From swody1 at goshenarc.org Fri Sep 1 00:54:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 20:54:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010055 SWODY1 SPC AC 010053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT THU AUG 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS WITH ERNESTO... ...CENTRAL PLAINS... LINEAR MCS HAS EVOLVED OVER ERN CO...EXTENDING FROM MORGAN COUNTY TO LINCOLN COUNTY. THIS ACTIVITY IS SPREADING EWD AT ROUGHLY 25 KT...WITH SRN EXTENT MORE SUPERCELLULAR IN NATURE. IT APPEARS A WEAK MVC IS EVOLVING OVER NERN CO WHERE LARGER PRECIPITATION SHIELD CONTINUES TO EXPAND...ALONG WITH COLD POOL. DOWNSTREAM...00Z SOUNDING FROM DDC DEPICTS SIGNIFICANT LOW LEVEL WARM ADVECTION THROUGH 700MB...WITH SUBSTANTIAL VEERING WITH HEIGHT AND MODERATE INSTABILITY. ISOLATED THUNDERSTORMS HAVE RECENTLY DEVELOPED AHEAD OF MAIN MCS OVER PORTIONS OF WRN KS. ONE STORM OVER WICHITA COUNTY IS ORGANIZING ALONG A WELL DEFINED LOW LEVEL CONFLUENCE ZONE THAT STRETCHES FROM NWRN OK INTO ECNTRL CO. LATEST THINKING IS ISOLATED STORMS WILL CONTINUE TO EVOLVE WITHIN THIS FAVORED ZONE OF LOW LEVEL WARM ADVECTION...WELL AHEAD OF MCS. WITH TIME...SEWD MOVEMENT OF MCS WILL MERGE WITH THIS DOWNSTREAM CONVECTION BEFORE PROPAGATING INTO PORTIONS OF NWRN OK LATE TONIGHT. LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE WITH THESE CONVECTIVE CLUSTERS WELL INTO THE MORNING HOURS. ...ERNESTO... ERNESTO...LOCATED JUST SOUTH OF ILM...CONTINUES ITS NWD MOVEMENT TO TOWARD THE SRN NC COAST. WIDESPREAD PRECIPITATION HAS SPREAD WELL INLAND ACROSS MUCH OF NC WITH STRONGER UPDRAFTS LOCATED INVOF CIRCULATION CENTER. LOW LEVEL SHEAR PROFILES WILL INCREASE AS LOW MOVES INLAND OVER THE NEXT FEW HOURS. ALTHOUGH LIGHTNING REMAINS CONCENTRATED OVER THE GULF STREAM...ISOLATED BRIEF TORNADOES MAY YET DEVELOP WITHIN STRONGER CONVECTIVE BANDS. ..DARROW.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 05:59:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 01:59:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010559 SWODY1 SPC AC 010558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI SEP 01 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FOR ERNESTO ACROSS ERN NC AND SERN VA... ...CENTRAL PLAINS... CONVECTION WILL READILY DEVELOP AGAIN ACROSS THE CENTRAL HIGH PLAINS THIS AFTERNOON AHEAD OF MAIN FRONTAL SURGE. LATE EVENING MODEL GUIDANCE AND EARLY MORNING DIAGNOSTIC DATA SUGGEST SFC PRESSURES WILL CONTINUE TO RISE ACROSS THE NRN ROCKIES FORCING COLD FRONT INTO NERN CO BY 18Z. LATEST THINKING IS BOUNDARY LAYER LAPSE RATES WILL STEEPEN SUFFICIENTLY...GIVEN STRENGTHENING NELY UPSLOPE REGIME...FOR THUNDERSTORM DEVELOPMENT BY 20Z FROM THE WY/CO BORDER INTO SWRN NEB. THIS ACTIVITY SHOULD SPREAD SEWD WITHIN MODERATELY-STRONG SHEARED ENVIRONMENT...SFC-6KM BULK SHEAR ON THE ORDER OF 40KT. ALTHOUGH SUPERCELL STRUCTURES ARE POSSIBLE...IT APPEARS FORCING MAY FACILITATE STORM MERGERS AND POSSIBLE MCS EVOLUTION BY LATE AFTERNOON ACROSS ERN CO. THIS ACTIVITY SHOULD SPREAD SEWD ACROSS WRN KS INTO THE OK/TX PANHANDLES LATER IN THE EVENING. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY SEVERE THREATS. ...ERN NC/SERN VA... TROPICAL STORM ERNESTO WILL LIFT NWD ACROSS NC INTO SRN VA AND WEAKEN LATER THIS MORNING. BOUNDARY LAYER AIRMASS IS QUITE STABLE OVER VA THIS MORNING WHERE SFC DEW POINTS CONTINUE TO DROP WITH SUSTAINED NELY LOW LEVEL TRAJECTORIES FROM DOMINANT SFC RIDGE OVER SERN CANADA. TROPICAL WEDGE OVER ERN NC INTO SERN VA SHOULD PROVIDE SUFFICIENT INSTABILITY FOR CONVECTION AND THE THREAT FOR ISOLATED TORNADOES THIS MORNING. HOWEVER...STRONGER SHEAR WILL SPREAD ATOP STABLE BOUNDARY LAYER OVER THE MIDDLE ATLANTIC AND THE SEVERE THREAT WILL DECREASE THIS AFTERNOON. ..DARROW/BOTHWELL.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 12:33:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 08:33:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011232 SWODY1 SPC AC 011230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0730 AM CDT FRI SEP 01 2006 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS IN EXTREME NERN NC AND SERN VA... ...SYNOPSIS... T.S. ERNESTO IS FORECAST TO SHIFT NWD THROUGH THE PERIOD FROM NC INTO VA AND WEAKEN...THOUGH SYSTEM WILL RESULT IN STRONG ISENTROPIC LIFTING AND WIDESPREAD HEAVY RAINFALL ACROSS THE MID ATLANTIC STATES THROUGH TONIGHT. AN UPPER TROUGH IN THE NRN ROCKIES WILL SHIFT ESEWD INTO THE NRN/CENTRAL PLAINS LATER TODAY...PUSHING A COLD FRONT SEWD INTO THE CENTRAL PLAINS/ROCKIES THIS AFTERNOON. ...NERN NC/EXTREME SERN VA... THE CENTER OF THE ERNESTO APPEARED TO BE LOCATED NEAR RWI WITH A WARM FRONT EXTENDING NEWD FROM THIS SYSTEM TO NEAR THE VA/NC BORDER. WHILE MID 70 DEWPOINTS ARE PRESENT EAST OF THIS BOUNDARY ...INSTABILITY IS QUITE WEAK DUE TO THE MOIST ADIABATIC LAPSE RATES. VAD WIND PROFILES SHOW THE SHEAR REMAINS STRONG...ESPECIALLY IN THE LOWER LEVELS WITH THE 1 KM SHEAR RANGING FROM 30-50 KT. THE MAIN BAND OF CONVECTION CURRENTLY EXTENDS FROM THE OUTER BANKS TO THE EXTREME SERN VA COAST. THE STRONG LOW/DEEP LAYER SHEAR WILL SUPPORT SUPERCELLS AND THE POTENTIAL FOR TORNADOES THROUGH THE MORNING HOURS...REFERENCE WW 762. AS ERNESTO WEAKENS AND MOVES NWD INTO VA AND ENCOUNTERS AN INCREASINGLY COOLER AND MORE STABLE BOUNDARY LAYER...THE TORNADO THREAT SHOULD DIMINISH BY EARLY AFTERNOON. ...CENTRAL PLAINS... SKIES HAVE CLEARED ACROSS NERN CO AS EARLIER CONVECTIVE COMPLEX HAD MOVED EWD INTO KS...WITH ONLY A FEW REMAINING STORMS. BOUNDARY LAYER IS RELATIVELY MOIST AND STORMS ARE ONCE AGAIN EXPECTED TO DEVELOP NEAR THE HIGHER TERRAIN THIS AFTERNOON AS THE COLD FRONT SURGES SWD. THOUGH ONLY 10-15 KT WINDS ARE FORECAST AHEAD OF THE FRONT FROM THE SURFACE TO 600 MB...STRONGLY VEERING WINDS IN THE 3 KM AND 30-50 KT WINDS FROM 600-250MB SHOULD SUPPORT DEEP LAYER SHEAR NEAR 40 KT. ALTHOUGH SUPERCELL STRUCTURES ARE POSSIBLE...THE FRONTAL FORCING AND WEAK LOW LEVEL WINDS ARE EXPECTED TO RESULT IN MERGING STORM OUTFLOWS. THIS MAY AID IN THE EVOLUTION OF AN MCS IN ERN CO BY LATE AFTERNOON. THIS SYSTEM SHOULD THEN SPREAD SEWD... ALONG WITH THE FRONT AND INTO THE INSTABILITY AXIS...ACROSS WRN KS INTO THE OK/TX PANHANDLES THIS EVENING...WITH A FEW HAIL AND DAMAGING WIND EVENTS. ..IMY.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 16:14:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 12:14:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011613 SWODY1 SPC AC 011612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT FRI SEP 01 2006 VALID 011630Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL HIGH PLAINS REGION... ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY SHOWS UPPER TROUGH MOVING ACROSS MT/WY DIGGING ESEWD IN RESPONSE TO UPSTREAM AMPLIFICATION OF RIDGE AXIS FROM OFF THE PACIFIC NW COAST INTO NRN BRITISH COLUMBIA. THIS TROUGH IS FORECAST TO MOVE INTO THE NRN HIGH PLAINS TONIGHT AND CLOSE OFF INTO AN UPPER LOW. ASSOCIATED COLD FRONT FROM MN SWWD INTO NWRN CO WILL MOVE SEWD ACROSS THE CENTRAL PLAINS AND PROVIDE THE PRIMARY FOCUS FOR CONVECTIVE DEVELOPMENT LATER THIS AFTERNOON INTO TONIGHT. SURFACE DEW POINTS ARE CURRENTLY IN THE MID/UPPER 50S ACROSS ERN CO/WRN KS REGION AND LITTLE CHANGE IN MOISTURE CONTENT IS EXPECTED IN ADVANCE OF THE APPROACHING COLD FRONT. VISIBLE SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS MUCH OF NORTH CENTRAL/NERN CO WHICH WILL PERMIT STRONGER DIABATIC HEATING TO OCCUR THIS AFTERNOON...CONTRIBUTING TO DESTABILIZATION WITH MLCAPE OF 1000-1500 J/KG LIKELY BY MID AFTERNOON. THESE FACTORS SUPPORT 12Z RUC/NAM AND 09Z SREF NAMKF CONTROL RUN FORECASTS OF CONVECTIVE INITIATION ALONG THE NORTH CENTRAL/NERN CO BORDER AREA BY MID/LATE AFTERNOON...AS FRONTAL CONVERGENCE AND LOW LEVEL UPSLOPE WINDS ENHANCE ASCENT OF MOIST/UNSTABLE AIR MASS. VERTICAL WIND PROFILES ARE EXPECTED TO EXHIBIT STRONG VEERING/DIRECTIONAL SHEAR WITH HEIGHT...WHICH WILL COMPENSATE FOR RELATIVELY MODEST WESTERLY WIND SPEEDS IN THE MID LEVELS /20-25 KT AT 500 MB/. RESULTANT 30-40 KT DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ISOLATED SUPERCELLS DURING THE LATE AFTERNOON AND EARLY EVENING. CONVECTION IS EXPECTED TO INCREASE IN COVERAGE AND CONSOLIDATE INTO ONE OR TWO MCS/S BY LATE EVENING...WITH ACTIVITY SPREADING SEWD INTO PARTS OF WRN KS AND POSSIBLY AS FAR SOUTH AS THE OK/NRN TX PANHANDLE REGION DURING THE OVERNIGHT HOURS. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH STRONGER STORMS. ...SERN VA... REMNANTS OF ERNESTO ARE CONTINUING TO MOVE NWD INTO SERN VA...WITH WIDESPREAD RAIN ACROSS VA AND THE DELMARVA REGION. THERMODYNAMIC PROFILES SUGGEST VERY LIMITED INSTABILITY AND THIS IS SUPPORTED BY THE LACK OF CG LIGHTNING STRIKES OVER LAND DURING THE LAST 6 HOURS. THE EXTENSIVE REGION OF CLOUDS/PRECIPITATION IN ADVANCE OF THE CIRCULATION CENTER SUGGEST THERE WILL BE FEW IF ANY OPPORTUNITIES FOR THE DEVELOPMENT OF LOCALIZED ZONES OF HEATING/DESTABILIZATION TO OCCUR. THUS...THE SEVERE POTENTIAL APPEARS TO HAVE DIMINISHED THIS MORNING AND THIS TREND IS EXPECTED TO CONTINUE THIS AFTERNOON AS THE CIRCULATION LIFTS NWD INTO A PROGRESSIVELY COOLER LOW LEVEL ENVIRONMENT. THE THREAT FOR AN ISOLATED BRIEF TORNADO OR STRONG CONVECTIVE WIND GUST MAY CONTINUE THIS AFTERNOON OVER SERN VA BUT OVERALL THREAT NO LONGER WARRANTS A SLIGHT RISK. ..WEISS/GUYER.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 19:59:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 15:59:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011959 SWODY1 SPC AC 011957 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0257 PM CDT FRI SEP 01 2006 VALID 012000Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN CO AND WRN KS... ...CNTRL HIGH PLAINS/SRN PLAINS... A HIGHLY MERIDIONAL UPPER-LEVEL TROUGH EXTENDS SWD ACROSS ERN MT AND ERN WY WITH THE SRN EXTENT LOCATED ACROSS NRN CO. AT THE SFC...A COLD FRONT IS MOVING SWD ACROSS NE CO AND STRONG LOW-LEVEL CONVERGENCE IS SHOWN ALONG THE BOUNDARY ACCORDING TO OBJECTIVE ANALYSIS. CONVECTION IS BEGINNING TO DEVELOP IN THE FRONT RANGE FOOTHILLS WITH OTHER STORMS INITIATING IN THE SANGRE DE CRISTOS. SFC DEWPOINTS ALONG AND SOUTH OF I-70 ARE NEAR 60 F AND MODERATE INSTABILITY IS IN PLACE. AS A RESULT...THUNDERSTORMS SHOULD INCREASE IN COVERAGE ACROSS ECNTRL AND SERN CO LATE THIS AFTERNOON WITH MCS DEVELOPMENT POSSIBLE THIS EVENING. THE GRANADA CO PROFILER SHOWS 0-6 KM SHEAR OF 30-35 KT WHICH IS MOSTLY DUE TO DIRECTIONAL SHEAR BELOW 3 KM AND MID-LEVEL WLY FLOW ALOFT. THIS SHEAR PROFILE APPEARS REPRESENTATIVE OF THE SHEAR ENVIRONMENT ACROSS MUCH OF ERN CO AND SHOULD BE SUFFICIENT FOR ISOLATED SUPERCELLS ALTHOUGH STRONG MULTICELL STORMS WILL ALSO BE LIKELY. VERY STEEP LAPSE RATES EXIST ACROSS ERN CO AND THIS COMBINED WITH THE SHEAR AND INSTABILITY SHOULD BE FAVORABLE FOR LARGE HAIL WITH THE STRONGER CELLS. ALTHOUGH WIND DAMAGE APPEARS LESS LIKELY...STRONG WIND GUSTS MAY ALSO OCCUR ESPECIALLY WITH STORMS THAT FORM ALONG OR NEAR THE COLD FRONT. THE SEVERE THREAT SHOULD CONTINUE THROUGH MUCH OF THE EVENING AS AN MCS ORGANIZES AND MOVES INTO FAR WRN KS. ...ERN VA/SRN MD... THE CENTER OF TROPICAL DEPRESSION ERNESTO IS CURRENTLY LOCATED IN SE VA AND WILL CONTINUE TO MOVE NWD TONIGHT. VERY HEAVY RAINBANDS EXIST NORTH AND EAST OF THE CENTER AND A FEW THUNDERSTORMS MAY DEVELOP IN THE AREA AROUND CHESAPEAKE BAY. ALTHOUGH VERTICAL SHEAR PROFILES STILL REMAIN SUFFICIENT FOR ISOLATED ROTATING STORMS...TORNADOES APPEAR UNLIKELY DUE TO THE WEAK INSTABILITY IN PLACE. ANY MARGINAL TORNADO THREAT SHOULD GRADUALLY DECREASE OVERNIGHT AS THE DEPRESSION MOVES FURTHER INLAND. ..BROYLES.. 09/01/2006  From swody1 at goshenarc.org Sat Sep 2 00:49:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 20:49:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020049 SWODY1 SPC AC 020047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CDT FRI SEP 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL HIGH PLAINS... ...CENTRAL HIGH PLAINS... DEEP CONVECTION IS GRADUALLY EXPANDING ACROSS ERN CO IN ASSOCIATION WITH STRONG FRONTAL SURGE IN THE LEE OF THE CENTRAL ROCKIES. THIS ACTIVITY HAS EVOLVED INTO A SLOW-MOVING MCS THAT SHOULD CONTINUE TO PROPAGATE SEWD AT ROUGHLY 15-20 KT TOWARD SWRN KS/OK PANHANDLE. 00Z SOUNDINGS FROM BOTH DDC AND AMA ARE SUPPORTIVE OF MAINTAINING MCS-TYPE THUNDERSTORM CLUSTERS WITH MODEST DEEP LAYER SHEAR AND SBCAPE ON THE ORDER OF 1500-2000 J/KG. ALTHOUGH LOW LEVEL INFLOW IS NOT PARTICULARLY STRONG INTO THIS ACTIVITY...UNSTABLE THERMODYNAMIC PROFILES AND FRONTAL CONVERGENCE FAVOR LONG-LIVED MULTI-CELL UPDRAFTS...AND PERHAPS AN ISOLATED SUPERCELL. HAIL AND STRONG WINDS SHOULD ACCOMPANY THESE STORMS AS THEY SPREAD SEWD. ..DARROW.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 05:22:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 01:22:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020523 SWODY1 SPC AC 020521 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 AM CDT SAT SEP 02 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE PATTERN WILL BECOME INCREASINGLY HOSTILE FOR SEVERE DEEP CONVECTION OVER THE NEXT FEW DAYS AS LOW LEVEL CONVERGENCE ALONG ADVANCING SFC FRONT SPREADS WELL SOUTH OF ANY MEANINGFUL MID-HIGH LEVEL FLOW ACROSS THE PLAINS. GREATEST POTENTIAL FOR STRONG...POSSIBLY ORGANIZED STORMS WILL BE LIMITED TO STEEP LAPSE RATE REGIONS OF THE SWRN U.S...AND PERHAPS WITHIN A NARROW ZONE OF MODEST SHEAR...AHEAD OF UPPER LOW...FROM SWRN MN INTO NRN IA. ...ERN DAKOTAS/SWRN MN/NRN IA... EARLY MORNING WV IMAGERY STRONGLY SUPPORTS 00Z MODEL GUIDANCE IN SEWD MOVEMENT OF UPPER LOW ACROSS WRN DAKOTAS TOWARD NERN NEB. THIS FEATURE WILL MAINTAIN A ZONE OF WEAK LOW LEVEL CONVERGENCE FROM ERN SD INTO NRN IA AS SFC RIDGE BUILDS MAINLY SWD ACROSS THE NRN/CNTRL HIGH PLAINS. PRECIPITABLE WATER VALUES SHOULD HOLD IN EXCESS OF 1 INCH ALONG THIS AXIS...WITH SFC DEW POINTS IN THE MID-UPPER 50S. MODERATE BOUNDARY LAYER HEATING SHOULD PROVE INSTRUMENTAL IN AIDING CONVECTIVE DEVELOPMENT BY EARLY AFTERNOON. ALTHOUGH INSTABILITY WILL BE SOMEWHAT WEAK...LESS THAN 1000 J/KG...MARGINALLY SEVERE HAIL COULD OCCUR WITH STRONGER...MAINLY DIURNAL...THUNDERSTORMS. ...SWRN LOWER DESERTS OF AZ/SRN NM... AIRMASS HAS YET TO DRY SIGNIFICANTLY ALONG THE U.S./MEXICAN BORDER REGION FROM AZ INTO SRN NM...PER ANOTHER ACTIVE CONVECTIVE DAY FRIDAY...AND ONGOING THUNDERSTORM CLUSTERS JUST SOUTH OF THE BORDER OVER NRN MEXICO. CONVECTION SHOULD READILY DEVELOP AGAIN BY MID-LATE AFTERNOON ACROSS THIS REGION...WITH SWD PROPAGATION EXPECTED AS UPDRAFTS MATURE. STEEP LAPSE RATE ENVIRONMENT SHOULD SUPPORT AT LEAST GUSTY WINDS WITH STRONGER RAIN CORES. ..DARROW/GRAMS.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 12:36:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 08:36:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021236 SWODY1 SPC AC 021234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT SAT SEP 02 2006 VALID 021300Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A WEAK...BUT BROAD...TROUGH EXTENDED FROM THE NRN/CENTRAL PLAINS EWD INTO THE OH VALLEY. WITHIN THIS TROUGH...A CLOSED LOW WAS LOCATED OVER SD THIS MORNING AND IS FORECAST TO DRIFT SLOWLY SEWD INTO FAR NERN NEB BY SUNDAY MORNING. AT THE SURFACE...LOW PRESSURE ASSOCIATED WITH THE REMNANTS OF ERNESTO WAS LOCATED IN THE DELMARVA REGION. A WEAK TROUGH/FRONT EXTENDED FROM THIS LOW SWD OFF THE EAST COAST...AND THEN CROSSED THE NRN FL PENINSULA SWWD INTO THE NRN GULF. A REINFORCING COLD FRONT STRETCHED FROM WRN IA SWWD INTO THE TX PANHANDLE/NERN NM AND IS FORECAST TO PUSH THROUGH KS/OK AND INTO THE MAIN BODY OF NRN TX TONIGHT. ALTHOUGH PRECIPITATION IS EXPECTED THROUGH THE DAY AHEAD/ALONG THE FRONT...WEAK CONVERGENCE AND INSTABILITY WILL LIMIT A SEVERE THREAT WITH THE FRONTAL SYSTEM. ...SWRN MN/WRN IA... MOSTLY CLOUDY SKIES ARE LIKELY TO REDUCE HEATING AND INSTABILITY THROUGH THE DAY. HOWEVER...500 MB TEMPERATURES ARE FORECAST TO COOL SEVERAL DEGREES AND RANGE FROM -14C TO -16C BY LATE AFTERNOON... RESULTING IN MUCAPE VALUES AOB 500 J/KG. SHOWERS CURRENTLY IN THE AREA ARE EXPECTED TO WEAKEN AND PUSH EWD AS DRY SLOT IN ERN SD SPREADS EWD. STRONG DIFFLUENT FLOW ALOFT AT 250-300 MB ALONG WITH STRENGTHENING HIGH LEVEL DIVERGENCE SHOULD PROVIDE SUFFICIENT LIFT FOR A FEW THUNDERSTORMS THIS AFTERNOON. ALTHOUGH 35-40 KT DEEP LAYER SHEAR WOULD AID IN STORM ORGANIZATION...WEAK INSTABILITY IS EXPECTED TO LIMIT THE SEVERE WEATHER THREAT. THEREFORE...ONLY A 5% PROBABILITY FOR HAIL/WIND IS CURRENTLY FORECAST. ...SRN AZ... WV IMAGERY SHOWS THAT A HIGH LEVEL SHORTWAVE TROUGH WAS MOVING EWD THROUGH CENTRAL AZ WITH HIGH LEVEL DRYING BEHIND IT. THE CURRENT EWD MOTION AT 15 KT SHOULD TAKE THIS SYSTEM EAST OF THE STATE BY EARLY AFTERNOON. HOWEVER...AS HURRICANE JOHN MOVES NWWD ALONG THE SRN BAJA PENINSULA...MID/HIGH LEVEL MOISTURE IS BEING ADVECTED NWWD FROM MEXICO TOWARD SRN AZ. AS TEMPERATURES WARM TO AOA 100 DEGREES AND MIX TO MOISTURE BETWEEN 600 AND 700 MB...SCATTERED HIGH BASED CONVECTION SHOULD DEVELOP. MUCAPES AROUND 1000 J/KG AND DRY ADIABATIC LAPSES RATES IN THE LOWER 2-3 KM WOULD BE FAVORABLE FOR AT LEAST GUSTY WINDS NEAR THE STRONGER CORES. ..IMY/GRAMS.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 16:25:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 12:25:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021625 SWODY1 SPC AC 021624 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CDT SAT SEP 02 2006 VALID 021630Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SRN AZ... LATEST WATER VAPOR IMAGERY SHOWS HURRICANE JOHN ACROSS THE SRN PART OF BAJA CA WITH A PLUME OF MOISTURE EXTENDING NWD ACROSS NWRN MEXICO INTO SE AZ. MID-LEVEL MOISTURE SHOULD GRADUALLY INCREASE ACROSS SCNTRL AZ AS HURRICANE JOHN CONTINUES TO MOVE NWWD TODAY. SFC ANALYSIS SHOWS DEWPOINTS ACROSS THE SRN HALF OF AZ IN THE 55 TO 65 F RANGE WITH MODERATE INSTABILITY ALREADY IN PLACE SOUTH OF I-10 IN SW AZ. DESTABILIZATION WILL CONTINUE THIS AFTERNOON WITH SCATTERED THUNDERSTORMS DEVELOPING ALONG THE MOGOLLON RIM. FORECAST SOUNDINGS LATE THIS AFTERNOON ACROSS SCNTRL AZ SHOW DEEP ELY FLOW BELOW 700 MB WITH 0-6 KM SHEAR VALUES AROUND 20 KT. THIS COMBINED WITH LOW-LEVEL LAPSE RATES EXCEEDING 9.0 C/KM MAY BE FAVORABLE FOR STRONG WIND GUSTS WITH A FEW OF THE STRONGER MULTICELL STORMS THROUGH EARLY EVENING. ...MN/IA... A CLOSED-OFF UPPER-LEVEL LOW OVER THE NRN PLAINS WILL CONTINUE TO MOVE SLOWLY SEWD TODAY. STRONG LARGE-SCALE ASCENT ON THE EAST SIDE OF THE LOW WILL MOVE EWD INTO THE UPPER MS VALLEY SUPPORTING THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON ALONG THE LEADING EDGE OF ASCENT. LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS CNTRL IA INTO SRN MN WHERE DEWPOINTS ARE MOSTLY IN THE LOWER TO MID 60S F WITH LOCALLY HIGHER DEWPOINTS IN FAR SW AZ. DESTABILIZATION SHOULD CONTINUE ALONG THE MOIST AXIS THROUGH LATE AFTERNOON. THIS COMBINED WITH COOLING MID-LEVEL TEMPS AND INCREASING VERTICAL SHEAR ASSOCIATED WITH THE UPPER LOW MAY BE SUFFICIENT FOR A FEW STORMS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL LATE THIS AFTERNOON. ..BROYLES/GUYER.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 17:11:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 13:11:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021711 SWODY1 SPC AC 021709 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1209 PM CDT SAT SEP 02 2006 VALID 021630Z - 031200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED ...SRN AZ... LATEST WATER VAPOR IMAGERY SHOWS HURRICANE JOHN ACROSS THE SRN PART OF BAJA CA WITH A PLUME OF MOISTURE EXTENDING NWD ACROSS NWRN MEXICO INTO SE AZ. MID-LEVEL MOISTURE SHOULD GRADUALLY INCREASE ACROSS SCNTRL AZ AS HURRICANE JOHN CONTINUES TO MOVE NWWD TODAY. SFC ANALYSIS SHOWS DEWPOINTS ACROSS MUCH OF THE SRN HALF OF AZ IN THE 55 TO 65 F RANGE. LOCALLY HIGHER DEWPOINTS ARE IN FAR SW AZ WHERE MODERATE INSTABILITY IS ALREADY IN PLACE SOUTH OF I-10. DESTABILIZATION WILL CONTINUE THIS AFTERNOON WITH SCATTERED THUNDERSTORMS DEVELOPING ALONG THE MOGOLLON RIM. FORECAST SOUNDINGS LATE THIS AFTERNOON ACROSS SCNTRL AZ SHOW DEEP ELY FLOW BELOW 700 MB WITH 0-6 KM SHEAR VALUES AROUND 20 KT. THIS COMBINED WITH LOW-LEVEL LAPSE RATES EXCEEDING 9.0 C/KM MAY BE FAVORABLE FOR STRONG WIND GUSTS WITH A FEW OF THE STRONGER MULTICELL STORMS THROUGH EARLY EVENING. ...MN/IA... A CLOSED-OFF UPPER-LEVEL LOW OVER THE NRN PLAINS WILL CONTINUE TO MOVE SLOWLY SEWD TODAY. STRONG LARGE-SCALE ASCENT ON THE EAST SIDE OF THE LOW WILL MOVE EWD INTO THE UPPER MS VALLEY SUPPORTING THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON ALONG THE LEADING EDGE OF ASCENT. LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS CNTRL IA INTO SRN MN WHERE DEWPOINTS ARE IN THE LOWER TO MID 60S F. DESTABILIZATION SHOULD CONTINUE ALONG THE MOIST AXIS THROUGH LATE AFTERNOON. THIS COMBINED WITH COOLING MID-LEVEL TEMPS AND INCREASING VERTICAL SHEAR ASSOCIATED WITH THE UPPER LOW MAY BE SUFFICIENT FOR A FEW STORMS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL LATE THIS AFTERNOON. ..BROYLES.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 19:54:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 15:54:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021954 SWODY1 SPC AC 021952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0252 PM CDT SAT SEP 02 2006 VALID 022000Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SRN MN/IA... CLOSED UPPER LOW...CURRENTLY CENTERED OVER SD PER SATELLITE IMAGERY...WILL MOVE SLOWLY TOWARD NERN NEB THIS FORECAST PERIOD. ASCENT ALONG THE LEADING EDGE OF THIS LARGE CIRCULATION IS EXPECTED TO MAINTAIN WEAK LOW LEVEL CONVERGENCE EXTENDING FROM NRN MO INTO SRN MN. A NARROW AXIS OF MOISTURE EXISTS ALONG THIS BOUNDARY WITH SURFACE DEWPOINTS IN THE LOWER-MID 60S. MODEST SURFACE HEATING SHOULD LIMIT DEVELOPMENT OF STRONGER INSTABILITY...WITH MLCAPE VALUES REMAINING AOB 500 J/KG FROM CENTRAL IA INTO SRN MN. THE COMBINATION OF INCREASING ASCENT...DEEP LAYER SHEAR AND STEEPENING MID LEVEL LAPSE RATES WITH THE APPROACH OF THE UPPER LOW SHOULD SUPPORT A FEW ORGANIZED STORMS. HAIL SHOULD BE THE PRIMARY THREAT WITH THE STRONGER CORES. IN ADDITION...OBJECTIVE ANALYSES INDICATED LARGE VALUES OF 0-3 KM CAPE CO-LOCATED WITH SUFFICIENT NEAR-SURFACE VERTICAL VORTICITY ALONG THE AXIS OF LOW LEVEL CONVERGENCE. THIS MAY SUPPORT A COUPLE OF LANDSPOUTS. ...AZ... VISIBLE IMAGERY/LIGHTNING DATA INDICATED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN OF THE FOUR CORNERS REGION SWWD TO ALONG THE MOGOLLON RIM AND INTO SERN CA WHERE THE AIR MASS HAS BECOME MODERATELY UNSTABLE. NWD MOISTURE RETURN WILL CONTINUE INTO SRN AZ/SRN CA THIS FORECAST PERIOD MAINTAINING MODERATE INSTABILITY ACROSS THIS REGION AS SURFACE TEMPERATURES RISE TO 100+ BENEATH STEEP MID LEVEL LAPSE RATES. WEAK NLY MID LEVEL WINDS DEVELOPING ACROSS AZ AFTER 00Z AND POTENTIAL FOR COLD POOL DEVELOPMENT MAY ALLOW STORMS TO DEVELOP SSWWD INTO INSTABILITY AXIS...WITH ISOLATED THREAT FOR STRONG WIND GUSTS. ..PETERS.. 09/02/2006  From swody1 at goshenarc.org Sun Sep 3 00:40:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 20:40:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030040 SWODY1 SPC AC 030038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT SAT SEP 02 2006 VALID 030100Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...AZ/SRN CA... STRONG TO POTENTIALLY SEVERE TSTMS CONTINUE TO INCREASE IN COVERAGE THIS EVENING FROM ALONG THE MOGOLLON RIM SWD THROUGH THE LOWER DESERTS OF SRN AZ AND ACROSS THE CO RIVER INTO SRN CA. THESE STORMS ARE OCCURRING WITHIN LOW-LEVEL MOISTURE SURGE OFF THE GULF OF CA WHERE OBSERVED DEWPOINTS ARE IN THE LOW TO MID 60S. WHEN COUPLED WITH TEMPERATURES IN THE 90S TO 100-105 F...AMBIENT AIR MASS REMAINS MODERATELY UNSTABLE WITH MAXIMUM MLCAPES STILL AROUND 1000-1500 J/KG OVER SWRN AZ INTO FAR SERN CA. REGIONAL VWPS INDICATE THAT TROPOSPHERIC FLOW REMAINS QUITE WEAK BELOW 9 KM AGL WITH STORM MOTIONS LARGELY GOVERNED BY PROPAGATION ALONG MERGING/ORGANIZING OUTFLOW BOUNDARIES. GIVEN THE PRESENCE OF STEEP LOW-LEVEL LAPSE RATES AND DCAPES OF 1000-1500 J/KG...LOCALLY DAMAGING WIND GUSTS WILL REMAIN THE PRIMARY SEVERE WEATHER HAZARD WITH THE MOST INTENSE CELLS THROUGH 04-05Z. ..MEAD.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 05:41:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 01:41:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030541 SWODY1 SPC AC 030540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1240 AM CDT SUN SEP 03 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER THE MID MO VALLEY... ...SYNOPSIS... COMPLEX BLOCKING PATTERN WILL CONTINUE THIS PERIOD WITH THE PRIMARY FEATURES BEING AN AMPLIFIED RIDGE FROM THE SWRN DESERTS INTO THE CANADIAN PRAIRIES AND A MID TO UPPER-LEVEL LOW WHICH WILL TRANSLATE SLOWLY SEWD THROUGH THE MIDDLE AND LOWER MO VALLEY. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO THE UPPER LOW WILL CONCURRENTLY DEVELOP SEWD FROM SERN SD ALONG THE MO VALLEY OF ERN NEB/WRN IA. ATTENDANT FRONTAL BOUNDARY /THE NRN EXTENT OF WHICH BEING OCCLUDED AND PRECEDING SURFACE LOW/ WILL GENERALLY EXTEND FROM ERN IA/WRN IL SWWD INTO SERN OK/NRN TX BY AFTERNOON. ...MID MO VALLEY... IT APPEARS DEEP...MOIST CONVECTION WILL BECOME FOCUSED IN TWO AREAS THIS AFTERNOON...1) ALONG OCCLUDED FRONTAL ZONE FROM SERN MN/WRN WI SWD INTO ERN IA AND WRN IL...AND 2) INVOF THE SURFACE AND UPPER LOWS OVER ERN NEB/WRN IA. THE GREATER POTENTIAL FOR SEVERE STORMS CAPABLE OF MAINLY SEVERE HAIL IS FORECAST TO EXIST WITH THE LATTER. 03/00Z UPPER AIR OBSERVATIONS INDICATE THAT A POCKET OF RELATIVELY COLD MID-LEVEL TEMPERATURES /I.E. -18 TO -20 C AT 500 MB/ ARE ASSOCIATED WITH THE UPPER LOW. DAYTIME HEATING COUPLED WITH THESE COLD TEMPERATURES WILL RESULT IN THE DEVELOPMENT OF STEEP LOW TO MID-LEVEL LAPSE RATES WITH AFTERNOON SBCAPES INCREASING TO AROUND 1000 J/KG. EXPECT TSTMS TO INCREASE IN COVERAGE THROUGH THE AFTERNOON ACROSS ERN NEB/WRN IA...FOCUSED LARGELY BY LOW-LEVEL CONVERGENCE INVOF ATTENDANT SURFACE LOW. WHILE STORMS SHOULD REMAIN RELATIVELY LOW-TOPPED...STRENGTHENING MID AND HIGH-LEVEL FLOW AROUND SRN PERIPHERY OF UPPER LOW MAY BE SUFFICIENT TO SUPPORT SOME UPDRAFT ROTATION WITH SEVERE HAIL BEING THE PRIMARY SEVERE THREAT. HOWEVER...SHOULD STRONG DIABATIC HEATING OCCUR NEAR SURFACE LOW...POTENTIAL WILL EXIST FOR A BRIEF TORNADO OWING TO THE CO-LOCATION OF STEEP LOW-LEVEL LAPSE RATES AND CONCENTRATED ZONE OF VORTICITY. ...LOWER CO VALLEY... LOW-LEVEL MOISTURE SURGE FROM THE GULF OF CA WILL BE MAINTAINED THROUGH THE PERIOD...SUPPORTING DEWPOINTS IN THE 60S. THIS MOISTURE IN CONJUNCTION WITH ANTICIPATED STRONG DAYTIME HEATING WILL ONCE AGAIN CONTRIBUTE TO POCKETS OF MODERATE INSTABILITY LATER TODAY WITH SBCAPES OF 1000-1500 J/KG. FORECAST SOUNDINGS SUGGEST THAT VERTICAL SHEAR WILL REMAIN RELATIVELY WEAK...HOWEVER THE STEEP LOW-LEVEL LAPSE RATES AND MODERATE INSTABILITY SHOULD BE SUPPORTIVE OF ISOLATED STRONG TO SEVERE STORMS CAPABLE OF MAINLY LOCALLY DAMAGING WIND GUSTS. ..MEAD/GRAMS.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 12:39:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 08:39:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031240 SWODY1 SPC AC 031238 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 AM CDT SUN SEP 03 2006 VALID 031300Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF EXTREME ERN NEB AND WRN IA... ...SYNOPSIS... CUTOFF LOW OVER SERN SD IS FORECAST TO MOVE SLOWLY ESEWD AND ACROSS IA LATER TODAY AND TONIGHT. A WEAK FRONT WILL ACCOMPANY THIS LOW AND SHOULD EXTEND FROM CENTRAL WI SSWWD INTO SERN OK/CENTRAL TX BY LATE AFTERNOON. HIGH PRESSURE ALOFT OVER NV AND SRN TX WILL RESULT IN A WEAK UPPER LEVEL TROUGH OVER THE LOWER CO VALLEY. ...EXTREME ERN NEB/WRN IA... LATEST RUC ANALYSIS AND MODEL FORECAST INDICATES A POCKET OF RELATIVELY COLD MID-LEVEL TEMPERATURES /-18 TO -20 C AT 500 MB/ WILL SHIFT SEWD FROM SERN SD INTO WRN IA THIS AFTERNOON. DAYTIME HEATING COUPLED WITH THE COLD TEMPERATURES ALOFT WILL RESULT IN STEEP LOW TO MID-LEVEL LAPSE RATES...WITH SBCAPES RANGING FROM 500 TO 1000 J/KG. THE INCREASING INSTABILITY AND LIFT ASSOCIATED WITH THE UPPER LOW IS EXPECTED TO AID THUNDERSTORM DEVELOPMENT ACROSS THE AREA THIS AFTERNOON. THOUGH INSTABILITY WILL BE WEAK...30-50 KT MID LEVEL WINDS ON THE SRN PERIPHERY OF THE UPPER LOW MAY SUPPORT BRIEF UPDRAFT ROTATION. GIVEN THE STEEP MID LEVEL LAPSE RATES AND COLD TEMPERATURES ALOFT...HAIL IS EXPECTED TO BE THE PRIMARY SEVERE THREAT. HOWEVER...THE POTENTIAL WILL EXIST FOR A SHORT LIVED TORNADO DUE TO THE STEEP LOW-LEVEL LAPSE RATES AND CONCENTRATED ZONE OF VORTICITY. ...WRN WI/NWRN IL AND EXTREME ERN IA... BAND OF SHOWERS/ISOLATED STORMS ARE CURRENTLY LOCATED NEAR THE FRONT ACROSS SERN MN AND ERN IA AND SHOULD PUSH SLOWLY EWD INTO WI/NWRN IL THIS AFTERNOON. IF ENOUGH SUNSHINE CAN OCCUR AND WARM TEMPERATURES INTO THE LOWER/MID 70S...THESE READINGS ALONG WITH DEWPOINTS IN THE UPPER 50S WILL YIELD 500-750 J/KG OF MLCAPE. THIS INSTABILITY COMBINED WITH LOW LEVEL CONVERGENCE LIKELY WOULD BE SUFFICIENT FOR SURFACE BASED THUNDERSTORMS TO DEVELOP JUST EAST OF THE PRE-MENTIONED CONVECTIVE BAND. A COUPLE OF NON-SUPERCELL TORNADOES DEVELOPED SATURDAY IN IA...DURING THE EARLY CONVECTIVE STAGES. A SIMILAR ENVIRONMENT WILL BE PRESENT OVER THIS AREA TODAY AND AN ISOLATED TORNADO IS POSSIBLE...THOUGH THE THREAT SHOULD BE TOO ISOLATED AND BRIEF TO WARRANT MORE THAN A 2% TORNADO PROBABILITY. ...LOWER CO VALLEY... LOW-LEVEL MOISTURE SURGE FROM THE GULF OF CA WILL BE MAINTAINED ACROSS THE REGION AS TROPICAL STORM JOHN CONTINUES MOVING NWWD ALONG THE BAJA PENINSULA. ALTHOUGH OVERNIGHT PRECIPITATION AND MORNING CLOUDS ARE EXPECTED TO HOLD TEMPERATURES DOWN SOME FROM SATURDAY'S HIGHS...THE MOIST ENVIRONMENT...DIURNAL HEATING AND PRESENCE OF A WEAK TROUGH ALOFT SHOULD RESULT IN SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING. WEAK WINDS FROM THE SURFACE-500 MB WILL LIMIT VERTICAL SHEAR...THOUGH STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT STRONG TO SEVERE WIND GUSTS. HOWEVER...THE STRONG CONVECTIVE OVERTURNING DURING THE PAST 24 HOURS AND LESS WARMING THAN SATURDAY SUGGESTS THE THREAT SHOULD BE TOO ISOLATED FOR A SLIGHT RISK. ..IMY/GRAMS.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 16:07:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 12:07:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031607 SWODY1 SPC AC 031605 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CDT SUN SEP 03 2006 VALID 031630Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER EXTREME ERN NEB AND WRN IA... ...ERN NEB/WRN IA... WELL-DEFINED COLD UPPER LOW OVER SERN SD IS FORECAST TO CONTINUE MOVING SEWD INTO NWRN IA THIS AFTERNOON AND CENTRAL IA TONIGHT. 500 MB TEMPERATURES OF -18 TO -20C ASSOCIATED WITH THE LOW WILL ENHANCE LOW-MID LEVEL LAPSE RATES...ESPECIALLY WHERE BREAKS IN CLOUD COVER ALLOW STRONGER DIURNAL HEATING TO OCCUR. ALTHOUGH SURFACE DEWPOINTS WILL LIKELY REMAIN IN THE LOW 50S...TEMPERATURES WARMING INTO THE LOW 70S WILL RESULT IN MODEST INSTABILITY WITH MLCAPE OF 500-1000 J/KG. DYNAMIC FORCING FOR ASCENT WILL BE AIDED BY LEFT EXIT REGION OF STRONG WESTERLY MID/UPPER LEVEL JET STREAK ON THE SRN PERIPHERY OF THE UPPER LOW. THIS WILL CONTRIBUTE TO SUFFICIENT DEEP LAYER SHEAR OF 35-45 KT TO AID STORM ORGANIZATION AND INTENSITY. CELLS ARE FORECAST TO INCREASE IN COVERAGE OVER EXTREME ERN NEB AND WRN IA BY EARLY AFTERNOON SPREADING EWD TOWARD CENTRAL IA BEFORE DIMINISHING IN INTENSITY DURING THE EVENING. ISOLATED LARGE HAIL WILL BE THE PRIMARY SEVERE THREAT. ...UPPER MS VALLEY... COLD FRONT WILL MOVE SLOWLY EWD ACROSS SERN MN/ERN IA TOWARD SWRN WI/NWRN IL THIS AFTERNOON. EXTENSIVE BAND OF CLOUDS AND WIDELY SCATTERED PRECIPITATION WITHIN THE FRONTAL ZONE WILL INHIBIT WIDESPREAD DIABATIC HEATING...ALTHOUGH ANY BREAKS IN THE CLOUD COVER THAT CAN DEVELOP WILL CONTRIBUTE TO DESTABILIZATION WITH MLCAPE AROUND 500 J/KG. THE POSSIBILITY OF ISOLATED NON-SUPERCELL TORNADO DEVELOPMENT /SIMILAR TO YESTERDAY ACROSS IA/ WILL BE MAINTAINED ALONG THE FRONT THIS AFTERNOON. ...AZ/SERN CA... DEEP LAYER MOISTURE CONTINUES TO SPREAD NWD FROM TROPICAL STORM JOHN INTO SOUTH CENTRAL/ERN AZ...AS MODERATE SWLY UPPER FLOW ACROSS THE LOWER CO RIVER VALLEY INTO WRN/NRN AZ RESULTS IN A SSW/NNE MID AND UPPER LEVEL MOISTURE DISCONTINUITY IN THE WATER VAPOR IMAGERY ACROSS CENTRAL AZ. 12Z SOUNDINGS INDICATE AMPLE PRECIPITABLE WATER VALUES OF 1.0-1.5 INCHES ACROSS CENTRAL/SRN AZ INTO SERN CA...AND CLEARING SKIES OVER WRN AZ/SERN CA WILL PERMIT STRONG DIURNAL HEATING TO OCCUR. THIS WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPE OF 1000-1500 J/KG. VERTICAL WIND PROFILES SHOW STRONGER ENELY MID LEVEL WINDS COMPARED TO YESTERDAY...WHICH MAY RESULT IN A STRONGER PROPAGATIONAL COMPONENT TO STORM MOTION DEVELOPING THIS AFTERNOON AND EVENING. A FEW STRONGER STORMS ARE EXPECTED ACROSS THIS REGION WITH POTENTIAL TO PRODUCE MARGINALLY SEVERE HAIL AND WET MICROBURSTS. ..WEISS/GUYER.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 20:04:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 16:04:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032003 SWODY1 SPC AC 032001 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0301 PM CDT SUN SEP 03 2006 VALID 032000Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN NEB AND WRN IA... ...ERN NEB/WRN IA... UPPER LOW...CURRENTLY MOVING INTO NWRN IA...WILL CONTINUE TO TRACK SLOWLY TO THE ESE INTO IA THIS FORECAST PERIOD. ATTENDANT SURFACE LOW WITH THIS UPPER LOW WAS LOCATED OVER NERN NEB WITH A SURFACE FRONT EXTENDING WSWWD THROUGH SRN NEB. COLD MID LEVEL TEMPERATURES /-20 C AT 500 MB PER RUC GUIDANCE/ COMBINED WITH SURFACE HEATING AHEAD OF SURFACE FRONT HAS RESULTED IN STEEP LOW AND MID LEVEL LAPSE RATES. GIVEN FAVORABLE THERMODYNAMICS AND ASCENT WITHIN EXIT REGION OF MID LEVEL JET...ADDITIONAL STORMS ARE EXPECTED TO DEVELOP ALONG NEB/IA BORDER AND SPREAD INTO IA BEFORE DIMINISHING THIS EVENING WITH LOSS OF DAYTIME HEATING. STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES SUGGEST HAIL WILL BE THE PRIMARY THREAT. ...UPPER MS RIVER VALLEY... TRENDS IN WATER VAPOR IMAGERY SUGGEST A SHORT WAVE TROUGH IS ROTATING AROUND THE UPPER LOW AND CURRENTLY MOVING NWWD THROUGH SERN AND CENTRAL MN. ATTENDANT COLD FRONT ALONG LEADING EDGE OF UPPER LOW WILL SPREAD INTO SWRN WI AND NWRN IL...WHILE A POST-FRONTAL SURFACE TROUGH...EXTENDING SWD INTO ERN IA TO NERN MO...ACTS AS ANOTHER FOCUS FOR THUNDERSTORM DEVELOPMENT. EXTENSIVE CLOUDINESS IN THE VICINITY OF BOTH SURFACE BOUNDARIES HAS LIMITED DIABATIC HEATING...AND RESULTANT AVAILABLE INSTABILITY. ANY HEATING THAT CAN OCCUR YET THIS AFTERNOON SHOULD ALLOW FOR AT LEAST MARGINAL INSTABILITY. THIS COMBINED WITH ASCENT AHEAD OF UPPER LOW AND WITH SHORT WAVE TROUGH IS EXPECTED TO SUPPORT ADDITIONAL DIURNALLY DRIVEN STORMS FROM CENTRAL MN/WRN WI INTO ERN IA AND NWRN IL. WEAK INSTABILITY WILL LIMIT HAIL THREAT...WHILE THE POTENTIAL DOES EXIST FOR ISOLATED NON-SUPERCELL TORNADO DEVELOPMENT ALONG THE FRONT THIS AFTERNOON. ...AZ/SERN CA... STRONG SURFACE HEATING ACROSS SERN CA TO THE LOWER CO RIVER VALLEY WITHIN A MOIST AIR MASS HAS RESULTED IN A MODERATELY UNSTABLE AIR MASS. ADDITIONAL SURFACE HEATING ACROSS WRN AZ SHOULD SUPPORT SIMILAR TRENDS IN INSTABILITY. VISIBLE IMAGERY AND LIGHTNING DATA INDICATED THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS THE HIGHER TERRAIN OF CENTRAL AND SERN AZ. GIVEN ENELY LOW-MID LEVEL WINDS...THERE WILL BE A GREATER POTENTIAL THIS FORECAST PERIOD FOR ACTIVITY TO PROPAGATE SWWD INTO THE LOWER ELEVATIONS WHERE INSTABILITY IS HIGHER AND SUPPORT WET MICROBURSTS. MARGINALLY SEVERE HAIL WILL ALSO BE A THREAT. ..PETERS.. 09/03/2006  From swody1 at goshenarc.org Mon Sep 4 00:37:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 20:37:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040037 SWODY1 SPC AC 040036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 PM CDT SUN SEP 03 2006 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...IA... AN ARC OF DEEP CONVECTION IS ONGOING THIS EVENING FROM THE I-35 CORRIDOR N OF DSM SWWD TO THE LNK/BIE AREAS IN ADVANCE OF UPPER LOW OVER NWRN IA. THESE STORMS HAVE TENDED TO WEAKEN OVER THE PAST HOUR LIKELY AS A RESULT OF WEAKENING LOW-LEVEL LAPSE RATES AND RESULTANT INSTABILITY. SOME POTENTIAL FOR ISOLATED SEVERE STORMS CAPABLE OF SEVERE HAIL WILL EXIST FOR THE NEXT COUPLE OF HOURS...THOUGH THIS THREAT SHOULD DIMINISH AFTER 03Z AS THE BOUNDARY LAYER COOLS AND STABILIZES. ...SWRN AZ/SRN CA... WHILE BOUNDARY-LAYER IS NOT AS MOIST AS 24 HOURS PRIOR...DEWPOINTS IN THE UPPER 50S TO LOWER 60S COUPLED WITH STRONG HEATING TO THE NWRN OF T.S. JOHN CIRRUS CANOPY HAVE RESULTED IN A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF AROUND 1000 J/KG. TSTMS DEVELOPING ALONG THE MOGOLLON RIM AS WELL AS DENSITY CURRENT PROPAGATING WWD THROUGH PIMA COUNTY MAY INTENSIFY THIS EVENING WHILE ENCOUNTERING MORE UNSTABLE AIR MASS ALONG THE CO RIVER VALLEY. WIDESPREAD ORGANIZED STORMS ARE NOT ANTICIPATED OWING TO MARGINAL VERTICAL SHEAR...THOUGH POTENTIAL WILL EXIST FOR ISOLATED STRONG/SEVERE CELLS GIVEN THE STEEP LOW-LEVEL LAPSE RATES. LOCALLY DAMAGING WIND GUSTS WILL BE THE PRIMARY SEVERE WEATHER THREAT THROUGH THE REMAINDER OF THE EVENING. ..MEAD.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 05:24:15 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 01:24:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040524 SWODY1 SPC AC 040522 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1222 AM CDT MON SEP 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER FAR ERN IA...SRN WI AND NRN IL... ...SYNOPSIS... AMPLIFIED LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY ONE PERIOD AS MID AND UPPER-LEVEL LOW /NOW OVER IA/ CONTINUES SEWD INTO THE OH VALLEY AND UPSTREAM RIDGE INTENSIFIES FROM THE SWRN DESERTS INTO ALBERTA. IN THE LOW-LEVELS...WEAK SURFACE REFLECTION OF UPPER LOW WILL DEVELOP SEWD ACROSS ERN IA INTO WRN IL DURING THE AFTERNOON AND EVENING HOURS WITH TRAILING FRONTAL BOUNDARY EXTENDING SWWD INTO THE ARKLATEX. MEANWHILE TO THE E...A SECONDARY BAROCLINIC ZONE WILL EXIST FROM THE CNTRL/ERN GULF COAST NEWD TO A WEAK INFLECTION POINT OVER ERN TN AND THEN EWD ACROSS NC. ...FAR ERN IA/NRN IL/SRN WI... SIMILAR TO SUNDAY OVER WRN IA...A CONCENTRATED CLUSTER OF TSTMS IS FORECAST TO DEVELOP INVOF SURFACE AND UPPER LOWS THIS AFTERNOON WITHIN ENVIRONMENT CHARACTERIZED BY STEEP LOW TO MID-LEVEL LAPSE RATES AND RESULTANT SBCAPES OF 500-1000 J/KG. PRIMARY BELT OF STRONGER MID AND UPPER TROPOSPHERIC FLOW ASSOCIATED WITH THIS LOW ARE EXPECTED TO REMAIN DISPLACED TO THE S ACROSS SRN IL INTO CNTRL IND...WITH EFFECTIVE BULK SHEARS OF GENERALLY 20-30 KTS ACROSS AXIS OF STRONGEST INSTABILITY. DESPITE THE MODEST INSTABILITY AND SHEAR...THE STRONGEST STORMS WILL BE CAPABLE OF SEVERE HAIL GIVEN THE STEEP LAPSE RATES AND COOL THERMODYNAMIC PROFILES. ACTIVITY SHOULD TEND TO WEAKEN BY 01-02Z AS BOUNDARY LAYER COOLS AND STABILIZES. ...CO FRONT RANGE... INCREASING LOW-LEVEL ELY WIND COMPONENT WILL RESULT IN VERTICAL SHEAR PROFILES BECOMING SUPPORTIVE OF ORGANIZED/ROTATING STORMS LATER TODAY. PRIMARY UNCERTAINTY IS WHETHER DEEP...MOIST CONVECTION WILL INITIATE AND BECOME SUSTAINED. CURRENT WATER VAPOR IMAGERY INDICATES A SHORT WAVE TROUGH ROTATING SWD AROUND IA UPPER LOW ACROSS NERN WY...WITH LATEST SHORT TERM MODEL GUIDANCE MOVING THIS FEATURE GENERALLY SWD ACROSS ERN CO TODAY. THE BOUNDARY LAYER IS NOT EXPECTED TO BECOME PARTICULARLY WARM...THOUGH THE PRESENCE OF MODEST LOW-LEVEL MOISTURE /DEWPOINTS IN THE MID 40S TO LOW 50S/ COUPLED WITH STEEP LOW TO MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO POCKETS OF INSTABILITY WITH SBCAPES OF 500-700 J/KG. FORCING FOR ASCENT ASSOCIATED WITH THE SHORT WAVE TROUGH ALONG WITH THE SUSTAINED UPSLOPE FLOW MAY BE SUFFICIENT TO INITIATE A FEW STORMS THIS AFTERNOON OR EVENING IN THE IMMEDIATE LEE OF THE HIGHER TERRAIN. THE STRONGEST STORMS WILL BE CAPABLE OF SOME SEVERE HAIL AND LOCALLY GUSTY WINDS. ...SRN/CNTRL APPALACHIANS... LATEST MODEL GUIDANCE SUGGESTS THAT A WEAK...LOWER LATITUDE IMPULSE WILL TRANSLATE NEWD THROUGH THE MID SOUTH TOWARD THE REGION TODAY...LIKELY FOCUSING CONCENTRATED TSTM DEVELOPMENT ALONG SW-NE ORIENTED LOW-LEVEL FRONTAL ZONE. LAPSE RATES ARE NOT EXPECTED TO BECOME PARTICULARLY STEEP...THOUGH THE PRESENCE OF A MOIST BOUNDARY LAYER WILL CONTRIBUTE TO POCKETS OF INSTABILITY WITH SBCAPES OF 500-1000 J/KG. SOME INCREASE IN MID-LEVEL FLOW WILL ACCOMPANY THIS TROUGH...WITH VERTICAL SHEAR BECOMING MARGINALLY SUPPORTIVE OF A FEW ORGANIZED STORMS CAPABLE OF MAINLY WET MICROBURSTS. ..MEAD/GRAMS.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 12:46:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 08:46:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041247 SWODY1 SPC AC 041245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0745 AM CDT MON SEP 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NRN/CENTRAL IL...SRN WI AND FAR ERN IA... ...SYNOPSIS... CLOSED LOW OVER CENTRAL IA AND ASSOCIATED TROUGH OVER THE MID/UPPER MS VALLEY REGION WILL MOVE ESEWD AND AMPLIFY...AS UPPER RIDGE BUILDS NWD FROM THE NRN ROCKIES INTO THE CANADIAN ROCKIES. IN ASSOCIATION WITH THE UPPER LOW...A WEAK SURFACE LOW IN NWRN IL WILL MOVE EWD INTO NRN IND BY LATE AFTERNOON WITH A TRAILING FRONTAL BOUNDARY EXTENDING SWWD INTO SRN OK/WRN TX. FURTHER TO THE EAST...A STATIONARY FRONT STRETCHES FROM AL NEWD INTO WRN NC...AND THEN EWD INTO EXTREME SERN VA. ...FAR ERN IA/NRN IL/SRN WI... EARLY THIS MORNING...ONE BAND OF CONVECTION WAS LOCATED IN THE ZONE OF STRONG DIFFLUENCE ALOFT FROM ERN IL INTO SRN WI...WHILE ANOTHER CLUSTER OF STORMS WAS LOCATED JUST SOUTHEAST OF THE UPPER LOW. THE STORMS IN IA ARE EXPECTED TO MOVE/DEVELOP EWD WITH THE UPPER LOW INTO NRN/CENTRAL IL THIS AFTERNOON. DESPITE MEAGER BOUNDARY LAYER MOISTURE...MID LEVEL LAPSE RATES NEAR 7C/KM AND -16 TO -18C 500 MB TEMPERATURES WILL RESULT IN SBCAPES OF 500-1000 J/KG. ALTHOUGH THE PRIMARY BELT OF STRONGER MID AND UPPER LEVEL WINDS WILL BE ON THE SOUTHERN PERIPHERY OF THE LOW FROM CENTRAL MO EWD INTO SRN INDIANA...DEEP LAYER SHEAR AT 20-30 KT WILL SUPPORT MULTICELL CLUSTERS ACROSS THE OUTLOOK AREA. THE STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT WILL SUPPORT MARGINALLY SEVERE HAIL IN THE STRONGEST STORMS. THE STORMS SHOULD WEAKEN QUICKLY AFTER 00Z AS THE BOUNDARY LAYER COOLS AND STABILIZES. ...SRN/CNTRL APPALACHIANS... MODELS ARE CONSISTENT IN DEVELOPING CONVECTION OVER THE AREA LATE THIS AFTERNOON...THOUGH SOME DIFFERENCES EXIST IN EXACT LOCATION. A FEW SHOWERS HAD ALREADY FORMED FROM ERN TN NEWD INTO SWRN VA... IN ZONE OF WEAK ISENTROPIC LIFT NORTH OF STATIONARY FRONT. ALTHOUGH LIFT IS FORECAST TO WEAKEN THIS MORNING...MODELS DEPICT A HIGH LEVEL SHORTWAVE TROUGH...CURRENTLY OVER ERN OK...MOVING INTO TN/NRN MS BY LATE AFTERNOON. THIS FEATURE PLUS STRENGTHENING DIFFLUENCE ALOFT...AHEAD OF A 90-100 KT HIGH LEVEL JET MAX...WILL RESULT IN LARGE SCALE FORCING. ALTHOUGH TEMPERATURES NEAR 90 AND DEWPOINTS AROUND 70 SHOULD RESULT IN MLCAPES FROM 1500-2500 J/KG SOUTH OF THE FRONT...IT APPEARS THE MAIN FORCING WILL BE NORTH OF THE FRONT...WHERE INSTABILITY WILL BE WEAKER. HOWEVER...MUCAPES FROM 500 TO 1000 J/KG AND DEEP LAYER SHEAR NEAR 30 KT MAY SUPPORT ISOLATED STRONG/MARGINALLY SEVERE STORMS ACROSS PORTIONS OF ERN TN...NRN AL...WRN CAROLINAS AND WRN VA THIS AFTERNOON AND EVENING. ...CO AND NERN NM FRONT RANGE... DEEP ELY UPSLOPE WINDS WITH MID LEVEL WINDS VEERING TO NWLY WILL RESULT IN FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/ROTATING STORMS THIS AFTERNOON. WATER VAPOR IMAGERY INDICATES A SHORT WAVE TROUGH WAS ROTATING SWD ACROSS ERN WY...AND LATEST MODEL GUIDANCE MAINTAINS THIS FEATURE IN ERN CO THROUGH THE AFTERNOON. THE BOUNDARY LAYER WILL NOT BE PARTICULARLY MOIST...THOUGH STEEP LOW/MID LEVEL LAPSE RATES SHOULD RESULT IN SBCAPES FROM 500-1000 J/KG. WEAK FORCING WITH SHORTWAVE TROUGH AND UPSLOPE FLOW MAY INITIATE A FEW STORMS WITH SEVERE HAIL/GUSTY WINDS OVER THE ERN FOOTHILLS MID/LATE AFTERNOON. A MORE STABLE ENVIRONMENT OVER THE PLAINS SHOULD LIMIT THE STORMS EWD EXTENT. SINCE STORM COVERAGE IS EXPECTED TO BE LIMITED...ONLY 5% HAIL/WIND PROBABILITIES ARE FORECAST. ..IMY/GRAMS.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 16:28:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 12:28:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041628 SWODY1 SPC AC 041626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CDT MON SEP 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDDLE AND UPPER MS VALLEY... ...MID/UPPER MS VALLEY... COLD UPPER LOW OVER IA IS EXPECTED TO CONTINUE MOVING ESEWD INTO NRN IL THIS AFTERNOON AND EVENING. ALTHOUGH THE MID LEVELS OF THE SYSTEM HAVE WARMED SLIGHTLY COMPARED TO YESTERDAY...500 MB TEMPERATURES OF -16 TO -18C WILL CONTRIBUTE TO MODERATELY STEEP LAPSE RATES ABOVE MODEST LOW LEVEL MOISTURE FIELD. VISIBLE IMAGERY SHOWS WIDESPREAD CLOUDS IN ADVANCE OF THE UPPER LOW OVER ERN IA/SRN WI AND NRN/CENTRAL IL...HOWEVER SEVERAL CLEAR SLOTS ARE EVIDENT OVER IL WHERE ENHANCED DIURNAL HEATING IS EXPECTED TO OCCUR. THIS WILL RESULT IN MESOSCALE ZONES OF GREATER INSTABILITY WHERE MLCAPE WILL REACH 500-1000 J/KG...WHICH SHOULD SUPPORT WIDELY SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING. MARGINALLY SEVERE HAIL AND ISOLATED STRONG WIND GUSTS WILL BE POSSIBLE WITH STRONGER CELLS. ...SRN APPALACHIANS... MOIST AIR MASS IS IN PLACE ACROSS THE SERN STATES WHERE SURFACE DEW POINTS ARE IN THE UPPER 60S/LOWER 70S. STRONG DIABATIC HEATING ACROSS NRN AL/NRN GA MAY ENHANCE THERMAL GRADIENT/DIFFERENTIAL HEATING BOUNDARY ACROSS THIS REGION AS CLOUDS PERSIST OVER ERN TN/ FAR NRN GA/SWRN NC AREA. HEATING WITHIN WEAKLY CAPPED ENVIRONMENT SHOULD ALLOW PARCELS TO REACH THEIR LFC WITH RESULTANT DEVELOPMENT OF SCATTERED THUNDERSTORMS. 20-30 KT WSWLY MID LEVEL WINDS WILL BE SUFFICIENT FOR MULTICELLULAR CLUSTERS TO DEVELOP WITH POTENTIAL FOR ISOLATED STRONG/MARGINALLY SEVERE STORMS THIS AFTERNOON AND EVENING. ...CO/NRN NM FRONT RANGE... WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH MOVING SSEWD TOWARD THE CENTRAL HIGH PLAINS WITH 25-30 KT NWLY MID LEVEL WINDS ACROSS THIS REGION. WIND PROFILES ARE EXPECTED TO EXHIBIT CONSIDERABLE VEERING WITH HEIGHT LATER THIS AFTERNOON WITH DEEP LAYER SHEAR OF 35-40 KT. LIMITING FACTOR FOR DEEP CONVECTION THIS AFTERNOON AND EVENING WILL BE THE MARGINAL LOW LEVEL MOISTURE WHICH WILL LIMIT MLCAPE VALUES TO AROUND 500 J/KG. ISOLATED STRONG THUNDERSTORMS MAY DEVELOP NEAR THE FRONT RANGE LATER THIS AFTERNOON AND EVENING WITH THREAT FOR HAIL/GUSTY WINDS BUT OVERALL COVERAGE APPEARS INSUFFICIENT TO SUPPORT A CATEGORICAL RISK AREA. ..WEISS/GUYER.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 20:02:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 16:02:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042000 SWODY1 SPC AC 041959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT MON SEP 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF NRN IL... ...ERN IA THROUGH NRN IL AND SRN WI... ZONES OF ASCENT ACCOMPANYING VORTICITY MAXIMA ROTATING THROUGH UPPER LOW CENTERED OVER ERN IA ARE CONTRIBUTING TO THE DEVELOPMENT OF SCATTERED THUNDERSTORMS. POCKETS OF SURFACE HEATING BENEATH 500 MB TEMPERATURES OF -16C TO -18C HAVE RESULTED IN MARGINAL INSTABILITY WITH MLCAPE NEAR 500 J/KG. STORMS SHOULD CONTINUE DEVELOPING THE REMAINDER OF THE AFTERNOON. STRONGEST STORMS ARE EXPECTED OVER NRN IL INTO EXTREME SRN WI. SURFACE HEATING IS CO-LOCATED WITH SLIGHTLY HIGHER LOW LEVEL MOISTURE IN THIS REGION...AND ASCENT IS MORE FOCUSED ON SURFACE BOUNDARY ALONG ERN PERIPHERY OF EWD ADVANCING VORT MAX. THE THERMODYNAMIC ENVIRONMENT WITH MODERATELY STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES IS SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS. OVERALL THREAT WILL REMAIN LIMITED BY MODEST INSTABILITY. ...S CNTRL CO... MUCH OF THE ASCENT ASSOCIATED WITH A VORT MAX MOVING SWD THROUGH THE NRN AND CNTRL HIGH PLAINS IS EXPECTED TO REMAIN N OF MOST OF CO THIS AFTERNOON. IN THE MEANTIME...WV IMAGERY AND FORECAST RUC SOUNDINGS SUGGEST THE ATMOSPHERE IN CNTRL AND SRN CO IS UNDER THE INFLUENCE OF LARGE SCALE SUBSIDENCE. THIS ALONG WITH LIMITED INSTABILITY IMPLIES THUNDERSTORM COVERAGE SHOULD REMAIN SPARSE AT BEST. IF ISOLATED STORMS DO MANAGE TO DEVELOP...STEEP LAPSE RATES AND DEEP LAYER SHEAR AROUND 40 KT WOULD SUPPORT A MARGINAL THREAT FOR ISOLATED HAIL. ..DIAL.. 09/04/2006  From swody1 at goshenarc.org Tue Sep 5 00:39:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 20:39:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050039 SWODY1 SPC AC 050038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT MON SEP 04 2006 VALID 050100Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...ERN IA INTO NRN IL/SRN WI... AN ARCING CLUSTER OF TSTMS CONTINUES THIS EVENING AHEAD OF UPPER LOW FROM NEAR ORD SSWWD TO E OF DEC ALONG LOW-LEVEL BAROCLINIC ZONE. THIS ACTIVITY HAS TENDED TO WEAKEN OVER THE PAST 1-2 HOURS...AND SHOULD CONTINUE TO DO SO THROUGH THE REMAINDER OF THE EVENING AS BOUNDARY LAYER COOLS AND STABILIZES. DEEP LAYER FORCING FOR ASCENT AHEAD UPPER LOW COUPLED WITH EXISTING WEAK INSTABILITY /REF. 00Z ILX SOUNDING/ MAY SUPPORT A FEW STRONG STORMS THROUGH 02Z WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL. ...CNTRL APPALACHIANS... A SMALL CLUSTER OF TSTMS HAS RECENTLY DEVELOPED OVER SERN TN / ENE OF CHA/ INVOF OF WEAK SURFACE LOW SITUATED ALONG SURFACE BOUNDARY EXTENDING FROM SERN MS TO NRN GA AND THEN ENEWD THROUGH CNTRL NC. OTHER STORMS ARE ALSO INTENSIFYING OVER CNTRL NC WITHIN A MOIST LOW-LEVEL AIR MASS WITH MUCAPES OF 500-1000 J/KG. WATER VAPOR IMAGERY SHOWS A FAIRLY STRONG SHORT WAVE TROUGH TRANSLATING EWD THROUGH THE TN AND SRN OH VALLEY...WHICH SHOULD SUPPORT AN INCREASE IN CONVECTIVE COVERAGE ACROSS THE CNTRL APPALACHIANS THIS EVENING. DESPITE THE MODEST INSTABILITY...BNA VWP INDICATES THE PRESENCE OF A 50 KT MID-LEVEL JET STREAK WHICH WILL SHIFT EWD ACROSS REGION TONIGHT...EFFECTIVELY ENHANCING VERTICAL SHEAR. THE MAJORITY OF TSTM ACTIVITY IS EXPECTED TO REMAIN SUB-SEVERE...HOWEVER THE INCREASING VERTICAL SHEAR MAY SUPPORT A FEW ORGANIZED STORMS CAPABLE OF MAINLY LOCALLY DAMAGING WINDS. ...WRN AZ INTO SERN CA... AN INTENSE CLUSTER OF TSTMS HAS RECENTLY DEVELOPED OVER SRN MOHAVE COUNTY WITHIN A HOT AND DEEPLY MIXED BOUNDARY LAYER WITH SBCAPES OF 1000-1500 J/KG. POTENTIAL WILL EXIST FOR THESE STORMS TO FORM A COLD POOL AND PROPAGATE SWWD ALONG THE CO RIVER VALLEY WHERE TEMPERATURES REMAIN 95-105 F. STRONG EVAPORATIONAL COOLING POTENTIAL IN THE SUB-CLOUD LAYER WILL BE SUPPORTIVE OF LOCALLY DAMAGING WINDS THROUGH THE REMAINDER OF THE EVENING. ..MEAD.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 05:30:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 01:30:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050530 SWODY1 SPC AC 050529 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 AM CDT TUE SEP 05 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER-LEVEL LOW OVER NRN IL/SRN WI IS FORECAST TO EVOLVE INTO A POSITIVELY TITLED OPEN WAVE FROM THE OH VALLEY INTO THE CNTRL GULF STATES WITH STRONGEST HEIGHT FALLS SHIFTING EWD INTO THE APPALACHIANS. IN THE LOW-LEVELS...PRIMARY BAROCLINIC ZONE INITIALLY SITUATED ALONG THE CNTRL/SRN APPALACHIANS WILL SHIFT EWD TODAY THROUGH THE PIEDMONT INTO THE COASTAL PLAIN WITH SEVERAL WEAK WAVES DEVELOPING NEWD ALONG THIS BOUNDARY. ...OH VALLEY... CORE OF UPPER LOW HAS SLOWLY MODIFIED OVER THE PAST COUPLE OF DAYS...RESULTING IN PROGRESSIVELY WEAKER INSTABILITY. STILL...MID-LEVEL TEMPERATURES ARE EXPECTED TO REMAIN BETWEEN -14 AND -16 C AT 500 MB...AND WHEN COUPLED WITH DAYTIME HEATING...AIR MASS WILL BECOME WEAKLY UNSTABLE WITH SBCAPES OF AROUND 500 J/KG. TSTMS WILL BECOME INCREASINGLY WIDESPREAD THIS AFTERNOON WITHIN DESTABILIZING ENVIRONMENT FROM PORTIONS OF ERN IL EWD THROUGH IND INTO WRN OH. THE RELATIVELY WEAK INSTABILITY AND MARGINAL VERTICAL SHEAR WILL LIMIT A MORE ORGANIZED SEVERE THREAT...THOUGH THE MOST INTENSE STORMS WILL BE CAPABLE OF SOME SEVERE HAIL INTO THE EARLY EVENING HOURS. ...CNTRL/SRN APPALACHIANS EWD TO THE ATLANTIC COAST... LOW-LEVEL AIR MASS WILL REMAIN QUITE MOIST E OF SURFACE FRONT WITH DEWPOINTS IN THE UPPER 60S TO LOW 70S...THOUGH WEAK LAPSE RATES SHOULD LIMIT SBCAPES TO 1000-1500 J/KG. INCREASING HEIGHT FALLS AHEAD OF EVOLVING MID-LEVEL TROUGH SHOULD SUPPORT AN INCREASE IN TSTM COVERAGE AND INTENSITY THIS AFTERNOON ACROSS THE PIEDMONT AND COASTAL PLAIN FROM CNTRL/SRN GA NEWD INTO ERN VA. IT APPEARS THAT THE STRONGER MID AND HIGH-LEVEL WIND FIELDS ASSOCIATED WITH UPPER TROUGH WILL LAG SURFACE WARM SECTOR TO THE W WITH GENERALLY 20-30 KTS OF DEEP LAYER SHEAR FORECAST ACROSS AXIS OF STRONGEST INSTABILITY. A FEW ORGANIZED STORMS /SOME EXHIBITING EPISODIC MID-LEVEL ROTATION/ WILL BE POSSIBLE WITH A THREAT OF LOCALLY DAMAGING WINDS AND PERHAPS A BRIEF TORNADO. HOWEVER...THE MARGINAL VERTICAL SHEAR AND WEAK LAPSE RATES SHOULD LIMIT A MORE SIGNIFICANT SEVERE WEATHER THREAT. ...S-CNTRL/SERN CO INTO NERN NM... LOW-LEVEL UPSLOPE REGIME IS EXPECTED TO PERSIST THROUGH THE PERIOD...MAINTAINING MODEST LOW-LEVEL MOISTURE WITH DEWPOINTS IN THE 40S TO LOWER 50S. WHEN COUPLED WITH DAYTIME HEATING AND STEEPENING LAPSE RATES...ENVIRONMENT WILL BECOME WEAKLY UNSTABLE WITH SBCAPES OF 500 J/KG. A WEAK IMPULSE OBSERVED ON WATER VAPOR IMAGERY OVER NRN UT WILL TURN MORE SEWD TODAY...COMBINING WITH THE SUSTAINED LOW-LEVEL OROGRAPHIC FORCING TO INITIATE DIURNAL STORMS OVER S-CNTRL CO. TSTMS SHOULD THEN MOVE/DEVELOP SEWD INTO NERN NM BY THIS EVENING. STRONG LOW-LEVEL VEERING BENEATH 20-30 KT NNWLY MID-LEVEL FLOW WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION. HOWEVER...THE MARGINAL INSTABILITY SHOULD LIMIT THE POTENTIAL FOR MORE WIDESPREAD...ORGANIZED STORM DEVELOPMENT. STILL...A FEW OF THE MORE INTENSE CELLS WILL BE CAPABLE OF MARGINALLY SEVERE HAIL. ..MEAD/JEWELL.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 12:39:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 08:39:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051239 SWODY1 SPC AC 051237 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0737 AM CDT TUE SEP 05 2006 VALID 051300Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER-LEVEL LOW OVER NRN IL IS FORECAST TO SHIFT ESEWD AND GRADUALLY EVOLVE INTO A POSITIVELY TILTED OPEN WAVE FROM THE OH VALLEY SWD INTO THE CENTRAL GULF STATES. PRIMARY BAROCLINIC ZONE...SITUATED THIS MORNING FROM AL NEWD INTO SERN VA...WILL SHIFT SEWD THIS AFTERNOON AND TONIGHT AS THE UPPER TROUGH APPROACHES FROM THE WEST. MOISTURE TRAPPED UNDER UPPER RIDGE IN THE WEST WILL RESULT IN SCATTERED THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND OVER THE HIGHER TERRAIN. ALTHOUGH THE SEVERE POTENTIAL WILL BE LOW ACROSS THE CONUS DUE TO LIMITED INSTABILITY AND WEAK FORCING...A FEW MARGINAL SEVERE WEATHER EVENTS ARE POSSIBLE ACROSS PORTIONS OF THE OH VALLEY...GA NEWD INTO SRN VA AND IN FOOTHILLS OF SRN CO INTO NERN NM. ...OH VALLEY... SCATTERED THUNDERSTORMS CONTINUED EARLY THIS MORNING...EAST AND SOUTH OF THE UPPER LOW. THIS CONVECTION WILL SPREAD SLOWLY EWD AND INTENSIFY SLIGHTLY AS DIURNAL HEATING RESULTS IN SBCAPES UP TO 1000 J/KG. GIVEN COLD 500 MB TEMPERATURES FROM -14 TO -16C...MARGINALLY SEVERE HAIL IS POSSIBLE WITH A FEW STORMS. HOWEVER...THE RELATIVELY WEAK INSTABILITY AND MARGINAL VERTICAL SHEAR WILL LIMIT THE SEVERE POTENTIAL. ...GA NEWD INTO SRN VA... SURFACE ANALYSIS INDICATES THAT A WEAK WAVE WAS LOCATED ALONG THE FRONT IN NRN GA. THE MODELS LIFT THIS FEATURE NEWD AND OFF THE SERN VA COAST TONIGHT. THE SEWD PUSH OF THE FRONT COMBINED WITH 30-60M HEIGHT FALLS SHOULD PROVIDE SUFFICIENT LIFT FOR NUMEROUS THUNDERSTORMS TO DEVELOP ALONG AND EAST OF THE FRONT TODAY AND INTO THE EVENING HOURS. ALTHOUGH THE BOUNDARY LAYER WILL REMAIN QUITE MOIST EAST OF THE FRONT WITH DEWPOINTS IN THE LOWER 70S...WEAK LAPSE RATES SHOULD LIMIT SBCAPES TO 1000-2000 J/KG. ALSO...THE STRONGER MID AND HIGH-LEVEL WINDS ASSOCIATED WITH THE UPPER TROUGH WILL REMAIN BEHIND THE COLD FRONT...WITH THE WARM SECTOR DEEP LAYER SHEAR EXPECTED TO ONLY RANGE FROM 20-30 KT. UNIDIRECTIONAL SWLY WINDS ABOVE THE BOUNDARY LAYER SUGGESTS SOME STORMS MAY DEVELOP INTO SMALL LINES WITH THE POSSIBILITY OF ISOLATED STRONG/SEVERE WIND GUSTS. HOWEVER...THE COMBINATION OF WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT THE SEVERE POTENTIAL. ...EXTREME SOUTH CENTRAL CO AND NERN NM... LOW-LEVEL ESELY UPSLOPE FLOW SHOULD MAINTAIN DEWPOINTS IN THE 40S TO LOWER 50S...DESPITE STRONG MIXING. STRONG HEATING AND STEEP MID LEVEL LAPSE RATES SHOULD YIELD AFTERNOON SBCAPES NEAR 500 J/KG. THE ELEVATED HEAT SOURCE WILL AID IN LATE AFTERNOON INITIATION OVER THE HIGHER TERRAIN OF FAR SRN CO AND NERN NM. ONCE STORMS FORM...STRONG LOW-LEVEL VEERING BENEATH 20-30 KT NNWLY MID-LEVEL WINDS WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR STORMS TO ROTATE. ALTHOUGH HAIL IS POSSIBLE WITH A STORM OR TWO...THE MEAGER MOISTURE AND INSTABILITY IS EXPECTED TO LIMIT THE NUMBER OF STORMS AND OVERALL SEVERE WEATHER THREAT. ..IMY/JEWELL.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 16:30:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 12:30:08 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051628 SWODY1 SPC AC 051626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CDT TUE SEP 05 2006 VALID 051630Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...CAROLINAS AREA THIS AFTERNOON/EVENING... THE MID LEVEL LOW OVER IL WILL BEGIN TO PROGRESS EWD AS AN OPEN WAVE...IN RESPONSE TO UPSTREAM HEIGHT FALLS ASSOCIATED WITH ANOTHER TROUGH DIGGING SEWD OVER ONTARIO. WEAK SURFACE WAVES ALONG A FRONT FROM THE PIEDMONT TO THE TIDEWATER AREA SHOULD CONSOLIDATE AS A SINGLE LOW AND MOVE NEWD OFF THE MID ATLANTIC COAST TONIGHT...IN ADVANCE OF THE OH VALLEY MID LEVEL TROUGH. SEVERAL CLUSTERS OF THUNDERSTORMS ARE EXPECTED TODAY IN ASSOCIATION WITH THE WEAK CYCLOGENESIS AND DAYTIME HEATING WITHIN THE MOIST WARM SECTOR. THE ERN FRINGE OF THE STRONGER /30 KT/ MID LEVEL FLOW WILL OVERLAP THE WRN FRINGE OF THE WARM SECTOR THIS AFTERNOON...AND A FEW ORGANIZED MULTICELL CLUSTERS WILL BE POSSIBLE INVOF THE SURFACE FRONT. GIVEN THE MODERATE INSTABILITY /MLCAPE VALUES OF 1000-2000 J/KG/ IN THE WARM SECTOR...THE STRONGEST STORMS MAY PRODUCE STRONG/ISOLATED DAMAGING OUTFLOW WINDS. ...SRN HIGH PLAINS THIS AFTERNOON/EVENING... WEAK LOW-LEVEL UPSLOPE FLOW AND BOUNDARY LAYER DEWPOINTS IN THE 50S WILL PERSIST TODAY BENEATH NLY/NWLY MID-UPPER FLOW...AND WATER VAPOR IMAGERY SHOWS A SPEED MAX ROTATING SSEWD FROM ERN CO TOWARD EXTREME NE NM AND THE NW TX PANHANDLE. AFTERNOON TEMPERATURES FROM 68-72 F W OF THE THICKER STRATUS WILL CONTRIBUTE TO MLCAPE VALUES OF 500-1000 J/KG IN AN ENVIRONMENT WITH SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS /30-40 KT OF BULK SHEAR IN LOWEST 6 KM/. A FEW THUNDERSTORMS SHOULD DEVELOP ACROSS NE NM AND THE NW TX PANHANDLE BY MID AFTERNOON...THE STRONGEST OF WHICH COULD PRODUCE ISOLATED MARGINALLY SEVERE HAIL THROUGH THIS EVENING. ...IL/INDIANA TODAY... THE COLD CORE MID LEVEL LOW OVER IL WILL GRADUALLY EVOLVE INTO MORE OF AN OPEN WAVE AND MOVE EWD OVER INDIANA THROUGH TONIGHT. CONVECTION IS ONGOING IN ASSOCIATION WITH THE MID LEVEL COLD POOL...AND SOME ADDITIONAL DESTABILIZATION IS POSSIBLE WHERE CLOUD BREAKS ALLOW SOME SURFACE HEATING. HOWEVER...RATHER MODEST MID LEVEL LAPSE RATES /6.5 C/KM/ AND WEAK VERTICAL SHEAR APPEAR SUPPORTIVE OF ONLY MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS THIS AFTERNOON. ..THOMPSON/CROSBIE.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 19:36:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 15:36:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051935 SWODY1 SPC AC 051933 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0233 PM CDT TUE SEP 05 2006 VALID 052000Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY AREA... UPPER LOW CENTERED OVER CNTRL IL CONTINUES MOVING SLOWLY EWD. COOL MID LEVEL TEMPERATURES NEAR UPPER LOW CENTER WITH -16C AT 500 MB AND POCKETS OF SURFACE HEATING HAVE RESULTED IN MODERATELY STEEP LOW TO MID LEVEL LAPSE RATES AND MLCAPE NEAR 500 J/KG. ZONES OF ASCENT ASSOCIATED WITH SEVERAL VORTICITY MAXIMA ROTATING AROUND THE UPPER LOW WILL CONTINUE TO PROMOTE THUNDERSTORM DEVELOPMENT THIS AFTERNOON AS THE BOUNDARY LAYER DESTABILIZES. THE THERMODYNAMIC ENVIRONMENT MAY BE SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL THROUGH EARLY EVENING. ...SERN STATES... SURFACE HEATING AND BOUNDARY LAYER DEWPOINTS IN THE LOW 70S HAVE RESULTED IN MODERATE INSTABILITY WITHIN THE PRE-FRONTAL WARM SECTOR FROM PORTIONS OF GA NEWD THROUGH THE ERN CAROLINAS. HOWEVER...WEAK MID LEVEL LAPSE RATES ARE LIMITING MLCAPE TO AOB 1500 J/KG. NUMEROUS THUNDERSTORMS CONTINUE DEVELOPING ALONG THE FRONT AND WITHIN THE WEAKLY CAPPED WARM SECTOR. ISOLATED WET MICROBURSTS AND PERHAPS MARGINALLY SEVERE HAIL COULD ACCOMPANY THE STRONGER STORMS. HOWEVER...POOR LAPSE RATES AND MODEST LARGELY UNIDIRECTIONAL SWLY VERTICAL WIND PROFILES WILL LIMIT OVERALL THREAT. ...CNTRL AND SRN HIGH PLAINS... ISOLATED STORMS DEVELOPING ALONG CONVERGENCE BOUNDARY FROM SERN CO INTO THE WRN TX PANHANDLE MAY BECOME CAPABLE OF PRODUCING ISOLATED STRONG WIND GUSTS AND HAIL. SEVERE COVERAGE IS NOT EXPECTED TO BECOME SUFFICIENT TO WARRANT A SLIGHT RISK. SEE SWOMCD 1933 FOR MORE INFORMATION. ..DIAL.. 09/05/2006  From swody1 at goshenarc.org Fri Sep 8 05:46:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 01:46:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080547 SWODY1 SPC AC 080545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT FRI SEP 08 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM LOWER MI TO NERN IA... ...GREAT LAKES TO NERN IA... WEAK HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES WITHIN BASE OF DEEPER TROUGH THAT EXTENDS INTO HUDSON BAY REGION OF CANADA. AT THE SFC...DOMINANT ANTICYCLONE OVER CNTRL CANADA WILL BUILD SWD FORCING A COLD FRONT INTO NRN LOWER MI/CNTRL WI AROUND PEAK HEATING...TRAILING SWWD INTO IA. LATEST MODEL GUIDANCE SUGGEST BOUNDARY LAYER WILL ONCE AGAIN HEAT RAPIDLY DUE TO DEEP WSWLY FLOW FROM THE CNTRL PLAINS INTO WI. IT APPEARS CONVECTIVE TEMPERATURES WILL EASILY BE REACHED WITH LOWER 80S EXPECTED BY 19-20Z ACROSS THE WARM SECTOR. IN THE ABSENCE OF DEEP ASCENT ALONG SHALLOW CONVERGENT WIND SHIFT...UPDRAFTS SHOULD DEVELOP QUICKLY...BUT STRUGGLE TO MAINTAIN ORGANIZED STRUCTURES. EVEN SO...THUNDERSTORMS MAY PRODUCE HAIL QUICKLY IN THEIR LIFE CYCLE BEFORE DECAYING AND STABILIZING THE FRONTAL ZONE. GREATEST THREAT FOR DEEP CONVECTION IS ACROSS LOWER MI INTO WI...WHILE ACTIVITY SHOULD BE ISOLATED IN NATURE ACROSS IA INTO NERN NEB. LOSS OF AFTERNOON HEATING WILL PROVE DETRIMENTAL TO ANY SEVERE THREAT ALTHOUGH WEAK STORMS MAY ACCOMPANY THE BOUNDARY THROUGH THE OVERNIGHT HOURS INTO NRN IL/SRN LOWER MI. ...SWRN U.S... HIGHER PRECIPITABLE WATER CONTINUES ACROSS MUCH OF THE LOWER DESERTS OF SRN CA/AZ THIS MORNING WITH VALUES ON THE ORDER OF 1.5 INCHES MANY AREAS. WEAK UPPER TROUGHING WILL SHIFT EWD ACROSS THE 4-CORNERS REGION LATER TODAY WHICH WILL ENHANCE/SPREAD CONVECTIVE THREAT INTO ERN AZ/NM. NUMEROUS SHOWERS/THUNDERSTORMS WILL DEVELOP AHEAD OF UPPER TROUGH LATER TODAY AND A FEW OF THESE MAY PRODUCE MARGINALLY SEVERE HAIL OR PERHAPS SOME GUSTY WINDS. ..DARROW/JEWELL.. 09/08/2006  From swody1 at goshenarc.org Fri Sep 8 12:54:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 08:54:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081253 SWODY1 SPC AC 081252 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 AM CDT FRI SEP 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE UPPER MS VALLEY AND GREAT LAKES... ...SYNOPSIS... HIGH AMPLITUDE SPLIT FLOW PATTERN WILL CONTINUE TODAY AS BROAD UPPER TROUGH MOVES ESEWD ACROSS ERN CANADA AND ADJACENT PARTS OF THE UPPER MS VALLEY/GREAT LAKES...WHILE UPSTREAM TROUGH MOVES ONSHORE INTO THE PACIFIC NW TONIGHT. A WEAKER TROUGH OVER THE GREAT BASIN REGION IS FORECAST TO MOVE EWD ACROSS THE CENTRAL ROCKIES TOWARD THE CENTRAL HIGH PLAINS. AT THE SURFACE...A STRONG COLD FRONT FROM ERN ONTARIO ACROSS NRN WI/SRN MN AND SD WILL CONTINUE MOVING SEWD REACHING A ST LAWRENCE VALLEY/SRN LOWER MI/SRN IA/SRN NEB LINE BY 09/12Z. ...UPPER MS VALLEY/GREAT LAKES... PLUME OF STEEPER MID LEVEL LAPSE RATES EXTENDING FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY IS FORECAST TO PERSIST INTO THIS EVENING. THIS WILL ENHANCE INSTABILITY ALONG AND IMMEDIATELY AHEAD OF THE ADVANCING COLD FRONT WHERE SURFACE DEW POINTS OF 55-60F WILL CONTRIBUTE TO MLCAPE OF 1000-1500 J/KG. WIDELY SCATTERED CONVECTION IS LIKELY TO CONTINUE ACROSS THIS REGION THIS MORNING...WITH MORE VIGOROUS THUNDERSTORMS EXPECTED TO DEVELOP THIS AFTERNOON MAINLY ALONG THE FRONT AS DIURNAL HEATING CONTRIBUTES TO DESTABILIZATION. THE ACTIVITY MAY INITIALLY DEVELOP BY EARLY AFTERNOON FROM ERN UPPER MI/NRN LOWER MI WSWWD INTO PARTS OF WI...THEN GRADUALLY BUILD WWD THROUGH THE AFTERNOON ALONG THE FRONT INTO PARTS OF IA AND POSSIBLY NRN NEB. STRONGER MID LEVEL WINDS WILL EXTEND SWD AS FAR AS NRN/CENTRAL WI AND NRN LOWER MI WHERE DEEP LAYER SHEAR OF 25-35 KT WILL AID IN DEVELOPMENT OF ORGANIZED STORMS. A FEW SEVERE STORMS WILL BE POSSIBLE ACROSS PARTS OF THE UPPER GREAT LAKES/UPPER MS VALLEY DURING THE AFTERNOON AND EVENING WITH PRIMARY THREAT FOR LARGE HAIL AND STRONG WIND GUSTS. ...AZ/WRN NM REGION... MOST OF THE NOCTURNAL CONVECTION OVER WRN AZ AND EXTREME SERN CA HAS SLOWLY WEAKENED DURING THE LAST SEVERAL HOURS ALTHOUGH SEVERAL STRONG STORMS ARE CONTINUING NEAR YUM AND SW OF CGZ. THESE STORMS ARE EXPECTED TO MOVE SEWD AND GRADUALLY DIMINISH IN INTENSITY AFTER SUNRISE. AMPLE MOISTURE REMAINS ACROSS THE AREA WITH PRECIPITABLE WATER VALUES OF 1.25-1.50 INCHES INDICATED BY GPS WATER VAPOR SENSORS AND 12Z TUS/PHX SOUNDINGS...AND DRY AIR IN THE MID/UPPER LEVELS WILL ENHANCE CONVECTIVE INSTABILITY. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF NORTH CENTRAL/ERN AZ AND WRN NM THIS AFTERNOON AND EVENING AS THE UPPER TROUGH CONTINUES EWD. THIS CONVECTION IS EXPECTED TO MOVE EWD/SEWD THROUGH TONIGHT WITH STRONGER STORMS CAPABLE OF PRODUCING STRONG WIND GUSTS AND MARGINALLY SEVERE HAIL. ..WEISS/JEWELL.. 09/08/2006  From swody1 at goshenarc.org Fri Sep 8 19:59:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 15:59:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 082002 SWODY1 SPC AC 081959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT FRI SEP 08 2006 VALID 082000Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE GREAT LAKES REGION... ...GREAT LAKES AREA... A COLD FRONT FROM NRN LOWER MI SWWD THROUGH NRN WI AND INTO SRN MN WILL CONTINUE SWD IN ADVANCE OF A SHORTWAVE TROUGH ADVANCING SEWD THROUGH SRN ONTARIO. THE ATMOSPHERE IS DESTABILIZING IN ADVANCE OF THE FRONT AS SURFACE TEMPERATURES WARM INTO THE 80S. INSTABILITY HAS BEEN SOMEWHAT TEMPERED BY PRE-FRONTAL ELEVATED CONVECTION AND MODEST LOW LEVEL MOISTURE. HOWEVER...SURFACE HEATING AND MODERATELY STEEP LOW-MID LEVEL LAPSE RATES ARE CONTRIBUTING TO MLCAPE FROM 1000 TO 1500 J/KG. SURFACE BASED STORMS ARE EXPECTED TO INCREASE ALONG AND IN ADVANCE OF THE FRONT AS THE BOUNDARY LAYER DESTABILIZES. WLY UNIDIRECTIONAL WIND PROFILES WITH 25 TO 30 KT BETWEEN 850-500 MB AND WEAK VERTICAL SHEAR WILL SUPPORT MOSTLY MULTICELLS S OF THE FRONT. VERTICAL SHEAR NEAR AND N OF FRONT IS SUFFICIENT FOR SOME SUPERCELL STRUCTURES...BUT ACTIVITY IN POST FRONTAL ENVIRONMENT SHOULD REMAIN ELEVATED. SOME STORMS MAY EVOLVE INTO LINE SEGMENTS AND SMALL CLUSTERS AS THEY DEVELOP SEWD. ISOLATED DAMAGING WIND AND HAIL WILL BE POSSIBLE THROUGH EARLY EVENING. ...SWRN U.S.... THE ATMOSPHERE IS DESTABILIZING OVER AZ INTO WRN NM AS A RESULT OF STRONG SURFACE HEATING WITH MLCAPE FROM 500 TO 1000 J/KG. STORMS WILL CONTINUE TO DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON. ACTIVITY HAS BEEN MORE NUMEROUS OVER NM WHERE THERMODYNAMIC PROFILES HAVE BEEN MODIFIED BY ASCENT ACCOMPANYING AN EWD ADVANCING SHORTWAVE TROUGH. HOWEVER...INSTABILITY AND LAPSE RATES ARE MORE LIMITED IN THIS REGION. FARTHER W ACROSS AZ...LARGE SCALE SUBSIDENCE IN WAKE OF THE SHORTWAVE TROUGH HAS CONTRIBUTED TO DRYER MIDDLE AND HIGH LEVEL THERMODYNAMIC PROFILES. AS A RESULT...STORMS SHOULD REMAIN VERY ISOLATED. STRONG WIND GUSTS OR HAIL COULD ACCOMPANY THE STRONGER STORMS...BUT COVERAGE OF SEVERE IS EXPECTED TO REMAIN RATHER SPARSE. ..DIAL.. 09/08/2006  From swody1 at goshenarc.org Sat Sep 9 00:37:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 20:37:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090039 SWODY1 SPC AC 090036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 PM CDT FRI SEP 08 2006 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NERN NEB TO LOWER MI... LOSS OF SFC HEATING WILL ADVERSELY AFFECT ONGOING THUNDERSTORM ACTIVITY FROM NERN NEB/NRN IA INTO CNTRL LOWER MI OVER THE NEXT FEW HOURS. IN THE ABSENCE OF MEANINGFUL LARGE SCALE ASCENT...IT APPEARS WEAKENING LOW LEVEL LAPSE RATES AND STABILIZING BOUNDARY LAYER SHOULD RESULT IN FEEBLE UPDRAFTS BY 03Z. IN THE SHORT TERM...FRONTAL CONVERGENCE MAY SUSTAIN A FEW STRONGER STORMS CAPABLE OF GENERATING MARGINALLY SEVERE HAIL OR GUSTY WINDS. ...SERN CA/AZ... MAIN SHORTWAVE TROUGH AXIS HAS MOVED EAST OF THE LOWER DESERT REGIONS OF AZ THIS EVENING. WV IMAGERY SUPPORTS THIS WITH MUCH DRIER MID LEVELS AND ONLY ISOLATED THUNDERSTORM DEVELOPMENT WITHIN WNWLY FLOW REGIME. WEAK LARGE SCALE VERTICAL MOTION SHOULD NOT ENHANCE ORGANIZATIONAL POTENTIAL WITH THIS ACTIVITY AS BOUNDARY LAYER COOLS. A FEW STORMS COULD GENERATE SOME WIND OR SMALL HAIL BUT OVERALL THIS ACTIVITY SHOULD GRADUALLY DECREASE OVER THE NEXT SEVERAL HOURS. ..DARROW.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 05:53:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 01:53:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090556 SWODY1 SPC AC 090554 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT SAT SEP 09 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...NEW ENGLAND/OH VALLEY... PROGRESSIVE TROUGH OVER SERN CANADA WILL ALLOW SWLY FLOW/DEEP LAYER SHEAR TO INCREASE ACROSS THE NERN U.S. LATER TODAY. IN THE WAKE OF THIS UPPER TROUGH...SFC ANTICYCLONE WILL BUILD EWD AND A FORCE A RATHER SIGNIFICANT FRONT INTO NRN NEW ENGLAND BY 18Z...TRAILING SWWD INTO NRN OH/IND. LATEST GUIDANCE SUGGEST WARM SECTOR LAPSE RATES WILL STEEPEN THOUGH 3KM...IN EXCESS OF 8 C/KM...AS AIRMASS WARMS AND THUNDERSTORMS SHOULD DEVELOP ALONG/BEHIND WIND SHIFT AS IT ADVANCES ACROSS THE REGION. FORECAST SOUNDINGS SUGGEST INSTABILITY WILL BE SOMEWHAT LACKING WITH SBCAPE VALUES GENERALLY AOB 1000 J/KG. IT APPEARS 25-30KT ESEWD STORM MOTION CAN BE EXPECTED WITH MOST UPDRAFTS AS THEY STRUGGLE TO STAY AHEAD OF SURGING FRONTAL ZONE. GUSTY WINDS CAN CERTAINLY BE EXPECTED...ALONG WITH MARGINALLY SEVERE HAIL. IT APPEARS INSTABILITY/SHEAR WILL PROVE A BIT TOO MEAGER TO WARRANT AN ORGANIZED SEVERE EVENT ACROSS THIS REGION. ...CNTRL/SRN HIGH PLAINS... MULTIPLE VORT MAXIMA ARE NOTED WITHIN BROAD TROUGH ACROSS THE GREAT BASIN/CNTRL/SRN ROCKIES EARLY THIS MORNING. CONSIDERABLE AMOUNT OF CONVECTION HAS OCCURRED BENEATH THIS TROUGH THE LAST FEW DAYS...EXTENDING A GOOD DISTANCE DOWNSTREAM INTO THE CNTRL HIGH PLAINS REGION. THIS HAS EFFECTIVELY NEUTRALIZED LAPSE RATE ENVIRONMENT WHICH WILL LIKELY LIMIT INSTABILITY ACROSS THE HIGH PLAINS SOUTH OF FRONTAL ZONE. EVEN SO...WEAK LEE CYCLOGENESIS SHOULD OCCUR OVER NERN NM DURING THE AFTERNOON WITH A PSEUDO DRYLINE SERVING TO FOCUS POTENTIAL CONVECTIVE DEVELOPMENT. ADDITIONALLY...A WEAK LLJ SHOULD DEVELOP IN RESPONSE TO THE APPROACHING UPPER TROUGH AND THIS SHOULD AID THUNDERSTORM ACTIVITY ALONG/NORTH OF FRONTAL ZONE FROM ERN CO INTO WRN KS. A FEW STORMS ACROSS THE WARM SECTOR MAY EXHIBIT WEAK SUPERCELL CHARACTERISTICS AS BROAD VEERING PROFILES WILL FAVOR STORM ROTATION. ISOLATED HAIL OR PERHAPS A MARGINALLY SEVERE WIND GUST COULD OCCUR WITH THIS CONVECTION. ..DARROW/GUYER.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 12:55:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 08:55:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091257 SWODY1 SPC AC 091256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT SAT SEP 09 2006 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... HIGH AMPLITUDE FLOW PATTERN IS FORECAST TO PERSIST TODAY WITH PRIMARY BAND OF WESTERLIES CURVING FROM BRITISH COLUMBIA INTO CENTRAL CANADA THEN SEWD ACROSS THE UPPER GREAT LAKES/ST LAWRENCE VALLEY. A SHORT WAVE TROUGH WILL MOVE EWD FROM THE NRN GREAT LAKES ACROSS NEW ENGLAND...FORCING A STRONG SURFACE COLD FRONT SEWD ACROSS THE NERN STATES AND THE OH VALLEY. THIS BOUNDARY WILL EXTEND WWD AS A QUASI-STATIONARY FRONT INTO THE CENTRAL PLAINS. IN THE WEST...A BROAD UPPER TROUGH WITH MULTIPLE VORTICITY MAXIMA ACROSS THE GREAT BASIN/CENTRAL ROCKIES WILL PROGRESS EWD INTO CENTRAL PLAINS. SURFACE LOW PRESSURE DEVELOPING OVER SERN CO WILL MOVE SLOWLY EWD INTO KS BY THE END OF THE PERIOD. A DRY LINE IS EXPECTED TO DEVELOP SWD FROM THE LOW THIS AFTERNOON NEAR THE TX/NM BORDER. ...NEW ENGLAND INTO OH... CONVECTION ALONG/AHEAD OF THE ADVANCING COLD FRONT HAS BEEN SLOWLY INCREASING THIS MORNING FROM SRN LAKE ERIE INTO WRN PA...AND ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP NEWD ALONG THE FRONT INTO NRN NEW ENGLAND LATER THIS MORNING AND EARLY AFTERNOON. THE DEGREE OF INSTABILITY AHEAD OF THE FRONT IS EXPECTED TO BE TEMPERED BY MODEST LOW LEVEL MOISTURE /SURFACE DEW POINTS GENERALLY 55-60 F/ AND GENERALLY WEAK MID LEVEL LAPSE RATES WHICH WILL INHIBIT HEATING/DESTABILIZATION...WITH MAXIMUM MLCAPE OF 1000-1200 J/KG IN A RELATIVELY NARROW AXIS AHEAD OF THE FRONT. MODERATE WESTERLY WINDS ALOFT WITH 30-40 KT 500 MB FLOW OVER NEW ENGLAND AND NY WILL CONTRIBUTE TO SUFFICIENT SHEAR TO AID STORM ORGANIZATION. WEAKER WINDS ALOFT/VERTICAL SHEAR IS FORECAST SWWD ALONG THE FRONT INTO THE OH VALLEY. ISOLATED STRONG/SEVERE STORMS ARE POSSIBLE FROM LATER THIS MORNING THROUGH THE AFTERNOON WITH MORE INTENSE CELLS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH BY LATE THIS AFTERNOON OR EVENING AS THE FRONT GRADUALLY MOVES INTO A LESS FAVORABLE ENVIRONMENT. ...CENTRAL PLAINS/SRN HIGH PLAINS... LARGE SCALE ASCENT IN ADVANCE OF THE CENTRAL ROCKIES UPPER TROUGH COUPLED WITH LOW LEVEL WARM ADVECTION IS RESULTING IN WIDESPREAD CONVECTION FROM NERN CO INTO KS. THE EXTENSIVE CLOUD COVER AND PRECIPITATION IS EXPECTED TO INHIBIT DIURNAL HEATING TODAY AND LIMIT MLCAPE TO 500-1000 J/KG. GREATER HEATING IS EXPECTED TO OCCUR SWD ACROSS PARTS OF WRN TX AS MID/UPPER LEVEL DRYING OVERSPREADS THE SRN HIGH PLAINS FROM THE WEST. SURFACE DEW POINTS OF 55-60F AND TEMPERATURES WARMING GENERALLY INTO THE 80S WILL CREATE MLCAPE AROUND 1000 J/KG THIS AFTERNOON. VERTICAL WIND PROFILES ARE EXPECTED TO EXHIBIT STRONG DIRECTIONAL SHEAR AS 20 KT SLY/SELY LOW LEVEL WINDS VEER TO 25-30 KT WNWLY WINDS IN THE MID LEVELS...RESULTING IN 30-35 KT DEEP LAYER SHEAR ACROSS THE REGION. NEW CONVECTION MAY DEVELOP SWD ALONG THE DRYLINE THIS AFTERNOON...AS WELL AS OVER WRN KS IN THE WAKE OF CURRENT CONVECTION IN THAT AREA. ALTHOUGH INSTABILITY WILL GENERALLY BE WEAK...SUFFICIENT VERTICAL SHEAR SUGGESTS POTENTIAL FOR ISOLATED SEVERE STORMS TO DEVELOP...WITH ACTIVITY SPREADING SLOWLY EWD TOWARD CENTRAL KS AND POSSIBLY INTO WRN OK TONIGHT. ...NRN AZ/SRN UT... WIDELY SCATTERED STRONG THUNDERSTORMS ARE CONTINUING ACROSS NWRN AZ AND EXTREME SWRN UT IN ASSOCIATION WITH A VORTICITY MAX MOVING EWD ACROSS EXTREME SRN NV. CURRENT ACTIVITY IS LOCATED WITHIN AXIS OF HIGHER PRECIPITABLE WATER/INSTABILITY ACROSS NWRN AZ...WITH MOISTURE DECREASING EWD ACROSS NRN AZ BASED ON GPS WATER VAPOR SENSORS. HOWEVER...PERSISTENT LARGE SCALE ASCENT IS EXPECTED TO RESULT IN DEEP LAYER MOISTENING AHEAD OF THE VORTICITY MAX WITH CONTINUED POTENTIAL FOR ISOLATED STRONG/SEVERE STORMS TO DEVELOP EWD TOWARD THE FOUR CORNERS REGION THROUGH THIS EVENING. ..WEISS/GUYER.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 16:36:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 12:36:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091638 SWODY1 SPC AC 091636 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT SAT SEP 09 2006 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER OH VALLEY INTO NEW ENGLAND THIS AFTERNOON... A SURFACE COLD FRONT WILL MOVE SEWD ACROSS THE UPPER OH VALLEY/NY/NEW ENGLAND THIS AFTERNOON INTO EARLY TONIGHT...IN ASSOCIATION WITH A POSITIVE TILT MID LEVEL TROUGH FROM THE UPPER GREAT LAKES TO CENTRAL/SRN QUEBEC. MODIFIED MORNING SOUNDINGS YIELD ONLY MODEST WARM SECTOR INSTABILITY /MLCAPE VALUES NEAR 1000 J/KG/ WITH DAYTIME TEMPERATURES OF 75-80 F AND DEWPOINTS NEAR 60 F. ALSO...FORECAST WIND PROFILES AND LOCAL VWP OBSERVATIONS SUGGEST THAT FLOW IN THE LOWEST 2-3 KM IS UNLIKELY TO EXCEED 30 KT THIS AFTERNOON IN THE WARM SECTOR AND VERTICAL SHEAR WILL REMAIN MODEST AT BEST. DESPITE THE LIKELIHOOD OF SEVERAL THUNDERSTORM CLUSTERS INVOF THE COLD FRONT THIS AFTERNOON...THE OVERALL ENVIRONMENT ONLY APPEARS SUPPORTIVE OF A MARGINAL WIND/HAIL THREAT. ...TX PANHANDLE TO CENTRAL KS THIS AFTERNOON INTO EARLY TONIGHT... A COMPLEX MID LEVEL WAVE WITH MULTIPLE EMBEDDED SPEED MAXIMA IS MOVING SLOWLY EWD FROM THE CENTRAL/SRN HIGH PLAINS TOWARD NW OK/KS/NEB...WHILE AN MCV IS APPARENT OVER S CENTRAL NEB. WIDESPREAD CLOUDS/RAIN WILL LIKELY PERSIST TODAY FROM CENTRAL/NE KS INTO NEB IN ASSOCIATION WITH THE LOW-LEVEL WAA AND THE MCV. THOUGH INSTABILITY WILL LIKELY BE LIMITED ALONG THE DEVELOPING WARM FRONT ACROSS NRN KS...SUFFICIENT CLOUD BREAKS FROM THE S COULD RESULT IN AN ENVIRONMENT MARGINALLY SUPPORTIVE OF ROTATING STORMS. FARTHER SW...ISOLATED STORMS COULD FORM THIS AFTERNOON/EVENING ALONG THE REMNANT LEE TROUGH INTO THE TX PANHANDLE. HERE...DEEP LAYER VERTICAL SHEAR AND INSTABILITY MAY SUPPORT SOME THREAT FOR ISOLATED HAIL/WIND WITH THE STRONGER STORMS. ...AZ AREA TODAY... A COUPLE OF THUNDERSTORM CLUSTERS HAVE BEEN ONGOING THIS MORNING IN ASSOCIATION WITH A MID-UPPER LEVEL SPEED MAX MOVING OVER NW AZ. THE CONVECTION AND THE MID LEVEL WAVE BOTH APPEAR TO BE WEAKENING AS OF MID MORNING. HOWEVER...AN INFLUX OF RELATIVELY RICH LOW-LEVEL MOISTURE ACROSS CENTRAL/SRN AZ AND LOCAL STORM OUTFLOWS MAY ALLOW CONVECTION TO PERSIST NEAR THE RIM THIS AFTERNOON. ISOLATED HAIL AND STRONG WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..THOMPSON/GRAMS.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 19:54:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 15:54:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091957 SWODY1 SPC AC 091955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SAT SEP 09 2006 VALID 092000Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS AHEAD OF A FRONT FROM WRN NEW ENGLAND SWWD INTO OH... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SWRN AZ... ...UPPER OH VALLEY INTO NEW ENGLAND THIS AFTERNOON... A SURFACE COLD FRONT WAS MOVING SEWD ACROSS THE AREA AND AT MID AFTERNOON EXTENDED FROM CENTRAL ME SWWD THROUGH WRN NY AND INTO THE EXTREME NRN PORTION OF THE OH VALLEY. SEVERAL BANDS OF THUNDERSTORMS HAD DEVELOPED ALONG OR AHEAD OF THE FRONT... INCLUDING A BAND FROM NWRN PA INTO NERN OH THAT WAS ENHANCED BY THE LAKE BREEZE. MLCAPES AHEAD OF THE FRONT RANGE FROM 1000-1500 J/KG...WITH EFFECTIVE SHEAR MOSTLY 25-30 KT DUE TO UNIDIRECTIONAL WLY WINDS. RELATIVELY COLD TEMPERATURES ALOFT MAY SUPPORT A MARGINAL HAIL THREAT...3/4 TO 1 INCH SIZE...UNTIL EARLY EVENING. EVEN THROUGH THE WINDS FROM THE TOP OF THE BOUNDARY LAYER TO 300 MB ARE GENERALLY IN THE 15 TO 30 MPH RANGE...A FEW STRONG/ISOLATED SEVERE WIND GUSTS ARE POSSIBLE WITH ANY N-S ORIENTED THUNDERSTORM LINES. ...TX PANHANDLE INTO CENTRAL KS... A COMPLEX MID LEVEL TROUGH STRETCHED FROM THE NRN/CENTRAL ROCKIES EWD INTO THE CENTRAL PLAINS. WV IMAGERY SUGGESTS A WEAK UPPER LOW EMBEDDED WITHIN THE TROUGH WAS LOCATED OVER SERN WY. A HIGH LEVEL SPEED MAX AND DRIER AIR ALOFT WAS ALSO EVIDENT PUNCHING EWD FROM CO INTO WRN KS AND IS LIKELY TO REDEVELOP THE UPPER LOW TO NEAR AN MCV LOCATED NEAR IML. AT THE SURFACE...A STATIONARY FRONT EXTENDED FROM NERN CO SEWD INTO E CENTRAL KS. SOUTH OF THIS FRONT...TEMPERATURES HAD WARMED INTO THE 70S AND 80S AND WAS RESULTING IN MLCAPES FROM 1000-1500 J/KG OVER KS. THE DEEP LAYER VERTICAL SHEAR AND INSTABILITY MAY SUPPORT A THREAT FOR ISOLATED HAIL/WIND WITH THE STRONGER STORMS THROUGH THE REMAINDER OF THE AFTERNOON HOURS. ...AZ/SRN UT... ONE CLUSTER OF THUNDERSTORMS MOVED EAST OF THE PHX EARLIER TODAY ...BUT MORE STORMS HAD DEVELOPED WEST OF PHX ON AN OLD OUTFLOW BOUNDARY. THESE STORMS WERE INGESTING AN AXIS OF HIGHER INSTABILITY LOCATED ACROSS THE GILA RIVER VALLEY. WIND PROFILES IN THIS REGION WERE STRONG ENOUGH FOR ORGANIZED TSTMS AND WITH TEMPERATURES WARMING TO NEAR 90...THESE STORMS WILL HAVE A HAIL THREAT AS THEY MOVE TOWARD PHX. OTHER SCATTERED THUNDERSTORMS HAVE ALSO DEVELOPED FROM NRN AZ INTO SRN UT AND ISOLATED HAIL/STRONG WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..IMY.. 09/09/2006  From swody1 at goshenarc.org Sun Sep 10 01:00:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 21:00:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100102 SWODY1 SPC AC 100100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 01:17:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 21:17:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100120 SWODY1 SPC AC 100118 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0818 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:32:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:32:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100235 SWODY1 SPC AC 100232 DAY 1 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0932 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:39:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:39:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100242 SWODY1 SPC AC 100240 DAY 1 CONVECTIVE OUTLOOK RESENT 3 NWS STORM PREDICTION CENTER NORMAN OK 0940 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:48:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:48:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100250 SWODY1 SPC AC 100249 DAY 1 CONVECTIVE OUTLOOK RESENT 4 NWS STORM PREDICTION CENTER NORMAN OK 0949 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 03:11:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 23:11:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100314 SWODY1 SPC AC 100312 DAY 1 CONVECTIVE OUTLOOK RESENT 5 NWS STORM PREDICTION CENTER NORMAN OK 1012 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 05:52:52 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 01:52:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100555 SWODY1 SPC AC 100553 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT SUN SEP 10 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX PANHANDLE/NWRN OK INTO A PART OF SWRN KS... ...SYNOPSIS... 00Z NAM/GFS ARE IN BETTER AGREEMENT THAN THE LAST FEW RUNS OF THESE MODELS WITH RESPECT TO TIMING/AMPLIFICATION...AND INDICATE A BROAD UPPER TROUGH MOVING SLOWLY EWD ACROSS THE CENTRAL U.S. TODAY. A SURFACE LOW ACCOMPANYING THIS SYSTEM SHOULD TRACK FROM NORTH CENTRAL KS AT 12Z THIS MORNING TO NRN MO BY 12Z MONDAY. MEANWHILE...SURFACE FRONTS ARE NOT WELL DEFINED IN THE MODELS. THE MEAN COLD FRONT POSITION SHOULD EXTEND FROM NERN KS SWWD THROUGH NWRN OK INTO THE TX PANHANDLE AT THE TIME OF PEAK HEATING. ...OK AND TX PANHANDLES/NWRN OK/PART OF SW KS... SLIGHTLY STRONGER WLY MID LEVEL FLOW /UP TO 25 KT/ AND RESULTANT EFFECTIVE BULK SHEAR VALUES AROUND 30 KT ARE EXPECTED ALONG THE SRN PERIPHERY OF THE UPPER TROUGH ACROSS THIS REGION OF THE SRN PLAINS THIS AFTERNOON. MODEST MID LEVEL LAPSE RATES AROUND 6.5 C/KM EXTENDING EWD ACROSS THE SLIGHT RISK AREA AND SURFACE DEWPOINTS IN THE LOWER 60S WILL LIKELY SUPPORT AN AXIS OF MODERATE INSTABILITY /MLCAPE 1000-1500 J/KG/ BY PEAK HEATING. THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON ALONG THE EXTENT OF THE COLD FRONT AND ANY OUTFLOW BOUNDARIES LEFT OVER FROM CURRENT ACTIVITY OVER THE CENTRAL/SRN PLAINS. GREATEST SEVERE THREAT IS EXPECTED ACROSS THE SLIGHT RISK AREA WHERE MODERATE INSTABILITY WILL BE COLOCATED WITH STRONGER EFFECTIVE BULK SHEAR VALUES. SEVERE THREAT SHOULD CONTINUE INTO THE EARLY EVENING PRIOR TO BOUNDARY LAYER STABILIZATION. ...ELSEWHERE ACROSS THE SRN PLAINS TO NRN MO... MID LEVEL LAPSE RATES ARE EXPECTED TO BE WEAKER WITH EWD EXTEND INTO THE PLAINS...RESULTING IN LESS AVAILABLE INSTABILITY ALONG THE COLD FRONT...ESPECIALLY FROM NERN KS INTO MO. DESPITE THE WEAKER INSTABILITY...MODELS SUGGEST EFFECTIVE SHEAR VALUES EXCEEDING 30 KT ACROSS NERN KS/NRN MO MAY SUPPORT A GREATER SEVERE THREAT ACROSS THESE AREAS THAN POINTS FARTHER S ACROSS KS. HOWEVER...MODEL UNCERTAINTIES AND LOW CONFIDENCE IN THE POSITION OF THE COLD FRONT AT PEAK HEATING HAVE LED TO THE ISSUANCE OF BROAD 5% SEVERE PROBABILITIES FOR HAIL AND WIND EXTENDING FROM THE TX S PLAINS ACROSS CENTRAL/ERN KS TO NRN MO. ..PETERS/GUYER.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 12:40:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 08:40:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101242 SWODY1 SPC AC 101240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT SUN SEP 10 2006 VALID 101300Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF SRN HIGH PLAINS... ...SRN HIGH PLAINS TOWARDS THE MID MS RIVER VALLEY... SLOW MOVING SHORTWAVE TROUGH WILL CONTINUE MOVING ACROSS THE CENTRAL PLAINS TODAY. AT THE SURFACE...ASSOCIATED SURFACE COLD FRONT WILL CONTINUE SAGGING ESEWD ACROSS CENTRAL/ERN KS WITH TAIL END SHIFTING SWD BEFORE STALLING INTO W-CENTRAL TX/ERN NM THIS AFTERNOON. THIS SHOULD ALLOW PRIMARY SURFACE CONVERGENCE AXIS TO BECOME ESTABLISHED FROM PORTIONS OF THE CENTRAL TX PANHANDLE NEWD INTO NWRN OK LATER TODAY. 12Z SOUNDING FROM AMA INDICATED MID LEVEL LAPSE RATES REMAIN RATHER STEEP WITH 7.1 C/KM LR FROM H7 TO H5. AIR MASS SHOULD BECOME MODERATELY UNSTABLE AND WEAKLY CAPPED AS TEMPERATURES WARM TO NEAR 80F JUST AHEAD OF THE SURFACE FRONT. MID/UPPER LEVEL WLY WINDS ALONG PERIPHERY OF SLOW MOVING SHORTWAVE TROUGH SHOULD SUSTAIN SUFFICIENT CLOUD-LAYER SHEAR FOR ORGANIZED MULTICELLS/LINES WITH EXPECTED THUNDERSTORM DEVELOPMENT LATE TODAY AND THIS EVENING. ISOLATED DAMAGING WINDS AND MARGINALLY SEVERE HAIL WILL BE PRIMARY SEVERE HAZARDS WITH THIS ACTIVITY. SLY H85 FLOW AND ASSOCIATED LOW LEVEL WAA REGIME WILL REMAIN IN PLACE OVER ERN PORTIONS OF THE CENTRAL PLAINS EWD TOWARDS THE MID MS RIVER VALLEY TODAY. THIS SHOULD MAINTAIN THUNDERSTORMS ALONG THIS PORTION OF THE FRONT FOR MUCH OF THE PERIOD...AND LIMIT OVERALL HEATING/INSTABILITY. MODEST DEEP LAYER SHEAR AND MARGINAL INSTABILITY MAY SUPPORT AN ISOLATED STRONG TO MARGINALLY SEVERE THUNDERSTORM. ..EVANS/GUYER.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 19:55:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 15:55:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101957 SWODY1 SPC AC 101955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SUN SEP 10 2006 VALID 102000Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS W-CENTRAL/NW TX...ERN TX PANHANDLE...WRN OK... ...SYNOPSIS... HEIGHTS CONTINUE TO BUILD ACROSS W-CENTRAL/NWRN CONUS...AS DOWNSTREAM SHORTWAVE TROUGH NOW OVER ERN NEB...WRN IA...CENTRAL KS AND NWRN OK EJECTS SLOWLY EWD. ASSOCIATED/PRIMARY SFC LOW IS ANALYZED INVOF CENTRAL PORTION KS/NEB BORDER...AND IS EXPECTED TO MOVE OR REDEVELOP EWD TOWARD NRN MO THROUGH OVERNIGHT HOURS. TWO SFC COLD FRONTS ARE ANALYZED ATTM -- INITIAL FRONT EXTENDING SWWD FROM LOW OVER EXTREME ERN OK PANHANDLE...THEN SSWWD ACROSS ERN TX PANHANDLE...THEN SWWD TO SERN NM. SECOND/STRONGER COLD FRONTAL SURGE IS EVIDENT FROM LOW WSWWD ACROSS NWRN KS AND E-CENTRAL CO...AND SHOULD CATCH UP TO INITIAL FRONTAL ZONE ACROSS OK AND W TX NEAR END OF PERIOD OR EARLY DAY-2. ...SRN PLAINS... SHORT TERM SVR GUST/HAIL POTENTIAL IS DEVELOPING ALONG AND N OF OUTFLOW BOUNDARY WHERE INSOLATION AND SFC DEW POINTS MID-UPPER 60S HAVE BOOSTED MLCAPES TO AOA 2000 J/KG. PERSISTENT DEEP CU...TOWERING CU AND YOUNG CB HAVE BEEN SEEN ON VIS IMAGERY OVER MOTLEY/COTTLE COUNTIES TX INVOF FRONT/TROUGH/OUTFLOW BOUNDARY INTERSECTION...WHERE LOW LEVEL CONVERGENCE SHOULD BE MAXIMIZED. ACTIVITY DEVELOPING IN THIS AREA MAY SPREAD/MOVE SSEWD TOWARD BGS-ABI-MWL CORRIDOR LATER THIS AFTERNOON AND EVENING...PER SPC MESOSCALE DISCUSSION 1955. FURTHER CONVECTIVE DEVELOPMENT MAY OCCUR OVER ERN PANHANDLE AND MOVE SSEWD OR SEWD INTO DESTABILIZED OUTFLOW AIR ACROSS SERN PANHANDLE...AND PERHAPS EXTREME WRN OK. DESPITE WEAK ABSOLUTE SPEEDS IN LOW-MIDDLE LEVELS...VERTICAL SHEAR MAY BE FAVORABLE FOR AT LEAST MRGL SUPERCELL ORGANIZATION...AS WELL AS WELL-ORGANIZED MULTICELLULAR CHARACTERISTICS. RELATIVELY BACKED/ELY SFC FLOW COMPONENT WILL CONTINUE TO MAXIMIZE BOTH LOW LEVEL HODOGRAPHS AND DEEP-LAYER SHEAR ALONG AND N OF OUTFLOW BOUNDARY...WITH BOTH FDR VWP DATA AND MODIFIED RUC SOUNDINGS SHOWING 0-1 KM SRH 75-150 J/KG...AND 30-35 KT EFFECTIVE SHEAR. SVR THREAT SHOULD DIMINISH AFTER APPROXIMATELY 3-4Z...WHEN LOSS OF SFC HEATING AND INCREASING PREVALENCE OF OUTFLOW AIR SHOULD DIMINISH AVAILABLE BUOYANCY. ...E-CENTRAL PLAINS TO MID MS VALLEY... BAND OF MAXIMIZED LARGE SCALE ASCENT -- ASSOCIATED WITH MID-UPPER LEVEL SHORTWAVE TROUGH -- HAS HELPED TO MAINTAIN ENVIRONMENT FAVORABLE FOR TSTMS IN SWATH FROM SERN KS NNEWD ALONG I-35 IN NWRN MO. THIS ACTIVITY SHOULD CONTINUE TO SHIFT EWD THROUGH MO IN INCREASINGLY UNSTABLE AND WEAKLY CAPPED AIR MASS. SFC DEW POINTS HAVE MIXED INTO 50S/LOW 60S F OVER MUCH OF MO AND WRN IL AMIDST STRONG SFC HEATING...CONTRIBUTING TO FAVORABLE BOUNDARY LAYER PROFILES FOR ISOLATED STG-SVR GUSTS FROM MOST VIGOROUS CELLS. MEANWHILE...ADDITIONAL DESTABILIZATION -- SFC AND ALOFT -- IS POSSIBLE BEHIND AFOREMENTIONED CLOUD/PRECIP BAND ACROSS PORTIONS WRN/SRN KS...SWWD OVER NWRN OK. DEEP-LAYER WIND AND SHEAR PROFILES ARE FCST TO REMAIN WEAK...THOUGH LOW LEVEL HODOGRAPHS MAY BE ENLARGED E-SE OF SFC LOW AND INVOF WARM FRONT...ACROSS NERN KS AND NRN MO. ISOLATED LARGE HAIL...AND GUSTS APCHG SVR LIMITS...ARE POSSIBLE IN THESE AREAS...PRIMARILY BEFORE DARK. ..EDWARDS.. 09/10/2006  From swody1 at goshenarc.org Mon Sep 11 00:52:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 20:52:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110054 SWODY1 SPC AC 110053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT SUN SEP 10 2006 VALID 110100Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NW TX/ERN TX PANHANDLE INTO WRN OK... ...SYNOPSIS... A BROAD MID/UPPER LEVEL TROUGH WILL MOVE SLOWLY EWD ACROSS THE CENTRAL U.S. THIS FORECAST PERIOD. WATER VAPOR IMAGERY INDICATED SEVERAL SMALLER SCALE SHORT WAVE TROUGHS EMBEDDED WITHIN THE BROADER TROUGH...WITH TWO OF THE MORE WELL-DEFINED FEATURES MOVING ACROSS IA AND THE LOWER MO RIVER VALLEY AT THIS TIME. MEANWHILE...SEVERAL WEAKER IMPULSES WERE LOCATED WITHIN THE WLY MID/UPPER LEVEL FLOW REGIME FROM THE CENTRAL/SRN ROCKIES EWD INTO THE CENTRAL/SRN PLAINS. PRIMARY SURFACE LOW WAS LOCATED OVER NERN KS EARLY THIS EVENING AND WILL TRACK ENEWD OVERNIGHT INTO NRN MO. TRAILING COLD FRONT WILL SPREAD ESE ACROSS KS/OK AND SHOULD EXTEND FROM NWRN MO SWWD THROUGH ERN KS AND CENTRAL OK TO THE TX S PLAINS BY 12Z MONDAY. A WARM FRONT EXTENDED ESEWD FROM THE SURFACE LOW ACROSS CENTRAL MO INTO THE LOWER OH VALLEY. ...PARTS OF NW TX/ERN TX PANHANDLE INTO WRN OK... ASCENT AHEAD OF WEAK MID LEVEL IMPULSES TRACKING EWD INTO THE SRN PLAINS THIS FORECAST PERIOD WILL SUPPORT ONGOING CLUSTER OF STORMS EXTENDING FROM WRN OK INTO PARTS OF NW TX. WSR-88D VWP AND AREA WIND PROFILERS INDICATED A BAND OF WLY MID LEVEL FLOW AT 25-30 KT EXTENDING FROM ERN NM INTO OK...WHICH IS RESULTING IN EFFECTIVE BULK SHEAR OF 25-35 KT. AIR MASS ACROSS THE ERN TX PANHANDLE/NW TX INTO WRN OK IN ADVANCE OF THE COLD FRONT SHOULD REMAIN MODERATELY UNSTABLE THROUGH 03Z...PRIOR TO MORE PRONOUNCED BOUNDARY LAYER STABILIZATION. THUS...THE CAPE/SHEAR VALUES SHOULD REMAIN SUPPORTIVE OF ORGANIZED STRONG TO SEVERE STORMS FOR THE NEXT FEW HOURS...WITH HAIL AND STRONG WINDS BEING THE PRIMARY THREATS. AFTER 03Z...DECREASING INSTABILITY SHOULD LIMIT THE EWD EXTENT OF THE SEVERE THREAT...BUT CONTINUED ASCENT ACROSS THE SRN PLAINS SHOULD SUPPORT A CONTINUED CONVECTIVE POTENTIAL ALONG/AHEAD OF THE COLD FRONT. ...EAST CENTRAL PLAINS INTO LOWER MO RIVER VALLEY... AN AREA OF MODERATE INSTABILITY EXTENDING NEWD ALONG AND EAST OF THE COLD FRONT AND SURFACE LOW SHOULD SUPPORT A FEW MORE HOURS /UNTIL 03Z/ OF SURFACE BASED THUNDERSTORM DEVELOPMENT. STRONGER EFFECTIVE BULK SHEAR VALUES WERE LOCATED PRIMARILY NORTH OF THE SURFACE LOW/WARM FRONT...AND THUS DISPLACE NWD OF THE AXIS OF GREATER INSTABILITY. EFFECTIVE BULK SHEAR AROUND 30 KT DID EXTEND INTO NERN KS AND MAY SUPPORT A FEW ADDITIONAL STRONG TO SEVERE STORMS ACROSS ERN KS...PRIOR TO THE ONSET OF BOUNDARY LAYER COOLING. OTHERWISE...ASCENT AHEAD OF THE SHORT WAVE TROUGH MOVING ACROSS MO SHOULD MAINTAIN A POTENTIAL FOR THUNDERSTORMS OVERNIGHT FROM IA/MO SWWD INTO ERN OK. ...CENTRAL/SRN HIGH PLAINS... ASCENT AHEAD OF A COUPLE OF MID LEVEL IMPULSES TRACKING EWD ACROSS THE CENTRAL/SRN ROCKIES COMBINED WITH UPSLOPE FLOW REGIME INTO THE HIGHER TERRAIN OF ERN CO TO NERN NM SHOULD SUPPORT A FEW ADDITIONAL STORMS DURING THE EARLY EVENING. MODEST WLY MID LEVEL FLOW AT 20-25 KT ATOP ENELY WINDS IN THE LOWEST 1 KM WILL MAINTAIN SUFFICIENT DEEP LAYER SHEAR FOR ROTATING STORMS. AXIS OF WEAK INSTABILITY EXTENDING FROM AROUND DEN SEWD INTO THE SRN HIGH PLAINS WILL SUPPORT A FEW STRONG TO SEVERE STORMS THROUGH ABOUT 03Z...PRIOR TO BOUNDARY LAYER STABILIZATION WITH LOSS OF DAYTIME HEATING. ISOLATED HAIL AND STRONG WIND GUSTS ARE EXPECTED TO BE THE PRIMARY THREATS. ..PETERS.. 09/11/2006  From swody1 at goshenarc.org Mon Sep 11 05:56:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Sep 2006 01:56:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110558 SWODY1 SPC AC 110556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON SEP 11 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED BROAD MID/UPPER LEVEL TROUGH...CURRENTLY EXTENDING FROM THE UPPER MS VALLEY TO THE SRN HIGH PLAINS PER WATER VAPOR IMAGERY...WILL MOVE SLOWLY EWD ACROSS THE CENTRAL U.S. TODAY. MEANWHILE...A SHORT WAVE TROUGH...NOW MOVING SSEWD INTO ERN MT...WILL CONTINUE TO DIG SWD FROM THE NRN INTO CENTRAL HIGH PLAINS ALONG WRN PERIPHERY OF CENTRAL U.S. LARGE SCALE TROUGH. AT THE SURFACE...PRIMARY LOW OVER THE CENTRAL U.S. SHOULD BE LOCATED OVER NRN MO AT 12Z THIS MORNING...AND THEN MOVE NEWD REACHING SRN LAKE MICHIGAN REGION BY 12Z TUESDAY. TRAILING COLD FRONT WILL SPREAD E AND SE ACROSS THE MID MS VALLEY AND SRN PLAINS...AND SHOULD EXTEND FROM THE SURFACE LOW SSWWD THROUGH ERN AR TO SOUTH CENTRAL TX BY END OF THE PERIOD. ...N TX/PART OF LOWER MS VALLEY TO MID MS/LOWER OH VALLEYS... AT 12Z TODAY...AN AREA OF PRECIPITATION WITH EMBEDDED THUNDERSTORMS SHOULD BE ONGOING FROM PART OF THE OZARKS REGION NEWD TO THE MIDWEST. CLOUD COVER ASSOCIATED WITH THIS ACTIVITY MAY LIMIT SURFACE HEATING AND DESTABILIZATION ACROSS THE LOWER OH AND MID MS VALLEYS. AIR MASS IN ADVANCE OF THE COLD FRONT IS EXPECTED TO REMAIN MOIST...BUT WEAK LAPSE RATES AND/OR LIMITED SURFACE HEATING SHOULD RESULT IN GENERALLY MODEST INSTABILITY /MLCAPE AROUND 1000 J/KG/. ASCENT WITH ANY WEAK MID LEVEL IMPULSE MOVING ACROSS THIS REGION TODAY WILL PROVE FAVORABLE IN AIDING THUNDERSTORM DEVELOPMENT WITHIN A WEAKLY CAPPED AIR MASS. EFFECTIVE BULK SHEAR VALUES WILL BE MODEST /20-25 KT/...SUGGESTING MULTICELLS/CLUSTERS WILL BE POSSIBLE...BUT OVERALL WEAK FORCING AND INSTABILITY SHOULD LIMIT THE SEVERE THREAT. STORMS THAT CAN MAINTAIN UPDRAFT STRENGTH WILL HAVE THE POTENTIAL TO PRODUCE ISOLATED HAIL AND/OR STRONG WIND GUSTS. THREAT SHOULD DIMINISH THIS EVENING AS THE BOUNDARY STABILIZES WITH THE LOSS OF DAYTIME HEATING. ...ERN CO/ERN NM... DESPITE STEEP MID LEVEL LAPSE RATES EXPECTED FROM CO INTO NERN NM...LIMITED LOW LEVEL MOISTURE WITH NWD EXTENT ACROSS THIS REGION SHOULD RESULT IN MLCAPE VALUES AOB 500 J/KG. LARGE SCALE ASCENT AHEAD OF THE SWD MOVING SHORT WAVE TROUGH SHOULD PROVIDE SUFFICIENT DESTABILIZATION FOR AN ISOLATED HAIL/STRONG WIND GUST POTENTIAL ACROSS ERN CO. FARTHER S...UPSLOPE FLOW INTO PARTS OF ERN NM AND STRONG SURFACE HEATING SHOULD SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT. EFFECTIVE BULK SHEAR VALUES OVER THE CENTRAL/SRN HIGH PLAINS WILL BE SUFFICIENT FOR ORGANIZED STORMS...BUT WEAK INSTABILITY SHOULD LIMIT THE SEVERE COVERAGE. THUS...THE REASON FOR MAINTAINING LOW SEVERE HAIL/WIND PROBABILITIES. ..PETERS/GUYER.. 09/11/2006  From swody1 at goshenarc.org Wed Sep 13 00:44:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Sep 2006 20:44:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130046 SWODY1 SPC AC 130044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0744 PM CDT TUE SEP 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SRN GREAT LAKES REGION/LOWER OH VALLEY SWD INTO MS VALLEY... WATER VAPOR IMAGERY SHOWED A POSITIVELY TILTED MID/UPPER LEVEL TROUGH EXTENDING FROM THE WRN GREAT LAKES TO THE SRN HIGH PLAINS. THIS LARGE SCALE TROUGH WILL REMAIN PROGRESSIVE WITH AMPLIFICATION EXPECTED OVERNIGHT AS EMBEDDED SHORT WAVE TROUGH...NOW LOCATED OVER ERN IA...TRACKS SEWD INTO THE LOWER OH VALLEY. EARLY EVENING SURFACE ANALYSIS SHOWED AN AREA OF LOW PRESSURE JUST EAST OF ORD... WITH A COLD FRONT TRAILING SWWD TO NRN LA AND CENTRAL TX. SURFACE LOW WILL TRACK ENEWD REACHING LOWER GREAT LAKES REGION BY 12Z WEDNESDAY...WHILE THE FRONT MOVES SLOWLY EWD INTO OH/TN VALLEYS AND LOWER MS VALLEY. 45-50 KT WNWLY MID LEVEL JET OVER LOWER MO VALLEY WILL TRANSLATE ESEWD MAINTAINING STRONG DEEP LAYER SHEAR SUPPORTIVE OF ORGANIZED STORMS. HOWEVER...THE COMBINATION OF WEAK MID LEVEL LAPSE RATES AND DECREASING SURFACE BASED INSTABILITY ALONG AND AHEAD OF THE COLD FRONT ARE EXPECTED TO MINIMIZE ANY ADDITIONAL SEVERE THREAT FROM THE LOWER OH INTO LOWER MS VALLEYS. ...SWRN NM WWD TO LOWER CO RIVER VALLEY... UPPER LOW OVER FAR NRN BAJA REGION WILL MOVE SLOWLY EWD REACHING SOUTH CENTRAL AZ...ALONG THE MEXICAN BORDER BY 12Z WEDNESDAY. ASCENT DOWNSTREAM OF UPPER LOW CENTER COMBINED WITH A CONTINUED INFLUX OF LOW LEVEL MOISTURE INTO AZ/SWRN NM AND STEEP MID LEVEL LAPSE RATES SHOULD SUPPORT ADDITIONAL THUNDERSTORM DEVELOPMENT THIS FORECAST PERIOD. DEEP LAYER SHEAR IS SUPPORTIVE OF ORGANIZED STORMS PER LATEST WSR-88D VADS. HOWEVER...EXTENSIVE AREA OF CLOUDINESS ACROSS MUCH OF THIS REGION AND EVENTUAL LOSS OF DAYTIME HEATING WILL FURTHER LIMIT AVAILABLE CONVECTIVE INSTABILITY FOR ADDITIONAL STRONG TO SEVERE STORMS. THE EXCEPTION MAY BE ACROSS LOWER CO RIVER VALLEY WHERE STRONG SURFACE HEATING HAS RESULTED IN LARGE TEMPERATURE/DEWPOINT SPREADS EXCEEDING 50+ DEGREES...WITH DCAPE VALUES RANGING FROM 1300-1600 J/KG. CONVECTIVE OUTFLOW SPREADING WWD FROM STORMS NOW LOCATED IN WRN YAVAPAI COUNTY TO WRN PIMA COUNTY SHOULD HAVE THE GREATEST POTENTIAL TO PRODUCE A FEW STRONG WIND GUSTS...POTENTIALLY EXCEEDING SEVERE LEVELS INTO THIS EVENING...BEFORE THE BOUNDARY LAYER STABILIZES. ..PETERS.. 09/13/2006  From swody1 at goshenarc.org Wed Sep 13 05:55:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Sep 2006 01:55:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130556 SWODY1 SPC AC 130555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT WED SEP 13 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER OH/TN VALLEYS SWD TO GULF COAST... UPPER TROUGH CENTERED OVER THE MID MS/LOWER OH VALLEYS AT 12Z WILL TRACK NORTHEAST TOWARD THE LOWER GREAT LAKES REGION THIS FORECAST PERIOD...WITH STRONGEST UPPER FORCING SPREADING ACROSS THE UPPER OH/ TN VALLEYS. ATTENDANT COLD FRONT WILL MOVE SLOWLY EWD TODAY THROUGH THE OH/TN VALLEYS AND NRN GULF COAST. A NARROW AXIS OF MOISTURE WILL EXTEND NWD IN ADVANCE OF THE COLD FRONT...WITH HIGHEST SURFACE DEWPOINTS EXPECTED TO BE CONFINED TO THE GULF COAST STATES. WEAK MID LEVEL LAPSE RATES AND EXTENSIVE CLOUD COVER ARE EXPECTED TO RESULT IN WEAK INSTABILITY...GENERALLY BELOW 1000 J/KG...MINIMIZING THE OVERALL SEVERE THREAT. IF SURFACE HEATING TAKES PLACE IN ADVANCE OF THE COLD FRONT...THEN POCKETS OF GREATER INSTABILITY WILL BE POSSIBLE. LOW LEVEL CONVERGENCE IS EXPECTED TO BE WEAK ALONG THE FRONT...BUT THE COMBINATION OF FRONTAL LIFT AND ASCENT AHEAD OF THE SHORT WAVE TROUGH SHOULD SUPPORT THUNDERSTORM DEVELOPMENT ALONG THE PROGRESSIVE...YET SLOW MOVING COLD FRONT. ALTHOUGH DEEP LAYER SHEAR WILL BE FAVORABLE FOR STORM ORGANIZATION...GENERALLY WEAK INSTABILITY WILL LIMIT DEVELOPMENT OF SEVERE STORMS. FARTHER S... WEAK UPPER FORCING SHOULD RESULT IN LESS STORM DEVELOPMENT...THOUGH AVAILABLE WEAK INSTABILITY AND 30-35 KT OF DEEP LAYER SHEAR MAY SUPPORT A FEW STRONG TO SEVERE STORMS ...AZ/SWRN NM... UPPER LOW LOCATED OVER NRN BAJA/SWRN AZ WILL MOVE EWD TODAY REACHING WRN NM BY 12Z THURSDAY. EXTENSIVE CLOUD COVER CURRENTLY LOCATED ACROSS MUCH OF AZ INTO SWRN NM MAY RESULT IN LIMITED SURFACE HEATING AND LACK OF GREATER DESTABILIZATION THIS FORECAST PERIOD. LARGE SCALE ASCENT AHEAD OF THE UPPER LOW COMBINED WITH STEEP MID LEVEL LAPSE RATES AND SUFFICIENT LOW LEVEL MOISTURE WILL ALLOW FOR THUNDERSTORMS ACROSS CENTRAL/SRN AZ INTO SWRN NM. HOWEVER...THE THREAT FOR SEVERE STORMS SHOULD BE MINIMAL...GIVEN THE POTENTIAL FOR WEAK INSTABILITY. ..PETERS/CROSBIE.. 09/13/2006  From swody1 at goshenarc.org Wed Sep 13 12:48:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Sep 2006 08:48:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131250 SWODY1 SPC AC 131248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT WED SEP 13 2006 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL CONTINUE TO SLOWLY SHIFT EWD ACROSS THE APPALACHIANS THROUGH THE PERIOD. MODELS ARE CONSISTENT IN MOVING SURFACE LOW NOW OVER SRN MI/NRN OH EWD ACROSS THE ERN GREAT LAKES...WITH SECONDARY LOW CENTER CURRENTLY OVER SRN AL SPREADING EWD QUICKLY ACROSS THE SRN APPALACHIANS AND ALONG THE SC COAST BY THE END OF THE PERIOD. ...NERN GULF COAST TO THE COASTAL CAROLINAS... ACTIVE CLUSTER/LINE OF THUNDERSTORMS CONTINUES NEAR THE LOOP CURRENT OVER THE NERN GOM THIS MORNING...WHERE A COUPLE OF SUPERCELLS HAVE BEEN OBSERVED OFF THE FL BIG BEND COAST. MORNING SURFACE ANALYSES AND FORECAST SOUNDINGS ACROSS THIS REGION SUGGEST INSTABILITY WILL REMAIN QUITE MARGINAL INLAND TODAY WITHIN RELATIVELY WEAK DEEP LAYER SHEAR. HOWEVER...AREA VWPS AND OBSERVED HODOGRAPH AT TLH THIS MORNING INDICATE STRONG LOW LEVEL SHEAR WITH 0-1 SRH IN EXCESS OF 150 M2/S2. THE WEAK DEEP LAYER SHEAR /I.E. EFFECTIVE SHEAR AROUND 20 KT/ WILL LIMIT ANY SUSTAINED OR DEEP ROTATION. HOWEVER...GIVEN FEED OF RICH MOISTURE OFF THE GOM...AT LEAST LOW PROBABILITIES OF DAMAGING WINDS AND POSSIBLY A BRIEF TORNADO/WATERSPOUT ARE WARRANTED...ESPECIALLY NEAR THE NW-FL COAST TODAY. TONIGHT...WEAK CYCLOGENESIS ALONG THE FRONT IS FORECAST TO OCCUR INTO THE SC COASTAL PLAIN. WITH INCREASING SLY FLOW OFF THE ATLANTIC...LOW LEVELS SHOULD MOISTEN AND MAY ALLOW AIR MASS TO BECOME MARGINALLY UNSTABLE LATER TONIGHT. EFFECTIVE SHEAR AROUND 30 KT SHOULD SUPPORT SOME ORGANIZATION/LINES SHOULD MODEST INSTABILITY DEVELOP. WILL ADD LOW SEVERE PROBABILITIES INTO THIS REGION TO ACCOUNT FOR THIS. ...OH INTO THE CENTRAL APPALACHIANS... POCKET OF COLD MID LEVEL AIR /I.E. AOB -14C AT H5/ WILL OVERSPREAD THIS REGION THIS AFTERNOON...ASSOCIATED WITH WELL-DEFINED MID/UPPER LEVEL LOW NOW PROGRESSING EWD ACROSS IL/IND. THOUGH LOW LEVELS WILL BE RATHER COOL...STEEPENING MID LEVEL LAPSE RATES/COOLING ALOFT APPEAR SUFFICIENT FOR WEAK INSTABILITY THIS AFTERNOON NEAR THIS LOW CENTER. SCATTERED THUNDERSTORMS SHOULD DEVELOP...WITH THE POTENTIAL FOR HAIL WITH STRONGER STORMS THIS AFTERNOON. ...AZ... SLOW MOVING MID AND UPPER LOW WILL SHIFT ENEWD INTO THE SRN ROCKIES DURING THE PERIOD...WITH MID LEVEL DRYING LIKELY OVERSPREADING MUCH OF SRN AZ. ONGOING SHOWERS AND THUNDERSTORMS WILL LIKELY LIMIT INSTABILITY ACROSS MUCH OF THE REGION TODAY. HOWEVER...SUFFICIENT LOW LEVEL MOISTURE AND STRONGER HEATING IN CLOUD-FREE AREAS SHOULD SUPPORT MARGINAL TO MODERATE INSTABILITY THIS AFTERNOON. WHERE AIR MASS CAN DESTABILIZE...STORMS COULD PRODUCE MARGINALLY SEVERE HAIL. ..EVANS/CROSBIE.. 09/13/2006  From swody1 at goshenarc.org Tue Sep 19 00:52:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Sep 2006 20:52:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190053 SWODY1 SPC AC 190052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 PM CDT MON SEP 18 2006 VALID 190100Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...WRN SC/GA... LATEST SFC ANALYSIS SHOWS A COLD FRONT POSITIONED FROM THE OH VALLEY SWWD INTO THE LOWER MS VALLEY. A PREFRONTAL TROUGH IS LOCATED ACROSS THE SRN APPALACHIANS EXTENDING SWD ACROSS ERN GA WITH A NEARLY CONTINUOUS CONVECTIVE LINE MOVING EWD ACROSS WRN GA. RUC ANALYSIS SHOWS A WEAKLY UNSTABLE AIRMASS AHEAD OF THE LINE WITH RELATIVELY LITTLE VERTICAL SHEAR SUGGESTING ANY SEVERE THREAT SHOULD REMAIN VERY MARGINAL THIS EVENING. A BRIEF WINDOW FOR STRONG GUSTY WINDS MAY EXIST WITH BOWING SEGMENTS FOR A FEW MORE HOURS. ..BROYLES.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 05:16:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 01:16:39 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190517 SWODY1 SPC AC 190516 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1216 AM CDT TUE SEP 19 2006 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...ERN SEABOARD/FL... A COLD FRONT OVER THE APPALACHIAN MTNS THIS MORNING WILL ADVANCE SEWD INTO THE ATLANTIC COASTAL PLAINS THIS AFTERNOON. THUNDERSTORMS WILL LIKELY BE ONGOING ALONG THE FRONT AND THUNDERSTORM COVERAGE SHOULD INCREASE BY AFTERNOON AS DESTABILIZATION OCCURS. NUMEROUS THUNDERSTORMS WILL ALSO LIKELY DEVELOP ALONG A PRE-FRONTAL TROUGH ACROSS NRN AND CNTRL FL. ALTHOUGH MODEL FORECASTS SHOW WEAK VERTICAL SHEAR IN PLACE...SFC DEWPOINTS IN THE MID 70S F SHOULD ALLOW POCKETS OF MODERATE INSTABILITY TO DEVELOP. THIS SHOULD BE ENOUGH FOR STRONG WIND GUSTS WITH THE BETTER ORGANIZED LINE SEGMENTS DURING THE LATE AFTERNOON. ..BROYLES/GRAMS.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 12:25:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 08:25:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191226 SWODY1 SPC AC 191224 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0724 AM CDT TUE SEP 19 2006 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EASTWARD ACROSS THE OH/TN VALLEYS AND TOWARD THE ATLANTIC COAST THIS FORECAST PERIOD. MEANWHILE...SURFACE COLD FRONT WILL PUSH EASTWARD INTO THE CAROLINAS AND SOUTHEAST STATES. AMPLE MOISTURE AND POCKETS OF DAYTIME HEATING WILL LIKELY RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF FRONT. HOWEVER...WEAK LAPSE RATES...WARM TEMPERATURES ALOFT...AND WEAK CONVERGENCE ALONG FRONT ARE EXPECTED TO MINIMIZE INTENSITY OF CONVECTION. ISOLATED STORMS MAY PRODUCE LOCALLY GUSTY WINDS FROM NC INTO FL THIS AFTERNOON...BUT ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED. ..HART/GRAMS.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 15:51:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 11:51:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191552 SWODY1 SPC AC 191551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1051 AM CDT TUE SEP 19 2006 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EASTWARD ACROSS THE OH/TN VALLEYS AND TOWARD THE ATLANTIC COAST THIS FORECAST PERIOD. MEANWHILE...SURFACE COLD FRONT WILL PUSH EASTWARD INTO THE CAROLINAS AND SOUTHEAST STATES. AMPLE MOISTURE AND POCKETS OF DAYTIME HEATING WILL LIKELY RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF FRONT. CLUSTER OF STORMS REMAINS SEMI-ORGANIZED ACROSS THE FL PANHANDLE INTO FAR SRN GA LATE THIS MORNING. HOWEVER...WEAK FLOW THROUGHOUT THE TROPOSPHERE AND WEAK LAPSE RATES/WARM TEMPERATURES ALOFT ARE EXPECTED TO MINIMIZE OVERALL SEVERITY OF THIS CONVECTION. ISOLATED STORMS MAY PRODUCE LOCALLY GUSTY WINDS FROM INTO NRN FL/SRN GA THIS AFTERNOON...AND POSSIBLY ALONG THE FRONT INTO THE COASTAL CAROLINAS...BUT ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED. ..EVANS/GUYER.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 19:56:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 15:56:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191956 SWODY1 SPC AC 191954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0254 PM CDT TUE SEP 19 2006 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SERN VA SWWD INTO NRN FL/THE FL PANHANDLE... VERY MOIST BOUNDARY LAYER BUT WEAK MID-LEVEL LAPSE RATES CHARACTERIZE THE THERMODYNAMIC ENVIRONMENT E OF THE APPALACHIANS...AHEAD OF EWD-MOVING COLD FRONT. SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP INVOF THIS BOUNDARY...WITH MOST VIGOROUS CONVECTION NOW OCCURRING FROM FAR SERN SC INTO N FL. ALONG WITH THE GENERALLY WEAK THERMODYNAMIC ENVIRONMENT...DEEP-LAYER WIND FIELD REMAINS MARGINAL FOR ORGANIZED/SEVERE STORMS...WITH ROUGHLY UNIDIRECTIONAL FLOW GENERALLY LESS THAN 30 KT THROUGH MID-LEVELS. THOUGH A FEW STRONGER STORMS MAY PRODUCE LOCALLY STRONG GUSTS THROUGH THE AFTERNOON...OVERALL SEVERE THREAT SHOULD REMAIN LOW UNTIL ENDING COMPLETELY AS FRONT MOVES OFF THE ATLANTIC COAST THROUGH THIS EVENING. ..GOSS.. 09/19/2006  From swody1 at goshenarc.org Wed Sep 20 00:49:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 20:49:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200050 SWODY1 SPC AC 200048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT TUE SEP 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN INTERMOUNTAIN REGION... ENOUGH INSOLATION HAS OCCURRED IN RELATIVELY MOIST POST-FRONTAL AIR MASS FOR SCATTERED THUNDERSTORM ACTIVITY...BENEATH EASTERN FRINGE OF MID-LEVEL THERMAL TROUGH ACROSS PARTS OF EASTERN WASHINGTON/ OREGON INTO SOUTHWESTERN IDAHO. SOME HAIL IS POSSIBLE IN STRONGER CELLS...BUT ACTIVITY WILL PROBABLY QUICKLY WEAKEN AROUND SUNSET. WITH PRIMARY MID-LEVEL JET STREAK STILL DIGGING NEAR COASTAL AREAS OF SOUTHWEST OREGON...STRONGER FORCING IS FOCUSED IN THE BASE OF THE UPPER TROUGH. THIS WILL SPREAD ACROSS THE NORTHERN GREAT BASIN TONIGHT...AND MAY CONTRIBUTE TO ENOUGH DESTABILIZATION TO MAINTAIN AT LEAST SCATTERED THUNDERSTORM ACTIVITY AFTER DARK. CAPE IS GENERALLY WEAK...BUT THERMODYNAMIC PROFILES MAY STILL BE CONDUCIVE TO SMALL HAIL IN STRONGER ONGOING STORMS ACROSS NORTH CENTRAL/ NORTHEAST NEVADA INTO SOUTH CENTRAL IDAHO. PROFILES WITH LARGE LOW-LEVEL DEW POINT DEPRESSIONS MAY BE A BIT MORE FAVORABLE FOR LOCALIZED DOWNBURSTS...AND DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH A 50-70 KT 500 MB JET MAY MAINTAIN RISK FOR GUSTY WINDS EASTWARD INTO NORTHERN UTAH LATER TONIGHT. ...SOUTH ATLANTIC COAST STATES... PRE-FRONTAL LINE OF STORMS ACROSS EASTERN/SOUTHERN NORTH CAROLINA APPEARS TO BE AIDED BY A WEAK IMPULSE PROGRESSING OUT OF THE BASE OF A BROADER SCALE EASTERN U.S. TROUGH. ENOUGH EVAPORATIVE COOLING APPEARS POSSIBLE NEAR HEAVY RAIN CORES TO SUPPORT A LOCALIZED DAMAGING WIND THREAT...WITH ACTIVITY EMBEDDED WITHIN A MODERATE CYCLONIC FLOW FIELD. HOWEVER...THREAT HAS BEEN LIMITED BY WEAK LAPSE RATES...AND LIKELY IS DECREASING FURTHER WITH A GRADUAL LOSS OF DAYTIME HEATING. ...FLORIDA... BULK OF CONVECTIVE DEVELOPMENT...SUPPORTED BY ISENTROPIC ASCENT ASSOCIATED WITH STRONGER LOW-LEVEL WARM ADVECTION REGIME...NOW APPEARS EAST OF THE FLORIDA PENINSULA. BUT...PRE-FRONTAL FORCING WILL PROBABLY REMAIN SUFFICIENT TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS OFF THE SOUTHEASTERN GULF OF MEXICO INTO CENTRAL/ SOUTHERN PORTIONS OF THE PENINSULA INTO THE OVERNIGHT HOURS. ..KERR.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 05:37:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 01:37:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200538 SWODY1 SPC AC 200537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT WED SEP 20 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...NEB/KS/OK AND TX PANHANDLES... A PROGRESSIVE UPPER-LEVEL TROUGH EVIDENT ON WATER VAPOR IMAGERY OVER THE WRN U.S. WILL MOVE EWD AND CLOSE-OFF CROSSING THE ROCKIES TODAY. MOISTURE WILL RETURN NWD INTO THE HIGH PLAINS AHEAD OF THE APPROACHING SYSTEM BUT A CAPPING INVERSION SHOULD REMAIN IN PLACE ACROSS MOST OF THE REGION THROUGH THE AFTERNOON. THE EXCEPTION MAY BE OVER WEST TX WHERE A FEW STORMS MAY INITIATE DURING THE LATE AFTERNOON WHERE INSTABILITY AND SHEAR IS FORECAST TO BE SLIGHTLY GREATER. HOWEVER...MOST OF THE CONVECTIVE DEVELOPMENT SHOULD HOLD OFF UNTIL LARGE-SCALE ASCENT RAPIDLY INCREASES WHEN THE UPPER-LOW DRIFTS EWD AND BEGINS TO AFFECT THE HIGH PLAINS AND WEST TX IN THE 04Z TO 08Z TIMEFRAME. ALTHOUGH FORECAST SOUNDINGS SHOW STRONG ENOUGH VERTICAL SHEAR TONIGHT FOR ISOLATED SUPERCELLS...MOISTURE WILL NOT HAVE VERY LONG TO RETURN AHEAD OF THE APPROACHING SYSTEM. AS A RESULT...INSTABILITY SHOULD REMAIN RELATIVELY WEAK AS THE SYSTEM EJECTS INTO THE PLAINS TONIGHT. STEEP MID-LEVEL LAPSE RATES WILL EXIST AND ELEVATED INSTABILITY WILL BE PRESENT WHICH CONSIDERING THE STRONG ASCENT SHOULD BE FAVORABLE FOR MARGINALLY SEVERE HAIL STORMS. IF IT APPEARS LIKELY THAT INSTABILITY WILL BE GREAT ENOUGH FOR THE FORMATION OF SUPERCELLS OVER A LARGER AREA...AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...SRN AND CNTRL FL... A COLD FRONT OVER THE CNTRL FL PENINSULA THIS MORNING WILL MOVE SLOWLY SWD TODAY. A LINEAR MCS SHOULD BE ONGOING THIS MORNING ALONG THE BOUNDARY WITH THE LINE OF THUNDERSTORMS MOVING INTO SRN FL THIS AFTERNOON. FORECAST SOUNDINGS EARLY THIS AFTERNOON IN CNTRL AND SRN FL SHOW STEEP LOW-LEVEL LAPSE RATES AND RELATIVELY STRONG LOW-LEVEL WLY UNIDIRECTIONAL FLOW. THIS MAY BE ENOUGH FOR A FEW MARGINALLY SEVERE WIND GUSTS WITH THE STRONGER LINE SEGMENTS NEAR PEAK HEATING THIS AFTERNOON. ..BROYLES/GRAMS.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 12:42:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 08:42:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201243 SWODY1 SPC AC 201241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 AM CDT WED SEP 20 2006 VALID 201300Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE NORTHWARD INTO WESTERN KS... MORNING WATER VAPOR IMAGERY SHOWS POWERFUL UPPER TROUGH ROTATING ACROSS NV/UT. THIS FEATURE IS EXPECTED TO MOVE RAPIDLY EASTWARD ACROSS THE CENTRAL ROCKIES TODAY...AND INTO THE CENTRAL/SOUTHERN PLAINS TONIGHT. A VERY DYNAMIC PATTERN WILL DEVELOP ACROSS THE CENTRAL HIGH PLAINS FOR STRONG CONVECTION. THE MAIN FORECAST PROBLEM WILL BE THE QUALITY/TIMING OF LOW LEVEL MOISTURE RETURN. ...TX PANHANDLE... FULL SUNSHINE IS EXPECTED THIS AFTERNOON OVER THE TX PANHANDLE...WHERE WEAK SURFACE DRYLINE IS EXPECTED TO SLOWLY DEVELOP. WEAK LEAD IMPULSE CURRENTLY MOVING ACROSS NORTHERN AZ IS FORECAST TO APPROACH THIS REGION BY LATE AFTERNOON...PROVIDING SUFFICIENT FORCING FOR UPWARD VERTICAL MOTION FOR ISOLATED THUNDERSTORM DEVELOPMENT. SURFACE DEWPOINTS IN THE MID-UPPER 50S TO THE EAST OF THE DRYLINE...COUPLED WITH STEEP LOW/MID LEVEL LAPSE RATES SHOULD RESULT IN MLCAPE VALUES OF 500-1000 J/KG. DESPITE RELATIVELY WEAK CAPE VALUES...VERTICAL SHEAR PROFILES ARE EXPECTED TO BE QUITE FAVORABLE FOR ORGANIZED/SEVERE STORMS BY 00Z. LARGE HAIL AND GUSTY WINDS ARE EXPECTED IN STRONGEST CELLS OVER THIS REGION. ...WESTERN KS... EXIT REGION OF MID/UPPER JET WILL OVERSPREAD WESTERN KS AFTER 00Z...RESULTING IN RAPID/WIDESPREAD CONVECTIVE DEVELOPMENT. POTENTIAL FOR SEVERE STORMS IN THIS AREA IS MORE COMPLICATED DUE TO UNCERTAINTIES REGARDING MOISTURE RETURN. CURRENT INDICATIONS ARE THAT DEWPOINTS IN THE LOWER 50S WILL BE PRESENT...RESULTING IN CAPE VALUES BELOW 500 J/KG. HOWEVER...STRENGTH OF UPPER SYSTEM...STEEP MID LEVEL LAPSE RATES...AND VERY STRONG LOW LEVEL VERTICAL SHEAR SUGGEST THE THREAT OF INTENSE ELEVATED SEVERE STORMS OVERNIGHT. LARGE HAIL WILL BE POSSIBLE WITH INITIAL STORMS ACROSS WESTERN KS DURING THE LATE EVENING...BEFORE ACTIVITY BECOMES WIDESPREAD AND LESS INTENSE AFTER MIDNIGHT. ..HART/GRAMS.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 20:05:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 16:05:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 202006 SWODY1 SPC AC 202005 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CDT WED SEP 20 2006 VALID 202000Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN KS SWD ACROSS THE TX/OK PANHANDLES... ...WRN KS INTO THE TX/OK PANHANDLES... MARGINAL BOUNDARY-LAYER MOISTURE IS RESULTING IN ONLY MINIMAL SURFACE-BASED INSTABILITY THIS AFTERNOON. THOUGH A FEW ISOLATED/SURFACE-BASED STORMS MAY DEVELOP LATE THIS AFTERNOON OVER THE HIGH PLAINS...MORE WIDESPREAD STORMS ARE EXPECTED OVERNIGHT AS WARM ADVECTION ASSOCIATED WITH INTENSIFYING LOW-LEVEL JET DEVELOPS ACROSS THE AREA. DEEP-LAYER SHEAR SUPPORTIVE OF ORGANIZED STORMS WOULD SUPPORT A THREAT FOR HAIL...AND RELATIVELY DEEP MIXED LAYER THIS AFTERNOON WOULD ALSO SUPPORT A BRIEF WINDOW OF POTENTIAL FOR LOCALLY-DAMAGING WINDS. OVERNIGHT...SHEAR SHOULD INCREASE...BUT COOLING BOUNDARY LAYER -- AND THUS ELEVATED NATURE OF CONVECTION -- SUGGESTS THAT MAIN OVERNIGHT THREAT WOULD BE IN THE FORM OF MARGINAL HAIL. ...THE FOUR CORNERS REGION... THUNDERSTORMS CONTINUE ACROSS THIS REGION THIS AFTERNOON...AHEAD OF DIGGING UPPER LOW. THOUGH LOW-LEVEL MOISTURE -- AND THUS INSTABILITY -- REMAINS MINIMAL...STRONG FLOW ALOFT MAY SUPPORT A FEW ORGANIZED/SUSTAINED UPDRAFTS. RELATIVELY DEEP MIXED LAYER MAY SUPPORT A FEW STRONG GUSTS WITH THE MORE ORGANIZED CELLS...WHILE COOLING TEMPERATURES ALOFT MAY ALSO SUPPORT MARGINAL HAIL. THREAT WILL DIMINISH THIS EVENING WITH THE ONSET OF DIURNAL COOLING. ..GOSS.. 09/20/2006  From swody1 at goshenarc.org Thu Sep 21 00:53:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 20:53:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210054 SWODY1 SPC AC 210052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 PM CDT WED SEP 20 2006 VALID 210100Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF WRN KS...TX/OK PNHDL AND EXTREME NWRN OK... ...CNTRL PLAINS TO THE SRN HIGH PLAINS... WATER VAPOR IMAGERY INDICATES THAT THE UPPER LOW OVER THE GRT BASIN WAS BEGINNING TO MAKE A TURN TO THE EAST AND SHOULD MOVE TO SRN CO AND NRN NM BY 12Z. STRONGEST LARGE SCALE ASCENT ASSOCD WITH THIS SYSTEM WAS SPREADING EAST OF THE CONTINENTAL DIVIDE EARLY THIS EVENING AND WILL REACH THE SRN HIGH PLAINS AFTER 06-09Z. 00Z SOUNDINGS SUGGEST THAT MOISTENING HAS OCCURRED ON THE HIGH PLAINS...MAINLY IN THE H85-H7 LAYER...CONTRIBUTING TO MODEST DESTABILIZATION. THE MORE QUALITY MOISTURE...HOWEVER...REMAINS WELL S ACROSS DEEP S TX PER THE SATL DERIVED AND LAND BASED PWAT SENSORS. HIGH-BASED TSTMS HAVE BEEN OCCURRING ACROSS THE TX PNHDL/W TX PLAINS THIS EVENING AS THE UPPER SYSTEM BEGINS TO INTERACT WITH THE SUB-TROPICAL MOIST PLUME. STORMS MAY BECOME MORE NUMEROUS WITHIN THIS PLUME ACROSS PARTS OF OK OVERNIGHT. PRIMARY CONCERN FOR MORE ROBUST CONVECTION WILL OCCUR FROM THE TX PNHDL NWD INTO WRN KS OVERNIGHT AS THE STRONG ASCENT BEGINS TO OVERSPREAD THE INSTABILITY AXIS. TSTMS ARE EXPECTED TO FORM AFTER 06Z AND COULD BECOME SUFFICIENTLY ORGANIZED TO PRODUCE LARGE HAIL AND PERHAPS ISOLD DAMAGING WIND GUSTS. THESE STORMS WILL MOVE EWD INTO PARTS OF WRN KS AND NWRN OK BY DAYBREAK. OTHERWISE...AS THE SLY LLJ INCREASES OVERNIGHT ACROSS THE PLAINS...PROFILES WILL GRADUALLY MOISTEN AND DESTABILIZE ACROSS PORTIONS OF NRN KS AND NEB. 00Z LBF SOUNDING SHOWED A 7.8 DEG C PER KM LAPSE RATE AND SUFFICIENT CLOUD-BEARING SHEAR FOR ORGANIZED STORMS. THUS...ISOLD STRONGER CELLS WITHIN THE BANDS OF ELEVATED STORMS MAY PRODUCE LARGE HAIL. ..RACY.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 05:57:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 01:57:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210557 SWODY1 SPC AC 210556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT THU SEP 21 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS AND OZARKS... ...CNTRL-SRN PLAINS AND OZARKS... POTENT UPPER LOW CURRENTLY MOVING INTO THE SRN ROCKIES WILL SPIN EWD TO KS BY FRI AFTN...THEN DEAMPLIFY AS IT SWINGS NEWD INTO THE MO VLY BY 12Z SATURDAY. SFC LOW DEVELOPING OVER SERN CO WILL DEVELOP INTO KS ON FRI WITH A DRYLINE/FRONT SWEEPING EWD ACROSS ERN KS...CNTRL/ ERN OK AND CNTRL TX DURING THE AFTN/EVE. A WARM FRONT...MARKING THE LEADING EDGE OF MORE QUALITY BOUNDARY LAYER MOISTURE...WILL BEGIN TO LIFT NWD THROUGH ERN TX AND THE LWR MS VLY FRI AND FRI NIGHT. CONVECTION AND CLOUDS ASSOCD WITH A WARM CONVEYOR WILL BE ONGOING FROM N TX NWD INTO KS AND NEB AT THE START OF THE PERIOD. THIS CONVEYOR SHOULD SHIFT EWD INTO THE OZARKS BY AFTN...WITH POTENTIAL FOR CLEARING TO DEVELOP UPSTREAM AHEAD OF THE APPROACHING DRYLINE/ FRONT. MODIFIED GULF MOISTURE CHARACTERIZED BY SFC DEW POINTS IN THE 50S WILL ADVECT OR BE MAINTAINED ACROSS CNTRL AND ERN SECTIONS OF KS/OK THROUGH FRI AFTN. MORE ROBUST MOISTURE /DEW POINTS IN THE 60S TO LWR 70S/ WILL ARRIVE ACROSS NERN TX...SERN OK AND SWRN AR LATE FRI AFTN/EVE. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE APPROACHING SYSTEM /SWLY H5 JET 75+ KTS/ WILL TRANSLATE ACROSS KS/NRN OK WHERE INSTABILITY WILL BE TEMPERED BY MODEST MOISTURE. MAGNITUDE OF FORCING...HOWEVER...MAY COMPENSATE AND TSTMS WILL LIKELY INITIATE EARLY FRI AFTN FROM CNTRL KS SWD INTO CNTRL OK. VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS. THE STRONG FORCING WILL LIKELY RESULT IN SHORT LINE SEGMENTS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREAT AS THE STORMS MOVE INTO ERN KS AND NERN OK BY FRI EVE. THIS ACTIVITY WILL PROBABLY WEAKEN AS IT MOVES INTO MO...BUT STRONG LLJ AND STRONG MID-LEVEL FLOW MAY MAINTAIN AT LEAST AN ISOLD SEVERE THREAT OVERNIGHT INTO CNTRL/ERN MO. FARTHER S...00Z MODELS SUGGEST THAT THE SRN EXTENT OF AFTN TSTM DEVELOPMENT MAY GROW UPSCALE INTO A SMALL MCS FRI NIGHT FROM SERN OK AND NERN TX INTO AR. THIS REGION WILL BE ALONG SRN PERIPHERY OF STRONGER HEIGHT FALLS AND NRN EDGE OF RETURNING TROPICAL MOISTURE REGIME. FORECAST KINEMATIC PROFILES ARE QUITE SUPPORTIVE FOR SUPERCELLS AND ISOLD TORNADOES COULD OCCUR WITH THE MORE DISCRETE CELLS ACROSS SERN OK...EXTREME NERN TX AND PARTS OF SWRN AR. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. ..RACY/GRAMS.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 06:08:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 02:08:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210609 SWODY1 SPC AC 210608 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT THU SEP 21 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS AND OZARKS... CORRECTED FOR DAY OF WEEK ...CNTRL-SRN PLAINS AND OZARKS... POTENT UPPER LOW CURRENTLY MOVING INTO THE SRN ROCKIES WILL SPIN EWD TO KS BY THU AFTN...THEN DEAMPLIFY AS IT SWINGS NEWD INTO THE MO VLY BY 12Z FRIDAY. SFC LOW DEVELOPING OVER SERN CO WILL DEVELOP INTO KS ON THU WITH A DRYLINE/FRONT SWEEPING EWD ACROSS ERN KS...CNTRL/ERN OK AND CNTRL TX DURING THE AFTN/EVE. A WARM FRONT...MARKING THE LEADING EDGE OF MORE QUALITY BOUNDARY LAYER MOISTURE...WILL BEGIN TO LIFT NWD THROUGH ERN TX AND THE LWR MS VLY THU AND THU NIGHT. CONVECTION AND CLOUDS ASSOCD WITH A WARM CONVEYOR WILL BE ONGOING FROM N TX NWD INTO KS AND NEB AT THE START OF THE PERIOD. THIS CONVEYOR SHOULD SHIFT EWD INTO THE OZARKS BY AFTN...WITH POTENTIAL FOR CLEARING TO DEVELOP UPSTREAM AHEAD OF THE APPROACHING DRYLINE/ FRONT. MODIFIED GULF MOISTURE CHARACTERIZED BY SFC DEW POINTS IN THE 50S WILL ADVECT OR BE MAINTAINED ACROSS CNTRL AND ERN SECTIONS OF KS/OK THROUGH THU AFTN. MORE ROBUST MOISTURE /DEW POINTS IN THE 60S TO LWR 70S/ WILL ARRIVE ACROSS NERN TX...SERN OK AND SWRN AR LATE THU AFTN/EVE. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE APPROACHING SYSTEM /SWLY H5 JET 75+ KTS/ WILL TRANSLATE ACROSS KS/NRN OK WHERE INSTABILITY WILL BE TEMPERED BY MODEST MOISTURE. MAGNITUDE OF FORCING...HOWEVER...MAY COMPENSATE AND TSTMS WILL LIKELY INITIATE EARLY THU AFTN FROM CNTRL KS SWD INTO CNTRL OK. VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS. THE STRONG FORCING WILL LIKELY RESULT IN SHORT LINE SEGMENTS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREAT AS THE STORMS MOVE INTO ERN KS AND NERN OK BY THU EVE. THIS ACTIVITY WILL PROBABLY WEAKEN AS IT MOVES INTO MO...BUT STRONG LLJ AND STRONG MID-LEVEL FLOW MAY MAINTAIN AT LEAST AN ISOLD SEVERE THREAT OVERNIGHT INTO CNTRL/ERN MO. FARTHER S...00Z MODELS SUGGEST THAT THE SRN EXTENT OF AFTN TSTM DEVELOPMENT MAY GROW UPSCALE INTO A SMALL MCS THU NIGHT FROM SERN OK AND NERN TX INTO AR. THIS REGION WILL BE ALONG SRN PERIPHERY OF STRONGER HEIGHT FALLS AND NRN EDGE OF RETURNING TROPICAL MOISTURE REGIME. FORECAST KINEMATIC PROFILES ARE QUITE SUPPORTIVE FOR SUPERCELLS AND ISOLD TORNADOES COULD OCCUR WITH THE MORE DISCRETE CELLS ACROSS SERN OK...EXTREME NERN TX AND PARTS OF SWRN AR. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. ..RACY.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 12:22:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 08:22:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211223 SWODY1 SPC AC 211222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0722 AM CDT THU SEP 21 2006 VALID 211300Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF KS...OK...TX...MO...AND AR... ...CENTRAL KS/OK THIS AFTERNOON AND EVENING... IMPRESSIVE UPPER LOW OVER CO/NM WILL SURGE EASTWARD ACROSS THE CENTRAL PLAINS TODAY BEFORE WEAKENING AND LIFTING NORTHWARD LATE TONIGHT. STRONG FORCING FOR UPWARD VERTICAL MOTION HAS OVERSPREAD MUCH OF KS/OK AND NORTH TX THIS MORNING...WITH NUMEROUS SHOWERS/ THUNDERSTORMS WITHIN WARM CONVEYOR BELT. THIS ACTIVITY IS EXPECTED TO MOVE EASTWARD AND AWAY FROM KS/OK DRYLINE BY EARLY AFTERNOON. A COUPLE HOURS OF HEATING ALONG DRYLINE...COUPLED WITH NORTHWARD TRANSPORT OF MID/UPPER 50S SURFACE DEWPOINTS WILL RESULT IN A NARROW AXIS OF MODERATE INSTABILITY FROM SOUTH CENTRAL KS INTO CENTRAL OK. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL DEVELOP BY MID AFTERNOON AND MOVE EASTWARD INTO SOUTHEAST KS/EASTERN OK DURING THE EVENING. SUPERCELLS CAPABLE OF HAIL AND PERHAPS A TORNADO ARE POSSIBLE. VERTICAL SHEAR PROFILES AND FORCING ARE VERY FAVORABLE FOR ORGANIZED SEVERE STORMS. HOWEVER...NARROW INSTABILITY AXIS AND LIMITED LOW LEVEL MOISTURE ARE EXPECTED TO PRECLUDE A MORE SIGNIFICANT SEVERE WEATHER EVENT IN THIS AREA TODAY. ...EASTERN OK/WESTERN AR TONIGHT... MORNING SURFACE ANALYSIS SHOWS MAIN SURFACE WARM FRONT EXTENDING FROM SOUTH-CENTRAL TX INTO THE WESTERN GULF OF MEXICO. THIS BOUNDARY IS THE NORTHERN EXTENT OF TROPICAL MOISTURE /DEWPOINTS AOA 65F/. ALL MODEL GUIDANCE SUGGESTS THIS AIR MASS WILL RETURN RAPIDLY NORTHWARD TODAY...REACHING SOUTHEAST OK AND WESTERN AR AROUND/AFTER 00Z. THE STRONGEST FORCING ASSOCIATED WITH THE POWERFUL UPPER TROUGH WILL REMAIN NORTH OF THIS REGION. HOWEVER...IT CURRENTLY APPEARS LIKELY THAT CAPPING INVERSION WILL WEAKEN SUFFICIENTLY OVER THE ARKLATEX REGION AND SOUTHEAST OK FOR SCATTERED EVENING THUNDERSTORM DEVELOPMENT. VERY STRONG LOW LEVEL WARM ADVECTION WILL YIELD LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES FAVORABLE FOR DISCRETE SUPERCELLS AND TORNADOES /3KM HELICITY OF 200-500 M2/S2 AND 6KM SHEAR OF 40-60 KNOTS/. THIS REGION WILL BE CLOSELY MONITORED THROUGH THE DAY WITH THE POTENTIAL FOR AN UPGRADE TO MODERATE RISK IF LOW LEVEL MOISTURE/INSTABILITY TRENDS APPEAR STRONGER THAN FORECAST. ..HART/GRAMS.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 16:40:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 12:40:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211641 SWODY1 SPC AC 211639 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1139 AM CDT THU SEP 21 2006 VALID 211630Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY TNGT ACROSS PARTS OF THE CENTRAL AND SRN PLAINS.... ...SYNOPSIS... VIGOROUS MID/UPR LEVEL LOW OVER THE OK/TX PANHANDLE THIS MORNING IS FORECAST TO MOVE NEWD INTO THE MIDDLE MO VALLEY DRAGGING A NEUTRALLY THEN NEGATIVELY TILTED TROF THRU THE SRN PLAINS INTO THE MID MS VALLEY. MEANWHILE...NEXT MID/UPR LEVEL TROUGH WILL DIVE SWD THRU THE NRN PLATEAU CARVING OUT A BROAD MID/UPR LVL TROUGH OVER THE CENTRAL U.S. BY THE END OF THE PERIOD. ...CENTRAL AND SRN PLAINS... SURFACE ANALYSIS THIS MORNING SHOWS 986 LOW OVER SERN CO WITH A COLD FRONT EXTENDING SWWD/WWD ACROSS NRN NM. PRONOUNCED SFC DRYLINE/TROUGH EXTENDS FROM W CENTRAL KS SWD ALONG THE WRN OK/TX PANHANDLE BORDER THEN WSWWD THRU EXTREME W TX. A WARM FRONT REACHES FROM NW AREAS OF TX SEWD THRU THE SERN TX GULF COAST. THE NAM/NAMKF AND HI RES WRF MODELS ARE CLOSE IN AGREEMENT TO HOW FAR LOW LEVEL MOISTURE WILL ADVECT NWD LATER THIS AFTN. BUT...THE GENERAL CONCENSUS BRINGS MID 60S TO 70 DEG DEWPOINTS INTO NERN PARTS OF NERN TX. MEANWHILE...AS MID/UPR LVL TROUGH MOVES EWD ACROSS THE CENTRAL/SRN PLAINS...THIS WILL PUSH THE DRYLINE EWD INTO S CENTRAL KS SWD THRU CENTRAL OK AND N CENTRAL TX BY 21Z. STRONG LOW/MID LVL DRY INTRUSION WILL PROVIDE SUFFICIENT FORCING FOR LINE OF STG/SVR TSTMS AS THERE WILL BE HEATING/DESTABILIZATION MOSTLY ACROSS CENTRAL TX INTO EXTREME S CENTRAL OK. AIR MASS JUST AHEAD OF THE DRYLINE IS FORECAST TO ACHIEVE 1000-2000 J/KG OF SBCAPE BETWEEN 21-00Z NWD TO THE ERN RED RIVER VALLEY OF OK/TX AS PER LATEST RUC FORECAST. FEEL THIS IS MORE REALISTIC THAN THE NAM WHICH TAKES THIS INSTABILITY NWD ALONG THE I35 CORRIDOR TO THE KS/OK BORDER. WOULD EXPECT THEN THAT 1500-2000 J/KG SBCAPE WILL MAKE IT INTO SERN OK BETWEEN 00-03Z PLACING GRADIENT OF INSTABILITY ALONG NERN TX/SERN OK REGION COUPLED WITH DEEP LAYER SHEAR OF 50-55 KT. THUS...EXPECT DISCRETE SUPERCELLS TO DEVELOP BETWEEN 21-03Z IN THE VICINITY OF THE RED RIVER VALLEY OF OK/TX E OF THE I35 CORRIDOR WHERE SUFFICIENT INSTABILITY AND ENHANCED STREAMWISE VORTICITY COULD SUPPORT A FEW TORNADOES. ADDED SIGNIFICANT TORNADO PROBABILITIES TO THE FORECAST AS ANALYSIS OF NAM/RUC MODEL SNDGS INDICATE LFC/LCL VALUES BETWEEN 1000/2000M AND 0-1KM SHEAR OF 30-35 KT. AS SQUALL LINE DEVELOPS ALONG/JUST E OF SFC DRYLINE...WOULD EXPECT MAIN THREATS ASSOCIATED WITH THIS TO BE HAIL AND DAMAGING WINDS. ..MCCARTHY/GUYER.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 20:08:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 16:08:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212008 SWODY1 SPC AC 212006 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT THU SEP 21 2006 VALID 212000Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SERN OK/NERN TX/SWRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN HALVES OF KS AND OK AND NERN TX EWD TO THE MS RIVER VALLEY... ...ERN KS/ERN OK/NERN TX EWD INTO THE MID MS VALLEY REGION... BOUNDARY LAYER MOISTURE CONTINUES STREAMING NWD ACROSS THE SRN PLAINS...AHEAD OF STRONG SURFACE LOW ANALYZED OVER WRN KS ATTM. THUNDERSTORMS HAVE DEVELOPED ACROSS N CENTRAL AND NWRN KS INVOF THE UPPER LOW...ALSO CENTERED OVER WRN KS. MEANWHILE WEAKLY-CAPPED BOUNDARY LAYER CONTINUES TO DESTABILIZE WITHIN NARROW WARM SECTOR AHEAD OF DRYLINE -- WHICH EXTENDS FROM S CENTRAL KS SSWWD INTO THE TX BIG BEND REGION...AND THE WARM FRONT -- WHICH EXTENDS FROM S CENTRAL KS SSEWD ACROSS CENTRAL OK INTO E TX. AS DRYLINE PROGRESSES EWD THIS AFTERNOON AND WARM FRONT SHIFTS EWD/NEWD ACROSS SERN KS AND ERN PORTIONS OF OK AND TX...STORMS SHOULD INITIATE WITHIN DESTABILIZING BOUNDARY LAYER -- PRIMARILY FROM NERN TX NWD ACROSS THE ERN HALF OF OK INTO SERN KS. BOUNDARY LAYER CAPPING SUGGESTS THAT INITIAL STORM DEVELOPMENT IS LIKELY TO BE ISOLATED/CELLULAR. GIVEN STRONG SELY BOUNDARY LAYER FLOW WHICH INCREASES/VEERS RAPIDLY WITH HEIGHT TO SWLY AT 50 TO 70 KT AT 3 KM ACCORDING TO AREA VWPS/PROFILERS...DEVELOPING STORMS SHOULD VERY RAPIDLY ACQUIRE ROTATION. WITH MID 60S DEWPOINTS NOW AS FAR N AS THE RED RIVER VALLEY OF N CENTRAL TX/S CENTRAL OK...LOW LCLS AND STRONG LOW-LEVEL SHEAR SUGGESTS A FAIRLY SIGNIFICANT TORNADO THREAT...SPREADING EWD ACROSS NERN TX AND SERN OK THIS EVENING. THOUGH BOUNDARY LAYER IS SLIGHTLY LESS MOIST/UNSTABLE NWD INTO ERN KS...FAVORABLE SHEAR IS STILL SUPPORTIVE OF ISOLATED TORNADOES ACROSS THIS REGION. OVERNIGHT...STORMS MAY BECOME MORE LINEAR...WITH SOME INCREASE IN POTENTIAL FOR DAMAGING WINDS ALONG WITH ONGOING HAIL/TORNADO THREAT. WIND THREAT SHOULD EXTEND AS FAR E AS THE WRN HALF OF AR AND SWRN MO...WITH HAIL THREAT ASSOCIATED WITH ELEVATED STORMS EXTENDING EWD TOWARD THE MS RIVER. ..GOSS.. 09/21/2006  From swody1 at goshenarc.org Fri Sep 22 00:48:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 20:48:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220049 SWODY1 SPC AC 220048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT THU SEP 21 2006 VALID 220100Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF SERN OK...NERN TX AND SWRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL/SRN PLAINS INTO MO AND AR... ...ERN PORTION OF CENTRAL/SRN PLAINS... WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER LOW OVER NRN KS LIFTING NNEWD INTO NEB IN RESPONSE TO UPSTREAM VORTICITY MAX DIGGING SEWD ACROSS THE NRN INTERMOUNTAIN REGION. OCCLUDED SURFACE LOW NORTH OF CNK IS EXPECTED TO CONTINUE MOVING NEWD INTO ERN NEB TONIGHT. NRN PART OF SURFACE DRY LINE ARCING SWD FROM THE LOW ACROSS KS WILL MOVE INTO ERN KS...WHILE SRN PART OF DRYLINE ACROSS CENTRAL OK AND NORTH CENTRAL TX IS EXPECTED TO BECOME QUASI-STATIONARY AS STRONGEST DYNAMIC FORCING LIFTS NWD WITH TIME. A RELATIVELY NARROW WARM SECTOR HAS BECOME ESTABLISHED FROM CENTRAL/ERN TX NWD INTO ERN PARTS OF OK AND KS WITH SURFACE DEW POINTS IN THE LOW/MID 60S EXTENDING AS FAR NORTH AS NERN OK...DROPPING INTO THE 50S IN ERN KS. COLD AIR ALOFT AND STEEPER LAPSE RATES ARE LOCATED IN THE IMMEDIATE PROXIMITY OF THE NRN KS UPPER LOW...WITH PROGRESSIVELY WARMER MID LEVEL TEMPERATURES/WEAKER LAPSE RATES SWD INTO THE LOW LEVEL MOIST AXIS ACROSS ERN OK AND CENTRAL/ERN TX. THIS IS RESULTING IN MLCAPE OF AROUND 1000 J/KG OVER ERN PARTS OF OK AND TX. EARLIER TORNADIC THUNDERSTORMS OVER CENTRAL KS HAVE MOVED NWD AND WEAKENED...WHILE NEW STORMS ARE DEVELOPING FROM SERN KS ACROSS ERN OK. VAD AND PROFILERS EXHIBIT WINDS THAT VEER AND INCREASE IN SPEED WITH HEIGHT...RESULTING IN STRONG DEEP LAYER VERTICAL SHEAR OF 50-60 KT...AND SRH OF 200-400 MS/S2 IN THE LOWEST 1-3 KM AGL. THE WIND PROFILES ARE STRONGLY SUPPORTIVE OF SUPERCELL DEVELOPMENT FOR STORMS THAT CAN REMAIN DISCRETE...AND THE THREAT FOR TORNADOES WILL BE ENHANCED BY RELATIVELY LOW LCL HEIGHTS AND FAVORABLE SHEAR/SRH IN THE LOWEST 1 KM. MODEL GUIDANCE FROM RUC...NAM AND SREF AGREE WITH OBSERVATIONAL DATA SHOWING FOCUS ON THE SERN OK/NERN TX/SWRN AR REGION FOR AN INCREASED SEVERE POTENTIAL THROUGH THE EVENING HOURS AND THE HIGHEST SEVERE PROBABILITIES/MODERATE RISK REGION WILL BE MAINTAINED OVER THIS AREA. STORMS ARE LIKELY TO SPREAD NEWD INTO MO AND AR DURING THE OVERNIGHT HOURS...CONSOLIDATING INTO ONE OF MORE MCS/S ARE THEY MOVE INTO A REGION OF INCREASINGLY ELEVATED INSTABILITY. ALTHOUGH THREAT FOR TORNADOES AND DAMAGING WIND GUSTS IS EXPECTED TO DIMINISH LATER TONIGHT...POTENTIAL FOR ISOLATED LARGE HAIL WILL LIKELY CONTINUE THROUGH THE NIGHT ACROSS MO AND PARTS OF CENTRAL/ERN AR. ..WEISS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 05:48:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 01:48:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220549 SWODY1 SPC AC 220548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1248 AM CDT FRI SEP 22 2006 VALID 221200Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER AR...SRN/ERN MO...AND CENTRAL/SRN IL... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK OVER THE MIDDLE MS AND LOWER OH VALLEYS SWWD INTO NERN TX... ...SYNOPSIS... HIGH AMPLITUDE ENERGETIC FLOW PATTERN IS FORECAST TO CONTINUE THROUGH THE PERIOD AS CENTRAL PLAINS OCCLUDED UPPER LOW LIFTS NWD TOWARD SD AND BEGINS TO WEAKEN...AS UPSTREAM SHORT WAVE TROUGH OVER THE NRN INTERMOUNTAIN REGION DIGS SEWD INTO THE GREAT BASIN. THIS WILL RESULT IN A STRONG MID/UPPER LEVEL JET STREAM BECOMING ESTABLISHED FROM THE NRN PARTS OF AZ/NM ACROSS KS/OK AND THE MIDDLE MS VALLEY TODAY. AT THE SURFACE...COMPLEX PATTERN IS FORECAST TO EVOLVE AS OCCLUDED LOW LIFTS NWD TOWARD ERN SD/SWRN MN...WITH A COLD FRONT ARCING SWD FROM THE LOW INTO THE LOWER MO RIVER VALLEY THEN SWWD INTO THE SRN HIGH PLAINS. THE COLD FRONT IS FORECAST TO MOVE SEWD ACROSS THE SRN PLAINS REGION DURING THE NIGHT. IN ADVANCE OF THE COLD FRONT...A DRY LINE IS EXPECTED TO BE LOCATED FROM ERN KS/WRN MO SWD ACROSS ERN OK INTO CENTRAL TX. ...IL/MO/AR AREA... ...SIGNFICANT SEVERE THREAT EXPECTED TODAY... STRONG NOCTURNAL CONVECTION OVER PARTS OF MO AND AR IS EXPECTED TO MOVE EWD/NEWD DURING THE EARLY MORNING HOURS AND POSSIBLY CONTINUE INTO THE MS VALLEY PRIOR TO 18Z. THE MORNING ACTIVITY IN THE MIDDLE MS VALLEY WILL LIKELY REMAIN BELOW SEVERE LEVELS AS MOISTURE AND INSTABILITY WILL BE MARGINAL...ALTHOUGH THE STORMS MOVING INTO THE MID SOUTH REGION MAY HAVE POTENTIAL TO PRODUCE MARGINALLY SEVERE HAIL. LOW LEVEL MOISTURE IS EXPECTED TO INCREASE NWD IN THE WAKE OF THE MORNING CONVECTION. SURFACE DEW POINTS OF 65-70F ARE CURRENTLY OVER ERN OK INTO SRN/ERN TX AND LA AND MODEL GUIDANCE INDICATES THAT MOISTURE WILL SURGE NWD TOWARD THE MIDDLE MS VALLEY DURING THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH RESIDUAL CLOUDS AND OCCASIONAL CONVECTION WILL INHIBIT DIURNAL HEATING ACROSS PARTS OF THIS REGION...STRONGER HEATING IS LIKELY WHERE BREAKS IN THE CLOUD COVER DEVELOP...AND ALONG THE WRN PORTIONS OF THE LOW LEVEL MOIST AXIS FROM ERN OK/WRN AR INTO WRN MO/IA. THIS WILL ENHANCE DESTABILIZATION WITH MLCAPE RANGING FROM 1500-2000 J/KG OVER AR INTO SRN MO TO AROUND 1000 J/KG FROM NRN MO INTO CENTRAL IL. MULTIPLE BANDS OF CONVECTION ARE EXPECTED TO DEVELOP DURING THE AFTERNOON FROM PARTS OF ERN OK/WRN OK NNEWD INTO MO AND IL WITHIN A WEAKLY CAPPED ENVIRONMENT. MODEL FORECAST SOUNDINGS INDICATE WINDS WILL VEER AND STRENGTHEN WITH HEIGHT AS 40-50 KT SSWLY LOW LEVEL FLOW VEERS TO WLY/SWLY AT 50-75 KT ACROSS AN EXPANSIVE WARM SECTOR. THIS RESULTS IN VERY STRONG DEEP LAYER SHEAR /50-60 KT IN THE LOWEST 6 KM/ INDICATING A LIKELIHOOD FOR PERSISTENT SUPERCELLS TO DEVELOP. LOW LEVEL SHEAR WILL ALSO BE VERY STRONG WITH 0-1 KM SRH OF 200-400 M2/S2. GIVEN THE ANTICIPATED LOW LCL HEIGHTS AND POTENTIAL FOR DEVELOPMENT OF DISCRETE STORMS AND EMBEDDED SUPERCELLS WITHIN SHORT LINE SEGMENTS...THERE IS A THREAT FOR A FEW STRONG TORNADOES TO DEVELOP...IN ADDITION TO DAMAGING WIND GUSTS AND LARGE HAIL. THIS ACTIVITY WILL SPREAD NEWD THROUGH THE EVENING HOURS ACROSS THE MIDDLE MS VALLEY INTO THE LOWER OH VALLEY. ..WEISS/GRAMS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 12:47:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 08:47:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221248 SWODY1 SPC AC 221246 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 AM CDT FRI SEP 22 2006 VALID 221300Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK AND MUCH OF AR INTO PARTS OF MO AND IL... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM N TX INTO THE OH VLY... ...SYNOPSIS... UNSEASONABLY STRONG CLOSED LOW NOW NEARING FSD EXPECTED TO DRIFT N OR NNW THROUGH THE PERIOD AS UPSTREAM DISTURBANCE IN BROAD CYCLONIC FLOW MOVES FROM NRN UT TO ERN CO TODAY...AND THEN TURNS E/NE INTO KS/NEB TONIGHT/EARLY SATURDAY. THIS PATTERN WILL MAINTAIN AND LATER STRENGTHEN BELT OF FAST WSW FLOW IN PLACE ACROSS THE CENTRAL U.S. AT LOWER LEVELS...SURFACE LOW IN NW IA SHOULD LIFT SLOWLY N AND FURTHER OCCLUDE. ASSOCIATED COLD FRONT WILL CONTINUE SE ACROSS KS TODAY AND INTO NRN/WRN OK EARLY SATURDAY. DIFFUSE WARM FRONT NOW EXTENDING SE ACROSS IA INTO WRN KY SHOULD REDEVELOP N AS NOCTURNAL BOUNDARY LAYER MIXES OUT AND ELEVATED WARM/MOIST LAYER MIXES DOWNWARD. COMPLICATING THE PICTURE WILL BE PRESENCE OF OUTFLOW LEFT BY OVERNIGHT STORMS IN THE LWR MS VLY/OZARKS. LOW LEVEL DESTABILIZATION EXPECTED TO SPREAD MOST RAPIDLY NEWD ALONG WRN SIDE THE OUTFLOW INTO CNTRL/SRN MO AND WRN IL. FARTHER W...DRY LINE NOW EXTENDING FROM CNTRL MO THROUGH NE OK TO CNTRL TX MAY MIX SLIGHTLY E TODAY BEFORE BECOMING STATIONARY AND RETROGRESSING WWD TONIGHT AS UT/CO IMPULSE CONTINUES E...AND ASSOCIATED SURFACE WAVE STRENGTHENS OVER THE TX PANHANDLE. ...ERN OK/OZARKS INTO MID MS VLY... ...SIGNIFICANT SEVERE THREAT EXPECTED TODAY THROUGH EARLY SATURDAY... PERSISTENT AREA OF OVERNIGHT STORMS LIKELY WILL DELAY LOW LEVEL DESTABILIZATION OVER PARTS OF THE LWR TN...LWR OH AND MID MS VLYS TODAY AS ASSOCIATED VORT LOBE NOW ROUNDING SE QUADRANT OF SD UPR LOW CONTINUES NEWD. REGIONAL VWP/PROFILER DATA...AND SATELLITE/GPS MOISTURE DATA NEVERTHELESS INDICATE THAT SUBSTANTIAL MOISTENING HAS OCCURRED OVERNIGHT IN THE 925-850 MB LAYER OVER AR/WRN TN AND PARTS OF MO IN RESPONSE TO PERSISTENT 40+ KT SWLY LLJ. THIS MOISTURE LIKELY WILL CONTINUE TO SPREAD NEWD THROUGH THE PERIOD...AND SHOULD MIX TO THE SURFACE BY THIS AFTERNOON ACROSS THE SE HALF OF MO AND CNTRL/SRN IL. BY TONIGHT AND EARLY SATURDAY...EXPECT THAT LOW LEVEL MOISTURE WILL ALSO SPREAD NE INTO ERN OK AS NEW LLJ DEVELOPS DOWNSTREAM FROM APPROACHING UT/CO DISTURBANCE. COMBINATION OF MODERATE TO STRONG HEATING ON WRN/SRN EDGE OF CONVECTIVE OUTFLOW/DEBRIS...AND CONVERGENCE ALONG ASSOCIATED OUTFLOW BOUNDARIES/DRY LINE...LIKELY TO RESULT IN SUFFICIENT DESTABILIZATION/LIFT TO SUPPORT STORM DEVELOPMENT IN WEAKLY CAPPED ENVIRONMENT BY EARLY TO MID AFTERNOON FROM ERN OK/WRN AR NEWD INTO MO/IL. WHILE SOME MID LEVEL WARMING MAY OCCUR IN WAKE OF AFOREMENTIONED VORT LOBE...MLCAPE SHOULD REACH 1500-2000 J/KG OVER AR AND SRN MO...AND 1000 TO PERHAPS 1500 J/KG ACROSS THE REMAINDER OF MO INTO CENTRAL IL. OVERALL SETUP WITH INCREASINGLY BROAD...MOIST...AND WEAKLY CONVERGENT WARM SECTOR SURMOUNTED BY STRONG SWLY MID LEVEL FLOW SUGGESTS PROBABLE DEVELOPMENT OF MULTIPLE BANDS OF STORMS. LONG HODOGRAPHS WITH SUBSTANTIAL LOW LEVEL VEERING /40+ KT SSWLY LOW LEVEL JET BENEATH 50-70 KT WSWLY MID LEVEL FLOW/ SHOULD SUPPORT SCATTERED PERSISTENT SUPERCELLS WITH STRONG LOW LEVEL ROTATION. COUPLED WITH LOW LCL HEIGHTS AND BETTER THAN AVERAGE LIKELIHOOD FOR DISCRETE STORMS AND/OR EMBEDDED SUPERCELLS WITHIN SHORT LINE SEGMENTS...A THREAT WILL EXIST FOR A FEW STRONG AND POSSIBLY LONG-TRACKED TORNADOES. OTHER ACTIVITY MAY YIELD LOCALLY DAMAGING WIND AND...MAINLY IN THE WRN HALF OF THE MODERATE RISK AREA...SEVERE HAIL. THE STORMS SHOULD SPREAD NE THROUGH THE EVENING ACROSS THE MID MS AND LWR OH VLYS. OTHER SEVERE STORMS MAY FORM LATER TONIGHT THROUGH EARLY SATURDAY INVOF RETROGRESSING DRY LINE AND ACCELERATING COLD FRONT IN SE KS/ERN OK AND PERHAPS N TX. THESE STORMS MAY REMAIN SEVERE AS THEY MOVE/DEVELOP NE INTO PARTS OF MO AND WRN AR SATURDAY MORNING. ..CORFIDI/GRAMS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 15:53:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 11:53:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221553 SWODY1 SPC AC 221552 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1052 AM CDT FRI SEP 22 2006 VALID 221630Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK AND MUCH OF AR INTO PARTS OF MO/IL AND FAR WRN KY/TN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM N TX INTO THE OH RIVER VALLEY... RATHER COMPLEX FORECAST TODAY AS SPECIFIC TIMING FOR GREATEST SEVERE THREAT STILL UNCERTAIN. EXTREME SHEAR WILL REMAIN IN PLACE OVER A LARGE PART OF THE CENTRAL U.S...WITH MOST FOCUSED INTENSE SHEAR REMAINING FROM THE ARKLATEX REGION NEWD ACROSS THE MID MS/LOWER OH RIVER VALLEYS. THIS INTENSE SHEAR WILL OVERSPREAD A VERY MOIST BOUNDARY LAYER AS 65+F SURFACE DEW POINTS ADVECT NNEWD INTO CENTRAL/NRN IL. OVERALL SETUP REMAINS QUITE FAVORABLE FOR AN OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES ACROSS A LARGE PART OF THE CENTRAL U.S. ...THROUGH 20Z... OUTFLOW BOUNDARY/EFFECTIVE TROPICAL WARM FRONT REMAINS FAIRLY WELL DEFINED AT 15Z FROM WRN TN WSWWD INTO SERN-E-CENTRAL OK...AND MORNING SOUNDINGS WITHIN MOIST WARM SECTOR INDICATE LITTLE OR NO CAPPING WITH TEMPERATURES IN THE LOWER 80S. VWPS AND SHEAR ANALYSES INDICATE VERY FAVORABLE LOW AND DEEP LAYER SHEAR FOR TORNADIC SUPERCELLS...THOUGH OVERALL FOCUS FOR DEEP ASCENT APPEARS DIFFUSE FOR MUCH OF THE DAY . HOWEVER WITH INTENSE LOW PERSISTING OVER THE MID MO/SWRN MN...SWLY LLJ WILL REMAIN IN PLACE INTO THE MID SOUTH /H85 WINDS AROUND 40-45 KT/. THUS...ISOLATED TORNADIC SUPERCELLS MAY EVOLVE THROUGH THE DAY OVER AR INTO THE LOWER OH RIVER VALLEY. ACTIVITY WILL MOST LIKELY KEEP DEVELOPING WITHIN WARM AIR ALONG EDGE OF STEEPER LAPSE RATES OVER ERN OK...WRN/CENTRAL AR AND MOVE QUICKLY ENEWD INTO THE MID SOUTH. NEWD EXTENT OF THREAT FROM AFTERNOON ACTIVITY WILL BE HINDERED BY PERSISTENT CONVECTION/CLOUDS NOW OVERSPREADING SERN MO AND THE LOWER OH RIVER VALLEY. ...LATER TODAY AND OVERNIGHT... MORE VIGOROUS DEVELOPMENT CAN BE EXPECTED DURING THE MID TO LATE AFTERNOON FROM PORTIONS OF NERN TX/NWRN LA/ERN OK INTO THE MID MS RIVER VALLEY ALONG STRENGTHENING LOW LEVEL CONVERGENCE NEAR INTENSIFYING SURFACE TROUGH/FRONT. MODEL FORECASTS CONTINUE TO DEVELOP AXIS OF MODERATE INSTABILITY WITHIN VERY MOIST BOUNDARY LAYER INTO CENTRAL MO. IN ADDITION...SWLY LLJ WILL INCREASE LATE TODAY AND THIS EVENING AS UPSTREAM IMPULSE DIGS SEWD INTO THE CENTRAL ROCKIES AND LOW LEVEL TROUGH BECOMES BETTER DEFINED. THIS SHOULD MAINTAIN A THREAT OF STRONG TORNADOES AS SUPERCELLS AND SMALL BOW ECHOES EVOLVE AND RACE ENEWD INTO/ACROSS THE MID MS RIVER VALLEY LATER TODAY/OVERNIGHT SEVERE THREAT MAY OCCUR IN SEVERAL BANDS ACROSS WARM SECTOR GIVEN THE VERY WEAK INHIBITION...WITH DEVELOPMENT CONTINUING/BACK-BUILDING TO THE WEST AHEAD OF EWD MOVING NE-SW ORIENTED SURFACE TROUGH/FRONT. ..EVANS/CROSBIE.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 19:57:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 15:57:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221958 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT FRI SEP 22 2006 VALID 222000Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS THE SERN 2/3 OF MO...ERN OK/THE NRN 2/3 OF AR...WRN TN...WRN KY...AND THE SRN 2/3 OF IL... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN TX EWD INTO THE TN VALLEY...AND NWD TO THE SRN UPPER GREAT LAKES REGION... ...NERN TX/ERN OK ACROSS THE MID MS/TN/LOWER OH VALLEYS... BOUNDARY LAYER MOISTURE CONTINUES STREAMING NWD ACROSS THE MS/LOWER OH VALLEY REGIONS...WITH MODERATE INSTABILITY /1000 TO 1500 J/KG MEAN-LAYER CAPE/ NOW AS FAR N AS CENTRAL IL. SUPERCELL STORMS ARE ONGOING ACROSS PARTS OF ERN MO INTO NRN AR...AS WELL AS ACROSS PARTS OF NERN MS/NRN AL WITHIN VERY MOIST/DESTABILIZING WARM SECTOR. ADDITIONAL CONVECTIVE DEVELOPMENT IS BEGINNING W OF ONGOING STORMS...FROM ERN OK/NWRN AR INTO CENTRAL MO/W CENTRAL IL...ALONG WRN FRINGES OF MDT RISK AREA. SHEAR AND INSTABILITY COMBINATION WILL REMAIN VERY FAVORABLE FOR LONG-LIVED SUPERCELL STORMS TODAY AND TONIGHT. EXPECT SEVERAL WAVES OF STORMS TO MOVE ACROSS THE MDT RISK AREA...AS FRONT REMAINS W OF THIS REGION AND LOW-LEVEL JET REDEVELOPS THIS EVENING IN RESPONSE TO THE NEXT MID-LEVEL SPEED MAX MOVING OUT OF THE SRN ROCKIES. ALONG WITH THREAT FOR DAMAGING WINDS AND HAIL...UPPER 60S TO LOW 70S DEWPOINTS AND A FURTHER INCREASE IN LOW-LEVEL SHEAR THIS EVENING OVERNIGHT WILL SUPPORT A CONTINUED THREAT FOR STRONG -- AND POTENTIALLY LONG-TRACK -- TORNADOES. WIDESPREAD SEVERE THREAT IS EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD. ONGOING CLUSTERS OF SUPERCELLS -- AND ACCOMPANYING SEVERE WEATHER POTENTIAL -- WILL CONTINUE SPREADING EWD/NEWD ACROSS MO/IL/AR...WITH POTENTIAL FOR CONTINUED STORM DEVELOPMENT EXPECTED THROUGH THE END OF THE PERIOD ACROSS WRN PORTIONS OF THE RISK AREA AS COLD FRONT APPROACHES. ..GOSS.. 09/22/2006  From swody1 at goshenarc.org Sat Sep 23 01:08:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 21:08:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230109 SWODY1 SPC AC 230107 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0807 PM CDT FRI SEP 22 2006 VALID 230100Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK INTO PARTS OF THE LOWER AND MIDDLE MS VALLEY AND WRN TN VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SRN PLAINS THROUGH PARTS OF THE MIDDLE AND LOWER MS VALLEY...TN AND OH VALLEYS AND GREAT LAKES... ...ERN OK THROUGH LOWER MS VALLEY AND WRN OH VALLEY... THIS EVENING A COLD FRONT EXTENDS FROM NRN MO SWWD THROUGH THE OK AND TX PANHANDLES. THIS FRONT WILL CONTINUE SEWD TONIGHT. A DRYLINE EXTENDS FROM W CNTRL TX NEWD THROUGH ERN OK INTO ERN KS WHERE IT INTERSECTS THE COLD FRONT. THIS BOUNDARY WILL RETREAT NWWD INTO CNTRL OK TONIGHT IN RESPONSE TO BACKING AND STRENGTHENING LOW LEVEL FLOW. NUMEROUS SUPERCELLS CONTINUE DEVELOPING FROM ERN OK...NRN AR INTO SRN IL...WRN KY AND WRN TN. THE LOW LEVEL JET WILL INTENSIFY FROM ERN OK...NRN TX INTO THE LOWER MS VALLEY THIS EVENING. THIS WILL OCCUR AS SURFACE LOW DEVELOPS OVER OK ALONG SEWD ADVANCING FRONT IN RESPONSE TO A MID LEVEL JET ADVANCING INTO THE SRN HIGH PLAINS. LOW LEVEL THETA-E ADVECTION AND LIFT AUGMENTED BY THE LOW LEVEL JET WILL CONTINUE TO ENHANCE THUNDERSTORM DEVELOPMENT IN CORRIDOR FROM ERN OK THROUGH NRN AR...INTO WRN KY AND NWRN TN. LOW LEVEL HODOGRAPHS AND DEEP LAYER SHEAR WILL REMAIN FAVORABLE FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES AND TORNADOES. MOREOVER...THESE STORMS SHOULD REMAIN IN A MORE FAVORABLE POSITION FOR UNINTERRUPTED MOIST UNSTABLE LOW LEVEL INFLOW. LARGE HAIL AND DAMAGING WIND MAY ALSO ACCOMPANY THE STRONGER STORMS. SOME THREAT FOR ISOLATED TORNADOES EXIST AS FAR EAST AS WRN PORTIONS OF THE OH VALLEY. HOWEVER...THE TORNADO THREAT DIMINISHES WITH ERN EXTENT INTO THIS REGION DUE TO LIMITED INSTABILITY. THE FRONT WILL EVENTUALLY INTERCEPT THE RETREATING DRYLINE FROM W CNTRL TX INTO CNTRL OK AND SERN KS LATER TONIGHT. AS THIS OCCURS ADDITIONAL STORMS WILL LIKELY DEVELOP. MUCH OF THIS ACTIVITY WILL PROBABLY EVOLVE INTO LINES. HOWEVER VERTICAL SHEAR PROFILES WILL SUPPORT EMBEDDED ORGANIZED STORMS STRUCTURES WITHIN THE LINE INCLUDING SUPERCELL AND BOW ECHOES. ..DIAL.. 09/23/2006  From swody1 at goshenarc.org Wed Sep 27 05:45:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 01:45:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270545 SWODY1 SPC AC 270544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT WED SEP 27 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST SWWD ACROSS THE LWR OH VLY TO THE OZARKS... ...SYNOPSIS... A POTENT NRN STREAM WILL CONTINUE TO DIG SEWD AND BEGIN TO CARVE OUT A COLD LONGWAVE TROUGH ACROSS THE ERN TWO-THIRDS OF THE COUNTRY WED. THE LEAD IMPULSE MOVING ACROSS THE UPPER MS VLY EARLY WED WILL QUICKLY TRANSLATE NEWD INTO SERN CANADA AS A MORE POTENT DISTURBANCE DIGS SEWD FROM SRN ALBERTA INTO THE DAKS AND MID-MS VLY WED AND WED NIGHT. IN THE LWR LVLS...WEAK COLD FRONT ASSOCD WITH THE FIRST WAVE WILL SETTLE ACROSS THE GRTLKS...MIDWEST AND SRN PLAINS BY WED NOON. AS THE STRONG IMPULSE DIGS SEWD...A POLAR FRONT WILL SURGE SEWD...REACHING THE WEAKER FRONT LATE WED AFTN...THEN SWEEP SEWD ACROSS THE GRTLKS...OH VLY...OZARKS AND SRN PLAINS BY 12Z THU. ...MIDWEST SWWD INTO THE LWR OH VLY AND OZARKS... AS THE LEAD WAVE SWINGS E THEN NEWD THROUGH THE CNTRL GRTLKS...A BAND OF CONVECTION WILL ACCOMPANY THE ASSOCD FRONT ACROSS THE CNTRL GRTLKS FROM WED MORNING INTO THE EARLY AFTN. THIS ACTIVITY SHOULD MOSTLY BE SUB-SEVERE...BUT GUSTY WINDS AND PERHAPS SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. MAIN SEVERE THREAT WILL OCCUR FROM MID-LATE WED AFTN INTO THE NIGHT FROM THE MIDWEST SWWD TO THE OZARKS. SWLY LOW-LVL FLOW WILL TRANSPORT/MAINTAIN LOW-MID 50S SFC DEW POINTS NEWD ALONG/AHEAD OF THE WEAKER FRONT THROUGH WED AFTN. BOUNDARY LAYER SHOULD HEAT RAPIDLY AND CONTRIBUTE TO MLCAPES RANGING FROM 500 J/KG ACROSS SERN LWR MI TO 1500 J/KG IN THE LWR OH VLY AND OZARKS. HEIGHTS WILL GRADUALLY FALL THROUGHOUT THE DAYTIME...BUT STRONGEST FALLS WILL OCCUR BY LATE WED AFTN. STRONG LARGE SCALE ASCENT...COOLING TEMPERATURES ALOFT AND INCREASING FRONTAL FORCING SHOULD BE FAVORABLE FOR TSTM INITIATION FROM SERN LWR MI ACROSS IND...SRN IL...SERN MO AND NRN AR NEAR/AFTER PEAK HEATING. VERTICAL SHEAR WILL BE MORE THAN SUFFICIENT FOR ORGANIZED STORMS...PROBABLY IN THE FORM OF LINE SEGMENTS. SUPERCELLS WILL BE POSSIBLE...PRIMARILY ACROSS THE LWR OH VLY WHERE MORE INSTABILITY WILL BE AVAILABLE FOR SUSTAINED UPDRAFTS. OTHERWISE...GIVEN THE INCREASING UNIDIRECTIONALITY TO THE WIND FIELDS WITH TIME...ANY LINE SEGMENT COULD CONTAIN BOWS/LEWPS. DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY THREATS. SOME SEVERE THREAT WILL LIKELY CONTINUE INTO THE EVE HOURS EWD INTO PARTS OF OH...NWRN/WRN KY AND NWRN TN. ...MID/LWR MO VLY... A SECONDARY REGION OF POSSIBLE SEVERE TSTMS WILL EVOLVE WED AFTN FROM PARTS OF ERN NEB SEWD INTO NWRN MO. CORE OF STRONGEST DCVA ASSOCD WITH THE STRONGER IMPULSE WILL TRACK SEWD ACROSS THIS REGION BETWEEN 18-00Z. LAPSE RATES WILL STRONGLY STEEPEN AS H5 TEMPERATURES AOB MINUS 20 DEG C SURGE SEWD ATOP RESIDUAL 50S DEW POINTS. IF BOUNDARY LAYER CAN HEAT...A BAND OF LOW-TOPPED AND FAST-MOVING TSTMS WILL DEVELOP GIVING POSSIBLE DAMAGING WINDS/HAIL. LOW-PROBABILITIES OF SEVERE WILL BE INTRODUCED...BUT IF THERMODYNAMICS APPEAR TO BE MORE FAVORABLE...A HIGHER RISK COULD BE ADDED IN LATER FCSTS. ..RACY.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 12:51:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 08:51:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271250 SWODY1 SPC AC 271249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT WED SEP 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDWEST...LWR OH VLY AND OZARKS... ...SYNOPSIS... HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WILL PREVAIL ACROSS NOAM THIS PERIOD. LEAD IMPULSE NOW CROSSING WI SHOULD CONTINUE E ACROSS MI AND SW ONTARIO AS STRONGER UPSTREAM DISTURBANCE NOW OVER ND DRIVES SEWD INTO SRN MO/IL BY 12Z THURSDAY. COLD FRONT NOW EXTENDING FROM THE UPR GRT LKS INTO KS WILL BE STRONGLY REINFORCED LATER TODAY/TONIGHT AS ND IMPULSE SWEEPS SEWD. THE FRONT SHOULD OVERTAKE LEAD WINDSHIFT/LEE TROUGH OVER THE OZARKS/SRN PLNS LATE THIS AFTERNOON...AND REACH THE LWR GRTLKS...LWR TN VLY AND CNTRL TX BY THURSDAY MORNING. ...MIDWEST SW INTO THE LWR OH VLY/OZARKS... A BAND OF SHOWERS/STORMS SHOULD CONTINUE TO PRECEDE LEAD IMPULSE CROSSING LWR MI...NRN IL AND NRN IND TODAY. MODERATE UNIDIRECTIONAL WLY FLOW AND MODEST INSTABILITY SUGGEST THAT THIS ACTIVITY SHOULD REMAIN MOSTLY SUB-SEVERE...BUT GUSTY WINDS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. A BIT LATER...MORE VIGOROUS STORMS EXPECTED TO FORM FROM MID TO LATE AFTN THROUGH TONIGHT ALONG STRENGTHENING COLD FRONT FROM SE LWR MI...NW OH...CNTRL/ERN IND AND ERN/SRN IL SW INTO THE OZARKS. MOISTURE WILL BE LIMITED BY LATE SEPTEMBER STANDARDS...WITH AVERAGE SURFACE DEWPOINTS LIKELY TO REMAIN IN THE LOW-MID 50S. BUT LOW TO MID LEVEL LAPSE RATES SHOULD STEEPEN GIVEN MODERATE TO STRONG SURFACE HEATING AND DIFFERENTIAL THERMAL ADVECTION. MLCAPE MAY REACH 500 J/KG IN NRN IND/NRN OH...AND 1500 J/KG IN THE LWR OH VLY/OZARKS. LARGELY UNIDIRECTIONAL W OR WSWLY FLOW WILL PREVAIL ACROSS THE SLIGHT RISK REGION...WITH 500 MB SPEEDS AROUND 40 KTS. THIS SETUP SHOULD SUPPORT ORGANIZED LINE SEGMENTS/CLUSTERS OF STORMS... INCLUDING POSSIBLE SUPERCELLS. BOWING SEGMENTS AND SUSTAINED UPDRAFTS MAY YIELD HIGH WIND AND HAIL...ESPECIALLY FROM THE LWR OH VLY INTO SRN MO/NRN AR...WHERE INSTABILITY/SHEAR COMBINATION SHOULD BE GREATEST. A LIMITED SEVERE THREAT MAY CONTINUE INTO LATE EVENING OVER NRN/CNTRL AR...W TN AND WRN/CNTRL KY AS FORCING FOR ASCENT INTENSIFIES IMMEDIATELY DOWNSTREAM FROM AMPLIFYING UPR TROUGH. ...MID/LWR MO VLY... AREA OF STRONG UVV ASSOCIATED WITH ND IMPULSE HAS SUPPORTED OVERNIGHT SHOWERS/TSTMS OVER ERN MT AND THE WRN DAKS. AS THIS UVV MAX CONTINUES SEWD...A SECONDARY REGION OF POSSIBLE SEVERE CONVECTION MAY EVOLVE WITH SURFACE HEATING OVER SE SD AND NRN/ERN NEB SE INTO WRN IA/NW MO. SATELLITE SUGGESTS THAT CLOUDS WILL COVER PARTS OF THE MID/LWR MO VLY THROUGH MIDDAY. BUT WITH CORE OF STRONGEST DCVA/MID LEVEL COOLING TRACKING OVER REGION FOLLOWING MAX HEATING...AND WITH DEWPOINTS REMAINING IN THE UPR 40S DESPITE LOW LEVEL CAA...SETUP MAY FOSTER DEVELOPMENT OF SCATTERED FAST-MOVING/ LOW-TOPPED TSTMS. GIVEN PROXIMITY OF 50+ KT MID LEVEL JET CORE AND COOL MID LEVEL TEMPS...THESE COULD YIELD A FEW SPOTS OF DAMAGING WIND/HAIL. ..CORFIDI/GUYER.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 12:57:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 08:57:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271257 SWODY1 SPC AC 271256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED SEP 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDWEST...LWR OH VLY AND OZARKS... ...SYNOPSIS... HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WILL PREVAIL ACROSS NOAM THIS PERIOD. LEAD IMPULSE NOW CROSSING WI SHOULD CONTINUE E ACROSS MI AND SW ONTARIO AS STRONGER UPSTREAM DISTURBANCE NOW OVER ND DRIVES SEWD INTO SRN MO/IL BY 12Z THURSDAY. COLD FRONT NOW EXTENDING FROM THE UPR GRT LKS INTO KS WILL BE STRONGLY REINFORCED LATER TODAY/TONIGHT AS ND IMPULSE SWEEPS SEWD. THE FRONT SHOULD OVERTAKE LEAD WINDSHIFT/LEE TROUGH OVER THE OZARKS/SRN PLNS LATE THIS AFTERNOON...AND REACH THE LWR GRTLKS...LWR TN VLY AND CNTRL TX BY THURSDAY MORNING. ...MIDWEST SW INTO THE LWR OH VLY/OZARKS... A BAND OF SHOWERS/STORMS SHOULD CONTINUE TO PRECEDE LEAD IMPULSE CROSSING LWR MI...NRN IL AND NRN IND TODAY. MODERATE UNIDIRECTIONAL WLY FLOW AND MODEST INSTABILITY SUGGEST THAT THIS ACTIVITY SHOULD REMAIN MOSTLY SUB-SEVERE...BUT GUSTY WINDS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. A BIT LATER...MORE VIGOROUS STORMS EXPECTED TO FORM FROM MID TO LATE AFTN THROUGH TONIGHT ALONG STRENGTHENING COLD FRONT FROM SE LWR MI...NW OH...CNTRL/ERN IND AND ERN/SRN IL SW INTO THE OZARKS. MOISTURE WILL BE LIMITED BY LATE SEPTEMBER STANDARDS...WITH AVERAGE SURFACE DEWPOINTS LIKELY TO REMAIN IN THE LOW-MID 50S. BUT LOW TO MID LEVEL LAPSE RATES SHOULD STEEPEN GIVEN MODERATE TO STRONG SURFACE HEATING AND DIFFERENTIAL THERMAL ADVECTION. MLCAPE MAY REACH 500 J/KG IN NRN IND/NRN OH...AND 1500 J/KG IN THE LWR OH VLY/OZARKS. LARGELY UNIDIRECTIONAL W OR WSWLY FLOW WILL PREVAIL ACROSS THE SLIGHT RISK REGION...WITH 500 MB SPEEDS AROUND 40 KTS. THIS SETUP SHOULD SUPPORT ORGANIZED LINE SEGMENTS/CLUSTERS OF STORMS... INCLUDING POSSIBLE SUPERCELLS. BOWING SEGMENTS AND SUSTAINED UPDRAFTS MAY YIELD HIGH WIND AND HAIL...ESPECIALLY FROM THE LWR OH VLY INTO SRN MO/NRN AR...WHERE INSTABILITY/SHEAR COMBINATION SHOULD BE GREATEST. A LIMITED SEVERE THREAT MAY CONTINUE INTO LATE EVENING OVER NRN/CNTRL AR...W TN AND WRN/CNTRL KY AS FORCING FOR ASCENT INTENSIFIES IMMEDIATELY DOWNSTREAM FROM AMPLIFYING UPR TROUGH. ...MID/LWR MO VLY... AREA OF STRONG UVV ASSOCIATED WITH ND IMPULSE HAS SUPPORTED OVERNIGHT SHOWERS/TSTMS OVER ERN MT AND THE WRN DAKS. AS THIS UVV MAX CONTINUES SEWD...A SECONDARY REGION OF POSSIBLE SEVERE CONVECTION MAY EVOLVE WITH SURFACE HEATING OVER SE SD AND NRN/ERN NEB SE INTO WRN IA/NW MO. SATELLITE SUGGESTS THAT CLOUDS WILL COVER PARTS OF THE MID/LWR MO VLY THROUGH MIDDAY. BUT WITH CORE OF STRONGEST DCVA/MID LEVEL COOLING TRACKING OVER REGION FOLLOWING MAX HEATING...AND WITH DEWPOINTS REMAINING IN THE UPR 40S DESPITE LOW LEVEL CAA...SETUP MAY FOSTER DEVELOPMENT OF SCATTERED FAST-MOVING/ LOW-TOPPED TSTMS. GIVEN PROXIMITY OF 50+ KT MID LEVEL JET CORE AND COOL MID LEVEL TEMPS...THESE COULD YIELD A FEW SPOTS OF DAMAGING WIND/HAIL. ..CORFIDI/GUYER.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 16:28:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 12:28:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271628 SWODY1 SPC AC 271627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CDT WED SEP 27 2006 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST SWWD ACROSS FROM THE LWR OH VLY TO THE OZARKS... ...SYNOPSIS... WV IMAGERY INDICATES A SERIES OF MID LEVEL IMPULSES WITHIN BROADER TROUGH OVERSPREADING THE CENTRAL U.S. THIS MORNING. ONE SYSTEM WILL CONTINUE EWD ACROSS THE CENTRAL GREAT LAKES...WHILE MORE SUBTLE SRN STREAM IMPULSE NOW SUSTAINING CONVECTION NEAR THE OZARKS IS ABSORBED INTO BROADER TROUGH AND SPREADS EWD TOWARDS THE LOWER OH RIVER VALLEY. AN EVEN STRONGER SYSTEM NOW MOVING ACROSS THE SD WILL AMPLIFY LARGER TROUGH AS IT DIGS SEWD INTO THE MID MS RIVER VALLEY OVERNIGHT. AT THE SURFACE...PRIMARY/LEADING COLD FRONT ASSOCIATED WITH THE BROAD MID/UPPER TROUGH EXTENDED FROM A LOW CENTER OVER NRN LOWER MI SSWWD INTO SWRN MO/NERN OK AT 15Z. THIS WILL CONTINUE ADVANCING ESEWD THROUGH THE DAY...AHEAD OF WHICH A GRADUAL INCREASE IN SURFACE DEW POINTS WILL OCCUR WITH READINGS IN THE MID 50S-LOW 60S EXPECTED FROM SERN MO/NRN AR INTO CENTRAL IND BY LATE IN THE DAY. ...OZARKS INTO THE SRN GREAT LAKES... MODELS VERY CONSISTENT IN INCREASING INSTABILITY AND THE POTENTIAL FOR DEEP MOIST CONVECTION ALONG AND JUST AHEAD OF THE SURFACE FRONT FROM NWRN AR INTO SRN IL AROUND 21Z...WITH PRIMARY QPF BETWEEN 21Z-00Z. FORECAST SOUNDINGS FROM THE NAM AND RUC INDICATE MLCAPE MAY APPROACH 2000 J/KG SHOULD SURFACE DEW POINTS REACH THE LOW 60S F NEAR PEAK HEATING INTO THE LOWER OH RIVER VALLEY. WILL MOST LIKELY SEE AN AXIS OF 1000-1500 J/KG MLCAPE EXTENDING FROM SWRN MO INTO SWRN/CENTRAL IND BY 21Z...WITH A HIGHER MAX POSSIBLE NEAR THE LOWER OH RIVER VALLEY. MLCAPE NEARER 500 J/KG CAN BE EXPECTED INTO THE NERN IND/NWRN OH. MODEST TO STRONG WNWLY FLOW ALOFT WILL ALSO SUPPORT EFFECTIVE SHEAR AROUND 40 KT...SUGGESTING A FEW SUPERCELLS WILL BE POSSIBLE ALONG WITH AT LEAST A THREAT OF A TORNADO OR TWO. HOWEVER...OVERALL EVOLUTION INTO ONE OR MORE SMALL LINES/CLUSTERS IS THE MORE LIKELY SCENARIO UNDER A NEAR-UNIFORM WLY FLOW THROUGH THE MID LEVELS. LARGE HAIL AND DAMAGING WINDS WILL LIKELY BE PRIMARY SEVERE THREATS. OVERALL SEVERE THREAT IS EXPECTED TO BECOME MORE LIMITED WITH NEWD EXTENT TOWARDS THE SRN GREAT LAKES. ...CENTRAL PLAINS... A SECONDARY REGION OF POSSIBLE SEVERE TSTMS WILL EVOLVE THIS AFTERNOON FROM PARTS OF SERN SD/NEB SEWD INTO NWRN MO/WRN IA. CORE OF STRONGEST DCVA ASSOCD WITH APPROACHING IMPULSE WILL TRACK SEWD ACROSS THIS REGION BETWEEN 18-00Z. LAPSE RATES WILL STRONGLY STEEPEN AS H5 TEMPERATURES AOB MINUS 20 DEG C SURGE SEWD ATOP RESIDUAL 50S DEW POINTS. IF BOUNDARY LAYER CAN HEAT...A BAND OF LOW-TOPPED AND FAST-MOVING TSTMS WILL DEVELOP PRODUCING POSSIBLE HAIL/STRONG WINDS. ..EVANS/CROSBIE.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 19:42:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 15:42:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271943 SWODY1 SPC AC 271941 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT WED SEP 27 2006 VALID 272000Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM IND TO AR... FRONTAL FORCING APPEARS TO BE AIDING RECENT THUNDERSTORM DEVELOPMENT ACROSS WCNTRL IND...INITIALLY OVER MONTGOMERY AND PARK COUNTIES. BOUNDARY LAYER AIRMASS IS NOT TERRIBLY UNSTABLE...ROUGHLY 500-1000 J/KG MLCAPE...BUT LARGE SCALE SUPPORT IS CERTAINLY FOCUSED ACROSS THIS PORTION OF THE FRONTAL ZONE. LATEST THINKING IS THUNDERSTORMS WILL CONTINUE TO EVOLVE WITHIN BROADER ZONE OF DEEPENING SHOWERS ACROSS THE REMAINDER OF CNTRL/NERN IND. HAIL SHOULD ACCOMPANY THE STRONGER ECHOES...WHILE GUSTY WINDS MAY ALSO BE NOTED. A SOMEWHAT DIFFERENT CONVECTIVE MODE IS EVOLVING ACROSS AR INTO SERN MO THIS AFTERNOON. WV IMAGERY INDICATES GOOD CONTINUITY WITH WEAK UPPER IMPULSE THAT HAS SHEARED EWD ACROSS NM/OK INTO WCNTRL AR. THIS FEATURE HAS A HISTORY OF MID LEVEL CONVECTION WITH ISOLATED THUNDERSTORMS. OVER THE LAST HOUR OR SO BOUNDARY LAYER HAS APPARENTLY WEAKENED INHIBITION SUFFICIENTLY FOR RENEWED ROBUST NEAR-SFC BASED THUNDERSTORMS NORTH OF I-40 FROM CRAWFORD TO NEWTON COUNTIES IN AR...JUST NE OF FSM. AREAL COVERAGE SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HOURS WITH ENEWD DEVELOPMENT EXPECTED ACROSS THE REMAINDER OF NRN AR INTO SERN MO...EVENTUALLY SPREADING DOWNSTREAM INTO WRN KY/TN. LARGE HAIL AND PERHAPS SOME GUSTY WINDS SHOULD OCCUR WITH STRONGER STORMS. LATER THIS EVENING...COLD FRONT SHOULD CATCH UP WITH THIS ACTIVITY FORCING SQUALL LINE DEVELOPMENT DOWNSTREAM INTO PORTIONS OF CNTRL KY/MIDDLE TN. THIS LATE NIGHT ACTIVITY SHOULD GRADUALLY DECREASE IN INTENSITY AS BOUNDARY LAYER COOLS AND INSTABILITY WEAKENS. ..DARROW.. 09/27/2006  From swody1 at goshenarc.org Thu Sep 28 00:57:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 20:57:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280057 SWODY1 SPC AC 280055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT WED SEP 27 2006 VALID 280100Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL AR TO N-CENTRAL KY... ...SYNOPSIS... DEEP SYNOPTIC TROUGH WILL CONTINUE TO DOMINATE MOST OF CONUS FROM ERN PLAINS TO ATLANTIC COAST...WITH RIDGE ACROSS GREAT BASIN REGION. MOISTURE CHANNEL IMAGERY AND AVAILABLE UPPER AIR DATA INDICATE EJECTING SHORTWAVE TROUGH INVOF QUE/ONT BORDER...TO BE REPLACED BY UPSTREAM SHORTWAVE NOW DIGGING SEWD ACROSS IA. WEAK UPPER LEVEL PERTURBATION THAT CROSSED SRN PLAINS OVERNIGHT NOW IS BARELY EVIDENT ACROSS AR...AND SHOULD CONTINUE TO WEAKEN AHEAD OF PROGRESSIVE IA TROUGH. AT SFC...COLD FRONT WAS ANALYZED AT 00Z FROM SERN LOWER MI SWWD ACROSS CENTRAL INDIANA...OZARKS OF SRN MO/NRN AR...S-CENTRAL OK AND NW TX. PREFRONTAL SFC TROUGH AND WIND SHIFT WAS EVIDENT FROM W-CENTRAL TX ACROSS SERN OK AND CENTRAL AR...NORTHEASTWARD INTO ONGOING CONVECTION OVER AR. PREFRONTAL TROUGH THEN WAS COLLOCATED WITH BROKEN BAND OF TSTMS NEAR A LINE FROM ARG...PAH...OWB...30 NNW CVG...20 NNW CLE. BOTH TROUGH AND FRONT ARE FCST TO MOVE EWD ACROSS OH...KY...MUCH OF WRN-MID TN..ARKLATEX REGION AND W-CENTRAL TX THROUGH REMAINDER PERIOD. ...AR TO OH VALLEY... BEST-ORGANIZED POTENTIAL FOR SVR WIND AND HAIL WILL BE IN AND NEAR WW 801 FOR ANOTHER 2-3 HOURS...WHERE EFFECTIVE BULK SHEAR...CONVERGENCE...MOISTURE AND BUOYANCY ARE MAXIMIZED REGIONALLY ATTM. REF WW 801 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST INFO. AFTER SUNSET...SBCINH IS FCST TO INCREASE GRADUALLY AS MRGLLY MOIST SFC AIR MASS DIABATICALLY COOLS...REDUCING POTENTIAL FOR SVR GUSTS TO REACH SFC. THIS ALSO WILL DIMINISH SBCAPE TO NEAR ZERO...WITH ANY NOCTURNAL TSTMS SUPPORTED BY NARROW PLUME OF ELEVATED WAA AND WEAK MOISTURE TRANSPORT. THEREFORE...SVR PROBABILITIES WILL BECOME SMALLER WITH TIME AND WITH EWD EXTENT AS PRIMARY CONVECTIVE BAND MOVES EWD. ..EDWARDS.. 09/28/2006  From swody1 at goshenarc.org Fri Sep 1 00:54:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 20:54:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010055 SWODY1 SPC AC 010053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT THU AUG 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS WITH ERNESTO... ...CENTRAL PLAINS... LINEAR MCS HAS EVOLVED OVER ERN CO...EXTENDING FROM MORGAN COUNTY TO LINCOLN COUNTY. THIS ACTIVITY IS SPREADING EWD AT ROUGHLY 25 KT...WITH SRN EXTENT MORE SUPERCELLULAR IN NATURE. IT APPEARS A WEAK MVC IS EVOLVING OVER NERN CO WHERE LARGER PRECIPITATION SHIELD CONTINUES TO EXPAND...ALONG WITH COLD POOL. DOWNSTREAM...00Z SOUNDING FROM DDC DEPICTS SIGNIFICANT LOW LEVEL WARM ADVECTION THROUGH 700MB...WITH SUBSTANTIAL VEERING WITH HEIGHT AND MODERATE INSTABILITY. ISOLATED THUNDERSTORMS HAVE RECENTLY DEVELOPED AHEAD OF MAIN MCS OVER PORTIONS OF WRN KS. ONE STORM OVER WICHITA COUNTY IS ORGANIZING ALONG A WELL DEFINED LOW LEVEL CONFLUENCE ZONE THAT STRETCHES FROM NWRN OK INTO ECNTRL CO. LATEST THINKING IS ISOLATED STORMS WILL CONTINUE TO EVOLVE WITHIN THIS FAVORED ZONE OF LOW LEVEL WARM ADVECTION...WELL AHEAD OF MCS. WITH TIME...SEWD MOVEMENT OF MCS WILL MERGE WITH THIS DOWNSTREAM CONVECTION BEFORE PROPAGATING INTO PORTIONS OF NWRN OK LATE TONIGHT. LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE WITH THESE CONVECTIVE CLUSTERS WELL INTO THE MORNING HOURS. ...ERNESTO... ERNESTO...LOCATED JUST SOUTH OF ILM...CONTINUES ITS NWD MOVEMENT TO TOWARD THE SRN NC COAST. WIDESPREAD PRECIPITATION HAS SPREAD WELL INLAND ACROSS MUCH OF NC WITH STRONGER UPDRAFTS LOCATED INVOF CIRCULATION CENTER. LOW LEVEL SHEAR PROFILES WILL INCREASE AS LOW MOVES INLAND OVER THE NEXT FEW HOURS. ALTHOUGH LIGHTNING REMAINS CONCENTRATED OVER THE GULF STREAM...ISOLATED BRIEF TORNADOES MAY YET DEVELOP WITHIN STRONGER CONVECTIVE BANDS. ..DARROW.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 05:59:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 01:59:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010559 SWODY1 SPC AC 010558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI SEP 01 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FOR ERNESTO ACROSS ERN NC AND SERN VA... ...CENTRAL PLAINS... CONVECTION WILL READILY DEVELOP AGAIN ACROSS THE CENTRAL HIGH PLAINS THIS AFTERNOON AHEAD OF MAIN FRONTAL SURGE. LATE EVENING MODEL GUIDANCE AND EARLY MORNING DIAGNOSTIC DATA SUGGEST SFC PRESSURES WILL CONTINUE TO RISE ACROSS THE NRN ROCKIES FORCING COLD FRONT INTO NERN CO BY 18Z. LATEST THINKING IS BOUNDARY LAYER LAPSE RATES WILL STEEPEN SUFFICIENTLY...GIVEN STRENGTHENING NELY UPSLOPE REGIME...FOR THUNDERSTORM DEVELOPMENT BY 20Z FROM THE WY/CO BORDER INTO SWRN NEB. THIS ACTIVITY SHOULD SPREAD SEWD WITHIN MODERATELY-STRONG SHEARED ENVIRONMENT...SFC-6KM BULK SHEAR ON THE ORDER OF 40KT. ALTHOUGH SUPERCELL STRUCTURES ARE POSSIBLE...IT APPEARS FORCING MAY FACILITATE STORM MERGERS AND POSSIBLE MCS EVOLUTION BY LATE AFTERNOON ACROSS ERN CO. THIS ACTIVITY SHOULD SPREAD SEWD ACROSS WRN KS INTO THE OK/TX PANHANDLES LATER IN THE EVENING. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY SEVERE THREATS. ...ERN NC/SERN VA... TROPICAL STORM ERNESTO WILL LIFT NWD ACROSS NC INTO SRN VA AND WEAKEN LATER THIS MORNING. BOUNDARY LAYER AIRMASS IS QUITE STABLE OVER VA THIS MORNING WHERE SFC DEW POINTS CONTINUE TO DROP WITH SUSTAINED NELY LOW LEVEL TRAJECTORIES FROM DOMINANT SFC RIDGE OVER SERN CANADA. TROPICAL WEDGE OVER ERN NC INTO SERN VA SHOULD PROVIDE SUFFICIENT INSTABILITY FOR CONVECTION AND THE THREAT FOR ISOLATED TORNADOES THIS MORNING. HOWEVER...STRONGER SHEAR WILL SPREAD ATOP STABLE BOUNDARY LAYER OVER THE MIDDLE ATLANTIC AND THE SEVERE THREAT WILL DECREASE THIS AFTERNOON. ..DARROW/BOTHWELL.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 12:33:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 08:33:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011232 SWODY1 SPC AC 011230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0730 AM CDT FRI SEP 01 2006 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS IN EXTREME NERN NC AND SERN VA... ...SYNOPSIS... T.S. ERNESTO IS FORECAST TO SHIFT NWD THROUGH THE PERIOD FROM NC INTO VA AND WEAKEN...THOUGH SYSTEM WILL RESULT IN STRONG ISENTROPIC LIFTING AND WIDESPREAD HEAVY RAINFALL ACROSS THE MID ATLANTIC STATES THROUGH TONIGHT. AN UPPER TROUGH IN THE NRN ROCKIES WILL SHIFT ESEWD INTO THE NRN/CENTRAL PLAINS LATER TODAY...PUSHING A COLD FRONT SEWD INTO THE CENTRAL PLAINS/ROCKIES THIS AFTERNOON. ...NERN NC/EXTREME SERN VA... THE CENTER OF THE ERNESTO APPEARED TO BE LOCATED NEAR RWI WITH A WARM FRONT EXTENDING NEWD FROM THIS SYSTEM TO NEAR THE VA/NC BORDER. WHILE MID 70 DEWPOINTS ARE PRESENT EAST OF THIS BOUNDARY ...INSTABILITY IS QUITE WEAK DUE TO THE MOIST ADIABATIC LAPSE RATES. VAD WIND PROFILES SHOW THE SHEAR REMAINS STRONG...ESPECIALLY IN THE LOWER LEVELS WITH THE 1 KM SHEAR RANGING FROM 30-50 KT. THE MAIN BAND OF CONVECTION CURRENTLY EXTENDS FROM THE OUTER BANKS TO THE EXTREME SERN VA COAST. THE STRONG LOW/DEEP LAYER SHEAR WILL SUPPORT SUPERCELLS AND THE POTENTIAL FOR TORNADOES THROUGH THE MORNING HOURS...REFERENCE WW 762. AS ERNESTO WEAKENS AND MOVES NWD INTO VA AND ENCOUNTERS AN INCREASINGLY COOLER AND MORE STABLE BOUNDARY LAYER...THE TORNADO THREAT SHOULD DIMINISH BY EARLY AFTERNOON. ...CENTRAL PLAINS... SKIES HAVE CLEARED ACROSS NERN CO AS EARLIER CONVECTIVE COMPLEX HAD MOVED EWD INTO KS...WITH ONLY A FEW REMAINING STORMS. BOUNDARY LAYER IS RELATIVELY MOIST AND STORMS ARE ONCE AGAIN EXPECTED TO DEVELOP NEAR THE HIGHER TERRAIN THIS AFTERNOON AS THE COLD FRONT SURGES SWD. THOUGH ONLY 10-15 KT WINDS ARE FORECAST AHEAD OF THE FRONT FROM THE SURFACE TO 600 MB...STRONGLY VEERING WINDS IN THE 3 KM AND 30-50 KT WINDS FROM 600-250MB SHOULD SUPPORT DEEP LAYER SHEAR NEAR 40 KT. ALTHOUGH SUPERCELL STRUCTURES ARE POSSIBLE...THE FRONTAL FORCING AND WEAK LOW LEVEL WINDS ARE EXPECTED TO RESULT IN MERGING STORM OUTFLOWS. THIS MAY AID IN THE EVOLUTION OF AN MCS IN ERN CO BY LATE AFTERNOON. THIS SYSTEM SHOULD THEN SPREAD SEWD... ALONG WITH THE FRONT AND INTO THE INSTABILITY AXIS...ACROSS WRN KS INTO THE OK/TX PANHANDLES THIS EVENING...WITH A FEW HAIL AND DAMAGING WIND EVENTS. ..IMY.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 16:14:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 12:14:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011613 SWODY1 SPC AC 011612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT FRI SEP 01 2006 VALID 011630Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL HIGH PLAINS REGION... ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY SHOWS UPPER TROUGH MOVING ACROSS MT/WY DIGGING ESEWD IN RESPONSE TO UPSTREAM AMPLIFICATION OF RIDGE AXIS FROM OFF THE PACIFIC NW COAST INTO NRN BRITISH COLUMBIA. THIS TROUGH IS FORECAST TO MOVE INTO THE NRN HIGH PLAINS TONIGHT AND CLOSE OFF INTO AN UPPER LOW. ASSOCIATED COLD FRONT FROM MN SWWD INTO NWRN CO WILL MOVE SEWD ACROSS THE CENTRAL PLAINS AND PROVIDE THE PRIMARY FOCUS FOR CONVECTIVE DEVELOPMENT LATER THIS AFTERNOON INTO TONIGHT. SURFACE DEW POINTS ARE CURRENTLY IN THE MID/UPPER 50S ACROSS ERN CO/WRN KS REGION AND LITTLE CHANGE IN MOISTURE CONTENT IS EXPECTED IN ADVANCE OF THE APPROACHING COLD FRONT. VISIBLE SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS MUCH OF NORTH CENTRAL/NERN CO WHICH WILL PERMIT STRONGER DIABATIC HEATING TO OCCUR THIS AFTERNOON...CONTRIBUTING TO DESTABILIZATION WITH MLCAPE OF 1000-1500 J/KG LIKELY BY MID AFTERNOON. THESE FACTORS SUPPORT 12Z RUC/NAM AND 09Z SREF NAMKF CONTROL RUN FORECASTS OF CONVECTIVE INITIATION ALONG THE NORTH CENTRAL/NERN CO BORDER AREA BY MID/LATE AFTERNOON...AS FRONTAL CONVERGENCE AND LOW LEVEL UPSLOPE WINDS ENHANCE ASCENT OF MOIST/UNSTABLE AIR MASS. VERTICAL WIND PROFILES ARE EXPECTED TO EXHIBIT STRONG VEERING/DIRECTIONAL SHEAR WITH HEIGHT...WHICH WILL COMPENSATE FOR RELATIVELY MODEST WESTERLY WIND SPEEDS IN THE MID LEVELS /20-25 KT AT 500 MB/. RESULTANT 30-40 KT DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ISOLATED SUPERCELLS DURING THE LATE AFTERNOON AND EARLY EVENING. CONVECTION IS EXPECTED TO INCREASE IN COVERAGE AND CONSOLIDATE INTO ONE OR TWO MCS/S BY LATE EVENING...WITH ACTIVITY SPREADING SEWD INTO PARTS OF WRN KS AND POSSIBLY AS FAR SOUTH AS THE OK/NRN TX PANHANDLE REGION DURING THE OVERNIGHT HOURS. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH STRONGER STORMS. ...SERN VA... REMNANTS OF ERNESTO ARE CONTINUING TO MOVE NWD INTO SERN VA...WITH WIDESPREAD RAIN ACROSS VA AND THE DELMARVA REGION. THERMODYNAMIC PROFILES SUGGEST VERY LIMITED INSTABILITY AND THIS IS SUPPORTED BY THE LACK OF CG LIGHTNING STRIKES OVER LAND DURING THE LAST 6 HOURS. THE EXTENSIVE REGION OF CLOUDS/PRECIPITATION IN ADVANCE OF THE CIRCULATION CENTER SUGGEST THERE WILL BE FEW IF ANY OPPORTUNITIES FOR THE DEVELOPMENT OF LOCALIZED ZONES OF HEATING/DESTABILIZATION TO OCCUR. THUS...THE SEVERE POTENTIAL APPEARS TO HAVE DIMINISHED THIS MORNING AND THIS TREND IS EXPECTED TO CONTINUE THIS AFTERNOON AS THE CIRCULATION LIFTS NWD INTO A PROGRESSIVELY COOLER LOW LEVEL ENVIRONMENT. THE THREAT FOR AN ISOLATED BRIEF TORNADO OR STRONG CONVECTIVE WIND GUST MAY CONTINUE THIS AFTERNOON OVER SERN VA BUT OVERALL THREAT NO LONGER WARRANTS A SLIGHT RISK. ..WEISS/GUYER.. 09/01/2006  From swody1 at goshenarc.org Fri Sep 1 19:59:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 15:59:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011959 SWODY1 SPC AC 011957 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0257 PM CDT FRI SEP 01 2006 VALID 012000Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN CO AND WRN KS... ...CNTRL HIGH PLAINS/SRN PLAINS... A HIGHLY MERIDIONAL UPPER-LEVEL TROUGH EXTENDS SWD ACROSS ERN MT AND ERN WY WITH THE SRN EXTENT LOCATED ACROSS NRN CO. AT THE SFC...A COLD FRONT IS MOVING SWD ACROSS NE CO AND STRONG LOW-LEVEL CONVERGENCE IS SHOWN ALONG THE BOUNDARY ACCORDING TO OBJECTIVE ANALYSIS. CONVECTION IS BEGINNING TO DEVELOP IN THE FRONT RANGE FOOTHILLS WITH OTHER STORMS INITIATING IN THE SANGRE DE CRISTOS. SFC DEWPOINTS ALONG AND SOUTH OF I-70 ARE NEAR 60 F AND MODERATE INSTABILITY IS IN PLACE. AS A RESULT...THUNDERSTORMS SHOULD INCREASE IN COVERAGE ACROSS ECNTRL AND SERN CO LATE THIS AFTERNOON WITH MCS DEVELOPMENT POSSIBLE THIS EVENING. THE GRANADA CO PROFILER SHOWS 0-6 KM SHEAR OF 30-35 KT WHICH IS MOSTLY DUE TO DIRECTIONAL SHEAR BELOW 3 KM AND MID-LEVEL WLY FLOW ALOFT. THIS SHEAR PROFILE APPEARS REPRESENTATIVE OF THE SHEAR ENVIRONMENT ACROSS MUCH OF ERN CO AND SHOULD BE SUFFICIENT FOR ISOLATED SUPERCELLS ALTHOUGH STRONG MULTICELL STORMS WILL ALSO BE LIKELY. VERY STEEP LAPSE RATES EXIST ACROSS ERN CO AND THIS COMBINED WITH THE SHEAR AND INSTABILITY SHOULD BE FAVORABLE FOR LARGE HAIL WITH THE STRONGER CELLS. ALTHOUGH WIND DAMAGE APPEARS LESS LIKELY...STRONG WIND GUSTS MAY ALSO OCCUR ESPECIALLY WITH STORMS THAT FORM ALONG OR NEAR THE COLD FRONT. THE SEVERE THREAT SHOULD CONTINUE THROUGH MUCH OF THE EVENING AS AN MCS ORGANIZES AND MOVES INTO FAR WRN KS. ...ERN VA/SRN MD... THE CENTER OF TROPICAL DEPRESSION ERNESTO IS CURRENTLY LOCATED IN SE VA AND WILL CONTINUE TO MOVE NWD TONIGHT. VERY HEAVY RAINBANDS EXIST NORTH AND EAST OF THE CENTER AND A FEW THUNDERSTORMS MAY DEVELOP IN THE AREA AROUND CHESAPEAKE BAY. ALTHOUGH VERTICAL SHEAR PROFILES STILL REMAIN SUFFICIENT FOR ISOLATED ROTATING STORMS...TORNADOES APPEAR UNLIKELY DUE TO THE WEAK INSTABILITY IN PLACE. ANY MARGINAL TORNADO THREAT SHOULD GRADUALLY DECREASE OVERNIGHT AS THE DEPRESSION MOVES FURTHER INLAND. ..BROYLES.. 09/01/2006  From swody1 at goshenarc.org Sat Sep 2 00:49:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 01 Sep 2006 20:49:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020049 SWODY1 SPC AC 020047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CDT FRI SEP 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL HIGH PLAINS... ...CENTRAL HIGH PLAINS... DEEP CONVECTION IS GRADUALLY EXPANDING ACROSS ERN CO IN ASSOCIATION WITH STRONG FRONTAL SURGE IN THE LEE OF THE CENTRAL ROCKIES. THIS ACTIVITY HAS EVOLVED INTO A SLOW-MOVING MCS THAT SHOULD CONTINUE TO PROPAGATE SEWD AT ROUGHLY 15-20 KT TOWARD SWRN KS/OK PANHANDLE. 00Z SOUNDINGS FROM BOTH DDC AND AMA ARE SUPPORTIVE OF MAINTAINING MCS-TYPE THUNDERSTORM CLUSTERS WITH MODEST DEEP LAYER SHEAR AND SBCAPE ON THE ORDER OF 1500-2000 J/KG. ALTHOUGH LOW LEVEL INFLOW IS NOT PARTICULARLY STRONG INTO THIS ACTIVITY...UNSTABLE THERMODYNAMIC PROFILES AND FRONTAL CONVERGENCE FAVOR LONG-LIVED MULTI-CELL UPDRAFTS...AND PERHAPS AN ISOLATED SUPERCELL. HAIL AND STRONG WINDS SHOULD ACCOMPANY THESE STORMS AS THEY SPREAD SEWD. ..DARROW.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 05:22:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 01:22:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020523 SWODY1 SPC AC 020521 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 AM CDT SAT SEP 02 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE PATTERN WILL BECOME INCREASINGLY HOSTILE FOR SEVERE DEEP CONVECTION OVER THE NEXT FEW DAYS AS LOW LEVEL CONVERGENCE ALONG ADVANCING SFC FRONT SPREADS WELL SOUTH OF ANY MEANINGFUL MID-HIGH LEVEL FLOW ACROSS THE PLAINS. GREATEST POTENTIAL FOR STRONG...POSSIBLY ORGANIZED STORMS WILL BE LIMITED TO STEEP LAPSE RATE REGIONS OF THE SWRN U.S...AND PERHAPS WITHIN A NARROW ZONE OF MODEST SHEAR...AHEAD OF UPPER LOW...FROM SWRN MN INTO NRN IA. ...ERN DAKOTAS/SWRN MN/NRN IA... EARLY MORNING WV IMAGERY STRONGLY SUPPORTS 00Z MODEL GUIDANCE IN SEWD MOVEMENT OF UPPER LOW ACROSS WRN DAKOTAS TOWARD NERN NEB. THIS FEATURE WILL MAINTAIN A ZONE OF WEAK LOW LEVEL CONVERGENCE FROM ERN SD INTO NRN IA AS SFC RIDGE BUILDS MAINLY SWD ACROSS THE NRN/CNTRL HIGH PLAINS. PRECIPITABLE WATER VALUES SHOULD HOLD IN EXCESS OF 1 INCH ALONG THIS AXIS...WITH SFC DEW POINTS IN THE MID-UPPER 50S. MODERATE BOUNDARY LAYER HEATING SHOULD PROVE INSTRUMENTAL IN AIDING CONVECTIVE DEVELOPMENT BY EARLY AFTERNOON. ALTHOUGH INSTABILITY WILL BE SOMEWHAT WEAK...LESS THAN 1000 J/KG...MARGINALLY SEVERE HAIL COULD OCCUR WITH STRONGER...MAINLY DIURNAL...THUNDERSTORMS. ...SWRN LOWER DESERTS OF AZ/SRN NM... AIRMASS HAS YET TO DRY SIGNIFICANTLY ALONG THE U.S./MEXICAN BORDER REGION FROM AZ INTO SRN NM...PER ANOTHER ACTIVE CONVECTIVE DAY FRIDAY...AND ONGOING THUNDERSTORM CLUSTERS JUST SOUTH OF THE BORDER OVER NRN MEXICO. CONVECTION SHOULD READILY DEVELOP AGAIN BY MID-LATE AFTERNOON ACROSS THIS REGION...WITH SWD PROPAGATION EXPECTED AS UPDRAFTS MATURE. STEEP LAPSE RATE ENVIRONMENT SHOULD SUPPORT AT LEAST GUSTY WINDS WITH STRONGER RAIN CORES. ..DARROW/GRAMS.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 12:36:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 08:36:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021236 SWODY1 SPC AC 021234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT SAT SEP 02 2006 VALID 021300Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A WEAK...BUT BROAD...TROUGH EXTENDED FROM THE NRN/CENTRAL PLAINS EWD INTO THE OH VALLEY. WITHIN THIS TROUGH...A CLOSED LOW WAS LOCATED OVER SD THIS MORNING AND IS FORECAST TO DRIFT SLOWLY SEWD INTO FAR NERN NEB BY SUNDAY MORNING. AT THE SURFACE...LOW PRESSURE ASSOCIATED WITH THE REMNANTS OF ERNESTO WAS LOCATED IN THE DELMARVA REGION. A WEAK TROUGH/FRONT EXTENDED FROM THIS LOW SWD OFF THE EAST COAST...AND THEN CROSSED THE NRN FL PENINSULA SWWD INTO THE NRN GULF. A REINFORCING COLD FRONT STRETCHED FROM WRN IA SWWD INTO THE TX PANHANDLE/NERN NM AND IS FORECAST TO PUSH THROUGH KS/OK AND INTO THE MAIN BODY OF NRN TX TONIGHT. ALTHOUGH PRECIPITATION IS EXPECTED THROUGH THE DAY AHEAD/ALONG THE FRONT...WEAK CONVERGENCE AND INSTABILITY WILL LIMIT A SEVERE THREAT WITH THE FRONTAL SYSTEM. ...SWRN MN/WRN IA... MOSTLY CLOUDY SKIES ARE LIKELY TO REDUCE HEATING AND INSTABILITY THROUGH THE DAY. HOWEVER...500 MB TEMPERATURES ARE FORECAST TO COOL SEVERAL DEGREES AND RANGE FROM -14C TO -16C BY LATE AFTERNOON... RESULTING IN MUCAPE VALUES AOB 500 J/KG. SHOWERS CURRENTLY IN THE AREA ARE EXPECTED TO WEAKEN AND PUSH EWD AS DRY SLOT IN ERN SD SPREADS EWD. STRONG DIFFLUENT FLOW ALOFT AT 250-300 MB ALONG WITH STRENGTHENING HIGH LEVEL DIVERGENCE SHOULD PROVIDE SUFFICIENT LIFT FOR A FEW THUNDERSTORMS THIS AFTERNOON. ALTHOUGH 35-40 KT DEEP LAYER SHEAR WOULD AID IN STORM ORGANIZATION...WEAK INSTABILITY IS EXPECTED TO LIMIT THE SEVERE WEATHER THREAT. THEREFORE...ONLY A 5% PROBABILITY FOR HAIL/WIND IS CURRENTLY FORECAST. ...SRN AZ... WV IMAGERY SHOWS THAT A HIGH LEVEL SHORTWAVE TROUGH WAS MOVING EWD THROUGH CENTRAL AZ WITH HIGH LEVEL DRYING BEHIND IT. THE CURRENT EWD MOTION AT 15 KT SHOULD TAKE THIS SYSTEM EAST OF THE STATE BY EARLY AFTERNOON. HOWEVER...AS HURRICANE JOHN MOVES NWWD ALONG THE SRN BAJA PENINSULA...MID/HIGH LEVEL MOISTURE IS BEING ADVECTED NWWD FROM MEXICO TOWARD SRN AZ. AS TEMPERATURES WARM TO AOA 100 DEGREES AND MIX TO MOISTURE BETWEEN 600 AND 700 MB...SCATTERED HIGH BASED CONVECTION SHOULD DEVELOP. MUCAPES AROUND 1000 J/KG AND DRY ADIABATIC LAPSES RATES IN THE LOWER 2-3 KM WOULD BE FAVORABLE FOR AT LEAST GUSTY WINDS NEAR THE STRONGER CORES. ..IMY/GRAMS.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 16:25:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 12:25:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021625 SWODY1 SPC AC 021624 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CDT SAT SEP 02 2006 VALID 021630Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SRN AZ... LATEST WATER VAPOR IMAGERY SHOWS HURRICANE JOHN ACROSS THE SRN PART OF BAJA CA WITH A PLUME OF MOISTURE EXTENDING NWD ACROSS NWRN MEXICO INTO SE AZ. MID-LEVEL MOISTURE SHOULD GRADUALLY INCREASE ACROSS SCNTRL AZ AS HURRICANE JOHN CONTINUES TO MOVE NWWD TODAY. SFC ANALYSIS SHOWS DEWPOINTS ACROSS THE SRN HALF OF AZ IN THE 55 TO 65 F RANGE WITH MODERATE INSTABILITY ALREADY IN PLACE SOUTH OF I-10 IN SW AZ. DESTABILIZATION WILL CONTINUE THIS AFTERNOON WITH SCATTERED THUNDERSTORMS DEVELOPING ALONG THE MOGOLLON RIM. FORECAST SOUNDINGS LATE THIS AFTERNOON ACROSS SCNTRL AZ SHOW DEEP ELY FLOW BELOW 700 MB WITH 0-6 KM SHEAR VALUES AROUND 20 KT. THIS COMBINED WITH LOW-LEVEL LAPSE RATES EXCEEDING 9.0 C/KM MAY BE FAVORABLE FOR STRONG WIND GUSTS WITH A FEW OF THE STRONGER MULTICELL STORMS THROUGH EARLY EVENING. ...MN/IA... A CLOSED-OFF UPPER-LEVEL LOW OVER THE NRN PLAINS WILL CONTINUE TO MOVE SLOWLY SEWD TODAY. STRONG LARGE-SCALE ASCENT ON THE EAST SIDE OF THE LOW WILL MOVE EWD INTO THE UPPER MS VALLEY SUPPORTING THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON ALONG THE LEADING EDGE OF ASCENT. LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS CNTRL IA INTO SRN MN WHERE DEWPOINTS ARE MOSTLY IN THE LOWER TO MID 60S F WITH LOCALLY HIGHER DEWPOINTS IN FAR SW AZ. DESTABILIZATION SHOULD CONTINUE ALONG THE MOIST AXIS THROUGH LATE AFTERNOON. THIS COMBINED WITH COOLING MID-LEVEL TEMPS AND INCREASING VERTICAL SHEAR ASSOCIATED WITH THE UPPER LOW MAY BE SUFFICIENT FOR A FEW STORMS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL LATE THIS AFTERNOON. ..BROYLES/GUYER.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 17:11:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 13:11:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021711 SWODY1 SPC AC 021709 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1209 PM CDT SAT SEP 02 2006 VALID 021630Z - 031200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED ...SRN AZ... LATEST WATER VAPOR IMAGERY SHOWS HURRICANE JOHN ACROSS THE SRN PART OF BAJA CA WITH A PLUME OF MOISTURE EXTENDING NWD ACROSS NWRN MEXICO INTO SE AZ. MID-LEVEL MOISTURE SHOULD GRADUALLY INCREASE ACROSS SCNTRL AZ AS HURRICANE JOHN CONTINUES TO MOVE NWWD TODAY. SFC ANALYSIS SHOWS DEWPOINTS ACROSS MUCH OF THE SRN HALF OF AZ IN THE 55 TO 65 F RANGE. LOCALLY HIGHER DEWPOINTS ARE IN FAR SW AZ WHERE MODERATE INSTABILITY IS ALREADY IN PLACE SOUTH OF I-10. DESTABILIZATION WILL CONTINUE THIS AFTERNOON WITH SCATTERED THUNDERSTORMS DEVELOPING ALONG THE MOGOLLON RIM. FORECAST SOUNDINGS LATE THIS AFTERNOON ACROSS SCNTRL AZ SHOW DEEP ELY FLOW BELOW 700 MB WITH 0-6 KM SHEAR VALUES AROUND 20 KT. THIS COMBINED WITH LOW-LEVEL LAPSE RATES EXCEEDING 9.0 C/KM MAY BE FAVORABLE FOR STRONG WIND GUSTS WITH A FEW OF THE STRONGER MULTICELL STORMS THROUGH EARLY EVENING. ...MN/IA... A CLOSED-OFF UPPER-LEVEL LOW OVER THE NRN PLAINS WILL CONTINUE TO MOVE SLOWLY SEWD TODAY. STRONG LARGE-SCALE ASCENT ON THE EAST SIDE OF THE LOW WILL MOVE EWD INTO THE UPPER MS VALLEY SUPPORTING THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON ALONG THE LEADING EDGE OF ASCENT. LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWD ACROSS CNTRL IA INTO SRN MN WHERE DEWPOINTS ARE IN THE LOWER TO MID 60S F. DESTABILIZATION SHOULD CONTINUE ALONG THE MOIST AXIS THROUGH LATE AFTERNOON. THIS COMBINED WITH COOLING MID-LEVEL TEMPS AND INCREASING VERTICAL SHEAR ASSOCIATED WITH THE UPPER LOW MAY BE SUFFICIENT FOR A FEW STORMS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL LATE THIS AFTERNOON. ..BROYLES.. 09/02/2006  From swody1 at goshenarc.org Sat Sep 2 19:54:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 15:54:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021954 SWODY1 SPC AC 021952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0252 PM CDT SAT SEP 02 2006 VALID 022000Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SRN MN/IA... CLOSED UPPER LOW...CURRENTLY CENTERED OVER SD PER SATELLITE IMAGERY...WILL MOVE SLOWLY TOWARD NERN NEB THIS FORECAST PERIOD. ASCENT ALONG THE LEADING EDGE OF THIS LARGE CIRCULATION IS EXPECTED TO MAINTAIN WEAK LOW LEVEL CONVERGENCE EXTENDING FROM NRN MO INTO SRN MN. A NARROW AXIS OF MOISTURE EXISTS ALONG THIS BOUNDARY WITH SURFACE DEWPOINTS IN THE LOWER-MID 60S. MODEST SURFACE HEATING SHOULD LIMIT DEVELOPMENT OF STRONGER INSTABILITY...WITH MLCAPE VALUES REMAINING AOB 500 J/KG FROM CENTRAL IA INTO SRN MN. THE COMBINATION OF INCREASING ASCENT...DEEP LAYER SHEAR AND STEEPENING MID LEVEL LAPSE RATES WITH THE APPROACH OF THE UPPER LOW SHOULD SUPPORT A FEW ORGANIZED STORMS. HAIL SHOULD BE THE PRIMARY THREAT WITH THE STRONGER CORES. IN ADDITION...OBJECTIVE ANALYSES INDICATED LARGE VALUES OF 0-3 KM CAPE CO-LOCATED WITH SUFFICIENT NEAR-SURFACE VERTICAL VORTICITY ALONG THE AXIS OF LOW LEVEL CONVERGENCE. THIS MAY SUPPORT A COUPLE OF LANDSPOUTS. ...AZ... VISIBLE IMAGERY/LIGHTNING DATA INDICATED THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN OF THE FOUR CORNERS REGION SWWD TO ALONG THE MOGOLLON RIM AND INTO SERN CA WHERE THE AIR MASS HAS BECOME MODERATELY UNSTABLE. NWD MOISTURE RETURN WILL CONTINUE INTO SRN AZ/SRN CA THIS FORECAST PERIOD MAINTAINING MODERATE INSTABILITY ACROSS THIS REGION AS SURFACE TEMPERATURES RISE TO 100+ BENEATH STEEP MID LEVEL LAPSE RATES. WEAK NLY MID LEVEL WINDS DEVELOPING ACROSS AZ AFTER 00Z AND POTENTIAL FOR COLD POOL DEVELOPMENT MAY ALLOW STORMS TO DEVELOP SSWWD INTO INSTABILITY AXIS...WITH ISOLATED THREAT FOR STRONG WIND GUSTS. ..PETERS.. 09/02/2006  From swody1 at goshenarc.org Sun Sep 3 00:40:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 02 Sep 2006 20:40:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030040 SWODY1 SPC AC 030038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT SAT SEP 02 2006 VALID 030100Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...AZ/SRN CA... STRONG TO POTENTIALLY SEVERE TSTMS CONTINUE TO INCREASE IN COVERAGE THIS EVENING FROM ALONG THE MOGOLLON RIM SWD THROUGH THE LOWER DESERTS OF SRN AZ AND ACROSS THE CO RIVER INTO SRN CA. THESE STORMS ARE OCCURRING WITHIN LOW-LEVEL MOISTURE SURGE OFF THE GULF OF CA WHERE OBSERVED DEWPOINTS ARE IN THE LOW TO MID 60S. WHEN COUPLED WITH TEMPERATURES IN THE 90S TO 100-105 F...AMBIENT AIR MASS REMAINS MODERATELY UNSTABLE WITH MAXIMUM MLCAPES STILL AROUND 1000-1500 J/KG OVER SWRN AZ INTO FAR SERN CA. REGIONAL VWPS INDICATE THAT TROPOSPHERIC FLOW REMAINS QUITE WEAK BELOW 9 KM AGL WITH STORM MOTIONS LARGELY GOVERNED BY PROPAGATION ALONG MERGING/ORGANIZING OUTFLOW BOUNDARIES. GIVEN THE PRESENCE OF STEEP LOW-LEVEL LAPSE RATES AND DCAPES OF 1000-1500 J/KG...LOCALLY DAMAGING WIND GUSTS WILL REMAIN THE PRIMARY SEVERE WEATHER HAZARD WITH THE MOST INTENSE CELLS THROUGH 04-05Z. ..MEAD.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 05:41:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 01:41:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030541 SWODY1 SPC AC 030540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1240 AM CDT SUN SEP 03 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER THE MID MO VALLEY... ...SYNOPSIS... COMPLEX BLOCKING PATTERN WILL CONTINUE THIS PERIOD WITH THE PRIMARY FEATURES BEING AN AMPLIFIED RIDGE FROM THE SWRN DESERTS INTO THE CANADIAN PRAIRIES AND A MID TO UPPER-LEVEL LOW WHICH WILL TRANSLATE SLOWLY SEWD THROUGH THE MIDDLE AND LOWER MO VALLEY. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO THE UPPER LOW WILL CONCURRENTLY DEVELOP SEWD FROM SERN SD ALONG THE MO VALLEY OF ERN NEB/WRN IA. ATTENDANT FRONTAL BOUNDARY /THE NRN EXTENT OF WHICH BEING OCCLUDED AND PRECEDING SURFACE LOW/ WILL GENERALLY EXTEND FROM ERN IA/WRN IL SWWD INTO SERN OK/NRN TX BY AFTERNOON. ...MID MO VALLEY... IT APPEARS DEEP...MOIST CONVECTION WILL BECOME FOCUSED IN TWO AREAS THIS AFTERNOON...1) ALONG OCCLUDED FRONTAL ZONE FROM SERN MN/WRN WI SWD INTO ERN IA AND WRN IL...AND 2) INVOF THE SURFACE AND UPPER LOWS OVER ERN NEB/WRN IA. THE GREATER POTENTIAL FOR SEVERE STORMS CAPABLE OF MAINLY SEVERE HAIL IS FORECAST TO EXIST WITH THE LATTER. 03/00Z UPPER AIR OBSERVATIONS INDICATE THAT A POCKET OF RELATIVELY COLD MID-LEVEL TEMPERATURES /I.E. -18 TO -20 C AT 500 MB/ ARE ASSOCIATED WITH THE UPPER LOW. DAYTIME HEATING COUPLED WITH THESE COLD TEMPERATURES WILL RESULT IN THE DEVELOPMENT OF STEEP LOW TO MID-LEVEL LAPSE RATES WITH AFTERNOON SBCAPES INCREASING TO AROUND 1000 J/KG. EXPECT TSTMS TO INCREASE IN COVERAGE THROUGH THE AFTERNOON ACROSS ERN NEB/WRN IA...FOCUSED LARGELY BY LOW-LEVEL CONVERGENCE INVOF ATTENDANT SURFACE LOW. WHILE STORMS SHOULD REMAIN RELATIVELY LOW-TOPPED...STRENGTHENING MID AND HIGH-LEVEL FLOW AROUND SRN PERIPHERY OF UPPER LOW MAY BE SUFFICIENT TO SUPPORT SOME UPDRAFT ROTATION WITH SEVERE HAIL BEING THE PRIMARY SEVERE THREAT. HOWEVER...SHOULD STRONG DIABATIC HEATING OCCUR NEAR SURFACE LOW...POTENTIAL WILL EXIST FOR A BRIEF TORNADO OWING TO THE CO-LOCATION OF STEEP LOW-LEVEL LAPSE RATES AND CONCENTRATED ZONE OF VORTICITY. ...LOWER CO VALLEY... LOW-LEVEL MOISTURE SURGE FROM THE GULF OF CA WILL BE MAINTAINED THROUGH THE PERIOD...SUPPORTING DEWPOINTS IN THE 60S. THIS MOISTURE IN CONJUNCTION WITH ANTICIPATED STRONG DAYTIME HEATING WILL ONCE AGAIN CONTRIBUTE TO POCKETS OF MODERATE INSTABILITY LATER TODAY WITH SBCAPES OF 1000-1500 J/KG. FORECAST SOUNDINGS SUGGEST THAT VERTICAL SHEAR WILL REMAIN RELATIVELY WEAK...HOWEVER THE STEEP LOW-LEVEL LAPSE RATES AND MODERATE INSTABILITY SHOULD BE SUPPORTIVE OF ISOLATED STRONG TO SEVERE STORMS CAPABLE OF MAINLY LOCALLY DAMAGING WIND GUSTS. ..MEAD/GRAMS.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 12:39:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 08:39:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031240 SWODY1 SPC AC 031238 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 AM CDT SUN SEP 03 2006 VALID 031300Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF EXTREME ERN NEB AND WRN IA... ...SYNOPSIS... CUTOFF LOW OVER SERN SD IS FORECAST TO MOVE SLOWLY ESEWD AND ACROSS IA LATER TODAY AND TONIGHT. A WEAK FRONT WILL ACCOMPANY THIS LOW AND SHOULD EXTEND FROM CENTRAL WI SSWWD INTO SERN OK/CENTRAL TX BY LATE AFTERNOON. HIGH PRESSURE ALOFT OVER NV AND SRN TX WILL RESULT IN A WEAK UPPER LEVEL TROUGH OVER THE LOWER CO VALLEY. ...EXTREME ERN NEB/WRN IA... LATEST RUC ANALYSIS AND MODEL FORECAST INDICATES A POCKET OF RELATIVELY COLD MID-LEVEL TEMPERATURES /-18 TO -20 C AT 500 MB/ WILL SHIFT SEWD FROM SERN SD INTO WRN IA THIS AFTERNOON. DAYTIME HEATING COUPLED WITH THE COLD TEMPERATURES ALOFT WILL RESULT IN STEEP LOW TO MID-LEVEL LAPSE RATES...WITH SBCAPES RANGING FROM 500 TO 1000 J/KG. THE INCREASING INSTABILITY AND LIFT ASSOCIATED WITH THE UPPER LOW IS EXPECTED TO AID THUNDERSTORM DEVELOPMENT ACROSS THE AREA THIS AFTERNOON. THOUGH INSTABILITY WILL BE WEAK...30-50 KT MID LEVEL WINDS ON THE SRN PERIPHERY OF THE UPPER LOW MAY SUPPORT BRIEF UPDRAFT ROTATION. GIVEN THE STEEP MID LEVEL LAPSE RATES AND COLD TEMPERATURES ALOFT...HAIL IS EXPECTED TO BE THE PRIMARY SEVERE THREAT. HOWEVER...THE POTENTIAL WILL EXIST FOR A SHORT LIVED TORNADO DUE TO THE STEEP LOW-LEVEL LAPSE RATES AND CONCENTRATED ZONE OF VORTICITY. ...WRN WI/NWRN IL AND EXTREME ERN IA... BAND OF SHOWERS/ISOLATED STORMS ARE CURRENTLY LOCATED NEAR THE FRONT ACROSS SERN MN AND ERN IA AND SHOULD PUSH SLOWLY EWD INTO WI/NWRN IL THIS AFTERNOON. IF ENOUGH SUNSHINE CAN OCCUR AND WARM TEMPERATURES INTO THE LOWER/MID 70S...THESE READINGS ALONG WITH DEWPOINTS IN THE UPPER 50S WILL YIELD 500-750 J/KG OF MLCAPE. THIS INSTABILITY COMBINED WITH LOW LEVEL CONVERGENCE LIKELY WOULD BE SUFFICIENT FOR SURFACE BASED THUNDERSTORMS TO DEVELOP JUST EAST OF THE PRE-MENTIONED CONVECTIVE BAND. A COUPLE OF NON-SUPERCELL TORNADOES DEVELOPED SATURDAY IN IA...DURING THE EARLY CONVECTIVE STAGES. A SIMILAR ENVIRONMENT WILL BE PRESENT OVER THIS AREA TODAY AND AN ISOLATED TORNADO IS POSSIBLE...THOUGH THE THREAT SHOULD BE TOO ISOLATED AND BRIEF TO WARRANT MORE THAN A 2% TORNADO PROBABILITY. ...LOWER CO VALLEY... LOW-LEVEL MOISTURE SURGE FROM THE GULF OF CA WILL BE MAINTAINED ACROSS THE REGION AS TROPICAL STORM JOHN CONTINUES MOVING NWWD ALONG THE BAJA PENINSULA. ALTHOUGH OVERNIGHT PRECIPITATION AND MORNING CLOUDS ARE EXPECTED TO HOLD TEMPERATURES DOWN SOME FROM SATURDAY'S HIGHS...THE MOIST ENVIRONMENT...DIURNAL HEATING AND PRESENCE OF A WEAK TROUGH ALOFT SHOULD RESULT IN SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING. WEAK WINDS FROM THE SURFACE-500 MB WILL LIMIT VERTICAL SHEAR...THOUGH STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT STRONG TO SEVERE WIND GUSTS. HOWEVER...THE STRONG CONVECTIVE OVERTURNING DURING THE PAST 24 HOURS AND LESS WARMING THAN SATURDAY SUGGESTS THE THREAT SHOULD BE TOO ISOLATED FOR A SLIGHT RISK. ..IMY/GRAMS.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 16:07:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 12:07:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031607 SWODY1 SPC AC 031605 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CDT SUN SEP 03 2006 VALID 031630Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER EXTREME ERN NEB AND WRN IA... ...ERN NEB/WRN IA... WELL-DEFINED COLD UPPER LOW OVER SERN SD IS FORECAST TO CONTINUE MOVING SEWD INTO NWRN IA THIS AFTERNOON AND CENTRAL IA TONIGHT. 500 MB TEMPERATURES OF -18 TO -20C ASSOCIATED WITH THE LOW WILL ENHANCE LOW-MID LEVEL LAPSE RATES...ESPECIALLY WHERE BREAKS IN CLOUD COVER ALLOW STRONGER DIURNAL HEATING TO OCCUR. ALTHOUGH SURFACE DEWPOINTS WILL LIKELY REMAIN IN THE LOW 50S...TEMPERATURES WARMING INTO THE LOW 70S WILL RESULT IN MODEST INSTABILITY WITH MLCAPE OF 500-1000 J/KG. DYNAMIC FORCING FOR ASCENT WILL BE AIDED BY LEFT EXIT REGION OF STRONG WESTERLY MID/UPPER LEVEL JET STREAK ON THE SRN PERIPHERY OF THE UPPER LOW. THIS WILL CONTRIBUTE TO SUFFICIENT DEEP LAYER SHEAR OF 35-45 KT TO AID STORM ORGANIZATION AND INTENSITY. CELLS ARE FORECAST TO INCREASE IN COVERAGE OVER EXTREME ERN NEB AND WRN IA BY EARLY AFTERNOON SPREADING EWD TOWARD CENTRAL IA BEFORE DIMINISHING IN INTENSITY DURING THE EVENING. ISOLATED LARGE HAIL WILL BE THE PRIMARY SEVERE THREAT. ...UPPER MS VALLEY... COLD FRONT WILL MOVE SLOWLY EWD ACROSS SERN MN/ERN IA TOWARD SWRN WI/NWRN IL THIS AFTERNOON. EXTENSIVE BAND OF CLOUDS AND WIDELY SCATTERED PRECIPITATION WITHIN THE FRONTAL ZONE WILL INHIBIT WIDESPREAD DIABATIC HEATING...ALTHOUGH ANY BREAKS IN THE CLOUD COVER THAT CAN DEVELOP WILL CONTRIBUTE TO DESTABILIZATION WITH MLCAPE AROUND 500 J/KG. THE POSSIBILITY OF ISOLATED NON-SUPERCELL TORNADO DEVELOPMENT /SIMILAR TO YESTERDAY ACROSS IA/ WILL BE MAINTAINED ALONG THE FRONT THIS AFTERNOON. ...AZ/SERN CA... DEEP LAYER MOISTURE CONTINUES TO SPREAD NWD FROM TROPICAL STORM JOHN INTO SOUTH CENTRAL/ERN AZ...AS MODERATE SWLY UPPER FLOW ACROSS THE LOWER CO RIVER VALLEY INTO WRN/NRN AZ RESULTS IN A SSW/NNE MID AND UPPER LEVEL MOISTURE DISCONTINUITY IN THE WATER VAPOR IMAGERY ACROSS CENTRAL AZ. 12Z SOUNDINGS INDICATE AMPLE PRECIPITABLE WATER VALUES OF 1.0-1.5 INCHES ACROSS CENTRAL/SRN AZ INTO SERN CA...AND CLEARING SKIES OVER WRN AZ/SERN CA WILL PERMIT STRONG DIURNAL HEATING TO OCCUR. THIS WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPE OF 1000-1500 J/KG. VERTICAL WIND PROFILES SHOW STRONGER ENELY MID LEVEL WINDS COMPARED TO YESTERDAY...WHICH MAY RESULT IN A STRONGER PROPAGATIONAL COMPONENT TO STORM MOTION DEVELOPING THIS AFTERNOON AND EVENING. A FEW STRONGER STORMS ARE EXPECTED ACROSS THIS REGION WITH POTENTIAL TO PRODUCE MARGINALLY SEVERE HAIL AND WET MICROBURSTS. ..WEISS/GUYER.. 09/03/2006  From swody1 at goshenarc.org Sun Sep 3 20:04:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 16:04:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032003 SWODY1 SPC AC 032001 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0301 PM CDT SUN SEP 03 2006 VALID 032000Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN NEB AND WRN IA... ...ERN NEB/WRN IA... UPPER LOW...CURRENTLY MOVING INTO NWRN IA...WILL CONTINUE TO TRACK SLOWLY TO THE ESE INTO IA THIS FORECAST PERIOD. ATTENDANT SURFACE LOW WITH THIS UPPER LOW WAS LOCATED OVER NERN NEB WITH A SURFACE FRONT EXTENDING WSWWD THROUGH SRN NEB. COLD MID LEVEL TEMPERATURES /-20 C AT 500 MB PER RUC GUIDANCE/ COMBINED WITH SURFACE HEATING AHEAD OF SURFACE FRONT HAS RESULTED IN STEEP LOW AND MID LEVEL LAPSE RATES. GIVEN FAVORABLE THERMODYNAMICS AND ASCENT WITHIN EXIT REGION OF MID LEVEL JET...ADDITIONAL STORMS ARE EXPECTED TO DEVELOP ALONG NEB/IA BORDER AND SPREAD INTO IA BEFORE DIMINISHING THIS EVENING WITH LOSS OF DAYTIME HEATING. STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES SUGGEST HAIL WILL BE THE PRIMARY THREAT. ...UPPER MS RIVER VALLEY... TRENDS IN WATER VAPOR IMAGERY SUGGEST A SHORT WAVE TROUGH IS ROTATING AROUND THE UPPER LOW AND CURRENTLY MOVING NWWD THROUGH SERN AND CENTRAL MN. ATTENDANT COLD FRONT ALONG LEADING EDGE OF UPPER LOW WILL SPREAD INTO SWRN WI AND NWRN IL...WHILE A POST-FRONTAL SURFACE TROUGH...EXTENDING SWD INTO ERN IA TO NERN MO...ACTS AS ANOTHER FOCUS FOR THUNDERSTORM DEVELOPMENT. EXTENSIVE CLOUDINESS IN THE VICINITY OF BOTH SURFACE BOUNDARIES HAS LIMITED DIABATIC HEATING...AND RESULTANT AVAILABLE INSTABILITY. ANY HEATING THAT CAN OCCUR YET THIS AFTERNOON SHOULD ALLOW FOR AT LEAST MARGINAL INSTABILITY. THIS COMBINED WITH ASCENT AHEAD OF UPPER LOW AND WITH SHORT WAVE TROUGH IS EXPECTED TO SUPPORT ADDITIONAL DIURNALLY DRIVEN STORMS FROM CENTRAL MN/WRN WI INTO ERN IA AND NWRN IL. WEAK INSTABILITY WILL LIMIT HAIL THREAT...WHILE THE POTENTIAL DOES EXIST FOR ISOLATED NON-SUPERCELL TORNADO DEVELOPMENT ALONG THE FRONT THIS AFTERNOON. ...AZ/SERN CA... STRONG SURFACE HEATING ACROSS SERN CA TO THE LOWER CO RIVER VALLEY WITHIN A MOIST AIR MASS HAS RESULTED IN A MODERATELY UNSTABLE AIR MASS. ADDITIONAL SURFACE HEATING ACROSS WRN AZ SHOULD SUPPORT SIMILAR TRENDS IN INSTABILITY. VISIBLE IMAGERY AND LIGHTNING DATA INDICATED THUNDERSTORMS HAVE BEGUN TO DEVELOP ACROSS THE HIGHER TERRAIN OF CENTRAL AND SERN AZ. GIVEN ENELY LOW-MID LEVEL WINDS...THERE WILL BE A GREATER POTENTIAL THIS FORECAST PERIOD FOR ACTIVITY TO PROPAGATE SWWD INTO THE LOWER ELEVATIONS WHERE INSTABILITY IS HIGHER AND SUPPORT WET MICROBURSTS. MARGINALLY SEVERE HAIL WILL ALSO BE A THREAT. ..PETERS.. 09/03/2006  From swody1 at goshenarc.org Mon Sep 4 00:37:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 03 Sep 2006 20:37:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040037 SWODY1 SPC AC 040036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 PM CDT SUN SEP 03 2006 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...IA... AN ARC OF DEEP CONVECTION IS ONGOING THIS EVENING FROM THE I-35 CORRIDOR N OF DSM SWWD TO THE LNK/BIE AREAS IN ADVANCE OF UPPER LOW OVER NWRN IA. THESE STORMS HAVE TENDED TO WEAKEN OVER THE PAST HOUR LIKELY AS A RESULT OF WEAKENING LOW-LEVEL LAPSE RATES AND RESULTANT INSTABILITY. SOME POTENTIAL FOR ISOLATED SEVERE STORMS CAPABLE OF SEVERE HAIL WILL EXIST FOR THE NEXT COUPLE OF HOURS...THOUGH THIS THREAT SHOULD DIMINISH AFTER 03Z AS THE BOUNDARY LAYER COOLS AND STABILIZES. ...SWRN AZ/SRN CA... WHILE BOUNDARY-LAYER IS NOT AS MOIST AS 24 HOURS PRIOR...DEWPOINTS IN THE UPPER 50S TO LOWER 60S COUPLED WITH STRONG HEATING TO THE NWRN OF T.S. JOHN CIRRUS CANOPY HAVE RESULTED IN A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF AROUND 1000 J/KG. TSTMS DEVELOPING ALONG THE MOGOLLON RIM AS WELL AS DENSITY CURRENT PROPAGATING WWD THROUGH PIMA COUNTY MAY INTENSIFY THIS EVENING WHILE ENCOUNTERING MORE UNSTABLE AIR MASS ALONG THE CO RIVER VALLEY. WIDESPREAD ORGANIZED STORMS ARE NOT ANTICIPATED OWING TO MARGINAL VERTICAL SHEAR...THOUGH POTENTIAL WILL EXIST FOR ISOLATED STRONG/SEVERE CELLS GIVEN THE STEEP LOW-LEVEL LAPSE RATES. LOCALLY DAMAGING WIND GUSTS WILL BE THE PRIMARY SEVERE WEATHER THREAT THROUGH THE REMAINDER OF THE EVENING. ..MEAD.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 05:24:15 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 01:24:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040524 SWODY1 SPC AC 040522 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1222 AM CDT MON SEP 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER FAR ERN IA...SRN WI AND NRN IL... ...SYNOPSIS... AMPLIFIED LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY ONE PERIOD AS MID AND UPPER-LEVEL LOW /NOW OVER IA/ CONTINUES SEWD INTO THE OH VALLEY AND UPSTREAM RIDGE INTENSIFIES FROM THE SWRN DESERTS INTO ALBERTA. IN THE LOW-LEVELS...WEAK SURFACE REFLECTION OF UPPER LOW WILL DEVELOP SEWD ACROSS ERN IA INTO WRN IL DURING THE AFTERNOON AND EVENING HOURS WITH TRAILING FRONTAL BOUNDARY EXTENDING SWWD INTO THE ARKLATEX. MEANWHILE TO THE E...A SECONDARY BAROCLINIC ZONE WILL EXIST FROM THE CNTRL/ERN GULF COAST NEWD TO A WEAK INFLECTION POINT OVER ERN TN AND THEN EWD ACROSS NC. ...FAR ERN IA/NRN IL/SRN WI... SIMILAR TO SUNDAY OVER WRN IA...A CONCENTRATED CLUSTER OF TSTMS IS FORECAST TO DEVELOP INVOF SURFACE AND UPPER LOWS THIS AFTERNOON WITHIN ENVIRONMENT CHARACTERIZED BY STEEP LOW TO MID-LEVEL LAPSE RATES AND RESULTANT SBCAPES OF 500-1000 J/KG. PRIMARY BELT OF STRONGER MID AND UPPER TROPOSPHERIC FLOW ASSOCIATED WITH THIS LOW ARE EXPECTED TO REMAIN DISPLACED TO THE S ACROSS SRN IL INTO CNTRL IND...WITH EFFECTIVE BULK SHEARS OF GENERALLY 20-30 KTS ACROSS AXIS OF STRONGEST INSTABILITY. DESPITE THE MODEST INSTABILITY AND SHEAR...THE STRONGEST STORMS WILL BE CAPABLE OF SEVERE HAIL GIVEN THE STEEP LAPSE RATES AND COOL THERMODYNAMIC PROFILES. ACTIVITY SHOULD TEND TO WEAKEN BY 01-02Z AS BOUNDARY LAYER COOLS AND STABILIZES. ...CO FRONT RANGE... INCREASING LOW-LEVEL ELY WIND COMPONENT WILL RESULT IN VERTICAL SHEAR PROFILES BECOMING SUPPORTIVE OF ORGANIZED/ROTATING STORMS LATER TODAY. PRIMARY UNCERTAINTY IS WHETHER DEEP...MOIST CONVECTION WILL INITIATE AND BECOME SUSTAINED. CURRENT WATER VAPOR IMAGERY INDICATES A SHORT WAVE TROUGH ROTATING SWD AROUND IA UPPER LOW ACROSS NERN WY...WITH LATEST SHORT TERM MODEL GUIDANCE MOVING THIS FEATURE GENERALLY SWD ACROSS ERN CO TODAY. THE BOUNDARY LAYER IS NOT EXPECTED TO BECOME PARTICULARLY WARM...THOUGH THE PRESENCE OF MODEST LOW-LEVEL MOISTURE /DEWPOINTS IN THE MID 40S TO LOW 50S/ COUPLED WITH STEEP LOW TO MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO POCKETS OF INSTABILITY WITH SBCAPES OF 500-700 J/KG. FORCING FOR ASCENT ASSOCIATED WITH THE SHORT WAVE TROUGH ALONG WITH THE SUSTAINED UPSLOPE FLOW MAY BE SUFFICIENT TO INITIATE A FEW STORMS THIS AFTERNOON OR EVENING IN THE IMMEDIATE LEE OF THE HIGHER TERRAIN. THE STRONGEST STORMS WILL BE CAPABLE OF SOME SEVERE HAIL AND LOCALLY GUSTY WINDS. ...SRN/CNTRL APPALACHIANS... LATEST MODEL GUIDANCE SUGGESTS THAT A WEAK...LOWER LATITUDE IMPULSE WILL TRANSLATE NEWD THROUGH THE MID SOUTH TOWARD THE REGION TODAY...LIKELY FOCUSING CONCENTRATED TSTM DEVELOPMENT ALONG SW-NE ORIENTED LOW-LEVEL FRONTAL ZONE. LAPSE RATES ARE NOT EXPECTED TO BECOME PARTICULARLY STEEP...THOUGH THE PRESENCE OF A MOIST BOUNDARY LAYER WILL CONTRIBUTE TO POCKETS OF INSTABILITY WITH SBCAPES OF 500-1000 J/KG. SOME INCREASE IN MID-LEVEL FLOW WILL ACCOMPANY THIS TROUGH...WITH VERTICAL SHEAR BECOMING MARGINALLY SUPPORTIVE OF A FEW ORGANIZED STORMS CAPABLE OF MAINLY WET MICROBURSTS. ..MEAD/GRAMS.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 12:46:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 08:46:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041247 SWODY1 SPC AC 041245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0745 AM CDT MON SEP 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NRN/CENTRAL IL...SRN WI AND FAR ERN IA... ...SYNOPSIS... CLOSED LOW OVER CENTRAL IA AND ASSOCIATED TROUGH OVER THE MID/UPPER MS VALLEY REGION WILL MOVE ESEWD AND AMPLIFY...AS UPPER RIDGE BUILDS NWD FROM THE NRN ROCKIES INTO THE CANADIAN ROCKIES. IN ASSOCIATION WITH THE UPPER LOW...A WEAK SURFACE LOW IN NWRN IL WILL MOVE EWD INTO NRN IND BY LATE AFTERNOON WITH A TRAILING FRONTAL BOUNDARY EXTENDING SWWD INTO SRN OK/WRN TX. FURTHER TO THE EAST...A STATIONARY FRONT STRETCHES FROM AL NEWD INTO WRN NC...AND THEN EWD INTO EXTREME SERN VA. ...FAR ERN IA/NRN IL/SRN WI... EARLY THIS MORNING...ONE BAND OF CONVECTION WAS LOCATED IN THE ZONE OF STRONG DIFFLUENCE ALOFT FROM ERN IL INTO SRN WI...WHILE ANOTHER CLUSTER OF STORMS WAS LOCATED JUST SOUTHEAST OF THE UPPER LOW. THE STORMS IN IA ARE EXPECTED TO MOVE/DEVELOP EWD WITH THE UPPER LOW INTO NRN/CENTRAL IL THIS AFTERNOON. DESPITE MEAGER BOUNDARY LAYER MOISTURE...MID LEVEL LAPSE RATES NEAR 7C/KM AND -16 TO -18C 500 MB TEMPERATURES WILL RESULT IN SBCAPES OF 500-1000 J/KG. ALTHOUGH THE PRIMARY BELT OF STRONGER MID AND UPPER LEVEL WINDS WILL BE ON THE SOUTHERN PERIPHERY OF THE LOW FROM CENTRAL MO EWD INTO SRN INDIANA...DEEP LAYER SHEAR AT 20-30 KT WILL SUPPORT MULTICELL CLUSTERS ACROSS THE OUTLOOK AREA. THE STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT WILL SUPPORT MARGINALLY SEVERE HAIL IN THE STRONGEST STORMS. THE STORMS SHOULD WEAKEN QUICKLY AFTER 00Z AS THE BOUNDARY LAYER COOLS AND STABILIZES. ...SRN/CNTRL APPALACHIANS... MODELS ARE CONSISTENT IN DEVELOPING CONVECTION OVER THE AREA LATE THIS AFTERNOON...THOUGH SOME DIFFERENCES EXIST IN EXACT LOCATION. A FEW SHOWERS HAD ALREADY FORMED FROM ERN TN NEWD INTO SWRN VA... IN ZONE OF WEAK ISENTROPIC LIFT NORTH OF STATIONARY FRONT. ALTHOUGH LIFT IS FORECAST TO WEAKEN THIS MORNING...MODELS DEPICT A HIGH LEVEL SHORTWAVE TROUGH...CURRENTLY OVER ERN OK...MOVING INTO TN/NRN MS BY LATE AFTERNOON. THIS FEATURE PLUS STRENGTHENING DIFFLUENCE ALOFT...AHEAD OF A 90-100 KT HIGH LEVEL JET MAX...WILL RESULT IN LARGE SCALE FORCING. ALTHOUGH TEMPERATURES NEAR 90 AND DEWPOINTS AROUND 70 SHOULD RESULT IN MLCAPES FROM 1500-2500 J/KG SOUTH OF THE FRONT...IT APPEARS THE MAIN FORCING WILL BE NORTH OF THE FRONT...WHERE INSTABILITY WILL BE WEAKER. HOWEVER...MUCAPES FROM 500 TO 1000 J/KG AND DEEP LAYER SHEAR NEAR 30 KT MAY SUPPORT ISOLATED STRONG/MARGINALLY SEVERE STORMS ACROSS PORTIONS OF ERN TN...NRN AL...WRN CAROLINAS AND WRN VA THIS AFTERNOON AND EVENING. ...CO AND NERN NM FRONT RANGE... DEEP ELY UPSLOPE WINDS WITH MID LEVEL WINDS VEERING TO NWLY WILL RESULT IN FAVORABLE VERTICAL SHEAR PROFILES FOR ORGANIZED/ROTATING STORMS THIS AFTERNOON. WATER VAPOR IMAGERY INDICATES A SHORT WAVE TROUGH WAS ROTATING SWD ACROSS ERN WY...AND LATEST MODEL GUIDANCE MAINTAINS THIS FEATURE IN ERN CO THROUGH THE AFTERNOON. THE BOUNDARY LAYER WILL NOT BE PARTICULARLY MOIST...THOUGH STEEP LOW/MID LEVEL LAPSE RATES SHOULD RESULT IN SBCAPES FROM 500-1000 J/KG. WEAK FORCING WITH SHORTWAVE TROUGH AND UPSLOPE FLOW MAY INITIATE A FEW STORMS WITH SEVERE HAIL/GUSTY WINDS OVER THE ERN FOOTHILLS MID/LATE AFTERNOON. A MORE STABLE ENVIRONMENT OVER THE PLAINS SHOULD LIMIT THE STORMS EWD EXTENT. SINCE STORM COVERAGE IS EXPECTED TO BE LIMITED...ONLY 5% HAIL/WIND PROBABILITIES ARE FORECAST. ..IMY/GRAMS.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 16:28:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 12:28:03 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041628 SWODY1 SPC AC 041626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CDT MON SEP 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDDLE AND UPPER MS VALLEY... ...MID/UPPER MS VALLEY... COLD UPPER LOW OVER IA IS EXPECTED TO CONTINUE MOVING ESEWD INTO NRN IL THIS AFTERNOON AND EVENING. ALTHOUGH THE MID LEVELS OF THE SYSTEM HAVE WARMED SLIGHTLY COMPARED TO YESTERDAY...500 MB TEMPERATURES OF -16 TO -18C WILL CONTRIBUTE TO MODERATELY STEEP LAPSE RATES ABOVE MODEST LOW LEVEL MOISTURE FIELD. VISIBLE IMAGERY SHOWS WIDESPREAD CLOUDS IN ADVANCE OF THE UPPER LOW OVER ERN IA/SRN WI AND NRN/CENTRAL IL...HOWEVER SEVERAL CLEAR SLOTS ARE EVIDENT OVER IL WHERE ENHANCED DIURNAL HEATING IS EXPECTED TO OCCUR. THIS WILL RESULT IN MESOSCALE ZONES OF GREATER INSTABILITY WHERE MLCAPE WILL REACH 500-1000 J/KG...WHICH SHOULD SUPPORT WIDELY SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING. MARGINALLY SEVERE HAIL AND ISOLATED STRONG WIND GUSTS WILL BE POSSIBLE WITH STRONGER CELLS. ...SRN APPALACHIANS... MOIST AIR MASS IS IN PLACE ACROSS THE SERN STATES WHERE SURFACE DEW POINTS ARE IN THE UPPER 60S/LOWER 70S. STRONG DIABATIC HEATING ACROSS NRN AL/NRN GA MAY ENHANCE THERMAL GRADIENT/DIFFERENTIAL HEATING BOUNDARY ACROSS THIS REGION AS CLOUDS PERSIST OVER ERN TN/ FAR NRN GA/SWRN NC AREA. HEATING WITHIN WEAKLY CAPPED ENVIRONMENT SHOULD ALLOW PARCELS TO REACH THEIR LFC WITH RESULTANT DEVELOPMENT OF SCATTERED THUNDERSTORMS. 20-30 KT WSWLY MID LEVEL WINDS WILL BE SUFFICIENT FOR MULTICELLULAR CLUSTERS TO DEVELOP WITH POTENTIAL FOR ISOLATED STRONG/MARGINALLY SEVERE STORMS THIS AFTERNOON AND EVENING. ...CO/NRN NM FRONT RANGE... WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH MOVING SSEWD TOWARD THE CENTRAL HIGH PLAINS WITH 25-30 KT NWLY MID LEVEL WINDS ACROSS THIS REGION. WIND PROFILES ARE EXPECTED TO EXHIBIT CONSIDERABLE VEERING WITH HEIGHT LATER THIS AFTERNOON WITH DEEP LAYER SHEAR OF 35-40 KT. LIMITING FACTOR FOR DEEP CONVECTION THIS AFTERNOON AND EVENING WILL BE THE MARGINAL LOW LEVEL MOISTURE WHICH WILL LIMIT MLCAPE VALUES TO AROUND 500 J/KG. ISOLATED STRONG THUNDERSTORMS MAY DEVELOP NEAR THE FRONT RANGE LATER THIS AFTERNOON AND EVENING WITH THREAT FOR HAIL/GUSTY WINDS BUT OVERALL COVERAGE APPEARS INSUFFICIENT TO SUPPORT A CATEGORICAL RISK AREA. ..WEISS/GUYER.. 09/04/2006  From swody1 at goshenarc.org Mon Sep 4 20:02:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 16:02:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042000 SWODY1 SPC AC 041959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT MON SEP 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF NRN IL... ...ERN IA THROUGH NRN IL AND SRN WI... ZONES OF ASCENT ACCOMPANYING VORTICITY MAXIMA ROTATING THROUGH UPPER LOW CENTERED OVER ERN IA ARE CONTRIBUTING TO THE DEVELOPMENT OF SCATTERED THUNDERSTORMS. POCKETS OF SURFACE HEATING BENEATH 500 MB TEMPERATURES OF -16C TO -18C HAVE RESULTED IN MARGINAL INSTABILITY WITH MLCAPE NEAR 500 J/KG. STORMS SHOULD CONTINUE DEVELOPING THE REMAINDER OF THE AFTERNOON. STRONGEST STORMS ARE EXPECTED OVER NRN IL INTO EXTREME SRN WI. SURFACE HEATING IS CO-LOCATED WITH SLIGHTLY HIGHER LOW LEVEL MOISTURE IN THIS REGION...AND ASCENT IS MORE FOCUSED ON SURFACE BOUNDARY ALONG ERN PERIPHERY OF EWD ADVANCING VORT MAX. THE THERMODYNAMIC ENVIRONMENT WITH MODERATELY STEEP LAPSE RATES AND COLD MID LEVEL TEMPERATURES IS SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS. OVERALL THREAT WILL REMAIN LIMITED BY MODEST INSTABILITY. ...S CNTRL CO... MUCH OF THE ASCENT ASSOCIATED WITH A VORT MAX MOVING SWD THROUGH THE NRN AND CNTRL HIGH PLAINS IS EXPECTED TO REMAIN N OF MOST OF CO THIS AFTERNOON. IN THE MEANTIME...WV IMAGERY AND FORECAST RUC SOUNDINGS SUGGEST THE ATMOSPHERE IN CNTRL AND SRN CO IS UNDER THE INFLUENCE OF LARGE SCALE SUBSIDENCE. THIS ALONG WITH LIMITED INSTABILITY IMPLIES THUNDERSTORM COVERAGE SHOULD REMAIN SPARSE AT BEST. IF ISOLATED STORMS DO MANAGE TO DEVELOP...STEEP LAPSE RATES AND DEEP LAYER SHEAR AROUND 40 KT WOULD SUPPORT A MARGINAL THREAT FOR ISOLATED HAIL. ..DIAL.. 09/04/2006  From swody1 at goshenarc.org Tue Sep 5 00:39:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 04 Sep 2006 20:39:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050039 SWODY1 SPC AC 050038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT MON SEP 04 2006 VALID 050100Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...ERN IA INTO NRN IL/SRN WI... AN ARCING CLUSTER OF TSTMS CONTINUES THIS EVENING AHEAD OF UPPER LOW FROM NEAR ORD SSWWD TO E OF DEC ALONG LOW-LEVEL BAROCLINIC ZONE. THIS ACTIVITY HAS TENDED TO WEAKEN OVER THE PAST 1-2 HOURS...AND SHOULD CONTINUE TO DO SO THROUGH THE REMAINDER OF THE EVENING AS BOUNDARY LAYER COOLS AND STABILIZES. DEEP LAYER FORCING FOR ASCENT AHEAD UPPER LOW COUPLED WITH EXISTING WEAK INSTABILITY /REF. 00Z ILX SOUNDING/ MAY SUPPORT A FEW STRONG STORMS THROUGH 02Z WITH THE PRIMARY THREAT BEING MARGINALLY SEVERE HAIL. ...CNTRL APPALACHIANS... A SMALL CLUSTER OF TSTMS HAS RECENTLY DEVELOPED OVER SERN TN / ENE OF CHA/ INVOF OF WEAK SURFACE LOW SITUATED ALONG SURFACE BOUNDARY EXTENDING FROM SERN MS TO NRN GA AND THEN ENEWD THROUGH CNTRL NC. OTHER STORMS ARE ALSO INTENSIFYING OVER CNTRL NC WITHIN A MOIST LOW-LEVEL AIR MASS WITH MUCAPES OF 500-1000 J/KG. WATER VAPOR IMAGERY SHOWS A FAIRLY STRONG SHORT WAVE TROUGH TRANSLATING EWD THROUGH THE TN AND SRN OH VALLEY...WHICH SHOULD SUPPORT AN INCREASE IN CONVECTIVE COVERAGE ACROSS THE CNTRL APPALACHIANS THIS EVENING. DESPITE THE MODEST INSTABILITY...BNA VWP INDICATES THE PRESENCE OF A 50 KT MID-LEVEL JET STREAK WHICH WILL SHIFT EWD ACROSS REGION TONIGHT...EFFECTIVELY ENHANCING VERTICAL SHEAR. THE MAJORITY OF TSTM ACTIVITY IS EXPECTED TO REMAIN SUB-SEVERE...HOWEVER THE INCREASING VERTICAL SHEAR MAY SUPPORT A FEW ORGANIZED STORMS CAPABLE OF MAINLY LOCALLY DAMAGING WINDS. ...WRN AZ INTO SERN CA... AN INTENSE CLUSTER OF TSTMS HAS RECENTLY DEVELOPED OVER SRN MOHAVE COUNTY WITHIN A HOT AND DEEPLY MIXED BOUNDARY LAYER WITH SBCAPES OF 1000-1500 J/KG. POTENTIAL WILL EXIST FOR THESE STORMS TO FORM A COLD POOL AND PROPAGATE SWWD ALONG THE CO RIVER VALLEY WHERE TEMPERATURES REMAIN 95-105 F. STRONG EVAPORATIONAL COOLING POTENTIAL IN THE SUB-CLOUD LAYER WILL BE SUPPORTIVE OF LOCALLY DAMAGING WINDS THROUGH THE REMAINDER OF THE EVENING. ..MEAD.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 05:30:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 01:30:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050530 SWODY1 SPC AC 050529 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 AM CDT TUE SEP 05 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER-LEVEL LOW OVER NRN IL/SRN WI IS FORECAST TO EVOLVE INTO A POSITIVELY TITLED OPEN WAVE FROM THE OH VALLEY INTO THE CNTRL GULF STATES WITH STRONGEST HEIGHT FALLS SHIFTING EWD INTO THE APPALACHIANS. IN THE LOW-LEVELS...PRIMARY BAROCLINIC ZONE INITIALLY SITUATED ALONG THE CNTRL/SRN APPALACHIANS WILL SHIFT EWD TODAY THROUGH THE PIEDMONT INTO THE COASTAL PLAIN WITH SEVERAL WEAK WAVES DEVELOPING NEWD ALONG THIS BOUNDARY. ...OH VALLEY... CORE OF UPPER LOW HAS SLOWLY MODIFIED OVER THE PAST COUPLE OF DAYS...RESULTING IN PROGRESSIVELY WEAKER INSTABILITY. STILL...MID-LEVEL TEMPERATURES ARE EXPECTED TO REMAIN BETWEEN -14 AND -16 C AT 500 MB...AND WHEN COUPLED WITH DAYTIME HEATING...AIR MASS WILL BECOME WEAKLY UNSTABLE WITH SBCAPES OF AROUND 500 J/KG. TSTMS WILL BECOME INCREASINGLY WIDESPREAD THIS AFTERNOON WITHIN DESTABILIZING ENVIRONMENT FROM PORTIONS OF ERN IL EWD THROUGH IND INTO WRN OH. THE RELATIVELY WEAK INSTABILITY AND MARGINAL VERTICAL SHEAR WILL LIMIT A MORE ORGANIZED SEVERE THREAT...THOUGH THE MOST INTENSE STORMS WILL BE CAPABLE OF SOME SEVERE HAIL INTO THE EARLY EVENING HOURS. ...CNTRL/SRN APPALACHIANS EWD TO THE ATLANTIC COAST... LOW-LEVEL AIR MASS WILL REMAIN QUITE MOIST E OF SURFACE FRONT WITH DEWPOINTS IN THE UPPER 60S TO LOW 70S...THOUGH WEAK LAPSE RATES SHOULD LIMIT SBCAPES TO 1000-1500 J/KG. INCREASING HEIGHT FALLS AHEAD OF EVOLVING MID-LEVEL TROUGH SHOULD SUPPORT AN INCREASE IN TSTM COVERAGE AND INTENSITY THIS AFTERNOON ACROSS THE PIEDMONT AND COASTAL PLAIN FROM CNTRL/SRN GA NEWD INTO ERN VA. IT APPEARS THAT THE STRONGER MID AND HIGH-LEVEL WIND FIELDS ASSOCIATED WITH UPPER TROUGH WILL LAG SURFACE WARM SECTOR TO THE W WITH GENERALLY 20-30 KTS OF DEEP LAYER SHEAR FORECAST ACROSS AXIS OF STRONGEST INSTABILITY. A FEW ORGANIZED STORMS /SOME EXHIBITING EPISODIC MID-LEVEL ROTATION/ WILL BE POSSIBLE WITH A THREAT OF LOCALLY DAMAGING WINDS AND PERHAPS A BRIEF TORNADO. HOWEVER...THE MARGINAL VERTICAL SHEAR AND WEAK LAPSE RATES SHOULD LIMIT A MORE SIGNIFICANT SEVERE WEATHER THREAT. ...S-CNTRL/SERN CO INTO NERN NM... LOW-LEVEL UPSLOPE REGIME IS EXPECTED TO PERSIST THROUGH THE PERIOD...MAINTAINING MODEST LOW-LEVEL MOISTURE WITH DEWPOINTS IN THE 40S TO LOWER 50S. WHEN COUPLED WITH DAYTIME HEATING AND STEEPENING LAPSE RATES...ENVIRONMENT WILL BECOME WEAKLY UNSTABLE WITH SBCAPES OF 500 J/KG. A WEAK IMPULSE OBSERVED ON WATER VAPOR IMAGERY OVER NRN UT WILL TURN MORE SEWD TODAY...COMBINING WITH THE SUSTAINED LOW-LEVEL OROGRAPHIC FORCING TO INITIATE DIURNAL STORMS OVER S-CNTRL CO. TSTMS SHOULD THEN MOVE/DEVELOP SEWD INTO NERN NM BY THIS EVENING. STRONG LOW-LEVEL VEERING BENEATH 20-30 KT NNWLY MID-LEVEL FLOW WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR UPDRAFT ROTATION. HOWEVER...THE MARGINAL INSTABILITY SHOULD LIMIT THE POTENTIAL FOR MORE WIDESPREAD...ORGANIZED STORM DEVELOPMENT. STILL...A FEW OF THE MORE INTENSE CELLS WILL BE CAPABLE OF MARGINALLY SEVERE HAIL. ..MEAD/JEWELL.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 12:39:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 08:39:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051239 SWODY1 SPC AC 051237 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0737 AM CDT TUE SEP 05 2006 VALID 051300Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER-LEVEL LOW OVER NRN IL IS FORECAST TO SHIFT ESEWD AND GRADUALLY EVOLVE INTO A POSITIVELY TILTED OPEN WAVE FROM THE OH VALLEY SWD INTO THE CENTRAL GULF STATES. PRIMARY BAROCLINIC ZONE...SITUATED THIS MORNING FROM AL NEWD INTO SERN VA...WILL SHIFT SEWD THIS AFTERNOON AND TONIGHT AS THE UPPER TROUGH APPROACHES FROM THE WEST. MOISTURE TRAPPED UNDER UPPER RIDGE IN THE WEST WILL RESULT IN SCATTERED THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND OVER THE HIGHER TERRAIN. ALTHOUGH THE SEVERE POTENTIAL WILL BE LOW ACROSS THE CONUS DUE TO LIMITED INSTABILITY AND WEAK FORCING...A FEW MARGINAL SEVERE WEATHER EVENTS ARE POSSIBLE ACROSS PORTIONS OF THE OH VALLEY...GA NEWD INTO SRN VA AND IN FOOTHILLS OF SRN CO INTO NERN NM. ...OH VALLEY... SCATTERED THUNDERSTORMS CONTINUED EARLY THIS MORNING...EAST AND SOUTH OF THE UPPER LOW. THIS CONVECTION WILL SPREAD SLOWLY EWD AND INTENSIFY SLIGHTLY AS DIURNAL HEATING RESULTS IN SBCAPES UP TO 1000 J/KG. GIVEN COLD 500 MB TEMPERATURES FROM -14 TO -16C...MARGINALLY SEVERE HAIL IS POSSIBLE WITH A FEW STORMS. HOWEVER...THE RELATIVELY WEAK INSTABILITY AND MARGINAL VERTICAL SHEAR WILL LIMIT THE SEVERE POTENTIAL. ...GA NEWD INTO SRN VA... SURFACE ANALYSIS INDICATES THAT A WEAK WAVE WAS LOCATED ALONG THE FRONT IN NRN GA. THE MODELS LIFT THIS FEATURE NEWD AND OFF THE SERN VA COAST TONIGHT. THE SEWD PUSH OF THE FRONT COMBINED WITH 30-60M HEIGHT FALLS SHOULD PROVIDE SUFFICIENT LIFT FOR NUMEROUS THUNDERSTORMS TO DEVELOP ALONG AND EAST OF THE FRONT TODAY AND INTO THE EVENING HOURS. ALTHOUGH THE BOUNDARY LAYER WILL REMAIN QUITE MOIST EAST OF THE FRONT WITH DEWPOINTS IN THE LOWER 70S...WEAK LAPSE RATES SHOULD LIMIT SBCAPES TO 1000-2000 J/KG. ALSO...THE STRONGER MID AND HIGH-LEVEL WINDS ASSOCIATED WITH THE UPPER TROUGH WILL REMAIN BEHIND THE COLD FRONT...WITH THE WARM SECTOR DEEP LAYER SHEAR EXPECTED TO ONLY RANGE FROM 20-30 KT. UNIDIRECTIONAL SWLY WINDS ABOVE THE BOUNDARY LAYER SUGGESTS SOME STORMS MAY DEVELOP INTO SMALL LINES WITH THE POSSIBILITY OF ISOLATED STRONG/SEVERE WIND GUSTS. HOWEVER...THE COMBINATION OF WEAK FORCING AND POOR LAPSE RATES SHOULD LIMIT THE SEVERE POTENTIAL. ...EXTREME SOUTH CENTRAL CO AND NERN NM... LOW-LEVEL ESELY UPSLOPE FLOW SHOULD MAINTAIN DEWPOINTS IN THE 40S TO LOWER 50S...DESPITE STRONG MIXING. STRONG HEATING AND STEEP MID LEVEL LAPSE RATES SHOULD YIELD AFTERNOON SBCAPES NEAR 500 J/KG. THE ELEVATED HEAT SOURCE WILL AID IN LATE AFTERNOON INITIATION OVER THE HIGHER TERRAIN OF FAR SRN CO AND NERN NM. ONCE STORMS FORM...STRONG LOW-LEVEL VEERING BENEATH 20-30 KT NNWLY MID-LEVEL WINDS WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR STORMS TO ROTATE. ALTHOUGH HAIL IS POSSIBLE WITH A STORM OR TWO...THE MEAGER MOISTURE AND INSTABILITY IS EXPECTED TO LIMIT THE NUMBER OF STORMS AND OVERALL SEVERE WEATHER THREAT. ..IMY/JEWELL.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 16:30:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 12:30:08 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051628 SWODY1 SPC AC 051626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CDT TUE SEP 05 2006 VALID 051630Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...CAROLINAS AREA THIS AFTERNOON/EVENING... THE MID LEVEL LOW OVER IL WILL BEGIN TO PROGRESS EWD AS AN OPEN WAVE...IN RESPONSE TO UPSTREAM HEIGHT FALLS ASSOCIATED WITH ANOTHER TROUGH DIGGING SEWD OVER ONTARIO. WEAK SURFACE WAVES ALONG A FRONT FROM THE PIEDMONT TO THE TIDEWATER AREA SHOULD CONSOLIDATE AS A SINGLE LOW AND MOVE NEWD OFF THE MID ATLANTIC COAST TONIGHT...IN ADVANCE OF THE OH VALLEY MID LEVEL TROUGH. SEVERAL CLUSTERS OF THUNDERSTORMS ARE EXPECTED TODAY IN ASSOCIATION WITH THE WEAK CYCLOGENESIS AND DAYTIME HEATING WITHIN THE MOIST WARM SECTOR. THE ERN FRINGE OF THE STRONGER /30 KT/ MID LEVEL FLOW WILL OVERLAP THE WRN FRINGE OF THE WARM SECTOR THIS AFTERNOON...AND A FEW ORGANIZED MULTICELL CLUSTERS WILL BE POSSIBLE INVOF THE SURFACE FRONT. GIVEN THE MODERATE INSTABILITY /MLCAPE VALUES OF 1000-2000 J/KG/ IN THE WARM SECTOR...THE STRONGEST STORMS MAY PRODUCE STRONG/ISOLATED DAMAGING OUTFLOW WINDS. ...SRN HIGH PLAINS THIS AFTERNOON/EVENING... WEAK LOW-LEVEL UPSLOPE FLOW AND BOUNDARY LAYER DEWPOINTS IN THE 50S WILL PERSIST TODAY BENEATH NLY/NWLY MID-UPPER FLOW...AND WATER VAPOR IMAGERY SHOWS A SPEED MAX ROTATING SSEWD FROM ERN CO TOWARD EXTREME NE NM AND THE NW TX PANHANDLE. AFTERNOON TEMPERATURES FROM 68-72 F W OF THE THICKER STRATUS WILL CONTRIBUTE TO MLCAPE VALUES OF 500-1000 J/KG IN AN ENVIRONMENT WITH SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS /30-40 KT OF BULK SHEAR IN LOWEST 6 KM/. A FEW THUNDERSTORMS SHOULD DEVELOP ACROSS NE NM AND THE NW TX PANHANDLE BY MID AFTERNOON...THE STRONGEST OF WHICH COULD PRODUCE ISOLATED MARGINALLY SEVERE HAIL THROUGH THIS EVENING. ...IL/INDIANA TODAY... THE COLD CORE MID LEVEL LOW OVER IL WILL GRADUALLY EVOLVE INTO MORE OF AN OPEN WAVE AND MOVE EWD OVER INDIANA THROUGH TONIGHT. CONVECTION IS ONGOING IN ASSOCIATION WITH THE MID LEVEL COLD POOL...AND SOME ADDITIONAL DESTABILIZATION IS POSSIBLE WHERE CLOUD BREAKS ALLOW SOME SURFACE HEATING. HOWEVER...RATHER MODEST MID LEVEL LAPSE RATES /6.5 C/KM/ AND WEAK VERTICAL SHEAR APPEAR SUPPORTIVE OF ONLY MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS THIS AFTERNOON. ..THOMPSON/CROSBIE.. 09/05/2006  From swody1 at goshenarc.org Tue Sep 5 19:36:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 05 Sep 2006 15:36:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051935 SWODY1 SPC AC 051933 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0233 PM CDT TUE SEP 05 2006 VALID 052000Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY AREA... UPPER LOW CENTERED OVER CNTRL IL CONTINUES MOVING SLOWLY EWD. COOL MID LEVEL TEMPERATURES NEAR UPPER LOW CENTER WITH -16C AT 500 MB AND POCKETS OF SURFACE HEATING HAVE RESULTED IN MODERATELY STEEP LOW TO MID LEVEL LAPSE RATES AND MLCAPE NEAR 500 J/KG. ZONES OF ASCENT ASSOCIATED WITH SEVERAL VORTICITY MAXIMA ROTATING AROUND THE UPPER LOW WILL CONTINUE TO PROMOTE THUNDERSTORM DEVELOPMENT THIS AFTERNOON AS THE BOUNDARY LAYER DESTABILIZES. THE THERMODYNAMIC ENVIRONMENT MAY BE SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL THROUGH EARLY EVENING. ...SERN STATES... SURFACE HEATING AND BOUNDARY LAYER DEWPOINTS IN THE LOW 70S HAVE RESULTED IN MODERATE INSTABILITY WITHIN THE PRE-FRONTAL WARM SECTOR FROM PORTIONS OF GA NEWD THROUGH THE ERN CAROLINAS. HOWEVER...WEAK MID LEVEL LAPSE RATES ARE LIMITING MLCAPE TO AOB 1500 J/KG. NUMEROUS THUNDERSTORMS CONTINUE DEVELOPING ALONG THE FRONT AND WITHIN THE WEAKLY CAPPED WARM SECTOR. ISOLATED WET MICROBURSTS AND PERHAPS MARGINALLY SEVERE HAIL COULD ACCOMPANY THE STRONGER STORMS. HOWEVER...POOR LAPSE RATES AND MODEST LARGELY UNIDIRECTIONAL SWLY VERTICAL WIND PROFILES WILL LIMIT OVERALL THREAT. ...CNTRL AND SRN HIGH PLAINS... ISOLATED STORMS DEVELOPING ALONG CONVERGENCE BOUNDARY FROM SERN CO INTO THE WRN TX PANHANDLE MAY BECOME CAPABLE OF PRODUCING ISOLATED STRONG WIND GUSTS AND HAIL. SEVERE COVERAGE IS NOT EXPECTED TO BECOME SUFFICIENT TO WARRANT A SLIGHT RISK. SEE SWOMCD 1933 FOR MORE INFORMATION. ..DIAL.. 09/05/2006  From swody1 at goshenarc.org Fri Sep 8 05:46:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 01:46:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080547 SWODY1 SPC AC 080545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT FRI SEP 08 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM LOWER MI TO NERN IA... ...GREAT LAKES TO NERN IA... WEAK HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES WITHIN BASE OF DEEPER TROUGH THAT EXTENDS INTO HUDSON BAY REGION OF CANADA. AT THE SFC...DOMINANT ANTICYCLONE OVER CNTRL CANADA WILL BUILD SWD FORCING A COLD FRONT INTO NRN LOWER MI/CNTRL WI AROUND PEAK HEATING...TRAILING SWWD INTO IA. LATEST MODEL GUIDANCE SUGGEST BOUNDARY LAYER WILL ONCE AGAIN HEAT RAPIDLY DUE TO DEEP WSWLY FLOW FROM THE CNTRL PLAINS INTO WI. IT APPEARS CONVECTIVE TEMPERATURES WILL EASILY BE REACHED WITH LOWER 80S EXPECTED BY 19-20Z ACROSS THE WARM SECTOR. IN THE ABSENCE OF DEEP ASCENT ALONG SHALLOW CONVERGENT WIND SHIFT...UPDRAFTS SHOULD DEVELOP QUICKLY...BUT STRUGGLE TO MAINTAIN ORGANIZED STRUCTURES. EVEN SO...THUNDERSTORMS MAY PRODUCE HAIL QUICKLY IN THEIR LIFE CYCLE BEFORE DECAYING AND STABILIZING THE FRONTAL ZONE. GREATEST THREAT FOR DEEP CONVECTION IS ACROSS LOWER MI INTO WI...WHILE ACTIVITY SHOULD BE ISOLATED IN NATURE ACROSS IA INTO NERN NEB. LOSS OF AFTERNOON HEATING WILL PROVE DETRIMENTAL TO ANY SEVERE THREAT ALTHOUGH WEAK STORMS MAY ACCOMPANY THE BOUNDARY THROUGH THE OVERNIGHT HOURS INTO NRN IL/SRN LOWER MI. ...SWRN U.S... HIGHER PRECIPITABLE WATER CONTINUES ACROSS MUCH OF THE LOWER DESERTS OF SRN CA/AZ THIS MORNING WITH VALUES ON THE ORDER OF 1.5 INCHES MANY AREAS. WEAK UPPER TROUGHING WILL SHIFT EWD ACROSS THE 4-CORNERS REGION LATER TODAY WHICH WILL ENHANCE/SPREAD CONVECTIVE THREAT INTO ERN AZ/NM. NUMEROUS SHOWERS/THUNDERSTORMS WILL DEVELOP AHEAD OF UPPER TROUGH LATER TODAY AND A FEW OF THESE MAY PRODUCE MARGINALLY SEVERE HAIL OR PERHAPS SOME GUSTY WINDS. ..DARROW/JEWELL.. 09/08/2006  From swody1 at goshenarc.org Fri Sep 8 12:54:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 08:54:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081253 SWODY1 SPC AC 081252 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 AM CDT FRI SEP 08 2006 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE UPPER MS VALLEY AND GREAT LAKES... ...SYNOPSIS... HIGH AMPLITUDE SPLIT FLOW PATTERN WILL CONTINUE TODAY AS BROAD UPPER TROUGH MOVES ESEWD ACROSS ERN CANADA AND ADJACENT PARTS OF THE UPPER MS VALLEY/GREAT LAKES...WHILE UPSTREAM TROUGH MOVES ONSHORE INTO THE PACIFIC NW TONIGHT. A WEAKER TROUGH OVER THE GREAT BASIN REGION IS FORECAST TO MOVE EWD ACROSS THE CENTRAL ROCKIES TOWARD THE CENTRAL HIGH PLAINS. AT THE SURFACE...A STRONG COLD FRONT FROM ERN ONTARIO ACROSS NRN WI/SRN MN AND SD WILL CONTINUE MOVING SEWD REACHING A ST LAWRENCE VALLEY/SRN LOWER MI/SRN IA/SRN NEB LINE BY 09/12Z. ...UPPER MS VALLEY/GREAT LAKES... PLUME OF STEEPER MID LEVEL LAPSE RATES EXTENDING FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY IS FORECAST TO PERSIST INTO THIS EVENING. THIS WILL ENHANCE INSTABILITY ALONG AND IMMEDIATELY AHEAD OF THE ADVANCING COLD FRONT WHERE SURFACE DEW POINTS OF 55-60F WILL CONTRIBUTE TO MLCAPE OF 1000-1500 J/KG. WIDELY SCATTERED CONVECTION IS LIKELY TO CONTINUE ACROSS THIS REGION THIS MORNING...WITH MORE VIGOROUS THUNDERSTORMS EXPECTED TO DEVELOP THIS AFTERNOON MAINLY ALONG THE FRONT AS DIURNAL HEATING CONTRIBUTES TO DESTABILIZATION. THE ACTIVITY MAY INITIALLY DEVELOP BY EARLY AFTERNOON FROM ERN UPPER MI/NRN LOWER MI WSWWD INTO PARTS OF WI...THEN GRADUALLY BUILD WWD THROUGH THE AFTERNOON ALONG THE FRONT INTO PARTS OF IA AND POSSIBLY NRN NEB. STRONGER MID LEVEL WINDS WILL EXTEND SWD AS FAR AS NRN/CENTRAL WI AND NRN LOWER MI WHERE DEEP LAYER SHEAR OF 25-35 KT WILL AID IN DEVELOPMENT OF ORGANIZED STORMS. A FEW SEVERE STORMS WILL BE POSSIBLE ACROSS PARTS OF THE UPPER GREAT LAKES/UPPER MS VALLEY DURING THE AFTERNOON AND EVENING WITH PRIMARY THREAT FOR LARGE HAIL AND STRONG WIND GUSTS. ...AZ/WRN NM REGION... MOST OF THE NOCTURNAL CONVECTION OVER WRN AZ AND EXTREME SERN CA HAS SLOWLY WEAKENED DURING THE LAST SEVERAL HOURS ALTHOUGH SEVERAL STRONG STORMS ARE CONTINUING NEAR YUM AND SW OF CGZ. THESE STORMS ARE EXPECTED TO MOVE SEWD AND GRADUALLY DIMINISH IN INTENSITY AFTER SUNRISE. AMPLE MOISTURE REMAINS ACROSS THE AREA WITH PRECIPITABLE WATER VALUES OF 1.25-1.50 INCHES INDICATED BY GPS WATER VAPOR SENSORS AND 12Z TUS/PHX SOUNDINGS...AND DRY AIR IN THE MID/UPPER LEVELS WILL ENHANCE CONVECTIVE INSTABILITY. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF NORTH CENTRAL/ERN AZ AND WRN NM THIS AFTERNOON AND EVENING AS THE UPPER TROUGH CONTINUES EWD. THIS CONVECTION IS EXPECTED TO MOVE EWD/SEWD THROUGH TONIGHT WITH STRONGER STORMS CAPABLE OF PRODUCING STRONG WIND GUSTS AND MARGINALLY SEVERE HAIL. ..WEISS/JEWELL.. 09/08/2006  From swody1 at goshenarc.org Fri Sep 8 19:59:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 15:59:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 082002 SWODY1 SPC AC 081959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT FRI SEP 08 2006 VALID 082000Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE GREAT LAKES REGION... ...GREAT LAKES AREA... A COLD FRONT FROM NRN LOWER MI SWWD THROUGH NRN WI AND INTO SRN MN WILL CONTINUE SWD IN ADVANCE OF A SHORTWAVE TROUGH ADVANCING SEWD THROUGH SRN ONTARIO. THE ATMOSPHERE IS DESTABILIZING IN ADVANCE OF THE FRONT AS SURFACE TEMPERATURES WARM INTO THE 80S. INSTABILITY HAS BEEN SOMEWHAT TEMPERED BY PRE-FRONTAL ELEVATED CONVECTION AND MODEST LOW LEVEL MOISTURE. HOWEVER...SURFACE HEATING AND MODERATELY STEEP LOW-MID LEVEL LAPSE RATES ARE CONTRIBUTING TO MLCAPE FROM 1000 TO 1500 J/KG. SURFACE BASED STORMS ARE EXPECTED TO INCREASE ALONG AND IN ADVANCE OF THE FRONT AS THE BOUNDARY LAYER DESTABILIZES. WLY UNIDIRECTIONAL WIND PROFILES WITH 25 TO 30 KT BETWEEN 850-500 MB AND WEAK VERTICAL SHEAR WILL SUPPORT MOSTLY MULTICELLS S OF THE FRONT. VERTICAL SHEAR NEAR AND N OF FRONT IS SUFFICIENT FOR SOME SUPERCELL STRUCTURES...BUT ACTIVITY IN POST FRONTAL ENVIRONMENT SHOULD REMAIN ELEVATED. SOME STORMS MAY EVOLVE INTO LINE SEGMENTS AND SMALL CLUSTERS AS THEY DEVELOP SEWD. ISOLATED DAMAGING WIND AND HAIL WILL BE POSSIBLE THROUGH EARLY EVENING. ...SWRN U.S.... THE ATMOSPHERE IS DESTABILIZING OVER AZ INTO WRN NM AS A RESULT OF STRONG SURFACE HEATING WITH MLCAPE FROM 500 TO 1000 J/KG. STORMS WILL CONTINUE TO DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON. ACTIVITY HAS BEEN MORE NUMEROUS OVER NM WHERE THERMODYNAMIC PROFILES HAVE BEEN MODIFIED BY ASCENT ACCOMPANYING AN EWD ADVANCING SHORTWAVE TROUGH. HOWEVER...INSTABILITY AND LAPSE RATES ARE MORE LIMITED IN THIS REGION. FARTHER W ACROSS AZ...LARGE SCALE SUBSIDENCE IN WAKE OF THE SHORTWAVE TROUGH HAS CONTRIBUTED TO DRYER MIDDLE AND HIGH LEVEL THERMODYNAMIC PROFILES. AS A RESULT...STORMS SHOULD REMAIN VERY ISOLATED. STRONG WIND GUSTS OR HAIL COULD ACCOMPANY THE STRONGER STORMS...BUT COVERAGE OF SEVERE IS EXPECTED TO REMAIN RATHER SPARSE. ..DIAL.. 09/08/2006  From swody1 at goshenarc.org Sat Sep 9 00:37:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 08 Sep 2006 20:37:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090039 SWODY1 SPC AC 090036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 PM CDT FRI SEP 08 2006 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NERN NEB TO LOWER MI... LOSS OF SFC HEATING WILL ADVERSELY AFFECT ONGOING THUNDERSTORM ACTIVITY FROM NERN NEB/NRN IA INTO CNTRL LOWER MI OVER THE NEXT FEW HOURS. IN THE ABSENCE OF MEANINGFUL LARGE SCALE ASCENT...IT APPEARS WEAKENING LOW LEVEL LAPSE RATES AND STABILIZING BOUNDARY LAYER SHOULD RESULT IN FEEBLE UPDRAFTS BY 03Z. IN THE SHORT TERM...FRONTAL CONVERGENCE MAY SUSTAIN A FEW STRONGER STORMS CAPABLE OF GENERATING MARGINALLY SEVERE HAIL OR GUSTY WINDS. ...SERN CA/AZ... MAIN SHORTWAVE TROUGH AXIS HAS MOVED EAST OF THE LOWER DESERT REGIONS OF AZ THIS EVENING. WV IMAGERY SUPPORTS THIS WITH MUCH DRIER MID LEVELS AND ONLY ISOLATED THUNDERSTORM DEVELOPMENT WITHIN WNWLY FLOW REGIME. WEAK LARGE SCALE VERTICAL MOTION SHOULD NOT ENHANCE ORGANIZATIONAL POTENTIAL WITH THIS ACTIVITY AS BOUNDARY LAYER COOLS. A FEW STORMS COULD GENERATE SOME WIND OR SMALL HAIL BUT OVERALL THIS ACTIVITY SHOULD GRADUALLY DECREASE OVER THE NEXT SEVERAL HOURS. ..DARROW.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 05:53:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 01:53:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090556 SWODY1 SPC AC 090554 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT SAT SEP 09 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...NEW ENGLAND/OH VALLEY... PROGRESSIVE TROUGH OVER SERN CANADA WILL ALLOW SWLY FLOW/DEEP LAYER SHEAR TO INCREASE ACROSS THE NERN U.S. LATER TODAY. IN THE WAKE OF THIS UPPER TROUGH...SFC ANTICYCLONE WILL BUILD EWD AND A FORCE A RATHER SIGNIFICANT FRONT INTO NRN NEW ENGLAND BY 18Z...TRAILING SWWD INTO NRN OH/IND. LATEST GUIDANCE SUGGEST WARM SECTOR LAPSE RATES WILL STEEPEN THOUGH 3KM...IN EXCESS OF 8 C/KM...AS AIRMASS WARMS AND THUNDERSTORMS SHOULD DEVELOP ALONG/BEHIND WIND SHIFT AS IT ADVANCES ACROSS THE REGION. FORECAST SOUNDINGS SUGGEST INSTABILITY WILL BE SOMEWHAT LACKING WITH SBCAPE VALUES GENERALLY AOB 1000 J/KG. IT APPEARS 25-30KT ESEWD STORM MOTION CAN BE EXPECTED WITH MOST UPDRAFTS AS THEY STRUGGLE TO STAY AHEAD OF SURGING FRONTAL ZONE. GUSTY WINDS CAN CERTAINLY BE EXPECTED...ALONG WITH MARGINALLY SEVERE HAIL. IT APPEARS INSTABILITY/SHEAR WILL PROVE A BIT TOO MEAGER TO WARRANT AN ORGANIZED SEVERE EVENT ACROSS THIS REGION. ...CNTRL/SRN HIGH PLAINS... MULTIPLE VORT MAXIMA ARE NOTED WITHIN BROAD TROUGH ACROSS THE GREAT BASIN/CNTRL/SRN ROCKIES EARLY THIS MORNING. CONSIDERABLE AMOUNT OF CONVECTION HAS OCCURRED BENEATH THIS TROUGH THE LAST FEW DAYS...EXTENDING A GOOD DISTANCE DOWNSTREAM INTO THE CNTRL HIGH PLAINS REGION. THIS HAS EFFECTIVELY NEUTRALIZED LAPSE RATE ENVIRONMENT WHICH WILL LIKELY LIMIT INSTABILITY ACROSS THE HIGH PLAINS SOUTH OF FRONTAL ZONE. EVEN SO...WEAK LEE CYCLOGENESIS SHOULD OCCUR OVER NERN NM DURING THE AFTERNOON WITH A PSEUDO DRYLINE SERVING TO FOCUS POTENTIAL CONVECTIVE DEVELOPMENT. ADDITIONALLY...A WEAK LLJ SHOULD DEVELOP IN RESPONSE TO THE APPROACHING UPPER TROUGH AND THIS SHOULD AID THUNDERSTORM ACTIVITY ALONG/NORTH OF FRONTAL ZONE FROM ERN CO INTO WRN KS. A FEW STORMS ACROSS THE WARM SECTOR MAY EXHIBIT WEAK SUPERCELL CHARACTERISTICS AS BROAD VEERING PROFILES WILL FAVOR STORM ROTATION. ISOLATED HAIL OR PERHAPS A MARGINALLY SEVERE WIND GUST COULD OCCUR WITH THIS CONVECTION. ..DARROW/GUYER.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 12:55:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 08:55:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091257 SWODY1 SPC AC 091256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT SAT SEP 09 2006 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... HIGH AMPLITUDE FLOW PATTERN IS FORECAST TO PERSIST TODAY WITH PRIMARY BAND OF WESTERLIES CURVING FROM BRITISH COLUMBIA INTO CENTRAL CANADA THEN SEWD ACROSS THE UPPER GREAT LAKES/ST LAWRENCE VALLEY. A SHORT WAVE TROUGH WILL MOVE EWD FROM THE NRN GREAT LAKES ACROSS NEW ENGLAND...FORCING A STRONG SURFACE COLD FRONT SEWD ACROSS THE NERN STATES AND THE OH VALLEY. THIS BOUNDARY WILL EXTEND WWD AS A QUASI-STATIONARY FRONT INTO THE CENTRAL PLAINS. IN THE WEST...A BROAD UPPER TROUGH WITH MULTIPLE VORTICITY MAXIMA ACROSS THE GREAT BASIN/CENTRAL ROCKIES WILL PROGRESS EWD INTO CENTRAL PLAINS. SURFACE LOW PRESSURE DEVELOPING OVER SERN CO WILL MOVE SLOWLY EWD INTO KS BY THE END OF THE PERIOD. A DRY LINE IS EXPECTED TO DEVELOP SWD FROM THE LOW THIS AFTERNOON NEAR THE TX/NM BORDER. ...NEW ENGLAND INTO OH... CONVECTION ALONG/AHEAD OF THE ADVANCING COLD FRONT HAS BEEN SLOWLY INCREASING THIS MORNING FROM SRN LAKE ERIE INTO WRN PA...AND ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP NEWD ALONG THE FRONT INTO NRN NEW ENGLAND LATER THIS MORNING AND EARLY AFTERNOON. THE DEGREE OF INSTABILITY AHEAD OF THE FRONT IS EXPECTED TO BE TEMPERED BY MODEST LOW LEVEL MOISTURE /SURFACE DEW POINTS GENERALLY 55-60 F/ AND GENERALLY WEAK MID LEVEL LAPSE RATES WHICH WILL INHIBIT HEATING/DESTABILIZATION...WITH MAXIMUM MLCAPE OF 1000-1200 J/KG IN A RELATIVELY NARROW AXIS AHEAD OF THE FRONT. MODERATE WESTERLY WINDS ALOFT WITH 30-40 KT 500 MB FLOW OVER NEW ENGLAND AND NY WILL CONTRIBUTE TO SUFFICIENT SHEAR TO AID STORM ORGANIZATION. WEAKER WINDS ALOFT/VERTICAL SHEAR IS FORECAST SWWD ALONG THE FRONT INTO THE OH VALLEY. ISOLATED STRONG/SEVERE STORMS ARE POSSIBLE FROM LATER THIS MORNING THROUGH THE AFTERNOON WITH MORE INTENSE CELLS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH BY LATE THIS AFTERNOON OR EVENING AS THE FRONT GRADUALLY MOVES INTO A LESS FAVORABLE ENVIRONMENT. ...CENTRAL PLAINS/SRN HIGH PLAINS... LARGE SCALE ASCENT IN ADVANCE OF THE CENTRAL ROCKIES UPPER TROUGH COUPLED WITH LOW LEVEL WARM ADVECTION IS RESULTING IN WIDESPREAD CONVECTION FROM NERN CO INTO KS. THE EXTENSIVE CLOUD COVER AND PRECIPITATION IS EXPECTED TO INHIBIT DIURNAL HEATING TODAY AND LIMIT MLCAPE TO 500-1000 J/KG. GREATER HEATING IS EXPECTED TO OCCUR SWD ACROSS PARTS OF WRN TX AS MID/UPPER LEVEL DRYING OVERSPREADS THE SRN HIGH PLAINS FROM THE WEST. SURFACE DEW POINTS OF 55-60F AND TEMPERATURES WARMING GENERALLY INTO THE 80S WILL CREATE MLCAPE AROUND 1000 J/KG THIS AFTERNOON. VERTICAL WIND PROFILES ARE EXPECTED TO EXHIBIT STRONG DIRECTIONAL SHEAR AS 20 KT SLY/SELY LOW LEVEL WINDS VEER TO 25-30 KT WNWLY WINDS IN THE MID LEVELS...RESULTING IN 30-35 KT DEEP LAYER SHEAR ACROSS THE REGION. NEW CONVECTION MAY DEVELOP SWD ALONG THE DRYLINE THIS AFTERNOON...AS WELL AS OVER WRN KS IN THE WAKE OF CURRENT CONVECTION IN THAT AREA. ALTHOUGH INSTABILITY WILL GENERALLY BE WEAK...SUFFICIENT VERTICAL SHEAR SUGGESTS POTENTIAL FOR ISOLATED SEVERE STORMS TO DEVELOP...WITH ACTIVITY SPREADING SLOWLY EWD TOWARD CENTRAL KS AND POSSIBLY INTO WRN OK TONIGHT. ...NRN AZ/SRN UT... WIDELY SCATTERED STRONG THUNDERSTORMS ARE CONTINUING ACROSS NWRN AZ AND EXTREME SWRN UT IN ASSOCIATION WITH A VORTICITY MAX MOVING EWD ACROSS EXTREME SRN NV. CURRENT ACTIVITY IS LOCATED WITHIN AXIS OF HIGHER PRECIPITABLE WATER/INSTABILITY ACROSS NWRN AZ...WITH MOISTURE DECREASING EWD ACROSS NRN AZ BASED ON GPS WATER VAPOR SENSORS. HOWEVER...PERSISTENT LARGE SCALE ASCENT IS EXPECTED TO RESULT IN DEEP LAYER MOISTENING AHEAD OF THE VORTICITY MAX WITH CONTINUED POTENTIAL FOR ISOLATED STRONG/SEVERE STORMS TO DEVELOP EWD TOWARD THE FOUR CORNERS REGION THROUGH THIS EVENING. ..WEISS/GUYER.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 16:36:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 12:36:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091638 SWODY1 SPC AC 091636 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT SAT SEP 09 2006 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER OH VALLEY INTO NEW ENGLAND THIS AFTERNOON... A SURFACE COLD FRONT WILL MOVE SEWD ACROSS THE UPPER OH VALLEY/NY/NEW ENGLAND THIS AFTERNOON INTO EARLY TONIGHT...IN ASSOCIATION WITH A POSITIVE TILT MID LEVEL TROUGH FROM THE UPPER GREAT LAKES TO CENTRAL/SRN QUEBEC. MODIFIED MORNING SOUNDINGS YIELD ONLY MODEST WARM SECTOR INSTABILITY /MLCAPE VALUES NEAR 1000 J/KG/ WITH DAYTIME TEMPERATURES OF 75-80 F AND DEWPOINTS NEAR 60 F. ALSO...FORECAST WIND PROFILES AND LOCAL VWP OBSERVATIONS SUGGEST THAT FLOW IN THE LOWEST 2-3 KM IS UNLIKELY TO EXCEED 30 KT THIS AFTERNOON IN THE WARM SECTOR AND VERTICAL SHEAR WILL REMAIN MODEST AT BEST. DESPITE THE LIKELIHOOD OF SEVERAL THUNDERSTORM CLUSTERS INVOF THE COLD FRONT THIS AFTERNOON...THE OVERALL ENVIRONMENT ONLY APPEARS SUPPORTIVE OF A MARGINAL WIND/HAIL THREAT. ...TX PANHANDLE TO CENTRAL KS THIS AFTERNOON INTO EARLY TONIGHT... A COMPLEX MID LEVEL WAVE WITH MULTIPLE EMBEDDED SPEED MAXIMA IS MOVING SLOWLY EWD FROM THE CENTRAL/SRN HIGH PLAINS TOWARD NW OK/KS/NEB...WHILE AN MCV IS APPARENT OVER S CENTRAL NEB. WIDESPREAD CLOUDS/RAIN WILL LIKELY PERSIST TODAY FROM CENTRAL/NE KS INTO NEB IN ASSOCIATION WITH THE LOW-LEVEL WAA AND THE MCV. THOUGH INSTABILITY WILL LIKELY BE LIMITED ALONG THE DEVELOPING WARM FRONT ACROSS NRN KS...SUFFICIENT CLOUD BREAKS FROM THE S COULD RESULT IN AN ENVIRONMENT MARGINALLY SUPPORTIVE OF ROTATING STORMS. FARTHER SW...ISOLATED STORMS COULD FORM THIS AFTERNOON/EVENING ALONG THE REMNANT LEE TROUGH INTO THE TX PANHANDLE. HERE...DEEP LAYER VERTICAL SHEAR AND INSTABILITY MAY SUPPORT SOME THREAT FOR ISOLATED HAIL/WIND WITH THE STRONGER STORMS. ...AZ AREA TODAY... A COUPLE OF THUNDERSTORM CLUSTERS HAVE BEEN ONGOING THIS MORNING IN ASSOCIATION WITH A MID-UPPER LEVEL SPEED MAX MOVING OVER NW AZ. THE CONVECTION AND THE MID LEVEL WAVE BOTH APPEAR TO BE WEAKENING AS OF MID MORNING. HOWEVER...AN INFLUX OF RELATIVELY RICH LOW-LEVEL MOISTURE ACROSS CENTRAL/SRN AZ AND LOCAL STORM OUTFLOWS MAY ALLOW CONVECTION TO PERSIST NEAR THE RIM THIS AFTERNOON. ISOLATED HAIL AND STRONG WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..THOMPSON/GRAMS.. 09/09/2006  From swody1 at goshenarc.org Sat Sep 9 19:54:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 15:54:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091957 SWODY1 SPC AC 091955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SAT SEP 09 2006 VALID 092000Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS AHEAD OF A FRONT FROM WRN NEW ENGLAND SWWD INTO OH... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SWRN AZ... ...UPPER OH VALLEY INTO NEW ENGLAND THIS AFTERNOON... A SURFACE COLD FRONT WAS MOVING SEWD ACROSS THE AREA AND AT MID AFTERNOON EXTENDED FROM CENTRAL ME SWWD THROUGH WRN NY AND INTO THE EXTREME NRN PORTION OF THE OH VALLEY. SEVERAL BANDS OF THUNDERSTORMS HAD DEVELOPED ALONG OR AHEAD OF THE FRONT... INCLUDING A BAND FROM NWRN PA INTO NERN OH THAT WAS ENHANCED BY THE LAKE BREEZE. MLCAPES AHEAD OF THE FRONT RANGE FROM 1000-1500 J/KG...WITH EFFECTIVE SHEAR MOSTLY 25-30 KT DUE TO UNIDIRECTIONAL WLY WINDS. RELATIVELY COLD TEMPERATURES ALOFT MAY SUPPORT A MARGINAL HAIL THREAT...3/4 TO 1 INCH SIZE...UNTIL EARLY EVENING. EVEN THROUGH THE WINDS FROM THE TOP OF THE BOUNDARY LAYER TO 300 MB ARE GENERALLY IN THE 15 TO 30 MPH RANGE...A FEW STRONG/ISOLATED SEVERE WIND GUSTS ARE POSSIBLE WITH ANY N-S ORIENTED THUNDERSTORM LINES. ...TX PANHANDLE INTO CENTRAL KS... A COMPLEX MID LEVEL TROUGH STRETCHED FROM THE NRN/CENTRAL ROCKIES EWD INTO THE CENTRAL PLAINS. WV IMAGERY SUGGESTS A WEAK UPPER LOW EMBEDDED WITHIN THE TROUGH WAS LOCATED OVER SERN WY. A HIGH LEVEL SPEED MAX AND DRIER AIR ALOFT WAS ALSO EVIDENT PUNCHING EWD FROM CO INTO WRN KS AND IS LIKELY TO REDEVELOP THE UPPER LOW TO NEAR AN MCV LOCATED NEAR IML. AT THE SURFACE...A STATIONARY FRONT EXTENDED FROM NERN CO SEWD INTO E CENTRAL KS. SOUTH OF THIS FRONT...TEMPERATURES HAD WARMED INTO THE 70S AND 80S AND WAS RESULTING IN MLCAPES FROM 1000-1500 J/KG OVER KS. THE DEEP LAYER VERTICAL SHEAR AND INSTABILITY MAY SUPPORT A THREAT FOR ISOLATED HAIL/WIND WITH THE STRONGER STORMS THROUGH THE REMAINDER OF THE AFTERNOON HOURS. ...AZ/SRN UT... ONE CLUSTER OF THUNDERSTORMS MOVED EAST OF THE PHX EARLIER TODAY ...BUT MORE STORMS HAD DEVELOPED WEST OF PHX ON AN OLD OUTFLOW BOUNDARY. THESE STORMS WERE INGESTING AN AXIS OF HIGHER INSTABILITY LOCATED ACROSS THE GILA RIVER VALLEY. WIND PROFILES IN THIS REGION WERE STRONG ENOUGH FOR ORGANIZED TSTMS AND WITH TEMPERATURES WARMING TO NEAR 90...THESE STORMS WILL HAVE A HAIL THREAT AS THEY MOVE TOWARD PHX. OTHER SCATTERED THUNDERSTORMS HAVE ALSO DEVELOPED FROM NRN AZ INTO SRN UT AND ISOLATED HAIL/STRONG WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..IMY.. 09/09/2006  From swody1 at goshenarc.org Sun Sep 10 01:00:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 21:00:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100102 SWODY1 SPC AC 100100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 01:17:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 21:17:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100120 SWODY1 SPC AC 100118 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0818 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:32:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:32:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100235 SWODY1 SPC AC 100232 DAY 1 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0932 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:39:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:39:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100242 SWODY1 SPC AC 100240 DAY 1 CONVECTIVE OUTLOOK RESENT 3 NWS STORM PREDICTION CENTER NORMAN OK 0940 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 02:48:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 22:48:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100250 SWODY1 SPC AC 100249 DAY 1 CONVECTIVE OUTLOOK RESENT 4 NWS STORM PREDICTION CENTER NORMAN OK 0949 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 03:11:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 09 Sep 2006 23:11:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100314 SWODY1 SPC AC 100312 DAY 1 CONVECTIVE OUTLOOK RESENT 5 NWS STORM PREDICTION CENTER NORMAN OK 1012 PM CDT SAT SEP 09 2006 VALID 100100Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY TO NORTHEAST STATES... UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS ERN CANADA...WHILE THE ATTENDANT COLD FRONT MOVES OFF THE COAST OF THE NERN STATES THIS FORECAST PERIOD. WRN EXTENT OF THIS FRONT INTO THE NRN PART OF THE OH VALLEY /WRN PA TO CENTRAL IL/ SHOULD REMAIN QUASISTATIONARY. LOSS OF DAYTIME HEATING WILL CONTINUE TO STABILIZE THE BOUNDARY LAYER...REDUCING AVAILABLE SURFACE BASED INSTABILITY FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS EVENING. A FEW SEVERE STORMS REMAIN POSSIBLE FROM CENTRAL/NRN IL INTO CENTRAL IND WHERE MERGERS OF CONVECTIVE OUTFLOW BOUNDARIES INDUCE CONVECTIVE DEVELOPMENT. POCKETS OF MARGINAL INSTABILITY COMBINED WITH 30-35 KT OF EFFECTIVE BULK SHEAR MAY SUPPORT ISOLATED HAIL/STRONG WIND GUSTS. THIS THREAT WILL LIKELY DIMINISH AS THE BOUNDARY LAYER STABILIZES. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY INDICATED A PRIMARY SHORT WAVE TROUGH CENTERED OVER CENTRAL NEB AND EXTENDING SWWD INTO WRN KS...WHILE A SERIES OF WEAKER IMPULSES EXTENDED FROM WRN WY TO ERN CO. ASCENT AHEAD OF THESE FEATURES SHOULD CONTINUE TO SUPPORT THUNDERSTORM DEVELOPMENT INTO THE EVENING PRIMARILY ALONG A SURFACE BOUNDARY EXTENDING FROM THE TX PANHANDLE NNEWD INTO WRN KS AND UPSLOPE REGION OF ERN CO. THE AIR MASS ACROSS THIS REGION IS MOIST AND AT LEAST MARGINALLY UNSTABLE TO SUPPORT A FEW STRONG TO SEVERE MULTICELL STORMS. LOSS OF DAYTIME HEATING SHOULD LIMIT SURFACE BASED POTENTIAL TO THE NEXT 1-2 HOURS...WITH WARM ADVECTION INCREASING COVERAGE OF ELEVATED CONVECTION ACROSS NRN KS/SERN NEB ALONG NOSE OF LLJ TO THE EAST OF NEB/KS SHORT WAVE TROUGH. WEAK INSTABILITY SHOULD PRECLUDE SEVERE WEATHER THREAT OVERNIGHT. ...AZ... A COUPLE OF SHORT WAVE TROUGHS WERE MOVING EWD ACROSS THE FOUR CORNERS REGION AND ERN NV/UT. ASCENT AHEAD OF THESE FEATURES WILL LIKELY SUPPORT CONVECTION ACROSS THE CENTRAL ROCKIES...WHILE WEAKER ASCENT SWD INTO AZ SHOULD LIMIT THE DEVELOPMENT OF ADDITIONAL STRONGER STORMS THIS EVENING. DECREASING WLY MID LEVEL FLOW ACROSS AZ WILL ALSO RESULT IN LESS DEEP LAYER SHEAR FOR STORM ORGANIZATION. THESE FACTORS COMBINED WITH DECREASING INSTABILITY ARE EXPECTED TO DIMINISH THE SEVERE THREAT...WITH ANY ADDITIONAL STORMS YET THIS EVENING HAVING A LOW POTENTIAL FOR STRONG WIND GUSTS AND/OR HAIL. ..PETERS.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 05:52:52 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 01:52:52 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 100555 SWODY1 SPC AC 100553 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT SUN SEP 10 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX PANHANDLE/NWRN OK INTO A PART OF SWRN KS... ...SYNOPSIS... 00Z NAM/GFS ARE IN BETTER AGREEMENT THAN THE LAST FEW RUNS OF THESE MODELS WITH RESPECT TO TIMING/AMPLIFICATION...AND INDICATE A BROAD UPPER TROUGH MOVING SLOWLY EWD ACROSS THE CENTRAL U.S. TODAY. A SURFACE LOW ACCOMPANYING THIS SYSTEM SHOULD TRACK FROM NORTH CENTRAL KS AT 12Z THIS MORNING TO NRN MO BY 12Z MONDAY. MEANWHILE...SURFACE FRONTS ARE NOT WELL DEFINED IN THE MODELS. THE MEAN COLD FRONT POSITION SHOULD EXTEND FROM NERN KS SWWD THROUGH NWRN OK INTO THE TX PANHANDLE AT THE TIME OF PEAK HEATING. ...OK AND TX PANHANDLES/NWRN OK/PART OF SW KS... SLIGHTLY STRONGER WLY MID LEVEL FLOW /UP TO 25 KT/ AND RESULTANT EFFECTIVE BULK SHEAR VALUES AROUND 30 KT ARE EXPECTED ALONG THE SRN PERIPHERY OF THE UPPER TROUGH ACROSS THIS REGION OF THE SRN PLAINS THIS AFTERNOON. MODEST MID LEVEL LAPSE RATES AROUND 6.5 C/KM EXTENDING EWD ACROSS THE SLIGHT RISK AREA AND SURFACE DEWPOINTS IN THE LOWER 60S WILL LIKELY SUPPORT AN AXIS OF MODERATE INSTABILITY /MLCAPE 1000-1500 J/KG/ BY PEAK HEATING. THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON ALONG THE EXTENT OF THE COLD FRONT AND ANY OUTFLOW BOUNDARIES LEFT OVER FROM CURRENT ACTIVITY OVER THE CENTRAL/SRN PLAINS. GREATEST SEVERE THREAT IS EXPECTED ACROSS THE SLIGHT RISK AREA WHERE MODERATE INSTABILITY WILL BE COLOCATED WITH STRONGER EFFECTIVE BULK SHEAR VALUES. SEVERE THREAT SHOULD CONTINUE INTO THE EARLY EVENING PRIOR TO BOUNDARY LAYER STABILIZATION. ...ELSEWHERE ACROSS THE SRN PLAINS TO NRN MO... MID LEVEL LAPSE RATES ARE EXPECTED TO BE WEAKER WITH EWD EXTEND INTO THE PLAINS...RESULTING IN LESS AVAILABLE INSTABILITY ALONG THE COLD FRONT...ESPECIALLY FROM NERN KS INTO MO. DESPITE THE WEAKER INSTABILITY...MODELS SUGGEST EFFECTIVE SHEAR VALUES EXCEEDING 30 KT ACROSS NERN KS/NRN MO MAY SUPPORT A GREATER SEVERE THREAT ACROSS THESE AREAS THAN POINTS FARTHER S ACROSS KS. HOWEVER...MODEL UNCERTAINTIES AND LOW CONFIDENCE IN THE POSITION OF THE COLD FRONT AT PEAK HEATING HAVE LED TO THE ISSUANCE OF BROAD 5% SEVERE PROBABILITIES FOR HAIL AND WIND EXTENDING FROM THE TX S PLAINS ACROSS CENTRAL/ERN KS TO NRN MO. ..PETERS/GUYER.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 12:40:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 08:40:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101242 SWODY1 SPC AC 101240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0740 AM CDT SUN SEP 10 2006 VALID 101300Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF SRN HIGH PLAINS... ...SRN HIGH PLAINS TOWARDS THE MID MS RIVER VALLEY... SLOW MOVING SHORTWAVE TROUGH WILL CONTINUE MOVING ACROSS THE CENTRAL PLAINS TODAY. AT THE SURFACE...ASSOCIATED SURFACE COLD FRONT WILL CONTINUE SAGGING ESEWD ACROSS CENTRAL/ERN KS WITH TAIL END SHIFTING SWD BEFORE STALLING INTO W-CENTRAL TX/ERN NM THIS AFTERNOON. THIS SHOULD ALLOW PRIMARY SURFACE CONVERGENCE AXIS TO BECOME ESTABLISHED FROM PORTIONS OF THE CENTRAL TX PANHANDLE NEWD INTO NWRN OK LATER TODAY. 12Z SOUNDING FROM AMA INDICATED MID LEVEL LAPSE RATES REMAIN RATHER STEEP WITH 7.1 C/KM LR FROM H7 TO H5. AIR MASS SHOULD BECOME MODERATELY UNSTABLE AND WEAKLY CAPPED AS TEMPERATURES WARM TO NEAR 80F JUST AHEAD OF THE SURFACE FRONT. MID/UPPER LEVEL WLY WINDS ALONG PERIPHERY OF SLOW MOVING SHORTWAVE TROUGH SHOULD SUSTAIN SUFFICIENT CLOUD-LAYER SHEAR FOR ORGANIZED MULTICELLS/LINES WITH EXPECTED THUNDERSTORM DEVELOPMENT LATE TODAY AND THIS EVENING. ISOLATED DAMAGING WINDS AND MARGINALLY SEVERE HAIL WILL BE PRIMARY SEVERE HAZARDS WITH THIS ACTIVITY. SLY H85 FLOW AND ASSOCIATED LOW LEVEL WAA REGIME WILL REMAIN IN PLACE OVER ERN PORTIONS OF THE CENTRAL PLAINS EWD TOWARDS THE MID MS RIVER VALLEY TODAY. THIS SHOULD MAINTAIN THUNDERSTORMS ALONG THIS PORTION OF THE FRONT FOR MUCH OF THE PERIOD...AND LIMIT OVERALL HEATING/INSTABILITY. MODEST DEEP LAYER SHEAR AND MARGINAL INSTABILITY MAY SUPPORT AN ISOLATED STRONG TO MARGINALLY SEVERE THUNDERSTORM. ..EVANS/GUYER.. 09/10/2006  From swody1 at goshenarc.org Sun Sep 10 19:55:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 15:55:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 101957 SWODY1 SPC AC 101955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0255 PM CDT SUN SEP 10 2006 VALID 102000Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS W-CENTRAL/NW TX...ERN TX PANHANDLE...WRN OK... ...SYNOPSIS... HEIGHTS CONTINUE TO BUILD ACROSS W-CENTRAL/NWRN CONUS...AS DOWNSTREAM SHORTWAVE TROUGH NOW OVER ERN NEB...WRN IA...CENTRAL KS AND NWRN OK EJECTS SLOWLY EWD. ASSOCIATED/PRIMARY SFC LOW IS ANALYZED INVOF CENTRAL PORTION KS/NEB BORDER...AND IS EXPECTED TO MOVE OR REDEVELOP EWD TOWARD NRN MO THROUGH OVERNIGHT HOURS. TWO SFC COLD FRONTS ARE ANALYZED ATTM -- INITIAL FRONT EXTENDING SWWD FROM LOW OVER EXTREME ERN OK PANHANDLE...THEN SSWWD ACROSS ERN TX PANHANDLE...THEN SWWD TO SERN NM. SECOND/STRONGER COLD FRONTAL SURGE IS EVIDENT FROM LOW WSWWD ACROSS NWRN KS AND E-CENTRAL CO...AND SHOULD CATCH UP TO INITIAL FRONTAL ZONE ACROSS OK AND W TX NEAR END OF PERIOD OR EARLY DAY-2. ...SRN PLAINS... SHORT TERM SVR GUST/HAIL POTENTIAL IS DEVELOPING ALONG AND N OF OUTFLOW BOUNDARY WHERE INSOLATION AND SFC DEW POINTS MID-UPPER 60S HAVE BOOSTED MLCAPES TO AOA 2000 J/KG. PERSISTENT DEEP CU...TOWERING CU AND YOUNG CB HAVE BEEN SEEN ON VIS IMAGERY OVER MOTLEY/COTTLE COUNTIES TX INVOF FRONT/TROUGH/OUTFLOW BOUNDARY INTERSECTION...WHERE LOW LEVEL CONVERGENCE SHOULD BE MAXIMIZED. ACTIVITY DEVELOPING IN THIS AREA MAY SPREAD/MOVE SSEWD TOWARD BGS-ABI-MWL CORRIDOR LATER THIS AFTERNOON AND EVENING...PER SPC MESOSCALE DISCUSSION 1955. FURTHER CONVECTIVE DEVELOPMENT MAY OCCUR OVER ERN PANHANDLE AND MOVE SSEWD OR SEWD INTO DESTABILIZED OUTFLOW AIR ACROSS SERN PANHANDLE...AND PERHAPS EXTREME WRN OK. DESPITE WEAK ABSOLUTE SPEEDS IN LOW-MIDDLE LEVELS...VERTICAL SHEAR MAY BE FAVORABLE FOR AT LEAST MRGL SUPERCELL ORGANIZATION...AS WELL AS WELL-ORGANIZED MULTICELLULAR CHARACTERISTICS. RELATIVELY BACKED/ELY SFC FLOW COMPONENT WILL CONTINUE TO MAXIMIZE BOTH LOW LEVEL HODOGRAPHS AND DEEP-LAYER SHEAR ALONG AND N OF OUTFLOW BOUNDARY...WITH BOTH FDR VWP DATA AND MODIFIED RUC SOUNDINGS SHOWING 0-1 KM SRH 75-150 J/KG...AND 30-35 KT EFFECTIVE SHEAR. SVR THREAT SHOULD DIMINISH AFTER APPROXIMATELY 3-4Z...WHEN LOSS OF SFC HEATING AND INCREASING PREVALENCE OF OUTFLOW AIR SHOULD DIMINISH AVAILABLE BUOYANCY. ...E-CENTRAL PLAINS TO MID MS VALLEY... BAND OF MAXIMIZED LARGE SCALE ASCENT -- ASSOCIATED WITH MID-UPPER LEVEL SHORTWAVE TROUGH -- HAS HELPED TO MAINTAIN ENVIRONMENT FAVORABLE FOR TSTMS IN SWATH FROM SERN KS NNEWD ALONG I-35 IN NWRN MO. THIS ACTIVITY SHOULD CONTINUE TO SHIFT EWD THROUGH MO IN INCREASINGLY UNSTABLE AND WEAKLY CAPPED AIR MASS. SFC DEW POINTS HAVE MIXED INTO 50S/LOW 60S F OVER MUCH OF MO AND WRN IL AMIDST STRONG SFC HEATING...CONTRIBUTING TO FAVORABLE BOUNDARY LAYER PROFILES FOR ISOLATED STG-SVR GUSTS FROM MOST VIGOROUS CELLS. MEANWHILE...ADDITIONAL DESTABILIZATION -- SFC AND ALOFT -- IS POSSIBLE BEHIND AFOREMENTIONED CLOUD/PRECIP BAND ACROSS PORTIONS WRN/SRN KS...SWWD OVER NWRN OK. DEEP-LAYER WIND AND SHEAR PROFILES ARE FCST TO REMAIN WEAK...THOUGH LOW LEVEL HODOGRAPHS MAY BE ENLARGED E-SE OF SFC LOW AND INVOF WARM FRONT...ACROSS NERN KS AND NRN MO. ISOLATED LARGE HAIL...AND GUSTS APCHG SVR LIMITS...ARE POSSIBLE IN THESE AREAS...PRIMARILY BEFORE DARK. ..EDWARDS.. 09/10/2006  From swody1 at goshenarc.org Mon Sep 11 00:52:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 10 Sep 2006 20:52:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110054 SWODY1 SPC AC 110053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT SUN SEP 10 2006 VALID 110100Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NW TX/ERN TX PANHANDLE INTO WRN OK... ...SYNOPSIS... A BROAD MID/UPPER LEVEL TROUGH WILL MOVE SLOWLY EWD ACROSS THE CENTRAL U.S. THIS FORECAST PERIOD. WATER VAPOR IMAGERY INDICATED SEVERAL SMALLER SCALE SHORT WAVE TROUGHS EMBEDDED WITHIN THE BROADER TROUGH...WITH TWO OF THE MORE WELL-DEFINED FEATURES MOVING ACROSS IA AND THE LOWER MO RIVER VALLEY AT THIS TIME. MEANWHILE...SEVERAL WEAKER IMPULSES WERE LOCATED WITHIN THE WLY MID/UPPER LEVEL FLOW REGIME FROM THE CENTRAL/SRN ROCKIES EWD INTO THE CENTRAL/SRN PLAINS. PRIMARY SURFACE LOW WAS LOCATED OVER NERN KS EARLY THIS EVENING AND WILL TRACK ENEWD OVERNIGHT INTO NRN MO. TRAILING COLD FRONT WILL SPREAD ESE ACROSS KS/OK AND SHOULD EXTEND FROM NWRN MO SWWD THROUGH ERN KS AND CENTRAL OK TO THE TX S PLAINS BY 12Z MONDAY. A WARM FRONT EXTENDED ESEWD FROM THE SURFACE LOW ACROSS CENTRAL MO INTO THE LOWER OH VALLEY. ...PARTS OF NW TX/ERN TX PANHANDLE INTO WRN OK... ASCENT AHEAD OF WEAK MID LEVEL IMPULSES TRACKING EWD INTO THE SRN PLAINS THIS FORECAST PERIOD WILL SUPPORT ONGOING CLUSTER OF STORMS EXTENDING FROM WRN OK INTO PARTS OF NW TX. WSR-88D VWP AND AREA WIND PROFILERS INDICATED A BAND OF WLY MID LEVEL FLOW AT 25-30 KT EXTENDING FROM ERN NM INTO OK...WHICH IS RESULTING IN EFFECTIVE BULK SHEAR OF 25-35 KT. AIR MASS ACROSS THE ERN TX PANHANDLE/NW TX INTO WRN OK IN ADVANCE OF THE COLD FRONT SHOULD REMAIN MODERATELY UNSTABLE THROUGH 03Z...PRIOR TO MORE PRONOUNCED BOUNDARY LAYER STABILIZATION. THUS...THE CAPE/SHEAR VALUES SHOULD REMAIN SUPPORTIVE OF ORGANIZED STRONG TO SEVERE STORMS FOR THE NEXT FEW HOURS...WITH HAIL AND STRONG WINDS BEING THE PRIMARY THREATS. AFTER 03Z...DECREASING INSTABILITY SHOULD LIMIT THE EWD EXTENT OF THE SEVERE THREAT...BUT CONTINUED ASCENT ACROSS THE SRN PLAINS SHOULD SUPPORT A CONTINUED CONVECTIVE POTENTIAL ALONG/AHEAD OF THE COLD FRONT. ...EAST CENTRAL PLAINS INTO LOWER MO RIVER VALLEY... AN AREA OF MODERATE INSTABILITY EXTENDING NEWD ALONG AND EAST OF THE COLD FRONT AND SURFACE LOW SHOULD SUPPORT A FEW MORE HOURS /UNTIL 03Z/ OF SURFACE BASED THUNDERSTORM DEVELOPMENT. STRONGER EFFECTIVE BULK SHEAR VALUES WERE LOCATED PRIMARILY NORTH OF THE SURFACE LOW/WARM FRONT...AND THUS DISPLACE NWD OF THE AXIS OF GREATER INSTABILITY. EFFECTIVE BULK SHEAR AROUND 30 KT DID EXTEND INTO NERN KS AND MAY SUPPORT A FEW ADDITIONAL STRONG TO SEVERE STORMS ACROSS ERN KS...PRIOR TO THE ONSET OF BOUNDARY LAYER COOLING. OTHERWISE...ASCENT AHEAD OF THE SHORT WAVE TROUGH MOVING ACROSS MO SHOULD MAINTAIN A POTENTIAL FOR THUNDERSTORMS OVERNIGHT FROM IA/MO SWWD INTO ERN OK. ...CENTRAL/SRN HIGH PLAINS... ASCENT AHEAD OF A COUPLE OF MID LEVEL IMPULSES TRACKING EWD ACROSS THE CENTRAL/SRN ROCKIES COMBINED WITH UPSLOPE FLOW REGIME INTO THE HIGHER TERRAIN OF ERN CO TO NERN NM SHOULD SUPPORT A FEW ADDITIONAL STORMS DURING THE EARLY EVENING. MODEST WLY MID LEVEL FLOW AT 20-25 KT ATOP ENELY WINDS IN THE LOWEST 1 KM WILL MAINTAIN SUFFICIENT DEEP LAYER SHEAR FOR ROTATING STORMS. AXIS OF WEAK INSTABILITY EXTENDING FROM AROUND DEN SEWD INTO THE SRN HIGH PLAINS WILL SUPPORT A FEW STRONG TO SEVERE STORMS THROUGH ABOUT 03Z...PRIOR TO BOUNDARY LAYER STABILIZATION WITH LOSS OF DAYTIME HEATING. ISOLATED HAIL AND STRONG WIND GUSTS ARE EXPECTED TO BE THE PRIMARY THREATS. ..PETERS.. 09/11/2006  From swody1 at goshenarc.org Mon Sep 11 05:56:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 11 Sep 2006 01:56:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110558 SWODY1 SPC AC 110556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON SEP 11 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED BROAD MID/UPPER LEVEL TROUGH...CURRENTLY EXTENDING FROM THE UPPER MS VALLEY TO THE SRN HIGH PLAINS PER WATER VAPOR IMAGERY...WILL MOVE SLOWLY EWD ACROSS THE CENTRAL U.S. TODAY. MEANWHILE...A SHORT WAVE TROUGH...NOW MOVING SSEWD INTO ERN MT...WILL CONTINUE TO DIG SWD FROM THE NRN INTO CENTRAL HIGH PLAINS ALONG WRN PERIPHERY OF CENTRAL U.S. LARGE SCALE TROUGH. AT THE SURFACE...PRIMARY LOW OVER THE CENTRAL U.S. SHOULD BE LOCATED OVER NRN MO AT 12Z THIS MORNING...AND THEN MOVE NEWD REACHING SRN LAKE MICHIGAN REGION BY 12Z TUESDAY. TRAILING COLD FRONT WILL SPREAD E AND SE ACROSS THE MID MS VALLEY AND SRN PLAINS...AND SHOULD EXTEND FROM THE SURFACE LOW SSWWD THROUGH ERN AR TO SOUTH CENTRAL TX BY END OF THE PERIOD. ...N TX/PART OF LOWER MS VALLEY TO MID MS/LOWER OH VALLEYS... AT 12Z TODAY...AN AREA OF PRECIPITATION WITH EMBEDDED THUNDERSTORMS SHOULD BE ONGOING FROM PART OF THE OZARKS REGION NEWD TO THE MIDWEST. CLOUD COVER ASSOCIATED WITH THIS ACTIVITY MAY LIMIT SURFACE HEATING AND DESTABILIZATION ACROSS THE LOWER OH AND MID MS VALLEYS. AIR MASS IN ADVANCE OF THE COLD FRONT IS EXPECTED TO REMAIN MOIST...BUT WEAK LAPSE RATES AND/OR LIMITED SURFACE HEATING SHOULD RESULT IN GENERALLY MODEST INSTABILITY /MLCAPE AROUND 1000 J/KG/. ASCENT WITH ANY WEAK MID LEVEL IMPULSE MOVING ACROSS THIS REGION TODAY WILL PROVE FAVORABLE IN AIDING THUNDERSTORM DEVELOPMENT WITHIN A WEAKLY CAPPED AIR MASS. EFFECTIVE BULK SHEAR VALUES WILL BE MODEST /20-25 KT/...SUGGESTING MULTICELLS/CLUSTERS WILL BE POSSIBLE...BUT OVERALL WEAK FORCING AND INSTABILITY SHOULD LIMIT THE SEVERE THREAT. STORMS THAT CAN MAINTAIN UPDRAFT STRENGTH WILL HAVE THE POTENTIAL TO PRODUCE ISOLATED HAIL AND/OR STRONG WIND GUSTS. THREAT SHOULD DIMINISH THIS EVENING AS THE BOUNDARY STABILIZES WITH THE LOSS OF DAYTIME HEATING. ...ERN CO/ERN NM... DESPITE STEEP MID LEVEL LAPSE RATES EXPECTED FROM CO INTO NERN NM...LIMITED LOW LEVEL MOISTURE WITH NWD EXTENT ACROSS THIS REGION SHOULD RESULT IN MLCAPE VALUES AOB 500 J/KG. LARGE SCALE ASCENT AHEAD OF THE SWD MOVING SHORT WAVE TROUGH SHOULD PROVIDE SUFFICIENT DESTABILIZATION FOR AN ISOLATED HAIL/STRONG WIND GUST POTENTIAL ACROSS ERN CO. FARTHER S...UPSLOPE FLOW INTO PARTS OF ERN NM AND STRONG SURFACE HEATING SHOULD SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT. EFFECTIVE BULK SHEAR VALUES OVER THE CENTRAL/SRN HIGH PLAINS WILL BE SUFFICIENT FOR ORGANIZED STORMS...BUT WEAK INSTABILITY SHOULD LIMIT THE SEVERE COVERAGE. THUS...THE REASON FOR MAINTAINING LOW SEVERE HAIL/WIND PROBABILITIES. ..PETERS/GUYER.. 09/11/2006  From swody1 at goshenarc.org Wed Sep 13 00:44:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 12 Sep 2006 20:44:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130046 SWODY1 SPC AC 130044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0744 PM CDT TUE SEP 12 2006 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SRN GREAT LAKES REGION/LOWER OH VALLEY SWD INTO MS VALLEY... WATER VAPOR IMAGERY SHOWED A POSITIVELY TILTED MID/UPPER LEVEL TROUGH EXTENDING FROM THE WRN GREAT LAKES TO THE SRN HIGH PLAINS. THIS LARGE SCALE TROUGH WILL REMAIN PROGRESSIVE WITH AMPLIFICATION EXPECTED OVERNIGHT AS EMBEDDED SHORT WAVE TROUGH...NOW LOCATED OVER ERN IA...TRACKS SEWD INTO THE LOWER OH VALLEY. EARLY EVENING SURFACE ANALYSIS SHOWED AN AREA OF LOW PRESSURE JUST EAST OF ORD... WITH A COLD FRONT TRAILING SWWD TO NRN LA AND CENTRAL TX. SURFACE LOW WILL TRACK ENEWD REACHING LOWER GREAT LAKES REGION BY 12Z WEDNESDAY...WHILE THE FRONT MOVES SLOWLY EWD INTO OH/TN VALLEYS AND LOWER MS VALLEY. 45-50 KT WNWLY MID LEVEL JET OVER LOWER MO VALLEY WILL TRANSLATE ESEWD MAINTAINING STRONG DEEP LAYER SHEAR SUPPORTIVE OF ORGANIZED STORMS. HOWEVER...THE COMBINATION OF WEAK MID LEVEL LAPSE RATES AND DECREASING SURFACE BASED INSTABILITY ALONG AND AHEAD OF THE COLD FRONT ARE EXPECTED TO MINIMIZE ANY ADDITIONAL SEVERE THREAT FROM THE LOWER OH INTO LOWER MS VALLEYS. ...SWRN NM WWD TO LOWER CO RIVER VALLEY... UPPER LOW OVER FAR NRN BAJA REGION WILL MOVE SLOWLY EWD REACHING SOUTH CENTRAL AZ...ALONG THE MEXICAN BORDER BY 12Z WEDNESDAY. ASCENT DOWNSTREAM OF UPPER LOW CENTER COMBINED WITH A CONTINUED INFLUX OF LOW LEVEL MOISTURE INTO AZ/SWRN NM AND STEEP MID LEVEL LAPSE RATES SHOULD SUPPORT ADDITIONAL THUNDERSTORM DEVELOPMENT THIS FORECAST PERIOD. DEEP LAYER SHEAR IS SUPPORTIVE OF ORGANIZED STORMS PER LATEST WSR-88D VADS. HOWEVER...EXTENSIVE AREA OF CLOUDINESS ACROSS MUCH OF THIS REGION AND EVENTUAL LOSS OF DAYTIME HEATING WILL FURTHER LIMIT AVAILABLE CONVECTIVE INSTABILITY FOR ADDITIONAL STRONG TO SEVERE STORMS. THE EXCEPTION MAY BE ACROSS LOWER CO RIVER VALLEY WHERE STRONG SURFACE HEATING HAS RESULTED IN LARGE TEMPERATURE/DEWPOINT SPREADS EXCEEDING 50+ DEGREES...WITH DCAPE VALUES RANGING FROM 1300-1600 J/KG. CONVECTIVE OUTFLOW SPREADING WWD FROM STORMS NOW LOCATED IN WRN YAVAPAI COUNTY TO WRN PIMA COUNTY SHOULD HAVE THE GREATEST POTENTIAL TO PRODUCE A FEW STRONG WIND GUSTS...POTENTIALLY EXCEEDING SEVERE LEVELS INTO THIS EVENING...BEFORE THE BOUNDARY LAYER STABILIZES. ..PETERS.. 09/13/2006  From swody1 at goshenarc.org Wed Sep 13 05:55:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Sep 2006 01:55:04 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130556 SWODY1 SPC AC 130555 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT WED SEP 13 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...UPPER OH/TN VALLEYS SWD TO GULF COAST... UPPER TROUGH CENTERED OVER THE MID MS/LOWER OH VALLEYS AT 12Z WILL TRACK NORTHEAST TOWARD THE LOWER GREAT LAKES REGION THIS FORECAST PERIOD...WITH STRONGEST UPPER FORCING SPREADING ACROSS THE UPPER OH/ TN VALLEYS. ATTENDANT COLD FRONT WILL MOVE SLOWLY EWD TODAY THROUGH THE OH/TN VALLEYS AND NRN GULF COAST. A NARROW AXIS OF MOISTURE WILL EXTEND NWD IN ADVANCE OF THE COLD FRONT...WITH HIGHEST SURFACE DEWPOINTS EXPECTED TO BE CONFINED TO THE GULF COAST STATES. WEAK MID LEVEL LAPSE RATES AND EXTENSIVE CLOUD COVER ARE EXPECTED TO RESULT IN WEAK INSTABILITY...GENERALLY BELOW 1000 J/KG...MINIMIZING THE OVERALL SEVERE THREAT. IF SURFACE HEATING TAKES PLACE IN ADVANCE OF THE COLD FRONT...THEN POCKETS OF GREATER INSTABILITY WILL BE POSSIBLE. LOW LEVEL CONVERGENCE IS EXPECTED TO BE WEAK ALONG THE FRONT...BUT THE COMBINATION OF FRONTAL LIFT AND ASCENT AHEAD OF THE SHORT WAVE TROUGH SHOULD SUPPORT THUNDERSTORM DEVELOPMENT ALONG THE PROGRESSIVE...YET SLOW MOVING COLD FRONT. ALTHOUGH DEEP LAYER SHEAR WILL BE FAVORABLE FOR STORM ORGANIZATION...GENERALLY WEAK INSTABILITY WILL LIMIT DEVELOPMENT OF SEVERE STORMS. FARTHER S... WEAK UPPER FORCING SHOULD RESULT IN LESS STORM DEVELOPMENT...THOUGH AVAILABLE WEAK INSTABILITY AND 30-35 KT OF DEEP LAYER SHEAR MAY SUPPORT A FEW STRONG TO SEVERE STORMS ...AZ/SWRN NM... UPPER LOW LOCATED OVER NRN BAJA/SWRN AZ WILL MOVE EWD TODAY REACHING WRN NM BY 12Z THURSDAY. EXTENSIVE CLOUD COVER CURRENTLY LOCATED ACROSS MUCH OF AZ INTO SWRN NM MAY RESULT IN LIMITED SURFACE HEATING AND LACK OF GREATER DESTABILIZATION THIS FORECAST PERIOD. LARGE SCALE ASCENT AHEAD OF THE UPPER LOW COMBINED WITH STEEP MID LEVEL LAPSE RATES AND SUFFICIENT LOW LEVEL MOISTURE WILL ALLOW FOR THUNDERSTORMS ACROSS CENTRAL/SRN AZ INTO SWRN NM. HOWEVER...THE THREAT FOR SEVERE STORMS SHOULD BE MINIMAL...GIVEN THE POTENTIAL FOR WEAK INSTABILITY. ..PETERS/CROSBIE.. 09/13/2006  From swody1 at goshenarc.org Wed Sep 13 12:48:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 13 Sep 2006 08:48:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131250 SWODY1 SPC AC 131248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT WED SEP 13 2006 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL CONTINUE TO SLOWLY SHIFT EWD ACROSS THE APPALACHIANS THROUGH THE PERIOD. MODELS ARE CONSISTENT IN MOVING SURFACE LOW NOW OVER SRN MI/NRN OH EWD ACROSS THE ERN GREAT LAKES...WITH SECONDARY LOW CENTER CURRENTLY OVER SRN AL SPREADING EWD QUICKLY ACROSS THE SRN APPALACHIANS AND ALONG THE SC COAST BY THE END OF THE PERIOD. ...NERN GULF COAST TO THE COASTAL CAROLINAS... ACTIVE CLUSTER/LINE OF THUNDERSTORMS CONTINUES NEAR THE LOOP CURRENT OVER THE NERN GOM THIS MORNING...WHERE A COUPLE OF SUPERCELLS HAVE BEEN OBSERVED OFF THE FL BIG BEND COAST. MORNING SURFACE ANALYSES AND FORECAST SOUNDINGS ACROSS THIS REGION SUGGEST INSTABILITY WILL REMAIN QUITE MARGINAL INLAND TODAY WITHIN RELATIVELY WEAK DEEP LAYER SHEAR. HOWEVER...AREA VWPS AND OBSERVED HODOGRAPH AT TLH THIS MORNING INDICATE STRONG LOW LEVEL SHEAR WITH 0-1 SRH IN EXCESS OF 150 M2/S2. THE WEAK DEEP LAYER SHEAR /I.E. EFFECTIVE SHEAR AROUND 20 KT/ WILL LIMIT ANY SUSTAINED OR DEEP ROTATION. HOWEVER...GIVEN FEED OF RICH MOISTURE OFF THE GOM...AT LEAST LOW PROBABILITIES OF DAMAGING WINDS AND POSSIBLY A BRIEF TORNADO/WATERSPOUT ARE WARRANTED...ESPECIALLY NEAR THE NW-FL COAST TODAY. TONIGHT...WEAK CYCLOGENESIS ALONG THE FRONT IS FORECAST TO OCCUR INTO THE SC COASTAL PLAIN. WITH INCREASING SLY FLOW OFF THE ATLANTIC...LOW LEVELS SHOULD MOISTEN AND MAY ALLOW AIR MASS TO BECOME MARGINALLY UNSTABLE LATER TONIGHT. EFFECTIVE SHEAR AROUND 30 KT SHOULD SUPPORT SOME ORGANIZATION/LINES SHOULD MODEST INSTABILITY DEVELOP. WILL ADD LOW SEVERE PROBABILITIES INTO THIS REGION TO ACCOUNT FOR THIS. ...OH INTO THE CENTRAL APPALACHIANS... POCKET OF COLD MID LEVEL AIR /I.E. AOB -14C AT H5/ WILL OVERSPREAD THIS REGION THIS AFTERNOON...ASSOCIATED WITH WELL-DEFINED MID/UPPER LEVEL LOW NOW PROGRESSING EWD ACROSS IL/IND. THOUGH LOW LEVELS WILL BE RATHER COOL...STEEPENING MID LEVEL LAPSE RATES/COOLING ALOFT APPEAR SUFFICIENT FOR WEAK INSTABILITY THIS AFTERNOON NEAR THIS LOW CENTER. SCATTERED THUNDERSTORMS SHOULD DEVELOP...WITH THE POTENTIAL FOR HAIL WITH STRONGER STORMS THIS AFTERNOON. ...AZ... SLOW MOVING MID AND UPPER LOW WILL SHIFT ENEWD INTO THE SRN ROCKIES DURING THE PERIOD...WITH MID LEVEL DRYING LIKELY OVERSPREADING MUCH OF SRN AZ. ONGOING SHOWERS AND THUNDERSTORMS WILL LIKELY LIMIT INSTABILITY ACROSS MUCH OF THE REGION TODAY. HOWEVER...SUFFICIENT LOW LEVEL MOISTURE AND STRONGER HEATING IN CLOUD-FREE AREAS SHOULD SUPPORT MARGINAL TO MODERATE INSTABILITY THIS AFTERNOON. WHERE AIR MASS CAN DESTABILIZE...STORMS COULD PRODUCE MARGINALLY SEVERE HAIL. ..EVANS/CROSBIE.. 09/13/2006  From swody1 at goshenarc.org Tue Sep 19 00:52:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 18 Sep 2006 20:52:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190053 SWODY1 SPC AC 190052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 PM CDT MON SEP 18 2006 VALID 190100Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...WRN SC/GA... LATEST SFC ANALYSIS SHOWS A COLD FRONT POSITIONED FROM THE OH VALLEY SWWD INTO THE LOWER MS VALLEY. A PREFRONTAL TROUGH IS LOCATED ACROSS THE SRN APPALACHIANS EXTENDING SWD ACROSS ERN GA WITH A NEARLY CONTINUOUS CONVECTIVE LINE MOVING EWD ACROSS WRN GA. RUC ANALYSIS SHOWS A WEAKLY UNSTABLE AIRMASS AHEAD OF THE LINE WITH RELATIVELY LITTLE VERTICAL SHEAR SUGGESTING ANY SEVERE THREAT SHOULD REMAIN VERY MARGINAL THIS EVENING. A BRIEF WINDOW FOR STRONG GUSTY WINDS MAY EXIST WITH BOWING SEGMENTS FOR A FEW MORE HOURS. ..BROYLES.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 05:16:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 01:16:39 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190517 SWODY1 SPC AC 190516 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1216 AM CDT TUE SEP 19 2006 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...ERN SEABOARD/FL... A COLD FRONT OVER THE APPALACHIAN MTNS THIS MORNING WILL ADVANCE SEWD INTO THE ATLANTIC COASTAL PLAINS THIS AFTERNOON. THUNDERSTORMS WILL LIKELY BE ONGOING ALONG THE FRONT AND THUNDERSTORM COVERAGE SHOULD INCREASE BY AFTERNOON AS DESTABILIZATION OCCURS. NUMEROUS THUNDERSTORMS WILL ALSO LIKELY DEVELOP ALONG A PRE-FRONTAL TROUGH ACROSS NRN AND CNTRL FL. ALTHOUGH MODEL FORECASTS SHOW WEAK VERTICAL SHEAR IN PLACE...SFC DEWPOINTS IN THE MID 70S F SHOULD ALLOW POCKETS OF MODERATE INSTABILITY TO DEVELOP. THIS SHOULD BE ENOUGH FOR STRONG WIND GUSTS WITH THE BETTER ORGANIZED LINE SEGMENTS DURING THE LATE AFTERNOON. ..BROYLES/GRAMS.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 12:25:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 08:25:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191226 SWODY1 SPC AC 191224 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0724 AM CDT TUE SEP 19 2006 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EASTWARD ACROSS THE OH/TN VALLEYS AND TOWARD THE ATLANTIC COAST THIS FORECAST PERIOD. MEANWHILE...SURFACE COLD FRONT WILL PUSH EASTWARD INTO THE CAROLINAS AND SOUTHEAST STATES. AMPLE MOISTURE AND POCKETS OF DAYTIME HEATING WILL LIKELY RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF FRONT. HOWEVER...WEAK LAPSE RATES...WARM TEMPERATURES ALOFT...AND WEAK CONVERGENCE ALONG FRONT ARE EXPECTED TO MINIMIZE INTENSITY OF CONVECTION. ISOLATED STORMS MAY PRODUCE LOCALLY GUSTY WINDS FROM NC INTO FL THIS AFTERNOON...BUT ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED. ..HART/GRAMS.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 15:51:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 11:51:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191552 SWODY1 SPC AC 191551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1051 AM CDT TUE SEP 19 2006 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EASTWARD ACROSS THE OH/TN VALLEYS AND TOWARD THE ATLANTIC COAST THIS FORECAST PERIOD. MEANWHILE...SURFACE COLD FRONT WILL PUSH EASTWARD INTO THE CAROLINAS AND SOUTHEAST STATES. AMPLE MOISTURE AND POCKETS OF DAYTIME HEATING WILL LIKELY RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF FRONT. CLUSTER OF STORMS REMAINS SEMI-ORGANIZED ACROSS THE FL PANHANDLE INTO FAR SRN GA LATE THIS MORNING. HOWEVER...WEAK FLOW THROUGHOUT THE TROPOSPHERE AND WEAK LAPSE RATES/WARM TEMPERATURES ALOFT ARE EXPECTED TO MINIMIZE OVERALL SEVERITY OF THIS CONVECTION. ISOLATED STORMS MAY PRODUCE LOCALLY GUSTY WINDS FROM INTO NRN FL/SRN GA THIS AFTERNOON...AND POSSIBLY ALONG THE FRONT INTO THE COASTAL CAROLINAS...BUT ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED. ..EVANS/GUYER.. 09/19/2006  From swody1 at goshenarc.org Tue Sep 19 19:56:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 15:56:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191956 SWODY1 SPC AC 191954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0254 PM CDT TUE SEP 19 2006 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...SERN VA SWWD INTO NRN FL/THE FL PANHANDLE... VERY MOIST BOUNDARY LAYER BUT WEAK MID-LEVEL LAPSE RATES CHARACTERIZE THE THERMODYNAMIC ENVIRONMENT E OF THE APPALACHIANS...AHEAD OF EWD-MOVING COLD FRONT. SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP INVOF THIS BOUNDARY...WITH MOST VIGOROUS CONVECTION NOW OCCURRING FROM FAR SERN SC INTO N FL. ALONG WITH THE GENERALLY WEAK THERMODYNAMIC ENVIRONMENT...DEEP-LAYER WIND FIELD REMAINS MARGINAL FOR ORGANIZED/SEVERE STORMS...WITH ROUGHLY UNIDIRECTIONAL FLOW GENERALLY LESS THAN 30 KT THROUGH MID-LEVELS. THOUGH A FEW STRONGER STORMS MAY PRODUCE LOCALLY STRONG GUSTS THROUGH THE AFTERNOON...OVERALL SEVERE THREAT SHOULD REMAIN LOW UNTIL ENDING COMPLETELY AS FRONT MOVES OFF THE ATLANTIC COAST THROUGH THIS EVENING. ..GOSS.. 09/19/2006  From swody1 at goshenarc.org Wed Sep 20 00:49:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 19 Sep 2006 20:49:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200050 SWODY1 SPC AC 200048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT TUE SEP 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN INTERMOUNTAIN REGION... ENOUGH INSOLATION HAS OCCURRED IN RELATIVELY MOIST POST-FRONTAL AIR MASS FOR SCATTERED THUNDERSTORM ACTIVITY...BENEATH EASTERN FRINGE OF MID-LEVEL THERMAL TROUGH ACROSS PARTS OF EASTERN WASHINGTON/ OREGON INTO SOUTHWESTERN IDAHO. SOME HAIL IS POSSIBLE IN STRONGER CELLS...BUT ACTIVITY WILL PROBABLY QUICKLY WEAKEN AROUND SUNSET. WITH PRIMARY MID-LEVEL JET STREAK STILL DIGGING NEAR COASTAL AREAS OF SOUTHWEST OREGON...STRONGER FORCING IS FOCUSED IN THE BASE OF THE UPPER TROUGH. THIS WILL SPREAD ACROSS THE NORTHERN GREAT BASIN TONIGHT...AND MAY CONTRIBUTE TO ENOUGH DESTABILIZATION TO MAINTAIN AT LEAST SCATTERED THUNDERSTORM ACTIVITY AFTER DARK. CAPE IS GENERALLY WEAK...BUT THERMODYNAMIC PROFILES MAY STILL BE CONDUCIVE TO SMALL HAIL IN STRONGER ONGOING STORMS ACROSS NORTH CENTRAL/ NORTHEAST NEVADA INTO SOUTH CENTRAL IDAHO. PROFILES WITH LARGE LOW-LEVEL DEW POINT DEPRESSIONS MAY BE A BIT MORE FAVORABLE FOR LOCALIZED DOWNBURSTS...AND DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH A 50-70 KT 500 MB JET MAY MAINTAIN RISK FOR GUSTY WINDS EASTWARD INTO NORTHERN UTAH LATER TONIGHT. ...SOUTH ATLANTIC COAST STATES... PRE-FRONTAL LINE OF STORMS ACROSS EASTERN/SOUTHERN NORTH CAROLINA APPEARS TO BE AIDED BY A WEAK IMPULSE PROGRESSING OUT OF THE BASE OF A BROADER SCALE EASTERN U.S. TROUGH. ENOUGH EVAPORATIVE COOLING APPEARS POSSIBLE NEAR HEAVY RAIN CORES TO SUPPORT A LOCALIZED DAMAGING WIND THREAT...WITH ACTIVITY EMBEDDED WITHIN A MODERATE CYCLONIC FLOW FIELD. HOWEVER...THREAT HAS BEEN LIMITED BY WEAK LAPSE RATES...AND LIKELY IS DECREASING FURTHER WITH A GRADUAL LOSS OF DAYTIME HEATING. ...FLORIDA... BULK OF CONVECTIVE DEVELOPMENT...SUPPORTED BY ISENTROPIC ASCENT ASSOCIATED WITH STRONGER LOW-LEVEL WARM ADVECTION REGIME...NOW APPEARS EAST OF THE FLORIDA PENINSULA. BUT...PRE-FRONTAL FORCING WILL PROBABLY REMAIN SUFFICIENT TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS OFF THE SOUTHEASTERN GULF OF MEXICO INTO CENTRAL/ SOUTHERN PORTIONS OF THE PENINSULA INTO THE OVERNIGHT HOURS. ..KERR.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 05:37:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 01:37:57 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200538 SWODY1 SPC AC 200537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT WED SEP 20 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...NEB/KS/OK AND TX PANHANDLES... A PROGRESSIVE UPPER-LEVEL TROUGH EVIDENT ON WATER VAPOR IMAGERY OVER THE WRN U.S. WILL MOVE EWD AND CLOSE-OFF CROSSING THE ROCKIES TODAY. MOISTURE WILL RETURN NWD INTO THE HIGH PLAINS AHEAD OF THE APPROACHING SYSTEM BUT A CAPPING INVERSION SHOULD REMAIN IN PLACE ACROSS MOST OF THE REGION THROUGH THE AFTERNOON. THE EXCEPTION MAY BE OVER WEST TX WHERE A FEW STORMS MAY INITIATE DURING THE LATE AFTERNOON WHERE INSTABILITY AND SHEAR IS FORECAST TO BE SLIGHTLY GREATER. HOWEVER...MOST OF THE CONVECTIVE DEVELOPMENT SHOULD HOLD OFF UNTIL LARGE-SCALE ASCENT RAPIDLY INCREASES WHEN THE UPPER-LOW DRIFTS EWD AND BEGINS TO AFFECT THE HIGH PLAINS AND WEST TX IN THE 04Z TO 08Z TIMEFRAME. ALTHOUGH FORECAST SOUNDINGS SHOW STRONG ENOUGH VERTICAL SHEAR TONIGHT FOR ISOLATED SUPERCELLS...MOISTURE WILL NOT HAVE VERY LONG TO RETURN AHEAD OF THE APPROACHING SYSTEM. AS A RESULT...INSTABILITY SHOULD REMAIN RELATIVELY WEAK AS THE SYSTEM EJECTS INTO THE PLAINS TONIGHT. STEEP MID-LEVEL LAPSE RATES WILL EXIST AND ELEVATED INSTABILITY WILL BE PRESENT WHICH CONSIDERING THE STRONG ASCENT SHOULD BE FAVORABLE FOR MARGINALLY SEVERE HAIL STORMS. IF IT APPEARS LIKELY THAT INSTABILITY WILL BE GREAT ENOUGH FOR THE FORMATION OF SUPERCELLS OVER A LARGER AREA...AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...SRN AND CNTRL FL... A COLD FRONT OVER THE CNTRL FL PENINSULA THIS MORNING WILL MOVE SLOWLY SWD TODAY. A LINEAR MCS SHOULD BE ONGOING THIS MORNING ALONG THE BOUNDARY WITH THE LINE OF THUNDERSTORMS MOVING INTO SRN FL THIS AFTERNOON. FORECAST SOUNDINGS EARLY THIS AFTERNOON IN CNTRL AND SRN FL SHOW STEEP LOW-LEVEL LAPSE RATES AND RELATIVELY STRONG LOW-LEVEL WLY UNIDIRECTIONAL FLOW. THIS MAY BE ENOUGH FOR A FEW MARGINALLY SEVERE WIND GUSTS WITH THE STRONGER LINE SEGMENTS NEAR PEAK HEATING THIS AFTERNOON. ..BROYLES/GRAMS.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 12:42:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 08:42:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201243 SWODY1 SPC AC 201241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0741 AM CDT WED SEP 20 2006 VALID 201300Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE NORTHWARD INTO WESTERN KS... MORNING WATER VAPOR IMAGERY SHOWS POWERFUL UPPER TROUGH ROTATING ACROSS NV/UT. THIS FEATURE IS EXPECTED TO MOVE RAPIDLY EASTWARD ACROSS THE CENTRAL ROCKIES TODAY...AND INTO THE CENTRAL/SOUTHERN PLAINS TONIGHT. A VERY DYNAMIC PATTERN WILL DEVELOP ACROSS THE CENTRAL HIGH PLAINS FOR STRONG CONVECTION. THE MAIN FORECAST PROBLEM WILL BE THE QUALITY/TIMING OF LOW LEVEL MOISTURE RETURN. ...TX PANHANDLE... FULL SUNSHINE IS EXPECTED THIS AFTERNOON OVER THE TX PANHANDLE...WHERE WEAK SURFACE DRYLINE IS EXPECTED TO SLOWLY DEVELOP. WEAK LEAD IMPULSE CURRENTLY MOVING ACROSS NORTHERN AZ IS FORECAST TO APPROACH THIS REGION BY LATE AFTERNOON...PROVIDING SUFFICIENT FORCING FOR UPWARD VERTICAL MOTION FOR ISOLATED THUNDERSTORM DEVELOPMENT. SURFACE DEWPOINTS IN THE MID-UPPER 50S TO THE EAST OF THE DRYLINE...COUPLED WITH STEEP LOW/MID LEVEL LAPSE RATES SHOULD RESULT IN MLCAPE VALUES OF 500-1000 J/KG. DESPITE RELATIVELY WEAK CAPE VALUES...VERTICAL SHEAR PROFILES ARE EXPECTED TO BE QUITE FAVORABLE FOR ORGANIZED/SEVERE STORMS BY 00Z. LARGE HAIL AND GUSTY WINDS ARE EXPECTED IN STRONGEST CELLS OVER THIS REGION. ...WESTERN KS... EXIT REGION OF MID/UPPER JET WILL OVERSPREAD WESTERN KS AFTER 00Z...RESULTING IN RAPID/WIDESPREAD CONVECTIVE DEVELOPMENT. POTENTIAL FOR SEVERE STORMS IN THIS AREA IS MORE COMPLICATED DUE TO UNCERTAINTIES REGARDING MOISTURE RETURN. CURRENT INDICATIONS ARE THAT DEWPOINTS IN THE LOWER 50S WILL BE PRESENT...RESULTING IN CAPE VALUES BELOW 500 J/KG. HOWEVER...STRENGTH OF UPPER SYSTEM...STEEP MID LEVEL LAPSE RATES...AND VERY STRONG LOW LEVEL VERTICAL SHEAR SUGGEST THE THREAT OF INTENSE ELEVATED SEVERE STORMS OVERNIGHT. LARGE HAIL WILL BE POSSIBLE WITH INITIAL STORMS ACROSS WESTERN KS DURING THE LATE EVENING...BEFORE ACTIVITY BECOMES WIDESPREAD AND LESS INTENSE AFTER MIDNIGHT. ..HART/GRAMS.. 09/20/2006  From swody1 at goshenarc.org Wed Sep 20 20:05:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 16:05:46 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 202006 SWODY1 SPC AC 202005 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CDT WED SEP 20 2006 VALID 202000Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN KS SWD ACROSS THE TX/OK PANHANDLES... ...WRN KS INTO THE TX/OK PANHANDLES... MARGINAL BOUNDARY-LAYER MOISTURE IS RESULTING IN ONLY MINIMAL SURFACE-BASED INSTABILITY THIS AFTERNOON. THOUGH A FEW ISOLATED/SURFACE-BASED STORMS MAY DEVELOP LATE THIS AFTERNOON OVER THE HIGH PLAINS...MORE WIDESPREAD STORMS ARE EXPECTED OVERNIGHT AS WARM ADVECTION ASSOCIATED WITH INTENSIFYING LOW-LEVEL JET DEVELOPS ACROSS THE AREA. DEEP-LAYER SHEAR SUPPORTIVE OF ORGANIZED STORMS WOULD SUPPORT A THREAT FOR HAIL...AND RELATIVELY DEEP MIXED LAYER THIS AFTERNOON WOULD ALSO SUPPORT A BRIEF WINDOW OF POTENTIAL FOR LOCALLY-DAMAGING WINDS. OVERNIGHT...SHEAR SHOULD INCREASE...BUT COOLING BOUNDARY LAYER -- AND THUS ELEVATED NATURE OF CONVECTION -- SUGGESTS THAT MAIN OVERNIGHT THREAT WOULD BE IN THE FORM OF MARGINAL HAIL. ...THE FOUR CORNERS REGION... THUNDERSTORMS CONTINUE ACROSS THIS REGION THIS AFTERNOON...AHEAD OF DIGGING UPPER LOW. THOUGH LOW-LEVEL MOISTURE -- AND THUS INSTABILITY -- REMAINS MINIMAL...STRONG FLOW ALOFT MAY SUPPORT A FEW ORGANIZED/SUSTAINED UPDRAFTS. RELATIVELY DEEP MIXED LAYER MAY SUPPORT A FEW STRONG GUSTS WITH THE MORE ORGANIZED CELLS...WHILE COOLING TEMPERATURES ALOFT MAY ALSO SUPPORT MARGINAL HAIL. THREAT WILL DIMINISH THIS EVENING WITH THE ONSET OF DIURNAL COOLING. ..GOSS.. 09/20/2006  From swody1 at goshenarc.org Thu Sep 21 00:53:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 20 Sep 2006 20:53:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210054 SWODY1 SPC AC 210052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 PM CDT WED SEP 20 2006 VALID 210100Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF WRN KS...TX/OK PNHDL AND EXTREME NWRN OK... ...CNTRL PLAINS TO THE SRN HIGH PLAINS... WATER VAPOR IMAGERY INDICATES THAT THE UPPER LOW OVER THE GRT BASIN WAS BEGINNING TO MAKE A TURN TO THE EAST AND SHOULD MOVE TO SRN CO AND NRN NM BY 12Z. STRONGEST LARGE SCALE ASCENT ASSOCD WITH THIS SYSTEM WAS SPREADING EAST OF THE CONTINENTAL DIVIDE EARLY THIS EVENING AND WILL REACH THE SRN HIGH PLAINS AFTER 06-09Z. 00Z SOUNDINGS SUGGEST THAT MOISTENING HAS OCCURRED ON THE HIGH PLAINS...MAINLY IN THE H85-H7 LAYER...CONTRIBUTING TO MODEST DESTABILIZATION. THE MORE QUALITY MOISTURE...HOWEVER...REMAINS WELL S ACROSS DEEP S TX PER THE SATL DERIVED AND LAND BASED PWAT SENSORS. HIGH-BASED TSTMS HAVE BEEN OCCURRING ACROSS THE TX PNHDL/W TX PLAINS THIS EVENING AS THE UPPER SYSTEM BEGINS TO INTERACT WITH THE SUB-TROPICAL MOIST PLUME. STORMS MAY BECOME MORE NUMEROUS WITHIN THIS PLUME ACROSS PARTS OF OK OVERNIGHT. PRIMARY CONCERN FOR MORE ROBUST CONVECTION WILL OCCUR FROM THE TX PNHDL NWD INTO WRN KS OVERNIGHT AS THE STRONG ASCENT BEGINS TO OVERSPREAD THE INSTABILITY AXIS. TSTMS ARE EXPECTED TO FORM AFTER 06Z AND COULD BECOME SUFFICIENTLY ORGANIZED TO PRODUCE LARGE HAIL AND PERHAPS ISOLD DAMAGING WIND GUSTS. THESE STORMS WILL MOVE EWD INTO PARTS OF WRN KS AND NWRN OK BY DAYBREAK. OTHERWISE...AS THE SLY LLJ INCREASES OVERNIGHT ACROSS THE PLAINS...PROFILES WILL GRADUALLY MOISTEN AND DESTABILIZE ACROSS PORTIONS OF NRN KS AND NEB. 00Z LBF SOUNDING SHOWED A 7.8 DEG C PER KM LAPSE RATE AND SUFFICIENT CLOUD-BEARING SHEAR FOR ORGANIZED STORMS. THUS...ISOLD STRONGER CELLS WITHIN THE BANDS OF ELEVATED STORMS MAY PRODUCE LARGE HAIL. ..RACY.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 05:57:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 01:57:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210557 SWODY1 SPC AC 210556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT THU SEP 21 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS AND OZARKS... ...CNTRL-SRN PLAINS AND OZARKS... POTENT UPPER LOW CURRENTLY MOVING INTO THE SRN ROCKIES WILL SPIN EWD TO KS BY FRI AFTN...THEN DEAMPLIFY AS IT SWINGS NEWD INTO THE MO VLY BY 12Z SATURDAY. SFC LOW DEVELOPING OVER SERN CO WILL DEVELOP INTO KS ON FRI WITH A DRYLINE/FRONT SWEEPING EWD ACROSS ERN KS...CNTRL/ ERN OK AND CNTRL TX DURING THE AFTN/EVE. A WARM FRONT...MARKING THE LEADING EDGE OF MORE QUALITY BOUNDARY LAYER MOISTURE...WILL BEGIN TO LIFT NWD THROUGH ERN TX AND THE LWR MS VLY FRI AND FRI NIGHT. CONVECTION AND CLOUDS ASSOCD WITH A WARM CONVEYOR WILL BE ONGOING FROM N TX NWD INTO KS AND NEB AT THE START OF THE PERIOD. THIS CONVEYOR SHOULD SHIFT EWD INTO THE OZARKS BY AFTN...WITH POTENTIAL FOR CLEARING TO DEVELOP UPSTREAM AHEAD OF THE APPROACHING DRYLINE/ FRONT. MODIFIED GULF MOISTURE CHARACTERIZED BY SFC DEW POINTS IN THE 50S WILL ADVECT OR BE MAINTAINED ACROSS CNTRL AND ERN SECTIONS OF KS/OK THROUGH FRI AFTN. MORE ROBUST MOISTURE /DEW POINTS IN THE 60S TO LWR 70S/ WILL ARRIVE ACROSS NERN TX...SERN OK AND SWRN AR LATE FRI AFTN/EVE. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE APPROACHING SYSTEM /SWLY H5 JET 75+ KTS/ WILL TRANSLATE ACROSS KS/NRN OK WHERE INSTABILITY WILL BE TEMPERED BY MODEST MOISTURE. MAGNITUDE OF FORCING...HOWEVER...MAY COMPENSATE AND TSTMS WILL LIKELY INITIATE EARLY FRI AFTN FROM CNTRL KS SWD INTO CNTRL OK. VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS. THE STRONG FORCING WILL LIKELY RESULT IN SHORT LINE SEGMENTS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREAT AS THE STORMS MOVE INTO ERN KS AND NERN OK BY FRI EVE. THIS ACTIVITY WILL PROBABLY WEAKEN AS IT MOVES INTO MO...BUT STRONG LLJ AND STRONG MID-LEVEL FLOW MAY MAINTAIN AT LEAST AN ISOLD SEVERE THREAT OVERNIGHT INTO CNTRL/ERN MO. FARTHER S...00Z MODELS SUGGEST THAT THE SRN EXTENT OF AFTN TSTM DEVELOPMENT MAY GROW UPSCALE INTO A SMALL MCS FRI NIGHT FROM SERN OK AND NERN TX INTO AR. THIS REGION WILL BE ALONG SRN PERIPHERY OF STRONGER HEIGHT FALLS AND NRN EDGE OF RETURNING TROPICAL MOISTURE REGIME. FORECAST KINEMATIC PROFILES ARE QUITE SUPPORTIVE FOR SUPERCELLS AND ISOLD TORNADOES COULD OCCUR WITH THE MORE DISCRETE CELLS ACROSS SERN OK...EXTREME NERN TX AND PARTS OF SWRN AR. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. ..RACY/GRAMS.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 06:08:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 02:08:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210609 SWODY1 SPC AC 210608 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT THU SEP 21 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS AND OZARKS... CORRECTED FOR DAY OF WEEK ...CNTRL-SRN PLAINS AND OZARKS... POTENT UPPER LOW CURRENTLY MOVING INTO THE SRN ROCKIES WILL SPIN EWD TO KS BY THU AFTN...THEN DEAMPLIFY AS IT SWINGS NEWD INTO THE MO VLY BY 12Z FRIDAY. SFC LOW DEVELOPING OVER SERN CO WILL DEVELOP INTO KS ON THU WITH A DRYLINE/FRONT SWEEPING EWD ACROSS ERN KS...CNTRL/ERN OK AND CNTRL TX DURING THE AFTN/EVE. A WARM FRONT...MARKING THE LEADING EDGE OF MORE QUALITY BOUNDARY LAYER MOISTURE...WILL BEGIN TO LIFT NWD THROUGH ERN TX AND THE LWR MS VLY THU AND THU NIGHT. CONVECTION AND CLOUDS ASSOCD WITH A WARM CONVEYOR WILL BE ONGOING FROM N TX NWD INTO KS AND NEB AT THE START OF THE PERIOD. THIS CONVEYOR SHOULD SHIFT EWD INTO THE OZARKS BY AFTN...WITH POTENTIAL FOR CLEARING TO DEVELOP UPSTREAM AHEAD OF THE APPROACHING DRYLINE/ FRONT. MODIFIED GULF MOISTURE CHARACTERIZED BY SFC DEW POINTS IN THE 50S WILL ADVECT OR BE MAINTAINED ACROSS CNTRL AND ERN SECTIONS OF KS/OK THROUGH THU AFTN. MORE ROBUST MOISTURE /DEW POINTS IN THE 60S TO LWR 70S/ WILL ARRIVE ACROSS NERN TX...SERN OK AND SWRN AR LATE THU AFTN/EVE. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE APPROACHING SYSTEM /SWLY H5 JET 75+ KTS/ WILL TRANSLATE ACROSS KS/NRN OK WHERE INSTABILITY WILL BE TEMPERED BY MODEST MOISTURE. MAGNITUDE OF FORCING...HOWEVER...MAY COMPENSATE AND TSTMS WILL LIKELY INITIATE EARLY THU AFTN FROM CNTRL KS SWD INTO CNTRL OK. VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS. THE STRONG FORCING WILL LIKELY RESULT IN SHORT LINE SEGMENTS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREAT AS THE STORMS MOVE INTO ERN KS AND NERN OK BY THU EVE. THIS ACTIVITY WILL PROBABLY WEAKEN AS IT MOVES INTO MO...BUT STRONG LLJ AND STRONG MID-LEVEL FLOW MAY MAINTAIN AT LEAST AN ISOLD SEVERE THREAT OVERNIGHT INTO CNTRL/ERN MO. FARTHER S...00Z MODELS SUGGEST THAT THE SRN EXTENT OF AFTN TSTM DEVELOPMENT MAY GROW UPSCALE INTO A SMALL MCS THU NIGHT FROM SERN OK AND NERN TX INTO AR. THIS REGION WILL BE ALONG SRN PERIPHERY OF STRONGER HEIGHT FALLS AND NRN EDGE OF RETURNING TROPICAL MOISTURE REGIME. FORECAST KINEMATIC PROFILES ARE QUITE SUPPORTIVE FOR SUPERCELLS AND ISOLD TORNADOES COULD OCCUR WITH THE MORE DISCRETE CELLS ACROSS SERN OK...EXTREME NERN TX AND PARTS OF SWRN AR. OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. ..RACY.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 12:22:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 08:22:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211223 SWODY1 SPC AC 211222 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0722 AM CDT THU SEP 21 2006 VALID 211300Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF KS...OK...TX...MO...AND AR... ...CENTRAL KS/OK THIS AFTERNOON AND EVENING... IMPRESSIVE UPPER LOW OVER CO/NM WILL SURGE EASTWARD ACROSS THE CENTRAL PLAINS TODAY BEFORE WEAKENING AND LIFTING NORTHWARD LATE TONIGHT. STRONG FORCING FOR UPWARD VERTICAL MOTION HAS OVERSPREAD MUCH OF KS/OK AND NORTH TX THIS MORNING...WITH NUMEROUS SHOWERS/ THUNDERSTORMS WITHIN WARM CONVEYOR BELT. THIS ACTIVITY IS EXPECTED TO MOVE EASTWARD AND AWAY FROM KS/OK DRYLINE BY EARLY AFTERNOON. A COUPLE HOURS OF HEATING ALONG DRYLINE...COUPLED WITH NORTHWARD TRANSPORT OF MID/UPPER 50S SURFACE DEWPOINTS WILL RESULT IN A NARROW AXIS OF MODERATE INSTABILITY FROM SOUTH CENTRAL KS INTO CENTRAL OK. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL DEVELOP BY MID AFTERNOON AND MOVE EASTWARD INTO SOUTHEAST KS/EASTERN OK DURING THE EVENING. SUPERCELLS CAPABLE OF HAIL AND PERHAPS A TORNADO ARE POSSIBLE. VERTICAL SHEAR PROFILES AND FORCING ARE VERY FAVORABLE FOR ORGANIZED SEVERE STORMS. HOWEVER...NARROW INSTABILITY AXIS AND LIMITED LOW LEVEL MOISTURE ARE EXPECTED TO PRECLUDE A MORE SIGNIFICANT SEVERE WEATHER EVENT IN THIS AREA TODAY. ...EASTERN OK/WESTERN AR TONIGHT... MORNING SURFACE ANALYSIS SHOWS MAIN SURFACE WARM FRONT EXTENDING FROM SOUTH-CENTRAL TX INTO THE WESTERN GULF OF MEXICO. THIS BOUNDARY IS THE NORTHERN EXTENT OF TROPICAL MOISTURE /DEWPOINTS AOA 65F/. ALL MODEL GUIDANCE SUGGESTS THIS AIR MASS WILL RETURN RAPIDLY NORTHWARD TODAY...REACHING SOUTHEAST OK AND WESTERN AR AROUND/AFTER 00Z. THE STRONGEST FORCING ASSOCIATED WITH THE POWERFUL UPPER TROUGH WILL REMAIN NORTH OF THIS REGION. HOWEVER...IT CURRENTLY APPEARS LIKELY THAT CAPPING INVERSION WILL WEAKEN SUFFICIENTLY OVER THE ARKLATEX REGION AND SOUTHEAST OK FOR SCATTERED EVENING THUNDERSTORM DEVELOPMENT. VERY STRONG LOW LEVEL WARM ADVECTION WILL YIELD LOW LEVEL AND DEEP LAYER VERTICAL SHEAR PROFILES FAVORABLE FOR DISCRETE SUPERCELLS AND TORNADOES /3KM HELICITY OF 200-500 M2/S2 AND 6KM SHEAR OF 40-60 KNOTS/. THIS REGION WILL BE CLOSELY MONITORED THROUGH THE DAY WITH THE POTENTIAL FOR AN UPGRADE TO MODERATE RISK IF LOW LEVEL MOISTURE/INSTABILITY TRENDS APPEAR STRONGER THAN FORECAST. ..HART/GRAMS.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 16:40:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 12:40:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211641 SWODY1 SPC AC 211639 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1139 AM CDT THU SEP 21 2006 VALID 211630Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY TNGT ACROSS PARTS OF THE CENTRAL AND SRN PLAINS.... ...SYNOPSIS... VIGOROUS MID/UPR LEVEL LOW OVER THE OK/TX PANHANDLE THIS MORNING IS FORECAST TO MOVE NEWD INTO THE MIDDLE MO VALLEY DRAGGING A NEUTRALLY THEN NEGATIVELY TILTED TROF THRU THE SRN PLAINS INTO THE MID MS VALLEY. MEANWHILE...NEXT MID/UPR LEVEL TROUGH WILL DIVE SWD THRU THE NRN PLATEAU CARVING OUT A BROAD MID/UPR LVL TROUGH OVER THE CENTRAL U.S. BY THE END OF THE PERIOD. ...CENTRAL AND SRN PLAINS... SURFACE ANALYSIS THIS MORNING SHOWS 986 LOW OVER SERN CO WITH A COLD FRONT EXTENDING SWWD/WWD ACROSS NRN NM. PRONOUNCED SFC DRYLINE/TROUGH EXTENDS FROM W CENTRAL KS SWD ALONG THE WRN OK/TX PANHANDLE BORDER THEN WSWWD THRU EXTREME W TX. A WARM FRONT REACHES FROM NW AREAS OF TX SEWD THRU THE SERN TX GULF COAST. THE NAM/NAMKF AND HI RES WRF MODELS ARE CLOSE IN AGREEMENT TO HOW FAR LOW LEVEL MOISTURE WILL ADVECT NWD LATER THIS AFTN. BUT...THE GENERAL CONCENSUS BRINGS MID 60S TO 70 DEG DEWPOINTS INTO NERN PARTS OF NERN TX. MEANWHILE...AS MID/UPR LVL TROUGH MOVES EWD ACROSS THE CENTRAL/SRN PLAINS...THIS WILL PUSH THE DRYLINE EWD INTO S CENTRAL KS SWD THRU CENTRAL OK AND N CENTRAL TX BY 21Z. STRONG LOW/MID LVL DRY INTRUSION WILL PROVIDE SUFFICIENT FORCING FOR LINE OF STG/SVR TSTMS AS THERE WILL BE HEATING/DESTABILIZATION MOSTLY ACROSS CENTRAL TX INTO EXTREME S CENTRAL OK. AIR MASS JUST AHEAD OF THE DRYLINE IS FORECAST TO ACHIEVE 1000-2000 J/KG OF SBCAPE BETWEEN 21-00Z NWD TO THE ERN RED RIVER VALLEY OF OK/TX AS PER LATEST RUC FORECAST. FEEL THIS IS MORE REALISTIC THAN THE NAM WHICH TAKES THIS INSTABILITY NWD ALONG THE I35 CORRIDOR TO THE KS/OK BORDER. WOULD EXPECT THEN THAT 1500-2000 J/KG SBCAPE WILL MAKE IT INTO SERN OK BETWEEN 00-03Z PLACING GRADIENT OF INSTABILITY ALONG NERN TX/SERN OK REGION COUPLED WITH DEEP LAYER SHEAR OF 50-55 KT. THUS...EXPECT DISCRETE SUPERCELLS TO DEVELOP BETWEEN 21-03Z IN THE VICINITY OF THE RED RIVER VALLEY OF OK/TX E OF THE I35 CORRIDOR WHERE SUFFICIENT INSTABILITY AND ENHANCED STREAMWISE VORTICITY COULD SUPPORT A FEW TORNADOES. ADDED SIGNIFICANT TORNADO PROBABILITIES TO THE FORECAST AS ANALYSIS OF NAM/RUC MODEL SNDGS INDICATE LFC/LCL VALUES BETWEEN 1000/2000M AND 0-1KM SHEAR OF 30-35 KT. AS SQUALL LINE DEVELOPS ALONG/JUST E OF SFC DRYLINE...WOULD EXPECT MAIN THREATS ASSOCIATED WITH THIS TO BE HAIL AND DAMAGING WINDS. ..MCCARTHY/GUYER.. 09/21/2006  From swody1 at goshenarc.org Thu Sep 21 20:08:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 16:08:20 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212008 SWODY1 SPC AC 212006 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT THU SEP 21 2006 VALID 212000Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS SERN OK/NERN TX/SWRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN HALVES OF KS AND OK AND NERN TX EWD TO THE MS RIVER VALLEY... ...ERN KS/ERN OK/NERN TX EWD INTO THE MID MS VALLEY REGION... BOUNDARY LAYER MOISTURE CONTINUES STREAMING NWD ACROSS THE SRN PLAINS...AHEAD OF STRONG SURFACE LOW ANALYZED OVER WRN KS ATTM. THUNDERSTORMS HAVE DEVELOPED ACROSS N CENTRAL AND NWRN KS INVOF THE UPPER LOW...ALSO CENTERED OVER WRN KS. MEANWHILE WEAKLY-CAPPED BOUNDARY LAYER CONTINUES TO DESTABILIZE WITHIN NARROW WARM SECTOR AHEAD OF DRYLINE -- WHICH EXTENDS FROM S CENTRAL KS SSWWD INTO THE TX BIG BEND REGION...AND THE WARM FRONT -- WHICH EXTENDS FROM S CENTRAL KS SSEWD ACROSS CENTRAL OK INTO E TX. AS DRYLINE PROGRESSES EWD THIS AFTERNOON AND WARM FRONT SHIFTS EWD/NEWD ACROSS SERN KS AND ERN PORTIONS OF OK AND TX...STORMS SHOULD INITIATE WITHIN DESTABILIZING BOUNDARY LAYER -- PRIMARILY FROM NERN TX NWD ACROSS THE ERN HALF OF OK INTO SERN KS. BOUNDARY LAYER CAPPING SUGGESTS THAT INITIAL STORM DEVELOPMENT IS LIKELY TO BE ISOLATED/CELLULAR. GIVEN STRONG SELY BOUNDARY LAYER FLOW WHICH INCREASES/VEERS RAPIDLY WITH HEIGHT TO SWLY AT 50 TO 70 KT AT 3 KM ACCORDING TO AREA VWPS/PROFILERS...DEVELOPING STORMS SHOULD VERY RAPIDLY ACQUIRE ROTATION. WITH MID 60S DEWPOINTS NOW AS FAR N AS THE RED RIVER VALLEY OF N CENTRAL TX/S CENTRAL OK...LOW LCLS AND STRONG LOW-LEVEL SHEAR SUGGESTS A FAIRLY SIGNIFICANT TORNADO THREAT...SPREADING EWD ACROSS NERN TX AND SERN OK THIS EVENING. THOUGH BOUNDARY LAYER IS SLIGHTLY LESS MOIST/UNSTABLE NWD INTO ERN KS...FAVORABLE SHEAR IS STILL SUPPORTIVE OF ISOLATED TORNADOES ACROSS THIS REGION. OVERNIGHT...STORMS MAY BECOME MORE LINEAR...WITH SOME INCREASE IN POTENTIAL FOR DAMAGING WINDS ALONG WITH ONGOING HAIL/TORNADO THREAT. WIND THREAT SHOULD EXTEND AS FAR E AS THE WRN HALF OF AR AND SWRN MO...WITH HAIL THREAT ASSOCIATED WITH ELEVATED STORMS EXTENDING EWD TOWARD THE MS RIVER. ..GOSS.. 09/21/2006  From swody1 at goshenarc.org Fri Sep 22 00:48:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 21 Sep 2006 20:48:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220049 SWODY1 SPC AC 220048 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 PM CDT THU SEP 21 2006 VALID 220100Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF SERN OK...NERN TX AND SWRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL/SRN PLAINS INTO MO AND AR... ...ERN PORTION OF CENTRAL/SRN PLAINS... WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER LOW OVER NRN KS LIFTING NNEWD INTO NEB IN RESPONSE TO UPSTREAM VORTICITY MAX DIGGING SEWD ACROSS THE NRN INTERMOUNTAIN REGION. OCCLUDED SURFACE LOW NORTH OF CNK IS EXPECTED TO CONTINUE MOVING NEWD INTO ERN NEB TONIGHT. NRN PART OF SURFACE DRY LINE ARCING SWD FROM THE LOW ACROSS KS WILL MOVE INTO ERN KS...WHILE SRN PART OF DRYLINE ACROSS CENTRAL OK AND NORTH CENTRAL TX IS EXPECTED TO BECOME QUASI-STATIONARY AS STRONGEST DYNAMIC FORCING LIFTS NWD WITH TIME. A RELATIVELY NARROW WARM SECTOR HAS BECOME ESTABLISHED FROM CENTRAL/ERN TX NWD INTO ERN PARTS OF OK AND KS WITH SURFACE DEW POINTS IN THE LOW/MID 60S EXTENDING AS FAR NORTH AS NERN OK...DROPPING INTO THE 50S IN ERN KS. COLD AIR ALOFT AND STEEPER LAPSE RATES ARE LOCATED IN THE IMMEDIATE PROXIMITY OF THE NRN KS UPPER LOW...WITH PROGRESSIVELY WARMER MID LEVEL TEMPERATURES/WEAKER LAPSE RATES SWD INTO THE LOW LEVEL MOIST AXIS ACROSS ERN OK AND CENTRAL/ERN TX. THIS IS RESULTING IN MLCAPE OF AROUND 1000 J/KG OVER ERN PARTS OF OK AND TX. EARLIER TORNADIC THUNDERSTORMS OVER CENTRAL KS HAVE MOVED NWD AND WEAKENED...WHILE NEW STORMS ARE DEVELOPING FROM SERN KS ACROSS ERN OK. VAD AND PROFILERS EXHIBIT WINDS THAT VEER AND INCREASE IN SPEED WITH HEIGHT...RESULTING IN STRONG DEEP LAYER VERTICAL SHEAR OF 50-60 KT...AND SRH OF 200-400 MS/S2 IN THE LOWEST 1-3 KM AGL. THE WIND PROFILES ARE STRONGLY SUPPORTIVE OF SUPERCELL DEVELOPMENT FOR STORMS THAT CAN REMAIN DISCRETE...AND THE THREAT FOR TORNADOES WILL BE ENHANCED BY RELATIVELY LOW LCL HEIGHTS AND FAVORABLE SHEAR/SRH IN THE LOWEST 1 KM. MODEL GUIDANCE FROM RUC...NAM AND SREF AGREE WITH OBSERVATIONAL DATA SHOWING FOCUS ON THE SERN OK/NERN TX/SWRN AR REGION FOR AN INCREASED SEVERE POTENTIAL THROUGH THE EVENING HOURS AND THE HIGHEST SEVERE PROBABILITIES/MODERATE RISK REGION WILL BE MAINTAINED OVER THIS AREA. STORMS ARE LIKELY TO SPREAD NEWD INTO MO AND AR DURING THE OVERNIGHT HOURS...CONSOLIDATING INTO ONE OF MORE MCS/S ARE THEY MOVE INTO A REGION OF INCREASINGLY ELEVATED INSTABILITY. ALTHOUGH THREAT FOR TORNADOES AND DAMAGING WIND GUSTS IS EXPECTED TO DIMINISH LATER TONIGHT...POTENTIAL FOR ISOLATED LARGE HAIL WILL LIKELY CONTINUE THROUGH THE NIGHT ACROSS MO AND PARTS OF CENTRAL/ERN AR. ..WEISS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 05:48:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 01:48:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220549 SWODY1 SPC AC 220548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1248 AM CDT FRI SEP 22 2006 VALID 221200Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER AR...SRN/ERN MO...AND CENTRAL/SRN IL... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK OVER THE MIDDLE MS AND LOWER OH VALLEYS SWWD INTO NERN TX... ...SYNOPSIS... HIGH AMPLITUDE ENERGETIC FLOW PATTERN IS FORECAST TO CONTINUE THROUGH THE PERIOD AS CENTRAL PLAINS OCCLUDED UPPER LOW LIFTS NWD TOWARD SD AND BEGINS TO WEAKEN...AS UPSTREAM SHORT WAVE TROUGH OVER THE NRN INTERMOUNTAIN REGION DIGS SEWD INTO THE GREAT BASIN. THIS WILL RESULT IN A STRONG MID/UPPER LEVEL JET STREAM BECOMING ESTABLISHED FROM THE NRN PARTS OF AZ/NM ACROSS KS/OK AND THE MIDDLE MS VALLEY TODAY. AT THE SURFACE...COMPLEX PATTERN IS FORECAST TO EVOLVE AS OCCLUDED LOW LIFTS NWD TOWARD ERN SD/SWRN MN...WITH A COLD FRONT ARCING SWD FROM THE LOW INTO THE LOWER MO RIVER VALLEY THEN SWWD INTO THE SRN HIGH PLAINS. THE COLD FRONT IS FORECAST TO MOVE SEWD ACROSS THE SRN PLAINS REGION DURING THE NIGHT. IN ADVANCE OF THE COLD FRONT...A DRY LINE IS EXPECTED TO BE LOCATED FROM ERN KS/WRN MO SWD ACROSS ERN OK INTO CENTRAL TX. ...IL/MO/AR AREA... ...SIGNFICANT SEVERE THREAT EXPECTED TODAY... STRONG NOCTURNAL CONVECTION OVER PARTS OF MO AND AR IS EXPECTED TO MOVE EWD/NEWD DURING THE EARLY MORNING HOURS AND POSSIBLY CONTINUE INTO THE MS VALLEY PRIOR TO 18Z. THE MORNING ACTIVITY IN THE MIDDLE MS VALLEY WILL LIKELY REMAIN BELOW SEVERE LEVELS AS MOISTURE AND INSTABILITY WILL BE MARGINAL...ALTHOUGH THE STORMS MOVING INTO THE MID SOUTH REGION MAY HAVE POTENTIAL TO PRODUCE MARGINALLY SEVERE HAIL. LOW LEVEL MOISTURE IS EXPECTED TO INCREASE NWD IN THE WAKE OF THE MORNING CONVECTION. SURFACE DEW POINTS OF 65-70F ARE CURRENTLY OVER ERN OK INTO SRN/ERN TX AND LA AND MODEL GUIDANCE INDICATES THAT MOISTURE WILL SURGE NWD TOWARD THE MIDDLE MS VALLEY DURING THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH RESIDUAL CLOUDS AND OCCASIONAL CONVECTION WILL INHIBIT DIURNAL HEATING ACROSS PARTS OF THIS REGION...STRONGER HEATING IS LIKELY WHERE BREAKS IN THE CLOUD COVER DEVELOP...AND ALONG THE WRN PORTIONS OF THE LOW LEVEL MOIST AXIS FROM ERN OK/WRN AR INTO WRN MO/IA. THIS WILL ENHANCE DESTABILIZATION WITH MLCAPE RANGING FROM 1500-2000 J/KG OVER AR INTO SRN MO TO AROUND 1000 J/KG FROM NRN MO INTO CENTRAL IL. MULTIPLE BANDS OF CONVECTION ARE EXPECTED TO DEVELOP DURING THE AFTERNOON FROM PARTS OF ERN OK/WRN OK NNEWD INTO MO AND IL WITHIN A WEAKLY CAPPED ENVIRONMENT. MODEL FORECAST SOUNDINGS INDICATE WINDS WILL VEER AND STRENGTHEN WITH HEIGHT AS 40-50 KT SSWLY LOW LEVEL FLOW VEERS TO WLY/SWLY AT 50-75 KT ACROSS AN EXPANSIVE WARM SECTOR. THIS RESULTS IN VERY STRONG DEEP LAYER SHEAR /50-60 KT IN THE LOWEST 6 KM/ INDICATING A LIKELIHOOD FOR PERSISTENT SUPERCELLS TO DEVELOP. LOW LEVEL SHEAR WILL ALSO BE VERY STRONG WITH 0-1 KM SRH OF 200-400 M2/S2. GIVEN THE ANTICIPATED LOW LCL HEIGHTS AND POTENTIAL FOR DEVELOPMENT OF DISCRETE STORMS AND EMBEDDED SUPERCELLS WITHIN SHORT LINE SEGMENTS...THERE IS A THREAT FOR A FEW STRONG TORNADOES TO DEVELOP...IN ADDITION TO DAMAGING WIND GUSTS AND LARGE HAIL. THIS ACTIVITY WILL SPREAD NEWD THROUGH THE EVENING HOURS ACROSS THE MIDDLE MS VALLEY INTO THE LOWER OH VALLEY. ..WEISS/GRAMS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 12:47:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 08:47:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221248 SWODY1 SPC AC 221246 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 AM CDT FRI SEP 22 2006 VALID 221300Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK AND MUCH OF AR INTO PARTS OF MO AND IL... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM N TX INTO THE OH VLY... ...SYNOPSIS... UNSEASONABLY STRONG CLOSED LOW NOW NEARING FSD EXPECTED TO DRIFT N OR NNW THROUGH THE PERIOD AS UPSTREAM DISTURBANCE IN BROAD CYCLONIC FLOW MOVES FROM NRN UT TO ERN CO TODAY...AND THEN TURNS E/NE INTO KS/NEB TONIGHT/EARLY SATURDAY. THIS PATTERN WILL MAINTAIN AND LATER STRENGTHEN BELT OF FAST WSW FLOW IN PLACE ACROSS THE CENTRAL U.S. AT LOWER LEVELS...SURFACE LOW IN NW IA SHOULD LIFT SLOWLY N AND FURTHER OCCLUDE. ASSOCIATED COLD FRONT WILL CONTINUE SE ACROSS KS TODAY AND INTO NRN/WRN OK EARLY SATURDAY. DIFFUSE WARM FRONT NOW EXTENDING SE ACROSS IA INTO WRN KY SHOULD REDEVELOP N AS NOCTURNAL BOUNDARY LAYER MIXES OUT AND ELEVATED WARM/MOIST LAYER MIXES DOWNWARD. COMPLICATING THE PICTURE WILL BE PRESENCE OF OUTFLOW LEFT BY OVERNIGHT STORMS IN THE LWR MS VLY/OZARKS. LOW LEVEL DESTABILIZATION EXPECTED TO SPREAD MOST RAPIDLY NEWD ALONG WRN SIDE THE OUTFLOW INTO CNTRL/SRN MO AND WRN IL. FARTHER W...DRY LINE NOW EXTENDING FROM CNTRL MO THROUGH NE OK TO CNTRL TX MAY MIX SLIGHTLY E TODAY BEFORE BECOMING STATIONARY AND RETROGRESSING WWD TONIGHT AS UT/CO IMPULSE CONTINUES E...AND ASSOCIATED SURFACE WAVE STRENGTHENS OVER THE TX PANHANDLE. ...ERN OK/OZARKS INTO MID MS VLY... ...SIGNIFICANT SEVERE THREAT EXPECTED TODAY THROUGH EARLY SATURDAY... PERSISTENT AREA OF OVERNIGHT STORMS LIKELY WILL DELAY LOW LEVEL DESTABILIZATION OVER PARTS OF THE LWR TN...LWR OH AND MID MS VLYS TODAY AS ASSOCIATED VORT LOBE NOW ROUNDING SE QUADRANT OF SD UPR LOW CONTINUES NEWD. REGIONAL VWP/PROFILER DATA...AND SATELLITE/GPS MOISTURE DATA NEVERTHELESS INDICATE THAT SUBSTANTIAL MOISTENING HAS OCCURRED OVERNIGHT IN THE 925-850 MB LAYER OVER AR/WRN TN AND PARTS OF MO IN RESPONSE TO PERSISTENT 40+ KT SWLY LLJ. THIS MOISTURE LIKELY WILL CONTINUE TO SPREAD NEWD THROUGH THE PERIOD...AND SHOULD MIX TO THE SURFACE BY THIS AFTERNOON ACROSS THE SE HALF OF MO AND CNTRL/SRN IL. BY TONIGHT AND EARLY SATURDAY...EXPECT THAT LOW LEVEL MOISTURE WILL ALSO SPREAD NE INTO ERN OK AS NEW LLJ DEVELOPS DOWNSTREAM FROM APPROACHING UT/CO DISTURBANCE. COMBINATION OF MODERATE TO STRONG HEATING ON WRN/SRN EDGE OF CONVECTIVE OUTFLOW/DEBRIS...AND CONVERGENCE ALONG ASSOCIATED OUTFLOW BOUNDARIES/DRY LINE...LIKELY TO RESULT IN SUFFICIENT DESTABILIZATION/LIFT TO SUPPORT STORM DEVELOPMENT IN WEAKLY CAPPED ENVIRONMENT BY EARLY TO MID AFTERNOON FROM ERN OK/WRN AR NEWD INTO MO/IL. WHILE SOME MID LEVEL WARMING MAY OCCUR IN WAKE OF AFOREMENTIONED VORT LOBE...MLCAPE SHOULD REACH 1500-2000 J/KG OVER AR AND SRN MO...AND 1000 TO PERHAPS 1500 J/KG ACROSS THE REMAINDER OF MO INTO CENTRAL IL. OVERALL SETUP WITH INCREASINGLY BROAD...MOIST...AND WEAKLY CONVERGENT WARM SECTOR SURMOUNTED BY STRONG SWLY MID LEVEL FLOW SUGGESTS PROBABLE DEVELOPMENT OF MULTIPLE BANDS OF STORMS. LONG HODOGRAPHS WITH SUBSTANTIAL LOW LEVEL VEERING /40+ KT SSWLY LOW LEVEL JET BENEATH 50-70 KT WSWLY MID LEVEL FLOW/ SHOULD SUPPORT SCATTERED PERSISTENT SUPERCELLS WITH STRONG LOW LEVEL ROTATION. COUPLED WITH LOW LCL HEIGHTS AND BETTER THAN AVERAGE LIKELIHOOD FOR DISCRETE STORMS AND/OR EMBEDDED SUPERCELLS WITHIN SHORT LINE SEGMENTS...A THREAT WILL EXIST FOR A FEW STRONG AND POSSIBLY LONG-TRACKED TORNADOES. OTHER ACTIVITY MAY YIELD LOCALLY DAMAGING WIND AND...MAINLY IN THE WRN HALF OF THE MODERATE RISK AREA...SEVERE HAIL. THE STORMS SHOULD SPREAD NE THROUGH THE EVENING ACROSS THE MID MS AND LWR OH VLYS. OTHER SEVERE STORMS MAY FORM LATER TONIGHT THROUGH EARLY SATURDAY INVOF RETROGRESSING DRY LINE AND ACCELERATING COLD FRONT IN SE KS/ERN OK AND PERHAPS N TX. THESE STORMS MAY REMAIN SEVERE AS THEY MOVE/DEVELOP NE INTO PARTS OF MO AND WRN AR SATURDAY MORNING. ..CORFIDI/GRAMS.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 15:53:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 11:53:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221553 SWODY1 SPC AC 221552 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1052 AM CDT FRI SEP 22 2006 VALID 221630Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK AND MUCH OF AR INTO PARTS OF MO/IL AND FAR WRN KY/TN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM N TX INTO THE OH RIVER VALLEY... RATHER COMPLEX FORECAST TODAY AS SPECIFIC TIMING FOR GREATEST SEVERE THREAT STILL UNCERTAIN. EXTREME SHEAR WILL REMAIN IN PLACE OVER A LARGE PART OF THE CENTRAL U.S...WITH MOST FOCUSED INTENSE SHEAR REMAINING FROM THE ARKLATEX REGION NEWD ACROSS THE MID MS/LOWER OH RIVER VALLEYS. THIS INTENSE SHEAR WILL OVERSPREAD A VERY MOIST BOUNDARY LAYER AS 65+F SURFACE DEW POINTS ADVECT NNEWD INTO CENTRAL/NRN IL. OVERALL SETUP REMAINS QUITE FAVORABLE FOR AN OUTBREAK OF SEVERE THUNDERSTORMS AND TORNADOES ACROSS A LARGE PART OF THE CENTRAL U.S. ...THROUGH 20Z... OUTFLOW BOUNDARY/EFFECTIVE TROPICAL WARM FRONT REMAINS FAIRLY WELL DEFINED AT 15Z FROM WRN TN WSWWD INTO SERN-E-CENTRAL OK...AND MORNING SOUNDINGS WITHIN MOIST WARM SECTOR INDICATE LITTLE OR NO CAPPING WITH TEMPERATURES IN THE LOWER 80S. VWPS AND SHEAR ANALYSES INDICATE VERY FAVORABLE LOW AND DEEP LAYER SHEAR FOR TORNADIC SUPERCELLS...THOUGH OVERALL FOCUS FOR DEEP ASCENT APPEARS DIFFUSE FOR MUCH OF THE DAY . HOWEVER WITH INTENSE LOW PERSISTING OVER THE MID MO/SWRN MN...SWLY LLJ WILL REMAIN IN PLACE INTO THE MID SOUTH /H85 WINDS AROUND 40-45 KT/. THUS...ISOLATED TORNADIC SUPERCELLS MAY EVOLVE THROUGH THE DAY OVER AR INTO THE LOWER OH RIVER VALLEY. ACTIVITY WILL MOST LIKELY KEEP DEVELOPING WITHIN WARM AIR ALONG EDGE OF STEEPER LAPSE RATES OVER ERN OK...WRN/CENTRAL AR AND MOVE QUICKLY ENEWD INTO THE MID SOUTH. NEWD EXTENT OF THREAT FROM AFTERNOON ACTIVITY WILL BE HINDERED BY PERSISTENT CONVECTION/CLOUDS NOW OVERSPREADING SERN MO AND THE LOWER OH RIVER VALLEY. ...LATER TODAY AND OVERNIGHT... MORE VIGOROUS DEVELOPMENT CAN BE EXPECTED DURING THE MID TO LATE AFTERNOON FROM PORTIONS OF NERN TX/NWRN LA/ERN OK INTO THE MID MS RIVER VALLEY ALONG STRENGTHENING LOW LEVEL CONVERGENCE NEAR INTENSIFYING SURFACE TROUGH/FRONT. MODEL FORECASTS CONTINUE TO DEVELOP AXIS OF MODERATE INSTABILITY WITHIN VERY MOIST BOUNDARY LAYER INTO CENTRAL MO. IN ADDITION...SWLY LLJ WILL INCREASE LATE TODAY AND THIS EVENING AS UPSTREAM IMPULSE DIGS SEWD INTO THE CENTRAL ROCKIES AND LOW LEVEL TROUGH BECOMES BETTER DEFINED. THIS SHOULD MAINTAIN A THREAT OF STRONG TORNADOES AS SUPERCELLS AND SMALL BOW ECHOES EVOLVE AND RACE ENEWD INTO/ACROSS THE MID MS RIVER VALLEY LATER TODAY/OVERNIGHT SEVERE THREAT MAY OCCUR IN SEVERAL BANDS ACROSS WARM SECTOR GIVEN THE VERY WEAK INHIBITION...WITH DEVELOPMENT CONTINUING/BACK-BUILDING TO THE WEST AHEAD OF EWD MOVING NE-SW ORIENTED SURFACE TROUGH/FRONT. ..EVANS/CROSBIE.. 09/22/2006  From swody1 at goshenarc.org Fri Sep 22 19:57:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 15:57:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221958 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT FRI SEP 22 2006 VALID 222000Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS THE SERN 2/3 OF MO...ERN OK/THE NRN 2/3 OF AR...WRN TN...WRN KY...AND THE SRN 2/3 OF IL... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN TX EWD INTO THE TN VALLEY...AND NWD TO THE SRN UPPER GREAT LAKES REGION... ...NERN TX/ERN OK ACROSS THE MID MS/TN/LOWER OH VALLEYS... BOUNDARY LAYER MOISTURE CONTINUES STREAMING NWD ACROSS THE MS/LOWER OH VALLEY REGIONS...WITH MODERATE INSTABILITY /1000 TO 1500 J/KG MEAN-LAYER CAPE/ NOW AS FAR N AS CENTRAL IL. SUPERCELL STORMS ARE ONGOING ACROSS PARTS OF ERN MO INTO NRN AR...AS WELL AS ACROSS PARTS OF NERN MS/NRN AL WITHIN VERY MOIST/DESTABILIZING WARM SECTOR. ADDITIONAL CONVECTIVE DEVELOPMENT IS BEGINNING W OF ONGOING STORMS...FROM ERN OK/NWRN AR INTO CENTRAL MO/W CENTRAL IL...ALONG WRN FRINGES OF MDT RISK AREA. SHEAR AND INSTABILITY COMBINATION WILL REMAIN VERY FAVORABLE FOR LONG-LIVED SUPERCELL STORMS TODAY AND TONIGHT. EXPECT SEVERAL WAVES OF STORMS TO MOVE ACROSS THE MDT RISK AREA...AS FRONT REMAINS W OF THIS REGION AND LOW-LEVEL JET REDEVELOPS THIS EVENING IN RESPONSE TO THE NEXT MID-LEVEL SPEED MAX MOVING OUT OF THE SRN ROCKIES. ALONG WITH THREAT FOR DAMAGING WINDS AND HAIL...UPPER 60S TO LOW 70S DEWPOINTS AND A FURTHER INCREASE IN LOW-LEVEL SHEAR THIS EVENING OVERNIGHT WILL SUPPORT A CONTINUED THREAT FOR STRONG -- AND POTENTIALLY LONG-TRACK -- TORNADOES. WIDESPREAD SEVERE THREAT IS EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD. ONGOING CLUSTERS OF SUPERCELLS -- AND ACCOMPANYING SEVERE WEATHER POTENTIAL -- WILL CONTINUE SPREADING EWD/NEWD ACROSS MO/IL/AR...WITH POTENTIAL FOR CONTINUED STORM DEVELOPMENT EXPECTED THROUGH THE END OF THE PERIOD ACROSS WRN PORTIONS OF THE RISK AREA AS COLD FRONT APPROACHES. ..GOSS.. 09/22/2006  From swody1 at goshenarc.org Sat Sep 23 01:08:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 22 Sep 2006 21:08:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230109 SWODY1 SPC AC 230107 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0807 PM CDT FRI SEP 22 2006 VALID 230100Z - 231200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK INTO PARTS OF THE LOWER AND MIDDLE MS VALLEY AND WRN TN VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SRN PLAINS THROUGH PARTS OF THE MIDDLE AND LOWER MS VALLEY...TN AND OH VALLEYS AND GREAT LAKES... ...ERN OK THROUGH LOWER MS VALLEY AND WRN OH VALLEY... THIS EVENING A COLD FRONT EXTENDS FROM NRN MO SWWD THROUGH THE OK AND TX PANHANDLES. THIS FRONT WILL CONTINUE SEWD TONIGHT. A DRYLINE EXTENDS FROM W CNTRL TX NEWD THROUGH ERN OK INTO ERN KS WHERE IT INTERSECTS THE COLD FRONT. THIS BOUNDARY WILL RETREAT NWWD INTO CNTRL OK TONIGHT IN RESPONSE TO BACKING AND STRENGTHENING LOW LEVEL FLOW. NUMEROUS SUPERCELLS CONTINUE DEVELOPING FROM ERN OK...NRN AR INTO SRN IL...WRN KY AND WRN TN. THE LOW LEVEL JET WILL INTENSIFY FROM ERN OK...NRN TX INTO THE LOWER MS VALLEY THIS EVENING. THIS WILL OCCUR AS SURFACE LOW DEVELOPS OVER OK ALONG SEWD ADVANCING FRONT IN RESPONSE TO A MID LEVEL JET ADVANCING INTO THE SRN HIGH PLAINS. LOW LEVEL THETA-E ADVECTION AND LIFT AUGMENTED BY THE LOW LEVEL JET WILL CONTINUE TO ENHANCE THUNDERSTORM DEVELOPMENT IN CORRIDOR FROM ERN OK THROUGH NRN AR...INTO WRN KY AND NWRN TN. LOW LEVEL HODOGRAPHS AND DEEP LAYER SHEAR WILL REMAIN FAVORABLE FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES AND TORNADOES. MOREOVER...THESE STORMS SHOULD REMAIN IN A MORE FAVORABLE POSITION FOR UNINTERRUPTED MOIST UNSTABLE LOW LEVEL INFLOW. LARGE HAIL AND DAMAGING WIND MAY ALSO ACCOMPANY THE STRONGER STORMS. SOME THREAT FOR ISOLATED TORNADOES EXIST AS FAR EAST AS WRN PORTIONS OF THE OH VALLEY. HOWEVER...THE TORNADO THREAT DIMINISHES WITH ERN EXTENT INTO THIS REGION DUE TO LIMITED INSTABILITY. THE FRONT WILL EVENTUALLY INTERCEPT THE RETREATING DRYLINE FROM W CNTRL TX INTO CNTRL OK AND SERN KS LATER TONIGHT. AS THIS OCCURS ADDITIONAL STORMS WILL LIKELY DEVELOP. MUCH OF THIS ACTIVITY WILL PROBABLY EVOLVE INTO LINES. HOWEVER VERTICAL SHEAR PROFILES WILL SUPPORT EMBEDDED ORGANIZED STORMS STRUCTURES WITHIN THE LINE INCLUDING SUPERCELL AND BOW ECHOES. ..DIAL.. 09/23/2006  From swody1 at goshenarc.org Wed Sep 27 05:45:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 01:45:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270545 SWODY1 SPC AC 270544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT WED SEP 27 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST SWWD ACROSS THE LWR OH VLY TO THE OZARKS... ...SYNOPSIS... A POTENT NRN STREAM WILL CONTINUE TO DIG SEWD AND BEGIN TO CARVE OUT A COLD LONGWAVE TROUGH ACROSS THE ERN TWO-THIRDS OF THE COUNTRY WED. THE LEAD IMPULSE MOVING ACROSS THE UPPER MS VLY EARLY WED WILL QUICKLY TRANSLATE NEWD INTO SERN CANADA AS A MORE POTENT DISTURBANCE DIGS SEWD FROM SRN ALBERTA INTO THE DAKS AND MID-MS VLY WED AND WED NIGHT. IN THE LWR LVLS...WEAK COLD FRONT ASSOCD WITH THE FIRST WAVE WILL SETTLE ACROSS THE GRTLKS...MIDWEST AND SRN PLAINS BY WED NOON. AS THE STRONG IMPULSE DIGS SEWD...A POLAR FRONT WILL SURGE SEWD...REACHING THE WEAKER FRONT LATE WED AFTN...THEN SWEEP SEWD ACROSS THE GRTLKS...OH VLY...OZARKS AND SRN PLAINS BY 12Z THU. ...MIDWEST SWWD INTO THE LWR OH VLY AND OZARKS... AS THE LEAD WAVE SWINGS E THEN NEWD THROUGH THE CNTRL GRTLKS...A BAND OF CONVECTION WILL ACCOMPANY THE ASSOCD FRONT ACROSS THE CNTRL GRTLKS FROM WED MORNING INTO THE EARLY AFTN. THIS ACTIVITY SHOULD MOSTLY BE SUB-SEVERE...BUT GUSTY WINDS AND PERHAPS SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. MAIN SEVERE THREAT WILL OCCUR FROM MID-LATE WED AFTN INTO THE NIGHT FROM THE MIDWEST SWWD TO THE OZARKS. SWLY LOW-LVL FLOW WILL TRANSPORT/MAINTAIN LOW-MID 50S SFC DEW POINTS NEWD ALONG/AHEAD OF THE WEAKER FRONT THROUGH WED AFTN. BOUNDARY LAYER SHOULD HEAT RAPIDLY AND CONTRIBUTE TO MLCAPES RANGING FROM 500 J/KG ACROSS SERN LWR MI TO 1500 J/KG IN THE LWR OH VLY AND OZARKS. HEIGHTS WILL GRADUALLY FALL THROUGHOUT THE DAYTIME...BUT STRONGEST FALLS WILL OCCUR BY LATE WED AFTN. STRONG LARGE SCALE ASCENT...COOLING TEMPERATURES ALOFT AND INCREASING FRONTAL FORCING SHOULD BE FAVORABLE FOR TSTM INITIATION FROM SERN LWR MI ACROSS IND...SRN IL...SERN MO AND NRN AR NEAR/AFTER PEAK HEATING. VERTICAL SHEAR WILL BE MORE THAN SUFFICIENT FOR ORGANIZED STORMS...PROBABLY IN THE FORM OF LINE SEGMENTS. SUPERCELLS WILL BE POSSIBLE...PRIMARILY ACROSS THE LWR OH VLY WHERE MORE INSTABILITY WILL BE AVAILABLE FOR SUSTAINED UPDRAFTS. OTHERWISE...GIVEN THE INCREASING UNIDIRECTIONALITY TO THE WIND FIELDS WITH TIME...ANY LINE SEGMENT COULD CONTAIN BOWS/LEWPS. DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY THREATS. SOME SEVERE THREAT WILL LIKELY CONTINUE INTO THE EVE HOURS EWD INTO PARTS OF OH...NWRN/WRN KY AND NWRN TN. ...MID/LWR MO VLY... A SECONDARY REGION OF POSSIBLE SEVERE TSTMS WILL EVOLVE WED AFTN FROM PARTS OF ERN NEB SEWD INTO NWRN MO. CORE OF STRONGEST DCVA ASSOCD WITH THE STRONGER IMPULSE WILL TRACK SEWD ACROSS THIS REGION BETWEEN 18-00Z. LAPSE RATES WILL STRONGLY STEEPEN AS H5 TEMPERATURES AOB MINUS 20 DEG C SURGE SEWD ATOP RESIDUAL 50S DEW POINTS. IF BOUNDARY LAYER CAN HEAT...A BAND OF LOW-TOPPED AND FAST-MOVING TSTMS WILL DEVELOP GIVING POSSIBLE DAMAGING WINDS/HAIL. LOW-PROBABILITIES OF SEVERE WILL BE INTRODUCED...BUT IF THERMODYNAMICS APPEAR TO BE MORE FAVORABLE...A HIGHER RISK COULD BE ADDED IN LATER FCSTS. ..RACY.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 12:51:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 08:51:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271250 SWODY1 SPC AC 271249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT WED SEP 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDWEST...LWR OH VLY AND OZARKS... ...SYNOPSIS... HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WILL PREVAIL ACROSS NOAM THIS PERIOD. LEAD IMPULSE NOW CROSSING WI SHOULD CONTINUE E ACROSS MI AND SW ONTARIO AS STRONGER UPSTREAM DISTURBANCE NOW OVER ND DRIVES SEWD INTO SRN MO/IL BY 12Z THURSDAY. COLD FRONT NOW EXTENDING FROM THE UPR GRT LKS INTO KS WILL BE STRONGLY REINFORCED LATER TODAY/TONIGHT AS ND IMPULSE SWEEPS SEWD. THE FRONT SHOULD OVERTAKE LEAD WINDSHIFT/LEE TROUGH OVER THE OZARKS/SRN PLNS LATE THIS AFTERNOON...AND REACH THE LWR GRTLKS...LWR TN VLY AND CNTRL TX BY THURSDAY MORNING. ...MIDWEST SW INTO THE LWR OH VLY/OZARKS... A BAND OF SHOWERS/STORMS SHOULD CONTINUE TO PRECEDE LEAD IMPULSE CROSSING LWR MI...NRN IL AND NRN IND TODAY. MODERATE UNIDIRECTIONAL WLY FLOW AND MODEST INSTABILITY SUGGEST THAT THIS ACTIVITY SHOULD REMAIN MOSTLY SUB-SEVERE...BUT GUSTY WINDS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. A BIT LATER...MORE VIGOROUS STORMS EXPECTED TO FORM FROM MID TO LATE AFTN THROUGH TONIGHT ALONG STRENGTHENING COLD FRONT FROM SE LWR MI...NW OH...CNTRL/ERN IND AND ERN/SRN IL SW INTO THE OZARKS. MOISTURE WILL BE LIMITED BY LATE SEPTEMBER STANDARDS...WITH AVERAGE SURFACE DEWPOINTS LIKELY TO REMAIN IN THE LOW-MID 50S. BUT LOW TO MID LEVEL LAPSE RATES SHOULD STEEPEN GIVEN MODERATE TO STRONG SURFACE HEATING AND DIFFERENTIAL THERMAL ADVECTION. MLCAPE MAY REACH 500 J/KG IN NRN IND/NRN OH...AND 1500 J/KG IN THE LWR OH VLY/OZARKS. LARGELY UNIDIRECTIONAL W OR WSWLY FLOW WILL PREVAIL ACROSS THE SLIGHT RISK REGION...WITH 500 MB SPEEDS AROUND 40 KTS. THIS SETUP SHOULD SUPPORT ORGANIZED LINE SEGMENTS/CLUSTERS OF STORMS... INCLUDING POSSIBLE SUPERCELLS. BOWING SEGMENTS AND SUSTAINED UPDRAFTS MAY YIELD HIGH WIND AND HAIL...ESPECIALLY FROM THE LWR OH VLY INTO SRN MO/NRN AR...WHERE INSTABILITY/SHEAR COMBINATION SHOULD BE GREATEST. A LIMITED SEVERE THREAT MAY CONTINUE INTO LATE EVENING OVER NRN/CNTRL AR...W TN AND WRN/CNTRL KY AS FORCING FOR ASCENT INTENSIFIES IMMEDIATELY DOWNSTREAM FROM AMPLIFYING UPR TROUGH. ...MID/LWR MO VLY... AREA OF STRONG UVV ASSOCIATED WITH ND IMPULSE HAS SUPPORTED OVERNIGHT SHOWERS/TSTMS OVER ERN MT AND THE WRN DAKS. AS THIS UVV MAX CONTINUES SEWD...A SECONDARY REGION OF POSSIBLE SEVERE CONVECTION MAY EVOLVE WITH SURFACE HEATING OVER SE SD AND NRN/ERN NEB SE INTO WRN IA/NW MO. SATELLITE SUGGESTS THAT CLOUDS WILL COVER PARTS OF THE MID/LWR MO VLY THROUGH MIDDAY. BUT WITH CORE OF STRONGEST DCVA/MID LEVEL COOLING TRACKING OVER REGION FOLLOWING MAX HEATING...AND WITH DEWPOINTS REMAINING IN THE UPR 40S DESPITE LOW LEVEL CAA...SETUP MAY FOSTER DEVELOPMENT OF SCATTERED FAST-MOVING/ LOW-TOPPED TSTMS. GIVEN PROXIMITY OF 50+ KT MID LEVEL JET CORE AND COOL MID LEVEL TEMPS...THESE COULD YIELD A FEW SPOTS OF DAMAGING WIND/HAIL. ..CORFIDI/GUYER.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 12:57:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 08:57:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271257 SWODY1 SPC AC 271256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED SEP 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDWEST...LWR OH VLY AND OZARKS... ...SYNOPSIS... HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WILL PREVAIL ACROSS NOAM THIS PERIOD. LEAD IMPULSE NOW CROSSING WI SHOULD CONTINUE E ACROSS MI AND SW ONTARIO AS STRONGER UPSTREAM DISTURBANCE NOW OVER ND DRIVES SEWD INTO SRN MO/IL BY 12Z THURSDAY. COLD FRONT NOW EXTENDING FROM THE UPR GRT LKS INTO KS WILL BE STRONGLY REINFORCED LATER TODAY/TONIGHT AS ND IMPULSE SWEEPS SEWD. THE FRONT SHOULD OVERTAKE LEAD WINDSHIFT/LEE TROUGH OVER THE OZARKS/SRN PLNS LATE THIS AFTERNOON...AND REACH THE LWR GRTLKS...LWR TN VLY AND CNTRL TX BY THURSDAY MORNING. ...MIDWEST SW INTO THE LWR OH VLY/OZARKS... A BAND OF SHOWERS/STORMS SHOULD CONTINUE TO PRECEDE LEAD IMPULSE CROSSING LWR MI...NRN IL AND NRN IND TODAY. MODERATE UNIDIRECTIONAL WLY FLOW AND MODEST INSTABILITY SUGGEST THAT THIS ACTIVITY SHOULD REMAIN MOSTLY SUB-SEVERE...BUT GUSTY WINDS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. A BIT LATER...MORE VIGOROUS STORMS EXPECTED TO FORM FROM MID TO LATE AFTN THROUGH TONIGHT ALONG STRENGTHENING COLD FRONT FROM SE LWR MI...NW OH...CNTRL/ERN IND AND ERN/SRN IL SW INTO THE OZARKS. MOISTURE WILL BE LIMITED BY LATE SEPTEMBER STANDARDS...WITH AVERAGE SURFACE DEWPOINTS LIKELY TO REMAIN IN THE LOW-MID 50S. BUT LOW TO MID LEVEL LAPSE RATES SHOULD STEEPEN GIVEN MODERATE TO STRONG SURFACE HEATING AND DIFFERENTIAL THERMAL ADVECTION. MLCAPE MAY REACH 500 J/KG IN NRN IND/NRN OH...AND 1500 J/KG IN THE LWR OH VLY/OZARKS. LARGELY UNIDIRECTIONAL W OR WSWLY FLOW WILL PREVAIL ACROSS THE SLIGHT RISK REGION...WITH 500 MB SPEEDS AROUND 40 KTS. THIS SETUP SHOULD SUPPORT ORGANIZED LINE SEGMENTS/CLUSTERS OF STORMS... INCLUDING POSSIBLE SUPERCELLS. BOWING SEGMENTS AND SUSTAINED UPDRAFTS MAY YIELD HIGH WIND AND HAIL...ESPECIALLY FROM THE LWR OH VLY INTO SRN MO/NRN AR...WHERE INSTABILITY/SHEAR COMBINATION SHOULD BE GREATEST. A LIMITED SEVERE THREAT MAY CONTINUE INTO LATE EVENING OVER NRN/CNTRL AR...W TN AND WRN/CNTRL KY AS FORCING FOR ASCENT INTENSIFIES IMMEDIATELY DOWNSTREAM FROM AMPLIFYING UPR TROUGH. ...MID/LWR MO VLY... AREA OF STRONG UVV ASSOCIATED WITH ND IMPULSE HAS SUPPORTED OVERNIGHT SHOWERS/TSTMS OVER ERN MT AND THE WRN DAKS. AS THIS UVV MAX CONTINUES SEWD...A SECONDARY REGION OF POSSIBLE SEVERE CONVECTION MAY EVOLVE WITH SURFACE HEATING OVER SE SD AND NRN/ERN NEB SE INTO WRN IA/NW MO. SATELLITE SUGGESTS THAT CLOUDS WILL COVER PARTS OF THE MID/LWR MO VLY THROUGH MIDDAY. BUT WITH CORE OF STRONGEST DCVA/MID LEVEL COOLING TRACKING OVER REGION FOLLOWING MAX HEATING...AND WITH DEWPOINTS REMAINING IN THE UPR 40S DESPITE LOW LEVEL CAA...SETUP MAY FOSTER DEVELOPMENT OF SCATTERED FAST-MOVING/ LOW-TOPPED TSTMS. GIVEN PROXIMITY OF 50+ KT MID LEVEL JET CORE AND COOL MID LEVEL TEMPS...THESE COULD YIELD A FEW SPOTS OF DAMAGING WIND/HAIL. ..CORFIDI/GUYER.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 16:28:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 12:28:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271628 SWODY1 SPC AC 271627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CDT WED SEP 27 2006 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST SWWD ACROSS FROM THE LWR OH VLY TO THE OZARKS... ...SYNOPSIS... WV IMAGERY INDICATES A SERIES OF MID LEVEL IMPULSES WITHIN BROADER TROUGH OVERSPREADING THE CENTRAL U.S. THIS MORNING. ONE SYSTEM WILL CONTINUE EWD ACROSS THE CENTRAL GREAT LAKES...WHILE MORE SUBTLE SRN STREAM IMPULSE NOW SUSTAINING CONVECTION NEAR THE OZARKS IS ABSORBED INTO BROADER TROUGH AND SPREADS EWD TOWARDS THE LOWER OH RIVER VALLEY. AN EVEN STRONGER SYSTEM NOW MOVING ACROSS THE SD WILL AMPLIFY LARGER TROUGH AS IT DIGS SEWD INTO THE MID MS RIVER VALLEY OVERNIGHT. AT THE SURFACE...PRIMARY/LEADING COLD FRONT ASSOCIATED WITH THE BROAD MID/UPPER TROUGH EXTENDED FROM A LOW CENTER OVER NRN LOWER MI SSWWD INTO SWRN MO/NERN OK AT 15Z. THIS WILL CONTINUE ADVANCING ESEWD THROUGH THE DAY...AHEAD OF WHICH A GRADUAL INCREASE IN SURFACE DEW POINTS WILL OCCUR WITH READINGS IN THE MID 50S-LOW 60S EXPECTED FROM SERN MO/NRN AR INTO CENTRAL IND BY LATE IN THE DAY. ...OZARKS INTO THE SRN GREAT LAKES... MODELS VERY CONSISTENT IN INCREASING INSTABILITY AND THE POTENTIAL FOR DEEP MOIST CONVECTION ALONG AND JUST AHEAD OF THE SURFACE FRONT FROM NWRN AR INTO SRN IL AROUND 21Z...WITH PRIMARY QPF BETWEEN 21Z-00Z. FORECAST SOUNDINGS FROM THE NAM AND RUC INDICATE MLCAPE MAY APPROACH 2000 J/KG SHOULD SURFACE DEW POINTS REACH THE LOW 60S F NEAR PEAK HEATING INTO THE LOWER OH RIVER VALLEY. WILL MOST LIKELY SEE AN AXIS OF 1000-1500 J/KG MLCAPE EXTENDING FROM SWRN MO INTO SWRN/CENTRAL IND BY 21Z...WITH A HIGHER MAX POSSIBLE NEAR THE LOWER OH RIVER VALLEY. MLCAPE NEARER 500 J/KG CAN BE EXPECTED INTO THE NERN IND/NWRN OH. MODEST TO STRONG WNWLY FLOW ALOFT WILL ALSO SUPPORT EFFECTIVE SHEAR AROUND 40 KT...SUGGESTING A FEW SUPERCELLS WILL BE POSSIBLE ALONG WITH AT LEAST A THREAT OF A TORNADO OR TWO. HOWEVER...OVERALL EVOLUTION INTO ONE OR MORE SMALL LINES/CLUSTERS IS THE MORE LIKELY SCENARIO UNDER A NEAR-UNIFORM WLY FLOW THROUGH THE MID LEVELS. LARGE HAIL AND DAMAGING WINDS WILL LIKELY BE PRIMARY SEVERE THREATS. OVERALL SEVERE THREAT IS EXPECTED TO BECOME MORE LIMITED WITH NEWD EXTENT TOWARDS THE SRN GREAT LAKES. ...CENTRAL PLAINS... A SECONDARY REGION OF POSSIBLE SEVERE TSTMS WILL EVOLVE THIS AFTERNOON FROM PARTS OF SERN SD/NEB SEWD INTO NWRN MO/WRN IA. CORE OF STRONGEST DCVA ASSOCD WITH APPROACHING IMPULSE WILL TRACK SEWD ACROSS THIS REGION BETWEEN 18-00Z. LAPSE RATES WILL STRONGLY STEEPEN AS H5 TEMPERATURES AOB MINUS 20 DEG C SURGE SEWD ATOP RESIDUAL 50S DEW POINTS. IF BOUNDARY LAYER CAN HEAT...A BAND OF LOW-TOPPED AND FAST-MOVING TSTMS WILL DEVELOP PRODUCING POSSIBLE HAIL/STRONG WINDS. ..EVANS/CROSBIE.. 09/27/2006  From swody1 at goshenarc.org Wed Sep 27 19:42:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 15:42:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271943 SWODY1 SPC AC 271941 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT WED SEP 27 2006 VALID 272000Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM IND TO AR... FRONTAL FORCING APPEARS TO BE AIDING RECENT THUNDERSTORM DEVELOPMENT ACROSS WCNTRL IND...INITIALLY OVER MONTGOMERY AND PARK COUNTIES. BOUNDARY LAYER AIRMASS IS NOT TERRIBLY UNSTABLE...ROUGHLY 500-1000 J/KG MLCAPE...BUT LARGE SCALE SUPPORT IS CERTAINLY FOCUSED ACROSS THIS PORTION OF THE FRONTAL ZONE. LATEST THINKING IS THUNDERSTORMS WILL CONTINUE TO EVOLVE WITHIN BROADER ZONE OF DEEPENING SHOWERS ACROSS THE REMAINDER OF CNTRL/NERN IND. HAIL SHOULD ACCOMPANY THE STRONGER ECHOES...WHILE GUSTY WINDS MAY ALSO BE NOTED. A SOMEWHAT DIFFERENT CONVECTIVE MODE IS EVOLVING ACROSS AR INTO SERN MO THIS AFTERNOON. WV IMAGERY INDICATES GOOD CONTINUITY WITH WEAK UPPER IMPULSE THAT HAS SHEARED EWD ACROSS NM/OK INTO WCNTRL AR. THIS FEATURE HAS A HISTORY OF MID LEVEL CONVECTION WITH ISOLATED THUNDERSTORMS. OVER THE LAST HOUR OR SO BOUNDARY LAYER HAS APPARENTLY WEAKENED INHIBITION SUFFICIENTLY FOR RENEWED ROBUST NEAR-SFC BASED THUNDERSTORMS NORTH OF I-40 FROM CRAWFORD TO NEWTON COUNTIES IN AR...JUST NE OF FSM. AREAL COVERAGE SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HOURS WITH ENEWD DEVELOPMENT EXPECTED ACROSS THE REMAINDER OF NRN AR INTO SERN MO...EVENTUALLY SPREADING DOWNSTREAM INTO WRN KY/TN. LARGE HAIL AND PERHAPS SOME GUSTY WINDS SHOULD OCCUR WITH STRONGER STORMS. LATER THIS EVENING...COLD FRONT SHOULD CATCH UP WITH THIS ACTIVITY FORCING SQUALL LINE DEVELOPMENT DOWNSTREAM INTO PORTIONS OF CNTRL KY/MIDDLE TN. THIS LATE NIGHT ACTIVITY SHOULD GRADUALLY DECREASE IN INTENSITY AS BOUNDARY LAYER COOLS AND INSTABILITY WEAKENS. ..DARROW.. 09/27/2006  From swody1 at goshenarc.org Thu Sep 28 00:57:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 27 Sep 2006 20:57:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280057 SWODY1 SPC AC 280055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT WED SEP 27 2006 VALID 280100Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL AR TO N-CENTRAL KY... ...SYNOPSIS... DEEP SYNOPTIC TROUGH WILL CONTINUE TO DOMINATE MOST OF CONUS FROM ERN PLAINS TO ATLANTIC COAST...WITH RIDGE ACROSS GREAT BASIN REGION. MOISTURE CHANNEL IMAGERY AND AVAILABLE UPPER AIR DATA INDICATE EJECTING SHORTWAVE TROUGH INVOF QUE/ONT BORDER...TO BE REPLACED BY UPSTREAM SHORTWAVE NOW DIGGING SEWD ACROSS IA. WEAK UPPER LEVEL PERTURBATION THAT CROSSED SRN PLAINS OVERNIGHT NOW IS BARELY EVIDENT ACROSS AR...AND SHOULD CONTINUE TO WEAKEN AHEAD OF PROGRESSIVE IA TROUGH. AT SFC...COLD FRONT WAS ANALYZED AT 00Z FROM SERN LOWER MI SWWD ACROSS CENTRAL INDIANA...OZARKS OF SRN MO/NRN AR...S-CENTRAL OK AND NW TX. PREFRONTAL SFC TROUGH AND WIND SHIFT WAS EVIDENT FROM W-CENTRAL TX ACROSS SERN OK AND CENTRAL AR...NORTHEASTWARD INTO ONGOING CONVECTION OVER AR. PREFRONTAL TROUGH THEN WAS COLLOCATED WITH BROKEN BAND OF TSTMS NEAR A LINE FROM ARG...PAH...OWB...30 NNW CVG...20 NNW CLE. BOTH TROUGH AND FRONT ARE FCST TO MOVE EWD ACROSS OH...KY...MUCH OF WRN-MID TN..ARKLATEX REGION AND W-CENTRAL TX THROUGH REMAINDER PERIOD. ...AR TO OH VALLEY... BEST-ORGANIZED POTENTIAL FOR SVR WIND AND HAIL WILL BE IN AND NEAR WW 801 FOR ANOTHER 2-3 HOURS...WHERE EFFECTIVE BULK SHEAR...CONVERGENCE...MOISTURE AND BUOYANCY ARE MAXIMIZED REGIONALLY ATTM. REF WW 801 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST INFO. AFTER SUNSET...SBCINH IS FCST TO INCREASE GRADUALLY AS MRGLLY MOIST SFC AIR MASS DIABATICALLY COOLS...REDUCING POTENTIAL FOR SVR GUSTS TO REACH SFC. THIS ALSO WILL DIMINISH SBCAPE TO NEAR ZERO...WITH ANY NOCTURNAL TSTMS SUPPORTED BY NARROW PLUME OF ELEVATED WAA AND WEAK MOISTURE TRANSPORT. THEREFORE...SVR PROBABILITIES WILL BECOME SMALLER WITH TIME AND WITH EWD EXTENT AS PRIMARY CONVECTIVE BAND MOVES EWD. ..EDWARDS.. 09/28/2006