILLINOIS...SOUTHWEST INDIANA...AND WESTERN KENTUCKY.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN FRINGES OF THE PLAINS TO THE APPALACHIANS... ...SYNOPSIS... MID-LEVEL SHORT-WAVE TROUGH IS FORECAST TO DEEPEN WHILE SHIFTING EWD FROM THE PLAINS ACROSS THE MS VALLEY AND INTO THE UPPER GREAT LAKES/OH AND TN VALLEYS THROUGH THE END OF THE PERIOD. A 70-PLUS KT H5 JET STREAK IS FORECAST TO ACCOMPANY THIS TROUGH...WITH THE CORE OF THIS JET EXPECTED FROM THE CENTRAL PLAINS EWD ACROSS THE OZARKS/MID MS VALLEY REGION AND INTO THE TN AND OH VALLEYS. AT THE SURFACE...LOW INITIALLY FORECAST OVER ERN NEB SHOULD DEEPEN AND MOVE ENEWD WITH TIME...EVENTUALLY REACHING LOWER MI AS A 990 MB CYCLONE. WARM FRONT INITIALLY FORECAST TO EXTEND SEWD ACROSS MO INTO THE SERN U.S. SHOULD LIFT NEWD ACROSS THE TN AND OH VALLEYS WITH TIME...ALLOWING MOIST/UNSTABLE WARM SECTOR TO SPREAD ACROSS THE MID MS VALLEY REGION AHEAD OF COLD FRONT. THIS COLD FRONT SHOULD CROSS MO DURING THROUGH THE AFTERNOON...AND THEN CONTINUE EWD ACROSS THE OH VALLEY REGION THROUGH THE OVERNIGHT HOURS. TRAILING PORTION OF THE FRONT SHOULD SAG MORE SLOWLY SWD...LINGERING ACROSS AR AND TX THROUGH THE END OF THE PERIOD. ...MID MS/OH/TN VALLEYS... POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE APPEARS TO BE SETTING UP THIS PERIOD...CENTERED ON THE MID MS AND LOWER OH VALLEY REGION. THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE MIDDLE AND LOWER MO VALLEY AHEAD OF APPROACHING UPPER TROUGH. THIS CONVECTION SHOULD SHIFT EWD/NEWD INTO THE UPPER GREAT LAKES REGION THROUGH THE DAY. THOUGH THIS INITIAL CONVECTION COMPLICATES THE FORECAST DUE TO ITS POTENTIAL EFFECTS ON AFTERNOON DESTABILIZATION...IT APPEARS ATTM THAT MOST OF THE CONVECTION SHOULD VACATE THE MID MS VALLEY REGION BY AFTERNOON...ALLOWING DAYTIME HEATING TO COMMENCE. PRESUMING THIS OCCURS...1500 TO 2500 J/KG MEAN-LAYER CAPE SHOULD DEVELOP ACROSS THE WARM SECTOR...AIDED BY NWD ADVECTION OF LOW TO MID 60S DEWPOINTS BENEATH STEEPENING MID-LEVEL LAPSE RATES. STORMS SHOULD REDEVELOP BY MID AFTERNOON -- LIKELY FROM SERN IA SWD ACROSS THE ERN HALF OF MO AHEAD OF ADVANCING COLD FRONT. DEEP-LAYER WIND FIELD SHOULD BE QUITE STRONG ACROSS THIS REGION...AS POTENT MID-LEVEL JET SHIFTS EWD INTO THE REGION. ALONG WITH FAVORABLE DEEP-LAYER SHEAR FOR SUPERCELLS...LOW-LEVEL SHEAR WILL ALSO BE STRONG -- PARTICULARLY FROM ERN IA SWD ACROSS ERN MO AND IL NEAR AND SE OF SURFACE LOW. DEGREE OF LOW-LEVEL SHEAR ALONG WITH MOIST/MODERATELY-UNSTABLE AIRMASS SUGGESTS THAT SEVERAL TORNADOES WILL LIKELY OCCUR...A FEW OF WHICH COULD BE STRONG AND LONG-LIVED. ADDITIONALLY...LARGE HAIL AND LOCALLY DAMAGING WINDS ARE ALSO EXPECTED. WITH TIME...STORMS SHOULD BECOME MORE LINEAR -- PARTICULARLY ACROSS THE OH VALLEY WHERE FLOW WILL BECOME MORE VEERED/UNIDIRECTIONAL WITH HEIGHT THROUGH THE EVENING. GIVEN STRENGTH OF THE WIND FIELD...MORE ORGANIZED/WIDESPREAD DAMAGING WIND EVENT MAY EVOLVE/MOVE EWD ACROSS THIS REGION. STORMS SHOULD CONTINUE THROUGH THE END OF THE PERIOD...WITH SEVERE THREAT EXTENDING AS FAR E AS THE CENTRAL APPALACHIANS BY 03/12Z. ..GOSS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 12:33:24 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 08:33:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021231 SWODY1 SPC AC 021229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT SUN APR 02 2006 VALID 021300Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER CENTRAL/ERN MO...FAR SERN IA...WRN/SRN IL...FAR WRN KY THIS AFTERNOON INTO THE EVENING... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM NERN TX/LOWER MS RIVER VALLEY INTO THE SRN GREAT LAKES... ...MO ACROSS MID MS/OH/TN RIVER VALLEYS... COMPLEX FORECAST THIS MORNING AS LINEAR MCS CONTINUES TO LIFT NEWD ACROSS THE MID MS RIVER VALLEY...WHICH WILL LIKELY HINDER HEATING/NWD RETURN OF WARM FRONT INTO THE EARLY AFTERNOON. HOWEVER...SURFACE WINDS CONTINUE TO BACK TO SLY BEHIND THIS ACTIVITY WITH STRONG PRESSURE FALLS DEVELOPING TOWARDS SERN IA EARLY THIS MORNING. THIS SHOULD ALLOW BOUNDARY LAYER MOISTURE TO RECOVER TODAY...WITH LOWER TO MID 60F SURFACE DEW POINTS EXPECTED TO LIFT ACROSS MUCH OF MO/LOWER OH RIVER VALLEY BY THE MID AFTERNOON. MID LEVEL LAPSE RATES WILL ALSO BE ABLE TO RELOAD RELATIVELY QUICKLY UNDER VERY STRONG WLY FLOW ALOFT. THOUGH THERE REMAIN SOME QUESTIONS ABOUT AIR MASS QUALITY DUE TO MORNING STORMS...ESPECIALLY REGARDING HIGHER SEVERE PROBABILITIES...OVERNIGHT MODELS CONTINUE TO INDICATE FAVORABLE CONDITIONS FOR SEVERE THUNDERSTORMS/SUPERCELLS BY 21Z AT LEAST INTO CENTRAL MO. AT THIS TIME...EXPECT AXIS OF MODERATE INSTABILITY WITH MLCAPE FROM 1000-2000 J/KG TO NOSE NEAR THE IA/MO BORDER DURING THE MID TO LATE AFTERNOON. AS A RESULT...DEEP ASCENT AND CONVERGENCE ALONG PRIMARY SURFACE TROUGH SHOULD INCREASE SEVERE THUNDERSTORMS FROM WEST TO EAST INTO WRN AND CENTRAL MO AND POSSIBLY SRN IA BETWEEN 18Z-21Z. GIVEN EXPECTED MLCAPE...FORECAST SOUNDINGS CONTINUE TO INDICATE A VERY FAVORABLE SUPERCELL ENVIRONMENT WITH BRN SHEAR AROUND 60 M2/S2 AND SFC-1 KM SRH IN EXCESS OF 150 M2/S2. THUS...A FEW LONGER-LIVED SUPERCELLS AND BOW ECHOES WILL EVOLVE THROUGH THE LATE AFTERNOON. HAIL MAY BECOME QUITE LARGE WITH THIS ACTIVITY...WITH LOCAL HAIL MODEL INDICATING 2+ INCH HAIL FROM MANY OF THE FORECAST SOUNDINGS. SHOULD HEATING/DESTABILIZATION OVERCOME CAP ALONG WARM FRONT...ISOLATED SUPERCELLS MAY ALSO DEVELOP AHEAD OF THIS ACTIVITY ACROSS PORTIONS OF SRN/CENTRAL IL AND WRN IND. TORNADOES WILL ALSO REMAIN POSSIBLE AND WIND DAMAGE THREAT MAY BECOME ENHANCED AS STORMS SHIFT QUICKLY EWD AT 40-50 KT AND CONSOLIDATE INTO SMALL BOW ECHOES/LINES INTO THE EARLY EVENING. DEPENDING ON WHERE WARM FRONT SETS-UP...GREATER SEVERE THREAT WILL SPREAD INTO SRN/CENTRAL IL INTO THE EARLY EVENING. ACTIVITY SHOULD EVOLVE INTO ONE OR MORE MCSS AND SPREAD EWD ACROSS THE OH/TN RIVER VALLEYS AND THE SRN GREAT LAKES AFTER DARK. LARGE HAIL AND DAMAGING WINDS WILL REMAIN POSSIBLE...WITH AN ISOLATED TORNADO POSSIBLE GIVEN VERY STRONG SHEAR SHOULD STORMS REMAIN ROOTED INTO THE BOUNDARY LAYER. ...MID SOUTH SWWD INTO NERN TX... REGION WILL REMAIN REMOVED FROM STRONGEST LARGE SCALE ASCENT WHICH IS EXPECTED TO SUPPORT MORE WIDESPREAD SEVERE THREAT ALONG AND NORTH OF THE LOWER OH RIVER VALLEY TODAY. HOWEVER...SURFACE CONVERGENCE ALONG SURFACE TROUGH WILL SHIFT INTO WRN AR AND NRN TX BY 21Z...AND SPREAD ESEWD THROUGH THE EARLY EVENING. IN ADDITION...STRONG WLY H85 WINDS WILL MAINTAIN LOW LEVEL WAA ATOP DESTABILIZING WARM SECTOR AND MAY DEVELOP STORMS WELL AHEAD OF THE FRONT TODAY. WARM...EARLY-APRIL TEMPERATURES IN THE UPPER 70S/LOWER 80S WILL WEAKEN CAP AND SUPPORT A LARGE AREA OF MODERATE TO STRONG INSTABILITY GIVEN MID 60F SURFACE DEW POINTS ALREADY IN PLACE. SHEAR WILL ALSO REMAIN QUITE STRONG ACROSS THE REGION WITH EFFECTIVE SHEAR NEAR 60 KT AND SFC-1 KM SRH IN EXCESS OF 200 M2/S2. THIS WOULD SUPPORT SUPERCELLS...AND TORNADOES ACROSS THE MID SOUTH...SHOULD CAP BREAK AND VIGOROUS STORMS DEVELOP. ..EVANS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 16:38:37 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 12:38:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021635 SWODY1 SPC AC 021634 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CDT SUN APR 02 2006 VALID 021630Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS CENTRAL/ERN MO...SRN/WRN IL...EXTREME SERN IA...EXTREME NERN AR...EXTREME NWRN TN...WRN KY.... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM E TX TO WRN NC TO OH/SRN LOWER MI TO SERN NEB.... ...SYNOPSIS... PROGRESSIVE SHORTWAVE PATTERN ALOFT WILL FEATURE TWO-WAVE SYSTEM NOW CAUSING HEIGHT FALLS ACROSS MID/UPPER MS VALLEY REGION. INITIAL TROUGH OVER CENTRAL KS AND OK IS EXPECTED TO ACCELERATE EWD THEN NEWD ACROSS MO/IL/IA THROUGH 3/00Z...THEN WEAKEN THEREAFTER ACROSS PORTIONS INDIANA/LM/LOWER MI. MEANWHILE UPSTREAM SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN NEB/NERN CO/SERN WY -- WILL DIG SEWD ACROSS KS. EXPECT THIS FEATURE TO BECOME DOMINANT PERTURBATION AS IT PIVOTS EWD OVER MID MS VALLEY OVERNIGHT...REACHING FROM SRN LOWER MI TO WRN TN BY END OF PERIOD. AT SFC..CYCLONE OVER SERN NEB SHOULD MOVE ENEWD ACROSS ERN IA..DEEPENING/OCCLUDING TONIGHT AS IT APCHS/CROSSES SRN LM. ASSOCIATED COLD FRONT WILL MOVE SWD/SEWD ACROSS MUCH OF MO...OK AND SRN HIGH PLAINS...CATCHING UP WITH DRYLINE INITIALLY ANALYZED FROM SERN KS INTO SWRN OK. WARM FRONT -- ANALYZED AT 15Z FROM SERN NEB EWD ACROSS NERN MO...THEN SEWD OVER EXTREME SRN IL AND EXTREME WRN KY -- IS FCST TO LIFT NEWD ACROSS REMAINDER MO...MOST OF IL/KY AND PORTIONS SRN INDIANA THROUGH 3/00Z. ILL-DEFINED OUTFLOW BOUNDARY IS EVIDENT FROM E-CENTRAL AND CENTRAL AR NWWD ACROSS SWRN MO AND SWRN KS...AND SHOULD WEAKEN WITH TIME. ...E-CENTRAL PLAINS TO SRN GREAT LAKES AND OH VALLEY... SOME SEVERE POTENTIAL EXISTS AS INITIALLY ELEVATED TSTMS OVER N-CENTRAL/NERN KS AND SERN NEB MOVE EWD INTO DESTABILIZING LOW LEVEL ENVIRONMENT. OPTIMALLY STEEP MIDLEVEL LAPSE RATES ARE EVIDENT ATTM OVER PORTIONS NERN KS/SERN NEB...IN ZONE OF STRONGEST MIDLEVEL DPVA...AHEAD OF COLD-CORE LOW. REF SPC MESOSCALE DISCUSSION 400 FOR NEAR-TERM FCST DETAILS. THIS ACTIVITY AND/OR ADDITIONAL DEVELOPMENT OVER MO VALLEY REGION SHOULD MOVE EWD ACROSS MO INTO IL...AMIDST INCREASINGLY FAVORABLE DEEP-LAYER INSTABILITY. CONVECTIVELY STABILIZED BOUNDARY LAYER AIR MASS IS EVIDENT BETWEEN DIFFUSE OUTFLOW BOUNDARY AND WARM FRONT...WHICH WILL TEMPORARILY SUPPRESS SFC-BASED SEVERE POTENTIAL. EXPECT MOIST ADVECTION TO OFFSET VERTICAL MIXING WITHIN BOUNDARY LAYER AS MOISTURE RECOVERS OVER THIS REGION THROUGH MID-AFTERNOON. THIS SHOULD RESULT IN LOW-MID 60S F SFC DEW POINTS SPREADING NEWD FROM NERN OK/SERN KS/NRN AR REGION...ACROSS MORE OF MO THROUGH MID-LATE AFTERNOON. AS THIS OCCURS...SFC AIR MASS WILL DESTABILIZE CONSIDERABLY IN TUNE WITH STEEPENING MIDLEVEL LAPSE RATES. SHEAR PROFILES BY MID/LATE AFTERNOON AND EARLY EVENING WILL SUPPORT BOTH SUPERCELL AND BOW ECHO STRUCTURES...AND MIXED CONVECTIVE MODE IS EXPECTED. STRONG PRIMARY ARC OF ASCENT -- EXPECTED TO MOVE EWD ACROSS MO/SRN IA/IL -- SHOULD LEAD TO SOME LINEAR SEGMENTS WITH TIME. HOWEVER...DISCRETE SUPERCELLS ALSO ARE POSSIBLE BOTH EARLY IN EVOLUTION OF MAIN BAND AND FARTHER E IN WARM SECTOR. DAMAGING HAIL/GUSTS AND TORNADOES ALL ARE POSSIBLE...WITH SIGNIFICANT-TORNADO PROBABILITIES GREATEST INVOF WARM FRONT WHERE LOW LEVEL HODOGRAPHS AND DEEP-LAYER BULK SHEAR SHOULD BE MAXIMIZED. ACTIVITY SHOULD CONSOLIDATE INTO ONE OR MORE QUASI-LINEAR MCS OVERNIGHT...MOVING ENEWD ACROSS OH VALLEY AND SRN GREAT LAKES REGIONS. MAIN THREAT SHOULD BE DAMAGING WIND AND OCCASIONAL HAIL...THOUGH VERTICAL SHEAR PROFILES STILL WILL BE FAVORABLE FOR A FEW TORNADOES. ...ARKLATEX REGION...E TX...LOWER MS VALLEY... REF WW 129 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST SITUATION OVER PORTIONS CENTRAL/E TX. LATER THIS AFTERNOON...DECREASING CONVERGENCE IS EXPECTED WITH SWD EXTENT ACROSS OZARKS INTO ARKLATEX REGION AND NRN MS...AND WITH TIME OVER SAME REGION. THIS IS RELATED TO WEAKENING SFC WINDS AND SWLY FLOW IN MOIST LAYER. HOWEVER...WEAK CAPPING HAS ALLOWED DEVELOPMENT OVER PORTIONS CENTRAL TX...WITH MORE ACTIVITY POSSIBLY ENEWD TOWARD SRN AR/NRN LA AND EVENTUALLY NRN MS. SEVERE POTENTIAL FROM ANY ACTIVITY THAT DEVELOPS STILL WARRANTS CATEGORICAL SLGT RISK BECAUSE OF FAVORABLE DEEP-LAYER SHEAR AND BOUNDARY LAYER THETAE THAT WILL BE AVAILABLE. ..EDWARDS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 19:58:40 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 15:58:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021956 SWODY1 SPC AC 021955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SUN APR 02 2006 VALID 022000Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER ERN MO / FAR SERN IA / PORTIONS OF CNTRL AND SRN IL / WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM THE SRN GREAT LAKES AND OH VALLEY SWD INTO ERN TX AND THE TN VALLEY... ...IA/MO EWD INTO THE SRN GREAT LAKES AND OH VALLEY... LATEST MESOANALYSIS INDICATES SURFACE LOW OVER SWRN IA /SW OF DSM/ WHICH WILL CONTINUE TO DEVELOP NEWD...EVENTUALLY REACHING SRN LOWER MI MONDAY MORNING. ASSOCIATED WARM FRONT /NOW ANALYZED FROM THE LOW EWD ACROSS SRN IL/SWRN IND INTO CNTRL KY WILL CONCURRENTLY LIFT NEWD WHILE TRAILING COLD FRONT PUSHES EWD THROUGH MO INTO THE OH VALLEY. DIABATIC HEATING COUPLED WITH INFLUX OF LOW-LEVEL MOISTURE FROM THE SRN LOW PLAINS HAS CONTRIBUTED TO AIR MASS DESTABILIZATION S OF WARM FRONT AND E OF PACIFIC COLD FRONT WITH 18Z SGF SOUNDING INDICATING MLCAPES OF AROUND 2000 J/KG. SATELLITE AND RADAR DATA INDICATE SURFACE-BASED STORMS DEVELOPING FROM CDJ SWD TO SGF OWING INCREASED LARGE-SCALE FORCING ASSOCIATED WITH SHORTWAVE TROUGH OVER ERN NEB/KS ERODING REMAINING PORTION OF CAP ALONG WRN EDGE OF INSTABILITY AXIS. REGIONAL VADS/VWPS ACROSS WARM SECTOR INDICATE 40-50 KTS OF DEEP-LAYER SHEAR...SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE...DESTRUCTIVE HAIL...DAMAGING WINDS AND A FEW TORNADOES. IT APPEARS THE BEST POTENTIAL FOR A STRONG TORNADO OR TWO WILL EXIST WITHIN ZONE OF BACKED SURFACE WINDS AHEAD OF SURFACE LOW AND NEAR WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE MAXIMIZED. EXPECT THAT A GRADUAL UPSCALE GROWTH INTO LINE SEGMENTS OR QUASI-LINEAR MCS/S TO DEVELOP TONIGHT WITH THREAT OF PRIMARILY DAMAGING WINDS AND LARGE HAIL SPREAD EWD INTO THE OH VALLEY. ...AR/E TX EWD INTO THE TN AND LOWER MS VALLEYS... STRONG DAYTIME HEATING COUPLED WITH DEWPOINTS IN THE 70S AND STEEP LAPSE RATES HAVE CONTRIBUTED TO A MODERATELY UNSTABLE AIR MASS THIS AFTERNOON WITH MLCAPES OF 2000-2500 J/KG AHEAD OF PACIFIC COLD FRONT OR ADVECTIVE DRY LINE. ALOFT...WATER VAPOR IMAGERY INDICATES A CYCLONICALLY CURVED BELT OF WEAK ASCENT AHEAD OF CNTRL PLAINS SHORTWAVE TROUGH FROM CNTRL AR SWWD THROUGH THE ARKLATEX INTO SERN TX...WHICH SHOULD CONTINUE EWD TODAY. GIVEN THAT STRONGEST LARGE-SCALE FORCING AND LOW-LEVEL CONVERGENCE WILL REMAIN N AND NE OF REGION...THERE IS SOME UNCERTAINTY REGARDING EVOLUTION OF CONVECTIVE CLUSTER OVER NERN TX/NWRN LA...AS WELL AS POTENTIAL FOR ADDITIONAL DEVELOPMENT ALONG SURFACE FRONT. VISIBLE SATELLITE IMAGERY WOULD SUGGEST THAT PRE-FRONTAL BOUNDARY-LAYER IS BECOMING CONDITIONED SUCH THAT ADDITIONAL DEEP CONVECTION MAY BECOME INCREASINGLY LIKELY THROUGH THE AFTERNOON FROM WRN/CNTRL AR SWWD INTO ERN TX. GIVEN THE MODERATE INSTABILITY AND PRESENCE OF 50-60 KT WSWLY MID-LEVEL FLOW...POTENTIAL WILL EXIST FOR THE DEVELOPMENT AND MAINTENENCE OF SEVERE STORMS...INCLUDING SUPERCELLS CAPABLE OF LARGE HAIL...DAMAGING WINDS AND POSSIBLY A COUPLE OF TORNADOES. FARTHER TO THE E...SMALL MCS CONTINUES THIS AFTERNOON OVER NRN MS/WRN TN WITH RECENT DEVELOPMENT NEWD INTO MIDDLE TN...TO THE S OF WARM FRONT LIFTING NWD THROUGH REGION. HERE TOO...AIR MASS HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-1500 J/KG. ADDITIONALLY...CURRENT BNA VWP INDICATES A FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED STORMS INCLUDING SUPERCELLS. THUS...EXPECT THAT ONGOING MCS SHOULD CONTINUE TO INTENSIFY THROUGH THE AFTERNOON WITH ADDITIONAL SEVERE STORMS POSSIBLE DOWNSTREAM FROM THIS COMPLEX. WHILE LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS...A BRIEF TORNADO OR TWO WILL BE POSSIBLE. ..MEAD.. 04/02/2006  From SWODY1 at goshenarc.org Mon Apr 3 01:18:52 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 21:18:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030116 SWODY1 SPC AC 030114 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0814 PM CDT SUN APR 02 2006 VALID 030100Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHERN INDIANA...SOUTHEAST MISSOURI...NORTHEAST ARKANSAS...WESTERN TENNESSEE AND WESTERN KENTUCKY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS AND WSWWD INTO NERN TX... ...OH/TN VALLEYS... LINE OF STORMS -- WITH EMBEDDED SUPERCELLS -- IS CURRENTLY ARCING SEWD FROM SRN WI INTO SRN INDIANA. MORE ISOLATED SUPERCELLS THEN CONTINUE ARCING SWD/SWWD ACROSS WRN KY INTO NERN AR/WRN TN. WIDESPREAD SEVERE WEATHER IS OCCURRING WITH THIS AREA OF STORMS...INCLUDING REPORTS OF SEVERAL LARGE/DAMAGING TORNADOES. SURFACE LOW IS NOW OBSERVED OVER ERN IA...WITH A WARM FRONT EXTENDING SEWD ACROSS NRN AND ERN IL/SRN INDIANA INTO NRN KY. MEANWHILE...COLD FRONT EXTENDS FROM THE LOW SSEWD ACROSS WRN IL/SERN MO AND THEN SWWD ACROSS NRN AND WRN AR INTO NERN TX. WHILE AIRMASS AHEAD OF COLD FRONT REMAINS MOIST/UNSTABLE...MUCH COOLER/DRIER AIRMASS EXISTS NE OF WARM FRONT. THIS LEAVES ONLY A NARROW WARM SECTOR ACROSS CENTRAL AND SRN IL...WHILE WARM SECTOR BROADENS TO INCLUDE MOST OF KY AND INTO THE TN/LOWER MS VALLEYS. AS STORMS MOVE EWD/ENEWD ACROSS NERN IL INTO NRN AND CENTRAL INDIANA...DAMAGING WIND/TORNADO THREAT SHOULD BEGIN TO SLOWLY DIMINISH WITH TIME...DUE TO MUCH MORE STABLE AIRMASS NE OF WARM FRONT. HOWEVER...THREAT FOR HAIL MAY PERSIST WELL EWD -- PERHAPS INTO SRN LOWER MI/OH AND PERHAPS WRN PA BY THE END OF THE PERIOD. MEANWHILE S OF WARM FRONT AND E OF COLD FRONT...MOIST AND VERY UNSTABLE WARM-SECTOR AIRMASS PERSISTS...WITH 1500 TO 3000 J/KG MEAN-LAYER CAPE FROM NERN TX NEWD ACROSS AR INTO WRN AND CENTRAL KY...MUCH OF TN...AND NRN PORTIONS OF MS AND AL. IN ADDITION TO FAVORABLE INSTABILITY...DEEP-LAYER WIND FIELD REMAINS QUITE STRONG...INCLUDING 80-PLUS KT H5 JET STREAK NOW CENTERED OVER SRN MO...WHICH IS FORECAST TO SHIFT ACROSS THE OH/TN VALLEYS OVERNIGHT. GIVEN FAVORABLE DEEP-LAYER SHEAR...EXPECT SCATTERED SUPERCELLS OVER NERN AR/WRN KY/WRN TN TO CONTINUE FOR SEVERAL HOURS...WHILE MORE LINEAR STORMS CONTINUE EWD ACROSS THE OH VALLEY REGION. ALONG WITH A CONTINUED THREAT FOR STRONG TORNADOES AND LARGE HAIL...RELATIVELY WIDESPREAD DAMAGING WIND EVENT MAY ALSO EVOLVE WITH TIME. STORMS MAY CROSS THE APPALACHIANS BY THE END OF THE PERIOD...THOUGH SEVERE THREAT SHOULD REMAIN CONFINED TO AREAS W OF THE APPALACHIAN CREST...AS MUCH DRIER BOUNDARY LAYER EXISTS E OF THE MOUNTAINS. ..GOSS.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 01:22:45 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 21:22:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030120 SWODY1 SPC AC 030119 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0819 PM CDT SUN APR 02 2006 VALID 030100Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHERN INDIANA...SOUTHEAST MISSOURI...NORTHEAST ARKANSAS...WESTERN TENNESSEE AND WESTERN KENTUCKY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS AND WSWWD INTO NERN TX... CORRECTED FOR MODERATE RISK LINE ...OH/TN VALLEYS... LINE OF STORMS -- WITH EMBEDDED SUPERCELLS -- IS CURRENTLY ARCING SEWD FROM SRN WI INTO SRN INDIANA. MORE ISOLATED SUPERCELLS THEN CONTINUE ARCING SWD/SWWD ACROSS WRN KY INTO NERN AR/WRN TN. WIDESPREAD SEVERE WEATHER IS OCCURRING WITH THIS AREA OF STORMS...INCLUDING REPORTS OF SEVERAL LARGE/DAMAGING TORNADOES. SURFACE LOW IS NOW OBSERVED OVER ERN IA...WITH A WARM FRONT EXTENDING SEWD ACROSS NRN AND ERN IL/SRN INDIANA INTO NRN KY. MEANWHILE...COLD FRONT EXTENDS FROM THE LOW SSEWD ACROSS WRN IL/SERN MO AND THEN SWWD ACROSS NRN AND WRN AR INTO NERN TX. WHILE AIRMASS AHEAD OF COLD FRONT REMAINS MOIST/UNSTABLE...MUCH COOLER/DRIER AIRMASS EXISTS NE OF WARM FRONT. THIS LEAVES ONLY A NARROW WARM SECTOR ACROSS CENTRAL AND SRN IL...WHILE WARM SECTOR BROADENS TO INCLUDE MOST OF KY AND INTO THE TN/LOWER MS VALLEYS. AS STORMS MOVE EWD/ENEWD ACROSS NERN IL INTO NRN AND CENTRAL INDIANA...DAMAGING WIND/TORNADO THREAT SHOULD BEGIN TO SLOWLY DIMINISH WITH TIME...DUE TO MUCH MORE STABLE AIRMASS NE OF WARM FRONT. HOWEVER...THREAT FOR HAIL MAY PERSIST WELL EWD -- PERHAPS INTO SRN LOWER MI/OH AND PERHAPS WRN PA BY THE END OF THE PERIOD. MEANWHILE S OF WARM FRONT AND E OF COLD FRONT...MOIST AND VERY UNSTABLE WARM-SECTOR AIRMASS PERSISTS...WITH 1500 TO 3000 J/KG MEAN-LAYER CAPE FROM NERN TX NEWD ACROSS AR INTO WRN AND CENTRAL KY...MUCH OF TN...AND NRN PORTIONS OF MS AND AL. IN ADDITION TO FAVORABLE INSTABILITY...DEEP-LAYER WIND FIELD REMAINS QUITE STRONG...INCLUDING 80-PLUS KT H5 JET STREAK NOW CENTERED OVER SRN MO...WHICH IS FORECAST TO SHIFT ACROSS THE OH/TN VALLEYS OVERNIGHT. GIVEN FAVORABLE DEEP-LAYER SHEAR...EXPECT SCATTERED SUPERCELLS OVER NERN AR/WRN KY/WRN TN TO CONTINUE FOR SEVERAL HOURS...WHILE MORE LINEAR STORMS CONTINUE EWD ACROSS THE OH VALLEY REGION. ALONG WITH A CONTINUED THREAT FOR STRONG TORNADOES AND LARGE HAIL...RELATIVELY WIDESPREAD DAMAGING WIND EVENT MAY ALSO EVOLVE WITH TIME. STORMS MAY CROSS THE APPALACHIANS BY THE END OF THE PERIOD...THOUGH SEVERE THREAT SHOULD REMAIN CONFINED TO AREAS W OF THE APPALACHIAN CREST...AS MUCH DRIER BOUNDARY LAYER EXISTS E OF THE MOUNTAINS. ..GOSS.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 06:02:03 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 02:02:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030559 SWODY1 SPC AC 030557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT MON APR 03 2006 VALID 031200Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHEAST VIRGINIA/EASTERN NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE E COAST STATES FROM THE DELMARVA REGION SSWWD INTO NERN GA... ...SYNOPSIS... MID-LEVEL TROUGH IS FORECAST TO STRENGTHEN AND TAKE ON A MORE NEGATIVE TILT WITH TIME AS IT MOVES EWD ACROSS THE APPALACHIANS EARLY...AND THEN ACROSS THE E COAST STATES THROUGH THE END OF THE PERIOD. STRONG DEEP-LAYER WIND FIELD -- INCLUDING 70 KT MID-LEVEL JET STREAK -- WILL MOVE ACROSS GA AND THE CAROLINAS DURING THE AFTERNOON. AT THE SURFACE...BOUNDARY LAYER MOISTENING WILL OCCUR DURING THE DAY...AHEAD OF APPROACHING COLD FRONT WHICH SHOULD CREST THE APPALACHIANS BY EARLY AFTERNOON. AS CONVECTION REDEVELOPS/INTENSIFIES AHEAD OF THIS BOUNDARY...THREAT FOR SEVERE WEATHER WILL INCREASE ACROSS THE E COAST STATES FROM THE DELMARVA REGION SWD TO GA. ...E COAST STATES... SIGNIFICANT SEVERE WEATHER EPISODE APPEARS LIKELY THIS PERIOD FROM MD/DE/VA SWD INTO NERN GA...AS NEGATIVELY-TILTED UPPER TROUGH MOVES ACROSS THE ERN CONUS. BOUNDARY LAYER IS FORECAST TO MOISTEN THROUGH EARLY AFTERNOON...BENEATH STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH APPROACHING UPPER TROUGH. THIS COMBINED WITH DAYTIME HEATING SHOULD PUSH MEAN-LAYER CAPE VALUES INTO THE 1000 TO 2000 J/KG RANGE BY EARLY AFTERNOON. ATTM...IT APPEARS THAT CONVECTION NOW OVER THE TN VALLEY REGION WILL RE-INTENSIFY AHEAD OF FRONT...INITIALLY FROM WRN VA SSWWD INTO WRN SC AROUND 18Z. DEVELOPING STORMS SHOULD RAPIDLY BECOME SEVERE...AS STRONG DEEP-LAYER WIND FIELD WILL BE IN PLACE ACROSS THIS REGION. STORMS SHOULD ORGANIZE WITH TIME INTO A LINE -- WITH EMBEDDED LEWPS/BOWS/SUPERCELLS ACROSS VA AND NC...WHERE UPPER FORCING SHOULD BE STRONGER. FURTHER S INTO SC AND NERN GA...MORE ISOLATED/CELLULAR CONVECTION IS EXPECTED...WITH SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS. GIVEN FORECAST COMBINATION OF SHEAR AND INSTABILITY...LARGE HAIL AND DAMAGING WINDS APPEAR LIKELY. IN ADDITION...LOW-LEVEL SPEED SHEAR SHOULD BE SUFFICIENT FOR TORNADOES -- WITH A THREAT FOR A FEW STRONGER TORNADOES MOST LIKELY ACROSS THE ERN CAROLINAS AND SERN VA WHERE MODELS SUGGEST BACKED/SSELY SURFACE WINDS AHEAD OF APPARENT LEE TROUGH. SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING...BEFORE STORMS MOVE OFF THE COAST INTO THE WRN ATLANTIC. ..GOSS/JEWELL.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 12:53:27 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 08:53:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031251 SWODY1 SPC AC 031249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT MON APR 03 2006 VALID 031300Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF THE ERN CAROLINAS INTO SERN VA TODAY AND EARLY THIS EVENING... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF AL/GA NWD INTO THE UPPER OH RIVER VALLEY AND MID ATLANTIC... ...DELMARVA INTO PORTIONS OF THE SOUTHEAST... SIGNIFICANT MID/UPPER LEVEL TROUGH NOW DIGGING EWD ACROSS THE MID SOUTH WILL EJECT RAPIDLY ENEWD ACROSS THE CENTRAL/SRN APPALACHIANS TODAY. ASSOCIATED 70+ KT MID LEVEL JET IS FORECAST BY ALL THE MODELS TO OVERSPREAD NRN/ERN GA AND CENTRAL SC THROUGH 21Z... MAINTAINING ENHANCED LARGE SCALE ASCENT AND VERY STRONG SHEAR ACROSS THIS REGION. IN ADDITION...PLUME OF ELEVATED-MIXED LAYER AIR HAS OVERSPREAD MUCH OF THE SOUTHEAST AND WILL FEED NEWD INTO THE CAROLINAS TODAY. TLH AND JAX BOTH INDICATE 8+ C/KM LAPSE RATES FROM H7-H5...WITH 7+ C/KM AT CHS. COMBINED WITH VERY STRONG ASCENT AND STRENGTHENING SHEAR...A SIGNIFICANT SEVERE THUNDERSTORM THREAT IS EXPECTED TO UNFOLD INTO THE CENTRAL/ERN CAROLINAS INTO SERN VA TODAY. MCS CONTINUES FROM SUNDAY EVENINGS SEVERE EVENT INTO THE SRN APPALACHIANS THIS MORNING...WHICH WILL LIKELY CONTINUE SPREADING EWD INTO THE PIEDMONT/CENTRAL GA EARLY TODAY. ACTIVITY HAS WEAKENED OVER THE PAST HOUR OR TWO AS CONSOLIDATED OUTFLOW BOUNDARY CONTINUES TO UNDERCUT STRONGER STORMS. HOWEVER...VERY STEEP LAPSE RATES IN PLACE THIS MORNING AND 40-50 KT EFFECTIVE SHEAR WILL MAINTAIN A THREAT OF LARGE HAIL AND ISOLATED DAMAGING WINDS INTO THE MID MORNING WITH THIS ACTIVITY. BY 18Z...STORMS WILL INTENSIFY FROM CENTRAL VA INTO CENTRAL SC ALONG REMNANTS OF THIS OUTFLOW BOUNDARY AND/OR AHEAD OF APPROACHING SURFACE COLD FRONT NOW OVER CENTRAL KY/TN. FORECAST SOUNDINGS INDICATE MLCAPE WILL EXCEED 1500 J/KG INTO THE PIEDMONT...WHERE STRONG LOW AND DEEP LAYER SHEAR AND STEEP LAPSE RATES WILL ENHANCE STORM SCALE ORGANIZATION. ACTIVITY WILL QUICKLY EVOLVE INTO SUPERCELL AND SMALL BOW ECHO STRUCTURES AND RACE EWD THROUGH THE EARLY EVENING. VERY LARGE HAIL AND TORNADOES ARE EXPECTED TO ACCOMPANY THESE STORMS. TORNADO THREAT MAY BE ENHANCED NEAR E-W ORIENTED OUTFLOW BOUNDARY FROM EARLIER STORMS NOW OVER PORTIONS OF SERN NC. WIND DAMAGE THREAT MAY ALSO BECOME WIDESPREAD AS BROKEN SQUALL LINE EVOLVES LATER TODAY. ...ERN OH INTO WRN PA/NRN WV... VERY STRONG LARGE SCALE ASCENT AHEAD OF SURFACE COLD FRONT AND INTENSE MID/UPPER LEVEL TROUGH WILL INTERACT WITH LOWER TO MID 50F SURFACE DEW POINTS OVER THE UPPER OH RIVER VALLEY/LOWER GREAT LAKES THIS MORNING. MODIFIED 12Z SOUNDING AT ILN INDICATED MID/UPPER 60F SURFACE TEMPERATURES WILL SUPPORT MARGINAL SURFACE BASED INSTABILITY. IN ADDITION...VERY STEEP LAPSE RATES AND SIGNIFICANT LOW AND DEEP LAYER SHEAR SHOULD SUPPORT LOW TOPPED SEVERE THUNDERSTORMS...POSSIBLY DEVELOPING BY THE MID MORNING. THIS ACTIVITY WILL POSE DAMAGING WINDS/LARGE HAIL THREATS EWD TOWARDS THE APPALACHIANS...WITH ISOLATED TORNADOES ALSO POSSIBLE. ...CENTRAL GULF COAST STATES INTO ERN TX... AIR MASS WILL REMAIN VERY UNSTABLE ALONG AND SOUTH OF SURFACE COLD FRONT FORECAST TO MOVE SWD INTO CENTRAL/SRN MS AND SRN LA/ERN TX THIS AFTERNOON. THOUGH CAPPING WILL REMAIN PROBLEMATIC FOR INITIATION GIVEN LACK OF LARGE SCALE ASCENT...HEATING AND CONVERGENCE MAY ALLOW A FEW STORMS TO DEVELOP LATER TODAY. JAN/S 12Z SOUNDING REMAINS VERY FAVORABLE FOR SEVERE THUNDERSTORMS... SHOULD ACTIVITY DEVELOP IN GENERAL SUBSIDENT REGIME. THEREFORE... AT LEAST LOW SEVERE PROBABILITIES WARRANTED WSWWD ALONG THIS BOUNDARY INTO PORTIONS OF ERN TX. ..EVANS/JEWELL.. 04/03/2006  From SwoDy1 at goshenarc.org Mon Apr 3 16:39:30 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 12:39:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031637 SWODY1 SPC AC 031635 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 AM CDT MON APR 03 2006 VALID 031630Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER NERN GA..NC..SC..AND SOUTH CENTRAL/SERN VA... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SERN STATES INTO THE UPPER OH VALLEY AND MID ATLANTIC REGION... ...WIDESPREAD SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING FROM THE SOUTHERN AND CENTRAL APPALACHIANS INTO THE CAROLINAS AND VIRGINIA.... ...SYNOPSIS... VIGOROUS UPPER TROUGH EXTENDING FROM THE LOWER GREAT LAKES INTO THE TN VALLEY IS EXPECTED TO BECOME NEGATIVELY TILTED AS IT MOVES TOWARD THE CAROLINAS AND VA...AS UPSTREAM LOW OVER NWRN ONTARIO DIGS SEWD. AT THE SURFACE...PRIMARY LOW OVER THE LOWER LAKES WILL MOVE SLOWLY EWD WITH SECONDARY CYCLOGENESIS EXPECTED OVER THE DELMARVA REGION LATE THIS AFTERNOON AS UPPER LEVEL DIVERGENCE INCREASES IN LEFT EXIT REGION OF MID/UPPER LEVEL JET STREAK MOVING ACROSS THE CAROLINAS. SURFACE COLD FRONT FROM LAKE ERIE SWD THROUGH ERN PARTS OF OH/KY/TN SWWD ACROSS NRN AL AND CENTRAL MS IS FORECAST TO PROGRESS RAPIDLY EWD...REACHING CENTRAL PARTS OF PA..VA..THE CAROLINAS INTO SWRN GA AND WWD ALONG THE GULF COAST BY THIS EVENING...AND OFF THE ATLANTIC COAST TONIGHT. ...SRN APPALACHIANS INTO CAROLINAS AND VIRGINIA... COMPLEX CONVECTIVE SCENARIO HAS BEEN UNFOLDING THIS MORNING WITH EWD MOVING BAND OF PRE-FRONTAL CONVECTION FROM ERN VA SWD INTO GA. ALTHOUGH ISOLATED STRONG/SEVERE STORMS ARE CONTINUING OVER ERN NC...MOST OF THIS ACTIVITY HAS DIMINISHED IN INTENSITY WITH THINNING CLOUDS EVIDENT FROM WRN NC INTO SC AND CENTRAL GA. ASSOCIATED OUTFLOW BOUNDARY EXTENDS ACROSS THE ERN CAROLINAS WWD INTO NRN GA...WITH SC/GA PART OF THE BOUNDARY EXPECTED TO WEAKEN AS SURFACE WINDS BACK TO A MORE SWLY COMPONENT IN RESPONSE TO ONGOING PRESSURE FALLS. 12Z SOUNDINGS SHOWED A PLUME OF STEEP MID LEVEL LAPSE RATES EXTENDING EWD FROM THE LOWER MS VALLEY TO THE SRN ATLANTIC COAST WHICH IS ENHANCING POTENTIAL INSTABILITY ACROSS THE REGION. STRONG INSOLATION IN ADVANCE OF THE AFOREMENTIONED COLD FRONT WILL CONTRIBUTE TO ADDITIONAL DESTABILIZATION THIS AFTERNOON...WITH MLCAPE OF 1500 J/KG EXPECTED ALONG AN AXIS FROM GA INTO NC. CONVECTION IS DEVELOPING FROM THE UPPER OH VALLEY INTO NERN TN ATTM...AND DEVELOPING CU FIELD IS EVIDENT SWWD INTO NWRN GA/NRN AL/CENTRAL MS. AS CAP CONTINUES TO WEAKEN OVER THE SRN APPALACHIANS REGION...THUNDERSTORMS ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON. STRONG DEEP LAYER SHEAR ACROSS THE AREA WILL ENHANCE CONVECTIVE ORGANIZATION AND INTENSITY. STORM COVERAGE WILL LIKELY INCREASE THROUGH THE MID-LATE AFTERNOON ALONG/AHEAD OF THE FRONT...WITH POTENTIAL FOR SEVERAL BANDS OF STRONG/SEVERE STORMS WITH EMBEDDED SUPERCELLS AND BOW SEGMENTS. REMNANTS OF MORNING OUTFLOW BOUNDARY/THERMAL GRADIENT ARE EXPECTED TO LIFT SLOWLY NWD FROM NRN GA ACROSS UPSTATE SC..CENTRAL NC AND EXTREME SERN VA BY LATER THIS AFTERNOON...PROVIDING AN ADDITIONAL MESOSCALE FOCUS FOR SEVERE THUNDERSTORMS. A FEW TORNADOES WILL BE POSSIBLE...ESPECIALLY OVER PARTS OF THE CAROLINAS AND SERN VA WHERE LOW LEVEL SHEAR WILL BE STRONGEST...ALONG WITH VERY LARGE HAIL AND DAMAGING WIND GUSTS. SEVERE THREAT WILL SPREAD EWD TOWARD THE COAST BY THIS EVENING BEFORE ENDING FROM THE WEST BY 03-06Z. ...UPPER OH VALLEY INTO CENTRAL APPALACHIANS... A BAND OF STRONG/SEVERE STORMS HAS DEVELOPED JUST AHEAD OF THE COLD FRONT FROM EXTREME WRN PA INTO ERN KY. THIS ACTIVITY IS EXPECTED TO SPREAD EWD IN ADVANCE OF THE STRONG UPPER LOW APPROACHING WRN LAKE ERIE. ALTHOUGH MORE EXTENSIVE CLOUDS OVER PA MAY INHIBIT DIURNAL HEATING/DESTABILIZATION THIS AFTERNOON... STRONG WINDS IMMEDIATELY ABOVE THE SURFACE WILL AID POTENTIAL FOR DAMAGING WIND GUSTS THROUGH DOWNWARD TRANSFER OF HORIZONTAL MOMENTUM IN CONVECTIVE DOWNDRAFTS. IN ADDITION...THE STRONG LOW LEVEL SHEAR/HELICITY SUGGESTS POTENTIAL FOR A FEW TORNADOES. THIS ACTIVITY WILL LIKELY CONTINUE EWD THROUGH THE AFTERNOON HOURS. ..WEISS/CROSBIE.. 04/03/2006  From SwoDy1 at goshenarc.org Mon Apr 3 20:19:32 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 16:19:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032015 SWODY1 SPC AC 032013 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0313 PM CDT MON APR 03 2006 VALID 032000Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS SERN/S-CENTRAL VA...EXTREME S-CENTRAL MD...NC...NRN SC... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM SRN AL TO CENTRAL PA... ...SYNOPSIS... HIGH AMPLITUDE TROUGH -- EVIDENT IN MOISTURE CHANNEL IMAGERY FROM SRN ONT SWD TO ERN TN -- SHOULD MOVE NEWD OVER CENTRAL APPALACHIANS THROUGH REMAINDER PERIOD AS UPPER LEVEL LOW DIGS SEWD FROM NWRN ONT. SMALLER SHORTWAVE NOW MOVING THROUGH BASE OF BROADER SCALE TROUGH OVER SRN APPALACHIANS WILL EJECT NEWD OVER ERN NC/SERN VA EARLY TONIGHT. ASSOCIATED/OCCLUDED SFC LOW WILL MOVE NEWD TOWARD SERN QUE. OCCLUDED FRONT - NOW ANALYZED FROM SRN ONT ACROSS NWRN PA -- SHOULD MOVE EWD ACROSS NY AND NRN PA THROUGH EVENING...WHILE TRAILING COLD FRONT MOVES ACROSS MUCH OF REMAINDER MID-ATLANTIC...VA...CAROLINAS...NRN GA AND AL. WARM FRONT -- ANALYZED FROM SWRN PA SEWD ACROSS ERN VA TO SRN CHESAPEAKE BAY...SHOULD MOVE NEWD ACROSS POTOMAC RIVER AND INTO PORTIONS SRN/CENTRAL MD. ...TIDEWATER REGION THROUGH CAROLINAS/GA... REF WW 147 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST SITUATION ACROSS PORTIONS SRN APPALACHIANS AND ADJACENT PIEDMONT ZONES OF GA/CAROLINAS. REF MESOSCALE DISCUSSION 421 AND WW 148 FOR NEAR-TERM POTENTIAL FROM CENTRAL/NRN NC INTO SRN VA. DAMAGING WIND POTENTIAL WILL CONTINUE THROUGH THIS EVENING WITH CONVECTION AHEAD OF FRONT...AND TORNADOES STILL ARE A CONCERN FROM COASTAL NC INTO PORTIONS VA/SRN MD TIDEWATER REGION. SFC ANALYSIS INDICATES SUBSTANTIAL MIXING-OUT OF BOUNDARY LAYER MOISTURE AHEAD OF PRIMARY CONVECTIVE BAND -- WITH DEW POINTS UPPER 40S TO MID 50S F NOW COMMON ACROSS MUCH OF PIEDMONT FROM VA-GA. SUCH DRYING IN PROSPECTIVE SUBCLOUD LAYER MAY RESULT IN TORNADO POTENTIAL BEING REDUCED...BY ENCOURAGING EVAPORATIVELY COOLED OUTFLOW PLUMES IN SUBCLOUD LAYERS. HOWEVER...THIS ALSO ENCOURAGES DOWNDRAFT ACCELERATION THROUGH BOUNDARY LAYER...AND ENHANCED POTENTIAL FOR DAMAGING GUSTS. THEREFORE WE WILL MAINTAIN MDT RISK...WHOSE THRESHOLD ALREADY WAS BASED ON DAMAGING WIND PROBABILITIES. DEEP-LAYER SHEAR WILL REMAIN FAVORABLE FOR SEVERE ACROSS ENTIRE REGION -- EVEN WHERE FLOW HAS VEERED TO SWLY -- GIVEN STRENGTH OF MID/UPPER LEVEL WINDS. HOWEVER...GREATEST COMBINATION OF INSTABILITY...MOISTURE AND SHEAR SHOULD BE FROM ERN NC THROUGH ERN VA AND PERHAPS SRN MD. LARGEST TORNADO PROBABILITIES WILL BE SHUNTED EWD TOWARD MORE ROBUST MOISTURE INVOF COAST AND NEAR WARM FRONT...WHERE RELATIVELY BACKED SFC FLOW ALSO ENHANCES DEEP-LAYER SHEAR...AND SFC DEW POINTS SHOULD REMAIN IN UPPER 50S TO LOW 60S IN MANY AREAS. EARLIER MCS HAS LEFT BEHIND POOL OF OUTFLOW AIR IN ERN NC THAT IS BEING HEATED/MODIFIED ATTM. LOW LEVEL DRY ADVECTION AND MIXING WILL ERODE WRN EDGE OF THIS PLUME SOMEWHAT...BUT VORTICITY/SHEAR SHOULD REMAIN MAXIMIZED FROM THIS PLUME NWD TO WARM FRONTAL ZONE. ANY RELATIVELY DISCRETE ACTIVITY DEVELOPING IN WARM SECTOR AHEAD OF MAIN CONVECTIVE BAND MAY INTERACT WITH EITHER FAVORABLY MODIFIED OUTFLOW AIR OR WARM FRONT...WHERE BACKED FLOW...ENLARGED HODOGRAPHS...AND LOWER LCL ARE EXPECTED. VIS IMAGERY SHOWS BOUNDARY LAYER BILLOWS OVER E-CENTRAL VA ATTM...INDICATING CAPPING...HOWEVER...AIR MASS SHOULD CONTINUE TO DESTABILIZE WITH INSOLATION OCCURRING IN WAKE OF MORNING CONVECTIVE/CLOUD AREA. ..N-CENTRAL APPALACHIANS/MID-ATLANTIC... ORGANIZED LINE OF TSTMS...INVOF OCCLUDED/COLD FRONTAL ZONE...SHOULD CONTINUE MOVING EWD ACROSS PORTIONS PA/WRN NY THROUGH REMAINDER AFTERNOON INTO EARLY EVENING. MAIN THREAT IS WIND DAMAGE. GIVEN STRENGTH OF VERTICAL SHEAR ACROSS THIS REGION... ISOLATED HAIL AND A TORNADO OR TWO ALSO REMAIN POSSIBLE...PARTICULARLY IN ASSOCIATION WITH EMBEDDED BOWS/MESOCYCLONES. REF WW 146 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR NEAR TERM SITUATION. ACTIVITY SHOULD DIMINISH THIS EVENING AS IT MOVES INTO LOW THETAE BOUNDARY LAYER THAT WILL CONTINUE TO CHARACTERIZE MUCH OF ERN PA...CENTRAL NY AND BEYOND. ..EDWARDS.. 04/03/2006  From SwoDy1 at goshenarc.org Tue Apr 4 00:59:09 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 20:59:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040057 SWODY1 SPC AC 040055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT MON APR 03 2006 VALID 040100Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE MIDDLE ATLANTIC AND SERN U.S.... ...MIDDLE ATLANTIC/SERN U.S... CONVECTION CONTINUES TO DECREASE IN AREAL COVERAGE AND INTENSITY AS IT SPREADS ACROSS THE MIDDLE ATLANTIC REGION THIS EVENING. 00Z SOUNDING FROM WAL WAS NOT PARTICULARLY UNSTABLE WITH ONLY 300 J/KG MUCAPE...ALTHOUGH VERTICAL SHEAR WAS MORE THAN ADEQUATE FOR SUSTAINING ORGANIZED UPDRAFTS. PROXIMITY TO COOLER MARINE LAYER NEAR THE COAST DOES NOT FAVOR STRENGTHENING OF SQUALL LINE...THUS A GRADUAL WEAKENING TREND SHOULD CONTINUE THROUGH THE EVENING HOURS. FARTHER SOUTH...VEERED FLOW ACROSS GA INTO THE CAROLINAS HAS AIDED STEEP LAPSE RATE ENVIRONMENT THAT ENHANCED TEMP/DEW POINT DEPRESSIONS AHEAD OF CONVECTION. HOWEVER...WITH LOSS OF HEATING INSTABILITY HAS DECREASED AND THIS SHOULD FACILITATE CONTINUED WEAKENING OVER THE NEXT FEW HOURS. LARGE HAIL AND LOCALLY STRONG WINDS MAY ACCOMPANY ONGOING ACTIVITY UNTIL THIS TRANSITION OCCURS. ..DARROW.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 05:52:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 01:52:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040549 SWODY1 SPC AC 040548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1248 AM CDT TUE APR 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CA... ...CA... LATE EVENING SATELLITE IMAGERY CLEARLY DEPICTS CENTER OF UPPER CIRCULATION OVER THE ERN PACIFIC NEAR 35N/132W...MOVING SEWD TOWARD THE CNTRL CA COAST. 00Z MODEL GUIDANCE SUGGESTS STRONG UPPER JET...APPROACHING 100KT...WILL MOVE INTO SRN CA DURING THE LATE AFTERNOON/EVENING WITH FOCUSED DIVERGENCE ALOFT EXPECTED TO SPREAD ACROSS THE SAN JOAQUIN VALLEY. STRONG ASCENT WILL UNDOUBTEDLY AID MID-HIGH LEVEL MOISTENING WHICH WILL LIMIT BOUNDARY LAYER HEATING...ESPECIALLY IN REGIONS OF PRECIPITATION. ALTHOUGH HEATING SHOULD BE LIMITED...FORECAST SHEAR PROFILES ARE QUITE STRONG...WITH VEERING FLOW THROUGH A DEEP LAYER EXPECTED TO SUPPORT STORM ROTATION WITH STRONGER UPDRAFTS. IT APPEARS SUFFICIENT INSTABILITY...ROUGHLY 500 J/KG...WILL DEVELOP FOR THUNDERSTORM DEVELOPMENT AND SUPERCELL STRUCTURES MAY EVOLVE...MAINLY IN THE VALLEY. HAIL...STRONG WINDS...AND POSSIBLY ISOLATED TORNADOES MAY ACCOMPANY THE STRONGER STORMS. ...SOUTHERN FL PENINSULA... STRONG HEATING WILL PROVE INSTRUMENTAL FOR THUNDERSTORM DEVELOPMENT ACROSS THE SRN FL PENINSULA TODAY AS WEAK CONVERGENCE WILL BE NOTED ALONG SWD MOVING WIND SHIFT. WITH DEEP W-NWLY FLOW IT APPEARS SERN TIP OF THE PENINSULA WILL BE THE PRIMARY FOCUS FOR ISOLATED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING MAINLY LARGE HAIL AND GUSTY WINDS. WEAKLY FOCUSED BOUNDARY AND LIMITED COVERAGE WARRANT LOW PROBABILITIES FOR CONVECTION THAT DEVELOPS DURING THE AFTERNOON/EARLY EVENING HOURS. ...CNTRL PLAINS/MID MS VALLEY... STRENGTHENING LOW-MID LEVEL WARM ADVECTION WILL LIKELY ENHANCE ELEVATED CONVECTIVE THREAT ACROSS ERN KS/NERN OK INTO MO/AR LATE IN THE PERIOD. WEAK INSTABILITY AND COVERAGE WILL LIMIT SEVERE POTENTIAL. ..DARROW.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 12:48:29 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 08:48:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041244 SWODY1 SPC AC 041242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0742 AM CDT TUE APR 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF SRN CA... ...SRN CA... PROMINENT MID/UPPER LEVEL LOW NOW NEAR 34N/130W WILL CONTINUE APPROACHING THE SRN CA COAST TODAY AND MOVE INLAND LATER TONIGHT. SIGNIFICANT MID/UPPER LEVEL JET WILL LIKEWISE DEVELOP ACROSS FAR SRN CA DURING THE PERIOD WITH 100+ KT AT H5 NOSING ACROSS THE SRN CA COAST BY 06Z. THOUGH INSTABILITY WILL REMAIN SOMEWHAT LIMITED... COOLING ALOFT AND MODEST AFTERNOON HEATING ARE STILL FORECAST TO SUPPORT WEAK SURFACE-BASED INSTABILITY ALONG THE SRN CA COAST AND INTO THE SRN SAN JOAQUIN VALLEY THIS AFTERNOON/EVENING...WITH INSTABILITY PERSISTING AFTER DARK NEAR THE COAST WITHIN VERY COLD POCKET ALOFT. THOUGH OVERALL SEVERE THREAT APPEARS MARGINAL DUE TO LIMITED INSTABILITY...VERY STRONG SHEAR WILL SUPPORT A THREAT OF LOW TOPPED SUPERCELLS AND LINES. ALONG WITH MARGINALLY SEVERE HAIL...THIS WILL RESULT IN POSSIBILITY OF DAMAGING WINDS AND BRIEF TORNADOES. ...CENTRAL FL... SURFACE FRONT WILL STALL ACROSS CENTRAL FL TODAY AS STRONG UPPER SYSTEM LIFTS INTO THE NORTHEASTERN U.S. SOUNDINGS YESTERDAY EVENING AND THIS MORNING INDICATE RATHER STEEP LAPSE RATES REMAIN IN PLACE AHEAD OF THIS FRONT. COMBINATION OF HEATING AND WEAK SURFACE CONVERGENCE SHOULD OVERCOME CAPPING WITHIN MODERATELY UNSTABLE AIR MASS DURING THE MID/LATE AFTERNOON. THOUGH SHEAR WILL REMAIN FAIRLY WEAK /SFC-6 KM SHEAR AOB 25 KT/...STEEP LAPSE RATES AND MODERATE INSTABILITY SHOULD SUPPORT A LOW PROBABILITY THREAT OF ISOLATED LARGE HAIL/DAMAGING WINDS WITH STRONGER CORES INTO THE EARLY EVENING. CONVECTION AND ANY SEVERE THREAT WILL QUICKLY DIMINISH AFTER DARK. ...SRN KS/NRN OK INTO SWRN MO/WRN AR... SSWLY LLJ STRENGTHENS OVERNIGHT OUT OF THE SRN HIGH PLAINS AND NOSES INTO NRN OK/SRN KS AFTER 06Z. GFS AND NAM BOTH DEVELOP 40+ KT H85 JET...BUT DIFFER SLIGHTLY ON ITS LOCATION AND AREA OF SUBSEQUENT ELEVATED THUNDERSTORM DEVELOPMENT EARLY WEDNESDAY MORNING. REGARDLESS...STEEP MID LEVEL LAPSE RATES WILL RESIDE ABOVE A MOISTENING BOUNDARY LAYER WITH H85 DEW POINTS AOA 8C LATE IN THE PERIOD. FORECAST SOUNDINGS INDICATE MUCAPE APPROACHING 750 J/KG WITH 40-50 KT OF CLOUD LAYER SHEAR. THEREFORE...STORMS MAY DEVELOP MID LEVEL ROTATION AND SUPPORT MARGINALLY SEVERE HAIL EARLY WEDNESDAY MORNING. ..EVANS/LEVIT.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 16:25:48 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 12:25:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041621 SWODY1 SPC AC 041619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CDT TUE APR 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL AND SOUTHERN CALIFORNIA... ...SYNOPSIS... WHILE DEEP UPPER LOW DEVELOPS OVER NEW ENGLAND...THE STRONG COLD LOW OFF CA COAST WILL BE MOVING INLAND TONIGHT. TRANSITORY RIDGE SURFACE AND ALOFT WILL SHIFT EWD ACROSS THE PLAINS ALLOWING GULF MOISTURE TO RETURN NORTHWARD THRU THE SRN/CENTRAL PLAINS. ...CA... THE COLD AND CONVECTIVELY ACTIVE UPPER LOW OFF CA COAST WILL MOVE INLAND TONIGHT. LAPSE RATES AROUND 7C/KM AND POTENTIAL MLCAPES TO AROUND 500 J/KG COUPLED WITH LARGE SCALE ASCENT AHEAD OF THE UPPER SYSTEM SUPPORT THE POTENTIAL OF A FEW SEVERE THUNDERSTORMS DEVELOPING THIS AFTERNOON FROM THE CENTRAL CA COAST INLAND ACROSS THE SAN JOAQUIN AND SRN SACRAMENTO VALLEYS. WHILE THE FLOW IS QUITE MERIDIONAL AHEAD OF THE UPPER SYSTEM...20KTS OF SFC-1KM SHEAR IN CONCERT WITH THE BACKED BOUNDARY LAYER FLOW WILL SUPPORT POTENTIAL FOR ORGANIZED LOW TOPPED THUNDERSTORMS. SUPERCELLS WOULD ALSO BE POSSIBLE PARTICULARLY NRN SAN JOAQUIN VALLEY WWD TO COAST PROVIDED THERE IS SUFFICIENT HEATING TO REALIZE THE POTENTIAL INSTABILITY. THUS IN ADDITION TO HAIL AND LOCALIZED STRONG DAMAGING WINDS...ISOLATED FUNNELS AND TORNADOES WOULD ALSO BE EXPECTED ALONG WITH WATERSPOUTS ALONG THE CENTRAL CA COAST. OVERNIGHT SHEAR PROFILES AND LAPSE RATES IMPROVE CONSIDERABLY SWD INTO THE LA BASIN AS 130KT UPPER JET MAX MOVES ONSHORE SRN CA AFTER 06Z. WHILE MLCAPES WILL GENERALLY BE LESS THAN 300 J/KG...TERRAIN INDUCED BACKING WIND PROFILES AND STRONG ASCENT WITH PASSAGE OF VIGOROUS UPPER TROUGH...LOW TOPPED SUPERCELLS ARE CERTAINLY A POSSIBILITY. IN ADDITION TO BRIEF DAMAGING WINDS/HAIL...ISOLATED TORNADOES/WATERSPOUTS WOULD ALSO BE A POSSIBILITY AT LEAST AS FAR S AS ORANGE COUNTY. ...CENTRAL FL... WILL MAINTAIN A LOW PROBABILITY OF THUNDERSTORMS AHEAD OF THE FRONTAL ZONE MOVING SLOWLY SWD THRU CENTRAL FL. MOST MODEL GUIDANCE INDICATE THAT THE STRONG HEATING S OF FRONT ALONG WITH AVAILABLE MOISTURE WILL BE SUFFICIENT TO OVERCOME THE CURRENT CINH WITH A COUPLE OF STRONG/SEVERE STORMS BY MID AFTERNOON. WITH LAPSE RATES AROUND 7C/KM AND MLCAPES AHEAD OF FRONT TO 1500 J/KG ISOLATED LARGE HAIL/DOWNBURST WINDS ARE POSSIBLE WITH THESE STORMS UNTIL AROUND SUNSET. ...SRN KS/NRN OK INTO SWRN MO/WRN AR... WITH THE LOW LEVEL JET STRENGTHENING TONIGHT ACROSS SRN PLAINS...ELEVATED MOISTURE AND INSTABILITY WILL SPREAD NEWD TOWARD LOWER MO VALLEY. STEEP MID LEVEL LAPSE RATES COUPLED WITH RETURNING GULF MOISTURE LEAD TO POTENTIAL OF ELEVATED CAPES TO 750 J/KG. IN ADDITION FORECAST SOUNDINGS 40-50 KT OF CLOUD LAYER SHEAR WOULD LEAD TO MID LEVEL ROTATION IN THUNDERSTORMS THAT DEVELOP IN THE WARM ADVECTION REGIME. LARGE HAIL WOULD BE POSSIBLE ASSOCIATED WITH ANY OF THESE STORMS...WHICH WOULD MOST LIKELY OCCUR AFTER 06Z. ..HALES/TAYLOR.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 19:58:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 15:58:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041955 SWODY1 SPC AC 041953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT TUE APR 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN CA... ...SYNOPSIS... HIGHLY AMPLIFIED UPPER AIR PATTERN WILL CONTINUE TO FEATURE DEEP LOWS OVER ERN GREAT LAKES...AND MOVING INLAND CA COAST. SFC FRONTAL ZONE ASSOCIATED WITH NERN STATES LOW IS ANALYZED ACROSS N-CENTRAL FL...WWD OVER NRN GULF OF MEXICO...TO S-CENTRAL TX. THIS FRONT SHOULD DECELERATE OVER CENTRAL FL THIS AFTERNOON/EVENING...WHILE BECOMING MORE DIFFUSE AND RETURNING NWD ACROSS S-CENTRAL/SW TX. PACIFIC COLD FRONT IS EVIDENT IN VIS IMAGERY ATTM FROM AROUND 27N125W NEWD TO NEAR 32N121W...THEN NWD ACROSS COASTAL AREAS OF SAN LUIS OBISPO COUNTY. THIS FRONT SHOULD MOVE EWD ACROSS MOST OF CENTRAL/SRN CA THIS AFTERNOON...AND INTO NV/AZ OVERNIGHT. ...CA... SEVERE POTENTIAL IS EXPECTED TO INCREASE THROUGH LATE AFTERNOON OVER PORTIONS SAN JOAQUIN/SRN SAC VALLEYS...ALONG/AHEAD OF SFC COLD FRONT. BREAKS IN CLOUD COVER ARE ALLOWING DIABATIC HEATING TO WEAKEN CINH FURTHER...COMBINING WITH COOLING TEMPS ALOFT TO STEEPEN LOW-MIDDLE LEVEL LAPSE RATES. THOUGH FLOW ALOFT REMAINS QUITE MERIDIONAL...OROGRAPHICALLY FORCED BACKING OF SFC FLOW IN VALLEY WILL ENHANCE DEEP-LAYER VERTICAL SHEAR. THIS SUPPORTS MAINLY LINEAR MODES WITH ENHANCED STORM-RELATIVE INFLOW AT SFC. EMBEDDED/LOW-TOPPED SUPERCELLS AND BOW ECHOES ARE POSSIBLE. REF WW 149 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST DETAILS. SEVERE THREAT IS EXPECTED TO SHIFT SWD OVERNIGHT AS STRONG SHORTWAVE TROUGH MOVES TROUGH BASE OF LARGER SYNOPTIC SYSTEM...GREATLY ENHANCING GRADIENT FLOW ALOFT AND STRENGTHENING LOW-MIDDLE LEVEL SHEAR PROFILES. ALTHOUGH TIME OF DAY WILL NOT BE FAVORABLE INLAND WITH RESPECT TO ABSOLUTE SFC HEATING...SFC-BASED BUOYANCY ACTUALLY SHOULD INCREASE THIS EVENING AND MUCH OF TONIGHT OVER REGION CONTAINING COASTAL SRN CA -- LA BASIN...SBA AREA AND CHANNEL ISLANDS. THIS SHOULD OCCUR AMIDST STRONG DIFFERENTIAL THERMAL ADVECTION WITH HEIGHT...WHERE COOLING OCCURS AT A FASTER RATE ALOFT THAN IN BOUNDARY LAYER. FCST VERTICAL SHEAR PROFILES SUGGEST LOW-TOPPED SUPERCELLS OR SMALL BOWS WITH HAIL...STRONG/DAMAGING WIND AND SOME TORNADO POTENTIAL. ...CENTRAL FL... AIRMASS CONTINUES TO DESTABILIZE ACROSS PORTIONS CENTRAL FL...WHERE SFC HEATING ALREADY HAS BOOSTED MLCAPES INTO 1500-2000 J/KG RANGE. VIS IMAGERY SHOWS TCU OVER MUCH OF CENTRAL FL INVOF FRONTAL ZONE...AND ALONG E COAST SEA BREEZE FRONT. ALTHOUGH STRONGEST MIDLEVEL FLOW WILL REMAIN N OF AREA...EFFECTIVE SHEARS 35-45 KT INVOF FRONT AND SEA BREEZE BOUNDARY INDICATE POTENTIAL FOR SOME TSTMS TO BECOME ORGANIZED WITH ISOLATED HAIL AND STRONG/DAMAGING GUSTS POSSIBLE. REF SPC MESOSCALE DISCUSSION 427 FOR MORE DETAILS ON NEAR-TERM THREAT. ACTIVITY SHOULD WEAKEN BY EARLY EVENING WITH LOSS OF SFC HEATING. ...E-CENTRAL PLAINS...WRN OZARKS... WIDELY SCATTERED TSTMS IN CLUSTERS ARE EXPECTED OVERNIGHT -- PRIMARILY AFTER 5/06Z...AS ELEVATED MOIST ADVECTION AND ISENTROPIC ASCENT RESULT IN PARCELS REACHING LFC. EXPECT FAVORABLE SHEAR FOR ORGANIZED ACTIVITY THROUGH DEPTH OF CONVECTIVE COLUMN...WITH ELEVATED MUCAPES INCREASING TO AROUND 400-700 J/KG. ISOLATED HAIL NEAR SEVERE LEVELS MAY OCCUR FROM MOST VIGOROUS CELLS. ..EDWARDS.. 04/04/2006  From SwoDy1 at goshenarc.org Wed Apr 5 00:53:02 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 20:53:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050050 SWODY1 SPC AC 050049 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 PM CDT TUE APR 04 2006 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CA... ...CA/GREAT BASIN... LARGE SCALE UPPER DIFFLUENCE HAS DEVELOPED AHEAD OF UPPER TROUGH INTO THE GREAT BASIN AS UPPER SPEED MAX APPROACHES SRN CA/NRN BAJA PENINSULA. THIS HAS AIDED WIDESPREAD CLOUDINESS AND PRECIPITATION ACROSS MUCH OF NRN/CNTRL CA...NEWD INTO NV WHERE BOUNDARY LAYER HEATING IS STRONGER AND DEEP CONVECTION IS SOMEWHAT MORE SCATTERED. GREATEST CONCENTRATION OF THUNDERSTORMS OVER THE NEXT FEW HOURS MAY ACTUALLY BE INLAND FROM CNTRL NV INTO SCNTRL ID...ESPECIALLY GIVEN THE PARTIAL SUNSHINE THAT PERSISTS ACROSS THIS REGION. SAN JOAQUIN VALLEY WILL HOWEVER REMAIN FAVORABLE FOR RENEWED THUNDERSTORM DEVELOPMENT AS UPPER TROUGH MOVES TOWARD THE COAST. EXIT REGION OF STRONG SPEED MAX WILL AID ASCENT ACROSS THIS REGION WHERE SHEAR PROFILES REMAIN SUPPORTIVE OF ROTATING UPDRAFTS. THE MAIN IMPEDIMENT FOR WIDESPREAD ROBUST CONVECTION IS THE ABSENCE OF SIGNIFICANT INSTABILITY. EVEN SO STRENGTH OF UPPER TROUGH CERTAINLY SUPPORTS THE POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WELL INTO THE EVENING HOURS...WITH LARGE HAIL THE MOST LIKELY SEVERE THREAT. ...SRN PLAINS... SWLY TRAJECTORIES ACROSS WEST TX INTO THE SRN PLAINS IS SERVING TO MOISTEN THE 750-800MB LAYER ACROSS CNTRL OK THIS EVENING. 00Z SOUNDING FROM OUN SUGGESTS CONVECTIVE POTENTIAL MAY NOT BE THAT MANY HOURS OFF AS WARM ADVECTION INCREASES OVER THE NEXT 3-6 HOURS. ELEVATED INSTABILITY SHOULD PROVE TOO WEAK TO WARRANT ANY MEANINGFUL THREAT OF LARGE HAIL. ..DARROW.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 05:52:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 01:52:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050549 SWODY1 SPC AC 050547 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1247 AM CDT WED APR 05 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL PLAINS... ...SOUTH DAKOTA/NEBRASKA... STRONG HEIGHT FALLS WILL SPREAD ACROSS THE CNTRL/SRN ROCKIES WEDNESDAY...APPROACHING 150M IN 12HR...BEFORE UPPER LOW EJECTS INTO ERN CO BY THE END OF THE PERIOD. THIS FEATURE WILL FORCE UPPER RIDGE INTO THE MS VALLEY REGION AND ASSOCIATED ISENTROPIC ELEVATED CONVECTIVE POTENTIAL INTO PORTIONS OF MO AND AR. WELL NW OF THIS ACTIVITY...CONVECTION SHOULD DEVELOP AHEAD OF STRONG DYNAMIC FRONT FROM WY...ARCING SWD INTO NWRN AZ. THIS ACTIVITY SHOULD SPREAD NEWD WITHIN STEEP LAPSE RATE ENVIRONMENT TOWARD THE CENTRAL HIGH PLAINS WHERE STRENGTHENING LOW LEVEL WARM ADVECTION AND A RECOVERING/MOISTENING BOUNDARY LAYER WILL ENHANCE CONVECTION AFTER DARK. LATEST THINKING IS UPPER RIDGE AND ASSOCIATED CAP WILL PREVENT THUNDERSTORM DEVELOPMENT ACROSS THE CNTRL HIGH PLAINS DURING THE AFTERNOON HOURS. HOWEVER...LATE IN THE AFTERNOON THUNDERSTORMS WILL EJECT NEWD ACROSS WY INTO WRN SD/NEB PANHANDLE WHERE SHEAR/THERMODYNAMIC PROFILES WILL BECOME MORE SUPPORTIVE OF ORGANIZED UPDRAFTS. ACTIVITY SHOULD QUICKLY BECOME ELEVATED BUT OBTAIN SUFFICIENT STRENGTH WITHIN MODEST CAPE ENVIRONMENT FOR HAIL PRODUCTION AND POSSIBLY A FEW GUSTY WIND REPORTS. ADDITIONAL ACTIVITY MAY DEVELOP DURING THE OVERNIGHT HOURS AS EXIT REGION OF UPPER JET SHIFTS EAST INTO THE HIGH PLAINS. ...WEST TX... DRY LINE WILL BECOME A BIT MORE FOCUSED AS IT MIXES EAST ACROSS WEST TX LATER THIS AFTERNOON. IT APPEARS STRONG HEATING WILL ALLOW SFC TEMPERATURES TO WARM TO NEAR 90 F WHICH WILL CREATE NEAR DRY ADIABATIC LAPSE RATES ALONG WRN EDGE OF INCREASINGLY MOIST BOUNDARY LAYER. ISOLATED THUNDERSTORMS COULD DEVELOP ALONG DRY LINE SHORTLY AFTER PEAK HEATING. IF SO...GUSTY WINDS OR SOME HAIL MAY ACCOMPANY SHORT-LIVED THUNDERSTORMS. LOSS OF HEATING WILL RESULT IN QUICK DEMISE OF ANY UPDRAFTS. ..DARROW.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 12:44:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 08:44:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051242 SWODY1 SPC AC 051240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT WED APR 05 2006 VALID 051300Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SD AND NEB INTO FAR NWRN IA... ...NRN PLAINS... LOW LEVEL MOISTURE WILL CONTINUE INCREASING ACROSS THE CENTRAL PLAINS TODAY AND TONIGHT AS SLY LLJ INTENSIFIES AHEAD OF POTENT SYSTEM NOW MOVING ACROSS THE WRN U.S. H85 DEW POINTS ARE FORECAST TO INCREASE INTO THE 8C-12C RANGE WITH AXIS OF MAXIMUM VALUES EXTENDING FROM THE LOWER MO RIVER VALLEY NWWD INTO CENTRAL/WRN SD BY LATE TONIGHT. LOW PRESSURE FROM THE SURFACE THRU H85 WILL DEVELOP EWD INTO WRN NEB/WRN SD LATER TONIGHT...WITH INCREASING CONVERGENCE AND LARGE SCALE ASCENT UNDER STRONG UPPER DIFFLUENCE SUPPORTING WIDESPREAD ELEVATED THUNDERSTORMS BEGINNING LATE THIS EVENING. DIURNAL DEVELOPMENT WILL LIKELY OCCUR OVER THE ERN WY MOUNTAINS AND THE BLACK HILLS...WITH AN ISOLATED THREAT OF LARGE HAIL/DAMAGING WINDS EWD TOWARDS THE CENTRAL HIGH PLAINS. HOWEVER...PRIMARY SEVERE THREAT IS EXPECTED TO OVERSPREAD SD/NRN NEB AFTER DARK. FORECAST SOUNDINGS INDICATE MUCAPE FROM 1000-1500 J/KG WITH 40-45 KT EFFECTIVE SHEAR...SUGGESTING ELEVATED SUPERCELLS WITHIN BROADER MCS. LARGE HAIL WILL BE PRIMARY SEVERE THREAT...THOUGH ISOLATED DAMAGING WINDS MAY OCCUR. ...WEST TX... DRY LINE WILL BECOME BETTER DEFINED TODAY AS BOUNDARY LAYER MOISTURE DEEPENS AND OVERSPREADS MUCH OF THE CENTRAL TX/OK AND STRONG HEATING/MIXING OCCURS OVER FAR WEST TX. FORECAST HIGHS APPROACHING 90F OVER THE WEST TX PLAINS AND SURFACE CONVERGENCE MAY OVERCOME WHAT IS INITIALLY STRONG CAPPING LATER TODAY. OTHER ISOLATED STORMS MAY FORM OVER HIGHER TERRAIN OF SWRN TX/FAR SERN NM. 4KM WRF-NMM IS MOST AGGRESSIVE IN DEVELOPING DEEP MOIST CONVECTION OVER FAR SWRN TX INTO THE LOW ROLLING PLAINS...THOUGH 06Z NAM BRIEFLY CONVECTS OVER THIS SMALL AREA BETWEEN 00-03Z. SHOULD A STORM INITIATE...STRONG INSTABILITY...VERY STEEP LAPSE RATES AND 40-50 KT OF DEEP LAYER SHEAR WOULD SUPPORT STRONG/DAMAGING GUSTS AND LARGE HAIL FROM HIGH-BASED STORMS THROUGH A FEW HOURS AFTER SUNSET. POTENTIAL APPEARS TOO CONDITIONAL ATTM TO WARRANT MORE THAN LOW SEVERE PROBABILITIES. ..EVANS/LEVIT.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 16:16:00 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 12:16:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051614 SWODY1 SPC AC 051612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT WED APR 05 2006 VALID 051630Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN UT/WRN CO NWD ACROSS WY INTO SERN MT AND THEN EWD ACROSS PARTS OF NEB/SD... ...SYNOPSIS... STRONG/COLD UPPER SYSTEM CURRENTLY MOVING INLAND SWRN U.S. WILL BE OVER CENTRAL/SRN ROCKIES BY LATER TONIGHT. DEEPENING SURFACE LOW NWRN UT WITH A STRONG COLD FRONT EXTENDING SWD THRU CENTRAL AZ AT 15Z WILL FOCUS DEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS TODAY. LOW WILL CONTINUE DEEPENING NEWD INTO WRN WY THIS AFTERNOON AND EVENING WHILE A NEW LOW DEVELOPS LEE OF CENTRAL ROCKIES AND MOVES INTO WRN NEB LATER TONIGHT. THE STRONG COLD FRONT WILL DRIVE NEWD ACROSS WY/WRN CO INTO WRN NM THIS AFTERNOON EMERGING INTO HIGH PLAINS LATER TONIGHT. ...CENTRAL AND NRN ROCKIES... WHILE ACTUAL INSTABILITY WILL BE TYPICALLY WEAK DUE TO LIMITED SURFACE MOISTURE THIS AREA AHEAD OF STRONG COLD FRONT OTHER PARAMETERS EXPECTED TO BE SUFFICIENT TO SUPPORT A THREAT OF SEVERE CONVECTIVE WINDS TO UPGRADE THIS AREA TO A SLIGHT RISK. THE COMBINATION OF NEAR ADIABATIC LAPSE RATES ...EXIT REGION OF A VERY STRONG UPPER JET MAX MOVING INTO 4-CORNERS AREA THIS AFTERNOON AND INTENSE FRONTAL LIFT WILL GENERATE THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT THIS AFTERNOON AS IT MOVES INTO WRN WY/CO. COMBINATION OF STRONG WINDS ALOFT AND CONVECTIVE CONTRIBUTION EXPECTED TO GENERATE POTENTIAL DAMAGING WINDS. THIS ACTIVITY WILL MOVE NEWD ACROSS THE CONTINENTAL DIVIDE BY THIS EVENING PRIOR TO SOME WEAKENING LEE SLOPES. FURTHER N INTO SERN MT...INCREASING ELY/SELY LOW LEVEL FLOW AND A LITTLE GREATER MOISTURE AHEAD OF DEEPENING SURFACE LOW AND FRONT...MLCAPES COULD CLIMB TO NEAR 1000 J/KG. VEERING HODOGRAPHS INCREASE POTENTIAL OF ROTATING STORMS DEVELOPING N AND E OF BIG HORNS WITH PRIMARY THREAT OF LARGE HAIL. WIND THREAT WOULD INCREASE INTO THIS AREA DURING THE EVENING AS THE STRONG FRONT APPROACHES FROM THE SW. ...NRN AND CENTRAL PLAINS... GULF MOISTURE CONTINUES TO FEED RAPIDLY NWD THRU THE FORECAST PERIOD WITH SUFFICIENT CINH TO LIMIT THREAT OF CONVECTIVE INITIATION UNTIL AFTER 00Z. WARM ADVECTION AND UPWARD MOTION AS THE STRONG DIFFLUENT JET MOVES INTO THE CENTRAL HIGH PLAINS LATER TONIGHT SHOULD AID IN DEVELOPMENT OF PRIMARILY ELEVATED THUNDERSTORMS EWD ACROSS SD/NEB. WITH ELEVATED CAPES IN EXCESS OF 2000 J/KG AND STEEP MID LEVEL LAPSE RATES SUPERCELLS ARE POSSIBLE. THIS WILL ENHANCE PRIMARILY LARGE HAIL THREAT OVERNIGHT. ...SWRN TX... STRONG SURFACE HEATING WILL WEAKEN CAP ON WESTERN EDGE OF MOISTURE LATER THIS AFTERNOON. A FEW THUNDERSTORMS ARE LIKELY TO DEVELOP OFF HIGHER TERRAIN OF SWRN TX. WITH DEEP LAYER SHEAR OF 40-50 KT AND STEEP LAPSE RATES ANY STORM THAT CAN DEVELOP WOULD BE POTENTIALLY SEVERE WITH PRIMARILY A LARGE HAIL POTENTIAL. THIS THREAT COULD CONTINUE AFTER DARK AS LOW LEVEL JET INCREASES TO 30-40 KTS ACROSS WRN TX. ..HALES/TAYLOR.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 19:40:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 15:40:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051937 SWODY1 SPC AC 051935 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0235 PM CDT WED APR 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL AND NRN ROCKIES INTO PARTS OF NEB AND SD... ...CNTRL AND NRN ROCKIES MOUNTAIN AREA... SCATTERED STORMS SHOULD CONTINUE DEVELOPING OVER THE CNTRL ROCKIES AREA THIS AFTERNOON AND SUBSEQUENTLY SPREAD NWD WITHIN ZONE OF ASCENT ASSOCIATED WITH NEWD MOVING VORT MAX. SURFACE DEWPOINTS ARE ONLY IN THE 30S...BUT COLD MID LEVEL TEMPERATURES AND SURFACE HEATING ARE CONTRIBUTING TO MARGINAL INSTABILITY. TEMPERATURES HAVE WARMED INTO THE 60S AND 70S RESULTING IN LARGE TEMPERATURE DEWPOINT SPREADS AND DRY BOUNDARY LAYERS. THIS WILL ENHANCE THE POTENTIAL FOR ISOLATED SEVERE WIND GUSTS WITH THE STRONGER STORMS...ESPECIALLY IF STORMS CAN BECOME ORGANIZED AS LINE SEGMENTS ALONG THE EWD ADVANCING FRONTAL ZONE EXTENDING THROUGH ERN UT. STRONG VERTICAL SHEAR PROFILES MAY ALSO CONTRIBUTE TO ROTATION IN SOME STORMS. THIS AND STEEP MID LEVEL LAPSE RATES SUGGEST A FEW STORMS COULD PRODUCE HAIL. ...NRN PLAINS... WARM FRONT WILL BECOME BETTER DEFINED OVER THE CNTRL PLAINS TONIGHT AS LEE CYCLONE DEEPENS. THE STRENGTHENING LOW LEVEL JET WILL ADVECT PARTIALLY MODIFIED GULF AIR NWD UNDERNEATH STEEP MID LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE MUCAPE. WARM ADVECTION AND LIFT ASSOCIATED WITH THE LOW LEVEL JET WILL CONTRIBUTE TO THE POTENTIAL FOR ELEVATED STORMS...PRIMARILY N OF THE WARM FRONT. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL WITH THE STRONGER STORMS. ...SRN CA... SCATTERED CONVECTION IS DEVELOPING WITHIN ZONE OF ASCENT AND COLD MID LEVEL TEMPERATURES ACCOMPANYING VORT MAX ROUNDING BASE OF UPPER TROUGH. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES SUGGEST ISOLATED STORMS MAY BE CAPABLE OF PRODUCING HAIL NEXT FEW HOURS. ...WRN AND SWRN TX... STRONG SURFACE HEATING AND MIXING ON WRN EDGE OF THE RICHER LOW LEVEL MOISTURE MAY WEAKEN CAP SUFFICIENTLY FOR ISOLATED HIGH BASED STORMS TO DEVELOP OVER PORTIONS OF WRN AND SWRN TX. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION MAY CONTRIBUTE TO A THREAT FOR HAIL. HIGH BASED NATURE OF THE STORMS SUGGESTS ISOLATED STRONG WIND GUSTS MAY ALSO BE POSSIBLE THROUGH EARLY EVENING. COVERAGE IS NOT EXPECTED TO BE SUFFICIENT TO WARRANT A SLIGHT RISK. ..DIAL.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 20:15:13 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 16:15:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 052011 SWODY1 SPC AC 052010 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0310 PM CDT WED APR 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL AND NRN ROCKIES INTO PARTS OF NEB AND SD... ...CNTRL AND NRN ROCKIES MOUNTAIN AREA... SCATTERED STORMS SHOULD CONTINUE DEVELOPING OVER THE CNTRL ROCKIES AREA THIS AFTERNOON AND SUBSEQUENTLY SPREAD NWD WITHIN ZONE OF ASCENT ASSOCIATED WITH NEWD MOVING VORT MAX. SURFACE DEWPOINTS ARE ONLY IN THE 30S...BUT COLD MID LEVEL TEMPERATURES AND SURFACE HEATING ARE CONTRIBUTING TO MARGINAL INSTABILITY. TEMPERATURES HAVE WARMED INTO THE 60S AND 70S RESULTING IN LARGE TEMPERATURE DEWPOINT SPREADS AND DRY BOUNDARY LAYERS. THIS WILL ENHANCE THE POTENTIAL FOR ISOLATED SEVERE WIND GUSTS WITH THE STRONGER STORMS...ESPECIALLY IF STORMS CAN BECOME ORGANIZED AS LINE SEGMENTS ALONG THE EWD ADVANCING FRONTAL ZONE EXTENDING THROUGH ERN UT. STRONG VERTICAL SHEAR PROFILES MAY ALSO CONTRIBUTE TO ROTATION IN SOME STORMS. THIS AND STEEP MID LEVEL LAPSE RATES SUGGEST A FEW STORMS COULD PRODUCE HAIL. ...NRN PLAINS... WARM FRONT WILL BECOME BETTER DEFINED OVER THE CNTRL PLAINS TONIGHT AS LEE CYCLONE DEEPENS. THE STRENGTHENING LOW LEVEL JET WILL ADVECT PARTIALLY MODIFIED GULF AIR NWD UNDERNEATH STEEP MID LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE MUCAPE. WARM ADVECTION AND LIFT ASSOCIATED WITH THE LOW LEVEL JET WILL CONTRIBUTE TO THE POTENTIAL FOR ELEVATED STORMS...PRIMARILY N OF THE WARM FRONT. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL WITH THE STRONGER STORMS. ...SRN CA... SCATTERED CONVECTION IS DEVELOPING WITHIN ZONE OF ASCENT AND COLD MID LEVEL TEMPERATURES ACCOMPANYING VORT MAX ROUNDING BASE OF UPPER TROUGH. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES SUGGEST ISOLATED STORMS MAY BE CAPABLE OF PRODUCING HAIL NEXT FEW HOURS. ...WRN AND SWRN TX... STRONG SURFACE HEATING AND MIXING ON WRN EDGE OF THE RICHER LOW LEVEL MOISTURE MAY WEAKEN CAP SUFFICIENTLY FOR ISOLATED HIGH BASED STORMS TO DEVELOP OVER PORTIONS OF WRN AND SWRN TX. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION MAY CONTRIBUTE TO A THREAT FOR HAIL. HIGH BASED NATURE OF THE STORMS SUGGESTS ISOLATED STRONG WIND GUSTS MAY ALSO BE POSSIBLE THROUGH EARLY EVENING. COVERAGE IS NOT EXPECTED TO BE SUFFICIENT TO WARRANT A SLIGHT RISK. ..DIAL.. 04/05/2006  From SwoDy1 at goshenarc.org Thu Apr 6 01:04:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 21:04:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060102 SWODY1 SPC AC 060100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT WED APR 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM PARTS OF THE NRN HIGH PLAINS INTO THE MID/LOWER MISSOURI VALLEY.... CLOSED LOW EMBEDDED WITHIN LARGE-SCALE WESTERN U.S. UPPER TROUGH CURRENTLY APPEARS CENTERED OVER THE NORTH CENTRAL GREAT BASIN... WITH INITIAL IMPULSE ROTATING AROUND ITS SOUTHERN/EASTERN PERIPHERY...INTO THE NORTH CENTRAL ROCKIES. FORCING WITH THIS FEATURE HAS CONTRIBUTED TO THE DEVELOPMENT OF A DEEP SURFACE LOW...WHICH HAS SHIFTED ACROSS NORTH CENTRAL WYOMING INTO SOUTH CENTRAL/SOUTHEASTERN MONTANA. HOWEVER...IT STILL APPEARS THAT PRIMARY SURFACE LOW WILL EVENTUALLY FORM ACROSS NORTHEAST COLORADO INTO WESTERN NEBRASKA OVERNIGHT. THIS IS PROGGED TO OCCUR AS A MORE SIGNIFICANT IMPULSE ACCELERATES EASTWARD OUT OF THE LOWER COLORADO VALLEY. STRONG MID-LEVEL COOLING WILL ACCOMPANY THIS FEATURE INTO THE SOUTH CENTRAL ROCKIES LATE TONIGHT...AND MID-LEVEL CLOSED LOW WILL BEGIN TO REDEVELOP SOUTHEASTWARD INTO THE CENTRAL ROCKIES/HIGH PLAINS BY 12Z THURSDAY...OR SHORTLY THEREAFTER. ...SOUTHEAST MONTANA... DESPITE VERY LIMITED LOW-LEVEL MOISTURE...STEEP LOW/MID-LEVEL LAPSE RATES HAVE DEVELOPED IN WARM SECTOR OF DEEP SURFACE LOW. CAPE MAY BE WEAK...BUT THERMODYNAMIC PROFILES WITH A DEEPLY MIXED BOUNDARY LAYER WILL BE SUPPORTIVE OF PRIMARILY DAMAGING WIND GUSTS THROUGH EARLY EVENING. SHEAR PROFILES ARE SUFFICIENT FOR UPDRAFT ROTATION...AND AN ISOLATED SUPERCELL MAY STILL DEVELOP BEFORE NIGHTFALL BETWEEN BILLINGS AND MILES CITY...WHICH WOULD ENHANCE RISK FOR STRONG WIND GUSTS/HAIL...PERHAPS A BRIEF TORNADO. ...MID/LOWER MISSOURI VALLEY... SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT IS ALREADY UNDERWAY ACROSS PARTS OF THE LOWER MISSOURI VALLEY...WHERE SOUTHERLY LOW-LEVEL JET IS ENHANCING WARM ADVECTION...NORTH OF CAPPING MID-LEVEL RIDGE. ACTIVITY IS BASED IN ELEVATED MOIST LAYER WITH MOST UNSTABLE CAPE INCREASING AS HIGH AS 1500 J/KG...WHICH WILL SUPPORT AT LEAST MARGINALLY SEVERE HAIL IN FAVORABLY SHEARED ENVIRONMENT. COVERAGE OF STORMS SHOULD CONTINUE TO INCREASE OVERNIGHT. ...WESTERN SOUTH DAKOTA/NORTHERN NEBRASKA... EXIT REGION OF STRONG MID-LEVEL JET MAY BEGIN TO OVERSPREAD WARM FRONTAL ZONE TOWARD 09-12Z. THIS SHOULD WEAKEN INHIBITION ALONG BOUNDARY...WHICH WILL BECOME FOCUS FOR THUNDERSTORM ACTIVITY. CAPE FOR MOIST PARCELS BASED ABOVE FRONTAL INVERSION IS EXPECTED UP TO AROUND 1500 J/KG...WHICH WILL CONTRIBUTE TO RISK FOR SEVERE STORMS...MAINLY WITH LARGE HAIL. ..KERR.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 06:04:36 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 02:04:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060601 SWODY1 SPC AC 060600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT THU APR 06 2006 VALID 061200Z - 071200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTN AND EARLY EVE ACROSS PARTS OF ERN NEB/ERN KS/PARTS OF ERN OK/WRN IA/WRN MO AND NW AR...WHERE WIDESPREAD SEVERE THUNDERSTORMS APPEAR POSSIBLE...INCLUDING RISK FOR VERY LARGE HAIL/DAMAGING WINDS AND A FEW TORNADOES.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA ACROSS MUCH OF THE EAST CENTRAL PLAINS INTO MIDDLE MS VLY.... COLD SOUTHERN BRANCH TROUGH OVER THE INTERMOUNTAIN WEST IS OUT OF PHASE WITH THE NORTHERN STREAM...AND NEXT UPSTREAM IMPULSE IS PROGGED TO REMAIN WELL WEST OF THE PACIFIC COAST THROUGH AT LEAST 12Z FRIDAY. HOWEVER...THE SYSTEM IS SLOWLY PROGRESSING EASTWARD INTO THE ROCKIES...TO THE SOUTH OF A NORTHERN BRANCH RIDGE...WHICH WILL PERSIST TO THE LEE OF THE CANADIAN ROCKIES. THOUGH THERE IS SOME CONCERN ABOUT THE RATE OF PROGRESSION OF THE TROUGH TO THE EAST OF THE U.S. ROCKIES...MODELS CONTINUE TO INDICATE THAT EMBEDDED CIRCULATION WILL REFORM SOUTHEASTWARD INTO EASTERN COLORADO EARLY TODAY...THEN INTO THE CENTRAL PLAINS BY THE END OF THE FORECAST PERIOD. THIS IS PROGGED TO OCCUR AS A STRONG MID-LEVEL IMPULSE/JET STREAK ROTATES AROUND ITS SOUTHERN/EASTERN PERIPHERY...ACROSS THE CENTRAL PLAINS DURING THE DAY TODAY...THROUGH THE MID/LOWER MISSOURI VALLEY BY LATE TONIGHT. IN RESPONSE TO EVOLVING UPPER FLOW PATTERN...PRIMARY SURFACE CYCLONE IS PROGGED TO FORM OVER CENTRAL NEBRASKA...THEN SLOWLY DEEPEN THROUGH THE DAY. SYSTEM IS PROGGED TO BECOME OCCLUDED LATE THIS AFTERNOON AND TONIGHT...BUT REMAIN OVER THE NORTH CENTRAL PLAINS AS WEAK TRIPLE POINT WAVE SHIFTS EASTWARD TOWARD THE SOUTHERN GREAT LAKES REGION. ...CENTRAL STATES... CONSIDERABLE CLOUD COVER AND SCATTERED CONVECTIVE DEVELOPMENT SEEM LIKELY TO IMPEDE BOUNDARY LAYER DESTABILIZATION THROUGH MUCH OF THE OZARKS INTO THE MIDDLE MISSISSIPPI VALLEY TODAY. HOWEVER... MID-LEVEL DRY SLOT IS EXPECTED TO ALLOW INSOLATION IN AT LEAST A NARROW CORRIDOR AHEAD OF COLD FRONT/DRY LINE TRAILING SOUTHWARD FROM SURFACE LOW CENTER. BY MID DAY...BOUNDARY IS EXPECTED ROUGHLY WEST OF GRAND ISLAND NEB/MANHATTAN AND WICHITA KS INTO CENTRAL OKLAHOMA...PRECEDED BY TONGUE OF 60F+ SURFACE DEW POINTS. AS MID-LEVEL THERMAL TROUGH TAKES ON INCREASING NEGATIVE TILT...MID-LEVEL CAPPING IS EXPECTED TO BE BROKEN...PERHAPS AS EARLY AS THE 18-21Z TIME FRAME. RAPID DEVELOPMENT OF A BROKEN SQUALL LINE APPEARS LIKELY IN AN ENVIRONMENT WITH STEEP LAPSE RATES AND MODERATELY STRONG CAPE OF 1500-2000 J/KG...AND SHEAR IN EXIT REGION OF 90+ KT 500 MB JET NOSING ACROSS OKLAHOMA WILL BE SUFFICIENT FOR SUPERCELLS. VERY LARGE HAIL/DAMAGING WIND GUSTS WILL LIKELY ACCOMPANY STRONGEST CONVECTION. TORNADO POTENTIAL IS MORE UNCERTAIN...MAINLY ACROSS EASTERN KANSAS INTO WESTERN MISSOURI...WHERE DEEP LAYER SOUTHERLY FLOW WILL EXIST. FARTHER TO THE NORTH...TO THE EAST OF SURFACE LOW CENTER...EASTERLY LOW-LEVEL FLOW WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVING LOW-LEVEL HODOGRAPHS BENEATH MODERATE STRONG SOUTHERLY UPPER FLOW. THIS SHOULD ENHANCE POTENTIAL FOR TORNADOES ACROSS PARTS OF EASTERN NEBRASKA INTO WESTERN IOWA...PERHAPS EXTREME NORTHWEST MISSOURI. A SECONDARY AREA OF SIGNIFICANT CONVECTIVE DEVELOPMENT APPEARS POSSIBLE WHERE MID-LEVEL JET STREAK NOSES OVER DRY LINE ACROSS NORTHEAST OKLAHOMA. THIS SEEMS POSSIBLE BY 21-22Z. MODELS SUGGEST STRONG MID-LEVEL FLOW ACROSS THIS REGION WILL VEER TO A MORE WESTERLY COMPONENT...WHICH MAY FAVOR MORE DISCRETE SUPERCELL DEVELOPMENT IN ENVIRONMENT WITH CAPE AROUND 2000 J/KG. VEERING OF WINDS WITH HEIGHT BENEATH 30 TO 50 KT SOUTHERLY LOW-LEVEL JET MAY NOT BECOME STRONG...BUT SHEAR IS EXPECTED TO BE SUFFICIENT FOR TORNADIC ACTIVITY. ISOLATED STRONG TORNADOES SEEM POSSIBLE AS ACTIVITY DEVELOPS NORTHEASTWARD INTO THE OZARK PLATEAU. SEVERE THREAT MAY CONTINUE THROUGH THE EVENING INTO MUCH OF THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...INTENSITY/COVERAGE OF SEVERE THREAT IS EXPECTED TO DIMINISH SIGNIFICANTLY BY LATE EVENING...AS EVOLUTION OF LARGE-SCALE PATTERN DOES NOT APPEAR LIKELY TO SUPPORT SIGNIFICANT EASTWARD DESTABILIZATION DURING THIS FORECAST PERIOD. ..KERR/CROSBIE.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 12:36:40 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 08:36:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061234 SWODY1 SPC AC 061232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0732 AM CDT THU APR 06 2006 VALID 061300Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS OVER NERN KS INTO SERN NEB AND FAR NWRN MO LATER TODAY AND THIS EVENING... ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK FROM ERN NEB/WRN IA INTO WRN MO...ERN OK AND WRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK OVER PORTIONS OF THE SRN/CENTRAL PLAINS EWD ACROSS THE MID MS RIVER VALLEY... ...SIGNIFICANT SEVERE WEATHER OUTBREAK /INCLUDING NUMEROUS TORNADIC SUPERCELLS/ IS EXPECTED TO EVOLVE ACROSS EASTERN PORTIONS OF THE CENTRAL PLAINS STATES LATER TODAY AND THIS EVENING... ...SYNOPSIS... POTENT MID/UPPER LEVEL LOW NOW OVER THE FOUR-CORNERS REGION WILL RAPIDLY EJECT NEWD INTO THE CENTRAL PLAINS TODAY...WITH 210M HEIGHT FALLS AT H5 SPREADING ACROSS ERN KS BY 00Z. SIGNIFICANT MID TO UPPER LEVEL JET MAX WILL ACCOMPANY THIS SYSTEM WITH H5 WINDS IN EXCESS OF 100 KT /115+ KT AT H25/ SHIFTING ACROSS OK. ASSOCIATED SURFACE LOW NOW TAKING SHAPE OVER CENTRAL NEB WILL DEEPEN AS IT BECOMES BETTER DEFINED NEAR THE N-CENTRAL KS/SERN NEB BORDER LATER THIS AFTERNOON. AS THIS OCCURS...VERY STRONG DRY LINE WILL MIX TO NEAR THE I-35 CORRIDOR BY 18Z AND THEN SHIFT RAPIDLY EWD INTO WRN MO/WRN AR THIS EVENING. AHEAD OF THIS...MODEST LOW LEVEL MOISTURE WILL REMAIN IN PLACE WITH AXIS OF AROUND 60F SURFACE DEW POINTS EXTENDING INTO ERN KS AND FAR SERN NEB THIS AFTERNOON. IN ADDITION...VERY STEEP LAPSE RATES /I.E. 8.5+ C/KM FROM H7-H5/ ARE ALREADY OBSERVED ACROSS THE REGION AND WILL REMAIN IN PLACE TODAY. ...ERN SD/NEB INTO KS/MO/IA... MORNING CONVECTION WITH THREAT OF ISOLATED LARGE HAIL WILL LIKELY INCREASE WITHIN BROAD UPPER DIFFLUENCE ACROSS SD AND INTO PORTIONS OF IA THIS MORNING. IN ADDITION...WITH H85 FLOW REMAINING VEERED TO SWLY OVER THE SRN PLAINS...LOW LEVEL WAA AND ASCENT AHEAD OF SUBTLE DISTURBANCE EVIDENT ON WV IMAGERY MOVING INTO SWRN OK WILL LIKELY INCREASE CLOUDS AND MOIST CONVECTION ACROSS CENTRAL OK AND INTO THE OZARKS THIS MORNING. THIS ACTIVITY WILL ALSO LIKELY REMAIN ELEVATED ABOVE STRONGLY CAPPED BOUNDARY LAYER...THOUGH CLOUD LAYER SHEAR AND STEEP LAPSE RATES COULD SUPPORT LARGE HAIL. PRIMARY SEVERE THREAT IS STILL EXPECTED TO ERUPT ALONG THE DRY LINE ALONG LEADING EDGE OF STRONG ASCENT FROM CENTRAL NEB INTO N-CENTRAL OK...POSSIBLY AS EARLY AS 18Z...AND EVOLVE INTO AN OUTBREAK OF SEVERE THUNDERSTORMS THROUGH 02-03Z ACROSS MUCH OF ERN KS AND PORTIONS OF SERN NEB/WRN MO. WARM SECTOR IS FORECAST TO BECOME MODERATELY UNSTABLE WITH MLCAPE TO 2000 J/KG INTO THE CENTRAL PLAINS. VERY STRONG SHEAR REMAINS SUPPORTIVE OF SUPERCELLS...WITH A VARIETY OF STORM MOTIONS. CELLS INTO ERN NEB WILL TEND TO DEVELOP NWD AND ROTATE NWWD TOWARDS CENTRAL NEB...WHILE DEVELOPMENT SOUTH OF THE SURFACE LOW WILL TEND TO SHIFT RAPIDLY ENEWD ACROSS ERN KS AND INTO WRN MO WHERE AIR MASS WILL LIKELY DESTABILIZE IN WAKE OF ANY EARLY DAY ACTIVITY. SOUNDINGS CONTINUE TO SUPPORT VERY LARGE AND DAMAGING HAIL WITH SOME HAIL STONES EXCEEDING 3-4 INCHES IN DIAMETER. SUPERCELLS ARE ALSO EXPECTED TO BECOME TORNADIC...ESPECIALLY INTO NERN KS/FAR SERN NEB/NWRN MO WHERE STRONG PRESSURE FALLS AND BACKED SURFACE WINDS WILL ENHANCE LOW LEVEL HELICITIES AND LCLS REMAIN MORE FAVORABLE ESE OF THE LOW CENTER. CONVECTIVE MODE/STORM-SCALE EVOLUTION STILL HARD TO DETERMINE ATTM...AS SOME OF THE ACTIVITY MAY EVOLVE INTO LEWP/BOW ECHOES...ESPECIALLY INTO THE EVENING. REGARDLESS...SUPERCELL STRUCTURES ARE EXPECTED TO REMAIN WIDESPREAD WITH ATTENDANT THREAT OF TORNADOES...SOME OF WHICH COULD BE QUITE STRONG GIVEN MAGNITUDE OF SHEAR AND STRONG SURFACE PRESSURE FALLS. STORMS ARE EXPECTED TO EVENTUALLY OUTRUN INSTABILITY NEAR THE LOWER MO/MID-MS RIVER VALLEYS AND BECOME INCREASINGLY ELEVATED NORTH OF THE WARM FRONT LATER THIS EVENING/OVERNIGHT...THOUGH LARGE HAIL POTENTIAL MAY SPREAD ACROSS THE MID MS RIVER VALLEY AND INTO THE OH RIVER VALLEY LATE TONIGHT. ...ERN OK/WRN AR INTO FAR NERN TX... SIGNIFICANT MID/UPPER LEVEL SHEAR WILL DEVELOP ACROSS THE DRY LINE INTO ERN OK/NERN TX LATER TODAY...WHERE MLCAPES SHOULD APPROACH 2500 J/KG ALONG WRN EDGE OF MID LEVEL CLOUD SHIELD NOW EXTENDING NE-SW ACROSS CENTRAL OK. CAPPING WILL BE MORE PROBLEMATIC SOUTH OF UPPER JET AND WITHIN WEAKER ASCENT THAN COMPARED TO AREAS FARTHER NORTH. HOWEVER...FORECAST SOUNDINGS CONTINUE TO INDICATE DANGEROUS COMBINATION OF LONG HODOGRAPHS AND MODERATE INSTABILITY. STORMS MAY REMAIN MORE ISOLATED ACROSS THIS REGION...THOUGH PARAMETERS REMAIN QUITE FAVORABLE FOR LONG-LIVED SUPERCELLS... INCLUDING STRONG AND DAMAGING TORNADOES...WITH STORMS THAT DO DEVELOP. THIS ACTIVITY WILL LIKELY BECOME ELEVATED DURING THE MID/LATE EVENING INTO CENTRAL AR AND SPREAD ISOLATED DAMAGING WIND/LARGE HAIL THREAT TOWARDS THE LOWER OH RIVER VALLEY LATER TONIGHT. ..EVANS/CROSBIE.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 16:31:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 12:31:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061624 SWODY1 SPC AC 061623 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 AM CDT THU APR 06 2006 VALID 061630Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR S/SE NEB...ROUGHLY THE ERN HALF OF KS...AND A SMALL PART OF WRN MO.... ...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM ERN NEB/WRN IA SWD TO ERN OK AND WRN AR.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT AND HIGH RISK AREAS...FOR MUCH OF THE CENTRAL PLAINS TO THE MID MS VALLEY.... ...SIGNIFICANT SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON/EVENING FROM SE NEB ACROSS ERN KS/WRN MO INTO ERN OK AND WRN AR... ...CENTRAL PLAINS THIS AFTERNOON INTO MO/AR TONIGHT... WITHIN A BROAD MID LEVEL LOW OVER THE CENTRAL ROCKIES...AN INTENSE MID LEVEL SHORTWAVE TROUGH IS ROTATING EWD FROM NM TOWARD OK/KS THIS AFTERNOON. A SURFACE CYCLONE NOW IN E CENTRAL NEB WILL PERSIST TODAY...WITH ADDITIONAL CYCLOGENESIS EXPECTED INVOF SW INTO CENTRAL KS IN RESPONSE TO 210 M HEIGHT FALLS AT 500 MB DURING THE AFTERNOON. THIS KS LOW SHOULD THEN ROTATE NNEWD TOWARD NEB THIS EVENING AND EVOLVE INTO A DEEP OCCLUDED SYSTEM OVERNIGHT. LOW-LEVEL MOISTURE CONTINUES TO SPREAD NWD FROM TX/LA/AR/OK NWD TO WRN MO...KS/NEB. REGIONAL 12Z SOUNDINGS REVEALED A PRONOUNCED EML ABOVE THE MOIST LAYER...WITH MEAN BOUNDARY LAYER DEWPOINTS IN THE UPPER 50S TO LOWER 60S. GIVEN THE SHALLOW BOUNDARY LAYER OBSERVED ACROSS S TX...AFTERNOON DEWPOINTS SHOULD GENERALLY REMAIN IN THE 60-62 F RANGE WITHIN THE WARM SECTOR...AS OPPOSED TO RECENT NAM FORECASTS OF MID 60S. VERY STEEP MID LEVEL LAPSE RATES...ALONG WITH AN EROSION OF THE CAP FROM BELOW BY HEATING AND FROM THE W BY ASCENT WITH THE APPROACHING WAVE...WILL SUPPORT AN INCREASING THREAT FOR CONVECTIVE INITIATION BY 18-20Z NEAR THE PACIFIC COLD FRONT AND DEVELOPING SECONDARY LOW INVOF CENTRAL KS. STORMS SHOULD EXPAND IN COVERAGE THROUGH THE AFTERNOON INTO S CENTRAL/SE NEB AND ERN KS...WITH ADDITIONAL DEVELOPMENT POSSIBLE SWD ALONG THE PACIFIC COLD FRONT IN OK TO THE E OF I-35 BY MID-LATE AFTERNOON. WITH DAYTIME HEATING...MODERATE TO STRONG INSTABILITY IS EXPECTED WITHIN THE INITIAL MID LEVEL DRY SLOT WHERE MLCAPE VALUES SHOULD REACH 1500-2000 J/KG. THE FORECAST ORIENTATION OF THE MID-UPPER FLOW RELATIVE TO THE INITIATING SURFACE BOUNDARIES...ALONG WITH THE STRONG FORCING WITH THE APPROACHING WAVE...SUGGEST THE POSSIBILITY OF MIXED MODE CONVECTION WITH BOTH SUPERCELLS AND BOWING LINE SEGMENTS ACROSS KS/NEB. AFTERNOON TEMPERATURE- DEWPOINT SPREADS MAY BE MARGINALLY LARGE FOR SIGNIFICANT TORNADOES...THOUGH FORECAST HODOGRAPHS STILL APPEAR SUPPORTIVE OF TORNADOES. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY WITH THESE STORMS. FARTHER S AND LATER THIS AFTERNOON/EVENING...PROFILES APPEAR SUPPORTIVE OF DISCRETE SUPERCELLS ACROSS ERN OK/AR/SRN MO INTO EARLY TONIGHT. TORNADOES WILL BE POSSIBLE WITH THESE STORMS...A FEW OF WHICH COULD BE STRONG...GIVEN AN INCREASE IN LOW-LEVEL SHEAR THIS EVENING AND A MORE MOIST ENVIRONMENT COMPARED TO AREAS FARTHER W AND N. ...MS AND MO VALLEYS TODAY... ELEVATED CONVECTION CONTINUES TO DEVELOP IN A SWATH FROM ERN SD TO SE IA INTO MO/IL IN A REGION OF PRONOUNCED WAA. STEEP MID LEVEL LAPSE RATES AND LIMITED ELEVATED CAPE WILL SUPPORT A THREAT FOR ISOLATED LARGE HAIL WITH THIS CONVECTION THROUGH THE AFTERNOON. FARTHER S...OTHER ELEVATED STORMS ARE FORMING ACROSS ERN OK/WRN AR INTO NE TX. LARGE HAIL WILL ALSO BE THE PRIMARY THREAT WITH THIS ACTIVITY...THOUGH DAMAGING WINDS COULD BECOME POSSIBLE AS THE BOUNDARY LAYER GRADUALLY DESTABILIZES. ..THOMPSON/TAYLOR.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 20:15:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 16:15:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062011 SWODY1 SPC AC 062009 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0309 PM CDT THU APR 06 2006 VALID 062000Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF FAR SE NEB...ERN KS...ERN OK...WRN MO AND WRN AR... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SW IA...ERN NEB...KS...ERN OK...WRN MO AND AR... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE PLAINS AND MS RIVER VALLEY... ...CNTRL AND SRN PLAINS/OZARKS... WATER VAPOR IMAGERY CURRENTLY SHOWS A VIGOROUS UPPER-LOW/TROUGH OVER THE HIGH PLAINS WITH A DRY SLOT ADVANCING EWD ACROSS ERN KS AND CNTRL OK. A 90 KT MID-LEVEL JET IS CURRENTLY EJECTING NEWD OUT OF THE BASE OF THE TROUGH SPREADING STRONG DIVERGENCE ACROSS THE CNTRL AND SRN PLAINS. THE STRONG LIFT COMBINED WITH AN AXIS OF MODERATE INSTABILITY AND WEAKENING CAP IS RESULTING IN RAPID STORM INITIATION FROM CNTRL KS EXTENDING SSEWD ACROSS ECNTRL OK. REGIONAL PROFILERS CURRENTLY SHOW STRONG VERTICAL SHEAR PROFILES WHICH ARE BEING ENHANCED BY THE EJECTING MID-LEVEL JET. IN ADDITION...MID-LEVEL LAPSE RATES ARE STEEPENING AS THE TROUGH APPROACHES FROM THE WEST. AS A RESULT...THE ENVIRONMENT APPEARS VERY FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. VERY LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS. AS THE STORMS TRACK NEWD INTO INCREASING LOW-LEVEL FLOW AND GREATER INSTABILITY...THE TORNADO THREAT WILL INCREASE. THE BEST POTENTIAL FOR STRONG TORNADOES APPEARS TO EXIST OVER NE OK...NW AR...ERN KS AND FAR WRN MO WHERE THE LOW-LEVEL SHEAR PROFILES ARE BEING ENHANCED BY A STRONG LOW-LEVEL JET. AS THE TROUGH PASSES BY LATE THIS EVENING...STORMS SHOULD ALSO DEVELOP IN FAR NE TX...SE OK AND SW AR BUT STORM COVERAGE SHOULD BE LESS DUE TO WEAKER LARGE-SCALE ASCENT IN THAT AREA. AS THE DRY SLOT SHIFTS EWD ACROSS THE REGION...STORMS WILL GRADUALLY MOVE EWD ACROSS MO AND AR. ALTHOUGH THE SEVERE THREAT SHOULD CONTINUE THROUGH MUCH OF THE NIGHT DUE TO THE VERY STRONG VERTICAL SHEAR AND FOCUSED LARGE-SCALE ASCENT...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL BY LATE TONIGHT. ...NRN AND CNTRL PLAINS/UPPER MIDWEST... STORMS ARE CURRENTLY INITIATING ACROSS FAR NRN KS ALONG THE LEADING EDGE OF ASCENT AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH. ADDITIONAL STORMS WILL INITIATE ACROSS SRN NEB WITH STORM COVERAGE INCREASING LATE THIS AFTERNOON. SFC ANALYSIS CURRENTLY SHOWS SFC DEWPOINTS IN THE 50S F ACROSS NE KS...ERN NEB AND WRN IA WITH MODERATE INSTABILITY EXTENDING AS FAR NORTH AS SERN SD. AS THE TROUGH APPROACHES LATE THIS AFTERNOON...VERTICAL SHEAR WILL CONTINUE TO INCREASE AND LAPSE RATES WILL STEEPEN FURTHER WHICH COMBINED WITH THE INSTABILITY WILL BE VERY FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. WIND DAMAGE WILL ALSO BE LIKELY WITH THE STRONGER SUPERCELLS AND SHOULD BE ENHANCED SOMEWHAT BY THE LARGE SFC TEMP-DEWPOINT SPREADS EXCEEDING 30 DEGREES F IN SOME PLACES. A FEW TORNADOES WILL ALSO BE POSSIBLE AS THE STORMS BECOME AFFECTED BY A STRENGTHENING LOW-LEVEL JET EARLY THIS EVENING. THE MODELS DEVELOP A LARGE MCS THIS EVENING ACROSS SD...ERN NEB...SRN MN AND IA WHICH SEEMS REASONABLE CONSIDERING THE AMOUNT OF LARGE-SCALE ASCENT MOVING EWD AHEAD OF THE TROUGH. THE STORMS SHOULD MOVE AND DEVELOP NEWD INTO THE UPPER MIDWEST AFTER MIDNIGHT BUT THE SEVERE THREAT SHOULD GRADUALLY BECOME MARGINAL DUE TO WEAKENING INSTABILITY. ..BROYLES.. 04/06/2006  From SwoDy1 at goshenarc.org Fri Apr 7 00:53:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 20:53:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070050 SWODY1 SPC AC 070048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT THU APR 06 2006 VALID 070100Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS EARLY THIS EVE ACROSS PARTS OF SE KS/NE OK/NW AR...AND SW MO.... ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA ACROSS MUCH OF THE OZARK PLATEAU.... ...THERE IS A MDT RISK OF SVR TSTMS EARLY THIS EVENING ACROSS PARTS OF EXTREME SE SD/ERN NEB AND WRN IA.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT AND HIGH RISK AREAS ACROSS A LARGE PART OF THE E CNTRL PLAINS INTO THE MID MO VALLEY.... MID-LEVEL CIRCULATION HAS DEVELOPED INTO THE CENTRAL HIGH PLAINS... BUT WILL REDEVELOP EASTWARD TOWARD THE MID/LOWER MISSOURI VALLEY... AS STRONG IMPULSE CONTINUES TO PIVOT AROUND ITS SOUTHEASTERN INTO EASTERN PERIPHERY. STRONGEST MID-LEVEL COOLING OVERNIGHT WILL SURGE NORTHEASTWARD FROM THE SOUTH CENTRAL PLAINS THROUGH THE LOWER MISSOURI VALLEY...WITH DEEP SURFACE CYCLONE BECOMING INCREASINGLY OCCLUDED ACROSS EASTERN NEBRASKA. STRONG FORCING FOR UPWARD VERTICAL MOTION/DESTABILIZATION LIKELY WILL MAINTAIN A SUBSTANTIAL SEVERE THREAT ANOTHER FEW HOURS ACROSS PARTS OF THE MID MISSOURI VALLEY...AND PARTS OF THE OZARK PLATEAU. HOWEVER...EXTENT OF THREAT IS MORE UNCERTAIN EASTWARD ACROSS THE MIDDLE MISSISSIPPI INTO THE LOWER OHIO VALLEY...WHERE CONSIDERABLE CLOUD COVER/CONVECTION IMPEDED LOW-LEVEL WARMING TODAY. ...MIDDLE MISSOURI VALLEY*... STRONG SHEAR/FORCING IN EXIT REGION OF 90-100+ KT 500 MB JET STREAK WILL SPREAD FROM EASTERN NEBRASKA/NORTHEAST KANSAS THROUGH EXTREME NORTHWEST MISSOURI/WESTERN IOWA THROUGH 02-03Z. THIS WILL MAINTAIN CONVECTIVE DEVELOPMENT...AND SEVERE THREAT SHOULD PERSIST AS ACTIVITY BEGINS TO INGEST MORE MOIST UNSTABLE BOUNDARY LAYER EAST OF THE MISSOURI RIVER. TONGUE OF 60F+ SURFACE DEW POINTS HAS ADVECTED INTO WESTERN IOWA ON SOUTHEASTERLY FLOW TO THE EAST OF DEEP SURFACE CYCLONE. EASTERLY COMPONENT TO LOW-LEVEL FLOW IS CONTRIBUTING TO ENLARGED HODOGRAPHS...WHICH COULD ENHANCE TORNADO THREAT IN STRONGER CELLS WITHIN DEVELOPING LINE. OTHERWISE... RISK FOR DAMAGING WINDS COULD STILL INCREASE WITH CONVECTIVE LINE ...BEFORE FORCING PIVOTS THROUGH REMAINDER OF INSTABILITY AXIS LATER THIS EVENING. ...OZARK PLATEAU*... SECOND AREA OF ENHANCED SEVERE POTENTIAL EARLY THIS EVENING WILL PERSIST NEAR MID-LEVEL JET CORE...WHERE MID-LEVEL WINDS VEER TO A MORE WESTERLY COMPONENT. THIS IS CONTRIBUTING TO A FAVORABLE HODOGRAPH STRUCTURE FOR MORE DISCRETE SUPERCELLS. POTENTIAL FOR TORNADOES...POSSIBLY STRONG...WILL CONTINUE AS ACTIVITY PROGRESSES THROUGH LINGERING BOUNDARY LAYER INSTABILITY AXIS WITH CAPE TO 2000 J/KG NEAR THE SOUTHEASTERN KANSAS/EASTERN OKLAHOMA BORDER AREAS. DEEPER INTO SOUTH CENTRAL MISSOURI/NORTH CENTRAL ARKANSAS...SEVERE POTENTIAL SEEMS LIKELY TO GRADUALLY DIMINISH ABOVE MORE STABLE BOUNDARY LAYER AFTER 03-04Z. *FOR MORE SPECIFIC AND UPDATED INFORMATION CONCERNING ONGOING OR IMMINENT CONVECTIVE THREATS...PLEASE KEEP WATCH FOR LATEST SPC MESOSCALE DISCUSSIONS. ..KERR.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 06:04:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 02:04:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070602 SWODY1 SPC AC 070601 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT FRI APR 07 2006 VALID 071200Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS MUCH OF NRN MS...NRN AL...AND PARTS OF SRN TN. THIS INCLUDES THE MEMPHIS TN/TUPELO MS AREAS EASTWARD INTO BIRMINGHAM AL AND CHATTANOOGA ...WHICH SEEMS LIKELY TO BE AT THE FOCUS FOR AN OUTBREAK OF SEVERE THUNDERSTORMS...INCLUDING THE RISK FOR SUPERCELLS WITH TORNADOES.... ...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO TONIGHT THROUGH A LARGE PORTION OF THE LOWER MISSISSIPPI VALLEY THROUGH THE TN VLY/SRN APPALACHIANS.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE AND HIGH RISK AREAS...ACROSS MUCH OF THE NATION EAST OF THE MS RIVER INTO THE APPALACHIANS.... THE LARGE-SCALE UPPER FLOW PATTERN HAS BECOME A BIT LESS PROGRESSIVE...BUT MODELS INDICATE THAT THE CENTRAL PLAINS CLOSED LOW WILL GRADUALLY EVOLVE INTO AN OPEN WAVE AND TURN SOUTHEASTWARD TODAY...LIKELY ADVANCING THROUGH MUCH OF THE LOWER MISSISSIPPI VALLEY BY 12Z SATURDAY. THIS IS FORECAST IN RESPONSE TO A SIGNIFICANT SMALLER SCALE IMPULSE ROTATING AROUND ITS SOUTHWESTERN/SOUTHERN PERIPHERY...AND FORCING ASSOCIATED WITH A NORTHERN STREAM TROUGH...WHICH WILL DIG THROUGH THE GREAT LAKES REGION. AS THIS OCCURS...A BROAD BELT OF STRONG CYCLONIC MID/UPPER FLOW IS PROGGED TO CONTINUE TO GRADUALLY OVERSPREAD MUCH OF THE GULF COAST STATES AND MID SOUTH INTO THE NORTHEAST. STRENGTHENING WIND FIELDS/SHEAR PROFILES WILL BECOME JUXTAPOSED WITH A RETURN FLOW OF BOUNDARY LAYER MOISTURE FROM THE WESTERN GULF OF MEXICO...THROUGH A BROAD AREA FROM THE LOWER/MIDDLE MISSISSIPPI VALLEY INTO THE APPALACHIANS. THIS IS EXPECTED TO SUPPORT INCREASING CONVECTIVE POTENTIAL...INCLUDING RISK FOR SEVERE STORMS...WHICH COULD BECOME FAIRLY NUMEROUS AND INTENSE BY THE AFTERNOON/EVENING HOURS. OTHER THUNDERSTORM ACTIVITY APPEARS POSSIBLE INTO CENTRAL PACIFIC COASTAL AREAS. APPROACHING UPPER TROUGH IS FORECAST TO GENERALLY REMAIN OFFSHORE...BUT MODELS INDICATE A FAIRLY SIGNIFICANT IMPULSE WILL PIVOT AROUND ITS EASTERN PERIPHERY...ACROSS THE CALIFORNIA COAST THROUGH THE SIERRA NEVADA BY THE END OF THE FORECAST PERIOD. ...LOWER MISSISSIPPI VALLEY THROUGH SOUTHERN APPALACHIANS... MODELS SUGGEST LEADING EDGE OF MID-LEVEL COOLING ASSOCIATED WITH THE PLAINS SYSTEM WILL OVERSPREAD MUCH OF THE REGION BY MID DAY. THIS WILL WEAKEN INHIBITION...AND SURFACE HEATING MAY BE ENOUGH TO INITIATE AT LEAST SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT AS BOUNDARY LAYER DEW POINTS CLIMB THROUGH THE 60S. AS MIXED LAYER CAPE INCREASES IN EXCESS OF 2000 J/KG...STRONG DEEP LAYER SHEAR WILL BE SUPPORTIVE OF SUPERCELLS. CONFLUENT REGIME ASSOCIATED WITH 30 TO 40 KT SOUTHWESTERLY LOW-LEVEL JET SEEMS A LIKELY FOCUS FOR ACTIVITY...FROM PARTS OF CENTRAL/SOUTHERN MISSISSIPPI THROUGH EASTERN TENNESSEE. SOME OF THESE SUPERCELLS MAY BECOME LONG-LIVED...AND MODELS SUGGEST SUBSTANTIALLY LARGE/CLOCKWISE CURVED HODOGRAPHS ALONG THIS AXIS TO SUPPORT POTENTIAL FOR A FEW STRONG TORNADOES. WITH THE APPROACH OF DIGGING UPPER TROUGH...STRENGTHENING MID/UPPER FORCING IS EXPECTED TO SUPPORT INCREASINGLY WIDESPREAD SEVERE THUNDERSTORMS FROM THE LOWER MISSISSIPPI VALLEY INTO MIDDLE TENNESSEE LATE THIS AFTERNOON INTO THE EVENING HOURS. ACTIVITY MAY BE SLOW TO WEAKEN AS STRONGER FORCING SHIFTS TOWARD THE SOUTHERN APPALACHIANS OVERNIGHT. ...OHIO VALLEY... DEFORMATION ZONE BETWEEN NORTHERN AND SOUTHERN STREAM IMPULSES APPEARS TO BE A LIKELY FOCUS FOR CONVECTIVE DEVELOPMENT TODAY. MODELS SUGGEST FAIRLY STRONG SURFACE HEATING WILL OCCUR ALONG AN AXIS FROM THE ST. LOUIS AREA EASTWARD THROUGH SOUTHERN OHIO... WHICH SHOULD SUPPORT WEAK TO MODERATE DESTABILIZATION AHEAD OF DEVELOPING/STRENGTHENING BAROCLINIC ZONE. FRONTAL ZONE IS PROGGED TO SURGE SOUTH OF THE GREAT LAKES REGION EARLY THIS AFTERNOON... THROUGH MUCH OF THE OHIO VALLEY BY EARLY EVENING. THIS FORCING IS EXPECTED TO BECOME SUFFICIENT FOR AN EVOLVING SQUALL LINE...WITH MIXED LAYER CAPE ON THE ORDER OF 1000 J/KG SUPPORTIVE OF VIGOROUS UPDRAFTS IN STRONG AND SHEARED WESTERLY FLOW. IN ADDITION TO LARGE HAIL...DAMAGING WIND GUSTS COULD BECOME FAIRLY NUMEROUS BY/ SHORTLY AFTER PEAK HEATING. ..KERR/CROSBIE.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 12:20:28 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 08:20:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071217 SWODY1 SPC AC 071216 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0716 AM CDT FRI APR 07 2006 VALID 071300Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS PARTS OF NORTHERN MS...NORTHERN AL...AND SOUTHERN TN... ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE MS VALLEY...TN VALLEY...AND SOUTHERN APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE REMAINDER OF THE OH VALLEY AND CENTRAL APPALACHIANS... ...OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES EXPECTED TODAY ACROSS PARTS OF THE LOWER/MID MS VALLEY AND TN VALLEY... MORNING WATER VAPOR IMAGERY SHOWS LARGE...DEEP UPPER LOW OVER NEB...WITH BAND OF VERY STRONG MID LEVEL WINDS EXTENDING AROUND BASE OF LOW FROM TX/OK INTO AR/MO. THIS SYSTEM IS FORECAST TO MOVE SOUTHEASTWARD TODAY...WITH STRONGEST MID LEVEL WINDS SPREADING ACROSS MUCH OF THE MID/LOWER MS VALLEY AND TN VALLEY. MEANWHILE...SURFACE LOW WILL DEVELOP SOUTHEASTWARD INTO SOUTHERN MO/NORTHERN AR BY EVENING. STRONG SOUTHERLY LOW LEVEL WINDS IN WARM SECTOR OF LOW WILL TRANSPORT RICH MOISTURE NORTHWARD AND HELP TO RAPIDLY DESTABILIZE THE AIR MASS BY EARLY AFTERNOON. ...LA/MS/TN/AL/GA... PRESENT INDICATIONS ARE THAT ISOLATED THUNDERSTORMS WILL DEVELOP BY EARLY AFTERNOON IN LOW LEVEL JET AXIS ACROSS PARTS OF LA/MS. THESE STORMS SHOULD MOVE RAPIDLY EAST-NORTHEASTWARD INTO NORTHERN AL AND MIDDLE TN DURING THE AFTERNOON/EVENING. MODEL FORECAST SOUNDINGS IN THIS REGION INDICATE VERY FAVORABLE LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES FOR SUPERCELLS AND TORNADOES /EFFECTIVE SHEAR OVER 50 KNOTS AND 3KM SRH VALUES OF 250-400 M2/S2/. ASSUMING MID 60S SURFACE DEWPOINTS BECOME WIDESPREAD IN THIS REGION AHEAD OF CONVECTION...THERMODYNAMIC PARAMETERS ALSO APPEAR QUITE FAVORABLE FOR A FEW STRONG/LONG-TRACK TORNADOES /MLCAPE OF 1500-2000 J/KG...MINIMAL CAP...AND LCL HEIGHTS GENERALLY BELOW 1KM/. WIDESPREAD LARGE HAIL WILL BE A THREAT ACROSS THIS REGION AS WELL. ACTIVITY MAY SPREAD AS FAR EAST AS NORTHWEST GA AND EASTERN TN BY LATE EVENING WITH A CONTINUED THREAT OF TORNADOES AND DAMAGING WINDS. ...MID MS/LOWER OH VALLEYS... STRONG DAYTIME HEATING IS EXPECTED ACROSS PARTS OF SERN MO/ERN AR/SRN IL/WRN KY THROUGH EARLY AFTERNOON. THIS SHOULD YIELD VERY STEEP LOW/MID LEVEL LAPSE RATES AND MLCAPE VALUES OVER 2000 J/KG. DEEP LAYER EFFECTIVE SHEAR OVER 60 KNOTS AND SUFFICIENT LOW LEVEL SHEAR WILL PROMOTE SUPERCELL STORMS CAPABLE OF VERY LARGE HAIL AND ISOLATED TORNADOES. ACTIVITY WILL LIKELY SPREAD EASTWARD ACROSS PARTS OF IND/KY/TN THROUGH THE AFTERNOON AND EVENING. ...IL/IND/OH/PA... SURFACE FRONT IS FORECAST TO EXTEND FROM CENTRAL MO INTO NORTHERN OH/NORTHWESTERN PA BY MID AFTERNOON. STRONG HEATING IS EXPECTED ALONG AND SOUTH OF FRONT RESULTING IN AT LEAST MODERATE INSTABILITY. SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO FORM IN THIS REGION AS CONVECTIVE TEMPERATURE IS REACHED AND JET STREAK APPROACHES FROM THE WEST. LARGE HAIL APPEARS TO BE THE MAIN THREAT...ALTHOUGH DAMAGING WINDS WILL ALSO BE POSSIBLE THROUGH THE AFTERNOON/EVENING AS CLUSTERS MERGE AND GROW UPSCALE. ..HART/CROSBIE.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 16:37:31 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 12:37:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071634 SWODY1 SPC AC 071632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT FRI APR 07 2006 VALID 071630Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS PARTS OF NORTHERN MISSISSIPPI...NORTHERN ALABAMA AND WESTERN/MIDDLE TENNESSEE... ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE MS VALLEY...TN VALLEY...LOWER OH VALLEY AND SOUTHERN APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE REMAINDER OF THE OH VALLEY AND CENTRAL APPALACHIANS... ...OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES EXPECTED TODAY INTO TONIGHT ACROSS PARTS OF THE LOWER/MID MS VALLEY AND OH/TN VALLEYS... ...SYNOPSIS... WATER VAPOR IMAGERY THIS MORNING INDICATED DEEP UPPER LOW OVER THE CENTRAL PLAINS HAD BEGUN TO MOVE TOWARD THE ESE....WITH THIS TREND EXPECTED TO CONTINUE TODAY AS LOW REACHES THE LOWER MS/TN VALLEYS BY 12Z SATURDAY. BAND OF VERY STRONG MID LEVEL WINDS WITHIN BASE OF LOW FROM TX/OK INTO LOWER OH VALLEY WILL CONTINUE TO SPREAD DOWNSTREAM ACROSS MUCH OF THE MID/LOWER MS VALLEY AND TN/OH VALLEYS. IN THE LOW LEVELS...SURFACE LOW LOCATED OVER NRN/NERN KS...WILL DEVELOP SOUTHEASTWARD INTO SRN MO/NRN AR BY EVENING. MEANWHILE... A COLD FRONT...ASSOCIATED WITH A STRONG NRN STREAM UPPER TROUGH OVER ERN CANADA...CURRENTLY EXTENDED FROM SRN QUEBEC SWWD THROUGH SRN LOWER MI TO SRN IA. THIS BOUNDARY WILL MOVE SSE ACROSS THE NERN STATES AND OH VALLEY REGION TODAY...AND SHOULD EXTEND FROM THE DELMARVA REGION TO THE TN VALLEY BY 12Z SATURDAY. STRONG SLY LOW LEVEL WINDS IN WARM SECTOR OF LOW AND S OF COLD FRONT WILL TRANSPORT RICH MOISTURE NORTHWARD. ...LA/MS/TN/AL/GA INTO MID MS/OH VALLEYS... SEVERAL ROUNDS OF SEVERE STORMS APPEAR LIKELY ESPECIALLY ACROSS THE HIGH RISK AREA FROM NRN MS/AL INTO WRN/MIDDLE TN...WITH THREAT EXTENDING EWD INTO ERN TN/NRN GA BY THIS EVENING. FORECAST SOUNDINGS CONTINUE TO INDICATE THERMODYNAMIC PARAMETERS QUITE FAVORABLE FOR A FEW STRONG/LONG-TRACK TORNADOES /MUCAPE OF 2000-3000 J/KG AND LCL HEIGHTS GENERALLY BELOW 1KM/ ACROSS NRN MS/NRN AL AND WRN/MIDDLE TN. RAPID DESTABILIZATION IS UNDERWAY WITHIN WEAKLY CAPPED AIR MASS ACROSS THE LOWER/MID MS VALLEYS INTO LOWER OH VALLEY WITH SURFACE DEWPOINTS IN UPPER 50S/LOWER 60S EXPECTED TO SPREAD ACROSS MUCH OF THE OH VALLEY BY THIS AFTERNOON...AND MID 60S ACROSS MUCH OF THE MODERATE AND HIGH RISK AREAS. ABUNDANT SURFACE HEATING WILL CONTINUE TO AID IN THIS DESTABILIZATION PROCESS FURTHER WEAKENING CAP AS INDICATED PER SPECIAL 14Z JAN SOUNDING. PLUME OF STEEP LAPSE RATES WILL SPREAD EWD INTO OH VALLEY AND EXISTING STEEP LAPSE RATES ACROSS REST OF WARM SECTOR WILL COMBINE WITH MOISTURE AND INSOLATION TO RESULT IN MUCAPE RANGING FROM 2000-3000 J/KG ACROSS THE MODERATE AND HIGH RISK AREAS BY THIS AFTERNOON. STRONG VEERING WIND PROFILES WITH HEIGHT /40-50 KT SSWLY LOW-LEVEL WINDS BENEATH 80 KT SWLY MID-LEVEL WINDS/ WILL PROVIDE A FAVORABLE ENVIRONMENT /EFFECTIVE SHEAR OVER 50 KT AND 0-3 KM SRH VALUES OF 250-400 M2/S2/ FOR SUPERCELLS PRODUCING TORNADOES...VERY LARGE HAIL AND DAMAGING WINDS. FARTHER N...AIR MASS WILL CONTINUE TO DESTABILIZE FROM IL/IND EWD ACROSS OH/PA IN ADVANCE OF THE COLD FRONT. STRENGTHENING WIND FIELDS WILL RESULT IN FAVORABLE DEEP LAYER SHEAR FOR THUNDERSTORMS TO DEVELOP AS THE COLD FRONT MOVES SSEWD INTO THE MODERATELY UNSTABLE AIR MASS. DEEP LAYER SHEAR VECTORS ORIENTED NEARLY PARALLEL TO THE FRONT SUGGEST ACTIVITY WILL PRIMARILY BE LINEAR... BUT SUPERCELLS WITH AN ATTENDANT TORNADO THREAT WILL BE POSSIBLE ESPECIALLY ACROSS SRN IL/IND INTO SRN OH WHERE LOW-LEVEL MOISTURE WILL BE GREATER. ...CENTRAL APPALACHIANS... SEVERE THREAT MAY DEVELOP AS FAR EAST AS THE CENTRAL APPALACHIANS AS AIR MASS DESTABILIZES IN THE WAKE OF MORNING SHOWERS/ THUNDERSTORMS. STRONG DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ORGANIZED STORMS INTO PARTS OF SRN PA AND POTENTIALLY WRN MD/ERN WV AS MLCAPE VALUES REACH AROUND 1000 J/KG. ADDITIONAL STRONG TO SEVERE STORMS THAT DEVELOP ACROSS THE OH/TN VALLEYS TODAY SHOULD APPROACH THE CENTRAL/SRN APPALACHIANS THIS EVENING...BUT EWD SEVERE THREAT WILL BE LIMITED BY DIMINISHING INSTABILITY OVERNIGHT. ...PARTS OF KS/OK/WRN MO/NWRN AR... COLD MID LEVEL TEMPERATURES WITH CENTRAL PLAINS LOW ATOP PROGGED WEAK LOW-LEVEL WARM AIR ADVECTION SHOULD RESULT IN DESTABILIZING THE AIR MASS ACROSS THIS REGION FOR A FEW THUNDERSTORMS THIS AFTERNOON. WEAK INSTABILITY/SHEAR WILL TEND TO LIMIT THE SEVERE POTENTIAL...BUT A FEW OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL DIMINISH THIS EVENING GIVEN THE ONSET OF STABILIZATION PER THE LOSS OF DAY TIME HEATING. ..PETERS/GRAMS.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:04:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:04:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072001 SWODY1 SPC AC 071959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:10:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:10:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072007 SWODY1 SPC AC 072006 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:18:16 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:18:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072014 SWODY1 SPC AC 072013 DAY 1 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0313 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Sat Apr 8 06:03:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 02:03:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080559 SWODY1 SPC AC 080558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SAT APR 08 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS THE EASTERN GULF STATES INTO THE SOUTHERN/MID ATLANTIC COAST.... SOUTHERN STREAM SHORT WAVE TROUGH HAS FINALLY BECOME MORE PROGRESSIVE...AND IS NOW DIGGING THROUGH THE LOWER MISSISSIPPI VALLEY...MORE OR LESS IN PHASE WITH A VIGOROUS NORTHERN BRANCH TROUGH DIGGING INTO THE LOWER GREAT LAKES/ST. LAWRENCE VALLEY. MODELS SUGGEST NORTHERN SYSTEM WILL RAPIDLY PIVOT THROUGH NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES DURING THIS FORECAST PERIOD. SOUTHERN IMPULSE IS PROGGED TO BE A BIT SLOWER...BUT APPEARS LIKELY TO GRADUALLY TAKE ON MORE OF A NEUTRAL TILT AS IT APPROACHES THE MID/SOUTH ATLANTIC COAST BY 12Z SUNDAY. SURFACE COLD INTRUSIONS ASSOCIATED WITH BOTH FEATURES WILL EVENTUALLY SURGE THROUGH THE LEE OF THE SOUTHERN APPALACHIANS... AND THROUGH THE REMAINDER OF THE CENTRAL/EASTERN GULF STATES. HOWEVER...THIS GENERALLY WILL NOT OCCUR UNTIL LATER TODAY/TONIGHT. PRE-FRONTAL ENVIRONMENT IS BECOMING INCREASINGLY MOIST ACROSS THE EASTERN GULF STATES...AND SIMILAR MOISTENING IS POSSIBLE OVER SOUTH ATLANTIC COASTAL AREAS AS SURFACE RIDGING FINALLY WEAKENS/RETREATS TO THE EAST. SURFACE DEW POINTS AT OR ABOVE 60F MAY OVERSRPREAD MUCH OF THE SOUTHEAST BY MIDDAY. COOLING/DRYING IN WAKE OF COLD FRONTS...BENEATH BROADLY ANTICYCLONIC UPPER FLOW DEVELOPING INTO THE CENTRAL/EASTERN STATES SHOULD PRECLUDE CONVECTIVE POTENTIAL MOST OTHER AREAS EAST OF THE ROCKIES. ACROSS THE WEST...MAIN SHORT WAVE IMPULSE WITHIN BROADER SCALE TROUGH WILL REMAIN WEST OF THE PACIFIC COAST THROUGH THIS PERIOD. BUT...WEAKER IMPULSE ALREADY LIFTING OUT OF TROUGH INTO THE NORTHERN INTERMOUNTAIN REGION WILL CONTINUE THROUGH THE NORTHERN ROCKIES BY LATE TONIGHT. ...SOUTHEAST... MODERATELY STRONG AND SHEARED FLOW REGIME WILL DEVELOP ACROSS MUCH OF THE REMAINDER OF THE EASTERN GULF/SOUTH ATLANTIC COAST STATES TODAY. PRIMARY UNCERTAINTY CONCERNING EXTENT OF SEVERE THREAT INVOLVES INFLUENCE OF CONVECTIVE SYSTEM EXPECTED TO BE ONGOING FROM THE LEE OF THE SOUTHERN APPALACHIANS THROUGH PARTS OF SOUTHERN ALABAMA/MISSISSIPPI AT 12Z. LOWER LEVELS IN THE LEE OF THE APPALACHIANS MAY STILL BE TOO DRY EARLY IN THE DAY TO SUPPORT CONTINUING SEVERE THREAT ACROSS THE SOUTH ATLANTIC COAST STATES... AND CLOUD COVER WITH DISSIPATING CONVECTION COULD IMPEDE SURFACE HEATING. BEST MOIST INFLOW INTO CONVECTION IS EXPECTED ACROSS NORTHERN FLORIDA INTO SOUTHERN GEORGIA...WHERE LINE OF STRONG/SEVERE STORMS ...PRIMARILY WITH HAIL/DAMAGING WINDS...APPEARS POSSIBLE THIS MORNING INTO EARLY AFTERNOON. OTHERWISE...AIR MASS MAY BECOME SUFFICIENTLY UNSTABLE IN WAKE OF EARLY CONVECTION FOR SCATTERED SEVERE STORMS AHEAD OF COLD FRONT ACROSS CENTRAL/SOUTHEAST ALABAMA. STORMS SHOULD FORM AS MID-LEVEL THERMAL TROUGH AXIS OVERSPREADS ALABAMA DURING THE AFTERNOON HOURS...AND ACTIVITY COULD SPREAD BACK INTO SOUTHERN GEORGIA BEFORE WEAKENING. FARTHER EAST...THOUGH CAPE MAY NOT BECOME PARTICULARLY STRONG...FORCING AHEAD OF SOUTHERN BRANCH TROUGH COULD BECOME SUPPORTIVE OF A NEW LINE OF STORMS BY LATE AFTERNOON ACROSS PARTS OF THE EASTERN CAROLINAS/SOUTHEAST VIRGINIA. SHEAR WILL BE MORE THAN SUFFICIENT FOR UPDRAFT ROTATION...BUT PRIMARY SEVERE THREAT SEEMS LIKELY TO BE DAMAGING WINDS AND HAIL IN 40 TO 50+ KT SOUTHWESTERLY MEAN FLOW. ..KERR/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 12:27:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 08:27:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081224 SWODY1 SPC AC 081223 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0723 AM CDT SAT APR 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... WATER VAPOR IMAGERY THIS MORNING SHOWS UPPER TROUGH OVER THE MID MS VALLEY. THIS FEATURE WILL TRACK EASTWARD TODAY THROUGH THE TN VALLEY...WHILE SURFACE COLD FRONT SWEEPS TOWARD THE SOUTHEAST COAST. OVERALL SEVERE THREAT WILL BE SIGNIFICANTLY LESS THAN YESTERDAY. HOWEVER...POTENTIAL WILL EXIST FOR ISOLATED LARGE HAIL...DAMAGING WINDS...AND TORNADOES OVER PARTS OF THE SOUTHEAST STATES. ...AL/GA/SC/NC/VA/FL... BAND OF STRONG CONVECTION CURRENTLY EXTENDS FROM CENTRAL AL...ACROSS CENTRAL GA...INTO CENTRAL NC. VISIBLE SATELLITE IMAGERY SUGGESTS THAT POCKETS OF DAYTIME HEATING WILL DEVELOP AHEAD OF LINE...RESULTING IN LATE MORNING/EARLY AFTERNOON MLCAPE VALUES OF 1000-1500 J/KG. THIS WILL AID IN THE RE-INTENSIFICATION OF STORMS BEFORE NOON ACROSS SOUTHEAST VA...EASTERN CAROLINAS...AND SOUTHERN GA/AL. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE MAIN THREAT. STRONG DEEP LAYER VERTICAL SHEAR WILL BE PRESENT ACROSS THIS REGION PROMOTING POTENTIAL FOR A FEW SUPERCELLS AND PERHAPS TORNADOES. ACTIVITY SHOULD SPREAD SOUTHEASTWARD INTO NORTHERN FL DURING THE LATE AFTERNOON/EARLY EVENING BEFORE WEAKENING. ELSEWHERE ACROSS THE NATION...NO SEVERE THUNDERSTORMS ARE FORECAST TODAY. ..HART/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 12:27:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 08:27:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081224 SWODY1 SPC AC 081223 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0723 AM CDT SAT APR 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... WATER VAPOR IMAGERY THIS MORNING SHOWS UPPER TROUGH OVER THE MID MS VALLEY. THIS FEATURE WILL TRACK EASTWARD TODAY THROUGH THE TN VALLEY...WHILE SURFACE COLD FRONT SWEEPS TOWARD THE SOUTHEAST COAST. OVERALL SEVERE THREAT WILL BE SIGNIFICANTLY LESS THAN YESTERDAY. HOWEVER...POTENTIAL WILL EXIST FOR ISOLATED LARGE HAIL...DAMAGING WINDS...AND TORNADOES OVER PARTS OF THE SOUTHEAST STATES. ...AL/GA/SC/NC/VA/FL... BAND OF STRONG CONVECTION CURRENTLY EXTENDS FROM CENTRAL AL...ACROSS CENTRAL GA...INTO CENTRAL NC. VISIBLE SATELLITE IMAGERY SUGGESTS THAT POCKETS OF DAYTIME HEATING WILL DEVELOP AHEAD OF LINE...RESULTING IN LATE MORNING/EARLY AFTERNOON MLCAPE VALUES OF 1000-1500 J/KG. THIS WILL AID IN THE RE-INTENSIFICATION OF STORMS BEFORE NOON ACROSS SOUTHEAST VA...EASTERN CAROLINAS...AND SOUTHERN GA/AL. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE MAIN THREAT. STRONG DEEP LAYER VERTICAL SHEAR WILL BE PRESENT ACROSS THIS REGION PROMOTING POTENTIAL FOR A FEW SUPERCELLS AND PERHAPS TORNADOES. ACTIVITY SHOULD SPREAD SOUTHEASTWARD INTO NORTHERN FL DURING THE LATE AFTERNOON/EARLY EVENING BEFORE WEAKENING. ELSEWHERE ACROSS THE NATION...NO SEVERE THUNDERSTORMS ARE FORECAST TODAY. ..HART/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 16:31:21 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 12:31:21 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081623 SWODY1 SPC AC 081621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT SAT APR 08 2006 VALID 081630Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... ...SERN STATES... VIGOROUS UPPER TROUGH FROM OH VALLEY TO LOWER MS VALLEY WILL CONTINUE EWD REACHING ATLANTIC COAST LATE TONIGHT. COLD FRONT FROM DELMARVA SWWD THRU ERN TN VALLEY TO OFFSHORE SERN LA WILL BE TRAILING SWWD ACROSS CENTRAL FL PENINSULA INTO GULF BY LATER TONIGHT. PREFRONTAL CONVECTION HAS CONTINUED OVERNIGHT WITH A WELL DEFINED BOUNDARY TRAILING WWD ACROSS CENTRAL GA INTO SRN AL. WARM SECTOR TO S AND E OF THIS BOUNDARY HAS BECOME MDTLY UNSTABLE EWD INTO SRN SC. WARM SECTOR CHARACTERIZED BY STRONG DEEP LAYER SHEAR OF 60-70 KT ALONG WITH SFC-1KM SHEAR AROUND 20KT WHICH SUPPORTS ORGANIZED THUNDERSTORMS INCLUDING SUPERCELLS THIS AFTERNOON AND EVENING. WITH MLCAPES TO 2000 J/K AND MID LEVEL LAPSE RATES IN EXCESS OF 7C/KM AND AS OF 16Z MINIMAL REMAINING CIN...THUNDERSTORMS WILL INCREASE IN BOTH NUMBER AND INTENSITY THRU THE MIDDLE OF THE AFTERNOON EWD ACROSS SRN GA/NRN FL INTO COASTAL SC. SUPERCELLS ARE LIKELY WITH THE MOST FAVORED AREA FOR TORNADO POTENTIAL IN THE ENHANCE SHEAR ALONG THE E/W BOUNDARY THAT EXTENDS ACROSS GA JUST S OF MCN. THUNDERSTORMS WILL DEVELOP FROM CURRENT LOCATION CENTRAL GA TO SRN AL E AND NEWD DURING AFTERNOON INTO SRN SC AND THRU THE FL PANHANDLE AS HEATING CONTINUES. THREAT FOR LARGE HAIL AND ISOLATED TORNADOS WILL INCREASE ACCORDINGLY. FURTHER N THE EARLIER CONVECTIVE ACTIVITY HAS MOVED OFFSHORE AND COASTAL NC/SERN VA SHOULD HAVE TIME TO RECOVER AND DESTABILIZE PRIOR TO THE ARRIVAL OF THE COLD FRONT. AS A RESULT WILL CONTINUE THREAT OF REDEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS COASTAL AREAS WITH THE STRONG PREDOMINANTLY UNIDIRECTIONAL FLOW FAVORING LARGE HAIL AND DAMAGING WINDS ..HALES/GRAMS.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 19:46:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 15:46:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081944 SWODY1 SPC AC 081942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0242 PM CDT SAT APR 08 2006 VALID 082000Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... ...SERN STATES... EARLY AFTERNOON SURFACE ANALYSIS SHOWED SYNOPTIC COLD FRONT EXTENDED FROM SERN VA WSWWD THROUGH WRN NC/SC TO NERN GA...AND THEN SWWD ACROSS CENTRAL GA/SERN AL TO OVER THE NRN GULF OF MEXICO. PRIMARY FOCI FOR ONGOING AND ADDITIONAL THUNDERSTORMS EXPECTED TO BE SRN EXTENT OF COLD FRONT...NOW LOCATED OVER SERN AL/WRN FL PANHANDLE...AND PRE-FRONTAL TROUGH/OUTFLOW BOUNDARIES MOVING E/SE ACROSS ERN CAROLINAS AND SRN GA/FL PANHANDLE INTO NRN FL. WARM SECTOR AIR MASS WILL REMAIN UNSTABLE INTO THE EVENING...WITH GREATEST INSTABILITY /MLCAPE 1000-2000 J/KG/ EXTENDING ACROSS SRN SC/SRN GA/FAR SERN AL/FL PANHANDLE AND NRN FL. STRONG CENTRAL GULF COAST STATES SHORT WAVE TROUGH WILL CONTINUE EWD REACHING THE SRN ATLANTIC COAST BY 12Z SUNDAY. LARGE SCALE ASCENT IN ADVANCE OF THIS TROUGH AND ENHANCED LOW-LEVEL CONVERGENCE IN THE VICINITY OF A COUPLE OF FRONTAL WAVES...NOW LOCATED OVER SRN AL/SRN GA...AND BOUNDARIES WILL MAINTAIN DEEP MOIST CONVECTION WITHIN UNSTABLE WARM SECTOR. SUPERCELLS AND LINES/BOWS ARE EXPECTED TO REMAIN LIKELY GIVEN STRONG DEEP LAYER AND LOW-LEVEL SHEAR WITHIN MODERATELY UNSTABLE ENVIRONMENT. HAIL/DAMAGING WINDS WILL BE LIKELY WITHIN ENTIRE WARM SECTOR. GREATEST TORNADO THREAT EXPECTED TO BE ACROSS FAR SERN AL/FL PANHANDLE EWD THROUGH SRN GA/NRN FL TO SRN SC WHERE INSTABILITY WILL REMAIN THE GREATEST...AND DEEP LAYER SHEAR VECTORS ARE ORIENTED MORE NORMAL TO THE BOUNDARIES ALLOWING FOR DISCRETE STORMS. THREAT FOR SEVERE STORMS WILL CONTINUE INTO THE MID-LATE EVENING AND OVERNIGHT AS PRE-FRONTAL CONVECTIVE BAND AND COLD FRONT MOVE INTO NRN FL WHERE EFFECTIVE SHEAR/INSTABILITY SHOULD REMAIN CONDUCIVE FOR ORGANIZED STORMS. ..PETERS.. 04/08/2006  From SwoDy1 at goshenarc.org Sun Apr 9 00:45:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 20:45:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090043 SWODY1 SPC AC 090041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 PM CDT SAT APR 08 2006 VALID 090100Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER FAR SERN GA SWD INTO NRN AND CNTRL FL... ...SERN GA / NRN AND CNTRL FL... CLUSTERS OF STRONG TO SEVERE TSTMS ARE ONGOING THIS EVENING FROM NEAR AND N OF JAX SWWD INTO THE NERN GULF OF MEXICO AHEAD OF SRN STREAM MID-LEVEL TROUGH EXTENDING FROM THE SRN APPALACHIANS SWD INTO THE CNTRL GULF OF MEXICO. MOIST BOUNDARY-LAYER CONDITIONS COUPLED WITH MODEST LAPSE RATES ARE SUSTAINING A MODERATELY UNSTABLE AIR MASS AHEAD OF THESE STORMS PER 00Z JAX/TBW SOUNDINGS WITH MLCAPES OF 1000-1500 J/KG. STRONGEST MID AND HIGH-LEVEL WIND FIELDS ARE FORECAST TO LIFT NEWD ACROSS THE WRN ATLANTIC IN ADVANCE OF MORE PROGRESSIVE NRN STREAM TROUGH MOVING THROUGH THE NRN AND CNTRL APPALACHIANS. HOWEVER...40-45 KT WLY MID-LEVEL FLOW WILL BE SUSTAINED ACROSS PRE-FRONTAL INSTABILITY AXIS ACROSS THE CNTRL FL PENINSULA OVERNIGHT. HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH SHOULD MAINTAIN NE-SW ORIENTED BANDS OF TSTMS THROUGH THE REMAINDER OF THE EVENING INTO OVERNIGHT WITH THIS ACTIVITY GRADUALLY SHIFTING SWD INTO THE CNTRL PENINSULA. GIVEN THE MODEST LAPSE RATES AND MODERATELY STRONG UNIDIRECTIONAL WIND FIELDS...POTENTIAL WILL EXIST FOR ISOLATED DAMAGING WIND GUSTS AND SEVERE HAIL WITH THE MOST INTENSE STORMS. ..MEAD.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 05:18:43 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 01:18:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090515 SWODY1 SPC AC 090514 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1214 AM CDT SUN APR 09 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER S FL... ...SYNOPSIS... NRN STREAM MID-LEVEL TROUGH FROM QUEBEC SWD TO THE MIDDLE ATLANTIC COAST WILL BECOME NEGATIVELY TILTED OVER THE CANADIAN MARITIMES...WHILE WEAKER SRN STREAM TROUGH WILL MORE SLOWLY SHIFT EWD ACROSS THE ERN GULF OF MEXICO THROUGH FL INTO THE WRN ATLANTIC. IN THE W...NEXT UPSTREAM TROUGH WILL EVOLVE OVER THE PACIFIC NW AND GREAT BASIN...WITH AN ASSOCIATED VORTICITY MAXIMUM/JET STREAK MOVING THROUGH THE MEAN TROUGH NEWD INTO NV/UT. IN THE LOW-LEVELS...COLD FRONT INITIALLY OVER THE NRN FL PENINSULA WILL PUSH SWD THROUGH REMAINDER OF THE PENINSULA TODAY...EVENTUALLY INTO THE FL STRAITS LATE TONIGHT. IN THE W...SURFACE LOW OVER NV WILL DEVELOP NEWD INTO NRN HIGH PLAINS IN ADVANCE OF EVOLVING UPPER TROUGH WHILE TRAILING PACIFIC FRONT PUSHES EWD INTO THE GREAT BASIN. ...S FL... 09/00Z UPPER AIR AND CURRENT SURFACE OBSERVATIONS INDICATE THE PRESENCE OF A VERY MOIST LOW-LEVEL AIR MASS WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. THIS MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO THE DEVELOPMENT OF MODERATE INSTABILITY TODAY AHEAD OF COLD FRONT WITH MLCAPES INCREASING TO 1500-2000 J/KG. W-E ORIENTED BANDS OF TSTMS WILL LIKELY BE ONGOING AT THE ONSET OF FORECAST OVER THE CNTRL PENINSULA WITHIN MOIST...PRE-FRONTAL WARM SECTOR. DESTABILIZATION OF INFLOW AIR MASS ALONG WITH 30 METER HEIGHT FALLS ALONG SRN FRINGE OF SRN STREAM TROUGH MOVING THROUGH THE AREA SHOULD SUPPORT STORM INTENSIFICATION LATER TODAY...WITH THE POTENTIAL FOR A FEW SEVERE STORMS CONTINUING INTO THIS EVENING. FORECAST SOUNDINGS SUGGEST THAT VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG OWING TO THE VEERED LOW-LEVEL WINDS AND ONLY 30-40 KT FLOW IN THE MID-LEVELS. NONETHELESS...THE MODERATE INSTABILITY AND UNIDIRECTIONAL WIND PROFILES SUGGEST THE POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS AND PERHAPS SEVERE HAIL WITH THE MOST INTENSE STORMS. ..MEAD/GUYER.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 12:46:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 08:46:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091242 SWODY1 SPC AC 091241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 AM CDT SUN APR 09 2006 VALID 091300Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FL... ...SYNOPSIS... PRIMARY SEVERE THREAT THROUGH THE DAY/EARLY EVENING WILL RESIDE ACROSS SOUTHERN FL...WHERE ISOLATED SEVERE STORMS ARE POSSIBLE ALONG/SOUTH OF COLD FRONT ACROSS THE FL PENINSULA. IN THE WEST...THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF NORTHERN/CENTRAL CA AND ORE/WA INTO THE INTERMOUNTAIN WEST IN ASSOCIATION WITH UPPER TROUGH ALONG THE WEST COAST. OTHERWISE...DRY/STABLE CONDITIONS WILL PRECLUDE THUNDERSTORMS ACROSS THE REMAINDER OF THE CONUS. ...SOUTH FL... SCATTERED THUNDERSTORM CLUSTERS CONTINUE THIS MORNING ALONG/SOUTH OF COLD FRONT ROUGHLY BISECTING THE FL PENINSULA AND ADJACENT COASTAL WATERS. AS THE FRONT SLOWLY PROGRESSES SOUTHWARD...SCATTERED THUNDERSTORMS WILL FURTHER INCREASE IN COVERAGE ACROSS SOUTH FL...WITH POTENTIAL FOR AT LEAST ISOLATED SEVERE STORMS THROUGH THE AFTERNOON/EARLY EVENING. MODEST INSOLATION COUPLED WITH A RATHER MOIST/UNSTABLE AIRMASS WILL YIELD MLCAPE VALUES OF 1500-2000 J/KG BY THE AFTERNOON ACROSS SOUTH FL...PER MODIFIED 12Z MIAMI/KEY WEST/TAMPA BAY MORNING RAOBS. ALTHOUGH SOMEWHAT NEGATED BY MODEST VERTICAL SHEAR/UNIDIRECTIONAL WIND PROFILES WITHIN THE AMBIENT WARM SECTOR...THERMODYNAMIC CHARACTERISTICS WILL SUPPORT THE POTENTIAL FOR DAMAGING WIND GUSTS AND/OR LARGE HAIL WITH THE STRONGEST STORMS. ..GUYER/HART.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 16:11:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 12:11:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091608 SWODY1 SPC AC 091606 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 AM CDT SUN APR 09 2006 VALID 091630Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FLORIDA... ...SOUTH FLORIDA... THE TAIL END OF THE TROUGH NOW MOVING OFF THE E COAST WILL SLOWLY DRAG ACROSS FL TODAY. S FL 12Z SOUNDINGS REFLECT THE APPROACHING TROUGH WITH MID LEVEL LAPSE RATES OF 7C/KM AND UPWARDS OF 40KT OF DEEP LAYER SHEAR. ADDITIONALLY THE SWLY FLOW HAS SPREAD A MARITIME TROPICAL AIR MASS INLAND TO S OF THE COLD FRONT WHICH CURRENTLY EXTENDS E/W JUST S OF A MLB TO TPA LINE. WITH SFC TEMPS CURRENTLY IN THE MID 80S AND DEWPOINTS HOLDING NEAR 70F SERN FL... CONVECTIVE INHIBITION IS GONE AND MLCAPES HAVE CLIMBED TO ABOVE 2000 J/KG. STRONG/SEVERE THUNDERSTORMS WILL INITIATE VICINITY SUBTLE SURFACE BOUNDARIES SUCH AS S COAST SEA BREEZE AND CURRENT CONVECTIVE COMPLEX PROPAGATING SWD ALONG E COAST. ADDITIONAL STORMS WILL THEN DEVELOP THRU THE AFTERNOON IN RESPONSE TO CONVECTIVE BOUNDARIES THAT EMANATE FROM INITIAL ACTIVITY PRIMARY CONVECTIVE MODE WILL BE MULTI-CELL GIVEN THE WEAK LOW LEVEL SHEAR...HOWEVER ROTATING STORMS ARE POSSIBLE WITH THE FAVORABLE THERMODYNAMICS AND MDT DEEP LAYER SHEAR. LARGE HAIL AND DOWNBURSTS WINDS ARE LIKELY WITH STRONGEST ACTIVITY. ..HALES/GRAMS.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 19:51:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 15:51:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091949 SWODY1 SPC AC 091947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SUN APR 09 2006 VALID 092000Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTH FLORIDA... ...SOUTH FLORIDA... 19Z SURFACE ANALYSIS SHOWED THE COLD FRONT EXTENDED FROM 35 SSE VRB WWD TO NRN PART OF LAKE OKEECHOBEE...THEN WNWWD TO THE FL GULF COAST NEAR SRQ BEFORE EXTENDING WWD INTO THE GULF. VIS IMAGERY SHOWED A COUPLE OF OUTFLOW BOUNDARIES OVER S FL...ONE NEAR THE S FL COAST AND THE SECOND LOCATED TO THE E AND S OF LAKE OKEECHOBEE. THESE BOUNDARIES AND OTHER CONVECTIVE OUTFLOW/SEA-LAKE BREEZE BOUNDARIES WILL BE THE FOCI FOR ADDITIONAL ACTIVITY THIS AFTERNOON INTO THE EVENING. MID AFTERNOON SATELLITE/RADAR IMAGERY AND LIGHTNING DATA INDICATED TWO LARGER CLUSTERS OF STORMS /1. ALONG/OFF THE SERN FL COAST AND 2. OVER THE SERN GULF TO THE W/SW OF KEY WEST MOVING GENERALLY SWD/. MORE RECENT THUNDERSTORM DEVELOPMENT WAS NOTED ALONG THE COLD FRONT. CIRRUS SHIELD ASSOCIATED WITH THE SERN GULF CLUSTER TEMPORARILY DECREASED SURFACE HEATING ACROSS PARTS OF S/SW FL EARLIER THIS AFTERNOON. HOWEVER...MORE RECENT TREND OF THINNING CLOUD SHIELD WILL ALLOW ADDITIONAL INSOLATION TO MAINTAIN A MODERATELY UNSTABLE /MLCAPE AOA 1500 J/KG/ WARM SECTOR. UNIDIRECTIONAL WINDS AND DEEP LAYER SHEAR AOB 25 KT WILL CONTINUE TO SUPPORT MULTICELLS WITH HAIL/ STRONG WIND GUSTS AS THE PRIMARY THREATS INTO THE EVENING...AS THE COLD FRONT MOVES SWD ACROSS S FL. ..PETERS.. 04/09/2006  From SwoDy1 at goshenarc.org Mon Apr 10 00:49:32 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 20:49:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100046 SWODY1 SPC AC 100045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0745 PM CDT SUN APR 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...S FL... SURFACE COLD FRONT /JUST N OF LAKE OKEECHOBEE AS OF 00Z/ WILL CONTINUE TO SAG SWD TONIGHT IN WAKE OF MID LEVEL TROUGH SHIFTING EWD INTO THE WRN ATLANTIC. TSTM ACTIVITY OCCURRING ALONG FRONT AND ADDITIONAL PRE-FRONTAL MESOSCALE OUTFLOW BOUNDARIES CONTINUE TO WEAKEN THIS EVENING OWING TO COOLING AND SLOW STABILIZATION OF BOUNDARY-LAYER...AND PASSAGE OF STRONGER LARGE-SCALE FORCING TO THE E. 00Z MIA SOUNDING DID INDICATE THAT AIR MASS REMAINS MODESTLY UNSTABLE OVER FAR S FL AND ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE THROUGH THE EVENING. GUSTY WINDS MAY ACCOMPANY ANY STORMS THAT DEVELOP...THOUGH IT APPEARS THAT THE SEVERE WEATHER THREAT HAS DIMINISHED SUFFICIENTLY SUCH THAT INDIVIDUAL PROBABILITIES WILL BE REMOVED FROM THE FORECAST. ..MEAD.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 05:29:00 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 01:29:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100525 SWODY1 SPC AC 100524 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 AM CDT MON APR 10 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FLATTENING OF WRN CONUS LONG WAVE TROUGH IS FORECAST THROUGH THE DAY ONE PERIOD AS SHORT WAVE TROUGH NOW FROM ERN ORE SWD INTO WRN NV DE-AMPLIFIES WHILE LIFTING NEWD THROUGH THE NRN HIGH PLAINS INTO S-CNTRL CANADA. MEANWHILE...UPSTREAM SHORT WAVE TROUGH /CURRENTLY DIGGING SWD NEAR 35N AND 129 W/ WILL TURN MORE EWD ACROSS THE LOWER CO VALLEY AND INTO THE 4-CORNERS REGION BY TUESDAY MORNING. IN THE LOW-LEVELS...CURRENT SURFACE DATA SHOW LEE CYCLOGENESIS IN PROGRESS OVER THE NRN AND CNTRL HIGH PLAINS...AND THIS PROCESS WILL CONTINUE THROUGH THE DAY WITH MAIN SURFACE LOW CONSOLIDATING OVER NERN WY BY LATE AFTERNOON. THIS LOW WILL THEN DEVELOP NEWD INTO THE RED RIVER VALLEY TONIGHT...IN ADVANCE OF SHORT WAVE TROUGH EJECTING ACROSS THE REGION. MEANWHILE...ASSOCIATED WARM FRONT WILL CONCURRENTLY LIFT NWD THROUGH THE NRN PLAINS AND UPPER MS VALLEY WHILE TRAILING COLD FRONT PUSHES EWD OUT OF THE NRN ROCKIES INTO THE DAKOTAS AND NEB. ...ERN MT / NERN WY EWD INTO THE DAKOTAS AND NRN MN... GOES PW LOOP AND SURFACE DATA INDICATE THAT AIR MASS ACROSS THE PLAINS REMAINS QUITE DRY WITH DEWPOINTS LARGELY IN THE 30 AND 40S. LITTLE INCREASE IN LOW-LEVEL MOISTURE IS FORECAST AND THIS WILL LIMIT A MORE ORGANIZED SEVERE WEATHER THREAT THIS AFTERNOON INTO OVERNIGHT. NONETHELESS...DAYTIME HEATING COUPLED WITH HEIGHT FALLS AHEAD OF SHORT WAVE TROUGH WILL CONTRIBUTE TO THE DEVELOPMENT OF STEEP LAPSE RATES AND RESULTANT WEAK INSTABILITY LATER TODAY AHEAD OF DEVELOPING SURFACE LOW AND TRAILING COLD FRONT. TSTM DEVELOPMENT WILL BECOME INCREASINGLY LIKELY BY MID TO LATE AFTERNOON ALONG OR PERHAPS IN IMMEDIATE WAKE OF COLD FRONT OVER ERN MT SWD INTO NERN WY. THIS ACTIVITY WILL LIKELY MOVE/DEVELOP EWD OR NEWD INTO PORTIONS OF WRN SD AND WRN/CNTRL ND THIS EVENING...PRIOR TO WEAKENING. POTENTIAL WILL EXIST FOR A FEW LOCALLY STRONG WIND GUSTS AND MARGINALLY SEVERE HAIL GIVEN THE STEEP LAPSE RATES...MODEST DEEP-LAYER SHEAR AND DRY SUB-CLOUD CONDITIONS. ADDITIONAL MORE ELEVATED STORMS WILL BE POSSIBLE OVERNIGHT N OF SURFACE WARM FRONT OVER THE RED RIVER VALLEY EWD ACROSS FAR NRN MN. THE STEEP MID LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 500-700 J/KG MAY SUPPORT SOME HAIL WITH THE MOST INTENSE STORMS. ..MEAD/CROSBIE.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 12:26:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 08:26:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101223 SWODY1 SPC AC 101222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0722 AM CDT MON APR 10 2006 VALID 101300Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN HIGH PLAINS... MORNING WATER VAPOR IMAGERY SHOWS LARGE SCALE TROUGH DEVELOPING OVER THE WESTERN UNITED STATES...WITH UPPER RIDGE CONTINUING OVER THE SOUTHERN PLAINS AND MS VALLEY. ONE STRONG SHORTWAVE TROUGH IS CURRENTLY OVER ID/UT. THIS FEATURE IS FORECAST TO ROTATE EASTWARD INTO PARTS OF MT/WY AND THE DAKOTAS THIS EVENING. SURFACE LOW IS EXPECTED TO DEEPEN IN ADVANCE OF THIS FEATURE OVER WESTERN SD...RESULTING IN STRENGTHENING SOUTHERLY LOW LEVEL FLOW OVER THE NORTHERN PLAINS. THIS WILL HELP TO DRAW MEAGER LOW LEVEL MOISTURE INTO REGION. STRONG DAYTIME HEATING FROM THE BLACK HILLS REGION INTO EASTERN MT WILL PROVIDE STEEP LAPSE RATES AND MARGINAL AFTERNOON INSTABILITY /MLCAPE BELOW 1000 J/KG/. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP IN THIS REGION BY LATE AFTERNOON. COLD TEMPERATURES ALOFT...STEEP LAPSE RATES...AND SUFFICIENT WIND FIELDS WILL POSE A RISK OF ISOLATED STRONG STORMS CAPABLE OF GUSTY WINDS AND HAIL. ORGANIZED SEVERE STORMS ARE NOT EXPECTED TODAY. ISOLATED STRONG STORMS MAY SPREAD NORTHEASTWARD INTO PARTS OF ND/MN OVERNIGHT WITH A CONTINUED THREAT OF HAIL. ELSEWHERE...NO ORGANIZED SEVERE STORMS ARE ANTICIPATED TODAY. ..HART/CROSBIE.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 16:38:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 12:38:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101632 SWODY1 SPC AC 101630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT MON APR 10 2006 VALID 101630Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN PLAINS... WHILE PRIMARY TROUGH REMAINS ALONG OR JUST OFF W COAST A BROAD SWLY FLOW WITH EMBEDDED S/WVS EXTENDS EWD INTO THE NRN PLAINS. ONE IMPULSE CURRENTLY NRN ROCKIES WITH UPSTREAM IMPULSE MOVING INLAND SRN CA THIS AFTERNOON. SURFACE LOW NERN WY THIS AM WITH A STRONG SLY LOW LEVEL JET TO THE E OVER THE PLAINS. LOW WILL MOVE NEWD ACROSS DAKOTAS TOWARD NWRN MN BY LATE TONIGHT. VERY LIMITED MOISTURE WITH THIS SYSTEM...HOWEVER THE COMBINATION OF STEEP LAPSE RATES...8C/KM OR GREATER AND LARGE SCALE ASCENT AHEAD OF SURFACE LOW AND S/WV TROUGH DOES SUPPORT CONVECTIVE POTENTIAL BY THIS EVENING. HIGH CLOUDS CURRENTLY WRN DAKOTAS EXPECTED TO ADVECT EWD AND ALLOW FULL HEATING THIS AFTERNOON. BY LATE AFTERNOON WITH TEMPERATURES INTO THE 70S AND DEWPOINTS MID 40S MINIMAL CINH AND MLCAPES TO 500 J/KG WOULD BE AVAILABLE NWRN SD/SWRN ND. THIS WOULD SUPPORT DEVELOPMENT OF HIGH BASED CONVECTION IN AREA OF BEST LOW LEVEL CONVERGENCE. WHILE THERMODYNAMICS WILL BE MARGINAL...THERE WOULD BE POTENTIAL FOR STRONG WIND GUSTS AND MARGINAL HAIL THIS REGION THRU THE EVENING. STORMS EXPECTED TO BECOME ELEVATED OVERNIGHT AS THEY MOVE ACROSS ND INTO NRN MN WITH STRONG LOW LEVEL JET AND SOME ELEVATED INSTABILITY CONTINUING RISK OF MARGINAL HAIL AS FAR E AS NWRN MN. ...SRN FL... HAVE ADDED LOW PROBS OF HAIL AS AIRMASS REMAINS UNSTABLE WITH RELATIVELY STEEP MID LEVEL LAPSE RATES. SHEAR LESS THAN 25 KTS SUPPORT MULTI-CELLS WITH STRONGER UPDRAFTS SUPPORTING SOME HAIL POTENTIAL UNTIL THIS EVENING. ..HALES/GRAMS.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 19:48:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 15:48:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101945 SWODY1 SPC AC 101944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT MON APR 10 2006 VALID 102000Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NRN HIGH PLAINS THROUGH NRN MN... MOISTURE REMAINS LIMITED OVER THE NRN HIGH PLAINS WITH DEWPOINTS GENERALLY IN THE UPPER 30S TO AROUND 40. STEEP MID LEVEL LAPSE RATES AND COLD MID LEVEL TEMPERATURES ASSOCIATED WITH SHORTWAVE TROUGH ADVANCING NEWD THROUGH THE NRN ROCKIES EXIST ABOVE THE MODEST LOW LEVEL MOISTURE. THIS IN CONJUNCTION WITH STRONG SURFACE HEATING WILL CONTRIBUTE TO MLCAPE ON THE ORDER OF 500 TO 800 J/KG ACROSS PARTS OF SERN MT...NWRN SD AND SWRN ND. AS THE SHORTWAVE TROUGH LIFTS NEWD THIS AFTERNOON...A COLD FRONT WILL ADVANCE EWD INTO THE NRN HIGH PLAINS. THE ATMOSPHERE IS STILL CAPPED IN MUCH OF THIS REGION AS OF MID AFTERNOON. HOWEVER...HEATING AND BOUNDARY LAYER MIXING AS WELL AS LARGE SCALE ASCENT ACCOMPANYING THE SHORTWAVE TROUGH SHOULD CONTRIBUTE TO HIGH BASED THUNDERSTORMS. VERTICAL SHEAR SUPPORTIVE OF UPDRAFT ROTATION AND STEEP LAPSE RATES WILL PROMOTE A THREAT FOR HAIL. STEEP LOW LEVEL LAPSE RATES AND DEEP MIXED BOUNDARY LAYERS ALSO SUGGEST ISOLATED STRONG WIND GUSTS MAY ACCOMPANY SOME STORMS THROUGH EARLY EVENING. OTHER STORMS MAY DEVELOP FARTHER NE ACROSS NRN ND INTO NRN MN LATER TONIGHT IN ZONE OF STRENGTHENING WARM ADVECTION WITH A THREAT OF ISOLATED MARGINALLY SEVERE HAIL. LOW LEVEL MOISTURE AND INSTABILITY DO NOT APPEAR SUFFICIENT TO WARRANT MORE THAN LOW PROBABILITIES. ...SRN FL... ISOLATED MARGINALLY SEVERE HAIL AND STRONG WIND GUSTS ASSOCIATED WITH MULTICELL STORMS REMAIN POSSIBLE OVER THE EXTREME SRN TIP OF FL INTO THE FL KEYS THIS AFTERNOON. MOST OF THIS AREA IS IN THE PROCESS OF BEING OVERTURNED...AND THE THREAT SHOULD DIMINISH WITHIN THE NEXT 1 TO 2 HOURS. ..DIAL.. 04/10/2006  From SwoDy1 at goshenarc.org Tue Apr 11 00:42:12 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 20:42:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110039 SWODY1 SPC AC 110037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0737 PM CDT MON APR 10 2006 VALID 110100Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...ND INTO NRN MN... RECENT TRENDS IN LIGHTNING DATA INDICATE TSTMS INCREASING IN COVERAGE ACROSS WRN ND INTO FAR NWRN SD IN ADVANCE OF SHORT WAVE TROUGH LIFTING NEWD THROUGH WY INTO SERN MT. THIS ACTIVITY IS OCCURRING ALONG A COLD FRONT OR INVERTED TROUGH EXTENDING FROM NEAR THE MT/ND BORDER SEWD TO LOW PRESSURE OVER N-CNTRL SD. DESPITE RELATIVELY DRY BOUNDARY-LAYER CONDITIONS...DAYTIME HEATING COUPLED WITH HEIGHT FALLS AHEAD OF AFOREMENTIONED SHORT WAVE TROUGH HAVE CONTRIBUTED TO THE DEVELOPMENT OF STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY /REF. 00Z RAP SOUNDING/. THIS ACTIVITY WILL LIKELY PERSIST THROUGH THE EVENING ACROSS WRN AND CNTRL ND WITH SOME POTENTIAL FOR LOCALLY STRONG WIND GUSTS AND/OR MARGINALLY SEVERE HAIL. FARTHER TO THE E...00Z ABR SOUNDING SHOWED A WELL DEFINED ELEVATED MIXED LAYER WITH A STRONG CAP AT THE BASE OF THIS FEATURE. GIVEN THAT BOUNDARY-LAYER WILL SLOWLY COOL OVERNIGHT...DEEP MOIST CONVECTION APPEARS UNLIKELY S OF SURFACE LOW ALONG COLD FRONT INTO CNTRL SD. BETTER NOCTURNAL POTENTIAL APPEARS TO BE N OF WARM FRONT /CURRENTLY EXTENDING FROM THE SURFACE LOW EWD THROUGH SERN ND INTO WRN LAKE SUPERIOR/ WHERE INCREASING LOW-LEVEL WAA MAY SUPPORT ELEVATED TSTM DEVELOPMENT. GIVEN THE PRESENCE OF THE STEEP MID-LEVEL LAPSE RATES OBSERVED ON THE 00Z SOUNDINGS...THREAT FOR SOME MARGINALLY SEVERE HAIL WILL EXIST FROM N-CNTRL/NERN ND EWD ACROSS NRN MN OVERNIGHT. ..MEAD.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 05:59:37 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 01:59:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110556 SWODY1 SPC AC 110555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE APR 11 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER THE MID MO VALLEY... ...SYNOPSIS... SHORT WAVE TROUGH NOW MOVING THROUGH THE LOWER CO VALLEY WILL CONTINUE NEWD TODAY INTO THE CNTRL PLAINS...AND EVENTUALLY INTO THE MIDWEST TONIGHT. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH LEAD DISTURBANCE OVER THE DAKOTAS WILL DEVELOP NEWD INTO ONTARIO WITH SECONDARY CYCLOGENESIS FORECAST ALONG TRAILING COLD FRONT OVER NRN KS. THIS SECONDARY LOW WILL THEN RAPIDLY DEVELOP NEWD INTO THE WRN GREAT LAKES BY WEDNESDAY MORNING. ...MID MO VALLEY... 11/00Z REGIONAL SOUNDINGS INDICATED THAT LOW-LEVEL MOISTURE REMAINS QUITE LIMITED NWD THROUGH THE GREAT PLAINS WITH THE PRESENCE OF A WELL DEFINED ELEVATED MIXED LAYER /EML/ AND ASSOCIATED STRONG CAP OVER THE LOWER PLAINS. PERSISTENT...STRONG SLY LOW-LEVEL FLOW AHEAD OF THE SECONDARY LOW AND ASSOCIATED FRONT WILL ALLOW FOR SOME INCREASE IN BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA WITH AFTERNOON DEWPOINTS IN THE UPPER 40S TO AROUND 50 F. WHEN COUPLED WITH DAYTIME HEATING...PRE-FRONTAL AIR MASS IS EXPECTED TO BECOME WEAKLY TO MODERATELY UNSTABLE WITH SBCAPES OF 500-1000 J/KG. STRONG CAPPING WILL LIKELY SUPPRESS SURFACE-BASED STORM DEVELOPMENT ACROSS SLIGHT RISK AREA THROUGH MUCH OF THE AFTERNOON...WITH INITIAL STORMS FORMING FARTHER TO THE N OVER MN. HOWEVER...SUSTAINED LOW-LEVEL CONVERGENCE COMBINED WITH INCREASING HEIGHT FALLS/FORCING AHEAD OF APPROACHING SHORTWAVE TROUGH SHOULD SUPPORT SWWD DEVELOPMENT INTO ERN NEB/WRN IA PERHAPS INTO N-CNTRL/NERN KS. FORECAST SOUNDINGS INDICATE SOME LOW-LEVEL HODOGRAPH CURVATURE WITH 40-50 KTS OF WSWLY MID-LEVEL FLOW WHICH WILL BE SUPPORTIVE OF A FEW ORGANIZED/ROTATING STORMS. GIVEN THE PRESENCE OF THE EML AND RESULTANT STEEP-LAPSE RATES...SEVERE HAIL APPEARS LIKELY WITH THE STRONGEST STORMS...IN ADDITION TO ISOLATED STRONG WIND GUSTS. STRENGTHENING LOW-LEVEL WAA SHOULD SUSTAIN STORM CLUSTERS OR A MCS OVERNIGHT EWD ACROSS IA/SRN MN WITH A CONTINUING POTENTIAL FOR GUSTY WINDS AND PERHAPS SOME MARGINALLY SEVERE HAIL. ..MEAD/CROSBIE.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 12:20:01 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 08:20:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111217 SWODY1 SPC AC 111215 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0715 AM CDT TUE APR 11 2006 VALID 111300Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF NEB...KS...IA...AND MO.... ...MO VALLEY... STRONG SHORTWAVE TROUGH SHOWN ON MORNING WATER VAPOR IMAGERY OVER CO IS FORECAST TO MOVE EASTWARD INTO THE CENTRAL PLAINS STATES THIS AFTERNOON. SURFACE LOW ASSOCIATED WITH THIS TROUGH WILL TRACK FROM SOUTHWEST NEB ACROSS IA...WITH COLD FRONT SWEEPING SOUTHWARD INTO KS THIS EVENING. STRONG SOUTHERLY LOW LEVEL WINDS IN WARM SECTOR OF LOW WILL MAINTAIN SURFACE DEWPOINTS IN THE UPPER 40S TO LOWER 50S AHEAD OF LOW...WHERE DEEP-MIXED BOUNDARY LAYER IS FORECAST TO DEVELOP. AFTERNOON MAX MLCAPE VALUES ARE EXPECTED TO REMAIN BELOW 1000 J/KG...WITH STRONG CAPPING INVERSION SHOWN ON MORNING SOUNDINGS LIMITING CONVECTION MOST OF THE DAY. LARGE SCALE FORCING WILL OVERSPREAD PARTS OF NEB/KS/IA/MO DURING THE AFTERNOON...EVENTUALLY ELIMINATING THE CAP AND ALLOWING ISOLATED THUNDERSTORM DEVELOPMENT NEAR SURFACE LOW. FORECAST SOUNDINGS IN THIS REGION SUGGEST FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/SUPERCELL STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. STORMS WILL LIKELY REMAIN HIGH-BASED AND ISOLATED DUE TO MINIMAL INSTABILITY AND CAPPING EFFECTS. ACTIVITY IS FORECAST TO MOVE FROM EASTERN NEB/NERN KS ACROSS NORTHWEST MO AND MUCH OF IA DURING THE EVENING...WITH A SLOW WEAKENING TREND AFTER DARK. ..HART.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 16:34:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 12:34:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111618 SWODY1 SPC AC 111617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CDT TUE APR 11 2006 VALID 111630Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OF THE MID MO RIVER VALLEY... ...CENTRAL PLAINS... SIGNIFICANT MID/UPPER LEVEL TROUGH CONTINUES TO EJECT ENEWD INTO THE CENTRAL HIGH PLAINS THIS MORNING. ACCOMPANYING 50-60 KT WSWLY MID LEVEL JET WILL OVERSPREAD MUCH OF KS AND NOSE ACROSS THE MO RIVER VALLEY EARLY THIS EVENING. THOUGH LARGE SCALE ASCENT WILL BE QUITE IMPRESSIVE WITH THIS SYSTEM...PRIMARY NEGATIVE FOR SEVERE THUNDERSTORMS REMAINS THE LIMITED BOUNDARY LAYER MOISTURE ACROSS THE REGION. MORNING ANALYSES CONTINUE TO INDICATE SFC DEW POINTS AOB 50F FROM FAR NRN OK NNEWD INTO ERN KS/SERN NEB...WITH 55+F DEW POINTS REMAINING SOUTH OF THE RED RIVER. 12Z MODELS ARE NOT CONSISTENT WITH LATE AFTERNOON/EARLY EVENING SFC DEW POINT FORECASTS. THE RUC DEEPLY MIXES/DRIES THE BOUNDARY LAYER WITH SUB-40F DEW POINTS LATER TODAY WHILE THE NAM DEVELOPS SURFACE DEW POINTS 10 DEGREES HIGHER. RESULTANT FORECAST MLCAPE VARIES FROM NEAR ZERO TO AROUND 1000 J/KG. ATTM...EXPECT SFC DEW POINTS AROUND 50F AND MLCAPE OF 500-750 J/KG AHEAD OF DEEPENING SURFACE LOW AND SEWD MOVING COLD FRONT LATER TODAY. GIVEN THE LIMITED INSTABILITY AND EXPECTED CAPPING...INITIATION WILL LIKELY OCCUR LATE IN THE DAY/EARLY THIS EVENING ALONG NOSE OF STRONGEST ASCENT NEAR THE KS/NEB BORDER. DEVELOPMENT SHOULD THEN SPREAD ENEWD AND POSSIBLY BUILD SWD ALONG THE COLD FRONT THROUGH THE MID/LATE EVENING. EFFECTIVE SHEAR IS FORECAST TO REMAIN QUITE STRONG...DESPITE THE HIGH-BASED NATURE OF THE CONVECTION...AND SUPPORT STORM-SCALE ORGANIZATION INTO SMALL LINES/SUPERCELLS. DAMAGING WINDS AND ISOLATED LARGE WILL BE PRIMARY SEVERE THREATS THROUGH THE EARLY EVENING SHOULD STORMS DEVELOP...WITH SEVERE POTENTIAL DIMINISHING AS BOUNDARY LAYER COOLS/DECOUPLES AFTER DARK. ..EVANS/JEWELL.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 19:49:40 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 15:49:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111946 SWODY1 SPC AC 111944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT TUE APR 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO VLY EWD INTO THE UPPER MS VLY... UPPER LEVEL DRY SLOT ASSOCIATED WITH THE CNTRL PLAINS SHORTWAVE TROUGH CONTINUES TO SURGE NWD THROUGH THE MID-MO VLY THIS AFTN. BENEATH THIS DRY SLOT...BOUNDARY LAYER MOISTURE HAS MIXED OUT WITH MID-UPPER 40S SFC DEW POINTS COMMON ACROSS NRN KS AND CNTRL NEB...LIMITING POTENTIAL INSTABILITY AHEAD OF THE PRE-FRONTAL TROUGH. SFC LOW OVER ECNTRL NEB SHOULD MOVE NEWD INTO MN THIS EVENING IN TANDEM WITH THE UPPER WAVE. STRONG LOW/MID-LEVEL FRONTOGENESIS OCCURRING ACROSS WRN NEB WILL TRANSLATE ENEWD ACROSS THE MO RVR LATE THIS AFTN AND INTO THE UPPER MS VLY TONIGHT...EVENTUALLY CATCHING THE PRE-FRONTAL TROUGH. GIVEN THE LIMITED INSTABILITY AND CAPPING...TSTMS WILL LIKELY BE CONFINED TO THE ZONE OF STRONGEST ASCENT/FRONTOGENESIS. THIS SCENARIO ALREADY APPEARS TO BE PLAYING OUT ACROSS CNTRL NEB WHERE VSBL SATL SHOWS ENHANCED CONVECTION WITH VIRGA BEING REPORTED VCNTY KLBF. TSTMS MAY BEGIN TO GROW STRONGER WHEN THEY APPROACH THE PRE-FRONTAL TROUGH ACROSS THE MID-MO VLY LATER THIS AFTN WHERE BOUNDARY LAYER MSTR MAY BE SLIGHTLY HIGHER /MLCAPES 250 J PER KG/ AND CINH WEAKER. BUT...THE STORMS SHOULD REMAIN HIGH-BASED ...WITH A NEARLY DRY-ADIABATIC PROFILE TO CLOUD BASE BEFORE THE PRIMARY COLD FRONT UNDERCUTS THE STORMS. THUS...ISOLD DAMAGING WINDS MAY OCCUR LATE THIS AFTN/EVE...BUT PROSPECTS FOR WIDESPREAD SEVERE TSTMS IS NOT ANTICIPATED. TSTMS WILL MOVE ENEWD ACROSS THE UPPER MS VLY OVERNIGHT. ..RACY.. 04/11/2006  From SwoDy1 at goshenarc.org Wed Apr 12 00:47:50 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 20:47:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120044 SWODY1 SPC AC 120043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0743 PM CDT TUE APR 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO VLY NEWD INTO THE UPPER MS VLY... HIGH-BASED TSTMS INITIATED LATE THIS AFTN ACROSS SERN NEB...ERN KS AND SWRN IA ALONG A PRE-FRONTAL TROUGH. THIS REGION EXPERIENCED THE STRONGEST HEATING BENEATH UPPER LEVEL DRY SLOT AND WITHIN EXIT REGION OF A 70-80 KT H5 JET STREAK. 00Z OMAHA SOUNDING EXHIBITED A DEEPLY MIXED BOUNDARY LAYER WITH AROUND 400-500 J/KG MLCAPE. THE STEEP LAPSE RATE ENVIRONMENT...FAVORABLE VERTICAL SHEAR OF 40-50 KTS AND DRY SUB-CLOUD LAYER HAS BEEN SUFFICIENT FOR A FEW MARGINALLY SEVERE HAIL/WIND GUSTS. THE SYNOPTIC COLD FRONT SHOULD STRENGTHEN AND PROGRESS EWD INTO THE UPPER MS VLY OVERNIGHT AS THE UPPER LEVEL JET STREAK/STRONGER LARGE SCALE ASCENT TRANSLATES ENEWD. THE BROKEN LINE OF TSTMS WILL CONTINUE TO EXPAND ENEWD INTO/ACROSS EXTREME NRN MO AND CNTRL IA THIS EVENING AND INTO THE UPPER MS VLY OVERNIGHT. THOUGH TSTMS WILL BE LIKELY ALONG/IMMEDIATELY BEHIND THE FRONT...THE ISOLD SEVERE THREATS SHOULD DIMINISH AS THE STORMS MOVE BEYOND THE LOW-LEVEL THERMAL RIDGE AXIS. ..RACY.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 05:25:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 01:25:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120522 SWODY1 SPC AC 120520 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 AM CDT WED APR 12 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WELL-DEFINED SHORT WAVE TROUGH CURRENTLY MOVING THROUGH THE MIDWEST WILL CONTINUE ENEWD THROUGH THE GREAT LAKES AND OH VALLEY TODAY...EVENTUALLY PHASING WITH FASTER NRN STREAM DISTURBANCE OVER THE NERN STATES TONIGHT. IN THE LOW-LEVELS...SURFACE LOW INITIALLY OVER THE UP OF MI WILL RAPIDLY DEVELOP NEWD INTO QUEBEC WHILE ASSOCIATED COLD FRONT PUSHES EWD THROUGH THE UPPER OH VALLEY INTO WRN NEW ENGLAND. THE TRAILING PORTION OF THIS FRONT WILL MOVE MORE SLOWLY SEWD PRIOR TO STALLING AND UNDERGOING FRONTOLYSIS S OF THE OH RIVER. THIS BOUNDARY WILL ALSO BECOME PROGRESSIVELY ILL-DEFINED WITH TIME OVER THE CNTRL AND SRN PLAINS WITH THE MAIN BAROCLINIC ZONE BECOMING RE-ESTABLISHED FARTHER TO THE N OWING TO STRENGTHENING LEE TROUGH OVER THE NRN HIGH PLAINS. ...OH VALLEY... 12/00Z REGIONAL SOUNDINGS CONTINUE TO INDICATE THAT LOW-LEVEL MOISTURE REMAINS LIMITED ACROSS THE ERN PLAINS AND MS VALLEY WITH UPSTREAM...MEAN MIXING RATIOS COMMONLY BETWEEN 7-9 G/KG. MOREOVER...ONGOING TSTMS OVER IA HAVE LIKELY PROCESSED THE PLUME OF STEEP MID-LEVEL LAPSE RATES WHICH PRECEEDED THE SHORT WAVE TROUGH INTO THE PLAINS. THIS MODEST LOW-LEVEL MOISTURE COUPLED WITH A TENDENCY FOR WEAKER MID-LEVEL LAPSE RATES WILL LIKELY LIMIT A MORE ORGANIZED SEVERE THREAT LATER TODAY ACROSS REGION. A PRE-FRONTAL CLUSTER OF TSTMS SHOULD BE ONGOING AT THE START OF THE FORECAST PERIOD OVER THE MIDWEST...WITH ACTIVITY CONTINUING EWD THROUGH THE SRN GREAT LAKES AND OH VALLEY TODAY. NO SEVERE WEATHER IS EXPECTED WITH THESE STORMS OWING TO THE WEAK INSTABILITY. MORE VIGOROUS TSTM DEVELOPMENT IS ANTICIPATED BY MID TO LATE AFTERNOON ALONG FRONT OVER ERN IND OR OH WITHIN MARGINALLY UNSTABLE ENVIRONMENT CHARACTERIZED BY SBCAPES OF AROUND 500 J/KG. SUBSEQUENT STORM DEVELOPMENT WILL BE POSSIBLE SWWD ALONG FRONT NEAR OR S OF THE OH RIVER FROM LATE AFTERNOON INTO EARLY EVENING. FORECAST SHEAR PROFILES ARE EXPECTED TO BE QUITE SUPPORTIVE OF ORGANIZED/ROTATING STORMS WITH SWLY SURFACE WINDS VEERING TO WNWLY AT 50 KTS IN THE MID-LEVELS. WHILE THE MOST INTENSE STORMS WILL BE CAPABLE OF LOCALLY STRONG WIND GUSTS AND SOME MARGINALLY SEVERE HAIL...A MORE SUBSTANTIAL SEVERE WEATHER THREAT WILL LIKELY BE LIMITED BY THE WEAK INSTABILITY. ..MEAD/TAYLOR.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 12:33:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 08:33:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121230 SWODY1 SPC AC 121228 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0728 AM CDT WED APR 12 2006 VALID 121300Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY EVENING ACROSS PARTS OF LOWER MI AND OH.... ...GREAT LAKES/OH VALLEY... LATEST SATELLITE IMAGERY SHOWS VIGOROUS UPPER SHORTWAVE TROUGH OVER WI/IL. THIS FEATURE WILL MOVE EASTWARD ACROSS THE GREAT LAKES REGION AND UPPER OH VALLEY. MORNING SURFACE ANALYSIS INDICATES A SURFACE LOW OVER UPPER MI...WITH TRAILING COLD FRONT EXTENDING ACROSS WI...CENTRAL IL...AND CENTRAL MO. MULTIPLE BANDS OF PRE-FRONTAL CONVECTION ARE NOTED AHEAD OF FRONT ACROSS THE OH VALLEY. THIS ACTIVITY IS EXPECTED TO MOVE EASTWARD AND WEAKEN...ALLOWING PORTIONS OF MI/IND/OH TO HEAT SUBSTANTIALLY THROUGH THE DAY. SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT WILL TRANSPORT MOISTURE NORTHWARD INTO THIS REGION WITH AFTERNOON DEWPOINTS IN THE UPPER 40S TO LOWER 50S. PRESENT INDICATIONS ARE THAT THUNDERSTORMS WILL RE-DEVELOP BY EARLY AFTERNOON ALONG COLD FRONT OVER SOUTHERN LOWER MI...EASTERN IND...AND WESTERN OH. THIS ACTIVITY SHOULD SPREAD EASTWARD ACROSS OH AND INTO PARTS OF WESTERN PA/NORTHWESTERN WV BY EARLY EVENING. MODEL FORECAST SOUNDINGS ACROSS THIS REGION SHOW VERY STRONG WESTERLY WIND FIELDS ALOFT...COUPLED WITH STEEP LAPSE RATES AND AT LEAST MARGINAL INSTABILITY. THIS APPEARS FAVORABLE FOR A RISK OF ISOLATED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. STORMS SHOULD WEAKEN AS THEY MOVE INTO INCREASINGLY STABLE AIR MASS OVER PA/WV. ..HART/TAYLOR.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 16:12:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 12:12:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121603 SWODY1 SPC AC 121601 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CDT WED APR 12 2006 VALID 121630Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF LOWER MI... MUCH OF OH AND NWRN PA... ...GREAT LAKES/OHIO VALLEY... PRONOUNCED LOW/MID LEVEL TROUGH EVIDENCED BY CYCLONIC SWIRL IN VSB CLOUD PATTERN MOVING ACROSS SRN LM INTO WRN LWR MI. COLD FRONT MOVING INTO WRN LM TRAILS SWWD ACROSS NRN IND INTO NRN OK. CURRENT ELEVATED CONVECTION DRIVEN BY WARM ADVECTION AND LARGE SCALE ASCENT AHEAD OF TROUGH CONTINUES EWD ACROSS NRN OH WITH SOME CLEARING IN ITS WAKE. HEATING AHEAD OF COLD FRONT INTO WRN OH DURING AFTERNOON WILL STEEPEN LAPSE RATES WHICH ALONG WITH INCREASE IN LOW LEVEL MOISTURE PROVIDES FOR DEVELOPMENT OF MODEST INSTABILITY. NAM APPEARS TOO AGGRESSIVE ON LOW LEVEL MOISTURE WITH THE RUC MORE REASONABLE AS DEWPONTS RISE INTO THE MID 50S ACROSS OH BY MID/LATE AFTERNOON AHEAD OF FRONT. BY MID AFTERNOON WITH SURFACE TEMPERATURES WARMING INTO THE MID 70S AND DEWPOINTS INTO MID 50S...MLCAPES WILL RANGE UPWARDS AHEAD OF COLD FRONT TO POSSIBLY 1000 J/KG CENTRAL OH. FOECASTED 30KT OF LOW LEVEL SHEAR AND DEEPLY MIXED BOUNDARY LAYER...THUNDERSTORMS SHOULD DEVELOP BY MID AFTERNOON FROM SERN CORNER MI SWD INTO WRN OH WITH POTENTIAL OF DAMAGING WINDS AND MARGINALLY SEVERE HAIL. STORMS SHOULD EVOLVE INTO A LINEAR MODE QUICKLY GIVEN LIMITED CAPE AND STRONG SHEAR. POTENTIAL OF DAMAGING WINDS SHOULD DECREASE EWD THIS EVENING AS STORMS ENCOUNTER DECREASING INSTABILITY WRN PA. ..HALES/JEWELL.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 20:01:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 16:01:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121958 SWODY1 SPC AC 121956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT WED APR 12 2006 VALID 122000Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ... ...NRN/CENTRAL OH INTO NWRN PA... AREA OF SHALLOW CONVECTION CONTINUES TO INTENSIFY AT 20Z INTO FAR SWRN ONTARIO AHEAD OF STRONG UPPER SYSTEM AND ASSOCIATED SURFACE COLD FRONT. INSTABILITY HAS REMAINED MINIMAL TODAY AHEAD OF THIS FRONT WITH SURFACE DEW POINTS IN THE LOWER 50S AND SBCAPE AOB 500 J/KG. HOWEVER...CONTINUED HEATING AND SMALL INCREASES IN SURFACE DEW POINTS INTO NERN OH SHOULD ALLOW ACTIVITY TO DEVELOP GRADUALLY SWD ALONG THE FRONT ACROSS NRN OH THROUGH THE EVENING. SHEAR REMAINS QUITE STRONG...DESPITE VEERED/SWLY SURFACE WINDS...AND SHOULD SUPPORT ORGANIZATION INTO SMALL LINES OR LOW-TOPPED SUPERCELLS. WIND DAMAGE AND MARGINALLY SEVERE HAIL SHOULD BE PRIMARY SEVERE THREATS AS THIS HIGH-BASED ACTIVITY MOVES ENEWD THROUGH THE EARLY TO MID EVENING. AN ISOLATED TORNADO WILL ALSO REMAIN POSSIBLE... ESPECIALLY NEAR LAKE ERIE WHERE LOW LEVEL HODOGRAPHS REMAIN LARGE. ...NRN AR... MODEST SURFACE CONVERGENCE CONTINUES ALONG STALLED SURFACE FRONT EXTENDING E-W ACROSS NRN AR/FAR SRN MO THIS AFTERNOON. SOUTH OF THIS BOUNDARY MLCAPE HAS INCREASED TO NEAR 1000 J/KG WITH WEAK CAP.. COMBINATION OF WHICH IS SUPPORTING ISOLATED THUNDERSTORM DEVELOPMENT. FORECAST SOUNDINGS REVEAL EFFECTIVE BULK-SHEAR OF 35 KT...MARGINALLY SUPPORTIVE OF SUPERCELLS WITHIN THIS AMOUNT OF INSTABILITY. THUS...STRONGER STORMS MAY BECOME CAPABLE OF ISOLATED/BRIEF DAMAGING WIND AND LARGE HAIL THREAT. ANY SEVERE THREAT SHOULD DIMINISH AFTER DARK. ...NRN MN... ANOTHER STRONG MID/UPPER LEVEL SYSTEM IS WELL DEFINED MOVING ACROSS SERN MANITOBA AND FAR WRN ONTARIO THIS AFTERNOON. COLD AIR ALOFT AND MARGINAL INSTABILITY/STEEP LAPSE RATES MAY SUPPORT HAIL WITH THE STRONGER CORES...THOUGH OVERALL SEVERE THREAT EXPECTED TO REMAIN MINIMAL. ..EVANS.. 04/12/2006  From SwoDy1 at goshenarc.org Thu Apr 13 00:56:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 20:56:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130052 SWODY1 SPC AC 130050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 PM CDT WED APR 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER AIR PATTERN WILL CONTINUE TO FEATURE BROAD AREA OF HIGH HEIGHTS ACROSS S-CENTRAL CONUS...GREAT PLAINS AND CENTRAL/SRN ROCKIES. CUT-OFF UPPER LOW WILL CONTINUE TO MENDER ERRATICALLY OFFSHORE CA. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN ONT AND ERN GREAT LAKES REGION -- IS FCST TO MOVE EWD OVER PORTIONS SWRN QUE AND MID-ATLANTIC REGION OVERNIGHT. ASSOCIATED SFC COLD FRONT IS ANALYZED FROM NWRN NY TO CENTRAL OH...SRN IL...SRN MO...BECOMING QUASISTATIONARY FROM OZARKS WSWWD ACROSS NRN OK. FRONT SHOULD MOVE EWD ACROSS MID ATLANTIC REGION THROUGH REMAINDER PERIOD...WHILE LIFTING NWD OVER CENTRAL PLAINS AND MO. ...UPPER OH VALLEY REGION... LINE OF SCATTERED TSTMS -- SOME OF WHICH REMAIN AT LEAST MARGINALLY SEVERE...SHOULD CONTINUE TO MOVE EWD ACROSS REMAINDER SERN OH...WRN PA...AND NRN PANHANDLE OF WV. ACTIVITY FARTHER NE ACROSS WRN UPSTATE NY HAS WEAKENED IN MORE STABLE ENVIRONMENT...A TREND THAT SHOULD SHIFT SWD WITH TIME THROUGH CONVECTIVE BAND. SFC ANALYSIS SHOWS THETAE DECREASING WITH EWD EXTENT ACROSS REGION...ANOTHER TENDENCY THAT WILL CONTINUE THROUGH REMAINDER EVENING...DESPITE NARROW PLUME OF BOUNDARY LAYER MOIST ADVECTION JUST AHEAD OF THIS ACTIVITY. AS RELATIVELY DRY AIR MASS DIABATICALLY COOLS...DECOUPLING SFC LAYER...INFLOW REGION SHOULD BECOME PROGRESSIVELY MORE ELEVATED AND LESS UNSTABLE. THEREFORE...SEVERE POTENTIAL IS EXPECTED TO DIMINISH FROM N TO S...AND WITH TIME. ...NRN AR... ISOLATED CLUSTER OF STRONG TO MARGINALLY SEVERE MULTICELLS IS EVIDENT IN ENVIRONMENT OF WEAK LOW LEVEL FLOW...BUT CONSIDERABLE VEERING OF WINDS WITH HEIGHT. ACTIVITY MAY CONTINUE TO BACKBUILD ALONG WRN EDGE FOR ANOTHER COUPLE HOURS...BEFORE DIMINISHING WITH LOSS OF DIURNAL HEATING IN SFC-BASED INFLOW LAYER. HAIL/GUSTS NEAR SEVERE LEVELS REMAINS POSSIBLE BUT THREAT SHOULD DROP MARKEDLY AFTER ABOUT 13/03Z. ..EDWARDS.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 05:03:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 01:03:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130459 SWODY1 SPC AC 130458 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CDT WED APR 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY REGION TO PORTIONS NRN/WRN OH... ...SYNOPSIS... BASIC SYNOPTIC PATTERN WILL BE DOMINATED BY NEARLY ZONAL NRN STREAM FROM PACIFIC NW TO UPPER GREAT LAKES...HEIGHT FALLS DOWNSTREAM OVER NEW ENGLAND...AND BROAD SWATH OF MID/UPPER LEVEL RIDGING ACROSS MOST OF SRN CONUS. LOW-AMPLITUDE SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER BC AND WA -- IS FCST TO MOVE QUICKLY EWD ALONG AND JUST N OF CANADIAN BORDER...REACHING REGION OF LS NORTH SHORE AND BOUNDARY WATERS OF MN/ONT BY END OF PERIOD. SFC FRONTAL ZONE - NOW MOVING EWD ACROSS OH VALLEY REGION AND NEARLY STATIONARY OVER OZARKS -- IS FCST TO RETREAT/REDEVELOP NEWD ACROSS MID/UPPER MS VALLEY THROUGH THIS PERIOD. WEAK CYCLOGENESIS IS REASONABLY FCST ALONG WRN PORTION OF THIS FRONTAL ZONE -- OVER SRN MN/NRN IA REGION BY 14/00Z. THIS LOW SHOULD SHIFT ESEWD TOWARD SRN LOWER MI OR NWRN OH 12 HOURS THEREAFTER. WEAK COLD FRONT SHOULD EXTEND FROM LOW SWWD ACROSS IA/SERN NEB DURING LATE AFTERNOON. ...UPPER MS VALLEY...UPPER GREAT LAKES REGION... MRGL AND HIGHLY CONDITIONAL SEVERE PROBABILITIES ARE FCST DURING AFTERNOON FROM WARM FRONT SWWD ALONG COLD FRONT. GREATER CONVECTIVE AND SEVERE PROBABILITIES ARE AFTER DARK OVER UPPER MIDWEST...GENERALLY WITHIN ABOUT 250 NM NE OF SFC LOW TRACK. VERTICAL SHEAR PROFILES AND PROGGED BUOYANCY WOULD SUPPORT SUPERCELL THREAT DURING LATE AFTERNOON INVOF SFC LOW...OR JUST E OF LOW ALONG WARM FRONT. HOWEVER...THIS THREAT IS STRONGLY CONDITIONAL BECAUSE OF ANTICIPATED STRONG CAP -- EVEN MORE SO THAN SOME MODEL PROGS INDICATE. ETA/SPECTRAL FCSTS OF SFC DEW POINTS APCHG 70 DEG F ACROSS NWRN MO BY 14/00Z AND ASSOCIATED LARGE CAPE/LI FCSTS APPEAR OVERBLOWN AS WELL...CONSIDERING 1. IMPROBABILITY OF SUCH ROBUST EVAPOTRANSPIRATIVE MOISTENING IN THAT AREA DURING MID-APRIL AND 2. DRY CHARACTER OF AIR MASS IN UPSTREAM BOUNDARY LAYER...PER WELL-MIXED OUN/FWD SOUNDINGS. WHEN COMPARED TO SFC HAND ANALYSIS...13/00Z ETA INITIALIZED 3-6 DEG F TOO HIGH ON SFC DEW POINTS IN UPSTREAM BOUNDARY LAYER...S OF WARM FRONT OVER PORTIONS OK/AR. SPECTRAL BEGAN UP TO 10 DEG F TOO WARM ON SFC DEW POINT IN SAME AREA. IF SFC-BASED CONVECTION DEVELOPS NEAR SFC LOW AND WARM FRONT...BACKED FLOW E OF LOW AND 50-60 KT MIDLEVEL WINDS WOULD CONTRIBUTE TO FAVORABLE KINEMATIC PROFILES...WITH 0-3 KM SRH 200-300 J/KG AND 60-70 KT SFC-MIDLEVEL SHEARS. HOWEVER...SUCH DEVELOPMENT WOULD BE VERY ISOLATED...AND MAY NOT EVEN OCCUR. POTENTIAL FOR BRIEF WINDOW OF LATE AFTERNOON TSTMS MAY BE SOMEWHAT LARGER ALONG TRAILING COLD FRONT OVER IA/SERN NEB...WHERE HEATING/MIXING WILL BE STRONGER. DAMAGING GUSTS AND HAIL ARE POSSIBLE FROM ANY TSTMS THAT FORM...BUT CAPPING WILL LIMIT COVERAGE. STRONG LOW LEVEL MOIST ADVECTION AND ELEVATED WAA ARE EXPECTED AFTER DARK...NE OF SFC WARM FRONT. POTENTIAL IS EXPECTED TO SHIFT ESEWD FROM SRN MN ACROSS NRN INDIANA/SRN LOWER MI OVERNIGHT. EXPECT INCREASING CONVECTIVE COVERAGE IN TUNE WITH INCREASING INFLOW-LAYER MOISTURE CONTENT AND LLJ INCREASING TO 50-60 KT DURING 14/06Z-14/12Z TIME FRAME. 8-9 DEG C/KM MIDLEVEL LAPSE RATES SHOULD SPREAD NEWD OVER AREA AS ELEVATED MIXED-LAYER AIR ADVECTS FROM SRN/CENTRAL PLAINS...CONTRIBUTING TO ELEVATED MUCAPES 1500-2000 J/KG. IN ADDITION...FAVORABLE EFFECTIVE SHEAR PROFILES -- ABOVE RELATIVELY STABLE BOUNDARY LAYER -- WILL SUPPORT ORGANIZED SEVERE RISK WITH LARGE HAIL THE MOST COMMON SEVERE MODE...AND DAMAGING WIND POSSIBLE DESPITE SHALLOW/COOL BOUNDARY LAYER. ...WRN NY...NRN PA... WIDELY SCATTERED TSTMS ARE POSSIBLE DURING AFTERNOON...AMIDST RESIDUAL/POST-FRONTAL SFC MOISTURE AND BOUNDARY LAYER HEATING/MIXING. COLD AIR ALOFT IS EXPECTED INVOF MID/UPPER TROUGH -- E.G. -23 TO -26 DEG C AT 500 MB -- ALONG WITH VERY WEAK SBCINH BY MID-LATE AFTERNOON. BOUNDARY LAYER FLOW IS EXPECTED TO BE WLY...RESTRICTING BOTH VERTICAL SHEAR AND SFC CONVERGENCE...AND BY EXTENSION...LIMITING CONVECTIVE COVERAGE. HOWEVER...CONSIDERING COLD AIR MASS THROUGH MIDTROPOSPHERE...ISOLATED HAIL NEAR SEVERE LEVELS IS POSSIBLE. ..EDWARDS.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 12:55:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 08:55:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131251 SWODY1 SPC AC 131250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT THU APR 13 2006 VALID 131300Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID AND UPPER MS VALLEY... BROAD UPPER RIDGE REMAINS IN PLACE ACROSS THE SOUTHERN PLAINS TODAY...WITH BAND OF MODERATELY STRONG MID/UPPER LEVEL FLOW FROM THE NORTHERN ROCKIES INTO THE GREAT LAKES REGION. SEVERAL WEAK SHORTWAVE TROUGHS ARE EMBEDDED IN THIS FLOW PATTERN. ONE FEATURE EVIDENT IN WATER VAPOR IMAGERY OVER MT IS FORECAST TO TRACK EASTWARD INTO MN BY THIS EVENING. SURFACE LOW IS FORECAST TO DEVELOP OVER SOUTHERN MN BY 14/00Z...WITH WARM FRONT EXTENDING EASTWARD INTO NORTHERN IL/IND. EVOLUTION OF BOUNDARY LAYER SOUTH OF LOW/FRONT WILL BE QUITE COMPLEX...BUT APPEARS FAVORABLE FOR RAPID MOISTENING/DESTABILIZATION THROUGH THE AFTERNOON. MODEL FORECAST DEWPOINT VALUES MAY BE SLIGHTLY OVERDONE...BUT MID 60S VALUES APPEAR REASONABLE. IT APPEARS THAT SUBSIDENCE IN THE CAPPING LAYER...COMBINED WITH INFLUX OF LOW LEVEL MOISTURE FROM THE SOUTHWEST...WILL RESULT IN LOCAL POOLING OF SURFACE DEWPOINTS IN THE MID 60S ACROSS PARTS OF MO/IA. ...MN/WI/IL... PRESENT INDICATIONS ARE THAT ISOLATED STORMS WILL DEVELOP BY LATE AFTERNOON/EARLY EVENING OVER SOUTHEAST MN/SOUTHWEST WI ALONG WARM FRONT. THESE STORMS WILL BE IN A FAVORABLE VERTICAL SHEAR ENVIRONMENT FOR SUPERCELL STRUCTURES CAPABLE OF LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES. THIS ACTIVITY WILL SPREAD EASTWARD INTO PARTS OF NORTHERN IL/IND OVERNIGHT. ...IA/MO/IL/IND/KY/OH... OTHER STORMS ARE POSSIBLE OVER EASTERN IA ALONG TRAILING DRYLINE...WHERE WEAK CAP AND STRONG HEATING WILL OCCUR. THIS ACTIVITY WILL LIKELY SPREAD SOUTHEASTWARD ACROSS NORTHEAST MO/CENTRAL IL DURING THE EVENING WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY DEVELOP UPSCALE INTO AN MCS...SPREADING ACROSS PARTS OF IND AND INTO OH/KY BY 14/12Z. ...NY INTO MID ATLANTIC REGION... MORNING VISIBLE SATELLITE IMAGERY SUGGEST THAT STRONG DAYTIME HEATING WILL OCCUR TODAY FROM CENTRAL/EASTERN NY INTO VA AND NORTHERN NC. THIS REGION IS BENEATH UPPER COLD TROUGH...WITH 500MB TEMPERATURES RANGING FROM -17C OVER NC TO -25 OVER NY. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THIS REGION DURING THE AFTERNOON. STEEP LAPSE RATES AND SUFFICIENT INSTABILITY SUGGEST A THREAT OF HAIL IN STRONGER CELLS. ACTIVITY SHOULD DIMINISH QUICKLY AFTER SUNSET. ..HART/TAYLOR.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 16:38:23 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 12:38:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131631 SWODY1 SPC AC 131629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CDT THU APR 13 2006 VALID 131630Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF THE MID AND UPPER MS VALLEY... ...SYNOPSIS... BROAD RIDGING ACROSS MUCH OF CONUS WITH FAST WESTERLIES EXTENDING EWD ACROSS NRN US INTO WRN GREAT LAKES. FLOW THEN BECOMES WNWLY INTO TROUGH OFF E COAST. MID LEVEL TROUGH ERN GREAT LAKES WILL MOVE ESEWD TO BE OFFSHORE BY THIS EVENING. UPSTREAM...S/WV TROUGH AND MIDLEVEL WIND MAX CURRENTLY NRN PLAINS/CANADIAN BORDER REGION MOVES ACROSS FLAT RIDGE TO WRN GREAT LAKES TONIGHT. CURRENTLY ACTIVE PRESSURE FALLS UPPER MS VALLEY WILL LEAD TO SURFACE LOW DEVELOPMENT ACROSS SRN MN THIS AFTERNOON. WARM FRONTAL ZONE WILL EXTEND FROM SURFACE LOW ESEWD ACROSS WI INTO SRN LWR MI BY THIS EVENING WITH A DRY LINE FROM THE LOW SSWWD THRU ERN NEB INTO CENTRAL KS. SLY LOW LEVEL FLOW IS SPREADING MOISTURE AND INSTABILITY NWD THRU ERN PLAINS AND LOWER MO VALLEY IN ADVANCE OF THIS SYSTEM WITH AIR MASS BECOMING VERY UNSTABLE BY MID AFTERNOON. ...SRN MN/IA ACROSS SRN WI/NRN IL INTO WRN OH... LOW LEVEL MOISTURE SPREADING NEWD THRU ERN PLAINS AND LOWER MO VALLEY COUPLED WITH STEEP LAPSE RATES IN PLACE AND NEARLY FULL HEATING WILL RESULT IN MLCAPES IN EXCESS OF 3000 J/KG DEVELOPING IN WARM SECTOR THIS AFTERNOON. OBSERVED MOISTURE ADVECTION SUPPORTS LOW 60 DEWPOINTS INTO IA THIS AFTERNOON...NOT QUITE AS HIGH AS THE NAM...HOWEVER SUFFICIENT TO DEVELOP THE VERY UNSTABLE AIR MASS. CAP WILL HOLD MUCH OF AFTERNOON IN THE WARM SECTOR...HOWEVER WARM FRONTAL LIFT COULD INITIATE STORMS ACROSS SRN MN INTO WI. STRONG VEERING SHEAR PROFILES AND AVAILABLE THERMODYNAMICS SUPPORT SUPERCELL POTENTIAL...AND WITH SURFACE BASED STORMS...TORNADOES WILL BE POSSIBLE. IN ADDITION VERY LARGE HAIL IS QUITE LIKELY PER SPC HAIL MODEL OUTPUT. DRY LINE WILL ALSO BECOME AN INCREASING CONCERN FOR INITIATION BY EVENING IA SWD INTO NRN MO. AGAIN VERY LARGE HAIL WOULD BE THE PRIMARY THREAT WHILE STORM MODE REMAIN MORE CELLULAR. OVERNIGHT THE CONTINUED AVAILABILITY OF MDT TO VERY UNSTABLE AIR ALONG WITH THE INCREASE AND VEERING LOW LEVEL JET SHOULD FUEL THE DEVELOPMENT OF ONE OR MORE SEVERE MCS'S. INCREASING THREAT OF DAMAGING WINDS ALONG WITH THE LARGE HAIL POTENTIAL WILL SPREAD EWD OVERNIGHT INTO THE OH VALLEY AS THE UPPER WIND MAX/S/WV TROUGH MOVES EWD INTO WRN LAKES. ...NY SWD TO VA... STEEP LAPSE RATES AND STRONG HEATING COUPLED WITH ADEQUATE MOISTURE AND COLD AIR ALOFT WILL SUPPORT SCATTERED THUNDERSTORMS THIS AFTERNOON. LARGE HAIL WOULD BE POSSIBLE WITH THE STRONGEST UPDRAFTS GIVEN THE COLD AIR ALOFT AND STEEP LAPSE RATES. WITH ACTIVITY NOT EXPECTED TO BECOME VERY ORGANIZED AS LOW LEVEL SHEAR GENERALLY WEAK...WILL CONTINUE A LOW SEVERE HAIL AND WIND RISK THRU THE AFTERNOON. ..HALES/JEWELL.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 20:03:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 16:03:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131959 SWODY1 SPC AC 131958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0258 PM CDT THU APR 13 2006 VALID 132000Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST...SRN GREAT LAKES AND OH VALLEY... ...UPPER MIDWEST/OH VALLEY... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SUBTLE SHORTWAVE TROUGH EMBEDDED IN WNW FLOW OVER SRN MN EXTENDING SWWD ACROSS FAR SE SD. THIS FEATURE IS FORECAST TO MOVE QUICKLY ESEWD ACROSS THE REGION LATE THIS AFTERNOON INTO THIS EVENING. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE AND A WEAKENING CAPPING INVERSION WILL PROVIDE SUPPORT FOR CONVECTIVE INITIATION LATE THIS AFTERNOON ACROSS WRN WI AND ERN IA. STORMS SHOULD GRADUALLY EXPAND IN COVERAGE WITH AN MCS DEVELOPING AND MOVING QUICKLY ESEWD ACROSS THE REGION THIS EVENING AND OVERNIGHT. LATEST SFC ANALYSIS CURRENTLY SHOWS A MOIST AXIS WITH SFC DEWPOINTS IN THE 60S F EXTENDING NWD ACROSS MO INTO SRN IA. SLY FLOW WILL CONTINUE MOIST ADVECTION INTO IA AND IL THIS AFTERNOON WITH A STRONG LOW-LEVEL MOISTURE GRADIENT SETTING UP FROM NEAR THE DES MOINES/CEDAR RAPIDS AREA EXTENDING ESEWD TO NEAR SPRINGFIELD IL. ALONG AND SOUTH OF THIS GRADIENT...MODERATE INSTABILITY SHOULD BE IN PLACE WITH MLCAPE VALUES IN THE 2000 TO 3000 J/KG RANGE BY LATE THIS AFTERNOON AND EARLY THIS EVENING. IN ADDITION...WNWLY FLOW ALOFT IS CREATING STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH VERY STEEP LAPSE RATES AND THE MODERATE INSTABILITY SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE STRONGER SUPERCELLS MAY ALSO BE CAPABLE OF PRODUCING VERY LARGE HAIL ESPECIALLY ACROSS CNTRL/ERN IA AND NW IL LATE THIS AFTERNOON WHEN INSTABILITY SHOULD BE MAXIMIZED. IN ADDITION...MODELS FORECAST A 50 KT LOW-LEVEL JET TO EXPAND NWD ACROSS THE REGION WHICH WILL CREATE STRONG LOW-LEVEL SHEAR PROFILES WHICH COMBINED WITH THE MOISTURE ADVECTION SHOULD RESULT IN A TORNADO/WIND DAMAGE THREAT AS SUPERCELLS MOVE ESEWD ACROSS ERN IA INTO NRN AND CNTRL IL AND WRN IND THIS EVENING. IF A LARGE-SCALE BOW ECHO DEVELOPS AS THE NAM CONVECTIVE QPF FIELDS SUGGEST...THEN THE WIND DAMAGE POTENTIAL WOULD LIKELY BE ENHANCED CONTINUING OVERNIGHT AS THE LINEAR MCS TRACKS ESEWD ACROSS IND...NRN KY INTO OH. ..BROYLES.. 04/13/2006  From SwoDy1 at goshenarc.org Fri Apr 14 01:05:49 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 21:05:49 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140102 SWODY1 SPC AC 140100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT THU APR 13 2006 VALID 140100Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY TO WRN WV... ...SYNOPSIS... SYNOPTIC UPPER AIR PATTERN SHOULD REMAIN DOMINATED BY NEARLY ZONAL FLOW ACROSS NRN CONUS...RIDGING AND HIGH HEIGHTS FROM 4-CORNERS REGION TO FL...AND NEARLY CUT-OFF MID/UPPER LEVEL LOW OFFSHORE SRN CA. MOISTURE CHANNEL IMAGERY INDICATES SHORTWAVE TROUGH OVER SERN SK...SWRN MB AND NRN ND. SUBTLE PERTURBATION IS EVIDENT IN MOISTURE CHANNEL IMAGERY AND VWP/PROFILER TIME SERIES OVER CENTRAL IA...A FEATURE WHICH TRACKS BACK TO AT LEAST 13/12Z OVER NERN CO. THIS FEATURE -- NOT DEPICTED IN SPECTRAL BUT EVIDENT IN LATEST RUC/ETA -- SHOULD PHASE WITH NRN STREAM TROUGH TO FORM POSITIVELY TILTED SHORTWAVE THAT WILL MOVE ESEWD ACROSS NRN ONT AND UPPER GREAT LAKES REGION OVERNIGHT. SFC ANALYSIS SHOWS DIFFUSE COLD FRONT MOVING EWD ACROSS MN AND SEWD ACROSS CENTRAL MEB...WITH STRONGER CAA REINFORCEMENT OVER CENTRAL ND AND WRN SD. WAVY DRYLINE MEANDERS FROM S-CENTRAL KS NWD TO SERN NEB...THEN ENEWD ACROSS NRN IA...INTERSECTING WARM FRONT OVER SERN MN. DIFFUSE WARM FRONT SHOULD LIFT NWD ACROSS REMAINDER SERN MN AND MUCH OF WI OVERNIGHT. WEAK SFC CYCLOGENESIS IS POSSIBLE OVERNIGHT ALONG WARM FRONT...ACROSS PORTIONS WI/LM. ERN PORTION WARM FRONT SHOULD MOVE SLOWLY NWD OVER NRN INDIANA...SRN LM AND PERHAPS SWRN LOWER MI. ...IA/MN TO UPPER OH VALLEY... REF WW 178 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR NEAR-TERM INFO ON UPPER MS VALLEY SEVERE POTENTIAL. WEAK IA SHORTWAVE TROUGH CORRESPONDED WELL TO FIELD OF CUMULIFORM CLOUDS THAT EVOLVED INTO CURRENT CENTRAL IA TSTM COMPLEX...ONCE ASSOCIATED FIELD OF LARGE SCALE ASCENT MOVED ATOP STRONGEST BOUNDARY LAYER HEATING AND WEAKEST CINH. THIS FEATURE WILL HELP TO MAINTAIN FAVORABLE LARGE SCALE ENVIRONMENT FOR SEVERE -- BOTH IN TERMS OF DEEP-LAYER SHEAR AND STEEPENED MIDLEVEL LAPSE RATES -- AS IT MOVES ACROSS IL/INDIANA OVERNIGHT. FIELDS OF HIGH-BASED/MIDLEVEL CONVECTION IS EVIDENT IN VIS IMAGERY OVER ERN DAKOTAS AND NWRN WI E OF MSP...EACH OF WHICH HAS PRODUCED A FEW LIGHTNING STRIKES. DAKOTAS ACTIVITY IS ASSOCIATED WITH STRONGEST LARGE SCALE ASCENT AHEAD OF NRN STREAM TROUGH...AND MAY INTENSIFY AS IT MOVES EWD PAST SFC FRONTAL ZONE INTO MN...WITH ACCESS TO SOMEWHAT MORE ROBUST MOISTURE FIELD ABOVE SFC. WRN WI ACTIVITY MAY INCREASE AS BOUNDARY LAYER DECOUPLES AND LLJ STRENGTHENS IN INFLOW SECTOR. ANY OF THESE AREAS OF CONVECTION MAY EVOLVE INTO MCS OVERNIGHT...MOVING SEWD ACROSS GREAT LAKES TOWARD LOWER MI...AND OH/WV REGION. MOST PROBABLE AREA FOR LONG-LIVED MCS EVOLUTION IS OVER ERN IA AND NRN IL...EVOLVING FROM ONGOING MIX OF MULTICELLS AND SUPERCELLS OVER IA. ASSOCIATED POTENTIAL FOR DAMAGING GUSTS AND LARGE HAIL SHOULD EXTEND ESEWD ACROSS INDIANA/OH/WV/WRN PA AS THIS ACTIVITY MOVES THROUGH WRN PORTION OF INCREASINGLY MOIST...45-60 KT LLJ. ..EDWARDS.. 04/14/2006  From SwoDy1 at goshenarc.org Sat Apr 15 01:10:29 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 14 Apr 2006 21:10:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150107 SWODY1 SPC AC 150106 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0806 PM CDT FRI APR 14 2006 VALID 150100Z - 151200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS INDIANA...SWRN OH...N-CENTRAL/NERN KY... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM CENTRAL IL TO WRN VA... ...SYNOPSIS... PROGRESSIVE UPPER AIR PATTERN FEATURES STRONG SHORTWAVE TROUGH THAT WILL MOVE NEWD FROM SRN CA ACROSS 4-CORNERS REGION THROUGH REMANDER PERIOD. SFC ANALYSIS SHOWS WEAK COLD FRONT FROM SWRN LM SWWD ACROSS NWRN MO...S-CENTRAL KS...BECOMING QUASISTATIONARY WSWWD ACROSS NWRN OK INTO WEAK LOW OVER CENTRAL PORTION OK PANHANDLE. OUTFLOW BOUNDARY FROM EARLIER CONVECTIVE COMPLEXES IS EVIDENT FROM NERN IL SEWD NEAR A LINE FROM 35 NE CMI...IND...20 W CVG...45 NNE JKL...CRW. OVERALL THIS BOUNDARY SHOULD MOVE LITTLE THROUGH REMAINDER PERIOD...BUT WILL BE SHUNTED SWD LOCALLY BY INDIVIDUAL TSTM OUTFLOWS. ...IL TO CENTRAL APPALACHIANS... SEVERAL POTENTIALLY TORNADIC SUPERCELLS ARE EXPECTED TO CONTINUE MOVING ESEWD ACROSS THIS CORRIDOR...IN ENVIRONMENT OF FAVORABLE MESOSCALE ENHANCEMENT TO BOTH SHEAR AND BUOYANCY. ANOTHER CLUSTER OF MOSTLY HAIL PRODUCING TSTMS OVER NRN WV AND SWRN PA SHOULD CONTINUE MOVING SEWD TOWARD NRN/WRN VA...SEVERE POTENTIAL GRADUALLY DIMINISHING AS IT ENCOUNTERS PROGRESSIVELY MORE DRY/STABLE INFLOW LAYER. REF WWS 184-188 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST DETAILS OVER THIS REGION. OVERALL...MOST FAVORABLE ZONE FOR SEVERE WILL REMAIN ALONG AND JUST N OF OUTFLOW BOUNDARY BETWEEN CENTRAL/NERN IL AND SWRN OH/NERN KY. MODIFIED SOUNDINGS AND RUC SOUNDINGS INDICATE LIFTED PARCELS WILL REMAIN SFC-BASED OR NEARLY SO INVOF BOUNDARY...WHICH ALSO IS ORIENTED FAVORABLY FOR RIGHTWARD MOTION OFF HODOGRAPH. EXPECT EVAPOTRANSPIRATIVELY BOOSTED SFC DEW POINTS -- LOW-MID 60S F RESULTING FROM EARLIER RAINFALL...AND LOWER LCL ALONG AND N OF BOUNDARY. LCL ALSO SHOULD DROP ALONG AND JUST S OF BOUNDARY IN RELATION TO SFC DIABATIC COOLING THROUGH EVENING HOURS...WHILE THOSE PARCELS REMAIN NEARLY SFC-BASED AS WELL. GREATEST THREAT SHOULD REMAIN E OF WEAK MESOLOW -- ANALYZED ON SFC CHARTS OVER EXTREME E-CENTRAL IL AND NWRN INDIANA ALONG OUTFLOW BOUNDARY. PRECEDING SFC PRESSURE FALLS AND RELATIVELY BACKED FLOW N OF BOUNDARY WILL KEEP 0-1 AND 0-3 KM AGL HODOGRAPHS FAVORABLY ENLARGED...WITH SRH AS HIGH AS 400-600 J/KG THROUGH THOSE LAYERS. 60-70 KT DEEP-LAYER SHEARS ALSO SILL CONTINUE TO SUPPORT SUPERCELL S...AS WELL AS POTENTIAL FOR EVENTUAL BOW ECHO DEVELOPMENT. SOMETIME AROUND 15/06Z...EXPECT PROGRESSIVELY MORE DECOUPLED BOUNDARY LAYER...SOMEWHAT ELEVATED PRIMARY INFLOW LAYER AND RELATED INCREASE IN LLJ TO SUPPORT ONE OR MORE MCS BETWEEN INDIANA AND SRN WV. DAMAGING GUSTS AND OCCASIONAL HAIL WILL BE POSSIBLE DURING SUBSEQUENT LATE NIGHT/EARLY MORNING HOURS. ..EDWARDS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 06:02:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 02:02:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150559 SWODY1 SPC AC 150557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT SAT APR 15 2006 VALID 151200Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS CENTRAL/ERN NEB...PORTIONS WRN/SRN IA...N-CENTRAL/NWRN MO...PORTIONS N-CENTRAL/NERN KS.... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM WRN NEB AND ERN KS TO CENTRAL INDIANA.... ...THERE IS A SLGT RISK OF SVR TSTMS SERN OH...CENTRAL APPALACHIANS TO COASTAL MD/VA/NERN NC.... ...SYNOPSIS... IN MID/UPPER LEVELS...EXPECT PROGRESSIVE SHORTWAVE TRAIN WITHIN LARGER SCALE PATTERN THAT FEATURES CENTRAL CONUS RIDGE...AND TROUGHS OVER NERN PACIFIC AND QUE/NEW ENGLAND REGIONS. MOST CRITICAL DAY-1 SYSTEM WILL BE STRONG TROUGH AND EMBEDDED MIDLEVEL CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER LOWER CO RIVER VALLEY. THIS FEATURE WILL CONTINUE TO MOVE NEWD FROM S-CENTRAL ROCKIES ACROSS CENTRAL PLAINS...DECELERATING LATE IN PERIOD OVER ERN NEB/SRN IA/NERN MO REGION AS IT PENETRATES LARGE SCALE RIDGE POSITION. MEANWHILE...WEAK/LOW-AMPLITUDE SHORTWAVE PERTURBATION NOW INVOF MEAN RIDGE -- OVER SERN SASK/SRN MB -- SHOULD MOVE SEWD ACROSS GREAT LAKES TOWARD DELMARVA REGION BY 16/00-16/06Z TIME FRAME. STRONG SHORTWAVE TROUGH NOW OVER NERN/ERN ONT SHOULD DIG ESEWD ACROSS QUE AND NRN NEW ENGLAND THROUGH PERIOD. AT SFC...QUASISTATIONARY FRONTAL ZONE IS ANALYZED FROM CENTRAL/WRN PORTIONS KS/OK BORDER NEWD ACROSS CENTRAL IL...THEN SEWD OVER CENTRAL VA. PORTION FROM IL-WV IS CONVECTIVELY REINFORCED...DISPLACED SW OF MORE DIFFUSE SYNOPTIC WARM FRONTAL POSITION OVER LOWER GREAT LAKES REGION. THIS BOUNDARY SHOULD REMAIN NEARLY STATIONARY FROM IL THROUGH CENTRAL APPALACHIANS DURING MOST OF PERIOD...WHILE MOVING SWD ACROSS VA. WRN PORTION SHOULD RETREAT NWD AS WARM FRONT ACROSS CENTRAL PLAINS AND MID MS VALLEY...AHEAD OF VIGOROUS CENTRAL PLAINS CYCLOGENESIS. THIS LOW -- NOW WEAKLY EVIDENT OVER SERN CO -- SHOULD DEEPEN CONSIDERABLY AS IT MOVES NEWD TO N-CENTRAL/NERN NEB BY 16/00Z. DURING DAY...BLENDED DRYLINE AND PACIFIC FRONT WILL MOVE EWD ACROSS PORTIONS SRN NEB...WRN/CENTRAL KS AND WRN/CENTRAL OK S OF SFC LOW. ...CENTRAL PLAINS... POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT -- RELATIVELY CONFINED GEOGRAPHICALLY BUT WITH THREAT OF SEVERAL VERY DAMAGING SUPERCELLS -- IS POSSIBLE IN AND NEAR MDT RISK AREA. TORNADOES AND DAMAGING HAIL/GUSTS ARE EXPECTED. PRIMARY CONCERN WILL BE FROM MID-AFTERNOON THROUGH EVENING...THOUGH EARLIEST SFC-BASED SEVERE TSTMS MAY INITIATE DURING EARLY AFTERNOON OVER CENTRAL HIGH PLAINS...JUST AHEAD OF EJECTING SFC CYCLONE. DESTABILIZATION ALOFT SHOULD BE VIGOROUS WITH THIS SYSTEM AS IT APCHS...GIVEN -22 DEG C 50 MB TEMPS OBSERVED IN 15/00Z NKX RAOB...100-120 M/12 HOUR HEIGHT FALLS OBSERVED IN MIDLEVELS FROM THERE NEWD ACROSS NRN AZ...CONSIDERABLE AMOUNT OF THUNDER DETECTED IN PAST FEW HOURS ACROSS SRN NV/UT...AND INTENSE DPVA FCST TO SHIFT ENEWD ACROSS KS/NEB BY 16/00Z. ANY SUPERCELLS DEVELOPING ALONG/AHEAD OF DRYLINE DURING AFTERNOON SHOULD MOVE NEWD OVER KS AND NNEWD TO NNWWD OVER NEB. TORNADO POTENTIAL SHOULD BE GREATEST INVOF WARM FRONT WHERE INDIVIDUAL TSTMS THAT DEVELOPED FARTHER SW HAVE HAD TIME TO MATURE...AND TO ENCOUNTER AREA OF ENHANCED VORTICITY/SRH AND LOWERED LCL CHARACTERIZING BAROCLINIC ZONE. CONVECTIVE COVERAGE SHOULD DIMINISH WITH SWD EXTENT ACROSS KS/OK BECAUSE OF DIMINISHING LOW AND MIDDLE LEVEL FORCING...STRENGTHENING CINH...AND WEAKER MLCAPE RELATED TO MORE VIGOROUS MIXING/DRYING OF MOIST SECTOR BOUNDARY LAYER. LARGE/DAMAGING HAIL...SEVERE GUSTS AND PERHAPS A FEW TORNADOES ARE POSSIBLE FROM ANY TSTMS THAT DO FORM FROM CENTRAL/ERN KS SWD ALONG DRYLINE. HOWEVER...SEVERE POTENTIAL BECOMES MORE STRONGLY CONDITIONAL WITH SWD EXTENT UNTIL THUNDER POTENTIAL GETS TOO LOW TO JUSTIFY SEVERE PROBABILITIES. ...MID MS VALLEY -- ERN MO/IL/INDIANA... ADDITIONAL SEVERE TSTMS MAY DEVELOP DURING AFTERNOON/EVENING FARTHER SE ACROSS WARM FRONT AND ADJACENT MOIST SECTOR...OVER PORTIONS MO/IL. VERTICAL SHEAR PROFILES...WHILE NOT AS INTENSE AS IN ZONE OF STRONG ISALLOBARIC FORCING NEAR SFC LOW -- STILL MAY SUPPORT SEVERE MULTICELLS...AND PERHAPS A FEW HEAVY-PRECIP SUPERCELL/BOW MORPHOLOGIES. MOST FAVORABLE KINEMATIC AND THERMODYNAMIC PROFILES WILL BE INVOF SFC WARM FRONT WHERE BACKED SFC WINDS ENHANCE DEEP-LAYER SHEARS...THOUGH WEAK LOW LEVEL WINDS MAY KEEP BOUNDARY LAYER HODOGRAPHS RELATIVELY SMALL. LITTLE OR NO MID/UPPER LEVEL FORCING IS LIKELY FOR MUCH OF PERIOD...THOUGH CONVECTION MAY BE AIDED BY LOW LEVEL WAA...FRONTAL LIFT AND WEAK CINH RESULTING FROM AFTERNOON INSOLATION. ALTHOUGH MODEL FCST DEW POINTS APPEAR OVERDONE ONCE AGAIN...WELL HEATED/MIXED BOUNDARY LAYERS AND UPPER 50S/LOW 60S DEW POINTS MAY SUPPORT 2000-2500 J/KG MLCAPES FROM 15/21Z-16/00Z. SUPERCELL POTENTIAL MAY INCREASE AFTER DARK OVER CENTRAL/ERN MO AS STRONGER WINDS ALOFT OVERSPREAD AREA AHEAD OF MIDLEVEL LOW. ... CENTRAL APPALACHIANS TO TIDEWATER REGION... CONTINUED POTENTIAL EXISTS THROUGH MUCH OF PERIOD FOR CLUSTERS OF STRONG-SEVERE TSTMS TO FORM INVOF PERSISTENT BAROCLINIC ZONE. MOST PROBABLE SEVERE TSTM THREAT WILL BE FROM AFTERNOON THROUGH EVENING FROM WV THROUGH WRN/CENTRAL VA...SHIFTING ESEWD ACROSS PORTIONS ERN/SRN VA AND NRN NC. STEEP MIDLEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPES POTENTIALLY EXCEEDING 2000 J/KG IN SOME PARTS OF THIS REGION. INVERTED-V THERMODYNAMIC PROFILES IN FCST SOUNDINGS RESULT FROM STRONG HEATING/MIXING OF BOUNDARY LAYER ALONG AND S OF FRONTAL ZONE...CONTRIBUTING TO POTENTIAL FOR BOTH HAIL AND DAMAGING GUSTS TO REACH SFC. ...NERN CONUS... POCKETS OF FAVORABLE SFC HEATING WITH WEAK CINH MAY CONTRIBUTE TO CONVECTIVE POTENTIAL FROM LATE MORNING THROUGH AFTERNOON...WITH SOME HAIL/GUSTS NEAR SEVERE LEVELS POSSIBLE. SFC DEW POINTS MID 50S...ISOLATED NEAR 60 F...ARE POSSIBLE FROM ERN PA ACROSS PORTIONS NJ/SERN NY W OF WARM FRONT THAT WILL BE MOVING EWD OVER THIS REGION. NEARLY UNIDIRECTIONAL WLY-WNWLY WIND PROFILES ARE FCST THROUGH MOST OF TROPOSPHERE. THIS SHOULD LIMIT CONVERGENCE AND OVERALL COVERAGE OF TSTMS...AS WELL AS STRENGTH OF DEEP-LAYER SHEAR. HOWEVER...MID/UPPER FLOW WILL BE ENHANCED S OF ONT/QUE TROUGH...AIDING ORGANIZATION OF ANY SUSTAINED TSTMS THAT DO DEVELOP. ..EDWARDS/GRAMS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 13:11:04 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 09:11:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151307 SWODY1 SPC AC 151305 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0805 AM CDT SAT APR 15 2006 VALID 151300Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID/LWR MO VLYS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEB/NRN KS TO THE MID MS VLY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM OH TO THE MID ATLANTIC CST... ...SYNOPSIS... STRONG UPR IMPULSE NOW OVER CO/NRN NM SHOULD CONTINUE RAPIDLY NE INTO CNTRL NEB BY THIS EVENING...BEFORE DECELERATING AS IT CLOSES OFF OVER IA EARLY SUNDAY. ASSOCIATED LEE LOW NOW OVER NE CO EXPECTED TO TRACK TO NEAR KOFU BY EARLY TONIGHT AS TRAILING PACIFIC COLD FRONT SWEEPS INTO FAR ERN KS. DEEPENING OF NEB LOW SHOULD DRAW BOUNDARY NOW EXTENDING FROM NRN KS INTO CNTRL MO/SRN IL NWD AS A WARM FRONT. AT THE SAME TIME...EXPECT THAT ERN PART OF SAME BOUNDARY WILL DROP S ACROSS THE MID ATLANTIC STATES IN RESPONSE TO GRADUAL INCREASE IN NWLY MID/UPR LEVEL FLOW DOWNSTREAM FROM AMPLIFYING SYSTEM IN THE PLAINS. ...MID/LWR MO VLY... CONDITIONS EXPECTED TO BECOME FAVORABLE FOR SEVERE STORMS OVER A SMALL PART OF THE CNTRL PLNS/LWR MO VLY LATE THIS AFTERNOON INTO TONIGHT AS ABRUPT INCREASE IN ASCENT ASSOCIATED WITH APPROACHING UPR TROUGH OVERSPREADS REGION. COMBINATION OF SURFACE HEATING AND CONVERGENCE ALONG AND AHEAD OF COLD FRONT SHOULD OVERCOME CIN AND SUPPORT STORM DEVELOPMENT BY MIDDAY...MOST LIKELY OVER WRN/CNTRL NEB. DEVELOPMENT SHOULD THEN SPREAD S INTO NRN/NE KS WITH TIME AS HEATING FURTHER DESTABILIZES LWR LAYERS...AND FORCING FOR ASCENT ENCOUNTERS MORE SUBSTANTIAL LOW LEVEL MOISTURE INFLOW. COMPACT NATURE OF EJECTING TROUGH AND ASSOCIATED LATITUDINAL VARIATION OF WIND FIELD WILL RESULT IN A HIGHLY VARIABLE DEEP SHEAR PATTERN WITH SPACE/TIME ACROSS THE CNTRL PLNS/LWR MO VLY. SUFFICE IT TO SAY THAT SHEAR WILL NEVERTHELESS BE SUFFICIENT FOR ORGANIZED STORMS/SUPERCELLS THROUGH THE REGION DURING PERIOD OF EXPECTED CONVECTIVE DEVELOPMENT. BUT TEMPORAL VARIATION OF WIND PROFILES... AND THE RELATIVELY LIMITED MOISTURE SUPPLY AT THE OUTSET...DO SERIOUSLY COMPLICATE FORECAST OF DOMINATE CONVECTIVE MODE. WITH INITIAL LOW TO MID LEVEL ENVIRONMENT EXPECTED TO REMAIN LARGELY UNSATURATED OVER MUCH OF ERN NEB...AND PROSPECTS FOR SUBSTANTIAL LOW LEVEL MOISTENING BETWEEN NOW AND CONVECTIVE INITIATION TIME LOOKING SLIM...EXPECT THAT MAIN SEVERE THREATS WILL BE HIGH WIND AND HAIL FROM ROTATING STORMS ORGANIZED IN SHORT BANDS/CLUSTERS. FARTHER S AND E...POTENTIAL FOR LONG-LIVED/MORE DISCRETE SUPERCELLS APPEARS SOMEWHAT GREATER INVOF WARM FRONT IN EXTREME ERN NEB/WRN IA AND NRN MO. ENHANCED LOW LEVEL SRH COULD YIELD A TORNADO THREAT IN ADDITION TO LARGE HAIL/HIGH WIND. ...MID MS VLY... FARTHER E...OTHER SEVERE TSTMS MAY DEVELOP DURING AFTERNOON/EVENING INVOF WARM FRONT OVER PARTS OF THE MID MS VLY. VERTICAL SHEAR...WHILE NOT AS INTENSE AS NEAR UPR TROUGH...MAY -- STILL SUPPORT SEVERE MULTICELLS AND PERHAPS MARGINAL SUPERCELLS. WEAK LOW LEVEL WINDS SHOULD KEEP SRH RELATIVELY SMALL AND MID/UPR LEVEL FORCING LIKELY WILL REMAIN WEAK. BUT HEATING COULD BOOST MLCAPE TO 2000-2500 J/KG. SUPERCELL POTENTIAL MAY INCREASE AFTER DARK OVER ERN MO/IL AS STRONGER FLOW ALOFT OVERSPREADS AREA AHEAD OF UPR TROUGH. ...OH TO MID ATL CST/TIDEWATER AREA... MODERATE...SLIGHTLY DIFFLUENT...DEEP WNW TO NWLY FLOW WILL PREVAIL FROM THE UPR OH VLY TO THE MID ATLANTIC COAST THROUGH THE PERIOD. SATELLITE SUGGESTS A WEAK IMPULSE NOW CRESTING THE WV MOUNTAINS... WITH A SIMILAR DISTURBANCE UPSTREAM OVER WRN LWR MI. SURFACE FEATURES ARE DIFFUSE OVER THE REGION...WITH ONE BOUNDARY EXTENDING FROM SW OH TO CNTRL NY...AND ANOTHER OF APPARENT CONVECTIVE ORIGIN EXTENDING FROM SRN OH TO TIDEWATER VIRGINIA. WHILE MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP...THEY ARE SUFFICIENT FOR STORMS...ESPECIALLY GIVEN THAT SURFACE HEATING SHOULD BE FAIRLY STRONG FROM CNTRL/SRN OH ESE TO THE MID ATLANTIC COAST. OVERALL PATTERN SUGGESTS THE LIKELIHOOD FOR THE DEVELOPMENT OF SCATTERED BANDS/SMALL CLUSTERS OF MAINLY DIURNAL STORMS THAT WILL HAVE THE POTENTIAL FOR HAIL AND POSSIBLY LOCALLY DAMAGING WIND. ..CORFIDI/GRAMS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 16:34:16 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 12:34:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151630 SWODY1 SPC AC 151628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT SAT APR 15 2006 VALID 151630Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER THE MID MO RIVER VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS TO THE TIDEWATER/MID ATLANTIC COAST... ...PLAINS INTO THE MID MS RIVER VALLEY... WV IMAGERY DEPICTS SIGNIFICANT SYSTEM EJECTING QUICKLY NEWD INTO THE CENTRAL HIGH PLAINS THIS MORNING...WITH SUBSTANTIAL DRYING AND 40+ KT WLY SURFACE WINDS OVER SERN CO SOUTH OF ASSOCIATED SURFACE LOW. LOW CENTER NOW NEAR OGALLALA NEB WILL UNDERGO FURTHER DEEPENING AS IT SHIFTS ENEWD INTO CENTRAL NEB THIS AFTERNOON. MORNING OPERATIONAL MODELS VERY CONSISTENT IN LOCATION OF LARGE SCALE FEATURES ASSOCIATED WITH THIS SYSTEM TODAY AND TONIGHT... WITH VERY FAVORABLE DYNAMIC SET-UP BECOMING ESTABLISHED INTO ERN NEB/ERN KS THIS AFTERNOON. HOWEVER...BOUNDARY LAYER MOISTURE REMAINS QUITE MEAGER AND VERY STRONG CAP REMAINS FIRMLY ESTABLISHED UNDER WELL-MIXED ELEVATED AIR MASS OVER THE PLAINS. OPERATIONAL MODELS CONTINUE TO OVER-FORECAST SURFACE DEW POINTS TODAY. OBSERVED DEW POINTS AT 15Z REQUIRE SUBSTANTIAL INCREASES FROM NON-ADVECTIVE PROCESSES TO REACH THE MID 60S FORECAST BY THE NAM/ETA ACROSS MUCH OF MO...AND UPPER 60F EWD ALONG WARM FRONT TO THE LOWER OH RIVER VALLEY. THE RUC APPEARS MORE REASONABLE IN BRINGING 60F-64F DEW POINTS INTO E-CENTRAL/NERN KS WITH MID 50S F DEW POINTS NWD ACROSS MUCH OF ERN NEB. ATTM...APPEARS STRENGTH OF CAP WILL LIMIT DEVELOPMENT INTO WARM SECTOR UNTIL AFTER 21ZZ. HOWEVER...NEAR 50F SURFACE DEW POINTS SHOULD WRAP NWWD NEAR/AROUND LOW CENTER UNDER MID LEVEL COLD POCKET DURING THE AFTERNOON. SHOULD BOUNDARY LAYER MOISTURE SURVIVE MIXING...STORMS WILL LIKELY DEVELOP DURING THE MID/LATE AFTERNOON INTO WRN/CENTRAL NEB WITHIN STRONG AMBIENT VORTICITY WITH ATTENDANT ISOLATED TORNADO/LARGE HAIL THREAT. PW/S ARE FORECAST TO REMAIN QUITE LOW AND SHOULD SUPPORT LP-SUPERCELLS AND HIGH BASED LINEAR STRUCTURES...INCREASING THE THREAT OF DAMAGING WINDS. THIS ACTIVITY MAY THEN CONSOLIDATE ALONG LEADING OUTFLOW/DEEP ASCENT EWD INTO RELATIVELY GREATER MOISTURE NEAR THE MID MO RIVER VALLEY. SUBSTANTIAL LOW LEVEL SHEAR...ENHANCED BY INTENSE PRESSURE FALLS AHEAD OF ADVANCING LOW CENTER SHOULD ALSO MAINTAIN THE THREAT OF A FEW TORNADOES. FARTHER SOUTH ALONG THE DRY LINE DEVELOPMENT WILL BECOME LESS LIKELY INTO CENTRAL/ERN KS. HOWEVER...SUBSTANTIAL SHEAR AND PRESENCE OF LOWER 60F DEW POINTS/MLCAPE AROUND 2000 J/KG WILL REMAIN FAVORABLE FOR LONG-LIVED SUPERCELLS. AFTER DARK...ONE OR MORE MCSS WILL EVOLVE ALONG NOSE OF STRONG SSWLY LLJ AND OVERSPREAD MUCH OF THE MID/NRN MS RIVER VALLEY. ACTIVITY WILL LIKELY BECOME INCREASINGLY ELEVATED E-NE OF MID MO RIVER VALLEY WITH MAIN THREAT OF LARGE HAIL...THOUGH STRONG ASCENT NEAR WARM FRONT MAY SUSTAIN A NEAR SURFACE-BASED SEVERE THREAT WELL THROUGH THE EVENING INTO NRN MO INTO SERN IA/CENTRAL IL. ...MID MS RIVER VALLEY ACROSS THE OH RIVER VALLEY... LARGE SCALE ASCENT WILL REMAIN WEAK/LACKING OVER MUCH OF THIS REGION TODAY. HOWEVER...AIR MASS WILL BECOME MODERATELY UNSTABLE AND REMAIN UNDER MODEST WNWLY FLOW ALOFT. RIDGING WILL BUILD ACROSS THE MID MS RIVER VALLEY THOUGH THE DAY AHEAD OF PLAINS SYSTEM. HOWEVER...CONVERGENCE NEAR WARM FRONT/RESIDUAL OUTFLOW BOUNDARIES SUGGEST ANY THUNDERSTORM CLUSTER WHICH CAN FORM WILL LIKELY BECOME SEVERE. OVERALL THREAT SHOULD DIMINISH THIS EVENING WITH LOSS OF HEATING. ...CENTRAL APPALACHIANS INTO THE MID ATLANTIC/TIDEWATER... STRONG HEATING AND HIGHER THETA-E AIR MASS FROM ERN WV/PA ACROSS THE DELMARVA AND SRN NJ WILL CONTRIBUTE TO INCREASING DESTABILIZATION THIS AFTERNOON. LARGE SCALE DYNAMIC FORCING FOR ASCENT ACROSS THESE AREAS APPEARS TO REMAIN SOMEWHAT AMBIGUOUS/WEAK BASED ON LATEST WATER VAPOR SATELLITE LOOP AND SHORT-TERM GUIDANCE. HOWEVER...COLD FRONT...NOW DEVELOPING SLOWLY SOUTH FROM OH/PA...AND LEE-TROUGHING EAST OF THE APPALACHIAN FOOTHILLS...SHOULD PROVIDE IMPETUS FOR STORM DEVELOPMENT. BAND OF 60KT NWLY MID LEVEL FLOW AND STEEPENING LOW THROUGH MID LEVEL LAPSE RATES WILL PROMOTE STORM ORGANIZATION AND INTENSIFICATION THROUGH LATE AFTERNOON. STRONG DEEP-LAYER...PRIMARILY UNIDIRECTIONAL...SHEAR INDICATES FAST MOVING STORMS WITH SUPERCELL STRUCTURES POSSIBLE. ACTIVITY MAY BECOME CONCENTRATED NEAR/ALONG LEE-TROUGH/COLD FRONT INTERSECTION FROM SERN PA INTO NRN VA...AND PERHAPS NEAR RESIDUAL/WEAK OUTFLOW BOUNDARY FROM TIP OF DELMARVA PENINSULA WNWWD ACROSS THE TIDEWATER. DAMAGING WIND GUSTS AND HAIL ARE EXPECTED WITH THESE STORMS THROUGH EARLY EVENING WITH SEVERE WEATHER POTENTIAL DIMINISHING RAPIDLY HEREAFTER. ..EVANS/CARBIN/GUYER.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 20:12:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 16:12:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152009 SWODY1 SPC AC 152007 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0307 PM CDT SAT APR 15 2006 VALID 152000Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN NEB...SW IA...NW MO AND FAR NE KS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... ...PLAINS/UPPER MIDWEST... WATER VAPOR IMAGERY SHOWS A VIGOROUS NEGATIVELY-TILTED UPPER-LEVEL TROUGH ENTERING THE PLAINS STATES. A DRY SLOT IS ADVANCING QUICKLY EWD ACROSS KS AND SRN NEB ASSOCIATED WITH A 90 KT MID-LEVEL JET NOSING INTO CNTRL NEB. STORMS ARE CURRENTLY INITIATING AHEAD OF THE DRY SLOT IN ERN KS WHERE A CAPPING INVERSION IS WEAKENING. ADDITIONAL STORMS DEVELOPING IN SCNTRL NEB THIS AFTERNOON SHOULD EXPAND ESEWD ACROSS SERN NEB INTO FAR NW MO. AS THE TROUGH SHIFTS NEWD THROUGH EARLY AFTERNOON...A LARGE MCS SHOULD DEVELOP AND MOVE ENEWD ACROSS ERN NEB...SWRN IA AND FAR NWRN MO. FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR LATE THIS AFTERNOON AND EARLY THIS EVENING SHOW INCREASING INSTABILITY AS A MOIST AXIS WITH SFC DEWPOINTS NEAR 60 F SHIFT NEWD ACROSS THE REGION. IN ADDITION...STRONG VERTICAL SHEAR PROFILES EXIST AND MID-LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN AS THE MID-LEVEL JET PUNCHES INTO THE REGION. THE INSTABILITY AND SHEAR WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. AS DESTABILIZATION CONTINUES AND STORM COVERAGE EXPANDS...THE STRONGER SUPERCELLS SHOULD BE CAPABLE OF VERY LARGE HAIL. IN ADDITION...THE LOW-LEVEL SHEAR PROFILES WILL BECOME INCREASINGLY FAVORABLE FOR A FEW TORNADIC SUPERCELLS BY EARLY EVENING AS A 50 TO 60 KT LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE MODERATE RISK AREA. AS STORM COVERAGE EXPANDS AND A MCS MOVES ACROSS SRN IA AND NRN MO INTO FAR NWRN IL THIS EVENING...A FEW TORNADOES ALONG WITH LARGE HAIL AND WIND DAMAGE WILL CONTINUE TO BE POSSIBLE. THE SEVERE THREAT SHOULD EVENTUALLY BECOME MARGINAL AS THE CONVECTIVE COMPLEX MOVES EWD INTO IND AFTER MIDNIGHT WHERE INSTABILITY WILL BE WEAKER. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... WATER VAPOR IMAGERY CURRENTLY SHOWS A SUBTLE SHORTWAVE TROUGH ACROSS THE OH VALLEY MOVING INTO THE CNTRL APPALACHIAN MTNS. SCATTERED THUNDERSTORM DEVELOPMENT SHOULD CONTINUE TO OCCUR AHEAD OF THIS FEATURE IN THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS THIS AFTERNOON. OBJECTIVE ANALYSIS ACROSS THE REGION SHOW STRONG VERTICAL SHEAR PROFILES...MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. STORM COVERAGE ALONG WITH THE SEVERE POTENTIAL SHOULD DECREASE THIS EVENING AS INSTABILITY WEAKENS AND A SHORTWAVE RIDGE APPROACHES FROM THE WEST. ..BROYLES.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 20:31:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 16:31:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152022 SWODY1 SPC AC 152020 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0320 PM CDT SAT APR 15 2006 VALID 152000Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN NEB...SW IA...NW MO AND FAR NE KS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... CORRECTED TO ADJUST CATEGORICAL AND HAIL LINES ...PLAINS/UPPER MIDWEST... WATER VAPOR IMAGERY SHOWS A VIGOROUS NEGATIVELY-TILTED UPPER-LEVEL TROUGH ENTERING THE PLAINS STATES. A DRY SLOT IS ADVANCING QUICKLY EWD ACROSS KS AND SRN NEB ASSOCIATED WITH A 90 KT MID-LEVEL JET NOSING INTO CNTRL NEB. STORMS ARE CURRENTLY INITIATING AHEAD OF THE DRY SLOT IN ERN KS WHERE A CAPPING INVERSION IS WEAKENING. ADDITIONAL STORMS DEVELOPING IN SCNTRL NEB THIS AFTERNOON SHOULD EXPAND ESEWD ACROSS SERN NEB INTO FAR NW MO. AS THE TROUGH SHIFTS NEWD THROUGH EARLY AFTERNOON...A LARGE MCS SHOULD DEVELOP AND MOVE ENEWD ACROSS ERN NEB...SWRN IA AND FAR NWRN MO. FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR LATE THIS AFTERNOON AND EARLY THIS EVENING SHOW INCREASING INSTABILITY AS A MOIST AXIS WITH SFC DEWPOINTS NEAR 60 F SHIFT NEWD ACROSS THE REGION. IN ADDITION...STRONG VERTICAL SHEAR PROFILES EXIST AND MID-LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN AS THE MID-LEVEL JET PUNCHES INTO THE REGION. THE INSTABILITY AND SHEAR WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. AS DESTABILIZATION CONTINUES AND STORM COVERAGE EXPANDS...THE STRONGER SUPERCELLS SHOULD BE CAPABLE OF VERY LARGE HAIL. IN ADDITION...THE LOW-LEVEL SHEAR PROFILES WILL BECOME INCREASINGLY FAVORABLE FOR A FEW TORNADIC SUPERCELLS BY EARLY EVENING AS A 50 TO 60 KT LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE MODERATE RISK AREA. AS STORM COVERAGE EXPANDS AND A MCS MOVES ACROSS SRN IA AND NRN MO INTO FAR NWRN IL THIS EVENING...A FEW TORNADOES ALONG WITH LARGE HAIL AND WIND DAMAGE WILL CONTINUE TO BE POSSIBLE. THE SEVERE THREAT SHOULD EVENTUALLY BECOME MARGINAL AS THE CONVECTIVE COMPLEX MOVES EWD INTO IND AFTER MIDNIGHT WHERE INSTABILITY WILL BE WEAKER. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... WATER VAPOR IMAGERY CURRENTLY SHOWS A SUBTLE SHORTWAVE TROUGH ACROSS THE OH VALLEY MOVING INTO THE CNTRL APPALACHIAN MTNS. SCATTERED THUNDERSTORM DEVELOPMENT SHOULD CONTINUE TO OCCUR AHEAD OF THIS FEATURE IN THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS THIS AFTERNOON. OBJECTIVE ANALYSIS ACROSS THE REGION SHOW STRONG VERTICAL SHEAR PROFILES...MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. STORM COVERAGE ALONG WITH THE SEVERE POTENTIAL SHOULD DECREASE THIS EVENING AS INSTABILITY WEAKENS AND A SHORTWAVE RIDGE APPROACHES FROM THE WEST. ..BROYLES.. 04/15/2006  From SwoDy1 at goshenarc.org Sun Apr 16 01:09:26 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 21:09:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160105 SWODY1 SPC AC 160104 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0804 PM CDT SAT APR 15 2006 VALID 160100Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID/LOWER MO VALLEY EWD TO IL/WRN IND... ...SYNOPSIS... VIGOROUS MID/UPPER LEVEL CLOSED LOW...CURRENTLY LOCATED OVER CENTRAL NEB/NRN KS...AND WITHIN CENTRAL/SRN PLAINS TROUGH IS EXPECTED TO STOP DEEPENING TONIGHT AS IT TRACKS MORE ELY...REACHING IA/NRN MO BY 12Z SUNDAY. ATTENDANT SURFACE LOW SHOULD ALSO BEGIN A WEAKENING PROCESS...BUT SHOULD REMAIN AOB 990 MB BY SUNDAY MORNING AS IT MOVES EWD INTO IA. SURFACE BOUNDARY EXTENDED ESEWD FROM CENTRAL NEB LOW ACROSS THE MID MS/OH VALLEYS TO SRN VA. WRN EXTENT WILL CONTINUE TO MOVE NWD AS A WARM FRONT REACHING SRN IA AND CENTRAL IL/IND BY END OF PERIOD...WHILE KY PORTION REMAINS NEARLY STATIONARY. ERN EXTENT ACROSS VA EXPECTED TO CONTINUE MOVING SSEWD AS A COLD FRONT INTO NC OVERNIGHT. MEANWHILE...DRY LINE TRAILED SSWWD FROM SERN NEB THROUGH ERN KS/CENTRAL OK INTO NORTH CENTRAL TO SW TX. PACIFIC COLD FRONT WILL CONTINUE TO OVERTAKE NEB/KS/NRN OK PORTION OF DRY LINE THIS EVENING/OVERNIGHT...WITH THE FRONT REACHING NWRN MO TO NWRN TX BY SUNDAY MORNING. ...ERN PLAINS/MID MS VALLEY LARGE SCALE ASCENT AHEAD OF CLOSED MID-LEVEL LOW AND WITHIN EXIT REGION OF 60-70 KT WSWLY MID-LEVEL JET TRANSLATING EWD ACROSS THE LOWER MO/MID MS VALLEYS TO OH VALLEY WILL SUPPORT CONTINUATION OF THUNDERSTORMS ENEWD OVERNIGHT. AIR MASS EXPECTED TO REMAIN MODERATELY UNSTABLE FROM SURFACE LOW EWD ALONG WARM FRONT INTO WRN/CENTRAL IL. BACKED LOW-LEVEL WINDS EAST OF SURFACE LOW AND ALONG THE WARM FRONT COMBINED WITH STRENGTHENING SWLY LLJ ACROSS MO INTO CENTRAL IL WILL SUPPORT CONTINUED TORNADO THREAT FROM NERN KS TO SWRN IA EWD TO PARTS OF CENTRAL IL LATE. LARGE HAIL AND DAMAGING WIND GUSTS WILL REMAIN A THREAT AS WELL...WITH THESE THREATS POTENTIALLY EXTENDING AS FAR N AND E AS SERN SD AND CENTRAL/SRN IND...RESPECTIVELY. UPSCALE GROWTH OF ONGOING STORMS ALONG MID/LOWER MO VALLEY IS EXPECTED WITH ONE OR TWO MCS/S MOVING ENEWD AND REACHING SERN MN/SRN WI TO SWRN OH/KY BY 12Z SUNDAY. INSTABILITY...AND ATTENDANT SEVERE THREAT...WILL GRADUALLY DECREASE THIS EVENING WITH SWD EXTENT ALONG DRY LINE/COLD FRONT THROUGH ERN KS/WRN MO TO NERN OK AS LOSS OF INSOLATION STABILIZES BOUNDARY LAYER. ...OH VALLEY REGION TO MID-ATLANTIC STATES... WEAK LOW-LEVEL CONVERGENCE ALONG SURFACE BOUNDARY ACROSS SRN IND TO WV/SWRN VA COMBINED WITH MUCAPE AROUND 1000 J/KG EXPECTED TO SUPPORT ADDITIONAL THUNDERSTORM DEVELOPMENT...GIVEN 30-40 KT EFFECTIVE DEEP LAYER SHEAR. ISOLATED LARGE HAIL/STRONG WIND GUSTS SHOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. ..PETERS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 06:15:46 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 02:15:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160611 SWODY1 SPC AC 160609 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT SUN APR 16 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID MS/OH VALLEYS TO MID-ATLANTIC STATES... ...SYNOPSIS... WELL DEFINED CLOSED UPPER LOW...NOW LOCATED OVER ERN NEB PER WATER VAPOR IMAGERY...IS EXPECTED TO WEAKEN/BECOME AN OPEN WAVE TODAY AS IT MOVES ESEWD THROUGH MID/UPPER RIDGE AXIS ALONG THE MS VALLEY. BAND OF 55-65 KT MID-LEVEL FLOW ALONG SRN PERIPHERY OF THIS TROUGH SHOULD EXTEND FROM THE MID MS VALLEY TO VA/NC BY THIS AFTERNOON. IN THE LOW-LEVELS...SURFACE LOW OVER SWRN IA AT 12Z THIS MORNING WILL TRACK SEWD ALONG WARM FRONT THROUGH CENTRAL/SRN IL THIS AFTERNOON... AND THEN ACROSS SRN IND/NRN KY LATE THIS EVENING/OVERNIGHT. TRAILING COLD FRONT WILL SPREAD EWD ACROSS LOWER MO TO LOWER OH VALLEYS...WITH THE SRN EXTENT MOVING SLOWLY SWD ACROSS THE SRN PLAINS. ...MID MS/OH VALLEYS... AT 12Z TODAY...THUNDERSTORMS SHOULD BE ONGOING FROM PARTS OF THE UPPER MS VALLEY SEWD INTO THE OH VALLEY...PRIMARILY ALONG/N OF SURFACE WARM FRONT. LOW-LEVEL WAA AND LARGE SCALE ASCENT AHEAD OF UPPER TROUGH SHOULD MAINTAIN THIS EARLY ACTIVITY N OF WARM FRONT. SURFACE HEATING EXPECTED IN THE WARM SECTOR COMBINED WITH RESIDUAL MOISTURE /SURFACE DEWPOINTS IN THE UPPER 50S-LOWER 60S/ ALONG THIS BOUNDARY AND STEEP LAPSE RATES WILL SUPPORT MLCAPE VALUES UP TO 2000-2500 J/KG BY EARLY-MID AFTERNOON FROM SERN IA/ERN MO INTO THE OH VALLEY. THERMODYNAMICS COMBINED WITH LARGE SCALE ASCENT AHEAD OF UPPER TROUGH WILL ALLOW NEW THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON FROM SURFACE LOW SEWD ALONG THE WARM FRONT AND SWD ALONG THE COLD FRONT INTO SERN MO. STRONG DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS WITH SUPERCELLS POSSIBLE ESPECIALLY WITH INITIAL ACTIVITY FROM SERN IA/ERN MO INTO IL WHERE SHEAR VECTORS WILL BE ORIENTED MORE NORMAL TO SURFACE BOUNDARIES. BACKED LOW-LEVEL FLOW VICINITY SURFACE LOW/ALONG WARM FRONT IS EXPECTED TO ENHANCE THE THREAT FOR TORNADOES...WHILE STEEP LAPSE RATES ALSO SUPPORT A THREAT FOR VERY LARGE HAIL WITH SOME OF THE INITIAL STORMS. MODELS SUGGEST UPSCALE GROWTH INTO A FORWARD-PROPAGATING MCS ACROSS IL/IND AND WRN-NRN KY LATER THIS AFTERNOON/EVENING AS LOW-LEVEL JET VEERS AND SHEAR VECTORS BECOME ORIENTED PARALLEL TO WARM FRONT. DAMAGING WINDS SHOULD BECOME THE PRIMARY THREAT WITH THE MCS AS IT TRACKS SEWD THROUGH THE OH VALLEY...POTENTIALLY REACHING WV/WRN VA LATE IN THE PERIOD. STRONGER CAP LOCATED SOUTH OF MID-LEVEL JET AXIS SHOULD LIMIT SWD EXTENT OF SEVERE THREAT ALONG THE COLD FRONT TO THE VICINITY OF THE SERN MO/NERN AR BORDER REGION. ...MID-ATLANTIC STATES... POCKETS OF SURFACE HEATING EXPECTED TO OVERCOME WEAKLY CAPPED AIR MASS BY LATE MORNING/EARLY AFTERNOON TO AID IN THUNDERSTORM DEVELOPMENT ALONG THE SURFACE BOUNDARY. STEEP LAPSE RATES COMBINED WITH SURFACE DEWPOINTS IN THE 50S TO AROUND 60 ALONG THE SURFACE BOUNDARY EXPECTED TO SUPPORT MLCAPE VALUES AROUND 1000 J/KG BY THIS AFTERNOON. FAIRLY DEEP UNI-DIRECTIONAL WIND FIELDS AND STRONG DEEP LAYER SHEAR WILL SUPPORT A THREAT FOR ORGANIZED SEVERE STORMS. GIVEN STORMS SHOULD BE TIED TO SURFACE HEATING... THREAT SHOULD DECREASE AFTER SUNSET AS AIR MASS BEGINS TO STABILIZE WITH THE LOSS OF DAYTIME HEATING. ...NRN HIGH PLAINS... ENTRANCE REGION OF SWLY MID-LEVEL JET THAT MOVED INLAND OVER ORE/NRN CA SATURDAY EVENING PER 00Z UPPER AIR ANALYSIS IS EXPECTED TO BE LOCATED OVER THE NRN HIGH PLAINS BY LATE THIS AFTERNOON/EARLY EVENING. LARGE SCALE ASCENT ASSOCIATED WITH THIS FEATURE WILL AID IN THUNDERSTORM DEVELOPMENT THIS AFTERNOON AS COLD FRONT MOVES EWD ACROSS ERN MT/WY. INCREASING SSELY LOW-LEVEL WINDS BY LATE AFTERNOON/EVENING OVER THE WRN DAKOTAS SHOULD AID IN THE TRANSPORT OF A NARROW PLUME OF MOISTURE BENEATH PLUME OF STEEP LAPSE RATES. THUS...WEAK INSTABILITY MAY SUPPORT AN ISOLATED SEVERE THREAT WITH STORMS THAT FORM ALONG THE COLD FRONT AS IT MOVES EWD ACROSS THE NRN HIGH PLAINS THIS EVENING. ..PETERS/GRAMS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 12:53:46 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 08:53:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161250 SWODY1 SPC AC 161248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT SUN APR 16 2006 VALID 161300Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VLY TO THE NC CST... ...SYNOPSIS... WRN IA CLOSED LOW EXPECTED TO MOVE ESE ACROSS THE REMAINDER OF THAT STATE TODAY...BEFORE ACCELERATING ESE ACROSS IL/IND TONIGHT AS THE SYSTEM WEAKENS AND IS REABSORBED INTO THE WLYS. ASSOCIATED SURFACE LOW SHOULD REACH THE QUINCY AREA BY 00Z SUNDAY AS TRAILING PACIFIC COLD FRONT/DRY LINE SWEEPS E INTO S CNTRL IL. FRONTAL ZONE EXTENDING ESE FROM THE LOW INTO KY AND NC SHOULD BECOME MORE SHARPLY DEFINED TODAY AND LIKELY WILL SHOW LITTLE OVERALL MOVEMENT. ...SRN WI/NRN IL TO LWR OH VLY --- NEAR TERM... WARM ADVECTION/UPLIFT ON DOWNWIND SIDE OF SLIGHTLY ELEVATED INSTABILITY AXIS HAS SUPPORTED DEVELOPMENT OF SCATTERED STORMS OVER PARTS OF IL SWD INTO WRN KY IN THE PAST 2 HRS. SUFFICIENT ELEVATED INSTABILITY IS PRESENT TO SUPPORT SOME HAIL /MUCAPE TO 800 J PER KG/. BUT STORM MERGERS...AND MOVEMENT OF FORCING MECHANISM NEWD BEYOND LLJ/INSTABILITY AXIS...SUGGEST THAT OVERALL SEVERE THREAT WILL BE LIMITED /REF MCD 523/. ...MID MS INTO LWR OH VLY... SURFACE HEATING AND MID LEVEL COLD ADVECTION/ASCENT IN EXIT REGION OF SPEED MAX ROUNDING BASE OF IA LOW EXPECTED TO FOSTER STORM DEVELOPMENT BY EARLY AFTERNOON NEAR SURFACE LOW OVER SE IA/WRN IL AND PERHAPS NE MO. DEEP SHEAR INVOF THIS INITIAL ACTIVITY WILL NOT BE ESPECIALLY STRONG. BUT STEEP LOW TO MID LEVEL LAPSE RATES AND ENHANCED LOW LEVEL VEERING PROFILES NEAR STATIONARY FRONT SUGGEST POTENTIAL FOR HAIL AND POSSIBLY A BRIEF TORNADO OR TWO. WITH CONTINUED HEATING...EXPECT THAT STORMS WILL DEVELOP SWD ALONG COLD FRONT OVER FAR ERN MO...AND ESE ALONG STATIONARY FRONT INTO IL. THIS DEVELOPMENT WILL OCCUR AS AFOREMENTIONED JET STREAK ELONGATES AND RESULTS IN STRENGTHENING OF DEEP SHEAR EWD ALONG STATIONARY FRONT INTO SRN IL/SW IND AND WRN KY. BOUNDARY LAYER MOISTURE AVAILABILITY WILL BE A BIT LIMITED /AVERAGE SURFACE DEWPOINTS AROUND 60 F/ BY COMPARISON TO MORE WIDESPREAD SEVERE WEATHER EVENTS. BUT GIVEN STRONG HEATING...SUFFICIENT MOISTURE WILL BE PRESENT TO YIELD SBCAPE OF 1500-2000 J/KG. WITH 40+ KT DEEP WNWLY SHEAR ORIENTED PARALLEL TO STATIONARY FRONT...A CONCENTRATED AREA OF SUSTAINED SUPERCELLS APPEARS LIKELY. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL/HIGH WIND AND TORNADOES...ESPECIALLY IN S CNTRL IL INTO WRN KY/SW IND. INCREASED CIN WITH SWD EXTENT SHOULD PROHIBIT STORM DEVELOPMENT SWD ALONG COLD FRONT INTO AR/TN. BY THIS EVENING EXPECT THAT THE STORMS WILL HAVE COALESCED INTO A COMPLEX...WITH EMBEDDED SUSTAINED STORMS/POSSIBLE SUPERCELLS IN KY/SRN IND. COUPLED WITH INCREASINGLY UNIDIRECTIONAL WIND FIELD AND ORIENTATION OF LOW LEVEL INSTABILITY AXIS EXTENDING TO THE ESE...THE SETUP COULD SUPPORT EVOLUTION INTO A FORWARD-PROPAGATING SQUALL LINE. IF SUCH A SYSTEM DEVELOPS...AN ATTENDANT THREAT FOR HIGH WIND AND HAIL COULD REACH THE WRN SLOPES OF THE CNTRL/SRN APPALACHIANS EARLY MONDAY. ...WV/SW VA INTO NC... A SECONDARY FOCUS FOR STRONG...MAINLY DIURNAL STORM DEVELOPMENT WILL EXIST ALONG AND JUST S OF ERN EXTENSION OF SAME FRONT AFFECTING THE OH VLY. THE DIFFUSE FRONT SHOULD BECOME STATIONARY FROM SRN WV INTO ERN NC LATER TODAY. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK AT BEST...AND INITIATION MAY BE TIED MORE TO OROGRAPHIC SOURCES THAN TO FRONT. BUT COMBINATION OF STRONG SURFACE HEATING WITH RELATIVELY STEEP MID LEVEL LAPSE RATES AND 40-50 KT DEEP UNIDIRECTIONAL WNWLY SHEAR WILL BE FAVORABLE FOR WIDELY SCATTERED SUSTAINED STORMS/SUPERCELLS WITH HAIL/HIGH WIND. ...NRN GRT BASIN TO NRN HI PLNS... BROAD...FAIRLY STRONG E PACIFIC TROUGH WILL MOVE INLAND THIS PERIOD AS EMBEDDED SHORTWAVE IMPULSE NOW ENTERING NRN CA CONTINUES E INTO NV. ELSEWHERE...ASCENT WILL ALSO INCREASE OVER ERN MT/WRN ND...IN ENTRANCE REGION OF DOWNSTREAM JET STREAK OVER SASKATCHEWAN. COMBINATION OF SURFACE HEATING WITH INCREASING LARGE SCALE ASCENT SHOULD FOSTER STORM DEVELOPMENT ALONG ASSOCIATED COLD FRONT FROM THE NRN HI PLNS SWWD INTO THE NRN GRT BASIN. THERMODYNAMIC AND KINEMATIC ENVIRONMENT SUGGEST POTENTIAL FOR A FEW STORMS WITH SEVERE OR NEAR SEVERE WINDS ALONG THIS CORRIDOR LATER TODAY THROUGH EARLY TONIGHT. ..CORFIDI/GRAMS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 13:03:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 09:03:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161259 SWODY1 SPC AC 161258 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT SUN APR 16 2006 VALID 161300Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF IL...WRN KY AND SW IND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VLY TO THE NC CST... CORRECTED FOR PARTS OF STATES IN MDT RISK ...SYNOPSIS... WRN IA CLOSED LOW EXPECTED TO MOVE ESE ACROSS THE REMAINDER OF THAT STATE TODAY...BEFORE ACCELERATING ESE ACROSS IL/IND TONIGHT AS THE SYSTEM WEAKENS AND IS REABSORBED INTO THE WLYS. ASSOCIATED SURFACE LOW SHOULD REACH THE QUINCY AREA BY 00Z SUNDAY AS TRAILING PACIFIC COLD FRONT/DRY LINE SWEEPS E INTO S CNTRL IL. FRONTAL ZONE EXTENDING ESE FROM THE LOW INTO KY AND NC SHOULD BECOME MORE SHARPLY DEFINED TODAY AND LIKELY WILL SHOW LITTLE OVERALL MOVEMENT. ...SRN WI/NRN IL TO LWR OH VLY --- NEAR TERM... WARM ADVECTION/UPLIFT ON DOWNWIND SIDE OF SLIGHTLY ELEVATED INSTABILITY AXIS HAS SUPPORTED DEVELOPMENT OF SCATTERED STORMS OVER PARTS OF IL SWD INTO WRN KY IN THE PAST 2 HRS. SUFFICIENT ELEVATED INSTABILITY IS PRESENT TO SUPPORT SOME HAIL /MUCAPE TO 800 J PER KG/. BUT STORM MERGERS...AND MOVEMENT OF FORCING MECHANISM NEWD BEYOND LLJ/INSTABILITY AXIS...SUGGEST THAT OVERALL SEVERE THREAT WILL BE LIMITED /REF MCD 523/. ...MID MS INTO LWR OH VLY... SURFACE HEATING AND MID LEVEL COLD ADVECTION/ASCENT IN EXIT REGION OF SPEED MAX ROUNDING BASE OF IA LOW EXPECTED TO FOSTER STORM DEVELOPMENT BY EARLY AFTERNOON NEAR SURFACE LOW OVER SE IA/WRN IL AND PERHAPS NE MO. DEEP SHEAR INVOF THIS INITIAL ACTIVITY WILL NOT BE ESPECIALLY STRONG. BUT STEEP LOW TO MID LEVEL LAPSE RATES AND ENHANCED LOW LEVEL VEERING PROFILES NEAR STATIONARY FRONT SUGGEST POTENTIAL FOR HAIL AND POSSIBLY A BRIEF TORNADO OR TWO. WITH CONTINUED HEATING...EXPECT THAT STORMS WILL DEVELOP SWD ALONG COLD FRONT OVER FAR ERN MO...AND ESE ALONG STATIONARY FRONT INTO IL. THIS DEVELOPMENT WILL OCCUR AS AFOREMENTIONED JET STREAK ELONGATES AND RESULTS IN STRENGTHENING OF DEEP SHEAR EWD ALONG STATIONARY FRONT INTO SRN IL/SW IND AND WRN KY. BOUNDARY LAYER MOISTURE AVAILABILITY WILL BE A BIT LIMITED /AVERAGE SURFACE DEWPOINTS AROUND 60 F/ BY COMPARISON TO MORE WIDESPREAD SEVERE WEATHER EVENTS. BUT GIVEN STRONG HEATING...SUFFICIENT MOISTURE WILL BE PRESENT TO YIELD SBCAPE OF 1500-2000 J/KG. WITH 40+ KT DEEP WNWLY SHEAR ORIENTED PARALLEL TO STATIONARY FRONT...A CONCENTRATED AREA OF SUSTAINED SUPERCELLS APPEARS LIKELY. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL/HIGH WIND AND TORNADOES...ESPECIALLY IN S CNTRL IL INTO WRN KY/SW IND. INCREASED CIN WITH SWD EXTENT SHOULD PROHIBIT STORM DEVELOPMENT SWD ALONG COLD FRONT INTO AR/TN. BY THIS EVENING EXPECT THAT THE STORMS WILL HAVE COALESCED INTO A COMPLEX...WITH EMBEDDED SUSTAINED STORMS/POSSIBLE SUPERCELLS IN KY/SRN IND. COUPLED WITH INCREASINGLY UNIDIRECTIONAL WIND FIELD AND ORIENTATION OF LOW LEVEL INSTABILITY AXIS EXTENDING TO THE ESE...THE SETUP COULD SUPPORT EVOLUTION INTO A FORWARD-PROPAGATING SQUALL LINE. IF SUCH A SYSTEM DEVELOPS...AN ATTENDANT THREAT FOR HIGH WIND AND HAIL COULD REACH THE WRN SLOPES OF THE CNTRL/SRN APPALACHIANS EARLY MONDAY. ...WV/SW VA INTO NC... A SECONDARY FOCUS FOR STRONG...MAINLY DIURNAL STORM DEVELOPMENT WILL EXIST ALONG AND JUST S OF ERN EXTENSION OF SAME FRONT AFFECTING THE OH VLY. THE DIFFUSE FRONT SHOULD BECOME STATIONARY FROM SRN WV INTO ERN NC LATER TODAY. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK AT BEST...AND INITIATION MAY BE TIED MORE TO OROGRAPHIC SOURCES THAN TO FRONT. BUT COMBINATION OF STRONG SURFACE HEATING WITH RELATIVELY STEEP MID LEVEL LAPSE RATES AND 40-50 KT DEEP UNIDIRECTIONAL WNWLY SHEAR WILL BE FAVORABLE FOR WIDELY SCATTERED SUSTAINED STORMS/SUPERCELLS WITH HAIL/HIGH WIND. ...NRN GRT BASIN TO NRN HI PLNS... BROAD...FAIRLY STRONG E PACIFIC TROUGH WILL MOVE INLAND THIS PERIOD AS EMBEDDED SHORTWAVE IMPULSE NOW ENTERING NRN CA CONTINUES E INTO NV. ELSEWHERE...ASCENT WILL ALSO INCREASE OVER ERN MT/WRN ND...IN ENTRANCE REGION OF DOWNSTREAM JET STREAK OVER SASKATCHEWAN. COMBINATION OF SURFACE HEATING WITH INCREASING LARGE SCALE ASCENT SHOULD FOSTER STORM DEVELOPMENT ALONG ASSOCIATED COLD FRONT FROM THE NRN HI PLNS SWWD INTO THE NRN GRT BASIN. THERMODYNAMIC AND KINEMATIC ENVIRONMENT SUGGEST POTENTIAL FOR A FEW STORMS WITH SEVERE OR NEAR SEVERE WINDS ALONG THIS CORRIDOR LATER TODAY THROUGH EARLY TONIGHT. ..CORFIDI.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 16:38:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 12:38:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161635 SWODY1 SPC AC 161633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT SUN APR 16 2006 VALID 161630Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PART OF IL INTO SWRN IND AND FAR NWRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM IA TO THE NC/VA COAST... ...IA INTO THE OH RIVER VALLEY... STRONG UPPER SYSTEM WITH NEARLY VERTICALLY STACKED LOW CENTER NOW OVER CENTRAL IA WILL TRACK ESEWD ACROSS CENTRAL IL...WITH TRAILING SURFACE TROUGH ADVANCING ESEWD ACROSS THE MID MS RIVER VALLEY TODAY. THIS WILL SUPPORT WIDESPREAD SEVERE THUNDERSTORMS INTO ERN IA AND MUCH OF IL THIS AFTERNOON...SPREADING INTO WRN IN/NRN KY THIS EVENING. BOTH DEEP LAYER SHEAR AND MID LEVEL LAPSE RATES REMAIN QUITE IMPRESSIVE ACCORDING TO OBSERVED AND FORECAST SOUNDINGS. 12Z NAM CONTINUES TO OVERFORECAST SURFACE DEW POINTS AHEAD OF THIS SYSTEM. HOWEVER...COLD TEMPERATURES ALOFT/STEEP LAPSE RATES ALONG WITH VERY STRONG LARGE SCALE ASCENT SUGGEST LOWER 60F SURFACE DEW POINTS WILL BE MORE THAN ADEQUATE FOR MODERATE INSTABILITY AND AN ENHANCED SEVERE THUNDERSTORM THREAT TODAY. DEVELOPMENT WILL LIKELY OCCUR IN TWO DIFFERENT MODES. ONE WILL BE UNDER COLD UPPER LOW WHERE VERY STRONG AMBIENT VORTICITY AND STEEP LOW LEVEL LAPSE RATES/MODERATE SFC-3 KM CAPE WILL BE FOUND. DEVELOPMENT IS ALREADY INCREASING IN THIS ENVIRONMENT ACROSS CENTRAL IA AND WILL SHIFT INTO NERN MO/ERN IA AND WRN IL THROUGH THE DAY. ADDITIONAL DEVELOPMENT IS EXPECTED TO OCCUR ALONG SURFACE WARM FRONT EXTENDING INTO CENTRAL IND AND AHEAD OF SURFACE TROUGH ADVANCING INTO ERN MO DURING THE AFTERNOON. SHEAR PARAMETERS ARE STRONGER ACROSS THIS REGION AND LOW LEVEL SHEAR WILL REMAIN STRONG DESPITE DEEP WLY COMPONENT. GIVEN AMOUNT OF SHEAR...MLCAPE SHOULD EXCEED 1500 J/KG AND SUPPORT SUPERCELLS ACROSS THIS REGION...WITH EVENTUAL EVOLUTION INTO ONE OR MORE LEWP STRUCTURES. TORNADO THREAT WILL REMAIN HIGHEST NEAR THE WARM FRONT/AHEAD OF LOW CENTER WHERE STRONG PRESSURE FALLS AND BACKED SURFACE WINDS WILL ENHANCE LOW LEVEL HELICITY...THOUGH ISOLATED TORNADOES WILL LIKELY OCCUR WITH WARM SECTOR DEVELOPMENT INTO THE OH RIVER VALLEY. LARGE MCS SHOULD DEVELOP AND SPREAD ESEWD INTO THE IND AND SWRN OH/KY THROUGH THE EVENING. DAMAGING WINDS MAY ALSO BECOME WIDESPREAD WITH THIS MCS AS ACTIVITY ORGANIZES ALONG LEADING OUTFLOW BOUNDARY. ...WV/ERN KY INTO SRN VA/NC... SEVERE THREAT WILL REMAIN ALONG STALLED SURFACE FRONT EXTENDING WNW-ESE ACROSS THIS REGION TODAY. WITH LIMITED LARGE SCALE ASCENT AND MODEST CAPPING ON 12Z SOUNDINGS...ACTIVITY WILL LIKELY BE STRONGLY DRIVEN BY DIURNAL HEATING. HOWEVER...DEEP LAYER SHEAR REMAINS STRONG WITH EFFECTIVE BULK SHEAR EXCEEDING 40 KT. IN ADDITION...STEEP LAPSE RATES AND 55-60F SURFACE DEW POINTS SHOULD SUPPORT MODEST INSTABILITY BY THE MID TO LATE AFTERNOON. LARGE HAIL AND DAMAGING WINDS WILL REMAIN PRIMARY SEVERE THREATS WITH FAIRLY HIGH-BASED STORMS AS THEY SPREAD ESEWD THROUGH THE EVENING. HOWEVER...AN ISOLATED TORNADO COULD OCCUR GIVEN LOCATION OF SURFACE BOUNDARY/INCREASED LOW LEVEL SHEAR AND LIKELIHOOD OF PERSISTENT SUPERCELL STRUCTURES. ..EVANS/GUYER.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 20:05:24 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 16:05:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 162001 SWODY1 SPC AC 161959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT SUN APR 16 2006 VALID 162000Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF IL...IND AND WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST...OH VALLEY...CNTRL APPALACHIANS AND ATLANTIC COASTAL PLAINS... ...UPPER MIDWEST/OH VALLEY... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW AN UPPER-LEVEL LOW OVER THE MID-MS VALLEY WITH STRONG LARGE-SCALE ASCENT CURRENTLY SPREADING EWD ACROSS THE OH VALLEY. A LINE OF INTENSE STORMS WRAPPING AROUND THE SYSTEM IS ONGOING AND WILL CONTINUE TO MOVE EWD ACROSS THE MODERATE RISK AREA. THE AIRMASS IS CHARACTERIZED BY MODERATE INSTABILITY AND STRONG VERTICAL SHEAR WHICH WILL BE VERY SUPPORTIVE OF SUPERCELLS. THE POTENTIAL FOR SUPERCELLS WILL INCREASE SWD ACROSS ERN IL AS INTENSIFICATION OF THE LINE CONTINUES. SUPERCELLS WILL ALSO BE POSSIBLE AHEAD OF THE LINE ACROSS IND ALONG THE NRN EDGE OF THE INSTABILITY GRADIENT. SFC DEWPOINTS IN THE 60S F COMBINED WITH STRONG VERTICAL SHEAR AND THE MODERATE INSTABILITY WILL MAKE THE STRONGER STORMS CAPABLE OF PRODUCING TORNADOES...LARGE HAIL AND WIND DAMAGE. A FEW OF THE MORE INTENSE SUPERCELLS WILL LIKELY BE CAPABLE OF VERY LARGE HAIL AND VERY HIGH WINDS. AS THE UPPER-TROUGH CONTINUES ESEWD LATE THIS AFTERNOON...THE SEVERE THREAT SHOULD EXPAND ESEWD ACROSS THE MODERATE RISK AREA. THE WIND DAMAGE POTENTIAL MAY BECOME ENHANCED AS A LARGE MCS DEVELOPS AND MOVES ESEWD ACROSS THE SERN PART OF THE MODERATE RISK AREA THIS EVENING. THE SEVERE THREAT SHOULD GRADUALLY DROP OFF OVERNIGHT AS INSTABILITY WEAKENS AND THE MCS APPROACHES THE CNTRL APPALACHIAN MTNS. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... A SHORTWAVE RIDGE IS EVIDENT ON WATER VAPOR OVER THE CNTRL APPALACHIANS AHEAD OF AN APPROACHING UPPER-LEVEL LOW/TROUGH OVER THE LOWER OH VALLEY. SCATTERED THUNDERSTORMS ARE ONGOING IN THE APPALACHIANS AND UNDER THE RIDGE WHERE LARGE-SCALE ASCENT IS RELATIVELY WEAK. EVEN SO...INSTABILITY AND STRONG VERTICAL SHEAR SHOULD BE SUPPORTIVE OF A FEW SEVERE STORMS LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE GREATEST THREAT OF SEVERE WILL BE ALONG THE INSTABILITY AXIS EXTENDING SEWD FROM ERN KY ACROSS SRN WV INTO CNTRL AND ERN NC. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER CELLS WITH THE SEVERE THREAT GRADUALLY DECREASING THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/16/2006  From SwoDy1 at goshenarc.org Mon Apr 17 01:04:17 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 21:04:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170100 SWODY1 SPC AC 170058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 PM CDT SUN APR 16 2006 VALID 170100Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY... ...OH VALLEY... CLOSED UPPER LOW...NOW LOCATED OVER ERN IA...WILL CONTINUE TO DE-AMPLIFY AS IT EVOLVES INTO AN OPEN WAVE TRACKING SEWD INTO THE LOWER OH VALLEY...REACHING SRN IND/OH REGION BY 12Z MONDAY. IN THE LOW-LEVELS...A SURFACE LOW WAS LOCATED OVER CENTRAL/SRN IL WITH A WARM FRONT EXTENDING ESEWD THROUGH CENTRAL/SRN IND TO SWRN OH AND SRN WV. SURFACE LOW IS EXPECTED TO TRACK ALONG THIS BOUNDARY INTO SRN IND THIS EVENING AND THEN REACHING ERN KY TOWARD 12Z. 50-60 KT WNWLY MID-LEVEL JET OVER NRN MO WILL TRANSLATE ESEWD INTO KY MAINTAINING LARGE SCALE ASCENT WITHIN EXIT REGION FOR ADDITIONAL THUNDERSTORMS SEWD ACROSS SRN IND...CENTRAL/ERN KY AND SWRN OH. GRADUAL DECREASE IN AVAILABLE CONVECTIVE INSTABILITY/BOUNDARY LAYER STABILIZATION...GIVEN LOSS OF DAYTIME HEATING...SUGGESTS OVERALL SEVERE THREAT SHOULD BEGIN TO DECREASE GENERALLY AFTER 03Z. UNTIL THEN...40-50 KT SWLY LLJ ALONG THE LOWER OH VALLEY AND BENEATH WNWLY MID-LEVEL FLOW WILL CONTINUE TO SUPPORT SUPERCELLS WITH AN ATTENDANT TORNADO POTENTIAL FOR THE NEXT COUPLE OF HOURS AS ACTIVITY SPREADS ESEWD ACROSS SRN IND INTO PARTS OF NWRN-NRN KY. HAIL/DAMAGING WINDS WILL ALSO REMAIN A THREAT WITH THE ACTIVITY THIS EVENING. VEERING LLJ OVERNIGHT AND DECREASING TREND IN DEEP LAYER SHEAR/INSTABILITY SHOULD LIMIT SEVERE THREAT WITH ANY THUNDERSTORMS LATER IN THE PERIOD. HOWEVER...WEAK INSTABILITY AND 25-35 KT OF EFFECTIVE DEEP LAYER SHEAR MAY SUPPORT A FEW ISOLATED STRONG TO SEVERE STORMS WITH STRONG WIND GUSTS/MARGINALLY SEVERE HAIL THE PRIMARY THREATS AS STORMS SPREAD INTO SRN OH/ERN KY. ...MID-ATLANTIC STATES... WATER VAPOR IMAGERY INDICATED AN APPARENT MID-LEVEL IMPULSE LOCATED OVER VA/NRN NC AT 00Z. THE COMBINATION OF THIS FEATURE MOVING OFFSHORE IN THE NEXT FEW HOURS AND CONTINUATION OF BOUNDARY LAYER STABILIZATION IS EXPECTED TO DIMINISH THREAT FOR ADDITIONAL THUNDERSTORMS WITH ATTENDANT SEVERE POTENTIAL. ..PETERS.. 04/17/2006  From SwoDy1 at goshenarc.org Mon Apr 17 05:49:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 17 Apr 2006 01:49:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170545 SWODY1 SPC AC 170544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON APR 17 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS MAINLY THIS AFTERNOON ACROSS NC/SC... ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF NEB/SD/ND... ...NC/SC... OH VALLEY MID-LEVEL TROUGH WILL UNDERGO FURTHER DE-AMPLIFICATION TODAY AS IT TRACKS ESEWD TOWARD VA/NC/SC...EVENTUALLY BECOMING ABSORBED BY NERN STATES UPPER TROUGH...AND EJECTING EWD OVER THE WRN ATLANTIC. ACCOMPANYING BAND OF STRONG WLY MID-LEVEL WINDS AT 60-65 KT WILL TRANSLATE EWD ACROSS NC/SC THIS MORNING/AFTERNOON. IN THE LOW-LEVELS...SURFACE BOUNDARY INITIALLY EXTENDING W-E OVER NRN NC IS EXPECTED TO MOVE SSE ACROSS THE CAROLINAS AND SHOULD BE THE PRIMARY FOCUS FOR THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING AS IT MOVES SWD ACROSS NC/SC. SURFACE LOW EXPECTED TO BE LOCATED OVER ERN KY AT 12Z TODAY WILL WEAKEN AS IT MOVES INTO WV. DOWNSTREAM HEIGHT FALLS SHOULD AID SECONDARY SURFACE WAVE DEVELOPMENT ALONG SURFACE FRONT IN WRN/CENTRAL NC THIS MORNING BEFORE THIS LOW TRACKS OFFSHORE BY 00Z WITH THE FRONT. DESPITE MODEST MID-LEVEL LAPSE RATES ACROSS THE CAROLINAS...STRONG SURFACE HEATING EXPECTED S OF COLD FRONT AND SURFACE DEWPOINTS POTENTIALLY NEAR 60 F SHOULD SUPPORT MODERATE INSTABILITY BY AFTERNOON. THUNDERSTORMS MAY BE ONGOING OVER WV/NERN TN AT START OF DAY 1 PERIOD...WITH THIS ACTIVITY TRACKING ESEWD ACROSS THE HIGHER TERRAIN AND THEN INTO SRN VA/NRN NC THIS MORNING WITHIN WEAK WAA REGIME. ADDITIONAL STORMS EXPECTED TO DEVELOP AS COLD FRONT MOVES SWD INTO MODERATELY UNSTABLE AIR MASS. STRONG DEEP LAYER SHEAR VECTORS ORIENTED PARALLEL TO THE FRONT SUGGEST STORM MODE SHOULD BE LINEAR...BUT HIGH SHEAR VALUES MAY SUPPORT A FEW EMBEDDED SUPERCELLS. HAIL WILL BE POSSIBLE WITH THE STRONGEST ACTIVITY... WHILE STEEP LOW-LEVEL LAPSE RATES SHOULD ENHANCE STRONG WIND GUST POTENTIAL. SEVERE THREAT SHOULD DIMINISH BY 00Z AS FRONT MOVES OFFSHORE. ...ND/SD/NEB... SHORT WAVE TROUGH...CURRENTLY MOVING INLAND OVER NRN CA PER WATER VAPOR IMAGERY...WITHIN BASE OF WRN STATES LONG WAVE TROUGH...IS EXPECTED TO MOVE EWD WITH MAIN TROUGH APPROACHING THE CENTRAL/NRN HIGH PLAINS BY 12Z TUESDAY. SURFACE CYCLOGENESIS IS EXPECTED OVER ERN WY IN RESPONSE TO HEIGHT FALLS IN ADVANCE OF THE APPROACHING UPPER TROUGH. THIS LOW SHOULD BE LOCATED ALONG THE INTERSECTION OF A LEE-SIDE TROUGH AND A PACIFIC COLD FRONT WHICH SHOULD EXTEND FROM WRN ND INTO NRN WY BY LATE THIS AFTERNOON. THIS LOW WILL THEN DEVELOP/TRACK SEWD INTO THE CENTRAL PLAINS ALONG A NWD RETREATING WARM FRONT. STRENGTHENING SELY LOW-LEVEL WINDS ACROSS THE CENTRAL/NRN PLAINS WILL LIKELY ADVECT RESIDUAL MOISTURE /SURFACE DEWPOINTS IN THE LOWER 50S CURRENTLY LOCATED OVER EAST CENTRAL PLAINS/ NWWD INTO WRN PORTIONS OF SD/NEB BY LATE AFTERNOON. STEEP MID-LEVEL LAPSE RATES OVER WRN PORTIONS OF THE NRN/CENTRAL PLAINS ATOP THE MOISTURE RETURN WILL SUPPORT A NARROW AXIS OF MUCAPES AROUND 1000 J/KG EXTENDING NNWWD ACROSS THE SLIGHT RISK AREA BY LATE AFTERNOON/EARLY EVENING. THUNDERSTORMS SHOULD DEVELOP IN THE VICINITY OF THE SURFACE LOW OVER NERN WY TO SWRN ND BY LATE AFTERNOON AS LARGE SCALE ASCENT SPREADS ACROSS REGION AHEAD OF UPPER TROUGH. SEVERE THREAT WILL LIKELY BE ISOLATED WITH INITIAL ACTIVITY...SINCE INSTABILITY SHOULD BE WEAKER DUE TO LESS BOUNDARY LAYER MOISTURE WITHIN A DEEPLY MIXED ENVIRONMENT. A GREATER SEVERE THREAT IS EXPECTED AS THE COLD FRONT MOVES EWD INTO THE INSTABILITY AXIS ACROSS WRN PORTIONS OF SD/NEB THIS EVENING/OVERNIGHT. STRONG DEEP LAYER SHEAR WILL SUPPORT STORM ORGANIZATION WITH HAIL AND STRONG WIND GUSTS THE PRIMARY THREATS...WITH ACTIVITY POTENTIALLY BECOMING MORE ELEVATED WITH EWD EXTENT. ..PETERS/GRAMS.. 04/17/2006  From SwoDy1 at goshenarc.org Tue Apr 18 00:52:59 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 17 Apr 2006 20:52:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180049 SWODY1 SPC AC 180047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CDT MON APR 17 2006 VALID 180100Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE NRN HIGH PLAINS... ...WRN DAKOTAS/NWRN-NRN NEB... VIGOROUS SHORT WAVE TROUGH MOVING INTO SWRN WY...AND LOCATED WITHIN BASE OF COLD UPPER TROUGH OVER THE NRN INTERMOUNTAIN WEST/NRN ROCKIES...WILL BECOME MORE NEGATIVELY TILTED OVERNIGHT AS IT APPROACHES THE NRN HIGH PLAINS. SSELY LLJ IS PROGGED TO STRENGTHEN TO 60 KT ACROSS THE CENTRAL/NRN PLAINS IN RESPONSE TO HEIGHT FALLS AHEAD OF THE UPPER TROUGH. EARLY EVENING SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING FROM WRN ND SWWD THROUGH ERN WY TO WRN CO/SERN UT...WITH THIS BOUNDARY MOVING EWD INTO THE PLAINS TONIGHT. SURFACE LOW...NOW LOCATED OVER FAR SERN WY EXPECTED TO DEVELOP SEWD ALONG WARM FRONT INTO CENTRAL KS BY 12Z TUESDAY. INCREASINGLY DIFFLUENT FLOW AHEAD OF NEGATIVELY TILTED TROUGH AND STRENGTHENING WAA REGIME WITH STRONG LLJ WILL SUPPORT CONTINUED THUNDERSTORM DEVELOPMENT OVERNIGHT AS THE COLD FRONT MOVES EWD. SURFACE-BASED STORMS WILL REMAIN POSSIBLE ALONG THE COLD FRONT THIS EVENING...WITH STORMS BECOMING MORE ELEVATED LATER THIS EVENING/ TONIGHT AS THE BOUNDARY LAYER COOLS. STRONG DEEP LAYER SHEAR VECTORS INITIALLY ORIENTED MORE NORMAL TO COLD FRONT WILL SUPPORT DISCRETE STORMS FOR A FEW MORE HOURS...WITH EVENTUAL EVOLUTION INTO A LINEAR MODE AS VECTORS BECOME ORIENTED PARALLEL TO FRONT. LARGE HAIL AND STRONG WIND GUSTS EXPECTED TO REMAIN PRIMARY THREATS GIVEN STEEP LAPSE RATES...WITH HAIL BECOMING MAIN THREAT OVERNIGHT AS ELEVATED ACTIVITY POTENTIALLY REACHES CENTRAL PARTS OF ND/SD/NRN NEB. ...SC... SEVERE THREAT HAS ENDED ACROSS THE CAROLINAS AS STRONGEST FORCING HAS SHIFTED OFFSHORE. A FEW THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS MAINLY SRN SC FOR THE NEXT COUPLE OF HOURS AS WEAK WAA PERSISTS ALONG TRAILING PORTION OF COLD FRONT /ANALYZED FROM NEAR CHS-GSP AT 00Z/ MOVING SWD THROUGH THIS REGION. CONTINUED AIR MASS STABILIZATION SHOULD PRECLUDE ADDITIONAL SEVERE THREAT. ..PETERS.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 06:05:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 02:05:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180602 SWODY1 SPC AC 180600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT TUE APR 18 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO VALLEY TO THE OZARKS/LOWER TN VALLEY REGION... ...SYNOPSIS... HIGH AMPLITUDE LARGE SCALE PATTERN WILL CONTINUE ACROSS THE U.S. TODAY...CHARACTERIZED BY OMEGA BLOCK EXTENDING FROM WRN ATLANTIC WWD TO THE PLAINS. WRN EXTENT OF THIS BLOCKING PATTERN WILL BE A MID/ UPPER LEVEL TROUGH MOVING EWD AND INTENSIFYING INTO A CLOSED LOW ACROSS NRN/CENTRAL PLAINS. 80+ KT MID-LEVEL JET WITH THIS SYSTEM WILL TRANSLATE NEWD TODAY AND EXTEND FROM WRN KS TO MID MO VALLEY BY EARLY EVENING. IN THE LOW-LEVELS...OCCLUSION OF NRN MOST SURFACE LOW IS EXPECTED OVER THE ERN DAKOTAS THIS MORNING AS STRONG COLD FRONT OVERTAKES NRN EXTENT OF WARM FRONT WHICH WILL EXTEND ALONG THE MID/LOWER MO VALLEY INTO THE LOWER TN VALLEY AND SERN STATES. SECONDARY SURFACE LOW AT OCCLUSION POINT OF PROGRESSIVE COLD FRONT IS EXPECTED TO BE LOCATED ACROSS NWRN MO BY LATE AFTERNOON...WITH THIS LOW TRACKING SEWD INTO LOWER TN VALLEY TONIGHT. ...MID AND LOWER MO VALLEY INTO OZARKS/LOWER TN VALLEY... LATEST SURFACE OBSERVATIONS INDICATED DEWPOINTS IN THE UPPER 60S AS FAR NORTH AS SERN OK/SRN AR. SLY LOW-LEVEL FLOW WITHIN THE WARM SECTOR WILL ALLOW THIS MOISTURE TO RETURN NWD TODAY WITH UPPER 60S DEWPOINTS POTENTIALLY REACHING AS FAR N AS CENTRAL/NRN MO THIS AFTERNOON. PLUME OF STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH THE NRN/CENTRAL PLAINS UPPER SYSTEM WILL ADVECT EWD CAPPING THE WARM SECTOR THROUGH MUCH OF THE DAY. THESE LAPSE RATES COMBINED WITH STRONG SURFACE HEATING AND SURFACE DEWPOINTS IN THE 60S EXPECTED TO RESULT IN SBCAPE AOA 3000 J/KG FROM MO SSWWD TO THE ARKLATEX REGION. THUNDERSTORMS MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ACROSS PARTS OF THE CENTRAL/ERN DAKOTAS. LARGE SCALE ASCENT AHEAD OF THE INTENSIFYING UPPER TROUGH AND LOW-LEVEL WAA SHOULD SUPPORT A CONTINUATION OF THIS ACTIVITY EWD TOWARD SWRN MN AND SEWD DEVELOPMENT INTO ERN NEB/WRN IA WITH GRADUAL INCREASE IN COVERAGE. FORECAST SOUNDINGS SUGGEST THIS ACTIVITY SHOULD REMAIN ELEVATED GIVEN COOLER/MORE STABLE BOUNDARY LAYER. STEEP MID-LEVEL LAPSE RATES WITH MODERATE ELEVATED INSTABILITY WILL SUPPORT HAIL AS THE PRIMARY THREAT WITH THIS ACTIVITY. SURFACE BASED STORM DEVELOPMENT IS EXPECTED INITIALLY NEAR THE SECONDARY SURFACE LOW/OCCLUSION POINT OVER NWRN MO BY MID-LATE AFTERNOON...AND THEN SWD ACROSS WRN MO TO FAR ERN OK/WRN AR AS THE COLD FRONT MOVES EWD. ALTHOUGH THE WARM SECTOR IS EXPECTED TO BE LOCATED S OF STRONGER FLOW ALOFT...DEEP LAYER SHEAR VECTORS WILL BE SUFFICIENT FOR SUPERCELLS GIVEN THE STRONG INSTABILITY. ANY STORMS THAT DEVELOP/MOVE IN THE VICINITY OF THE OCCLUSION POINT AND WARM FRONT WILL ENCOUNTER STRONG LOW-LEVEL SHEAR /0-3 KM SRH 250-400 M2/S2/ FOR AN ENHANCED TORNADO THREAT...WITH A FEW POTENTIALLY STRONG. LARGE HAIL...SOME VERY LARGE...WILL BE LIKELY ACROSS MUCH OF MO/NRN AR...AND WITH ACTIVITY THAT SPREADS EWD INTO WRN IL THIS EVENING. POTENTIAL EXISTS FOR UPSCALE GROWTH INTO AN MCS THIS EVENING/ OVERNIGHT EWD ACROSS MID MS/LOWER OH VALLEYS. GREATEST SEVERE THREAT SHOULD BE ALONG SWRN PERIPHERY OF THIS MCS ACROSS SERN MO/ NRN-ERN AR AS SECONDARY SURFACE LOW TRACKS TOWARD THE LOWER TN VALLEY. LLJ VEERING TO SWLY AND INCREASING ACROSS AR INTO SRN IL WILL MAINTAIN THREAT FOR TORNADOES THROUGH THIS REGION INTO THE MID-LATE EVENING...IN ADDITION TO LARGE HAIL/DAMAGING WINDS. ...FL NWWD INTO SWRN GA/PARTS OF AL... BOUNDARY WILL EXTEND FROM WRN TN ACROSS AL/SWRN GA. SRN EXTENT IS EXPECTED TO MOVE SWD THROUGH THE NRN-ERN PORTIONS OF THE FL PENINSULA. STRONG SURFACE HEATING ALONG THIS BOUNDARY COMBINED WITH RICH MOISTURE EXPECTED TO SUPPORT MODERATE INSTABILITY. WATER VAPOR IMAGERY INDICATED A WEAK MID-LEVEL IMPULSE CURRENTLY OVER THE ARKLATEX REGION. LARGE SCALE ASCENT WITH THIS FEATURE AS IT TRACKS SEWD TOWARD FL COMBINED WITH STRONG SURFACE HEATING ALONG THE SURFACE BOUNDARY EXPECTED TO SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT. STRONG DEEP LAYER SHEAR WITHIN NW FLOW REGIME SHOULD ALLOW FOR A FEW STRONG TO SEVERE STORMS INTO THE EARLY EVENING. ..PETERS/JEWELL.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 12:56:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 08:56:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181253 SWODY1 SPC AC 181251 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 AM CDT TUE APR 18 2006 VALID 181300Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF MO... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MO VLY...S AND SE INTO AR AND THE TN VLY... ...SYNOPSIS... AN OMEGA BLOCK WILL EVOLVE OVER THE AREA FROM THE RCKYS TO THE WRN ATLANTIC THIS PERIOD AS POTENT SHORTWAVE TROUGH NOW OVER THE NRN HI PLNS MOVES E AND CLOSES OFF OVER SD. CYCLONICALLY CURVED 70-80 KT MID LEVEL JET ROUNDING BASE OF TROUGH WILL SHIFT E/NE ACROSS THE CNTRL PLNS/UPR MS VLY AS A WEAKER...MORE WLY...BAND OF FLOW OVERSPREADS THE SRN PLNS...AR AND THE LWR MS VLY. AT THE SURFACE...STRONG COLD FRONT NOW OVER WRN KS/NEB SHOULD CONTINUE RAPIDLY ESE TODAY...REACHING A DSM/SZL/FYV/MLC LINE BY 00Z WEDNESDAY. AT THE SAME TIME...EXPECT THAT BACK-DOOR TYPE FRONT NOW SETTLING S/SW ACROSS THE OZARKS AND TN VLY WILL BECOME STATIONARY LATER THIS MORNING. SURFACE HEATING AND CONTINUED ELY MOTION OF NRN PLNS TROUGH SHOULD ALLOW BOUNDARY TO MOVE OR MIX NEWD INTO E CNTRL MO/WRN KY AND MIDDLE TN BY LATE AFTERNOON/EARLY EVENING. FARTHER SE...RIDGING OFF THE S ATLANTIC CST EXPECTED TO DRIVE SRN PORTION OF SAME FRONT FARTHER SW ACROSS PARTS OF AL/GA AND FL. ...LWR MO VLY INTO MID MS VLY/LWR TN VLY AND OZARKS... CURRENT DATA SHOW LIGHT ELY SURFACE WINDS CONTINUING TO ADVECT RELATIVELY DRY/COOL AIR FROM GRT LKS RIDGE INTO MO. BUT PROFILER AND VWP WINDS SHOW THAT THE FLOW IS SHALLOW /LESS THAN 1 KM DEEP/. THUS...WITH DAYTIME HEATING...WEAK FRONT NOW STALLED OVER NRN AR SHOULD REDEVELOP NEWD...AND ALLOW SLIGHTLY ELEVATED MOIST LAYER TO MIX TO THE SURFACE. COMBINATION OF LOW LEVEL MOISTURE INFLOW /WITH DEWPOINTS RANGING FROM THE UPR 50S IN NW MO TO PERHAPS THE MID 60S IN S CNTRL AND SERN PARTS OF THE STATE/...SURFACE HEATING AND STEEP MID LEVEL LAPSE RATES SHOULD BOOST AFTERNOON SBCAPE TO AOA 2500 J/KG FROM THE SZL/COU AREA S/SE INTO NRN AR AND FAR W KY AND W TN. STOUT EML CAP LIKELY WILL PROHIBIT SURFACE-BASED STORM DEVELOPMENT IN WARM SECTOR THROUGH MOST OF THE DAY. STORMS WILL...HOWEVER... LIKELY DEVELOP SEWD FROM ERN NEB/FAR WRN IA BY EARLY AFTERNOON AS FORCED ASCENT NEAR POINT OF OCCLUSION BETWEEN EWD-MOVING COLD FRONT AND STATIONARY/WARM FRONT BREACHES CAP. THIS ACTIVITY SHOULD BUILD S/SE INTO NW MO BY MID AFTERNOON AND PRODUCE SEVERE HAIL. FARTHER E/SE...HEATING AND PERSISTENT WARM ADVECTION MAY INITIATE ADDITIONAL STORMS BY LATE IN THE DAY SEWD ALONG WARM/STATIONARY FRONT INTO CNTRL/ERN MO. A RELATIVE WEAKNESS IN THE 700-500 MB FLOW WILL EXIST OVER CNTRL MO TODAY...BETWEEN STRONGER BELTS OF FLOW AIMED TOWARD THE UPR MS VLY AND TN. BUT EVEN WITH MODEST /30 KT/ FLOW IN THAT LAYER...IT APPEARS THAT DEEP SPEED AND DIRECTIONAL SHEAR SHOULD NEVERTHELESS BE ADEQUATE FOR SUSTAINED SUPERCELLS. GIVEN DEGREE OF EXPECTED INSTABILITY...QUALITY OF MOISTURE RETURN AND LIKELIHOOD FOR STRONG HEATING...POTENTIAL WILL THEREFORE EXIST FOR VERY LARGE HAIL AND TORNADOES. THE GREATEST RISK SHOULD FOCUS FROM POINT OF OCCLUSION IN CNTRL MO SEWD ALONG WARM/STATIONARY FRONT. SOMEWHAT LATER TONIGHT...MORE ISOLATED SUPERCELLS MAY DEVELOP SWD ALONG COLD FRONT INTO NRN/WRN AR. W/E BREADTH OF WARM SECTOR AND CONTINUED LOW LEVEL WARM ADVECTION/ MOISTURE INFLOW SUGGEST THAT STORMS WILL CONTINUE TO MOVE/DEVELOP ESE ACROSS THE MID MS/LWR OH AND LWR TN VLYS THROUGH EARLY WEDNESDAY. THE ACTIVITY IN WRN KY AND IN WRN/MIDDLE TN SHOULD REMAIN SURFACE-BASED AND QUASI-DISCRETE. THESE LIKELY WILL POSE A THREAT FOR HAIL AND POSSIBLY AN ISOLATED TORNADO. FARTHER N...A BAND OR TWO OF ELEVATED STORMS COULD PRODUCE MARGINALLY SEVERE HAIL EWD INTO IL/IND AND CNTRL KY. ...SW GA/AL INTO MIDDLE TN TODAY... STRONG SURFACE HEATING WILL OCCUR AHEAD OF SHALLOW FRONT BACK-DOORING WSW INTO AL TODAY. COUPLED WITH RICH MOISTURE AVAILABILITY...FAIRLY STEEP MID LEVEL LAPSE RATES AND 30-40 KT NWLY MID LEVEL FLOW...SETUP COULD SUPPORT DEVELOPMENT OF SCATTERED STRONG TO SEVERE STORMS WITH WIND/HAIL INTO EARLY EVENING. ...ERN TN/ERN KY/WRN NC EARLY WEDNESDAY... ELEVATED STORMS WITH MARGINALLY SEVERE HAIL MAY AFFECT THE CUMBERLAND PLATEAU AND PARTS OF THE SRN APPALACHIANS AFTER 06-09Z WEDNESDAY AS WLY LLJ/ELEVATED MOISTURE INFLOW STRENGTHEN OVER REGION. ..CORFIDI/JEWELL.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 16:30:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 12:30:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181622 SWODY1 SPC AC 181620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CDT TUE APR 18 2006 VALID 181630Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF MO... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO RIVER VALLEY INTO CENTRAL TX AND ERN AL/WRN GA.... ...MID MO RIVER VALLEY INTO THE LOWER OH RIVER VALLEY... SURFACE LOW WAS LOCATED OVER NEB NEAR BIE AT 16Z WITH SEWD EXTENDING WARM FRONT STILL TAKING SHAPE ALONG THE LOWER MO RIVER VALLEY. COLD FRONT TRAILING THE LOW CENTER WAS ADVANCING QUICKLY SEWD ACROSS CENTRAL KS/NWRN OK...AND WILL CONTINUE INTO THE OZARKS/WRN MO BY THE LATE AFTERNOON. MODELS ARE FAIRLY CONSISTENT WITH SURFACE FEATURES TODAY...DEVELOPING A LOW CENTER SEWD ALONG THE TRIPLE POINT INTO NWRN/CENTRAL MO BY 00Z AND INTO FAR WRN KY BY THE END OF THE PERIOD. LOW LEVEL MOISTURE FIELDS ARE MUCH HIGHER TODAY THAN WITH THE PAST SEVERAL SYSTEMS /I.E. H85 DEW POINTS AOA 10C AND SURFACE DEW POINTS IN THE MID 60S F OVER ERN OK/AR /. EXPECT MID/UPPER 60F SURFACE DEW POINTS WILL SURVIVE MIXING WITH AN AXIS EXTENDING INTO NWRN/CENTRAL MO BY THE LATE AFTERNOON. UNLIKE THE PREVIOUS SEVERE WEATHER EVENTS OVER THE PAST FEW WEEKS...LARGE SCALE ASCENT WILL NOT BECOME MAXIMIZED INTO THE WARM SECTOR TODAY AS OF NOSE STRONG MID/UPPER LEVEL JET LAGS WWD BEHIND THE SURFACE COLD FRONT. HOWEVER...VERY STEEP LAPSE RATES AND UNSEASONABLY WARM/MOIST BOUNDARY LAYER WILL SUPPORT A STRONGLY UNSTABLE WARM SECTOR BY THE MID AFTERNOON. IN ADDITION...SURFACE CONVERGENCE WILL BECOME MAXIMIZED INTO THE LOWER MO RIVER VALLEY AS TRIPLE POINT DEVELOPS SEWD. GIVEN THE MORE LIMITED LARGE SCALE ASCENT TODAY...EXPECT HEATING AND CONVERGENCE WILL BE NEEDED TO BREAK STRONG CAP WITH THUNDERSTORM DEVELOPMENT POSSIBLY DELAYED UNTIL LATE IN THE DAY. EXCEPTION WILL BE INTO IA WHERE STRONGER FORCING WILL OVERSPREAD MARGINAL...ELEVATED INSTABILITY NORTH OF THE WARM FRONT TODAY. HERE...THUNDERSTORMS SHOULD INCREASE AND SPREAD A THREAT OF LARGE HAIL NNEWD INTO THE EVENING. MODELS ARE MOST CONSISTENT WITH DEVELOPING PRIMARY SEVERE THREAT BETWEEN 21Z-00Z NEAR THE LOW CENTER OVER NWRN MO AND ALONG COLD FRONT INTO PORTIONS OF SWRN/S-CENTRAL MO. ACTIVITY WILL INCREASE IN SEVERITY AND COVERAGE AS STRONGEST ASCENT FINALLY CATCHES UP WITH THE WARM SECTOR INTO THE MID MS/LOWER OH RIVER VALLEYS THROUGH THE EVENING. DEEP LAYER SHEAR IS NOT FORECAST TO BE OVERLY IMPRESSIVE /35-45 KT OF SFC-6 KM SHEAR/ THOUGH WILL STILL BE ADEQUATE FOR SUPERCELLS GIVEN AMOUNT OF INSTABILITY AND STRONG PRESSURE FALLS AHEAD OF APPROACHING UPPER LOW/WARM FRONT. BACKED SURFACE WINDS SHOULD SUPPORT 0-1 KM SRH IN EXCESS OF 150 M2/S2 WITH AN INCREASED THREAT OF TORNADOES THROUGH THE EVENING OVER CENTRAL AND SERN MO. EXPECT DEVELOPMENT WILL BUILD/ORGANIZE INTO A MCS WHICH MAY CONSOLIDATE SUFFICIENTLY INTO A BOW ECHO/QUASI-LINEAR SYSTEM RACING SEWD ALONG THE WARM FRONT INTO THE MID SOUTH/LOWER OH RIVER VALLEY AFTER DARK. WIND DAMAGE MIGHT BECOME PREVALENT WITH THIS ACTIVITY...THOUGH A TORNADO THREAT WILL ALSO REMAIN AS STRONG PRESSURE FALLS PRECEDE THIS ACTIVITY. MCS MAY CONTINUE ESEWD ACROSS THE TN VALLEY LATER TODAY. ...FAR ERN OK/AR INTO CENTRAL TX... THUNDERSTORM DEVELOPMENT WILL BE MORE ISOLATED ALONG THE COLD FRONT GIVEN STRENGTH OF CAPPING TODAY. HOWEVER...AIR MASS WILL BECOME MODERATELY UNSTABLE AND REMAIN UNDER MODEST WLY MID LEVEL FLOW FOR 35-45 KT OF EFFECTIVE BULK-SHEAR. CINH WILL WEAKEN LATER THIS AFTERNOON AS HIGH TEMPERATURES REACH WELL INTO 90S F. THUS...CONVERGENCE ALONG COLD FRONT AND AMOUNT OF SHEAR WILL BE CAPABLE OF SUPPORTING ISOLATED SEVERE THUNDERSTORMS INTO THE EARLY/MID EVENING FROM CENTRAL TX INTO WRN/CENTRAL AR. ...TN RIVER VALLEY INTO SERN AL/SWRN GA... SURFACE FRONT WILL STALL IN A NNW-SSE ORIENTATION FROM THE ERN FL PANHANDLE INTO MIDDLE TN. STRONG AFTERNOON HEATING AND PRESENCE OF UPPER 60F SURFACE DEW POINTS SHOULD SUPPORT A VERY UNSTABLE AIR MASS WEST OF THIS FRONT. IN ADDITION...NWLY FLOW ALOFT WILL REMAIN SUFFICIENT FOR 30-40 KT OF DEEP LAYER SHEAR PARALLELING THE STALLED SURFACE FRONT. REGION WILL REMAIN UNDER/AHEAD OF SHORTWAVE RIDGING ALOFT AND LIMIT THUNDERSTORM POTENTIAL/COVERAGE ALONG THE FRONT. HOWEVER...FORECAST SOUNDINGS REMAIN MORE THAN SUFFICIENT FOR ORGANIZED MULTICELLS AND ISOLATED SUPERCELLS SHOULD HEATING/CONVERGENCE INITIATE STORMS. ANY SEVERE THREAT EXPECTED TO BE DIURNALLY-DRIVEN AND DIMINISH BY THE MID EVENING. ..EVANS/CROSBIE.. 04/18/2006  From SwoDy1 at goshenarc.org Wed Apr 19 01:05:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 21:05:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190102 SWODY1 SPC AC 190101 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0801 PM CDT TUE APR 18 2006 VALID 190100Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL/SRN MO THRU EXTREME SRN IL...WRN KY AND WRN TN...AND NE AR... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA...FROM THE MID MS VLY INTO THE ERN GULF STATES...AND ACROSS PARTS OF THE SRN PLAINS... ...LOWER MO VALLEY INTO PARTS OF LOWER OH/TN VALLEYS... MID/UPPER LEVEL TROUGH IS EXPECTED TO INTENSIFY FAIRLY RAPIDLY /UP TO 80 METERS/12 HOUR HEIGHT FALLS WITHIN CENTER OF CIRCULATION/ OVERNIGHT AS IT EVOLVES INTO A DEEP CLOSED LOW OVER CENTRAL SD BY 12Z WEDNESDAY. EARLY EVENING SURFACE ANALYSIS SHOWED A COLD FRONT ADVANCING EWD THROUGH WRN MO AND ERN OK...WITH OCCLUSION POINT OF THE COLD FRONT/ WARM FRONT OVER NWRN MO. THE WARM FRONT STRETCHED SEWD TO SERN MO AND THEN INTO MIDDLE TN...WHERE IT BECOMES QUASI-STATIONARY EXTENDING S/SEWD INTO NWRN-SRN FL. MEANWHILE... AN OCCLUDED FRONT EXTENDED NNWWD FROM NWRN MO ACROSS WRN IA TO THE OCCLUDED SURFACE LOW OVER SOUTH CENTRAL ND. SUPERCELLS DEVELOPED DURING THE LATE AFTERNOON AT THE OCCLUSION POINT OVER NWRN MO. ALTHOUGH HEIGHT FALLS SHOULD NOT BE TOO STRONG S OF MID-LEVEL JET AXIS...FORCING WITH PROGRESSIVE COLD FRONT AND MODERATELY UNSTABLE AIR MASS WILL SUPPORT ADDITIONAL STORMS ACROSS MO/AR INTO LOWER OH/TN VALLEYS AS OCCLUSION POINT TRACKS TOWARD THE SSE REACHING WRN KY BY 12Z. STRONG DEEP LAYER SHEAR FAVORS ADDITIONAL SUPERCELLS...WITH THREAT FOR TORNADOES GREATEST IN VICINITY OF OCCLUDED POINT AND ALONG WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE ENHANCED BY BACKED LOW-LEVEL WINDS. STRENGTHENING/VEERING LLJ FROM AR INTO LOWER OH VALLEY SHOULD ALSO SUPPORT LARGER HODOGRAPHS FOR CONTINUED TORNADO POTENTIAL REACHING WRN KY/WRN TN LATER TONIGHT/EARLY WEDNESDAY MORNING. THIS LATTER SEVERE THREAT IS EXPECTED TO BE ALONG THE SRN PERIPHERY OF AN EWD MOVING MCS SPREADING INTO THE LOWER OH AND TN VALLEYS...WHERE AVAILABLE INSTABILITY WILL REMAIN THE GREATEST. LARGE HAIL/DAMAGING WINDS WILL CONTINUE TO BE A THREAT AS WELL GIVEN FAVORABLE THERMODYNAMICS...WITH HAIL BEING THE PRIMARY THREATS NE OF WARM FRONT INTO MUCH OF IL TO SRN IND WHERE ACTIVITY WILL BE ELEVATED. ...TX... ONGOING CLUSTER OF STRONG/SEVERE STORMS ACROSS CENTRAL TX TO THE NW AND N OF SAT-AUS IS BEING AIDED BY LARGE SCALE ASCENT WITH WEAK MID-LEVEL IMPULSE MOVING NEWD ACROSS REGION. GIVEN THAT STORM INITIATION WAS ALSO TIED TO STRONG SURFACE HEATING WITHIN DEEPLY MIXED ENVIRONMENT...LOSS OF INSOLATION SHOULD ALLOW FOR EVENTUAL DECREASE IN NEW ACTIVITY LATER THIS EVENING. UNTIL THEN...LARGE HAIL AND DAMAGING WINDS WILL REMAIN POSSIBLE. ...UPPER MS VALLEY... STRONG HEIGHT FALLS AHEAD OF THIS UPPER FEATURE WILL DEVELOP/ SPREAD ACROSS THE UPPER MS VALLEY AND IA TO NRN IL. THIS COMBINED WITH STRONG LOW-LEVEL WAA SHOULD MAINTAIN PRIMARILY ELEVATED THUNDERSTORMS ALONG/E OF OCCLUDED FRONT...WHERE WEAK INSTABILITY AND EFFECTIVE DEEP LAYER SHEAR SHOULD SUPPORT GENERALLY MARGINALLY SEVERE HAIL. HIGHER INSTABILITY VALUES...BUT STILL ELEVATED...SWD INTO IA/IL MAY ALLOW FOR LOCALLY LARGER HAIL WITH THE STRONGEST ACTIVITY. ...ERN AL/WRN-SWRN GA TO NRN FL... ALTHOUGH DEEP LAYER SHEAR REMAINS SUPPORTIVE OF ORGANIZED STORMS...A CONTINUED DIMINISHING TREND IN SEVERE STORM POTENTIAL IS EXPECTED WITH THE LOSS OF DAYTIME HEATING STABILIZING THE AIR MASS. UNTIL ABOUT 03Z...A FEW STRONGER STORMS WILL BE CAPABLE OF PRODUCING ISOLATED HAIL/STRONG WIND GUSTS. ..PETERS.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 06:13:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 02:13:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190607 SWODY1 SPC AC 190605 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0105 AM CDT WED APR 19 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TX HILL COUNTRY/EDWARDS PLATEAU EWD TO THE UPPER TN VALLEY/SERN STATES... ...SYNOPSIS... LARGE CUT-OFF MID/UPPER LEVEL LOW INITIALLY LOCATED OVER THE NRN PLAINS WILL WEAKEN SLIGHTLY TODAY AS OMEGA BLOCK SHIFTS SLIGHTLY EWD. BY THE END OF THE PERIOD...MODELS CONTINUE TO INDICATE LARGE SCALE PATTERN EVOLVING INTO MORE OF A REX BLOCK FROM THE NRN PLAINS/UPPER MS VALLEY CLOSED LOW NNEWD INTO HUDSON BAY REGION. MEANWHILE...WATER VAPOR IMAGERY INDICATED A SERIES OF MAINLY WEAK MID-LEVEL IMPULSES TRAVERSING SRN STREAM FLOW FROM SRN BAJA/NRN MEXICO ENEWD TO THE LOWER MS VALLEY...AND THEN TURNING E/SELY ACROSS MS/AL INTO SERN STATES. FARTHER W...A SHORT WAVE TROUGH CURRENTLY MOVING INTO SRN CA WILL MOVE EWD REACHING AZ/NM BY 12Z THURSDAY. IN THE LOW-LEVELS...SURFACE LOW IS EXPECTED SLOWLY FILL AS IT MOVES EWD ACROSS KY THIS FORECAST PERIOD. COLD FRONTAL SURGE IS EXPECTED TO SLOW TODAY AS THIS BOUNDARY BECOMES ORIENTED PARALLEL TO THE SRN BRANCH OF THE WESTERLIES. ...OH/TN VALLEYS INTO THE SERN STATES... CLUSTER OF THUNDERSTORMS/MCS IS EXPECTED TO BE ONGOING AT START OF PERIOD ACROSS PARTS OF LOWER OH/UPPER TN VALLEYS AND SRN APPALACHIANS. WAA REGIME PER WLY LLJ VEERING TO WNWLY ACROSS THE SERN STATES IS EXPECTED TO SUPPORT DOWNSTREAM DESTABILIZATION TO MAINTAIN THIS ACTIVITY ACROSS WRN NC/SC/GA THIS MORNING AND AFTERNOON...WITH ATTENDANT THREATS OF DAMAGING WINDS AND HAIL. POTENTIAL OUTFLOW BOUNDARY FROM THIS COMPLEX AND/OR ZONE OF DIFFERENTIAL HEATING EXPECTED ACROSS GA ALONG WRN PERIPHERY OF CLOUD SHIELD SHOULD RE-ENFORCE RESIDUAL BOUNDARY DRAPED SEWD ACROSS THIS AREA INTO FL. SURFACE HEATING EXPECTED IN THE WAKE OF THIS INITIAL ACTIVITY COMBINED WITH SURFACE DEWPOINTS IN THE MID 60S AND STEEP MID-LEVEL LAPSE RATES SHOULD RESULT IN MUCAPES OF 2000-3000 J/KG EXTENDING FROM THE SURFACE LOW INTO ERN AL/GA. LARGE SCALE ASCENT WITH A MID-LEVEL IMPULSE...CURRENTLY MOVING THROUGH THE ARKLATEX REGION...IS EXPECTED TO TRANSLATE SEWD ACROSS ERN GULF COAST STATES AIDING IN THUNDERSTORM DEVELOPMENT ALONG THE SE-NW ORIENTED SURFACE BOUNDARY THIS AFTERNOON. STRONG DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS/SUPERCELLS WITH ATTENDANT THREAT OF HAIL/ DAMAGING WINDS AND PERHAPS A COUPLE OF TORNADOES. ...TX HILL COUNTRY/EDWARDS PLATEAU TO NERN TX/LOWER MS VALLEY... 40 KT OF SWLY MID-LEVEL FLOW IS EXPECTED TO EXTEND FROM SWRN TX AND THE TX HILL COUNTRY TO AR/LOWER TN VALLEY. BY EARLY AFTERNOON...COLD FRONT SHOULD EXTEND FROM MIDDLE TN/NRN MS WSWWD INTO NERN TX AND THEN TO THE RIO GRANDE VALLEY NEAR DRT. MODERATE INSTABILITY IS EXPECTED ALONG/S OF THIS BOUNDARY...GIVEN STRONG SURFACE HEATING WITHIN A MOIST AIR MASS AND BENEATH STEEP MID-LEVEL LAPSE RATES. MUCH OF THE STRONGER FLOW ALOFT IS PROGGED TO BE OVER THE POST-FRONTAL AIR MASS RESULTING IN RATHER WEAK DEEP LAYER SHEAR ACROSS PARTS OF THE LOWER MS VALLEY THIS AFTERNOON...LIMITING STORM ORGANIZATION. AN EXCEPTION SHOULD BE FARTHER SW ACROSS THE TX HILL COUNTRY WHERE THE STRONG FLOW ALOFT WILL SUPPORT FAVORABLE DEEP LAYER SHEAR FOR ORGANIZED STORMS. ANY STORMS THAT DEVELOP OVER THIS REGION WILL BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE N/NEWD FROM THE TX HILL COUNTRY INTO PARTS OF CENTRAL TO NERN TX AND PERHAPS INTO SRN AR/NRN LA AS ISENTROPIC ASCENT INCREASES N OF SURFACE BOUNDARY LATER THIS EVENING/TONIGHT. STRENGTHENING SWLY MID-LEVEL WINDS AHEAD OF SWRN STATES SHORT WAVE TROUGH ARE EXPECTED TO RESULT IN SUFFICIENT EFFECTIVE DEEP LAYER SHEAR FOR SOME STORM ORGANIZATION GIVEN MODERATE INSTABILITY. HAIL WOULD BE THE PRIMARY THREAT WITH THE OVERNIGHT ACTIVITY. ..PETERS/JEWELL.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 13:01:52 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 09:01:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191258 SWODY1 SPC AC 191256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED APR 19 2006 VALID 191300Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM S CNTRL TX THROUGH THE LWR MS VLY TO SRN APLCNS... ...SYNOPSIS... OMEGA BLOCK WILL PROGRESS SLOWLY E ACROSS THE CNTRL/ERN U.S. THIS PERIOD AS SRN CA UPR VORT CONTINUES E TOWARD THE FOUR CORNERS. AT THE SURFACE...COLD FRONT ASSOCIATED WITH NRN PLNS LOW EXPECTED TO BECOME MORE OR LESS STATIONARY FROM S CNTRL TX E/NE ACROSS SRN AR INTO THE UPR TN VLY. A BIT FARTHER S AND E...WEAK BACK-DOOR BOUNDARY THAT MOVED INTO AL YESTERDAY SHOULD RETREAT E ACROSS GA TODAY IN RESPONSE TO WLY LLJ AND SURFACE WAVE MOVING E ACROSS TN. ...UPR TN VLY INTO GA/WRN CAROLINAS... RESIDUAL WLY LLJ WILL IMPINGE UPON RETREATING BACK-DOOR FRONT OVER THE SRN APPALACHIAN REGION TODAY. LARGE SCALE FORCING FOR ASCENT WILL BE WEAK OVER THE AREA AS HEIGHTS SLIGHTLY REBOUND WITH THE CONTINUED PROGRESSION OF AFOREMENTIONED OMEGA PATTERN. BUT COMBINATION OF SURFACE HEATING...UPSLOPE COMPONENTS AND CONVERGENCE ALONG FRONT AN/OR OUTFLOW FROM OVERNIGHT CONVECTION LIKELY TO RESULT IN RENEWED AND/OR STRENGTHENED STORM DEVELOPMENT OVER PARTS OF SE TN/NRN AL/GA AND THE WRN CAROLINAS BY MIDDAY. HEATING BENEATH RESIDUAL EML SHOULD YIELD SBCAPE AOA 2000 J/KG W OF BACK-DOOR FRONT IN SRN TN/AL AND WRN GA...WITH VALUES DECREASING TO AROUND 1000 J/KG IN THE WRN CAROLINAS. COUPLED WITH DEEP NWLY SHEAR OF 35-40 KTS ORIENTED ROUGHLY PARALLEL BACK-DOOR BOUNDARY...SETUP MAY SUPPORT A FEW SUPERCELLS WITH HAIL AND POSSIBLY A COUPLE TORNADOES IN GA AND THE WRN CAROLINAS. FARTHER W...DEEP SHEAR LIKELY WILL BE ORIENTED MORE PERPENDICULAR TO COMPOSITE STORM OUTFLOW BOUNDARY IN TN. COUPLED WITH STEEP LOW TO MID LEVEL LAPSE RATES /PER BHM 12Z RAOB/...POSSIBILITY WILL BE GREATER FOR A FORWARD-PROPAGATING MCS/SQUALL LINE. EMBEDDED BOWS MAY YIELD BOTH HIGH WIND AND HAIL. ALL OF THE STORMS IN THIS REGION SHOULD BE STRONGLY DIURNAL...WITH LITTLE IF ANY SEVERE THREAT CONTINUING INTO THE NIGHT. ...S CNTRL TX INTO THE ARKLATEX AND THE LWR MS VLY... STALLING COLD FRONT WILL BE FOCUS OF TSTM DEVELOPMENT LATE TODAY INTO TONIGHT FROM S CNTRL TX NEWD INTO THE ARKLATEX AND THE LWR MS VLY. BY EARLY AFTERNOON...FRONT SHOULD EXTEND FROM MIDDLE TN/NRN MS WSWWD INTO NERN TX AND THEN TO THE RIO GRANDE NEAR DRT. MODERATE INSTABILITY /SBCAPE 0F 1500-2000 J PER KG/ WILL DEVELOP ALONG/S OF THE BOUNDARY GIVEN STRONG HEATING...MOIST PREFRONTAL AIR MASS AND STEEP MID-LEVEL LAPSE RATES. 30-40 KT SWLY MID-LEVEL FLOW ROUGHLY PARALLEL TO FRONT WILL EXTEND FROM S CNTRL TX INTO AR AND THE LWR MS VLY. THE STRONGEST FLOW ALOFT OVER THE TN VLY SHOULD REMAIN IN THE POST-FRONTAL ENVIRONMENT. THIS SHOULD LIMIT DURATION/ORGANIZATION OF ANY STORMS THAT DO FORM OVER THAT REGION IN WAKE OF ON-GOING MORNING STORMS. HOWEVER...GIVEN DEGREE OF AFTERNOON CAPE /AROUND 2000 J PER KG/...A CONDITIONAL THREAT WILL EXIST FOR A FEW SPOTS OF SEVERE HAIL/LOCALLY DAMAGING WIND THROUGH EARLY EVENING. FARTHER SW...SOMEWHAT GREATER DEEP WSWLY SHEAR WILL BE PRESENT INVOF FRONT FROM THE ARKLATEX REGION SW TO THE TX BIG BEND. COMBINATION OF STRONG SURFACE HEATING AND FRONTAL UPLIFT MAY INITIATE MORE ORGANIZED STORMS/SUPERCELLS. GIVEN FAIRLY RICH BOUNDARY LAYER MOISTURE AND STEEP MID LEVEL LAPSE RATES...THIS ACTIVITY WILL BE CAPABLE OF LARGE HAIL AND DAMAGING WIND. STORM COVERAGE EXPECTED TO INCREASE FROM THE TX HILL COUNTRY N/NE INTO PARTS OF CNTRL/NE TX TONIGHT...AND ACROSS SRN AR/NRN LA EARLY THURSDAY...AS ISENTROPIC ASCENT INCREASES N OF STALLED FRONT. STRENGTHENING SWLY MID-LEVEL WIND FIELD AHEAD OF CA SHORTWAVE IMPULSE WILL YIELD SUFFICIENT CLOUD LAYER SHEAR FOR ELEVATED STORMS/POSSIBLE SUPERCELLS WITH HAIL AND HEAVY RAIN. OTHER ELEVATED STORMS/POSSIBLE SUPERCELLS WITH HAIL MAY FORM VERY LATE IN THE PERIOD OVER THE PERMIAN BASIN OF W TX...IN AREA OF RAPID MOISTURE INFLUX/UPR DIVERGENCE AHEAD SAME UPR DISTURBANCE. ...WRN/CNTRL WI... A SMALL AREA WITH THE POTENTIAL FOR NON-SUPERCELL FUNNELS MAY EVOLVE INVOF OLD OCCLUSION MOVING NE ACROSS THE UPR MS VLY THIS AFTERNOON. STEEP LOW LEVEL LAPSE RATE PLUME WILL BE ADJACENT TO BOUNDARY LAYER MOISTURE/VERTICAL VORTICITY AXIS NEAR SURFACE OCCLUSION...AND MAY YIELD A BRIEF SPINUP OR TWO FOLLOWING MAX HEATING. ..CORFIDI/JEWELL.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 16:21:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 12:21:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191617 SWODY1 SPC AC 191616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 AM CDT WED APR 19 2006 VALID 191630Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A BROAD AREA EXTENDING FROM WRN TX INTO THE LOWER MS/TN RIVER VALLEYS AND SOUTHEASTERN U.S.... ...LOWER MS/TN RIVER VALLEYS ACROSS THE SOUTHEAST... WRN REMNANTS OF OVERNIGHT MCS CONTINUE TO INTENSIFY WITHIN FEED OF VERY UNSTABLE AIR AND STEEP LAPSE RATES IN PLACE OVER THE GULF COAST STATES. BROAD WAA-INDUCED THUNDERSTORM AREA ACROSS SC WILL REINFORCE SURFACE OUTFLOW BOUNDARY EXTENDING FROM THE SAV AREA NWWD TO NEAR ATL AND THEN INTO MIDDLE TN. A LOW CENTER IS EXPECTED TO REMAIN NEAR THE TRIPLE POINT OF THIS FEATURE AND SURFACE COLD FRONT SHIFTING SLOWLY SEWD ACROSS MIDDLE TN TODAY. SW OF THE LOW...THE COLD FRONT IS EXPECTED TO STALL AND BECOME STATIONARY ACROSS SRN AR INTO THE BIG BEND REGION OF TX THROUGH THE DAY. IN ADDITION...A WEAK MID LEVEL IMPULSE SUSTAINING THE MCS NOW MOVING ACROSS THE SRN APPALACHIANS WILL CONTINUE SEWD AND MOVE OFF THE SC/GA COAST BY THE EARLY EVENING. STRONG TO OCCASIONALLY SEVERE STORMS...PRIMARILY ELEVATED TO THE NORTH/EAST OF SURFACE OUTFLOW BOUNDARY...EXPECTED TO MAINTAIN MARGINALLY SEVERE HAIL AND PERHAPS ISOLATED DAMAGING WIND ACROSS THE SAVANNA RIVER VALLEY AND MUCH OF SC THROUGH THE DAY. MORE INTENSE STORMS WILL STRADDLE THE OUTFLOW BOUNDARY WHERE NWLY MID LEVEL FLOW AND FEED OF STRONGLY UNSTABLE AIR WILL INCREASE THE SEVERE THREAT FROM NRN/ERN AL INTO CENTRAL/SRN GA THIS AFTERNOON. DEEP LAYER SHEAR WILL BE SUFFICIENT FOR ORGANIZED LINES/SUPERCELLS WITH THESE STORMS...ENHANCING THE THREAT OF VERY LARGE HAIL AND DAMAGING WINDS. ISOLATED TORNADOES MAY ALSO ACCOMPANY STRONGER STORMS...ESPECIALLY NEAR THE NW-SE ORIENTED SURFACE BOUNDARY. THIS ACTIVITY MAY SPREAD INTO NRN FL/SERN GA BEFORE DIMINISHING/MOVING OFFSHORE EARLY THIS EVENING. FARTHER WEST AND NORTHWEST...WEAK MID LEVEL SHORTWAVE TROUGH EVIDENT ON WV IMAGERY MOVING ACROSS THE LOWER MS RIVER VALLEY MAY AGITATE THE WARM SECTOR SUFFICIENTLY FOR INCREASING MOIST CONVECTION THROUGH THE DAY INTO PORTIONS OF NRN MS/WRN AND MIDDLE TN INTO CENTRAL AL. SEVERE POTENTIAL IS A BIT MORE CONDITIONAL ACROSS THIS REGION. THOUGH SHEAR WILL REMAIN MARGINAL ACROSS THIS REGION...ESPECIALLY BELOW 5-6 KM...ANY INTENSE CORES WITHIN VERY STEEP LAPSE RATES AND STRONG INSTABILITY WILL SUSTAIN A THREAT OF LARGE HAIL AND DAMAGING WINDS INTO THE EARLY EVENING. ...ARKLATEX INTO WRN/CENTRAL TX... CONVERGENCE WILL REMAIN FOCUSED ALONG STALLED SURFACE FRONT TODAY FROM THE BIG BEND REGION OF TX INTO THE LOWER MS RIVER VALLEY. THOUGH LARGE SCALE ASCENT WILL REMAIN WEAK/ABSENT...WARM SECTOR WILL BECOME VERY UNSTABLE AND WEAKLY CAPPED DURING THE MID TO LATE AFTERNOON. THEREFORE...EXPECT AT LEAST A FEW CLUSTERS OF INTENSE THUNDERSTORMS WILL FORM ALONG THE BOUNDARY AND PERSIST INTO THE MID EVENING. FORECAST SOUNDINGS MAINTAIN 35-40 KT OF EFFECTIVE SHEAR...SUGGESTING ACTIVITY WILL ORGANIZE INTO MULTICELL LINES/CLUSTERS AND SUPERCELLS. LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED WITH ANY DEVELOPMENT ACROSS THIS REGION LATER TODAY AND THIS EVENING. MOST LIKELY AREA WILL BE INTO THE BIG BEND REGION WHERE TERRAIN WILL AID IN INITIATION...POSSIBLY BY 21Z. VERY LARGE HAIL WILL BE COMMON ACROSS THIS REGION. DEVELOPMENT HERE MAY SPREAD NNEWD ALONG AND NORTH OF THE FRONT SPREADING THREATS OF LARGE HAIL AND ISOLATED DAMAGING WIND INTO N-CENTRAL/NERN TX THROUGH THE EVENING. LATER TONIGHT...INCREASING LARGE SCALE ASCENT ATOP STABLE BOUNDARY LAYER NORTH OF STALLED FRONT WILL OVERSPREAD THE PERMIAN BASIN REGION. SREF AND GFS GUIDANCE BOTH EXPECT ELEVATED THUNDERSTORM DEVELOPMENT INTO THIS REGION WHERE FORECAST SOUNDINGS YIELD MODERATE MUCAPE AND SUFFICIENT EFFECTIVE SHEAR FOR ROTATING UPDRAFTS. THUS...LARGE HAIL WOULD ACCOMPANY STORMS IN THIS REGION WITH ACTIVITY POSSIBLY SPREADING TOWARD CENTRAL TX BY DAY BREAK THURSDAY MORNING. ..EVANS\CROSBIE.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 19:55:11 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 15:55:11 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191951 SWODY1 SPC AC 191949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0249 PM CDT WED APR 19 2006 VALID 192000Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND TONIGHT ACROSS MUCH OF TX THROUGH THE EASTERN GULF STATES.... BLOCK REMAINS ESTABLISHED IN BELT OF FLOW EXTENDING ACROSS THE NORTH CENTRAL U.S. INTO THE WESTERN ATLANTIC. MODELS SUGGEST DEEP CLOSED LOW OFF THE NORTH ATLANTIC COAST WILL MOVE LITTLE THROUGH LATE TONIGHT...BUT HIGH CENTER MAY BEGIN TO WEAKEN OVER EASTERN ONTARIO AS UPSTREAM CLOSED LOW GRADUALLY SHIFTS EAST OF THE DAKOTAS INTO THE UPPER MISSISSIPPI VALLEY. THIS IS EXPECTED MOSTLY IN RESPONSE TO A SIGNIFICANT IMPULSE PIVOTING AROUND ITS SOUTHERN/EASTERN PERIPHERY. AMPLIFYING UPSTREAM TROUGH OVER THE EASTERN PACIFIC WILL REMAIN WELL OFFSHORE...BUT MAY BE RESPONSIBLE FOR FORCING CONTINUED EASTWARD ACCELERATION OF CLOSED LOW/TROUGH ACROSS THE SOUTHERN PLATEAU LATE THIS AFTERNOON AND TONIGHT. THIS IMPULSE APPEARS TO BE PRECEDED BY ANOTHER WEAKER SHORT WAVE TROUGH...WHICH IS PROGGED TO LIFT ACROSS THE TEXAS BIG BEND REGION THROUGH THE ARKLATEX BY 12Z THURSDAY. ...TENNESSEE VALLEY/GULF STATES... A BROAD WEAK SURFACE LOW...ROUGHLY NEAR INTERSECTION OF CONVECTIVE OUTFLOW BOUNDARY AND SLOWLY ADVANCING COLD FRONT...NOW APPEARS CENTERED ACROSS NORTHWEST ALABAMA/SOUTHERN MIDDLE TENNESSEE. THIS FEATURE HAS BECOME FOCUS FOR STRONGEST DESTABILIZATION...WHICH SEEMS LIKELY TO LEAD TO FURTHER VIGOROUS CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON. LATEST OBJECTIVE ANALYSIS SUGGESTS MIXED LAYER CAPE IS NOW IN EXCESS OF 3000 J/KG ALONG/SOUTH OF THE BOUNDARIES...ACROSS MUCH OF NORTHERN MISSISSIPPI/NORTHERN ALABAMA INTO WEST CENTRAL GEORGIA. THIS IS BENEATH 30 TO 40 KT WESTERLY MID-LEVEL FLOW...WHICH IS CONTRIBUTING TO SUFFICIENT SHEAR FOR SUPERCELLS. MID/UPPER FORCING IS UNCERTAIN...BUT CAPPING APPEARS WEAK ENOUGH TO ALLOW FOR CONTINUED RAPID DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON WITH ADDITIONAL HEATING AND PERSISTENT LOW-LEVEL CONVERGENCE. LARGE CONVECTIVE CLUSTER MAY EVENTUALLY EVOLVE...AND DEVELOP EAST SOUTHEASTWARD THROUGH THE EASTERN GULF STATES. THIS WILL BE ACCOMPANIED BY A RISK FOR DAMAGING WINDS AND HAIL...SOME OF WHICH MAY BECOME QUITE LARGE...THROUGH EARLY EVENING. ...TEXAS... LEAD IMPULSE IS ALREADY SUPPORTING VIGOROUS CONVECTIVE DEVELOPMENT SOUTH OF THE TEXAS BIG BEND...AND ACTIVITY MAY EVENTUALLY DEVELOP ALONG SURFACE FRONT SOUTH OF DEL RIO INTO THE SAN ANTONIO AREA ONCE CAP WEAKENS. IF THIS OCCURS...VEERING LOW-LEVEL WIND FIELDS WITH HEIGHT BENEATH MODERATE WEST SOUTHWESTERLY MID/UPPER FLOW WILL BE SUFFICIENT FOR SUPERCELLS IN ENVIRONMENT WITH MIXED LAYER CAPE IN EXCESS OF 2000 J/KG. THIS ACTIVITY MAY DIMINISH DURING THE EVENING AS INHIBITION INCREASES WITH LOSS OF SURFACE HEATING...BUT WARM ADVECTION NORTH OF FRONT IS EXPECTED TO SUPPORT INCREASING THUNDERSTORMS ACROSS CENTRAL INTO NORTHEAST TEXAS. CAPE FOR PARCELS BASED IN MOIST LAYER ABOVE FRONTAL INVERSION IS EXPECTED TO BE MORE THAN SUFFICIENT TO SUPPORT A LARGE HAIL THREAT. ...LWR OH VLY THROUGH UPPER GREAT LAKES... FORCING ALONG WHAT IS LEFT OF OCCLUDED SURFACE FRONT IS ALREADY SUPPORTING AN INCREASE IN THUNDERSTORMS ACROSS PARTS OF CENTRAL/ EASTERN WISCONSIN. ADDITIONAL ACTIVITY APPEARS POSSIBLE LATER THIS AFTER AND EARLY EVENING...SOUTHWARD INTO PARTS OF ILLINOIS AND INDIANA...WHERE SHEAR MAY CONTINUE TO BECOME MORE FAVORABLE FOR UPDRAFT ROTATION. HOWEVER...OVERALL CONVECTIVE POTENTIAL/ SEVERE THREAT SEEMS LIKELY TO REMAIN LIMITED DUE TO LACK OF MORE FAVORABLE DESTABILIZATION. ..KERR.. 04/19/2006  From SwoDy1 at goshenarc.org Thu Apr 20 01:16:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 21:16:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200111 SWODY1 SPC AC 200109 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0809 PM CDT WED APR 19 2006 VALID 200100Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX...ARKLATEX...ACROSS THE LOWER MS VALLEY TO NRN FL... ...SYNOPSIS... OCCLUDED DEEP LAYER CYCLONE RESIDES ACROSS THE NRN PLAINS THIS EVENING WITH EXTENSIVE FRONTAL ZONE ARCING FROM WRN LAKE SUPERIOR SWD TO THE LOWER MS VALLEY...AND THEN SWWD ACROSS THE ARKLATEX TO THE BIG BEND. OCCLUDED NRN SEGMENT OF THE FRONT EXTENDS FROM THE GREAT LAKES TO WRN TN. A WARM FRONT EXTENDS SEWD ACROSS THE TN VALLEY AND HAS BEEN STRONGLY REINFORCED BY CONVECTIVE OUTFLOW FROM AN ACTIVE MCS OVER NRN AL. MORE WIDELY SCATTERED TSTMS EXIST ALONG THE SERN EXTENT OF THIS BOUNDARY...NOW MOVING ACROSS SRN GA AND NERN FL. TRAILING PORTION OF THE FRONT....FROM THE ARKLATEX TO THE RIO GRANDE VALLEY...IS EXPECTED TO REMAIN QUASI-STATIONARY THROUGH THE REST OF THIS FORECAST PERIOD BENEATH MODEST SWLY FLOW ALOFT. WEAK PERTURBATIONS EMBEDDED WITHIN THE MID LEVEL FLOW...COUPLED WITH SOME STRENGTHENING OF THE NOCTURNAL LLJ...SHOULD PROMOTE ADDITIONAL STORM DEVELOPMENT ALONG AND NORTH OF THE FRONT...FROM TX TO SRN AR/NRN LA INTO EARLY THURSDAY MORNING. ...NRN MS/AL...SRN GA/FL... INTENSE MCS ACROSS NRN/NERN AL CONTINUES TO DRIFT GENERALLY SWD FUELED BY VERY UNSTABLE AIR MASS TO THE WEST. WHILE SOME WWD PROPAGATION AND ATTEMPTS AT NEW DEVELOPMENT HAVE BEEN NOTED WITHIN THE STRONG INSTABILITY AXIS WWD INTO NERN MS...GENERALLY LIMITED LARGE SCALE FORCING BENEATH MID LEVEL RIDGE MAY BE INHIBITING MORE WIDESPREAD SURFACE-BASED DEVELOPMENT ACROSS THE WARM SECTOR. BULK OF ONGOING ACTIVITY WAS LIKELY BECOMING INCREASINGLY ELEVATED AS STRONG OUTFLOW SPREADS WWD AWAY FROM THE COMPLEX AND DEEP COLD POOL. NONETHELESS...PLUME OF STEEP LAPSE RATES AND FOCUSED FORCING NEAR THE OUTFLOW-REINFORCED WARM FRONT...COMBINED WITH MORE THAN ADEQUATE SHEAR TO MAINTAIN STORM UPDRAFTS...SHOULD RESULT IN AT LEAST A COUPLE MORE HOURS OF SEVERE WEATHER. PRIMARY THREAT FROM ONGOING STORMS WILL BE LARGE HAIL AS ACTIVITY CONTINUES TO TRACK SWD ACROSS ERN AL AND SRN GA. ...TX ENEWD ACROSS SERN OK/NRN LA/SRN AR... WEAK MID LEVEL SHORT WAVE TROUGH AND STRENGTHENING ISENTROPIC LIFT ACROSS THE STATIONARY FRONT OVER TX SHOULD SUPPORT TSTMS INCREASING ALONG AND NORTH OF THE BOUNDARY THROUGH TONIGHT. THIS PROCESS APPEARS TO BE UNDERWAY FROM MAF TO MWL ATTM. ADDITIONAL STORMS...ROOTED CLOSER TO THE SURFACE BOUNDARY...EXIST FROM DIMMIT AND ZAVALA COUNTIES...WHERE A SMALL MCS MAY BE DEVELOPING...NWD ACROSS THE HILL COUNTRY. STRONG INHIBITION ACROSS THE WARM SECTOR AND EAST OF THE ONGOING FRONTAL ACTIVITY MAY INHIBIT ADDITIONAL SURFACE-BASED DEVELOPMENT LATER THIS EVENING. HOWEVER...ONGOING NEAR SURFACE-BASED STORMS WERE CERTAINLY OCCURRING IN AN ENVIRONMENT FAVORABLE FOR INTENSE/SUSTAINED UPDRAFTS AND SOME WIND/ISOLATED TORNADO POTENTIAL WILL EXIST WITH THIS CONVECTION NEAR THE BOUNDARY FOR AT LEAST ANOTHER HOUR OR SO. ELEVATED STORMS NORTH OF THE FRONT WILL POSE A LARGE HAIL THREAT AND EXPECT THIS ACTIVITY TO EXPAND NWD/EWD ACROSS NRN TX AND INTO SRN AR/SRN LA THROUGH DAYBREAK. ..CARBIN.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 06:12:02 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 02:12:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200607 SWODY1 SPC AC 200606 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0106 AM CDT THU APR 20 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX ACROSS THE LOWER MS VALLEY TO SRN KY...TN...WRN GA... ...SYNOPSIS... SPRINGTIME CUTOFF LOW ACROSS THE UPPER MS VALLEY WILL MAKE ONLY SLOW EWD PROGRESS TOWARD THE WRN GREAT LAKES THIS PERIOD AS A LOWER AMPLITUDE AND MORE PROGRESSIVE IMPULSE IN THE SRN BRANCH MOVES EAST FROM AZ/NM TO THE ARKLATEX. DOWNSTREAM FROM THE SRN BRANCH IMPULSE...A MORE SUBTLE AND POTENTIALLY CONVECTIVELY ENHANCED SHORT WAVE DISTURBANCE IS FORECAST TO TRACK EAST FROM THE SRN PLAINS...ACROSS THE LOWER MS VALLEY...AND THEN TO THE CNTRL APPALACHIANS THROUGH LATE TONIGHT. THE TWO SRN STREAM PERTURBATIONS WILL ENHANCE ASCENT ALONG A QUASI-STATIONARY FRONTAL ZONE WHICH WILL REMAIN SITUATED WITHIN A VERY WARM AND MOIST AIRMASS FROM TX TO TN. ...LOWER MS VALLEY/TN VALLEY... ONGOING LARGE MCS FROM NRN TX TO AR WILL MOVE EWD FROM THE ARKLATEX THROUGH THE MORNING SUSTAINED BY WEAK TO MODEST MOISTURE FLUX AND ASCENT OCCURRING ACROSS STALLED DEEP-LAYER FRONTAL ZONE. GUIDANCE APPEARS TO SUGGEST THAT A FRONTAL WAVE COINCIDENT WITH THIS COMPLEX WILL PROPAGATE ENEWD ALONG THE FRONTAL BOUNDARY ACROSS THE LOWER MS VALLEY AND INTO THE TN VALLEY THROUGH THE DAY WITH LARGE SCALE ASCENT ACROSS THESE AREAS ENHANCED BY POSSIBLE MCV. RELATIVELY UNDISTURBED WARM SECTOR AIR MASS SHOULD EXIST EAST OF THE APPROACHING MCS...AND WEST OF RESIDUAL BACK DOOR FRONT/MCS OUTFLOW...FROM MIDDLE TN TO NRN MS. EXPECT MODERATELY UNSTABLE CONDITIONS TO DEVELOP ALONG THE FRONT IN THIS REGION THROUGH THE MORNING GIVEN SUFFICIENT HEATING. FORCING ASSOCIATED WITH THE APPROACHING WAVE SHOULD PROMOTE ADDITIONAL SURFACE-BASED TSTM DEVELOPMENT FROM NRN MS/WRN TN...EWD ACROSS MIDDLE TN AND NRN AL THROUGH THE AFTERNOON. FORECAST SOUNDINGS ACROSS THE REGION APPEAR TO INDICATE WEAK EFFECTIVE SHEAR ACROSS THE WARM SECTOR INITIALLY WHICH MAY RESULT IN GREATER CONCENTRATION OF MULTICELL STORMS WITH SOME HAIL POTENTIAL. HOWEVER...MID LEVEL FLOW AND DEEP SHEAR STRENGTHEN DURING THE AFTERNOON SO STORMS MAY BECOME BETTER ORGANIZED ALONG THE FRONT AND NEAR SURFACE WAVE. THUS... EXPECT ORGANIZED MULTICELLS AND PERHAPS A COUPLE OF SUPERCELLS SPREADING EAST ACROSS THE REGION THROUGH THE AFTERNOON. THIS ACTIVITY WILL BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. TORNADO POTENTIAL MAY ALSO EVOLVE WITH CELLS TRACKING PREFERENTIALLY NEAR THE FRONT...AND ACROSS THE RESIDUAL OUTFLOW BOUNDARY WHERE LOW LEVEL FLOW WILL BE LOCALLY BACKED AND STRONGER SHEAR WILL LIKELY EXIST. ANOTHER FOCUS FOR STORM DEVELOPMENT MAY EXIST FROM SRN GA WWD ACROSS SRN AL AND MS BY LATE AFTERNOON. A SEGMENT OF RESIDUAL FRONT/OUTFLOW MAY MOVE INTO THESE AREAS WHERE DIURNAL HEATING WILL BOOST CAPE BUT REGION MAY REMAIN CAPPED UNTIL LATER IN THE DAY. MODEST MID LEVEL FLOW WILL PROMOTE ORGANIZED STORMS DEVELOPING IN THIS REGIME WITH ATTENDANT THREAT OF HAIL AND WIND. WITH DIURNAL FORCING BEING THE PRIMARY FACTOR IN THE DEVELOPMENT OF THIS ACTIVITY...EXPECT SEVERE POTENTIAL TO GRADUALLY WANE AFTER SUNSET. ...WEST TX TO THE ARKLATEX... FRONTAL ZONE FROM HILL COUNTRY TO ARKLATEX WILL REMAIN WELL DEFINED IN THE WAKE OF OVERNIGHT/MORNING MCS. AIR MASS ALONG AND SOUTH OF THE FRONT IS EXPECTED TO BECOME INCREASINGLY UNSTABLE THROUGH THE DAY WITH 60S DEWPOINTS AND STEEP MID LEVEL LAPSE RATES CONTRIBUTING TO MLCAPE OF 1500-2000 J/KG. HEIGHT FALLS AND LARGE SCALE ASCENT WITH APPROACHING SRN BRANCH SHORT WAVE TROUGH SHOULD INDUCE SURFACE PRESSURE FALLS ACROSS WRN TX WITH WARM SECTOR POSSIBLY EXPANDING NWD AS LOW LEVEL SELY FLOW STRENGTHENS AHEAD OF DEEPENING TRIPLE POINT SURFACE WAVE AND SHARPENING DRYLINE. FORECAST SOUNDINGS ACROSS THE REGION ARE INDICATING 40-45KT EFFECTIVE SHEAR NEAR THE FRONT...AND DEVELOPING EWD ACROSS THE WARM SECTOR INTO THE EVENING. GIVEN EXPECTED FORCING AND INSTABILITY...ENVIRONMENT SHOULD SUPPORT THE DEVELOPMENT OF SUPERCELLS CAPABLE OF PRODUCING LARGE...POSSIBLY SIGNIFICANT... HAIL. ANY DISCRETE STORMS TRACKING NEAR/ALONG THE WSW-ESE ORIENTED FRONTAL BOUNDARY...OR NEAR SURFACE WAVE...COULD ALSO POSE A THREAT FOR TORNADOES WHERE LOW-LEVEL SHEAR AND BOUNDARY LAYER RH WILL BE MAXIMIZED. STORMS MAY UNDERGO UPSCALE ORGANIZATION INTO AN MCS THROUGH THE LATE EVENING AND DAMAGING WIND POTENTIAL MAY INCREASE AS THIS MCS SPREADS EAST TOWARD THE GULF COAST THROUGH EARLY FRIDAY. IT IS POSSIBLE THAT SEVERE WEATHER PROBABILITIES MAY BE INCREASED...AND CATEGORICAL OUTLOOK COULD BE UPGRADED...ACROSS PORTIONS OF TX AS EVOLUTION OF SEVERE WEATHER SCENARIO BECOMES MORE CERTAIN WITH ADDITIONAL SHORT-TERM ANALYSIS AND FORECAST DATA. ..CARBIN/JEWELL.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 12:57:59 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 08:57:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201251 SWODY1 SPC AC 201250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT THU APR 20 2006 VALID 201300Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN AND SRN TX NE THROUGH THE ARKLATEX INTO THE TN VLY... ...SYNOPSIS... DEEP CLOSED LOW OVER THE UPR MS VLY WILL EDGE ONLY SLOWLY E THIS PERIOD AND WILL DOMINATE THE FLOW FIELD ACROSS MUCH OF THE U.S. FARTHER S...SHORTWAVE TROUGH NOW ALONG THE AZ/NM BORDER EXPECTED TO CONTINUE E AT A SOMEWHAT GREATER CLIP...REACHING E TX/SE OK BY 12Z SATURDAY. DOWNSTREAM FROM THE AZ/NM SYSTEM...A WEAKER CONVECTIVELY-ENHANCED DISTURBANCE NOW APPARENT IN SATELLITE AND RADAR DATA OVER THE ARKLATEX REGION SHOULD CONTINUE ENE INTO THE TN VLY LATER TODAY...BEFORE TURNING MORE NE TOWARD THE CNTRL APPALACHIANS TONIGHT. THE TWO SRN SHORTWAVES WILL ENHANCE ASCENT ALONG QUASI-STATIONARY FRONT FROM S TX INTO THE TN VLY AND...ALONG WITH DIURNAL HEATING ...WILL BE THE PRIME FACTORS MODULATING CONVECTIVE DEVELOPMENT THIS PERIOD. ...SW TX TO THE ARKLATEX... VERY MOIST AIR /DEWPOINTS IN THE MID 60S TO LOWER 70S/ IS IN PLACE ALONG AND S OF STALLED FRONTAL ZONE ORIENTED ROUGHLY NEWD FROM S CNTRL TX. CLOUD DEBRIS FROM OVERNIGHT STORMS AND ADDITIONAL STRATUS DEVELOPMENT LIKELY WILL LIMIT SURFACE HEATING IN WARM SECTOR TO SOME EXTENT. BUT FAIRLY SUBSTANTIAL SURFACE-BASED DESTABILIZATION /MLCAPE TO 2000 J PER KG/ SHOULD NEVERTHELESS OCCUR FROM THE BIG BEND REGION ENE ALONG FRONT INTO CNTRL TX. INCREASING LARGE SCALE ASCENT ASSOCIATED WITH APPROACHING AZ/NM TROUGH...ALREADY RESPONSIBLE FOR RECENT DEVELOPMENT OF ELEVATED STORMS IN W CNTRL TX...SHOULD FURTHER ENHANCE DESTABILIZATION AND SUPPORT SCATTERED AREAS OF STORM DEVELOPMENT BY MID AFTERNOON. 40 KT WSWLY MID LEVEL FLOW DOWNSTREAM FROM TROUGH WILL CONTRIBUTE SUFFICIENT SHEAR FOR SUPERCELLS WITH VERY LARGE HAIL. POTENTIAL WILL ALSO EXIST FOR A FEW STORMS TO MOVE ALONG FRONT AND/OR OUTFLOW BOUNDARY SEGMENTS THAT SHOULD BE FAVORABLY ORIENTED TO ENHANCE LOW LEVEL SRH/TORNADO DEVELOPMENT. COMBINATION OF INCREASING INSTABILITY CONCURRENT WITH DIURNAL HEATING...AND PRESENCE OF FRONT/OUTFLOW BOUNDARIES...SUGGEST THAT SOME OF THE STORMS WILL FAIRLY QUICKLY ORGANIZE INTO BANDS AND/OR CLUSTERS. THESE SYSTEMS SHOULD MOVE/DEVELOP GENERALLY E TOWARD THE TX CSTL PLN LATER TODAY/TONIGHT...WHERE THERE WILL EXIST A THREAT FOR BOWING SEGMENTS WITH HIGH WIND/HAIL AND PERHAPS A COUPLE TORNADOES. FARTHER N...EXPECT INCREASING COVERAGE OF SLIGHTLY ELEVATED STORMS WITH HAIL AND POSSIBLY DAMAGING WIND FROM W CNTRL TX ENE THROUGH THE ARKLATEX LATER TODAY/TONIGHT AS WARM/MOISTURE ADVECTION STRENGTHEN AHEAD OF PROGRESSIVE AZ/NM TROUGH. ...LWR MS/TN VLY TO SRN/CNTRL APLCNS... POCKET OF STRONG SURFACE-BASED INSTABILITY /SBCAPE TO 2500 J PER KG/ LIKELY WILL DEVELOP OVER NRN MS/SRN MIDDLE TN AND NRN/CNTRL AL WITH HEATING TODAY. THIS REGION WILL BE GLANCED BY ENHANCED WSWLY FLOW ASSOCIATED WITH ARKLATEX MCV. WHILE LOW LEVEL WIND FIELD LIKELY WILL REMAIN WEAK...COMBINATION OF STEEP LOW TO MID LEVEL LAPSE RATES AND 40-50 KT WSWLY MID LEVEL FLOW /PER SHV 12Z RAOB/ MAY PROVE FAVORABLE FOR CLUSTERS OF STORMS/POSSIBLE SUPERCELLS WITH VERY LARGE HAIL AND POSSIBLY HIGH WIND. THIS ACTIVITY SHOULD DEVELOP ACROSS NRN MS/SRN MIDDLE TN BY MID TO LATE MORNING...AND MAY TEND TO SPREAD MORE W TO E THAN WAS THE CASE YESTERDAY AS UPPER FLOW HAS BACKED CONSIDERABLY RELATIVE TO WEDNESDAY. FARTHER N...MORE WIDELY SCATTERED PULSE STORMS WITH MARGINALLY SEVERE HAIL MAY OCCUR EPISODICALLY NWD INTO PARTS OF KY AND...ESPECIALLY LATER IN THE PERIOD...NEWD INTO THE CNTRL APPALACHIANS. ..CORFIDI/JEWELL.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 16:16:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 12:16:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201612 SWODY1 SPC AC 201611 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CDT THU APR 20 2006 VALID 201630Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX TO THE SRN APPALACHIANS... ...TN RIVER VALLEY/CENTRAL GULF COAST STATES INTO THE SRN APPALACHIANS... CONVECTION WILL CONTINUE TO BUILD UPSCALE INTO AN MCS INTO MUCH OF MIDDLE TN/CENTRAL KY AND SPREAD ENEWD INTO THE APPALACHIANS THIS AFTERNOON. THIS ACTIVITY WILL INCREASE AHEAD OF SHORTWAVE TROUGH NOW MOVING OVER THE MID SOUTH. INCREASING CONVECTION/CLOUDS WILL HINDER HEATING AND OVERALL DESTABILIZATION OVER MUCH OF THE TN RIVER VALLEY AND POINTS EWD. IN ADDITION...THIS WILL LIMIT NEWD RETURN OF RICHER MOISTURE NOW CONFINED TO REGIONS EAST OF N-E ORIENTED OUTFLOW BOUNDARY FROM YESTERDAYS STORMS. LARGE HAIL WILL BECOME SCATTERED NORTHEAST OF THIS BOUNDARY...THOUGH MUCH OF IT WILL REMAIN MARGINAL IN SEVERITY. IF AREA DESTABILIZES MORE THAN EXPECTED...LARGE HAIL THREAT WOULD INCREASE IN COVERAGE AND SEVERITY. STORMS ROOTING INTO NRN EXTENT OF MODERATE MLCAPE AXIS INTO NRN MS/NRN AL WILL BE MORE LIKELY TO BECOME MORE ORGANIZED AS WLY FLOW ALOFT MAINTAINS 40 KT OF EFFECTIVE SHEAR. DURING THE MID TO LATE AFTERNOON...HEATING AND MIXING OF SWLY FLOW ALOFT WILL ERODE NRN EDGE OF PERSISTENT SURFACE BOUNDARY AND DESTABILIZE AHEAD OF OUTFLOW BOUNDARY NOW SHIFTING SSEWD INTO NRN MS. TAIL END OF SHORTWAVE TROUGH AND CONVERGENCE WILL LIKELY INITIATE MORE VIGOROUS SEVERE THUNDERSTORMS FROM NRN MS ACROSS NRN/CENTRAL AL...POSSIBLY BY 18Z. FORECAST SOUNDINGS AGAIN FAVOR VERY LARGE HAIL AND PERHAPS A FEW PERSISTENT SUPERCELLS/ORGANIZED CLUSTERS. THIS ACTIVITY SHOULD SPREAD GENERALLY EWD INTO THE SRN APPALACHIANS THROUGH THE EVENING...WITH THREATS OF DAMAGING WINDS AND LARGE HAIL. ...TX INTO THE LOWER MS RIVER VALLEY... COMPLEX EVOLUTION ANTICIPATED ACROSS TX TODAY. STRONG UPPER LOW IS NOW MOVING INTO THE SRN HIGH PLAINS...WITH SUBSEQUENT MID/UPPER LEVEL JET OVERSPREADING TX. SURFACE PATTERN IS QUITE MESSY DUE TO EARLIER CONVECTION...THOUGH EXPECT PRIMARY SURFACE WARM FRONT WILL BECOME BETTER DEFINED FROM THE UPPER TX COAST INTO THE HILL COUNTRY DURING THE AFTERNOON. SOUTH OF THIS BOUNDARY RICH GULF MOISTURE REMAINS IN PLACE WITH SURFACE DEW POINTS AROUND 70F. SLY LLJ OBSERVED ON MORNING UPPER AIR ANALYSES WILL REMAIN ANCHORED INTO THE BIG BEND REGION/EDWARDS PLATEAU THROUGH THE DAY AND MAINTAIN ELEVATED STRONG TO SEVERE THUNDERSTORMS INTO WRN AND NWRN TX. ACTIVITY NOW ONGOING IN THE HILL COUNTRY NEAR THE FRONT MAY BECOME INCREASINGLY SURFACE BASED AND PERSIST EWD INTO CENTRAL TX THROUGH THE AFTERNOON. OTHER VIGOROUS DEVELOPMENT IS EXPECTED TO OCCUR NEARER THE DRY LINE AND AHEAD OF STRONG UPPER LOW INTO SWRN/CENTRAL TX LATER TODAY. THIS ACTIVITY WILL BECOME INCREASINGLY WIDESPREAD WITH INITIAL DEVELOPMENT AS SUPERCELLS AND ORGANIZED CLUSTERS. VERY LARGE HAIL AND A FEW TORNADOES SHOULD ACCOMPANY THESE STORMS. SUPERCELLS MAY PERSIST NEAR THE FRONT...THOUGH OVERALL ACTIVITY SHOULD MORPH INTO ONE OR TWO LARGE MCSS AND SPREAD INCREASED SEVERE THREAT EWD TOWARDS THE MIDDLE TX COAST AND ERN TX THROUGH THE EVENING/OVERNIGHT. ..EVANS/CROSBIE.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 19:52:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 15:52:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201948 SWODY1 SPC AC 201946 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0246 PM CDT THU APR 20 2006 VALID 202000Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN TX INTO ERN TN... ...TX... A LARGE CLUSTER OF THUNDERSTORMS HAS EVOLVED FROM THE HILL COUNTRY OF CNTRL TX INTO THE TX SOUTH PLAINS NEAR LBB. THIS ACTIVITY IS DRIVEN IN LARGE PART DUE TO LOW LEVEL WARM ADVECTION ATOP ENTRENCHED COOLER LOW LEVEL BOUNDARY LAYER WHERE ENELY SFC WINDS PERSIST. LLJ WILL REMAIN FOCUSED INTO SWRN TX FOR THE NEXT FEW HOURS BEFORE GRADUALLY VEERING INTO CNTRL TX LATER THIS EVENING. IN THE SHORT TERM...CONTINUED HEATING WILL BE REQUIRED OVER NRN MEXICO...EWD ALONG THE WARM FRONT BEFORE MORE ROBUST WARM SECTOR CONVECTION WILL EVOLVE. UPDRAFT CLUSTERS ARE GRADUALLY LOWERING JUST NORTH OF THE WIND SHIFT OVER GILLESPIE COUNTY TX...WITH A NOTABLE EWD PROPAGATION ALIGNED ALONG FRONTAL ORIENTATION. SHEAR PROFILES REMAIN FAVORABLE FOR SUPERCELL DEVELOPMENT AND WITH TIME POTENTIALLY TORNADIC...ALTHOUGH LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT. LATER TONIGHT...CLUSTER MERGERS AND GRADUALLY VEERING WINDS WITH HEIGHT SHOULD ENHANCE FORWARD PROPAGATION COMPONENT AND DAMAGING WINDS MAY BECOME MORE OF AN ISSUE AS MCS EVOLVES AND SPREADS TOWARD THE MIDDLE/UPPER TX COAST. ...SERN AR TO NRN AL... ISOLATED SEVERE THUNDERSTORMS ARE EVOLVING OVER SERN AR...WITH MOVEMENT EXPECTED INTO NWRN MS SHORTLY. THIS ACTIVITY IS DEVELOPING WITHIN A FAIRLY UNSTABLE AIRMASS...SBCAPES ON THE ORDER OF 2000-3000J/KG...WHERE BOUNDARY LAYER INSTABILITY/LAPSE RATES HAVE INCREASED MARKEDLY OVER THE LAST FEW HOURS. SCATTERED SUPERCELLS SHOULD CONTINUE TO DEVELOP AND SPREAD NEWD ACROSS NRN MS INTO NRN AL ALONG OUTFLOW REMNANTS FROM EARLIER CONVECTIVE ACTIVITY. ADDITIONAL STORMS ARE DEVELOPING WELL EAST INTO NRN AL AT THIS TIME...ALONG MOST PROGRESSIVE PORTION OF WIND SHIFT. THIS BOUNDARY SHOULD ENHANCE THE SUPERCELL THREAT WHILE STEEP LAPSE RATE ENVIRONMENT/CAPE WILL CONTRIBUTE TO THE POTENTIAL FOR VERY LARGE HAIL. UPSTREAM CONVECTION THAT DEVELOPS ACROSS THE ARKLATEX REGION THIS EVENING MAY SPREAD EAST OF THE MS RIVER INTO NRN MS/WRN TN TOWARD THE END OF THE PERIOD...HOWEVER MORE SIGNIFICANT CONVECTION SHOULD OCCUR WITH THE MORE DIURNALLY DRIVEN STORMS THIS AFTERNOON INTO EARLY EVENING. ..DARROW.. 04/20/2006  From SwoDy1 at goshenarc.org Fri Apr 21 01:13:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 21:13:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210109 SWODY1 SPC AC 210107 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0807 PM CDT THU APR 20 2006 VALID 210100Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WEST TX ACROSS THE ARKLATEX TO THE TN VALLEY AND NRN GA... ...SYNOPSIS... QUASI-STATIONARY FRONT WAS SITUATED FROM WEST TX TO THE TN VALLEY THIS EVENING WITH SEVERAL AREAS OF ONGOING VIGOROUS CONVECTION BEING FUELED BY MOIST AND UNSTABLE AIR MASS FLOWING NWD INTO THE FRONTAL ZONE. THE FRONT WAS ALIGNED WITH MODEST /40-50KT/ SWLY MID LEVEL FLOW WITH ONGOING STORMS...AND CONTINUING POTENTIAL FOR DEEP CONVECTION...TIED TO THE PASSAGE OF MID/UPPER LEVEL IMPULSES EMBEDDED WITHIN THE SWLY FLOW ALOFT. ONE OF THESE IMPULSES WAS CURRENTLY MOVING EAST FROM SERN NM AND WILL ENHANCE DEEP LAYER ASCENT ACROSS THE FRONT...FROM WEST TX TO THE LOWER MS VALLEY... THROUGH FRIDAY MORNING. A MORE ELONGATED AND LOWER AMPLITUDE IMPULSE...AND ITS ASSOCIATED MID LEVEL WIND MAX...WERE LIFTING NEWD FROM WRN TN TO THE LOWER OH RIVER VALLEY. ...TX TO NWRN MS... COMPLEX MESOSCALE SITUATION EXISTS ACROSS MUCH OF WRN AND CNTRL TX THIS EVENING WITH A NUMBER OF INTENSE SUPERCELLS AND SLOW MOVING LINE SEGMENTS MOVING EAST FROM THE HILL COUNTRY/AUSTIN AREA TO NW OF HOU. BULK OF THIS ACTIVITY ACROSS THE HILL COUNTRY WAS NEAR/ALONG RESIDUAL SYNOPTIC FRONT BUT NORTH OF AN OLD OUTFLOW BOUNDARY THAT WAS AIDING NEW STORM DEVELOPMENT WEST OF SAN ANTONIO. STRONG DEEP-LAYER ASCENT WITH APPROACHING SHORT WAVE TROUGH...AND INCREASING MASS INFLOW...SHOULD PROMOTE CONTINUING UPSCALE DEVELOPMENT. EVOLVING LARGE MCS WILL DEVELOP EAST INTO LA/SRN AR...AND NRN MS...OVER THE NEXT SEVERAL HOURS. INSTABILITY RESIDING ALONG THE FRONT SHOULD CONTINUE TO PROMOTE STOUT UPDRAFTS WHILE MODEST FORCING...STRONG SHEAR...AND STEEP LAPSE RATES CONTRIBUTE TO SEVERE HAIL AND WIND POTENTIAL. BRIEF TORNADO CANNOT BE RULED OUT FOR CELLS NEAR OR CROSSING THE FRONT...ESPECIALLY OVER THE NEXT HOUR OR SO FOR THE CLUSTER OF STORMS MOVING EAST FROM AUSTIN AREA. ELEVATED STORMS NEAR THE VORT CENTER MOVING TOWARD NWRN TX MAY POSE SOME THREAT OF HAIL OR ISOLATED STRONG WIND GUSTS ACROSS NRN TX OVER THE NEXT FEW HOURS. ...AL/GA... LARGE MCS ACROSS NRN GA WAS BECOMING GRADUALLY LESS ORGANIZED GIVEN WIDESPREAD ATMOSPHERIC OVERTURNING AND GRADUALLY DIMINISHING INSTABILITY AND FORCING. HOWEVER...A FEW SEVERE STORMS/SUPERCELLS WITH HAIL AND/OR WIND WILL REMAIN POSSIBLE ON THE FRINGES OF THE LARGE COLD POOL WHERE UNTAPPED INSTABILITY AND WEAK ISENTROPIC LIFT WILL PERSIST FOR A FEW MORE HOURS...GENERALLY FROM WCNTRL GA ACROSS CNTRL AL...AND PERHAPS INTO NERN MS. ..CARBIN.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 04:40:48 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 00:40:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210436 SWODY1 SPC AC 210435 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CDT THU APR 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS VALLEY NWD ACROSS THE TN VALLEY TO THE CNTRL APPALACHIANS... ...SYNOPSIS... HIGH AMPLITUDE FLOW WILL BECOME MORE PROGRESSIVE ACROSS THE WEST AND SOUTH THIS PERIOD WHILE NRN STATES CUT-OFF LOW MAKES ONLY SLOW EWD PROGRESS OVER THE WRN GREAT LAKES REGION. PRIMARY FEATURE EXPECTED TO DRIVE SEVERE THUNDERSTORM POTENTIAL THROUGH TODAY WILL BE THE SRN BRANCH SHORT WAVE TROUGH CURRENTLY MOVING ACROSS TX. THIS MID-LEVEL WAVE IS FORECAST TO TRANSLATE EWD ACROSS THE MS VALLEY THROUGH LATE TODAY WITH STRONGEST 12H HEIGHT FALLS OF 30-60M MOVING OVER THE SOUTHEAST U.S. BY THE END OF THE PERIOD...SATURDAY MORNING. A NUMBER OF WEAK FRONTAL WAVES MAY EXIST ALONG DEEP-LAYER BAROCLINIC ZONE SITUATED FROM THE UPPER TX COAST TO THE TN VALLEY TODAY. BASED ON LATEST TRENDS...AN MCS OR TWO MAY SURVIVE INTO THE MORNING HOURS NEAR THE FRONT. PRIMARY SURFACE LOW/WAVE ASSOCIATED WITH THE SRN BRANCH SHORT WAVE TROUGH SHOULD BE COINCIDENT WITH A LARGE MCS MOVING ACROSS LA/AR/MS AREA DURING THE MORNING. LATEST NAM-ETA AND SREF MEAN FORECASTS INDICATE THAT THIS PRIMARY LOW WILL TRACK NEWD ACROSS THE MS RIVER TO NRN MS DURING THE AFTERNOON...AND THEN INTO NRN AL DURING THE EVENING. TRAILING COLD FRONT WILL MOVE EAST INTO A MOIST AND UNSTABLE AIR MASS FROM THE LOWER MS VALLEY...TO THE WRN FL PNHDL THROUGH EARLY SATURDAY. ...LA/MS ACROSS TN VALLEY... DIURNAL DESTABILIZATION AHEAD OF MCS OUTFLOW/SFC FRONT AND FRONTAL WAVE WILL PROMOTE THUNDERSTORM INTENSIFICATION DURING THE AFTERNOON ACROSS MS. FURTHERMORE...MID LEVEL WIND MAX ROUNDING THE BASE OF MID/UPPER TROUGH WILL ENHANCE DEEP LAYER SHEAR AND STORM ORGANIZATION ACROSS THE WARM SECTOR. WHILE DEEP LAYER S/SWLY FLOW MAY LIMIT HODOGRAPH CURVATURE...POTENTIAL FOR LOCALLY STRONGER LOW LEVEL SHEAR MAY EVOLVE NEAR THE SURFACE LOW WHERE A FEW LONGER-LIVED SUPERCELLS WILL BE POSSIBLE. CONVECTION WILL CONTINUE TO INCREASE IN AREAL COVERAGE AND INTENSITY INTO THE EVENING WITH STORMS IN BANDS OR CLUSTERS PRODUCING HAIL/WIND DAMAGE...AND PERHAPS A COUPLE TORNADOES...FROM NRN/ERN MS TO AL AND MIDDLE TN. ADDITIONAL STORMS...PERHAPS IN THE FORM OF SUPERCELLS OR LINE SEGMENTS WITH ISOLATED DAMAGING WINDS...SHOULD PRECEDE THE COLD FRONT DEVELOPING EAST FROM THE MS DELTA TO THE FL PNHDL THROUGH THE NIGHT. ...FL... SEA BREEZE CONVECTION IN MODERATELY UNSTABLE AIR MASS HAS THE POTENTIAL TO BE A BIT MORE ROBUST TODAY AS WEAK HEIGHT FALLS MOVE TOWARD THE REGION FROM THE WEST. WHILE LARGE SCALE DEEP LAYER SHEAR WILL BE WEAK...ONE OR TWO CELL INTERACTIONS WITHIN SEA BREEZE COLLISION ZONE OVER THE ERN PENINSULA COULD PRODUCE AN ISOLATED HAIL OR WIND EVENT. ..CARBIN/JEWELL.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 13:01:09 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 09:01:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211257 SWODY1 SPC AC 211255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 AM CDT FRI APR 21 2006 VALID 211300Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT ACROSS THE LOWER MS AND TN VALLEYS.... ...LOWER MS AND TN VALLEYS... A SRN STREAM SHORTWAVE TROUGH OVER N TX WILL CONTINUE EWD TODAY ACROSS THE GULF COAST STATES...AROUND THE SRN PERIPHERY OF A CLOSED LOW OVER THE UPPER MS VALLEY. IN ADVANCE OF THE SRN STREAM TROUGH...SMALLER SCALE CONVECTIVELY INDUCED VORTICITY MAXIMA ARE ASSOCIATED WITH CONVECTIVE CLUSTERS OVER NRN MS AND THE UPPER TX COAST. THE STABILIZING EFFECTS OF THESE STORM CLUSTERS WILL TEND TO LIMIT THE SEVERE THREAT TODAY TO THE NW OF THE COMPOSITE OUTFLOW BOUNDARY FROM SE TX ACROSS NRN LA TO NRN MS...WITH THE STRONGER STORMS FOCUSED IN ADVANCE OF THE MCV/S AND ALONG THE REMNANT OUTFLOW BOUNDARIES DURING THE DAY. SURFACE OBSERVATIONS AND MORNING SOUNDINGS SHOW BOUNDARY LAYER DEWPOINTS OF 65-70 F ACROSS LA/MS/AL TO THE S AND E OF THE OUTFLOW BOUNDARIES. DAYTIME HEATING WILL COMBINE WITH THIS LOW-LEVEL MOISTURE AND MID LEVEL LAPSE RATES NEAR 7 C/KM TO SUPPORT MLCAPE VALUES OF 1500-2000 J/KG WITHIN THE WARM SECTOR. VERTICAL SHEAR IN THE WARM SECTOR WILL BE MODULATED INITIALLY BY THE WAVE MOVING NEWD FROM MS TO TN...AS CONFIRMED BY VWP TIME SERIES ACROSS MS. EXPECT THE STRONGER L0W-LEVEL SHEAR AND WAA TO SHIFT NEWD FROM NRN AL TOWARD TN AND N GA THROUGH THE MORNING IN ADVANCE OF THE NRN MS WAVE...THOUGH WEAKENING INSTABILITY WITH NWD EXTENT AND THE EFFECTS OF ONGOING CONVECTION WILL TEND TO LIMIT THE SEVERE THREAT TO THE N OF TN. FARTHER SW...THE BACKING FLOW WITH HEIGHT OVER MS WILL TEND TO RECOVER TO A SOMEWHAT MORE FAVORABLE PROFILE DURING THE DAY...AS THE NRN MS WAVE MOVES AWAY TO THE NE AND THE PRIMARY TROUGH APPROACHES FROM THE W. MODEST VERTICAL SHEAR BENEATH 55 KT SWLY MID LEVEL FLOW WILL SUPPORT BOWING LINE SEGMENTS AND PERHAPS SUPERCELLS AS CONVECTION DEVELOPS ALONG THE SURFACE BOUNDARY FROM CENTRAL LA INTO WRN MS. CONVECTION MAY ALSO EVOLVE FROM THE ONGOING STORMS MOVING ACROSS SE TX. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREATS. ..THOMPSON/JEWELL.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 16:37:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 12:37:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211634 SWODY1 SPC AC 211632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT FRI APR 21 2006 VALID 211630Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS AND TN VALLEYS INTO THE GULF COAST REGION... ...LOWER MS AND TN VALLEY... BROAD UPPER LOW REMAINS OVER THE UPPER MIDWEST TODAY...WITH SERIES OF SHORTWAVE TROUGHS ROTATING EASTWARD FROM TX INTO THE GULF COAST REGION. ONE SUCH FEATURE IS NOW OVER NORTH CENTRAL TX...AND IS ASSOCIATED WITH LARGE MCS ACROSS LA. THESE STORMS HAVE SHOWN SIGNS OF WEAKENING THIS MORNING. HOWEVER...MOIST/UNSTABLE AIR MASS TO THE EAST WILL ALLOW RE-INTENSIFICATION ACROSS PARTS OF LA/MS/AL THIS AFTERNOON AND EVENING. DAYTIME HEATING...DEWPOINTS IN THE MID/UPPER 60S...AND RELATIVELY COOL MID LEVEL TEMPERATURES WILL PROMOTE A RISK OF DAMAGING WINDS AND LARGE HAIL. ACTIVITY MAY SPREAD INTO PARTS OF SOUTHEAST TN AND NORTHERN/WESTERN GA OVERNIGHT BEFORE WEAKENING. ...CA... NEXT LARGE TROUGH IS ROTATING INTO CA TODAY. WATER VAPOR IMAGERY SHOWS MAIN VORT MAX OFFSHORE...WHICH SHOULD MOVE INTO CENTRAL CA THIS AFTERNOON AND EARLY EVENING. MODEL FORECAST SOUNDINGS SUGGEST THAT MODERATE INSTABILITY WILL DEVELOP OVER THE NORTHERN/CENTRAL VALLEY WITH DEWPOINTS IN THE 50S AND MLCAPE VALUES OVER 1000 J/KG. PRESENT INDICATIONS ARE THAT ISOLATED STRONG STORMS CAPABLE OF HAIL WILL BE POSSIBLE. ACTIVITY SHOULD DIMINISH WITHIN A COUPLE HOURS AFTER SUNSET. ...FL... STRONG DAYTIME HEATING IS OCCURRING TODAY OVER THE FL PENINSULA...WHERE A VERY UNSTABLE AIR MASS IS EXPECTED TO DEVELOP BY AFTERNOON. SEA BREEZE CONVERGENCE WILL LIKELY RESULT IN SCATTERED THUNDERSTORMS ALONG THE EAST COAST...WITH THE POTENTIAL OF HAIL/GUSTY WINDS AND BRIEF TORNADOES IN STRONGER CELLS. ..HART/GUYER.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 20:09:28 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 16:09:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212005 SWODY1 SPC AC 212003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT FRI APR 21 2006 VALID 212000Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL GULF COAST/TN VALLEY REGION... ...CENTRAL GULF COAST REGION INTO THE TN VALLEY... MODERATE INSTABILITY IS INDICATED ACROSS THE CENTRAL GULF COAST REGION AND INTO TN THIS AFTERNOON...AHEAD OF VIGOROUS MID-LEVEL VORT MAX NOW MOVING NEWD ACROSS SERN LA/MS. WITH RELATIVELY STRONG SWLY MID-LEVEL JET STREAK ON SERN PERIPHERY OF THIS FEATURE...SUFFICIENT SHEAR EXISTS TO SUPPORT A CONTINUED THREAT ORGANIZED/SUPERCELL STORMS. STRONGEST STORMS ATTM EXIST FROM SRN MS NEWD INTO SERN TN...AND THIS CORRIDOR SHOULD REMAIN THE MOST FAVORABLE ZONE FOR LOCALLY-DAMAGING WINDS AND HAIL THROUGH THIS AFTERNOON. THOUGH SEVERE THREAT MAY EXTEND EWD ACROSS GA LATER THIS EVENING...OVERALL THREAT SHOULD DIMINISH SLOWLY AFTER SUNSET. ...FL... MODERATE INSTABILITY BUT WEAK SHEAR IS INDICATED ACROSS THE FL PENINSULA...WHICH WILL CONTINUE TO SUPPORT THE DEVELOPMENT OF ISOLATED VIGOROUS/PULSE-TYPE SEVERE STORMS THIS AFTERNOON. ACCOMPANYING THREAT FOR HAIL/LOCALLY DAMAGING WINDS SHOULD DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING. ...CENTRAL CA... COOLING ALOFT ASSOCIATED WITH APPROACHING UPPER TROUGH WILL CONTINUE TO STEEPEN LAPSE RATES ACROSS CENTRAL CA THROUGH THE PERIOD. THIS COMBINED WITH DAYTIME HEATING AND DEWPOINTS IN THE 50S IN THE CENTRAL VALLEY MAY YIELD INSTABILITY SUFFICIENT FOR A FEW STRONGER STORMS -- POSSIBLY CAPABLE OF PRODUCING ISOLATED/MARGINALLY-SEVERE HAIL. ..GOSS.. 04/21/2006  From SwoDy1 at goshenarc.org Sat Apr 22 01:10:42 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 21:10:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220107 SWODY1 SPC AC 220105 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0805 PM CDT FRI APR 21 2006 VALID 220100Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NERN GULF COAST TO THE SRN APPALACHIANS... ...FL PANHANDLE TO SRN APPALACHIANS... SEVERAL MORE HOURS OF SCATTERED SEVERE THUNDERSTORM EVENTS APPEAR POSSIBLE TONIGHT AS AN ACCELERATING MID LEVEL WAVE...AND ASSOCIATED FRONTAL ZONE...DEVELOP ENEWD INTO MOIST AND MARGINALLY UNSTABLE AIR MASS FROM THE NERN GULF COAST TO THE SRN APPALACHIANS. LARGE MCS PRECEEDING THE UPPER WAVE WAS CURRENTLY MOVING ACROSS NRN AL AND ERN TN WITH SEVERAL INTENSE TSTMS ALONG THE LEADING EDGE OF MORE WIDESPREAD STRATIFORM RAIN REGION. LATEST ATLANTA AREA SOUNDING WAS INDICATING MARGINAL...BUT ADEQUATE...INSTABILITY TO MAINTAIN DEEP CONVECTION WITHIN A STRONGLY SHEARED KINEMATIC ENVIRONMENT FROM ERN AL ACROSS GA AND INTO PARTS OF THE WRN CAROLINAS. EXPECT MARGINALLY SEVERE HAIL AND PERHAPS ISOLATED WIND DAMAGE TO ACCOMPANY SOME OF THE STRONGER STORMS ACROSS THESE AREAS TONIGHT. CLOSER TO THE GULF COAST...TRAILING PORTION PRE-FRONTAL SQUALL LINE OVER SRN AL AND THE WRN FL PNHDL APPEARS TO HAVE OUTRUN STRONGER LARGE SCALE FORCING WITH THE UPPER IMPULSE TO THE WEST. HOWEVER...A COUPLE OF STOUT STORMS PERSIST ALONG THIS FEATURE NEAR MOBILE BAY ATTM. MODEL GUIDANCE CONTINUES TO INDICATE THAT ADDITIONAL STORM FORMATION REMAINS POSSIBLE AS THE SURFACE FRONT AND STRENGTHENING MID LEVEL FLOW MOVE EAST INTO INSTABILITY AXIS LATER TONIGHT. THERMODYNAMIC ENVIRONMENT INDICATED IN BOTH SIL AND TLH RAOBS WOULD APPEAR TO SUPPORT RENEWED CONVECTIVE DEVELOPMENT GIVEN SUFFICIENT FORCING NEAR THE FRONT LATER TONIGHT. THUS...SEVERE WEATHER POTENTIAL MAY INCREASE ACROSS SRN PARTS OF THE SLGT RISK AREA BEFORE THE END OF THIS FORECAST PERIOD. ...NERN FL TO ERN SC... ISOLATED STRONG TO SEVERE STORMS PERSIST FROM ERN FL/SERN GA SEABREEZE NWD TO PRE-FRONTAL CONFLUENCE AXIS OVER NWRN SC. GIVEN APPROACH OF STRONGER LARGE SCALE FORCING FOR ASCENT AND ADEQUATE MOISTURE FLUX INTO THE REGION OF ONGOING ACTIVITY...ISOLATED TO WIDELY SCATTERED DAMAGING WINDS AND/OR HAIL APPEAR POSSIBLE BEFORE ADDITIONAL AND MORE WIDESPREAD CONVECTION DEVELOPS ACROSS SOME OF THE REGION THROUGH LATE TONIGHT. ...CNTRL CA... WEAK DIURNAL DESTABILIZATION...COUPLED WITH MODEST TO STRONG ASCENT ASSOCIATED WITH MID/UPPER LEVEL SHORT WAVE TROUGH...HAS AIDED STORM INITIATION ALONG THE I5 CORRIDOR LATE THIS AFTERNOON. ADDITIONAL STORMS HAVE DEVELOPED IN THE NRN SIERRA. STRONGEST CELLS COULD PRODUCE HAIL OR PERHAPS A LOCALIZED NEAR-SEVERE WIND GUST OVER THE NEXT FEW HOURS BEFORE INABILITY WEAKENS AFTER SUNSET. ..CARBIN.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 06:14:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 02:14:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220609 SWODY1 SPC AC 220607 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SAT APR 22 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN VA AND THE CAROLINAS TO FL... ...SYNOPSIS... HIGHLY AMPLIFIED MULTI-STREAM UPPER FLOW WILL PERSIST ACROSS NORTH AMERICA THROUGH THE WEEKEND WITH A HIGH PLAINS UPPER RIDGE AXIS SEPARATING CLOSED LOWS OVER THE SOUTHWEST AND GREAT LAKES. A SRN BRANCH SHORT WAVE TROUGH UNDERCUTTING THE GREAT LAKES LOW WILL CONTINUE TO DRIVE A DEEP LAYER FRONTAL ZONE EWD ACROSS THE ATLANTIC COAST STATES FROM FL TO NJ. IN THE WAKE OF THIS SYSTEM... LOW LEVEL SLY FLOW WILL GRADUALLY STRENGTHEN FROM THE RIO GRANDE VALLEY ACROSS THE PLAINS AS LEE-SIDE TROUGHING BECOMES RE-ESTABLISHED OVER THE REGION. LOW LEVEL MOISTURE FLUX WILL ALSO INCREASE THROUGH TONIGHT FROM THE SRN HIGH PLAINS NWD/NEWD TO THE MO VALLEY AS BUILDING UPPER RIDGE TRANSPORTS ELEVATED MIXED LAYER AIR MASS EWD OFF THE ROCKIES ESCARPMENT. LASTLY...GREAT LAKES CUT-OFF LOW WILL BEGIN TO BE DISPLACED ESEWD THIS PERIOD AS A STRONG UPSTREAM TROUGH...CURRENTLY OVER BC...MOVES EAST. ...EAST COAST FROM SERN VA TO FL... LARGE SCALE ASCENT WILL SPREAD EAST ATOP MOIST BUT ONLY MARGINALLY UNSTABLE AIR MASS FROM THE APPALACHIANS EWD ACROSS MUCH OF NC AND VA THROUGH THE DAY. STRONGER INSTABILITY OVER MUCH OF THIS REGION MAY BE INHIBITED BY WIDESPREAD CONVECTIVE DEBRIS FROM ONGOING MCS CURRENTLY CROSSING THE SRN APPALACHIANS. HOWEVER...A NARROW WINDOW OF OPPORTUNITY FOR GREATER DESTABILIZATION IS SUGGESTED IN LATEST GUIDANCE FROM ERN SC ACROSS ERN NC WHERE MLCAPE IN THE RANGE OF 500-1500 J/KG MAY DEVELOP AHEAD OF MORE FOCUSED FORCING AND STRENGTHENING DEEP-LAYER FLOW NEAR POSSIBLE FRONTAL WAVE. THIS SHOULD ALLOW STORMS TO INCREASE IN INTENSITY/ORGANIZATION AS THE FRONT MOVES EAST FROM AFTERNOON THROUGH EVENING. A FEW MARGINAL HAIL/WIND EVENTS APPEAR POSSIBLE WITH THIS ACTIVITY...ALONG WITH A LOW PROBABILITY TORNADO THREAT. FARTHER SOUTH...STRONG IMPULSE ROTATING THROUGH THE BASE OF THE LARGE SCALE TROUGH WAS RESULTING IN STORMS INTENSIFYING ACROSS THE FL PANHANDLE EARLY TODAY. THIS ACTIVITY MAY CONTINUE EAST INTO SRN GA AND NRN FL THIS MORNING WITH THE CHANCE FOR WIND DAMAGE AND HAIL CONTINUING. LARGE SCALE HEIGHT FALLS WITH THE UPPER TROUGH WILL COMBINE WITH INCREASING DIURNAL INSTABILITY ACROSS FL TO PROMOTE ADDITIONAL STORM DEVELOPMENT THROUGH THE DAY. DEEP LAYER SHEAR OVER THE REGION WILL STRENGTHEN AND...COUPLED WITH POTENTIAL FOR SEABREEZE INTERACTIONS...RESULT IN ORGANIZED STORM UPDRAFTS WITH A CHANCE FOR HAIL/WIND AND PERHAPS A TORNADO. ...WEST TX/ERN NM... UPSLOPE FLOW AND RETURN OF 50S F DEWPOINTS TO THE SRN HIGH PLAINS WILL COMBINE WITH STRONG HEATING/MIXING TO SUPPORT ISOLATED HIGH-BASED CONVECTIVE DEVELOPMENT OVER THE HIGHER TERRAIN BY LATE AFTERNOON. EFFECTIVE SHEAR WILL BE MORE THAN ADEQUATE TO PROMOTE UPDRAFT ROTATION WITH A COUPLE OF THE MORE PERSISTENT CELLS POSSIBLY PRODUCING LARGE HAIL OR A SEVERE WIND GUST. LACK OF GREATER INSTABILITY AND STRONGER FORCING SHOULD KEEP SEVERE POTENTIAL LIMITED TO A FEW HOURS EITHER SIDE OF MAX HEATING. ...SERN LOWER MI/NRN IND/NWRN OH... LIMITED CLOUD COVER AND BOUNDARY LAYER HEATING SHOULD ALLOW FOR LAPSE RATES TO STEEPEN ACROSS LOWER MI AND PARTS OF THE UPPER MIDWEST AS CUT-OFF LOW SPREADS ESEWD DURING THE DAY. WEAK CAPE AND FORCING FOR ASCENT ON THE NOSE OF MID LEVEL JET STREAK DEVELOPING SEWD ACROSS IL/IND SHOULD SUPPORT LOW-TOPPED TSTM INITIATION WITH THE CHANCE FOR SCATTERED HAIL GIVEN LOW FREEZING LEVELS BENEATH/NEAR THE UPPER LOW. ...NERN KS TO MO... LOW LEVEL MOISTURE BEING TRANSPORTED BENEATH STRONG CAP WILL ENCOUNTER A ZONE OF FRONTOGENESIS ACROSS THE SCNTRL PLAINS/MO RIVER VALLEY FROM LATE TONIGHT INTO EARLY SUNDAY. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THIS PROCESS SHOULD ENHANCE THE CHANCES FOR ELEVATED TSTM DEVELOPMENT IN A BAND FROM EXTREME SERN NEB...ACROSS NERN KS...AND INTO NRN MO. IT IS POSSIBLE THAT ONE OR TWO STORMS COULD PRODUCE MARGINALLY SEVERE HAIL BEFORE DAYBREAK SUNDAY. ..CARBIN/TAYLOR.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 12:46:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 08:46:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221242 SWODY1 SPC AC 221239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0739 AM CDT SAT APR 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM FL TO SE VA.... ...SE ATLANTIC STATES TODAY... A SMALL MCS IS MOVING NEWD ACROSS NC/VA IN ASSOCIATION WITH AN MCV IN ADVANCE OF THE PRIMARY MID LEVEL TROUGH OVER GA. THIS INITIAL CONVECTION MAY PRODUCE MARGINAL SEVERE GUSTS AND SOME HAIL...THOUGH THE STORMS COULD MOVE ACROSS THE WARM SECTOR BEFORE SUBSTANTIAL SURFACE HEATING/DESTABILIZATION CAN TAKE PLACE. THE PRIMARY SEVERE STORM THREAT DURING THE DAY SHOULD EVOLVE FROM THE ONGOING CONVECTION OVER GA/SC IN ASSOCIATION WITH THE PRIMARY MID LEVEL TROUGH. THIS ACTIVITY WILL SPREAD NEWD AND SHOULD INTENSIFY BY LATE MORNING WHILE ENCOUNTERING STRONGER INSTABILITY OVER CENTRAL SC/NC. THE COMBINATION OF MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500 J/KG/ AND 35-45 KT LOW-MID LEVEL FLOW SHOULD SUPPORT A FEW BOWING LINE SEGMENTS...WHERE DAYTIME DESTABILIZATION OF THE BOUNDARY LAYER WILL ALLOW STRONGER DOWNDRAFTS AND MORE EFFICIENT MOMENTUM TRANSFER TO THE SURFACE. THE SEVERE THREAT SHOULD PERSIST THROUGH LATE AFTERNOON...AND THEN BEGIN TO DIMINISH THIS EVENING AS THE STRONGER CONVECTION MOVES OFFSHORE AND THE LOW LEVELS STABILIZE. THE INFLUENCE OF THE MID LEVEL TROUGH WILL EXTEND OVER N FL...WHERE ADDITIONAL THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE OUTFLOW BOUNDARY FROM THE MORNING STORMS ACROSS SW GA/FL PANHANDLE. OTHER ISOLATED SEVERE STORMS MAY FORM OVER THE INTERIOR PENINSULA DURING THE AFTERNOON IN ASSOCIATION WITH SEA BREEZE BOUNDARIES. AFTERNOON MLCAPE NEAR 1500 J/KG AND SOMEWHAT ENHANCED VERTICAL SHEAR ALONG AND E OF THE ATLANTIC COAST SEA BREEZE MAY PROVE SUFFICIENT FOR STORMS WITH SOME SUPERCELL CHARACTERISTICS. ...SE NM/W TX THIS EVENING/EARLY TONIGHT... A MID LEVEL SHORTWAVE RIDGE WILL MOVE E OF THE HIGH PLAINS BY AFTERNOON...WITH SWLY MID LEVEL FLOW CONTRIBUTING TO DEVELOPMENT OF A LEE TROUGH ACROSS ERN NM. MEANWHILE...BOUNDARY LAYER DEWPOINTS IN THE MID 40S TO UPPER 50S WILL SPREAD NWWD FROM THE MIDDLE RIO GRANDE VALLEY TO SE NM BY AFTERNOON. THIS MOISTURE...ALONG WITH SURFACE HEATING THROUGH BREAKS IN A BROAD CIRRUS PLUME...WILL RESULT IN POTENTIALLY MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500 J/KG/ BY LATE AFTERNOON NEAR AND IMMEDIATELY E OF THE LEE TROUGH. WIDELY SCATTERED THUNDERSTORMS MAY FORM LATE THIS AFTERNOON/EVENING ALONG THE LEE TROUGH INVOF SE NM...WHERE VERTICAL SHEAR AND INSTABILITY SHOULD BE AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS. THE PRIMARY SEVERE THREAT WILL BE LARGE HAIL INITIALLY...AND THEN A FEW DAMAGING GUSTS IF STORMS CAN GROW UPSCALE INTO ONE OR MORE SMALL MCS/S DURING THE EVENING WHILE SPREADING TOWARD W TX. ...ERN KS/WRN MO LATE TONIGHT... LOW-LEVEL MOISTURE SHOULD SPREAD NWD FROM TX TO THE ERN KS AREA BY LATER TONIGHT...WHEN THE LLJ WILL ENHANCE WAA ALONG AND N OF A BAROCLINIC ZONE ACROSS ERN KS/WRN MO. THE MOISTENING SHOULD BE SUFFICIENT FOR ELEVATED CONVECTION LATE TONIGHT...AND STEEP MID LEVEL LAPSE RATES MAY SUPPORT SOME HAIL WITH THE STRONGER STORMS. ...SRN LOWER MI AREA THIS AFTERNOON... SEVERAL SMALLER SCALE WAVES WILL CONTINUE TO ROTATE AROUND THE NRN WI CLOSED LOW WHILE IT DRIFTS SEWD TO LOWER MI BY TONIGHT. WITH DAYTIME HEATING...COLD MID LEVEL TEMPERATURES /NEAR -26 C AT 500 MB/ AND STEEP LOW-MID LEVEL LAPSE RATES WILL SUPPORT L0W-TOPPED THUNDERSTORMS CAPABLE OF PRODUCING MAINLY SMALL HAIL DURING THE AFTERNOON. ..THOMPSON/TAYLOR.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 17:05:04 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 13:05:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221700 SWODY1 SPC AC 221628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT SAT APR 22 2006 VALID 221630Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CAROLINAS INTO GA/FL... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OS SOUTHEAST LOWER MI INTO NORTHWEST OH... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WEST TX AND EASTERN NM... ...CAROLINAS... MORNING WATER VAPOR IMAGERY AND U/A ANALYSIS SHOWS UPPER RIDGE OVER THE CENTRAL UNITED STATES...AND A LARGE TROUGH FROM THE GREAT LAKES REGION ACROSS THE SOUTHEAST. PRIMARY SHORTWAVE TROUGH IS CURRENTLY OVER GA MOVING INTO THE CAROLINAS. THUNDERSTORMS ARE INTENSIFYING AHEAD OF THIS FEATURE ALONG THE SC/NC BORDER...WITH ISOLATED SEVERE STORMS EXPECTED THROUGH THE AFTERNOON INTO VA. SURFACE DEWPOINTS IN THE 60S AND WEAK DAYTIME HEATING WILL CONTRIBUTE TO MLCAPE VALUES OVER 1000 J/KG. RELATIVELY STRONG LOW/DEEP LAYER WIND FIELDS SHOULD AID CONVECTIVE ORGANIZATION WITH THE POTENTIAL FOR DAMAGING WINDS AND HAIL IN STRONGER CELLS. ...GA/FL... A CLUSTER OF STRONG THUNDERSTORMS IS ONGOING OVER THE EASTERN FL PANHANDLE. THESE STORMS WILL TRACK EASTWARD ACROSS NORTH FL EARLY THIS AFTERNOON...WHERE STRONG HEATING/DESTABILIZATION IS OCCURRING. POTENTIAL EXISTS FOR LOCALLY DAMAGING WINDS AND HAIL IN STRONGER CELLS BEFORE MOVING OFFSHORE. OTHER MORE ISOLATED STORMS MAY DEVELOP SOUTHWARD FROM THIS REGION ACROSS THE FL PENINSULA. WESTERLY FLOW WILL HELP TO MAXIMIZE CONVERGENCE ALONG THE EAST COAST SEA BREEZE THIS AFTERNOON AND EARLY EVENING. WET MICROBURSTS AND HAIL WOULD BE THE MAIN THREAT. REFER TO RECENT MCD NUMBER 615 FOR FURTHER DETAILS. ...EASTERN NM/WEST TX... CURRENT SHORTWAVE RIDGING ACROSS THE HIGH PLAINS WILL SHIFT EASTWARD TODAY DOWNSTREAM OF SOUTHWEST STATES UPPER TROUGH...WITH LEE TROUGH ACROSS THE SOUTHERN HIGH PLAINS. SOUTH/SOUTHEAST LOW LEVEL WINDS WILL SUPPORT A NORTHWARD TRANSPORT OF 50S F DEWPOINTS AND A POTENTIALLY UNSTABLE AIRMASS -- REF 12Z DEL RIO TX RAOB -- ACROSS THE SOUTHERN HIGH PLAINS. INITIAL CONVECTIVE DEVELOPMENT IS ANTICIPATED BY MID/LATE AFTERNOON ACROSS THE EASTERN NM PLAINS INTO FAR WEST TX/HIGHER TERRAIN OF SOUTHWEST TX...WITH THIS ACTIVITY SPREADING EASTWARD ACROSS WEST TX AND THE OK/TX PANHANDLES THIS EVENING. COMBINATION OF MODERATE INSTABILITY /1500-2000 J/KG MLCAPE/ AND VERTICAL SHEAR /25-30 KTS/ WILL FAVOR BOTH ORGANIZED MULTICELLS AND SUPERCELLS...WITH A PRIMARY HAZARD OF LARGE HAIL. IN ADDITION...AN INCREASING SOUTHERLY LOW LEVEL JET EARLY THIS EVENING MAY SUPPORT UPSCALE GROWTH AND ONE OR MORE SMALL MCS/S WITH A DAMAGING WIND THREAT AS ACTIVITY SPREADS ACROSS WEST TX. ...MI/OH... UPPER LOW CENTER IS FORECAST TO MOVE SLOWLY EASTWARD TODAY FROM WI INTO LOWER MI. STRONG DAYTIME HEATING IS OCCURRING AHEAD OF SYSTEM ACROSS SOUTHEAST LOWER MI AND NORTHWEST OH...WHERE STEEP LAPSE RATES AND MLCAPE VALUES OF 500-1000 J/KG WILL BE PRESENT. MODELS GENERALLY AGREE ON DEVELOPMENT OF SCATTERED THUNDERSTORMS LATER THIS AFTERNOON IN THIS REGION...CONTINUING INTO THE EARLY EVENING. LARGE HAIL SHOULD BE THE MAIN THREAT IN THIS REGION. ...CENTRAL CA... UPPER TROUGH REMAINS OVER CENTRAL CA TODAY...WITH COLD TEMPERATURES ALOFT AND STEEP LAPSE RATES IN PLACE. POCKETS OF DAYTIME HEATING WILL HELP TO DESTABILIZE AIR MASS...LEADING TO ISOLATED THUNDERSTORMS. MODEL GUIDANCE SUGGESTS PRIMARY THREAT AREA WILL BE ALONG THE FOOTHILLS OF THE SIERRAS WHERE UPSLOPE FLOW WILL ENHANCE CONVECTIVE POTENTIAL. ...KS/MO OVERNIGHT... LOW LEVEL WARM ADVECTION ZONE IS FORECAST TO DEVELOP ACROSS PARTS OF KS/MO LATER TONIGHT AS SURFACE COLD FRONT SAGS INTO REGION. INFLUX OF RELATIVELY MOIST/UNSTABLE AIR WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT MAINLY AFTER 06Z. FORECAST SOUNDINGS APPEAR FAVORABLE FOR LARGE HAIL IN STRONGEST STORMS. ..HART/GUYER.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 19:55:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 15:55:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221952 SWODY1 SPC AC 221950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SAT APR 22 2006 VALID 222000Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC AND SERN STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL GRTLKS REGION... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SRN HIGH PLAINS... ...MID-ATLANTIC AND SERN STATES... VORT MAX CONTINUES TO ROTATE ENEWD INTO UPSTATE SC THIS AFTN. WARM CONVEYOR AHEAD OF THIS FEATURE HAS SUPPORTED MULTIPLE BANDS OF STRONG-SEVERE TSTMS FROM THE DELMARVA REGION SWD INTO THE ERN CAROLINAS. STRONGEST LARGE SCALE ASCENT WILL BE MOVING QUICKLY NEWD INTO THE DELMARVA REGION AND THE ERN PORTIONS OF NC LATE THIS AFTN. SMALL SCALE LEWPS/BOWS MAY DEVELOP WITHIN THE BANDS OF TSTMS... GIVING LOCAL DAMAGING WINDS AND PERHAPS HAIL. UPSTREAM...AIR MASS SEEMS TO BE RECOVERING SOMEWHAT ALONG/JUST AHEAD OF THE PRIMARY COLD FRONT/ALONG AND E OF THE SRN APPALACHIAN CREST. DESPITE THE FACT THAT MAIN LLJ AXIS BEGINS TO SHIFT NEWD AWAY FROM THIS REGION...STEEP LAPSE RATES AND MODEST WSWLY UNIDIRECTIONAL FLOW MAY BE SUFFICIENT FOR ONE OR TWO SEVERE TSTMS WITH DAMAGING WINDS/HAIL ACROSS CNTRL NC-SC AND PARTS OF SERN/SCNTRL GA THROUGH THE EVENING HOURS. ...NRN/CNTRL FL... FARTHER S...STRONGER TSTMS HAVE BEEN FAVORING THE OUTFLOW BOUNDARY MOVING SWD THROUGH NRN FL AND ALONG THE SEABREEZE SOUTH OF THE CAPE. VERTICAL SHEAR WILL SUPPORT MAINLY MULTI-CELL TSTMS WITH BRIEF SUPERCELL STRUCTURES. DAMAGING WINDS AND PERHAPS HAIL SEEM TO BE THE PRIMARY SEVERE RISKS THROUGH EARLY EVENING. ...SRN HIGH PLAINS... MORE QUALITY LOW-LEVEL MOISTURE APPEARS TO HAVE ADVECTED ACROSS THE EDWARDS PLATEAU AND ALONG THE PECOS RVR VLY INTO SERN NM WHERE MID-AFTN SFC DEW POINTS WERE HOLDING IN THE MIDDLE 50S TO LOWER 60S BENEATH THE STRONG CAP IN PLACE. DIFFERENTIAL HEATING AND FAVORABLE DIURNAL CIRCULATION ARE CONTRIBUTING TO CONVECTION ALONG THE SRN NM AND SWRN TX MOUNTAINS. UPPER RIDGE AXIS SHOULD EDGE EWD LATER THIS AFTN...PROVIDING A MORE FAVORABLE ENVIRONMENT FOR THIS CONVECTION TO VENTILATE AND GROW INTO STORMS. CONTINUED HEATING ON THE ADJACENT PLAINS WILL PROBABLY WEAKEN THE CAP TO THE POINT WHERE STORMS WILL MOVE OFF THE MOUNTAINS AND SURVIVE. WHITE SANDS PROFILER SHOWS A RATHER DEEP SLY UNIDIRECTIONAL FLOW REGIME WITH VERTICAL SHEAR OF AROUND 35-40 KTS. TSTMS WILL PROBABLY DEVELOP INTO LINE SEGMENTS WITH PERHAPS BRIEF SUPERCELL STRUCTURES LATE THIS AFTN WITH LARGE HAIL THE PRIMARY THREAT. ACTIVITY MAY DEVELOP UPSCALE INTO ONE OR MORE MCS/S AND MOVE SLOWLY ENEWD THROUGH ERN NM AND WRN TX THROUGH THE EVENING WITH HAIL AND HIGH WINDS. ...CNTRL GRTLKS... COOLING ALOFT AND LARGE SCALE ASCENT ASSOCIATED WITH AN IMPULSE ROTATING AROUND THE GRTLKS UPPER LOW HAS BEEN SUPPORTING DEEPENING CONVECTION ACROSS THE REGION THIS AFTN. HAIL WILL BE THE PRIMARY THREAT WITH THIS ACTIVITY GIVEN THE STEEP LAPSE RATES. ADDITIONAL CONVECTION IS APT TO DEVELOP FARTHER SW WITHIN LOW-LEVEL THERMAL RIDGE ACROSS SRN MI INTO NRN IND AS A 70 KT JET STREAK NOSES SEWD LATER THIS AFTN. HERE...VERTICAL WIND PROFILES APPEAR SUPPORTIVE FOR LOW-TOPPED SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND GUSTS. ...CNTRL CA VLYS... UPPER TROUGH REMAINS OVER CENTRAL CA...WITH COLD TEMPERATURES ALOFT AND STEEP LAPSE RATES IN PLACE. POCKETS OF HEATING WILL HELP TO DESTABILIZE AIR MASS...LEADING TO ISOLATED THUNDERSTORMS. MODEL GUIDANCE SUGGESTS PRIMARY THREAT AREA WILL BE ALONG THE FOOTHILLS OF THE SIERRAS WHERE UPSLOPE FLOW WILL ENHANCE CONVECTIVE POTENTIAL. ...CNTRL PLAINS... LOW-LEVEL WARM ADVECTION ZONE IS INCREASING ACROSS PARTS OF KS/MO AS SURFACE COLD FRONT SAGS INTO REGION. INFLUX OF RELATIVELY MOIST/UNSTABLE AIR WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE EVENING. FORECAST SOUNDINGS APPEAR FAVORABLE FOR LARGE HAIL IN STRONGEST STORMS. ..RACY.. 04/22/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:01:47 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:01:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230057 SWODY1 SPC AC 230056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 06:15:18 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 02:15:18 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230609 SWODY1 SPC AC 230607 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SUN APR 23 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF PA AND NJ... ...CNTRL AND SRN PLAINS... AN UPPER-LEVEL TROUGH OVER THE WEST COAST IS FORECAST TO SLOWLY DRIFT ENEWD WITH HEIGHTS GRADUALLY FALLING ACROSS THE HIGH PLAINS. THIS WILL AID THE DEVELOPMENT OF A LEE SFC LOW OVER WRN KS WITH A SFC TROUGH/DRYLINE EXTENDING SWD INTO THE TX PANHANDLE. IN RESPONSE TO THE HEIGHT FALLS...A 50 KT LOW-LEVEL JET EARLY IN THE PERIOD WILL CONTINUE MOISTURE ADVECTION ACROSS WEST TX AND WRN KS THIS MORNING WITH SFC DEWPOINTS LIKELY INCREASING INTO THE 55 TO 60 F RANGE ACROSS MUCH OF THE REGION. AS SFC TEMPS WARM BY MIDDAY SUNDAY...MODERATE INSTABILITY SHOULD EXIST ALONG AND EAST OF A WEST TX/SWRN KS DRYLINE AND SOUTH OF A STATIONARY FRONT EXTENDING EWD ACROSS CNTRL KS. EARLY AFTERNOON FORECAST SOUNDINGS ACROSS THE WARM SECTOR SHOW A CAPPING INVERSION IN PLACE. THIS COMBINED WITH THE INFLUENCE OF THE UPPER-RIDGE SHOULD HOLD CONVECTIVE INITIATION OFF UNTIL THE MID-AFTERNO0N. THE MOST LIKELY AREAS FOR INITIAL CONVECTIVE DEVELOPMENT WOULD BE ALONG AND JUST EAST OF THE DRYLINE AND POSSIBLY ALONG THE BOUNDARY IN CNTRL AND ERN KS. FORECAST SOUNDINGS ACROSS THE REGION SHOW MODERATE DEEP LAYER SHEAR WHICH WITH THE INSTABILITY SHOULD BE ADEQUATE FOR SUPERCELL DEVELOPMENT IN THE LATE AFTERNOON AND EARLY EVENING. IN ADDITION...MODEL FORECASTS SHOW A PLUME OF VERY STEEP LAPSE RATES EXTENDING NEWD FROM THE SRN ROCKIES INTO THE CNTRL PLAINS. THIS SUGGESTS LARGE HAIL WILL BE LIKELY WITH THE STRONGER STORMS. IN ADDITION...AN ISOLATED TORNADO THREAT MAY ALSO DEVELOP IN SW KS AND ACROSS THE ERN TX AND OK PANHANDLES BY EARLY EVENING AS THE STORMS MOVE EWD INTO THE MOIST AXIS AND THE LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE REGION. ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE WITH THE STRONGER SUPERCELL STORMS. AS STORMS INCREASE IN COVERAGE AND MOVE EWD INTO THE GREATER LOW-LEVEL MOISTURE...MCS DEVELOPMENT APPEARS LIKELY DURING THE EVENING. THE SEVERE THREAT COULD CONTINUE INTO WCNTRL OK AND ACROSS SCNTRL KS OVERNIGHT BUT THE THREAT SHOULD BECOME INCREASINGLY MARGINAL AFTER MIDNIGHT DUE TO DECREASING INSTABILITY. ...OZARK PLATEAU... AN UPPER-LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE PLAINS TODAY WITH NWLY FLOW ALOFT IN PLACE ACROSS THE OZARKS. AS SFC TEMPS WARM...MODERATE INSTABILITY SHOULD DEVELOP ALONG AND SOUTH OF A STATIONARY FRONTAL BOUNDARY EXTENDING EWD ACROSS SCNTRL MO. LOW-LEVEL CONVERGENCE IN THE AFTERNOON SHOULD BE STRONG ENOUGH TO OVERCOME A WEAK CAPPING INVERSION ALLOWING ISOLATED TO SCATTERED THUNDERSTORMS TO INITIATE. FORECAST SOUNDINGS ALONG THE BOUNDARY IN SCNTRL MO THIS AFTERNOON SHOW MODERATE VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES. THIS COMBINED WITH THE INSTABILITY SHOULD BE SUFFICIENT FOR ISOLATED SUPERCELL DEVELOPMENT DURING THE LATE AFTERNOON AND EARLY EVENING. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH DURING THE EVENING AS THE UPPER-RIDGE DRIFTS SLOWLY EWD AND INSTABILITY DECREASES ACROSS THE REGION. ...PA/NJ... AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL SHIFT ESEWD TODAY. IN RESPONSE...MID-LEVEL TEMPS WILL DROP FROM WEST TO EAST ACROSS THE CNTRL APPALACHIAN MTNS DURING THE AFTERNOON. THIS COMBINED WITH STRONG LARGE-SCALE ASCENT WILL MAKE THUNDERSTORM DEVELOPMENT LIKELY IN THE AFTERNOON. FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES AND MODERATE VERTICAL SHEAR WHICH SHOULD BE FAVORABLE FOR LARGE HAIL WITH STORMS THAT MOVE EWD ACROSS PA AND POSSIBLY AS FAR EAST AS WRN NJ DURING THE LATE AFTERNOON. HOWEVER...AS SFC TEMPS COOL IN THE EARLY EVENING...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 16:41:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 12:41:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231633 SWODY1 SPC AC 231632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT SUN APR 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL/SOUTHERN PLAINS... ...TX/OK/SRN KS... LARGE UPPER RIDGE REMAINS OVER THE CENTRAL UNITED STATES TODAY... WITH DEEP UPPER LOWS OVER CA...AND LOWER MI. CONTINUED SOUTHERLY LOW LEVEL WINDS ACROSS THE SOUTHERN PLAINS WILL MAINTAIN WIDESPREAD MID 50S TO LOWER 60S DEWPOINTS FROM KS INTO TX. STEEP LAPSE RATES AND STRONG DAYTIME HEATING SHOULD RESULT IN MLCAPE VALUES OF 1500-2000 J/KG ALONG AND EAST OF DRYLINE ALONG THE TX/NM BORDER INTO WESTERN KS. MORNING SOUNDINGS SHOW WARM 700MB TEMPERATURES ACROSS THIS REGION...BUT A GENERAL COOLING IS EXPECTED BY LATE AFTERNOON AS UPPER TROUGH SHIFTS SLOWLY EASTWARD AND SHORTWAVE TROUGH OVER MEXICO LIFTS NORTHEASTWARD. THIS SHOULD AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS FROM SOUTHWEST KS INTO THE NORTHERN/CENTRAL TX PANHANDLE...AND ISOLATED STORMS FROM THERE SOUTHWARD. DEEP LAYER VERTICAL SHEAR PROFILES OF 25-35 KNOTS WILL FAVOR ORGANIZED AND ISOLATED SUPERCELLULAR STRUCTURES CAPABLE OF LARGE HAIL AND DAMAGING WINDS. STORMS WILL LIKELY BE RATHER HIGH-BASED...ENHANCING THE THREAT OF DAMAGING WINDS. ACTIVITY IS EXPECTED TO SPREAD EASTWARD INTO PARTS OF WESTERN OK AND SOUTH CENTRAL KS DURING THE EVENING. ...SRN NEB/NRN KS... LATEST SURFACE ANALYSIS SHOWS WARM FRONT EXTENDING ACROSS CENTRAL KS INTO CENTRAL MO. STRONG DAYTIME HEATING IS OCCURRING NORTH OF BOUNDARY...WHERE WEAKER CAP AND ENHANCED LOW LEVEL WARM ADVECTION WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING. FAVORABLE SHEAR PROFILES IN THIS REGION SUGGEST A POTENTIAL FOR SUPERCELLS CAPABLE OF LARGE HAIL. IF ACTIVITY CAN ORGANIZE AND PROPAGATE EASTWARD ALONG BOUNDARY...DAMAGING WIND THREAT WOULD ALSO INCREASE. ...MO/IL/KS/TN... EASTWARD EXTENT OF SURFACE WARM FRONT LIES ACROSS CENTRAL MO INTO CENTRAL KY. AIR MASS ALONG AND SOUTH OF BOUNDARY WILL BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS IN THE 50S AND MLCAPE OVER 1000 J/KG. SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THIS AXIS...WITH LARGE HAIL POSSIBLE IN STRONGER CELLS. ...OH/PA/NY/VA/MD... FRONTAL BAND CONTINUES TO PUSH EASTWARD ACROSS EASTERN PA/CENTRAL NY. CLEARING SKIES BEHIND THIS ACTIVITY WILL ALLOW AIR MASS TO DESTABILIZE ACROSS PARTS OF MID ATLANTIC REGION THIS AFTERNOON. HOWEVER...LOW LEVEL MOISTURE IS WEAK AND DECREASING WITH TIME. PRESENT INDICATIONS ARE THAT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE IN THIS AREA...WITH HAIL POSSIBLE IN STRONGEST CELLS. HOWEVER...AN ORGANIZED SEVERE THREAT IS NOT CURRENTLY ANTICIPATED. ...FL... WARM/MOIST LOW LEVEL AIR MASS REMAINS IN PLACE OVER THE SOUTHERN FL PENINSULA TODAY...WHERE SCATTERED AFTERNOON THUNDERSTORMS ARE POSSIBLE. CONVERGENCE ALONG SOUTHEAST COAST SEA BREEZE...COMBINED WITH 30KT NORTHWEST FLOW ALOFT MAY RESULT IN ISOLATED STRONG STORMS CAPABLE OF GUSTY WINDS OR HAIL. ..HART/GUYER.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 20:02:01 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 16:02:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231955 SWODY1 SPC AC 231953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT SUN APR 23 2006 VALID 232000Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN HIGH PLAINS...CNTRL PLAINS...OZARKS AND THE LWR OH VLY... ...OZARKS EWD INTO LWR OH/TN VLYS THIS AFTN/EVE... UPPER LEVEL JETSTREAK TIED TO THE GRTLKS UPPER LOW HAS MAINTAINED A SWLY LLJ ACROSS THE SRN PLAINS INTO THE OZARKS THIS AFTN. UNSTABLE PARCELS HAVE BEEN REACHING THEIR LFC ACROSS CNTRL/SWRN MO AND NERN OK AND MOSTLY ELEVATED TSTMS HAVE BEEN PRODUCING SEVERE HAIL THIS AFTN. THOUGH THE HIGHER PROBABILITIES FOR SEVERE WEATHER WILL EXIST CLOSER TO THE INSTABILITY AXIS UPSTREAM...A FEW STRONGER STORMS ARE YET POSSIBLE EWD ACROSS THE TN/LWR OH VLYS THROUGH EVENING. ...CNTRL PLAINS TO THE OZARKS LATE THIS AFTN/TONIGHT... WATER VAPOR IMAGERY SHOWS A WEAK IMPULSE ROTATING NEWD ACROSS THE SRN ROCKIES THAT WILL MOVE INTO ERN CO LATER THIS EVENING. LARGE SCALE ASCENT ASSOCIATED WITH THIS FEATURE PROBABLY HAS CONTRIBUTED TO THE CONSIDERABLE HIGH-BASED CONVECTION OVER NERN NM AND ERN CO THIS AFTN. SFC ANALYSIS SHOWS THAT THE DRY HIGH PLAINS BOUNDARY LAYER WAS ADVECTING NEWD INTO THE NRN TX PNHDL AND SWRN KS WITH STRONGEST MASS CONVERGENCE DEVELOPING VCNTY THE WARM FRONT ACROSS WCNTRL-NCNTRL KS. THE WARM SECTOR CONTINUES TO DESTABILIZE OWING TO UNABATED HEATING AND SFC DEW POINTS REMAINING IN THE MID-UPPER 50S. AS CINH CONTINUES TO ERODE...THE HIGH-BASED CONVECTION APPROACHING FROM THE WEST WILL LIKELY GROW INTO THE UNSTABLE BOUNDARY LAYER AND INTENSIFY OVER WCNTRL/NWRN KS. OTHER STORMS WILL TEND TO DEVELOP ALONG/SWWD ALONG THE DRYLINE INTO SWRN KS AND THE TX/OK PNHDLS DURING THE EVENING. VERTICAL SHEAR REMAINS MARGINAL WITH MOST PROFILERS IN KS/OK SHOWING 30-35 KTS OF 6KM SHEAR. THUS...TSTMS WILL PROBABLY TEND TO CLUSTER AND BECOME OUTFLOW-DOMINANT WITH MAINLY LARGE HAIL AND DAMAGING WIND THREATS. GIVEN THE MAINTENANCE OF A SLY LLJ IMPINGING ON THE WARM FRONT OVERNIGHT...IT IS REASONABLE TO EXPECT TSTMS TO DEVELOP ESEWD ACROSS CNTRL KS AND INTO PARTS OF THE OZARKS THROUGH THE OVERNIGHT. STRONGER STORMS WILL CONTINUE TO HAVE A HAIL/GUSTY WIND THREAT. STORMS FARTHER S SHOULD WEAKEN WITH TIME AS THE DRYLINE RETREATS AND MOST OF THE MASS CONVERGENCE BECOMES CONFINED NE OF THE REGION. ...SRN HIGH PLAINS... LOW-LEVEL MOISTURE CONTINUES TO HUG THE HIGHER SWRN TX/SERN NM TERRAIN WHERE DIURNAL UPSLOPE CIRCULATION IS BEING ENHANCED BY AN UPSTREAM MEXICAN SHORTWAVE TROUGH. STRONG HEATING AND WEAK LARGE SCALE ASCENT SHOULD BE SUFFICIENT FOR MOUNTAIN CONVECTION TO SURVIVE ONTO THE PLAINS AGAIN THIS EVENING. THOUGH MID-AFTN VERTICAL SHEAR IS MARGINAL...THE FLOW ALOFT SHOULD INCREASE AS THE MEXICAN SHORTWAVE APPROACHES THE REGION. THUS...SUPERCELLS WILL BE POSSIBLE WITH LARGE HAIL AND DAMAGING WINDS. ...NRN PA/WRN NY... H5 SPEED MAX ROTATING AROUND THE PERIPHERY OF THE UPPER LOW CONTINUES TO DIG INTO THE UPPER OH VLY. RESIDUAL BOUNDARY LAYER DEW POINTS IN THE UPPER 40S BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES AND LOCAL SURFACE CONVERGENCE ALONG ATTENDANT FRONT WILL BE FAVORABLE FOR DIURNALLY-ENHANCED TSTMS PRODUCING MARGINALLY SEVERE HAIL OR GUSTY WINDS ACROSS MAINLY WRN NY THIS EVENING. ...NRN GRT BASIN... VORT MAX ROTATING AROUND THE COMPLEX UPPER LOW OVE SRN NV IS ENHANCING CONVECTION WITHIN A BROAD DEFORMATION ZONE ACROSS CNTRL/NERN NV THIS AFTN. STEEP LAPSE RATES AND PRESENCE OF DEEP ASCENT MAY AUGMENT HAIL PRODUCTION WITH ISOLD STORMS. ..RACY.. 04/23/2006  From SwoDy1 at goshenarc.org Mon Apr 24 01:05:36 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 21:05:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240101 SWODY1 SPC AC 240100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SUN APR 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE COLORADO... ...ERN KS/ERN OK/OZARK PLATEAU... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE PLAINS STATES WITH A PLUME OF MID-LEVEL MOISTURE EXTENDING EWD FROM SRN CO ACROSS SRN KS. AN MCS IS DEVELOPING IN THE MOIST PLUME ALONG THE AXIS OF THE RIDGE JUST SOUTH OF A FRONTAL BOUNDARY. THIS ACTIVITY WILL CONTINUE EWD ACROSS ERN KS AND NRN OK MOVING INTO INCREASING SFC DEWPOINTS AND MODERATE INSTABILITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES OF 30-35 KT AS SHOWN ON REGIONAL PROFILERS SHOULD BE SUFFICIENT FOR SUPERCELLS WITH STORMS THAT REMAIN DISCRETE OVER THE NEXT FEW HOURS. SEVERE MULTICELL STORMS AND/OR BOW ECHOES WILL ALSO BE LIKELY ESPECIALLY IN THE MORE INTENSE LINE SEGMENTS. THE GREATEST SEVERE THREAT SHOULD BE LARGE HAIL DUE TO THE STEEP LAPSE RATES IN PLACE BUT ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS ACROSS THE REGION LATER THIS EVENING. THE MCS SHOULD GRADUALLY MOVE EWD INTO SRN AND CNTRL MO OVERNIGHT WITH AN ISOLATED SEVERE THREAT CONTINUING. HOWEVER...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL AFTER MIDNIGHT. ...WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS SOUTHWEST FLOW IN PLACE ACROSS THE WRN PORTION OF THE SRN PLAINS WITH A DRY SLOT MOVING EWD ACROSS WEST TX. ISOLATED THUNDERSTORMS ARE DEVELOPING IN THE DRY SLOT NEAR A RETREATING DRYLINE. AS THE CONVECTION MOVES INTO INCREASING INSTABILITY THIS EVENING...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE ENOUGH FOR LARGE HAIL AND STRONG WIND GUSTS. HOWEVER...THE ACTIVITY SHOULD GRADUALLY WEAKEN LATER THIS EVENING DUE TO DECREASING INSTABILITY. ...NE CO/SW NEB... SSWLY FLOW IS CURRENTLY IN PLACE ACROSS NERN CO AHEAD OF AN UPPER-LOW DRIFTING EWD ACROSS NWRN AZ. A COLD FRONT IS MOVING SWD ACROSS ERN CO AND SCATTERED THUNDERSTORMS ARE DEVELOPING NORTH OF THE BOUNDARY ACROSS NERN CO WHERE SFC DEWPOINTS ARE IN THE 40S F. THE BOULDER WSR-88D VWP CURRENTLY SHOWS BACKED LOW-LEVEL FLOW WITH STRONG VEERING WIND PROFILES THROUGH 6 KM. THIS SUGGESTS THE SHEAR COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES SHOWN ON OBJECTIVE ANALYSIS SHOULD BE SUFFICIENT FOR SUPERCELL WITH A POTENTIAL FOR LARGE HAIL OVER THE NEXT FEW HOURS. HOWEVER...THE STORMS SHOULD EVENTUALLY WEAKEN LATER THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 03:06:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 23:06:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240301 SWODY1 SPC AC 240300 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1000 PM CDT SUN APR 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE COLORADO... CORRECTED TO REMOVE EXTRA THUNDER POINTS OVER CO ...ERN KS/ERN OK/OZARK PLATEAU... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE PLAINS STATES WITH A PLUME OF MID-LEVEL MOISTURE EXTENDING EWD FROM SRN CO ACROSS SRN KS. AN MCS IS DEVELOPING IN THE MOIST PLUME ALONG THE AXIS OF THE RIDGE JUST SOUTH OF A FRONTAL BOUNDARY. THIS ACTIVITY WILL CONTINUE EWD ACROSS ERN KS AND NRN OK MOVING INTO INCREASING SFC DEWPOINTS AND MODERATE INSTABILITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES OF 30-35 KT AS SHOWN ON REGIONAL PROFILERS SHOULD BE SUFFICIENT FOR SUPERCELLS WITH STORMS THAT REMAIN DISCRETE OVER THE NEXT FEW HOURS. SEVERE MULTICELL STORMS AND/OR BOW ECHOES WILL ALSO BE LIKELY ESPECIALLY IN THE MORE INTENSE LINE SEGMENTS. THE GREATEST SEVERE THREAT SHOULD BE LARGE HAIL DUE TO THE STEEP LAPSE RATES IN PLACE BUT ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS ACROSS THE REGION LATER THIS EVENING. THE MCS SHOULD GRADUALLY MOVE EWD INTO SRN AND CNTRL MO OVERNIGHT WITH AN ISOLATED SEVERE THREAT CONTINUING. HOWEVER...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL AFTER MIDNIGHT. ...WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS SOUTHWEST FLOW IN PLACE ACROSS THE WRN PORTION OF THE SRN PLAINS WITH A DRY SLOT MOVING EWD ACROSS WEST TX. ISOLATED THUNDERSTORMS ARE DEVELOPING IN THE DRY SLOT NEAR A RETREATING DRYLINE. AS THE CONVECTION MOVES INTO INCREASING INSTABILITY THIS EVENING...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE ENOUGH FOR LARGE HAIL AND STRONG WIND GUSTS. HOWEVER...THE ACTIVITY SHOULD GRADUALLY WEAKEN LATER THIS EVENING DUE TO DECREASING INSTABILITY. ...NE CO/SW NEB... SSWLY FLOW IS CURRENTLY IN PLACE ACROSS NERN CO AHEAD OF AN UPPER-LOW DRIFTING EWD ACROSS NWRN AZ. A COLD FRONT IS MOVING SWD ACROSS ERN CO AND SCATTERED THUNDERSTORMS ARE DEVELOPING NORTH OF THE BOUNDARY ACROSS NERN CO WHERE SFC DEWPOINTS ARE IN THE 40S F. THE BOULDER WSR-88D VWP CURRENTLY SHOWS BACKED LOW-LEVEL FLOW WITH STRONG VEERING WIND PROFILES THROUGH 6 KM. THIS SUGGESTS THE SHEAR COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES SHOWN ON OBJECTIVE ANALYSIS SHOULD BE SUFFICIENT FOR SUPERCELL WITH A POTENTIAL FOR LARGE HAIL OVER THE NEXT FEW HOURS. HOWEVER...THE STORMS SHOULD EVENTUALLY WEAKEN LATER THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 06:04:56 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 02:04:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240600 SWODY1 SPC AC 240559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT MON APR 24 2006 VALID 241200Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KANSAS AND OKLAHOMA... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS...SRN PLAINS AND MID-MS VALLEY... ...GREAT PLAINS/MID-MS VALLEY... AN UPPER-LEVEL TROUGH OVER THE SWRN STATES IS FORECAST TO EJECT ENEWD ACROSS THE ROCKIES TODAY. A 70 KT MID-LEVEL JET ASSOCIATED WITH THE TROUGH WILL NOSE INTO THE CNTRL PLAINS THIS AFTERNOON INCREASING VERTICAL SHEAR PROFILES. THIS COMBINED WITH STRONG LARGE-SCALE ASCENT AND A VERY UNSTABLE AIRMASS WILL LIKELY RESULT IN WIDESPREAD SEVERE WEATHER ACROSS THE REGION THIS AFTERNOON AND TONIGHT. SEVERAL MESOSCALE CONVECTIVE SYSTEMS SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD. MODEL FORECASTS VALID AT 12Z GENERALLY AGREE KEEPING MOST OF THE CONVECTIVE CLUSTERS ACROSS SRN NEB...NERN KS AND WRN MO. THE LACK OF CONVECTION ALONG WITH A CAPPING INVERSION SHOULD KEEP THE AIRMASS ACROSS THE MODERATE RISK AREA UNDISTURBED THROUGH MIDDAY. CONTINUED MOISTURE ADVECTION DURING THE DAY SHOULD BRING SFC DEWPOINTS IN THE MID 60S F AS FAR NORTH AS CNTRL KS. THIS SHOULD RESULT IN MODERATE TO STRONG INSTABILITY BY AFTERNOON ACROSS THE WARM SECTOR. AS A COLD FRONT APPROACHES CNTRL KS DURING THE AFTERNOON...INCREASING LOW-LEVEL CONVERGENCE AND THE WEAKENING CAP SHOULD RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT WITH STORMS DEVELOPING SWD TOWARD THE OK STATELINE. VERTICAL SHEAR SHOULD GRADUALLY INCREASE DURING THE DAY AS A MID-LEVEL JET PUNCHES INTO THE REGION. FORECAST SOUNDINGS AT 21Z ACROSS THE MODERATE RISK AREA SHOW 0-6 KM SHEAR VALUES OF 40 TO 50 KT WHICH COMBINED WITH STEEP LAPSE RATES AND STRONG INSTABILITY SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE MORE INTENSE SUPERCELLS WILL ALSO HAVE A POTENTIAL FOR VERY LARGE HAIL AND TORNADOES...ESPECIALLY AS THE LOW-LEVEL JET EXPANDS NWD ACROSS THE REGION IN THE LATE AFTERNOON AND EARLY EVENING. A LINEAR MCS SHOULD GRADUALLY DEVELOP AS SUGGESTED BY THE WRF-NMM/NAM AND GFS WITH THE WIND DAMAGE POTENTIAL BECOMING ENHANCED DURING THE EVENING HOURS ACROSS THE OZARK PLATEAU. ALTHOUGH THE MCS MAY CONTINUE WITH THE MCS INTO SRN MO AND NRN AR AFTER MIDNIGHT...ANY SEVERE THREAT SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. FURTHER SOUTH ACROSS OK AND NRN/CNTRL TX STRONG INSTABILITY WILL LIKELY BE IN PLACE WITH SFC DEWPOINTS IN THE MID TO UPPER 60S F. FORECAST SOUNDINGS SHOW A CAPPING INVERSION REMAINING IN PLACE THROUGH MUCH OF THE AFTERNOON AHEAD OF A DRYLINE EXTENDING SSWWD FROM NEAR WICHITA FALLS INTO THE TX HILL COUNTRY. AS LOW-LEVEL CONVERGENCE INCREASES EAST OF THE DRYLINE...ISOLATED THUNDERSTORMS SHOULD INITIATE AND MOVE EWD ACROSS THE I-35 CORRIDOR. STRONG INSTABILITY...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL AND ISOLATED WIND DAMAGE. A FEW TORNADOES WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS IN NCNTRL AND NERN OK WHERE THE LOW-LEVEL JET IS FORECAST TO STRENGTHEN IN THE EARLY EVENING. DECREASING INSTABILITY AND A STRENGTHENING CAPPING INVERSION SHOULD RESULT IN A GRADUAL DECREASE OF THE SEVERE THREAT BY LATE EVENING. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 12:35:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 08:35:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241231 SWODY1 SPC AC 241229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT MON APR 24 2006 VALID 241300Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF NRN OK AND SRN KS.... ...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT ELSEWHERE FROM NRN KS SWD TO CENTRAL TX...AND EWD TO NW AR/MO/SRN IL.... ...SYNOPSIS... THE CLOSED MID LEVEL LOW OVER THE SRN GREAT BASIN IS EVOLVING INTO AN OPEN WAVE...AND THIS SYSTEM WILL EJECT EWD TO THE HIGH PLAINS BY TONIGHT. A SEPARATE NRN STREAM WAVE WILL MOVE FROM MANITOBA TO THE UPPER GREAT LAKES. IN THE WAKE OF THIS NRN STREAM TROUGH...A SURFACE RIDGE WILL BUILD SEWD ACROSS THE PLAINS...DRIVING A COLD FRONT SEWD ACROSS OK/NW TX AND THE MID MS VALLEY BY THE END OF THE PERIOD. AN INITIAL LEE CYCLONE OVER SW KS THIS MORNING IS EXPECTED TO DEVELOP EWD ALONG AN E-W BAROCLINIC ZONE ACROSS KS/MO...OR PERHAPS ALONG A COMPOSITE OUTFLOW BOUNDARY LINGERING ACROSS NRN OK...IN ADVANCE OF THE GREAT BASIN TROUGH. THE SURFACE LOW AND THESE SURFACE BOUNDARIES WILL FOCUS THE SEVERE STORM THREAT THROUGH EARLY TONIGHT ACROSS KS AND NRN OK. ...KS/OK/MO AREA THROUGH TONIGHT... THE FIRST MCS IN THE SEQUENCE HAS DISSIPATED OVER SE MO...LEAVING AN OUTFLOW BOUNDARY FROM NRN AR INTO NRN OK. A SECOND SMALL MCS IS WEAKENING OVER NE OK/NW AR...AND THIS CONVECTION IS REINFORCING THE EARLIER OUTFLOW ACROSS NRN OK. OTHER ELEVATED STORMS PERSIST ACROSS CENTRAL/NE KS AND SE NEB IN ASSOCIATION WITH WAA AND LIFT ALONG THE SURFACE COLD FRONT. GIVEN THE RELATIVELY WIDESPREAD CONVECTION ACROSS KS...THE EFFECTIVE SURFACE BOUNDARY MAY END UP BEING THE RESIDUAL OUTFLOW NEAR THE KS/OK BORDER BY AFTERNOON. A FEED OF UNDISTURBED WARM SECTOR AIR /WITH BOUNDARY LAYER DEWPOINTS OF 62-64 F/ WILL PERSIST TODAY ACROSS CENTRAL AND WRN OK INTO THE OUTFLOW BOUNDARY NEAR THE KS/OK BORDER. STRONG SURFACE HEATING BENEATH STEEP MID LEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPE VALUES OF 2000-3000 J/KG IN THE WARM SECTOR...AND PERHAPS 1000-2000 J/KG IN THE ZONE BETWEEN THE OUTFLOW BOUNDARY AND RESIDUAL E-W BAROCLINIC ZONE IN KS. THERE IS SOME UNCERTAINTY REGARDING THE EVOLUTION OF THE ONGOING STORMS IN KS. HOWEVER...IT APPEARS LIKELY THAT ADDITIONAL STORMS WILL FORM BY MID AFTERNOON NEAR THE SURFACE TRIPLE POINT...CLOSE TO A LINE FROM P28-END. INCREASING MID-UPPER WSWLY FLOW...ALONG WITH BACKED LOW-LEVEL WINDS NEAR THE OUTFLOW BOUNDARY AND E OF THE SURFACE LOW...WILL PROVIDE SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS. VERY LARGE HAIL AND A FEW TORNADOES WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING...ESPECIALLY IF THE OUTFLOW BOUNDARY CAN MAINTAIN ITS IDENTITY WITH A BELT OF BACKED LOW-LEVEL FLOW AND MID 60 DEWPOINTS. LATER DURING THE EVENING...CONVECTION SHOULD GROW UPSCALE INTO ANOTHER MCS WITH LARGE HAIL AND DAMAGING WINDS ACROSS SRN KS AND NRN OK...POSSIBLY REACHING SW MO AND NW AR LATE TONIGHT. OTHER MORE ISOLATED STORMS MAY FORM ALONG THE COLD FRONT OVERNIGHT INTO CENTRAL TX...WHILE THE ERN EXTENT OF THE SEVERE THREAT WILL BE LIMITED BY GRADUALLY WEAKENING INSTABILITY OVERNIGHT ACROSS MO/AR. ..THOMPSON/TAYLOR.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 16:27:13 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 12:27:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241623 SWODY1 SPC AC 241621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT MON APR 24 2006 VALID 241630Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SOUTH CENTRAL KS AND WESTERN/NORTHERN OK... ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX ACROSS MUCH OF OK/KS AND INTO THE MID MS VALLEY... ...REGIONAL SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING OVER PARTS OF KS/OK... ...KS/OK... LARGE UPPER TROUGH IS PRESENT THIS MORNING OVER THE WESTERN STATES...WITH BAND OF 40-60 KNOT SOUTHWESTERLY MID LEVEL WINDS EXTENDING FROM AZ/NM INTO WESTERN KS. THESE WIND FIELDS ARE FORECAST TO SHIFT EASTWARD BY THIS AFTERNOON ACROSS MUCH OF KS/OK...ALONG WITH INCREASED LARGE SCALE FORCING FOR ASCENT. SCATTERED THUNDERSTORMS WILL DEVELOP NEAR SURFACE LOW OVER SOUTHWEST KS...AND SOUTHWARD ALONG DRYLINE INTO ACROSS WESTERN OK. SIGNIFICANT SUPERCELLS CAPABLE OF VERY LARGE HAIL...DAMAGING WINDS...AND A FEW TORNADOES APPEAR POSSIBLE. MORNING SURFACE ANALYSIS SHOWS MULTIPLE OUTFLOW BOUNDARIES LYING ACROSS SOUTH CENTRAL KS AND NORTHERN OK. PRESENT INDICATIONS ARE THAT BACKED FLOW NORTH OF THESE BOUNDARIES WILL WEAKEN BUT REMAIN IN PLACE THROUGH THIS AFTERNOON. MODELS ALSO HINT AT SECONDARY SURFACE LOW DEVELOPMENT OVER SOUTHWEST OK ALONG APPROACHING COLD FRONT. THIS WILL TEND TO BACK LOW LEVEL WINDS FARTHER SOUTH ALONG DRYLINE ACROSS WESTERN OK AS WELL. INCREASING WIND FIELDS ALOFT THIS AFTERNOON WILL YIELD LOCAL EFFECTIVE HELICITY VALUES OVER 200 M2/S2 AND EFFECTIVE SHEAR OF 30-40 KNOTS ACROSS THIS REGION. THERMODYNAMIC PROFILES WILL BE EXTREMELY FAVORABLE FOR SEVERE STORMS AS SURFACE DEWPOINTS RISE THROUGH THE 60S BENEATH STEEP LAPSE RATES...WITH AFTERNOON MLCAPE VALUES EXCEEDING 3000 J/KG. EXPECT STORMS TO RAPIDLY INTENSIFY NEAR SURFACE LOW/OUTFLOW BOUNDARIES NEAR THE OK/KS BORDER BY MID AFTERNOON...WITH DEVELOPMENT SOUTHWARD ALONG DRYLINE BY EARLY EVENING. VERY LARGE HAIL WILL BE LIKELY...ALONG WITH THE POTENTIAL FOR DAMAGING WINDS AND A FEW TORNADOES. AT THIS TIME...GREATEST THREAT OF TORNADOES APPEARS TO BE IN VICINITY OF TRIPLE POINT/REMNANT OUTFLOW BOUNDARIES FROM SOUTH CENTRAL KS INTO NORTHWEST/NORTH CENTRAL OK. FRONTAL CONVERGENCE MAY TEND TO FOCUS STORMS INTO SQUALL LINE DURING THE EVENING WITH AN ENHANCED THREAT OF DAMAGING WINDS ACROSS MUCH CENTRAL/EASTERN OK AND SOUTHEAST KS. ...TX... STRONG HEATING ALONG SURFACE DRYLINE MAY ALSO RESULT IN ISOLATED SEVERE STORM DEVELOPMENT AS FAR SOUTH AS CENTRAL TX THIS AFTERNOON/EVENING. WARM TEMPERATURES ALOFT AND MINIMAL FORCING SUGGEST ACTIVITY WILL REMAIN VERY ISOLATED AND MAY WEAKEN SHORTLY AFTER SUNSET. ..HART/GUYER.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 22:38:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 18:38:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 242234 SWODY1 SPC AC 242233 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0533 PM CDT MON APR 24 2006 VALID 242000Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PORTIONS OF OK AND S-CNTRL KS... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PORTIONS OF THE CNTRL AND SRN PLAINS INTO THE MD MS VALLEY... ...CNTRL/SRN PLAINS... SURFACE ANALYSIS INDICATES COMPLEX SURFACE PATTERN THIS AFTERNOON ACROSS REGION. PRIMARY COLD FRONT APPEARS TO EXTEND FROM S-CNTRL/SERN NEB SSWWD TO LOW PRESSURE OVER NWRN OK AND THEN INTO THE SRN TX PNHDL. AN OUTFLOW BOUNDARY /SLOWLY SAGGING SWWD/ EXTENDS FROM THIS LOW PRESSURE AREA OVER NWRN OK ESEWD TO ONGOING MCS OVER NERN OK INTO NWRN AR. A SECONDARY LOW HAS BECOME BETTER DEFINED OVER SWRN OK AT INTERSECTION OF COLD FRONT WITH DRY LINE WHICH EXTENDS SWD INTO W-CNTRL TX. 18Z OUN SOUNDING INDICATES THAT BOUNDARY-LAYER HAS MOISTENED SINCE 12Z WITH DEWPOINTS IN THE MID TO UPPER 60S. THIS MOISTURE COUPLED WITH STEEP MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO A MODERATELY TO POTENTIALLY STRONGLY UNSTABLE AIR MASS WITH MLCAPES OF 2000-3000 J/KG. VISIBLE SATELLITE AND THIS SOUNDING DATA SUGGEST THAT DAYTIME HEATING HAS NEARLY ERODED REMAINING CAP ALONG DRY LINE AND OUTFLOW BOUNDARY WITH EXPLOSIVE TSTM DEVELOPMENT ANTICIPATED BY 21-22Z. GIVEN THE DEGREE OF INSTABILITY...SUPERCELLS CAPABLE OF VERY LARGE HAIL APPEAR LIKELY. WHILE DEEP-LAYER VERTICAL SHEAR WAS MARGINAL /30-35 KTS/ ON THE 18Z OUN SOUNDING...PROFILER/VAD DATA INDICATE THAT MID-LEVEL WIND FIELDS ARE INCREASING FROM THE W OVER THE CNTRL AND SRN HIGH PLAINS. IT APPEARS THE GREATEST POTENTIAL FOR A FEW TORNADOES WILL BE WITH STORMS THAT CAN INITIATE ALONG THE DRY LINE...MATURE AND THEN CROSS OR MOVE NEARLY ALONG OUTFLOW BOUNDARY OVER NWRN AND N-CNTRL OK. THIS TORNADO THREAT WILL ALSO EXIST THROUGH THE AFTERNOON INTO EVENING ALONG NARROW INSTABILITY AXIS INTO SWRN KS. MORE ISOLATED STORMS WILL ALSO BE POSSIBLE FROM SWRN OK INTO NWRN AND PERHAPS W-CNTRL TX FROM NEAR SECONDARY TRIPLE POINT SWD ALONG DRY LINE. THOUGH DEEP-LAYER VERTICAL SHEAR DECREASES WITH SWD EXTENT...THE DEGREE OF INSTABILITY SUGGESTS THE POTENTIAL FOR SUPERCELLS CAPABLE OF LARGE HAIL. FINALLY...ONGOING MCS OVER NERN OK INTO NWRN AR HAS ORGANIZED A COLD POOL SUFFICIENTLY THAT IT HAS STARTED TO FORWARD PROPAGATE THIS AFTERNOON. INFLUX OF MODERATE TO STRONG INSTABILITY FROM THE SW SHOULD MAINTAIN THIS COMPLEX SEWD ACROSS FAR ERN OK AND AR WITH A CONTINUED THREAT OF DAMAGING WINDS AND LARGE HAIL. ..MEAD.. 04/24/2006  From SwoDy1 at goshenarc.org Tue Apr 25 06:03:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 02:03:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250559 SWODY1 SPC AC 250557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT TUE APR 25 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...LOWER MS VALLEY...TN VALLEY AND CAROLINAS... ...LOWER MS VALLEY/SRN PLAINS... AT UPPER-LEVELS...A FLAT RIDGE OVER THE MS VALLEY EARLY IN THE PERIOD WILL WEAKEN AS A BROAD TROUGH DEVELOPS ACROSS THE PLAINS AND MOVES TOWARD THE MS VALLEY. AT THE SFC...A COLD FRONT WILL MOVE SEWD ACROSS THE SRN PLAINS/OZARKS AND A LINEAR MCS MAY BE ONGOING ALONG AND AHEAD OF THE BOUNDARY AT THE BEGINNING OF THE PERIOD. AHEAD OF THE MCS ACROSS THE LA AND TX COASTAL PLAINS...SFC HEATING AND DEWPOINTS IN THE 65 TO 70 F RANGE SHOULD RESULT IN MODERATE INSTABILITY BY MIDDAY. ALTHOUGH LARGE-SCALE ASCENT IS FORECAST TO BE WEAK...INCREASING LOW-LEVEL CONVERGENCE AHEAD OF THE FRONTAL ZONE SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION DURING THE AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW MODERATE VERTICAL SHEAR PROFILES AND STEEP MID-LEVEL LAPSE RATES SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL ESPECIALLY UPON INITIATION. HOWEVER...AS STORMS INCREASE IN COVERAGE BY THE LATE AFTERNOON AND EARLY EVENING...THE DOMINANT STORM MODE REMAINS QUESTIONABLE. THE WEAK LARGE-SCALE ASCENT AND LINEARLY ORIENTED CONVERGENCE ZONE MAY HELP STORMS TO ORGANIZE QUICKLY INTO A LINE. IF THIS OCCURS...THE STRONGER CELLS IN THE LINE SHOULD STILL BE CAPABLE OF LARGE HAIL AND ISOLATED WIND DAMAGE. THE LINE SHOULD CONTINUE SEWD MOVING INTO THE IMMEDIATE COASTAL AREAS BY THE EARLY EVENING. FURTHER SOUTH ACROSS SOUTH TX AND THE TX HILL COUNTRY...FORECAST SOUNDINGS SHOW INCREASING VERTICAL SHEAR PROFILES DURING THE DAY AS A MID-LEVEL JET NOSES INTO THE REGION. THIS COMBINED WITH MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND ISOLATED WIND DAMAGE AS STORMS INITIATE IN THE AFTERNOON. DUE TO THE STRONGER VERTICAL SHEAR...THE SUPERCELL POTENTIAL THROUGH THE LATE AFTERNOON AND EVENING APPEARS GREATER THAN AREAS FURTHER NORTH. THIS COULD SUSTAIN THE THREAT FOR LARGE HAIL AND WIND DAMAGE THREAT LONGER INTO THE EVENING. HOWEVER...ANY SEVERE THREAT SHOULD DIMINISH BEFORE MIDNIGHT DUE TO THE RELATIVELY WEAK LARGE-SCALE ASCENT AND DECREASING INSTABILITY. ...TN VALLEY/SRN APPALACHIANS/CAROLINAS... AT UPPER-LEVELS...A BROAD RIDGE OVER THE MS VALLEY WILL DRIFT EWD AND DAMPEN OUT IN WLY FLOW. AT THE SFC...A COLD FRONT WILL MOVE SWD ACROSS THE REGION. SOUTH OF THE BOUNDARY...SFC DEWPOINTS IN THE 60S F SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP BY AFTERNOON. ALTHOUGH LARGE-SCALE ASCENT SHOULD REMAIN RELATIVELY WEAK...STRENGTHING LOW-LEVEL CONVERGENCE ALONG AND AHEAD OF THE FRONTAL BOUNDARY AND SFC HEATING SHOULD ALLOW STORMS TO INITIATE IN TN...NRN AL AND THE SRN APPALACHIAN MTNS DURING THE AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW THE STRONGEST VERTICAL SHEAR PROFILES ACROSS TN AND THE SRN APPALACHIAN MTNS WHERE THE SEVERE THREAT WILL LIKELY BE THE GREATEST. 0-6 KM SHEAR VALUES OF 30 TO 40 KT SHOULD BE SUFFICIENT FOR SUPERCELLS BEFORE A GRADUAL TRANSITION TO LINEAR DEVELOPMENT WHICH IS LIKELY IN THE LATE AFTERNOON. THE STRONGER CELLS IN THE LINE SHOULD BE CAPABLE OF LARGE HAIL AND ISOLATED WIND DAMAGE ESPECIALLY NEAR PEAK HEATING. HOWEVER...THE LINE SHOULD GRADUALLY WEAKEN DURING THE EARLY EVENING AS THE CONVECTION ENCOUNTERS WEAKER VERTICAL SHEAR OVER CNTRL AL AND NCNTRL GA. FURTHER EAST ACROSS THE CAROLINAS...WEAK INSTABILITY SHOULD DEVELOP AHEAD OF A SFC LOW AND FRONTAL BOUNDARY BY AFTERNOON. THIS COMBINED WITH MODERATE VERTICAL SHEAR SHOWN ON FORECAST SOUNDINGS SHOULD BE SUFFICIENT FOR AT LEAST AN ISOLATED SEVERE THREAT. ALTHOUGH SUPERCELLS WILL BE POSSIBLE...QUESTIONS REMAIN CONCERNING INSTABILITY. IF MODERATE INSTABILITY DEVELOPS...A FEW SUPERCELLS WITH LARGE HAIL AND WIND DAMAGE COULD DEVELOP. HOWEVER...ANY SEVERE THREAT SHOULD GRADUALLY DECREASE BY EARLY EVENING AS INSTABILITY WEAKENS AND THE FRONT MOVES SWD ACROSS THE REGION. ..BROYLES.. 04/25/2006  From SwoDy1 at goshenarc.org Tue Apr 25 12:40:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 08:40:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251236 SWODY1 SPC AC 251234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT TUE APR 25 2006 VALID 251300Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM SRN AND ERN TX ACROSS THE LOWER MS VALLEY TO NC.... ...SYNOPSIS... A NRN STREAM TROUGH IS DIGGING SEWD OVER THE GREAT LAKES...AND THE REMNANTS OF A SRN STREAM TROUGH ARE EJECTING EWD FROM THE HIGH PLAINS IN A CONFLUENT FLOW REGIME. A WEAK SURFACE WAVE WILL DEVELOP EWD IN ADVANCE OF THESE MID LEVEL TROUGHS...ALONG A LOW-LEVEL BAROCLINIC ZONE FROM KY TO NC. SW OF THE SURFACE WAVE...THE COLD FRONT WILL MOVE SEWD ACROSS TX/AR/LA. THE SURFACE FRONT...ALONG WITH A RESIDUAL OUTFLOW BOUNDARY FROM A WEAKENING MCS IN AR...WILL FOCUS FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT TODAY INTO EARLY TONIGHT. ...SRN AND ERN TX/LA AREA... THE COLD FRONT IS MOVING SEWD ACROSS NRN AND CENTRAL TX...AND THIS FRONT SHOULD EXTEND FROM SRN AR ACROSS NW LA AND SE/S CENTRAL TX BY MID AFTERNOON. ADDITIONALLY...AN OUTFLOW BOUNDARY FROM ONGOING STORMS IN AR/SE OK WILL MOVE SWD AND HELP FOCUS ADDITIONAL CONVECTIVE DEVELOPMENT ACROSS NE TX AND NRN LA TODAY. SW OF THE OUTFLOW BOUNDARY AND AHEAD OF THE COLD FRONT...DAYTIME HEATING...BOUNDARY LAYER DEWPOINTS OF 68-72 F AND 7-8 C/KM MID LEVEL LAPSE RATES WILL SUPPORT MLCAPE VALUES OF 2500-3000 J/KG. FORECAST SOUNDINGS ACROSS S CENTRAL TX APPEAR SUPPORTIVE OF SUPERCELLS ALONG THE FRONT THIS AFTERNOON ONCE CONVECTIVE INHIBITION WEAKENS...WITH MULTICELLULAR CONVECTION EXPECTED FARTHER NE ACROSS E TX/LA. LARGE HAIL AND A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREATS WITH THESE STORMS THIS AFTERNOON...AND THE SEVERE THREAT SHOULD DIMINISH LATER THIS EVENING. ...ERN AR/NRN MS AND AL/TN AREA... THE CONVECTION AND ASSOCIATED COLD POOL OVER AR...AND A SEPARATE MCV OVER SE MO...MAY PERSIST AND SPREAD EWD/SEWD DURING THE DAY ACROSS NW MS AND WRN TN. INSTABILITY WILL BE SOMEWHAT WEAKER THIS AREA COMPARED TO TX...BUT ISOLATED DAMAGING DOWNBURST WINDS AND MARGINALLY SEVERE HAIL WILL BE POSSIBLE DURING THE DAY AS THE LOW LEVELS DESTABILIZE. THE SEVERE THREAT WITH THIS CONVECTION WILL LIKELY DIMINISH THIS EVENING. ...NC AREA THIS AFTERNOON/EVENING... A REMNANT MCV OVER ERN TN WILL MOVE EWD INVOF OF A QUASI-STATIONARY FRONT ACROSS NC. DAYTIME HEATING WILL PROMOTE THE DEVELOPMENT OF A RELATIVELY DEEP BOUNDARY LAYER AND STEEP LOW-LEVEL LAPSE RATES E OF THE MOUNTAINS AND S OF THE FRONT...ALONG WITH AT LEAST WEAK SURFACE-BASED INSTABILITY. DEEP LAYER WLY PROFILES WITH SUBSTANTIAL SPEED INCREASE WITH HEIGHT ALOFT MAY SUPPORT A FEW MARGINAL SUPERCELL OR BOW TYPE STORMS THIS AFTERNOON INTO THIS EVENING NEAR THE FRONTAL ZONE. ISOLATED DAMAGING GUSTS AND MARGINALLY SEVERE HAIL WILL BE THE MAIN SEVERE THREATS. ..THOMPSON/TAYLOR.. 04/25/2006  From swody1 at goshenarc.org Tue Apr 25 16:24:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 12:24:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251619 SWODY1 SPC AC 251617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CDT TUE APR 25 2006 VALID 251630Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX ACROSS THE LOWER MS AND TN VALLEYS INTO NC... MODERATELY FAST ZONAL FLOW PATTERN HAS DEVELOPED ACROSS MUCH OF THE CENTRAL/EASTERN UNITED STATES TODAY...WITH 30-40 KNOT WESTERLY FLOW ALOFT FROM OK/TX INTO THE CAROLINAS. PRIMARY SURFACE BAROCLINIC ZONE EXTENDS FROM CENTRAL TX INTO SOUTHERN MO...THEN EASTWARD ACROSS KY INTO SOUTHERN VA. WIDESPREAD MOIST AND AT LEAST MARGINALLY UNSTABLE AIR MASS WILL LIKELY YIELD SCATTERED THUNDERSTORMS OVER A LARGE AREA THIS AFTERNOON. ...TX/LA/SRN MS... SURFACE COLD FRONT CONTINUES TO SURGE SOUTHWARD ACROSS CENTRAL TX THIS MORNING...WHILE REMNANT OUTFLOW BOUNDARY SAGS SOUTHWARD INTO NORTHERN LA. MORNING VISIBLE SATELLITE IMAGERY SUGGESTS THAT MODERATE DAYTIME HEATING WILL OCCUR ALONG AND SOUTH OF BOUNDARIES IN REGION OF NEAR 70F SURFACE DEWPOINTS. AFTERNOON MLCAPE VALUES WILL LIKELY EXCEED 2500 J/KG ACROSS THIS REGION. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG BOUNDARIES FROM CENTRAL TX INTO NORTHERN LA DURING THE MID/LATE AFTERNOON. THIS ACTIVITY WILL POSE A THREAT OF LARGE HAIL AND DAMAGING WINDS. INCREASING DEEP LAYER VERTICAL SHEAR PROFILES THROUGH THE DAY MAY ALSO SUPPORT ISOLATED SUPERCELL STRUCTURES CAPABLE OF VERY LARGE HAIL. REFER TO MCD NUMBER 651 FOR SHORT TERM DETAILS OF THIS AREA. ...ERN AR/WRN TN/WRN KY/NRN MS... WIDESPREAD MID/HIGH CLOUDS PERSIST THIS MORNING OVER MUCH OF AR INTO WRN TN/KY AND NORTHERN MS. THESE CLOUDS ARE REMNANTS OF OVERNIGHT MCS WHICH HAS DIMINISHED. RELATIVELY STRONG HEATING WILL BE POSSIBLE ACROSS THIS REGION THIS AFTERNOON...ALLOWING AIR MASS TO DESTABILIZE WITH MLCAPE VALUES UP TO 2000 J/KG EXPECTED. CONSIDERABLE UNCERTAINTY EXISTS REGARDING FOCUS FOR INITIATION. HOWEVER...PARAMETERS SUGGEST A THREAT OF ISOLATED SEVERE STORMS WITH HAIL AND DAMAGING WINDS IN THIS REGION IF CONVECTION CAN DEVELOP. ...CENTRAL/EASTERN KY/TN INTO CENTRAL APPALACHIANS... MCV FROM OVERNIGHT THUNDERSTORMS IS NOW OVER WESTERN KY. THIS FEATURE WILL TRACK EASTWARD ALONG SURFACE BAROCLINIC ZONE...POSSIBLY AIDING THE DEVELOPMENT OF SCATTERED THUNDERSTORMS THIS AFTERNOON. STRONG HEATING IN THIS REGION ALONG WITH SUFFICIENT FLOW ALOFT WILL SUPPORT A RISK OF STRONG TO ISOLATED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. REFER TO MCD NUMBER 650 FOR FURTHER DETAILS. ...VA/NC... STRONG DAYTIME HEATING WILL OCCUR THROUGHOUT THIS REGION TODAY...AS DEWPOINTS REMAIN IN THE 50S. MODEL FORECAST SOUNDINGS SHOW MLCAPE VALUES OF 500-1500 J/KG WITH RELATIVELY STRONG WESTERLY FLOW ALOFT. VERTICAL SHEAR PROFILES SUPPORT A RISK OF ORGANIZED/ISOLATED SEVERE STORMS FROM SOUTHERN VA INTO NC...BUT WEAK CAPE VALUES ARE A MITIGATING FACTOR. DAMAGING WINDS APPEAR TO BE THE MAIN THREAT WITH MORE SUSTAINED CELLS. ..HART/GRAMS.. 04/25/2006  From swody1 at goshenarc.org Tue Apr 25 20:11:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 16:11:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 252007 SWODY1 SPC AC 252005 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CDT TUE APR 25 2006 VALID 252000Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS VALLEY INTO SRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN MO...ERN AR...WRN TN AND WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF ERN TN...ERN KY...WV...VA AND NC... ...LOWER MS VALLEY... CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP THE REMAINDER OF THIS AFTERNOON ALONG AND S OF A CONVECTIVE OUTFLOW BOUNDARY FROM CNTRL AND SRN LA THROUGH PARTS OF SRN MS AND SRN AL. THE ATMOSPHERE IS MODERATELY UNSTABLE IN THIS REGION...BUT MODEST VERTICAL SHEAR PROFILES ARE GENERALLY SUPPORTIVE OF MULTICELL STORMS. ISOLATED DAMAGING WIND GUSTS AND HAIL MAY ACCOMPANY THE STRONGER ACTIVITY THROUGH EARLY EVENING. ...SRN MO...NERN AR...THROUGH WRN TN AND WRN KY... A COLD FRONT EXTENDS FROM THE OH VALLEY SWWD THROUGH SERN MO...AND WRN AR. THE ATMOSPHERE IS RECOVERING IN PRE-FRONTAL WARM SECTOR IN WAKE OF EARLIER CONVECTION WHERE TEMPERATURES ARE RISING THROUGH THE 70S AND DEWPOINTS ARE IN THE LOWER 60S. LATEST OBJECTIVE ANALYSIS SHOWS AROUND 1000 J/KG OF MUCAPE. CONVERGENCE AND BOUNDARY LAYER FLOW ALONG THE LEADING EDGE OF THE FRONT IS RATHER WEAK...AND RECENT STORMS HAVE BEEN INCREASING IN POST FRONTAL REGION WHERE DEEPER LAYER ASCENT IS OCCURRING. STORMS ARE ELEVATED OVER SWRN MO. HOWEVER...A MID LEVEL JET SPREADING EWD THROUGH SRN PERIPHERY OF SHORTWAVE TROUGH OVER KS IS CONTRIBUTING TO EFFECTIVE SHEAR SUFFICIENT FOR STORMS TO TAKE ON SUPERCELL STRUCTURES WITH ISOLATED HAIL THE MAIN THREATS. STORMS MAY INCREASE IN COVERAGE DURING THE AFTERNOON ACROSS SERN MO AND NERN AR AND SPREAD EWD INTO WRN TN AND WRN KY THIS EVENING AS DEEP LAYER ASCENT INCREASES DOWNSTREAM FROM EWD ADVANCING SHORTWAVE TROUGH. A FEW STORMS MAY DEVELOP CLOSER TO THE SURFACE FRONT WHERE THE ATMOSPHERE CONTINUES TO DESTABILIZE. ISOLATED HAIL AND STRONG WIND GUSTS WILL BE THE PRIMARY THREATS. ...S TX... THE CAP CONTINUES TO WEAKEN WITHIN PRE-FRONTAL WARM SECTOR ACROSS S TX WHERE THE ATMOSPHERE HAS BECOME MODERATELY UNSTABLE WITH MLCAPE AROUND 2500 J/KG. STORMS ARE EXPECTED TO DEVELOP IN VICINITY OF THE FRONT WITHIN THE NEXT COUPLE HOURS OR SO AND SUBSEQUENTLY SPREAD SEWD. DEEP LAYER VERTICAL SHEAR FROM 35 TO 40 KT IS SUFFICIENT FOR SOME STORMS TO TAKE ON SUPERCELL STRUCTURES. THE STRONG INSTABILITY...STEEP MID LEVEL LAPSE RATES AND POTENTIAL FOR UPDRAFT ROTATION WILL SUPPORT THE THREAT OF VERY LARGE HAIL. SOME STORMS MAY EVENTUALLY MERGE INTO CLUSTERS WITH AN INCREASING THREAT FOR DAMAGING WIND GUSTS. ...ERN KY THROUGH WV...VA AND THE CAROLINAS... CONVECTION IS EXPECTED TO CONTINUE DEVELOPING DOWNSTREAM FROM A COUPLE OF MID LEVEL VORTICITY MAXIMA MOVING EWD THROUGH THE TN AND OH VALLEYS. THE DOWNSTREAM ATMOSPHERE IS ONLY MARGINALLY UNSTABLE OWING TO LIMITED LOW LEVEL MOISTURE AND MODEST MID LEVEL LAPSE RATES. THE MARGINAL INSTABILITY WILL CONTINUE TO BE THE PRIMARY LIMITING FACTOR. HOWEVER...SURFACE HEATING HAS CONTRIBUTED TO 20-30C TEMPERATURE-DEWPOINTS SPREADS AND STEEP LOW LEVEL LAPSE RATES. PRIMARY THREAT APPEARS TO BE ISOLATED STRONG TO DAMAGING WIND GUSTS WITH CONVECTIVE LINES OR CLUSTERS AS ACTIVITY SPREADS EWD THE REMAINDER OF THIS AFTERNOON AND EVENING. ..DIAL.. 04/25/2006  From swody1 at goshenarc.org Wed Apr 26 01:01:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 21:01:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260057 SWODY1 SPC AC 260056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT TUE APR 25 2006 VALID 260100Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GULF COASTAL AREAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NC...VA AND FAR WRN TN... ...TX COASTAL PLAINS... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SHORTWAVE TROUGH OVER SOUTH TX WHERE AN MCS IS DEVELOPING ATTM. THE SHORTWAVE TROUGH IS ASSOCIATED WITH THE NOSE OF A SUBTROPICAL MID-LEVEL JET PUNCHING INTO THE REGION FROM THE WEST SOUTHWEST. THIS IS CREATING STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH MODERATE TO STRONG INSTABILITY WILL CONTINUE TO BE FAVORABLE FOR SUPERCELLS. THE LATEST CRP SOUNDING SHOWS MLCAPE VALUES AROUND 3500 J/KG WITH MID-LEVEL LAPSE RATES EXCEEDING 7.5 C/KM SUGGESTING A POTENTIAL FOR VERY LARGE HAIL WILL CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH SUPERCELLS MAY PERSIST THROUGH MUCH OF THE EVENING...A GRADUAL TRANSITION TOWARD A LINEAR CONVECTIVE STRUCTURE MAY OCCUR. THE STRONGER SUPERCELLS MAY ALSO HAVE AN ISOLATED TORNADO/WIND DAMAGE THREAT. AS STORMS MERGE...THE WIND DAMAGE THREAT MAY BECOME LOCALLY ENHANCED WITH BOW ECHOES THAT DEVELOP. BY LATE THIS EVENING...THE SEVERE THREAT WITH THE MCS SHOULD BEGIN TO DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY DECREASES. ...MID-MS VALLEY... WATER VAPOR IMAGERY CURRENTLY SHOWS WLY FLOW ALOFT WITH A DRY SLOT MOVING ACROSS WRN MO AND NRN AR. A COMPLEX OF STORMS IS ONGOING IN NERN AR AND WRN TN NEAR A COLD FRONT AND INVERTED SFC TROUGH. A SMALL POCKET OF MODERATE INSTABILITY EXISTS JUST SOUTH OF THE FRONT WHERE SFC DEWPOINTS ARE IN THE LOWER TO MID 60S F. REGIONAL OOZ SOUNDINGS SHOW STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH THE INSTABILITY WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. A WIND DAMAGE THREAT MAY ALSO EXIST ESPECIALLY ACROSS WRN TN WHERE LOW-LEVEL LAPSE RATES ARE A BIT STEEPER THAN AREA FURTHER WEST. THE SMALL CLUSTER OF STORMS MAY PERSIST THROUGH LATE EVENING...BUT THE SEVERE THREAT SHOULD GRADUALLY DECREASE AS INSTABILITY DIMINISHES ACROSS THE REGION. ...SRN VA/NC AND FAR WRN TX... STRONG WLY MID-LEVEL FLOW WAS IN PLACE ACROSS THE CAROLINAS WITH A COLD FRONT MOVING SWD ACROSS THE CNTRL APPALACHIAN MTNS. AHEAD OF THE FRONT...SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS ERN SC...CNTRL NC INTO SRN VA WITH SFC DEWPOINTS IN THE 60 TO 65 F RANGE. THIS IS RESULTING IN A POCKET OF MODERATE INSTABILITY WHICH COMBINED WITH THE STRONG VERTICAL SHEAR SHOWN ON THE GSO 00Z SOUNDING WILL BE SUFFICIENT FOR SEVERE STORMS. LAPSE RATES ARE STEEP ESPECIALLY AT LOW-LEVELS AND THIS WILL BE FAVORABLE FOR ISOLATED WIND DAMAGE AND HAIL WITH THE STRONGER CELLS. ..BROYLES.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 05:49:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 01:49:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260545 SWODY1 SPC AC 260543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT WED APR 26 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN SC...GA...SRN AL AND NRN FL... ...GULF COAST STATES... AT UPPER LEVELS...A TROUGH WILL DRIFT ESEWD INTO THE MS VALLEY AND OH VALLEYS TODAY AS A SFC LOW AND COLD FRONT MOVE EWD ACROSS MS...AL AND GA. MODEL FORECASTS ARE IN GENERAL AGREEMENT WITH A LARGE MCS ONGOING ACROSS SRN LA...SRN MS AND POSSIBLY AS FAR EAST AS SRN AL AT THE BEGINNING OF THE PERIOD. SFC HEATING SHOULD BE MAXIMIZED BY AFTERNOON EAST OF THE MCS ACROSS THE FL PANHANDLE AND SRN GA WITH POCKETS OF MODERATE INSTABILITY DEVELOPING BY MIDDAY. THIS MAY HELP TO REINTENSIFY STORMS ASSOCIATED WITH THE MCS IN THE EARLY AFTERNOON. OTHER STORMS SHOULD ALSO DEVELOP AHEAD OF THE MCS IN GA/NRN FL AND FURTHER NORTHWEST NEAR THE SFC BOUNDARY IN CNTRL AL. FORECAST SOUNDINGS ACROSS THE REGION TODAY GRADUALLY INCREASE VERTICAL SHEAR PROFILES AS A 50 KT MID-LEVEL JET ASSOCIATED WITH THE TROUGH SHIFTS SEWD. WITH MID 60S F SFC DEWPOINTS IN THE WARM SECTOR...THE STRENGTHENING SHEAR SHOULD MAKE ISOLATED SEVERE STORMS INCREASINGLY LIKELY IN THE AFTERNOON. IF MODERATE INSTABILITY DEVELOPS IN THE WARM SECTOR...SUPERCELLS WILL BE POSSIBLE BUT MULTICELL STORMS SHOULD ALSO HAVE SEVERE POTENTIAL. ALTHOUGH LAPSE RATES ARE NOT FORECAST TO BE THAT STEEP...THE UNDIRECTIONAL SHEAR PROFILES MAY SUPPORT ISOLATED WIND DAMAGE. HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER STORMS ESPECIALLY IN AREAS WITH LOCALLY MAXIMIZED INSTABILITY. THE SEVERE THREAT SHOULD BE CONCENTRATED NEAR OR JUST AFTER PEAK HEATING IN THE LATE AFTERNOON AND EARLY EVENING. ...CALIFORNIA... AN UPPER LOW JUST OFF THE SRN CA COAST IS FORECAST TO MOVE SEWD TODAY. NORTH OF THE UPPER-LOW...ELY FLOW WILL BE IN PLACE ACROSS THE SACRAMENTO VALLEY WHICH WILL ALLOW STORMS THAT INITIATE IN THE SIERRAS TO DRIFT WWD INTO THE VALLEY AREAS DURING THE AFTERNOON. AFTERNOON FORECAST SOUNDINGS ACROSS THE SACRAMENTO VALLEY SHOW SUFFICIENT INSTABILITY/SHEAR PROFILES AND STEEP ENOUGH LAPSE RATES FOR MARGINALLY SEVERE HAIL STORMS. DUE TO WIDESPREAD LARGE-SCALE ASCENT ON THE NORTH SIDE OF THE UPPER LOW...THE HAIL THREAT MAY PERSIST INTO THE EARLY EVENING BEFORE GRADUALLY DIMINISHING DUE TO THE WEAKENING INSTABILITY. ..BROYLES/CROSBIE.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 12:58:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 08:58:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261254 SWODY1 SPC AC 261253 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 AM CDT WED APR 26 2006 VALID 261300Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM SE MS/LA TO THE SC/GA/NE FL COAST.... ...SYNOPSIS... THE MID LEVEL SHORTWAVE TROUGH OVER MO THIS MORNING WILL MOVE SEWD AROUND THE SRN PERIPHERY OF A BROAD TROUGH OVER THE NE STATES...AND WILL REACH THE SRN APPALACHIANS BY LATE TONIGHT. AT THE SURFACE...A WEAK WAVE INVOF N GA WILL DEVELOP EWD ALONG A BAROCLINIC ZONE TO SC LATER TODAY...AS A COLD FRONT MOVES SEWD ACROSS THE GULF COAST STATES. ...SE STATES TODAY... THE SURFACE PATTERN IN THE WARM SECTOR HAS BEEN COMPLICATED BY MULTIPLE CONVECTIVE OUTFLOWS THE PAST DAY OR SO...WITH CONVECTION ONGOING ACROSS NRN AL AND FROM SRN LA TO SW AL. IT APPEARS THAT THE MORE UNDISTURBED AIR MASS WILL RESIDE ACROSS THE FL PANHANDLE TO SC IN ADVANCE OF THE MORNING STORMS...AND IN A BAND FROM ERN MS/CENTRAL AL AND CENTRAL/N GA THAT HAS NOT BEEN OVERTURNED BY PREVIOUS CONVECTION. GIVEN THE ONGOING STORMS AND THE POSSIBILITY FOR ADDITIONAL DEVELOPMENT ALONG THE COLD FRONT AND ALONG THE PATH OF THE SURFACE WAVE...SEVERAL THUNDERSTORM CLUSTERS CAN BE EXPECTED ACROSS THE SLIGHT RISK AREA THROUGH LATE EVENING. RESIDUAL CLOUDINESS FROM OVERNIGHT CONVECTION MAY LIMIT SURFACE HEATING SOME IN THE WARM SECTOR. ALSO...MID LEVEL LAPSE RATES WILL LIKELY DIMINISH WITH TIME AS A RESULT OF CONVECTION AND TRAJECTORIES NO LONGER EMANATING FROM THE EML SOURCE REGION TO THE W. STILL...BOUNDARY LAYER DEWPOINTS OF 65-70 F AND DAYTIME TEMPERATURES OF 75-85 F WILL SUPPORT MLCAPE VALUES IN THE RANGE OF 500-1000 J/KG. WIND PROFILES IN THE WARM SECTOR SHOULD BE LARGELY UNIDIRECTIONAL WITH SOME SPEED INCREASE ALOFT...WHICH IN COMBINATION WITH THE WEAK-MODERATE INSTABILITY MAY SUPPORT A FEW STORMS WITH LARGE HAIL AND DAMAGING WINDS. ..THOMPSON/CROSBIE.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 16:20:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 12:20:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261615 SWODY1 SPC AC 261613 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CDT WED APR 26 2006 VALID 261630Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE SOUTHEAST STATES... BROAD UPPER TROUGH OVER THE MID MS VALLEY WILL TRACK EASTWARD TODAY INTO KY/TN. A LARGE AREA OF STRONGER MID LEVEL WESTERLY FLOW /40-50 KNOTS AT 500MB/ IS PRESENT TO THE SOUTHEAST OF THE TROUGH...AND WILL OVERSPREAD MUCH OF THE SOUTHEASTERN U.S. THIS AFTERNOON AND EVENING. SOUTHWESTERLY LOW LEVEL WINDS ARE ALSO FORECAST TO STRENGTHEN ACROSS GA/SC BY 00Z AS WEAK CYCLOGENESIS OCCURS OVER SC. THESE TRENDS WILL RESULT IN INCREASINGLY FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/SEVERE STORMS ACROSS MUCH OF AL/GA/SC AND NORTH FL. ...SC... MORNING SURFACE ANALYSIS SHOWS WEAK LOW OVER UPSTATE SC...WITH FRONT EXTENDING EASTWARD TO SOUTH OF MYR. STRONG DAYTIME HEATING IS OCCURRING ALONG AND SOUTH OF BOUNDARY WITH TEMPERATURES EXPECTED TO RISE INTO THE 80S. AFTERNOON SBCAPE VALUES OVER 2500 J/KG...ALONG WITH CONVERGENCE ALONG FRONT...WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS. DESPITE RATHER WEAK LOW LEVEL FLOW IN THIS REGION...DEEP LAYER SHEAR WILL SUPPORT ISOLATED SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. BRIEF TORNADOES COULD ALSO OCCUR NEAR BOUNDARIES. ...ERN GA/NRN FL... MORE ISOLATED THUNDERSTORM DEVELOPMENT IS EXPECTED SOUTHWARD TO EASTERN GA AND POSSIBLY NORTHERN FL AS CONVECTIVE TEMPERATURE IS REACHED /LOWER 80S/ AND REMNANT OUTFLOW BOUNDARIES MOVE INTO REGION. STRONGER CELLS IN THIS REGION WILL POSE A THREAT OF DAMAGING WINDS AND HAIL. ...AL... PRIMARY SURFACE COLD FRONT EXTENDS FROM NORTHEAST MS INTO EASTERN TN. LOW LEVEL MOISTURE REMAINS IN PLACE AHEAD OF FRONT WITH DEWPOINTS IN THE 60S ACROSS ALL OF AL. IF BREAKS IN THE CLOUDS ALLOW AFTERNOON HEATING...SUFFICIENT DESTABILIZATION COULD OCCUR TO SUPPORT A RISK OF ISOLATED SEVERE STORMS. CURRENT VISIBLE SATELLITE IMAGERY SUGGESTS THIS THREAT IS RATHER LOW. ..HART/GRAMS.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 19:47:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 15:47:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261944 SWODY1 SPC AC 261942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0242 PM CDT WED APR 26 2006 VALID 262000Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE SERN U.S.... ...SERN STATES... EARLY THIS AFTERNOON A BACK DOOR COLD FRONT HAS SETTLED SWD ACROSS CNTRL NC. FARTHER W A COLD FRONT EXTENDS FROM SERN TN SWWD THROUGH NWRN AL AND INTO SERN MS. NUMEROUS STORMS ARE DEVELOPING IN THE WEAKLY CAPPED WARM SECTOR BETWEEN THESE TWO BOUNDARIES FROM AL EWD THROUGH GA AND SC AS WELL AS NRN FL. RECENT OBJECTIVE ANALYSIS DATA SHOW THE ATMOSPHERE IS MOST UNSTABLE FROM ERN GA INTO SC WHERE STRONGER SURFACE HEATING HAS CONTRIBUTED TO MLCAPE AROUND 2000 J/KG. STRONGEST STORMS CONTINUE DEVELOPING IN VICINITY OF THE BACK DOOR FRONT ACROSS SC. VWP DATA SHOW RELATIVELY WEAK WLY FLOW THROUGH THE LOWEST 2 KM IN SC. HOWEVER...PRESENCE OF 50 KT MID LEVEL FLOW ON SERN PERIPHERY OF SHORTWAVE TROUGH MOVING EWD THROUGH THE TN VALLEY IS RESULTING IN DEEP LAYER SHEAR ON THE ORDER OF 45 KT...SUFFICIENT FOR SUPERCELL STRUCTURES. PRIMARY THREAT IS VERY LARGE HAIL AND DAMAGING WIND GUSTS WITH THESE STORMS. A BRIEF TORNADO OR TWO IS POSSIBLE...MAINLY IN NARROW ZONE ACROSS CNTRL SC AS STORMS CROSS THE BOUNDARY BEFORE BECOMING ELEVATED AND WEAKENING AS THEY MOVE DEEPER INTO THE COOL SIDE OF THE FRONT. ELSEWHERE...AN MCS CONTINUES TO ADVANCE EWD THROUGH SRN GA WHERE THE WLY LOW LEVEL JET HAS BEEN STRENGTHENING DURING THE PAST COUPLE HOURS. DAMAGING WIND AND HAIL MAY ACCOMPANY THIS ACTIVITY AS IT CONTINUES EWD THROUGH SRN GA...REACHING SRN SC LATER THIS AFTERNOON. OTHERWISE...SEVERE THREAT FARTHER W ACROSS THE REMAINDER OF AL...NRN GA AND SERN MS AHEAD OF THE FRONT APPEARS MORE MARGINAL GIVEN MUCH OF THIS AREA HAS BEEN SOMEWHAT STABILIZED FROM EARLIER CONVECTION. ..DIAL.. 04/26/2006  From SwoDy1 at goshenarc.org Fri Apr 28 01:50:26 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 27 Apr 2006 21:50:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280148 SWODY1 SPC AC 280146 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0846 PM CDT THU APR 27 2006 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED FOR POINTS FILE ...CNTRL/SRN PLAINS... RESIDUAL LARGE SCALE RIDGING AND HIGH CLOUDS MAINTAINED A FAIRLY UNFAVORABLE ENVIRONMENT FOR TSTMS OVER THE MOUNTAINS OF SWRN TX DURING THE AFTN. 18...21 AND 00Z MIDLAND SOUNDINGS ALSO SHOWED SIGNIFICANT INHIBITION ON THE PLAINS TO SUPPRESS TSTMS. THOUGH THE LARGE SCALE IS EXPECTED TO BECOME MORE CYCLONIC ALOFT THROUGH THE NIGHT...IT IS NOT CLEAR WHETHER WIDESPREAD ORGANIZED SEVERE STORMS WILL DEVELOP. SLIGHTLY HIGHER PROBABILITIES FOR TSTMS WILL EXIST ACROSS THE BIG BEND REGION AND INTO WRN PARTS OF SCNTRL TX AS ELEVATED BANDS OF STORMS BECOME BETTER DEFINED WITHIN THE WARM CONVEYOR BELT. HERE...ISOLD HAIL MAY OCCUR GIVEN STEEP LAPSE RATES. FARTHER N...COMBINATION OF A MORE FAVORABLE DIFFLUENT/DIVERGENT UPPER FLOW REGIME DOWNSTREAM FROM THE DESERT SW UPPER LOW...A STRONGER COMPONENT OF MOISTENING UPSLOPE FLOW AND HEATING CONTRIBUTED TO MORE TSTM COVERAGE THIS AFTN. VERTICAL SHEAR HAS BEEN SUPPORTIVE OF STRONG-SEVERE STORMS/SUPERCELLS OVER MAINLY ECNTRL/NERN NM. THESE STORMS MAY PRODUCE ISOLD LARGE HAIL OR A DAMAGING WIND GUST THROUGH MID-EVENING. THE NERN NM ACTIVITY IS LIKELY TO EXPAND ENEWD ACROSS THE CNTRL PLAINS ALONG/N OF THE SEWD MOVING LEE-TROUGH/COLD FRONT OVERNIGHT. STEEP LAPSE RATE ENVIRONMENT AND FAVORABLE VERTICAL SHEAR MAY BE SUFFICIENT FOR STRONG TSTMS WITH PERHAPS ISOLD HAIL/GUSTY WINDS. ..RACY.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 05:54:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 01:54:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280553 SWODY1 SPC AC 280551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT FRI APR 28 2006 VALID 281200Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF WCNTRL/CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SRN PLAINS... ...SYNOPSIS... A HIGHLY AMPLIFIED UPPER FLOW REGIME WILL CONTINUE ON FRI. UPPER LOW NOW MOVING ACROSS THE DESERT SW WILL ACCELERATE EWD THROUGH THE SRN ROCKIES EARLY TODAY AS IT BEGINS TO PHASE WITH A NRN STREAM IMPULSE DROPPING SWD THROUGH THE PLAINS. THE SRN DISTURBANCE AND ATTENDANT 60-METER/12-HR HEIGHT FALLS WILL SPREAD EWD ACROSS THE SRN PLAINS FRI AFTN/NIGHT. AT THE SFC...THE WARM FRONT SITUATED ACROSS SRN TX WILL REDEVELOP NWD THROUGH WRN/CNTRL TX BY FRI AFTN. A LEE-TROUGH/DRYLINE WILL BECOME ESTABLISHED FROM THE SRN TX PNHDL SWD INTO SWRN TX BY FRI MID-AFTN. MEANWHILE...A COLD FRONT...ASSOCIATED WITH THE NRN STREAM TROUGH...WILL MOVE SEWD ACROSS THE ERN PLAINS AND SWD THROUGH THE TX PNHDL THROUGH FRI NIGHT. ...SRN PLAINS... THERE WILL LIKELY BE WIDESPREAD CLOUDS/CONVECTION ONGOING EARLY FRI MORNING ACROSS PARTS OF OK AND CNTRL/ERN TX...ALONG THE NOSE OF A LLJ. THIS WILL ACT TO REINFORCE THE NW-SE ORIENTED FRONT ACROSS CNTRL TX THROUGH FRI EVENING. LATEST MODELS SUGGEST THAT THE WARM CONVEYOR WILL BEGIN TO SHIFT EWD DURING THE AFTN. THIS SHOULD ALLOW STRONG HEATING TO OCCUR ACROSS SWRN/WCNTRL TX NWD INTO THE ERN TX PNHDL/SWRN OK FRI AFTN. CONCURRENTLY...LOW-LEVEL MOISTURE...NOW IMPROVING ACROSS DEEP S TX NWWD INTO THE TRANSPECOS REGION...WILL ADVECT NWWD AS THE SELY FLOW ACCELERATES AHEAD OF THE APPROACHING UPPER LOW. BY PEAK HEATING...60S BOUNDARY LAYER DEW POINTS SHOULD EXIST ALONG/E OF THE DRYLINE AND SOUTH OF THE WARM FRONT. STEEPENING MID-LEVEL LAPSE RATES...OWING TO LARGE SCALE ASCENT/MOISTENING AND MID-LEVEL COLD ADVECTION...SPREADING EWD ATOP THE LOW-LEVEL THETA-E AXIS WILL ENCOURAGE TSTMS TO INITIATE ALONG THE DRYLINE/HIGHER TERRAIN BY MID-AFTN FROM THE ERN TX PNHDL SWD INTO SWRN TX. GIVEN 70+ KTS OF VERTICAL SHEAR AND MAGNITUDE OF INSTABILITY...TSTMS WILL LIKELY GROW INTO SUPERCELLS WITH VERY LARGE HAIL...PARTICULARLY OVER WCNTRL/CNTRL TX SWD TOWARD THE RIO GRANDE. BACKED LOW-LEVEL FLOW VCNTY OF THE RETREATING WARM FRONT WILL ALSO BE FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THE INFLUX OF A MOIST BOUNDARY LAYER. THE MID-LEVEL FLOW WILL GRADUALLY BACK DURING THE EVENING AS THE UPPER LOW MOVES EWD. THUS...TSTMS WILL TEND TO EVOLVE INTO A LINEAR MCS AFTER DARK...THEN MOVE EWD ACROSS OK...CNTRL/ERN TX OVERNIGHT WITH ATTENDANT HAIL/HIGH WINDS. STRONGER ACTIVITY WILL LIKELY FAVOR THE SRN EDGE OF THE MCS ACROSS SCNTRL TX WHERE THE BETTER QUALITY MOISTURE/INSTABILITY WILL RESIDE S OF THE WARM FRONT. ...NRN PLAINS... STEEP LOW/MID-LEVEL LAPSE RATES BENEATH THE WEAKENING NRN STREAM IMPULSE WILL PERSIST ACROSS THE NRN PLAINS FRI. A NARROW AXIS OF BOUNDARY LAYER DEW POINTS AOA 45 DEG F BENEATH H5 TEMPERATURES AROUND MINUS 20 DEG C WILL BE FAVORABLE FOR SCT STRONG TSTMS. THOUGH THE VERTICAL SHEAR WILL BE WEAK...MAGNITUDE OF THE LAPSE RATES WILL PROBABLY FOSTER LARGE HAIL PRODUCTION WITH ISOLD STRONGER UPDRAFTS. ..RACY/BRIGHT/CROSBIE.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 12:43:24 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 08:43:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281241 SWODY1 SPC AC 281240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT FRI APR 28 2006 VALID 281300Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF W CNTRL AND CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE PART OF THE SRN PLNS... ...SYNOPSIS... THE MAIN BELT OF THE WLYS WILL REMAIN WELL TO THE N ACROSS CNTRL CANADA THIS PERIOD. PATTERN WILL...NEVERTHELESS...BECOME MORE AMPLIFIED OVER THE LWR 48 AS SE AZ UPR LOW CONTINUES E AND PHASES WITH NRN STREAM TROUGH NOW OVER THE NRN HI PLNS. THE COMBINED SYSTEMS SHOULD REACH THE CNTRL PLNS BY 12Z SATURDAY AS ASSOCIATED 60-90M HEIGHT FALL CENTER ADVANCES FROM W TX THIS AFTERNOON...AND INTO CNTRL PARTS OF OK/KS EARLY SATURDAY. AT LWR LEVELS..COLD FRONT NOW IN THE CNTRL HI PLNS EXPECTED TO CONTINUE SURGING S INTO NE NM AND THE WRN/NRN OK/TX PANHANDLES THROUGH THE AFTERNOON...BEFORE TURNING MORE SE TOWARD THE I-35 CORRIDOR TONIGHT/EARLY SATURDAY. S OF THIS FRONT...DRY LINE/ PACIFIC COLD FRONT NOW IN NM SHOULD MIX E INTO W TX DURING THE AFTERNOON. AHEAD OF THIS FEATURE...DIFFUSE WARM FRONT NOW EXTENDING FROM NEAR LBB THROUGH SJT TO VCT SHOULD REDEVELOP NE INTO CNTRL TX. ...SRN PLNS... STRENGTHENING WARM ADVECTION/UPR LEVEL DIVERGENCE AHEAD OF AZ UPR LOW EXPECTED TO RESULT IN INCREASING COVERAGE OF ELEVATED TSTMS THROUGH THE DAY FROM MUCH OF KS/SRN NEB S/SE INTO CNTRL/ERN OK AND NE TX. THIS ACTIVITY SHOULD LIMIT NWD/EWD ADVANCE OF BOUNDARY LAYER MOISTURE RETURN ACROSS MUCH OF OK AND NE TX. GIVEN EXISTING LOW LEVEL MOISTURE AXIS NOW EXTENDING FROM S CNTRL TX NWWD TO NEAR MAF/LBB...AND CURRENT SATELLITE TRENDS SUGGESTING THAT MID/UPR LEVEL CLOUDS WILL CLEAR SLOWLY SE ACROSS THE REGION THROUGH THE DAY...EXPECT THAT SURFACE-BASED INSTABILITY AXIS BY MID AFTERNOON WILL EXTEND FROM THE ERN TX PANHANDLE/FAR WRN OK SWD IN A WIDENING BAND ACROSS W CNTRL TX INTO THE TX HILL COUNTRY/TX BIG BEND. MUCAPE LIKELY WILL RANGE FROM 1000-1500 J/KG IN THE NORTH TO LOCALLY ABOVE 2000 J/KG NEAR THE RIO GRANDE...WHERE DEWPOINTS SHOULD REMAIN IN THE MID TO UPR 60S. CONVERGENCE AND HEATING SHOULD INITIATE STORMS ALONG EWD-MOVING DRY LINE/PACIFIC COLD FRONT...AND ALONG SWD-MOVING COLD FRONT...FROM THE SRN/ERN PANHANDLE REGION S ACROSS THE LOW ROLLING PLAINS/WRN HILL COUNTRY BY MID TO LATE AFTERNOON. ONE OR TWO STORMS MAY ALSO FORM IN ZONE OF CONVERGENT UPSLOPE FLOW JUST W OF THE LWR PECOS. PRESENCE OF NRN STREAM IMPULSE WILL KEEP A BRANCH OF THE LLJ AIMED N TOWARD THE LWR MO VLY TODAY. THIS WILL TEND TO WEAKEN AND VEER LOW LVL WIND PROFILES SOMEWHAT OVER THE SRN PLNS. NEVERTHELESS... GIVEN STRENGTHENING MID/UPR LEVEL WINDS DOWNSTREAM FROM AZ SYSTEM /500 MB SWLY FLOW EXPECTED TO BE AOA 70 KTS BY MID AFTERNOON ACROSS CNTRL-SCNTRL TX/...AND DEGREE OF INSTABILITY/MOISTURE INFLOW...SETUP LIKELY WILL FOSTER SUPERCELLS WITH VERY LARGE HAIL/ HIGH WIND AND POSSIBLY A FEW TORNADOES...ESPECIALLY FROM E OF LBB SE INTO THE EDWARDS PLATEAU/BIG BEND. TORNADO POTENTIAL SHOULD BE GREATEST INVOF ANY WARM FRONTAL SEGMENTS...WHERE SELY LOW LEVEL FLOW MAY LOCALLY ENHANCE SRH. AS UPR SYSTEM CONTINUES EWD...STRENGTH/LINEAR NATURE OF LARGE SCALE FORCING...AND EXISTING WIND PROFILES...SUGGEST FAIRLY RAPID EVOLUTION TOWARD BROKEN LINE SEGMENTS WITH EMBEDDED SUPERCELLS. THIS ACTIVITY SHOULD FURTHER CONSOLIDATE INTO ONE OR TWO FAIRLY EXTENSIVE SQUALL LINES...WITH THE SYSTEMS MOVING GENERALLY E ACROSS THE REMAINDER OF CNTRL TX AND S CNTRL OK LATE THIS EVENING. INSTABILITY CONSIDERATIONS...AND EXPECTED STRENGTHENING OF LOW LEVEL WIND FIELD AS UPR SYSTEMS FINALLY PHASE OVER KS...SUGGEST THAT THE MCSS WILL CONTINUE TO POSE A THREAT FOR DAMAGING WIND/HAIL AND PERHAPS ISOLATED TORNADOES AS THEY CROSS THE TX CSTL PLN/NE TX BETWEEN 09 AND 12Z SATURDAY. ...NRN PLAINS... STEEP LOW/MID-LEVEL LAPSE RATE PLUME WILL PERSIST BENEATH WEAKENING NRN STREAM IMPULSE OVER THE NRN PLAINS TODAY. GIVEN SURFACE HEATING...NARROW AXIS OF BOUNDARY LAYER DEW POINTS AOA 45 DEG F BENEATH 500 MB TEMPERATURES AROUND MINUS 20 DEG C SHOULD SUPPORT SCTD STRONG TSTMS. VERTICAL SHEAR WILL BE WEAK...BUT SUFFICIENT INSTABILITY MAY DEVELOP TO FOSTER HAIL IN THE STRONGER UPDRAFTS. ..CORFIDI/CROSBIE.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 16:46:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 12:46:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281645 SWODY1 SPC AC 281643 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 AM CDT FRI APR 28 2006 VALID 281630Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF WRN...SWRN AND W CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE SRN PLAINS... ...SRN PLAINS... A COLD FRONT EXTENDS FROM W CNTRL KS SWWD THROUGH THE OK AND TX PANHANDLES. A DRY LINE/PACIFIC FRONT EXTENDS FROM SWRN TX NEAR FORT STOCKTON NWD INTO THE WRN TX PANHANDLE WHERE IT INTERSECTS THE SEWD ADVANCING COLD FRONT. FARTHER S...A WARM FRONT EXTENDS ACROSS SRN TX FROM NEAR HOUSTON WWD INTO THE RIO GRANDE AREA. THE WARM FRONT SEPARATES RICH GULF MOISTURE WITH DEWPOINTS NEAR 70 FROM THE PARTIALLY MODIFIED GULF AIR WITH DEWPOINTS IN THE LOW TO MID 60S. WIDESPREAD CLOUDS PERSIST IN THE WARM SECTOR E OF THE DRYLINE. HOWEVER...CLOUDS ARE CLEARING OUT ACROSS W TX IN PROXIMITY TO MID/UPPER LEVEL DRY SLOT. THE ATMOSPHERE SHOULD CONTINUE TO DESTABILIZE FROM NEAR THE BIG BEND NWD INTO NWRN TX ALONG THE MOIST AXIS WITH MLCAPE FROM 1500 TO 2000 J/KG THIS AFTERNOON. INCREASING BOUNDARY LAYER CONVERGENCE AND WEAKENING CAP SHOULD CONTRIBUTE TO THUNDERSTORM INITIATION ACROSS W TX THIS AFTERNOON. ADDITIONAL STORMS WILL LIKELY DEVELOP ALONG SEWD ADVANCING FRONT FROM THE SRN TX PANHANDLE INTO SWRN OK. A MID LEVEL JET WILL ROTATE NEWD THROUGH WRN TX ALONG THE SERN PERIPHERY OF THE NM CUTOFF LOW AND WILL CONTRITE TO INCREASING LARGE SCALE ASCENT. THIS FEATURE WILL ALSO MAINTAIN VERTICAL SHEAR PROFILES SUPPORTIVE OF SUPERCELL STRUCTURES. VERY LARGE HAIL AND A FEW TORNADOES MAY ACCOMPANY THIS ACTIVITY AS IT SPREAD EWD THROUGH WRN TX AND INTO W CNTRL TX THIS AFTERNOON. ACTIVITY MAY EVENTUALLY EVOLVE INTO AN MCS AS IT DEVELOPS EWD OVERNIGHT WITH A CONTINUED THREAT FOR LARGE HAIL AND DAMAGING WIND. ISOLATED TORNADOES ALSO REMAIN POSSIBLE...ESPECIALLY WITH ANY DISCRETE ACTIVITY ON SRN END OF MCS. A STRONG LOW LEVEL JET WILL PERSIST ACROSS CNTRL TX AND MAINTAIN ISENTROPIC LIFT ALONG AND N OF E-W BOUNDARY ACROSS S CNTRL TX. ELEVATED STORMS ARE CURRENTLY DEVELOPING FROM S CNTRL THROUGH N TX WITHIN THIS WARM ADVECTION REGIME. AS LOW LEVEL DEWPOINTS CONTINUE TO DEVELOP NWD AND AS THE BOUNDARY LAYER WARMS...THERE IS POTENTIAL FOR SOME OF THESE STORMS TO BECOME CLOSER TO SURFACE BASED. LOW LEVEL HODOGRAPHS ARE ENHANCED BY VEERING BOUNDARY LAYER FLOW IN VICINITY OF THE WARM FRONT ACROSS S CNTRL TX...AND WOULD ENHANCE THE THREAT FOR ISOLATED TORNADOES IF STORMS MANAGE TO BECOME ROOTED NEAR THE SURFACE. FARTHER N ACROSS OK AND KS...STORMS WILL MOST LIKELY REMAIN ELEVATED GIVEN POTENTIAL FOR MORE WIDESPREAD CONVECTION FARTHER S WHICH SHOULD LIMIT DEGREE OF NWD MOISTURE RETURN AND SURFACE BASED DESTABILIZATION. AT THIS TIME...PRIMARY THREAT APPEARS TO BE LARGE HAIL. ...NRN PLAINS... STEEP MID LEVEL LAPSE RATES WILL SUPPORT A THREAT OF HAIL AS THE ATMOSPHERE DESTABILIZES AND STORMS DEVELOP IN VICINITY OF UPPER LOW THIS AFTERNOON. ..DIAL.. 04/28/2006  From SwoDy1 at goshenarc.org Sat Apr 29 01:04:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 21:04:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290102 SWODY1 SPC AC 290100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT FRI APR 28 2006 VALID 290100Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS CNTRL TX AND SMALL PART OF SWRN OK... ...THERE IS A SLGT RISK OF SVR TSTMS SRN PLAINS... ...SRN PLAINS... EXTENSIVE AREA OF CONVECTION ONGOING OVER MUCH OF THE CENTRAL AND SOUTHERN PLAINS AS UPPER SYSTEM OVER SWRN NM ADVANCES INTO THE CNTRL CONUS. COLD FRONT HAS REACHED INTO WRN OK AND EXTENDS SWD THROUGH THE PANHANDLE OF TX...WITH THE DRYLINE EXTENDING SWD FROM SURFACE LOW INTO SWRN TX. AHEAD OF DRYLINE/SURFACE LOW A MODERATELY UNSTABLE WARM SECTOR /SBCAPE AOB 2500 J/KG/ IS IN PLACE THROUGHOUT CNTRL AND SRN TX. MID LEVEL JET OF 70 KTS IS ENHANCING THE VERTICAL SHEAR IN THE CENTRAL AND SRN PLAINS. 00 UTC SOUNDINGS SHOW IMPRESSIVE LOW/DEEP LAYER SHEAR...PARTICULARLY SOUTH OF THE RED RIVER WHERE SURFACE TO 6 KM AGL SHEAR EXCEEDS 60 TO 70 KTS AND 0-1 KM SRH IS AOB 300 M2/S2. AS STRONG FORCING CONTINUES TO ADVANCE EWD INTO THE PLAINS...EXPECT SURFACE BASED SUPERCELLS TO EVOLVE INTO MIXED LINEAR/DISCRETE MODES WITH CONVECTION CONTINUING THROUGH THE NIGHT. OVERNIGHT PRIND THAT FAIRLY EXTENSIVE SQUALL LINE MAY EVOLVE FROM CNTRL/SRN OK TO CNTRL/ERN TX. THE THREAT OF VERY LARGE HAIL AND DAMAGING WINDS WILL PERSIST...WITH THE GREATEST TORNADO THREAT ALONG AND SOUTH OF THE RED RIVER WHERE MAXIMUM INSTABILITY AND LOW LEVEL MOISTURE RESIDE. FARTHER NORTH ELEVATED CONVECTION WITH THE POTENTIAL FOR EMBEDDED SUPERCELLS WILL EXTEND NWD TO THE KS BORDER. BROAD AREA OF LARGE SCALE ASCENT WILL CONTINUE TO ENHANCE LLJ...SUPPORTING WIDESPREAD CONVECTION...HEAVY PRECIPITATION...AND ISOLATED THREAT OF LARGE HAIL. ..BRIGHT/RACY.. 04/29/2006  From SWODY1 at goshenarc.org Sat Apr 1 00:44:23 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 31 Mar 2006 19:44:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010045 SWODY1 SPC AC 010044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 PM CST FRI MAR 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF MIDDLE TN AND NRN MS/AL... ...OH VALLEY... WELL DEFINED SQUALL LINE HAS FINALLY EMERGED FROM SERN LOWER MI...SWWD INTO SRN IND...AHEAD OF STRONG SHORTWAVE TROUGH. THIS ACTIVITY IS SPREADING EWD AT ROUGHLY 30-35KT AND WILL LIKELY SPREAD ACROSS WRN OH WITH AT LEAST A LARGE HAIL AND DAMAGING WIND THREAT. IN THE ABSENCE OF MEANINGFUL INSTABILITY OVER CENTRAL OH...STRONG CAP AND MEAGER CAPE ON ILN 00Z SOUNDING...LARGE SCALE FORCING WILL AID EWD EXTENT OF CONVECTIVE LINE BUT OVERALL INTENSITY IS EXPECTED TO GRADUALLY DECREASE OVER CNTRL OH LATER THIS EVENING...ESPECIALLY IN THE ABSENCE OF HEATING. ...MIDDLE TN/NCNTRL GULF COAST... BROAD WARM ADVECTION AND STRONG DAYTIME HEATING CONTRIBUTED TO AFTERNOON CONVECTION FROM PORTIONS OF AR...EWD ACROSS MIDDLE TN INTO CNTRL AL. AS DEEP LAYER FLOW GRADUALLY VEERS THIS EVENING...IT APPEARS CONVECTION WILL BECOME CONCENTRATED OVER NRN AL/SRN TN INTO NWRN PORTIONS OF GA. SUFFICIENT VERTICAL SHEAR EXISTS ACROSS THIS REGION FOR MAINTAINING UPDRAFT ORGANIZATION...THUS A FEW STORMS WILL CONTINUE TO PRODUCE HAIL AND LOCALLY DAMAGING WINDS FOR THE NEXT 2-4 HOURS. ...NORTH TX/SRN OK... STALLED FRONTAL ZONE WILL BEGIN TO LIFT NWD ACROSS TX THIS EVENING WITH WEAK WARM ADVECTION EXPECTED TO ENHANCE ASCENT ATOP BOUNDARY LAYER...ESPECIALLY TOWARD THE END OF THE PERIOD. FORECAST SOUNDINGS DISPLAY SUFFICIENT ELEVATED INSTABILITY FOR THUNDERSTORM DEVELOPMENT...THE MAIN IMPEDIMENT FOR ORGANIZED SEVERE THUNDERSTORMS AT THIS TIME APPEARS TO BE THE LACK OF A STRONG LLJ/FORCING. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 05:44:45 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 00:44:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010542 SWODY1 SPC AC 010540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN TX INTO SOUTH CENTRAL KS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM WEST TX INTO SRN NEB...WRN MO...AR...AND NRN LA... ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS FRIDAY... ...CNTRL/SRN PLAINS... UPPER RIDGE WILL BREAK DOWN OVER THE PLAINS EARLY IN THE PERIOD AS A TROUGH EJECTS ACROSS THE SWRN U.S./SRN ROCKIES INTO THE HIGH PLAINS OF WRN KS/TX PANHANDLE BY 00Z/02. LATEST WATER VAPOR IMAGERY DEPICTS A WELL DEFINED UPPER VORT JUST WEST OF SAN...CLEARLY DEFINED AND LIKELY STRONGER THAN MODELS ARE INDICATING. THIS FEATURE WILL PROVE INSTRUMENTAL IN WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT FROM WRN KS INTO THE TX PANHANDLE BY 21Z. LATE EVENING DIAGNOSTIC DATA AND TRENDS SUGGEST BOUNDARY LAYER RECOVERY IS WELL UNDER WAY ACROSS NORTH TX WITH WARM ADVECTION/MOISTENING CONTRIBUTING TO RECENT THUNDERSTORM DEVELOPMENT ACROSS THE TX SOUTH PLAINS...JUST SE OF LBB. IT APPEARS WARM FRONT WILL LIFT INTO OK LATER THIS MORNING AND SLOWLY LOSE ITS IDENTITY. EVEN SO...THUNDERSTORM CLUSTERS MAY BE NOTED WITH THIS RETREAT ACROSS SRN OK...THEN INTO PORTIONS OF AR/LA LATER IN THE MORNING AS BOUNDARY LAYER WARMS/DESTABILIZES. OF MORE CONCERN IS THE EXPECTED RAPID MOISTENING INTO THE TX PANHANDLE/WRN OK INTO WRN KS AHEAD OF UPPER SHORTWAVE. LATEST THINKING IS MODERATE INSTABILITY WILL DEVELOP AS FAR NW AS SWRN KS...WITH SBCAPES IN EXCESS OF 3000 J/KG FARTHER SOUTH INTO THE TX PANHANDLE/WRN OK WHERE MID 60S DEW POINTS WILL BE IN PLACE AHEAD OF THUNDERSTORM INITIATION. IT APPEARS CONVECTION WILL INITIATE PRIOR TO 21Z OVER THE WRN TX PANHANDLE...THEN SPREAD/DEVELOP EWD INTO VERY FAVORABLE ENVIRONMENT FOR SUPERCELLS. FORECAST SOUNDINGS STRONGLY FAVOR TORNADO DEVELOPMENT IF BOUNDARY LAYER MOISTURE DOES INDEED RETURN AS EXPECTED. VERY LARGE HAIL WILL ALSO ACCOMPANY THIS ACTIVITY AS IT SPREADS DOWNSTREAM. BY LATE EVENING AN UPWARD EVOLVING LINEAR MCS WITH EMBEDDED SUPERCELLS AND BOW ECHOES SHOULD SPREAD ACROSS THE REMAINDER OF CNTRL KS/OK TOWARD WRN MO BY THE END OF THE PERIOD. ...LOWER MS VALLEY... RETREATING WARM FRONT ACROSS THE ARKLATEX REGION WILL ENHANCE INSTABILITY/FOCUS FOR LATE MORNING INTO AFTERNOON THUNDERSTORM CLUSTERS ACROSS AR INTO WRN MS. WEAK WARM ADVECTION MAY AID INITIAL THUNDERSTORM DEVELOPMENT...HOWEVER DAYTIME HEATING SHOULD ALSO CONTRIBUTE TO STRONGER THUNDERSTORM ACTIVITY. LARGE HAIL AND DAMAGING DOWNBURSTS SHOULD BE THE PRIMARY FOCUS BEFORE CONVECTION WEAKENS AND LIFTS NEWD INTO THE TN VALLEY LATER IN THE EVENING. ...NERN U.S... A NARROW WEDGE OF MOISTENING/HEATING WILL OCCUR AHEAD OF COLD FRONT ACROSS NY INTO PORTIONS OF SRN NEW ENGLAND LATER THIS MORNING. FORECAST SOUNDINGS ACROSS THE HUDSON VALLEY INTO ERN PA SUGGEST 200-400 J/KG SFC-BASED INSTABILITY WILL DEVELOP PRIOR TO FRONTAL PASSAGE. IT APPEARS A FORCED LINE OF LOW TOPPED THUNDERSTORMS WILL EVOLVE ALONG THE WIND SHIFT THEN SURGE EWD ACROSS THE REMAINDER OF NEW ENGLAND DURING THE AFTERNOON. FORECAST SHEAR AND THE POSSIBILITY FOR WLY MOMENTUM TRANSFER ARE NOT THAT SIGNIFICANT GIVEN THE WEAK INSTABILITY ENVIRONMENT. FORECAST STORM MOTIONS SUGGEST LOCALLY STRONG/DAMAGING WIND GUSTS WITH MORE ORGANIZED CELLS...HOWEVER AT THIS TIME IT APPEARS COVERAGE OF SEVERE WIND GUSTS WILL NOT WARRANT A SLIGHT RISK. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 05:54:48 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 00:54:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010553 SWODY1 SPC AC 010551 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1151 PM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN TX INTO SOUTH CENTRAL KS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM WEST TX INTO SRN NEB...WRN MO...AR...AND NRN LA... CORRECTED FOR WRONG DAY ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS SATURDAY... ...CNTRL/SRN PLAINS... UPPER RIDGE WILL BREAK DOWN OVER THE PLAINS EARLY IN THE PERIOD AS A TROUGH EJECTS ACROSS THE SWRN U.S./SRN ROCKIES INTO THE HIGH PLAINS OF WRN KS/TX PANHANDLE BY 00Z/02. LATEST WATER VAPOR IMAGERY DEPICTS A WELL DEFINED UPPER VORT JUST WEST OF SAN...CLEARLY DEFINED AND LIKELY STRONGER THAN MODELS ARE INDICATING. THIS FEATURE WILL PROVE INSTRUMENTAL IN WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT FROM WRN KS INTO THE TX PANHANDLE BY 21Z. LATE EVENING DIAGNOSTIC DATA AND TRENDS SUGGEST BOUNDARY LAYER RECOVERY IS WELL UNDER WAY ACROSS NORTH TX WITH WARM ADVECTION/MOISTENING CONTRIBUTING TO RECENT THUNDERSTORM DEVELOPMENT ACROSS THE TX SOUTH PLAINS...JUST SE OF LBB. IT APPEARS WARM FRONT WILL LIFT INTO OK LATER THIS MORNING AND SLOWLY LOSE ITS IDENTITY. EVEN SO...THUNDERSTORM CLUSTERS MAY BE NOTED WITH THIS RETREAT ACROSS SRN OK...THEN INTO PORTIONS OF AR/LA LATER IN THE MORNING AS BOUNDARY LAYER WARMS/DESTABILIZES. OF MORE CONCERN IS THE EXPECTED RAPID MOISTENING INTO THE TX PANHANDLE/WRN OK INTO WRN KS AHEAD OF UPPER SHORTWAVE. LATEST THINKING IS MODERATE INSTABILITY WILL DEVELOP AS FAR NW AS SWRN KS...WITH SBCAPES IN EXCESS OF 3000 J/KG FARTHER SOUTH INTO THE TX PANHANDLE/WRN OK WHERE MID 60S DEW POINTS WILL BE IN PLACE AHEAD OF THUNDERSTORM INITIATION. IT APPEARS CONVECTION WILL INITIATE PRIOR TO 21Z OVER THE WRN TX PANHANDLE...THEN SPREAD/DEVELOP EWD INTO VERY FAVORABLE ENVIRONMENT FOR SUPERCELLS. FORECAST SOUNDINGS STRONGLY FAVOR TORNADO DEVELOPMENT IF BOUNDARY LAYER MOISTURE DOES INDEED RETURN AS EXPECTED. VERY LARGE HAIL WILL ALSO ACCOMPANY THIS ACTIVITY AS IT SPREADS DOWNSTREAM. BY LATE EVENING AN UPWARD EVOLVING LINEAR MCS WITH EMBEDDED SUPERCELLS AND BOW ECHOES SHOULD SPREAD ACROSS THE REMAINDER OF CNTRL KS/OK TOWARD WRN MO BY THE END OF THE PERIOD. ...LOWER MS VALLEY... RETREATING WARM FRONT ACROSS THE ARKLATEX REGION WILL ENHANCE INSTABILITY/FOCUS FOR LATE MORNING INTO AFTERNOON THUNDERSTORM CLUSTERS ACROSS AR INTO WRN MS. WEAK WARM ADVECTION MAY AID INITIAL THUNDERSTORM DEVELOPMENT...HOWEVER DAYTIME HEATING SHOULD ALSO CONTRIBUTE TO STRONGER THUNDERSTORM ACTIVITY. LARGE HAIL AND DAMAGING DOWNBURSTS SHOULD BE THE PRIMARY FOCUS BEFORE CONVECTION WEAKENS AND LIFTS NEWD INTO THE TN VALLEY LATER IN THE EVENING. ...NERN U.S... A NARROW WEDGE OF MOISTENING/HEATING WILL OCCUR AHEAD OF COLD FRONT ACROSS NY INTO PORTIONS OF SRN NEW ENGLAND LATER THIS MORNING. FORECAST SOUNDINGS ACROSS THE HUDSON VALLEY INTO ERN PA SUGGEST 200-400 J/KG SFC-BASED INSTABILITY WILL DEVELOP PRIOR TO FRONTAL PASSAGE. IT APPEARS A FORCED LINE OF LOW TOPPED THUNDERSTORMS WILL EVOLVE ALONG THE WIND SHIFT THEN SURGE EWD ACROSS THE REMAINDER OF NEW ENGLAND DURING THE AFTERNOON. FORECAST SHEAR AND THE POSSIBILITY FOR WLY MOMENTUM TRANSFER ARE NOT THAT SIGNIFICANT GIVEN THE WEAK INSTABILITY ENVIRONMENT. FORECAST STORM MOTIONS SUGGEST LOCALLY STRONG/DAMAGING WIND GUSTS WITH MORE ORGANIZED CELLS...HOWEVER AT THIS TIME IT APPEARS COVERAGE OF SEVERE WIND GUSTS WILL NOT WARRANT A SLIGHT RISK. ..DARROW.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 12:44:13 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 07:44:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011241 SWODY1 SPC AC 011240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST SAT APR 01 2006 VALID 011300Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF WRN OK...SWRN KS...ERN TX PANHANDLE LATE THIS AFTERNOON AND EARLY TONIGHT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SRN/CENTRAL PLAINS... ...WIDESPREAD SEVERE THUNDERSTORMS WILL DEVELOP ACROSS A CONCENTRATED AREA OF THE CENTRAL/SOUTHERN HIGH PLAINS LATER TODAY... ...SRN/CENTRAL PLAINS... DRY LINE SEVERE PATTERN...MORE TYPICAL LATER IN THE SPRING...WILL DEVELOP FROM WRN KS INTO PORTIONS OF WRN TX/OK TODAY AND TONIGHT. PRESSURE FALLS AHEAD OF LOW AMPLITUDE SHORTWAVE TROUGH...NOW LIFTING NEWD ACROSS THE SRN ROCKIES...WILL INCREASE SSELY LOW LEVEL FLOW INTO THE SRN/CENTRAL HIGH PLAINS THROUGH THE AFTERNOON. AS THIS OCCURS...BOUNDARY LAYER MOISTURE WILL QUICKLY INCREASE DUE TO BOTH DOWNWARD MIXING AND ADVECTION UNDER STRONG CAP EVIDENT AT FTW/OUN THIS MORNING...WITH AXIS OF 50+F SURFACE DEW POINTS EXPECTED INTO WRN KS AND MID/UPPER 60F DEW POINTS ALONG AND SOUTH OF I-40 BY LATE THIS AFTERNOON. MODELS ARE IN AGREEMENT IN MIXING DRY LINE/LEE TROUGH ALONG AN AXIS EXTENDING FROM NEAR THE KS/CO BORDER SWD INTO THE CENTRAL TX PANHANDLE BY 21Z...WHICH THEN PROGRESSES EWD INTO WRN OK/CENTRAL KS THIS EVENING IN WAKE OF DEEPENING LOW CENTER LIFTING INTO SERN NEB OVERNIGHT. HEATING AND MOISTENING WITHIN THE BOUNDARY LAYER WILL BE AUGMENTED BY INCREASING LARGE SCALE ASCENT AND SUPPORT RAPID SEVERE THUNDERSTORM DEVELOPMENT FROM SWRN KS INTO THE ERN TX PANHANDLE...MOST LIKELY AROUND 21-22Z. STORMS WILL QUICKLY BECOME SUPERCELLS WITH EFFECTIVE BULK-SHEAR NEAR 50 KT...0-2 KM SRH FROM 150-200 M2/S2 AND MLCAPE APPROACHING 2000 J/KG. AS CAP BREAKS AND STRONGEST ASCENT OVERSPREADS THE REGION...STORMS WILL BECOME INCREASINGLY WIDESPREAD WITH POTENTIAL FOR VERY LARGE HAIL AND TORNADOES. CAPPING WILL LIMIT SWD DEVELOPMENT ALONG DRY LINE INTO MORE OF WRN TX. HOWEVER...SHEAR WILL REMAIN SUPPORTIVE OF SUPERCELLS SHOULD AN ISOLATED STORM OR TWO DEVELOP LATER TODAY. TORNADO THREAT WILL LIKELY INCREASE AROUND 00Z AS SUPERCELLS MATURE...LOW LEVEL RH INCREASES AND LLJ BEGINS TO DECOUPLE/INTENSIFY. FORECAST SOUNDINGS...ESPECIALLY INTO RICHER BOUNDARY LAYER MOISTURE OVER SWRN OK/NWRN TX...WILL BECOME FAVORABLE FOR SIGNIFICANT TORNADOES LATE TODAY AND EARLY THIS EVENING. ACTIVITY WILL LIKELY ORGANIZE INTO AN MCS AS IT LIFTS ENEWD ACROSS NRN OK/KS THIS EVENING...WITH MORE DISCRETE DEVELOPMENT DIMINISHING DURING THE MID EVENING SOUTH OF I-40 AS CAPPING INCREASES AND LARGE SCALE ASCENT LIFTS INTO THE CENTRAL PLAINS. SEVERE THREAT...MAINLY IN THE FORM OF LARGE HAIL AND ISOLATED DAMAGING WINDS...SHOULD SPREAD INTO PORTIONS OF SRN NEB AND ERN KS/WRN MO LATER TONIGHT. ...SERN OK INTO THE LOWER MS RIVER VALLEY... MODELS INDICATE CAP WILL REMAIN WEAK ALONG STALLED SURFACE FRONT NOW EXTENDING ROUGHLY E-W ACROSS THIS REGION. DEEP LAYER SHEAR IS FORECAST TO REMAIN MODEST...20-30 KT OF 0-6 KM SHEAR...WITH WEAK LAPSE RATES EVIDENT ON MORNING SOUNDINGS. THUS...DESPITE MODERATE INSTABILITY...SEVERE THREAT WILL LIKELY REMAIN LIMITED TODAY THOUGH AN ISOLATED LARGE HAIL/DAMAGING WIND SHOULD ACCOMPANY STRONGER CELLS. ...NEW ENGLAND ACROSS THE CHESAPEAKE REGION... BROAD AREA OF 50+ SURFACE DEW POINTS AND RATHER WARM SURFACE TEMPERATURES WILL SUPPORT MARGINAL INSTABILITY AHEAD OF SURFACE COLD FRONT MOVING ACROSS WRN NY/PA AT 12Z. THIS FRONT WILL CONTINUE EWD OFF THE COAST BY LATER TODAY. CONVECTION HAS ALREADY INCREASED NEAR THE FRONT INTO CENTRAL NY EARLY THIS MORNING /REFERENCE SWOMCD 387 FOR FURTHER DETAILS/. DIURNAL HEATING AND 30-40 KT WSWLY FLOW JUST OFF THE SURFACE SHOULD SUPPORT STRONG TO ISOLATED SEVERE WIND GUSTS WITH THUNDERSTORMS DEVELOPING ALONG AND AHEAD OF THE FRONT FROM PORTIONS OF NEW ENGLAND ACROSS MUCH OF THE MID ATLANTIC/CHESAPEAKE. ..EVANS/CROSBIE.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 16:37:51 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 11:37:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011634 SWODY1 SPC AC 011632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SAT APR 01 2006 VALID 011630Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTERNOON INTO EARLY TONIGHT ACROSS WRN OK...THE ERN TX PANHANDLE...AND SW KS.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NW TX NWD TO SE NEB THROUGH TONIGHT...AND SEWD ACROSS ERN OK INTO SW AR THIS AFTERNOON.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS THE TIDEWATER AREA.... ...SRN PLAINS THIS AFTERNOON INTO TONIGHT... BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S WILL CONTINUE TO SPREAD NWD ACROSS OK/KS/NW TX...IN RESPONSE TO CYCLOGENESIS ACROSS ERN CO/WRN KS IN ADVANCE OF A LEAD SHORTWAVE TROUGH PROGRESSING EWD/ENEWD OVER WRN NM/CO THIS MORNING. S OF THE DEVELOPING SURFACE LOW...A DRYLINE WILL BECOME BETTER DEFINED BY LATE AFTERNOON ACROSS THE CENTRAL TX PANHANDLE. 12Z UPPER AIR ANALYSES AND 00-12Z CHANGES IN OBSERVED SOUNDINGS SUGGEST THAT CONVECTIVE INHIBITION WILL BE MINIMIZED E OF THE DRYLINE WITH AFTERNOON TEMPERATURES IN THE UPPER 70S TO LOWER 80S...AND THAT STORM INITIATION IS LIKELY BY ABOUT 22Z ACROSS THE CENTRAL TX PANHANDLE. STORMS SHOULD THEN MOVE EWD/NEWD INTO SW KS AND WRN OK DURING THE EVENING AND EARLY OVERNIGHT HOURS...AND CONTINUE THROUGH MOST OF THE NIGHT ACROSS KS INTO NRN OK. SUBSTANTIAL LOW-LEVEL MOISTENING TODAY BENEATH 8 C/KM MID LEVEL LAPSE RATES WILL RESULT IN STRONG DESTABILIZATION THROUGH THE AFTERNOON E OF THE DEVELOPING DRYLINE AND S OF THE WARM FRONT...WHERE MLCAPE VALUES OF 2000-3500 J/KG APPEAR LIKELY. THOUGH VERTICAL SHEAR WILL BE SOMEWHAT LIMITED THROUGH MID AFTERNOON...INCREASING LOW-MID LEVEL FLOW FROM 21-03Z WILL RESULT IN INCREASINGLY FAVORABLE HODOGRAPH STRUCTURES FOR SUPERCELLS WITH TORNADOES AND VERY LARGE HAIL AS CONVECTION MOVES INTO W/NW OK THIS EVENING. THE THREAT FOR DAMAGING WINDS WILL GRADUALLY INCREASE DURING THE EVENING AS CONVECTION MERGES AND GROWS UPSCALE INTO MORE OF A LINE/MCS ACROSS OK/KS BY EARLY TONIGHT. ...SE VA AREA THIS AFTERNOON... BOUNDARY LAYER DEWPOINTS REMAIN IN THE UPPER 50S TO LOWER 60S...WHILE STRONG SURFACE HEATING WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S THIS AFTERNOON IN ADVANCE OF A WEAK PRE-FRONTAL TROUGH AND COLD FRONT. THE NET RESULT WILL BE SOUNDING PROFILES WITH VERY STEEP LOW-LEVEL LAPSE RATES AND MLCAPE VALUES AOA 1000 J/KG. ADDITIONALLY...40 KT LOW-MID LEVEL FLOW AND MODEST DEEP LAYER SHEAR MAY SUPPORT A FEW SUPERCELLS AND/OR LINE SEGMENTS CAPABLE OF PRODUCING DAMAGING WINDS AND LARGE HAIL DURING THE AFTERNOON. ..THOMPSON/JEWELL.. 04/01/2006  From SWODY1 at goshenarc.org Sat Apr 1 20:01:14 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 15:01:14 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011958 SWODY1 SPC AC 011956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST SAT APR 01 2006 VALID 012000Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PARTS OF SWRN KS / THE ERN OK AND TX PNHDLS / WRN OK AND NWRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM THE MID MO VALLEY SWD INTO THE SRN PLAINS AND ARKLATEX... --CONCENTRATED SEVERE WEATHER EVENT IS STILL ANTICIPATED THIS AFTERNOON AND TONIGHT OVER PORTIONS OF THE CNTRL AND SRN PLAINS-- ...CNTRL / SRN PLAINS... 19Z MESOANALYSIS INDICATED LEE CYCLONE DEVELOPMENT OCCURRING OVER ERN CO WITH ASSOCIATED WARM FRONT EXTENDING SEWD THROUGH SERN CO/SWRN KS AND INTO NERN OK...WHILE DRY LINE WAS BECOMING BETTER DEFINED FROM E OF DHT TO E OF MAF. RAPID AIR MASS DESTABILIZATION IS IN PROGRESS E OF THE DRY LINE AND S OF THE WARM FRONT FROM NWRN TX ACROSS THE ERN TX/OK PNHDLS AND WRN OK INTO WRN KS. MODIFICATION OF 18Z SOUNDINGS FROM MAF AND AMA FOR MORE MOIST BOUNDARY-LAYER TO THE E YIELDS MLCAPES OF 2000-3000 J/KG AND A WEAKENING CAP. RAPID TSTM DEVELOPMENT IS ANTICIPATED BY 21-22Z ALONG DRY LINE FROM THE TX PNHDL NWD TO ALONG ITS INTERSECTION WITH WARM FRONT AS WEAK SHORTWAVE TROUGH/SPEED MAXIMUM OVER CNTRL NM APPROACHES WRN EDGE OF INSTABILITY AXIS. WHILE VERTICAL SHEAR PROFILES ARE CURRENTLY ONLY MARGINALLY FAVORABLE FOR ORGANIZED SEVERE STORMS...STRENGTHENING LOW-LEVEL SHEAR ALONG WITH INTENSIFICATION OF MID AND HIGH-LEVEL WIND FIELDS WILL RESULT IN VERTICAL SHEAR PROFILES QUITE FAVORABLE FOR INTENSE SUPERCELLS CAPABLE OF DESTRUCTIVE HAIL AND TORNADOES. IT APPEARS THE GREATEST POTENTIAL FOR A FEW STRONG TORNADOES WILL EXIST PRIMARILY BETWEEN 23-03Z AS BOUNDARY-LAYER RH INCREASES AND LOW-LEVEL SHEAR FURTHER INTENSIFIES /I.E. 0-1 KM SRH OF 200-300 M2/S2/. CLUSTERS OF SEVERE TSTMS SHOULD MOVE DEVELOP NEWD ACROSS KS/NEB TONIGHT AS LLJ BROADENS AND INTENSIFIES AHEAD OF MID-LEVEL TROUGH MOVING OUT OF THE ROCKIES. WHILE LARGE HAIL AND DAMAGING WINDS WILL REMAIN THE PRIMARY SEVERE WEATHER THREATS...ISOLATED TORNADOES WILL BE POSSIBLE WITH ANY STORMS THAT CAN REMAIN DISCRETE AND SURFACE-BASED. ...NERN TX / ERN OK / AR / NRN LA... ERN EXTENSION OF WARM FRONT EXTENDS FROM N OF TUL TO NEAR HOT AND THEN EWD ACROSS NRN MS. AIR MASS ALONG AND S OF THIS BOUNDARY IS MOIST WITH DEWPOINTS IN THE 60S...AND WHEN COUPLED WITH DAYTIME HEATING...ENVIRONMENT HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-2000 J/KG. AFTERNOON WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH SHIFTING EWD THROUGH THE ARKLATEX WHICH SHOULD SUPPORT DIURNAL TSTM DEVELOPMENT FROM VICINITY OF WARM FRONT SWD INTO FREE WARM SECTOR. WHILE MID AND HIGH-LEVEL WIND FIELDS ARE NOT PARTICULARLY STRONG...AREA VWPS AND PROFILERS DO SHOW CONSIDERABLE VEERING WITH HEIGHT. POTENTIAL WILL EXIST FOR ORGANIZED...SEVERE TSTMS THIS AFTERNOON INTO EVENING WITH THE THREAT OF LARGE HAIL...DAMAGING WINDS AND PERHAPS A TORNADO OR TWO...ESPECIALLY NEAR WARM FRONT. PERSISTENT TSTM CLUSTER JUST N OF WARM FRONT OVER FAR NERN OK INTO SWRN MO MAY ALSO INTENSIFY THIS AFTERNOON OWING TO INFLUX OF UNSTABLE AIR MASS FROM THE SW...WITH SEVERE WEATHER POTENTIAL DEVELOPING ACROSS SWRN MO. ...SERN VA / NERN NC... STRONG DAYTIME HEATING AND RESULTANT STEEPENING OF LOW-LEVEL LAPSE RATES HAVE CONTRIBUTED TO AIR MASS DESTABILIZATION AHEAD OF COLD FRONT AND PRE-FRONTAL TROUGH ACROSS THE TIDEWATER REGION WITH MLCAPES OF AROUND 1000 J/KG. WATER VAPOR IMAGERY SHOWS A COMPACT VORTICITY MAXIMUM TRANSLATING EWD THROUGH CHESAPEAKE BAY INTO DE WHICH IS LIKELY CONTRIBUTING TO SOME INTENSIFICATION OF ONGOING STORMS. SOME POTENTIAL EXISTS FOR THE SWWD DEVELOPMENT OF TSTMS ACROSS SERN VA INTO NERN NC LATE THIS AFTERNOON INTO EARLY EVENING AS SURFACE FRONT MOVES THROUGH AREA. THOUGH ISOLATED LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH ANY ADDITIONAL STORMS THAT DEVELOP...IT APPEARS THAT THIS THREAT IS TOO LIMITED TO WARRANT A CATEGORICAL OUTLOOK. ..MEAD.. 04/01/2006  From SWODY1 at goshenarc.org Sun Apr 2 01:05:08 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 01 Apr 2006 20:05:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020102 SWODY1 SPC AC 020101 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0701 PM CST SAT APR 01 2006 VALID 020100Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SOUTHERN KANSAS...WESTERN OKLAHOMA, AND WESTERN NORTH TEXAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL PLAINS INTO OK/TX AND WRN PARTS OF MO/AR... ...CENTRAL AND SRN PLAINS... N-S CLUSTER OF SEVERE STORMS/SUPERCELLS IS NOW SHIFTING ACROSS CENTRAL KS/WRN OK/WRN N TX...INTO INTO INCREASINGLY-MOIST/ MODERATELY-UNSTABLE AIRMASS. SLY LOW-LEVEL JET HAS BEGUN TO INCREASE...AND WILL CONTINUE TO DO SO THIS EVENING AS UPPER TROUGH CONTINUES SHIFTING EWD INTO THE REGION. THIS COMBINED WITH 50 KT WSWLY MID-LEVEL JET WILL YIELD INCREASINGLY-FAVORABLE DEEP-LAYER SHEAR FOR SEVERE/SUPERCELL STORMS. THEREFORE...EXPECT STORMS TO REMAIN CAPABLE OF PRODUCING VERY LARGE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONALLY...WITH SURFACE LOW FORECAST TO LINGER OVER WRN KS THROUGH THE EVENING...RESULTING SSWLY SURFACE WINDS VEERING/INCREASING TO SWLY AT 40-PLUS KT NEAR 3 KM WILL YIELD LOW-LEVEL SHEAR SUPPORTIVE OF A COUPLE OF STRONG TORNADOES. ...AR/WRN MO... THUNDERSTORMS CONTINUE INVOF WARM FRONT/WITHIN ZONE OF STRONG LOW-LEVEL WARM ADVECTION. AIRMASS REMAINS UNSTABLE INVOF FRONT /500 TO 1000 J/KG MEAN-LAYER CAPE/...BUT SHEAR REMAINS SOMEWHAT LIMITED ATTM. HOWEVER...AS UPPER TROUGH AND ASSOCIATED MID-LEVEL JET STREAK SHIFT EWD OVERNIGHT...SHEAR WILL INCREASE ACROSS AR AND WRN MO. THEREFORE...EXPECT THREAT FOR HAIL AND LOCALLY DAMAGING WINDS TO PERSIST THROUGH THE NIGHT. ..GOSS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 06:03:48 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 01:03:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020601 SWODY1 SPC AC 020559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 PM CST SAT APR 01 2006 VALID 021200Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS EASTERN MISSOURI...SOUTHEAST IOWA...MUCH OF ILLINOIS...SOUTHWEST INDIANA...AND WESTERN KENTUCKY.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN FRINGES OF THE PLAINS TO THE APPALACHIANS... ...SYNOPSIS... MID-LEVEL SHORT-WAVE TROUGH IS FORECAST TO DEEPEN WHILE SHIFTING EWD FROM THE PLAINS ACROSS THE MS VALLEY AND INTO THE UPPER GREAT LAKES/OH AND TN VALLEYS THROUGH THE END OF THE PERIOD. A 70-PLUS KT H5 JET STREAK IS FORECAST TO ACCOMPANY THIS TROUGH...WITH THE CORE OF THIS JET EXPECTED FROM THE CENTRAL PLAINS EWD ACROSS THE OZARKS/MID MS VALLEY REGION AND INTO THE TN AND OH VALLEYS. AT THE SURFACE...LOW INITIALLY FORECAST OVER ERN NEB SHOULD DEEPEN AND MOVE ENEWD WITH TIME...EVENTUALLY REACHING LOWER MI AS A 990 MB CYCLONE. WARM FRONT INITIALLY FORECAST TO EXTEND SEWD ACROSS MO INTO THE SERN U.S. SHOULD LIFT NEWD ACROSS THE TN AND OH VALLEYS WITH TIME...ALLOWING MOIST/UNSTABLE WARM SECTOR TO SPREAD ACROSS THE MID MS VALLEY REGION AHEAD OF COLD FRONT. THIS COLD FRONT SHOULD CROSS MO DURING THROUGH THE AFTERNOON...AND THEN CONTINUE EWD ACROSS THE OH VALLEY REGION THROUGH THE OVERNIGHT HOURS. TRAILING PORTION OF THE FRONT SHOULD SAG MORE SLOWLY SWD...LINGERING ACROSS AR AND TX THROUGH THE END OF THE PERIOD. ...MID MS/OH/TN VALLEYS... POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE APPEARS TO BE SETTING UP THIS PERIOD...CENTERED ON THE MID MS AND LOWER OH VALLEY REGION. THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE MIDDLE AND LOWER MO VALLEY AHEAD OF APPROACHING UPPER TROUGH. THIS CONVECTION SHOULD SHIFT EWD/NEWD INTO THE UPPER GREAT LAKES REGION THROUGH THE DAY. THOUGH THIS INITIAL CONVECTION COMPLICATES THE FORECAST DUE TO ITS POTENTIAL EFFECTS ON AFTERNOON DESTABILIZATION...IT APPEARS ATTM THAT MOST OF THE CONVECTION SHOULD VACATE THE MID MS VALLEY REGION BY AFTERNOON...ALLOWING DAYTIME HEATING TO COMMENCE. PRESUMING THIS OCCURS...1500 TO 2500 J/KG MEAN-LAYER CAPE SHOULD DEVELOP ACROSS THE WARM SECTOR...AIDED BY NWD ADVECTION OF LOW TO MID 60S DEWPOINTS BENEATH STEEPENING MID-LEVEL LAPSE RATES. STORMS SHOULD REDEVELOP BY MID AFTERNOON -- LIKELY FROM SERN IA SWD ACROSS THE ERN HALF OF MO AHEAD OF ADVANCING COLD FRONT. DEEP-LAYER WIND FIELD SHOULD BE QUITE STRONG ACROSS THIS REGION...AS POTENT MID-LEVEL JET SHIFTS EWD INTO THE REGION. ALONG WITH FAVORABLE DEEP-LAYER SHEAR FOR SUPERCELLS...LOW-LEVEL SHEAR WILL ALSO BE STRONG -- PARTICULARLY FROM ERN IA SWD ACROSS ERN MO AND IL NEAR AND SE OF SURFACE LOW. DEGREE OF LOW-LEVEL SHEAR ALONG WITH MOIST/MODERATELY-UNSTABLE AIRMASS SUGGESTS THAT SEVERAL TORNADOES WILL LIKELY OCCUR...A FEW OF WHICH COULD BE STRONG AND LONG-LIVED. ADDITIONALLY...LARGE HAIL AND LOCALLY DAMAGING WINDS ARE ALSO EXPECTED. WITH TIME...STORMS SHOULD BECOME MORE LINEAR -- PARTICULARLY ACROSS THE OH VALLEY WHERE FLOW WILL BECOME MORE VEERED/UNIDIRECTIONAL WITH HEIGHT THROUGH THE EVENING. GIVEN STRENGTH OF THE WIND FIELD...MORE ORGANIZED/WIDESPREAD DAMAGING WIND EVENT MAY EVOLVE/MOVE EWD ACROSS THIS REGION. STORMS SHOULD CONTINUE THROUGH THE END OF THE PERIOD...WITH SEVERE THREAT EXTENDING AS FAR E AS THE CENTRAL APPALACHIANS BY 03/12Z. ..GOSS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 12:33:24 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 08:33:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021231 SWODY1 SPC AC 021229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT SUN APR 02 2006 VALID 021300Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER CENTRAL/ERN MO...FAR SERN IA...WRN/SRN IL...FAR WRN KY THIS AFTERNOON INTO THE EVENING... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM NERN TX/LOWER MS RIVER VALLEY INTO THE SRN GREAT LAKES... ...MO ACROSS MID MS/OH/TN RIVER VALLEYS... COMPLEX FORECAST THIS MORNING AS LINEAR MCS CONTINUES TO LIFT NEWD ACROSS THE MID MS RIVER VALLEY...WHICH WILL LIKELY HINDER HEATING/NWD RETURN OF WARM FRONT INTO THE EARLY AFTERNOON. HOWEVER...SURFACE WINDS CONTINUE TO BACK TO SLY BEHIND THIS ACTIVITY WITH STRONG PRESSURE FALLS DEVELOPING TOWARDS SERN IA EARLY THIS MORNING. THIS SHOULD ALLOW BOUNDARY LAYER MOISTURE TO RECOVER TODAY...WITH LOWER TO MID 60F SURFACE DEW POINTS EXPECTED TO LIFT ACROSS MUCH OF MO/LOWER OH RIVER VALLEY BY THE MID AFTERNOON. MID LEVEL LAPSE RATES WILL ALSO BE ABLE TO RELOAD RELATIVELY QUICKLY UNDER VERY STRONG WLY FLOW ALOFT. THOUGH THERE REMAIN SOME QUESTIONS ABOUT AIR MASS QUALITY DUE TO MORNING STORMS...ESPECIALLY REGARDING HIGHER SEVERE PROBABILITIES...OVERNIGHT MODELS CONTINUE TO INDICATE FAVORABLE CONDITIONS FOR SEVERE THUNDERSTORMS/SUPERCELLS BY 21Z AT LEAST INTO CENTRAL MO. AT THIS TIME...EXPECT AXIS OF MODERATE INSTABILITY WITH MLCAPE FROM 1000-2000 J/KG TO NOSE NEAR THE IA/MO BORDER DURING THE MID TO LATE AFTERNOON. AS A RESULT...DEEP ASCENT AND CONVERGENCE ALONG PRIMARY SURFACE TROUGH SHOULD INCREASE SEVERE THUNDERSTORMS FROM WEST TO EAST INTO WRN AND CENTRAL MO AND POSSIBLY SRN IA BETWEEN 18Z-21Z. GIVEN EXPECTED MLCAPE...FORECAST SOUNDINGS CONTINUE TO INDICATE A VERY FAVORABLE SUPERCELL ENVIRONMENT WITH BRN SHEAR AROUND 60 M2/S2 AND SFC-1 KM SRH IN EXCESS OF 150 M2/S2. THUS...A FEW LONGER-LIVED SUPERCELLS AND BOW ECHOES WILL EVOLVE THROUGH THE LATE AFTERNOON. HAIL MAY BECOME QUITE LARGE WITH THIS ACTIVITY...WITH LOCAL HAIL MODEL INDICATING 2+ INCH HAIL FROM MANY OF THE FORECAST SOUNDINGS. SHOULD HEATING/DESTABILIZATION OVERCOME CAP ALONG WARM FRONT...ISOLATED SUPERCELLS MAY ALSO DEVELOP AHEAD OF THIS ACTIVITY ACROSS PORTIONS OF SRN/CENTRAL IL AND WRN IND. TORNADOES WILL ALSO REMAIN POSSIBLE AND WIND DAMAGE THREAT MAY BECOME ENHANCED AS STORMS SHIFT QUICKLY EWD AT 40-50 KT AND CONSOLIDATE INTO SMALL BOW ECHOES/LINES INTO THE EARLY EVENING. DEPENDING ON WHERE WARM FRONT SETS-UP...GREATER SEVERE THREAT WILL SPREAD INTO SRN/CENTRAL IL INTO THE EARLY EVENING. ACTIVITY SHOULD EVOLVE INTO ONE OR MORE MCSS AND SPREAD EWD ACROSS THE OH/TN RIVER VALLEYS AND THE SRN GREAT LAKES AFTER DARK. LARGE HAIL AND DAMAGING WINDS WILL REMAIN POSSIBLE...WITH AN ISOLATED TORNADO POSSIBLE GIVEN VERY STRONG SHEAR SHOULD STORMS REMAIN ROOTED INTO THE BOUNDARY LAYER. ...MID SOUTH SWWD INTO NERN TX... REGION WILL REMAIN REMOVED FROM STRONGEST LARGE SCALE ASCENT WHICH IS EXPECTED TO SUPPORT MORE WIDESPREAD SEVERE THREAT ALONG AND NORTH OF THE LOWER OH RIVER VALLEY TODAY. HOWEVER...SURFACE CONVERGENCE ALONG SURFACE TROUGH WILL SHIFT INTO WRN AR AND NRN TX BY 21Z...AND SPREAD ESEWD THROUGH THE EARLY EVENING. IN ADDITION...STRONG WLY H85 WINDS WILL MAINTAIN LOW LEVEL WAA ATOP DESTABILIZING WARM SECTOR AND MAY DEVELOP STORMS WELL AHEAD OF THE FRONT TODAY. WARM...EARLY-APRIL TEMPERATURES IN THE UPPER 70S/LOWER 80S WILL WEAKEN CAP AND SUPPORT A LARGE AREA OF MODERATE TO STRONG INSTABILITY GIVEN MID 60F SURFACE DEW POINTS ALREADY IN PLACE. SHEAR WILL ALSO REMAIN QUITE STRONG ACROSS THE REGION WITH EFFECTIVE SHEAR NEAR 60 KT AND SFC-1 KM SRH IN EXCESS OF 200 M2/S2. THIS WOULD SUPPORT SUPERCELLS...AND TORNADOES ACROSS THE MID SOUTH...SHOULD CAP BREAK AND VIGOROUS STORMS DEVELOP. ..EVANS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 16:38:37 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 12:38:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021635 SWODY1 SPC AC 021634 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CDT SUN APR 02 2006 VALID 021630Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS CENTRAL/ERN MO...SRN/WRN IL...EXTREME SERN IA...EXTREME NERN AR...EXTREME NWRN TN...WRN KY.... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM E TX TO WRN NC TO OH/SRN LOWER MI TO SERN NEB.... ...SYNOPSIS... PROGRESSIVE SHORTWAVE PATTERN ALOFT WILL FEATURE TWO-WAVE SYSTEM NOW CAUSING HEIGHT FALLS ACROSS MID/UPPER MS VALLEY REGION. INITIAL TROUGH OVER CENTRAL KS AND OK IS EXPECTED TO ACCELERATE EWD THEN NEWD ACROSS MO/IL/IA THROUGH 3/00Z...THEN WEAKEN THEREAFTER ACROSS PORTIONS INDIANA/LM/LOWER MI. MEANWHILE UPSTREAM SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN NEB/NERN CO/SERN WY -- WILL DIG SEWD ACROSS KS. EXPECT THIS FEATURE TO BECOME DOMINANT PERTURBATION AS IT PIVOTS EWD OVER MID MS VALLEY OVERNIGHT...REACHING FROM SRN LOWER MI TO WRN TN BY END OF PERIOD. AT SFC..CYCLONE OVER SERN NEB SHOULD MOVE ENEWD ACROSS ERN IA..DEEPENING/OCCLUDING TONIGHT AS IT APCHS/CROSSES SRN LM. ASSOCIATED COLD FRONT WILL MOVE SWD/SEWD ACROSS MUCH OF MO...OK AND SRN HIGH PLAINS...CATCHING UP WITH DRYLINE INITIALLY ANALYZED FROM SERN KS INTO SWRN OK. WARM FRONT -- ANALYZED AT 15Z FROM SERN NEB EWD ACROSS NERN MO...THEN SEWD OVER EXTREME SRN IL AND EXTREME WRN KY -- IS FCST TO LIFT NEWD ACROSS REMAINDER MO...MOST OF IL/KY AND PORTIONS SRN INDIANA THROUGH 3/00Z. ILL-DEFINED OUTFLOW BOUNDARY IS EVIDENT FROM E-CENTRAL AND CENTRAL AR NWWD ACROSS SWRN MO AND SWRN KS...AND SHOULD WEAKEN WITH TIME. ...E-CENTRAL PLAINS TO SRN GREAT LAKES AND OH VALLEY... SOME SEVERE POTENTIAL EXISTS AS INITIALLY ELEVATED TSTMS OVER N-CENTRAL/NERN KS AND SERN NEB MOVE EWD INTO DESTABILIZING LOW LEVEL ENVIRONMENT. OPTIMALLY STEEP MIDLEVEL LAPSE RATES ARE EVIDENT ATTM OVER PORTIONS NERN KS/SERN NEB...IN ZONE OF STRONGEST MIDLEVEL DPVA...AHEAD OF COLD-CORE LOW. REF SPC MESOSCALE DISCUSSION 400 FOR NEAR-TERM FCST DETAILS. THIS ACTIVITY AND/OR ADDITIONAL DEVELOPMENT OVER MO VALLEY REGION SHOULD MOVE EWD ACROSS MO INTO IL...AMIDST INCREASINGLY FAVORABLE DEEP-LAYER INSTABILITY. CONVECTIVELY STABILIZED BOUNDARY LAYER AIR MASS IS EVIDENT BETWEEN DIFFUSE OUTFLOW BOUNDARY AND WARM FRONT...WHICH WILL TEMPORARILY SUPPRESS SFC-BASED SEVERE POTENTIAL. EXPECT MOIST ADVECTION TO OFFSET VERTICAL MIXING WITHIN BOUNDARY LAYER AS MOISTURE RECOVERS OVER THIS REGION THROUGH MID-AFTERNOON. THIS SHOULD RESULT IN LOW-MID 60S F SFC DEW POINTS SPREADING NEWD FROM NERN OK/SERN KS/NRN AR REGION...ACROSS MORE OF MO THROUGH MID-LATE AFTERNOON. AS THIS OCCURS...SFC AIR MASS WILL DESTABILIZE CONSIDERABLY IN TUNE WITH STEEPENING MIDLEVEL LAPSE RATES. SHEAR PROFILES BY MID/LATE AFTERNOON AND EARLY EVENING WILL SUPPORT BOTH SUPERCELL AND BOW ECHO STRUCTURES...AND MIXED CONVECTIVE MODE IS EXPECTED. STRONG PRIMARY ARC OF ASCENT -- EXPECTED TO MOVE EWD ACROSS MO/SRN IA/IL -- SHOULD LEAD TO SOME LINEAR SEGMENTS WITH TIME. HOWEVER...DISCRETE SUPERCELLS ALSO ARE POSSIBLE BOTH EARLY IN EVOLUTION OF MAIN BAND AND FARTHER E IN WARM SECTOR. DAMAGING HAIL/GUSTS AND TORNADOES ALL ARE POSSIBLE...WITH SIGNIFICANT-TORNADO PROBABILITIES GREATEST INVOF WARM FRONT WHERE LOW LEVEL HODOGRAPHS AND DEEP-LAYER BULK SHEAR SHOULD BE MAXIMIZED. ACTIVITY SHOULD CONSOLIDATE INTO ONE OR MORE QUASI-LINEAR MCS OVERNIGHT...MOVING ENEWD ACROSS OH VALLEY AND SRN GREAT LAKES REGIONS. MAIN THREAT SHOULD BE DAMAGING WIND AND OCCASIONAL HAIL...THOUGH VERTICAL SHEAR PROFILES STILL WILL BE FAVORABLE FOR A FEW TORNADOES. ...ARKLATEX REGION...E TX...LOWER MS VALLEY... REF WW 129 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST SITUATION OVER PORTIONS CENTRAL/E TX. LATER THIS AFTERNOON...DECREASING CONVERGENCE IS EXPECTED WITH SWD EXTENT ACROSS OZARKS INTO ARKLATEX REGION AND NRN MS...AND WITH TIME OVER SAME REGION. THIS IS RELATED TO WEAKENING SFC WINDS AND SWLY FLOW IN MOIST LAYER. HOWEVER...WEAK CAPPING HAS ALLOWED DEVELOPMENT OVER PORTIONS CENTRAL TX...WITH MORE ACTIVITY POSSIBLY ENEWD TOWARD SRN AR/NRN LA AND EVENTUALLY NRN MS. SEVERE POTENTIAL FROM ANY ACTIVITY THAT DEVELOPS STILL WARRANTS CATEGORICAL SLGT RISK BECAUSE OF FAVORABLE DEEP-LAYER SHEAR AND BOUNDARY LAYER THETAE THAT WILL BE AVAILABLE. ..EDWARDS.. 04/02/2006  From SWODY1 at goshenarc.org Sun Apr 2 19:58:40 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 15:58:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021956 SWODY1 SPC AC 021955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SUN APR 02 2006 VALID 022000Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER ERN MO / FAR SERN IA / PORTIONS OF CNTRL AND SRN IL / WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM THE SRN GREAT LAKES AND OH VALLEY SWD INTO ERN TX AND THE TN VALLEY... ...IA/MO EWD INTO THE SRN GREAT LAKES AND OH VALLEY... LATEST MESOANALYSIS INDICATES SURFACE LOW OVER SWRN IA /SW OF DSM/ WHICH WILL CONTINUE TO DEVELOP NEWD...EVENTUALLY REACHING SRN LOWER MI MONDAY MORNING. ASSOCIATED WARM FRONT /NOW ANALYZED FROM THE LOW EWD ACROSS SRN IL/SWRN IND INTO CNTRL KY WILL CONCURRENTLY LIFT NEWD WHILE TRAILING COLD FRONT PUSHES EWD THROUGH MO INTO THE OH VALLEY. DIABATIC HEATING COUPLED WITH INFLUX OF LOW-LEVEL MOISTURE FROM THE SRN LOW PLAINS HAS CONTRIBUTED TO AIR MASS DESTABILIZATION S OF WARM FRONT AND E OF PACIFIC COLD FRONT WITH 18Z SGF SOUNDING INDICATING MLCAPES OF AROUND 2000 J/KG. SATELLITE AND RADAR DATA INDICATE SURFACE-BASED STORMS DEVELOPING FROM CDJ SWD TO SGF OWING INCREASED LARGE-SCALE FORCING ASSOCIATED WITH SHORTWAVE TROUGH OVER ERN NEB/KS ERODING REMAINING PORTION OF CAP ALONG WRN EDGE OF INSTABILITY AXIS. REGIONAL VADS/VWPS ACROSS WARM SECTOR INDICATE 40-50 KTS OF DEEP-LAYER SHEAR...SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE...DESTRUCTIVE HAIL...DAMAGING WINDS AND A FEW TORNADOES. IT APPEARS THE BEST POTENTIAL FOR A STRONG TORNADO OR TWO WILL EXIST WITHIN ZONE OF BACKED SURFACE WINDS AHEAD OF SURFACE LOW AND NEAR WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE MAXIMIZED. EXPECT THAT A GRADUAL UPSCALE GROWTH INTO LINE SEGMENTS OR QUASI-LINEAR MCS/S TO DEVELOP TONIGHT WITH THREAT OF PRIMARILY DAMAGING WINDS AND LARGE HAIL SPREAD EWD INTO THE OH VALLEY. ...AR/E TX EWD INTO THE TN AND LOWER MS VALLEYS... STRONG DAYTIME HEATING COUPLED WITH DEWPOINTS IN THE 70S AND STEEP LAPSE RATES HAVE CONTRIBUTED TO A MODERATELY UNSTABLE AIR MASS THIS AFTERNOON WITH MLCAPES OF 2000-2500 J/KG AHEAD OF PACIFIC COLD FRONT OR ADVECTIVE DRY LINE. ALOFT...WATER VAPOR IMAGERY INDICATES A CYCLONICALLY CURVED BELT OF WEAK ASCENT AHEAD OF CNTRL PLAINS SHORTWAVE TROUGH FROM CNTRL AR SWWD THROUGH THE ARKLATEX INTO SERN TX...WHICH SHOULD CONTINUE EWD TODAY. GIVEN THAT STRONGEST LARGE-SCALE FORCING AND LOW-LEVEL CONVERGENCE WILL REMAIN N AND NE OF REGION...THERE IS SOME UNCERTAINTY REGARDING EVOLUTION OF CONVECTIVE CLUSTER OVER NERN TX/NWRN LA...AS WELL AS POTENTIAL FOR ADDITIONAL DEVELOPMENT ALONG SURFACE FRONT. VISIBLE SATELLITE IMAGERY WOULD SUGGEST THAT PRE-FRONTAL BOUNDARY-LAYER IS BECOMING CONDITIONED SUCH THAT ADDITIONAL DEEP CONVECTION MAY BECOME INCREASINGLY LIKELY THROUGH THE AFTERNOON FROM WRN/CNTRL AR SWWD INTO ERN TX. GIVEN THE MODERATE INSTABILITY AND PRESENCE OF 50-60 KT WSWLY MID-LEVEL FLOW...POTENTIAL WILL EXIST FOR THE DEVELOPMENT AND MAINTENENCE OF SEVERE STORMS...INCLUDING SUPERCELLS CAPABLE OF LARGE HAIL...DAMAGING WINDS AND POSSIBLY A COUPLE OF TORNADOES. FARTHER TO THE E...SMALL MCS CONTINUES THIS AFTERNOON OVER NRN MS/WRN TN WITH RECENT DEVELOPMENT NEWD INTO MIDDLE TN...TO THE S OF WARM FRONT LIFTING NWD THROUGH REGION. HERE TOO...AIR MASS HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-1500 J/KG. ADDITIONALLY...CURRENT BNA VWP INDICATES A FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED STORMS INCLUDING SUPERCELLS. THUS...EXPECT THAT ONGOING MCS SHOULD CONTINUE TO INTENSIFY THROUGH THE AFTERNOON WITH ADDITIONAL SEVERE STORMS POSSIBLE DOWNSTREAM FROM THIS COMPLEX. WHILE LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS...A BRIEF TORNADO OR TWO WILL BE POSSIBLE. ..MEAD.. 04/02/2006  From SWODY1 at goshenarc.org Mon Apr 3 01:18:52 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 21:18:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030116 SWODY1 SPC AC 030114 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0814 PM CDT SUN APR 02 2006 VALID 030100Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHERN INDIANA...SOUTHEAST MISSOURI...NORTHEAST ARKANSAS...WESTERN TENNESSEE AND WESTERN KENTUCKY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS AND WSWWD INTO NERN TX... ...OH/TN VALLEYS... LINE OF STORMS -- WITH EMBEDDED SUPERCELLS -- IS CURRENTLY ARCING SEWD FROM SRN WI INTO SRN INDIANA. MORE ISOLATED SUPERCELLS THEN CONTINUE ARCING SWD/SWWD ACROSS WRN KY INTO NERN AR/WRN TN. WIDESPREAD SEVERE WEATHER IS OCCURRING WITH THIS AREA OF STORMS...INCLUDING REPORTS OF SEVERAL LARGE/DAMAGING TORNADOES. SURFACE LOW IS NOW OBSERVED OVER ERN IA...WITH A WARM FRONT EXTENDING SEWD ACROSS NRN AND ERN IL/SRN INDIANA INTO NRN KY. MEANWHILE...COLD FRONT EXTENDS FROM THE LOW SSEWD ACROSS WRN IL/SERN MO AND THEN SWWD ACROSS NRN AND WRN AR INTO NERN TX. WHILE AIRMASS AHEAD OF COLD FRONT REMAINS MOIST/UNSTABLE...MUCH COOLER/DRIER AIRMASS EXISTS NE OF WARM FRONT. THIS LEAVES ONLY A NARROW WARM SECTOR ACROSS CENTRAL AND SRN IL...WHILE WARM SECTOR BROADENS TO INCLUDE MOST OF KY AND INTO THE TN/LOWER MS VALLEYS. AS STORMS MOVE EWD/ENEWD ACROSS NERN IL INTO NRN AND CENTRAL INDIANA...DAMAGING WIND/TORNADO THREAT SHOULD BEGIN TO SLOWLY DIMINISH WITH TIME...DUE TO MUCH MORE STABLE AIRMASS NE OF WARM FRONT. HOWEVER...THREAT FOR HAIL MAY PERSIST WELL EWD -- PERHAPS INTO SRN LOWER MI/OH AND PERHAPS WRN PA BY THE END OF THE PERIOD. MEANWHILE S OF WARM FRONT AND E OF COLD FRONT...MOIST AND VERY UNSTABLE WARM-SECTOR AIRMASS PERSISTS...WITH 1500 TO 3000 J/KG MEAN-LAYER CAPE FROM NERN TX NEWD ACROSS AR INTO WRN AND CENTRAL KY...MUCH OF TN...AND NRN PORTIONS OF MS AND AL. IN ADDITION TO FAVORABLE INSTABILITY...DEEP-LAYER WIND FIELD REMAINS QUITE STRONG...INCLUDING 80-PLUS KT H5 JET STREAK NOW CENTERED OVER SRN MO...WHICH IS FORECAST TO SHIFT ACROSS THE OH/TN VALLEYS OVERNIGHT. GIVEN FAVORABLE DEEP-LAYER SHEAR...EXPECT SCATTERED SUPERCELLS OVER NERN AR/WRN KY/WRN TN TO CONTINUE FOR SEVERAL HOURS...WHILE MORE LINEAR STORMS CONTINUE EWD ACROSS THE OH VALLEY REGION. ALONG WITH A CONTINUED THREAT FOR STRONG TORNADOES AND LARGE HAIL...RELATIVELY WIDESPREAD DAMAGING WIND EVENT MAY ALSO EVOLVE WITH TIME. STORMS MAY CROSS THE APPALACHIANS BY THE END OF THE PERIOD...THOUGH SEVERE THREAT SHOULD REMAIN CONFINED TO AREAS W OF THE APPALACHIAN CREST...AS MUCH DRIER BOUNDARY LAYER EXISTS E OF THE MOUNTAINS. ..GOSS.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 01:22:45 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 02 Apr 2006 21:22:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030120 SWODY1 SPC AC 030119 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0819 PM CDT SUN APR 02 2006 VALID 030100Z - 031200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHERN INDIANA...SOUTHEAST MISSOURI...NORTHEAST ARKANSAS...WESTERN TENNESSEE AND WESTERN KENTUCKY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS AND WSWWD INTO NERN TX... CORRECTED FOR MODERATE RISK LINE ...OH/TN VALLEYS... LINE OF STORMS -- WITH EMBEDDED SUPERCELLS -- IS CURRENTLY ARCING SEWD FROM SRN WI INTO SRN INDIANA. MORE ISOLATED SUPERCELLS THEN CONTINUE ARCING SWD/SWWD ACROSS WRN KY INTO NERN AR/WRN TN. WIDESPREAD SEVERE WEATHER IS OCCURRING WITH THIS AREA OF STORMS...INCLUDING REPORTS OF SEVERAL LARGE/DAMAGING TORNADOES. SURFACE LOW IS NOW OBSERVED OVER ERN IA...WITH A WARM FRONT EXTENDING SEWD ACROSS NRN AND ERN IL/SRN INDIANA INTO NRN KY. MEANWHILE...COLD FRONT EXTENDS FROM THE LOW SSEWD ACROSS WRN IL/SERN MO AND THEN SWWD ACROSS NRN AND WRN AR INTO NERN TX. WHILE AIRMASS AHEAD OF COLD FRONT REMAINS MOIST/UNSTABLE...MUCH COOLER/DRIER AIRMASS EXISTS NE OF WARM FRONT. THIS LEAVES ONLY A NARROW WARM SECTOR ACROSS CENTRAL AND SRN IL...WHILE WARM SECTOR BROADENS TO INCLUDE MOST OF KY AND INTO THE TN/LOWER MS VALLEYS. AS STORMS MOVE EWD/ENEWD ACROSS NERN IL INTO NRN AND CENTRAL INDIANA...DAMAGING WIND/TORNADO THREAT SHOULD BEGIN TO SLOWLY DIMINISH WITH TIME...DUE TO MUCH MORE STABLE AIRMASS NE OF WARM FRONT. HOWEVER...THREAT FOR HAIL MAY PERSIST WELL EWD -- PERHAPS INTO SRN LOWER MI/OH AND PERHAPS WRN PA BY THE END OF THE PERIOD. MEANWHILE S OF WARM FRONT AND E OF COLD FRONT...MOIST AND VERY UNSTABLE WARM-SECTOR AIRMASS PERSISTS...WITH 1500 TO 3000 J/KG MEAN-LAYER CAPE FROM NERN TX NEWD ACROSS AR INTO WRN AND CENTRAL KY...MUCH OF TN...AND NRN PORTIONS OF MS AND AL. IN ADDITION TO FAVORABLE INSTABILITY...DEEP-LAYER WIND FIELD REMAINS QUITE STRONG...INCLUDING 80-PLUS KT H5 JET STREAK NOW CENTERED OVER SRN MO...WHICH IS FORECAST TO SHIFT ACROSS THE OH/TN VALLEYS OVERNIGHT. GIVEN FAVORABLE DEEP-LAYER SHEAR...EXPECT SCATTERED SUPERCELLS OVER NERN AR/WRN KY/WRN TN TO CONTINUE FOR SEVERAL HOURS...WHILE MORE LINEAR STORMS CONTINUE EWD ACROSS THE OH VALLEY REGION. ALONG WITH A CONTINUED THREAT FOR STRONG TORNADOES AND LARGE HAIL...RELATIVELY WIDESPREAD DAMAGING WIND EVENT MAY ALSO EVOLVE WITH TIME. STORMS MAY CROSS THE APPALACHIANS BY THE END OF THE PERIOD...THOUGH SEVERE THREAT SHOULD REMAIN CONFINED TO AREAS W OF THE APPALACHIAN CREST...AS MUCH DRIER BOUNDARY LAYER EXISTS E OF THE MOUNTAINS. ..GOSS.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 06:02:03 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 02:02:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030559 SWODY1 SPC AC 030557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT MON APR 03 2006 VALID 031200Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHEAST VIRGINIA/EASTERN NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE E COAST STATES FROM THE DELMARVA REGION SSWWD INTO NERN GA... ...SYNOPSIS... MID-LEVEL TROUGH IS FORECAST TO STRENGTHEN AND TAKE ON A MORE NEGATIVE TILT WITH TIME AS IT MOVES EWD ACROSS THE APPALACHIANS EARLY...AND THEN ACROSS THE E COAST STATES THROUGH THE END OF THE PERIOD. STRONG DEEP-LAYER WIND FIELD -- INCLUDING 70 KT MID-LEVEL JET STREAK -- WILL MOVE ACROSS GA AND THE CAROLINAS DURING THE AFTERNOON. AT THE SURFACE...BOUNDARY LAYER MOISTENING WILL OCCUR DURING THE DAY...AHEAD OF APPROACHING COLD FRONT WHICH SHOULD CREST THE APPALACHIANS BY EARLY AFTERNOON. AS CONVECTION REDEVELOPS/INTENSIFIES AHEAD OF THIS BOUNDARY...THREAT FOR SEVERE WEATHER WILL INCREASE ACROSS THE E COAST STATES FROM THE DELMARVA REGION SWD TO GA. ...E COAST STATES... SIGNIFICANT SEVERE WEATHER EPISODE APPEARS LIKELY THIS PERIOD FROM MD/DE/VA SWD INTO NERN GA...AS NEGATIVELY-TILTED UPPER TROUGH MOVES ACROSS THE ERN CONUS. BOUNDARY LAYER IS FORECAST TO MOISTEN THROUGH EARLY AFTERNOON...BENEATH STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH APPROACHING UPPER TROUGH. THIS COMBINED WITH DAYTIME HEATING SHOULD PUSH MEAN-LAYER CAPE VALUES INTO THE 1000 TO 2000 J/KG RANGE BY EARLY AFTERNOON. ATTM...IT APPEARS THAT CONVECTION NOW OVER THE TN VALLEY REGION WILL RE-INTENSIFY AHEAD OF FRONT...INITIALLY FROM WRN VA SSWWD INTO WRN SC AROUND 18Z. DEVELOPING STORMS SHOULD RAPIDLY BECOME SEVERE...AS STRONG DEEP-LAYER WIND FIELD WILL BE IN PLACE ACROSS THIS REGION. STORMS SHOULD ORGANIZE WITH TIME INTO A LINE -- WITH EMBEDDED LEWPS/BOWS/SUPERCELLS ACROSS VA AND NC...WHERE UPPER FORCING SHOULD BE STRONGER. FURTHER S INTO SC AND NERN GA...MORE ISOLATED/CELLULAR CONVECTION IS EXPECTED...WITH SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS. GIVEN FORECAST COMBINATION OF SHEAR AND INSTABILITY...LARGE HAIL AND DAMAGING WINDS APPEAR LIKELY. IN ADDITION...LOW-LEVEL SPEED SHEAR SHOULD BE SUFFICIENT FOR TORNADOES -- WITH A THREAT FOR A FEW STRONGER TORNADOES MOST LIKELY ACROSS THE ERN CAROLINAS AND SERN VA WHERE MODELS SUGGEST BACKED/SSELY SURFACE WINDS AHEAD OF APPARENT LEE TROUGH. SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING...BEFORE STORMS MOVE OFF THE COAST INTO THE WRN ATLANTIC. ..GOSS/JEWELL.. 04/03/2006  From SWODY1 at goshenarc.org Mon Apr 3 12:53:27 2006 From: SWODY1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 08:53:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031251 SWODY1 SPC AC 031249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT MON APR 03 2006 VALID 031300Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF THE ERN CAROLINAS INTO SERN VA TODAY AND EARLY THIS EVENING... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF AL/GA NWD INTO THE UPPER OH RIVER VALLEY AND MID ATLANTIC... ...DELMARVA INTO PORTIONS OF THE SOUTHEAST... SIGNIFICANT MID/UPPER LEVEL TROUGH NOW DIGGING EWD ACROSS THE MID SOUTH WILL EJECT RAPIDLY ENEWD ACROSS THE CENTRAL/SRN APPALACHIANS TODAY. ASSOCIATED 70+ KT MID LEVEL JET IS FORECAST BY ALL THE MODELS TO OVERSPREAD NRN/ERN GA AND CENTRAL SC THROUGH 21Z... MAINTAINING ENHANCED LARGE SCALE ASCENT AND VERY STRONG SHEAR ACROSS THIS REGION. IN ADDITION...PLUME OF ELEVATED-MIXED LAYER AIR HAS OVERSPREAD MUCH OF THE SOUTHEAST AND WILL FEED NEWD INTO THE CAROLINAS TODAY. TLH AND JAX BOTH INDICATE 8+ C/KM LAPSE RATES FROM H7-H5...WITH 7+ C/KM AT CHS. COMBINED WITH VERY STRONG ASCENT AND STRENGTHENING SHEAR...A SIGNIFICANT SEVERE THUNDERSTORM THREAT IS EXPECTED TO UNFOLD INTO THE CENTRAL/ERN CAROLINAS INTO SERN VA TODAY. MCS CONTINUES FROM SUNDAY EVENINGS SEVERE EVENT INTO THE SRN APPALACHIANS THIS MORNING...WHICH WILL LIKELY CONTINUE SPREADING EWD INTO THE PIEDMONT/CENTRAL GA EARLY TODAY. ACTIVITY HAS WEAKENED OVER THE PAST HOUR OR TWO AS CONSOLIDATED OUTFLOW BOUNDARY CONTINUES TO UNDERCUT STRONGER STORMS. HOWEVER...VERY STEEP LAPSE RATES IN PLACE THIS MORNING AND 40-50 KT EFFECTIVE SHEAR WILL MAINTAIN A THREAT OF LARGE HAIL AND ISOLATED DAMAGING WINDS INTO THE MID MORNING WITH THIS ACTIVITY. BY 18Z...STORMS WILL INTENSIFY FROM CENTRAL VA INTO CENTRAL SC ALONG REMNANTS OF THIS OUTFLOW BOUNDARY AND/OR AHEAD OF APPROACHING SURFACE COLD FRONT NOW OVER CENTRAL KY/TN. FORECAST SOUNDINGS INDICATE MLCAPE WILL EXCEED 1500 J/KG INTO THE PIEDMONT...WHERE STRONG LOW AND DEEP LAYER SHEAR AND STEEP LAPSE RATES WILL ENHANCE STORM SCALE ORGANIZATION. ACTIVITY WILL QUICKLY EVOLVE INTO SUPERCELL AND SMALL BOW ECHO STRUCTURES AND RACE EWD THROUGH THE EARLY EVENING. VERY LARGE HAIL AND TORNADOES ARE EXPECTED TO ACCOMPANY THESE STORMS. TORNADO THREAT MAY BE ENHANCED NEAR E-W ORIENTED OUTFLOW BOUNDARY FROM EARLIER STORMS NOW OVER PORTIONS OF SERN NC. WIND DAMAGE THREAT MAY ALSO BECOME WIDESPREAD AS BROKEN SQUALL LINE EVOLVES LATER TODAY. ...ERN OH INTO WRN PA/NRN WV... VERY STRONG LARGE SCALE ASCENT AHEAD OF SURFACE COLD FRONT AND INTENSE MID/UPPER LEVEL TROUGH WILL INTERACT WITH LOWER TO MID 50F SURFACE DEW POINTS OVER THE UPPER OH RIVER VALLEY/LOWER GREAT LAKES THIS MORNING. MODIFIED 12Z SOUNDING AT ILN INDICATED MID/UPPER 60F SURFACE TEMPERATURES WILL SUPPORT MARGINAL SURFACE BASED INSTABILITY. IN ADDITION...VERY STEEP LAPSE RATES AND SIGNIFICANT LOW AND DEEP LAYER SHEAR SHOULD SUPPORT LOW TOPPED SEVERE THUNDERSTORMS...POSSIBLY DEVELOPING BY THE MID MORNING. THIS ACTIVITY WILL POSE DAMAGING WINDS/LARGE HAIL THREATS EWD TOWARDS THE APPALACHIANS...WITH ISOLATED TORNADOES ALSO POSSIBLE. ...CENTRAL GULF COAST STATES INTO ERN TX... AIR MASS WILL REMAIN VERY UNSTABLE ALONG AND SOUTH OF SURFACE COLD FRONT FORECAST TO MOVE SWD INTO CENTRAL/SRN MS AND SRN LA/ERN TX THIS AFTERNOON. THOUGH CAPPING WILL REMAIN PROBLEMATIC FOR INITIATION GIVEN LACK OF LARGE SCALE ASCENT...HEATING AND CONVERGENCE MAY ALLOW A FEW STORMS TO DEVELOP LATER TODAY. JAN/S 12Z SOUNDING REMAINS VERY FAVORABLE FOR SEVERE THUNDERSTORMS... SHOULD ACTIVITY DEVELOP IN GENERAL SUBSIDENT REGIME. THEREFORE... AT LEAST LOW SEVERE PROBABILITIES WARRANTED WSWWD ALONG THIS BOUNDARY INTO PORTIONS OF ERN TX. ..EVANS/JEWELL.. 04/03/2006  From SwoDy1 at goshenarc.org Mon Apr 3 16:39:30 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 12:39:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031637 SWODY1 SPC AC 031635 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 AM CDT MON APR 03 2006 VALID 031630Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER NERN GA..NC..SC..AND SOUTH CENTRAL/SERN VA... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SERN STATES INTO THE UPPER OH VALLEY AND MID ATLANTIC REGION... ...WIDESPREAD SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING FROM THE SOUTHERN AND CENTRAL APPALACHIANS INTO THE CAROLINAS AND VIRGINIA.... ...SYNOPSIS... VIGOROUS UPPER TROUGH EXTENDING FROM THE LOWER GREAT LAKES INTO THE TN VALLEY IS EXPECTED TO BECOME NEGATIVELY TILTED AS IT MOVES TOWARD THE CAROLINAS AND VA...AS UPSTREAM LOW OVER NWRN ONTARIO DIGS SEWD. AT THE SURFACE...PRIMARY LOW OVER THE LOWER LAKES WILL MOVE SLOWLY EWD WITH SECONDARY CYCLOGENESIS EXPECTED OVER THE DELMARVA REGION LATE THIS AFTERNOON AS UPPER LEVEL DIVERGENCE INCREASES IN LEFT EXIT REGION OF MID/UPPER LEVEL JET STREAK MOVING ACROSS THE CAROLINAS. SURFACE COLD FRONT FROM LAKE ERIE SWD THROUGH ERN PARTS OF OH/KY/TN SWWD ACROSS NRN AL AND CENTRAL MS IS FORECAST TO PROGRESS RAPIDLY EWD...REACHING CENTRAL PARTS OF PA..VA..THE CAROLINAS INTO SWRN GA AND WWD ALONG THE GULF COAST BY THIS EVENING...AND OFF THE ATLANTIC COAST TONIGHT. ...SRN APPALACHIANS INTO CAROLINAS AND VIRGINIA... COMPLEX CONVECTIVE SCENARIO HAS BEEN UNFOLDING THIS MORNING WITH EWD MOVING BAND OF PRE-FRONTAL CONVECTION FROM ERN VA SWD INTO GA. ALTHOUGH ISOLATED STRONG/SEVERE STORMS ARE CONTINUING OVER ERN NC...MOST OF THIS ACTIVITY HAS DIMINISHED IN INTENSITY WITH THINNING CLOUDS EVIDENT FROM WRN NC INTO SC AND CENTRAL GA. ASSOCIATED OUTFLOW BOUNDARY EXTENDS ACROSS THE ERN CAROLINAS WWD INTO NRN GA...WITH SC/GA PART OF THE BOUNDARY EXPECTED TO WEAKEN AS SURFACE WINDS BACK TO A MORE SWLY COMPONENT IN RESPONSE TO ONGOING PRESSURE FALLS. 12Z SOUNDINGS SHOWED A PLUME OF STEEP MID LEVEL LAPSE RATES EXTENDING EWD FROM THE LOWER MS VALLEY TO THE SRN ATLANTIC COAST WHICH IS ENHANCING POTENTIAL INSTABILITY ACROSS THE REGION. STRONG INSOLATION IN ADVANCE OF THE AFOREMENTIONED COLD FRONT WILL CONTRIBUTE TO ADDITIONAL DESTABILIZATION THIS AFTERNOON...WITH MLCAPE OF 1500 J/KG EXPECTED ALONG AN AXIS FROM GA INTO NC. CONVECTION IS DEVELOPING FROM THE UPPER OH VALLEY INTO NERN TN ATTM...AND DEVELOPING CU FIELD IS EVIDENT SWWD INTO NWRN GA/NRN AL/CENTRAL MS. AS CAP CONTINUES TO WEAKEN OVER THE SRN APPALACHIANS REGION...THUNDERSTORMS ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON. STRONG DEEP LAYER SHEAR ACROSS THE AREA WILL ENHANCE CONVECTIVE ORGANIZATION AND INTENSITY. STORM COVERAGE WILL LIKELY INCREASE THROUGH THE MID-LATE AFTERNOON ALONG/AHEAD OF THE FRONT...WITH POTENTIAL FOR SEVERAL BANDS OF STRONG/SEVERE STORMS WITH EMBEDDED SUPERCELLS AND BOW SEGMENTS. REMNANTS OF MORNING OUTFLOW BOUNDARY/THERMAL GRADIENT ARE EXPECTED TO LIFT SLOWLY NWD FROM NRN GA ACROSS UPSTATE SC..CENTRAL NC AND EXTREME SERN VA BY LATER THIS AFTERNOON...PROVIDING AN ADDITIONAL MESOSCALE FOCUS FOR SEVERE THUNDERSTORMS. A FEW TORNADOES WILL BE POSSIBLE...ESPECIALLY OVER PARTS OF THE CAROLINAS AND SERN VA WHERE LOW LEVEL SHEAR WILL BE STRONGEST...ALONG WITH VERY LARGE HAIL AND DAMAGING WIND GUSTS. SEVERE THREAT WILL SPREAD EWD TOWARD THE COAST BY THIS EVENING BEFORE ENDING FROM THE WEST BY 03-06Z. ...UPPER OH VALLEY INTO CENTRAL APPALACHIANS... A BAND OF STRONG/SEVERE STORMS HAS DEVELOPED JUST AHEAD OF THE COLD FRONT FROM EXTREME WRN PA INTO ERN KY. THIS ACTIVITY IS EXPECTED TO SPREAD EWD IN ADVANCE OF THE STRONG UPPER LOW APPROACHING WRN LAKE ERIE. ALTHOUGH MORE EXTENSIVE CLOUDS OVER PA MAY INHIBIT DIURNAL HEATING/DESTABILIZATION THIS AFTERNOON... STRONG WINDS IMMEDIATELY ABOVE THE SURFACE WILL AID POTENTIAL FOR DAMAGING WIND GUSTS THROUGH DOWNWARD TRANSFER OF HORIZONTAL MOMENTUM IN CONVECTIVE DOWNDRAFTS. IN ADDITION...THE STRONG LOW LEVEL SHEAR/HELICITY SUGGESTS POTENTIAL FOR A FEW TORNADOES. THIS ACTIVITY WILL LIKELY CONTINUE EWD THROUGH THE AFTERNOON HOURS. ..WEISS/CROSBIE.. 04/03/2006  From SwoDy1 at goshenarc.org Mon Apr 3 20:19:32 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 16:19:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032015 SWODY1 SPC AC 032013 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0313 PM CDT MON APR 03 2006 VALID 032000Z - 041200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS SERN/S-CENTRAL VA...EXTREME S-CENTRAL MD...NC...NRN SC... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM SRN AL TO CENTRAL PA... ...SYNOPSIS... HIGH AMPLITUDE TROUGH -- EVIDENT IN MOISTURE CHANNEL IMAGERY FROM SRN ONT SWD TO ERN TN -- SHOULD MOVE NEWD OVER CENTRAL APPALACHIANS THROUGH REMAINDER PERIOD AS UPPER LEVEL LOW DIGS SEWD FROM NWRN ONT. SMALLER SHORTWAVE NOW MOVING THROUGH BASE OF BROADER SCALE TROUGH OVER SRN APPALACHIANS WILL EJECT NEWD OVER ERN NC/SERN VA EARLY TONIGHT. ASSOCIATED/OCCLUDED SFC LOW WILL MOVE NEWD TOWARD SERN QUE. OCCLUDED FRONT - NOW ANALYZED FROM SRN ONT ACROSS NWRN PA -- SHOULD MOVE EWD ACROSS NY AND NRN PA THROUGH EVENING...WHILE TRAILING COLD FRONT MOVES ACROSS MUCH OF REMAINDER MID-ATLANTIC...VA...CAROLINAS...NRN GA AND AL. WARM FRONT -- ANALYZED FROM SWRN PA SEWD ACROSS ERN VA TO SRN CHESAPEAKE BAY...SHOULD MOVE NEWD ACROSS POTOMAC RIVER AND INTO PORTIONS SRN/CENTRAL MD. ...TIDEWATER REGION THROUGH CAROLINAS/GA... REF WW 147 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST SITUATION ACROSS PORTIONS SRN APPALACHIANS AND ADJACENT PIEDMONT ZONES OF GA/CAROLINAS. REF MESOSCALE DISCUSSION 421 AND WW 148 FOR NEAR-TERM POTENTIAL FROM CENTRAL/NRN NC INTO SRN VA. DAMAGING WIND POTENTIAL WILL CONTINUE THROUGH THIS EVENING WITH CONVECTION AHEAD OF FRONT...AND TORNADOES STILL ARE A CONCERN FROM COASTAL NC INTO PORTIONS VA/SRN MD TIDEWATER REGION. SFC ANALYSIS INDICATES SUBSTANTIAL MIXING-OUT OF BOUNDARY LAYER MOISTURE AHEAD OF PRIMARY CONVECTIVE BAND -- WITH DEW POINTS UPPER 40S TO MID 50S F NOW COMMON ACROSS MUCH OF PIEDMONT FROM VA-GA. SUCH DRYING IN PROSPECTIVE SUBCLOUD LAYER MAY RESULT IN TORNADO POTENTIAL BEING REDUCED...BY ENCOURAGING EVAPORATIVELY COOLED OUTFLOW PLUMES IN SUBCLOUD LAYERS. HOWEVER...THIS ALSO ENCOURAGES DOWNDRAFT ACCELERATION THROUGH BOUNDARY LAYER...AND ENHANCED POTENTIAL FOR DAMAGING GUSTS. THEREFORE WE WILL MAINTAIN MDT RISK...WHOSE THRESHOLD ALREADY WAS BASED ON DAMAGING WIND PROBABILITIES. DEEP-LAYER SHEAR WILL REMAIN FAVORABLE FOR SEVERE ACROSS ENTIRE REGION -- EVEN WHERE FLOW HAS VEERED TO SWLY -- GIVEN STRENGTH OF MID/UPPER LEVEL WINDS. HOWEVER...GREATEST COMBINATION OF INSTABILITY...MOISTURE AND SHEAR SHOULD BE FROM ERN NC THROUGH ERN VA AND PERHAPS SRN MD. LARGEST TORNADO PROBABILITIES WILL BE SHUNTED EWD TOWARD MORE ROBUST MOISTURE INVOF COAST AND NEAR WARM FRONT...WHERE RELATIVELY BACKED SFC FLOW ALSO ENHANCES DEEP-LAYER SHEAR...AND SFC DEW POINTS SHOULD REMAIN IN UPPER 50S TO LOW 60S IN MANY AREAS. EARLIER MCS HAS LEFT BEHIND POOL OF OUTFLOW AIR IN ERN NC THAT IS BEING HEATED/MODIFIED ATTM. LOW LEVEL DRY ADVECTION AND MIXING WILL ERODE WRN EDGE OF THIS PLUME SOMEWHAT...BUT VORTICITY/SHEAR SHOULD REMAIN MAXIMIZED FROM THIS PLUME NWD TO WARM FRONTAL ZONE. ANY RELATIVELY DISCRETE ACTIVITY DEVELOPING IN WARM SECTOR AHEAD OF MAIN CONVECTIVE BAND MAY INTERACT WITH EITHER FAVORABLY MODIFIED OUTFLOW AIR OR WARM FRONT...WHERE BACKED FLOW...ENLARGED HODOGRAPHS...AND LOWER LCL ARE EXPECTED. VIS IMAGERY SHOWS BOUNDARY LAYER BILLOWS OVER E-CENTRAL VA ATTM...INDICATING CAPPING...HOWEVER...AIR MASS SHOULD CONTINUE TO DESTABILIZE WITH INSOLATION OCCURRING IN WAKE OF MORNING CONVECTIVE/CLOUD AREA. ..N-CENTRAL APPALACHIANS/MID-ATLANTIC... ORGANIZED LINE OF TSTMS...INVOF OCCLUDED/COLD FRONTAL ZONE...SHOULD CONTINUE MOVING EWD ACROSS PORTIONS PA/WRN NY THROUGH REMAINDER AFTERNOON INTO EARLY EVENING. MAIN THREAT IS WIND DAMAGE. GIVEN STRENGTH OF VERTICAL SHEAR ACROSS THIS REGION... ISOLATED HAIL AND A TORNADO OR TWO ALSO REMAIN POSSIBLE...PARTICULARLY IN ASSOCIATION WITH EMBEDDED BOWS/MESOCYCLONES. REF WW 146 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR NEAR TERM SITUATION. ACTIVITY SHOULD DIMINISH THIS EVENING AS IT MOVES INTO LOW THETAE BOUNDARY LAYER THAT WILL CONTINUE TO CHARACTERIZE MUCH OF ERN PA...CENTRAL NY AND BEYOND. ..EDWARDS.. 04/03/2006  From SwoDy1 at goshenarc.org Tue Apr 4 00:59:09 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 03 Apr 2006 20:59:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040057 SWODY1 SPC AC 040055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT MON APR 03 2006 VALID 040100Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE MIDDLE ATLANTIC AND SERN U.S.... ...MIDDLE ATLANTIC/SERN U.S... CONVECTION CONTINUES TO DECREASE IN AREAL COVERAGE AND INTENSITY AS IT SPREADS ACROSS THE MIDDLE ATLANTIC REGION THIS EVENING. 00Z SOUNDING FROM WAL WAS NOT PARTICULARLY UNSTABLE WITH ONLY 300 J/KG MUCAPE...ALTHOUGH VERTICAL SHEAR WAS MORE THAN ADEQUATE FOR SUSTAINING ORGANIZED UPDRAFTS. PROXIMITY TO COOLER MARINE LAYER NEAR THE COAST DOES NOT FAVOR STRENGTHENING OF SQUALL LINE...THUS A GRADUAL WEAKENING TREND SHOULD CONTINUE THROUGH THE EVENING HOURS. FARTHER SOUTH...VEERED FLOW ACROSS GA INTO THE CAROLINAS HAS AIDED STEEP LAPSE RATE ENVIRONMENT THAT ENHANCED TEMP/DEW POINT DEPRESSIONS AHEAD OF CONVECTION. HOWEVER...WITH LOSS OF HEATING INSTABILITY HAS DECREASED AND THIS SHOULD FACILITATE CONTINUED WEAKENING OVER THE NEXT FEW HOURS. LARGE HAIL AND LOCALLY STRONG WINDS MAY ACCOMPANY ONGOING ACTIVITY UNTIL THIS TRANSITION OCCURS. ..DARROW.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 05:52:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 01:52:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040549 SWODY1 SPC AC 040548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1248 AM CDT TUE APR 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CA... ...CA... LATE EVENING SATELLITE IMAGERY CLEARLY DEPICTS CENTER OF UPPER CIRCULATION OVER THE ERN PACIFIC NEAR 35N/132W...MOVING SEWD TOWARD THE CNTRL CA COAST. 00Z MODEL GUIDANCE SUGGESTS STRONG UPPER JET...APPROACHING 100KT...WILL MOVE INTO SRN CA DURING THE LATE AFTERNOON/EVENING WITH FOCUSED DIVERGENCE ALOFT EXPECTED TO SPREAD ACROSS THE SAN JOAQUIN VALLEY. STRONG ASCENT WILL UNDOUBTEDLY AID MID-HIGH LEVEL MOISTENING WHICH WILL LIMIT BOUNDARY LAYER HEATING...ESPECIALLY IN REGIONS OF PRECIPITATION. ALTHOUGH HEATING SHOULD BE LIMITED...FORECAST SHEAR PROFILES ARE QUITE STRONG...WITH VEERING FLOW THROUGH A DEEP LAYER EXPECTED TO SUPPORT STORM ROTATION WITH STRONGER UPDRAFTS. IT APPEARS SUFFICIENT INSTABILITY...ROUGHLY 500 J/KG...WILL DEVELOP FOR THUNDERSTORM DEVELOPMENT AND SUPERCELL STRUCTURES MAY EVOLVE...MAINLY IN THE VALLEY. HAIL...STRONG WINDS...AND POSSIBLY ISOLATED TORNADOES MAY ACCOMPANY THE STRONGER STORMS. ...SOUTHERN FL PENINSULA... STRONG HEATING WILL PROVE INSTRUMENTAL FOR THUNDERSTORM DEVELOPMENT ACROSS THE SRN FL PENINSULA TODAY AS WEAK CONVERGENCE WILL BE NOTED ALONG SWD MOVING WIND SHIFT. WITH DEEP W-NWLY FLOW IT APPEARS SERN TIP OF THE PENINSULA WILL BE THE PRIMARY FOCUS FOR ISOLATED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING MAINLY LARGE HAIL AND GUSTY WINDS. WEAKLY FOCUSED BOUNDARY AND LIMITED COVERAGE WARRANT LOW PROBABILITIES FOR CONVECTION THAT DEVELOPS DURING THE AFTERNOON/EARLY EVENING HOURS. ...CNTRL PLAINS/MID MS VALLEY... STRENGTHENING LOW-MID LEVEL WARM ADVECTION WILL LIKELY ENHANCE ELEVATED CONVECTIVE THREAT ACROSS ERN KS/NERN OK INTO MO/AR LATE IN THE PERIOD. WEAK INSTABILITY AND COVERAGE WILL LIMIT SEVERE POTENTIAL. ..DARROW.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 12:48:29 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 08:48:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041244 SWODY1 SPC AC 041242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0742 AM CDT TUE APR 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF SRN CA... ...SRN CA... PROMINENT MID/UPPER LEVEL LOW NOW NEAR 34N/130W WILL CONTINUE APPROACHING THE SRN CA COAST TODAY AND MOVE INLAND LATER TONIGHT. SIGNIFICANT MID/UPPER LEVEL JET WILL LIKEWISE DEVELOP ACROSS FAR SRN CA DURING THE PERIOD WITH 100+ KT AT H5 NOSING ACROSS THE SRN CA COAST BY 06Z. THOUGH INSTABILITY WILL REMAIN SOMEWHAT LIMITED... COOLING ALOFT AND MODEST AFTERNOON HEATING ARE STILL FORECAST TO SUPPORT WEAK SURFACE-BASED INSTABILITY ALONG THE SRN CA COAST AND INTO THE SRN SAN JOAQUIN VALLEY THIS AFTERNOON/EVENING...WITH INSTABILITY PERSISTING AFTER DARK NEAR THE COAST WITHIN VERY COLD POCKET ALOFT. THOUGH OVERALL SEVERE THREAT APPEARS MARGINAL DUE TO LIMITED INSTABILITY...VERY STRONG SHEAR WILL SUPPORT A THREAT OF LOW TOPPED SUPERCELLS AND LINES. ALONG WITH MARGINALLY SEVERE HAIL...THIS WILL RESULT IN POSSIBILITY OF DAMAGING WINDS AND BRIEF TORNADOES. ...CENTRAL FL... SURFACE FRONT WILL STALL ACROSS CENTRAL FL TODAY AS STRONG UPPER SYSTEM LIFTS INTO THE NORTHEASTERN U.S. SOUNDINGS YESTERDAY EVENING AND THIS MORNING INDICATE RATHER STEEP LAPSE RATES REMAIN IN PLACE AHEAD OF THIS FRONT. COMBINATION OF HEATING AND WEAK SURFACE CONVERGENCE SHOULD OVERCOME CAPPING WITHIN MODERATELY UNSTABLE AIR MASS DURING THE MID/LATE AFTERNOON. THOUGH SHEAR WILL REMAIN FAIRLY WEAK /SFC-6 KM SHEAR AOB 25 KT/...STEEP LAPSE RATES AND MODERATE INSTABILITY SHOULD SUPPORT A LOW PROBABILITY THREAT OF ISOLATED LARGE HAIL/DAMAGING WINDS WITH STRONGER CORES INTO THE EARLY EVENING. CONVECTION AND ANY SEVERE THREAT WILL QUICKLY DIMINISH AFTER DARK. ...SRN KS/NRN OK INTO SWRN MO/WRN AR... SSWLY LLJ STRENGTHENS OVERNIGHT OUT OF THE SRN HIGH PLAINS AND NOSES INTO NRN OK/SRN KS AFTER 06Z. GFS AND NAM BOTH DEVELOP 40+ KT H85 JET...BUT DIFFER SLIGHTLY ON ITS LOCATION AND AREA OF SUBSEQUENT ELEVATED THUNDERSTORM DEVELOPMENT EARLY WEDNESDAY MORNING. REGARDLESS...STEEP MID LEVEL LAPSE RATES WILL RESIDE ABOVE A MOISTENING BOUNDARY LAYER WITH H85 DEW POINTS AOA 8C LATE IN THE PERIOD. FORECAST SOUNDINGS INDICATE MUCAPE APPROACHING 750 J/KG WITH 40-50 KT OF CLOUD LAYER SHEAR. THEREFORE...STORMS MAY DEVELOP MID LEVEL ROTATION AND SUPPORT MARGINALLY SEVERE HAIL EARLY WEDNESDAY MORNING. ..EVANS/LEVIT.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 16:25:48 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 12:25:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041621 SWODY1 SPC AC 041619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CDT TUE APR 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL AND SOUTHERN CALIFORNIA... ...SYNOPSIS... WHILE DEEP UPPER LOW DEVELOPS OVER NEW ENGLAND...THE STRONG COLD LOW OFF CA COAST WILL BE MOVING INLAND TONIGHT. TRANSITORY RIDGE SURFACE AND ALOFT WILL SHIFT EWD ACROSS THE PLAINS ALLOWING GULF MOISTURE TO RETURN NORTHWARD THRU THE SRN/CENTRAL PLAINS. ...CA... THE COLD AND CONVECTIVELY ACTIVE UPPER LOW OFF CA COAST WILL MOVE INLAND TONIGHT. LAPSE RATES AROUND 7C/KM AND POTENTIAL MLCAPES TO AROUND 500 J/KG COUPLED WITH LARGE SCALE ASCENT AHEAD OF THE UPPER SYSTEM SUPPORT THE POTENTIAL OF A FEW SEVERE THUNDERSTORMS DEVELOPING THIS AFTERNOON FROM THE CENTRAL CA COAST INLAND ACROSS THE SAN JOAQUIN AND SRN SACRAMENTO VALLEYS. WHILE THE FLOW IS QUITE MERIDIONAL AHEAD OF THE UPPER SYSTEM...20KTS OF SFC-1KM SHEAR IN CONCERT WITH THE BACKED BOUNDARY LAYER FLOW WILL SUPPORT POTENTIAL FOR ORGANIZED LOW TOPPED THUNDERSTORMS. SUPERCELLS WOULD ALSO BE POSSIBLE PARTICULARLY NRN SAN JOAQUIN VALLEY WWD TO COAST PROVIDED THERE IS SUFFICIENT HEATING TO REALIZE THE POTENTIAL INSTABILITY. THUS IN ADDITION TO HAIL AND LOCALIZED STRONG DAMAGING WINDS...ISOLATED FUNNELS AND TORNADOES WOULD ALSO BE EXPECTED ALONG WITH WATERSPOUTS ALONG THE CENTRAL CA COAST. OVERNIGHT SHEAR PROFILES AND LAPSE RATES IMPROVE CONSIDERABLY SWD INTO THE LA BASIN AS 130KT UPPER JET MAX MOVES ONSHORE SRN CA AFTER 06Z. WHILE MLCAPES WILL GENERALLY BE LESS THAN 300 J/KG...TERRAIN INDUCED BACKING WIND PROFILES AND STRONG ASCENT WITH PASSAGE OF VIGOROUS UPPER TROUGH...LOW TOPPED SUPERCELLS ARE CERTAINLY A POSSIBILITY. IN ADDITION TO BRIEF DAMAGING WINDS/HAIL...ISOLATED TORNADOES/WATERSPOUTS WOULD ALSO BE A POSSIBILITY AT LEAST AS FAR S AS ORANGE COUNTY. ...CENTRAL FL... WILL MAINTAIN A LOW PROBABILITY OF THUNDERSTORMS AHEAD OF THE FRONTAL ZONE MOVING SLOWLY SWD THRU CENTRAL FL. MOST MODEL GUIDANCE INDICATE THAT THE STRONG HEATING S OF FRONT ALONG WITH AVAILABLE MOISTURE WILL BE SUFFICIENT TO OVERCOME THE CURRENT CINH WITH A COUPLE OF STRONG/SEVERE STORMS BY MID AFTERNOON. WITH LAPSE RATES AROUND 7C/KM AND MLCAPES AHEAD OF FRONT TO 1500 J/KG ISOLATED LARGE HAIL/DOWNBURST WINDS ARE POSSIBLE WITH THESE STORMS UNTIL AROUND SUNSET. ...SRN KS/NRN OK INTO SWRN MO/WRN AR... WITH THE LOW LEVEL JET STRENGTHENING TONIGHT ACROSS SRN PLAINS...ELEVATED MOISTURE AND INSTABILITY WILL SPREAD NEWD TOWARD LOWER MO VALLEY. STEEP MID LEVEL LAPSE RATES COUPLED WITH RETURNING GULF MOISTURE LEAD TO POTENTIAL OF ELEVATED CAPES TO 750 J/KG. IN ADDITION FORECAST SOUNDINGS 40-50 KT OF CLOUD LAYER SHEAR WOULD LEAD TO MID LEVEL ROTATION IN THUNDERSTORMS THAT DEVELOP IN THE WARM ADVECTION REGIME. LARGE HAIL WOULD BE POSSIBLE ASSOCIATED WITH ANY OF THESE STORMS...WHICH WOULD MOST LIKELY OCCUR AFTER 06Z. ..HALES/TAYLOR.. 04/04/2006  From SwoDy1 at goshenarc.org Tue Apr 4 19:58:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 15:58:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041955 SWODY1 SPC AC 041953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT TUE APR 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN CA... ...SYNOPSIS... HIGHLY AMPLIFIED UPPER AIR PATTERN WILL CONTINUE TO FEATURE DEEP LOWS OVER ERN GREAT LAKES...AND MOVING INLAND CA COAST. SFC FRONTAL ZONE ASSOCIATED WITH NERN STATES LOW IS ANALYZED ACROSS N-CENTRAL FL...WWD OVER NRN GULF OF MEXICO...TO S-CENTRAL TX. THIS FRONT SHOULD DECELERATE OVER CENTRAL FL THIS AFTERNOON/EVENING...WHILE BECOMING MORE DIFFUSE AND RETURNING NWD ACROSS S-CENTRAL/SW TX. PACIFIC COLD FRONT IS EVIDENT IN VIS IMAGERY ATTM FROM AROUND 27N125W NEWD TO NEAR 32N121W...THEN NWD ACROSS COASTAL AREAS OF SAN LUIS OBISPO COUNTY. THIS FRONT SHOULD MOVE EWD ACROSS MOST OF CENTRAL/SRN CA THIS AFTERNOON...AND INTO NV/AZ OVERNIGHT. ...CA... SEVERE POTENTIAL IS EXPECTED TO INCREASE THROUGH LATE AFTERNOON OVER PORTIONS SAN JOAQUIN/SRN SAC VALLEYS...ALONG/AHEAD OF SFC COLD FRONT. BREAKS IN CLOUD COVER ARE ALLOWING DIABATIC HEATING TO WEAKEN CINH FURTHER...COMBINING WITH COOLING TEMPS ALOFT TO STEEPEN LOW-MIDDLE LEVEL LAPSE RATES. THOUGH FLOW ALOFT REMAINS QUITE MERIDIONAL...OROGRAPHICALLY FORCED BACKING OF SFC FLOW IN VALLEY WILL ENHANCE DEEP-LAYER VERTICAL SHEAR. THIS SUPPORTS MAINLY LINEAR MODES WITH ENHANCED STORM-RELATIVE INFLOW AT SFC. EMBEDDED/LOW-TOPPED SUPERCELLS AND BOW ECHOES ARE POSSIBLE. REF WW 149 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST DETAILS. SEVERE THREAT IS EXPECTED TO SHIFT SWD OVERNIGHT AS STRONG SHORTWAVE TROUGH MOVES TROUGH BASE OF LARGER SYNOPTIC SYSTEM...GREATLY ENHANCING GRADIENT FLOW ALOFT AND STRENGTHENING LOW-MIDDLE LEVEL SHEAR PROFILES. ALTHOUGH TIME OF DAY WILL NOT BE FAVORABLE INLAND WITH RESPECT TO ABSOLUTE SFC HEATING...SFC-BASED BUOYANCY ACTUALLY SHOULD INCREASE THIS EVENING AND MUCH OF TONIGHT OVER REGION CONTAINING COASTAL SRN CA -- LA BASIN...SBA AREA AND CHANNEL ISLANDS. THIS SHOULD OCCUR AMIDST STRONG DIFFERENTIAL THERMAL ADVECTION WITH HEIGHT...WHERE COOLING OCCURS AT A FASTER RATE ALOFT THAN IN BOUNDARY LAYER. FCST VERTICAL SHEAR PROFILES SUGGEST LOW-TOPPED SUPERCELLS OR SMALL BOWS WITH HAIL...STRONG/DAMAGING WIND AND SOME TORNADO POTENTIAL. ...CENTRAL FL... AIRMASS CONTINUES TO DESTABILIZE ACROSS PORTIONS CENTRAL FL...WHERE SFC HEATING ALREADY HAS BOOSTED MLCAPES INTO 1500-2000 J/KG RANGE. VIS IMAGERY SHOWS TCU OVER MUCH OF CENTRAL FL INVOF FRONTAL ZONE...AND ALONG E COAST SEA BREEZE FRONT. ALTHOUGH STRONGEST MIDLEVEL FLOW WILL REMAIN N OF AREA...EFFECTIVE SHEARS 35-45 KT INVOF FRONT AND SEA BREEZE BOUNDARY INDICATE POTENTIAL FOR SOME TSTMS TO BECOME ORGANIZED WITH ISOLATED HAIL AND STRONG/DAMAGING GUSTS POSSIBLE. REF SPC MESOSCALE DISCUSSION 427 FOR MORE DETAILS ON NEAR-TERM THREAT. ACTIVITY SHOULD WEAKEN BY EARLY EVENING WITH LOSS OF SFC HEATING. ...E-CENTRAL PLAINS...WRN OZARKS... WIDELY SCATTERED TSTMS IN CLUSTERS ARE EXPECTED OVERNIGHT -- PRIMARILY AFTER 5/06Z...AS ELEVATED MOIST ADVECTION AND ISENTROPIC ASCENT RESULT IN PARCELS REACHING LFC. EXPECT FAVORABLE SHEAR FOR ORGANIZED ACTIVITY THROUGH DEPTH OF CONVECTIVE COLUMN...WITH ELEVATED MUCAPES INCREASING TO AROUND 400-700 J/KG. ISOLATED HAIL NEAR SEVERE LEVELS MAY OCCUR FROM MOST VIGOROUS CELLS. ..EDWARDS.. 04/04/2006  From SwoDy1 at goshenarc.org Wed Apr 5 00:53:02 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 04 Apr 2006 20:53:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050050 SWODY1 SPC AC 050049 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 PM CDT TUE APR 04 2006 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CA... ...CA/GREAT BASIN... LARGE SCALE UPPER DIFFLUENCE HAS DEVELOPED AHEAD OF UPPER TROUGH INTO THE GREAT BASIN AS UPPER SPEED MAX APPROACHES SRN CA/NRN BAJA PENINSULA. THIS HAS AIDED WIDESPREAD CLOUDINESS AND PRECIPITATION ACROSS MUCH OF NRN/CNTRL CA...NEWD INTO NV WHERE BOUNDARY LAYER HEATING IS STRONGER AND DEEP CONVECTION IS SOMEWHAT MORE SCATTERED. GREATEST CONCENTRATION OF THUNDERSTORMS OVER THE NEXT FEW HOURS MAY ACTUALLY BE INLAND FROM CNTRL NV INTO SCNTRL ID...ESPECIALLY GIVEN THE PARTIAL SUNSHINE THAT PERSISTS ACROSS THIS REGION. SAN JOAQUIN VALLEY WILL HOWEVER REMAIN FAVORABLE FOR RENEWED THUNDERSTORM DEVELOPMENT AS UPPER TROUGH MOVES TOWARD THE COAST. EXIT REGION OF STRONG SPEED MAX WILL AID ASCENT ACROSS THIS REGION WHERE SHEAR PROFILES REMAIN SUPPORTIVE OF ROTATING UPDRAFTS. THE MAIN IMPEDIMENT FOR WIDESPREAD ROBUST CONVECTION IS THE ABSENCE OF SIGNIFICANT INSTABILITY. EVEN SO STRENGTH OF UPPER TROUGH CERTAINLY SUPPORTS THE POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WELL INTO THE EVENING HOURS...WITH LARGE HAIL THE MOST LIKELY SEVERE THREAT. ...SRN PLAINS... SWLY TRAJECTORIES ACROSS WEST TX INTO THE SRN PLAINS IS SERVING TO MOISTEN THE 750-800MB LAYER ACROSS CNTRL OK THIS EVENING. 00Z SOUNDING FROM OUN SUGGESTS CONVECTIVE POTENTIAL MAY NOT BE THAT MANY HOURS OFF AS WARM ADVECTION INCREASES OVER THE NEXT 3-6 HOURS. ELEVATED INSTABILITY SHOULD PROVE TOO WEAK TO WARRANT ANY MEANINGFUL THREAT OF LARGE HAIL. ..DARROW.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 05:52:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 01:52:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050549 SWODY1 SPC AC 050547 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1247 AM CDT WED APR 05 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL PLAINS... ...SOUTH DAKOTA/NEBRASKA... STRONG HEIGHT FALLS WILL SPREAD ACROSS THE CNTRL/SRN ROCKIES WEDNESDAY...APPROACHING 150M IN 12HR...BEFORE UPPER LOW EJECTS INTO ERN CO BY THE END OF THE PERIOD. THIS FEATURE WILL FORCE UPPER RIDGE INTO THE MS VALLEY REGION AND ASSOCIATED ISENTROPIC ELEVATED CONVECTIVE POTENTIAL INTO PORTIONS OF MO AND AR. WELL NW OF THIS ACTIVITY...CONVECTION SHOULD DEVELOP AHEAD OF STRONG DYNAMIC FRONT FROM WY...ARCING SWD INTO NWRN AZ. THIS ACTIVITY SHOULD SPREAD NEWD WITHIN STEEP LAPSE RATE ENVIRONMENT TOWARD THE CENTRAL HIGH PLAINS WHERE STRENGTHENING LOW LEVEL WARM ADVECTION AND A RECOVERING/MOISTENING BOUNDARY LAYER WILL ENHANCE CONVECTION AFTER DARK. LATEST THINKING IS UPPER RIDGE AND ASSOCIATED CAP WILL PREVENT THUNDERSTORM DEVELOPMENT ACROSS THE CNTRL HIGH PLAINS DURING THE AFTERNOON HOURS. HOWEVER...LATE IN THE AFTERNOON THUNDERSTORMS WILL EJECT NEWD ACROSS WY INTO WRN SD/NEB PANHANDLE WHERE SHEAR/THERMODYNAMIC PROFILES WILL BECOME MORE SUPPORTIVE OF ORGANIZED UPDRAFTS. ACTIVITY SHOULD QUICKLY BECOME ELEVATED BUT OBTAIN SUFFICIENT STRENGTH WITHIN MODEST CAPE ENVIRONMENT FOR HAIL PRODUCTION AND POSSIBLY A FEW GUSTY WIND REPORTS. ADDITIONAL ACTIVITY MAY DEVELOP DURING THE OVERNIGHT HOURS AS EXIT REGION OF UPPER JET SHIFTS EAST INTO THE HIGH PLAINS. ...WEST TX... DRY LINE WILL BECOME A BIT MORE FOCUSED AS IT MIXES EAST ACROSS WEST TX LATER THIS AFTERNOON. IT APPEARS STRONG HEATING WILL ALLOW SFC TEMPERATURES TO WARM TO NEAR 90 F WHICH WILL CREATE NEAR DRY ADIABATIC LAPSE RATES ALONG WRN EDGE OF INCREASINGLY MOIST BOUNDARY LAYER. ISOLATED THUNDERSTORMS COULD DEVELOP ALONG DRY LINE SHORTLY AFTER PEAK HEATING. IF SO...GUSTY WINDS OR SOME HAIL MAY ACCOMPANY SHORT-LIVED THUNDERSTORMS. LOSS OF HEATING WILL RESULT IN QUICK DEMISE OF ANY UPDRAFTS. ..DARROW.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 12:44:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 08:44:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051242 SWODY1 SPC AC 051240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT WED APR 05 2006 VALID 051300Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SD AND NEB INTO FAR NWRN IA... ...NRN PLAINS... LOW LEVEL MOISTURE WILL CONTINUE INCREASING ACROSS THE CENTRAL PLAINS TODAY AND TONIGHT AS SLY LLJ INTENSIFIES AHEAD OF POTENT SYSTEM NOW MOVING ACROSS THE WRN U.S. H85 DEW POINTS ARE FORECAST TO INCREASE INTO THE 8C-12C RANGE WITH AXIS OF MAXIMUM VALUES EXTENDING FROM THE LOWER MO RIVER VALLEY NWWD INTO CENTRAL/WRN SD BY LATE TONIGHT. LOW PRESSURE FROM THE SURFACE THRU H85 WILL DEVELOP EWD INTO WRN NEB/WRN SD LATER TONIGHT...WITH INCREASING CONVERGENCE AND LARGE SCALE ASCENT UNDER STRONG UPPER DIFFLUENCE SUPPORTING WIDESPREAD ELEVATED THUNDERSTORMS BEGINNING LATE THIS EVENING. DIURNAL DEVELOPMENT WILL LIKELY OCCUR OVER THE ERN WY MOUNTAINS AND THE BLACK HILLS...WITH AN ISOLATED THREAT OF LARGE HAIL/DAMAGING WINDS EWD TOWARDS THE CENTRAL HIGH PLAINS. HOWEVER...PRIMARY SEVERE THREAT IS EXPECTED TO OVERSPREAD SD/NRN NEB AFTER DARK. FORECAST SOUNDINGS INDICATE MUCAPE FROM 1000-1500 J/KG WITH 40-45 KT EFFECTIVE SHEAR...SUGGESTING ELEVATED SUPERCELLS WITHIN BROADER MCS. LARGE HAIL WILL BE PRIMARY SEVERE THREAT...THOUGH ISOLATED DAMAGING WINDS MAY OCCUR. ...WEST TX... DRY LINE WILL BECOME BETTER DEFINED TODAY AS BOUNDARY LAYER MOISTURE DEEPENS AND OVERSPREADS MUCH OF THE CENTRAL TX/OK AND STRONG HEATING/MIXING OCCURS OVER FAR WEST TX. FORECAST HIGHS APPROACHING 90F OVER THE WEST TX PLAINS AND SURFACE CONVERGENCE MAY OVERCOME WHAT IS INITIALLY STRONG CAPPING LATER TODAY. OTHER ISOLATED STORMS MAY FORM OVER HIGHER TERRAIN OF SWRN TX/FAR SERN NM. 4KM WRF-NMM IS MOST AGGRESSIVE IN DEVELOPING DEEP MOIST CONVECTION OVER FAR SWRN TX INTO THE LOW ROLLING PLAINS...THOUGH 06Z NAM BRIEFLY CONVECTS OVER THIS SMALL AREA BETWEEN 00-03Z. SHOULD A STORM INITIATE...STRONG INSTABILITY...VERY STEEP LAPSE RATES AND 40-50 KT OF DEEP LAYER SHEAR WOULD SUPPORT STRONG/DAMAGING GUSTS AND LARGE HAIL FROM HIGH-BASED STORMS THROUGH A FEW HOURS AFTER SUNSET. POTENTIAL APPEARS TOO CONDITIONAL ATTM TO WARRANT MORE THAN LOW SEVERE PROBABILITIES. ..EVANS/LEVIT.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 16:16:00 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 12:16:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051614 SWODY1 SPC AC 051612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT WED APR 05 2006 VALID 051630Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN UT/WRN CO NWD ACROSS WY INTO SERN MT AND THEN EWD ACROSS PARTS OF NEB/SD... ...SYNOPSIS... STRONG/COLD UPPER SYSTEM CURRENTLY MOVING INLAND SWRN U.S. WILL BE OVER CENTRAL/SRN ROCKIES BY LATER TONIGHT. DEEPENING SURFACE LOW NWRN UT WITH A STRONG COLD FRONT EXTENDING SWD THRU CENTRAL AZ AT 15Z WILL FOCUS DEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS TODAY. LOW WILL CONTINUE DEEPENING NEWD INTO WRN WY THIS AFTERNOON AND EVENING WHILE A NEW LOW DEVELOPS LEE OF CENTRAL ROCKIES AND MOVES INTO WRN NEB LATER TONIGHT. THE STRONG COLD FRONT WILL DRIVE NEWD ACROSS WY/WRN CO INTO WRN NM THIS AFTERNOON EMERGING INTO HIGH PLAINS LATER TONIGHT. ...CENTRAL AND NRN ROCKIES... WHILE ACTUAL INSTABILITY WILL BE TYPICALLY WEAK DUE TO LIMITED SURFACE MOISTURE THIS AREA AHEAD OF STRONG COLD FRONT OTHER PARAMETERS EXPECTED TO BE SUFFICIENT TO SUPPORT A THREAT OF SEVERE CONVECTIVE WINDS TO UPGRADE THIS AREA TO A SLIGHT RISK. THE COMBINATION OF NEAR ADIABATIC LAPSE RATES ...EXIT REGION OF A VERY STRONG UPPER JET MAX MOVING INTO 4-CORNERS AREA THIS AFTERNOON AND INTENSE FRONTAL LIFT WILL GENERATE THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT THIS AFTERNOON AS IT MOVES INTO WRN WY/CO. COMBINATION OF STRONG WINDS ALOFT AND CONVECTIVE CONTRIBUTION EXPECTED TO GENERATE POTENTIAL DAMAGING WINDS. THIS ACTIVITY WILL MOVE NEWD ACROSS THE CONTINENTAL DIVIDE BY THIS EVENING PRIOR TO SOME WEAKENING LEE SLOPES. FURTHER N INTO SERN MT...INCREASING ELY/SELY LOW LEVEL FLOW AND A LITTLE GREATER MOISTURE AHEAD OF DEEPENING SURFACE LOW AND FRONT...MLCAPES COULD CLIMB TO NEAR 1000 J/KG. VEERING HODOGRAPHS INCREASE POTENTIAL OF ROTATING STORMS DEVELOPING N AND E OF BIG HORNS WITH PRIMARY THREAT OF LARGE HAIL. WIND THREAT WOULD INCREASE INTO THIS AREA DURING THE EVENING AS THE STRONG FRONT APPROACHES FROM THE SW. ...NRN AND CENTRAL PLAINS... GULF MOISTURE CONTINUES TO FEED RAPIDLY NWD THRU THE FORECAST PERIOD WITH SUFFICIENT CINH TO LIMIT THREAT OF CONVECTIVE INITIATION UNTIL AFTER 00Z. WARM ADVECTION AND UPWARD MOTION AS THE STRONG DIFFLUENT JET MOVES INTO THE CENTRAL HIGH PLAINS LATER TONIGHT SHOULD AID IN DEVELOPMENT OF PRIMARILY ELEVATED THUNDERSTORMS EWD ACROSS SD/NEB. WITH ELEVATED CAPES IN EXCESS OF 2000 J/KG AND STEEP MID LEVEL LAPSE RATES SUPERCELLS ARE POSSIBLE. THIS WILL ENHANCE PRIMARILY LARGE HAIL THREAT OVERNIGHT. ...SWRN TX... STRONG SURFACE HEATING WILL WEAKEN CAP ON WESTERN EDGE OF MOISTURE LATER THIS AFTERNOON. A FEW THUNDERSTORMS ARE LIKELY TO DEVELOP OFF HIGHER TERRAIN OF SWRN TX. WITH DEEP LAYER SHEAR OF 40-50 KT AND STEEP LAPSE RATES ANY STORM THAT CAN DEVELOP WOULD BE POTENTIALLY SEVERE WITH PRIMARILY A LARGE HAIL POTENTIAL. THIS THREAT COULD CONTINUE AFTER DARK AS LOW LEVEL JET INCREASES TO 30-40 KTS ACROSS WRN TX. ..HALES/TAYLOR.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 19:40:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 15:40:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051937 SWODY1 SPC AC 051935 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0235 PM CDT WED APR 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL AND NRN ROCKIES INTO PARTS OF NEB AND SD... ...CNTRL AND NRN ROCKIES MOUNTAIN AREA... SCATTERED STORMS SHOULD CONTINUE DEVELOPING OVER THE CNTRL ROCKIES AREA THIS AFTERNOON AND SUBSEQUENTLY SPREAD NWD WITHIN ZONE OF ASCENT ASSOCIATED WITH NEWD MOVING VORT MAX. SURFACE DEWPOINTS ARE ONLY IN THE 30S...BUT COLD MID LEVEL TEMPERATURES AND SURFACE HEATING ARE CONTRIBUTING TO MARGINAL INSTABILITY. TEMPERATURES HAVE WARMED INTO THE 60S AND 70S RESULTING IN LARGE TEMPERATURE DEWPOINT SPREADS AND DRY BOUNDARY LAYERS. THIS WILL ENHANCE THE POTENTIAL FOR ISOLATED SEVERE WIND GUSTS WITH THE STRONGER STORMS...ESPECIALLY IF STORMS CAN BECOME ORGANIZED AS LINE SEGMENTS ALONG THE EWD ADVANCING FRONTAL ZONE EXTENDING THROUGH ERN UT. STRONG VERTICAL SHEAR PROFILES MAY ALSO CONTRIBUTE TO ROTATION IN SOME STORMS. THIS AND STEEP MID LEVEL LAPSE RATES SUGGEST A FEW STORMS COULD PRODUCE HAIL. ...NRN PLAINS... WARM FRONT WILL BECOME BETTER DEFINED OVER THE CNTRL PLAINS TONIGHT AS LEE CYCLONE DEEPENS. THE STRENGTHENING LOW LEVEL JET WILL ADVECT PARTIALLY MODIFIED GULF AIR NWD UNDERNEATH STEEP MID LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE MUCAPE. WARM ADVECTION AND LIFT ASSOCIATED WITH THE LOW LEVEL JET WILL CONTRIBUTE TO THE POTENTIAL FOR ELEVATED STORMS...PRIMARILY N OF THE WARM FRONT. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL WITH THE STRONGER STORMS. ...SRN CA... SCATTERED CONVECTION IS DEVELOPING WITHIN ZONE OF ASCENT AND COLD MID LEVEL TEMPERATURES ACCOMPANYING VORT MAX ROUNDING BASE OF UPPER TROUGH. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES SUGGEST ISOLATED STORMS MAY BE CAPABLE OF PRODUCING HAIL NEXT FEW HOURS. ...WRN AND SWRN TX... STRONG SURFACE HEATING AND MIXING ON WRN EDGE OF THE RICHER LOW LEVEL MOISTURE MAY WEAKEN CAP SUFFICIENTLY FOR ISOLATED HIGH BASED STORMS TO DEVELOP OVER PORTIONS OF WRN AND SWRN TX. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION MAY CONTRIBUTE TO A THREAT FOR HAIL. HIGH BASED NATURE OF THE STORMS SUGGESTS ISOLATED STRONG WIND GUSTS MAY ALSO BE POSSIBLE THROUGH EARLY EVENING. COVERAGE IS NOT EXPECTED TO BE SUFFICIENT TO WARRANT A SLIGHT RISK. ..DIAL.. 04/05/2006  From SwoDy1 at goshenarc.org Wed Apr 5 20:15:13 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 16:15:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 052011 SWODY1 SPC AC 052010 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0310 PM CDT WED APR 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL AND NRN ROCKIES INTO PARTS OF NEB AND SD... ...CNTRL AND NRN ROCKIES MOUNTAIN AREA... SCATTERED STORMS SHOULD CONTINUE DEVELOPING OVER THE CNTRL ROCKIES AREA THIS AFTERNOON AND SUBSEQUENTLY SPREAD NWD WITHIN ZONE OF ASCENT ASSOCIATED WITH NEWD MOVING VORT MAX. SURFACE DEWPOINTS ARE ONLY IN THE 30S...BUT COLD MID LEVEL TEMPERATURES AND SURFACE HEATING ARE CONTRIBUTING TO MARGINAL INSTABILITY. TEMPERATURES HAVE WARMED INTO THE 60S AND 70S RESULTING IN LARGE TEMPERATURE DEWPOINT SPREADS AND DRY BOUNDARY LAYERS. THIS WILL ENHANCE THE POTENTIAL FOR ISOLATED SEVERE WIND GUSTS WITH THE STRONGER STORMS...ESPECIALLY IF STORMS CAN BECOME ORGANIZED AS LINE SEGMENTS ALONG THE EWD ADVANCING FRONTAL ZONE EXTENDING THROUGH ERN UT. STRONG VERTICAL SHEAR PROFILES MAY ALSO CONTRIBUTE TO ROTATION IN SOME STORMS. THIS AND STEEP MID LEVEL LAPSE RATES SUGGEST A FEW STORMS COULD PRODUCE HAIL. ...NRN PLAINS... WARM FRONT WILL BECOME BETTER DEFINED OVER THE CNTRL PLAINS TONIGHT AS LEE CYCLONE DEEPENS. THE STRENGTHENING LOW LEVEL JET WILL ADVECT PARTIALLY MODIFIED GULF AIR NWD UNDERNEATH STEEP MID LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE MUCAPE. WARM ADVECTION AND LIFT ASSOCIATED WITH THE LOW LEVEL JET WILL CONTRIBUTE TO THE POTENTIAL FOR ELEVATED STORMS...PRIMARILY N OF THE WARM FRONT. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL WITH THE STRONGER STORMS. ...SRN CA... SCATTERED CONVECTION IS DEVELOPING WITHIN ZONE OF ASCENT AND COLD MID LEVEL TEMPERATURES ACCOMPANYING VORT MAX ROUNDING BASE OF UPPER TROUGH. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES SUGGEST ISOLATED STORMS MAY BE CAPABLE OF PRODUCING HAIL NEXT FEW HOURS. ...WRN AND SWRN TX... STRONG SURFACE HEATING AND MIXING ON WRN EDGE OF THE RICHER LOW LEVEL MOISTURE MAY WEAKEN CAP SUFFICIENTLY FOR ISOLATED HIGH BASED STORMS TO DEVELOP OVER PORTIONS OF WRN AND SWRN TX. THERMODYNAMIC PROFILES WITH STEEP LAPSE RATES AND SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION MAY CONTRIBUTE TO A THREAT FOR HAIL. HIGH BASED NATURE OF THE STORMS SUGGESTS ISOLATED STRONG WIND GUSTS MAY ALSO BE POSSIBLE THROUGH EARLY EVENING. COVERAGE IS NOT EXPECTED TO BE SUFFICIENT TO WARRANT A SLIGHT RISK. ..DIAL.. 04/05/2006  From SwoDy1 at goshenarc.org Thu Apr 6 01:04:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 05 Apr 2006 21:04:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060102 SWODY1 SPC AC 060100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT WED APR 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM PARTS OF THE NRN HIGH PLAINS INTO THE MID/LOWER MISSOURI VALLEY.... CLOSED LOW EMBEDDED WITHIN LARGE-SCALE WESTERN U.S. UPPER TROUGH CURRENTLY APPEARS CENTERED OVER THE NORTH CENTRAL GREAT BASIN... WITH INITIAL IMPULSE ROTATING AROUND ITS SOUTHERN/EASTERN PERIPHERY...INTO THE NORTH CENTRAL ROCKIES. FORCING WITH THIS FEATURE HAS CONTRIBUTED TO THE DEVELOPMENT OF A DEEP SURFACE LOW...WHICH HAS SHIFTED ACROSS NORTH CENTRAL WYOMING INTO SOUTH CENTRAL/SOUTHEASTERN MONTANA. HOWEVER...IT STILL APPEARS THAT PRIMARY SURFACE LOW WILL EVENTUALLY FORM ACROSS NORTHEAST COLORADO INTO WESTERN NEBRASKA OVERNIGHT. THIS IS PROGGED TO OCCUR AS A MORE SIGNIFICANT IMPULSE ACCELERATES EASTWARD OUT OF THE LOWER COLORADO VALLEY. STRONG MID-LEVEL COOLING WILL ACCOMPANY THIS FEATURE INTO THE SOUTH CENTRAL ROCKIES LATE TONIGHT...AND MID-LEVEL CLOSED LOW WILL BEGIN TO REDEVELOP SOUTHEASTWARD INTO THE CENTRAL ROCKIES/HIGH PLAINS BY 12Z THURSDAY...OR SHORTLY THEREAFTER. ...SOUTHEAST MONTANA... DESPITE VERY LIMITED LOW-LEVEL MOISTURE...STEEP LOW/MID-LEVEL LAPSE RATES HAVE DEVELOPED IN WARM SECTOR OF DEEP SURFACE LOW. CAPE MAY BE WEAK...BUT THERMODYNAMIC PROFILES WITH A DEEPLY MIXED BOUNDARY LAYER WILL BE SUPPORTIVE OF PRIMARILY DAMAGING WIND GUSTS THROUGH EARLY EVENING. SHEAR PROFILES ARE SUFFICIENT FOR UPDRAFT ROTATION...AND AN ISOLATED SUPERCELL MAY STILL DEVELOP BEFORE NIGHTFALL BETWEEN BILLINGS AND MILES CITY...WHICH WOULD ENHANCE RISK FOR STRONG WIND GUSTS/HAIL...PERHAPS A BRIEF TORNADO. ...MID/LOWER MISSOURI VALLEY... SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT IS ALREADY UNDERWAY ACROSS PARTS OF THE LOWER MISSOURI VALLEY...WHERE SOUTHERLY LOW-LEVEL JET IS ENHANCING WARM ADVECTION...NORTH OF CAPPING MID-LEVEL RIDGE. ACTIVITY IS BASED IN ELEVATED MOIST LAYER WITH MOST UNSTABLE CAPE INCREASING AS HIGH AS 1500 J/KG...WHICH WILL SUPPORT AT LEAST MARGINALLY SEVERE HAIL IN FAVORABLY SHEARED ENVIRONMENT. COVERAGE OF STORMS SHOULD CONTINUE TO INCREASE OVERNIGHT. ...WESTERN SOUTH DAKOTA/NORTHERN NEBRASKA... EXIT REGION OF STRONG MID-LEVEL JET MAY BEGIN TO OVERSPREAD WARM FRONTAL ZONE TOWARD 09-12Z. THIS SHOULD WEAKEN INHIBITION ALONG BOUNDARY...WHICH WILL BECOME FOCUS FOR THUNDERSTORM ACTIVITY. CAPE FOR MOIST PARCELS BASED ABOVE FRONTAL INVERSION IS EXPECTED UP TO AROUND 1500 J/KG...WHICH WILL CONTRIBUTE TO RISK FOR SEVERE STORMS...MAINLY WITH LARGE HAIL. ..KERR.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 06:04:36 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 02:04:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060601 SWODY1 SPC AC 060600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT THU APR 06 2006 VALID 061200Z - 071200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTN AND EARLY EVE ACROSS PARTS OF ERN NEB/ERN KS/PARTS OF ERN OK/WRN IA/WRN MO AND NW AR...WHERE WIDESPREAD SEVERE THUNDERSTORMS APPEAR POSSIBLE...INCLUDING RISK FOR VERY LARGE HAIL/DAMAGING WINDS AND A FEW TORNADOES.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA ACROSS MUCH OF THE EAST CENTRAL PLAINS INTO MIDDLE MS VLY.... COLD SOUTHERN BRANCH TROUGH OVER THE INTERMOUNTAIN WEST IS OUT OF PHASE WITH THE NORTHERN STREAM...AND NEXT UPSTREAM IMPULSE IS PROGGED TO REMAIN WELL WEST OF THE PACIFIC COAST THROUGH AT LEAST 12Z FRIDAY. HOWEVER...THE SYSTEM IS SLOWLY PROGRESSING EASTWARD INTO THE ROCKIES...TO THE SOUTH OF A NORTHERN BRANCH RIDGE...WHICH WILL PERSIST TO THE LEE OF THE CANADIAN ROCKIES. THOUGH THERE IS SOME CONCERN ABOUT THE RATE OF PROGRESSION OF THE TROUGH TO THE EAST OF THE U.S. ROCKIES...MODELS CONTINUE TO INDICATE THAT EMBEDDED CIRCULATION WILL REFORM SOUTHEASTWARD INTO EASTERN COLORADO EARLY TODAY...THEN INTO THE CENTRAL PLAINS BY THE END OF THE FORECAST PERIOD. THIS IS PROGGED TO OCCUR AS A STRONG MID-LEVEL IMPULSE/JET STREAK ROTATES AROUND ITS SOUTHERN/EASTERN PERIPHERY...ACROSS THE CENTRAL PLAINS DURING THE DAY TODAY...THROUGH THE MID/LOWER MISSOURI VALLEY BY LATE TONIGHT. IN RESPONSE TO EVOLVING UPPER FLOW PATTERN...PRIMARY SURFACE CYCLONE IS PROGGED TO FORM OVER CENTRAL NEBRASKA...THEN SLOWLY DEEPEN THROUGH THE DAY. SYSTEM IS PROGGED TO BECOME OCCLUDED LATE THIS AFTERNOON AND TONIGHT...BUT REMAIN OVER THE NORTH CENTRAL PLAINS AS WEAK TRIPLE POINT WAVE SHIFTS EASTWARD TOWARD THE SOUTHERN GREAT LAKES REGION. ...CENTRAL STATES... CONSIDERABLE CLOUD COVER AND SCATTERED CONVECTIVE DEVELOPMENT SEEM LIKELY TO IMPEDE BOUNDARY LAYER DESTABILIZATION THROUGH MUCH OF THE OZARKS INTO THE MIDDLE MISSISSIPPI VALLEY TODAY. HOWEVER... MID-LEVEL DRY SLOT IS EXPECTED TO ALLOW INSOLATION IN AT LEAST A NARROW CORRIDOR AHEAD OF COLD FRONT/DRY LINE TRAILING SOUTHWARD FROM SURFACE LOW CENTER. BY MID DAY...BOUNDARY IS EXPECTED ROUGHLY WEST OF GRAND ISLAND NEB/MANHATTAN AND WICHITA KS INTO CENTRAL OKLAHOMA...PRECEDED BY TONGUE OF 60F+ SURFACE DEW POINTS. AS MID-LEVEL THERMAL TROUGH TAKES ON INCREASING NEGATIVE TILT...MID-LEVEL CAPPING IS EXPECTED TO BE BROKEN...PERHAPS AS EARLY AS THE 18-21Z TIME FRAME. RAPID DEVELOPMENT OF A BROKEN SQUALL LINE APPEARS LIKELY IN AN ENVIRONMENT WITH STEEP LAPSE RATES AND MODERATELY STRONG CAPE OF 1500-2000 J/KG...AND SHEAR IN EXIT REGION OF 90+ KT 500 MB JET NOSING ACROSS OKLAHOMA WILL BE SUFFICIENT FOR SUPERCELLS. VERY LARGE HAIL/DAMAGING WIND GUSTS WILL LIKELY ACCOMPANY STRONGEST CONVECTION. TORNADO POTENTIAL IS MORE UNCERTAIN...MAINLY ACROSS EASTERN KANSAS INTO WESTERN MISSOURI...WHERE DEEP LAYER SOUTHERLY FLOW WILL EXIST. FARTHER TO THE NORTH...TO THE EAST OF SURFACE LOW CENTER...EASTERLY LOW-LEVEL FLOW WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVING LOW-LEVEL HODOGRAPHS BENEATH MODERATE STRONG SOUTHERLY UPPER FLOW. THIS SHOULD ENHANCE POTENTIAL FOR TORNADOES ACROSS PARTS OF EASTERN NEBRASKA INTO WESTERN IOWA...PERHAPS EXTREME NORTHWEST MISSOURI. A SECONDARY AREA OF SIGNIFICANT CONVECTIVE DEVELOPMENT APPEARS POSSIBLE WHERE MID-LEVEL JET STREAK NOSES OVER DRY LINE ACROSS NORTHEAST OKLAHOMA. THIS SEEMS POSSIBLE BY 21-22Z. MODELS SUGGEST STRONG MID-LEVEL FLOW ACROSS THIS REGION WILL VEER TO A MORE WESTERLY COMPONENT...WHICH MAY FAVOR MORE DISCRETE SUPERCELL DEVELOPMENT IN ENVIRONMENT WITH CAPE AROUND 2000 J/KG. VEERING OF WINDS WITH HEIGHT BENEATH 30 TO 50 KT SOUTHERLY LOW-LEVEL JET MAY NOT BECOME STRONG...BUT SHEAR IS EXPECTED TO BE SUFFICIENT FOR TORNADIC ACTIVITY. ISOLATED STRONG TORNADOES SEEM POSSIBLE AS ACTIVITY DEVELOPS NORTHEASTWARD INTO THE OZARK PLATEAU. SEVERE THREAT MAY CONTINUE THROUGH THE EVENING INTO MUCH OF THE MIDDLE MISSISSIPPI VALLEY. HOWEVER...INTENSITY/COVERAGE OF SEVERE THREAT IS EXPECTED TO DIMINISH SIGNIFICANTLY BY LATE EVENING...AS EVOLUTION OF LARGE-SCALE PATTERN DOES NOT APPEAR LIKELY TO SUPPORT SIGNIFICANT EASTWARD DESTABILIZATION DURING THIS FORECAST PERIOD. ..KERR/CROSBIE.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 12:36:40 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 08:36:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061234 SWODY1 SPC AC 061232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0732 AM CDT THU APR 06 2006 VALID 061300Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS OVER NERN KS INTO SERN NEB AND FAR NWRN MO LATER TODAY AND THIS EVENING... ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK FROM ERN NEB/WRN IA INTO WRN MO...ERN OK AND WRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK OVER PORTIONS OF THE SRN/CENTRAL PLAINS EWD ACROSS THE MID MS RIVER VALLEY... ...SIGNIFICANT SEVERE WEATHER OUTBREAK /INCLUDING NUMEROUS TORNADIC SUPERCELLS/ IS EXPECTED TO EVOLVE ACROSS EASTERN PORTIONS OF THE CENTRAL PLAINS STATES LATER TODAY AND THIS EVENING... ...SYNOPSIS... POTENT MID/UPPER LEVEL LOW NOW OVER THE FOUR-CORNERS REGION WILL RAPIDLY EJECT NEWD INTO THE CENTRAL PLAINS TODAY...WITH 210M HEIGHT FALLS AT H5 SPREADING ACROSS ERN KS BY 00Z. SIGNIFICANT MID TO UPPER LEVEL JET MAX WILL ACCOMPANY THIS SYSTEM WITH H5 WINDS IN EXCESS OF 100 KT /115+ KT AT H25/ SHIFTING ACROSS OK. ASSOCIATED SURFACE LOW NOW TAKING SHAPE OVER CENTRAL NEB WILL DEEPEN AS IT BECOMES BETTER DEFINED NEAR THE N-CENTRAL KS/SERN NEB BORDER LATER THIS AFTERNOON. AS THIS OCCURS...VERY STRONG DRY LINE WILL MIX TO NEAR THE I-35 CORRIDOR BY 18Z AND THEN SHIFT RAPIDLY EWD INTO WRN MO/WRN AR THIS EVENING. AHEAD OF THIS...MODEST LOW LEVEL MOISTURE WILL REMAIN IN PLACE WITH AXIS OF AROUND 60F SURFACE DEW POINTS EXTENDING INTO ERN KS AND FAR SERN NEB THIS AFTERNOON. IN ADDITION...VERY STEEP LAPSE RATES /I.E. 8.5+ C/KM FROM H7-H5/ ARE ALREADY OBSERVED ACROSS THE REGION AND WILL REMAIN IN PLACE TODAY. ...ERN SD/NEB INTO KS/MO/IA... MORNING CONVECTION WITH THREAT OF ISOLATED LARGE HAIL WILL LIKELY INCREASE WITHIN BROAD UPPER DIFFLUENCE ACROSS SD AND INTO PORTIONS OF IA THIS MORNING. IN ADDITION...WITH H85 FLOW REMAINING VEERED TO SWLY OVER THE SRN PLAINS...LOW LEVEL WAA AND ASCENT AHEAD OF SUBTLE DISTURBANCE EVIDENT ON WV IMAGERY MOVING INTO SWRN OK WILL LIKELY INCREASE CLOUDS AND MOIST CONVECTION ACROSS CENTRAL OK AND INTO THE OZARKS THIS MORNING. THIS ACTIVITY WILL ALSO LIKELY REMAIN ELEVATED ABOVE STRONGLY CAPPED BOUNDARY LAYER...THOUGH CLOUD LAYER SHEAR AND STEEP LAPSE RATES COULD SUPPORT LARGE HAIL. PRIMARY SEVERE THREAT IS STILL EXPECTED TO ERUPT ALONG THE DRY LINE ALONG LEADING EDGE OF STRONG ASCENT FROM CENTRAL NEB INTO N-CENTRAL OK...POSSIBLY AS EARLY AS 18Z...AND EVOLVE INTO AN OUTBREAK OF SEVERE THUNDERSTORMS THROUGH 02-03Z ACROSS MUCH OF ERN KS AND PORTIONS OF SERN NEB/WRN MO. WARM SECTOR IS FORECAST TO BECOME MODERATELY UNSTABLE WITH MLCAPE TO 2000 J/KG INTO THE CENTRAL PLAINS. VERY STRONG SHEAR REMAINS SUPPORTIVE OF SUPERCELLS...WITH A VARIETY OF STORM MOTIONS. CELLS INTO ERN NEB WILL TEND TO DEVELOP NWD AND ROTATE NWWD TOWARDS CENTRAL NEB...WHILE DEVELOPMENT SOUTH OF THE SURFACE LOW WILL TEND TO SHIFT RAPIDLY ENEWD ACROSS ERN KS AND INTO WRN MO WHERE AIR MASS WILL LIKELY DESTABILIZE IN WAKE OF ANY EARLY DAY ACTIVITY. SOUNDINGS CONTINUE TO SUPPORT VERY LARGE AND DAMAGING HAIL WITH SOME HAIL STONES EXCEEDING 3-4 INCHES IN DIAMETER. SUPERCELLS ARE ALSO EXPECTED TO BECOME TORNADIC...ESPECIALLY INTO NERN KS/FAR SERN NEB/NWRN MO WHERE STRONG PRESSURE FALLS AND BACKED SURFACE WINDS WILL ENHANCE LOW LEVEL HELICITIES AND LCLS REMAIN MORE FAVORABLE ESE OF THE LOW CENTER. CONVECTIVE MODE/STORM-SCALE EVOLUTION STILL HARD TO DETERMINE ATTM...AS SOME OF THE ACTIVITY MAY EVOLVE INTO LEWP/BOW ECHOES...ESPECIALLY INTO THE EVENING. REGARDLESS...SUPERCELL STRUCTURES ARE EXPECTED TO REMAIN WIDESPREAD WITH ATTENDANT THREAT OF TORNADOES...SOME OF WHICH COULD BE QUITE STRONG GIVEN MAGNITUDE OF SHEAR AND STRONG SURFACE PRESSURE FALLS. STORMS ARE EXPECTED TO EVENTUALLY OUTRUN INSTABILITY NEAR THE LOWER MO/MID-MS RIVER VALLEYS AND BECOME INCREASINGLY ELEVATED NORTH OF THE WARM FRONT LATER THIS EVENING/OVERNIGHT...THOUGH LARGE HAIL POTENTIAL MAY SPREAD ACROSS THE MID MS RIVER VALLEY AND INTO THE OH RIVER VALLEY LATE TONIGHT. ...ERN OK/WRN AR INTO FAR NERN TX... SIGNIFICANT MID/UPPER LEVEL SHEAR WILL DEVELOP ACROSS THE DRY LINE INTO ERN OK/NERN TX LATER TODAY...WHERE MLCAPES SHOULD APPROACH 2500 J/KG ALONG WRN EDGE OF MID LEVEL CLOUD SHIELD NOW EXTENDING NE-SW ACROSS CENTRAL OK. CAPPING WILL BE MORE PROBLEMATIC SOUTH OF UPPER JET AND WITHIN WEAKER ASCENT THAN COMPARED TO AREAS FARTHER NORTH. HOWEVER...FORECAST SOUNDINGS CONTINUE TO INDICATE DANGEROUS COMBINATION OF LONG HODOGRAPHS AND MODERATE INSTABILITY. STORMS MAY REMAIN MORE ISOLATED ACROSS THIS REGION...THOUGH PARAMETERS REMAIN QUITE FAVORABLE FOR LONG-LIVED SUPERCELLS... INCLUDING STRONG AND DAMAGING TORNADOES...WITH STORMS THAT DO DEVELOP. THIS ACTIVITY WILL LIKELY BECOME ELEVATED DURING THE MID/LATE EVENING INTO CENTRAL AR AND SPREAD ISOLATED DAMAGING WIND/LARGE HAIL THREAT TOWARDS THE LOWER OH RIVER VALLEY LATER TONIGHT. ..EVANS/CROSBIE.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 16:31:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 12:31:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061624 SWODY1 SPC AC 061623 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 AM CDT THU APR 06 2006 VALID 061630Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR S/SE NEB...ROUGHLY THE ERN HALF OF KS...AND A SMALL PART OF WRN MO.... ...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM ERN NEB/WRN IA SWD TO ERN OK AND WRN AR.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT AND HIGH RISK AREAS...FOR MUCH OF THE CENTRAL PLAINS TO THE MID MS VALLEY.... ...SIGNIFICANT SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON/EVENING FROM SE NEB ACROSS ERN KS/WRN MO INTO ERN OK AND WRN AR... ...CENTRAL PLAINS THIS AFTERNOON INTO MO/AR TONIGHT... WITHIN A BROAD MID LEVEL LOW OVER THE CENTRAL ROCKIES...AN INTENSE MID LEVEL SHORTWAVE TROUGH IS ROTATING EWD FROM NM TOWARD OK/KS THIS AFTERNOON. A SURFACE CYCLONE NOW IN E CENTRAL NEB WILL PERSIST TODAY...WITH ADDITIONAL CYCLOGENESIS EXPECTED INVOF SW INTO CENTRAL KS IN RESPONSE TO 210 M HEIGHT FALLS AT 500 MB DURING THE AFTERNOON. THIS KS LOW SHOULD THEN ROTATE NNEWD TOWARD NEB THIS EVENING AND EVOLVE INTO A DEEP OCCLUDED SYSTEM OVERNIGHT. LOW-LEVEL MOISTURE CONTINUES TO SPREAD NWD FROM TX/LA/AR/OK NWD TO WRN MO...KS/NEB. REGIONAL 12Z SOUNDINGS REVEALED A PRONOUNCED EML ABOVE THE MOIST LAYER...WITH MEAN BOUNDARY LAYER DEWPOINTS IN THE UPPER 50S TO LOWER 60S. GIVEN THE SHALLOW BOUNDARY LAYER OBSERVED ACROSS S TX...AFTERNOON DEWPOINTS SHOULD GENERALLY REMAIN IN THE 60-62 F RANGE WITHIN THE WARM SECTOR...AS OPPOSED TO RECENT NAM FORECASTS OF MID 60S. VERY STEEP MID LEVEL LAPSE RATES...ALONG WITH AN EROSION OF THE CAP FROM BELOW BY HEATING AND FROM THE W BY ASCENT WITH THE APPROACHING WAVE...WILL SUPPORT AN INCREASING THREAT FOR CONVECTIVE INITIATION BY 18-20Z NEAR THE PACIFIC COLD FRONT AND DEVELOPING SECONDARY LOW INVOF CENTRAL KS. STORMS SHOULD EXPAND IN COVERAGE THROUGH THE AFTERNOON INTO S CENTRAL/SE NEB AND ERN KS...WITH ADDITIONAL DEVELOPMENT POSSIBLE SWD ALONG THE PACIFIC COLD FRONT IN OK TO THE E OF I-35 BY MID-LATE AFTERNOON. WITH DAYTIME HEATING...MODERATE TO STRONG INSTABILITY IS EXPECTED WITHIN THE INITIAL MID LEVEL DRY SLOT WHERE MLCAPE VALUES SHOULD REACH 1500-2000 J/KG. THE FORECAST ORIENTATION OF THE MID-UPPER FLOW RELATIVE TO THE INITIATING SURFACE BOUNDARIES...ALONG WITH THE STRONG FORCING WITH THE APPROACHING WAVE...SUGGEST THE POSSIBILITY OF MIXED MODE CONVECTION WITH BOTH SUPERCELLS AND BOWING LINE SEGMENTS ACROSS KS/NEB. AFTERNOON TEMPERATURE- DEWPOINT SPREADS MAY BE MARGINALLY LARGE FOR SIGNIFICANT TORNADOES...THOUGH FORECAST HODOGRAPHS STILL APPEAR SUPPORTIVE OF TORNADOES. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY WITH THESE STORMS. FARTHER S AND LATER THIS AFTERNOON/EVENING...PROFILES APPEAR SUPPORTIVE OF DISCRETE SUPERCELLS ACROSS ERN OK/AR/SRN MO INTO EARLY TONIGHT. TORNADOES WILL BE POSSIBLE WITH THESE STORMS...A FEW OF WHICH COULD BE STRONG...GIVEN AN INCREASE IN LOW-LEVEL SHEAR THIS EVENING AND A MORE MOIST ENVIRONMENT COMPARED TO AREAS FARTHER W AND N. ...MS AND MO VALLEYS TODAY... ELEVATED CONVECTION CONTINUES TO DEVELOP IN A SWATH FROM ERN SD TO SE IA INTO MO/IL IN A REGION OF PRONOUNCED WAA. STEEP MID LEVEL LAPSE RATES AND LIMITED ELEVATED CAPE WILL SUPPORT A THREAT FOR ISOLATED LARGE HAIL WITH THIS CONVECTION THROUGH THE AFTERNOON. FARTHER S...OTHER ELEVATED STORMS ARE FORMING ACROSS ERN OK/WRN AR INTO NE TX. LARGE HAIL WILL ALSO BE THE PRIMARY THREAT WITH THIS ACTIVITY...THOUGH DAMAGING WINDS COULD BECOME POSSIBLE AS THE BOUNDARY LAYER GRADUALLY DESTABILIZES. ..THOMPSON/TAYLOR.. 04/06/2006  From SwoDy1 at goshenarc.org Thu Apr 6 20:15:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 16:15:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062011 SWODY1 SPC AC 062009 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0309 PM CDT THU APR 06 2006 VALID 062000Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF FAR SE NEB...ERN KS...ERN OK...WRN MO AND WRN AR... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SW IA...ERN NEB...KS...ERN OK...WRN MO AND AR... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE PLAINS AND MS RIVER VALLEY... ...CNTRL AND SRN PLAINS/OZARKS... WATER VAPOR IMAGERY CURRENTLY SHOWS A VIGOROUS UPPER-LOW/TROUGH OVER THE HIGH PLAINS WITH A DRY SLOT ADVANCING EWD ACROSS ERN KS AND CNTRL OK. A 90 KT MID-LEVEL JET IS CURRENTLY EJECTING NEWD OUT OF THE BASE OF THE TROUGH SPREADING STRONG DIVERGENCE ACROSS THE CNTRL AND SRN PLAINS. THE STRONG LIFT COMBINED WITH AN AXIS OF MODERATE INSTABILITY AND WEAKENING CAP IS RESULTING IN RAPID STORM INITIATION FROM CNTRL KS EXTENDING SSEWD ACROSS ECNTRL OK. REGIONAL PROFILERS CURRENTLY SHOW STRONG VERTICAL SHEAR PROFILES WHICH ARE BEING ENHANCED BY THE EJECTING MID-LEVEL JET. IN ADDITION...MID-LEVEL LAPSE RATES ARE STEEPENING AS THE TROUGH APPROACHES FROM THE WEST. AS A RESULT...THE ENVIRONMENT APPEARS VERY FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. VERY LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS. AS THE STORMS TRACK NEWD INTO INCREASING LOW-LEVEL FLOW AND GREATER INSTABILITY...THE TORNADO THREAT WILL INCREASE. THE BEST POTENTIAL FOR STRONG TORNADOES APPEARS TO EXIST OVER NE OK...NW AR...ERN KS AND FAR WRN MO WHERE THE LOW-LEVEL SHEAR PROFILES ARE BEING ENHANCED BY A STRONG LOW-LEVEL JET. AS THE TROUGH PASSES BY LATE THIS EVENING...STORMS SHOULD ALSO DEVELOP IN FAR NE TX...SE OK AND SW AR BUT STORM COVERAGE SHOULD BE LESS DUE TO WEAKER LARGE-SCALE ASCENT IN THAT AREA. AS THE DRY SLOT SHIFTS EWD ACROSS THE REGION...STORMS WILL GRADUALLY MOVE EWD ACROSS MO AND AR. ALTHOUGH THE SEVERE THREAT SHOULD CONTINUE THROUGH MUCH OF THE NIGHT DUE TO THE VERY STRONG VERTICAL SHEAR AND FOCUSED LARGE-SCALE ASCENT...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL BY LATE TONIGHT. ...NRN AND CNTRL PLAINS/UPPER MIDWEST... STORMS ARE CURRENTLY INITIATING ACROSS FAR NRN KS ALONG THE LEADING EDGE OF ASCENT AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH. ADDITIONAL STORMS WILL INITIATE ACROSS SRN NEB WITH STORM COVERAGE INCREASING LATE THIS AFTERNOON. SFC ANALYSIS CURRENTLY SHOWS SFC DEWPOINTS IN THE 50S F ACROSS NE KS...ERN NEB AND WRN IA WITH MODERATE INSTABILITY EXTENDING AS FAR NORTH AS SERN SD. AS THE TROUGH APPROACHES LATE THIS AFTERNOON...VERTICAL SHEAR WILL CONTINUE TO INCREASE AND LAPSE RATES WILL STEEPEN FURTHER WHICH COMBINED WITH THE INSTABILITY WILL BE VERY FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. WIND DAMAGE WILL ALSO BE LIKELY WITH THE STRONGER SUPERCELLS AND SHOULD BE ENHANCED SOMEWHAT BY THE LARGE SFC TEMP-DEWPOINT SPREADS EXCEEDING 30 DEGREES F IN SOME PLACES. A FEW TORNADOES WILL ALSO BE POSSIBLE AS THE STORMS BECOME AFFECTED BY A STRENGTHENING LOW-LEVEL JET EARLY THIS EVENING. THE MODELS DEVELOP A LARGE MCS THIS EVENING ACROSS SD...ERN NEB...SRN MN AND IA WHICH SEEMS REASONABLE CONSIDERING THE AMOUNT OF LARGE-SCALE ASCENT MOVING EWD AHEAD OF THE TROUGH. THE STORMS SHOULD MOVE AND DEVELOP NEWD INTO THE UPPER MIDWEST AFTER MIDNIGHT BUT THE SEVERE THREAT SHOULD GRADUALLY BECOME MARGINAL DUE TO WEAKENING INSTABILITY. ..BROYLES.. 04/06/2006  From SwoDy1 at goshenarc.org Fri Apr 7 00:53:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 06 Apr 2006 20:53:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070050 SWODY1 SPC AC 070048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT THU APR 06 2006 VALID 070100Z - 071200Z ...THERE IS A HIGH RISK OF SVR TSTMS EARLY THIS EVE ACROSS PARTS OF SE KS/NE OK/NW AR...AND SW MO.... ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA ACROSS MUCH OF THE OZARK PLATEAU.... ...THERE IS A MDT RISK OF SVR TSTMS EARLY THIS EVENING ACROSS PARTS OF EXTREME SE SD/ERN NEB AND WRN IA.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT AND HIGH RISK AREAS ACROSS A LARGE PART OF THE E CNTRL PLAINS INTO THE MID MO VALLEY.... MID-LEVEL CIRCULATION HAS DEVELOPED INTO THE CENTRAL HIGH PLAINS... BUT WILL REDEVELOP EASTWARD TOWARD THE MID/LOWER MISSOURI VALLEY... AS STRONG IMPULSE CONTINUES TO PIVOT AROUND ITS SOUTHEASTERN INTO EASTERN PERIPHERY. STRONGEST MID-LEVEL COOLING OVERNIGHT WILL SURGE NORTHEASTWARD FROM THE SOUTH CENTRAL PLAINS THROUGH THE LOWER MISSOURI VALLEY...WITH DEEP SURFACE CYCLONE BECOMING INCREASINGLY OCCLUDED ACROSS EASTERN NEBRASKA. STRONG FORCING FOR UPWARD VERTICAL MOTION/DESTABILIZATION LIKELY WILL MAINTAIN A SUBSTANTIAL SEVERE THREAT ANOTHER FEW HOURS ACROSS PARTS OF THE MID MISSOURI VALLEY...AND PARTS OF THE OZARK PLATEAU. HOWEVER...EXTENT OF THREAT IS MORE UNCERTAIN EASTWARD ACROSS THE MIDDLE MISSISSIPPI INTO THE LOWER OHIO VALLEY...WHERE CONSIDERABLE CLOUD COVER/CONVECTION IMPEDED LOW-LEVEL WARMING TODAY. ...MIDDLE MISSOURI VALLEY*... STRONG SHEAR/FORCING IN EXIT REGION OF 90-100+ KT 500 MB JET STREAK WILL SPREAD FROM EASTERN NEBRASKA/NORTHEAST KANSAS THROUGH EXTREME NORTHWEST MISSOURI/WESTERN IOWA THROUGH 02-03Z. THIS WILL MAINTAIN CONVECTIVE DEVELOPMENT...AND SEVERE THREAT SHOULD PERSIST AS ACTIVITY BEGINS TO INGEST MORE MOIST UNSTABLE BOUNDARY LAYER EAST OF THE MISSOURI RIVER. TONGUE OF 60F+ SURFACE DEW POINTS HAS ADVECTED INTO WESTERN IOWA ON SOUTHEASTERLY FLOW TO THE EAST OF DEEP SURFACE CYCLONE. EASTERLY COMPONENT TO LOW-LEVEL FLOW IS CONTRIBUTING TO ENLARGED HODOGRAPHS...WHICH COULD ENHANCE TORNADO THREAT IN STRONGER CELLS WITHIN DEVELOPING LINE. OTHERWISE... RISK FOR DAMAGING WINDS COULD STILL INCREASE WITH CONVECTIVE LINE ...BEFORE FORCING PIVOTS THROUGH REMAINDER OF INSTABILITY AXIS LATER THIS EVENING. ...OZARK PLATEAU*... SECOND AREA OF ENHANCED SEVERE POTENTIAL EARLY THIS EVENING WILL PERSIST NEAR MID-LEVEL JET CORE...WHERE MID-LEVEL WINDS VEER TO A MORE WESTERLY COMPONENT. THIS IS CONTRIBUTING TO A FAVORABLE HODOGRAPH STRUCTURE FOR MORE DISCRETE SUPERCELLS. POTENTIAL FOR TORNADOES...POSSIBLY STRONG...WILL CONTINUE AS ACTIVITY PROGRESSES THROUGH LINGERING BOUNDARY LAYER INSTABILITY AXIS WITH CAPE TO 2000 J/KG NEAR THE SOUTHEASTERN KANSAS/EASTERN OKLAHOMA BORDER AREAS. DEEPER INTO SOUTH CENTRAL MISSOURI/NORTH CENTRAL ARKANSAS...SEVERE POTENTIAL SEEMS LIKELY TO GRADUALLY DIMINISH ABOVE MORE STABLE BOUNDARY LAYER AFTER 03-04Z. *FOR MORE SPECIFIC AND UPDATED INFORMATION CONCERNING ONGOING OR IMMINENT CONVECTIVE THREATS...PLEASE KEEP WATCH FOR LATEST SPC MESOSCALE DISCUSSIONS. ..KERR.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 06:04:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 02:04:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070602 SWODY1 SPC AC 070601 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT FRI APR 07 2006 VALID 071200Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS MUCH OF NRN MS...NRN AL...AND PARTS OF SRN TN. THIS INCLUDES THE MEMPHIS TN/TUPELO MS AREAS EASTWARD INTO BIRMINGHAM AL AND CHATTANOOGA ...WHICH SEEMS LIKELY TO BE AT THE FOCUS FOR AN OUTBREAK OF SEVERE THUNDERSTORMS...INCLUDING THE RISK FOR SUPERCELLS WITH TORNADOES.... ...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO TONIGHT THROUGH A LARGE PORTION OF THE LOWER MISSISSIPPI VALLEY THROUGH THE TN VLY/SRN APPALACHIANS.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE AND HIGH RISK AREAS...ACROSS MUCH OF THE NATION EAST OF THE MS RIVER INTO THE APPALACHIANS.... THE LARGE-SCALE UPPER FLOW PATTERN HAS BECOME A BIT LESS PROGRESSIVE...BUT MODELS INDICATE THAT THE CENTRAL PLAINS CLOSED LOW WILL GRADUALLY EVOLVE INTO AN OPEN WAVE AND TURN SOUTHEASTWARD TODAY...LIKELY ADVANCING THROUGH MUCH OF THE LOWER MISSISSIPPI VALLEY BY 12Z SATURDAY. THIS IS FORECAST IN RESPONSE TO A SIGNIFICANT SMALLER SCALE IMPULSE ROTATING AROUND ITS SOUTHWESTERN/SOUTHERN PERIPHERY...AND FORCING ASSOCIATED WITH A NORTHERN STREAM TROUGH...WHICH WILL DIG THROUGH THE GREAT LAKES REGION. AS THIS OCCURS...A BROAD BELT OF STRONG CYCLONIC MID/UPPER FLOW IS PROGGED TO CONTINUE TO GRADUALLY OVERSPREAD MUCH OF THE GULF COAST STATES AND MID SOUTH INTO THE NORTHEAST. STRENGTHENING WIND FIELDS/SHEAR PROFILES WILL BECOME JUXTAPOSED WITH A RETURN FLOW OF BOUNDARY LAYER MOISTURE FROM THE WESTERN GULF OF MEXICO...THROUGH A BROAD AREA FROM THE LOWER/MIDDLE MISSISSIPPI VALLEY INTO THE APPALACHIANS. THIS IS EXPECTED TO SUPPORT INCREASING CONVECTIVE POTENTIAL...INCLUDING RISK FOR SEVERE STORMS...WHICH COULD BECOME FAIRLY NUMEROUS AND INTENSE BY THE AFTERNOON/EVENING HOURS. OTHER THUNDERSTORM ACTIVITY APPEARS POSSIBLE INTO CENTRAL PACIFIC COASTAL AREAS. APPROACHING UPPER TROUGH IS FORECAST TO GENERALLY REMAIN OFFSHORE...BUT MODELS INDICATE A FAIRLY SIGNIFICANT IMPULSE WILL PIVOT AROUND ITS EASTERN PERIPHERY...ACROSS THE CALIFORNIA COAST THROUGH THE SIERRA NEVADA BY THE END OF THE FORECAST PERIOD. ...LOWER MISSISSIPPI VALLEY THROUGH SOUTHERN APPALACHIANS... MODELS SUGGEST LEADING EDGE OF MID-LEVEL COOLING ASSOCIATED WITH THE PLAINS SYSTEM WILL OVERSPREAD MUCH OF THE REGION BY MID DAY. THIS WILL WEAKEN INHIBITION...AND SURFACE HEATING MAY BE ENOUGH TO INITIATE AT LEAST SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT AS BOUNDARY LAYER DEW POINTS CLIMB THROUGH THE 60S. AS MIXED LAYER CAPE INCREASES IN EXCESS OF 2000 J/KG...STRONG DEEP LAYER SHEAR WILL BE SUPPORTIVE OF SUPERCELLS. CONFLUENT REGIME ASSOCIATED WITH 30 TO 40 KT SOUTHWESTERLY LOW-LEVEL JET SEEMS A LIKELY FOCUS FOR ACTIVITY...FROM PARTS OF CENTRAL/SOUTHERN MISSISSIPPI THROUGH EASTERN TENNESSEE. SOME OF THESE SUPERCELLS MAY BECOME LONG-LIVED...AND MODELS SUGGEST SUBSTANTIALLY LARGE/CLOCKWISE CURVED HODOGRAPHS ALONG THIS AXIS TO SUPPORT POTENTIAL FOR A FEW STRONG TORNADOES. WITH THE APPROACH OF DIGGING UPPER TROUGH...STRENGTHENING MID/UPPER FORCING IS EXPECTED TO SUPPORT INCREASINGLY WIDESPREAD SEVERE THUNDERSTORMS FROM THE LOWER MISSISSIPPI VALLEY INTO MIDDLE TENNESSEE LATE THIS AFTERNOON INTO THE EVENING HOURS. ACTIVITY MAY BE SLOW TO WEAKEN AS STRONGER FORCING SHIFTS TOWARD THE SOUTHERN APPALACHIANS OVERNIGHT. ...OHIO VALLEY... DEFORMATION ZONE BETWEEN NORTHERN AND SOUTHERN STREAM IMPULSES APPEARS TO BE A LIKELY FOCUS FOR CONVECTIVE DEVELOPMENT TODAY. MODELS SUGGEST FAIRLY STRONG SURFACE HEATING WILL OCCUR ALONG AN AXIS FROM THE ST. LOUIS AREA EASTWARD THROUGH SOUTHERN OHIO... WHICH SHOULD SUPPORT WEAK TO MODERATE DESTABILIZATION AHEAD OF DEVELOPING/STRENGTHENING BAROCLINIC ZONE. FRONTAL ZONE IS PROGGED TO SURGE SOUTH OF THE GREAT LAKES REGION EARLY THIS AFTERNOON... THROUGH MUCH OF THE OHIO VALLEY BY EARLY EVENING. THIS FORCING IS EXPECTED TO BECOME SUFFICIENT FOR AN EVOLVING SQUALL LINE...WITH MIXED LAYER CAPE ON THE ORDER OF 1000 J/KG SUPPORTIVE OF VIGOROUS UPDRAFTS IN STRONG AND SHEARED WESTERLY FLOW. IN ADDITION TO LARGE HAIL...DAMAGING WIND GUSTS COULD BECOME FAIRLY NUMEROUS BY/ SHORTLY AFTER PEAK HEATING. ..KERR/CROSBIE.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 12:20:28 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 08:20:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071217 SWODY1 SPC AC 071216 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0716 AM CDT FRI APR 07 2006 VALID 071300Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS PARTS OF NORTHERN MS...NORTHERN AL...AND SOUTHERN TN... ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE MS VALLEY...TN VALLEY...AND SOUTHERN APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE REMAINDER OF THE OH VALLEY AND CENTRAL APPALACHIANS... ...OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES EXPECTED TODAY ACROSS PARTS OF THE LOWER/MID MS VALLEY AND TN VALLEY... MORNING WATER VAPOR IMAGERY SHOWS LARGE...DEEP UPPER LOW OVER NEB...WITH BAND OF VERY STRONG MID LEVEL WINDS EXTENDING AROUND BASE OF LOW FROM TX/OK INTO AR/MO. THIS SYSTEM IS FORECAST TO MOVE SOUTHEASTWARD TODAY...WITH STRONGEST MID LEVEL WINDS SPREADING ACROSS MUCH OF THE MID/LOWER MS VALLEY AND TN VALLEY. MEANWHILE...SURFACE LOW WILL DEVELOP SOUTHEASTWARD INTO SOUTHERN MO/NORTHERN AR BY EVENING. STRONG SOUTHERLY LOW LEVEL WINDS IN WARM SECTOR OF LOW WILL TRANSPORT RICH MOISTURE NORTHWARD AND HELP TO RAPIDLY DESTABILIZE THE AIR MASS BY EARLY AFTERNOON. ...LA/MS/TN/AL/GA... PRESENT INDICATIONS ARE THAT ISOLATED THUNDERSTORMS WILL DEVELOP BY EARLY AFTERNOON IN LOW LEVEL JET AXIS ACROSS PARTS OF LA/MS. THESE STORMS SHOULD MOVE RAPIDLY EAST-NORTHEASTWARD INTO NORTHERN AL AND MIDDLE TN DURING THE AFTERNOON/EVENING. MODEL FORECAST SOUNDINGS IN THIS REGION INDICATE VERY FAVORABLE LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES FOR SUPERCELLS AND TORNADOES /EFFECTIVE SHEAR OVER 50 KNOTS AND 3KM SRH VALUES OF 250-400 M2/S2/. ASSUMING MID 60S SURFACE DEWPOINTS BECOME WIDESPREAD IN THIS REGION AHEAD OF CONVECTION...THERMODYNAMIC PARAMETERS ALSO APPEAR QUITE FAVORABLE FOR A FEW STRONG/LONG-TRACK TORNADOES /MLCAPE OF 1500-2000 J/KG...MINIMAL CAP...AND LCL HEIGHTS GENERALLY BELOW 1KM/. WIDESPREAD LARGE HAIL WILL BE A THREAT ACROSS THIS REGION AS WELL. ACTIVITY MAY SPREAD AS FAR EAST AS NORTHWEST GA AND EASTERN TN BY LATE EVENING WITH A CONTINUED THREAT OF TORNADOES AND DAMAGING WINDS. ...MID MS/LOWER OH VALLEYS... STRONG DAYTIME HEATING IS EXPECTED ACROSS PARTS OF SERN MO/ERN AR/SRN IL/WRN KY THROUGH EARLY AFTERNOON. THIS SHOULD YIELD VERY STEEP LOW/MID LEVEL LAPSE RATES AND MLCAPE VALUES OVER 2000 J/KG. DEEP LAYER EFFECTIVE SHEAR OVER 60 KNOTS AND SUFFICIENT LOW LEVEL SHEAR WILL PROMOTE SUPERCELL STORMS CAPABLE OF VERY LARGE HAIL AND ISOLATED TORNADOES. ACTIVITY WILL LIKELY SPREAD EASTWARD ACROSS PARTS OF IND/KY/TN THROUGH THE AFTERNOON AND EVENING. ...IL/IND/OH/PA... SURFACE FRONT IS FORECAST TO EXTEND FROM CENTRAL MO INTO NORTHERN OH/NORTHWESTERN PA BY MID AFTERNOON. STRONG HEATING IS EXPECTED ALONG AND SOUTH OF FRONT RESULTING IN AT LEAST MODERATE INSTABILITY. SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO FORM IN THIS REGION AS CONVECTIVE TEMPERATURE IS REACHED AND JET STREAK APPROACHES FROM THE WEST. LARGE HAIL APPEARS TO BE THE MAIN THREAT...ALTHOUGH DAMAGING WINDS WILL ALSO BE POSSIBLE THROUGH THE AFTERNOON/EVENING AS CLUSTERS MERGE AND GROW UPSCALE. ..HART/CROSBIE.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 16:37:31 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 12:37:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071634 SWODY1 SPC AC 071632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT FRI APR 07 2006 VALID 071630Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS TODAY ACROSS PARTS OF NORTHERN MISSISSIPPI...NORTHERN ALABAMA AND WESTERN/MIDDLE TENNESSEE... ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF THE LOWER/MIDDLE MS VALLEY...TN VALLEY...LOWER OH VALLEY AND SOUTHERN APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE REMAINDER OF THE OH VALLEY AND CENTRAL APPALACHIANS... ...OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES EXPECTED TODAY INTO TONIGHT ACROSS PARTS OF THE LOWER/MID MS VALLEY AND OH/TN VALLEYS... ...SYNOPSIS... WATER VAPOR IMAGERY THIS MORNING INDICATED DEEP UPPER LOW OVER THE CENTRAL PLAINS HAD BEGUN TO MOVE TOWARD THE ESE....WITH THIS TREND EXPECTED TO CONTINUE TODAY AS LOW REACHES THE LOWER MS/TN VALLEYS BY 12Z SATURDAY. BAND OF VERY STRONG MID LEVEL WINDS WITHIN BASE OF LOW FROM TX/OK INTO LOWER OH VALLEY WILL CONTINUE TO SPREAD DOWNSTREAM ACROSS MUCH OF THE MID/LOWER MS VALLEY AND TN/OH VALLEYS. IN THE LOW LEVELS...SURFACE LOW LOCATED OVER NRN/NERN KS...WILL DEVELOP SOUTHEASTWARD INTO SRN MO/NRN AR BY EVENING. MEANWHILE... A COLD FRONT...ASSOCIATED WITH A STRONG NRN STREAM UPPER TROUGH OVER ERN CANADA...CURRENTLY EXTENDED FROM SRN QUEBEC SWWD THROUGH SRN LOWER MI TO SRN IA. THIS BOUNDARY WILL MOVE SSE ACROSS THE NERN STATES AND OH VALLEY REGION TODAY...AND SHOULD EXTEND FROM THE DELMARVA REGION TO THE TN VALLEY BY 12Z SATURDAY. STRONG SLY LOW LEVEL WINDS IN WARM SECTOR OF LOW AND S OF COLD FRONT WILL TRANSPORT RICH MOISTURE NORTHWARD. ...LA/MS/TN/AL/GA INTO MID MS/OH VALLEYS... SEVERAL ROUNDS OF SEVERE STORMS APPEAR LIKELY ESPECIALLY ACROSS THE HIGH RISK AREA FROM NRN MS/AL INTO WRN/MIDDLE TN...WITH THREAT EXTENDING EWD INTO ERN TN/NRN GA BY THIS EVENING. FORECAST SOUNDINGS CONTINUE TO INDICATE THERMODYNAMIC PARAMETERS QUITE FAVORABLE FOR A FEW STRONG/LONG-TRACK TORNADOES /MUCAPE OF 2000-3000 J/KG AND LCL HEIGHTS GENERALLY BELOW 1KM/ ACROSS NRN MS/NRN AL AND WRN/MIDDLE TN. RAPID DESTABILIZATION IS UNDERWAY WITHIN WEAKLY CAPPED AIR MASS ACROSS THE LOWER/MID MS VALLEYS INTO LOWER OH VALLEY WITH SURFACE DEWPOINTS IN UPPER 50S/LOWER 60S EXPECTED TO SPREAD ACROSS MUCH OF THE OH VALLEY BY THIS AFTERNOON...AND MID 60S ACROSS MUCH OF THE MODERATE AND HIGH RISK AREAS. ABUNDANT SURFACE HEATING WILL CONTINUE TO AID IN THIS DESTABILIZATION PROCESS FURTHER WEAKENING CAP AS INDICATED PER SPECIAL 14Z JAN SOUNDING. PLUME OF STEEP LAPSE RATES WILL SPREAD EWD INTO OH VALLEY AND EXISTING STEEP LAPSE RATES ACROSS REST OF WARM SECTOR WILL COMBINE WITH MOISTURE AND INSOLATION TO RESULT IN MUCAPE RANGING FROM 2000-3000 J/KG ACROSS THE MODERATE AND HIGH RISK AREAS BY THIS AFTERNOON. STRONG VEERING WIND PROFILES WITH HEIGHT /40-50 KT SSWLY LOW-LEVEL WINDS BENEATH 80 KT SWLY MID-LEVEL WINDS/ WILL PROVIDE A FAVORABLE ENVIRONMENT /EFFECTIVE SHEAR OVER 50 KT AND 0-3 KM SRH VALUES OF 250-400 M2/S2/ FOR SUPERCELLS PRODUCING TORNADOES...VERY LARGE HAIL AND DAMAGING WINDS. FARTHER N...AIR MASS WILL CONTINUE TO DESTABILIZE FROM IL/IND EWD ACROSS OH/PA IN ADVANCE OF THE COLD FRONT. STRENGTHENING WIND FIELDS WILL RESULT IN FAVORABLE DEEP LAYER SHEAR FOR THUNDERSTORMS TO DEVELOP AS THE COLD FRONT MOVES SSEWD INTO THE MODERATELY UNSTABLE AIR MASS. DEEP LAYER SHEAR VECTORS ORIENTED NEARLY PARALLEL TO THE FRONT SUGGEST ACTIVITY WILL PRIMARILY BE LINEAR... BUT SUPERCELLS WITH AN ATTENDANT TORNADO THREAT WILL BE POSSIBLE ESPECIALLY ACROSS SRN IL/IND INTO SRN OH WHERE LOW-LEVEL MOISTURE WILL BE GREATER. ...CENTRAL APPALACHIANS... SEVERE THREAT MAY DEVELOP AS FAR EAST AS THE CENTRAL APPALACHIANS AS AIR MASS DESTABILIZES IN THE WAKE OF MORNING SHOWERS/ THUNDERSTORMS. STRONG DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ORGANIZED STORMS INTO PARTS OF SRN PA AND POTENTIALLY WRN MD/ERN WV AS MLCAPE VALUES REACH AROUND 1000 J/KG. ADDITIONAL STRONG TO SEVERE STORMS THAT DEVELOP ACROSS THE OH/TN VALLEYS TODAY SHOULD APPROACH THE CENTRAL/SRN APPALACHIANS THIS EVENING...BUT EWD SEVERE THREAT WILL BE LIMITED BY DIMINISHING INSTABILITY OVERNIGHT. ...PARTS OF KS/OK/WRN MO/NWRN AR... COLD MID LEVEL TEMPERATURES WITH CENTRAL PLAINS LOW ATOP PROGGED WEAK LOW-LEVEL WARM AIR ADVECTION SHOULD RESULT IN DESTABILIZING THE AIR MASS ACROSS THIS REGION FOR A FEW THUNDERSTORMS THIS AFTERNOON. WEAK INSTABILITY/SHEAR WILL TEND TO LIMIT THE SEVERE POTENTIAL...BUT A FEW OF THE STRONGER CORES MAY BE CAPABLE OF PRODUCING ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL DIMINISH THIS EVENING GIVEN THE ONSET OF STABILIZATION PER THE LOSS OF DAY TIME HEATING. ..PETERS/GRAMS.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:04:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:04:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072001 SWODY1 SPC AC 071959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:10:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:10:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072007 SWODY1 SPC AC 072006 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Fri Apr 7 20:18:16 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 07 Apr 2006 16:18:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 072014 SWODY1 SPC AC 072013 DAY 1 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0313 PM CDT FRI APR 07 2006 VALID 072000Z - 081200Z ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF MS...AL AND TN... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MS...AL...TN...GA...LA...KY...IL...IND...OH...VA AND NC... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY...GULF COAST...OH VALLEY AND CNTRL APPALACHIANS... ...TENNESSEE AND OHIO VALLEYS/LOWER MS VALLEY... MAJOR TORNADO OUTBREAK IS CURRENTLY UNDERWAY ACROSS THE TENNESSEE VALLEY AND SRN OH VALLEY. AS THE AFTERNOON CONTINUES...IN ADDITION TO THE DAMAGING STORMS ACROSS TN AND KY...NUMEROUS TORNADIC STORMS WITH A POTENTIAL FOR STRONG TO VIOLENT TORNADOES WILL INITIATE NEAR THE MS RIVER AND TRACK ENEWD ACROSS THE HIGH RISK AREA. WATER VAPOR IMAGERY CURRENTLY SHOWS A POTENT UPPER-LOW OVER THE CNTRL PLAINS WITH AN ASSOCIATED 90 KT MID-LEVEL JET PUNCHING ENEWD ACROSS THE MID-MS VALLEY REGION. THE JET IS ENHANCING LIFT AND VERTICAL SHEAR ACROSS KY AND TN WHERE NUMEROUS SUPERCELL STORMS ARE ONGOING IN THE NOSE OF THE APPROACHING JET. SFC AND OBJECTIVE ANALYSIS CURRENTLY SHOW A LARGE VOLATILE WARM SECTOR WITH SFC DEWPOINTS IN THE 60S F AND MODERATE TO STRONG INSTABILITY OVER A LARGE AREA OF THE MISSISSIPPI...OHIO AND TENNESSEE VALLEYS. IN ADDITION TO THE LARGE WARM SECTOR AND STRONG VERTICAL SHEAR PROFILES...WSR-88D VAD WIND PROFILERS SHOW IDEAL LOW-LEVEL SHEAR CONDITIONS FOR TORNADOES OVER MUCH OF THE WARM SECTOR. IN ADDITION TO TORNADOES....VERY LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE INTENSE SUPERCELLS. THE FIRST ROUND OF EXTREMELY DANGEROUS STORMS WILL CONTINUE TO MOVE ENEWD INTO THE CNTRL APPALACHIAN MTNS WITH A SECOND ROUND OF VERY INTENSE STORMS JUST ABOUT TO BEGIN FURTHER SOUTH ACROSS THE TN VALLEY. 1930Z VISIBLE SATELLITE IMAGERY SHOWS AN EXPANDING CUMULUS FIELD OVER NRN LA...SERN AR AND NW MS. AS LARGE-SCALE ASCENT INCREASES AHEAD OF THE APPROACHING TROUGH...RAPID SUPERCELL INITIATION SHOULD TAKE PLACE JUST AHEAD OF A LOW TO MID-LEVEL JET PUNCHING INTO THE AREA. AS THE JET PUNCHES EWD ACROSS NRN MS AND NRN AL...SHEAR PROFILES WILL BECOME VERY FAVORABLE FOR LONG-LIVED STRONG TORNADIC SUPERCELLS. AN OUTBREAK OF STRONG TORNADOES SHOULD OCCUR ACROSS NRN AND CNTRL MS...NRN AL AND SCNTRL TN. AS THE STORMS TRACK ENEWD...SEVERAL LONG-LIVED VIOLENT TORNADOES NOW APPEAR INCREASINGLY LIKELY AS A 50 KT LOW-LEVEL JET FEEDS NWD INTO THE TORNADIC STORMS ACROSS NRN MS...NRN AL AND SCNTRL TN. THE THREAT OF STRONG TO VIOLENT TORNADOES WILL CONTINUE AS INTENSE TORNADIC SUPERCELLS MOVE ENEWD THIS AFTERNOON ACROSS SRN TN...NRN AL AND POSSIBLE AS FAR EAST AS NWRN GA. BY THIS EVENING...THE POTENTIAL FOR TORNADOES WILL EXIST ACROSS A LARGE AREA FROM THE OH VALLEY EXTENDING SWD ACROSS THE TN VALLEY AND LOWER MS VALLEY. A FEW AREAS OF ENHANCED TORNADO POTENTIAL OUTSIDE THE HIGH RISK AREA FOR STRONG TORNADOES THROUGH EARLY THIS EVENING EXIST OVER SRN IL AND SRN IND WHERE INSTABILITY IS MAXIMIZED. ENHANCED POTENTIAL FOR STRONG TORNADOES WILL ALSO EXIST AS SUPERCELLS INITIATE LATER THIS AFTERNOON AND EARLY THIS EVENING OVER LA AND CNTRL MS. THE TORNADO/SEVERE THREAT WILL CONTINUE THROUGH MUCH OF THE EVENING AS STORMS TRACK EWD ACROSS THE GULF COAST STATES AND SRN/CNTRL APPALACHIAN MTNS. ALTHOUGH THE SEVERE WEATHER THREAT MAY DECREASE SOME AFTER MIDNIGHT DUE TO DECREASING INSTABILITY...ANY SUPERCELLS THAT CONTINUE ACROSS THE REGION WILL HAVE A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. ...ERN APPALACHIAN FOOTHILLS/ERN SEABOARD. FURTHER EAST ACROSS THE MID-ATLANTIC STATES AND WRN CAROLINAS...DESTABILIZATION WILL CONTINUE AND THE ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SEVERE STORMS LATE THIS AFTERNOON THROUGH THIS EVENING. ALTHOUGH AN ISOLATED TORNADO THREAT MAY EXIST ALONG THE ERN SEABOARD TONIGHT...THE MAIN THREATS ARE EXPECTED TO BE LARGE HAIL AND ISOLATED WIND DAMAGE. ..BROYLES.. 04/07/2006  From SwoDy1 at goshenarc.org Sat Apr 8 06:03:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 02:03:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080559 SWODY1 SPC AC 080558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SAT APR 08 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS THE EASTERN GULF STATES INTO THE SOUTHERN/MID ATLANTIC COAST.... SOUTHERN STREAM SHORT WAVE TROUGH HAS FINALLY BECOME MORE PROGRESSIVE...AND IS NOW DIGGING THROUGH THE LOWER MISSISSIPPI VALLEY...MORE OR LESS IN PHASE WITH A VIGOROUS NORTHERN BRANCH TROUGH DIGGING INTO THE LOWER GREAT LAKES/ST. LAWRENCE VALLEY. MODELS SUGGEST NORTHERN SYSTEM WILL RAPIDLY PIVOT THROUGH NORTHERN NEW ENGLAND AND THE CANADIAN MARITIMES DURING THIS FORECAST PERIOD. SOUTHERN IMPULSE IS PROGGED TO BE A BIT SLOWER...BUT APPEARS LIKELY TO GRADUALLY TAKE ON MORE OF A NEUTRAL TILT AS IT APPROACHES THE MID/SOUTH ATLANTIC COAST BY 12Z SUNDAY. SURFACE COLD INTRUSIONS ASSOCIATED WITH BOTH FEATURES WILL EVENTUALLY SURGE THROUGH THE LEE OF THE SOUTHERN APPALACHIANS... AND THROUGH THE REMAINDER OF THE CENTRAL/EASTERN GULF STATES. HOWEVER...THIS GENERALLY WILL NOT OCCUR UNTIL LATER TODAY/TONIGHT. PRE-FRONTAL ENVIRONMENT IS BECOMING INCREASINGLY MOIST ACROSS THE EASTERN GULF STATES...AND SIMILAR MOISTENING IS POSSIBLE OVER SOUTH ATLANTIC COASTAL AREAS AS SURFACE RIDGING FINALLY WEAKENS/RETREATS TO THE EAST. SURFACE DEW POINTS AT OR ABOVE 60F MAY OVERSRPREAD MUCH OF THE SOUTHEAST BY MIDDAY. COOLING/DRYING IN WAKE OF COLD FRONTS...BENEATH BROADLY ANTICYCLONIC UPPER FLOW DEVELOPING INTO THE CENTRAL/EASTERN STATES SHOULD PRECLUDE CONVECTIVE POTENTIAL MOST OTHER AREAS EAST OF THE ROCKIES. ACROSS THE WEST...MAIN SHORT WAVE IMPULSE WITHIN BROADER SCALE TROUGH WILL REMAIN WEST OF THE PACIFIC COAST THROUGH THIS PERIOD. BUT...WEAKER IMPULSE ALREADY LIFTING OUT OF TROUGH INTO THE NORTHERN INTERMOUNTAIN REGION WILL CONTINUE THROUGH THE NORTHERN ROCKIES BY LATE TONIGHT. ...SOUTHEAST... MODERATELY STRONG AND SHEARED FLOW REGIME WILL DEVELOP ACROSS MUCH OF THE REMAINDER OF THE EASTERN GULF/SOUTH ATLANTIC COAST STATES TODAY. PRIMARY UNCERTAINTY CONCERNING EXTENT OF SEVERE THREAT INVOLVES INFLUENCE OF CONVECTIVE SYSTEM EXPECTED TO BE ONGOING FROM THE LEE OF THE SOUTHERN APPALACHIANS THROUGH PARTS OF SOUTHERN ALABAMA/MISSISSIPPI AT 12Z. LOWER LEVELS IN THE LEE OF THE APPALACHIANS MAY STILL BE TOO DRY EARLY IN THE DAY TO SUPPORT CONTINUING SEVERE THREAT ACROSS THE SOUTH ATLANTIC COAST STATES... AND CLOUD COVER WITH DISSIPATING CONVECTION COULD IMPEDE SURFACE HEATING. BEST MOIST INFLOW INTO CONVECTION IS EXPECTED ACROSS NORTHERN FLORIDA INTO SOUTHERN GEORGIA...WHERE LINE OF STRONG/SEVERE STORMS ...PRIMARILY WITH HAIL/DAMAGING WINDS...APPEARS POSSIBLE THIS MORNING INTO EARLY AFTERNOON. OTHERWISE...AIR MASS MAY BECOME SUFFICIENTLY UNSTABLE IN WAKE OF EARLY CONVECTION FOR SCATTERED SEVERE STORMS AHEAD OF COLD FRONT ACROSS CENTRAL/SOUTHEAST ALABAMA. STORMS SHOULD FORM AS MID-LEVEL THERMAL TROUGH AXIS OVERSPREADS ALABAMA DURING THE AFTERNOON HOURS...AND ACTIVITY COULD SPREAD BACK INTO SOUTHERN GEORGIA BEFORE WEAKENING. FARTHER EAST...THOUGH CAPE MAY NOT BECOME PARTICULARLY STRONG...FORCING AHEAD OF SOUTHERN BRANCH TROUGH COULD BECOME SUPPORTIVE OF A NEW LINE OF STORMS BY LATE AFTERNOON ACROSS PARTS OF THE EASTERN CAROLINAS/SOUTHEAST VIRGINIA. SHEAR WILL BE MORE THAN SUFFICIENT FOR UPDRAFT ROTATION...BUT PRIMARY SEVERE THREAT SEEMS LIKELY TO BE DAMAGING WINDS AND HAIL IN 40 TO 50+ KT SOUTHWESTERLY MEAN FLOW. ..KERR/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 12:27:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 08:27:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081224 SWODY1 SPC AC 081223 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0723 AM CDT SAT APR 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... WATER VAPOR IMAGERY THIS MORNING SHOWS UPPER TROUGH OVER THE MID MS VALLEY. THIS FEATURE WILL TRACK EASTWARD TODAY THROUGH THE TN VALLEY...WHILE SURFACE COLD FRONT SWEEPS TOWARD THE SOUTHEAST COAST. OVERALL SEVERE THREAT WILL BE SIGNIFICANTLY LESS THAN YESTERDAY. HOWEVER...POTENTIAL WILL EXIST FOR ISOLATED LARGE HAIL...DAMAGING WINDS...AND TORNADOES OVER PARTS OF THE SOUTHEAST STATES. ...AL/GA/SC/NC/VA/FL... BAND OF STRONG CONVECTION CURRENTLY EXTENDS FROM CENTRAL AL...ACROSS CENTRAL GA...INTO CENTRAL NC. VISIBLE SATELLITE IMAGERY SUGGESTS THAT POCKETS OF DAYTIME HEATING WILL DEVELOP AHEAD OF LINE...RESULTING IN LATE MORNING/EARLY AFTERNOON MLCAPE VALUES OF 1000-1500 J/KG. THIS WILL AID IN THE RE-INTENSIFICATION OF STORMS BEFORE NOON ACROSS SOUTHEAST VA...EASTERN CAROLINAS...AND SOUTHERN GA/AL. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE MAIN THREAT. STRONG DEEP LAYER VERTICAL SHEAR WILL BE PRESENT ACROSS THIS REGION PROMOTING POTENTIAL FOR A FEW SUPERCELLS AND PERHAPS TORNADOES. ACTIVITY SHOULD SPREAD SOUTHEASTWARD INTO NORTHERN FL DURING THE LATE AFTERNOON/EARLY EVENING BEFORE WEAKENING. ELSEWHERE ACROSS THE NATION...NO SEVERE THUNDERSTORMS ARE FORECAST TODAY. ..HART/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 12:27:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 08:27:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081224 SWODY1 SPC AC 081223 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0723 AM CDT SAT APR 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... WATER VAPOR IMAGERY THIS MORNING SHOWS UPPER TROUGH OVER THE MID MS VALLEY. THIS FEATURE WILL TRACK EASTWARD TODAY THROUGH THE TN VALLEY...WHILE SURFACE COLD FRONT SWEEPS TOWARD THE SOUTHEAST COAST. OVERALL SEVERE THREAT WILL BE SIGNIFICANTLY LESS THAN YESTERDAY. HOWEVER...POTENTIAL WILL EXIST FOR ISOLATED LARGE HAIL...DAMAGING WINDS...AND TORNADOES OVER PARTS OF THE SOUTHEAST STATES. ...AL/GA/SC/NC/VA/FL... BAND OF STRONG CONVECTION CURRENTLY EXTENDS FROM CENTRAL AL...ACROSS CENTRAL GA...INTO CENTRAL NC. VISIBLE SATELLITE IMAGERY SUGGESTS THAT POCKETS OF DAYTIME HEATING WILL DEVELOP AHEAD OF LINE...RESULTING IN LATE MORNING/EARLY AFTERNOON MLCAPE VALUES OF 1000-1500 J/KG. THIS WILL AID IN THE RE-INTENSIFICATION OF STORMS BEFORE NOON ACROSS SOUTHEAST VA...EASTERN CAROLINAS...AND SOUTHERN GA/AL. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE MAIN THREAT. STRONG DEEP LAYER VERTICAL SHEAR WILL BE PRESENT ACROSS THIS REGION PROMOTING POTENTIAL FOR A FEW SUPERCELLS AND PERHAPS TORNADOES. ACTIVITY SHOULD SPREAD SOUTHEASTWARD INTO NORTHERN FL DURING THE LATE AFTERNOON/EARLY EVENING BEFORE WEAKENING. ELSEWHERE ACROSS THE NATION...NO SEVERE THUNDERSTORMS ARE FORECAST TODAY. ..HART/GUYER.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 16:31:21 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 12:31:21 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081623 SWODY1 SPC AC 081621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT SAT APR 08 2006 VALID 081630Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... ...SERN STATES... VIGOROUS UPPER TROUGH FROM OH VALLEY TO LOWER MS VALLEY WILL CONTINUE EWD REACHING ATLANTIC COAST LATE TONIGHT. COLD FRONT FROM DELMARVA SWWD THRU ERN TN VALLEY TO OFFSHORE SERN LA WILL BE TRAILING SWWD ACROSS CENTRAL FL PENINSULA INTO GULF BY LATER TONIGHT. PREFRONTAL CONVECTION HAS CONTINUED OVERNIGHT WITH A WELL DEFINED BOUNDARY TRAILING WWD ACROSS CENTRAL GA INTO SRN AL. WARM SECTOR TO S AND E OF THIS BOUNDARY HAS BECOME MDTLY UNSTABLE EWD INTO SRN SC. WARM SECTOR CHARACTERIZED BY STRONG DEEP LAYER SHEAR OF 60-70 KT ALONG WITH SFC-1KM SHEAR AROUND 20KT WHICH SUPPORTS ORGANIZED THUNDERSTORMS INCLUDING SUPERCELLS THIS AFTERNOON AND EVENING. WITH MLCAPES TO 2000 J/K AND MID LEVEL LAPSE RATES IN EXCESS OF 7C/KM AND AS OF 16Z MINIMAL REMAINING CIN...THUNDERSTORMS WILL INCREASE IN BOTH NUMBER AND INTENSITY THRU THE MIDDLE OF THE AFTERNOON EWD ACROSS SRN GA/NRN FL INTO COASTAL SC. SUPERCELLS ARE LIKELY WITH THE MOST FAVORED AREA FOR TORNADO POTENTIAL IN THE ENHANCE SHEAR ALONG THE E/W BOUNDARY THAT EXTENDS ACROSS GA JUST S OF MCN. THUNDERSTORMS WILL DEVELOP FROM CURRENT LOCATION CENTRAL GA TO SRN AL E AND NEWD DURING AFTERNOON INTO SRN SC AND THRU THE FL PANHANDLE AS HEATING CONTINUES. THREAT FOR LARGE HAIL AND ISOLATED TORNADOS WILL INCREASE ACCORDINGLY. FURTHER N THE EARLIER CONVECTIVE ACTIVITY HAS MOVED OFFSHORE AND COASTAL NC/SERN VA SHOULD HAVE TIME TO RECOVER AND DESTABILIZE PRIOR TO THE ARRIVAL OF THE COLD FRONT. AS A RESULT WILL CONTINUE THREAT OF REDEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS COASTAL AREAS WITH THE STRONG PREDOMINANTLY UNIDIRECTIONAL FLOW FAVORING LARGE HAIL AND DAMAGING WINDS ..HALES/GRAMS.. 04/08/2006  From SwoDy1 at goshenarc.org Sat Apr 8 19:46:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 15:46:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081944 SWODY1 SPC AC 081942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0242 PM CDT SAT APR 08 2006 VALID 082000Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST STATES... ...SERN STATES... EARLY AFTERNOON SURFACE ANALYSIS SHOWED SYNOPTIC COLD FRONT EXTENDED FROM SERN VA WSWWD THROUGH WRN NC/SC TO NERN GA...AND THEN SWWD ACROSS CENTRAL GA/SERN AL TO OVER THE NRN GULF OF MEXICO. PRIMARY FOCI FOR ONGOING AND ADDITIONAL THUNDERSTORMS EXPECTED TO BE SRN EXTENT OF COLD FRONT...NOW LOCATED OVER SERN AL/WRN FL PANHANDLE...AND PRE-FRONTAL TROUGH/OUTFLOW BOUNDARIES MOVING E/SE ACROSS ERN CAROLINAS AND SRN GA/FL PANHANDLE INTO NRN FL. WARM SECTOR AIR MASS WILL REMAIN UNSTABLE INTO THE EVENING...WITH GREATEST INSTABILITY /MLCAPE 1000-2000 J/KG/ EXTENDING ACROSS SRN SC/SRN GA/FAR SERN AL/FL PANHANDLE AND NRN FL. STRONG CENTRAL GULF COAST STATES SHORT WAVE TROUGH WILL CONTINUE EWD REACHING THE SRN ATLANTIC COAST BY 12Z SUNDAY. LARGE SCALE ASCENT IN ADVANCE OF THIS TROUGH AND ENHANCED LOW-LEVEL CONVERGENCE IN THE VICINITY OF A COUPLE OF FRONTAL WAVES...NOW LOCATED OVER SRN AL/SRN GA...AND BOUNDARIES WILL MAINTAIN DEEP MOIST CONVECTION WITHIN UNSTABLE WARM SECTOR. SUPERCELLS AND LINES/BOWS ARE EXPECTED TO REMAIN LIKELY GIVEN STRONG DEEP LAYER AND LOW-LEVEL SHEAR WITHIN MODERATELY UNSTABLE ENVIRONMENT. HAIL/DAMAGING WINDS WILL BE LIKELY WITHIN ENTIRE WARM SECTOR. GREATEST TORNADO THREAT EXPECTED TO BE ACROSS FAR SERN AL/FL PANHANDLE EWD THROUGH SRN GA/NRN FL TO SRN SC WHERE INSTABILITY WILL REMAIN THE GREATEST...AND DEEP LAYER SHEAR VECTORS ARE ORIENTED MORE NORMAL TO THE BOUNDARIES ALLOWING FOR DISCRETE STORMS. THREAT FOR SEVERE STORMS WILL CONTINUE INTO THE MID-LATE EVENING AND OVERNIGHT AS PRE-FRONTAL CONVECTIVE BAND AND COLD FRONT MOVE INTO NRN FL WHERE EFFECTIVE SHEAR/INSTABILITY SHOULD REMAIN CONDUCIVE FOR ORGANIZED STORMS. ..PETERS.. 04/08/2006  From SwoDy1 at goshenarc.org Sun Apr 9 00:45:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 08 Apr 2006 20:45:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090043 SWODY1 SPC AC 090041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 PM CDT SAT APR 08 2006 VALID 090100Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER FAR SERN GA SWD INTO NRN AND CNTRL FL... ...SERN GA / NRN AND CNTRL FL... CLUSTERS OF STRONG TO SEVERE TSTMS ARE ONGOING THIS EVENING FROM NEAR AND N OF JAX SWWD INTO THE NERN GULF OF MEXICO AHEAD OF SRN STREAM MID-LEVEL TROUGH EXTENDING FROM THE SRN APPALACHIANS SWD INTO THE CNTRL GULF OF MEXICO. MOIST BOUNDARY-LAYER CONDITIONS COUPLED WITH MODEST LAPSE RATES ARE SUSTAINING A MODERATELY UNSTABLE AIR MASS AHEAD OF THESE STORMS PER 00Z JAX/TBW SOUNDINGS WITH MLCAPES OF 1000-1500 J/KG. STRONGEST MID AND HIGH-LEVEL WIND FIELDS ARE FORECAST TO LIFT NEWD ACROSS THE WRN ATLANTIC IN ADVANCE OF MORE PROGRESSIVE NRN STREAM TROUGH MOVING THROUGH THE NRN AND CNTRL APPALACHIANS. HOWEVER...40-45 KT WLY MID-LEVEL FLOW WILL BE SUSTAINED ACROSS PRE-FRONTAL INSTABILITY AXIS ACROSS THE CNTRL FL PENINSULA OVERNIGHT. HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH SHOULD MAINTAIN NE-SW ORIENTED BANDS OF TSTMS THROUGH THE REMAINDER OF THE EVENING INTO OVERNIGHT WITH THIS ACTIVITY GRADUALLY SHIFTING SWD INTO THE CNTRL PENINSULA. GIVEN THE MODEST LAPSE RATES AND MODERATELY STRONG UNIDIRECTIONAL WIND FIELDS...POTENTIAL WILL EXIST FOR ISOLATED DAMAGING WIND GUSTS AND SEVERE HAIL WITH THE MOST INTENSE STORMS. ..MEAD.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 05:18:43 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 01:18:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090515 SWODY1 SPC AC 090514 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1214 AM CDT SUN APR 09 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER S FL... ...SYNOPSIS... NRN STREAM MID-LEVEL TROUGH FROM QUEBEC SWD TO THE MIDDLE ATLANTIC COAST WILL BECOME NEGATIVELY TILTED OVER THE CANADIAN MARITIMES...WHILE WEAKER SRN STREAM TROUGH WILL MORE SLOWLY SHIFT EWD ACROSS THE ERN GULF OF MEXICO THROUGH FL INTO THE WRN ATLANTIC. IN THE W...NEXT UPSTREAM TROUGH WILL EVOLVE OVER THE PACIFIC NW AND GREAT BASIN...WITH AN ASSOCIATED VORTICITY MAXIMUM/JET STREAK MOVING THROUGH THE MEAN TROUGH NEWD INTO NV/UT. IN THE LOW-LEVELS...COLD FRONT INITIALLY OVER THE NRN FL PENINSULA WILL PUSH SWD THROUGH REMAINDER OF THE PENINSULA TODAY...EVENTUALLY INTO THE FL STRAITS LATE TONIGHT. IN THE W...SURFACE LOW OVER NV WILL DEVELOP NEWD INTO NRN HIGH PLAINS IN ADVANCE OF EVOLVING UPPER TROUGH WHILE TRAILING PACIFIC FRONT PUSHES EWD INTO THE GREAT BASIN. ...S FL... 09/00Z UPPER AIR AND CURRENT SURFACE OBSERVATIONS INDICATE THE PRESENCE OF A VERY MOIST LOW-LEVEL AIR MASS WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. THIS MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO THE DEVELOPMENT OF MODERATE INSTABILITY TODAY AHEAD OF COLD FRONT WITH MLCAPES INCREASING TO 1500-2000 J/KG. W-E ORIENTED BANDS OF TSTMS WILL LIKELY BE ONGOING AT THE ONSET OF FORECAST OVER THE CNTRL PENINSULA WITHIN MOIST...PRE-FRONTAL WARM SECTOR. DESTABILIZATION OF INFLOW AIR MASS ALONG WITH 30 METER HEIGHT FALLS ALONG SRN FRINGE OF SRN STREAM TROUGH MOVING THROUGH THE AREA SHOULD SUPPORT STORM INTENSIFICATION LATER TODAY...WITH THE POTENTIAL FOR A FEW SEVERE STORMS CONTINUING INTO THIS EVENING. FORECAST SOUNDINGS SUGGEST THAT VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG OWING TO THE VEERED LOW-LEVEL WINDS AND ONLY 30-40 KT FLOW IN THE MID-LEVELS. NONETHELESS...THE MODERATE INSTABILITY AND UNIDIRECTIONAL WIND PROFILES SUGGEST THE POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS AND PERHAPS SEVERE HAIL WITH THE MOST INTENSE STORMS. ..MEAD/GUYER.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 12:46:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 08:46:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091242 SWODY1 SPC AC 091241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 AM CDT SUN APR 09 2006 VALID 091300Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FL... ...SYNOPSIS... PRIMARY SEVERE THREAT THROUGH THE DAY/EARLY EVENING WILL RESIDE ACROSS SOUTHERN FL...WHERE ISOLATED SEVERE STORMS ARE POSSIBLE ALONG/SOUTH OF COLD FRONT ACROSS THE FL PENINSULA. IN THE WEST...THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF NORTHERN/CENTRAL CA AND ORE/WA INTO THE INTERMOUNTAIN WEST IN ASSOCIATION WITH UPPER TROUGH ALONG THE WEST COAST. OTHERWISE...DRY/STABLE CONDITIONS WILL PRECLUDE THUNDERSTORMS ACROSS THE REMAINDER OF THE CONUS. ...SOUTH FL... SCATTERED THUNDERSTORM CLUSTERS CONTINUE THIS MORNING ALONG/SOUTH OF COLD FRONT ROUGHLY BISECTING THE FL PENINSULA AND ADJACENT COASTAL WATERS. AS THE FRONT SLOWLY PROGRESSES SOUTHWARD...SCATTERED THUNDERSTORMS WILL FURTHER INCREASE IN COVERAGE ACROSS SOUTH FL...WITH POTENTIAL FOR AT LEAST ISOLATED SEVERE STORMS THROUGH THE AFTERNOON/EARLY EVENING. MODEST INSOLATION COUPLED WITH A RATHER MOIST/UNSTABLE AIRMASS WILL YIELD MLCAPE VALUES OF 1500-2000 J/KG BY THE AFTERNOON ACROSS SOUTH FL...PER MODIFIED 12Z MIAMI/KEY WEST/TAMPA BAY MORNING RAOBS. ALTHOUGH SOMEWHAT NEGATED BY MODEST VERTICAL SHEAR/UNIDIRECTIONAL WIND PROFILES WITHIN THE AMBIENT WARM SECTOR...THERMODYNAMIC CHARACTERISTICS WILL SUPPORT THE POTENTIAL FOR DAMAGING WIND GUSTS AND/OR LARGE HAIL WITH THE STRONGEST STORMS. ..GUYER/HART.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 16:11:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 12:11:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091608 SWODY1 SPC AC 091606 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 AM CDT SUN APR 09 2006 VALID 091630Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FLORIDA... ...SOUTH FLORIDA... THE TAIL END OF THE TROUGH NOW MOVING OFF THE E COAST WILL SLOWLY DRAG ACROSS FL TODAY. S FL 12Z SOUNDINGS REFLECT THE APPROACHING TROUGH WITH MID LEVEL LAPSE RATES OF 7C/KM AND UPWARDS OF 40KT OF DEEP LAYER SHEAR. ADDITIONALLY THE SWLY FLOW HAS SPREAD A MARITIME TROPICAL AIR MASS INLAND TO S OF THE COLD FRONT WHICH CURRENTLY EXTENDS E/W JUST S OF A MLB TO TPA LINE. WITH SFC TEMPS CURRENTLY IN THE MID 80S AND DEWPOINTS HOLDING NEAR 70F SERN FL... CONVECTIVE INHIBITION IS GONE AND MLCAPES HAVE CLIMBED TO ABOVE 2000 J/KG. STRONG/SEVERE THUNDERSTORMS WILL INITIATE VICINITY SUBTLE SURFACE BOUNDARIES SUCH AS S COAST SEA BREEZE AND CURRENT CONVECTIVE COMPLEX PROPAGATING SWD ALONG E COAST. ADDITIONAL STORMS WILL THEN DEVELOP THRU THE AFTERNOON IN RESPONSE TO CONVECTIVE BOUNDARIES THAT EMANATE FROM INITIAL ACTIVITY PRIMARY CONVECTIVE MODE WILL BE MULTI-CELL GIVEN THE WEAK LOW LEVEL SHEAR...HOWEVER ROTATING STORMS ARE POSSIBLE WITH THE FAVORABLE THERMODYNAMICS AND MDT DEEP LAYER SHEAR. LARGE HAIL AND DOWNBURSTS WINDS ARE LIKELY WITH STRONGEST ACTIVITY. ..HALES/GRAMS.. 04/09/2006  From SwoDy1 at goshenarc.org Sun Apr 9 19:51:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 15:51:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091949 SWODY1 SPC AC 091947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SUN APR 09 2006 VALID 092000Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTH FLORIDA... ...SOUTH FLORIDA... 19Z SURFACE ANALYSIS SHOWED THE COLD FRONT EXTENDED FROM 35 SSE VRB WWD TO NRN PART OF LAKE OKEECHOBEE...THEN WNWWD TO THE FL GULF COAST NEAR SRQ BEFORE EXTENDING WWD INTO THE GULF. VIS IMAGERY SHOWED A COUPLE OF OUTFLOW BOUNDARIES OVER S FL...ONE NEAR THE S FL COAST AND THE SECOND LOCATED TO THE E AND S OF LAKE OKEECHOBEE. THESE BOUNDARIES AND OTHER CONVECTIVE OUTFLOW/SEA-LAKE BREEZE BOUNDARIES WILL BE THE FOCI FOR ADDITIONAL ACTIVITY THIS AFTERNOON INTO THE EVENING. MID AFTERNOON SATELLITE/RADAR IMAGERY AND LIGHTNING DATA INDICATED TWO LARGER CLUSTERS OF STORMS /1. ALONG/OFF THE SERN FL COAST AND 2. OVER THE SERN GULF TO THE W/SW OF KEY WEST MOVING GENERALLY SWD/. MORE RECENT THUNDERSTORM DEVELOPMENT WAS NOTED ALONG THE COLD FRONT. CIRRUS SHIELD ASSOCIATED WITH THE SERN GULF CLUSTER TEMPORARILY DECREASED SURFACE HEATING ACROSS PARTS OF S/SW FL EARLIER THIS AFTERNOON. HOWEVER...MORE RECENT TREND OF THINNING CLOUD SHIELD WILL ALLOW ADDITIONAL INSOLATION TO MAINTAIN A MODERATELY UNSTABLE /MLCAPE AOA 1500 J/KG/ WARM SECTOR. UNIDIRECTIONAL WINDS AND DEEP LAYER SHEAR AOB 25 KT WILL CONTINUE TO SUPPORT MULTICELLS WITH HAIL/ STRONG WIND GUSTS AS THE PRIMARY THREATS INTO THE EVENING...AS THE COLD FRONT MOVES SWD ACROSS S FL. ..PETERS.. 04/09/2006  From SwoDy1 at goshenarc.org Mon Apr 10 00:49:32 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 09 Apr 2006 20:49:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100046 SWODY1 SPC AC 100045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0745 PM CDT SUN APR 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...S FL... SURFACE COLD FRONT /JUST N OF LAKE OKEECHOBEE AS OF 00Z/ WILL CONTINUE TO SAG SWD TONIGHT IN WAKE OF MID LEVEL TROUGH SHIFTING EWD INTO THE WRN ATLANTIC. TSTM ACTIVITY OCCURRING ALONG FRONT AND ADDITIONAL PRE-FRONTAL MESOSCALE OUTFLOW BOUNDARIES CONTINUE TO WEAKEN THIS EVENING OWING TO COOLING AND SLOW STABILIZATION OF BOUNDARY-LAYER...AND PASSAGE OF STRONGER LARGE-SCALE FORCING TO THE E. 00Z MIA SOUNDING DID INDICATE THAT AIR MASS REMAINS MODESTLY UNSTABLE OVER FAR S FL AND ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE THROUGH THE EVENING. GUSTY WINDS MAY ACCOMPANY ANY STORMS THAT DEVELOP...THOUGH IT APPEARS THAT THE SEVERE WEATHER THREAT HAS DIMINISHED SUFFICIENTLY SUCH THAT INDIVIDUAL PROBABILITIES WILL BE REMOVED FROM THE FORECAST. ..MEAD.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 05:29:00 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 01:29:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100525 SWODY1 SPC AC 100524 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 AM CDT MON APR 10 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FLATTENING OF WRN CONUS LONG WAVE TROUGH IS FORECAST THROUGH THE DAY ONE PERIOD AS SHORT WAVE TROUGH NOW FROM ERN ORE SWD INTO WRN NV DE-AMPLIFIES WHILE LIFTING NEWD THROUGH THE NRN HIGH PLAINS INTO S-CNTRL CANADA. MEANWHILE...UPSTREAM SHORT WAVE TROUGH /CURRENTLY DIGGING SWD NEAR 35N AND 129 W/ WILL TURN MORE EWD ACROSS THE LOWER CO VALLEY AND INTO THE 4-CORNERS REGION BY TUESDAY MORNING. IN THE LOW-LEVELS...CURRENT SURFACE DATA SHOW LEE CYCLOGENESIS IN PROGRESS OVER THE NRN AND CNTRL HIGH PLAINS...AND THIS PROCESS WILL CONTINUE THROUGH THE DAY WITH MAIN SURFACE LOW CONSOLIDATING OVER NERN WY BY LATE AFTERNOON. THIS LOW WILL THEN DEVELOP NEWD INTO THE RED RIVER VALLEY TONIGHT...IN ADVANCE OF SHORT WAVE TROUGH EJECTING ACROSS THE REGION. MEANWHILE...ASSOCIATED WARM FRONT WILL CONCURRENTLY LIFT NWD THROUGH THE NRN PLAINS AND UPPER MS VALLEY WHILE TRAILING COLD FRONT PUSHES EWD OUT OF THE NRN ROCKIES INTO THE DAKOTAS AND NEB. ...ERN MT / NERN WY EWD INTO THE DAKOTAS AND NRN MN... GOES PW LOOP AND SURFACE DATA INDICATE THAT AIR MASS ACROSS THE PLAINS REMAINS QUITE DRY WITH DEWPOINTS LARGELY IN THE 30 AND 40S. LITTLE INCREASE IN LOW-LEVEL MOISTURE IS FORECAST AND THIS WILL LIMIT A MORE ORGANIZED SEVERE WEATHER THREAT THIS AFTERNOON INTO OVERNIGHT. NONETHELESS...DAYTIME HEATING COUPLED WITH HEIGHT FALLS AHEAD OF SHORT WAVE TROUGH WILL CONTRIBUTE TO THE DEVELOPMENT OF STEEP LAPSE RATES AND RESULTANT WEAK INSTABILITY LATER TODAY AHEAD OF DEVELOPING SURFACE LOW AND TRAILING COLD FRONT. TSTM DEVELOPMENT WILL BECOME INCREASINGLY LIKELY BY MID TO LATE AFTERNOON ALONG OR PERHAPS IN IMMEDIATE WAKE OF COLD FRONT OVER ERN MT SWD INTO NERN WY. THIS ACTIVITY WILL LIKELY MOVE/DEVELOP EWD OR NEWD INTO PORTIONS OF WRN SD AND WRN/CNTRL ND THIS EVENING...PRIOR TO WEAKENING. POTENTIAL WILL EXIST FOR A FEW LOCALLY STRONG WIND GUSTS AND MARGINALLY SEVERE HAIL GIVEN THE STEEP LAPSE RATES...MODEST DEEP-LAYER SHEAR AND DRY SUB-CLOUD CONDITIONS. ADDITIONAL MORE ELEVATED STORMS WILL BE POSSIBLE OVERNIGHT N OF SURFACE WARM FRONT OVER THE RED RIVER VALLEY EWD ACROSS FAR NRN MN. THE STEEP MID LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 500-700 J/KG MAY SUPPORT SOME HAIL WITH THE MOST INTENSE STORMS. ..MEAD/CROSBIE.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 12:26:19 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 08:26:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101223 SWODY1 SPC AC 101222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0722 AM CDT MON APR 10 2006 VALID 101300Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN HIGH PLAINS... MORNING WATER VAPOR IMAGERY SHOWS LARGE SCALE TROUGH DEVELOPING OVER THE WESTERN UNITED STATES...WITH UPPER RIDGE CONTINUING OVER THE SOUTHERN PLAINS AND MS VALLEY. ONE STRONG SHORTWAVE TROUGH IS CURRENTLY OVER ID/UT. THIS FEATURE IS FORECAST TO ROTATE EASTWARD INTO PARTS OF MT/WY AND THE DAKOTAS THIS EVENING. SURFACE LOW IS EXPECTED TO DEEPEN IN ADVANCE OF THIS FEATURE OVER WESTERN SD...RESULTING IN STRENGTHENING SOUTHERLY LOW LEVEL FLOW OVER THE NORTHERN PLAINS. THIS WILL HELP TO DRAW MEAGER LOW LEVEL MOISTURE INTO REGION. STRONG DAYTIME HEATING FROM THE BLACK HILLS REGION INTO EASTERN MT WILL PROVIDE STEEP LAPSE RATES AND MARGINAL AFTERNOON INSTABILITY /MLCAPE BELOW 1000 J/KG/. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP IN THIS REGION BY LATE AFTERNOON. COLD TEMPERATURES ALOFT...STEEP LAPSE RATES...AND SUFFICIENT WIND FIELDS WILL POSE A RISK OF ISOLATED STRONG STORMS CAPABLE OF GUSTY WINDS AND HAIL. ORGANIZED SEVERE STORMS ARE NOT EXPECTED TODAY. ISOLATED STRONG STORMS MAY SPREAD NORTHEASTWARD INTO PARTS OF ND/MN OVERNIGHT WITH A CONTINUED THREAT OF HAIL. ELSEWHERE...NO ORGANIZED SEVERE STORMS ARE ANTICIPATED TODAY. ..HART/CROSBIE.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 16:38:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 12:38:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101632 SWODY1 SPC AC 101630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT MON APR 10 2006 VALID 101630Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN PLAINS... WHILE PRIMARY TROUGH REMAINS ALONG OR JUST OFF W COAST A BROAD SWLY FLOW WITH EMBEDDED S/WVS EXTENDS EWD INTO THE NRN PLAINS. ONE IMPULSE CURRENTLY NRN ROCKIES WITH UPSTREAM IMPULSE MOVING INLAND SRN CA THIS AFTERNOON. SURFACE LOW NERN WY THIS AM WITH A STRONG SLY LOW LEVEL JET TO THE E OVER THE PLAINS. LOW WILL MOVE NEWD ACROSS DAKOTAS TOWARD NWRN MN BY LATE TONIGHT. VERY LIMITED MOISTURE WITH THIS SYSTEM...HOWEVER THE COMBINATION OF STEEP LAPSE RATES...8C/KM OR GREATER AND LARGE SCALE ASCENT AHEAD OF SURFACE LOW AND S/WV TROUGH DOES SUPPORT CONVECTIVE POTENTIAL BY THIS EVENING. HIGH CLOUDS CURRENTLY WRN DAKOTAS EXPECTED TO ADVECT EWD AND ALLOW FULL HEATING THIS AFTERNOON. BY LATE AFTERNOON WITH TEMPERATURES INTO THE 70S AND DEWPOINTS MID 40S MINIMAL CINH AND MLCAPES TO 500 J/KG WOULD BE AVAILABLE NWRN SD/SWRN ND. THIS WOULD SUPPORT DEVELOPMENT OF HIGH BASED CONVECTION IN AREA OF BEST LOW LEVEL CONVERGENCE. WHILE THERMODYNAMICS WILL BE MARGINAL...THERE WOULD BE POTENTIAL FOR STRONG WIND GUSTS AND MARGINAL HAIL THIS REGION THRU THE EVENING. STORMS EXPECTED TO BECOME ELEVATED OVERNIGHT AS THEY MOVE ACROSS ND INTO NRN MN WITH STRONG LOW LEVEL JET AND SOME ELEVATED INSTABILITY CONTINUING RISK OF MARGINAL HAIL AS FAR E AS NWRN MN. ...SRN FL... HAVE ADDED LOW PROBS OF HAIL AS AIRMASS REMAINS UNSTABLE WITH RELATIVELY STEEP MID LEVEL LAPSE RATES. SHEAR LESS THAN 25 KTS SUPPORT MULTI-CELLS WITH STRONGER UPDRAFTS SUPPORTING SOME HAIL POTENTIAL UNTIL THIS EVENING. ..HALES/GRAMS.. 04/10/2006  From SwoDy1 at goshenarc.org Mon Apr 10 19:48:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 15:48:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101945 SWODY1 SPC AC 101944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT MON APR 10 2006 VALID 102000Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...NRN HIGH PLAINS THROUGH NRN MN... MOISTURE REMAINS LIMITED OVER THE NRN HIGH PLAINS WITH DEWPOINTS GENERALLY IN THE UPPER 30S TO AROUND 40. STEEP MID LEVEL LAPSE RATES AND COLD MID LEVEL TEMPERATURES ASSOCIATED WITH SHORTWAVE TROUGH ADVANCING NEWD THROUGH THE NRN ROCKIES EXIST ABOVE THE MODEST LOW LEVEL MOISTURE. THIS IN CONJUNCTION WITH STRONG SURFACE HEATING WILL CONTRIBUTE TO MLCAPE ON THE ORDER OF 500 TO 800 J/KG ACROSS PARTS OF SERN MT...NWRN SD AND SWRN ND. AS THE SHORTWAVE TROUGH LIFTS NEWD THIS AFTERNOON...A COLD FRONT WILL ADVANCE EWD INTO THE NRN HIGH PLAINS. THE ATMOSPHERE IS STILL CAPPED IN MUCH OF THIS REGION AS OF MID AFTERNOON. HOWEVER...HEATING AND BOUNDARY LAYER MIXING AS WELL AS LARGE SCALE ASCENT ACCOMPANYING THE SHORTWAVE TROUGH SHOULD CONTRIBUTE TO HIGH BASED THUNDERSTORMS. VERTICAL SHEAR SUPPORTIVE OF UPDRAFT ROTATION AND STEEP LAPSE RATES WILL PROMOTE A THREAT FOR HAIL. STEEP LOW LEVEL LAPSE RATES AND DEEP MIXED BOUNDARY LAYERS ALSO SUGGEST ISOLATED STRONG WIND GUSTS MAY ACCOMPANY SOME STORMS THROUGH EARLY EVENING. OTHER STORMS MAY DEVELOP FARTHER NE ACROSS NRN ND INTO NRN MN LATER TONIGHT IN ZONE OF STRENGTHENING WARM ADVECTION WITH A THREAT OF ISOLATED MARGINALLY SEVERE HAIL. LOW LEVEL MOISTURE AND INSTABILITY DO NOT APPEAR SUFFICIENT TO WARRANT MORE THAN LOW PROBABILITIES. ...SRN FL... ISOLATED MARGINALLY SEVERE HAIL AND STRONG WIND GUSTS ASSOCIATED WITH MULTICELL STORMS REMAIN POSSIBLE OVER THE EXTREME SRN TIP OF FL INTO THE FL KEYS THIS AFTERNOON. MOST OF THIS AREA IS IN THE PROCESS OF BEING OVERTURNED...AND THE THREAT SHOULD DIMINISH WITHIN THE NEXT 1 TO 2 HOURS. ..DIAL.. 04/10/2006  From SwoDy1 at goshenarc.org Tue Apr 11 00:42:12 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 10 Apr 2006 20:42:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110039 SWODY1 SPC AC 110037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0737 PM CDT MON APR 10 2006 VALID 110100Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...ND INTO NRN MN... RECENT TRENDS IN LIGHTNING DATA INDICATE TSTMS INCREASING IN COVERAGE ACROSS WRN ND INTO FAR NWRN SD IN ADVANCE OF SHORT WAVE TROUGH LIFTING NEWD THROUGH WY INTO SERN MT. THIS ACTIVITY IS OCCURRING ALONG A COLD FRONT OR INVERTED TROUGH EXTENDING FROM NEAR THE MT/ND BORDER SEWD TO LOW PRESSURE OVER N-CNTRL SD. DESPITE RELATIVELY DRY BOUNDARY-LAYER CONDITIONS...DAYTIME HEATING COUPLED WITH HEIGHT FALLS AHEAD OF AFOREMENTIONED SHORT WAVE TROUGH HAVE CONTRIBUTED TO THE DEVELOPMENT OF STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY /REF. 00Z RAP SOUNDING/. THIS ACTIVITY WILL LIKELY PERSIST THROUGH THE EVENING ACROSS WRN AND CNTRL ND WITH SOME POTENTIAL FOR LOCALLY STRONG WIND GUSTS AND/OR MARGINALLY SEVERE HAIL. FARTHER TO THE E...00Z ABR SOUNDING SHOWED A WELL DEFINED ELEVATED MIXED LAYER WITH A STRONG CAP AT THE BASE OF THIS FEATURE. GIVEN THAT BOUNDARY-LAYER WILL SLOWLY COOL OVERNIGHT...DEEP MOIST CONVECTION APPEARS UNLIKELY S OF SURFACE LOW ALONG COLD FRONT INTO CNTRL SD. BETTER NOCTURNAL POTENTIAL APPEARS TO BE N OF WARM FRONT /CURRENTLY EXTENDING FROM THE SURFACE LOW EWD THROUGH SERN ND INTO WRN LAKE SUPERIOR/ WHERE INCREASING LOW-LEVEL WAA MAY SUPPORT ELEVATED TSTM DEVELOPMENT. GIVEN THE PRESENCE OF THE STEEP MID-LEVEL LAPSE RATES OBSERVED ON THE 00Z SOUNDINGS...THREAT FOR SOME MARGINALLY SEVERE HAIL WILL EXIST FROM N-CNTRL/NERN ND EWD ACROSS NRN MN OVERNIGHT. ..MEAD.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 05:59:37 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 01:59:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110556 SWODY1 SPC AC 110555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE APR 11 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER THE MID MO VALLEY... ...SYNOPSIS... SHORT WAVE TROUGH NOW MOVING THROUGH THE LOWER CO VALLEY WILL CONTINUE NEWD TODAY INTO THE CNTRL PLAINS...AND EVENTUALLY INTO THE MIDWEST TONIGHT. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH LEAD DISTURBANCE OVER THE DAKOTAS WILL DEVELOP NEWD INTO ONTARIO WITH SECONDARY CYCLOGENESIS FORECAST ALONG TRAILING COLD FRONT OVER NRN KS. THIS SECONDARY LOW WILL THEN RAPIDLY DEVELOP NEWD INTO THE WRN GREAT LAKES BY WEDNESDAY MORNING. ...MID MO VALLEY... 11/00Z REGIONAL SOUNDINGS INDICATED THAT LOW-LEVEL MOISTURE REMAINS QUITE LIMITED NWD THROUGH THE GREAT PLAINS WITH THE PRESENCE OF A WELL DEFINED ELEVATED MIXED LAYER /EML/ AND ASSOCIATED STRONG CAP OVER THE LOWER PLAINS. PERSISTENT...STRONG SLY LOW-LEVEL FLOW AHEAD OF THE SECONDARY LOW AND ASSOCIATED FRONT WILL ALLOW FOR SOME INCREASE IN BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA WITH AFTERNOON DEWPOINTS IN THE UPPER 40S TO AROUND 50 F. WHEN COUPLED WITH DAYTIME HEATING...PRE-FRONTAL AIR MASS IS EXPECTED TO BECOME WEAKLY TO MODERATELY UNSTABLE WITH SBCAPES OF 500-1000 J/KG. STRONG CAPPING WILL LIKELY SUPPRESS SURFACE-BASED STORM DEVELOPMENT ACROSS SLIGHT RISK AREA THROUGH MUCH OF THE AFTERNOON...WITH INITIAL STORMS FORMING FARTHER TO THE N OVER MN. HOWEVER...SUSTAINED LOW-LEVEL CONVERGENCE COMBINED WITH INCREASING HEIGHT FALLS/FORCING AHEAD OF APPROACHING SHORTWAVE TROUGH SHOULD SUPPORT SWWD DEVELOPMENT INTO ERN NEB/WRN IA PERHAPS INTO N-CNTRL/NERN KS. FORECAST SOUNDINGS INDICATE SOME LOW-LEVEL HODOGRAPH CURVATURE WITH 40-50 KTS OF WSWLY MID-LEVEL FLOW WHICH WILL BE SUPPORTIVE OF A FEW ORGANIZED/ROTATING STORMS. GIVEN THE PRESENCE OF THE EML AND RESULTANT STEEP-LAPSE RATES...SEVERE HAIL APPEARS LIKELY WITH THE STRONGEST STORMS...IN ADDITION TO ISOLATED STRONG WIND GUSTS. STRENGTHENING LOW-LEVEL WAA SHOULD SUSTAIN STORM CLUSTERS OR A MCS OVERNIGHT EWD ACROSS IA/SRN MN WITH A CONTINUING POTENTIAL FOR GUSTY WINDS AND PERHAPS SOME MARGINALLY SEVERE HAIL. ..MEAD/CROSBIE.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 12:20:01 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 08:20:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111217 SWODY1 SPC AC 111215 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0715 AM CDT TUE APR 11 2006 VALID 111300Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF NEB...KS...IA...AND MO.... ...MO VALLEY... STRONG SHORTWAVE TROUGH SHOWN ON MORNING WATER VAPOR IMAGERY OVER CO IS FORECAST TO MOVE EASTWARD INTO THE CENTRAL PLAINS STATES THIS AFTERNOON. SURFACE LOW ASSOCIATED WITH THIS TROUGH WILL TRACK FROM SOUTHWEST NEB ACROSS IA...WITH COLD FRONT SWEEPING SOUTHWARD INTO KS THIS EVENING. STRONG SOUTHERLY LOW LEVEL WINDS IN WARM SECTOR OF LOW WILL MAINTAIN SURFACE DEWPOINTS IN THE UPPER 40S TO LOWER 50S AHEAD OF LOW...WHERE DEEP-MIXED BOUNDARY LAYER IS FORECAST TO DEVELOP. AFTERNOON MAX MLCAPE VALUES ARE EXPECTED TO REMAIN BELOW 1000 J/KG...WITH STRONG CAPPING INVERSION SHOWN ON MORNING SOUNDINGS LIMITING CONVECTION MOST OF THE DAY. LARGE SCALE FORCING WILL OVERSPREAD PARTS OF NEB/KS/IA/MO DURING THE AFTERNOON...EVENTUALLY ELIMINATING THE CAP AND ALLOWING ISOLATED THUNDERSTORM DEVELOPMENT NEAR SURFACE LOW. FORECAST SOUNDINGS IN THIS REGION SUGGEST FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/SUPERCELL STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. STORMS WILL LIKELY REMAIN HIGH-BASED AND ISOLATED DUE TO MINIMAL INSTABILITY AND CAPPING EFFECTS. ACTIVITY IS FORECAST TO MOVE FROM EASTERN NEB/NERN KS ACROSS NORTHWEST MO AND MUCH OF IA DURING THE EVENING...WITH A SLOW WEAKENING TREND AFTER DARK. ..HART.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 16:34:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 12:34:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111618 SWODY1 SPC AC 111617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CDT TUE APR 11 2006 VALID 111630Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OF THE MID MO RIVER VALLEY... ...CENTRAL PLAINS... SIGNIFICANT MID/UPPER LEVEL TROUGH CONTINUES TO EJECT ENEWD INTO THE CENTRAL HIGH PLAINS THIS MORNING. ACCOMPANYING 50-60 KT WSWLY MID LEVEL JET WILL OVERSPREAD MUCH OF KS AND NOSE ACROSS THE MO RIVER VALLEY EARLY THIS EVENING. THOUGH LARGE SCALE ASCENT WILL BE QUITE IMPRESSIVE WITH THIS SYSTEM...PRIMARY NEGATIVE FOR SEVERE THUNDERSTORMS REMAINS THE LIMITED BOUNDARY LAYER MOISTURE ACROSS THE REGION. MORNING ANALYSES CONTINUE TO INDICATE SFC DEW POINTS AOB 50F FROM FAR NRN OK NNEWD INTO ERN KS/SERN NEB...WITH 55+F DEW POINTS REMAINING SOUTH OF THE RED RIVER. 12Z MODELS ARE NOT CONSISTENT WITH LATE AFTERNOON/EARLY EVENING SFC DEW POINT FORECASTS. THE RUC DEEPLY MIXES/DRIES THE BOUNDARY LAYER WITH SUB-40F DEW POINTS LATER TODAY WHILE THE NAM DEVELOPS SURFACE DEW POINTS 10 DEGREES HIGHER. RESULTANT FORECAST MLCAPE VARIES FROM NEAR ZERO TO AROUND 1000 J/KG. ATTM...EXPECT SFC DEW POINTS AROUND 50F AND MLCAPE OF 500-750 J/KG AHEAD OF DEEPENING SURFACE LOW AND SEWD MOVING COLD FRONT LATER TODAY. GIVEN THE LIMITED INSTABILITY AND EXPECTED CAPPING...INITIATION WILL LIKELY OCCUR LATE IN THE DAY/EARLY THIS EVENING ALONG NOSE OF STRONGEST ASCENT NEAR THE KS/NEB BORDER. DEVELOPMENT SHOULD THEN SPREAD ENEWD AND POSSIBLY BUILD SWD ALONG THE COLD FRONT THROUGH THE MID/LATE EVENING. EFFECTIVE SHEAR IS FORECAST TO REMAIN QUITE STRONG...DESPITE THE HIGH-BASED NATURE OF THE CONVECTION...AND SUPPORT STORM-SCALE ORGANIZATION INTO SMALL LINES/SUPERCELLS. DAMAGING WINDS AND ISOLATED LARGE WILL BE PRIMARY SEVERE THREATS THROUGH THE EARLY EVENING SHOULD STORMS DEVELOP...WITH SEVERE POTENTIAL DIMINISHING AS BOUNDARY LAYER COOLS/DECOUPLES AFTER DARK. ..EVANS/JEWELL.. 04/11/2006  From SwoDy1 at goshenarc.org Tue Apr 11 19:49:40 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 15:49:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111946 SWODY1 SPC AC 111944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT TUE APR 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO VLY EWD INTO THE UPPER MS VLY... UPPER LEVEL DRY SLOT ASSOCIATED WITH THE CNTRL PLAINS SHORTWAVE TROUGH CONTINUES TO SURGE NWD THROUGH THE MID-MO VLY THIS AFTN. BENEATH THIS DRY SLOT...BOUNDARY LAYER MOISTURE HAS MIXED OUT WITH MID-UPPER 40S SFC DEW POINTS COMMON ACROSS NRN KS AND CNTRL NEB...LIMITING POTENTIAL INSTABILITY AHEAD OF THE PRE-FRONTAL TROUGH. SFC LOW OVER ECNTRL NEB SHOULD MOVE NEWD INTO MN THIS EVENING IN TANDEM WITH THE UPPER WAVE. STRONG LOW/MID-LEVEL FRONTOGENESIS OCCURRING ACROSS WRN NEB WILL TRANSLATE ENEWD ACROSS THE MO RVR LATE THIS AFTN AND INTO THE UPPER MS VLY TONIGHT...EVENTUALLY CATCHING THE PRE-FRONTAL TROUGH. GIVEN THE LIMITED INSTABILITY AND CAPPING...TSTMS WILL LIKELY BE CONFINED TO THE ZONE OF STRONGEST ASCENT/FRONTOGENESIS. THIS SCENARIO ALREADY APPEARS TO BE PLAYING OUT ACROSS CNTRL NEB WHERE VSBL SATL SHOWS ENHANCED CONVECTION WITH VIRGA BEING REPORTED VCNTY KLBF. TSTMS MAY BEGIN TO GROW STRONGER WHEN THEY APPROACH THE PRE-FRONTAL TROUGH ACROSS THE MID-MO VLY LATER THIS AFTN WHERE BOUNDARY LAYER MSTR MAY BE SLIGHTLY HIGHER /MLCAPES 250 J PER KG/ AND CINH WEAKER. BUT...THE STORMS SHOULD REMAIN HIGH-BASED ...WITH A NEARLY DRY-ADIABATIC PROFILE TO CLOUD BASE BEFORE THE PRIMARY COLD FRONT UNDERCUTS THE STORMS. THUS...ISOLD DAMAGING WINDS MAY OCCUR LATE THIS AFTN/EVE...BUT PROSPECTS FOR WIDESPREAD SEVERE TSTMS IS NOT ANTICIPATED. TSTMS WILL MOVE ENEWD ACROSS THE UPPER MS VLY OVERNIGHT. ..RACY.. 04/11/2006  From SwoDy1 at goshenarc.org Wed Apr 12 00:47:50 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 11 Apr 2006 20:47:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120044 SWODY1 SPC AC 120043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0743 PM CDT TUE APR 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID-MO VLY NEWD INTO THE UPPER MS VLY... HIGH-BASED TSTMS INITIATED LATE THIS AFTN ACROSS SERN NEB...ERN KS AND SWRN IA ALONG A PRE-FRONTAL TROUGH. THIS REGION EXPERIENCED THE STRONGEST HEATING BENEATH UPPER LEVEL DRY SLOT AND WITHIN EXIT REGION OF A 70-80 KT H5 JET STREAK. 00Z OMAHA SOUNDING EXHIBITED A DEEPLY MIXED BOUNDARY LAYER WITH AROUND 400-500 J/KG MLCAPE. THE STEEP LAPSE RATE ENVIRONMENT...FAVORABLE VERTICAL SHEAR OF 40-50 KTS AND DRY SUB-CLOUD LAYER HAS BEEN SUFFICIENT FOR A FEW MARGINALLY SEVERE HAIL/WIND GUSTS. THE SYNOPTIC COLD FRONT SHOULD STRENGTHEN AND PROGRESS EWD INTO THE UPPER MS VLY OVERNIGHT AS THE UPPER LEVEL JET STREAK/STRONGER LARGE SCALE ASCENT TRANSLATES ENEWD. THE BROKEN LINE OF TSTMS WILL CONTINUE TO EXPAND ENEWD INTO/ACROSS EXTREME NRN MO AND CNTRL IA THIS EVENING AND INTO THE UPPER MS VLY OVERNIGHT. THOUGH TSTMS WILL BE LIKELY ALONG/IMMEDIATELY BEHIND THE FRONT...THE ISOLD SEVERE THREATS SHOULD DIMINISH AS THE STORMS MOVE BEYOND THE LOW-LEVEL THERMAL RIDGE AXIS. ..RACY.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 05:25:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 01:25:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120522 SWODY1 SPC AC 120520 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 AM CDT WED APR 12 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WELL-DEFINED SHORT WAVE TROUGH CURRENTLY MOVING THROUGH THE MIDWEST WILL CONTINUE ENEWD THROUGH THE GREAT LAKES AND OH VALLEY TODAY...EVENTUALLY PHASING WITH FASTER NRN STREAM DISTURBANCE OVER THE NERN STATES TONIGHT. IN THE LOW-LEVELS...SURFACE LOW INITIALLY OVER THE UP OF MI WILL RAPIDLY DEVELOP NEWD INTO QUEBEC WHILE ASSOCIATED COLD FRONT PUSHES EWD THROUGH THE UPPER OH VALLEY INTO WRN NEW ENGLAND. THE TRAILING PORTION OF THIS FRONT WILL MOVE MORE SLOWLY SEWD PRIOR TO STALLING AND UNDERGOING FRONTOLYSIS S OF THE OH RIVER. THIS BOUNDARY WILL ALSO BECOME PROGRESSIVELY ILL-DEFINED WITH TIME OVER THE CNTRL AND SRN PLAINS WITH THE MAIN BAROCLINIC ZONE BECOMING RE-ESTABLISHED FARTHER TO THE N OWING TO STRENGTHENING LEE TROUGH OVER THE NRN HIGH PLAINS. ...OH VALLEY... 12/00Z REGIONAL SOUNDINGS CONTINUE TO INDICATE THAT LOW-LEVEL MOISTURE REMAINS LIMITED ACROSS THE ERN PLAINS AND MS VALLEY WITH UPSTREAM...MEAN MIXING RATIOS COMMONLY BETWEEN 7-9 G/KG. MOREOVER...ONGOING TSTMS OVER IA HAVE LIKELY PROCESSED THE PLUME OF STEEP MID-LEVEL LAPSE RATES WHICH PRECEEDED THE SHORT WAVE TROUGH INTO THE PLAINS. THIS MODEST LOW-LEVEL MOISTURE COUPLED WITH A TENDENCY FOR WEAKER MID-LEVEL LAPSE RATES WILL LIKELY LIMIT A MORE ORGANIZED SEVERE THREAT LATER TODAY ACROSS REGION. A PRE-FRONTAL CLUSTER OF TSTMS SHOULD BE ONGOING AT THE START OF THE FORECAST PERIOD OVER THE MIDWEST...WITH ACTIVITY CONTINUING EWD THROUGH THE SRN GREAT LAKES AND OH VALLEY TODAY. NO SEVERE WEATHER IS EXPECTED WITH THESE STORMS OWING TO THE WEAK INSTABILITY. MORE VIGOROUS TSTM DEVELOPMENT IS ANTICIPATED BY MID TO LATE AFTERNOON ALONG FRONT OVER ERN IND OR OH WITHIN MARGINALLY UNSTABLE ENVIRONMENT CHARACTERIZED BY SBCAPES OF AROUND 500 J/KG. SUBSEQUENT STORM DEVELOPMENT WILL BE POSSIBLE SWWD ALONG FRONT NEAR OR S OF THE OH RIVER FROM LATE AFTERNOON INTO EARLY EVENING. FORECAST SHEAR PROFILES ARE EXPECTED TO BE QUITE SUPPORTIVE OF ORGANIZED/ROTATING STORMS WITH SWLY SURFACE WINDS VEERING TO WNWLY AT 50 KTS IN THE MID-LEVELS. WHILE THE MOST INTENSE STORMS WILL BE CAPABLE OF LOCALLY STRONG WIND GUSTS AND SOME MARGINALLY SEVERE HAIL...A MORE SUBSTANTIAL SEVERE WEATHER THREAT WILL LIKELY BE LIMITED BY THE WEAK INSTABILITY. ..MEAD/TAYLOR.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 12:33:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 08:33:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121230 SWODY1 SPC AC 121228 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0728 AM CDT WED APR 12 2006 VALID 121300Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY EVENING ACROSS PARTS OF LOWER MI AND OH.... ...GREAT LAKES/OH VALLEY... LATEST SATELLITE IMAGERY SHOWS VIGOROUS UPPER SHORTWAVE TROUGH OVER WI/IL. THIS FEATURE WILL MOVE EASTWARD ACROSS THE GREAT LAKES REGION AND UPPER OH VALLEY. MORNING SURFACE ANALYSIS INDICATES A SURFACE LOW OVER UPPER MI...WITH TRAILING COLD FRONT EXTENDING ACROSS WI...CENTRAL IL...AND CENTRAL MO. MULTIPLE BANDS OF PRE-FRONTAL CONVECTION ARE NOTED AHEAD OF FRONT ACROSS THE OH VALLEY. THIS ACTIVITY IS EXPECTED TO MOVE EASTWARD AND WEAKEN...ALLOWING PORTIONS OF MI/IND/OH TO HEAT SUBSTANTIALLY THROUGH THE DAY. SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT WILL TRANSPORT MOISTURE NORTHWARD INTO THIS REGION WITH AFTERNOON DEWPOINTS IN THE UPPER 40S TO LOWER 50S. PRESENT INDICATIONS ARE THAT THUNDERSTORMS WILL RE-DEVELOP BY EARLY AFTERNOON ALONG COLD FRONT OVER SOUTHERN LOWER MI...EASTERN IND...AND WESTERN OH. THIS ACTIVITY SHOULD SPREAD EASTWARD ACROSS OH AND INTO PARTS OF WESTERN PA/NORTHWESTERN WV BY EARLY EVENING. MODEL FORECAST SOUNDINGS ACROSS THIS REGION SHOW VERY STRONG WESTERLY WIND FIELDS ALOFT...COUPLED WITH STEEP LAPSE RATES AND AT LEAST MARGINAL INSTABILITY. THIS APPEARS FAVORABLE FOR A RISK OF ISOLATED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. STORMS SHOULD WEAKEN AS THEY MOVE INTO INCREASINGLY STABLE AIR MASS OVER PA/WV. ..HART/TAYLOR.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 16:12:05 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 12:12:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121603 SWODY1 SPC AC 121601 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CDT WED APR 12 2006 VALID 121630Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF LOWER MI... MUCH OF OH AND NWRN PA... ...GREAT LAKES/OHIO VALLEY... PRONOUNCED LOW/MID LEVEL TROUGH EVIDENCED BY CYCLONIC SWIRL IN VSB CLOUD PATTERN MOVING ACROSS SRN LM INTO WRN LWR MI. COLD FRONT MOVING INTO WRN LM TRAILS SWWD ACROSS NRN IND INTO NRN OK. CURRENT ELEVATED CONVECTION DRIVEN BY WARM ADVECTION AND LARGE SCALE ASCENT AHEAD OF TROUGH CONTINUES EWD ACROSS NRN OH WITH SOME CLEARING IN ITS WAKE. HEATING AHEAD OF COLD FRONT INTO WRN OH DURING AFTERNOON WILL STEEPEN LAPSE RATES WHICH ALONG WITH INCREASE IN LOW LEVEL MOISTURE PROVIDES FOR DEVELOPMENT OF MODEST INSTABILITY. NAM APPEARS TOO AGGRESSIVE ON LOW LEVEL MOISTURE WITH THE RUC MORE REASONABLE AS DEWPONTS RISE INTO THE MID 50S ACROSS OH BY MID/LATE AFTERNOON AHEAD OF FRONT. BY MID AFTERNOON WITH SURFACE TEMPERATURES WARMING INTO THE MID 70S AND DEWPOINTS INTO MID 50S...MLCAPES WILL RANGE UPWARDS AHEAD OF COLD FRONT TO POSSIBLY 1000 J/KG CENTRAL OH. FOECASTED 30KT OF LOW LEVEL SHEAR AND DEEPLY MIXED BOUNDARY LAYER...THUNDERSTORMS SHOULD DEVELOP BY MID AFTERNOON FROM SERN CORNER MI SWD INTO WRN OH WITH POTENTIAL OF DAMAGING WINDS AND MARGINALLY SEVERE HAIL. STORMS SHOULD EVOLVE INTO A LINEAR MODE QUICKLY GIVEN LIMITED CAPE AND STRONG SHEAR. POTENTIAL OF DAMAGING WINDS SHOULD DECREASE EWD THIS EVENING AS STORMS ENCOUNTER DECREASING INSTABILITY WRN PA. ..HALES/JEWELL.. 04/12/2006  From SwoDy1 at goshenarc.org Wed Apr 12 20:01:25 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 16:01:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121958 SWODY1 SPC AC 121956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT WED APR 12 2006 VALID 122000Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ... ...NRN/CENTRAL OH INTO NWRN PA... AREA OF SHALLOW CONVECTION CONTINUES TO INTENSIFY AT 20Z INTO FAR SWRN ONTARIO AHEAD OF STRONG UPPER SYSTEM AND ASSOCIATED SURFACE COLD FRONT. INSTABILITY HAS REMAINED MINIMAL TODAY AHEAD OF THIS FRONT WITH SURFACE DEW POINTS IN THE LOWER 50S AND SBCAPE AOB 500 J/KG. HOWEVER...CONTINUED HEATING AND SMALL INCREASES IN SURFACE DEW POINTS INTO NERN OH SHOULD ALLOW ACTIVITY TO DEVELOP GRADUALLY SWD ALONG THE FRONT ACROSS NRN OH THROUGH THE EVENING. SHEAR REMAINS QUITE STRONG...DESPITE VEERED/SWLY SURFACE WINDS...AND SHOULD SUPPORT ORGANIZATION INTO SMALL LINES OR LOW-TOPPED SUPERCELLS. WIND DAMAGE AND MARGINALLY SEVERE HAIL SHOULD BE PRIMARY SEVERE THREATS AS THIS HIGH-BASED ACTIVITY MOVES ENEWD THROUGH THE EARLY TO MID EVENING. AN ISOLATED TORNADO WILL ALSO REMAIN POSSIBLE... ESPECIALLY NEAR LAKE ERIE WHERE LOW LEVEL HODOGRAPHS REMAIN LARGE. ...NRN AR... MODEST SURFACE CONVERGENCE CONTINUES ALONG STALLED SURFACE FRONT EXTENDING E-W ACROSS NRN AR/FAR SRN MO THIS AFTERNOON. SOUTH OF THIS BOUNDARY MLCAPE HAS INCREASED TO NEAR 1000 J/KG WITH WEAK CAP.. COMBINATION OF WHICH IS SUPPORTING ISOLATED THUNDERSTORM DEVELOPMENT. FORECAST SOUNDINGS REVEAL EFFECTIVE BULK-SHEAR OF 35 KT...MARGINALLY SUPPORTIVE OF SUPERCELLS WITHIN THIS AMOUNT OF INSTABILITY. THUS...STRONGER STORMS MAY BECOME CAPABLE OF ISOLATED/BRIEF DAMAGING WIND AND LARGE HAIL THREAT. ANY SEVERE THREAT SHOULD DIMINISH AFTER DARK. ...NRN MN... ANOTHER STRONG MID/UPPER LEVEL SYSTEM IS WELL DEFINED MOVING ACROSS SERN MANITOBA AND FAR WRN ONTARIO THIS AFTERNOON. COLD AIR ALOFT AND MARGINAL INSTABILITY/STEEP LAPSE RATES MAY SUPPORT HAIL WITH THE STRONGER CORES...THOUGH OVERALL SEVERE THREAT EXPECTED TO REMAIN MINIMAL. ..EVANS.. 04/12/2006  From SwoDy1 at goshenarc.org Thu Apr 13 00:56:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 12 Apr 2006 20:56:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130052 SWODY1 SPC AC 130050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 PM CDT WED APR 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER AIR PATTERN WILL CONTINUE TO FEATURE BROAD AREA OF HIGH HEIGHTS ACROSS S-CENTRAL CONUS...GREAT PLAINS AND CENTRAL/SRN ROCKIES. CUT-OFF UPPER LOW WILL CONTINUE TO MENDER ERRATICALLY OFFSHORE CA. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN ONT AND ERN GREAT LAKES REGION -- IS FCST TO MOVE EWD OVER PORTIONS SWRN QUE AND MID-ATLANTIC REGION OVERNIGHT. ASSOCIATED SFC COLD FRONT IS ANALYZED FROM NWRN NY TO CENTRAL OH...SRN IL...SRN MO...BECOMING QUASISTATIONARY FROM OZARKS WSWWD ACROSS NRN OK. FRONT SHOULD MOVE EWD ACROSS MID ATLANTIC REGION THROUGH REMAINDER PERIOD...WHILE LIFTING NWD OVER CENTRAL PLAINS AND MO. ...UPPER OH VALLEY REGION... LINE OF SCATTERED TSTMS -- SOME OF WHICH REMAIN AT LEAST MARGINALLY SEVERE...SHOULD CONTINUE TO MOVE EWD ACROSS REMAINDER SERN OH...WRN PA...AND NRN PANHANDLE OF WV. ACTIVITY FARTHER NE ACROSS WRN UPSTATE NY HAS WEAKENED IN MORE STABLE ENVIRONMENT...A TREND THAT SHOULD SHIFT SWD WITH TIME THROUGH CONVECTIVE BAND. SFC ANALYSIS SHOWS THETAE DECREASING WITH EWD EXTENT ACROSS REGION...ANOTHER TENDENCY THAT WILL CONTINUE THROUGH REMAINDER EVENING...DESPITE NARROW PLUME OF BOUNDARY LAYER MOIST ADVECTION JUST AHEAD OF THIS ACTIVITY. AS RELATIVELY DRY AIR MASS DIABATICALLY COOLS...DECOUPLING SFC LAYER...INFLOW REGION SHOULD BECOME PROGRESSIVELY MORE ELEVATED AND LESS UNSTABLE. THEREFORE...SEVERE POTENTIAL IS EXPECTED TO DIMINISH FROM N TO S...AND WITH TIME. ...NRN AR... ISOLATED CLUSTER OF STRONG TO MARGINALLY SEVERE MULTICELLS IS EVIDENT IN ENVIRONMENT OF WEAK LOW LEVEL FLOW...BUT CONSIDERABLE VEERING OF WINDS WITH HEIGHT. ACTIVITY MAY CONTINUE TO BACKBUILD ALONG WRN EDGE FOR ANOTHER COUPLE HOURS...BEFORE DIMINISHING WITH LOSS OF DIURNAL HEATING IN SFC-BASED INFLOW LAYER. HAIL/GUSTS NEAR SEVERE LEVELS REMAINS POSSIBLE BUT THREAT SHOULD DROP MARKEDLY AFTER ABOUT 13/03Z. ..EDWARDS.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 05:03:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 01:03:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130459 SWODY1 SPC AC 130458 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CDT WED APR 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY REGION TO PORTIONS NRN/WRN OH... ...SYNOPSIS... BASIC SYNOPTIC PATTERN WILL BE DOMINATED BY NEARLY ZONAL NRN STREAM FROM PACIFIC NW TO UPPER GREAT LAKES...HEIGHT FALLS DOWNSTREAM OVER NEW ENGLAND...AND BROAD SWATH OF MID/UPPER LEVEL RIDGING ACROSS MOST OF SRN CONUS. LOW-AMPLITUDE SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER BC AND WA -- IS FCST TO MOVE QUICKLY EWD ALONG AND JUST N OF CANADIAN BORDER...REACHING REGION OF LS NORTH SHORE AND BOUNDARY WATERS OF MN/ONT BY END OF PERIOD. SFC FRONTAL ZONE - NOW MOVING EWD ACROSS OH VALLEY REGION AND NEARLY STATIONARY OVER OZARKS -- IS FCST TO RETREAT/REDEVELOP NEWD ACROSS MID/UPPER MS VALLEY THROUGH THIS PERIOD. WEAK CYCLOGENESIS IS REASONABLY FCST ALONG WRN PORTION OF THIS FRONTAL ZONE -- OVER SRN MN/NRN IA REGION BY 14/00Z. THIS LOW SHOULD SHIFT ESEWD TOWARD SRN LOWER MI OR NWRN OH 12 HOURS THEREAFTER. WEAK COLD FRONT SHOULD EXTEND FROM LOW SWWD ACROSS IA/SERN NEB DURING LATE AFTERNOON. ...UPPER MS VALLEY...UPPER GREAT LAKES REGION... MRGL AND HIGHLY CONDITIONAL SEVERE PROBABILITIES ARE FCST DURING AFTERNOON FROM WARM FRONT SWWD ALONG COLD FRONT. GREATER CONVECTIVE AND SEVERE PROBABILITIES ARE AFTER DARK OVER UPPER MIDWEST...GENERALLY WITHIN ABOUT 250 NM NE OF SFC LOW TRACK. VERTICAL SHEAR PROFILES AND PROGGED BUOYANCY WOULD SUPPORT SUPERCELL THREAT DURING LATE AFTERNOON INVOF SFC LOW...OR JUST E OF LOW ALONG WARM FRONT. HOWEVER...THIS THREAT IS STRONGLY CONDITIONAL BECAUSE OF ANTICIPATED STRONG CAP -- EVEN MORE SO THAN SOME MODEL PROGS INDICATE. ETA/SPECTRAL FCSTS OF SFC DEW POINTS APCHG 70 DEG F ACROSS NWRN MO BY 14/00Z AND ASSOCIATED LARGE CAPE/LI FCSTS APPEAR OVERBLOWN AS WELL...CONSIDERING 1. IMPROBABILITY OF SUCH ROBUST EVAPOTRANSPIRATIVE MOISTENING IN THAT AREA DURING MID-APRIL AND 2. DRY CHARACTER OF AIR MASS IN UPSTREAM BOUNDARY LAYER...PER WELL-MIXED OUN/FWD SOUNDINGS. WHEN COMPARED TO SFC HAND ANALYSIS...13/00Z ETA INITIALIZED 3-6 DEG F TOO HIGH ON SFC DEW POINTS IN UPSTREAM BOUNDARY LAYER...S OF WARM FRONT OVER PORTIONS OK/AR. SPECTRAL BEGAN UP TO 10 DEG F TOO WARM ON SFC DEW POINT IN SAME AREA. IF SFC-BASED CONVECTION DEVELOPS NEAR SFC LOW AND WARM FRONT...BACKED FLOW E OF LOW AND 50-60 KT MIDLEVEL WINDS WOULD CONTRIBUTE TO FAVORABLE KINEMATIC PROFILES...WITH 0-3 KM SRH 200-300 J/KG AND 60-70 KT SFC-MIDLEVEL SHEARS. HOWEVER...SUCH DEVELOPMENT WOULD BE VERY ISOLATED...AND MAY NOT EVEN OCCUR. POTENTIAL FOR BRIEF WINDOW OF LATE AFTERNOON TSTMS MAY BE SOMEWHAT LARGER ALONG TRAILING COLD FRONT OVER IA/SERN NEB...WHERE HEATING/MIXING WILL BE STRONGER. DAMAGING GUSTS AND HAIL ARE POSSIBLE FROM ANY TSTMS THAT FORM...BUT CAPPING WILL LIMIT COVERAGE. STRONG LOW LEVEL MOIST ADVECTION AND ELEVATED WAA ARE EXPECTED AFTER DARK...NE OF SFC WARM FRONT. POTENTIAL IS EXPECTED TO SHIFT ESEWD FROM SRN MN ACROSS NRN INDIANA/SRN LOWER MI OVERNIGHT. EXPECT INCREASING CONVECTIVE COVERAGE IN TUNE WITH INCREASING INFLOW-LAYER MOISTURE CONTENT AND LLJ INCREASING TO 50-60 KT DURING 14/06Z-14/12Z TIME FRAME. 8-9 DEG C/KM MIDLEVEL LAPSE RATES SHOULD SPREAD NEWD OVER AREA AS ELEVATED MIXED-LAYER AIR ADVECTS FROM SRN/CENTRAL PLAINS...CONTRIBUTING TO ELEVATED MUCAPES 1500-2000 J/KG. IN ADDITION...FAVORABLE EFFECTIVE SHEAR PROFILES -- ABOVE RELATIVELY STABLE BOUNDARY LAYER -- WILL SUPPORT ORGANIZED SEVERE RISK WITH LARGE HAIL THE MOST COMMON SEVERE MODE...AND DAMAGING WIND POSSIBLE DESPITE SHALLOW/COOL BOUNDARY LAYER. ...WRN NY...NRN PA... WIDELY SCATTERED TSTMS ARE POSSIBLE DURING AFTERNOON...AMIDST RESIDUAL/POST-FRONTAL SFC MOISTURE AND BOUNDARY LAYER HEATING/MIXING. COLD AIR ALOFT IS EXPECTED INVOF MID/UPPER TROUGH -- E.G. -23 TO -26 DEG C AT 500 MB -- ALONG WITH VERY WEAK SBCINH BY MID-LATE AFTERNOON. BOUNDARY LAYER FLOW IS EXPECTED TO BE WLY...RESTRICTING BOTH VERTICAL SHEAR AND SFC CONVERGENCE...AND BY EXTENSION...LIMITING CONVECTIVE COVERAGE. HOWEVER...CONSIDERING COLD AIR MASS THROUGH MIDTROPOSPHERE...ISOLATED HAIL NEAR SEVERE LEVELS IS POSSIBLE. ..EDWARDS.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 12:55:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 08:55:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131251 SWODY1 SPC AC 131250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT THU APR 13 2006 VALID 131300Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID AND UPPER MS VALLEY... BROAD UPPER RIDGE REMAINS IN PLACE ACROSS THE SOUTHERN PLAINS TODAY...WITH BAND OF MODERATELY STRONG MID/UPPER LEVEL FLOW FROM THE NORTHERN ROCKIES INTO THE GREAT LAKES REGION. SEVERAL WEAK SHORTWAVE TROUGHS ARE EMBEDDED IN THIS FLOW PATTERN. ONE FEATURE EVIDENT IN WATER VAPOR IMAGERY OVER MT IS FORECAST TO TRACK EASTWARD INTO MN BY THIS EVENING. SURFACE LOW IS FORECAST TO DEVELOP OVER SOUTHERN MN BY 14/00Z...WITH WARM FRONT EXTENDING EASTWARD INTO NORTHERN IL/IND. EVOLUTION OF BOUNDARY LAYER SOUTH OF LOW/FRONT WILL BE QUITE COMPLEX...BUT APPEARS FAVORABLE FOR RAPID MOISTENING/DESTABILIZATION THROUGH THE AFTERNOON. MODEL FORECAST DEWPOINT VALUES MAY BE SLIGHTLY OVERDONE...BUT MID 60S VALUES APPEAR REASONABLE. IT APPEARS THAT SUBSIDENCE IN THE CAPPING LAYER...COMBINED WITH INFLUX OF LOW LEVEL MOISTURE FROM THE SOUTHWEST...WILL RESULT IN LOCAL POOLING OF SURFACE DEWPOINTS IN THE MID 60S ACROSS PARTS OF MO/IA. ...MN/WI/IL... PRESENT INDICATIONS ARE THAT ISOLATED STORMS WILL DEVELOP BY LATE AFTERNOON/EARLY EVENING OVER SOUTHEAST MN/SOUTHWEST WI ALONG WARM FRONT. THESE STORMS WILL BE IN A FAVORABLE VERTICAL SHEAR ENVIRONMENT FOR SUPERCELL STRUCTURES CAPABLE OF LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES. THIS ACTIVITY WILL SPREAD EASTWARD INTO PARTS OF NORTHERN IL/IND OVERNIGHT. ...IA/MO/IL/IND/KY/OH... OTHER STORMS ARE POSSIBLE OVER EASTERN IA ALONG TRAILING DRYLINE...WHERE WEAK CAP AND STRONG HEATING WILL OCCUR. THIS ACTIVITY WILL LIKELY SPREAD SOUTHEASTWARD ACROSS NORTHEAST MO/CENTRAL IL DURING THE EVENING WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY DEVELOP UPSCALE INTO AN MCS...SPREADING ACROSS PARTS OF IND AND INTO OH/KY BY 14/12Z. ...NY INTO MID ATLANTIC REGION... MORNING VISIBLE SATELLITE IMAGERY SUGGEST THAT STRONG DAYTIME HEATING WILL OCCUR TODAY FROM CENTRAL/EASTERN NY INTO VA AND NORTHERN NC. THIS REGION IS BENEATH UPPER COLD TROUGH...WITH 500MB TEMPERATURES RANGING FROM -17C OVER NC TO -25 OVER NY. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THIS REGION DURING THE AFTERNOON. STEEP LAPSE RATES AND SUFFICIENT INSTABILITY SUGGEST A THREAT OF HAIL IN STRONGER CELLS. ACTIVITY SHOULD DIMINISH QUICKLY AFTER SUNSET. ..HART/TAYLOR.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 16:38:23 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 12:38:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131631 SWODY1 SPC AC 131629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CDT THU APR 13 2006 VALID 131630Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF THE MID AND UPPER MS VALLEY... ...SYNOPSIS... BROAD RIDGING ACROSS MUCH OF CONUS WITH FAST WESTERLIES EXTENDING EWD ACROSS NRN US INTO WRN GREAT LAKES. FLOW THEN BECOMES WNWLY INTO TROUGH OFF E COAST. MID LEVEL TROUGH ERN GREAT LAKES WILL MOVE ESEWD TO BE OFFSHORE BY THIS EVENING. UPSTREAM...S/WV TROUGH AND MIDLEVEL WIND MAX CURRENTLY NRN PLAINS/CANADIAN BORDER REGION MOVES ACROSS FLAT RIDGE TO WRN GREAT LAKES TONIGHT. CURRENTLY ACTIVE PRESSURE FALLS UPPER MS VALLEY WILL LEAD TO SURFACE LOW DEVELOPMENT ACROSS SRN MN THIS AFTERNOON. WARM FRONTAL ZONE WILL EXTEND FROM SURFACE LOW ESEWD ACROSS WI INTO SRN LWR MI BY THIS EVENING WITH A DRY LINE FROM THE LOW SSWWD THRU ERN NEB INTO CENTRAL KS. SLY LOW LEVEL FLOW IS SPREADING MOISTURE AND INSTABILITY NWD THRU ERN PLAINS AND LOWER MO VALLEY IN ADVANCE OF THIS SYSTEM WITH AIR MASS BECOMING VERY UNSTABLE BY MID AFTERNOON. ...SRN MN/IA ACROSS SRN WI/NRN IL INTO WRN OH... LOW LEVEL MOISTURE SPREADING NEWD THRU ERN PLAINS AND LOWER MO VALLEY COUPLED WITH STEEP LAPSE RATES IN PLACE AND NEARLY FULL HEATING WILL RESULT IN MLCAPES IN EXCESS OF 3000 J/KG DEVELOPING IN WARM SECTOR THIS AFTERNOON. OBSERVED MOISTURE ADVECTION SUPPORTS LOW 60 DEWPOINTS INTO IA THIS AFTERNOON...NOT QUITE AS HIGH AS THE NAM...HOWEVER SUFFICIENT TO DEVELOP THE VERY UNSTABLE AIR MASS. CAP WILL HOLD MUCH OF AFTERNOON IN THE WARM SECTOR...HOWEVER WARM FRONTAL LIFT COULD INITIATE STORMS ACROSS SRN MN INTO WI. STRONG VEERING SHEAR PROFILES AND AVAILABLE THERMODYNAMICS SUPPORT SUPERCELL POTENTIAL...AND WITH SURFACE BASED STORMS...TORNADOES WILL BE POSSIBLE. IN ADDITION VERY LARGE HAIL IS QUITE LIKELY PER SPC HAIL MODEL OUTPUT. DRY LINE WILL ALSO BECOME AN INCREASING CONCERN FOR INITIATION BY EVENING IA SWD INTO NRN MO. AGAIN VERY LARGE HAIL WOULD BE THE PRIMARY THREAT WHILE STORM MODE REMAIN MORE CELLULAR. OVERNIGHT THE CONTINUED AVAILABILITY OF MDT TO VERY UNSTABLE AIR ALONG WITH THE INCREASE AND VEERING LOW LEVEL JET SHOULD FUEL THE DEVELOPMENT OF ONE OR MORE SEVERE MCS'S. INCREASING THREAT OF DAMAGING WINDS ALONG WITH THE LARGE HAIL POTENTIAL WILL SPREAD EWD OVERNIGHT INTO THE OH VALLEY AS THE UPPER WIND MAX/S/WV TROUGH MOVES EWD INTO WRN LAKES. ...NY SWD TO VA... STEEP LAPSE RATES AND STRONG HEATING COUPLED WITH ADEQUATE MOISTURE AND COLD AIR ALOFT WILL SUPPORT SCATTERED THUNDERSTORMS THIS AFTERNOON. LARGE HAIL WOULD BE POSSIBLE WITH THE STRONGEST UPDRAFTS GIVEN THE COLD AIR ALOFT AND STEEP LAPSE RATES. WITH ACTIVITY NOT EXPECTED TO BECOME VERY ORGANIZED AS LOW LEVEL SHEAR GENERALLY WEAK...WILL CONTINUE A LOW SEVERE HAIL AND WIND RISK THRU THE AFTERNOON. ..HALES/JEWELL.. 04/13/2006  From SwoDy1 at goshenarc.org Thu Apr 13 20:03:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 16:03:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131959 SWODY1 SPC AC 131958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0258 PM CDT THU APR 13 2006 VALID 132000Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST...SRN GREAT LAKES AND OH VALLEY... ...UPPER MIDWEST/OH VALLEY... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SUBTLE SHORTWAVE TROUGH EMBEDDED IN WNW FLOW OVER SRN MN EXTENDING SWWD ACROSS FAR SE SD. THIS FEATURE IS FORECAST TO MOVE QUICKLY ESEWD ACROSS THE REGION LATE THIS AFTERNOON INTO THIS EVENING. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE AND A WEAKENING CAPPING INVERSION WILL PROVIDE SUPPORT FOR CONVECTIVE INITIATION LATE THIS AFTERNOON ACROSS WRN WI AND ERN IA. STORMS SHOULD GRADUALLY EXPAND IN COVERAGE WITH AN MCS DEVELOPING AND MOVING QUICKLY ESEWD ACROSS THE REGION THIS EVENING AND OVERNIGHT. LATEST SFC ANALYSIS CURRENTLY SHOWS A MOIST AXIS WITH SFC DEWPOINTS IN THE 60S F EXTENDING NWD ACROSS MO INTO SRN IA. SLY FLOW WILL CONTINUE MOIST ADVECTION INTO IA AND IL THIS AFTERNOON WITH A STRONG LOW-LEVEL MOISTURE GRADIENT SETTING UP FROM NEAR THE DES MOINES/CEDAR RAPIDS AREA EXTENDING ESEWD TO NEAR SPRINGFIELD IL. ALONG AND SOUTH OF THIS GRADIENT...MODERATE INSTABILITY SHOULD BE IN PLACE WITH MLCAPE VALUES IN THE 2000 TO 3000 J/KG RANGE BY LATE THIS AFTERNOON AND EARLY THIS EVENING. IN ADDITION...WNWLY FLOW ALOFT IS CREATING STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH VERY STEEP LAPSE RATES AND THE MODERATE INSTABILITY SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE STRONGER SUPERCELLS MAY ALSO BE CAPABLE OF PRODUCING VERY LARGE HAIL ESPECIALLY ACROSS CNTRL/ERN IA AND NW IL LATE THIS AFTERNOON WHEN INSTABILITY SHOULD BE MAXIMIZED. IN ADDITION...MODELS FORECAST A 50 KT LOW-LEVEL JET TO EXPAND NWD ACROSS THE REGION WHICH WILL CREATE STRONG LOW-LEVEL SHEAR PROFILES WHICH COMBINED WITH THE MOISTURE ADVECTION SHOULD RESULT IN A TORNADO/WIND DAMAGE THREAT AS SUPERCELLS MOVE ESEWD ACROSS ERN IA INTO NRN AND CNTRL IL AND WRN IND THIS EVENING. IF A LARGE-SCALE BOW ECHO DEVELOPS AS THE NAM CONVECTIVE QPF FIELDS SUGGEST...THEN THE WIND DAMAGE POTENTIAL WOULD LIKELY BE ENHANCED CONTINUING OVERNIGHT AS THE LINEAR MCS TRACKS ESEWD ACROSS IND...NRN KY INTO OH. ..BROYLES.. 04/13/2006  From SwoDy1 at goshenarc.org Fri Apr 14 01:05:49 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 13 Apr 2006 21:05:49 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140102 SWODY1 SPC AC 140100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT THU APR 13 2006 VALID 140100Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS VALLEY TO WRN WV... ...SYNOPSIS... SYNOPTIC UPPER AIR PATTERN SHOULD REMAIN DOMINATED BY NEARLY ZONAL FLOW ACROSS NRN CONUS...RIDGING AND HIGH HEIGHTS FROM 4-CORNERS REGION TO FL...AND NEARLY CUT-OFF MID/UPPER LEVEL LOW OFFSHORE SRN CA. MOISTURE CHANNEL IMAGERY INDICATES SHORTWAVE TROUGH OVER SERN SK...SWRN MB AND NRN ND. SUBTLE PERTURBATION IS EVIDENT IN MOISTURE CHANNEL IMAGERY AND VWP/PROFILER TIME SERIES OVER CENTRAL IA...A FEATURE WHICH TRACKS BACK TO AT LEAST 13/12Z OVER NERN CO. THIS FEATURE -- NOT DEPICTED IN SPECTRAL BUT EVIDENT IN LATEST RUC/ETA -- SHOULD PHASE WITH NRN STREAM TROUGH TO FORM POSITIVELY TILTED SHORTWAVE THAT WILL MOVE ESEWD ACROSS NRN ONT AND UPPER GREAT LAKES REGION OVERNIGHT. SFC ANALYSIS SHOWS DIFFUSE COLD FRONT MOVING EWD ACROSS MN AND SEWD ACROSS CENTRAL MEB...WITH STRONGER CAA REINFORCEMENT OVER CENTRAL ND AND WRN SD. WAVY DRYLINE MEANDERS FROM S-CENTRAL KS NWD TO SERN NEB...THEN ENEWD ACROSS NRN IA...INTERSECTING WARM FRONT OVER SERN MN. DIFFUSE WARM FRONT SHOULD LIFT NWD ACROSS REMAINDER SERN MN AND MUCH OF WI OVERNIGHT. WEAK SFC CYCLOGENESIS IS POSSIBLE OVERNIGHT ALONG WARM FRONT...ACROSS PORTIONS WI/LM. ERN PORTION WARM FRONT SHOULD MOVE SLOWLY NWD OVER NRN INDIANA...SRN LM AND PERHAPS SWRN LOWER MI. ...IA/MN TO UPPER OH VALLEY... REF WW 178 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR NEAR-TERM INFO ON UPPER MS VALLEY SEVERE POTENTIAL. WEAK IA SHORTWAVE TROUGH CORRESPONDED WELL TO FIELD OF CUMULIFORM CLOUDS THAT EVOLVED INTO CURRENT CENTRAL IA TSTM COMPLEX...ONCE ASSOCIATED FIELD OF LARGE SCALE ASCENT MOVED ATOP STRONGEST BOUNDARY LAYER HEATING AND WEAKEST CINH. THIS FEATURE WILL HELP TO MAINTAIN FAVORABLE LARGE SCALE ENVIRONMENT FOR SEVERE -- BOTH IN TERMS OF DEEP-LAYER SHEAR AND STEEPENED MIDLEVEL LAPSE RATES -- AS IT MOVES ACROSS IL/INDIANA OVERNIGHT. FIELDS OF HIGH-BASED/MIDLEVEL CONVECTION IS EVIDENT IN VIS IMAGERY OVER ERN DAKOTAS AND NWRN WI E OF MSP...EACH OF WHICH HAS PRODUCED A FEW LIGHTNING STRIKES. DAKOTAS ACTIVITY IS ASSOCIATED WITH STRONGEST LARGE SCALE ASCENT AHEAD OF NRN STREAM TROUGH...AND MAY INTENSIFY AS IT MOVES EWD PAST SFC FRONTAL ZONE INTO MN...WITH ACCESS TO SOMEWHAT MORE ROBUST MOISTURE FIELD ABOVE SFC. WRN WI ACTIVITY MAY INCREASE AS BOUNDARY LAYER DECOUPLES AND LLJ STRENGTHENS IN INFLOW SECTOR. ANY OF THESE AREAS OF CONVECTION MAY EVOLVE INTO MCS OVERNIGHT...MOVING SEWD ACROSS GREAT LAKES TOWARD LOWER MI...AND OH/WV REGION. MOST PROBABLE AREA FOR LONG-LIVED MCS EVOLUTION IS OVER ERN IA AND NRN IL...EVOLVING FROM ONGOING MIX OF MULTICELLS AND SUPERCELLS OVER IA. ASSOCIATED POTENTIAL FOR DAMAGING GUSTS AND LARGE HAIL SHOULD EXTEND ESEWD ACROSS INDIANA/OH/WV/WRN PA AS THIS ACTIVITY MOVES THROUGH WRN PORTION OF INCREASINGLY MOIST...45-60 KT LLJ. ..EDWARDS.. 04/14/2006  From SwoDy1 at goshenarc.org Sat Apr 15 01:10:29 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 14 Apr 2006 21:10:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150107 SWODY1 SPC AC 150106 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0806 PM CDT FRI APR 14 2006 VALID 150100Z - 151200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS INDIANA...SWRN OH...N-CENTRAL/NERN KY... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM CENTRAL IL TO WRN VA... ...SYNOPSIS... PROGRESSIVE UPPER AIR PATTERN FEATURES STRONG SHORTWAVE TROUGH THAT WILL MOVE NEWD FROM SRN CA ACROSS 4-CORNERS REGION THROUGH REMANDER PERIOD. SFC ANALYSIS SHOWS WEAK COLD FRONT FROM SWRN LM SWWD ACROSS NWRN MO...S-CENTRAL KS...BECOMING QUASISTATIONARY WSWWD ACROSS NWRN OK INTO WEAK LOW OVER CENTRAL PORTION OK PANHANDLE. OUTFLOW BOUNDARY FROM EARLIER CONVECTIVE COMPLEXES IS EVIDENT FROM NERN IL SEWD NEAR A LINE FROM 35 NE CMI...IND...20 W CVG...45 NNE JKL...CRW. OVERALL THIS BOUNDARY SHOULD MOVE LITTLE THROUGH REMAINDER PERIOD...BUT WILL BE SHUNTED SWD LOCALLY BY INDIVIDUAL TSTM OUTFLOWS. ...IL TO CENTRAL APPALACHIANS... SEVERAL POTENTIALLY TORNADIC SUPERCELLS ARE EXPECTED TO CONTINUE MOVING ESEWD ACROSS THIS CORRIDOR...IN ENVIRONMENT OF FAVORABLE MESOSCALE ENHANCEMENT TO BOTH SHEAR AND BUOYANCY. ANOTHER CLUSTER OF MOSTLY HAIL PRODUCING TSTMS OVER NRN WV AND SWRN PA SHOULD CONTINUE MOVING SEWD TOWARD NRN/WRN VA...SEVERE POTENTIAL GRADUALLY DIMINISHING AS IT ENCOUNTERS PROGRESSIVELY MORE DRY/STABLE INFLOW LAYER. REF WWS 184-188 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST DETAILS OVER THIS REGION. OVERALL...MOST FAVORABLE ZONE FOR SEVERE WILL REMAIN ALONG AND JUST N OF OUTFLOW BOUNDARY BETWEEN CENTRAL/NERN IL AND SWRN OH/NERN KY. MODIFIED SOUNDINGS AND RUC SOUNDINGS INDICATE LIFTED PARCELS WILL REMAIN SFC-BASED OR NEARLY SO INVOF BOUNDARY...WHICH ALSO IS ORIENTED FAVORABLY FOR RIGHTWARD MOTION OFF HODOGRAPH. EXPECT EVAPOTRANSPIRATIVELY BOOSTED SFC DEW POINTS -- LOW-MID 60S F RESULTING FROM EARLIER RAINFALL...AND LOWER LCL ALONG AND N OF BOUNDARY. LCL ALSO SHOULD DROP ALONG AND JUST S OF BOUNDARY IN RELATION TO SFC DIABATIC COOLING THROUGH EVENING HOURS...WHILE THOSE PARCELS REMAIN NEARLY SFC-BASED AS WELL. GREATEST THREAT SHOULD REMAIN E OF WEAK MESOLOW -- ANALYZED ON SFC CHARTS OVER EXTREME E-CENTRAL IL AND NWRN INDIANA ALONG OUTFLOW BOUNDARY. PRECEDING SFC PRESSURE FALLS AND RELATIVELY BACKED FLOW N OF BOUNDARY WILL KEEP 0-1 AND 0-3 KM AGL HODOGRAPHS FAVORABLY ENLARGED...WITH SRH AS HIGH AS 400-600 J/KG THROUGH THOSE LAYERS. 60-70 KT DEEP-LAYER SHEARS ALSO SILL CONTINUE TO SUPPORT SUPERCELL S...AS WELL AS POTENTIAL FOR EVENTUAL BOW ECHO DEVELOPMENT. SOMETIME AROUND 15/06Z...EXPECT PROGRESSIVELY MORE DECOUPLED BOUNDARY LAYER...SOMEWHAT ELEVATED PRIMARY INFLOW LAYER AND RELATED INCREASE IN LLJ TO SUPPORT ONE OR MORE MCS BETWEEN INDIANA AND SRN WV. DAMAGING GUSTS AND OCCASIONAL HAIL WILL BE POSSIBLE DURING SUBSEQUENT LATE NIGHT/EARLY MORNING HOURS. ..EDWARDS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 06:02:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 02:02:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150559 SWODY1 SPC AC 150557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT SAT APR 15 2006 VALID 151200Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS CENTRAL/ERN NEB...PORTIONS WRN/SRN IA...N-CENTRAL/NWRN MO...PORTIONS N-CENTRAL/NERN KS.... ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM WRN NEB AND ERN KS TO CENTRAL INDIANA.... ...THERE IS A SLGT RISK OF SVR TSTMS SERN OH...CENTRAL APPALACHIANS TO COASTAL MD/VA/NERN NC.... ...SYNOPSIS... IN MID/UPPER LEVELS...EXPECT PROGRESSIVE SHORTWAVE TRAIN WITHIN LARGER SCALE PATTERN THAT FEATURES CENTRAL CONUS RIDGE...AND TROUGHS OVER NERN PACIFIC AND QUE/NEW ENGLAND REGIONS. MOST CRITICAL DAY-1 SYSTEM WILL BE STRONG TROUGH AND EMBEDDED MIDLEVEL CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER LOWER CO RIVER VALLEY. THIS FEATURE WILL CONTINUE TO MOVE NEWD FROM S-CENTRAL ROCKIES ACROSS CENTRAL PLAINS...DECELERATING LATE IN PERIOD OVER ERN NEB/SRN IA/NERN MO REGION AS IT PENETRATES LARGE SCALE RIDGE POSITION. MEANWHILE...WEAK/LOW-AMPLITUDE SHORTWAVE PERTURBATION NOW INVOF MEAN RIDGE -- OVER SERN SASK/SRN MB -- SHOULD MOVE SEWD ACROSS GREAT LAKES TOWARD DELMARVA REGION BY 16/00-16/06Z TIME FRAME. STRONG SHORTWAVE TROUGH NOW OVER NERN/ERN ONT SHOULD DIG ESEWD ACROSS QUE AND NRN NEW ENGLAND THROUGH PERIOD. AT SFC...QUASISTATIONARY FRONTAL ZONE IS ANALYZED FROM CENTRAL/WRN PORTIONS KS/OK BORDER NEWD ACROSS CENTRAL IL...THEN SEWD OVER CENTRAL VA. PORTION FROM IL-WV IS CONVECTIVELY REINFORCED...DISPLACED SW OF MORE DIFFUSE SYNOPTIC WARM FRONTAL POSITION OVER LOWER GREAT LAKES REGION. THIS BOUNDARY SHOULD REMAIN NEARLY STATIONARY FROM IL THROUGH CENTRAL APPALACHIANS DURING MOST OF PERIOD...WHILE MOVING SWD ACROSS VA. WRN PORTION SHOULD RETREAT NWD AS WARM FRONT ACROSS CENTRAL PLAINS AND MID MS VALLEY...AHEAD OF VIGOROUS CENTRAL PLAINS CYCLOGENESIS. THIS LOW -- NOW WEAKLY EVIDENT OVER SERN CO -- SHOULD DEEPEN CONSIDERABLY AS IT MOVES NEWD TO N-CENTRAL/NERN NEB BY 16/00Z. DURING DAY...BLENDED DRYLINE AND PACIFIC FRONT WILL MOVE EWD ACROSS PORTIONS SRN NEB...WRN/CENTRAL KS AND WRN/CENTRAL OK S OF SFC LOW. ...CENTRAL PLAINS... POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT -- RELATIVELY CONFINED GEOGRAPHICALLY BUT WITH THREAT OF SEVERAL VERY DAMAGING SUPERCELLS -- IS POSSIBLE IN AND NEAR MDT RISK AREA. TORNADOES AND DAMAGING HAIL/GUSTS ARE EXPECTED. PRIMARY CONCERN WILL BE FROM MID-AFTERNOON THROUGH EVENING...THOUGH EARLIEST SFC-BASED SEVERE TSTMS MAY INITIATE DURING EARLY AFTERNOON OVER CENTRAL HIGH PLAINS...JUST AHEAD OF EJECTING SFC CYCLONE. DESTABILIZATION ALOFT SHOULD BE VIGOROUS WITH THIS SYSTEM AS IT APCHS...GIVEN -22 DEG C 50 MB TEMPS OBSERVED IN 15/00Z NKX RAOB...100-120 M/12 HOUR HEIGHT FALLS OBSERVED IN MIDLEVELS FROM THERE NEWD ACROSS NRN AZ...CONSIDERABLE AMOUNT OF THUNDER DETECTED IN PAST FEW HOURS ACROSS SRN NV/UT...AND INTENSE DPVA FCST TO SHIFT ENEWD ACROSS KS/NEB BY 16/00Z. ANY SUPERCELLS DEVELOPING ALONG/AHEAD OF DRYLINE DURING AFTERNOON SHOULD MOVE NEWD OVER KS AND NNEWD TO NNWWD OVER NEB. TORNADO POTENTIAL SHOULD BE GREATEST INVOF WARM FRONT WHERE INDIVIDUAL TSTMS THAT DEVELOPED FARTHER SW HAVE HAD TIME TO MATURE...AND TO ENCOUNTER AREA OF ENHANCED VORTICITY/SRH AND LOWERED LCL CHARACTERIZING BAROCLINIC ZONE. CONVECTIVE COVERAGE SHOULD DIMINISH WITH SWD EXTENT ACROSS KS/OK BECAUSE OF DIMINISHING LOW AND MIDDLE LEVEL FORCING...STRENGTHENING CINH...AND WEAKER MLCAPE RELATED TO MORE VIGOROUS MIXING/DRYING OF MOIST SECTOR BOUNDARY LAYER. LARGE/DAMAGING HAIL...SEVERE GUSTS AND PERHAPS A FEW TORNADOES ARE POSSIBLE FROM ANY TSTMS THAT DO FORM FROM CENTRAL/ERN KS SWD ALONG DRYLINE. HOWEVER...SEVERE POTENTIAL BECOMES MORE STRONGLY CONDITIONAL WITH SWD EXTENT UNTIL THUNDER POTENTIAL GETS TOO LOW TO JUSTIFY SEVERE PROBABILITIES. ...MID MS VALLEY -- ERN MO/IL/INDIANA... ADDITIONAL SEVERE TSTMS MAY DEVELOP DURING AFTERNOON/EVENING FARTHER SE ACROSS WARM FRONT AND ADJACENT MOIST SECTOR...OVER PORTIONS MO/IL. VERTICAL SHEAR PROFILES...WHILE NOT AS INTENSE AS IN ZONE OF STRONG ISALLOBARIC FORCING NEAR SFC LOW -- STILL MAY SUPPORT SEVERE MULTICELLS...AND PERHAPS A FEW HEAVY-PRECIP SUPERCELL/BOW MORPHOLOGIES. MOST FAVORABLE KINEMATIC AND THERMODYNAMIC PROFILES WILL BE INVOF SFC WARM FRONT WHERE BACKED SFC WINDS ENHANCE DEEP-LAYER SHEARS...THOUGH WEAK LOW LEVEL WINDS MAY KEEP BOUNDARY LAYER HODOGRAPHS RELATIVELY SMALL. LITTLE OR NO MID/UPPER LEVEL FORCING IS LIKELY FOR MUCH OF PERIOD...THOUGH CONVECTION MAY BE AIDED BY LOW LEVEL WAA...FRONTAL LIFT AND WEAK CINH RESULTING FROM AFTERNOON INSOLATION. ALTHOUGH MODEL FCST DEW POINTS APPEAR OVERDONE ONCE AGAIN...WELL HEATED/MIXED BOUNDARY LAYERS AND UPPER 50S/LOW 60S DEW POINTS MAY SUPPORT 2000-2500 J/KG MLCAPES FROM 15/21Z-16/00Z. SUPERCELL POTENTIAL MAY INCREASE AFTER DARK OVER CENTRAL/ERN MO AS STRONGER WINDS ALOFT OVERSPREAD AREA AHEAD OF MIDLEVEL LOW. ... CENTRAL APPALACHIANS TO TIDEWATER REGION... CONTINUED POTENTIAL EXISTS THROUGH MUCH OF PERIOD FOR CLUSTERS OF STRONG-SEVERE TSTMS TO FORM INVOF PERSISTENT BAROCLINIC ZONE. MOST PROBABLE SEVERE TSTM THREAT WILL BE FROM AFTERNOON THROUGH EVENING FROM WV THROUGH WRN/CENTRAL VA...SHIFTING ESEWD ACROSS PORTIONS ERN/SRN VA AND NRN NC. STEEP MIDLEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPES POTENTIALLY EXCEEDING 2000 J/KG IN SOME PARTS OF THIS REGION. INVERTED-V THERMODYNAMIC PROFILES IN FCST SOUNDINGS RESULT FROM STRONG HEATING/MIXING OF BOUNDARY LAYER ALONG AND S OF FRONTAL ZONE...CONTRIBUTING TO POTENTIAL FOR BOTH HAIL AND DAMAGING GUSTS TO REACH SFC. ...NERN CONUS... POCKETS OF FAVORABLE SFC HEATING WITH WEAK CINH MAY CONTRIBUTE TO CONVECTIVE POTENTIAL FROM LATE MORNING THROUGH AFTERNOON...WITH SOME HAIL/GUSTS NEAR SEVERE LEVELS POSSIBLE. SFC DEW POINTS MID 50S...ISOLATED NEAR 60 F...ARE POSSIBLE FROM ERN PA ACROSS PORTIONS NJ/SERN NY W OF WARM FRONT THAT WILL BE MOVING EWD OVER THIS REGION. NEARLY UNIDIRECTIONAL WLY-WNWLY WIND PROFILES ARE FCST THROUGH MOST OF TROPOSPHERE. THIS SHOULD LIMIT CONVERGENCE AND OVERALL COVERAGE OF TSTMS...AS WELL AS STRENGTH OF DEEP-LAYER SHEAR. HOWEVER...MID/UPPER FLOW WILL BE ENHANCED S OF ONT/QUE TROUGH...AIDING ORGANIZATION OF ANY SUSTAINED TSTMS THAT DO DEVELOP. ..EDWARDS/GRAMS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 13:11:04 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 09:11:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151307 SWODY1 SPC AC 151305 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0805 AM CDT SAT APR 15 2006 VALID 151300Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE MID/LWR MO VLYS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEB/NRN KS TO THE MID MS VLY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM OH TO THE MID ATLANTIC CST... ...SYNOPSIS... STRONG UPR IMPULSE NOW OVER CO/NRN NM SHOULD CONTINUE RAPIDLY NE INTO CNTRL NEB BY THIS EVENING...BEFORE DECELERATING AS IT CLOSES OFF OVER IA EARLY SUNDAY. ASSOCIATED LEE LOW NOW OVER NE CO EXPECTED TO TRACK TO NEAR KOFU BY EARLY TONIGHT AS TRAILING PACIFIC COLD FRONT SWEEPS INTO FAR ERN KS. DEEPENING OF NEB LOW SHOULD DRAW BOUNDARY NOW EXTENDING FROM NRN KS INTO CNTRL MO/SRN IL NWD AS A WARM FRONT. AT THE SAME TIME...EXPECT THAT ERN PART OF SAME BOUNDARY WILL DROP S ACROSS THE MID ATLANTIC STATES IN RESPONSE TO GRADUAL INCREASE IN NWLY MID/UPR LEVEL FLOW DOWNSTREAM FROM AMPLIFYING SYSTEM IN THE PLAINS. ...MID/LWR MO VLY... CONDITIONS EXPECTED TO BECOME FAVORABLE FOR SEVERE STORMS OVER A SMALL PART OF THE CNTRL PLNS/LWR MO VLY LATE THIS AFTERNOON INTO TONIGHT AS ABRUPT INCREASE IN ASCENT ASSOCIATED WITH APPROACHING UPR TROUGH OVERSPREADS REGION. COMBINATION OF SURFACE HEATING AND CONVERGENCE ALONG AND AHEAD OF COLD FRONT SHOULD OVERCOME CIN AND SUPPORT STORM DEVELOPMENT BY MIDDAY...MOST LIKELY OVER WRN/CNTRL NEB. DEVELOPMENT SHOULD THEN SPREAD S INTO NRN/NE KS WITH TIME AS HEATING FURTHER DESTABILIZES LWR LAYERS...AND FORCING FOR ASCENT ENCOUNTERS MORE SUBSTANTIAL LOW LEVEL MOISTURE INFLOW. COMPACT NATURE OF EJECTING TROUGH AND ASSOCIATED LATITUDINAL VARIATION OF WIND FIELD WILL RESULT IN A HIGHLY VARIABLE DEEP SHEAR PATTERN WITH SPACE/TIME ACROSS THE CNTRL PLNS/LWR MO VLY. SUFFICE IT TO SAY THAT SHEAR WILL NEVERTHELESS BE SUFFICIENT FOR ORGANIZED STORMS/SUPERCELLS THROUGH THE REGION DURING PERIOD OF EXPECTED CONVECTIVE DEVELOPMENT. BUT TEMPORAL VARIATION OF WIND PROFILES... AND THE RELATIVELY LIMITED MOISTURE SUPPLY AT THE OUTSET...DO SERIOUSLY COMPLICATE FORECAST OF DOMINATE CONVECTIVE MODE. WITH INITIAL LOW TO MID LEVEL ENVIRONMENT EXPECTED TO REMAIN LARGELY UNSATURATED OVER MUCH OF ERN NEB...AND PROSPECTS FOR SUBSTANTIAL LOW LEVEL MOISTENING BETWEEN NOW AND CONVECTIVE INITIATION TIME LOOKING SLIM...EXPECT THAT MAIN SEVERE THREATS WILL BE HIGH WIND AND HAIL FROM ROTATING STORMS ORGANIZED IN SHORT BANDS/CLUSTERS. FARTHER S AND E...POTENTIAL FOR LONG-LIVED/MORE DISCRETE SUPERCELLS APPEARS SOMEWHAT GREATER INVOF WARM FRONT IN EXTREME ERN NEB/WRN IA AND NRN MO. ENHANCED LOW LEVEL SRH COULD YIELD A TORNADO THREAT IN ADDITION TO LARGE HAIL/HIGH WIND. ...MID MS VLY... FARTHER E...OTHER SEVERE TSTMS MAY DEVELOP DURING AFTERNOON/EVENING INVOF WARM FRONT OVER PARTS OF THE MID MS VLY. VERTICAL SHEAR...WHILE NOT AS INTENSE AS NEAR UPR TROUGH...MAY -- STILL SUPPORT SEVERE MULTICELLS AND PERHAPS MARGINAL SUPERCELLS. WEAK LOW LEVEL WINDS SHOULD KEEP SRH RELATIVELY SMALL AND MID/UPR LEVEL FORCING LIKELY WILL REMAIN WEAK. BUT HEATING COULD BOOST MLCAPE TO 2000-2500 J/KG. SUPERCELL POTENTIAL MAY INCREASE AFTER DARK OVER ERN MO/IL AS STRONGER FLOW ALOFT OVERSPREADS AREA AHEAD OF UPR TROUGH. ...OH TO MID ATL CST/TIDEWATER AREA... MODERATE...SLIGHTLY DIFFLUENT...DEEP WNW TO NWLY FLOW WILL PREVAIL FROM THE UPR OH VLY TO THE MID ATLANTIC COAST THROUGH THE PERIOD. SATELLITE SUGGESTS A WEAK IMPULSE NOW CRESTING THE WV MOUNTAINS... WITH A SIMILAR DISTURBANCE UPSTREAM OVER WRN LWR MI. SURFACE FEATURES ARE DIFFUSE OVER THE REGION...WITH ONE BOUNDARY EXTENDING FROM SW OH TO CNTRL NY...AND ANOTHER OF APPARENT CONVECTIVE ORIGIN EXTENDING FROM SRN OH TO TIDEWATER VIRGINIA. WHILE MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP...THEY ARE SUFFICIENT FOR STORMS...ESPECIALLY GIVEN THAT SURFACE HEATING SHOULD BE FAIRLY STRONG FROM CNTRL/SRN OH ESE TO THE MID ATLANTIC COAST. OVERALL PATTERN SUGGESTS THE LIKELIHOOD FOR THE DEVELOPMENT OF SCATTERED BANDS/SMALL CLUSTERS OF MAINLY DIURNAL STORMS THAT WILL HAVE THE POTENTIAL FOR HAIL AND POSSIBLY LOCALLY DAMAGING WIND. ..CORFIDI/GRAMS.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 16:34:16 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 12:34:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151630 SWODY1 SPC AC 151628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT SAT APR 15 2006 VALID 151630Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER THE MID MO RIVER VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS TO THE TIDEWATER/MID ATLANTIC COAST... ...PLAINS INTO THE MID MS RIVER VALLEY... WV IMAGERY DEPICTS SIGNIFICANT SYSTEM EJECTING QUICKLY NEWD INTO THE CENTRAL HIGH PLAINS THIS MORNING...WITH SUBSTANTIAL DRYING AND 40+ KT WLY SURFACE WINDS OVER SERN CO SOUTH OF ASSOCIATED SURFACE LOW. LOW CENTER NOW NEAR OGALLALA NEB WILL UNDERGO FURTHER DEEPENING AS IT SHIFTS ENEWD INTO CENTRAL NEB THIS AFTERNOON. MORNING OPERATIONAL MODELS VERY CONSISTENT IN LOCATION OF LARGE SCALE FEATURES ASSOCIATED WITH THIS SYSTEM TODAY AND TONIGHT... WITH VERY FAVORABLE DYNAMIC SET-UP BECOMING ESTABLISHED INTO ERN NEB/ERN KS THIS AFTERNOON. HOWEVER...BOUNDARY LAYER MOISTURE REMAINS QUITE MEAGER AND VERY STRONG CAP REMAINS FIRMLY ESTABLISHED UNDER WELL-MIXED ELEVATED AIR MASS OVER THE PLAINS. OPERATIONAL MODELS CONTINUE TO OVER-FORECAST SURFACE DEW POINTS TODAY. OBSERVED DEW POINTS AT 15Z REQUIRE SUBSTANTIAL INCREASES FROM NON-ADVECTIVE PROCESSES TO REACH THE MID 60S FORECAST BY THE NAM/ETA ACROSS MUCH OF MO...AND UPPER 60F EWD ALONG WARM FRONT TO THE LOWER OH RIVER VALLEY. THE RUC APPEARS MORE REASONABLE IN BRINGING 60F-64F DEW POINTS INTO E-CENTRAL/NERN KS WITH MID 50S F DEW POINTS NWD ACROSS MUCH OF ERN NEB. ATTM...APPEARS STRENGTH OF CAP WILL LIMIT DEVELOPMENT INTO WARM SECTOR UNTIL AFTER 21ZZ. HOWEVER...NEAR 50F SURFACE DEW POINTS SHOULD WRAP NWWD NEAR/AROUND LOW CENTER UNDER MID LEVEL COLD POCKET DURING THE AFTERNOON. SHOULD BOUNDARY LAYER MOISTURE SURVIVE MIXING...STORMS WILL LIKELY DEVELOP DURING THE MID/LATE AFTERNOON INTO WRN/CENTRAL NEB WITHIN STRONG AMBIENT VORTICITY WITH ATTENDANT ISOLATED TORNADO/LARGE HAIL THREAT. PW/S ARE FORECAST TO REMAIN QUITE LOW AND SHOULD SUPPORT LP-SUPERCELLS AND HIGH BASED LINEAR STRUCTURES...INCREASING THE THREAT OF DAMAGING WINDS. THIS ACTIVITY MAY THEN CONSOLIDATE ALONG LEADING OUTFLOW/DEEP ASCENT EWD INTO RELATIVELY GREATER MOISTURE NEAR THE MID MO RIVER VALLEY. SUBSTANTIAL LOW LEVEL SHEAR...ENHANCED BY INTENSE PRESSURE FALLS AHEAD OF ADVANCING LOW CENTER SHOULD ALSO MAINTAIN THE THREAT OF A FEW TORNADOES. FARTHER SOUTH ALONG THE DRY LINE DEVELOPMENT WILL BECOME LESS LIKELY INTO CENTRAL/ERN KS. HOWEVER...SUBSTANTIAL SHEAR AND PRESENCE OF LOWER 60F DEW POINTS/MLCAPE AROUND 2000 J/KG WILL REMAIN FAVORABLE FOR LONG-LIVED SUPERCELLS. AFTER DARK...ONE OR MORE MCSS WILL EVOLVE ALONG NOSE OF STRONG SSWLY LLJ AND OVERSPREAD MUCH OF THE MID/NRN MS RIVER VALLEY. ACTIVITY WILL LIKELY BECOME INCREASINGLY ELEVATED E-NE OF MID MO RIVER VALLEY WITH MAIN THREAT OF LARGE HAIL...THOUGH STRONG ASCENT NEAR WARM FRONT MAY SUSTAIN A NEAR SURFACE-BASED SEVERE THREAT WELL THROUGH THE EVENING INTO NRN MO INTO SERN IA/CENTRAL IL. ...MID MS RIVER VALLEY ACROSS THE OH RIVER VALLEY... LARGE SCALE ASCENT WILL REMAIN WEAK/LACKING OVER MUCH OF THIS REGION TODAY. HOWEVER...AIR MASS WILL BECOME MODERATELY UNSTABLE AND REMAIN UNDER MODEST WNWLY FLOW ALOFT. RIDGING WILL BUILD ACROSS THE MID MS RIVER VALLEY THOUGH THE DAY AHEAD OF PLAINS SYSTEM. HOWEVER...CONVERGENCE NEAR WARM FRONT/RESIDUAL OUTFLOW BOUNDARIES SUGGEST ANY THUNDERSTORM CLUSTER WHICH CAN FORM WILL LIKELY BECOME SEVERE. OVERALL THREAT SHOULD DIMINISH THIS EVENING WITH LOSS OF HEATING. ...CENTRAL APPALACHIANS INTO THE MID ATLANTIC/TIDEWATER... STRONG HEATING AND HIGHER THETA-E AIR MASS FROM ERN WV/PA ACROSS THE DELMARVA AND SRN NJ WILL CONTRIBUTE TO INCREASING DESTABILIZATION THIS AFTERNOON. LARGE SCALE DYNAMIC FORCING FOR ASCENT ACROSS THESE AREAS APPEARS TO REMAIN SOMEWHAT AMBIGUOUS/WEAK BASED ON LATEST WATER VAPOR SATELLITE LOOP AND SHORT-TERM GUIDANCE. HOWEVER...COLD FRONT...NOW DEVELOPING SLOWLY SOUTH FROM OH/PA...AND LEE-TROUGHING EAST OF THE APPALACHIAN FOOTHILLS...SHOULD PROVIDE IMPETUS FOR STORM DEVELOPMENT. BAND OF 60KT NWLY MID LEVEL FLOW AND STEEPENING LOW THROUGH MID LEVEL LAPSE RATES WILL PROMOTE STORM ORGANIZATION AND INTENSIFICATION THROUGH LATE AFTERNOON. STRONG DEEP-LAYER...PRIMARILY UNIDIRECTIONAL...SHEAR INDICATES FAST MOVING STORMS WITH SUPERCELL STRUCTURES POSSIBLE. ACTIVITY MAY BECOME CONCENTRATED NEAR/ALONG LEE-TROUGH/COLD FRONT INTERSECTION FROM SERN PA INTO NRN VA...AND PERHAPS NEAR RESIDUAL/WEAK OUTFLOW BOUNDARY FROM TIP OF DELMARVA PENINSULA WNWWD ACROSS THE TIDEWATER. DAMAGING WIND GUSTS AND HAIL ARE EXPECTED WITH THESE STORMS THROUGH EARLY EVENING WITH SEVERE WEATHER POTENTIAL DIMINISHING RAPIDLY HEREAFTER. ..EVANS/CARBIN/GUYER.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 20:12:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 16:12:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152009 SWODY1 SPC AC 152007 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0307 PM CDT SAT APR 15 2006 VALID 152000Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN NEB...SW IA...NW MO AND FAR NE KS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... ...PLAINS/UPPER MIDWEST... WATER VAPOR IMAGERY SHOWS A VIGOROUS NEGATIVELY-TILTED UPPER-LEVEL TROUGH ENTERING THE PLAINS STATES. A DRY SLOT IS ADVANCING QUICKLY EWD ACROSS KS AND SRN NEB ASSOCIATED WITH A 90 KT MID-LEVEL JET NOSING INTO CNTRL NEB. STORMS ARE CURRENTLY INITIATING AHEAD OF THE DRY SLOT IN ERN KS WHERE A CAPPING INVERSION IS WEAKENING. ADDITIONAL STORMS DEVELOPING IN SCNTRL NEB THIS AFTERNOON SHOULD EXPAND ESEWD ACROSS SERN NEB INTO FAR NW MO. AS THE TROUGH SHIFTS NEWD THROUGH EARLY AFTERNOON...A LARGE MCS SHOULD DEVELOP AND MOVE ENEWD ACROSS ERN NEB...SWRN IA AND FAR NWRN MO. FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR LATE THIS AFTERNOON AND EARLY THIS EVENING SHOW INCREASING INSTABILITY AS A MOIST AXIS WITH SFC DEWPOINTS NEAR 60 F SHIFT NEWD ACROSS THE REGION. IN ADDITION...STRONG VERTICAL SHEAR PROFILES EXIST AND MID-LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN AS THE MID-LEVEL JET PUNCHES INTO THE REGION. THE INSTABILITY AND SHEAR WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. AS DESTABILIZATION CONTINUES AND STORM COVERAGE EXPANDS...THE STRONGER SUPERCELLS SHOULD BE CAPABLE OF VERY LARGE HAIL. IN ADDITION...THE LOW-LEVEL SHEAR PROFILES WILL BECOME INCREASINGLY FAVORABLE FOR A FEW TORNADIC SUPERCELLS BY EARLY EVENING AS A 50 TO 60 KT LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE MODERATE RISK AREA. AS STORM COVERAGE EXPANDS AND A MCS MOVES ACROSS SRN IA AND NRN MO INTO FAR NWRN IL THIS EVENING...A FEW TORNADOES ALONG WITH LARGE HAIL AND WIND DAMAGE WILL CONTINUE TO BE POSSIBLE. THE SEVERE THREAT SHOULD EVENTUALLY BECOME MARGINAL AS THE CONVECTIVE COMPLEX MOVES EWD INTO IND AFTER MIDNIGHT WHERE INSTABILITY WILL BE WEAKER. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... WATER VAPOR IMAGERY CURRENTLY SHOWS A SUBTLE SHORTWAVE TROUGH ACROSS THE OH VALLEY MOVING INTO THE CNTRL APPALACHIAN MTNS. SCATTERED THUNDERSTORM DEVELOPMENT SHOULD CONTINUE TO OCCUR AHEAD OF THIS FEATURE IN THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS THIS AFTERNOON. OBJECTIVE ANALYSIS ACROSS THE REGION SHOW STRONG VERTICAL SHEAR PROFILES...MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. STORM COVERAGE ALONG WITH THE SEVERE POTENTIAL SHOULD DECREASE THIS EVENING AS INSTABILITY WEAKENS AND A SHORTWAVE RIDGE APPROACHES FROM THE WEST. ..BROYLES.. 04/15/2006  From SwoDy1 at goshenarc.org Sat Apr 15 20:31:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 16:31:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152022 SWODY1 SPC AC 152020 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0320 PM CDT SAT APR 15 2006 VALID 152000Z - 161200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN NEB...SW IA...NW MO AND FAR NE KS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... CORRECTED TO ADJUST CATEGORICAL AND HAIL LINES ...PLAINS/UPPER MIDWEST... WATER VAPOR IMAGERY SHOWS A VIGOROUS NEGATIVELY-TILTED UPPER-LEVEL TROUGH ENTERING THE PLAINS STATES. A DRY SLOT IS ADVANCING QUICKLY EWD ACROSS KS AND SRN NEB ASSOCIATED WITH A 90 KT MID-LEVEL JET NOSING INTO CNTRL NEB. STORMS ARE CURRENTLY INITIATING AHEAD OF THE DRY SLOT IN ERN KS WHERE A CAPPING INVERSION IS WEAKENING. ADDITIONAL STORMS DEVELOPING IN SCNTRL NEB THIS AFTERNOON SHOULD EXPAND ESEWD ACROSS SERN NEB INTO FAR NW MO. AS THE TROUGH SHIFTS NEWD THROUGH EARLY AFTERNOON...A LARGE MCS SHOULD DEVELOP AND MOVE ENEWD ACROSS ERN NEB...SWRN IA AND FAR NWRN MO. FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR LATE THIS AFTERNOON AND EARLY THIS EVENING SHOW INCREASING INSTABILITY AS A MOIST AXIS WITH SFC DEWPOINTS NEAR 60 F SHIFT NEWD ACROSS THE REGION. IN ADDITION...STRONG VERTICAL SHEAR PROFILES EXIST AND MID-LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN AS THE MID-LEVEL JET PUNCHES INTO THE REGION. THE INSTABILITY AND SHEAR WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. AS DESTABILIZATION CONTINUES AND STORM COVERAGE EXPANDS...THE STRONGER SUPERCELLS SHOULD BE CAPABLE OF VERY LARGE HAIL. IN ADDITION...THE LOW-LEVEL SHEAR PROFILES WILL BECOME INCREASINGLY FAVORABLE FOR A FEW TORNADIC SUPERCELLS BY EARLY EVENING AS A 50 TO 60 KT LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE MODERATE RISK AREA. AS STORM COVERAGE EXPANDS AND A MCS MOVES ACROSS SRN IA AND NRN MO INTO FAR NWRN IL THIS EVENING...A FEW TORNADOES ALONG WITH LARGE HAIL AND WIND DAMAGE WILL CONTINUE TO BE POSSIBLE. THE SEVERE THREAT SHOULD EVENTUALLY BECOME MARGINAL AS THE CONVECTIVE COMPLEX MOVES EWD INTO IND AFTER MIDNIGHT WHERE INSTABILITY WILL BE WEAKER. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... WATER VAPOR IMAGERY CURRENTLY SHOWS A SUBTLE SHORTWAVE TROUGH ACROSS THE OH VALLEY MOVING INTO THE CNTRL APPALACHIAN MTNS. SCATTERED THUNDERSTORM DEVELOPMENT SHOULD CONTINUE TO OCCUR AHEAD OF THIS FEATURE IN THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS THIS AFTERNOON. OBJECTIVE ANALYSIS ACROSS THE REGION SHOW STRONG VERTICAL SHEAR PROFILES...MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH A POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. STORM COVERAGE ALONG WITH THE SEVERE POTENTIAL SHOULD DECREASE THIS EVENING AS INSTABILITY WEAKENS AND A SHORTWAVE RIDGE APPROACHES FROM THE WEST. ..BROYLES.. 04/15/2006  From SwoDy1 at goshenarc.org Sun Apr 16 01:09:26 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 15 Apr 2006 21:09:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160105 SWODY1 SPC AC 160104 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0804 PM CDT SAT APR 15 2006 VALID 160100Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID/LOWER MO VALLEY EWD TO IL/WRN IND... ...SYNOPSIS... VIGOROUS MID/UPPER LEVEL CLOSED LOW...CURRENTLY LOCATED OVER CENTRAL NEB/NRN KS...AND WITHIN CENTRAL/SRN PLAINS TROUGH IS EXPECTED TO STOP DEEPENING TONIGHT AS IT TRACKS MORE ELY...REACHING IA/NRN MO BY 12Z SUNDAY. ATTENDANT SURFACE LOW SHOULD ALSO BEGIN A WEAKENING PROCESS...BUT SHOULD REMAIN AOB 990 MB BY SUNDAY MORNING AS IT MOVES EWD INTO IA. SURFACE BOUNDARY EXTENDED ESEWD FROM CENTRAL NEB LOW ACROSS THE MID MS/OH VALLEYS TO SRN VA. WRN EXTENT WILL CONTINUE TO MOVE NWD AS A WARM FRONT REACHING SRN IA AND CENTRAL IL/IND BY END OF PERIOD...WHILE KY PORTION REMAINS NEARLY STATIONARY. ERN EXTENT ACROSS VA EXPECTED TO CONTINUE MOVING SSEWD AS A COLD FRONT INTO NC OVERNIGHT. MEANWHILE...DRY LINE TRAILED SSWWD FROM SERN NEB THROUGH ERN KS/CENTRAL OK INTO NORTH CENTRAL TO SW TX. PACIFIC COLD FRONT WILL CONTINUE TO OVERTAKE NEB/KS/NRN OK PORTION OF DRY LINE THIS EVENING/OVERNIGHT...WITH THE FRONT REACHING NWRN MO TO NWRN TX BY SUNDAY MORNING. ...ERN PLAINS/MID MS VALLEY LARGE SCALE ASCENT AHEAD OF CLOSED MID-LEVEL LOW AND WITHIN EXIT REGION OF 60-70 KT WSWLY MID-LEVEL JET TRANSLATING EWD ACROSS THE LOWER MO/MID MS VALLEYS TO OH VALLEY WILL SUPPORT CONTINUATION OF THUNDERSTORMS ENEWD OVERNIGHT. AIR MASS EXPECTED TO REMAIN MODERATELY UNSTABLE FROM SURFACE LOW EWD ALONG WARM FRONT INTO WRN/CENTRAL IL. BACKED LOW-LEVEL WINDS EAST OF SURFACE LOW AND ALONG THE WARM FRONT COMBINED WITH STRENGTHENING SWLY LLJ ACROSS MO INTO CENTRAL IL WILL SUPPORT CONTINUED TORNADO THREAT FROM NERN KS TO SWRN IA EWD TO PARTS OF CENTRAL IL LATE. LARGE HAIL AND DAMAGING WIND GUSTS WILL REMAIN A THREAT AS WELL...WITH THESE THREATS POTENTIALLY EXTENDING AS FAR N AND E AS SERN SD AND CENTRAL/SRN IND...RESPECTIVELY. UPSCALE GROWTH OF ONGOING STORMS ALONG MID/LOWER MO VALLEY IS EXPECTED WITH ONE OR TWO MCS/S MOVING ENEWD AND REACHING SERN MN/SRN WI TO SWRN OH/KY BY 12Z SUNDAY. INSTABILITY...AND ATTENDANT SEVERE THREAT...WILL GRADUALLY DECREASE THIS EVENING WITH SWD EXTENT ALONG DRY LINE/COLD FRONT THROUGH ERN KS/WRN MO TO NERN OK AS LOSS OF INSOLATION STABILIZES BOUNDARY LAYER. ...OH VALLEY REGION TO MID-ATLANTIC STATES... WEAK LOW-LEVEL CONVERGENCE ALONG SURFACE BOUNDARY ACROSS SRN IND TO WV/SWRN VA COMBINED WITH MUCAPE AROUND 1000 J/KG EXPECTED TO SUPPORT ADDITIONAL THUNDERSTORM DEVELOPMENT...GIVEN 30-40 KT EFFECTIVE DEEP LAYER SHEAR. ISOLATED LARGE HAIL/STRONG WIND GUSTS SHOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. ..PETERS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 06:15:46 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 02:15:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160611 SWODY1 SPC AC 160609 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT SUN APR 16 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID MS/OH VALLEYS TO MID-ATLANTIC STATES... ...SYNOPSIS... WELL DEFINED CLOSED UPPER LOW...NOW LOCATED OVER ERN NEB PER WATER VAPOR IMAGERY...IS EXPECTED TO WEAKEN/BECOME AN OPEN WAVE TODAY AS IT MOVES ESEWD THROUGH MID/UPPER RIDGE AXIS ALONG THE MS VALLEY. BAND OF 55-65 KT MID-LEVEL FLOW ALONG SRN PERIPHERY OF THIS TROUGH SHOULD EXTEND FROM THE MID MS VALLEY TO VA/NC BY THIS AFTERNOON. IN THE LOW-LEVELS...SURFACE LOW OVER SWRN IA AT 12Z THIS MORNING WILL TRACK SEWD ALONG WARM FRONT THROUGH CENTRAL/SRN IL THIS AFTERNOON... AND THEN ACROSS SRN IND/NRN KY LATE THIS EVENING/OVERNIGHT. TRAILING COLD FRONT WILL SPREAD EWD ACROSS LOWER MO TO LOWER OH VALLEYS...WITH THE SRN EXTENT MOVING SLOWLY SWD ACROSS THE SRN PLAINS. ...MID MS/OH VALLEYS... AT 12Z TODAY...THUNDERSTORMS SHOULD BE ONGOING FROM PARTS OF THE UPPER MS VALLEY SEWD INTO THE OH VALLEY...PRIMARILY ALONG/N OF SURFACE WARM FRONT. LOW-LEVEL WAA AND LARGE SCALE ASCENT AHEAD OF UPPER TROUGH SHOULD MAINTAIN THIS EARLY ACTIVITY N OF WARM FRONT. SURFACE HEATING EXPECTED IN THE WARM SECTOR COMBINED WITH RESIDUAL MOISTURE /SURFACE DEWPOINTS IN THE UPPER 50S-LOWER 60S/ ALONG THIS BOUNDARY AND STEEP LAPSE RATES WILL SUPPORT MLCAPE VALUES UP TO 2000-2500 J/KG BY EARLY-MID AFTERNOON FROM SERN IA/ERN MO INTO THE OH VALLEY. THERMODYNAMICS COMBINED WITH LARGE SCALE ASCENT AHEAD OF UPPER TROUGH WILL ALLOW NEW THUNDERSTORMS TO DEVELOP BY EARLY AFTERNOON FROM SURFACE LOW SEWD ALONG THE WARM FRONT AND SWD ALONG THE COLD FRONT INTO SERN MO. STRONG DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS WITH SUPERCELLS POSSIBLE ESPECIALLY WITH INITIAL ACTIVITY FROM SERN IA/ERN MO INTO IL WHERE SHEAR VECTORS WILL BE ORIENTED MORE NORMAL TO SURFACE BOUNDARIES. BACKED LOW-LEVEL FLOW VICINITY SURFACE LOW/ALONG WARM FRONT IS EXPECTED TO ENHANCE THE THREAT FOR TORNADOES...WHILE STEEP LAPSE RATES ALSO SUPPORT A THREAT FOR VERY LARGE HAIL WITH SOME OF THE INITIAL STORMS. MODELS SUGGEST UPSCALE GROWTH INTO A FORWARD-PROPAGATING MCS ACROSS IL/IND AND WRN-NRN KY LATER THIS AFTERNOON/EVENING AS LOW-LEVEL JET VEERS AND SHEAR VECTORS BECOME ORIENTED PARALLEL TO WARM FRONT. DAMAGING WINDS SHOULD BECOME THE PRIMARY THREAT WITH THE MCS AS IT TRACKS SEWD THROUGH THE OH VALLEY...POTENTIALLY REACHING WV/WRN VA LATE IN THE PERIOD. STRONGER CAP LOCATED SOUTH OF MID-LEVEL JET AXIS SHOULD LIMIT SWD EXTENT OF SEVERE THREAT ALONG THE COLD FRONT TO THE VICINITY OF THE SERN MO/NERN AR BORDER REGION. ...MID-ATLANTIC STATES... POCKETS OF SURFACE HEATING EXPECTED TO OVERCOME WEAKLY CAPPED AIR MASS BY LATE MORNING/EARLY AFTERNOON TO AID IN THUNDERSTORM DEVELOPMENT ALONG THE SURFACE BOUNDARY. STEEP LAPSE RATES COMBINED WITH SURFACE DEWPOINTS IN THE 50S TO AROUND 60 ALONG THE SURFACE BOUNDARY EXPECTED TO SUPPORT MLCAPE VALUES AROUND 1000 J/KG BY THIS AFTERNOON. FAIRLY DEEP UNI-DIRECTIONAL WIND FIELDS AND STRONG DEEP LAYER SHEAR WILL SUPPORT A THREAT FOR ORGANIZED SEVERE STORMS. GIVEN STORMS SHOULD BE TIED TO SURFACE HEATING... THREAT SHOULD DECREASE AFTER SUNSET AS AIR MASS BEGINS TO STABILIZE WITH THE LOSS OF DAYTIME HEATING. ...NRN HIGH PLAINS... ENTRANCE REGION OF SWLY MID-LEVEL JET THAT MOVED INLAND OVER ORE/NRN CA SATURDAY EVENING PER 00Z UPPER AIR ANALYSIS IS EXPECTED TO BE LOCATED OVER THE NRN HIGH PLAINS BY LATE THIS AFTERNOON/EARLY EVENING. LARGE SCALE ASCENT ASSOCIATED WITH THIS FEATURE WILL AID IN THUNDERSTORM DEVELOPMENT THIS AFTERNOON AS COLD FRONT MOVES EWD ACROSS ERN MT/WY. INCREASING SSELY LOW-LEVEL WINDS BY LATE AFTERNOON/EVENING OVER THE WRN DAKOTAS SHOULD AID IN THE TRANSPORT OF A NARROW PLUME OF MOISTURE BENEATH PLUME OF STEEP LAPSE RATES. THUS...WEAK INSTABILITY MAY SUPPORT AN ISOLATED SEVERE THREAT WITH STORMS THAT FORM ALONG THE COLD FRONT AS IT MOVES EWD ACROSS THE NRN HIGH PLAINS THIS EVENING. ..PETERS/GRAMS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 12:53:46 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 08:53:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161250 SWODY1 SPC AC 161248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT SUN APR 16 2006 VALID 161300Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VLY TO THE NC CST... ...SYNOPSIS... WRN IA CLOSED LOW EXPECTED TO MOVE ESE ACROSS THE REMAINDER OF THAT STATE TODAY...BEFORE ACCELERATING ESE ACROSS IL/IND TONIGHT AS THE SYSTEM WEAKENS AND IS REABSORBED INTO THE WLYS. ASSOCIATED SURFACE LOW SHOULD REACH THE QUINCY AREA BY 00Z SUNDAY AS TRAILING PACIFIC COLD FRONT/DRY LINE SWEEPS E INTO S CNTRL IL. FRONTAL ZONE EXTENDING ESE FROM THE LOW INTO KY AND NC SHOULD BECOME MORE SHARPLY DEFINED TODAY AND LIKELY WILL SHOW LITTLE OVERALL MOVEMENT. ...SRN WI/NRN IL TO LWR OH VLY --- NEAR TERM... WARM ADVECTION/UPLIFT ON DOWNWIND SIDE OF SLIGHTLY ELEVATED INSTABILITY AXIS HAS SUPPORTED DEVELOPMENT OF SCATTERED STORMS OVER PARTS OF IL SWD INTO WRN KY IN THE PAST 2 HRS. SUFFICIENT ELEVATED INSTABILITY IS PRESENT TO SUPPORT SOME HAIL /MUCAPE TO 800 J PER KG/. BUT STORM MERGERS...AND MOVEMENT OF FORCING MECHANISM NEWD BEYOND LLJ/INSTABILITY AXIS...SUGGEST THAT OVERALL SEVERE THREAT WILL BE LIMITED /REF MCD 523/. ...MID MS INTO LWR OH VLY... SURFACE HEATING AND MID LEVEL COLD ADVECTION/ASCENT IN EXIT REGION OF SPEED MAX ROUNDING BASE OF IA LOW EXPECTED TO FOSTER STORM DEVELOPMENT BY EARLY AFTERNOON NEAR SURFACE LOW OVER SE IA/WRN IL AND PERHAPS NE MO. DEEP SHEAR INVOF THIS INITIAL ACTIVITY WILL NOT BE ESPECIALLY STRONG. BUT STEEP LOW TO MID LEVEL LAPSE RATES AND ENHANCED LOW LEVEL VEERING PROFILES NEAR STATIONARY FRONT SUGGEST POTENTIAL FOR HAIL AND POSSIBLY A BRIEF TORNADO OR TWO. WITH CONTINUED HEATING...EXPECT THAT STORMS WILL DEVELOP SWD ALONG COLD FRONT OVER FAR ERN MO...AND ESE ALONG STATIONARY FRONT INTO IL. THIS DEVELOPMENT WILL OCCUR AS AFOREMENTIONED JET STREAK ELONGATES AND RESULTS IN STRENGTHENING OF DEEP SHEAR EWD ALONG STATIONARY FRONT INTO SRN IL/SW IND AND WRN KY. BOUNDARY LAYER MOISTURE AVAILABILITY WILL BE A BIT LIMITED /AVERAGE SURFACE DEWPOINTS AROUND 60 F/ BY COMPARISON TO MORE WIDESPREAD SEVERE WEATHER EVENTS. BUT GIVEN STRONG HEATING...SUFFICIENT MOISTURE WILL BE PRESENT TO YIELD SBCAPE OF 1500-2000 J/KG. WITH 40+ KT DEEP WNWLY SHEAR ORIENTED PARALLEL TO STATIONARY FRONT...A CONCENTRATED AREA OF SUSTAINED SUPERCELLS APPEARS LIKELY. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL/HIGH WIND AND TORNADOES...ESPECIALLY IN S CNTRL IL INTO WRN KY/SW IND. INCREASED CIN WITH SWD EXTENT SHOULD PROHIBIT STORM DEVELOPMENT SWD ALONG COLD FRONT INTO AR/TN. BY THIS EVENING EXPECT THAT THE STORMS WILL HAVE COALESCED INTO A COMPLEX...WITH EMBEDDED SUSTAINED STORMS/POSSIBLE SUPERCELLS IN KY/SRN IND. COUPLED WITH INCREASINGLY UNIDIRECTIONAL WIND FIELD AND ORIENTATION OF LOW LEVEL INSTABILITY AXIS EXTENDING TO THE ESE...THE SETUP COULD SUPPORT EVOLUTION INTO A FORWARD-PROPAGATING SQUALL LINE. IF SUCH A SYSTEM DEVELOPS...AN ATTENDANT THREAT FOR HIGH WIND AND HAIL COULD REACH THE WRN SLOPES OF THE CNTRL/SRN APPALACHIANS EARLY MONDAY. ...WV/SW VA INTO NC... A SECONDARY FOCUS FOR STRONG...MAINLY DIURNAL STORM DEVELOPMENT WILL EXIST ALONG AND JUST S OF ERN EXTENSION OF SAME FRONT AFFECTING THE OH VLY. THE DIFFUSE FRONT SHOULD BECOME STATIONARY FROM SRN WV INTO ERN NC LATER TODAY. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK AT BEST...AND INITIATION MAY BE TIED MORE TO OROGRAPHIC SOURCES THAN TO FRONT. BUT COMBINATION OF STRONG SURFACE HEATING WITH RELATIVELY STEEP MID LEVEL LAPSE RATES AND 40-50 KT DEEP UNIDIRECTIONAL WNWLY SHEAR WILL BE FAVORABLE FOR WIDELY SCATTERED SUSTAINED STORMS/SUPERCELLS WITH HAIL/HIGH WIND. ...NRN GRT BASIN TO NRN HI PLNS... BROAD...FAIRLY STRONG E PACIFIC TROUGH WILL MOVE INLAND THIS PERIOD AS EMBEDDED SHORTWAVE IMPULSE NOW ENTERING NRN CA CONTINUES E INTO NV. ELSEWHERE...ASCENT WILL ALSO INCREASE OVER ERN MT/WRN ND...IN ENTRANCE REGION OF DOWNSTREAM JET STREAK OVER SASKATCHEWAN. COMBINATION OF SURFACE HEATING WITH INCREASING LARGE SCALE ASCENT SHOULD FOSTER STORM DEVELOPMENT ALONG ASSOCIATED COLD FRONT FROM THE NRN HI PLNS SWWD INTO THE NRN GRT BASIN. THERMODYNAMIC AND KINEMATIC ENVIRONMENT SUGGEST POTENTIAL FOR A FEW STORMS WITH SEVERE OR NEAR SEVERE WINDS ALONG THIS CORRIDOR LATER TODAY THROUGH EARLY TONIGHT. ..CORFIDI/GRAMS.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 13:03:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 09:03:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161259 SWODY1 SPC AC 161258 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT SUN APR 16 2006 VALID 161300Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF IL...WRN KY AND SW IND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VLY TO THE NC CST... CORRECTED FOR PARTS OF STATES IN MDT RISK ...SYNOPSIS... WRN IA CLOSED LOW EXPECTED TO MOVE ESE ACROSS THE REMAINDER OF THAT STATE TODAY...BEFORE ACCELERATING ESE ACROSS IL/IND TONIGHT AS THE SYSTEM WEAKENS AND IS REABSORBED INTO THE WLYS. ASSOCIATED SURFACE LOW SHOULD REACH THE QUINCY AREA BY 00Z SUNDAY AS TRAILING PACIFIC COLD FRONT/DRY LINE SWEEPS E INTO S CNTRL IL. FRONTAL ZONE EXTENDING ESE FROM THE LOW INTO KY AND NC SHOULD BECOME MORE SHARPLY DEFINED TODAY AND LIKELY WILL SHOW LITTLE OVERALL MOVEMENT. ...SRN WI/NRN IL TO LWR OH VLY --- NEAR TERM... WARM ADVECTION/UPLIFT ON DOWNWIND SIDE OF SLIGHTLY ELEVATED INSTABILITY AXIS HAS SUPPORTED DEVELOPMENT OF SCATTERED STORMS OVER PARTS OF IL SWD INTO WRN KY IN THE PAST 2 HRS. SUFFICIENT ELEVATED INSTABILITY IS PRESENT TO SUPPORT SOME HAIL /MUCAPE TO 800 J PER KG/. BUT STORM MERGERS...AND MOVEMENT OF FORCING MECHANISM NEWD BEYOND LLJ/INSTABILITY AXIS...SUGGEST THAT OVERALL SEVERE THREAT WILL BE LIMITED /REF MCD 523/. ...MID MS INTO LWR OH VLY... SURFACE HEATING AND MID LEVEL COLD ADVECTION/ASCENT IN EXIT REGION OF SPEED MAX ROUNDING BASE OF IA LOW EXPECTED TO FOSTER STORM DEVELOPMENT BY EARLY AFTERNOON NEAR SURFACE LOW OVER SE IA/WRN IL AND PERHAPS NE MO. DEEP SHEAR INVOF THIS INITIAL ACTIVITY WILL NOT BE ESPECIALLY STRONG. BUT STEEP LOW TO MID LEVEL LAPSE RATES AND ENHANCED LOW LEVEL VEERING PROFILES NEAR STATIONARY FRONT SUGGEST POTENTIAL FOR HAIL AND POSSIBLY A BRIEF TORNADO OR TWO. WITH CONTINUED HEATING...EXPECT THAT STORMS WILL DEVELOP SWD ALONG COLD FRONT OVER FAR ERN MO...AND ESE ALONG STATIONARY FRONT INTO IL. THIS DEVELOPMENT WILL OCCUR AS AFOREMENTIONED JET STREAK ELONGATES AND RESULTS IN STRENGTHENING OF DEEP SHEAR EWD ALONG STATIONARY FRONT INTO SRN IL/SW IND AND WRN KY. BOUNDARY LAYER MOISTURE AVAILABILITY WILL BE A BIT LIMITED /AVERAGE SURFACE DEWPOINTS AROUND 60 F/ BY COMPARISON TO MORE WIDESPREAD SEVERE WEATHER EVENTS. BUT GIVEN STRONG HEATING...SUFFICIENT MOISTURE WILL BE PRESENT TO YIELD SBCAPE OF 1500-2000 J/KG. WITH 40+ KT DEEP WNWLY SHEAR ORIENTED PARALLEL TO STATIONARY FRONT...A CONCENTRATED AREA OF SUSTAINED SUPERCELLS APPEARS LIKELY. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL/HIGH WIND AND TORNADOES...ESPECIALLY IN S CNTRL IL INTO WRN KY/SW IND. INCREASED CIN WITH SWD EXTENT SHOULD PROHIBIT STORM DEVELOPMENT SWD ALONG COLD FRONT INTO AR/TN. BY THIS EVENING EXPECT THAT THE STORMS WILL HAVE COALESCED INTO A COMPLEX...WITH EMBEDDED SUSTAINED STORMS/POSSIBLE SUPERCELLS IN KY/SRN IND. COUPLED WITH INCREASINGLY UNIDIRECTIONAL WIND FIELD AND ORIENTATION OF LOW LEVEL INSTABILITY AXIS EXTENDING TO THE ESE...THE SETUP COULD SUPPORT EVOLUTION INTO A FORWARD-PROPAGATING SQUALL LINE. IF SUCH A SYSTEM DEVELOPS...AN ATTENDANT THREAT FOR HIGH WIND AND HAIL COULD REACH THE WRN SLOPES OF THE CNTRL/SRN APPALACHIANS EARLY MONDAY. ...WV/SW VA INTO NC... A SECONDARY FOCUS FOR STRONG...MAINLY DIURNAL STORM DEVELOPMENT WILL EXIST ALONG AND JUST S OF ERN EXTENSION OF SAME FRONT AFFECTING THE OH VLY. THE DIFFUSE FRONT SHOULD BECOME STATIONARY FROM SRN WV INTO ERN NC LATER TODAY. LARGE SCALE FORCING FOR ASCENT WILL REMAIN WEAK AT BEST...AND INITIATION MAY BE TIED MORE TO OROGRAPHIC SOURCES THAN TO FRONT. BUT COMBINATION OF STRONG SURFACE HEATING WITH RELATIVELY STEEP MID LEVEL LAPSE RATES AND 40-50 KT DEEP UNIDIRECTIONAL WNWLY SHEAR WILL BE FAVORABLE FOR WIDELY SCATTERED SUSTAINED STORMS/SUPERCELLS WITH HAIL/HIGH WIND. ...NRN GRT BASIN TO NRN HI PLNS... BROAD...FAIRLY STRONG E PACIFIC TROUGH WILL MOVE INLAND THIS PERIOD AS EMBEDDED SHORTWAVE IMPULSE NOW ENTERING NRN CA CONTINUES E INTO NV. ELSEWHERE...ASCENT WILL ALSO INCREASE OVER ERN MT/WRN ND...IN ENTRANCE REGION OF DOWNSTREAM JET STREAK OVER SASKATCHEWAN. COMBINATION OF SURFACE HEATING WITH INCREASING LARGE SCALE ASCENT SHOULD FOSTER STORM DEVELOPMENT ALONG ASSOCIATED COLD FRONT FROM THE NRN HI PLNS SWWD INTO THE NRN GRT BASIN. THERMODYNAMIC AND KINEMATIC ENVIRONMENT SUGGEST POTENTIAL FOR A FEW STORMS WITH SEVERE OR NEAR SEVERE WINDS ALONG THIS CORRIDOR LATER TODAY THROUGH EARLY TONIGHT. ..CORFIDI.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 16:38:53 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 12:38:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161635 SWODY1 SPC AC 161633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT SUN APR 16 2006 VALID 161630Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PART OF IL INTO SWRN IND AND FAR NWRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM IA TO THE NC/VA COAST... ...IA INTO THE OH RIVER VALLEY... STRONG UPPER SYSTEM WITH NEARLY VERTICALLY STACKED LOW CENTER NOW OVER CENTRAL IA WILL TRACK ESEWD ACROSS CENTRAL IL...WITH TRAILING SURFACE TROUGH ADVANCING ESEWD ACROSS THE MID MS RIVER VALLEY TODAY. THIS WILL SUPPORT WIDESPREAD SEVERE THUNDERSTORMS INTO ERN IA AND MUCH OF IL THIS AFTERNOON...SPREADING INTO WRN IN/NRN KY THIS EVENING. BOTH DEEP LAYER SHEAR AND MID LEVEL LAPSE RATES REMAIN QUITE IMPRESSIVE ACCORDING TO OBSERVED AND FORECAST SOUNDINGS. 12Z NAM CONTINUES TO OVERFORECAST SURFACE DEW POINTS AHEAD OF THIS SYSTEM. HOWEVER...COLD TEMPERATURES ALOFT/STEEP LAPSE RATES ALONG WITH VERY STRONG LARGE SCALE ASCENT SUGGEST LOWER 60F SURFACE DEW POINTS WILL BE MORE THAN ADEQUATE FOR MODERATE INSTABILITY AND AN ENHANCED SEVERE THUNDERSTORM THREAT TODAY. DEVELOPMENT WILL LIKELY OCCUR IN TWO DIFFERENT MODES. ONE WILL BE UNDER COLD UPPER LOW WHERE VERY STRONG AMBIENT VORTICITY AND STEEP LOW LEVEL LAPSE RATES/MODERATE SFC-3 KM CAPE WILL BE FOUND. DEVELOPMENT IS ALREADY INCREASING IN THIS ENVIRONMENT ACROSS CENTRAL IA AND WILL SHIFT INTO NERN MO/ERN IA AND WRN IL THROUGH THE DAY. ADDITIONAL DEVELOPMENT IS EXPECTED TO OCCUR ALONG SURFACE WARM FRONT EXTENDING INTO CENTRAL IND AND AHEAD OF SURFACE TROUGH ADVANCING INTO ERN MO DURING THE AFTERNOON. SHEAR PARAMETERS ARE STRONGER ACROSS THIS REGION AND LOW LEVEL SHEAR WILL REMAIN STRONG DESPITE DEEP WLY COMPONENT. GIVEN AMOUNT OF SHEAR...MLCAPE SHOULD EXCEED 1500 J/KG AND SUPPORT SUPERCELLS ACROSS THIS REGION...WITH EVENTUAL EVOLUTION INTO ONE OR MORE LEWP STRUCTURES. TORNADO THREAT WILL REMAIN HIGHEST NEAR THE WARM FRONT/AHEAD OF LOW CENTER WHERE STRONG PRESSURE FALLS AND BACKED SURFACE WINDS WILL ENHANCE LOW LEVEL HELICITY...THOUGH ISOLATED TORNADOES WILL LIKELY OCCUR WITH WARM SECTOR DEVELOPMENT INTO THE OH RIVER VALLEY. LARGE MCS SHOULD DEVELOP AND SPREAD ESEWD INTO THE IND AND SWRN OH/KY THROUGH THE EVENING. DAMAGING WINDS MAY ALSO BECOME WIDESPREAD WITH THIS MCS AS ACTIVITY ORGANIZES ALONG LEADING OUTFLOW BOUNDARY. ...WV/ERN KY INTO SRN VA/NC... SEVERE THREAT WILL REMAIN ALONG STALLED SURFACE FRONT EXTENDING WNW-ESE ACROSS THIS REGION TODAY. WITH LIMITED LARGE SCALE ASCENT AND MODEST CAPPING ON 12Z SOUNDINGS...ACTIVITY WILL LIKELY BE STRONGLY DRIVEN BY DIURNAL HEATING. HOWEVER...DEEP LAYER SHEAR REMAINS STRONG WITH EFFECTIVE BULK SHEAR EXCEEDING 40 KT. IN ADDITION...STEEP LAPSE RATES AND 55-60F SURFACE DEW POINTS SHOULD SUPPORT MODEST INSTABILITY BY THE MID TO LATE AFTERNOON. LARGE HAIL AND DAMAGING WINDS WILL REMAIN PRIMARY SEVERE THREATS WITH FAIRLY HIGH-BASED STORMS AS THEY SPREAD ESEWD THROUGH THE EVENING. HOWEVER...AN ISOLATED TORNADO COULD OCCUR GIVEN LOCATION OF SURFACE BOUNDARY/INCREASED LOW LEVEL SHEAR AND LIKELIHOOD OF PERSISTENT SUPERCELL STRUCTURES. ..EVANS/GUYER.. 04/16/2006  From SwoDy1 at goshenarc.org Sun Apr 16 20:05:24 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 16:05:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 162001 SWODY1 SPC AC 161959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT SUN APR 16 2006 VALID 162000Z - 171200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF IL...IND AND WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST...OH VALLEY...CNTRL APPALACHIANS AND ATLANTIC COASTAL PLAINS... ...UPPER MIDWEST/OH VALLEY... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW AN UPPER-LEVEL LOW OVER THE MID-MS VALLEY WITH STRONG LARGE-SCALE ASCENT CURRENTLY SPREADING EWD ACROSS THE OH VALLEY. A LINE OF INTENSE STORMS WRAPPING AROUND THE SYSTEM IS ONGOING AND WILL CONTINUE TO MOVE EWD ACROSS THE MODERATE RISK AREA. THE AIRMASS IS CHARACTERIZED BY MODERATE INSTABILITY AND STRONG VERTICAL SHEAR WHICH WILL BE VERY SUPPORTIVE OF SUPERCELLS. THE POTENTIAL FOR SUPERCELLS WILL INCREASE SWD ACROSS ERN IL AS INTENSIFICATION OF THE LINE CONTINUES. SUPERCELLS WILL ALSO BE POSSIBLE AHEAD OF THE LINE ACROSS IND ALONG THE NRN EDGE OF THE INSTABILITY GRADIENT. SFC DEWPOINTS IN THE 60S F COMBINED WITH STRONG VERTICAL SHEAR AND THE MODERATE INSTABILITY WILL MAKE THE STRONGER STORMS CAPABLE OF PRODUCING TORNADOES...LARGE HAIL AND WIND DAMAGE. A FEW OF THE MORE INTENSE SUPERCELLS WILL LIKELY BE CAPABLE OF VERY LARGE HAIL AND VERY HIGH WINDS. AS THE UPPER-TROUGH CONTINUES ESEWD LATE THIS AFTERNOON...THE SEVERE THREAT SHOULD EXPAND ESEWD ACROSS THE MODERATE RISK AREA. THE WIND DAMAGE POTENTIAL MAY BECOME ENHANCED AS A LARGE MCS DEVELOPS AND MOVES ESEWD ACROSS THE SERN PART OF THE MODERATE RISK AREA THIS EVENING. THE SEVERE THREAT SHOULD GRADUALLY DROP OFF OVERNIGHT AS INSTABILITY WEAKENS AND THE MCS APPROACHES THE CNTRL APPALACHIAN MTNS. ...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS... A SHORTWAVE RIDGE IS EVIDENT ON WATER VAPOR OVER THE CNTRL APPALACHIANS AHEAD OF AN APPROACHING UPPER-LEVEL LOW/TROUGH OVER THE LOWER OH VALLEY. SCATTERED THUNDERSTORMS ARE ONGOING IN THE APPALACHIANS AND UNDER THE RIDGE WHERE LARGE-SCALE ASCENT IS RELATIVELY WEAK. EVEN SO...INSTABILITY AND STRONG VERTICAL SHEAR SHOULD BE SUPPORTIVE OF A FEW SEVERE STORMS LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE GREATEST THREAT OF SEVERE WILL BE ALONG THE INSTABILITY AXIS EXTENDING SEWD FROM ERN KY ACROSS SRN WV INTO CNTRL AND ERN NC. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER CELLS WITH THE SEVERE THREAT GRADUALLY DECREASING THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/16/2006  From SwoDy1 at goshenarc.org Mon Apr 17 01:04:17 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 16 Apr 2006 21:04:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170100 SWODY1 SPC AC 170058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 PM CDT SUN APR 16 2006 VALID 170100Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY... ...OH VALLEY... CLOSED UPPER LOW...NOW LOCATED OVER ERN IA...WILL CONTINUE TO DE-AMPLIFY AS IT EVOLVES INTO AN OPEN WAVE TRACKING SEWD INTO THE LOWER OH VALLEY...REACHING SRN IND/OH REGION BY 12Z MONDAY. IN THE LOW-LEVELS...A SURFACE LOW WAS LOCATED OVER CENTRAL/SRN IL WITH A WARM FRONT EXTENDING ESEWD THROUGH CENTRAL/SRN IND TO SWRN OH AND SRN WV. SURFACE LOW IS EXPECTED TO TRACK ALONG THIS BOUNDARY INTO SRN IND THIS EVENING AND THEN REACHING ERN KY TOWARD 12Z. 50-60 KT WNWLY MID-LEVEL JET OVER NRN MO WILL TRANSLATE ESEWD INTO KY MAINTAINING LARGE SCALE ASCENT WITHIN EXIT REGION FOR ADDITIONAL THUNDERSTORMS SEWD ACROSS SRN IND...CENTRAL/ERN KY AND SWRN OH. GRADUAL DECREASE IN AVAILABLE CONVECTIVE INSTABILITY/BOUNDARY LAYER STABILIZATION...GIVEN LOSS OF DAYTIME HEATING...SUGGESTS OVERALL SEVERE THREAT SHOULD BEGIN TO DECREASE GENERALLY AFTER 03Z. UNTIL THEN...40-50 KT SWLY LLJ ALONG THE LOWER OH VALLEY AND BENEATH WNWLY MID-LEVEL FLOW WILL CONTINUE TO SUPPORT SUPERCELLS WITH AN ATTENDANT TORNADO POTENTIAL FOR THE NEXT COUPLE OF HOURS AS ACTIVITY SPREADS ESEWD ACROSS SRN IND INTO PARTS OF NWRN-NRN KY. HAIL/DAMAGING WINDS WILL ALSO REMAIN A THREAT WITH THE ACTIVITY THIS EVENING. VEERING LLJ OVERNIGHT AND DECREASING TREND IN DEEP LAYER SHEAR/INSTABILITY SHOULD LIMIT SEVERE THREAT WITH ANY THUNDERSTORMS LATER IN THE PERIOD. HOWEVER...WEAK INSTABILITY AND 25-35 KT OF EFFECTIVE DEEP LAYER SHEAR MAY SUPPORT A FEW ISOLATED STRONG TO SEVERE STORMS WITH STRONG WIND GUSTS/MARGINALLY SEVERE HAIL THE PRIMARY THREATS AS STORMS SPREAD INTO SRN OH/ERN KY. ...MID-ATLANTIC STATES... WATER VAPOR IMAGERY INDICATED AN APPARENT MID-LEVEL IMPULSE LOCATED OVER VA/NRN NC AT 00Z. THE COMBINATION OF THIS FEATURE MOVING OFFSHORE IN THE NEXT FEW HOURS AND CONTINUATION OF BOUNDARY LAYER STABILIZATION IS EXPECTED TO DIMINISH THREAT FOR ADDITIONAL THUNDERSTORMS WITH ATTENDANT SEVERE POTENTIAL. ..PETERS.. 04/17/2006  From SwoDy1 at goshenarc.org Mon Apr 17 05:49:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 17 Apr 2006 01:49:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170545 SWODY1 SPC AC 170544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON APR 17 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS MAINLY THIS AFTERNOON ACROSS NC/SC... ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF NEB/SD/ND... ...NC/SC... OH VALLEY MID-LEVEL TROUGH WILL UNDERGO FURTHER DE-AMPLIFICATION TODAY AS IT TRACKS ESEWD TOWARD VA/NC/SC...EVENTUALLY BECOMING ABSORBED BY NERN STATES UPPER TROUGH...AND EJECTING EWD OVER THE WRN ATLANTIC. ACCOMPANYING BAND OF STRONG WLY MID-LEVEL WINDS AT 60-65 KT WILL TRANSLATE EWD ACROSS NC/SC THIS MORNING/AFTERNOON. IN THE LOW-LEVELS...SURFACE BOUNDARY INITIALLY EXTENDING W-E OVER NRN NC IS EXPECTED TO MOVE SSE ACROSS THE CAROLINAS AND SHOULD BE THE PRIMARY FOCUS FOR THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING AS IT MOVES SWD ACROSS NC/SC. SURFACE LOW EXPECTED TO BE LOCATED OVER ERN KY AT 12Z TODAY WILL WEAKEN AS IT MOVES INTO WV. DOWNSTREAM HEIGHT FALLS SHOULD AID SECONDARY SURFACE WAVE DEVELOPMENT ALONG SURFACE FRONT IN WRN/CENTRAL NC THIS MORNING BEFORE THIS LOW TRACKS OFFSHORE BY 00Z WITH THE FRONT. DESPITE MODEST MID-LEVEL LAPSE RATES ACROSS THE CAROLINAS...STRONG SURFACE HEATING EXPECTED S OF COLD FRONT AND SURFACE DEWPOINTS POTENTIALLY NEAR 60 F SHOULD SUPPORT MODERATE INSTABILITY BY AFTERNOON. THUNDERSTORMS MAY BE ONGOING OVER WV/NERN TN AT START OF DAY 1 PERIOD...WITH THIS ACTIVITY TRACKING ESEWD ACROSS THE HIGHER TERRAIN AND THEN INTO SRN VA/NRN NC THIS MORNING WITHIN WEAK WAA REGIME. ADDITIONAL STORMS EXPECTED TO DEVELOP AS COLD FRONT MOVES SWD INTO MODERATELY UNSTABLE AIR MASS. STRONG DEEP LAYER SHEAR VECTORS ORIENTED PARALLEL TO THE FRONT SUGGEST STORM MODE SHOULD BE LINEAR...BUT HIGH SHEAR VALUES MAY SUPPORT A FEW EMBEDDED SUPERCELLS. HAIL WILL BE POSSIBLE WITH THE STRONGEST ACTIVITY... WHILE STEEP LOW-LEVEL LAPSE RATES SHOULD ENHANCE STRONG WIND GUST POTENTIAL. SEVERE THREAT SHOULD DIMINISH BY 00Z AS FRONT MOVES OFFSHORE. ...ND/SD/NEB... SHORT WAVE TROUGH...CURRENTLY MOVING INLAND OVER NRN CA PER WATER VAPOR IMAGERY...WITHIN BASE OF WRN STATES LONG WAVE TROUGH...IS EXPECTED TO MOVE EWD WITH MAIN TROUGH APPROACHING THE CENTRAL/NRN HIGH PLAINS BY 12Z TUESDAY. SURFACE CYCLOGENESIS IS EXPECTED OVER ERN WY IN RESPONSE TO HEIGHT FALLS IN ADVANCE OF THE APPROACHING UPPER TROUGH. THIS LOW SHOULD BE LOCATED ALONG THE INTERSECTION OF A LEE-SIDE TROUGH AND A PACIFIC COLD FRONT WHICH SHOULD EXTEND FROM WRN ND INTO NRN WY BY LATE THIS AFTERNOON. THIS LOW WILL THEN DEVELOP/TRACK SEWD INTO THE CENTRAL PLAINS ALONG A NWD RETREATING WARM FRONT. STRENGTHENING SELY LOW-LEVEL WINDS ACROSS THE CENTRAL/NRN PLAINS WILL LIKELY ADVECT RESIDUAL MOISTURE /SURFACE DEWPOINTS IN THE LOWER 50S CURRENTLY LOCATED OVER EAST CENTRAL PLAINS/ NWWD INTO WRN PORTIONS OF SD/NEB BY LATE AFTERNOON. STEEP MID-LEVEL LAPSE RATES OVER WRN PORTIONS OF THE NRN/CENTRAL PLAINS ATOP THE MOISTURE RETURN WILL SUPPORT A NARROW AXIS OF MUCAPES AROUND 1000 J/KG EXTENDING NNWWD ACROSS THE SLIGHT RISK AREA BY LATE AFTERNOON/EARLY EVENING. THUNDERSTORMS SHOULD DEVELOP IN THE VICINITY OF THE SURFACE LOW OVER NERN WY TO SWRN ND BY LATE AFTERNOON AS LARGE SCALE ASCENT SPREADS ACROSS REGION AHEAD OF UPPER TROUGH. SEVERE THREAT WILL LIKELY BE ISOLATED WITH INITIAL ACTIVITY...SINCE INSTABILITY SHOULD BE WEAKER DUE TO LESS BOUNDARY LAYER MOISTURE WITHIN A DEEPLY MIXED ENVIRONMENT. A GREATER SEVERE THREAT IS EXPECTED AS THE COLD FRONT MOVES EWD INTO THE INSTABILITY AXIS ACROSS WRN PORTIONS OF SD/NEB THIS EVENING/OVERNIGHT. STRONG DEEP LAYER SHEAR WILL SUPPORT STORM ORGANIZATION WITH HAIL AND STRONG WIND GUSTS THE PRIMARY THREATS...WITH ACTIVITY POTENTIALLY BECOMING MORE ELEVATED WITH EWD EXTENT. ..PETERS/GRAMS.. 04/17/2006  From SwoDy1 at goshenarc.org Tue Apr 18 00:52:59 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 17 Apr 2006 20:52:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180049 SWODY1 SPC AC 180047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CDT MON APR 17 2006 VALID 180100Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE NRN HIGH PLAINS... ...WRN DAKOTAS/NWRN-NRN NEB... VIGOROUS SHORT WAVE TROUGH MOVING INTO SWRN WY...AND LOCATED WITHIN BASE OF COLD UPPER TROUGH OVER THE NRN INTERMOUNTAIN WEST/NRN ROCKIES...WILL BECOME MORE NEGATIVELY TILTED OVERNIGHT AS IT APPROACHES THE NRN HIGH PLAINS. SSELY LLJ IS PROGGED TO STRENGTHEN TO 60 KT ACROSS THE CENTRAL/NRN PLAINS IN RESPONSE TO HEIGHT FALLS AHEAD OF THE UPPER TROUGH. EARLY EVENING SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING FROM WRN ND SWWD THROUGH ERN WY TO WRN CO/SERN UT...WITH THIS BOUNDARY MOVING EWD INTO THE PLAINS TONIGHT. SURFACE LOW...NOW LOCATED OVER FAR SERN WY EXPECTED TO DEVELOP SEWD ALONG WARM FRONT INTO CENTRAL KS BY 12Z TUESDAY. INCREASINGLY DIFFLUENT FLOW AHEAD OF NEGATIVELY TILTED TROUGH AND STRENGTHENING WAA REGIME WITH STRONG LLJ WILL SUPPORT CONTINUED THUNDERSTORM DEVELOPMENT OVERNIGHT AS THE COLD FRONT MOVES EWD. SURFACE-BASED STORMS WILL REMAIN POSSIBLE ALONG THE COLD FRONT THIS EVENING...WITH STORMS BECOMING MORE ELEVATED LATER THIS EVENING/ TONIGHT AS THE BOUNDARY LAYER COOLS. STRONG DEEP LAYER SHEAR VECTORS INITIALLY ORIENTED MORE NORMAL TO COLD FRONT WILL SUPPORT DISCRETE STORMS FOR A FEW MORE HOURS...WITH EVENTUAL EVOLUTION INTO A LINEAR MODE AS VECTORS BECOME ORIENTED PARALLEL TO FRONT. LARGE HAIL AND STRONG WIND GUSTS EXPECTED TO REMAIN PRIMARY THREATS GIVEN STEEP LAPSE RATES...WITH HAIL BECOMING MAIN THREAT OVERNIGHT AS ELEVATED ACTIVITY POTENTIALLY REACHES CENTRAL PARTS OF ND/SD/NRN NEB. ...SC... SEVERE THREAT HAS ENDED ACROSS THE CAROLINAS AS STRONGEST FORCING HAS SHIFTED OFFSHORE. A FEW THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS MAINLY SRN SC FOR THE NEXT COUPLE OF HOURS AS WEAK WAA PERSISTS ALONG TRAILING PORTION OF COLD FRONT /ANALYZED FROM NEAR CHS-GSP AT 00Z/ MOVING SWD THROUGH THIS REGION. CONTINUED AIR MASS STABILIZATION SHOULD PRECLUDE ADDITIONAL SEVERE THREAT. ..PETERS.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 06:05:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 02:05:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180602 SWODY1 SPC AC 180600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT TUE APR 18 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO VALLEY TO THE OZARKS/LOWER TN VALLEY REGION... ...SYNOPSIS... HIGH AMPLITUDE LARGE SCALE PATTERN WILL CONTINUE ACROSS THE U.S. TODAY...CHARACTERIZED BY OMEGA BLOCK EXTENDING FROM WRN ATLANTIC WWD TO THE PLAINS. WRN EXTENT OF THIS BLOCKING PATTERN WILL BE A MID/ UPPER LEVEL TROUGH MOVING EWD AND INTENSIFYING INTO A CLOSED LOW ACROSS NRN/CENTRAL PLAINS. 80+ KT MID-LEVEL JET WITH THIS SYSTEM WILL TRANSLATE NEWD TODAY AND EXTEND FROM WRN KS TO MID MO VALLEY BY EARLY EVENING. IN THE LOW-LEVELS...OCCLUSION OF NRN MOST SURFACE LOW IS EXPECTED OVER THE ERN DAKOTAS THIS MORNING AS STRONG COLD FRONT OVERTAKES NRN EXTENT OF WARM FRONT WHICH WILL EXTEND ALONG THE MID/LOWER MO VALLEY INTO THE LOWER TN VALLEY AND SERN STATES. SECONDARY SURFACE LOW AT OCCLUSION POINT OF PROGRESSIVE COLD FRONT IS EXPECTED TO BE LOCATED ACROSS NWRN MO BY LATE AFTERNOON...WITH THIS LOW TRACKING SEWD INTO LOWER TN VALLEY TONIGHT. ...MID AND LOWER MO VALLEY INTO OZARKS/LOWER TN VALLEY... LATEST SURFACE OBSERVATIONS INDICATED DEWPOINTS IN THE UPPER 60S AS FAR NORTH AS SERN OK/SRN AR. SLY LOW-LEVEL FLOW WITHIN THE WARM SECTOR WILL ALLOW THIS MOISTURE TO RETURN NWD TODAY WITH UPPER 60S DEWPOINTS POTENTIALLY REACHING AS FAR N AS CENTRAL/NRN MO THIS AFTERNOON. PLUME OF STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH THE NRN/CENTRAL PLAINS UPPER SYSTEM WILL ADVECT EWD CAPPING THE WARM SECTOR THROUGH MUCH OF THE DAY. THESE LAPSE RATES COMBINED WITH STRONG SURFACE HEATING AND SURFACE DEWPOINTS IN THE 60S EXPECTED TO RESULT IN SBCAPE AOA 3000 J/KG FROM MO SSWWD TO THE ARKLATEX REGION. THUNDERSTORMS MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ACROSS PARTS OF THE CENTRAL/ERN DAKOTAS. LARGE SCALE ASCENT AHEAD OF THE INTENSIFYING UPPER TROUGH AND LOW-LEVEL WAA SHOULD SUPPORT A CONTINUATION OF THIS ACTIVITY EWD TOWARD SWRN MN AND SEWD DEVELOPMENT INTO ERN NEB/WRN IA WITH GRADUAL INCREASE IN COVERAGE. FORECAST SOUNDINGS SUGGEST THIS ACTIVITY SHOULD REMAIN ELEVATED GIVEN COOLER/MORE STABLE BOUNDARY LAYER. STEEP MID-LEVEL LAPSE RATES WITH MODERATE ELEVATED INSTABILITY WILL SUPPORT HAIL AS THE PRIMARY THREAT WITH THIS ACTIVITY. SURFACE BASED STORM DEVELOPMENT IS EXPECTED INITIALLY NEAR THE SECONDARY SURFACE LOW/OCCLUSION POINT OVER NWRN MO BY MID-LATE AFTERNOON...AND THEN SWD ACROSS WRN MO TO FAR ERN OK/WRN AR AS THE COLD FRONT MOVES EWD. ALTHOUGH THE WARM SECTOR IS EXPECTED TO BE LOCATED S OF STRONGER FLOW ALOFT...DEEP LAYER SHEAR VECTORS WILL BE SUFFICIENT FOR SUPERCELLS GIVEN THE STRONG INSTABILITY. ANY STORMS THAT DEVELOP/MOVE IN THE VICINITY OF THE OCCLUSION POINT AND WARM FRONT WILL ENCOUNTER STRONG LOW-LEVEL SHEAR /0-3 KM SRH 250-400 M2/S2/ FOR AN ENHANCED TORNADO THREAT...WITH A FEW POTENTIALLY STRONG. LARGE HAIL...SOME VERY LARGE...WILL BE LIKELY ACROSS MUCH OF MO/NRN AR...AND WITH ACTIVITY THAT SPREADS EWD INTO WRN IL THIS EVENING. POTENTIAL EXISTS FOR UPSCALE GROWTH INTO AN MCS THIS EVENING/ OVERNIGHT EWD ACROSS MID MS/LOWER OH VALLEYS. GREATEST SEVERE THREAT SHOULD BE ALONG SWRN PERIPHERY OF THIS MCS ACROSS SERN MO/ NRN-ERN AR AS SECONDARY SURFACE LOW TRACKS TOWARD THE LOWER TN VALLEY. LLJ VEERING TO SWLY AND INCREASING ACROSS AR INTO SRN IL WILL MAINTAIN THREAT FOR TORNADOES THROUGH THIS REGION INTO THE MID-LATE EVENING...IN ADDITION TO LARGE HAIL/DAMAGING WINDS. ...FL NWWD INTO SWRN GA/PARTS OF AL... BOUNDARY WILL EXTEND FROM WRN TN ACROSS AL/SWRN GA. SRN EXTENT IS EXPECTED TO MOVE SWD THROUGH THE NRN-ERN PORTIONS OF THE FL PENINSULA. STRONG SURFACE HEATING ALONG THIS BOUNDARY COMBINED WITH RICH MOISTURE EXPECTED TO SUPPORT MODERATE INSTABILITY. WATER VAPOR IMAGERY INDICATED A WEAK MID-LEVEL IMPULSE CURRENTLY OVER THE ARKLATEX REGION. LARGE SCALE ASCENT WITH THIS FEATURE AS IT TRACKS SEWD TOWARD FL COMBINED WITH STRONG SURFACE HEATING ALONG THE SURFACE BOUNDARY EXPECTED TO SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT. STRONG DEEP LAYER SHEAR WITHIN NW FLOW REGIME SHOULD ALLOW FOR A FEW STRONG TO SEVERE STORMS INTO THE EARLY EVENING. ..PETERS/JEWELL.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 12:56:34 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 08:56:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181253 SWODY1 SPC AC 181251 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 AM CDT TUE APR 18 2006 VALID 181300Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF MO... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MO VLY...S AND SE INTO AR AND THE TN VLY... ...SYNOPSIS... AN OMEGA BLOCK WILL EVOLVE OVER THE AREA FROM THE RCKYS TO THE WRN ATLANTIC THIS PERIOD AS POTENT SHORTWAVE TROUGH NOW OVER THE NRN HI PLNS MOVES E AND CLOSES OFF OVER SD. CYCLONICALLY CURVED 70-80 KT MID LEVEL JET ROUNDING BASE OF TROUGH WILL SHIFT E/NE ACROSS THE CNTRL PLNS/UPR MS VLY AS A WEAKER...MORE WLY...BAND OF FLOW OVERSPREADS THE SRN PLNS...AR AND THE LWR MS VLY. AT THE SURFACE...STRONG COLD FRONT NOW OVER WRN KS/NEB SHOULD CONTINUE RAPIDLY ESE TODAY...REACHING A DSM/SZL/FYV/MLC LINE BY 00Z WEDNESDAY. AT THE SAME TIME...EXPECT THAT BACK-DOOR TYPE FRONT NOW SETTLING S/SW ACROSS THE OZARKS AND TN VLY WILL BECOME STATIONARY LATER THIS MORNING. SURFACE HEATING AND CONTINUED ELY MOTION OF NRN PLNS TROUGH SHOULD ALLOW BOUNDARY TO MOVE OR MIX NEWD INTO E CNTRL MO/WRN KY AND MIDDLE TN BY LATE AFTERNOON/EARLY EVENING. FARTHER SE...RIDGING OFF THE S ATLANTIC CST EXPECTED TO DRIVE SRN PORTION OF SAME FRONT FARTHER SW ACROSS PARTS OF AL/GA AND FL. ...LWR MO VLY INTO MID MS VLY/LWR TN VLY AND OZARKS... CURRENT DATA SHOW LIGHT ELY SURFACE WINDS CONTINUING TO ADVECT RELATIVELY DRY/COOL AIR FROM GRT LKS RIDGE INTO MO. BUT PROFILER AND VWP WINDS SHOW THAT THE FLOW IS SHALLOW /LESS THAN 1 KM DEEP/. THUS...WITH DAYTIME HEATING...WEAK FRONT NOW STALLED OVER NRN AR SHOULD REDEVELOP NEWD...AND ALLOW SLIGHTLY ELEVATED MOIST LAYER TO MIX TO THE SURFACE. COMBINATION OF LOW LEVEL MOISTURE INFLOW /WITH DEWPOINTS RANGING FROM THE UPR 50S IN NW MO TO PERHAPS THE MID 60S IN S CNTRL AND SERN PARTS OF THE STATE/...SURFACE HEATING AND STEEP MID LEVEL LAPSE RATES SHOULD BOOST AFTERNOON SBCAPE TO AOA 2500 J/KG FROM THE SZL/COU AREA S/SE INTO NRN AR AND FAR W KY AND W TN. STOUT EML CAP LIKELY WILL PROHIBIT SURFACE-BASED STORM DEVELOPMENT IN WARM SECTOR THROUGH MOST OF THE DAY. STORMS WILL...HOWEVER... LIKELY DEVELOP SEWD FROM ERN NEB/FAR WRN IA BY EARLY AFTERNOON AS FORCED ASCENT NEAR POINT OF OCCLUSION BETWEEN EWD-MOVING COLD FRONT AND STATIONARY/WARM FRONT BREACHES CAP. THIS ACTIVITY SHOULD BUILD S/SE INTO NW MO BY MID AFTERNOON AND PRODUCE SEVERE HAIL. FARTHER E/SE...HEATING AND PERSISTENT WARM ADVECTION MAY INITIATE ADDITIONAL STORMS BY LATE IN THE DAY SEWD ALONG WARM/STATIONARY FRONT INTO CNTRL/ERN MO. A RELATIVE WEAKNESS IN THE 700-500 MB FLOW WILL EXIST OVER CNTRL MO TODAY...BETWEEN STRONGER BELTS OF FLOW AIMED TOWARD THE UPR MS VLY AND TN. BUT EVEN WITH MODEST /30 KT/ FLOW IN THAT LAYER...IT APPEARS THAT DEEP SPEED AND DIRECTIONAL SHEAR SHOULD NEVERTHELESS BE ADEQUATE FOR SUSTAINED SUPERCELLS. GIVEN DEGREE OF EXPECTED INSTABILITY...QUALITY OF MOISTURE RETURN AND LIKELIHOOD FOR STRONG HEATING...POTENTIAL WILL THEREFORE EXIST FOR VERY LARGE HAIL AND TORNADOES. THE GREATEST RISK SHOULD FOCUS FROM POINT OF OCCLUSION IN CNTRL MO SEWD ALONG WARM/STATIONARY FRONT. SOMEWHAT LATER TONIGHT...MORE ISOLATED SUPERCELLS MAY DEVELOP SWD ALONG COLD FRONT INTO NRN/WRN AR. W/E BREADTH OF WARM SECTOR AND CONTINUED LOW LEVEL WARM ADVECTION/ MOISTURE INFLOW SUGGEST THAT STORMS WILL CONTINUE TO MOVE/DEVELOP ESE ACROSS THE MID MS/LWR OH AND LWR TN VLYS THROUGH EARLY WEDNESDAY. THE ACTIVITY IN WRN KY AND IN WRN/MIDDLE TN SHOULD REMAIN SURFACE-BASED AND QUASI-DISCRETE. THESE LIKELY WILL POSE A THREAT FOR HAIL AND POSSIBLY AN ISOLATED TORNADO. FARTHER N...A BAND OR TWO OF ELEVATED STORMS COULD PRODUCE MARGINALLY SEVERE HAIL EWD INTO IL/IND AND CNTRL KY. ...SW GA/AL INTO MIDDLE TN TODAY... STRONG SURFACE HEATING WILL OCCUR AHEAD OF SHALLOW FRONT BACK-DOORING WSW INTO AL TODAY. COUPLED WITH RICH MOISTURE AVAILABILITY...FAIRLY STEEP MID LEVEL LAPSE RATES AND 30-40 KT NWLY MID LEVEL FLOW...SETUP COULD SUPPORT DEVELOPMENT OF SCATTERED STRONG TO SEVERE STORMS WITH WIND/HAIL INTO EARLY EVENING. ...ERN TN/ERN KY/WRN NC EARLY WEDNESDAY... ELEVATED STORMS WITH MARGINALLY SEVERE HAIL MAY AFFECT THE CUMBERLAND PLATEAU AND PARTS OF THE SRN APPALACHIANS AFTER 06-09Z WEDNESDAY AS WLY LLJ/ELEVATED MOISTURE INFLOW STRENGTHEN OVER REGION. ..CORFIDI/JEWELL.. 04/18/2006  From SwoDy1 at goshenarc.org Tue Apr 18 16:30:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 12:30:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 181622 SWODY1 SPC AC 181620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CDT TUE APR 18 2006 VALID 181630Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF MO... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO RIVER VALLEY INTO CENTRAL TX AND ERN AL/WRN GA.... ...MID MO RIVER VALLEY INTO THE LOWER OH RIVER VALLEY... SURFACE LOW WAS LOCATED OVER NEB NEAR BIE AT 16Z WITH SEWD EXTENDING WARM FRONT STILL TAKING SHAPE ALONG THE LOWER MO RIVER VALLEY. COLD FRONT TRAILING THE LOW CENTER WAS ADVANCING QUICKLY SEWD ACROSS CENTRAL KS/NWRN OK...AND WILL CONTINUE INTO THE OZARKS/WRN MO BY THE LATE AFTERNOON. MODELS ARE FAIRLY CONSISTENT WITH SURFACE FEATURES TODAY...DEVELOPING A LOW CENTER SEWD ALONG THE TRIPLE POINT INTO NWRN/CENTRAL MO BY 00Z AND INTO FAR WRN KY BY THE END OF THE PERIOD. LOW LEVEL MOISTURE FIELDS ARE MUCH HIGHER TODAY THAN WITH THE PAST SEVERAL SYSTEMS /I.E. H85 DEW POINTS AOA 10C AND SURFACE DEW POINTS IN THE MID 60S F OVER ERN OK/AR /. EXPECT MID/UPPER 60F SURFACE DEW POINTS WILL SURVIVE MIXING WITH AN AXIS EXTENDING INTO NWRN/CENTRAL MO BY THE LATE AFTERNOON. UNLIKE THE PREVIOUS SEVERE WEATHER EVENTS OVER THE PAST FEW WEEKS...LARGE SCALE ASCENT WILL NOT BECOME MAXIMIZED INTO THE WARM SECTOR TODAY AS OF NOSE STRONG MID/UPPER LEVEL JET LAGS WWD BEHIND THE SURFACE COLD FRONT. HOWEVER...VERY STEEP LAPSE RATES AND UNSEASONABLY WARM/MOIST BOUNDARY LAYER WILL SUPPORT A STRONGLY UNSTABLE WARM SECTOR BY THE MID AFTERNOON. IN ADDITION...SURFACE CONVERGENCE WILL BECOME MAXIMIZED INTO THE LOWER MO RIVER VALLEY AS TRIPLE POINT DEVELOPS SEWD. GIVEN THE MORE LIMITED LARGE SCALE ASCENT TODAY...EXPECT HEATING AND CONVERGENCE WILL BE NEEDED TO BREAK STRONG CAP WITH THUNDERSTORM DEVELOPMENT POSSIBLY DELAYED UNTIL LATE IN THE DAY. EXCEPTION WILL BE INTO IA WHERE STRONGER FORCING WILL OVERSPREAD MARGINAL...ELEVATED INSTABILITY NORTH OF THE WARM FRONT TODAY. HERE...THUNDERSTORMS SHOULD INCREASE AND SPREAD A THREAT OF LARGE HAIL NNEWD INTO THE EVENING. MODELS ARE MOST CONSISTENT WITH DEVELOPING PRIMARY SEVERE THREAT BETWEEN 21Z-00Z NEAR THE LOW CENTER OVER NWRN MO AND ALONG COLD FRONT INTO PORTIONS OF SWRN/S-CENTRAL MO. ACTIVITY WILL INCREASE IN SEVERITY AND COVERAGE AS STRONGEST ASCENT FINALLY CATCHES UP WITH THE WARM SECTOR INTO THE MID MS/LOWER OH RIVER VALLEYS THROUGH THE EVENING. DEEP LAYER SHEAR IS NOT FORECAST TO BE OVERLY IMPRESSIVE /35-45 KT OF SFC-6 KM SHEAR/ THOUGH WILL STILL BE ADEQUATE FOR SUPERCELLS GIVEN AMOUNT OF INSTABILITY AND STRONG PRESSURE FALLS AHEAD OF APPROACHING UPPER LOW/WARM FRONT. BACKED SURFACE WINDS SHOULD SUPPORT 0-1 KM SRH IN EXCESS OF 150 M2/S2 WITH AN INCREASED THREAT OF TORNADOES THROUGH THE EVENING OVER CENTRAL AND SERN MO. EXPECT DEVELOPMENT WILL BUILD/ORGANIZE INTO A MCS WHICH MAY CONSOLIDATE SUFFICIENTLY INTO A BOW ECHO/QUASI-LINEAR SYSTEM RACING SEWD ALONG THE WARM FRONT INTO THE MID SOUTH/LOWER OH RIVER VALLEY AFTER DARK. WIND DAMAGE MIGHT BECOME PREVALENT WITH THIS ACTIVITY...THOUGH A TORNADO THREAT WILL ALSO REMAIN AS STRONG PRESSURE FALLS PRECEDE THIS ACTIVITY. MCS MAY CONTINUE ESEWD ACROSS THE TN VALLEY LATER TODAY. ...FAR ERN OK/AR INTO CENTRAL TX... THUNDERSTORM DEVELOPMENT WILL BE MORE ISOLATED ALONG THE COLD FRONT GIVEN STRENGTH OF CAPPING TODAY. HOWEVER...AIR MASS WILL BECOME MODERATELY UNSTABLE AND REMAIN UNDER MODEST WLY MID LEVEL FLOW FOR 35-45 KT OF EFFECTIVE BULK-SHEAR. CINH WILL WEAKEN LATER THIS AFTERNOON AS HIGH TEMPERATURES REACH WELL INTO 90S F. THUS...CONVERGENCE ALONG COLD FRONT AND AMOUNT OF SHEAR WILL BE CAPABLE OF SUPPORTING ISOLATED SEVERE THUNDERSTORMS INTO THE EARLY/MID EVENING FROM CENTRAL TX INTO WRN/CENTRAL AR. ...TN RIVER VALLEY INTO SERN AL/SWRN GA... SURFACE FRONT WILL STALL IN A NNW-SSE ORIENTATION FROM THE ERN FL PANHANDLE INTO MIDDLE TN. STRONG AFTERNOON HEATING AND PRESENCE OF UPPER 60F SURFACE DEW POINTS SHOULD SUPPORT A VERY UNSTABLE AIR MASS WEST OF THIS FRONT. IN ADDITION...NWLY FLOW ALOFT WILL REMAIN SUFFICIENT FOR 30-40 KT OF DEEP LAYER SHEAR PARALLELING THE STALLED SURFACE FRONT. REGION WILL REMAIN UNDER/AHEAD OF SHORTWAVE RIDGING ALOFT AND LIMIT THUNDERSTORM POTENTIAL/COVERAGE ALONG THE FRONT. HOWEVER...FORECAST SOUNDINGS REMAIN MORE THAN SUFFICIENT FOR ORGANIZED MULTICELLS AND ISOLATED SUPERCELLS SHOULD HEATING/CONVERGENCE INITIATE STORMS. ANY SEVERE THREAT EXPECTED TO BE DIURNALLY-DRIVEN AND DIMINISH BY THE MID EVENING. ..EVANS/CROSBIE.. 04/18/2006  From SwoDy1 at goshenarc.org Wed Apr 19 01:05:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 18 Apr 2006 21:05:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190102 SWODY1 SPC AC 190101 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0801 PM CDT TUE APR 18 2006 VALID 190100Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL/SRN MO THRU EXTREME SRN IL...WRN KY AND WRN TN...AND NE AR... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA...FROM THE MID MS VLY INTO THE ERN GULF STATES...AND ACROSS PARTS OF THE SRN PLAINS... ...LOWER MO VALLEY INTO PARTS OF LOWER OH/TN VALLEYS... MID/UPPER LEVEL TROUGH IS EXPECTED TO INTENSIFY FAIRLY RAPIDLY /UP TO 80 METERS/12 HOUR HEIGHT FALLS WITHIN CENTER OF CIRCULATION/ OVERNIGHT AS IT EVOLVES INTO A DEEP CLOSED LOW OVER CENTRAL SD BY 12Z WEDNESDAY. EARLY EVENING SURFACE ANALYSIS SHOWED A COLD FRONT ADVANCING EWD THROUGH WRN MO AND ERN OK...WITH OCCLUSION POINT OF THE COLD FRONT/ WARM FRONT OVER NWRN MO. THE WARM FRONT STRETCHED SEWD TO SERN MO AND THEN INTO MIDDLE TN...WHERE IT BECOMES QUASI-STATIONARY EXTENDING S/SEWD INTO NWRN-SRN FL. MEANWHILE... AN OCCLUDED FRONT EXTENDED NNWWD FROM NWRN MO ACROSS WRN IA TO THE OCCLUDED SURFACE LOW OVER SOUTH CENTRAL ND. SUPERCELLS DEVELOPED DURING THE LATE AFTERNOON AT THE OCCLUSION POINT OVER NWRN MO. ALTHOUGH HEIGHT FALLS SHOULD NOT BE TOO STRONG S OF MID-LEVEL JET AXIS...FORCING WITH PROGRESSIVE COLD FRONT AND MODERATELY UNSTABLE AIR MASS WILL SUPPORT ADDITIONAL STORMS ACROSS MO/AR INTO LOWER OH/TN VALLEYS AS OCCLUSION POINT TRACKS TOWARD THE SSE REACHING WRN KY BY 12Z. STRONG DEEP LAYER SHEAR FAVORS ADDITIONAL SUPERCELLS...WITH THREAT FOR TORNADOES GREATEST IN VICINITY OF OCCLUDED POINT AND ALONG WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE ENHANCED BY BACKED LOW-LEVEL WINDS. STRENGTHENING/VEERING LLJ FROM AR INTO LOWER OH VALLEY SHOULD ALSO SUPPORT LARGER HODOGRAPHS FOR CONTINUED TORNADO POTENTIAL REACHING WRN KY/WRN TN LATER TONIGHT/EARLY WEDNESDAY MORNING. THIS LATTER SEVERE THREAT IS EXPECTED TO BE ALONG THE SRN PERIPHERY OF AN EWD MOVING MCS SPREADING INTO THE LOWER OH AND TN VALLEYS...WHERE AVAILABLE INSTABILITY WILL REMAIN THE GREATEST. LARGE HAIL/DAMAGING WINDS WILL CONTINUE TO BE A THREAT AS WELL GIVEN FAVORABLE THERMODYNAMICS...WITH HAIL BEING THE PRIMARY THREATS NE OF WARM FRONT INTO MUCH OF IL TO SRN IND WHERE ACTIVITY WILL BE ELEVATED. ...TX... ONGOING CLUSTER OF STRONG/SEVERE STORMS ACROSS CENTRAL TX TO THE NW AND N OF SAT-AUS IS BEING AIDED BY LARGE SCALE ASCENT WITH WEAK MID-LEVEL IMPULSE MOVING NEWD ACROSS REGION. GIVEN THAT STORM INITIATION WAS ALSO TIED TO STRONG SURFACE HEATING WITHIN DEEPLY MIXED ENVIRONMENT...LOSS OF INSOLATION SHOULD ALLOW FOR EVENTUAL DECREASE IN NEW ACTIVITY LATER THIS EVENING. UNTIL THEN...LARGE HAIL AND DAMAGING WINDS WILL REMAIN POSSIBLE. ...UPPER MS VALLEY... STRONG HEIGHT FALLS AHEAD OF THIS UPPER FEATURE WILL DEVELOP/ SPREAD ACROSS THE UPPER MS VALLEY AND IA TO NRN IL. THIS COMBINED WITH STRONG LOW-LEVEL WAA SHOULD MAINTAIN PRIMARILY ELEVATED THUNDERSTORMS ALONG/E OF OCCLUDED FRONT...WHERE WEAK INSTABILITY AND EFFECTIVE DEEP LAYER SHEAR SHOULD SUPPORT GENERALLY MARGINALLY SEVERE HAIL. HIGHER INSTABILITY VALUES...BUT STILL ELEVATED...SWD INTO IA/IL MAY ALLOW FOR LOCALLY LARGER HAIL WITH THE STRONGEST ACTIVITY. ...ERN AL/WRN-SWRN GA TO NRN FL... ALTHOUGH DEEP LAYER SHEAR REMAINS SUPPORTIVE OF ORGANIZED STORMS...A CONTINUED DIMINISHING TREND IN SEVERE STORM POTENTIAL IS EXPECTED WITH THE LOSS OF DAYTIME HEATING STABILIZING THE AIR MASS. UNTIL ABOUT 03Z...A FEW STRONGER STORMS WILL BE CAPABLE OF PRODUCING ISOLATED HAIL/STRONG WIND GUSTS. ..PETERS.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 06:13:14 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 02:13:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190607 SWODY1 SPC AC 190605 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0105 AM CDT WED APR 19 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TX HILL COUNTRY/EDWARDS PLATEAU EWD TO THE UPPER TN VALLEY/SERN STATES... ...SYNOPSIS... LARGE CUT-OFF MID/UPPER LEVEL LOW INITIALLY LOCATED OVER THE NRN PLAINS WILL WEAKEN SLIGHTLY TODAY AS OMEGA BLOCK SHIFTS SLIGHTLY EWD. BY THE END OF THE PERIOD...MODELS CONTINUE TO INDICATE LARGE SCALE PATTERN EVOLVING INTO MORE OF A REX BLOCK FROM THE NRN PLAINS/UPPER MS VALLEY CLOSED LOW NNEWD INTO HUDSON BAY REGION. MEANWHILE...WATER VAPOR IMAGERY INDICATED A SERIES OF MAINLY WEAK MID-LEVEL IMPULSES TRAVERSING SRN STREAM FLOW FROM SRN BAJA/NRN MEXICO ENEWD TO THE LOWER MS VALLEY...AND THEN TURNING E/SELY ACROSS MS/AL INTO SERN STATES. FARTHER W...A SHORT WAVE TROUGH CURRENTLY MOVING INTO SRN CA WILL MOVE EWD REACHING AZ/NM BY 12Z THURSDAY. IN THE LOW-LEVELS...SURFACE LOW IS EXPECTED SLOWLY FILL AS IT MOVES EWD ACROSS KY THIS FORECAST PERIOD. COLD FRONTAL SURGE IS EXPECTED TO SLOW TODAY AS THIS BOUNDARY BECOMES ORIENTED PARALLEL TO THE SRN BRANCH OF THE WESTERLIES. ...OH/TN VALLEYS INTO THE SERN STATES... CLUSTER OF THUNDERSTORMS/MCS IS EXPECTED TO BE ONGOING AT START OF PERIOD ACROSS PARTS OF LOWER OH/UPPER TN VALLEYS AND SRN APPALACHIANS. WAA REGIME PER WLY LLJ VEERING TO WNWLY ACROSS THE SERN STATES IS EXPECTED TO SUPPORT DOWNSTREAM DESTABILIZATION TO MAINTAIN THIS ACTIVITY ACROSS WRN NC/SC/GA THIS MORNING AND AFTERNOON...WITH ATTENDANT THREATS OF DAMAGING WINDS AND HAIL. POTENTIAL OUTFLOW BOUNDARY FROM THIS COMPLEX AND/OR ZONE OF DIFFERENTIAL HEATING EXPECTED ACROSS GA ALONG WRN PERIPHERY OF CLOUD SHIELD SHOULD RE-ENFORCE RESIDUAL BOUNDARY DRAPED SEWD ACROSS THIS AREA INTO FL. SURFACE HEATING EXPECTED IN THE WAKE OF THIS INITIAL ACTIVITY COMBINED WITH SURFACE DEWPOINTS IN THE MID 60S AND STEEP MID-LEVEL LAPSE RATES SHOULD RESULT IN MUCAPES OF 2000-3000 J/KG EXTENDING FROM THE SURFACE LOW INTO ERN AL/GA. LARGE SCALE ASCENT WITH A MID-LEVEL IMPULSE...CURRENTLY MOVING THROUGH THE ARKLATEX REGION...IS EXPECTED TO TRANSLATE SEWD ACROSS ERN GULF COAST STATES AIDING IN THUNDERSTORM DEVELOPMENT ALONG THE SE-NW ORIENTED SURFACE BOUNDARY THIS AFTERNOON. STRONG DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS/SUPERCELLS WITH ATTENDANT THREAT OF HAIL/ DAMAGING WINDS AND PERHAPS A COUPLE OF TORNADOES. ...TX HILL COUNTRY/EDWARDS PLATEAU TO NERN TX/LOWER MS VALLEY... 40 KT OF SWLY MID-LEVEL FLOW IS EXPECTED TO EXTEND FROM SWRN TX AND THE TX HILL COUNTRY TO AR/LOWER TN VALLEY. BY EARLY AFTERNOON...COLD FRONT SHOULD EXTEND FROM MIDDLE TN/NRN MS WSWWD INTO NERN TX AND THEN TO THE RIO GRANDE VALLEY NEAR DRT. MODERATE INSTABILITY IS EXPECTED ALONG/S OF THIS BOUNDARY...GIVEN STRONG SURFACE HEATING WITHIN A MOIST AIR MASS AND BENEATH STEEP MID-LEVEL LAPSE RATES. MUCH OF THE STRONGER FLOW ALOFT IS PROGGED TO BE OVER THE POST-FRONTAL AIR MASS RESULTING IN RATHER WEAK DEEP LAYER SHEAR ACROSS PARTS OF THE LOWER MS VALLEY THIS AFTERNOON...LIMITING STORM ORGANIZATION. AN EXCEPTION SHOULD BE FARTHER SW ACROSS THE TX HILL COUNTRY WHERE THE STRONG FLOW ALOFT WILL SUPPORT FAVORABLE DEEP LAYER SHEAR FOR ORGANIZED STORMS. ANY STORMS THAT DEVELOP OVER THIS REGION WILL BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE N/NEWD FROM THE TX HILL COUNTRY INTO PARTS OF CENTRAL TO NERN TX AND PERHAPS INTO SRN AR/NRN LA AS ISENTROPIC ASCENT INCREASES N OF SURFACE BOUNDARY LATER THIS EVENING/TONIGHT. STRENGTHENING SWLY MID-LEVEL WINDS AHEAD OF SWRN STATES SHORT WAVE TROUGH ARE EXPECTED TO RESULT IN SUFFICIENT EFFECTIVE DEEP LAYER SHEAR FOR SOME STORM ORGANIZATION GIVEN MODERATE INSTABILITY. HAIL WOULD BE THE PRIMARY THREAT WITH THE OVERNIGHT ACTIVITY. ..PETERS/JEWELL.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 13:01:52 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 09:01:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191258 SWODY1 SPC AC 191256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED APR 19 2006 VALID 191300Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM S CNTRL TX THROUGH THE LWR MS VLY TO SRN APLCNS... ...SYNOPSIS... OMEGA BLOCK WILL PROGRESS SLOWLY E ACROSS THE CNTRL/ERN U.S. THIS PERIOD AS SRN CA UPR VORT CONTINUES E TOWARD THE FOUR CORNERS. AT THE SURFACE...COLD FRONT ASSOCIATED WITH NRN PLNS LOW EXPECTED TO BECOME MORE OR LESS STATIONARY FROM S CNTRL TX E/NE ACROSS SRN AR INTO THE UPR TN VLY. A BIT FARTHER S AND E...WEAK BACK-DOOR BOUNDARY THAT MOVED INTO AL YESTERDAY SHOULD RETREAT E ACROSS GA TODAY IN RESPONSE TO WLY LLJ AND SURFACE WAVE MOVING E ACROSS TN. ...UPR TN VLY INTO GA/WRN CAROLINAS... RESIDUAL WLY LLJ WILL IMPINGE UPON RETREATING BACK-DOOR FRONT OVER THE SRN APPALACHIAN REGION TODAY. LARGE SCALE FORCING FOR ASCENT WILL BE WEAK OVER THE AREA AS HEIGHTS SLIGHTLY REBOUND WITH THE CONTINUED PROGRESSION OF AFOREMENTIONED OMEGA PATTERN. BUT COMBINATION OF SURFACE HEATING...UPSLOPE COMPONENTS AND CONVERGENCE ALONG FRONT AN/OR OUTFLOW FROM OVERNIGHT CONVECTION LIKELY TO RESULT IN RENEWED AND/OR STRENGTHENED STORM DEVELOPMENT OVER PARTS OF SE TN/NRN AL/GA AND THE WRN CAROLINAS BY MIDDAY. HEATING BENEATH RESIDUAL EML SHOULD YIELD SBCAPE AOA 2000 J/KG W OF BACK-DOOR FRONT IN SRN TN/AL AND WRN GA...WITH VALUES DECREASING TO AROUND 1000 J/KG IN THE WRN CAROLINAS. COUPLED WITH DEEP NWLY SHEAR OF 35-40 KTS ORIENTED ROUGHLY PARALLEL BACK-DOOR BOUNDARY...SETUP MAY SUPPORT A FEW SUPERCELLS WITH HAIL AND POSSIBLY A COUPLE TORNADOES IN GA AND THE WRN CAROLINAS. FARTHER W...DEEP SHEAR LIKELY WILL BE ORIENTED MORE PERPENDICULAR TO COMPOSITE STORM OUTFLOW BOUNDARY IN TN. COUPLED WITH STEEP LOW TO MID LEVEL LAPSE RATES /PER BHM 12Z RAOB/...POSSIBILITY WILL BE GREATER FOR A FORWARD-PROPAGATING MCS/SQUALL LINE. EMBEDDED BOWS MAY YIELD BOTH HIGH WIND AND HAIL. ALL OF THE STORMS IN THIS REGION SHOULD BE STRONGLY DIURNAL...WITH LITTLE IF ANY SEVERE THREAT CONTINUING INTO THE NIGHT. ...S CNTRL TX INTO THE ARKLATEX AND THE LWR MS VLY... STALLING COLD FRONT WILL BE FOCUS OF TSTM DEVELOPMENT LATE TODAY INTO TONIGHT FROM S CNTRL TX NEWD INTO THE ARKLATEX AND THE LWR MS VLY. BY EARLY AFTERNOON...FRONT SHOULD EXTEND FROM MIDDLE TN/NRN MS WSWWD INTO NERN TX AND THEN TO THE RIO GRANDE NEAR DRT. MODERATE INSTABILITY /SBCAPE 0F 1500-2000 J PER KG/ WILL DEVELOP ALONG/S OF THE BOUNDARY GIVEN STRONG HEATING...MOIST PREFRONTAL AIR MASS AND STEEP MID-LEVEL LAPSE RATES. 30-40 KT SWLY MID-LEVEL FLOW ROUGHLY PARALLEL TO FRONT WILL EXTEND FROM S CNTRL TX INTO AR AND THE LWR MS VLY. THE STRONGEST FLOW ALOFT OVER THE TN VLY SHOULD REMAIN IN THE POST-FRONTAL ENVIRONMENT. THIS SHOULD LIMIT DURATION/ORGANIZATION OF ANY STORMS THAT DO FORM OVER THAT REGION IN WAKE OF ON-GOING MORNING STORMS. HOWEVER...GIVEN DEGREE OF AFTERNOON CAPE /AROUND 2000 J PER KG/...A CONDITIONAL THREAT WILL EXIST FOR A FEW SPOTS OF SEVERE HAIL/LOCALLY DAMAGING WIND THROUGH EARLY EVENING. FARTHER SW...SOMEWHAT GREATER DEEP WSWLY SHEAR WILL BE PRESENT INVOF FRONT FROM THE ARKLATEX REGION SW TO THE TX BIG BEND. COMBINATION OF STRONG SURFACE HEATING AND FRONTAL UPLIFT MAY INITIATE MORE ORGANIZED STORMS/SUPERCELLS. GIVEN FAIRLY RICH BOUNDARY LAYER MOISTURE AND STEEP MID LEVEL LAPSE RATES...THIS ACTIVITY WILL BE CAPABLE OF LARGE HAIL AND DAMAGING WIND. STORM COVERAGE EXPECTED TO INCREASE FROM THE TX HILL COUNTRY N/NE INTO PARTS OF CNTRL/NE TX TONIGHT...AND ACROSS SRN AR/NRN LA EARLY THURSDAY...AS ISENTROPIC ASCENT INCREASES N OF STALLED FRONT. STRENGTHENING SWLY MID-LEVEL WIND FIELD AHEAD OF CA SHORTWAVE IMPULSE WILL YIELD SUFFICIENT CLOUD LAYER SHEAR FOR ELEVATED STORMS/POSSIBLE SUPERCELLS WITH HAIL AND HEAVY RAIN. OTHER ELEVATED STORMS/POSSIBLE SUPERCELLS WITH HAIL MAY FORM VERY LATE IN THE PERIOD OVER THE PERMIAN BASIN OF W TX...IN AREA OF RAPID MOISTURE INFLUX/UPR DIVERGENCE AHEAD SAME UPR DISTURBANCE. ...WRN/CNTRL WI... A SMALL AREA WITH THE POTENTIAL FOR NON-SUPERCELL FUNNELS MAY EVOLVE INVOF OLD OCCLUSION MOVING NE ACROSS THE UPR MS VLY THIS AFTERNOON. STEEP LOW LEVEL LAPSE RATE PLUME WILL BE ADJACENT TO BOUNDARY LAYER MOISTURE/VERTICAL VORTICITY AXIS NEAR SURFACE OCCLUSION...AND MAY YIELD A BRIEF SPINUP OR TWO FOLLOWING MAX HEATING. ..CORFIDI/JEWELL.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 16:21:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 12:21:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191617 SWODY1 SPC AC 191616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 AM CDT WED APR 19 2006 VALID 191630Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A BROAD AREA EXTENDING FROM WRN TX INTO THE LOWER MS/TN RIVER VALLEYS AND SOUTHEASTERN U.S.... ...LOWER MS/TN RIVER VALLEYS ACROSS THE SOUTHEAST... WRN REMNANTS OF OVERNIGHT MCS CONTINUE TO INTENSIFY WITHIN FEED OF VERY UNSTABLE AIR AND STEEP LAPSE RATES IN PLACE OVER THE GULF COAST STATES. BROAD WAA-INDUCED THUNDERSTORM AREA ACROSS SC WILL REINFORCE SURFACE OUTFLOW BOUNDARY EXTENDING FROM THE SAV AREA NWWD TO NEAR ATL AND THEN INTO MIDDLE TN. A LOW CENTER IS EXPECTED TO REMAIN NEAR THE TRIPLE POINT OF THIS FEATURE AND SURFACE COLD FRONT SHIFTING SLOWLY SEWD ACROSS MIDDLE TN TODAY. SW OF THE LOW...THE COLD FRONT IS EXPECTED TO STALL AND BECOME STATIONARY ACROSS SRN AR INTO THE BIG BEND REGION OF TX THROUGH THE DAY. IN ADDITION...A WEAK MID LEVEL IMPULSE SUSTAINING THE MCS NOW MOVING ACROSS THE SRN APPALACHIANS WILL CONTINUE SEWD AND MOVE OFF THE SC/GA COAST BY THE EARLY EVENING. STRONG TO OCCASIONALLY SEVERE STORMS...PRIMARILY ELEVATED TO THE NORTH/EAST OF SURFACE OUTFLOW BOUNDARY...EXPECTED TO MAINTAIN MARGINALLY SEVERE HAIL AND PERHAPS ISOLATED DAMAGING WIND ACROSS THE SAVANNA RIVER VALLEY AND MUCH OF SC THROUGH THE DAY. MORE INTENSE STORMS WILL STRADDLE THE OUTFLOW BOUNDARY WHERE NWLY MID LEVEL FLOW AND FEED OF STRONGLY UNSTABLE AIR WILL INCREASE THE SEVERE THREAT FROM NRN/ERN AL INTO CENTRAL/SRN GA THIS AFTERNOON. DEEP LAYER SHEAR WILL BE SUFFICIENT FOR ORGANIZED LINES/SUPERCELLS WITH THESE STORMS...ENHANCING THE THREAT OF VERY LARGE HAIL AND DAMAGING WINDS. ISOLATED TORNADOES MAY ALSO ACCOMPANY STRONGER STORMS...ESPECIALLY NEAR THE NW-SE ORIENTED SURFACE BOUNDARY. THIS ACTIVITY MAY SPREAD INTO NRN FL/SERN GA BEFORE DIMINISHING/MOVING OFFSHORE EARLY THIS EVENING. FARTHER WEST AND NORTHWEST...WEAK MID LEVEL SHORTWAVE TROUGH EVIDENT ON WV IMAGERY MOVING ACROSS THE LOWER MS RIVER VALLEY MAY AGITATE THE WARM SECTOR SUFFICIENTLY FOR INCREASING MOIST CONVECTION THROUGH THE DAY INTO PORTIONS OF NRN MS/WRN AND MIDDLE TN INTO CENTRAL AL. SEVERE POTENTIAL IS A BIT MORE CONDITIONAL ACROSS THIS REGION. THOUGH SHEAR WILL REMAIN MARGINAL ACROSS THIS REGION...ESPECIALLY BELOW 5-6 KM...ANY INTENSE CORES WITHIN VERY STEEP LAPSE RATES AND STRONG INSTABILITY WILL SUSTAIN A THREAT OF LARGE HAIL AND DAMAGING WINDS INTO THE EARLY EVENING. ...ARKLATEX INTO WRN/CENTRAL TX... CONVERGENCE WILL REMAIN FOCUSED ALONG STALLED SURFACE FRONT TODAY FROM THE BIG BEND REGION OF TX INTO THE LOWER MS RIVER VALLEY. THOUGH LARGE SCALE ASCENT WILL REMAIN WEAK/ABSENT...WARM SECTOR WILL BECOME VERY UNSTABLE AND WEAKLY CAPPED DURING THE MID TO LATE AFTERNOON. THEREFORE...EXPECT AT LEAST A FEW CLUSTERS OF INTENSE THUNDERSTORMS WILL FORM ALONG THE BOUNDARY AND PERSIST INTO THE MID EVENING. FORECAST SOUNDINGS MAINTAIN 35-40 KT OF EFFECTIVE SHEAR...SUGGESTING ACTIVITY WILL ORGANIZE INTO MULTICELL LINES/CLUSTERS AND SUPERCELLS. LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED WITH ANY DEVELOPMENT ACROSS THIS REGION LATER TODAY AND THIS EVENING. MOST LIKELY AREA WILL BE INTO THE BIG BEND REGION WHERE TERRAIN WILL AID IN INITIATION...POSSIBLY BY 21Z. VERY LARGE HAIL WILL BE COMMON ACROSS THIS REGION. DEVELOPMENT HERE MAY SPREAD NNEWD ALONG AND NORTH OF THE FRONT SPREADING THREATS OF LARGE HAIL AND ISOLATED DAMAGING WIND INTO N-CENTRAL/NERN TX THROUGH THE EVENING. LATER TONIGHT...INCREASING LARGE SCALE ASCENT ATOP STABLE BOUNDARY LAYER NORTH OF STALLED FRONT WILL OVERSPREAD THE PERMIAN BASIN REGION. SREF AND GFS GUIDANCE BOTH EXPECT ELEVATED THUNDERSTORM DEVELOPMENT INTO THIS REGION WHERE FORECAST SOUNDINGS YIELD MODERATE MUCAPE AND SUFFICIENT EFFECTIVE SHEAR FOR ROTATING UPDRAFTS. THUS...LARGE HAIL WOULD ACCOMPANY STORMS IN THIS REGION WITH ACTIVITY POSSIBLY SPREADING TOWARD CENTRAL TX BY DAY BREAK THURSDAY MORNING. ..EVANS\CROSBIE.. 04/19/2006  From SwoDy1 at goshenarc.org Wed Apr 19 19:55:11 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 15:55:11 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191951 SWODY1 SPC AC 191949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0249 PM CDT WED APR 19 2006 VALID 192000Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN AND TONIGHT ACROSS MUCH OF TX THROUGH THE EASTERN GULF STATES.... BLOCK REMAINS ESTABLISHED IN BELT OF FLOW EXTENDING ACROSS THE NORTH CENTRAL U.S. INTO THE WESTERN ATLANTIC. MODELS SUGGEST DEEP CLOSED LOW OFF THE NORTH ATLANTIC COAST WILL MOVE LITTLE THROUGH LATE TONIGHT...BUT HIGH CENTER MAY BEGIN TO WEAKEN OVER EASTERN ONTARIO AS UPSTREAM CLOSED LOW GRADUALLY SHIFTS EAST OF THE DAKOTAS INTO THE UPPER MISSISSIPPI VALLEY. THIS IS EXPECTED MOSTLY IN RESPONSE TO A SIGNIFICANT IMPULSE PIVOTING AROUND ITS SOUTHERN/EASTERN PERIPHERY. AMPLIFYING UPSTREAM TROUGH OVER THE EASTERN PACIFIC WILL REMAIN WELL OFFSHORE...BUT MAY BE RESPONSIBLE FOR FORCING CONTINUED EASTWARD ACCELERATION OF CLOSED LOW/TROUGH ACROSS THE SOUTHERN PLATEAU LATE THIS AFTERNOON AND TONIGHT. THIS IMPULSE APPEARS TO BE PRECEDED BY ANOTHER WEAKER SHORT WAVE TROUGH...WHICH IS PROGGED TO LIFT ACROSS THE TEXAS BIG BEND REGION THROUGH THE ARKLATEX BY 12Z THURSDAY. ...TENNESSEE VALLEY/GULF STATES... A BROAD WEAK SURFACE LOW...ROUGHLY NEAR INTERSECTION OF CONVECTIVE OUTFLOW BOUNDARY AND SLOWLY ADVANCING COLD FRONT...NOW APPEARS CENTERED ACROSS NORTHWEST ALABAMA/SOUTHERN MIDDLE TENNESSEE. THIS FEATURE HAS BECOME FOCUS FOR STRONGEST DESTABILIZATION...WHICH SEEMS LIKELY TO LEAD TO FURTHER VIGOROUS CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON. LATEST OBJECTIVE ANALYSIS SUGGESTS MIXED LAYER CAPE IS NOW IN EXCESS OF 3000 J/KG ALONG/SOUTH OF THE BOUNDARIES...ACROSS MUCH OF NORTHERN MISSISSIPPI/NORTHERN ALABAMA INTO WEST CENTRAL GEORGIA. THIS IS BENEATH 30 TO 40 KT WESTERLY MID-LEVEL FLOW...WHICH IS CONTRIBUTING TO SUFFICIENT SHEAR FOR SUPERCELLS. MID/UPPER FORCING IS UNCERTAIN...BUT CAPPING APPEARS WEAK ENOUGH TO ALLOW FOR CONTINUED RAPID DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON WITH ADDITIONAL HEATING AND PERSISTENT LOW-LEVEL CONVERGENCE. LARGE CONVECTIVE CLUSTER MAY EVENTUALLY EVOLVE...AND DEVELOP EAST SOUTHEASTWARD THROUGH THE EASTERN GULF STATES. THIS WILL BE ACCOMPANIED BY A RISK FOR DAMAGING WINDS AND HAIL...SOME OF WHICH MAY BECOME QUITE LARGE...THROUGH EARLY EVENING. ...TEXAS... LEAD IMPULSE IS ALREADY SUPPORTING VIGOROUS CONVECTIVE DEVELOPMENT SOUTH OF THE TEXAS BIG BEND...AND ACTIVITY MAY EVENTUALLY DEVELOP ALONG SURFACE FRONT SOUTH OF DEL RIO INTO THE SAN ANTONIO AREA ONCE CAP WEAKENS. IF THIS OCCURS...VEERING LOW-LEVEL WIND FIELDS WITH HEIGHT BENEATH MODERATE WEST SOUTHWESTERLY MID/UPPER FLOW WILL BE SUFFICIENT FOR SUPERCELLS IN ENVIRONMENT WITH MIXED LAYER CAPE IN EXCESS OF 2000 J/KG. THIS ACTIVITY MAY DIMINISH DURING THE EVENING AS INHIBITION INCREASES WITH LOSS OF SURFACE HEATING...BUT WARM ADVECTION NORTH OF FRONT IS EXPECTED TO SUPPORT INCREASING THUNDERSTORMS ACROSS CENTRAL INTO NORTHEAST TEXAS. CAPE FOR PARCELS BASED IN MOIST LAYER ABOVE FRONTAL INVERSION IS EXPECTED TO BE MORE THAN SUFFICIENT TO SUPPORT A LARGE HAIL THREAT. ...LWR OH VLY THROUGH UPPER GREAT LAKES... FORCING ALONG WHAT IS LEFT OF OCCLUDED SURFACE FRONT IS ALREADY SUPPORTING AN INCREASE IN THUNDERSTORMS ACROSS PARTS OF CENTRAL/ EASTERN WISCONSIN. ADDITIONAL ACTIVITY APPEARS POSSIBLE LATER THIS AFTER AND EARLY EVENING...SOUTHWARD INTO PARTS OF ILLINOIS AND INDIANA...WHERE SHEAR MAY CONTINUE TO BECOME MORE FAVORABLE FOR UPDRAFT ROTATION. HOWEVER...OVERALL CONVECTIVE POTENTIAL/ SEVERE THREAT SEEMS LIKELY TO REMAIN LIMITED DUE TO LACK OF MORE FAVORABLE DESTABILIZATION. ..KERR.. 04/19/2006  From SwoDy1 at goshenarc.org Thu Apr 20 01:16:33 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 19 Apr 2006 21:16:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200111 SWODY1 SPC AC 200109 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0809 PM CDT WED APR 19 2006 VALID 200100Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX...ARKLATEX...ACROSS THE LOWER MS VALLEY TO NRN FL... ...SYNOPSIS... OCCLUDED DEEP LAYER CYCLONE RESIDES ACROSS THE NRN PLAINS THIS EVENING WITH EXTENSIVE FRONTAL ZONE ARCING FROM WRN LAKE SUPERIOR SWD TO THE LOWER MS VALLEY...AND THEN SWWD ACROSS THE ARKLATEX TO THE BIG BEND. OCCLUDED NRN SEGMENT OF THE FRONT EXTENDS FROM THE GREAT LAKES TO WRN TN. A WARM FRONT EXTENDS SEWD ACROSS THE TN VALLEY AND HAS BEEN STRONGLY REINFORCED BY CONVECTIVE OUTFLOW FROM AN ACTIVE MCS OVER NRN AL. MORE WIDELY SCATTERED TSTMS EXIST ALONG THE SERN EXTENT OF THIS BOUNDARY...NOW MOVING ACROSS SRN GA AND NERN FL. TRAILING PORTION OF THE FRONT....FROM THE ARKLATEX TO THE RIO GRANDE VALLEY...IS EXPECTED TO REMAIN QUASI-STATIONARY THROUGH THE REST OF THIS FORECAST PERIOD BENEATH MODEST SWLY FLOW ALOFT. WEAK PERTURBATIONS EMBEDDED WITHIN THE MID LEVEL FLOW...COUPLED WITH SOME STRENGTHENING OF THE NOCTURNAL LLJ...SHOULD PROMOTE ADDITIONAL STORM DEVELOPMENT ALONG AND NORTH OF THE FRONT...FROM TX TO SRN AR/NRN LA INTO EARLY THURSDAY MORNING. ...NRN MS/AL...SRN GA/FL... INTENSE MCS ACROSS NRN/NERN AL CONTINUES TO DRIFT GENERALLY SWD FUELED BY VERY UNSTABLE AIR MASS TO THE WEST. WHILE SOME WWD PROPAGATION AND ATTEMPTS AT NEW DEVELOPMENT HAVE BEEN NOTED WITHIN THE STRONG INSTABILITY AXIS WWD INTO NERN MS...GENERALLY LIMITED LARGE SCALE FORCING BENEATH MID LEVEL RIDGE MAY BE INHIBITING MORE WIDESPREAD SURFACE-BASED DEVELOPMENT ACROSS THE WARM SECTOR. BULK OF ONGOING ACTIVITY WAS LIKELY BECOMING INCREASINGLY ELEVATED AS STRONG OUTFLOW SPREADS WWD AWAY FROM THE COMPLEX AND DEEP COLD POOL. NONETHELESS...PLUME OF STEEP LAPSE RATES AND FOCUSED FORCING NEAR THE OUTFLOW-REINFORCED WARM FRONT...COMBINED WITH MORE THAN ADEQUATE SHEAR TO MAINTAIN STORM UPDRAFTS...SHOULD RESULT IN AT LEAST A COUPLE MORE HOURS OF SEVERE WEATHER. PRIMARY THREAT FROM ONGOING STORMS WILL BE LARGE HAIL AS ACTIVITY CONTINUES TO TRACK SWD ACROSS ERN AL AND SRN GA. ...TX ENEWD ACROSS SERN OK/NRN LA/SRN AR... WEAK MID LEVEL SHORT WAVE TROUGH AND STRENGTHENING ISENTROPIC LIFT ACROSS THE STATIONARY FRONT OVER TX SHOULD SUPPORT TSTMS INCREASING ALONG AND NORTH OF THE BOUNDARY THROUGH TONIGHT. THIS PROCESS APPEARS TO BE UNDERWAY FROM MAF TO MWL ATTM. ADDITIONAL STORMS...ROOTED CLOSER TO THE SURFACE BOUNDARY...EXIST FROM DIMMIT AND ZAVALA COUNTIES...WHERE A SMALL MCS MAY BE DEVELOPING...NWD ACROSS THE HILL COUNTRY. STRONG INHIBITION ACROSS THE WARM SECTOR AND EAST OF THE ONGOING FRONTAL ACTIVITY MAY INHIBIT ADDITIONAL SURFACE-BASED DEVELOPMENT LATER THIS EVENING. HOWEVER...ONGOING NEAR SURFACE-BASED STORMS WERE CERTAINLY OCCURRING IN AN ENVIRONMENT FAVORABLE FOR INTENSE/SUSTAINED UPDRAFTS AND SOME WIND/ISOLATED TORNADO POTENTIAL WILL EXIST WITH THIS CONVECTION NEAR THE BOUNDARY FOR AT LEAST ANOTHER HOUR OR SO. ELEVATED STORMS NORTH OF THE FRONT WILL POSE A LARGE HAIL THREAT AND EXPECT THIS ACTIVITY TO EXPAND NWD/EWD ACROSS NRN TX AND INTO SRN AR/SRN LA THROUGH DAYBREAK. ..CARBIN.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 06:12:02 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 02:12:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200607 SWODY1 SPC AC 200606 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0106 AM CDT THU APR 20 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX ACROSS THE LOWER MS VALLEY TO SRN KY...TN...WRN GA... ...SYNOPSIS... SPRINGTIME CUTOFF LOW ACROSS THE UPPER MS VALLEY WILL MAKE ONLY SLOW EWD PROGRESS TOWARD THE WRN GREAT LAKES THIS PERIOD AS A LOWER AMPLITUDE AND MORE PROGRESSIVE IMPULSE IN THE SRN BRANCH MOVES EAST FROM AZ/NM TO THE ARKLATEX. DOWNSTREAM FROM THE SRN BRANCH IMPULSE...A MORE SUBTLE AND POTENTIALLY CONVECTIVELY ENHANCED SHORT WAVE DISTURBANCE IS FORECAST TO TRACK EAST FROM THE SRN PLAINS...ACROSS THE LOWER MS VALLEY...AND THEN TO THE CNTRL APPALACHIANS THROUGH LATE TONIGHT. THE TWO SRN STREAM PERTURBATIONS WILL ENHANCE ASCENT ALONG A QUASI-STATIONARY FRONTAL ZONE WHICH WILL REMAIN SITUATED WITHIN A VERY WARM AND MOIST AIRMASS FROM TX TO TN. ...LOWER MS VALLEY/TN VALLEY... ONGOING LARGE MCS FROM NRN TX TO AR WILL MOVE EWD FROM THE ARKLATEX THROUGH THE MORNING SUSTAINED BY WEAK TO MODEST MOISTURE FLUX AND ASCENT OCCURRING ACROSS STALLED DEEP-LAYER FRONTAL ZONE. GUIDANCE APPEARS TO SUGGEST THAT A FRONTAL WAVE COINCIDENT WITH THIS COMPLEX WILL PROPAGATE ENEWD ALONG THE FRONTAL BOUNDARY ACROSS THE LOWER MS VALLEY AND INTO THE TN VALLEY THROUGH THE DAY WITH LARGE SCALE ASCENT ACROSS THESE AREAS ENHANCED BY POSSIBLE MCV. RELATIVELY UNDISTURBED WARM SECTOR AIR MASS SHOULD EXIST EAST OF THE APPROACHING MCS...AND WEST OF RESIDUAL BACK DOOR FRONT/MCS OUTFLOW...FROM MIDDLE TN TO NRN MS. EXPECT MODERATELY UNSTABLE CONDITIONS TO DEVELOP ALONG THE FRONT IN THIS REGION THROUGH THE MORNING GIVEN SUFFICIENT HEATING. FORCING ASSOCIATED WITH THE APPROACHING WAVE SHOULD PROMOTE ADDITIONAL SURFACE-BASED TSTM DEVELOPMENT FROM NRN MS/WRN TN...EWD ACROSS MIDDLE TN AND NRN AL THROUGH THE AFTERNOON. FORECAST SOUNDINGS ACROSS THE REGION APPEAR TO INDICATE WEAK EFFECTIVE SHEAR ACROSS THE WARM SECTOR INITIALLY WHICH MAY RESULT IN GREATER CONCENTRATION OF MULTICELL STORMS WITH SOME HAIL POTENTIAL. HOWEVER...MID LEVEL FLOW AND DEEP SHEAR STRENGTHEN DURING THE AFTERNOON SO STORMS MAY BECOME BETTER ORGANIZED ALONG THE FRONT AND NEAR SURFACE WAVE. THUS... EXPECT ORGANIZED MULTICELLS AND PERHAPS A COUPLE OF SUPERCELLS SPREADING EAST ACROSS THE REGION THROUGH THE AFTERNOON. THIS ACTIVITY WILL BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. TORNADO POTENTIAL MAY ALSO EVOLVE WITH CELLS TRACKING PREFERENTIALLY NEAR THE FRONT...AND ACROSS THE RESIDUAL OUTFLOW BOUNDARY WHERE LOW LEVEL FLOW WILL BE LOCALLY BACKED AND STRONGER SHEAR WILL LIKELY EXIST. ANOTHER FOCUS FOR STORM DEVELOPMENT MAY EXIST FROM SRN GA WWD ACROSS SRN AL AND MS BY LATE AFTERNOON. A SEGMENT OF RESIDUAL FRONT/OUTFLOW MAY MOVE INTO THESE AREAS WHERE DIURNAL HEATING WILL BOOST CAPE BUT REGION MAY REMAIN CAPPED UNTIL LATER IN THE DAY. MODEST MID LEVEL FLOW WILL PROMOTE ORGANIZED STORMS DEVELOPING IN THIS REGIME WITH ATTENDANT THREAT OF HAIL AND WIND. WITH DIURNAL FORCING BEING THE PRIMARY FACTOR IN THE DEVELOPMENT OF THIS ACTIVITY...EXPECT SEVERE POTENTIAL TO GRADUALLY WANE AFTER SUNSET. ...WEST TX TO THE ARKLATEX... FRONTAL ZONE FROM HILL COUNTRY TO ARKLATEX WILL REMAIN WELL DEFINED IN THE WAKE OF OVERNIGHT/MORNING MCS. AIR MASS ALONG AND SOUTH OF THE FRONT IS EXPECTED TO BECOME INCREASINGLY UNSTABLE THROUGH THE DAY WITH 60S DEWPOINTS AND STEEP MID LEVEL LAPSE RATES CONTRIBUTING TO MLCAPE OF 1500-2000 J/KG. HEIGHT FALLS AND LARGE SCALE ASCENT WITH APPROACHING SRN BRANCH SHORT WAVE TROUGH SHOULD INDUCE SURFACE PRESSURE FALLS ACROSS WRN TX WITH WARM SECTOR POSSIBLY EXPANDING NWD AS LOW LEVEL SELY FLOW STRENGTHENS AHEAD OF DEEPENING TRIPLE POINT SURFACE WAVE AND SHARPENING DRYLINE. FORECAST SOUNDINGS ACROSS THE REGION ARE INDICATING 40-45KT EFFECTIVE SHEAR NEAR THE FRONT...AND DEVELOPING EWD ACROSS THE WARM SECTOR INTO THE EVENING. GIVEN EXPECTED FORCING AND INSTABILITY...ENVIRONMENT SHOULD SUPPORT THE DEVELOPMENT OF SUPERCELLS CAPABLE OF PRODUCING LARGE...POSSIBLY SIGNIFICANT... HAIL. ANY DISCRETE STORMS TRACKING NEAR/ALONG THE WSW-ESE ORIENTED FRONTAL BOUNDARY...OR NEAR SURFACE WAVE...COULD ALSO POSE A THREAT FOR TORNADOES WHERE LOW-LEVEL SHEAR AND BOUNDARY LAYER RH WILL BE MAXIMIZED. STORMS MAY UNDERGO UPSCALE ORGANIZATION INTO AN MCS THROUGH THE LATE EVENING AND DAMAGING WIND POTENTIAL MAY INCREASE AS THIS MCS SPREADS EAST TOWARD THE GULF COAST THROUGH EARLY FRIDAY. IT IS POSSIBLE THAT SEVERE WEATHER PROBABILITIES MAY BE INCREASED...AND CATEGORICAL OUTLOOK COULD BE UPGRADED...ACROSS PORTIONS OF TX AS EVOLUTION OF SEVERE WEATHER SCENARIO BECOMES MORE CERTAIN WITH ADDITIONAL SHORT-TERM ANALYSIS AND FORECAST DATA. ..CARBIN/JEWELL.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 12:57:59 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 08:57:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201251 SWODY1 SPC AC 201250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0750 AM CDT THU APR 20 2006 VALID 201300Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN AND SRN TX NE THROUGH THE ARKLATEX INTO THE TN VLY... ...SYNOPSIS... DEEP CLOSED LOW OVER THE UPR MS VLY WILL EDGE ONLY SLOWLY E THIS PERIOD AND WILL DOMINATE THE FLOW FIELD ACROSS MUCH OF THE U.S. FARTHER S...SHORTWAVE TROUGH NOW ALONG THE AZ/NM BORDER EXPECTED TO CONTINUE E AT A SOMEWHAT GREATER CLIP...REACHING E TX/SE OK BY 12Z SATURDAY. DOWNSTREAM FROM THE AZ/NM SYSTEM...A WEAKER CONVECTIVELY-ENHANCED DISTURBANCE NOW APPARENT IN SATELLITE AND RADAR DATA OVER THE ARKLATEX REGION SHOULD CONTINUE ENE INTO THE TN VLY LATER TODAY...BEFORE TURNING MORE NE TOWARD THE CNTRL APPALACHIANS TONIGHT. THE TWO SRN SHORTWAVES WILL ENHANCE ASCENT ALONG QUASI-STATIONARY FRONT FROM S TX INTO THE TN VLY AND...ALONG WITH DIURNAL HEATING ...WILL BE THE PRIME FACTORS MODULATING CONVECTIVE DEVELOPMENT THIS PERIOD. ...SW TX TO THE ARKLATEX... VERY MOIST AIR /DEWPOINTS IN THE MID 60S TO LOWER 70S/ IS IN PLACE ALONG AND S OF STALLED FRONTAL ZONE ORIENTED ROUGHLY NEWD FROM S CNTRL TX. CLOUD DEBRIS FROM OVERNIGHT STORMS AND ADDITIONAL STRATUS DEVELOPMENT LIKELY WILL LIMIT SURFACE HEATING IN WARM SECTOR TO SOME EXTENT. BUT FAIRLY SUBSTANTIAL SURFACE-BASED DESTABILIZATION /MLCAPE TO 2000 J PER KG/ SHOULD NEVERTHELESS OCCUR FROM THE BIG BEND REGION ENE ALONG FRONT INTO CNTRL TX. INCREASING LARGE SCALE ASCENT ASSOCIATED WITH APPROACHING AZ/NM TROUGH...ALREADY RESPONSIBLE FOR RECENT DEVELOPMENT OF ELEVATED STORMS IN W CNTRL TX...SHOULD FURTHER ENHANCE DESTABILIZATION AND SUPPORT SCATTERED AREAS OF STORM DEVELOPMENT BY MID AFTERNOON. 40 KT WSWLY MID LEVEL FLOW DOWNSTREAM FROM TROUGH WILL CONTRIBUTE SUFFICIENT SHEAR FOR SUPERCELLS WITH VERY LARGE HAIL. POTENTIAL WILL ALSO EXIST FOR A FEW STORMS TO MOVE ALONG FRONT AND/OR OUTFLOW BOUNDARY SEGMENTS THAT SHOULD BE FAVORABLY ORIENTED TO ENHANCE LOW LEVEL SRH/TORNADO DEVELOPMENT. COMBINATION OF INCREASING INSTABILITY CONCURRENT WITH DIURNAL HEATING...AND PRESENCE OF FRONT/OUTFLOW BOUNDARIES...SUGGEST THAT SOME OF THE STORMS WILL FAIRLY QUICKLY ORGANIZE INTO BANDS AND/OR CLUSTERS. THESE SYSTEMS SHOULD MOVE/DEVELOP GENERALLY E TOWARD THE TX CSTL PLN LATER TODAY/TONIGHT...WHERE THERE WILL EXIST A THREAT FOR BOWING SEGMENTS WITH HIGH WIND/HAIL AND PERHAPS A COUPLE TORNADOES. FARTHER N...EXPECT INCREASING COVERAGE OF SLIGHTLY ELEVATED STORMS WITH HAIL AND POSSIBLY DAMAGING WIND FROM W CNTRL TX ENE THROUGH THE ARKLATEX LATER TODAY/TONIGHT AS WARM/MOISTURE ADVECTION STRENGTHEN AHEAD OF PROGRESSIVE AZ/NM TROUGH. ...LWR MS/TN VLY TO SRN/CNTRL APLCNS... POCKET OF STRONG SURFACE-BASED INSTABILITY /SBCAPE TO 2500 J PER KG/ LIKELY WILL DEVELOP OVER NRN MS/SRN MIDDLE TN AND NRN/CNTRL AL WITH HEATING TODAY. THIS REGION WILL BE GLANCED BY ENHANCED WSWLY FLOW ASSOCIATED WITH ARKLATEX MCV. WHILE LOW LEVEL WIND FIELD LIKELY WILL REMAIN WEAK...COMBINATION OF STEEP LOW TO MID LEVEL LAPSE RATES AND 40-50 KT WSWLY MID LEVEL FLOW /PER SHV 12Z RAOB/ MAY PROVE FAVORABLE FOR CLUSTERS OF STORMS/POSSIBLE SUPERCELLS WITH VERY LARGE HAIL AND POSSIBLY HIGH WIND. THIS ACTIVITY SHOULD DEVELOP ACROSS NRN MS/SRN MIDDLE TN BY MID TO LATE MORNING...AND MAY TEND TO SPREAD MORE W TO E THAN WAS THE CASE YESTERDAY AS UPPER FLOW HAS BACKED CONSIDERABLY RELATIVE TO WEDNESDAY. FARTHER N...MORE WIDELY SCATTERED PULSE STORMS WITH MARGINALLY SEVERE HAIL MAY OCCUR EPISODICALLY NWD INTO PARTS OF KY AND...ESPECIALLY LATER IN THE PERIOD...NEWD INTO THE CNTRL APPALACHIANS. ..CORFIDI/JEWELL.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 16:16:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 12:16:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201612 SWODY1 SPC AC 201611 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CDT THU APR 20 2006 VALID 201630Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX TO THE SRN APPALACHIANS... ...TN RIVER VALLEY/CENTRAL GULF COAST STATES INTO THE SRN APPALACHIANS... CONVECTION WILL CONTINUE TO BUILD UPSCALE INTO AN MCS INTO MUCH OF MIDDLE TN/CENTRAL KY AND SPREAD ENEWD INTO THE APPALACHIANS THIS AFTERNOON. THIS ACTIVITY WILL INCREASE AHEAD OF SHORTWAVE TROUGH NOW MOVING OVER THE MID SOUTH. INCREASING CONVECTION/CLOUDS WILL HINDER HEATING AND OVERALL DESTABILIZATION OVER MUCH OF THE TN RIVER VALLEY AND POINTS EWD. IN ADDITION...THIS WILL LIMIT NEWD RETURN OF RICHER MOISTURE NOW CONFINED TO REGIONS EAST OF N-E ORIENTED OUTFLOW BOUNDARY FROM YESTERDAYS STORMS. LARGE HAIL WILL BECOME SCATTERED NORTHEAST OF THIS BOUNDARY...THOUGH MUCH OF IT WILL REMAIN MARGINAL IN SEVERITY. IF AREA DESTABILIZES MORE THAN EXPECTED...LARGE HAIL THREAT WOULD INCREASE IN COVERAGE AND SEVERITY. STORMS ROOTING INTO NRN EXTENT OF MODERATE MLCAPE AXIS INTO NRN MS/NRN AL WILL BE MORE LIKELY TO BECOME MORE ORGANIZED AS WLY FLOW ALOFT MAINTAINS 40 KT OF EFFECTIVE SHEAR. DURING THE MID TO LATE AFTERNOON...HEATING AND MIXING OF SWLY FLOW ALOFT WILL ERODE NRN EDGE OF PERSISTENT SURFACE BOUNDARY AND DESTABILIZE AHEAD OF OUTFLOW BOUNDARY NOW SHIFTING SSEWD INTO NRN MS. TAIL END OF SHORTWAVE TROUGH AND CONVERGENCE WILL LIKELY INITIATE MORE VIGOROUS SEVERE THUNDERSTORMS FROM NRN MS ACROSS NRN/CENTRAL AL...POSSIBLY BY 18Z. FORECAST SOUNDINGS AGAIN FAVOR VERY LARGE HAIL AND PERHAPS A FEW PERSISTENT SUPERCELLS/ORGANIZED CLUSTERS. THIS ACTIVITY SHOULD SPREAD GENERALLY EWD INTO THE SRN APPALACHIANS THROUGH THE EVENING...WITH THREATS OF DAMAGING WINDS AND LARGE HAIL. ...TX INTO THE LOWER MS RIVER VALLEY... COMPLEX EVOLUTION ANTICIPATED ACROSS TX TODAY. STRONG UPPER LOW IS NOW MOVING INTO THE SRN HIGH PLAINS...WITH SUBSEQUENT MID/UPPER LEVEL JET OVERSPREADING TX. SURFACE PATTERN IS QUITE MESSY DUE TO EARLIER CONVECTION...THOUGH EXPECT PRIMARY SURFACE WARM FRONT WILL BECOME BETTER DEFINED FROM THE UPPER TX COAST INTO THE HILL COUNTRY DURING THE AFTERNOON. SOUTH OF THIS BOUNDARY RICH GULF MOISTURE REMAINS IN PLACE WITH SURFACE DEW POINTS AROUND 70F. SLY LLJ OBSERVED ON MORNING UPPER AIR ANALYSES WILL REMAIN ANCHORED INTO THE BIG BEND REGION/EDWARDS PLATEAU THROUGH THE DAY AND MAINTAIN ELEVATED STRONG TO SEVERE THUNDERSTORMS INTO WRN AND NWRN TX. ACTIVITY NOW ONGOING IN THE HILL COUNTRY NEAR THE FRONT MAY BECOME INCREASINGLY SURFACE BASED AND PERSIST EWD INTO CENTRAL TX THROUGH THE AFTERNOON. OTHER VIGOROUS DEVELOPMENT IS EXPECTED TO OCCUR NEARER THE DRY LINE AND AHEAD OF STRONG UPPER LOW INTO SWRN/CENTRAL TX LATER TODAY. THIS ACTIVITY WILL BECOME INCREASINGLY WIDESPREAD WITH INITIAL DEVELOPMENT AS SUPERCELLS AND ORGANIZED CLUSTERS. VERY LARGE HAIL AND A FEW TORNADOES SHOULD ACCOMPANY THESE STORMS. SUPERCELLS MAY PERSIST NEAR THE FRONT...THOUGH OVERALL ACTIVITY SHOULD MORPH INTO ONE OR TWO LARGE MCSS AND SPREAD INCREASED SEVERE THREAT EWD TOWARDS THE MIDDLE TX COAST AND ERN TX THROUGH THE EVENING/OVERNIGHT. ..EVANS/CROSBIE.. 04/20/2006  From SwoDy1 at goshenarc.org Thu Apr 20 19:52:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 15:52:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201948 SWODY1 SPC AC 201946 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0246 PM CDT THU APR 20 2006 VALID 202000Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN TX INTO ERN TN... ...TX... A LARGE CLUSTER OF THUNDERSTORMS HAS EVOLVED FROM THE HILL COUNTRY OF CNTRL TX INTO THE TX SOUTH PLAINS NEAR LBB. THIS ACTIVITY IS DRIVEN IN LARGE PART DUE TO LOW LEVEL WARM ADVECTION ATOP ENTRENCHED COOLER LOW LEVEL BOUNDARY LAYER WHERE ENELY SFC WINDS PERSIST. LLJ WILL REMAIN FOCUSED INTO SWRN TX FOR THE NEXT FEW HOURS BEFORE GRADUALLY VEERING INTO CNTRL TX LATER THIS EVENING. IN THE SHORT TERM...CONTINUED HEATING WILL BE REQUIRED OVER NRN MEXICO...EWD ALONG THE WARM FRONT BEFORE MORE ROBUST WARM SECTOR CONVECTION WILL EVOLVE. UPDRAFT CLUSTERS ARE GRADUALLY LOWERING JUST NORTH OF THE WIND SHIFT OVER GILLESPIE COUNTY TX...WITH A NOTABLE EWD PROPAGATION ALIGNED ALONG FRONTAL ORIENTATION. SHEAR PROFILES REMAIN FAVORABLE FOR SUPERCELL DEVELOPMENT AND WITH TIME POTENTIALLY TORNADIC...ALTHOUGH LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT. LATER TONIGHT...CLUSTER MERGERS AND GRADUALLY VEERING WINDS WITH HEIGHT SHOULD ENHANCE FORWARD PROPAGATION COMPONENT AND DAMAGING WINDS MAY BECOME MORE OF AN ISSUE AS MCS EVOLVES AND SPREADS TOWARD THE MIDDLE/UPPER TX COAST. ...SERN AR TO NRN AL... ISOLATED SEVERE THUNDERSTORMS ARE EVOLVING OVER SERN AR...WITH MOVEMENT EXPECTED INTO NWRN MS SHORTLY. THIS ACTIVITY IS DEVELOPING WITHIN A FAIRLY UNSTABLE AIRMASS...SBCAPES ON THE ORDER OF 2000-3000J/KG...WHERE BOUNDARY LAYER INSTABILITY/LAPSE RATES HAVE INCREASED MARKEDLY OVER THE LAST FEW HOURS. SCATTERED SUPERCELLS SHOULD CONTINUE TO DEVELOP AND SPREAD NEWD ACROSS NRN MS INTO NRN AL ALONG OUTFLOW REMNANTS FROM EARLIER CONVECTIVE ACTIVITY. ADDITIONAL STORMS ARE DEVELOPING WELL EAST INTO NRN AL AT THIS TIME...ALONG MOST PROGRESSIVE PORTION OF WIND SHIFT. THIS BOUNDARY SHOULD ENHANCE THE SUPERCELL THREAT WHILE STEEP LAPSE RATE ENVIRONMENT/CAPE WILL CONTRIBUTE TO THE POTENTIAL FOR VERY LARGE HAIL. UPSTREAM CONVECTION THAT DEVELOPS ACROSS THE ARKLATEX REGION THIS EVENING MAY SPREAD EAST OF THE MS RIVER INTO NRN MS/WRN TN TOWARD THE END OF THE PERIOD...HOWEVER MORE SIGNIFICANT CONVECTION SHOULD OCCUR WITH THE MORE DIURNALLY DRIVEN STORMS THIS AFTERNOON INTO EARLY EVENING. ..DARROW.. 04/20/2006  From SwoDy1 at goshenarc.org Fri Apr 21 01:13:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 20 Apr 2006 21:13:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210109 SWODY1 SPC AC 210107 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0807 PM CDT THU APR 20 2006 VALID 210100Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WEST TX ACROSS THE ARKLATEX TO THE TN VALLEY AND NRN GA... ...SYNOPSIS... QUASI-STATIONARY FRONT WAS SITUATED FROM WEST TX TO THE TN VALLEY THIS EVENING WITH SEVERAL AREAS OF ONGOING VIGOROUS CONVECTION BEING FUELED BY MOIST AND UNSTABLE AIR MASS FLOWING NWD INTO THE FRONTAL ZONE. THE FRONT WAS ALIGNED WITH MODEST /40-50KT/ SWLY MID LEVEL FLOW WITH ONGOING STORMS...AND CONTINUING POTENTIAL FOR DEEP CONVECTION...TIED TO THE PASSAGE OF MID/UPPER LEVEL IMPULSES EMBEDDED WITHIN THE SWLY FLOW ALOFT. ONE OF THESE IMPULSES WAS CURRENTLY MOVING EAST FROM SERN NM AND WILL ENHANCE DEEP LAYER ASCENT ACROSS THE FRONT...FROM WEST TX TO THE LOWER MS VALLEY... THROUGH FRIDAY MORNING. A MORE ELONGATED AND LOWER AMPLITUDE IMPULSE...AND ITS ASSOCIATED MID LEVEL WIND MAX...WERE LIFTING NEWD FROM WRN TN TO THE LOWER OH RIVER VALLEY. ...TX TO NWRN MS... COMPLEX MESOSCALE SITUATION EXISTS ACROSS MUCH OF WRN AND CNTRL TX THIS EVENING WITH A NUMBER OF INTENSE SUPERCELLS AND SLOW MOVING LINE SEGMENTS MOVING EAST FROM THE HILL COUNTRY/AUSTIN AREA TO NW OF HOU. BULK OF THIS ACTIVITY ACROSS THE HILL COUNTRY WAS NEAR/ALONG RESIDUAL SYNOPTIC FRONT BUT NORTH OF AN OLD OUTFLOW BOUNDARY THAT WAS AIDING NEW STORM DEVELOPMENT WEST OF SAN ANTONIO. STRONG DEEP-LAYER ASCENT WITH APPROACHING SHORT WAVE TROUGH...AND INCREASING MASS INFLOW...SHOULD PROMOTE CONTINUING UPSCALE DEVELOPMENT. EVOLVING LARGE MCS WILL DEVELOP EAST INTO LA/SRN AR...AND NRN MS...OVER THE NEXT SEVERAL HOURS. INSTABILITY RESIDING ALONG THE FRONT SHOULD CONTINUE TO PROMOTE STOUT UPDRAFTS WHILE MODEST FORCING...STRONG SHEAR...AND STEEP LAPSE RATES CONTRIBUTE TO SEVERE HAIL AND WIND POTENTIAL. BRIEF TORNADO CANNOT BE RULED OUT FOR CELLS NEAR OR CROSSING THE FRONT...ESPECIALLY OVER THE NEXT HOUR OR SO FOR THE CLUSTER OF STORMS MOVING EAST FROM AUSTIN AREA. ELEVATED STORMS NEAR THE VORT CENTER MOVING TOWARD NWRN TX MAY POSE SOME THREAT OF HAIL OR ISOLATED STRONG WIND GUSTS ACROSS NRN TX OVER THE NEXT FEW HOURS. ...AL/GA... LARGE MCS ACROSS NRN GA WAS BECOMING GRADUALLY LESS ORGANIZED GIVEN WIDESPREAD ATMOSPHERIC OVERTURNING AND GRADUALLY DIMINISHING INSTABILITY AND FORCING. HOWEVER...A FEW SEVERE STORMS/SUPERCELLS WITH HAIL AND/OR WIND WILL REMAIN POSSIBLE ON THE FRINGES OF THE LARGE COLD POOL WHERE UNTAPPED INSTABILITY AND WEAK ISENTROPIC LIFT WILL PERSIST FOR A FEW MORE HOURS...GENERALLY FROM WCNTRL GA ACROSS CNTRL AL...AND PERHAPS INTO NERN MS. ..CARBIN.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 04:40:48 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 00:40:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210436 SWODY1 SPC AC 210435 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CDT THU APR 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS VALLEY NWD ACROSS THE TN VALLEY TO THE CNTRL APPALACHIANS... ...SYNOPSIS... HIGH AMPLITUDE FLOW WILL BECOME MORE PROGRESSIVE ACROSS THE WEST AND SOUTH THIS PERIOD WHILE NRN STATES CUT-OFF LOW MAKES ONLY SLOW EWD PROGRESS OVER THE WRN GREAT LAKES REGION. PRIMARY FEATURE EXPECTED TO DRIVE SEVERE THUNDERSTORM POTENTIAL THROUGH TODAY WILL BE THE SRN BRANCH SHORT WAVE TROUGH CURRENTLY MOVING ACROSS TX. THIS MID-LEVEL WAVE IS FORECAST TO TRANSLATE EWD ACROSS THE MS VALLEY THROUGH LATE TODAY WITH STRONGEST 12H HEIGHT FALLS OF 30-60M MOVING OVER THE SOUTHEAST U.S. BY THE END OF THE PERIOD...SATURDAY MORNING. A NUMBER OF WEAK FRONTAL WAVES MAY EXIST ALONG DEEP-LAYER BAROCLINIC ZONE SITUATED FROM THE UPPER TX COAST TO THE TN VALLEY TODAY. BASED ON LATEST TRENDS...AN MCS OR TWO MAY SURVIVE INTO THE MORNING HOURS NEAR THE FRONT. PRIMARY SURFACE LOW/WAVE ASSOCIATED WITH THE SRN BRANCH SHORT WAVE TROUGH SHOULD BE COINCIDENT WITH A LARGE MCS MOVING ACROSS LA/AR/MS AREA DURING THE MORNING. LATEST NAM-ETA AND SREF MEAN FORECASTS INDICATE THAT THIS PRIMARY LOW WILL TRACK NEWD ACROSS THE MS RIVER TO NRN MS DURING THE AFTERNOON...AND THEN INTO NRN AL DURING THE EVENING. TRAILING COLD FRONT WILL MOVE EAST INTO A MOIST AND UNSTABLE AIR MASS FROM THE LOWER MS VALLEY...TO THE WRN FL PNHDL THROUGH EARLY SATURDAY. ...LA/MS ACROSS TN VALLEY... DIURNAL DESTABILIZATION AHEAD OF MCS OUTFLOW/SFC FRONT AND FRONTAL WAVE WILL PROMOTE THUNDERSTORM INTENSIFICATION DURING THE AFTERNOON ACROSS MS. FURTHERMORE...MID LEVEL WIND MAX ROUNDING THE BASE OF MID/UPPER TROUGH WILL ENHANCE DEEP LAYER SHEAR AND STORM ORGANIZATION ACROSS THE WARM SECTOR. WHILE DEEP LAYER S/SWLY FLOW MAY LIMIT HODOGRAPH CURVATURE...POTENTIAL FOR LOCALLY STRONGER LOW LEVEL SHEAR MAY EVOLVE NEAR THE SURFACE LOW WHERE A FEW LONGER-LIVED SUPERCELLS WILL BE POSSIBLE. CONVECTION WILL CONTINUE TO INCREASE IN AREAL COVERAGE AND INTENSITY INTO THE EVENING WITH STORMS IN BANDS OR CLUSTERS PRODUCING HAIL/WIND DAMAGE...AND PERHAPS A COUPLE TORNADOES...FROM NRN/ERN MS TO AL AND MIDDLE TN. ADDITIONAL STORMS...PERHAPS IN THE FORM OF SUPERCELLS OR LINE SEGMENTS WITH ISOLATED DAMAGING WINDS...SHOULD PRECEDE THE COLD FRONT DEVELOPING EAST FROM THE MS DELTA TO THE FL PNHDL THROUGH THE NIGHT. ...FL... SEA BREEZE CONVECTION IN MODERATELY UNSTABLE AIR MASS HAS THE POTENTIAL TO BE A BIT MORE ROBUST TODAY AS WEAK HEIGHT FALLS MOVE TOWARD THE REGION FROM THE WEST. WHILE LARGE SCALE DEEP LAYER SHEAR WILL BE WEAK...ONE OR TWO CELL INTERACTIONS WITHIN SEA BREEZE COLLISION ZONE OVER THE ERN PENINSULA COULD PRODUCE AN ISOLATED HAIL OR WIND EVENT. ..CARBIN/JEWELL.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 13:01:09 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 09:01:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211257 SWODY1 SPC AC 211255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 AM CDT FRI APR 21 2006 VALID 211300Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT ACROSS THE LOWER MS AND TN VALLEYS.... ...LOWER MS AND TN VALLEYS... A SRN STREAM SHORTWAVE TROUGH OVER N TX WILL CONTINUE EWD TODAY ACROSS THE GULF COAST STATES...AROUND THE SRN PERIPHERY OF A CLOSED LOW OVER THE UPPER MS VALLEY. IN ADVANCE OF THE SRN STREAM TROUGH...SMALLER SCALE CONVECTIVELY INDUCED VORTICITY MAXIMA ARE ASSOCIATED WITH CONVECTIVE CLUSTERS OVER NRN MS AND THE UPPER TX COAST. THE STABILIZING EFFECTS OF THESE STORM CLUSTERS WILL TEND TO LIMIT THE SEVERE THREAT TODAY TO THE NW OF THE COMPOSITE OUTFLOW BOUNDARY FROM SE TX ACROSS NRN LA TO NRN MS...WITH THE STRONGER STORMS FOCUSED IN ADVANCE OF THE MCV/S AND ALONG THE REMNANT OUTFLOW BOUNDARIES DURING THE DAY. SURFACE OBSERVATIONS AND MORNING SOUNDINGS SHOW BOUNDARY LAYER DEWPOINTS OF 65-70 F ACROSS LA/MS/AL TO THE S AND E OF THE OUTFLOW BOUNDARIES. DAYTIME HEATING WILL COMBINE WITH THIS LOW-LEVEL MOISTURE AND MID LEVEL LAPSE RATES NEAR 7 C/KM TO SUPPORT MLCAPE VALUES OF 1500-2000 J/KG WITHIN THE WARM SECTOR. VERTICAL SHEAR IN THE WARM SECTOR WILL BE MODULATED INITIALLY BY THE WAVE MOVING NEWD FROM MS TO TN...AS CONFIRMED BY VWP TIME SERIES ACROSS MS. EXPECT THE STRONGER L0W-LEVEL SHEAR AND WAA TO SHIFT NEWD FROM NRN AL TOWARD TN AND N GA THROUGH THE MORNING IN ADVANCE OF THE NRN MS WAVE...THOUGH WEAKENING INSTABILITY WITH NWD EXTENT AND THE EFFECTS OF ONGOING CONVECTION WILL TEND TO LIMIT THE SEVERE THREAT TO THE N OF TN. FARTHER SW...THE BACKING FLOW WITH HEIGHT OVER MS WILL TEND TO RECOVER TO A SOMEWHAT MORE FAVORABLE PROFILE DURING THE DAY...AS THE NRN MS WAVE MOVES AWAY TO THE NE AND THE PRIMARY TROUGH APPROACHES FROM THE W. MODEST VERTICAL SHEAR BENEATH 55 KT SWLY MID LEVEL FLOW WILL SUPPORT BOWING LINE SEGMENTS AND PERHAPS SUPERCELLS AS CONVECTION DEVELOPS ALONG THE SURFACE BOUNDARY FROM CENTRAL LA INTO WRN MS. CONVECTION MAY ALSO EVOLVE FROM THE ONGOING STORMS MOVING ACROSS SE TX. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREATS. ..THOMPSON/JEWELL.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 16:37:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 12:37:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211634 SWODY1 SPC AC 211632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT FRI APR 21 2006 VALID 211630Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS AND TN VALLEYS INTO THE GULF COAST REGION... ...LOWER MS AND TN VALLEY... BROAD UPPER LOW REMAINS OVER THE UPPER MIDWEST TODAY...WITH SERIES OF SHORTWAVE TROUGHS ROTATING EASTWARD FROM TX INTO THE GULF COAST REGION. ONE SUCH FEATURE IS NOW OVER NORTH CENTRAL TX...AND IS ASSOCIATED WITH LARGE MCS ACROSS LA. THESE STORMS HAVE SHOWN SIGNS OF WEAKENING THIS MORNING. HOWEVER...MOIST/UNSTABLE AIR MASS TO THE EAST WILL ALLOW RE-INTENSIFICATION ACROSS PARTS OF LA/MS/AL THIS AFTERNOON AND EVENING. DAYTIME HEATING...DEWPOINTS IN THE MID/UPPER 60S...AND RELATIVELY COOL MID LEVEL TEMPERATURES WILL PROMOTE A RISK OF DAMAGING WINDS AND LARGE HAIL. ACTIVITY MAY SPREAD INTO PARTS OF SOUTHEAST TN AND NORTHERN/WESTERN GA OVERNIGHT BEFORE WEAKENING. ...CA... NEXT LARGE TROUGH IS ROTATING INTO CA TODAY. WATER VAPOR IMAGERY SHOWS MAIN VORT MAX OFFSHORE...WHICH SHOULD MOVE INTO CENTRAL CA THIS AFTERNOON AND EARLY EVENING. MODEL FORECAST SOUNDINGS SUGGEST THAT MODERATE INSTABILITY WILL DEVELOP OVER THE NORTHERN/CENTRAL VALLEY WITH DEWPOINTS IN THE 50S AND MLCAPE VALUES OVER 1000 J/KG. PRESENT INDICATIONS ARE THAT ISOLATED STRONG STORMS CAPABLE OF HAIL WILL BE POSSIBLE. ACTIVITY SHOULD DIMINISH WITHIN A COUPLE HOURS AFTER SUNSET. ...FL... STRONG DAYTIME HEATING IS OCCURRING TODAY OVER THE FL PENINSULA...WHERE A VERY UNSTABLE AIR MASS IS EXPECTED TO DEVELOP BY AFTERNOON. SEA BREEZE CONVERGENCE WILL LIKELY RESULT IN SCATTERED THUNDERSTORMS ALONG THE EAST COAST...WITH THE POTENTIAL OF HAIL/GUSTY WINDS AND BRIEF TORNADOES IN STRONGER CELLS. ..HART/GUYER.. 04/21/2006  From SwoDy1 at goshenarc.org Fri Apr 21 20:09:28 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 16:09:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212005 SWODY1 SPC AC 212003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT FRI APR 21 2006 VALID 212000Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL GULF COAST/TN VALLEY REGION... ...CENTRAL GULF COAST REGION INTO THE TN VALLEY... MODERATE INSTABILITY IS INDICATED ACROSS THE CENTRAL GULF COAST REGION AND INTO TN THIS AFTERNOON...AHEAD OF VIGOROUS MID-LEVEL VORT MAX NOW MOVING NEWD ACROSS SERN LA/MS. WITH RELATIVELY STRONG SWLY MID-LEVEL JET STREAK ON SERN PERIPHERY OF THIS FEATURE...SUFFICIENT SHEAR EXISTS TO SUPPORT A CONTINUED THREAT ORGANIZED/SUPERCELL STORMS. STRONGEST STORMS ATTM EXIST FROM SRN MS NEWD INTO SERN TN...AND THIS CORRIDOR SHOULD REMAIN THE MOST FAVORABLE ZONE FOR LOCALLY-DAMAGING WINDS AND HAIL THROUGH THIS AFTERNOON. THOUGH SEVERE THREAT MAY EXTEND EWD ACROSS GA LATER THIS EVENING...OVERALL THREAT SHOULD DIMINISH SLOWLY AFTER SUNSET. ...FL... MODERATE INSTABILITY BUT WEAK SHEAR IS INDICATED ACROSS THE FL PENINSULA...WHICH WILL CONTINUE TO SUPPORT THE DEVELOPMENT OF ISOLATED VIGOROUS/PULSE-TYPE SEVERE STORMS THIS AFTERNOON. ACCOMPANYING THREAT FOR HAIL/LOCALLY DAMAGING WINDS SHOULD DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING. ...CENTRAL CA... COOLING ALOFT ASSOCIATED WITH APPROACHING UPPER TROUGH WILL CONTINUE TO STEEPEN LAPSE RATES ACROSS CENTRAL CA THROUGH THE PERIOD. THIS COMBINED WITH DAYTIME HEATING AND DEWPOINTS IN THE 50S IN THE CENTRAL VALLEY MAY YIELD INSTABILITY SUFFICIENT FOR A FEW STRONGER STORMS -- POSSIBLY CAPABLE OF PRODUCING ISOLATED/MARGINALLY-SEVERE HAIL. ..GOSS.. 04/21/2006  From SwoDy1 at goshenarc.org Sat Apr 22 01:10:42 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 21 Apr 2006 21:10:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220107 SWODY1 SPC AC 220105 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0805 PM CDT FRI APR 21 2006 VALID 220100Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NERN GULF COAST TO THE SRN APPALACHIANS... ...FL PANHANDLE TO SRN APPALACHIANS... SEVERAL MORE HOURS OF SCATTERED SEVERE THUNDERSTORM EVENTS APPEAR POSSIBLE TONIGHT AS AN ACCELERATING MID LEVEL WAVE...AND ASSOCIATED FRONTAL ZONE...DEVELOP ENEWD INTO MOIST AND MARGINALLY UNSTABLE AIR MASS FROM THE NERN GULF COAST TO THE SRN APPALACHIANS. LARGE MCS PRECEEDING THE UPPER WAVE WAS CURRENTLY MOVING ACROSS NRN AL AND ERN TN WITH SEVERAL INTENSE TSTMS ALONG THE LEADING EDGE OF MORE WIDESPREAD STRATIFORM RAIN REGION. LATEST ATLANTA AREA SOUNDING WAS INDICATING MARGINAL...BUT ADEQUATE...INSTABILITY TO MAINTAIN DEEP CONVECTION WITHIN A STRONGLY SHEARED KINEMATIC ENVIRONMENT FROM ERN AL ACROSS GA AND INTO PARTS OF THE WRN CAROLINAS. EXPECT MARGINALLY SEVERE HAIL AND PERHAPS ISOLATED WIND DAMAGE TO ACCOMPANY SOME OF THE STRONGER STORMS ACROSS THESE AREAS TONIGHT. CLOSER TO THE GULF COAST...TRAILING PORTION PRE-FRONTAL SQUALL LINE OVER SRN AL AND THE WRN FL PNHDL APPEARS TO HAVE OUTRUN STRONGER LARGE SCALE FORCING WITH THE UPPER IMPULSE TO THE WEST. HOWEVER...A COUPLE OF STOUT STORMS PERSIST ALONG THIS FEATURE NEAR MOBILE BAY ATTM. MODEL GUIDANCE CONTINUES TO INDICATE THAT ADDITIONAL STORM FORMATION REMAINS POSSIBLE AS THE SURFACE FRONT AND STRENGTHENING MID LEVEL FLOW MOVE EAST INTO INSTABILITY AXIS LATER TONIGHT. THERMODYNAMIC ENVIRONMENT INDICATED IN BOTH SIL AND TLH RAOBS WOULD APPEAR TO SUPPORT RENEWED CONVECTIVE DEVELOPMENT GIVEN SUFFICIENT FORCING NEAR THE FRONT LATER TONIGHT. THUS...SEVERE WEATHER POTENTIAL MAY INCREASE ACROSS SRN PARTS OF THE SLGT RISK AREA BEFORE THE END OF THIS FORECAST PERIOD. ...NERN FL TO ERN SC... ISOLATED STRONG TO SEVERE STORMS PERSIST FROM ERN FL/SERN GA SEABREEZE NWD TO PRE-FRONTAL CONFLUENCE AXIS OVER NWRN SC. GIVEN APPROACH OF STRONGER LARGE SCALE FORCING FOR ASCENT AND ADEQUATE MOISTURE FLUX INTO THE REGION OF ONGOING ACTIVITY...ISOLATED TO WIDELY SCATTERED DAMAGING WINDS AND/OR HAIL APPEAR POSSIBLE BEFORE ADDITIONAL AND MORE WIDESPREAD CONVECTION DEVELOPS ACROSS SOME OF THE REGION THROUGH LATE TONIGHT. ...CNTRL CA... WEAK DIURNAL DESTABILIZATION...COUPLED WITH MODEST TO STRONG ASCENT ASSOCIATED WITH MID/UPPER LEVEL SHORT WAVE TROUGH...HAS AIDED STORM INITIATION ALONG THE I5 CORRIDOR LATE THIS AFTERNOON. ADDITIONAL STORMS HAVE DEVELOPED IN THE NRN SIERRA. STRONGEST CELLS COULD PRODUCE HAIL OR PERHAPS A LOCALIZED NEAR-SEVERE WIND GUST OVER THE NEXT FEW HOURS BEFORE INABILITY WEAKENS AFTER SUNSET. ..CARBIN.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 06:14:54 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 02:14:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220609 SWODY1 SPC AC 220607 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SAT APR 22 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN VA AND THE CAROLINAS TO FL... ...SYNOPSIS... HIGHLY AMPLIFIED MULTI-STREAM UPPER FLOW WILL PERSIST ACROSS NORTH AMERICA THROUGH THE WEEKEND WITH A HIGH PLAINS UPPER RIDGE AXIS SEPARATING CLOSED LOWS OVER THE SOUTHWEST AND GREAT LAKES. A SRN BRANCH SHORT WAVE TROUGH UNDERCUTTING THE GREAT LAKES LOW WILL CONTINUE TO DRIVE A DEEP LAYER FRONTAL ZONE EWD ACROSS THE ATLANTIC COAST STATES FROM FL TO NJ. IN THE WAKE OF THIS SYSTEM... LOW LEVEL SLY FLOW WILL GRADUALLY STRENGTHEN FROM THE RIO GRANDE VALLEY ACROSS THE PLAINS AS LEE-SIDE TROUGHING BECOMES RE-ESTABLISHED OVER THE REGION. LOW LEVEL MOISTURE FLUX WILL ALSO INCREASE THROUGH TONIGHT FROM THE SRN HIGH PLAINS NWD/NEWD TO THE MO VALLEY AS BUILDING UPPER RIDGE TRANSPORTS ELEVATED MIXED LAYER AIR MASS EWD OFF THE ROCKIES ESCARPMENT. LASTLY...GREAT LAKES CUT-OFF LOW WILL BEGIN TO BE DISPLACED ESEWD THIS PERIOD AS A STRONG UPSTREAM TROUGH...CURRENTLY OVER BC...MOVES EAST. ...EAST COAST FROM SERN VA TO FL... LARGE SCALE ASCENT WILL SPREAD EAST ATOP MOIST BUT ONLY MARGINALLY UNSTABLE AIR MASS FROM THE APPALACHIANS EWD ACROSS MUCH OF NC AND VA THROUGH THE DAY. STRONGER INSTABILITY OVER MUCH OF THIS REGION MAY BE INHIBITED BY WIDESPREAD CONVECTIVE DEBRIS FROM ONGOING MCS CURRENTLY CROSSING THE SRN APPALACHIANS. HOWEVER...A NARROW WINDOW OF OPPORTUNITY FOR GREATER DESTABILIZATION IS SUGGESTED IN LATEST GUIDANCE FROM ERN SC ACROSS ERN NC WHERE MLCAPE IN THE RANGE OF 500-1500 J/KG MAY DEVELOP AHEAD OF MORE FOCUSED FORCING AND STRENGTHENING DEEP-LAYER FLOW NEAR POSSIBLE FRONTAL WAVE. THIS SHOULD ALLOW STORMS TO INCREASE IN INTENSITY/ORGANIZATION AS THE FRONT MOVES EAST FROM AFTERNOON THROUGH EVENING. A FEW MARGINAL HAIL/WIND EVENTS APPEAR POSSIBLE WITH THIS ACTIVITY...ALONG WITH A LOW PROBABILITY TORNADO THREAT. FARTHER SOUTH...STRONG IMPULSE ROTATING THROUGH THE BASE OF THE LARGE SCALE TROUGH WAS RESULTING IN STORMS INTENSIFYING ACROSS THE FL PANHANDLE EARLY TODAY. THIS ACTIVITY MAY CONTINUE EAST INTO SRN GA AND NRN FL THIS MORNING WITH THE CHANCE FOR WIND DAMAGE AND HAIL CONTINUING. LARGE SCALE HEIGHT FALLS WITH THE UPPER TROUGH WILL COMBINE WITH INCREASING DIURNAL INSTABILITY ACROSS FL TO PROMOTE ADDITIONAL STORM DEVELOPMENT THROUGH THE DAY. DEEP LAYER SHEAR OVER THE REGION WILL STRENGTHEN AND...COUPLED WITH POTENTIAL FOR SEABREEZE INTERACTIONS...RESULT IN ORGANIZED STORM UPDRAFTS WITH A CHANCE FOR HAIL/WIND AND PERHAPS A TORNADO. ...WEST TX/ERN NM... UPSLOPE FLOW AND RETURN OF 50S F DEWPOINTS TO THE SRN HIGH PLAINS WILL COMBINE WITH STRONG HEATING/MIXING TO SUPPORT ISOLATED HIGH-BASED CONVECTIVE DEVELOPMENT OVER THE HIGHER TERRAIN BY LATE AFTERNOON. EFFECTIVE SHEAR WILL BE MORE THAN ADEQUATE TO PROMOTE UPDRAFT ROTATION WITH A COUPLE OF THE MORE PERSISTENT CELLS POSSIBLY PRODUCING LARGE HAIL OR A SEVERE WIND GUST. LACK OF GREATER INSTABILITY AND STRONGER FORCING SHOULD KEEP SEVERE POTENTIAL LIMITED TO A FEW HOURS EITHER SIDE OF MAX HEATING. ...SERN LOWER MI/NRN IND/NWRN OH... LIMITED CLOUD COVER AND BOUNDARY LAYER HEATING SHOULD ALLOW FOR LAPSE RATES TO STEEPEN ACROSS LOWER MI AND PARTS OF THE UPPER MIDWEST AS CUT-OFF LOW SPREADS ESEWD DURING THE DAY. WEAK CAPE AND FORCING FOR ASCENT ON THE NOSE OF MID LEVEL JET STREAK DEVELOPING SEWD ACROSS IL/IND SHOULD SUPPORT LOW-TOPPED TSTM INITIATION WITH THE CHANCE FOR SCATTERED HAIL GIVEN LOW FREEZING LEVELS BENEATH/NEAR THE UPPER LOW. ...NERN KS TO MO... LOW LEVEL MOISTURE BEING TRANSPORTED BENEATH STRONG CAP WILL ENCOUNTER A ZONE OF FRONTOGENESIS ACROSS THE SCNTRL PLAINS/MO RIVER VALLEY FROM LATE TONIGHT INTO EARLY SUNDAY. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THIS PROCESS SHOULD ENHANCE THE CHANCES FOR ELEVATED TSTM DEVELOPMENT IN A BAND FROM EXTREME SERN NEB...ACROSS NERN KS...AND INTO NRN MO. IT IS POSSIBLE THAT ONE OR TWO STORMS COULD PRODUCE MARGINALLY SEVERE HAIL BEFORE DAYBREAK SUNDAY. ..CARBIN/TAYLOR.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 12:46:22 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 08:46:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221242 SWODY1 SPC AC 221239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0739 AM CDT SAT APR 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM FL TO SE VA.... ...SE ATLANTIC STATES TODAY... A SMALL MCS IS MOVING NEWD ACROSS NC/VA IN ASSOCIATION WITH AN MCV IN ADVANCE OF THE PRIMARY MID LEVEL TROUGH OVER GA. THIS INITIAL CONVECTION MAY PRODUCE MARGINAL SEVERE GUSTS AND SOME HAIL...THOUGH THE STORMS COULD MOVE ACROSS THE WARM SECTOR BEFORE SUBSTANTIAL SURFACE HEATING/DESTABILIZATION CAN TAKE PLACE. THE PRIMARY SEVERE STORM THREAT DURING THE DAY SHOULD EVOLVE FROM THE ONGOING CONVECTION OVER GA/SC IN ASSOCIATION WITH THE PRIMARY MID LEVEL TROUGH. THIS ACTIVITY WILL SPREAD NEWD AND SHOULD INTENSIFY BY LATE MORNING WHILE ENCOUNTERING STRONGER INSTABILITY OVER CENTRAL SC/NC. THE COMBINATION OF MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500 J/KG/ AND 35-45 KT LOW-MID LEVEL FLOW SHOULD SUPPORT A FEW BOWING LINE SEGMENTS...WHERE DAYTIME DESTABILIZATION OF THE BOUNDARY LAYER WILL ALLOW STRONGER DOWNDRAFTS AND MORE EFFICIENT MOMENTUM TRANSFER TO THE SURFACE. THE SEVERE THREAT SHOULD PERSIST THROUGH LATE AFTERNOON...AND THEN BEGIN TO DIMINISH THIS EVENING AS THE STRONGER CONVECTION MOVES OFFSHORE AND THE LOW LEVELS STABILIZE. THE INFLUENCE OF THE MID LEVEL TROUGH WILL EXTEND OVER N FL...WHERE ADDITIONAL THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE OUTFLOW BOUNDARY FROM THE MORNING STORMS ACROSS SW GA/FL PANHANDLE. OTHER ISOLATED SEVERE STORMS MAY FORM OVER THE INTERIOR PENINSULA DURING THE AFTERNOON IN ASSOCIATION WITH SEA BREEZE BOUNDARIES. AFTERNOON MLCAPE NEAR 1500 J/KG AND SOMEWHAT ENHANCED VERTICAL SHEAR ALONG AND E OF THE ATLANTIC COAST SEA BREEZE MAY PROVE SUFFICIENT FOR STORMS WITH SOME SUPERCELL CHARACTERISTICS. ...SE NM/W TX THIS EVENING/EARLY TONIGHT... A MID LEVEL SHORTWAVE RIDGE WILL MOVE E OF THE HIGH PLAINS BY AFTERNOON...WITH SWLY MID LEVEL FLOW CONTRIBUTING TO DEVELOPMENT OF A LEE TROUGH ACROSS ERN NM. MEANWHILE...BOUNDARY LAYER DEWPOINTS IN THE MID 40S TO UPPER 50S WILL SPREAD NWWD FROM THE MIDDLE RIO GRANDE VALLEY TO SE NM BY AFTERNOON. THIS MOISTURE...ALONG WITH SURFACE HEATING THROUGH BREAKS IN A BROAD CIRRUS PLUME...WILL RESULT IN POTENTIALLY MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500 J/KG/ BY LATE AFTERNOON NEAR AND IMMEDIATELY E OF THE LEE TROUGH. WIDELY SCATTERED THUNDERSTORMS MAY FORM LATE THIS AFTERNOON/EVENING ALONG THE LEE TROUGH INVOF SE NM...WHERE VERTICAL SHEAR AND INSTABILITY SHOULD BE AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS. THE PRIMARY SEVERE THREAT WILL BE LARGE HAIL INITIALLY...AND THEN A FEW DAMAGING GUSTS IF STORMS CAN GROW UPSCALE INTO ONE OR MORE SMALL MCS/S DURING THE EVENING WHILE SPREADING TOWARD W TX. ...ERN KS/WRN MO LATE TONIGHT... LOW-LEVEL MOISTURE SHOULD SPREAD NWD FROM TX TO THE ERN KS AREA BY LATER TONIGHT...WHEN THE LLJ WILL ENHANCE WAA ALONG AND N OF A BAROCLINIC ZONE ACROSS ERN KS/WRN MO. THE MOISTENING SHOULD BE SUFFICIENT FOR ELEVATED CONVECTION LATE TONIGHT...AND STEEP MID LEVEL LAPSE RATES MAY SUPPORT SOME HAIL WITH THE STRONGER STORMS. ...SRN LOWER MI AREA THIS AFTERNOON... SEVERAL SMALLER SCALE WAVES WILL CONTINUE TO ROTATE AROUND THE NRN WI CLOSED LOW WHILE IT DRIFTS SEWD TO LOWER MI BY TONIGHT. WITH DAYTIME HEATING...COLD MID LEVEL TEMPERATURES /NEAR -26 C AT 500 MB/ AND STEEP LOW-MID LEVEL LAPSE RATES WILL SUPPORT L0W-TOPPED THUNDERSTORMS CAPABLE OF PRODUCING MAINLY SMALL HAIL DURING THE AFTERNOON. ..THOMPSON/TAYLOR.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 17:05:04 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 13:05:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221700 SWODY1 SPC AC 221628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT SAT APR 22 2006 VALID 221630Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CAROLINAS INTO GA/FL... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OS SOUTHEAST LOWER MI INTO NORTHWEST OH... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WEST TX AND EASTERN NM... ...CAROLINAS... MORNING WATER VAPOR IMAGERY AND U/A ANALYSIS SHOWS UPPER RIDGE OVER THE CENTRAL UNITED STATES...AND A LARGE TROUGH FROM THE GREAT LAKES REGION ACROSS THE SOUTHEAST. PRIMARY SHORTWAVE TROUGH IS CURRENTLY OVER GA MOVING INTO THE CAROLINAS. THUNDERSTORMS ARE INTENSIFYING AHEAD OF THIS FEATURE ALONG THE SC/NC BORDER...WITH ISOLATED SEVERE STORMS EXPECTED THROUGH THE AFTERNOON INTO VA. SURFACE DEWPOINTS IN THE 60S AND WEAK DAYTIME HEATING WILL CONTRIBUTE TO MLCAPE VALUES OVER 1000 J/KG. RELATIVELY STRONG LOW/DEEP LAYER WIND FIELDS SHOULD AID CONVECTIVE ORGANIZATION WITH THE POTENTIAL FOR DAMAGING WINDS AND HAIL IN STRONGER CELLS. ...GA/FL... A CLUSTER OF STRONG THUNDERSTORMS IS ONGOING OVER THE EASTERN FL PANHANDLE. THESE STORMS WILL TRACK EASTWARD ACROSS NORTH FL EARLY THIS AFTERNOON...WHERE STRONG HEATING/DESTABILIZATION IS OCCURRING. POTENTIAL EXISTS FOR LOCALLY DAMAGING WINDS AND HAIL IN STRONGER CELLS BEFORE MOVING OFFSHORE. OTHER MORE ISOLATED STORMS MAY DEVELOP SOUTHWARD FROM THIS REGION ACROSS THE FL PENINSULA. WESTERLY FLOW WILL HELP TO MAXIMIZE CONVERGENCE ALONG THE EAST COAST SEA BREEZE THIS AFTERNOON AND EARLY EVENING. WET MICROBURSTS AND HAIL WOULD BE THE MAIN THREAT. REFER TO RECENT MCD NUMBER 615 FOR FURTHER DETAILS. ...EASTERN NM/WEST TX... CURRENT SHORTWAVE RIDGING ACROSS THE HIGH PLAINS WILL SHIFT EASTWARD TODAY DOWNSTREAM OF SOUTHWEST STATES UPPER TROUGH...WITH LEE TROUGH ACROSS THE SOUTHERN HIGH PLAINS. SOUTH/SOUTHEAST LOW LEVEL WINDS WILL SUPPORT A NORTHWARD TRANSPORT OF 50S F DEWPOINTS AND A POTENTIALLY UNSTABLE AIRMASS -- REF 12Z DEL RIO TX RAOB -- ACROSS THE SOUTHERN HIGH PLAINS. INITIAL CONVECTIVE DEVELOPMENT IS ANTICIPATED BY MID/LATE AFTERNOON ACROSS THE EASTERN NM PLAINS INTO FAR WEST TX/HIGHER TERRAIN OF SOUTHWEST TX...WITH THIS ACTIVITY SPREADING EASTWARD ACROSS WEST TX AND THE OK/TX PANHANDLES THIS EVENING. COMBINATION OF MODERATE INSTABILITY /1500-2000 J/KG MLCAPE/ AND VERTICAL SHEAR /25-30 KTS/ WILL FAVOR BOTH ORGANIZED MULTICELLS AND SUPERCELLS...WITH A PRIMARY HAZARD OF LARGE HAIL. IN ADDITION...AN INCREASING SOUTHERLY LOW LEVEL JET EARLY THIS EVENING MAY SUPPORT UPSCALE GROWTH AND ONE OR MORE SMALL MCS/S WITH A DAMAGING WIND THREAT AS ACTIVITY SPREADS ACROSS WEST TX. ...MI/OH... UPPER LOW CENTER IS FORECAST TO MOVE SLOWLY EASTWARD TODAY FROM WI INTO LOWER MI. STRONG DAYTIME HEATING IS OCCURRING AHEAD OF SYSTEM ACROSS SOUTHEAST LOWER MI AND NORTHWEST OH...WHERE STEEP LAPSE RATES AND MLCAPE VALUES OF 500-1000 J/KG WILL BE PRESENT. MODELS GENERALLY AGREE ON DEVELOPMENT OF SCATTERED THUNDERSTORMS LATER THIS AFTERNOON IN THIS REGION...CONTINUING INTO THE EARLY EVENING. LARGE HAIL SHOULD BE THE MAIN THREAT IN THIS REGION. ...CENTRAL CA... UPPER TROUGH REMAINS OVER CENTRAL CA TODAY...WITH COLD TEMPERATURES ALOFT AND STEEP LAPSE RATES IN PLACE. POCKETS OF DAYTIME HEATING WILL HELP TO DESTABILIZE AIR MASS...LEADING TO ISOLATED THUNDERSTORMS. MODEL GUIDANCE SUGGESTS PRIMARY THREAT AREA WILL BE ALONG THE FOOTHILLS OF THE SIERRAS WHERE UPSLOPE FLOW WILL ENHANCE CONVECTIVE POTENTIAL. ...KS/MO OVERNIGHT... LOW LEVEL WARM ADVECTION ZONE IS FORECAST TO DEVELOP ACROSS PARTS OF KS/MO LATER TONIGHT AS SURFACE COLD FRONT SAGS INTO REGION. INFLUX OF RELATIVELY MOIST/UNSTABLE AIR WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT MAINLY AFTER 06Z. FORECAST SOUNDINGS APPEAR FAVORABLE FOR LARGE HAIL IN STRONGEST STORMS. ..HART/GUYER.. 04/22/2006  From SwoDy1 at goshenarc.org Sat Apr 22 19:55:41 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 15:55:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221952 SWODY1 SPC AC 221950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SAT APR 22 2006 VALID 222000Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC AND SERN STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL GRTLKS REGION... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SRN HIGH PLAINS... ...MID-ATLANTIC AND SERN STATES... VORT MAX CONTINUES TO ROTATE ENEWD INTO UPSTATE SC THIS AFTN. WARM CONVEYOR AHEAD OF THIS FEATURE HAS SUPPORTED MULTIPLE BANDS OF STRONG-SEVERE TSTMS FROM THE DELMARVA REGION SWD INTO THE ERN CAROLINAS. STRONGEST LARGE SCALE ASCENT WILL BE MOVING QUICKLY NEWD INTO THE DELMARVA REGION AND THE ERN PORTIONS OF NC LATE THIS AFTN. SMALL SCALE LEWPS/BOWS MAY DEVELOP WITHIN THE BANDS OF TSTMS... GIVING LOCAL DAMAGING WINDS AND PERHAPS HAIL. UPSTREAM...AIR MASS SEEMS TO BE RECOVERING SOMEWHAT ALONG/JUST AHEAD OF THE PRIMARY COLD FRONT/ALONG AND E OF THE SRN APPALACHIAN CREST. DESPITE THE FACT THAT MAIN LLJ AXIS BEGINS TO SHIFT NEWD AWAY FROM THIS REGION...STEEP LAPSE RATES AND MODEST WSWLY UNIDIRECTIONAL FLOW MAY BE SUFFICIENT FOR ONE OR TWO SEVERE TSTMS WITH DAMAGING WINDS/HAIL ACROSS CNTRL NC-SC AND PARTS OF SERN/SCNTRL GA THROUGH THE EVENING HOURS. ...NRN/CNTRL FL... FARTHER S...STRONGER TSTMS HAVE BEEN FAVORING THE OUTFLOW BOUNDARY MOVING SWD THROUGH NRN FL AND ALONG THE SEABREEZE SOUTH OF THE CAPE. VERTICAL SHEAR WILL SUPPORT MAINLY MULTI-CELL TSTMS WITH BRIEF SUPERCELL STRUCTURES. DAMAGING WINDS AND PERHAPS HAIL SEEM TO BE THE PRIMARY SEVERE RISKS THROUGH EARLY EVENING. ...SRN HIGH PLAINS... MORE QUALITY LOW-LEVEL MOISTURE APPEARS TO HAVE ADVECTED ACROSS THE EDWARDS PLATEAU AND ALONG THE PECOS RVR VLY INTO SERN NM WHERE MID-AFTN SFC DEW POINTS WERE HOLDING IN THE MIDDLE 50S TO LOWER 60S BENEATH THE STRONG CAP IN PLACE. DIFFERENTIAL HEATING AND FAVORABLE DIURNAL CIRCULATION ARE CONTRIBUTING TO CONVECTION ALONG THE SRN NM AND SWRN TX MOUNTAINS. UPPER RIDGE AXIS SHOULD EDGE EWD LATER THIS AFTN...PROVIDING A MORE FAVORABLE ENVIRONMENT FOR THIS CONVECTION TO VENTILATE AND GROW INTO STORMS. CONTINUED HEATING ON THE ADJACENT PLAINS WILL PROBABLY WEAKEN THE CAP TO THE POINT WHERE STORMS WILL MOVE OFF THE MOUNTAINS AND SURVIVE. WHITE SANDS PROFILER SHOWS A RATHER DEEP SLY UNIDIRECTIONAL FLOW REGIME WITH VERTICAL SHEAR OF AROUND 35-40 KTS. TSTMS WILL PROBABLY DEVELOP INTO LINE SEGMENTS WITH PERHAPS BRIEF SUPERCELL STRUCTURES LATE THIS AFTN WITH LARGE HAIL THE PRIMARY THREAT. ACTIVITY MAY DEVELOP UPSCALE INTO ONE OR MORE MCS/S AND MOVE SLOWLY ENEWD THROUGH ERN NM AND WRN TX THROUGH THE EVENING WITH HAIL AND HIGH WINDS. ...CNTRL GRTLKS... COOLING ALOFT AND LARGE SCALE ASCENT ASSOCIATED WITH AN IMPULSE ROTATING AROUND THE GRTLKS UPPER LOW HAS BEEN SUPPORTING DEEPENING CONVECTION ACROSS THE REGION THIS AFTN. HAIL WILL BE THE PRIMARY THREAT WITH THIS ACTIVITY GIVEN THE STEEP LAPSE RATES. ADDITIONAL CONVECTION IS APT TO DEVELOP FARTHER SW WITHIN LOW-LEVEL THERMAL RIDGE ACROSS SRN MI INTO NRN IND AS A 70 KT JET STREAK NOSES SEWD LATER THIS AFTN. HERE...VERTICAL WIND PROFILES APPEAR SUPPORTIVE FOR LOW-TOPPED SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND GUSTS. ...CNTRL CA VLYS... UPPER TROUGH REMAINS OVER CENTRAL CA...WITH COLD TEMPERATURES ALOFT AND STEEP LAPSE RATES IN PLACE. POCKETS OF HEATING WILL HELP TO DESTABILIZE AIR MASS...LEADING TO ISOLATED THUNDERSTORMS. MODEL GUIDANCE SUGGESTS PRIMARY THREAT AREA WILL BE ALONG THE FOOTHILLS OF THE SIERRAS WHERE UPSLOPE FLOW WILL ENHANCE CONVECTIVE POTENTIAL. ...CNTRL PLAINS... LOW-LEVEL WARM ADVECTION ZONE IS INCREASING ACROSS PARTS OF KS/MO AS SURFACE COLD FRONT SAGS INTO REGION. INFLUX OF RELATIVELY MOIST/UNSTABLE AIR WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT THROUGH THE EVENING. FORECAST SOUNDINGS APPEAR FAVORABLE FOR LARGE HAIL IN STRONGEST STORMS. ..RACY.. 04/22/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:01:47 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:01:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230057 SWODY1 SPC AC 230056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 01:17:27 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 22 Apr 2006 21:17:27 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230113 SWODY1 SPC AC 230111 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 PM CDT SAT APR 22 2006 VALID 230100Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN NM AND FAR WEST TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN LOWER MICHIGAN... ...ERN NM/WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH EMBEDDED IN SOUTHWEST FLOW MOVING INTO WEST TX ATTM. LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE IS SUPPORTING A BROKEN LINE OF STORMS EXTENDING SWD FROM NEAR TUCUMCARI NM TO MIDLAND TX. THIS LINE SHOULD MOVE GRADUALLY EWD INTO WEST TX THROUGH THIS EVENING WHERE AN AXIS OF MODERATE INSTABILITY EXISTS. FORECAST SOUNDINGS THIS EVENING IN WEST TX SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE. THIS COMBINED WITH THE MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES WILL BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL. IN ADDITION...STEEP LOW-LEVEL LAPSE RATES AND LARGE TEMP-DEWPOINT SPREAD MAY ENHANCE THE POTENTIAL FOR ISOLATED WIND DAMAGE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY WEAKENS ACROSS THE REGION. ...ERN LOWER MI... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL LOW OVER LAKE MICHIGAN. STRONG LARGE-SCALE ASCENT...STEEP MID-LEVEL LAPSE RATES AND COLD TEMPS ALOFT ARE SUPPORTING SCATTERED STRONG THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL. THE HAIL THREAT SHOULD CONTINUE FOR MUCH OF THE EVENING BEFORE THE CONVECTION WEAKENS AS SFC TEMPS COOL AND STABILIZATION OCCURS. ...ATLANTIC COASTAL PLAINS... AN UPPER-LEVEL TROUGH IS CURRENTLY MOVING EWD ACROSS THE ATLANTIC COASTAL STATES. LARGE-SCALE ASCENT AHEAD OF THE TROUGH IS SUPPORTING A LINE OF THUNDERSTORMS FROM ERN NC EXTENDING SSWWD ACROSS SC AND SE GA. INSTABILITY HAS WEAKENED OVER THE LAST FEW HOURS DUE TO OUTFLOW FROM THE ACTIVITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES AROUND 30 KT SUGGEST INSTABILITY/SHEAR PROFILES ARE MARGINAL FOR SEVERE STORMS. ANY MARGINAL SEVERE THREAT WILL LIKELY DIMINISH THIS EVENING AS THE LINE OF STORMS GRADUALLY MOVES OFFSHORE. ...CNTRL PLAINS AND OZARKS... AN UPPER-LEVEL RIDGE IS CURRENTLY MOVING SLOWLY EWD ACROSS THE CNTRL PLAINS EVIDENT ON WATER VAPOR IMAGERY. ALTHOUGH THIS IS PROVIDING WEAK LARGE-SCALE ASCENT ACROSS THE REGION...SCATTERED THUNDERSTORMS ARE ONGOING IN SCNTRL MO DUE TO SFC HEATING AND LOW-LEVEL CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY. INSTABILITY AND SHEAR PROFILES APPEAR SUFFICIENT FOR A MARGINAL SEVERE THREAT BUT THE CONVECTION SHOULD GRADUALLY WEAKEN AS SFC TEMPS COOL THIS EVENING. FURTHER WEST ACROSS KS...A 50 KT LOW-LEVEL JET IS FORECAST TO INCREASE AND EXPAND ACROSS THE REGION TONIGHT. ISENTROPIC LIFT AND THE INSTABILITY IN PLACE SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE ERN HALF OF KS AROUND MIDNIGHT. FORECAST SOUNDINGS IN ECNTRL KS TONIGHT SHOW STRONG VERTICAL SHEAR PROFILES...STEEP MID-LEVEL LAPSE RATES AND ENOUGH INSTABILITY ABOVE 700 MB FOR A MARGINAL SEVERE THREAT. HAIL WOULD BE THE MOST LIKELY THREAT WITH ANY ELEVATED SUPERCELL STORMS THAT DEVELOP. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 06:15:18 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 02:15:18 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230609 SWODY1 SPC AC 230607 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SUN APR 23 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF PA AND NJ... ...CNTRL AND SRN PLAINS... AN UPPER-LEVEL TROUGH OVER THE WEST COAST IS FORECAST TO SLOWLY DRIFT ENEWD WITH HEIGHTS GRADUALLY FALLING ACROSS THE HIGH PLAINS. THIS WILL AID THE DEVELOPMENT OF A LEE SFC LOW OVER WRN KS WITH A SFC TROUGH/DRYLINE EXTENDING SWD INTO THE TX PANHANDLE. IN RESPONSE TO THE HEIGHT FALLS...A 50 KT LOW-LEVEL JET EARLY IN THE PERIOD WILL CONTINUE MOISTURE ADVECTION ACROSS WEST TX AND WRN KS THIS MORNING WITH SFC DEWPOINTS LIKELY INCREASING INTO THE 55 TO 60 F RANGE ACROSS MUCH OF THE REGION. AS SFC TEMPS WARM BY MIDDAY SUNDAY...MODERATE INSTABILITY SHOULD EXIST ALONG AND EAST OF A WEST TX/SWRN KS DRYLINE AND SOUTH OF A STATIONARY FRONT EXTENDING EWD ACROSS CNTRL KS. EARLY AFTERNOON FORECAST SOUNDINGS ACROSS THE WARM SECTOR SHOW A CAPPING INVERSION IN PLACE. THIS COMBINED WITH THE INFLUENCE OF THE UPPER-RIDGE SHOULD HOLD CONVECTIVE INITIATION OFF UNTIL THE MID-AFTERNO0N. THE MOST LIKELY AREAS FOR INITIAL CONVECTIVE DEVELOPMENT WOULD BE ALONG AND JUST EAST OF THE DRYLINE AND POSSIBLY ALONG THE BOUNDARY IN CNTRL AND ERN KS. FORECAST SOUNDINGS ACROSS THE REGION SHOW MODERATE DEEP LAYER SHEAR WHICH WITH THE INSTABILITY SHOULD BE ADEQUATE FOR SUPERCELL DEVELOPMENT IN THE LATE AFTERNOON AND EARLY EVENING. IN ADDITION...MODEL FORECASTS SHOW A PLUME OF VERY STEEP LAPSE RATES EXTENDING NEWD FROM THE SRN ROCKIES INTO THE CNTRL PLAINS. THIS SUGGESTS LARGE HAIL WILL BE LIKELY WITH THE STRONGER STORMS. IN ADDITION...AN ISOLATED TORNADO THREAT MAY ALSO DEVELOP IN SW KS AND ACROSS THE ERN TX AND OK PANHANDLES BY EARLY EVENING AS THE STORMS MOVE EWD INTO THE MOIST AXIS AND THE LOW-LEVEL JET STRENGTHENS AND EXPANDS ACROSS THE REGION. ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE WITH THE STRONGER SUPERCELL STORMS. AS STORMS INCREASE IN COVERAGE AND MOVE EWD INTO THE GREATER LOW-LEVEL MOISTURE...MCS DEVELOPMENT APPEARS LIKELY DURING THE EVENING. THE SEVERE THREAT COULD CONTINUE INTO WCNTRL OK AND ACROSS SCNTRL KS OVERNIGHT BUT THE THREAT SHOULD BECOME INCREASINGLY MARGINAL AFTER MIDNIGHT DUE TO DECREASING INSTABILITY. ...OZARK PLATEAU... AN UPPER-LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE PLAINS TODAY WITH NWLY FLOW ALOFT IN PLACE ACROSS THE OZARKS. AS SFC TEMPS WARM...MODERATE INSTABILITY SHOULD DEVELOP ALONG AND SOUTH OF A STATIONARY FRONTAL BOUNDARY EXTENDING EWD ACROSS SCNTRL MO. LOW-LEVEL CONVERGENCE IN THE AFTERNOON SHOULD BE STRONG ENOUGH TO OVERCOME A WEAK CAPPING INVERSION ALLOWING ISOLATED TO SCATTERED THUNDERSTORMS TO INITIATE. FORECAST SOUNDINGS ALONG THE BOUNDARY IN SCNTRL MO THIS AFTERNOON SHOW MODERATE VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES. THIS COMBINED WITH THE INSTABILITY SHOULD BE SUFFICIENT FOR ISOLATED SUPERCELL DEVELOPMENT DURING THE LATE AFTERNOON AND EARLY EVENING. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGEST STORMS. HOWEVER...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH DURING THE EVENING AS THE UPPER-RIDGE DRIFTS SLOWLY EWD AND INSTABILITY DECREASES ACROSS THE REGION. ...PA/NJ... AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL SHIFT ESEWD TODAY. IN RESPONSE...MID-LEVEL TEMPS WILL DROP FROM WEST TO EAST ACROSS THE CNTRL APPALACHIAN MTNS DURING THE AFTERNOON. THIS COMBINED WITH STRONG LARGE-SCALE ASCENT WILL MAKE THUNDERSTORM DEVELOPMENT LIKELY IN THE AFTERNOON. FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES AND MODERATE VERTICAL SHEAR WHICH SHOULD BE FAVORABLE FOR LARGE HAIL WITH STORMS THAT MOVE EWD ACROSS PA AND POSSIBLY AS FAR EAST AS WRN NJ DURING THE LATE AFTERNOON. HOWEVER...AS SFC TEMPS COOL IN THE EARLY EVENING...THE SEVERE THREAT SHOULD GRADUALLY DIMINISH. ..BROYLES.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 16:41:03 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 12:41:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231633 SWODY1 SPC AC 231632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT SUN APR 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL/SOUTHERN PLAINS... ...TX/OK/SRN KS... LARGE UPPER RIDGE REMAINS OVER THE CENTRAL UNITED STATES TODAY... WITH DEEP UPPER LOWS OVER CA...AND LOWER MI. CONTINUED SOUTHERLY LOW LEVEL WINDS ACROSS THE SOUTHERN PLAINS WILL MAINTAIN WIDESPREAD MID 50S TO LOWER 60S DEWPOINTS FROM KS INTO TX. STEEP LAPSE RATES AND STRONG DAYTIME HEATING SHOULD RESULT IN MLCAPE VALUES OF 1500-2000 J/KG ALONG AND EAST OF DRYLINE ALONG THE TX/NM BORDER INTO WESTERN KS. MORNING SOUNDINGS SHOW WARM 700MB TEMPERATURES ACROSS THIS REGION...BUT A GENERAL COOLING IS EXPECTED BY LATE AFTERNOON AS UPPER TROUGH SHIFTS SLOWLY EASTWARD AND SHORTWAVE TROUGH OVER MEXICO LIFTS NORTHEASTWARD. THIS SHOULD AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS FROM SOUTHWEST KS INTO THE NORTHERN/CENTRAL TX PANHANDLE...AND ISOLATED STORMS FROM THERE SOUTHWARD. DEEP LAYER VERTICAL SHEAR PROFILES OF 25-35 KNOTS WILL FAVOR ORGANIZED AND ISOLATED SUPERCELLULAR STRUCTURES CAPABLE OF LARGE HAIL AND DAMAGING WINDS. STORMS WILL LIKELY BE RATHER HIGH-BASED...ENHANCING THE THREAT OF DAMAGING WINDS. ACTIVITY IS EXPECTED TO SPREAD EASTWARD INTO PARTS OF WESTERN OK AND SOUTH CENTRAL KS DURING THE EVENING. ...SRN NEB/NRN KS... LATEST SURFACE ANALYSIS SHOWS WARM FRONT EXTENDING ACROSS CENTRAL KS INTO CENTRAL MO. STRONG DAYTIME HEATING IS OCCURRING NORTH OF BOUNDARY...WHERE WEAKER CAP AND ENHANCED LOW LEVEL WARM ADVECTION WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING. FAVORABLE SHEAR PROFILES IN THIS REGION SUGGEST A POTENTIAL FOR SUPERCELLS CAPABLE OF LARGE HAIL. IF ACTIVITY CAN ORGANIZE AND PROPAGATE EASTWARD ALONG BOUNDARY...DAMAGING WIND THREAT WOULD ALSO INCREASE. ...MO/IL/KS/TN... EASTWARD EXTENT OF SURFACE WARM FRONT LIES ACROSS CENTRAL MO INTO CENTRAL KY. AIR MASS ALONG AND SOUTH OF BOUNDARY WILL BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS IN THE 50S AND MLCAPE OVER 1000 J/KG. SCATTERED THUNDERSTORMS WILL BE POSSIBLE ALONG THIS AXIS...WITH LARGE HAIL POSSIBLE IN STRONGER CELLS. ...OH/PA/NY/VA/MD... FRONTAL BAND CONTINUES TO PUSH EASTWARD ACROSS EASTERN PA/CENTRAL NY. CLEARING SKIES BEHIND THIS ACTIVITY WILL ALLOW AIR MASS TO DESTABILIZE ACROSS PARTS OF MID ATLANTIC REGION THIS AFTERNOON. HOWEVER...LOW LEVEL MOISTURE IS WEAK AND DECREASING WITH TIME. PRESENT INDICATIONS ARE THAT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE IN THIS AREA...WITH HAIL POSSIBLE IN STRONGEST CELLS. HOWEVER...AN ORGANIZED SEVERE THREAT IS NOT CURRENTLY ANTICIPATED. ...FL... WARM/MOIST LOW LEVEL AIR MASS REMAINS IN PLACE OVER THE SOUTHERN FL PENINSULA TODAY...WHERE SCATTERED AFTERNOON THUNDERSTORMS ARE POSSIBLE. CONVERGENCE ALONG SOUTHEAST COAST SEA BREEZE...COMBINED WITH 30KT NORTHWEST FLOW ALOFT MAY RESULT IN ISOLATED STRONG STORMS CAPABLE OF GUSTY WINDS OR HAIL. ..HART/GUYER.. 04/23/2006  From SwoDy1 at goshenarc.org Sun Apr 23 20:02:01 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 16:02:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231955 SWODY1 SPC AC 231953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT SUN APR 23 2006 VALID 232000Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN HIGH PLAINS...CNTRL PLAINS...OZARKS AND THE LWR OH VLY... ...OZARKS EWD INTO LWR OH/TN VLYS THIS AFTN/EVE... UPPER LEVEL JETSTREAK TIED TO THE GRTLKS UPPER LOW HAS MAINTAINED A SWLY LLJ ACROSS THE SRN PLAINS INTO THE OZARKS THIS AFTN. UNSTABLE PARCELS HAVE BEEN REACHING THEIR LFC ACROSS CNTRL/SWRN MO AND NERN OK AND MOSTLY ELEVATED TSTMS HAVE BEEN PRODUCING SEVERE HAIL THIS AFTN. THOUGH THE HIGHER PROBABILITIES FOR SEVERE WEATHER WILL EXIST CLOSER TO THE INSTABILITY AXIS UPSTREAM...A FEW STRONGER STORMS ARE YET POSSIBLE EWD ACROSS THE TN/LWR OH VLYS THROUGH EVENING. ...CNTRL PLAINS TO THE OZARKS LATE THIS AFTN/TONIGHT... WATER VAPOR IMAGERY SHOWS A WEAK IMPULSE ROTATING NEWD ACROSS THE SRN ROCKIES THAT WILL MOVE INTO ERN CO LATER THIS EVENING. LARGE SCALE ASCENT ASSOCIATED WITH THIS FEATURE PROBABLY HAS CONTRIBUTED TO THE CONSIDERABLE HIGH-BASED CONVECTION OVER NERN NM AND ERN CO THIS AFTN. SFC ANALYSIS SHOWS THAT THE DRY HIGH PLAINS BOUNDARY LAYER WAS ADVECTING NEWD INTO THE NRN TX PNHDL AND SWRN KS WITH STRONGEST MASS CONVERGENCE DEVELOPING VCNTY THE WARM FRONT ACROSS WCNTRL-NCNTRL KS. THE WARM SECTOR CONTINUES TO DESTABILIZE OWING TO UNABATED HEATING AND SFC DEW POINTS REMAINING IN THE MID-UPPER 50S. AS CINH CONTINUES TO ERODE...THE HIGH-BASED CONVECTION APPROACHING FROM THE WEST WILL LIKELY GROW INTO THE UNSTABLE BOUNDARY LAYER AND INTENSIFY OVER WCNTRL/NWRN KS. OTHER STORMS WILL TEND TO DEVELOP ALONG/SWWD ALONG THE DRYLINE INTO SWRN KS AND THE TX/OK PNHDLS DURING THE EVENING. VERTICAL SHEAR REMAINS MARGINAL WITH MOST PROFILERS IN KS/OK SHOWING 30-35 KTS OF 6KM SHEAR. THUS...TSTMS WILL PROBABLY TEND TO CLUSTER AND BECOME OUTFLOW-DOMINANT WITH MAINLY LARGE HAIL AND DAMAGING WIND THREATS. GIVEN THE MAINTENANCE OF A SLY LLJ IMPINGING ON THE WARM FRONT OVERNIGHT...IT IS REASONABLE TO EXPECT TSTMS TO DEVELOP ESEWD ACROSS CNTRL KS AND INTO PARTS OF THE OZARKS THROUGH THE OVERNIGHT. STRONGER STORMS WILL CONTINUE TO HAVE A HAIL/GUSTY WIND THREAT. STORMS FARTHER S SHOULD WEAKEN WITH TIME AS THE DRYLINE RETREATS AND MOST OF THE MASS CONVERGENCE BECOMES CONFINED NE OF THE REGION. ...SRN HIGH PLAINS... LOW-LEVEL MOISTURE CONTINUES TO HUG THE HIGHER SWRN TX/SERN NM TERRAIN WHERE DIURNAL UPSLOPE CIRCULATION IS BEING ENHANCED BY AN UPSTREAM MEXICAN SHORTWAVE TROUGH. STRONG HEATING AND WEAK LARGE SCALE ASCENT SHOULD BE SUFFICIENT FOR MOUNTAIN CONVECTION TO SURVIVE ONTO THE PLAINS AGAIN THIS EVENING. THOUGH MID-AFTN VERTICAL SHEAR IS MARGINAL...THE FLOW ALOFT SHOULD INCREASE AS THE MEXICAN SHORTWAVE APPROACHES THE REGION. THUS...SUPERCELLS WILL BE POSSIBLE WITH LARGE HAIL AND DAMAGING WINDS. ...NRN PA/WRN NY... H5 SPEED MAX ROTATING AROUND THE PERIPHERY OF THE UPPER LOW CONTINUES TO DIG INTO THE UPPER OH VLY. RESIDUAL BOUNDARY LAYER DEW POINTS IN THE UPPER 40S BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES AND LOCAL SURFACE CONVERGENCE ALONG ATTENDANT FRONT WILL BE FAVORABLE FOR DIURNALLY-ENHANCED TSTMS PRODUCING MARGINALLY SEVERE HAIL OR GUSTY WINDS ACROSS MAINLY WRN NY THIS EVENING. ...NRN GRT BASIN... VORT MAX ROTATING AROUND THE COMPLEX UPPER LOW OVE SRN NV IS ENHANCING CONVECTION WITHIN A BROAD DEFORMATION ZONE ACROSS CNTRL/NERN NV THIS AFTN. STEEP LAPSE RATES AND PRESENCE OF DEEP ASCENT MAY AUGMENT HAIL PRODUCTION WITH ISOLD STORMS. ..RACY.. 04/23/2006  From SwoDy1 at goshenarc.org Mon Apr 24 01:05:36 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 21:05:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240101 SWODY1 SPC AC 240100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SUN APR 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE COLORADO... ...ERN KS/ERN OK/OZARK PLATEAU... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE PLAINS STATES WITH A PLUME OF MID-LEVEL MOISTURE EXTENDING EWD FROM SRN CO ACROSS SRN KS. AN MCS IS DEVELOPING IN THE MOIST PLUME ALONG THE AXIS OF THE RIDGE JUST SOUTH OF A FRONTAL BOUNDARY. THIS ACTIVITY WILL CONTINUE EWD ACROSS ERN KS AND NRN OK MOVING INTO INCREASING SFC DEWPOINTS AND MODERATE INSTABILITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES OF 30-35 KT AS SHOWN ON REGIONAL PROFILERS SHOULD BE SUFFICIENT FOR SUPERCELLS WITH STORMS THAT REMAIN DISCRETE OVER THE NEXT FEW HOURS. SEVERE MULTICELL STORMS AND/OR BOW ECHOES WILL ALSO BE LIKELY ESPECIALLY IN THE MORE INTENSE LINE SEGMENTS. THE GREATEST SEVERE THREAT SHOULD BE LARGE HAIL DUE TO THE STEEP LAPSE RATES IN PLACE BUT ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS ACROSS THE REGION LATER THIS EVENING. THE MCS SHOULD GRADUALLY MOVE EWD INTO SRN AND CNTRL MO OVERNIGHT WITH AN ISOLATED SEVERE THREAT CONTINUING. HOWEVER...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL AFTER MIDNIGHT. ...WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS SOUTHWEST FLOW IN PLACE ACROSS THE WRN PORTION OF THE SRN PLAINS WITH A DRY SLOT MOVING EWD ACROSS WEST TX. ISOLATED THUNDERSTORMS ARE DEVELOPING IN THE DRY SLOT NEAR A RETREATING DRYLINE. AS THE CONVECTION MOVES INTO INCREASING INSTABILITY THIS EVENING...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE ENOUGH FOR LARGE HAIL AND STRONG WIND GUSTS. HOWEVER...THE ACTIVITY SHOULD GRADUALLY WEAKEN LATER THIS EVENING DUE TO DECREASING INSTABILITY. ...NE CO/SW NEB... SSWLY FLOW IS CURRENTLY IN PLACE ACROSS NERN CO AHEAD OF AN UPPER-LOW DRIFTING EWD ACROSS NWRN AZ. A COLD FRONT IS MOVING SWD ACROSS ERN CO AND SCATTERED THUNDERSTORMS ARE DEVELOPING NORTH OF THE BOUNDARY ACROSS NERN CO WHERE SFC DEWPOINTS ARE IN THE 40S F. THE BOULDER WSR-88D VWP CURRENTLY SHOWS BACKED LOW-LEVEL FLOW WITH STRONG VEERING WIND PROFILES THROUGH 6 KM. THIS SUGGESTS THE SHEAR COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES SHOWN ON OBJECTIVE ANALYSIS SHOULD BE SUFFICIENT FOR SUPERCELL WITH A POTENTIAL FOR LARGE HAIL OVER THE NEXT FEW HOURS. HOWEVER...THE STORMS SHOULD EVENTUALLY WEAKEN LATER THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 03:06:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 23 Apr 2006 23:06:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240301 SWODY1 SPC AC 240300 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1000 PM CDT SUN APR 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND OZARK PLATEAU... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE COLORADO... CORRECTED TO REMOVE EXTRA THUNDER POINTS OVER CO ...ERN KS/ERN OK/OZARK PLATEAU... WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE PLAINS STATES WITH A PLUME OF MID-LEVEL MOISTURE EXTENDING EWD FROM SRN CO ACROSS SRN KS. AN MCS IS DEVELOPING IN THE MOIST PLUME ALONG THE AXIS OF THE RIDGE JUST SOUTH OF A FRONTAL BOUNDARY. THIS ACTIVITY WILL CONTINUE EWD ACROSS ERN KS AND NRN OK MOVING INTO INCREASING SFC DEWPOINTS AND MODERATE INSTABILITY. THIS COMBINED WITH 0-6 KM SHEAR VALUES OF 30-35 KT AS SHOWN ON REGIONAL PROFILERS SHOULD BE SUFFICIENT FOR SUPERCELLS WITH STORMS THAT REMAIN DISCRETE OVER THE NEXT FEW HOURS. SEVERE MULTICELL STORMS AND/OR BOW ECHOES WILL ALSO BE LIKELY ESPECIALLY IN THE MORE INTENSE LINE SEGMENTS. THE GREATEST SEVERE THREAT SHOULD BE LARGE HAIL DUE TO THE STEEP LAPSE RATES IN PLACE BUT ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS ACROSS THE REGION LATER THIS EVENING. THE MCS SHOULD GRADUALLY MOVE EWD INTO SRN AND CNTRL MO OVERNIGHT WITH AN ISOLATED SEVERE THREAT CONTINUING. HOWEVER...DECREASING INSTABILITY SHOULD ALLOW THE THREAT TO BECOME MARGINAL AFTER MIDNIGHT. ...WEST TX... WATER VAPOR IMAGERY CURRENTLY SHOWS SOUTHWEST FLOW IN PLACE ACROSS THE WRN PORTION OF THE SRN PLAINS WITH A DRY SLOT MOVING EWD ACROSS WEST TX. ISOLATED THUNDERSTORMS ARE DEVELOPING IN THE DRY SLOT NEAR A RETREATING DRYLINE. AS THE CONVECTION MOVES INTO INCREASING INSTABILITY THIS EVENING...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE ENOUGH FOR LARGE HAIL AND STRONG WIND GUSTS. HOWEVER...THE ACTIVITY SHOULD GRADUALLY WEAKEN LATER THIS EVENING DUE TO DECREASING INSTABILITY. ...NE CO/SW NEB... SSWLY FLOW IS CURRENTLY IN PLACE ACROSS NERN CO AHEAD OF AN UPPER-LOW DRIFTING EWD ACROSS NWRN AZ. A COLD FRONT IS MOVING SWD ACROSS ERN CO AND SCATTERED THUNDERSTORMS ARE DEVELOPING NORTH OF THE BOUNDARY ACROSS NERN CO WHERE SFC DEWPOINTS ARE IN THE 40S F. THE BOULDER WSR-88D VWP CURRENTLY SHOWS BACKED LOW-LEVEL FLOW WITH STRONG VEERING WIND PROFILES THROUGH 6 KM. THIS SUGGESTS THE SHEAR COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES SHOWN ON OBJECTIVE ANALYSIS SHOULD BE SUFFICIENT FOR SUPERCELL WITH A POTENTIAL FOR LARGE HAIL OVER THE NEXT FEW HOURS. HOWEVER...THE STORMS SHOULD EVENTUALLY WEAKEN LATER THIS EVENING AS INSTABILITY DROPS ACROSS THE REGION. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 06:04:56 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 02:04:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240600 SWODY1 SPC AC 240559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT MON APR 24 2006 VALID 241200Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KANSAS AND OKLAHOMA... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS...SRN PLAINS AND MID-MS VALLEY... ...GREAT PLAINS/MID-MS VALLEY... AN UPPER-LEVEL TROUGH OVER THE SWRN STATES IS FORECAST TO EJECT ENEWD ACROSS THE ROCKIES TODAY. A 70 KT MID-LEVEL JET ASSOCIATED WITH THE TROUGH WILL NOSE INTO THE CNTRL PLAINS THIS AFTERNOON INCREASING VERTICAL SHEAR PROFILES. THIS COMBINED WITH STRONG LARGE-SCALE ASCENT AND A VERY UNSTABLE AIRMASS WILL LIKELY RESULT IN WIDESPREAD SEVERE WEATHER ACROSS THE REGION THIS AFTERNOON AND TONIGHT. SEVERAL MESOSCALE CONVECTIVE SYSTEMS SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD. MODEL FORECASTS VALID AT 12Z GENERALLY AGREE KEEPING MOST OF THE CONVECTIVE CLUSTERS ACROSS SRN NEB...NERN KS AND WRN MO. THE LACK OF CONVECTION ALONG WITH A CAPPING INVERSION SHOULD KEEP THE AIRMASS ACROSS THE MODERATE RISK AREA UNDISTURBED THROUGH MIDDAY. CONTINUED MOISTURE ADVECTION DURING THE DAY SHOULD BRING SFC DEWPOINTS IN THE MID 60S F AS FAR NORTH AS CNTRL KS. THIS SHOULD RESULT IN MODERATE TO STRONG INSTABILITY BY AFTERNOON ACROSS THE WARM SECTOR. AS A COLD FRONT APPROACHES CNTRL KS DURING THE AFTERNOON...INCREASING LOW-LEVEL CONVERGENCE AND THE WEAKENING CAP SHOULD RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT WITH STORMS DEVELOPING SWD TOWARD THE OK STATELINE. VERTICAL SHEAR SHOULD GRADUALLY INCREASE DURING THE DAY AS A MID-LEVEL JET PUNCHES INTO THE REGION. FORECAST SOUNDINGS AT 21Z ACROSS THE MODERATE RISK AREA SHOW 0-6 KM SHEAR VALUES OF 40 TO 50 KT WHICH COMBINED WITH STEEP LAPSE RATES AND STRONG INSTABILITY SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE MORE INTENSE SUPERCELLS WILL ALSO HAVE A POTENTIAL FOR VERY LARGE HAIL AND TORNADOES...ESPECIALLY AS THE LOW-LEVEL JET EXPANDS NWD ACROSS THE REGION IN THE LATE AFTERNOON AND EARLY EVENING. A LINEAR MCS SHOULD GRADUALLY DEVELOP AS SUGGESTED BY THE WRF-NMM/NAM AND GFS WITH THE WIND DAMAGE POTENTIAL BECOMING ENHANCED DURING THE EVENING HOURS ACROSS THE OZARK PLATEAU. ALTHOUGH THE MCS MAY CONTINUE WITH THE MCS INTO SRN MO AND NRN AR AFTER MIDNIGHT...ANY SEVERE THREAT SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. FURTHER SOUTH ACROSS OK AND NRN/CNTRL TX STRONG INSTABILITY WILL LIKELY BE IN PLACE WITH SFC DEWPOINTS IN THE MID TO UPPER 60S F. FORECAST SOUNDINGS SHOW A CAPPING INVERSION REMAINING IN PLACE THROUGH MUCH OF THE AFTERNOON AHEAD OF A DRYLINE EXTENDING SSWWD FROM NEAR WICHITA FALLS INTO THE TX HILL COUNTRY. AS LOW-LEVEL CONVERGENCE INCREASES EAST OF THE DRYLINE...ISOLATED THUNDERSTORMS SHOULD INITIATE AND MOVE EWD ACROSS THE I-35 CORRIDOR. STRONG INSTABILITY...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL AND ISOLATED WIND DAMAGE. A FEW TORNADOES WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS IN NCNTRL AND NERN OK WHERE THE LOW-LEVEL JET IS FORECAST TO STRENGTHEN IN THE EARLY EVENING. DECREASING INSTABILITY AND A STRENGTHENING CAPPING INVERSION SHOULD RESULT IN A GRADUAL DECREASE OF THE SEVERE THREAT BY LATE EVENING. ..BROYLES.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 12:35:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 08:35:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241231 SWODY1 SPC AC 241229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT MON APR 24 2006 VALID 241300Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF NRN OK AND SRN KS.... ...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT ELSEWHERE FROM NRN KS SWD TO CENTRAL TX...AND EWD TO NW AR/MO/SRN IL.... ...SYNOPSIS... THE CLOSED MID LEVEL LOW OVER THE SRN GREAT BASIN IS EVOLVING INTO AN OPEN WAVE...AND THIS SYSTEM WILL EJECT EWD TO THE HIGH PLAINS BY TONIGHT. A SEPARATE NRN STREAM WAVE WILL MOVE FROM MANITOBA TO THE UPPER GREAT LAKES. IN THE WAKE OF THIS NRN STREAM TROUGH...A SURFACE RIDGE WILL BUILD SEWD ACROSS THE PLAINS...DRIVING A COLD FRONT SEWD ACROSS OK/NW TX AND THE MID MS VALLEY BY THE END OF THE PERIOD. AN INITIAL LEE CYCLONE OVER SW KS THIS MORNING IS EXPECTED TO DEVELOP EWD ALONG AN E-W BAROCLINIC ZONE ACROSS KS/MO...OR PERHAPS ALONG A COMPOSITE OUTFLOW BOUNDARY LINGERING ACROSS NRN OK...IN ADVANCE OF THE GREAT BASIN TROUGH. THE SURFACE LOW AND THESE SURFACE BOUNDARIES WILL FOCUS THE SEVERE STORM THREAT THROUGH EARLY TONIGHT ACROSS KS AND NRN OK. ...KS/OK/MO AREA THROUGH TONIGHT... THE FIRST MCS IN THE SEQUENCE HAS DISSIPATED OVER SE MO...LEAVING AN OUTFLOW BOUNDARY FROM NRN AR INTO NRN OK. A SECOND SMALL MCS IS WEAKENING OVER NE OK/NW AR...AND THIS CONVECTION IS REINFORCING THE EARLIER OUTFLOW ACROSS NRN OK. OTHER ELEVATED STORMS PERSIST ACROSS CENTRAL/NE KS AND SE NEB IN ASSOCIATION WITH WAA AND LIFT ALONG THE SURFACE COLD FRONT. GIVEN THE RELATIVELY WIDESPREAD CONVECTION ACROSS KS...THE EFFECTIVE SURFACE BOUNDARY MAY END UP BEING THE RESIDUAL OUTFLOW NEAR THE KS/OK BORDER BY AFTERNOON. A FEED OF UNDISTURBED WARM SECTOR AIR /WITH BOUNDARY LAYER DEWPOINTS OF 62-64 F/ WILL PERSIST TODAY ACROSS CENTRAL AND WRN OK INTO THE OUTFLOW BOUNDARY NEAR THE KS/OK BORDER. STRONG SURFACE HEATING BENEATH STEEP MID LEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPE VALUES OF 2000-3000 J/KG IN THE WARM SECTOR...AND PERHAPS 1000-2000 J/KG IN THE ZONE BETWEEN THE OUTFLOW BOUNDARY AND RESIDUAL E-W BAROCLINIC ZONE IN KS. THERE IS SOME UNCERTAINTY REGARDING THE EVOLUTION OF THE ONGOING STORMS IN KS. HOWEVER...IT APPEARS LIKELY THAT ADDITIONAL STORMS WILL FORM BY MID AFTERNOON NEAR THE SURFACE TRIPLE POINT...CLOSE TO A LINE FROM P28-END. INCREASING MID-UPPER WSWLY FLOW...ALONG WITH BACKED LOW-LEVEL WINDS NEAR THE OUTFLOW BOUNDARY AND E OF THE SURFACE LOW...WILL PROVIDE SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS. VERY LARGE HAIL AND A FEW TORNADOES WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING...ESPECIALLY IF THE OUTFLOW BOUNDARY CAN MAINTAIN ITS IDENTITY WITH A BELT OF BACKED LOW-LEVEL FLOW AND MID 60 DEWPOINTS. LATER DURING THE EVENING...CONVECTION SHOULD GROW UPSCALE INTO ANOTHER MCS WITH LARGE HAIL AND DAMAGING WINDS ACROSS SRN KS AND NRN OK...POSSIBLY REACHING SW MO AND NW AR LATE TONIGHT. OTHER MORE ISOLATED STORMS MAY FORM ALONG THE COLD FRONT OVERNIGHT INTO CENTRAL TX...WHILE THE ERN EXTENT OF THE SEVERE THREAT WILL BE LIMITED BY GRADUALLY WEAKENING INSTABILITY OVERNIGHT ACROSS MO/AR. ..THOMPSON/TAYLOR.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 16:27:13 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 12:27:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241623 SWODY1 SPC AC 241621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT MON APR 24 2006 VALID 241630Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SOUTH CENTRAL KS AND WESTERN/NORTHERN OK... ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX ACROSS MUCH OF OK/KS AND INTO THE MID MS VALLEY... ...REGIONAL SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING OVER PARTS OF KS/OK... ...KS/OK... LARGE UPPER TROUGH IS PRESENT THIS MORNING OVER THE WESTERN STATES...WITH BAND OF 40-60 KNOT SOUTHWESTERLY MID LEVEL WINDS EXTENDING FROM AZ/NM INTO WESTERN KS. THESE WIND FIELDS ARE FORECAST TO SHIFT EASTWARD BY THIS AFTERNOON ACROSS MUCH OF KS/OK...ALONG WITH INCREASED LARGE SCALE FORCING FOR ASCENT. SCATTERED THUNDERSTORMS WILL DEVELOP NEAR SURFACE LOW OVER SOUTHWEST KS...AND SOUTHWARD ALONG DRYLINE INTO ACROSS WESTERN OK. SIGNIFICANT SUPERCELLS CAPABLE OF VERY LARGE HAIL...DAMAGING WINDS...AND A FEW TORNADOES APPEAR POSSIBLE. MORNING SURFACE ANALYSIS SHOWS MULTIPLE OUTFLOW BOUNDARIES LYING ACROSS SOUTH CENTRAL KS AND NORTHERN OK. PRESENT INDICATIONS ARE THAT BACKED FLOW NORTH OF THESE BOUNDARIES WILL WEAKEN BUT REMAIN IN PLACE THROUGH THIS AFTERNOON. MODELS ALSO HINT AT SECONDARY SURFACE LOW DEVELOPMENT OVER SOUTHWEST OK ALONG APPROACHING COLD FRONT. THIS WILL TEND TO BACK LOW LEVEL WINDS FARTHER SOUTH ALONG DRYLINE ACROSS WESTERN OK AS WELL. INCREASING WIND FIELDS ALOFT THIS AFTERNOON WILL YIELD LOCAL EFFECTIVE HELICITY VALUES OVER 200 M2/S2 AND EFFECTIVE SHEAR OF 30-40 KNOTS ACROSS THIS REGION. THERMODYNAMIC PROFILES WILL BE EXTREMELY FAVORABLE FOR SEVERE STORMS AS SURFACE DEWPOINTS RISE THROUGH THE 60S BENEATH STEEP LAPSE RATES...WITH AFTERNOON MLCAPE VALUES EXCEEDING 3000 J/KG. EXPECT STORMS TO RAPIDLY INTENSIFY NEAR SURFACE LOW/OUTFLOW BOUNDARIES NEAR THE OK/KS BORDER BY MID AFTERNOON...WITH DEVELOPMENT SOUTHWARD ALONG DRYLINE BY EARLY EVENING. VERY LARGE HAIL WILL BE LIKELY...ALONG WITH THE POTENTIAL FOR DAMAGING WINDS AND A FEW TORNADOES. AT THIS TIME...GREATEST THREAT OF TORNADOES APPEARS TO BE IN VICINITY OF TRIPLE POINT/REMNANT OUTFLOW BOUNDARIES FROM SOUTH CENTRAL KS INTO NORTHWEST/NORTH CENTRAL OK. FRONTAL CONVERGENCE MAY TEND TO FOCUS STORMS INTO SQUALL LINE DURING THE EVENING WITH AN ENHANCED THREAT OF DAMAGING WINDS ACROSS MUCH CENTRAL/EASTERN OK AND SOUTHEAST KS. ...TX... STRONG HEATING ALONG SURFACE DRYLINE MAY ALSO RESULT IN ISOLATED SEVERE STORM DEVELOPMENT AS FAR SOUTH AS CENTRAL TX THIS AFTERNOON/EVENING. WARM TEMPERATURES ALOFT AND MINIMAL FORCING SUGGEST ACTIVITY WILL REMAIN VERY ISOLATED AND MAY WEAKEN SHORTLY AFTER SUNSET. ..HART/GUYER.. 04/24/2006  From SwoDy1 at goshenarc.org Mon Apr 24 22:38:51 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 24 Apr 2006 18:38:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 242234 SWODY1 SPC AC 242233 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0533 PM CDT MON APR 24 2006 VALID 242000Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PORTIONS OF OK AND S-CNTRL KS... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PORTIONS OF THE CNTRL AND SRN PLAINS INTO THE MD MS VALLEY... ...CNTRL/SRN PLAINS... SURFACE ANALYSIS INDICATES COMPLEX SURFACE PATTERN THIS AFTERNOON ACROSS REGION. PRIMARY COLD FRONT APPEARS TO EXTEND FROM S-CNTRL/SERN NEB SSWWD TO LOW PRESSURE OVER NWRN OK AND THEN INTO THE SRN TX PNHDL. AN OUTFLOW BOUNDARY /SLOWLY SAGGING SWWD/ EXTENDS FROM THIS LOW PRESSURE AREA OVER NWRN OK ESEWD TO ONGOING MCS OVER NERN OK INTO NWRN AR. A SECONDARY LOW HAS BECOME BETTER DEFINED OVER SWRN OK AT INTERSECTION OF COLD FRONT WITH DRY LINE WHICH EXTENDS SWD INTO W-CNTRL TX. 18Z OUN SOUNDING INDICATES THAT BOUNDARY-LAYER HAS MOISTENED SINCE 12Z WITH DEWPOINTS IN THE MID TO UPPER 60S. THIS MOISTURE COUPLED WITH STEEP MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO A MODERATELY TO POTENTIALLY STRONGLY UNSTABLE AIR MASS WITH MLCAPES OF 2000-3000 J/KG. VISIBLE SATELLITE AND THIS SOUNDING DATA SUGGEST THAT DAYTIME HEATING HAS NEARLY ERODED REMAINING CAP ALONG DRY LINE AND OUTFLOW BOUNDARY WITH EXPLOSIVE TSTM DEVELOPMENT ANTICIPATED BY 21-22Z. GIVEN THE DEGREE OF INSTABILITY...SUPERCELLS CAPABLE OF VERY LARGE HAIL APPEAR LIKELY. WHILE DEEP-LAYER VERTICAL SHEAR WAS MARGINAL /30-35 KTS/ ON THE 18Z OUN SOUNDING...PROFILER/VAD DATA INDICATE THAT MID-LEVEL WIND FIELDS ARE INCREASING FROM THE W OVER THE CNTRL AND SRN HIGH PLAINS. IT APPEARS THE GREATEST POTENTIAL FOR A FEW TORNADOES WILL BE WITH STORMS THAT CAN INITIATE ALONG THE DRY LINE...MATURE AND THEN CROSS OR MOVE NEARLY ALONG OUTFLOW BOUNDARY OVER NWRN AND N-CNTRL OK. THIS TORNADO THREAT WILL ALSO EXIST THROUGH THE AFTERNOON INTO EVENING ALONG NARROW INSTABILITY AXIS INTO SWRN KS. MORE ISOLATED STORMS WILL ALSO BE POSSIBLE FROM SWRN OK INTO NWRN AND PERHAPS W-CNTRL TX FROM NEAR SECONDARY TRIPLE POINT SWD ALONG DRY LINE. THOUGH DEEP-LAYER VERTICAL SHEAR DECREASES WITH SWD EXTENT...THE DEGREE OF INSTABILITY SUGGESTS THE POTENTIAL FOR SUPERCELLS CAPABLE OF LARGE HAIL. FINALLY...ONGOING MCS OVER NERN OK INTO NWRN AR HAS ORGANIZED A COLD POOL SUFFICIENTLY THAT IT HAS STARTED TO FORWARD PROPAGATE THIS AFTERNOON. INFLUX OF MODERATE TO STRONG INSTABILITY FROM THE SW SHOULD MAINTAIN THIS COMPLEX SEWD ACROSS FAR ERN OK AND AR WITH A CONTINUED THREAT OF DAMAGING WINDS AND LARGE HAIL. ..MEAD.. 04/24/2006  From SwoDy1 at goshenarc.org Tue Apr 25 06:03:15 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 02:03:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250559 SWODY1 SPC AC 250557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT TUE APR 25 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...LOWER MS VALLEY...TN VALLEY AND CAROLINAS... ...LOWER MS VALLEY/SRN PLAINS... AT UPPER-LEVELS...A FLAT RIDGE OVER THE MS VALLEY EARLY IN THE PERIOD WILL WEAKEN AS A BROAD TROUGH DEVELOPS ACROSS THE PLAINS AND MOVES TOWARD THE MS VALLEY. AT THE SFC...A COLD FRONT WILL MOVE SEWD ACROSS THE SRN PLAINS/OZARKS AND A LINEAR MCS MAY BE ONGOING ALONG AND AHEAD OF THE BOUNDARY AT THE BEGINNING OF THE PERIOD. AHEAD OF THE MCS ACROSS THE LA AND TX COASTAL PLAINS...SFC HEATING AND DEWPOINTS IN THE 65 TO 70 F RANGE SHOULD RESULT IN MODERATE INSTABILITY BY MIDDAY. ALTHOUGH LARGE-SCALE ASCENT IS FORECAST TO BE WEAK...INCREASING LOW-LEVEL CONVERGENCE AHEAD OF THE FRONTAL ZONE SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION DURING THE AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW MODERATE VERTICAL SHEAR PROFILES AND STEEP MID-LEVEL LAPSE RATES SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL ESPECIALLY UPON INITIATION. HOWEVER...AS STORMS INCREASE IN COVERAGE BY THE LATE AFTERNOON AND EARLY EVENING...THE DOMINANT STORM MODE REMAINS QUESTIONABLE. THE WEAK LARGE-SCALE ASCENT AND LINEARLY ORIENTED CONVERGENCE ZONE MAY HELP STORMS TO ORGANIZE QUICKLY INTO A LINE. IF THIS OCCURS...THE STRONGER CELLS IN THE LINE SHOULD STILL BE CAPABLE OF LARGE HAIL AND ISOLATED WIND DAMAGE. THE LINE SHOULD CONTINUE SEWD MOVING INTO THE IMMEDIATE COASTAL AREAS BY THE EARLY EVENING. FURTHER SOUTH ACROSS SOUTH TX AND THE TX HILL COUNTRY...FORECAST SOUNDINGS SHOW INCREASING VERTICAL SHEAR PROFILES DURING THE DAY AS A MID-LEVEL JET NOSES INTO THE REGION. THIS COMBINED WITH MODERATE INSTABILITY AND STEEP MID-LEVEL LAPSE RATES SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND ISOLATED WIND DAMAGE AS STORMS INITIATE IN THE AFTERNOON. DUE TO THE STRONGER VERTICAL SHEAR...THE SUPERCELL POTENTIAL THROUGH THE LATE AFTERNOON AND EVENING APPEARS GREATER THAN AREAS FURTHER NORTH. THIS COULD SUSTAIN THE THREAT FOR LARGE HAIL AND WIND DAMAGE THREAT LONGER INTO THE EVENING. HOWEVER...ANY SEVERE THREAT SHOULD DIMINISH BEFORE MIDNIGHT DUE TO THE RELATIVELY WEAK LARGE-SCALE ASCENT AND DECREASING INSTABILITY. ...TN VALLEY/SRN APPALACHIANS/CAROLINAS... AT UPPER-LEVELS...A BROAD RIDGE OVER THE MS VALLEY WILL DRIFT EWD AND DAMPEN OUT IN WLY FLOW. AT THE SFC...A COLD FRONT WILL MOVE SWD ACROSS THE REGION. SOUTH OF THE BOUNDARY...SFC DEWPOINTS IN THE 60S F SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP BY AFTERNOON. ALTHOUGH LARGE-SCALE ASCENT SHOULD REMAIN RELATIVELY WEAK...STRENGTHING LOW-LEVEL CONVERGENCE ALONG AND AHEAD OF THE FRONTAL BOUNDARY AND SFC HEATING SHOULD ALLOW STORMS TO INITIATE IN TN...NRN AL AND THE SRN APPALACHIAN MTNS DURING THE AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW THE STRONGEST VERTICAL SHEAR PROFILES ACROSS TN AND THE SRN APPALACHIAN MTNS WHERE THE SEVERE THREAT WILL LIKELY BE THE GREATEST. 0-6 KM SHEAR VALUES OF 30 TO 40 KT SHOULD BE SUFFICIENT FOR SUPERCELLS BEFORE A GRADUAL TRANSITION TO LINEAR DEVELOPMENT WHICH IS LIKELY IN THE LATE AFTERNOON. THE STRONGER CELLS IN THE LINE SHOULD BE CAPABLE OF LARGE HAIL AND ISOLATED WIND DAMAGE ESPECIALLY NEAR PEAK HEATING. HOWEVER...THE LINE SHOULD GRADUALLY WEAKEN DURING THE EARLY EVENING AS THE CONVECTION ENCOUNTERS WEAKER VERTICAL SHEAR OVER CNTRL AL AND NCNTRL GA. FURTHER EAST ACROSS THE CAROLINAS...WEAK INSTABILITY SHOULD DEVELOP AHEAD OF A SFC LOW AND FRONTAL BOUNDARY BY AFTERNOON. THIS COMBINED WITH MODERATE VERTICAL SHEAR SHOWN ON FORECAST SOUNDINGS SHOULD BE SUFFICIENT FOR AT LEAST AN ISOLATED SEVERE THREAT. ALTHOUGH SUPERCELLS WILL BE POSSIBLE...QUESTIONS REMAIN CONCERNING INSTABILITY. IF MODERATE INSTABILITY DEVELOPS...A FEW SUPERCELLS WITH LARGE HAIL AND WIND DAMAGE COULD DEVELOP. HOWEVER...ANY SEVERE THREAT SHOULD GRADUALLY DECREASE BY EARLY EVENING AS INSTABILITY WEAKENS AND THE FRONT MOVES SWD ACROSS THE REGION. ..BROYLES.. 04/25/2006  From SwoDy1 at goshenarc.org Tue Apr 25 12:40:20 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 08:40:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251236 SWODY1 SPC AC 251234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT TUE APR 25 2006 VALID 251300Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM SRN AND ERN TX ACROSS THE LOWER MS VALLEY TO NC.... ...SYNOPSIS... A NRN STREAM TROUGH IS DIGGING SEWD OVER THE GREAT LAKES...AND THE REMNANTS OF A SRN STREAM TROUGH ARE EJECTING EWD FROM THE HIGH PLAINS IN A CONFLUENT FLOW REGIME. A WEAK SURFACE WAVE WILL DEVELOP EWD IN ADVANCE OF THESE MID LEVEL TROUGHS...ALONG A LOW-LEVEL BAROCLINIC ZONE FROM KY TO NC. SW OF THE SURFACE WAVE...THE COLD FRONT WILL MOVE SEWD ACROSS TX/AR/LA. THE SURFACE FRONT...ALONG WITH A RESIDUAL OUTFLOW BOUNDARY FROM A WEAKENING MCS IN AR...WILL FOCUS FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT TODAY INTO EARLY TONIGHT. ...SRN AND ERN TX/LA AREA... THE COLD FRONT IS MOVING SEWD ACROSS NRN AND CENTRAL TX...AND THIS FRONT SHOULD EXTEND FROM SRN AR ACROSS NW LA AND SE/S CENTRAL TX BY MID AFTERNOON. ADDITIONALLY...AN OUTFLOW BOUNDARY FROM ONGOING STORMS IN AR/SE OK WILL MOVE SWD AND HELP FOCUS ADDITIONAL CONVECTIVE DEVELOPMENT ACROSS NE TX AND NRN LA TODAY. SW OF THE OUTFLOW BOUNDARY AND AHEAD OF THE COLD FRONT...DAYTIME HEATING...BOUNDARY LAYER DEWPOINTS OF 68-72 F AND 7-8 C/KM MID LEVEL LAPSE RATES WILL SUPPORT MLCAPE VALUES OF 2500-3000 J/KG. FORECAST SOUNDINGS ACROSS S CENTRAL TX APPEAR SUPPORTIVE OF SUPERCELLS ALONG THE FRONT THIS AFTERNOON ONCE CONVECTIVE INHIBITION WEAKENS...WITH MULTICELLULAR CONVECTION EXPECTED FARTHER NE ACROSS E TX/LA. LARGE HAIL AND A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREATS WITH THESE STORMS THIS AFTERNOON...AND THE SEVERE THREAT SHOULD DIMINISH LATER THIS EVENING. ...ERN AR/NRN MS AND AL/TN AREA... THE CONVECTION AND ASSOCIATED COLD POOL OVER AR...AND A SEPARATE MCV OVER SE MO...MAY PERSIST AND SPREAD EWD/SEWD DURING THE DAY ACROSS NW MS AND WRN TN. INSTABILITY WILL BE SOMEWHAT WEAKER THIS AREA COMPARED TO TX...BUT ISOLATED DAMAGING DOWNBURST WINDS AND MARGINALLY SEVERE HAIL WILL BE POSSIBLE DURING THE DAY AS THE LOW LEVELS DESTABILIZE. THE SEVERE THREAT WITH THIS CONVECTION WILL LIKELY DIMINISH THIS EVENING. ...NC AREA THIS AFTERNOON/EVENING... A REMNANT MCV OVER ERN TN WILL MOVE EWD INVOF OF A QUASI-STATIONARY FRONT ACROSS NC. DAYTIME HEATING WILL PROMOTE THE DEVELOPMENT OF A RELATIVELY DEEP BOUNDARY LAYER AND STEEP LOW-LEVEL LAPSE RATES E OF THE MOUNTAINS AND S OF THE FRONT...ALONG WITH AT LEAST WEAK SURFACE-BASED INSTABILITY. DEEP LAYER WLY PROFILES WITH SUBSTANTIAL SPEED INCREASE WITH HEIGHT ALOFT MAY SUPPORT A FEW MARGINAL SUPERCELL OR BOW TYPE STORMS THIS AFTERNOON INTO THIS EVENING NEAR THE FRONTAL ZONE. ISOLATED DAMAGING GUSTS AND MARGINALLY SEVERE HAIL WILL BE THE MAIN SEVERE THREATS. ..THOMPSON/TAYLOR.. 04/25/2006  From swody1 at goshenarc.org Tue Apr 25 16:24:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 12:24:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251619 SWODY1 SPC AC 251617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CDT TUE APR 25 2006 VALID 251630Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX ACROSS THE LOWER MS AND TN VALLEYS INTO NC... MODERATELY FAST ZONAL FLOW PATTERN HAS DEVELOPED ACROSS MUCH OF THE CENTRAL/EASTERN UNITED STATES TODAY...WITH 30-40 KNOT WESTERLY FLOW ALOFT FROM OK/TX INTO THE CAROLINAS. PRIMARY SURFACE BAROCLINIC ZONE EXTENDS FROM CENTRAL TX INTO SOUTHERN MO...THEN EASTWARD ACROSS KY INTO SOUTHERN VA. WIDESPREAD MOIST AND AT LEAST MARGINALLY UNSTABLE AIR MASS WILL LIKELY YIELD SCATTERED THUNDERSTORMS OVER A LARGE AREA THIS AFTERNOON. ...TX/LA/SRN MS... SURFACE COLD FRONT CONTINUES TO SURGE SOUTHWARD ACROSS CENTRAL TX THIS MORNING...WHILE REMNANT OUTFLOW BOUNDARY SAGS SOUTHWARD INTO NORTHERN LA. MORNING VISIBLE SATELLITE IMAGERY SUGGESTS THAT MODERATE DAYTIME HEATING WILL OCCUR ALONG AND SOUTH OF BOUNDARIES IN REGION OF NEAR 70F SURFACE DEWPOINTS. AFTERNOON MLCAPE VALUES WILL LIKELY EXCEED 2500 J/KG ACROSS THIS REGION. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG BOUNDARIES FROM CENTRAL TX INTO NORTHERN LA DURING THE MID/LATE AFTERNOON. THIS ACTIVITY WILL POSE A THREAT OF LARGE HAIL AND DAMAGING WINDS. INCREASING DEEP LAYER VERTICAL SHEAR PROFILES THROUGH THE DAY MAY ALSO SUPPORT ISOLATED SUPERCELL STRUCTURES CAPABLE OF VERY LARGE HAIL. REFER TO MCD NUMBER 651 FOR SHORT TERM DETAILS OF THIS AREA. ...ERN AR/WRN TN/WRN KY/NRN MS... WIDESPREAD MID/HIGH CLOUDS PERSIST THIS MORNING OVER MUCH OF AR INTO WRN TN/KY AND NORTHERN MS. THESE CLOUDS ARE REMNANTS OF OVERNIGHT MCS WHICH HAS DIMINISHED. RELATIVELY STRONG HEATING WILL BE POSSIBLE ACROSS THIS REGION THIS AFTERNOON...ALLOWING AIR MASS TO DESTABILIZE WITH MLCAPE VALUES UP TO 2000 J/KG EXPECTED. CONSIDERABLE UNCERTAINTY EXISTS REGARDING FOCUS FOR INITIATION. HOWEVER...PARAMETERS SUGGEST A THREAT OF ISOLATED SEVERE STORMS WITH HAIL AND DAMAGING WINDS IN THIS REGION IF CONVECTION CAN DEVELOP. ...CENTRAL/EASTERN KY/TN INTO CENTRAL APPALACHIANS... MCV FROM OVERNIGHT THUNDERSTORMS IS NOW OVER WESTERN KY. THIS FEATURE WILL TRACK EASTWARD ALONG SURFACE BAROCLINIC ZONE...POSSIBLY AIDING THE DEVELOPMENT OF SCATTERED THUNDERSTORMS THIS AFTERNOON. STRONG HEATING IN THIS REGION ALONG WITH SUFFICIENT FLOW ALOFT WILL SUPPORT A RISK OF STRONG TO ISOLATED SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. REFER TO MCD NUMBER 650 FOR FURTHER DETAILS. ...VA/NC... STRONG DAYTIME HEATING WILL OCCUR THROUGHOUT THIS REGION TODAY...AS DEWPOINTS REMAIN IN THE 50S. MODEL FORECAST SOUNDINGS SHOW MLCAPE VALUES OF 500-1500 J/KG WITH RELATIVELY STRONG WESTERLY FLOW ALOFT. VERTICAL SHEAR PROFILES SUPPORT A RISK OF ORGANIZED/ISOLATED SEVERE STORMS FROM SOUTHERN VA INTO NC...BUT WEAK CAPE VALUES ARE A MITIGATING FACTOR. DAMAGING WINDS APPEAR TO BE THE MAIN THREAT WITH MORE SUSTAINED CELLS. ..HART/GRAMS.. 04/25/2006  From swody1 at goshenarc.org Tue Apr 25 20:11:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 16:11:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 252007 SWODY1 SPC AC 252005 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CDT TUE APR 25 2006 VALID 252000Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS VALLEY INTO SRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN MO...ERN AR...WRN TN AND WRN KY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF ERN TN...ERN KY...WV...VA AND NC... ...LOWER MS VALLEY... CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP THE REMAINDER OF THIS AFTERNOON ALONG AND S OF A CONVECTIVE OUTFLOW BOUNDARY FROM CNTRL AND SRN LA THROUGH PARTS OF SRN MS AND SRN AL. THE ATMOSPHERE IS MODERATELY UNSTABLE IN THIS REGION...BUT MODEST VERTICAL SHEAR PROFILES ARE GENERALLY SUPPORTIVE OF MULTICELL STORMS. ISOLATED DAMAGING WIND GUSTS AND HAIL MAY ACCOMPANY THE STRONGER ACTIVITY THROUGH EARLY EVENING. ...SRN MO...NERN AR...THROUGH WRN TN AND WRN KY... A COLD FRONT EXTENDS FROM THE OH VALLEY SWWD THROUGH SERN MO...AND WRN AR. THE ATMOSPHERE IS RECOVERING IN PRE-FRONTAL WARM SECTOR IN WAKE OF EARLIER CONVECTION WHERE TEMPERATURES ARE RISING THROUGH THE 70S AND DEWPOINTS ARE IN THE LOWER 60S. LATEST OBJECTIVE ANALYSIS SHOWS AROUND 1000 J/KG OF MUCAPE. CONVERGENCE AND BOUNDARY LAYER FLOW ALONG THE LEADING EDGE OF THE FRONT IS RATHER WEAK...AND RECENT STORMS HAVE BEEN INCREASING IN POST FRONTAL REGION WHERE DEEPER LAYER ASCENT IS OCCURRING. STORMS ARE ELEVATED OVER SWRN MO. HOWEVER...A MID LEVEL JET SPREADING EWD THROUGH SRN PERIPHERY OF SHORTWAVE TROUGH OVER KS IS CONTRIBUTING TO EFFECTIVE SHEAR SUFFICIENT FOR STORMS TO TAKE ON SUPERCELL STRUCTURES WITH ISOLATED HAIL THE MAIN THREATS. STORMS MAY INCREASE IN COVERAGE DURING THE AFTERNOON ACROSS SERN MO AND NERN AR AND SPREAD EWD INTO WRN TN AND WRN KY THIS EVENING AS DEEP LAYER ASCENT INCREASES DOWNSTREAM FROM EWD ADVANCING SHORTWAVE TROUGH. A FEW STORMS MAY DEVELOP CLOSER TO THE SURFACE FRONT WHERE THE ATMOSPHERE CONTINUES TO DESTABILIZE. ISOLATED HAIL AND STRONG WIND GUSTS WILL BE THE PRIMARY THREATS. ...S TX... THE CAP CONTINUES TO WEAKEN WITHIN PRE-FRONTAL WARM SECTOR ACROSS S TX WHERE THE ATMOSPHERE HAS BECOME MODERATELY UNSTABLE WITH MLCAPE AROUND 2500 J/KG. STORMS ARE EXPECTED TO DEVELOP IN VICINITY OF THE FRONT WITHIN THE NEXT COUPLE HOURS OR SO AND SUBSEQUENTLY SPREAD SEWD. DEEP LAYER VERTICAL SHEAR FROM 35 TO 40 KT IS SUFFICIENT FOR SOME STORMS TO TAKE ON SUPERCELL STRUCTURES. THE STRONG INSTABILITY...STEEP MID LEVEL LAPSE RATES AND POTENTIAL FOR UPDRAFT ROTATION WILL SUPPORT THE THREAT OF VERY LARGE HAIL. SOME STORMS MAY EVENTUALLY MERGE INTO CLUSTERS WITH AN INCREASING THREAT FOR DAMAGING WIND GUSTS. ...ERN KY THROUGH WV...VA AND THE CAROLINAS... CONVECTION IS EXPECTED TO CONTINUE DEVELOPING DOWNSTREAM FROM A COUPLE OF MID LEVEL VORTICITY MAXIMA MOVING EWD THROUGH THE TN AND OH VALLEYS. THE DOWNSTREAM ATMOSPHERE IS ONLY MARGINALLY UNSTABLE OWING TO LIMITED LOW LEVEL MOISTURE AND MODEST MID LEVEL LAPSE RATES. THE MARGINAL INSTABILITY WILL CONTINUE TO BE THE PRIMARY LIMITING FACTOR. HOWEVER...SURFACE HEATING HAS CONTRIBUTED TO 20-30C TEMPERATURE-DEWPOINTS SPREADS AND STEEP LOW LEVEL LAPSE RATES. PRIMARY THREAT APPEARS TO BE ISOLATED STRONG TO DAMAGING WIND GUSTS WITH CONVECTIVE LINES OR CLUSTERS AS ACTIVITY SPREADS EWD THE REMAINDER OF THIS AFTERNOON AND EVENING. ..DIAL.. 04/25/2006  From swody1 at goshenarc.org Wed Apr 26 01:01:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 25 Apr 2006 21:01:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260057 SWODY1 SPC AC 260056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT TUE APR 25 2006 VALID 260100Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GULF COASTAL AREAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NC...VA AND FAR WRN TN... ...TX COASTAL PLAINS... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SHORTWAVE TROUGH OVER SOUTH TX WHERE AN MCS IS DEVELOPING ATTM. THE SHORTWAVE TROUGH IS ASSOCIATED WITH THE NOSE OF A SUBTROPICAL MID-LEVEL JET PUNCHING INTO THE REGION FROM THE WEST SOUTHWEST. THIS IS CREATING STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH MODERATE TO STRONG INSTABILITY WILL CONTINUE TO BE FAVORABLE FOR SUPERCELLS. THE LATEST CRP SOUNDING SHOWS MLCAPE VALUES AROUND 3500 J/KG WITH MID-LEVEL LAPSE RATES EXCEEDING 7.5 C/KM SUGGESTING A POTENTIAL FOR VERY LARGE HAIL WILL CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH SUPERCELLS MAY PERSIST THROUGH MUCH OF THE EVENING...A GRADUAL TRANSITION TOWARD A LINEAR CONVECTIVE STRUCTURE MAY OCCUR. THE STRONGER SUPERCELLS MAY ALSO HAVE AN ISOLATED TORNADO/WIND DAMAGE THREAT. AS STORMS MERGE...THE WIND DAMAGE THREAT MAY BECOME LOCALLY ENHANCED WITH BOW ECHOES THAT DEVELOP. BY LATE THIS EVENING...THE SEVERE THREAT WITH THE MCS SHOULD BEGIN TO DIMINISH AS THE SHORTWAVE TROUGH MOVES EWD AND INSTABILITY DECREASES. ...MID-MS VALLEY... WATER VAPOR IMAGERY CURRENTLY SHOWS WLY FLOW ALOFT WITH A DRY SLOT MOVING ACROSS WRN MO AND NRN AR. A COMPLEX OF STORMS IS ONGOING IN NERN AR AND WRN TN NEAR A COLD FRONT AND INVERTED SFC TROUGH. A SMALL POCKET OF MODERATE INSTABILITY EXISTS JUST SOUTH OF THE FRONT WHERE SFC DEWPOINTS ARE IN THE LOWER TO MID 60S F. REGIONAL OOZ SOUNDINGS SHOW STRONG VERTICAL SHEAR PROFILES WHICH COMBINED WITH THE INSTABILITY WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. A WIND DAMAGE THREAT MAY ALSO EXIST ESPECIALLY ACROSS WRN TN WHERE LOW-LEVEL LAPSE RATES ARE A BIT STEEPER THAN AREA FURTHER WEST. THE SMALL CLUSTER OF STORMS MAY PERSIST THROUGH LATE EVENING...BUT THE SEVERE THREAT SHOULD GRADUALLY DECREASE AS INSTABILITY DIMINISHES ACROSS THE REGION. ...SRN VA/NC AND FAR WRN TX... STRONG WLY MID-LEVEL FLOW WAS IN PLACE ACROSS THE CAROLINAS WITH A COLD FRONT MOVING SWD ACROSS THE CNTRL APPALACHIAN MTNS. AHEAD OF THE FRONT...SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS ERN SC...CNTRL NC INTO SRN VA WITH SFC DEWPOINTS IN THE 60 TO 65 F RANGE. THIS IS RESULTING IN A POCKET OF MODERATE INSTABILITY WHICH COMBINED WITH THE STRONG VERTICAL SHEAR SHOWN ON THE GSO 00Z SOUNDING WILL BE SUFFICIENT FOR SEVERE STORMS. LAPSE RATES ARE STEEP ESPECIALLY AT LOW-LEVELS AND THIS WILL BE FAVORABLE FOR ISOLATED WIND DAMAGE AND HAIL WITH THE STRONGER CELLS. ..BROYLES.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 05:49:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 01:49:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260545 SWODY1 SPC AC 260543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT WED APR 26 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN SC...GA...SRN AL AND NRN FL... ...GULF COAST STATES... AT UPPER LEVELS...A TROUGH WILL DRIFT ESEWD INTO THE MS VALLEY AND OH VALLEYS TODAY AS A SFC LOW AND COLD FRONT MOVE EWD ACROSS MS...AL AND GA. MODEL FORECASTS ARE IN GENERAL AGREEMENT WITH A LARGE MCS ONGOING ACROSS SRN LA...SRN MS AND POSSIBLY AS FAR EAST AS SRN AL AT THE BEGINNING OF THE PERIOD. SFC HEATING SHOULD BE MAXIMIZED BY AFTERNOON EAST OF THE MCS ACROSS THE FL PANHANDLE AND SRN GA WITH POCKETS OF MODERATE INSTABILITY DEVELOPING BY MIDDAY. THIS MAY HELP TO REINTENSIFY STORMS ASSOCIATED WITH THE MCS IN THE EARLY AFTERNOON. OTHER STORMS SHOULD ALSO DEVELOP AHEAD OF THE MCS IN GA/NRN FL AND FURTHER NORTHWEST NEAR THE SFC BOUNDARY IN CNTRL AL. FORECAST SOUNDINGS ACROSS THE REGION TODAY GRADUALLY INCREASE VERTICAL SHEAR PROFILES AS A 50 KT MID-LEVEL JET ASSOCIATED WITH THE TROUGH SHIFTS SEWD. WITH MID 60S F SFC DEWPOINTS IN THE WARM SECTOR...THE STRENGTHENING SHEAR SHOULD MAKE ISOLATED SEVERE STORMS INCREASINGLY LIKELY IN THE AFTERNOON. IF MODERATE INSTABILITY DEVELOPS IN THE WARM SECTOR...SUPERCELLS WILL BE POSSIBLE BUT MULTICELL STORMS SHOULD ALSO HAVE SEVERE POTENTIAL. ALTHOUGH LAPSE RATES ARE NOT FORECAST TO BE THAT STEEP...THE UNDIRECTIONAL SHEAR PROFILES MAY SUPPORT ISOLATED WIND DAMAGE. HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER STORMS ESPECIALLY IN AREAS WITH LOCALLY MAXIMIZED INSTABILITY. THE SEVERE THREAT SHOULD BE CONCENTRATED NEAR OR JUST AFTER PEAK HEATING IN THE LATE AFTERNOON AND EARLY EVENING. ...CALIFORNIA... AN UPPER LOW JUST OFF THE SRN CA COAST IS FORECAST TO MOVE SEWD TODAY. NORTH OF THE UPPER-LOW...ELY FLOW WILL BE IN PLACE ACROSS THE SACRAMENTO VALLEY WHICH WILL ALLOW STORMS THAT INITIATE IN THE SIERRAS TO DRIFT WWD INTO THE VALLEY AREAS DURING THE AFTERNOON. AFTERNOON FORECAST SOUNDINGS ACROSS THE SACRAMENTO VALLEY SHOW SUFFICIENT INSTABILITY/SHEAR PROFILES AND STEEP ENOUGH LAPSE RATES FOR MARGINALLY SEVERE HAIL STORMS. DUE TO WIDESPREAD LARGE-SCALE ASCENT ON THE NORTH SIDE OF THE UPPER LOW...THE HAIL THREAT MAY PERSIST INTO THE EARLY EVENING BEFORE GRADUALLY DIMINISHING DUE TO THE WEAKENING INSTABILITY. ..BROYLES/CROSBIE.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 12:58:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 08:58:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261254 SWODY1 SPC AC 261253 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 AM CDT WED APR 26 2006 VALID 261300Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM SE MS/LA TO THE SC/GA/NE FL COAST.... ...SYNOPSIS... THE MID LEVEL SHORTWAVE TROUGH OVER MO THIS MORNING WILL MOVE SEWD AROUND THE SRN PERIPHERY OF A BROAD TROUGH OVER THE NE STATES...AND WILL REACH THE SRN APPALACHIANS BY LATE TONIGHT. AT THE SURFACE...A WEAK WAVE INVOF N GA WILL DEVELOP EWD ALONG A BAROCLINIC ZONE TO SC LATER TODAY...AS A COLD FRONT MOVES SEWD ACROSS THE GULF COAST STATES. ...SE STATES TODAY... THE SURFACE PATTERN IN THE WARM SECTOR HAS BEEN COMPLICATED BY MULTIPLE CONVECTIVE OUTFLOWS THE PAST DAY OR SO...WITH CONVECTION ONGOING ACROSS NRN AL AND FROM SRN LA TO SW AL. IT APPEARS THAT THE MORE UNDISTURBED AIR MASS WILL RESIDE ACROSS THE FL PANHANDLE TO SC IN ADVANCE OF THE MORNING STORMS...AND IN A BAND FROM ERN MS/CENTRAL AL AND CENTRAL/N GA THAT HAS NOT BEEN OVERTURNED BY PREVIOUS CONVECTION. GIVEN THE ONGOING STORMS AND THE POSSIBILITY FOR ADDITIONAL DEVELOPMENT ALONG THE COLD FRONT AND ALONG THE PATH OF THE SURFACE WAVE...SEVERAL THUNDERSTORM CLUSTERS CAN BE EXPECTED ACROSS THE SLIGHT RISK AREA THROUGH LATE EVENING. RESIDUAL CLOUDINESS FROM OVERNIGHT CONVECTION MAY LIMIT SURFACE HEATING SOME IN THE WARM SECTOR. ALSO...MID LEVEL LAPSE RATES WILL LIKELY DIMINISH WITH TIME AS A RESULT OF CONVECTION AND TRAJECTORIES NO LONGER EMANATING FROM THE EML SOURCE REGION TO THE W. STILL...BOUNDARY LAYER DEWPOINTS OF 65-70 F AND DAYTIME TEMPERATURES OF 75-85 F WILL SUPPORT MLCAPE VALUES IN THE RANGE OF 500-1000 J/KG. WIND PROFILES IN THE WARM SECTOR SHOULD BE LARGELY UNIDIRECTIONAL WITH SOME SPEED INCREASE ALOFT...WHICH IN COMBINATION WITH THE WEAK-MODERATE INSTABILITY MAY SUPPORT A FEW STORMS WITH LARGE HAIL AND DAMAGING WINDS. ..THOMPSON/CROSBIE.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 16:20:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 12:20:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261615 SWODY1 SPC AC 261613 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CDT WED APR 26 2006 VALID 261630Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE SOUTHEAST STATES... BROAD UPPER TROUGH OVER THE MID MS VALLEY WILL TRACK EASTWARD TODAY INTO KY/TN. A LARGE AREA OF STRONGER MID LEVEL WESTERLY FLOW /40-50 KNOTS AT 500MB/ IS PRESENT TO THE SOUTHEAST OF THE TROUGH...AND WILL OVERSPREAD MUCH OF THE SOUTHEASTERN U.S. THIS AFTERNOON AND EVENING. SOUTHWESTERLY LOW LEVEL WINDS ARE ALSO FORECAST TO STRENGTHEN ACROSS GA/SC BY 00Z AS WEAK CYCLOGENESIS OCCURS OVER SC. THESE TRENDS WILL RESULT IN INCREASINGLY FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/SEVERE STORMS ACROSS MUCH OF AL/GA/SC AND NORTH FL. ...SC... MORNING SURFACE ANALYSIS SHOWS WEAK LOW OVER UPSTATE SC...WITH FRONT EXTENDING EASTWARD TO SOUTH OF MYR. STRONG DAYTIME HEATING IS OCCURRING ALONG AND SOUTH OF BOUNDARY WITH TEMPERATURES EXPECTED TO RISE INTO THE 80S. AFTERNOON SBCAPE VALUES OVER 2500 J/KG...ALONG WITH CONVERGENCE ALONG FRONT...WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS. DESPITE RATHER WEAK LOW LEVEL FLOW IN THIS REGION...DEEP LAYER SHEAR WILL SUPPORT ISOLATED SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. BRIEF TORNADOES COULD ALSO OCCUR NEAR BOUNDARIES. ...ERN GA/NRN FL... MORE ISOLATED THUNDERSTORM DEVELOPMENT IS EXPECTED SOUTHWARD TO EASTERN GA AND POSSIBLY NORTHERN FL AS CONVECTIVE TEMPERATURE IS REACHED /LOWER 80S/ AND REMNANT OUTFLOW BOUNDARIES MOVE INTO REGION. STRONGER CELLS IN THIS REGION WILL POSE A THREAT OF DAMAGING WINDS AND HAIL. ...AL... PRIMARY SURFACE COLD FRONT EXTENDS FROM NORTHEAST MS INTO EASTERN TN. LOW LEVEL MOISTURE REMAINS IN PLACE AHEAD OF FRONT WITH DEWPOINTS IN THE 60S ACROSS ALL OF AL. IF BREAKS IN THE CLOUDS ALLOW AFTERNOON HEATING...SUFFICIENT DESTABILIZATION COULD OCCUR TO SUPPORT A RISK OF ISOLATED SEVERE STORMS. CURRENT VISIBLE SATELLITE IMAGERY SUGGESTS THIS THREAT IS RATHER LOW. ..HART/GRAMS.. 04/26/2006  From swody1 at goshenarc.org Wed Apr 26 19:47:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 26 Apr 2006 15:47:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261944 SWODY1 SPC AC 261942 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0242 PM CDT WED APR 26 2006 VALID 262000Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE SERN U.S.... ...SERN STATES... EARLY THIS AFTERNOON A BACK DOOR COLD FRONT HAS SETTLED SWD ACROSS CNTRL NC. FARTHER W A COLD FRONT EXTENDS FROM SERN TN SWWD THROUGH NWRN AL AND INTO SERN MS. NUMEROUS STORMS ARE DEVELOPING IN THE WEAKLY CAPPED WARM SECTOR BETWEEN THESE TWO BOUNDARIES FROM AL EWD THROUGH GA AND SC AS WELL AS NRN FL. RECENT OBJECTIVE ANALYSIS DATA SHOW THE ATMOSPHERE IS MOST UNSTABLE FROM ERN GA INTO SC WHERE STRONGER SURFACE HEATING HAS CONTRIBUTED TO MLCAPE AROUND 2000 J/KG. STRONGEST STORMS CONTINUE DEVELOPING IN VICINITY OF THE BACK DOOR FRONT ACROSS SC. VWP DATA SHOW RELATIVELY WEAK WLY FLOW THROUGH THE LOWEST 2 KM IN SC. HOWEVER...PRESENCE OF 50 KT MID LEVEL FLOW ON SERN PERIPHERY OF SHORTWAVE TROUGH MOVING EWD THROUGH THE TN VALLEY IS RESULTING IN DEEP LAYER SHEAR ON THE ORDER OF 45 KT...SUFFICIENT FOR SUPERCELL STRUCTURES. PRIMARY THREAT IS VERY LARGE HAIL AND DAMAGING WIND GUSTS WITH THESE STORMS. A BRIEF TORNADO OR TWO IS POSSIBLE...MAINLY IN NARROW ZONE ACROSS CNTRL SC AS STORMS CROSS THE BOUNDARY BEFORE BECOMING ELEVATED AND WEAKENING AS THEY MOVE DEEPER INTO THE COOL SIDE OF THE FRONT. ELSEWHERE...AN MCS CONTINUES TO ADVANCE EWD THROUGH SRN GA WHERE THE WLY LOW LEVEL JET HAS BEEN STRENGTHENING DURING THE PAST COUPLE HOURS. DAMAGING WIND AND HAIL MAY ACCOMPANY THIS ACTIVITY AS IT CONTINUES EWD THROUGH SRN GA...REACHING SRN SC LATER THIS AFTERNOON. OTHERWISE...SEVERE THREAT FARTHER W ACROSS THE REMAINDER OF AL...NRN GA AND SERN MS AHEAD OF THE FRONT APPEARS MORE MARGINAL GIVEN MUCH OF THIS AREA HAS BEEN SOMEWHAT STABILIZED FROM EARLIER CONVECTION. ..DIAL.. 04/26/2006  From SwoDy1 at goshenarc.org Fri Apr 28 01:50:26 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 27 Apr 2006 21:50:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280148 SWODY1 SPC AC 280146 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0846 PM CDT THU APR 27 2006 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED FOR POINTS FILE ...CNTRL/SRN PLAINS... RESIDUAL LARGE SCALE RIDGING AND HIGH CLOUDS MAINTAINED A FAIRLY UNFAVORABLE ENVIRONMENT FOR TSTMS OVER THE MOUNTAINS OF SWRN TX DURING THE AFTN. 18...21 AND 00Z MIDLAND SOUNDINGS ALSO SHOWED SIGNIFICANT INHIBITION ON THE PLAINS TO SUPPRESS TSTMS. THOUGH THE LARGE SCALE IS EXPECTED TO BECOME MORE CYCLONIC ALOFT THROUGH THE NIGHT...IT IS NOT CLEAR WHETHER WIDESPREAD ORGANIZED SEVERE STORMS WILL DEVELOP. SLIGHTLY HIGHER PROBABILITIES FOR TSTMS WILL EXIST ACROSS THE BIG BEND REGION AND INTO WRN PARTS OF SCNTRL TX AS ELEVATED BANDS OF STORMS BECOME BETTER DEFINED WITHIN THE WARM CONVEYOR BELT. HERE...ISOLD HAIL MAY OCCUR GIVEN STEEP LAPSE RATES. FARTHER N...COMBINATION OF A MORE FAVORABLE DIFFLUENT/DIVERGENT UPPER FLOW REGIME DOWNSTREAM FROM THE DESERT SW UPPER LOW...A STRONGER COMPONENT OF MOISTENING UPSLOPE FLOW AND HEATING CONTRIBUTED TO MORE TSTM COVERAGE THIS AFTN. VERTICAL SHEAR HAS BEEN SUPPORTIVE OF STRONG-SEVERE STORMS/SUPERCELLS OVER MAINLY ECNTRL/NERN NM. THESE STORMS MAY PRODUCE ISOLD LARGE HAIL OR A DAMAGING WIND GUST THROUGH MID-EVENING. THE NERN NM ACTIVITY IS LIKELY TO EXPAND ENEWD ACROSS THE CNTRL PLAINS ALONG/N OF THE SEWD MOVING LEE-TROUGH/COLD FRONT OVERNIGHT. STEEP LAPSE RATE ENVIRONMENT AND FAVORABLE VERTICAL SHEAR MAY BE SUFFICIENT FOR STRONG TSTMS WITH PERHAPS ISOLD HAIL/GUSTY WINDS. ..RACY.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 05:54:57 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 01:54:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280553 SWODY1 SPC AC 280551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT FRI APR 28 2006 VALID 281200Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF WCNTRL/CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SRN PLAINS... ...SYNOPSIS... A HIGHLY AMPLIFIED UPPER FLOW REGIME WILL CONTINUE ON FRI. UPPER LOW NOW MOVING ACROSS THE DESERT SW WILL ACCELERATE EWD THROUGH THE SRN ROCKIES EARLY TODAY AS IT BEGINS TO PHASE WITH A NRN STREAM IMPULSE DROPPING SWD THROUGH THE PLAINS. THE SRN DISTURBANCE AND ATTENDANT 60-METER/12-HR HEIGHT FALLS WILL SPREAD EWD ACROSS THE SRN PLAINS FRI AFTN/NIGHT. AT THE SFC...THE WARM FRONT SITUATED ACROSS SRN TX WILL REDEVELOP NWD THROUGH WRN/CNTRL TX BY FRI AFTN. A LEE-TROUGH/DRYLINE WILL BECOME ESTABLISHED FROM THE SRN TX PNHDL SWD INTO SWRN TX BY FRI MID-AFTN. MEANWHILE...A COLD FRONT...ASSOCIATED WITH THE NRN STREAM TROUGH...WILL MOVE SEWD ACROSS THE ERN PLAINS AND SWD THROUGH THE TX PNHDL THROUGH FRI NIGHT. ...SRN PLAINS... THERE WILL LIKELY BE WIDESPREAD CLOUDS/CONVECTION ONGOING EARLY FRI MORNING ACROSS PARTS OF OK AND CNTRL/ERN TX...ALONG THE NOSE OF A LLJ. THIS WILL ACT TO REINFORCE THE NW-SE ORIENTED FRONT ACROSS CNTRL TX THROUGH FRI EVENING. LATEST MODELS SUGGEST THAT THE WARM CONVEYOR WILL BEGIN TO SHIFT EWD DURING THE AFTN. THIS SHOULD ALLOW STRONG HEATING TO OCCUR ACROSS SWRN/WCNTRL TX NWD INTO THE ERN TX PNHDL/SWRN OK FRI AFTN. CONCURRENTLY...LOW-LEVEL MOISTURE...NOW IMPROVING ACROSS DEEP S TX NWWD INTO THE TRANSPECOS REGION...WILL ADVECT NWWD AS THE SELY FLOW ACCELERATES AHEAD OF THE APPROACHING UPPER LOW. BY PEAK HEATING...60S BOUNDARY LAYER DEW POINTS SHOULD EXIST ALONG/E OF THE DRYLINE AND SOUTH OF THE WARM FRONT. STEEPENING MID-LEVEL LAPSE RATES...OWING TO LARGE SCALE ASCENT/MOISTENING AND MID-LEVEL COLD ADVECTION...SPREADING EWD ATOP THE LOW-LEVEL THETA-E AXIS WILL ENCOURAGE TSTMS TO INITIATE ALONG THE DRYLINE/HIGHER TERRAIN BY MID-AFTN FROM THE ERN TX PNHDL SWD INTO SWRN TX. GIVEN 70+ KTS OF VERTICAL SHEAR AND MAGNITUDE OF INSTABILITY...TSTMS WILL LIKELY GROW INTO SUPERCELLS WITH VERY LARGE HAIL...PARTICULARLY OVER WCNTRL/CNTRL TX SWD TOWARD THE RIO GRANDE. BACKED LOW-LEVEL FLOW VCNTY OF THE RETREATING WARM FRONT WILL ALSO BE FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THE INFLUX OF A MOIST BOUNDARY LAYER. THE MID-LEVEL FLOW WILL GRADUALLY BACK DURING THE EVENING AS THE UPPER LOW MOVES EWD. THUS...TSTMS WILL TEND TO EVOLVE INTO A LINEAR MCS AFTER DARK...THEN MOVE EWD ACROSS OK...CNTRL/ERN TX OVERNIGHT WITH ATTENDANT HAIL/HIGH WINDS. STRONGER ACTIVITY WILL LIKELY FAVOR THE SRN EDGE OF THE MCS ACROSS SCNTRL TX WHERE THE BETTER QUALITY MOISTURE/INSTABILITY WILL RESIDE S OF THE WARM FRONT. ...NRN PLAINS... STEEP LOW/MID-LEVEL LAPSE RATES BENEATH THE WEAKENING NRN STREAM IMPULSE WILL PERSIST ACROSS THE NRN PLAINS FRI. A NARROW AXIS OF BOUNDARY LAYER DEW POINTS AOA 45 DEG F BENEATH H5 TEMPERATURES AROUND MINUS 20 DEG C WILL BE FAVORABLE FOR SCT STRONG TSTMS. THOUGH THE VERTICAL SHEAR WILL BE WEAK...MAGNITUDE OF THE LAPSE RATES WILL PROBABLY FOSTER LARGE HAIL PRODUCTION WITH ISOLD STRONGER UPDRAFTS. ..RACY/BRIGHT/CROSBIE.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 12:43:24 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 08:43:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281241 SWODY1 SPC AC 281240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT FRI APR 28 2006 VALID 281300Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF W CNTRL AND CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE PART OF THE SRN PLNS... ...SYNOPSIS... THE MAIN BELT OF THE WLYS WILL REMAIN WELL TO THE N ACROSS CNTRL CANADA THIS PERIOD. PATTERN WILL...NEVERTHELESS...BECOME MORE AMPLIFIED OVER THE LWR 48 AS SE AZ UPR LOW CONTINUES E AND PHASES WITH NRN STREAM TROUGH NOW OVER THE NRN HI PLNS. THE COMBINED SYSTEMS SHOULD REACH THE CNTRL PLNS BY 12Z SATURDAY AS ASSOCIATED 60-90M HEIGHT FALL CENTER ADVANCES FROM W TX THIS AFTERNOON...AND INTO CNTRL PARTS OF OK/KS EARLY SATURDAY. AT LWR LEVELS..COLD FRONT NOW IN THE CNTRL HI PLNS EXPECTED TO CONTINUE SURGING S INTO NE NM AND THE WRN/NRN OK/TX PANHANDLES THROUGH THE AFTERNOON...BEFORE TURNING MORE SE TOWARD THE I-35 CORRIDOR TONIGHT/EARLY SATURDAY. S OF THIS FRONT...DRY LINE/ PACIFIC COLD FRONT NOW IN NM SHOULD MIX E INTO W TX DURING THE AFTERNOON. AHEAD OF THIS FEATURE...DIFFUSE WARM FRONT NOW EXTENDING FROM NEAR LBB THROUGH SJT TO VCT SHOULD REDEVELOP NE INTO CNTRL TX. ...SRN PLNS... STRENGTHENING WARM ADVECTION/UPR LEVEL DIVERGENCE AHEAD OF AZ UPR LOW EXPECTED TO RESULT IN INCREASING COVERAGE OF ELEVATED TSTMS THROUGH THE DAY FROM MUCH OF KS/SRN NEB S/SE INTO CNTRL/ERN OK AND NE TX. THIS ACTIVITY SHOULD LIMIT NWD/EWD ADVANCE OF BOUNDARY LAYER MOISTURE RETURN ACROSS MUCH OF OK AND NE TX. GIVEN EXISTING LOW LEVEL MOISTURE AXIS NOW EXTENDING FROM S CNTRL TX NWWD TO NEAR MAF/LBB...AND CURRENT SATELLITE TRENDS SUGGESTING THAT MID/UPR LEVEL CLOUDS WILL CLEAR SLOWLY SE ACROSS THE REGION THROUGH THE DAY...EXPECT THAT SURFACE-BASED INSTABILITY AXIS BY MID AFTERNOON WILL EXTEND FROM THE ERN TX PANHANDLE/FAR WRN OK SWD IN A WIDENING BAND ACROSS W CNTRL TX INTO THE TX HILL COUNTRY/TX BIG BEND. MUCAPE LIKELY WILL RANGE FROM 1000-1500 J/KG IN THE NORTH TO LOCALLY ABOVE 2000 J/KG NEAR THE RIO GRANDE...WHERE DEWPOINTS SHOULD REMAIN IN THE MID TO UPR 60S. CONVERGENCE AND HEATING SHOULD INITIATE STORMS ALONG EWD-MOVING DRY LINE/PACIFIC COLD FRONT...AND ALONG SWD-MOVING COLD FRONT...FROM THE SRN/ERN PANHANDLE REGION S ACROSS THE LOW ROLLING PLAINS/WRN HILL COUNTRY BY MID TO LATE AFTERNOON. ONE OR TWO STORMS MAY ALSO FORM IN ZONE OF CONVERGENT UPSLOPE FLOW JUST W OF THE LWR PECOS. PRESENCE OF NRN STREAM IMPULSE WILL KEEP A BRANCH OF THE LLJ AIMED N TOWARD THE LWR MO VLY TODAY. THIS WILL TEND TO WEAKEN AND VEER LOW LVL WIND PROFILES SOMEWHAT OVER THE SRN PLNS. NEVERTHELESS... GIVEN STRENGTHENING MID/UPR LEVEL WINDS DOWNSTREAM FROM AZ SYSTEM /500 MB SWLY FLOW EXPECTED TO BE AOA 70 KTS BY MID AFTERNOON ACROSS CNTRL-SCNTRL TX/...AND DEGREE OF INSTABILITY/MOISTURE INFLOW...SETUP LIKELY WILL FOSTER SUPERCELLS WITH VERY LARGE HAIL/ HIGH WIND AND POSSIBLY A FEW TORNADOES...ESPECIALLY FROM E OF LBB SE INTO THE EDWARDS PLATEAU/BIG BEND. TORNADO POTENTIAL SHOULD BE GREATEST INVOF ANY WARM FRONTAL SEGMENTS...WHERE SELY LOW LEVEL FLOW MAY LOCALLY ENHANCE SRH. AS UPR SYSTEM CONTINUES EWD...STRENGTH/LINEAR NATURE OF LARGE SCALE FORCING...AND EXISTING WIND PROFILES...SUGGEST FAIRLY RAPID EVOLUTION TOWARD BROKEN LINE SEGMENTS WITH EMBEDDED SUPERCELLS. THIS ACTIVITY SHOULD FURTHER CONSOLIDATE INTO ONE OR TWO FAIRLY EXTENSIVE SQUALL LINES...WITH THE SYSTEMS MOVING GENERALLY E ACROSS THE REMAINDER OF CNTRL TX AND S CNTRL OK LATE THIS EVENING. INSTABILITY CONSIDERATIONS...AND EXPECTED STRENGTHENING OF LOW LEVEL WIND FIELD AS UPR SYSTEMS FINALLY PHASE OVER KS...SUGGEST THAT THE MCSS WILL CONTINUE TO POSE A THREAT FOR DAMAGING WIND/HAIL AND PERHAPS ISOLATED TORNADOES AS THEY CROSS THE TX CSTL PLN/NE TX BETWEEN 09 AND 12Z SATURDAY. ...NRN PLAINS... STEEP LOW/MID-LEVEL LAPSE RATE PLUME WILL PERSIST BENEATH WEAKENING NRN STREAM IMPULSE OVER THE NRN PLAINS TODAY. GIVEN SURFACE HEATING...NARROW AXIS OF BOUNDARY LAYER DEW POINTS AOA 45 DEG F BENEATH 500 MB TEMPERATURES AROUND MINUS 20 DEG C SHOULD SUPPORT SCTD STRONG TSTMS. VERTICAL SHEAR WILL BE WEAK...BUT SUFFICIENT INSTABILITY MAY DEVELOP TO FOSTER HAIL IN THE STRONGER UPDRAFTS. ..CORFIDI/CROSBIE.. 04/28/2006  From SwoDy1 at goshenarc.org Fri Apr 28 16:46:38 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 12:46:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281645 SWODY1 SPC AC 281643 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 AM CDT FRI APR 28 2006 VALID 281630Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF WRN...SWRN AND W CNTRL TX... ...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE SRN PLAINS... ...SRN PLAINS... A COLD FRONT EXTENDS FROM W CNTRL KS SWWD THROUGH THE OK AND TX PANHANDLES. A DRY LINE/PACIFIC FRONT EXTENDS FROM SWRN TX NEAR FORT STOCKTON NWD INTO THE WRN TX PANHANDLE WHERE IT INTERSECTS THE SEWD ADVANCING COLD FRONT. FARTHER S...A WARM FRONT EXTENDS ACROSS SRN TX FROM NEAR HOUSTON WWD INTO THE RIO GRANDE AREA. THE WARM FRONT SEPARATES RICH GULF MOISTURE WITH DEWPOINTS NEAR 70 FROM THE PARTIALLY MODIFIED GULF AIR WITH DEWPOINTS IN THE LOW TO MID 60S. WIDESPREAD CLOUDS PERSIST IN THE WARM SECTOR E OF THE DRYLINE. HOWEVER...CLOUDS ARE CLEARING OUT ACROSS W TX IN PROXIMITY TO MID/UPPER LEVEL DRY SLOT. THE ATMOSPHERE SHOULD CONTINUE TO DESTABILIZE FROM NEAR THE BIG BEND NWD INTO NWRN TX ALONG THE MOIST AXIS WITH MLCAPE FROM 1500 TO 2000 J/KG THIS AFTERNOON. INCREASING BOUNDARY LAYER CONVERGENCE AND WEAKENING CAP SHOULD CONTRIBUTE TO THUNDERSTORM INITIATION ACROSS W TX THIS AFTERNOON. ADDITIONAL STORMS WILL LIKELY DEVELOP ALONG SEWD ADVANCING FRONT FROM THE SRN TX PANHANDLE INTO SWRN OK. A MID LEVEL JET WILL ROTATE NEWD THROUGH WRN TX ALONG THE SERN PERIPHERY OF THE NM CUTOFF LOW AND WILL CONTRITE TO INCREASING LARGE SCALE ASCENT. THIS FEATURE WILL ALSO MAINTAIN VERTICAL SHEAR PROFILES SUPPORTIVE OF SUPERCELL STRUCTURES. VERY LARGE HAIL AND A FEW TORNADOES MAY ACCOMPANY THIS ACTIVITY AS IT SPREAD EWD THROUGH WRN TX AND INTO W CNTRL TX THIS AFTERNOON. ACTIVITY MAY EVENTUALLY EVOLVE INTO AN MCS AS IT DEVELOPS EWD OVERNIGHT WITH A CONTINUED THREAT FOR LARGE HAIL AND DAMAGING WIND. ISOLATED TORNADOES ALSO REMAIN POSSIBLE...ESPECIALLY WITH ANY DISCRETE ACTIVITY ON SRN END OF MCS. A STRONG LOW LEVEL JET WILL PERSIST ACROSS CNTRL TX AND MAINTAIN ISENTROPIC LIFT ALONG AND N OF E-W BOUNDARY ACROSS S CNTRL TX. ELEVATED STORMS ARE CURRENTLY DEVELOPING FROM S CNTRL THROUGH N TX WITHIN THIS WARM ADVECTION REGIME. AS LOW LEVEL DEWPOINTS CONTINUE TO DEVELOP NWD AND AS THE BOUNDARY LAYER WARMS...THERE IS POTENTIAL FOR SOME OF THESE STORMS TO BECOME CLOSER TO SURFACE BASED. LOW LEVEL HODOGRAPHS ARE ENHANCED BY VEERING BOUNDARY LAYER FLOW IN VICINITY OF THE WARM FRONT ACROSS S CNTRL TX...AND WOULD ENHANCE THE THREAT FOR ISOLATED TORNADOES IF STORMS MANAGE TO BECOME ROOTED NEAR THE SURFACE. FARTHER N ACROSS OK AND KS...STORMS WILL MOST LIKELY REMAIN ELEVATED GIVEN POTENTIAL FOR MORE WIDESPREAD CONVECTION FARTHER S WHICH SHOULD LIMIT DEGREE OF NWD MOISTURE RETURN AND SURFACE BASED DESTABILIZATION. AT THIS TIME...PRIMARY THREAT APPEARS TO BE LARGE HAIL. ...NRN PLAINS... STEEP MID LEVEL LAPSE RATES WILL SUPPORT A THREAT OF HAIL AS THE ATMOSPHERE DESTABILIZES AND STORMS DEVELOP IN VICINITY OF UPPER LOW THIS AFTERNOON. ..DIAL.. 04/28/2006  From SwoDy1 at goshenarc.org Sat Apr 29 01:04:35 2006 From: SwoDy1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 28 Apr 2006 21:04:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290102 SWODY1 SPC AC 290100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT FRI APR 28 2006 VALID 290100Z - 291200Z ...THERE IS A MDT RISK OF SVR TSTMS CNTRL TX AND SMALL PART OF SWRN OK... ...THERE IS A SLGT RISK OF SVR TSTMS SRN PLAINS... ...SRN PLAINS... EXTENSIVE AREA OF CONVECTION ONGOING OVER MUCH OF THE CENTRAL AND SOUTHERN PLAINS AS UPPER SYSTEM OVER SWRN NM ADVANCES INTO THE CNTRL CONUS. COLD FRONT HAS REACHED INTO WRN OK AND EXTENDS SWD THROUGH THE PANHANDLE OF TX...WITH THE DRYLINE EXTENDING SWD FROM SURFACE LOW INTO SWRN TX. AHEAD OF DRYLINE/SURFACE LOW A MODERATELY UNSTABLE WARM SECTOR /SBCAPE AOB 2500 J/KG/ IS IN PLACE THROUGHOUT CNTRL AND SRN TX. MID LEVEL JET OF 70 KTS IS ENHANCING THE VERTICAL SHEAR IN THE CENTRAL AND SRN PLAINS. 00 UTC SOUNDINGS SHOW IMPRESSIVE LOW/DEEP LAYER SHEAR...PARTICULARLY SOUTH OF THE RED RIVER WHERE SURFACE TO 6 KM AGL SHEAR EXCEEDS 60 TO 70 KTS AND 0-1 KM SRH IS AOB 300 M2/S2. AS STRONG FORCING CONTINUES TO ADVANCE EWD INTO THE PLAINS...EXPECT SURFACE BASED SUPERCELLS TO EVOLVE INTO MIXED LINEAR/DISCRETE MODES WITH CONVECTION CONTINUING THROUGH THE NIGHT. OVERNIGHT PRIND THAT FAIRLY EXTENSIVE SQUALL LINE MAY EVOLVE FROM CNTRL/SRN OK TO CNTRL/ERN TX. THE THREAT OF VERY LARGE HAIL AND DAMAGING WINDS WILL PERSIST...WITH THE GREATEST TORNADO THREAT ALONG AND SOUTH OF THE RED RIVER WHERE MAXIMUM INSTABILITY AND LOW LEVEL MOISTURE RESIDE. FARTHER NORTH ELEVATED CONVECTION WITH THE POTENTIAL FOR EMBEDDED SUPERCELLS WILL EXTEND NWD TO THE KS BORDER. BROAD AREA OF LARGE SCALE ASCENT WILL CONTINUE TO ENHANCE LLJ...SUPPORTING WIDESPREAD CONVECTION...HEAVY PRECIPITATION...AND ISOLATED THREAT OF LARGE HAIL. ..BRIGHT/RACY.. 04/29/2006