From SWODY2 at goshenarc.org Wed Mar 1 05:59:43 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 01 Mar 2006 00:59:43 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060301060104.D4445D43D1@mail.goshen.edu> ACUS02 KWNS 010559 SWODY2 SPC AC 010558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST TUE FEB 28 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER FLOW REGIME ON THU WILL FEATURE TROUGHS ON BOTH COASTS AND A RIDGE IN THE CNTRL PORTIONS OF THE COUNTRY. THE SHORTWAVE TROUGH MOVING ACROSS THE NRN INTERMOUNTAIN WEST EARLY WED WILL AMPLIFY ALONG THE SRN PERIPHERY OF THE POLAR VORTEX...THEN DIG SEWD THROUGH THE GRTLKS AND OFF THE ERN SEABOARD BY MIDDAY THU. IN ITS WAKE...A COLD FRONT WILL SETTLE SWD INTO THE DEEP S AND THE SRN HIGH PLAINS. TO THE WEST...THE UPPER TROUGH AXIS ALONG THE PAC NW COAST WILL BE SLOW TO MOVE EWD AS THE NEXT IN A SERIES OF DISTURBANCES DROPS SWD INTO THE MEAN TROUGH POSITION. NUMEROUS SHORTWAVES EJECTING NEWD FROM THE ERN PAC WILL TRANSLATE NEWD INTO THE GRT BASIN AND NRN INTERMOUNTAIN WEST. ...SRN PLAINS/ROCKIES... COLD FRONT SHOULD SETTLE INTO CNTRL TX NWWD INTO CNTRL NM THROUGH MIDDAY THU. ELY UPSLOPE FLOW IN WAKE OF THIS FRONT WILL PROBABLY BE RESPONSIBLE FOR A FEW TSTMS EARLY IN THE PERIOD ACROSS NM. BUT...RIDGING ALOFT DOWNSTREAM FROM THE WEST COAST TROUGH MAY KEEP THE TSTM THREAT ISOLD. A PERSISTENT CAP AND RIDGING ALOFT ARE EXPECTED TO PREVENT SURFACE BASED TSTMS THROUGH THE DAY ALONG THE FRONT ACROSS CNTRL TX. BUT...AS THE SELY LLJ ACCELERATES LATER THU NIGHT...ELEVATED CONVECTION WILL LIKELY DEVELOP ANYWHERE FROM THE SRN TX PNHDL EWD INTO N TX OR SRN OK. ISOLD STRONGER STORMS MAY PRODUCE SMALL HAIL...BUT SEVERE WEATHER IS NOT ANTICIPATED. ...OH VLY/MID-ATLANTIC... ELEVATED CONVECTION WITH ONE OR TWO LIGHTNING STRIKES MAY BE ONGOING AT 12Z THU ALONG THE NOSE OF A STRONG LLJ ACROSS PORTIONS OF THE OH VLY/CNTRL APPALACHIANS. BUT...AS CYCLOGENESIS TAKES PLACE OFF DELMARVA...MASS CONVERGENCE QUICKLY SHIFTS OFF THE COAST AND TSTM PROBABILITIES SHOULD QUICKLY WANE WED MORNING. ...SACRAMENTO VLY CA... CYCLONIC FLOW ALOFT...STEEP LAPSE RATES AND RESIDUAL BOUNDARY LAYER MOISTURE MAY BE SUFFICIENT FOR SCT TSTMS ACROSS NRN/CNTRL CA THU AFTN. COOL PROFILES COULD SUPPORT SMALL HAIL IN THE STRONGER STORMS. ..RACY.. 03/01/2006  From SWODY2 at goshenarc.org Wed Mar 1 17:31:07 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 01 Mar 2006 12:31:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060301173235.94F2BD48C0@mail.goshen.edu> ACUS02 KWNS 011730 SWODY2 SPC AC 011729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CST WED MAR 01 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BASIC SYNOPTIC PATTERN WILL REMAIN CHARACTERIZED BY CYCLONE OVER CANADIAN MARITIMES...MEAN RIDGE OVER CENTRAL CONUS...AND PACIFIC TROUGH. STRONG SHORTWAVE TROUGH THAT IS NOW BREACHING MEAN RIDGE POSITION OVER NRN PLAINS WILL ACCELERATE ESEWD FROM UPPER MS VALLEY TO MID ATLANTIC REGION AND LOSE AMPLITUDE. HEIGHTS WILL BUILD AGAIN OVER CENTRAL CONUS BEHIND THIS FEATURE AND IN ADVANCE OF HIGH-AMPLITUDE PACIFIC TROUGH. VORTICITY MAX NOW LOCATED ABOUT 550 NM W OF CAPE MENDOCINO SHOULD MOVE INLAND CENTRAL/NRN CA COAST BETWEEN 2/12-2/18Z...BEFORE EJECTING NEWD AND LOSING AMPLITUDE OVER ERN ORE. FARTHER UPSTREAM...SPEED MAX NOW IS EVIDENT IN MOISTURE CHANNEL IMAGERY OVER PACIFIC...AROUND 140-145W AND W OF BC/WA/ORE COASTS. THIS FEATURE IS EXPECTED TO DIG SEWD THEN EWD AROUND BASE OF BROADER TROUGH...WITH STRONG SHORTWAVE TROUGH DEVELOPING AND MOVING ASHORE CA COAST AROUND END OF PERIOD. AT SFC...CYCLONE NOW OVER NERN KS/SERN NEB/NWRN MO AREA WILL MOVE EWD FROM OH VALLEY INTO N-CENTRAL APPALACHIANS...REDEVELOPING OFFSHORE MID-ATLANTIC COAST BY 3/00Z. TRAILING COLD FRONT SHOULD REACH FL PANHANDLE...MIDDLE TX COAST AND TX BIG BEND REGION BY END OF PERIOD...BECOMING STATIONARY OVER SW TX IN RESPONSE TO PRESSURE FALLS IN LEE OF ROCKIES. ...WRN CONUS... LOW-MIDDLE LEVEL FRONTAL ZONE -- NOW EVIDENT AS DEEP-LAYER CLOUD BAND JUST OFFSHORE WA/ORE COASTS WITH EMBEDDED AREAS OF CG LIGHTNING -- WILL MOVE INLAND AND DECELERATE ACROSS GREAT BASIN. THIS FEATURE SHOULD DENOTE ERN EDGE OF FORCING FAVORABLE FOR CONVECTION DURING DAY-2 PERIOD AS WELL. W OF BAROCLINIC ZONE...COMBINATION OF GRADUAL COOLING ALOFT ASSOCIATED WITH EWD MOVEMENT OF SYNOPTIC TROUGH TOWARD COAST -- AND MORE CONCENTRATED UVV ASSOCIATED WITH LANDFALLING SHORTWAVES -- WILL CONTRIBUTE TO INCREASING TSTM POTENTIAL INLAND. THIS DESTABILIZATION IS EVIDENT ATTM IN LARGE AREA OF GLACIATED CONVECTION THAT COVERS MUCH OF NERN PACIFIC E OF SPEED MAX. SMALL HAIL IS POSSIBLE WITH SOME TSTMS UNDER COLDEST MIDLEVEL AIR...AND STRONG GUSTS MAY ACCOMPANY SOME TSTMS IN FRONTAL ZONE THAT ARE EMBEDDED IN ENHANCED SWLY GRADIENT WINDS. HOWEVER SEVERE POTENTIAL APPEARS TOO ISOLATED...MARGINAL AND DISORGANIZED TO DELINEATE PROBABILITIES ATTM. ...MID/UPPER OH VALLEY... ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE DURING FIRST FEW HOURS OF PERIOD...BEFORE MIDLEVEL TROUGH FURTHER WEAKENS AND SFC CYCLONE SHIFTS OFFSHORE. STRONG ISENTROPIC ASCENT NE-SE OF SFC CYCLONE IS EXPECTED TO RAISE PARCELS TO LFC AMIDST MARGINAL LOW LEVEL MOISTURE...A CONTINUATION OF REGIME DISCUSSED IN DAY-1 OUTLOOK. ELEVATED MUCAPES SHOULD REMAIN WEAK -- GENERALLY UNDER 200 J/KG IN MOST AREAS...PRECLUDING SEVERE THREAT. ...SRN HIGH PLAINS...SRN ROCKIES... ISOLATED TSTMS ARE POSSIBLE EARLY-MIDMORNING HOURS OVER PORTIONS NERN NM AND/OR TX PANHANDLE...IN REGIME OF STRONG FRONTOGENETIC FORCING BUT MARGINAL MOISTURE. FCST SOUNDINGS INDICATE ENOUGH MIDLEVEL MOISTENING TO YIELD MUCAPES UP TO NEAR 200 J/KG...HIGHLY ELEVATED WITH BASES IN 550-650 MB LAYER. CAPPING AND DRY BOUNDARY LAYER THEN SHOULD PRECLUDE DIURNAL/SFC-BASED TSTMS. AFTER DARK...NWRN EDGE OF FAVORABLY MOISTENING RETURN FLOW AIR SHOULD BE ISENTROPICALLY LIFTED TO LFC ALONG ELEVATED FRONTAL ZONE...ACROSS PORTIONS N-CENTRAL THROUGH NWRN AND W-CENTRAL TX. CONVECTION IN THIS REGIME SHOULD BE DEEPER THAN ACTIVITY FROM PREVIOUS MORNING. FCST SOUNDINGS INDICATE MUCAPES TO AROUND 500-700 J/KG ROOTED NEAR 850 MB...AND POTENTIALLY 35-50 KT EFFECTIVE SHEAR. THOUGH SOME ISOLATED HAIL IS POSSIBLE...CONCERNS OVER MOISTURE AVAILABILITY PRECLUDE SEVERE PROBABILITIES ATTM. ..EDWARDS.. 03/01/2006  From SWODY2 at goshenarc.org Sat Mar 4 05:56:14 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Mar 2006 00:56:14 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060304055859.6D356D43D9@mail.goshen.edu> ACUS02 KWNS 040556 SWODY2 SPC AC 040555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 PM CST FRI MAR 03 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LOW-AMPLITUDE SHORT-WAVE TROUGH IS FORECAST TO EXTEND N-S ACROSS THE PLAINS STATES AT THE START OF THE PERIOD...SUPERIMPOSED UPON THE LARGE-SCALE MEAN RIDGE. THIS TROUGH WILL MOVE EWD WITH TIME -- LIKELY IN PIECEMEAL FASHION...WHILE RIDGE RE-AMPLIFIES ACROSS THE ERN ROCKIES/HIGH PLAINS IN ITS WAKE. MEANWHILE...A TROUGH WILL MOVE EWD ACROSS THE ERN PACIFIC...WITH CYCLONIC FLOW ALONG THE LEADING EDGE OF THIS FEATURE SPREADING ACROSS THE W COAST STATES AND EVENTUALLY INTO THE GREAT BASIN. AT THE SURFACE...WEAK FRONT/TROUGH WILL MOVE QUICKLY EWD FROM THE CENTRAL PLAINS ACROSS THE MID MS/LOWER OH/TN VALLEYS...WHILE SAGGING MORE SLOWLY SWD ACROSS OK/AR INTO NRN TX/NRN LA THROUGH THE END OF THE PERIOD. ...SERN KS/ERN OK/NERN TX EWD INTO TN/NRN MS/NRN AL... SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ACROSS NRN AND WRN PORTIONS OF THIS REGION...WITHIN WARM ADVECTION E OF SURFACE LOW/BOUNDARY. THOUGH MUCH OF THIS CONVECTION SHOULD DIURNALLY WEAKEN...NEW SHOWERS AND THUNDERSTORMS SHOULD DEVELOP WITHIN MARGINALLY-UNSTABLE AIRMASS NEAR FRONT...FROM WRN TN ACROSS AR AND PERHAPS INTO SERN OK/NERN TX. GREATEST INSTABILITY SHOULD EXIST ACROSS S CENTRAL OK/N TX...BUT EXPECT AIRMASS TO REMAIN GENERALLY CAPPED ACROSS THIS PORTION OF THE REGION. WITH WNWLY FLOW ABOVE THE BOUNDARY LAYER INCREASING TO NEAR 40 KT AT MID-LEVELS...SOME POTENTIAL FOR A FEW MORE ORGANIZED/SUSTAINED UPDRAFTS AND ASSOCIATED LOW-END SEVERE THREAT WOULD EXIST COULD STORMS DEVELOP WITHIN THIS MORE UNSTABLE AIRMASS. WILL NOT INTRODUCE SEVERE PROBABILITIES ATTM...BUT LOW PROBABILITIES MAY BE REQUIRED IN LATER UPDATES SHOULD IT BECOME MORE APPARENT THAT CAP MAY BE LOCALLY BREACHED. ..GOSS.. 03/04/2006  From SWODY2 at goshenarc.org Sat Mar 4 17:18:40 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Mar 2006 12:18:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060304172135.B5DDDD4634@mail.goshen.edu> ACUS02 KWNS 041719 SWODY2 SPC AC 041718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CST SAT MAR 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A PROMINENT SHORT WAVE TROUGH...NOW CENTERED OVER ID PER WATER VAPOR IMAGERY...IS EXPECTED TO TRACK SLOWLY EWD ACROSS THE DAKOTAS/SRN CANADA ON SUNDAY AS IT TOPS THE CENTRAL STATES RIDGE. THIS TROUGH IS THEN PROGGED TO TURN SEWD TOWARD THE WRN GREAT LAKES LATE DAY 2...AS THE RIDGE RE-AMPLIFIES IN ITS WAKE. THE SRN EXTENT OF THIS TROUGH COMBINED WITH WEAKER/LOW AMPLITUDE PACIFIC WAVES SHOULD TRANSLATE EWD ACROSS THE CENTRAL/SRN PLAINS TOWARD THE OH/TN RIVER VALLEYS AND DEEP SOUTH. IN THE LOW-LEVELS...A FRONT ASSOCIATED WITH THE NRN SYSTEM SHOULD MOVE QUICKLY EWD ACROSS THE MID MS AND OH/TN RIVER VALLEYS...REACHING OH INTO ERN KY/TN TO NRN MS BY 12Z MONDAY. THE SRN EXTENT OF THIS BOUNDARY WILL LIKELY MOVE AT A SLOWER PACE ACROSS OK/AR INTO NRN TX. MEANWHILE...A PACIFIC TROUGH /CURRENTLY LOCATED SEVERAL HUNDRED MILES OFF THE CA/ORE COASTS NEAR 140W/ IS EXPECTED TO MOVE INLAND OVER THE WRN STATES DURING THE SECOND HALF OF DAY 2. OFFSHORE THUNDERSTORM THREAT SHOULD INCREASE LATE SUNDAY AFTERNOON...AND THEN ALONG THE COASTAL REGIONS OF NRN CA TO WA AS A STEEPER LAPSE RATE ENVIRONMENT SPREADS INLAND WITH THE PACIFIC TROUGH. ...ERN OK/WRN AR/NERN TX/NWRN LA... SLY LOW-LEVEL FLOW...THOUGH VEERING WITH TIME AND LIMITING CONVERGENCE ALONG THE FRONT...IS EXPECTED TO MAINTAIN MOISTURE RETURN ACROSS THE ARKLATEX INTO LOWER/MID MS RIVER VALLEY. SURFACE DEWPOINTS IN THE UPPER 50S/LOWER 60S COMBINED WITH MODEST LAPSE RATES /6.5-7 C/KM/ AND SOME SURFACE HEATING SHOULD RESULT IN AN AXIS OF MODERATE INSTABILITY FROM NERN TX INTO PARTS OF ERN OK/WRN AR BY SUNDAY AFTERNOON. LATE DAY 1 THUNDERSTORMS SHOULD BE ONGOING AT THE START OF DAY 2 ACROSS SERN NEB/ERN KS AND POTENTIALLY ERN OK IN ASSOCIATION WITH WAA REGIME ALONG THE NOSE OF LLJ. THESE ELEVATED STORMS MAY WEAKEN SOME DURING THE MORNING AND/OR GRADUALLY INCREASE IN COVERAGE AGAIN ALONG THE NRN EXTENT OF MOISTURE RETURN AND WAA WITH THE VEERING LLJ ACROSS MO/PARTS OF AR INTO THE LOWER OH/TN RIVER VALLEYS. WEAK INSTABILITY IS PROGGED TO PRECLUDE A SEVERE THREAT WITH THIS ACTIVITY. DESPITE WEAKER LARGE SCALE FORCING FARTHER TO THE SW OVER THE ARKLATEX REGION...STRONGER AFOREMENTIONED INSTABILITY ACROSS THIS AREA AND STRONG DEEP LAYER SHEAR WOULD SUPPORT A POTENTIAL FOR ORGANIZED STORMS/SEVERE THREAT. MODELS SUGGEST SURFACE HEATING ALONG THE WRN/SRN PERIPHERY OF CLOUD SHIELD ASSOCIATED WITH ELEVATED CONVECTION MAY BECOME SUFFICIENT TO WEAKEN THE CAP FOR SURFACE BASED STORMS LATE SUNDAY AFTERNOON ACROSS WRN AR/ERN OK INTO NERN TX. GIVEN THIS TREND FOR THE DEVELOPMENT OF STRONGER INSTABILITY AND CONDITIONAL POTENTIAL FOR SURFACE BASED STORMS...LOW SEVERE PROBABILITIES WILL BE INTRODUCED WITH THIS OUTLOOK. HIGHER PROBABILITIES AND CATEGORICAL RISK MAY BE REQUIRED IN LATER OUTLOOKS...IF CONFIDENCE BECOMES GREATER FOR WIDESPREAD THREAT OF ORGANIZED STORMS/SEVERE THREAT. ..PETERS.. 03/04/2006  From SWODY2 at goshenarc.org Mon Mar 6 05:47:38 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 00:47:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306055239.A6998D4939@mail.goshen.edu> ACUS02 KWNS 060548 SWODY2 SPC AC 060547 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1147 PM CST SUN MAR 05 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE IS FORECAST TO SHIFT EWD FROM THE CENTRAL INTO THE ERN CONUS THIS PERIOD...AS WRN TROUGH -- COMPRISED OF SEVERAL SMALLER-SCALE FEATURES -- LIKEWISE PROGRESSES EWD. ONE PIECE OF THIS TROUGH WILL MOVE NEWD FROM CO/WY ACROSS THE CENTRAL AND NRN PLAINS INTO WRN ONTARIO/THE UPPER MS VALLEY. MEANWHILE...A SECOND SHORT-WAVE TROUGH -- INITIALLY ALONG THE W COAST -- WILL BECOME THE PREDOMINANT FEATURE AS IT MOVES EWD/SEWD WITH TIME. BY THE END OF THE PERIOD...THE AXIS OF THIS TROUGH SHOULD EXTEND FROM THE CANADIAN PRAIRIE SWD TO THE FOUR CORNERS REGION AND THE SSWWD ACROSS NRN BAJA CA. AT THE SURFACE...BROAD LOW PRESSURE INITIALLY OVER THE CENTRAL/NRN HIGH PLAINS WILL MOVE SEWD ACROSS THE CENTRAL PLAINS INTO KS/OK BY THE END OF THE PERIOD. THOUGH CONVECTION SHOULD BE WIDESPREAD ACROSS PORTIONS OF THE INTERIOR WEST...MORE VIGOROUS CONVECTION IS EXPECTED ACROSS THE MO VALLEY AND VICINITY WHERE GREATER INSTABILITY WILL EXIST. ...MID AND LOWER MO VALLEY/MID MS VALLEY... WARM SECTOR SHOULD REMAIN CAPPED THIS PERIOD ACROSS THE SRN PLAINS...DESPITE STEEP LAPSE RATES/MODERATE POTENTIAL INSTABILITY ABOVE CAPPING INVERSION. AS A RESULT...EXPECT THUNDERSTORM DEVELOPMENT THIS PERIOD TO BE CONFINED TO ZONE OF STRONG WARM ADVECTION/ISENTROPIC LIFT...WHICH SHOULD SHIFT EWD FROM THE CENTRAL PLAINS ACROSS THE MO/MS VALLEYS. ATTM...MODELS SUGGEST THAT 500 TO 1500 J/KG ELEVATED CAPE SHOULD EVOLVE WITH TIME ACROSS MUCH OF MO/IA/IL AND VICINITY...AIDED BY STRONG LOW-LEVEL JET AND ASSOCIATED THETA-E ADVECTION. WITH 50 TO 60 KT SWLY FLOW AT MID LEVELS ON SRN PERIPHERY OF SHORT-WAVE TROUGH CROSSING THE CENTRAL/NRN PLAINS...SHEAR/INSTABILITY COMBINATION APPEARS SUPPORTIVE OF A THREAT FOR AT LEAST MARGINALLY-SEVERE HAIL. THEREFORE...WILL INTRODUCE LOW SEVERE PROBABILITY ACROSS THIS REGION -- MAINLY FOR LATE AFTERNOON THROUGH THE OVERNIGHT HOURS. ..GOSS.. 03/06/2006  From SWODY2 at goshenarc.org Mon Mar 6 09:04:33 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 04:04:33 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306090711.D2260D4939@mail.goshen.edu> ACUS02 KWNS 060903 SWODY2 SPC AC 060902 DAY 2 CONVECTIVE OUTLOOK AMEND 1 NWS STORM PREDICTION CENTER NORMAN OK 0302 AM CST MON MAR 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... AMENDED TO ADD THUNDER/SEVERE PROBABILITY ACROSS OK/WRN N TX ...SYNOPSIS... UPPER RIDGE IS FORECAST TO SHIFT EWD FROM THE CENTRAL INTO THE ERN CONUS THIS PERIOD...AS WRN TROUGH -- COMPRISED OF SEVERAL SMALLER-SCALE FEATURES -- LIKEWISE PROGRESSES EWD. ONE PIECE OF THIS TROUGH WILL MOVE NEWD FROM CO/WY ACROSS THE CENTRAL AND NRN PLAINS INTO WRN ONTARIO/THE UPPER MS VALLEY. MEANWHILE...A SECOND SHORT-WAVE TROUGH -- INITIALLY ALONG THE W COAST -- WILL BECOME THE PREDOMINANT FEATURE AS IT MOVES EWD/SEWD WITH TIME. BY THE END OF THE PERIOD...THE AXIS OF THIS TROUGH SHOULD EXTEND FROM THE CANADIAN PRAIRIE SWD TO THE FOUR CORNERS REGION AND THE SSWWD ACROSS NRN BAJA CA. AT THE SURFACE...BROAD LOW PRESSURE INITIALLY OVER THE CENTRAL/NRN HIGH PLAINS WILL MOVE SEWD ACROSS THE CENTRAL PLAINS INTO KS/OK BY THE END OF THE PERIOD. THOUGH CONVECTION SHOULD BE WIDESPREAD ACROSS PORTIONS OF THE INTERIOR WEST...MORE VIGOROUS CONVECTION IS EXPECTED ACROSS PARTS OF THE S CENTRAL CONUS WHERE GREATER INSTABILITY WILL EXIST. ...CENTRAL AND WRN OK/WRN N TX... DRYLINE IS FORECAST TO MIX EWD ACROSS WRN OK/WRN N TX DURING THE AFTERNOON...INTO A MOIST/POTENTIALLY-UNSTABLE BUT CAPPED AIRMASS. HOWEVER...AS RIDGE OVER THE S CENTRAL CONUS SHIFTS EWD AND HEIGHTS FALL IN RESPONSE TO A WEAK SRN STREAM SHORT-WAVE FORECAST TO MOVE NEWD ACROSS THIS REGION...EXPECT ISOLATED STORMS TO DEVELOP ALONG DRYLINE WHERE CAP BECOMES LOCALLY BREACHED DURING THE LATE AFTERNOON. WITH VEERING/INCREASING FLOW WITH HEIGHT ANTICIPATED ACROSS THIS REGION...ANY STORMS WHICH DEVELOP WOULD BECOME SUPERCELLS. THEREFORE...WILL INTRODUCE 5% SEVERE THREAT ACROSS THIS REGION. ...MID AND LOWER MO VALLEY/MID MS VALLEY... EXPECT THUNDERSTORM DEVELOPMENT TO OCCUR THIS PERIOD WITHIN ZONE OF STRONG WARM ADVECTION/ISENTROPIC LIFT...WHICH SHOULD SHIFT EWD FROM THE CENTRAL PLAINS ACROSS THE MO/MS VALLEYS. ATTM...MODELS SUGGEST THAT 500 TO 1500 J/KG ELEVATED CAPE SHOULD EVOLVE WITH TIME ACROSS MUCH OF MO/IA/IL AND VICINITY...AIDED BY STRONG LOW-LEVEL JET AND ASSOCIATED THETA-E ADVECTION. WITH 50 TO 60 KT SWLY FLOW AT MID LEVELS ON SRN PERIPHERY OF SHORT-WAVE TROUGH CROSSING THE CENTRAL/NRN PLAINS...SHEAR/INSTABILITY COMBINATION APPEARS SUPPORTIVE OF A THREAT FOR AT LEAST MARGINALLY-SEVERE HAIL. THEREFORE...WILL INTRODUCE LOW SEVERE PROBABILITY ACROSS THIS REGION -- MAINLY FOR LATE AFTERNOON THROUGH THE OVERNIGHT HOURS. ..GOSS.. 03/06/2006  From SWODY2 at goshenarc.org Mon Mar 6 17:29:46 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 12:29:46 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306173225.C2A1FD4968@mail.goshen.edu> ACUS02 KWNS 061729 SWODY2 SPC AC 061728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST MON MAR 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN KS AND NRN/W CNTRL OK... ...CNTRL/SRN PLAINS AND MID-MS VLY... A SHORTWAVE TROUGH MOVING ONSHORE CNTRL CA ATTM IS EXPECTED TO TRANSLATE EWD ACROSS THE GRT BASIN TODAY...THEN REACH THE CNTRL/SRN PLAINS BY TUE AFTN. A LEE LOW OVER THE CNTRL HIGH PLAINS WILL DEVELOP EWD INTO CNTRL KS BY TUE AFTN WITH A DRYLINE SWD THROUGH SCNTRL KS...WRN OK AND WCNTRL TX. INCREASING SLY FLOW AHEAD OF THE MID-LEVEL TROUGH WILL ADVECT A NARROW RIBBON OF MSTR /SFC DEW POINTS AROUND 60 DEGREES F/ INTO PARTS OF CNTRL OK/KS JUST AHEAD OF THE DRYLINE BY TUE AFTN. MID-LEVEL THERMAL PROFILES WILL REMAIN COOL...AOB MINUS 15 DEGREES C. PRIND THAT WHILE THERE WILL BE CONSIDERABLE HIGH LEVEL SUB-TROPICAL CONVECTION ARCING ACROSS THE SRN PLAINS...SUFFICIENT CLEARING/INSOLATION WILL BE PRESENT BY MID-AFTN ACROSS WCNTRL OK NWD INTO CNTRL KS FOR MLCAPES OF 2000-2500 J/KG. AS TAIL END OF THE SHORTWAVE TROUGH BRUSHES ACROSS THE DRYLINE AND HEATING WEAKENS CINH...TSTM INITIATION SHOULD OCCUR FROM SCNTRL KS-WCNTRL OK BY LATE TUE AFTN. VERTICAL WIND PROFILES WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS AND VERY LARGE HAIL IS LIKELY GIVEN THE STEEP LAPSE RATES AND MAGNITUDE OF SHEAR. AN ISOLD TORNADO IS ALSO POSSIBLE. TSTMS SHOULD EVENTUALLY MOVE OFF THE DRYLINE AND PROBABLY WEAKEN OVER CNTRL OK. HOWEVER...INCREASING SLY LLJ OF 60-70 KTS WILL FAVOR A NOCTURNAL MCS OR TWO ACROSS THE OZARKS AND MID-MS VLY THROUGH EARLY WED. ISOLD TSTMS MAY PRODUCE LARGE HAIL. ..RACY.. 03/06/2006  From SWODY2 at goshenarc.org Tue Mar 7 07:57:32 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 02:57:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307080232.411ABD46C1@mail.goshen.edu> ACUS02 KWNS 070757 SWODY2 SPC AC 070755 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 AM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MO SWWD INTO CENTRAL TX... ...SYNOPSIS... GFS AND NAM CONTINUE TO DIFFER WITH THEIR HANDLING OF THE UPPER SYSTEM EJECTING OUT OF THE SWRN U.S./SRN ROCKIES INTO THE SRN PLAINS THIS PERIOD...AS WELL AS WITH THEIR POSITION OF THE DRYLINE. OVERALL HOWEVER...UPPER TROUGH WILL SHIFT EWD INTO THE SRN PLAINS THROUGH THE PERIOD. BROAD SURFACE LOW IS FORECAST OVER KS/OK BY LATE AFTERNOON...WITH A WARM FRONT EXTENDING ENEWD ACROSS ERN KS/NRN MO AND INTO IL...AND A DRYLINE EXTENDING SWD ACROSS OK/WRN N TX. AS UPPER TROUGH EJECTS...BOTH THE WARM FRONT AND THE DRYLINE SHOULD BECOME A FOCUS FOR SEVERE STORM DEVELOPMENT. ...SRN PLAINS NEWD INTO THE MID/LOWER MO VALLEY... SEASONABLY-MOIST BOUNDARY LAYER /DEWPOINTS IN THE UPPER 50S TO LOW 60S/ WILL CONTINUE TO ADVECT NWD ACROSS THE SRN AND CENTRAL PLAINS/OZARKS REGION AHEAD OF ADVANCING UPPER TROUGH AND ASSOCIATED SURFACE LOW. THOUGH ENEWD ADVECTION OF EML SHOULD RESULT IN A CAPPED BOUNDARY LAYER THROUGH MID AFTERNOON...DAYTIME HEATING AND INCREASING UVV AHEAD OF APPROACHING TROUGH SHOULD ALLOW STORMS TO DEVELOP BY LATE AFTERNOON FROM SRN KS SWD ACROSS WRN/CENTRAL OK INTO N TX AHEAD OF DRYLINE. STORMS SHOULD ALSO REDEVELOP/INCREASE INVOF WARM FRONT ACROSS ERN KS/MO BY AFTERNOON AS UPPER TROUGH APPROACHES. VERY STRONG DEEP-LAYER WIND FIELD ACCOMPANYING THIS FEATURE WILL RESULT IN SHEAR MORE THAN SUFFICIENT FOR SEVERE/SUPERCELL STORMS. EXPECT INITIAL CONVECTIVE DEVELOPMENT ALONG DRYLINE TO BE ISOLATED...WITH MORE WIDESPREAD STORMS LIKELY ALONG WARM FRONT ACROSS ERN KS/MO. ALONG WITH LARGE HAIL...LOCALLY DAMAGING WINDS AND AT LEAST A LOW-END TORNADO THREAT WILL ALSO EXIST. STORMS SHOULD INCREASE IN COVERAGE OVERNIGHT AS STRONG HEIGHT FALLS CONTINUE TO OVERSPREAD THE AREA. A MORE LINEAR STORM MODE SHOULD EVOLVE WITH TIME AHEAD OF DRYLINE WITH EMBEDDED SUPERCELLS -- RESULTING IN AN INCREASE IN DAMAGING WIND THREAT. SEVERE THREAT SHOULD PERSIST THROUGH THE NIGHT...EXTENDING FROM THE MIDDLE MS VALLEY SWWD INTO CENTRAL TX BY THE END OF THE PERIOD. ..GOSS.. 03/07/2006  From SWODY2 at goshenarc.org Tue Mar 7 17:38:02 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 12:38:02 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307174038.63624D4946@mail.goshen.edu> ACUS02 KWNS 071738 SWODY2 SPC AC 071737 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL/SRN PLAINS... ...CNTRL/SRN PLAINS... LONGWAVE TROUGH OVER THE WCOAST IS EXPECTED TO TRANSLATE TO THE PLAINS ON WED. SRN PART OF THE TROUGH WILL AMPLIFY WITH A STRONG IMPULSE DIGGING INTO THE DESERT SW WED MORNING AND THEN TURNING EWD INTO THE SRN PLAINS BY EARLY THU. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ALONG A BAROCLINIC ZONE FROM CNTRL KS EARLY WED INTO NRN MO BY WED AFTN. A TRIPLE POINT WILL DEVELOP OVER NWRN/NCNTRL OK DURING THE AFTN WED. THE DRYLINE WILL LIKELY MIX INTO CNTRL PORTIONS OF OK AND KS DURING THE LATE AFTN WHILE THE COLD FRONT ACROSS CNTRL KS MOVES SWD ACROSS OK THROUGH EARLY THU. ELEVATED TSTMS SHOULD BE ONGOING EARLY WED ACROSS THE OZARKS EWD INTO THE OH VLY...ALONG THE NOSE OF A WSWLY LLJ. THESE TSTMS WILL LIKELY SHIFT NWD INTO THE UPPER MIDWEST AND UPPER MS VLY THROUGH THE DAY AS A WARM FRONT TRANSLATES NWD...SIMILAR TO THE GFS SOLUTION. ISOLD HAIL MAY ACCOMPANY THESE TSTMS...PRIMARILY ACROSS THE OZARKS DURING THE MORNING. THE WARM SECTOR SHOULD EXPAND WED AFTN AS MID-UPPER 50S SFC DEW POINTS ADVECT NWD INTO CNTRL/ERN KS AND MO BENEATH STEEPENING MID-LEVEL LAPSE RATES. EML WILL BE STRONGEST ACROSS OK/TX AND SUGGESTS THE CAP MAY HOLD THROUGH MID-AFTN AT LEAST. CONVECTION SHOULD INCREASE FIRST ALONG THE TRIPLE POINT IN KS WHERE HEATING AND LOCAL CONVERGENCE ERASES CINH. STORMS SHOULD DEVELOP NEWD FROM SCNTRL KS ALONG THE SEWD MOVING COLD FRONT INTO WRN MO. FARTHER S...ISOLD TSTMS MAY FORM ALONG THE DRYLINE INTO WCNTRL OK DURING PEAK HEATING. BUT...STRONGER FORCING FOR ASCENT ASSOCIATED WITH THE APPROACHING WAVE SHOULD BE DELAYED UNTIL AFTER DARK. AT THAT TIME...TSTMS SHOULD BECOME MORE NUMEROUS ALONG/E OF THE DRYLINE AND ALONG/S OF THE COLD FRONT ACROSS OK...SERN KS AND SRN/WRN MO. VERTICAL SHEAR WILL BECOME INCREASINGLY SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL DURING WED AFTN. A FEW TORNADOES WILL BE POSSIBLE...PARTICULARLY ALONG THE TRACK OF THE TRIPLE POINT IN SERN KS OR CNTRL/ERN OK AND WITH CELLS THAT REMAIN DISCRETE THE LONGEST. THE LOW AND MID-LEVEL FLOW WILL GRADUALLY BACK WITH TIME DURING THE EVENING. THUS...WHILE DISCRETE CELLS WILL BE POSSIBLE WED AFTN...EVOLUTION INTO A MORE LINEAR MODE WITH EMBEDDED SUPERCELLS IS LIKELY WED NIGHT. ..RACY.. 03/07/2006  From SWODY2 at goshenarc.org Tue Mar 7 18:51:47 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 13:51:47 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307185443.037F1D4968@mail.goshen.edu> ACUS02 KWNS 071852 SWODY2 SPC AC 071851 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1251 PM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL/SRN PLAINS... CORRECTED FOR TRIPLE POINT POSITION ...CNTRL/SRN PLAINS... LONGWAVE TROUGH OVER THE WCOAST IS EXPECTED TO TRANSLATE TO THE PLAINS ON WED. SRN PART OF THE TROUGH WILL AMPLIFY WITH A STRONG IMPULSE DIGGING INTO THE DESERT SW WED MORNING AND THEN TURNING EWD INTO THE SRN PLAINS BY EARLY THU. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ALONG A BAROCLINIC ZONE FROM CNTRL KS EARLY WED INTO NRN MO BY WED AFTN. A TRIPLE POINT WILL DEVELOP OVER SCNTRL KS DURING THE AFTN WED WITH THE DRYLINE MIXING INTO CNTRL OK AND SERN KS BY EVENING. THE COLD FRONT ACROSS CNTRL KS SHOULD MOVE SWD INTO AND ACROSS OK THROUGH EARLY THU. ELEVATED TSTMS SHOULD BE ONGOING EARLY WED ACROSS THE OZARKS EWD INTO THE OH VLY...ALONG THE NOSE OF A WSWLY LLJ. THESE TSTMS WILL LIKELY SHIFT NWD INTO THE UPPER MIDWEST AND UPPER MS VLY THROUGH THE DAY AS A WARM FRONT TRANSLATES NWD...SIMILAR TO THE GFS SOLUTION. ISOLD HAIL MAY ACCOMPANY THESE TSTMS...PRIMARILY ACROSS THE OZARKS DURING THE MORNING. THE WARM SECTOR SHOULD EXPAND WED AFTN AS MID-UPPER 50S SFC DEW POINTS ADVECT NWD INTO CNTRL/ERN KS AND MO BENEATH STEEPENING MID-LEVEL LAPSE RATES. EML WILL BE STRONGEST ACROSS OK/TX AND SUGGESTS THE CAP MAY HOLD THROUGH MID-AFTN AT LEAST. CONVECTION SHOULD INCREASE FIRST ALONG THE TRIPLE POINT IN SCNTRL KS WHERE HEATING AND LOCAL CONVERGENCE ERASES CINH. STORMS SHOULD DEVELOP NEWD FROM SCNTRL KS ALONG THE SEWD MOVING COLD FRONT INTO WRN MO. FARTHER S...ISOLD TSTMS MAY FORM ALONG THE DRYLINE INTO CNTRL OK DURING PEAK HEATING. BUT...STRONGER FORCING FOR ASCENT ASSOCIATED WITH THE APPROACHING WAVE SHOULD BE DELAYED UNTIL AFTER DARK. AT THAT TIME...TSTMS SHOULD BECOME MORE NUMEROUS ALONG/E OF THE DRYLINE AND ALONG/S OF THE COLD FRONT ACROSS OK...SERN KS AND SRN/WRN MO. VERTICAL SHEAR WILL BECOME INCREASINGLY SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL DURING WED AFTN. A FEW TORNADOES WILL BE POSSIBLE...PARTICULARLY ALONG THE TRACK OF THE TRIPLE POINT IN SERN KS OR CNTRL/ERN OK AND WITH CELLS THAT REMAIN DISCRETE THE LONGEST. THE LOW AND MID-LEVEL FLOW WILL GRADUALLY BACK WITH TIME DURING THE EVENING. THUS...WHILE DISCRETE CELLS WILL BE POSSIBLE WED AFTN...EVOLUTION INTO A MORE LINEAR MODE WITH EMBEDDED SUPERCELLS IS LIKELY WED NIGHT. ..RACY.. 03/07/2006  From SWODY2 at goshenarc.org Wed Mar 8 07:08:58 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Mar 2006 02:08:58 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060308071151.DE38BD45E5@mail.goshen.edu> ACUS02 KWNS 080709 SWODY2 SPC AC 080708 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CST WED MAR 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER AND MID MS/TN/OH VALLEYS AND EWD INTO THE SERN CONUS... ...SYNOPSIS... STRONG SHORT-WAVE TROUGH MOVING ACROSS TX/OK AT THE START OF THE PERIOD IS FORECAST TO SHIFT CYCLONICALLY EWD/NEWD ACROSS THE MS/TN/OH VALLEYS THROUGH THE PERIOD. THIS FEATURE WILL BE ACCOMPANIED BY VERY STRONG FLOW -- INCLUDING 60 TO 80 KT SLY/SSWLY LOW-LEVEL JET AND 80 TO 100 KT SSWLY FLOW AT MID LEVELS. AS THIS FEATURE SHIFTS EWD/NEWD...LOW PRESSURE IS FORECAST TO CONSOLIDATE INVOF THE MID MS VALLEY AND THEN MOVE NEWD AND APPROACH SRN ONTARIO THROUGH THE END OF THE PERIOD. ASSOCIATED PRE-FRONTAL TROUGH SHOULD MOVE EWD ACROSS THE MS VALLEY DURING THE AFTERNOON...LIKELY ACTING AS A FOCUS FOR SEVERE STORMS. ...MID AND LOWER MS/OH/TN VALLEYS SWD TO THE CENTRAL GULF COAST... STRONG/SEVERE STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS AR AND VICINITY...AHEAD OF UPPER TROUGH. COMBINATION OF SEASONABLY MOIST BOUNDARY LAYER ADVECTING NWD TOWARD THE OH VALLEY AND SOME DAYTIME HEATING...MODERATE DESTABILIZATION /1000 TO 1500 J/KG MEAN-LAYER CAPE/ IS EXPECTED BY AFTERNOON. AS UPPER TROUGH TAKES ON AN INCREASINGLY NEGATIVE TILT WITH TIME AND SURFACE CONVERGENCE AXIS SHIFTS EWD...STORMS SHOULD INCREASE/DEVELOP SWD FROM THE MID MS VALLEY TOWARD THE GULF COAST...LIKELY EVOLVING INTO A SQUALL LINE BY AFTERNOON. ATTM...MOST SIGNIFICANT SEVERE THREAT APPEARS TO BE DAMAGING WINDS...GIVEN VERY STRONG/COMPACT UPPER FEATURE AND CORRESPONDING STRENGTH OF FAIRLY UNIDIRECTIONAL SSWLY DEEP-LAYER WIND FIELD. HAIL AND POSSIBLY A COUPLE TORNADOES WILL ALSO BE POSSIBLE...WITH SHEAR VERY SUPPORTIVE OF SUPERCELLS. SEVERE THREAT IS EXPECTED TO SHIFT EWD ACROSS THE GULF COAST/NEWD ACROSS THE TN AND OH VALLEYS THROUGH THE AFTERNOON/EVENING. HOWEVER...THREAT SHOULD TAPER OFF SOMEWHAT OVERNIGHT...AS DECREASING INSTABILITY ACROSS THE UPPER OH VALLEY...AND DECREASING UVV/CONVERGENCE ACROSS THE SOUTHEAST LEADS TO AN OVERALL DECREASE IN STORM INTENSITY THROUGH THE END OF THE PERIOD. ..GOSS.. 03/08/2006  From SWODY2 at goshenarc.org Wed Mar 8 17:31:00 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Mar 2006 12:31:00 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060308173338.50445D46C1@mail.goshen.edu> ACUS02 KWNS 081731 SWODY2 SPC AC 081730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST WED MAR 08 2006 VALID 091200Z - 101200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER TO MID MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...OZARKS...OH VALLEY AND TN VALLEY... ...MS VALLEY... AN IMPRESSIVE UPPER-LEVEL TROUGH OVER THE DESERT SW WILL EJECT EWD TONIGHT DEEPENING AND BECOMING NEGATIVELY TILTED OVER THE SRN PLAINS THURSDAY. AHEAD OF THIS POTENT UPPER-TROUGH LARGE-SCALE ASCENT WILL BECOME INCREASINGLY FOCUSED AS A 100 KT MID-LEVEL JET PUNCHES INTO THE LOWER MS VALLEY. RICH LOW-LEVEL MOISTURE AHEAD OF THE SYSTEM COMBINED WITH VERY STRONG WIND SHEAR PROFILES SUGGEST THE POTENTIAL FOR A MAJOR SEVERE WEATHER OUTBREAK EXISTS FOR THURSDAY AND THURSDAY NIGHT ACROSS THE LOWER TO MID MS VALLEY. A LARGE COMPLEX OF THUNDERSTORMS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD AS THE TROUGH SWINGS EWD INTO THE SRN PLAINS. AT 12Z MODEL CONSENSUS PLACES A SQUALL-LINE OR BROKEN LINE OF STORMS ALONG THE WEST EDGE OF A WELL-DEVELOPED LOW-LEVEL JET WITH THE LINE EXTENDING SWWD FROM THE LOWER OH VALLEY ACROSS THE OZARKS INTO THE SRN PLAINS. AHEAD OF THE UPPER-LEVEL TROUGH THE STRONG LOW-LEVEL FLOW SHOULD TRANSPORT SFC DEWPOINTS IN THE 60S F AS FAR NORTH AS SRN IL DURING THE DAY. THIS COMBINED WITH THE PROGRESSIVE AND VERY WELL-DEVELOPED NATURE OF THE UPPER-TROUGH SUGGESTS THAT INSTABILITY WILL BE SUFFICIENT FOR SEVERE STORMS. IN ADDITION...THE 15Z TO 18Z FORECAST SOUNDINGS ACROSS THE REGION ON THURSDAY SHOW IMPRESSIVE SHEAR PROFILES WITH STRONG LOW TO MID-LEVEL VEERING AND SUFFICIENT SPEED SHEAR FOR SUPERCELLS WITH WELL-DEVELOP LOW-LEVEL MESOCYCLONES. ALTHOUGH NOT YET CERTAIN...A TORNADO OUTBREAK WILL BE POSSIBLE ESPECIALLY IF A LARGE NUMBER OF STORMS REMAIN DISCRETE AS THE INITIAL LARGE CLUSTER OF STORMS DRIFTS EWD AND EXPANDS FROM NORTH TO SOUTH ACROSS THE MS VALLEY DURING THE AFTERNOON. THE BEST POTENTIAL FOR LONG TRACK STRONG OR VIOLENT TORNADOES SHOULD BE WHERE INSTABILITY IS LOCALLY MAXIMIZED AND JUST AHEAD OF THE SFC LOW AND IN THE NOSE OF THE MID-LEVEL JET. IF THE MAJORITY OF THE STORMS REMAIN LINEAR INSTEAD OF DISCRETE...A WIDESPREAD WIND DAMAGE EVENT WOULD BE MORE LIKELY AS A SQUALL-LINE MOVES EWD ACROSS THE REGION. WIND GUSTS ABOVE 70 KTS AND LARGE HAIL ABOVE 2 INCHES WOULD BE POSSIBLE WITH THE SUPERCELLS AND BOW ECHOES EMBEDDED IN OR AHEAD OF THE LINE. THE HEAVIEST CONCENTRATION OF SEVERE WEATHER EVENTS SHOULD BE ALONG THE MOIST AXIS ACROSS AR...LA...MS AND WRN TN ALTHOUGH SOME SEVERE WEATHER WILL BE POSSIBLE AS FAR NORTH AS THE OH VALLEY AND SRN LOWER MI DUE TO THE STRONG MID-LEVEL FLOW AS THE LEFT EXIT REGION OF THE MID-LEVEL JET PASSES ACROSS THE REGION THURSDAY NIGHT. DURING THE NIGHT...A SOLID LINE SHOULD DRIFT EWD ACROSS THE OH AND TN VALLEYS WITH THE SEVERE WEATHER THREAT GRADUALLY DECREASING. ...WEST COAST... MODEL FORECASTS DEVELOP AN UPPER-LEVEL TROUGH ALONG THE WEST COAST THURSDAY SPREADING STRONG LARGE-SCALE ASCENT INTO WA...ORE AND CA THURSDAY NIGHT. AS THIS OCCURS...STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH THE TROUGH MAY BE ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT ALONG THE IMMEDIATE COASTAL AREAS. HOWEVER...INSTABILITY AND SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH FOR AN OUTLOOK AREA OF SEVERE WEATHER THURSDAY NIGHT. ..BROYLES.. 03/08/2006  From SWODY2 at goshenarc.org Thu Mar 9 06:59:44 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 01:59:44 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309070211.805AAD42E0@mail.goshen.edu> ACUS02 KWNS 090659 SWODY2 SPC AC 090658 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL PREVAIL ACROSS THE CONUS THIS PERIOD. HOWEVER...A SERIES OF SHORT-WAVE TROUGHS -- ONE MOVING QUICKLY NEWD ACROSS THE NERN CONUS AND THE OTHER MOVING OUT OF THE ROCKIES INTO THE CENTRAL/NRN PLAINS LATE -- WILL ALSO BE ASSOCIATED WITH CONVECTIVE WEATHER THIS PERIOD. A STRONG COLD FRONT -- CORRELATED WITH THE NERN U.S. SHORT-WAVE TROUGH -- IS FORECAST TO MOVE EWD ACROSS NEW ENGLAND/THE MID ATLANTIC REGION. FURTHER W...A DEEPENING SURFACE LOW SHOULD MOVE OUT OF THE CENTRAL HIGH PLAINS AND NEWD ACROSS NEB THROUGH THE PERIOD IN CONJUNCTION WITH THE UPPER FEATURE MOVING OUT OF THE ROCKIES. THOUGH SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS BOTH OF THESE AREAS...IT APPEARS ATTM THAT SEVERE THREAT SHOULD REMAIN LIMITED. ...FAR SRN NEW ENGLAND SWD INTO ERN NC... THOUGH STRONGEST FORCING ALOFT AND SHARPEST PORTION OF COLD FRONT SHOULD MOVE NEWD ACROSS NEW ENGLAND...ONLY MINIMAL ELEVATED INSTABILITY IS FORECAST AT BEST. THOUGH GREATEST INSTABILITY IS EXPECTED FURTHER S INTO SC/GA/SRN AL...WEAKER WIND FIELD AND PERSISTENT SURFACE RIDGE SUGGESTS ONLY ISOLATED THUNDERSTORMS AND LITTLE IF ANY SEVERE THREAT ACROSS THIS PORTION OF THE AREA. BETWEEN THE AREA OF STRONGER INSTABILITY OVER THE SOUTHEAST AND STRONGER UVV OVER NEW ENGLAND...A CORRIDOR OF MARGINAL DESTABILIZATION MAY OCCUR AHEAD OF COLD FRONT FROM EXTREME SRN NEW ENGLAND SWD INTO SRN VA/ERN NC. THOUGH STORMS SHOULD REMAIN ISOLATED -- PARTICULARLY WITH SWD EXTENT...DEEP-LAYER WIND FIELD WILL REMAIN MORE THAN SUPPORTIVE OF SEVERE/SUPERCELL STORMS. ATTM...WILL MAINTAIN 5% SEVERE PROBABILITY...WITH GENERALLY WEAK LOW-LEVEL FORCING AND MARGINAL INSTABILITY EXPECTED ATTM BEING THE MAIN LIMITING FACTORS. SHOULD SOMEWHAT GREATER AIRMASS DESTABILIZATION OCCUR INTO NJ/THE DELMARVA REGION...SLIGHT RISK AREA MAY BE REQUIRED IN LATER FORECASTS. ...PORTIONS OF THE CENTRAL/NRN PLAINS INTO THE UPPER MS VALLEY... ELEVATED THUNDERSTORMS SHOULD DEVELOP BY LATE AFTERNOON/EVENING WITHIN ZONE OF WARM ADVECTION NE OF SURFACE LOW/AHEAD OF APPROACHING SHORT-WAVE TROUGH. INSTABILITY SHOULD REMAIN MARGINAL...AND THUS EXPECT ANY HAIL TO REMAIN BELOW SEVERE THRESHOLDS DESPITE FAVORABLY-STRONG FLOW ALOFT. ...THE WEST... SHOWERS ARE FORECAST ACROSS MUCH OF THE WEST THIS PERIOD -- ALONG WITH A FEW THUNDERSTORMS OVER PARTS OF THE AREA -- AS LARGE UPPER TROUGH RESIDES OVER THIS REGION. MINIMAL INSTABILITY SHOULD PRECLUDE ANY APPRECIABLE SEVERE THREAT...THOUGH A STRONGER/MARGINALLY-SEVERE CELL MAY AFFECT COASTAL SRN CA LATE IN THE PERIOD AS MID-LEVEL JET STREAK NOSES SEWD INTO THIS AREA. ..GOSS.. 03/09/2006  From SWODY2 at goshenarc.org Thu Mar 9 17:25:52 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 12:25:52 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309172944.D9631D46B5@mail.goshen.edu> ACUS02 KWNS 091724 SWODY2 SPC AC 091723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1123 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE CONUS IS CURRENTLY UNDER THE INFLUENCE OF A LARGE LONG WAVE TROUGH. A JET MAX OF 130KTS IS FORCING A COLD FRONT INTO THE EASTERN US WHILE ANOTHER JET MAX OF 120KTS IS ENTERING THE WEST COAST NEAR CENTRAL CA. THE JET MAX OVER THE EASTERN US WILL WEAKEN AND QUICKLY MOVE TOWARDS THE NE DURING THIS PERIOD. MEANWHILE...THE JET MAX OVER THE WEST WILL CONTINUE TO DIVE SOUTH INTO THE SW US CAUSING LOW PRESSURE TO FORM AND DEEPEN AS IT MOVES INTO THE PLAINS BY THE END OF THE PERIOD. ...EASTERN US... THE COLD FRONT OVER THE EASTERN US WEAKENS AS THE JET MAX RIDES UP THE LONG WAVE RIDGE OVER THE EAST COAST. AS THE FRONT ENTERS THE REGION IT WILL ENCOUNTER INCREASINGLY STABLE AIR. WEAK INSTABILITY AND STRONG FORCING AT 850MB WILL CAUSE ISOLATED CONVECTION ALONG THE FRONT. FORCING WILL BE STRONG AS A LLJ OF UP TO 70KTS MOVES OVER NJ. AN ISOLATED SEVERE WIND GUST IS POSSIBLE AT THE BEGINNING OF THE PERIOD IN THIS AREA. THE GREATEST INSTABILITY WILL BE IN THE SE US WHERE THERE IS A LACK OF A LIFTING MECHANISM. ISOLATED THUNDERSTORMS BELOW SEVERE LEVELS CAN BE EXPECTED IN THIS AREA. ...PORTIONS OF THE CENTRAL PLAINS... A WARM FRONT WILL MOVE OUT INTO THE PLAINS AHEAD OF THE LOW PRESSURE MOVING OUT OF THE WESTERN US. WEAK INSTABILITY AND WEAK FORCING OVER THE WARM FRONT WILL PROVIDE EARLY MORNING THUNDERSTORMS ALONG AND AHEAD OF THE WARM FRONT AS IT MOVES TOWARDS WI. ...WESTERN US... ISOLATED CONVECTION WILL OCCUR OVER SOME OF THE HIGHER TERRAIN IN THE WEST. A COLD POCKET AT 500MB WITH TEMPERATURES BELOW-30C ALONG WITH WEAK MECHANICAL LIFTING WILL SUPPORT WEAK THUNDERSTORMS/THUNDERSNOW DURING THE PERIOD. ..AFWA.. 03/09/2006  From SWODY2 at goshenarc.org Thu Mar 9 17:49:10 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 12:49:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309175132.AB0F9D46B5@mail.goshen.edu> ACUS02 KWNS 091749 SWODY2 SPC AC 091723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1123 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE CONUS IS CURRENTLY UNDER THE INFLUENCE OF A LARGE LONG WAVE TROUGH. A JET MAX OF 130KTS IS FORCING A COLD FRONT INTO THE EASTERN US WHILE ANOTHER JET MAX OF 120KTS IS ENTERING THE WEST COAST NEAR CENTRAL CA. THE JET MAX OVER THE EASTERN US WILL WEAKEN AND QUICKLY MOVE TOWARDS THE NE DURING THIS PERIOD. MEANWHILE...THE JET MAX OVER THE WEST WILL CONTINUE TO DIVE SOUTH INTO THE SW US CAUSING LOW PRESSURE TO FORM AND DEEPEN AS IT MOVES INTO THE PLAINS BY THE END OF THE PERIOD. ...EASTERN US... THE COLD FRONT OVER THE EASTERN US WEAKENS AS THE JET MAX RIDES UP THE LONG WAVE RIDGE OVER THE EAST COAST. AS THE FRONT ENTERS THE REGION IT WILL ENCOUNTER INCREASINGLY STABLE AIR. WEAK INSTABILITY AND STRONG FORCING AT 850MB WILL CAUSE ISOLATED CONVECTION ALONG THE FRONT. FORCING WILL BE STRONG AS A LLJ OF UP TO 70KTS MOVES OVER NJ. AN ISOLATED SEVERE WIND GUST IS POSSIBLE AT THE BEGINNING OF THE PERIOD IN THIS AREA. THE GREATEST INSTABILITY WILL BE IN THE SE US WHERE THERE IS A LACK OF A LIFTING MECHANISM. ISOLATED THUNDERSTORMS BELOW SEVERE LEVELS CAN BE EXPECTED IN THIS AREA. ...PORTIONS OF THE CENTRAL PLAINS... A WARM FRONT WILL MOVE OUT INTO THE PLAINS AHEAD OF THE LOW PRESSURE MOVING OUT OF THE WESTERN US. WEAK INSTABILITY AND WEAK FORCING OVER THE WARM FRONT WILL PROVIDE EARLY MORNING THUNDERSTORMS ALONG AND AHEAD OF THE WARM FRONT AS IT MOVES TOWARDS WI. ...WESTERN US... ISOLATED CONVECTION WILL OCCUR OVER SOME OF THE HIGHER TERRAIN IN THE WEST. A COLD POCKET AT 500MB WITH TEMPERATURES BELOW-30C ALONG WITH WEAK MECHANICAL LIFTING WILL SUPPORT WEAK THUNDERSTORMS/THUNDERSNOW DURING THE PERIOD. ..AFWA.. 03/09/2006  From SWODY2 at goshenarc.org Fri Mar 10 17:27:16 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 12:27:16 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310172940.5CF7BD46A3@mail.goshen.edu> ACUS02 KWNS 101726 SWODY2 SPC AC 101726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY AND SRN PLAINS... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Fri Mar 10 20:13:34 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 15:13:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310201550.01A82D4735@mail.goshen.edu> ACUS02 KWNS 102013 SWODY2 SPC AC 102012 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0212 PM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY AND SRN PLAINS... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Fri Mar 10 20:25:12 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 15:25:12 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310202738.56771D4565@mail.goshen.edu> ACUS02 KWNS 102024 SWODY2 SPC AC 102023 DAY 2 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0223 PM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND MS VALLEY... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Sat Mar 11 06:08:37 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 01:08:37 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311061051.91BC2D4735@mail.goshen.edu> ACUS02 KWNS 110608 SWODY2 SPC AC 110607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1207 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS SUN AFT/EVE ACROSS MUCH OF THE MIDDLE MISSISSIPPI VALLEY...FOR A POSSIBLE OUTBREAK OF SEVERE STORMS...INCLUDING SUPERCELLS WITH POTENTIAL FOR ISOLATED STRONG TORNADOES.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA...FROM EASTERN PORTIONS OF THE CNTRL/SRN PLAINS THRU THE OHIO VALLEY.... SEVERAL SIGNIFICANT SHORT WAVE IMPULSES CONTINUE TO PROGRESS THROUGH A BROAD/DEEP COLD UPPER TROUGH...WHICH NOW ENCOMPASSES MUCH OF THE WESTERN AND CENTRAL STATES. STRONGEST OF THESE IMPULSES/JET STREAKS NOW APPEARS TO BE DIGGING INTO BASE OF UPPER TROUGH NEAR THE SOUTHERN CALIFORNIA COAST...AND IS STILL PROGGED BY MOST MODEL GUIDANCE TO NOSE INTO THE SOUTHERN ROCKIES BY 12Z SUNDAY. MODELS SUGGEST THIS FEATURE WILL CONTINUE TO LIFT OUT...ACROSS THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY...SUNDAY/SUNDAY NIGHT. THIS IS PROGGED TO OCCUR IN PHASE WITH A STRONG SUBTROPICAL JET STREAK...WHICH IS EXPECTED TO NOSE ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY...AND BULK OF UPPER TROUGH IS FORECAST TO BEGIN LIFTING OUT OF THE WESTERN STATES. VARIABILITY STILL EXISTS AMONG SOME MODELS CONCERNING THE STRENGTH OF SURFACE CYCLOGENESIS TO OCCUR IN THE LEE OF THE CENTRAL ROCKIES. HOWEVER...WHILE MOST SUBSTANTIAL DEEPENING MAY NOT OCCUR UNTIL MONDAY ACROSS THE EASTERN CANADIAN PROVINCES...IT NOW APPEARS MOST LIKELY THAT A SUB 1000 MB SURFACE LOW WILL DEVELOP BY EARLY SUNDAY ACROSS THE CENTRAL HIGH PLAINS...BEFORE TRACKING NORTHEASTWARD INTO THE GREAT LAKES REGION BY 12Z MONDAY. REGARDLESS...WITH 70F+ DEW POINTS NOW PRESENT ACROSS MUCH OF THE GULF OF MEXICO...AND A SIGNIFICANT RETURN FLOW ALREADY UNDERWAY INTO THE SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY...A BROAD VERY MOIST AND POTENTIALLY MODERATELY UNSTABLE WARM SECTOR IS EXPECTED ACROSS THE CENTRAL STATES BY SUNDAY AFTERNOON. AS FLOW FIELDS STRENGTHEN AND VERTICAL SHEAR PROFILES INCREASE WITHIN THIS WARM SECTOR...THE ENVIRONMENT IS EXPECTED TO BECOME SUPPORTIVE OF AN OUTBREAK OF SEVERE STORMS WITH LARGE HAIL/WIND DAMAGE AND TORNADOES. RISK AREA WILL INCLUDE METROPOLITAN KANSAS CITY/ST. LOUIS AND LITTLE ROCK LATE SUNDAY AFTERNOON...EXTENDING EASTWARD INTO INDIANAPOLIS/MEMPHIS SUNDAY EVENING...POSSIBLY THE LOUISVILLE/CINCINNATI AND CLEVELAND AREAS SUNDAY NIGHT. ...EAST CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY... WHILE CONSIDERABLE CONVECTION ASSOCIATED WITH A LEAD SHORT WAVE IMPULSE MAY BE ONGOING AT 12Z SUNDAY ACROSS THE LOWER OHIO VALLEY ...MUCH OF THE EAST CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY IS EXPECTED TO BE RELATIVE FREE OF CONVECTION/PRECIPITATION. WITH INSOLATION...STEEP MID-LEVEL LAPSE RATES ON NOSE OF RETURNING ELEVATED MIXED LAYER...AND SURFACE DEW POINTS IN THE 60S...SHOULD CONTRIBUTE TO MIXED LAYER CAPE ON THE ORDER OF 2000 J/KG IN SURFACE WARM SECTOR. THIS WILL EXIST EAST OF DRY LINE...LIKELY TO TRAIL SOUTH OF SURFACE LOW CENTER ACROSS NORTHEAST KANSAS BY LATE AFTERNOON...AND SOUTH OF WARM FRONT...LIKELY TO EXTEND EAST OF LOW INTO THE LOWER GREAT LAKES REGION. THOUGH DETAILS OF SURFACE FEATURES ARE STILL UNCERTAIN...CAPPING WITHIN WARM SECTOR SEEMS LIKELY TO BE WEAK ENOUGH FOR SCATTERED CONVECTIVE DEVELOPMENT IN RESPONSE TO FORCING ASSOCIATED WITH PEAK HEATING/BROAD LOW-LEVEL WARM ADVECTION AND DIFLUENT UPPER FLOW REGIME. SUPERCELLS COULD BECOME FAIRLY NUMEROUS BY LATE SUNDAY AFTERNOON...PARTICULARLY FROM PARTS OF EASTERN KANSAS THROUGH MISSOURI AND MUCH OF ARKANSAS. 30 TO 50 KT SOUTHERLY LOW-LEVEL JET ACROSS THIS REGION WILL CONTRIBUTE TO LARGE LOW-LEVEL HODOGRAPHS BENEATH STRONG WEST SOUTHWESTERLY UPPER FLOW. A FEW TORNADOES APPEAR LIKELY...SOME OF WHICH COULD BECOME STRONG. OTHERWISE...LARGE HAIL/DAMAGING WIND GUSTS WILL ALSO ACCOMPANY STRONGER STORMS...WHICH SHOULD DEVELOP INTO ILLINOIS EARLY SUNDAY EVENING. ...OHIO VALLEY... INTENSIFYING SOUTHERLY LOW-LEVEL JET AND FORCING ASSOCIATED WITH PRIMARY UPPER IMPULSE...EAST SOUTHEAST OF SURFACE LOW...ARE EXPECTED TO SUPPORT ORGANIZING SQUALL LINE SUNDAY EVENING ACROSS PARTS OF THE SOUTHERN GREAT LAKES REGION AND LOWER OHIO VALLEY. ACTIVITY WILL CONTINUE EASTWARD THROUGH MUCH OF THE REMAINDER OF THE OHIO VALLEY SUNDAY NIGHT/EARLY MONDAY...WITHIN 50+ KT MEAN FLOW REGIME. THIS WILL SUPPORT CONTINUING SEVERE POTENTIAL... PRIMARILY IN THE FORM OF DAMAGING WINDS. ..KERR.. 03/11/2006  From SWODY2 at goshenarc.org Sat Mar 11 17:24:42 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 12:24:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311172657.4F8BBD4C12@mail.goshen.edu> ACUS02 KWNS 111725 SWODY2 SPC AC 111724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF TX...OK...LA...AR...MS...TN...MO...IA...IL...KY AND TN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS...LOWER MS VALLEY...TN VALLEY...UPPER OH VALLEY AND UPPER MIDWEST... ...MS VALLEY/SRN PLAINS... A BROAD UPPER-LEVEL TROUGH WILL CONTINUE IN PLACE ACROSS THE WRN U.S. WITH SOUTHWEST FLOW PRESENT ACROSS THE GREAT PLAINS AND MS VALLEY TONIGHT INTO SUNDAY. A 100 KT MID-LEVEL JET IS FORECAST TO MOVE INTO THE PLAINS STATES SUNDAY AND SUNDAY NIGHT. SHORTWAVE ACTIVITY EMBEDDED IN THE BROAD SOUTHWEST FLOW REGIME WILL CAUSE LARGE-SCALE ASCENT TO INCREASE ACROSS THE REGION BY AFTERNOON. THIS COMBINED WITH A BROAD WARM SECTOR WILL PROVIDE THE INGREDIENTS NECESSARY FOR A WIDESPREAD SEVERE WEATHER THREAT SUNDAY AND SUNDAY NIGHT. MODEL FORECASTS ARE RELATIVELY CONSISTENT...INITIATING WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE WRN EDGE OF THE LOW-LEVEL MOISTURE GRADIENT SUNDAY AFTERNOON. INITIATION WOULD MOST LIKELY OCCUR WHERE SFC HEATING IS MAXIMIZED WITH SEVERAL STORM CLUSTERS DEVELOPING NEAR A SFC LOW ACROSS NRN MO EXTENDING SSWWD ACROSS WRN...ERN OK AND NE TX NEAR A DRYLINE. AS THE STORMS MOVE EWD INTO THE STRONGER LOW-LEVEL FLOW AND GREATER INSTABILITY...SEVERAL MCS CLUSTERS SHOULD ORGANIZE AND TRACK EWD ACROSS THE MODERATE RISK AREA. FORECAST SOUNDINGS ACROSS THE REGION FROM 21Z TO 03Z SUNDAY AFTERNOON AND EVENING SHOW 0-6 KM SHEAR VALUES RANGING FROM AROUND 60 KT ACROSS THE ARKLATEX TO ABOUT 80 KT IN THE LOWER OH VALLEY. CONSIDERING MODERATE INSTABILITY IS FORECAST ACROSS A BROAD WARM SECTOR...THE ENVIRONMENT APPEARS FAVORABLE FOR SUPERCELLS ACROSS THE ENTIRE REGION. SUPERCELLS WILL BE THE MOST LIKELY MODE WHERE STORMS REMAIN DISCRETE WITH BOW ECHOES AND MULTICELL STORMS LIKELY IN STORM CLUSTERS OF LINEAR ORIENTATION. LOW-LEVEL SHEAR PROFILES APPEAR FAVORABLE FOR TORNADOES WITH THE GREATEST TORNADO THREAT LIKELY IN AREAS WHERE THE INSTABILITY IS MAXIMIZED. THE STRONG VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE HAIL WITH VERY LARGE HAIL POSSIBLE WITH THE STRONGER SUPERCELL STORMS IN THE LATE AFTERNOON AND EARLY EVENING. WIND DAMAGE WILL BE LIKELY ESPECIALLY AS STORM CLUSTERS ORGANIZE INTO LINES DURING THE EVENING HOURS. A LARGE LINEAR MCS SHOULD DEVELOP AND CONTINUE EWD ACROSS THE MS RIVER AND UPPER OH VALLEY. ALTHOUGH STORM INTENSITY SHOULD GRADUALLY DECREASE OVERNIGHT...AT LEAST AN ISOLATED SEVERE WEATHER THREAT SHOULD CONTINUE LATE SUNDAY NIGHT DUE TO THE BROAD WARM SECTOR IN PLACE. ...CNTRL PLAINS... BROAD SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE PLAINS STATES AS A SFC LOW ORGANIZES ALONG A FRONTAL BOUNDARY FROM NRN MO EXTENDING WWD ACROSS SRN NEB AND NRN KS LATE SUNDAY AFTERNOON. LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION AS SFC TEMPS WARM DURING THE DAY. SUPERCELLS WILL BE POSSIBLE DUE TO THE STRONG VERTICAL SHEAR IN PLACE. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK...FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES. AS A RESULT...A FEW OF THE STORMS COULD PRODUCE LARGE HAIL AND/OR WIND DAMAGE DURING THE LATE AFTERNOON OR EARLY EVENING HOURS WITH THE SEVERE WEATHER THREAT LIKELY DECREASING DURING THE EVENING ON SUNDAY DUE TO DECREASING INSTABILITY. ..BROYLES.. 03/11/2006  From SWODY2 at goshenarc.org Sat Mar 11 17:31:47 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 12:31:47 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311173401.25238D4932@mail.goshen.edu> ACUS02 KWNS 111731 SWODY2 SPC AC 111730 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF TX...OK...LA...AR...MS...TN...MO...IA...IL...KY AND TN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS...LOWER MS VALLEY...TN VALLEY...UPPER OH VALLEY AND UPPER MIDWEST... CORRECTED FOR MINOR WORDING ...MS VALLEY/SRN PLAINS... A BROAD UPPER-LEVEL TROUGH WILL CONTINUE IN PLACE ACROSS THE WRN U.S. WITH SOUTHWEST FLOW PRESENT ACROSS THE GREAT PLAINS AND MS VALLEY TONIGHT INTO SUNDAY. A 100 KT MID-LEVEL JET IS FORECAST TO MOVE INTO THE PLAINS STATES SUNDAY AND SUNDAY NIGHT. SHORTWAVE ACTIVITY EMBEDDED IN THE BROAD SOUTHWEST FLOW REGIME WILL CAUSE LARGE-SCALE ASCENT TO INCREASE ACROSS THE REGION BY AFTERNOON. THIS COMBINED WITH A BROAD WARM SECTOR WILL PROVIDE THE INGREDIENTS NECESSARY FOR A WIDESPREAD SEVERE WEATHER THREAT SUNDAY AND SUNDAY NIGHT. MODEL FORECASTS ARE RELATIVELY CONSISTENT...INITIATING WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE WRN EDGE OF THE LOW-LEVEL MOISTURE GRADIENT SUNDAY AFTERNOON. INITIATION WOULD MOST LIKELY OCCUR WHERE SFC HEATING IS MAXIMIZED WITH SEVERAL STORM CLUSTERS DEVELOPING NEAR A SFC LOW ACROSS NRN MO EXTENDING SSWWD ACROSS WRN AR...ERN OK AND NE TX NEAR A DRYLINE. AS THE STORMS MOVE EWD INTO THE STRONGER LOW-LEVEL FLOW AND GREATER INSTABILITY...SEVERAL MCS CLUSTERS SHOULD ORGANIZE AND TRACK EWD ACROSS THE MODERATE RISK AREA. FORECAST SOUNDINGS ACROSS THE REGION FROM 21Z TO 03Z SUNDAY AFTERNOON AND EVENING SHOW 0-6 KM SHEAR VALUES RANGING FROM AROUND 60 KT ACROSS THE ARKLATEX TO ABOUT 80 KT IN THE LOWER OH VALLEY. CONSIDERING MODERATE INSTABILITY IS FORECAST ACROSS A BROAD WARM SECTOR...THE ENVIRONMENT APPEARS FAVORABLE FOR SUPERCELLS ACROSS THE ENTIRE REGION. SUPERCELLS WILL BE THE MOST LIKELY MODE WHERE STORMS REMAIN DISCRETE WITH BOW ECHOES AND MULTICELL STORMS LIKELY IN STORM CLUSTERS OF LINEAR ORIENTATION. LOW-LEVEL SHEAR PROFILES APPEAR FAVORABLE FOR TORNADOES WITH THE GREATEST TORNADO THREAT LIKELY IN AREAS WHERE THE INSTABILITY IS MAXIMIZED. THE STRONG VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE HAIL WITH VERY LARGE HAIL POSSIBLE WITH THE STRONGER SUPERCELL STORMS IN THE LATE AFTERNOON AND EARLY EVENING. WIND DAMAGE WILL BE LIKELY ESPECIALLY AS STORM CLUSTERS ORGANIZE INTO LINES DURING THE EVENING HOURS. A LARGE LINEAR MCS SHOULD DEVELOP AND CONTINUE EWD ACROSS THE MS RIVER AND UPPER OH VALLEY. ALTHOUGH STORM INTENSITY SHOULD GRADUALLY DECREASE OVERNIGHT...AT LEAST AN ISOLATED SEVERE WEATHER THREAT SHOULD CONTINUE LATE SUNDAY NIGHT DUE TO THE BROAD WARM SECTOR IN PLACE. ...CNTRL PLAINS... BROAD SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE PLAINS STATES AS A SFC LOW ORGANIZES ALONG A FRONTAL BOUNDARY FROM NRN MO EXTENDING WWD ACROSS SRN NEB AND NRN KS LATE SUNDAY AFTERNOON. LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION AS SFC TEMPS WARM DURING THE DAY. SUPERCELLS WILL BE POSSIBLE DUE TO THE STRONG VERTICAL SHEAR IN PLACE. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK...FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES. AS A RESULT...A FEW OF THE STORMS COULD PRODUCE LARGE HAIL AND/OR WIND DAMAGE DURING THE LATE AFTERNOON OR EARLY EVENING HOURS WITH THE SEVERE WEATHER THREAT LIKELY DECREASING DURING THE EVENING ON SUNDAY DUE TO DECREASING INSTABILITY. ..BROYLES.. 03/11/2006  From SWODY2 at goshenarc.org Sun Mar 12 06:13:41 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Mar 2006 01:13:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060312061551.E0CA4D46B5@mail.goshen.edu> ACUS02 KWNS 120611 SWODY2 SPC AC 120610 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1210 AM CST SUN MAR 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY ACROSS MUCH OF THE OH/TN VALLEYS...THE MID ATLANTIC COAST STATES...AND PARTS OF THE CNTRL/ERN GULF STATES.... A VERY STRONG MID/UPPER JET STREAK CONTINUES TO NOSE AROUND THE BASE OF A BROAD COLD UPPER TROUGH...WHICH ENCOMPASSES MUCH OF THE WESTERN UNITED STATES. MODELS CONTINUE TO SUGGEST THAT THE MOST SIGNIFICANT IMPULSE EMBEDDED WITHIN THIS FEATURE WILL LIFT OUT OF THE SOUTHERN ROCKIES TODAY. AS THIS OCCURS...THE BROADER SCALE TROUGHING WILL FOLLOW SUIT. POLAR TROUGH IS PROGGED TO REMAIN IN PHASE WITH THE SUBTROPICAL STREAM...AND PROGRESS INTO THE EASTERN HALF OF THE NATION BY LATE MONDAY NIGHT OR EARLY TUESDAY. A SIGNIFICANT SURFACE CYCLONE ACCOMPANYING UPPER SYSTEM IS EXPECTED TO APPROACH THE GREAT LAKES REGION BY 12Z MONDAY...BEFORE CONTINUING TO DEEPEN AND LIFT THROUGH THE EASTERN CANADIAN PROVINCES. A COLD INTRUSION IN ITS WAKE WILL BEGIN TO OVERSPREAD MOST THE NATION EAST OF THE ROCKIES...LIKELY ADVANCING THROUGH ALL BUT EASTERN GULF AND SOUTH ATLANTIC COASTAL AREAS BY 12Z TUESDAY. IN ADVANCE OF THE COLD FRONT...AN INFLUX OF SEASONABLY HIGH BOUNDARY LAYER MOISTURE OFF THE GULF OF MEXICO AND WESTERN ATLANTIC WILL OCCUR THROUGH MUCH OF THE EASTERN STATES. THIS WILL CONTRIBUTE TO POTENTIALLY UNSTABLE ENVIRONMENT...WHICH SHOULD BE SUPPORTIVE OF WIDESPREAD CONVECTIVE DEVELOPMENT...AND THE CONTINUATION OF A SEVERE WEATHER OUTBREAK ALREADY UNDERWAY ACROSS PARTS OF THE MIDDLE MISSISSIPPI VALLEY. ...GREAT LAKES/OHIO AND TN VALLEYS INTO MID ATLANTIC STATES... WHILE SUBSTANTIAL SEVERE POTENTIAL SEEMS LIKELY TO CONTINUE INTO THE NORTHEAST QUARTER OF THE NATION MONDAY...UNCERTAINTIES BEGIN TO ARISE BY THE BEGINNING OF THE PERIOD WHICH COULD TEMPER THREAT...AT LEAST IN TERMS OF NUMBERS OF "SIGNIFICANT" SEVERE EVENTS. A SQUALL LINE MAY BE ONGOING ACROSS THE LOWER OHIO VALLEY AT 12Z MONDAY...WHICH SEEMS LIKELY TO WEAKEN AS IT BEGINS TO OUTRUN PRIMARY UPPER TROUGH AND BETTER PRE-FRONTAL INSTABILITY. THE SURFACE WARM SECTOR WILL BE BROAD...WITH 60F+ SURFACE DEW POINTS WIDESPREAD EAST OF THE MISSISSIPPI VALLEY...LIKELY ACROSS ALL BUT NORTHERN NEW ENGLAND. HOWEVER...SUBSTANTIAL CLOUD COVER MAY LIMIT INSOLATION...AND NORTHEASTWARD ADVECTION OF ELEVATED MIXED LAYER OUT OF THE PLATEAU REGION SEEMS LIKELY TO BECOME SUPPRESSED BY EARLY MONDAY. ALL OF THIS IS EXPECTED TO LIMIT PEAK MIXED LAYER INSTABILITY TO AROUND 1000 J/KG...IN A RELATIVELY NARROW CORRIDOR AHEAD OF COLD FRONT AS IT ADVANCES TOWARD THE APPALACHIANS MONDAY AFTERNOON...PERHAPS SOUTH OF WARM FRONT...ACROSS EASTERN MARYLAND/PENNSYLVANIA. STILL...INSTABILITY SHOULD BE SUFFICIENT IN STRONGLY SHEARED REGIME TO SUPPORT SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND AT LEAST MARGINALLY SEVERE HAIL. ISOLATED SUPERCELLS WILL ALSO BE POSSIBLE...ALONG WITH POTENTIAL FOR TORNADOES. STORMS SEEM LIKELY TO DEVELOP TO THE LEE OF THE NORTH CENTRAL APPALACHIANS...AHEAD OF WEAKENING CONVECTIVE LINE...BY MONDAY AFTERNOON. THIS ACTIVITY SHOULD EVENTUALLY DEVELOP EASTWARD TOWARD NORTHERN MID ATLANTIC COASTAL AREAS...BUT SEVERE THREAT IS EXPECTED TO DIMINISH AS CONVECTION OVERSPREADS MARINE LAYER IN IMMEDIATE VICINITY OF COASTAL AREAS INTO SOUTHERN NEW ENGLAND. OTHERWISE...PRE-FRONTAL LINES OF STRONG/SEVERE STORMS ARE EXPECTED TO DEVELOP THROUGH THE OHIO/TENNESSEE VALLEYS DURING THE PEAK HEATING HOURS. ACTIVITY MAY DEVELOP IN A MORE SCATTERED FASHION AS FAR SOUTH AS THE CENTRAL/EASTERN GULF STATES...BUT DIMINISHING TRENDS ARE EXPECTED BY MONDAY EVENING EAST OF THE CENTRAL/SOUTHERN APPALACHIANS. ..KERR.. 03/12/2006  From SWODY2 at goshenarc.org Sun Mar 12 17:31:50 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Mar 2006 12:31:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060312173358.D08E0D4961@mail.goshen.edu> ACUS02 KWNS 121731 SWODY2 SPC AC 121731 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1131 AM CST SUN MAR 12 2006 VALID 131200Z - 141200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER SERN INDIANA...MUCH OF OH...WRN PA...WRN/CNTRL WV...AND CNTRL/ERN KY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE LOWER MS VALLEY/SERN STATES...AND PARTS OF THE MID ATLANTIC REGION AND SRN NEW ENGLAND... ...SYNOPSIS... VERY DYNAMIC AND PROGRESSIVE UPPER AIR PATTERN IS FORECAST TO CONTINUE INTO DAY 2 OVER THE ERN HALF OF THE NATION. UPPER LOW IS EXPECTED TO BE OVER THE UPPER MS VALLEY AT THE START OF THE PERIOD..AND MOVE ENEWD ACROSS THE NRN GREAT LAKES BY LATE AFTERNOON CONTINUING INTO ERN ONTARIO BY 14/12Z. THE UPPER SYSTEM IS FORECAST TO CONTINUE INTENSIFYING DURING THE PERIOD WITH 12-HR 500 MB HEIGHT FALLS INCREASING TO 240-270M...IN RESPONSE TO 120-130 KT MID LEVEL JET STREAK ACCELERATING ACROSS THE MID MS VALLEY AND GREAT LAKES REGION. AT THE SURFACE...A LOW OVER THE ERN IA/NWRN IL AREA AT 12Z IS FORECAST DEEPEN AS IT TRACKS NEWD TOWARD NRN LOWER MI BY LATE AFTERNOON REACHING WRN QUEBEC BY THE END OF THE PERIOD. A STRONG COLD FRONT EXTENDING SWD FROM THE LOW ALONG A CENTRAL IL..CENTRAL AR..S CENTRAL TX LINE AT 12Z WILL MOVE EWD TO A CENTRAL OH..MIDDLE TN..SWRN LA LINE BY 00Z...CONTINUING OVERNIGHT REACHING NEW ENGLAND...THE MIDDLE ATLANTIC COAST...THEN SWWD ACROSS CENTRAL SC..NWRN FL INTO THE NORTH CENTRAL GULF BY THE END OF PERIOD. A WARM FRONT WILL LIFT NWD ACROSS THE GREAT LAKES IN ADVANCE OF THE SURFACE LOW...BUT ITS NWD MOVEMENT ACROSS THE COASTAL PARTS OF THE MID ATLANTIC STATES MAY BE INHIBITED BY FLOW OFF COOL MARINE LAYER. ...OH VALLEY AND LOWER GREAT LAKES INTO MID ATLANTIC STATES... MODEL GUIDANCE FROM THE 12Z ETA AND GFS...09Z ETAKF CONTROL RUN FROM SREF...AND 00Z HIGH RESOLUTION WRF-NMM ALL INDICATE A PRE-COLD FRONTAL LINE OF STRONG/SEVERE CONVECTION WILL BE ONGOING AT THE START OF THE PERIOD FROM INDIANA INTO WRN PARTS OF KY/TN AND SRN AR. THIS CONVECTION WILL BE MOVING EWD THROUGH A BROAD WARM SECTOR WHERE STRONG SSWLY LOW LEVEL WINDS ARE ADVECTING MOISTURE ACROSS THE OH VALLEY TOWARD THE LOWER GREAT LAKES. SURFACE DEW POINTS WILL GENERALLY BE IN THE 55-60F RANGE ACROSS NRN PARTS OF THE WARM SECTOR INCREASING TO 60-65F FROM PARTS OF THE OH RIVER SWD. RESULTANT EXTENSIVE CLOUD COVER SPREADING DOWNSTREAM FROM THE MORNING CONVECTION WILL LIKELY INHIBIT DIURNAL HEATING ACROSS PARTS OF THE OH VALLEY/LOWER GREAT LAKES. COUPLED WITH MODEST MID LEVEL LAPSE RATES OVER THE WARM SECTOR...IT APPEARS THAT MLCAPE WILL BE LIMITED TO MAXIMUM OF VALUES OF 500-1000 J/KG. STRONG DEEP LAYER VERTICAL SHEAR /50-60 KT IN THE LOWEST 6 KM/...CLOCKWISE TURNING LOW LEVEL HODOGRAPHS AND ASSOCIATED 150-250 M2/S2 0-1 KM SRH...AND INCREASING ISALLOBARIC FORCING WILL ENHANCE QUASI-LINEAR CONVECTIVE ORGANIZATION WITH LEADING BAND SPREADING EWD THROUGH THE DAY. THIS WILL MAINTAIN THREAT FOR PRIMARILY WIDESPREAD DAMAGING WIND GUSTS AND MARGINAL HAIL...ALTHOUGH ISOLATED TORNADOES WILL ALSO BE POSSIBLE ASSOCIATED WITH EMBEDDED SUPERCELLS OR ANY DISCRETE CELLS THAT MAY DEVELOP GIVEN THE STRONG LOW LEVEL SHEAR. IN ADDITION...THERE IS POTENTIAL FOR ADDITIONAL STORMS TO DEVELOP NEAR THE COLD FRONT DURING THE AFTERNOON IF AIR MASS RECOVERY OCCURS IN THE WAKE OF THE INITIAL CONVECTION. THIS MAY RESULT IN MULTIPLE BANDS OF SEVERE STORMS PROGRESSING EWD ACROSS THIS REGION DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH LOW LEVEL MOISTURE/INSTABILITY IS FORECAST TO DIMINISH WITH EASTWARD EXTEND INTO WRN/CENTRAL PARTS OF NY/PA/WV...THE VERY STRONG WIND FIELDS AT ALL LEVELS COUPLED WITH THE EWD SURGE OF THE COLD FRONT SUGGESTS POTENTIAL FOR LOW-TOP SQUALL LINE SEGMENTS TO SPREAD RAPIDLY EWD...CONTINUING A THREAT FOR DAMAGING WIND GUSTS FROM THE EVENING INTO THE OVERNIGHT HOURS. GIVEN THE UNCERTAINTY IN THE NWD PROGRESSION OF WARM FRONT ACROSS THE MID ATLANTIC REGION AND NEW ENGLAND...POTENTIAL FOR DAMAGING WINDS MAY DIMINISH WITH NEWD EXTENT OVER THIS AREA AS STORMS BECOME INCREASINGLY ELEVATED NORTH/EAST OF THE WARM FRONT..ALTHOUGH MARGINAL HAIL MAY PERSIST WITH ELEVATED CELLS. ...TN/LOWER MS VALLEYS INTO SRN APPALACHIANS... STRONG DEEP LAYER SHEAR WILL EXTEND SWD ACROSS THIS REGION...AND INCREASING MOISTURE/INSTABILITY COUPLED WITH A WEAK CAP WILL PROMOTE EWD DEVELOPMENT OF STRONG/SEVERE STORMS ACROSS PARTS OF THE SERN STATES. THIS ACTIVITY IS EXPECTED TO SPREAD EWD TOWARD THE SRN APPALACHIANS DURING THE EVENING HORUS BEFORE DIMINISHING BY 06-09Z. DAMAGING WINDS AND HAIL WILL BE THE PRIMARY THREATS. ..WEISS.. 03/12/2006  From SWODY2 at goshenarc.org Mon Mar 13 06:05:04 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 13 Mar 2006 01:05:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060313060800.715CBD43A2@mail.goshen.edu> ACUS02 KWNS 130605 SWODY2 SPC AC 130604 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1204 AM CST MON MAR 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... CONVECTIVE POTENTIAL IS EXPECTED TO DIMINISH CONSIDERABLY BY THE BEGINNING OF THIS FORECAST PERIOD. MODELS SUGGEST BROAD UPPER TROUGH WILL ENCOMPASS MUCH OF THE EASTERN U.S. BY 12Z TUESDAY... WITH ASSOCIATED DEEP LOW/MID-LEVEL CYCLONE SLOWLY SHIFTING INTO WESTERN QUEBEC. AS UPPER TROUGH AXIS DEVELOPS OFF THE ATLANTIC COAST LATER TUESDAY INTO EARLY WEDNESDAY...MID-LEVEL CYCLONE IS PROGGED TO CONTINUE EASTWARD INTO THE ST. LAWRENCE VALLEY. THIS WILL BE ACCOMPANIED BY SIGNIFICANT SECONDARY SURFACE CYCLOGENESIS ...WHICH MAY COMMENCE AS EARLY AS TUESDAY MORNING OFF THE NORTH ATLANTIC COAST...BEFORE LIFTING INTO THE CANADIAN MARITIMES. IN ITS WAKE... COLD INTRUSION WILL ADVANCE THROUGH THE REMAINDER OF THE ATLANTIC SEABOARD AND SOUTHEAST STATES. UPSTREAM...NEXT SIGNIFICANT SHORT WAVE IMPULSE IS FORECAST TO RAPIDLY PROGRESS INLAND ACROSS THE NORTHERN/CENTRAL CALIFORNIA COAST...THROUGH MUCH OF THE GREAT BASIN BY 12Z WEDNESDAY. THIS WILL BE ACCOMPANIED BY DEVELOPING SURFACE TROUGH IN THE LEE OF THE CENTRAL/SOUTHERN ROCKIES...AND INCREASING WARM ADVECTION FROM GULF COASTAL AREAS THROUGH THE SOUTHERN PLAINS BY LATE IN THE PERIOD. HOWEVER...MOISTURE RETURN IN THE WAKE OF PRIOR FRONTAL PASSAGE IS NOT EXPECTED TO BECOME SUFFICIENT FOR CONVECTIVE DEVELOPMENT... EXCEPT PERHAPS AREAS WEST/SOUTH OF THE LOWER RIO GRANDE VALLEY AND AREAS OFF THE LOWER TEXAS COAST. ...ATLANTIC COAST.. SURFACE COLD FRONT APPEARS LIKELY TO ADVANCE INTO NORTHERN MID ATLANTIC COASTAL AREAS BY AROUND 12Z TUESDAY...AND INTO/ACROSS THE REMAINDER OF THE ATLANTIC COAST BY MIDDAY. ANY THUNDERSTORM ACTIVITY ACROSS NEW ENGLAND IS EXPECTED TO BE BASED ABOVE MARINE LAYER...AND IN ELEVATED LAYER OF MOIST ISENTROPIC ASCENT TO THE NORTH/EAST OF DEVELOPING SURFACE LOW. WITH COLDER AIR ALOFT LAGGING TO THE WEST OF SURFACE COLD FRONT...CAPE WILL BE LIMITED AND RISK OF LARGE HAIL SEEMS SMALL. FARTHER SOUTH...RELATIVELY WARM MID-LEVEL ENVIRONMENT IS ALSO EXPECTED TO MINIMIZE INSTABILITY AHEAD OF COLD FRONT ACROSS THE EASTERN CAROLINAS. WINDOW OF OPPORTUNITY FOR SURFACE HEATING WILL BE LIMITED WITH FRONT EXPECTED TO ADVANCE OFFSHORE BY/OR SHORTLY AFTER 15Z TUESDAY...BUT FORCING MAY STILL BE SUFFICIENT TO SUPPORT NARROW LINE OF CONVECTION BEFORE THIS OCCURS. THIS COULD ENHANCE DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 40-50+ KT MEAN FLOW REGIME...CONTRIBUTING TO AT LEAST SOME POTENTIAL FOR DAMAGING SURFACE GUSTS. ...NORTH CENTRAL PACIFIC COAST INTO NORTHERN GREAT BASIN... STRONG MID-LEVEL COOLING /500 MB COLD CORE BELOW -30C/ IN EXIT REGION OF MID/UPPER JET STREAK WILL CONTRIBUTE TO DESTABILIZATION AS IT NOSES INLAND TUESDAY. THOUGH INSTABILITY SHOULD REMAIN WEAK...THERMODYNAMIC PROFILES ARE EXPECTED TO BE SUPPORTIVE OF SMALL HAIL. BEST POTENTIAL FOR THIS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS SEEMS TO BE NORTHERN CALIFORNIA COASTAL AREAS INTO THE SACRAMENTO VALLEY...WHERE LOW-LEVELS WILL BE WARMER AND MORE MOIST. THREAT ACROSS THIS REGION IS EXPECTED TO DIMINISH AS ONSHORE COMPONENT TO LOW-LEVEL FLOW WEAKENS DURING THE MID TO LATE AFTERNOON. ..KERR.. 03/13/2006  From SWODY2 at goshenarc.org Mon Mar 13 17:23:00 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 13 Mar 2006 12:23:00 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060313172553.DF1AFD4A73@mail.goshen.edu> ACUS02 KWNS 131724 SWODY2 SPC AC 131723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 AM CST MON MAR 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S./MIDDLE ATLANTIC... STRONG UPPER TROUGH OVER THE OH VALLEY WILL HAVE FORCED SFC FRONTAL BOUNDARY EAST OF THE APPALACHIANS LATE IN THE DAY1 PERIOD WITH SFC WIND SHIFT LIKELY NEAR THE DELMARVA COAST BY 12Z TUE MORNING. GIVEN THE LARGE SCALE HEIGHT FALLS AND STRENGTH OF VERTICAL SHEAR OBSERVED ALONG THE FRONTAL ZONE...IT APPEARS THE MITIGATING FACTOR FOR ORGANIZED SEVERE THUNDERSTORMS WILL BE THE LACK OF SIGNIFICANT BOUNDARY LAYER INSTABILITY ACROSS THE CAROLINAS BEFORE WLY FLOW DEEPENS AND FOCUSED CONVERGENCE SHIFTS OFFSHORE. FORECAST SOUNDINGS ACROSS THIS REGION EARLY IN THE PERIOD SUGGEST PARCELS FEEDING THUNDERSTORM UPDRAFTS MAY BE SOMEWHAT ELEVATED...ROOTED AROUND 950MB AND DRIVEN PARTLY DUE TO WARM ADVECTION. MUCAPE WILL LIKELY HOLD AOB 500J/KG LIMITING HAIL THREAT...WHILE SLIGHTLY ELEVATED PARCELS SUGGEST LOCALLY STRONG WINDS WILL BE THE PRIMARY SEVERE THREAT BEFORE COLD FRONT SWEEPS OFFSHORE. ...NORTHERN/CENTRAL CA... NEXT IN A SERIES OF STRONG SHORTWAVE TROUGHS WILL APPROACH THE WEST COAST EARLY IN THE PERIOD...THEN SHIFT INLAND AS SPEED MAX EJECTS EAST ACROSS CNTRL CA INTO NV BY 00Z/15TH. NORTH OF THIS JET AXIS...VERY COLD MID LEVEL TEMPS...H5 THERMAL TROUGH TO MINUS 32C...WILL STEEPEN LAPSE RATES AND AID CONVECTIVE THERMALS ACROSS PORTIONS OF NRN/CNTRL CA...ESPECIALLY IF PARTIAL SUNSHINE DEVELOPS. COLD...STEEP LAPSE RATE ENVIRONMENT FAVORS HAIL WITH STRONG UPDRAFTS BUT OVERALL INSTABILITY DOES NOT APPEAR SUPPORTIVE OF ANYTHING LARGER THAN MARGINAL SEVERE HAIL. ..DARROW.. 03/13/2006  From SWODY2 at goshenarc.org Tue Mar 14 05:46:23 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 14 Mar 2006 00:46:23 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060314054917.8ECC3D47F7@mail.goshen.edu> ACUS02 KWNS 140547 SWODY2 SPC AC 140546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST MON MAR 13 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... MODELS CONTINUE TO SUGGEST THAT ANOTHER LARGE-SCALE UPPER TROUGH WILL BEGIN TO EVOLVE OFF THE PACIFIC COAST DURING THIS FORECAST PERIOD. DOWNSTREAM BROADER SCALE UPPER FLOW ACROSS THE CENTRAL/EASTERN STATES WILL REMAIN BROADLY CONFLUENT IN THE WAKE OF A DEEP CANADIAN MARITIMES CYCLONE AND ASSOCIATED WESTERN ATLANTIC TROUGH. HOWEVER...MID-LEVEL IMPULSE... NOW PROGRESSING INTO THE NORTH CENTRAL PACIFIC COAST...IS PROGGED TO REMAIN FAIRLY STRONG AS IT PROGRESSES ACROSS THE INTERMOUNTAIN WEST INTO THE MID MISSOURI VALLEY BY 12Z THURSDAY. THIS MAY BE ACCOMPANIED BY A WEAKENING IMPULSE IN THE SUBTROPICAL STREAM...WHICH IS FORECAST TO TOP CREST OF MID/UPPER RIDGE CENTERED NEAR THE YUCATAN PENINSULA. WEAK SURFACE CYCLOGENESIS APPEARS LIKELY TO ACCOMPANY POLAR SHORT WAVE IN THE LEE OF THE CENTRAL ROCKIES THROUGH THE CENTRAL PLAINS/MID MISSOURI VALLEY. HOWEVER...IN WAKE OF PRIOR FRONTAL PASSAGE...DESTABILIZATION IS EXPECTED TO BE INSUFFICIENT FOR THUNDERSTORM ACTIVITY. SURFACE RIDGE ASSOCIATED WITH ONGOING COLD INTRUSION TO THE LEE OF THE ROCKIES WILL BE SLOW TO ERODE/RETREAT ACROSS THE SOUTH CENTRAL/SOUTHEASTERN STATES AND NORTHEASTERN GULF OF MEXICO. BUT...A RETURN FLOW OF MOISTURE IS EXPECTED ABOVE RESIDUAL COLD/STABLE SURFACE LAYER...INTO EAST TEXAS AND THE LOWER MISSISSIPPI VALLEY. THIS SHOULD BE CAPPED THROUGH MUCH OF THE PERIOD BY A RELATIVELY WARM MID-LEVEL ENVIRONMENT BENEATH SUBTROPICAL RIDGE. ...SOUTH CENTRAL STATES... BROAD LOWER/MID TROPOSPHERIC ISENTROPIC ASCENT IS EXPECTED THROUGH MOST OF THE PERIOD ACROSS MUCH OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY. THEN...MOST LIKELY LATE WEDNESDAY NIGHT INTO EARLY THURSDAY...MODELS SUGGEST MID-LEVEL HEIGHT FALLS ASSOCIATED WITH SHEARING SUBTROPICAL IMPULSE ABOVE THIS REGIME COULD SUPPRESS INHIBITION SUFFICIENTLY FOR CONVECTIVE DEVELOPMENT. IF THIS OCCURS...IT NOW SEEMS MORE LIKELY THAT MOST UNSTABLE CAPE WILL REMAIN AT OR BELOW 500 J/KG...WHICH SHOULD PRECLUDE AN APPRECIABLE RISK FOR LARGE HAIL. ...PACIFIC NORTHWEST... SCATTERED THUNDERSTORMS ASSOCIATED WITH COLD UPPER TROUGH MAY APPROACH SHORE WEDNESDAY/WEDNESDAY NIGHT...BUT LARGE-SCALE SUPPORT DOES NOT APPEAR FAVORABLE FOR ACTIVITY TO DEVELOP INLAND BEYOND IMMEDIATE COASTAL AREAS. ..KERR.. 03/14/2006  From SWODY2 at goshenarc.org Tue Mar 14 17:18:09 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 14 Mar 2006 12:18:09 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060314172101.A5D33D4A74@mail.goshen.edu> ACUS02 KWNS 141719 SWODY2 SPC AC 141718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CST TUE MAR 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...EAST TX/LOWER MS VALLEY... LATEST MODEL GUIDANCE MAINTAINS CA UPPER SHORTWAVE TROUGH WILL EJECT EWD ACROSS THE CNTRL ROCKIES AND DEAMPLIFY SOMEWHAT WITHIN WLY FLOW REGIME OVER THE PLAINS LATE IN THE PERIOD. THIS FEATURE WILL AID RETURN FLOW AND WARM ADVECTION ACROSS TX INTO THE LOWER MS VALLEY REGION WHERE GRADUAL AIRMASS DESTABILIZATION IS EXPECTED ABOVE THE BOUNDARY LAYER...ESPECIALLY ALONG ERN FRINGE OF STEEP LAPSE RATE PLUME OFF THE SRN HIGH PLAINS REGION. FORECAST SOUNDINGS SUGGEST BUOYANCY IF PARCELS ARE LIFTED NEAR 850 MB...MUCAPE ROUGHLY ON THE ORDER OF 500 J/KG. ELEVATED CONVECTION WILL LIKELY EVOLVE LATE IN THE PERIOD FROM EAST TX INTO AR AND LA AS SUSTAINED...INCREASINGLY MOIST...SWLY TRAJECTORY ENHANCES ASCENT ATOP COOLER LOW LEVEL AIRMASS. ...PACIFIC NW... ISOLATED THUNDERSTORMS MAY DEVELOP IN ASSOCIATION WITH NEXT SHORTWAVE TROUGH APPROACHING THE PACIFIC NW COAST WEDNESDAY. VERY COLD...STEEP LAPSE RATE ENVIRONMENT...SUGGESTS CONVECTION IS LIKELY...BUT LIGHTNING SHOULD BE LIMITED EXCEPT FOR NEAR THE MARINE LAYER DUE TO MEAGER INSTABILITY INLAND. ..DARROW.. 03/14/2006  From SWODY2 at goshenarc.org Wed Mar 15 05:58:20 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 15 Mar 2006 00:58:20 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060315060109.1074FD4645@mail.goshen.edu> ACUS02 KWNS 150559 SWODY2 SPC AC 150558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST TUE MAR 14 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS THU AFTN/EVE ACROSS PARTS OF S CNTRL/SE TEXAS AND WRN LA.... MODELS CONTINUE TO INDICATE THAT A BROAD UPPER TROUGH WILL BEGIN TO EVOLVE ACROSS THE EASTERN PACIFIC LATER TODAY INTO 12Z THURSDAY... BEFORE AMPLIFICATION OCCURS ALONG THE PACIFIC COAST THROUGH THE REMAINDER OF THIS FORECAST PERIOD. DIFLUENT DOWNSTREAM REGIME MAY SPREAD TO THE IMMEDIATE LEE OF THE ROCKIES...BUT BROADLY CONFLUENT UPPER FLOW WILL PERSIST EAST OF THE HIGH PLAINS INTO BROAD WESTERN ATLANTIC TROUGH. WITHIN THIS PATTERN...A SIGNIFICANT IMPULSE IN BELT OF POLAR WESTERLIES IS PROGGED TO ACCELERATE SOUTHEAST OF THE MID MISSOURI VALLEY THROUGH MUCH OF THE LOWER OHIO VALLEY BY 12Z FRIDAY...AHEAD OF ANOTHER SHORT WAVE DIGGING SOUTH OF THE CENTRAL CANADIAN PROVINCES. A SHEARING IMPULSE IN THE SUBTROPICAL STREAM MAY ACCOMPANY LEAD SYSTEM...AND MODELS SUGGEST LARGE-SCALE FORCING WILL CONTRIBUTE TO EROSION/RETREAT OF SOUTH CENTRAL/SOUTHEAST STATES SURFACE RIDGE. THIS SHOULD ALLOW FOR A RETURN FLOW OFF THE GULF OF MEXICO...THROUGH SOUTHEAST TEXAS AND THE LOWER MISSISSIPPI VALLEY...AND IN A NARROW TONGUE TO THE VICINITY OF A WEAK SURFACE CYCLONE ACCOMPANYING POLAR TROUGH THROUGH THE LOWER OHIO VALLEY. ...SOUTH CENTRAL STATES... AHEAD OF NEXT COLD INTRUSION THROUGH THE PLAINS AND MISSISSIPPI VALLEY...MODELS SUGGEST AN ELEVATED MIXED LAYER WILL ADVECT EAST NORTHEAST OF THE MEXICAN PLATEAU THROUGH MUCH OF SOUTHERN/EASTERN TEXAS INTO WESTERN LOUISIANA. THIS WILL CONTRIBUTE TO STEEP LAPSE RATES ABOVE A DEEPENING MOIST BOUNDARY WITH SURFACE DEW POINTS CLIMBING IN EXCESS OF 60F. BY THURSDAY AFTERNOON...MIXED LAYER CAPE SEEMS LIKELY TO EXCEED 1000 J/KG...WITH INHIBITION WEAKENING IN RESPONSE TO MID-LEVEL COOLING IN WAKE OF SUBTROPICAL IMPULSE. MODELS SUGGEST THIS MAY BE ENOUGH FOR SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT. AIDED BY FAVORABLE DEEP LAYER SHEAR BENEATH MODERATELY STRONG MID/UPPER FLOW...ISOLATED SUPERCELLS ARE EXPECTED. RATHER LIGHT LOW-LEVEL FLOW AND SMALL LOW-LEVEL HODOGRAPHS SHOULD LIMIT TORNADO POTENTIAL...BUT LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE. THIS SHOULD CONTINUE INTO EARLY EVENING...BEFORE COLD SURFACE RIDGE NOSES INTO THE WESTERN GULF COAST. IN RESPONSE TO DEVELOPMENTS IN THE UPSTREAM UPPER FLOW...MODELS SUGGEST LOW-LEVEL WARM ADVECTION WILL INCREASE ABOVE FRONTAL INVERSION LATE THURSDAY NIGHT...FROM PARTS OF THE TEXAS HILL COUNTRY INTO THE TEXAS SOUTH PLAINS. ELEVATED MOISTURE RETURN AND STEEPENING MID-LEVEL LAPSE RATES MAY CONTRIBUTE TO ENOUGH CAPE FOR AT LEAST MARGINAL SEVERE HAIL POTENTIAL TOWARD 12Z FRIDAY. ...LOWER OHIO VALLEY... MODELS CONTINUE TO SUGGEST ENOUGH DESTABILIZATION WILL OCCUR WITH POLAR TROUGH BY THURSDAY AFTERNOON FOR RISK OF WEAK THUNDERSTORM ACTIVITY. THIS SEEMS MOST LIKELY NEAR/JUST SOUTHEAST OF SURFACE LOW...FROM PARTS OF SOUTHEASTERN INDIANA INTO SOUTHERN OHIO...NEAR OR SHORTLY AFTER PEAK DAYTIME HEATING. ...PACIFIC NORTHWEST... POTENTIAL FOR ISOLATED THUNDERSTORMS WILL EXIST THURSDAY AFTERNOON AND EVENING AS COLD MID-LEVEL CIRCULATION...WITHIN DEVELOPING LARGER SCALE TROUGH...PROGRESSES INTO WESTERN WASHINGTON. ..KERR.. 03/15/2006  From SWODY2 at goshenarc.org Wed Mar 15 17:27:30 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 15 Mar 2006 12:27:30 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060315173016.91231D4B0D@mail.goshen.edu> ACUS02 KWNS 151727 SWODY2 SPC AC 151726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST WED MAR 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN LA INTO SCNTRL TX... ...SOUTH CENTRAL U.S... WEAK UPPER RIDGING WILL BUILD INTO THE SRN PLAINS LATE IN THE DAY2 PERIOD AS STRONG SPEED MAX EJECTS ACROSS MO INTO NC. THIS FEATURE WILL BE PARTLY RESPONSIBLE FOR SWD PLUNGE OF CT AIR THROUGH THE MID SECTION OF THE COUNTRY FORCING SFC BOUNDARY DEEP INTO TX/LA BY PEAK HEATING. IN THE ABSENCE OF LARGE SCALE SUPPORT FOR DEEP ASCENT ALONG THIS ADVANCING COLD FRONT...IT APPEARS STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL IN POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE COASTAL PLAINS OF TX INTO SWRN PORTIONS OF LA BY LATE AFTERNOON. FORECAST SOUNDINGS SUGGEST BOUNDARY LAYER PARCELS WILL BECOME WEAKLY INHIBITED AFTER 21Z AS LOW LEVEL LAPSE RATES STEEPEN AND SFC TEMPERATURES WARM TO NEAR 80 DEG. IT APPEARS SCATTERED THUNDERSTORMS WILL DEVELOP ALONG ADVANCING COLD FRONT WHILE VEERING PROFILES WITH HEIGHT AND SUFFICIENT VERTICAL SHEAR ENHANCE THE THREAT FOR ROTATING STORMS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH MORE SUSTAINED UPDRAFTS. LATER IN THE OVERNIGHT PERIOD...STRENGTHENING LLJ ACROSS THE EDWARDS PLATEAU INTO WEST TX WILL AID ELEVATED CONVECTIVE THREAT FOR PARCELS LIFTED NEAR 800 MB. MARGINAL SEVERE HAIL MAY ACCOMPANY THIS ACTIVITY AS IT SPREADS/DEVELOPS NWD ACROSS THE TX SOUTH PLAINS. ...OH VALLEY... PLUME OF STEEP LAPSE RATES WILL SPREAD ACROSS THE OH VALLEY...NORTH OF STRONG SPEED MAX...AHEAD OF WELL DEFINED SHORTWAVE TROUGH THURSDAY. ISOLATED THUNDERSTORMS MAY EVOLVE WITHIN WARM ADVECTION ZONE JUST EAST OF ADVANCING SFC LOW...MAINLY DURING THE DAYTIME HOURS. ...PACIFIC NW... YET ANOTHER SFC FRONT WILL MOVE ONSHORE ALONG THE WA/ORE COAST EARLY IN THE PERIOD WITH ONSHORE FLOW AND MORE BUOYANT MARITIME AIRMASS BENEATH COLD UPPER TROUGH. ISOLATED LOW TOPPED THUNDERSTORMS MAY DEVELOP ACROSS THIS REGION THROUGH THE PERIOD...ESPECIALLY GIVEN THE SUSTAINED SECONDARY LOW LEVEL CONVERGENT TROUGH JUST OFF THE COAST. ..DARROW.. 03/15/2006  From SWODY2 at goshenarc.org Sat Mar 18 06:03:07 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 18 Mar 2006 01:03:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060318060608.4D8EED4653@mail.goshen.edu> ACUS02 KWNS 180603 SWODY2 SPC AC 180602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 AM CST SAT MAR 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL AND SRN HIGH PLAINS THROUGH TX AND THE LOWER MS VALLEY... ...SYNOPSIS... UPPER TROUGH NOW OVER CNTRL CA IS FORECAST TO CONTINUE EWD THROUGH THE SWRN U.S. AND INTO THE SRN PLAINS BY SUNDAY NIGHT. POTENTIAL WILL ALSO EXIST FOR MINOR IMPULSES EMBEDDED WITHIN THE SRN STREAM TO EJECT NEWD INTO TX SUNDAY AHEAD OF THE MAIN UPPER TROUGH. MODELS AGREE THAT A STRONG SPEED MAX WILL EJECT NEWD THROUGH WRN TX SUNDAY NIGHT ACCOMPANIED BY A PACIFIC FRONT. A SURFACE BOUNDARY CURRENTLY ACROSS S TX WILL PERSIST IN ADVANCE OF THIS FEATURE AND WILL LIFT SLOWLY NWD THROUGH THE DAY. BY SUNDAY AFTERNOON...THIS BOUNDARY SHOULD EXTEND FROM LA NWWD THROUGH CNTRL AND NWRN TX WHERE IT WILL INTERSECT WITH THE DRYLINE. ...SRN HIGH PLAINS THROUGH TX AND SRN PARTS OF THE LOWER MS VALLEY... GRADIENT BETWEEN SURFACE RIDGE OVER THE ERN HALF OF THE COUNTRY AND LEE TROUGH OVER THE CNTRL/SRN HIGH PLAINS WILL MAINTAIN A SLY LOW LEVEL COMPONENT THROUGH SUNDAY. GULF MOISTURE WITH DEWPOINTS IN THE MID TO UPPER 60S RESIDING S OF FRONT OVER S TX WILL ADVECT NWWD UNDERNEATH PLUME OF STEEPER LAPSE RATES CONTRIBUTING TO DESTABILIZATION SUNDAY AFTERNOON FROM PARTS OF WRN/CNTRL TX NWD INTO PARTS OF THE CNTRL HIGH PLAINS. THERE IS SOME CONCERN THAT POTENTIAL FOR EXTENSIVE HIGH CLOUDS COULD HAVE A DAMPENING EFFECT ON HEATING. ELY FLOW AT THE SURFACE AND LOW CLOUDS WILL PERSIST N OF THE SURFACE FRONT ACROSS NRN TX INTO OK. HOWEVER...SLY FLOW ABOVE THE SURFACE LAYER WILL LIKELY RESULT IN SOME ELEVATED INSTABILITY...ESPECIALLY FROM NWRN TX INTO WRN OK WHERE STEEPER LAPSE RATES WILL EXIST. ELEVATED STORMS MAY BE ONGOING FROM NRN TX INTO OK SUNDAY MORNING. THIS ACTIVITY SHOULD SHIFT EWD THROUGH THE LOWER MS VALLEY DURING THE DAY. AS THE WARM SECTOR DESTABILIZES AND CAP WEAKENS...OTHER STORMS MAY DEVELOP FARTHER W OVER THE HIGHER TERRAIN OF WRN TX/ERN NM AND IN VICINITY OF THE DRYLINE. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS WITH ANY SURFACE BASED ACTIVITY. STORMS ARE EXPECTED TO BECOME MORE NUMEROUS BY LATE AFTERNOON AND EVENING OVER THE SRN HIGH PLAINS AND WRN TX AS FORCING FOR ASCENT INCREASES WITHIN EXIT REGION OF EJECTING SPEED MAX. OTHER STORMS SHOULD DEVELOP AS THE PACIFIC FRONT OVERTAKES THE DRYLINE ACROSS WRN TX...AND THIS ACTIVITY WILL LIKELY EVOLVE INTO AN MCS AS IT SPREADS EWD THROUGH TX OVERNIGHT. THE SEVERE THREAT SHOULD INCREASE TOWARD THE LOWER MS VALLEY LATE IN THE PERIOD AS THE LOW LEVEL JET STRENGTHENS AND POTENTIAL FOR SURFACE BASED STORMS WITHIN THE WARM SECTOR INCREASES. ..DIAL.. 03/18/2006  From SWODY2 at goshenarc.org Sat Mar 18 17:30:50 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 18 Mar 2006 12:30:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060318173352.33274D4703@mail.goshen.edu> ACUS02 KWNS 181731 SWODY2 SPC AC 181730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST SAT MAR 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN PLAINS INTO THE LWR MS VLY... ...SYNOPSIS... THE UPPER TROUGH ACROSS THE WRN STATES WILL BEGIN TO MOVE EWD ON SUNDAY AS THE UPPER LOW ACROSS SERN CANADA ELONGATES E-W AND THE TROUGH OVER THE ALEUTIANS BEGINS TO DIG SEWD. WHILE LOW-AMPLITUDE IMPULSES WILL EJECT NEWD FROM THE BASE OF THE TROUGH DURING SUNDAY...THE PRIMARY TROUGH WILL WAIT UNTIL SUNDAY NIGHT OR EARLY MON TO BODILY TRANSLATE EWD ACROSS THE SRN PLAINS. AT THE SFC...PRIMARY FRONT SITUATED FROM THE NRN GULF BASIN WWD ACROSS CNTRL TX AND THE SRN HIGH PLAINS TODAY WILL REDEVELOP NWD INTO THE LWR MS VLY...NRN TX AND THE CNTRL HIGH PLAINS BY SUNDAY EVENING. LEE-LOWS WILL STRENGTHEN OVER NERN NM AND ACROSS SWRN TX EARLY SUNDAY...WITH A DRY LINE MIXING EWD INTO THE TX SPLAINS AND WCNTRL TX LATE SUNDAY AFTN. EVENTUALLY...A COLD FRONT WILL OVERTAKE THE DRY LINE AND MOVE EWD ACROSS WRN OK AND CNTRL TX BY 12Z MON. ...SRN PLAINS TO THE LWR MS VLY... SELY LOW-LEVEL FLOW WILL CONTINUE TO ADVECT MID-UPPER 60S DEW POINTS NWWD ACROSS CNTRL/SRN TX BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES TODAY AND SUNDAY. THIS WILL CONTRIBUTE TO DESTABILIZATION SUNDAY AFTN FROM PARTS OF WRN/CNTRL TX NWD INTO PARTS OF THE CNTRL PLAINS. POTENTIAL FOR ONGOING TSTM CLUSTERS AND CLOUDS WILL PROBABLY IMPEDE NWD MOVEMENT OF THE WARM FRONT. BUT...SLY FLOW ABOVE THE BOUNDARY LAYER WILL SUPPORT ELEVATED INSTABILITY AND A CONTINUED RISK OF LARGE HAIL...ESPECIALLY ACROSS N TX AND SWRN OK. ELEVATED CLUSTERS OF TSTMS WILL LIKELY BE ONGOING ACROSS OK/N TX AT 12Z SUNDAY ALONG NOSE OF A SLY LLJ. THIS ACTIVITY SHOULD SHIFT EWD THROUGH THE LWR MS VLY DURING THE DAY. MEANWHILE...THE WARM SECTOR SHOULD GROW SPATIALLY DURING SUNDAY AFTN ACROSS CNTRL/W TX. STRONGEST HEATING SHOULD TAKE PLACE FROM THE TX SPLAINS SWD INTO SWRN TX. WEAK HEIGHT FALLS...INFLOW OF MOIST BOUNDARY LAYER AND HEATING ALONG THE DRYLINE/HIGHER TERRAIN WILL LIKELY RESULT IN TSTM INITIATION DURING THE AFTN. SUPERCELL WIND PROFILES WILL EXIST ACROSS THESE AREAS AND LARGE HAIL /POSSIBLY GREATER THAN 2 INCHES IN DIAMETER/ WILL BE THE PRIMARY THREAT...THOUGH ISOLD TORNADOES MAY OCCUR. AS FORCING FOR ASCENT SPREADS EWD OVERNIGHT...TSTMS WILL LIKELY EVOLVE INTO ONE OR MORE MCS/S AND SPREAD/DEVELOP EWD ALONG THE WARM FRONT ACROSS NRN/CNTRL TX. ALONG WITH A HAIL THREAT...DAMAGING WINDS AND ISOLD TORNADOES WILL BE THREATS SUNDAY NIGHT AS FAR EAST AS THE LWR MS VLY AS THE LLJ QUICKLY DEVELOPS EWD. A SECONDARY AREA OF POSSIBLE SEVERE TSTMS WILL EXIST ALONG THE NRN EDGE OF THE MCS ACROSS THE TX PNHDL INTO WRN OK LATE SUNDAY NIGHT. THIS ACTIVITY WILL LARGELY BE ORIENTED WITHIN PARALLEL DEEP SLY FLOW DOWNSTREAM FROM THE PRIMARY THROUGH. THUS...STORMS MAY EVOLVE INTO A LEWPY STRUCTURE AND PRIMARY REMAIN ELEVATED WITH HAIL THE MAIN THREAT. ..RACY.. 03/18/2006  From SWODY2 at goshenarc.org Sun Mar 19 06:00:36 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 19 Mar 2006 01:00:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060319060333.DC90FD4703@mail.goshen.edu> ACUS02 KWNS 190601 SWODY2 SPC AC 190600 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1200 AM CST SUN MAR 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EXTREME ERN TX INTO PARTS OF THE LOWER MS VALLEY AND SERN U.S.... ...SYNOPSIS... THE UPPER TROUGH NOW OVER THE SWRN U.S. WILL CONTINUE EWD THROUGH MONDAY AND DE AMPLIFY BY LATE MONDAY AS IT MOVES INTO THE BLOCKING PATTERN OVER THE ERN THIRD OF THE COUNTRY. SEVERAL VORTICITY MAXIMA WILL ROTATE THROUGH THIS FEATURE. THE UPPER LOW WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL CONTINUE THROUGH ERN TX EARLY MONDAY AND INTO THE LOWER MS VALLEY BY AFTERNOON. INITIAL SURFACE LOW IS FORECAST TO OCCLUDE OVER ERN OK WITH SECONDARY LOW DEVELOPMENT EXPECTED FARTHER SE OVER THE LOWER MS VALLEY DURING THE DAY. THE LOW LEVEL JET WILL STRENGTHEN OVER THE LOWER MS VALLEY IN ADVANCE OF THE SHORTWAVE TROUGH...RESULTING IN NWD ADVANCE OF BOUNDARY NOW OVER THE NRN GULF. THE WARM SECTOR MAY SPREAD INLAND INTO MUCH OF LA...CNTRL MS AND AL MONDAY AFTERNOON. ...LOWER MS VALLEY THROUGH PARTS OF THE SERN STATES... STORMS WILL LIKELY BE ONGOING EARLY MONDAY WITHIN ZONE OF ISENTROPIC ASCENT N OF SURFACE FRONT ACROSS PARTS OF AR...CNTRL AND NRN MS INTO THE TN VALLEY. THIS MAY SERVE TO SLOW THE NWD RETREAT OF THE BOUNDARY DURING THE DAY. CURRENT THINKING IS THAT THE BOUNDARY MAY LIFT AS FAR N AS NRN LA...CNTRL MS AND AL BY MID TO LATE AFTERNOON. A STRONG SLY LOW LEVEL JET ASSOCIATED WITH THE CYCLONICALLY CURVED JET EXIT REGION WILL LIKELY EXIST OVER THE LOWER MS VALLEY EARLY MONDAY. THE LAST FEW RUNS OF THE GFS HAVE BEEN VEERING THIS FEATURE TO WSWLY MONDAY AFTERNOON WHICH...IF OCCURS...COULD SERVE AS A LIMITING FACTOR. HOWEVER...THE NAM MAINTAINS A MORE SLY COMPONENT. IN EITHER CASE...POTENTIAL WILL EXIST FOR CLOUDS AND PRE-FRONTAL CONVECTION TO DEVELOP EARLY WITHIN THE WARM SECTOR... AND THIS COULD LIMIT INSTABILITY. NEVERTHELESS...SOME DESTABILIZATION IS EXPECTED AS RICH LOW LEVEL MOISTURE ADVECTS INLAND AND WHERE POCKETS OF HEATING CAN DEVELOP. STORMS DEVELOPING WITHIN THE PRE-FRONTAL WARM SECTOR SHOULD INTENSIFY DURING THE DAY. STRONG VERTICAL SHEAR PROFILES WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS. MID LEVEL DRY SLOT WILL ADVANCE EWD DURING THE AFTERNOON RESULTING IN POTENTIAL FOR DESTABILIZATION FARTHER W IN VICINITY OF FRONT OVER THE LOWER MS VALLEY ONCE LOW CLOUDS MIX OUT. ANY STORMS THAT DEVELOP ALONG THE FRONT WILL ALSO HAVE THE POTENTIAL TO BECOME SEVERE. STRONGEST WARM SECTOR ACTIVITY IS EXPECTED TO CONTINUE EWD THROUGH PARTS OF MS AND AL DURING THE AFTERNOON AND EVENING. STORMS SHOULD BEGIN TO WEAKEN OVERNIGHT AS THE LOW LEVEL JET VEERS AND INSTABILITY BECOMES MORE MARGINAL TOWARD GA AND SC. ..DIAL.. 03/19/2006  From SWODY2 at goshenarc.org Sun Mar 19 17:34:03 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 19 Mar 2006 12:34:03 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060319173658.1003DD4A96@mail.goshen.edu> ACUS02 KWNS 191735 SWODY2 SPC AC 191734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CST SUN MAR 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN PLAINS INTO A LARGE PART OF THE DEEP S... ...SYNOPSIS... A TREND TOWARD A MORE PROGRESSIVE FLOW REGIME WILL CONTINUE EARLY THIS WEEK. SRN PARTS OF THE WRN STATES UPPER TROUGH WILL BEGIN TO SWING EWD TODAY AS THE NEXT IMPULSE DROPS TOWARD THE NRN CA COAST TONIGHT. THE FIRST TROUGH WILL BECOME NEGATIVELY TILTED EARLY MON...THEN CLOSE OFF INTO A LOW BEFORE ELONGATING E-W ACROSS THE MID-MS VLY ON TUE. PRIMARY SFC LOW WILL CONSOLIDATE OVER NW TX TONIGHT...THEN TRACK NEWD INTO THE TN VLY BY 12Z TUE. A WARM FRONT WILL REDEVELOP NWD THROUGH THE LWR MS VLY AND DEEP S WITH A COLD FRONT SWEEPING EWD ACROSS THE SRN PLAINS AND INTO THE LWR MS VLY LATE MON NIGHT. ...CNTRL-SERN TX ACROSS THE DEEP S... SEVERAL CLUSTERS OF TSTMS ARE EXPECTED TO BE ONGOING EARLY MON WITHIN A ZONE OF STRONG ISENTROPIC LIFT N OF THE WARM FRONT FROM THE SRN PLAINS INTO THE TN VLY. THOUGH THIS MAY IMPEDE NWD MOVEMENT OF THE FRONT...GIVEN TRACK OF THE 150 METER/12 HR H5 HEIGHT FALLS...WARM FRONT MAY REDEVELOP AS FAR N AS NRN LA...CNTRL MS AND WCNTRL-SRN AL BY MID-LATE MON AFTN. PRIND THAT THE STRONGEST MCS WILL BE ONGOING AT 12Z MON ACROSS PORTIONS OF CNTRL/ERN TX. DOWNSTREAM...BOUNDARY LAYER WILL CONTINUE TO MOISTEN AND DESTABILIZE THROUGH MON AFTN. UNCERTAINTY EXISTS ON HOW WIDESPREAD CLOUDS WILL BE IN THE WARM SECTOR...BUT CURRENT THINKING IS THAT AT LEAST LOCAL HEATING WILL RESULT IN POCKETS OF MODEST INSTABILITY. AS A RESULT...TSTMS WILL BECOME MORE WIDESPREAD ACROSS THE LWR MS VLY MON AFTN...THEN SPREAD ENEWD ACROSS THE DEEP S/TN VLY THROUGH MON NIGHT. STRONG VERTICAL SHEAR PROFILES WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...PARTICULARLY AS THE STORMS TRACK VCNTY THE WARM FRONT AND SUB-SYNOPTIC LOWS EARLY IN STORM LIFE CYCLES. ACTIVITY MAY TEND TO BECOME MORE LINEAR WITH TIME WITH LEWPS/BOWS. SEVERE PROBABILITIES WILL DECREASE WITH EWD EXTENT OVERNIGHT MON AS THE STORMS ENCOUNTER THE COLD WEDGE ACROSS NERN AL...NRN GA AND THE CAROLINAS. IF PRE-FRONTAL WARM SECTOR APPEARS TO BE MORE UNSTABLE IN FUTURE OUTLOOKS...AN UPGRADE TO MDT RISK IS POSSIBLE ACROSS THE LWR MS VLY INTO CNTRL/SRN MS. ...SRN PLAINS... A SECONDARY AREA OF SEVERE WEATHER POTENTIAL WILL DEVELOP DURING MON AFTN ALONG THE COLD FRONT FROM PARTS OF SRN OK INTO NERN TX. ANY CLEARING IN WAKE OF THE WARM CONVEYOR ACROSS THE LWR MS VLY WILL CONTRIBUTE TO DESTABILIZATION ALONG THE COLD FRONT GIVEN DECREASING TEMPERATURES ALOFT AND RESIDUAL BOUNDARY LAYER MSTR. VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED STORMS WITH HAIL AND POSSIBLE ISOLD TORNADOES. THIS ACTIVITY WILL MOVE ENEWD ACROSS AR AND INTO THE TN VLY OVERNIGHT. ..RACY.. 03/19/2006  From SWODY2 at goshenarc.org Mon Mar 20 05:55:10 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Mar 2006 00:55:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060320055821.64C2FD4A94@mail.goshen.edu> ACUS02 KWNS 200555 SWODY2 SPC AC 200555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 PM CST SUN MAR 19 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN GA INTO THE NRN HALF OF THE FL PENINSULA... ...SYNOPSIS... THE UPPER TROUGH CURRENTLY OVER THE SWRN STATES WILL CONTINUE EWD AND DEAMPLIFY OVER THE TN/OH VALLEY TUESDAY AS IT MOVES INTO THE BLOCK SITUATED OVER THE ERN THIRD OF THE COUNTRY. ATTENDANT SURFACE LOW WILL OCCLUDE OVER THE TN VALLEY...WHILE SECONDARY CYCLOGENESIS COMMENCES ALONG BAROCLINIC ZONE OFF THE CAROLINA COAST TUESDAY MORNING. COLD FRONT WILL CONTINUE SEWD INTO THE NRN FL PENINSULA BY LATE TUESDAY AFTERNOON AND EVENING. ...SRN GA THROUGH THE NRN HALF OF THE FL PENINSULA... THE LOW LEVEL JET WILL VEER TO WLY OVER THE SERN U.S. AND THE NERN GULF LATE MONDAY AND PERSIST INTO TUESDAY. THIS WILL CONTRIBUTE TO THE EWD ADVECTION OF RICHER GULF MOISTURE INTO THE PRE-FRONTAL WARM SECTOR ACROSS THE NRN FL PENINSULA. THE ATMOSPHERE IS EXPECTED TO BECOME MODERATELY UNSTABLE AS HEATING COMMENCES. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH EWD ADVANCING MID LEVEL JET IS EXPECTED TO REMAIN WELL N OF THIS REGION...AND THIS COULD SERVE TO LIMIT STORM COVERAGE. HOWEVER...SEA BREEZE CIRCULATIONS AND RESIDUAL OUTFLOW BOUNDARIES FROM MORNING CONVECTION COULD SERVE TO INITIATE NEW STORMS WITHIN THE PRE-FRONTAL WARM SECTOR. STRONG MID LEVEL FLOW ON THE SRN PERIPHERY OF THE UPPER TROUGH WILL MAINTAIN UNIDIRECTIONAL SHEAR PROFILES FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND THE PRIMARY THREATS. THREAT SHOULD DIMINISH DURING THE EVENING WITH LOSS OF HEATING. ..DIAL.. 03/20/2006  From SWODY2 at goshenarc.org Mon Mar 20 17:02:02 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Mar 2006 12:02:02 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060320170452.56494D4700@mail.goshen.edu> ACUS02 KWNS 201703 SWODY2 SPC AC 201702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1102 AM CST MON MAR 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE ACROSS THE SOUTHEAST STATES...MAINLY PARTS OF NRN FL.... MODELS INDICATE THAT HIGH LATITUDE BLOCKING WILL PERSIST THROUGH THIS FORECAST PERIOD...WITH AN ASSOCIATED CLOSED LOW LINGERING OVER SOUTHEAST CANADA AND THE NORTHEASTERN STATES...WHILE ANOTHER CLOSED LOW EVOLVES OVER THE NORTHEAST PACIFIC. FARTHER SOUTH...A SOUTHERN BELT OF POLAR WESTERLIES...AND THE SUBTROPICAL WESTERLIES...WILL COMPRISE A BROAD STRONG...GENERALLY ZONAL FLOW ACROSS THE SOUTHERN TIER STATES. WITHIN THIS REGIME...A COUPLE OF EMBEDDED SHORT WAVES WILL REMAIN OR BECOME MORE PROGRESSIVE. THE LEAD IMPULSE...WHICH IS NOW ADVANCING INTO/ACROSS THE SOUTH CENTRAL PLAINS...IS FORECAST TO LIFT INTO THE MIDDLE MISSISSIPPI VALLEY BY 12Z TUESDAY...BEFORE TURNING SOUTHEASTWARD AND ACCELERATING THROUGH CONFLUENT FLOW INTO THE WESTERN ATLANTIC BY 12Z WEDNESDAY. AN UPSTREAM SHORT WAVE TROUGH WILL BE A BIT SLOWER...BUT IS STILL PROGGED TO MIGRATE FROM CENTRAL/SOUTHERN CALIFORNIA INTO THE FOUR CORNERS REGION BY THE END OF THE FORECAST PERIOD. ...SOUTHEAST STATES... WITH THE BROADER SCALE PATTERN REMAINING SUPPORTIVE OF HIGH SURFACE PRESSURE ACROSS MUCH OF EASTERN NORTH AMERICA...SURFACE CYCLOGENESIS ACCOMPANYING SOUTHERN STREAM IMPULSE IS EXPECTED TO REMAIN WEAK. AN INITIAL PRIMARY SURFACE LOW LIKELY WILL ALREADY BE WEAKENING OVER THE TENNESSEE VALLEY BY THE BEGINNING OF THE FORECAST PERIOD...WITH SECONDARY SURFACE WAVE DEVELOPMENT OCCURRING NEAR/OR SOUTHEAST OF THE SOUTH CAROLINA COAST. THIS SHOULD LIMIT EXTENT OF SEVERE THREAT FOR THIS FORECAST PERIOD. IN FACT...AS MODERATELY STRONG LOW-LEVEL WIND FIELDS BECOME WESTERLY RATHER EARLY IN THE DAY...CONVECTIVE POTENTIAL WILL DIMINISH ACROSS MUCH OF THE SOUTHEAST. AN EXCEPTION COULD BE MOIST PRE-FRONTAL ENVIRONMENT ACROSS PARTS OF NORTHERN FLORIDA AND THE FLORIDA PENINSULA...WHERE DEEP LAYER SHEAR WILL BE STRONG...AND SURFACE HEATING COULD CONTRIBUTE TO WEAK TO MODERATE BOUNDARY LAYER DESTABILIZATION. HOWEVER...LOW-LEVEL CONVERGENCE WILL BE WEAK/HIGHLY LOCALIZED...AND MID-LEVEL INHIBITION SUBSTANTIAL...WHICH WILL LIMIT COVERAGE OF STORMS. A RISK FOR A TORNADO WILL EXIST IN ANY STORMS WHICH DO DEVELOP...BUT DAMAGING WIND GUSTS WITH ISOLATED DOWNBURSTS SEEMS LIKELY TO BE PRIMARY SEVERE THREAT. ...EASTERN GREAT BASIN... AS A MID-LEVEL JET STREAK NOSES ACROSS THE SOUTHERN PLATEAU TUESDAY...COOLING/LIFT IN ITS EXIT REGION APPEARS LIKELY TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR CONVECTIVE DEVELOPMENT. MUCH OF THIS ACTIVITY IS EXPECTED TO BE DIURNAL...BUT OCCASIONAL THUNDERSTORMS COULD PERSIST THURSDAY NIGHT NEAR THE FOUR CORNERS...IN CLOSER PROXIMITY TO MID-LEVEL CIRCULATION. ..KERR.. 03/20/2006  From SWODY2 at goshenarc.org Tue Mar 21 17:17:16 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Mar 2006 12:17:16 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060321172002.674BFD4249@mail.goshen.edu> ACUS02 KWNS 211712 SWODY2 SPC AC 211710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST TUE MAR 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD. BUT...IT APPEARS THE LAST IN A SERIES OF SIGNIFICANT SHORT WAVE TROUGHS...ASSOCIATED WITH A BELT OF POLAR WESTERLIES ACROSS THE SOUTHERN TIER STATES...WILL GRADUALLY PROGRESS OUT OF THE SOUTHERN PLATEAU. PROGGED OVER THE FOUR CORNERS STATES AT 12Z WEDNESDAY...THIS FEATURE IS FORECAST TO CROSS THE SOUTHERN ROCKIES...THEN TURN SOUTHEASTWARD INTO THE RED RIVER VALLEY BY EARLY WEDNESDAY EVENING. EVENTUALLY THIS SYSTEM WILL BECOME SHEARED AND ACCELERATE MORE RAPIDLY EASTWARD AS IT CONTINUES INTO AN INCREASINGLY CONFLUENT UPPER FLOW REGIME. THIS COULD OCCUR AS EARLY AS LATE WEDNESDAY NIGHT...BUT APPEARS MORE LIKELY THURSDAY. IN THE WAKE OF A PRIOR IMPULSE...A COLD INTRUSION TO THE LEE OF THE ROCKIES WILL HAVE DRIED/STABILIZED MOST AREAS...INCLUDING THE NORTHERN AND CENTRAL GULF OF MEXICO...BY THE BEGINNING OF THE FORECAST PERIOD. THE UPPER FLOW REGIME WILL MAINTAIN STRONG SURFACE RIDGING THROUGH MUCH OF EASTERN NORTH AMERICA...AND THE POTENTIAL FOR EVEN A WEAK RETURN FLOW OF GULF MOISTURE ABOVE THIS STABLE LAYER LOOKS TO BE MINIMAL. THIS WILL PRECLUDE ANY RISK FOR VIGOROUS THUNDERSTORM ACTIVITY. ...SOUTH CENTRAL STATES... MODELS DO SUGGEST A ZONE OF LOWER/MID TROPOSPHERIC WARM ADVECTION AND MOISTENING ASSOCIATED WITH THE SUBTROPICAL STREAM WILL OVERSPREAD PARTS OF SOUTHEAST TEXAS INTO CENTRAL GULF COASTAL AREAS BY WEDNESDAY AFTERNOON. THIS WILL OCCUR IN ADVANCE OF SOUTHERN BRANCH TROUGH SHIFTING TO THE LEE OF THE SOUTHERN ROCKIES...BUT DOWNSTREAM HEIGHT FALLS ASSOCIATED WITH THIS FEATURE MAY CONTRIBUTE TO WEAKENING MID/UPPER LEVEL INHIBITION AND CONVECTIVE DEVELOPMENT. MODEL FORECAST SOUNDINGS SUGGEST ENOUGH CAPE COULD DEVELOP IN MOIST LAYER BASED AROUND 700 MB...THROUGH FAVORABLE MIXED PHASE LAYER... FOR WEAK THUNDERSTORM ACTIVITY. ..KERR.. 03/21/2006  From SWODY2 at goshenarc.org Wed Mar 22 17:07:21 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Mar 2006 12:07:21 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060322171003.C4A26D473F@mail.goshen.edu> ACUS02 KWNS 221707 SWODY2 SPC AC 221706 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 AM CST WED MAR 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD AND BEYOND. BUT...A STRONG BELT OF POLAR WESTERLIES...WHICH HAS TRAVERSED THE SOUTHERN TIER OF THE U.S...IS PROGGED TO FINALLY BEGIN SHIFTING EAST OF THE SOUTHEAST STATES. THE LAST IN A SERIES OF SIGNIFICANT SHORT WAVE IMPULSES ASSOCIATED WITH THIS FEATURE IS FORECAST TO ACCELERATE INTO CONFLUENT REGIME ACROSS THE CENTRAL/EASTERN GULF STATES... BECOMING INCREASINGLY SHEARED AS IT APPROACHES SOUTH ATLANTIC COASTAL AREAS BY 12Z FRIDAY. FORCING ASSOCIATED WITH UPPER IMPULSE IS EXPECTED TO SUPPORT WEAK WAVE DEVELOPMENT ALONG SURFACE FRONT NOW STALLING NEAR SOUTHERN FLORIDA COASTAL AREAS AND THE KEYS. IN ITS WAKE...LARGE COLD SURFACE RIDGE...ENCOMPASSING MUCH OF EASTERN NORTH AMERICA...IS PROGGED TO NOSE THROUGH THE REMAINDER OF THE GULF OF MEXICO/THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE. THIS WILL SIGNIFICANTLY MINIMIZE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION THROUGH THURSDAY/THURSDAY NIGHT...AND THE DAYS TO FOLLOW. ...FLORIDA... MID-LEVEL HEIGHT FALLS AND FORCING ASSOCIATED WITH DEVELOPING SURFACE WAVE SHOULD BECOME SUPPORTIVE OF THUNDERSTORM ACTIVITY THURSDAY. MUCH OF THIS LIKELY WILL OCCUR OFFSHORE...BUT MODELS SUGGEST SOME POTENTIAL FOR INLAND DEVELOPMENT...WITH PROBABILITIES INCREASING TOWARD SOUTHEAST COASTAL AREAS. ...PACIFIC NORTHWEST... LARGE...COLD MID-LEVEL LOW OVER THE NORTHEAST PACIFIC IS EXPECTED TO MOVE LITTLE THROUGH EARLY FRIDAY. THUS...POTENTIAL FOR DEEP CONVECTIVE DEVELOPMENT INLAND OF COASTAL AREAS DURING THIS PERIOD APPEARS MINIMAL. HOWEVER...IMPULSES ROTATING AROUND THE CIRCULATION CENTER MAY MAINTAIN A RISK OF SCATTERED THUNDERSTORM ACTIVITY NEAR OFFSHORE WATERS. ..KERR.. 03/22/2006  From SWODY2 at goshenarc.org Thu Mar 23 17:12:35 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Mar 2006 12:12:35 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060323171514.945B4D4989@mail.goshen.edu> ACUS02 KWNS 231712 SWODY2 SPC AC 231711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CST THU MAR 23 2006 VALID 241200Z - 251200Z ...NO SVR TSTM AREAS FORECAST... THE BULK OF A STRONGER BELT OF WESTERLIES HAS SHIFTED OUT ACROSS THE ATLANTIC...AND THE LAST IN A SERIES OF ASSOCIATED SHORT WAVE TROUGHS ASSOCIATED WITH THIS FEATURE IS FORECAST TO PROGRESS EAST OF THE SOUTH ATLANTIC COAST BY MID DAY FRIDAY. IN ITS WAKE... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST... WITH AN UPPER HIGH REMAINING CENTERED OVER THE NORTH CENTRAL CANADIAN PROVINCES...WHILE CLOSED LOWS LINGER OVER THE NORTHEAST PACIFIC AND OHIO VALLEY. UPPER FLOW REGIME WILL CONTINUE TO SUPPORT A LARGE COLD SURFACE RIDGE ACROSS MUCH OF EASTERN NORTH AMERICA THROUGH THE WESTERN GULF OF MEXICO/BAY OF CAMPECHE AND YUCATAN PENINSULA. SOUTHERN PORTION OF THIS RIDGE MAY BEGIN TO WEAKEN IN RESPONSE TO SHORT WAVE TROUGH PROGRESSING THROUGH RELATIVELY WEAK BELT OF SUBTROPICAL WESTERLIES ACROSS THE MEXICAN PLATEAU. HOWEVER... EFFECTS OF SURFACE RIDGE WILL MINIMIZE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION EAST OF THE ROCKIES THROUGH THIS PERIOD AND BEYOND. MODELS DO SUGGEST A MORE PROGRESSIVE UPPER FLOW MAY BEGIN TO DEVELOP FRIDAY ACROSS THE NORTH CENTRAL/NORTHEAST PACIFIC INTO THE NORTHERN PACIFIC COAST STATES. IN RESPONSE TO AN UPSTREAM IMPULSE DIGGING TO THE SOUTH/EAST OF THE ALEUTIANS...A VIGOROUS SHORT WAVE TROUGH...CURRENTLY EMBEDDED WITHIN BROADER CIRCULATION OVER THE NORTHEAST PACIFIC...IS PROGGED TO APPROACH THE NORTH CENTRAL PACIFIC COAST. THIS PROBABLY WILL NOT OCCUR UNTIL LATE FRIDAY NIGHT/EARLY SATURDAY...BUT MODELS SUGGEST TROUGH WILL BE PRECEDED INLAND...ACROSS WASHINGTON/OREGON...BY A WEAKER IMPULSE. ...PACIFIC NORTHWEST COAST STATES... MID-LEVEL COOLING ASSOCIATED WITH THE LEAD IMPULSE IS EXPECTED TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR SCATTERED AFTERNOON THUNDERSTORMS...MAINLY ACROSS COASTAL AND INTERIOR SECTIONS OF WASHINGTON/OREGON. WEAK INSTABILITY WILL LIMIT STRENGTH OF UPDRAFTS...BUT THERMODYNAMIC ENVIRONMENT COULD BE SUFFICIENT FOR SOME SMALL HAIL OR GRAUPEL REACHING THE SURFACE IN STRONGER CELLS. MOST STORMS LIKELY WILL DIMINISH AFTER DARK FRIDAY EVENING...BUT A FEW STORMS MAY APPROACH SOUTHERN OREGON/NORTHERN CALIFORNIA COASTAL AREAS WITH STRONGER FORCING LATE FRIDAY NIGHT/EARLY SATURDAY. ..KERR.. 03/23/2006  From SWODY2 at goshenarc.org Fri Mar 24 05:52:54 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Mar 2006 00:52:54 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060324055528.8F199D4478@mail.goshen.edu> ACUS02 KWNS 240553 SWODY2 SPC AC 240552 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1152 PM CST THU MAR 23 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SYNOPTIC PATTERN WILL FEATURE TROUGHING OVER ERN AND WRN CONUS...WITH MEAN RIDGE FROM SRN ROCKIES NWD ACROSS CANADIAN PRAIRIES. UPPER LOW NOW OVER ERN GREAT LAKES REGION IS EXPECTED TO PIVOT SEWD THEN EWD OFFSHORE CAROLINAS/MID-ATLANTIC REGION LATE IN PERIOD. MEANWHILE...SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AROUND 45N148W -- IS FCST TO MOVE THROUGH BASE OF NERN PACIFIC UPPER LOW...AMPLIFY CONSIDERABLY...THEN MOVE ASHORE CA COAST AROUND 25/18Z. ALTHOUGH MINOR DISCREPANCIES EXIST WITH TIMING/AMPLITUDE OF PACIFIC TROUGH...GENERAL SCENARIO IS STRONGLY AGREED UPON BY LATEST OPERATIONAL MODELS AND SREFX MEMBERS. THIS TROUGH THEN SHOULD MOVE EWD ACROSS SIERRA NV RANGE AND WRN GREAT BASIN...REACHING LONGITUDE OF UT AND WRN MT BY END OF PERIOD. ASSOCIATED LOW LEVEL FRONTAL ZONE IS EXPECTED TO MOVE EWD ACROSS GREAT BASIN THROUGH PERIOD...PROVIDING PRIMARY FOCUS FOR STRONG-SEVERE TSTM POTENTIAL. ...GREAT BASIN... SCATTERED TSTMS ARE POSSIBLE ALONG BAROCLINICALLY FORCED BAND...AMIDST STRONG SFC-700 MB FRONTOGENETIC FORCING. ACTIVITY SHOULD SHIFT EWD TO NEWD ACROSS REGION...WITH GREATEST INTENSITY/COVERAGE EXPECTED DURING MID AFTERNOON TO EARLY EVENING. SOME TSTMS MAY BECOME ORGANIZED ENOUGH TO PRODUCE DAMAGING WIND. AFTERNOON HEATING...AT LEAST MRGL BOUNDARY LAYER MOISTURE...AND FAVORABLY STEEPENING MIDLEVEL LAPSE RATES...SHOULD DESTABILIZE AIR MASS OVER ERN NV AND WRN UT...PERHAPS INTO PORTIONS SRN ID. CLOUD COVER MAY LIMIT HEATING IN SOME AREAS...HOWEVER WEAK CINH...FRONTAL FORCING AND LARGE SCALE DESTABILIZATION SHOULD SUPPORT CONVECTIVE POTENTIAL. MEANWHILE...STRENGTHENING DEEP-LAYER VERTICAL SHEAR IS EXPECTED AS MIDLEVEL TROUGH APCHS...TIGHTENING HEIGHT/PRESSURE GRADIENTS THROUGH MUCH OF TROPOSPHERE. ACTIVITY SHOULD DIMINISH AFTER DARK AS SFC HEATING AND RELATED BUOYANCY DIMINISH...AND MAIN BAND OF FORCING MOVES INTO HIGHER TERRAIN OF NRN UT/SERN ID. ..EDWARDS.. 03/24/2006  From SWODY2 at goshenarc.org Fri Mar 24 17:26:43 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Mar 2006 12:26:43 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060324173129.C3549D4A83@mail.goshen.edu> ACUS02 KWNS 241727 SWODY2 SPC AC 241726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST FRI MAR 24 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... BLOCKING IN THE LARGE-SCALE UPPER FLOW PATTERN ACROSS MUCH OF NORTH AMERICA PERSISTS. BUT...MODELS SEEM TO SUGGEST THAT AS A STRONG UPPER JET NOSES INTO THE WESTERN PACIFIC...REGIME MAY BECOME AT LEAST A BIT MORE PROGRESSIVE IN SPLIT BELTS OF STRONGER FLOW ACROSS THE CENTRAL/EASTERN PACIFIC. THIS INCLUDES A SIGNIFICANT SHORT WAVE TROUGH WHICH IS PROGGED TO DIG WELL SOUTH OF THE ALEUTIANS LATER TODAY THROUGH SATURDAY...FORCING ANOTHER VIGOROUS SHORT WAVE INLAND ACROSS THE NORTH CENTRAL PACIFIC COAST. THE LEAD IMPULSE IS CURRENTLY EMBEDDED WITHIN...AND ROTATING AROUND...THE SOUTHERN PERIPHERY OF A BROADER SCALE NORTHEAST PACIFIC CIRCULATION. THIS FEATURE IS FORECAST TO BECOME DETACHED FROM THE CIRCULATION BY 12Z SATURDAY...BEFORE ACCELERATING INLAND ACROSS OREGON/NORTHERN CALIFORNIA...AND THROUGH THE GREAT BASIN...BY 12Z SUNDAY. FARTHER DOWNSTREAM...UPPER FLOW WILL REMAIN CONFLUENT EAST OF THE ROCKIES INTO BROADER SCALE TROUGHING TO THE SOUTH OF OHIO VALLEY CLOSED LOW. THIS WILL MAINTAIN SURFACE RIDGING OVER MUCH OF EASTERN NORTH AMERICA THROUGH THE GULF OF MEXICO/BAY OF CAMPECHE/ AND THE CARIBBEAN. ...WESTERN STATES... MID-LEVEL COOLING AND FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED WITH SHORT WAVE TROUGH WILL CONTRIBUTE TO WEAK DESTABILIZATION AND CONVECTIVE DEVELOPMENT SATURDAY. THIS WILL INCLUDE THE POTENTIAL FOR SCATTERED THUNDERSTORMS OVER A FAIRLY BROAD AREA WEST OF THE ROCKIES. COLD CORE OF SYSTEM /500 MB TEMPS AS LOW AS -30C/ IS PROGGED TO OVERSPREAD THE SOUTHERN CASCADES/NORTHERN SIERRA AND SACRAMENTO VALLEY DURING THE PEAK AFTERNOON HEATING. THIS COULD CONTRIBUTE TO MIXED LAYER CAPE UP TO 500 J/KG...MAINLY IN THE LOWER/MORE MOIST SACRAMENTO VALLEY...WHERE OROGRAPHY MAY CONTRIBUTE TO SOUTHEASTERLY LOW-LEVEL FLOW IN WAKE OF SURFACE COLD FRONT. BENEATH STRONG CYCLONIC MID-LEVEL FLOW...THIS WILL PROVIDE FAVORABLE SHEAR FOR THE POSSIBILITY OF A LOW TOPPED SUPERCELL OR TWO...ALONG WITH ASSOCIATED RISK OF A TORNADO OR PERHAPS SOME MARGINALLY SEVERE HAIL. UNCERTAINTY EXISTS CONCERNING EXTENT OF CLOUD COVER ACROSS THE GREAT BASIN SATURDAY...WHICH COULD LIMIT MAGNITUDE OF SURFACE HEATING AND DESTABILIZATION. HOWEVER...FORCING/SHEAR SEEM LIKELY TO INCREASE ALONG SURFACE COLD FRONT FROM PARTS OF SOUTHERN IDAHO THROUGH CENTRAL NEVADA BY LATE AFTERNOON. THIS MAY BECOME SUPPORTIVE OF A DEVELOPING CONVECTIVE LINE ACCOMPANIED BY STRONG GUSTY WINDS...EVEN IN ABSENCE OF MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. ACTIVITY WILL SPREAD INTO PARTS OF THE EASTERN GREAT BASIN BEFORE DIMINISHING SATURDAY EVENING. ..KERR.. 03/24/2006  From SWODY2 at goshenarc.org Sat Mar 25 05:43:01 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Mar 2006 00:43:01 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060325054531.2B559D45E0@mail.goshen.edu> ACUS02 KWNS 250543 SWODY2 SPC AC 250541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST FRI MAR 24 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE SHORTWAVE PATTERN ACROSS CONUS WILL FEATURE STRONG TROUGH NOW EXHIBITING UPPER LEVEL CIRCULATION CENTER INVOF 41N134W...BASED ON MOISTURE CHANNEL IMAGERY. PERTURBATION IS FCST TO MOVE ACROSS COASTAL CA/ORE AND GREAT BASIN DAY-1...THEN FROM CENTRAL/NRN ROCKIES EWD ACROSS CENTRAL/NRN PLAINS THROUGH THIS PERIOD. MOST OPERATIONAL MODELS AND SREFX MEMBERS FCST CLOSED MIDLEVEL LOW BETWEEN JMS-OFK BY 27/12Z...ABOUT 100 NM W OF RELATED SFC CYCLONE. SFC COLD FRONT WILL REFORM WITHIN LEE TROUGHING AREA JUST E OF ROCKIES EARLY IN PERIOD...THEN MOVE SEWD ACROSS CENTRAL PLAINS AND SRN HIGH PLAINS BY 27/12Z. LARGE SCALE FORCING...IN FORM OF STRONG DPVA OVER NRN ROCKIES AND STRONG WAA OVER E-CENTRAL PLAINS AND LOWER MO VALLEY REGION...WILL CONTRIBUTE TO TWO MARGINAL GEN THUNDER OUTLOOKS. ...N-CENTRAL ROCKIES... ALTHOUGH LIMITED LOW-MIDDLE LEVEL MOISTURE WILL RESTRICT BUOYANCY...PRIND STEEP MIDLEVEL LAPSE RATES AND STRONG FRONTOGENETIC FORCING/LIFT WILL CONTRIBUTE TO OCCASIONAL SHORT-LIVED TSTMS. ACTIVITY SHOULD BE BASED WELL ABOVE SFC IN REGIME OF STRONGEST THERMAL COOLING ALOFT...WITH MUCAPES GENERALLY AOB 200 J/KG. ...E-CENTRAL PLAINS...OZARKS TO SRN IA... ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE AFTER ABOUT 27/06Z AMIDST STRONG LOW LEVEL WAA REGIME...COMBINED WITH MARGINAL MOISTURE EMANATING FROM RETURN FLOW TRAJECTORIES THAT HAVE BEEN ONLY WEAKLY MODIFIED FROM THEIR CONTINENTAL/POLAR ORIGINS. FCST SOUNDINGS FROM OPERATIONAL ETA...ETA-KF...AND NAM A.K.A. WRF...EACH INDICATE SUFFICIENT UVV/MOISTENING TO SATURATE PORTIONS 700-850 MB LAYER ABOVE STRONGEST CINH. PRIND PARCELS WILL BE ISENTROPICALLY LIFTED TO LFC W OF 45-55 KT SWLY LLJ THAT SHOULD EXTEND FROM N-CENTRAL TX TO E-CENTRAL MO BY 12Z. SEVERE POTENTIAL WILL BE GREATLY INHIBITED BY LACK OF MORE ROBUST MOISTURE...WITH ELEVATED MUCAPES LIKELY TO REMAIN UNDER 300 J/KG IN MOST AREAS. ..EDWARDS.. 03/25/2006  From SWODY2 at goshenarc.org Sat Mar 25 16:53:58 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Mar 2006 11:53:58 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060325165631.85269D46F5@mail.goshen.edu> ACUS02 KWNS 251654 SWODY2 SPC AC 251653 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1053 AM CST SAT MAR 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT-WAVE UPPER TROUGH MOVING ACROSS THE CENTRAL/NRN ROCKIES AT THE START OF THE PERIOD SHOULD REACH THE CENTRAL/NRN HIGH PLAINS BY LATE AFTERNOON...AND THEN CONTINUE EWD INTO THE MIDDLE MO VALLEY REGION BY THE END OF THE PERIOD. AHEAD OF THIS FEATURE...SURFACE LEE TROUGH WILL MOVE EWD INTO/ACROSS THE PLAINS THROUGH 27/12Z. ...ERN HALF OF WY AND VICINITY... COOL AIR ALOFT /-26 TO -28 C AT H5/ ASSOCIATED WITH UPPER TROUGH COMBINED WITH DAYTIME HEATING OVER THE HIGHER TERRAIN MAY YIELD MINIMAL INSTABILITY BY AFTERNOON. A FEW WEAK/HIGH-BASED STORMS ARE EXPECTED -- MAINLY OVER THE ERN HALF OF WY...BEFORE TROUGH SHIFTS EWD INTO THE PLAINS. ...KS/NRN OK EWD INTO WRN MO... LOW-LEVEL THETA-E ADVECTION AHEAD OF APPROACHING UPPER SYSTEM MAY RESULT IN SUFFICIENT MOISTENING TO ALLOW MINIMAL ELEVATED INSTABILITY TO DEVELOP BY EVENING. THUS...A LIMITED POTENTIAL FOR SCATTERED TO ISOLATED/WEAK THUNDERSTORM DEVELOPMENT APPEARS TO EXIST ACROSS PARTS OF KS/WRN MO AND VICINITY...MAINLY AFTER 27/00Z. ..GOSS.. 03/25/2006  From SWODY2 at goshenarc.org Sun Mar 26 05:41:52 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Mar 2006 00:41:52 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060326054416.E64F4D4989@mail.goshen.edu> ACUS02 KWNS 260542 SWODY2 SPC AC 260541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SAT MAR 25 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE MIDDLE-UPPER LEVEL PATTERN FCST THROUGH DAY-2...FEATURING STRONG SHORTWAVE TROUGH NOW MOVING EWD ACROSS NV...SERN ORE...AND SWRN ID. THIS FEATURE IS FCST TO MOVE EWD FROM NRN PLAINS ACROSS UPPER MS VALLEY AND OVER WI BY 28/12Z. ASSOCIATED SFC CYCLONE SHOULD BE NEARLY COLLOCATED BY 28/00Z-28/12Z TIME FRAME. SFC COLD FRONT WILL MOVE EWD ACROSS MO...SEWD ACROSS OK AND PORTIONS AR...AND SWD ACROSS RED RIVER REGION TOWARD PORTIONS N-CENTRAL/W-CENTRAL TX. ...CENTRAL/S TX... SCATTERED TO WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP DURING AFTERNOON/EVENING INVOF SFC COLD FRONT...AND PERHAPS ALONG DEVELOPING SW TX DRYLINE AND/OR HIGHER TERRAIN OF COAHUILA. ADDITIONAL CONVECTION IS POSSIBLE ALONG AND N OF SFC FRONT AFTER DARK...AMIDST STRENGTHENING LLJ AND WAA REGIME. CONTINENTAL/POLAR TRAJECTORIES NOW CROSSING PORTIONS NRN/CENTRAL GULF ARE EXPECTED TO RETURN NWWD ACROSS REGION IN INCOMPLETELY MODIFIED FORM...WITH MAINLY 50S F SFC DEW POINTS AND A FEW LOW 60S POSSIBLE OVER S TX. DIURNAL HEATING MAY BE LIMITED BY DENSE STRATOCUMULUS COVER WITHIN RETURN FLOW REGIME FOR MUCH OF THE DAY...THOUGH AFTERNOON BREAKS INVOF FRONTAL ZONE MAY HELP TO BOOST MLCAPES TO NEAR 1000 J/KG. WEAK LOW LEVEL FLOW DURING DAY WILL LIMIT HODOGRAPH SIZE...THOUGH STRONG DIRECTIONAL VEERING AND 30-40 KT DEEP-LAYER SHEAR INDICATE POTENTIAL FOR SOME ACTIVITY TO BECOME ORGANIZED WITH HAIL AND GUSTS NEAR SEVERE LEVELS. AFTER DARK...ACTIVITY ALONG AND N OF FRONT SHOULD BECOME SCATTERED-NUMEROUS IN COVERAGE...IN ONE OR MORE CLUSTERS OVER CENTRAL/NRN TX. WHILE THIS CONVECTION MAY PRODUCE HAIL...MAIN THREAT MAY BE HEAVY RAINFALL PER LATEST HPC QPF DISCUSSION. ALTHOUGH SEVERAL ENSEMBLE MEMBERS AND OPERATIONAL MODELS DEVELOP CONVECTION ACROSS PORTIONS S-CENTRAL TX BEFORE 28/00Z...PRIND THIS AIR MASS WILL REMAIN CAPPED DIURNALLY BY STRONG ELEVATED MIXED LAYER GENERATED DURING PRECEDING DAYS OF WLY/SWLY FLOW ALOFT. ISOLATED TSTMS MAY MOVE EWD ACROSS RIO GRANDE FROM OROGRAPHICALLY FORCED ASCENT ZONE IN SERRANIAS DEL BURRO RANGE. ..EDWARDS.. 03/26/2006  From SWODY2 at goshenarc.org Sun Mar 26 17:38:23 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Mar 2006 12:38:23 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060326174046.38415D46DE@mail.goshen.edu> ACUS02 KWNS 261739 SWODY2 SPC AC 261737 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CST SUN MAR 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW/SHORT-WAVE TROUGH INITIALLY OVER THE CENTRAL PLAINS IS FORECAST TO CONTINUE EWD ACROSS THE MIDWEST/OH VALLEY THROUGH THE END OF THE PERIOD. ASSOCIATED SURFACE LOW WILL ALSO MOVE EWD ACROSS THIS REGION...ACCOMPANIED BY WEAKENING COLD FRONT. FARTHER S/SW...A WEAK SRN-STREAM TROUGH IS FORECAST TO MOVE ACROSS NWRN MEXICO TOWARD TX DURING THE AFTERNOON. ...PARTS OF THE TRANSPECOS REGION/RIO GRANDE VALLEY/CENTRAL TX... MARGINAL DESTABILIZATION IS FORECAST ACROSS PARTS OF TX AHEAD OF SRN STREAM TROUGH...AS DAYTIME HEATING COMBINES WITH PARTIALLY-MODIFIED GULF MOISTURE RETURN TO YIELD 500 TO 1000 J/KG MEAN-LAYER CAPE. THOUGH CAP SHOULD HINDER CONVECTION ACROSS DEEP S TX...SCATTERED TO ISOLATED STORMS MAY DEVELOP ACROSS PARTS OF THE TRANSPECOS REGION AND INTO CENTRAL TX/THE HILL COUNTRY IN WEAK AXIS OF SURFACE CONVERGENCE ALONG FRONTOLYTIC BOUNDARY. THOUGH ONLY A SMALL/FAIRLY WEAK MID-LEVEL JET /30 TO 35 KT/ WILL ACCOMPANY THE SRN-STREAM FEATURE...AMPLE DIRECTIONAL SHEAR COULD SUPPORT A FEW STRONGER UPDRAFTS WITH MID-LEVEL ROTATION. THEREFORE...A LIMITED HAIL/WIND THREAT MAY EXIST -- PARTICULARLY THROUGH THE AFTERNOON. OVERNIGHT...LOW-LEVEL WARM ADVECTION N OF WEAKENING BOUNDARY MAY SUPPORT AN INCREASE IN STORM COVERAGE...THOUGH LIMITED INSTABILITY SHOULD PRECLUDE ANY MORE THAN A VERY MARGINAL HAIL THREAT. ..GOSS.. 03/26/2006  From SWODY2 at goshenarc.org Fri Mar 31 06:24:51 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 31 Mar 2006 01:24:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 310625 SWODY2 SPC AC 310624 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 AM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHWEST TEXAS....WESTERN OKLAHOMA...AND SOUTHERN KANSAS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM TX TO SERN NEB...SWRN IA...AND WRN PARTS OF MO AND AR... ...POTENTIAL EXISTS FOR NUMEROUS SEVERE STORMS WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES ACROSS PORTIONS OF THE SOUTHERN PLAINS ON SATURDAY... ...SYNOPSIS... ACTIVE FLOW REGIME CONTINUES INTO THE WEEKEND AS ANOTHER ROUND OF STRONG HEIGHT FALLS CROSS THE ROCKIES AND EMERGE OVER THE HIGH PLAINS ON SATURDAY...AHEAD OF PROGRESSIVE TROUGH CURRENTLY MOVING ONTO THE WEST COAST. DOWNSTREAM FROM THIS NEXT TROUGH...A VIGOROUS MID/UPPER LEVEL IMPULSE...NOW MOVING TOWARD THE UPPER MS VALLEY... WILL MOVE FROM THE ERN GREAT LAKES TOWARD THE CANADIAN MARITIME PROVINCES THROUGH THE DAY 2 PERIOD. SURFACE COLD FRONT ASSOCIATED WITH THE ERN SYSTEM SHOULD MOVE QUICKLY EAST ACROSS THE MID-ATLANTIC AND NEW ENGLAND REGIONS THROUGH SATURDAY AFTERNOON. THE TRAILING PORTION OF THE FRONTAL ZONE WILL EXTEND WWD FROM THE TN VALLEY TO THE ARKLATEX EARLY IN THE DAY 2 PERIOD. AS NEXT TROUGH APPROACHES THE PLAINS AND DEEP LAYER SLY FLOW INCREASES OVER THE REGION...EXPECT WARM FRONT TO LIFT NWD ACROSS OK/KS DURING THE DAY AS LEE-SIDE SURFACE CYCLOGENESIS COMMENCES OVER SRN CO. AS THIS OCCURS...DRYLINE SHOULD DEVELOP EAST FROM WRN PORTIONS KS/OK/TX INTO RICH BOUNDARY LAYER MOISTURE SPREADING NWD ACROSS THE PLAINS. LATEST GUIDANCE INDICATES THAT SURFACE LOW TRACKS ENEWD ALONG WARM FRONT OVER NRN KS THROUGH LATE SATURDAY NIGHT/SUNDAY MORNING AS STRONG DRYLINE DEVELOPS EAST INTO MOIST AND UNSTABLE WARM SECTOR FROM NWRN TX TO CNTRL OK/KS. ...SRN/CNTRL PLAINS... FORECAST SCENARIO APPEARS TO HAVE CHANGED LITTLE FROM EARLIER DAY 3 OUTLOOK...A CLASSIC SPRINGTIME WARM FRONT/DRYLINE SCENARIO IS INDICATED OVER THE PLAINS ON SATURDAY AFTERNOON. MODELS CONTINUE TO SUGGEST THE POTENTIAL FOR ISOLATED CONVECTION EARLY IN THE DAY ALONG DEVELOPING WARM FRONT ACROSS THE RED RIVER VALLEY...PERHAPS SUPPORTED BY WEAK LLJ DIRECTED INTO THE FRONTAL ZONE. AS WARM SECTOR EXPANDS NWD ACROSS THE REGION DURING THE DAY IT APPEARS THAT LOW TO MID 60S F DEWPOINTS AND RELATIVELY COOL TEMPERATURES ALOFT WILL CONTRIBUTE TO MLCAPE VALUES APPROACHING 2000 J/KG IN AN AXIS FROM NWRN TX ACROSS WRN OK AND INTO PARTS OF SWRN/SCNTRL KS BY AFTERNOON. WEAK TO MODEST CAPPING IS INDICATED IN BOTH NAMKF AND NAM-WRF SOUNDINGS ACROSS THIS INSTABILITY AXIS THROUGH THE AFTERNOON BUT ALL RECENT GUIDANCE INDICATES VIGOROUS CONVECTIVE INITIATION NEAR THE DRYLINE AND WARM FRONT DURING THE 01/21Z-02/00Z TIME FRAME. THIS APPEARS REASONABLE GIVEN OVERALL PATTERN AND ANTICIPATED HEATING/FORCING ALONG THE BOUNDARIES. EXPECT STORMS TO ERUPT WITHIN A KINEMATIC ENVIRONMENT EXTREMELY SUPPORTIVE OF SUPERCELLS WITH WEAK TO MODEST LOW LEVEL SSELY FLOW TOPPED BY INCREASINGLY STRONG SWLY FLOW ALOFT. FURTHERMORE... CONVECTION IS EXPECTED TO MOVE INTO STRONGER LOW LEVEL SHEAR NEAR THE WARM FRONT OVER SCNTRL KS/NWRN OK. TORNADOES...AND VERY LARGE HAIL AND HIGH WINDS COULD OCCUR WITH THIS ACTIVITY. FARTHER SOUTH...FROM NWRN OK INTO NWRN TX...SOMEWHAT WEAKER LARGE SCALE FORCING AND LOW LEVEL SHEAR MAY BE OFFSET BY GREATER INSTABILITY TO SUPPORT AT LEAST ISOLATED SUPERCELLS AHEAD OF THE DRYLINE WITH ATTENDANT THREATS OF TORNADOES AND VERY LARGE HAIL. A CLUSTER OR TWO OF SEVERE STORMS SHOULD EVOLVE THROUGH THE EVENING ACROSS PORTIONS OF OK/KS WITH ACTIVITY BEING SUSTAINED BY STRONG FORCING AND SHEAR NEAR THE SURFACE LOW AND WARM FRONT. THIS ACTIVITY WILL MOVE TOWARD THE MO VALLEY THROUGH LATE SATURDAY NIGHT...POSSIBLY BECOMING MORE ELEVATED WITH TIME BUT STILL POSING AT LEAST A HAIL THREAT AS FAR AS SWRN IA AND WRN MO INTO EARLY SUNDAY. ...NORTHEAST... STRONG COLD FRONT WILL SWEEP EAST FROM THE ERN GREAT LAKES EARLY IN THE DAY...AND ACROSS NEW ENGLAND THROUGH THE AFTERNOON. MARGINAL HEATING AND LOW TO MID 50S F DEWPOINTS AHEAD OF THE FRONT MAY RESULT IN MLCAPE VALUES OF UP TO 500 J/KG OVER PORTIONS OF THE MID HUDSON VALLEY...WITH WEAKER INSTABILITY NORTH AND EAST OF THIS AREA. FORCING APPEARS SUFFICIENT TO MAINTAIN A LINE OF LOW-TOPPED STORMS ON THE ADVANCING FRONT WITH UNIDIRECTIONAL SHEAR PROFILES FURTHER SUPPORTING UPDRAFT PERSISTENCE. RESULTING STORM MOTION AND AMBIENT FLOW SUGGEST WIND GUSTS WITH THE LINE OF STORMS MAY BE IN THE RANGE OF 40-50KT. IF GREATER INSTABILITY CAN DEVELOP THAN CURRENTLY ANTICIPATED...A SMALL SLGT RISK AREA MAY BE WARRANTED IN LATER OUTLOOKS. ..CARBIN.. 03/31/2006  From SWODY2 at goshenarc.org Fri Mar 31 17:27:29 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 31 Mar 2006 12:27:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 311728 SWODY2 SPC AC 311727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF SWRN KS...THE TX PNHDL...WRN OK AND NWRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY SWD INTO THE CNTRL AND SRN PLAINS...AND EWD INTO THE MID SOUTH... ...SYNOPSIS... PROGRESSIVE LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID AND UPPER-LEVEL TROUGH WHICH WILL MOVE FROM THE INTERMOUNTAIN W INTO THE GREAT PLAINS. DOWNSTREAM TROUGH NOW OVER THE UPPER MIDWEST WILL SHIFT EWD THROUGH THE NERN STATES. IN THE LOW-LEVELS...LEE CYCLOGENESIS IS FORECAST OVER THE NRN AND CNTRL HIGH PLAINS WITH THE PRIMARY SURFACE LOW EVENTUALLY CONSOLIDATING OVER ERN CO/WRN KS. DRY LINE WILL SHARPEN THROUGH THE DAY...LIKELY EXTENDING FROM WRN KS SWD INTO THE ERN TX PNHDL AND W-CNTRL TX BY LATE SATURDAY AFTERNOON. MEANWHILE...BAROCLINIC ZONE INITIALLY STALLED FROM THE MID S WWD TO ALONG THE RED RIVER VALLEY WILL RETREAT NWD THROUGH THE PERIOD AS SURFACE LOW DEEPENS OVER ERN CO. IN THE E...LOW PRESSURE WILL DEVELOP NEWD ACROSS SRN QUEBEC WHILE TRAILING COLD FRONT PUSHES EWD THROUGH THE HUDSON VALLEY...NEW ENGLAND AND MIDDLE ATLANTIC COASTAL PLAIN. ...CNTRL/SRN PLAINS INTO MID SOUTH... A POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE IS FORECAST SATURDAY AFTERNOON AND EVENING OVER PORTIONS OF SWRN KS...THE ERN TX PNHDL...WRN OK AND NWRN TX. HOWEVER...CAVEATS DO EXIST WHICH COULD AFFECT THE AMOUNT OF DESTABILIZATION THAT OCCURS E OF DRY LINE. THESE INCLUDE: 1) INFLUENCE OF WEAKER LEAD DISTURBANCES ON OVERNIGHT AND MORNING CONVECTION WHICH COULD DISRUPT WARM SECTOR...2) INCREASING MID AND HIGH CLOUDINESS...AND 3) QUALITY OF BOUNDARY-LAYER MOISTURE. ISOLATED TO SCATTERED TSTMS ARE EXPECTED TO BE ONGOING SATURDAY MORNING ALONG AND N OF STATIONARY BOUNDARY FROM PORTIONS OF MS/AL WWD ACROSS AR AND OK WITHIN PERSISTENT LOW-LEVEL WAA PATTERN. SOME OF THIS ACTIVITY WILL LIKELY PERSIST THROUGH DAY...WITH THE POTENTIAL FOR SEVERE WEATHER INCREASING BY AFTERNOON FROM THE MID SOUTH INTO ERN OK AS MOIST BOUNDARY-LAYER CONDITIONS CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF 1500-2500 J/KG. DESPITE SOME RELATIVE WEAKNESS IN MID AND HIGH-LEVEL WIND FIELDS...PRONOUNCED VEERING WITH HEIGHT COUPLED WITH THE MODERATE INSTABILITY AND RELATIVELY STEEP LAPSE RATES SUGGEST THE POTENTIAL FOR ORGANIZED/ROTATING UPDRAFTS CAPABLE OF DAMAGING WINDS...LARGE HAIL AND PERHAPS A COUPLE OF TORNADOES. MORE SIGNIFICANT SEVERE TSTM DEVELOPMENT IS ANTICIPATED BY MID TO LATE AFTERNOON FROM WARM FRONT/DRY LINE TRIPLE POINT SWD ALONG DRY LINE FROM WRN KS INTO THE TX PNHDL AND WRN OK. HERE...STEEP MID-LEVEL LAPSE RATES AND INCREASING BOUNDARY-LAYER MOISTURE ARE EXPECTED TO RESULT IN A MODERATELY UNSTABLE AIR MASS /MLCAPES 1500-2500 J/KG/. AS MENTIONED ABOVE...POSSIBLE INCREASE IN HIGH CLOUDS...ANY ONGOING STORMS ASSOCIATED WITH LEAD DISTURBANCES...ALONG WITH MIXING OF SHALLOW MOIST PROFILES COULD POTENTIALLY LIMIT THIS INSTABILITY. TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY WITHIN THIS CORRIDOR BETWEEN 21-00Z AS DRY LINE CIRCULATION STRENGTHENS AND DEEPENS AND WEAK HEIGHT FALLS AHEAD OF MID-LEVEL TROUGH SPREAD EWD INTO THE HIGH PLAINS. FORECAST SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF VERY LARGE HAIL AND TORNADOES. IN THIS TYPE OF PATTERN...POTENTIAL WILL EXIST FOR A FEW STRONG TORNADOES...ESPECIALLY BETWEEN 23-03Z WITH ANY SUPERCELLS THAT CAN REMAIN DISCRETE AND ROOTED IN THE BOUNDARY-LAYER OWING TO THE MARKED INCREASE IN LOW-LEVEL SHEAR AS LLJ INTENSIFIES. TSTMS WILL BECOME INCREASINGLY WIDESPREAD SATURDAY NIGHT NEWD INTO THE MID MO VALLEY ALONG BROADENING/STRENGTHENING LLJ. THE STRONGEST STORMS WILL REMAIN CAPABLE OF PRIMARILY DAMAGING WINDS AND LARGE HAIL. ...HUDSON VALLEY INTO NEW ENGLAND... CONSIDERABLE CLOUDS AND PRECIPITATION WILL LIMIT DESTABILIZATION AHEAD OF FRONT MOVING THROUGH REGION. HOWEVER...HEIGHT FALLS WILL CONTRIBUTE TO SOME WEAK INSTABILITY...SUPPORTING A LOOSELY ORGANIZED CONVECTIVE LINE OR LINE SEGMENTS. GIVEN THE RELATIVELY STRONG UNIDIRECTIONAL WIND FIELDS...SOME THREAT FOR LOCALIZED DAMAGING WINDS WILL EXIST FROM LATE MORNING THROUGH THE AFTERNOON. ..MEAD.. 03/31/2006  From SWODY2 at goshenarc.org Wed Mar 1 05:59:43 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 01 Mar 2006 00:59:43 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060301060104.D4445D43D1@mail.goshen.edu> ACUS02 KWNS 010559 SWODY2 SPC AC 010558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST TUE FEB 28 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER FLOW REGIME ON THU WILL FEATURE TROUGHS ON BOTH COASTS AND A RIDGE IN THE CNTRL PORTIONS OF THE COUNTRY. THE SHORTWAVE TROUGH MOVING ACROSS THE NRN INTERMOUNTAIN WEST EARLY WED WILL AMPLIFY ALONG THE SRN PERIPHERY OF THE POLAR VORTEX...THEN DIG SEWD THROUGH THE GRTLKS AND OFF THE ERN SEABOARD BY MIDDAY THU. IN ITS WAKE...A COLD FRONT WILL SETTLE SWD INTO THE DEEP S AND THE SRN HIGH PLAINS. TO THE WEST...THE UPPER TROUGH AXIS ALONG THE PAC NW COAST WILL BE SLOW TO MOVE EWD AS THE NEXT IN A SERIES OF DISTURBANCES DROPS SWD INTO THE MEAN TROUGH POSITION. NUMEROUS SHORTWAVES EJECTING NEWD FROM THE ERN PAC WILL TRANSLATE NEWD INTO THE GRT BASIN AND NRN INTERMOUNTAIN WEST. ...SRN PLAINS/ROCKIES... COLD FRONT SHOULD SETTLE INTO CNTRL TX NWWD INTO CNTRL NM THROUGH MIDDAY THU. ELY UPSLOPE FLOW IN WAKE OF THIS FRONT WILL PROBABLY BE RESPONSIBLE FOR A FEW TSTMS EARLY IN THE PERIOD ACROSS NM. BUT...RIDGING ALOFT DOWNSTREAM FROM THE WEST COAST TROUGH MAY KEEP THE TSTM THREAT ISOLD. A PERSISTENT CAP AND RIDGING ALOFT ARE EXPECTED TO PREVENT SURFACE BASED TSTMS THROUGH THE DAY ALONG THE FRONT ACROSS CNTRL TX. BUT...AS THE SELY LLJ ACCELERATES LATER THU NIGHT...ELEVATED CONVECTION WILL LIKELY DEVELOP ANYWHERE FROM THE SRN TX PNHDL EWD INTO N TX OR SRN OK. ISOLD STRONGER STORMS MAY PRODUCE SMALL HAIL...BUT SEVERE WEATHER IS NOT ANTICIPATED. ...OH VLY/MID-ATLANTIC... ELEVATED CONVECTION WITH ONE OR TWO LIGHTNING STRIKES MAY BE ONGOING AT 12Z THU ALONG THE NOSE OF A STRONG LLJ ACROSS PORTIONS OF THE OH VLY/CNTRL APPALACHIANS. BUT...AS CYCLOGENESIS TAKES PLACE OFF DELMARVA...MASS CONVERGENCE QUICKLY SHIFTS OFF THE COAST AND TSTM PROBABILITIES SHOULD QUICKLY WANE WED MORNING. ...SACRAMENTO VLY CA... CYCLONIC FLOW ALOFT...STEEP LAPSE RATES AND RESIDUAL BOUNDARY LAYER MOISTURE MAY BE SUFFICIENT FOR SCT TSTMS ACROSS NRN/CNTRL CA THU AFTN. COOL PROFILES COULD SUPPORT SMALL HAIL IN THE STRONGER STORMS. ..RACY.. 03/01/2006  From SWODY2 at goshenarc.org Wed Mar 1 17:31:07 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 01 Mar 2006 12:31:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060301173235.94F2BD48C0@mail.goshen.edu> ACUS02 KWNS 011730 SWODY2 SPC AC 011729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CST WED MAR 01 2006 VALID 021200Z - 031200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BASIC SYNOPTIC PATTERN WILL REMAIN CHARACTERIZED BY CYCLONE OVER CANADIAN MARITIMES...MEAN RIDGE OVER CENTRAL CONUS...AND PACIFIC TROUGH. STRONG SHORTWAVE TROUGH THAT IS NOW BREACHING MEAN RIDGE POSITION OVER NRN PLAINS WILL ACCELERATE ESEWD FROM UPPER MS VALLEY TO MID ATLANTIC REGION AND LOSE AMPLITUDE. HEIGHTS WILL BUILD AGAIN OVER CENTRAL CONUS BEHIND THIS FEATURE AND IN ADVANCE OF HIGH-AMPLITUDE PACIFIC TROUGH. VORTICITY MAX NOW LOCATED ABOUT 550 NM W OF CAPE MENDOCINO SHOULD MOVE INLAND CENTRAL/NRN CA COAST BETWEEN 2/12-2/18Z...BEFORE EJECTING NEWD AND LOSING AMPLITUDE OVER ERN ORE. FARTHER UPSTREAM...SPEED MAX NOW IS EVIDENT IN MOISTURE CHANNEL IMAGERY OVER PACIFIC...AROUND 140-145W AND W OF BC/WA/ORE COASTS. THIS FEATURE IS EXPECTED TO DIG SEWD THEN EWD AROUND BASE OF BROADER TROUGH...WITH STRONG SHORTWAVE TROUGH DEVELOPING AND MOVING ASHORE CA COAST AROUND END OF PERIOD. AT SFC...CYCLONE NOW OVER NERN KS/SERN NEB/NWRN MO AREA WILL MOVE EWD FROM OH VALLEY INTO N-CENTRAL APPALACHIANS...REDEVELOPING OFFSHORE MID-ATLANTIC COAST BY 3/00Z. TRAILING COLD FRONT SHOULD REACH FL PANHANDLE...MIDDLE TX COAST AND TX BIG BEND REGION BY END OF PERIOD...BECOMING STATIONARY OVER SW TX IN RESPONSE TO PRESSURE FALLS IN LEE OF ROCKIES. ...WRN CONUS... LOW-MIDDLE LEVEL FRONTAL ZONE -- NOW EVIDENT AS DEEP-LAYER CLOUD BAND JUST OFFSHORE WA/ORE COASTS WITH EMBEDDED AREAS OF CG LIGHTNING -- WILL MOVE INLAND AND DECELERATE ACROSS GREAT BASIN. THIS FEATURE SHOULD DENOTE ERN EDGE OF FORCING FAVORABLE FOR CONVECTION DURING DAY-2 PERIOD AS WELL. W OF BAROCLINIC ZONE...COMBINATION OF GRADUAL COOLING ALOFT ASSOCIATED WITH EWD MOVEMENT OF SYNOPTIC TROUGH TOWARD COAST -- AND MORE CONCENTRATED UVV ASSOCIATED WITH LANDFALLING SHORTWAVES -- WILL CONTRIBUTE TO INCREASING TSTM POTENTIAL INLAND. THIS DESTABILIZATION IS EVIDENT ATTM IN LARGE AREA OF GLACIATED CONVECTION THAT COVERS MUCH OF NERN PACIFIC E OF SPEED MAX. SMALL HAIL IS POSSIBLE WITH SOME TSTMS UNDER COLDEST MIDLEVEL AIR...AND STRONG GUSTS MAY ACCOMPANY SOME TSTMS IN FRONTAL ZONE THAT ARE EMBEDDED IN ENHANCED SWLY GRADIENT WINDS. HOWEVER SEVERE POTENTIAL APPEARS TOO ISOLATED...MARGINAL AND DISORGANIZED TO DELINEATE PROBABILITIES ATTM. ...MID/UPPER OH VALLEY... ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE DURING FIRST FEW HOURS OF PERIOD...BEFORE MIDLEVEL TROUGH FURTHER WEAKENS AND SFC CYCLONE SHIFTS OFFSHORE. STRONG ISENTROPIC ASCENT NE-SE OF SFC CYCLONE IS EXPECTED TO RAISE PARCELS TO LFC AMIDST MARGINAL LOW LEVEL MOISTURE...A CONTINUATION OF REGIME DISCUSSED IN DAY-1 OUTLOOK. ELEVATED MUCAPES SHOULD REMAIN WEAK -- GENERALLY UNDER 200 J/KG IN MOST AREAS...PRECLUDING SEVERE THREAT. ...SRN HIGH PLAINS...SRN ROCKIES... ISOLATED TSTMS ARE POSSIBLE EARLY-MIDMORNING HOURS OVER PORTIONS NERN NM AND/OR TX PANHANDLE...IN REGIME OF STRONG FRONTOGENETIC FORCING BUT MARGINAL MOISTURE. FCST SOUNDINGS INDICATE ENOUGH MIDLEVEL MOISTENING TO YIELD MUCAPES UP TO NEAR 200 J/KG...HIGHLY ELEVATED WITH BASES IN 550-650 MB LAYER. CAPPING AND DRY BOUNDARY LAYER THEN SHOULD PRECLUDE DIURNAL/SFC-BASED TSTMS. AFTER DARK...NWRN EDGE OF FAVORABLY MOISTENING RETURN FLOW AIR SHOULD BE ISENTROPICALLY LIFTED TO LFC ALONG ELEVATED FRONTAL ZONE...ACROSS PORTIONS N-CENTRAL THROUGH NWRN AND W-CENTRAL TX. CONVECTION IN THIS REGIME SHOULD BE DEEPER THAN ACTIVITY FROM PREVIOUS MORNING. FCST SOUNDINGS INDICATE MUCAPES TO AROUND 500-700 J/KG ROOTED NEAR 850 MB...AND POTENTIALLY 35-50 KT EFFECTIVE SHEAR. THOUGH SOME ISOLATED HAIL IS POSSIBLE...CONCERNS OVER MOISTURE AVAILABILITY PRECLUDE SEVERE PROBABILITIES ATTM. ..EDWARDS.. 03/01/2006  From SWODY2 at goshenarc.org Sat Mar 4 05:56:14 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Mar 2006 00:56:14 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060304055859.6D356D43D9@mail.goshen.edu> ACUS02 KWNS 040556 SWODY2 SPC AC 040555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 PM CST FRI MAR 03 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LOW-AMPLITUDE SHORT-WAVE TROUGH IS FORECAST TO EXTEND N-S ACROSS THE PLAINS STATES AT THE START OF THE PERIOD...SUPERIMPOSED UPON THE LARGE-SCALE MEAN RIDGE. THIS TROUGH WILL MOVE EWD WITH TIME -- LIKELY IN PIECEMEAL FASHION...WHILE RIDGE RE-AMPLIFIES ACROSS THE ERN ROCKIES/HIGH PLAINS IN ITS WAKE. MEANWHILE...A TROUGH WILL MOVE EWD ACROSS THE ERN PACIFIC...WITH CYCLONIC FLOW ALONG THE LEADING EDGE OF THIS FEATURE SPREADING ACROSS THE W COAST STATES AND EVENTUALLY INTO THE GREAT BASIN. AT THE SURFACE...WEAK FRONT/TROUGH WILL MOVE QUICKLY EWD FROM THE CENTRAL PLAINS ACROSS THE MID MS/LOWER OH/TN VALLEYS...WHILE SAGGING MORE SLOWLY SWD ACROSS OK/AR INTO NRN TX/NRN LA THROUGH THE END OF THE PERIOD. ...SERN KS/ERN OK/NERN TX EWD INTO TN/NRN MS/NRN AL... SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ACROSS NRN AND WRN PORTIONS OF THIS REGION...WITHIN WARM ADVECTION E OF SURFACE LOW/BOUNDARY. THOUGH MUCH OF THIS CONVECTION SHOULD DIURNALLY WEAKEN...NEW SHOWERS AND THUNDERSTORMS SHOULD DEVELOP WITHIN MARGINALLY-UNSTABLE AIRMASS NEAR FRONT...FROM WRN TN ACROSS AR AND PERHAPS INTO SERN OK/NERN TX. GREATEST INSTABILITY SHOULD EXIST ACROSS S CENTRAL OK/N TX...BUT EXPECT AIRMASS TO REMAIN GENERALLY CAPPED ACROSS THIS PORTION OF THE REGION. WITH WNWLY FLOW ABOVE THE BOUNDARY LAYER INCREASING TO NEAR 40 KT AT MID-LEVELS...SOME POTENTIAL FOR A FEW MORE ORGANIZED/SUSTAINED UPDRAFTS AND ASSOCIATED LOW-END SEVERE THREAT WOULD EXIST COULD STORMS DEVELOP WITHIN THIS MORE UNSTABLE AIRMASS. WILL NOT INTRODUCE SEVERE PROBABILITIES ATTM...BUT LOW PROBABILITIES MAY BE REQUIRED IN LATER UPDATES SHOULD IT BECOME MORE APPARENT THAT CAP MAY BE LOCALLY BREACHED. ..GOSS.. 03/04/2006  From SWODY2 at goshenarc.org Sat Mar 4 17:18:40 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Mar 2006 12:18:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060304172135.B5DDDD4634@mail.goshen.edu> ACUS02 KWNS 041719 SWODY2 SPC AC 041718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CST SAT MAR 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A PROMINENT SHORT WAVE TROUGH...NOW CENTERED OVER ID PER WATER VAPOR IMAGERY...IS EXPECTED TO TRACK SLOWLY EWD ACROSS THE DAKOTAS/SRN CANADA ON SUNDAY AS IT TOPS THE CENTRAL STATES RIDGE. THIS TROUGH IS THEN PROGGED TO TURN SEWD TOWARD THE WRN GREAT LAKES LATE DAY 2...AS THE RIDGE RE-AMPLIFIES IN ITS WAKE. THE SRN EXTENT OF THIS TROUGH COMBINED WITH WEAKER/LOW AMPLITUDE PACIFIC WAVES SHOULD TRANSLATE EWD ACROSS THE CENTRAL/SRN PLAINS TOWARD THE OH/TN RIVER VALLEYS AND DEEP SOUTH. IN THE LOW-LEVELS...A FRONT ASSOCIATED WITH THE NRN SYSTEM SHOULD MOVE QUICKLY EWD ACROSS THE MID MS AND OH/TN RIVER VALLEYS...REACHING OH INTO ERN KY/TN TO NRN MS BY 12Z MONDAY. THE SRN EXTENT OF THIS BOUNDARY WILL LIKELY MOVE AT A SLOWER PACE ACROSS OK/AR INTO NRN TX. MEANWHILE...A PACIFIC TROUGH /CURRENTLY LOCATED SEVERAL HUNDRED MILES OFF THE CA/ORE COASTS NEAR 140W/ IS EXPECTED TO MOVE INLAND OVER THE WRN STATES DURING THE SECOND HALF OF DAY 2. OFFSHORE THUNDERSTORM THREAT SHOULD INCREASE LATE SUNDAY AFTERNOON...AND THEN ALONG THE COASTAL REGIONS OF NRN CA TO WA AS A STEEPER LAPSE RATE ENVIRONMENT SPREADS INLAND WITH THE PACIFIC TROUGH. ...ERN OK/WRN AR/NERN TX/NWRN LA... SLY LOW-LEVEL FLOW...THOUGH VEERING WITH TIME AND LIMITING CONVERGENCE ALONG THE FRONT...IS EXPECTED TO MAINTAIN MOISTURE RETURN ACROSS THE ARKLATEX INTO LOWER/MID MS RIVER VALLEY. SURFACE DEWPOINTS IN THE UPPER 50S/LOWER 60S COMBINED WITH MODEST LAPSE RATES /6.5-7 C/KM/ AND SOME SURFACE HEATING SHOULD RESULT IN AN AXIS OF MODERATE INSTABILITY FROM NERN TX INTO PARTS OF ERN OK/WRN AR BY SUNDAY AFTERNOON. LATE DAY 1 THUNDERSTORMS SHOULD BE ONGOING AT THE START OF DAY 2 ACROSS SERN NEB/ERN KS AND POTENTIALLY ERN OK IN ASSOCIATION WITH WAA REGIME ALONG THE NOSE OF LLJ. THESE ELEVATED STORMS MAY WEAKEN SOME DURING THE MORNING AND/OR GRADUALLY INCREASE IN COVERAGE AGAIN ALONG THE NRN EXTENT OF MOISTURE RETURN AND WAA WITH THE VEERING LLJ ACROSS MO/PARTS OF AR INTO THE LOWER OH/TN RIVER VALLEYS. WEAK INSTABILITY IS PROGGED TO PRECLUDE A SEVERE THREAT WITH THIS ACTIVITY. DESPITE WEAKER LARGE SCALE FORCING FARTHER TO THE SW OVER THE ARKLATEX REGION...STRONGER AFOREMENTIONED INSTABILITY ACROSS THIS AREA AND STRONG DEEP LAYER SHEAR WOULD SUPPORT A POTENTIAL FOR ORGANIZED STORMS/SEVERE THREAT. MODELS SUGGEST SURFACE HEATING ALONG THE WRN/SRN PERIPHERY OF CLOUD SHIELD ASSOCIATED WITH ELEVATED CONVECTION MAY BECOME SUFFICIENT TO WEAKEN THE CAP FOR SURFACE BASED STORMS LATE SUNDAY AFTERNOON ACROSS WRN AR/ERN OK INTO NERN TX. GIVEN THIS TREND FOR THE DEVELOPMENT OF STRONGER INSTABILITY AND CONDITIONAL POTENTIAL FOR SURFACE BASED STORMS...LOW SEVERE PROBABILITIES WILL BE INTRODUCED WITH THIS OUTLOOK. HIGHER PROBABILITIES AND CATEGORICAL RISK MAY BE REQUIRED IN LATER OUTLOOKS...IF CONFIDENCE BECOMES GREATER FOR WIDESPREAD THREAT OF ORGANIZED STORMS/SEVERE THREAT. ..PETERS.. 03/04/2006  From SWODY2 at goshenarc.org Mon Mar 6 05:47:38 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 00:47:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306055239.A6998D4939@mail.goshen.edu> ACUS02 KWNS 060548 SWODY2 SPC AC 060547 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1147 PM CST SUN MAR 05 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE IS FORECAST TO SHIFT EWD FROM THE CENTRAL INTO THE ERN CONUS THIS PERIOD...AS WRN TROUGH -- COMPRISED OF SEVERAL SMALLER-SCALE FEATURES -- LIKEWISE PROGRESSES EWD. ONE PIECE OF THIS TROUGH WILL MOVE NEWD FROM CO/WY ACROSS THE CENTRAL AND NRN PLAINS INTO WRN ONTARIO/THE UPPER MS VALLEY. MEANWHILE...A SECOND SHORT-WAVE TROUGH -- INITIALLY ALONG THE W COAST -- WILL BECOME THE PREDOMINANT FEATURE AS IT MOVES EWD/SEWD WITH TIME. BY THE END OF THE PERIOD...THE AXIS OF THIS TROUGH SHOULD EXTEND FROM THE CANADIAN PRAIRIE SWD TO THE FOUR CORNERS REGION AND THE SSWWD ACROSS NRN BAJA CA. AT THE SURFACE...BROAD LOW PRESSURE INITIALLY OVER THE CENTRAL/NRN HIGH PLAINS WILL MOVE SEWD ACROSS THE CENTRAL PLAINS INTO KS/OK BY THE END OF THE PERIOD. THOUGH CONVECTION SHOULD BE WIDESPREAD ACROSS PORTIONS OF THE INTERIOR WEST...MORE VIGOROUS CONVECTION IS EXPECTED ACROSS THE MO VALLEY AND VICINITY WHERE GREATER INSTABILITY WILL EXIST. ...MID AND LOWER MO VALLEY/MID MS VALLEY... WARM SECTOR SHOULD REMAIN CAPPED THIS PERIOD ACROSS THE SRN PLAINS...DESPITE STEEP LAPSE RATES/MODERATE POTENTIAL INSTABILITY ABOVE CAPPING INVERSION. AS A RESULT...EXPECT THUNDERSTORM DEVELOPMENT THIS PERIOD TO BE CONFINED TO ZONE OF STRONG WARM ADVECTION/ISENTROPIC LIFT...WHICH SHOULD SHIFT EWD FROM THE CENTRAL PLAINS ACROSS THE MO/MS VALLEYS. ATTM...MODELS SUGGEST THAT 500 TO 1500 J/KG ELEVATED CAPE SHOULD EVOLVE WITH TIME ACROSS MUCH OF MO/IA/IL AND VICINITY...AIDED BY STRONG LOW-LEVEL JET AND ASSOCIATED THETA-E ADVECTION. WITH 50 TO 60 KT SWLY FLOW AT MID LEVELS ON SRN PERIPHERY OF SHORT-WAVE TROUGH CROSSING THE CENTRAL/NRN PLAINS...SHEAR/INSTABILITY COMBINATION APPEARS SUPPORTIVE OF A THREAT FOR AT LEAST MARGINALLY-SEVERE HAIL. THEREFORE...WILL INTRODUCE LOW SEVERE PROBABILITY ACROSS THIS REGION -- MAINLY FOR LATE AFTERNOON THROUGH THE OVERNIGHT HOURS. ..GOSS.. 03/06/2006  From SWODY2 at goshenarc.org Mon Mar 6 09:04:33 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 04:04:33 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306090711.D2260D4939@mail.goshen.edu> ACUS02 KWNS 060903 SWODY2 SPC AC 060902 DAY 2 CONVECTIVE OUTLOOK AMEND 1 NWS STORM PREDICTION CENTER NORMAN OK 0302 AM CST MON MAR 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... AMENDED TO ADD THUNDER/SEVERE PROBABILITY ACROSS OK/WRN N TX ...SYNOPSIS... UPPER RIDGE IS FORECAST TO SHIFT EWD FROM THE CENTRAL INTO THE ERN CONUS THIS PERIOD...AS WRN TROUGH -- COMPRISED OF SEVERAL SMALLER-SCALE FEATURES -- LIKEWISE PROGRESSES EWD. ONE PIECE OF THIS TROUGH WILL MOVE NEWD FROM CO/WY ACROSS THE CENTRAL AND NRN PLAINS INTO WRN ONTARIO/THE UPPER MS VALLEY. MEANWHILE...A SECOND SHORT-WAVE TROUGH -- INITIALLY ALONG THE W COAST -- WILL BECOME THE PREDOMINANT FEATURE AS IT MOVES EWD/SEWD WITH TIME. BY THE END OF THE PERIOD...THE AXIS OF THIS TROUGH SHOULD EXTEND FROM THE CANADIAN PRAIRIE SWD TO THE FOUR CORNERS REGION AND THE SSWWD ACROSS NRN BAJA CA. AT THE SURFACE...BROAD LOW PRESSURE INITIALLY OVER THE CENTRAL/NRN HIGH PLAINS WILL MOVE SEWD ACROSS THE CENTRAL PLAINS INTO KS/OK BY THE END OF THE PERIOD. THOUGH CONVECTION SHOULD BE WIDESPREAD ACROSS PORTIONS OF THE INTERIOR WEST...MORE VIGOROUS CONVECTION IS EXPECTED ACROSS PARTS OF THE S CENTRAL CONUS WHERE GREATER INSTABILITY WILL EXIST. ...CENTRAL AND WRN OK/WRN N TX... DRYLINE IS FORECAST TO MIX EWD ACROSS WRN OK/WRN N TX DURING THE AFTERNOON...INTO A MOIST/POTENTIALLY-UNSTABLE BUT CAPPED AIRMASS. HOWEVER...AS RIDGE OVER THE S CENTRAL CONUS SHIFTS EWD AND HEIGHTS FALL IN RESPONSE TO A WEAK SRN STREAM SHORT-WAVE FORECAST TO MOVE NEWD ACROSS THIS REGION...EXPECT ISOLATED STORMS TO DEVELOP ALONG DRYLINE WHERE CAP BECOMES LOCALLY BREACHED DURING THE LATE AFTERNOON. WITH VEERING/INCREASING FLOW WITH HEIGHT ANTICIPATED ACROSS THIS REGION...ANY STORMS WHICH DEVELOP WOULD BECOME SUPERCELLS. THEREFORE...WILL INTRODUCE 5% SEVERE THREAT ACROSS THIS REGION. ...MID AND LOWER MO VALLEY/MID MS VALLEY... EXPECT THUNDERSTORM DEVELOPMENT TO OCCUR THIS PERIOD WITHIN ZONE OF STRONG WARM ADVECTION/ISENTROPIC LIFT...WHICH SHOULD SHIFT EWD FROM THE CENTRAL PLAINS ACROSS THE MO/MS VALLEYS. ATTM...MODELS SUGGEST THAT 500 TO 1500 J/KG ELEVATED CAPE SHOULD EVOLVE WITH TIME ACROSS MUCH OF MO/IA/IL AND VICINITY...AIDED BY STRONG LOW-LEVEL JET AND ASSOCIATED THETA-E ADVECTION. WITH 50 TO 60 KT SWLY FLOW AT MID LEVELS ON SRN PERIPHERY OF SHORT-WAVE TROUGH CROSSING THE CENTRAL/NRN PLAINS...SHEAR/INSTABILITY COMBINATION APPEARS SUPPORTIVE OF A THREAT FOR AT LEAST MARGINALLY-SEVERE HAIL. THEREFORE...WILL INTRODUCE LOW SEVERE PROBABILITY ACROSS THIS REGION -- MAINLY FOR LATE AFTERNOON THROUGH THE OVERNIGHT HOURS. ..GOSS.. 03/06/2006  From SWODY2 at goshenarc.org Mon Mar 6 17:29:46 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Mar 2006 12:29:46 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060306173225.C2A1FD4968@mail.goshen.edu> ACUS02 KWNS 061729 SWODY2 SPC AC 061728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST MON MAR 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN KS AND NRN/W CNTRL OK... ...CNTRL/SRN PLAINS AND MID-MS VLY... A SHORTWAVE TROUGH MOVING ONSHORE CNTRL CA ATTM IS EXPECTED TO TRANSLATE EWD ACROSS THE GRT BASIN TODAY...THEN REACH THE CNTRL/SRN PLAINS BY TUE AFTN. A LEE LOW OVER THE CNTRL HIGH PLAINS WILL DEVELOP EWD INTO CNTRL KS BY TUE AFTN WITH A DRYLINE SWD THROUGH SCNTRL KS...WRN OK AND WCNTRL TX. INCREASING SLY FLOW AHEAD OF THE MID-LEVEL TROUGH WILL ADVECT A NARROW RIBBON OF MSTR /SFC DEW POINTS AROUND 60 DEGREES F/ INTO PARTS OF CNTRL OK/KS JUST AHEAD OF THE DRYLINE BY TUE AFTN. MID-LEVEL THERMAL PROFILES WILL REMAIN COOL...AOB MINUS 15 DEGREES C. PRIND THAT WHILE THERE WILL BE CONSIDERABLE HIGH LEVEL SUB-TROPICAL CONVECTION ARCING ACROSS THE SRN PLAINS...SUFFICIENT CLEARING/INSOLATION WILL BE PRESENT BY MID-AFTN ACROSS WCNTRL OK NWD INTO CNTRL KS FOR MLCAPES OF 2000-2500 J/KG. AS TAIL END OF THE SHORTWAVE TROUGH BRUSHES ACROSS THE DRYLINE AND HEATING WEAKENS CINH...TSTM INITIATION SHOULD OCCUR FROM SCNTRL KS-WCNTRL OK BY LATE TUE AFTN. VERTICAL WIND PROFILES WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS AND VERY LARGE HAIL IS LIKELY GIVEN THE STEEP LAPSE RATES AND MAGNITUDE OF SHEAR. AN ISOLD TORNADO IS ALSO POSSIBLE. TSTMS SHOULD EVENTUALLY MOVE OFF THE DRYLINE AND PROBABLY WEAKEN OVER CNTRL OK. HOWEVER...INCREASING SLY LLJ OF 60-70 KTS WILL FAVOR A NOCTURNAL MCS OR TWO ACROSS THE OZARKS AND MID-MS VLY THROUGH EARLY WED. ISOLD TSTMS MAY PRODUCE LARGE HAIL. ..RACY.. 03/06/2006  From SWODY2 at goshenarc.org Tue Mar 7 07:57:32 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 02:57:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307080232.411ABD46C1@mail.goshen.edu> ACUS02 KWNS 070757 SWODY2 SPC AC 070755 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 AM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MO SWWD INTO CENTRAL TX... ...SYNOPSIS... GFS AND NAM CONTINUE TO DIFFER WITH THEIR HANDLING OF THE UPPER SYSTEM EJECTING OUT OF THE SWRN U.S./SRN ROCKIES INTO THE SRN PLAINS THIS PERIOD...AS WELL AS WITH THEIR POSITION OF THE DRYLINE. OVERALL HOWEVER...UPPER TROUGH WILL SHIFT EWD INTO THE SRN PLAINS THROUGH THE PERIOD. BROAD SURFACE LOW IS FORECAST OVER KS/OK BY LATE AFTERNOON...WITH A WARM FRONT EXTENDING ENEWD ACROSS ERN KS/NRN MO AND INTO IL...AND A DRYLINE EXTENDING SWD ACROSS OK/WRN N TX. AS UPPER TROUGH EJECTS...BOTH THE WARM FRONT AND THE DRYLINE SHOULD BECOME A FOCUS FOR SEVERE STORM DEVELOPMENT. ...SRN PLAINS NEWD INTO THE MID/LOWER MO VALLEY... SEASONABLY-MOIST BOUNDARY LAYER /DEWPOINTS IN THE UPPER 50S TO LOW 60S/ WILL CONTINUE TO ADVECT NWD ACROSS THE SRN AND CENTRAL PLAINS/OZARKS REGION AHEAD OF ADVANCING UPPER TROUGH AND ASSOCIATED SURFACE LOW. THOUGH ENEWD ADVECTION OF EML SHOULD RESULT IN A CAPPED BOUNDARY LAYER THROUGH MID AFTERNOON...DAYTIME HEATING AND INCREASING UVV AHEAD OF APPROACHING TROUGH SHOULD ALLOW STORMS TO DEVELOP BY LATE AFTERNOON FROM SRN KS SWD ACROSS WRN/CENTRAL OK INTO N TX AHEAD OF DRYLINE. STORMS SHOULD ALSO REDEVELOP/INCREASE INVOF WARM FRONT ACROSS ERN KS/MO BY AFTERNOON AS UPPER TROUGH APPROACHES. VERY STRONG DEEP-LAYER WIND FIELD ACCOMPANYING THIS FEATURE WILL RESULT IN SHEAR MORE THAN SUFFICIENT FOR SEVERE/SUPERCELL STORMS. EXPECT INITIAL CONVECTIVE DEVELOPMENT ALONG DRYLINE TO BE ISOLATED...WITH MORE WIDESPREAD STORMS LIKELY ALONG WARM FRONT ACROSS ERN KS/MO. ALONG WITH LARGE HAIL...LOCALLY DAMAGING WINDS AND AT LEAST A LOW-END TORNADO THREAT WILL ALSO EXIST. STORMS SHOULD INCREASE IN COVERAGE OVERNIGHT AS STRONG HEIGHT FALLS CONTINUE TO OVERSPREAD THE AREA. A MORE LINEAR STORM MODE SHOULD EVOLVE WITH TIME AHEAD OF DRYLINE WITH EMBEDDED SUPERCELLS -- RESULTING IN AN INCREASE IN DAMAGING WIND THREAT. SEVERE THREAT SHOULD PERSIST THROUGH THE NIGHT...EXTENDING FROM THE MIDDLE MS VALLEY SWWD INTO CENTRAL TX BY THE END OF THE PERIOD. ..GOSS.. 03/07/2006  From SWODY2 at goshenarc.org Tue Mar 7 17:38:02 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 12:38:02 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307174038.63624D4946@mail.goshen.edu> ACUS02 KWNS 071738 SWODY2 SPC AC 071737 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL/SRN PLAINS... ...CNTRL/SRN PLAINS... LONGWAVE TROUGH OVER THE WCOAST IS EXPECTED TO TRANSLATE TO THE PLAINS ON WED. SRN PART OF THE TROUGH WILL AMPLIFY WITH A STRONG IMPULSE DIGGING INTO THE DESERT SW WED MORNING AND THEN TURNING EWD INTO THE SRN PLAINS BY EARLY THU. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ALONG A BAROCLINIC ZONE FROM CNTRL KS EARLY WED INTO NRN MO BY WED AFTN. A TRIPLE POINT WILL DEVELOP OVER NWRN/NCNTRL OK DURING THE AFTN WED. THE DRYLINE WILL LIKELY MIX INTO CNTRL PORTIONS OF OK AND KS DURING THE LATE AFTN WHILE THE COLD FRONT ACROSS CNTRL KS MOVES SWD ACROSS OK THROUGH EARLY THU. ELEVATED TSTMS SHOULD BE ONGOING EARLY WED ACROSS THE OZARKS EWD INTO THE OH VLY...ALONG THE NOSE OF A WSWLY LLJ. THESE TSTMS WILL LIKELY SHIFT NWD INTO THE UPPER MIDWEST AND UPPER MS VLY THROUGH THE DAY AS A WARM FRONT TRANSLATES NWD...SIMILAR TO THE GFS SOLUTION. ISOLD HAIL MAY ACCOMPANY THESE TSTMS...PRIMARILY ACROSS THE OZARKS DURING THE MORNING. THE WARM SECTOR SHOULD EXPAND WED AFTN AS MID-UPPER 50S SFC DEW POINTS ADVECT NWD INTO CNTRL/ERN KS AND MO BENEATH STEEPENING MID-LEVEL LAPSE RATES. EML WILL BE STRONGEST ACROSS OK/TX AND SUGGESTS THE CAP MAY HOLD THROUGH MID-AFTN AT LEAST. CONVECTION SHOULD INCREASE FIRST ALONG THE TRIPLE POINT IN KS WHERE HEATING AND LOCAL CONVERGENCE ERASES CINH. STORMS SHOULD DEVELOP NEWD FROM SCNTRL KS ALONG THE SEWD MOVING COLD FRONT INTO WRN MO. FARTHER S...ISOLD TSTMS MAY FORM ALONG THE DRYLINE INTO WCNTRL OK DURING PEAK HEATING. BUT...STRONGER FORCING FOR ASCENT ASSOCIATED WITH THE APPROACHING WAVE SHOULD BE DELAYED UNTIL AFTER DARK. AT THAT TIME...TSTMS SHOULD BECOME MORE NUMEROUS ALONG/E OF THE DRYLINE AND ALONG/S OF THE COLD FRONT ACROSS OK...SERN KS AND SRN/WRN MO. VERTICAL SHEAR WILL BECOME INCREASINGLY SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL DURING WED AFTN. A FEW TORNADOES WILL BE POSSIBLE...PARTICULARLY ALONG THE TRACK OF THE TRIPLE POINT IN SERN KS OR CNTRL/ERN OK AND WITH CELLS THAT REMAIN DISCRETE THE LONGEST. THE LOW AND MID-LEVEL FLOW WILL GRADUALLY BACK WITH TIME DURING THE EVENING. THUS...WHILE DISCRETE CELLS WILL BE POSSIBLE WED AFTN...EVOLUTION INTO A MORE LINEAR MODE WITH EMBEDDED SUPERCELLS IS LIKELY WED NIGHT. ..RACY.. 03/07/2006  From SWODY2 at goshenarc.org Tue Mar 7 18:51:47 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Mar 2006 13:51:47 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060307185443.037F1D4968@mail.goshen.edu> ACUS02 KWNS 071852 SWODY2 SPC AC 071851 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1251 PM CST TUE MAR 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL/SRN PLAINS... CORRECTED FOR TRIPLE POINT POSITION ...CNTRL/SRN PLAINS... LONGWAVE TROUGH OVER THE WCOAST IS EXPECTED TO TRANSLATE TO THE PLAINS ON WED. SRN PART OF THE TROUGH WILL AMPLIFY WITH A STRONG IMPULSE DIGGING INTO THE DESERT SW WED MORNING AND THEN TURNING EWD INTO THE SRN PLAINS BY EARLY THU. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ALONG A BAROCLINIC ZONE FROM CNTRL KS EARLY WED INTO NRN MO BY WED AFTN. A TRIPLE POINT WILL DEVELOP OVER SCNTRL KS DURING THE AFTN WED WITH THE DRYLINE MIXING INTO CNTRL OK AND SERN KS BY EVENING. THE COLD FRONT ACROSS CNTRL KS SHOULD MOVE SWD INTO AND ACROSS OK THROUGH EARLY THU. ELEVATED TSTMS SHOULD BE ONGOING EARLY WED ACROSS THE OZARKS EWD INTO THE OH VLY...ALONG THE NOSE OF A WSWLY LLJ. THESE TSTMS WILL LIKELY SHIFT NWD INTO THE UPPER MIDWEST AND UPPER MS VLY THROUGH THE DAY AS A WARM FRONT TRANSLATES NWD...SIMILAR TO THE GFS SOLUTION. ISOLD HAIL MAY ACCOMPANY THESE TSTMS...PRIMARILY ACROSS THE OZARKS DURING THE MORNING. THE WARM SECTOR SHOULD EXPAND WED AFTN AS MID-UPPER 50S SFC DEW POINTS ADVECT NWD INTO CNTRL/ERN KS AND MO BENEATH STEEPENING MID-LEVEL LAPSE RATES. EML WILL BE STRONGEST ACROSS OK/TX AND SUGGESTS THE CAP MAY HOLD THROUGH MID-AFTN AT LEAST. CONVECTION SHOULD INCREASE FIRST ALONG THE TRIPLE POINT IN SCNTRL KS WHERE HEATING AND LOCAL CONVERGENCE ERASES CINH. STORMS SHOULD DEVELOP NEWD FROM SCNTRL KS ALONG THE SEWD MOVING COLD FRONT INTO WRN MO. FARTHER S...ISOLD TSTMS MAY FORM ALONG THE DRYLINE INTO CNTRL OK DURING PEAK HEATING. BUT...STRONGER FORCING FOR ASCENT ASSOCIATED WITH THE APPROACHING WAVE SHOULD BE DELAYED UNTIL AFTER DARK. AT THAT TIME...TSTMS SHOULD BECOME MORE NUMEROUS ALONG/E OF THE DRYLINE AND ALONG/S OF THE COLD FRONT ACROSS OK...SERN KS AND SRN/WRN MO. VERTICAL SHEAR WILL BECOME INCREASINGLY SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL DURING WED AFTN. A FEW TORNADOES WILL BE POSSIBLE...PARTICULARLY ALONG THE TRACK OF THE TRIPLE POINT IN SERN KS OR CNTRL/ERN OK AND WITH CELLS THAT REMAIN DISCRETE THE LONGEST. THE LOW AND MID-LEVEL FLOW WILL GRADUALLY BACK WITH TIME DURING THE EVENING. THUS...WHILE DISCRETE CELLS WILL BE POSSIBLE WED AFTN...EVOLUTION INTO A MORE LINEAR MODE WITH EMBEDDED SUPERCELLS IS LIKELY WED NIGHT. ..RACY.. 03/07/2006  From SWODY2 at goshenarc.org Wed Mar 8 07:08:58 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Mar 2006 02:08:58 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060308071151.DE38BD45E5@mail.goshen.edu> ACUS02 KWNS 080709 SWODY2 SPC AC 080708 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CST WED MAR 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER AND MID MS/TN/OH VALLEYS AND EWD INTO THE SERN CONUS... ...SYNOPSIS... STRONG SHORT-WAVE TROUGH MOVING ACROSS TX/OK AT THE START OF THE PERIOD IS FORECAST TO SHIFT CYCLONICALLY EWD/NEWD ACROSS THE MS/TN/OH VALLEYS THROUGH THE PERIOD. THIS FEATURE WILL BE ACCOMPANIED BY VERY STRONG FLOW -- INCLUDING 60 TO 80 KT SLY/SSWLY LOW-LEVEL JET AND 80 TO 100 KT SSWLY FLOW AT MID LEVELS. AS THIS FEATURE SHIFTS EWD/NEWD...LOW PRESSURE IS FORECAST TO CONSOLIDATE INVOF THE MID MS VALLEY AND THEN MOVE NEWD AND APPROACH SRN ONTARIO THROUGH THE END OF THE PERIOD. ASSOCIATED PRE-FRONTAL TROUGH SHOULD MOVE EWD ACROSS THE MS VALLEY DURING THE AFTERNOON...LIKELY ACTING AS A FOCUS FOR SEVERE STORMS. ...MID AND LOWER MS/OH/TN VALLEYS SWD TO THE CENTRAL GULF COAST... STRONG/SEVERE STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS AR AND VICINITY...AHEAD OF UPPER TROUGH. COMBINATION OF SEASONABLY MOIST BOUNDARY LAYER ADVECTING NWD TOWARD THE OH VALLEY AND SOME DAYTIME HEATING...MODERATE DESTABILIZATION /1000 TO 1500 J/KG MEAN-LAYER CAPE/ IS EXPECTED BY AFTERNOON. AS UPPER TROUGH TAKES ON AN INCREASINGLY NEGATIVE TILT WITH TIME AND SURFACE CONVERGENCE AXIS SHIFTS EWD...STORMS SHOULD INCREASE/DEVELOP SWD FROM THE MID MS VALLEY TOWARD THE GULF COAST...LIKELY EVOLVING INTO A SQUALL LINE BY AFTERNOON. ATTM...MOST SIGNIFICANT SEVERE THREAT APPEARS TO BE DAMAGING WINDS...GIVEN VERY STRONG/COMPACT UPPER FEATURE AND CORRESPONDING STRENGTH OF FAIRLY UNIDIRECTIONAL SSWLY DEEP-LAYER WIND FIELD. HAIL AND POSSIBLY A COUPLE TORNADOES WILL ALSO BE POSSIBLE...WITH SHEAR VERY SUPPORTIVE OF SUPERCELLS. SEVERE THREAT IS EXPECTED TO SHIFT EWD ACROSS THE GULF COAST/NEWD ACROSS THE TN AND OH VALLEYS THROUGH THE AFTERNOON/EVENING. HOWEVER...THREAT SHOULD TAPER OFF SOMEWHAT OVERNIGHT...AS DECREASING INSTABILITY ACROSS THE UPPER OH VALLEY...AND DECREASING UVV/CONVERGENCE ACROSS THE SOUTHEAST LEADS TO AN OVERALL DECREASE IN STORM INTENSITY THROUGH THE END OF THE PERIOD. ..GOSS.. 03/08/2006  From SWODY2 at goshenarc.org Wed Mar 8 17:31:00 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Mar 2006 12:31:00 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060308173338.50445D46C1@mail.goshen.edu> ACUS02 KWNS 081731 SWODY2 SPC AC 081730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST WED MAR 08 2006 VALID 091200Z - 101200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER TO MID MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...OZARKS...OH VALLEY AND TN VALLEY... ...MS VALLEY... AN IMPRESSIVE UPPER-LEVEL TROUGH OVER THE DESERT SW WILL EJECT EWD TONIGHT DEEPENING AND BECOMING NEGATIVELY TILTED OVER THE SRN PLAINS THURSDAY. AHEAD OF THIS POTENT UPPER-TROUGH LARGE-SCALE ASCENT WILL BECOME INCREASINGLY FOCUSED AS A 100 KT MID-LEVEL JET PUNCHES INTO THE LOWER MS VALLEY. RICH LOW-LEVEL MOISTURE AHEAD OF THE SYSTEM COMBINED WITH VERY STRONG WIND SHEAR PROFILES SUGGEST THE POTENTIAL FOR A MAJOR SEVERE WEATHER OUTBREAK EXISTS FOR THURSDAY AND THURSDAY NIGHT ACROSS THE LOWER TO MID MS VALLEY. A LARGE COMPLEX OF THUNDERSTORMS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD AS THE TROUGH SWINGS EWD INTO THE SRN PLAINS. AT 12Z MODEL CONSENSUS PLACES A SQUALL-LINE OR BROKEN LINE OF STORMS ALONG THE WEST EDGE OF A WELL-DEVELOPED LOW-LEVEL JET WITH THE LINE EXTENDING SWWD FROM THE LOWER OH VALLEY ACROSS THE OZARKS INTO THE SRN PLAINS. AHEAD OF THE UPPER-LEVEL TROUGH THE STRONG LOW-LEVEL FLOW SHOULD TRANSPORT SFC DEWPOINTS IN THE 60S F AS FAR NORTH AS SRN IL DURING THE DAY. THIS COMBINED WITH THE PROGRESSIVE AND VERY WELL-DEVELOPED NATURE OF THE UPPER-TROUGH SUGGESTS THAT INSTABILITY WILL BE SUFFICIENT FOR SEVERE STORMS. IN ADDITION...THE 15Z TO 18Z FORECAST SOUNDINGS ACROSS THE REGION ON THURSDAY SHOW IMPRESSIVE SHEAR PROFILES WITH STRONG LOW TO MID-LEVEL VEERING AND SUFFICIENT SPEED SHEAR FOR SUPERCELLS WITH WELL-DEVELOP LOW-LEVEL MESOCYCLONES. ALTHOUGH NOT YET CERTAIN...A TORNADO OUTBREAK WILL BE POSSIBLE ESPECIALLY IF A LARGE NUMBER OF STORMS REMAIN DISCRETE AS THE INITIAL LARGE CLUSTER OF STORMS DRIFTS EWD AND EXPANDS FROM NORTH TO SOUTH ACROSS THE MS VALLEY DURING THE AFTERNOON. THE BEST POTENTIAL FOR LONG TRACK STRONG OR VIOLENT TORNADOES SHOULD BE WHERE INSTABILITY IS LOCALLY MAXIMIZED AND JUST AHEAD OF THE SFC LOW AND IN THE NOSE OF THE MID-LEVEL JET. IF THE MAJORITY OF THE STORMS REMAIN LINEAR INSTEAD OF DISCRETE...A WIDESPREAD WIND DAMAGE EVENT WOULD BE MORE LIKELY AS A SQUALL-LINE MOVES EWD ACROSS THE REGION. WIND GUSTS ABOVE 70 KTS AND LARGE HAIL ABOVE 2 INCHES WOULD BE POSSIBLE WITH THE SUPERCELLS AND BOW ECHOES EMBEDDED IN OR AHEAD OF THE LINE. THE HEAVIEST CONCENTRATION OF SEVERE WEATHER EVENTS SHOULD BE ALONG THE MOIST AXIS ACROSS AR...LA...MS AND WRN TN ALTHOUGH SOME SEVERE WEATHER WILL BE POSSIBLE AS FAR NORTH AS THE OH VALLEY AND SRN LOWER MI DUE TO THE STRONG MID-LEVEL FLOW AS THE LEFT EXIT REGION OF THE MID-LEVEL JET PASSES ACROSS THE REGION THURSDAY NIGHT. DURING THE NIGHT...A SOLID LINE SHOULD DRIFT EWD ACROSS THE OH AND TN VALLEYS WITH THE SEVERE WEATHER THREAT GRADUALLY DECREASING. ...WEST COAST... MODEL FORECASTS DEVELOP AN UPPER-LEVEL TROUGH ALONG THE WEST COAST THURSDAY SPREADING STRONG LARGE-SCALE ASCENT INTO WA...ORE AND CA THURSDAY NIGHT. AS THIS OCCURS...STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH THE TROUGH MAY BE ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT ALONG THE IMMEDIATE COASTAL AREAS. HOWEVER...INSTABILITY AND SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH FOR AN OUTLOOK AREA OF SEVERE WEATHER THURSDAY NIGHT. ..BROYLES.. 03/08/2006  From SWODY2 at goshenarc.org Thu Mar 9 06:59:44 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 01:59:44 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309070211.805AAD42E0@mail.goshen.edu> ACUS02 KWNS 090659 SWODY2 SPC AC 090658 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH WILL PREVAIL ACROSS THE CONUS THIS PERIOD. HOWEVER...A SERIES OF SHORT-WAVE TROUGHS -- ONE MOVING QUICKLY NEWD ACROSS THE NERN CONUS AND THE OTHER MOVING OUT OF THE ROCKIES INTO THE CENTRAL/NRN PLAINS LATE -- WILL ALSO BE ASSOCIATED WITH CONVECTIVE WEATHER THIS PERIOD. A STRONG COLD FRONT -- CORRELATED WITH THE NERN U.S. SHORT-WAVE TROUGH -- IS FORECAST TO MOVE EWD ACROSS NEW ENGLAND/THE MID ATLANTIC REGION. FURTHER W...A DEEPENING SURFACE LOW SHOULD MOVE OUT OF THE CENTRAL HIGH PLAINS AND NEWD ACROSS NEB THROUGH THE PERIOD IN CONJUNCTION WITH THE UPPER FEATURE MOVING OUT OF THE ROCKIES. THOUGH SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS BOTH OF THESE AREAS...IT APPEARS ATTM THAT SEVERE THREAT SHOULD REMAIN LIMITED. ...FAR SRN NEW ENGLAND SWD INTO ERN NC... THOUGH STRONGEST FORCING ALOFT AND SHARPEST PORTION OF COLD FRONT SHOULD MOVE NEWD ACROSS NEW ENGLAND...ONLY MINIMAL ELEVATED INSTABILITY IS FORECAST AT BEST. THOUGH GREATEST INSTABILITY IS EXPECTED FURTHER S INTO SC/GA/SRN AL...WEAKER WIND FIELD AND PERSISTENT SURFACE RIDGE SUGGESTS ONLY ISOLATED THUNDERSTORMS AND LITTLE IF ANY SEVERE THREAT ACROSS THIS PORTION OF THE AREA. BETWEEN THE AREA OF STRONGER INSTABILITY OVER THE SOUTHEAST AND STRONGER UVV OVER NEW ENGLAND...A CORRIDOR OF MARGINAL DESTABILIZATION MAY OCCUR AHEAD OF COLD FRONT FROM EXTREME SRN NEW ENGLAND SWD INTO SRN VA/ERN NC. THOUGH STORMS SHOULD REMAIN ISOLATED -- PARTICULARLY WITH SWD EXTENT...DEEP-LAYER WIND FIELD WILL REMAIN MORE THAN SUPPORTIVE OF SEVERE/SUPERCELL STORMS. ATTM...WILL MAINTAIN 5% SEVERE PROBABILITY...WITH GENERALLY WEAK LOW-LEVEL FORCING AND MARGINAL INSTABILITY EXPECTED ATTM BEING THE MAIN LIMITING FACTORS. SHOULD SOMEWHAT GREATER AIRMASS DESTABILIZATION OCCUR INTO NJ/THE DELMARVA REGION...SLIGHT RISK AREA MAY BE REQUIRED IN LATER FORECASTS. ...PORTIONS OF THE CENTRAL/NRN PLAINS INTO THE UPPER MS VALLEY... ELEVATED THUNDERSTORMS SHOULD DEVELOP BY LATE AFTERNOON/EVENING WITHIN ZONE OF WARM ADVECTION NE OF SURFACE LOW/AHEAD OF APPROACHING SHORT-WAVE TROUGH. INSTABILITY SHOULD REMAIN MARGINAL...AND THUS EXPECT ANY HAIL TO REMAIN BELOW SEVERE THRESHOLDS DESPITE FAVORABLY-STRONG FLOW ALOFT. ...THE WEST... SHOWERS ARE FORECAST ACROSS MUCH OF THE WEST THIS PERIOD -- ALONG WITH A FEW THUNDERSTORMS OVER PARTS OF THE AREA -- AS LARGE UPPER TROUGH RESIDES OVER THIS REGION. MINIMAL INSTABILITY SHOULD PRECLUDE ANY APPRECIABLE SEVERE THREAT...THOUGH A STRONGER/MARGINALLY-SEVERE CELL MAY AFFECT COASTAL SRN CA LATE IN THE PERIOD AS MID-LEVEL JET STREAK NOSES SEWD INTO THIS AREA. ..GOSS.. 03/09/2006  From SWODY2 at goshenarc.org Thu Mar 9 17:25:52 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 12:25:52 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309172944.D9631D46B5@mail.goshen.edu> ACUS02 KWNS 091724 SWODY2 SPC AC 091723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1123 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE CONUS IS CURRENTLY UNDER THE INFLUENCE OF A LARGE LONG WAVE TROUGH. A JET MAX OF 130KTS IS FORCING A COLD FRONT INTO THE EASTERN US WHILE ANOTHER JET MAX OF 120KTS IS ENTERING THE WEST COAST NEAR CENTRAL CA. THE JET MAX OVER THE EASTERN US WILL WEAKEN AND QUICKLY MOVE TOWARDS THE NE DURING THIS PERIOD. MEANWHILE...THE JET MAX OVER THE WEST WILL CONTINUE TO DIVE SOUTH INTO THE SW US CAUSING LOW PRESSURE TO FORM AND DEEPEN AS IT MOVES INTO THE PLAINS BY THE END OF THE PERIOD. ...EASTERN US... THE COLD FRONT OVER THE EASTERN US WEAKENS AS THE JET MAX RIDES UP THE LONG WAVE RIDGE OVER THE EAST COAST. AS THE FRONT ENTERS THE REGION IT WILL ENCOUNTER INCREASINGLY STABLE AIR. WEAK INSTABILITY AND STRONG FORCING AT 850MB WILL CAUSE ISOLATED CONVECTION ALONG THE FRONT. FORCING WILL BE STRONG AS A LLJ OF UP TO 70KTS MOVES OVER NJ. AN ISOLATED SEVERE WIND GUST IS POSSIBLE AT THE BEGINNING OF THE PERIOD IN THIS AREA. THE GREATEST INSTABILITY WILL BE IN THE SE US WHERE THERE IS A LACK OF A LIFTING MECHANISM. ISOLATED THUNDERSTORMS BELOW SEVERE LEVELS CAN BE EXPECTED IN THIS AREA. ...PORTIONS OF THE CENTRAL PLAINS... A WARM FRONT WILL MOVE OUT INTO THE PLAINS AHEAD OF THE LOW PRESSURE MOVING OUT OF THE WESTERN US. WEAK INSTABILITY AND WEAK FORCING OVER THE WARM FRONT WILL PROVIDE EARLY MORNING THUNDERSTORMS ALONG AND AHEAD OF THE WARM FRONT AS IT MOVES TOWARDS WI. ...WESTERN US... ISOLATED CONVECTION WILL OCCUR OVER SOME OF THE HIGHER TERRAIN IN THE WEST. A COLD POCKET AT 500MB WITH TEMPERATURES BELOW-30C ALONG WITH WEAK MECHANICAL LIFTING WILL SUPPORT WEAK THUNDERSTORMS/THUNDERSNOW DURING THE PERIOD. ..AFWA.. 03/09/2006  From SWODY2 at goshenarc.org Thu Mar 9 17:49:10 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Mar 2006 12:49:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060309175132.AB0F9D46B5@mail.goshen.edu> ACUS02 KWNS 091749 SWODY2 SPC AC 091723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1123 AM CST THU MAR 09 2006 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE CONUS IS CURRENTLY UNDER THE INFLUENCE OF A LARGE LONG WAVE TROUGH. A JET MAX OF 130KTS IS FORCING A COLD FRONT INTO THE EASTERN US WHILE ANOTHER JET MAX OF 120KTS IS ENTERING THE WEST COAST NEAR CENTRAL CA. THE JET MAX OVER THE EASTERN US WILL WEAKEN AND QUICKLY MOVE TOWARDS THE NE DURING THIS PERIOD. MEANWHILE...THE JET MAX OVER THE WEST WILL CONTINUE TO DIVE SOUTH INTO THE SW US CAUSING LOW PRESSURE TO FORM AND DEEPEN AS IT MOVES INTO THE PLAINS BY THE END OF THE PERIOD. ...EASTERN US... THE COLD FRONT OVER THE EASTERN US WEAKENS AS THE JET MAX RIDES UP THE LONG WAVE RIDGE OVER THE EAST COAST. AS THE FRONT ENTERS THE REGION IT WILL ENCOUNTER INCREASINGLY STABLE AIR. WEAK INSTABILITY AND STRONG FORCING AT 850MB WILL CAUSE ISOLATED CONVECTION ALONG THE FRONT. FORCING WILL BE STRONG AS A LLJ OF UP TO 70KTS MOVES OVER NJ. AN ISOLATED SEVERE WIND GUST IS POSSIBLE AT THE BEGINNING OF THE PERIOD IN THIS AREA. THE GREATEST INSTABILITY WILL BE IN THE SE US WHERE THERE IS A LACK OF A LIFTING MECHANISM. ISOLATED THUNDERSTORMS BELOW SEVERE LEVELS CAN BE EXPECTED IN THIS AREA. ...PORTIONS OF THE CENTRAL PLAINS... A WARM FRONT WILL MOVE OUT INTO THE PLAINS AHEAD OF THE LOW PRESSURE MOVING OUT OF THE WESTERN US. WEAK INSTABILITY AND WEAK FORCING OVER THE WARM FRONT WILL PROVIDE EARLY MORNING THUNDERSTORMS ALONG AND AHEAD OF THE WARM FRONT AS IT MOVES TOWARDS WI. ...WESTERN US... ISOLATED CONVECTION WILL OCCUR OVER SOME OF THE HIGHER TERRAIN IN THE WEST. A COLD POCKET AT 500MB WITH TEMPERATURES BELOW-30C ALONG WITH WEAK MECHANICAL LIFTING WILL SUPPORT WEAK THUNDERSTORMS/THUNDERSNOW DURING THE PERIOD. ..AFWA.. 03/09/2006  From SWODY2 at goshenarc.org Fri Mar 10 17:27:16 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 12:27:16 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310172940.5CF7BD46A3@mail.goshen.edu> ACUS02 KWNS 101726 SWODY2 SPC AC 101726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY AND SRN PLAINS... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Fri Mar 10 20:13:34 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 15:13:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310201550.01A82D4735@mail.goshen.edu> ACUS02 KWNS 102013 SWODY2 SPC AC 102012 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0212 PM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS VALLEY AND SRN PLAINS... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Fri Mar 10 20:25:12 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 10 Mar 2006 15:25:12 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060310202738.56771D4565@mail.goshen.edu> ACUS02 KWNS 102024 SWODY2 SPC AC 102023 DAY 2 CONVECTIVE OUTLOOK RESENT 2 NWS STORM PREDICTION CENTER NORMAN OK 0223 PM CST FRI MAR 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND MS VALLEY... ...SRN PLAINS/MS VALLEY... A STRONG LOW-LEVEL JET WILL DEVELOP TONIGHT ACROSS THE MS VALLEY AS BROAD SOUTHWEST FLOW CONTINUES IN PLACE ACROSS THE ERN HALF OF THE CONUS. 850 MB FLOW OF 40 TO 50 KT WILL TRANSPORT LOW-LEVEL MOISTURE QUICKLY NWD TONIGHT INTO SATURDAY WITH SFC DEWPOINTS IN THE UPPER 60S TO LOWER 70S F REACHING SE MO AND SRN IL DURING THE DAY. THIS WILL CREATE A BROAD WARM SECTOR BY LATE SATURDAY AFTERNOON CREATING A POTENTIAL FOR SEVERE STORMS OVER A LARGE AREA. A FEW SEVERE STORMS WILL BE POSSIBLE IN THE AFTERNOON ACROSS TN...MS AND LA DUE TO LOW-LEVEL CONVERGENCE AND SFC HEATING. HOWEVER...THE GREATEST THREAT OF SEVERE WEATHER WILL BE ACROSS THE MID TO UPPER MS VALLEY AS A 100 KT MID-LEVEL JET EJECTS ENEWD INTO THE REGION SATURDAY AND SATURDAY NIGHT. AS THE JET APPROACHES SATURDAY AFTERNOON LARGE-SCALE ASCENT WILL INCREASE OVER THE SRN PLAINS AND MS VALLEY BY AFTERNOON. AS A RESULT...STORM INITIATION MAY FIRST OCCUR DURING THE AFTERNOON ACROSS EAST TX AND WRN AR EAST OF A DRYLINE AS SUGGESTED BY THE GFS. MODEL CONSENSUS RAPIDLY EXPANDS CONVECTION NNEWD ACROSS ERN MO AND CNTRL IL DURING THE EVENING. CONFIDENCE IN THIS SCENARIO IS INCREASING DUE TO THE MODELS BECOMING IN BETTER AGREEMENT AT 12Z. FORECAST SOUNDINGS ACROSS THE REGION SATURDAY EVENING SHOW MODERATELY UNSTABLE AIR IN PLACE WITH 0-6 KM SHEAR VALUES INCREASING INTO THE 60 TO 80 KT RANGE AS THE MID-LEVEL JET NOSES INTO THE REGION. THIS SUGGESTS SUPERCELLS WILL BE LIKELY WITH DISCRETE STORMS ESPECIALLY EARLY IN THE DEVELOPMENT OF THE MCS BEFORE STORM COVERAGE BECOMES WIDESPREAD. LARGE HAIL...WIND DAMAGE AND AN ISOLATED TORNADO THREAT WILL BE POSSIBLE WITH SUPERCELLS THAT INITIATE. IN ADDITION...FORECAST INSTABILITY ACROSS THE SRN PLAINS AND OZARK REGION AND STEEPENING LAPSE RATES ASSOCIATED WITH THE APPROACHING MID-LEVEL JET SUGGEST VERY LARGE HAIL WILL BE POSSIBLE. ALTHOUGH A SEVERE WEATHER THREAT SHOULD CONTINUE OVERNIGHT AS THE MCS MATURES AND MOVES SLOWLY ENEWD...STORM INTENSITY SHOULD GRADUALLY DECREASE DUE TO WEAKENING INSTABILITY. ..BROYLES.. 03/10/2006  From SWODY2 at goshenarc.org Sat Mar 11 06:08:37 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 01:08:37 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311061051.91BC2D4735@mail.goshen.edu> ACUS02 KWNS 110608 SWODY2 SPC AC 110607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1207 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS SUN AFT/EVE ACROSS MUCH OF THE MIDDLE MISSISSIPPI VALLEY...FOR A POSSIBLE OUTBREAK OF SEVERE STORMS...INCLUDING SUPERCELLS WITH POTENTIAL FOR ISOLATED STRONG TORNADOES.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA...FROM EASTERN PORTIONS OF THE CNTRL/SRN PLAINS THRU THE OHIO VALLEY.... SEVERAL SIGNIFICANT SHORT WAVE IMPULSES CONTINUE TO PROGRESS THROUGH A BROAD/DEEP COLD UPPER TROUGH...WHICH NOW ENCOMPASSES MUCH OF THE WESTERN AND CENTRAL STATES. STRONGEST OF THESE IMPULSES/JET STREAKS NOW APPEARS TO BE DIGGING INTO BASE OF UPPER TROUGH NEAR THE SOUTHERN CALIFORNIA COAST...AND IS STILL PROGGED BY MOST MODEL GUIDANCE TO NOSE INTO THE SOUTHERN ROCKIES BY 12Z SUNDAY. MODELS SUGGEST THIS FEATURE WILL CONTINUE TO LIFT OUT...ACROSS THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY...SUNDAY/SUNDAY NIGHT. THIS IS PROGGED TO OCCUR IN PHASE WITH A STRONG SUBTROPICAL JET STREAK...WHICH IS EXPECTED TO NOSE ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY...AND BULK OF UPPER TROUGH IS FORECAST TO BEGIN LIFTING OUT OF THE WESTERN STATES. VARIABILITY STILL EXISTS AMONG SOME MODELS CONCERNING THE STRENGTH OF SURFACE CYCLOGENESIS TO OCCUR IN THE LEE OF THE CENTRAL ROCKIES. HOWEVER...WHILE MOST SUBSTANTIAL DEEPENING MAY NOT OCCUR UNTIL MONDAY ACROSS THE EASTERN CANADIAN PROVINCES...IT NOW APPEARS MOST LIKELY THAT A SUB 1000 MB SURFACE LOW WILL DEVELOP BY EARLY SUNDAY ACROSS THE CENTRAL HIGH PLAINS...BEFORE TRACKING NORTHEASTWARD INTO THE GREAT LAKES REGION BY 12Z MONDAY. REGARDLESS...WITH 70F+ DEW POINTS NOW PRESENT ACROSS MUCH OF THE GULF OF MEXICO...AND A SIGNIFICANT RETURN FLOW ALREADY UNDERWAY INTO THE SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY...A BROAD VERY MOIST AND POTENTIALLY MODERATELY UNSTABLE WARM SECTOR IS EXPECTED ACROSS THE CENTRAL STATES BY SUNDAY AFTERNOON. AS FLOW FIELDS STRENGTHEN AND VERTICAL SHEAR PROFILES INCREASE WITHIN THIS WARM SECTOR...THE ENVIRONMENT IS EXPECTED TO BECOME SUPPORTIVE OF AN OUTBREAK OF SEVERE STORMS WITH LARGE HAIL/WIND DAMAGE AND TORNADOES. RISK AREA WILL INCLUDE METROPOLITAN KANSAS CITY/ST. LOUIS AND LITTLE ROCK LATE SUNDAY AFTERNOON...EXTENDING EASTWARD INTO INDIANAPOLIS/MEMPHIS SUNDAY EVENING...POSSIBLY THE LOUISVILLE/CINCINNATI AND CLEVELAND AREAS SUNDAY NIGHT. ...EAST CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY... WHILE CONSIDERABLE CONVECTION ASSOCIATED WITH A LEAD SHORT WAVE IMPULSE MAY BE ONGOING AT 12Z SUNDAY ACROSS THE LOWER OHIO VALLEY ...MUCH OF THE EAST CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY IS EXPECTED TO BE RELATIVE FREE OF CONVECTION/PRECIPITATION. WITH INSOLATION...STEEP MID-LEVEL LAPSE RATES ON NOSE OF RETURNING ELEVATED MIXED LAYER...AND SURFACE DEW POINTS IN THE 60S...SHOULD CONTRIBUTE TO MIXED LAYER CAPE ON THE ORDER OF 2000 J/KG IN SURFACE WARM SECTOR. THIS WILL EXIST EAST OF DRY LINE...LIKELY TO TRAIL SOUTH OF SURFACE LOW CENTER ACROSS NORTHEAST KANSAS BY LATE AFTERNOON...AND SOUTH OF WARM FRONT...LIKELY TO EXTEND EAST OF LOW INTO THE LOWER GREAT LAKES REGION. THOUGH DETAILS OF SURFACE FEATURES ARE STILL UNCERTAIN...CAPPING WITHIN WARM SECTOR SEEMS LIKELY TO BE WEAK ENOUGH FOR SCATTERED CONVECTIVE DEVELOPMENT IN RESPONSE TO FORCING ASSOCIATED WITH PEAK HEATING/BROAD LOW-LEVEL WARM ADVECTION AND DIFLUENT UPPER FLOW REGIME. SUPERCELLS COULD BECOME FAIRLY NUMEROUS BY LATE SUNDAY AFTERNOON...PARTICULARLY FROM PARTS OF EASTERN KANSAS THROUGH MISSOURI AND MUCH OF ARKANSAS. 30 TO 50 KT SOUTHERLY LOW-LEVEL JET ACROSS THIS REGION WILL CONTRIBUTE TO LARGE LOW-LEVEL HODOGRAPHS BENEATH STRONG WEST SOUTHWESTERLY UPPER FLOW. A FEW TORNADOES APPEAR LIKELY...SOME OF WHICH COULD BECOME STRONG. OTHERWISE...LARGE HAIL/DAMAGING WIND GUSTS WILL ALSO ACCOMPANY STRONGER STORMS...WHICH SHOULD DEVELOP INTO ILLINOIS EARLY SUNDAY EVENING. ...OHIO VALLEY... INTENSIFYING SOUTHERLY LOW-LEVEL JET AND FORCING ASSOCIATED WITH PRIMARY UPPER IMPULSE...EAST SOUTHEAST OF SURFACE LOW...ARE EXPECTED TO SUPPORT ORGANIZING SQUALL LINE SUNDAY EVENING ACROSS PARTS OF THE SOUTHERN GREAT LAKES REGION AND LOWER OHIO VALLEY. ACTIVITY WILL CONTINUE EASTWARD THROUGH MUCH OF THE REMAINDER OF THE OHIO VALLEY SUNDAY NIGHT/EARLY MONDAY...WITHIN 50+ KT MEAN FLOW REGIME. THIS WILL SUPPORT CONTINUING SEVERE POTENTIAL... PRIMARILY IN THE FORM OF DAMAGING WINDS. ..KERR.. 03/11/2006  From SWODY2 at goshenarc.org Sat Mar 11 17:24:42 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 12:24:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311172657.4F8BBD4C12@mail.goshen.edu> ACUS02 KWNS 111725 SWODY2 SPC AC 111724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF TX...OK...LA...AR...MS...TN...MO...IA...IL...KY AND TN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS...LOWER MS VALLEY...TN VALLEY...UPPER OH VALLEY AND UPPER MIDWEST... ...MS VALLEY/SRN PLAINS... A BROAD UPPER-LEVEL TROUGH WILL CONTINUE IN PLACE ACROSS THE WRN U.S. WITH SOUTHWEST FLOW PRESENT ACROSS THE GREAT PLAINS AND MS VALLEY TONIGHT INTO SUNDAY. A 100 KT MID-LEVEL JET IS FORECAST TO MOVE INTO THE PLAINS STATES SUNDAY AND SUNDAY NIGHT. SHORTWAVE ACTIVITY EMBEDDED IN THE BROAD SOUTHWEST FLOW REGIME WILL CAUSE LARGE-SCALE ASCENT TO INCREASE ACROSS THE REGION BY AFTERNOON. THIS COMBINED WITH A BROAD WARM SECTOR WILL PROVIDE THE INGREDIENTS NECESSARY FOR A WIDESPREAD SEVERE WEATHER THREAT SUNDAY AND SUNDAY NIGHT. MODEL FORECASTS ARE RELATIVELY CONSISTENT...INITIATING WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE WRN EDGE OF THE LOW-LEVEL MOISTURE GRADIENT SUNDAY AFTERNOON. INITIATION WOULD MOST LIKELY OCCUR WHERE SFC HEATING IS MAXIMIZED WITH SEVERAL STORM CLUSTERS DEVELOPING NEAR A SFC LOW ACROSS NRN MO EXTENDING SSWWD ACROSS WRN...ERN OK AND NE TX NEAR A DRYLINE. AS THE STORMS MOVE EWD INTO THE STRONGER LOW-LEVEL FLOW AND GREATER INSTABILITY...SEVERAL MCS CLUSTERS SHOULD ORGANIZE AND TRACK EWD ACROSS THE MODERATE RISK AREA. FORECAST SOUNDINGS ACROSS THE REGION FROM 21Z TO 03Z SUNDAY AFTERNOON AND EVENING SHOW 0-6 KM SHEAR VALUES RANGING FROM AROUND 60 KT ACROSS THE ARKLATEX TO ABOUT 80 KT IN THE LOWER OH VALLEY. CONSIDERING MODERATE INSTABILITY IS FORECAST ACROSS A BROAD WARM SECTOR...THE ENVIRONMENT APPEARS FAVORABLE FOR SUPERCELLS ACROSS THE ENTIRE REGION. SUPERCELLS WILL BE THE MOST LIKELY MODE WHERE STORMS REMAIN DISCRETE WITH BOW ECHOES AND MULTICELL STORMS LIKELY IN STORM CLUSTERS OF LINEAR ORIENTATION. LOW-LEVEL SHEAR PROFILES APPEAR FAVORABLE FOR TORNADOES WITH THE GREATEST TORNADO THREAT LIKELY IN AREAS WHERE THE INSTABILITY IS MAXIMIZED. THE STRONG VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE HAIL WITH VERY LARGE HAIL POSSIBLE WITH THE STRONGER SUPERCELL STORMS IN THE LATE AFTERNOON AND EARLY EVENING. WIND DAMAGE WILL BE LIKELY ESPECIALLY AS STORM CLUSTERS ORGANIZE INTO LINES DURING THE EVENING HOURS. A LARGE LINEAR MCS SHOULD DEVELOP AND CONTINUE EWD ACROSS THE MS RIVER AND UPPER OH VALLEY. ALTHOUGH STORM INTENSITY SHOULD GRADUALLY DECREASE OVERNIGHT...AT LEAST AN ISOLATED SEVERE WEATHER THREAT SHOULD CONTINUE LATE SUNDAY NIGHT DUE TO THE BROAD WARM SECTOR IN PLACE. ...CNTRL PLAINS... BROAD SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE PLAINS STATES AS A SFC LOW ORGANIZES ALONG A FRONTAL BOUNDARY FROM NRN MO EXTENDING WWD ACROSS SRN NEB AND NRN KS LATE SUNDAY AFTERNOON. LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION AS SFC TEMPS WARM DURING THE DAY. SUPERCELLS WILL BE POSSIBLE DUE TO THE STRONG VERTICAL SHEAR IN PLACE. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK...FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES. AS A RESULT...A FEW OF THE STORMS COULD PRODUCE LARGE HAIL AND/OR WIND DAMAGE DURING THE LATE AFTERNOON OR EARLY EVENING HOURS WITH THE SEVERE WEATHER THREAT LIKELY DECREASING DURING THE EVENING ON SUNDAY DUE TO DECREASING INSTABILITY. ..BROYLES.. 03/11/2006  From SWODY2 at goshenarc.org Sat Mar 11 17:31:47 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Mar 2006 12:31:47 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060311173401.25238D4932@mail.goshen.edu> ACUS02 KWNS 111731 SWODY2 SPC AC 111730 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST SAT MAR 11 2006 VALID 121200Z - 131200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF TX...OK...LA...AR...MS...TN...MO...IA...IL...KY AND TN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS...LOWER MS VALLEY...TN VALLEY...UPPER OH VALLEY AND UPPER MIDWEST... CORRECTED FOR MINOR WORDING ...MS VALLEY/SRN PLAINS... A BROAD UPPER-LEVEL TROUGH WILL CONTINUE IN PLACE ACROSS THE WRN U.S. WITH SOUTHWEST FLOW PRESENT ACROSS THE GREAT PLAINS AND MS VALLEY TONIGHT INTO SUNDAY. A 100 KT MID-LEVEL JET IS FORECAST TO MOVE INTO THE PLAINS STATES SUNDAY AND SUNDAY NIGHT. SHORTWAVE ACTIVITY EMBEDDED IN THE BROAD SOUTHWEST FLOW REGIME WILL CAUSE LARGE-SCALE ASCENT TO INCREASE ACROSS THE REGION BY AFTERNOON. THIS COMBINED WITH A BROAD WARM SECTOR WILL PROVIDE THE INGREDIENTS NECESSARY FOR A WIDESPREAD SEVERE WEATHER THREAT SUNDAY AND SUNDAY NIGHT. MODEL FORECASTS ARE RELATIVELY CONSISTENT...INITIATING WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE WRN EDGE OF THE LOW-LEVEL MOISTURE GRADIENT SUNDAY AFTERNOON. INITIATION WOULD MOST LIKELY OCCUR WHERE SFC HEATING IS MAXIMIZED WITH SEVERAL STORM CLUSTERS DEVELOPING NEAR A SFC LOW ACROSS NRN MO EXTENDING SSWWD ACROSS WRN AR...ERN OK AND NE TX NEAR A DRYLINE. AS THE STORMS MOVE EWD INTO THE STRONGER LOW-LEVEL FLOW AND GREATER INSTABILITY...SEVERAL MCS CLUSTERS SHOULD ORGANIZE AND TRACK EWD ACROSS THE MODERATE RISK AREA. FORECAST SOUNDINGS ACROSS THE REGION FROM 21Z TO 03Z SUNDAY AFTERNOON AND EVENING SHOW 0-6 KM SHEAR VALUES RANGING FROM AROUND 60 KT ACROSS THE ARKLATEX TO ABOUT 80 KT IN THE LOWER OH VALLEY. CONSIDERING MODERATE INSTABILITY IS FORECAST ACROSS A BROAD WARM SECTOR...THE ENVIRONMENT APPEARS FAVORABLE FOR SUPERCELLS ACROSS THE ENTIRE REGION. SUPERCELLS WILL BE THE MOST LIKELY MODE WHERE STORMS REMAIN DISCRETE WITH BOW ECHOES AND MULTICELL STORMS LIKELY IN STORM CLUSTERS OF LINEAR ORIENTATION. LOW-LEVEL SHEAR PROFILES APPEAR FAVORABLE FOR TORNADOES WITH THE GREATEST TORNADO THREAT LIKELY IN AREAS WHERE THE INSTABILITY IS MAXIMIZED. THE STRONG VERTICAL SHEAR AND STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE HAIL WITH VERY LARGE HAIL POSSIBLE WITH THE STRONGER SUPERCELL STORMS IN THE LATE AFTERNOON AND EARLY EVENING. WIND DAMAGE WILL BE LIKELY ESPECIALLY AS STORM CLUSTERS ORGANIZE INTO LINES DURING THE EVENING HOURS. A LARGE LINEAR MCS SHOULD DEVELOP AND CONTINUE EWD ACROSS THE MS RIVER AND UPPER OH VALLEY. ALTHOUGH STORM INTENSITY SHOULD GRADUALLY DECREASE OVERNIGHT...AT LEAST AN ISOLATED SEVERE WEATHER THREAT SHOULD CONTINUE LATE SUNDAY NIGHT DUE TO THE BROAD WARM SECTOR IN PLACE. ...CNTRL PLAINS... BROAD SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE PLAINS STATES AS A SFC LOW ORGANIZES ALONG A FRONTAL BOUNDARY FROM NRN MO EXTENDING WWD ACROSS SRN NEB AND NRN KS LATE SUNDAY AFTERNOON. LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION AS SFC TEMPS WARM DURING THE DAY. SUPERCELLS WILL BE POSSIBLE DUE TO THE STRONG VERTICAL SHEAR IN PLACE. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK...FORECAST SOUNDINGS SHOW STEEP MID-LEVEL LAPSE RATES. AS A RESULT...A FEW OF THE STORMS COULD PRODUCE LARGE HAIL AND/OR WIND DAMAGE DURING THE LATE AFTERNOON OR EARLY EVENING HOURS WITH THE SEVERE WEATHER THREAT LIKELY DECREASING DURING THE EVENING ON SUNDAY DUE TO DECREASING INSTABILITY. ..BROYLES.. 03/11/2006  From SWODY2 at goshenarc.org Sun Mar 12 06:13:41 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Mar 2006 01:13:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060312061551.E0CA4D46B5@mail.goshen.edu> ACUS02 KWNS 120611 SWODY2 SPC AC 120610 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1210 AM CST SUN MAR 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY ACROSS MUCH OF THE OH/TN VALLEYS...THE MID ATLANTIC COAST STATES...AND PARTS OF THE CNTRL/ERN GULF STATES.... A VERY STRONG MID/UPPER JET STREAK CONTINUES TO NOSE AROUND THE BASE OF A BROAD COLD UPPER TROUGH...WHICH ENCOMPASSES MUCH OF THE WESTERN UNITED STATES. MODELS CONTINUE TO SUGGEST THAT THE MOST SIGNIFICANT IMPULSE EMBEDDED WITHIN THIS FEATURE WILL LIFT OUT OF THE SOUTHERN ROCKIES TODAY. AS THIS OCCURS...THE BROADER SCALE TROUGHING WILL FOLLOW SUIT. POLAR TROUGH IS PROGGED TO REMAIN IN PHASE WITH THE SUBTROPICAL STREAM...AND PROGRESS INTO THE EASTERN HALF OF THE NATION BY LATE MONDAY NIGHT OR EARLY TUESDAY. A SIGNIFICANT SURFACE CYCLONE ACCOMPANYING UPPER SYSTEM IS EXPECTED TO APPROACH THE GREAT LAKES REGION BY 12Z MONDAY...BEFORE CONTINUING TO DEEPEN AND LIFT THROUGH THE EASTERN CANADIAN PROVINCES. A COLD INTRUSION IN ITS WAKE WILL BEGIN TO OVERSPREAD MOST THE NATION EAST OF THE ROCKIES...LIKELY ADVANCING THROUGH ALL BUT EASTERN GULF AND SOUTH ATLANTIC COASTAL AREAS BY 12Z TUESDAY. IN ADVANCE OF THE COLD FRONT...AN INFLUX OF SEASONABLY HIGH BOUNDARY LAYER MOISTURE OFF THE GULF OF MEXICO AND WESTERN ATLANTIC WILL OCCUR THROUGH MUCH OF THE EASTERN STATES. THIS WILL CONTRIBUTE TO POTENTIALLY UNSTABLE ENVIRONMENT...WHICH SHOULD BE SUPPORTIVE OF WIDESPREAD CONVECTIVE DEVELOPMENT...AND THE CONTINUATION OF A SEVERE WEATHER OUTBREAK ALREADY UNDERWAY ACROSS PARTS OF THE MIDDLE MISSISSIPPI VALLEY. ...GREAT LAKES/OHIO AND TN VALLEYS INTO MID ATLANTIC STATES... WHILE SUBSTANTIAL SEVERE POTENTIAL SEEMS LIKELY TO CONTINUE INTO THE NORTHEAST QUARTER OF THE NATION MONDAY...UNCERTAINTIES BEGIN TO ARISE BY THE BEGINNING OF THE PERIOD WHICH COULD TEMPER THREAT...AT LEAST IN TERMS OF NUMBERS OF "SIGNIFICANT" SEVERE EVENTS. A SQUALL LINE MAY BE ONGOING ACROSS THE LOWER OHIO VALLEY AT 12Z MONDAY...WHICH SEEMS LIKELY TO WEAKEN AS IT BEGINS TO OUTRUN PRIMARY UPPER TROUGH AND BETTER PRE-FRONTAL INSTABILITY. THE SURFACE WARM SECTOR WILL BE BROAD...WITH 60F+ SURFACE DEW POINTS WIDESPREAD EAST OF THE MISSISSIPPI VALLEY...LIKELY ACROSS ALL BUT NORTHERN NEW ENGLAND. HOWEVER...SUBSTANTIAL CLOUD COVER MAY LIMIT INSOLATION...AND NORTHEASTWARD ADVECTION OF ELEVATED MIXED LAYER OUT OF THE PLATEAU REGION SEEMS LIKELY TO BECOME SUPPRESSED BY EARLY MONDAY. ALL OF THIS IS EXPECTED TO LIMIT PEAK MIXED LAYER INSTABILITY TO AROUND 1000 J/KG...IN A RELATIVELY NARROW CORRIDOR AHEAD OF COLD FRONT AS IT ADVANCES TOWARD THE APPALACHIANS MONDAY AFTERNOON...PERHAPS SOUTH OF WARM FRONT...ACROSS EASTERN MARYLAND/PENNSYLVANIA. STILL...INSTABILITY SHOULD BE SUFFICIENT IN STRONGLY SHEARED REGIME TO SUPPORT SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND AT LEAST MARGINALLY SEVERE HAIL. ISOLATED SUPERCELLS WILL ALSO BE POSSIBLE...ALONG WITH POTENTIAL FOR TORNADOES. STORMS SEEM LIKELY TO DEVELOP TO THE LEE OF THE NORTH CENTRAL APPALACHIANS...AHEAD OF WEAKENING CONVECTIVE LINE...BY MONDAY AFTERNOON. THIS ACTIVITY SHOULD EVENTUALLY DEVELOP EASTWARD TOWARD NORTHERN MID ATLANTIC COASTAL AREAS...BUT SEVERE THREAT IS EXPECTED TO DIMINISH AS CONVECTION OVERSPREADS MARINE LAYER IN IMMEDIATE VICINITY OF COASTAL AREAS INTO SOUTHERN NEW ENGLAND. OTHERWISE...PRE-FRONTAL LINES OF STRONG/SEVERE STORMS ARE EXPECTED TO DEVELOP THROUGH THE OHIO/TENNESSEE VALLEYS DURING THE PEAK HEATING HOURS. ACTIVITY MAY DEVELOP IN A MORE SCATTERED FASHION AS FAR SOUTH AS THE CENTRAL/EASTERN GULF STATES...BUT DIMINISHING TRENDS ARE EXPECTED BY MONDAY EVENING EAST OF THE CENTRAL/SOUTHERN APPALACHIANS. ..KERR.. 03/12/2006  From SWODY2 at goshenarc.org Sun Mar 12 17:31:50 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Mar 2006 12:31:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060312173358.D08E0D4961@mail.goshen.edu> ACUS02 KWNS 121731 SWODY2 SPC AC 121731 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1131 AM CST SUN MAR 12 2006 VALID 131200Z - 141200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER SERN INDIANA...MUCH OF OH...WRN PA...WRN/CNTRL WV...AND CNTRL/ERN KY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE LOWER MS VALLEY/SERN STATES...AND PARTS OF THE MID ATLANTIC REGION AND SRN NEW ENGLAND... ...SYNOPSIS... VERY DYNAMIC AND PROGRESSIVE UPPER AIR PATTERN IS FORECAST TO CONTINUE INTO DAY 2 OVER THE ERN HALF OF THE NATION. UPPER LOW IS EXPECTED TO BE OVER THE UPPER MS VALLEY AT THE START OF THE PERIOD..AND MOVE ENEWD ACROSS THE NRN GREAT LAKES BY LATE AFTERNOON CONTINUING INTO ERN ONTARIO BY 14/12Z. THE UPPER SYSTEM IS FORECAST TO CONTINUE INTENSIFYING DURING THE PERIOD WITH 12-HR 500 MB HEIGHT FALLS INCREASING TO 240-270M...IN RESPONSE TO 120-130 KT MID LEVEL JET STREAK ACCELERATING ACROSS THE MID MS VALLEY AND GREAT LAKES REGION. AT THE SURFACE...A LOW OVER THE ERN IA/NWRN IL AREA AT 12Z IS FORECAST DEEPEN AS IT TRACKS NEWD TOWARD NRN LOWER MI BY LATE AFTERNOON REACHING WRN QUEBEC BY THE END OF THE PERIOD. A STRONG COLD FRONT EXTENDING SWD FROM THE LOW ALONG A CENTRAL IL..CENTRAL AR..S CENTRAL TX LINE AT 12Z WILL MOVE EWD TO A CENTRAL OH..MIDDLE TN..SWRN LA LINE BY 00Z...CONTINUING OVERNIGHT REACHING NEW ENGLAND...THE MIDDLE ATLANTIC COAST...THEN SWWD ACROSS CENTRAL SC..NWRN FL INTO THE NORTH CENTRAL GULF BY THE END OF PERIOD. A WARM FRONT WILL LIFT NWD ACROSS THE GREAT LAKES IN ADVANCE OF THE SURFACE LOW...BUT ITS NWD MOVEMENT ACROSS THE COASTAL PARTS OF THE MID ATLANTIC STATES MAY BE INHIBITED BY FLOW OFF COOL MARINE LAYER. ...OH VALLEY AND LOWER GREAT LAKES INTO MID ATLANTIC STATES... MODEL GUIDANCE FROM THE 12Z ETA AND GFS...09Z ETAKF CONTROL RUN FROM SREF...AND 00Z HIGH RESOLUTION WRF-NMM ALL INDICATE A PRE-COLD FRONTAL LINE OF STRONG/SEVERE CONVECTION WILL BE ONGOING AT THE START OF THE PERIOD FROM INDIANA INTO WRN PARTS OF KY/TN AND SRN AR. THIS CONVECTION WILL BE MOVING EWD THROUGH A BROAD WARM SECTOR WHERE STRONG SSWLY LOW LEVEL WINDS ARE ADVECTING MOISTURE ACROSS THE OH VALLEY TOWARD THE LOWER GREAT LAKES. SURFACE DEW POINTS WILL GENERALLY BE IN THE 55-60F RANGE ACROSS NRN PARTS OF THE WARM SECTOR INCREASING TO 60-65F FROM PARTS OF THE OH RIVER SWD. RESULTANT EXTENSIVE CLOUD COVER SPREADING DOWNSTREAM FROM THE MORNING CONVECTION WILL LIKELY INHIBIT DIURNAL HEATING ACROSS PARTS OF THE OH VALLEY/LOWER GREAT LAKES. COUPLED WITH MODEST MID LEVEL LAPSE RATES OVER THE WARM SECTOR...IT APPEARS THAT MLCAPE WILL BE LIMITED TO MAXIMUM OF VALUES OF 500-1000 J/KG. STRONG DEEP LAYER VERTICAL SHEAR /50-60 KT IN THE LOWEST 6 KM/...CLOCKWISE TURNING LOW LEVEL HODOGRAPHS AND ASSOCIATED 150-250 M2/S2 0-1 KM SRH...AND INCREASING ISALLOBARIC FORCING WILL ENHANCE QUASI-LINEAR CONVECTIVE ORGANIZATION WITH LEADING BAND SPREADING EWD THROUGH THE DAY. THIS WILL MAINTAIN THREAT FOR PRIMARILY WIDESPREAD DAMAGING WIND GUSTS AND MARGINAL HAIL...ALTHOUGH ISOLATED TORNADOES WILL ALSO BE POSSIBLE ASSOCIATED WITH EMBEDDED SUPERCELLS OR ANY DISCRETE CELLS THAT MAY DEVELOP GIVEN THE STRONG LOW LEVEL SHEAR. IN ADDITION...THERE IS POTENTIAL FOR ADDITIONAL STORMS TO DEVELOP NEAR THE COLD FRONT DURING THE AFTERNOON IF AIR MASS RECOVERY OCCURS IN THE WAKE OF THE INITIAL CONVECTION. THIS MAY RESULT IN MULTIPLE BANDS OF SEVERE STORMS PROGRESSING EWD ACROSS THIS REGION DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH LOW LEVEL MOISTURE/INSTABILITY IS FORECAST TO DIMINISH WITH EASTWARD EXTEND INTO WRN/CENTRAL PARTS OF NY/PA/WV...THE VERY STRONG WIND FIELDS AT ALL LEVELS COUPLED WITH THE EWD SURGE OF THE COLD FRONT SUGGESTS POTENTIAL FOR LOW-TOP SQUALL LINE SEGMENTS TO SPREAD RAPIDLY EWD...CONTINUING A THREAT FOR DAMAGING WIND GUSTS FROM THE EVENING INTO THE OVERNIGHT HOURS. GIVEN THE UNCERTAINTY IN THE NWD PROGRESSION OF WARM FRONT ACROSS THE MID ATLANTIC REGION AND NEW ENGLAND...POTENTIAL FOR DAMAGING WINDS MAY DIMINISH WITH NEWD EXTENT OVER THIS AREA AS STORMS BECOME INCREASINGLY ELEVATED NORTH/EAST OF THE WARM FRONT..ALTHOUGH MARGINAL HAIL MAY PERSIST WITH ELEVATED CELLS. ...TN/LOWER MS VALLEYS INTO SRN APPALACHIANS... STRONG DEEP LAYER SHEAR WILL EXTEND SWD ACROSS THIS REGION...AND INCREASING MOISTURE/INSTABILITY COUPLED WITH A WEAK CAP WILL PROMOTE EWD DEVELOPMENT OF STRONG/SEVERE STORMS ACROSS PARTS OF THE SERN STATES. THIS ACTIVITY IS EXPECTED TO SPREAD EWD TOWARD THE SRN APPALACHIANS DURING THE EVENING HORUS BEFORE DIMINISHING BY 06-09Z. DAMAGING WINDS AND HAIL WILL BE THE PRIMARY THREATS. ..WEISS.. 03/12/2006  From SWODY2 at goshenarc.org Mon Mar 13 06:05:04 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 13 Mar 2006 01:05:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060313060800.715CBD43A2@mail.goshen.edu> ACUS02 KWNS 130605 SWODY2 SPC AC 130604 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1204 AM CST MON MAR 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... CONVECTIVE POTENTIAL IS EXPECTED TO DIMINISH CONSIDERABLY BY THE BEGINNING OF THIS FORECAST PERIOD. MODELS SUGGEST BROAD UPPER TROUGH WILL ENCOMPASS MUCH OF THE EASTERN U.S. BY 12Z TUESDAY... WITH ASSOCIATED DEEP LOW/MID-LEVEL CYCLONE SLOWLY SHIFTING INTO WESTERN QUEBEC. AS UPPER TROUGH AXIS DEVELOPS OFF THE ATLANTIC COAST LATER TUESDAY INTO EARLY WEDNESDAY...MID-LEVEL CYCLONE IS PROGGED TO CONTINUE EASTWARD INTO THE ST. LAWRENCE VALLEY. THIS WILL BE ACCOMPANIED BY SIGNIFICANT SECONDARY SURFACE CYCLOGENESIS ...WHICH MAY COMMENCE AS EARLY AS TUESDAY MORNING OFF THE NORTH ATLANTIC COAST...BEFORE LIFTING INTO THE CANADIAN MARITIMES. IN ITS WAKE... COLD INTRUSION WILL ADVANCE THROUGH THE REMAINDER OF THE ATLANTIC SEABOARD AND SOUTHEAST STATES. UPSTREAM...NEXT SIGNIFICANT SHORT WAVE IMPULSE IS FORECAST TO RAPIDLY PROGRESS INLAND ACROSS THE NORTHERN/CENTRAL CALIFORNIA COAST...THROUGH MUCH OF THE GREAT BASIN BY 12Z WEDNESDAY. THIS WILL BE ACCOMPANIED BY DEVELOPING SURFACE TROUGH IN THE LEE OF THE CENTRAL/SOUTHERN ROCKIES...AND INCREASING WARM ADVECTION FROM GULF COASTAL AREAS THROUGH THE SOUTHERN PLAINS BY LATE IN THE PERIOD. HOWEVER...MOISTURE RETURN IN THE WAKE OF PRIOR FRONTAL PASSAGE IS NOT EXPECTED TO BECOME SUFFICIENT FOR CONVECTIVE DEVELOPMENT... EXCEPT PERHAPS AREAS WEST/SOUTH OF THE LOWER RIO GRANDE VALLEY AND AREAS OFF THE LOWER TEXAS COAST. ...ATLANTIC COAST.. SURFACE COLD FRONT APPEARS LIKELY TO ADVANCE INTO NORTHERN MID ATLANTIC COASTAL AREAS BY AROUND 12Z TUESDAY...AND INTO/ACROSS THE REMAINDER OF THE ATLANTIC COAST BY MIDDAY. ANY THUNDERSTORM ACTIVITY ACROSS NEW ENGLAND IS EXPECTED TO BE BASED ABOVE MARINE LAYER...AND IN ELEVATED LAYER OF MOIST ISENTROPIC ASCENT TO THE NORTH/EAST OF DEVELOPING SURFACE LOW. WITH COLDER AIR ALOFT LAGGING TO THE WEST OF SURFACE COLD FRONT...CAPE WILL BE LIMITED AND RISK OF LARGE HAIL SEEMS SMALL. FARTHER SOUTH...RELATIVELY WARM MID-LEVEL ENVIRONMENT IS ALSO EXPECTED TO MINIMIZE INSTABILITY AHEAD OF COLD FRONT ACROSS THE EASTERN CAROLINAS. WINDOW OF OPPORTUNITY FOR SURFACE HEATING WILL BE LIMITED WITH FRONT EXPECTED TO ADVANCE OFFSHORE BY/OR SHORTLY AFTER 15Z TUESDAY...BUT FORCING MAY STILL BE SUFFICIENT TO SUPPORT NARROW LINE OF CONVECTION BEFORE THIS OCCURS. THIS COULD ENHANCE DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 40-50+ KT MEAN FLOW REGIME...CONTRIBUTING TO AT LEAST SOME POTENTIAL FOR DAMAGING SURFACE GUSTS. ...NORTH CENTRAL PACIFIC COAST INTO NORTHERN GREAT BASIN... STRONG MID-LEVEL COOLING /500 MB COLD CORE BELOW -30C/ IN EXIT REGION OF MID/UPPER JET STREAK WILL CONTRIBUTE TO DESTABILIZATION AS IT NOSES INLAND TUESDAY. THOUGH INSTABILITY SHOULD REMAIN WEAK...THERMODYNAMIC PROFILES ARE EXPECTED TO BE SUPPORTIVE OF SMALL HAIL. BEST POTENTIAL FOR THIS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS SEEMS TO BE NORTHERN CALIFORNIA COASTAL AREAS INTO THE SACRAMENTO VALLEY...WHERE LOW-LEVELS WILL BE WARMER AND MORE MOIST. THREAT ACROSS THIS REGION IS EXPECTED TO DIMINISH AS ONSHORE COMPONENT TO LOW-LEVEL FLOW WEAKENS DURING THE MID TO LATE AFTERNOON. ..KERR.. 03/13/2006  From SWODY2 at goshenarc.org Mon Mar 13 17:23:00 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 13 Mar 2006 12:23:00 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060313172553.DF1AFD4A73@mail.goshen.edu> ACUS02 KWNS 131724 SWODY2 SPC AC 131723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 AM CST MON MAR 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S./MIDDLE ATLANTIC... STRONG UPPER TROUGH OVER THE OH VALLEY WILL HAVE FORCED SFC FRONTAL BOUNDARY EAST OF THE APPALACHIANS LATE IN THE DAY1 PERIOD WITH SFC WIND SHIFT LIKELY NEAR THE DELMARVA COAST BY 12Z TUE MORNING. GIVEN THE LARGE SCALE HEIGHT FALLS AND STRENGTH OF VERTICAL SHEAR OBSERVED ALONG THE FRONTAL ZONE...IT APPEARS THE MITIGATING FACTOR FOR ORGANIZED SEVERE THUNDERSTORMS WILL BE THE LACK OF SIGNIFICANT BOUNDARY LAYER INSTABILITY ACROSS THE CAROLINAS BEFORE WLY FLOW DEEPENS AND FOCUSED CONVERGENCE SHIFTS OFFSHORE. FORECAST SOUNDINGS ACROSS THIS REGION EARLY IN THE PERIOD SUGGEST PARCELS FEEDING THUNDERSTORM UPDRAFTS MAY BE SOMEWHAT ELEVATED...ROOTED AROUND 950MB AND DRIVEN PARTLY DUE TO WARM ADVECTION. MUCAPE WILL LIKELY HOLD AOB 500J/KG LIMITING HAIL THREAT...WHILE SLIGHTLY ELEVATED PARCELS SUGGEST LOCALLY STRONG WINDS WILL BE THE PRIMARY SEVERE THREAT BEFORE COLD FRONT SWEEPS OFFSHORE. ...NORTHERN/CENTRAL CA... NEXT IN A SERIES OF STRONG SHORTWAVE TROUGHS WILL APPROACH THE WEST COAST EARLY IN THE PERIOD...THEN SHIFT INLAND AS SPEED MAX EJECTS EAST ACROSS CNTRL CA INTO NV BY 00Z/15TH. NORTH OF THIS JET AXIS...VERY COLD MID LEVEL TEMPS...H5 THERMAL TROUGH TO MINUS 32C...WILL STEEPEN LAPSE RATES AND AID CONVECTIVE THERMALS ACROSS PORTIONS OF NRN/CNTRL CA...ESPECIALLY IF PARTIAL SUNSHINE DEVELOPS. COLD...STEEP LAPSE RATE ENVIRONMENT FAVORS HAIL WITH STRONG UPDRAFTS BUT OVERALL INSTABILITY DOES NOT APPEAR SUPPORTIVE OF ANYTHING LARGER THAN MARGINAL SEVERE HAIL. ..DARROW.. 03/13/2006  From SWODY2 at goshenarc.org Tue Mar 14 05:46:23 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 14 Mar 2006 00:46:23 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060314054917.8ECC3D47F7@mail.goshen.edu> ACUS02 KWNS 140547 SWODY2 SPC AC 140546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST MON MAR 13 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... MODELS CONTINUE TO SUGGEST THAT ANOTHER LARGE-SCALE UPPER TROUGH WILL BEGIN TO EVOLVE OFF THE PACIFIC COAST DURING THIS FORECAST PERIOD. DOWNSTREAM BROADER SCALE UPPER FLOW ACROSS THE CENTRAL/EASTERN STATES WILL REMAIN BROADLY CONFLUENT IN THE WAKE OF A DEEP CANADIAN MARITIMES CYCLONE AND ASSOCIATED WESTERN ATLANTIC TROUGH. HOWEVER...MID-LEVEL IMPULSE... NOW PROGRESSING INTO THE NORTH CENTRAL PACIFIC COAST...IS PROGGED TO REMAIN FAIRLY STRONG AS IT PROGRESSES ACROSS THE INTERMOUNTAIN WEST INTO THE MID MISSOURI VALLEY BY 12Z THURSDAY. THIS MAY BE ACCOMPANIED BY A WEAKENING IMPULSE IN THE SUBTROPICAL STREAM...WHICH IS FORECAST TO TOP CREST OF MID/UPPER RIDGE CENTERED NEAR THE YUCATAN PENINSULA. WEAK SURFACE CYCLOGENESIS APPEARS LIKELY TO ACCOMPANY POLAR SHORT WAVE IN THE LEE OF THE CENTRAL ROCKIES THROUGH THE CENTRAL PLAINS/MID MISSOURI VALLEY. HOWEVER...IN WAKE OF PRIOR FRONTAL PASSAGE...DESTABILIZATION IS EXPECTED TO BE INSUFFICIENT FOR THUNDERSTORM ACTIVITY. SURFACE RIDGE ASSOCIATED WITH ONGOING COLD INTRUSION TO THE LEE OF THE ROCKIES WILL BE SLOW TO ERODE/RETREAT ACROSS THE SOUTH CENTRAL/SOUTHEASTERN STATES AND NORTHEASTERN GULF OF MEXICO. BUT...A RETURN FLOW OF MOISTURE IS EXPECTED ABOVE RESIDUAL COLD/STABLE SURFACE LAYER...INTO EAST TEXAS AND THE LOWER MISSISSIPPI VALLEY. THIS SHOULD BE CAPPED THROUGH MUCH OF THE PERIOD BY A RELATIVELY WARM MID-LEVEL ENVIRONMENT BENEATH SUBTROPICAL RIDGE. ...SOUTH CENTRAL STATES... BROAD LOWER/MID TROPOSPHERIC ISENTROPIC ASCENT IS EXPECTED THROUGH MOST OF THE PERIOD ACROSS MUCH OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY. THEN...MOST LIKELY LATE WEDNESDAY NIGHT INTO EARLY THURSDAY...MODELS SUGGEST MID-LEVEL HEIGHT FALLS ASSOCIATED WITH SHEARING SUBTROPICAL IMPULSE ABOVE THIS REGIME COULD SUPPRESS INHIBITION SUFFICIENTLY FOR CONVECTIVE DEVELOPMENT. IF THIS OCCURS...IT NOW SEEMS MORE LIKELY THAT MOST UNSTABLE CAPE WILL REMAIN AT OR BELOW 500 J/KG...WHICH SHOULD PRECLUDE AN APPRECIABLE RISK FOR LARGE HAIL. ...PACIFIC NORTHWEST... SCATTERED THUNDERSTORMS ASSOCIATED WITH COLD UPPER TROUGH MAY APPROACH SHORE WEDNESDAY/WEDNESDAY NIGHT...BUT LARGE-SCALE SUPPORT DOES NOT APPEAR FAVORABLE FOR ACTIVITY TO DEVELOP INLAND BEYOND IMMEDIATE COASTAL AREAS. ..KERR.. 03/14/2006  From SWODY2 at goshenarc.org Tue Mar 14 17:18:09 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 14 Mar 2006 12:18:09 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060314172101.A5D33D4A74@mail.goshen.edu> ACUS02 KWNS 141719 SWODY2 SPC AC 141718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CST TUE MAR 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...EAST TX/LOWER MS VALLEY... LATEST MODEL GUIDANCE MAINTAINS CA UPPER SHORTWAVE TROUGH WILL EJECT EWD ACROSS THE CNTRL ROCKIES AND DEAMPLIFY SOMEWHAT WITHIN WLY FLOW REGIME OVER THE PLAINS LATE IN THE PERIOD. THIS FEATURE WILL AID RETURN FLOW AND WARM ADVECTION ACROSS TX INTO THE LOWER MS VALLEY REGION WHERE GRADUAL AIRMASS DESTABILIZATION IS EXPECTED ABOVE THE BOUNDARY LAYER...ESPECIALLY ALONG ERN FRINGE OF STEEP LAPSE RATE PLUME OFF THE SRN HIGH PLAINS REGION. FORECAST SOUNDINGS SUGGEST BUOYANCY IF PARCELS ARE LIFTED NEAR 850 MB...MUCAPE ROUGHLY ON THE ORDER OF 500 J/KG. ELEVATED CONVECTION WILL LIKELY EVOLVE LATE IN THE PERIOD FROM EAST TX INTO AR AND LA AS SUSTAINED...INCREASINGLY MOIST...SWLY TRAJECTORY ENHANCES ASCENT ATOP COOLER LOW LEVEL AIRMASS. ...PACIFIC NW... ISOLATED THUNDERSTORMS MAY DEVELOP IN ASSOCIATION WITH NEXT SHORTWAVE TROUGH APPROACHING THE PACIFIC NW COAST WEDNESDAY. VERY COLD...STEEP LAPSE RATE ENVIRONMENT...SUGGESTS CONVECTION IS LIKELY...BUT LIGHTNING SHOULD BE LIMITED EXCEPT FOR NEAR THE MARINE LAYER DUE TO MEAGER INSTABILITY INLAND. ..DARROW.. 03/14/2006  From SWODY2 at goshenarc.org Wed Mar 15 05:58:20 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 15 Mar 2006 00:58:20 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060315060109.1074FD4645@mail.goshen.edu> ACUS02 KWNS 150559 SWODY2 SPC AC 150558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 PM CST TUE MAR 14 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS THU AFTN/EVE ACROSS PARTS OF S CNTRL/SE TEXAS AND WRN LA.... MODELS CONTINUE TO INDICATE THAT A BROAD UPPER TROUGH WILL BEGIN TO EVOLVE ACROSS THE EASTERN PACIFIC LATER TODAY INTO 12Z THURSDAY... BEFORE AMPLIFICATION OCCURS ALONG THE PACIFIC COAST THROUGH THE REMAINDER OF THIS FORECAST PERIOD. DIFLUENT DOWNSTREAM REGIME MAY SPREAD TO THE IMMEDIATE LEE OF THE ROCKIES...BUT BROADLY CONFLUENT UPPER FLOW WILL PERSIST EAST OF THE HIGH PLAINS INTO BROAD WESTERN ATLANTIC TROUGH. WITHIN THIS PATTERN...A SIGNIFICANT IMPULSE IN BELT OF POLAR WESTERLIES IS PROGGED TO ACCELERATE SOUTHEAST OF THE MID MISSOURI VALLEY THROUGH MUCH OF THE LOWER OHIO VALLEY BY 12Z FRIDAY...AHEAD OF ANOTHER SHORT WAVE DIGGING SOUTH OF THE CENTRAL CANADIAN PROVINCES. A SHEARING IMPULSE IN THE SUBTROPICAL STREAM MAY ACCOMPANY LEAD SYSTEM...AND MODELS SUGGEST LARGE-SCALE FORCING WILL CONTRIBUTE TO EROSION/RETREAT OF SOUTH CENTRAL/SOUTHEAST STATES SURFACE RIDGE. THIS SHOULD ALLOW FOR A RETURN FLOW OFF THE GULF OF MEXICO...THROUGH SOUTHEAST TEXAS AND THE LOWER MISSISSIPPI VALLEY...AND IN A NARROW TONGUE TO THE VICINITY OF A WEAK SURFACE CYCLONE ACCOMPANYING POLAR TROUGH THROUGH THE LOWER OHIO VALLEY. ...SOUTH CENTRAL STATES... AHEAD OF NEXT COLD INTRUSION THROUGH THE PLAINS AND MISSISSIPPI VALLEY...MODELS SUGGEST AN ELEVATED MIXED LAYER WILL ADVECT EAST NORTHEAST OF THE MEXICAN PLATEAU THROUGH MUCH OF SOUTHERN/EASTERN TEXAS INTO WESTERN LOUISIANA. THIS WILL CONTRIBUTE TO STEEP LAPSE RATES ABOVE A DEEPENING MOIST BOUNDARY WITH SURFACE DEW POINTS CLIMBING IN EXCESS OF 60F. BY THURSDAY AFTERNOON...MIXED LAYER CAPE SEEMS LIKELY TO EXCEED 1000 J/KG...WITH INHIBITION WEAKENING IN RESPONSE TO MID-LEVEL COOLING IN WAKE OF SUBTROPICAL IMPULSE. MODELS SUGGEST THIS MAY BE ENOUGH FOR SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT. AIDED BY FAVORABLE DEEP LAYER SHEAR BENEATH MODERATELY STRONG MID/UPPER FLOW...ISOLATED SUPERCELLS ARE EXPECTED. RATHER LIGHT LOW-LEVEL FLOW AND SMALL LOW-LEVEL HODOGRAPHS SHOULD LIMIT TORNADO POTENTIAL...BUT LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE. THIS SHOULD CONTINUE INTO EARLY EVENING...BEFORE COLD SURFACE RIDGE NOSES INTO THE WESTERN GULF COAST. IN RESPONSE TO DEVELOPMENTS IN THE UPSTREAM UPPER FLOW...MODELS SUGGEST LOW-LEVEL WARM ADVECTION WILL INCREASE ABOVE FRONTAL INVERSION LATE THURSDAY NIGHT...FROM PARTS OF THE TEXAS HILL COUNTRY INTO THE TEXAS SOUTH PLAINS. ELEVATED MOISTURE RETURN AND STEEPENING MID-LEVEL LAPSE RATES MAY CONTRIBUTE TO ENOUGH CAPE FOR AT LEAST MARGINAL SEVERE HAIL POTENTIAL TOWARD 12Z FRIDAY. ...LOWER OHIO VALLEY... MODELS CONTINUE TO SUGGEST ENOUGH DESTABILIZATION WILL OCCUR WITH POLAR TROUGH BY THURSDAY AFTERNOON FOR RISK OF WEAK THUNDERSTORM ACTIVITY. THIS SEEMS MOST LIKELY NEAR/JUST SOUTHEAST OF SURFACE LOW...FROM PARTS OF SOUTHEASTERN INDIANA INTO SOUTHERN OHIO...NEAR OR SHORTLY AFTER PEAK DAYTIME HEATING. ...PACIFIC NORTHWEST... POTENTIAL FOR ISOLATED THUNDERSTORMS WILL EXIST THURSDAY AFTERNOON AND EVENING AS COLD MID-LEVEL CIRCULATION...WITHIN DEVELOPING LARGER SCALE TROUGH...PROGRESSES INTO WESTERN WASHINGTON. ..KERR.. 03/15/2006  From SWODY2 at goshenarc.org Wed Mar 15 17:27:30 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 15 Mar 2006 12:27:30 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060315173016.91231D4B0D@mail.goshen.edu> ACUS02 KWNS 151727 SWODY2 SPC AC 151726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST WED MAR 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN LA INTO SCNTRL TX... ...SOUTH CENTRAL U.S... WEAK UPPER RIDGING WILL BUILD INTO THE SRN PLAINS LATE IN THE DAY2 PERIOD AS STRONG SPEED MAX EJECTS ACROSS MO INTO NC. THIS FEATURE WILL BE PARTLY RESPONSIBLE FOR SWD PLUNGE OF CT AIR THROUGH THE MID SECTION OF THE COUNTRY FORCING SFC BOUNDARY DEEP INTO TX/LA BY PEAK HEATING. IN THE ABSENCE OF LARGE SCALE SUPPORT FOR DEEP ASCENT ALONG THIS ADVANCING COLD FRONT...IT APPEARS STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL IN POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE COASTAL PLAINS OF TX INTO SWRN PORTIONS OF LA BY LATE AFTERNOON. FORECAST SOUNDINGS SUGGEST BOUNDARY LAYER PARCELS WILL BECOME WEAKLY INHIBITED AFTER 21Z AS LOW LEVEL LAPSE RATES STEEPEN AND SFC TEMPERATURES WARM TO NEAR 80 DEG. IT APPEARS SCATTERED THUNDERSTORMS WILL DEVELOP ALONG ADVANCING COLD FRONT WHILE VEERING PROFILES WITH HEIGHT AND SUFFICIENT VERTICAL SHEAR ENHANCE THE THREAT FOR ROTATING STORMS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH MORE SUSTAINED UPDRAFTS. LATER IN THE OVERNIGHT PERIOD...STRENGTHENING LLJ ACROSS THE EDWARDS PLATEAU INTO WEST TX WILL AID ELEVATED CONVECTIVE THREAT FOR PARCELS LIFTED NEAR 800 MB. MARGINAL SEVERE HAIL MAY ACCOMPANY THIS ACTIVITY AS IT SPREADS/DEVELOPS NWD ACROSS THE TX SOUTH PLAINS. ...OH VALLEY... PLUME OF STEEP LAPSE RATES WILL SPREAD ACROSS THE OH VALLEY...NORTH OF STRONG SPEED MAX...AHEAD OF WELL DEFINED SHORTWAVE TROUGH THURSDAY. ISOLATED THUNDERSTORMS MAY EVOLVE WITHIN WARM ADVECTION ZONE JUST EAST OF ADVANCING SFC LOW...MAINLY DURING THE DAYTIME HOURS. ...PACIFIC NW... YET ANOTHER SFC FRONT WILL MOVE ONSHORE ALONG THE WA/ORE COAST EARLY IN THE PERIOD WITH ONSHORE FLOW AND MORE BUOYANT MARITIME AIRMASS BENEATH COLD UPPER TROUGH. ISOLATED LOW TOPPED THUNDERSTORMS MAY DEVELOP ACROSS THIS REGION THROUGH THE PERIOD...ESPECIALLY GIVEN THE SUSTAINED SECONDARY LOW LEVEL CONVERGENT TROUGH JUST OFF THE COAST. ..DARROW.. 03/15/2006  From SWODY2 at goshenarc.org Sat Mar 18 06:03:07 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 18 Mar 2006 01:03:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060318060608.4D8EED4653@mail.goshen.edu> ACUS02 KWNS 180603 SWODY2 SPC AC 180602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 AM CST SAT MAR 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL AND SRN HIGH PLAINS THROUGH TX AND THE LOWER MS VALLEY... ...SYNOPSIS... UPPER TROUGH NOW OVER CNTRL CA IS FORECAST TO CONTINUE EWD THROUGH THE SWRN U.S. AND INTO THE SRN PLAINS BY SUNDAY NIGHT. POTENTIAL WILL ALSO EXIST FOR MINOR IMPULSES EMBEDDED WITHIN THE SRN STREAM TO EJECT NEWD INTO TX SUNDAY AHEAD OF THE MAIN UPPER TROUGH. MODELS AGREE THAT A STRONG SPEED MAX WILL EJECT NEWD THROUGH WRN TX SUNDAY NIGHT ACCOMPANIED BY A PACIFIC FRONT. A SURFACE BOUNDARY CURRENTLY ACROSS S TX WILL PERSIST IN ADVANCE OF THIS FEATURE AND WILL LIFT SLOWLY NWD THROUGH THE DAY. BY SUNDAY AFTERNOON...THIS BOUNDARY SHOULD EXTEND FROM LA NWWD THROUGH CNTRL AND NWRN TX WHERE IT WILL INTERSECT WITH THE DRYLINE. ...SRN HIGH PLAINS THROUGH TX AND SRN PARTS OF THE LOWER MS VALLEY... GRADIENT BETWEEN SURFACE RIDGE OVER THE ERN HALF OF THE COUNTRY AND LEE TROUGH OVER THE CNTRL/SRN HIGH PLAINS WILL MAINTAIN A SLY LOW LEVEL COMPONENT THROUGH SUNDAY. GULF MOISTURE WITH DEWPOINTS IN THE MID TO UPPER 60S RESIDING S OF FRONT OVER S TX WILL ADVECT NWWD UNDERNEATH PLUME OF STEEPER LAPSE RATES CONTRIBUTING TO DESTABILIZATION SUNDAY AFTERNOON FROM PARTS OF WRN/CNTRL TX NWD INTO PARTS OF THE CNTRL HIGH PLAINS. THERE IS SOME CONCERN THAT POTENTIAL FOR EXTENSIVE HIGH CLOUDS COULD HAVE A DAMPENING EFFECT ON HEATING. ELY FLOW AT THE SURFACE AND LOW CLOUDS WILL PERSIST N OF THE SURFACE FRONT ACROSS NRN TX INTO OK. HOWEVER...SLY FLOW ABOVE THE SURFACE LAYER WILL LIKELY RESULT IN SOME ELEVATED INSTABILITY...ESPECIALLY FROM NWRN TX INTO WRN OK WHERE STEEPER LAPSE RATES WILL EXIST. ELEVATED STORMS MAY BE ONGOING FROM NRN TX INTO OK SUNDAY MORNING. THIS ACTIVITY SHOULD SHIFT EWD THROUGH THE LOWER MS VALLEY DURING THE DAY. AS THE WARM SECTOR DESTABILIZES AND CAP WEAKENS...OTHER STORMS MAY DEVELOP FARTHER W OVER THE HIGHER TERRAIN OF WRN TX/ERN NM AND IN VICINITY OF THE DRYLINE. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS WITH ANY SURFACE BASED ACTIVITY. STORMS ARE EXPECTED TO BECOME MORE NUMEROUS BY LATE AFTERNOON AND EVENING OVER THE SRN HIGH PLAINS AND WRN TX AS FORCING FOR ASCENT INCREASES WITHIN EXIT REGION OF EJECTING SPEED MAX. OTHER STORMS SHOULD DEVELOP AS THE PACIFIC FRONT OVERTAKES THE DRYLINE ACROSS WRN TX...AND THIS ACTIVITY WILL LIKELY EVOLVE INTO AN MCS AS IT SPREADS EWD THROUGH TX OVERNIGHT. THE SEVERE THREAT SHOULD INCREASE TOWARD THE LOWER MS VALLEY LATE IN THE PERIOD AS THE LOW LEVEL JET STRENGTHENS AND POTENTIAL FOR SURFACE BASED STORMS WITHIN THE WARM SECTOR INCREASES. ..DIAL.. 03/18/2006  From SWODY2 at goshenarc.org Sat Mar 18 17:30:50 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 18 Mar 2006 12:30:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060318173352.33274D4703@mail.goshen.edu> ACUS02 KWNS 181731 SWODY2 SPC AC 181730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST SAT MAR 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN PLAINS INTO THE LWR MS VLY... ...SYNOPSIS... THE UPPER TROUGH ACROSS THE WRN STATES WILL BEGIN TO MOVE EWD ON SUNDAY AS THE UPPER LOW ACROSS SERN CANADA ELONGATES E-W AND THE TROUGH OVER THE ALEUTIANS BEGINS TO DIG SEWD. WHILE LOW-AMPLITUDE IMPULSES WILL EJECT NEWD FROM THE BASE OF THE TROUGH DURING SUNDAY...THE PRIMARY TROUGH WILL WAIT UNTIL SUNDAY NIGHT OR EARLY MON TO BODILY TRANSLATE EWD ACROSS THE SRN PLAINS. AT THE SFC...PRIMARY FRONT SITUATED FROM THE NRN GULF BASIN WWD ACROSS CNTRL TX AND THE SRN HIGH PLAINS TODAY WILL REDEVELOP NWD INTO THE LWR MS VLY...NRN TX AND THE CNTRL HIGH PLAINS BY SUNDAY EVENING. LEE-LOWS WILL STRENGTHEN OVER NERN NM AND ACROSS SWRN TX EARLY SUNDAY...WITH A DRY LINE MIXING EWD INTO THE TX SPLAINS AND WCNTRL TX LATE SUNDAY AFTN. EVENTUALLY...A COLD FRONT WILL OVERTAKE THE DRY LINE AND MOVE EWD ACROSS WRN OK AND CNTRL TX BY 12Z MON. ...SRN PLAINS TO THE LWR MS VLY... SELY LOW-LEVEL FLOW WILL CONTINUE TO ADVECT MID-UPPER 60S DEW POINTS NWWD ACROSS CNTRL/SRN TX BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES TODAY AND SUNDAY. THIS WILL CONTRIBUTE TO DESTABILIZATION SUNDAY AFTN FROM PARTS OF WRN/CNTRL TX NWD INTO PARTS OF THE CNTRL PLAINS. POTENTIAL FOR ONGOING TSTM CLUSTERS AND CLOUDS WILL PROBABLY IMPEDE NWD MOVEMENT OF THE WARM FRONT. BUT...SLY FLOW ABOVE THE BOUNDARY LAYER WILL SUPPORT ELEVATED INSTABILITY AND A CONTINUED RISK OF LARGE HAIL...ESPECIALLY ACROSS N TX AND SWRN OK. ELEVATED CLUSTERS OF TSTMS WILL LIKELY BE ONGOING ACROSS OK/N TX AT 12Z SUNDAY ALONG NOSE OF A SLY LLJ. THIS ACTIVITY SHOULD SHIFT EWD THROUGH THE LWR MS VLY DURING THE DAY. MEANWHILE...THE WARM SECTOR SHOULD GROW SPATIALLY DURING SUNDAY AFTN ACROSS CNTRL/W TX. STRONGEST HEATING SHOULD TAKE PLACE FROM THE TX SPLAINS SWD INTO SWRN TX. WEAK HEIGHT FALLS...INFLOW OF MOIST BOUNDARY LAYER AND HEATING ALONG THE DRYLINE/HIGHER TERRAIN WILL LIKELY RESULT IN TSTM INITIATION DURING THE AFTN. SUPERCELL WIND PROFILES WILL EXIST ACROSS THESE AREAS AND LARGE HAIL /POSSIBLY GREATER THAN 2 INCHES IN DIAMETER/ WILL BE THE PRIMARY THREAT...THOUGH ISOLD TORNADOES MAY OCCUR. AS FORCING FOR ASCENT SPREADS EWD OVERNIGHT...TSTMS WILL LIKELY EVOLVE INTO ONE OR MORE MCS/S AND SPREAD/DEVELOP EWD ALONG THE WARM FRONT ACROSS NRN/CNTRL TX. ALONG WITH A HAIL THREAT...DAMAGING WINDS AND ISOLD TORNADOES WILL BE THREATS SUNDAY NIGHT AS FAR EAST AS THE LWR MS VLY AS THE LLJ QUICKLY DEVELOPS EWD. A SECONDARY AREA OF POSSIBLE SEVERE TSTMS WILL EXIST ALONG THE NRN EDGE OF THE MCS ACROSS THE TX PNHDL INTO WRN OK LATE SUNDAY NIGHT. THIS ACTIVITY WILL LARGELY BE ORIENTED WITHIN PARALLEL DEEP SLY FLOW DOWNSTREAM FROM THE PRIMARY THROUGH. THUS...STORMS MAY EVOLVE INTO A LEWPY STRUCTURE AND PRIMARY REMAIN ELEVATED WITH HAIL THE MAIN THREAT. ..RACY.. 03/18/2006  From SWODY2 at goshenarc.org Sun Mar 19 06:00:36 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 19 Mar 2006 01:00:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060319060333.DC90FD4703@mail.goshen.edu> ACUS02 KWNS 190601 SWODY2 SPC AC 190600 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1200 AM CST SUN MAR 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EXTREME ERN TX INTO PARTS OF THE LOWER MS VALLEY AND SERN U.S.... ...SYNOPSIS... THE UPPER TROUGH NOW OVER THE SWRN U.S. WILL CONTINUE EWD THROUGH MONDAY AND DE AMPLIFY BY LATE MONDAY AS IT MOVES INTO THE BLOCKING PATTERN OVER THE ERN THIRD OF THE COUNTRY. SEVERAL VORTICITY MAXIMA WILL ROTATE THROUGH THIS FEATURE. THE UPPER LOW WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL CONTINUE THROUGH ERN TX EARLY MONDAY AND INTO THE LOWER MS VALLEY BY AFTERNOON. INITIAL SURFACE LOW IS FORECAST TO OCCLUDE OVER ERN OK WITH SECONDARY LOW DEVELOPMENT EXPECTED FARTHER SE OVER THE LOWER MS VALLEY DURING THE DAY. THE LOW LEVEL JET WILL STRENGTHEN OVER THE LOWER MS VALLEY IN ADVANCE OF THE SHORTWAVE TROUGH...RESULTING IN NWD ADVANCE OF BOUNDARY NOW OVER THE NRN GULF. THE WARM SECTOR MAY SPREAD INLAND INTO MUCH OF LA...CNTRL MS AND AL MONDAY AFTERNOON. ...LOWER MS VALLEY THROUGH PARTS OF THE SERN STATES... STORMS WILL LIKELY BE ONGOING EARLY MONDAY WITHIN ZONE OF ISENTROPIC ASCENT N OF SURFACE FRONT ACROSS PARTS OF AR...CNTRL AND NRN MS INTO THE TN VALLEY. THIS MAY SERVE TO SLOW THE NWD RETREAT OF THE BOUNDARY DURING THE DAY. CURRENT THINKING IS THAT THE BOUNDARY MAY LIFT AS FAR N AS NRN LA...CNTRL MS AND AL BY MID TO LATE AFTERNOON. A STRONG SLY LOW LEVEL JET ASSOCIATED WITH THE CYCLONICALLY CURVED JET EXIT REGION WILL LIKELY EXIST OVER THE LOWER MS VALLEY EARLY MONDAY. THE LAST FEW RUNS OF THE GFS HAVE BEEN VEERING THIS FEATURE TO WSWLY MONDAY AFTERNOON WHICH...IF OCCURS...COULD SERVE AS A LIMITING FACTOR. HOWEVER...THE NAM MAINTAINS A MORE SLY COMPONENT. IN EITHER CASE...POTENTIAL WILL EXIST FOR CLOUDS AND PRE-FRONTAL CONVECTION TO DEVELOP EARLY WITHIN THE WARM SECTOR... AND THIS COULD LIMIT INSTABILITY. NEVERTHELESS...SOME DESTABILIZATION IS EXPECTED AS RICH LOW LEVEL MOISTURE ADVECTS INLAND AND WHERE POCKETS OF HEATING CAN DEVELOP. STORMS DEVELOPING WITHIN THE PRE-FRONTAL WARM SECTOR SHOULD INTENSIFY DURING THE DAY. STRONG VERTICAL SHEAR PROFILES WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS. MID LEVEL DRY SLOT WILL ADVANCE EWD DURING THE AFTERNOON RESULTING IN POTENTIAL FOR DESTABILIZATION FARTHER W IN VICINITY OF FRONT OVER THE LOWER MS VALLEY ONCE LOW CLOUDS MIX OUT. ANY STORMS THAT DEVELOP ALONG THE FRONT WILL ALSO HAVE THE POTENTIAL TO BECOME SEVERE. STRONGEST WARM SECTOR ACTIVITY IS EXPECTED TO CONTINUE EWD THROUGH PARTS OF MS AND AL DURING THE AFTERNOON AND EVENING. STORMS SHOULD BEGIN TO WEAKEN OVERNIGHT AS THE LOW LEVEL JET VEERS AND INSTABILITY BECOMES MORE MARGINAL TOWARD GA AND SC. ..DIAL.. 03/19/2006  From SWODY2 at goshenarc.org Sun Mar 19 17:34:03 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 19 Mar 2006 12:34:03 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060319173658.1003DD4A96@mail.goshen.edu> ACUS02 KWNS 191735 SWODY2 SPC AC 191734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CST SUN MAR 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN PLAINS INTO A LARGE PART OF THE DEEP S... ...SYNOPSIS... A TREND TOWARD A MORE PROGRESSIVE FLOW REGIME WILL CONTINUE EARLY THIS WEEK. SRN PARTS OF THE WRN STATES UPPER TROUGH WILL BEGIN TO SWING EWD TODAY AS THE NEXT IMPULSE DROPS TOWARD THE NRN CA COAST TONIGHT. THE FIRST TROUGH WILL BECOME NEGATIVELY TILTED EARLY MON...THEN CLOSE OFF INTO A LOW BEFORE ELONGATING E-W ACROSS THE MID-MS VLY ON TUE. PRIMARY SFC LOW WILL CONSOLIDATE OVER NW TX TONIGHT...THEN TRACK NEWD INTO THE TN VLY BY 12Z TUE. A WARM FRONT WILL REDEVELOP NWD THROUGH THE LWR MS VLY AND DEEP S WITH A COLD FRONT SWEEPING EWD ACROSS THE SRN PLAINS AND INTO THE LWR MS VLY LATE MON NIGHT. ...CNTRL-SERN TX ACROSS THE DEEP S... SEVERAL CLUSTERS OF TSTMS ARE EXPECTED TO BE ONGOING EARLY MON WITHIN A ZONE OF STRONG ISENTROPIC LIFT N OF THE WARM FRONT FROM THE SRN PLAINS INTO THE TN VLY. THOUGH THIS MAY IMPEDE NWD MOVEMENT OF THE FRONT...GIVEN TRACK OF THE 150 METER/12 HR H5 HEIGHT FALLS...WARM FRONT MAY REDEVELOP AS FAR N AS NRN LA...CNTRL MS AND WCNTRL-SRN AL BY MID-LATE MON AFTN. PRIND THAT THE STRONGEST MCS WILL BE ONGOING AT 12Z MON ACROSS PORTIONS OF CNTRL/ERN TX. DOWNSTREAM...BOUNDARY LAYER WILL CONTINUE TO MOISTEN AND DESTABILIZE THROUGH MON AFTN. UNCERTAINTY EXISTS ON HOW WIDESPREAD CLOUDS WILL BE IN THE WARM SECTOR...BUT CURRENT THINKING IS THAT AT LEAST LOCAL HEATING WILL RESULT IN POCKETS OF MODEST INSTABILITY. AS A RESULT...TSTMS WILL BECOME MORE WIDESPREAD ACROSS THE LWR MS VLY MON AFTN...THEN SPREAD ENEWD ACROSS THE DEEP S/TN VLY THROUGH MON NIGHT. STRONG VERTICAL SHEAR PROFILES WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...PARTICULARLY AS THE STORMS TRACK VCNTY THE WARM FRONT AND SUB-SYNOPTIC LOWS EARLY IN STORM LIFE CYCLES. ACTIVITY MAY TEND TO BECOME MORE LINEAR WITH TIME WITH LEWPS/BOWS. SEVERE PROBABILITIES WILL DECREASE WITH EWD EXTENT OVERNIGHT MON AS THE STORMS ENCOUNTER THE COLD WEDGE ACROSS NERN AL...NRN GA AND THE CAROLINAS. IF PRE-FRONTAL WARM SECTOR APPEARS TO BE MORE UNSTABLE IN FUTURE OUTLOOKS...AN UPGRADE TO MDT RISK IS POSSIBLE ACROSS THE LWR MS VLY INTO CNTRL/SRN MS. ...SRN PLAINS... A SECONDARY AREA OF SEVERE WEATHER POTENTIAL WILL DEVELOP DURING MON AFTN ALONG THE COLD FRONT FROM PARTS OF SRN OK INTO NERN TX. ANY CLEARING IN WAKE OF THE WARM CONVEYOR ACROSS THE LWR MS VLY WILL CONTRIBUTE TO DESTABILIZATION ALONG THE COLD FRONT GIVEN DECREASING TEMPERATURES ALOFT AND RESIDUAL BOUNDARY LAYER MSTR. VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED STORMS WITH HAIL AND POSSIBLE ISOLD TORNADOES. THIS ACTIVITY WILL MOVE ENEWD ACROSS AR AND INTO THE TN VLY OVERNIGHT. ..RACY.. 03/19/2006  From SWODY2 at goshenarc.org Mon Mar 20 05:55:10 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Mar 2006 00:55:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060320055821.64C2FD4A94@mail.goshen.edu> ACUS02 KWNS 200555 SWODY2 SPC AC 200555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 PM CST SUN MAR 19 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN GA INTO THE NRN HALF OF THE FL PENINSULA... ...SYNOPSIS... THE UPPER TROUGH CURRENTLY OVER THE SWRN STATES WILL CONTINUE EWD AND DEAMPLIFY OVER THE TN/OH VALLEY TUESDAY AS IT MOVES INTO THE BLOCK SITUATED OVER THE ERN THIRD OF THE COUNTRY. ATTENDANT SURFACE LOW WILL OCCLUDE OVER THE TN VALLEY...WHILE SECONDARY CYCLOGENESIS COMMENCES ALONG BAROCLINIC ZONE OFF THE CAROLINA COAST TUESDAY MORNING. COLD FRONT WILL CONTINUE SEWD INTO THE NRN FL PENINSULA BY LATE TUESDAY AFTERNOON AND EVENING. ...SRN GA THROUGH THE NRN HALF OF THE FL PENINSULA... THE LOW LEVEL JET WILL VEER TO WLY OVER THE SERN U.S. AND THE NERN GULF LATE MONDAY AND PERSIST INTO TUESDAY. THIS WILL CONTRIBUTE TO THE EWD ADVECTION OF RICHER GULF MOISTURE INTO THE PRE-FRONTAL WARM SECTOR ACROSS THE NRN FL PENINSULA. THE ATMOSPHERE IS EXPECTED TO BECOME MODERATELY UNSTABLE AS HEATING COMMENCES. STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH EWD ADVANCING MID LEVEL JET IS EXPECTED TO REMAIN WELL N OF THIS REGION...AND THIS COULD SERVE TO LIMIT STORM COVERAGE. HOWEVER...SEA BREEZE CIRCULATIONS AND RESIDUAL OUTFLOW BOUNDARIES FROM MORNING CONVECTION COULD SERVE TO INITIATE NEW STORMS WITHIN THE PRE-FRONTAL WARM SECTOR. STRONG MID LEVEL FLOW ON THE SRN PERIPHERY OF THE UPPER TROUGH WILL MAINTAIN UNIDIRECTIONAL SHEAR PROFILES FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND THE PRIMARY THREATS. THREAT SHOULD DIMINISH DURING THE EVENING WITH LOSS OF HEATING. ..DIAL.. 03/20/2006  From SWODY2 at goshenarc.org Mon Mar 20 17:02:02 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Mar 2006 12:02:02 -0500 Subject: [SWODY2] SWODY2 Message-ID: <20060320170452.56494D4700@mail.goshen.edu> ACUS02 KWNS 201703 SWODY2 SPC AC 201702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1102 AM CST MON MAR 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE ACROSS THE SOUTHEAST STATES...MAINLY PARTS OF NRN FL.... MODELS INDICATE THAT HIGH LATITUDE BLOCKING WILL PERSIST THROUGH THIS FORECAST PERIOD...WITH AN ASSOCIATED CLOSED LOW LINGERING OVER SOUTHEAST CANADA AND THE NORTHEASTERN STATES...WHILE ANOTHER CLOSED LOW EVOLVES OVER THE NORTHEAST PACIFIC. FARTHER SOUTH...A SOUTHERN BELT OF POLAR WESTERLIES...AND THE SUBTROPICAL WESTERLIES...WILL COMPRISE A BROAD STRONG...GENERALLY ZONAL FLOW ACROSS THE SOUTHERN TIER STATES. WITHIN THIS REGIME...A COUPLE OF EMBEDDED SHORT WAVES WILL REMAIN OR BECOME MORE PROGRESSIVE. THE LEAD IMPULSE...WHICH IS NOW ADVANCING INTO/ACROSS THE SOUTH CENTRAL PLAINS...IS FORECAST TO LIFT INTO THE MIDDLE MISSISSIPPI VALLEY BY 12Z TUESDAY...BEFORE TURNING SOUTHEASTWARD AND ACCELERATING THROUGH CONFLUENT FLOW INTO THE WESTERN ATLANTIC BY 12Z WEDNESDAY. AN UPSTREAM SHORT WAVE TROUGH WILL BE A BIT SLOWER...BUT IS STILL PROGGED TO MIGRATE FROM CENTRAL/SOUTHERN CALIFORNIA INTO THE FOUR CORNERS REGION BY THE END OF THE FORECAST PERIOD. ...SOUTHEAST STATES... WITH THE BROADER SCALE PATTERN REMAINING SUPPORTIVE OF HIGH SURFACE PRESSURE ACROSS MUCH OF EASTERN NORTH AMERICA...SURFACE CYCLOGENESIS ACCOMPANYING SOUTHERN STREAM IMPULSE IS EXPECTED TO REMAIN WEAK. AN INITIAL PRIMARY SURFACE LOW LIKELY WILL ALREADY BE WEAKENING OVER THE TENNESSEE VALLEY BY THE BEGINNING OF THE FORECAST PERIOD...WITH SECONDARY SURFACE WAVE DEVELOPMENT OCCURRING NEAR/OR SOUTHEAST OF THE SOUTH CAROLINA COAST. THIS SHOULD LIMIT EXTENT OF SEVERE THREAT FOR THIS FORECAST PERIOD. IN FACT...AS MODERATELY STRONG LOW-LEVEL WIND FIELDS BECOME WESTERLY RATHER EARLY IN THE DAY...CONVECTIVE POTENTIAL WILL DIMINISH ACROSS MUCH OF THE SOUTHEAST. AN EXCEPTION COULD BE MOIST PRE-FRONTAL ENVIRONMENT ACROSS PARTS OF NORTHERN FLORIDA AND THE FLORIDA PENINSULA...WHERE DEEP LAYER SHEAR WILL BE STRONG...AND SURFACE HEATING COULD CONTRIBUTE TO WEAK TO MODERATE BOUNDARY LAYER DESTABILIZATION. HOWEVER...LOW-LEVEL CONVERGENCE WILL BE WEAK/HIGHLY LOCALIZED...AND MID-LEVEL INHIBITION SUBSTANTIAL...WHICH WILL LIMIT COVERAGE OF STORMS. A RISK FOR A TORNADO WILL EXIST IN ANY STORMS WHICH DO DEVELOP...BUT DAMAGING WIND GUSTS WITH ISOLATED DOWNBURSTS SEEMS LIKELY TO BE PRIMARY SEVERE THREAT. ...EASTERN GREAT BASIN... AS A MID-LEVEL JET STREAK NOSES ACROSS THE SOUTHERN PLATEAU TUESDAY...COOLING/LIFT IN ITS EXIT REGION APPEARS LIKELY TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR CONVECTIVE DEVELOPMENT. MUCH OF THIS ACTIVITY IS EXPECTED TO BE DIURNAL...BUT OCCASIONAL THUNDERSTORMS COULD PERSIST THURSDAY NIGHT NEAR THE FOUR CORNERS...IN CLOSER PROXIMITY TO MID-LEVEL CIRCULATION. ..KERR.. 03/20/2006  From SWODY2 at goshenarc.org Tue Mar 21 17:17:16 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Mar 2006 12:17:16 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060321172002.674BFD4249@mail.goshen.edu> ACUS02 KWNS 211712 SWODY2 SPC AC 211710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST TUE MAR 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD. BUT...IT APPEARS THE LAST IN A SERIES OF SIGNIFICANT SHORT WAVE TROUGHS...ASSOCIATED WITH A BELT OF POLAR WESTERLIES ACROSS THE SOUTHERN TIER STATES...WILL GRADUALLY PROGRESS OUT OF THE SOUTHERN PLATEAU. PROGGED OVER THE FOUR CORNERS STATES AT 12Z WEDNESDAY...THIS FEATURE IS FORECAST TO CROSS THE SOUTHERN ROCKIES...THEN TURN SOUTHEASTWARD INTO THE RED RIVER VALLEY BY EARLY WEDNESDAY EVENING. EVENTUALLY THIS SYSTEM WILL BECOME SHEARED AND ACCELERATE MORE RAPIDLY EASTWARD AS IT CONTINUES INTO AN INCREASINGLY CONFLUENT UPPER FLOW REGIME. THIS COULD OCCUR AS EARLY AS LATE WEDNESDAY NIGHT...BUT APPEARS MORE LIKELY THURSDAY. IN THE WAKE OF A PRIOR IMPULSE...A COLD INTRUSION TO THE LEE OF THE ROCKIES WILL HAVE DRIED/STABILIZED MOST AREAS...INCLUDING THE NORTHERN AND CENTRAL GULF OF MEXICO...BY THE BEGINNING OF THE FORECAST PERIOD. THE UPPER FLOW REGIME WILL MAINTAIN STRONG SURFACE RIDGING THROUGH MUCH OF EASTERN NORTH AMERICA...AND THE POTENTIAL FOR EVEN A WEAK RETURN FLOW OF GULF MOISTURE ABOVE THIS STABLE LAYER LOOKS TO BE MINIMAL. THIS WILL PRECLUDE ANY RISK FOR VIGOROUS THUNDERSTORM ACTIVITY. ...SOUTH CENTRAL STATES... MODELS DO SUGGEST A ZONE OF LOWER/MID TROPOSPHERIC WARM ADVECTION AND MOISTENING ASSOCIATED WITH THE SUBTROPICAL STREAM WILL OVERSPREAD PARTS OF SOUTHEAST TEXAS INTO CENTRAL GULF COASTAL AREAS BY WEDNESDAY AFTERNOON. THIS WILL OCCUR IN ADVANCE OF SOUTHERN BRANCH TROUGH SHIFTING TO THE LEE OF THE SOUTHERN ROCKIES...BUT DOWNSTREAM HEIGHT FALLS ASSOCIATED WITH THIS FEATURE MAY CONTRIBUTE TO WEAKENING MID/UPPER LEVEL INHIBITION AND CONVECTIVE DEVELOPMENT. MODEL FORECAST SOUNDINGS SUGGEST ENOUGH CAPE COULD DEVELOP IN MOIST LAYER BASED AROUND 700 MB...THROUGH FAVORABLE MIXED PHASE LAYER... FOR WEAK THUNDERSTORM ACTIVITY. ..KERR.. 03/21/2006  From SWODY2 at goshenarc.org Wed Mar 22 17:07:21 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Mar 2006 12:07:21 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060322171003.C4A26D473F@mail.goshen.edu> ACUS02 KWNS 221707 SWODY2 SPC AC 221706 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1106 AM CST WED MAR 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD AND BEYOND. BUT...A STRONG BELT OF POLAR WESTERLIES...WHICH HAS TRAVERSED THE SOUTHERN TIER OF THE U.S...IS PROGGED TO FINALLY BEGIN SHIFTING EAST OF THE SOUTHEAST STATES. THE LAST IN A SERIES OF SIGNIFICANT SHORT WAVE IMPULSES ASSOCIATED WITH THIS FEATURE IS FORECAST TO ACCELERATE INTO CONFLUENT REGIME ACROSS THE CENTRAL/EASTERN GULF STATES... BECOMING INCREASINGLY SHEARED AS IT APPROACHES SOUTH ATLANTIC COASTAL AREAS BY 12Z FRIDAY. FORCING ASSOCIATED WITH UPPER IMPULSE IS EXPECTED TO SUPPORT WEAK WAVE DEVELOPMENT ALONG SURFACE FRONT NOW STALLING NEAR SOUTHERN FLORIDA COASTAL AREAS AND THE KEYS. IN ITS WAKE...LARGE COLD SURFACE RIDGE...ENCOMPASSING MUCH OF EASTERN NORTH AMERICA...IS PROGGED TO NOSE THROUGH THE REMAINDER OF THE GULF OF MEXICO/THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE. THIS WILL SIGNIFICANTLY MINIMIZE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION THROUGH THURSDAY/THURSDAY NIGHT...AND THE DAYS TO FOLLOW. ...FLORIDA... MID-LEVEL HEIGHT FALLS AND FORCING ASSOCIATED WITH DEVELOPING SURFACE WAVE SHOULD BECOME SUPPORTIVE OF THUNDERSTORM ACTIVITY THURSDAY. MUCH OF THIS LIKELY WILL OCCUR OFFSHORE...BUT MODELS SUGGEST SOME POTENTIAL FOR INLAND DEVELOPMENT...WITH PROBABILITIES INCREASING TOWARD SOUTHEAST COASTAL AREAS. ...PACIFIC NORTHWEST... LARGE...COLD MID-LEVEL LOW OVER THE NORTHEAST PACIFIC IS EXPECTED TO MOVE LITTLE THROUGH EARLY FRIDAY. THUS...POTENTIAL FOR DEEP CONVECTIVE DEVELOPMENT INLAND OF COASTAL AREAS DURING THIS PERIOD APPEARS MINIMAL. HOWEVER...IMPULSES ROTATING AROUND THE CIRCULATION CENTER MAY MAINTAIN A RISK OF SCATTERED THUNDERSTORM ACTIVITY NEAR OFFSHORE WATERS. ..KERR.. 03/22/2006  From SWODY2 at goshenarc.org Thu Mar 23 17:12:35 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Mar 2006 12:12:35 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060323171514.945B4D4989@mail.goshen.edu> ACUS02 KWNS 231712 SWODY2 SPC AC 231711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CST THU MAR 23 2006 VALID 241200Z - 251200Z ...NO SVR TSTM AREAS FORECAST... THE BULK OF A STRONGER BELT OF WESTERLIES HAS SHIFTED OUT ACROSS THE ATLANTIC...AND THE LAST IN A SERIES OF ASSOCIATED SHORT WAVE TROUGHS ASSOCIATED WITH THIS FEATURE IS FORECAST TO PROGRESS EAST OF THE SOUTH ATLANTIC COAST BY MID DAY FRIDAY. IN ITS WAKE... MODELS INDICATE THAT THE HIGHER LATITUDE BLOCKING PATTERN WILL PERSIST... WITH AN UPPER HIGH REMAINING CENTERED OVER THE NORTH CENTRAL CANADIAN PROVINCES...WHILE CLOSED LOWS LINGER OVER THE NORTHEAST PACIFIC AND OHIO VALLEY. UPPER FLOW REGIME WILL CONTINUE TO SUPPORT A LARGE COLD SURFACE RIDGE ACROSS MUCH OF EASTERN NORTH AMERICA THROUGH THE WESTERN GULF OF MEXICO/BAY OF CAMPECHE AND YUCATAN PENINSULA. SOUTHERN PORTION OF THIS RIDGE MAY BEGIN TO WEAKEN IN RESPONSE TO SHORT WAVE TROUGH PROGRESSING THROUGH RELATIVELY WEAK BELT OF SUBTROPICAL WESTERLIES ACROSS THE MEXICAN PLATEAU. HOWEVER... EFFECTS OF SURFACE RIDGE WILL MINIMIZE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION EAST OF THE ROCKIES THROUGH THIS PERIOD AND BEYOND. MODELS DO SUGGEST A MORE PROGRESSIVE UPPER FLOW MAY BEGIN TO DEVELOP FRIDAY ACROSS THE NORTH CENTRAL/NORTHEAST PACIFIC INTO THE NORTHERN PACIFIC COAST STATES. IN RESPONSE TO AN UPSTREAM IMPULSE DIGGING TO THE SOUTH/EAST OF THE ALEUTIANS...A VIGOROUS SHORT WAVE TROUGH...CURRENTLY EMBEDDED WITHIN BROADER CIRCULATION OVER THE NORTHEAST PACIFIC...IS PROGGED TO APPROACH THE NORTH CENTRAL PACIFIC COAST. THIS PROBABLY WILL NOT OCCUR UNTIL LATE FRIDAY NIGHT/EARLY SATURDAY...BUT MODELS SUGGEST TROUGH WILL BE PRECEDED INLAND...ACROSS WASHINGTON/OREGON...BY A WEAKER IMPULSE. ...PACIFIC NORTHWEST COAST STATES... MID-LEVEL COOLING ASSOCIATED WITH THE LEAD IMPULSE IS EXPECTED TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR SCATTERED AFTERNOON THUNDERSTORMS...MAINLY ACROSS COASTAL AND INTERIOR SECTIONS OF WASHINGTON/OREGON. WEAK INSTABILITY WILL LIMIT STRENGTH OF UPDRAFTS...BUT THERMODYNAMIC ENVIRONMENT COULD BE SUFFICIENT FOR SOME SMALL HAIL OR GRAUPEL REACHING THE SURFACE IN STRONGER CELLS. MOST STORMS LIKELY WILL DIMINISH AFTER DARK FRIDAY EVENING...BUT A FEW STORMS MAY APPROACH SOUTHERN OREGON/NORTHERN CALIFORNIA COASTAL AREAS WITH STRONGER FORCING LATE FRIDAY NIGHT/EARLY SATURDAY. ..KERR.. 03/23/2006  From SWODY2 at goshenarc.org Fri Mar 24 05:52:54 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Mar 2006 00:52:54 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060324055528.8F199D4478@mail.goshen.edu> ACUS02 KWNS 240553 SWODY2 SPC AC 240552 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1152 PM CST THU MAR 23 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SYNOPTIC PATTERN WILL FEATURE TROUGHING OVER ERN AND WRN CONUS...WITH MEAN RIDGE FROM SRN ROCKIES NWD ACROSS CANADIAN PRAIRIES. UPPER LOW NOW OVER ERN GREAT LAKES REGION IS EXPECTED TO PIVOT SEWD THEN EWD OFFSHORE CAROLINAS/MID-ATLANTIC REGION LATE IN PERIOD. MEANWHILE...SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AROUND 45N148W -- IS FCST TO MOVE THROUGH BASE OF NERN PACIFIC UPPER LOW...AMPLIFY CONSIDERABLY...THEN MOVE ASHORE CA COAST AROUND 25/18Z. ALTHOUGH MINOR DISCREPANCIES EXIST WITH TIMING/AMPLITUDE OF PACIFIC TROUGH...GENERAL SCENARIO IS STRONGLY AGREED UPON BY LATEST OPERATIONAL MODELS AND SREFX MEMBERS. THIS TROUGH THEN SHOULD MOVE EWD ACROSS SIERRA NV RANGE AND WRN GREAT BASIN...REACHING LONGITUDE OF UT AND WRN MT BY END OF PERIOD. ASSOCIATED LOW LEVEL FRONTAL ZONE IS EXPECTED TO MOVE EWD ACROSS GREAT BASIN THROUGH PERIOD...PROVIDING PRIMARY FOCUS FOR STRONG-SEVERE TSTM POTENTIAL. ...GREAT BASIN... SCATTERED TSTMS ARE POSSIBLE ALONG BAROCLINICALLY FORCED BAND...AMIDST STRONG SFC-700 MB FRONTOGENETIC FORCING. ACTIVITY SHOULD SHIFT EWD TO NEWD ACROSS REGION...WITH GREATEST INTENSITY/COVERAGE EXPECTED DURING MID AFTERNOON TO EARLY EVENING. SOME TSTMS MAY BECOME ORGANIZED ENOUGH TO PRODUCE DAMAGING WIND. AFTERNOON HEATING...AT LEAST MRGL BOUNDARY LAYER MOISTURE...AND FAVORABLY STEEPENING MIDLEVEL LAPSE RATES...SHOULD DESTABILIZE AIR MASS OVER ERN NV AND WRN UT...PERHAPS INTO PORTIONS SRN ID. CLOUD COVER MAY LIMIT HEATING IN SOME AREAS...HOWEVER WEAK CINH...FRONTAL FORCING AND LARGE SCALE DESTABILIZATION SHOULD SUPPORT CONVECTIVE POTENTIAL. MEANWHILE...STRENGTHENING DEEP-LAYER VERTICAL SHEAR IS EXPECTED AS MIDLEVEL TROUGH APCHS...TIGHTENING HEIGHT/PRESSURE GRADIENTS THROUGH MUCH OF TROPOSPHERE. ACTIVITY SHOULD DIMINISH AFTER DARK AS SFC HEATING AND RELATED BUOYANCY DIMINISH...AND MAIN BAND OF FORCING MOVES INTO HIGHER TERRAIN OF NRN UT/SERN ID. ..EDWARDS.. 03/24/2006  From SWODY2 at goshenarc.org Fri Mar 24 17:26:43 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Mar 2006 12:26:43 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060324173129.C3549D4A83@mail.goshen.edu> ACUS02 KWNS 241727 SWODY2 SPC AC 241726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CST FRI MAR 24 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... BLOCKING IN THE LARGE-SCALE UPPER FLOW PATTERN ACROSS MUCH OF NORTH AMERICA PERSISTS. BUT...MODELS SEEM TO SUGGEST THAT AS A STRONG UPPER JET NOSES INTO THE WESTERN PACIFIC...REGIME MAY BECOME AT LEAST A BIT MORE PROGRESSIVE IN SPLIT BELTS OF STRONGER FLOW ACROSS THE CENTRAL/EASTERN PACIFIC. THIS INCLUDES A SIGNIFICANT SHORT WAVE TROUGH WHICH IS PROGGED TO DIG WELL SOUTH OF THE ALEUTIANS LATER TODAY THROUGH SATURDAY...FORCING ANOTHER VIGOROUS SHORT WAVE INLAND ACROSS THE NORTH CENTRAL PACIFIC COAST. THE LEAD IMPULSE IS CURRENTLY EMBEDDED WITHIN...AND ROTATING AROUND...THE SOUTHERN PERIPHERY OF A BROADER SCALE NORTHEAST PACIFIC CIRCULATION. THIS FEATURE IS FORECAST TO BECOME DETACHED FROM THE CIRCULATION BY 12Z SATURDAY...BEFORE ACCELERATING INLAND ACROSS OREGON/NORTHERN CALIFORNIA...AND THROUGH THE GREAT BASIN...BY 12Z SUNDAY. FARTHER DOWNSTREAM...UPPER FLOW WILL REMAIN CONFLUENT EAST OF THE ROCKIES INTO BROADER SCALE TROUGHING TO THE SOUTH OF OHIO VALLEY CLOSED LOW. THIS WILL MAINTAIN SURFACE RIDGING OVER MUCH OF EASTERN NORTH AMERICA THROUGH THE GULF OF MEXICO/BAY OF CAMPECHE/ AND THE CARIBBEAN. ...WESTERN STATES... MID-LEVEL COOLING AND FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED WITH SHORT WAVE TROUGH WILL CONTRIBUTE TO WEAK DESTABILIZATION AND CONVECTIVE DEVELOPMENT SATURDAY. THIS WILL INCLUDE THE POTENTIAL FOR SCATTERED THUNDERSTORMS OVER A FAIRLY BROAD AREA WEST OF THE ROCKIES. COLD CORE OF SYSTEM /500 MB TEMPS AS LOW AS -30C/ IS PROGGED TO OVERSPREAD THE SOUTHERN CASCADES/NORTHERN SIERRA AND SACRAMENTO VALLEY DURING THE PEAK AFTERNOON HEATING. THIS COULD CONTRIBUTE TO MIXED LAYER CAPE UP TO 500 J/KG...MAINLY IN THE LOWER/MORE MOIST SACRAMENTO VALLEY...WHERE OROGRAPHY MAY CONTRIBUTE TO SOUTHEASTERLY LOW-LEVEL FLOW IN WAKE OF SURFACE COLD FRONT. BENEATH STRONG CYCLONIC MID-LEVEL FLOW...THIS WILL PROVIDE FAVORABLE SHEAR FOR THE POSSIBILITY OF A LOW TOPPED SUPERCELL OR TWO...ALONG WITH ASSOCIATED RISK OF A TORNADO OR PERHAPS SOME MARGINALLY SEVERE HAIL. UNCERTAINTY EXISTS CONCERNING EXTENT OF CLOUD COVER ACROSS THE GREAT BASIN SATURDAY...WHICH COULD LIMIT MAGNITUDE OF SURFACE HEATING AND DESTABILIZATION. HOWEVER...FORCING/SHEAR SEEM LIKELY TO INCREASE ALONG SURFACE COLD FRONT FROM PARTS OF SOUTHERN IDAHO THROUGH CENTRAL NEVADA BY LATE AFTERNOON. THIS MAY BECOME SUPPORTIVE OF A DEVELOPING CONVECTIVE LINE ACCOMPANIED BY STRONG GUSTY WINDS...EVEN IN ABSENCE OF MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. ACTIVITY WILL SPREAD INTO PARTS OF THE EASTERN GREAT BASIN BEFORE DIMINISHING SATURDAY EVENING. ..KERR.. 03/24/2006  From SWODY2 at goshenarc.org Sat Mar 25 05:43:01 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Mar 2006 00:43:01 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060325054531.2B559D45E0@mail.goshen.edu> ACUS02 KWNS 250543 SWODY2 SPC AC 250541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST FRI MAR 24 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE SHORTWAVE PATTERN ACROSS CONUS WILL FEATURE STRONG TROUGH NOW EXHIBITING UPPER LEVEL CIRCULATION CENTER INVOF 41N134W...BASED ON MOISTURE CHANNEL IMAGERY. PERTURBATION IS FCST TO MOVE ACROSS COASTAL CA/ORE AND GREAT BASIN DAY-1...THEN FROM CENTRAL/NRN ROCKIES EWD ACROSS CENTRAL/NRN PLAINS THROUGH THIS PERIOD. MOST OPERATIONAL MODELS AND SREFX MEMBERS FCST CLOSED MIDLEVEL LOW BETWEEN JMS-OFK BY 27/12Z...ABOUT 100 NM W OF RELATED SFC CYCLONE. SFC COLD FRONT WILL REFORM WITHIN LEE TROUGHING AREA JUST E OF ROCKIES EARLY IN PERIOD...THEN MOVE SEWD ACROSS CENTRAL PLAINS AND SRN HIGH PLAINS BY 27/12Z. LARGE SCALE FORCING...IN FORM OF STRONG DPVA OVER NRN ROCKIES AND STRONG WAA OVER E-CENTRAL PLAINS AND LOWER MO VALLEY REGION...WILL CONTRIBUTE TO TWO MARGINAL GEN THUNDER OUTLOOKS. ...N-CENTRAL ROCKIES... ALTHOUGH LIMITED LOW-MIDDLE LEVEL MOISTURE WILL RESTRICT BUOYANCY...PRIND STEEP MIDLEVEL LAPSE RATES AND STRONG FRONTOGENETIC FORCING/LIFT WILL CONTRIBUTE TO OCCASIONAL SHORT-LIVED TSTMS. ACTIVITY SHOULD BE BASED WELL ABOVE SFC IN REGIME OF STRONGEST THERMAL COOLING ALOFT...WITH MUCAPES GENERALLY AOB 200 J/KG. ...E-CENTRAL PLAINS...OZARKS TO SRN IA... ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE AFTER ABOUT 27/06Z AMIDST STRONG LOW LEVEL WAA REGIME...COMBINED WITH MARGINAL MOISTURE EMANATING FROM RETURN FLOW TRAJECTORIES THAT HAVE BEEN ONLY WEAKLY MODIFIED FROM THEIR CONTINENTAL/POLAR ORIGINS. FCST SOUNDINGS FROM OPERATIONAL ETA...ETA-KF...AND NAM A.K.A. WRF...EACH INDICATE SUFFICIENT UVV/MOISTENING TO SATURATE PORTIONS 700-850 MB LAYER ABOVE STRONGEST CINH. PRIND PARCELS WILL BE ISENTROPICALLY LIFTED TO LFC W OF 45-55 KT SWLY LLJ THAT SHOULD EXTEND FROM N-CENTRAL TX TO E-CENTRAL MO BY 12Z. SEVERE POTENTIAL WILL BE GREATLY INHIBITED BY LACK OF MORE ROBUST MOISTURE...WITH ELEVATED MUCAPES LIKELY TO REMAIN UNDER 300 J/KG IN MOST AREAS. ..EDWARDS.. 03/25/2006  From SWODY2 at goshenarc.org Sat Mar 25 16:53:58 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Mar 2006 11:53:58 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060325165631.85269D46F5@mail.goshen.edu> ACUS02 KWNS 251654 SWODY2 SPC AC 251653 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1053 AM CST SAT MAR 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT-WAVE UPPER TROUGH MOVING ACROSS THE CENTRAL/NRN ROCKIES AT THE START OF THE PERIOD SHOULD REACH THE CENTRAL/NRN HIGH PLAINS BY LATE AFTERNOON...AND THEN CONTINUE EWD INTO THE MIDDLE MO VALLEY REGION BY THE END OF THE PERIOD. AHEAD OF THIS FEATURE...SURFACE LEE TROUGH WILL MOVE EWD INTO/ACROSS THE PLAINS THROUGH 27/12Z. ...ERN HALF OF WY AND VICINITY... COOL AIR ALOFT /-26 TO -28 C AT H5/ ASSOCIATED WITH UPPER TROUGH COMBINED WITH DAYTIME HEATING OVER THE HIGHER TERRAIN MAY YIELD MINIMAL INSTABILITY BY AFTERNOON. A FEW WEAK/HIGH-BASED STORMS ARE EXPECTED -- MAINLY OVER THE ERN HALF OF WY...BEFORE TROUGH SHIFTS EWD INTO THE PLAINS. ...KS/NRN OK EWD INTO WRN MO... LOW-LEVEL THETA-E ADVECTION AHEAD OF APPROACHING UPPER SYSTEM MAY RESULT IN SUFFICIENT MOISTENING TO ALLOW MINIMAL ELEVATED INSTABILITY TO DEVELOP BY EVENING. THUS...A LIMITED POTENTIAL FOR SCATTERED TO ISOLATED/WEAK THUNDERSTORM DEVELOPMENT APPEARS TO EXIST ACROSS PARTS OF KS/WRN MO AND VICINITY...MAINLY AFTER 27/00Z. ..GOSS.. 03/25/2006  From SWODY2 at goshenarc.org Sun Mar 26 05:41:52 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Mar 2006 00:41:52 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060326054416.E64F4D4989@mail.goshen.edu> ACUS02 KWNS 260542 SWODY2 SPC AC 260541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SAT MAR 25 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE MIDDLE-UPPER LEVEL PATTERN FCST THROUGH DAY-2...FEATURING STRONG SHORTWAVE TROUGH NOW MOVING EWD ACROSS NV...SERN ORE...AND SWRN ID. THIS FEATURE IS FCST TO MOVE EWD FROM NRN PLAINS ACROSS UPPER MS VALLEY AND OVER WI BY 28/12Z. ASSOCIATED SFC CYCLONE SHOULD BE NEARLY COLLOCATED BY 28/00Z-28/12Z TIME FRAME. SFC COLD FRONT WILL MOVE EWD ACROSS MO...SEWD ACROSS OK AND PORTIONS AR...AND SWD ACROSS RED RIVER REGION TOWARD PORTIONS N-CENTRAL/W-CENTRAL TX. ...CENTRAL/S TX... SCATTERED TO WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP DURING AFTERNOON/EVENING INVOF SFC COLD FRONT...AND PERHAPS ALONG DEVELOPING SW TX DRYLINE AND/OR HIGHER TERRAIN OF COAHUILA. ADDITIONAL CONVECTION IS POSSIBLE ALONG AND N OF SFC FRONT AFTER DARK...AMIDST STRENGTHENING LLJ AND WAA REGIME. CONTINENTAL/POLAR TRAJECTORIES NOW CROSSING PORTIONS NRN/CENTRAL GULF ARE EXPECTED TO RETURN NWWD ACROSS REGION IN INCOMPLETELY MODIFIED FORM...WITH MAINLY 50S F SFC DEW POINTS AND A FEW LOW 60S POSSIBLE OVER S TX. DIURNAL HEATING MAY BE LIMITED BY DENSE STRATOCUMULUS COVER WITHIN RETURN FLOW REGIME FOR MUCH OF THE DAY...THOUGH AFTERNOON BREAKS INVOF FRONTAL ZONE MAY HELP TO BOOST MLCAPES TO NEAR 1000 J/KG. WEAK LOW LEVEL FLOW DURING DAY WILL LIMIT HODOGRAPH SIZE...THOUGH STRONG DIRECTIONAL VEERING AND 30-40 KT DEEP-LAYER SHEAR INDICATE POTENTIAL FOR SOME ACTIVITY TO BECOME ORGANIZED WITH HAIL AND GUSTS NEAR SEVERE LEVELS. AFTER DARK...ACTIVITY ALONG AND N OF FRONT SHOULD BECOME SCATTERED-NUMEROUS IN COVERAGE...IN ONE OR MORE CLUSTERS OVER CENTRAL/NRN TX. WHILE THIS CONVECTION MAY PRODUCE HAIL...MAIN THREAT MAY BE HEAVY RAINFALL PER LATEST HPC QPF DISCUSSION. ALTHOUGH SEVERAL ENSEMBLE MEMBERS AND OPERATIONAL MODELS DEVELOP CONVECTION ACROSS PORTIONS S-CENTRAL TX BEFORE 28/00Z...PRIND THIS AIR MASS WILL REMAIN CAPPED DIURNALLY BY STRONG ELEVATED MIXED LAYER GENERATED DURING PRECEDING DAYS OF WLY/SWLY FLOW ALOFT. ISOLATED TSTMS MAY MOVE EWD ACROSS RIO GRANDE FROM OROGRAPHICALLY FORCED ASCENT ZONE IN SERRANIAS DEL BURRO RANGE. ..EDWARDS.. 03/26/2006  From SWODY2 at goshenarc.org Sun Mar 26 17:38:23 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Mar 2006 12:38:23 -0500 Subject: [SWODY2] {Spam?} SWODY2 Message-ID: <20060326174046.38415D46DE@mail.goshen.edu> ACUS02 KWNS 261739 SWODY2 SPC AC 261737 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CST SUN MAR 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW/SHORT-WAVE TROUGH INITIALLY OVER THE CENTRAL PLAINS IS FORECAST TO CONTINUE EWD ACROSS THE MIDWEST/OH VALLEY THROUGH THE END OF THE PERIOD. ASSOCIATED SURFACE LOW WILL ALSO MOVE EWD ACROSS THIS REGION...ACCOMPANIED BY WEAKENING COLD FRONT. FARTHER S/SW...A WEAK SRN-STREAM TROUGH IS FORECAST TO MOVE ACROSS NWRN MEXICO TOWARD TX DURING THE AFTERNOON. ...PARTS OF THE TRANSPECOS REGION/RIO GRANDE VALLEY/CENTRAL TX... MARGINAL DESTABILIZATION IS FORECAST ACROSS PARTS OF TX AHEAD OF SRN STREAM TROUGH...AS DAYTIME HEATING COMBINES WITH PARTIALLY-MODIFIED GULF MOISTURE RETURN TO YIELD 500 TO 1000 J/KG MEAN-LAYER CAPE. THOUGH CAP SHOULD HINDER CONVECTION ACROSS DEEP S TX...SCATTERED TO ISOLATED STORMS MAY DEVELOP ACROSS PARTS OF THE TRANSPECOS REGION AND INTO CENTRAL TX/THE HILL COUNTRY IN WEAK AXIS OF SURFACE CONVERGENCE ALONG FRONTOLYTIC BOUNDARY. THOUGH ONLY A SMALL/FAIRLY WEAK MID-LEVEL JET /30 TO 35 KT/ WILL ACCOMPANY THE SRN-STREAM FEATURE...AMPLE DIRECTIONAL SHEAR COULD SUPPORT A FEW STRONGER UPDRAFTS WITH MID-LEVEL ROTATION. THEREFORE...A LIMITED HAIL/WIND THREAT MAY EXIST -- PARTICULARLY THROUGH THE AFTERNOON. OVERNIGHT...LOW-LEVEL WARM ADVECTION N OF WEAKENING BOUNDARY MAY SUPPORT AN INCREASE IN STORM COVERAGE...THOUGH LIMITED INSTABILITY SHOULD PRECLUDE ANY MORE THAN A VERY MARGINAL HAIL THREAT. ..GOSS.. 03/26/2006  From SWODY2 at goshenarc.org Fri Mar 31 06:24:51 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 31 Mar 2006 01:24:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 310625 SWODY2 SPC AC 310624 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 AM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHWEST TEXAS....WESTERN OKLAHOMA...AND SOUTHERN KANSAS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM TX TO SERN NEB...SWRN IA...AND WRN PARTS OF MO AND AR... ...POTENTIAL EXISTS FOR NUMEROUS SEVERE STORMS WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES ACROSS PORTIONS OF THE SOUTHERN PLAINS ON SATURDAY... ...SYNOPSIS... ACTIVE FLOW REGIME CONTINUES INTO THE WEEKEND AS ANOTHER ROUND OF STRONG HEIGHT FALLS CROSS THE ROCKIES AND EMERGE OVER THE HIGH PLAINS ON SATURDAY...AHEAD OF PROGRESSIVE TROUGH CURRENTLY MOVING ONTO THE WEST COAST. DOWNSTREAM FROM THIS NEXT TROUGH...A VIGOROUS MID/UPPER LEVEL IMPULSE...NOW MOVING TOWARD THE UPPER MS VALLEY... WILL MOVE FROM THE ERN GREAT LAKES TOWARD THE CANADIAN MARITIME PROVINCES THROUGH THE DAY 2 PERIOD. SURFACE COLD FRONT ASSOCIATED WITH THE ERN SYSTEM SHOULD MOVE QUICKLY EAST ACROSS THE MID-ATLANTIC AND NEW ENGLAND REGIONS THROUGH SATURDAY AFTERNOON. THE TRAILING PORTION OF THE FRONTAL ZONE WILL EXTEND WWD FROM THE TN VALLEY TO THE ARKLATEX EARLY IN THE DAY 2 PERIOD. AS NEXT TROUGH APPROACHES THE PLAINS AND DEEP LAYER SLY FLOW INCREASES OVER THE REGION...EXPECT WARM FRONT TO LIFT NWD ACROSS OK/KS DURING THE DAY AS LEE-SIDE SURFACE CYCLOGENESIS COMMENCES OVER SRN CO. AS THIS OCCURS...DRYLINE SHOULD DEVELOP EAST FROM WRN PORTIONS KS/OK/TX INTO RICH BOUNDARY LAYER MOISTURE SPREADING NWD ACROSS THE PLAINS. LATEST GUIDANCE INDICATES THAT SURFACE LOW TRACKS ENEWD ALONG WARM FRONT OVER NRN KS THROUGH LATE SATURDAY NIGHT/SUNDAY MORNING AS STRONG DRYLINE DEVELOPS EAST INTO MOIST AND UNSTABLE WARM SECTOR FROM NWRN TX TO CNTRL OK/KS. ...SRN/CNTRL PLAINS... FORECAST SCENARIO APPEARS TO HAVE CHANGED LITTLE FROM EARLIER DAY 3 OUTLOOK...A CLASSIC SPRINGTIME WARM FRONT/DRYLINE SCENARIO IS INDICATED OVER THE PLAINS ON SATURDAY AFTERNOON. MODELS CONTINUE TO SUGGEST THE POTENTIAL FOR ISOLATED CONVECTION EARLY IN THE DAY ALONG DEVELOPING WARM FRONT ACROSS THE RED RIVER VALLEY...PERHAPS SUPPORTED BY WEAK LLJ DIRECTED INTO THE FRONTAL ZONE. AS WARM SECTOR EXPANDS NWD ACROSS THE REGION DURING THE DAY IT APPEARS THAT LOW TO MID 60S F DEWPOINTS AND RELATIVELY COOL TEMPERATURES ALOFT WILL CONTRIBUTE TO MLCAPE VALUES APPROACHING 2000 J/KG IN AN AXIS FROM NWRN TX ACROSS WRN OK AND INTO PARTS OF SWRN/SCNTRL KS BY AFTERNOON. WEAK TO MODEST CAPPING IS INDICATED IN BOTH NAMKF AND NAM-WRF SOUNDINGS ACROSS THIS INSTABILITY AXIS THROUGH THE AFTERNOON BUT ALL RECENT GUIDANCE INDICATES VIGOROUS CONVECTIVE INITIATION NEAR THE DRYLINE AND WARM FRONT DURING THE 01/21Z-02/00Z TIME FRAME. THIS APPEARS REASONABLE GIVEN OVERALL PATTERN AND ANTICIPATED HEATING/FORCING ALONG THE BOUNDARIES. EXPECT STORMS TO ERUPT WITHIN A KINEMATIC ENVIRONMENT EXTREMELY SUPPORTIVE OF SUPERCELLS WITH WEAK TO MODEST LOW LEVEL SSELY FLOW TOPPED BY INCREASINGLY STRONG SWLY FLOW ALOFT. FURTHERMORE... CONVECTION IS EXPECTED TO MOVE INTO STRONGER LOW LEVEL SHEAR NEAR THE WARM FRONT OVER SCNTRL KS/NWRN OK. TORNADOES...AND VERY LARGE HAIL AND HIGH WINDS COULD OCCUR WITH THIS ACTIVITY. FARTHER SOUTH...FROM NWRN OK INTO NWRN TX...SOMEWHAT WEAKER LARGE SCALE FORCING AND LOW LEVEL SHEAR MAY BE OFFSET BY GREATER INSTABILITY TO SUPPORT AT LEAST ISOLATED SUPERCELLS AHEAD OF THE DRYLINE WITH ATTENDANT THREATS OF TORNADOES AND VERY LARGE HAIL. A CLUSTER OR TWO OF SEVERE STORMS SHOULD EVOLVE THROUGH THE EVENING ACROSS PORTIONS OF OK/KS WITH ACTIVITY BEING SUSTAINED BY STRONG FORCING AND SHEAR NEAR THE SURFACE LOW AND WARM FRONT. THIS ACTIVITY WILL MOVE TOWARD THE MO VALLEY THROUGH LATE SATURDAY NIGHT...POSSIBLY BECOMING MORE ELEVATED WITH TIME BUT STILL POSING AT LEAST A HAIL THREAT AS FAR AS SWRN IA AND WRN MO INTO EARLY SUNDAY. ...NORTHEAST... STRONG COLD FRONT WILL SWEEP EAST FROM THE ERN GREAT LAKES EARLY IN THE DAY...AND ACROSS NEW ENGLAND THROUGH THE AFTERNOON. MARGINAL HEATING AND LOW TO MID 50S F DEWPOINTS AHEAD OF THE FRONT MAY RESULT IN MLCAPE VALUES OF UP TO 500 J/KG OVER PORTIONS OF THE MID HUDSON VALLEY...WITH WEAKER INSTABILITY NORTH AND EAST OF THIS AREA. FORCING APPEARS SUFFICIENT TO MAINTAIN A LINE OF LOW-TOPPED STORMS ON THE ADVANCING FRONT WITH UNIDIRECTIONAL SHEAR PROFILES FURTHER SUPPORTING UPDRAFT PERSISTENCE. RESULTING STORM MOTION AND AMBIENT FLOW SUGGEST WIND GUSTS WITH THE LINE OF STORMS MAY BE IN THE RANGE OF 40-50KT. IF GREATER INSTABILITY CAN DEVELOP THAN CURRENTLY ANTICIPATED...A SMALL SLGT RISK AREA MAY BE WARRANTED IN LATER OUTLOOKS. ..CARBIN.. 03/31/2006  From SWODY2 at goshenarc.org Fri Mar 31 17:27:29 2006 From: SWODY2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 31 Mar 2006 12:27:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 311728 SWODY2 SPC AC 311727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST FRI MAR 31 2006 VALID 011200Z - 021200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF SWRN KS...THE TX PNHDL...WRN OK AND NWRN TX... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY SWD INTO THE CNTRL AND SRN PLAINS...AND EWD INTO THE MID SOUTH... ...SYNOPSIS... PROGRESSIVE LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID AND UPPER-LEVEL TROUGH WHICH WILL MOVE FROM THE INTERMOUNTAIN W INTO THE GREAT PLAINS. DOWNSTREAM TROUGH NOW OVER THE UPPER MIDWEST WILL SHIFT EWD THROUGH THE NERN STATES. IN THE LOW-LEVELS...LEE CYCLOGENESIS IS FORECAST OVER THE NRN AND CNTRL HIGH PLAINS WITH THE PRIMARY SURFACE LOW EVENTUALLY CONSOLIDATING OVER ERN CO/WRN KS. DRY LINE WILL SHARPEN THROUGH THE DAY...LIKELY EXTENDING FROM WRN KS SWD INTO THE ERN TX PNHDL AND W-CNTRL TX BY LATE SATURDAY AFTERNOON. MEANWHILE...BAROCLINIC ZONE INITIALLY STALLED FROM THE MID S WWD TO ALONG THE RED RIVER VALLEY WILL RETREAT NWD THROUGH THE PERIOD AS SURFACE LOW DEEPENS OVER ERN CO. IN THE E...LOW PRESSURE WILL DEVELOP NEWD ACROSS SRN QUEBEC WHILE TRAILING COLD FRONT PUSHES EWD THROUGH THE HUDSON VALLEY...NEW ENGLAND AND MIDDLE ATLANTIC COASTAL PLAIN. ...CNTRL/SRN PLAINS INTO MID SOUTH... A POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE IS FORECAST SATURDAY AFTERNOON AND EVENING OVER PORTIONS OF SWRN KS...THE ERN TX PNHDL...WRN OK AND NWRN TX. HOWEVER...CAVEATS DO EXIST WHICH COULD AFFECT THE AMOUNT OF DESTABILIZATION THAT OCCURS E OF DRY LINE. THESE INCLUDE: 1) INFLUENCE OF WEAKER LEAD DISTURBANCES ON OVERNIGHT AND MORNING CONVECTION WHICH COULD DISRUPT WARM SECTOR...2) INCREASING MID AND HIGH CLOUDINESS...AND 3) QUALITY OF BOUNDARY-LAYER MOISTURE. ISOLATED TO SCATTERED TSTMS ARE EXPECTED TO BE ONGOING SATURDAY MORNING ALONG AND N OF STATIONARY BOUNDARY FROM PORTIONS OF MS/AL WWD ACROSS AR AND OK WITHIN PERSISTENT LOW-LEVEL WAA PATTERN. SOME OF THIS ACTIVITY WILL LIKELY PERSIST THROUGH DAY...WITH THE POTENTIAL FOR SEVERE WEATHER INCREASING BY AFTERNOON FROM THE MID SOUTH INTO ERN OK AS MOIST BOUNDARY-LAYER CONDITIONS CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF 1500-2500 J/KG. DESPITE SOME RELATIVE WEAKNESS IN MID AND HIGH-LEVEL WIND FIELDS...PRONOUNCED VEERING WITH HEIGHT COUPLED WITH THE MODERATE INSTABILITY AND RELATIVELY STEEP LAPSE RATES SUGGEST THE POTENTIAL FOR ORGANIZED/ROTATING UPDRAFTS CAPABLE OF DAMAGING WINDS...LARGE HAIL AND PERHAPS A COUPLE OF TORNADOES. MORE SIGNIFICANT SEVERE TSTM DEVELOPMENT IS ANTICIPATED BY MID TO LATE AFTERNOON FROM WARM FRONT/DRY LINE TRIPLE POINT SWD ALONG DRY LINE FROM WRN KS INTO THE TX PNHDL AND WRN OK. HERE...STEEP MID-LEVEL LAPSE RATES AND INCREASING BOUNDARY-LAYER MOISTURE ARE EXPECTED TO RESULT IN A MODERATELY UNSTABLE AIR MASS /MLCAPES 1500-2500 J/KG/. AS MENTIONED ABOVE...POSSIBLE INCREASE IN HIGH CLOUDS...ANY ONGOING STORMS ASSOCIATED WITH LEAD DISTURBANCES...ALONG WITH MIXING OF SHALLOW MOIST PROFILES COULD POTENTIALLY LIMIT THIS INSTABILITY. TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY WITHIN THIS CORRIDOR BETWEEN 21-00Z AS DRY LINE CIRCULATION STRENGTHENS AND DEEPENS AND WEAK HEIGHT FALLS AHEAD OF MID-LEVEL TROUGH SPREAD EWD INTO THE HIGH PLAINS. FORECAST SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF VERY LARGE HAIL AND TORNADOES. IN THIS TYPE OF PATTERN...POTENTIAL WILL EXIST FOR A FEW STRONG TORNADOES...ESPECIALLY BETWEEN 23-03Z WITH ANY SUPERCELLS THAT CAN REMAIN DISCRETE AND ROOTED IN THE BOUNDARY-LAYER OWING TO THE MARKED INCREASE IN LOW-LEVEL SHEAR AS LLJ INTENSIFIES. TSTMS WILL BECOME INCREASINGLY WIDESPREAD SATURDAY NIGHT NEWD INTO THE MID MO VALLEY ALONG BROADENING/STRENGTHENING LLJ. THE STRONGEST STORMS WILL REMAIN CAPABLE OF PRIMARILY DAMAGING WINDS AND LARGE HAIL. ...HUDSON VALLEY INTO NEW ENGLAND... CONSIDERABLE CLOUDS AND PRECIPITATION WILL LIMIT DESTABILIZATION AHEAD OF FRONT MOVING THROUGH REGION. HOWEVER...HEIGHT FALLS WILL CONTRIBUTE TO SOME WEAK INSTABILITY...SUPPORTING A LOOSELY ORGANIZED CONVECTIVE LINE OR LINE SEGMENTS. GIVEN THE RELATIVELY STRONG UNIDIRECTIONAL WIND FIELDS...SOME THREAT FOR LOCALIZED DAMAGING WINDS WILL EXIST FROM LATE MORNING THROUGH THE AFTERNOON. ..MEAD.. 03/31/2006