From SwoDy2 at goshenarc.org Thu May 4 06:03:16 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 02:03:16 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040600 SWODY2 SPC AC 040559 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CAROLINAS AND SE VA... ...SRN PLAINS/LOWER MS VALLEY... THE ZONAL FLOW PATTERN OVER THE ERN AND CNTRL U.S. WILL CONTINUE THROUGH FRIDAY AS A SHORTWAVE RIDGE AMPLIFIES SLIGHTLY OVER THE PLAINS AHEAD OF A SWRN U.S. TROUGH. AT THE SFC...A MOIST AXIS IS FORECAST TO BE IN PLACE ACROSS WRN AND CNTRL TX. SFC DEWPOINTS IN THE 50S F ALONG THIS AXIS SHOULD BE SUFFICIENT FOR MODERATE INSTABILITY ESPECIALLY ACROSS THE LOW-ROLLING PLAINS AND TX HILL COUNTRY BY MIDDAY FRIDAY. A LARGE MCS SHOULD BE ONGOING IN THE RED RIVER VALLEY WITH CLEARING PRESENT ACROSS THE LUBBOCK AND MIDLAND AREAS. THIS WILL BE THE MOST LIKELY LOCATION FOR STRONG THUNDERSTORM DEVELOPMENT IN THE AFTERNOON ALONG A FRONTAL BOUNDARY EXTENDING EWD ACROSS WCNTRL TX. STORM INITIATION WILL ALSO BE POSSIBLE FURTHER EAST ALONG THE BOUNDARY ACROSS NCNTRL TX AND THE LOWER MS VALLEY. SEVERAL MCS CLUSTERS APPEAR LIKELY TO DEVELOP AS STORMS INCREASE IN COVERAGE FRIDAY AFTERNOON AND EVENING. FRIDAY 21Z FORECAST SOUNDINGS SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES ACROSS TX WITH SHEAR PROFILES INCREASING SOME DURING THE DAY AS A SHORTWAVE TROUGH APPROACHES THE REGION FROM THE WEST. IN ADDITION...MID-LEVEL LAPSE RATES WILL STEEPEN AHEAD OF THE TROUGH. THIS COMBINED WITH THE INSTABILITY/SHEAR ENVIRONMENT SHOULD BE FAVORABLE FOR LARGE HAIL. A FEW OF THE STRONGER SUPERCELLS MAY ALSO BE CAPABLE OF PRODUCING A TORNADO AND VERY LARGE HAIL. ISOLATED WIND DAMAGE WILL ALSO BE LIKELY ESPECIALLY IN THE EVENING AS AN MCS ORGANIZES AND MOVES ESEWD INTO THE LOW-ROLLING PLAINS AND TX HILL COUNTRY. ...CAROLINAS... ZONAL FLOW WILL BE IN PLACE ACROSS THE ERN U.S. THROUGH FRIDAY AS A SFC LOW AND ASSOCIATED COLD FRONT MOVES SEWD INTO THE CNTRL APPALACHIANS AND CAROLINAS. SFC DEWPOINTS IN THE 50S F ALONG WITH SFC HEATING ACROSS THE REGION MAY BE SUFFICIENT FOR POCKETS OF MODERATE INSTABILITY SOUTH OF THE FRONT BY MIDDAY. AS A RESULT...THUNDERSTORM DEVELOPMENT APPEARS LIKELY IN THE AFTERNOON ALONG THE BOUNDARY IN THE SRN APPALACHIANS WITH ADDITIONAL STORMS INITIATING ON OR NEAR THE BOUNDARY ACROSS THE ATLANTIC COASTAL PLAINS. FORECAST SOUNDINGS FOR THIS AREA FRIDAY AFTERNOON SHOW MODERATE VERTICAL SHEAR WITH MLCAPE VALUES NEAR 1000 J/KG. ALTHOUGH LAPSE RATES WILL NOT BE PARTICULARLY STEEP...THE SHEAR AND INSTABILITY ENVIRONMENT SUGGESTS SUPERCELLS WILL BE POSSIBLE ESPECIALLY NEAR AREAS OF LOCALLY MAXIMIZED INSTABILITY. A THREAT OF LARGE HAIL AND ISOLATED WIND DAMAGE SHOULD BE GREATEST IN THE LATE AFTERNOON AND EARLY EVENING BEFORE STABILIZATION OCCURS DUE TO A LOSS OF SFC HEATING. ..BROYLES.. 05/04/2006  From SwoDy2 at goshenarc.org Thu May 4 17:14:56 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 13:14:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041712 SWODY2 SPC AC 041711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1211 PM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NM INTO PARTS OF THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL AND SRN PIEDMONT AND ATLANTIC COASTAL PLAIN... ...SYNOPSIS... AMPLIFIED...SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID-LEVEL TROUGH /CURRENTLY OVER CNTRL AND SRN CA/ WHICH WILL TRANSLATE EWD INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SOME UNCERTAINTY EXISTS WITH REGARD TO POSITION OF SYNOPTIC FRONT-OUTFLOW BOUNDARY COMPOSITE OVER TX. HOWEVER...IT DOES APPEAR THAT THIS BAROCLINIC ZONE WILL EXTEND GENERALLY FROM E-CNTRL NM SEWD THROUGH CNTRL TX INTO CNTRL LA BY FRIDAY AFTERNOON. ERN EXTENSION OF THIS FRONT WILL PUSH SEWD THROUGH THE TN VALLEY...CNTRL GULF COAST STATES AND CNTRL/SRN APPALACHIANS TO THE SERN ATLANTIC COAST THROUGH THE PERIOD. ...ERN NM / TX INTO THE LOWER MS VALLEY... 04/12Z OBSERVED SOUNDINGS ACROSS SRN TX INDICATE THAT LOW-LEVEL MOISTURE PROFILES HAVE IMPROVED OVER THE PAST 24 HOURS WITH MEAN MIXING RATIOS OF 13-14 G/KG. THIS MOISTURE WILL LIKELY REMAIN INTACT S OF COMPOSITE FRONTAL BOUNDARY...AND BENEATH STEEP MID-LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1500-2500 J/KG. STORMS ARE LIKELY TO BE ONGOING FRIDAY MORNING OVER PORTIONS OF NRN AND CNTRL TX NEAR OR N OF FRONTAL ZONE. THOUGH THIS ACTIVITY MAY UNDERGO SOME DIURNAL WEAKENING EARLY IN THE DAY...INTENSIFICATION IS EXPECTED BY AFTERNOON AS STORMS ENCOUNTER DESTABILIZING AIR MASS. POTENTIAL WILL EXIST FOR UPSCALE GROWTH INTO CLUSTERS OR A MCS WHICH WOULD MOVE SEWD INTO ERN/SERN TX AND LA FRIDAY AFTERNOON AND EVENING. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREATS. POTENTIAL FOR MORE SIGNIFICANT SEVERE STORMS IS EXPECTED BY AFTERNOON FARTHER TO THE W FROM ERN NM INTO WRN AND CNTRL TX AS HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH BEGIN TO OVERSPREAD WRN EXTENSION OF INSTABILITY AXIS. A BELT OF 40-50 KT WSWLY MID-LEVEL WINDS ARE FORECAST TO ACCOMPANY THIS TROUGH WITH VERTICAL SHEAR PROFILES BECOMING QUITE FAVORABLE FOR SUPERCELLS CAPABLE OF LARGE HAIL. TORNADO THREAT WILL BE LARGELY DEPENDENT ON MESOSCALE DETAILS...WITH THE BEST POTENTIAL WITH ANY MATURE SUPERCELLS INTERACTING FAVORABLY WITH PRE-EXISTING LOW-LEVEL BOUNDARIES. UPSCALE GROWTH INTO A MCS WILL LIKELY OCCUR FRIDAY NIGHT WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS SPREADING SEWD TOWARD THE TX COAST. ...SERN VA / CNTRL AND ERN NC / NERN SC... LATEST MODEL GUIDANCE CONTINUES TO INDICATE THAT INCREASING LOW-LEVEL MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS FRIDAY AFTERNOON AHEAD OF SURFACE FRONT WITH MLCAPES APPROACHING 1000-1500 J/KG. EXPECT THAT TSTMS WILL BECOME INCREASINGLY WIDESPREAD THROUGH THE AFTERNOON HOURS...WITH SOME POTENTIAL FOR A FEW ORGANIZED STORMS OWING TO MODEST DEEP-LAYER SHEAR /I.E. 25-30 KTS/ ON SRN PERIPHERY OF INTENSIFYING MID-LEVEL TROUGH OVER ERN CANADA INTO THE NERN STATES. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS THROUGH THE EVENING HOURS. THEREAFTER...STORMS SHOULD TEND TO WEAKEN WITH THE LOSS OF DAYTIME HEATING. ...MS / AL / GA... ADDITIONAL STORM CLUSTERS WILL LIKELY EVOLVE FRIDAY AFTERNOON ALONG AND S OF FRONTAL ZONE WITHIN MOIST AND MODERATELY UNSTABLE AIR MASS. MODEL GUIDANCE APPEARS TO HAVE PICKED UP ON MCV MOVING INTO THE ARKLATEX EARLY THIS AFTERNOON...WITH THIS FEATURE SLOWLY MOVING ESEWD ACROSS NRN AL INTO NRN GA AND SC THROUGH THE PERIOD. MORE CONCENTRATED TSTM ACTIVITY MAY OCCUR AHEAD OF THIS DISTURBANCE WITH THE POTENTIAL FOR MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THE PRIMARY FACTOR LIMITING A MORE ORGANIZED SEVERE THREAT APPEARS TO BE THE WEAK MID-LEVEL LAPSE RATES AND MARGINAL VERTICAL SHEAR. ..MEAD.. 05/04/2006  From SwoDy2 at goshenarc.org Thu May 4 17:32:58 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 13:32:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041730 SWODY2 SPC AC 041729 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NM INTO PARTS OF THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL AND SRN PIEDMONT AND ATLANTIC COASTAL PLAIN... CORRECTED FOR ERROR IN POINTS FILE ...SYNOPSIS... AMPLIFIED...SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID-LEVEL TROUGH /CURRENTLY OVER CNTRL AND SRN CA/ WHICH WILL TRANSLATE EWD INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SOME UNCERTAINTY EXISTS WITH REGARD TO POSITION OF SYNOPTIC FRONT-OUTFLOW BOUNDARY COMPOSITE OVER TX. HOWEVER...IT DOES APPEAR THAT THIS BAROCLINIC ZONE WILL EXTEND GENERALLY FROM E-CNTRL NM SEWD THROUGH CNTRL TX INTO CNTRL LA BY FRIDAY AFTERNOON. ERN EXTENSION OF THIS FRONT WILL PUSH SEWD THROUGH THE TN VALLEY...CNTRL GULF COAST STATES AND CNTRL/SRN APPALACHIANS TO THE SERN ATLANTIC COAST THROUGH THE PERIOD. ...ERN NM / TX INTO THE LOWER MS VALLEY... 04/12Z OBSERVED SOUNDINGS ACROSS SRN TX INDICATE THAT LOW-LEVEL MOISTURE PROFILES HAVE IMPROVED OVER THE PAST 24 HOURS WITH MEAN MIXING RATIOS OF 13-14 G/KG. THIS MOISTURE WILL LIKELY REMAIN INTACT S OF COMPOSITE FRONTAL BOUNDARY...AND BENEATH STEEP MID-LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1500-2500 J/KG. STORMS ARE LIKELY TO BE ONGOING FRIDAY MORNING OVER PORTIONS OF NRN AND CNTRL TX NEAR OR N OF FRONTAL ZONE. THOUGH THIS ACTIVITY MAY UNDERGO SOME DIURNAL WEAKENING EARLY IN THE DAY...INTENSIFICATION IS EXPECTED BY AFTERNOON AS STORMS ENCOUNTER DESTABILIZING AIR MASS. POTENTIAL WILL EXIST FOR UPSCALE GROWTH INTO CLUSTERS OR A MCS WHICH WOULD MOVE SEWD INTO ERN/SERN TX AND LA FRIDAY AFTERNOON AND EVENING. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREATS. POTENTIAL FOR MORE SIGNIFICANT SEVERE STORMS IS EXPECTED BY AFTERNOON FARTHER TO THE W FROM ERN NM INTO WRN AND CNTRL TX AS HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH BEGIN TO OVERSPREAD WRN EXTENSION OF INSTABILITY AXIS. A BELT OF 40-50 KT WSWLY MID-LEVEL WINDS ARE FORECAST TO ACCOMPANY THIS TROUGH WITH VERTICAL SHEAR PROFILES BECOMING QUITE FAVORABLE FOR SUPERCELLS CAPABLE OF LARGE HAIL. TORNADO THREAT WILL BE LARGELY DEPENDENT ON MESOSCALE DETAILS...WITH THE BEST POTENTIAL WITH ANY MATURE SUPERCELLS INTERACTING FAVORABLY WITH PRE-EXISTING LOW-LEVEL BOUNDARIES. UPSCALE GROWTH INTO A MCS WILL LIKELY OCCUR FRIDAY NIGHT WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS SPREADING SEWD TOWARD THE TX COAST. ...SERN VA / CNTRL AND ERN NC / NERN SC... LATEST MODEL GUIDANCE CONTINUES TO INDICATE THAT INCREASING LOW-LEVEL MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS FRIDAY AFTERNOON AHEAD OF SURFACE FRONT WITH MLCAPES APPROACHING 1000-1500 J/KG. EXPECT THAT TSTMS WILL BECOME INCREASINGLY WIDESPREAD THROUGH THE AFTERNOON HOURS...WITH SOME POTENTIAL FOR A FEW ORGANIZED STORMS OWING TO MODEST DEEP-LAYER SHEAR /I.E. 25-30 KTS/ ON SRN PERIPHERY OF INTENSIFYING MID-LEVEL TROUGH OVER ERN CANADA INTO THE NERN STATES. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS THROUGH THE EVENING HOURS. THEREAFTER...STORMS SHOULD TEND TO WEAKEN WITH THE LOSS OF DAYTIME HEATING. ...MS / AL / GA... ADDITIONAL STORM CLUSTERS WILL LIKELY EVOLVE FRIDAY AFTERNOON ALONG AND S OF FRONTAL ZONE WITHIN MOIST AND MODERATELY UNSTABLE AIR MASS. MODEL GUIDANCE APPEARS TO HAVE PICKED UP ON MCV MOVING INTO THE ARKLATEX EARLY THIS AFTERNOON...WITH THIS FEATURE SLOWLY MOVING ESEWD ACROSS NRN AL INTO NRN GA AND SC THROUGH THE PERIOD. MORE CONCENTRATED TSTM ACTIVITY MAY OCCUR AHEAD OF THIS DISTURBANCE WITH THE POTENTIAL FOR MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THE PRIMARY FACTOR LIMITING A MORE ORGANIZED SEVERE THREAT APPEARS TO BE THE WEAK MID-LEVEL LAPSE RATES AND MARGINAL VERTICAL SHEAR. ..MEAD.. 05/04/2006  From swody2 at goshenarc.org Fri May 5 06:01:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 May 2006 02:01:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050559 SWODY2 SPC AC 050558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI MAY 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CNTRL/ERN TX EWD INTO THE CNTRL GULF COASTAL AREA... ...CNTRL/ERN TX EWD TO THE CNTRL GULF COASTAL AREA... COMPLEX UPPER SYSTEM EJECTING SEWD FROM THE GRT BASIN WILL TRAVEL TO THE SRN PLAINS ON SATURDAY. A LEAD IMPULSE...NOW CROSSING THE DESERT SOUTHWEST...WILL LIKELY DRIVE AN MCS TO THE ERN TX/UPPER TX COAST FRI NIGHT INTO EARLY SATURDAY. IN ITS WAKE...ANOTHER IMPULSE CURRENTLY OVER NV...WILL ROTATE EWD INTO OK/NRN TX BY SATURDAY AFTERNOON. QUASI-STATIONARY FRONT EXPECTED TO LAY ACROSS THE LWR MS VLY WWD TO CNTRL TX LATER TODAY WILL LIKELY BE REINFORCED BY THE FRI NIGHT/EARLY SATURDAY MCS...PARTICULARLY OVER ERN TX AND THE LWR MS VLY. TAIL END OF THE FRONT MAY LIFT BACK NWD ACROSS CNTRL AND NRN TX SATURDAY AFTN AHEAD OF THE SECONDARY IMPULSE. IT IS UNCLEAR HOW UNSTABLE THE WARM SECTOR ACROSS THE LWR MS VLY WILL BECOME DOWNSTREAM OF THE OVERNIGHT MCS. LOW-LEVEL FLOW IS EXPECTED TO BE WEAK...BUT PRESENCE OF 60S BOUNDARY LAYER DEW POINTS AND 35-40 KTS OF MID-LEVEL FLOW SUGGESTS THAT A FEW STRONGER STORMS MAY DEVELOP SATURDAY AFTN/EVE FROM PARTS OF LA EWD TO SRN AL/WRN FL PNHDL. UPSTREAM...AIR MASS IS EXPECTED TO RECOVER WITH MID-UPPER 60S DEW POINTS LIKELY PRESENT ACROSS MOST OF CNTRL TX BY SATURDAY AFTERNOON. BOUNDARY LAYER IS EXPECTED TO WARM ALONG/AHEAD OF THE DRYLINE THAT SHOULD MIX EWD INTO THE WRN HILL COUNTRY AND S OF THE N TX BAROCLINIC ZONE. LOW-LEVEL FLOW IS EXPECTED TO REMAIN QUITE ANEMIC THROUGH THE DAY AS THE SECONDARY IMPULSE SWINGS EWD AND DEAMPLIFIES THROUGH N TX/OK. THE STRONGER MASS CONVERGENCE/HOTTEST BOUNDARY LAYER ACROSS CNTRL TX SHOULD CONTRIBUTE TO TSTM INITIATION BY EARLY-MID AFTN. THE STORMS SHOULD THEN DEVELOP MOVE ESEWD INTO ERN/SERN TX BY EVENING AND PERHAPS AS FAR EAST AS SRN LA BY 12Z SUNDAY. PRESENCE OF 40-50 KTS OF H5 FLOW AND STEEP MID-TROPOSPHERIC LAPSE RATES WILL BE FAVORABLE FOR SUPERCELLS EARLY IN THE LIFE CYCLE WITH LARGE HAIL AND POSSIBLY AN ISOLD TORNADO. ACTIVITY SHOULD EVOLVE INTO AN MCS OVERNIGHT ACCOMPANIED BY HIGH WINDS/HAIL... PRIMARILY ALONG SRN FLANKS OF THE MCS. ..RACY.. 05/05/2006  From swody2 at goshenarc.org Fri May 5 16:57:44 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 May 2006 12:57:44 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051655 SWODY2 SPC AC 051654 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1154 AM CDT FRI MAY 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL TX EWD TO THE CNTRL GULF COAST... ...SYNOPSIS... SPLIT FLOW REGIME WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FOCUS FOR SEVERE TSTM DEVELOPMENT BEING SRN STREAM SHORT WAVE TROUGH WHICH WILL TRANSLATE EWD FROM THE SRN PLAINS INTO THE LOWER MS VALLEY. IN THE LOW-LEVELS...POSITION OF PRIMARY SYNOPTIC FRONT WILL LIKELY BE MODULATED BY CONVECTION THAT OCCURS DURING THE DAY ONE PERIOD. HOWEVER...IN GENERAL...THIS FEATURE SHOULD EXTEND INITIALLY FROM LOW PRESSURE OVER CNTRL TX ESEWD TO NEAR THE CNTRL GULF COAST. MAIN FRONTAL WAVE IS FORECAST TO DEVELOP EWD ALONG BAROCLINIC ZONE INTO W-CNTRL MS BY SUNDAY MORNING. AS THIS OCCURS...LEADING PORTION OF BOUNDARY WILL RETREAT NWD...WHILE TRAILING PART SURGES SEWD AS A COLD FRONT. ...CNTRL/ERN TX EWD TO THE CNTRL GULF COAST... NUMEROUS TSTM CLUSTERS ARE EXPECTED TO BE ONGOING SATURDAY MORNING FROM CNTRL AND ERN TX INTO PARTS OF THE LOWER MS VALLEY WITHIN REGION OF FORCING FOR ASCENT AHEAD OF APPROACHING SHORT WAVE TROUGH. INFLUX OF MOIST AND MODERATELY UNSTABLE AIR MASS OVER S TX INTO SRN LA WILL LIKELY MAINTAIN THESE STORMS THROUGH THE PERIOD NEAR OR JUST TO THE N OF SURFACE BOUNDARY WITH A THREAT OF DAMAGING WINDS AND LARGE HAIL. POTENTIALLY MORE INTENSE STORM DEVELOPMENT IS EXPECTED BY AFTERNOON ALONG SRN FRINGE OF ONGOING CONVECTIVE ACTIVITY NEAR OR S OF FRONTAL WAVE OVER CNTRL INTO ERN OR SERN TX. HERE...DEWPOINTS IN THE UPPER 60S TO LOWER 70S COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO MLCAPES OF 1000-2000 J/KG. THIS INSTABILITY IN CONJUNCTION WITH RELATIVELY STRONG LOW AND DEEP LAYER SHEAR SHOULD SUPPORT SUPERCELLS AND BOWING SEGMENTS WITH A THREAT OF DAMAGING WINDS...LARGE HAIL AND A FEW TORNADOES. THESE MORE INTENSE STORMS WILL MOVE/DEVELOP EWD OR SEWD INTO PORTIONS OF CNTRL/SRN LA SATURDAY NIGHT...PERHAPS AS FAR E AS SRN MS INTO SWRN AL. FARTHER TO THE N OVER CNTRL AND NRN MS...KINEMATIC ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SUPERCELLS OVERNIGHT. HOWEVER...THERE IS SOME UNCERTAINTY WITH REGARD TO THE NWD EXTENT OF AIR MASS DESTABILIZATION. ..MEAD.. 05/05/2006  From swody2 at goshenarc.org Sat May 6 06:02:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 May 2006 02:02:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060559 SWODY2 SPC AC 060558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SAT MAY 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL GULF COASTAL AREA INTO THE SERN STATES... ...CNTRL GULF COASTAL AREA/SERN STATES... UPPER FLOW REGIME WILL CONTINUE TO FAVOR AN ACTIVE SRN STREAM INTO SUNDAY. THE MID-LEVEL IMPULSE OBSERVED IN WATER VAPOR IMAGERY OVER THE SRN GRT BASIN EARLY SATURDAY MORNING IS EXPECTED TO MOVE ACROSS THE SRN PLAINS SATURDAY...THEN INTO THE SERN STATES BY SUNDAY NIGHT. THE SFC FRONT SITUATED FROM THE CAROLINAS SWWD ALONG THE GULF COAST SHOULD REMAIN ESSENTIALLY IN PLACE THROUGH SATURDAY. A WEAK LOW SHOULD FORM ALONG THE FRONT ACROSS THE LWR MS VLY BY 12Z SUNDAY... THEN TRACK ENEWD INTO THE LWR TN VLY BY EARLY MONDAY. TO THE EAST OF THE LOW...THE FRONT SHOULD GRADUALLY TRANSLATE NWD AS A WARM FRONT INTO CNTRL AL AND CNTRL GA SUNDAY AFTN...BUT LIKELY BE REINFORCED BY A WEDGE FRONT ALONG THE FOOT OF THE SRN APPALACHIANS. THERE WILL LIKELY BE WARM ADVECTION DERIVED RAIN/CLOUDS ALONG/N OF THE BAROCLINIC ZONE ACROSS THE LWR TN VLY AND SRN APPALACHIANS EARLY SUNDAY. IT IS NOT ENTIRELY CLEAR HOW UNSTABLE THE WARM SECTOR WILL BECOME S OF THE FRONT SUNDAY AFTN...BUT PRESENCE OF MID-UPPER 60S DEW POINTS AND POTENTIAL FOR HEATING...BOUNDARY LAYER SHOULD BECOME UNSTABLE GIVEN MODEST H5-H7 LAPSE RATES. LITTLE CAP AND FORCING FOR ASCENT ASSOCIATED WITH THE H5 IMPULSE WILL BE FAVORABLE FOR TSTMS TO FORM SUNDAY AFTN FROM SERN MS/ERN LA NEWD INTO CNTRL/SRN PARTS OF AL/GA. SUPERCELLS WILL BE POSSIBLE GIVEN 40+ KTS OF EFFECTIVE SHEAR WITH LARGE HAIL AND DAMAGING WIND GUSTS. TORNADOES WILL BE POSSIBLE...ESPECIALLY ACROSS CNTRL AL INTO SWRN GA ALONG THE WARM/WEDGE FRONT. HIGHER SEVERE PROBABILITIES MAY BE WARRANTED IN FUTURE OUTLOOKS...ONCE THE MAGNITUDE OF INSTABILITY BECOMES CLEARER. ...CNTRL/SRN HIGH PLAINS... MUCH OF THE SRN PLAINS IS EXPECTED TO RESIDE BENEATH LARGE SCALE RIDGING THROUGH MOST OF SUNDAY IN WAKE OF THE DISTURBANCE THAT WILL BE MOVING INTO THE DEEP SOUTH. BUT...A LOW-AMPLITUDE POSITIVE TILT SRN STREAM IMPULSE WILL APPROACH THE CNTRL/SRN HIGH PLAINS BY PEAK HEATING. RETURN FLOW WILL BRING MODEST MOISTURE NWWD INTO ERN NM AND ALONG A LEE-TROUGH NWD INTO WRN NEB. HEATING...WEAK ASCENT AND STEEP LAPSE RATES WILL BE FAVORABLE HIGH BASED TSTMS. VERTICAL SHEAR WILL REMAIN WEAK...BUT STRONGER STORMS WILL BE CAPABLE OF LARGE HAIL. ONE OR MORE WEAK MCS/S MAY EVOLVE SUNDAY NIGHT...MOVING EWD INTO NEB AND PARTS OF THE TX PNHDL. ...NRN PLAINS... FAST NRN STREAM FLOW IS EXPECTED TO CARRY SEVERAL DISTURBANCES EWD FROM THE N PAC BASIN EWD ACROSS THE INTERMOUNTAIN WEST AND INTO THE NRN PLAINS THROUGH SUNDAY. A NARROW RIBBON OF BOUNDARY LAYER MOISTURE WILL ADVECT NWD INTO THE ERN DAKS ALONG/EAST OF A LEE TROUGH AND BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES. AS LARGE SCALE ASCENT SPREADS EWD FROM AN UPSTREAM TROUGH...TSTMS WILL DEVELOP ALONG THE LEE-TROUGH AND ALONG THE APPROACHING COLD FRONT. VERTICAL SHEAR WILL BE SOMEWHAT WEAK...BUT GIVEN THE STEEP LAPSE RATES...ISOLD HAIL OR DAMAGING WINDS COULD OCCUR WITH THE STRONGER STORMS. ..RACY.. 05/06/2006  From swody2 at goshenarc.org Sat May 6 17:33:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 May 2006 13:33:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061729 SWODY2 SPC AC 061728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 PM CDT SAT MAY 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST TO THE SC/GA COASTS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...SYNOPSIS... PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH SRN STREAM IMPULSE TRANSLATING EWD THROUGH THE TN VALLEY AND CNTRL GULF COAST TO THE CNTRL/SRN ATLANTIC COAST. MEANWHILE...NRN BRANCH SHORT WAVE TROUGH WILL SHIFT EWD FROM THE NRN AND CNTRL ROCKIES INTO THE HIGH PLAINS REGION SUNDAY AFTERNOON INTO EVENING...WHILE SRN STREAM POSITIVE TILT TROUGH MORE SLOWLY MOVES EWD THROUGH THE SRN ROCKIES INTO SRN HIGH PLAINS. IN THE LOW-LEVELS...SEVERAL FRONTAL WAVES WILL DEVELOP EWD ALONG BAROCLINIC ZONE FROM CNTRL MS/AL TO SRN SC...WITH PRIMARY SURFACE LOW CONSOLIDATING OVER SC NEWD INTO THE GULF STREAM SUNDAY NIGHT. TO THE W...LEE TROUGH WILL INTENSIFY OVER THE HIGH PLAINS WITH PACIFIC COLD FRONT EVENTUALLY OVERTAKING THIS FEATURE OVER THE WRN DAKOTAS INTO NEB SUNDAY AFTERNOON INTO EVENING. ...CNTRL GULF COAST NEWD THROUGH CNTRL/SRN GA INTO SRN SC... CLUSTERS OF TSTMS ARE EXPECTED TO BE ONGOING SUNDAY MORNING INVOF FRONTAL ZONE OVER THE CNTRL AND ERN GULF STATES WITH REGION OF LARGE-SCALE FORCING FOR ASCENT AHEAD OF SRN STREAM SHORT WAVE TROUGH. DESPITE RELATIVELY POOR LAPSE RATES...INFLUX OF A MOIST LOW-LEVEL AIR MASS SHOULD MAINTAIN THIS CONVECTION EWD TOWARD THE ATLANTIC COAST SUNDAY AFTERNOON INTO EVENING. PRIMARY UNCERTAINTY IS DEGREE OF INSTABILITY THAT WILL DEVELOP WITHIN THIS REGION OF STRONGER SYNOPTIC-SCALE FORCING AHEAD OF MAIN SHORT WAVE TROUGH GIVEN ANTICIPATED WIDESPREAD CLOUDS AND PRECIPITATION. IT APPEARS BETTER POTENTIAL FOR AIR MASS DESTABILIZATION WILL OCCUR ALONG SRN PERIPHERY OF CLOUD/PRECIPITATION SHIELD FROM ERN LA/SRN MS INTO CNTRL/SRN PORTIONS OF AL AND GA WHERE LOCALLY STRONGER DIABATIC HEATING COUPLED WITH DEWPOINTS IN THE 60S WILL CONTRIBUTE TO MLCAPES OF 1000-1500 J/KG. WHILE STRONGER FORCING MAY HAVE ALREADY SHIFTED E OF THE SRN APPALACHIANS...SUSTAINED LOW-LEVEL CONVERGENCE ALONG FRONT SHOULD BE SUFFICIENT TO SUPPORT ORGANIZED STORM DEVELOPMENT. LARGELY UNIDIRECTIONAL VERTICAL SHEAR OF 40-45 KTS SUGGESTS POTENTIAL FOR BOWING SEGMENTS OR SPLITTING SUPERCELLS CAPABLE OF LOCALLY DAMAGING WINDS...MARGINAL HAIL AND PERHAPS A COUPLE OF TORNADOES. CONDITIONAL SLIGHT RISK HAS BEEN EXTENDED EWD TO THE SC COAST GIVEN POTENTIAL FOR SOME DESTABILIZATION NEAR DEEPENING SURFACE LOW WHERE SHEAR PROFILES WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF A COUPLE TORNADOES AND DAMAGING WINDS. ...SWRN NEB SWD TO THE TX PNHDL... DESPITE STRENGTHENING SLY LOW-LEVEL FLOW AHEAD OF INTENSIFYING LEE TROUGH...BOUNDARY-LAYER MOISTURE WILL REMAIN LIMITED WITH DEWPOINTS IN THE MID 40S TO LOWER 50S. HOWEVER...STEEPENING LOW TO MID-LEVEL LAPSE RATES WILL LARGELY CONTRIBUTE TO AIR MASS DESTABILIZATION SUNDAY AFTERNOON WITH MLCAPES APPROACHING 1000 J/KG. INCREASED LARGE-SCALE FORCING ASSOCIATED WITH APPROACHING SHORT WAVE TROUGH COUPLED WITH DAYTIME HEATING AND CONVERGENCE ALONG LEE TROUGH WILL SUPPORT TSTM DEVELOPMENT BY LATE AFTERNOON FROM WRN NEB SWD THROUGH ERN CO/WRN KS INTO NERN NM AND THE TX PNHDL. INSPECTION OF FORECAST SOUNDINGS SUGGESTS THAT REGION DELINEATED BY HIGHER SEVERE PROBABILITIES AND CATEGORICAL SLIGHT RISK WILL HAVE AT LEAST MODEST DEEP-LAYER VERTICAL SHEAR /25-35 KTS/ WHICH WILL SUPPORT A FEW ORGANIZED SEVERE STORMS CAPABLE OF SEVERE HAIL AND DAMAGING WINDS. EVOLUTION INTO CLUSTERS OR AN MCS MAY OCCUR SUNDAY NIGHT OVER CNTRL KS INTO THE ERN TX PNHDL/WRN OK...THOUGH WEAKENING INSTABILITY WITH THE ONSET OF NOCTURNAL COOLING SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT FARTHER TO THE E. ...WRN/SWRN TX... BELT OF RELATIVELY STRONG MID AND HIGH-LEVEL FLOW WILL BE MAINTAINED ACROSS REGION IN ASSOCIATION WITH MORE ACTIVE SRN BRANCH OF WESTERLIES. PRIMARY UNCERTAINTY IS INITIATION OF DEEP CONVECTION OWING TO STRONGER CAP AND APPARENT LATER ARRIVAL OF NEXT UPSTREAM IMPULSE. SHOULD STORMS DEVELOP AND BECOME SUSTAINED ALONG LEE TROUGH OR WRN EXTENSION OF REMNANT STATIONARY BOUNDARY...THE MODERATELY STRONG DEEP-LAYER SHEAR AND MODEST INSTABILITY WOULD SUPPORT A THREAT OF ORGANIZED/ROTATING UPDRAFTS CAPABLE OF LARGE HAIL AND LOCALLY STRONG WINDS. AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...DAKOTAS... TSTMS ARE EXPECTED TO DEVELOP BY MID TO LATE AFTERNOON ALONG LEE TROUGH OR PACIFIC COLD FRONT WITHIN STEEP LAPSE RATES ENVIRONMENT CHARACTERIZED BY MLCAPES OF 500-1000 J/KG. A FEW OF THE STORMS WILL BE CAPABLE OF MARGINALLY SEVERE WIND/HAIL...BUT RELATIVELY WEAK VERTICAL SHEAR SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 05/06/2006  From swody2 at goshenarc.org Sun May 7 06:01:44 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 May 2006 02:01:44 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070558 SWODY2 SPC AC 070558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SUN MAY 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL PLAINS AND LWR MO RVR VLY... ...SYNOPSIS... MAIN BELT OF THE POLAR VLYS WILL BEGIN TO STRENGTHEN EARLY NEXT WEEK AS A LARGE SCALE RIDGE BUILDS ACROSS THE N PAC BASIN AND FORCES A DOWNSTREAM TROUGH TO EVOLVE ACROSS THE NRN INTERMOUNTAIN WEST. THIS TROUGH/STRONGER FLOW WILL PROGRESS TO THE NRN/CNTRL PLAINS BY MON NIGHT. DOWNSTREAM...A SPLIT FLOW REGIME WILL CONTINUE WITH SEVERAL SRN STREAM DISTURBANCES TRANSLATING ACROSS THE SRN PLAINS AND DEEP S. AT THE SFC...WRN END OF A WEAK FRONT ALONG THE GULF COAST WILL BEGIN TO REDEVELOP NWD THROUGH THE SRN PLAINS AHEAD OF THE WRN STATES TROUGH. LEE-TROUGH IN THE CNTRL/NRN PLAINS MON MORNING WILL EVENTUALLY BE OVERTAKEN BY A COLD FRONT BY MON NIGHT FROM THE ERN DAKS SWD INTO ERN NEB AND CNTRL KS. THIS FRONT WILL THEN MOVE SEWD TOWARD THE UPPER MS VLY AND SWD INTO THE SRN HIGH PLAINS BY 12Z TUE. ...CNTRL/NRN PLAINS... SLY LOW-LEVEL FLOW WILL ADVECT BOUNDARY LAYER MOISTURE NWD THROUGH THE PLAINS DURING THE NEXT COUPLE OF DAYS AHEAD OF THE DEVELOPING NRN STREAM TROUGH. BY MON AFTN...50S SFC DEW POINTS WILL BE COMMON AS FAR N AS THE ERN DAKS/WRN MN WITH 60S INTO THE LWR MO VLY/CNTRL PLAINS. HEATING ALONG/AHEAD OF THE LEE-TROUGH/COLD FRONT WILL CONTRIBUTE TO MODEST INSTABILITY WITH MLCAPES OF 500-1500 J/KG. AS LARGE SCALE ASCENT SPREADS SEWD AND THE COLD FRONT STRENGTHENS...TSTMS WILL LIKELY DEVELOP ACROSS WRN MN SWWD INTO SERN SD BY MID-AFTN. ACTIVITY WILL PROBABLY BACKBUILD SWWD INTO CNTRL/ERN NEB AND PARTS OF KS DURING THE EVENING. VERTICAL SHEAR WILL BE RATHER WEAK UNTIL EVENING WHEN IT IS EXPECTED TO INCREASE INTO THE 35-40 KT RANGE...SUFFICIENT FOR BRIEF SUPERCELL STRUCTURES. ACTIVITY WILL PROBABLY BECOME LINEAR QUICKLY AND MOVE TOWARD THE UPPER MS VLY AND CORN BELT OVERNIGHT...WITH DECREASING SEVERE RISKS. SRN END OF THE LINE MAY DEVELOP INTO A STRONGER MCS AND PROPAGATE SEWD INTO SRN KS AND NRN OK BY EARLY TUE WITH LOW HAIL PROBABILITIES. ...SRN PLAINS... AN MCS WILL LIKELY BE ONGOING EARLY IN THE PERIOD ACROSS OK AND ERN TX ALONG THE NOSE OF A 30-40 KT SLY LLJ. THIS MCS WILL PROBABLY MOVE EWD INTO THE OZARKS AND THE LWR MS VLY DURING THE DAY AND WEAKEN. IN WAKE OF THIS MCS...SUBSIDENCE AND LARGE SCALE RIDGING/WARMING ALOFT WILL LIKELY SUPPRESS CONVECTIVE CHANCES ALONG THE WARM FRONT/DRYLINE ACROSS CNTRL/NRN TX AND SWRN OK DURING MON AFTN. BUT...STRONG HEATING AND PERSISTENT/WEAK CONVERGENCE ALONG BOUNDARIES MAY BE SUFFICIENT FOR ISOLD TSTMS TO DEVELOP ACROSS PARTS OF CNTRL/NRN TX EWD INTO SWRN LA LATE MON AFTN. GIVEN A STORM...50 KTS OF EFFECTIVE SHEAR AND STEEP LAPSE RATES WILL BE FAVORABLE FOR PRIMARILY LARGE HAIL. ..RACY.. 05/07/2006  From swody2 at goshenarc.org Sun May 7 17:20:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 May 2006 13:20:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071718 SWODY2 SPC AC 071717 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 PM CDT SUN MAY 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE ARKLATEX... ...SYNOPSIS... MID-LEVEL TROUGH INITIALLY OVER THE CANADIAN AND NRN ROCKIES WILL INTENSIFY THROUGH THE FORECAST PERIOD AS IT TRANSLATES SEWD INTO THE NRN PLAINS ALONG CYCLONIC SIDE OF UPPER JET STREAK DIVING SEWD TOWARD THE CNTRL ROCKIES. MEANWHILE...SRN STREAM IMPULSE /INITIALLY OVER CNTRL KS INTO N-CNTRL TX/ WILL PROGRESS ESEWD TOWARD THE LOWER MS VALLEY. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH NRN PLAINS SHORT WAVE TROUGH WILL DEVELOP SEWD FROM CNTRL SASKATCHEWAN INTO SRN MANITOBA WITH TRAILING COLD FRONT LIKELY EXTENDING FROM THE RED RIVER VALLEY OF THE N SWWD INTO SWRN NEB BY LATE AFTERNOON. A LEE TROUGH OR DRY LINE WILL STRETCH SEWD FROM ITS INTERSECTION WITH COLD FRONT OVER SWRN NEB SWD THROUGH WRN OR CNTRL KS INTO WRN OK AND W-CNTRL TX. FARTHER SE...QUASI-STATIONARY BOUNDARY WILL EXTEND FROM NRN FL WWD ALONG THE GULF COAST...WITH WRN EXTENSION OF BOUNDARY RETREATING NWD THROUGH RED RIVER VALLEY OF THE S. ...NRN AND CNTRL PLAINS... DESPITE INCREASING SLY FLOW AHEAD OF COLD FRONT...LOW-LEVEL MOISTURE WILL REMAIN SOMEWHAT LIMITED WITH DEWPOINTS OF 45-55 F. HOWEVER...THE PRESENCE OF MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES WILL COMPENSATE TO SOME DEGREE FOR THE MARGINAL MOISTURE...WITH MLCAPES INCREASING TO 500-1500 J/KG. TSTMS WILL BECOME INCREASINGLY LIKELY BY AFTERNOON INITIALLY ALONG NRN EXTENSION OF COLD FRONT OVER THE ERN DAKOTAS/WRN MN WITH SUBSEQUENT DEVELOPMENT SWWD INTO CNTRL/ERN NEB BY LATE AFTERNOON OR EARLY EVENING. DEEP-LAYER SHEAR IS FORECAST TO BE MARGINALLY SUPPORTIVE /25-35 KTS/ OF ORGANIZED SEVERE STORMS WITH THE PRIMARY THREATS BEING SEVERE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONAL STORMS MAY ALSO DEVELOP SWD ALONG SRN PORTION OF COLD FRONT AND/OR LEE TROUGH/DRY LINE INTO KS LATE MONDAY AFTERNOON INTO EVENING. HERE TOO...DEEP-LAYER SHEAR WILL BE MARGINAL THOUGH LARGE HAIL/STRONG WINDS WILL REMAIN POSSIBLE WITH THE STRONGEST CELLS. ...SRN PLAINS INTO LOWER MS VALLEY... MORE UNCERTAINTY EXISTS ACROSS THIS REGION OWING TO POTENTIAL EFFECTS OF ONGOING STORMS MONDAY MORNING OVER OK INTO N TX AND TIMING OF WEAKER SRN STREAM IMPULSE. CLOSE PROXIMITY OF RICH BOUNDARY-LAYER MOISTURE /UPPER 60 TO LOWER 70S DEWPOINTS CURRENTLY OVER SERN TX/SRN LA/ SHOULD SUPPORT AIR MASS DESTABILIZATION /MLCAPES OF 1000-2000 J/KG/ ALONG AND S OF FRONTAL BOUNDARY WHICH WILL RETREAT NWD THROUGH THE SRN LOW PLAINS. AS MENTIONED ABOVE...STORM CLUSTERS OR AN MCS WILL LIKELY BE ONGOING OVER PORTIONS OF OK AND PERHAPS N TX MONDAY MORNING IN ADVANCE OF SRN STREAM IMPULSE. SOME DIURNAL WEAKENING MAY OCCUR THROUGH THE MORNING...WITH STORM RE-INTENSIFICATION OR NEW DEVELOPMENT ALONG SRN EDGE OF COLD POOL BY AFTERNOON OVER THE ARKLATEX. THE STRONGER FORCING FOR ASCENT ASSOCIATED WITH AFOREMENTIONED SHORT WAVE TROUGH WILL LIKELY HAVE SHIFTED E OF THE REGION BY THIS TIME...BUT MESOSCALE FORCING ALONG OUTFLOW BOUNDARY AND SYNOPTIC FRONT MAY BE SUFFICIENT TO MAINTAIN ANY DEVELOPING DEEP CONVECTION. SHOULD STORMS BECOME SUSTAINED...FORECAST VERTICAL SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS WITH 45-55 KTS OF DEEP-LAYER SHEAR AND 0-1 KM SRH OF 100-200 M2/S2. POTENTIAL WILL EXIST FOR LARGE HAIL...DAMAGING WINDS AND A FEW TORNADOES WITH THE MOST INTENSE STORMS. UNCERTAINTY IN DEVELOPMENT AND MAINTENENCE OF STORMS PRECLUDES HIGHER SEVERE PROBABILITIES. ..MEAD.. 05/07/2006  From swody2 at goshenarc.org Mon May 8 06:02:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 02:02:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080559 SWODY2 SPC AC 080558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS...THE MID MS VLY AND THE OZARKS... ...SYNOPSIS... A BROAD UPPER LEVEL TROUGH WILL CONTINUE TO PROGRESS EWD ACROSS THE COUNTRY ON TUE. NUMEROUS MID-LEVEL SHORTWAVE TROUGHS WILL BE EMBEDDED IN THE WNWLY FLOW REGIME...WITH THE STRONGEST TRANSLATING FROM THE NRN ROCKIES INTO THE UPPER MS VLY BY TUE NIGHT. A WEAKER JET STREAK WILL MIGRATE FROM THE GRT BASIN EARLY TUE TO THE CNTRL/SRN PLAINS TUE NIGHT. AT THE SFC...A MYRAID OF CONVECTIVE BOUNDARIES WILL BE IN PLACE EARLY TUE ACROSS THE CNTRL PORTIONS OF THE COUNTRY. MAIN SYNOPTIC FRONTS WILL INCLUDE A RETREATING WARM FRONT ACROSS SRN OK SEWD INTO THE DEEP SOUTH. A COLD FRONT WILL MOVE EWD INTO THE UPPER MS VLY...THEN SWWD INTO THE SRN HIGH PLAINS BY TUE NIGHT. A DRY LINE WILL MIX EWD INTO SRN OK SWWD INTO CNTRL TX. ...CNTRL/SRN PLAINS EWD INTO THE OZARKS... EVOLUTION OF TSTM CLUSTERS ACROSS THE PLAINS ON MON AND MON NIGHT WILL PLAY A ROLE IN THE SEVERE SCENARIOS TUE AND TUE NIGHT. THUS...CONFIDENCE IS LOWER THAN AVERAGE. IT APPEARS THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. COMPOSITE OUTFLOW BOUNDARY SHOULD REINFORCE THE RETREATING WARM FRONT FROM SRN OK SEWD INTO SRN AR. NRN PART OF THE MCS WILL PROBABLY WEAKEN AS IT MOVES BEYOND THE INSTABILITY AXIS...BUT THE LONGEVITY/SEVERITY OF THE SRN PORTION OF THE MCS IS NOT CLEAR. GIVEN THE SWLY LLJ FEEDING VERY UNSTABLE PARCELS INTO THE SWRN FLANK...IT IS CONCEIVABLE THAT STORMS MAY BACKBUILD MOST OF THE DAY ACROSS ERN OK AND WRN AR WITH THREATS FOR VERY LARGE HAIL. IF THE MCS WEAKENS...SFC DEW POINTS IN THE MID-UPPER 60S WILL LIKELY SURGE BETWEEN THE BUBBLE HIGH ACROSS THE OZARKS AND EAST OF A TRIPLE POINT LOW OVER CNTRL OK NWD TO THE SWD MOVING COLD FRONT IN SERN KS AND SWRN MO. H7-H5 LAPSE RATES AOA 8 DEG C PER KM AND HEATING WILL BOOST MLCAPES AOA 2500 J/KG IN THIS ZONE DURING PEAK HEATING. MOREOVER...ENELY UPSLOPE FLOW N OF THE COLD FRONT WILL MAINTAIN AT LEAST 50S DEW POINTS WWD INTO THE TX PNHDL/SWRN KS. THOUGH THERE MAY BE SOME SUBSIDENCE IN WAKE OF THE MCS AND EVIDENCE OF STRONG CINH ALONG/AHEAD OF THE TRIPLE POINT/ DRYLINE...FLOW ALOFT WILL BECOME MORE CYCLONIC BY EVENING AND RESULT IN ADDITIONAL TSTMS TO FORM...BOTH ALONG/N OF THE COLD FRONT FROM THE SRN HIGH PLAINS NEWD ACROSS SRN KS INTO PARTS OF MO...THEN SWD ALONG THE DRYLINE INTO OK. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL BE POSSIBLE...MAINLY ACROSS PARTS OF ERN OK...THOUGH THE SELY LOW-LEVEL FLOW MAY BE RATHER WEAK. FARTHER S...TSTMS WILL LIKELY BE MORE ISOLD ALONG THE DRYLINE INTO CNTRL TX. CINH IS EXPECTED TO BE RATHER STRONG AND THE UPPER FLOW REGIME SOMEWHAT ANTICYLONIC DURING MOST OF THE PEAK HEATING HOURS. BUT...THE BOUNDARY LAYER SHOULD BECOME RATHER HOT AND COULD ALLOW PARCELS TO BREECH THE CAP. SUPERCELLS WILL BE POSSIBLE AND A CONDITIONAL SLGT RISK WILL EXIST ALONG THE DRYLINE. SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY DOWNSTREAM FROM THE OZARKS INTO THE LWR MS VLY AND UPSTREAM FROM THE SRN HIGH PLAINS INTO OK/N TX. THESE STORMS MAY HAVE A NOCTURNAL THREAT FOR HAIL/HIGH WINDS. LASTLY...A WEAKER MCS MAY EVOLVE FROM PARTS OF ERN WY/CO INTO WRN NEB. ISOLD HAIL MAY OCCUR WITH THE STRONGER STORMS...MAINLY ACROSS CO. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING WITH RESPECT TO THE WARM SECTOR ORIENTATION...EVOLUTION INTO LINE SEGMENTS IS LIKELY EARLY IN THE TSTM LIFE CYCLES. ISOLD DAMAGING WINDS/HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT THE SEVERE THREAT SHOULD WANE DURING THE EVENING HOURS. ..RACY.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 06:02:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 02:02:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080559 SWODY2 SPC AC 080558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS...THE MID MS VLY AND THE OZARKS... ...SYNOPSIS... A BROAD UPPER LEVEL TROUGH WILL CONTINUE TO PROGRESS EWD ACROSS THE COUNTRY ON TUE. NUMEROUS MID-LEVEL SHORTWAVE TROUGHS WILL BE EMBEDDED IN THE WNWLY FLOW REGIME...WITH THE STRONGEST TRANSLATING FROM THE NRN ROCKIES INTO THE UPPER MS VLY BY TUE NIGHT. A WEAKER JET STREAK WILL MIGRATE FROM THE GRT BASIN EARLY TUE TO THE CNTRL/SRN PLAINS TUE NIGHT. AT THE SFC...A MYRAID OF CONVECTIVE BOUNDARIES WILL BE IN PLACE EARLY TUE ACROSS THE CNTRL PORTIONS OF THE COUNTRY. MAIN SYNOPTIC FRONTS WILL INCLUDE A RETREATING WARM FRONT ACROSS SRN OK SEWD INTO THE DEEP SOUTH. A COLD FRONT WILL MOVE EWD INTO THE UPPER MS VLY...THEN SWWD INTO THE SRN HIGH PLAINS BY TUE NIGHT. A DRY LINE WILL MIX EWD INTO SRN OK SWWD INTO CNTRL TX. ...CNTRL/SRN PLAINS EWD INTO THE OZARKS... EVOLUTION OF TSTM CLUSTERS ACROSS THE PLAINS ON MON AND MON NIGHT WILL PLAY A ROLE IN THE SEVERE SCENARIOS TUE AND TUE NIGHT. THUS...CONFIDENCE IS LOWER THAN AVERAGE. IT APPEARS THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. COMPOSITE OUTFLOW BOUNDARY SHOULD REINFORCE THE RETREATING WARM FRONT FROM SRN OK SEWD INTO SRN AR. NRN PART OF THE MCS WILL PROBABLY WEAKEN AS IT MOVES BEYOND THE INSTABILITY AXIS...BUT THE LONGEVITY/SEVERITY OF THE SRN PORTION OF THE MCS IS NOT CLEAR. GIVEN THE SWLY LLJ FEEDING VERY UNSTABLE PARCELS INTO THE SWRN FLANK...IT IS CONCEIVABLE THAT STORMS MAY BACKBUILD MOST OF THE DAY ACROSS ERN OK AND WRN AR WITH THREATS FOR VERY LARGE HAIL. IF THE MCS WEAKENS...SFC DEW POINTS IN THE MID-UPPER 60S WILL LIKELY SURGE BETWEEN THE BUBBLE HIGH ACROSS THE OZARKS AND EAST OF A TRIPLE POINT LOW OVER CNTRL OK NWD TO THE SWD MOVING COLD FRONT IN SERN KS AND SWRN MO. H7-H5 LAPSE RATES AOA 8 DEG C PER KM AND HEATING WILL BOOST MLCAPES AOA 2500 J/KG IN THIS ZONE DURING PEAK HEATING. MOREOVER...ENELY UPSLOPE FLOW N OF THE COLD FRONT WILL MAINTAIN AT LEAST 50S DEW POINTS WWD INTO THE TX PNHDL/SWRN KS. THOUGH THERE MAY BE SOME SUBSIDENCE IN WAKE OF THE MCS AND EVIDENCE OF STRONG CINH ALONG/AHEAD OF THE TRIPLE POINT/ DRYLINE...FLOW ALOFT WILL BECOME MORE CYCLONIC BY EVENING AND RESULT IN ADDITIONAL TSTMS TO FORM...BOTH ALONG/N OF THE COLD FRONT FROM THE SRN HIGH PLAINS NEWD ACROSS SRN KS INTO PARTS OF MO...THEN SWD ALONG THE DRYLINE INTO OK. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL BE POSSIBLE...MAINLY ACROSS PARTS OF ERN OK...THOUGH THE SELY LOW-LEVEL FLOW MAY BE RATHER WEAK. FARTHER S...TSTMS WILL LIKELY BE MORE ISOLD ALONG THE DRYLINE INTO CNTRL TX. CINH IS EXPECTED TO BE RATHER STRONG AND THE UPPER FLOW REGIME SOMEWHAT ANTICYLONIC DURING MOST OF THE PEAK HEATING HOURS. BUT...THE BOUNDARY LAYER SHOULD BECOME RATHER HOT AND COULD ALLOW PARCELS TO BREECH THE CAP. SUPERCELLS WILL BE POSSIBLE AND A CONDITIONAL SLGT RISK WILL EXIST ALONG THE DRYLINE. SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY DOWNSTREAM FROM THE OZARKS INTO THE LWR MS VLY AND UPSTREAM FROM THE SRN HIGH PLAINS INTO OK/N TX. THESE STORMS MAY HAVE A NOCTURNAL THREAT FOR HAIL/HIGH WINDS. LASTLY...A WEAKER MCS MAY EVOLVE FROM PARTS OF ERN WY/CO INTO WRN NEB. ISOLD HAIL MAY OCCUR WITH THE STRONGER STORMS...MAINLY ACROSS CO. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING WITH RESPECT TO THE WARM SECTOR ORIENTATION...EVOLUTION INTO LINE SEGMENTS IS LIKELY EARLY IN THE TSTM LIFE CYCLES. ISOLD DAMAGING WINDS/HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT THE SEVERE THREAT SHOULD WANE DURING THE EVENING HOURS. ..RACY.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 17:54:45 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 13:54:45 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081752 SWODY2 SPC AC 081751 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 PM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND ACROSS THE LOWER MS VALLEY... ...SYNOPSIS... AN ACTIVE SEVERE WEATHER PATTERN APPEARS TO BE SETTING UP FOR TUESDAY. DETAILS WITH REGARD TO WHERE GREATEST SEVERE POTENTIAL WILL EVOLVE ARE NOT YET CLEAR. HOWEVER...CHANCES FOR SEVERE STORMS SHOULD INCREASE FROM THE TX/OK PNHDLS EWD ACROSS THE OZARKS DURING THE DAY AND EVENING TUESDAY. A NRN BRANCH MID/UPPER LEVEL TROUGH WILL UNDERGO AMPLIFICATION ACROSS THE NRN AND CNTRL PLAINS THROUGH TUESDAY AS A NUMBER OF SMALLER SCALE PERTURBATIONS ROTATE THROUGH THE LARGE SCALE CYCLONIC FLOW FROM THE ROCKIES TO THE MS VALLEY. AT THE SURFACE...VARIOUS MCS OUTFLOW BOUNDARIES WILL BE INTERSPERSED WITH SYNOPTIC FRONTAL ZONES FROM THE SRN PLAINS/OZARKS NWD TO THE UPPER MS VALLEY. LATEST MODEL GUIDANCE WAS IN RELATIVELY GOOD AGREEMENT THAT ONE MCS WILL BE LOCATED OVER THE OZARKS EARLY TUESDAY WITHIN WARM CONVEYOR BELT AHEAD OF LEE-TROUGH AND SRN PLAINS COLD FRONT. ANOTHER MCS MAY BE ONGOING EARLY IN THE PERIOD ACROSS MN/WI NEAR A MID LEVEL SHORT WAVE TROUGH BEING EJECTED EWD AHEAD OF NEXT STRONG UPSTREAM SYSTEM DEVELOPING EAST FROM THE ROCKIES/HIGH PLAINS. SYNOPTIC FRONTS WILL ALSO INCLUDE A WARM FRONT EXTENDING FROM THE MCS OVER ERN OK/OZARKS SEWD TO THE DEEP SOUTH...AND A SECONDARY COLD FRONT ASSOCIATED WITH THE NRN BRANCH SYSTEM DEVELOPING SEWD ACROSS THE NRN/CNTRL PLAINS. LARGE SCALE HEIGHT FALLS AND DIFFERENTIAL HEATING WILL REINFORCE THE SRN PLAINS COLD FRONT FROM SERN CO TO THE NRN TX PNHDL AND INTO NWRN OK BY LATE AFTERNOON. MEANWHILE...DRYLINE WILL SHARPEN OVER THE ERN TX PNHDL AS TRIPLE POINT LOW EVOLVES ACROSS NWRN TX/SWRN OK. STRENGTHENING MESOSCALE FORCING ASSOCIATED WITH THESE FEATURES...COUPLED WITH INCREASING INSTABILITY AND SHEAR...SHOULD PROMOTE WIDESPREAD SEVERE TSTM ACTIVITY FROM THE SRN PLAINS TO THE LOWER MS VALLEY THROUGH TUESDAY NIGHT. ...SRN PLAINS/OZARKS EAST ACROSS THE LOWER MS VALLEY... MCS EVOLUTION ACROSS THE PLAINS THROUGH TUESDAY MORNING WILL PLAY A SIGNIFICANT ROLE IN SEVERE WEATHER FORMATION AND STORM MODE ACROSS PARTS OF OK AND AR LATER TUESDAY AFTERNOON. GIVEN THAT THE MCS HAS YET TO FORM...AND CONVECTIVE INHIBITION ACROSS THE WARM SECTOR MAY BE QUITE STRONG WITH 700MB TEMPERATURES AROUND 10C...A LOWER CONFIDENCE FORECAST SUGGESTS MAINTAINING ONLY A SLGT RISK AT THIS TIME. LATEST GUIDANCE DOES SUGGEST THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. OUTFLOW BOUNDARY SHOULD REINFORCE THE WARM FRONT ACROSS SRN OK SEWD ACROSS SRN AR. DESTABILIZATION AHEAD OF THE MCS...AND ALONG THE WARM FRONT TO THE TN VALLEY...COULD RESULT IN STRONG TO SEVERE STORMS CONTINUING... OR REDEVELOPING...EWD ACROSS THESE AREAS THROUGH THE DAY. DAMAGING WINDS...SOME HAIL...AND PERHAPS EVEN A TORNADO OR TWO COULD OCCUR WITH THIS ACTIVITY. THE SWRN FLANK OF THE MCS WILL PROBABLY WEAKEN AS CONVECTIVE INHIBITION STRENGTHENS ACROSS THE WARM SECTOR. HOWEVER...STRONG SWLY LLJ WILL CONTINUE TO TRANSPORT VERY UNSTABLE PARCELS ACROSS THE COLD POOL...AND CONVECTIVE CLUSTER WITH SOME HAIL POTENTIAL MAY PERSIST ACROSS PARTS OF AR DURING THE MORNING. SUBSIDENCE AND CAPPING IN WAKE OF THE MCS WILL ALLOW FOR THE DEVELOPMENT OF STRONG DESTABILIZATION ACROSS TX/OK THROUGH THE DAY WITH GREATEST CHANCE FOR STORM INITIATION OCCURRING BY AFTERNOON ALONG/NORTH OF REMNANT OUTFLOW...ACROSS WRN AR TO NRN OK. A SECONDARY AREA FOR STORM DEVELOPMENT SHOULD EVOLVE NEAR THE COLD FRONT/DRYLINE TRIPLE POINT...OR NORTH OF THESE FEATURES WHERE INCREASING LARGE SCALE FORCING FROM AMPLIFYING FLOW/HEIGHT FALLS WILL OVERCOME INHIBITION. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...MAINLY ACROSS PARTS OF NRN/ERN OK AND PERHAPS WRN AR...WHERE POST-OUTFLOW/FRONT ELY FLOW WILL RESULT IN ENLARGED HODOGRAPHS. FARTHER SOUTH ALONG ADVANCING DRYLINE...TSTMS WILL LIKELY BE MORE ISOLATED GIVEN STRONG CAP AND WEAKER LARGE SCALE FORCING. EXPECT SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY FROM THE OZARKS INTO THE LWR MS VLY...AND FROM THE SRN HIGH PLAINS ACROSS OK AND NRN TX. GIVEN AVAILABLE INSTABILITY FEEDING INTO THESE STORMS...THREAT FOR HAIL/HIGH WINDS MAY PERSIST WELL AFTER DARK AND INTO EARLY WEDNESDAY. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS IN THE 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING...EVOLUTION INTO LINE SEGMENTS IS LIKELY. A COUPLE OF DAMAGING WIND/HAIL EVENTS MAY ACCOMPANY THE STRONGER STORMS. EXPECT SEVERE THREAT TO WANE DURING THE EVENING HOURS. ..CARBIN.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 20:31:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 16:31:12 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 082027 SWODY2 SPC AC 082026 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0326 PM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND ACROSS THE LOWER MS VALLEY... CORRECTED FOR NDFD PROBS ...SYNOPSIS... AN ACTIVE SEVERE WEATHER PATTERN APPEARS TO BE SETTING UP FOR TUESDAY. DETAILS WITH REGARD TO WHERE GREATEST SEVERE POTENTIAL WILL EVOLVE ARE NOT YET CLEAR. HOWEVER...CHANCES FOR SEVERE STORMS SHOULD INCREASE FROM THE TX/OK PNHDLS EWD ACROSS THE OZARKS DURING THE DAY AND EVENING TUESDAY. A NRN BRANCH MID/UPPER LEVEL TROUGH WILL UNDERGO AMPLIFICATION ACROSS THE NRN AND CNTRL PLAINS THROUGH TUESDAY AS A NUMBER OF SMALLER SCALE PERTURBATIONS ROTATE THROUGH THE LARGE SCALE CYCLONIC FLOW FROM THE ROCKIES TO THE MS VALLEY. AT THE SURFACE...VARIOUS MCS OUTFLOW BOUNDARIES WILL BE INTERSPERSED WITH SYNOPTIC FRONTAL ZONES FROM THE SRN PLAINS/OZARKS NWD TO THE UPPER MS VALLEY. LATEST MODEL GUIDANCE WAS IN RELATIVELY GOOD AGREEMENT THAT ONE MCS WILL BE LOCATED OVER THE OZARKS EARLY TUESDAY WITHIN WARM CONVEYOR BELT AHEAD OF LEE-TROUGH AND SRN PLAINS COLD FRONT. ANOTHER MCS MAY BE ONGOING EARLY IN THE PERIOD ACROSS MN/WI NEAR A MID LEVEL SHORT WAVE TROUGH BEING EJECTED EWD AHEAD OF NEXT STRONG UPSTREAM SYSTEM DEVELOPING EAST FROM THE ROCKIES/HIGH PLAINS. SYNOPTIC FRONTS WILL ALSO INCLUDE A WARM FRONT EXTENDING FROM THE MCS OVER ERN OK/OZARKS SEWD TO THE DEEP SOUTH...AND A SECONDARY COLD FRONT ASSOCIATED WITH THE NRN BRANCH SYSTEM DEVELOPING SEWD ACROSS THE NRN/CNTRL PLAINS. LARGE SCALE HEIGHT FALLS AND DIFFERENTIAL HEATING WILL REINFORCE THE SRN PLAINS COLD FRONT FROM SERN CO TO THE NRN TX PNHDL AND INTO NWRN OK BY LATE AFTERNOON. MEANWHILE...DRYLINE WILL SHARPEN OVER THE ERN TX PNHDL AS TRIPLE POINT LOW EVOLVES ACROSS NWRN TX/SWRN OK. STRENGTHENING MESOSCALE FORCING ASSOCIATED WITH THESE FEATURES...COUPLED WITH INCREASING INSTABILITY AND SHEAR...SHOULD PROMOTE WIDESPREAD SEVERE TSTM ACTIVITY FROM THE SRN PLAINS TO THE LOWER MS VALLEY THROUGH TUESDAY NIGHT. ...SRN PLAINS/OZARKS EAST ACROSS THE LOWER MS VALLEY... MCS EVOLUTION ACROSS THE PLAINS THROUGH TUESDAY MORNING WILL PLAY A SIGNIFICANT ROLE IN SEVERE WEATHER FORMATION AND STORM MODE ACROSS PARTS OF OK AND AR LATER TUESDAY AFTERNOON. GIVEN THAT THE MCS HAS YET TO FORM...AND CONVECTIVE INHIBITION ACROSS THE WARM SECTOR MAY BE QUITE STRONG WITH 700MB TEMPERATURES AROUND 10C...A LOWER CONFIDENCE FORECAST SUGGESTS MAINTAINING ONLY A SLGT RISK AT THIS TIME. LATEST GUIDANCE DOES SUGGEST THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. OUTFLOW BOUNDARY SHOULD REINFORCE THE WARM FRONT ACROSS SRN OK SEWD ACROSS SRN AR. DESTABILIZATION AHEAD OF THE MCS...AND ALONG THE WARM FRONT TO THE TN VALLEY...COULD RESULT IN STRONG TO SEVERE STORMS CONTINUING... OR REDEVELOPING...EWD ACROSS THESE AREAS THROUGH THE DAY. DAMAGING WINDS...SOME HAIL...AND PERHAPS EVEN A TORNADO OR TWO COULD OCCUR WITH THIS ACTIVITY. THE SWRN FLANK OF THE MCS WILL PROBABLY WEAKEN AS CONVECTIVE INHIBITION STRENGTHENS ACROSS THE WARM SECTOR. HOWEVER...STRONG SWLY LLJ WILL CONTINUE TO TRANSPORT VERY UNSTABLE PARCELS ACROSS THE COLD POOL...AND CONVECTIVE CLUSTER WITH SOME HAIL POTENTIAL MAY PERSIST ACROSS PARTS OF AR DURING THE MORNING. SUBSIDENCE AND CAPPING IN WAKE OF THE MCS WILL ALLOW FOR THE DEVELOPMENT OF STRONG DESTABILIZATION ACROSS TX/OK THROUGH THE DAY WITH GREATEST CHANCE FOR STORM INITIATION OCCURRING BY AFTERNOON ALONG/NORTH OF REMNANT OUTFLOW...ACROSS WRN AR TO NRN OK. A SECONDARY AREA FOR STORM DEVELOPMENT SHOULD EVOLVE NEAR THE COLD FRONT/DRYLINE TRIPLE POINT...OR NORTH OF THESE FEATURES WHERE INCREASING LARGE SCALE FORCING FROM AMPLIFYING FLOW/HEIGHT FALLS WILL OVERCOME INHIBITION. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...MAINLY ACROSS PARTS OF NRN/ERN OK AND PERHAPS WRN AR...WHERE POST-OUTFLOW/FRONT ELY FLOW WILL RESULT IN ENLARGED HODOGRAPHS. FARTHER SOUTH ALONG ADVANCING DRYLINE...TSTMS WILL LIKELY BE MORE ISOLATED GIVEN STRONG CAP AND WEAKER LARGE SCALE FORCING. EXPECT SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY FROM THE OZARKS INTO THE LWR MS VLY...AND FROM THE SRN HIGH PLAINS ACROSS OK AND NRN TX. GIVEN AVAILABLE INSTABILITY FEEDING INTO THESE STORMS...THREAT FOR HAIL/HIGH WINDS MAY PERSIST WELL AFTER DARK AND INTO EARLY WEDNESDAY. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS IN THE 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING...EVOLUTION INTO LINE SEGMENTS IS LIKELY. A COUPLE OF DAMAGING WIND/HAIL EVENTS MAY ACCOMPANY THE STRONGER STORMS. EXPECT SEVERE THREAT TO WANE DURING THE EVENING HOURS. ..CARBIN.. 05/08/2006  From swody2 at goshenarc.org Tue May 9 17:48:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 09 May 2006 13:48:29 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091745 SWODY2 SPC AC 091744 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 PM CDT TUE MAY 09 2006 VALID 101200Z - 111200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM THE CONFLUENCE OF THE OH/MS RIVERS SWD ACROSS THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM SERN TX TO LOWER MI TO GA AND NRN FL... ...WIDESPREAD AND POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE APPEARS INCREASINGLY LIKELY OVER PARTS OF THE MS/TN VALLEYS AND LOWER OH VALLEY DURING WEDNESDAY... ...SYNOPSIS... MID/UPPER LEVEL FLOW OVER THE CNTRL U.S. WILL CONTINUE TO UNDERGO STRONG AMPLIFICATION THROUGH MIDWEEK AS LARGE SCALE PHASING BETWEEN MIDDLE AND NRN BRANCH FLOW PRODUCES AN ANOMALOUSLY DEEP CYCLONE ACROSS THE MIDWEST. THIS LARGE SCALE EVOLUTION WILL UNFOLD AS STRONG MIDDLE STREAM SHORT WAVE TROUGH DEVELOPS EAST ACROSS THE SRN PLAINS THROUGH LATE TUESDAY EVENING. THIS IMPULSE IS EXPECTED TO INDUCE STRONG MCS DEVELOPMENT ACROSS OK THROUGH TUESDAY NIGHT. SRN PLAINS SURFACE LOW IS FORECAST TO STRENGTHEN COINCIDENT WITH THE MCS AND SPREAD EAST TO NEAR THE MO BOOTHEEL AREA BY WEDNESDAY MORNING. SLOWER MOVING NRN BRANCH SHORT WAVE TROUGH/LOW WILL DEVELOP ESEWD FROM MT TOWARD THE UPPER MS VALLEY THROUGH WEDNESDAY AFTERNOON. STRONG COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SPREAD QUICKLY SWD/SEWD ACROSS THE PLAINS AND MERGE WITH THE DEEPENING CYCLONE ACROSS THE LOWER OH VALLEY DURING WEDNESDAY AFTERNOON. WHILE PRIMARY DEEP LAYER CYCLONE ASSOCIATED WITH THE NRN BRANCH TROUGH UNDERGOES OCCLUSION OVER LAKE MI...INTENSIFYING SECONDARY CYCLONE IS FORECAST TO TRACK NNEWD ACROSS THE MIDWEST... AND INTO LOWER MI...THROUGH WEDNESDAY EVENING. TRAILING COLD FRONT WILL SWEEP EWD ACROSS THE MID/LOWER MS VALLEY...AND ACROSS MUCH OF THE DEEP SOUTH AND OFF THE NCNTRL GULF COAST...THROUGH EARLY THURSDAY. ...SERN MO TO LOWER MI... POTENTIAL EXISTS FOR WIDESPREAD CLOUDS AND PRECIPITATION TO SOMEWHAT IMPEDE AIR MASS MODIFICATION ACROSS THE LOWER OH VALLEY DURING WEDNESDAY GIVEN PRESENCE OF UPSTREAM MCS ACTIVITY AND STRONG OUTFLOW BOUNDARIES. HOWEVER...GFS AND ENSEMBLE FORECASTS SUPPORT AT LEAST MODEST RECOVERY IN THE WAKE OF MORNING CONVECTION AND AHEAD OF APPROACHING MID LEVEL WIND MAX AND DEEPENING SURFACE LOW. GIVEN LOW TO MID 60S SURFACE DEWPOINTS AND POCKETS OF MLCAPE AROUND 500 J/KG /POSSIBLY HIGHER IF GFS FORECAST VERIFIES/ SHEAR AND FORCING APPEAR MORE THAN ADEQUATE TO PROMOTE STORM ORGANIZATION INTO LINE SEGMENTS AND LOW TOPPED SUPERCELLS. THIS ACTIVITY SHOULD SPREAD ENEWD ACROSS THE LOWER OH VALLEY AND LOWER MI FROM AFTERNOON THROUGH EVENING WITH AN INCREASING CHANCE FOR HAIL AND HIGH WINDS. TORNADO POTENTIAL APPEARS GREATEST NEAR THE INTENSIFYING SURFACE LOW. IF MODEST TO STRONG INSTABILITY CAN DEVELOP COINCIDENT WITH THIS FEATURE...A COUPLE OF STRONG TORNADOES APPEAR POSSIBLE. ...LOWER MS VALLEY/TN VALLEY/DEEP SOUTH... SOUTH OF THE SURFACE LOW...WIDESPREAD MOISTURE AND INCREASING INSTABILITY SHOULD EXIST. OUTFLOW FROM POSSIBLE OK/AR MCS MAY SPREAD SEWD INTO AND INHIBIT STRONGER AIR MASS DESTABILIZATION EARLY IN THE DAY. HOWEVER...STRONG RECOVERY IS EXPECTED IN THE WAKE OF THIS OUTFLOW...FROM TXK ACROSS THE LOWER MS VALLEY BY AFTERNOON. DIFFLUENT AND INCREASINGLY STRONG WLY MID LEVEL FLOW WILL SPREAD ACROSS THE RECOVERING WARM SECTOR AND FOSTER NEW CONVECTION AHEAD OF THE COLD FRONT FROM AR ACROSS THE MS RIVER. THIS ACTIVITY WILL EXIST WITHIN A STRONGLY SHEARED ENVIRONMENT AND NUMEROUS SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS APPEAR POSSIBLE. IF THIS CONVECTION CAN REMAIN DISCRETE THROUGH LATE AFTERNOON...STORMS WILL MOVE INTO HIGH HELICITY REGIME EXISTING IN THE WAKE OF EARLIER MCS OUTFLOW. TORNADIC STORMS APPEAR POSSIBLE BEFORE CONVECTION BECOMES INCREASINGLY LINEAR AS INTENSIFYING COLD FRONT DEVELOPS INTO THE REGION. WIND DAMAGE AND ISOLATED TORNADO THREAT MAY EXTEND BEYOND SUNSET AS SEVERE SQUALL LINE DEVELOPS ESEWD ACROSS THE NRN GULF COAST/DEEP SOUTH. ..CARBIN.. 05/09/2006  From swody2 at goshenarc.org Wed May 10 05:59:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 10 May 2006 01:59:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100556 SWODY2 SPC AC 100555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT WED MAY 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SERN VA INTO THE ERN CAROLINAS... ...SYNOPSIS... DEEP UPPER LOW IS EXPECTED TO EVOLVE OVER THE MIDWEST/GRTLKS REGION BY WED...THEN REMAIN IN PLACE INTO THU. A POTENT SHORTWAVE TROUGH...NOW DIGGING ACROSS THE NRN ROCKIES...WILL AMPLIFY AS IT ROTATES ALONG THE SRN PERIPHERY OF THE SYSTEM AND INTO THE SERN STATES THU AFTN. AT THE SFC...A LOW WILL MEANDER ACROSS NRN IND/SRN LWR MI ON THU WITH THE ATTENDANT COLD FRONT SWEEPING EWD TOWARD THE ATLANTIC SEABOARD. A SECONDARY LOW IS EXPECTED TO FORM IN THE SRN APPALACHIANS AND MOVE NEWD TOWARD NRN VA BY THU EVE WHILE A WARM FRONT LIFTS NWD TOWARD THE MASON-DIXON LINE. ...MID-ATLANTIC/ERN CAROLINAS... IT APPEARS THAT EARLY DAY CLOUDS/CONVECTION WITHIN A WARM CONVEYOR SHOULD MOVE OFF THE COAST BY MID-DAY THU...LEAVING MUCH OF THE SRN APPALACHIANS WITH THE POTENTIAL TO HEAT. SLY LOW-LEVEL FLOW SHOULD ADVECT LOWER-MID 60S SFC DEW POINTS NWD THROUGH THE COASTAL PLAINS OF THE CAROLINAS INTO SCNTRL/SERN VA. LAPSE RATES WILL TEND TO BE WEAK OWING TO RELATIVELY WARM TEMPERATURES IN THE H5-H7 LAYER. LATER IN THE AFTN...HOWEVER...STEEPER LAPSE RATES ALOFT SHOULD SPREAD ATOP THE MOIST AXIS AND GIVEN APPROACH OF 120 METER HEIGHT FALLS AND A 70-80 KT H5 JET AXIS...ENVIRONMENT COULD BECOME FAVORABLE FOR TSTMS TO DEVELOP VCNTY THE MOUNTAINS/FOOTHILLS BY MID-LATE AFTN. TSTMS WILL THEN MOVE NEWD ACROSS THE COASTAL PLAINS OF SERN VA AND THE ERN CAROLINAS BY EVENING. VERTICAL SHEAR OF 40-50 KTS WILL BE SUFFICIENT FOR ORGANIZED STORMS WITH HAIL...DAMAGING WINDS AND A TORNADO OR TWO. FARTHER S...LOW-LEVEL CONVERGENCE ALONG THE TRAILING FRONT BECOMES WEAK THROUGH THE AFTN. ISOLD TSTMS WILL BE POSSIBLE THE LENGTH OF THE FRONT INTO NRN/CNTRL FL AND DAMAGING WINDS MAY OCCUR. ...MIDWEST... MUCH UNCERTAINTY EXISTS WITH RESPECT TO THE MAGNITUDE OF CLOUD COVER BENEATH THE UPPER LOW. COLD POOL ALOFT /H5 TEMP AOA MINUS 20 DEG C/ WILL SHIFT EWD ACROSS THE MIDWEST ATOP MID-UPPER 40S SFC DEW POINTS. IF A ZONE OF STRONGER HEATING CAN OCCUR WITHIN ERN HALF OF THE UPPER LOW...A STRONGER STORM OR TWO MAY PRODUCE DAMAGING WINDS OR HAIL. ..RACY.. 05/10/2006  From swody2 at goshenarc.org Wed May 10 17:21:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 10 May 2006 13:21:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101718 SWODY2 SPC AC 101717 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 PM CDT WED MAY 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID ATLANTIC... ...SYNOPSIS... STRONG DEEP-LAYER CYCLONE WILL CONTINUE TO EVOLVE OVER THE UPPER MIDWEST/GREAT LAKES REGIONS THROUGH THURSDAY...AND THEN REMAIN ANCHORED OVER THESE AREAS AS A DEEP CLOSED LOW THROUGH THE END OF THE WEEK. THIS PROCESS WAS ALREADY UNDERWAY AS A VIGOROUS SHORT WAVE TROUGH...CURRENTLY CROSSING THE SRN PLAINS...PIVOTS RAPIDLY NEWD ACROSS THE MID MS VALLEY AND INDUCES STRONG CYCLOGENESIS OVER THE MIDWEST AND LOWER MI LATE TODAY THROUGH THURSDAY MORNING. ANOTHER POTENT UPSTREAM VORTICITY MAXIMUM...EVIDENT IN WATER VAPOR IMAGERY DIGGING SEWD ACROSS THE CNTRL PLAINS...WILL ROTATE THROUGH THE BASE OF THE LARGE SCALE LOW AND THEN ACROSS THE TN VALLEY ON THURSDAY AFTERNOON. STRONG HEIGHT FALLS ASSOCIATED WITH THIS SECONDARY SHORT WAVE FEATURE WILL SPREAD EWD/SEWD ACROSS THE SOUTHEAST...APPALACHIANS...AND MID ATLANTIC COASTAL PLAIN FROM THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. AS PRIMARY SURFACE CYCLONE UNDERGOES OCCLUSION OVER LOWER MI DURING THE DAY...ASSOCIATED COLD FRONT WILL SWEEP EAST ACROSS THE APPALACHIANS. GIVEN STRONG DYNAMIC FORCING ASSOCIATED WITH THE SECOND SHORT WAVE TROUGH APPROACHING THE APPALACHIANS...WEAK SECONDARY CYCLOGENESIS IS LIKELY TO OCCUR ON THE ADVANCING COLD FRONT IN THE LEE OF THE APPALACHIANS. THIS WAVE AND THE FRONT WILL THEN DEVELOP ENEWD ACROSS NRN VA THROUGH THE EVENING AS THE TRAILING PORTION OF THE COLD FRONT MOVES EWD AND OFF THE EAST COAST BY EARLY FRIDAY. ...MID-ATLANTIC/ERN CAROLINAS... WIDESPREAD CLOUDS AND CONVECTION ARE EXPECTED AT THE START OF THE PERIOD WITHIN EXTENSIVE WARM CONVEYOR BELT WHICH SHOULD MOVE EAST AND OFF THE COAST BY AFTERNOON. AT LEAST MODEST SURFACE HEATING SHOULD DEVELOP IN THE WAKE OF MORNING RAIN/CLOUDS BENEATH MID-LEVEL DRY SLOT FORECAST TO WRAP AROUND THE LARGER SCALE LOW FROM THE SRN APPALACHIANS TO WV/SWRN VA. WHILE MID LEVEL LAPSE RATES WITHIN THE DRY SLOT WILL TEND TO BE WEAK GIVEN RELATIVELY WARM TEMPERATURES IN THE H5-H7 LAYER...SURFACE HEATING AND DEWPOINTS IN THE 60S SHOULD CONTRIBUTE TO WEAK TO MODEST DESTABILIZATION AHEAD OF THE COLD FRONT. MIXING AND ASCENT ALONG THE FRONT SHOULD BE ENHANCED AS STRONG HEIGHT FALLS SPREAD EAST ATOP THE MOIST AXIS THROUGH THE LATE AFTERNOON. THIS SHOULD PROMOTE THE DEVELOPMENT OF A RELATIVELY LOW-TOPPED SQUALL LINE FROM SRN PA/NRN VA AREA SWD ACROSS PARTS OF THE CAROLINAS. DEEP LAYER VERTICAL SHEAR WILL STRENGTHEN COINCIDENT WITH THE DEVELOPING LINE OF STORMS AND SHOULD PROVE SUFFICIENT FOR STORM ORGANIZATION AND SUSTENANCE. SUPERCELLS AND LINE SEGMENTS SHOULD EVOLVE FROM THE FORCED LINE OF CONVECTION AND RESULT IN SCATTERED HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO OR TWO. FARTHER S...LOW-LEVEL CONVERGENCE AND DEEP SHEAR ALONG THE TRAILING FRONT BECOME WEAKER...FROM SRN SC SWD ACROSS FL. HOWEVER...FRONTAL CIRCULATION WILL MOVE INTO A VERY MOIST AND WEAKLY CAPPED ENVIRONMENT AND A FEW TSTMS ALONG THE LENGTH OF THE FRONT COULD PRODUCE ISOLATED DAMAGING WINDS AND/OR MARGINALLY SEVERE HAIL. ...SERN MO ACROSS THE TN VALLEY... MID LEVEL COLD POOL AND MODEST DYNAMIC FORCING ON CYCLONIC SHEAR SIDE OF MID LEVEL WIND MAX WILL FOSTER LOW-TOPPED CONVECTIVE DEVELOPMENT FROM THE MID MS VALLEY ESEWD ACROSS PARTS OF KY/TN DURING THE AFTERNOON. DESPITE LIMITED BOUNDARY LAYER MOISTURE IN THESE AREAS IN THE WAKE OF STRONG FRONTAL PASSAGE...SURFACE HEATING BENEATH COLD MID LEVEL TEMPERATURES AOB -20C WILL SUPPORT WEAK MLCAPE AND STEEP LOW THROUGH MID LEVEL LAPSE RATES. A FEW TSTM CLUSTERS FORMING WITHIN THIS REGION MAY PRODUCE HAIL. A SMALL SLGT RISK COULD BE INTRODUCED IN LATER OUTLOOKS IF IT APPEARS THAT HAIL STORM COVERAGE WARRANTS HIGHER PROBABILITIES. ..CARBIN.. 05/10/2006  From swody2 at goshenarc.org Fri May 12 06:05:32 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 May 2006 02:05:32 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120602 SWODY2 SPC AC 120601 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT FRI MAY 12 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER PATTERN TO REMAIN GENERALLY UNCHANGED THIS PERIOD...AS LARGE LOW/TROUGH REMAINS OVER THE ERN HALF OF THE CONUS...WHILE RIDGE PREVAILS ACROSS THE ROCKIES. AT THE SURFACE...HIGH PRESSURE OVER THE GULF OF MEXICO IS FORECAST TO WEAKEN WITH TIME...AS COLD FRONT MOVES SEWD ACROSS THE SRN PLAINS/SERN CONUS. ...SRN PLAINS EWD ACROSS THE SOUTHEAST... DIFFICULT FORECAST THIS PERIOD...WITH MODEL VARIABILITY LARGE ACROSS THE S CENTRAL AND SERN CONUS. ON THE LARGE SCALE...COLD FRONT WILL MOVE SWD/SEWD ACROSS THE REGION...THOUGH PREVIOUS FRONTAL PASSAGE INTO THE GULF SHOULD AFFECT THE QUALITY OF THE MOISTURE RETURN AHEAD OF THE SECOND FRONT -- PARTICULARLY ACROSS THE CENTRAL AND ERN GULF COAST REGION. THUS -- DESPITE MODEL FORECASTS OF A SHORT-WAVE TROUGH MOVING ACROSS THE SERN CONUS WITHIN FAST NWLY FLOW ALOFT...QUALITY OF AIRMASS REMAINS VERY QUESTIONABLE. LESS MODIFIED/MORE MOIST BOUNDARY LAYER AIRMASS WILL LIKELY RETURN ACROSS TX AND LA...BUT COMBINATION OF STRONGER CAP AND WEAKER FORCING LEAVES QUESTIONS REGARDING CONVECTIVE INITIATION ACROSS THIS REGION. SHOULD CAP WEAKEN ACROSS PARTS OF THE SRN PLAINS NEAR FRONT...AND SHOULD QUALITY OF MOISTURE RETURN INTO THE GULF COAST REGION RESULT IN SUFFICIENT INSTABILITY...A LARGE AREA OF SEVERE WEATHER COULD RESULT. ON THE OTHER HAND...SHOULD CAP REMAIN STRONG OVER TX AND MOISTURE RETURN LIMITED ACROSS THE GULF COAST REGION...LITTLE IF ANY SEVERE WEATHER MAY OCCUR. WITH THESE QUESTIONS...AND VERY SIGNIFICANT MODEL DIFFERENCES REGARDING TIMING/LOCATION OF SEWD-MOVING FRONT...WILL MAINTAIN ONLY 5% SEVERE PROBABILITY ACROSS THE S CENTRAL AND SERN CONUS ATTM. ..GOSS.. 05/12/2006  From swody2 at goshenarc.org Fri May 12 17:37:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 May 2006 13:37:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121734 SWODY2 SPC AC 121733 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 PM CDT FRI MAY 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL GULF COAST STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN TX/SRN AR/LA... ...SYNOPSIS... BLOCKING PATTERN WILL PERSIST INTO THE DAY 2 PERIOD AS LARGE CLOSED UPPER LOW...NOW CENTERED OVER THE WRN GREAT LAKES...SETTLES SWD ACROSS THE OH VALLEY...AND THE UPSTREAM RIDGE BUILDS NWD OVER THE WRN STATES/SWRN CANADA. A COUPLE OF WEAK SHORT WAVE TROUGHS WITHIN STRONG NWLY FLOW REGIME ALONG WRN/SRN PERIPHERIES OF UPPER CYCLONE WILL AID IN THUNDERSTORMS ACROSS THE CENTRAL GULF COAST STATES...AND THEN LATE IN THE PERIOD OVER SERN PLAINS/LOWER MS VALLEY. AT THE SURFACE...A WEAK BOUNDARY EXTENDING FROM THE TX PANHANDLE ESE THROUGH RED RIVER/LOWER MS VALLEYS TO FL PANHANDLE IS EXPECTED TO REMAIN NEARLY STATIONARY SATURDAY. THIS BOUNDARY SHOULD THEN MOVE SWD SATURDAY NIGHT AS COLD FRONT MOVES SWD INTO THE SRN PLAINS AND THROUGH TN VALLEY TO GULF COAST STATES. ...GULF COAST STATES... MOISTURE RETURN BY DAY 2 ACROSS THE GULF COAST STATES IS EXPECTED TO BE SUFFICIENT /SURFACE DEWPOINTS IN THE UPPER 50S TO AROUND 60/ FOR A THREAT OF SEVERE STORMS...GIVEN AN ELEVATED MIXED LAYER/STEEP LAPSE RATE ENVIRONMENT ADVECTING EWD ATOP THIS LOW-LEVEL MOISTENING. SATURDAY AFTERNOON MLCAPE VALUES SHOULD RANGE FROM 800-1200 J/KG. AT THE START OF THE PERIOD...ELEVATED THUNDERSTORMS MAY BE ONGOING ACROSS ERN OK INTO THE LOWER MS VALLEY. THIS ACTIVITY WILL BE ASSOCIATED WITH WAA ALONG THE NOSE OF A WSWLY ORIENTED LLJ. THIS WAA ACTIVITY WILL SPREAD EWD ACROSS THE GULF COAST STATES AS ASSOCIATED WEAK MID LEVEL IMPULSE TRACKS ESEWD ACROSS THE REGION. STORMS SHOULD BECOME SURFACE BASED BY SATURDAY AFTERNOON AS SURFACE HEATING WEAKENS THE CAP...WITH THE INSTABILITY AND STRONG DEEP LAYER SHEAR PER 50-70 KT WNWLY MID LEVEL JET SUPPORTING ORGANIZED STORMS/ SUPERCELLS. ...ERN TX/SRN AR/LA... STRONGER CAP FURTHER WEST ACROSS LA INTO TX IS EXPECTED TO PRECLUDE THUNDERSTORM DEVELOPMENT UNTIL SATURDAY EVENING ALONG/N OF STATIONARY BOUNDARY...AND APPROACHING COLD FRONT. INCREASING SWLY LLJ/WAA ACROSS ERN TX AND MOISTENING LOW LEVEL AIR MASS EXPECTED TO RESULT IN SUFFICIENT DESTABILIZATION FOR ELEVATED THUNDERSTORMS AS A SHORT WAVE TROUGH APPROACHES ERN TX/LOWER MS VALLEY SATURDAY NIGHT. MODERATE INSTABILITY AND STRONG EFFECTIVE BULK SHEAR VALUES EXPECTED TO SUPPORT POTENTIAL FOR ELEVATED SUPERCELLS...WITH ACTIVITY EVOLVING INTO AN MCS AND TRACKING SE ACROSS ERN TX/LA SATURDAY NIGHT. A CONDITIONAL THREAT FOR SEVERE AND LOWER SEVERE PROBABILITIES EXIST ACROSS W TX WHERE MODELS DIFFER ON THE DEVELOPMENT OF SURFACE BASED STORMS LATE SATURDAY AFTERNOON. IF ACTIVITY DEVELOPS...THEN INSTABILITY/SHEAR VALUES WOULD SUPPORT A FEW ORGANIZED STORMS WITH POTENTIAL FOR UPSCALE GROWTH INTO AN MCS SATURDAY EVENING. PARTS OF THIS REGION MAY REQUIRE AN UPGRADE IN SEVERE PROBABILITIES IN LATER OUTLOOKS. ..PETERS.. 05/12/2006  From swody2 at goshenarc.org Sat May 13 06:05:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 May 2006 02:05:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130603 SWODY2 SPC AC 130602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT SAT MAY 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CAROLINAS AND VICINITY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WRN TX/SERN NM... ...SYNOPSIS... LARGE-SCALE PATTERN -- FEATURING A RIDGE OVER THE WRN HALF OF THE CONUS AND A TROUGH/CLOSED LOW OVER THE EAST -- IS FORECAST TO UNDERGO SLIGHT AMPLIFICATION THIS PERIOD...BUT OTHERWISE REMAIN GENERALLY UNCHANGED. SURFACE FRONT -- INITIALLY FORECAST FROM THE ATLANTIC COAST STATES SWWD/WWD ACROSS THE GULF COAST STATES INTO TX...IS FORECAST TO MOVE EWD TOWARD THE ATLANTIC COAST/SWD TOWARD THE GULF COAST/SWWD INTO FAR W TX THROUGH THE PERIOD. THIS FRONT SHOULD SERVE AS A FOCUS FOR DEEP MOIST CONVECTION THROUGH THE PERIOD. ...THE CAROLINAS AND VICINITY... SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ALONG/AHEAD OF FRONT. CONVECTION SHOULD INCREASE/INTENSIFY DURING THE AFTERNOON AS DIURNAL HEATING -- LIKELY LIMITED BY ONGOING CLOUDS/PRECIPITATION -- RESULTS IN LIMITED AIRMASS DESTABILIZATION /AROUND 1000 J/KG MEAN-LAYER CAPE/. WITH MODERATELY-STRONG SWLY/WLY FLOW THROUGH A DEEP LAYER EXPECTED ACROSS THIS REGION/S OF UPPER TROUGH...EXPECT ORGANIZED STORMS -- POSSIBLY A SQUALL LINE -- TO EVOLVE. POTENTIAL FOR SEVERE CONVECTION WITH LOCALLY DAMAGING WINDS AND HAIL APPEARS HIGH ENOUGH ATTM TO WARRANT INTRODUCTION OF A SLIGHT RISK ACROSS THIS REGION. ...PARTS OF WRN TX/SERN NM... MODELS FORECAST ONGOING CONVECTION ALONG AND NEAR FRONT DURING THE START OF THE PERIOD...WHICH SHOULD WEAKEN AND THEN RE-INITIATE DURING THE AFTERNOON. THOUGH ISOLATED STRONG/SEVERE STORMS MAY OCCUR ACROSS THE GULF COAST REGION AND INTO TX...AREA OF SLIGHTLY GREATER SEVERE THREAT MAY EVOLVE ACROSS W TX. AS FRONT MOVES SWD/SWWD ACROSS TX...AREA OF ELY UPSLOPE FLOW SHOULD EVOLVE ACROSS THE TRANSPECOS REGION AND INTO SERN NM. WITH MODERATE WSWLY FLOW ALOFT FORECAST OVER THIS REGION...RESULTING DIRECTIONAL SHEAR MAY BE SUFFICIENT FOR ORGANIZED STORMS. ALONG WITH POTENTIAL FOR HAIL...DRY/DEEP BOUNDARY LAYER WOULD ALSO SUPPORT THREAT FOR DAMAGING WINDS. ..GOSS.. 05/13/2006  From swody2 at goshenarc.org Sat May 13 17:33:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 May 2006 13:33:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131731 SWODY2 SPC AC 131730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT SAT MAY 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC AND SOUTHEAST STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SWRN LA WWD THROUGH CENTRAL/SRN TX INTO SW TX/SERN NM... ...SYNOPSIS... LARGE CLOSED UPPER LOW ENCOMPASSING MUCH OF THE ERN TWO-THIRDS OF THE U.S. IS EXPECTED TO WEAKEN SOME ON SUNDAY AS THE CENTER TRACKS SLOWLY SEWD THROUGH THE OH VALLEY. STRONG BAND OF MID LEVEL WINDS /60-80 KT/ WILL EXTEND ALONG THE SWRN/SRN TO ERN PERIPHERY OF THIS LARGE UPPER CYCLONE...RESULTING IN A CONTINUATION OF STRONG DEEP LAYER SHEAR ACROSS THESE REGIONS. SERIES OF VORTICITY/JET MAXIMA WILL CONTINUE TO ROTATE THROUGH THE UPPER LOW. ONE SUCH SPEED MAX...NOW LOCATED NEAR MKC...IS EXPECTED TO TRANSLATE FROM THE TN VALLEY NEWD ACROSS GA/CAROLINAS TO THE DELMARVA REGION DURING DAY 2 PERIOD. AT THE SURFACE...LOW PRESSURE...ASSOCIATED WITH TN VALLEY SHORT WAVE TROUGH/SPEED MAX...SHOULD BE LOCATED OVER THE SRN APPALACHIANS AT 12Z SUNDAY. THIS LOW IS EXPECTED TO TRACK ENE REACHING CENTRAL/NERN NC BY SUNDAY EVENING...BEFORE TRACKING MORE NNE TOWARD THE DELMARVA REGION SUNDAY NIGHT. COLD FRONT WILL MOVE EWD ACROSS THE MID-ATLANTIC/SERN STATES. THE WWD TRAILING PORTION OF THIS BOUNDARY SHOULD MOVE SWD THROUGH CENTRAL GULF COAST STATES AND TX...REACHING THE GULF COAST AND SRN TX BY 12Z MONDAY. ...MID-ATLANTIC AND SOUTHEAST STATES... LOW-LEVEL MOISTURE /SURFACE DEWPOINTS UPPER 50S TO AROUND 60/ IS EXPECTED TO ADVECT NEWD FROM THE GULF COAST STATES AND ALSO NWD FROM THE ATLANTIC WATERS INTO GA TO VA IN ADVANCE OF THE APPROACHING SURFACE LOW AND TRAILING COLD FRONT. ALTHOUGH THUNDERSTORMS SHOULD BE ONGOING AT 12Z SUNDAY ACROSS PARTS OF THIS REGION...STRONG SURFACE HEATING IN THE WAKE OF INITIAL ACTIVITY COMBINED WITH MOISTURE RETURN WILL LIKELY RESULT IN MODERATE INSTABILITY BY SUNDAY AFTERNOON. NEW THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG SURFACE LOW/TRAILING COLD FRONT BY AFTERNOON AS TN VALLEY TROUGH MOVES ACROSS REGION. STRONG DEEP LAYER SHEAR IS EXPECTED TO SUPPORT MULTIPLE STORM MODES WITH BOTH SUPERCELLS AND LINEAR STRUCTURES POSSIBLE. SRN SEVERE THREAT ACROSS GA MAY MOVE INTO FAR NRN FL INCLUDING ERN FL PANHANDLE BY SUNDAY EVENING. ...SRN LA/CENTRAL-SRN TX TO SW TX/SERN NM... AT 12Z SUNDAY...ONGOING STRONG TO SEVERE THUNDERSTORM CLUSTER IS EXPECTED TO BE LOCATED ACROSS PARTS OF NERN TX EWD INTO NRN LA/MS. AIR MASS SOUTH OF THIS EARLY ACTIVITY FROM SRN LA INTO CENTRAL/SRN TX IS EXPECTED TO BECOME VERY UNSTABLE WITH SUNDAY AFTERNOON MLCAPE VALUES RANGING FROM 2000 J/KG IN SWRN LA TO 2500-3000 J/KG WWD INTO TX. GFS/NAMP SUGGEST A SERIES OF WEAK SRN STREAM IMPULSES WILL TRACK FROM THE FOUR CORNERS REGION SEWD ACROSS TX TO THE NWRN GULF... WITH LATEST WATER VAPOR IMAGERY INDICATING THESE IMPULSES FROM THE ERN PACIFIC TO THE FOUR CORNERS REGION. LARGE SCALE ASCENT WITH THESE FEATURES COMBINED WITH LOW LEVEL FORCING ALONG THE COLD FRONT IS EXPECTED TO SUPPORT ADDITIONAL THUNDERSTORMS FROM THE CENTRAL GULF COAST WWD INTO CENTRAL/SRN TX AS THE FRONT MOVES SWD. THE COMBINATION OF STRONG INSTABILITY/VERY STEEP LAPSE RATES AND STRONG DEEP LAYER SHEAR ARE EXPECTED TO SUPPORT ORGANIZED SEVERE STORMS FROM SWRN LA WWD INTO CENTRAL/SRN TX. THE SEVERE THREAT MAY PERSIST INTO THE OVERNIGHT PERIOD ACROSS SRN TX WHERE INSTABILITY/SHEAR VALUES WILL REMAIN SUFFICIENT. FURTHER W...THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE HIGHER TERRAIN OF THE CENTRAL/SRN ROCKIES INTO SWRN TX...WITH THE GREATEST POTENTIAL FOR A SEVERE THREAT ACROSS SW TX INTO SERN NM WHERE LOW LEVEL MOISTURE RETURN WILL BE STRONGEST. ELY LOW LEVEL UPSLOPE FLOW BENEATH MODERATE WLY MID LEVEL WINDS WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STORMS WITH HAIL/STRONG WIND GUSTS THE GREATEST THREATS GIVEN STEEP LAPSE RATES. ..PETERS.. 05/13/2006  From swody2 at goshenarc.org Sun May 14 05:21:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 May 2006 01:21:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140518 SWODY2 SPC AC 140517 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 AM CDT SUN MAY 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LITTLE CHANGE IN OVERALL UPPER PATTERN ANTICIPATED THIS PERIOD...AS UPPER LOW/TROUGH PERSISTS ACROSS THE ERN HALF OF THE CONUS AND A STRONG RIDGE PREVAILS OVER THE WEST. AT THE SURFACE...FRONT WILL CONTINUE PUSHING SWD ACROSS FL/THE GULF OF MEXICO/TX...AND WWD INTO THE ROCKIES. THIS BOUNDARY WILL SERVE AS A FOCUS FOR SCATTERED/GENERALLY SUB-SEVERE STORMS THROUGH THE PERIOD. ...FL PENINSULA... SCATTERED THUNDERSTORMS ARE ANTICIPATED ACROSS PARTS OF THE FL PENINSULA THIS PERIOD S OF WEAKENING/SWD-MOVING FRONT. THOUGH LOW-LEVEL CONVERGENCE SHOULD BE GENERALLY WEAK ALONG FRONT...LOCALLY GREATER CONVERGENCE -- PARTICULARLY INVOF SEA BREEZE BOUNDARIES -- SHOULD BE SUFFICIENT FOR STORM DEVELOPMENT WITHIN MODERATELY- UNSTABLE /1000 TO 200O J/KG MEAN-LAYER CAPE/ AFTERNOON AIRMASS. THOUGH AMPLE LOW- TO MID-LEVEL FLOW /40 TO 50 KT/ IS FORECAST ACROSS THIS AREA...ROUGHLY UNIDIRECTIONAL/WLY FLOW FIELD SHOULD LIMIT DEEP-LAYER SHEAR. NONETHELESS...SHEAR/INSTABILITY COMBINATION MAY SUPPORT A FEW STRONGER UPDRAFTS...CAPABLE OF PRODUCING BRIEF DAMAGING GUSTS OR MARGINAL HAIL. ..GOSS.. 05/14/2006  From swody2 at goshenarc.org Sun May 14 17:31:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 May 2006 13:31:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141728 SWODY2 SPC AC 141727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SUN MAY 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE LOCATED ACROSS ERN CANADA THAT HAS RESULTED IN LITTLE MOVEMENT OF LARGE ERN U.S. CLOSED LOW IS EXPECTED TO WEAKEN DURING THE DAY 1 PERIOD. FURTHER HEIGHT FALLS ACROSS ERN CANADA ON MONDAY WILL ALLOW FOR AN ENEWD MOVEMENT OF THE UPPER CYCLONE WITH THE CENTER MIGRATING SLOWLY TOWARD THE UPPER OH VALLEY/LOWER GREAT LAKES REGION. AT 12Z MONDAY...A COLD FRONT IS EXPECTED TO EXTEND FROM ERN PARTS OF THE MID-ATLANTIC REGION SWWD THROUGH SRN GA TO THE NRN GULF AND SRN TX...THEN NWWD INTO SRN ROCKIES. TX PORTION OF BOUNDARY WILL MOVE SWD INTO RIO GRANDE VALLEY/NRN MEXICO DURING PERIOD. ERN EXTENT OF FRONT /GA TO CAROLINAS/ EXPECTED TO HAVE GREATER S AND E MOVEMENT MONDAY NIGHT AS STRONGER HEIGHT FALLS DEVELOP ACROSS REGION WITH APPROACH OF SHORT WAVE TROUGH INTO LOWER MS VALLEY. ...FL PENINSULA... SRN GA/NRN FL WILL REMAIN WITHIN ENTRANCE REGION OF MID LEVEL SPEED MAX TRANSLATING THROUGH SERN-ERN PERIPHERY OF UPPER CYCLONE ON MONDAY. THIS WILL MAINTAIN FORCING FOR UPWARD VERTICAL MOTION ALONG THE COLD FRONT. THUS...THUNDERSTORMS WILL BE POSSIBLE ALONG THIS BOUNDARY...BUT OVERALL INTENSITY SHOULD BE LIMITED GIVEN GENERALLY WEAK LOW-LEVEL CONVERGENCE PER EXPECTED DEEP WLY FLOW ACROSS SERN STATES. ADDITIONAL STORMS WILL BE POSSIBLE SWD THROUGH THE PENINSULA GIVEN SEA-LAKE BREEZE INTERACTIONS WITHIN MOIST AIR MASS. A FEW STORMS WILL BE POSSIBLE ACROSS THE FL PENINSULA WHERE POCKETS OF STRONGER INSTABILITY CAN DEVELOP...GIVEN EXPECTED SUFFICIENT DEEP LAYER SHEAR. ...SRN TX TO FOUR CORNERS REGION... THUNDERSTORMS MAY BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF DEEP S TX/LOWER RIO GRANDE VALLEY NWWD INTO THE HIGHER TERRAIN OF NM ALONG SURFACE COLD FRONT. ADDITIONAL DEVELOPMENT IS LIKELY AS THIS BOUNDARY MOVES SOUTH AND WEST...BUT OVERALL WEAK INSTABILITY IS EXPECTED TO LIMIT AND LIKELY PRECLUDE SEVERE POTENTIAL. NWWD MOISTURE ADVECTION INTO SRN NM/ERN AZ WILL AID IN INCREASING POTENTIAL FOR THUNDERSTORM DEVELOPMENT TOWARD FOUR CORNERS REGION MONDAY AFTERNOON. ..PETERS.. 05/14/2006  From swody2 at goshenarc.org Mon May 15 05:23:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 May 2006 01:23:38 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150520 SWODY2 SPC AC 150519 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1219 AM CDT MON MAY 15 2006 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FURTHER AMPLIFICATION OF UPPER PATTERN EXPECTED THIS PERIOD...WHILE WRN RIDGE/ERN TROUGH CONFIGURATION PERSISTS. SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF THE ERN CONUS BENEATH UPPER TROUGH...AND OVER THE HIGHER ELEVATIONS ACROSS PORTIONS OF THE WEST. ANY SEVERE THREAT SHOULD REMAIN LIMITED TO A STRONGER CELL OR TWO OVER CENTRAL/SRN FL S OF WEAK COLD FRONT. ...CENTRAL/SRN FL... WEAK COLD FRONT IS EXPECTED TO LINGER/DRIFT SLOWLY SWD ACROSS FL THIS PERIOD...WHERE MOIST BOUNDARY LAYER BUT WEAK MID-LEVEL LAPSE RATES ARE ANTICIPATED. WITH MID-LEVEL FLOW NEAR 50 KT...A STRONGER STORM OR TWO COULD DEVELOP -- EITHER NEAR FRONT OR INVOF SEA-BREEZE BOUNDARIES -- WHICH COULD PRODUCE MARGINAL HAIL OR A LOCALLY-DAMAGING GUST. HOWEVER...OVERALL THREAT SHOULD REMAIN LIMITED BY LACK OF FAVORABLE THERMODYNAMICS. ..GOSS.. 05/15/2006  From swody2 at goshenarc.org Mon May 15 16:59:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 May 2006 12:59:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151656 SWODY2 SPC AC 151655 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CDT MON MAY 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FL... ...SYNOPSIS... LARGE SCALE PATTERN WILL REMAIN DOMINATED BY OMEGA-BLOCK OVER THE U.S. WITH STRONG UPPER LOW OVER THE EAST AND A LARGE RIDGE OVER THE ROCKIES AND INTERMOUNTAIN WEST. DEEP NLY FLOW IN WAKE OF ERN U.S. UPPER SYSTEM WILL MAINTAIN OFFSHORE FLOW WELL INTO THE GULF OF MEXICO AND LIMIT OVERALL THREAT OF STRONG TO SEVERE THUNDERSTORMS THROUGH THE PERIOD. EXCEPTION WILL REMAIN ACROSS THE SRN HALF OF FL WHERE BOUNDARY LAYER WILL REMAIN RELATIVELY MOIST /I.E. SURFACE DEW POINTS AROUND 70F/ AND WLY FLOW ALOFT WILL REMAIN SUFFICIENT FOR MODEST DEEP LAYER SHEAR. ...SRN FL... CLOUDS FROM RESIDUAL CONVECTION MAY LIMIT HEATING AND ASSOCIATED INSTABILITY DURING THE DAY OVER S FL. HOWEVER...QUALITY OF LOW LEVEL MOISTURE AND 30-40 KT EFFECTIVE BULK SHEAR SUGGEST EVEN MODEST HEATING WILL SUPPORT A FEW SEVERE THUNDERSTORMS TUESDAY AFTERNOON/EVENING. ACTIVITY WILL INCREASE BY THE EARLY AFTERNOON AHEAD OF A SLOW MOVING COLD FRONT ORIENTED E-W ACROSS CENTRAL FL AND ALONG OUTFLOW BOUNDARIES AND SEA BREEZES ACROSS SRN FL. SHOULD EVEN MODEST INSTABILITY DEVELOP...EXPECT ACTIVITY WILL ORGANIZE INTO MULTICELL CLUSTERS AND BRIEF SUPERCELLS WITH PRIMARY THREATS OF LARGE HAIL AND DAMAGING WINDS INTO THE EARLY EVENING. ..EVANS.. 05/15/2006  From swody2 at goshenarc.org Tue May 16 06:00:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 16 May 2006 02:00:12 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160556 SWODY2 SPC AC 160555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE MAY 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED LARGE-SCALE UPPER PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD AND BEYOND. STRONGER FLOW WILL REMAIN SPLIT IN BELTS AROUND BLOCKING RIDGE ENCOMPASSING MUCH OF THE INTERMOUNTAIN WEST...BEFORE MERGING INTO A BROAD TROUGH EAST OF THE PLAINS INTO THE WESTERN ATLANTIC. MODELS SUGGEST THAT A CLOSED LOW EMBEDDED WITHIN LATTER FEATURE WILL FINALLY LIFT NORTHEAST OF THE OHIO VALLEY LATER TODAY/TONIGHT...BEFORE CONTINUING NORTHEASTWARD INTO THE CANADIAN MARITIMES WEDNESDAY. THIS WILL BE ACCOMPANIED BY THE NORTHEASTWARD ACCELERATION OF A LOWER AMPLITUDE IMPULSE OUT OF THE BASE OF THE LARGER SCALE TROUGH NEAR EASTERN GULF COASTAL AREAS...THROUGH THE MID/SOUTH ATLANTIC COAST STATES BY LATE WEDNESDAY NIGHT. HOWEVER...AN UPSTREAM NORTHERN BRANCH SHORT WAVE TROUGH/JET STREAK IS PROGGED TO SUPPORT THE EVOLUTION OF ANOTHER CLOSED LOW AS IT DIGS OUT OF CENTRAL CANADA THROUGH THE UPPER GREAT LAKES REGION. ...EAST OF THE ROCKIES... THE PRIMARY FRONTAL ZONE ASSOCIATED WITH THE EASTERN TROUGH IS EXPECTED OFF THE SOUTH ATLANTIC COAST...AND SOUTH/EAST OF THE FLORIDA PENINSULA BY 12Z WEDNESDAY. IN ITS WAKE...BOUNDARY LAYER MOISTURE ACROSS MOST AREAS WILL BE SEASONABLY LOW. THIS MAY NOT PRECLUDE AREAS OF SCATTERED CONVECTIVE DEVELOPMENT...BUT POTENTIAL FOR STRONG/SEVERE THUNDERSTORMS IS EXPECTED TO REMAIN LOW. A LINGERING MID-LEVEL THERMAL TROUGH COULD PROVIDE THE FOCUS FOR SCATTERED THUNDERSTORMS WITH DAYTIME HEATING ACROSS THE ATLANTIC COAST STATES...MAINLY IN THE LEE OF THE CENTRAL/SOUTHERN APPALACHIANS. DIURNAL ACTIVITY IS POSSIBLE AS FAR TO THE SOUTH AND WEST AS THE CENTRAL GULF STATES. HOWEVER...THE MAIN CONVECTIVE POTENTIAL WEDNESDAY SEEMS LIKELY TO ACCOMPANY STRONGER MID/UPPER FORCING FOR UPWARD VERTICAL MOTION AHEAD OF DIGGING UPPER GREAT LAKES SHORT WAVE TROUGH. MODELS SUGGEST LAPSE RATES COULD BECOME FAIRLY STEEP ABOVE LOW-LEVEL THERMAL RIDGE IN ADVANCE OF REINFORCING COOL/DRY SURGE. AND... LOWER/MID 50S SURFACE DEW POINTS ARE GENERALLY EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE AROUND 500 J/KG. LOCALLY STRONGER DESTABILIZATION IS POSSIBLE...SUPPORTING THE DEVELOPMENT OF SCATTERED THUNDERSTORMS BY PEAK HEATING. FAVORABLE DEEP LAYER SHEAR ASSOCIATED WITH MODERATELY STRONG CYCLONIC MID-LEVEL FLOW IS EXPECTED TO SUPPORT ONE OR MORE CONVECTIVE BANDS...WHICH PROBABLY WILL BE ACCOMPANIED BY RISK OF GUSTY WINDS/HAIL WHICH COULD APPROACH OR BRIEFLY EXCEED SEVERE LIMITS. ACTIVITY SHOULD WEAKEN FAIRLY QUICKLY AFTER DARK AS IT SPREADS EASTWARD THROUGH THE LOWER OHIO VALLEY. ...ROCKIES AND INTERMOUNTAIN WEST... MOISTURE...MOSTLY TO THE SOUTH/WEST OF UPPER HIGH CENTER...IS EXPECTED TO REMAIN SUFFICIENT FOR SCATTERED THUNDERSTORM ACTIVITY WEDNESDAY. THIS WILL MOSTLY OCCUR IN RESPONSE TO HEATING ACROSS THE HIGHER TERRAIN. THOUGH POCKETS OF STRONGER INSTABILITY COULD DEVELOP...CAPE IN WEAKLY SHEARED REGIME IS EXPECTED TO AVERAGE ON THE ORDER OF A FEW HUNDRED J/KG. THIS WILL LIMIT STRENGTH OF UPDRAFTS...BUT STEEP LAPSE RATES WITH LARGE LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL PROVIDE FAVORABLE PROFILES FOR HIGHLY LOCALIZED/ISOLATED MICROBURSTS. ..KERR.. 05/16/2006  From swody2 at goshenarc.org Tue May 16 17:38:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 16 May 2006 13:38:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161735 SWODY2 SPC AC 161734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT TUE MAY 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY... INTENSIFYING UPPER SPEED MAX WILL DIG ACROSS MN TOWARD THE OH VALLEY WEDNESDAY FORCING SFC COLD FRONT SEWD TO A POSITION FROM SRN LOWER MI...ARCING INTO ERN NEB DURING THE LATE AFTERNOON HOURS. LARGE SCALE ASCENT WILL BE FOCUSED WITHIN EXIT REGION OF THIS SPEED MAX WHICH SHOULD ENHANCE CONVECTIVE POTENTIAL ALONG ADVANCING BOUNDARY BY EARLY AFTERNOON. LATEST MODEL GUIDANCE SUGGEST STRONG BOUNDARY LAYER HEATING...8.5-9C/KM LAPSE RATES IN THE LOWEST 3KM...WILL DEVELOP ACROSS THE CNTRL PLAINS EWD ALONG WIND SHIFT INTO CNTRL IA. THIS PLUME OF STRONG HEATING WILL DEVELOP/SPREAD EWD BENEATH COLD UPPER TROUGH ENHANCING SFC BASED INSTABILITY...500-1000J/KG. DESPITE MEAGER MOISTURE NOTED ACROSS THIS REGION...SFC DEW POINTS IN THE UPPER 40S TO NEAR 50F...COLD MID LEVEL TEMPS AND STEEP LAPSE RATES WILL YIELD FAVORABLE THERMODYNAMIC PROFILES FOR STRONG UPDRAFT DEVELOPMENT CAPABLE OF GENERATING AT LEAST MARGINALLY SEVERE HAIL. ACTIVITY SHOULD BE MOST CONCENTRATED DURING THE AFTERNOON INTO THE EVENING HOURS AS FRONT SURGES SOUTH TOWARD THE OH RIVER. ...PACIFIC NW... UPPER RIDGE WILL HOLD ACROSS THE WRN U.S. THIS PERIOD WITH WEAK SWLY FLOW EXPECTED TO GRADUALLY INCREASE OVER WA/ORE LATE IN THE PERIOD AS HEIGHTS BEGIN TO FALL. IT APPEARS ISOLATED THUNDERSTORMS SHOULD DEVELOP BENEATH THE UPPER RIDGE WHERE STRONG HEATING AND OROGRAPHIC LIFT WILL BE MAXIMIZED. FORECAST SOUNDINGS ALSO SUGGEST HAIL IS LIKELY WITH THE STRONGER UPDRAFTS. CONVECTION WILL BE STRONGLY DIURNAL AND DIE QUICKLY AFTER SUNSET. ..DARROW.. 05/16/2006  From swody2 at goshenarc.org Wed May 17 05:27:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 17 May 2006 01:27:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170524 SWODY2 SPC AC 170523 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 AM CDT WED MAY 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... BLOCKING UPPER HIGH CENTER REMAINS STRONG OVER THE INTERMOUNTAIN WEST...AND AN AMPLIFIED SPLIT FLOW PATTERN IS EXPECTED TO PERSIST ACROSS MUCH OF NORTH AMERICA THROUGH THIS FORECAST PERIOD. HOWEVER...A SIGNIFICANT IMPULSE LIFTING OUT OF THE NORTHEAST PACIFIC THROUGH RIDGE AXIS ACROSS THE CANADIAN ROCKIES WILL CONTRIBUTE TO MID-LEVEL HEIGHT FALLS LATER TODAY/TONIGHT. AND...FURTHER WEAKENING OF UPPER RIDGE WILL OCCUR SOUTHWARD THROUGH THE NORTHERN PACIFIC COAST STATES THURSDAY/THURSDAY NIGHT...AHEAD OF UPSTREAM TROUGH AXIS SLOWLY APPROACHING THE PACIFIC COAST. FARTHER EAST...MODELS INDICATE THAT A STRONG DIGGING JET STREAK IN THE NORTHERN BRANCH OF THE WESTERLIES WILL CONTRIBUTE TO THE DEVELOPMENT OF ANOTHER CLOSED LOW OVER THE GREAT LAKES/UPPER OHIO VALLEY REGION. THIS FEATURE IS PROGGED TO OVERSPREAD ACROSS MUCH OF THE REMAINDER OF THE NORTHEAST BY 12Z FRIDAY. WITH THE INTERMOUNTAIN WEST ONLY CONTINUING TO GRADUALLY MOISTEN...AND MOISTURE LEVELS EAST OF THE ROCKIES REMAINING SEASONABLY LOW UNDER THE INFLUENCE OF SUCCESSIVE COOL/DRY SURGES ASSOCIATED WITH PERSISTENT UPPER TROUGH...CONVECTIVE POTENTIAL IS EXPECTED TO REMAIN LIMITED. DESTABILIZATION IS EXPECTED TO BECOME SUFFICIENT FOR AREAS OF SCATTERED THUNDERSTORMS THURSDAY/THURSDAY NIGHT...BUT MOST ACTIVITY IS EXPECTED TO REMAIN RELATIVELY WEAK. ...EAST OF ROCKIES... THE LEADING EDGE OF STRONGER MID-LEVEL COOLING/LIFT IN EXIT REGION OF 70-90 KT CYCLONIC 500 MB JET STREAK STILL SEEMS LIKELY INTO MUCH OF THE NORTHERN/CENTRAL APPALACHIANS BY MIDDAY THURSDAY. THIS...IN CONJUNCTION WITH FAVORABLE OROGRAPHIC FORCING...IS EXPECTED TO SUPPORT INITIATION OF CONVECTIVE DEVELOPMENT...WHICH SHOULD DEVELOP EASTWARD WITH UPPER FORCING TOWARD THE HUDSON VALLEY AND MID ATLANTIC COASTAL AREAS THURSDAY AFTERNOON. THOUGH CAPE WILL BE WEAK...COOL THERMODYNAMIC PROFILES WILL BE SUPPORTIVE OF HAIL...PERHAPS LOCALLY GUSTY WINDS...IN STRONGER CELLS...SOME OF WHICH COULD APPROACH OR BRIEFLY EXCEED SEVERE CRITERIA. THREAT SHOULD DIMINISH QUICKLY THURSDAY EVENING WITH LOSS OF HEATING. OTHERWISE...BANDS OF CONVECTION AND SCATTERED THUNDERSTORMS ARE EXPECTED DURING THE DAYTIME HOURS SOUTH/SOUTHEAST OF DEVELOPING UPPER LOW...PARTICULARLY NEAR THE SOUTHERN FRINGE OF THE MID-LEVEL COLD CORE ACROSS THE OHIO VALLEY. MODELS SUGGEST THAT ADDITIONAL THUNDERSTORMS ARE POSSIBLE BY LATE THURSDAY/THURSDAY NIGHT FROM PARTS OF THE MID MISSOURI VALLEY INTO THE MIDDLE MISSISSIPPI VALLEY. THIS IS EXPECTED AS MOISTURE OF PACIFIC ORIGINS ADVECTS AROUND CREST OF UPPER RIDGE INTO FAVORABLE LOWER/MID TROPOSPHERIC WARM ADVECTION REGIME EAST OF RIDGE...AND IN WAKE OF CLOSED LOW. ...INTERMOUNTAIN WEST/PACIFIC COAST STATES... SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED ONCE AGAIN THURSDAY... MAINLY SOUTH/WEST OF UPPER RIDGE...AND IN RESPONSE TO HEATING ACROSS THE HIGHER TERRAIN. MODELS SUGGEST THAT A WEAK IMPULSE EMBEDDED WITHIN STRENGTHENING SOUTHERLY MID/UPPER FLOW COULD CONTRIBUTE TO MORE EXTENSIVE CONVECTIVE DEVELOPMENT IN THE LEE OF THE SOUTHERN CASCADES AFTER PEAK HEATING. CAPE IS EXPECTED TO REMAIN WEAK...LIMITING STRENGTH OF UPDRAFTS...BUT 700-500 MB FLOW ON THE ORDER OF 30 TO 40 KTS COULD ENHANCE DOWNBURST POTENTIAL IN DRY DEEP MIXED BOUNDARY LAYER. ISOLATED DAMAGING WIND GUSTS APPEAR POSSIBLE THROUGH THURSDAY EVENING...MAINLY ACROSS PARTS OF CENTRAL/EASTERN OREGON. ..KERR.. 05/17/2006  From swody2 at goshenarc.org Fri May 19 06:01:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 May 2006 02:01:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190558 SWODY2 SPC AC 190557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT FRI MAY 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN KS/MO SEWD INTO THE SRN PORTION OF THE TN VALLEY... ...SYNOPSIS... OVERALL PATTERN WILL CHANGE LITTLE WITH HIGHLY AMPLIFIED TROUGH REMAINING ACROSS THE WEST AND A STRONG TROUGH LOCATED ACROSS THE NERN QUARTER OF THE COUNTRY. THE PAST FEW MODEL RUNS HAVE EVOLVED TO A STRONGER SHORTWAVE TROUGH/JET MAX/COLD FRONT SHIFTING FROM THE WRN GREAT LAKES INTO NY DURING THE PERIOD. THE REMNANTS OF A WEAK FRONT ARE FORECAST TO STRETCH FROM SRN KS ESEWD INTO THE SRN PORTION OF THE TN VALLEY AND THEN EWD INTO THE CAROLINAS. BETWEEN THE TWO UPPER TROUGHS...MID/HIGH LEVEL MOISTURE...TRAPPED BENEATH UPPER RIDGE OVER THE ROCKIES...COMBINED WITH DAYTIME HEATING WILL RESULT IN SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE HIGHER TERRAIN. ...ERN KS/MO SEWD ACROSS NRN AR AND INTO THE SRN TN VALLEY AREA... A MOSTLY NON SEVERE MCS IS EXPECTED TO BE MOVING THROUGH THE CAROLINAS EARLY IN THE PERIOD...AS ASSOCIATED SPEED MAX MOVES OFFSHORE. ONCE THESE STORMS MOVE OFFSHORE...UNCERTAINTY EXISTS WHEN AND WHERE MORE STORMS WILL REDEVELOP. ALTHOUGH FRONT IS FORECAST TO REMAIN NEARLY QUASI-STATIONARY THROUGH THE DAY...500 MB HEIGHTS ARE PROGGED TO RISE SLIGHTLY. NO SHORTWAVE TROUGHS ARE EVIDENT WITHIN 30-40 KT NWLY FLOW MID LEVEL FLOW...THOUGH VEERING WIND PROFILES WOULD PROVIDE FAVORABLE SHEAR FOR SEVERE STORMS. ALTHOUGH MODEL FORECAST OF MID TO UPPER 60S DEWPOINTS APPEARS TO BE OVERESTIMATED...SURFACE DEWPOINTS NEAR 60F AND 850-500 MB LAPSE RATES AROUND 7.5 C/KM SHOULD YIELD AFTERNOON MLCAPES FROM 2000-2500 J/KG. VERY WARM TEMPERATURES AND DRY AIR BETWEEN 700-850 MB SHOULD INHIBIT CONVECTION SOUTH AND WEST OF FRONT. HOWEVER ANY FORCING ON THE COOL SIDE OF THE FRONT MAY PROVIDE ENOUGH LIFT FOR PARCELS TO REACH THE LFC. IF STORMS DO DEVELOP...THE SHEAR AND DEGREE OF INSTABILITY WOULD SUPPORT STORMS WITH SEVERE HAIL AND DAMAGING WINDS. ...WI... THOUGH SLIGHT DIFFERENCES EXIST IN TIMING OF SHORTWAVE TROUGH/ SPEED MAX...MODELS SUGGEST STRONG FORCING/COLD FRONT WILL MOVE ACROSS WI AROUND EARLY/MID AFTERNOON. THE STRENGTH OF THIS SYSTEM AND VERY STRONG VERTICAL WIND PROFILES APPEAR SUPPORTIVE OF A SEVERE STORM THREAT. THE ONLY QUESTION IS THE LIMITED AMOUNT OF MOISTURE IN BOUNDARY LAYER SINCE RETURN OF RICHER GULF MOISTURE WILL BE CONFINED TO THE GULF COASTAL STATES. HOWEVER...A HIGHER RISK FOR SEVERE WEATHER WOULD BE NEEDED IF THE BOUNDARY LAYER MOISTENS MORE THAN CURRENTLY EXPECTED. ...NRN ID AND WRN MT... EMBEDDED SHORTWAVE TROUGHS MOVING NEWD WITHIN 40-50 KT MID LEVEL FLOW MAY RESULT IN A FEW STORMS WITH A POTENTIAL FOR BRIEF STRONG WIND GUSTS DURING THE AFTERNOON/EVENING HOURS. ..IMY.. 05/19/2006  From swody2 at goshenarc.org Fri May 19 17:24:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 May 2006 13:24:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191721 SWODY2 SPC AC 191719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1219 PM CDT FRI MAY 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN AND CNTRL PLAINS/OZARKS AND TN VALLEY... ...SRN AND CNTRL PLAINS/MID MS VALLEY/TN VALLEY... NORTHWEST FLOW WILL REMAIN IN PLACE TONIGHT TROUGH SATURDAY AS A COLD FRONT MOVES SLOWLY SWD INTO OK..AR...MS AND AL BY SATURDAY AFTERNOON. BY MIDDAY ON SATURDAY...WARMING SFC TEMPS...THE WEAKENING CAPPING INVERSION AND STRENGTHENING LOW-LEVEL CONVERGENCE SHOULD ALLOW ISOLATED TO SCATTERED STORMS TO INITIATE ALONG AND NEAR THE BOUNDARY. AFTERNOON FORECAST SOUNDINGS ACROSS KS...NRN OK...AR AND TN SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE WHICH WOULD BE FAVORABLE FOR SUPERCELL DEVELOPMENT NEAR POCKETS OF MODERATE INSTABILITY. STRONG STORMS WITH THE POTENTIAL FOR LARGE HAIL WILL BE MOST LIKELY IN THE PLAINS AND OZARKS WHERE MID-LEVEL LAPSE RATES ARE FORECAST TO BE THE STEEPEST. WIND DAMAGE WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS ESPECIALLY IN AREAS WHERE LOW-LEVEL LAPSE RATES ARE MAXIMIZED. ...NRN ROCKIES AND NRN HIGH PLAINS... AN UPPER-LEVEL RIDGE OVER THE ROCKIES TONIGHT WILL MOVE SLOWLY EWD. IN RESPONSE...HEIGHTS WILL FALL AND LARGE-SCALE ASCENT WILL INCREASE ACROSS THE NRN ROCKIES AND NRN HIGH PLAINS SATURDAY. AT THE SFC...A FRONTAL BOUNDARY SHOULD BE IN PLACE ACROSS CNTRL MT AND STORMS SHOULD INITIATE ALONG THE BOUNDARY AND IN THE HIGHER TERRAIN AROUND MIDDAY. AFTERNOON FORECAST SOUNDINGS IN CNTRL MT SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES WHICH SHOULD BE FAVORABLE FOR MARGINALLY SEVERE STORMS NEAR PEAK HEATING. HOWEVER...THE AMOUNT OF DESTABILIZATION THAT WILL OCCUR SATURDAY IN THE NRN HIGH PLAINS REMAINS HIGHLY UNCERTAIN. IF ENOUGH INSTABILITY DEVELOPS...SUPERCELLS WITH LARGE HAIL AND/OR WIND DAMAGE WOULD BE POSSIBLE. AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...UPPER MIDWEST... A BELT OF STRONG NORTHWEST MID-LEVEL FLOW IS FORECAST TO REMAIN IN PLACE ACROSS THE UPPER MIDWEST THROUGH SATURDAY. AS A 90 KT JET MAX PUNCHES INTO THE REGION SATURDAY AFTERNOON...INCREASING LARGE-SCALE ASCENT MAY BE ENOUGH TO ALLOW ISOLATED STORMS TO INITIATE AND MOVE SEWD ACROSS THE REGION. RELATIVELY COLD TEMPS ALOFT AND THE STRONG VERTICAL SHEAR MAY BE ENOUGH FOR A FEW HAIL STORMS. HOWEVER...THE DEGREE OF DESTABILIZATION REMAINS UNCERTAIN ATTM. IF A MARGINAL SEVERE THREAT DEVELOPS IN THE AFTERNOON...THE HAIL POTENTIAL WOULD LIKELY REMAIN VERY ISOLATED. ..BROYLES.. 05/19/2006  From swody2 at goshenarc.org Sat May 20 06:10:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 02:10:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200607 SWODY2 SPC AC 200606 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0106 AM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE MIDDLE MS VALLEY AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE PACIFIC NW AND NRN ROCKIES... ...SYNOPSIS... PATTERN WILL CHANGE LITTLE THROUGH SUNDAY WITH AN UPPER LOW DOMINATING MUCH OF THE ERN HALF OF THE COUNTRY AND AN UPPER RIDGE OVER THE ROCKIES. A SERIES OF SHORTWAVE TROUGHS EMANATING FROM ERN PACIFIC UPPER LOW WILL LIFT NWD THROUGH CA AND THE PACIFIC NW. AT THE SURFACE A FRONT WILL SETTLE SWD INTO THE TN VALLEY AND EXTEND WNWWD THROUGH SRN MO...NRN OK AND NWWD INTO THE CNTRL HIGH PLAINS. ...SERN KS...NERN OK THROUGH THE LOWER MS AND WRN TN VALLEYS... A RELATIVELY MOIST BOUNDARY LAYER WILL PERSIST NEAR FRONT FROM THE TN AND MID MS VALLEYS INTO NRN OK AND PARTS OF THE CNTRL PLAINS. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...THE ATMOSPHERE SHOULD BECOME MODERATELY UNSTABLE BY AFTERNOON. THE FRONT WILL LIKELY SERVE AS A FOCUS FOR THUNDERSTORMS THIS PERIOD. A FEW STORMS MAY BE IN PROGRESS EARLY SUNDAY IN WARM ADVECTION REGIME N OF FRONT OVER PART OF THE LOWER MS VALLEY. THE NATURE OF CONVECTIVE EVOLUTION REMAINS A BIT UNCERTAIN AT THIS TIME GIVEN EXPECTED LIMITED DEEP LAYER FORCING. HOWEVER...SOME POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE BOUNDARY AS CAP WEAKENS SUNDAY AFTERNOON. OTHER STORMS MAY DEVELOP OVERNIGHT FROM THE SRN PLAINS INTO THE LOWER MS VALLEY AS THE LOW LEVEL JET STRENGTHENS. ELY LOW LEVEL FLOW NEAR THE FRONT VEERING TO WNWLY 25 TO 30 KT AT 6 KM SUGGEST VERTICAL SHEAR WILL BE AT LEAST MARGINALLY FAVORABLE FOR ORGANIZED STORMS. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS. ...CNTRL HIGH PLAINS... THIS AREA WILL BE IN CLOSER PROXIMITY TO UPPER RIDGE. HOWEVER... STORMS MAY DEVELOP ALONG NWWD EXTENTION OF FRONT OVER THE CNTRL HIGH PLAINS AS CAP WEAKENS SUNDAY AFTERNOON. DEWPOINTS IN THE 50S AND STEEP LAPSE RATES SHOULD RESULT IN MLCAPE ON THE ORDER OF 1000 TO 1500 J/KG. MID LEVEL FLOW WILL NOT BE PARTICULARLY STRONG DUE TO PROXIMITY OF UPPER RIDGE. HOWEVER...SELY LOW LEVEL FLOW VEERING TO NWLY 20 KT AT 6 KM SHOULD RESULT IN DEEP LAYER SHEAR MARGINALLY SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS AS ACTIVITY DEVELOPS SEWD THROUGH MID EVENING. ...PACIFIC NW AND NRN ROCKIES AREA... EXTENT AND MAGNITUDE OF SEVERE THREAT IN THIS AREA WILL DEPEND ON TIMING OF IMPULSES AND DEGREE OF CLOUD COVER. LOW LEVEL DEWPOINTS IN THE UPPER 40S TO LOWER 50S WILL PERSIST WITHIN THE STEEP LAPSE RATE ENVIRONMENT WITH MLCAPE ON THE ORDER OF 400 TO 800 J/KG BY AFTERNOON. STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN...POSSIBLY AIDED BY DEEP LAYER LARGER SCALE ASCENT ASSOCIATED WITH NWD ADVANCING IMPULSES. STRONG MIDDLE AND UPPER SLY FLOW WILL PERSIST OVER THIS REGION CONTRIBUTING TO FAVORABLE VERTICAL SHEAR PROFILES FOR SUPERCELLS. THERMODYNAMIC ENVIRONMENT SHOULD SUPPORT POTENTIAL FOR BOTH LARGE HAIL AND DAMAGING WIND DURING THE AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 05/20/2006  From swody2 at goshenarc.org Sat May 20 06:34:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 02:34:38 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200631 SWODY2 SPC AC 200630 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0130 AM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE MIDDLE MS VALLEY AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE PACIFIC NW AND NRN ROCKIES... ...SYNOPSIS... PATTERN WILL CHANGE LITTLE THROUGH SUNDAY WITH AN UPPER LOW DOMINATING MUCH OF THE ERN HALF OF THE COUNTRY AND AN UPPER RIDGE OVER THE ROCKIES. A SERIES OF SHORTWAVE TROUGHS EMANATING FROM ERN PACIFIC UPPER LOW WILL LIFT NWD THROUGH CA AND THE PACIFIC NW. AT THE SURFACE A FRONT WILL SETTLE SWD INTO THE TN VALLEY AND EXTEND WNWWD THROUGH SRN MO...NRN OK AND NWWD INTO THE CNTRL HIGH PLAINS. ...SERN KS...NERN OK THROUGH THE LOWER MS AND WRN TN VALLEYS... A RELATIVELY MOIST BOUNDARY LAYER WILL PERSIST NEAR FRONT FROM THE TN AND MID MS VALLEYS INTO NRN OK AND PARTS OF THE CNTRL PLAINS. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...THE ATMOSPHERE SHOULD BECOME MODERATELY UNSTABLE BY AFTERNOON. THE FRONT WILL LIKELY SERVE AS A FOCUS FOR THUNDERSTORMS THIS PERIOD. A FEW STORMS MAY BE IN PROGRESS EARLY SUNDAY IN WARM ADVECTION REGIME N OF FRONT OVER PART OF THE LOWER MS VALLEY. THE NATURE OF CONVECTIVE EVOLUTION REMAINS A BIT UNCERTAIN AT THIS TIME GIVEN EXPECTED LIMITED DEEP LAYER FORCING. HOWEVER...SOME POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE BOUNDARY AS CAP WEAKENS SUNDAY AFTERNOON. OTHER STORMS MAY DEVELOP OVERNIGHT FROM THE SRN PLAINS INTO THE LOWER MS VALLEY AS THE LOW LEVEL JET STRENGTHENS. ELY LOW LEVEL FLOW NEAR THE FRONT VEERING TO WNWLY 25 TO 30 KT AT 6 KM SUGGEST VERTICAL SHEAR WILL BE AT LEAST MARGINALLY FAVORABLE FOR ORGANIZED STORMS. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS. ...CNTRL HIGH PLAINS... THIS AREA WILL BE IN CLOSER PROXIMITY TO UPPER RIDGE. HOWEVER... STORMS MAY DEVELOP ALONG NWWD EXTENTION OF FRONT OVER THE CNTRL HIGH PLAINS AS CAP WEAKENS SUNDAY AFTERNOON. DEWPOINTS IN THE 50S AND STEEP LAPSE RATES SHOULD RESULT IN MLCAPE ON THE ORDER OF 1000 TO 1500 J/KG. MID LEVEL FLOW WILL NOT BE PARTICULARLY STRONG DUE TO PROXIMITY OF UPPER RIDGE. HOWEVER...SELY LOW LEVEL FLOW VEERING TO NWLY 20 KT AT 6 KM SHOULD RESULT IN DEEP LAYER SHEAR MARGINALLY SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS AS ACTIVITY DEVELOPS SEWD THROUGH MID EVENING. ...PACIFIC NW AND NRN ROCKIES AREA... EXTENT AND MAGNITUDE OF SEVERE THREAT IN THIS AREA WILL DEPEND ON TIMING OF IMPULSES AND DEGREE OF CLOUD COVER. LOW LEVEL DEWPOINTS IN THE UPPER 40S TO LOWER 50S WILL PERSIST WITHIN THE STEEP LAPSE RATE ENVIRONMENT WITH MLCAPE ON THE ORDER OF 400 TO 800 J/KG BY AFTERNOON. STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN...POSSIBLY AIDED BY DEEP LAYER LARGER SCALE ASCENT ASSOCIATED WITH NWD ADVANCING IMPULSES. STRONG MIDDLE AND UPPER SLY FLOW WILL PERSIST OVER THIS REGION CONTRIBUTING TO FAVORABLE VERTICAL SHEAR PROFILES FOR SUPERCELLS. THERMODYNAMIC ENVIRONMENT SHOULD SUPPORT POTENTIAL FOR BOTH LARGE HAIL AND DAMAGING WIND DURING THE AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 05/20/2006  From swody2 at goshenarc.org Sat May 20 17:31:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 13:31:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201728 SWODY2 SPC AC 201727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL HIGH PLAINS...SRN PLAINS AND MID MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WA AND ORE... ...MID MS VALLEY... A NORTHWEST FLOW PATTERN WILL LIKELY REMAIN IN PLACE ACROSS THE REGION TONIGHT INTO SUNDAY AS SLY FLOW RETURNS LOW-LEVEL MOISTURE NWD INTO THE MID MS VALLEY. SFC DEWPOINTS IN THE 60S F SHOULD RESULT IN AN AXIS OF MODERATE INSTABILITY BY AFTERNOON EXTENDING FROM THE OZARK PLATEAU EWD ACROSS WRN TN. STORMS SHOULD DEVELOP ALONG THE INSTABILITY AXIS WITH THE GREATEST CONVECTIVE COVERAGE AHEAD OF ANY SHORTWAVE TROUGH THAT CROSSES THE REGION IN THE AFTERNOON AND/OR EVENING. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE REGION SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES WITH STEEP LAPSE RATES ESPECIALLY ACROSS THE WRN OZARKS WHICH WOULD BE FAVORABLE FOR SUPERCELLS. LARGE HAIL AND WIND DAMAGE WOULD BE LIKELY WITH SUPERCELLS WITH A SEVERE THREAT LIKELY PERSISTING IN THE EVENING WITH ANY MCS THAT ORGANIZES ACROSS THE REGION. ...CNTRL HIGH PLAINS... AN UPPER-LEVEL RIDGE WILL SLOWLY MOVE EWD ACROSS THE HIGH PLAINS SUNDAY WITH A LEE TROUGH IN PLACE. AS CONVERGENCE INCREASES ALONG THE TROUGH/DRYLINE...SCATTERED CONVECTIVE INITIATION WILL BE LIKELY. STORMS SHOULD GRADUALLY INTENSIFY MOVING EWD ACROSS THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE HIGH PLAINS SHOW MODERATE VERTICAL SHEAR PROFILES WITH STRONG DIRECTIONAL SHEAR BELOW 500 MB WHICH WILL BE FAVORABLE FOR SUPERCELLS. STEEP LAPSE RATES AND THE MODERATE INSTABILITY SUGGEST HAIL WILL BE LIKELY WITH THE STRONGER STORMS. IN ADDITION...LARGE SFC TEMP-DEWPOINT SPREADS AND THE STRENGTHENING LOW-LEVEL JET MAY ALSO ENHANCE THE WIND DAMAGE POTENTIAL WITH THE STRONGER CONVECTIVE CLUSTERS IN THE EVENING. ...NWRN US... A HIGH PLAINS UPPER-LEVEL RIDGE IS FORECAST TO SLOWLY MOVE EWD AS SLY FLOW ALOFT CONTINUES ACROSS THE NWRN STATES. AT THE LOWER ELEVATIONS...SFC DEWPOINTS IN THE 50S F ACROSS NE ORE/SE WA AND IN WRN/CNTRL MT SHOULD BE FAVORABLE FOR POCKETS OF MODERATE INSTABILITY BY MIDDAY. IN ADDITION...FORECAST SOUNDINGS SHOW STRONG DIRECTIONAL SHEAR PROFILES RESULTING IN MODERATE TO STRONG VERTICAL SHEAR PROFILES SUGGESTING SUPERCELLS WILL BE POSSIBLE WITH STORMS THAT INITIATE SUNDAY AFTERNOON. STEEP LAPSE RATES AND INVERTED V-SOUNDINGS WILL MAKE HAIL AND WIND DAMAGE LIKELY WITH THE STRONGER CELLS DURING THE LATE AFTERNOON AND EARLY EVENING. ..BROYLES.. 05/20/2006  From swody2 at goshenarc.org Sun May 21 06:19:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 May 2006 02:19:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210616 SWODY2 SPC AC 210614 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 AM CDT SUN MAY 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT BASIN AREA THROUGH THE CNTRL ROCKIES AND THE CNTRL HIGH PLAINS... ...SYNOPSIS... UPPER PATTERN WILL REMAIN CHARACTERIZED BY AN UPPER LOW OVER THE ERN STATES AND AN UPPER RIDGE OVER THE CNTRL PART OF THE COUNTRY. THE STRONG SHORTWAVE TROUGH OVER THE ERN PACIFIC WILL EJECT NEWD INTO THE GREAT BASIN...REACHING THE CNTRL ROCKIES MONDAY EVENING. A STRONG COLD FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH THROUGH THE GREAT BASIN. THIS BOUNDARY WILL REACH THE CNTRL AND NRN HIGH PLAINS LATE MONDAY NIGHT. FARTHER EAST A QUASISTATIONARY FRONT WILL EXTEND FROM THE CAROLINAS WNWWD THROUGH THE MIDDLE MS VALLEY THEN NWWD INTO THE CNTRL AND NRN PLAINS. ERN PORTIONS OF THE FRONT MAY SETTLE SLOWLY SWD THROUGH THE CAROLINAS. ...NRN AZ THROUGH UT...CO AND THE CNTRL HIGH PLAINS... MOISTURE WILL REMAIN LIMITED FROM THE GREAT BASIN INTO THE CNTRL ROCKIES. HOWEVER...STEEP LAPSE RATES AND STRONG SURFACE HEATING WILL PROMOTE AT LEAST MARGINAL INSTABILITY WITH MLCAPE AROUND 500 J/KG. ASCENT ASSOCIATED WITH EJECTING SHORTWAVE TROUGH WITHIN THE STEEP LAPSE RATE ENVIRONMENT AND FRONTAL FORCING WILL PROMOTE THE DEVELOPMENT OF HIGH BASED STORMS THAT WILL SPREAD THROUGH PARTS OF AZ INTO UT DURING THE DAY. DEEP INVERTED-V BOUNDARY LAYERS SUGGEST PRIMARY THREAT WILL BE ISOLATED DAMAGING WIND AS CLUSTERS OF STORMS SPREAD NEWD. OTHER STORMS MAY DEVELOP OVER THE HIGHER TERRAIN OF CO PROMOTED BY STRONG SURFACE HEATING AND OROGRAPHIC FORCING. VERTICAL SHEAR PROFILES WILL INCREASE DURING THE AFTERNOON...ESPECIALLY OVER THE WRN HALF OF CO AS THE MID LEVEL JET LIFTS NEWD. THESE STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED DAMAGING WIND AND HAIL. ADDITIONAL STORMS MAY DEVELOP FARTHER EAST OVER THE CNTRL HIGH PLAINS BY LATE AFTERNOON INTO THE EVENING ALONG THE WRN EDGE OF THE DEEPER MOISTURE WHERE MIXING AND SURFACE HEATING WILL WEAKEN CAP. INSTABILITY WILL BE STRONGER IN THIS AREA OWING TO RICHER LOW LEVEL MOISTURE WITH MLCAPE FROM 1000 TO 1500 J/KG. VERTICAL SHEAR WILL ONLY BE MARGINALLY SUPPORTIVE OF ORGANIZED STORMS DURING THE AFTERNOON...BUT WILL LIKELY INCREASE INTO THE EVENING AS MID LEVEL JET LIFTS NEWD THROUGH CO. ISOLATED DAMAGING WIND AND LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ACTIVITY MAY PERSIST INTO THE EVENING AS ASCENT ACCOMPANYING EJECTING SHORTWAVE TROUGH SPREADS EWD INTO THE HIGH PLAINS. ...TN VALLEY THROUGH SC... A STRONG MID LEVEL JET WILL MOVE THROUGH THE MID ATLANTIC AND OFFSHORE MONDAY NIGHT WITH HEIGHT RISES AND WEAKENING BOUNDARY LAYER FLOW IN ITS WAKE. THE ATMOSPHERE MAY ONCE AGAIN BECOME MODERATELY UNSTABLE ALONG AND S OF SURFACE FRONT ACROSS PARTS OF THE TN VALLEY THROUGH SC. HOWEVER...THE WEAKENING LOW LEVEL FLOW WILL LIMIT CONVERGENCE AND MAY SERVE AS AN OVERALL LIMITING FACTOR FOR SEVERE WEATHER. STILL...POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE FRONT. A FEW STRONG STORMS CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE THE PRIMARY THREATS THROUGH EARLY EVENING. ..DIAL.. 05/21/2006  From swody2 at goshenarc.org Sun May 21 17:23:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 May 2006 13:23:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211720 SWODY2 SPC AC 211718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1218 PM CDT SUN MAY 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS...CNTRL ROCKIES AND INTERMOUNTAIN WEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN ATLANTIC SEABOARD AND THE SRN APPALACHIAN MTNS... ...HIGH PLAINS/CNTRL ROCKIES AND INTERMOUNTAIN WEST... A VIGOROUS UPPER-LEVEL TROUGH IS FORECAST TO MOVE NEWD ACROSS THE SWRN U.S. MONDAY. AHEAD OF THE SYSTEM...STRONG LARGE-SCALE ASCENT WILL SPREAD NEWD ACROSS THE FOUR CORNERS REGION INTO CO DURING THE AFTERNOON AND EVENING. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK ACROSS THE REGION MONDAY...THE STRONG LIFT...STEEP LAPSE RATES AND STRONG VERTICAL SHEAR ASSOCIATED WITH THE UPPER-TROUGH SHOULD BE ENOUGH FOR SCATTERED STRONG THUNDERSTORM DEVELOPMENT. A POTENTIAL FOR HAIL AND ISOLATED WIND DAMAGE WILL BE POSSIBLE WITH STORMS THAT DEVELOP NEAR AREAS WITH ENHANCED INSTABILITY IN THE LATE AFTERNOON AND/OR EARLY EVENING. FURTHER NORTHEAST ACROSS CO AND THE HIGH PLAINS...A LEAD SHORTWAVE TROUGH IS FORECAST TO MOVE NEWD INTO THE HIGH PLAINS AHEAD OF THE APPROACHING UPPER-LEVEL SYSTEM. THIS COMBINED WITH SFC HEATING SHOULD ALLOW ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND EAST OF THE FRONT RANGE MONDAY AFTERNOON WITH STORMS INCREASING IN COVERAGE DURING THE LATE AFTERNOON AND EVENING. AS STORMS MOVE EWD INTO THE GREATER MOISTURE AND INSTABILITY...A SEVERE THREAT SHOULD DEVELOP DUE TO THE MODERATE VERTICAL SHEAR PROFILES AND STEEP LAPSE RATES IN PLACE. ...SRN ATLANTIC SEABOARD AND SRN APPALACHIAN MTNS... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SHORTWAVE TROUGH EMBEDDED IN THE NORTHWEST FLOW PATTERN ACROSS THE UPPER MIDWEST. THIS FEATURE IS FORECAST TO MOVE SEWD ACROSS THE MID MS VALLEY INTO THE SRN APPALACHIAN MTNS MONDAY. AT THE SFC...A NEARLY STATIONARY FRONT SHOULD BE IN PLACE FROM NRN AL EXTENDING ESEWD ACROSS NRN GA INTO SC. THE LARGE-SCALE ASCENT AHEAD OF THE APPROACHING SHORTWAVE COMBINED WITH WARMING SFC TEMPS DURING THE DAY...SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION ALONG THE BOUNDARY. BY AFTERNOON...SCATTERED THUNDERSTORMS SHOULD DEVELOP AND MOVE ESEWD ACROSS THE REGION. FORECAST SOUNDINGS ACROSS THE REGION MONDAY AFTERNOON SHOW SFC DEWPOINTS IN THE 60S F WITH MODERATE VERTICAL SHEAR PROFILES SUGGESTING A FEW SUPERCELLS WILL BE POSSIBLE. LARGE HAIL AND WIND DAMAGE WOULD LIKELY BE THE PRIMARY THREATS AS AN MCS DEVELOPS AND MOVES EWD ACROSS SC IN THE LATE AFTERNOON AND EVENING. ..BROYLES.. 05/21/2006  From swody2 at goshenarc.org Mon May 22 06:15:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 May 2006 02:15:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220610 SWODY2 SPC AC 220609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT MON MAY 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND NRN PLAINS AND MIDDLE MS VALLEY AREAS... ...SYNOPSIS... A STRONG SHORTWAVE TROUGH NOW MOVING INTO SRN CA WILL EJECT NEWD INTO THE CNTRL PLAINS TUESDAY RESULTING IN DE AMPLIFICATION OF THE UPPER RIDGE. A COLD FRONT WILL ACCOMPANY THIS FEATURE. BY MID AFTERNOON THE FRONT SHOULD EXTEND FROM A SURFACE LOW IN SD SWD THROUGH CNTRL NEB AND INTO WRN KS. DRYLINE WILL STRETCH FROM WRN TX NWD THROUGH N CNTRL KS. THE COLD FRONT WILL OVERTAKE THE KS DRYLINE AS IT CONTINUES EWD OVERNIGHT. A WEAK FRONT WILL PERSIST FROM THE SERN STATES NWWD THROUGH THE MID MS VALLEY...ERN NEB TO THE SURFACE LOW IN SD. A COLD FRONT WILL MOVE FROM ERN MT INTO ND AS AN IMPULSE EJECTS NEWD THROUGH MT INTO SWRN CANADA. ...CNTRL PLAINS THROUGH PORTIONS OF THE MIDDLE MS VALLEY... CORRIDOR OF MID 60S DEWPOINTS NOW RESIDING IN VICINITY OF FRONT FROM KS INTO THE LOWER MS VALLEY WILL ADVECT NWD MONDAY INTO MONDAY NIGHT AS THE LOW LEVEL JET STRENGTHENS IN ASSOCIATION WITH DEVELOPING LEE TROUGH. STRENGTHENING 700-500 MB FLOW ACCOMPANYING THE EJECTING UPPER TROUGH WILL ADVECT STEEP MID LEVEL LAPSE RATES EWD INTO THE CNTRL PLAINS ABOVE THE MOIST AXIS. THIS WILL RESULT IN MODERATE INSTABILITY AS AFTERNOON HEATING COMMENCES WITH MLCAPE AROUND 2000 J/KG POSSIBLE FROM KS INTO NEB. STORMS ARE EXPECTED TO REDEVELOP AND INTENSIFY ALONG AND AHEAD OF THE FRONT WITHIN ZONE OF INCREASING DEEP LAYER ASCENT ASSOCIATED WITH EJECTING SHORTWAVE TROUGH DURING THE AFTERNOON. VERTICAL SHEAR PROFILES WILL INCREASE AS A MID LEVEL JET ROTATES ENEWD THROUGH BASE OF UPPER TROUGH RESULTING IN FAVORABLE SHEAR PROFILES FOR ORGANIZED STORMS INCLUDING SUPERCELLS. SOME STORMS MAY EVENTUALLY EVOLVE INTO LINES AND CLUSTERS...ESPECIALLY ACROSS PARTS OF NEB INTO SD. LARGE HAIL AND DAMAGING WIND MAY ACCOMPANY THE STRONGER STORMS. ISOLATED TORNADOES MAY ALSO BE POSSIBLE...ESPECIALLY AS THE LOW LEVEL JET STRENGTHENS FROM LATE AFTERNOON INTO THE EVENING. ACTIVITY WILL SPREAD INTO PARTS OF THE MIDDLE MS VALLEY DURING THE EVENING WITH A CONTINUED THREAT OF SEVERE WEATHER. STORMS MAY ALSO DEVELOP SWD INTO KS WHERE SHEAR PROFILES WILL BE FAVORABLE FOR SUSTAINED DISCRETE SUPERCELLS. STORMS MAY BE MORE ISOLATED WITH SWD EXTENT WHERE DEEP LAYER FORCING WILL BE WEAKER AND CAP WILL BE STRONGER. LARGE HAIL AND ISOLATED TORNADOES WILL BE POSSIBLE WITH ANY STORMS THAT MANAGE TO DEVELOP IN KS. PORTIONS OF THE CNTRL PLAINS MAY NEED TO BE UPGRADED TO MODERATE RISK IN LATER OUTLOOKS. ...NRN HIGH PLAINS... WEAK VERTICAL SHEAR IN THIS REGION MAY SERVE AS A LIMITING FACTOR FOR AN ORGANIZED SEVERE THREAT. HOWEVER...LOW LEVEL DEWPOINTS IN THE UPPER 50S TO AROUND 60 ARE EXPECTED TO ADVECT NWD INTO THIS REGION BENEATH STEEP LAPSE RATES. WHERE SURFACE HEATING OCCURS...MODERATE INSTABILITY WILL LIKELY DEVELOP DURING THE AFTERNOON. STORMS SHOULD REDEVELOP AND INTENSIFY IN VICINITY OF THE EWD ADVANCING FRONT. STORM MODE WILL LIKELY BE MULTICELLULAR GIVEN THE EXPECTED WEAK VERTICAL SHEAR. HOWEVER....STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL AND DAMAGING WIND GUSTS AS ACTIVITY SPREADS EWD THROUGH ERN MT AND WRN ND DURING THE AFTERNOON. ..DIAL.. 05/22/2006  From swody2 at goshenarc.org Mon May 22 17:36:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 May 2006 13:36:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221733 SWODY2 SPC AC 221732 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CDT MON MAY 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN AND CENTRAL PLAINS.... ...SYNOPSIS... NEGATIVELY TILTED MID/UPPER LEVEL SHORTWAVE TROUGH OVER SRN CA AT THIS TIME IS EXPECTED TO LIFT NEWD INTO WY/CO BY START OF THE DAY2 PERIOD. FROM THERE...THE MAJORITY OF THE ENSEMBLE SOLUTIONS CLOSE MID/UPPER LOW OVER ERN SD BY TUESDAY EVENING WHILE HOLDING A SW-NE MID LEVEL RIDGE ACROSS THE SWRN AND S CENTRAL U.S. WITH THIS SOLUTION IN MIND...LOOKS LIKE MODELS ARE HAVING DIFFICULTY WITH LOCATION OF SURFACE LOW. SEEMS THAT IF MODELS SETTLE ON CLOSED LOW POSITION OVER ERN SD...THAT A LOW WILL DEVELOP THERE WITH A COLD FRONT MOVING EWD THRU CENTRAL PARTS OF NEB/KS INTO THE OK PANHANDLE. EXPECT LINE/CLUSTER OF SEVERE THUNDERSTORMS TO DEVELOP IN THE WARM SECTOR AHEAD OF THE LOW/COLD FRONT BY LATE AFTERNOON ACROSS CENTRAL/ERN SD INTO CENTRAL AND ERN NEB. ...PARTS OF THE NRN/CENTRAL PLAINS... AIR MASS IS EXPECTED TO DESTABILIZE WITH SBCAPE BETWEEN 2000-3000 J/KG FROM S CENTRAL ND SSEWD THRU THE MO VALLEY INTO NERN KS/NWRN MO BY LATE AFTERNOON. MODELS INDICATE 35-45 KT SLY LOW LEVEL JET BY EVENING THRU ERN KS INTO SERN SD ENHANCING LOW LEVEL MOISTURE CONVERGENCE AHEAD/NEAR REGION OF CYCLOGENESIS. APPROACHING TROUGH WILL BRING WLY TO SWLY 60 KT MID LEVEL FLOW INTO CENTRAL NEB BY EARLY AFTERNOON WITH 70-80 KT AT UPPER LEVELS. THIS IS EXPECTED TO PROVIDE SUFFICIENT DEEP LAYER SHEAR TO SUPPORT SUPERCELLS IN AREA OF STRONG UVVS ENHANCED BY UPPER LEVEL DIVERGENCE. ANALYSIS OF POINT FORECAST SOUNDINGS SHOW THAT AREAS OF SERN SD AND ERN NEB LOOK BEST FOR MAINLY LARGE HAIL AND THREAT FOR ISOLATED TORNADOES NEAR POINT WHERE SURFACE LOW WILL DEVELOP AND AHEAD OF ADVANCING FRONTAL BOUNDARY. MANY OF THE FORECAST DATA INDICATE STEEP LAPSE RATES BETWEEN 8-8.5C/KM AND MUCAPES AROUND 2200 J/KG. THIS DATA ALSO INDICATES 20-30 DEGREE T/TD SPREADS INDICATING ALSO THAT THE ACTIVITY MAY BE ACCOMPANIED BY DAMAGING WINDS. ..MCCARTHY.. 05/22/2006  From swody2 at goshenarc.org Tue May 23 05:07:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 23 May 2006 01:07:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230504 SWODY2 SPC AC 230503 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1203 AM CDT TUE MAY 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE MIDDLE MS VALLEY INTO SERN KS...OK AND NRN AR... ...SYNOPSIS... THE SHORTWAVE TROUGH CURRENTLY EJECTING NEWD INTO THE CNTRL ROCKIES WILL CREST THE MEAN RIDGE POSITION LATE TUESDAY THEN CONTINUE ESEWD THROUGH THE MIDDLE AND UPPER MS VALLEY WEDNESDAY. THIS FEATURE WILL MOVE INTO THE GREAT LAKES AND WRN PORTIONS OF THE OH VALLEY BY LATE WEDNESDAY NIGHT. EARLY WEDNESDAY AN OCCLUDED FRONT WILL EXTEND FROM A SURFACE LOW IN ND SEWD INTO WRN IA THEN SWWD AS A COLD FRONT THROUGH ERN KS AND NWRN OK. THIS FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH THROUGH THE MS VALLEY DURING THE DAY AND TRAIL SWWD THROUGH OK BY EARLY EVENING. A QUASISTATIONARY FRONT WILL PERSIST FROM THE SERN U.S. NWWD INTO THE MIDDLE MS VALLEY WHERE IT WILL INTERSECT THE COLD FRONT. ...MIDDLE MS VALLEY THROUGH SERN KS...OK AND NRN AR... RICHER LOW LEVEL MOISTURE NOW RESIDING NEAR QUASISTATIONARY FRONT OVER THE LOWER MS VALLEY INTO PARTS OF THE SRN PLAINS WILL SHIFT NEWD INTO THE MIDDLE MS VALLEY AS A SWLY LOW LEVEL JET STRENGTHENS W OF RETREATING SURFACE RIDGE. A BAND OF STRONGER 700-500 MB WLY FLOW ACCOMPANYING THE SHORTWAVE TROUGH WILL ADVECT STEEP MID LEVEL LAPSE RATES EWD THROUGH THE CNTRL/SRN PLAINS INTO THE MIDDLE MS VALLEY ABOVE THE MOIST AXIS. THIS SHOULD CONTRIBUTE TO MODERATE INSTABILITY AS THE BOUNDARY LAYER WARMS WITHIN THE PRE-FRONTAL WARM SECTOR FROM PARTS OF IA AND MO INTO SERN KS AND OK. A FEW STORMS MAY BE ONGOING EARLY WEDNESDAY WITHIN WARM ADVECTION REGIME OVER PART OF THE MIDDLE MS VALLEY. THESE STORMS WILL LIKELY CONTINUE SEWD AS THE LOW LEVEL JET VEERS. IF STORMS PERSIST INTO THE LATE MORNING OR AFTERNOON...IT IS POSSIBLE THAT THIS ACTIVITY COULD INTENSIFY AS IT INGESTS INCREASINGLY HIGHER THETA-E AIR FROM THE DESTABILIZING WARM SECTOR. OTHER STORMS WILL LIKELY DEVELOP ALONG THE COLD FRONT FROM PARTS OF MO SWWD INTO SERN KS AND OK. VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG OWING TO THE SOMEWHAT UNIDIRECTIONAL NATURE OF THE DEEP LAYER FLOW AND MODEST AMBIENT MID LEVEL FLOW. HOWEVER...THE 0-6 KM SHEAR MAY BECOME AT LEAST MARGINALLY SUFFICIENT FOR SUPERCELL STRUCTURES OVER PARTS OF MO INTO SERN KS AND OK WHERE A 40 KT WNWLY MID LEVEL JET WILL SPREAD SEWD ABOVE THE WSWLY LOW LEVEL FLOW. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS THROUGH MID EVENING. ACTIVITY WILL SPREAD EWD TOWARD THE OH AND TN VALLEYS DURING THE EVENING AND OVERNIGHT WITH A GRADUAL DECREASE IN SEVERE THREAT. ..DIAL.. 05/23/2006  From swody2 at goshenarc.org Tue May 23 17:06:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 23 May 2006 13:06:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231703 SWODY2 SPC AC 231702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 PM CDT TUE MAY 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS WED AFTN INTO THU MORNING ACROSS THE MID MS VALLEY INTO THE WRN OHIO VALLEY.... ...SYNOPSIS... PROGRESSIVE MID/UPPER LEVEL LOW WILL MOVE FROM THE ERN NRN PLAINS SEWD INTO THE SWRN UPPER GREAT LAKES DURING THE PERIOD AS STRONG VORTEX CURRENTLY NEAR 46N 138W SENDS SEVERAL SHORTWAVES NEWD ACROSS THE PACIFIC NORTHWEST. CONVECTION IS EXPECTED IN THE VICINITY OF MID/UPPER LOW AS WELL AS AHEAD OF THE FRONTAL BOUNDARY THAT WILL TRAVEL EWD EXTENDING FROM SERN ND SWD THROUGH ERN NEB THEN SWWD INTO THE OK PANHANDLE BY THE START OF THE PERIOD. REMNANTS OF AN MCS COULD BE OVER IA/NWRN MO TO BEGIN THE PERIOD WITH CONVECTIVE BOUNDARIES ACROSS ERN IA INTO NERN AND CENTRAL MO TO FOCUS LATER CONVECTIVE DEVELOPMENT. ...MID MS VALLEY INTO WRN OHIO VALLEY... MOIST AND UNSTABLE AIR MASS IS ALREADY IN PLACE FROM THE PLAINS INTO THE MO VALLEY AND WILL SPREAD EWD THROUGH THE EARLY PART OF THE PERIOD AS DAY1 CONVECTION AND FRONTAL BOUNDARY MOVES EWD TOWARDS THE MS VALLEY AND SURFACE RIDGE MOVES TOWARDS THE MID ATLANTIC REGION. SURFACE DEW POINTS ARE EXPECTED TO BE IN THE MID/UPPER 60S INTO MO/IL AND PARTS OF IND TOMORROW AS LOW LEVEL FLOW BEGINS AT 35-45 KT FROM CENTRAL OK NEWD INTO NWRN IL...THEN SHIFTS INTO THE MID MS VALLEY BY EVENING. 50-60 KT NWLY MID LEVEL FLOW WILL FOLLOW BEHIND MID/UPPER LEVEL LOW PROVIDING FAVORABLE DEEP LAYER SHEAR IN VICINITY OF STRONG LOW LEVEL CONVERGENCE TO SUPPORT SEVERE THUNDERSTORMS ALONG/AHEAD OF ADVANCING COLD FRONT ENHANCED BY OLD CONVECTIVE BOUNDARIES FROM PREVIOUS DAY CONVECTION. AIR MASS AHEAD OF COLD FRONTAL BOUNDARY IS EXPECTED TO DESTABILIZE WITH MUCAPES AROUND 3000 J/KG BY AFTERNOON ACROSS PARTS OF ERN IA/WRN IL/NERN MO. THUS...WOULD EXPECT SEVERE THUNDERSTORMS REDEVELOPING ACROSS THIS REGION WEDNESDAY AFTERNOON WITH MAIN THREATS BEING LARGE HAIL AND DAMAGING WINDS. GIVEN THAT DEEP LAYER SHEAR IS EXPECTED TO BE 30-40 KT...WOULD NOT RULE OUT A FEW ISOLATED TORNADOES IN THE VICINITY OF CONVECTIVE BOUNDARIES. SEVERE ACTIVITY IS EXPECTED TO BECOME MORE WIDESPREAD ACROSS PARTS OF MO/IL AND IND OVERNIGHT AS CONVECTION FORMS INTO ANOTHER MCS WITH MAIN THREAT BEING DAMAGING WINDS. ..MCCARTHY.. 05/23/2006  From swody2 at goshenarc.org Wed May 24 05:12:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 24 May 2006 01:12:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240509 SWODY2 SPC AC 240508 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1208 AM CDT WED MAY 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE OH VALLEY INTO THE TN AND LOWER MS VALLEYS... ...SYNOPSIS... UPPER LOW NOW OVER THE NRN PLAINS WILL CREST THE UPPER RIDGE AND CONTINUE SEWD THROUGH THE MID MS VALLEY INTO THE OH AND TN VALLEYS THURSDAY. ACCOMPANYING FRONT SHOULD EXTEND FROM A SURFACE LOW OVER THE WRN GREAT LAKES SWWD THROUGH MO INTO NWRN OK EARLY THURSDAY. THIS BOUNDARY WILL MOVE SEWD INTO THE OH VALLEY DURING THE DAY WITH TRAILING PORTION BECOMING STATIONARY ACROSS AR AND CNTRL OK THURSDAY NIGHT. ...OH AND TN VALLEYS THROUGH NRN AR AND SRN MO... LOW LEVEL FLOW WILL VEER TO WLY AS THE SHORTWAVE TROUGH ADVANCES ESEWD. THIS WILL CONTRIBUTE TO THE EWD ADVECTION OF RICHER BOUNDARY LAYER MOISTURE WITH LOW TO MID 60S DEWPOINTS INTO THE TN AND OH VALLEYS. AREAS OF PRE-FRONTAL CONVECTION MAY BE IN PROGRESS WITHIN PORTIONS OF THE WARM SECTOR EARLY THURSDAY AND WILL SPREAD SEWD DURING THE DAY. THE EVOLUTION OF THE EARLY ACTIVITY IS UNCERTAIN AT THIS TIME. HOWEVER...DESTABILIZATION IS EXPECTED WHERE CLEARING DEVELOPS IN THE WAKE OF THE MORNING STORMS WITH AN AXIS OF MLCAPE FROM 1500 TO 2000 J/KG JUST AHEAD OF THE FRONT. GIVEN HEIGHT FALLS ACCOMPANYING SEWD ADVANCING SHORTWAVE TROUGH AND WEAK CAP...STORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF THE FRONT FROM PARTS OF THE OH VALLEY SWWD INTO TN AND LOWER MS VALLEYS. KINEMATIC PROFILES ACCOMPANYING THE SHORTWAVE TROUGH WILL BE SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES INCLUDING BOWING LINE SEGMENTS AS WELL AS A FEW SUPERCELLS DURING THE AFTERNOON. SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING SUPPORTED BY AN INTENSIFYING LOW LEVEL JET. ..DIAL.. 05/24/2006  From swody2 at goshenarc.org Wed May 24 17:33:43 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 24 May 2006 13:33:43 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241730 SWODY2 SPC AC 241729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT WED MAY 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS... ...SYNOPSIS... SLOWLY PROGRESSIVE UPPER PATTERN IS FORECAST ACROSS THE NRN HALF OF THE CONUS...WITHIN ZONE OF STRONGER UPPER FLOW. UPPER LOW/SHORT-WAVE TROUGH INITIALLY FORECAST OVER THE MID/UPPER MS VALLEY REGION WILL MOVE ESEWD ACROSS THE GREAT LAKES/OH AND TN VALLEYS WITH TIME...ACCOMPANIED BY A CYCLONIC ARC OF MODERATELY-STRONG DEEP-LAYER FLOW. MEANWHILE...A SECOND UPPER LOW OFF THE BRITISH COLUMBIA COAST -- WITHIN LARGER-SCALE TROUGH -- IS FORECAST TO MOVE SEWD TOWARD THE PAC NW COAST WITH TIME...WHILE ACCOMPANYING UPPER JET SPREADS ACROSS THE PAC NW INTO THE NRN ROCKIES THROUGH THE PERIOD. ...OH/TN/MID MS VALLEY REGION... STORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF THE OH/TN VALLEY REGION...WITHIN ZONE OF LOW-LEVEL WARM ADVECTION AHEAD OF UPPER TROUGH. AS THIS CONVECTION SPREADS SEWD ACROSS THE OH/TN VALLEYS DURING THE DAY -- POSSIBLY ACCOMPANIED BY A LOW-END SEVERE THREAT...DAYTIME HEATING SHOULD ALLOW AIRMASS TO DESTABILIZE ACROSS THE MIDWEST IN THE WAKE OF INITIAL CONVECTION. AS UPPER FEATURE SHIFTS SEWD ALONG WITH ACCOMPANYING COLD FRONT...EXPECT NEW STORMS TO INITIATE DURING THE AFTERNOON -- LIKELY ACROSS THE MID OH VALLEY REGION INITIALLY. WITH SUFFICIENT INSTABILITY ANTICIPATED...EXPECT VIGOROUS UPDRAFTS...LIKELY EVOLVING INTO AN ORGANIZED/LINEAR MCS WITH TIME. GIVEN MODERATELY-STRONG/ROUGHLY UNIDIRECTIONAL FLOW THROUGH THE LOWER/MIDDLE TROPOSPHERE...POTENTIAL FOR AN ORGANIZED DAMAGING WIND EVENT APPEARS TO EXIST. WILL MAINTAIN ONLY A SLIGHT RISK THIS FORECAST AS SOME QUESTIONS REMAIN REGARDING DEGREE OF AIRMASS DESTABILIZATION IN THE WAKE OF INITIAL CONVECTION OVER THE THREAT AREA. AREA MAY BE UPGRADED IN LATER FORECASTS. ...MT/NWRN WY/SERN ID... STRONG SWLY FLOW ALOFT IS FORECAST ACROSS THIS AREA WITHIN TIGHT UPPER HEIGHT GRADIENT BETWEEN RIDGE OVER THE CENTRAL AND SRN ROCKIES AND APPROACHING UPPER LOW/TROUGH MOVING INTO THE PAC NW. DAYTIME HEATING SHOULD CONTRIBUTE MARGINAL/HIGH-BASED INSTABILITY ACROSS THIS REGION...WITH SURFACE LOW/FRONT LYING ACROSS THE AREA COMBINED WITH LARGE-SCALE UVV AHEAD OF APPROACHING TROUGH LIKELY SUPPORTING SCATTERED AFTERNOON STORM DEVELOPMENT. DESPITE LIMITED INSTABILITY...COMBINATION OF DEEP BOUNDARY LAYER AND STRENGTH OF DEEP-LAYER WIND FIELD SHOULD SUPPORT A THREAT FOR DAMAGING WIND GUSTS AND/OR HAIL WITH A FEW STRONGER CELLS. THREAT SHOULD DIMINISH THROUGH THE EVENING COINCIDENT WITH DIURNAL STABILIZATION. ..GOSS.. 05/24/2006  From swody2 at goshenarc.org Fri May 26 06:13:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 26 May 2006 02:13:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260610 SWODY2 SPC AC 260609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT FRI MAY 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN HIGH PLAINS EWD ACROSS ND INTO NRN MN... ...SYNOPSIS... MODELS CONTINUE TO SHOW THE UPPER PATTERN EVOLVING INTO A LONG WAVE TROUGH IN THE WEST AND A BUILDING RIDGE IN THE EAST. MID/UPPER LEVEL TROUGH...NOW LOCATED OVER THE GREAT LAKES/OH VALLEY...WILL MOVE EWD OFF THE ERN SEABOARD. A FEW MID LEVEL IMPULSES EMANATING FROM THE BASE OF THE WRN TROUGH ARE EXPECTED TO TRACK NEWD WITHIN BAND OF STRONG SWLY MID LEVEL FLOW ACROSS THE CENTRAL ROCKIES TO NRN PLAINS AND INTO SRN CANADA. IN THE LOW LEVELS...A SURFACE LOW LOCATED OVER WY AT 12Z SATURDAY IS EXPECTED TO TRACK ENE TOWARD THE WRN DAKOTAS BY LATE SATURDAY AFTERNOON AND MOVE ACROSS ND SATURDAY NIGHT. A BAROCLINIC ZONE WILL EXTEND NEWD FROM THE WY LOW ACROSS ND INTO SRN MANITOBA WITH THIS BOUNDARY REMAINING QUASISTATIONARY THROUGH DAY 2...AS A COLD FRONT SPREADS EWD FROM THE NRN HIGH PLAINS INTO ND/SD/NEB. A LEE TROUGH/ DRY LINE IS EXPECTED TO EXTEND SWD ALONG THE HIGH PLAINS. MEANWHILE...A SURFACE BOUNDARY IS PROGGED TO EXTEND FROM THE SE STATES NWWD ACROSS THE TN/MID MS VALLEY INTO IA...AND SHOULD BE THE FOCUS FOR SATURDAY AFTERNOON THUNDERSTORMS. ...PARTS OF NRN HIGH PLAINS EWD TO NRN MN... SLY LOW LEVEL FLOW EXPECTED ACROSS THE PLAINS STATES FROM DAY 1 INTO DAY 2 WILL ALLOW MOISTURE TO RETURN NWD INTO THE NORTH CENTRAL STATES WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S REACHING AS FAR NORTH AS MUCH OF ND/MN INTO ADJACENT PARTS OF SRN CANADA. ELEVATED MIXED LAYER IS EXPECTED TO SPREAD EWD INTO THE PLAINS ATOP THE MOISTURE RETURN...AND EFFECTIVELY CAP MUCH OF THE PLAINS STATES...LIMITING THUNDERSTORM DEVELOPMENT ALONG THE DRY LINE. HOWEVER...STEEP LAPSE RATES WILL RESULT IN STRONG INSTABILITY DEVELOPING FROM TX NWD TO THE NRN PLAINS/UPPER MS VALLEY...WITH THE GREATEST LIKELIHOOD FOR SEVERE THUNDERSTORM DEVELOPMENT FROM NRN MN WWD TO ERN MT/WY. A LEAD MID LEVEL IMPULSE EXPECTED TO BE LOCATED OVER THE ERN DAKOTAS AT 12Z SATURDAY WILL TRACK NEWD ACROSS NRN/CENTRAL MN... REACHING WRN ONTARIO BY SATURDAY EVENING. A MODERATE-STRONG SSWLY LLJ EXTENDING INTO ERN DAKOTAS/WRN MN AT START OF PERIOD SHOULD MAINTAIN ITS STRENGTH AND TRANSLATE NEWD ACROSS MN INTO ONTARIO. A THUNDERSTORM COMPLEX ASSOCIATED WITH THIS LEAD IMPULSE SHOULD BE ONGOING LATE DAY 1/EARLY DAY 2 AND TRACK NEWD ACROSS CENTRAL/NRN MN SATURDAY MORNING/AFTERNOON. INCREASING INSTABILITY/DEEP LAYER SHEAR WILL ALLOW FOR ORGANIZED STORMS/SOME SEVERE ESPECIALLY WITH ANY THAT CAN BECOME SURFACE BASED. ADDITIONAL STORM DEVELOPMENT IS POSSIBLE ACROSS ND ALONG THE SURFACE BOUNDARY...WITH A GREATER LIKELIHOOD FOR AFTERNOON STORMS FARTHER W ACROSS ERN MT INTO WY AS DEEP LAYER ASCENT INCREASES ACROSS THIS REGION AHEAD OF NEXT IMPULSE WITHIN UPSLOPE FLOW. MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS...WITH A SLY LLJ RE-INTENSIFYING ACROSS THE PLAINS SATURDAY NIGHT FOR UPSCALE GROWTH INTO AN MCS ACROSS ERN MT INTO ND. THIS ACTIVITY SHOULD BE MOVING INTO SRN CANADA TOWARD 12Z SUNDAY. ...PARTS OF W TX NWD TO WRN KS... ALTHOUGH MUCH OF THIS REGION IS EXPECTED TO BE CAPPED THROUGH SATURDAY AFTERNOON...STRONG SURFACE HEATING MAY ALLOW THE CAP TO WEAKEN ENOUGH FOR SURFACE PARCELS TO REACH THEIR LFC AT OR AFTER PEAK HEATING. WEAK MID LEVEL IMPULSES MOVING NEWD ACROSS THIS REGION COMBINED WITH STEEP LAPSE RATES/MODERATE INSTABILITY MAY PROVE SUFFICIENT FOR ISOLATED STORMS...WITH DEEP LAYER SHEAR AROUND 30 KTS FAVORING STORM ORGANIZATION. HAIL AND STRONG WIND GUSTS WOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. GIVEN ISOLATED COVERAGE...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES. ..PETERS.. 05/26/2006  From swody2 at goshenarc.org Fri May 26 17:51:10 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 26 May 2006 13:51:10 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261730 SWODY2 SPC AC 261729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI MAY 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...SYNOPSIS... UPPER AIR PATTERN WILL CONTINUE TO EVOLVE WITH A PROMINENT LONGWAVE TROUGH ACROSS THE WRN STATES AND A RIDGE IN THE EAST BY SAT. MINOR SHORTWAVE TROUGHS WILL EJECT NEWD FROM THE TROUGH AND INTO THE CNTRL/NRN PLAINS STATES. AT THE SFC...LEE LOW OVER WY WILL DEEPEN AND TRACK NEWD INTO CNTRL ND BY SAT NIGHT AS A BAROCLINIC ZONE SINKS SEWD FROM THE NRN ROCKIES INTO THE HIGH PLAINS. TO THE S OF THE LOW...A LEE TROUGH/DRYLINE WILL ADVANCE EWD INTO THE CNTRL/SRN PLAINS WHILE A WARM FRONT REDEVELOPS NEWD INTO THE UPPER MS VLY. MEANWHILE...AN OLD FRONT WILL REMAIN QUASISTATIONARY FROM THE MID-SOUTH INTO THE SERN STATES. ...NRN HIGH PLAINS EWD TO NRN MN... A COUPLE OF MCS/S WILL LIKELY BE ONGOING ACROSS THE MID-MO VLY AND OVER THE RED RVR VLY OF ERN ND/NWRN MN AT THE START OF THE PERIOD. STRONGEST LLJ AXIS WILL LIKELY MAINTAIN STORMS ALONG EDGE OF STRONG CAP OVER SRN MANITOBA AND NRN MN INTO SAT AFTN/EVE WITH RISKS FOR LARGE HAIL WHILE THE SRN MCS WEAKENS. UPSTREAM...A SURGE OF WARM TEMPERATURES ALOFT WILL CREATE A CAPPED ENVIRONMENT IN THE WARM SECTOR THROUGH SAT EVE. SFC-BASED TSTMS MAY INITIATE ACROSS CNTRL/NRN ND VCNTY SFC LOW TRACK AND COLD FRONT LATE SAT AFTN...BUT HIGHER PROBABILITIES WILL REMAIN ACROSS SRN CANADA. MORE LIKELY SCENARIO WILL BE FOR TSTMS TO DEVELOP OVERNIGHT ALONG/N OF THE COLD FRONT ACROSS THE NRN PLAINS AS THE UPPER TROUGH EDGES EWD. MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS. IF DAYTIME STORMS CAN MANAGE TO DEVELOP...DAMAGING WINDS AND TORNADOES WILL BE POSSIBLE. BUT...IF CONVECTIVE INITIATION IS DELAYED UNTIL OVERNIGHT N OF THE FRONT...LARGE HAIL WILL BE THE PRIMARY THREAT. ...CNTRL/SRN HIGH PLAINS... THOUGH MUCH OF THIS REGION IS EXPECTED TO BE CAPPED THROUGH SAT AFTN...STRONG SFC HEATING MAY ALLOW THE CAP TO WEAKEN ENOUGH FOR SFC PARCELS TO REACH THEIR LFC AFTN 22Z SAT. WEAK MID LEVEL IMPULSES MOVING NEWD ACROSS THIS REGION COMBINED WITH STEEP LAPSE RATES/MODERATE INSTABILITY MAY PROVE SUFFICIENT FOR ISOLD STORMS...WITH DEEP LAYER SHEAR AROUND 30 KTS FAVORING BRIEF STORM ORGANIZATION. HAIL AND STRONG WIND GUSTS WOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. GIVEN ISOLATED COVERAGE...ONLY LOW PROBABILITIES ARE JUSTIFIED ATTM. ...MID-SOUTH AND THE SERN STATES... SCT TSTMS ARE EXPECTED ALONG THE OLD FRONT FROM PARTS OF THE MID-SOUTH INTO THE SERN STATES SAT AFTN. WEAK SHEAR WILL FAVOR MULTI-CELL PULSE STORMS WITH PERHAPS ISOLD DAMAGING WIND GUSTS AND MARGINALLY SEVERE HAIL. ..RACY.. 05/26/2006  From swody2 at goshenarc.org Sat May 27 06:07:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 27 May 2006 02:07:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270606 SWODY2 SPC AC 270605 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0105 AM CDT SAT MAY 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...SYNOPSIS... MODELS TEND TO AGREE THAT THE SHORT WAVE TROUGH EXPECTED TO MOVE ESE INTO THE GREAT BASIN DURING DAY 1 PERIOD WILL TRACK NE TOWARD THE NRN HIGH PLAINS/SRN CANADA ON SUNDAY. HOWEVER...SOME DISCREPANCIES EXIST WITH THE AMOUNT OF HEIGHT FALLS /GFS AND ECMWF WEAKER/ WITH THIS SYSTEM AS IT APPROACHES THE NRN HIGH PLAINS/SRN CANADA LATE DAY 2. NONETHELESS...MID LEVEL HEIGHTS ARE EXPECTED TO TIGHTEN WITH RESULTANT STRENGTHENING OF SWLY WINDS AT THIS SAME LEVEL TO AT LEAST 70 KT ACROSS THE NRN PLAINS. IN THE LOW LEVELS...SURFACE TROUGH IS EXPECTED TO MOVE SLOWLY EWD ACROSS THE ERN DAKOTAS/CENTRAL NEB... WHILE A DRY LINE EXTENDING SWD MIXES EWD REACHING CENTRAL KS TO ALONG THE WRN OK/TX BORDER TO THE TX BIG BEND REGION BY SUNDAY AFTERNOON. FARTHER EAST...UPPER RIDGE WILL REMAIN IN PLACE OVER THE ERN U.S. WITH GENERALLY WEAK DEEP LAYER WIND FIELDS. ...NRN PLAINS... AIR MASS ALONG/E OF THE SURFACE TROUGH IS EXPECTED TO REMAIN MOIST AND VERY UNSTABLE WITH MLCAPE 2000-3000 J/KG...BUT STRONG ELEVATED MIXED LAYER WILL LIKELY MAINTAIN THE CAP OVER THE NRN PLAINS THROUGH THE AFTERNOON...LIMITING THE POTENTIAL FOR SURFACE-BASED STORMS. IF STORMS CAN DEVELOP SUNDAY AFTERNOON ALONG THE SURFACE BOUNDARY IN ND/SD...THEN STRONG DEEP LAYER SHEAR WOULD SUPPORT ORGANIZED STORMS/ SUPERCELLS. GREATER LIKELIHOOD FOR THUNDERSTORMS/ATTENDANT SEVERE THREAT SHOULD BE SUNDAY EVENING AS ASCENT INCREASES AHEAD OF APPROACHING GREAT BASIN TROUGH AND ALONG NOSE OF STRENGTHENING CENTRAL PLAINS LLJ. ACTIVITY WILL LIKELY BE LOCATED NORTH OF THE SURFACE BOUNDARY WITH HAIL BEING THE PRIMARY THREAT OVERNIGHT. THUNDERSTORMS WILL ALSO BE POSSIBLE SUNDAY AFTERNOON ALONG THE HIGHER TERRAIN OF ERN WY/NRN CO WITHIN UPSLOPE FLOW REGIME NORTH OF SURFACE BOUNDARY. INSTABILITY IS EXPECTED TO BE WEAK...THUS PRECLUDING A GREATER SEVERE RISK. HOWEVER...SOME OF THIS ACTIVITY MAY SPREAD ENE AND GROW UPSCALE INTO A CLUSTER OF STORMS TRACKING NEWD ACROSS NRN NEB/SD INTO ERN ND/WRN MN LATER SUNDAY NIGHT. ...SRN PLAINS... AIR MASS WILL BE MODERATELY TO VERY UNSTABLE SWD ALONG/E OF THE DRY LINE...BUT SHOULD REMAIN CAPPED UNTIL MID-LATE AFTERNOON. POINT FORECAST SOUNDINGS SUGGEST SURFACE HEATING SHOULD BECOME SUFFICIENT BETWEEN 20-23Z TO ALLOW SURFACE PARCELS TO REACH THEIR LFC. STEEP LAPSE RATES...MLCAPE UP TO 2500 J/KG AND DEEP LAYER SHEAR 25-30 KT SUGGEST POTENTIAL FOR ORGANIZED STORMS. HOWEVER... GIVEN MODEL UNCERTAINTY IN OVERALL STORM COVERAGE...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES INTRODUCED ON THE PREVIOUS DAY 3 OUTLOOK. ...OH VALLEY SWD TO GULF COAST STATES... THUNDERSTORMS WILL BE AGAIN POSSIBLE ALONG THE EXTENT OF THE SURFACE BOUNDARY FROM THE WRN GREAT LAKES SSEWD THROUGH THE LOWER OH/TN VALLEYS TO THE GULF COAST STATES SUNDAY AFTERNOON. MODERATE TO VERY STRONG INSTABILITY EXPECTED ACROSS THESE AREAS AND WEAK DEEP LAYER SHEAR SUGGESTS THE POTENTIAL FOR PULSE-TYPE STORMS. A FEW STORMS MAY BECOME CAPABLE OF PRODUCING A STRONG WIND GUST AND/OR MARGINALLY SEVERE HAIL...BUT WILL NOT INTRODUCE SEVERE PROBABILITIES AT THIS TIME. ..PETERS.. 05/27/2006  From swody2 at goshenarc.org Sat May 27 17:29:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 27 May 2006 13:29:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 271728 SWODY2 SPC AC 271727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SAT MAY 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN PLAINS... ...SYNOPSIS... BLOCKY UPPER FLOW REGIME WILL EXIST INTO MEMORIAL DAY AS A SPRAWLING UPPER HIGH BECOMES ESTABLISHED ACROSS THE ERN PORTIONS OF THE COUNTRY. THE WRN STATES TROUGH WILL GENERALLY REMAIN IN PLACE WITH THE STRONG SHORTWAVE TROUGH...NOW OVER NV...ROTATING NWD THROUGH THE NRN HIGH PLAINS BY EARLY MEMORIAL DAY. AT THE SFC...THE BAROCLINIC ZONE ASSOCD WITH THE WRN STATES TROUGH WILL EDGE EWD THROUGH THE NRN PLAINS...TRAILING SWWD INTO THE SRN GRT BASIN BY SUNDAY NIGHT. A SERIES OF LOWS WILL MIGRATE ALONG THIS FRONT WITH A DRYLINE TRAILING SWD THROUGH WRN KS...ERN TX PNHDL TO THE TX BIG BEND. ...NRN PLAINS... BOUNDARY LAYER MSTR WILL CONTINUE TO INCREASE THROUGHOUT THE PLAINS STATES BENEATH A STOUT ELEVATED MIXED LAYER THROUGH SUNDAY. THIS WILL CONTRIBUTE TO STRONG POTENTIAL INSTABILITY ALONG/AHEAD OF THE COLD FRONT/DRYLINE OVER THE CNTRL/ERN DAKS AND ERN NEB SUNDAY AFTN. CONFIDENCE IN SFC-BASED TSTM INITIATION IS LOW GIVEN MAGNITUDE OF INHIBITION. BUT...ALL MODELS INDICATE THAT WEAK HEIGHT FALLS WILL SPREAD NEWD FROM THE CNTRL ROCKIES INTO AT LEAST THE WRN DAKS SUNDAY EVE. THIS SHOULD ENHANCE A SFC LOW INVOF DRYLINE/COLD FRONT INTERSECTION DURING PEAK HEATING AND COULD BE THE IMPETUS FOR SFC-BASED INITIATION LATE SUNDAY AFTN OVER NCNTRL NEB OR SCNTRL/SERN SD. OTHERWISE...MORE LIKELY SCENARIO WILL BE FOR DEVELOPMENT OF POST-FRONTAL TSTMS THAT WILL TRANSLATE NEWD THROUGH THE RED RVR VLY OVERNIGHT SUNDAY. ORGANIZED STORMS WILL BE POSSIBLE. GIVEN SFC-BASED STORMS...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. BUT...THE STRONGER EFFECTIVE SHEAR WILL REMAIN ON THE COLD SIDE OF THE FRONT AND WILL SUPPORT MAINLY LARGE HAIL SUNDAY NIGHT. A LOWER PROBABILISTIC SEVERE THREAT WILL EXIST ALONG THE HIGHER WY/NRN CO HIGH PLAINS AS MOUNTAIN CONVECTION SPREADS NEWD. HERE...ISOLD DAMAGING WINDS OR HAIL MAY ACCOMPANY THE STRONGER STORMS AS THEY DEVELOP NEWD TOWARD THE NRN PLAINS MCS OVERNIGHT. ...SRN PLAINS... ISOLD TSTMS ARE EXPECTED TO DEVELOP INVOF DRYLINE FROM SWRN KS SWD ALONG THE CAPROCK/DRYLINE TO THE LOWER TRANS-PECOS REGION OF SWRN TX. STEEP LAPSE RATES...MLCAPE TO 2500 J/KG AND DEEP LAYER SHEAR 25-30 KT SUGGEST POTENTIAL FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. TSTMS WILL BE VERY SLOW MOVING AND LIKELY DIMINISH AS THE DRYLINE SLOSHES BACK WEST DURING THE EVENING. WILL MAINTAIN LOW PROBABILITIES ATTM...BUT FUTURE OTLKS MAY INTRODUCE SLGT RISK IF COVERAGE IS EXPECTED TO BE GREATER. ..RACY.. 05/27/2006  From swody2 at goshenarc.org Sun May 28 06:10:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 May 2006 02:10:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280608 SWODY2 SPC AC 280607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SUN MAY 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY SWD THROUGH PARTS OF THE CENTRAL/SRN PLAINS... ...SYNOPSIS... STRONG RIDGE IS EXPECTED TO REMAIN CENTERED FROM THE CENTRAL GULF COAST STATES NWD TO HUDSON BAY. HEIGHTS IN THE WEST WILL BEGIN TO RISE AS STRONG SHORT WAVE TROUGH PROGGED TO MOVE NEWD INTO THE NRN HIGH PLAINS AND ALBERTA/SASKATCHEWAN BY LATE DAY 1 CONTINUES TO TRACK NEWD INTO CENTRAL CANADA. ...UPPER MS VALLEY TO SRN PLAINS... SURFACE FRONT ASSOCIATED WITH THE CANADIAN SHORT WAVE TROUGH IS EXPECTED TO EXTEND FROM WRN MN SSWWD THROUGH ERN NEB TO THE OK/NRN TX PANHANDLES AT 12Z MONDAY. THIS BOUNDARY WILL MOVE EWD THROUGH THE PERIOD AND SHOULD EXTEND FROM ERN MN TO ERN KS INTO WRN OK/NW TX BY LATE MONDAY AFTERNOON /TOWARD 30/00Z/. DRY LINE IS EXPECTED TO EXTEND SWD FROM NWRN OK WHERE IT INTERSECTS COLD FRONT AND THEN TO THE TX BIG BEND REGION. ALTHOUGH THE UPPER TROUGH WILL BE MOVING NEWD INTO CANADA...THE ENTRANCE REGION OF A STRONG SWLY MID LEVEL JET ACCOMPANYING THIS SYSTEM IS EXPECTED TO PROVIDE FAVORABLE ASCENT FOR UPWARD VERTICAL MOTION ACROSS UPPER MS VALLEY INTO IA. THUNDERSTORM CLUSTER...POTENTIALLY SEVERE...IS EXPECTED TO BE ONGOING AT THE START OF DAY 2 ACROSS PARTS OF THE ERN DAKOTAS INTO WRN MN. THIS ACTIVITY SHOULD DECREASE IN INTENSITY MONDAY MORNING AS IT SPREADS ENE ACROSS MN...GIVEN A WEAKENING TREND IN THE LLJ ACROSS THIS AREA. STRONG SURFACE HEATING /UNSEASONABLY WARM TEMPERATURES MONDAY AFTERNOON/ EXPECTED TO PERSIST INTO DAY 2 PERIOD ALONG/E OF FRONT COMBINED WITH VERY MOIST AIR MASS AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT VERY STRONG INSTABILITY. ALTHOUGH STRONGER MID LEVEL WINDS ARE EXPECTED TO REMAIN ATOP THE POST-FRONTAL AIR MASS...AT LEAST 25-30 KT OF MID LEVEL FLOW SHOULD BE LOCATED FROM THE UPPER MS VALLEY SWD INTO ERN KS/NRN OK AIDING IN STORM ORGANIZATION. LARGE SCALE ASCENT WITHIN MID LEVEL JET ENTRANCE COMBINED WITH LOW LEVEL CONVERGENCE ALONG THE FRONT WILL ALLOW THUNDERSTORMS TO DEVELOP BY EARLY-MID AFTERNOON ACROSS MN WITH ACTIVITY DEVELOPING SWD ALONG THE FRONT INTO IA. GIVEN VERY STRONG INSTABILITY AND MODERATE DEEP LAYER SHEAR ORIENTED PARALLEL TO SURFACE BOUNDARY... STORM MODE SHOULD BE LINEAR WITH POTENTIAL FOR EMBEDDED SUPERCELLS WITHIN THE LINE OF ACTIVITY. POTENTIAL EXISTS FOR VERY LARGE HAIL WITH THE STRONGEST STORMS GIVEN THE DEGREE OF INSTABILITY FORECAST. THE STORMS OVER MN/IA WILL MOVE EWD INTO WI/NRN IL MONDAY EVENING...BUT SEVERE THREAT SHOULD DIMINISH WITH EWD EXTENT GIVEN DECREASING INSTABILITY MONDAY NIGHT. FARTHER S...THE LACK OF STRONGER UPPER FORCING SUGGESTS SURFACE HEATING WILL BE THE PRIMARY IMPETUS IN WEAKENING THE CAP FOR THUNDERSTORM DEVELOPMENT JUST AFTER PEAK HEATING ALONG THE FRONT AND DRY LINE IN KS/WRN OK INTO W TX. DEEP LAYER SHEAR IS EXPECTED TO BE SUFFICIENT /AROUND 25 KT/ FOR ORGANIZED STORMS...WITH LARGE HAIL AND DAMAGING WINDS BEING THE PRIMARY THREATS. MODELS SUGGEST THE POTENTIAL FOR ONE OR TWO MCS/S TO DEVELOP MONDAY NIGHT...WITH ONE OVER KS AND/OR OK AND THE SECOND ACROSS IA/NRN MO INTO WRN IL. THESE MCS/S WILL BE MAINTAINED BY STRENGTHENING NOCTURNAL SSWLY LLJ EXTENDING INTO THESE REGIONS COMBINED WITH SUFFICIENT EFFECTIVE BULK SHEAR/INSTABILITY FOR A CONTINUED SEVERE POTENTIAL OVERNIGHT. ...WRN NEW ENGLAND/CENTRAL-ERN NY INTO NERN PA... MODELS TEND TO AGREE THAT AN MCS TOPPING THE RIDGE LATE DAY 1 ACROSS SERN ONTARIO/SRN QUEBEC SHOULD BE ENTERING THE U.S. IN UPSTATE NY/NRN VT TOWARD 12Z MONDAY. THIS CLUSTER OF STORMS SHOULD BE IN THE DECAYING PHASE MONDAY MORNING AS IT TRACKS SEWD ACROSS NEW ENGLAND. OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS MAY PROVIDE A FOCUS FOR AFTERNOON/EARLY EVENING THUNDERSTORMS ACROSS PARTS OF WRN NEW ENGLAND INTO ERN/CENTRAL NY AND NERN PA. AIR MASS ACROSS THESE REGIONS SHOULD BECOME MODERATELY UNSTABLE. THIS COMBINED WITH MODEST LAPSE RATES /AROUND 6.5 C/KM/ AND 30 KT OF NWLY MID LEVEL FLOW MAY ALLOW FOR A FEW STORMS TO PRODUCE MARGINALLY SEVERE HAIL AND/OR A STRONG WIND GUST. THUS...HAVE INTRODUCED A LOW SEVERE PROBABILITY /5%/. ..PETERS.. 05/28/2006  From swody2 at goshenarc.org Sun May 28 17:34:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 May 2006 13:34:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281733 SWODY2 SPC AC 281732 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CDT SUN MAY 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VLY SWD INTO THE CNTRL PLAINS... ...SYNOPSIS... UPPER TROUGH ACROSS THE WRN STATES IS EXPECTED TO LIFT NEWD...GLANCING OFF THE NWRN PERIPHERY OF STRONG SERN STATES RIDGE. AT THE SFC...FRONT WILL MOVE EWD ACROSS THE UPPER MS VLY AND SETTLE SWD THROUGH THE CNTRL PLAINS BY MON EVE. ...UPPER MS VALLEY TO CNTRL PLAINS... WARM ADVECTION DERIVED TSTM CLUSTERS /ISOLD SEVERE/ ARE EXPECTED TO BE MOVING NEWD THROUGH PARTS OF THE ERN DAKS AND WRN MN AT THE BEGINNING OF THE PERIOD. THESE STORMS SHOULD WEAKEN THROUGH THE MORNING AS THE LLJ BEGINS TO WEAKEN. AHEAD OF THE COLD FRONT...AIR MASS IS EXPECTED TO REMAIN POTENTIALLY VERY UNSTABLE AS SEASONABLY MOIST AND WARM BOUNDARY LAYER PERSISTS ACROSS THE CORN BELT INTO THE UPPER MS VLY. HEATING AND WEAK LARGE SCALE HEIGHT FALLS ALONG THE NWRN PERIPHERY OF THE UPPER RIDGE WILL PROBABLY WEAKEN CINH SUFFICIENTLY FOR TSTMS TO INITIATE ALONG THE PRIMARY FRONT AND CONVECTIVE BOUNDARIES MON AFTN ACROSS THE UPPER MS VLY. THOUGH UPPER SUPPORT IS QUITE WEAK FARTHER S...STRONGER HEATING MAY CONTRIBUTE TO WEAKENING CINH AS FAR SW AS KS. THUS...TSTMS MAY DEVELOP OR BACKBUILD SWWD ACROSS THE CORN BELT...THE MID/LWR MO RVR VLY AND INTO KS LATE IN THE AFTN/EVE. STRONGER FLOW/EFFECTIVE VERTICAL SHEAR IS EXPECTED TO REMAIN ON THE COLD SIDE OF THE FRONT...BUT MAGNITUDE OF LAPSE RATES SUGGESTS ORGANIZED STORMS WILL BE POSSIBLE. ACTIVITY SHOULD DEVELOP INTO LINES ACROSS THE UPPER MS VLY AND CORN BELT...BUT MORE DISCRETE SUPERCELL STRUCTURES MAY BE POSSIBLE FARTHER SW. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREATS...WITH HAIL SIZE POSSIBLE EXCEEDING 2 INCHES ACROSS PARTS OF KS...SERN NEB INTO IA WHERE MID-LEVEL LAPSE RATES WILL BE STEEPER. ONE OR MORE MCS/S MAY EVOLVE OVERNIGHT MON...PRIMARILY ACROSS CNTRL/ERN KS AND ACROSS THE UPPER MS VLY. EWD EXTENT OF THE SEVERE THREAT APPEARS TO BE LIMITED AS SEASONABLY WARM TEMPERATURES ALOFT PERSIST WITHIN THE UPPER RIDGE AXIS. HIGHER PROBABILITIES FOR NOCTURNAL SEVERE WEATHER WILL BE ALONG WRN/SWRN FLANKS OF TSTMS CLUSTERS...NAMELY ACROSS PARTS OF IA...KS...MO AND PSBLY NERN OKLA WHERE HAIL WILL BE THE PRIMARY THREATS. ...WRN NEW ENGLAND/CENTRAL-ERN NY INTO NERN PA... MODELS ARE IN AGREEMENT THAT AN MCS TOPPING THE RIDGE LATE SUNDAY ACROSS SERN ONTARIO/SRN QUEBEC SHOULD BE ENTERING UPSTATE NY/NRN VT TOWARD 12Z MON. THIS CLUSTER OF STORMS SHOULD BE IN THE DECAYING PHASE MON MORNING AS IT TRACKS SEWD ACROSS NEW ENGLAND. OUTFLOW ENHANCED BACKDOOR COLD FRONT MAY PROVIDE A FOCUS FOR AFTN/EARLY EVE TSTMS ACROSS PARTS OF WRN NEW ENGLAND INTO ERN/CENTRAL NY AND NERN PA. AIR MASS ACROSS THESE REGIONS SHOULD BECOME MODERATELY UNSTABLE. THIS COMBINED WITH MODEST LAPSE RATES /AROUND 6.5 C/KM/ AND 30 KT OF NWLY MID LEVEL FLOW MAY ALLOW FOR A FEW STORMS TO PRODUCE MARGINALLY SEVERE HAIL AND/OR A STRONG WIND GUST. ..RACY.. 05/28/2006  From swody2 at goshenarc.org Mon May 29 06:16:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 May 2006 02:16:59 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290615 SWODY2 SPC AC 290614 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 AM CDT MON MAY 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN CO/FAR NERN NM EWD ACROSS SRN KS/WRN-NRN OK TO WRN MO... ...SYNOPSIS... MODELS CONTINUE TO INDICATE RISING HEIGHTS ACROSS THE WRN STATES ON TUESDAY AS A SHORT WAVE TROUGH...CURRENTLY MOVING ESEWD OVER NRN CA...TRACKS FROM THE CENTRAL ROCKIES TO THE NORTH CENTRAL STATES DURING THE DAY 2 PERIOD. A STRONGER LEAD UPPER TROUGH AND ASSOCIATED SURFACE LOW ARE EXPECTED TO DEEPEN AS THEY TRACK NEWD ACROSS CENTRAL CANADA TOWARD HUDSON BAY. MEANWHILE...DOWNSTREAM RIDGE AXIS THAT HAS BEEN CENTERED OVER THE ERN U.S. IS PROGGED TO TRANSLATE EWD TO ALONG THE ERN SEABOARD BY 12Z WEDNESDAY. IN THE LOW LEVELS...SURFACE FRONT ASSOCIATED WITH CANADIAN STORM SYSTEM WILL MOVE EWD ACROSS ONTARIO AND NRN GREAT LAKES REGION. THE TRAILING PORTION OF THIS BOUNDARY ACROSS IA INTO SRN PLAINS WILL BE NEARLY PARALLEL TO FLOW ALOFT SUGGESTING POTENTIAL FOR LITTLE SWD MOVEMENT. ...CENTRAL HIGH PLAINS SEWD INTO KS/OK... AN MCS MAY BE ONGOING 12Z TUESDAY ACROSS PARTS OF WRN/CENTRAL KS ASSOCIATED WITH WAA REGIME ALONG NOSE OF 35-40 KT SLY LLJ. THIS ACTIVITY SHOULD TRACK EWD TUESDAY MORNING AND DIMINISH IN INTENSITY AS THE LLJ JET WEAKENS. ASSOCIATED OUTFLOW BOUNDARY WILL EITHER REINFORCE THE SURFACE FRONT ACROSS SRN KS INTO NWRN OK OR ACT AS A SECOND FOCI FOR AFTERNOON THUNDERSTORM INITIATION ACROSS KS. SURFACE HEATING IN THE WAKE OF THIS MORNING ACTIVITY COMBINED WITH A MOIST AIR MASS BENEATH STEEP LAPSE RATES ARE EXPECTED TO RESULT IN MODERATE INSTABILITY FROM ERN CO INTO SRN KS AND SWD THROUGH TX PANHANDLE/WRN OK ALONG DRY LINE INTO CENTRAL TX. THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ALONG THE SURFACE FRONT...OUTFLOW BOUNDARIES...DRY LINE AND ALSO WITHIN UPSLOPE FLOW REGIME ALONG THE CENTRAL HIGH PLAINS OF ERN CO NWD TO ERN WY. ALTHOUGH HEIGHT FALLS WILL GENERALLY BE NEGLIGIBLE ACROSS THIS REGION...MODERATE SWLY MID LEVEL FLOW ATOP ESELY LOW LEVEL WINDS WILL RESULT IN STRONG DEEP LAYER SHEAR FOR SUPERCELLS. GREATEST SEVERE THREAT IS EXPECTED FROM ERN CO SEWD INTO SRN KS... CENTRAL/WRN OK AND THE TX PANHANDLE WHERE INSTABILITY WILL BE THE STRONGEST. IN FACT...THE POTENTIAL EXISTS FOR VERY LARGE HAIL WITH THE STORMS THAT DEVELOP TUESDAY AFTERNOON FROM SWRN KS/WRN OK INTO THE NERN TX PANHANDLE. SLY LLJ WILL RE-INTENSIFY TUESDAY NIGHT SUPPORTING THE UPSCALE GROWTH OF THUNDERSTORMS ACROSS ERN CO AND/OR SRN KS/NRN OK WITH THIS ACTIVITY POTENTIALLY REMAINING SEVERE AS IT TRACKS ESEWD ACROSS THE SRN PLAINS TUESDAY NIGHT. ...MO NEWD TO CENTRAL GREAT LAKES REGION... SURFACE FRONT SHOULD REMAIN NEARLY STATIONARY ACROSS MUCH OF MO AS THE PORTION EXTENDING INTO THE GREAT LAKES REGION SHOULD MOVE SLOWLY E AND SE REACHING LOWER MI TO NRN IL INTO MO BY 12Z WEDNESDAY. THUNDERSTORMS MAY BE ONGOING ACROSS THE WRN GREAT LAKES REGION INTO IA/NRN MO AT 12Z TUESDAY. A MOIST AIR MASS LOCATED ALONG/S OF THE FRONT/AHEAD OF ONGOING ACTIVITY AND BENEATH 7-7.5 C/KM MID LEVEL LAPSE RATES IS EXPECTED TO BECOME MODERATELY UNSTABLE TUESDAY SUPPORTING ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT. STRONGER MID LEVEL FLOW IS EXPECTED TO BE OVER THE POST-FRONTAL AIR MASS WITH AT BEST MODEST FLOW ALONG THE SURFACE BOUNDARY. THUS... WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT STORM ORGANIZATION...WITH A FEW OF THE STRONGER STORMS POTENTIALLY SUPPORTING AN ISOLATED HAIL/STRONG WIND GUST THREAT GIVEN THE MODERATE INSTABILITY. SOME INCREASE IN SWLY LOW LEVEL FLOW INTO THE GREAT LAKES REGION TUESDAY NIGHT MAY SUSTAIN THUNDERSTORM ACTIVITY OVERNIGHT...BUT WEAKENING INSTABILITY SHOULD PRECLUDE A SEVERE THREAT. ...PARTS OF NRN/CENTRAL TX... DEEP LAYER SHEAR ALONG THE DRY LINE IS EXPECTED TO BE WEAK...BUT GIVEN THE POTENTIAL FOR MODERATE INSTABILITY...A FEW SEVERE STORMS WILL BE POSSIBLE WITH ACTIVITY WEAKENING TUESDAY NIGHT AS THE LOSS OF DAYTIME HEATING STABILIZES THE BOUNDARY LAYER. ..PETERS.. 05/29/2006  From swody2 at goshenarc.org Mon May 29 17:33:10 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 May 2006 13:33:10 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291731 SWODY2 SPC AC 291730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT MON MAY 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL/SRN HIGH PLAINS... ...SYNOPSIS... WRN U.S. UPPER TROUGH IS FORECAST TO DEAMPLIFY WITH TIME...AS UPPER LOW GETS SHUNTED NEWD ACROSS CANADA BY STRONG/PERSISTENT ERN U.S. RIDGE. BELT OF MODERATE SWLY/WSWLY FLOW AT MID-LEVELS SHOULD PERSIST ACROSS THE CENTRAL/NRN PLAINS AND INTO THE UPPER MS VALLEY AN SRN FRINGES OF FLATTENING TROUGH...BUT OVERALL FLOW FIELD SHOULD REMAIN RELATIVELY WEAK FOR THIS TIME OF YEAR. AT THE SURFACE...BAROCLINIC ZONE INITIALLY EXTENDING FROM THE UPPER GREAT LAKES REGION SWWD INTO THE SRN HIGH PLAINS SHOULD WEAKEN/BECOME MORE ILL-DEFINED WITH TIME. HOWEVER...THIS FEATURE SHOULD REMAIN A FOCUS FOR CONVECTIVE DEVELOPMENT THROUGH THE PERIOD. ...CENTRAL AND SRN HIGH PLAINS... SURFACE LOW IS FORECAST OVER NRN NM/THE OK AND TX PANHANDLE REGION...WITH LOW-LEVEL ELYS/SELYS RESULTING IN UPSLOPE FLOW ACROSS THE CENTRAL AND SRN HIGH PLAINS. MODELS SUGGEST THAT DAYTIME HEATING COMBINED WITH AMPLE BOUNDARY-LAYER MOISTURE SHOULD RESULT IN MODERATE DESTABILIZATION FROM ERN CO/WRN KS SWD ACROSS ERN NM/THE SOUTH PLAINS OF TX. CONVECTION MAY BE ONGOING EARLY IN THE PERIOD ACROSS PARTS OF THIS REGION...WITH A REDEVELOPMENT/INTENSIFICATION OF STORMS EXPECTED BY AFTERNOON AS AIRMASS DESTABILIZES -- BOTH IN UPSLOPE FLOW ACROSS THE HIGH PLAINS AND ALONG STATIONARY/WARM FRONT WHICH SHOULD EXTEND W-E FROM AFOREMENTIONED SURFACE LOW ACROSS NRN OK OR KS. WITH ZONE OF ENHANCED /30 TO 40 KT/ WLY/WSWLY FLOW AT MID-LEVELS ATOP LOW-LEVEL SELYS/ELYS...SHEAR SUPPORTIVE OF SUPERCELL STORMS SHOULD ALLOW DEVELOPING STORMS TO RAPIDLY INTENSIFY/BECOME SEVERE. ALONG WITH POTENTIAL FOR A COUPLE OF TORNADOES...VERY LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE ACROSS A FAIRLY SMALL AREA INCLUDING NERN NM...SERN CO...SWRN KS...NWRN OK...AND THE TX/OK PANHANDLES. STORMS SHOULD CONTINUE THROUGH THE EVENING/OVERNIGHT...AIDED BY INTENSIFYING LOW-LEVEL JET/WARM ADVECTION. STORMS MAY EVOLVE INTO AN MCS...AND MOVE SEWD/SSEWD ACROSS PARTS OF OK AND THE TX PANHANDLE INTO NWRN TX THROUGH THE END OF THE PERIOD...ACCOMPANIED BY AT LEAST A LOW-END SEVERE THREAT. ...UPPER GREAT LAKES REGION SWWD ACROSS THE MID MO VALLEY... MODERATE INSTABILITY BUT WEAK SHEAR IS FORECAST IN A SW-NE ZONE ALONG WEAKENING COLD FRONT. WIDESPREAD CONVECTION IS FORECAST ALONG/AHEAD OF THIS FRONT...BUT EXPECT OVERALL CONVECTIVE INTENSITY/ORGANIZATION TO REMAIN LIMITED BY WEAK SHEAR. NONETHELESS...DEGREE OF INSTABILITY SHOULD SUPPORT BRIEFLY SEVERE/PULSE-TYPE CONVECTION...WITH THE STRONGEST STORMS CAPABLE OF PRODUCING HAIL AND LOCALLY GUSTY WINDS. THREAT SHOULD DIMINISH AFTER SUNSET WITH THE ONSET OF DIURNAL COOLING/STABILIZATION. ...ERN WY INTO THE NEB PNHDL/WRN SD... THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE AFTERNOON -- IN UPSLOPE FLOW OVER ERN WY AND THE BLACK HILLS...AND ALONG WEAK/SECONDARY FRONT FORECAST TO BE LYING NE-SW ACROSS SD. THOUGH BOUNDARY LAYER MOISTURE -- AND THUS INSTABILITY -- SHOULD BE LIMITED /BELOW 500 J/KG MEAN-LAYER CAPE/...MID-LEVEL FLOW WILL CONTRIBUTE TO SHEAR SUFFICIENT FOR A FEW ORGANIZED STORMS. ALONG WITH A THREAT FOR HAIL WITH THESE STRONGER CELLS...LOCALLY GUSTY/DAMAGING WINDS MAY ALSO OCCUR GIVEN DEEP MIXED LAYER AND ASSOCIATED POTENTIAL FOR EVAPORATIVELY-DRIVEN DOWNDRAFTS. ..GOSS.. 05/29/2006  From swody2 at goshenarc.org Tue May 30 06:11:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 30 May 2006 02:11:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300610 SWODY2 SPC AC 300608 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT TUE MAY 30 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN HIGH PLAINS... ...SYNOPSIS... MODELS ARE IN GENERAL AGREEMENT WITH THE TIMING OF THE CURRENT WRN TROUGH WHICH SHOULD BE LOCATED OVER THE NRN HIGH PLAINS AT 12Z WEDNESDAY. THIS TROUGH SHOULD TRACK EWD TO THE UPPER MS VALLEY BY WEDNESDAY EVENING...AND THEN AMPLIFY SEWD INTO THE WRN GREAT LAKES/MID MS VALLEY IN RESPONSE TO HEIGHT RISES ACROSS MUCH OF WRN NORTH AMERICA. IN THE LOW LEVELS...A COLD FRONT EXTENDING FROM SRN ONTARIO AND SRN GREAT LAKES REGION SWWD TO OK AND TX PANHANDLE SHOULD MOVE SLOWLY SWD. THIS BOUNDARY...THOUGH WEAK...IS EXPECTED TO REMAIN A FOCUS FOR THUNDERSTORMS THROUGH THE DAY 2 FORECAST PERIOD. ...SRN HIGH PLAINS... COLD FRONT INITIALLY EXTENDING ACROSS OK INTO THE TX PANHANDLE AT 12Z WEDNESDAY IS EXPECTED TO MOVE SWD AND SHOULD REACH CENTRAL AND SW TX BY 12Z THURSDAY AS SURFACE HIGH PRESSURE BUILDS SWD ACROSS THE PLAINS. AT THE START OF DAY 2...ONE OR TWO MCS/S SHOULD BE ONGOING ACROSS MAINLY KS AND OK IN RESPONSE TO WAA ALONG THE NOSE OF A NOCTURNAL SLY LLJ EXTENDING FROM W TX INTO WRN KS. THIS ACTIVITY IS EXPECTED TO DIMINISH WEDNESDAY MORNING AS THE LLJ WEAKENS. STEEP MID LEVEL LAPSE RATES ARE PROGGED TO BE CONFINED TO CO/NM INTO W TX...WHERE COMBINED WITH SURFACE HEATING AND SURFACE DEWPOINTS IN THE UPPER 50S WILL RESULT IN MODERATE INSTABILITY FROM W TX/ERN NM INTO SERN CO. MOIST UPSLOPE FLOW INTO NM/CO IS EXPECTED TO AID THUNDERSTORM DEVELOPMENT WEDNESDAY AFTERNOON WITH ACTIVITY MOVING SEWD WITHIN WNWLY MID LEVEL FLOW. GIVEN THE WNWLY MID LEVEL FLOW ATOP ESELY LOW LEVEL WINDS...DEEP LAYER SHEAR WILL BE SUFFICIENT /30-40 KT/ FOR ORGANIZED STORMS. ACTIVITY WILL LIKELY BECOME SEVERE AS IT TRACKS SEWD INTO STRONGER INSTABILITY. CONTINUATION OF AFOREMENTIONED FLOW REGIME SHOULD SUPPORT THUNDERSTORMS... POTENTIALLY IN THE FORM OF CLUSTERS...SPREADING SEWD ACROSS SWRN KS AND INTO WRN OK/NW TX BY 12Z THURSDAY. THUNDERSTORMS SHOULD ALSO DEVELOP ALONG THE SWD MOVING COLD FRONT ACROSS OK AND PARTS OF NW TX...BUT THE COMBINATION OF WEAK MID LEVEL LAPSE RATES...MARGINAL INSTABILITY AND WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT THE SEVERE POTENTIAL WEDNESDAY AFTERNOON/ EVENING. ...PARTS OF ERN DAKOTAS INTO WRN MN... ONE OR TWO RESIDUAL SURFACE BOUNDARIES EXPECTED TO BE OVER THE DAKOTAS INTO SW MN/NRN IA WILL PROVIDE THE FOCUS FOR THUNDERSTORMS ON WEDNESDAY. STEEP MID LEVEL LAPSE RATES AND ASCENT SPREADING EWD ACROSS THIS REGION WITH THE UPPER TROUGH ARE EXPECTED TO AID IN THUNDERSTORM DEVELOPMENT WEDNESDAY AFTERNOON/EVENING. MODELS SUGGEST SURFACE DEWPOINTS IN THE LOWER 50S MAY ADVECT NWD INTO THIS AREA ON WEDNESDAY AIDING IN AT LEAST WEAK INSTABILITY FOR A FEW SEVERE STORMS GIVEN STRONG DEEP LAYER SHEAR. ...SRN GREAT LAKES REGION/OH VALLEY TO MID MS/LOWER MO VALLEYS... AIR MASS ALONG/S OF THE WEAK COLD FRONT IS EXPECTED TO REMAIN MOIST WITH SURFACE DEWPOINTS IN THE 60S. THIS COMBINED WITH SURFACE HEATING SHOULD RESULT IN MODERATE INSTABILITY. THUNDERSTORMS WILL LIKELY DEVELOP WITHIN THIS AIR MASS...BUT GENERALLY WEAK UPPER FORCING COMBINED WITH WEAK MID LEVEL LAPSE RATES SHOULD LIMIT THE NUMBER OF STORMS THAT CAN PRODUCE SUSTAINED UPDRAFTS. IN ADDITION...STRONGER MID LEVEL FLOW IS PROGGED TO REMAIN ON THE COLD SIDE OF THE FRONT RESULTING IN WEAK DEEP LAYER SHEAR...FURTHER INHIBITING THE POTENTIAL FOR STORM ORGANIZATION AND ATTENDANT SEVERE THREAT. ..PETERS.. 05/30/2006  From swody2 at goshenarc.org Tue May 30 17:33:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 30 May 2006 13:33:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301732 SWODY2 SPC AC 301731 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1231 PM CDT TUE MAY 30 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH PLAINS REGION... ...SYNOPSIS... ERN U.S. RIDGE ALOFT IS FORECAST TO WEAKEN THIS PERIOD...AS SHORT-WAVE TROUGH INITIALLY OVER THE NRN ROCKIES/NRN PLAINS SHIFTS SLOWLY EWD. MEANWHILE...FLOW ACROSS THE WRN HALF OF THE CONUS WILL AMPLIFY WITH TIME...AS RIDGE BUILDS ACROSS THE ROCKIES IN THE WAKE OF AFOREMENTIONED SHORT-WAVE TROUGH AND AHEAD OF LARGE UPPER LOW/TROUGH APPROACHING THE W COAST FROM THE ERN PACIFIC. AT THE SURFACE...COLD FRONT IS FORECAST TO MOVE EWD ACROSS THE GREAT LAKES REGION INTO NEW ENGLAND...WHILE SETTLING SWD ACROSS THE MIDWEST/OH VALLEY REGION. MEANWHILE...WEAKER/MORE SUBTLE AXIS OF SURFACE CONVERGENCE IS FORECAST TO MOVE SLOWLY SEWD ACROSS MN/SD/IA/NEB THROUGH THE PERIOD. ...CENTRAL AND SRN HIGH PLAINS... ELY/SELY LOW-LEVEL UPSLOPE FLOW INTO ERN PORTIONS OF CO/NM COMBINED WITH MARGINAL AFTERNOON INSTABILITY /500 TO 1000 J/KG MEAN-LAYER CAPE/ WILL RESULT IN CONVECTIVE DEVELOPMENT ALONG AND NEAR THE FRONT RANGE. WITH 20 TO 25 KT WLYS AT MID-LEVELS...DEGREE OF VEERING/SHEAR WILL LIKELY SUPPORT A THREAT FOR ORGANIZED/SUPERCELL STORMS ALONG WITH ASSOCIATED THREAT FOR HAIL/LOCALLY DAMAGING WINDS. STORMS SHOULD MOVE SEWD OFF THE HIGHER TERRAIN WITH TIME...AND LIKELY CONTINUE INTO THE OVERNIGHT HOURS AS LOW-LEVEL JET STRENGTHENS. THOUGH SEVERE THREAT SHOULD DIMINISH AFTER SUNSET...A LOW-END THREAT FOR SEVERE WEATHER MAY CONTINUE WELL INTO THE OVERNIGHT HOURS -- PARTICULARLY ACROSS ERN NM AND INTO ADJACENT PORTIONS OF TX AS LOW-LEVEL JET SHOULD BE STRONGEST ACROSS THIS AREA. ...WRN NEW ENGLAND/THE GREAT LAKES WSWWD ACROSS THE MIDWEST... WEAK DEEP-LAYER WIND FIELD BUT MODERATE INSTABILITY IS FORECAST AHEAD OF WEAK COLD FRONT MOVING EWD/SEWD ACROSS THE GREAT LAKES/OH VALLEY REGION. DESPITE THE OVERALL LACK OF SHEAR...DEGREE OF INSTABILITY WILL SUPPORT WIDESPREAD CONVECTION NEAR AND AHEAD OF FRONT. THOUGH STORMS SHOULD REMAIN GENERALLY PULSE IN NATURE...A FEW STRONGER/BRIEFLY INTENSE STORMS WILL LIKELY PRODUCE BRIEF GUSTY/DAMAGING WINDS AND/OR HAIL. THREAT SHOULD DIMINISH RAPIDLY AFTER SUNSET. ...NRN PLAINS/UPPER MS VALLEY REGION... THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE AFTERNOON INVOF WEAK SURFACE TROUGH/CONVERGENCE AXIS...AHEAD OF SHORT-WAVE TROUGH MOVING ACROSS THE NRN PLAINS. THOUGH INSTABILITY IS FORECAST TO BE WEAK /GENERALLY LESS THAN 500 J/KG MEAN-LAYER CAPE/...BAND OF ENHANCED /20 TO 30 KT/ FLOW AT MID-LEVELS AHEAD OF THE UPPER FEATURE MAY SUPPORT A FEW STRONGER/ORGANIZED CELLS CAPABLE OF PRODUCING MARGINAL HAIL/LOCALLY GUSTY WINDS. ANY SEVERE THREAT LINGERING INTO THE EVENING SHOULD DIMINISH AS AIRMASS STABILIZES. ..GOSS.. 05/30/2006  From SwoDy2 at goshenarc.org Thu May 4 06:03:16 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 02:03:16 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040600 SWODY2 SPC AC 040559 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CAROLINAS AND SE VA... ...SRN PLAINS/LOWER MS VALLEY... THE ZONAL FLOW PATTERN OVER THE ERN AND CNTRL U.S. WILL CONTINUE THROUGH FRIDAY AS A SHORTWAVE RIDGE AMPLIFIES SLIGHTLY OVER THE PLAINS AHEAD OF A SWRN U.S. TROUGH. AT THE SFC...A MOIST AXIS IS FORECAST TO BE IN PLACE ACROSS WRN AND CNTRL TX. SFC DEWPOINTS IN THE 50S F ALONG THIS AXIS SHOULD BE SUFFICIENT FOR MODERATE INSTABILITY ESPECIALLY ACROSS THE LOW-ROLLING PLAINS AND TX HILL COUNTRY BY MIDDAY FRIDAY. A LARGE MCS SHOULD BE ONGOING IN THE RED RIVER VALLEY WITH CLEARING PRESENT ACROSS THE LUBBOCK AND MIDLAND AREAS. THIS WILL BE THE MOST LIKELY LOCATION FOR STRONG THUNDERSTORM DEVELOPMENT IN THE AFTERNOON ALONG A FRONTAL BOUNDARY EXTENDING EWD ACROSS WCNTRL TX. STORM INITIATION WILL ALSO BE POSSIBLE FURTHER EAST ALONG THE BOUNDARY ACROSS NCNTRL TX AND THE LOWER MS VALLEY. SEVERAL MCS CLUSTERS APPEAR LIKELY TO DEVELOP AS STORMS INCREASE IN COVERAGE FRIDAY AFTERNOON AND EVENING. FRIDAY 21Z FORECAST SOUNDINGS SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES ACROSS TX WITH SHEAR PROFILES INCREASING SOME DURING THE DAY AS A SHORTWAVE TROUGH APPROACHES THE REGION FROM THE WEST. IN ADDITION...MID-LEVEL LAPSE RATES WILL STEEPEN AHEAD OF THE TROUGH. THIS COMBINED WITH THE INSTABILITY/SHEAR ENVIRONMENT SHOULD BE FAVORABLE FOR LARGE HAIL. A FEW OF THE STRONGER SUPERCELLS MAY ALSO BE CAPABLE OF PRODUCING A TORNADO AND VERY LARGE HAIL. ISOLATED WIND DAMAGE WILL ALSO BE LIKELY ESPECIALLY IN THE EVENING AS AN MCS ORGANIZES AND MOVES ESEWD INTO THE LOW-ROLLING PLAINS AND TX HILL COUNTRY. ...CAROLINAS... ZONAL FLOW WILL BE IN PLACE ACROSS THE ERN U.S. THROUGH FRIDAY AS A SFC LOW AND ASSOCIATED COLD FRONT MOVES SEWD INTO THE CNTRL APPALACHIANS AND CAROLINAS. SFC DEWPOINTS IN THE 50S F ALONG WITH SFC HEATING ACROSS THE REGION MAY BE SUFFICIENT FOR POCKETS OF MODERATE INSTABILITY SOUTH OF THE FRONT BY MIDDAY. AS A RESULT...THUNDERSTORM DEVELOPMENT APPEARS LIKELY IN THE AFTERNOON ALONG THE BOUNDARY IN THE SRN APPALACHIANS WITH ADDITIONAL STORMS INITIATING ON OR NEAR THE BOUNDARY ACROSS THE ATLANTIC COASTAL PLAINS. FORECAST SOUNDINGS FOR THIS AREA FRIDAY AFTERNOON SHOW MODERATE VERTICAL SHEAR WITH MLCAPE VALUES NEAR 1000 J/KG. ALTHOUGH LAPSE RATES WILL NOT BE PARTICULARLY STEEP...THE SHEAR AND INSTABILITY ENVIRONMENT SUGGESTS SUPERCELLS WILL BE POSSIBLE ESPECIALLY NEAR AREAS OF LOCALLY MAXIMIZED INSTABILITY. A THREAT OF LARGE HAIL AND ISOLATED WIND DAMAGE SHOULD BE GREATEST IN THE LATE AFTERNOON AND EARLY EVENING BEFORE STABILIZATION OCCURS DUE TO A LOSS OF SFC HEATING. ..BROYLES.. 05/04/2006  From SwoDy2 at goshenarc.org Thu May 4 17:14:56 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 13:14:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041712 SWODY2 SPC AC 041711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1211 PM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NM INTO PARTS OF THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL AND SRN PIEDMONT AND ATLANTIC COASTAL PLAIN... ...SYNOPSIS... AMPLIFIED...SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID-LEVEL TROUGH /CURRENTLY OVER CNTRL AND SRN CA/ WHICH WILL TRANSLATE EWD INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SOME UNCERTAINTY EXISTS WITH REGARD TO POSITION OF SYNOPTIC FRONT-OUTFLOW BOUNDARY COMPOSITE OVER TX. HOWEVER...IT DOES APPEAR THAT THIS BAROCLINIC ZONE WILL EXTEND GENERALLY FROM E-CNTRL NM SEWD THROUGH CNTRL TX INTO CNTRL LA BY FRIDAY AFTERNOON. ERN EXTENSION OF THIS FRONT WILL PUSH SEWD THROUGH THE TN VALLEY...CNTRL GULF COAST STATES AND CNTRL/SRN APPALACHIANS TO THE SERN ATLANTIC COAST THROUGH THE PERIOD. ...ERN NM / TX INTO THE LOWER MS VALLEY... 04/12Z OBSERVED SOUNDINGS ACROSS SRN TX INDICATE THAT LOW-LEVEL MOISTURE PROFILES HAVE IMPROVED OVER THE PAST 24 HOURS WITH MEAN MIXING RATIOS OF 13-14 G/KG. THIS MOISTURE WILL LIKELY REMAIN INTACT S OF COMPOSITE FRONTAL BOUNDARY...AND BENEATH STEEP MID-LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1500-2500 J/KG. STORMS ARE LIKELY TO BE ONGOING FRIDAY MORNING OVER PORTIONS OF NRN AND CNTRL TX NEAR OR N OF FRONTAL ZONE. THOUGH THIS ACTIVITY MAY UNDERGO SOME DIURNAL WEAKENING EARLY IN THE DAY...INTENSIFICATION IS EXPECTED BY AFTERNOON AS STORMS ENCOUNTER DESTABILIZING AIR MASS. POTENTIAL WILL EXIST FOR UPSCALE GROWTH INTO CLUSTERS OR A MCS WHICH WOULD MOVE SEWD INTO ERN/SERN TX AND LA FRIDAY AFTERNOON AND EVENING. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREATS. POTENTIAL FOR MORE SIGNIFICANT SEVERE STORMS IS EXPECTED BY AFTERNOON FARTHER TO THE W FROM ERN NM INTO WRN AND CNTRL TX AS HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH BEGIN TO OVERSPREAD WRN EXTENSION OF INSTABILITY AXIS. A BELT OF 40-50 KT WSWLY MID-LEVEL WINDS ARE FORECAST TO ACCOMPANY THIS TROUGH WITH VERTICAL SHEAR PROFILES BECOMING QUITE FAVORABLE FOR SUPERCELLS CAPABLE OF LARGE HAIL. TORNADO THREAT WILL BE LARGELY DEPENDENT ON MESOSCALE DETAILS...WITH THE BEST POTENTIAL WITH ANY MATURE SUPERCELLS INTERACTING FAVORABLY WITH PRE-EXISTING LOW-LEVEL BOUNDARIES. UPSCALE GROWTH INTO A MCS WILL LIKELY OCCUR FRIDAY NIGHT WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS SPREADING SEWD TOWARD THE TX COAST. ...SERN VA / CNTRL AND ERN NC / NERN SC... LATEST MODEL GUIDANCE CONTINUES TO INDICATE THAT INCREASING LOW-LEVEL MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS FRIDAY AFTERNOON AHEAD OF SURFACE FRONT WITH MLCAPES APPROACHING 1000-1500 J/KG. EXPECT THAT TSTMS WILL BECOME INCREASINGLY WIDESPREAD THROUGH THE AFTERNOON HOURS...WITH SOME POTENTIAL FOR A FEW ORGANIZED STORMS OWING TO MODEST DEEP-LAYER SHEAR /I.E. 25-30 KTS/ ON SRN PERIPHERY OF INTENSIFYING MID-LEVEL TROUGH OVER ERN CANADA INTO THE NERN STATES. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS THROUGH THE EVENING HOURS. THEREAFTER...STORMS SHOULD TEND TO WEAKEN WITH THE LOSS OF DAYTIME HEATING. ...MS / AL / GA... ADDITIONAL STORM CLUSTERS WILL LIKELY EVOLVE FRIDAY AFTERNOON ALONG AND S OF FRONTAL ZONE WITHIN MOIST AND MODERATELY UNSTABLE AIR MASS. MODEL GUIDANCE APPEARS TO HAVE PICKED UP ON MCV MOVING INTO THE ARKLATEX EARLY THIS AFTERNOON...WITH THIS FEATURE SLOWLY MOVING ESEWD ACROSS NRN AL INTO NRN GA AND SC THROUGH THE PERIOD. MORE CONCENTRATED TSTM ACTIVITY MAY OCCUR AHEAD OF THIS DISTURBANCE WITH THE POTENTIAL FOR MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THE PRIMARY FACTOR LIMITING A MORE ORGANIZED SEVERE THREAT APPEARS TO BE THE WEAK MID-LEVEL LAPSE RATES AND MARGINAL VERTICAL SHEAR. ..MEAD.. 05/04/2006  From SwoDy2 at goshenarc.org Thu May 4 17:32:58 2006 From: SwoDy2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 May 2006 13:32:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041730 SWODY2 SPC AC 041729 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT THU MAY 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NM INTO PARTS OF THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL AND SRN PIEDMONT AND ATLANTIC COASTAL PLAIN... CORRECTED FOR ERROR IN POINTS FILE ...SYNOPSIS... AMPLIFIED...SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FEATURE OF INTEREST BEING MID-LEVEL TROUGH /CURRENTLY OVER CNTRL AND SRN CA/ WHICH WILL TRANSLATE EWD INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SOME UNCERTAINTY EXISTS WITH REGARD TO POSITION OF SYNOPTIC FRONT-OUTFLOW BOUNDARY COMPOSITE OVER TX. HOWEVER...IT DOES APPEAR THAT THIS BAROCLINIC ZONE WILL EXTEND GENERALLY FROM E-CNTRL NM SEWD THROUGH CNTRL TX INTO CNTRL LA BY FRIDAY AFTERNOON. ERN EXTENSION OF THIS FRONT WILL PUSH SEWD THROUGH THE TN VALLEY...CNTRL GULF COAST STATES AND CNTRL/SRN APPALACHIANS TO THE SERN ATLANTIC COAST THROUGH THE PERIOD. ...ERN NM / TX INTO THE LOWER MS VALLEY... 04/12Z OBSERVED SOUNDINGS ACROSS SRN TX INDICATE THAT LOW-LEVEL MOISTURE PROFILES HAVE IMPROVED OVER THE PAST 24 HOURS WITH MEAN MIXING RATIOS OF 13-14 G/KG. THIS MOISTURE WILL LIKELY REMAIN INTACT S OF COMPOSITE FRONTAL BOUNDARY...AND BENEATH STEEP MID-LEVEL LAPSE RATES...CONTRIBUTING TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1500-2500 J/KG. STORMS ARE LIKELY TO BE ONGOING FRIDAY MORNING OVER PORTIONS OF NRN AND CNTRL TX NEAR OR N OF FRONTAL ZONE. THOUGH THIS ACTIVITY MAY UNDERGO SOME DIURNAL WEAKENING EARLY IN THE DAY...INTENSIFICATION IS EXPECTED BY AFTERNOON AS STORMS ENCOUNTER DESTABILIZING AIR MASS. POTENTIAL WILL EXIST FOR UPSCALE GROWTH INTO CLUSTERS OR A MCS WHICH WOULD MOVE SEWD INTO ERN/SERN TX AND LA FRIDAY AFTERNOON AND EVENING. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREATS. POTENTIAL FOR MORE SIGNIFICANT SEVERE STORMS IS EXPECTED BY AFTERNOON FARTHER TO THE W FROM ERN NM INTO WRN AND CNTRL TX AS HEIGHT FALLS ASSOCIATED WITH APPROACHING MID-LEVEL TROUGH BEGIN TO OVERSPREAD WRN EXTENSION OF INSTABILITY AXIS. A BELT OF 40-50 KT WSWLY MID-LEVEL WINDS ARE FORECAST TO ACCOMPANY THIS TROUGH WITH VERTICAL SHEAR PROFILES BECOMING QUITE FAVORABLE FOR SUPERCELLS CAPABLE OF LARGE HAIL. TORNADO THREAT WILL BE LARGELY DEPENDENT ON MESOSCALE DETAILS...WITH THE BEST POTENTIAL WITH ANY MATURE SUPERCELLS INTERACTING FAVORABLY WITH PRE-EXISTING LOW-LEVEL BOUNDARIES. UPSCALE GROWTH INTO A MCS WILL LIKELY OCCUR FRIDAY NIGHT WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS SPREADING SEWD TOWARD THE TX COAST. ...SERN VA / CNTRL AND ERN NC / NERN SC... LATEST MODEL GUIDANCE CONTINUES TO INDICATE THAT INCREASING LOW-LEVEL MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS FRIDAY AFTERNOON AHEAD OF SURFACE FRONT WITH MLCAPES APPROACHING 1000-1500 J/KG. EXPECT THAT TSTMS WILL BECOME INCREASINGLY WIDESPREAD THROUGH THE AFTERNOON HOURS...WITH SOME POTENTIAL FOR A FEW ORGANIZED STORMS OWING TO MODEST DEEP-LAYER SHEAR /I.E. 25-30 KTS/ ON SRN PERIPHERY OF INTENSIFYING MID-LEVEL TROUGH OVER ERN CANADA INTO THE NERN STATES. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS THROUGH THE EVENING HOURS. THEREAFTER...STORMS SHOULD TEND TO WEAKEN WITH THE LOSS OF DAYTIME HEATING. ...MS / AL / GA... ADDITIONAL STORM CLUSTERS WILL LIKELY EVOLVE FRIDAY AFTERNOON ALONG AND S OF FRONTAL ZONE WITHIN MOIST AND MODERATELY UNSTABLE AIR MASS. MODEL GUIDANCE APPEARS TO HAVE PICKED UP ON MCV MOVING INTO THE ARKLATEX EARLY THIS AFTERNOON...WITH THIS FEATURE SLOWLY MOVING ESEWD ACROSS NRN AL INTO NRN GA AND SC THROUGH THE PERIOD. MORE CONCENTRATED TSTM ACTIVITY MAY OCCUR AHEAD OF THIS DISTURBANCE WITH THE POTENTIAL FOR MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS. THE PRIMARY FACTOR LIMITING A MORE ORGANIZED SEVERE THREAT APPEARS TO BE THE WEAK MID-LEVEL LAPSE RATES AND MARGINAL VERTICAL SHEAR. ..MEAD.. 05/04/2006  From swody2 at goshenarc.org Fri May 5 06:01:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 May 2006 02:01:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050559 SWODY2 SPC AC 050558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI MAY 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CNTRL/ERN TX EWD INTO THE CNTRL GULF COASTAL AREA... ...CNTRL/ERN TX EWD TO THE CNTRL GULF COASTAL AREA... COMPLEX UPPER SYSTEM EJECTING SEWD FROM THE GRT BASIN WILL TRAVEL TO THE SRN PLAINS ON SATURDAY. A LEAD IMPULSE...NOW CROSSING THE DESERT SOUTHWEST...WILL LIKELY DRIVE AN MCS TO THE ERN TX/UPPER TX COAST FRI NIGHT INTO EARLY SATURDAY. IN ITS WAKE...ANOTHER IMPULSE CURRENTLY OVER NV...WILL ROTATE EWD INTO OK/NRN TX BY SATURDAY AFTERNOON. QUASI-STATIONARY FRONT EXPECTED TO LAY ACROSS THE LWR MS VLY WWD TO CNTRL TX LATER TODAY WILL LIKELY BE REINFORCED BY THE FRI NIGHT/EARLY SATURDAY MCS...PARTICULARLY OVER ERN TX AND THE LWR MS VLY. TAIL END OF THE FRONT MAY LIFT BACK NWD ACROSS CNTRL AND NRN TX SATURDAY AFTN AHEAD OF THE SECONDARY IMPULSE. IT IS UNCLEAR HOW UNSTABLE THE WARM SECTOR ACROSS THE LWR MS VLY WILL BECOME DOWNSTREAM OF THE OVERNIGHT MCS. LOW-LEVEL FLOW IS EXPECTED TO BE WEAK...BUT PRESENCE OF 60S BOUNDARY LAYER DEW POINTS AND 35-40 KTS OF MID-LEVEL FLOW SUGGESTS THAT A FEW STRONGER STORMS MAY DEVELOP SATURDAY AFTN/EVE FROM PARTS OF LA EWD TO SRN AL/WRN FL PNHDL. UPSTREAM...AIR MASS IS EXPECTED TO RECOVER WITH MID-UPPER 60S DEW POINTS LIKELY PRESENT ACROSS MOST OF CNTRL TX BY SATURDAY AFTERNOON. BOUNDARY LAYER IS EXPECTED TO WARM ALONG/AHEAD OF THE DRYLINE THAT SHOULD MIX EWD INTO THE WRN HILL COUNTRY AND S OF THE N TX BAROCLINIC ZONE. LOW-LEVEL FLOW IS EXPECTED TO REMAIN QUITE ANEMIC THROUGH THE DAY AS THE SECONDARY IMPULSE SWINGS EWD AND DEAMPLIFIES THROUGH N TX/OK. THE STRONGER MASS CONVERGENCE/HOTTEST BOUNDARY LAYER ACROSS CNTRL TX SHOULD CONTRIBUTE TO TSTM INITIATION BY EARLY-MID AFTN. THE STORMS SHOULD THEN DEVELOP MOVE ESEWD INTO ERN/SERN TX BY EVENING AND PERHAPS AS FAR EAST AS SRN LA BY 12Z SUNDAY. PRESENCE OF 40-50 KTS OF H5 FLOW AND STEEP MID-TROPOSPHERIC LAPSE RATES WILL BE FAVORABLE FOR SUPERCELLS EARLY IN THE LIFE CYCLE WITH LARGE HAIL AND POSSIBLY AN ISOLD TORNADO. ACTIVITY SHOULD EVOLVE INTO AN MCS OVERNIGHT ACCOMPANIED BY HIGH WINDS/HAIL... PRIMARILY ALONG SRN FLANKS OF THE MCS. ..RACY.. 05/05/2006  From swody2 at goshenarc.org Fri May 5 16:57:44 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 May 2006 12:57:44 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051655 SWODY2 SPC AC 051654 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1154 AM CDT FRI MAY 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL TX EWD TO THE CNTRL GULF COAST... ...SYNOPSIS... SPLIT FLOW REGIME WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH PRIMARY FOCUS FOR SEVERE TSTM DEVELOPMENT BEING SRN STREAM SHORT WAVE TROUGH WHICH WILL TRANSLATE EWD FROM THE SRN PLAINS INTO THE LOWER MS VALLEY. IN THE LOW-LEVELS...POSITION OF PRIMARY SYNOPTIC FRONT WILL LIKELY BE MODULATED BY CONVECTION THAT OCCURS DURING THE DAY ONE PERIOD. HOWEVER...IN GENERAL...THIS FEATURE SHOULD EXTEND INITIALLY FROM LOW PRESSURE OVER CNTRL TX ESEWD TO NEAR THE CNTRL GULF COAST. MAIN FRONTAL WAVE IS FORECAST TO DEVELOP EWD ALONG BAROCLINIC ZONE INTO W-CNTRL MS BY SUNDAY MORNING. AS THIS OCCURS...LEADING PORTION OF BOUNDARY WILL RETREAT NWD...WHILE TRAILING PART SURGES SEWD AS A COLD FRONT. ...CNTRL/ERN TX EWD TO THE CNTRL GULF COAST... NUMEROUS TSTM CLUSTERS ARE EXPECTED TO BE ONGOING SATURDAY MORNING FROM CNTRL AND ERN TX INTO PARTS OF THE LOWER MS VALLEY WITHIN REGION OF FORCING FOR ASCENT AHEAD OF APPROACHING SHORT WAVE TROUGH. INFLUX OF MOIST AND MODERATELY UNSTABLE AIR MASS OVER S TX INTO SRN LA WILL LIKELY MAINTAIN THESE STORMS THROUGH THE PERIOD NEAR OR JUST TO THE N OF SURFACE BOUNDARY WITH A THREAT OF DAMAGING WINDS AND LARGE HAIL. POTENTIALLY MORE INTENSE STORM DEVELOPMENT IS EXPECTED BY AFTERNOON ALONG SRN FRINGE OF ONGOING CONVECTIVE ACTIVITY NEAR OR S OF FRONTAL WAVE OVER CNTRL INTO ERN OR SERN TX. HERE...DEWPOINTS IN THE UPPER 60S TO LOWER 70S COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO MLCAPES OF 1000-2000 J/KG. THIS INSTABILITY IN CONJUNCTION WITH RELATIVELY STRONG LOW AND DEEP LAYER SHEAR SHOULD SUPPORT SUPERCELLS AND BOWING SEGMENTS WITH A THREAT OF DAMAGING WINDS...LARGE HAIL AND A FEW TORNADOES. THESE MORE INTENSE STORMS WILL MOVE/DEVELOP EWD OR SEWD INTO PORTIONS OF CNTRL/SRN LA SATURDAY NIGHT...PERHAPS AS FAR E AS SRN MS INTO SWRN AL. FARTHER TO THE N OVER CNTRL AND NRN MS...KINEMATIC ENVIRONMENT WILL BECOME INCREASINGLY FAVORABLE FOR SUPERCELLS OVERNIGHT. HOWEVER...THERE IS SOME UNCERTAINTY WITH REGARD TO THE NWD EXTENT OF AIR MASS DESTABILIZATION. ..MEAD.. 05/05/2006  From swody2 at goshenarc.org Sat May 6 06:02:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 May 2006 02:02:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060559 SWODY2 SPC AC 060558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SAT MAY 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL GULF COASTAL AREA INTO THE SERN STATES... ...CNTRL GULF COASTAL AREA/SERN STATES... UPPER FLOW REGIME WILL CONTINUE TO FAVOR AN ACTIVE SRN STREAM INTO SUNDAY. THE MID-LEVEL IMPULSE OBSERVED IN WATER VAPOR IMAGERY OVER THE SRN GRT BASIN EARLY SATURDAY MORNING IS EXPECTED TO MOVE ACROSS THE SRN PLAINS SATURDAY...THEN INTO THE SERN STATES BY SUNDAY NIGHT. THE SFC FRONT SITUATED FROM THE CAROLINAS SWWD ALONG THE GULF COAST SHOULD REMAIN ESSENTIALLY IN PLACE THROUGH SATURDAY. A WEAK LOW SHOULD FORM ALONG THE FRONT ACROSS THE LWR MS VLY BY 12Z SUNDAY... THEN TRACK ENEWD INTO THE LWR TN VLY BY EARLY MONDAY. TO THE EAST OF THE LOW...THE FRONT SHOULD GRADUALLY TRANSLATE NWD AS A WARM FRONT INTO CNTRL AL AND CNTRL GA SUNDAY AFTN...BUT LIKELY BE REINFORCED BY A WEDGE FRONT ALONG THE FOOT OF THE SRN APPALACHIANS. THERE WILL LIKELY BE WARM ADVECTION DERIVED RAIN/CLOUDS ALONG/N OF THE BAROCLINIC ZONE ACROSS THE LWR TN VLY AND SRN APPALACHIANS EARLY SUNDAY. IT IS NOT ENTIRELY CLEAR HOW UNSTABLE THE WARM SECTOR WILL BECOME S OF THE FRONT SUNDAY AFTN...BUT PRESENCE OF MID-UPPER 60S DEW POINTS AND POTENTIAL FOR HEATING...BOUNDARY LAYER SHOULD BECOME UNSTABLE GIVEN MODEST H5-H7 LAPSE RATES. LITTLE CAP AND FORCING FOR ASCENT ASSOCIATED WITH THE H5 IMPULSE WILL BE FAVORABLE FOR TSTMS TO FORM SUNDAY AFTN FROM SERN MS/ERN LA NEWD INTO CNTRL/SRN PARTS OF AL/GA. SUPERCELLS WILL BE POSSIBLE GIVEN 40+ KTS OF EFFECTIVE SHEAR WITH LARGE HAIL AND DAMAGING WIND GUSTS. TORNADOES WILL BE POSSIBLE...ESPECIALLY ACROSS CNTRL AL INTO SWRN GA ALONG THE WARM/WEDGE FRONT. HIGHER SEVERE PROBABILITIES MAY BE WARRANTED IN FUTURE OUTLOOKS...ONCE THE MAGNITUDE OF INSTABILITY BECOMES CLEARER. ...CNTRL/SRN HIGH PLAINS... MUCH OF THE SRN PLAINS IS EXPECTED TO RESIDE BENEATH LARGE SCALE RIDGING THROUGH MOST OF SUNDAY IN WAKE OF THE DISTURBANCE THAT WILL BE MOVING INTO THE DEEP SOUTH. BUT...A LOW-AMPLITUDE POSITIVE TILT SRN STREAM IMPULSE WILL APPROACH THE CNTRL/SRN HIGH PLAINS BY PEAK HEATING. RETURN FLOW WILL BRING MODEST MOISTURE NWWD INTO ERN NM AND ALONG A LEE-TROUGH NWD INTO WRN NEB. HEATING...WEAK ASCENT AND STEEP LAPSE RATES WILL BE FAVORABLE HIGH BASED TSTMS. VERTICAL SHEAR WILL REMAIN WEAK...BUT STRONGER STORMS WILL BE CAPABLE OF LARGE HAIL. ONE OR MORE WEAK MCS/S MAY EVOLVE SUNDAY NIGHT...MOVING EWD INTO NEB AND PARTS OF THE TX PNHDL. ...NRN PLAINS... FAST NRN STREAM FLOW IS EXPECTED TO CARRY SEVERAL DISTURBANCES EWD FROM THE N PAC BASIN EWD ACROSS THE INTERMOUNTAIN WEST AND INTO THE NRN PLAINS THROUGH SUNDAY. A NARROW RIBBON OF BOUNDARY LAYER MOISTURE WILL ADVECT NWD INTO THE ERN DAKS ALONG/EAST OF A LEE TROUGH AND BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES. AS LARGE SCALE ASCENT SPREADS EWD FROM AN UPSTREAM TROUGH...TSTMS WILL DEVELOP ALONG THE LEE-TROUGH AND ALONG THE APPROACHING COLD FRONT. VERTICAL SHEAR WILL BE SOMEWHAT WEAK...BUT GIVEN THE STEEP LAPSE RATES...ISOLD HAIL OR DAMAGING WINDS COULD OCCUR WITH THE STRONGER STORMS. ..RACY.. 05/06/2006  From swody2 at goshenarc.org Sat May 6 17:33:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 May 2006 13:33:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061729 SWODY2 SPC AC 061728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 PM CDT SAT MAY 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST TO THE SC/GA COASTS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...SYNOPSIS... PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD WITH SRN STREAM IMPULSE TRANSLATING EWD THROUGH THE TN VALLEY AND CNTRL GULF COAST TO THE CNTRL/SRN ATLANTIC COAST. MEANWHILE...NRN BRANCH SHORT WAVE TROUGH WILL SHIFT EWD FROM THE NRN AND CNTRL ROCKIES INTO THE HIGH PLAINS REGION SUNDAY AFTERNOON INTO EVENING...WHILE SRN STREAM POSITIVE TILT TROUGH MORE SLOWLY MOVES EWD THROUGH THE SRN ROCKIES INTO SRN HIGH PLAINS. IN THE LOW-LEVELS...SEVERAL FRONTAL WAVES WILL DEVELOP EWD ALONG BAROCLINIC ZONE FROM CNTRL MS/AL TO SRN SC...WITH PRIMARY SURFACE LOW CONSOLIDATING OVER SC NEWD INTO THE GULF STREAM SUNDAY NIGHT. TO THE W...LEE TROUGH WILL INTENSIFY OVER THE HIGH PLAINS WITH PACIFIC COLD FRONT EVENTUALLY OVERTAKING THIS FEATURE OVER THE WRN DAKOTAS INTO NEB SUNDAY AFTERNOON INTO EVENING. ...CNTRL GULF COAST NEWD THROUGH CNTRL/SRN GA INTO SRN SC... CLUSTERS OF TSTMS ARE EXPECTED TO BE ONGOING SUNDAY MORNING INVOF FRONTAL ZONE OVER THE CNTRL AND ERN GULF STATES WITH REGION OF LARGE-SCALE FORCING FOR ASCENT AHEAD OF SRN STREAM SHORT WAVE TROUGH. DESPITE RELATIVELY POOR LAPSE RATES...INFLUX OF A MOIST LOW-LEVEL AIR MASS SHOULD MAINTAIN THIS CONVECTION EWD TOWARD THE ATLANTIC COAST SUNDAY AFTERNOON INTO EVENING. PRIMARY UNCERTAINTY IS DEGREE OF INSTABILITY THAT WILL DEVELOP WITHIN THIS REGION OF STRONGER SYNOPTIC-SCALE FORCING AHEAD OF MAIN SHORT WAVE TROUGH GIVEN ANTICIPATED WIDESPREAD CLOUDS AND PRECIPITATION. IT APPEARS BETTER POTENTIAL FOR AIR MASS DESTABILIZATION WILL OCCUR ALONG SRN PERIPHERY OF CLOUD/PRECIPITATION SHIELD FROM ERN LA/SRN MS INTO CNTRL/SRN PORTIONS OF AL AND GA WHERE LOCALLY STRONGER DIABATIC HEATING COUPLED WITH DEWPOINTS IN THE 60S WILL CONTRIBUTE TO MLCAPES OF 1000-1500 J/KG. WHILE STRONGER FORCING MAY HAVE ALREADY SHIFTED E OF THE SRN APPALACHIANS...SUSTAINED LOW-LEVEL CONVERGENCE ALONG FRONT SHOULD BE SUFFICIENT TO SUPPORT ORGANIZED STORM DEVELOPMENT. LARGELY UNIDIRECTIONAL VERTICAL SHEAR OF 40-45 KTS SUGGESTS POTENTIAL FOR BOWING SEGMENTS OR SPLITTING SUPERCELLS CAPABLE OF LOCALLY DAMAGING WINDS...MARGINAL HAIL AND PERHAPS A COUPLE OF TORNADOES. CONDITIONAL SLIGHT RISK HAS BEEN EXTENDED EWD TO THE SC COAST GIVEN POTENTIAL FOR SOME DESTABILIZATION NEAR DEEPENING SURFACE LOW WHERE SHEAR PROFILES WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF A COUPLE TORNADOES AND DAMAGING WINDS. ...SWRN NEB SWD TO THE TX PNHDL... DESPITE STRENGTHENING SLY LOW-LEVEL FLOW AHEAD OF INTENSIFYING LEE TROUGH...BOUNDARY-LAYER MOISTURE WILL REMAIN LIMITED WITH DEWPOINTS IN THE MID 40S TO LOWER 50S. HOWEVER...STEEPENING LOW TO MID-LEVEL LAPSE RATES WILL LARGELY CONTRIBUTE TO AIR MASS DESTABILIZATION SUNDAY AFTERNOON WITH MLCAPES APPROACHING 1000 J/KG. INCREASED LARGE-SCALE FORCING ASSOCIATED WITH APPROACHING SHORT WAVE TROUGH COUPLED WITH DAYTIME HEATING AND CONVERGENCE ALONG LEE TROUGH WILL SUPPORT TSTM DEVELOPMENT BY LATE AFTERNOON FROM WRN NEB SWD THROUGH ERN CO/WRN KS INTO NERN NM AND THE TX PNHDL. INSPECTION OF FORECAST SOUNDINGS SUGGESTS THAT REGION DELINEATED BY HIGHER SEVERE PROBABILITIES AND CATEGORICAL SLIGHT RISK WILL HAVE AT LEAST MODEST DEEP-LAYER VERTICAL SHEAR /25-35 KTS/ WHICH WILL SUPPORT A FEW ORGANIZED SEVERE STORMS CAPABLE OF SEVERE HAIL AND DAMAGING WINDS. EVOLUTION INTO CLUSTERS OR AN MCS MAY OCCUR SUNDAY NIGHT OVER CNTRL KS INTO THE ERN TX PNHDL/WRN OK...THOUGH WEAKENING INSTABILITY WITH THE ONSET OF NOCTURNAL COOLING SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT FARTHER TO THE E. ...WRN/SWRN TX... BELT OF RELATIVELY STRONG MID AND HIGH-LEVEL FLOW WILL BE MAINTAINED ACROSS REGION IN ASSOCIATION WITH MORE ACTIVE SRN BRANCH OF WESTERLIES. PRIMARY UNCERTAINTY IS INITIATION OF DEEP CONVECTION OWING TO STRONGER CAP AND APPARENT LATER ARRIVAL OF NEXT UPSTREAM IMPULSE. SHOULD STORMS DEVELOP AND BECOME SUSTAINED ALONG LEE TROUGH OR WRN EXTENSION OF REMNANT STATIONARY BOUNDARY...THE MODERATELY STRONG DEEP-LAYER SHEAR AND MODEST INSTABILITY WOULD SUPPORT A THREAT OF ORGANIZED/ROTATING UPDRAFTS CAPABLE OF LARGE HAIL AND LOCALLY STRONG WINDS. AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...DAKOTAS... TSTMS ARE EXPECTED TO DEVELOP BY MID TO LATE AFTERNOON ALONG LEE TROUGH OR PACIFIC COLD FRONT WITHIN STEEP LAPSE RATES ENVIRONMENT CHARACTERIZED BY MLCAPES OF 500-1000 J/KG. A FEW OF THE STORMS WILL BE CAPABLE OF MARGINALLY SEVERE WIND/HAIL...BUT RELATIVELY WEAK VERTICAL SHEAR SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 05/06/2006  From swody2 at goshenarc.org Sun May 7 06:01:44 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 May 2006 02:01:44 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070558 SWODY2 SPC AC 070558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT SUN MAY 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL PLAINS AND LWR MO RVR VLY... ...SYNOPSIS... MAIN BELT OF THE POLAR VLYS WILL BEGIN TO STRENGTHEN EARLY NEXT WEEK AS A LARGE SCALE RIDGE BUILDS ACROSS THE N PAC BASIN AND FORCES A DOWNSTREAM TROUGH TO EVOLVE ACROSS THE NRN INTERMOUNTAIN WEST. THIS TROUGH/STRONGER FLOW WILL PROGRESS TO THE NRN/CNTRL PLAINS BY MON NIGHT. DOWNSTREAM...A SPLIT FLOW REGIME WILL CONTINUE WITH SEVERAL SRN STREAM DISTURBANCES TRANSLATING ACROSS THE SRN PLAINS AND DEEP S. AT THE SFC...WRN END OF A WEAK FRONT ALONG THE GULF COAST WILL BEGIN TO REDEVELOP NWD THROUGH THE SRN PLAINS AHEAD OF THE WRN STATES TROUGH. LEE-TROUGH IN THE CNTRL/NRN PLAINS MON MORNING WILL EVENTUALLY BE OVERTAKEN BY A COLD FRONT BY MON NIGHT FROM THE ERN DAKS SWD INTO ERN NEB AND CNTRL KS. THIS FRONT WILL THEN MOVE SEWD TOWARD THE UPPER MS VLY AND SWD INTO THE SRN HIGH PLAINS BY 12Z TUE. ...CNTRL/NRN PLAINS... SLY LOW-LEVEL FLOW WILL ADVECT BOUNDARY LAYER MOISTURE NWD THROUGH THE PLAINS DURING THE NEXT COUPLE OF DAYS AHEAD OF THE DEVELOPING NRN STREAM TROUGH. BY MON AFTN...50S SFC DEW POINTS WILL BE COMMON AS FAR N AS THE ERN DAKS/WRN MN WITH 60S INTO THE LWR MO VLY/CNTRL PLAINS. HEATING ALONG/AHEAD OF THE LEE-TROUGH/COLD FRONT WILL CONTRIBUTE TO MODEST INSTABILITY WITH MLCAPES OF 500-1500 J/KG. AS LARGE SCALE ASCENT SPREADS SEWD AND THE COLD FRONT STRENGTHENS...TSTMS WILL LIKELY DEVELOP ACROSS WRN MN SWWD INTO SERN SD BY MID-AFTN. ACTIVITY WILL PROBABLY BACKBUILD SWWD INTO CNTRL/ERN NEB AND PARTS OF KS DURING THE EVENING. VERTICAL SHEAR WILL BE RATHER WEAK UNTIL EVENING WHEN IT IS EXPECTED TO INCREASE INTO THE 35-40 KT RANGE...SUFFICIENT FOR BRIEF SUPERCELL STRUCTURES. ACTIVITY WILL PROBABLY BECOME LINEAR QUICKLY AND MOVE TOWARD THE UPPER MS VLY AND CORN BELT OVERNIGHT...WITH DECREASING SEVERE RISKS. SRN END OF THE LINE MAY DEVELOP INTO A STRONGER MCS AND PROPAGATE SEWD INTO SRN KS AND NRN OK BY EARLY TUE WITH LOW HAIL PROBABILITIES. ...SRN PLAINS... AN MCS WILL LIKELY BE ONGOING EARLY IN THE PERIOD ACROSS OK AND ERN TX ALONG THE NOSE OF A 30-40 KT SLY LLJ. THIS MCS WILL PROBABLY MOVE EWD INTO THE OZARKS AND THE LWR MS VLY DURING THE DAY AND WEAKEN. IN WAKE OF THIS MCS...SUBSIDENCE AND LARGE SCALE RIDGING/WARMING ALOFT WILL LIKELY SUPPRESS CONVECTIVE CHANCES ALONG THE WARM FRONT/DRYLINE ACROSS CNTRL/NRN TX AND SWRN OK DURING MON AFTN. BUT...STRONG HEATING AND PERSISTENT/WEAK CONVERGENCE ALONG BOUNDARIES MAY BE SUFFICIENT FOR ISOLD TSTMS TO DEVELOP ACROSS PARTS OF CNTRL/NRN TX EWD INTO SWRN LA LATE MON AFTN. GIVEN A STORM...50 KTS OF EFFECTIVE SHEAR AND STEEP LAPSE RATES WILL BE FAVORABLE FOR PRIMARILY LARGE HAIL. ..RACY.. 05/07/2006  From swody2 at goshenarc.org Sun May 7 17:20:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 May 2006 13:20:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071718 SWODY2 SPC AC 071717 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 PM CDT SUN MAY 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE ARKLATEX... ...SYNOPSIS... MID-LEVEL TROUGH INITIALLY OVER THE CANADIAN AND NRN ROCKIES WILL INTENSIFY THROUGH THE FORECAST PERIOD AS IT TRANSLATES SEWD INTO THE NRN PLAINS ALONG CYCLONIC SIDE OF UPPER JET STREAK DIVING SEWD TOWARD THE CNTRL ROCKIES. MEANWHILE...SRN STREAM IMPULSE /INITIALLY OVER CNTRL KS INTO N-CNTRL TX/ WILL PROGRESS ESEWD TOWARD THE LOWER MS VALLEY. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH NRN PLAINS SHORT WAVE TROUGH WILL DEVELOP SEWD FROM CNTRL SASKATCHEWAN INTO SRN MANITOBA WITH TRAILING COLD FRONT LIKELY EXTENDING FROM THE RED RIVER VALLEY OF THE N SWWD INTO SWRN NEB BY LATE AFTERNOON. A LEE TROUGH OR DRY LINE WILL STRETCH SEWD FROM ITS INTERSECTION WITH COLD FRONT OVER SWRN NEB SWD THROUGH WRN OR CNTRL KS INTO WRN OK AND W-CNTRL TX. FARTHER SE...QUASI-STATIONARY BOUNDARY WILL EXTEND FROM NRN FL WWD ALONG THE GULF COAST...WITH WRN EXTENSION OF BOUNDARY RETREATING NWD THROUGH RED RIVER VALLEY OF THE S. ...NRN AND CNTRL PLAINS... DESPITE INCREASING SLY FLOW AHEAD OF COLD FRONT...LOW-LEVEL MOISTURE WILL REMAIN SOMEWHAT LIMITED WITH DEWPOINTS OF 45-55 F. HOWEVER...THE PRESENCE OF MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES WILL COMPENSATE TO SOME DEGREE FOR THE MARGINAL MOISTURE...WITH MLCAPES INCREASING TO 500-1500 J/KG. TSTMS WILL BECOME INCREASINGLY LIKELY BY AFTERNOON INITIALLY ALONG NRN EXTENSION OF COLD FRONT OVER THE ERN DAKOTAS/WRN MN WITH SUBSEQUENT DEVELOPMENT SWWD INTO CNTRL/ERN NEB BY LATE AFTERNOON OR EARLY EVENING. DEEP-LAYER SHEAR IS FORECAST TO BE MARGINALLY SUPPORTIVE /25-35 KTS/ OF ORGANIZED SEVERE STORMS WITH THE PRIMARY THREATS BEING SEVERE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONAL STORMS MAY ALSO DEVELOP SWD ALONG SRN PORTION OF COLD FRONT AND/OR LEE TROUGH/DRY LINE INTO KS LATE MONDAY AFTERNOON INTO EVENING. HERE TOO...DEEP-LAYER SHEAR WILL BE MARGINAL THOUGH LARGE HAIL/STRONG WINDS WILL REMAIN POSSIBLE WITH THE STRONGEST CELLS. ...SRN PLAINS INTO LOWER MS VALLEY... MORE UNCERTAINTY EXISTS ACROSS THIS REGION OWING TO POTENTIAL EFFECTS OF ONGOING STORMS MONDAY MORNING OVER OK INTO N TX AND TIMING OF WEAKER SRN STREAM IMPULSE. CLOSE PROXIMITY OF RICH BOUNDARY-LAYER MOISTURE /UPPER 60 TO LOWER 70S DEWPOINTS CURRENTLY OVER SERN TX/SRN LA/ SHOULD SUPPORT AIR MASS DESTABILIZATION /MLCAPES OF 1000-2000 J/KG/ ALONG AND S OF FRONTAL BOUNDARY WHICH WILL RETREAT NWD THROUGH THE SRN LOW PLAINS. AS MENTIONED ABOVE...STORM CLUSTERS OR AN MCS WILL LIKELY BE ONGOING OVER PORTIONS OF OK AND PERHAPS N TX MONDAY MORNING IN ADVANCE OF SRN STREAM IMPULSE. SOME DIURNAL WEAKENING MAY OCCUR THROUGH THE MORNING...WITH STORM RE-INTENSIFICATION OR NEW DEVELOPMENT ALONG SRN EDGE OF COLD POOL BY AFTERNOON OVER THE ARKLATEX. THE STRONGER FORCING FOR ASCENT ASSOCIATED WITH AFOREMENTIONED SHORT WAVE TROUGH WILL LIKELY HAVE SHIFTED E OF THE REGION BY THIS TIME...BUT MESOSCALE FORCING ALONG OUTFLOW BOUNDARY AND SYNOPTIC FRONT MAY BE SUFFICIENT TO MAINTAIN ANY DEVELOPING DEEP CONVECTION. SHOULD STORMS BECOME SUSTAINED...FORECAST VERTICAL SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS WITH 45-55 KTS OF DEEP-LAYER SHEAR AND 0-1 KM SRH OF 100-200 M2/S2. POTENTIAL WILL EXIST FOR LARGE HAIL...DAMAGING WINDS AND A FEW TORNADOES WITH THE MOST INTENSE STORMS. UNCERTAINTY IN DEVELOPMENT AND MAINTENENCE OF STORMS PRECLUDES HIGHER SEVERE PROBABILITIES. ..MEAD.. 05/07/2006  From swody2 at goshenarc.org Mon May 8 06:02:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 02:02:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080559 SWODY2 SPC AC 080558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS...THE MID MS VLY AND THE OZARKS... ...SYNOPSIS... A BROAD UPPER LEVEL TROUGH WILL CONTINUE TO PROGRESS EWD ACROSS THE COUNTRY ON TUE. NUMEROUS MID-LEVEL SHORTWAVE TROUGHS WILL BE EMBEDDED IN THE WNWLY FLOW REGIME...WITH THE STRONGEST TRANSLATING FROM THE NRN ROCKIES INTO THE UPPER MS VLY BY TUE NIGHT. A WEAKER JET STREAK WILL MIGRATE FROM THE GRT BASIN EARLY TUE TO THE CNTRL/SRN PLAINS TUE NIGHT. AT THE SFC...A MYRAID OF CONVECTIVE BOUNDARIES WILL BE IN PLACE EARLY TUE ACROSS THE CNTRL PORTIONS OF THE COUNTRY. MAIN SYNOPTIC FRONTS WILL INCLUDE A RETREATING WARM FRONT ACROSS SRN OK SEWD INTO THE DEEP SOUTH. A COLD FRONT WILL MOVE EWD INTO THE UPPER MS VLY...THEN SWWD INTO THE SRN HIGH PLAINS BY TUE NIGHT. A DRY LINE WILL MIX EWD INTO SRN OK SWWD INTO CNTRL TX. ...CNTRL/SRN PLAINS EWD INTO THE OZARKS... EVOLUTION OF TSTM CLUSTERS ACROSS THE PLAINS ON MON AND MON NIGHT WILL PLAY A ROLE IN THE SEVERE SCENARIOS TUE AND TUE NIGHT. THUS...CONFIDENCE IS LOWER THAN AVERAGE. IT APPEARS THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. COMPOSITE OUTFLOW BOUNDARY SHOULD REINFORCE THE RETREATING WARM FRONT FROM SRN OK SEWD INTO SRN AR. NRN PART OF THE MCS WILL PROBABLY WEAKEN AS IT MOVES BEYOND THE INSTABILITY AXIS...BUT THE LONGEVITY/SEVERITY OF THE SRN PORTION OF THE MCS IS NOT CLEAR. GIVEN THE SWLY LLJ FEEDING VERY UNSTABLE PARCELS INTO THE SWRN FLANK...IT IS CONCEIVABLE THAT STORMS MAY BACKBUILD MOST OF THE DAY ACROSS ERN OK AND WRN AR WITH THREATS FOR VERY LARGE HAIL. IF THE MCS WEAKENS...SFC DEW POINTS IN THE MID-UPPER 60S WILL LIKELY SURGE BETWEEN THE BUBBLE HIGH ACROSS THE OZARKS AND EAST OF A TRIPLE POINT LOW OVER CNTRL OK NWD TO THE SWD MOVING COLD FRONT IN SERN KS AND SWRN MO. H7-H5 LAPSE RATES AOA 8 DEG C PER KM AND HEATING WILL BOOST MLCAPES AOA 2500 J/KG IN THIS ZONE DURING PEAK HEATING. MOREOVER...ENELY UPSLOPE FLOW N OF THE COLD FRONT WILL MAINTAIN AT LEAST 50S DEW POINTS WWD INTO THE TX PNHDL/SWRN KS. THOUGH THERE MAY BE SOME SUBSIDENCE IN WAKE OF THE MCS AND EVIDENCE OF STRONG CINH ALONG/AHEAD OF THE TRIPLE POINT/ DRYLINE...FLOW ALOFT WILL BECOME MORE CYCLONIC BY EVENING AND RESULT IN ADDITIONAL TSTMS TO FORM...BOTH ALONG/N OF THE COLD FRONT FROM THE SRN HIGH PLAINS NEWD ACROSS SRN KS INTO PARTS OF MO...THEN SWD ALONG THE DRYLINE INTO OK. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL BE POSSIBLE...MAINLY ACROSS PARTS OF ERN OK...THOUGH THE SELY LOW-LEVEL FLOW MAY BE RATHER WEAK. FARTHER S...TSTMS WILL LIKELY BE MORE ISOLD ALONG THE DRYLINE INTO CNTRL TX. CINH IS EXPECTED TO BE RATHER STRONG AND THE UPPER FLOW REGIME SOMEWHAT ANTICYLONIC DURING MOST OF THE PEAK HEATING HOURS. BUT...THE BOUNDARY LAYER SHOULD BECOME RATHER HOT AND COULD ALLOW PARCELS TO BREECH THE CAP. SUPERCELLS WILL BE POSSIBLE AND A CONDITIONAL SLGT RISK WILL EXIST ALONG THE DRYLINE. SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY DOWNSTREAM FROM THE OZARKS INTO THE LWR MS VLY AND UPSTREAM FROM THE SRN HIGH PLAINS INTO OK/N TX. THESE STORMS MAY HAVE A NOCTURNAL THREAT FOR HAIL/HIGH WINDS. LASTLY...A WEAKER MCS MAY EVOLVE FROM PARTS OF ERN WY/CO INTO WRN NEB. ISOLD HAIL MAY OCCUR WITH THE STRONGER STORMS...MAINLY ACROSS CO. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING WITH RESPECT TO THE WARM SECTOR ORIENTATION...EVOLUTION INTO LINE SEGMENTS IS LIKELY EARLY IN THE TSTM LIFE CYCLES. ISOLD DAMAGING WINDS/HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT THE SEVERE THREAT SHOULD WANE DURING THE EVENING HOURS. ..RACY.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 06:02:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 02:02:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080559 SWODY2 SPC AC 080558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/SRN PLAINS...THE MID MS VLY AND THE OZARKS... ...SYNOPSIS... A BROAD UPPER LEVEL TROUGH WILL CONTINUE TO PROGRESS EWD ACROSS THE COUNTRY ON TUE. NUMEROUS MID-LEVEL SHORTWAVE TROUGHS WILL BE EMBEDDED IN THE WNWLY FLOW REGIME...WITH THE STRONGEST TRANSLATING FROM THE NRN ROCKIES INTO THE UPPER MS VLY BY TUE NIGHT. A WEAKER JET STREAK WILL MIGRATE FROM THE GRT BASIN EARLY TUE TO THE CNTRL/SRN PLAINS TUE NIGHT. AT THE SFC...A MYRAID OF CONVECTIVE BOUNDARIES WILL BE IN PLACE EARLY TUE ACROSS THE CNTRL PORTIONS OF THE COUNTRY. MAIN SYNOPTIC FRONTS WILL INCLUDE A RETREATING WARM FRONT ACROSS SRN OK SEWD INTO THE DEEP SOUTH. A COLD FRONT WILL MOVE EWD INTO THE UPPER MS VLY...THEN SWWD INTO THE SRN HIGH PLAINS BY TUE NIGHT. A DRY LINE WILL MIX EWD INTO SRN OK SWWD INTO CNTRL TX. ...CNTRL/SRN PLAINS EWD INTO THE OZARKS... EVOLUTION OF TSTM CLUSTERS ACROSS THE PLAINS ON MON AND MON NIGHT WILL PLAY A ROLE IN THE SEVERE SCENARIOS TUE AND TUE NIGHT. THUS...CONFIDENCE IS LOWER THAN AVERAGE. IT APPEARS THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. COMPOSITE OUTFLOW BOUNDARY SHOULD REINFORCE THE RETREATING WARM FRONT FROM SRN OK SEWD INTO SRN AR. NRN PART OF THE MCS WILL PROBABLY WEAKEN AS IT MOVES BEYOND THE INSTABILITY AXIS...BUT THE LONGEVITY/SEVERITY OF THE SRN PORTION OF THE MCS IS NOT CLEAR. GIVEN THE SWLY LLJ FEEDING VERY UNSTABLE PARCELS INTO THE SWRN FLANK...IT IS CONCEIVABLE THAT STORMS MAY BACKBUILD MOST OF THE DAY ACROSS ERN OK AND WRN AR WITH THREATS FOR VERY LARGE HAIL. IF THE MCS WEAKENS...SFC DEW POINTS IN THE MID-UPPER 60S WILL LIKELY SURGE BETWEEN THE BUBBLE HIGH ACROSS THE OZARKS AND EAST OF A TRIPLE POINT LOW OVER CNTRL OK NWD TO THE SWD MOVING COLD FRONT IN SERN KS AND SWRN MO. H7-H5 LAPSE RATES AOA 8 DEG C PER KM AND HEATING WILL BOOST MLCAPES AOA 2500 J/KG IN THIS ZONE DURING PEAK HEATING. MOREOVER...ENELY UPSLOPE FLOW N OF THE COLD FRONT WILL MAINTAIN AT LEAST 50S DEW POINTS WWD INTO THE TX PNHDL/SWRN KS. THOUGH THERE MAY BE SOME SUBSIDENCE IN WAKE OF THE MCS AND EVIDENCE OF STRONG CINH ALONG/AHEAD OF THE TRIPLE POINT/ DRYLINE...FLOW ALOFT WILL BECOME MORE CYCLONIC BY EVENING AND RESULT IN ADDITIONAL TSTMS TO FORM...BOTH ALONG/N OF THE COLD FRONT FROM THE SRN HIGH PLAINS NEWD ACROSS SRN KS INTO PARTS OF MO...THEN SWD ALONG THE DRYLINE INTO OK. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL BE POSSIBLE...MAINLY ACROSS PARTS OF ERN OK...THOUGH THE SELY LOW-LEVEL FLOW MAY BE RATHER WEAK. FARTHER S...TSTMS WILL LIKELY BE MORE ISOLD ALONG THE DRYLINE INTO CNTRL TX. CINH IS EXPECTED TO BE RATHER STRONG AND THE UPPER FLOW REGIME SOMEWHAT ANTICYLONIC DURING MOST OF THE PEAK HEATING HOURS. BUT...THE BOUNDARY LAYER SHOULD BECOME RATHER HOT AND COULD ALLOW PARCELS TO BREECH THE CAP. SUPERCELLS WILL BE POSSIBLE AND A CONDITIONAL SLGT RISK WILL EXIST ALONG THE DRYLINE. SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY DOWNSTREAM FROM THE OZARKS INTO THE LWR MS VLY AND UPSTREAM FROM THE SRN HIGH PLAINS INTO OK/N TX. THESE STORMS MAY HAVE A NOCTURNAL THREAT FOR HAIL/HIGH WINDS. LASTLY...A WEAKER MCS MAY EVOLVE FROM PARTS OF ERN WY/CO INTO WRN NEB. ISOLD HAIL MAY OCCUR WITH THE STRONGER STORMS...MAINLY ACROSS CO. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING WITH RESPECT TO THE WARM SECTOR ORIENTATION...EVOLUTION INTO LINE SEGMENTS IS LIKELY EARLY IN THE TSTM LIFE CYCLES. ISOLD DAMAGING WINDS/HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT THE SEVERE THREAT SHOULD WANE DURING THE EVENING HOURS. ..RACY.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 17:54:45 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 13:54:45 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081752 SWODY2 SPC AC 081751 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 PM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND ACROSS THE LOWER MS VALLEY... ...SYNOPSIS... AN ACTIVE SEVERE WEATHER PATTERN APPEARS TO BE SETTING UP FOR TUESDAY. DETAILS WITH REGARD TO WHERE GREATEST SEVERE POTENTIAL WILL EVOLVE ARE NOT YET CLEAR. HOWEVER...CHANCES FOR SEVERE STORMS SHOULD INCREASE FROM THE TX/OK PNHDLS EWD ACROSS THE OZARKS DURING THE DAY AND EVENING TUESDAY. A NRN BRANCH MID/UPPER LEVEL TROUGH WILL UNDERGO AMPLIFICATION ACROSS THE NRN AND CNTRL PLAINS THROUGH TUESDAY AS A NUMBER OF SMALLER SCALE PERTURBATIONS ROTATE THROUGH THE LARGE SCALE CYCLONIC FLOW FROM THE ROCKIES TO THE MS VALLEY. AT THE SURFACE...VARIOUS MCS OUTFLOW BOUNDARIES WILL BE INTERSPERSED WITH SYNOPTIC FRONTAL ZONES FROM THE SRN PLAINS/OZARKS NWD TO THE UPPER MS VALLEY. LATEST MODEL GUIDANCE WAS IN RELATIVELY GOOD AGREEMENT THAT ONE MCS WILL BE LOCATED OVER THE OZARKS EARLY TUESDAY WITHIN WARM CONVEYOR BELT AHEAD OF LEE-TROUGH AND SRN PLAINS COLD FRONT. ANOTHER MCS MAY BE ONGOING EARLY IN THE PERIOD ACROSS MN/WI NEAR A MID LEVEL SHORT WAVE TROUGH BEING EJECTED EWD AHEAD OF NEXT STRONG UPSTREAM SYSTEM DEVELOPING EAST FROM THE ROCKIES/HIGH PLAINS. SYNOPTIC FRONTS WILL ALSO INCLUDE A WARM FRONT EXTENDING FROM THE MCS OVER ERN OK/OZARKS SEWD TO THE DEEP SOUTH...AND A SECONDARY COLD FRONT ASSOCIATED WITH THE NRN BRANCH SYSTEM DEVELOPING SEWD ACROSS THE NRN/CNTRL PLAINS. LARGE SCALE HEIGHT FALLS AND DIFFERENTIAL HEATING WILL REINFORCE THE SRN PLAINS COLD FRONT FROM SERN CO TO THE NRN TX PNHDL AND INTO NWRN OK BY LATE AFTERNOON. MEANWHILE...DRYLINE WILL SHARPEN OVER THE ERN TX PNHDL AS TRIPLE POINT LOW EVOLVES ACROSS NWRN TX/SWRN OK. STRENGTHENING MESOSCALE FORCING ASSOCIATED WITH THESE FEATURES...COUPLED WITH INCREASING INSTABILITY AND SHEAR...SHOULD PROMOTE WIDESPREAD SEVERE TSTM ACTIVITY FROM THE SRN PLAINS TO THE LOWER MS VALLEY THROUGH TUESDAY NIGHT. ...SRN PLAINS/OZARKS EAST ACROSS THE LOWER MS VALLEY... MCS EVOLUTION ACROSS THE PLAINS THROUGH TUESDAY MORNING WILL PLAY A SIGNIFICANT ROLE IN SEVERE WEATHER FORMATION AND STORM MODE ACROSS PARTS OF OK AND AR LATER TUESDAY AFTERNOON. GIVEN THAT THE MCS HAS YET TO FORM...AND CONVECTIVE INHIBITION ACROSS THE WARM SECTOR MAY BE QUITE STRONG WITH 700MB TEMPERATURES AROUND 10C...A LOWER CONFIDENCE FORECAST SUGGESTS MAINTAINING ONLY A SLGT RISK AT THIS TIME. LATEST GUIDANCE DOES SUGGEST THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. OUTFLOW BOUNDARY SHOULD REINFORCE THE WARM FRONT ACROSS SRN OK SEWD ACROSS SRN AR. DESTABILIZATION AHEAD OF THE MCS...AND ALONG THE WARM FRONT TO THE TN VALLEY...COULD RESULT IN STRONG TO SEVERE STORMS CONTINUING... OR REDEVELOPING...EWD ACROSS THESE AREAS THROUGH THE DAY. DAMAGING WINDS...SOME HAIL...AND PERHAPS EVEN A TORNADO OR TWO COULD OCCUR WITH THIS ACTIVITY. THE SWRN FLANK OF THE MCS WILL PROBABLY WEAKEN AS CONVECTIVE INHIBITION STRENGTHENS ACROSS THE WARM SECTOR. HOWEVER...STRONG SWLY LLJ WILL CONTINUE TO TRANSPORT VERY UNSTABLE PARCELS ACROSS THE COLD POOL...AND CONVECTIVE CLUSTER WITH SOME HAIL POTENTIAL MAY PERSIST ACROSS PARTS OF AR DURING THE MORNING. SUBSIDENCE AND CAPPING IN WAKE OF THE MCS WILL ALLOW FOR THE DEVELOPMENT OF STRONG DESTABILIZATION ACROSS TX/OK THROUGH THE DAY WITH GREATEST CHANCE FOR STORM INITIATION OCCURRING BY AFTERNOON ALONG/NORTH OF REMNANT OUTFLOW...ACROSS WRN AR TO NRN OK. A SECONDARY AREA FOR STORM DEVELOPMENT SHOULD EVOLVE NEAR THE COLD FRONT/DRYLINE TRIPLE POINT...OR NORTH OF THESE FEATURES WHERE INCREASING LARGE SCALE FORCING FROM AMPLIFYING FLOW/HEIGHT FALLS WILL OVERCOME INHIBITION. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...MAINLY ACROSS PARTS OF NRN/ERN OK AND PERHAPS WRN AR...WHERE POST-OUTFLOW/FRONT ELY FLOW WILL RESULT IN ENLARGED HODOGRAPHS. FARTHER SOUTH ALONG ADVANCING DRYLINE...TSTMS WILL LIKELY BE MORE ISOLATED GIVEN STRONG CAP AND WEAKER LARGE SCALE FORCING. EXPECT SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY FROM THE OZARKS INTO THE LWR MS VLY...AND FROM THE SRN HIGH PLAINS ACROSS OK AND NRN TX. GIVEN AVAILABLE INSTABILITY FEEDING INTO THESE STORMS...THREAT FOR HAIL/HIGH WINDS MAY PERSIST WELL AFTER DARK AND INTO EARLY WEDNESDAY. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS IN THE 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING...EVOLUTION INTO LINE SEGMENTS IS LIKELY. A COUPLE OF DAMAGING WIND/HAIL EVENTS MAY ACCOMPANY THE STRONGER STORMS. EXPECT SEVERE THREAT TO WANE DURING THE EVENING HOURS. ..CARBIN.. 05/08/2006  From swody2 at goshenarc.org Mon May 8 20:31:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 May 2006 16:31:12 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 082027 SWODY2 SPC AC 082026 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0326 PM CDT MON MAY 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS AND ACROSS THE LOWER MS VALLEY... CORRECTED FOR NDFD PROBS ...SYNOPSIS... AN ACTIVE SEVERE WEATHER PATTERN APPEARS TO BE SETTING UP FOR TUESDAY. DETAILS WITH REGARD TO WHERE GREATEST SEVERE POTENTIAL WILL EVOLVE ARE NOT YET CLEAR. HOWEVER...CHANCES FOR SEVERE STORMS SHOULD INCREASE FROM THE TX/OK PNHDLS EWD ACROSS THE OZARKS DURING THE DAY AND EVENING TUESDAY. A NRN BRANCH MID/UPPER LEVEL TROUGH WILL UNDERGO AMPLIFICATION ACROSS THE NRN AND CNTRL PLAINS THROUGH TUESDAY AS A NUMBER OF SMALLER SCALE PERTURBATIONS ROTATE THROUGH THE LARGE SCALE CYCLONIC FLOW FROM THE ROCKIES TO THE MS VALLEY. AT THE SURFACE...VARIOUS MCS OUTFLOW BOUNDARIES WILL BE INTERSPERSED WITH SYNOPTIC FRONTAL ZONES FROM THE SRN PLAINS/OZARKS NWD TO THE UPPER MS VALLEY. LATEST MODEL GUIDANCE WAS IN RELATIVELY GOOD AGREEMENT THAT ONE MCS WILL BE LOCATED OVER THE OZARKS EARLY TUESDAY WITHIN WARM CONVEYOR BELT AHEAD OF LEE-TROUGH AND SRN PLAINS COLD FRONT. ANOTHER MCS MAY BE ONGOING EARLY IN THE PERIOD ACROSS MN/WI NEAR A MID LEVEL SHORT WAVE TROUGH BEING EJECTED EWD AHEAD OF NEXT STRONG UPSTREAM SYSTEM DEVELOPING EAST FROM THE ROCKIES/HIGH PLAINS. SYNOPTIC FRONTS WILL ALSO INCLUDE A WARM FRONT EXTENDING FROM THE MCS OVER ERN OK/OZARKS SEWD TO THE DEEP SOUTH...AND A SECONDARY COLD FRONT ASSOCIATED WITH THE NRN BRANCH SYSTEM DEVELOPING SEWD ACROSS THE NRN/CNTRL PLAINS. LARGE SCALE HEIGHT FALLS AND DIFFERENTIAL HEATING WILL REINFORCE THE SRN PLAINS COLD FRONT FROM SERN CO TO THE NRN TX PNHDL AND INTO NWRN OK BY LATE AFTERNOON. MEANWHILE...DRYLINE WILL SHARPEN OVER THE ERN TX PNHDL AS TRIPLE POINT LOW EVOLVES ACROSS NWRN TX/SWRN OK. STRENGTHENING MESOSCALE FORCING ASSOCIATED WITH THESE FEATURES...COUPLED WITH INCREASING INSTABILITY AND SHEAR...SHOULD PROMOTE WIDESPREAD SEVERE TSTM ACTIVITY FROM THE SRN PLAINS TO THE LOWER MS VALLEY THROUGH TUESDAY NIGHT. ...SRN PLAINS/OZARKS EAST ACROSS THE LOWER MS VALLEY... MCS EVOLUTION ACROSS THE PLAINS THROUGH TUESDAY MORNING WILL PLAY A SIGNIFICANT ROLE IN SEVERE WEATHER FORMATION AND STORM MODE ACROSS PARTS OF OK AND AR LATER TUESDAY AFTERNOON. GIVEN THAT THE MCS HAS YET TO FORM...AND CONVECTIVE INHIBITION ACROSS THE WARM SECTOR MAY BE QUITE STRONG WITH 700MB TEMPERATURES AROUND 10C...A LOWER CONFIDENCE FORECAST SUGGESTS MAINTAINING ONLY A SLGT RISK AT THIS TIME. LATEST GUIDANCE DOES SUGGEST THAT AN MCS OR TWO WILL BE ONGOING OVER THE MID-MS VLY SWWD INTO THE OZARKS. OUTFLOW BOUNDARY SHOULD REINFORCE THE WARM FRONT ACROSS SRN OK SEWD ACROSS SRN AR. DESTABILIZATION AHEAD OF THE MCS...AND ALONG THE WARM FRONT TO THE TN VALLEY...COULD RESULT IN STRONG TO SEVERE STORMS CONTINUING... OR REDEVELOPING...EWD ACROSS THESE AREAS THROUGH THE DAY. DAMAGING WINDS...SOME HAIL...AND PERHAPS EVEN A TORNADO OR TWO COULD OCCUR WITH THIS ACTIVITY. THE SWRN FLANK OF THE MCS WILL PROBABLY WEAKEN AS CONVECTIVE INHIBITION STRENGTHENS ACROSS THE WARM SECTOR. HOWEVER...STRONG SWLY LLJ WILL CONTINUE TO TRANSPORT VERY UNSTABLE PARCELS ACROSS THE COLD POOL...AND CONVECTIVE CLUSTER WITH SOME HAIL POTENTIAL MAY PERSIST ACROSS PARTS OF AR DURING THE MORNING. SUBSIDENCE AND CAPPING IN WAKE OF THE MCS WILL ALLOW FOR THE DEVELOPMENT OF STRONG DESTABILIZATION ACROSS TX/OK THROUGH THE DAY WITH GREATEST CHANCE FOR STORM INITIATION OCCURRING BY AFTERNOON ALONG/NORTH OF REMNANT OUTFLOW...ACROSS WRN AR TO NRN OK. A SECONDARY AREA FOR STORM DEVELOPMENT SHOULD EVOLVE NEAR THE COLD FRONT/DRYLINE TRIPLE POINT...OR NORTH OF THESE FEATURES WHERE INCREASING LARGE SCALE FORCING FROM AMPLIFYING FLOW/HEIGHT FALLS WILL OVERCOME INHIBITION. EFFECTIVE SHEAR WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS WITH VERY LARGE HAIL AND DAMAGING WINDS. TORNADOES WILL ALSO BE POSSIBLE...MAINLY ACROSS PARTS OF NRN/ERN OK AND PERHAPS WRN AR...WHERE POST-OUTFLOW/FRONT ELY FLOW WILL RESULT IN ENLARGED HODOGRAPHS. FARTHER SOUTH ALONG ADVANCING DRYLINE...TSTMS WILL LIKELY BE MORE ISOLATED GIVEN STRONG CAP AND WEAKER LARGE SCALE FORCING. EXPECT SEVERAL TSTMS CLUSTERS WILL GROW UPSCALE INTO MCS/S TUE NIGHT/EARLY WED...PROBABLY FROM THE OZARKS INTO THE LWR MS VLY...AND FROM THE SRN HIGH PLAINS ACROSS OK AND NRN TX. GIVEN AVAILABLE INSTABILITY FEEDING INTO THESE STORMS...THREAT FOR HAIL/HIGH WINDS MAY PERSIST WELL AFTER DARK AND INTO EARLY WEDNESDAY. ...UPPER MS VLY... IN WAKE OF MORNING CONVECTION...BOUNDARY LAYER SHOULD RECOVER ALONG/AHEAD OF THE COLD FRONT ACROSS PORTIONS OF THE UPPER MS VLY. RESIDUAL SFC DEW POINTS IN THE 50S BENEATH STEEPENING LAPSE RATES ALOFT ASSOCIATED WITH APPROACHING LARGE SCALE TROUGH WILL BE FAVORABLE FOR TSTM INITIATION ACROSS PORTIONS OF MN. VERTICAL SHEAR WILL BE WEAK AND GIVEN NATURE OF FORCING...EVOLUTION INTO LINE SEGMENTS IS LIKELY. A COUPLE OF DAMAGING WIND/HAIL EVENTS MAY ACCOMPANY THE STRONGER STORMS. EXPECT SEVERE THREAT TO WANE DURING THE EVENING HOURS. ..CARBIN.. 05/08/2006  From swody2 at goshenarc.org Tue May 9 17:48:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 09 May 2006 13:48:29 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091745 SWODY2 SPC AC 091744 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 PM CDT TUE MAY 09 2006 VALID 101200Z - 111200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM THE CONFLUENCE OF THE OH/MS RIVERS SWD ACROSS THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM SERN TX TO LOWER MI TO GA AND NRN FL... ...WIDESPREAD AND POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE APPEARS INCREASINGLY LIKELY OVER PARTS OF THE MS/TN VALLEYS AND LOWER OH VALLEY DURING WEDNESDAY... ...SYNOPSIS... MID/UPPER LEVEL FLOW OVER THE CNTRL U.S. WILL CONTINUE TO UNDERGO STRONG AMPLIFICATION THROUGH MIDWEEK AS LARGE SCALE PHASING BETWEEN MIDDLE AND NRN BRANCH FLOW PRODUCES AN ANOMALOUSLY DEEP CYCLONE ACROSS THE MIDWEST. THIS LARGE SCALE EVOLUTION WILL UNFOLD AS STRONG MIDDLE STREAM SHORT WAVE TROUGH DEVELOPS EAST ACROSS THE SRN PLAINS THROUGH LATE TUESDAY EVENING. THIS IMPULSE IS EXPECTED TO INDUCE STRONG MCS DEVELOPMENT ACROSS OK THROUGH TUESDAY NIGHT. SRN PLAINS SURFACE LOW IS FORECAST TO STRENGTHEN COINCIDENT WITH THE MCS AND SPREAD EAST TO NEAR THE MO BOOTHEEL AREA BY WEDNESDAY MORNING. SLOWER MOVING NRN BRANCH SHORT WAVE TROUGH/LOW WILL DEVELOP ESEWD FROM MT TOWARD THE UPPER MS VALLEY THROUGH WEDNESDAY AFTERNOON. STRONG COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SPREAD QUICKLY SWD/SEWD ACROSS THE PLAINS AND MERGE WITH THE DEEPENING CYCLONE ACROSS THE LOWER OH VALLEY DURING WEDNESDAY AFTERNOON. WHILE PRIMARY DEEP LAYER CYCLONE ASSOCIATED WITH THE NRN BRANCH TROUGH UNDERGOES OCCLUSION OVER LAKE MI...INTENSIFYING SECONDARY CYCLONE IS FORECAST TO TRACK NNEWD ACROSS THE MIDWEST... AND INTO LOWER MI...THROUGH WEDNESDAY EVENING. TRAILING COLD FRONT WILL SWEEP EWD ACROSS THE MID/LOWER MS VALLEY...AND ACROSS MUCH OF THE DEEP SOUTH AND OFF THE NCNTRL GULF COAST...THROUGH EARLY THURSDAY. ...SERN MO TO LOWER MI... POTENTIAL EXISTS FOR WIDESPREAD CLOUDS AND PRECIPITATION TO SOMEWHAT IMPEDE AIR MASS MODIFICATION ACROSS THE LOWER OH VALLEY DURING WEDNESDAY GIVEN PRESENCE OF UPSTREAM MCS ACTIVITY AND STRONG OUTFLOW BOUNDARIES. HOWEVER...GFS AND ENSEMBLE FORECASTS SUPPORT AT LEAST MODEST RECOVERY IN THE WAKE OF MORNING CONVECTION AND AHEAD OF APPROACHING MID LEVEL WIND MAX AND DEEPENING SURFACE LOW. GIVEN LOW TO MID 60S SURFACE DEWPOINTS AND POCKETS OF MLCAPE AROUND 500 J/KG /POSSIBLY HIGHER IF GFS FORECAST VERIFIES/ SHEAR AND FORCING APPEAR MORE THAN ADEQUATE TO PROMOTE STORM ORGANIZATION INTO LINE SEGMENTS AND LOW TOPPED SUPERCELLS. THIS ACTIVITY SHOULD SPREAD ENEWD ACROSS THE LOWER OH VALLEY AND LOWER MI FROM AFTERNOON THROUGH EVENING WITH AN INCREASING CHANCE FOR HAIL AND HIGH WINDS. TORNADO POTENTIAL APPEARS GREATEST NEAR THE INTENSIFYING SURFACE LOW. IF MODEST TO STRONG INSTABILITY CAN DEVELOP COINCIDENT WITH THIS FEATURE...A COUPLE OF STRONG TORNADOES APPEAR POSSIBLE. ...LOWER MS VALLEY/TN VALLEY/DEEP SOUTH... SOUTH OF THE SURFACE LOW...WIDESPREAD MOISTURE AND INCREASING INSTABILITY SHOULD EXIST. OUTFLOW FROM POSSIBLE OK/AR MCS MAY SPREAD SEWD INTO AND INHIBIT STRONGER AIR MASS DESTABILIZATION EARLY IN THE DAY. HOWEVER...STRONG RECOVERY IS EXPECTED IN THE WAKE OF THIS OUTFLOW...FROM TXK ACROSS THE LOWER MS VALLEY BY AFTERNOON. DIFFLUENT AND INCREASINGLY STRONG WLY MID LEVEL FLOW WILL SPREAD ACROSS THE RECOVERING WARM SECTOR AND FOSTER NEW CONVECTION AHEAD OF THE COLD FRONT FROM AR ACROSS THE MS RIVER. THIS ACTIVITY WILL EXIST WITHIN A STRONGLY SHEARED ENVIRONMENT AND NUMEROUS SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS APPEAR POSSIBLE. IF THIS CONVECTION CAN REMAIN DISCRETE THROUGH LATE AFTERNOON...STORMS WILL MOVE INTO HIGH HELICITY REGIME EXISTING IN THE WAKE OF EARLIER MCS OUTFLOW. TORNADIC STORMS APPEAR POSSIBLE BEFORE CONVECTION BECOMES INCREASINGLY LINEAR AS INTENSIFYING COLD FRONT DEVELOPS INTO THE REGION. WIND DAMAGE AND ISOLATED TORNADO THREAT MAY EXTEND BEYOND SUNSET AS SEVERE SQUALL LINE DEVELOPS ESEWD ACROSS THE NRN GULF COAST/DEEP SOUTH. ..CARBIN.. 05/09/2006  From swody2 at goshenarc.org Wed May 10 05:59:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 10 May 2006 01:59:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100556 SWODY2 SPC AC 100555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT WED MAY 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SERN VA INTO THE ERN CAROLINAS... ...SYNOPSIS... DEEP UPPER LOW IS EXPECTED TO EVOLVE OVER THE MIDWEST/GRTLKS REGION BY WED...THEN REMAIN IN PLACE INTO THU. A POTENT SHORTWAVE TROUGH...NOW DIGGING ACROSS THE NRN ROCKIES...WILL AMPLIFY AS IT ROTATES ALONG THE SRN PERIPHERY OF THE SYSTEM AND INTO THE SERN STATES THU AFTN. AT THE SFC...A LOW WILL MEANDER ACROSS NRN IND/SRN LWR MI ON THU WITH THE ATTENDANT COLD FRONT SWEEPING EWD TOWARD THE ATLANTIC SEABOARD. A SECONDARY LOW IS EXPECTED TO FORM IN THE SRN APPALACHIANS AND MOVE NEWD TOWARD NRN VA BY THU EVE WHILE A WARM FRONT LIFTS NWD TOWARD THE MASON-DIXON LINE. ...MID-ATLANTIC/ERN CAROLINAS... IT APPEARS THAT EARLY DAY CLOUDS/CONVECTION WITHIN A WARM CONVEYOR SHOULD MOVE OFF THE COAST BY MID-DAY THU...LEAVING MUCH OF THE SRN APPALACHIANS WITH THE POTENTIAL TO HEAT. SLY LOW-LEVEL FLOW SHOULD ADVECT LOWER-MID 60S SFC DEW POINTS NWD THROUGH THE COASTAL PLAINS OF THE CAROLINAS INTO SCNTRL/SERN VA. LAPSE RATES WILL TEND TO BE WEAK OWING TO RELATIVELY WARM TEMPERATURES IN THE H5-H7 LAYER. LATER IN THE AFTN...HOWEVER...STEEPER LAPSE RATES ALOFT SHOULD SPREAD ATOP THE MOIST AXIS AND GIVEN APPROACH OF 120 METER HEIGHT FALLS AND A 70-80 KT H5 JET AXIS...ENVIRONMENT COULD BECOME FAVORABLE FOR TSTMS TO DEVELOP VCNTY THE MOUNTAINS/FOOTHILLS BY MID-LATE AFTN. TSTMS WILL THEN MOVE NEWD ACROSS THE COASTAL PLAINS OF SERN VA AND THE ERN CAROLINAS BY EVENING. VERTICAL SHEAR OF 40-50 KTS WILL BE SUFFICIENT FOR ORGANIZED STORMS WITH HAIL...DAMAGING WINDS AND A TORNADO OR TWO. FARTHER S...LOW-LEVEL CONVERGENCE ALONG THE TRAILING FRONT BECOMES WEAK THROUGH THE AFTN. ISOLD TSTMS WILL BE POSSIBLE THE LENGTH OF THE FRONT INTO NRN/CNTRL FL AND DAMAGING WINDS MAY OCCUR. ...MIDWEST... MUCH UNCERTAINTY EXISTS WITH RESPECT TO THE MAGNITUDE OF CLOUD COVER BENEATH THE UPPER LOW. COLD POOL ALOFT /H5 TEMP AOA MINUS 20 DEG C/ WILL SHIFT EWD ACROSS THE MIDWEST ATOP MID-UPPER 40S SFC DEW POINTS. IF A ZONE OF STRONGER HEATING CAN OCCUR WITHIN ERN HALF OF THE UPPER LOW...A STRONGER STORM OR TWO MAY PRODUCE DAMAGING WINDS OR HAIL. ..RACY.. 05/10/2006  From swody2 at goshenarc.org Wed May 10 17:21:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 10 May 2006 13:21:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101718 SWODY2 SPC AC 101717 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 PM CDT WED MAY 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID ATLANTIC... ...SYNOPSIS... STRONG DEEP-LAYER CYCLONE WILL CONTINUE TO EVOLVE OVER THE UPPER MIDWEST/GREAT LAKES REGIONS THROUGH THURSDAY...AND THEN REMAIN ANCHORED OVER THESE AREAS AS A DEEP CLOSED LOW THROUGH THE END OF THE WEEK. THIS PROCESS WAS ALREADY UNDERWAY AS A VIGOROUS SHORT WAVE TROUGH...CURRENTLY CROSSING THE SRN PLAINS...PIVOTS RAPIDLY NEWD ACROSS THE MID MS VALLEY AND INDUCES STRONG CYCLOGENESIS OVER THE MIDWEST AND LOWER MI LATE TODAY THROUGH THURSDAY MORNING. ANOTHER POTENT UPSTREAM VORTICITY MAXIMUM...EVIDENT IN WATER VAPOR IMAGERY DIGGING SEWD ACROSS THE CNTRL PLAINS...WILL ROTATE THROUGH THE BASE OF THE LARGE SCALE LOW AND THEN ACROSS THE TN VALLEY ON THURSDAY AFTERNOON. STRONG HEIGHT FALLS ASSOCIATED WITH THIS SECONDARY SHORT WAVE FEATURE WILL SPREAD EWD/SEWD ACROSS THE SOUTHEAST...APPALACHIANS...AND MID ATLANTIC COASTAL PLAIN FROM THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. AS PRIMARY SURFACE CYCLONE UNDERGOES OCCLUSION OVER LOWER MI DURING THE DAY...ASSOCIATED COLD FRONT WILL SWEEP EAST ACROSS THE APPALACHIANS. GIVEN STRONG DYNAMIC FORCING ASSOCIATED WITH THE SECOND SHORT WAVE TROUGH APPROACHING THE APPALACHIANS...WEAK SECONDARY CYCLOGENESIS IS LIKELY TO OCCUR ON THE ADVANCING COLD FRONT IN THE LEE OF THE APPALACHIANS. THIS WAVE AND THE FRONT WILL THEN DEVELOP ENEWD ACROSS NRN VA THROUGH THE EVENING AS THE TRAILING PORTION OF THE COLD FRONT MOVES EWD AND OFF THE EAST COAST BY EARLY FRIDAY. ...MID-ATLANTIC/ERN CAROLINAS... WIDESPREAD CLOUDS AND CONVECTION ARE EXPECTED AT THE START OF THE PERIOD WITHIN EXTENSIVE WARM CONVEYOR BELT WHICH SHOULD MOVE EAST AND OFF THE COAST BY AFTERNOON. AT LEAST MODEST SURFACE HEATING SHOULD DEVELOP IN THE WAKE OF MORNING RAIN/CLOUDS BENEATH MID-LEVEL DRY SLOT FORECAST TO WRAP AROUND THE LARGER SCALE LOW FROM THE SRN APPALACHIANS TO WV/SWRN VA. WHILE MID LEVEL LAPSE RATES WITHIN THE DRY SLOT WILL TEND TO BE WEAK GIVEN RELATIVELY WARM TEMPERATURES IN THE H5-H7 LAYER...SURFACE HEATING AND DEWPOINTS IN THE 60S SHOULD CONTRIBUTE TO WEAK TO MODEST DESTABILIZATION AHEAD OF THE COLD FRONT. MIXING AND ASCENT ALONG THE FRONT SHOULD BE ENHANCED AS STRONG HEIGHT FALLS SPREAD EAST ATOP THE MOIST AXIS THROUGH THE LATE AFTERNOON. THIS SHOULD PROMOTE THE DEVELOPMENT OF A RELATIVELY LOW-TOPPED SQUALL LINE FROM SRN PA/NRN VA AREA SWD ACROSS PARTS OF THE CAROLINAS. DEEP LAYER VERTICAL SHEAR WILL STRENGTHEN COINCIDENT WITH THE DEVELOPING LINE OF STORMS AND SHOULD PROVE SUFFICIENT FOR STORM ORGANIZATION AND SUSTENANCE. SUPERCELLS AND LINE SEGMENTS SHOULD EVOLVE FROM THE FORCED LINE OF CONVECTION AND RESULT IN SCATTERED HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO OR TWO. FARTHER S...LOW-LEVEL CONVERGENCE AND DEEP SHEAR ALONG THE TRAILING FRONT BECOME WEAKER...FROM SRN SC SWD ACROSS FL. HOWEVER...FRONTAL CIRCULATION WILL MOVE INTO A VERY MOIST AND WEAKLY CAPPED ENVIRONMENT AND A FEW TSTMS ALONG THE LENGTH OF THE FRONT COULD PRODUCE ISOLATED DAMAGING WINDS AND/OR MARGINALLY SEVERE HAIL. ...SERN MO ACROSS THE TN VALLEY... MID LEVEL COLD POOL AND MODEST DYNAMIC FORCING ON CYCLONIC SHEAR SIDE OF MID LEVEL WIND MAX WILL FOSTER LOW-TOPPED CONVECTIVE DEVELOPMENT FROM THE MID MS VALLEY ESEWD ACROSS PARTS OF KY/TN DURING THE AFTERNOON. DESPITE LIMITED BOUNDARY LAYER MOISTURE IN THESE AREAS IN THE WAKE OF STRONG FRONTAL PASSAGE...SURFACE HEATING BENEATH COLD MID LEVEL TEMPERATURES AOB -20C WILL SUPPORT WEAK MLCAPE AND STEEP LOW THROUGH MID LEVEL LAPSE RATES. A FEW TSTM CLUSTERS FORMING WITHIN THIS REGION MAY PRODUCE HAIL. A SMALL SLGT RISK COULD BE INTRODUCED IN LATER OUTLOOKS IF IT APPEARS THAT HAIL STORM COVERAGE WARRANTS HIGHER PROBABILITIES. ..CARBIN.. 05/10/2006  From swody2 at goshenarc.org Fri May 12 06:05:32 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 May 2006 02:05:32 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120602 SWODY2 SPC AC 120601 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT FRI MAY 12 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER PATTERN TO REMAIN GENERALLY UNCHANGED THIS PERIOD...AS LARGE LOW/TROUGH REMAINS OVER THE ERN HALF OF THE CONUS...WHILE RIDGE PREVAILS ACROSS THE ROCKIES. AT THE SURFACE...HIGH PRESSURE OVER THE GULF OF MEXICO IS FORECAST TO WEAKEN WITH TIME...AS COLD FRONT MOVES SEWD ACROSS THE SRN PLAINS/SERN CONUS. ...SRN PLAINS EWD ACROSS THE SOUTHEAST... DIFFICULT FORECAST THIS PERIOD...WITH MODEL VARIABILITY LARGE ACROSS THE S CENTRAL AND SERN CONUS. ON THE LARGE SCALE...COLD FRONT WILL MOVE SWD/SEWD ACROSS THE REGION...THOUGH PREVIOUS FRONTAL PASSAGE INTO THE GULF SHOULD AFFECT THE QUALITY OF THE MOISTURE RETURN AHEAD OF THE SECOND FRONT -- PARTICULARLY ACROSS THE CENTRAL AND ERN GULF COAST REGION. THUS -- DESPITE MODEL FORECASTS OF A SHORT-WAVE TROUGH MOVING ACROSS THE SERN CONUS WITHIN FAST NWLY FLOW ALOFT...QUALITY OF AIRMASS REMAINS VERY QUESTIONABLE. LESS MODIFIED/MORE MOIST BOUNDARY LAYER AIRMASS WILL LIKELY RETURN ACROSS TX AND LA...BUT COMBINATION OF STRONGER CAP AND WEAKER FORCING LEAVES QUESTIONS REGARDING CONVECTIVE INITIATION ACROSS THIS REGION. SHOULD CAP WEAKEN ACROSS PARTS OF THE SRN PLAINS NEAR FRONT...AND SHOULD QUALITY OF MOISTURE RETURN INTO THE GULF COAST REGION RESULT IN SUFFICIENT INSTABILITY...A LARGE AREA OF SEVERE WEATHER COULD RESULT. ON THE OTHER HAND...SHOULD CAP REMAIN STRONG OVER TX AND MOISTURE RETURN LIMITED ACROSS THE GULF COAST REGION...LITTLE IF ANY SEVERE WEATHER MAY OCCUR. WITH THESE QUESTIONS...AND VERY SIGNIFICANT MODEL DIFFERENCES REGARDING TIMING/LOCATION OF SEWD-MOVING FRONT...WILL MAINTAIN ONLY 5% SEVERE PROBABILITY ACROSS THE S CENTRAL AND SERN CONUS ATTM. ..GOSS.. 05/12/2006  From swody2 at goshenarc.org Fri May 12 17:37:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 May 2006 13:37:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121734 SWODY2 SPC AC 121733 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 PM CDT FRI MAY 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL GULF COAST STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN TX/SRN AR/LA... ...SYNOPSIS... BLOCKING PATTERN WILL PERSIST INTO THE DAY 2 PERIOD AS LARGE CLOSED UPPER LOW...NOW CENTERED OVER THE WRN GREAT LAKES...SETTLES SWD ACROSS THE OH VALLEY...AND THE UPSTREAM RIDGE BUILDS NWD OVER THE WRN STATES/SWRN CANADA. A COUPLE OF WEAK SHORT WAVE TROUGHS WITHIN STRONG NWLY FLOW REGIME ALONG WRN/SRN PERIPHERIES OF UPPER CYCLONE WILL AID IN THUNDERSTORMS ACROSS THE CENTRAL GULF COAST STATES...AND THEN LATE IN THE PERIOD OVER SERN PLAINS/LOWER MS VALLEY. AT THE SURFACE...A WEAK BOUNDARY EXTENDING FROM THE TX PANHANDLE ESE THROUGH RED RIVER/LOWER MS VALLEYS TO FL PANHANDLE IS EXPECTED TO REMAIN NEARLY STATIONARY SATURDAY. THIS BOUNDARY SHOULD THEN MOVE SWD SATURDAY NIGHT AS COLD FRONT MOVES SWD INTO THE SRN PLAINS AND THROUGH TN VALLEY TO GULF COAST STATES. ...GULF COAST STATES... MOISTURE RETURN BY DAY 2 ACROSS THE GULF COAST STATES IS EXPECTED TO BE SUFFICIENT /SURFACE DEWPOINTS IN THE UPPER 50S TO AROUND 60/ FOR A THREAT OF SEVERE STORMS...GIVEN AN ELEVATED MIXED LAYER/STEEP LAPSE RATE ENVIRONMENT ADVECTING EWD ATOP THIS LOW-LEVEL MOISTENING. SATURDAY AFTERNOON MLCAPE VALUES SHOULD RANGE FROM 800-1200 J/KG. AT THE START OF THE PERIOD...ELEVATED THUNDERSTORMS MAY BE ONGOING ACROSS ERN OK INTO THE LOWER MS VALLEY. THIS ACTIVITY WILL BE ASSOCIATED WITH WAA ALONG THE NOSE OF A WSWLY ORIENTED LLJ. THIS WAA ACTIVITY WILL SPREAD EWD ACROSS THE GULF COAST STATES AS ASSOCIATED WEAK MID LEVEL IMPULSE TRACKS ESEWD ACROSS THE REGION. STORMS SHOULD BECOME SURFACE BASED BY SATURDAY AFTERNOON AS SURFACE HEATING WEAKENS THE CAP...WITH THE INSTABILITY AND STRONG DEEP LAYER SHEAR PER 50-70 KT WNWLY MID LEVEL JET SUPPORTING ORGANIZED STORMS/ SUPERCELLS. ...ERN TX/SRN AR/LA... STRONGER CAP FURTHER WEST ACROSS LA INTO TX IS EXPECTED TO PRECLUDE THUNDERSTORM DEVELOPMENT UNTIL SATURDAY EVENING ALONG/N OF STATIONARY BOUNDARY...AND APPROACHING COLD FRONT. INCREASING SWLY LLJ/WAA ACROSS ERN TX AND MOISTENING LOW LEVEL AIR MASS EXPECTED TO RESULT IN SUFFICIENT DESTABILIZATION FOR ELEVATED THUNDERSTORMS AS A SHORT WAVE TROUGH APPROACHES ERN TX/LOWER MS VALLEY SATURDAY NIGHT. MODERATE INSTABILITY AND STRONG EFFECTIVE BULK SHEAR VALUES EXPECTED TO SUPPORT POTENTIAL FOR ELEVATED SUPERCELLS...WITH ACTIVITY EVOLVING INTO AN MCS AND TRACKING SE ACROSS ERN TX/LA SATURDAY NIGHT. A CONDITIONAL THREAT FOR SEVERE AND LOWER SEVERE PROBABILITIES EXIST ACROSS W TX WHERE MODELS DIFFER ON THE DEVELOPMENT OF SURFACE BASED STORMS LATE SATURDAY AFTERNOON. IF ACTIVITY DEVELOPS...THEN INSTABILITY/SHEAR VALUES WOULD SUPPORT A FEW ORGANIZED STORMS WITH POTENTIAL FOR UPSCALE GROWTH INTO AN MCS SATURDAY EVENING. PARTS OF THIS REGION MAY REQUIRE AN UPGRADE IN SEVERE PROBABILITIES IN LATER OUTLOOKS. ..PETERS.. 05/12/2006  From swody2 at goshenarc.org Sat May 13 06:05:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 May 2006 02:05:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130603 SWODY2 SPC AC 130602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT SAT MAY 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CAROLINAS AND VICINITY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WRN TX/SERN NM... ...SYNOPSIS... LARGE-SCALE PATTERN -- FEATURING A RIDGE OVER THE WRN HALF OF THE CONUS AND A TROUGH/CLOSED LOW OVER THE EAST -- IS FORECAST TO UNDERGO SLIGHT AMPLIFICATION THIS PERIOD...BUT OTHERWISE REMAIN GENERALLY UNCHANGED. SURFACE FRONT -- INITIALLY FORECAST FROM THE ATLANTIC COAST STATES SWWD/WWD ACROSS THE GULF COAST STATES INTO TX...IS FORECAST TO MOVE EWD TOWARD THE ATLANTIC COAST/SWD TOWARD THE GULF COAST/SWWD INTO FAR W TX THROUGH THE PERIOD. THIS FRONT SHOULD SERVE AS A FOCUS FOR DEEP MOIST CONVECTION THROUGH THE PERIOD. ...THE CAROLINAS AND VICINITY... SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ALONG/AHEAD OF FRONT. CONVECTION SHOULD INCREASE/INTENSIFY DURING THE AFTERNOON AS DIURNAL HEATING -- LIKELY LIMITED BY ONGOING CLOUDS/PRECIPITATION -- RESULTS IN LIMITED AIRMASS DESTABILIZATION /AROUND 1000 J/KG MEAN-LAYER CAPE/. WITH MODERATELY-STRONG SWLY/WLY FLOW THROUGH A DEEP LAYER EXPECTED ACROSS THIS REGION/S OF UPPER TROUGH...EXPECT ORGANIZED STORMS -- POSSIBLY A SQUALL LINE -- TO EVOLVE. POTENTIAL FOR SEVERE CONVECTION WITH LOCALLY DAMAGING WINDS AND HAIL APPEARS HIGH ENOUGH ATTM TO WARRANT INTRODUCTION OF A SLIGHT RISK ACROSS THIS REGION. ...PARTS OF WRN TX/SERN NM... MODELS FORECAST ONGOING CONVECTION ALONG AND NEAR FRONT DURING THE START OF THE PERIOD...WHICH SHOULD WEAKEN AND THEN RE-INITIATE DURING THE AFTERNOON. THOUGH ISOLATED STRONG/SEVERE STORMS MAY OCCUR ACROSS THE GULF COAST REGION AND INTO TX...AREA OF SLIGHTLY GREATER SEVERE THREAT MAY EVOLVE ACROSS W TX. AS FRONT MOVES SWD/SWWD ACROSS TX...AREA OF ELY UPSLOPE FLOW SHOULD EVOLVE ACROSS THE TRANSPECOS REGION AND INTO SERN NM. WITH MODERATE WSWLY FLOW ALOFT FORECAST OVER THIS REGION...RESULTING DIRECTIONAL SHEAR MAY BE SUFFICIENT FOR ORGANIZED STORMS. ALONG WITH POTENTIAL FOR HAIL...DRY/DEEP BOUNDARY LAYER WOULD ALSO SUPPORT THREAT FOR DAMAGING WINDS. ..GOSS.. 05/13/2006  From swody2 at goshenarc.org Sat May 13 17:33:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 May 2006 13:33:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131731 SWODY2 SPC AC 131730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT SAT MAY 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC AND SOUTHEAST STATES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SWRN LA WWD THROUGH CENTRAL/SRN TX INTO SW TX/SERN NM... ...SYNOPSIS... LARGE CLOSED UPPER LOW ENCOMPASSING MUCH OF THE ERN TWO-THIRDS OF THE U.S. IS EXPECTED TO WEAKEN SOME ON SUNDAY AS THE CENTER TRACKS SLOWLY SEWD THROUGH THE OH VALLEY. STRONG BAND OF MID LEVEL WINDS /60-80 KT/ WILL EXTEND ALONG THE SWRN/SRN TO ERN PERIPHERY OF THIS LARGE UPPER CYCLONE...RESULTING IN A CONTINUATION OF STRONG DEEP LAYER SHEAR ACROSS THESE REGIONS. SERIES OF VORTICITY/JET MAXIMA WILL CONTINUE TO ROTATE THROUGH THE UPPER LOW. ONE SUCH SPEED MAX...NOW LOCATED NEAR MKC...IS EXPECTED TO TRANSLATE FROM THE TN VALLEY NEWD ACROSS GA/CAROLINAS TO THE DELMARVA REGION DURING DAY 2 PERIOD. AT THE SURFACE...LOW PRESSURE...ASSOCIATED WITH TN VALLEY SHORT WAVE TROUGH/SPEED MAX...SHOULD BE LOCATED OVER THE SRN APPALACHIANS AT 12Z SUNDAY. THIS LOW IS EXPECTED TO TRACK ENE REACHING CENTRAL/NERN NC BY SUNDAY EVENING...BEFORE TRACKING MORE NNE TOWARD THE DELMARVA REGION SUNDAY NIGHT. COLD FRONT WILL MOVE EWD ACROSS THE MID-ATLANTIC/SERN STATES. THE WWD TRAILING PORTION OF THIS BOUNDARY SHOULD MOVE SWD THROUGH CENTRAL GULF COAST STATES AND TX...REACHING THE GULF COAST AND SRN TX BY 12Z MONDAY. ...MID-ATLANTIC AND SOUTHEAST STATES... LOW-LEVEL MOISTURE /SURFACE DEWPOINTS UPPER 50S TO AROUND 60/ IS EXPECTED TO ADVECT NEWD FROM THE GULF COAST STATES AND ALSO NWD FROM THE ATLANTIC WATERS INTO GA TO VA IN ADVANCE OF THE APPROACHING SURFACE LOW AND TRAILING COLD FRONT. ALTHOUGH THUNDERSTORMS SHOULD BE ONGOING AT 12Z SUNDAY ACROSS PARTS OF THIS REGION...STRONG SURFACE HEATING IN THE WAKE OF INITIAL ACTIVITY COMBINED WITH MOISTURE RETURN WILL LIKELY RESULT IN MODERATE INSTABILITY BY SUNDAY AFTERNOON. NEW THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG SURFACE LOW/TRAILING COLD FRONT BY AFTERNOON AS TN VALLEY TROUGH MOVES ACROSS REGION. STRONG DEEP LAYER SHEAR IS EXPECTED TO SUPPORT MULTIPLE STORM MODES WITH BOTH SUPERCELLS AND LINEAR STRUCTURES POSSIBLE. SRN SEVERE THREAT ACROSS GA MAY MOVE INTO FAR NRN FL INCLUDING ERN FL PANHANDLE BY SUNDAY EVENING. ...SRN LA/CENTRAL-SRN TX TO SW TX/SERN NM... AT 12Z SUNDAY...ONGOING STRONG TO SEVERE THUNDERSTORM CLUSTER IS EXPECTED TO BE LOCATED ACROSS PARTS OF NERN TX EWD INTO NRN LA/MS. AIR MASS SOUTH OF THIS EARLY ACTIVITY FROM SRN LA INTO CENTRAL/SRN TX IS EXPECTED TO BECOME VERY UNSTABLE WITH SUNDAY AFTERNOON MLCAPE VALUES RANGING FROM 2000 J/KG IN SWRN LA TO 2500-3000 J/KG WWD INTO TX. GFS/NAMP SUGGEST A SERIES OF WEAK SRN STREAM IMPULSES WILL TRACK FROM THE FOUR CORNERS REGION SEWD ACROSS TX TO THE NWRN GULF... WITH LATEST WATER VAPOR IMAGERY INDICATING THESE IMPULSES FROM THE ERN PACIFIC TO THE FOUR CORNERS REGION. LARGE SCALE ASCENT WITH THESE FEATURES COMBINED WITH LOW LEVEL FORCING ALONG THE COLD FRONT IS EXPECTED TO SUPPORT ADDITIONAL THUNDERSTORMS FROM THE CENTRAL GULF COAST WWD INTO CENTRAL/SRN TX AS THE FRONT MOVES SWD. THE COMBINATION OF STRONG INSTABILITY/VERY STEEP LAPSE RATES AND STRONG DEEP LAYER SHEAR ARE EXPECTED TO SUPPORT ORGANIZED SEVERE STORMS FROM SWRN LA WWD INTO CENTRAL/SRN TX. THE SEVERE THREAT MAY PERSIST INTO THE OVERNIGHT PERIOD ACROSS SRN TX WHERE INSTABILITY/SHEAR VALUES WILL REMAIN SUFFICIENT. FURTHER W...THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE HIGHER TERRAIN OF THE CENTRAL/SRN ROCKIES INTO SWRN TX...WITH THE GREATEST POTENTIAL FOR A SEVERE THREAT ACROSS SW TX INTO SERN NM WHERE LOW LEVEL MOISTURE RETURN WILL BE STRONGEST. ELY LOW LEVEL UPSLOPE FLOW BENEATH MODERATE WLY MID LEVEL WINDS WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STORMS WITH HAIL/STRONG WIND GUSTS THE GREATEST THREATS GIVEN STEEP LAPSE RATES. ..PETERS.. 05/13/2006  From swody2 at goshenarc.org Sun May 14 05:21:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 May 2006 01:21:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140518 SWODY2 SPC AC 140517 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 AM CDT SUN MAY 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LITTLE CHANGE IN OVERALL UPPER PATTERN ANTICIPATED THIS PERIOD...AS UPPER LOW/TROUGH PERSISTS ACROSS THE ERN HALF OF THE CONUS AND A STRONG RIDGE PREVAILS OVER THE WEST. AT THE SURFACE...FRONT WILL CONTINUE PUSHING SWD ACROSS FL/THE GULF OF MEXICO/TX...AND WWD INTO THE ROCKIES. THIS BOUNDARY WILL SERVE AS A FOCUS FOR SCATTERED/GENERALLY SUB-SEVERE STORMS THROUGH THE PERIOD. ...FL PENINSULA... SCATTERED THUNDERSTORMS ARE ANTICIPATED ACROSS PARTS OF THE FL PENINSULA THIS PERIOD S OF WEAKENING/SWD-MOVING FRONT. THOUGH LOW-LEVEL CONVERGENCE SHOULD BE GENERALLY WEAK ALONG FRONT...LOCALLY GREATER CONVERGENCE -- PARTICULARLY INVOF SEA BREEZE BOUNDARIES -- SHOULD BE SUFFICIENT FOR STORM DEVELOPMENT WITHIN MODERATELY- UNSTABLE /1000 TO 200O J/KG MEAN-LAYER CAPE/ AFTERNOON AIRMASS. THOUGH AMPLE LOW- TO MID-LEVEL FLOW /40 TO 50 KT/ IS FORECAST ACROSS THIS AREA...ROUGHLY UNIDIRECTIONAL/WLY FLOW FIELD SHOULD LIMIT DEEP-LAYER SHEAR. NONETHELESS...SHEAR/INSTABILITY COMBINATION MAY SUPPORT A FEW STRONGER UPDRAFTS...CAPABLE OF PRODUCING BRIEF DAMAGING GUSTS OR MARGINAL HAIL. ..GOSS.. 05/14/2006  From swody2 at goshenarc.org Sun May 14 17:31:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 May 2006 13:31:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141728 SWODY2 SPC AC 141727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SUN MAY 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE LOCATED ACROSS ERN CANADA THAT HAS RESULTED IN LITTLE MOVEMENT OF LARGE ERN U.S. CLOSED LOW IS EXPECTED TO WEAKEN DURING THE DAY 1 PERIOD. FURTHER HEIGHT FALLS ACROSS ERN CANADA ON MONDAY WILL ALLOW FOR AN ENEWD MOVEMENT OF THE UPPER CYCLONE WITH THE CENTER MIGRATING SLOWLY TOWARD THE UPPER OH VALLEY/LOWER GREAT LAKES REGION. AT 12Z MONDAY...A COLD FRONT IS EXPECTED TO EXTEND FROM ERN PARTS OF THE MID-ATLANTIC REGION SWWD THROUGH SRN GA TO THE NRN GULF AND SRN TX...THEN NWWD INTO SRN ROCKIES. TX PORTION OF BOUNDARY WILL MOVE SWD INTO RIO GRANDE VALLEY/NRN MEXICO DURING PERIOD. ERN EXTENT OF FRONT /GA TO CAROLINAS/ EXPECTED TO HAVE GREATER S AND E MOVEMENT MONDAY NIGHT AS STRONGER HEIGHT FALLS DEVELOP ACROSS REGION WITH APPROACH OF SHORT WAVE TROUGH INTO LOWER MS VALLEY. ...FL PENINSULA... SRN GA/NRN FL WILL REMAIN WITHIN ENTRANCE REGION OF MID LEVEL SPEED MAX TRANSLATING THROUGH SERN-ERN PERIPHERY OF UPPER CYCLONE ON MONDAY. THIS WILL MAINTAIN FORCING FOR UPWARD VERTICAL MOTION ALONG THE COLD FRONT. THUS...THUNDERSTORMS WILL BE POSSIBLE ALONG THIS BOUNDARY...BUT OVERALL INTENSITY SHOULD BE LIMITED GIVEN GENERALLY WEAK LOW-LEVEL CONVERGENCE PER EXPECTED DEEP WLY FLOW ACROSS SERN STATES. ADDITIONAL STORMS WILL BE POSSIBLE SWD THROUGH THE PENINSULA GIVEN SEA-LAKE BREEZE INTERACTIONS WITHIN MOIST AIR MASS. A FEW STORMS WILL BE POSSIBLE ACROSS THE FL PENINSULA WHERE POCKETS OF STRONGER INSTABILITY CAN DEVELOP...GIVEN EXPECTED SUFFICIENT DEEP LAYER SHEAR. ...SRN TX TO FOUR CORNERS REGION... THUNDERSTORMS MAY BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF DEEP S TX/LOWER RIO GRANDE VALLEY NWWD INTO THE HIGHER TERRAIN OF NM ALONG SURFACE COLD FRONT. ADDITIONAL DEVELOPMENT IS LIKELY AS THIS BOUNDARY MOVES SOUTH AND WEST...BUT OVERALL WEAK INSTABILITY IS EXPECTED TO LIMIT AND LIKELY PRECLUDE SEVERE POTENTIAL. NWWD MOISTURE ADVECTION INTO SRN NM/ERN AZ WILL AID IN INCREASING POTENTIAL FOR THUNDERSTORM DEVELOPMENT TOWARD FOUR CORNERS REGION MONDAY AFTERNOON. ..PETERS.. 05/14/2006  From swody2 at goshenarc.org Mon May 15 05:23:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 May 2006 01:23:38 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150520 SWODY2 SPC AC 150519 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1219 AM CDT MON MAY 15 2006 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... FURTHER AMPLIFICATION OF UPPER PATTERN EXPECTED THIS PERIOD...WHILE WRN RIDGE/ERN TROUGH CONFIGURATION PERSISTS. SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF THE ERN CONUS BENEATH UPPER TROUGH...AND OVER THE HIGHER ELEVATIONS ACROSS PORTIONS OF THE WEST. ANY SEVERE THREAT SHOULD REMAIN LIMITED TO A STRONGER CELL OR TWO OVER CENTRAL/SRN FL S OF WEAK COLD FRONT. ...CENTRAL/SRN FL... WEAK COLD FRONT IS EXPECTED TO LINGER/DRIFT SLOWLY SWD ACROSS FL THIS PERIOD...WHERE MOIST BOUNDARY LAYER BUT WEAK MID-LEVEL LAPSE RATES ARE ANTICIPATED. WITH MID-LEVEL FLOW NEAR 50 KT...A STRONGER STORM OR TWO COULD DEVELOP -- EITHER NEAR FRONT OR INVOF SEA-BREEZE BOUNDARIES -- WHICH COULD PRODUCE MARGINAL HAIL OR A LOCALLY-DAMAGING GUST. HOWEVER...OVERALL THREAT SHOULD REMAIN LIMITED BY LACK OF FAVORABLE THERMODYNAMICS. ..GOSS.. 05/15/2006  From swody2 at goshenarc.org Mon May 15 16:59:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 May 2006 12:59:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151656 SWODY2 SPC AC 151655 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CDT MON MAY 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS SOUTH FL... ...SYNOPSIS... LARGE SCALE PATTERN WILL REMAIN DOMINATED BY OMEGA-BLOCK OVER THE U.S. WITH STRONG UPPER LOW OVER THE EAST AND A LARGE RIDGE OVER THE ROCKIES AND INTERMOUNTAIN WEST. DEEP NLY FLOW IN WAKE OF ERN U.S. UPPER SYSTEM WILL MAINTAIN OFFSHORE FLOW WELL INTO THE GULF OF MEXICO AND LIMIT OVERALL THREAT OF STRONG TO SEVERE THUNDERSTORMS THROUGH THE PERIOD. EXCEPTION WILL REMAIN ACROSS THE SRN HALF OF FL WHERE BOUNDARY LAYER WILL REMAIN RELATIVELY MOIST /I.E. SURFACE DEW POINTS AROUND 70F/ AND WLY FLOW ALOFT WILL REMAIN SUFFICIENT FOR MODEST DEEP LAYER SHEAR. ...SRN FL... CLOUDS FROM RESIDUAL CONVECTION MAY LIMIT HEATING AND ASSOCIATED INSTABILITY DURING THE DAY OVER S FL. HOWEVER...QUALITY OF LOW LEVEL MOISTURE AND 30-40 KT EFFECTIVE BULK SHEAR SUGGEST EVEN MODEST HEATING WILL SUPPORT A FEW SEVERE THUNDERSTORMS TUESDAY AFTERNOON/EVENING. ACTIVITY WILL INCREASE BY THE EARLY AFTERNOON AHEAD OF A SLOW MOVING COLD FRONT ORIENTED E-W ACROSS CENTRAL FL AND ALONG OUTFLOW BOUNDARIES AND SEA BREEZES ACROSS SRN FL. SHOULD EVEN MODEST INSTABILITY DEVELOP...EXPECT ACTIVITY WILL ORGANIZE INTO MULTICELL CLUSTERS AND BRIEF SUPERCELLS WITH PRIMARY THREATS OF LARGE HAIL AND DAMAGING WINDS INTO THE EARLY EVENING. ..EVANS.. 05/15/2006  From swody2 at goshenarc.org Tue May 16 06:00:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 16 May 2006 02:00:12 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160556 SWODY2 SPC AC 160555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE MAY 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED LARGE-SCALE UPPER PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD AND BEYOND. STRONGER FLOW WILL REMAIN SPLIT IN BELTS AROUND BLOCKING RIDGE ENCOMPASSING MUCH OF THE INTERMOUNTAIN WEST...BEFORE MERGING INTO A BROAD TROUGH EAST OF THE PLAINS INTO THE WESTERN ATLANTIC. MODELS SUGGEST THAT A CLOSED LOW EMBEDDED WITHIN LATTER FEATURE WILL FINALLY LIFT NORTHEAST OF THE OHIO VALLEY LATER TODAY/TONIGHT...BEFORE CONTINUING NORTHEASTWARD INTO THE CANADIAN MARITIMES WEDNESDAY. THIS WILL BE ACCOMPANIED BY THE NORTHEASTWARD ACCELERATION OF A LOWER AMPLITUDE IMPULSE OUT OF THE BASE OF THE LARGER SCALE TROUGH NEAR EASTERN GULF COASTAL AREAS...THROUGH THE MID/SOUTH ATLANTIC COAST STATES BY LATE WEDNESDAY NIGHT. HOWEVER...AN UPSTREAM NORTHERN BRANCH SHORT WAVE TROUGH/JET STREAK IS PROGGED TO SUPPORT THE EVOLUTION OF ANOTHER CLOSED LOW AS IT DIGS OUT OF CENTRAL CANADA THROUGH THE UPPER GREAT LAKES REGION. ...EAST OF THE ROCKIES... THE PRIMARY FRONTAL ZONE ASSOCIATED WITH THE EASTERN TROUGH IS EXPECTED OFF THE SOUTH ATLANTIC COAST...AND SOUTH/EAST OF THE FLORIDA PENINSULA BY 12Z WEDNESDAY. IN ITS WAKE...BOUNDARY LAYER MOISTURE ACROSS MOST AREAS WILL BE SEASONABLY LOW. THIS MAY NOT PRECLUDE AREAS OF SCATTERED CONVECTIVE DEVELOPMENT...BUT POTENTIAL FOR STRONG/SEVERE THUNDERSTORMS IS EXPECTED TO REMAIN LOW. A LINGERING MID-LEVEL THERMAL TROUGH COULD PROVIDE THE FOCUS FOR SCATTERED THUNDERSTORMS WITH DAYTIME HEATING ACROSS THE ATLANTIC COAST STATES...MAINLY IN THE LEE OF THE CENTRAL/SOUTHERN APPALACHIANS. DIURNAL ACTIVITY IS POSSIBLE AS FAR TO THE SOUTH AND WEST AS THE CENTRAL GULF STATES. HOWEVER...THE MAIN CONVECTIVE POTENTIAL WEDNESDAY SEEMS LIKELY TO ACCOMPANY STRONGER MID/UPPER FORCING FOR UPWARD VERTICAL MOTION AHEAD OF DIGGING UPPER GREAT LAKES SHORT WAVE TROUGH. MODELS SUGGEST LAPSE RATES COULD BECOME FAIRLY STEEP ABOVE LOW-LEVEL THERMAL RIDGE IN ADVANCE OF REINFORCING COOL/DRY SURGE. AND... LOWER/MID 50S SURFACE DEW POINTS ARE GENERALLY EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE AROUND 500 J/KG. LOCALLY STRONGER DESTABILIZATION IS POSSIBLE...SUPPORTING THE DEVELOPMENT OF SCATTERED THUNDERSTORMS BY PEAK HEATING. FAVORABLE DEEP LAYER SHEAR ASSOCIATED WITH MODERATELY STRONG CYCLONIC MID-LEVEL FLOW IS EXPECTED TO SUPPORT ONE OR MORE CONVECTIVE BANDS...WHICH PROBABLY WILL BE ACCOMPANIED BY RISK OF GUSTY WINDS/HAIL WHICH COULD APPROACH OR BRIEFLY EXCEED SEVERE LIMITS. ACTIVITY SHOULD WEAKEN FAIRLY QUICKLY AFTER DARK AS IT SPREADS EASTWARD THROUGH THE LOWER OHIO VALLEY. ...ROCKIES AND INTERMOUNTAIN WEST... MOISTURE...MOSTLY TO THE SOUTH/WEST OF UPPER HIGH CENTER...IS EXPECTED TO REMAIN SUFFICIENT FOR SCATTERED THUNDERSTORM ACTIVITY WEDNESDAY. THIS WILL MOSTLY OCCUR IN RESPONSE TO HEATING ACROSS THE HIGHER TERRAIN. THOUGH POCKETS OF STRONGER INSTABILITY COULD DEVELOP...CAPE IN WEAKLY SHEARED REGIME IS EXPECTED TO AVERAGE ON THE ORDER OF A FEW HUNDRED J/KG. THIS WILL LIMIT STRENGTH OF UPDRAFTS...BUT STEEP LAPSE RATES WITH LARGE LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL PROVIDE FAVORABLE PROFILES FOR HIGHLY LOCALIZED/ISOLATED MICROBURSTS. ..KERR.. 05/16/2006  From swody2 at goshenarc.org Tue May 16 17:38:25 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 16 May 2006 13:38:25 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161735 SWODY2 SPC AC 161734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT TUE MAY 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY... INTENSIFYING UPPER SPEED MAX WILL DIG ACROSS MN TOWARD THE OH VALLEY WEDNESDAY FORCING SFC COLD FRONT SEWD TO A POSITION FROM SRN LOWER MI...ARCING INTO ERN NEB DURING THE LATE AFTERNOON HOURS. LARGE SCALE ASCENT WILL BE FOCUSED WITHIN EXIT REGION OF THIS SPEED MAX WHICH SHOULD ENHANCE CONVECTIVE POTENTIAL ALONG ADVANCING BOUNDARY BY EARLY AFTERNOON. LATEST MODEL GUIDANCE SUGGEST STRONG BOUNDARY LAYER HEATING...8.5-9C/KM LAPSE RATES IN THE LOWEST 3KM...WILL DEVELOP ACROSS THE CNTRL PLAINS EWD ALONG WIND SHIFT INTO CNTRL IA. THIS PLUME OF STRONG HEATING WILL DEVELOP/SPREAD EWD BENEATH COLD UPPER TROUGH ENHANCING SFC BASED INSTABILITY...500-1000J/KG. DESPITE MEAGER MOISTURE NOTED ACROSS THIS REGION...SFC DEW POINTS IN THE UPPER 40S TO NEAR 50F...COLD MID LEVEL TEMPS AND STEEP LAPSE RATES WILL YIELD FAVORABLE THERMODYNAMIC PROFILES FOR STRONG UPDRAFT DEVELOPMENT CAPABLE OF GENERATING AT LEAST MARGINALLY SEVERE HAIL. ACTIVITY SHOULD BE MOST CONCENTRATED DURING THE AFTERNOON INTO THE EVENING HOURS AS FRONT SURGES SOUTH TOWARD THE OH RIVER. ...PACIFIC NW... UPPER RIDGE WILL HOLD ACROSS THE WRN U.S. THIS PERIOD WITH WEAK SWLY FLOW EXPECTED TO GRADUALLY INCREASE OVER WA/ORE LATE IN THE PERIOD AS HEIGHTS BEGIN TO FALL. IT APPEARS ISOLATED THUNDERSTORMS SHOULD DEVELOP BENEATH THE UPPER RIDGE WHERE STRONG HEATING AND OROGRAPHIC LIFT WILL BE MAXIMIZED. FORECAST SOUNDINGS ALSO SUGGEST HAIL IS LIKELY WITH THE STRONGER UPDRAFTS. CONVECTION WILL BE STRONGLY DIURNAL AND DIE QUICKLY AFTER SUNSET. ..DARROW.. 05/16/2006  From swody2 at goshenarc.org Wed May 17 05:27:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 17 May 2006 01:27:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170524 SWODY2 SPC AC 170523 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 AM CDT WED MAY 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... BLOCKING UPPER HIGH CENTER REMAINS STRONG OVER THE INTERMOUNTAIN WEST...AND AN AMPLIFIED SPLIT FLOW PATTERN IS EXPECTED TO PERSIST ACROSS MUCH OF NORTH AMERICA THROUGH THIS FORECAST PERIOD. HOWEVER...A SIGNIFICANT IMPULSE LIFTING OUT OF THE NORTHEAST PACIFIC THROUGH RIDGE AXIS ACROSS THE CANADIAN ROCKIES WILL CONTRIBUTE TO MID-LEVEL HEIGHT FALLS LATER TODAY/TONIGHT. AND...FURTHER WEAKENING OF UPPER RIDGE WILL OCCUR SOUTHWARD THROUGH THE NORTHERN PACIFIC COAST STATES THURSDAY/THURSDAY NIGHT...AHEAD OF UPSTREAM TROUGH AXIS SLOWLY APPROACHING THE PACIFIC COAST. FARTHER EAST...MODELS INDICATE THAT A STRONG DIGGING JET STREAK IN THE NORTHERN BRANCH OF THE WESTERLIES WILL CONTRIBUTE TO THE DEVELOPMENT OF ANOTHER CLOSED LOW OVER THE GREAT LAKES/UPPER OHIO VALLEY REGION. THIS FEATURE IS PROGGED TO OVERSPREAD ACROSS MUCH OF THE REMAINDER OF THE NORTHEAST BY 12Z FRIDAY. WITH THE INTERMOUNTAIN WEST ONLY CONTINUING TO GRADUALLY MOISTEN...AND MOISTURE LEVELS EAST OF THE ROCKIES REMAINING SEASONABLY LOW UNDER THE INFLUENCE OF SUCCESSIVE COOL/DRY SURGES ASSOCIATED WITH PERSISTENT UPPER TROUGH...CONVECTIVE POTENTIAL IS EXPECTED TO REMAIN LIMITED. DESTABILIZATION IS EXPECTED TO BECOME SUFFICIENT FOR AREAS OF SCATTERED THUNDERSTORMS THURSDAY/THURSDAY NIGHT...BUT MOST ACTIVITY IS EXPECTED TO REMAIN RELATIVELY WEAK. ...EAST OF ROCKIES... THE LEADING EDGE OF STRONGER MID-LEVEL COOLING/LIFT IN EXIT REGION OF 70-90 KT CYCLONIC 500 MB JET STREAK STILL SEEMS LIKELY INTO MUCH OF THE NORTHERN/CENTRAL APPALACHIANS BY MIDDAY THURSDAY. THIS...IN CONJUNCTION WITH FAVORABLE OROGRAPHIC FORCING...IS EXPECTED TO SUPPORT INITIATION OF CONVECTIVE DEVELOPMENT...WHICH SHOULD DEVELOP EASTWARD WITH UPPER FORCING TOWARD THE HUDSON VALLEY AND MID ATLANTIC COASTAL AREAS THURSDAY AFTERNOON. THOUGH CAPE WILL BE WEAK...COOL THERMODYNAMIC PROFILES WILL BE SUPPORTIVE OF HAIL...PERHAPS LOCALLY GUSTY WINDS...IN STRONGER CELLS...SOME OF WHICH COULD APPROACH OR BRIEFLY EXCEED SEVERE CRITERIA. THREAT SHOULD DIMINISH QUICKLY THURSDAY EVENING WITH LOSS OF HEATING. OTHERWISE...BANDS OF CONVECTION AND SCATTERED THUNDERSTORMS ARE EXPECTED DURING THE DAYTIME HOURS SOUTH/SOUTHEAST OF DEVELOPING UPPER LOW...PARTICULARLY NEAR THE SOUTHERN FRINGE OF THE MID-LEVEL COLD CORE ACROSS THE OHIO VALLEY. MODELS SUGGEST THAT ADDITIONAL THUNDERSTORMS ARE POSSIBLE BY LATE THURSDAY/THURSDAY NIGHT FROM PARTS OF THE MID MISSOURI VALLEY INTO THE MIDDLE MISSISSIPPI VALLEY. THIS IS EXPECTED AS MOISTURE OF PACIFIC ORIGINS ADVECTS AROUND CREST OF UPPER RIDGE INTO FAVORABLE LOWER/MID TROPOSPHERIC WARM ADVECTION REGIME EAST OF RIDGE...AND IN WAKE OF CLOSED LOW. ...INTERMOUNTAIN WEST/PACIFIC COAST STATES... SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED ONCE AGAIN THURSDAY... MAINLY SOUTH/WEST OF UPPER RIDGE...AND IN RESPONSE TO HEATING ACROSS THE HIGHER TERRAIN. MODELS SUGGEST THAT A WEAK IMPULSE EMBEDDED WITHIN STRENGTHENING SOUTHERLY MID/UPPER FLOW COULD CONTRIBUTE TO MORE EXTENSIVE CONVECTIVE DEVELOPMENT IN THE LEE OF THE SOUTHERN CASCADES AFTER PEAK HEATING. CAPE IS EXPECTED TO REMAIN WEAK...LIMITING STRENGTH OF UPDRAFTS...BUT 700-500 MB FLOW ON THE ORDER OF 30 TO 40 KTS COULD ENHANCE DOWNBURST POTENTIAL IN DRY DEEP MIXED BOUNDARY LAYER. ISOLATED DAMAGING WIND GUSTS APPEAR POSSIBLE THROUGH THURSDAY EVENING...MAINLY ACROSS PARTS OF CENTRAL/EASTERN OREGON. ..KERR.. 05/17/2006  From swody2 at goshenarc.org Fri May 19 06:01:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 May 2006 02:01:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190558 SWODY2 SPC AC 190557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT FRI MAY 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN KS/MO SEWD INTO THE SRN PORTION OF THE TN VALLEY... ...SYNOPSIS... OVERALL PATTERN WILL CHANGE LITTLE WITH HIGHLY AMPLIFIED TROUGH REMAINING ACROSS THE WEST AND A STRONG TROUGH LOCATED ACROSS THE NERN QUARTER OF THE COUNTRY. THE PAST FEW MODEL RUNS HAVE EVOLVED TO A STRONGER SHORTWAVE TROUGH/JET MAX/COLD FRONT SHIFTING FROM THE WRN GREAT LAKES INTO NY DURING THE PERIOD. THE REMNANTS OF A WEAK FRONT ARE FORECAST TO STRETCH FROM SRN KS ESEWD INTO THE SRN PORTION OF THE TN VALLEY AND THEN EWD INTO THE CAROLINAS. BETWEEN THE TWO UPPER TROUGHS...MID/HIGH LEVEL MOISTURE...TRAPPED BENEATH UPPER RIDGE OVER THE ROCKIES...COMBINED WITH DAYTIME HEATING WILL RESULT IN SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE HIGHER TERRAIN. ...ERN KS/MO SEWD ACROSS NRN AR AND INTO THE SRN TN VALLEY AREA... A MOSTLY NON SEVERE MCS IS EXPECTED TO BE MOVING THROUGH THE CAROLINAS EARLY IN THE PERIOD...AS ASSOCIATED SPEED MAX MOVES OFFSHORE. ONCE THESE STORMS MOVE OFFSHORE...UNCERTAINTY EXISTS WHEN AND WHERE MORE STORMS WILL REDEVELOP. ALTHOUGH FRONT IS FORECAST TO REMAIN NEARLY QUASI-STATIONARY THROUGH THE DAY...500 MB HEIGHTS ARE PROGGED TO RISE SLIGHTLY. NO SHORTWAVE TROUGHS ARE EVIDENT WITHIN 30-40 KT NWLY FLOW MID LEVEL FLOW...THOUGH VEERING WIND PROFILES WOULD PROVIDE FAVORABLE SHEAR FOR SEVERE STORMS. ALTHOUGH MODEL FORECAST OF MID TO UPPER 60S DEWPOINTS APPEARS TO BE OVERESTIMATED...SURFACE DEWPOINTS NEAR 60F AND 850-500 MB LAPSE RATES AROUND 7.5 C/KM SHOULD YIELD AFTERNOON MLCAPES FROM 2000-2500 J/KG. VERY WARM TEMPERATURES AND DRY AIR BETWEEN 700-850 MB SHOULD INHIBIT CONVECTION SOUTH AND WEST OF FRONT. HOWEVER ANY FORCING ON THE COOL SIDE OF THE FRONT MAY PROVIDE ENOUGH LIFT FOR PARCELS TO REACH THE LFC. IF STORMS DO DEVELOP...THE SHEAR AND DEGREE OF INSTABILITY WOULD SUPPORT STORMS WITH SEVERE HAIL AND DAMAGING WINDS. ...WI... THOUGH SLIGHT DIFFERENCES EXIST IN TIMING OF SHORTWAVE TROUGH/ SPEED MAX...MODELS SUGGEST STRONG FORCING/COLD FRONT WILL MOVE ACROSS WI AROUND EARLY/MID AFTERNOON. THE STRENGTH OF THIS SYSTEM AND VERY STRONG VERTICAL WIND PROFILES APPEAR SUPPORTIVE OF A SEVERE STORM THREAT. THE ONLY QUESTION IS THE LIMITED AMOUNT OF MOISTURE IN BOUNDARY LAYER SINCE RETURN OF RICHER GULF MOISTURE WILL BE CONFINED TO THE GULF COASTAL STATES. HOWEVER...A HIGHER RISK FOR SEVERE WEATHER WOULD BE NEEDED IF THE BOUNDARY LAYER MOISTENS MORE THAN CURRENTLY EXPECTED. ...NRN ID AND WRN MT... EMBEDDED SHORTWAVE TROUGHS MOVING NEWD WITHIN 40-50 KT MID LEVEL FLOW MAY RESULT IN A FEW STORMS WITH A POTENTIAL FOR BRIEF STRONG WIND GUSTS DURING THE AFTERNOON/EVENING HOURS. ..IMY.. 05/19/2006  From swody2 at goshenarc.org Fri May 19 17:24:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 May 2006 13:24:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191721 SWODY2 SPC AC 191719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1219 PM CDT FRI MAY 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN AND CNTRL PLAINS/OZARKS AND TN VALLEY... ...SRN AND CNTRL PLAINS/MID MS VALLEY/TN VALLEY... NORTHWEST FLOW WILL REMAIN IN PLACE TONIGHT TROUGH SATURDAY AS A COLD FRONT MOVES SLOWLY SWD INTO OK..AR...MS AND AL BY SATURDAY AFTERNOON. BY MIDDAY ON SATURDAY...WARMING SFC TEMPS...THE WEAKENING CAPPING INVERSION AND STRENGTHENING LOW-LEVEL CONVERGENCE SHOULD ALLOW ISOLATED TO SCATTERED STORMS TO INITIATE ALONG AND NEAR THE BOUNDARY. AFTERNOON FORECAST SOUNDINGS ACROSS KS...NRN OK...AR AND TN SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE WHICH WOULD BE FAVORABLE FOR SUPERCELL DEVELOPMENT NEAR POCKETS OF MODERATE INSTABILITY. STRONG STORMS WITH THE POTENTIAL FOR LARGE HAIL WILL BE MOST LIKELY IN THE PLAINS AND OZARKS WHERE MID-LEVEL LAPSE RATES ARE FORECAST TO BE THE STEEPEST. WIND DAMAGE WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS ESPECIALLY IN AREAS WHERE LOW-LEVEL LAPSE RATES ARE MAXIMIZED. ...NRN ROCKIES AND NRN HIGH PLAINS... AN UPPER-LEVEL RIDGE OVER THE ROCKIES TONIGHT WILL MOVE SLOWLY EWD. IN RESPONSE...HEIGHTS WILL FALL AND LARGE-SCALE ASCENT WILL INCREASE ACROSS THE NRN ROCKIES AND NRN HIGH PLAINS SATURDAY. AT THE SFC...A FRONTAL BOUNDARY SHOULD BE IN PLACE ACROSS CNTRL MT AND STORMS SHOULD INITIATE ALONG THE BOUNDARY AND IN THE HIGHER TERRAIN AROUND MIDDAY. AFTERNOON FORECAST SOUNDINGS IN CNTRL MT SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES WHICH SHOULD BE FAVORABLE FOR MARGINALLY SEVERE STORMS NEAR PEAK HEATING. HOWEVER...THE AMOUNT OF DESTABILIZATION THAT WILL OCCUR SATURDAY IN THE NRN HIGH PLAINS REMAINS HIGHLY UNCERTAIN. IF ENOUGH INSTABILITY DEVELOPS...SUPERCELLS WITH LARGE HAIL AND/OR WIND DAMAGE WOULD BE POSSIBLE. AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...UPPER MIDWEST... A BELT OF STRONG NORTHWEST MID-LEVEL FLOW IS FORECAST TO REMAIN IN PLACE ACROSS THE UPPER MIDWEST THROUGH SATURDAY. AS A 90 KT JET MAX PUNCHES INTO THE REGION SATURDAY AFTERNOON...INCREASING LARGE-SCALE ASCENT MAY BE ENOUGH TO ALLOW ISOLATED STORMS TO INITIATE AND MOVE SEWD ACROSS THE REGION. RELATIVELY COLD TEMPS ALOFT AND THE STRONG VERTICAL SHEAR MAY BE ENOUGH FOR A FEW HAIL STORMS. HOWEVER...THE DEGREE OF DESTABILIZATION REMAINS UNCERTAIN ATTM. IF A MARGINAL SEVERE THREAT DEVELOPS IN THE AFTERNOON...THE HAIL POTENTIAL WOULD LIKELY REMAIN VERY ISOLATED. ..BROYLES.. 05/19/2006  From swody2 at goshenarc.org Sat May 20 06:10:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 02:10:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200607 SWODY2 SPC AC 200606 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0106 AM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE MIDDLE MS VALLEY AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE PACIFIC NW AND NRN ROCKIES... ...SYNOPSIS... PATTERN WILL CHANGE LITTLE THROUGH SUNDAY WITH AN UPPER LOW DOMINATING MUCH OF THE ERN HALF OF THE COUNTRY AND AN UPPER RIDGE OVER THE ROCKIES. A SERIES OF SHORTWAVE TROUGHS EMANATING FROM ERN PACIFIC UPPER LOW WILL LIFT NWD THROUGH CA AND THE PACIFIC NW. AT THE SURFACE A FRONT WILL SETTLE SWD INTO THE TN VALLEY AND EXTEND WNWWD THROUGH SRN MO...NRN OK AND NWWD INTO THE CNTRL HIGH PLAINS. ...SERN KS...NERN OK THROUGH THE LOWER MS AND WRN TN VALLEYS... A RELATIVELY MOIST BOUNDARY LAYER WILL PERSIST NEAR FRONT FROM THE TN AND MID MS VALLEYS INTO NRN OK AND PARTS OF THE CNTRL PLAINS. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...THE ATMOSPHERE SHOULD BECOME MODERATELY UNSTABLE BY AFTERNOON. THE FRONT WILL LIKELY SERVE AS A FOCUS FOR THUNDERSTORMS THIS PERIOD. A FEW STORMS MAY BE IN PROGRESS EARLY SUNDAY IN WARM ADVECTION REGIME N OF FRONT OVER PART OF THE LOWER MS VALLEY. THE NATURE OF CONVECTIVE EVOLUTION REMAINS A BIT UNCERTAIN AT THIS TIME GIVEN EXPECTED LIMITED DEEP LAYER FORCING. HOWEVER...SOME POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE BOUNDARY AS CAP WEAKENS SUNDAY AFTERNOON. OTHER STORMS MAY DEVELOP OVERNIGHT FROM THE SRN PLAINS INTO THE LOWER MS VALLEY AS THE LOW LEVEL JET STRENGTHENS. ELY LOW LEVEL FLOW NEAR THE FRONT VEERING TO WNWLY 25 TO 30 KT AT 6 KM SUGGEST VERTICAL SHEAR WILL BE AT LEAST MARGINALLY FAVORABLE FOR ORGANIZED STORMS. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS. ...CNTRL HIGH PLAINS... THIS AREA WILL BE IN CLOSER PROXIMITY TO UPPER RIDGE. HOWEVER... STORMS MAY DEVELOP ALONG NWWD EXTENTION OF FRONT OVER THE CNTRL HIGH PLAINS AS CAP WEAKENS SUNDAY AFTERNOON. DEWPOINTS IN THE 50S AND STEEP LAPSE RATES SHOULD RESULT IN MLCAPE ON THE ORDER OF 1000 TO 1500 J/KG. MID LEVEL FLOW WILL NOT BE PARTICULARLY STRONG DUE TO PROXIMITY OF UPPER RIDGE. HOWEVER...SELY LOW LEVEL FLOW VEERING TO NWLY 20 KT AT 6 KM SHOULD RESULT IN DEEP LAYER SHEAR MARGINALLY SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS AS ACTIVITY DEVELOPS SEWD THROUGH MID EVENING. ...PACIFIC NW AND NRN ROCKIES AREA... EXTENT AND MAGNITUDE OF SEVERE THREAT IN THIS AREA WILL DEPEND ON TIMING OF IMPULSES AND DEGREE OF CLOUD COVER. LOW LEVEL DEWPOINTS IN THE UPPER 40S TO LOWER 50S WILL PERSIST WITHIN THE STEEP LAPSE RATE ENVIRONMENT WITH MLCAPE ON THE ORDER OF 400 TO 800 J/KG BY AFTERNOON. STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN...POSSIBLY AIDED BY DEEP LAYER LARGER SCALE ASCENT ASSOCIATED WITH NWD ADVANCING IMPULSES. STRONG MIDDLE AND UPPER SLY FLOW WILL PERSIST OVER THIS REGION CONTRIBUTING TO FAVORABLE VERTICAL SHEAR PROFILES FOR SUPERCELLS. THERMODYNAMIC ENVIRONMENT SHOULD SUPPORT POTENTIAL FOR BOTH LARGE HAIL AND DAMAGING WIND DURING THE AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 05/20/2006  From swody2 at goshenarc.org Sat May 20 06:34:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 02:34:38 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200631 SWODY2 SPC AC 200630 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0130 AM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE MIDDLE MS VALLEY AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE PACIFIC NW AND NRN ROCKIES... ...SYNOPSIS... PATTERN WILL CHANGE LITTLE THROUGH SUNDAY WITH AN UPPER LOW DOMINATING MUCH OF THE ERN HALF OF THE COUNTRY AND AN UPPER RIDGE OVER THE ROCKIES. A SERIES OF SHORTWAVE TROUGHS EMANATING FROM ERN PACIFIC UPPER LOW WILL LIFT NWD THROUGH CA AND THE PACIFIC NW. AT THE SURFACE A FRONT WILL SETTLE SWD INTO THE TN VALLEY AND EXTEND WNWWD THROUGH SRN MO...NRN OK AND NWWD INTO THE CNTRL HIGH PLAINS. ...SERN KS...NERN OK THROUGH THE LOWER MS AND WRN TN VALLEYS... A RELATIVELY MOIST BOUNDARY LAYER WILL PERSIST NEAR FRONT FROM THE TN AND MID MS VALLEYS INTO NRN OK AND PARTS OF THE CNTRL PLAINS. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...THE ATMOSPHERE SHOULD BECOME MODERATELY UNSTABLE BY AFTERNOON. THE FRONT WILL LIKELY SERVE AS A FOCUS FOR THUNDERSTORMS THIS PERIOD. A FEW STORMS MAY BE IN PROGRESS EARLY SUNDAY IN WARM ADVECTION REGIME N OF FRONT OVER PART OF THE LOWER MS VALLEY. THE NATURE OF CONVECTIVE EVOLUTION REMAINS A BIT UNCERTAIN AT THIS TIME GIVEN EXPECTED LIMITED DEEP LAYER FORCING. HOWEVER...SOME POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE BOUNDARY AS CAP WEAKENS SUNDAY AFTERNOON. OTHER STORMS MAY DEVELOP OVERNIGHT FROM THE SRN PLAINS INTO THE LOWER MS VALLEY AS THE LOW LEVEL JET STRENGTHENS. ELY LOW LEVEL FLOW NEAR THE FRONT VEERING TO WNWLY 25 TO 30 KT AT 6 KM SUGGEST VERTICAL SHEAR WILL BE AT LEAST MARGINALLY FAVORABLE FOR ORGANIZED STORMS. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS. ...CNTRL HIGH PLAINS... THIS AREA WILL BE IN CLOSER PROXIMITY TO UPPER RIDGE. HOWEVER... STORMS MAY DEVELOP ALONG NWWD EXTENTION OF FRONT OVER THE CNTRL HIGH PLAINS AS CAP WEAKENS SUNDAY AFTERNOON. DEWPOINTS IN THE 50S AND STEEP LAPSE RATES SHOULD RESULT IN MLCAPE ON THE ORDER OF 1000 TO 1500 J/KG. MID LEVEL FLOW WILL NOT BE PARTICULARLY STRONG DUE TO PROXIMITY OF UPPER RIDGE. HOWEVER...SELY LOW LEVEL FLOW VEERING TO NWLY 20 KT AT 6 KM SHOULD RESULT IN DEEP LAYER SHEAR MARGINALLY SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES. ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS AS ACTIVITY DEVELOPS SEWD THROUGH MID EVENING. ...PACIFIC NW AND NRN ROCKIES AREA... EXTENT AND MAGNITUDE OF SEVERE THREAT IN THIS AREA WILL DEPEND ON TIMING OF IMPULSES AND DEGREE OF CLOUD COVER. LOW LEVEL DEWPOINTS IN THE UPPER 40S TO LOWER 50S WILL PERSIST WITHIN THE STEEP LAPSE RATE ENVIRONMENT WITH MLCAPE ON THE ORDER OF 400 TO 800 J/KG BY AFTERNOON. STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN...POSSIBLY AIDED BY DEEP LAYER LARGER SCALE ASCENT ASSOCIATED WITH NWD ADVANCING IMPULSES. STRONG MIDDLE AND UPPER SLY FLOW WILL PERSIST OVER THIS REGION CONTRIBUTING TO FAVORABLE VERTICAL SHEAR PROFILES FOR SUPERCELLS. THERMODYNAMIC ENVIRONMENT SHOULD SUPPORT POTENTIAL FOR BOTH LARGE HAIL AND DAMAGING WIND DURING THE AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 05/20/2006  From swody2 at goshenarc.org Sat May 20 17:31:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 May 2006 13:31:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201728 SWODY2 SPC AC 201727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SAT MAY 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL HIGH PLAINS...SRN PLAINS AND MID MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WA AND ORE... ...MID MS VALLEY... A NORTHWEST FLOW PATTERN WILL LIKELY REMAIN IN PLACE ACROSS THE REGION TONIGHT INTO SUNDAY AS SLY FLOW RETURNS LOW-LEVEL MOISTURE NWD INTO THE MID MS VALLEY. SFC DEWPOINTS IN THE 60S F SHOULD RESULT IN AN AXIS OF MODERATE INSTABILITY BY AFTERNOON EXTENDING FROM THE OZARK PLATEAU EWD ACROSS WRN TN. STORMS SHOULD DEVELOP ALONG THE INSTABILITY AXIS WITH THE GREATEST CONVECTIVE COVERAGE AHEAD OF ANY SHORTWAVE TROUGH THAT CROSSES THE REGION IN THE AFTERNOON AND/OR EVENING. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE REGION SHOW MODERATE TO STRONG VERTICAL SHEAR PROFILES WITH STEEP LAPSE RATES ESPECIALLY ACROSS THE WRN OZARKS WHICH WOULD BE FAVORABLE FOR SUPERCELLS. LARGE HAIL AND WIND DAMAGE WOULD BE LIKELY WITH SUPERCELLS WITH A SEVERE THREAT LIKELY PERSISTING IN THE EVENING WITH ANY MCS THAT ORGANIZES ACROSS THE REGION. ...CNTRL HIGH PLAINS... AN UPPER-LEVEL RIDGE WILL SLOWLY MOVE EWD ACROSS THE HIGH PLAINS SUNDAY WITH A LEE TROUGH IN PLACE. AS CONVERGENCE INCREASES ALONG THE TROUGH/DRYLINE...SCATTERED CONVECTIVE INITIATION WILL BE LIKELY. STORMS SHOULD GRADUALLY INTENSIFY MOVING EWD ACROSS THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE HIGH PLAINS SHOW MODERATE VERTICAL SHEAR PROFILES WITH STRONG DIRECTIONAL SHEAR BELOW 500 MB WHICH WILL BE FAVORABLE FOR SUPERCELLS. STEEP LAPSE RATES AND THE MODERATE INSTABILITY SUGGEST HAIL WILL BE LIKELY WITH THE STRONGER STORMS. IN ADDITION...LARGE SFC TEMP-DEWPOINT SPREADS AND THE STRENGTHENING LOW-LEVEL JET MAY ALSO ENHANCE THE WIND DAMAGE POTENTIAL WITH THE STRONGER CONVECTIVE CLUSTERS IN THE EVENING. ...NWRN US... A HIGH PLAINS UPPER-LEVEL RIDGE IS FORECAST TO SLOWLY MOVE EWD AS SLY FLOW ALOFT CONTINUES ACROSS THE NWRN STATES. AT THE LOWER ELEVATIONS...SFC DEWPOINTS IN THE 50S F ACROSS NE ORE/SE WA AND IN WRN/CNTRL MT SHOULD BE FAVORABLE FOR POCKETS OF MODERATE INSTABILITY BY MIDDAY. IN ADDITION...FORECAST SOUNDINGS SHOW STRONG DIRECTIONAL SHEAR PROFILES RESULTING IN MODERATE TO STRONG VERTICAL SHEAR PROFILES SUGGESTING SUPERCELLS WILL BE POSSIBLE WITH STORMS THAT INITIATE SUNDAY AFTERNOON. STEEP LAPSE RATES AND INVERTED V-SOUNDINGS WILL MAKE HAIL AND WIND DAMAGE LIKELY WITH THE STRONGER CELLS DURING THE LATE AFTERNOON AND EARLY EVENING. ..BROYLES.. 05/20/2006  From swody2 at goshenarc.org Sun May 21 06:19:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 May 2006 02:19:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210616 SWODY2 SPC AC 210614 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 AM CDT SUN MAY 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT BASIN AREA THROUGH THE CNTRL ROCKIES AND THE CNTRL HIGH PLAINS... ...SYNOPSIS... UPPER PATTERN WILL REMAIN CHARACTERIZED BY AN UPPER LOW OVER THE ERN STATES AND AN UPPER RIDGE OVER THE CNTRL PART OF THE COUNTRY. THE STRONG SHORTWAVE TROUGH OVER THE ERN PACIFIC WILL EJECT NEWD INTO THE GREAT BASIN...REACHING THE CNTRL ROCKIES MONDAY EVENING. A STRONG COLD FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH THROUGH THE GREAT BASIN. THIS BOUNDARY WILL REACH THE CNTRL AND NRN HIGH PLAINS LATE MONDAY NIGHT. FARTHER EAST A QUASISTATIONARY FRONT WILL EXTEND FROM THE CAROLINAS WNWWD THROUGH THE MIDDLE MS VALLEY THEN NWWD INTO THE CNTRL AND NRN PLAINS. ERN PORTIONS OF THE FRONT MAY SETTLE SLOWLY SWD THROUGH THE CAROLINAS. ...NRN AZ THROUGH UT...CO AND THE CNTRL HIGH PLAINS... MOISTURE WILL REMAIN LIMITED FROM THE GREAT BASIN INTO THE CNTRL ROCKIES. HOWEVER...STEEP LAPSE RATES AND STRONG SURFACE HEATING WILL PROMOTE AT LEAST MARGINAL INSTABILITY WITH MLCAPE AROUND 500 J/KG. ASCENT ASSOCIATED WITH EJECTING SHORTWAVE TROUGH WITHIN THE STEEP LAPSE RATE ENVIRONMENT AND FRONTAL FORCING WILL PROMOTE THE DEVELOPMENT OF HIGH BASED STORMS THAT WILL SPREAD THROUGH PARTS OF AZ INTO UT DURING THE DAY. DEEP INVERTED-V BOUNDARY LAYERS SUGGEST PRIMARY THREAT WILL BE ISOLATED DAMAGING WIND AS CLUSTERS OF STORMS SPREAD NEWD. OTHER STORMS MAY DEVELOP OVER THE HIGHER TERRAIN OF CO PROMOTED BY STRONG SURFACE HEATING AND OROGRAPHIC FORCING. VERTICAL SHEAR PROFILES WILL INCREASE DURING THE AFTERNOON...ESPECIALLY OVER THE WRN HALF OF CO AS THE MID LEVEL JET LIFTS NEWD. THESE STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED DAMAGING WIND AND HAIL. ADDITIONAL STORMS MAY DEVELOP FARTHER EAST OVER THE CNTRL HIGH PLAINS BY LATE AFTERNOON INTO THE EVENING ALONG THE WRN EDGE OF THE DEEPER MOISTURE WHERE MIXING AND SURFACE HEATING WILL WEAKEN CAP. INSTABILITY WILL BE STRONGER IN THIS AREA OWING TO RICHER LOW LEVEL MOISTURE WITH MLCAPE FROM 1000 TO 1500 J/KG. VERTICAL SHEAR WILL ONLY BE MARGINALLY SUPPORTIVE OF ORGANIZED STORMS DURING THE AFTERNOON...BUT WILL LIKELY INCREASE INTO THE EVENING AS MID LEVEL JET LIFTS NEWD THROUGH CO. ISOLATED DAMAGING WIND AND LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ACTIVITY MAY PERSIST INTO THE EVENING AS ASCENT ACCOMPANYING EJECTING SHORTWAVE TROUGH SPREADS EWD INTO THE HIGH PLAINS. ...TN VALLEY THROUGH SC... A STRONG MID LEVEL JET WILL MOVE THROUGH THE MID ATLANTIC AND OFFSHORE MONDAY NIGHT WITH HEIGHT RISES AND WEAKENING BOUNDARY LAYER FLOW IN ITS WAKE. THE ATMOSPHERE MAY ONCE AGAIN BECOME MODERATELY UNSTABLE ALONG AND S OF SURFACE FRONT ACROSS PARTS OF THE TN VALLEY THROUGH SC. HOWEVER...THE WEAKENING LOW LEVEL FLOW WILL LIMIT CONVERGENCE AND MAY SERVE AS AN OVERALL LIMITING FACTOR FOR SEVERE WEATHER. STILL...POTENTIAL WILL EXIST FOR STORMS TO REDEVELOP AND INTENSIFY IN VICINITY OF THE FRONT. A FEW STRONG STORMS CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE THE PRIMARY THREATS THROUGH EARLY EVENING. ..DIAL.. 05/21/2006  From swody2 at goshenarc.org Sun May 21 17:23:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 May 2006 13:23:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211720 SWODY2 SPC AC 211718 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1218 PM CDT SUN MAY 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS...CNTRL ROCKIES AND INTERMOUNTAIN WEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN ATLANTIC SEABOARD AND THE SRN APPALACHIAN MTNS... ...HIGH PLAINS/CNTRL ROCKIES AND INTERMOUNTAIN WEST... A VIGOROUS UPPER-LEVEL TROUGH IS FORECAST TO MOVE NEWD ACROSS THE SWRN U.S. MONDAY. AHEAD OF THE SYSTEM...STRONG LARGE-SCALE ASCENT WILL SPREAD NEWD ACROSS THE FOUR CORNERS REGION INTO CO DURING THE AFTERNOON AND EVENING. ALTHOUGH INSTABILITY IS FORECAST TO BE RELATIVELY WEAK ACROSS THE REGION MONDAY...THE STRONG LIFT...STEEP LAPSE RATES AND STRONG VERTICAL SHEAR ASSOCIATED WITH THE UPPER-TROUGH SHOULD BE ENOUGH FOR SCATTERED STRONG THUNDERSTORM DEVELOPMENT. A POTENTIAL FOR HAIL AND ISOLATED WIND DAMAGE WILL BE POSSIBLE WITH STORMS THAT DEVELOP NEAR AREAS WITH ENHANCED INSTABILITY IN THE LATE AFTERNOON AND/OR EARLY EVENING. FURTHER NORTHEAST ACROSS CO AND THE HIGH PLAINS...A LEAD SHORTWAVE TROUGH IS FORECAST TO MOVE NEWD INTO THE HIGH PLAINS AHEAD OF THE APPROACHING UPPER-LEVEL SYSTEM. THIS COMBINED WITH SFC HEATING SHOULD ALLOW ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND EAST OF THE FRONT RANGE MONDAY AFTERNOON WITH STORMS INCREASING IN COVERAGE DURING THE LATE AFTERNOON AND EVENING. AS STORMS MOVE EWD INTO THE GREATER MOISTURE AND INSTABILITY...A SEVERE THREAT SHOULD DEVELOP DUE TO THE MODERATE VERTICAL SHEAR PROFILES AND STEEP LAPSE RATES IN PLACE. ...SRN ATLANTIC SEABOARD AND SRN APPALACHIAN MTNS... WATER VAPOR IMAGERY AND RUC ANALYSIS CURRENTLY SHOW A SHORTWAVE TROUGH EMBEDDED IN THE NORTHWEST FLOW PATTERN ACROSS THE UPPER MIDWEST. THIS FEATURE IS FORECAST TO MOVE SEWD ACROSS THE MID MS VALLEY INTO THE SRN APPALACHIAN MTNS MONDAY. AT THE SFC...A NEARLY STATIONARY FRONT SHOULD BE IN PLACE FROM NRN AL EXTENDING ESEWD ACROSS NRN GA INTO SC. THE LARGE-SCALE ASCENT AHEAD OF THE APPROACHING SHORTWAVE COMBINED WITH WARMING SFC TEMPS DURING THE DAY...SHOULD RESULT IN SCATTERED THUNDERSTORM INITIATION ALONG THE BOUNDARY. BY AFTERNOON...SCATTERED THUNDERSTORMS SHOULD DEVELOP AND MOVE ESEWD ACROSS THE REGION. FORECAST SOUNDINGS ACROSS THE REGION MONDAY AFTERNOON SHOW SFC DEWPOINTS IN THE 60S F WITH MODERATE VERTICAL SHEAR PROFILES SUGGESTING A FEW SUPERCELLS WILL BE POSSIBLE. LARGE HAIL AND WIND DAMAGE WOULD LIKELY BE THE PRIMARY THREATS AS AN MCS DEVELOPS AND MOVES EWD ACROSS SC IN THE LATE AFTERNOON AND EVENING. ..BROYLES.. 05/21/2006  From swody2 at goshenarc.org Mon May 22 06:15:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 May 2006 02:15:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220610 SWODY2 SPC AC 220609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT MON MAY 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND NRN PLAINS AND MIDDLE MS VALLEY AREAS... ...SYNOPSIS... A STRONG SHORTWAVE TROUGH NOW MOVING INTO SRN CA WILL EJECT NEWD INTO THE CNTRL PLAINS TUESDAY RESULTING IN DE AMPLIFICATION OF THE UPPER RIDGE. A COLD FRONT WILL ACCOMPANY THIS FEATURE. BY MID AFTERNOON THE FRONT SHOULD EXTEND FROM A SURFACE LOW IN SD SWD THROUGH CNTRL NEB AND INTO WRN KS. DRYLINE WILL STRETCH FROM WRN TX NWD THROUGH N CNTRL KS. THE COLD FRONT WILL OVERTAKE THE KS DRYLINE AS IT CONTINUES EWD OVERNIGHT. A WEAK FRONT WILL PERSIST FROM THE SERN STATES NWWD THROUGH THE MID MS VALLEY...ERN NEB TO THE SURFACE LOW IN SD. A COLD FRONT WILL MOVE FROM ERN MT INTO ND AS AN IMPULSE EJECTS NEWD THROUGH MT INTO SWRN CANADA. ...CNTRL PLAINS THROUGH PORTIONS OF THE MIDDLE MS VALLEY... CORRIDOR OF MID 60S DEWPOINTS NOW RESIDING IN VICINITY OF FRONT FROM KS INTO THE LOWER MS VALLEY WILL ADVECT NWD MONDAY INTO MONDAY NIGHT AS THE LOW LEVEL JET STRENGTHENS IN ASSOCIATION WITH DEVELOPING LEE TROUGH. STRENGTHENING 700-500 MB FLOW ACCOMPANYING THE EJECTING UPPER TROUGH WILL ADVECT STEEP MID LEVEL LAPSE RATES EWD INTO THE CNTRL PLAINS ABOVE THE MOIST AXIS. THIS WILL RESULT IN MODERATE INSTABILITY AS AFTERNOON HEATING COMMENCES WITH MLCAPE AROUND 2000 J/KG POSSIBLE FROM KS INTO NEB. STORMS ARE EXPECTED TO REDEVELOP AND INTENSIFY ALONG AND AHEAD OF THE FRONT WITHIN ZONE OF INCREASING DEEP LAYER ASCENT ASSOCIATED WITH EJECTING SHORTWAVE TROUGH DURING THE AFTERNOON. VERTICAL SHEAR PROFILES WILL INCREASE AS A MID LEVEL JET ROTATES ENEWD THROUGH BASE OF UPPER TROUGH RESULTING IN FAVORABLE SHEAR PROFILES FOR ORGANIZED STORMS INCLUDING SUPERCELLS. SOME STORMS MAY EVENTUALLY EVOLVE INTO LINES AND CLUSTERS...ESPECIALLY ACROSS PARTS OF NEB INTO SD. LARGE HAIL AND DAMAGING WIND MAY ACCOMPANY THE STRONGER STORMS. ISOLATED TORNADOES MAY ALSO BE POSSIBLE...ESPECIALLY AS THE LOW LEVEL JET STRENGTHENS FROM LATE AFTERNOON INTO THE EVENING. ACTIVITY WILL SPREAD INTO PARTS OF THE MIDDLE MS VALLEY DURING THE EVENING WITH A CONTINUED THREAT OF SEVERE WEATHER. STORMS MAY ALSO DEVELOP SWD INTO KS WHERE SHEAR PROFILES WILL BE FAVORABLE FOR SUSTAINED DISCRETE SUPERCELLS. STORMS MAY BE MORE ISOLATED WITH SWD EXTENT WHERE DEEP LAYER FORCING WILL BE WEAKER AND CAP WILL BE STRONGER. LARGE HAIL AND ISOLATED TORNADOES WILL BE POSSIBLE WITH ANY STORMS THAT MANAGE TO DEVELOP IN KS. PORTIONS OF THE CNTRL PLAINS MAY NEED TO BE UPGRADED TO MODERATE RISK IN LATER OUTLOOKS. ...NRN HIGH PLAINS... WEAK VERTICAL SHEAR IN THIS REGION MAY SERVE AS A LIMITING FACTOR FOR AN ORGANIZED SEVERE THREAT. HOWEVER...LOW LEVEL DEWPOINTS IN THE UPPER 50S TO AROUND 60 ARE EXPECTED TO ADVECT NWD INTO THIS REGION BENEATH STEEP LAPSE RATES. WHERE SURFACE HEATING OCCURS...MODERATE INSTABILITY WILL LIKELY DEVELOP DURING THE AFTERNOON. STORMS SHOULD REDEVELOP AND INTENSIFY IN VICINITY OF THE EWD ADVANCING FRONT. STORM MODE WILL LIKELY BE MULTICELLULAR GIVEN THE EXPECTED WEAK VERTICAL SHEAR. HOWEVER....STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT FOR HAIL AND DAMAGING WIND GUSTS AS ACTIVITY SPREADS EWD THROUGH ERN MT AND WRN ND DURING THE AFTERNOON. ..DIAL.. 05/22/2006  From swody2 at goshenarc.org Mon May 22 17:36:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 May 2006 13:36:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221733 SWODY2 SPC AC 221732 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CDT MON MAY 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN AND CENTRAL PLAINS.... ...SYNOPSIS... NEGATIVELY TILTED MID/UPPER LEVEL SHORTWAVE TROUGH OVER SRN CA AT THIS TIME IS EXPECTED TO LIFT NEWD INTO WY/CO BY START OF THE DAY2 PERIOD. FROM THERE...THE MAJORITY OF THE ENSEMBLE SOLUTIONS CLOSE MID/UPPER LOW OVER ERN SD BY TUESDAY EVENING WHILE HOLDING A SW-NE MID LEVEL RIDGE ACROSS THE SWRN AND S CENTRAL U.S. WITH THIS SOLUTION IN MIND...LOOKS LIKE MODELS ARE HAVING DIFFICULTY WITH LOCATION OF SURFACE LOW. SEEMS THAT IF MODELS SETTLE ON CLOSED LOW POSITION OVER ERN SD...THAT A LOW WILL DEVELOP THERE WITH A COLD FRONT MOVING EWD THRU CENTRAL PARTS OF NEB/KS INTO THE OK PANHANDLE. EXPECT LINE/CLUSTER OF SEVERE THUNDERSTORMS TO DEVELOP IN THE WARM SECTOR AHEAD OF THE LOW/COLD FRONT BY LATE AFTERNOON ACROSS CENTRAL/ERN SD INTO CENTRAL AND ERN NEB. ...PARTS OF THE NRN/CENTRAL PLAINS... AIR MASS IS EXPECTED TO DESTABILIZE WITH SBCAPE BETWEEN 2000-3000 J/KG FROM S CENTRAL ND SSEWD THRU THE MO VALLEY INTO NERN KS/NWRN MO BY LATE AFTERNOON. MODELS INDICATE 35-45 KT SLY LOW LEVEL JET BY EVENING THRU ERN KS INTO SERN SD ENHANCING LOW LEVEL MOISTURE CONVERGENCE AHEAD/NEAR REGION OF CYCLOGENESIS. APPROACHING TROUGH WILL BRING WLY TO SWLY 60 KT MID LEVEL FLOW INTO CENTRAL NEB BY EARLY AFTERNOON WITH 70-80 KT AT UPPER LEVELS. THIS IS EXPECTED TO PROVIDE SUFFICIENT DEEP LAYER SHEAR TO SUPPORT SUPERCELLS IN AREA OF STRONG UVVS ENHANCED BY UPPER LEVEL DIVERGENCE. ANALYSIS OF POINT FORECAST SOUNDINGS SHOW THAT AREAS OF SERN SD AND ERN NEB LOOK BEST FOR MAINLY LARGE HAIL AND THREAT FOR ISOLATED TORNADOES NEAR POINT WHERE SURFACE LOW WILL DEVELOP AND AHEAD OF ADVANCING FRONTAL BOUNDARY. MANY OF THE FORECAST DATA INDICATE STEEP LAPSE RATES BETWEEN 8-8.5C/KM AND MUCAPES AROUND 2200 J/KG. THIS DATA ALSO INDICATES 20-30 DEGREE T/TD SPREADS INDICATING ALSO THAT THE ACTIVITY MAY BE ACCOMPANIED BY DAMAGING WINDS. ..MCCARTHY.. 05/22/2006  From swody2 at goshenarc.org Tue May 23 05:07:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 23 May 2006 01:07:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230504 SWODY2 SPC AC 230503 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1203 AM CDT TUE MAY 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE MIDDLE MS VALLEY INTO SERN KS...OK AND NRN AR... ...SYNOPSIS... THE SHORTWAVE TROUGH CURRENTLY EJECTING NEWD INTO THE CNTRL ROCKIES WILL CREST THE MEAN RIDGE POSITION LATE TUESDAY THEN CONTINUE ESEWD THROUGH THE MIDDLE AND UPPER MS VALLEY WEDNESDAY. THIS FEATURE WILL MOVE INTO THE GREAT LAKES AND WRN PORTIONS OF THE OH VALLEY BY LATE WEDNESDAY NIGHT. EARLY WEDNESDAY AN OCCLUDED FRONT WILL EXTEND FROM A SURFACE LOW IN ND SEWD INTO WRN IA THEN SWWD AS A COLD FRONT THROUGH ERN KS AND NWRN OK. THIS FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH THROUGH THE MS VALLEY DURING THE DAY AND TRAIL SWWD THROUGH OK BY EARLY EVENING. A QUASISTATIONARY FRONT WILL PERSIST FROM THE SERN U.S. NWWD INTO THE MIDDLE MS VALLEY WHERE IT WILL INTERSECT THE COLD FRONT. ...MIDDLE MS VALLEY THROUGH SERN KS...OK AND NRN AR... RICHER LOW LEVEL MOISTURE NOW RESIDING NEAR QUASISTATIONARY FRONT OVER THE LOWER MS VALLEY INTO PARTS OF THE SRN PLAINS WILL SHIFT NEWD INTO THE MIDDLE MS VALLEY AS A SWLY LOW LEVEL JET STRENGTHENS W OF RETREATING SURFACE RIDGE. A BAND OF STRONGER 700-500 MB WLY FLOW ACCOMPANYING THE SHORTWAVE TROUGH WILL ADVECT STEEP MID LEVEL LAPSE RATES EWD THROUGH THE CNTRL/SRN PLAINS INTO THE MIDDLE MS VALLEY ABOVE THE MOIST AXIS. THIS SHOULD CONTRIBUTE TO MODERATE INSTABILITY AS THE BOUNDARY LAYER WARMS WITHIN THE PRE-FRONTAL WARM SECTOR FROM PARTS OF IA AND MO INTO SERN KS AND OK. A FEW STORMS MAY BE ONGOING EARLY WEDNESDAY WITHIN WARM ADVECTION REGIME OVER PART OF THE MIDDLE MS VALLEY. THESE STORMS WILL LIKELY CONTINUE SEWD AS THE LOW LEVEL JET VEERS. IF STORMS PERSIST INTO THE LATE MORNING OR AFTERNOON...IT IS POSSIBLE THAT THIS ACTIVITY COULD INTENSIFY AS IT INGESTS INCREASINGLY HIGHER THETA-E AIR FROM THE DESTABILIZING WARM SECTOR. OTHER STORMS WILL LIKELY DEVELOP ALONG THE COLD FRONT FROM PARTS OF MO SWWD INTO SERN KS AND OK. VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG OWING TO THE SOMEWHAT UNIDIRECTIONAL NATURE OF THE DEEP LAYER FLOW AND MODEST AMBIENT MID LEVEL FLOW. HOWEVER...THE 0-6 KM SHEAR MAY BECOME AT LEAST MARGINALLY SUFFICIENT FOR SUPERCELL STRUCTURES OVER PARTS OF MO INTO SERN KS AND OK WHERE A 40 KT WNWLY MID LEVEL JET WILL SPREAD SEWD ABOVE THE WSWLY LOW LEVEL FLOW. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS THROUGH MID EVENING. ACTIVITY WILL SPREAD EWD TOWARD THE OH AND TN VALLEYS DURING THE EVENING AND OVERNIGHT WITH A GRADUAL DECREASE IN SEVERE THREAT. ..DIAL.. 05/23/2006  From swody2 at goshenarc.org Tue May 23 17:06:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 23 May 2006 13:06:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231703 SWODY2 SPC AC 231702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 PM CDT TUE MAY 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS WED AFTN INTO THU MORNING ACROSS THE MID MS VALLEY INTO THE WRN OHIO VALLEY.... ...SYNOPSIS... PROGRESSIVE MID/UPPER LEVEL LOW WILL MOVE FROM THE ERN NRN PLAINS SEWD INTO THE SWRN UPPER GREAT LAKES DURING THE PERIOD AS STRONG VORTEX CURRENTLY NEAR 46N 138W SENDS SEVERAL SHORTWAVES NEWD ACROSS THE PACIFIC NORTHWEST. CONVECTION IS EXPECTED IN THE VICINITY OF MID/UPPER LOW AS WELL AS AHEAD OF THE FRONTAL BOUNDARY THAT WILL TRAVEL EWD EXTENDING FROM SERN ND SWD THROUGH ERN NEB THEN SWWD INTO THE OK PANHANDLE BY THE START OF THE PERIOD. REMNANTS OF AN MCS COULD BE OVER IA/NWRN MO TO BEGIN THE PERIOD WITH CONVECTIVE BOUNDARIES ACROSS ERN IA INTO NERN AND CENTRAL MO TO FOCUS LATER CONVECTIVE DEVELOPMENT. ...MID MS VALLEY INTO WRN OHIO VALLEY... MOIST AND UNSTABLE AIR MASS IS ALREADY IN PLACE FROM THE PLAINS INTO THE MO VALLEY AND WILL SPREAD EWD THROUGH THE EARLY PART OF THE PERIOD AS DAY1 CONVECTION AND FRONTAL BOUNDARY MOVES EWD TOWARDS THE MS VALLEY AND SURFACE RIDGE MOVES TOWARDS THE MID ATLANTIC REGION. SURFACE DEW POINTS ARE EXPECTED TO BE IN THE MID/UPPER 60S INTO MO/IL AND PARTS OF IND TOMORROW AS LOW LEVEL FLOW BEGINS AT 35-45 KT FROM CENTRAL OK NEWD INTO NWRN IL...THEN SHIFTS INTO THE MID MS VALLEY BY EVENING. 50-60 KT NWLY MID LEVEL FLOW WILL FOLLOW BEHIND MID/UPPER LEVEL LOW PROVIDING FAVORABLE DEEP LAYER SHEAR IN VICINITY OF STRONG LOW LEVEL CONVERGENCE TO SUPPORT SEVERE THUNDERSTORMS ALONG/AHEAD OF ADVANCING COLD FRONT ENHANCED BY OLD CONVECTIVE BOUNDARIES FROM PREVIOUS DAY CONVECTION. AIR MASS AHEAD OF COLD FRONTAL BOUNDARY IS EXPECTED TO DESTABILIZE WITH MUCAPES AROUND 3000 J/KG BY AFTERNOON ACROSS PARTS OF ERN IA/WRN IL/NERN MO. THUS...WOULD EXPECT SEVERE THUNDERSTORMS REDEVELOPING ACROSS THIS REGION WEDNESDAY AFTERNOON WITH MAIN THREATS BEING LARGE HAIL AND DAMAGING WINDS. GIVEN THAT DEEP LAYER SHEAR IS EXPECTED TO BE 30-40 KT...WOULD NOT RULE OUT A FEW ISOLATED TORNADOES IN THE VICINITY OF CONVECTIVE BOUNDARIES. SEVERE ACTIVITY IS EXPECTED TO BECOME MORE WIDESPREAD ACROSS PARTS OF MO/IL AND IND OVERNIGHT AS CONVECTION FORMS INTO ANOTHER MCS WITH MAIN THREAT BEING DAMAGING WINDS. ..MCCARTHY.. 05/23/2006  From swody2 at goshenarc.org Wed May 24 05:12:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 24 May 2006 01:12:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240509 SWODY2 SPC AC 240508 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1208 AM CDT WED MAY 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE OH VALLEY INTO THE TN AND LOWER MS VALLEYS... ...SYNOPSIS... UPPER LOW NOW OVER THE NRN PLAINS WILL CREST THE UPPER RIDGE AND CONTINUE SEWD THROUGH THE MID MS VALLEY INTO THE OH AND TN VALLEYS THURSDAY. ACCOMPANYING FRONT SHOULD EXTEND FROM A SURFACE LOW OVER THE WRN GREAT LAKES SWWD THROUGH MO INTO NWRN OK EARLY THURSDAY. THIS BOUNDARY WILL MOVE SEWD INTO THE OH VALLEY DURING THE DAY WITH TRAILING PORTION BECOMING STATIONARY ACROSS AR AND CNTRL OK THURSDAY NIGHT. ...OH AND TN VALLEYS THROUGH NRN AR AND SRN MO... LOW LEVEL FLOW WILL VEER TO WLY AS THE SHORTWAVE TROUGH ADVANCES ESEWD. THIS WILL CONTRIBUTE TO THE EWD ADVECTION OF RICHER BOUNDARY LAYER MOISTURE WITH LOW TO MID 60S DEWPOINTS INTO THE TN AND OH VALLEYS. AREAS OF PRE-FRONTAL CONVECTION MAY BE IN PROGRESS WITHIN PORTIONS OF THE WARM SECTOR EARLY THURSDAY AND WILL SPREAD SEWD DURING THE DAY. THE EVOLUTION OF THE EARLY ACTIVITY IS UNCERTAIN AT THIS TIME. HOWEVER...DESTABILIZATION IS EXPECTED WHERE CLEARING DEVELOPS IN THE WAKE OF THE MORNING STORMS WITH AN AXIS OF MLCAPE FROM 1500 TO 2000 J/KG JUST AHEAD OF THE FRONT. GIVEN HEIGHT FALLS ACCOMPANYING SEWD ADVANCING SHORTWAVE TROUGH AND WEAK CAP...STORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF THE FRONT FROM PARTS OF THE OH VALLEY SWWD INTO TN AND LOWER MS VALLEYS. KINEMATIC PROFILES ACCOMPANYING THE SHORTWAVE TROUGH WILL BE SUFFICIENT FOR SOME ORGANIZED STORM STRUCTURES INCLUDING BOWING LINE SEGMENTS AS WELL AS A FEW SUPERCELLS DURING THE AFTERNOON. SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING SUPPORTED BY AN INTENSIFYING LOW LEVEL JET. ..DIAL.. 05/24/2006  From swody2 at goshenarc.org Wed May 24 17:33:43 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 24 May 2006 13:33:43 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241730 SWODY2 SPC AC 241729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT WED MAY 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH/TN/MID MS VALLEYS... ...SYNOPSIS... SLOWLY PROGRESSIVE UPPER PATTERN IS FORECAST ACROSS THE NRN HALF OF THE CONUS...WITHIN ZONE OF STRONGER UPPER FLOW. UPPER LOW/SHORT-WAVE TROUGH INITIALLY FORECAST OVER THE MID/UPPER MS VALLEY REGION WILL MOVE ESEWD ACROSS THE GREAT LAKES/OH AND TN VALLEYS WITH TIME...ACCOMPANIED BY A CYCLONIC ARC OF MODERATELY-STRONG DEEP-LAYER FLOW. MEANWHILE...A SECOND UPPER LOW OFF THE BRITISH COLUMBIA COAST -- WITHIN LARGER-SCALE TROUGH -- IS FORECAST TO MOVE SEWD TOWARD THE PAC NW COAST WITH TIME...WHILE ACCOMPANYING UPPER JET SPREADS ACROSS THE PAC NW INTO THE NRN ROCKIES THROUGH THE PERIOD. ...OH/TN/MID MS VALLEY REGION... STORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF THE OH/TN VALLEY REGION...WITHIN ZONE OF LOW-LEVEL WARM ADVECTION AHEAD OF UPPER TROUGH. AS THIS CONVECTION SPREADS SEWD ACROSS THE OH/TN VALLEYS DURING THE DAY -- POSSIBLY ACCOMPANIED BY A LOW-END SEVERE THREAT...DAYTIME HEATING SHOULD ALLOW AIRMASS TO DESTABILIZE ACROSS THE MIDWEST IN THE WAKE OF INITIAL CONVECTION. AS UPPER FEATURE SHIFTS SEWD ALONG WITH ACCOMPANYING COLD FRONT...EXPECT NEW STORMS TO INITIATE DURING THE AFTERNOON -- LIKELY ACROSS THE MID OH VALLEY REGION INITIALLY. WITH SUFFICIENT INSTABILITY ANTICIPATED...EXPECT VIGOROUS UPDRAFTS...LIKELY EVOLVING INTO AN ORGANIZED/LINEAR MCS WITH TIME. GIVEN MODERATELY-STRONG/ROUGHLY UNIDIRECTIONAL FLOW THROUGH THE LOWER/MIDDLE TROPOSPHERE...POTENTIAL FOR AN ORGANIZED DAMAGING WIND EVENT APPEARS TO EXIST. WILL MAINTAIN ONLY A SLIGHT RISK THIS FORECAST AS SOME QUESTIONS REMAIN REGARDING DEGREE OF AIRMASS DESTABILIZATION IN THE WAKE OF INITIAL CONVECTION OVER THE THREAT AREA. AREA MAY BE UPGRADED IN LATER FORECASTS. ...MT/NWRN WY/SERN ID... STRONG SWLY FLOW ALOFT IS FORECAST ACROSS THIS AREA WITHIN TIGHT UPPER HEIGHT GRADIENT BETWEEN RIDGE OVER THE CENTRAL AND SRN ROCKIES AND APPROACHING UPPER LOW/TROUGH MOVING INTO THE PAC NW. DAYTIME HEATING SHOULD CONTRIBUTE MARGINAL/HIGH-BASED INSTABILITY ACROSS THIS REGION...WITH SURFACE LOW/FRONT LYING ACROSS THE AREA COMBINED WITH LARGE-SCALE UVV AHEAD OF APPROACHING TROUGH LIKELY SUPPORTING SCATTERED AFTERNOON STORM DEVELOPMENT. DESPITE LIMITED INSTABILITY...COMBINATION OF DEEP BOUNDARY LAYER AND STRENGTH OF DEEP-LAYER WIND FIELD SHOULD SUPPORT A THREAT FOR DAMAGING WIND GUSTS AND/OR HAIL WITH A FEW STRONGER CELLS. THREAT SHOULD DIMINISH THROUGH THE EVENING COINCIDENT WITH DIURNAL STABILIZATION. ..GOSS.. 05/24/2006  From swody2 at goshenarc.org Fri May 26 06:13:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 26 May 2006 02:13:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260610 SWODY2 SPC AC 260609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT FRI MAY 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN HIGH PLAINS EWD ACROSS ND INTO NRN MN... ...SYNOPSIS... MODELS CONTINUE TO SHOW THE UPPER PATTERN EVOLVING INTO A LONG WAVE TROUGH IN THE WEST AND A BUILDING RIDGE IN THE EAST. MID/UPPER LEVEL TROUGH...NOW LOCATED OVER THE GREAT LAKES/OH VALLEY...WILL MOVE EWD OFF THE ERN SEABOARD. A FEW MID LEVEL IMPULSES EMANATING FROM THE BASE OF THE WRN TROUGH ARE EXPECTED TO TRACK NEWD WITHIN BAND OF STRONG SWLY MID LEVEL FLOW ACROSS THE CENTRAL ROCKIES TO NRN PLAINS AND INTO SRN CANADA. IN THE LOW LEVELS...A SURFACE LOW LOCATED OVER WY AT 12Z SATURDAY IS EXPECTED TO TRACK ENE TOWARD THE WRN DAKOTAS BY LATE SATURDAY AFTERNOON AND MOVE ACROSS ND SATURDAY NIGHT. A BAROCLINIC ZONE WILL EXTEND NEWD FROM THE WY LOW ACROSS ND INTO SRN MANITOBA WITH THIS BOUNDARY REMAINING QUASISTATIONARY THROUGH DAY 2...AS A COLD FRONT SPREADS EWD FROM THE NRN HIGH PLAINS INTO ND/SD/NEB. A LEE TROUGH/ DRY LINE IS EXPECTED TO EXTEND SWD ALONG THE HIGH PLAINS. MEANWHILE...A SURFACE BOUNDARY IS PROGGED TO EXTEND FROM THE SE STATES NWWD ACROSS THE TN/MID MS VALLEY INTO IA...AND SHOULD BE THE FOCUS FOR SATURDAY AFTERNOON THUNDERSTORMS. ...PARTS OF NRN HIGH PLAINS EWD TO NRN MN... SLY LOW LEVEL FLOW EXPECTED ACROSS THE PLAINS STATES FROM DAY 1 INTO DAY 2 WILL ALLOW MOISTURE TO RETURN NWD INTO THE NORTH CENTRAL STATES WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S REACHING AS FAR NORTH AS MUCH OF ND/MN INTO ADJACENT PARTS OF SRN CANADA. ELEVATED MIXED LAYER IS EXPECTED TO SPREAD EWD INTO THE PLAINS ATOP THE MOISTURE RETURN...AND EFFECTIVELY CAP MUCH OF THE PLAINS STATES...LIMITING THUNDERSTORM DEVELOPMENT ALONG THE DRY LINE. HOWEVER...STEEP LAPSE RATES WILL RESULT IN STRONG INSTABILITY DEVELOPING FROM TX NWD TO THE NRN PLAINS/UPPER MS VALLEY...WITH THE GREATEST LIKELIHOOD FOR SEVERE THUNDERSTORM DEVELOPMENT FROM NRN MN WWD TO ERN MT/WY. A LEAD MID LEVEL IMPULSE EXPECTED TO BE LOCATED OVER THE ERN DAKOTAS AT 12Z SATURDAY WILL TRACK NEWD ACROSS NRN/CENTRAL MN... REACHING WRN ONTARIO BY SATURDAY EVENING. A MODERATE-STRONG SSWLY LLJ EXTENDING INTO ERN DAKOTAS/WRN MN AT START OF PERIOD SHOULD MAINTAIN ITS STRENGTH AND TRANSLATE NEWD ACROSS MN INTO ONTARIO. A THUNDERSTORM COMPLEX ASSOCIATED WITH THIS LEAD IMPULSE SHOULD BE ONGOING LATE DAY 1/EARLY DAY 2 AND TRACK NEWD ACROSS CENTRAL/NRN MN SATURDAY MORNING/AFTERNOON. INCREASING INSTABILITY/DEEP LAYER SHEAR WILL ALLOW FOR ORGANIZED STORMS/SOME SEVERE ESPECIALLY WITH ANY THAT CAN BECOME SURFACE BASED. ADDITIONAL STORM DEVELOPMENT IS POSSIBLE ACROSS ND ALONG THE SURFACE BOUNDARY...WITH A GREATER LIKELIHOOD FOR AFTERNOON STORMS FARTHER W ACROSS ERN MT INTO WY AS DEEP LAYER ASCENT INCREASES ACROSS THIS REGION AHEAD OF NEXT IMPULSE WITHIN UPSLOPE FLOW. MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS...WITH A SLY LLJ RE-INTENSIFYING ACROSS THE PLAINS SATURDAY NIGHT FOR UPSCALE GROWTH INTO AN MCS ACROSS ERN MT INTO ND. THIS ACTIVITY SHOULD BE MOVING INTO SRN CANADA TOWARD 12Z SUNDAY. ...PARTS OF W TX NWD TO WRN KS... ALTHOUGH MUCH OF THIS REGION IS EXPECTED TO BE CAPPED THROUGH SATURDAY AFTERNOON...STRONG SURFACE HEATING MAY ALLOW THE CAP TO WEAKEN ENOUGH FOR SURFACE PARCELS TO REACH THEIR LFC AT OR AFTER PEAK HEATING. WEAK MID LEVEL IMPULSES MOVING NEWD ACROSS THIS REGION COMBINED WITH STEEP LAPSE RATES/MODERATE INSTABILITY MAY PROVE SUFFICIENT FOR ISOLATED STORMS...WITH DEEP LAYER SHEAR AROUND 30 KTS FAVORING STORM ORGANIZATION. HAIL AND STRONG WIND GUSTS WOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. GIVEN ISOLATED COVERAGE...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES. ..PETERS.. 05/26/2006  From swody2 at goshenarc.org Fri May 26 17:51:10 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 26 May 2006 13:51:10 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261730 SWODY2 SPC AC 261729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI MAY 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...SYNOPSIS... UPPER AIR PATTERN WILL CONTINUE TO EVOLVE WITH A PROMINENT LONGWAVE TROUGH ACROSS THE WRN STATES AND A RIDGE IN THE EAST BY SAT. MINOR SHORTWAVE TROUGHS WILL EJECT NEWD FROM THE TROUGH AND INTO THE CNTRL/NRN PLAINS STATES. AT THE SFC...LEE LOW OVER WY WILL DEEPEN AND TRACK NEWD INTO CNTRL ND BY SAT NIGHT AS A BAROCLINIC ZONE SINKS SEWD FROM THE NRN ROCKIES INTO THE HIGH PLAINS. TO THE S OF THE LOW...A LEE TROUGH/DRYLINE WILL ADVANCE EWD INTO THE CNTRL/SRN PLAINS WHILE A WARM FRONT REDEVELOPS NEWD INTO THE UPPER MS VLY. MEANWHILE...AN OLD FRONT WILL REMAIN QUASISTATIONARY FROM THE MID-SOUTH INTO THE SERN STATES. ...NRN HIGH PLAINS EWD TO NRN MN... A COUPLE OF MCS/S WILL LIKELY BE ONGOING ACROSS THE MID-MO VLY AND OVER THE RED RVR VLY OF ERN ND/NWRN MN AT THE START OF THE PERIOD. STRONGEST LLJ AXIS WILL LIKELY MAINTAIN STORMS ALONG EDGE OF STRONG CAP OVER SRN MANITOBA AND NRN MN INTO SAT AFTN/EVE WITH RISKS FOR LARGE HAIL WHILE THE SRN MCS WEAKENS. UPSTREAM...A SURGE OF WARM TEMPERATURES ALOFT WILL CREATE A CAPPED ENVIRONMENT IN THE WARM SECTOR THROUGH SAT EVE. SFC-BASED TSTMS MAY INITIATE ACROSS CNTRL/NRN ND VCNTY SFC LOW TRACK AND COLD FRONT LATE SAT AFTN...BUT HIGHER PROBABILITIES WILL REMAIN ACROSS SRN CANADA. MORE LIKELY SCENARIO WILL BE FOR TSTMS TO DEVELOP OVERNIGHT ALONG/N OF THE COLD FRONT ACROSS THE NRN PLAINS AS THE UPPER TROUGH EDGES EWD. MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS. IF DAYTIME STORMS CAN MANAGE TO DEVELOP...DAMAGING WINDS AND TORNADOES WILL BE POSSIBLE. BUT...IF CONVECTIVE INITIATION IS DELAYED UNTIL OVERNIGHT N OF THE FRONT...LARGE HAIL WILL BE THE PRIMARY THREAT. ...CNTRL/SRN HIGH PLAINS... THOUGH MUCH OF THIS REGION IS EXPECTED TO BE CAPPED THROUGH SAT AFTN...STRONG SFC HEATING MAY ALLOW THE CAP TO WEAKEN ENOUGH FOR SFC PARCELS TO REACH THEIR LFC AFTN 22Z SAT. WEAK MID LEVEL IMPULSES MOVING NEWD ACROSS THIS REGION COMBINED WITH STEEP LAPSE RATES/MODERATE INSTABILITY MAY PROVE SUFFICIENT FOR ISOLD STORMS...WITH DEEP LAYER SHEAR AROUND 30 KTS FAVORING BRIEF STORM ORGANIZATION. HAIL AND STRONG WIND GUSTS WOULD BE THE PRIMARY THREATS WITH THIS ACTIVITY. GIVEN ISOLATED COVERAGE...ONLY LOW PROBABILITIES ARE JUSTIFIED ATTM. ...MID-SOUTH AND THE SERN STATES... SCT TSTMS ARE EXPECTED ALONG THE OLD FRONT FROM PARTS OF THE MID-SOUTH INTO THE SERN STATES SAT AFTN. WEAK SHEAR WILL FAVOR MULTI-CELL PULSE STORMS WITH PERHAPS ISOLD DAMAGING WIND GUSTS AND MARGINALLY SEVERE HAIL. ..RACY.. 05/26/2006  From swody2 at goshenarc.org Sat May 27 06:07:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 27 May 2006 02:07:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270606 SWODY2 SPC AC 270605 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0105 AM CDT SAT MAY 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...SYNOPSIS... MODELS TEND TO AGREE THAT THE SHORT WAVE TROUGH EXPECTED TO MOVE ESE INTO THE GREAT BASIN DURING DAY 1 PERIOD WILL TRACK NE TOWARD THE NRN HIGH PLAINS/SRN CANADA ON SUNDAY. HOWEVER...SOME DISCREPANCIES EXIST WITH THE AMOUNT OF HEIGHT FALLS /GFS AND ECMWF WEAKER/ WITH THIS SYSTEM AS IT APPROACHES THE NRN HIGH PLAINS/SRN CANADA LATE DAY 2. NONETHELESS...MID LEVEL HEIGHTS ARE EXPECTED TO TIGHTEN WITH RESULTANT STRENGTHENING OF SWLY WINDS AT THIS SAME LEVEL TO AT LEAST 70 KT ACROSS THE NRN PLAINS. IN THE LOW LEVELS...SURFACE TROUGH IS EXPECTED TO MOVE SLOWLY EWD ACROSS THE ERN DAKOTAS/CENTRAL NEB... WHILE A DRY LINE EXTENDING SWD MIXES EWD REACHING CENTRAL KS TO ALONG THE WRN OK/TX BORDER TO THE TX BIG BEND REGION BY SUNDAY AFTERNOON. FARTHER EAST...UPPER RIDGE WILL REMAIN IN PLACE OVER THE ERN U.S. WITH GENERALLY WEAK DEEP LAYER WIND FIELDS. ...NRN PLAINS... AIR MASS ALONG/E OF THE SURFACE TROUGH IS EXPECTED TO REMAIN MOIST AND VERY UNSTABLE WITH MLCAPE 2000-3000 J/KG...BUT STRONG ELEVATED MIXED LAYER WILL LIKELY MAINTAIN THE CAP OVER THE NRN PLAINS THROUGH THE AFTERNOON...LIMITING THE POTENTIAL FOR SURFACE-BASED STORMS. IF STORMS CAN DEVELOP SUNDAY AFTERNOON ALONG THE SURFACE BOUNDARY IN ND/SD...THEN STRONG DEEP LAYER SHEAR WOULD SUPPORT ORGANIZED STORMS/ SUPERCELLS. GREATER LIKELIHOOD FOR THUNDERSTORMS/ATTENDANT SEVERE THREAT SHOULD BE SUNDAY EVENING AS ASCENT INCREASES AHEAD OF APPROACHING GREAT BASIN TROUGH AND ALONG NOSE OF STRENGTHENING CENTRAL PLAINS LLJ. ACTIVITY WILL LIKELY BE LOCATED NORTH OF THE SURFACE BOUNDARY WITH HAIL BEING THE PRIMARY THREAT OVERNIGHT. THUNDERSTORMS WILL ALSO BE POSSIBLE SUNDAY AFTERNOON ALONG THE HIGHER TERRAIN OF ERN WY/NRN CO WITHIN UPSLOPE FLOW REGIME NORTH OF SURFACE BOUNDARY. INSTABILITY IS EXPECTED TO BE WEAK...THUS PRECLUDING A GREATER SEVERE RISK. HOWEVER...SOME OF THIS ACTIVITY MAY SPREAD ENE AND GROW UPSCALE INTO A CLUSTER OF STORMS TRACKING NEWD ACROSS NRN NEB/SD INTO ERN ND/WRN MN LATER SUNDAY NIGHT. ...SRN PLAINS... AIR MASS WILL BE MODERATELY TO VERY UNSTABLE SWD ALONG/E OF THE DRY LINE...BUT SHOULD REMAIN CAPPED UNTIL MID-LATE AFTERNOON. POINT FORECAST SOUNDINGS SUGGEST SURFACE HEATING SHOULD BECOME SUFFICIENT BETWEEN 20-23Z TO ALLOW SURFACE PARCELS TO REACH THEIR LFC. STEEP LAPSE RATES...MLCAPE UP TO 2500 J/KG AND DEEP LAYER SHEAR 25-30 KT SUGGEST POTENTIAL FOR ORGANIZED STORMS. HOWEVER... GIVEN MODEL UNCERTAINTY IN OVERALL STORM COVERAGE...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES INTRODUCED ON THE PREVIOUS DAY 3 OUTLOOK. ...OH VALLEY SWD TO GULF COAST STATES... THUNDERSTORMS WILL BE AGAIN POSSIBLE ALONG THE EXTENT OF THE SURFACE BOUNDARY FROM THE WRN GREAT LAKES SSEWD THROUGH THE LOWER OH/TN VALLEYS TO THE GULF COAST STATES SUNDAY AFTERNOON. MODERATE TO VERY STRONG INSTABILITY EXPECTED ACROSS THESE AREAS AND WEAK DEEP LAYER SHEAR SUGGESTS THE POTENTIAL FOR PULSE-TYPE STORMS. A FEW STORMS MAY BECOME CAPABLE OF PRODUCING A STRONG WIND GUST AND/OR MARGINALLY SEVERE HAIL...BUT WILL NOT INTRODUCE SEVERE PROBABILITIES AT THIS TIME. ..PETERS.. 05/27/2006  From swody2 at goshenarc.org Sat May 27 17:29:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 27 May 2006 13:29:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 271728 SWODY2 SPC AC 271727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT SAT MAY 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN PLAINS... ...SYNOPSIS... BLOCKY UPPER FLOW REGIME WILL EXIST INTO MEMORIAL DAY AS A SPRAWLING UPPER HIGH BECOMES ESTABLISHED ACROSS THE ERN PORTIONS OF THE COUNTRY. THE WRN STATES TROUGH WILL GENERALLY REMAIN IN PLACE WITH THE STRONG SHORTWAVE TROUGH...NOW OVER NV...ROTATING NWD THROUGH THE NRN HIGH PLAINS BY EARLY MEMORIAL DAY. AT THE SFC...THE BAROCLINIC ZONE ASSOCD WITH THE WRN STATES TROUGH WILL EDGE EWD THROUGH THE NRN PLAINS...TRAILING SWWD INTO THE SRN GRT BASIN BY SUNDAY NIGHT. A SERIES OF LOWS WILL MIGRATE ALONG THIS FRONT WITH A DRYLINE TRAILING SWD THROUGH WRN KS...ERN TX PNHDL TO THE TX BIG BEND. ...NRN PLAINS... BOUNDARY LAYER MSTR WILL CONTINUE TO INCREASE THROUGHOUT THE PLAINS STATES BENEATH A STOUT ELEVATED MIXED LAYER THROUGH SUNDAY. THIS WILL CONTRIBUTE TO STRONG POTENTIAL INSTABILITY ALONG/AHEAD OF THE COLD FRONT/DRYLINE OVER THE CNTRL/ERN DAKS AND ERN NEB SUNDAY AFTN. CONFIDENCE IN SFC-BASED TSTM INITIATION IS LOW GIVEN MAGNITUDE OF INHIBITION. BUT...ALL MODELS INDICATE THAT WEAK HEIGHT FALLS WILL SPREAD NEWD FROM THE CNTRL ROCKIES INTO AT LEAST THE WRN DAKS SUNDAY EVE. THIS SHOULD ENHANCE A SFC LOW INVOF DRYLINE/COLD FRONT INTERSECTION DURING PEAK HEATING AND COULD BE THE IMPETUS FOR SFC-BASED INITIATION LATE SUNDAY AFTN OVER NCNTRL NEB OR SCNTRL/SERN SD. OTHERWISE...MORE LIKELY SCENARIO WILL BE FOR DEVELOPMENT OF POST-FRONTAL TSTMS THAT WILL TRANSLATE NEWD THROUGH THE RED RVR VLY OVERNIGHT SUNDAY. ORGANIZED STORMS WILL BE POSSIBLE. GIVEN SFC-BASED STORMS...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY. BUT...THE STRONGER EFFECTIVE SHEAR WILL REMAIN ON THE COLD SIDE OF THE FRONT AND WILL SUPPORT MAINLY LARGE HAIL SUNDAY NIGHT. A LOWER PROBABILISTIC SEVERE THREAT WILL EXIST ALONG THE HIGHER WY/NRN CO HIGH PLAINS AS MOUNTAIN CONVECTION SPREADS NEWD. HERE...ISOLD DAMAGING WINDS OR HAIL MAY ACCOMPANY THE STRONGER STORMS AS THEY DEVELOP NEWD TOWARD THE NRN PLAINS MCS OVERNIGHT. ...SRN PLAINS... ISOLD TSTMS ARE EXPECTED TO DEVELOP INVOF DRYLINE FROM SWRN KS SWD ALONG THE CAPROCK/DRYLINE TO THE LOWER TRANS-PECOS REGION OF SWRN TX. STEEP LAPSE RATES...MLCAPE TO 2500 J/KG AND DEEP LAYER SHEAR 25-30 KT SUGGEST POTENTIAL FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. TSTMS WILL BE VERY SLOW MOVING AND LIKELY DIMINISH AS THE DRYLINE SLOSHES BACK WEST DURING THE EVENING. WILL MAINTAIN LOW PROBABILITIES ATTM...BUT FUTURE OTLKS MAY INTRODUCE SLGT RISK IF COVERAGE IS EXPECTED TO BE GREATER. ..RACY.. 05/27/2006  From swody2 at goshenarc.org Sun May 28 06:10:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 May 2006 02:10:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280608 SWODY2 SPC AC 280607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT SUN MAY 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY SWD THROUGH PARTS OF THE CENTRAL/SRN PLAINS... ...SYNOPSIS... STRONG RIDGE IS EXPECTED TO REMAIN CENTERED FROM THE CENTRAL GULF COAST STATES NWD TO HUDSON BAY. HEIGHTS IN THE WEST WILL BEGIN TO RISE AS STRONG SHORT WAVE TROUGH PROGGED TO MOVE NEWD INTO THE NRN HIGH PLAINS AND ALBERTA/SASKATCHEWAN BY LATE DAY 1 CONTINUES TO TRACK NEWD INTO CENTRAL CANADA. ...UPPER MS VALLEY TO SRN PLAINS... SURFACE FRONT ASSOCIATED WITH THE CANADIAN SHORT WAVE TROUGH IS EXPECTED TO EXTEND FROM WRN MN SSWWD THROUGH ERN NEB TO THE OK/NRN TX PANHANDLES AT 12Z MONDAY. THIS BOUNDARY WILL MOVE EWD THROUGH THE PERIOD AND SHOULD EXTEND FROM ERN MN TO ERN KS INTO WRN OK/NW TX BY LATE MONDAY AFTERNOON /TOWARD 30/00Z/. DRY LINE IS EXPECTED TO EXTEND SWD FROM NWRN OK WHERE IT INTERSECTS COLD FRONT AND THEN TO THE TX BIG BEND REGION. ALTHOUGH THE UPPER TROUGH WILL BE MOVING NEWD INTO CANADA...THE ENTRANCE REGION OF A STRONG SWLY MID LEVEL JET ACCOMPANYING THIS SYSTEM IS EXPECTED TO PROVIDE FAVORABLE ASCENT FOR UPWARD VERTICAL MOTION ACROSS UPPER MS VALLEY INTO IA. THUNDERSTORM CLUSTER...POTENTIALLY SEVERE...IS EXPECTED TO BE ONGOING AT THE START OF DAY 2 ACROSS PARTS OF THE ERN DAKOTAS INTO WRN MN. THIS ACTIVITY SHOULD DECREASE IN INTENSITY MONDAY MORNING AS IT SPREADS ENE ACROSS MN...GIVEN A WEAKENING TREND IN THE LLJ ACROSS THIS AREA. STRONG SURFACE HEATING /UNSEASONABLY WARM TEMPERATURES MONDAY AFTERNOON/ EXPECTED TO PERSIST INTO DAY 2 PERIOD ALONG/E OF FRONT COMBINED WITH VERY MOIST AIR MASS AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT VERY STRONG INSTABILITY. ALTHOUGH STRONGER MID LEVEL WINDS ARE EXPECTED TO REMAIN ATOP THE POST-FRONTAL AIR MASS...AT LEAST 25-30 KT OF MID LEVEL FLOW SHOULD BE LOCATED FROM THE UPPER MS VALLEY SWD INTO ERN KS/NRN OK AIDING IN STORM ORGANIZATION. LARGE SCALE ASCENT WITHIN MID LEVEL JET ENTRANCE COMBINED WITH LOW LEVEL CONVERGENCE ALONG THE FRONT WILL ALLOW THUNDERSTORMS TO DEVELOP BY EARLY-MID AFTERNOON ACROSS MN WITH ACTIVITY DEVELOPING SWD ALONG THE FRONT INTO IA. GIVEN VERY STRONG INSTABILITY AND MODERATE DEEP LAYER SHEAR ORIENTED PARALLEL TO SURFACE BOUNDARY... STORM MODE SHOULD BE LINEAR WITH POTENTIAL FOR EMBEDDED SUPERCELLS WITHIN THE LINE OF ACTIVITY. POTENTIAL EXISTS FOR VERY LARGE HAIL WITH THE STRONGEST STORMS GIVEN THE DEGREE OF INSTABILITY FORECAST. THE STORMS OVER MN/IA WILL MOVE EWD INTO WI/NRN IL MONDAY EVENING...BUT SEVERE THREAT SHOULD DIMINISH WITH EWD EXTENT GIVEN DECREASING INSTABILITY MONDAY NIGHT. FARTHER S...THE LACK OF STRONGER UPPER FORCING SUGGESTS SURFACE HEATING WILL BE THE PRIMARY IMPETUS IN WEAKENING THE CAP FOR THUNDERSTORM DEVELOPMENT JUST AFTER PEAK HEATING ALONG THE FRONT AND DRY LINE IN KS/WRN OK INTO W TX. DEEP LAYER SHEAR IS EXPECTED TO BE SUFFICIENT /AROUND 25 KT/ FOR ORGANIZED STORMS...WITH LARGE HAIL AND DAMAGING WINDS BEING THE PRIMARY THREATS. MODELS SUGGEST THE POTENTIAL FOR ONE OR TWO MCS/S TO DEVELOP MONDAY NIGHT...WITH ONE OVER KS AND/OR OK AND THE SECOND ACROSS IA/NRN MO INTO WRN IL. THESE MCS/S WILL BE MAINTAINED BY STRENGTHENING NOCTURNAL SSWLY LLJ EXTENDING INTO THESE REGIONS COMBINED WITH SUFFICIENT EFFECTIVE BULK SHEAR/INSTABILITY FOR A CONTINUED SEVERE POTENTIAL OVERNIGHT. ...WRN NEW ENGLAND/CENTRAL-ERN NY INTO NERN PA... MODELS TEND TO AGREE THAT AN MCS TOPPING THE RIDGE LATE DAY 1 ACROSS SERN ONTARIO/SRN QUEBEC SHOULD BE ENTERING THE U.S. IN UPSTATE NY/NRN VT TOWARD 12Z MONDAY. THIS CLUSTER OF STORMS SHOULD BE IN THE DECAYING PHASE MONDAY MORNING AS IT TRACKS SEWD ACROSS NEW ENGLAND. OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS MAY PROVIDE A FOCUS FOR AFTERNOON/EARLY EVENING THUNDERSTORMS ACROSS PARTS OF WRN NEW ENGLAND INTO ERN/CENTRAL NY AND NERN PA. AIR MASS ACROSS THESE REGIONS SHOULD BECOME MODERATELY UNSTABLE. THIS COMBINED WITH MODEST LAPSE RATES /AROUND 6.5 C/KM/ AND 30 KT OF NWLY MID LEVEL FLOW MAY ALLOW FOR A FEW STORMS TO PRODUCE MARGINALLY SEVERE HAIL AND/OR A STRONG WIND GUST. THUS...HAVE INTRODUCED A LOW SEVERE PROBABILITY /5%/. ..PETERS.. 05/28/2006  From swody2 at goshenarc.org Sun May 28 17:34:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 May 2006 13:34:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281733 SWODY2 SPC AC 281732 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CDT SUN MAY 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VLY SWD INTO THE CNTRL PLAINS... ...SYNOPSIS... UPPER TROUGH ACROSS THE WRN STATES IS EXPECTED TO LIFT NEWD...GLANCING OFF THE NWRN PERIPHERY OF STRONG SERN STATES RIDGE. AT THE SFC...FRONT WILL MOVE EWD ACROSS THE UPPER MS VLY AND SETTLE SWD THROUGH THE CNTRL PLAINS BY MON EVE. ...UPPER MS VALLEY TO CNTRL PLAINS... WARM ADVECTION DERIVED TSTM CLUSTERS /ISOLD SEVERE/ ARE EXPECTED TO BE MOVING NEWD THROUGH PARTS OF THE ERN DAKS AND WRN MN AT THE BEGINNING OF THE PERIOD. THESE STORMS SHOULD WEAKEN THROUGH THE MORNING AS THE LLJ BEGINS TO WEAKEN. AHEAD OF THE COLD FRONT...AIR MASS IS EXPECTED TO REMAIN POTENTIALLY VERY UNSTABLE AS SEASONABLY MOIST AND WARM BOUNDARY LAYER PERSISTS ACROSS THE CORN BELT INTO THE UPPER MS VLY. HEATING AND WEAK LARGE SCALE HEIGHT FALLS ALONG THE NWRN PERIPHERY OF THE UPPER RIDGE WILL PROBABLY WEAKEN CINH SUFFICIENTLY FOR TSTMS TO INITIATE ALONG THE PRIMARY FRONT AND CONVECTIVE BOUNDARIES MON AFTN ACROSS THE UPPER MS VLY. THOUGH UPPER SUPPORT IS QUITE WEAK FARTHER S...STRONGER HEATING MAY CONTRIBUTE TO WEAKENING CINH AS FAR SW AS KS. THUS...TSTMS MAY DEVELOP OR BACKBUILD SWWD ACROSS THE CORN BELT...THE MID/LWR MO RVR VLY AND INTO KS LATE IN THE AFTN/EVE. STRONGER FLOW/EFFECTIVE VERTICAL SHEAR IS EXPECTED TO REMAIN ON THE COLD SIDE OF THE FRONT...BUT MAGNITUDE OF LAPSE RATES SUGGESTS ORGANIZED STORMS WILL BE POSSIBLE. ACTIVITY SHOULD DEVELOP INTO LINES ACROSS THE UPPER MS VLY AND CORN BELT...BUT MORE DISCRETE SUPERCELL STRUCTURES MAY BE POSSIBLE FARTHER SW. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREATS...WITH HAIL SIZE POSSIBLE EXCEEDING 2 INCHES ACROSS PARTS OF KS...SERN NEB INTO IA WHERE MID-LEVEL LAPSE RATES WILL BE STEEPER. ONE OR MORE MCS/S MAY EVOLVE OVERNIGHT MON...PRIMARILY ACROSS CNTRL/ERN KS AND ACROSS THE UPPER MS VLY. EWD EXTENT OF THE SEVERE THREAT APPEARS TO BE LIMITED AS SEASONABLY WARM TEMPERATURES ALOFT PERSIST WITHIN THE UPPER RIDGE AXIS. HIGHER PROBABILITIES FOR NOCTURNAL SEVERE WEATHER WILL BE ALONG WRN/SWRN FLANKS OF TSTMS CLUSTERS...NAMELY ACROSS PARTS OF IA...KS...MO AND PSBLY NERN OKLA WHERE HAIL WILL BE THE PRIMARY THREATS. ...WRN NEW ENGLAND/CENTRAL-ERN NY INTO NERN PA... MODELS ARE IN AGREEMENT THAT AN MCS TOPPING THE RIDGE LATE SUNDAY ACROSS SERN ONTARIO/SRN QUEBEC SHOULD BE ENTERING UPSTATE NY/NRN VT TOWARD 12Z MON. THIS CLUSTER OF STORMS SHOULD BE IN THE DECAYING PHASE MON MORNING AS IT TRACKS SEWD ACROSS NEW ENGLAND. OUTFLOW ENHANCED BACKDOOR COLD FRONT MAY PROVIDE A FOCUS FOR AFTN/EARLY EVE TSTMS ACROSS PARTS OF WRN NEW ENGLAND INTO ERN/CENTRAL NY AND NERN PA. AIR MASS ACROSS THESE REGIONS SHOULD BECOME MODERATELY UNSTABLE. THIS COMBINED WITH MODEST LAPSE RATES /AROUND 6.5 C/KM/ AND 30 KT OF NWLY MID LEVEL FLOW MAY ALLOW FOR A FEW STORMS TO PRODUCE MARGINALLY SEVERE HAIL AND/OR A STRONG WIND GUST. ..RACY.. 05/28/2006  From swody2 at goshenarc.org Mon May 29 06:16:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 May 2006 02:16:59 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290615 SWODY2 SPC AC 290614 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0114 AM CDT MON MAY 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN CO/FAR NERN NM EWD ACROSS SRN KS/WRN-NRN OK TO WRN MO... ...SYNOPSIS... MODELS CONTINUE TO INDICATE RISING HEIGHTS ACROSS THE WRN STATES ON TUESDAY AS A SHORT WAVE TROUGH...CURRENTLY MOVING ESEWD OVER NRN CA...TRACKS FROM THE CENTRAL ROCKIES TO THE NORTH CENTRAL STATES DURING THE DAY 2 PERIOD. A STRONGER LEAD UPPER TROUGH AND ASSOCIATED SURFACE LOW ARE EXPECTED TO DEEPEN AS THEY TRACK NEWD ACROSS CENTRAL CANADA TOWARD HUDSON BAY. MEANWHILE...DOWNSTREAM RIDGE AXIS THAT HAS BEEN CENTERED OVER THE ERN U.S. IS PROGGED TO TRANSLATE EWD TO ALONG THE ERN SEABOARD BY 12Z WEDNESDAY. IN THE LOW LEVELS...SURFACE FRONT ASSOCIATED WITH CANADIAN STORM SYSTEM WILL MOVE EWD ACROSS ONTARIO AND NRN GREAT LAKES REGION. THE TRAILING PORTION OF THIS BOUNDARY ACROSS IA INTO SRN PLAINS WILL BE NEARLY PARALLEL TO FLOW ALOFT SUGGESTING POTENTIAL FOR LITTLE SWD MOVEMENT. ...CENTRAL HIGH PLAINS SEWD INTO KS/OK... AN MCS MAY BE ONGOING 12Z TUESDAY ACROSS PARTS OF WRN/CENTRAL KS ASSOCIATED WITH WAA REGIME ALONG NOSE OF 35-40 KT SLY LLJ. THIS ACTIVITY SHOULD TRACK EWD TUESDAY MORNING AND DIMINISH IN INTENSITY AS THE LLJ JET WEAKENS. ASSOCIATED OUTFLOW BOUNDARY WILL EITHER REINFORCE THE SURFACE FRONT ACROSS SRN KS INTO NWRN OK OR ACT AS A SECOND FOCI FOR AFTERNOON THUNDERSTORM INITIATION ACROSS KS. SURFACE HEATING IN THE WAKE OF THIS MORNING ACTIVITY COMBINED WITH A MOIST AIR MASS BENEATH STEEP LAPSE RATES ARE EXPECTED TO RESULT IN MODERATE INSTABILITY FROM ERN CO INTO SRN KS AND SWD THROUGH TX PANHANDLE/WRN OK ALONG DRY LINE INTO CENTRAL TX. THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ALONG THE SURFACE FRONT...OUTFLOW BOUNDARIES...DRY LINE AND ALSO WITHIN UPSLOPE FLOW REGIME ALONG THE CENTRAL HIGH PLAINS OF ERN CO NWD TO ERN WY. ALTHOUGH HEIGHT FALLS WILL GENERALLY BE NEGLIGIBLE ACROSS THIS REGION...MODERATE SWLY MID LEVEL FLOW ATOP ESELY LOW LEVEL WINDS WILL RESULT IN STRONG DEEP LAYER SHEAR FOR SUPERCELLS. GREATEST SEVERE THREAT IS EXPECTED FROM ERN CO SEWD INTO SRN KS... CENTRAL/WRN OK AND THE TX PANHANDLE WHERE INSTABILITY WILL BE THE STRONGEST. IN FACT...THE POTENTIAL EXISTS FOR VERY LARGE HAIL WITH THE STORMS THAT DEVELOP TUESDAY AFTERNOON FROM SWRN KS/WRN OK INTO THE NERN TX PANHANDLE. SLY LLJ WILL RE-INTENSIFY TUESDAY NIGHT SUPPORTING THE UPSCALE GROWTH OF THUNDERSTORMS ACROSS ERN CO AND/OR SRN KS/NRN OK WITH THIS ACTIVITY POTENTIALLY REMAINING SEVERE AS IT TRACKS ESEWD ACROSS THE SRN PLAINS TUESDAY NIGHT. ...MO NEWD TO CENTRAL GREAT LAKES REGION... SURFACE FRONT SHOULD REMAIN NEARLY STATIONARY ACROSS MUCH OF MO AS THE PORTION EXTENDING INTO THE GREAT LAKES REGION SHOULD MOVE SLOWLY E AND SE REACHING LOWER MI TO NRN IL INTO MO BY 12Z WEDNESDAY. THUNDERSTORMS MAY BE ONGOING ACROSS THE WRN GREAT LAKES REGION INTO IA/NRN MO AT 12Z TUESDAY. A MOIST AIR MASS LOCATED ALONG/S OF THE FRONT/AHEAD OF ONGOING ACTIVITY AND BENEATH 7-7.5 C/KM MID LEVEL LAPSE RATES IS EXPECTED TO BECOME MODERATELY UNSTABLE TUESDAY SUPPORTING ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT. STRONGER MID LEVEL FLOW IS EXPECTED TO BE OVER THE POST-FRONTAL AIR MASS WITH AT BEST MODEST FLOW ALONG THE SURFACE BOUNDARY. THUS... WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT STORM ORGANIZATION...WITH A FEW OF THE STRONGER STORMS POTENTIALLY SUPPORTING AN ISOLATED HAIL/STRONG WIND GUST THREAT GIVEN THE MODERATE INSTABILITY. SOME INCREASE IN SWLY LOW LEVEL FLOW INTO THE GREAT LAKES REGION TUESDAY NIGHT MAY SUSTAIN THUNDERSTORM ACTIVITY OVERNIGHT...BUT WEAKENING INSTABILITY SHOULD PRECLUDE A SEVERE THREAT. ...PARTS OF NRN/CENTRAL TX... DEEP LAYER SHEAR ALONG THE DRY LINE IS EXPECTED TO BE WEAK...BUT GIVEN THE POTENTIAL FOR MODERATE INSTABILITY...A FEW SEVERE STORMS WILL BE POSSIBLE WITH ACTIVITY WEAKENING TUESDAY NIGHT AS THE LOSS OF DAYTIME HEATING STABILIZES THE BOUNDARY LAYER. ..PETERS.. 05/29/2006  From swody2 at goshenarc.org Mon May 29 17:33:10 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 May 2006 13:33:10 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291731 SWODY2 SPC AC 291730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT MON MAY 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL/SRN HIGH PLAINS... ...SYNOPSIS... WRN U.S. UPPER TROUGH IS FORECAST TO DEAMPLIFY WITH TIME...AS UPPER LOW GETS SHUNTED NEWD ACROSS CANADA BY STRONG/PERSISTENT ERN U.S. RIDGE. BELT OF MODERATE SWLY/WSWLY FLOW AT MID-LEVELS SHOULD PERSIST ACROSS THE CENTRAL/NRN PLAINS AND INTO THE UPPER MS VALLEY AN SRN FRINGES OF FLATTENING TROUGH...BUT OVERALL FLOW FIELD SHOULD REMAIN RELATIVELY WEAK FOR THIS TIME OF YEAR. AT THE SURFACE...BAROCLINIC ZONE INITIALLY EXTENDING FROM THE UPPER GREAT LAKES REGION SWWD INTO THE SRN HIGH PLAINS SHOULD WEAKEN/BECOME MORE ILL-DEFINED WITH TIME. HOWEVER...THIS FEATURE SHOULD REMAIN A FOCUS FOR CONVECTIVE DEVELOPMENT THROUGH THE PERIOD. ...CENTRAL AND SRN HIGH PLAINS... SURFACE LOW IS FORECAST OVER NRN NM/THE OK AND TX PANHANDLE REGION...WITH LOW-LEVEL ELYS/SELYS RESULTING IN UPSLOPE FLOW ACROSS THE CENTRAL AND SRN HIGH PLAINS. MODELS SUGGEST THAT DAYTIME HEATING COMBINED WITH AMPLE BOUNDARY-LAYER MOISTURE SHOULD RESULT IN MODERATE DESTABILIZATION FROM ERN CO/WRN KS SWD ACROSS ERN NM/THE SOUTH PLAINS OF TX. CONVECTION MAY BE ONGOING EARLY IN THE PERIOD ACROSS PARTS OF THIS REGION...WITH A REDEVELOPMENT/INTENSIFICATION OF STORMS EXPECTED BY AFTERNOON AS AIRMASS DESTABILIZES -- BOTH IN UPSLOPE FLOW ACROSS THE HIGH PLAINS AND ALONG STATIONARY/WARM FRONT WHICH SHOULD EXTEND W-E FROM AFOREMENTIONED SURFACE LOW ACROSS NRN OK OR KS. WITH ZONE OF ENHANCED /30 TO 40 KT/ WLY/WSWLY FLOW AT MID-LEVELS ATOP LOW-LEVEL SELYS/ELYS...SHEAR SUPPORTIVE OF SUPERCELL STORMS SHOULD ALLOW DEVELOPING STORMS TO RAPIDLY INTENSIFY/BECOME SEVERE. ALONG WITH POTENTIAL FOR A COUPLE OF TORNADOES...VERY LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE ACROSS A FAIRLY SMALL AREA INCLUDING NERN NM...SERN CO...SWRN KS...NWRN OK...AND THE TX/OK PANHANDLES. STORMS SHOULD CONTINUE THROUGH THE EVENING/OVERNIGHT...AIDED BY INTENSIFYING LOW-LEVEL JET/WARM ADVECTION. STORMS MAY EVOLVE INTO AN MCS...AND MOVE SEWD/SSEWD ACROSS PARTS OF OK AND THE TX PANHANDLE INTO NWRN TX THROUGH THE END OF THE PERIOD...ACCOMPANIED BY AT LEAST A LOW-END SEVERE THREAT. ...UPPER GREAT LAKES REGION SWWD ACROSS THE MID MO VALLEY... MODERATE INSTABILITY BUT WEAK SHEAR IS FORECAST IN A SW-NE ZONE ALONG WEAKENING COLD FRONT. WIDESPREAD CONVECTION IS FORECAST ALONG/AHEAD OF THIS FRONT...BUT EXPECT OVERALL CONVECTIVE INTENSITY/ORGANIZATION TO REMAIN LIMITED BY WEAK SHEAR. NONETHELESS...DEGREE OF INSTABILITY SHOULD SUPPORT BRIEFLY SEVERE/PULSE-TYPE CONVECTION...WITH THE STRONGEST STORMS CAPABLE OF PRODUCING HAIL AND LOCALLY GUSTY WINDS. THREAT SHOULD DIMINISH AFTER SUNSET WITH THE ONSET OF DIURNAL COOLING/STABILIZATION. ...ERN WY INTO THE NEB PNHDL/WRN SD... THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE AFTERNOON -- IN UPSLOPE FLOW OVER ERN WY AND THE BLACK HILLS...AND ALONG WEAK/SECONDARY FRONT FORECAST TO BE LYING NE-SW ACROSS SD. THOUGH BOUNDARY LAYER MOISTURE -- AND THUS INSTABILITY -- SHOULD BE LIMITED /BELOW 500 J/KG MEAN-LAYER CAPE/...MID-LEVEL FLOW WILL CONTRIBUTE TO SHEAR SUFFICIENT FOR A FEW ORGANIZED STORMS. ALONG WITH A THREAT FOR HAIL WITH THESE STRONGER CELLS...LOCALLY GUSTY/DAMAGING WINDS MAY ALSO OCCUR GIVEN DEEP MIXED LAYER AND ASSOCIATED POTENTIAL FOR EVAPORATIVELY-DRIVEN DOWNDRAFTS. ..GOSS.. 05/29/2006  From swody2 at goshenarc.org Tue May 30 06:11:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 30 May 2006 02:11:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300610 SWODY2 SPC AC 300608 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT TUE MAY 30 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN HIGH PLAINS... ...SYNOPSIS... MODELS ARE IN GENERAL AGREEMENT WITH THE TIMING OF THE CURRENT WRN TROUGH WHICH SHOULD BE LOCATED OVER THE NRN HIGH PLAINS AT 12Z WEDNESDAY. THIS TROUGH SHOULD TRACK EWD TO THE UPPER MS VALLEY BY WEDNESDAY EVENING...AND THEN AMPLIFY SEWD INTO THE WRN GREAT LAKES/MID MS VALLEY IN RESPONSE TO HEIGHT RISES ACROSS MUCH OF WRN NORTH AMERICA. IN THE LOW LEVELS...A COLD FRONT EXTENDING FROM SRN ONTARIO AND SRN GREAT LAKES REGION SWWD TO OK AND TX PANHANDLE SHOULD MOVE SLOWLY SWD. THIS BOUNDARY...THOUGH WEAK...IS EXPECTED TO REMAIN A FOCUS FOR THUNDERSTORMS THROUGH THE DAY 2 FORECAST PERIOD. ...SRN HIGH PLAINS... COLD FRONT INITIALLY EXTENDING ACROSS OK INTO THE TX PANHANDLE AT 12Z WEDNESDAY IS EXPECTED TO MOVE SWD AND SHOULD REACH CENTRAL AND SW TX BY 12Z THURSDAY AS SURFACE HIGH PRESSURE BUILDS SWD ACROSS THE PLAINS. AT THE START OF DAY 2...ONE OR TWO MCS/S SHOULD BE ONGOING ACROSS MAINLY KS AND OK IN RESPONSE TO WAA ALONG THE NOSE OF A NOCTURNAL SLY LLJ EXTENDING FROM W TX INTO WRN KS. THIS ACTIVITY IS EXPECTED TO DIMINISH WEDNESDAY MORNING AS THE LLJ WEAKENS. STEEP MID LEVEL LAPSE RATES ARE PROGGED TO BE CONFINED TO CO/NM INTO W TX...WHERE COMBINED WITH SURFACE HEATING AND SURFACE DEWPOINTS IN THE UPPER 50S WILL RESULT IN MODERATE INSTABILITY FROM W TX/ERN NM INTO SERN CO. MOIST UPSLOPE FLOW INTO NM/CO IS EXPECTED TO AID THUNDERSTORM DEVELOPMENT WEDNESDAY AFTERNOON WITH ACTIVITY MOVING SEWD WITHIN WNWLY MID LEVEL FLOW. GIVEN THE WNWLY MID LEVEL FLOW ATOP ESELY LOW LEVEL WINDS...DEEP LAYER SHEAR WILL BE SUFFICIENT /30-40 KT/ FOR ORGANIZED STORMS. ACTIVITY WILL LIKELY BECOME SEVERE AS IT TRACKS SEWD INTO STRONGER INSTABILITY. CONTINUATION OF AFOREMENTIONED FLOW REGIME SHOULD SUPPORT THUNDERSTORMS... POTENTIALLY IN THE FORM OF CLUSTERS...SPREADING SEWD ACROSS SWRN KS AND INTO WRN OK/NW TX BY 12Z THURSDAY. THUNDERSTORMS SHOULD ALSO DEVELOP ALONG THE SWD MOVING COLD FRONT ACROSS OK AND PARTS OF NW TX...BUT THE COMBINATION OF WEAK MID LEVEL LAPSE RATES...MARGINAL INSTABILITY AND WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT THE SEVERE POTENTIAL WEDNESDAY AFTERNOON/ EVENING. ...PARTS OF ERN DAKOTAS INTO WRN MN... ONE OR TWO RESIDUAL SURFACE BOUNDARIES EXPECTED TO BE OVER THE DAKOTAS INTO SW MN/NRN IA WILL PROVIDE THE FOCUS FOR THUNDERSTORMS ON WEDNESDAY. STEEP MID LEVEL LAPSE RATES AND ASCENT SPREADING EWD ACROSS THIS REGION WITH THE UPPER TROUGH ARE EXPECTED TO AID IN THUNDERSTORM DEVELOPMENT WEDNESDAY AFTERNOON/EVENING. MODELS SUGGEST SURFACE DEWPOINTS IN THE LOWER 50S MAY ADVECT NWD INTO THIS AREA ON WEDNESDAY AIDING IN AT LEAST WEAK INSTABILITY FOR A FEW SEVERE STORMS GIVEN STRONG DEEP LAYER SHEAR. ...SRN GREAT LAKES REGION/OH VALLEY TO MID MS/LOWER MO VALLEYS... AIR MASS ALONG/S OF THE WEAK COLD FRONT IS EXPECTED TO REMAIN MOIST WITH SURFACE DEWPOINTS IN THE 60S. THIS COMBINED WITH SURFACE HEATING SHOULD RESULT IN MODERATE INSTABILITY. THUNDERSTORMS WILL LIKELY DEVELOP WITHIN THIS AIR MASS...BUT GENERALLY WEAK UPPER FORCING COMBINED WITH WEAK MID LEVEL LAPSE RATES SHOULD LIMIT THE NUMBER OF STORMS THAT CAN PRODUCE SUSTAINED UPDRAFTS. IN ADDITION...STRONGER MID LEVEL FLOW IS PROGGED TO REMAIN ON THE COLD SIDE OF THE FRONT RESULTING IN WEAK DEEP LAYER SHEAR...FURTHER INHIBITING THE POTENTIAL FOR STORM ORGANIZATION AND ATTENDANT SEVERE THREAT. ..PETERS.. 05/30/2006  From swody2 at goshenarc.org Tue May 30 17:33:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 30 May 2006 13:33:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301732 SWODY2 SPC AC 301731 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1231 PM CDT TUE MAY 30 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH PLAINS REGION... ...SYNOPSIS... ERN U.S. RIDGE ALOFT IS FORECAST TO WEAKEN THIS PERIOD...AS SHORT-WAVE TROUGH INITIALLY OVER THE NRN ROCKIES/NRN PLAINS SHIFTS SLOWLY EWD. MEANWHILE...FLOW ACROSS THE WRN HALF OF THE CONUS WILL AMPLIFY WITH TIME...AS RIDGE BUILDS ACROSS THE ROCKIES IN THE WAKE OF AFOREMENTIONED SHORT-WAVE TROUGH AND AHEAD OF LARGE UPPER LOW/TROUGH APPROACHING THE W COAST FROM THE ERN PACIFIC. AT THE SURFACE...COLD FRONT IS FORECAST TO MOVE EWD ACROSS THE GREAT LAKES REGION INTO NEW ENGLAND...WHILE SETTLING SWD ACROSS THE MIDWEST/OH VALLEY REGION. MEANWHILE...WEAKER/MORE SUBTLE AXIS OF SURFACE CONVERGENCE IS FORECAST TO MOVE SLOWLY SEWD ACROSS MN/SD/IA/NEB THROUGH THE PERIOD. ...CENTRAL AND SRN HIGH PLAINS... ELY/SELY LOW-LEVEL UPSLOPE FLOW INTO ERN PORTIONS OF CO/NM COMBINED WITH MARGINAL AFTERNOON INSTABILITY /500 TO 1000 J/KG MEAN-LAYER CAPE/ WILL RESULT IN CONVECTIVE DEVELOPMENT ALONG AND NEAR THE FRONT RANGE. WITH 20 TO 25 KT WLYS AT MID-LEVELS...DEGREE OF VEERING/SHEAR WILL LIKELY SUPPORT A THREAT FOR ORGANIZED/SUPERCELL STORMS ALONG WITH ASSOCIATED THREAT FOR HAIL/LOCALLY DAMAGING WINDS. STORMS SHOULD MOVE SEWD OFF THE HIGHER TERRAIN WITH TIME...AND LIKELY CONTINUE INTO THE OVERNIGHT HOURS AS LOW-LEVEL JET STRENGTHENS. THOUGH SEVERE THREAT SHOULD DIMINISH AFTER SUNSET...A LOW-END THREAT FOR SEVERE WEATHER MAY CONTINUE WELL INTO THE OVERNIGHT HOURS -- PARTICULARLY ACROSS ERN NM AND INTO ADJACENT PORTIONS OF TX AS LOW-LEVEL JET SHOULD BE STRONGEST ACROSS THIS AREA. ...WRN NEW ENGLAND/THE GREAT LAKES WSWWD ACROSS THE MIDWEST... WEAK DEEP-LAYER WIND FIELD BUT MODERATE INSTABILITY IS FORECAST AHEAD OF WEAK COLD FRONT MOVING EWD/SEWD ACROSS THE GREAT LAKES/OH VALLEY REGION. DESPITE THE OVERALL LACK OF SHEAR...DEGREE OF INSTABILITY WILL SUPPORT WIDESPREAD CONVECTION NEAR AND AHEAD OF FRONT. THOUGH STORMS SHOULD REMAIN GENERALLY PULSE IN NATURE...A FEW STRONGER/BRIEFLY INTENSE STORMS WILL LIKELY PRODUCE BRIEF GUSTY/DAMAGING WINDS AND/OR HAIL. THREAT SHOULD DIMINISH RAPIDLY AFTER SUNSET. ...NRN PLAINS/UPPER MS VALLEY REGION... THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE AFTERNOON INVOF WEAK SURFACE TROUGH/CONVERGENCE AXIS...AHEAD OF SHORT-WAVE TROUGH MOVING ACROSS THE NRN PLAINS. THOUGH INSTABILITY IS FORECAST TO BE WEAK /GENERALLY LESS THAN 500 J/KG MEAN-LAYER CAPE/...BAND OF ENHANCED /20 TO 30 KT/ FLOW AT MID-LEVELS AHEAD OF THE UPPER FEATURE MAY SUPPORT A FEW STRONGER/ORGANIZED CELLS CAPABLE OF PRODUCING MARGINAL HAIL/LOCALLY GUSTY WINDS. ANY SEVERE THREAT LINGERING INTO THE EVENING SHOULD DIMINISH AS AIRMASS STABILIZES. ..GOSS.. 05/30/2006