From swody1 at goshenarc.org Mon Jan 1 00:54:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 19:54:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010058 SWODY1 SPC AC 010056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST SUN DEC 31 2006 VALID 010100Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... CLOSED UPPER LOW...NOW CENTERED OVER MID MS VALLEY...IS EXPECTED TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS NEWD INTO THE GREAT LAKES REGION OVERNIGHT. MEANWHILE...PROGRESSIVE UPSTREAM SHORT WAVE TROUGH WILL DIG SEWD INTO THE MS VALLEY...MAINTAINING ELONGATED UPPER TROUGH ALONG THE MS VALLEY IN WAKE OF EJECTING UPPER LOW. AT THE SURFACE...AREA OF LOW PRESSURE LOCATED OVER SWRN WI WILL TRACK NEWD INTO THE UPPER GREAT LAKES TONIGHT...AS TRAILING COLD FRONT SPREADS EWD AND SHOULD EXTEND FROM THE LOW ACROSS THE LOWER GREAT LAKES AND CENTRAL APPALACHIANS SWWD TO THE NERN GULF. ...NERN IL/NRN IND TO SRN LOWER MI... ASCENT ALONG LEADING EDGE OF UPPER LOW/VORTEX COMBINED WITH STEEPENING LAPSE RATES PER MID LEVEL COOLING ATOP LOW LEVEL THERMAL RIDGE ARE EXPECTED TO MAINTAIN ONGOING ERN IL TSTM CLUSTER AS THE UPPER LOW TRACKS NE TOWARD THE GREAT LAKES REGION. FOR ADDITIONAL INFORMATION ABOUT THIS ACTIVITY AND ATTENDANT ISOLATED SEVERE THREAT...PLEASE REFER TO SPC MESOSCALE DISCUSSION 0001. ...NRN FL/SERN GA NWD TO ERN TN/WRN NC/SWRN VA... UPPER LEVEL DIFFLUENT FLOW REGIME LOCATED E AND SE OF UPPER LOW IS EXPECTED TO MAINTAIN TWO ONGOING AREAS OF CONVECTION...ONE OVER SERN GA/NRN FL AND THE SECOND ALONG THE COLD FRONT FROM NRN GA NWD INTO UPPER OH VALLEY. AIR MASS IN ADVANCE OF SERN GA/NWRN FL CONVECTIVE LINE IS MARGINALLY UNSTABLE...WITH EFFECTIVE BULK SHEAR VALUES OF 35-45 KT REMAINING FAVORABLE FOR SOME ORGANIZATION AND ATTENDANT LOW PROBABILITY FOR PRIMARILY AN ISOLATED DAMAGING WIND GUST. FARTHER N...FORCING SHOULD REMAIN SUFFICIENT ALONG THE COLD FRONT FOR ADDITIONAL CONVECTION AND A FEW EMBEDDED TSTMS ACROSS PARTS OF THE SRN AND CENTRAL APPALACHIANS. HOWEVER...WEAK LAPSE RATES SHOULD PRECLUDE A SEVERE WIND THREAT FROM NRN GA/ERN TN INTO SWRN VA/WRN NC THIS EVENING. ..PETERS.. 01/01/2007  From swody1 at goshenarc.org Wed Jan 3 16:27:08 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 11:27:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031631 SWODY1 SPC AC 031629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST WED JAN 03 2007 VALID 031630Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...TX... UPPER LOW OVER NORTHERN MEXICO IS FORECAST TO TRACK SLOWLY EASTWARD TODAY...AND INTO SOUTHWEST TX OVERNIGHT. MEANWHILE...LARGE SCALE DIFFLUENT FLOW PATTERN AND UPWARD FORCING WILL CONTINUE TO OVERSPREAD MUCH OF TX THROUGH THE FORECAST PERIOD. LOW LEVEL CYCLOGENESIS IS EXPECTED TO OCCUR ALONG THE MIDDLE TX GULF COAST THIS AFTERNOON AND EVENING...WITH MODELS SUGGESTING THAT SURFACE LOW WILL LIE VERY NEAR THE COAST. AIR MASS JUST OFFSHORE CONTINUES TO SLOWLY MODIFY WITH DEWPOINTS IN THE MID/UPPER 60S LIKELY OVERNIGHT. THIS WILL RESULT IN AT LEAST MARGINAL SURFACE-BASED INSTABILITY IN THE WARM SECTOR OF THE LOW /MLCAPE OF 300-500 J/KG/. IF WARM SECTOR CAN MOVE INLAND...VERTICAL SHEAR PROFILES WOULD BE FAVORABLE FOR SUPERCELL STORMS AND POSSIBLE TORNADOES. THIS CONDITIONAL THREAT APPEARS VERY LIMITED IN TEMPORAL AND AREAL EXTENT...SO WILL ONLY MAINTAIN LOW SEVERE PROBABILITIES. GUSTY WINDS AND HAIL WOULD ALSO BE POSSIBLE WITH STRONGER STORMS OVER SOUTH AND SOUTHEAST TX OVERNIGHT. ELSEWHERE...SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY OVER THE FL PENINSULA WHERE MOIST AND MODERATELY UNSTABLE AIR MASS IS PRESENT. ISOLATED LIGHTNING STRIKES WILL ALSO BE POSSIBLE THROUGH THE DAY ALONG THE COAST OF WA. NO ORGANIZED SEVERE STORMS ARE EXPECTED IN THESE AREAS. ..HART.. 01/03/2007  From swody1 at goshenarc.org Wed Jan 3 19:52:40 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 14:52:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031956 SWODY1 SPC AC 031954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST WED JAN 03 2007 VALID 032000Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE...LOW-AMPLITUDE WAVE TRAIN WILL CONTINUE TO CHARACTERIZE NEARLY ZONAL NRN STREAM FLOW FROM PACIFIC NW EWD ACROSS GREAT LAKES AND NEW ENGLAND. SRN STREAM CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NWRN MEX -- IS FCST TO PIVOT ENEWD ACROSS BIG BEND REGION OF SW TX AND ADJACENT SERRANIAS DEL BURRO RANGE OF NRN MEX. AS ASSOCIATED MID-UPPER TROUGH APCHS S TX AND NWRN GULF...SFC CYCLOGENESIS IS FCST OFFSHORE BRO...INVOF INFLECTION POINT ON SFC FRONT. THIS LOW SHOULD LIFT NEWD TOWARD UPPER TX COAST...AND MAY REACH COAST AT OR SHORTLY AFTER END OF PERIOD. ...S TX... SCATTERED TO WIDELY SCATTERED ELEVATED TSTMS ALREADY ARE EVIDENT FROM N-CENTRAL MEX NEWD ACROSS PORTIONS SWRN...CENTRAL AND E TX. ERN-MOST OF THIS ACTIVITY IS OCCURRING ALONG FARTHEST INLAND AND MOST HIGHLY ELEVATED REACHES OF LOW LEVEL WAA/MOIST ADVECTION REGIME -- WHICH WILL SHIFT ACROSS PORTIONS ARKLATEX REGION TO LOWER MS VALLEY THROUGH REMAINDER PERIOD. MEANWHILE...AVAILABLE BUOYANCY ALOFT AND OVERALL CONVECTIVE COVERAGE EACH WILL INCREASE ACROSS MUCH OF S TX AS MOISTURE CONTINUES TO INCREASE ABOVE SFC...LAPSE RATES STRENGTHEN AS LARGE SCALE ASCENT INCREASES AHEAD OF UPPER LOW...AND ISENTROPIC ASCENT RAISES PARCELS TO LFC. EFFECTIVE SHEAR PROFILES WILL BECOME FAVORABLE FOR SOME STORMS TO ROTATE ALOFT...ENHANCING HAIL POTENTIAL. AIR MASS ALONG AND S OF MARINE FRONT -- NE OF SFC LOW -- WILL BE CHARACTERIZED BY ENLARGED LOW LEVEL HODOGRAPHS..SFC DEW POINTS MID 60S TO NEAR 70 F...AND ENOUGH SFC THETAE TO SUPPORT MLCAPES 500-1000 J/KG. MOST OF THIS AIR MASS SHOULD REMAIN OFFSHORE...HOWEVER CONDITIONAL TORNADO AND DAMAGING WIND RISK EXISTS LATE TONIGHT NEAR MID/UPPER TX COAST...BASED ON MRGL POTENTIAL FOR MARINE FRONT TO REACH SHORE BEFORE 4/12Z. ..EDWARDS.. 01/03/2007  From swody1 at goshenarc.org Thu Jan 4 00:48:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 19:48:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040052 SWODY1 SPC AC 040050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 PM CST WED JAN 03 2007 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...S AND SERN TX COASTAL AREA... A SURFACE FRONT EXTENDS FROM A WEAK LOW JUST OFF THE S TX COAST EWD THROUGH THE NRN GULF OF MEXICO. AN UPPER LOW OVER NRN MEXICO WILL ADVANCE SLOWLY EAST TONIGHT REACHING SWRN TX BY THE END OF THIS PERIOD. SLY LOW LEVEL JET WILL INTENSIFY OVER CNTRL AND ERN TX WITHIN ZONE OF UPPER DIVERGENCE AND LARGE SCALE ASCENT DOWNSTREAM FROM THE UPPER LOW. THIS WILL MAINTAIN ISENTROPIC ASCENT AND A FAVORABLE ENVIRONMENT FOR STORMS TO CONTINUE DEVELOPING OVERNIGHT. THE BOUNDARY LAYER N OF SURFACE FRONT IS STABLE...SO STORMS WILL REMAIN ELEVATED MUCH OF THE REST OF THIS PERIOD. AS THE LOW LEVEL JET INTENSIFIES...WRN PORTION OF THE BOUNDARY WILL BEGIN TO LIFT NWD THROUGH THE NWRN GULF...POSSIBLY REACHING THE SERN TX COAST TOWARD THE END OF THIS PERIOD. AS THIS OCCURS THE BOUNDARY LAYER WILL DESTABILIZE AND STORMS MAY BECOME CLOSE ENOUGH TO SURFACE BASED TO POSE A SEVERE THREAT. LOW LEVEL AND DEEP LAYER SHEAR PROFILES WILL REMAIN FAVORABLE FOR ORGANIZED STORMS INCLUDING SUPERCELLS WITH ANY SURFACE BASED STORMS. PRIMARY THREAT WILL BE AN ISOLATED TORNADO OR DAMAGING WIND GUST CONDITIONAL UPON SUFFICIENT BOUNDARY LAYER DESTABILIZATION. GIVEN THE FRONT IS EXPECTED TO REMAIN OFFSHORE UNTIL NEAR THE END OF THIS PERIOD...THREAT DOES NOT APPEAR SUFFICIENT TO WARRANT MORE THAN 5% PROBABILITIES AT THIS TIME. ..DIAL.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 05:33:16 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 00:33:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040537 SWODY1 SPC AC 040535 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CST WED JAN 03 2007 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EXTREME SERN TX THROUGH THE CNTRL GULF COASTAL AREA... ...NWRN THROUGH CNTRL GULF COASTAL AREA... UPPER LOW OVER NRN MEXICO WILL EJECT NEWD THROUGH CNTRL AND ERN TX TODAY REACHING THE LOWER MS VALLEY TONIGHT AS A POSITIVELY TILTED UPPER TROUGH MOVES ONTO THE W COAST. A 50 TO 60 KT LOW LEVEL JET WILL SHIFT SLOWLY EWD THROUGH THE LOWER MS VALLEY WITHIN ZONE OF HEIGHT FALLS AND ASCENT DOWNSTREAM FROM THE UPPER LOW. THE STRONG SLY LOW LEVEL JET SHOULD CONTRIBUTE TO NWD ADVANCE OF WARM FRONT OVER THE NWRN GULF. BY LATE MORNING OR MID DAY THIS FRONT SHOULD EXTEND EWD ALONG THE LA COAST FROM A SURFACE LOW IN SWRN LA WITH A COLD FRONT EXTENDING SWD FROM THE LOW THROUGH THE WRN GULF. THUNDERSTORMS WILL CONTINUE WITHIN BELT OF ASCENT E OF UPPER LOW AND SHIFT THROUGH ERN TX AND THE LOWER MS VALLEY. MUCH OF THE CONVECTION WILL REMAIN ELEVATED. HOWEVER...AS THE WARM FRONT APPROACHES THE COAST...NWD ADVECTION OF UPPER 60S DEWPOINTS SHOULD CONTRIBUTE TO BOUNDARY LAYER DESTABILIZATION. MODEST MID LEVEL LAPSE RATES AND LIMITED SURFACE HEATING SHOULD RESULT IN MARGINAL INSTABILITY WITH MUCAPE AOB 500 J/KG. AS DEWPOINTS INCREASE AND THE BOUNDARY LAYER DESTABILIZES...STORMS MAY BECOME CLOSE ENOUGH TO SURFACE BASED TO POSE A SEVERE THREAT FROM EXTREME SERN TX INTO SRN LA...AND THE BOOTHEEL OF MS. LOW LEVEL HODOGRAPHS AND CLOUD LAYER SHEAR WILL SUPPORT ORGANIZED STORMS INCLUDING EMBEDDED SUPERCELLS WITH ANY SURFACE BASED ACTIVITY. PRIMARY THREATS WILL BE ISOLATED DAMAGING WIND AND AN ISOLATED TORNADO OR TWO. ..DIAL.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 12:28:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 07:28:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041232 SWODY1 SPC AC 041230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0630 AM CST THU JAN 04 2007 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM SRN LA INTO THE WRN FL PANHANDLE... ...NRN GULF COAST TODAY INTO EARLY TONIGHT... A CLOSED MID LEVEL LOW NEAR DEL RIO TX THIS MORNING WILL MOVE GENERALLY EWD OVER CENTRAL/SE TX TODAY...REACHING THE LOWER MS VALLEY TONIGHT...AS AN UPSTREAM WAVE DIGS ESEWD FROM THE PAC COAST TO THE SRN GREAT BASIN. AT THE SURFACE...A WEAK WAVE NEAR THE UPPER TX COAST WILL DEVELOP NEWD/INLAND ACROSS SW/CENTRAL LA IN ADVANCE OF THE TX MID LEVEL TROUGH. A WARM FRONT WILL ALSO LIFT NWD ACROSS THE N CENTRAL/NE GULF STATES ALLOWING A MOIST MARITIME AIR MASS /BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S/ TO SPREAD INLAND. THIS MOISTURE WILL CONTRIBUTE TO AT LEAST WEAK INSTABILITY TODAY ALONG THE I-10 CORRIDOR FROM LA TO THE FL PANHANDLE. THE MAGNITUDE OF THE INSTABILITY...HOWEVER...WILL BE LIMITED BY RATHER POOR MID LEVEL LAPSE RATES. A BROAD SWATH OF RAIN/EMBEDDED THUNDERSTORMS IS DEVELOPING EWD/NEWD ACROSS THE NW GULF AND E TX IN ADVANCE OF THE MID LEVEL TROUGH. THE CONVECTION INLAND IS ELEVATED THIS MORNING...AND WILL NOT LIKELY BECOME SURFACE-BASED OVER LAND UNTIL BOUNDARY LAYER DEWPOINTS INCREASE TO THE MID-UPPER 60S. ONCE LOW-LEVEL MOISTENING BECOMES SUFFICIENT BY ABOUT 18Z...VERTICAL SHEAR WILL BE FAVORABLE FOR SUPERCELLS...ESPECIALLY ALONG THE RETREATING WARM FRONT. THE COMBINATION OF WEAK INSTABILITY/MOIST PROFILES AND STRONG LOW-LEVEL SHEAR COULD SUPPORT A COUPLE OF TORNADOES THIS AFTERNOON INTO EARLY TONIGHT...ALONG WITH THE THREAT FOR ISOLATED DAMAGING WINDS WITH BOW ECHO STRUCTURES EMBEDDED IN THE LARGER CONVECTIVE BAND. ..THOMPSON.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 16:19:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 11:19:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041621 SWODY1 SPC AC 041618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1018 AM CST THU JAN 04 2007 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS VALLEY AND CENTRAL GULF COAST REGION... ...LOWER MS VALLEY... PROGRESSIVE UPPER LOW OVER TX IS FORECAST TO CONTINUE TO MOVE EASTWARD AND INTO THE LOWER MS VALLEY BY 05/12Z. THE ASSOCIATED SURFACE LOW...NOW NEAR THE MOUTH OF THE SABINE RIVER...WILL DEVELOP NORTHEASTWARD ACROSS LA AND INTO NORTHERN MS. STRONG LARGE SCALE FORCING FOR ASCENT ACROSS THE LOWER MS VALLEY...COUPLED WITH INCREASING LOW LEVEL MOISTURE AND MARGINAL INSTABILITY...WILL AID IN THE THREAT FOR SCATTERED THUNDERSTORMS THROUGHOUT THE FORECAST PERIOD FROM LA/AR INTO THE SOUTHEAST STATES. RICH LOW LEVEL MOISTURE REMAINS OFF THE LA COAST AT THIS TIME...AND EXTENT OF NORTHWARD PENETRATION IS UNCERTAIN. HOWEVER...FAVORABLE VERTICAL SHEAR PROFILES WILL SUPPORT A RISK OF SUPERCELL STORM STRUCTURES IF SUFFICIENT MOISTURE CAN BE TRANSPORTED INLAND. GUSTY WINDS AND ISOLATED TORNADOES WOULD BE THE MAIN THREATS. REFER TO MCD NUMBER 5 FOR FURTHER DETAILS. A MORE ORGANIZED SQUALL LINE WILL BE POSSIBLE THIS EVENING AND TONIGHT ACROSS PARTS OF MS/AL AS MAIN UPPER TROUGH ROTATES EASTWARD. CONDITIONAL RISK OF DAMAGING WINDS AND PERHAPS A TORNADO WILL CONTINUE WITH THIS ACTIVITY...IF SUFFICIENT SURFACE-BASED INSTABILITY IS PRESENT. ..HART.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 19:51:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 14:51:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041955 SWODY1 SPC AC 041952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0152 PM CST THU JAN 04 2007 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE WRN/CNTRL GULF COASTAL AREA... ...CNTRL/WRN GULF COASTAL AREA... WATER VAPOR IMAGERY SUGGESTS THAT THE CNTRL TX UPPER LOW WAS BEGINNING TO EJECT ENEWD IN AN INCREASINGLY NEGATIVE TILT ORIENTATION. DIVERGENCE/DIFFLUENT REGIME AHEAD OF THIS SYSTEM WAS SUPPORTING A WIDESPREAD AREA OF CONVECTION ACROSS THE WRN GULF COASTAL AREA NWD INTO THE MID-SOUTH. WEAK CYCLOGENESIS WAS OCCURRING OVER NWRN LA AND THE 1010 HPA SFC LOW VCNTY KSHV SHOULD MIGRATE NEWD TOWARD THE KMEM VCNTY LATER THIS EVE. JUST ABOVE THE SFC...A STRONG H9-H8 SLY LLJ EXISTED JUST AHEAD OF A WEAK FRONT FROM SRN LA INTO NWRN MS. BOUNDARY LAYER HAS GRADUALLY MODIFIED WITH A WARM FRONT DEVELOPING ACROSS SRN LA VCNTY KPOE EWD TO JUST S OF THE KMSY AREA. TO THE S OF THE FRONT...TEMPERATURES/DEW POINTS HAVE WARMED TO NEAR 70/MID 60S DEG F RESPECTIVELY. MODIFIED 18Z SLIDELL RAOB SUGGESTS THAT SFC-BASED TSTMS WILL BE POSSIBLE THROUGH THIS EVE...PRIMARILY ACROSS ERN LA AND EXTREME SRN PARTS OF MS/AL WHERE MLCAPES WILL APPROACH 500 J PER KG. ANY STORM THAT DEVELOPS ALONG/S OF THE WARM FRONT WILL EXIST IN DEEP LAYER SHEAR OF AROUND 50 KTS AND SUPERCELLS WILL REMAIN POSSIBLE. THOUGH DAMAGING WINDS SHOULD BE THE PRIMARY THREAT...AS STORMS APPROACH AND CROSS OVER THE WARM FRONT...SFC-BASED STORMS DEVIATING TO THE RIGHT OF THE MEAN FLOW WILL OBTAIN 0-1KM SRH IN EXCESS OF 250 MS/S2. THUS...A BRIEF TORNADO MAY ALSO OCCUR. THESE SEVERE THREATS WILL EXTEND E INTO THE EXTREME WRN FL PNHDL BY 12Z. FARTHER N...THE COLUMN WILL CONTINUE TO DESTABILIZE THROUGH THE NIGHT ACROSS CNTRL/NRN PORTIONS OF MS/AL AS WARM/MOIST ADVECTION OCCUR. TSTMS THIS FAR N WILL LIKELY BE ROOTED ABOVE THE SFC...MITIGATING THREATS FOR DAMAGING WINDS OR TORNADOES. ..RACY.. 01/04/2007  From swody1 at goshenarc.org Fri Jan 5 00:38:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 19:38:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050042 SWODY1 SPC AC 050040 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 PM CST THU JAN 04 2007 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL GULF COASTAL AREA... ...CNTRL GULF COASTAL AREA... PROGRESSIVE UPPER LOW OVER ERN TX WILL EJECT ENEWD INTO THE LOWER MS VALLEY TONIGHT. A 40 TO 50 KT SLY LOW LEVEL JET WILL PERSIST WITHIN THE ZONE OF UPPER DIVERGENCE AND ASCENT JUST DOWNSTREAM FROM THE SHORTWAVE TROUGH AND SHIFT EWD THROUGH THE SERN STATES. A WARM FRONT EXTENDS FROM A SURFACE LOW OVER LA EWD THROUGH SRN MS...SRN AL AND INTO SRN GA. A COLD FRONT EXTENDS SWD FROM THE LOW THROUGH SERN LA INTO THE NWRN GULF. BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 60S HAVE SPREAD INLAND NEAR AND S OF THE WARM FRONT. THE SLY LOW LEVEL JET MAY SUPPORT A NWD ADVANCE OF THE WARM FRONT OVERNIGHT...ALLOWING THE MOIST AND MARGINALLY UNSTABLE WARM SECTOR TO SPREAD FARTHER INLAND. BAND OF THUNDERSTORMS WILL PERSIST WITHIN ZONE OF DEEP LAYER ASCENT ALONG AND JUST AHEAD OF THE COLD FRONT AND SHIFT EWD OVERNIGHT. STORMS NEAR AND S OF THE WARM FRONT WILL REMAIN CLOSE ENOUGH TO SURFACE BASED TO MAINTAIN A SEVERE THREAT. LARGE LOW LEVEL HODOGRAPHS AND FAVORABLE DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS INCLUDING BOW ECHOES AND SUPERCELLS. ISOLATED TORNADOES AND DAMAGING WIND WILL REMAIN THE PRIMARY THREATS. ..DIAL.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 05:33:51 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 00:33:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050537 SWODY1 SPC AC 050535 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SERN STATES...NRN FL INTO THE ERN CAROLINAS... ...SERN U.S. THROUGH ERN CAROLINAS... SHORTWAVE TROUGH NOW MOVING INTO THE MS VALLEY WILL EJECT NE THROUGH THE REMAINDER OF THE SERN STATES FRIDAY THROUGH FRIDAY NIGHT AND SLOWLY DEAMPLIFY. A 40 TO 50 KT SLY LOW LEVEL JET WILL SHIFT EWD THROUGH THE SERN U.S. IN ADVANCE OF THIS FEATURE DURING THE DAY AND LIFT NWD INTO THE MID ATLANTIC AND NERN STATES FRIDAY NIGHT. POORLY DEFINED WARM FRONT EXTENDS FROM SRN SC WWD THROUGH S CNTRL MS AND NERN LA WHERE IT INTERSECTS A COLD FRONT THAT STRETCHES SWD INTO THE GULF. LOW LEVEL DEWPOINTS IN THE MID 50 UPPER 60S WILL CONTINUE TO ADVECT NWD THROUGH PARTS OF AL...GA AND THE ERN CAROLINAS FRIDAY AS THE LOW LEVEL JET SHIFTS EWD. THIS SHOULD RESULT IN AT LEAST MARGINAL INSTABILITY WITH MLCAPE GENERALLY FROM 400 TO 800 J/KG WITHIN THE WARM SECTOR. STRONGER INSTABILITY MAY DEVELOP OVER PARTS OF SRN GA INTO NRN FL WHERE STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER TROUGH MAY OVERTAKE THE MOIST BOUNDARY LAYER. BAND OF PRE-FRONTAL STORMS WILL LIKELY PERSIST AND SPREAD EAST THROUGH THE SERN U.S. WITHIN ZONE OF UPPER DIVERGENCE AND DEEP LAYER ASCENT ACCOMPANYING THE EJECTING UPPER TROUGH. LOW LEVEL HODOGRAPHS AND DEEP LAYER SHEAR WILL REMAIN SUFFICIENT FOR ORGANIZED STORMS WITH SUPERCELLS AND LEWP STRUCTURES. PRIMARY THREATS WILL CONTINUE TO BE ISOLATED TORNADOES AND DAMAGING WIND WITH ANY SURFACE BASED STORMS. ..DIAL.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 12:27:52 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 07:27:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051231 SWODY1 SPC AC 051229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 AM CST FRI JAN 05 2007 VALID 051300Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE SOUTHEASTERN STATES... ...SYNOPSIS... VIGOROUS UPPER TROUGH CURRENTLY LOWER MS VALLEY EXPECTED TO BEGIN FILLING BY THIS AFTERNOON AS A LARGE SCALE TROUGH RAPIDLY APPROACHES FROM THE WRN U.S. THIS LOWER MS VALLEY TROUGH WILL MOVE TO THE ERN CAROLINAS BY 06Z AND OFFSHORE BY 12Z SAT SIGNIFICANTLY WEAKENED. THE SHARPNESS ON THE LOWER MS VALLEY TROUGH ON WATER VAPOR IMAGERY AND ONGOING IMPRESSIVE SQUALL LINE MOVING THRU AL SUGGEST THAT THE MODELS COULD BE A LITTLE QUICK ON THE WEAKENING PROCESS. AN UNSEASONABLY WARM AND MOIST AIR MASS CONTINUES TO SPREAD INLAND IN ADVANCE OF THE SQUALL LINE EWD THRU THE CAROLINAS. WHILE THE TROUGH WILL BE WEAKENING STEADILY FROM THIS AFTERNOON THRU THE REMAINDER OF THE PERIOD CONDITIONS ARE EXPECTED TO REMAIN FAVORABLE FOR SEVERE THUNDERSTORMS INTO TONIGHT GIVEN THE AMOUNT OF INSTABILITY AND SHEAR AVAILABLE. CURRENT N/S SQUALL LINE CENTRAL AL/WRN FL PANHANDLE WITH EMBEDDED SUPERCELLS AND ISOLATED TORNADOES SUPPORTED BY 60-70KT OF DEEP LAYER SHEAR/30-35KT OF SFC TO 1KM SHEAR AND HELICITIES FROM 250-300 M2/S2. SQUALL LINE EXPECTED TO ENTER WRN GA BY 14Z AND LIKELY REMAIN THE PRIMARY FOCUS FOR TODAYS SEVERE POTENTIAL. SFC HEATING ACROSS GA INTO SC AHEAD OF SQUALL LINE ALONG WITH DEWPOINTS IN THE 60S WILL ALLOW MLCAPES TO CLIMB TO 1000 J/KG OR GREATER. WIND DAMAGE WILL BE THE PRIMARY CONCERN WITH THE SQUALL LINE WITH SOME POTENTIAL FOR MORE ISOLATED SEVERE STORM DEVELOPMENT IN THE WARM SECTOR. A CONTINUED SMALL TORNADO THREAT WILL EXTEND EWD INTO SRN SC THIS EVENING AS SHEAR OF 40-50 KTS WILL MAINTAIN SUPERCELL POTENTIAL ALONG/AHEAD OF SQUALL LINE. HAVE MAINTAINED A MORE CONDITIONAL RISK AS FAR E AS ERN NC OVERNIGHT. WHILE TROUGH WILL CONTINUE TO WEAKEN PRESENCE OF 60 PLUS DEWPOINTS AND 35-40KT OF DEEP LAYER SHEAR WILL PROVIDE SUFFICIENT SUPPORT FOR CONTINUATION OF SQUALL LINE AND AT LEAST A WIND DAMAGE THREAT. GFS IN PARTICULAR INDICATES A STRONG CONVECTIVE SIGNAL EWD ACROSS NRN FL THIS AFTN/EVE. VERY MOIST AND MDTLY UNSTABLE AIRMASS WITH DEWPOINTS NEAR 70F THIS AREA COUPLED WITH SFC TEMPS NEAR 80F BY AFTERNOON RESULTS IN MLCAPES TO 1500 J/KG. COUPLED WITH MDT SHEAR...SEVERE POTENTIAL INCLUDING ISOLATED TORNADOES ARE EXPECTED NRN FL EVEN WITH THE ANTICIPATED WEAKENING OF THE UPPER TROUGH BY THIS EVENING. ..HALES.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 16:27:47 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 11:27:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051631 SWODY1 SPC AC 051629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST FRI JAN 05 2007 VALID 051630Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN STATES... ...SYNOPSIS... COMPACT...BUT INTENSE SHORTWAVE TROUGH WAS LOCATED OVER CENTRAL MS AT MID MORNING AND IS EXPECTED TO SLOWLY WEAKEN AS IT EJECTS NEWD INTO THE CAROLINAS TONIGHT...IN RESPONSE TO DEEPENING LONGWAVE TROUGH IN THE WEST. PREVIOUS MODEL RUNS HAVE WEAKENED SYSTEM TOO FAST AND THIS COULD BE THE CASE AGAIN GIVEN LATEST WATER VAPOR TRENDS AND RELATIVELY WEAKEN CONFLUENCE ALOFT AHEAD OF THE SYSTEM. ...SERN STATES... A SQUALL LINE WAS MOVING EWD AT 35-40 KT THROUGH WRN GA/SERN AL AND THE WRN FL PANHANDLE...AND SHOULD BEGIN TO ACCELERATE THIS AFTERNOON/EVENING AS THE UPPER TROUGH BEGINS TO LIFT NEWD MORE RAPIDLY. AN UNSEASONABLY WARM AND MOIST AIR MASS...MID 60 DEWPOINTS ...WAS SPREADING NWD IN ADVANCE OF THE SQUALL LINE INTO THE CAROLINAS. TEMPERATURES ARE EXPECTED TO WARM AT LEAST INTO THE LOWER TO MID 70S AND YIELD MLCAPE VALUES FROM 500 TO 1000 J/KG EAST OF THE SQUALL LINE. DEEP LAYER SHEAR AT 50-60 KT WILL BE SUPPORTIVE OF SUPERCELLS WITHIN AND AHEAD OF THE LINE. THE MOIST BOUNDARY LAYER COMBINED WITH 1 KM SHEAR OF 20 TO 30 KT WILL FAVOR THE DEVELOPMENT OF TORNADOES. ALSO...DRYING BETWEEN 925-800 MB...AND EVIDENT AT HIGH LEVELS ON WATER VAPOR IMAGERY...IS EXPECTED TO SUPPORT A WIND DAMAGE THREAT ALONG THE EWD MOVING SQUALL LINE. ALTHOUGH THE UPPER SYSTEM SHOULD WEAKEN SOME TONIGHT...THE STRENGTH OF THE SHEAR/INSTABILITY IS EXPECTED TO MAINTAIN A SUPERCELL POTENTIAL AN ACTIVE SQUALL LINE INTO THE ERN CAROLINAS. THE PRESENCE OF THE APPROACHING SHORTWAVE TROUGH...DEEP LAYER SHEAR AT 45-50 KT AND 1 KM SHEAR AT 20-30 KT INDICATES THE THREAT FOR WIND DAMAGE AND TORNADOES SHOULD CONTINUE INTO TONIGHT. ..IMY.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 19:58:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 14:58:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 052001 SWODY1 SPC AC 051959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0159 PM CST FRI JAN 05 2007 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SERN STATES... ...SERN STATES... WATER VAPOR IMAGERY CONTINUES TO SHOW A VIGOROUS MID-LEVEL SHORTWAVE TROUGH EJECTING NEWD ACROSS MS/AL. STRONG ASCENT AHEAD OF THIS FEATURE WAS SUPPORTING A LINEAR MCS FROM UPSTATE SC SWD INTO THE NERN GULF OF MEXICO. THE LINE...AND DISCRETE CELLS AHEAD OF THE LINE...HAVE BEEN INCREASING SINCE 18Z. THIS UPSWING IN INTENSITY MAY BE INDICATIVE OF STRONGER HEIGHT FALLS BEGINNING TO SWING NEWD INTO THE FL PNHDL/SWRN GA AT MID-AFTN. IN FACT...18Z MESOANALYSIS PLACED A PRESSURE FALL AXIS FROM NRN FL INTO SERN GA AND SUGGESTED THAT THE ENVIRONMENT WAS BECOMING SUPPORTIVE FOR ANOTHER ROUND OF ORGANIZED TSTMS. INVERSION NOTED JUST BELOW 750 MB IN THE 18Z CHS SOUNDING WILL LIKELY BE ERODED AS THE STRONGER UVVS SPREAD NEWD. BOUNDARY LAYER HAS BECOME UNSTABLE AS TEMPERATURES/DEW POINTS HAVE RISEN INTO THE MID 70S/MID 60S RESPECTIVELY. AS THE MID-LEVELS COOL...THE COLUMN WILL SUPPORT VIGOROUS UPDRAFTS. AS A RESULT...THE LINE OF STORMS ACROSS ECNTRL GA TO THE NERN GULF OF MEXICO WILL LIKELY REMAIN STRONG AS IT SWEEPS ENEWD INTO PARTS OF NC/SC...SERN GA AND NRN FL THROUGH TONIGHT. THE UPPER SYSTEM HAS NOT WEAKENED AS SUGGESTED BY PREVIOUS MODELS. AS A RESULT...MID-LEVEL WINDS HAVE REMAINED QUITE STRONG AND DEEP LAYER SHEAR IN EXCESS OF 50 KTS WILL BE SLOW TO WEAKEN THIS EVENING. THIS WILL SUPPORT SUPERCELL STRUCTURES...BOTH AHEAD OF AND EMBEDDED WITHIN THE LINEAR MCS. SMALL SCALE BOWS WILL BE CAPABLE OF DAMAGING WIND GUSTS. ADDITIONALLY...ISOLD TORNADOES WILL BE POSSIBLE...ESPECIALLY OVER SERN GA AND PARTS OF SC WHERE THE LOW-LEVEL FLOW REMAINS SOMEWHAT BACKED VCNTY THE STRONGER PRESSURE FALLS. ..RACY.. 01/05/2007  From swody1 at goshenarc.org Sat Jan 6 00:58:46 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 19:58:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060102 SWODY1 SPC AC 060100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 PM CST FRI JAN 05 2007 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NRN FL THROUGH THE ERN CAROLINAS AND SERN VA... ...NRN FL THROUGH SERN GA...THE ERN CAROLINAS AND SERN VA... THE SHORTWAVE TROUGH CENTERED OVER GA WILL CONTINUE NE THROUGH THE CAROLINAS TONIGHT AND OFFSHORE EARLY SATURDAY...DEAMPLIFYING IN THE PROCESS. LOW LEVEL JET SHOULD STRENGTHEN TO 50+ KT ACROSS THE ERN CAROLINAS INTO ERN VA WITHIN REGION OF HEIGHT FALLS DOWNSTREAM FROM THE SHORTWAVE TROUGH. LATEST OBJECTIVE ANALYSIS SHOW MLCAPE FROM 500 TO 1000 J/KG OVER THE ERN CAROLINAS. BAND OF PRE-FRONTAL STORMS FROM S CNTRL NC SWD THROUGH SERN GA AND NRN FL WILL PERSIST NEXT SEVERAL HOURS ALONG WARM CONVEYOR BELT AND WITHIN ZONE OF DPVA/ASCENT ACCOMPANYING THE SHORTWAVE TROUGH. THIS ACTIVITY WILL SHIFT ENEWD OVERNIGHT. STORMS OVER NRN FL MAY GRADUALLY DECREASE LATER THIS EVENING AS THE LOW LEVEL JET AND STRONGER FORCING FOR ASCENT LIFT AWAY FROM THIS REGION. HOWEVER...THE STRENGTHENING LOW LEVEL JET OVER THE CAROLINAS INTO SERN VA SHOULD ENHANCE STORM RELATIVE INFLOW AND MAINTAIN FAVORABLE HODOGRAPHS FOR LOW LEVEL MESOCYCLONES. THEREFORE...THREAT FOR ISOLATED DAMAGING WIND AND ISOLATED TORNADOES IN THIS REGION MAY PERSIST THE REMAINDER OF THIS EVENING INTO THE EARLY MORNING. PRIMARY LIMING FACTORS WILL BE TENDENCY ..DIAL.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 05:39:06 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 00:39:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060543 SWODY1 SPC AC 060540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...GULF COASTAL STATES... POSITIVELY TILTED UPPER TROUGH WILL CONTINUE EWD THROUGH THE SRN PLAINS AND LOWER MS VALLEY SATURDAY AND SATURDAY NIGHT. COLD FRONT CURRENTLY FROM THE GREAT LAKES SWWD THROUGH SWRN TX WILL MOVE EAST AND EXTEND FROM THE NERN STATES SWWD THROUGH THE NWRN GULF BY EARLY SATURDAY EVENING. WEAK SURFACE WAVE IS FORECAST TO DEVELOP ALONG FRONT OVER THE NWRN GULF BY SATURDAY NIGHT WITHIN UPPER JET ENTRANCE REGION AND ZONE OF HEIGHT FALLS ATTENDING THE SHORTWAVE TROUGH. AS THIS OCCURS THE LOW LEVEL JET WILL STRENGTHEN OVER THE GULF AND INTO THE SERN STATES. THUNDERSTORMS SHOULD DEVELOP WITHIN ZONE OF INCREASING THETA-E ADVECTION AND ISENTROPIC ASCENT IN VICINITY OF AND N OF FRONTAL BOUNDARY OVER THE GULF COASTAL AREA SATURDAY NIGHT. WEAK INSTABILITY AND POOR LAPSE RATES WILL LIMIT ANY SEVERE POTENTIAL. OTHER ELEVATED CONVECTION MAY DEVELOP WITHIN ZONE OF FRONTOGENETIC FORCING ON COOL SIDE OF SURFACE FRONT FROM ERN TX INTO THE LOWER MS VALLEY. HOWEVER...FORECAST SOUNDING WITH POOR MID LEVEL LAPSE RATES SHOW VERY LITTLE INSTABILITY IN LAYERS ABOVE -5C...SUGGESTING ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED WITH THIS ACTIVITY. ...SRN NEW ENGLAND... ISOLATED LIGHTING STRIKES MAY ACCOMPANY PRE-FRONTAL CONVECTION SATURDAY MORNING BEFORE MOVING OFFSHORE WITH FRONTAL PASSAGE BY AFTERNOON. ..DIAL.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 12:42:42 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 07:42:42 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061246 SWODY1 SPC AC 061244 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 AM CST SAT JAN 06 2007 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... STRONG WESTERLIES ACROSS MUCH OF CONUS CURRENTLY WILL GAIN AMPLITUDE AS STRONG PAC NW S/WV DEEPENS OVER THE PLAINS BY THE END OF THE FORECAST PERIOD. ALL CONVECTION NOW OFFSHORE MID ATLANTIC COAST AS WEAKENING SYSTEM CONTINUES EWD INTO WRN ATLANTIC. AN UNSEASONABLY WARM...MOIST AIR MASS CURRENTLY OVER NERN STATES AHEAD OF WEAK SURFACE SYSTEM/UPPER TROUGH MOVING THRU THE ERN GREAT LAKES. SOME WEAK CONVECTION/ISOLATED LIGHTNING STRIKES POSSIBLE AS 12Z SOUNDINGS FROM BUF TO CHH INDICATE SOME MEAGER CAPE. HOWEVER ANY CONVECTIVE THREAT SHOULD DIMINISH FROM W TO E THIS AFTERNOON. PRIMARY SURFACE FRONTAL ZONE EXTENDS WWD ACROSS NRN FL AND NRN GULF OF MEXICO. WITH TROUGH DEEPENING INTO PLAINS TONIGHT PRESSURE WILL FALL OVER THE LOWER MS VALLEY LEADING TO GRADUAL NWD MOVEMENT OF FRONTAL ZONE ONSHORE CENTRAL GULF COAST. LOW LEVEL JET WILL BACK AND INCREASE TONIGHT WITH A DEVELOPING ZONE OF THETA-E ADVECTION...ALONG AND N OF RETURNING FRONTAL BOUNDARY. LAPSE RATES ARE FORECAST TO BE WEAK...GENERALLY LESS THAN 6C/KM VICINITY AND N OF GULF FRONT WHICH WILL PRECLUDE DEVELOPMENT OF ANY APPRECIABLE INSTABILITY. OVERNIGHT THUNDERSTORMS WILL BECOME INCREASINGLY LIKELY WITHIN THE ZONE OF STRONGEST ASCENT N OF WARM FRONT...BUT SEVERE POTENTIAL IS NON-EXISTENT THRU 12Z SUNDAY. ..HALES.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 16:18:45 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 11:18:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061622 SWODY1 SPC AC 061620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST SAT JAN 06 2007 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... LONGWAVE TROUGH...LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY ...WILL AMPLIFY BY THE END OF THE PERIOD AS A STRONG SHORTWAVE TROUGH AND ASSOCIATED 90-100 KT MID LEVEL JET DIVES SEWD FROM THE PACIFIC NW INTO THE CENTRAL PLAINS. SURFACE FRONT EXTENDS FROM SRN TX EWD ACROSS THE FAR NRN GULF OF MEXICO AND INTO THE FL PANHANDLE. A WEAK INVERTED TROUGH WAS LOCATED ALONG THE FRONT ACROSS FAR SRN TX. THIS FEATURE IS FORECAST TO SLOWLY STRENGTHEN AND SHIFT NEWD ACROSS THE WRN GULF AND INTO THE LOWER MS VALLEY BY 12Z SUNDAY...AS THE UPPER TROUGH DEEPENS OVER THE CENTRAL U.S. ...LOWER MS VALLEY REGION... SATELLITE IMAGERY SHOWED SHALLOW CONVECTION WAS LOCATED NORTH OF THE FRONT NEAR THE GULF COAST IN RESPONSE TO WEAK WARM ADVECTION. AS THE LOW LEVEL JET STRENGTHENS LATER TODAY AND TONIGHT... INCREASING THETA-E ADVECTION NORTH OF THE BOUNDARY SHOULD RESULT IN WIDESPREAD RAIN AND A FEW THUNDERSTORMS TO DEVELOP. AS THE SURFACE LOW AND WARM FRONT MOVE INLAND...UPPER 60S DEWPOINTS ARE LIKELY TO SHIFT NWD INTO SRN LA. WIND PROFILES WILL BE RELATIVELY STRONG AND RESULT IN 40-50 KT OF DEEP LAYER SHEAR. HOWEVER...DESPITE THE RETURN OF A MOIST BOUNDARY LAYER...INSTABILITY WILL BE WEAK DUE TO WEAK LAPSE RATES ALOFT. ALSO...RELATIVELY WARM TEMPERATURES BETWEEN 450 AND 500 MB ARE EXPECTED TO LIMIT STRONG UPDRAFTS AND THE SEVERE POTENTIAL. ...ERN NY AND SRN NEW ENGLAND... LIGHTNING HAS REMAINED OFFSHORE THROUGH THE MORNING...DESPITE WEAK ELEVATED INSTABILITY INDICATED ON MORNING SOUNDINGS. CONVECTION WAS LOCATED ALONG COLD FRONT MOVING THROUGH CENTRAL NY...AND THIS SYSTEM WILL SWEEP RAPIDLY EWD THROUGH THE AFTERNOON. THE CONVECTION ALONG THE FRONT MAY BECOME DEEP ENOUGH FOR LIGHTNING AS SURFACE TEMPERATURES WARM INTO THE MID 60S AND HEIGHTS FALL ACROSS THE REGION...IN RESPONSE TO AN UPPER TROUGH MOVING EWD THROUGH ONTARIO/QUEBEC. ..IMY.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 19:52:48 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 14:52:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061956 SWODY1 SPC AC 061954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST SAT JAN 06 2007 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/NRN NEW ENGLAND THROUGH EARLY EVENING... CYCLONIC FLOW ALOFT CARRYING SEVERAL DISTURBANCES ALONG THE INTERNATIONAL BORDER HAS BEEN IMPETUS FOR FAST MOVING LOW-TOPPED CONVECTION ACROSS CNTRL/NRN NEW ENGLAND THIS AFTN. STRONGEST CELLS...INCLUDING SPORADIC LIGHTNING...WERE FOCUSED ALONG A COLD FRONT THAT WILL MOVE EWD THROUGH THE REMAINDER OF NEW ENGLAND THIS EVENING. THE MOST UNSTABLE ENVIRONMENT WILL REMAIN OVER PARTS OF CNTRL/SRN NH...SRN VT AND NRN MA WHERE A SEASONABLY MOIST/WARM BOUNDARY LAYER EXISTS. HERE...GUSTY WINDS WILL LIKELY ACCOMPANY THE STRONGER TSTMS GIVEN THE 50-55 KT WLY WINDS NOTED IN THE LOWEST 1KM /BURLINGTON /CCX/ VWP/. FARTHER E...THE BOUNDARY LAYER HAS NOT RECOVERED AS MUCH AND CONVECTION WILL LIKELY BECOME MORE ELEVATED WITH TIME...THOUGH STILL CAPABLE OF ISOLD LIGHTNING. ...GULF COASTAL REGION TONIGHT... WEAK WARM ADVECTION ALONG/N OF THE BAROCLINIC ZONE ALONG THE GULF COAST CONTINUES TO SUPPORT SHALLOW CONVECTION. SATL SHOWS EVIDENCE OF A SUB-SYNOPTIC CYCLONIC CIRCULATION MOVING OVER SRN TX WITH GENERAL NLY FLOW IN THE BOUNDARY LAYER OVER SE TX. AS THE UPSTREAM TROUGH CONTINUES TO DIG SEWD THROUGH THE CNTRL ROCKIES THIS EVE AND ONTO THE CNTRL PLAINS TONIGHT...THIS CIRCULATION MAY INTENSIFY AND DEVELOP NEWD TOWARD SRN LA. TO THE E OF THIS FEATURE...THE LLJ WILL BEGIN TO ACCELERATE...ENHANCING LOW- AND MID-LEVEL THETA-E ADVECTION ACROSS THE LWR MS VLY INTO THE ERN GULF COASTAL AREA. AS A RESULT...CONVECTION/TSTMS WILL BE ON THE INCREASE OVERNIGHT. THOUGH THE BOUNDARY LAYER WILL MOISTEN QUICKLY TONIGHT ALONG THE GULF COAST AND THERE WILL BE 40-50 KTS OF EFFECTIVE SHEAR...THE THERMAL BUOYANCY SHOULD REMAIN WEAK GIVEN THE WARM TEMPERATURES IN THE MID-LAYERS OF THE TROPOSPHERE. THE RESULT WILL BE WEAK UPDRAFTS AND LIMITED SEVERE POTENTIAL. ..RACY.. 01/06/2007  From swody1 at goshenarc.org Sun Jan 7 00:50:17 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 19:50:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070054 SWODY1 SPC AC 070051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0651 PM CST SAT JAN 06 2007 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... LATEST WATER VAPOR IMAGERY SHOWS A DEVELOPING GREAT PLAINS UPPER-LEVEL TROUGH WITH SWLY FLOW IN PLACE ACROSS THE SRN AND ERN UNITED STATES. AS A GREAT PLAINS UPPER-LEVEL TROUGH DEEPENS TONIGHT...A 40-50 KT LOW-LEVEL JET WILL DEVELOP IN CNTRL MS. IN RESPONSE...A NEARLY STATIONARY FRONT LOCATED IN SRN MS AND CNTRL AL WILL LIFT NWD AS A WARM FRONT INCREASING LOW-LEVEL MOISTURE FROM SOUTH TO NORTH ACROSS THE REGION. THE STRONG ISENTROPIC ASCENT ASSOCIATED WITH THE LOW-LEVEL JET AND INCREASING LOW-LEVEL MOISTURE SHOULD HELP INITIATE SCATTERED THUNDERSTORMS LATE TONIGHT. DUE TO AN INVERSION NEAR THE SFC...THE ACTIVITY SHOULD REMAIN ELEVATED. ALTHOUGH SHEAR PROFILES WILL BE STRONG...FORECAST SOUNDINGS SHOW VERY LITTLE INSTABILITY WHICH SHOULD LIMIT THE SEVERE POTENTIAL. ELSEWHERE ACROSS THE CONUS THUNDERSTORM ACTIVITY IS NOT EXPECTED TONIGHT. ..BROYLES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 05:43:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 00:43:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070547 SWODY1 SPC AC 070545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1145 PM CST SAT JAN 06 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NC...SC AND SE VA... ...CAROLINAS AND SERN VIRGINIA... A SYNOPTIC-SCALE UPPER-LEVEL TROUGH WILL DEEPEN OVER THE CNTRL UNITED STATES TODAY AND MOVE EWD INTO THE MS VALLEY. IN RESPONSE...A SFC LOW IS FORECAST TO ORGANIZE OVER THE SERN U.S. AND MOVE NEWD INTO THE SRN APPALACHIAN MTNS THIS AFTERNOON. A STRONG LOW-LEVEL JET WILL INCREASE IN STRENGTH AND SIZE AS LOW-LEVEL MOISTURE IS BROUGHT NWD ACROSS THE CAROLINAS. THE INCREASING MOISTURE AND STRONG LARGE-SCALE ASCENT SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS IN THE CAROLINAS BY AFTERNOON. THE STORMS SHOULD MOVE QUICKLY NEWD ACROSS NC BY EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS AFTERNOON SHOW IMPRESSIVE SHEAR PROFILES WITH BACKED SELY SFC WINDS AND 50 KT OF FLOW AT 850 MB. THE LARGE HODOGRAPHS COMBINED WITH STRONG VERTICAL SHEAR SHOULD BE SUFFICIENT FOR LOW-TOPPED SUPERCELLS CAPABLE OF PRODUCING A TORNADO OR TWO. THE TORNADO THREAT SHOULD REMAIN ISOLATED DUE TO WEAK INSTABILITY AS STORMS DEVELOP NEWD ACROSS THE CAROLINAS LATE THIS AFTERNOON INTO THE EVENING. ALSO...AN ISOLATED WIND DAMAGE THREAT MAY OCCUR WITH THE BETTER ORGANIZED THUNDERSTORMS. THE SEVERE THREAT SHOULD EXPAND NEWD DURING THE EVENING POSSIBLY AFFECTING AREAS AS FAR NORTH AS SE VA. ..BROYLES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 12:33:06 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 07:33:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071236 SWODY1 SPC AC 071234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 AM CST SUN JAN 07 2007 VALID 071300Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF AL/NRN GA ENEWD TO MID ATLANTIC STATES... AS IS FREQUENTLY THE CASE IN COOL SEASON SEVERE THREAT PATTERNS IN THE SOUTHEAST...THE ONLY CAVEAT SEPARATING AN ACTIVE STORM DAY FROM A NO SEVERE DAY IS AIR MASS BUOYANCY/INSTABILITY. CURRENT SITUATION IS TYPICAL AS A VERY STRONG TROUGH AND ASSOCIATED JET STRUCTURE RAPIDLY SWINGS EWD ACROSS THE PLAINS TO THE TN/OH VALLEYS BY 12Z MON. IN THE WAKE OF THE PREVIOUS SYSTEM THE AIR MASS OVER THE GULF WAS UNDISTURBED AND OVERNIGHT THERE HAS BEEN A DRAMATIC NWD RETURN OF MOISTURE ALONG THE GULF COAST AS PRECIPITABLE WATER HAS RISEN TO ABOVE 1.5 INCHES. WHILE THERE HAS BEEN A STEADY INCREASE IN CONVECTIVE TYPE PRECIPITATION OVERNIGHT ACROSS THE GULF STATES IN THE STRENGTHENING ISENTROPIC/WARM ADVECTION REGIME...THE WEAK LAPSE RATES HAVE LIMITED THE BUOYANCY WITH LITTLE LIGHTNING NOTED THUS FAR. SURFACE LOW HAS DEVELOPED IN RESPONSE TO THE APPROACH OF THE STRONG UPPER TROUGH AND WILL GRADUALLY DEEPEN FROM ITS CURRENT LOCATION OVER WCENTRAL MS NEWD ACROSS MIDDLE TN TO WRN PA BY 12Z MON. LOW/MID LEVEL JET ACROSS DEVELOPING WARM SECTOR AL/GA WILL INCREASE TO 50-60KT AS 100PLUS KT 500 MB POLAR JET SHIFTS EWD INTO TN/OH VALLEYS BY THIS EVENING. SHEAR PROFILES WILL BE VERY SUPPORTIVE OF ROTATING STORMS WITH SFC-1KM SHEAR INCREASING TO 40KT OR GREATER THIS AFTERNOON AND TONIGHT. MID 60 F DEWPOINTS WILL SPREAD INLAND BY THIS AFTERNOON AS FAR N AS CENTRAL AL/NRN GA AND ERN CAROLINAS. EVEN THOUGH THE WEAK LAPSE RATES AND MINIMAL DAYTIME HEATING WILL GENERALLY LIMIT MLCAPES TO 500 J/KG...THE STRENGTH OF THE SYSTEM COUPLED WITH THE UNSEASONABLY MOIST AIRMASS REQUIRES AN EXPANSION OF THE PRIMARILY CONDITIONAL SEVERE RISK AREA WWD INTO AL. LOW TOPPED SUPERCELLS WILL BECOME AN INCREASING CONCERN BY EARLY/MID AFTERNOON CENTRAL AL/GA SPREADING NEWD INTO CAROLINAS TONIGHT IN THE DEVELOPING WARM SECTOR. ADDITIONALLY MORE SYNOPTICALLY FORCED LINE SEGMENTS WILL DEVELOP ALONG/AHEAD OF COLD FRONT NOW NOTED FROM THE SURFACE LOW SWWD TO SWRN LA. A TORNADO THREAT WILL BE ASSOCIATED WITH THE DISCRETE SUPERCELLS THAT CAN DEVELOP IN THE WARM SECTOR AND POSSIBLY EMBEDDED IN THE MORE LINER ACTIVITY VICINITY COLD FRONT. ADDITIONALLY WIND DAMAGE WILL EXIST WITH SAME ACTIVITY GIVEN THE INTENSITY OF THE WIND FIELDS ALOFT. THIS THREAT OF ISOLATED TORNADOES/WIND DAMAGE WILL CONTINUE NEWD OVERNIGHT THRU THE MID ATLANTIC STATES AS THE SYSTEM SURFACE AND ALOFT INTENSIFIES FURTHER. ..HALES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 16:30:40 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 11:30:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071634 SWODY1 SPC AC 071632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SUN JAN 07 2007 VALID 071630Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS THE SRN GULF STATES...AND LATER THIS AFTERNOON AND TONIGHT ACROSS PARTS OF THE CAROLINAS.... ...SYNOPSIS... LATEST WATER VAPOR SATELLITE IMAGERY SHOWS MID/UPPER LEVEL SHORTWAVE TROUGH/ASSOCIATED VORTICITY MAX IS OVER SRN IL EXTENDING SSWWD INTO SERN TX. THIS FEATURE IS LOCATED JUST AHEAD OF MAIN TROUGH OVER THE ERN NRN PLAINS EXTENDING SSWWD THROUGH W TX. 15Z SURFACE ANALYSIS HAS LOW PRESSURE OVER NERN MS/SWRN TN WITH A COLD FRONT EXTENDING THROUGH S CENTRAL LA...AND A QUASISTATIONARY FRONT THAT REACHES SEWD INTO CENTRAL GA BEFORE CURVING ENEWD ACROSS SERN SC. IT SEEMS THAT THE FOCUS FOR SEVERE ACTIVITY TODAY AND TONIGHT WILL BE THE COLD FRONT AS IT MOVES EWD/NEWD AS THE LOW TRAVELS THROUGH MIDDLE TN THIS AFTERNOON INTO WRN UPSTATE NEW YORK TONIGHT. ...PARTS OF ERN MS INTO SWRN GA... LATEST VISIBLE SATELLITE IMAGERY SHOWS CONSIDERABLE CLOUD COVER ACROSS MUCH OF THE GULF STATES WITH A FEW BREAKS OVER SERN MS INTO SWRN GA. STRONG FORCING IS EXPECTED TO OCCUR AS THE COLD FRONT MOVES EWD THIS AFTERNOON JUST AHEAD OF SECOND STRONGER TROUGH MOVING OVER THE SRN HALF OF THE MS VALLEY REGION DURING THE LATTER HALF OF THE PERIOD. EXPECT THAT AN INCREASE IN INTENSITY WILL OCCUR WITH CURRENT BAND OF SHOWERS/THUNDERSTORMS THAT EXTENDS FROM NWRN LA SWWD INTO S CENTRAL LA AS THEY MOVE INTO AL EARLY THIS AFTERNOON. DEEP LAYER SHEAR WILL BECOME MORE ENHANCED IN ASSOCIATION WITH REAR ENTRANCE REGION OF STRONG 300 MB JET /130-160 KT/ COUPLED WITH SSWLY 30-50 KT LOW LEVEL JET. MAIN THREAT WILL BE DAMAGING WINDS WITH THIS ACTIVITY. ...PARTS OF THE CAROLINAS INTO SERN VA... MAIN CONCERN AT THIS TIME IS HOW THE QUASISTATIONARY BOUNDARY /MAINLY DUE TO COLD AIR DAMMING ON THE LEE SIDE OF THE APPALACHIANS/ WILL PLAY A ROLE LATER THIS AFTERNOON AND TONIGHT. ATTENTION NEEDS TO BE GIVEN TO STRONG LOW LEVEL JET OF 50-60 KT AHEAD OF THE MAIN TROUGH THAT WILL EXTEND FROM SWRN GA INTO CENTRAL NC BY 08/00Z. MODELS INDICATE STRONG LOW LEVEL WARM ADVECTION AND ENHANCED UVVS ACROSS THE CAROLINAS...AND FEEL THAT IF THERE IS ANY SUPERCELL THREAT IT WILL BE WITH THE BOUNDARY AS IT BECOMES A WARM FRONT AND MOVES NWD INTO CENTRAL/NRN NC THIS EVENING. ONCE AGAIN... INSTABILITY WILL REMAIN VERY LIMITED WITH MUCAPE STRUGGLING TO BE AROUND 500 J/KG...BUT VERTICAL SHEAR PROFILES/STORM RELATIVE HELICITY VALUES ARE FORECAST TO BE 300-500 M2/S2 JUST SOUTH OF THE BOUNDARY AND HIGHER JUST NORTH OF IT. THUS...EXPECT COMPARATIVELY DISCRETE LOW-TOPPED SUPERCELLS TO DEVELOP AHEAD OF THE MAIN FRONTAL BOUNDARY THIS EVENING AND TONIGHT ACROSS PARTS OF THE CAROLINAS WITH THE MAIN THREAT BEING ISOLATED TORNADOES THIS EVENING...WITH MORE WIDESPREAD DAMAGING WINDS ASSOCIATED WITH THE COLD FRONT LATER TONIGHT AND TOWARDS THE END OF THE PERIOD. ..MCCARTHY.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 19:32:25 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 14:32:25 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071936 SWODY1 SPC AC 071934 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0134 PM CST SUN JAN 07 2007 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE DEEP SOUTH INTO THE SERN STATES/SERN MID-ATLANTIC REGIONS... ...SERN STATES... A WEAK LEAD SHORTWAVE TROUGH CONTINUES TO SHEAR ENEWD ACROSS THE TN VLY THIS AFTN AND IS LIKELY CONTRIBUTING TO THE RECENT INCREASE IN CONVECTION/TSTMS FROM ERN TN SWWD INTO WCNTRL AL. A MORE ROBUST IMPULSE WAS QUICKLY MOVING SEWD THROUGH THE CNTRL/SRN PLAINS AND WILL BECOME NEGATIVELY TILTED AS IT BEGINS TO EJECT EWD ACROSS THE OH/TN VLYS LATER TONIGHT. 18Z SFC ANALYSIS SHOWS A 1010 MB LOW OVER SCNTRL KY WITH A WARM FRONT REDEVELOPING NWD ALONG THE SRN EDGE OF THE APPALACHIANS. A VERY WARM AND MOIST BOUNDARY LAYER WAS FLOODING NWD AHEAD OF A COLD FRONT SITUATED FROM THE LOW SWD ACROSS NWRN AL TO WEST OF THE NEW ORLEANS AREA. 18Z BMX SOUNDING EXHIBITED AROUND 185 J/KG MLCAPES WITH RATHER POOR LAPSE RATES. THIS WAS RESULTING IN AN ENVIRONMENT SUPPORTIVE OF A GRADUAL DEEPENING/STRENGTHENING OF MOIST CONVECTION AMIDST WEAK LARGE SCALE FORCING. AS THE UPSTREAM PLAINS TROUGH SWINGS EWD TONIGHT AND MID-UPPER LEVEL JET MAX ACCELERATES...FORCING FOR ASCENT WILL INCREASE THROUGH A DEEPER LAYER AND CONVECTION SHOULD FURTHER STRENGTHEN ALONG/AHEAD OF THE SEWD MOVING COLD FRONT OVERNIGHT. THE COINCIDENT INCREASE IN LOW-LEVEL FLOW WILL RESULT IN AN EROSION OF THE WEDGE FRONT AND RAPID MOISTENING OF THE COLUMN DOWNSTREAM ACROSS THE SRN APPALACHIANS AND THE CAROLINAS...SERN VA BY 12Z. GIVEN THAT THE PRIMARY SFC LOW SHOULD REMAIN WEST OF THE APPALACHIAN SPINE...STRONGEST VEERING WITH HEIGHT OF THE WIND FIELD SHOULD EXIST ALONG THE WARM FRONT AS IT LIFTS NWD WITH TIME THIS EVENING/OVERNIGHT. HOWEVER...STRONG SPEED SHEAR SHOULD CONTINUE OWING TO THE INCREASING LOW- AND MID-LEVEL WIND FIELDS OVERNIGHT ACROSS THE WARM SECTOR. AS A RESULT OF THE DESTABILIZATION... INCREASED FORCING AND THE FAVORABLE VERTICAL SHEAR...ANY SUSTAINED TSTM COULD BECOME SUPERCELLULAR...EITHER EMBEDDED WITHIN THE LINEAR MCS OR AHEAD OF IT. MAIN THREAT WILL BE DAMAGING WINDS...ALTHOUGH BRIEF TORNADOES COULD ALSO OCCUR. MAIN SEVERE WEATHER THREATS WILL OCCUR ACROSS PORTIONS OF THE DEEP S INTO WRN GA THIS EVENING...SHIFTING EWD WITH TIME INTO PARTS OF THE CAROLINAS AND SERN VA BY 12Z MONDAY. ..RACY.. 01/07/2007  From swody1 at goshenarc.org Mon Jan 8 00:44:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 19:44:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080047 SWODY1 SPC AC 080045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 PM CST SUN JAN 07 2007 VALID 080100Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SE AL...GA...SC AND NC... ...SE AL/GA/SC/SRN AND ERN NC... WATER VAPOR IMAGERY CURRENTLY SHOWS A SYNOPTIC SCALE UPPER-LEVEL TROUGH LOCATED ACROSS THE PLAINS AND MID MS VALLEY. AHEAD OF THE TROUGH...A BAND OF MID-LEVEL MOISTURE EXTENDS FROM THE WRN GULF OF MEXICO NEWD ACROSS THE SERN UNITED STATES. THIS MOISTURE IS CO-LOCATED WITH THE STRONGER LARGE-SCALE ASCENT ASSOCIATED WITH THE TROUGH AND IS SUPPORTING A WELL-DEVELOPED CONVECTIVE LINE FROM THE WRN FL PANHANDLE NEWD INTO NRN GA. THE LINE IS LOCATED AHEAD OF A COLD FRONT WITH MID 60 F SFC DEWPOINTS PRESENT ACROSS MOST OF GA...SC AND SRN NC. THIS SHOULD SUSTAIN THE LINE OF THUNDERSTORMS WITH THE STRONGER CONVECTION MOVING ENEWD ACROSS SC INTO SERN NC OVERNIGHT. LATEST OBJECTIVE ANALYSIS SHOWS A 100 KT MID-LEVEL JET EXTENDING NEWD FROM THE LOWER MS VALLEY NEWD INTO THE OH VALLEY. THE MID-LEVEL JET IS BROAD AND 50 KT OF FLOW EXISTS ACROSS MOST OF GA...SC AND NC ATTM. ALTHOUGH INSTABILITY WILL REMAIN WEAK ACROSS THE REGION TONIGHT...THE STRONG VERTICAL SHEAR SHOULD CONTINUE TO SUPPORT AN ISOLATED SEVERE THREAT WITH THE LINE. WIND DAMAGE WOULD BE THE PRIMARY THREAT ALTHOUGH A TORNADO CAN NOT BE RULED OUT. AS THE LINE APPROACHES HIGHER SFC DEWPOINTS ACROSS ERN SC AND ERN NC...REDEVELOPMENT OR ENHANCEMENT OF THE LINE MAY OCCUR LATE TONIGHT. ..BROYLES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 05:33:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 00:33:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080536 SWODY1 SPC AC 080534 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 PM CST SUN JAN 07 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...ERN SEABOARD... A LARGE-SCALE TROUGH WILL DOMINATE THE ERN U.S. AS A COLD FRONT MOVES EWD ACROSS THE ERN SEABOARD. A LINE OF CONVECTION SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD WITH THUNDERSTORMS EMBEDDED IN THE LINE. MODEL FORECASTS DESTABILIZE THE AIRMASS ALONG THE IMMEDIATE COAST OF NC THIS MORNING WHICH MAY BE ENOUGH FOR A MARGINAL SEVERE THREAT ACROSS ERN NC AND ERN VA. ALTHOUGH STRONG GUSTY WINDS WILL BE POSSIBLE DUE TO THE VERY STRONG SHEAR PROFILES...THE SEVERE THREAT SHOULD SHIFT EWD OFF THE ATLANTIC COAST BY MIDDAY AS THE FRONT MOVES OFFSHORE. ..BROYLES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 12:31:03 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 07:31:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081234 SWODY1 SPC AC 081232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST MON JAN 08 2007 VALID 081300Z - 091200Z ...NO SVR TSTM AREAS FORECAST... PROGRESSIVE LARGE SCALE TROUGH ERN U.S. WITH BROAD RIDGE OVER THE W. VIGOROUS S/WV TROUGH WITH ASSOCIATED STRONG WIND FIELDS CURRENTLY CROSSING APPALACHIANS WITH DEEPENING SURFACE LOW HEADING NEWD ACROSS SERN CANADA. COLD FRONT FROM SURFACE LOW SWWD E OF APPALACHIANS TO NRN FL WILL PUSH OFFSHORE BY MID DAY. THE VERY MOIST SWLY FLOW PRECEEDING FRONT CONTAINS VERY LITTLE INSTABILITY GIVEN LAPSE RATES LESS THAN 6 C/KM. BAND OF LOW TOPPED CONVECTION PRECEEDING FRONT WILL MOVE OFFSHORE BY MID MORNING ESSENTIALLY ENDING ANY SEVERE THREAT. GIVEN THE STRONG DEEP LAYER SHEAR THERE IS STILL A CHANCE OF A BRIEF SEVERE WIND GUST...ISOLATED TORNADO UNTIL THIS ACTIVITY MOVES OFFSHORE. REF MCD 0038. EXAMINING 12Z FLORIDA SOUNDINGS...LAPSE RATES AGAIN ARE WEAK AND THERE IS LITTLE SUPPORT FOR MORE THAN ISOLATED LIGHTNING STRIKES AS FRONTAL BAND MOVES SEWD ACROSS PENINSULA TODAY. ..HALES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 16:23:10 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 11:23:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081626 SWODY1 SPC AC 081624 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1024 AM CST MON JAN 08 2007 VALID 081630Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE MID/UPPER LEVEL TROUGH IS OVER THE ERN HALF OF THE U.S. THIS MORNING WITH A FLATTENING RIDGE OVER THE WRN U.S. LAST IN A SERIES OF EMBEDDED SHORTWAVES/VORTICITY MAXS WILL BE MOVING SEWD FROM THE NRN PLAINS INTO THE LOWER OHIO VALLEY DURING THE PERIOD WHICH WILL ESCORT THE ERN U.S. TROUGH INTO THE NERN/MID ATLANTIC REGIONS BY 09/12Z. LATEST SURFACE ANALYSIS SHOWS COLD FRONT EXTENDING SWD THROUGH ERN NEW YORK STATE AND ERN NC THEN SWWD ACROSS NRN FL. FRONT SHOULD BE WELL OFFSHORE BY 09/00Z WITH THE EXCEPTION OF THE SRN HALF OF FL WHERE THE FRONT WILL MOVE SWD THROUGH THE REMAINDER OF THE PENINSULA LATER TONIGHT. ...ERN CAROLINAS AND SRN NEW ENGLAND... LATEST LIGHTNING DATA SHOWS REMAINDER OF ACTIVITY IS SOUTH OF LONG ISLAND AND WELL OFFSHORE ALREADY. THUS...LOOKS LIKE ANY THUNDER PROBABILITIES WILL REMAIN THRU 18Z AND THEN DECREASE RAPIDLY AFTERWARDS AS THE FRONT MOVES EWD ACROSS NEW ENGLAND SWD ACROSS THE OUTER BANKS. CONVECTIVE POTENTIAL ACROSS FL HAS ALSO DECREASED RAPIDLY AS DYNAMIC FORCING HAS ALREADY SWUNG NEWD INTO NEW ENGLAND WITH SOUTH CENTRAL ATLANTIC RIDGE KEEPING GEOPOTENTIAL HEIGHTS AT/NEAR 5880 M AT THIS TIME. THUS...LACK OF SUFFICIENT LOW LEVEL FLOW/INSTABILITY SHOULD INHIBIT SEVERE THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD...AND THUNDERSTORM ACTIVITY IS EXPECTED TO LESSEN GOING INTO THIS AFTERNOON AND EVENING ACROSS THE MID ATLANTIC REGION. ..MCCARTHY.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 19:17:55 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 14:17:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081921 SWODY1 SPC AC 081919 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0119 PM CST MON JAN 08 2007 VALID 082000Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SRN FL PENINSULA... LATEST VIS SATELLITE/RADAR IMAGERY INDICATE SHOWERS ARE DEEPENING ACROSS THE SERN FL PENINSULA...ALONG SHARPENING LOW LEVEL CONFLUENCE ZONE...LIKELY ENHANCED BY DIABATIC HEATING. IT APPEARS CONVERGENCE WILL BE ADEQUATE FOR CONTINUED UPDRAFT DEVELOPMENT DESPITE THE VERY WEAK MID LEVEL LAPSE RATE ENVIRONMENT. CONTINUED BOUNDARY LAYER HEATING WILL ALSO ENHANCE THE PROSPECT FOR ISOLATED THUNDERSTORMS ALONG ADVANCING WIND SHIFT...WITH MORE DEVELOPMENT LIKELY OFF THE EAST COAST LATER THIS AFTERNOON/EVENING. ..DARROW.. 01/08/2007  From swody1 at goshenarc.org Tue Jan 9 00:51:11 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 19:51:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090054 SWODY1 SPC AC 090052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST MON JAN 08 2007 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... A LARGE UPPER-LEVEL TROUGH OVER THE OH AND TN VALLEYS WILL MOVE EWD TONIGHT AS A COLD FRONT MOVES SEWD ACROSS THE FL PENINSULA. LARGE-SCALE ASCENT AND LOW-LEVEL MOISTURE APPEAR SUFFICIENT FOR ISOLATED THUNDERSTORM DEVELOPMENT AROUND MIAMI FL THIS EVENING. HOWEVER...THE ACTIVITY SHOULD NOT REACH SEVERE LIMITS. ELSEWHERE...THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS. ..BROYLES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 05:24:43 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 00:24:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090528 SWODY1 SPC AC 090527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST MON JAN 08 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... AN UPPER-LEVEL TROUGH OVER THE ERN UNITED STATES WILL MOVE EWD TODAY AS A COLD FRONT MOVES QUICKLY INTO THE ATLANTIC COASTAL AREAS BY MIDDAY. THUNDERSTORM DEVELOPMENT WILL BE LIKELY AS THE BOUNDARY MOVES OFFSHORE DURING THE EVENING. ELSEWHERE...AN UPPER-LEVEL DISTURBANCE WILL MOVE INTO THE PACIFIC NORTHWEST TUESDAY NIGHT. A FEW THUNDERSTORMS WILL BE POSSIBLE ALONG THE WA COAST. HOWEVER...NO SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE CONUS TUESDAY OR TUESDAY NIGHT. ..BROYLES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 12:31:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 07:31:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091234 SWODY1 SPC AC 091232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST TUE JAN 09 2007 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... THE ONLY AREA THAT WILL HAVE ANY THREAT OF ISOLATED LIGHTNING THIS FORECAST PERIOD IS ALONG AND OFFSHORE THE WA COAST. VERY COLD TROUGH DIGS SEWD OUT OF THE GULF OF ALASKA AND BY THE END OF THE FORECAST PERIOD AN ONSHORE FLOW OF COLD UNSTABLE AIR WILL BE AFFECTING WRN WA. LIGHTNING EXPECTED TO REMAIN PRIMARILY OFFSHORE WHERE STEEP LAPSE RATES TO NEAR 500MB COUPLED WITH THE OVER WATER TRAJECTORY WILL SUPPORT CONVECTION. SUPPORT FOR ANY LIGHTNING WILL DIMINISH INLAND AWAY FROM THE COMPARATIVELY WARM WATER SOURCE. ..HALES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 16:24:10 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 11:24:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091627 SWODY1 SPC AC 091625 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1025 AM CST TUE JAN 09 2007 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... CYCLONIC CIRCULATION EXPECTED TO AMPLIFY OFF THE BC CST DURING THE NEXT 24 HRS AS ASSOCIATED SFC LOW REDEVELOPS E OF THE CANADIAN RCKYS. ONSHORE UPSLOPE FLOW WILL STRENGTHEN AND DEEPEN OVER WRN WA AND ORE TONIGHT/EARLY WEDNESDAY AS COLD FRONT SWEEPS E OF THE CASCADES. THIS PATTERN LIKELY WILL RESULT IN FAIRLY WIDESPREAD POST-FRONTAL CONVECTION...ESPECIALLY IN WRN WA. WITH 500 MB TEMPERATURES FALLING TO AOB MINUS 30C AND RELATIVELY MILD AIR PERSISTING NEAR THE SURFACE...POTENTIAL WILL EXIST FOR CHARGE SEPARATION/LIGHTING. SUPPORT FOR ANY LIGHTNING SHOULD DIMINISH INLAND AWAY FROM THE COMPARATIVELY WARM WATER. IN THE EAST...AN ISOLATED STRIKE OR TWO COULD OCCUR WITH UNIDIRECTIONAL WLY FLOW IN THE LEE OF LK ONTARIO TODAY...AND ON THE UPSLOPE SIDE OF THE CNTRL APLCNS...AHEAD OF SHORTWAVE IMPULSE IN BROAD CYCLONIC JET. ..CORFIDI.. 01/09/2007  From swody1 at goshenarc.org Fri Jan 12 06:18:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 01:18:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120550 SWODY1 SPC AC 120548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST THU JAN 11 2007 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SIGNIFICANT MID-UPPER LEVEL PATTERN SHIFT UNDERWAY AS HEIGHTS FALL ACROSS WRN CONUS. POSITIVELY TILTED TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM SASK TO N-CENTRAL CA -- IS EXPECTED TO STRENGTHEN IN SRN PORTION WITH CLOSED LOW EVOLVING OVER NV EARLY IN PERIOD. ASSORTED MESOSCALE VORTICITY LOBES WILL PIVOT AROUND ASSOCIATED CIRCULATION...AS NET CYCLONE TRACK SLOWLY CURVES EWD OVER UT BY END OF PERIOD. AT SFC...INTENSE ARCTIC COLD FRONT NOW ANALYZED FROM ERN IA ACROSS SERN KS TO CENTRAL TX PANHANDLE -- IS FCST TO MOVE SWD TO POSITION OVER OH VALLEY..ARKLATEX...W-CENTRAL TX BY END OF PERIOD. KINEMATIC RESPONSES ASSOCIATED WITH LOW LEVEL CYCLOGENESIS OVER NWRN NM/SWRN CO SHOULD IMPEDE SWWD PROGRESS OF FRONT ACROSS ERN NM...AND IN FACT MAY CAUSE SOME NWD RETREAT THERE. ...SRN PLAINS...BIG BEND/PECOS VALLEY TO OZARKS... MRGL SVR POTENTIAL MAY DEVELOP DURING AFTERNOON ACROSS PORTIONS CENTRAL/NRN TX AHEAD OF FRONT...WHERE 50-60 KT MIDLEVEL SWLYS AND SELY SFC WINDS WILL CONTRIBUTE TO FAVORABLY LARGE DEEP-LAYER SHEAR VECTORS AND LOW LEVEL HODOGRAPHS. MAIN CAVEATS WILL BE WEAKNESS OF BOTH BUOYANCY AND LOW LEVEL FORCING FOR CONVECTION...IN ABSENCE OF ANY SIGNIFICANT PREFRONTAL BOUNDARIES. ALTHOUGH SHADED BY MID/UPPER CLOUDS FOR MUCH OF DAY...SUFFICIENT SFC HEATING MAY DEVELOP TO SUPPORT HORIZONTAL CONVECTIVE ROLLS...WITH SOME DEEPER DEVELOPMENT POSSIBLE DURING AFTERNOON WHEN SBCINH IS SMALLEST. WEAK LAPSE RATES ALOFT SHOULD LIMIT MLCAPES TO BELOW 500 J/KG IN MOST AREAS...AND ONLY SMALL PROPORTION OF CONVECTION MAY REACH OPTIMAL ICING LAYERS FOR CG LIGHTNING PRODUCTION. HOWEVER...GIVEN ENVIRONMENTAL SHEAR PROFILES...STORM ROTATION IS POSSIBLE WITH NONZERO RISK OF A TORNADO OR DAMAGING GUST. THIS THREAT SHOULD SHIFT GRADUALLY TOWARD HAIL AND ISOLATED WIND WITH WWD EXTENT -- ESPECIALLY INTO TRANS-PECOS...PERMIAN BASIN AND BIG BEND REGION WHERE SOMEWHAT HIGHER LCL...STEEPER DEEP-LAYER LAPSE RATES...AND LARGER BUOYANCY ARE EXPECTED. AFTERNOON/EARLY EVENING SHEAR PROFILES ALONG AND S OF FRONT SHOULD BE FAVORABLE FOR SUPERCELLS...WITH 40-50 KT EFFECTIVE SHEAR EVIDENT IN NAM/NAM-KF FCST SOUNDINGS...AND MLCAPE TO NEAR 700 J/KG. CONVECTIVE COVERAGE MAY BE LIMITED BY WEAK LOW LEVEL FORCING IN THIS REGION AS WELL. SVR POTENTIAL IN ALL AREAS APPEARS TO BE TOO MRGL/CONDITIONAL TO WARRANT CATEGORICAL OUTLOOK ATTM. ALTHOUGH LAPSE RATES ALOFT WILL BE WEAK...ISOLATED/EPISODIC GEN THUNDER POTENTIAL MAY EXIST AS FAR NE AS SWRN MO/WRN KY AND AS FAR N AS ATOP FREEZING SFC TEMPS IN PORTIONS OK/KS OVERNIGHT...SUPPORTED BY LOW LEVEL WAA REGIME...ASSOCIATED MOISTENING INVOF LLJ...AND ISENTROPIC ASCENT TO LFC. ..EDWARDS.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 12:39:29 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 07:39:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121242 SWODY1 SPC AC 121240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST FRI JAN 12 2007 VALID 121300Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS... ARCTIC COLD FRONT CONTINUES TO SURGE SWD INTO THE SRN PLAINS THIS MORNING WITH A POSITION EXTENDING FROM THE MID MS RIVER VALLEY SWWD INTO CENTRAL OK AND WEST TX AT 11Z. CONSIDERABLE COLD/DENSE SURFACE AIR BEHIND THE FRONT WILL MAINTAIN A RATHER STEADY SSEWD MOTION THROUGH THE PERIOD...DESPITE THE SWLY MID/UPPER LEVEL FLOW PREVAILING ACROSS THE WARM SECTOR. THE FRONT WILL LIKELY EXTEND FROM CENTRAL/SERN NM ENEWD INTO CENTRAL/NERN TX AND SERN MO BY THE EARLY EVENING. A SSWLY LLJ WILL BE SUSTAINED ACROSS MUCH OF TX POINTING INTO THE MID MS RIVER VALLEY THROUGH THE PERIOD AHEAD OF SLOW MOVING UPPER LOW DIGGING SSEWD ACROSS THE GREAT BASIN AND THE SWRN DESERTS. RESULTANT ISENTROPIC LIFTING WILL MAINTAIN A PERSISTENT AREA OF ELEVATED MOIST CONVECTION FROM PORTIONS OF WRN/CENTRAL TX ACROSS THE OZARK PLATEAU FOR MUCH OF THE PERIOD. WEAK ELEVATED INSTABILITY MAY SUPPORT ISOLATED THUNDERSTORMS WITHIN THIS BROAD AREA OF CONVECTION...LOCALLY ENHANCING RAINFALL AND FREEZING PRECIPITATION NORTH OF THE COLD FRONT. ACROSS THE WARM SECTOR...EXTENSIVE CLOUDS AND WEAK LOW LEVEL CONVERGENCE WILL BE INHIBITING FACTORS FOR NEAR-SURFACE BASED CONVECTION TODAY. HOWEVER...INCREASE FETCH OF MODIFIED GULF MOISTURE /I.E. SURFACE DEW POINTS IN THE MID 60SF/ AND TEMPERED AFTERNOON HEATING MAY STILL SUPPORT AREAS OF MARGINAL SURFACE BASED INSTABILITY AND MINIMAL SURFACE BASED CIN DURING THE AFTERNOON. IN ADDITION...MUCH OF THE REGION WILL REMAIN WITHIN MODEST DEEP LAYER SHEAR UNDER 40-50 KT SWLY MID LEVEL WINDS. THUS...A FEW STORMS MAY BECOME STRONG TO MARGINALLY SEVERE LATER TODAY AND EARLY THIS EVENING AHEAD OF THE SHALLOW COLD FRONT MAINLY ACROSS PORTIONS OF SWRN/CENTRAL TX. ..EVANS.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 16:30:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 11:30:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121633 SWODY1 SPC AC 121631 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1031 AM CST FRI JAN 12 2007 VALID 121630Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE DEVELOPING CLOSED LOW OVER NV/CA WILL MOVE SLOWLY EWD OVER THE SRN GREAT BASIN THROUGH EARLY SATURDAY...WITH A BROAD SWATH OF SW FLOW ALOFT DOWNSTREAM OVER THE CENTRAL AND ERN CONUS. IN THE LOW-LEVELS...A SHARP ARCTIC FRONT IS MOVING SLOWLY SEWD ACROSS THE SRN PLAINS AND MID MS VALLEY. PRONOUNCED WAA ABOVE THE FRONTAL SURFACE IS SUPPORTING AN INCREASING AREA OF PRECIPITATION NEAR AND N OF THE FRONT FROM NW TX INTO CENTRAL OK...AND THIS PRECIPITATION SHOULD INCREASE IN COVERAGE WHILE SPREADING NEWD TO THE OH VALLEY LATER TODAY THROUGH TONIGHT. MUCH OF THE PRECIPITATION WILL BE FREEZING RAIN A COUPLE OF COUNTIES N OF THE SURFACE FRONT...WHERE WEAK MID LEVEL INSTABILITY COULD SUPPORT A FEW EMBEDDED ELEVATED THUNDERSTORMS. FARTHER S...BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S WILL BE MAINTAINED ALONG THE FRONT FROM NE INTO CENTRAL TX...WHILE DEWPOINTS SHOULD REACH THE UPPER 60S ACROSS THE LOWER TX COAST. REGIONAL 12Z SOUNDINGS SHOW THE POTENTIAL FOR WEAK SURFACE-BASED INSTABILITY NEAR THE FRONT...ALONG WITH DEEP LAYER VERTICAL SHEAR THAT WILL BE SUFFICIENT FOR ORGANIZED SEVERE STORMS. HOWEVER...THE FLOW REGIME IS LARGELY ANAFRONTAL WHERE CONVECTION THAT FORMS ALONG THE FRONT WILL MOVE OVER THE SHALLOW COLD AIR MASS...LIMITING ANY WIND DAMAGE/TORNADO THREAT. SOMEWHAT STEEPER MID LEVEL LAPSE RATES OVER W TX COULD ALLOW FOR SOME SMALL HAIL WITH THE STRONGER CONVECTION...THOUGH STORM COVERAGE IS IN QUESTION THIS FAR SW. ..THOMPSON.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 19:39:36 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 14:39:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121942 SWODY1 SPC AC 121940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST FRI JAN 12 2007 VALID 122000Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL CONTINUE MOVING ACROSS THE WRN U.S. THROUGH THE END OF THE PERIOD...WITH ASSOCIATED CLOSED LOW CROSSING THE GREAT BASIN. LOW-LEVEL SLY FLOW DOWNSTREAM OF THIS FEATURE RIDING ATOP SHALLOW/SWD-MOVING COLD FRONT WILL CONTINUE TO SUPPORT WIDESPREAD PRECIPITATION AND EMBEDDED THUNDERSTORMS ACROSS THE S CENTRAL U.S. THROUGH 13/12Z. ...FAR SERN NM ACROSS PARTS OF CENTRAL AND NRN TX... WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SRN PLAINS THROUGH THE END OF THE PERIOD...AS COLD FRONT CONTINUES MOVING SWD AND SWLY FLOW ALOFT PERSISTS AHEAD OF WRN TROUGH. THOUGH DEWPOINTS IN THE 60S HAVE ADVECTED NWD INTO CENTRAL AND NERN TX AHEAD OF FRONT...WEAK LAPSE RATES AND WARM NOSE IN THE 850 TO 700 MB LAYER ARE RESULTING IN MINIMALLY-UNSTABLE/CAPPED AIRMASS. THOUGH SHEAR WILL REMAIN SUPPORTIVE FOR ORGANIZED STORMS...LACK OF INSTABILITY AND GENERALLY UNFAVORABLE THERMODYNAMICS PRECLUDE APPRECIABLE SEVERE THREAT -- PARTICULARLY GIVEN NNELY MEAN WIND AND ASSOCIATED TENDENCY FOR ANY SURFACE-BASED STORMS WHICH COULD DEVELOP NEAR FRONT TO MOVE NWD ACROSS THE BOUNDARY AND BECOME ELEVATED. A LIMITED THREAT FOR MARGINALLY-SEVERE HAIL MAY DEVELOP OVERNIGHT ACROSS FAR SERN NM AND INTO FAR W TX AND THE TRANSPECOS REGION AS STEEPER LAPSE RATES APPROACH FROM THE W. ELSEWHERE...WILL MAINTAIN VERY LOW PROBABILITY THREAT FOR A WEAK/BRIEF TORNADO OR LOCAL WIND GUST NEAR THE FRONT FROM THE HILL COUNTRY REGION NEWD INTO NERN TX THROUGH THE END OF THE PERIOD. ..GOSS.. 01/12/2007  From swody1 at goshenarc.org Sat Jan 13 00:33:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 19:33:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130036 SWODY1 SPC AC 130034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST FRI JAN 12 2007 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SWLY FLOW ALOFT WILL BE MAINTAINED OVER MUCH OF CENTRAL CONUS...DOWNSTREAM FROM STRONG MID-UPPER LEVEL CYCLONE NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN NV. THIS LOW IS FCST TO MOVE SLOWLY EWD OVER SWRN UT THROUGH REMAINDER PERIOD...WITH ASSOCIATED SFC LOW OVER CENTRAL/SWRN CO. STRONG ARCTIC COLD FRONT SHOULD CONTINUE TO MOVE SEWD ACROSS ARKLATEX REGION...AND CENTRAL/SW TX. FRONT WILL MOVE MORE SLOWLY OVER CENTRAL/SERN NM...AND EXTEND NWWD INTO SFC LOW. ...TX... FAVORABLE LOW LEVEL AND DEEP-LAYER SHEAR...COMBINED WITH WEAK SFC-BASED BUOYANCY AND MINIMAL CINH...AIDED IN DEVELOPMENT OF STRONG SHOWERS AND A FEW TSTMS S OF COLD FRONT OVER CENTRAL TX. ONE OF THESE SPAWNED SMALL TORNADO NEAR I-35 IN BELL COUNTY...AT 2244Z. MODIFIED VWP AND RUC SOUNDINGS INDICATE 200-250 0-1 KM SRH...BENEATH 40-50 KT 500 MB FLOW THAT WILL CONTRIBUTE TO 40-45 KT 0-6 KM SHEAR. ALTHOUGH BRIEF TORNADO CANNOT BE RULED OUT FOR CONVECTION IN WARM SECTOR...ALREADY MRGL THERMODYNAMIC CONDITIONS WILL BECOME LESS FAVORABLE FROM NW-SE. IN ADDITION TO GRADUAL DIABATIC COOLING IN WARM SECTOR...STRONG DENSITY CURRENT BEHIND COLD FRONT IS FCST TO UNDERCUT ACTIVITY MOVING NNEWD ACROSS CENTRAL TX...AMIDST EFFECTIVELY ANAFRONTAL FLOW REGIME. ..EDWARDS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 05:43:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 00:43:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130546 SWODY1 SPC AC 130544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...SYNOPTIC SCALE TROUGH IS FCST TO REMAIN OVER WRN CONUS...AS EMBEDDED UPPER VORTEX NOW OVER NV/UT BORDER REGION MOVES/REDEVELOPS NEWD OVER WY. MEANWHILE...STRONG VORTICITY LOBE PIVOTING THROUGH BASE OF TROUGH MAY EVOLVE INTO CLOSED OR NEARLY CLOSED LOW FARTHER SW OVER 4-CORNERS AREA...BY 14/12Z. ALTHOUGH LATEST OPERATIONAL SPECTRAL/NAM AND VARIOUS SREF MEMBERS FROM 12/21Z RUN DIFFER SOME ON GEOMETRY AND RELATIVE STRENGTH OF EACH LOW...GENERAL SCENARIO IS IN GOOD AGREEMENT. THIS FOMENTS HIGH CONFIDENCE IN PRESENCE OF EXTENSIVE BELT OF MID-UPPER SWLYS FROM NRN MEX ACROSS SRN/CENTRAL PLAINS TO OH VALLEY THROUGH MOST OF PERIOD...JUXTAPOSED OVER BROAD REGIME OF LOW LEVEL WAA/MOISTURE TRANSPORT. AT SFC...INTENSE ARCTIC COLD FRONT -- NOW ANALYZED FROM SERN NM INTO CENTRAL TX THEN NEWD ACROSS SRN IL -- IS EXPECTED TO MOVE SLOWLY SWD ACROSS LOWER OH VALLEY...AR AND INTO S-CENTRAL TX. WEAK LOW MAY FORM AND MOVE NEWD ALONG FRONT...ACROSS AR...AS SRN STREAM MIDLEVEL PERTURBATION NOW OVER BAJA/NERN MEX EJECT NEWD. WRN SEGMENT OF FRONT OVER SW TX AND SERN NM MAY STALL OR DECELERATE CONSIDERABLY...WITH STRONG/PRIMARY SFC CYCLONE EXPECTED TO RE-FORM OVER CENTRAL NM BY LATE IN PERIOD. ...SE TX TO SRN AR... VERTICAL SHEAR PROFILES S OF FRONT WILL BE FAVORABLE FOR ANY SUSTAINED/DISCRETE CONVECTION TO ROTATE...ESPECIALLY IF SFC WINDS ARE BACKED SOMEWHAT BY WEAK FRONTAL-WAVE LOW DEVELOPMENT INDICATED IN SPECTRAL/NAM GUIDANCE. MAIN CONCERNS WILL BE CONVECTIVE MODE... PLACEMENT RELATIVE TO SFC-BASED INFLOW...AND LACK OF DEEPER AND MORE ROBUST BUOYANCY. NUMEROUS SHOWERS WITH EMBEDDED TSTMS MAY DEVELOP INVOF FRONT...LEAVING MOST PROBABLE AREA FOR DISCRETE DEVELOPMENT ASSOCIATED WITH WEAK BOUNDARY LAYER FORCING TO ITS S...DURING AFTERNOON. FCST SOUNDINGS INDICATE VERY SIMILAR REGIME TO THAT OVER CENTRAL TX PREVIOUS DAY...WITH MLCAPE PROFILES BELOW 500 J/KG IN MAGNITUDE AND REMAINING MOSTLY BELOW LAYERS MOST SUITABLE FOR CG LIGHTNING PRODUCTION. BRIEF TORNADO CANNOT BE RULED OUT...BUT PROBABILITIES APPEAR TOO LIMITED TO WARRANT CATEGORICAL SVR OUTLOOK ATTM. ...S-CENTRAL/SW TX... RELATIVE WEAKNESS IN LOW LEVEL VERTICAL SHEAR IS FCST OVER DEEP S TX AND S-CENTRAL TX...MAINLY DUE TO DESTRUCTIVE INFLUENCE OF RELATIVELY WEAK 1-3 KM AGL FLOW ON HODOGRAPH SIZE. THESE WEAKNESSES ARE LESS EVIDENT FARTHER NW TOWARD LOWEST PECOS VALLEY REGION...HOWEVER AFTERNOON SBCINH MAY BE STRONGER. REASONABLE PRESENCE OF SSELY-SELY SFC WINDS AND 40-50 KT WINDS IN MIDDLE PORTION OF BUOYANT PROFILES YIELDS FAVORABLE EFFECTIVE SHEARS OF 40-50 KT IN SUPPORT OF SOME STORM ORGANIZATION EVEN WHERE WEAKNESSES ARE EVIDENT ATOP BOUNDARY LAYER. WITH ANAFRONTAL NET FLOW REGIME...ACTIVITY FORMING S OF FRONT EFFECTIVELY MAY BE UNDERCUT BY FRONT...HOWEVER MRGL POTENTIAL FOR SFC-BASED SVR IN WARM SECTOR IS EVIDENT AND WILL BE REFLECTED IN UNCONDITIONAL PROBABILITIES. ALTHOUGH CAPPING WILL INCREASE WITH SWD EXTENT...HEATING MAY BE SUFFICIENT TO WEAKEN CINH AND SUPPORT DEVELOPMENT NEAR AND S OF FRONT...AND ALSO ALONG ERN SLOPES OF SERRANIAS DEL BURRO RANGE OF NRN MEX. ANY ACTIVITY DEVELOPING OVER MEX MOUNTAINS MAY MOVE NEWD ACROSS RIO GRANDE INTO S TX DURING LATE AFTERNOON/EARLY EVENING...HOWEVER EXTENSIVE MID/HIGH CLOUD COVER MAY RESTRICT HEATING OF HIGHER TERRAIN AND LIMIT OR PREVENT SUCH DEVELOPMENT. GIVEN THESE UNCERTAINTIES...SVR PROBABILITIES ARE KEPT MRGL FOR THIS AREA AS WELL. ..EDWARDS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 12:46:51 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 07:46:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131249 SWODY1 SPC AC 131247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST SAT JAN 13 2007 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS INTO THE LOWER OH RIVER VALLEY... PAIR OF PROGRESSIVE SHORTWAVE TROUGHS CONTINUE TO EJECT OUT OF BROADER WRN U.S. TROUGH THIS MORNING. LEADING WAVE RESPONSIBLE FOR CONSIDERABLE RAIN/ZR/IP ACROSS THE SRN PLAINS INTO THE LOWER OH RIVER VALLEY WILL CONTINUE TO LIFT NEWD WITH DIMINISHING THUNDERSTORM POTENTIAL. SECOND IMPULSE APPEARED TO BE EJECTING ACROSS THE SRN HIGH PLAINS EARLY THIS MORNING. AT THE SURFACE...ARCTIC COLD FRONT NOW EXTENDING FROM THE LOWER OH RIVER VALLEY INTO THE ARKLATEX AND THE TX HILL COUNTRY AT 12Z. MODEL GUIDANCE INDICATES A WAVE WILL FORM ALONG THIS FRONT INTO SRN/SERN AR THROUGH THE AFTERNOON. LLJ WILL REMAIN ACROSS MOST OF ERN TX INTO THE LOWER OH RIVER VALLEY TODAY...BEFORE REFORMING FARTHER WEST OVERNIGHT IN RESPONSE TO MAIN UPPER TROUGH EXPECTED TO BEGIN EJECTING ENEWD LATE IN THE PERIOD. SIMILAR TO YESTERDAY...WARM SECTOR AIR MASS WILL BE SLOW TO DESTABILIZE TODAY WITH EXTENSIVE CONVECTION ACROSS MUCH OF AREA WITHIN PERSISTENT LOW LEVEL WAA. HOWEVER...DEEP LAYER SHEAR WILL REMAIN MORE THAN ADEQUATE FOR ROTATING STORMS UNDER MODERATE SWLY FLOW ALOFT AS EVIDENCED BY 12Z SHV SOUNDING. IN ADDITION...INFLUX OF LOWER/MID 60F SURFACE DEW POINTS AND POSSIBLE SURFACE PRESSURE FALLS FROM NERN TX INTO PORTIONS OF AR MAY SUPPORT STRONG TO MARGINALLY SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING ACROSS THIS AREA. FARTHER WEST TOWARDS THE BIG BEND REGION...DEEP LAYER SHEAR IS ALREADY QUITE STRONG ACCORDING TO 12Z SOUNDING AT DRT AND MID LEVEL LAPSE RATES ARE MODERATELY STEEP. HEATING WILL BE MODULATED BY MID LEVEL CLOUDS/MOISTURE FEEDING OFF THE PACIFIC. HOWEVER...LOW SEVERE PROBABILITIES ARE WARRANTED SHOULD SURFACE BASED CAPE BE REALIZED THIS AFTERNOON/EARLY EVENING AHEAD OF THE FRONT. ..EVANS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 16:27:22 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 11:27:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131630 SWODY1 SPC AC 131628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1028 AM CST SAT JAN 13 2007 VALID 131630Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... QUASI-STATIONARY UPPER LOW OVER THE GREAT BASIN IS EXPECTED TO BEGIN MOVING ESEWD TODAY AND REACH THE FOUR-CORNERS REGION BY LATE TONIGHT IN RESPONSE TO UPSTREAM SHORT WAVE TROUGH DROPPING SSEWD ACROSS THE PACIFIC NW. AT THE SURFACE...COLD FRONT EXTENDS FROM A WEAK LOW NEAR TXK SWWD THEN WWD ACROSS SOUTH CENTRAL TX...WITH A QUASI-STATIONARY FRONT NEWD FROM THE LOW INTO THE LOWER OH VALLEY. THE LOW IS FORECAST TO MOVE SLOWLY NEWD ALONG THE QUASI-STATIONARY FRONT AS THE TRAILING COLD FRONT MOVES SWD/SEWD ACROSS SERN/SOUTH CENTRAL TX THROUGH TONIGHT. ...SOUTH CENTRAL TX... SEVERAL NNE-SSW ORIENTED BANDS OF THUNDERSTORMS HAVE BEEN DEVELOPING OVER SOUTH CENTRAL TX SOUTH OF THE COLD FRONT WITH STORMS INTENSIFYING AS THEY CROSS THE FRONT AND MOVE NWD INTO A REGION OF ELEVATED INSTABILITY. THE CONVECTION MAY BE ASSOCIATED WITH INCREASED DYNAMIC FORCING AS A MID/UPPER LEVEL PERTURBATION EVIDENT IN WATER VAPOR IMAGERY MOVES NEWD TOWARD SWRN TX...WITH MESOSCALE ASCENT ENHANCED BY PERSISTENT LOW LEVEL WARM ADVECTION/ISENTROPIC LIFT ALONG/NORTH OF THE FRONT. SURFACE AIR MASS WITHIN WARM SECTOR IS WARM/MOIST WITH TEMPERATURES IN THE UPPER 60S/LOWER 70S AND DEW POINTS IN THE MID/UPPER 60S...RESULTING IN MLCAPE OF 500-1000 J/KG. ELEVATED INSTABILITY WITH MUCAPE OF 200-500 J/KG EXTENDS TO THE NORTH/NORTHWEST OF THE SURFACE FRONT. EXTENSIVE CLOUDS ARE EXPECTED TO INHIBIT DIABATIC HEATING THIS AFTERNOON...ALTHOUGH VISIBLE IMAGERY SHOWS SOME BREAKS IN CLOUD COVER CLOSER TO THE RIO GRANDE WHERE A FEW AREAS OF STRONGER HEATING/DESTABILIZATION MAY OCCUR. MODERATELY STRONG SWLY FLOW ALOFT WILL MAINTAIN SUFFICIENT DEEP LAYER SHEAR /35-45 KT IN THE LOWEST 6 KM/ TO ENHANCE STORM ORGANIZATION AND INTENSITY...SUGGESTING POTENTIAL FOR ISOLATED SEVERE STORMS TO OCCUR THROUGH THIS AFTERNOON INTO THE EVENING. THIS THREAT MAY BE LOCALLY INCREASED NEAR THE FRONT WHERE VERTICAL SHEAR WILL BE ENHANCED...SUGGESTING THREAT FOR A BRIEF TORNADO IN ADDITION TO MARGINAL HAIL OR STRONG WIND GUSTS. HOWEVER...STORMS ARE EXPECTED TO QUICKLY BECOME ELEVATED AS THEY MOVE NORTH OF THE FRONT. ADDITIONAL ELEVATED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER TONIGHT NORTH OF THE FRONT OVER PARTS OF WEST CENTRAL INTO CENTRAL TX AS LOW LEVEL JET DEVELOPS WWD INTO TX IN ASSOCIATION WITH THE UPPER LOW MOVING INTO THE FOUR-CORNERS REGION. MARGINAL HAIL MAY OCCUR WITH ISOLATED STORMS. ...SERN TX INTO SRN AR... A NARROW AXIS OF INSTABILITY IS IN PLACE ALONG AND IMMEDIATELY AHEAD OF THE FRONT FROM SERN TX INTO SRN AR. VISIBLE IMAGERY SHOWS BREAKS IN CLOUD COVER FROM EAST CENTRAL TX INTO NORTH CENTRAL LA WHERE DIURNAL HEATING WILL BE ENHANCED. HOWEVER...LAPSE RATES ARE EXPECTED TO REMAIN WEAK WHICH WILL LIMIT MLCAPE TO AOB 500 J/KG. 12Z NAM AND ETAKF CONTROL MEMBER FROM THE 09Z SREF INDICATE NEW CONVECTION DEVELOPING ALONG THE FRONT THIS AFTERNOON INTO THE EVENING WITHIN LOW CAPE/HIGH SHEAR ENVIRONMENT. THIS SUGGESTS THREAT FOR AN ISOLATED SEVERE STORM OR TWO TO DEVELOP...BUT WEAK INSTABILITY AND LIMITED FORCING FOR ASCENT SHOULD LIMIT OVERALL SEVERE POTENTIAL. ..WEISS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 19:43:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 14:43:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131947 SWODY1 SPC AC 131944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0144 PM CST SAT JAN 13 2007 VALID 132000Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH WILL CONTINUE SHIFTING EWD ACROSS THE ROCKIES THIS PERIOD...WITH EMBEDDED UPPER LOW TO REACH THE FOUR CORNERS REGION BY THE END OF THE PERIOD. AT THE SURFACE...COLD FRONT WILL CONTINUE MOVING SWD ACROSS SRN AND ERN TX...WITH SUBTLE LOW LIKELY TO PERSIST INVOF SRN AR ALONG FRONT THROUGH THE PERIOD. ...MIDDLE RIO GRANDE VALLEY/PARTS OF S TX NEWD INTO NRN LA/SRN AR... SHOWERS AND SCATTERED THUNDERSTORMS ARE ONGOING ATTM WITHIN MARGINAL/ELEVATED INSTABILITY N OF SURFACE FRONT...WHICH NOW EXTENDS FROM A WEAK LOW IN SWRN AR SSWWD ACROSS E TX...AND THEN WWD ACROSS SRN PORTIONS OF THE HILL COUNTRY TO NEAR DRT. AOB 1000 J/KG MEAN-LAYER CAPE IS INDICATED ACROSS DEEP S TX FROM ROUGHLY SAT SWD...THOUGH AIRMASS REMAINS CAPPED ATTM. THIS CAPPING SHOULD CONTINUE TO GENERALLY INHIBIT CONVECTIVE DEVELOPMENT S OF FRONT THROUGH THE PERIOD. GREATEST POTENTIAL FOR THUNDERSTORMS REMAINS N OF FRONT...WHERE WARM ADVECTION/ISENTROPIC LIFT PROVIDES SUFFICIENT LOW-LEVEL ASCENT FOR STORM INITIATION. HOWEVER...MUCH WEAKER INSTABILITY N OF BOUNDARY SUGGESTS ONLY A LIMITED HAIL THREAT -- MAINLY FROM THE RIO GRANDE VALLEY EWD ACROSS THE HILL COUNTRY. ANY STORMS WHICH COULD DEVELOP NEAR OR JUST S OF FRONT WOULD QUICKLY BE CARRIED NNEWD ACROSS THE BOUNDARY ACROSS THIS REGION...SO SURFACE-BASED SEVERE THREAT SHOULD REMAIN QUITE LOW. FURTHER NE...FRONT IS ORIENTED SSW-NNE ACROSS E TX. IN THIS REGION...MUCH MORE LIMITED INSTABILITY AND LOW-LEVEL CAP IS HINDERING THE POTENTIAL FOR ORGANIZED STORMS...DESPITE FAVORABLE DEEP-LAYER SHEAR. HOWEVER...WILL MAINTAIN LOW-PROBABILITY THREAT FOR AN ISOLATED WIND GUST OR WEAK/BRIEF TORNADO...AS CELL MOTION WOULD MORE CLOSELY PARALLEL THE FRONT AND PERHAPS ALLOW A STORM TO REMAIN SURFACE-BASED AS IT SHIFTS NNEWD. ..GOSS.. 01/13/2007  From swody1 at goshenarc.org Sun Jan 14 00:38:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 19:38:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140041 SWODY1 SPC AC 140039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST SAT JAN 13 2007 VALID 140100Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SERN TX NEWD INTO NRN LA/SRN AR... 00Z SFC ANALYSIS PLACES A WEAK FRONTAL WAVE JUST W OF KSHV. THIS WAVE WILL TRANSLATE NEWD INTO THE MID-SOUTH LATER TONIGHT. SFC COLD FRONT IS THEN EXPECTED TO RESUME A FASTER SEWD MOTION ACROSS THE UPPER TX COAST AND NRN LA/SRN AR BY 12Z. SRN PORTION OF THIS FRONT WILL BE SLOWER TO ADVANCE SWD THROUGH SCNTRL/DEEP S TX. STRONGEST LLJ MAX WILL LIKELY TRANSLATE NEWD FROM E TX THIS EVE INTO THE MID-SOUTH OVERNIGHT IN TANDEM WITH THE FRONTAL WAVE. UNTIL THEN...WARM ADVECTION ENHANCED SFC-BASED TSTMS WILL CONTINUE TO FORM AHEAD OF THE FRONT. 0-1KM SRH OF 150-200 M2/S2 COINCIDENT WITH A MOIST BOUNDARY LAYER WILL BE SUFFICIENT TO MAINTAIN A LOW PROBABILITY OF AN ISOLD TORNADO IN ADDITION TO RISKS OF ISOLD DAMAGING WINDS. BUT...THERE WILL BE A TENDENCY FOR THE ADVANCING COLD AIR TO UNDERCUT THE UPDRAFTS AND REDUCE THE SEVERE THREATS WITH ANY GIVEN UPDRAFT. THUS...THE PRIMARY HAZARD WILL LIKELY REMAIN HVY RNFL. FARTHER S...PROMINENT CAP AROUND THE H85 LEVEL S OF THE COLD FRONT AND LACK OF STRONGER LARGE SCALE FORCING WILL REDUCE THE CHANCES FOR TSTMS. ELSEWHERE...LATER TONIGHT...CONVECTION WILL INCREASE ACROSS PARTS WCNTRL...NWRN AND CNTRL TX BETWEEN 09-12Z AS A BRANCH OF THE LLJ BACKS AND INCREASES AHEAD OF THE SRN ROCKIES IMPULSE. TSTMS WILL BE POSSIBLE AS THE COLUMN SATURATES. 00Z SOUNDINGS SHOW 3-6 KM LAPSE RATES IN EXCESS OF 7 DEG C PER KM FURTHER LENDING CONFIDENCE FOR AT LEAST LOW TSTM PROBABILITIES. ..RACY.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 05:41:55 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 00:41:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140545 SWODY1 SPC AC 140542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1142 PM CST SAT JAN 13 2007 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...S AND E TX NEWD INTO THE MID-SOUTH... THE UPPER LEVEL IMPULSE LOCATED ACROSS AZ IS EXPECTED TO EJECT ENEWD TO THE CNTRL PLAINS BY SUNDAY NIGHT AS A NEW SPEED MAX DROPS SEWD INTO THE SWRN DESERTS. ATTENDANT UPPER LEVEL JET OF 150+ KTS WILL PROPAGATE NEWD ALONG THE BASE OF THE TROUGH WITH THE ENTRANCE REGION SPREADING ACROSS THE SRN PLAINS. SUBTROPICAL MOISTURE PLUME WAS WELL-ESTABLISHED FROM SCNTRL TX NEWD INTO THE LWR OH/MS VLYS PER 00Z RAOBS. AS AGEOSTROPHIC FORCING DEVELOPS EARLY SUNDAY IN RESPONSE TO THE UPSTREAM TROUGH...NWRN PORTION OF THIS PLUME WILL LIKELY BE THE IMPETUS FOR INCREASING CONVECTION/TSTMS. AT THE SFC...THE MODIFIED ARCTIC COLD FRONT SHOULD BECOME QUASI-STATIONARY FROM SERN AR TO THE UPPER TX COAST AND SCNTRL TX THROUGH SUNDAY AFTN. PROSPECTS FOR WARM SECTOR TSTM DEVELOPMENT DO NOT APPEAR ROBUST. STRONG INSTABILITY WILL EXIST ACROSS DEEP S TX WHERE PRE-FRONTAL AIR MASS WILL BE CHARACTERIZED BY TEMPERATURES NEAR 80F AND DEW POINTS NEAR 68F. PRESENCE OF A CAP AND WEAK DEEP LAYER ASCENT...HOWEVER... SHOULD PRECLUDE SFC-BASED STORMS. JUST TO THE N OF THE FRONT... FORECAST SOUNDINGS SUGGEST THAT AVAILABLE CAPE WILL BE MINIMAL. THUS...DESPITE SUFFICIENT EFFECTIVE SHEAR FOR ORGANIZED STORMS...HAIL RISKS SEEM LOW ACROSS SCNTRL-ECNTRL TX. FINALLY... FARTHER EAST ACROSS PORTIONS OF THE MID-SOUTH...POOR LAPSE RATES ARE EXPECTED TO REMAIN IN PLACE AND UPDRAFTS SHOULD NOT BE PARTICULARLY STRONG DESPITE INCREASING VERTICAL SHEAR. ..RACY.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 12:39:01 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 07:39:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141242 SWODY1 SPC AC 141239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 AM CST SUN JAN 14 2007 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...S AND E TX NEWD INTO THE MID-SOUTH... THE UPPER LEVEL IMPULSE LOCATED ACROSS AZ IS EXPECTED TO EJECT ENEWD TO THE CNTRL PLAINS BY SUNDAY NIGHT AS A NEW SPEED MAX DROPS SEWD INTO THE SWRN DESERTS. ATTENDANT UPPER LEVEL JET OF 150+ KTS WILL PROPAGATE NEWD ALONG THE BASE OF THE TROUGH WITH THE ENTRANCE REGION SPREADING ACROSS THE SRN PLAINS. SUBTROPICAL MOISTURE PLUME WAS WELL-ESTABLISHED FROM SCNTRL TX NEWD INTO THE LWR OH/MS VLYS THIS MORNING PER 12Z RAOBS. AS AGEOSTROPHIC FORCING DEVELOPS IN RESPONSE TO THE UPSTREAM TROUGH...NWRN PORTION OF THIS PLUME WILL LIKELY BE THE IMPETUS FOR INCREASING CONVECTION/TSTMS. AT THE SFC...THE MODIFIED ARCTIC COLD FRONT SHOULD BECOME QUASI-STATIONARY FROM SERN AR TO THE UPPER TX COAST AND SCNTRL TX THROUGH SUNDAY AFTN. PROSPECTS FOR WARM SECTOR TSTM DEVELOPMENT DO NOT APPEAR ROBUST. STRONG INSTABILITY WILL EXIST ACROSS DEEP S TX WHERE PRE-FRONTAL AIR MASS WILL BE CHARACTERIZED BY TEMPERATURES NEAR 80F AND DEW POINTS NEAR 68F. PRESENCE OF A CAP AND WEAK DEEP LAYER ASCENT...HOWEVER... SHOULD PRECLUDE SFC-BASED STORMS. JUST TO THE N OF THE FRONT... FORECAST SOUNDINGS SUGGEST THAT AVAILABLE CAPE WILL BE MINIMAL. THUS...DESPITE SUFFICIENT EFFECTIVE SHEAR FOR ORGANIZED STORMS...HAIL RISKS SEEM LOW ACROSS SCNTRL-ECNTRL TX. FINALLY... FARTHER EAST ACROSS PORTIONS OF THE MID-SOUTH...POOR LAPSE RATES ARE EXPECTED TO REMAIN IN PLACE AND UPDRAFTS SHOULD NOT BE PARTICULARLY STRONG DESPITE INCREASING VERTICAL SHEAR. ..RACY/EVANS.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 15:45:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 10:45:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141548 SWODY1 SPC AC 141545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0945 AM CST SUN JAN 14 2007 VALID 141630Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG IMPULSE IN PROCESS OF LIFTING NEWD OUT OF WRN U.S. TROUGH POSITION AND WILL BE TRACKING ACROSS THE PLAINS INTO THE MID MS VALLEY THIS FORECAST PERIOD. WHILE THE LEADING EDGE OF THE SHALLOW ARCTIC AIR MASS HAS REACHED ALMOST TO UPR TX COAST WWD ACROSS FAR S TX...THERE REMAINS A STRONG SLY FLOW OF VERY MOIST AIR JUST ABOVE THE COLD DOME NWD INTO ERN OK/AR. MODELS IN REASONABLE AGREEMENT THAT A SURFACE LOW WILL FINALLY DEVELOP TONIGHT TO E OF THE SHALLOW COLD DOME OVER MID MS VALLEY WITH THE APPROACH OF THE UPPER SUPPORT NOW MOVING INTO SRN/CENTRAL PLAINS. ELEVATED THUNDERSTORMS HAVE RAPIDLY DEVELOPED THIS AM WRN OK INTO NWRN TX WITH THE MID LEVEL COOLING AND STRONG LARGE SCALE ASCENT ASSOCIATED WITH THE APPROACH OF THE S/WV TROUGH. WHILE THERE IS AN UNSEASONABLY MOIST AIR MASS IN PLACE ACROSS LWR MS INTO LOWER OH VALLEY...IT IS CHARACTERIZED BY WEAK LAPSE RATES AND LIMITED POTENTIAL FOR SURFACE HEATING WITH THE EXTENSIVE CLOUD COVER. POTENTIAL FOR SEVERE THUNDERSTORMS VERY LIMITED BOTH ELEVATED AND SURFACE BASED GIVEN THE WEAK LAPSE RATES AND INSTABILITY. HOWEVER PRIMARILY ELEVATED THUNDERSTORMS WILL EXPAND EWD ACROSS SRN PLAINS INTO MS VALLEY THRU THE FORECAST PERIOD. ..HALES.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 19:47:52 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 14:47:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141950 SWODY1 SPC AC 141948 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0148 PM CST SUN JAN 14 2007 VALID 142000Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY-TILTED UPPER TROUGH OVER THE ROCKIES WILL CONTINUE MOVING EWD...WHILE SURFACE COLD FRONT PRESSES SWD ACROSS THE S CENTRAL CONUS AS SURFACE WAVE SHIFTS NEWD TOWARD THE OH VALLEY. WARM ADVECTION ABOVE THIS BOUNDARY WILL YIELD A CONTINUED POTENTIAL FOR SHOWERS AND ISOLATED THUNDERSTORMS -- PARTICULARLY ACROSS TX WHERE MARGINAL ELEVATED INSTABILITY WILL PERSIST. ...PARTS OF OK/AR/ERN HALF OF TX/LA... LIGHTNING COVERAGE CONTINUES TO WANE ATTM...AS AREA OF ENHANCED PRECIPITATION -- APPARENTLY ASSOCIATED WITH SUBTLE VORT MAX EVIDENT IN IR IMAGERY MOVING NEWD ACROSS THE ARKLATEX -- SHIFTS NEWD. THOUGH OVERALL THUNDERSTORM COVERAGE SHOULD REMAIN LOW...SOME CONVECTIVE INCREASE MAY OCCUR ACROSS CENTRAL/S TX THE REMAINDER OF THE PERIOD...AS UPPER WAVE -- NOW MOVING ACROSS NWRN MEXICO TOWARD THE TX BIG BEND -- CONTINUES ENEWD. ..GOSS.. 01/14/2007  From swody1 at goshenarc.org Mon Jan 15 00:35:09 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 19:35:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150038 SWODY1 SPC AC 150035 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST SUN JAN 14 2007 VALID 150100Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL TX NEWD INTO THE OZARKS... WATER VAPOR IMAGERY AND RUC ANALYSIS PLACE ANOTHER UPPER LEVEL SPEED MAX MOVING ACROSS NRN MEXICO. CLOUD TOPS HAVE COOLED ACROSS CNTRL/NCNTRL TX WITH INCREASING PCPN RATES AS THIS IMPULSE TRANSLATES NEWD. PRIMARY SUB-TROPICAL MOIST PLUME HAS SHIFTED EWD...ARCING FROM THE UPPER TX COAST NEWD ACROSS CNTRL-NERN TX TO THE LWR OH VLY. 00Z MAF/DRT/CRP/OUN SOUNDINGS SHOW THAT DRY AIR HAS ADVECTED EWD IN THE H85-H5 LAYER WITH SHV RAOB EXHIBITING MUCH MORE SUBSTANTIAL PWATS. PRIND ANAFRONTAL CONVECTION WILL CONTINUE THROUGH LATE TONIGHT...STRONGEST OF WHICH SHOULD MOVE FROM CNTRL/NCNTRL TX EARLY THIS EVE INTO THE OZARKS LATER TONIGHT. SUFFICIENT ELEVATED CAPE EXISTS IN THIS CORRIDOR TO SUPPORT SPORADIC LIGHTNING/TSTMS MAINLY BEFORE 06Z AND ESPECIALLY ACROSS NCNTRL/NERN TX INTO SWRN AR. ..RACY.. 01/15/2007  From swody1 at goshenarc.org Mon Jan 15 05:26:07 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 00:26:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150529 SWODY1 SPC AC 150527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST SUN JAN 14 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SCNTRL-ERN TX... CONFLUENT FLOW DEVELOPING ACROSS THE PLAINS IN WAKE OF A PROGRESSIVE NRN STREAM WAVE WILL HELP ACCELERATE A BAROCLINIC ZONE EWD TO THE ERN SEABOARD...THE SERN STATES AND OFF THE WRN GULF COAST BY MONDAY NIGHT. A WIDESPREAD AREA OF PCPN WILL ACCOMPANY THE FRONT...WITH MORE ROBUST ANA-FRONTAL TYPE CONVECTION RELEGATED TO THE WRN GULF COASTAL AREA CLOSER TO STEEPER MID-TROPOSPHERIC LAPSE RATES. HERE...AGEOSTROPHIC RESPONSES TO SUBTLE SUB-TROPICAL IMPULSES WILL MAINTAIN A FLOW OF HIGHER THETA-E PARCELS ATOP THE FRONTAL INVERSION AND RESULT IN THERMODYNAMIC PROFILES SUFFICIENT FOR SPORADIC TSTMS. PROBABILITIES WILL BE HIGHEST PRE-18Z AND MAINLY ACROSS SCNTRL-ERN TX. ..RACY.. 01/15/2007  From swody1 at goshenarc.org Mon Jan 15 12:42:05 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 07:42:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151244 SWODY1 SPC AC 151242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 AM CST MON JAN 15 2007 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... THUNDERSTORM POTENTIAL WILL REMAIN QUITE LIMITED ACROSS THE NATION THROUGH THE PERIOD GIVEN THE DEARTH OF INSTABILITY FORECAST. HOWEVER...MOIST CONVECTION WILL PERSIST ACROSS CENTRAL TX WITHIN BROAD MID LEVEL MOIST PLUME. APPEARS INSTABILITY WILL REMAIN SUFFICIENT FOR ISOLATED LIGHTNING STRIKES WITH THIS ACTIVITY OVER PARTS OF CENTRAL TX WHERE 12Z DRT SOUNDING MAINTAINS WEAK ELEVATED INSTABILITY. ..EVANS.. 01/15/2007  From swody1 at goshenarc.org Tue Jan 16 00:33:41 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 19:33:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160036 SWODY1 SPC AC 160034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST MON JAN 15 2007 VALID 160100Z - 161200Z ...NO TSTM AREAS FORECAST... NRN COMPONENT OF POSITIVE-TILT LARGE SCALE TROUGH WILL CONTINUE DEVELOPING E FROM THE OH VLY/GRTLKS REGIONS THROUGH TONIGHT. AN EXTENSIVE SWATH OF PRIMARILY POST-FRONTAL PRECIPITATION CONTINUES FROM THE LWR MS VLY TO NEW ENGLAND. THIS WILL SPREAD E TOWARD THE MID-ATLANTIC COAST THROUGH 12Z TUE. DESPITE MODEST FORCING FOR ASCENT ACCOMPANYING THE UPPER TROUGH AND SFC FRONT...WEAK LAPSE RATES/MEAGER BUOYANCY WILL MITIGATE TSTMS TONIGHT. ..RACY/CARBIN.. 01/16/2007  From swody1 at goshenarc.org Tue Jan 16 05:02:36 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 16 Jan 2007 00:02:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160505 SWODY1 SPC AC 160503 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1103 PM CST MON JAN 15 2007 VALID 161200Z - 171200Z ...NO TSTM AREAS FORECAST... CONFLUENT FLOW ALOFT WILL CONTINUE TO BE FAVORABLE FOR THE MODIFIED CA/CP AIR MASS TO SURGE SEWD ACROSS THE SERN STATES AND INTO THE FL PENINSULA TUE AFT/NIGHT. A FEW SHOWERS MAY ACCOMPANY THE FRONT...BUT FCST SOUNDINGS IN THE WARM SECTOR ACROSS FL EXHIBIT WARM MID-TROPOSPHERIC TEMPERATURES THAT WILL PRECLUDE DEEP CONVECTION/ TSTMS. ELSEWHERE...TSTMS ARE NOT EXPECTED. ..RACY.. 01/16/2007  From swody1 at goshenarc.org Fri Jan 19 05:40:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 00:40:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190543 SWODY1 SPC AC 190540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST THU JAN 18 2007 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... LATE EVENING MODEL GUIDANCE CONTINUES TO SUGGEST UPPER LOW WILL BEGIN EJECTING EWD ACROSS THE NRN BAJA PENINSULA SHORTLY AFTER 12Z...THEN LIFT NEWD INTO SRN AZ BY THE END OF THE PERIOD. SUSTAINED ASCENT WITHIN EXIT REGION OF UPPER JET SHOULD MOISTEN PROFILES THROUGH A DEEP LAYER ACROSS THE SRN HALF OF AZ...WHILE LAPSE RATES STEEPEN WITHIN COOLING COLUMN. EVEN SO...FORECAST SOUNDINGS ONLY WEAKLY DESTABILIZE THIS REGION AND SUSPECT CONVECTION SHOULD GENERALLY REMAIN TOO SHALLOW FOR WIDESPREAD THUNDERSTORMS. MOST THUNDERSTORM ACTIVITY WILL BE CONCENTRATED SOUTH OF THE AZ BORDER...BUT ISOLATED LIGHTNING MAY EVOLVE TO THE NORTH-EAST OF THE MAIN UPPER LOW...ESPECIALLY DURING THE LATTER HALF OF THE PERIOD. ..DARROW.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 12:47:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 07:47:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191249 SWODY1 SPC AC 191247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST FRI JAN 19 2007 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... MORNING WATER VAPOR LOOPS SHOW CLOSED UPPER LOW OVER NORTHERN BAJA...WITH BROAD PLUME OF SUBTROPICAL MOISTURE EXTENDING ACROSS NORTHERN MEXICO INTO THE SOUTHERN PLAINS. MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE ONLY AREA WHERE SUFFICIENT DESTABILIZATION CAN OCCUR FOR A RISK OF THUNDERSTORMS WILL BE ACROSS PARTS OF AZ/NM. PROLONGED UVVS AHEAD OF UPPER LOW...COMBINED WITH STEEPENING LAPSE RATES WILL RESULT IN MARGINAL ELEVATED CAPE VALUES...DESPITE VERY LIMITED MOISTURE. SCATTERED SHOWERS AND ISOLATED LIGHTNING STRIKES ARE POSSIBLE FROM CENTRAL AZ THIS AFTERNOON...INTO WESTERN NM TONIGHT. NO SEVERE STORMS ARE FORECAST. ELSEWHERE...NO ORGANIZED THUNDERSTORM ACTIVITY IS FORECAST TODAY ACROSS THE NATION. ..HART.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 16:02:47 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 11:02:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191605 SWODY1 SPC AC 191602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST FRI JAN 19 2007 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... COLD CUT-OFF LOW CURRENTLY OVER NRN BAJA EXPECTED TO SHOW A GRADUAL INCREASE IN EWD MOTION AS HEIGHT FALLS MOVE INTO PAC NW. INCREASING MOISTURE IN STRONG SLY FLOW AHEAD OF LOW CENTER IS SPREADING N/NE INTO SRN AZ/NM. THE INSTABILITY SUFFICIENT FOR A THUNDER THREAT CURRENTLY LOCATED IN MEXICO WITH AND JUST TO E OF UPPER LOW. WITH THE COLD CORE LOW TRACKING ACROSS SERN CORNER OF AZ TONIGHT...A FEW THUNDERSTORMS WILL BE POSSIBLE EMBEDDED BOTH WITHIN THE PLUME OF MOISTURE AHEAD OF THE LOW AND THE STEEP LAPSE RATES WITH THE LOW TONIGHT. ..HALES.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 19:58:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 14:58:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 192001 SWODY1 SPC AC 191958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST FRI JAN 19 2007 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... MID AND UPPER LEVEL LOW SLOWLY DRIFTING SSEWD OVER NRN BAJA IS FORECAST TO ACCELERATE IN MORE OF AN ELY DIRECTION TONIGHT IN RESPONSE TO INCREASING HEIGHT FALLS FROM THE PACIFIC NW INTO GREAT BASIN. CYCLONICALLY CURVED PRECIPITATION BAND IS ONGOING AS OF 1930Z FROM THE SERN PART OF THE STATE WNWWD THROUGH THE PHX METRO TO BLH WITHIN ZONE OF DEEP LAYER FORCING FOR ASCENT AHEAD AND N OF UPPER LOW. HOWEVER...PRIMARY REGION OF DEEP...MOIST CONVECTION REMAINS CONFINED TO NEAR THE CENTER OF AND ALONG THE SWRN/SRN PERIPHERY OF CIRCULATION FROM JUST OFF THE BAJA COAST TO THE NRN GULF OF CA. PROXIMITY RUC SOUNDINGS INDICATE THAT MID LEVEL LAPSE RATES REMAIN QUITE WEAK /AOB 6.5 C PER KM/ OVER SERN INTO CNTRL AZ. WITH APPROACH OF UPPER LOW...EXPECT THAT THESE LAPSE RATES WILL STEEPEN...SUPPORTING POCKETS OF WEAK CONVECTIVE INSTABILITY AND AN ISOLATED THUNDER THREAT LATER THIS AFTERNOON AND TONIGHT. ..MEAD.. 01/19/2007  From swody1 at goshenarc.org Sat Jan 20 00:39:32 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 19:39:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200042 SWODY1 SPC AC 200039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST FRI JAN 19 2007 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... EARLY EVENING MODEL GUIDANCE SUGGESTS CENTER OF UPPER CIRCULATION IS LOCATED OVER THE NRN BAJA PENINSULA/NRN GULF OF CALIFORNIA...ABOUT 200 S OF YUM. THIS FEATURE WILL SOON EJECT ENEWD ACROSS NRN MEXICO TO NEAR THE AZ/NM/MEXICO BORDER BY THE END OF THE PERIOD. ROUGHLY 4 BANDS OF DEEP CONVECTION HAVE DEVELOPED WITHIN THE NERN QUAD OF THIS LARGE SCALE CIRCULATION INTO CNTRL PORTIONS OF AZ...WITH ISOLATED LIGHTNING NOW LIMITED TO THE TWO BANDS ACROSS NWRN MEXICO. EVEN SO...THIS ACTIVITY IS DECREASING IN INTENSITY AND NOW MOSTLY NEAR THE LOW CENTER. 00Z SOUNDING FROM TUS SUGGESTS THUNDER POTENTIAL WILL BE RELATIVELY LOW THE REST OF THE PERIOD AS INSTABILITY IS VERY WEAK AND BOUNDARY LAYER WILL SOON BEGIN TO COOL. ..DARROW.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 05:15:27 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 00:15:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200518 SWODY1 SPC AC 200515 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... WELL DEFINED UPPER LOW OVER NWRN MEXICO WILL FINALLY EJECT NEWD INTO THE TX PANHANDLE LATE IN THE PERIOD AS STRONG SPEED MAX DEVELOPS OVER THE SRN PLAINS REGION INTO CNTRL OK. THIS FEATURE WILL UNDOUBTEDLY ENHANCE LARGE SWATH OF PRECIPITATION...AND ELEVATED CONVECTION ACROSS PORTIONS OF THE SRN ROCKIES INTO THE HIGH PLAINS REGION...INVOF THE UPPER LOW. HOWEVER...SHALLOW NATURE OF THE ELEVATED CONVECTION SUGGESTS LIGHTNING POTENTIAL IS QUITE LOW WITH THIS FEATURE. FARTHER SOUTH...LOW LEVEL WARM ADVECTION WILL INCREASE MARKEDLY ACROSS THE UPPER TX COAST INTO SRN LA AS WEAK SFC WAVE FORMS OFFSHORE IN THE NWRN GULF OF MEXICO. HOWEVER...POOR MID LEVEL LAPSE RATES SUGGEST WEAK INSTABILITY ACROSS THIS REGION WILL RESULT IN SHOWERS INCAPABLE OF GENERATING LIGHTNING. ..DARROW.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 15:47:26 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 10:47:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201552 SWODY1 SPC AC 201549 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0949 AM CST SAT JAN 20 2007 VALID 201630Z - 211200Z ...NO TSTM AREAS FORECAST... SWRN CUT-OFF LOW NOW ON THE MOVE AND WILL TRACK FROM CURRENT LOCATION OVER SWRN NM NEWD ACROSS ERN KS LATER TONIGHT AS IT OPENS INTO A TROUGH. ALTHOUGH GULF MOISTURE IS BEING DRAWN NWD INTO SRN PLAINS AHEAD OF UPPER SYSTEM...WEAK LAPSE RATES AND EXTENSIVE CLOUD COVER WILL INHIBIT DEVELOPMENT OF INSTABILITY SUFFICIENT TO SUPPORT THUNDERSTORMS. STEEP MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER LOW AS IT MOVES ACROSS ERN NM/TX PANHANDLE LATER THIS AFTERNOON COULD SUPPORT SOME CONVECTIVE PRECIPITATION. HOWEVER OTHER THAN ISOLATED STRIKES...THUNDERSTORMS THREAT IS MINIMAL. ..HALES.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 19:37:41 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 14:37:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201942 SWODY1 SPC AC 201940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST SAT JAN 20 2007 VALID 202000Z - 211200Z ...NO TSTM AREAS FORECAST... ...SRN PLAINS... WATER VAPOR IMAGERY AND RUC OBJECTIVE FIELDS INDICATE VORTICITY MAXIMUM EJECTING NEWD ACROSS ERN NM/WRN TX IN ADVANCE OF PRIMARY MID/UPPER LEVEL LOW CURRENTLY OVER WRN/CNTRL NM. REGIONAL 12Z RAOBS AND 18Z SUPPLEMENTAL SOUNDINGS INDICATE THE EXISTENCE OF POOR LAPSE RATES EXCEPT INVOF MID-LEVEL COLD POOL /REF. 12Z TUS SOUNDING/ OVER ERN AZ. WHILE NO ORGANIZED THUNDER THREAT IS ANTICIPATED THROUGH 21/12Z...POTENTIAL WILL EXIST FOR ISOLATED LIGHTNING STRIKES WITHIN ZONE OF STRONG FORCING ASSOCIATED WITH LEAD VORTICITY MAXIMUM AS WELL AS WITH MAIN LOW CENTER WHERE STEEPER MID-LEVEL LAPSE RATES WILL BE COINCIDENT WITH MOIST ASCENT. ELSEWHERE...TEMPERATURE AND RESULTANT LAPSE RATE PROFILES ARE EXPECTED TO REMAIN WARM/WEAK WITHIN WARM CONVEYOR PRECIPITATION BAND WHICH WILL BECOME MORE EXPANSIVE OVER THE SABINE INTO LOWER MS VALLEYS OVERNIGHT. NO THUNDER IS FORECAST. ..MEAD.. 01/20/2007  From swody1 at goshenarc.org Sun Jan 21 00:38:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 19:38:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210043 SWODY1 SPC AC 210041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 PM CST SAT JAN 20 2007 VALID 210100Z - 211200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER TROUGH OVER THE WRN AND CENTRAL CONUS WILL MAKE SLOW EWD PROGRESS THROUGH THE END OF THE PERIOD...WHILE EMBEDDED/SMALLER-SCALE TROUGH MOVES ACROSS THE SRN PLAINS. A LARGE AREA OF MIXED WINTRY PRECIPITATION WILL CONTINUE ACROSS THE CENTRAL AND S CENTRAL CONUS...WHILE SPREADING EWD INTO THE MS VALLEY REGION OVERNIGHT. HOWEVER...LACK OF INSTABILITY SHOULD PRECLUDE ANY THREAT FOR THUNDERSTORMS. ..GOSS.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 05:56:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 00:56:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210601 SWODY1 SPC AC 210558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER TROUGH -- WHICH WILL INITIALLY CONSIST OF ONE FEATURE SHIFTING RAPIDLY NEWD TOWARD THE GREAT LAKES REGION AND THE OTHER DROPPING SSWWD TOWARD AZ -- WILL REMAIN OVER THE WEST THIS PERIOD. WITH TIME...THE ERN-MOST FEATURE WILL CONTINUE SHEARING NEWD...WHILE THE WRN FEATURE EVOLVES INTO A CLOSED LOW AS IT CROSSES AZ THROUGH THE PERIOD. AT THE SURFACE...MAIN FEATURE WILL BE A WEAK COLD FRONT...WHICH WILL MOVE SEWD ACROSS THE MID-SOUTH/LOWER MS VALLEY/SRN PLAINS THROUGH THE END OF THE PERIOD. THOUGH A LIGHTNING STRIKE OR TWO MAY OCCUR ACROSS THE DESERT SW NEAR THE EVOLVING UPPER LOW...SOMEWHAT GREATER THUNDER POTENTIAL SHOULD REMAIN LIMITED TO THE CENTRAL GULF COAST REGION. ...CENTRAL GULF COAST REGION AND VICINITY... MOISTENING BOUNDARY IS ANTICIPATED AHEAD OF WEAK/SEWD-MOVING COLD FRONT...THOUGH WEAK SHORT-WAVE RIDGING/SUBSIDENCE FORECAST ALOFT WILL CONTRIBUTE TO VERY WEAK LAPSE RATES. THIS SUGGESTS MINIMAL INSTABILITY...AND THEREFORE ONLY ISOLATED LIGHTNING STRIKES ARE EXPECTED THROUGH THE PERIOD. ..GOSS.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 12:43:09 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 07:43:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211248 SWODY1 SPC AC 211245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 AM CST SUN JAN 21 2007 VALID 211300Z - 221200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH REMAINS OVER THE CENTRAL UNITED STATES THIS MORNING...WITH INITIAL UPPER LOW LIFTING NORTHWARD INTO THE UPPER MS VALLEY WHILE A SECOND LOW DIGS SOUTHWARD INTO AZ. RELATIVELY DRY LOW LEVEL CONDITIONS ARE PRECLUDING ORGANIZED THUNDERSTORMS OVER MOST OF THE COUNTRY. THE ONE EXCEPTION WILL BE OVER THE CENTRAL GULF COAST REGION. ...CENTRAL GULF COAST REGION... MODEL GUIDANCE IS IN GENERAL AGREEMENT THAT WEAK SURFACE CYCLOGENESIS WILL OCCUR THIS AFTERNOON AND EVENING ALONG BAROCLINIC ZONE CURRENTLY OVER LA/MS. INCREASING SOUTHEASTERLY LOW LEVEL WINDS AHEAD OF BOUNDARY WILL HELP TO TRANSPORT MORE MOIST AND MARGINALLY UNSTABLE AIR MASS INTO PARTS OF SOUTHERN LA/MS/AL AND THE FL PANHANDLE /DEWPOINTS IN THE 50S TO NEAR 60F/. FORECAST SOUNDINGS IN THIS AREA SHOW NEAR MOIST-ADIABATIC LAPSE RATES AND ONLY VERY WEAK CAPE /GENERALLY LESS THAN 200 J/KG/. NEVERTHELESS...FORCING ALONG BOUNDARY MAY BE SUFFICIENT FOR CONTINUED SHOWERS AND ISOLATED THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. NO SEVERE STORMS ARE ANTICIPATED DUE TO LACK OF SUFFICIENT INSTABILITY. ...AZ... SCATTERED CONVECTION IS ALSO EXPECTED THIS AFTERNOON BENEATH COLD UPPER LOW OVER SOUTHERN AZ. FORECAST SOUNDINGS IN THIS AREA SUGGEST LOW-TOPPED SHOWERS ARE POSSIBLE...BUT POTENTIAL FOR MORE THAN AN ISOLATED LIGHTNING STRIKE IS TOO LOW TO OUTLOOK AT THIS TIME. ..HART.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 15:54:59 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 10:54:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211559 SWODY1 SPC AC 211557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0957 AM CST SUN JAN 21 2007 VALID 211630Z - 221200Z ...NO SVR TSTM AREAS FORECAST... THE REPLACEMENT COLD LOW CONTINUES TO SETTLE SWD THRU AZ THIS PERIOD AS LAST WEEKS CUT-OFF RAPIDLY BECOMES ABSORBED IN THE FAST FLOW ACROSS ERN U.S. A VERY MOIST RETURN FLOW GULF COAST STATES WILL PERSIST THRU TONIGHT...HOWEVER WEAK LAPSE RATE AND EXTENSIVE CLOUD COVER MINIMIZES THE DEVELOPMENT OF INSTABILITY SUFFICIENT TO SUPPORT ORGANIZED THUNDERSTORMS. WILL MAINTAIN A SMALL AREA OF THUNDER POTENTIAL ASSOCIATED WITH THE BAND OF LOW TOPPED CONVECTION NOW MOVING EWD ACROSS SERN LA INTO SERN MS. HOWEVER ANY LIGHTNING STRIKES EXPECTED TO BE LIMITED TO NEAR GULF COAST WHERE SOME WEAK CAPE IS POSSIBLE. WHILE STEEP LAPSE RATES UNDER DEVELOPING COLD LOW DROPPING SWD THRU AZ WILL LEAD TO CONVECTIVE SHOWERS THIS PM...LITTLE IF ANY LIGHTNING EXPECTED GIVEN THE VERY LIMITED MOISTURE AND INSTABILITY. ..HALES.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 19:47:23 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 14:47:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211952 SWODY1 SPC AC 211949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN JAN 21 2007 VALID 212000Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF COAST... A BAND OF RELATIVELY SHALLOW CONVECTION IS ONGOING THIS AFTERNOON FROM SERN MS INTO FAR SERN LA...FOCUSED AHEAD OF WEAK SURFACE LOW NOW OVER S-CNTRL MS AND ATTENDANT FRONT/CONFLUENCE LINE STRETCHING SWD THROUGH SERN LA. MORE RECENT CONVECTION HAS DEVELOPED OFF THE COAST OF THE FL PNHDL...NEAR AND TO THE S OF WARM FRONT SLOWLY LIFTING NWD. 12Z OBSERVED AND CURRENT RUC FORECAST SOUNDINGS INDICATE THAT MID-TROPOSPHERE IS RATHER WARM RELATIVE TO BOUNDARY LAYER TEMPERATURE/MOISTURE PROFILES WITH RESULTING POOR LAPSE RATES AND QUITE WEAK CONVECTIVE INSTABILITY. AS SUCH...EXPECT THAT MAJORITY OF CONVECTION WILL REMAIN TOO SHALLOW TO SUPPORT CHARGE SEPARATION/LIGHTNING ACTIVITY. FORECAST SOUNDINGS DO SUGGEST THAT SUFFICIENT LOW LEVEL MOISTENING AND MID-LEVEL COOLING MAY OCCUR OVERNIGHT TO SUPPORT AN INCREASING THREAT OF ISOLATED TSTMS...MAINLY ACROSS THE FL PNHDL. THEREFORE...GENERAL THUNDER LINE HAS BEEN MAINTAINED. ..MEAD.. 01/21/2007  From swody1 at goshenarc.org Mon Jan 22 00:39:16 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 19:39:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220044 SWODY1 SPC AC 220041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 PM CST SUN JAN 21 2007 VALID 220100Z - 221200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE/POSITIVELY-TILTED UPPER TROUGH WILL PERSIST FROM THE GREAT LAKES SWWD INTO THE DESERT SW...WHILE EMBEDDED UPPER LOW WILL CONTINUE DROPPING SWD ACROSS AZ INTO FAR NWRN MEXICO BY THE END OF THE PERIOD. INSTABILITY REMAINS VERY MINIMAL -- BOTH INVOF THE UPPER LOW IN AZ AS WELL AS IN THE SEASONABLY-MOIST BOUNDARY LAYER WHICH HAS ADVECTED NWD INTO THE CENTRAL/ERN GULF COAST REGION. THIS LACK OF INSTABILITY WILL CONTINUE TO LIMIT ANY POTENTIAL FOR LIGHTNING...BOTH ACROSS AZ -- WHERE 3 CG STRIKES HAVE BEEN OBSERVED THIS AFTERNOON...AND ACROSS THE CENTRAL AND ERN GULF COAST REGION -- WHERE NO LIGHTNING HAS YET BEEN DETECTED. THEREFORE...WILL NOT INCLUDE ANY 10% THUNDER LINES FOR THE REMAINDER OF THIS FORECAST PERIOD. ..GOSS.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 05:54:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 00:54:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220559 SWODY1 SPC AC 220557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... NRN AND SRN STREAM UPPER TROUGHS -- INITIALLY PHASED AS A POSITIVELY-TILTED FEATURE EXTENDING FROM ERN CANADA/THE UPPER GREAT LAKES SWWD INTO THE DESERT SW -- ARE FORECAST TO SEPARATE INTO TWO DISTINCT FEATURES WITH TIME. THE NRN STREAM TROUGH IS FORECAST TO MOVE EWD/SEWD ACROSS ERN CANADA/THE NERN CONUS...WHILE THE SRN STREAM CLOSED LOW MOVES SLOWLY SEWD ACROSS THE SWRN U.S./NWRN MEXICO. A LIGHTNING STRIKE OR TWO WILL BE POSSIBLE N OF THE U.S./MEXICO BORDER...WHILE THE POTENTIAL FOR A FEW STRIKES WILL ALSO EXIST ACROSS SERN GA/NRN AND CENTRAL FL AHEAD OF WEAK COLD FRONT. ...SERN GA/NRN AND CENTRAL FL... WEAK INSTABILITY IS FORECAST TO DEVELOP AHEAD OF SURFACE FRONT...WHERE SEASONABLY-MOIST BOUNDARY LAYER /DEWPOINTS IN THE 60S/ WILL EXIST. DEGREE OF INSTABILITY...AND CONVERGENCE ALONG FRONT SHOULD BE SUFFICIENT FOR WEAK CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. HOWEVER...THUNDER THREAT SHOULD REMAIN QUITE LIMITED DUE TO WEAK INSTABILITY -- AND THE FACT THAT THE EQUILIBRIUM LEVEL OF MOST UPDRAFTS SHOULD REMAIN BELOW THE -20 C LEVEL -- IN THIS CASE FORECAST TO BE AROUND 25000 FT AGL. ...SERN AZ/SWRN NM/FAR W TX... STEEP LAPSE RATES/COLD MID-LEVEL TEMPERATURES ACCOMPANYING THE UPPER TROUGH WILL EXTEND ACROSS PARTS OF AZ/NM/FAR W TX AND INTO NWRN MEXICO THIS PERIOD...POSSIBLY RESULTING IN VERY WEAK CAPE ACROSS PORTIONS OF THIS AREA. A LIGHTNING STRIKE OR TWO MAY OCCUR N OF THE U.S./MEXICO BORDER FROM SERN AZ EWD TO FAR W TX INVOF UPPER LOW...THOUGH GREATER THREAT SHOULD REMAIN S OF THE BORDER THROUGH THE PERIOD. ..GOSS.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 13:14:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 08:14:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221319 SWODY1 SPC AC 221316 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0716 AM CST MON JAN 22 2007 VALID 221300Z - 231200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH REMAINS OVER THE UNITED STATES TODAY...WITH A GENERALLY COLD/DRY AIR MASS PRECLUDING THUNDERSTORMS IN MOST AREAS. ONLY PORTIONS OF SOUTHERN GA AND THE FL PENINSULA...AS WELL AS PARTS OF SOUTHERN NM/FAR WEST TX WILL HAVE A THREAT OF THUNDERSTORMS TODAY. ...GA/FL... MOIST AND MARGINALLY UNSTABLE CONDITIONS WILL BE PRESENT THROUGHOUT THE DAY ACROSS PORTIONS OF SOUTHERN GA AND THE FL PENINSULA...WHERE SCATTERED SHOWERS ARE FORECAST. MODEL SOUNDINGS IN THIS REGION SHOW NEAR MOIST-ADIABATIC LAPSE RATES AND CAPE VALUES BELOW 1000 J/KG. A FEW THUNDERSTORMS WILL LIKELY OCCUR IN THIS PRE-FRONTAL ZONE THIS AFTERNOON AND EVENING. HOWEVER...WARM TEMPERATURES ALOFT... RELATIVELY WEAK CAPE VALUES...AND POOR LAPSE RATES SHOULD LIMIT UPDRAFT STRENGTH AND SEVERE POTENTIAL. ...NM/TX... COLD UPPER LOW OVER SOUTHERN AZ AND NORTHERN MEXICO THIS MORNING WILL MOVE VERY LITTLE THROUGH THE FORECAST PERIOD. RELATIVELY STEEP LAPSE RATES WILL RESULT IN MARGINAL AFTERNOON INSTABILITY OVER PARTS OF SOUTHERN NM AND FAR WEST TX. SIMILAR TO YESTERDAY OVER AZ...AN ISOLATED LIGHTNING STRIKE OR TWO CANNOT BE RULED OUT IN STRONGER LOW-TOPPED SHOWERS. HOWEVER...FORECAST SOUNDINGS SHOW A RELATIVELY COLD AND DRY THERMODYNAMIC PROFILE THAT IS NOT FAVORABLE FOR ORGANIZED THUNDERSTORM ACTIVITY. ..HART.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 15:44:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 10:44:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221549 SWODY1 SPC AC 221546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0946 AM CST MON JAN 22 2007 VALID 221630Z - 231200Z ...NO SVR TSTM AREAS FORECAST... FRONTAL BAND WILL CONTINUE SETTLING SEWD ACROSS NRN INTO CENTRAL FL PENINSULA THIS FORECAST PERIOD. WARM SECTOR AHEAD OF FRONT IS CHARACTERIZED BY A WARM...MOIST AND WEAKLY UNSTABLE AIR MASS. WITH LAPSE RATES AROUND 5.5 C/KM AND MLCAPES GENERALLY LESS THAN 500 J/KG...CONVECTIVE ACTIVITY EXPECTED TO REMAIN WEAK BOTH ALONG THE FRONT AND ACROSS NRN FL IN THE WARM SECTOR. CONVECTION BY MID AFTERNOON...WHEN SURFACE TEMPERATURES REACH INTO THE LOW 80S...SHOULD BE DEEP ENOUGH FOR A FEW THUNDERSTORMS. ..HALES.. 01/22/2007  From swody1 at goshenarc.org Sun Jan 28 00:40:24 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 27 Jan 2007 19:40:24 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280045 SWODY1 SPC AC 280042 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 PM CST SAT JAN 27 2007 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF COAST...INCLUDING FL... EVENING WATER VAPOR IMAGERY INDICATES MIGRATORY SHORT WAVE TROUGH OVER THE ARKLATEX WITH AN ASSOCIATED BELT OF 50-60 KT MID-LEVEL FLOW PRESENT ACROSS THE GULF COAST AND NRN GULF OF MEXICO. THIS SHORT WAVE TROUGH WILL CONTINUE EWD ACROSS THE REGION OVERNIGHT TO NEAR THE ATLANTIC COAST BY 28/12Z. IN THE LOW-LEVELS...ASSOCIATED SURFACE LOW OFF THE SERN LA COAST IS FORECAST TO DEVELOP GENERALLY EWD TOWARD THE FL BIG BEND...PRIOR TO REDEVELOPING E/NE OF JAX BY THE END OF THE PERIOD. ATTENDANT WARM FRONT CURRENTLY EXTENDING FROM THIS LOW EWD ACROSS THE NERN GULF OF MEXICO AND THE NRN FL PENINSULA MAY LIFT SLIGHTLY NWD. LARGE PRECIPITATION SHIELD ONGOING ACROSS ERN MS/AL/GA/FL PNHDL INTO THE N-CNTRL/NERN GULF OF MEXICO IS EXPECTED TO CONTINUE TONIGHT AHEAD OF UPPER TROUGH...DRIVEN LARGELY BY WAA/ISENTROPIC UPGLIDE ABOVE SHALLOW SURFACE INVERSION. WHILE MOST OF THIS ACTIVITY WILL REMAIN ELEVATED...POTENTIAL WILL EXIST FOR SURFACE-BASED OR NEAR SURFACE-BASED STORMS TO MOVE ONTO THE FL PENINSULA LATER TONIGHT NEAR OR TO THE S OF SLOWLY RETREATING WARM FRONT. HERE...FORECAST SOUNDINGS INDICATE THAT LAPSE RATES AND RESULTANT INSTABILITY WILL REMAIN QUITE WEAK /SBCAPES AOB 300-400 J PER KG/...HOWEVER BOTH LOW AND DEEP-LAYER SHEAR WILL INCREASE MARKEDLY. AS SUCH...SOME THREAT FOR AN ISOLATED...BRIEF TORNADO OR WIND GUST WILL EXIST WITH ANY MORE ORGANIZED STORMS MOVING ONSHORE. THIS THREAT WILL BE LIMITED BY THE WEAK INSTABILITY AND TENDENCY FOR STORMS TO BE SLIGHTLY ELEVATED. THEREFORE...ONLY LOW PROBABILITIES WILL BE MAINTAINED. ..MEAD.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 05:25:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 00:25:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280530 SWODY1 SPC AC 280528 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST SAT JAN 27 2007 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... ERN CONUS LONG WAVE TROUGH /ANCHORED BY VORTEX OVER HUDSON BAY/ WILL BE MAINTAINED THROUGH THE PERIOD AS A SERIES OF SHORT WAVE TROUGHS/VORTICITY MAXIMA TRANSLATE THROUGH MEAN PATTERN. THE LEAD IMPULSE /CURRENTLY MOVING THROUGH THE GULF COAST REGION/ WILL MOVE OFFSHORE INTO THE ATLANTIC EARLY IN THE DAY ONE PERIOD. AS THIS OCCURS...INTENSE...UPSTREAM SHORT WAVE TROUGH WILL DIG SEWD FROM THE MIDWEST THROUGH THE CNTRL/SRN APPALACHIANS...EVENTUALLY INTO THE WRN ATLANTIC BY MONDAY MORNING. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO LEAD SHORT WAVE TROUGH WILL DEVELOP NNEWD ALONG/JUST E OF THE GULF STREAM WITH SECONDARY...WEAKER CYCLOGENESIS OCCURRING LATER IN THE PERIOD OFF THE NC/VA COASTS WITH APPROACH OF UPSTREAM SYSTEM. COLD FRONT ASSOCIATED WITH INITIAL SURFACE LOW WILL PUSH SEWD THROUGH THE FL PENINSULA SUNDAY MORNING. ...FL... AS MENTIONED ABOVE...INITIAL SHORT WAVE TROUGH WILL QUICKLY MOVE OFFSHORE WITH ATTENDANT SURFACE FRONT PUSHING SEWD THROUGH THE PENINSULA DURING THE MORNING HOURS. PRE-FRONTAL BAND OF CONVECTION WITH EMBEDDED ISOLATED/SCATTED TSTMS WILL LIKELY BE ONGOING AT THE ONSET OF THE FORECAST PERIOD WITHIN RELATIVELY MOIST/WEAKLY UNSTABLE ENVIRONMENT. DESPITE RATHER STRONG TROPOSPHERIC WIND FIELDS...VEERED...PRE-FRONTAL FLOW IN THE LOW-LEVELS COUPLED WITH WEAK LAPSE RATES AND THE MARGINAL INSTABILITY ARE EXPECTED TO PRECLUDE A SEVERE WEATHER THREAT. ELSEWHERE...ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE FROM THE CNTRL CA COAST EWD TOWARD THE SIERRAS IN ASSOCIATION WITH MID LEVEL LOW ENTRENCHED IN REX BLOCK OVER THE FAR ERN PACIFIC. TSTM POTENTIAL APPEARS TOO LIMITED TO WARRANT ADDITIONAL THUNDER AREA. ..MEAD.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 12:57:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 07:57:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281301 SWODY1 SPC AC 281258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST SUN JAN 28 2007 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD MEAN TROUGH WILL REMAIN OVER ERN NOAM THIS PERIOD...DOWNSTREAM FROM REX BLOCK OVER THE NE PACIFIC. POTENT NRN STREAM SHORTWAVE NOW NEARING CHICAGO SHOULD CONTINUE SE INTO THE SRN APLCNS TONIGHT... BEFORE TURNING MORE E OFF THE MID ATLANTIC CST TONIGHT/EARLY MONDAY. AS THIS OCCURS...WEAKER SRN BRANCH IMPULSE NOW OVER SC WILL CONTINUE TO BE ABSORBED IN FAST CONFLUENT FLOW DOWNSTREAM FROM MIDWEST DISTURBANCE. AT LOWER LEVELS...MAIN SFC WAVE ASSOCIATED WITH SC TROUGH IS NOW FORMING E OF CHARLESTON. THIS WAVE SHOULD ACCELERATE NEWD THROUGH THE DAY AS TRAILING COLD FRONT PROGRESSES E/SE ACROSS THE CNTRL/SRN FL PENINSULA. ...S FL THROUGH MIDDAY... SHALLOW COLD FRONT...AND PREFRONTAL CONFLUENCE AXIS OVER THE KEYS... WILL BE FOCI FOR MODEST CONVECTIVE DEVELOPMENT TODAY AS BOUNDARY LAYER WARMS AHEAD OF THESE FEATURES. DEPTH/STRENGTH OF CONVERGENCE WILL BE LIMITED AS SFC WAVE OFF THE SC CST LIFTS NE AWAY FROM REGION. COUPLED WITH RELATIVELY WEAK LOW TO MID LEVEL LAPSE RATES...ANY THUNDER SHOULD REMAIN WIDELY SCTD TO ISOLATED. ...MID ATLANTIC CSTL WATERS THIS EVENING... SCTD TSTMS SHOULD DEVELOP RAPIDLY LATER THIS EVENING THROUGH EARLY MONDAY OFF THE DELMARVA CST AS ZONE OF STRONG ASCENT/MID LEVEL COOLING ASSOCIATED WITH IMPULSE NOW NEAR CHICAGO OVERSPREADS REGION. THIS ACTIVITY SHOULD REMAIN OVER THE GULF STREAM GIVEN DRY OVERLAND AIR MASS AND WEAK LOW LEVEL CONVERGENCE. ...CNTRL CA... ISOLATED LIGHTNING WILL BE POSSIBLE FROM THE CNTRL CA COAST E TOWARD THE SIERRA IN ASSOCIATION WITH MID LEVEL LOW ENTRENCHED IN REX BLOCK OVER THE ERN PACIFIC. TSTM POTENTIAL APPEARS TOO LIMITED TO WARRANT A CATEGORICAL THUNDER FCST IN THIS AREA. ..CORFIDI.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 16:10:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 11:10:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281615 SWODY1 SPC AC 281612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1012 AM CST SUN JAN 28 2007 VALID 281630Z - 291200Z ...NO TSTM AREAS FORECAST... ...SERN FL COASTAL WATERS TO OFF THE MID ATLANTIC COAST... BAND OF THUNDERSTORMS PRECEEDING SURFACE COLD FRONT NOW MOVING ACROSS SERN FL WILL CONTINUE SHIFTING EWD AWAY FROM THE CONUS THIS AFTERNOON. VEERED SURFACE FLOW AND LIMITED INSTABILITY WILL LIKELY PRECLUDE FURTHER THUNDERSTORM DEVELOPMENT AHEAD OF THE COLD FRONT. OFFSHORE THUNDERSTORM DEVELOPMENT SHOULD INCREASE LATER THIS EVENING AND OVERNIGHT OVER THE GULF STREAM WATERS OFF THE NC/VA COAST AS LARGE SCALE ASCENT INCREASES AHEAD OF NEXT MID LEVEL IMPULSE NOW MOVING OUT OF THE MID WEST. ..EVANS.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 19:30:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 14:30:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281934 SWODY1 SPC AC 281932 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0132 PM CST SUN JAN 28 2007 VALID 282000Z - 291200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... OFFSHORE FLOW ALONG THE ATLANTIC AND GULF COASTS IN WAKE OF COLD FRONT NOW MOVING S OF THE FL KEYS COMBINED WITH A COOL/STABLE AIR MASS ACROSS MUCH OF THE LOWER 48 STATES WILL PRECLUDE TSTM DEVELOPMENT THIS FORECAST PERIOD. OFFSHORE TSTM DEVELOPMENT...EAST OF VA/NC COAST...IS EXPECTED LATER THIS EVENING AND OVERNIGHT AS ASCENT/COOLER MID LEVEL TEMPERATURES ASSOCIATED WITH OH VALLEY SHORT WAVE TROUGH SPREAD EWD ATOP WARMER GULF WATERS. ..PETERS.. 01/28/2007  From swody1 at goshenarc.org Mon Jan 29 00:34:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 19:34:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290039 SWODY1 SPC AC 290036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0636 PM CST SUN JAN 28 2007 VALID 290100Z - 291200Z ...NO TSTM AREAS FORECAST... ...CA... 29/00Z OAK SOUNDING INDICATED THE PRESENCE OF STEEP LOW/MID LEVEL LAPSE RATES AND RESULTANT SBCAPES OF AROUND 500 J/KG. WATER VAPOR IMAGERY SUGGESTS THAT BETTER LARGE-SCALE FORCING ASSOCIATED WITH VORTICITY MAXIMUM ROTATING AROUND PARENT UPPER LOW IS CURRENTLY TRANSLATING WWD INTO THE PACIFIC. ONSET OF NOCTURNAL RADIATIONAL COOLING IS EXPECTED TO RESULT IN A DECREASE OF THESE LAPSE RATES IN THE LOW LEVELS...WHICH SHOULD LIMIT ANY ORGANIZED TSTM THREAT OVERNIGHT. ELSEWHERE...TSTMS ARE FORECAST TO BECOME INCREASINGLY NUMEROUS TONIGHT OFF THE MIDDLE ATLANTIC COAST AS STRONG SHORT WAVE TROUGH /CURRENTLY MOVING THROUGH THE APPALACHIANS/ ACTS ON UNSTABLE...PRE-FRONTAL AIR MASS. ..MEAD.. 01/29/2007  From swody1 at goshenarc.org Mon Jan 29 05:03:43 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 29 Jan 2007 00:03:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290508 SWODY1 SPC AC 290506 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 PM CST SUN JAN 28 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... AMPLIFIED LONG WAVE PATTERN WILL CONTINUE THROUGH THE DAY ONE PERIOD...CHARACTERIZED BY REX BLOCK OVER THE FAR ERN PACIFIC AND BROAD CYCLONIC FLOW GENERALLY E OF THE ROCKIES. LOW LATITUDE SHORT WAVE TROUGH /CURRENTLY NEAR 116W AND 21N/ IS FORECAST TO TRANSLATE ACROSS MEXICO INTO THE NWRN GULF OF MEXICO BY TUESDAY MORNING. IN THE LOW-LEVELS...SURFACE ANTICYCLONE INITIALLY OVER THE CNTRL GULF COAST WILL WEAKEN AS IT SHIFTS EWD. WEAK CYCLOGENESIS IS EXPECTED TO OCCUR OVER THE NWRN GULF COAST TONIGHT WITH APPROACH OF ABOVEMENTIONED SHORT WAVE TROUGH. INTENSIFYING SLY LLJ IN ADVANCE OF THIS SYSTEM WILL SUPPORT AN INCREASE IN LOW-LEVEL MOISTURE ACROSS THE WRN GULF BASIN WITH CONVECTION BECOMING INCREASINGLY LIKELY TONIGHT ALONG THE TX COAST INTO THE LOWER SABINE RIVER VALLEY. FORECAST SOUNDINGS INDICATE THAT CORRESPONDING THERMAL PROFILES WILL REMAIN RELATIVELY WARM WITH CONVECTION LIKELY TOO SHALLOW TO SUPPORT LIGHTNING. A GREATER THREAT OF EMBEDDED TSTMS WILL EXIST OFFSHORE WHERE INSTABILITY AND RESULTING UPDRAFT DEPTH WILL BE GREATER. ..MEAD.. 01/29/2007  From swody1 at goshenarc.org Wed Jan 31 00:28:57 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 30 Jan 2007 19:28:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310033 SWODY1 SPC AC 310031 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 PM CST TUE JAN 30 2007 VALID 310100Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SRN CA COAST... MID AND UPPER LEVEL LOW OFF THE COAST IS FORECAST TO PIVOT MORE SEWD OVERNIGHT IN RESPONSE TO APPROACH OF UPSTREAM SYSTEM OVER NRN CA/NWRN NV. PROXIMITY OF ASSOCIATED MID-LEVEL COLD POOL WILL CONTINUE TO MAINTAIN MODERATELY STEEP LAPSE RATES AND RESULTANT WEAK CONVECTIVE INSTABILITY. THUS...THREAT OF ISOLATED THUNDER WILL LIKELY PERSIST THROUGH 31/12Z. ..MEAD.. 01/31/2007  From swody1 at goshenarc.org Mon Jan 1 00:54:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 31 Dec 2006 19:54:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010058 SWODY1 SPC AC 010056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST SUN DEC 31 2006 VALID 010100Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... CLOSED UPPER LOW...NOW CENTERED OVER MID MS VALLEY...IS EXPECTED TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS NEWD INTO THE GREAT LAKES REGION OVERNIGHT. MEANWHILE...PROGRESSIVE UPSTREAM SHORT WAVE TROUGH WILL DIG SEWD INTO THE MS VALLEY...MAINTAINING ELONGATED UPPER TROUGH ALONG THE MS VALLEY IN WAKE OF EJECTING UPPER LOW. AT THE SURFACE...AREA OF LOW PRESSURE LOCATED OVER SWRN WI WILL TRACK NEWD INTO THE UPPER GREAT LAKES TONIGHT...AS TRAILING COLD FRONT SPREADS EWD AND SHOULD EXTEND FROM THE LOW ACROSS THE LOWER GREAT LAKES AND CENTRAL APPALACHIANS SWWD TO THE NERN GULF. ...NERN IL/NRN IND TO SRN LOWER MI... ASCENT ALONG LEADING EDGE OF UPPER LOW/VORTEX COMBINED WITH STEEPENING LAPSE RATES PER MID LEVEL COOLING ATOP LOW LEVEL THERMAL RIDGE ARE EXPECTED TO MAINTAIN ONGOING ERN IL TSTM CLUSTER AS THE UPPER LOW TRACKS NE TOWARD THE GREAT LAKES REGION. FOR ADDITIONAL INFORMATION ABOUT THIS ACTIVITY AND ATTENDANT ISOLATED SEVERE THREAT...PLEASE REFER TO SPC MESOSCALE DISCUSSION 0001. ...NRN FL/SERN GA NWD TO ERN TN/WRN NC/SWRN VA... UPPER LEVEL DIFFLUENT FLOW REGIME LOCATED E AND SE OF UPPER LOW IS EXPECTED TO MAINTAIN TWO ONGOING AREAS OF CONVECTION...ONE OVER SERN GA/NRN FL AND THE SECOND ALONG THE COLD FRONT FROM NRN GA NWD INTO UPPER OH VALLEY. AIR MASS IN ADVANCE OF SERN GA/NWRN FL CONVECTIVE LINE IS MARGINALLY UNSTABLE...WITH EFFECTIVE BULK SHEAR VALUES OF 35-45 KT REMAINING FAVORABLE FOR SOME ORGANIZATION AND ATTENDANT LOW PROBABILITY FOR PRIMARILY AN ISOLATED DAMAGING WIND GUST. FARTHER N...FORCING SHOULD REMAIN SUFFICIENT ALONG THE COLD FRONT FOR ADDITIONAL CONVECTION AND A FEW EMBEDDED TSTMS ACROSS PARTS OF THE SRN AND CENTRAL APPALACHIANS. HOWEVER...WEAK LAPSE RATES SHOULD PRECLUDE A SEVERE WIND THREAT FROM NRN GA/ERN TN INTO SWRN VA/WRN NC THIS EVENING. ..PETERS.. 01/01/2007  From swody1 at goshenarc.org Wed Jan 3 16:27:08 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 11:27:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031631 SWODY1 SPC AC 031629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST WED JAN 03 2007 VALID 031630Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...TX... UPPER LOW OVER NORTHERN MEXICO IS FORECAST TO TRACK SLOWLY EASTWARD TODAY...AND INTO SOUTHWEST TX OVERNIGHT. MEANWHILE...LARGE SCALE DIFFLUENT FLOW PATTERN AND UPWARD FORCING WILL CONTINUE TO OVERSPREAD MUCH OF TX THROUGH THE FORECAST PERIOD. LOW LEVEL CYCLOGENESIS IS EXPECTED TO OCCUR ALONG THE MIDDLE TX GULF COAST THIS AFTERNOON AND EVENING...WITH MODELS SUGGESTING THAT SURFACE LOW WILL LIE VERY NEAR THE COAST. AIR MASS JUST OFFSHORE CONTINUES TO SLOWLY MODIFY WITH DEWPOINTS IN THE MID/UPPER 60S LIKELY OVERNIGHT. THIS WILL RESULT IN AT LEAST MARGINAL SURFACE-BASED INSTABILITY IN THE WARM SECTOR OF THE LOW /MLCAPE OF 300-500 J/KG/. IF WARM SECTOR CAN MOVE INLAND...VERTICAL SHEAR PROFILES WOULD BE FAVORABLE FOR SUPERCELL STORMS AND POSSIBLE TORNADOES. THIS CONDITIONAL THREAT APPEARS VERY LIMITED IN TEMPORAL AND AREAL EXTENT...SO WILL ONLY MAINTAIN LOW SEVERE PROBABILITIES. GUSTY WINDS AND HAIL WOULD ALSO BE POSSIBLE WITH STRONGER STORMS OVER SOUTH AND SOUTHEAST TX OVERNIGHT. ELSEWHERE...SCATTERED THUNDERSTORMS ARE EXPECTED ONCE AGAIN TODAY OVER THE FL PENINSULA WHERE MOIST AND MODERATELY UNSTABLE AIR MASS IS PRESENT. ISOLATED LIGHTNING STRIKES WILL ALSO BE POSSIBLE THROUGH THE DAY ALONG THE COAST OF WA. NO ORGANIZED SEVERE STORMS ARE EXPECTED IN THESE AREAS. ..HART.. 01/03/2007  From swody1 at goshenarc.org Wed Jan 3 19:52:40 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 14:52:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031956 SWODY1 SPC AC 031954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST WED JAN 03 2007 VALID 032000Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE...LOW-AMPLITUDE WAVE TRAIN WILL CONTINUE TO CHARACTERIZE NEARLY ZONAL NRN STREAM FLOW FROM PACIFIC NW EWD ACROSS GREAT LAKES AND NEW ENGLAND. SRN STREAM CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NWRN MEX -- IS FCST TO PIVOT ENEWD ACROSS BIG BEND REGION OF SW TX AND ADJACENT SERRANIAS DEL BURRO RANGE OF NRN MEX. AS ASSOCIATED MID-UPPER TROUGH APCHS S TX AND NWRN GULF...SFC CYCLOGENESIS IS FCST OFFSHORE BRO...INVOF INFLECTION POINT ON SFC FRONT. THIS LOW SHOULD LIFT NEWD TOWARD UPPER TX COAST...AND MAY REACH COAST AT OR SHORTLY AFTER END OF PERIOD. ...S TX... SCATTERED TO WIDELY SCATTERED ELEVATED TSTMS ALREADY ARE EVIDENT FROM N-CENTRAL MEX NEWD ACROSS PORTIONS SWRN...CENTRAL AND E TX. ERN-MOST OF THIS ACTIVITY IS OCCURRING ALONG FARTHEST INLAND AND MOST HIGHLY ELEVATED REACHES OF LOW LEVEL WAA/MOIST ADVECTION REGIME -- WHICH WILL SHIFT ACROSS PORTIONS ARKLATEX REGION TO LOWER MS VALLEY THROUGH REMAINDER PERIOD. MEANWHILE...AVAILABLE BUOYANCY ALOFT AND OVERALL CONVECTIVE COVERAGE EACH WILL INCREASE ACROSS MUCH OF S TX AS MOISTURE CONTINUES TO INCREASE ABOVE SFC...LAPSE RATES STRENGTHEN AS LARGE SCALE ASCENT INCREASES AHEAD OF UPPER LOW...AND ISENTROPIC ASCENT RAISES PARCELS TO LFC. EFFECTIVE SHEAR PROFILES WILL BECOME FAVORABLE FOR SOME STORMS TO ROTATE ALOFT...ENHANCING HAIL POTENTIAL. AIR MASS ALONG AND S OF MARINE FRONT -- NE OF SFC LOW -- WILL BE CHARACTERIZED BY ENLARGED LOW LEVEL HODOGRAPHS..SFC DEW POINTS MID 60S TO NEAR 70 F...AND ENOUGH SFC THETAE TO SUPPORT MLCAPES 500-1000 J/KG. MOST OF THIS AIR MASS SHOULD REMAIN OFFSHORE...HOWEVER CONDITIONAL TORNADO AND DAMAGING WIND RISK EXISTS LATE TONIGHT NEAR MID/UPPER TX COAST...BASED ON MRGL POTENTIAL FOR MARINE FRONT TO REACH SHORE BEFORE 4/12Z. ..EDWARDS.. 01/03/2007  From swody1 at goshenarc.org Thu Jan 4 00:48:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 03 Jan 2007 19:48:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040052 SWODY1 SPC AC 040050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 PM CST WED JAN 03 2007 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...S AND SERN TX COASTAL AREA... A SURFACE FRONT EXTENDS FROM A WEAK LOW JUST OFF THE S TX COAST EWD THROUGH THE NRN GULF OF MEXICO. AN UPPER LOW OVER NRN MEXICO WILL ADVANCE SLOWLY EAST TONIGHT REACHING SWRN TX BY THE END OF THIS PERIOD. SLY LOW LEVEL JET WILL INTENSIFY OVER CNTRL AND ERN TX WITHIN ZONE OF UPPER DIVERGENCE AND LARGE SCALE ASCENT DOWNSTREAM FROM THE UPPER LOW. THIS WILL MAINTAIN ISENTROPIC ASCENT AND A FAVORABLE ENVIRONMENT FOR STORMS TO CONTINUE DEVELOPING OVERNIGHT. THE BOUNDARY LAYER N OF SURFACE FRONT IS STABLE...SO STORMS WILL REMAIN ELEVATED MUCH OF THE REST OF THIS PERIOD. AS THE LOW LEVEL JET INTENSIFIES...WRN PORTION OF THE BOUNDARY WILL BEGIN TO LIFT NWD THROUGH THE NWRN GULF...POSSIBLY REACHING THE SERN TX COAST TOWARD THE END OF THIS PERIOD. AS THIS OCCURS THE BOUNDARY LAYER WILL DESTABILIZE AND STORMS MAY BECOME CLOSE ENOUGH TO SURFACE BASED TO POSE A SEVERE THREAT. LOW LEVEL AND DEEP LAYER SHEAR PROFILES WILL REMAIN FAVORABLE FOR ORGANIZED STORMS INCLUDING SUPERCELLS WITH ANY SURFACE BASED STORMS. PRIMARY THREAT WILL BE AN ISOLATED TORNADO OR DAMAGING WIND GUST CONDITIONAL UPON SUFFICIENT BOUNDARY LAYER DESTABILIZATION. GIVEN THE FRONT IS EXPECTED TO REMAIN OFFSHORE UNTIL NEAR THE END OF THIS PERIOD...THREAT DOES NOT APPEAR SUFFICIENT TO WARRANT MORE THAN 5% PROBABILITIES AT THIS TIME. ..DIAL.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 05:33:16 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 00:33:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040537 SWODY1 SPC AC 040535 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CST WED JAN 03 2007 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EXTREME SERN TX THROUGH THE CNTRL GULF COASTAL AREA... ...NWRN THROUGH CNTRL GULF COASTAL AREA... UPPER LOW OVER NRN MEXICO WILL EJECT NEWD THROUGH CNTRL AND ERN TX TODAY REACHING THE LOWER MS VALLEY TONIGHT AS A POSITIVELY TILTED UPPER TROUGH MOVES ONTO THE W COAST. A 50 TO 60 KT LOW LEVEL JET WILL SHIFT SLOWLY EWD THROUGH THE LOWER MS VALLEY WITHIN ZONE OF HEIGHT FALLS AND ASCENT DOWNSTREAM FROM THE UPPER LOW. THE STRONG SLY LOW LEVEL JET SHOULD CONTRIBUTE TO NWD ADVANCE OF WARM FRONT OVER THE NWRN GULF. BY LATE MORNING OR MID DAY THIS FRONT SHOULD EXTEND EWD ALONG THE LA COAST FROM A SURFACE LOW IN SWRN LA WITH A COLD FRONT EXTENDING SWD FROM THE LOW THROUGH THE WRN GULF. THUNDERSTORMS WILL CONTINUE WITHIN BELT OF ASCENT E OF UPPER LOW AND SHIFT THROUGH ERN TX AND THE LOWER MS VALLEY. MUCH OF THE CONVECTION WILL REMAIN ELEVATED. HOWEVER...AS THE WARM FRONT APPROACHES THE COAST...NWD ADVECTION OF UPPER 60S DEWPOINTS SHOULD CONTRIBUTE TO BOUNDARY LAYER DESTABILIZATION. MODEST MID LEVEL LAPSE RATES AND LIMITED SURFACE HEATING SHOULD RESULT IN MARGINAL INSTABILITY WITH MUCAPE AOB 500 J/KG. AS DEWPOINTS INCREASE AND THE BOUNDARY LAYER DESTABILIZES...STORMS MAY BECOME CLOSE ENOUGH TO SURFACE BASED TO POSE A SEVERE THREAT FROM EXTREME SERN TX INTO SRN LA...AND THE BOOTHEEL OF MS. LOW LEVEL HODOGRAPHS AND CLOUD LAYER SHEAR WILL SUPPORT ORGANIZED STORMS INCLUDING EMBEDDED SUPERCELLS WITH ANY SURFACE BASED ACTIVITY. PRIMARY THREATS WILL BE ISOLATED DAMAGING WIND AND AN ISOLATED TORNADO OR TWO. ..DIAL.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 12:28:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 07:28:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041232 SWODY1 SPC AC 041230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0630 AM CST THU JAN 04 2007 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM SRN LA INTO THE WRN FL PANHANDLE... ...NRN GULF COAST TODAY INTO EARLY TONIGHT... A CLOSED MID LEVEL LOW NEAR DEL RIO TX THIS MORNING WILL MOVE GENERALLY EWD OVER CENTRAL/SE TX TODAY...REACHING THE LOWER MS VALLEY TONIGHT...AS AN UPSTREAM WAVE DIGS ESEWD FROM THE PAC COAST TO THE SRN GREAT BASIN. AT THE SURFACE...A WEAK WAVE NEAR THE UPPER TX COAST WILL DEVELOP NEWD/INLAND ACROSS SW/CENTRAL LA IN ADVANCE OF THE TX MID LEVEL TROUGH. A WARM FRONT WILL ALSO LIFT NWD ACROSS THE N CENTRAL/NE GULF STATES ALLOWING A MOIST MARITIME AIR MASS /BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S/ TO SPREAD INLAND. THIS MOISTURE WILL CONTRIBUTE TO AT LEAST WEAK INSTABILITY TODAY ALONG THE I-10 CORRIDOR FROM LA TO THE FL PANHANDLE. THE MAGNITUDE OF THE INSTABILITY...HOWEVER...WILL BE LIMITED BY RATHER POOR MID LEVEL LAPSE RATES. A BROAD SWATH OF RAIN/EMBEDDED THUNDERSTORMS IS DEVELOPING EWD/NEWD ACROSS THE NW GULF AND E TX IN ADVANCE OF THE MID LEVEL TROUGH. THE CONVECTION INLAND IS ELEVATED THIS MORNING...AND WILL NOT LIKELY BECOME SURFACE-BASED OVER LAND UNTIL BOUNDARY LAYER DEWPOINTS INCREASE TO THE MID-UPPER 60S. ONCE LOW-LEVEL MOISTENING BECOMES SUFFICIENT BY ABOUT 18Z...VERTICAL SHEAR WILL BE FAVORABLE FOR SUPERCELLS...ESPECIALLY ALONG THE RETREATING WARM FRONT. THE COMBINATION OF WEAK INSTABILITY/MOIST PROFILES AND STRONG LOW-LEVEL SHEAR COULD SUPPORT A COUPLE OF TORNADOES THIS AFTERNOON INTO EARLY TONIGHT...ALONG WITH THE THREAT FOR ISOLATED DAMAGING WINDS WITH BOW ECHO STRUCTURES EMBEDDED IN THE LARGER CONVECTIVE BAND. ..THOMPSON.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 16:19:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 11:19:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041621 SWODY1 SPC AC 041618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1018 AM CST THU JAN 04 2007 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS VALLEY AND CENTRAL GULF COAST REGION... ...LOWER MS VALLEY... PROGRESSIVE UPPER LOW OVER TX IS FORECAST TO CONTINUE TO MOVE EASTWARD AND INTO THE LOWER MS VALLEY BY 05/12Z. THE ASSOCIATED SURFACE LOW...NOW NEAR THE MOUTH OF THE SABINE RIVER...WILL DEVELOP NORTHEASTWARD ACROSS LA AND INTO NORTHERN MS. STRONG LARGE SCALE FORCING FOR ASCENT ACROSS THE LOWER MS VALLEY...COUPLED WITH INCREASING LOW LEVEL MOISTURE AND MARGINAL INSTABILITY...WILL AID IN THE THREAT FOR SCATTERED THUNDERSTORMS THROUGHOUT THE FORECAST PERIOD FROM LA/AR INTO THE SOUTHEAST STATES. RICH LOW LEVEL MOISTURE REMAINS OFF THE LA COAST AT THIS TIME...AND EXTENT OF NORTHWARD PENETRATION IS UNCERTAIN. HOWEVER...FAVORABLE VERTICAL SHEAR PROFILES WILL SUPPORT A RISK OF SUPERCELL STORM STRUCTURES IF SUFFICIENT MOISTURE CAN BE TRANSPORTED INLAND. GUSTY WINDS AND ISOLATED TORNADOES WOULD BE THE MAIN THREATS. REFER TO MCD NUMBER 5 FOR FURTHER DETAILS. A MORE ORGANIZED SQUALL LINE WILL BE POSSIBLE THIS EVENING AND TONIGHT ACROSS PARTS OF MS/AL AS MAIN UPPER TROUGH ROTATES EASTWARD. CONDITIONAL RISK OF DAMAGING WINDS AND PERHAPS A TORNADO WILL CONTINUE WITH THIS ACTIVITY...IF SUFFICIENT SURFACE-BASED INSTABILITY IS PRESENT. ..HART.. 01/04/2007  From swody1 at goshenarc.org Thu Jan 4 19:51:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 14:51:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041955 SWODY1 SPC AC 041952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0152 PM CST THU JAN 04 2007 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE WRN/CNTRL GULF COASTAL AREA... ...CNTRL/WRN GULF COASTAL AREA... WATER VAPOR IMAGERY SUGGESTS THAT THE CNTRL TX UPPER LOW WAS BEGINNING TO EJECT ENEWD IN AN INCREASINGLY NEGATIVE TILT ORIENTATION. DIVERGENCE/DIFFLUENT REGIME AHEAD OF THIS SYSTEM WAS SUPPORTING A WIDESPREAD AREA OF CONVECTION ACROSS THE WRN GULF COASTAL AREA NWD INTO THE MID-SOUTH. WEAK CYCLOGENESIS WAS OCCURRING OVER NWRN LA AND THE 1010 HPA SFC LOW VCNTY KSHV SHOULD MIGRATE NEWD TOWARD THE KMEM VCNTY LATER THIS EVE. JUST ABOVE THE SFC...A STRONG H9-H8 SLY LLJ EXISTED JUST AHEAD OF A WEAK FRONT FROM SRN LA INTO NWRN MS. BOUNDARY LAYER HAS GRADUALLY MODIFIED WITH A WARM FRONT DEVELOPING ACROSS SRN LA VCNTY KPOE EWD TO JUST S OF THE KMSY AREA. TO THE S OF THE FRONT...TEMPERATURES/DEW POINTS HAVE WARMED TO NEAR 70/MID 60S DEG F RESPECTIVELY. MODIFIED 18Z SLIDELL RAOB SUGGESTS THAT SFC-BASED TSTMS WILL BE POSSIBLE THROUGH THIS EVE...PRIMARILY ACROSS ERN LA AND EXTREME SRN PARTS OF MS/AL WHERE MLCAPES WILL APPROACH 500 J PER KG. ANY STORM THAT DEVELOPS ALONG/S OF THE WARM FRONT WILL EXIST IN DEEP LAYER SHEAR OF AROUND 50 KTS AND SUPERCELLS WILL REMAIN POSSIBLE. THOUGH DAMAGING WINDS SHOULD BE THE PRIMARY THREAT...AS STORMS APPROACH AND CROSS OVER THE WARM FRONT...SFC-BASED STORMS DEVIATING TO THE RIGHT OF THE MEAN FLOW WILL OBTAIN 0-1KM SRH IN EXCESS OF 250 MS/S2. THUS...A BRIEF TORNADO MAY ALSO OCCUR. THESE SEVERE THREATS WILL EXTEND E INTO THE EXTREME WRN FL PNHDL BY 12Z. FARTHER N...THE COLUMN WILL CONTINUE TO DESTABILIZE THROUGH THE NIGHT ACROSS CNTRL/NRN PORTIONS OF MS/AL AS WARM/MOIST ADVECTION OCCUR. TSTMS THIS FAR N WILL LIKELY BE ROOTED ABOVE THE SFC...MITIGATING THREATS FOR DAMAGING WINDS OR TORNADOES. ..RACY.. 01/04/2007  From swody1 at goshenarc.org Fri Jan 5 00:38:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 04 Jan 2007 19:38:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050042 SWODY1 SPC AC 050040 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 PM CST THU JAN 04 2007 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL GULF COASTAL AREA... ...CNTRL GULF COASTAL AREA... PROGRESSIVE UPPER LOW OVER ERN TX WILL EJECT ENEWD INTO THE LOWER MS VALLEY TONIGHT. A 40 TO 50 KT SLY LOW LEVEL JET WILL PERSIST WITHIN THE ZONE OF UPPER DIVERGENCE AND ASCENT JUST DOWNSTREAM FROM THE SHORTWAVE TROUGH AND SHIFT EWD THROUGH THE SERN STATES. A WARM FRONT EXTENDS FROM A SURFACE LOW OVER LA EWD THROUGH SRN MS...SRN AL AND INTO SRN GA. A COLD FRONT EXTENDS SWD FROM THE LOW THROUGH SERN LA INTO THE NWRN GULF. BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 60S HAVE SPREAD INLAND NEAR AND S OF THE WARM FRONT. THE SLY LOW LEVEL JET MAY SUPPORT A NWD ADVANCE OF THE WARM FRONT OVERNIGHT...ALLOWING THE MOIST AND MARGINALLY UNSTABLE WARM SECTOR TO SPREAD FARTHER INLAND. BAND OF THUNDERSTORMS WILL PERSIST WITHIN ZONE OF DEEP LAYER ASCENT ALONG AND JUST AHEAD OF THE COLD FRONT AND SHIFT EWD OVERNIGHT. STORMS NEAR AND S OF THE WARM FRONT WILL REMAIN CLOSE ENOUGH TO SURFACE BASED TO MAINTAIN A SEVERE THREAT. LARGE LOW LEVEL HODOGRAPHS AND FAVORABLE DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS INCLUDING BOW ECHOES AND SUPERCELLS. ISOLATED TORNADOES AND DAMAGING WIND WILL REMAIN THE PRIMARY THREATS. ..DIAL.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 05:33:51 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 00:33:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050537 SWODY1 SPC AC 050535 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 PM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE SERN STATES...NRN FL INTO THE ERN CAROLINAS... ...SERN U.S. THROUGH ERN CAROLINAS... SHORTWAVE TROUGH NOW MOVING INTO THE MS VALLEY WILL EJECT NE THROUGH THE REMAINDER OF THE SERN STATES FRIDAY THROUGH FRIDAY NIGHT AND SLOWLY DEAMPLIFY. A 40 TO 50 KT SLY LOW LEVEL JET WILL SHIFT EWD THROUGH THE SERN U.S. IN ADVANCE OF THIS FEATURE DURING THE DAY AND LIFT NWD INTO THE MID ATLANTIC AND NERN STATES FRIDAY NIGHT. POORLY DEFINED WARM FRONT EXTENDS FROM SRN SC WWD THROUGH S CNTRL MS AND NERN LA WHERE IT INTERSECTS A COLD FRONT THAT STRETCHES SWD INTO THE GULF. LOW LEVEL DEWPOINTS IN THE MID 50 UPPER 60S WILL CONTINUE TO ADVECT NWD THROUGH PARTS OF AL...GA AND THE ERN CAROLINAS FRIDAY AS THE LOW LEVEL JET SHIFTS EWD. THIS SHOULD RESULT IN AT LEAST MARGINAL INSTABILITY WITH MLCAPE GENERALLY FROM 400 TO 800 J/KG WITHIN THE WARM SECTOR. STRONGER INSTABILITY MAY DEVELOP OVER PARTS OF SRN GA INTO NRN FL WHERE STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER TROUGH MAY OVERTAKE THE MOIST BOUNDARY LAYER. BAND OF PRE-FRONTAL STORMS WILL LIKELY PERSIST AND SPREAD EAST THROUGH THE SERN U.S. WITHIN ZONE OF UPPER DIVERGENCE AND DEEP LAYER ASCENT ACCOMPANYING THE EJECTING UPPER TROUGH. LOW LEVEL HODOGRAPHS AND DEEP LAYER SHEAR WILL REMAIN SUFFICIENT FOR ORGANIZED STORMS WITH SUPERCELLS AND LEWP STRUCTURES. PRIMARY THREATS WILL CONTINUE TO BE ISOLATED TORNADOES AND DAMAGING WIND WITH ANY SURFACE BASED STORMS. ..DIAL.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 12:27:52 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 07:27:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051231 SWODY1 SPC AC 051229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0629 AM CST FRI JAN 05 2007 VALID 051300Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE SOUTHEASTERN STATES... ...SYNOPSIS... VIGOROUS UPPER TROUGH CURRENTLY LOWER MS VALLEY EXPECTED TO BEGIN FILLING BY THIS AFTERNOON AS A LARGE SCALE TROUGH RAPIDLY APPROACHES FROM THE WRN U.S. THIS LOWER MS VALLEY TROUGH WILL MOVE TO THE ERN CAROLINAS BY 06Z AND OFFSHORE BY 12Z SAT SIGNIFICANTLY WEAKENED. THE SHARPNESS ON THE LOWER MS VALLEY TROUGH ON WATER VAPOR IMAGERY AND ONGOING IMPRESSIVE SQUALL LINE MOVING THRU AL SUGGEST THAT THE MODELS COULD BE A LITTLE QUICK ON THE WEAKENING PROCESS. AN UNSEASONABLY WARM AND MOIST AIR MASS CONTINUES TO SPREAD INLAND IN ADVANCE OF THE SQUALL LINE EWD THRU THE CAROLINAS. WHILE THE TROUGH WILL BE WEAKENING STEADILY FROM THIS AFTERNOON THRU THE REMAINDER OF THE PERIOD CONDITIONS ARE EXPECTED TO REMAIN FAVORABLE FOR SEVERE THUNDERSTORMS INTO TONIGHT GIVEN THE AMOUNT OF INSTABILITY AND SHEAR AVAILABLE. CURRENT N/S SQUALL LINE CENTRAL AL/WRN FL PANHANDLE WITH EMBEDDED SUPERCELLS AND ISOLATED TORNADOES SUPPORTED BY 60-70KT OF DEEP LAYER SHEAR/30-35KT OF SFC TO 1KM SHEAR AND HELICITIES FROM 250-300 M2/S2. SQUALL LINE EXPECTED TO ENTER WRN GA BY 14Z AND LIKELY REMAIN THE PRIMARY FOCUS FOR TODAYS SEVERE POTENTIAL. SFC HEATING ACROSS GA INTO SC AHEAD OF SQUALL LINE ALONG WITH DEWPOINTS IN THE 60S WILL ALLOW MLCAPES TO CLIMB TO 1000 J/KG OR GREATER. WIND DAMAGE WILL BE THE PRIMARY CONCERN WITH THE SQUALL LINE WITH SOME POTENTIAL FOR MORE ISOLATED SEVERE STORM DEVELOPMENT IN THE WARM SECTOR. A CONTINUED SMALL TORNADO THREAT WILL EXTEND EWD INTO SRN SC THIS EVENING AS SHEAR OF 40-50 KTS WILL MAINTAIN SUPERCELL POTENTIAL ALONG/AHEAD OF SQUALL LINE. HAVE MAINTAINED A MORE CONDITIONAL RISK AS FAR E AS ERN NC OVERNIGHT. WHILE TROUGH WILL CONTINUE TO WEAKEN PRESENCE OF 60 PLUS DEWPOINTS AND 35-40KT OF DEEP LAYER SHEAR WILL PROVIDE SUFFICIENT SUPPORT FOR CONTINUATION OF SQUALL LINE AND AT LEAST A WIND DAMAGE THREAT. GFS IN PARTICULAR INDICATES A STRONG CONVECTIVE SIGNAL EWD ACROSS NRN FL THIS AFTN/EVE. VERY MOIST AND MDTLY UNSTABLE AIRMASS WITH DEWPOINTS NEAR 70F THIS AREA COUPLED WITH SFC TEMPS NEAR 80F BY AFTERNOON RESULTS IN MLCAPES TO 1500 J/KG. COUPLED WITH MDT SHEAR...SEVERE POTENTIAL INCLUDING ISOLATED TORNADOES ARE EXPECTED NRN FL EVEN WITH THE ANTICIPATED WEAKENING OF THE UPPER TROUGH BY THIS EVENING. ..HALES.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 16:27:47 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 11:27:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051631 SWODY1 SPC AC 051629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST FRI JAN 05 2007 VALID 051630Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN STATES... ...SYNOPSIS... COMPACT...BUT INTENSE SHORTWAVE TROUGH WAS LOCATED OVER CENTRAL MS AT MID MORNING AND IS EXPECTED TO SLOWLY WEAKEN AS IT EJECTS NEWD INTO THE CAROLINAS TONIGHT...IN RESPONSE TO DEEPENING LONGWAVE TROUGH IN THE WEST. PREVIOUS MODEL RUNS HAVE WEAKENED SYSTEM TOO FAST AND THIS COULD BE THE CASE AGAIN GIVEN LATEST WATER VAPOR TRENDS AND RELATIVELY WEAKEN CONFLUENCE ALOFT AHEAD OF THE SYSTEM. ...SERN STATES... A SQUALL LINE WAS MOVING EWD AT 35-40 KT THROUGH WRN GA/SERN AL AND THE WRN FL PANHANDLE...AND SHOULD BEGIN TO ACCELERATE THIS AFTERNOON/EVENING AS THE UPPER TROUGH BEGINS TO LIFT NEWD MORE RAPIDLY. AN UNSEASONABLY WARM AND MOIST AIR MASS...MID 60 DEWPOINTS ...WAS SPREADING NWD IN ADVANCE OF THE SQUALL LINE INTO THE CAROLINAS. TEMPERATURES ARE EXPECTED TO WARM AT LEAST INTO THE LOWER TO MID 70S AND YIELD MLCAPE VALUES FROM 500 TO 1000 J/KG EAST OF THE SQUALL LINE. DEEP LAYER SHEAR AT 50-60 KT WILL BE SUPPORTIVE OF SUPERCELLS WITHIN AND AHEAD OF THE LINE. THE MOIST BOUNDARY LAYER COMBINED WITH 1 KM SHEAR OF 20 TO 30 KT WILL FAVOR THE DEVELOPMENT OF TORNADOES. ALSO...DRYING BETWEEN 925-800 MB...AND EVIDENT AT HIGH LEVELS ON WATER VAPOR IMAGERY...IS EXPECTED TO SUPPORT A WIND DAMAGE THREAT ALONG THE EWD MOVING SQUALL LINE. ALTHOUGH THE UPPER SYSTEM SHOULD WEAKEN SOME TONIGHT...THE STRENGTH OF THE SHEAR/INSTABILITY IS EXPECTED TO MAINTAIN A SUPERCELL POTENTIAL AN ACTIVE SQUALL LINE INTO THE ERN CAROLINAS. THE PRESENCE OF THE APPROACHING SHORTWAVE TROUGH...DEEP LAYER SHEAR AT 45-50 KT AND 1 KM SHEAR AT 20-30 KT INDICATES THE THREAT FOR WIND DAMAGE AND TORNADOES SHOULD CONTINUE INTO TONIGHT. ..IMY.. 01/05/2007  From swody1 at goshenarc.org Fri Jan 5 19:58:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 14:58:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 052001 SWODY1 SPC AC 051959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0159 PM CST FRI JAN 05 2007 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SERN STATES... ...SERN STATES... WATER VAPOR IMAGERY CONTINUES TO SHOW A VIGOROUS MID-LEVEL SHORTWAVE TROUGH EJECTING NEWD ACROSS MS/AL. STRONG ASCENT AHEAD OF THIS FEATURE WAS SUPPORTING A LINEAR MCS FROM UPSTATE SC SWD INTO THE NERN GULF OF MEXICO. THE LINE...AND DISCRETE CELLS AHEAD OF THE LINE...HAVE BEEN INCREASING SINCE 18Z. THIS UPSWING IN INTENSITY MAY BE INDICATIVE OF STRONGER HEIGHT FALLS BEGINNING TO SWING NEWD INTO THE FL PNHDL/SWRN GA AT MID-AFTN. IN FACT...18Z MESOANALYSIS PLACED A PRESSURE FALL AXIS FROM NRN FL INTO SERN GA AND SUGGESTED THAT THE ENVIRONMENT WAS BECOMING SUPPORTIVE FOR ANOTHER ROUND OF ORGANIZED TSTMS. INVERSION NOTED JUST BELOW 750 MB IN THE 18Z CHS SOUNDING WILL LIKELY BE ERODED AS THE STRONGER UVVS SPREAD NEWD. BOUNDARY LAYER HAS BECOME UNSTABLE AS TEMPERATURES/DEW POINTS HAVE RISEN INTO THE MID 70S/MID 60S RESPECTIVELY. AS THE MID-LEVELS COOL...THE COLUMN WILL SUPPORT VIGOROUS UPDRAFTS. AS A RESULT...THE LINE OF STORMS ACROSS ECNTRL GA TO THE NERN GULF OF MEXICO WILL LIKELY REMAIN STRONG AS IT SWEEPS ENEWD INTO PARTS OF NC/SC...SERN GA AND NRN FL THROUGH TONIGHT. THE UPPER SYSTEM HAS NOT WEAKENED AS SUGGESTED BY PREVIOUS MODELS. AS A RESULT...MID-LEVEL WINDS HAVE REMAINED QUITE STRONG AND DEEP LAYER SHEAR IN EXCESS OF 50 KTS WILL BE SLOW TO WEAKEN THIS EVENING. THIS WILL SUPPORT SUPERCELL STRUCTURES...BOTH AHEAD OF AND EMBEDDED WITHIN THE LINEAR MCS. SMALL SCALE BOWS WILL BE CAPABLE OF DAMAGING WIND GUSTS. ADDITIONALLY...ISOLD TORNADOES WILL BE POSSIBLE...ESPECIALLY OVER SERN GA AND PARTS OF SC WHERE THE LOW-LEVEL FLOW REMAINS SOMEWHAT BACKED VCNTY THE STRONGER PRESSURE FALLS. ..RACY.. 01/05/2007  From swody1 at goshenarc.org Sat Jan 6 00:58:46 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 05 Jan 2007 19:58:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060102 SWODY1 SPC AC 060100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 PM CST FRI JAN 05 2007 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NRN FL THROUGH THE ERN CAROLINAS AND SERN VA... ...NRN FL THROUGH SERN GA...THE ERN CAROLINAS AND SERN VA... THE SHORTWAVE TROUGH CENTERED OVER GA WILL CONTINUE NE THROUGH THE CAROLINAS TONIGHT AND OFFSHORE EARLY SATURDAY...DEAMPLIFYING IN THE PROCESS. LOW LEVEL JET SHOULD STRENGTHEN TO 50+ KT ACROSS THE ERN CAROLINAS INTO ERN VA WITHIN REGION OF HEIGHT FALLS DOWNSTREAM FROM THE SHORTWAVE TROUGH. LATEST OBJECTIVE ANALYSIS SHOW MLCAPE FROM 500 TO 1000 J/KG OVER THE ERN CAROLINAS. BAND OF PRE-FRONTAL STORMS FROM S CNTRL NC SWD THROUGH SERN GA AND NRN FL WILL PERSIST NEXT SEVERAL HOURS ALONG WARM CONVEYOR BELT AND WITHIN ZONE OF DPVA/ASCENT ACCOMPANYING THE SHORTWAVE TROUGH. THIS ACTIVITY WILL SHIFT ENEWD OVERNIGHT. STORMS OVER NRN FL MAY GRADUALLY DECREASE LATER THIS EVENING AS THE LOW LEVEL JET AND STRONGER FORCING FOR ASCENT LIFT AWAY FROM THIS REGION. HOWEVER...THE STRENGTHENING LOW LEVEL JET OVER THE CAROLINAS INTO SERN VA SHOULD ENHANCE STORM RELATIVE INFLOW AND MAINTAIN FAVORABLE HODOGRAPHS FOR LOW LEVEL MESOCYCLONES. THEREFORE...THREAT FOR ISOLATED DAMAGING WIND AND ISOLATED TORNADOES IN THIS REGION MAY PERSIST THE REMAINDER OF THIS EVENING INTO THE EARLY MORNING. PRIMARY LIMING FACTORS WILL BE TENDENCY ..DIAL.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 05:39:06 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 00:39:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060543 SWODY1 SPC AC 060540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...GULF COASTAL STATES... POSITIVELY TILTED UPPER TROUGH WILL CONTINUE EWD THROUGH THE SRN PLAINS AND LOWER MS VALLEY SATURDAY AND SATURDAY NIGHT. COLD FRONT CURRENTLY FROM THE GREAT LAKES SWWD THROUGH SWRN TX WILL MOVE EAST AND EXTEND FROM THE NERN STATES SWWD THROUGH THE NWRN GULF BY EARLY SATURDAY EVENING. WEAK SURFACE WAVE IS FORECAST TO DEVELOP ALONG FRONT OVER THE NWRN GULF BY SATURDAY NIGHT WITHIN UPPER JET ENTRANCE REGION AND ZONE OF HEIGHT FALLS ATTENDING THE SHORTWAVE TROUGH. AS THIS OCCURS THE LOW LEVEL JET WILL STRENGTHEN OVER THE GULF AND INTO THE SERN STATES. THUNDERSTORMS SHOULD DEVELOP WITHIN ZONE OF INCREASING THETA-E ADVECTION AND ISENTROPIC ASCENT IN VICINITY OF AND N OF FRONTAL BOUNDARY OVER THE GULF COASTAL AREA SATURDAY NIGHT. WEAK INSTABILITY AND POOR LAPSE RATES WILL LIMIT ANY SEVERE POTENTIAL. OTHER ELEVATED CONVECTION MAY DEVELOP WITHIN ZONE OF FRONTOGENETIC FORCING ON COOL SIDE OF SURFACE FRONT FROM ERN TX INTO THE LOWER MS VALLEY. HOWEVER...FORECAST SOUNDING WITH POOR MID LEVEL LAPSE RATES SHOW VERY LITTLE INSTABILITY IN LAYERS ABOVE -5C...SUGGESTING ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED WITH THIS ACTIVITY. ...SRN NEW ENGLAND... ISOLATED LIGHTING STRIKES MAY ACCOMPANY PRE-FRONTAL CONVECTION SATURDAY MORNING BEFORE MOVING OFFSHORE WITH FRONTAL PASSAGE BY AFTERNOON. ..DIAL.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 12:42:42 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 07:42:42 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061246 SWODY1 SPC AC 061244 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 AM CST SAT JAN 06 2007 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... STRONG WESTERLIES ACROSS MUCH OF CONUS CURRENTLY WILL GAIN AMPLITUDE AS STRONG PAC NW S/WV DEEPENS OVER THE PLAINS BY THE END OF THE FORECAST PERIOD. ALL CONVECTION NOW OFFSHORE MID ATLANTIC COAST AS WEAKENING SYSTEM CONTINUES EWD INTO WRN ATLANTIC. AN UNSEASONABLY WARM...MOIST AIR MASS CURRENTLY OVER NERN STATES AHEAD OF WEAK SURFACE SYSTEM/UPPER TROUGH MOVING THRU THE ERN GREAT LAKES. SOME WEAK CONVECTION/ISOLATED LIGHTNING STRIKES POSSIBLE AS 12Z SOUNDINGS FROM BUF TO CHH INDICATE SOME MEAGER CAPE. HOWEVER ANY CONVECTIVE THREAT SHOULD DIMINISH FROM W TO E THIS AFTERNOON. PRIMARY SURFACE FRONTAL ZONE EXTENDS WWD ACROSS NRN FL AND NRN GULF OF MEXICO. WITH TROUGH DEEPENING INTO PLAINS TONIGHT PRESSURE WILL FALL OVER THE LOWER MS VALLEY LEADING TO GRADUAL NWD MOVEMENT OF FRONTAL ZONE ONSHORE CENTRAL GULF COAST. LOW LEVEL JET WILL BACK AND INCREASE TONIGHT WITH A DEVELOPING ZONE OF THETA-E ADVECTION...ALONG AND N OF RETURNING FRONTAL BOUNDARY. LAPSE RATES ARE FORECAST TO BE WEAK...GENERALLY LESS THAN 6C/KM VICINITY AND N OF GULF FRONT WHICH WILL PRECLUDE DEVELOPMENT OF ANY APPRECIABLE INSTABILITY. OVERNIGHT THUNDERSTORMS WILL BECOME INCREASINGLY LIKELY WITHIN THE ZONE OF STRONGEST ASCENT N OF WARM FRONT...BUT SEVERE POTENTIAL IS NON-EXISTENT THRU 12Z SUNDAY. ..HALES.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 16:18:45 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 11:18:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061622 SWODY1 SPC AC 061620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST SAT JAN 06 2007 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... LONGWAVE TROUGH...LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY ...WILL AMPLIFY BY THE END OF THE PERIOD AS A STRONG SHORTWAVE TROUGH AND ASSOCIATED 90-100 KT MID LEVEL JET DIVES SEWD FROM THE PACIFIC NW INTO THE CENTRAL PLAINS. SURFACE FRONT EXTENDS FROM SRN TX EWD ACROSS THE FAR NRN GULF OF MEXICO AND INTO THE FL PANHANDLE. A WEAK INVERTED TROUGH WAS LOCATED ALONG THE FRONT ACROSS FAR SRN TX. THIS FEATURE IS FORECAST TO SLOWLY STRENGTHEN AND SHIFT NEWD ACROSS THE WRN GULF AND INTO THE LOWER MS VALLEY BY 12Z SUNDAY...AS THE UPPER TROUGH DEEPENS OVER THE CENTRAL U.S. ...LOWER MS VALLEY REGION... SATELLITE IMAGERY SHOWED SHALLOW CONVECTION WAS LOCATED NORTH OF THE FRONT NEAR THE GULF COAST IN RESPONSE TO WEAK WARM ADVECTION. AS THE LOW LEVEL JET STRENGTHENS LATER TODAY AND TONIGHT... INCREASING THETA-E ADVECTION NORTH OF THE BOUNDARY SHOULD RESULT IN WIDESPREAD RAIN AND A FEW THUNDERSTORMS TO DEVELOP. AS THE SURFACE LOW AND WARM FRONT MOVE INLAND...UPPER 60S DEWPOINTS ARE LIKELY TO SHIFT NWD INTO SRN LA. WIND PROFILES WILL BE RELATIVELY STRONG AND RESULT IN 40-50 KT OF DEEP LAYER SHEAR. HOWEVER...DESPITE THE RETURN OF A MOIST BOUNDARY LAYER...INSTABILITY WILL BE WEAK DUE TO WEAK LAPSE RATES ALOFT. ALSO...RELATIVELY WARM TEMPERATURES BETWEEN 450 AND 500 MB ARE EXPECTED TO LIMIT STRONG UPDRAFTS AND THE SEVERE POTENTIAL. ...ERN NY AND SRN NEW ENGLAND... LIGHTNING HAS REMAINED OFFSHORE THROUGH THE MORNING...DESPITE WEAK ELEVATED INSTABILITY INDICATED ON MORNING SOUNDINGS. CONVECTION WAS LOCATED ALONG COLD FRONT MOVING THROUGH CENTRAL NY...AND THIS SYSTEM WILL SWEEP RAPIDLY EWD THROUGH THE AFTERNOON. THE CONVECTION ALONG THE FRONT MAY BECOME DEEP ENOUGH FOR LIGHTNING AS SURFACE TEMPERATURES WARM INTO THE MID 60S AND HEIGHTS FALL ACROSS THE REGION...IN RESPONSE TO AN UPPER TROUGH MOVING EWD THROUGH ONTARIO/QUEBEC. ..IMY.. 01/06/2007  From swody1 at goshenarc.org Sat Jan 6 19:52:48 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 14:52:48 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061956 SWODY1 SPC AC 061954 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0154 PM CST SAT JAN 06 2007 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/NRN NEW ENGLAND THROUGH EARLY EVENING... CYCLONIC FLOW ALOFT CARRYING SEVERAL DISTURBANCES ALONG THE INTERNATIONAL BORDER HAS BEEN IMPETUS FOR FAST MOVING LOW-TOPPED CONVECTION ACROSS CNTRL/NRN NEW ENGLAND THIS AFTN. STRONGEST CELLS...INCLUDING SPORADIC LIGHTNING...WERE FOCUSED ALONG A COLD FRONT THAT WILL MOVE EWD THROUGH THE REMAINDER OF NEW ENGLAND THIS EVENING. THE MOST UNSTABLE ENVIRONMENT WILL REMAIN OVER PARTS OF CNTRL/SRN NH...SRN VT AND NRN MA WHERE A SEASONABLY MOIST/WARM BOUNDARY LAYER EXISTS. HERE...GUSTY WINDS WILL LIKELY ACCOMPANY THE STRONGER TSTMS GIVEN THE 50-55 KT WLY WINDS NOTED IN THE LOWEST 1KM /BURLINGTON /CCX/ VWP/. FARTHER E...THE BOUNDARY LAYER HAS NOT RECOVERED AS MUCH AND CONVECTION WILL LIKELY BECOME MORE ELEVATED WITH TIME...THOUGH STILL CAPABLE OF ISOLD LIGHTNING. ...GULF COASTAL REGION TONIGHT... WEAK WARM ADVECTION ALONG/N OF THE BAROCLINIC ZONE ALONG THE GULF COAST CONTINUES TO SUPPORT SHALLOW CONVECTION. SATL SHOWS EVIDENCE OF A SUB-SYNOPTIC CYCLONIC CIRCULATION MOVING OVER SRN TX WITH GENERAL NLY FLOW IN THE BOUNDARY LAYER OVER SE TX. AS THE UPSTREAM TROUGH CONTINUES TO DIG SEWD THROUGH THE CNTRL ROCKIES THIS EVE AND ONTO THE CNTRL PLAINS TONIGHT...THIS CIRCULATION MAY INTENSIFY AND DEVELOP NEWD TOWARD SRN LA. TO THE E OF THIS FEATURE...THE LLJ WILL BEGIN TO ACCELERATE...ENHANCING LOW- AND MID-LEVEL THETA-E ADVECTION ACROSS THE LWR MS VLY INTO THE ERN GULF COASTAL AREA. AS A RESULT...CONVECTION/TSTMS WILL BE ON THE INCREASE OVERNIGHT. THOUGH THE BOUNDARY LAYER WILL MOISTEN QUICKLY TONIGHT ALONG THE GULF COAST AND THERE WILL BE 40-50 KTS OF EFFECTIVE SHEAR...THE THERMAL BUOYANCY SHOULD REMAIN WEAK GIVEN THE WARM TEMPERATURES IN THE MID-LAYERS OF THE TROPOSPHERE. THE RESULT WILL BE WEAK UPDRAFTS AND LIMITED SEVERE POTENTIAL. ..RACY.. 01/06/2007  From swody1 at goshenarc.org Sun Jan 7 00:50:17 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 06 Jan 2007 19:50:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070054 SWODY1 SPC AC 070051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0651 PM CST SAT JAN 06 2007 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... LATEST WATER VAPOR IMAGERY SHOWS A DEVELOPING GREAT PLAINS UPPER-LEVEL TROUGH WITH SWLY FLOW IN PLACE ACROSS THE SRN AND ERN UNITED STATES. AS A GREAT PLAINS UPPER-LEVEL TROUGH DEEPENS TONIGHT...A 40-50 KT LOW-LEVEL JET WILL DEVELOP IN CNTRL MS. IN RESPONSE...A NEARLY STATIONARY FRONT LOCATED IN SRN MS AND CNTRL AL WILL LIFT NWD AS A WARM FRONT INCREASING LOW-LEVEL MOISTURE FROM SOUTH TO NORTH ACROSS THE REGION. THE STRONG ISENTROPIC ASCENT ASSOCIATED WITH THE LOW-LEVEL JET AND INCREASING LOW-LEVEL MOISTURE SHOULD HELP INITIATE SCATTERED THUNDERSTORMS LATE TONIGHT. DUE TO AN INVERSION NEAR THE SFC...THE ACTIVITY SHOULD REMAIN ELEVATED. ALTHOUGH SHEAR PROFILES WILL BE STRONG...FORECAST SOUNDINGS SHOW VERY LITTLE INSTABILITY WHICH SHOULD LIMIT THE SEVERE POTENTIAL. ELSEWHERE ACROSS THE CONUS THUNDERSTORM ACTIVITY IS NOT EXPECTED TONIGHT. ..BROYLES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 05:43:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 00:43:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070547 SWODY1 SPC AC 070545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1145 PM CST SAT JAN 06 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NC...SC AND SE VA... ...CAROLINAS AND SERN VIRGINIA... A SYNOPTIC-SCALE UPPER-LEVEL TROUGH WILL DEEPEN OVER THE CNTRL UNITED STATES TODAY AND MOVE EWD INTO THE MS VALLEY. IN RESPONSE...A SFC LOW IS FORECAST TO ORGANIZE OVER THE SERN U.S. AND MOVE NEWD INTO THE SRN APPALACHIAN MTNS THIS AFTERNOON. A STRONG LOW-LEVEL JET WILL INCREASE IN STRENGTH AND SIZE AS LOW-LEVEL MOISTURE IS BROUGHT NWD ACROSS THE CAROLINAS. THE INCREASING MOISTURE AND STRONG LARGE-SCALE ASCENT SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS IN THE CAROLINAS BY AFTERNOON. THE STORMS SHOULD MOVE QUICKLY NEWD ACROSS NC BY EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS AFTERNOON SHOW IMPRESSIVE SHEAR PROFILES WITH BACKED SELY SFC WINDS AND 50 KT OF FLOW AT 850 MB. THE LARGE HODOGRAPHS COMBINED WITH STRONG VERTICAL SHEAR SHOULD BE SUFFICIENT FOR LOW-TOPPED SUPERCELLS CAPABLE OF PRODUCING A TORNADO OR TWO. THE TORNADO THREAT SHOULD REMAIN ISOLATED DUE TO WEAK INSTABILITY AS STORMS DEVELOP NEWD ACROSS THE CAROLINAS LATE THIS AFTERNOON INTO THE EVENING. ALSO...AN ISOLATED WIND DAMAGE THREAT MAY OCCUR WITH THE BETTER ORGANIZED THUNDERSTORMS. THE SEVERE THREAT SHOULD EXPAND NEWD DURING THE EVENING POSSIBLY AFFECTING AREAS AS FAR NORTH AS SE VA. ..BROYLES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 12:33:06 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 07:33:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071236 SWODY1 SPC AC 071234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 AM CST SUN JAN 07 2007 VALID 071300Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF AL/NRN GA ENEWD TO MID ATLANTIC STATES... AS IS FREQUENTLY THE CASE IN COOL SEASON SEVERE THREAT PATTERNS IN THE SOUTHEAST...THE ONLY CAVEAT SEPARATING AN ACTIVE STORM DAY FROM A NO SEVERE DAY IS AIR MASS BUOYANCY/INSTABILITY. CURRENT SITUATION IS TYPICAL AS A VERY STRONG TROUGH AND ASSOCIATED JET STRUCTURE RAPIDLY SWINGS EWD ACROSS THE PLAINS TO THE TN/OH VALLEYS BY 12Z MON. IN THE WAKE OF THE PREVIOUS SYSTEM THE AIR MASS OVER THE GULF WAS UNDISTURBED AND OVERNIGHT THERE HAS BEEN A DRAMATIC NWD RETURN OF MOISTURE ALONG THE GULF COAST AS PRECIPITABLE WATER HAS RISEN TO ABOVE 1.5 INCHES. WHILE THERE HAS BEEN A STEADY INCREASE IN CONVECTIVE TYPE PRECIPITATION OVERNIGHT ACROSS THE GULF STATES IN THE STRENGTHENING ISENTROPIC/WARM ADVECTION REGIME...THE WEAK LAPSE RATES HAVE LIMITED THE BUOYANCY WITH LITTLE LIGHTNING NOTED THUS FAR. SURFACE LOW HAS DEVELOPED IN RESPONSE TO THE APPROACH OF THE STRONG UPPER TROUGH AND WILL GRADUALLY DEEPEN FROM ITS CURRENT LOCATION OVER WCENTRAL MS NEWD ACROSS MIDDLE TN TO WRN PA BY 12Z MON. LOW/MID LEVEL JET ACROSS DEVELOPING WARM SECTOR AL/GA WILL INCREASE TO 50-60KT AS 100PLUS KT 500 MB POLAR JET SHIFTS EWD INTO TN/OH VALLEYS BY THIS EVENING. SHEAR PROFILES WILL BE VERY SUPPORTIVE OF ROTATING STORMS WITH SFC-1KM SHEAR INCREASING TO 40KT OR GREATER THIS AFTERNOON AND TONIGHT. MID 60 F DEWPOINTS WILL SPREAD INLAND BY THIS AFTERNOON AS FAR N AS CENTRAL AL/NRN GA AND ERN CAROLINAS. EVEN THOUGH THE WEAK LAPSE RATES AND MINIMAL DAYTIME HEATING WILL GENERALLY LIMIT MLCAPES TO 500 J/KG...THE STRENGTH OF THE SYSTEM COUPLED WITH THE UNSEASONABLY MOIST AIRMASS REQUIRES AN EXPANSION OF THE PRIMARILY CONDITIONAL SEVERE RISK AREA WWD INTO AL. LOW TOPPED SUPERCELLS WILL BECOME AN INCREASING CONCERN BY EARLY/MID AFTERNOON CENTRAL AL/GA SPREADING NEWD INTO CAROLINAS TONIGHT IN THE DEVELOPING WARM SECTOR. ADDITIONALLY MORE SYNOPTICALLY FORCED LINE SEGMENTS WILL DEVELOP ALONG/AHEAD OF COLD FRONT NOW NOTED FROM THE SURFACE LOW SWWD TO SWRN LA. A TORNADO THREAT WILL BE ASSOCIATED WITH THE DISCRETE SUPERCELLS THAT CAN DEVELOP IN THE WARM SECTOR AND POSSIBLY EMBEDDED IN THE MORE LINER ACTIVITY VICINITY COLD FRONT. ADDITIONALLY WIND DAMAGE WILL EXIST WITH SAME ACTIVITY GIVEN THE INTENSITY OF THE WIND FIELDS ALOFT. THIS THREAT OF ISOLATED TORNADOES/WIND DAMAGE WILL CONTINUE NEWD OVERNIGHT THRU THE MID ATLANTIC STATES AS THE SYSTEM SURFACE AND ALOFT INTENSIFIES FURTHER. ..HALES.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 16:30:40 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 11:30:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071634 SWODY1 SPC AC 071632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SUN JAN 07 2007 VALID 071630Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS THE SRN GULF STATES...AND LATER THIS AFTERNOON AND TONIGHT ACROSS PARTS OF THE CAROLINAS.... ...SYNOPSIS... LATEST WATER VAPOR SATELLITE IMAGERY SHOWS MID/UPPER LEVEL SHORTWAVE TROUGH/ASSOCIATED VORTICITY MAX IS OVER SRN IL EXTENDING SSWWD INTO SERN TX. THIS FEATURE IS LOCATED JUST AHEAD OF MAIN TROUGH OVER THE ERN NRN PLAINS EXTENDING SSWWD THROUGH W TX. 15Z SURFACE ANALYSIS HAS LOW PRESSURE OVER NERN MS/SWRN TN WITH A COLD FRONT EXTENDING THROUGH S CENTRAL LA...AND A QUASISTATIONARY FRONT THAT REACHES SEWD INTO CENTRAL GA BEFORE CURVING ENEWD ACROSS SERN SC. IT SEEMS THAT THE FOCUS FOR SEVERE ACTIVITY TODAY AND TONIGHT WILL BE THE COLD FRONT AS IT MOVES EWD/NEWD AS THE LOW TRAVELS THROUGH MIDDLE TN THIS AFTERNOON INTO WRN UPSTATE NEW YORK TONIGHT. ...PARTS OF ERN MS INTO SWRN GA... LATEST VISIBLE SATELLITE IMAGERY SHOWS CONSIDERABLE CLOUD COVER ACROSS MUCH OF THE GULF STATES WITH A FEW BREAKS OVER SERN MS INTO SWRN GA. STRONG FORCING IS EXPECTED TO OCCUR AS THE COLD FRONT MOVES EWD THIS AFTERNOON JUST AHEAD OF SECOND STRONGER TROUGH MOVING OVER THE SRN HALF OF THE MS VALLEY REGION DURING THE LATTER HALF OF THE PERIOD. EXPECT THAT AN INCREASE IN INTENSITY WILL OCCUR WITH CURRENT BAND OF SHOWERS/THUNDERSTORMS THAT EXTENDS FROM NWRN LA SWWD INTO S CENTRAL LA AS THEY MOVE INTO AL EARLY THIS AFTERNOON. DEEP LAYER SHEAR WILL BECOME MORE ENHANCED IN ASSOCIATION WITH REAR ENTRANCE REGION OF STRONG 300 MB JET /130-160 KT/ COUPLED WITH SSWLY 30-50 KT LOW LEVEL JET. MAIN THREAT WILL BE DAMAGING WINDS WITH THIS ACTIVITY. ...PARTS OF THE CAROLINAS INTO SERN VA... MAIN CONCERN AT THIS TIME IS HOW THE QUASISTATIONARY BOUNDARY /MAINLY DUE TO COLD AIR DAMMING ON THE LEE SIDE OF THE APPALACHIANS/ WILL PLAY A ROLE LATER THIS AFTERNOON AND TONIGHT. ATTENTION NEEDS TO BE GIVEN TO STRONG LOW LEVEL JET OF 50-60 KT AHEAD OF THE MAIN TROUGH THAT WILL EXTEND FROM SWRN GA INTO CENTRAL NC BY 08/00Z. MODELS INDICATE STRONG LOW LEVEL WARM ADVECTION AND ENHANCED UVVS ACROSS THE CAROLINAS...AND FEEL THAT IF THERE IS ANY SUPERCELL THREAT IT WILL BE WITH THE BOUNDARY AS IT BECOMES A WARM FRONT AND MOVES NWD INTO CENTRAL/NRN NC THIS EVENING. ONCE AGAIN... INSTABILITY WILL REMAIN VERY LIMITED WITH MUCAPE STRUGGLING TO BE AROUND 500 J/KG...BUT VERTICAL SHEAR PROFILES/STORM RELATIVE HELICITY VALUES ARE FORECAST TO BE 300-500 M2/S2 JUST SOUTH OF THE BOUNDARY AND HIGHER JUST NORTH OF IT. THUS...EXPECT COMPARATIVELY DISCRETE LOW-TOPPED SUPERCELLS TO DEVELOP AHEAD OF THE MAIN FRONTAL BOUNDARY THIS EVENING AND TONIGHT ACROSS PARTS OF THE CAROLINAS WITH THE MAIN THREAT BEING ISOLATED TORNADOES THIS EVENING...WITH MORE WIDESPREAD DAMAGING WINDS ASSOCIATED WITH THE COLD FRONT LATER TONIGHT AND TOWARDS THE END OF THE PERIOD. ..MCCARTHY.. 01/07/2007  From swody1 at goshenarc.org Sun Jan 7 19:32:25 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 14:32:25 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071936 SWODY1 SPC AC 071934 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0134 PM CST SUN JAN 07 2007 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE DEEP SOUTH INTO THE SERN STATES/SERN MID-ATLANTIC REGIONS... ...SERN STATES... A WEAK LEAD SHORTWAVE TROUGH CONTINUES TO SHEAR ENEWD ACROSS THE TN VLY THIS AFTN AND IS LIKELY CONTRIBUTING TO THE RECENT INCREASE IN CONVECTION/TSTMS FROM ERN TN SWWD INTO WCNTRL AL. A MORE ROBUST IMPULSE WAS QUICKLY MOVING SEWD THROUGH THE CNTRL/SRN PLAINS AND WILL BECOME NEGATIVELY TILTED AS IT BEGINS TO EJECT EWD ACROSS THE OH/TN VLYS LATER TONIGHT. 18Z SFC ANALYSIS SHOWS A 1010 MB LOW OVER SCNTRL KY WITH A WARM FRONT REDEVELOPING NWD ALONG THE SRN EDGE OF THE APPALACHIANS. A VERY WARM AND MOIST BOUNDARY LAYER WAS FLOODING NWD AHEAD OF A COLD FRONT SITUATED FROM THE LOW SWD ACROSS NWRN AL TO WEST OF THE NEW ORLEANS AREA. 18Z BMX SOUNDING EXHIBITED AROUND 185 J/KG MLCAPES WITH RATHER POOR LAPSE RATES. THIS WAS RESULTING IN AN ENVIRONMENT SUPPORTIVE OF A GRADUAL DEEPENING/STRENGTHENING OF MOIST CONVECTION AMIDST WEAK LARGE SCALE FORCING. AS THE UPSTREAM PLAINS TROUGH SWINGS EWD TONIGHT AND MID-UPPER LEVEL JET MAX ACCELERATES...FORCING FOR ASCENT WILL INCREASE THROUGH A DEEPER LAYER AND CONVECTION SHOULD FURTHER STRENGTHEN ALONG/AHEAD OF THE SEWD MOVING COLD FRONT OVERNIGHT. THE COINCIDENT INCREASE IN LOW-LEVEL FLOW WILL RESULT IN AN EROSION OF THE WEDGE FRONT AND RAPID MOISTENING OF THE COLUMN DOWNSTREAM ACROSS THE SRN APPALACHIANS AND THE CAROLINAS...SERN VA BY 12Z. GIVEN THAT THE PRIMARY SFC LOW SHOULD REMAIN WEST OF THE APPALACHIAN SPINE...STRONGEST VEERING WITH HEIGHT OF THE WIND FIELD SHOULD EXIST ALONG THE WARM FRONT AS IT LIFTS NWD WITH TIME THIS EVENING/OVERNIGHT. HOWEVER...STRONG SPEED SHEAR SHOULD CONTINUE OWING TO THE INCREASING LOW- AND MID-LEVEL WIND FIELDS OVERNIGHT ACROSS THE WARM SECTOR. AS A RESULT OF THE DESTABILIZATION... INCREASED FORCING AND THE FAVORABLE VERTICAL SHEAR...ANY SUSTAINED TSTM COULD BECOME SUPERCELLULAR...EITHER EMBEDDED WITHIN THE LINEAR MCS OR AHEAD OF IT. MAIN THREAT WILL BE DAMAGING WINDS...ALTHOUGH BRIEF TORNADOES COULD ALSO OCCUR. MAIN SEVERE WEATHER THREATS WILL OCCUR ACROSS PORTIONS OF THE DEEP S INTO WRN GA THIS EVENING...SHIFTING EWD WITH TIME INTO PARTS OF THE CAROLINAS AND SERN VA BY 12Z MONDAY. ..RACY.. 01/07/2007  From swody1 at goshenarc.org Mon Jan 8 00:44:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 07 Jan 2007 19:44:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080047 SWODY1 SPC AC 080045 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 PM CST SUN JAN 07 2007 VALID 080100Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SE AL...GA...SC AND NC... ...SE AL/GA/SC/SRN AND ERN NC... WATER VAPOR IMAGERY CURRENTLY SHOWS A SYNOPTIC SCALE UPPER-LEVEL TROUGH LOCATED ACROSS THE PLAINS AND MID MS VALLEY. AHEAD OF THE TROUGH...A BAND OF MID-LEVEL MOISTURE EXTENDS FROM THE WRN GULF OF MEXICO NEWD ACROSS THE SERN UNITED STATES. THIS MOISTURE IS CO-LOCATED WITH THE STRONGER LARGE-SCALE ASCENT ASSOCIATED WITH THE TROUGH AND IS SUPPORTING A WELL-DEVELOPED CONVECTIVE LINE FROM THE WRN FL PANHANDLE NEWD INTO NRN GA. THE LINE IS LOCATED AHEAD OF A COLD FRONT WITH MID 60 F SFC DEWPOINTS PRESENT ACROSS MOST OF GA...SC AND SRN NC. THIS SHOULD SUSTAIN THE LINE OF THUNDERSTORMS WITH THE STRONGER CONVECTION MOVING ENEWD ACROSS SC INTO SERN NC OVERNIGHT. LATEST OBJECTIVE ANALYSIS SHOWS A 100 KT MID-LEVEL JET EXTENDING NEWD FROM THE LOWER MS VALLEY NEWD INTO THE OH VALLEY. THE MID-LEVEL JET IS BROAD AND 50 KT OF FLOW EXISTS ACROSS MOST OF GA...SC AND NC ATTM. ALTHOUGH INSTABILITY WILL REMAIN WEAK ACROSS THE REGION TONIGHT...THE STRONG VERTICAL SHEAR SHOULD CONTINUE TO SUPPORT AN ISOLATED SEVERE THREAT WITH THE LINE. WIND DAMAGE WOULD BE THE PRIMARY THREAT ALTHOUGH A TORNADO CAN NOT BE RULED OUT. AS THE LINE APPROACHES HIGHER SFC DEWPOINTS ACROSS ERN SC AND ERN NC...REDEVELOPMENT OR ENHANCEMENT OF THE LINE MAY OCCUR LATE TONIGHT. ..BROYLES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 05:33:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 00:33:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080536 SWODY1 SPC AC 080534 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 PM CST SUN JAN 07 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...ERN SEABOARD... A LARGE-SCALE TROUGH WILL DOMINATE THE ERN U.S. AS A COLD FRONT MOVES EWD ACROSS THE ERN SEABOARD. A LINE OF CONVECTION SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD WITH THUNDERSTORMS EMBEDDED IN THE LINE. MODEL FORECASTS DESTABILIZE THE AIRMASS ALONG THE IMMEDIATE COAST OF NC THIS MORNING WHICH MAY BE ENOUGH FOR A MARGINAL SEVERE THREAT ACROSS ERN NC AND ERN VA. ALTHOUGH STRONG GUSTY WINDS WILL BE POSSIBLE DUE TO THE VERY STRONG SHEAR PROFILES...THE SEVERE THREAT SHOULD SHIFT EWD OFF THE ATLANTIC COAST BY MIDDAY AS THE FRONT MOVES OFFSHORE. ..BROYLES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 12:31:03 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 07:31:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081234 SWODY1 SPC AC 081232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST MON JAN 08 2007 VALID 081300Z - 091200Z ...NO SVR TSTM AREAS FORECAST... PROGRESSIVE LARGE SCALE TROUGH ERN U.S. WITH BROAD RIDGE OVER THE W. VIGOROUS S/WV TROUGH WITH ASSOCIATED STRONG WIND FIELDS CURRENTLY CROSSING APPALACHIANS WITH DEEPENING SURFACE LOW HEADING NEWD ACROSS SERN CANADA. COLD FRONT FROM SURFACE LOW SWWD E OF APPALACHIANS TO NRN FL WILL PUSH OFFSHORE BY MID DAY. THE VERY MOIST SWLY FLOW PRECEEDING FRONT CONTAINS VERY LITTLE INSTABILITY GIVEN LAPSE RATES LESS THAN 6 C/KM. BAND OF LOW TOPPED CONVECTION PRECEEDING FRONT WILL MOVE OFFSHORE BY MID MORNING ESSENTIALLY ENDING ANY SEVERE THREAT. GIVEN THE STRONG DEEP LAYER SHEAR THERE IS STILL A CHANCE OF A BRIEF SEVERE WIND GUST...ISOLATED TORNADO UNTIL THIS ACTIVITY MOVES OFFSHORE. REF MCD 0038. EXAMINING 12Z FLORIDA SOUNDINGS...LAPSE RATES AGAIN ARE WEAK AND THERE IS LITTLE SUPPORT FOR MORE THAN ISOLATED LIGHTNING STRIKES AS FRONTAL BAND MOVES SEWD ACROSS PENINSULA TODAY. ..HALES.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 16:23:10 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 11:23:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081626 SWODY1 SPC AC 081624 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1024 AM CST MON JAN 08 2007 VALID 081630Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE MID/UPPER LEVEL TROUGH IS OVER THE ERN HALF OF THE U.S. THIS MORNING WITH A FLATTENING RIDGE OVER THE WRN U.S. LAST IN A SERIES OF EMBEDDED SHORTWAVES/VORTICITY MAXS WILL BE MOVING SEWD FROM THE NRN PLAINS INTO THE LOWER OHIO VALLEY DURING THE PERIOD WHICH WILL ESCORT THE ERN U.S. TROUGH INTO THE NERN/MID ATLANTIC REGIONS BY 09/12Z. LATEST SURFACE ANALYSIS SHOWS COLD FRONT EXTENDING SWD THROUGH ERN NEW YORK STATE AND ERN NC THEN SWWD ACROSS NRN FL. FRONT SHOULD BE WELL OFFSHORE BY 09/00Z WITH THE EXCEPTION OF THE SRN HALF OF FL WHERE THE FRONT WILL MOVE SWD THROUGH THE REMAINDER OF THE PENINSULA LATER TONIGHT. ...ERN CAROLINAS AND SRN NEW ENGLAND... LATEST LIGHTNING DATA SHOWS REMAINDER OF ACTIVITY IS SOUTH OF LONG ISLAND AND WELL OFFSHORE ALREADY. THUS...LOOKS LIKE ANY THUNDER PROBABILITIES WILL REMAIN THRU 18Z AND THEN DECREASE RAPIDLY AFTERWARDS AS THE FRONT MOVES EWD ACROSS NEW ENGLAND SWD ACROSS THE OUTER BANKS. CONVECTIVE POTENTIAL ACROSS FL HAS ALSO DECREASED RAPIDLY AS DYNAMIC FORCING HAS ALREADY SWUNG NEWD INTO NEW ENGLAND WITH SOUTH CENTRAL ATLANTIC RIDGE KEEPING GEOPOTENTIAL HEIGHTS AT/NEAR 5880 M AT THIS TIME. THUS...LACK OF SUFFICIENT LOW LEVEL FLOW/INSTABILITY SHOULD INHIBIT SEVERE THUNDERSTORM DEVELOPMENT THROUGH THE PERIOD...AND THUNDERSTORM ACTIVITY IS EXPECTED TO LESSEN GOING INTO THIS AFTERNOON AND EVENING ACROSS THE MID ATLANTIC REGION. ..MCCARTHY.. 01/08/2007  From swody1 at goshenarc.org Mon Jan 8 19:17:55 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 14:17:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081921 SWODY1 SPC AC 081919 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0119 PM CST MON JAN 08 2007 VALID 082000Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SRN FL PENINSULA... LATEST VIS SATELLITE/RADAR IMAGERY INDICATE SHOWERS ARE DEEPENING ACROSS THE SERN FL PENINSULA...ALONG SHARPENING LOW LEVEL CONFLUENCE ZONE...LIKELY ENHANCED BY DIABATIC HEATING. IT APPEARS CONVERGENCE WILL BE ADEQUATE FOR CONTINUED UPDRAFT DEVELOPMENT DESPITE THE VERY WEAK MID LEVEL LAPSE RATE ENVIRONMENT. CONTINUED BOUNDARY LAYER HEATING WILL ALSO ENHANCE THE PROSPECT FOR ISOLATED THUNDERSTORMS ALONG ADVANCING WIND SHIFT...WITH MORE DEVELOPMENT LIKELY OFF THE EAST COAST LATER THIS AFTERNOON/EVENING. ..DARROW.. 01/08/2007  From swody1 at goshenarc.org Tue Jan 9 00:51:11 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 08 Jan 2007 19:51:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090054 SWODY1 SPC AC 090052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST MON JAN 08 2007 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... A LARGE UPPER-LEVEL TROUGH OVER THE OH AND TN VALLEYS WILL MOVE EWD TONIGHT AS A COLD FRONT MOVES SEWD ACROSS THE FL PENINSULA. LARGE-SCALE ASCENT AND LOW-LEVEL MOISTURE APPEAR SUFFICIENT FOR ISOLATED THUNDERSTORM DEVELOPMENT AROUND MIAMI FL THIS EVENING. HOWEVER...THE ACTIVITY SHOULD NOT REACH SEVERE LIMITS. ELSEWHERE...THUNDERSTORMS ARE NOT EXPECTED ACROSS THE CONUS. ..BROYLES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 05:24:43 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 00:24:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090528 SWODY1 SPC AC 090527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST MON JAN 08 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... AN UPPER-LEVEL TROUGH OVER THE ERN UNITED STATES WILL MOVE EWD TODAY AS A COLD FRONT MOVES QUICKLY INTO THE ATLANTIC COASTAL AREAS BY MIDDAY. THUNDERSTORM DEVELOPMENT WILL BE LIKELY AS THE BOUNDARY MOVES OFFSHORE DURING THE EVENING. ELSEWHERE...AN UPPER-LEVEL DISTURBANCE WILL MOVE INTO THE PACIFIC NORTHWEST TUESDAY NIGHT. A FEW THUNDERSTORMS WILL BE POSSIBLE ALONG THE WA COAST. HOWEVER...NO SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE CONUS TUESDAY OR TUESDAY NIGHT. ..BROYLES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 12:31:02 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 07:31:02 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091234 SWODY1 SPC AC 091232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST TUE JAN 09 2007 VALID 091300Z - 101200Z ...NO SVR TSTM AREAS FORECAST... THE ONLY AREA THAT WILL HAVE ANY THREAT OF ISOLATED LIGHTNING THIS FORECAST PERIOD IS ALONG AND OFFSHORE THE WA COAST. VERY COLD TROUGH DIGS SEWD OUT OF THE GULF OF ALASKA AND BY THE END OF THE FORECAST PERIOD AN ONSHORE FLOW OF COLD UNSTABLE AIR WILL BE AFFECTING WRN WA. LIGHTNING EXPECTED TO REMAIN PRIMARILY OFFSHORE WHERE STEEP LAPSE RATES TO NEAR 500MB COUPLED WITH THE OVER WATER TRAJECTORY WILL SUPPORT CONVECTION. SUPPORT FOR ANY LIGHTNING WILL DIMINISH INLAND AWAY FROM THE COMPARATIVELY WARM WATER SOURCE. ..HALES.. 01/09/2007  From swody1 at goshenarc.org Tue Jan 9 16:24:10 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 09 Jan 2007 11:24:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 091627 SWODY1 SPC AC 091625 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1025 AM CST TUE JAN 09 2007 VALID 091630Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... CYCLONIC CIRCULATION EXPECTED TO AMPLIFY OFF THE BC CST DURING THE NEXT 24 HRS AS ASSOCIATED SFC LOW REDEVELOPS E OF THE CANADIAN RCKYS. ONSHORE UPSLOPE FLOW WILL STRENGTHEN AND DEEPEN OVER WRN WA AND ORE TONIGHT/EARLY WEDNESDAY AS COLD FRONT SWEEPS E OF THE CASCADES. THIS PATTERN LIKELY WILL RESULT IN FAIRLY WIDESPREAD POST-FRONTAL CONVECTION...ESPECIALLY IN WRN WA. WITH 500 MB TEMPERATURES FALLING TO AOB MINUS 30C AND RELATIVELY MILD AIR PERSISTING NEAR THE SURFACE...POTENTIAL WILL EXIST FOR CHARGE SEPARATION/LIGHTING. SUPPORT FOR ANY LIGHTNING SHOULD DIMINISH INLAND AWAY FROM THE COMPARATIVELY WARM WATER. IN THE EAST...AN ISOLATED STRIKE OR TWO COULD OCCUR WITH UNIDIRECTIONAL WLY FLOW IN THE LEE OF LK ONTARIO TODAY...AND ON THE UPSLOPE SIDE OF THE CNTRL APLCNS...AHEAD OF SHORTWAVE IMPULSE IN BROAD CYCLONIC JET. ..CORFIDI.. 01/09/2007  From swody1 at goshenarc.org Fri Jan 12 06:18:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 01:18:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120550 SWODY1 SPC AC 120548 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST THU JAN 11 2007 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SIGNIFICANT MID-UPPER LEVEL PATTERN SHIFT UNDERWAY AS HEIGHTS FALL ACROSS WRN CONUS. POSITIVELY TILTED TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM SASK TO N-CENTRAL CA -- IS EXPECTED TO STRENGTHEN IN SRN PORTION WITH CLOSED LOW EVOLVING OVER NV EARLY IN PERIOD. ASSORTED MESOSCALE VORTICITY LOBES WILL PIVOT AROUND ASSOCIATED CIRCULATION...AS NET CYCLONE TRACK SLOWLY CURVES EWD OVER UT BY END OF PERIOD. AT SFC...INTENSE ARCTIC COLD FRONT NOW ANALYZED FROM ERN IA ACROSS SERN KS TO CENTRAL TX PANHANDLE -- IS FCST TO MOVE SWD TO POSITION OVER OH VALLEY..ARKLATEX...W-CENTRAL TX BY END OF PERIOD. KINEMATIC RESPONSES ASSOCIATED WITH LOW LEVEL CYCLOGENESIS OVER NWRN NM/SWRN CO SHOULD IMPEDE SWWD PROGRESS OF FRONT ACROSS ERN NM...AND IN FACT MAY CAUSE SOME NWD RETREAT THERE. ...SRN PLAINS...BIG BEND/PECOS VALLEY TO OZARKS... MRGL SVR POTENTIAL MAY DEVELOP DURING AFTERNOON ACROSS PORTIONS CENTRAL/NRN TX AHEAD OF FRONT...WHERE 50-60 KT MIDLEVEL SWLYS AND SELY SFC WINDS WILL CONTRIBUTE TO FAVORABLY LARGE DEEP-LAYER SHEAR VECTORS AND LOW LEVEL HODOGRAPHS. MAIN CAVEATS WILL BE WEAKNESS OF BOTH BUOYANCY AND LOW LEVEL FORCING FOR CONVECTION...IN ABSENCE OF ANY SIGNIFICANT PREFRONTAL BOUNDARIES. ALTHOUGH SHADED BY MID/UPPER CLOUDS FOR MUCH OF DAY...SUFFICIENT SFC HEATING MAY DEVELOP TO SUPPORT HORIZONTAL CONVECTIVE ROLLS...WITH SOME DEEPER DEVELOPMENT POSSIBLE DURING AFTERNOON WHEN SBCINH IS SMALLEST. WEAK LAPSE RATES ALOFT SHOULD LIMIT MLCAPES TO BELOW 500 J/KG IN MOST AREAS...AND ONLY SMALL PROPORTION OF CONVECTION MAY REACH OPTIMAL ICING LAYERS FOR CG LIGHTNING PRODUCTION. HOWEVER...GIVEN ENVIRONMENTAL SHEAR PROFILES...STORM ROTATION IS POSSIBLE WITH NONZERO RISK OF A TORNADO OR DAMAGING GUST. THIS THREAT SHOULD SHIFT GRADUALLY TOWARD HAIL AND ISOLATED WIND WITH WWD EXTENT -- ESPECIALLY INTO TRANS-PECOS...PERMIAN BASIN AND BIG BEND REGION WHERE SOMEWHAT HIGHER LCL...STEEPER DEEP-LAYER LAPSE RATES...AND LARGER BUOYANCY ARE EXPECTED. AFTERNOON/EARLY EVENING SHEAR PROFILES ALONG AND S OF FRONT SHOULD BE FAVORABLE FOR SUPERCELLS...WITH 40-50 KT EFFECTIVE SHEAR EVIDENT IN NAM/NAM-KF FCST SOUNDINGS...AND MLCAPE TO NEAR 700 J/KG. CONVECTIVE COVERAGE MAY BE LIMITED BY WEAK LOW LEVEL FORCING IN THIS REGION AS WELL. SVR POTENTIAL IN ALL AREAS APPEARS TO BE TOO MRGL/CONDITIONAL TO WARRANT CATEGORICAL OUTLOOK ATTM. ALTHOUGH LAPSE RATES ALOFT WILL BE WEAK...ISOLATED/EPISODIC GEN THUNDER POTENTIAL MAY EXIST AS FAR NE AS SWRN MO/WRN KY AND AS FAR N AS ATOP FREEZING SFC TEMPS IN PORTIONS OK/KS OVERNIGHT...SUPPORTED BY LOW LEVEL WAA REGIME...ASSOCIATED MOISTENING INVOF LLJ...AND ISENTROPIC ASCENT TO LFC. ..EDWARDS.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 12:39:29 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 07:39:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121242 SWODY1 SPC AC 121240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST FRI JAN 12 2007 VALID 121300Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS... ARCTIC COLD FRONT CONTINUES TO SURGE SWD INTO THE SRN PLAINS THIS MORNING WITH A POSITION EXTENDING FROM THE MID MS RIVER VALLEY SWWD INTO CENTRAL OK AND WEST TX AT 11Z. CONSIDERABLE COLD/DENSE SURFACE AIR BEHIND THE FRONT WILL MAINTAIN A RATHER STEADY SSEWD MOTION THROUGH THE PERIOD...DESPITE THE SWLY MID/UPPER LEVEL FLOW PREVAILING ACROSS THE WARM SECTOR. THE FRONT WILL LIKELY EXTEND FROM CENTRAL/SERN NM ENEWD INTO CENTRAL/NERN TX AND SERN MO BY THE EARLY EVENING. A SSWLY LLJ WILL BE SUSTAINED ACROSS MUCH OF TX POINTING INTO THE MID MS RIVER VALLEY THROUGH THE PERIOD AHEAD OF SLOW MOVING UPPER LOW DIGGING SSEWD ACROSS THE GREAT BASIN AND THE SWRN DESERTS. RESULTANT ISENTROPIC LIFTING WILL MAINTAIN A PERSISTENT AREA OF ELEVATED MOIST CONVECTION FROM PORTIONS OF WRN/CENTRAL TX ACROSS THE OZARK PLATEAU FOR MUCH OF THE PERIOD. WEAK ELEVATED INSTABILITY MAY SUPPORT ISOLATED THUNDERSTORMS WITHIN THIS BROAD AREA OF CONVECTION...LOCALLY ENHANCING RAINFALL AND FREEZING PRECIPITATION NORTH OF THE COLD FRONT. ACROSS THE WARM SECTOR...EXTENSIVE CLOUDS AND WEAK LOW LEVEL CONVERGENCE WILL BE INHIBITING FACTORS FOR NEAR-SURFACE BASED CONVECTION TODAY. HOWEVER...INCREASE FETCH OF MODIFIED GULF MOISTURE /I.E. SURFACE DEW POINTS IN THE MID 60SF/ AND TEMPERED AFTERNOON HEATING MAY STILL SUPPORT AREAS OF MARGINAL SURFACE BASED INSTABILITY AND MINIMAL SURFACE BASED CIN DURING THE AFTERNOON. IN ADDITION...MUCH OF THE REGION WILL REMAIN WITHIN MODEST DEEP LAYER SHEAR UNDER 40-50 KT SWLY MID LEVEL WINDS. THUS...A FEW STORMS MAY BECOME STRONG TO MARGINALLY SEVERE LATER TODAY AND EARLY THIS EVENING AHEAD OF THE SHALLOW COLD FRONT MAINLY ACROSS PORTIONS OF SWRN/CENTRAL TX. ..EVANS.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 16:30:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 11:30:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121633 SWODY1 SPC AC 121631 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1031 AM CST FRI JAN 12 2007 VALID 121630Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE DEVELOPING CLOSED LOW OVER NV/CA WILL MOVE SLOWLY EWD OVER THE SRN GREAT BASIN THROUGH EARLY SATURDAY...WITH A BROAD SWATH OF SW FLOW ALOFT DOWNSTREAM OVER THE CENTRAL AND ERN CONUS. IN THE LOW-LEVELS...A SHARP ARCTIC FRONT IS MOVING SLOWLY SEWD ACROSS THE SRN PLAINS AND MID MS VALLEY. PRONOUNCED WAA ABOVE THE FRONTAL SURFACE IS SUPPORTING AN INCREASING AREA OF PRECIPITATION NEAR AND N OF THE FRONT FROM NW TX INTO CENTRAL OK...AND THIS PRECIPITATION SHOULD INCREASE IN COVERAGE WHILE SPREADING NEWD TO THE OH VALLEY LATER TODAY THROUGH TONIGHT. MUCH OF THE PRECIPITATION WILL BE FREEZING RAIN A COUPLE OF COUNTIES N OF THE SURFACE FRONT...WHERE WEAK MID LEVEL INSTABILITY COULD SUPPORT A FEW EMBEDDED ELEVATED THUNDERSTORMS. FARTHER S...BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S WILL BE MAINTAINED ALONG THE FRONT FROM NE INTO CENTRAL TX...WHILE DEWPOINTS SHOULD REACH THE UPPER 60S ACROSS THE LOWER TX COAST. REGIONAL 12Z SOUNDINGS SHOW THE POTENTIAL FOR WEAK SURFACE-BASED INSTABILITY NEAR THE FRONT...ALONG WITH DEEP LAYER VERTICAL SHEAR THAT WILL BE SUFFICIENT FOR ORGANIZED SEVERE STORMS. HOWEVER...THE FLOW REGIME IS LARGELY ANAFRONTAL WHERE CONVECTION THAT FORMS ALONG THE FRONT WILL MOVE OVER THE SHALLOW COLD AIR MASS...LIMITING ANY WIND DAMAGE/TORNADO THREAT. SOMEWHAT STEEPER MID LEVEL LAPSE RATES OVER W TX COULD ALLOW FOR SOME SMALL HAIL WITH THE STRONGER CONVECTION...THOUGH STORM COVERAGE IS IN QUESTION THIS FAR SW. ..THOMPSON.. 01/12/2007  From swody1 at goshenarc.org Fri Jan 12 19:39:36 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 14:39:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121942 SWODY1 SPC AC 121940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST FRI JAN 12 2007 VALID 122000Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL CONTINUE MOVING ACROSS THE WRN U.S. THROUGH THE END OF THE PERIOD...WITH ASSOCIATED CLOSED LOW CROSSING THE GREAT BASIN. LOW-LEVEL SLY FLOW DOWNSTREAM OF THIS FEATURE RIDING ATOP SHALLOW/SWD-MOVING COLD FRONT WILL CONTINUE TO SUPPORT WIDESPREAD PRECIPITATION AND EMBEDDED THUNDERSTORMS ACROSS THE S CENTRAL U.S. THROUGH 13/12Z. ...FAR SERN NM ACROSS PARTS OF CENTRAL AND NRN TX... WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS WILL CONTINUE ACROSS THE SRN PLAINS THROUGH THE END OF THE PERIOD...AS COLD FRONT CONTINUES MOVING SWD AND SWLY FLOW ALOFT PERSISTS AHEAD OF WRN TROUGH. THOUGH DEWPOINTS IN THE 60S HAVE ADVECTED NWD INTO CENTRAL AND NERN TX AHEAD OF FRONT...WEAK LAPSE RATES AND WARM NOSE IN THE 850 TO 700 MB LAYER ARE RESULTING IN MINIMALLY-UNSTABLE/CAPPED AIRMASS. THOUGH SHEAR WILL REMAIN SUPPORTIVE FOR ORGANIZED STORMS...LACK OF INSTABILITY AND GENERALLY UNFAVORABLE THERMODYNAMICS PRECLUDE APPRECIABLE SEVERE THREAT -- PARTICULARLY GIVEN NNELY MEAN WIND AND ASSOCIATED TENDENCY FOR ANY SURFACE-BASED STORMS WHICH COULD DEVELOP NEAR FRONT TO MOVE NWD ACROSS THE BOUNDARY AND BECOME ELEVATED. A LIMITED THREAT FOR MARGINALLY-SEVERE HAIL MAY DEVELOP OVERNIGHT ACROSS FAR SERN NM AND INTO FAR W TX AND THE TRANSPECOS REGION AS STEEPER LAPSE RATES APPROACH FROM THE W. ELSEWHERE...WILL MAINTAIN VERY LOW PROBABILITY THREAT FOR A WEAK/BRIEF TORNADO OR LOCAL WIND GUST NEAR THE FRONT FROM THE HILL COUNTRY REGION NEWD INTO NERN TX THROUGH THE END OF THE PERIOD. ..GOSS.. 01/12/2007  From swody1 at goshenarc.org Sat Jan 13 00:33:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 12 Jan 2007 19:33:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130036 SWODY1 SPC AC 130034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST FRI JAN 12 2007 VALID 130100Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SWLY FLOW ALOFT WILL BE MAINTAINED OVER MUCH OF CENTRAL CONUS...DOWNSTREAM FROM STRONG MID-UPPER LEVEL CYCLONE NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN NV. THIS LOW IS FCST TO MOVE SLOWLY EWD OVER SWRN UT THROUGH REMAINDER PERIOD...WITH ASSOCIATED SFC LOW OVER CENTRAL/SWRN CO. STRONG ARCTIC COLD FRONT SHOULD CONTINUE TO MOVE SEWD ACROSS ARKLATEX REGION...AND CENTRAL/SW TX. FRONT WILL MOVE MORE SLOWLY OVER CENTRAL/SERN NM...AND EXTEND NWWD INTO SFC LOW. ...TX... FAVORABLE LOW LEVEL AND DEEP-LAYER SHEAR...COMBINED WITH WEAK SFC-BASED BUOYANCY AND MINIMAL CINH...AIDED IN DEVELOPMENT OF STRONG SHOWERS AND A FEW TSTMS S OF COLD FRONT OVER CENTRAL TX. ONE OF THESE SPAWNED SMALL TORNADO NEAR I-35 IN BELL COUNTY...AT 2244Z. MODIFIED VWP AND RUC SOUNDINGS INDICATE 200-250 0-1 KM SRH...BENEATH 40-50 KT 500 MB FLOW THAT WILL CONTRIBUTE TO 40-45 KT 0-6 KM SHEAR. ALTHOUGH BRIEF TORNADO CANNOT BE RULED OUT FOR CONVECTION IN WARM SECTOR...ALREADY MRGL THERMODYNAMIC CONDITIONS WILL BECOME LESS FAVORABLE FROM NW-SE. IN ADDITION TO GRADUAL DIABATIC COOLING IN WARM SECTOR...STRONG DENSITY CURRENT BEHIND COLD FRONT IS FCST TO UNDERCUT ACTIVITY MOVING NNEWD ACROSS CENTRAL TX...AMIDST EFFECTIVELY ANAFRONTAL FLOW REGIME. ..EDWARDS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 05:43:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 00:43:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130546 SWODY1 SPC AC 130544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...SYNOPTIC SCALE TROUGH IS FCST TO REMAIN OVER WRN CONUS...AS EMBEDDED UPPER VORTEX NOW OVER NV/UT BORDER REGION MOVES/REDEVELOPS NEWD OVER WY. MEANWHILE...STRONG VORTICITY LOBE PIVOTING THROUGH BASE OF TROUGH MAY EVOLVE INTO CLOSED OR NEARLY CLOSED LOW FARTHER SW OVER 4-CORNERS AREA...BY 14/12Z. ALTHOUGH LATEST OPERATIONAL SPECTRAL/NAM AND VARIOUS SREF MEMBERS FROM 12/21Z RUN DIFFER SOME ON GEOMETRY AND RELATIVE STRENGTH OF EACH LOW...GENERAL SCENARIO IS IN GOOD AGREEMENT. THIS FOMENTS HIGH CONFIDENCE IN PRESENCE OF EXTENSIVE BELT OF MID-UPPER SWLYS FROM NRN MEX ACROSS SRN/CENTRAL PLAINS TO OH VALLEY THROUGH MOST OF PERIOD...JUXTAPOSED OVER BROAD REGIME OF LOW LEVEL WAA/MOISTURE TRANSPORT. AT SFC...INTENSE ARCTIC COLD FRONT -- NOW ANALYZED FROM SERN NM INTO CENTRAL TX THEN NEWD ACROSS SRN IL -- IS EXPECTED TO MOVE SLOWLY SWD ACROSS LOWER OH VALLEY...AR AND INTO S-CENTRAL TX. WEAK LOW MAY FORM AND MOVE NEWD ALONG FRONT...ACROSS AR...AS SRN STREAM MIDLEVEL PERTURBATION NOW OVER BAJA/NERN MEX EJECT NEWD. WRN SEGMENT OF FRONT OVER SW TX AND SERN NM MAY STALL OR DECELERATE CONSIDERABLY...WITH STRONG/PRIMARY SFC CYCLONE EXPECTED TO RE-FORM OVER CENTRAL NM BY LATE IN PERIOD. ...SE TX TO SRN AR... VERTICAL SHEAR PROFILES S OF FRONT WILL BE FAVORABLE FOR ANY SUSTAINED/DISCRETE CONVECTION TO ROTATE...ESPECIALLY IF SFC WINDS ARE BACKED SOMEWHAT BY WEAK FRONTAL-WAVE LOW DEVELOPMENT INDICATED IN SPECTRAL/NAM GUIDANCE. MAIN CONCERNS WILL BE CONVECTIVE MODE... PLACEMENT RELATIVE TO SFC-BASED INFLOW...AND LACK OF DEEPER AND MORE ROBUST BUOYANCY. NUMEROUS SHOWERS WITH EMBEDDED TSTMS MAY DEVELOP INVOF FRONT...LEAVING MOST PROBABLE AREA FOR DISCRETE DEVELOPMENT ASSOCIATED WITH WEAK BOUNDARY LAYER FORCING TO ITS S...DURING AFTERNOON. FCST SOUNDINGS INDICATE VERY SIMILAR REGIME TO THAT OVER CENTRAL TX PREVIOUS DAY...WITH MLCAPE PROFILES BELOW 500 J/KG IN MAGNITUDE AND REMAINING MOSTLY BELOW LAYERS MOST SUITABLE FOR CG LIGHTNING PRODUCTION. BRIEF TORNADO CANNOT BE RULED OUT...BUT PROBABILITIES APPEAR TOO LIMITED TO WARRANT CATEGORICAL SVR OUTLOOK ATTM. ...S-CENTRAL/SW TX... RELATIVE WEAKNESS IN LOW LEVEL VERTICAL SHEAR IS FCST OVER DEEP S TX AND S-CENTRAL TX...MAINLY DUE TO DESTRUCTIVE INFLUENCE OF RELATIVELY WEAK 1-3 KM AGL FLOW ON HODOGRAPH SIZE. THESE WEAKNESSES ARE LESS EVIDENT FARTHER NW TOWARD LOWEST PECOS VALLEY REGION...HOWEVER AFTERNOON SBCINH MAY BE STRONGER. REASONABLE PRESENCE OF SSELY-SELY SFC WINDS AND 40-50 KT WINDS IN MIDDLE PORTION OF BUOYANT PROFILES YIELDS FAVORABLE EFFECTIVE SHEARS OF 40-50 KT IN SUPPORT OF SOME STORM ORGANIZATION EVEN WHERE WEAKNESSES ARE EVIDENT ATOP BOUNDARY LAYER. WITH ANAFRONTAL NET FLOW REGIME...ACTIVITY FORMING S OF FRONT EFFECTIVELY MAY BE UNDERCUT BY FRONT...HOWEVER MRGL POTENTIAL FOR SFC-BASED SVR IN WARM SECTOR IS EVIDENT AND WILL BE REFLECTED IN UNCONDITIONAL PROBABILITIES. ALTHOUGH CAPPING WILL INCREASE WITH SWD EXTENT...HEATING MAY BE SUFFICIENT TO WEAKEN CINH AND SUPPORT DEVELOPMENT NEAR AND S OF FRONT...AND ALSO ALONG ERN SLOPES OF SERRANIAS DEL BURRO RANGE OF NRN MEX. ANY ACTIVITY DEVELOPING OVER MEX MOUNTAINS MAY MOVE NEWD ACROSS RIO GRANDE INTO S TX DURING LATE AFTERNOON/EARLY EVENING...HOWEVER EXTENSIVE MID/HIGH CLOUD COVER MAY RESTRICT HEATING OF HIGHER TERRAIN AND LIMIT OR PREVENT SUCH DEVELOPMENT. GIVEN THESE UNCERTAINTIES...SVR PROBABILITIES ARE KEPT MRGL FOR THIS AREA AS WELL. ..EDWARDS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 12:46:51 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 07:46:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131249 SWODY1 SPC AC 131247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST SAT JAN 13 2007 VALID 131300Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS INTO THE LOWER OH RIVER VALLEY... PAIR OF PROGRESSIVE SHORTWAVE TROUGHS CONTINUE TO EJECT OUT OF BROADER WRN U.S. TROUGH THIS MORNING. LEADING WAVE RESPONSIBLE FOR CONSIDERABLE RAIN/ZR/IP ACROSS THE SRN PLAINS INTO THE LOWER OH RIVER VALLEY WILL CONTINUE TO LIFT NEWD WITH DIMINISHING THUNDERSTORM POTENTIAL. SECOND IMPULSE APPEARED TO BE EJECTING ACROSS THE SRN HIGH PLAINS EARLY THIS MORNING. AT THE SURFACE...ARCTIC COLD FRONT NOW EXTENDING FROM THE LOWER OH RIVER VALLEY INTO THE ARKLATEX AND THE TX HILL COUNTRY AT 12Z. MODEL GUIDANCE INDICATES A WAVE WILL FORM ALONG THIS FRONT INTO SRN/SERN AR THROUGH THE AFTERNOON. LLJ WILL REMAIN ACROSS MOST OF ERN TX INTO THE LOWER OH RIVER VALLEY TODAY...BEFORE REFORMING FARTHER WEST OVERNIGHT IN RESPONSE TO MAIN UPPER TROUGH EXPECTED TO BEGIN EJECTING ENEWD LATE IN THE PERIOD. SIMILAR TO YESTERDAY...WARM SECTOR AIR MASS WILL BE SLOW TO DESTABILIZE TODAY WITH EXTENSIVE CONVECTION ACROSS MUCH OF AREA WITHIN PERSISTENT LOW LEVEL WAA. HOWEVER...DEEP LAYER SHEAR WILL REMAIN MORE THAN ADEQUATE FOR ROTATING STORMS UNDER MODERATE SWLY FLOW ALOFT AS EVIDENCED BY 12Z SHV SOUNDING. IN ADDITION...INFLUX OF LOWER/MID 60F SURFACE DEW POINTS AND POSSIBLE SURFACE PRESSURE FALLS FROM NERN TX INTO PORTIONS OF AR MAY SUPPORT STRONG TO MARGINALLY SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING ACROSS THIS AREA. FARTHER WEST TOWARDS THE BIG BEND REGION...DEEP LAYER SHEAR IS ALREADY QUITE STRONG ACCORDING TO 12Z SOUNDING AT DRT AND MID LEVEL LAPSE RATES ARE MODERATELY STEEP. HEATING WILL BE MODULATED BY MID LEVEL CLOUDS/MOISTURE FEEDING OFF THE PACIFIC. HOWEVER...LOW SEVERE PROBABILITIES ARE WARRANTED SHOULD SURFACE BASED CAPE BE REALIZED THIS AFTERNOON/EARLY EVENING AHEAD OF THE FRONT. ..EVANS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 16:27:22 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 11:27:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131630 SWODY1 SPC AC 131628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1028 AM CST SAT JAN 13 2007 VALID 131630Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... QUASI-STATIONARY UPPER LOW OVER THE GREAT BASIN IS EXPECTED TO BEGIN MOVING ESEWD TODAY AND REACH THE FOUR-CORNERS REGION BY LATE TONIGHT IN RESPONSE TO UPSTREAM SHORT WAVE TROUGH DROPPING SSEWD ACROSS THE PACIFIC NW. AT THE SURFACE...COLD FRONT EXTENDS FROM A WEAK LOW NEAR TXK SWWD THEN WWD ACROSS SOUTH CENTRAL TX...WITH A QUASI-STATIONARY FRONT NEWD FROM THE LOW INTO THE LOWER OH VALLEY. THE LOW IS FORECAST TO MOVE SLOWLY NEWD ALONG THE QUASI-STATIONARY FRONT AS THE TRAILING COLD FRONT MOVES SWD/SEWD ACROSS SERN/SOUTH CENTRAL TX THROUGH TONIGHT. ...SOUTH CENTRAL TX... SEVERAL NNE-SSW ORIENTED BANDS OF THUNDERSTORMS HAVE BEEN DEVELOPING OVER SOUTH CENTRAL TX SOUTH OF THE COLD FRONT WITH STORMS INTENSIFYING AS THEY CROSS THE FRONT AND MOVE NWD INTO A REGION OF ELEVATED INSTABILITY. THE CONVECTION MAY BE ASSOCIATED WITH INCREASED DYNAMIC FORCING AS A MID/UPPER LEVEL PERTURBATION EVIDENT IN WATER VAPOR IMAGERY MOVES NEWD TOWARD SWRN TX...WITH MESOSCALE ASCENT ENHANCED BY PERSISTENT LOW LEVEL WARM ADVECTION/ISENTROPIC LIFT ALONG/NORTH OF THE FRONT. SURFACE AIR MASS WITHIN WARM SECTOR IS WARM/MOIST WITH TEMPERATURES IN THE UPPER 60S/LOWER 70S AND DEW POINTS IN THE MID/UPPER 60S...RESULTING IN MLCAPE OF 500-1000 J/KG. ELEVATED INSTABILITY WITH MUCAPE OF 200-500 J/KG EXTENDS TO THE NORTH/NORTHWEST OF THE SURFACE FRONT. EXTENSIVE CLOUDS ARE EXPECTED TO INHIBIT DIABATIC HEATING THIS AFTERNOON...ALTHOUGH VISIBLE IMAGERY SHOWS SOME BREAKS IN CLOUD COVER CLOSER TO THE RIO GRANDE WHERE A FEW AREAS OF STRONGER HEATING/DESTABILIZATION MAY OCCUR. MODERATELY STRONG SWLY FLOW ALOFT WILL MAINTAIN SUFFICIENT DEEP LAYER SHEAR /35-45 KT IN THE LOWEST 6 KM/ TO ENHANCE STORM ORGANIZATION AND INTENSITY...SUGGESTING POTENTIAL FOR ISOLATED SEVERE STORMS TO OCCUR THROUGH THIS AFTERNOON INTO THE EVENING. THIS THREAT MAY BE LOCALLY INCREASED NEAR THE FRONT WHERE VERTICAL SHEAR WILL BE ENHANCED...SUGGESTING THREAT FOR A BRIEF TORNADO IN ADDITION TO MARGINAL HAIL OR STRONG WIND GUSTS. HOWEVER...STORMS ARE EXPECTED TO QUICKLY BECOME ELEVATED AS THEY MOVE NORTH OF THE FRONT. ADDITIONAL ELEVATED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER TONIGHT NORTH OF THE FRONT OVER PARTS OF WEST CENTRAL INTO CENTRAL TX AS LOW LEVEL JET DEVELOPS WWD INTO TX IN ASSOCIATION WITH THE UPPER LOW MOVING INTO THE FOUR-CORNERS REGION. MARGINAL HAIL MAY OCCUR WITH ISOLATED STORMS. ...SERN TX INTO SRN AR... A NARROW AXIS OF INSTABILITY IS IN PLACE ALONG AND IMMEDIATELY AHEAD OF THE FRONT FROM SERN TX INTO SRN AR. VISIBLE IMAGERY SHOWS BREAKS IN CLOUD COVER FROM EAST CENTRAL TX INTO NORTH CENTRAL LA WHERE DIURNAL HEATING WILL BE ENHANCED. HOWEVER...LAPSE RATES ARE EXPECTED TO REMAIN WEAK WHICH WILL LIMIT MLCAPE TO AOB 500 J/KG. 12Z NAM AND ETAKF CONTROL MEMBER FROM THE 09Z SREF INDICATE NEW CONVECTION DEVELOPING ALONG THE FRONT THIS AFTERNOON INTO THE EVENING WITHIN LOW CAPE/HIGH SHEAR ENVIRONMENT. THIS SUGGESTS THREAT FOR AN ISOLATED SEVERE STORM OR TWO TO DEVELOP...BUT WEAK INSTABILITY AND LIMITED FORCING FOR ASCENT SHOULD LIMIT OVERALL SEVERE POTENTIAL. ..WEISS.. 01/13/2007  From swody1 at goshenarc.org Sat Jan 13 19:43:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 14:43:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131947 SWODY1 SPC AC 131944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0144 PM CST SAT JAN 13 2007 VALID 132000Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH WILL CONTINUE SHIFTING EWD ACROSS THE ROCKIES THIS PERIOD...WITH EMBEDDED UPPER LOW TO REACH THE FOUR CORNERS REGION BY THE END OF THE PERIOD. AT THE SURFACE...COLD FRONT WILL CONTINUE MOVING SWD ACROSS SRN AND ERN TX...WITH SUBTLE LOW LIKELY TO PERSIST INVOF SRN AR ALONG FRONT THROUGH THE PERIOD. ...MIDDLE RIO GRANDE VALLEY/PARTS OF S TX NEWD INTO NRN LA/SRN AR... SHOWERS AND SCATTERED THUNDERSTORMS ARE ONGOING ATTM WITHIN MARGINAL/ELEVATED INSTABILITY N OF SURFACE FRONT...WHICH NOW EXTENDS FROM A WEAK LOW IN SWRN AR SSWWD ACROSS E TX...AND THEN WWD ACROSS SRN PORTIONS OF THE HILL COUNTRY TO NEAR DRT. AOB 1000 J/KG MEAN-LAYER CAPE IS INDICATED ACROSS DEEP S TX FROM ROUGHLY SAT SWD...THOUGH AIRMASS REMAINS CAPPED ATTM. THIS CAPPING SHOULD CONTINUE TO GENERALLY INHIBIT CONVECTIVE DEVELOPMENT S OF FRONT THROUGH THE PERIOD. GREATEST POTENTIAL FOR THUNDERSTORMS REMAINS N OF FRONT...WHERE WARM ADVECTION/ISENTROPIC LIFT PROVIDES SUFFICIENT LOW-LEVEL ASCENT FOR STORM INITIATION. HOWEVER...MUCH WEAKER INSTABILITY N OF BOUNDARY SUGGESTS ONLY A LIMITED HAIL THREAT -- MAINLY FROM THE RIO GRANDE VALLEY EWD ACROSS THE HILL COUNTRY. ANY STORMS WHICH COULD DEVELOP NEAR OR JUST S OF FRONT WOULD QUICKLY BE CARRIED NNEWD ACROSS THE BOUNDARY ACROSS THIS REGION...SO SURFACE-BASED SEVERE THREAT SHOULD REMAIN QUITE LOW. FURTHER NE...FRONT IS ORIENTED SSW-NNE ACROSS E TX. IN THIS REGION...MUCH MORE LIMITED INSTABILITY AND LOW-LEVEL CAP IS HINDERING THE POTENTIAL FOR ORGANIZED STORMS...DESPITE FAVORABLE DEEP-LAYER SHEAR. HOWEVER...WILL MAINTAIN LOW-PROBABILITY THREAT FOR AN ISOLATED WIND GUST OR WEAK/BRIEF TORNADO...AS CELL MOTION WOULD MORE CLOSELY PARALLEL THE FRONT AND PERHAPS ALLOW A STORM TO REMAIN SURFACE-BASED AS IT SHIFTS NNEWD. ..GOSS.. 01/13/2007  From swody1 at goshenarc.org Sun Jan 14 00:38:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 13 Jan 2007 19:38:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140041 SWODY1 SPC AC 140039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST SAT JAN 13 2007 VALID 140100Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SERN TX NEWD INTO NRN LA/SRN AR... 00Z SFC ANALYSIS PLACES A WEAK FRONTAL WAVE JUST W OF KSHV. THIS WAVE WILL TRANSLATE NEWD INTO THE MID-SOUTH LATER TONIGHT. SFC COLD FRONT IS THEN EXPECTED TO RESUME A FASTER SEWD MOTION ACROSS THE UPPER TX COAST AND NRN LA/SRN AR BY 12Z. SRN PORTION OF THIS FRONT WILL BE SLOWER TO ADVANCE SWD THROUGH SCNTRL/DEEP S TX. STRONGEST LLJ MAX WILL LIKELY TRANSLATE NEWD FROM E TX THIS EVE INTO THE MID-SOUTH OVERNIGHT IN TANDEM WITH THE FRONTAL WAVE. UNTIL THEN...WARM ADVECTION ENHANCED SFC-BASED TSTMS WILL CONTINUE TO FORM AHEAD OF THE FRONT. 0-1KM SRH OF 150-200 M2/S2 COINCIDENT WITH A MOIST BOUNDARY LAYER WILL BE SUFFICIENT TO MAINTAIN A LOW PROBABILITY OF AN ISOLD TORNADO IN ADDITION TO RISKS OF ISOLD DAMAGING WINDS. BUT...THERE WILL BE A TENDENCY FOR THE ADVANCING COLD AIR TO UNDERCUT THE UPDRAFTS AND REDUCE THE SEVERE THREATS WITH ANY GIVEN UPDRAFT. THUS...THE PRIMARY HAZARD WILL LIKELY REMAIN HVY RNFL. FARTHER S...PROMINENT CAP AROUND THE H85 LEVEL S OF THE COLD FRONT AND LACK OF STRONGER LARGE SCALE FORCING WILL REDUCE THE CHANCES FOR TSTMS. ELSEWHERE...LATER TONIGHT...CONVECTION WILL INCREASE ACROSS PARTS WCNTRL...NWRN AND CNTRL TX BETWEEN 09-12Z AS A BRANCH OF THE LLJ BACKS AND INCREASES AHEAD OF THE SRN ROCKIES IMPULSE. TSTMS WILL BE POSSIBLE AS THE COLUMN SATURATES. 00Z SOUNDINGS SHOW 3-6 KM LAPSE RATES IN EXCESS OF 7 DEG C PER KM FURTHER LENDING CONFIDENCE FOR AT LEAST LOW TSTM PROBABILITIES. ..RACY.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 05:41:55 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 00:41:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140545 SWODY1 SPC AC 140542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1142 PM CST SAT JAN 13 2007 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...S AND E TX NEWD INTO THE MID-SOUTH... THE UPPER LEVEL IMPULSE LOCATED ACROSS AZ IS EXPECTED TO EJECT ENEWD TO THE CNTRL PLAINS BY SUNDAY NIGHT AS A NEW SPEED MAX DROPS SEWD INTO THE SWRN DESERTS. ATTENDANT UPPER LEVEL JET OF 150+ KTS WILL PROPAGATE NEWD ALONG THE BASE OF THE TROUGH WITH THE ENTRANCE REGION SPREADING ACROSS THE SRN PLAINS. SUBTROPICAL MOISTURE PLUME WAS WELL-ESTABLISHED FROM SCNTRL TX NEWD INTO THE LWR OH/MS VLYS PER 00Z RAOBS. AS AGEOSTROPHIC FORCING DEVELOPS EARLY SUNDAY IN RESPONSE TO THE UPSTREAM TROUGH...NWRN PORTION OF THIS PLUME WILL LIKELY BE THE IMPETUS FOR INCREASING CONVECTION/TSTMS. AT THE SFC...THE MODIFIED ARCTIC COLD FRONT SHOULD BECOME QUASI-STATIONARY FROM SERN AR TO THE UPPER TX COAST AND SCNTRL TX THROUGH SUNDAY AFTN. PROSPECTS FOR WARM SECTOR TSTM DEVELOPMENT DO NOT APPEAR ROBUST. STRONG INSTABILITY WILL EXIST ACROSS DEEP S TX WHERE PRE-FRONTAL AIR MASS WILL BE CHARACTERIZED BY TEMPERATURES NEAR 80F AND DEW POINTS NEAR 68F. PRESENCE OF A CAP AND WEAK DEEP LAYER ASCENT...HOWEVER... SHOULD PRECLUDE SFC-BASED STORMS. JUST TO THE N OF THE FRONT... FORECAST SOUNDINGS SUGGEST THAT AVAILABLE CAPE WILL BE MINIMAL. THUS...DESPITE SUFFICIENT EFFECTIVE SHEAR FOR ORGANIZED STORMS...HAIL RISKS SEEM LOW ACROSS SCNTRL-ECNTRL TX. FINALLY... FARTHER EAST ACROSS PORTIONS OF THE MID-SOUTH...POOR LAPSE RATES ARE EXPECTED TO REMAIN IN PLACE AND UPDRAFTS SHOULD NOT BE PARTICULARLY STRONG DESPITE INCREASING VERTICAL SHEAR. ..RACY.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 12:39:01 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 07:39:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141242 SWODY1 SPC AC 141239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 AM CST SUN JAN 14 2007 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...S AND E TX NEWD INTO THE MID-SOUTH... THE UPPER LEVEL IMPULSE LOCATED ACROSS AZ IS EXPECTED TO EJECT ENEWD TO THE CNTRL PLAINS BY SUNDAY NIGHT AS A NEW SPEED MAX DROPS SEWD INTO THE SWRN DESERTS. ATTENDANT UPPER LEVEL JET OF 150+ KTS WILL PROPAGATE NEWD ALONG THE BASE OF THE TROUGH WITH THE ENTRANCE REGION SPREADING ACROSS THE SRN PLAINS. SUBTROPICAL MOISTURE PLUME WAS WELL-ESTABLISHED FROM SCNTRL TX NEWD INTO THE LWR OH/MS VLYS THIS MORNING PER 12Z RAOBS. AS AGEOSTROPHIC FORCING DEVELOPS IN RESPONSE TO THE UPSTREAM TROUGH...NWRN PORTION OF THIS PLUME WILL LIKELY BE THE IMPETUS FOR INCREASING CONVECTION/TSTMS. AT THE SFC...THE MODIFIED ARCTIC COLD FRONT SHOULD BECOME QUASI-STATIONARY FROM SERN AR TO THE UPPER TX COAST AND SCNTRL TX THROUGH SUNDAY AFTN. PROSPECTS FOR WARM SECTOR TSTM DEVELOPMENT DO NOT APPEAR ROBUST. STRONG INSTABILITY WILL EXIST ACROSS DEEP S TX WHERE PRE-FRONTAL AIR MASS WILL BE CHARACTERIZED BY TEMPERATURES NEAR 80F AND DEW POINTS NEAR 68F. PRESENCE OF A CAP AND WEAK DEEP LAYER ASCENT...HOWEVER... SHOULD PRECLUDE SFC-BASED STORMS. JUST TO THE N OF THE FRONT... FORECAST SOUNDINGS SUGGEST THAT AVAILABLE CAPE WILL BE MINIMAL. THUS...DESPITE SUFFICIENT EFFECTIVE SHEAR FOR ORGANIZED STORMS...HAIL RISKS SEEM LOW ACROSS SCNTRL-ECNTRL TX. FINALLY... FARTHER EAST ACROSS PORTIONS OF THE MID-SOUTH...POOR LAPSE RATES ARE EXPECTED TO REMAIN IN PLACE AND UPDRAFTS SHOULD NOT BE PARTICULARLY STRONG DESPITE INCREASING VERTICAL SHEAR. ..RACY/EVANS.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 15:45:13 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 10:45:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141548 SWODY1 SPC AC 141545 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0945 AM CST SUN JAN 14 2007 VALID 141630Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG IMPULSE IN PROCESS OF LIFTING NEWD OUT OF WRN U.S. TROUGH POSITION AND WILL BE TRACKING ACROSS THE PLAINS INTO THE MID MS VALLEY THIS FORECAST PERIOD. WHILE THE LEADING EDGE OF THE SHALLOW ARCTIC AIR MASS HAS REACHED ALMOST TO UPR TX COAST WWD ACROSS FAR S TX...THERE REMAINS A STRONG SLY FLOW OF VERY MOIST AIR JUST ABOVE THE COLD DOME NWD INTO ERN OK/AR. MODELS IN REASONABLE AGREEMENT THAT A SURFACE LOW WILL FINALLY DEVELOP TONIGHT TO E OF THE SHALLOW COLD DOME OVER MID MS VALLEY WITH THE APPROACH OF THE UPPER SUPPORT NOW MOVING INTO SRN/CENTRAL PLAINS. ELEVATED THUNDERSTORMS HAVE RAPIDLY DEVELOPED THIS AM WRN OK INTO NWRN TX WITH THE MID LEVEL COOLING AND STRONG LARGE SCALE ASCENT ASSOCIATED WITH THE APPROACH OF THE S/WV TROUGH. WHILE THERE IS AN UNSEASONABLY MOIST AIR MASS IN PLACE ACROSS LWR MS INTO LOWER OH VALLEY...IT IS CHARACTERIZED BY WEAK LAPSE RATES AND LIMITED POTENTIAL FOR SURFACE HEATING WITH THE EXTENSIVE CLOUD COVER. POTENTIAL FOR SEVERE THUNDERSTORMS VERY LIMITED BOTH ELEVATED AND SURFACE BASED GIVEN THE WEAK LAPSE RATES AND INSTABILITY. HOWEVER PRIMARILY ELEVATED THUNDERSTORMS WILL EXPAND EWD ACROSS SRN PLAINS INTO MS VALLEY THRU THE FORECAST PERIOD. ..HALES.. 01/14/2007  From swody1 at goshenarc.org Sun Jan 14 19:47:52 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 14:47:52 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141950 SWODY1 SPC AC 141948 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0148 PM CST SUN JAN 14 2007 VALID 142000Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY-TILTED UPPER TROUGH OVER THE ROCKIES WILL CONTINUE MOVING EWD...WHILE SURFACE COLD FRONT PRESSES SWD ACROSS THE S CENTRAL CONUS AS SURFACE WAVE SHIFTS NEWD TOWARD THE OH VALLEY. WARM ADVECTION ABOVE THIS BOUNDARY WILL YIELD A CONTINUED POTENTIAL FOR SHOWERS AND ISOLATED THUNDERSTORMS -- PARTICULARLY ACROSS TX WHERE MARGINAL ELEVATED INSTABILITY WILL PERSIST. ...PARTS OF OK/AR/ERN HALF OF TX/LA... LIGHTNING COVERAGE CONTINUES TO WANE ATTM...AS AREA OF ENHANCED PRECIPITATION -- APPARENTLY ASSOCIATED WITH SUBTLE VORT MAX EVIDENT IN IR IMAGERY MOVING NEWD ACROSS THE ARKLATEX -- SHIFTS NEWD. THOUGH OVERALL THUNDERSTORM COVERAGE SHOULD REMAIN LOW...SOME CONVECTIVE INCREASE MAY OCCUR ACROSS CENTRAL/S TX THE REMAINDER OF THE PERIOD...AS UPPER WAVE -- NOW MOVING ACROSS NWRN MEXICO TOWARD THE TX BIG BEND -- CONTINUES ENEWD. ..GOSS.. 01/14/2007  From swody1 at goshenarc.org Mon Jan 15 00:35:09 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 14 Jan 2007 19:35:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150038 SWODY1 SPC AC 150035 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST SUN JAN 14 2007 VALID 150100Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL TX NEWD INTO THE OZARKS... WATER VAPOR IMAGERY AND RUC ANALYSIS PLACE ANOTHER UPPER LEVEL SPEED MAX MOVING ACROSS NRN MEXICO. CLOUD TOPS HAVE COOLED ACROSS CNTRL/NCNTRL TX WITH INCREASING PCPN RATES AS THIS IMPULSE TRANSLATES NEWD. PRIMARY SUB-TROPICAL MOIST PLUME HAS SHIFTED EWD...ARCING FROM THE UPPER TX COAST NEWD ACROSS CNTRL-NERN TX TO THE LWR OH VLY. 00Z MAF/DRT/CRP/OUN SOUNDINGS SHOW THAT DRY AIR HAS ADVECTED EWD IN THE H85-H5 LAYER WITH SHV RAOB EXHIBITING MUCH MORE SUBSTANTIAL PWATS. PRIND ANAFRONTAL CONVECTION WILL CONTINUE THROUGH LATE TONIGHT...STRONGEST OF WHICH SHOULD MOVE FROM CNTRL/NCNTRL TX EARLY THIS EVE INTO THE OZARKS LATER TONIGHT. SUFFICIENT ELEVATED CAPE EXISTS IN THIS CORRIDOR TO SUPPORT SPORADIC LIGHTNING/TSTMS MAINLY BEFORE 06Z AND ESPECIALLY ACROSS NCNTRL/NERN TX INTO SWRN AR. ..RACY.. 01/15/2007  From swody1 at goshenarc.org Mon Jan 15 05:26:07 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 00:26:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150529 SWODY1 SPC AC 150527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST SUN JAN 14 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SCNTRL-ERN TX... CONFLUENT FLOW DEVELOPING ACROSS THE PLAINS IN WAKE OF A PROGRESSIVE NRN STREAM WAVE WILL HELP ACCELERATE A BAROCLINIC ZONE EWD TO THE ERN SEABOARD...THE SERN STATES AND OFF THE WRN GULF COAST BY MONDAY NIGHT. A WIDESPREAD AREA OF PCPN WILL ACCOMPANY THE FRONT...WITH MORE ROBUST ANA-FRONTAL TYPE CONVECTION RELEGATED TO THE WRN GULF COASTAL AREA CLOSER TO STEEPER MID-TROPOSPHERIC LAPSE RATES. HERE...AGEOSTROPHIC RESPONSES TO SUBTLE SUB-TROPICAL IMPULSES WILL MAINTAIN A FLOW OF HIGHER THETA-E PARCELS ATOP THE FRONTAL INVERSION AND RESULT IN THERMODYNAMIC PROFILES SUFFICIENT FOR SPORADIC TSTMS. PROBABILITIES WILL BE HIGHEST PRE-18Z AND MAINLY ACROSS SCNTRL-ERN TX. ..RACY.. 01/15/2007  From swody1 at goshenarc.org Mon Jan 15 12:42:05 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 07:42:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151244 SWODY1 SPC AC 151242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 AM CST MON JAN 15 2007 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... THUNDERSTORM POTENTIAL WILL REMAIN QUITE LIMITED ACROSS THE NATION THROUGH THE PERIOD GIVEN THE DEARTH OF INSTABILITY FORECAST. HOWEVER...MOIST CONVECTION WILL PERSIST ACROSS CENTRAL TX WITHIN BROAD MID LEVEL MOIST PLUME. APPEARS INSTABILITY WILL REMAIN SUFFICIENT FOR ISOLATED LIGHTNING STRIKES WITH THIS ACTIVITY OVER PARTS OF CENTRAL TX WHERE 12Z DRT SOUNDING MAINTAINS WEAK ELEVATED INSTABILITY. ..EVANS.. 01/15/2007  From swody1 at goshenarc.org Tue Jan 16 00:33:41 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 15 Jan 2007 19:33:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160036 SWODY1 SPC AC 160034 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CST MON JAN 15 2007 VALID 160100Z - 161200Z ...NO TSTM AREAS FORECAST... NRN COMPONENT OF POSITIVE-TILT LARGE SCALE TROUGH WILL CONTINUE DEVELOPING E FROM THE OH VLY/GRTLKS REGIONS THROUGH TONIGHT. AN EXTENSIVE SWATH OF PRIMARILY POST-FRONTAL PRECIPITATION CONTINUES FROM THE LWR MS VLY TO NEW ENGLAND. THIS WILL SPREAD E TOWARD THE MID-ATLANTIC COAST THROUGH 12Z TUE. DESPITE MODEST FORCING FOR ASCENT ACCOMPANYING THE UPPER TROUGH AND SFC FRONT...WEAK LAPSE RATES/MEAGER BUOYANCY WILL MITIGATE TSTMS TONIGHT. ..RACY/CARBIN.. 01/16/2007  From swody1 at goshenarc.org Tue Jan 16 05:02:36 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 16 Jan 2007 00:02:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160505 SWODY1 SPC AC 160503 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1103 PM CST MON JAN 15 2007 VALID 161200Z - 171200Z ...NO TSTM AREAS FORECAST... CONFLUENT FLOW ALOFT WILL CONTINUE TO BE FAVORABLE FOR THE MODIFIED CA/CP AIR MASS TO SURGE SEWD ACROSS THE SERN STATES AND INTO THE FL PENINSULA TUE AFT/NIGHT. A FEW SHOWERS MAY ACCOMPANY THE FRONT...BUT FCST SOUNDINGS IN THE WARM SECTOR ACROSS FL EXHIBIT WARM MID-TROPOSPHERIC TEMPERATURES THAT WILL PRECLUDE DEEP CONVECTION/ TSTMS. ELSEWHERE...TSTMS ARE NOT EXPECTED. ..RACY.. 01/16/2007  From swody1 at goshenarc.org Fri Jan 19 05:40:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 00:40:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 190543 SWODY1 SPC AC 190540 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST THU JAN 18 2007 VALID 191200Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... LATE EVENING MODEL GUIDANCE CONTINUES TO SUGGEST UPPER LOW WILL BEGIN EJECTING EWD ACROSS THE NRN BAJA PENINSULA SHORTLY AFTER 12Z...THEN LIFT NEWD INTO SRN AZ BY THE END OF THE PERIOD. SUSTAINED ASCENT WITHIN EXIT REGION OF UPPER JET SHOULD MOISTEN PROFILES THROUGH A DEEP LAYER ACROSS THE SRN HALF OF AZ...WHILE LAPSE RATES STEEPEN WITHIN COOLING COLUMN. EVEN SO...FORECAST SOUNDINGS ONLY WEAKLY DESTABILIZE THIS REGION AND SUSPECT CONVECTION SHOULD GENERALLY REMAIN TOO SHALLOW FOR WIDESPREAD THUNDERSTORMS. MOST THUNDERSTORM ACTIVITY WILL BE CONCENTRATED SOUTH OF THE AZ BORDER...BUT ISOLATED LIGHTNING MAY EVOLVE TO THE NORTH-EAST OF THE MAIN UPPER LOW...ESPECIALLY DURING THE LATTER HALF OF THE PERIOD. ..DARROW.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 12:47:20 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 07:47:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191249 SWODY1 SPC AC 191247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST FRI JAN 19 2007 VALID 191300Z - 201200Z ...NO SVR TSTM AREAS FORECAST... MORNING WATER VAPOR LOOPS SHOW CLOSED UPPER LOW OVER NORTHERN BAJA...WITH BROAD PLUME OF SUBTROPICAL MOISTURE EXTENDING ACROSS NORTHERN MEXICO INTO THE SOUTHERN PLAINS. MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE ONLY AREA WHERE SUFFICIENT DESTABILIZATION CAN OCCUR FOR A RISK OF THUNDERSTORMS WILL BE ACROSS PARTS OF AZ/NM. PROLONGED UVVS AHEAD OF UPPER LOW...COMBINED WITH STEEPENING LAPSE RATES WILL RESULT IN MARGINAL ELEVATED CAPE VALUES...DESPITE VERY LIMITED MOISTURE. SCATTERED SHOWERS AND ISOLATED LIGHTNING STRIKES ARE POSSIBLE FROM CENTRAL AZ THIS AFTERNOON...INTO WESTERN NM TONIGHT. NO SEVERE STORMS ARE FORECAST. ELSEWHERE...NO ORGANIZED THUNDERSTORM ACTIVITY IS FORECAST TODAY ACROSS THE NATION. ..HART.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 16:02:47 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 11:02:47 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 191605 SWODY1 SPC AC 191602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST FRI JAN 19 2007 VALID 191630Z - 201200Z ...NO SVR TSTM AREAS FORECAST... COLD CUT-OFF LOW CURRENTLY OVER NRN BAJA EXPECTED TO SHOW A GRADUAL INCREASE IN EWD MOTION AS HEIGHT FALLS MOVE INTO PAC NW. INCREASING MOISTURE IN STRONG SLY FLOW AHEAD OF LOW CENTER IS SPREADING N/NE INTO SRN AZ/NM. THE INSTABILITY SUFFICIENT FOR A THUNDER THREAT CURRENTLY LOCATED IN MEXICO WITH AND JUST TO E OF UPPER LOW. WITH THE COLD CORE LOW TRACKING ACROSS SERN CORNER OF AZ TONIGHT...A FEW THUNDERSTORMS WILL BE POSSIBLE EMBEDDED BOTH WITHIN THE PLUME OF MOISTURE AHEAD OF THE LOW AND THE STEEP LAPSE RATES WITH THE LOW TONIGHT. ..HALES.. 01/19/2007  From swody1 at goshenarc.org Fri Jan 19 19:58:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 14:58:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 192001 SWODY1 SPC AC 191958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST FRI JAN 19 2007 VALID 192000Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... MID AND UPPER LEVEL LOW SLOWLY DRIFTING SSEWD OVER NRN BAJA IS FORECAST TO ACCELERATE IN MORE OF AN ELY DIRECTION TONIGHT IN RESPONSE TO INCREASING HEIGHT FALLS FROM THE PACIFIC NW INTO GREAT BASIN. CYCLONICALLY CURVED PRECIPITATION BAND IS ONGOING AS OF 1930Z FROM THE SERN PART OF THE STATE WNWWD THROUGH THE PHX METRO TO BLH WITHIN ZONE OF DEEP LAYER FORCING FOR ASCENT AHEAD AND N OF UPPER LOW. HOWEVER...PRIMARY REGION OF DEEP...MOIST CONVECTION REMAINS CONFINED TO NEAR THE CENTER OF AND ALONG THE SWRN/SRN PERIPHERY OF CIRCULATION FROM JUST OFF THE BAJA COAST TO THE NRN GULF OF CA. PROXIMITY RUC SOUNDINGS INDICATE THAT MID LEVEL LAPSE RATES REMAIN QUITE WEAK /AOB 6.5 C PER KM/ OVER SERN INTO CNTRL AZ. WITH APPROACH OF UPPER LOW...EXPECT THAT THESE LAPSE RATES WILL STEEPEN...SUPPORTING POCKETS OF WEAK CONVECTIVE INSTABILITY AND AN ISOLATED THUNDER THREAT LATER THIS AFTERNOON AND TONIGHT. ..MEAD.. 01/19/2007  From swody1 at goshenarc.org Sat Jan 20 00:39:32 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 19 Jan 2007 19:39:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200042 SWODY1 SPC AC 200039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST FRI JAN 19 2007 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...AZ... EARLY EVENING MODEL GUIDANCE SUGGESTS CENTER OF UPPER CIRCULATION IS LOCATED OVER THE NRN BAJA PENINSULA/NRN GULF OF CALIFORNIA...ABOUT 200 S OF YUM. THIS FEATURE WILL SOON EJECT ENEWD ACROSS NRN MEXICO TO NEAR THE AZ/NM/MEXICO BORDER BY THE END OF THE PERIOD. ROUGHLY 4 BANDS OF DEEP CONVECTION HAVE DEVELOPED WITHIN THE NERN QUAD OF THIS LARGE SCALE CIRCULATION INTO CNTRL PORTIONS OF AZ...WITH ISOLATED LIGHTNING NOW LIMITED TO THE TWO BANDS ACROSS NWRN MEXICO. EVEN SO...THIS ACTIVITY IS DECREASING IN INTENSITY AND NOW MOSTLY NEAR THE LOW CENTER. 00Z SOUNDING FROM TUS SUGGESTS THUNDER POTENTIAL WILL BE RELATIVELY LOW THE REST OF THE PERIOD AS INSTABILITY IS VERY WEAK AND BOUNDARY LAYER WILL SOON BEGIN TO COOL. ..DARROW.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 05:15:27 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 00:15:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200518 SWODY1 SPC AC 200515 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... WELL DEFINED UPPER LOW OVER NWRN MEXICO WILL FINALLY EJECT NEWD INTO THE TX PANHANDLE LATE IN THE PERIOD AS STRONG SPEED MAX DEVELOPS OVER THE SRN PLAINS REGION INTO CNTRL OK. THIS FEATURE WILL UNDOUBTEDLY ENHANCE LARGE SWATH OF PRECIPITATION...AND ELEVATED CONVECTION ACROSS PORTIONS OF THE SRN ROCKIES INTO THE HIGH PLAINS REGION...INVOF THE UPPER LOW. HOWEVER...SHALLOW NATURE OF THE ELEVATED CONVECTION SUGGESTS LIGHTNING POTENTIAL IS QUITE LOW WITH THIS FEATURE. FARTHER SOUTH...LOW LEVEL WARM ADVECTION WILL INCREASE MARKEDLY ACROSS THE UPPER TX COAST INTO SRN LA AS WEAK SFC WAVE FORMS OFFSHORE IN THE NWRN GULF OF MEXICO. HOWEVER...POOR MID LEVEL LAPSE RATES SUGGEST WEAK INSTABILITY ACROSS THIS REGION WILL RESULT IN SHOWERS INCAPABLE OF GENERATING LIGHTNING. ..DARROW.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 15:47:26 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 10:47:26 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201552 SWODY1 SPC AC 201549 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0949 AM CST SAT JAN 20 2007 VALID 201630Z - 211200Z ...NO TSTM AREAS FORECAST... SWRN CUT-OFF LOW NOW ON THE MOVE AND WILL TRACK FROM CURRENT LOCATION OVER SWRN NM NEWD ACROSS ERN KS LATER TONIGHT AS IT OPENS INTO A TROUGH. ALTHOUGH GULF MOISTURE IS BEING DRAWN NWD INTO SRN PLAINS AHEAD OF UPPER SYSTEM...WEAK LAPSE RATES AND EXTENSIVE CLOUD COVER WILL INHIBIT DEVELOPMENT OF INSTABILITY SUFFICIENT TO SUPPORT THUNDERSTORMS. STEEP MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER LOW AS IT MOVES ACROSS ERN NM/TX PANHANDLE LATER THIS AFTERNOON COULD SUPPORT SOME CONVECTIVE PRECIPITATION. HOWEVER OTHER THAN ISOLATED STRIKES...THUNDERSTORMS THREAT IS MINIMAL. ..HALES.. 01/20/2007  From swody1 at goshenarc.org Sat Jan 20 19:37:41 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 14:37:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201942 SWODY1 SPC AC 201940 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST SAT JAN 20 2007 VALID 202000Z - 211200Z ...NO TSTM AREAS FORECAST... ...SRN PLAINS... WATER VAPOR IMAGERY AND RUC OBJECTIVE FIELDS INDICATE VORTICITY MAXIMUM EJECTING NEWD ACROSS ERN NM/WRN TX IN ADVANCE OF PRIMARY MID/UPPER LEVEL LOW CURRENTLY OVER WRN/CNTRL NM. REGIONAL 12Z RAOBS AND 18Z SUPPLEMENTAL SOUNDINGS INDICATE THE EXISTENCE OF POOR LAPSE RATES EXCEPT INVOF MID-LEVEL COLD POOL /REF. 12Z TUS SOUNDING/ OVER ERN AZ. WHILE NO ORGANIZED THUNDER THREAT IS ANTICIPATED THROUGH 21/12Z...POTENTIAL WILL EXIST FOR ISOLATED LIGHTNING STRIKES WITHIN ZONE OF STRONG FORCING ASSOCIATED WITH LEAD VORTICITY MAXIMUM AS WELL AS WITH MAIN LOW CENTER WHERE STEEPER MID-LEVEL LAPSE RATES WILL BE COINCIDENT WITH MOIST ASCENT. ELSEWHERE...TEMPERATURE AND RESULTANT LAPSE RATE PROFILES ARE EXPECTED TO REMAIN WARM/WEAK WITHIN WARM CONVEYOR PRECIPITATION BAND WHICH WILL BECOME MORE EXPANSIVE OVER THE SABINE INTO LOWER MS VALLEYS OVERNIGHT. NO THUNDER IS FORECAST. ..MEAD.. 01/20/2007  From swody1 at goshenarc.org Sun Jan 21 00:38:56 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 20 Jan 2007 19:38:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210043 SWODY1 SPC AC 210041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 PM CST SAT JAN 20 2007 VALID 210100Z - 211200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER TROUGH OVER THE WRN AND CENTRAL CONUS WILL MAKE SLOW EWD PROGRESS THROUGH THE END OF THE PERIOD...WHILE EMBEDDED/SMALLER-SCALE TROUGH MOVES ACROSS THE SRN PLAINS. A LARGE AREA OF MIXED WINTRY PRECIPITATION WILL CONTINUE ACROSS THE CENTRAL AND S CENTRAL CONUS...WHILE SPREADING EWD INTO THE MS VALLEY REGION OVERNIGHT. HOWEVER...LACK OF INSTABILITY SHOULD PRECLUDE ANY THREAT FOR THUNDERSTORMS. ..GOSS.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 05:56:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 00:56:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210601 SWODY1 SPC AC 210558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER TROUGH -- WHICH WILL INITIALLY CONSIST OF ONE FEATURE SHIFTING RAPIDLY NEWD TOWARD THE GREAT LAKES REGION AND THE OTHER DROPPING SSWWD TOWARD AZ -- WILL REMAIN OVER THE WEST THIS PERIOD. WITH TIME...THE ERN-MOST FEATURE WILL CONTINUE SHEARING NEWD...WHILE THE WRN FEATURE EVOLVES INTO A CLOSED LOW AS IT CROSSES AZ THROUGH THE PERIOD. AT THE SURFACE...MAIN FEATURE WILL BE A WEAK COLD FRONT...WHICH WILL MOVE SEWD ACROSS THE MID-SOUTH/LOWER MS VALLEY/SRN PLAINS THROUGH THE END OF THE PERIOD. THOUGH A LIGHTNING STRIKE OR TWO MAY OCCUR ACROSS THE DESERT SW NEAR THE EVOLVING UPPER LOW...SOMEWHAT GREATER THUNDER POTENTIAL SHOULD REMAIN LIMITED TO THE CENTRAL GULF COAST REGION. ...CENTRAL GULF COAST REGION AND VICINITY... MOISTENING BOUNDARY IS ANTICIPATED AHEAD OF WEAK/SEWD-MOVING COLD FRONT...THOUGH WEAK SHORT-WAVE RIDGING/SUBSIDENCE FORECAST ALOFT WILL CONTRIBUTE TO VERY WEAK LAPSE RATES. THIS SUGGESTS MINIMAL INSTABILITY...AND THEREFORE ONLY ISOLATED LIGHTNING STRIKES ARE EXPECTED THROUGH THE PERIOD. ..GOSS.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 12:43:09 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 07:43:09 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211248 SWODY1 SPC AC 211245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 AM CST SUN JAN 21 2007 VALID 211300Z - 221200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH REMAINS OVER THE CENTRAL UNITED STATES THIS MORNING...WITH INITIAL UPPER LOW LIFTING NORTHWARD INTO THE UPPER MS VALLEY WHILE A SECOND LOW DIGS SOUTHWARD INTO AZ. RELATIVELY DRY LOW LEVEL CONDITIONS ARE PRECLUDING ORGANIZED THUNDERSTORMS OVER MOST OF THE COUNTRY. THE ONE EXCEPTION WILL BE OVER THE CENTRAL GULF COAST REGION. ...CENTRAL GULF COAST REGION... MODEL GUIDANCE IS IN GENERAL AGREEMENT THAT WEAK SURFACE CYCLOGENESIS WILL OCCUR THIS AFTERNOON AND EVENING ALONG BAROCLINIC ZONE CURRENTLY OVER LA/MS. INCREASING SOUTHEASTERLY LOW LEVEL WINDS AHEAD OF BOUNDARY WILL HELP TO TRANSPORT MORE MOIST AND MARGINALLY UNSTABLE AIR MASS INTO PARTS OF SOUTHERN LA/MS/AL AND THE FL PANHANDLE /DEWPOINTS IN THE 50S TO NEAR 60F/. FORECAST SOUNDINGS IN THIS AREA SHOW NEAR MOIST-ADIABATIC LAPSE RATES AND ONLY VERY WEAK CAPE /GENERALLY LESS THAN 200 J/KG/. NEVERTHELESS...FORCING ALONG BOUNDARY MAY BE SUFFICIENT FOR CONTINUED SHOWERS AND ISOLATED THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. NO SEVERE STORMS ARE ANTICIPATED DUE TO LACK OF SUFFICIENT INSTABILITY. ...AZ... SCATTERED CONVECTION IS ALSO EXPECTED THIS AFTERNOON BENEATH COLD UPPER LOW OVER SOUTHERN AZ. FORECAST SOUNDINGS IN THIS AREA SUGGEST LOW-TOPPED SHOWERS ARE POSSIBLE...BUT POTENTIAL FOR MORE THAN AN ISOLATED LIGHTNING STRIKE IS TOO LOW TO OUTLOOK AT THIS TIME. ..HART.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 15:54:59 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 10:54:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211559 SWODY1 SPC AC 211557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0957 AM CST SUN JAN 21 2007 VALID 211630Z - 221200Z ...NO SVR TSTM AREAS FORECAST... THE REPLACEMENT COLD LOW CONTINUES TO SETTLE SWD THRU AZ THIS PERIOD AS LAST WEEKS CUT-OFF RAPIDLY BECOMES ABSORBED IN THE FAST FLOW ACROSS ERN U.S. A VERY MOIST RETURN FLOW GULF COAST STATES WILL PERSIST THRU TONIGHT...HOWEVER WEAK LAPSE RATE AND EXTENSIVE CLOUD COVER MINIMIZES THE DEVELOPMENT OF INSTABILITY SUFFICIENT TO SUPPORT ORGANIZED THUNDERSTORMS. WILL MAINTAIN A SMALL AREA OF THUNDER POTENTIAL ASSOCIATED WITH THE BAND OF LOW TOPPED CONVECTION NOW MOVING EWD ACROSS SERN LA INTO SERN MS. HOWEVER ANY LIGHTNING STRIKES EXPECTED TO BE LIMITED TO NEAR GULF COAST WHERE SOME WEAK CAPE IS POSSIBLE. WHILE STEEP LAPSE RATES UNDER DEVELOPING COLD LOW DROPPING SWD THRU AZ WILL LEAD TO CONVECTIVE SHOWERS THIS PM...LITTLE IF ANY LIGHTNING EXPECTED GIVEN THE VERY LIMITED MOISTURE AND INSTABILITY. ..HALES.. 01/21/2007  From swody1 at goshenarc.org Sun Jan 21 19:47:23 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 14:47:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211952 SWODY1 SPC AC 211949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN JAN 21 2007 VALID 212000Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF COAST... A BAND OF RELATIVELY SHALLOW CONVECTION IS ONGOING THIS AFTERNOON FROM SERN MS INTO FAR SERN LA...FOCUSED AHEAD OF WEAK SURFACE LOW NOW OVER S-CNTRL MS AND ATTENDANT FRONT/CONFLUENCE LINE STRETCHING SWD THROUGH SERN LA. MORE RECENT CONVECTION HAS DEVELOPED OFF THE COAST OF THE FL PNHDL...NEAR AND TO THE S OF WARM FRONT SLOWLY LIFTING NWD. 12Z OBSERVED AND CURRENT RUC FORECAST SOUNDINGS INDICATE THAT MID-TROPOSPHERE IS RATHER WARM RELATIVE TO BOUNDARY LAYER TEMPERATURE/MOISTURE PROFILES WITH RESULTING POOR LAPSE RATES AND QUITE WEAK CONVECTIVE INSTABILITY. AS SUCH...EXPECT THAT MAJORITY OF CONVECTION WILL REMAIN TOO SHALLOW TO SUPPORT CHARGE SEPARATION/LIGHTNING ACTIVITY. FORECAST SOUNDINGS DO SUGGEST THAT SUFFICIENT LOW LEVEL MOISTENING AND MID-LEVEL COOLING MAY OCCUR OVERNIGHT TO SUPPORT AN INCREASING THREAT OF ISOLATED TSTMS...MAINLY ACROSS THE FL PNHDL. THEREFORE...GENERAL THUNDER LINE HAS BEEN MAINTAINED. ..MEAD.. 01/21/2007  From swody1 at goshenarc.org Mon Jan 22 00:39:16 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 21 Jan 2007 19:39:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220044 SWODY1 SPC AC 220041 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 PM CST SUN JAN 21 2007 VALID 220100Z - 221200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... LARGE/POSITIVELY-TILTED UPPER TROUGH WILL PERSIST FROM THE GREAT LAKES SWWD INTO THE DESERT SW...WHILE EMBEDDED UPPER LOW WILL CONTINUE DROPPING SWD ACROSS AZ INTO FAR NWRN MEXICO BY THE END OF THE PERIOD. INSTABILITY REMAINS VERY MINIMAL -- BOTH INVOF THE UPPER LOW IN AZ AS WELL AS IN THE SEASONABLY-MOIST BOUNDARY LAYER WHICH HAS ADVECTED NWD INTO THE CENTRAL/ERN GULF COAST REGION. THIS LACK OF INSTABILITY WILL CONTINUE TO LIMIT ANY POTENTIAL FOR LIGHTNING...BOTH ACROSS AZ -- WHERE 3 CG STRIKES HAVE BEEN OBSERVED THIS AFTERNOON...AND ACROSS THE CENTRAL AND ERN GULF COAST REGION -- WHERE NO LIGHTNING HAS YET BEEN DETECTED. THEREFORE...WILL NOT INCLUDE ANY 10% THUNDER LINES FOR THE REMAINDER OF THIS FORECAST PERIOD. ..GOSS.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 05:54:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 00:54:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220559 SWODY1 SPC AC 220557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... NRN AND SRN STREAM UPPER TROUGHS -- INITIALLY PHASED AS A POSITIVELY-TILTED FEATURE EXTENDING FROM ERN CANADA/THE UPPER GREAT LAKES SWWD INTO THE DESERT SW -- ARE FORECAST TO SEPARATE INTO TWO DISTINCT FEATURES WITH TIME. THE NRN STREAM TROUGH IS FORECAST TO MOVE EWD/SEWD ACROSS ERN CANADA/THE NERN CONUS...WHILE THE SRN STREAM CLOSED LOW MOVES SLOWLY SEWD ACROSS THE SWRN U.S./NWRN MEXICO. A LIGHTNING STRIKE OR TWO WILL BE POSSIBLE N OF THE U.S./MEXICO BORDER...WHILE THE POTENTIAL FOR A FEW STRIKES WILL ALSO EXIST ACROSS SERN GA/NRN AND CENTRAL FL AHEAD OF WEAK COLD FRONT. ...SERN GA/NRN AND CENTRAL FL... WEAK INSTABILITY IS FORECAST TO DEVELOP AHEAD OF SURFACE FRONT...WHERE SEASONABLY-MOIST BOUNDARY LAYER /DEWPOINTS IN THE 60S/ WILL EXIST. DEGREE OF INSTABILITY...AND CONVERGENCE ALONG FRONT SHOULD BE SUFFICIENT FOR WEAK CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. HOWEVER...THUNDER THREAT SHOULD REMAIN QUITE LIMITED DUE TO WEAK INSTABILITY -- AND THE FACT THAT THE EQUILIBRIUM LEVEL OF MOST UPDRAFTS SHOULD REMAIN BELOW THE -20 C LEVEL -- IN THIS CASE FORECAST TO BE AROUND 25000 FT AGL. ...SERN AZ/SWRN NM/FAR W TX... STEEP LAPSE RATES/COLD MID-LEVEL TEMPERATURES ACCOMPANYING THE UPPER TROUGH WILL EXTEND ACROSS PARTS OF AZ/NM/FAR W TX AND INTO NWRN MEXICO THIS PERIOD...POSSIBLY RESULTING IN VERY WEAK CAPE ACROSS PORTIONS OF THIS AREA. A LIGHTNING STRIKE OR TWO MAY OCCUR N OF THE U.S./MEXICO BORDER FROM SERN AZ EWD TO FAR W TX INVOF UPPER LOW...THOUGH GREATER THREAT SHOULD REMAIN S OF THE BORDER THROUGH THE PERIOD. ..GOSS.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 13:14:34 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 08:14:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221319 SWODY1 SPC AC 221316 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0716 AM CST MON JAN 22 2007 VALID 221300Z - 231200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH REMAINS OVER THE UNITED STATES TODAY...WITH A GENERALLY COLD/DRY AIR MASS PRECLUDING THUNDERSTORMS IN MOST AREAS. ONLY PORTIONS OF SOUTHERN GA AND THE FL PENINSULA...AS WELL AS PARTS OF SOUTHERN NM/FAR WEST TX WILL HAVE A THREAT OF THUNDERSTORMS TODAY. ...GA/FL... MOIST AND MARGINALLY UNSTABLE CONDITIONS WILL BE PRESENT THROUGHOUT THE DAY ACROSS PORTIONS OF SOUTHERN GA AND THE FL PENINSULA...WHERE SCATTERED SHOWERS ARE FORECAST. MODEL SOUNDINGS IN THIS REGION SHOW NEAR MOIST-ADIABATIC LAPSE RATES AND CAPE VALUES BELOW 1000 J/KG. A FEW THUNDERSTORMS WILL LIKELY OCCUR IN THIS PRE-FRONTAL ZONE THIS AFTERNOON AND EVENING. HOWEVER...WARM TEMPERATURES ALOFT... RELATIVELY WEAK CAPE VALUES...AND POOR LAPSE RATES SHOULD LIMIT UPDRAFT STRENGTH AND SEVERE POTENTIAL. ...NM/TX... COLD UPPER LOW OVER SOUTHERN AZ AND NORTHERN MEXICO THIS MORNING WILL MOVE VERY LITTLE THROUGH THE FORECAST PERIOD. RELATIVELY STEEP LAPSE RATES WILL RESULT IN MARGINAL AFTERNOON INSTABILITY OVER PARTS OF SOUTHERN NM AND FAR WEST TX. SIMILAR TO YESTERDAY OVER AZ...AN ISOLATED LIGHTNING STRIKE OR TWO CANNOT BE RULED OUT IN STRONGER LOW-TOPPED SHOWERS. HOWEVER...FORECAST SOUNDINGS SHOW A RELATIVELY COLD AND DRY THERMODYNAMIC PROFILE THAT IS NOT FAVORABLE FOR ORGANIZED THUNDERSTORM ACTIVITY. ..HART.. 01/22/2007  From swody1 at goshenarc.org Mon Jan 22 15:44:53 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 22 Jan 2007 10:44:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221549 SWODY1 SPC AC 221546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0946 AM CST MON JAN 22 2007 VALID 221630Z - 231200Z ...NO SVR TSTM AREAS FORECAST... FRONTAL BAND WILL CONTINUE SETTLING SEWD ACROSS NRN INTO CENTRAL FL PENINSULA THIS FORECAST PERIOD. WARM SECTOR AHEAD OF FRONT IS CHARACTERIZED BY A WARM...MOIST AND WEAKLY UNSTABLE AIR MASS. WITH LAPSE RATES AROUND 5.5 C/KM AND MLCAPES GENERALLY LESS THAN 500 J/KG...CONVECTIVE ACTIVITY EXPECTED TO REMAIN WEAK BOTH ALONG THE FRONT AND ACROSS NRN FL IN THE WARM SECTOR. CONVECTION BY MID AFTERNOON...WHEN SURFACE TEMPERATURES REACH INTO THE LOW 80S...SHOULD BE DEEP ENOUGH FOR A FEW THUNDERSTORMS. ..HALES.. 01/22/2007  From swody1 at goshenarc.org Sun Jan 28 00:40:24 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 27 Jan 2007 19:40:24 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280045 SWODY1 SPC AC 280042 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 PM CST SAT JAN 27 2007 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF COAST...INCLUDING FL... EVENING WATER VAPOR IMAGERY INDICATES MIGRATORY SHORT WAVE TROUGH OVER THE ARKLATEX WITH AN ASSOCIATED BELT OF 50-60 KT MID-LEVEL FLOW PRESENT ACROSS THE GULF COAST AND NRN GULF OF MEXICO. THIS SHORT WAVE TROUGH WILL CONTINUE EWD ACROSS THE REGION OVERNIGHT TO NEAR THE ATLANTIC COAST BY 28/12Z. IN THE LOW-LEVELS...ASSOCIATED SURFACE LOW OFF THE SERN LA COAST IS FORECAST TO DEVELOP GENERALLY EWD TOWARD THE FL BIG BEND...PRIOR TO REDEVELOPING E/NE OF JAX BY THE END OF THE PERIOD. ATTENDANT WARM FRONT CURRENTLY EXTENDING FROM THIS LOW EWD ACROSS THE NERN GULF OF MEXICO AND THE NRN FL PENINSULA MAY LIFT SLIGHTLY NWD. LARGE PRECIPITATION SHIELD ONGOING ACROSS ERN MS/AL/GA/FL PNHDL INTO THE N-CNTRL/NERN GULF OF MEXICO IS EXPECTED TO CONTINUE TONIGHT AHEAD OF UPPER TROUGH...DRIVEN LARGELY BY WAA/ISENTROPIC UPGLIDE ABOVE SHALLOW SURFACE INVERSION. WHILE MOST OF THIS ACTIVITY WILL REMAIN ELEVATED...POTENTIAL WILL EXIST FOR SURFACE-BASED OR NEAR SURFACE-BASED STORMS TO MOVE ONTO THE FL PENINSULA LATER TONIGHT NEAR OR TO THE S OF SLOWLY RETREATING WARM FRONT. HERE...FORECAST SOUNDINGS INDICATE THAT LAPSE RATES AND RESULTANT INSTABILITY WILL REMAIN QUITE WEAK /SBCAPES AOB 300-400 J PER KG/...HOWEVER BOTH LOW AND DEEP-LAYER SHEAR WILL INCREASE MARKEDLY. AS SUCH...SOME THREAT FOR AN ISOLATED...BRIEF TORNADO OR WIND GUST WILL EXIST WITH ANY MORE ORGANIZED STORMS MOVING ONSHORE. THIS THREAT WILL BE LIMITED BY THE WEAK INSTABILITY AND TENDENCY FOR STORMS TO BE SLIGHTLY ELEVATED. THEREFORE...ONLY LOW PROBABILITIES WILL BE MAINTAINED. ..MEAD.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 05:25:28 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 00:25:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280530 SWODY1 SPC AC 280528 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST SAT JAN 27 2007 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... ERN CONUS LONG WAVE TROUGH /ANCHORED BY VORTEX OVER HUDSON BAY/ WILL BE MAINTAINED THROUGH THE PERIOD AS A SERIES OF SHORT WAVE TROUGHS/VORTICITY MAXIMA TRANSLATE THROUGH MEAN PATTERN. THE LEAD IMPULSE /CURRENTLY MOVING THROUGH THE GULF COAST REGION/ WILL MOVE OFFSHORE INTO THE ATLANTIC EARLY IN THE DAY ONE PERIOD. AS THIS OCCURS...INTENSE...UPSTREAM SHORT WAVE TROUGH WILL DIG SEWD FROM THE MIDWEST THROUGH THE CNTRL/SRN APPALACHIANS...EVENTUALLY INTO THE WRN ATLANTIC BY MONDAY MORNING. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO LEAD SHORT WAVE TROUGH WILL DEVELOP NNEWD ALONG/JUST E OF THE GULF STREAM WITH SECONDARY...WEAKER CYCLOGENESIS OCCURRING LATER IN THE PERIOD OFF THE NC/VA COASTS WITH APPROACH OF UPSTREAM SYSTEM. COLD FRONT ASSOCIATED WITH INITIAL SURFACE LOW WILL PUSH SEWD THROUGH THE FL PENINSULA SUNDAY MORNING. ...FL... AS MENTIONED ABOVE...INITIAL SHORT WAVE TROUGH WILL QUICKLY MOVE OFFSHORE WITH ATTENDANT SURFACE FRONT PUSHING SEWD THROUGH THE PENINSULA DURING THE MORNING HOURS. PRE-FRONTAL BAND OF CONVECTION WITH EMBEDDED ISOLATED/SCATTED TSTMS WILL LIKELY BE ONGOING AT THE ONSET OF THE FORECAST PERIOD WITHIN RELATIVELY MOIST/WEAKLY UNSTABLE ENVIRONMENT. DESPITE RATHER STRONG TROPOSPHERIC WIND FIELDS...VEERED...PRE-FRONTAL FLOW IN THE LOW-LEVELS COUPLED WITH WEAK LAPSE RATES AND THE MARGINAL INSTABILITY ARE EXPECTED TO PRECLUDE A SEVERE WEATHER THREAT. ELSEWHERE...ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE FROM THE CNTRL CA COAST EWD TOWARD THE SIERRAS IN ASSOCIATION WITH MID LEVEL LOW ENTRENCHED IN REX BLOCK OVER THE FAR ERN PACIFIC. TSTM POTENTIAL APPEARS TOO LIMITED TO WARRANT ADDITIONAL THUNDER AREA. ..MEAD.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 12:57:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 07:57:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281301 SWODY1 SPC AC 281258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST SUN JAN 28 2007 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD MEAN TROUGH WILL REMAIN OVER ERN NOAM THIS PERIOD...DOWNSTREAM FROM REX BLOCK OVER THE NE PACIFIC. POTENT NRN STREAM SHORTWAVE NOW NEARING CHICAGO SHOULD CONTINUE SE INTO THE SRN APLCNS TONIGHT... BEFORE TURNING MORE E OFF THE MID ATLANTIC CST TONIGHT/EARLY MONDAY. AS THIS OCCURS...WEAKER SRN BRANCH IMPULSE NOW OVER SC WILL CONTINUE TO BE ABSORBED IN FAST CONFLUENT FLOW DOWNSTREAM FROM MIDWEST DISTURBANCE. AT LOWER LEVELS...MAIN SFC WAVE ASSOCIATED WITH SC TROUGH IS NOW FORMING E OF CHARLESTON. THIS WAVE SHOULD ACCELERATE NEWD THROUGH THE DAY AS TRAILING COLD FRONT PROGRESSES E/SE ACROSS THE CNTRL/SRN FL PENINSULA. ...S FL THROUGH MIDDAY... SHALLOW COLD FRONT...AND PREFRONTAL CONFLUENCE AXIS OVER THE KEYS... WILL BE FOCI FOR MODEST CONVECTIVE DEVELOPMENT TODAY AS BOUNDARY LAYER WARMS AHEAD OF THESE FEATURES. DEPTH/STRENGTH OF CONVERGENCE WILL BE LIMITED AS SFC WAVE OFF THE SC CST LIFTS NE AWAY FROM REGION. COUPLED WITH RELATIVELY WEAK LOW TO MID LEVEL LAPSE RATES...ANY THUNDER SHOULD REMAIN WIDELY SCTD TO ISOLATED. ...MID ATLANTIC CSTL WATERS THIS EVENING... SCTD TSTMS SHOULD DEVELOP RAPIDLY LATER THIS EVENING THROUGH EARLY MONDAY OFF THE DELMARVA CST AS ZONE OF STRONG ASCENT/MID LEVEL COOLING ASSOCIATED WITH IMPULSE NOW NEAR CHICAGO OVERSPREADS REGION. THIS ACTIVITY SHOULD REMAIN OVER THE GULF STREAM GIVEN DRY OVERLAND AIR MASS AND WEAK LOW LEVEL CONVERGENCE. ...CNTRL CA... ISOLATED LIGHTNING WILL BE POSSIBLE FROM THE CNTRL CA COAST E TOWARD THE SIERRA IN ASSOCIATION WITH MID LEVEL LOW ENTRENCHED IN REX BLOCK OVER THE ERN PACIFIC. TSTM POTENTIAL APPEARS TOO LIMITED TO WARRANT A CATEGORICAL THUNDER FCST IN THIS AREA. ..CORFIDI.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 16:10:19 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 11:10:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281615 SWODY1 SPC AC 281612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1012 AM CST SUN JAN 28 2007 VALID 281630Z - 291200Z ...NO TSTM AREAS FORECAST... ...SERN FL COASTAL WATERS TO OFF THE MID ATLANTIC COAST... BAND OF THUNDERSTORMS PRECEEDING SURFACE COLD FRONT NOW MOVING ACROSS SERN FL WILL CONTINUE SHIFTING EWD AWAY FROM THE CONUS THIS AFTERNOON. VEERED SURFACE FLOW AND LIMITED INSTABILITY WILL LIKELY PRECLUDE FURTHER THUNDERSTORM DEVELOPMENT AHEAD OF THE COLD FRONT. OFFSHORE THUNDERSTORM DEVELOPMENT SHOULD INCREASE LATER THIS EVENING AND OVERNIGHT OVER THE GULF STREAM WATERS OFF THE NC/VA COAST AS LARGE SCALE ASCENT INCREASES AHEAD OF NEXT MID LEVEL IMPULSE NOW MOVING OUT OF THE MID WEST. ..EVANS.. 01/28/2007  From swody1 at goshenarc.org Sun Jan 28 19:30:04 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 14:30:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281934 SWODY1 SPC AC 281932 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0132 PM CST SUN JAN 28 2007 VALID 282000Z - 291200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... OFFSHORE FLOW ALONG THE ATLANTIC AND GULF COASTS IN WAKE OF COLD FRONT NOW MOVING S OF THE FL KEYS COMBINED WITH A COOL/STABLE AIR MASS ACROSS MUCH OF THE LOWER 48 STATES WILL PRECLUDE TSTM DEVELOPMENT THIS FORECAST PERIOD. OFFSHORE TSTM DEVELOPMENT...EAST OF VA/NC COAST...IS EXPECTED LATER THIS EVENING AND OVERNIGHT AS ASCENT/COOLER MID LEVEL TEMPERATURES ASSOCIATED WITH OH VALLEY SHORT WAVE TROUGH SPREAD EWD ATOP WARMER GULF WATERS. ..PETERS.. 01/28/2007  From swody1 at goshenarc.org Mon Jan 29 00:34:39 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 28 Jan 2007 19:34:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290039 SWODY1 SPC AC 290036 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0636 PM CST SUN JAN 28 2007 VALID 290100Z - 291200Z ...NO TSTM AREAS FORECAST... ...CA... 29/00Z OAK SOUNDING INDICATED THE PRESENCE OF STEEP LOW/MID LEVEL LAPSE RATES AND RESULTANT SBCAPES OF AROUND 500 J/KG. WATER VAPOR IMAGERY SUGGESTS THAT BETTER LARGE-SCALE FORCING ASSOCIATED WITH VORTICITY MAXIMUM ROTATING AROUND PARENT UPPER LOW IS CURRENTLY TRANSLATING WWD INTO THE PACIFIC. ONSET OF NOCTURNAL RADIATIONAL COOLING IS EXPECTED TO RESULT IN A DECREASE OF THESE LAPSE RATES IN THE LOW LEVELS...WHICH SHOULD LIMIT ANY ORGANIZED TSTM THREAT OVERNIGHT. ELSEWHERE...TSTMS ARE FORECAST TO BECOME INCREASINGLY NUMEROUS TONIGHT OFF THE MIDDLE ATLANTIC COAST AS STRONG SHORT WAVE TROUGH /CURRENTLY MOVING THROUGH THE APPALACHIANS/ ACTS ON UNSTABLE...PRE-FRONTAL AIR MASS. ..MEAD.. 01/29/2007  From swody1 at goshenarc.org Mon Jan 29 05:03:43 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 29 Jan 2007 00:03:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290508 SWODY1 SPC AC 290506 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 PM CST SUN JAN 28 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... AMPLIFIED LONG WAVE PATTERN WILL CONTINUE THROUGH THE DAY ONE PERIOD...CHARACTERIZED BY REX BLOCK OVER THE FAR ERN PACIFIC AND BROAD CYCLONIC FLOW GENERALLY E OF THE ROCKIES. LOW LATITUDE SHORT WAVE TROUGH /CURRENTLY NEAR 116W AND 21N/ IS FORECAST TO TRANSLATE ACROSS MEXICO INTO THE NWRN GULF OF MEXICO BY TUESDAY MORNING. IN THE LOW-LEVELS...SURFACE ANTICYCLONE INITIALLY OVER THE CNTRL GULF COAST WILL WEAKEN AS IT SHIFTS EWD. WEAK CYCLOGENESIS IS EXPECTED TO OCCUR OVER THE NWRN GULF COAST TONIGHT WITH APPROACH OF ABOVEMENTIONED SHORT WAVE TROUGH. INTENSIFYING SLY LLJ IN ADVANCE OF THIS SYSTEM WILL SUPPORT AN INCREASE IN LOW-LEVEL MOISTURE ACROSS THE WRN GULF BASIN WITH CONVECTION BECOMING INCREASINGLY LIKELY TONIGHT ALONG THE TX COAST INTO THE LOWER SABINE RIVER VALLEY. FORECAST SOUNDINGS INDICATE THAT CORRESPONDING THERMAL PROFILES WILL REMAIN RELATIVELY WARM WITH CONVECTION LIKELY TOO SHALLOW TO SUPPORT LIGHTNING. A GREATER THREAT OF EMBEDDED TSTMS WILL EXIST OFFSHORE WHERE INSTABILITY AND RESULTING UPDRAFT DEPTH WILL BE GREATER. ..MEAD.. 01/29/2007  From swody1 at goshenarc.org Wed Jan 31 00:28:57 2007 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 30 Jan 2007 19:28:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310033 SWODY1 SPC AC 310031 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 PM CST TUE JAN 30 2007 VALID 310100Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SRN CA COAST... MID AND UPPER LEVEL LOW OFF THE COAST IS FORECAST TO PIVOT MORE SEWD OVERNIGHT IN RESPONSE TO APPROACH OF UPSTREAM SYSTEM OVER NRN CA/NWRN NV. PROXIMITY OF ASSOCIATED MID-LEVEL COLD POOL WILL CONTINUE TO MAINTAIN MODERATELY STEEP LAPSE RATES AND RESULTANT WEAK CONVECTIVE INSTABILITY. THUS...THREAT OF ISOLATED THUNDER WILL LIKELY PERSIST THROUGH 31/12Z. ..MEAD.. 01/31/2007