From swody2 at goshenarc.org Sat Jul 1 05:47:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 01 Jul 2006 01:47:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 010547 SWODY2 SPC AC 010546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT SAT JUL 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND AND THE MIDDLE ATLANTIC STATES WWD INTO PORTIONS OF THE UPPER MIDWEST AND CNTRL PLAINS... ...SYNOPSIS... MODERATELY STRONG /45-55 KT/ CYCLONIC...MID-LEVEL FLOW REGIME WILL BE MAINTAINED THROUGH THE PERIOD FROM THE UPPER MS VALLEY EWD THROUGH THE GREAT LAKES AND INTO THE NERN STATES. LOW-AMPLITUDE SHORT WAVE TROUGH /INITIALLY OVER SRN QUEBEC INTO THE UPPER HUDSON VALLEY/ WILL MOVE ACROSS NRN/CNTRL NEW ENGLAND SUNDAY...WITH SEVERAL WEAKER...UPSTREAM IMPULSES TRANSLATING FROM THE NRN PLAINS/UPPER MS VALLEY EWD ACROSS THE GREAT LAKES. IN THE LOW-LEVELS...PRIMARY SURFACE LOW ATTENDANT TO THE SRN QUEBEC IMPULSE WILL REMAIN N OF INTERNATIONAL BORDER OVER CNTRL OR SRN QUEBEC WHILE TRAILING FRONTAL BOUNDARY PUSHES EWD THROUGH THE HUDSON VALLEY AND NEW ENGLAND. WRN EXTENSION OF THIS FRONT WILL REMAIN QUASI-STATIONARY ACROSS THE NRN OH VALLEY/SRN GREAT LAKES WWD TO SECONDARY LOW PRESSURE OVER THE CNTRL HIGH PLAINS. MEANWHILE... ANOTHER WEAK COLD FRONT WILL PUSH SEWD THROUGH THE NRN PLAINS AND UPPER MS VALLEY. ...NEW ENGLAND/MIDDLE ATLANTIC STATES... RELATIVELY STEEP LOW/MID-LEVEL LAPSE RATES COUPLED WITH BOUNDARY-LAYER DEWPOINTS IN THE 60S ARE EXPECTED TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS SUNDAY WITH MLCAPES RANGING FROM AROUND 1000 J/KG OVER PORTIONS OF NRN/CNTRL NEW ENGLAND TO 1500-2500 J/KG FROM SRN ENGLAND SWWD THROUGH THE LOWER HUDSON AND DE RIVER VALLEYS INTO SRN PA. CLUSTERS OF TSTMS SHOULD BE ONGOING SUNDAY MORNING OVER PORTIONS OF UPSTATE NY IN ADVANCE OF MIGRATORY SHORT WAVE TROUGH. WSWLY LLJ WILL MAINTAIN AN INFLUX OF THIS MODERATELY UNSTABLE AIR MASS INTO SRN AND SWRN FLANK OF STORM COMPLEX...PROMOTING INTENSIFICATION OF THIS ACTIVITY BY AFTERNOON AS IT MOVES THROUGH NRN AND CNTRL NEW ENGLAND. ADDITIONAL STORM DEVELOPMENT APPEARS LIKELY ALONG TRAILING OUTFLOW OR SYNOPTIC FRONT ACROSS SRN NEW ENGLAND WWD INTO THE LOWER HUDSON VALLEY AND PARTS OF SRN NY/PA/NJ. WHILE PRIMARY CONVECTIVE MODE WILL LIKELY REMAIN LINEAR...ESPECIALLY ACROSS NRN PORTIONS OF THE DISCUSSION AREA...FORECAST HODOGRAPHS OVER SRN NEW ENGLAND INTO THE MID/LOWER HUDSON VALLEY INDICATE A DISTINCT THREAT OF SUPERCELLS GIVEN MORE DISCRETE STORM INITIATION. DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY SEVERE WEATHER THREATS...HOWEVER TORNADOES WILL BE POSSIBLE WITH ANY SUPERCELLS THAT CAN BECOME ESTABLISHED. ...SRN GREAT LAKES/OH VALLEY WWD INTO PORTIONS OF THE UPPER MIDWEST AND CNTRL PLAINS... A MODERATELY UNSTABLE AIR MASS /MLCAPES OF 1500-2500 J/KG/ IS FORECAST TO DEVELOP ALONG LENGTH OF QUASI-STATIONARY BOUNDARY OWING TO STEEP LAPSE RATES AND DEWPOINTS IN THE 60S. PERSISTENT LOW-LEVEL CONVERGENCE COUPLED WITH THE INFLUENCE OF WEAK IMPULSES EMBEDDED IN PROGRESSIVE MID-LEVEL PATTERN WILL AID IN THE DEVELOPMENT OF SCATTERED TSTMS DURING THE AFTERNOON AND EVENING HOURS FROM OH/IND AND SRN LOWER MI WWD INTO IA/NEB. ADDITIONAL STORMS WILL ALSO BE POSSIBLE ALSO WEAK COLD FRONT PUSHING SEWD THROUGH THE ERN DAKOTAS AND MN. WHILE THE STRONGEST MID AND HIGH-LEVEL WIND FIELDS WILL RESIDE N OF PRIMARY INSTABILITY AXIS...SUFFICIENT DEEP-LAYER SHEAR /30-40 KTS THROUGH THE LOWEST 6 KM/ WILL EXIST ALONG FRONTAL ZONE...SUPPORTIVE OF ORGANIZED SEVERE STORMS INCLUDING A FEW SUPERCELLS AND BOWING STRUCTURES. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY SEVERE WEATHER HAZARDS. ...ORE... FORCING FOR ASCENT ASSOCIATED WITH APPROACHING SHORT WAVE TROUGH WILL EFFECTIVELY STEEP LAPSE RATES...CONTRIBUTING TO WEAK TO MODERATE INSTABILITY WITH MLCAPES OF 500-1000 J/KG. DAYTIME HEATING IN CONJUNCTION WITH THIS FORCING WILL SUPPORT SCATTERED TSTM DEVELOPMENT BY LATE AFTERNOON INTO THE EVENING...MAINLY E OF THE CASCADES. ISOLATED LARGE HAIL AND/OR LOCALLY GUSTY WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS...THOUGH THE RELATIVELY WEAK VERTICAL SHEAR SHOULD LIMIT A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 07/01/2006  From swody2 at goshenarc.org Sat Jul 1 17:22:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 01 Jul 2006 13:22:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 011721 SWODY2 SPC AC 011720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 PM CDT SAT JUL 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS...CNTRL PLAINS...OH VALLEY...NRN APPALACHIAN MTNS...MID-ATLANTIC AND NEW ENGLAND... ...OH VALLEY... WEST TO NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH SUNDAY ACROSS THE NRN US WITH A BROAD UPPER-LEVEL TROUGH OVER SERN CANADA AND THE GREAT LAKES REGION. MODEL FORECASTS BRING SEVERAL MINOR SHORTWAVE TROUGHS ACROSS THE REGION SUNDAY WHICH SHOULD PROVIDE SUPPORT FOR SCATTERED TO NUMEROUS THUNDERSTORMS ALONG A QUASI-STATIONARY FRONTAL BOUNDARY SITUATED FROM IA EXTENDING EWD ACROSS NRN IL...NRN IND AND OH. BOTH THE WRF AND GFS DEVELOP A POCKET OF MODERATE TO STRONG INSTABILITY ACROSS THE NRN OH VALLEY ALONG AND JUST SOUTH OF THE FRONT. IN ADDITION...FORECAST SOUNDINGS SHOW MODERATE VERTICAL SHEAR SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS AND/OR BOW ECHOES. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER STORMS IN THE LATE AFTERNOON AND EARLY EVENING. AS STORM COVERAGE EXPANDS DURING THE EVENING...THE WIND DAMAGE POTENTIAL MAY BECOME ENHANCED WITH ANY MCS THAT ORGANIZES AND TRACKS SEWD ACROSS THE REGION. ...NERN US... A BROAD SERN CANADA UPPER-LEVEL TROUGH WILL REMAIN IN PLACE THROUGH SUNDAY AS A 70 KT MID-LEVEL JET DRIFTS EWD ACROSS SRN QUEBEC. LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH AND LIFT FROM THE RIGHT REAR QUADRANT OF THE MID-LEVEL JET SHOULD SUPPORT STRONG THUNDERSTORM DEVELOPMENT ACROSS THE REGION SUNDAY AFTERNOON. THUNDERSTORMS WILL LIKELY INITIATE IN THE NRN APPALACHIAN MTNS AND SPREAD EWD INTO THE MID-ATLANTIC AND SRN NEW ENGLAND BY LATE AFTERNOON. MODEL FORECASTS SHOW AN AXIS OF MODERATE INSTABILITY EXTENDING NWD THROUGH NJ INTO THE NEW YORK CITY AREA. THIS COMBINED WITH 30 TO 40 KT OF MID-LEVEL FLOW SHOULD PROVIDE VERTICAL SHEAR SUFFICIENT FOR SUPERCELLS AND/OR BOW ECHOES. UNIDIRECTIONAL WIND PROFILES AND STEEP LOW-LEVEL LAPSE RATES WILL FAVOR WIND DAMAGE AS THE MOST WIDESPREAD THREAT ALTHOUGH HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. ...HIGH PLAINS/CNTRL PLAINS... WEST TO NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS THE REGION TONIGHT INTO SUNDAY. AT THE SFC...UPSLOPE FLOW WILL CONTINUE ACROSS NEB...NERN CO AND SERN WY. THIS WILL REINFORCE 50S TO LOWER 60S F DEWPOINTS IN THE HIGH PLAINS. THUNDERSTORMS WILL LIKELY INITIATE IN THE HIGHER TERRAIN OF SERN WY AND NERN CO WITH ADDITIONAL DEVELOPMENT POSSIBLE IN THE CNTRL PLAINS ALONG ANY PREEXISTING BOUNDARIES AS SFC TEMPS WARM DURING THE DAY. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE REGION SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE MAINLY FROM STRONG VEERING IN THE LOW TO MID-LEVELS. THIS COMBINED WITH MODERATE INSTABILITY WILL BE SUFFICIENT FOR SUPERCELLS. VERY STEEP MID-LEVEL LAPSE RATES WILL FAVOR LARGE HAIL AS THE GREATEST THREAT...ALTHOUGH ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY ALONG THE LEADING EDGE OF ANY MCS THAT ORGANIZES AND MOVES EWD ACROSS THE REGION IN THE EVENING. ..BROYLES.. 07/01/2006  From swody2 at goshenarc.org Sun Jul 2 05:19:50 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 02 Jul 2006 01:19:50 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 020519 SWODY2 SPC AC 020518 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1218 AM CDT SUN JUL 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OF THE UPPER MIDWEST/CNTRL GREAT LAKES INTO MID MO VALLEY... ...SYNOPSIS... MID AND UPPER-LEVEL LOW WILL SLOWLY SHIFT EWD ACROSS NRN ONTARIO DURING THE DAY TWO PERIOD WITH A SERIES OF IMPULSES ROTATING THROUGH THE BASE OF THIS FEATURE ACROSS THE UPPER MS VALLEY AND GREAT LAKES. FATHER W...AMPLIFIED RIDGE WILL PERSIST OVER WRN CANADA AND THE INTERMOUNTAIN W...DOWNSTREAM FROM UPPER LOW OVER THE NERN PACIFIC. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WILL CONCURRENTLY SHIFT EWD ACROSS NRN ONTARIO WITH ATTENDANT UPPER SYSTEM. MEANWHILE... TRAILING COLD FRONT WILL PUSH SEWD THROUGH THE UPPER MIDWEST INTO CNTRL GREAT LAKES...WITH SWWD EXTENSION OF BOUNDARY THROUGH THE MID/LOWER MO VALLEY INTO CNTRL HIGH PLAINS. ...UPPER MIDWEST/CNTRL GREAT LAKES INTO THE MID MO VALLEY... COLD FRONT PUSHING SEWD THROUGH THE REGION WILL BE THE PRIMARY FEATURE FOCUSING STRONG TO SEVERE TSTM DEVELOPMENT MONDAY AFTERNOON AND NIGHT. AHEAD OF THE BOUNDARY...DEWPOINTS ARE EXPECTED TO REMAIN IN THE 60S. DAYTIME HEATING AND MODERATELY STEEP LAPSE RATES IN CONJUNCTION WITH THIS MOISTURE WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF 1000-2000 J/KG. TSTMS ARE FORECAST TO BECOME INCREASINGLY LIKELY ALONG FRONT OVER PORTIONS OF NRN/CNTRL WI INTO CNTRL/SRN MN BY AFTERNOON AS HEIGHT FALLS ASSOCIATED WITH SHORT WAVE TROUGH ROTATING SEWD THROUGH THE WRN GREAT LAKES BEGINS TO OVERSPREAD WARM SECTOR. WITH TIME...STORMS SHOULD MOVE/DEVELOP INTO THE CNTRL GREAT LAKES...AND SWWD INTO THE MID MO VALLEY. LARGELY UNIDIRECTIONAL WIND FIELDS WILL LIKELY SUPPORT LINE SEGMENTS OR STORM CLUSTERS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. UPSCALE GROWTH INTO LARGER CLUSTERS OR AN MCS OR TWO IS ANTICIPATED MONDAY NIGHT WITH A MARGINAL WIND/HAIL THREAT SPREADING INTO THE NRN OH VALLEY WWD TO THE LOWER MO VALLEY. ...HUDSON VALLEY SWD INTO ERN NC... BOTH THE NAM AND GFS INDICATE THE PASSAGE OF A WEAK FRONT OR TROUGH THROUGH THE REGION MONDAY WHICH MAY FOCUS ISOLATED STRONG TO POTENTIALLY SEVERE STORMS. THE STRONGER WIND FIELDS WILL REMAIN TO THE N ACROSS THE HUDSON VALLEY...WHILE AIR MASS IS FORECAST TO BECOME MORE UNSTABLE FARTHER S FROM THE TIDEWATER INTO NC COASTAL PLAIN. ANY STORMS THAT DEVELOP SHOULD BE DIURNAL IN NATURE...CAPABLE OF MARGINALLY SEVERE WIND AND/OR HAIL AND TEND TO WEAKEN BY LATE EVENING. ...NRN ROCKIES INTO NRN/CNTRL HIGH PLAINS... ISOLATED STRONG TO SEVERE STORMS CAPABLE OF HIGH WINDS AND SOME HAIL WILL BE POSSIBLE MONDAY AFTERNOON AND NIGHT WITHIN STEEP LAPSE RATE ENVIRONMENT FROM SWRN MT INTO ERN WY...ERN CO AND WRN KS. A WEAK SHORT WAVE TROUGH UNDER-CUTTING WRN CANADA RIDGE WILL LIKELY BE THE FOCUS FOR AFTERNOON STORMS OVER SWRN INTO S-CNTRL MT. FARTHER S...EITHER FORCING ALONG SWRN EXTENSION OF SYNOPTIC FRONT OR OROGRAPHIC UPSLOPE FLOW APPEAR TO BE THE PRIMARY FORCING MECHANISMS FROM ERN WY INTO ERN CO/WRN KS. RELATIVELY DRY BOUNDARY-LAYER CONDITIONS SHOULD TEND TO LIMIT THE DEGREE OF INSTABILITY AND OVERALL SEVERE THREAT. ..MEAD.. 07/02/2006  From swody2 at goshenarc.org Mon Jul 3 05:15:02 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 03 Jul 2006 01:15:02 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 030514 SWODY2 SPC AC 030513 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1213 AM CDT MON JUL 03 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL/SRN NEW ENGLAND AND MIDDLE ATLANTIC COAST WWD INTO THE OH VALLEY... ...SYNOPSIS... OMEGA BLOCK FROM THE ERN PACIFIC TO ERN CANADA AND THE NERN U.S. WILL PERSIST THROUGH THE DAY TWO PERIOD WITH THE MAIN REGION OF HEIGHT FALLS SPREADING THROUGH THE GREAT LAKES AND NRN OH VALLEY INTO NEW ENGLAND AND THE MIDDLE ATLANTIC STATES. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WILL REMAIN OVER QUEBEC WITH TRAILING COLD FRONT PUSHING EWD THROUGH NEW ENGLAND AND MORE SEWD THROUGH THE SRN GREAT LAKES AND OH VALLEY. ...CNTRL/SRN NEW ENGLAND AND MIDDLE ATLANTIC COAST WWD INTO THE OH VALLEY... MODEST BOUNDARY-LAYER MOISTURE /CHARACTERIZED BY 60S DEWPOINTS/ WILL LARGELY CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS /MLCAPES OF 1000-1500 J/KG/ AS MID-LEVEL LAPSE RATES ARE FORECAST TO REMAIN RATHER WEAK. TSTMS MAY BE ONGOING AT THE ONSET OF THE PERIOD TUESDAY MORNING ALONG OR AHEAD OF COLD FRONT OVER THE ERN GREAT LAKES WWD ACROSS THE OH VALLEY. SOME OF THIS ACTIVITY MAY PERSIST THROUGH THE MORNING...EVENTUALLY INTENSIFYING AS INFLOW AIR MASS DESTABILIZES. ADDITIONAL STORM DEVELOPMENT IS ALSO LIKELY BY AFTERNOON ALONG THE FRONT FROM THE HUDSON VALLEY OR CNTRL NEW ENGLAND WWD ACROSS THE NRN OH VALLEY. VERTICAL WIND PROFILES ARE FORECAST TO REMAIN LARGELY UNIDIRECTIONAL THROUGH THE DURATION OF THE EVENT WITH THE STRONGEST DEEP-LAYER SPEED SHEAR /40-50 KTS IN THE LOWEST 6 KM AGL/ ACROSS NRN PORTION OF SLIGHT RISK AREA. LINE SEGMENTS WITH EMBEDDED BOWING STRUCTURES APPEAR MOST LIKELY WITH THE PRIMARY SEVERE WEATHER HAZARD BEING DAMAGING WINDS. LARGE HAIL WILL ALSO BE POSSIBLE WITH THE MOST INTENSE UPDRAFTS. THE SEVERE THREAT SHOULD END OVER NEW ENGLAND BY EARLY EVENING AS STORMS MOVE OFFSHORE. FARTHER SW...TSTM ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT FROM THE DELMARVA WWD INTO THE SRN OH VALLEY...THOUGH ANY ORGANIZED SEVERE THREAT IS EXPECTED TO DIMINISH BY MID TO LATE EVENING. ...ERN WY INTO WRN PARTS OF SD/NEB... SHORT WAVE TROUGH CURRENTLY LIFTING NEWD INTO ERN ORE/WRN ID IS FORECAST TO MOVE THROUGH MEAN RIDGE DURING THE DAY ONE PERIOD AND THEN SEWD THROUGH THE NRN AND CNTRL HIGH PLAINS TUESDAY INTO TUESDAY EVENING. THIS FEATURE IS LIKELY TO SUPPORT TSTM DEVELOPMENT BY AFTERNOON WITHIN UPSLOPE REGION OVER ERN WY INTO WRN PARTS OF SD/NEB. FORECAST SOUNDINGS INDICATE THAT AIR MASS WILL NOT BE PARTICULARLY UNSTABLE /MLCAPES LESS THAN 1000 J/KG/ OWING TO MARGINAL LOW-LEVEL MOISTURE AND LAPSE RATES. STRONG DIRECTIONAL SHEAR WILL BE SUPPORTIVE OF A FEW ORGANIZED STORMS CAPABLE OF ISOLATED DAMAGING WINDS AND HAIL. THE QUESTIONABLE INSTABILITY PRECLUDES ISSUANCE OF A CATEGORICAL RISK ATTM. ...ERN WA/NERN ORE/ID PNHDL... A STEEP LAPSE RATE ENVIRONMENT IS FORECAST TO DEVELOP ACROSS THE REGION TUESDAY AFTERNOON INTO EVENING WITH MLCAPES INCREASING TO 500-1000 J/KG. FORCING FOR ASCENT ASSOCIATED WITH AN APPROACHING SHORT WAVE TROUGH IS EXPECTED TO OVERSPREAD THE REGION NEAR THE TIME OF PEAK HEATING...LIKELY CONTRIBUTING TO AN INCREASE IN STORM COVERAGE AND INTENSITY. WHILE VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG...THE STEEP LAPSE RATES AND DEEPLY-MIXED BOUNDARY LAYER CONDITIONS INDICATE THE POTENTIAL FOR LOCALLY DAMAGING WINDS AND SOME SEVERE HAIL. ..MEAD.. 07/03/2006  From swody2 at goshenarc.org Mon Jul 3 16:58:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 03 Jul 2006 12:58:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 031656 SWODY2 SPC AC 031655 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CDT MON JUL 03 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND AND THE MID ATLANTIC REGION WWD INTO THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN WY/SWRN SD/WRN NEB... ...SYNOPSIS... HIGH AMPLITUDE FLOW PATTERN IS FORECAST TO PROGRESS SLOWLY EWD ON TUESDAY AS UPPER LOW OVER WRN ONTARIO MOVES TO THE ERN ONTARIO/WRN QUEBEC BORDER...UPSTREAM RIDGE MOVES OVER THE NRN HIGH PLAINS...AND A TROUGH REMAINS OVER THE ERN PACIFIC. AT THE SURFACE A BROAD AREA OF LOW PRESSURE IS FORECAST TO MOVE ACROSS ERN CANADA AND NEW ENGLAND IN ADVANCE OF THE UPPER LOW...WITH A SURFACE COLD FRONT EXPECTED TO MOVE SEWD ACROSS NEW ENGLAND...THE LOWER GREAT LAKES AND MIDDLE MS VALLEY. IN THE WEST...A SLOW MOVING COLD FRONT WILL MOVE INTO THE ERN PARTS OF WA AND OREGON. ...NERN STATES ACROSS THE OH VALLEY... MODELS INDICATE SEVERAL AREAS OF CONVECTION WILL BE OCCURRING DURING THE MORNING ALONG/AHEAD OF THE COLD FRONT FROM PARTS OF NY/PA WSWWD ACROSS THE MID MS VALLEY. CLOUD COVER SPREADING DOWNSTREAM FROM THIS ACTIVITY COUPLED WITH MODEST LAPSE RATES IS LIKELY TO INHIBIT STRONG DESTABILIZATION DURING THE DAY AHEAD OF THE FRONT...BUT DEW POINTS OF 65-70F AND LOCAL AREAS OF ENHANCED DIURNAL HEATING WILL CONTRIBUTE TO MAXIMUM MLCAPE VALUES OF 1000-1500 J/KG DURING THE AFTERNOON. THIS SUGGESTS INTENSIFICATION OF THUNDERSTORMS WILL OCCUR AS DYNAMIC FORCING FOR LARGE SCALE ASCENT IS ENHANCED BY DIVERGENCE ALOFT ASSOCIATED WITH RIGHT ENTRANCE REGION WITHIN UPPER LEVEL JET STREAK MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND DURING THE AFTERNOON AND EVENING. VERTICAL SHEAR PROFILES ARE FORECAST TO BE PRIMARILY UNIDIRECTIONAL...WITH STRONGEST DEEP LAYER SHEAR OF 35-45 KT IN THE LOWEST 6 KM EXPECTED OVER NRN PARTS OF THE SLIGHT RISK AREA FROM THE LOWER GREAT LAKES INTO NRN NEW ENGLAND. THIS WILL SUPPORT DEVELOPMENT OF MULTIPLE EMBEDDED LINE SEGMENTS WITH OCCASIONAL BOW ECHOES AND ATTENDANT THREAT FOR DAMAGING WIND GUSTS...ALONG WITH HAIL FROM STRONGER CELLS. ORGANIZED SEVERE POTENTIAL IS EXPECTED TO GRADUALLY DIMINISH WITH SWD EXTENT ACROSS THE OH VALLEY AND MIDDLE ATLANTIC REGION WHERE WINDS ALOFT/VERTICAL SHEAR ARE EXPECTED TO DECREASE. ...ERN WY INTO WRN NEB... WEAK UPSLOPE LOW LEVEL WINDS ARE FORECAST TO DEVELOP OVER PARTS OF THE HIGH PLAINS TOMORROW AS SURFACE HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. THIS WILL RESULT IN SURFACE DEWPOINTS IN THE 50S SPREADING INTO THIS REGION...AND ALTHOUGH MID LEVEL LAPSE RATES ARE EXPECTED TO BE MODEST AS HEIGHTS RISE OVER THE ROCKIES...ENVIRONMENT WILL BECOME UNSTABLE WITH MLCAPE OF AROUND 1000 J/KG DURING THE AFTERNOON. THUNDERSTORMS SHOULD DEVELOP DURING THE AFTERNOON OVER THE HIGHER TERRAIN OF WY AND SWRN SD AND MOVE SEWD INTO THE HIGH PLAINS ALONG THE SRN EDGE OF 20-25 KT NWLY MID LEVEL FLOW. STRONG DIRECTIONAL SHEAR WITH HEIGHT SHOULD BE SUFFICIENT TO ENHANCE STORM ORGANIZATION AND SUPPORT DEVELOPMENT OF A FEW SUPERCELLS WITH LARGE HAIL AND STRONG WIND GUSTS DURING THE LATE AFTERNOON AND EVENING. ...NRN INTERMOUNTAIN REGION... STEEP LAPSE RATES ARE EXPECTED TO PERSIST ACROSS THE AREA AS PRIMARY UPPER TROUGH REMAINS OVER THE ERN PACIFIC. PLUME OF MID LEVEL MOISTURE IS EXPECTED TO BE EMBEDDED WITHIN SSWLY FLOW ALOFT...SUGGESTING POTENTIAL FOR A FEW HIGHER-BASED THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON AND EVENING. STEEP LAPSE RATES AND DEEP WELL-MIXED LAYER SUGGESTS THREAT FOR ISOLATED MICROBURSTS AND POSSIBLE HAIL...BUT RELATIVELY WEAK DEEP LAYER SHEAR SHOULD LIMIT OVERALL SEVERE THREAT. ..WEISS.. 07/03/2006  From swody2 at goshenarc.org Tue Jul 4 05:34:30 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 04 Jul 2006 01:34:30 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040533 SWODY2 SPC AC 040532 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 AM CDT TUE JUL 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM FAR SRN NEW ENGLAND/DE RIVER VALLEY SWD THROUGH THE TIDEWATER AND CNTRL APPALACHIANS... ...SYNOPSIS... AMPLIFICATION OF ERN CONUS TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS EMBEDDED SHORT WAVE TROUGH INITIALLY OVER THE GREAT LAKES DIGS SEWD INTO THE CNTRL APPALACHIANS. IN THE W...SHORT WAVE TROUGH OVER NV/UT WEDNESDAY MORNING WILL LIFT NEWD INTO THE NRN ROCKIES WHILE IMPULSE ROTATING THROUGH BASE OF ERN PACIFIC TROUGH EJECTS NEWD INTO THE PACIFIC NW. IN THE LOW-LEVELS...COLD FRONT ASSOCIATED WITH THE ERN U.S. TROUGH WILL PUSH EWD THROUGH NEW ENGLAND AND MORE SEWD THROUGH THE MIDDLE ATLANTIC STATES...DELMARVA...CNTRL APPALACHIANS AND TN VALLEY. THIS FRONT WILL BE THE PRIMARY FOCUS FOR STRONG TO SEVERE STORMS THROUGH THE FORECAST PERIOD. ...FAR SRN NEW ENGLAND/DE RIVER VALLEY SWD THROUGH THE TIDEWATER AND CNTRL APPALACHIANS... CURRENT SURFACE OBSERVATIONS AND MODEL GUIDANCE INDICATE THAT A RELATIVELY MOIST LOW-LEVEL AIR MASS /DEWPOINTS IN THE 60S TO LOWER 70S/ WILL EXIST S OF COLD FRONT. THIS MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO AFTERNOON MLCAPES FROM AROUND 1000 J/KG OVER THE NRN PART OF THE SLIGHT RISK AREA TO 2000-2500 J/KG OVER THE SERN VA/NC COASTAL PLAIN. TSTMS WILL LIKELY PERSIST THROUGH MUCH OF THE PERIOD ALONG AND AHEAD OF THE FRONT OWING TO A WEAKLY CAPPED ENVIRONMENT. THE GREATEST SEVERE STORM THREAT IS EXPECTED DURING THE AFTERNOON INTO EVENING HOURS FROM THE DELMARVA/TIDEWATER REGION INTO THE VA/NC PIEDMONT AS SURFACE FRONT ENCOUNTERS STRONGEST INSTABILITY. LARGELY UNDIRECTIONAL WIND FIELDS AND FORCED ASCENT ALONG THE FRONT INDICATE THE LIKELIHOOD OF LINE SEGMENTS CAPABLE OF DAMAGING WINDS AND SOME LARGE HAIL. ...NRN ROCKIES... FORCING FOR ASCENT AHEAD OF SHORT WAVE TROUGHS LIFTING NEWD FROM THE GREAT BASIN AND ALONG THE PACIFIC NW COAST ARE EXPECTED TO CONTRIBUTE TO AN INCREASE IN TSTM COVERAGE THROUGH THE AFTERNOON AND EVENING FROM ERN PORTIONS OF WA/ORE THROUGH ID INTO WRN MT/WY. DEWPOINTS WILL REMAIN LARGELY IN THE MID 40S TO MID 50S...THOUGH THE PRESENCE OF STEEP LAPSE RATES WILL SUPPORT MLCAPES OF AROUND 1000 J/KG. THE STRONGEST MID AND HIGH-LEVEL WIND FIELDS AND RESULTING VERTICAL SHEAR ARE FORECAST TO REMAIN W OF MAIN INSTABILITY AXIS. HOWEVER...THE STEEP LAPSE RATES AND 25-30 KTS OF SHEAR THROUGH THE LOWEST 6 KM WILL SUPPORT A FEW ORGANIZED STORMS CAPABLE OF SEVERE HAIL AND LOCALLY DAMAGING WINDS. ..MEAD.. 07/04/2006  From swody2 at goshenarc.org Mon Jul 10 06:03:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 10 Jul 2006 02:03:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100602 SWODY2 SPC AC 100601 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT MON JUL 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SERN CO INTO THE TX PANHANDLE AND EWD INTO SWRN KS/NWRN OK... ...SYNOPSIS... STRONGEST BELT OF WESTERLIES IS EXPECTED TO REMAIN LOCATED FROM THE PACIFIC NORTHWEST TO NORTH OF THE INTERNATIONAL BORDER INTO CENTRAL AND NERN CANADA. SOUTH OF THIS STRONGER FLOW...A RATHER BROAD MID/UPPER LEVEL TROUGH WILL MOVE SLOWLY ENEWD FROM THE CENTRAL/NRN PLAINS TO THE UPPER MS VALLEY/GREAT LAKES REGION. COMPACT SHORT WAVE TROUGH...CURRENTLY TRACKING SEWD ACROSS THE GREAT LAKES REGION...IS PROGGED TO BE LOCATED OVER ERN NY/PA AT 12Z TUESDAY AND SHOULD WEAKEN AS IT MOVES ACROSS NEW ENGLAND DURING DAY 2. ...SERN CO INTO TX PANHANDLE EWD TO SWRN KS/NWRN OK... THE SRN EXTENT OF A SURFACE TROUGH IS EXPECTED TO REMAIN NEARLY STATIONARY FROM THE TX PANHANDLE ENEWD INTO SWRN KS. STRONG SURFACE HEATING ALONG THIS BOUNDARY WHERE SURFACE DEWPOINTS SHOULD REMAIN IN THE 60S COMBINED WITH STEEP MID LEVEL LAPSE RATES WILL RESULT IN MODERATE INSTABILITY. DESPITE WNWLY MID LEVEL WINDS GENERALLY AT 20-25 KT...ELY LOW LEVEL WINDS LOCATED BENEATH THE MODEST FLOW ALOFT SHOULD SUPPORT 30-35 KT OF DEEP LAYER SHEAR FOR STORM ORGANIZATION. THUNDERSTORMS SHOULD DEVELOP ALONG THIS BOUNDARY TUESDAY AFTERNOON WITH THE POTENTIAL FOR DAMAGING WINDS GIVEN LARGE SURFACE DEWPOINT DEPRESSIONS...AND ALSO A THREAT FOR HAIL DUE TO STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR. ...S CENTRAL KS/N CENTRAL OK NEWD TO MID MS VALLEY/IND... MODELS CONTINUE TO DIFFER IN THE AMPLIFICATION OF THE MID/UPPER LEVEL TROUGH MOVING ACROSS THIS REGION ON TUESDAY...AND THUS RESULTING IN UNCERTAINTY WITH THE STRENGTH OF THE WLY MID LEVEL WINDS AND DEEP LAYER SHEAR. A WEAK SURFACE LOW IS EXPECTED TO BE LOCATED OVER SRN IA/NRN MO AT 12Z TUESDAY WITH A TROUGH EXTENDING SWWD ACROSS KS INTO THE SRN HIGH PLAINS. THE NRN EXTENT OF THIS BOUNDARY IS EXPECTED TO MOVE EWD ACROSS THE MID MS VALLEY REACHING THE LOWER OH VALLEY...WHILE THE SURFACE LOW MOVES INTO THE SRN GREAT LAKES REGION BY 12Z WEDNESDAY. THE SRN EXTENT OF THE SURFACE BOUNDARY IS EXPECTED TO MOVE SLOWLY SWD AND SHOULD STALL ALONG THE OK/KS BORDER INTO SRN MO. THUNDERSTORMS SHOULD BE ONGOING AT THE START OF DAY 2 ACROSS PARTS OF THE CENTRAL PLAINS TO THE MID MS VALLEY WITHIN WAA REGIME ALONG AXIS OF SWLY LLJ. AIR MASS ALONG/S OF ONGOING ACTIVITY FROM SRN KS/NRN OK INTO PARTS OF THE MID MS VALLEY SHOULD BECOME MODERATELY UNSTABLE TUESDAY AFTERNOON. LESS INSTABILITY IS EXPECTED WITH EWD EXTENT INTO IL/IND DUE TO WEAKER LAPSE RATES AND THE POTENTIAL FOR CONVECTIVE CLOUDINESS LIMITING SURFACE HEATING. GIVEN UNCERTAINTIES IN THE STRENGTH OF DEEP LAYER SHEAR...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES EAST OF THE SLIGHT RISK AREA FOR THE POTENTIAL OF ISOLATED STRONG WIND GUSTS AND/OR HAIL. A SLIGHT RISK AREA MAY BE REQUIRED IN LATER OUTLOOKS FOR PARTS OF THIS REGION...IF MODELS AND/OR OBSERVATIONAL DATA SUGGEST STRONGER WLY MID LEVEL WINDS/DEEP LAYER SHEAR. ...DELMARVA REGION TO NEW ENGLAND... IN THE LOW LEVELS...A WEAK SURFACE TROUGH WILL MOVE SLOWLY EWD ACROSS ERN NY/PA INTO NEW ENGLAND AS ASSOCIATED MID LEVEL IMPULSE DE-AMPLIFIES THIS FORECAST PERIOD. POCKETS OF SURFACE HEATING EAST OF THE SURFACE TROUGH COMBINED WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S SHOULD RESULT IN MODERATE INSTABILITY FROM THE DELMARVA REGION NEWD INTO MUCH OF NEW ENGLAND. WEAK MID LEVEL LAPSE RATES AND GENERALLY WEAK DEEP LAYER SHEAR ARE EXPECTED TO LIMIT THE SEVERE POTENTIAL. HOWEVER...A FEW STORMS MAY BECOME STRONG ENOUGH TO PRODUCE AN ISOLATED THREAT OF HAIL/STRONG WIND GUSTS THROUGH TUESDAY AFTERNOON INTO THE EARLY EVENING. ..PETERS.. 07/10/2006  From swody2 at goshenarc.org Mon Jul 10 17:33:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 10 Jul 2006 13:33:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101730 SWODY2 SPC AC 101729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT MON JUL 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE ACROSS PARTS OF THE MID MS/LWR OH VLY.... ...THERE IS A SLGT RISK OF SVR TSTMS LATE TUE AFTN/EVE ACROSS PARTS OF THE S CNTRL HIGH PLAINS.... MODELS INDICATE STRONGER WESTERLIES WITH EMBEDDED SHORT WAVES WILL PERSIST IN A BROAD CYCLONIC BELT FROM THE NORTHEAST PACIFIC THROUGH THE PACIFIC NORTHWEST/NORTHERN ROCKIES INTO THE CENTRAL AND EASTERN CANADIAN PROVINCES. MID/UPPER FLOW ACROSS MUCH OF THE REST OF THE U.S. WILL REMAIN WEAK TUESDAY...BUT RIDGING WILL REMAIN SUPPRESSED AS BROAD UPPER TROUGH IN THE SUBTROPICAL STREAM SHIFTS EASTWARD ACROSS THE MID MISSISSIPPI/OHIO VALLEYS AND GREAT LAKES REGION. DOWNSTREAM SHORT WAVE TROUGH IS PROGGED TO SLOWLY PROGRESS OFF THE NORTH ATLANTIC COAST...WHILE WEAKER IMPULSES UPSTREAM MIGRATE ACROSS PARTS OF THE SOUTHERN PLATEAU/ROCKIES AND HIGH PLAINS. UNCERTAINTIES CONCERNING LOCATION OF PRIMARY CONVECTIVE DEVELOPMENT ARE SIZABLE FOR THIS FORECAST PERIOD...BUT WEAK FRONTAL ZONE ASSOCIATED WITH THE SOUTHERN/SUBTROPICAL STREAMS IS EXPECTED TO PROVIDE THE FOCUS FOR THUNDERSTORM ACTIVITY. ...NEW ENGLAND COASTAL AREAS INTO NRN MID ATLANTIC REGION... POTENTIAL FOR AN ORGANIZED CLUSTER OF STORMS SEEMS LOW...BUT WEAKENING UPPER TROUGH MAY CONTRIBUTE TO SUFFICIENT FORCING/DESTABILIZATION FOR SCATTERED THUNDERSTORMS BY EARLY TUESDAY AFTERNOON. EXPECTED MIXED LAYER CAPE UP TO AROUND 1500 J/KG BY PEAK HEATING IS NOT PARTICULARLY STRONG. HOWEVER...30+ KT SOUTHWESTERLY/WESTERLY MID-LEVEL FLOW COULD CONTRIBUTE TO FAVORABLE SHEAR/STORM MOTIONS FOR ISOLATED STORMS APPROACHING OR BRIEFLY EXCEEDING SEVERE CRITERIA BEFORE STORMS DIMINISH TUESDAY EVENING WITH LOSS OF INSOLATION. ...MID MISSISSIPPI/LOWER OHIO VALLEY... MAGNITUDE OF DESTABILIZATION IS UNCERTAIN DUE TO LIKELIHOOD OF CONSIDERABLE CLOUD COVER AND WEAK LAPSE RATES. HOWEVER...BOUNDARY LAYER DEW POINTS AROUND 70F WILL STILL PROBABLY BE SUPPORTIVE OF MIXED LAYER CAPE AT OR ABOVE 1000 J/KG WITH AT LEAST SOME INSOLATION. AND...MODELS SUGGEST A BELT OF 30-40 KT WEST SOUTHWESTERLY LOWER/MID TROPOSPHERIC FLOW WITH AN IMPULSE ACCOMPANYING UPPER TROUGH...WHICH MAY PROVIDE SUFFICIENT FORCING FOR AN ORGANIZED CONVECTIVE CLUSTER. THERMODYNAMIC ENVIRONMENT DOES NOT APPEAR LIKELY TO BE SUPPORTIVE OF LARGE HAIL...BUT POTENTIAL EXISTS FOR A SWATH OF DAMAGING WINDS APPROACHING OR EXCEEDING SEVERE CRITERIA...PARTICULARLY AS ACTIVITY PROGRESSES ACROSS ILLINOIS/INDIANA DURING THE PEAK HEATING HOURS. ...SOUTHERN CENTRAL PLAINS... MID/UPPER FORCING FOR CONVECTIVE DEVELOPMENT IS UNCERTAIN...BUT SURFACE LOW NEAR INTERSECTION OF FRONT/LEE TROUGH ACROSS THE TEXAS PANHANDLE REGION COULD PROVIDE THE FOCUS FOR CONVECTIVE DEVELOPMENT LATE TUESDAY AFTERNOON. ACTIVITY WILL PROBABLY INITIATE AS CONVECTIVE TEMPERATURES ARE REACHED IN ENVIRONMENT WITH MIXED LAYER CAPE OF 1000-2000 J/KG. STRENGTH OF DEEP LAYER SHEAR IS IN QUESTION...BUT FAVORABLE LOW-LEVEL CONVERGENCE/WARM ADVECTION COULD AID CONSOLIDATION OF ACTIVITY INTO A LARGE CONVECTIVE CLUSTER. AND...STEEP LAPSE RATES/HOT BOUNDARY LAYER WILL BE CONDUCIVE FOR A FEW DOWNBURSTS AND STRONG GUSTY WINDS ALONG OUTFLOWS. SOME HAIL IS ALSO POSSIBLE IN STRONGER CELLS...BEFORE THEY DIMINISH IN INTENSITY TUESDAY EVENING. ..KERR.. 07/10/2006  From swody2 at goshenarc.org Tue Jul 11 06:14:16 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 11 Jul 2006 02:14:16 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110610 SWODY2 SPC AC 110609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT TUE JUL 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL APPALACHIANS INTO SWRN NEW ENGLAND... ...SYNOPSIS... BROAD POSITIVELY TILTED MID LEVEL TROUGH IS EXPECTED TO MOVE EWD FROM THE GREAT LAKES/MID MS VALLEY ACROSS THE OH VALLEY AND TOWARD NEW ENGLAND. MEANWHILE...PRIMARY BELT OF WESTERLIES IS EXPECTED TO EXTEND FROM THE PACIFIC NW INTO SRN AND ERN CANADA. MODELS REMAIN DIFFERENT WITH THE TIMING OF A SHORT WAVE TROUGH EXPECTED TO TRANSLATE ENEWD ACROSS THE NRN HIGH PLAINS TO SOUTH CENTRAL CANADA DURING DAY 2 FORECAST PERIOD. NAM/NAMKF INDICATED A MID LEVEL SHORT WAVE TROUGH AND ATTENDANT SURFACE LOW APPROACHING THE E/SE COAST OF FL WEDNESDAY AFTERNOON... WITH THIS SYSTEM THEN TURNING NWD ALONG THE N FL COAST WEDNESDAY NIGHT. IF THIS SYSTEM DOES DEVELOP AS FORECAST BY THE NAM/NAMKF... AND MOVES CLOSER TO THE COAST THAN CURRENTLY FORECAST ENHANCING LOW LEVEL DIRECTIONAL SHEAR...THEN SEVERE PROBABILITIES MAY BE REQUIRED IN LATER OUTLOOKS. ...SRN NEW ENGLAND TO CENTRAL APPALACHIANS AND OH VALLEY... IN THE LOW LEVELS...A SURFACE LOW ASSOCIATED WITH THE BROAD MID LEVEL TROUGH IS EXPECTED TO BE LOCATED OVER THE SRN GREAT LAKES REGION AT 12Z WEDNESDAY. THIS LOW IS FORECAST TO TRACK EWD REACHING SRN NEW ENGLAND BY 12Z THURSDAY...WHILE THE TRAILING SURFACE BOUNDARY SPREADS EWD ACROSS NY/PA AND SWD INTO THE OH VALLEY. THUNDERSTORMS ARE EXPECTED TO BE ONGOING ALONG/AHEAD OF THE SURFACE TROUGH AT 12Z WEDNESDAY FROM THE LOWER GREAT LAKES REGION SWWD THROUGH THE OH VALLEY IN ASSOCIATION WITH WAA ALONG A 40-50 KT SWLY LLJ AXIS. AIR MASS DOWNSTREAM OF THIS INITIAL ACTIVITY IS EXPECTED TO DESTABILIZE GIVEN RICH MOISTURE /SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70/ ADVECTION AND SURFACE HEATING ESPECIALLY ACROSS THE SRN HALF OF THE SLIGHT RISK AREA. WEAK MID LEVEL LAPSE RATES SHOULD LIMIT THE DEVELOPMENT OF STRONGER INSTABILITY WITH MLCAPE RANGING FROM 500-1000 J/KG. DESPITE POTENTIAL FOR MARGINAL INSTABILITY...STRONG /40-50 KT/ WSWLY LOW-MID LEVEL WINDS SHOULD COMPENSATE FOR THIS LIMITING FACTOR...AND SUPPORT A THREAT FOR DAMAGING WINDS AS ONGOING STORMS AND/OR NEW LINE SEGMENTS DEVELOP EWD ACROSS THE SLIGHT RISK AREA. STRONG DEEP LAYER SHEAR ALSO SUGGESTS SUPERCELLS WILL BE POSSIBLE WITH STRONG LOW LEVEL SHEAR VALUES SUPPORTING A TORNADO THREAT...ESPECIALLY ACROSS NRN MD/ERN PA TO SERN NY WHERE INSTABILITY SHOULD BE MAXIMIZED AND MLCAPE POTENTIALLY REACH 1500 J/KG. FARTHER SOUTHWEST THROUGH THE OH VALLEY...THE AIR MASS SHOULD BECOME MODERATELY UNSTABLE SOUTH OF INITIAL CONVECTIVE ACTIVITY SUPPORTING NEW THUNDERSTORMS THROUGH DAY 2. WEAKER DEEP LAYER SHEAR WITH SWWD EXTENT IS EXPECTED TO LIMIT THE SEVERE WEATHER THREAT ACROSS THE OH VALLEY. ...PLAINS STATES... SLY LOW LEVEL FLOW ACROSS THE PLAINS STATES IS EXPECTED TO ADVECT MOISTURE NWD...WHILE STRONG SURFACE HEATING AND DEEP BOUNDARY LAYER MIXING WITHIN THIS AIR MASS SHOULD RESULT IN LARGE SURFACE TEMPERATURE/DEWPOINT SPREADS BY PEAK HEATING WEDNESDAY AFTERNOON. STEEP LAPSE RATES WILL SUPPORT MODERATE INSTABILITY /MLCAPE 1500-2500 J/KG/ DEVELOPING FROM OK AND TX PANHANDLE NWD TO THE DAKOTAS. IN ADDITION TO MODEL DIFFERENCES WITH THE TIMING OF THE MID LEVEL IMPULSE TO AFFECT THE NRN PLAINS...THERE IS LARGE MODEL SPREAD IN THE SPEED OF WLY MID LEVEL FLOW EXPECTED ACROSS THE CENTRAL/SRN PLAINS. DESPITE THESE DIFFERENCES...THIS OUTLOOK WILL INDICATE LOW SEVERE PROBABILITIES...GIVEN THAT EVEN WEAK DEEP LAYER SHEAR /20-25 KT/ WITHIN A MODERATELY UNSTABLE ENVIRONMENT WILL SUPPORT A FEW SEVERE STORMS. ACTIVITY SHOULD BE FOCUSED ALONG THE LEE TROUGH WHICH WILL MOVE EWD INTO THE NRN PLAINS BY LATER IN THE FORECAST PERIOD. A FEW SEVERE STORMS WILL ALSO BE POSSIBLE ALONG A TRAILING COLD FRONT INTO SRN MT WHERE DEEP LAYER SHEAR WILL BE SUFFICIENT FOR ORGANIZED STORMS...BUT INSTABILITY MAY BE WEAKER. ..PETERS.. 07/11/2006  From swody2 at goshenarc.org Wed Jul 12 17:36:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 12 Jul 2006 13:36:51 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121735 SWODY2 SPC AC 121734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT WED JUL 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN AND CENTRAL PLAINS... ...SYNOPSIS... UPPER RIDGE WILL REMAIN OVER THE SWRN U.S. THIS PERIOD...WHILE SEVERAL UPPER DISTURBANCES MOVE W-E ACROSS THE CENTRAL AND NRN CONUS WITH BELT OF WLYS N OF UPPER RIDGE. AT THE SURFACE...A COLD FRONT WILL SHIFT EWD ACROSS THE NORTHEAST AHEAD OF A FAIRLY PRONOUNCED UPPER TROUGH...WHILE A SECOND FRONT/TROUGH CROSSES THE PLAINS AHEAD OF A SECOND SHORT-WAVE FEATURE. ...THE PLAINS... STEEP LAPSE RATES ABOVE A MOIST BOUNDARY LAYER SHOULD RESULT IN MODERATE TO STRONG INSTABILITY BY AFTERNOON ACROSS THE PLAINS. AS MORE PRONOUNCED SHORT-WAVE TROUGH ENTERS THE PLAINS IN THE WAKE OF EARLIER FEATURE...STORMS SHOULD INITIATE ALONG SURFACE FRONT/LEE TROUGH BY AFTERNOON. THOUGH ENHANCED FLOW ALOFT IS FORECAST ALONG WRN FRINGE OF SHORT-WAVE FEATURE...IT APPEARS ATTM THAT STRONGEST FLOW WILL REMAIN BEHIND THE SURFACE BOUNDARY AND ASSOCIATED ZONE OF CONVECTIVE INITIATION. NONETHELESS...LOW-LEVEL VEERING SHOULD YIELD SUFFICIENT SHEAR -- GIVEN DEGREE OF INSTABILITY -- FOR MULTICELL AND/OR WEAKLY-ROTATING STORMS. ALONG WITH POTENTIAL FOR LARGE HAIL GIVEN DEGREE OF INSTABILITY...LOCALLY-DAMAGING WINDS WILL ALSO BE POSSIBLE DUE TO POTENTIAL FOR LOW-LEVEL EVAPORATIVE COOLING GIVEN SURFACE TEMPERATURES FORECAST TO CLIMB INTO THE 90S. STORMS SHOULD CONTINUE/SHIFT SEWD ACROSS THE PLAINS OVERNIGHT AS LOW-LEVEL JET VEERS -- WITH SOME SEVERE THREAT POSSIBLY LINGERING THROUGH THE END OF THE PERIOD. ...SRN NEW ENGLAND/THE MID-ATLANTIC REGION... MARGINAL AIRMASS DESTABILIZATION IS FORECAST ALONG EWD-MOVING COLD FRONT DURING THE AFTERNOON...AS UPPER SHORT-WAVE TROUGH CROSSES THE NERN CONUS. ATTM...IT APPEARS THE STRONGER FLOW AND GREATER LOW-LEVEL CONVERGENCE ALONG FRONT WILL EXIST ACROSS SRN NEW ENGLAND -- WHERE INSTABILITY SHOULD BE WEAKER /AOB 500 J/KG MEAN-LAYER CAPE/. FURTHER S INTO THE MID-ATLANTIC REGION...WEAKER WSWLY FLOW THROUGH THE LOWER TROPOSPHERE -- MORE PARALLEL TO SURFACE FRONT -- SUGGESTS WEAKER LOW-LEVEL CONVERGENCE AND WEAKER SHEAR DESPITE SOMEWHAT MORE UNSTABLE AIRMASS. THEREFORE -- THOUGH A LIMITED SEVERE THREAT APPEARS POSSIBLE ALONG THE SURFACE BOUNDARY FROM SRN NEW ENGLAND SWWD INTO SWRN VA...OVERALL SEVERE POTENTIAL APPEARS TO BE BELOW SLIGHT RISK THRESHOLD ATTM. ...OZARKS INTO THE MID MS VALLEY... THUNDERSTORMS ARE FORECAST TO REDEVELOP ALONG REMNANT BAROCLINIC ZONE -- WHICH SHOULD EXTEND FROM THE TN VALLEY REGION WWD INTO THE CENTRAL PLAINS...AS AIRMASS BECOMES MODERATELY UNSTABLE DURING THE AFTERNOON. THOUGH DEEP-LAYER WILL REMAIN WEAK ACROSS THIS REGION...A FEW PULSE-TYPE SEVERE STORMS CAPABLE OF HAIL OR BRIEFLY-DAMAGING WIND GUSTS WILL BE POSSIBLE. ..GOSS.. 07/12/2006  From swody2 at goshenarc.org Thu Jul 13 06:11:06 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 13 Jul 2006 02:11:06 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130608 SWODY2 SPC AC 130607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT THU JUL 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SHORT WAVE TROUGH OVER THE UPPER/MID MS VALLEY AND EXTENDING NWD INTO CANADA AT 12Z FRIDAY IS PROGGED TO DE-AMPLIFY AS IT TRACKS EWD ACROSS THE GREAT LAKES REGION AND ONTARIO...WITH A RIDGE BUILDING NNEWD IN ITS WAKE. THE SRN EXTENT OF THIS TROUGH SHOULD BECOME DETACHED FROM THE PRIMARY BELT OF WESTERLIES...WHICH WILL BE FARTHER TO THE NORTH...AND MOVE SLOWLY SEWD OVER THE MID MS VALLEY. IN THE NORTHEAST...A WEAK SHORT WAVE TROUGH IS EXPECTED TO TRACK SEWD ACROSS NRN NEW ENGLAND WITHIN MODERATE NWLY FLOW REGIME DURING THE FIRST HALF OF DAY 2. ...MAINE... A SURFACE TROUGH IS EXPECTED TO MOVE SEWD ACROSS MAINE FRIDAY MORNING/EARLY AFTERNOON. DESPITE SURFACE HEATING AHEAD OF THIS BOUNDARY COMBINED WITH RICH MOISTURE /SURFACE DEWPOINTS IN THE 60S/...WEAK LAPSE RATES SUGGEST INSTABILITY SHOULD REMAIN MARGINAL /MUCAPE GENERALLY BELOW 1000 J/KG/. ASCENT AHEAD OF THE WEAK MID LEVEL SHORT WAVE TROUGH WILL SUPPORT THUNDERSTORMS MAINLY OVER SRN/ERN MAINE AS THE SURFACE BOUNDARY MOVES SEWD DURING THE LATE MORNING INTO THE AFTERNOON. DEEP LAYER SHEAR IS EXPECTED TO BE SUFFICIENT FOR A FEW ORGANIZED STORMS GIVEN 30-40 KT OF NWLY MID LEVEL FLOW. ...PARTS OF CENTRAL/NRN WI INTO WRN U.P. OF MI... ALTHOUGH HEIGHTS WILL BE RISING ACROSS THIS REGION ON FRIDAY... RESIDUAL SURFACE MOISTURE AND SURFACE HEATING ARE EXPECTED TO RESULT IN MODERATE INSTABILITY ACROSS PARTS OF WI INTO THE WRN U.P. OF MI. WEAK LOW LEVEL WAA ACROSS THIS REGION FRIDAY AFTERNOON SHOULD SUPPORT A FEW THUNDERSTORMS. MODERATE NWLY FLOW /30 KT/ SUGGESTS DEEP LAYER SHEAR WILL BE SUFFICIENT FOR STORMS TO BECOME ORGANIZED...WITH AN ATTENDANT THREAT OF ISOLATED HAIL AND/ OR STRONG WIND GUSTS. ...PARTS OF CENTRAL/NORTH CENTRAL MT... A SHORT WAVE TROUGH IS EXPECTED TO TRACK ENEWD FROM THE PACIFIC NORTHWEST GRAZING NRN MT DURING THE LATE AFTERNOON INTO THE EVENING. COLD FRONT ASSOCIATED WITH THIS MID LEVEL TROUGH SHOULD MOVE INTO CENTRAL/NRN MT BY 15/00Z. ALTHOUGH LOW LEVELS WILL BE RATHER DRY... POINT FORECAST SOUNDINGS SUGGEST STEEP MID LAPSE RATES WILL RESULT IN MARGINAL INSTABILITY. STRONG SWLY MID LEVEL WINDS /50-60 KT/ AND THE LIKELIHOOD FOR A DEEP WELL MIXED BOUNDARY LAYER WITH LARGE SURFACE TEMPERATURE/DEWPOINT SPREADS...ANY STORMS THAT DEVELOP INTO THE EVENING MAY PRODUCE STRONG WIND GUSTS. ISOLATED HAIL WILL ALSO BE POSSIBLE...GIVEN STEEP LAPSE RATES AND STRONG DEEP LAYER SHEAR. ..PETERS.. 07/13/2006  From swody2 at goshenarc.org Thu Jul 13 17:50:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 13 Jul 2006 13:50:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131748 SWODY2 SPC AC 131746 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 PM CDT THU JUL 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID/LOWER OH VALLEY AND VICINITY... ...SYNOPSIS... LARGE UPPER HIGH WILL PREVAIL ACROSS THE WRN CONUS...WHILE A SHORT-WAVE TROUGH WILL MOVE EWD ACROSS THE MID AND UPPER MS/OH VALLEYS AND GREAT LAKES AND SWD ACROSS THE PLAINS ON ERN PERIPHERY OF THE RIDGE. MEANWHILE...SMALLER-SCALE DISTURBANCES SHOULD MOVE SEWD ACROSS THE NORTHEAST WITHIN NWLY FLOW REGIME. MAIN SURFACE FEATURE WILL BE A COMBINATION SURFACE FRONT/CONVECTIVE OUTFLOW BOUNDARY AHEAD OF SHORT-WAVE TROUGH CROSSING THE CENTRAL CONUS. THOUGH EXACT LOCATION OF THIS BOUNDARY WILL DEPEND UPON LOCATION AND INTENSITY OF ONGOING STORMS...THIS FEATURE SHOULD MOVE EWD ACROSS THE MIDWEST...SEWD ACROSS THE MID MS VALLEY...AND SWD ACROSS THE SRN PLAINS THROUGH THE PERIOD. ...MID AND LOWER OH/MID MS VALLEY REGIONS... UPPER SHORT-WAVE TROUGH IS FORECAST TO MOVE EWD ACROSS THE MS/OH VALLEYS AND GREAT LAKES REGION THIS PERIOD...AFFECTING AREAS AS FAR S AS THE TN VALLEY. THOUGH ASSOCIATED COLD FRONT SHOULD BE WEAK...POTENTIAL FOR A STRONGER SURFACE BOUNDARY EXISTS DEPENDING UPON THE EVOLUTION OF CONVECTION AND ASSOCIATED OUTFLOW LATE IN THE DAY 1 PERIOD. IN ANY CASE...MOIST AIRMASS WILL BE IN PLACE ACROSS THE REGION...WITH MODELS INDICATING A BELT OF ENHANCED/ROUGHLY UNIDIRECTIONAL LOWER TO MID-LEVEL FLOW /AROUND 30 KT/ ACROSS THE LOWER OH VALLEY REGION. SCENARIO IS COMPLICATED GIVEN CONVECTION WHICH SHOULD BE ONGOING...BUT ATTM IT APPEARS THAT SUFFICIENT INSTABILITY WILL DEVELOP AHEAD OF FRONT/CONVECTIVE OUTFLOW SOMEWHERE WITHIN A ZONE FROM INDIANA/WRN OH INTO CENTRAL AND WRN KY AND PERHAPS SRN IL/SERN MO/NRN TN. THIS COMBINED WITH MODERATE WLY FLOW SUGGESTS AN ENHANCED POTENTIAL FOR DAMAGING WINDS...AND THUS WILL INTRODUCE A SLIGHT RISK ACROSS THIS REGION. FURTHER N INTO THE UPPER GREAT LAKES...NW ACROSS IL/IA...AND SW INTO SRN MO/NRN AR...SCENARIO REMAINS MORE COMPLEX DUE TO LIKELIHOOD FOR ONGOING CONVECTION. WILL INCLUDE A LARGE 5% SEVERE THREAT AREA THIS FORECAST TO ACCOUNT FOR SEVERE POTENTIAL...WITH ANY POSSIBILITY FOR GREATER SEVERE THREAT IN THESE AREAS LARGELY DEPENDENT UPON EVOLUTION OF DAY 1 CONVECTION. ...SRN PLAINS WWD INTO ERN NM... STRONG HEATING IS FORECAST S OF OUTFLOW-REINFORCED SURFACE BOUNDARY WHICH SHOULD BE MOVING ACROSS OK/THE TX PANHANDLE DURING THE DAY...AS UPPER VORT MAX MOVES SWD/SWWD AROUND ERN PERIPHERY OF UPPER HIGH. SUFFICIENT MOISTURE/INSTABILITY ALONG THE SURFACE FRONT SHOULD ALLOW ONGOING THUNDERSTORMS EARLY IN THE PERIOD TO PERSIST -- AND THEN INCREASE DURING THE AFTERNOON COINCIDENT WITH DIURNAL HEATING. THOUGH FLOW ALOFT WILL BE RELATIVELY WEAK...SLY FLOW AT LOW LEVELS BENEATH UPPER NLYS MAY PROVIDE SUFFICIENT SHEAR FOR SOME STORM ORGANIZATION. THIS COMBINED WITH HOT/DEEP MIXED LAYER SUGGESTS A POTENTIAL FOR ISOLATED DAMAGING GUSTS. WILL THEREFORE INTRODUCE 5% SEVERE PROBABILITY ACROSS THIS AREA...WITH SOME POTENTIAL FOR A SLIGHT RISK UPGRADE IN LATER FORECASTS. ...NRN NEW ENGLAND... MODERATE NWLY FLOW ALOFT IS FORECAST ACROSS NEW ENGLAND ON BACK SIDE OF MAIN UPPER TROUGH OFFSHORE. TIMING OF SMALLER-SCALE DISTURBANCES MOVING SEWD ACROSS NEW ENGLAND REMAINS DIFFICULT...BUT MODELS HINT THAT ONE FEATURE MAY CROSS THE REGION EARLY IN THE DAY...AND A SECOND FEATURE MAY APPROACH LATE IN THE AFTERNOON. DESPITE QUESTIONS REGARDING TIMING...POTENTIAL FOR SUFFICIENT DESTABILIZATION AND MODERATE FLOW ALOFT SUPPORT MAINTAINING 5% SEVERE PROBABILITY ACROSS THIS REGION. ...N CENTRAL MT... VERY SUBTLE UPPER DISTURBANCES ARE FORECAST TO MOVE EWD ACROSS SERN BRITISH COLUMBIA/SRN ALBERTA/SRN SASKATCHEWAN DURING THE DAY...WITHIN FAST BELT OF WEAKLY ANTICYCLONIC FLOW AROUND NRN PERIPHERY OF WRN U.S. RIDGE. LOW-LEVEL BAROCLINIC ZONE IS FORECAST TO LIE ACROSS ID/MT...THOUGH DESTABILIZATION ALONG THIS FRONT IS FORECAST TO BE MINIMAL AT BEST. COULD A FEW ISOLATED STORMS INITIATE OVER THE HIGHER TERRAIN OF MT...STRENGTH OF FLOW ALOFT WOULD SUPPORT A THREAT FOR DAMAGING WINDS. HOWEVER...GIVEN MEAGER INSTABILITY AND POTENTIAL THAT ANY STORMS WILL REMAIN N OF THE CANADA/U.S. BORDER...WILL MAINTAIN ONLY A SMALL CONDITION 5% SEVERE THREAT ACROSS THIS REGION. ..GOSS.. 07/13/2006  From swody2 at goshenarc.org Fri Jul 14 06:06:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 14 Jul 2006 02:06:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140604 SWODY2 SPC AC 140603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0103 AM CDT FRI JUL 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AN ELONGATED DOMINANT ZONE OF HIGH PRESSURE ALOFT WILL BUILD EWD ACROSS THE OH VALLEY DURING THE DAY2 PERIOD IN THE WAKE OF WEAK UPPER TROUGH. LARGE SCALE SUBSIDENCE AND WARM TEMPERATURES ALOFT WILL PROVE HOSTILE FOR ORGANIZED DEEP CONVECTION ACROSS MUCH OF THE MID SECTION OF THE U.S. ...NERN U.S... DOWNSTREAM...THUNDERSTORMS SHOULD DEVELOP EASILY AHEAD OF UPPER TROUGH AXIS OVER PORTIONS OF THE NERN U.S. WHERE MID LEVELS WILL REMAIN FAVORABLY COOL AND BOUNDARY LAYER TEMPERATURES WILL WARM RAPIDLY BY MID DAY. DESPITE WEAK LOW LEVEL CONVERGENCE IT APPEARS THERE MAY BE A ZONE OF ENHANCED THUNDERSTORM ACTIVITY FROM ERN NY INTO ME...AIDED BY UPPER TROUGH AND JUST ENOUGH DEEP LAYER SHEAR FOR A FEW STRONG THUNDERSTORMS. ...UPPER MS VALLEY... PLUME OF VERY WARM TEMPERATURES WILL ADVECT OFF THE NRN ROCKIES/HIGH PLAINS REGION NEWD INTO THE ERN DAKOTAS SATURDAY. LATEST MODEL GUIDANCE INDICATES BOUNDARY LAYER PARCELS WILL STRUGGLE TO REACH THEIR LFC UNTIL LATE IN THE AFTERNOON WHEN SFC TEMPERATURES SOAR TO NEAR OR ABOVE 100F. IN THE ABSENCE OF HEIGHT FALLS ACROSS THIS REGION ANY STORMS THAT DEVELOP ALONG A WIND SHIFT FROM NWRN MN INTO ERN ND MAY PROVE SHORT LIVED...ALTHOUGH GUSTY WINDS ARE POSSIBLE. OTHERWISE...MAJORITY OF CONVECTION SHOULD DEVELOP FARTHER NORTHEAST WITHIN WARM ADVECTION ZONE OVER WRN ONTARIO. ...AZ... RATHER LARGE UPPER LEVEL CIRCULATION IS MOVING WWD ACROSS THE WRN GULF OF MEXICO AND SHOULD PROGRESS ACROSS THE BODY OF MEXICO OVER THE NEXT COUPLE OF DAYS. MOISTURE SHOULD GRADUALLY RETURN NWWD INTO PORTIONS OF THE SWRN U.S. WHERE ELY FLOW SHOULD STRENGTHEN AND PROVIDE SUFFICIENT SHEAR FOR MULTICELL STORM STRUCTURES. GUSTY WINDS WILL BE POSSIBLE WITH MOISTENING CONVECTION ACROSS THIS REGION. ..DARROW.. 07/14/2006  From swody2 at goshenarc.org Mon Jul 17 06:00:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 17 Jul 2006 02:00:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170557 SWODY2 SPC AC 170556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON JUL 17 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NERN U.S. AND OH VALLEY... ...OH VALLEY/NERN U.S... DEEP WLY FLOW AROUND THE NRN PERIPHERY OF DOMINANT UPPER HIGH WILL ALLOW STEEP LAPSE RATE PLUME TO SPREAD ACROSS SRN ONTARIO INTO PORTIONS OF THE NERN U.S...IN ADDITION TO THE OH VALLEY REGION. WITH SUBSTANTIAL BOUNDARY LAYER MOISTURE IN PLACE...THERMODYNAMIC PROFILES WILL PROVE MORE THAN ADEQUATE FOR ROBUST CONVECTION TUESDAY. IT APPEARS HEIGHT FALLS IN ASSOCIATION WITH PROGRESSIVE UPPER TROUGH WILL DEVELOP ACROSS MUCH OF THE NERN U.S. EARLY IN THE PERIOD ALLOWING SFC FRONT TO ADVANCE ACROSS ONTARIO/QUEBEC INTO NRN NEW ENGLAND...SWWD INTO OH BY 18Z. THUNDERSTORMS SHOULD READILY DEVELOP ALONG THIS ZONE OF CONVERGENCE AND SPREAD ESEWD AT ROUGHLY 30-40KT. DAMAGING WINDS APPEAR LIKELY WITH THIS ACTIVITY GIVEN STEEP LAPSE RATE ENVIRONMENT AND STORM MOTIONS. AT THIS TIME WILL MAINTAIN MODEST SEVERE PROBABILITIES FOR THIS ACTIVITY. HOWEVER...WIND PROBABILITIES MAY NEED TO BE INCREASED IN LATER OUTLOOKS AS ORGANIZED SQUALL LINE STRUCTURE WITHIN THIS DEVELOPING FLOW REGIME MAY ULTIMATELY PRODUCE MORE WIDESPREAD SEVERE. ...NRN PLAINS/UPPER-MID MS VALLEY... ANOTHER IN A SERIES OF UPPER SHORTWAVE TROUGHS WILL ADVECT ACROSS THE NRN ROCKIES/SRN CANADA TOWARD THE UPPER MS VALLEY LATE IN THE PERIOD. THIS FEATURE WILL ENHANCE LOW LEVEL WARM ADVECTION ACROSS THE PLAINS INTO MN AS LLJ INCREASES...ESPECIALLY AFTER DARK. IT APPEARS THUNDERSTORMS WILL DEVELOP WITHIN THIS EVOLVING ASCENT REGION DURING THE OVERNIGHT HOURS...POSSIBLY ORGANIZING INTO AN MCS BY MORNING OVER PORTIONS OF ERN SD INTO SRN MN AND NRN IA. IT'S NOT ENTIRELY CLEAR WHETHER THIS ACTIVITY WILL BE SEVERE IN NATURE GIVEN THE HIGH THICKNESS VALUES AND INTENSE HEAT AIRMASS THIS CONVECTION WILL ULTIMATELY EVOLVE FROM. LATE AFTERNOON STORMS COULD FORM ALONG WIND SHIFT OVER WRN SD WHERE STEEP LAPSE RATE ENVIRONMENT WILL RESULT IN HIGH BASED INVERTED-V TYPE ACTIVITY. STRENGTHENING LLJ MAY ULTIMATELY ALLOW THIS CONVECTION TO PROPAGATE EWD DURING THE OVERNIGHT HOURS WHERE STRUCTURES SHOULD BECOME ELEVATED IN NATURE FARTHER EAST. GUSTY WINDS SHOULD BE THE PRIMARY SEVERE THREAT. ..DARROW.. 07/17/2006  From swody2 at goshenarc.org Mon Jul 17 17:23:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 17 Jul 2006 13:23:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 171721 SWODY2 SPC AC 171720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 PM CDT MON JUL 17 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND INTO THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLAINS... ...SYNOPSIS... STRONGER WESTERLY FLOW ALOFT WILL REMAIN ALONG THE NRN TIER OF STATES AS TWO SHORT WAVE TROUGHS PROGRESS EWD ACROSS THE CANADIAN/US BORDER. LEAD SHORT WAVE CURRENTLY APPROACHING THE UPPER GREAT LAKES WILL MOVE FROM WRN QUEBEC AND THE LOWER GREAT LAKES EWD ACROSS THE ST LAWRENCE VALLEY/NRN NEW ENGLAND TOMORROW...AS UPSTREAM TROUGH MOVES ACROSS THE SRN CANADIAN PRAIRIE PROVINCES. FARTHER SOUTH...LOW LATITUDE TROUGH IN THE SUBTROPICAL EASTERLIES WILL CONTINUE WWD INTO THE PACIFIC OFF NRN BAJA AS INVERTED TROUGH MOVE NWWD ACROSS CENTRAL/SRN CA. AT THE SURFACE...A COLD FRONT WILL MOVE SEWD ACROSS NEW ENGLAND AND THE OH VALLEY. THE WRN PART OF THE FRONT WILL BEGIN TO LIFT NWD DURING THE EVENING AS A LOW CENTER DEVELOPS EWD INTO NRN NEB/SRN SD...AND A SECOND COLD FRONT MOVES SEWD ACROSS THE DAKOTAS. ...NERN STATES/OH VALLEY... AMPLE LOW LEVEL MOISTURE WITH SURFACE DEW POINTS IN THE UPPER 60S/LOWER 70S WILL BE PRESENT AHEAD OF THE ADVANCING COLD FRONT...BENEATH AN ELEVATED MIXED LAYER PLUME EXTENDING EWD FROM THE PLAINS INTO PARTS OF NEW ENGLAND. THE STEEP MID LEVEL LAPSE RATES ABOVE THE LOW LEVEL MOISTURE LAYER WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPE OF 1500-2500 J/KG AND PROVIDE A VERY FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT. A BAND OF THUNDERSTORMS IS EXPECTED TO BE ONGOING IN THE MORNING ALONG THE COLD FRONT FROM THE LOWER GREAT LAKES NEWD INTO NRN NEW ENGLAND. THE CAPPING INVERSION ASSOCIATED WITH THE EML IN SRN NEW ENGLAND IS EXPECTED TO INHIBIT CONVECTIVE INITIATION IN THE WARM SECTOR SOUTH OF THE FRONT DURING THE MORNING. STORMS ALONG/IMMEDIATELY AHEAD OF THE FRONT ARE LIKELY TO INTENSIFY BY MID/LATE MORNING AS STRONG INSOLATION DESTABILIZES THE PRE-CONVECTIVE ENVIRONMENT...AND DYNAMIC FORCING FOR LARGE SCALE ASCENT INCREASES WITHIN RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET MOVING ACROSS THE ST LAWRENCE VALLEY. ALTHOUGH THE STRONGEST VERTICAL SHEAR WILL BE LOCATED PRIMARILY NORTH OF THE COLD FRONT...DEEP LAYER SHEAR OF 25-35 KT WILL BE SUFFICIENT TO ENHANCE CONVECTIVE ORGANIZATION WITH POTENTIAL FOR A FEW SUPERCELLS TO DEVELOP...ESPECIALLY OVER PARTS OF NEW ENGLAND/SERN NY INTO NRN PA. UNIDIRECTIONAL WIND PROFILES ABOVE THE PBL SUGGEST PRIMARY CONVECTIVE MODE WILL BE IN THE FORM OF LINE SEGMENTS INCLUDING EMBEDDED BOW ECHOES GIVEN THE DRY AIR WITHIN THE ELEVATED MIXED LAYER AND ENHANCED POTENTIAL FOR STRONG DOWNDRAFTS. ALTHOUGH VERTICAL SHEAR DECREASES WITH WWD EXTENT ACROSS THE OH VALLEY...SUFFICIENT INSTABILITY/DRY AIR ALOFT SUGGESTS POTENTIAL FOR A FEW SEVERE STORMS INTO PARTS OF THE OH VALLEY. SEVERE THREAT IS EXPECTED TO DIMINISH BY 03-06Z. ...NRN PLAINS INTO UPPER MS VALLEY... THE ELEVATED MIXED LAYER WILL PERSIST FROM THE ROCKIES INTO THE NRN PLAINS TOMORROW...EFFECTIVELY CAPPING DEVELOPMENT OF SURFACE-BASED CONVECTION THROUGH MOST OF THE PERIOD. AS THE WARM FRONT LIFTS NWD ACROSS THE LOWER/MIDDLE MO RIVER VALLEY DURING THE LATE AFTERNOON INTO THE OVERNIGHT HOURS...MOISTURE WILL RETURN NWD INTO IA/ERN NEB/CENTRAL AND ERN SD/SRN MN BENEATH THE EML. ALTHOUGH THERE IS POTENTIAL FOR ISOLATED HIGH-BASED THUNDERSTORMS TO DEVELOP EWD ACROSS THE NRN HIGH PLAINS DURING THE LATE AFTERNOON AND EVENING WITH AN ATTENDANT THREAT FOR LOCAL MICROBURSTS...THE PRIMARY ELEVATED CONVECTIVE DEVELOPMENT IS EXPECTED DURING THE OVERNIGHT HOURS AS WARM ADVECTION LIFT INCREASES NORTH OF THE WARM FRONT AS THE NOCTURNAL LOW LEVEL JET INTENSIFIES. VERTICAL WIND PROFILES ARE FORECAST TO EXHIBIT PRONOUNCED VEERING WITH HEIGHT AS A STRONG MID LEVEL JET STREAK ASSOCIATED WITH THE NEXT SHORT WAVE TROUGH MOVES EWD ACROSS THE NRN PLAINS. THIS WILL PROVIDE SUFFICIENT SHEAR TO SUPPORT ISOLATED ELEVATED SUPERCELLS AFTER 03-06Z...WITH STRONGER CELLS CAPABLE OF PRODUCING LARGE HAIL. ..WEISS.. 07/17/2006  From swody2 at goshenarc.org Tue Jul 18 05:44:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 01:44:24 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180541 SWODY2 SPC AC 180540 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1240 AM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES REGION... DOMINANT UPPER RIDGE WILL REMAIN ANCHORED OVER THE CNTRL PLAINS WHILE TRANSITORY SHORTWAVES RIPPLE EWD ALONG THE U.S./CANADIAN BORDER. ANOTHER SIGNIFICANT TROUGH...AND ASSOCIATED SPEED MAX...WILL APPROACH THE UPPER MS VALLEY/UPPER GREAT LAKES REGION DURING THE LATTER HALF OF THE PERIOD FORCING A SFC COLD FRONT INTO NWRN MN...TRAILING SWWD INTO ERN SD BY MID DAY. EARLY IN THE PERIOD...STRONG LOW LEVEL WARM ADVECTION AND A FOCUSED LLJ INTO SERN SD/SWRN MN WILL LIKELY ENHANCE MCS-TYPE CONVECTION ALONG ERN EDGE OF STRONGER CAPPED REGION. THESE STORMS WILL UNDOUBTEDLY BE ELEVATED WITH INFLOW PARCEL LAYER LIKELY ABOVE 850MB. STEEP LAPSE RATE ENVIRONMENT MAY ENHANCE GUSTY WIND POTENTIAL DESPITE THE DEEP STABLE BOUNDARY LAYER. MODELS ARE IN GENERAL AGREEMENT THAT THIS ACTIVITY MAY LINGER THROUGH THE MORNING WITH POSSIBLE REGENERATION AS WARM SECTOR HEATS ACROSS IA. SWD EXTENT OF THIS CONVECTION IS SOMEWHAT QUESTIONABLE AS VERY HIGH THICKNESS VALUES WILL BE NOTED...RESULTING IN EXTREME SFC TEMPERATURES NECESSARY FOR PARCELS TO FREELY CONVECT. UPSTREAM...LATE AFTERNOON THUNDERSTORMS SHOULD DEVELOP ALONG ADVANCING COLD FRONT ACROSS MN WHERE THERMODYNAMIC PROFILES WILL BE MUCH COOLER AND LESS INHIBITED. UPWARD EVOLUTION INTO AN MCS COULD OCCUR AS SPEED MAX DIGS INTO NWRN WI. ADDITIONALLY...LLJ SHOULD FOCUS INTO THIS REGION AFTER DARK ALLOWING COMPLEX TO PROPAGATE TOWARD LAKE SUPERIOR. ..DARROW.. 07/18/2006  From swody2 at goshenarc.org Tue Jul 18 06:11:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 02:11:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180609 SWODY2 SPC AC 180607 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES REGION... DOMINANT UPPER RIDGE WILL REMAIN ANCHORED OVER THE CNTRL PLAINS WHILE TRANSITORY SHORTWAVES RIPPLE EWD ALONG THE U.S./CANADIAN BORDER. ANOTHER SIGNIFICANT TROUGH...AND ASSOCIATED SPEED MAX...WILL APPROACH THE UPPER MS VALLEY/UPPER GREAT LAKES REGION DURING THE LATTER HALF OF THE PERIOD FORCING A SFC COLD FRONT INTO NWRN MN...TRAILING SWWD INTO ERN SD BY MID DAY. EARLY IN THE PERIOD...STRONG LOW LEVEL WARM ADVECTION AND A FOCUSED LLJ INTO SERN SD/SWRN MN WILL LIKELY ENHANCE MCS-TYPE CONVECTION ALONG ERN EDGE OF STRONGER CAPPED REGION. THESE STORMS WILL UNDOUBTEDLY BE ELEVATED WITH INFLOW PARCEL LAYER LIKELY ABOVE 850MB. STEEP LAPSE RATE ENVIRONMENT MAY ENHANCE GUSTY WIND POTENTIAL DESPITE THE DEEP STABLE BOUNDARY LAYER. MODELS ARE IN GENERAL AGREEMENT THAT THIS ACTIVITY MAY LINGER THROUGH THE MORNING WITH POSSIBLE REGENERATION AS WARM SECTOR HEATS ACROSS IA. SWD EXTENT OF THIS CONVECTION IS SOMEWHAT QUESTIONABLE AS VERY HIGH THICKNESS VALUES WILL BE NOTED...RESULTING IN EXTREME SFC TEMPERATURES NECESSARY FOR PARCELS TO FREELY CONVECT. UPSTREAM...LATE AFTERNOON THUNDERSTORMS SHOULD DEVELOP ALONG ADVANCING COLD FRONT ACROSS MN WHERE THERMODYNAMIC PROFILES WILL BE MUCH COOLER AND LESS INHIBITED. UPWARD EVOLUTION INTO AN MCS COULD OCCUR AS SPEED MAX DIGS INTO NWRN WI. ADDITIONALLY...LLJ SHOULD FOCUS INTO THIS REGION AFTER DARK ALLOWING COMPLEX TO PROPAGATE TOWARD LAKE SUPERIOR. ..DARROW.. 07/18/2006  From swody2 at goshenarc.org Tue Jul 18 17:25:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 13:25:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 181722 SWODY2 SPC AC 181721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY INTO THE UPR GREAT LAKES... ...SYNOPSIS... PROGRESSIVE UPPER FLOW PATTERN WITHIN THE STRONGER WESTERLIES ALOFT IS FORECAST TO CONTINUE ACROSS THE NRN TIER OF STATES TOMORROW AS UPPER RIDGE REMAINS ANCHORED ACROSS THE CENTRAL PARTS OF THE PLAINS AND ROCKIES. PRIMARY SHORT WAVE TROUGH CURRENTLY MOVING ACROSS SRN ALBERTA AND SRN BRITISH COLUMBIA IS EXPECTED TO PROGRESS ESEWD REACHING THE UPPER MS VALLEY/UPPER GREAT LAKES BY THE END OF THE PERIOD. ASSOCIATED NE/SW SURFACE COLD FRONT WILL MOVE EWD ACROSS THE NRN PLAINS AND UPPER MS VALLEY...REACHING A WRN LAKE SUPERIOR/SWRN MN/NRN NEB LINE BY 20/00Z...AND CONTINUING TO ERN LAKE SUPERIOR/SWRN WI/SWRN IA BY THE END OF THE PERIOD. A WARM FRONT WILL LIFT RAPIDLY NWD ACROSS THE UPPER MS VALLEY DURING THE MORNING WITH A VERY MOIST WARM SECTOR DEVELOPING BY AFTERNOON. ...NRN PLAINS/UPPER MS VALLEY INTO THE UPPER GREAT LAKES... THERMODYNAMIC ENVIRONMENT WILL BE INCREASINGLY FAVORABLE FOR STRONG/SEVERE CONVECTION AS LOW LEVEL MOISTURE RETURNS NWD BENEATH PRE-EXISTING PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE ELEVATED MIXED LAYER FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY. ELEVATED THUNDERSTORMS MAY BE OCCURRING IN THE MORNING ACROSS PARTS OF THE DAKOTAS WITH STRONGER STORMS CAPABLE OF PRODUCING ISOLATED HAIL AND STRONG WIND GUSTS. PRIMARY SEVERE THREAT IS EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING AS THE ELEVATED CONVECTION SPREADS EWD TOWARD THE FRONTAL ZONE WITH POTENTIAL TO BECOME ROOTED IN THE BOUNDARY LAYER...AND ADDITIONAL STORMS ARE LIKELY TO DEVELOP ALONG/JUST AHEAD OF THE FRONT AS LOW LEVEL CONVERGENCE AND STRONG HEATING LOCALLY WEAKENS THE CAP. ENVIRONMENT IS FORECAST TO BECOME VERY UNSTABLE NEAR THE FRONT AS SURFACE TEMPERATURES WARM INTO THE 90S AND DEW POINTS INCREASE INTO THE 70S...CONTRIBUTING TO MLCAPE OF 2500-4000 J/KG. VERTICAL SHEAR IS ALSO EXPECTED TO STRENGTHEN AS FORECAST SOUNDINGS EXHIBIT WIND PROFILES THAT VEER AND INCREASE WITH HEIGHT...IN RESPONSE TO A 50-60 KT MID LEVEL JET STREAK MOVING ACROSS ND INTO MN ON THE SOUTH SIDE OF THE SHORT WAVE TROUGH. COMBINATION OF STRONG INSTABILITY AND MODERATE DEEP LAYER SHEAR INDICATES POTENTIAL FOR A FEW SUPERCELLS TO DEVELOP...PRIMARILY FROM ERN SD INTO CENTRAL/SRN MN DURING THE AFTERNOON SPREADING EWD INTO PARTS OF WI AT NIGHT. STEEP LAPSE RATES/LARGE INSTABILITY AND A FAVORABLY SHEARED ENVIRONMENT SUGGEST STRONGER STORMS WILL BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WIND GUSTS...AND A FEW TORNADOES. THE TORNADO THREAT WILL BE ENHANCED IF DISCRETE CELLS CAN BE MAINTAINED INTO THE EVENING HOURS. CONVECTION IS EXPECTED TO GROW UPSCALE INTO ONE OR MORE MCS/S DURING THE OVERNIGHT HOURS WITH SEVERE THREAT CONTINUING AFTER DARK TOWARD THE UPPER GREAT LAKES. UNCERTAINTY IN CONVECTIVE MODE PRECLUDES INTRODUCTION OF A HIGHER RISK CATEGORY ATTM BUT REGION WILL BE MONITORED FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ...ERN NC INTO SERN VA... TROPICAL DEPRESSION OFF THE NC COAST IS FORECAST TO TURN NWWD TOWARD THE NC OUTER BANKS TOMORROW /SEE LATEST FORECASTS FROM TPC/. THIS MOTION WILL PLACE REGION OF STRONGER CYCLONIC LOW LEVEL FLOW/VERTICAL SHEAR INTO COASTAL SECTIONS OF NERN NC/SERN VA BEGINNING LATER TOMORROW AFTERNOON. THIS SUGGESTS INCREASING POTENTIAL FOR STRONGER CONVECTION ACROSS THIS AREA...ALTHOUGH CURRENT TRACK FORECAST WILL KEEP FAVORED CLIMATOLOGICAL SECTOR FOR TROPICAL CYCLONE TORNADOES MAINLY OFFSHORE. ..WEISS.. 07/18/2006  From swody2 at goshenarc.org Wed Jul 19 05:41:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 19 Jul 2006 01:41:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190538 SWODY2 SPC AC 190537 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT WED JUL 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER GREAT LAKES AND OH/MID MS VALLEY REGION... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN AND CNTRL HIGH PLAINS... ...SYNOPSIS... DOMINANT HIGH PRESSURE WILL BE SUPPLANTED BY BROAD UPPER TROUGHING WITH SEVERAL DISTINCT SIGNIFICANT SHORTWAVE TROUGHS FROM THE NRN PLAINS TO THE OH VALLEY DURING THE NEXT FEW DAYS. THIS TRANSITION WILL LIKELY RESULT IN CONSIDERABLE AREAL COVERAGE OF DEEP CONVECTION ALONG THE LEADING EDGE OF ADVANCING FRONTAL ZONE. ...LOWER GREAT LAKES/OH VALLEY/MID MS VALLEY... MCS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD FROM LOWER MI INTO NERN IL...AN EXTENSION OF DAY1 COMPLEX THAT SHOULD SPREAD SEWD ACROSS THE UPPER GREAT LAKES. DAY2 CONVECTIVE EVOLUTION MAY BE SOMEWHAT MODULATED BY INTENSITY OF EARLY MORNING ACTIVITY. THERE IS A DISTINCT POSSIBILITY THAT AN ELONGATED SEVERE SQUALL LINE WILL PROPAGATE SEWD ACROSS THE OH VALLEY AHEAD OF WELL DEFINED UPPER TROUGH. STEEP LAPSE RATE PLUME AND MODERATE BOUNDARY LAYER INSTABILITY SHOULD ENHANCE THE POTENTIAL FOR DAMAGING WINDS AS THIS ACTIVITY SPREADS ACROSS IND/OH...NEWD INTO UPSTATE NY. CONVECTION WILL STRUGGLE TO SPREAD/DEVELOP SWWD INTO MO WHERE STRONG CAP AND LESS FAVORABLE THERMODYNAMIC PROFILES WILL PROVE HOSTILE TO BOUNDARY LAYER DEVELOPMENT...IN ADDITION TO NEGLIGIBLE INFLUENCE FROM UPPER TROUGH. ...NRN/CNTRL HIGH PLAINS... SECONDARY SPEED MAX/SHORTWAVE TROUGH WILL SUPPRESS UPPER RIDGE OVER THE HIGH PLAINS THURSDAY. THIS FEATURE WILL UNDOUBTEDLY AID VERTICAL ASCENT FROM ERN MT/WRN DAKOTAS...SWD INTO THE NEB PANHANDLE WHERE ELY COMPONENT TO BOUNDARY LAYER FLOW WILL ENHANCE UPSLOPE COMPONENT AND LOW LEVEL SHEAR. FORECAST SOUNDINGS FOR THIS REGION STRONGLY SUGGEST SUPERCELLS WILL DEVELOP BY MID AFTERNOON...INITIALLY ACROSS NRN AREAS...WITH SEWD MOVEMENT EXPECTED DURING THE OVERNIGHT HOURS. INCREASING LLJ INTO THIS ACTIVITY ALSO FAVORS ONE OR MORE MCS-TYPE COMPLEXES AS CONVECTION CONSOLIDATES AND BECOMES ELEVATED AFTER DARK OVER THE CNTRL PLAINS. ISOLATED TORNADOES SEEM POSSIBLE EARLY IN STORM EVOLUTION...THEN DAMAGING WINDS AND HAIL WITH THE LARGER CLUSTERS. ...SWRN U.S... PRECIPITABLE WATER VALUES REMAIN SEASONABLY HIGH ACROSS AZ INTO SRN CA...WITH VALUES WELL IN EXCESS OF 1 IN NEAR THE BORDER. LARGE SCALE FLOW REGIME HAS YET TO CHANGE AND THIS SHOULD RESULT IN ANOTHER CONVECTIVELY ACTIVE DAY ACROSS THIS REGION. SLIGHT RISK MAY NEED TO BE ADDED IN LATER OUTLOOKS TO ADDRESS THE POSSIBILITY FOR WWD PROPAGATING ORGANIZED THUNDERSTORMS ACROSS THE DESERTS. ..DARROW.. 07/19/2006  From swody2 at goshenarc.org Wed Jul 19 17:32:26 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 19 Jul 2006 13:32:26 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191728 SWODY2 SPC AC 191727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT WED JUL 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDDLE MS VALLEY ACROSS THE GREAT LAKES REGION... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SYNOPSIS... UPPER FLOW PATTERN IS FORECAST TO AMPLIFY TOMORROW AS LEAD SHORT WAVE TROUGH CURRENTLY ACROSS THE SRN CANADIAN PRAIRIE PROVINCES/FAR NRN PLAINS PROGRESSES EWD ACROSS ERN CANADA...WHILE UPSTREAM SHORT WAVE TROUGH NEARING THE BRITISH COLUMBIA COAST IS PREDICTED TO DIG SEWD OVER THE NRN PLAINS IN RESPONSE TO BUILDING RIDGE OVER THE NRN INTERMOUNTAIN REGION. SURFACE COLD FRONT IS EXPECTED TO MOVE EWD/SEWD ACROSS THE GREAT LAKES AND CENTRAL PLAINS...REACHING A SERN QUEBEC/WRN PA/SRN INDIANA/SRN KS LINE BY THE END OF THE PERIOD. ...GREAT LAKES/OH VALLEY REGION... A BAND OF STRONG/LOCALLY SEVERE CONVECTION ALONG/AHEAD OF THE COLD FRONT MAY BE OCCURRING EARLY IN THE PERIOD FROM LAKE HURON/LOWER MI SWWD INTO NRN/CENTRAL IL AS DAY 1 OVERNIGHT MCS CONTINUES INTO THE DAY 2 PERIOD. AMPLE LOW LEVEL MOISTURE WITH SURFACE DEW POINTS GENERALLY IN THE UPPER 60S/LOWER 70S (LOCALLY MID/UPPER 70S OVER THE MIDDLE MS VALLEY) WILL BE PRESENT AHEAD OF THE FRONT AND/OR ANY EFFECTIVE OUTFLOW BOUNDARIES. PLUME OF STEEPER MID LEVEL LAPSE RATES WILL EXTEND FROM THE MIDDLE MS VALLEY ENEWD INTO THE LOWER GREAT LAKES IN ADVANCE OF CONVECTIVE ACTIVITY. THIS WILL ENHANCE INSTABILITY IN REGIONS WHERE LIMITED CLOUD COVER AND STRONGER DIURNAL HEATING OCCUR...WITH AFTERNOON MLCAPE RANGING FROM 1000-1500 J/KG FROM THE ST LAWRENCE VALLEY INTO THE UPPER OH VALLEY TO 2500-4000 J/KG ACROSS THE MIDDLE MS VALLEY. PRIMARY MID/UPPER LEVEL JET WILL CURVE CYCLONICALLY FROM THE UPPER GREAT LAKES INTO THE ST LAWRENCE VALLEY...WITH A SECONDARY JET STREAM ARCING ANTI-CYCLONICALLY FROM THE UPPER MS VALLEY ACROSS THE LOWER OH/TN VALLEYS. THIS DIFFLUENT JET PATTERN WILL ENHANCE UPPER LEVEL DIVERGENCE ACROSS THE LOWER GREAT LAKES INTO THE OH VALLEY WITH RESULTANT INCREASE IN LARGE SCALE ASCENT ABOVE THE LOW LEVEL FRONTAL ZONE. THIS SHOULD SUPPORT ADDITIONAL BANDS OF THUNDERSTORMS BEGINNING IN THE AFTERNOON...WITH ACTIVITY SPREADING EWD/SEWD AHEAD OF THE FRONT. DEEP LAYER VERTICAL SHEAR OF 30-40 KT FROM THE LOWER LAKES INTO THE ST LAWRENCE VALLEY WILL SUPPORT ORGANIZED SEVERE CONVECTION /INCLUDING POSSIBILITY OF ISOLATED SUPERCELLS/ WITH PRIMARY THREAT FOR DAMAGING WIND GUSTS AND LARGE HAIL WITH STRONGER CELLS. THIS ACTIVITY IS LIKELY TO REMAIN ORGANIZED AND PERSIST THROUGH THE OVERNIGHT HOURS EVENTUALLY REACHING UPSTATE NY/NRN VT AFTER 06Z. ALTHOUGH VERTICAL SHEAR IS FORECAST TO BE WEAKER /20-30 KT IN THE LOWEST 6 KM/ FARTHER SOUTHWEST ACROSS THE MIDDLE MS/LOWER OH VALLEYS...LARGER VALUES OF MLCAPE WILL BE SUPPORTIVE OF SEVERE STORMS. WEAKER DYNAMIC FORCING OVER THIS REGION SUGGESTS STORMS WILL GRADUALLY DECREASE IN COVERAGE AND INTENSITY DURING THE 03-06Z PERIOD. ...NRN HIGH PLAINS INTO CENTRAL PLAINS... LOW LEVEL UPSLOPE FLOW IS FORECAST TO DEVELOP OVER THE CENTRAL/NRN HIGH PLAINS NORTH OF THE SURFACE FRONT...WHICH WILL RESULT IN AN AXIS OF HIGHER DEW POINTS SPREADING FROM NRN KS/SRN NEB NWWD INTO ERN PARTS OF WY/MT AND THE WRN PARTS OF THE DAKOTAS AND NEB. A STEEP LAPSE RATE ENVIRONMENT COUPLED WITH INCREASING LOW LEVEL MOISTURE WILL RESULT IN UNSTABLE CONDITIONS WITH MUCAPE RANGING FROM OF 1000-1500 J/KG OVER THE HIGH PLAINS TO 2000-3000 J/KG OVER SRN NEB/NRN KS. THUNDERSTORMS ARE EXPECTED TO INCREASE/INTENSIFY DURING THE AFTERNOON OVER THE NRN HIGH PLAINS AS THE NEXT SHORT WAVE TROUGH DIGS SEWD FROM MT TOWARD THE NRN/CENTRAL PLAINS. FORECAST SOUNDINGS EXHIBIT PRONOUNCED DIRECTIONAL/SPEED SHEAR WITH HEIGHT AS LOW LEVEL SELY WINDS VEER TO WESTERLY IN THE MIDDLE LEVELS...PROVIDING A FAVORABLE ENVIRONMENT FOR SEVERE STORMS INCLUDING A FEW SUPERCELLS. LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES WILL BE POSSIBLE WITH STRONGER CELLS DURING THE AFTERNOON AND EVENING. THE CONVECTION IS EXPECTED TO CONSOLIDATE INTO ONE OR MORE MCS/S FROM THE LATE EVENING THROUGH THE OVERNIGHT HOURS AS IT SPREADS SEWD INTO PARTS OF NEB AND POSSIBLY FAR NRN KS WHERE ELEVATED MOISTURE/INSTABILITY WILL BE PRESENT NORTH OF THE SURFACE FRONT. PRIMARY SEVERE THREAT IS EXPECTED TO GRADUALLY TRANSITION TO LARGE HAIL AND ISOLATED WIND DAMAGE AS LOW LEVEL WARM ADVECTION/CONVERGENCE ALONG AND NORTH OF THE FRONT STRENGTHENS IN RESPONSE TO THE DEVELOPING NOCTURNAL LOW LEVEL JET OVER THE PLAINS. ...LOWER MS VALLEY/GULF COAST... FORECAST SOUNDINGS ACROSS THIS REGION INDICATE VERY WARM/MOIST LOW LEVEL AIR MASS WILL PERSIST TOMORROW...WITH A STRONG DECREASE IN THETA-E PREDICTED ABOVE 850 MB. THE PRESENCE OF DRIER AIR ALOFT COUPLED WITH ANTICIPATED DEVELOPMENT OF STEEP LAPSE RATES IN THE LOWEST 1-2 KM SUGGEST POTENTIAL FOR A FEW WET MICROBURSTS TO DEVELOP DURING THE AFTERNOON AND EVENING. NELY MID LEVEL WINDS OF 15-25 KT MAY ALLOW MARGINALLY ORGANIZED CONVECTION TO PERSIST ACROSS THIS REGION...BUT OVERALL COVERAGE IS NOT EXPECTED TO WARRANT A SLIGHT RISK ATTM. ...AZ/EXTREME SERN CA... SYNOPTIC PATTERN THAT IS DOMINATED BY UPPER RIDGE FROM THE GREAT BASIN EWD INTO THE PLAINS WILL CONFINE STRONGER ELY COMPONENT OF THE DEEP LAYER FLOW ACROSS SRN PART OF AZ. PRESENCE OF A DEEP SURFACE-BASED WELL-MIXED LAYER AND SUFFICIENT MOISTURE WILL ALLOW THUNDERSTORMS TO DEVELOP OVER PARTS OF THE RIM AND MOUNTAINS OF EAST CENTRAL/SERN AZ...WITH ACTIVITY PROPAGATING PRIMARILY WWD ACROSS THE LOWER DESERTS TOWARD THE LOWER CO RIVER VALLEY. ALTHOUGH THERE IS TYPICAL UNCERTAINTY IN THE DETAILS OF CONVECTIVE EVOLUTION ACROSS THIS AREA...POTENTIAL WILL EXIST FOR A FEW WET MICROBURSTS TO DEVELOP. ..WEISS.. 07/19/2006  From swody2 at goshenarc.org Thu Jul 20 06:02:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 20 Jul 2006 02:02:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200559 SWODY2 SPC AC 200558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT THU JUL 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS TO MIDDLE TN... SECONDARY UPSTREAM SHORTWAVE TROUGH WILL DIG SEWD ACROSS THE NRN PLAINS INTO NEB BY THE BEGINNING OF THE DAY2 PERIOD. THIS FEATURE WILL BE RESPONSIBLE FOR ENHANCING LOW LEVEL WARM ADVECTION/ELEVATED THUNDERSTORM CLUSTERS THURSDAY NIGHT INTO FRIDAY MORNING ACROSS MUCH OF THE CNTRL PLAINS REGION. DAY2 SEVERE THREAT WILL BE SOMEWHAT MODULATED BY THE MAGNITUDE OF DAY1 CONVECTION OVER THE OH/MID MS VALLEY REGION AND ITS ABILITY TO FORCE SFC BOUNDARY SWD TO A POSITION ARCING FROM THE LOWER OH RIVER...IL/IND/KY...INTO SERN KS. IT APPEARS EARLY MORNING MCS OVER NEB/KS WILL PROPAGATE SEWD ALONG THE AFOREMENTIONED LOW LEVEL CONVERGENCE ZONE...AIDED BY PROGRESSIVE SHORTWAVE TROUGH. WHETHER THE EARLY MORNING ACTIVITY MAINTAINS ITS INTENSITY OR REDEVELOPS DURING THE HEAT OF THE DAY IS NOT COMPLETELY CLEAR AT THIS TIME. NWRN PORTIONS OF THE SLGT RISK ARE PREDICATED ON MCS MAINTAINING ITS STRUCTURE/INTENSITY THROUGH THE EARLY MORNING. STRONG DOWNSTREAM HEATING WILL AID INSTABILITY FOR ADDITIONAL DEVELOPMENT ACROSS MO/AR INTO KY/TN BY MID/LATE AFTERNOON. ALTHOUGH THIS CONVECTION WILL GRADUALLY MOVE AWAY FROM STRONGER MID-HIGH LEVEL FLOW...IT APPEARS SUFFICIENT LARGE SCALE FORCING WILL SPREAD INTO THIS REGION FOR RENEWED CONVECTIVE DEVELOPMENT AS UPPER TROUGH AXIS DIGS SEWD. STRONG WINDS ARE THE MOST LIKELY SEVERE THREAT WITH THIS ACTIVITY. ...NEW ENGLAND... TROPICAL STORM BERYL IS EXPECTED TO REMAIN OFF THE NEW ENGLAND COAST THROUGH THE PERIOD. THIS STORM TRACK SHOULD MINIMIZE LOW LEVEL CONVERGENCE/INSTABILITY ALONG THE IMMEDIATE COAST. HOWEVER...FARTHER INLAND BOUNDARY LAYER LAPSE RATES SHOULD STEEPEN ACROSS UPSTATE NY INTO VT AS SFC TEMPERATURES WARM AHEAD OF SFC FRONT. DEEP LAYER SHEAR WILL GRADUALLY INCREASE AS UPPER TROUGH APPROACHES. STRONGER STORMS THAT FORM WITHIN THIS ENVIRONMENT MAY PRODUCE GUSTY WINDS OR PERHAPS SOME HAIL. WILL HOLD OFF ON ADDING A SLIGHT RISK AT THIS TIME UNTIL INFLUENCE OF BERYL ON THERMODYNAMIC ENVIRONMENT IS MORE CLEAR. ..DARROW.. 07/20/2006  From swody2 at goshenarc.org Sat Jul 22 05:58:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 22 Jul 2006 01:58:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220555 SWODY2 SPC AC 220554 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT SAT JUL 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN CAROLINAS AND SERN VA... ...SYNOPSIS... THE UPPER IMPULSE EXPECTED TO REACH THE MID-ATLANTIC STATES SATURDAY WILL EJECT NEWD INTO SERN CANADA ON SUNDAY. THE PRIMARY LONGWAVE TROUGH WILL GRADUALLY LIFT NEWD AS WELL AS THE NEXT DISTURBANCE DIGS SEWD INTO THE UPPER GRTLKS/NWRN ONT. MEANWHILE...THE UPPER HIGH WILL CONTINUE OVER THE WRN STATES WITH A CENTER OVER THE ERN UT. IN THE LWR LEVELS...THE COLD FRONT SITUATED ALONG THE APPALACHIANS WWD INTO THE SRN HIGH PLAINS WILL STALL LATE SATURDAY AS IT BECOMES PARALLEL WITH THE SWLY FLOW ALOFT. A NEW FRONT WILL MOVE QUICKLY SEWD FROM THE CANADIAN PRAIRIES TO THE UPPER GRTLKS AND UPPER MS VLY BY 12Z MON. ...ERN CAROLINAS AND SERN VA... PRIMARY FORCING FOR ASCENT ASSOCIATED WITH THE LEAD MID-LEVEL IMPULSE WILL BEGIN TO PULL AWAY FROM THE MID-ATLANTIC REGION EARLY SUNDAY. BUT...THE FLOW WILL REMAIN CYCLONIC ALOFT FOR THE MAJORITY OF THE AFTN FROM SC NWD AS THE PRIMARY LONGWAVE TROUGH LAGS. THERE WILL LIKELY BE BANDS OF CONVECTION ALONG/AHEAD OF THE FRONT THAT MAY WEAKEN/SHIFT EWD BY AFTN. IF SUFFICIENT INSOLATION CAN BE REALIZED IN WAKE OF THIS PCPN...TSTMS COULD DEVELOP OVER THE MOUNTAINS OF NC/SC DURING PEAK HEATING. HIGH PRECIPITABLE WATER VALUES AND MODEST MID-LEVEL WLY FLOW OF 30-35 KTS WILL BE FAVORABLE FOR A FEW ORGANIZED STORMS. DAMAGING WINDS WILL BE THE PRIMARY THREAT. ACTIVITY SHOULD SHIFT TOWARD THE COAST OVERNIGHT AND LIKELY WEAKEN AFTER SUNSET. ...SERN STATES/GULF COASTAL REGION... AIR MASS ALONG/S OF THE SYNOPTIC FRONT WILL REMAIN QUITE MOIST AND UNSTABLE SUNDAY AFTN/EVE. AMBIENT FLOW WILL BE WEAK AND MID-LEVEL LAPSE RATES WILL BE POOR OWING TO WARM TROPOSPHERE. WEAK CINH AND LOCALIZED CONVERGENCE/HEATING...HOWEVER...WILL BE FAVORABLE FOR TSTMS. ISOLD TSTMS MAY PRODUCE A DAMAGING WIND GUST...BUT WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. ...UPPER GRTLKS...NRN MN AND NERN ND... NEXT IN A SERIES OF UPPER DISTURBANCES WILL TRANSLATE QUICKLY SEWD WITHIN NWLY FLOW REGIME TO NWRN ONT/UPPER GRTLKS REGION BY LATE SUNDAY. A PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL STREAM EWD AHEAD OF THE FRONT ATOP SFC DEW POINTS IN THE LWR-MID 60S. THIS WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR TSTMS ALONG/AHEAD OF THE FRONT. INCREASING WNWLY UNIDIRECTIONAL FLOW REGIME WILL BE FAVORABLE FOR FAST MOVING TSTM LINE SEGMENTS THAT COULD GIVE ISOLD DAMAGING WIND GUSTS. ...SRN PLATEAU/FOUR CORNERS REGION... JETSTREAK WITHIN THE SUBTROPICAL JET ROUNDING THE PERIPHERY OF THE UPPER HIGH...WILL MOVE FROM CO THROUGH NM INTO AZ SUN AFTN/NIGHT. TSTMS WILL DEVELOP OVER THE HIGHER TERRAIN AND LIKELY BE ENHANCED BY THE DISTURBANCE. STORMS WILL PROPAGATE SWWD WITHIN THE 30-40 KT MID-LEVEL FLOW REGIME WITH THE RISK OF ISOLD SEVERE WIND GUSTS. STORMS THAT DEVELOP OVER THE MOGOLLON RIM COULD MOVE INTO THE LWR DESERTS BY EVENING BEFORE WEAKENING. ..RACY.. 07/22/2006  From swody2 at goshenarc.org Sat Jul 22 17:07:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 22 Jul 2006 13:07:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221703 SWODY2 SPC AC 221702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 PM CDT SAT JUL 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CHESAPEAKE BAY INTO PARTS OF THE CAROLINAS... ...SYNOPSIS... ERN U.S. TROUGH IS FORECAST TO WEAKEN AS IT LIFTS NEWD IN RESPONSE TO APPROACH OF UPSTREAM SHORT WAVE TROUGH MOVING THROUGH ONTARIO. IN THE W...SOME FLATTENING OF RIDGE WILL OCCUR ACROSS THE PACIFIC NW INTO NRN ROCKIES WITH MID-LEVEL HIGH REMAINING ANCHORED OVER THE GREAT BASIN. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH WEAKENING TROUGH WILL DEVELOP NEWD FROM ME INTO THE CANADIAN MARITIMES WITH TRAILING COLD FRONT PUSHING OFF THE NEW ENGLAND AND MIDDLE ATLANTIC COASTS. FARTHER TO THE S...FRONT WILL BE SLOWER TO PUSH EWD FROM CHESAPEAKE BAY SWD THROUGH THE PIEDMONT AND COASTAL PLAIN. A SECONDARY COLD FRONT WILL PUSH SWD INTO THE N-CNTRL TIER OF STATES IN ASSOCIATION WITH ONTARIO IMPULSE. ...CHESAPEAKE BAY INTO THE CAROLINAS... AS MENTIONED ABOVE...SURFACE FRONT WILL BE SLOW TO SHIFT EWD THROUGH THE PERIOD OWING TO WEAKENING LARGE-SCALE FORCING AND INCREASINGLY PARALLEL ORIENTATION OF BOUNDARY TO MID AND UPPER-LEVEL FLOW FIELDS. PRE-FRONTAL AIR MASS WILL REMAIN QUITE MOIST WITH DEWPOINTS IN THE UPPER 60S TO LOW/MID 70S...AND WHEN COUPLED WITH DIABATIC HEATING...BOUNDARY LAYER WILL BECOME MODERATELY UNSTABLE BY AFTERNOON WITH MLCAPES OF 1000-2500 J/KG. NEUTRAL TO SLIGHT HEIGHT RISES DURING TIME OF PEAK HEATING WOULD SUGGEST THAT LARGE-SCALE FORCING WILL REMAIN QUITE NEGLIGIBLE...AND THAT TSTM DEVELOPMENT WILL LIKELY BE DRIVEN BY A WEAK CAP AND LOW-LEVEL CONVERGENCE ALONG FRONTAL ZONE. DESPITE NEAR MOIST ADIABATIC MID-LEVEL LAPSE RATES...THE PRESENCE OF MODESTLY STRONG /30-35 KT/ MID-LEVEL FLOW...THE MODERATE INSTABILITY AND RELATIVELY STEEP LOW-LEVEL LAPSE RATES...SCATTERED SEVERE STORMS WILL BE POSSIBLE WITH THE PRIMARY SEVERE WEATHER THREAT BEING LOCALLY DAMAGING WINDS. STORMS SHOULD TEND TO WEAKEN BY MID TO LATE EVENING AS BOUNDARY LAYER SLOWLY STABILIZES. ...UPPER MS VALLEY INTO NRN HIGH PLAINS... BOUNDARY LAYER MOISTURE WILL REMAIN QUITE LIMITED AHEAD OF COLD FRONT MOVING SWD OUT OF CANADA WITH DEWPOINTS IN THE 40S TO PERHAPS LOW/MID 50S. HOWEVER...FORECAST SOUNDINGS INDICATE THE PRESENCE OF RELATIVELY STEEP LOW TO MID-LEVEL LAPSE RATES WHICH WILL LARGELY CONTRIBUTE TO MLCAPES OF 500-1000 J/KG. STORMS WILL LIKELY DEVELOP NEAR OR JUST N OF THE INTERNATIONAL BORDER DURING THE LATE AFTERNOON OR EARLY EVENING HOURS ALONG OR SLIGHTLY BEHIND SURFACE FRONT. ACTIVITY SHOULD THEN MOVE/DEVELOP SWD INTO NRN MN...ND AND MT SUNDAY EVENING AND NIGHT WITH A THREAT OF ISOLATED SEVERE HAIL AND GUSTY WINDS. ...SRN ROCKIES INTO AZ DESERTS... ERN PERIPHERY OF WRN U.S. HIGH IS FORECAST TO BE CONVECTIVELY ACTIVE SUNDAY AFTERNOON AND EVENING OWING STRONG HEATING ALONG THE ELEVATED TERRAIN AND THE SUBTLE INFLUENCE OF WEAK IMPULSES EMBEDDED IN LARGER-SCALE CIRCULATION. STRONG BOUNDARY LAYER HEATING/MIXING WILL RESULT IN A DEEP SUB-CLOUD LAYER WITH SBCAPES INCREASING TO 500-800 J/KG...WHICH WILL BE SUPPORTIVE OF ISOLATED SEVERE STORMS CAPABLE OF LOCALLY DAMAGING WINDS. A POTENTIALLY GREATER THREAT OF MORE ORGANIZED STORMS CAPABLE OF DAMAGING WINDS WILL EXIST FROM ERN AZ INTO THE LOWER DESERTS WHERE DEEPER 20-30 KT NELY/ELY SHEAR WILL FAVOR COLD POOL ORGANIZATION WITH ANY STORM CLUSTERS MOVING OFF THE MOGOLLON RIM. ..MEAD.. 07/22/2006  From swody2 at goshenarc.org Sun Jul 23 05:57:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 23 Jul 2006 01:57:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230554 SWODY2 SPC AC 230553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT SUN JUL 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY AND CNTRL GRTLKS REGION... ...SYNOPSIS... A GRADUAL TREND TOWARD A MORE ZONAL FLOW REGIME WILL OCCUR ON MON AS THE UPPER HIGH OVER THE WRN STATES BUILDS EWD AND THE NERN TROUGH BEGINS TO FILL. A STRONG SHORTWAVE TROUGH THAT WILL MOVE INTO NWRN ONT EARLY MON WILL TRANSLATE TO SRN QUE BY 12Z TUE. A SEPARATE BUT WEAKER JET STREAM WILL CARRY OTHER DISTURBANCES SEWD FROM THE DAKS INTO THE UPPER MS VLY AND UPPER MIDWEST...ALONG NRN PERIPHERY OF THE UPPER HIGH. ...UPPER MS VLY TO THE CNTRL GRTLKS REGION... A COLD FRONT ASSOCIATED WITH THE CANADIAN SHORTWAVE TROUGH WILL MOVE SEWD THROUGH THE CNTRL GRTLKS...UPPER MS VLY AND NRN PLAINS THROUGH MON AFTN. A WARM FRONT WILL GRADUALLY SHIFT NEWD THROUGH THE CNTRL GRTLKS. MORNING ELEVATED CONVECTION WILL LIKELY BE ONGOING ACROSS PARTS OF THE CNTRL GRTLKS AS THE WARM/MOIST AIR MASS RETURNS EWD ACROSS THE REGION. THIS PLACES SOME UNCERTAINTY ON THE MAGNITUDE OF PRE-FRONTAL HEATING/DESTABILIZATION LATER ON MON. BUT...A WLY FLOW REGIME ALOFT WILL ADVECT STEEP MID-LEVEL LAPSE RATES EWD FROM THE PLAINS AND LIKELY CONTRIBUTE TO THE POTENTIAL INSTABILITY. IF ENOUGH HEATING CAN BE REALIZED...SFC-BASED CONVECTION MAY EVOLVE DURING THE AFTN ALONG/AHEAD OF THE FRONT FROM PARTS OF ERN UPPER/NRN-CNTRL LWR MI WWD INTO WI AND ECNTRL MN. STRONGER TSTMS ARE EXPECTED ALONG THE WRN/SRN PARTS OF THE FRONT WHERE MID-LEVEL LAPSE RATES WILL BE STEEPER. VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG...BUT THE UNIDIRECTIONAL NATURE OF THE WNWLY FLOW WILL BE FAVORABLE FOR DAMAGING WIND GUSTS ALONG WITH LARGE HAIL. ISOLD TORNADOES MAY BE POSSIBLE ACROSS PORTIONS OF MI VCNTY THE WARM FRONT WHERE THE BOUNDARY LAYER WINDS FLOW WILL BE MOVE SLY BENEATH WLY FLOW ALOFT. ...CNTRL PLAINS... ELEVATED MIXED LAYER WILL BECOME STRONGER THROUGH MON ACROSS THE PLAINS AS THE UPPER RIDGE BUILDS EWD. BUT...THE BOUNDARY LAYER IS EXPECTED TO HEAT CONSIDERABLY VCNTY A LEE-TROUGH THAT WILL MOVE INTO PARTS OF SCNTRL SD AND NCNTRL NEB MON AFTN/EVE. LOCALIZED CONVERGENCE AND HEATING MAY CONTRIBUTE TO ISOLD HIGH-BASED TSTM DEVELOPMENT VCNTY THIS TROUGH. VERTICAL SHEAR WILL BE SOMEWHAT WEAK...ON THE ORDER OF 30-35 KTS. BUT...COUPLED WITH THE VERY STEEP LAPSE RATE ENVIRONMENT...ISOLD SUPERCELLS MAY BE POSSIBLE GIVING MAINLY LARGE HAIL AND PERHAPS A DAMAGING WIND GUST. ACTIVITY MAY CONGEAL INTO A WEAKLY ORGANIZED MCS OVERNIGHT MON AS THE LLJ INCREASES ACROSS THE PLAINS. THIS ACTIVITY MAY POSE A HAIL RISK. ...SRN PLATEAU/DESERT SW... ANOTHER ROUND OF DIURNAL TSTMS ARE EXPECTED ACROSS THE HIGHER TERRAIN OF THE SRN PLATEAU/DESERT SW MONDAY AFTN/EVE. MID-LEVEL FLOW SHOULD BEGIN TO SLACKEN OWING TO STRENGTHENING UPPER RIDGE AXIS. BUT...STEEP LOW-LEVEL LAPSE RATES WILL ENCOURAGE GUSTY WINDS/ISOLD SEVERE WIND GUSTS WITH THE STRONGER STORMS. ..RACY.. 07/23/2006  From swody2 at goshenarc.org Sun Jul 23 17:26:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 23 Jul 2006 13:26:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231722 SWODY2 SPC AC 231721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SUN JUL 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE UPPER GREAT LAKES WWD INTO ERN SD... ...SYNOPSIS... FLATTENING OF SWRN U.S. RIDGE IS FORECAST DURING THE DAY TWO PERIOD OWING TO THE TRANSLATION OF WEAK IMPULSES FROM THE PACIFIC NW AND NRN ROCKIES INTO THE NRN PLAINS. IN THE NE...HEIGHTS WILL REBOUND IN WAKE OF SHORT WAVE TROUGH LIFTING NEWD INTO THE CANADIAN MARITIMES. IN THE LOW-LEVELS...A COLD FRONT ASSOCIATED WITH A SHORT WAVE TROUGH MOVING THROUGH ONTARIO WILL PUSH SEWD INTO THE UPPER GREAT LAKES WITH THIS BOUNDARY EXTENDING WWD TO DEVELOPING LOW PRESSURE OVER SD. MEANWHILE IN THE SE...REMNANT BOUNDARY FROM THE NC COAST INTO THE NWRN GULF OF MEXICO WILL WEAKEN THROUGH THE PERIOD. ...UPPER GREAT LAKES INTO NRN PLAINS... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING MONDAY MORNING OVER PARTS OF WI INTO THE UP MI WITHIN LOW-LEVEL WAA REGIME ASSOCIATED WITH SHORT WAVE TROUGH MOVING THROUGH ONTARIO. WHILE SOME HAIL WILL BE POSSIBLE WITH THESE STORMS THROUGH THE MORNING HOURS...THIS ACTIVITY SHOULD GENERALLY MOVE EWD INTO SWRN ONTARIO BY AFTERNOON. ADDITIONAL...DIURNAL STORM DEVELOPMENT WILL BE POSSIBLE BY AFTERNOON ALONG COLD FRONT PUSHING SEWD INTO REGION FROM LOWER MI WWD THROUGH WI...CNTRL/SRN MN AND ERN SD. LATEST MODEL GUIDANCE SUGGESTS THAT MODEST BOUNDARY LAYER MOISTURE /DEWPOINTS OF 55-65 F...DECREASING TO GENERALLY 50S WWD OVER SD/ COUPLED WITH STEEP LOW TO MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO MODERATE INSTABILITY BY AFTERNOON WITH MLCAPES OF 1000-2000 J/KG. THE STRONGEST VERTICAL SHEAR IS FORECAST TO EXIST IN CLOSER PROXIMITY TO ONTARIO IMPULSE N OF THE INTERNATIONAL BORDER...AND TO THE W OVER WRN/CNTRL SD WITH GENERALLY 25-35 KTS OF DEEP-LAYER SHEAR EXPECTED ACROSS SLIGHT RISK PORTION OF FRONTAL ZONE. SURFACE-BASED TSTMS WILL BECOME INCREASINGLY LIKELY BY AFTERNOON ALONG FRONT OWING TO GLANCING INFLUENCE OF ONTARIO SHORT WAVE TROUGH AND INCREASED LARGE-SCALE FORCING ASSOCIATED WITH WEAKER UPSTREAM IMPULSE MOVING THROUGH THE NRN PLAINS. STORMS SHOULD REMAIN LARGELY MULTICELLULAR FROM LOWER MI WWD INTO MN WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS. DESPITE WEAKENING INSTABILITY WITH WWD EXTENT INTO SD...POTENTIAL WILL EXIST FOR A COUPLE OF HIGH-BASED MARGINAL SUPERCELLS...SUPPORTED BY THE STEEP LAPSE RATES AND AROUND 35 KTS OF DEEP-LAYER SHEAR. THESE STORMS WILL ALSO BE CAPABLE OF LOCALLY HIGH WINDS AND HAIL. ...NRN HIGH PLAINS... A FEW HIGH-BASED STRONG TO MARGINALLY SEVERE STORMS WILL BE POSSIBLE MONDAY AFTERNOON AND EVENING ALONG WRN EXTENSION OF FRONTAL BOUNDARY OVER MT. LOW-LEVEL MOISTURE WILL REMAIN LIMITED...THOUGH THE PRESENCE OF STEEP LAPSE RATES WILL SUPPORT MARGINAL INSTABILITY. FORECAST SOUNDINGS INDICATE THAT VERTICAL SHEAR WILL BE SUFFICIENT FOR SOME STORM ORGANIZATION WITH A THREAT OF ISOLATED STRONG WINDS/SEVERE HAIL. ...CNTRL ROCKIES TOWARD THE LOWER CO VALLEY... DIURNAL TSTMS ARE EXPECTED TO DEVELOP ALONG THE HIGHER TERRAIN AROUND PERIPHERY OF FLATTENING MID-LEVEL RIDGE MONDAY AFTERNOON AND EVENING. A SHORT WAVE TROUGH MOVING SWD THROUGH CO WILL LIKELY FOCUS A MORE CONCENTRATED CLUSTER OF STORMS FROM S-CNTRL CO INTO CNTRL NM...WITH MORE WIDELY SCATTERED DEVELOPMENT ANTICIPATED ALONG OROGRAPHICALLY FAVORED AREAS. DEEP BOUNDARY LAYER MIXING WILL RESULT IN THE DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND STRONG EVAPORATIONAL COOLING POTENTIAL IN THE SUB-CLOUD LAYER WITH LOCALLY DAMAGING WINDS POSSIBLE WITH THE STRONGEST STORMS. ...SRN ATLANTIC COAST... RICH BOUNDARY LAYER MOISTURE COUPLED WITH DAYTIME HEATING ARE EXPECTED TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS MONDAY TO THE S OF WEAKENING FRONTAL ZONE WITH MLCAPES INCREASING TO 1500-2500 J/KG. LITTLE OR NO CONVECTIVE INHIBITION SHOULD ALLOW TSTMS TO BECOME FAIRLY WIDESPREAD ACROSS THE REGION BY PEAK HEATING WITH THE POTENTIAL FOR ISOLATED...SEVERE WET MICROBURSTS. ..MEAD.. 07/23/2006  From swody2 at goshenarc.org Mon Jul 24 06:06:55 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 24 Jul 2006 02:06:55 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240603 SWODY2 SPC AC 240603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0103 AM CDT MON JUL 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NRN NEW ENGLAND... ...SYNOPSIS... THE WRN STATES UPPER RIDGE WILL EXPAND TO THE N AND E ACROSS THE SRN AND CNTRL PARTS OF THE COUNTRY ON TUE AS THE PRIMARY BELT OF WLYS BECOMES SITUATED ALONG THE INTERNATIONAL BORDER. A MID-LEVEL SHORTWAVE TROUGH THAT WILL REACH SRN QUE BY EARLY TUE WILL EJECT NEWD INTO ATLANTIC CANADA BY TUE EVE...SKIRTING PARTS OF NRN NEW ENGLAND. MEANWHILE...A SECONDARY DISTURBANCE WILL MOVE QUICKLY SEWD THROUGH THE NRN PLAINS TO THE UPPER MS VLY DURING THE DAY TUE. ...NRN NEW ENGLAND... THE SRN QUE H5 SHORTWAVE TROUGH WILL GLANCE ACROSS NRN NEW ENGLAND DURING TUE AFTN WITH ASSOCIATED 40-50 KT JET...BOOSTING VERTICAL SHEAR VALUES. AIR MASS SHOULD GRADUALLY MOISTEN...BUT RECENT INTRUSION OF A CP AIR MASS WILL LIKELY SLOW THE RETURN OF QUALITY MOISTURE. THIS...AND THE FACT THAT MID-TROPOSPHERIC LAPSE RATES WILL GENERALLY BE BELOW 6 DEG C PER KM...SUGGEST THAT INSTABILITY WILL BE MODEST AT BEST. BUT...GIVEN MAGNITUDE OF ASCENT AND SHEAR IN PLACE DURING PEAK HEATING...A FEW TSTMS WILL LIKELY PRODUCE DAMAGING WIND GUSTS...PRIMARY OVER NRN MAINE. ...SWRN DESERTS... EMILIA IS EXPECTED TO BECOME A HRCN AND MOVE JUST OFF THE WRN BAJA COAST THROUGH TUE. CLIMATOLOGICALLY...SIGNIFICANT GULF OF CA SURGES OCCUR WHEN A TROPICAL SYSTEM TAKES A PATH SIMILAR TO EMILIA. THIS WILL LIKELY CAUSE AN DRAMATIC INCREASE IN BOUNDARY LAYER MOISTURE ACROSS THE LWR DESERT REGIONS BY TUE AFTN/EVE AND COULD PLAY A ROLE IN AN INCREASE IN TSTMS PROBABILITIES. MODELS SUGGEST THAT NELY FLOW WILL INCREASE TO AOA 30 KTS AS THE BOUNDARY LAYER FLOW REMAINS UPSLOPE DURING PEAK HEATING. AS A RESULT...TSTMS COULD STRONGLY PROPAGATE INTO THE LWR DESERTS DURING THE AFTN/EVE WITH DAMAGING WINDS AND HAIL. TYPICALLY... MESOSCALE PROCESSES...WHICH ARE DIFFICULT TO PIN-POINT THIS FAR IN ADVANCE ACROSS THE SWRN STATES...DICTATE STORM MODE AND EVOLUTION. AS SUCH...A CATEGORICAL SLGT RISK IS NOT WARRANTED ATTM. BUT... THE REGION MAY NEED HIGHER SEVERE PROBABILITIES IN FUTURE OTLKS. ...UPPER MS VLY/CORN BELT... DIFFICULT FORECAST CONTINUES WITH RESPECT TO SEVERE TSTM PROBABILITIES ACROSS THE REGION. PRIMARY FORCING FOR ASCENT WILL BE PULLING NEWD AWAY FROM THE REGION EARLY ON TUE AS THE STRONGER SHORTWAVE TROUGH MOVES TO SERN CANADA. THE LOW-LEVEL FLOW...HOWEVER...SHOULD REMAIN SWLY...MAXIMIZING WARM ADVECTION REGIME DOWNSTREAM FROM STRONGER ELEVATED MIXED LAYER ACROSS THE MO VLY. AS A RESULT...CONVECTION/TSTMS WILL LIKELY DEVELOP THROUGHOUT THE DAY FROM PARTS OF IA/SRN WI EWD TOWARD MI...OR WITHIN/NE OF THE STRONGER LOW-LEVEL THERMAL AXIS. VERTICAL SHEAR WILL REMAIN WEAK AND SUGGESTS THAT THE SEVERE PROBABILITIES WILL REMAIN LOW...ESPECIALLY IF SFC RIDGING BECOMES AS STRONG AS THE 00Z NAM SUGGESTS. FARTHER NW...A SEPARATE REGION OF SLIGHTLY HIGHER SEVERE PROBABILITIES WILL EXIST ACROSS NRN/CNTRL MN TOWARD THE UPPER GRTLKS. THIS REGION WILL BE DOWNSTREAM FROM A WEAK IMPULSE. 00Z MODEL SUITE DIFFER IN MAGNITUDE OF THIS WAVE. GIVEN THAT THE NAM IS AN OUTLIER...HAVE GIVEN CREDENCE TO THE GFS/ECMWF IN A WEAKER WAVE. TSTMS WILL STILL REMAIN POSSIBLE...ALONG/AHEAD OF THE ASSOCIATED COLD FRONT...BUT RELATIVELY WARMER MID-LEVEL TEMPERATURES MAY TEND TO BE DETRIMENTAL TO WIDESPREAD TSTM INITIATION. GIVEN A SUSTAINED STORM...THE MAGNITUDE OF LAPSE RATES AND AT LEAST MODEST VERTICAL SHEAR WILL BE FAVORABLE FOR ISOLD LARGE HAIL. ...CNTRL PLAINS... HIGH-BASED TSTMS WILL LIKELY DEVELOP TUE AFTN/EVE ALONG/AHEAD OF A LEE-TROUGH FROM ERN CO NEWD INTO NCNTRL NEB. THIS REGION WILL RESIDE ALONG THE SRN PERIPHERY OF THE UPPER MS VLY IMPULSE WITH MODEST NWLY FLOW ALOFT. GIVEN THE SLY LOW-LEVEL FLOW...SUFFICIENT DIRECTIONAL SHEAR MAY EXIST FOR ISOLD ORGANIZED STORMS THAT PRODUCE LARGE HAIL/DAMAGING WIND GUSTS. ACTIVITY MAY DEVELOP INTO A LOOSELY ORGANIZED MCS THAT WILL MOVE EWD INTO THE CORN BELT OVERNIGHT TUE. ...SERN TX... TROPICAL AIR MASS WILL CONTINUE TO FLOW NWD ALONG ERN SIDES OF THE UPPER LOW EXPECTED TO MIGRATE NWD INTO THE REGION ON TUE. RESIDUAL FRONT AND DEEPENING SFC LOW WILL MAINTAIN AN ESELY BOUNDARY LAYER FLOW. AS A RESULT...TSTMS THAT DEVELOP AND MOVE NWD MAY PRODUCE ISOLD TORNADOES...ESPECIALLY AS THEY APPROACH THE OLD FRONT ACROSS PORTIONS OF SERN TX. ..RACY.. 07/24/2006  From swody2 at goshenarc.org Mon Jul 24 17:17:15 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 24 Jul 2006 13:17:15 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241712 SWODY2 SPC AC 241711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1211 PM CDT MON JUL 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS DURING THE AFTERNOON OVER EXTREME NRN MAINE.... ...SYNOPSIS... MID/UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE SOUTHWEST QUARTER OF THE U.S. FIRST MID/UPPER LEVEL SHORTWAVE TROUGH NOW OVER ONTARIO IS FORECAST TO MOVE EWD INTO QUEBEC THEN LIFT NNEWD SKIRTING WRN AND NRN EDGES OF MAINE TUESDAY AFTERNOON. SECOND SHORTWAVE TROUGH NOW OVER WRN SASKATCHEWAN IS EXPECTED TO MOVE ACROSS THE NRN PLAINS AND UPPER MIDWEST DURING THE SECOND HALF OF THE PERIOD. FINALLY...MID/UPPER LEVEL TROUGH OVER NERN SECTIONS OF MEXICO IS PROGGED TO INTENSIFY SLIGHTLY AND BECOME A CLOSED LOW OVER SOUTH CENTRAL TEXAS BY THE END OF THE PERIOD. ...NRN PARTS OF MAINE... ANALYSIS OF NAM...GFS AND NMM-WRF MODELS REVEAL MORE NEGATIVES THAN POSITIVES FOR SEVERE POTENTIAL ACROSS THIS AREA. THE SHORT RANGE ENSEMBLE SEEMS TO BE THE SOLUTION THAT IS A LITTLE MORE AGGRESSIVE DETAILING A 30 PERCENT PROBABILITY FOR SUPERCELLS AS IT BANKS ON THE FAVORABLE SHEAR PROFILES IN THE FORECAST SOUNDINGS. GIVEN THAT THE INDIVIDUAL MODELS ARE TAKING THE SHORTWAVE TROUGH INTO THE ST. LAWRENCE RIVER VALLEY IN SRN QUEBEC THEN LIFTING IT NNEWD DURING THE AFTERNOON...PLUS FORECAST SOUNDINGS ARE INDICATING PERSISTENT CLOUD COVER AS WELL AS LIMITED INSTABILITY /MLCAPE MAXING OUT AT 900 J/KG/ AND MOIST ADIABATIC LAPSE RATES OF 6C/KM...SEEMS THAT THE SEVERE POTENTIAL COULD BE MARGINAL AT BEST. COLD FRONTAL BOUNDARY ACCOMPANYING THE MID/UPPER LEVEL TROUGH LOOKS TO BECOME QUASISTATIONARY JUST WEST OF MAINE LEAVING A WEAKENING LINE OF THUNDERSTORMS TO MOVE OVER THE REGION TOMORROW. IF THERE IS ANY PROBABILITY FOR SEVERE...IT WILL BE STRONG WINDS OVER THE EXTREME NWRN AND NRN MAINE WHERE BEST DYNAMICS WILL BRUSH BY THE AREA. ...UPPER MIDWEST/WRN GREAT LAKES REGION... SECOND MID/UPPER LEVEL TROUGH WILL DROP SEWD INTO THE NRN PLAINS AND UPPER MIDWEST REGION DURING THE LATTER HALF OF THE PERIOD. THIS WILL BE ACCOMPANIED BY WEAK FRONTAL BOUNDARY/SURFACE TROUGH THAT WILL EXTEND FROM N CENTRAL MN SWWD INTO SWRN SD BY 12Z WEDNESDAY. MODELS DEPICT AREA OF SCATTERED THUNDERSTORMS WILL DEVELOP ALONG THE SURFACE TROUGH EARLY IN THE PERIOD THROUGH EARLY EVENING...GIVING WAY TO CLUSTER OF STORMS/MCS OVER WI/IA TUE NIGHT AND WED MORNING. STEEP LOW LEVEL LAPSE RATES JUST ABOVE 7.5C/KM INDICATES THAT SOME OF THE STORMS COULD PRODUCE STRONG DOWNBURSTS WITH PROBABILITIES DIMINISHING AFTER SUNSET. ...SOUTHWESTERN U.S.... PERSISTENCE INDICATES THAT SCATTERED STRONG THUNDERSTORMS COULD OCCUR ONCE AGAIN ACROSS THE REGION. ELY MID LEVEL FLOW WILL CONTINUE ACROSS AZ AND PARTS OF NM WITH VERY STEEP LAPSE RATES BELOW 600 MB. THIS ALONG WITH VERY HIGH DCAPE VALUES OVER 1000 J/KG INDICATES THE THREAT FOR STRONG DOWNBURSTS WITH SCATTERED AFTERNOON/EVENING THUNDERSTORMS. ...SOUTH CENTRAL TEXAS EWD INTO LOWER MS VALLEY... MID/UPPER LEVEL LOW IS FORECAST TO DEVELOP OVER S CENTRAL TX DURING THE PERIOD. AIR MASS WILL REMAIN VERY WARM AND MOIST WITH MOIST ADIABATIC LAPSE RATES AND LIMITED INSTABILITY WITH MOST UNSTABLE CAPES BETWEEN 500 AND 800 J/KG. SHEAR PROFILES INCREASE ACROSS S CENTRAL TX AS LOW DEVELOPS INDICATING THE POSSIBILITY OF ISOLATED SUPERCELLS LATE IN THE PERIOD. ..MCCARTHY.. 07/24/2006  From swody2 at goshenarc.org Tue Jul 25 05:58:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 25 Jul 2006 01:58:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250554 SWODY2 SPC AC 250553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT TUE JUL 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL GRTLKS AND UPPER MS VLY REGIONS... ...SYNOPSIS... MID-WEEK UPPER FLOW REGIME WILL MAINTAIN A BROAD UPPER HIGH ACROSS THE SWRN STATES WITH A CENTER OVER THE GRT BASIN REGION. A LARGELY ZONAL PATTERN WILL EXIST ACROSS SRN CANADA AND THE EXTREME NRN PARTS OF THE UNITED STATES. THIS JET STREAM WILL CARRY NUMEROUS SHORTWAVE TROUGHS ACROSS THE NRN TIER OF THE COUNTRY. TWO FEATURES OF NOTE WILL LIKELY MODULATE THE POTENTIAL FOR SEVERE WEATHER. ONE WILL BE A FAIRLY STRONG MID-LEVEL IMPULSE...NOW EVOLVING OVER SRN CANADA. THIS FEATURE WILL MOVE ACROSS THE UPPER MS VLY/GRT LKS REGION ON WED. A SECOND WEAKER SHORTWAVE TROUGH WILL MOVE SEWD ACROSS MT BY WED EVE. AT THE SFC...A COLD FRONT ACCOMPANYING THE LEAD WAVE WILL MOVE SEWD ACROSS THE UPPER MS VLY AND TO THE CNTRL GRTLKS REGION BY 12Z THU. TAIL END OF THIS FRONT WILL REDEVELOP QUICKLY NWD ACROSS THE HIGH PLAINS DURING THE PERIOD. A WEAK LEE-TROUGH WILL EXIST ACROSS THE CNTRL PLAINS AND CORN BELT. ...CNTRL GRTLKS SWWD TO THE CNTRL PLAINS... CONVECTION...LIKELY SUB-SEVERE...WILL BE ONGOING EARLY WED MORNING ACROSS PARTS OF THE CNTRL GRTLKS SWWD INTO THE CORN BELT. THIS ACTIVITY WILL BE KEPT ALIVE THROUGH THE MORNING BY A WEAKENING SWLY LLJ AXIS THAT WILL SHIFT NEWD INTO SRN ONT BY MID-DAY. IN WAKE OF THE MORNING ACTIVITY...THE PRE-FRONTAL AIR MASS IS LIKELY TO BECOME QUITE UNSTABLE OWING TO THE GRADUAL MOISTENING OF THE BOUNDARY LAYER AND VERY STEEP MID-TROPOSPHERIC LAPSE RATES. THE PRIMARY FORCING FOR ASCENT ASSOCIATED WITH THE UPPER WAVE WILL LIKELY BE PASSING ACROSS THE INSTABILITY AXIS BY EARLY AFTN...WITH TSTMS LIKELY DEVELOPING ALONG/AHEAD OF THE COLD FRONT FROM PARTS OF UPPER MI TO NERN IA. VERTICAL SHEAR WILL GENERALLY BE LESS THAN 30-35 KTS...BUT EXPECTED MAGNITUDE OF LAPSE RATES AND MODEST VEERING WINDS WITH HEIGHT SUGGEST THAT SUPERCELLS WILL BE POSSIBLE WITH LARGE HAIL...DAMAGING WINDS AND POSSIBLY AN ISOLD TORNADO. ACTIVITY SHOULD MOVE EWD DURING THE EVENING INTO THE CNTRL GRTLKS REGION AND LIKELY WEAKEN AFTER DARK AS THEY MOVE INTO A MORE STABLE ENVIRONMENT. A SEPARATE REGION OF ENHANCED CONVECTION WILL LIKELY FAVOR PORTIONS OF THE CNTRL PLAINS EWD INTO PARTS OF NRN MO AND CNTRL IL WHERE A SECONDARY LOW-LEVEL THERMAL RIDGE SHOULD EXIST. THIS WILL BE JUST S OF MORNING CONVECTION AND AS THE BOUNDARY LAYER HEATS...LOCAL CONVERGENCE ALONG THE LEE-TROUGH AND/OR OUTFLOW BOUNDARIES MAY SERVE AS A FOCUS FOR TSTMS. THOUGH THE VERTICAL SHEAR THIS FAR S WILL BE MEAGER...LAPSE RATES WILL BE QUITE STEEP THROUGHOUT THE COLUMN AND ISOLD STORMS MAY PRODUCE LARGE HAIL OR DAMAGING WIND GUSTS. ...HIGH PLAINS... HIGH-BASED TSTMS WILL LIKELY DEVELOP ACROSS THE NRN HIGH PLAINS...DOWNSTREAM FROM THE WEAKER SECONDARY IMPULSE DROPPING ESEWD FROM THE SRN CANADIAN ROCKIES. A TONGUE OF INSTABILITY WILL LIKELY ARC NWWD ALONG/N OF THE RETREATING SFC BOUNDARY AND COUPLED WITH 35-40 KTS OF 6KM SHEAR SUGGEST THAT ISOLD ORGANIZED STORMS MAY EVOLVE FROM ERN MT INTO PARTS OF WRN ND WITH POSSIBLE HAIL AND GUSTY WINDS. OTHER STORMS WILL DEVELOP SWD ALONG THE ROCKIES DURING PEAK HEATING AND MAY POSE AN ISOLD DAMAGING WIND THREAT GIVEN THE TYPICAL STEEP LOW-LEVEL LAPSE RATES. ...SWRN DESERTS... HIGHER PWAT VALUES SHOULD BE WELL-ESTABLISHED ACROSS THE LWR DESERTS OWING TO HRCN EMILIA THAT WILL MOVE OFF THE WRN COAST OF BAJA THROUGH WED. DEPENDING ON HOW MUCH RESIDUAL CONVECTIVE DEBRIS IS IN PLACE ON WED...THERE COULD BE ANOTHER ROUND OF ORGANIZED TSTMS WED AFTN/EVE. IT APPEARS...THOUGH...THAT THE STRONGER ENELY FLOW WILL EXIST ACROSS SONORA. WILL MAINTAIN LOW SEVERE PROBABILITIES ATTM. ...MIDDLE/UPPER TX COAST... THERE IS A WIDE SPREAD AMONG THE MODELS IN HANDLING THE TROPICAL WAVE ACROSS THE WRN GULF BASIN. CONSENSUS SUGGESTS THAT THE STRONGEST CONVECTION SHOULD BE CONFINED TO THE COASTAL PLAINS AND OFFSHORE WATERS. FORECAST SOUNDINGS SHOW A HIGH PWAT AIRMASS WITH SUFFICIENT LOW-LEVEL SHEAR FOR PERHAPS AN ISOLD TORNADO OR DAMAGING WIND GUST. ..RACY.. 07/25/2006  From swody2 at goshenarc.org Tue Jul 25 17:02:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 25 Jul 2006 13:02:27 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 251659 SWODY2 SPC AC 251658 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 AM CDT TUE JUL 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NORTH CENTRAL GREAT LAKES.... ...SYNOPSIS... SEVERAL EMBEDDED MINOR SHORTWAVE TROUGHS WILL TRAVEL WITHIN MAIN BAND OF WESTERLIES THAT WILL EXTEND FROM MT THRU THR GREAT LAKES INTO NEW ENGLAND. LARGE MID/UPPER LEVEL RIDGE WILL DOMINATE THE GREAT BASIN AND SWRN STATES...AS WELL AS THE SERN STATES WHILE MID/UPPER LEVEL LOW MOVES NWD ACROSS PARTS OF CENTRAL/ERN TX. ...NORTH CENTRAL GREAT LAKES... MODELS INDICATE THAT MID/UPPER LEVEL TROUGH MOVING INTO THE UPPER MS RIVER VALLEY ON DAY1 WILL SWING EWD/NEWD EARLY IN THE PERIOD FROM ERN WI THRU LOWER MI BEFORE 27/0300Z. BAND OF THUNDERSTORMS ARE EXPECTED ALONG/AHEAD OF WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE TROUGH. DUE TO TIME OF DAY...EXPECT MUCH OF THIS ACTIVITY TO BE NEAR/BELOW SEVERE LEVELS DUE TO LIMITED THERMODYNAMICS. MODELS HINT AT A WEAK BOUNDARY THAT WILL EXTEND SWWD THOUGH FROM NRN INDIANA THRU IL INTO SRN IA. DAYTIME HEATING WILL DESTABILIZE THESE AREAS BY AFTERNOON AIDING IN THE INITIATION OF THUNDERSTORMS ACROSS THESE AREAS. TEMPERATURES AT 500 MB ARE EXPECTED TO REMAIN WARM AROUND -6C...THUS HAVE OPTED FOR A LOW OR ISOLATED PROBABILITY FOR SEVERE THUNDERSTORMS WITH THE POSSIBILITY OF SOME STRONG WIND GUSTS. CONCENTRATED MORE ON WHERE SRN PERIPHERY OF MID/UPPER LEVEL TROUGH WILL MOVE ACROSS UPPER MI/NERN WI AND NRN LOWER MI ON NRN FRINGES OF UNSTABLE AIR MASS WHERE 500 MB TEMPERATURES ARE -8C OR -10C. THIS AREA HAS SOME BETTER SHEAR WITH SWLY LOW LEVEL FLOW OF AROUND 50 KT COUPLED WITH WLY 500 MB FLOW OF 40-50 KT. EXPECT SECONDARY LINE OF STRONG/SEVERE THUNDERSTORMS TO DEVELOP WED AFTN INTO EARLY WED NIGHT WITH THE THREAT OF DAMAGING WINDS AND HAIL. ...PARTS OF CENTRAL AND ERN TX... TROPICAL MID/UPPER LEVEL LOW WILL MOVE NWD FROM THE TX GULF COAST TO AROUND THE DALLAS METROPLEX DURING THE PERIOD. LOW/MID LEVEL FLOW OF 30-40 KT IS FORECAST ON THE ERN SIDE OF THIS SYSTEM THRU ERN TX INTO WRN SECTIONS OF LA. THUS...THERE MAY BE SOME STRONG WIND GUSTS...BUT GIVEN THE MOIST ADIABATIC LAPSE RATES AND MINIMAL DIRECTIONAL SHEAR...ACTIVITY SHOULD REMAIN BELOW SEVERE LEVELS. ..MCCARTHY.. 07/25/2006  From swody2 at goshenarc.org Wed Jul 26 06:00:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 26 Jul 2006 02:00:24 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260557 SWODY2 SPC AC 260556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT WED JUL 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER FLOW PATTERN WILL BEGIN TO TRANSITION AGAIN ON THU AS AN UPPER TROUGH EVOLVES OFF THE PAC NW COAST...WITH A BROAD DOWNSTREAM TROUGH ACROSS THE MIDWEST. THE UPPER HIGH WILL REMAIN IN PLACE ACROSS THE SWRN DESERTS. STRONGEST WLYS WILL REMAIN ACROSS SRN CANADA...BUT A COUPLE OF MODEST SHORTWAVE TROUGHS WILL BE SKIRTING THE NRN TIER OF THE COUNTRY. LEAD IMPULSE WILL TRAVEL FROM THE CNTRL GRTLKS REGION NEWD INTO SRN QUE THU AFTN/NIGHT WHILE DEAMPLIFYING. A SECOND DISTURBANCE WILL MOVE SEWD INTO THE DAKS. THE TROPICAL WAVE MOVING NWD THROUGH THE WRN GULF OF MEXICO CURRENTLY SHOULD MOVE NWD AND COULD PHASE WITH THE NRN STREAM BY THU AFTN...THOUGH MODEL SOLUTIONS ARE HIGHLY VARIED. ...NERN STATES... SRN PERIPHERY OF A LEAD H5 SHORTWAVE TROUGH IS EXPECTED TO SKIRT PARTS OF NRN NEW ENGLAND AND NRN NY STATE THU AFTN. THOUGH MOST FORCING FOR LARGE SCALE ASCENT WILL MOVE THROUGH QUE...THERE WILL BE SLIGHT INCREASE IN THE VERTICAL SHEAR ALONG THE BASE OF THIS TROUGH. DIURNALLY-BASED TSTMS THAT FORM ALONG THE MOUNTAINS AND THE PRE-FRONTAL TROUGH MAY BECOME STRONGER DURING PEAK HEATING DUE TO THE INCREASE IN SHEAR. LACK OF A SUSTAINED FOCUS...HOWEVER... WILL LIMIT THE SEVERE THREATS TO ISOLD LARGE HAIL AND DAMAGING WINDS. ...LWR GRTLKS REGION WWD THROUGH THE OZARKS... RATHER WEAK FLOW REGIME AND WARM TROPOSPHERIC TEMPERATURES SHOULD PRECLUDE WIDESPREAD AND ORGANIZED SEVERE WEATHER ACROSS THIS REGION ON THU. THERE WILL LIKELY CONTINUE TO BE A BROAD LOW-LEVEL CONFLUENCE ZONE ALONG NWRN PERIPHERY OF THE BERMUDA HIGH FROM THE OZARKS NEWD INTO THE LWR GRTLKS REGION. MOREOVER...THERE WILL PROBABLY BE NUMEROUS OUTFLOW BOUNDARIES LOCATED FROM PARTS OF MO NEWD INTO SERN LWR MI AT THE START OF THE PERIOD. THESE BOUNDARIES AND THE BROAD CONFLUENCE WILL LIKELY BE THE FOCUS FOR TSTMS THU AFTN. DEPENDING ON THE TRACK OF THE TROPICAL WAVE...MORE TROPICAL AIR MASS WILL ADVECT NWD INTO PARTS OF THE OZARKS. SLIGHTLY STRONGER LLJ ASSOCIATED WITH THIS SYSTEM MAY BE FAVORABLE FOR ISOLD DAMAGING WIND GUSTS WITH A FEW STORMS. OTHERWISE...FARTHER N AND NE...STEEP LAPSE RATE ENVIRONMENT WILL BE FAVORABLE FOR ISOLD DAMAGING WIND GUSTS AND PERHAPS SMALL HAIL. AT THIS POINT... NARROWING IN ON ANY ENHANCED SEVERE SCENARIO IS NOT POSSIBLE AND LOW SEVERE PROBABILITIES WILL SUFFICE. ...SWRN DESERTS... THERE IS APT TO BE SEVERAL ROUNDS OF TSTMS ACROSS THE SWRN DESERTS DURING WED AND WED NIGHT AND COULD EXHAUST STRONGER INSTABILITY/ LAPSE RATES ACROSS THE SWRN DESERTS FOR THU/THU NIGHT. BUT...THESE DETAILS ARE DIFFICULT TO FORECAST THIS FAR IN ADVANCE. UPSHOT IS THAT BOUNDARY LAYER MOISTURE WILL REMAIN QUITE HIGH AND THERE SHOULD BE SLIGHT COOLING ALOFT OWING TO SLIGHTLY MORE NLY MID-LEVEL FLOW REGIME ON ERN EDGE OF THE UPPER ANTICYCLONE. LOW PROBABILITY SEVERE TSTM RISKS WILL BE MAINTAINED. ..RACY.. 07/26/2006  From swody2 at goshenarc.org Wed Jul 26 16:32:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 26 Jul 2006 12:32:51 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261629 SWODY2 SPC AC 261628 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT WED JUL 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WEAK NEAR-TROPICAL SYSTEM NOW OVER SERN TX IS EXPECTED TO LIFT SLOWLY NNEWD DURING THE NEXT COUPLE OF DAYS INTO THE MID SOUTH AS IT BECOMES ENTRAINED IN WEAK NRN STREAM. IN ADDITION...A SERIES OF IMPULSES WILL PROGRESS EWD ACROSS THE MID WEST AND THE NORTHEAST...WITH UPPER RIDGE HOLDING OVER THE NRN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS. AIR MASS WILL REMAIN QUITE MOIST FROM THE SRN PLAINS INTO THE NORTHEAST...AND ACROSS THE SWRN DESERTS...WHERE SURFACE DEW POINTS IN THE MID/UPPER 60S AND LOWER 70S WILL BE COMMON. ...LOWER MS RIVER VALLEY/MID SOUTH INTO THE SRN GREAT LAKES... COMBINATION OF A VERY MOIST BOUNDARY LAYER AND MODEST TO STRONG HEATING WILL AGAIN SUPPORT A VERY UNSTABLE AIR MASS OVER MUCH OF THIS REGION THURSDAY. OUTFLOW BOUNDARIES AND REMNANTS OF IMPULSE NOW LIFTING INTO SERN TX SHOULD FOCUS SCATTERED THUNDERSTORMS DURING THE FORECAST PERIOD. THOUGH FLOW ALOFT REMAINS QUITE MODEST...DEGREE OF INSTABILITY/LOW LEVEL MOISTURE SHOULD FOCUS A FEW STRONG TO SEVERE THUNDERSTORMS DURING THE AFTERNOON/EVENING WITHIN 15-25 KT EFFECTIVE SHEAR. LOCATION OF ANY INCREASED SEVERE RISK TOO UNCERTAIN ATTM AND WILL MAINTAIN BROAD AREA OF LOW SEVERE PROBABILITIES...THOUGH SLGT RISK MAY BE NEEDED IN LATER OUTLOOKS. ...NORTHEAST... FLOW ALOFT WILL BE A BIT STRONGER ON THURSDAY AS COMPARED TO TODAY AS WELL DEFINED SHORTWAVE TROUGH NOW MOVING ACROSS THE CENTRAL GREAT LAKES LIFTS ENEWD ACROSS QUEBEC. TAIL END OF STRONGER FORCING/ASCENT WILL SKIRT THE REGION AND SHOULD SUPPORT SCATTERED THUNDERSTORMS AS AIR MASS BECOMES MARGINALLY TO MODERATELY UNSTABLE. SURFACE DEWPOINTS IN THE UPPER 60S/LOWER 70S AND EFFECTIVE SHEAR FROM 20-30 KT SHOULD SUPPORT A FEW STRONG TO SEVERE THUNDERSTORMS...MAINLY IN THE FORM OF BRIEFLY-SEVERE WIND GUSTS. HOWEVER...DESPITE THE RICH BOUNDARY LAYER MOISTURE IN PLACE...LAPSE RATES ARE FORECAST TO REMAIN WEAK ATTM AND LIMIT OVERALL SEVERE THREAT. ...SWRN DESERTS... RICH LOW LEVEL MOISTURE WILL AGAIN BE IN PLACE OVER MUCH OF SRN/WRN AZ INTO THE LOWER CO RIVER VALLEY...SUPPORTING MODERATE TO STRONG INSTABILITY. THIS WILL FOCUS SCATTERED TO WIDESPREAD THUNDERSTORMS OVER HIGHER TERRAIN DURING THE AFTERNOON...AND POSSIBLY OVER LOWER ELEVATIONS NEAR RESIDUAL OUTFLOW BOUNDARIES. QUESTIONS REGARDING AVAILABLE LAPSE RATES AND OTHER EFFECTS FROM PRECEDING CONVECTION PRECLUDE ADDING SLGT RISK ATTM. ..EVANS.. 07/26/2006  From swody2 at goshenarc.org Thu Jul 27 05:58:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 27 Jul 2006 01:58:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270555 SWODY2 SPC AC 270553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT THU JUL 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF NEW ENGLAND AND THE MID-ATLANTIC REGION... ...SYNOPSIS... MODELS IN GOOD AGREEMENT AT DIGGING AN UPPER TROUGH OFF THE PAC COAST ON FRI WITH A WEAKLY AMPLIFIED TROUGH LIFTING THROUGH NEW ENGLAND AND MID-ATLANTIC REGIONS. THE MAJORITY OF THE COUNTRY WILL CONTINUE BENEATH A LARGE UPPER HIGH THAT WILL BUILD E AND N WITH A CENTER OVER CO BY EARLY SATURDAY. A COUPLE OF SHORTWAVE TROUGHS WILL BE OF INTEREST. AT THE SFC...A SERIES OF WEAK FRONTS THAT HAVE MOVED SWD IN WAKE OF DISTURBANCES PASSING WELL N OF THE GRTLKS THE PAST COUPLE OF DAYS...WILL BE SITUATED FROM THE MID-ATLANTIC REGION WWD INTO THE CORN BELT. A NEW SYNOPTIC COLD FRONT/PRE-FRONTAL TROUGH WILL BEGIN TO MOVE SEWD ACROSS THE DAKS AND INTO PARTS OF THE UPPER GRTLKS AND UPPER MS VLY REGION BY FRI NIGHT. ...NERN STATES SWD TO THE MID ATLANTIC REGION... THERE WILL LIKELY BE A FAIR AMOUNT OF CONVECTIVE CLOUD DEBRIS ACROSS PRIMARILY SRN PARTS OF NEW ENGLAND AND THE MID-ATLANTIC REGION EARLY ON FRI. THERE IS SOME QUESTION ON HOW THIS WILL AFFECT AIR MASS DESTABILIZATION FRI AFTN ALONG/AHEAD OF THE LEE-TROUGH...PARTICULARLY ACROSS SERN PA...MD...DE...NJ AND VA. NONETHELESS...EVEN MODEST HEATING WILL CREATE AN UNSTABLE ENVIRONMENT GIVEN THE RICH BOUNDARY LAYER MOISTURE IN PLACE. TSTMS WILL LIKELY DEVELOP ALONG/AHEAD OF THE PRE-FRONTAL TROUGH/MOUNTAINS FROM PORTIONS OF NEW ENGLAND SWD INTO NERN PA BY EARLY AFTN. OTHER STORMS ARE POSSIBLE FARTHER S...THOUGH COVERAGE WILL BE MODULATED BY INSTABILITY FACTORS. AS THE UPPER TROUGH BEGINS TO ACCELERATE NEWD...WLY MID-LEVEL FLOW AOA 30 KTS IS EXPECTED ATOP THE SSWLY LOW-LEVEL FLOW. ANY TSTM THAT DEVELOPS IN THIS ENVIRONMENT MAY BECOME ORGANIZED AND PRODUCE MAINLY DAMAGING WINDS. MAIN LIMITING FACTORS FOR A ROBUST SEVERE EVENT WILL BE THE MEAGER MID-LEVEL LAPSE RATES. ACTIVITY SHOULD MAINLY BE DIURNALLY DRIVEN AND WEAKEN DURING THE EVE AND/OR AS STORMS MOVE TO THE MARINE LAYER IN SERN NEW ENGLAND/LONG ISLAND. ...SRN PLATEAU/SWRN DESERTS... THE HIGH PRECIPITABLE WATER AIR MASS ACROSS THE SWRN DESERTS IS APT TO BE ADVECTED NWD INTO PARTS OF THE SRN GRT BASIN AHEAD OF THE DIGGING PAC NW TROUGH ON FRI. THIS MAY SUPPORT A NWD EXPANSION OF THE ISOLD SEVERE THREAT INTO PARTS OF SRN UT AND SWRN CO. FARTHER S...WITH THE EXPECTED INCREASE IN TSTMS OVER AZ AHEAD OF THE MID-LEVEL IMPULSE ON DAY 1 /THU/...THERE COULD VERY WELL BE A DOWN DAY ACROSS THE SWRN DESERTS...DESPITE THE ARRIVAL OF AN INVERTED TROUGH MOVING WWD FROM SRN NM/NRN CHIHUAHUA. BUT... THESE DETAILS ARE DIFFICULT TO ANTICIPATE THIS FAR IN ADVANCE. THUS...WILL CONTINUE AT LEAST ISOLD SEVERE PROBABILITIES OVER THE ENTIRE REGION. ...NRN MN/UPPER GRTLKS REGION... LARGE SCALE HEIGHT RISES AND WARMING ALOFT CAN BE EXPECTED OVER THE MAJORITY OF THE PLAINS ON FRI. THIS SHOULD INHIBIT SFC-BASED TSTM CHANCES ALONG THE SEWD MOVING COLD FRONT EXPECTED TO MOVE ACROSS THE ERN DAKS AND MN FRI AFTN/EVE. BUT...DOWNSTREAM...A WEAKER CAP AND A WEAK INFLUENCE OF A DISTURBANCE PASSING JUST N OF THE REGION WILL EXIST ACROSS PORTIONS OF NERN MN...NRN WI AND UPPER MI. A FEW SFC-BASED STORMS WILL BE POSSIBLE LATE FRI AFTN/EVE ACROSS THE REGIONS...LIKELY TRANSITIONING INTO AN ELEVATED STORM CLUSTER FRI NIGHT. INITIAL ACTIVITY WILL HAVE THE RISKS FOR ISOLD LARGE HAIL AND DAMAGING WINDS...WITH THE SEVERE THREATS DIMINISHING OVERNIGHT AND WITH EWD EXTENT. ..RACY.. 07/27/2006  From swody2 at goshenarc.org Fri Jul 28 05:55:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 28 Jul 2006 01:55:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280555 SWODY2 SPC AC 280554 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT FRI JUL 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...SYNOPSIS... BELT OF STRONGER FLOW WILL PERSIST ALONG THE NRN TIER OF THE U.S. THIS PERIOD. SEVERAL IMPULSES WILL MOVE THROUGH THIS BAND OF FLOW. ONE SUCH FEATURE NOW MOVING INTO THE PACIFIC NW IS FORECAST TO BE OVER THE UPPER MS VALLEY EARLY SATURDAY. A STRONGER UPSTREAM SHORTWAVE TROUGH IS FORECAST TO AMPLIFY INTO THE PACIFIC NW THEN EJECT NEWD THROUGH THE NRN ROCKIES AND INTO SWRN CANADA DURING THE DAY. A BAROCLINIC ZONE WILL EXTEND FROM A SURFACE LOW OVER THE DAKOTAS EWD INTO THE GREAT LAKES AREA. A COLD FRONT WILL APPROACH THE NERN STATES SATURDAY NIGHT. ...UPPER MS VALLEY THROUGH GREAT LAKES AREA... THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE FRIDAY NIGHT AND PERSIST INTO EARLY SATURDAY OVER THE NRN PLAINS OR UPPER MS VALLEY AREA WITHIN ZONE OF WARM ADVECTION AND ISENTROPIC ASCENT N OF SURFACE FRONT. THE ATMOSPHERE IN VICINITY OF THE E-W BOUNDARY AND OUTSIDE OF ONGOING CONVECTION IS EXPECTED TO BECOME MODERATELY UNSTABLE. LOW LEVEL DEWPOINTS IN THE 60S...STEEP MID LEVEL LAPSE RATES AND SURFACE HEATING SHOULD CONTRIBUTE TO MLCAPE AROUND 2000 J/KG. AS THE CAP WEAKENS AND THE ATMOSPHERE DESTABILIZES...IT IS POSSIBLE THAT ONGOING ELEVATED STORMS MAY EVENTUALLY BECOME FORWARD PROPAGATING IF THEY CAN ROOT IN THE BOUNDARY LAYER. OTHER SURFACE BASED STORMS MAY DEVELOP ALONG RESIDUAL OUTFLOW BOUNDARIES...ALONG LAKE BREEZE BOUNDARIES OR IN VICINITY OF THE SURFACE FRONT. LARGE SCALE ASCENT ASSOCIATED WITH EWD ADVANCING MID LEVEL IMPULSE MAY ENHANCE THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER THE GREAT LAKES AREA. BELT OF 35 TO 40 KT MID LEVEL FLOW ABOVE SELY LOW LEVEL FLOW NEAR SURFACE FRONT WILL CONTRIBUTE TO SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORMS INCLUDING SUPERCELLS AND BOW ECHOES. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. OTHER MORE ELEVATED STORMS MAY DEVELOP OVERNIGHT ACROSS THE UPPER MS VALLEY WITH DEVELOPING WARM ADVECTION REGIME. LARGE HAIL SHOULD BE THE MAIN THREAT WITH THAT ACTIVITY. ...NERN U.S... A COLD FRONT WILL MOVE INTO THE NERN STATES SATURDAY EVENING AND OVERNIGHT. THE PRE-FRONTAL WARM SECTOR SHOULD BECOME MODERATELY UNSTABLE DURING THE DAY. THUNDERSTORMS THAT DEVELOP UPSTREAM ACROSS CANADA AND ALONG LAKE BREEZES WITHIN THE PRE-FRONTAL WARM SECTOR MAY SPREAD INTO PARTS OF NY AND NEW ENGLAND DURING THE AFTERNOON. LOW LEVEL FLOW IS EXPECTED TO REMAIN WEAK...BUT WNWLY FLOW INCREASING TO 40-50 KT ABOVE 6 KM MAY RESULT IN SUFFICIENT UNIDIRECTIONAL SHEAR FOR MID LEVEL UPDRAFT ROTATION. ISOLATED STRONG WIND GUSTS AND HAIL COULD ACCOMPANY THE STRONGER STORMS. ...CNTRL AND NRN MT... SHORTWAVE TROUGH WILL EJECT NEWD THROUGH THE NRN ROCKIES AND INTO SWRN CANADA DURING THE DAY. LARGE SCALE ASCENT AND OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE A FEW HIGH BASED STORMS OVER WRN MT. THIS ACTIVITY MAY SUBSEQUENTLY SPREAD NEWD THROUGH PARTS OF NRN AND CNTRL MT. AT THIS TIME IT APPEARS THAT COVERAGE WILL BE TOO ISOLATED AND MOISTURE/INSTABILITY TOO MARGINAL FOR A SLIGHT RISK. ...SWRN U.S.... STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF NM AND AZ AND SUBSEQUENTLY SPREAD SWWD DURING THE DAY. ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ..DIAL.. 07/28/2006  From swody2 at goshenarc.org Fri Jul 28 17:43:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 28 Jul 2006 13:43:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281743 SWODY2 SPC AC 281741 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1241 PM CDT FRI JUL 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...UPPER MS VALLEY THROUGH GREAT LAKES AREA... ACTIVE SEVERE WEATHER DAY APPEARS LIKELY ON SATURDAY FROM THE UPPER MS VALLEY INTO THE CENTRAL GREAT LAKES REGION WITH SEVERAL ROUNDS OF SEVERE STORMS MOVING ESEWD ACROSS THIS REGION. ONE POTENTIALLY SEVERE MCS IS EXPECTED TO BE ONGOING AT 12Z SATURDAY ACROSS PARTS OF ERN ND INTO CENTRAL/NRN MN AS DISCUSSED IN THE SPC DAY 1 CONVECTIVE OUTLOOK...WITH AN ATTENDANT THREAT OF HAIL AND DAMAGING WINDS. THIS MCS WILL BE ASSOCIATED WITH ASCENT AHEAD OF A MID LEVEL SHORT WAVE TROUGH PROGGED TO TRACK ESEWD FROM NWRN MN INTO THE CENTRAL GREAT LAKES BY 30/00Z...AND REACHING NEW ENGLAND BY 12Z SUNDAY. A SURFACE BOUNDARY IS EXPECTED TO REMAIN STATIONARY FROM NRN MI WNWWD THROUGH NRN WI AND CENTRAL MN TO ALONG THE ND/SD BORDER AND WILL BE THE FOCUS FOR STORMS TO TRACK ESEWD THROUGH THESE AREAS DURING DAY 2 PERIOD. AIR MASS ALONG/S OF THIS BOUNDARY IS EXPECTED TO REMAIN VERY MOIST WITH SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70. THIS COMBINED WITH SURFACE HEATING BENEATH ERN EXTENT OF ELEVATED MIXED LAYER WILL RESULT IN AN AMPLE INFLOW...PER 30-35 KT WSWLY LLJ...OF MODERATE INSTABILITY TO ONGOING MCS AS IT TRACKS INTO NRN WI/WRN U.P. OF MI SATURDAY MORNING. NAM POINT FORECAST SOUNDINGS SUGGEST THE LIKELIHOOD FOR THIS MCS TO BECOME SURFACE BASED AS SURFACE HEATING COMMENCES SATURDAY MORNING...WITH INCREASING POTENTIAL FOR DAMAGING WINDS. THIS INITIAL MCS SHOULD REACH PARTS OF NRN LOWER MI SATURDAY AFTERNOON WITH THE CONTINUED THREAT FOR DAMAGING WINDS AND HAIL. GIVEN THE ENHANCED LOW LEVEL SHEAR ALONG SURFACE BOUNDARY PER WSWLY LOW LEVEL WINDS BENEATH 50-60 KT WNWLY MID LEVEL AND HIGH SURFACE DEWPOINTS...THREAT FOR TORNADOES WILL EXIST AS WELL. MODELS SUGGEST A SECOND MCS SHOULD DEVELOP ACROSS PARTS OF NERN MN/NWRN WI AREA BY LATE SATURDAY AFTERNOON/EARLY EVENING AS A SWLY LLJ STRENGTHENS ACROSS THE UPPER MS VALLEY. SUFFICIENT ELEVATED INSTABILITY AND EFFECTIVE BULK SHEAR VALUES INDICATED THIS MCS MAY BE SEVERE AS IT TRACKS ESEWD SATURDAY NIGHT THROUGH THE UPPER GREAT LAKES. ...LOWER GREAT LAKES TO NWRN ME... A COLD FRONT WILL MOVE INTO THE NERN STATES SATURDAY EVENING AND OVERNIGHT. THE PRE-FRONTAL WARM SECTOR SHOULD BECOME MODERATELY UNSTABLE DURING THE DAY. THUNDERSTORMS THAT DEVELOP UPSTREAM ACROSS CANADA AND ALONG LAKE BREEZES WITHIN THE PRE-FRONTAL WARM SECTOR MAY SPREAD INTO PARTS OF NY AND NEW ENGLAND DURING THE AFTERNOON. WEAK LAPSE RATES SUGGEST SEVERE THREAT SHOULD BE MARGINAL. HOWEVER...A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE GIVEN EFFECTIVE BULK SHEAR VALUES OF 25-30 KT RESULTING IN ISOLATED STRONG WIND GUSTS AND HAIL IN THE STRONGER CORES. ...NRN HIGH PLAINS... SHORTWAVE TROUGH WILL TRACK NEWD THROUGH THE NRN ROCKIES AND INTO CANADA DURING THE DAY. LARGE SCALE ASCENT AND OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE A FEW HIGH BASED STORMS OVER WRN MT. THIS ACTIVITY MAY SUBSEQUENTLY SPREAD NEWD THROUGH PARTS OF NRN AND CNTRL MT. ADDITIONAL STORMS MAY DEVELOP ALONG FRONT EXTENDING FROM SERN TO NORTH CENTRAL MT. AT THIS TIME IT APPEARS THAT COVERAGE WILL BE TOO ISOLATED AND MOISTURE/INSTABILITY TOO MARGINAL FOR A SLIGHT RISK ACROSS CENTRAL MT. ALTHOUGH INSTABILITY MAY BE GREATER ACROSS ERN MT INTO ND SATURDAY AFTERNOON/NIGHT...MODEL UNCERTAINTIES IN THE EVOLUTION OF THIS ACTIVITY PRECLUDES A SLIGHT RISK. ...SOUTHWESTERN STATES... AN INVERTED SHORT WAVE TROUGH IS EXPECTED TO WEAKEN AS IT SPREADS WWD ACROSS AZ ON SATURDAY...WHILE A MID LEVEL IMPULSE APPROACHES SWRN NM/SERN AZ SATURDAY AFTERNOON/NIGHT. AIR MASS IN THE LOWER ELEVATIONS/DESERTS OF SRN/WRN AZ IS NOT EXPECTED TO BECOME AS UNSTABLE AS EXPECTED DURING DAY 1. NONETHELESS...THUNDERSTORMS SHOULD DEVELOP OVER THE HIGHER TERRAIN OF NM AND AZ AND SUBSEQUENTLY SPREAD SWWD. ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ...PARTS OF THE CAROLINAS/SRN VA... AIR MASS ACROSS THIS REGION IS EXPECTED TO BECOME MODERATELY UNSTABLE SUPPORTING AFTERNOON/EVENING THUNDERSTORMS AS MID LEVEL IMPULSE TRACKS SLOWLY EWD FROM THE SRN APPALACHIANS THROUGH NC/VA ON SATURDAY. GENERALLY WEAK DEEP LAYER SHEAR SHOULD RESULT IN PULSE-TYPE STORMS WITH STEEP LOW LEVEL LAPSE RATES SUPPORTING ISOLATED STRONG WIND GUSTS AND HAIL WITH THE STRONGER STORMS. ..PETERS.. 07/28/2006  From swody2 at goshenarc.org Sat Jul 29 05:35:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 29 Jul 2006 01:35:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290535 SWODY2 SPC AC 290533 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 AM CDT SAT JUL 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...SYNOPSIS... LARGE UPPER RIDGE CENTERED OVER THE CNTRL U.S. WILL DOMINATE MOST OF THE COUNTRY...WITH STRONGER BELT OF WLYS REMAINING OVER THE NRN TIER STATES. A POSITIVELY TILTED SHORTWAVE TROUGH WILL AMPLIFY INTO THE PACIFIC NW THEN EJECT NEWD INTO SWRN CANADA. A BROAD...LOW AMPLITUDE UPPER TROUGH WILL PERSIST ACROSS SERN CANADA INTO THE NERN STATES. POTENTIAL ALSO WILL EXIST FOR A SERIES OF SMALLER SCALE VORTICITY MAXIMA TO MOVE THROUGH THE BELT OF STRONGER FLOW. A COLD FRONT WILL MOVE INTO THE NERN STATES...BUT SHOULD STALL DURING THE DAY. THIS BOUNDARY WILL EXTEND NWWD THROUGH THE GREAT LAKES AREA AND TO A SURFACE LOW ACROSS ND. THE WRN PORTION OF THIS BOUNDARY WILL LIFT NWD AS A WARM FRONT. A COLD FRONT WILL ALSO MOVE THROUGH ERN MT INTO ND. ...NERN ND THROUGH NRN MN AND GREAT LAKES AREA... STRONGER BELT OF WLYS WILL MAINTAIN LAPSE RATE PLUME AS FAR EAST AS THE GREAT LAKES. RICH LOW LEVEL MOISTURE WILL PERSIST ALONG AND S OF THE FRONT WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. THESE FACTORS WILL CONTRIBUTE TO POTENTIAL FOR STRONG INSTABILITY WHERE SURFACE HEATING DEVELOPS. PRIMARY UNCERTAINTIES ARE TIMING OF INDIVIDUAL VORT MAXES AND EVOLUTION OF ONGOING CONVECTION. MODELS SUGGEST THAT STORMS MAY BE ONGOING WITHIN ZONE OF WARM ADVECTION FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES AREA EARLY SUNDAY. THIS ACTIVITY WILL SPREAD SEWD AND POTENTIAL WILL EXIST FOR NEW DEVELOPMENT ALONG ASSOCIATED OUTFLOW BOUNDARIES DURING THE AFTERNOON. ON THE LARGER SCALE...HEIGHTS ARE FORECAST TO BUILD FROM THE NRN PLAINS INTO THE UPPER MS VALLEY WITHIN ZONE OF LOW LEVEL WARM AIR ADVECTION. RISING HEIGHTS AND PRESENCE OF EML SUGGEST THUNDERSTORM INITIATION MAY OCCUR FARTHER N THAN PREVIOUS DAYS. NEW INITIATION MAY WAIT UNTIL EVENING AS THE LOW LEVEL JET INCREASES...ENHANCING LIFT N OF BAROCLINIC ZONE FROM NRN MN...EXTREME NRN WI INTO THE UPPER PENINSULA OF MI. VERTICAL SHEAR IN THE 0-6 KM LAYER ON THE ORDER OF 40 KT WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS...ESPECIALLY IF STORMS DEVELOP EARLY ENOUGH TO BE NEAR SURFACE BASED. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. ...ERN PORTIONS OF THE OH VALLEY THROUGH NERN U.S.... STORMS MAY DEVELOP IN MORE WEAKLY CAPPED WARM SECTOR FROM OH INTO PA AND WRN NY S OF FRONT EXPECTED TO EXTEND FROM NW-SE ACROSS A PORTION OF NEW YORK. THE ATMOSPHERE IN THIS REGION WILL BECOME MODERATELY UNSTABLE DURING THE AFTERNOON. STRONGEST FLOW IN THE 0-6 KM LAYER WILL REMAIN FARTHER NE ON COOL SIDE OF THE FRONT WITH MODEST DEEP LAYER VERTICAL SHEAR AND MID LEVEL LAPSE RATES IN WARM SECTOR. A FEW MULTICELL STORMS CAPABLE OF PRODUCING ISOLATED STRONG TO DAMAGING WIND GUSTS WILL BE THE MAIN THREAT. ...SWRN U.S.... UPPER LOW OVER THE SWRN STATES IS FORECAST TO MOVE LITTLE THROUGH THIS PERIOD. STORMS WILL LIKELY DEVELOP OVER THE HIGHER TERRAIN AS OROGRAPHIC FORCING AND HEATING INCREASE DURING THE AFTERNOON. THE THERMODYNAMIC ENVIRONMENT WITH MODERATE INSTABILITY AND STEEP LAPSE RATES WILL SUPPORT THE POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS AND HAIL WITH THE STRONGER STORMS. ..DIAL.. 07/29/2006  From swody2 at goshenarc.org Sat Jul 29 17:46:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 29 Jul 2006 13:46:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291746 SWODY2 SPC AC 291745 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 PM CDT SAT JUL 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS EXTENDING FROM NRN ND/MN THROUGH GREAT LAKES REGION TO PARTS OF SRN NY/PA/NWRN NJ... ...SYNOPSIS... LONG WAVE TROUGH WILL DEVELOP SWD ALONG THE WEST COAST ON SUNDAY RESULTING IN DOWNSTREAM RIDGE BUILDING EWD...AND EXTENDING FROM THE MS VALLEY INTO ONTARIO/HUDSON BAY BY 12Z MONDAY. STRONGER BELT OF WLYS WILL REMAIN ALONG THE NRN TIER STATES...WITH THE PRIMARY ZONE OF NWLY FLOW ALOFT EXTENDING FROM FAR NRN MN THROUGH THE GREAT LAKES TO MID ATLANTIC/NERN STATES. MODELS ARE IN GENERAL AGREEMENT WITH EJECTING A PACIFIC SHORT WAVE TROUGH NEWD ACROSS THE NRN ROCKIES SUNDAY INTO SRN ALBERTA/SASKATCHEWAN...WHILE A LOW AMPLITUDE TROUGH PERSISTS ACROSS SERN CANADA AND NERN STATES. POTENTIAL ALSO EXISTS FOR SEVERAL SMALLER SCALE VORTICITY MAXIMA TO MOVE THROUGH THE BELT OF STRONGER FLOW. IN THE LOW-LEVELS...A COLD FRONT IS EXPECTED TO STALL FROM SRN NEW ENGLAND INTO SRN NY...WITH THIS BOUNDARY EXTENDING WNWWD THROUGH THE GREAT LAKES REGION TO A SURFACE LOW OVER THE DAKOTAS. THE WRN EXTENT OF THIS BOUNDARY WILL LIFT NWD AS A WARM FRONT ACROSS NRN PLAINS/NRN MS VALLEY. ...NERN ND THROUGH NRN MN AND GREAT LAKES REGION... RICH LOW LEVEL MOISTURE WILL PERSIST ALONG/S OF THE SURFACE FRONT WHILE STRONGER BELT OF WLYS MAINTAINS A PLUME OF STEEP LAPSE RATES INTO THE GREAT LAKES. THESE FACTORS WILL CONTRIBUTE TO MODERATE TO STRONG INSTABILITY FOR THUNDERSTORM DEVELOPMENT ALONG THE SURFACE BOUNDARY AND/OR CONVECTIVE OUTFLOW BOUNDARIES FROM DAY 1 ACTIVITY AS WEAK IMPULSES TRAVERSE THIS REGION. THE FOLLOWING IS A LIKELY SCENARIO FOR DAY 2 SEVERE. AN MCS... POTENTIALLY SEVERE...SHOULD BE ONGOING AT 12Z SUNDAY ACROSS PARTS OF THE NRN MS VALLEY/WRN GREAT LAKES REGION PER SPC DAY 1 CONVECTIVE OUTLOOK. THIS ACTIVITY MAY WEAKEN IN THE MORNING WITH THUNDERSTORM REDEVELOPMENT DOWNSTREAM ACROSS THE GREAT LAKES SUNDAY AFTERNOON INTO THE EVENING. DEEP LAYER SHEAR WILL BE SUFFICIENT FOR SEVERE STORM ORGANIZATION. SEVERE THREAT SHOULD THEN SHIFT FARTHER NWWD AS THE SURFACE FRONT MOVES NWD AND THE RIDGE BUILDS INTO THIS REGION. STRENGTHENING SSWLY PLAINS LLJ SHOULD FOCUS STRONGEST CONVERGENCE ALONG THE U.S./CANADIAN BORDER FROM NRN ND/MN INTO THE UPPER GREAT LAKES REGION WITH POTENTIAL FOR AN OVERNIGHT MCS OVER THIS REGION. ...LOWER GREAT LAKES TO MID ATLANTIC/SWRN NEW ENGLAND REGION... AIR MASS IS ALSO EXPECTED TO BECOME MODERATELY UNSTABLE ALONG/S OF SURFACE BOUNDARY...ESPECIALLY IN AREAS OF STRONGEST SURFACE HEATING. MODELS DIFFER IN THE STRENGTH OF THE NWLY MID LEVEL FLOW/DEEP LAYER SHEAR EXPECTED ACROSS THIS REGION ON DAY 2. NONETHELESS...EVEN THE WEAKER GFS SUGGESTS DEEP LAYER SHEAR WILL BE SUFFICIENT FOR MULTICELLS /SFC-6 KM SHEAR 20-30 KT/. ALTHOUGH MID LEVEL LAPSE RATES WILL BE WEAK...MODERATE INSTABILITY AND THE EXPECTED SHEAR SHOULD BE ADEQUATE FOR AT LEAST A FEW SEVERE STORMS WITH DAMAGING WINDS/HAIL THE PRIMARY THREATS. THUS...HAVE EXTENDED SLIGHT RISK SEWD INTO THE LOWER GREAT LAKES AND PARTS OF THE MID ATLANTIC REGION. ...CENTRAL/ERN MT TO WRN ND... ASCENT AHEAD OF EJECTING PACIFIC SHORT WAVE THROUGH MAY PROMOTE THUNDERSTORM DEVELOPMENT ACROSS THE HIGHER TERRAIN OF THE NRN ROCKIES SUNDAY AFTERNOON...WITH ACTIVITY DEVELOPING NEWD INTO CENTRAL/ERN MT AND WRN ND. WEAK INSTABILITY IN THE VICINITY OF THE INITIAL STORMS SHOULD PRECLUDE A SEVERE THREAT ACROSS WRN MT...BUT GREATER INSTABILITY FARTHER EAST SUGGESTS A FEW STORMS MAY BECOME SEVERE BY SUNDAY EVENING. ...SWRN STATES... ASCENT IN VICINITY OF WEAK UPPER CIRCULATION EXPECTED ACROSS ERN AZ/WRN NM AND WITHIN MOIST AIR MASS SHOULD PROMOTE THUNDERSTORM DEVELOPMENT ACROSS THE SWRN STATES ON DAY 2. MARGINAL TO MODERATE INSTABILITY AND GENERALLY WEAK DEEP LAYER SHEAR SUGGESTS STORM MODE SHOULD BE PULSE WITH ISOLATED STRONG WIND GUSTS THE GREATEST THREAT. ..PETERS.. 07/29/2006  From swody2 at goshenarc.org Mon Jul 31 05:45:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 31 Jul 2006 01:45:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 310546 SWODY2 SPC AC 310544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON JUL 31 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE CNTRL AND NRN PAINS INTO THE UPPER MS VALLEY AND GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF NEW ENGLAND... ...SYNOPSIS... THE COLD FRONT CURRENTLY FROM CNTRL CANADA SWWD INTO THE NRN ROCKIES WILL MOVE SEWD INTO THE GREAT LAKES AND CNTRL PLAINS THIS PERIOD. BY EARLY TUESDAY THIS BOUNDARY IS FORECAST TO EXTEND FROM EXTREME NRN WI SWWD THROUGH NEB INTO SERN WY. THE FRONT MAY BECOME STATIONARY OR LIFT SLIGHTLY NWD OVER THE PLAINS AS A WEAK LEE CYCLONE DEVELOPS IN RESPONSE TO AN APPROACHING UPPER TROUGH. FARTHER EAST A WARM FRONT WILL LIFT NEWD THROUGH NEW ENGLAND AS A SURFACE LOW AND ATTENDANT MID LEVEL JET ADVANCE EWD THROUGH SERN CANADA. THIS REGION WILL REMAIN UNDER THE INFLUENCE OF A BELT OF MODERATE WNWLY MID LEVEL FLOW. ...GREAT LAKES AND UPPER MS VALLEY THROUGH CNTRL/NRN PLAINS AREA... COLD FRONT FORECAST TO STRETCH FROM THE GREAT LAKES SWWD INTO PARTS OF NEB WILL PROVIDE A FOCUS FOR THUNDERSTORMS TUESDAY. AN AXIS OF LOW LEVEL DEWPOINTS IN THE 60S WILL PERSIST IN VICINITY OF THE FRONT...AND SWLY FLOW IN ADVANCE OF THE UPPER TROUGH WILL MAINTAIN AN ELEVATED MIXED LAYER PLUME OVER THIS REGION. MODERATE INSTABILITY IS EXPECTED AS THE BOUNDARY LAYER WARMS DURING THE AFTERNOON. THE HEIGHT GRADIENT WILL INCREASE OVER THE CNTRL PLAINS AS THE UPPER TROUGH ADVANCES INTO THE CNTRL/NRN ROCKIES. POTENTIAL WILL EXIST FOR WEAKER IMPULSES TO EJECT NEWD THROUGH THE CNTRL PLAINS AHEAD OF APPROACHING UPPER TROUGH AS THE MID LEVEL FLOW INCREASES. STORMS SHOULD REDEVELOP DURING THE DAY...ESPECIALLY ALONG AND JUST N OF THE FRONT FROM PARTS OF NEB NEWD INTO THE GREAT LAKES. STRONGEST VERTICAL SHEAR WILL REMAIN IN POST FRONTAL REGION WHERE ENELY LOW LEVEL FLOW WILL EXIST ABOVE 30 KT MID LEVEL FLOW...RESULTING IN 35 TO 40 KT DEEP LAYER SHEAR. THIS SUGGESTS SOME SUPERCELL STRUCTURES WILL BE POSSIBLE WITH ANY SURFACE BASED STORMS ALONG THE FRONT. OTHERWISE...MULTICELL CLUSTERS SHOULD BE THE DOMINANT STORM TYPE. DAMAGING WIND AND HAIL WILL BE THE MAIN THREATS. THUNDERSTORM COVERAGE WILL LIKELY INCREASE OVER THE UPPER MS VALLEY AND STORMS MAY EVOLVE INTO AN MCS DURING THE EVENING AS THE LOW LEVEL JET INCREASES AND ENHANCES LIFT N OF THE FRONT. ...NERN U.S.... MODERATELY UNSTABLE WARM SECTOR WILL SPREAD THROUGH NEW ENGLAND IN WAKE OF WARM FRONT THAT WILL MOVE EWD IN RESPONSE TO EWD ADVANCING SURFACE LOW OVER SERN CANADA. A STRONG MID LEVEL JET MOVING INTO SERN CANADA WILL KEEP THE UPPER RIDGE SUPPRESSED...RESULTING IN MODERATE 35 TO 40 KT MID LEVEL FLOW. WLY LOW LEVEL FLOW WILL ALSO INCREASE OVER NEW ENGLAND AS SURFACE LOW AND MID LEVEL JET ADVANCE EWD THROUGH SERN CANADA. THIS WILL RESULT IN MODERATELY STRONG WLY DEEP LAYER WIND PROFILES. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP IN THE WARM ADVECTION REGIME ALONG RETREATING WARM FRONT. OTHER STORMS MAY DEVELOP OVER CANADA AND SPREAD SEWD THROUGH NEW ENGLAND DURING THE DAY. DAMAGING WIND WILL BE THE PRIMARY THREAT WITH THE STRONGER STORMS. WARM MID LEVEL TEMPERATURES WITH -4C AT 500 MB WILL LIMIT OVERALL LARGE HAIL THREAT. ..DIAL.. 07/31/2006  From swody2 at goshenarc.org Mon Jul 31 17:00:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 31 Jul 2006 13:00:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 311700 SWODY2 SPC AC 311659 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT MON JUL 31 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NORTHERN NY AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO THE GREAT LAKES REGION... LARGE UPPER RIDGE WILL DOMINATE THE WEATHER OVER THE SOUTH-CENTRAL AND SOUTHEAST UNITED STATES ON TUESDAY...WITH BAND OF MODERATELY STRONG WESTERLY MID LEVEL WINDS STRETCHING FROM THE NORTHERN ROCKIES INTO NEW ENGLAND. SEVERAL EMBEDDED FEATURES IN THIS FLOW WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS FROM THE DAKOTAS...ACROSS THE GREAT LAKES REGION...INTO PARTS OF NY/NEW ENGLAND. ...NY/NEW ENGLAND... WATER VAPOR IMAGERY SHOWS SERIES OF IMPULSES TRACKING ACROSS ONTARIO/QUEBEC. THIS SCENARIO WILL CONTINUE TOMORROW WITH NAM/GFS DIFFERING ON TIMING AND PLACEMENT OF INDIVIDUAL SYSTEMS. RATHER STRONG DEEP LAYER WESTERLY FLOW IS EXPECTED TO DEVELOP BY TUESDAY AFTERNOON ACROSS NY AND NORTHERN NEW ENGLAND. THIS WILL HELP TO TRANSPORT STEEP LAPSE RATES EASTWARD...WITH 850MB TEMPERATURES OVER 20C ACROSS MUCH OF THE AREA. VERY MOIST BOUNDARY LAYER DEWPOINTS IN THE UPPER 60S/LOWER 70S WILL CONTRIBUTE TO MLCAPE VALUES OVER 3000 J/KG. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL MOVE FROM SOUTHERN QUEBEC INTO NORTHERN NY/VT/NH TUESDAY AFTERNOON. THIS ACTIVITY SHOULD TRACK EASTWARD ACROSS MUCH OF ME DURING THE AFTERNOON/EVENING. TIMING IS IN QUESTION. HOWEVER...VERY FAVORABLE THERMODYNAMIC AND KINEMATIC PARAMETERS ARE IN PLACE FOR A LONG LIVED MCS PRODUCING DAMAGING WINDS IF MESOSCALE DETAILS FALL INTO PLACE. ...CENTRAL PLAINS INTO GREAT LAKES... SURFACE COLD FRONT IS FORECAST TO EXTEND FROM SOUTHWEST NEB INTO WI TUESDAY AFTERNOON. FULL SUNSHINE AND HOT TEMPERATURES WILL LEAD TO A DEEP MIXED BOUNDARY LAYER ACROSS PARTS OF KS/NEB/IA...LIKELY RESULTING IN SCATTERED HIGH-BASED THUNDERSTORMS. INCREASING LOW/MID LEVEL WIND FIELDS AND MODERATE INSTABILITY WILL ENHANCE THE THREAT OF ISOLATED DAMAGING WINDS ACROSS THIS REGION. FARTHER NORTHEAST OVER MN/WI...CONVERGENCE ALONG THE FRONT WILL ALSO HELP TO ORGANIZE CONVECTION WITH THE THREAT OF HAIL AND DAMAGING WINDS IN STRONGER CELLS. ..HART.. 07/31/2006  From swody2 at goshenarc.org Sat Jul 1 05:47:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 01 Jul 2006 01:47:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 010547 SWODY2 SPC AC 010546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT SAT JUL 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND AND THE MIDDLE ATLANTIC STATES WWD INTO PORTIONS OF THE UPPER MIDWEST AND CNTRL PLAINS... ...SYNOPSIS... MODERATELY STRONG /45-55 KT/ CYCLONIC...MID-LEVEL FLOW REGIME WILL BE MAINTAINED THROUGH THE PERIOD FROM THE UPPER MS VALLEY EWD THROUGH THE GREAT LAKES AND INTO THE NERN STATES. LOW-AMPLITUDE SHORT WAVE TROUGH /INITIALLY OVER SRN QUEBEC INTO THE UPPER HUDSON VALLEY/ WILL MOVE ACROSS NRN/CNTRL NEW ENGLAND SUNDAY...WITH SEVERAL WEAKER...UPSTREAM IMPULSES TRANSLATING FROM THE NRN PLAINS/UPPER MS VALLEY EWD ACROSS THE GREAT LAKES. IN THE LOW-LEVELS...PRIMARY SURFACE LOW ATTENDANT TO THE SRN QUEBEC IMPULSE WILL REMAIN N OF INTERNATIONAL BORDER OVER CNTRL OR SRN QUEBEC WHILE TRAILING FRONTAL BOUNDARY PUSHES EWD THROUGH THE HUDSON VALLEY AND NEW ENGLAND. WRN EXTENSION OF THIS FRONT WILL REMAIN QUASI-STATIONARY ACROSS THE NRN OH VALLEY/SRN GREAT LAKES WWD TO SECONDARY LOW PRESSURE OVER THE CNTRL HIGH PLAINS. MEANWHILE... ANOTHER WEAK COLD FRONT WILL PUSH SEWD THROUGH THE NRN PLAINS AND UPPER MS VALLEY. ...NEW ENGLAND/MIDDLE ATLANTIC STATES... RELATIVELY STEEP LOW/MID-LEVEL LAPSE RATES COUPLED WITH BOUNDARY-LAYER DEWPOINTS IN THE 60S ARE EXPECTED TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS SUNDAY WITH MLCAPES RANGING FROM AROUND 1000 J/KG OVER PORTIONS OF NRN/CNTRL NEW ENGLAND TO 1500-2500 J/KG FROM SRN ENGLAND SWWD THROUGH THE LOWER HUDSON AND DE RIVER VALLEYS INTO SRN PA. CLUSTERS OF TSTMS SHOULD BE ONGOING SUNDAY MORNING OVER PORTIONS OF UPSTATE NY IN ADVANCE OF MIGRATORY SHORT WAVE TROUGH. WSWLY LLJ WILL MAINTAIN AN INFLUX OF THIS MODERATELY UNSTABLE AIR MASS INTO SRN AND SWRN FLANK OF STORM COMPLEX...PROMOTING INTENSIFICATION OF THIS ACTIVITY BY AFTERNOON AS IT MOVES THROUGH NRN AND CNTRL NEW ENGLAND. ADDITIONAL STORM DEVELOPMENT APPEARS LIKELY ALONG TRAILING OUTFLOW OR SYNOPTIC FRONT ACROSS SRN NEW ENGLAND WWD INTO THE LOWER HUDSON VALLEY AND PARTS OF SRN NY/PA/NJ. WHILE PRIMARY CONVECTIVE MODE WILL LIKELY REMAIN LINEAR...ESPECIALLY ACROSS NRN PORTIONS OF THE DISCUSSION AREA...FORECAST HODOGRAPHS OVER SRN NEW ENGLAND INTO THE MID/LOWER HUDSON VALLEY INDICATE A DISTINCT THREAT OF SUPERCELLS GIVEN MORE DISCRETE STORM INITIATION. DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY SEVERE WEATHER THREATS...HOWEVER TORNADOES WILL BE POSSIBLE WITH ANY SUPERCELLS THAT CAN BECOME ESTABLISHED. ...SRN GREAT LAKES/OH VALLEY WWD INTO PORTIONS OF THE UPPER MIDWEST AND CNTRL PLAINS... A MODERATELY UNSTABLE AIR MASS /MLCAPES OF 1500-2500 J/KG/ IS FORECAST TO DEVELOP ALONG LENGTH OF QUASI-STATIONARY BOUNDARY OWING TO STEEP LAPSE RATES AND DEWPOINTS IN THE 60S. PERSISTENT LOW-LEVEL CONVERGENCE COUPLED WITH THE INFLUENCE OF WEAK IMPULSES EMBEDDED IN PROGRESSIVE MID-LEVEL PATTERN WILL AID IN THE DEVELOPMENT OF SCATTERED TSTMS DURING THE AFTERNOON AND EVENING HOURS FROM OH/IND AND SRN LOWER MI WWD INTO IA/NEB. ADDITIONAL STORMS WILL ALSO BE POSSIBLE ALSO WEAK COLD FRONT PUSHING SEWD THROUGH THE ERN DAKOTAS AND MN. WHILE THE STRONGEST MID AND HIGH-LEVEL WIND FIELDS WILL RESIDE N OF PRIMARY INSTABILITY AXIS...SUFFICIENT DEEP-LAYER SHEAR /30-40 KTS THROUGH THE LOWEST 6 KM/ WILL EXIST ALONG FRONTAL ZONE...SUPPORTIVE OF ORGANIZED SEVERE STORMS INCLUDING A FEW SUPERCELLS AND BOWING STRUCTURES. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY SEVERE WEATHER HAZARDS. ...ORE... FORCING FOR ASCENT ASSOCIATED WITH APPROACHING SHORT WAVE TROUGH WILL EFFECTIVELY STEEP LAPSE RATES...CONTRIBUTING TO WEAK TO MODERATE INSTABILITY WITH MLCAPES OF 500-1000 J/KG. DAYTIME HEATING IN CONJUNCTION WITH THIS FORCING WILL SUPPORT SCATTERED TSTM DEVELOPMENT BY LATE AFTERNOON INTO THE EVENING...MAINLY E OF THE CASCADES. ISOLATED LARGE HAIL AND/OR LOCALLY GUSTY WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS...THOUGH THE RELATIVELY WEAK VERTICAL SHEAR SHOULD LIMIT A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 07/01/2006  From swody2 at goshenarc.org Sat Jul 1 17:22:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 01 Jul 2006 13:22:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 011721 SWODY2 SPC AC 011720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 PM CDT SAT JUL 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS...CNTRL PLAINS...OH VALLEY...NRN APPALACHIAN MTNS...MID-ATLANTIC AND NEW ENGLAND... ...OH VALLEY... WEST TO NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH SUNDAY ACROSS THE NRN US WITH A BROAD UPPER-LEVEL TROUGH OVER SERN CANADA AND THE GREAT LAKES REGION. MODEL FORECASTS BRING SEVERAL MINOR SHORTWAVE TROUGHS ACROSS THE REGION SUNDAY WHICH SHOULD PROVIDE SUPPORT FOR SCATTERED TO NUMEROUS THUNDERSTORMS ALONG A QUASI-STATIONARY FRONTAL BOUNDARY SITUATED FROM IA EXTENDING EWD ACROSS NRN IL...NRN IND AND OH. BOTH THE WRF AND GFS DEVELOP A POCKET OF MODERATE TO STRONG INSTABILITY ACROSS THE NRN OH VALLEY ALONG AND JUST SOUTH OF THE FRONT. IN ADDITION...FORECAST SOUNDINGS SHOW MODERATE VERTICAL SHEAR SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS AND/OR BOW ECHOES. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER STORMS IN THE LATE AFTERNOON AND EARLY EVENING. AS STORM COVERAGE EXPANDS DURING THE EVENING...THE WIND DAMAGE POTENTIAL MAY BECOME ENHANCED WITH ANY MCS THAT ORGANIZES AND TRACKS SEWD ACROSS THE REGION. ...NERN US... A BROAD SERN CANADA UPPER-LEVEL TROUGH WILL REMAIN IN PLACE THROUGH SUNDAY AS A 70 KT MID-LEVEL JET DRIFTS EWD ACROSS SRN QUEBEC. LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH AND LIFT FROM THE RIGHT REAR QUADRANT OF THE MID-LEVEL JET SHOULD SUPPORT STRONG THUNDERSTORM DEVELOPMENT ACROSS THE REGION SUNDAY AFTERNOON. THUNDERSTORMS WILL LIKELY INITIATE IN THE NRN APPALACHIAN MTNS AND SPREAD EWD INTO THE MID-ATLANTIC AND SRN NEW ENGLAND BY LATE AFTERNOON. MODEL FORECASTS SHOW AN AXIS OF MODERATE INSTABILITY EXTENDING NWD THROUGH NJ INTO THE NEW YORK CITY AREA. THIS COMBINED WITH 30 TO 40 KT OF MID-LEVEL FLOW SHOULD PROVIDE VERTICAL SHEAR SUFFICIENT FOR SUPERCELLS AND/OR BOW ECHOES. UNIDIRECTIONAL WIND PROFILES AND STEEP LOW-LEVEL LAPSE RATES WILL FAVOR WIND DAMAGE AS THE MOST WIDESPREAD THREAT ALTHOUGH HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS. ...HIGH PLAINS/CNTRL PLAINS... WEST TO NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS THE REGION TONIGHT INTO SUNDAY. AT THE SFC...UPSLOPE FLOW WILL CONTINUE ACROSS NEB...NERN CO AND SERN WY. THIS WILL REINFORCE 50S TO LOWER 60S F DEWPOINTS IN THE HIGH PLAINS. THUNDERSTORMS WILL LIKELY INITIATE IN THE HIGHER TERRAIN OF SERN WY AND NERN CO WITH ADDITIONAL DEVELOPMENT POSSIBLE IN THE CNTRL PLAINS ALONG ANY PREEXISTING BOUNDARIES AS SFC TEMPS WARM DURING THE DAY. FORECAST SOUNDINGS SUNDAY AFTERNOON ACROSS THE REGION SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE MAINLY FROM STRONG VEERING IN THE LOW TO MID-LEVELS. THIS COMBINED WITH MODERATE INSTABILITY WILL BE SUFFICIENT FOR SUPERCELLS. VERY STEEP MID-LEVEL LAPSE RATES WILL FAVOR LARGE HAIL AS THE GREATEST THREAT...ALTHOUGH ISOLATED WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY ALONG THE LEADING EDGE OF ANY MCS THAT ORGANIZES AND MOVES EWD ACROSS THE REGION IN THE EVENING. ..BROYLES.. 07/01/2006  From swody2 at goshenarc.org Sun Jul 2 05:19:50 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 02 Jul 2006 01:19:50 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 020519 SWODY2 SPC AC 020518 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1218 AM CDT SUN JUL 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OF THE UPPER MIDWEST/CNTRL GREAT LAKES INTO MID MO VALLEY... ...SYNOPSIS... MID AND UPPER-LEVEL LOW WILL SLOWLY SHIFT EWD ACROSS NRN ONTARIO DURING THE DAY TWO PERIOD WITH A SERIES OF IMPULSES ROTATING THROUGH THE BASE OF THIS FEATURE ACROSS THE UPPER MS VALLEY AND GREAT LAKES. FATHER W...AMPLIFIED RIDGE WILL PERSIST OVER WRN CANADA AND THE INTERMOUNTAIN W...DOWNSTREAM FROM UPPER LOW OVER THE NERN PACIFIC. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WILL CONCURRENTLY SHIFT EWD ACROSS NRN ONTARIO WITH ATTENDANT UPPER SYSTEM. MEANWHILE... TRAILING COLD FRONT WILL PUSH SEWD THROUGH THE UPPER MIDWEST INTO CNTRL GREAT LAKES...WITH SWWD EXTENSION OF BOUNDARY THROUGH THE MID/LOWER MO VALLEY INTO CNTRL HIGH PLAINS. ...UPPER MIDWEST/CNTRL GREAT LAKES INTO THE MID MO VALLEY... COLD FRONT PUSHING SEWD THROUGH THE REGION WILL BE THE PRIMARY FEATURE FOCUSING STRONG TO SEVERE TSTM DEVELOPMENT MONDAY AFTERNOON AND NIGHT. AHEAD OF THE BOUNDARY...DEWPOINTS ARE EXPECTED TO REMAIN IN THE 60S. DAYTIME HEATING AND MODERATELY STEEP LAPSE RATES IN CONJUNCTION WITH THIS MOISTURE WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS WITH MLCAPES OF 1000-2000 J/KG. TSTMS ARE FORECAST TO BECOME INCREASINGLY LIKELY ALONG FRONT OVER PORTIONS OF NRN/CNTRL WI INTO CNTRL/SRN MN BY AFTERNOON AS HEIGHT FALLS ASSOCIATED WITH SHORT WAVE TROUGH ROTATING SEWD THROUGH THE WRN GREAT LAKES BEGINS TO OVERSPREAD WARM SECTOR. WITH TIME...STORMS SHOULD MOVE/DEVELOP INTO THE CNTRL GREAT LAKES...AND SWWD INTO THE MID MO VALLEY. LARGELY UNIDIRECTIONAL WIND FIELDS WILL LIKELY SUPPORT LINE SEGMENTS OR STORM CLUSTERS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. UPSCALE GROWTH INTO LARGER CLUSTERS OR AN MCS OR TWO IS ANTICIPATED MONDAY NIGHT WITH A MARGINAL WIND/HAIL THREAT SPREADING INTO THE NRN OH VALLEY WWD TO THE LOWER MO VALLEY. ...HUDSON VALLEY SWD INTO ERN NC... BOTH THE NAM AND GFS INDICATE THE PASSAGE OF A WEAK FRONT OR TROUGH THROUGH THE REGION MONDAY WHICH MAY FOCUS ISOLATED STRONG TO POTENTIALLY SEVERE STORMS. THE STRONGER WIND FIELDS WILL REMAIN TO THE N ACROSS THE HUDSON VALLEY...WHILE AIR MASS IS FORECAST TO BECOME MORE UNSTABLE FARTHER S FROM THE TIDEWATER INTO NC COASTAL PLAIN. ANY STORMS THAT DEVELOP SHOULD BE DIURNAL IN NATURE...CAPABLE OF MARGINALLY SEVERE WIND AND/OR HAIL AND TEND TO WEAKEN BY LATE EVENING. ...NRN ROCKIES INTO NRN/CNTRL HIGH PLAINS... ISOLATED STRONG TO SEVERE STORMS CAPABLE OF HIGH WINDS AND SOME HAIL WILL BE POSSIBLE MONDAY AFTERNOON AND NIGHT WITHIN STEEP LAPSE RATE ENVIRONMENT FROM SWRN MT INTO ERN WY...ERN CO AND WRN KS. A WEAK SHORT WAVE TROUGH UNDER-CUTTING WRN CANADA RIDGE WILL LIKELY BE THE FOCUS FOR AFTERNOON STORMS OVER SWRN INTO S-CNTRL MT. FARTHER S...EITHER FORCING ALONG SWRN EXTENSION OF SYNOPTIC FRONT OR OROGRAPHIC UPSLOPE FLOW APPEAR TO BE THE PRIMARY FORCING MECHANISMS FROM ERN WY INTO ERN CO/WRN KS. RELATIVELY DRY BOUNDARY-LAYER CONDITIONS SHOULD TEND TO LIMIT THE DEGREE OF INSTABILITY AND OVERALL SEVERE THREAT. ..MEAD.. 07/02/2006  From swody2 at goshenarc.org Mon Jul 3 05:15:02 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 03 Jul 2006 01:15:02 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 030514 SWODY2 SPC AC 030513 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1213 AM CDT MON JUL 03 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL/SRN NEW ENGLAND AND MIDDLE ATLANTIC COAST WWD INTO THE OH VALLEY... ...SYNOPSIS... OMEGA BLOCK FROM THE ERN PACIFIC TO ERN CANADA AND THE NERN U.S. WILL PERSIST THROUGH THE DAY TWO PERIOD WITH THE MAIN REGION OF HEIGHT FALLS SPREADING THROUGH THE GREAT LAKES AND NRN OH VALLEY INTO NEW ENGLAND AND THE MIDDLE ATLANTIC STATES. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WILL REMAIN OVER QUEBEC WITH TRAILING COLD FRONT PUSHING EWD THROUGH NEW ENGLAND AND MORE SEWD THROUGH THE SRN GREAT LAKES AND OH VALLEY. ...CNTRL/SRN NEW ENGLAND AND MIDDLE ATLANTIC COAST WWD INTO THE OH VALLEY... MODEST BOUNDARY-LAYER MOISTURE /CHARACTERIZED BY 60S DEWPOINTS/ WILL LARGELY CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS /MLCAPES OF 1000-1500 J/KG/ AS MID-LEVEL LAPSE RATES ARE FORECAST TO REMAIN RATHER WEAK. TSTMS MAY BE ONGOING AT THE ONSET OF THE PERIOD TUESDAY MORNING ALONG OR AHEAD OF COLD FRONT OVER THE ERN GREAT LAKES WWD ACROSS THE OH VALLEY. SOME OF THIS ACTIVITY MAY PERSIST THROUGH THE MORNING...EVENTUALLY INTENSIFYING AS INFLOW AIR MASS DESTABILIZES. ADDITIONAL STORM DEVELOPMENT IS ALSO LIKELY BY AFTERNOON ALONG THE FRONT FROM THE HUDSON VALLEY OR CNTRL NEW ENGLAND WWD ACROSS THE NRN OH VALLEY. VERTICAL WIND PROFILES ARE FORECAST TO REMAIN LARGELY UNIDIRECTIONAL THROUGH THE DURATION OF THE EVENT WITH THE STRONGEST DEEP-LAYER SPEED SHEAR /40-50 KTS IN THE LOWEST 6 KM AGL/ ACROSS NRN PORTION OF SLIGHT RISK AREA. LINE SEGMENTS WITH EMBEDDED BOWING STRUCTURES APPEAR MOST LIKELY WITH THE PRIMARY SEVERE WEATHER HAZARD BEING DAMAGING WINDS. LARGE HAIL WILL ALSO BE POSSIBLE WITH THE MOST INTENSE UPDRAFTS. THE SEVERE THREAT SHOULD END OVER NEW ENGLAND BY EARLY EVENING AS STORMS MOVE OFFSHORE. FARTHER SW...TSTM ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT FROM THE DELMARVA WWD INTO THE SRN OH VALLEY...THOUGH ANY ORGANIZED SEVERE THREAT IS EXPECTED TO DIMINISH BY MID TO LATE EVENING. ...ERN WY INTO WRN PARTS OF SD/NEB... SHORT WAVE TROUGH CURRENTLY LIFTING NEWD INTO ERN ORE/WRN ID IS FORECAST TO MOVE THROUGH MEAN RIDGE DURING THE DAY ONE PERIOD AND THEN SEWD THROUGH THE NRN AND CNTRL HIGH PLAINS TUESDAY INTO TUESDAY EVENING. THIS FEATURE IS LIKELY TO SUPPORT TSTM DEVELOPMENT BY AFTERNOON WITHIN UPSLOPE REGION OVER ERN WY INTO WRN PARTS OF SD/NEB. FORECAST SOUNDINGS INDICATE THAT AIR MASS WILL NOT BE PARTICULARLY UNSTABLE /MLCAPES LESS THAN 1000 J/KG/ OWING TO MARGINAL LOW-LEVEL MOISTURE AND LAPSE RATES. STRONG DIRECTIONAL SHEAR WILL BE SUPPORTIVE OF A FEW ORGANIZED STORMS CAPABLE OF ISOLATED DAMAGING WINDS AND HAIL. THE QUESTIONABLE INSTABILITY PRECLUDES ISSUANCE OF A CATEGORICAL RISK ATTM. ...ERN WA/NERN ORE/ID PNHDL... A STEEP LAPSE RATE ENVIRONMENT IS FORECAST TO DEVELOP ACROSS THE REGION TUESDAY AFTERNOON INTO EVENING WITH MLCAPES INCREASING TO 500-1000 J/KG. FORCING FOR ASCENT ASSOCIATED WITH AN APPROACHING SHORT WAVE TROUGH IS EXPECTED TO OVERSPREAD THE REGION NEAR THE TIME OF PEAK HEATING...LIKELY CONTRIBUTING TO AN INCREASE IN STORM COVERAGE AND INTENSITY. WHILE VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG...THE STEEP LAPSE RATES AND DEEPLY-MIXED BOUNDARY LAYER CONDITIONS INDICATE THE POTENTIAL FOR LOCALLY DAMAGING WINDS AND SOME SEVERE HAIL. ..MEAD.. 07/03/2006  From swody2 at goshenarc.org Mon Jul 3 16:58:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 03 Jul 2006 12:58:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 031656 SWODY2 SPC AC 031655 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CDT MON JUL 03 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND AND THE MID ATLANTIC REGION WWD INTO THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN WY/SWRN SD/WRN NEB... ...SYNOPSIS... HIGH AMPLITUDE FLOW PATTERN IS FORECAST TO PROGRESS SLOWLY EWD ON TUESDAY AS UPPER LOW OVER WRN ONTARIO MOVES TO THE ERN ONTARIO/WRN QUEBEC BORDER...UPSTREAM RIDGE MOVES OVER THE NRN HIGH PLAINS...AND A TROUGH REMAINS OVER THE ERN PACIFIC. AT THE SURFACE A BROAD AREA OF LOW PRESSURE IS FORECAST TO MOVE ACROSS ERN CANADA AND NEW ENGLAND IN ADVANCE OF THE UPPER LOW...WITH A SURFACE COLD FRONT EXPECTED TO MOVE SEWD ACROSS NEW ENGLAND...THE LOWER GREAT LAKES AND MIDDLE MS VALLEY. IN THE WEST...A SLOW MOVING COLD FRONT WILL MOVE INTO THE ERN PARTS OF WA AND OREGON. ...NERN STATES ACROSS THE OH VALLEY... MODELS INDICATE SEVERAL AREAS OF CONVECTION WILL BE OCCURRING DURING THE MORNING ALONG/AHEAD OF THE COLD FRONT FROM PARTS OF NY/PA WSWWD ACROSS THE MID MS VALLEY. CLOUD COVER SPREADING DOWNSTREAM FROM THIS ACTIVITY COUPLED WITH MODEST LAPSE RATES IS LIKELY TO INHIBIT STRONG DESTABILIZATION DURING THE DAY AHEAD OF THE FRONT...BUT DEW POINTS OF 65-70F AND LOCAL AREAS OF ENHANCED DIURNAL HEATING WILL CONTRIBUTE TO MAXIMUM MLCAPE VALUES OF 1000-1500 J/KG DURING THE AFTERNOON. THIS SUGGESTS INTENSIFICATION OF THUNDERSTORMS WILL OCCUR AS DYNAMIC FORCING FOR LARGE SCALE ASCENT IS ENHANCED BY DIVERGENCE ALOFT ASSOCIATED WITH RIGHT ENTRANCE REGION WITHIN UPPER LEVEL JET STREAK MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND DURING THE AFTERNOON AND EVENING. VERTICAL SHEAR PROFILES ARE FORECAST TO BE PRIMARILY UNIDIRECTIONAL...WITH STRONGEST DEEP LAYER SHEAR OF 35-45 KT IN THE LOWEST 6 KM EXPECTED OVER NRN PARTS OF THE SLIGHT RISK AREA FROM THE LOWER GREAT LAKES INTO NRN NEW ENGLAND. THIS WILL SUPPORT DEVELOPMENT OF MULTIPLE EMBEDDED LINE SEGMENTS WITH OCCASIONAL BOW ECHOES AND ATTENDANT THREAT FOR DAMAGING WIND GUSTS...ALONG WITH HAIL FROM STRONGER CELLS. ORGANIZED SEVERE POTENTIAL IS EXPECTED TO GRADUALLY DIMINISH WITH SWD EXTENT ACROSS THE OH VALLEY AND MIDDLE ATLANTIC REGION WHERE WINDS ALOFT/VERTICAL SHEAR ARE EXPECTED TO DECREASE. ...ERN WY INTO WRN NEB... WEAK UPSLOPE LOW LEVEL WINDS ARE FORECAST TO DEVELOP OVER PARTS OF THE HIGH PLAINS TOMORROW AS SURFACE HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. THIS WILL RESULT IN SURFACE DEWPOINTS IN THE 50S SPREADING INTO THIS REGION...AND ALTHOUGH MID LEVEL LAPSE RATES ARE EXPECTED TO BE MODEST AS HEIGHTS RISE OVER THE ROCKIES...ENVIRONMENT WILL BECOME UNSTABLE WITH MLCAPE OF AROUND 1000 J/KG DURING THE AFTERNOON. THUNDERSTORMS SHOULD DEVELOP DURING THE AFTERNOON OVER THE HIGHER TERRAIN OF WY AND SWRN SD AND MOVE SEWD INTO THE HIGH PLAINS ALONG THE SRN EDGE OF 20-25 KT NWLY MID LEVEL FLOW. STRONG DIRECTIONAL SHEAR WITH HEIGHT SHOULD BE SUFFICIENT TO ENHANCE STORM ORGANIZATION AND SUPPORT DEVELOPMENT OF A FEW SUPERCELLS WITH LARGE HAIL AND STRONG WIND GUSTS DURING THE LATE AFTERNOON AND EVENING. ...NRN INTERMOUNTAIN REGION... STEEP LAPSE RATES ARE EXPECTED TO PERSIST ACROSS THE AREA AS PRIMARY UPPER TROUGH REMAINS OVER THE ERN PACIFIC. PLUME OF MID LEVEL MOISTURE IS EXPECTED TO BE EMBEDDED WITHIN SSWLY FLOW ALOFT...SUGGESTING POTENTIAL FOR A FEW HIGHER-BASED THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON AND EVENING. STEEP LAPSE RATES AND DEEP WELL-MIXED LAYER SUGGESTS THREAT FOR ISOLATED MICROBURSTS AND POSSIBLE HAIL...BUT RELATIVELY WEAK DEEP LAYER SHEAR SHOULD LIMIT OVERALL SEVERE THREAT. ..WEISS.. 07/03/2006  From swody2 at goshenarc.org Tue Jul 4 05:34:30 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 04 Jul 2006 01:34:30 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040533 SWODY2 SPC AC 040532 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 AM CDT TUE JUL 04 2006 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM FAR SRN NEW ENGLAND/DE RIVER VALLEY SWD THROUGH THE TIDEWATER AND CNTRL APPALACHIANS... ...SYNOPSIS... AMPLIFICATION OF ERN CONUS TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS EMBEDDED SHORT WAVE TROUGH INITIALLY OVER THE GREAT LAKES DIGS SEWD INTO THE CNTRL APPALACHIANS. IN THE W...SHORT WAVE TROUGH OVER NV/UT WEDNESDAY MORNING WILL LIFT NEWD INTO THE NRN ROCKIES WHILE IMPULSE ROTATING THROUGH BASE OF ERN PACIFIC TROUGH EJECTS NEWD INTO THE PACIFIC NW. IN THE LOW-LEVELS...COLD FRONT ASSOCIATED WITH THE ERN U.S. TROUGH WILL PUSH EWD THROUGH NEW ENGLAND AND MORE SEWD THROUGH THE MIDDLE ATLANTIC STATES...DELMARVA...CNTRL APPALACHIANS AND TN VALLEY. THIS FRONT WILL BE THE PRIMARY FOCUS FOR STRONG TO SEVERE STORMS THROUGH THE FORECAST PERIOD. ...FAR SRN NEW ENGLAND/DE RIVER VALLEY SWD THROUGH THE TIDEWATER AND CNTRL APPALACHIANS... CURRENT SURFACE OBSERVATIONS AND MODEL GUIDANCE INDICATE THAT A RELATIVELY MOIST LOW-LEVEL AIR MASS /DEWPOINTS IN THE 60S TO LOWER 70S/ WILL EXIST S OF COLD FRONT. THIS MOISTURE COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO AFTERNOON MLCAPES FROM AROUND 1000 J/KG OVER THE NRN PART OF THE SLIGHT RISK AREA TO 2000-2500 J/KG OVER THE SERN VA/NC COASTAL PLAIN. TSTMS WILL LIKELY PERSIST THROUGH MUCH OF THE PERIOD ALONG AND AHEAD OF THE FRONT OWING TO A WEAKLY CAPPED ENVIRONMENT. THE GREATEST SEVERE STORM THREAT IS EXPECTED DURING THE AFTERNOON INTO EVENING HOURS FROM THE DELMARVA/TIDEWATER REGION INTO THE VA/NC PIEDMONT AS SURFACE FRONT ENCOUNTERS STRONGEST INSTABILITY. LARGELY UNDIRECTIONAL WIND FIELDS AND FORCED ASCENT ALONG THE FRONT INDICATE THE LIKELIHOOD OF LINE SEGMENTS CAPABLE OF DAMAGING WINDS AND SOME LARGE HAIL. ...NRN ROCKIES... FORCING FOR ASCENT AHEAD OF SHORT WAVE TROUGHS LIFTING NEWD FROM THE GREAT BASIN AND ALONG THE PACIFIC NW COAST ARE EXPECTED TO CONTRIBUTE TO AN INCREASE IN TSTM COVERAGE THROUGH THE AFTERNOON AND EVENING FROM ERN PORTIONS OF WA/ORE THROUGH ID INTO WRN MT/WY. DEWPOINTS WILL REMAIN LARGELY IN THE MID 40S TO MID 50S...THOUGH THE PRESENCE OF STEEP LAPSE RATES WILL SUPPORT MLCAPES OF AROUND 1000 J/KG. THE STRONGEST MID AND HIGH-LEVEL WIND FIELDS AND RESULTING VERTICAL SHEAR ARE FORECAST TO REMAIN W OF MAIN INSTABILITY AXIS. HOWEVER...THE STEEP LAPSE RATES AND 25-30 KTS OF SHEAR THROUGH THE LOWEST 6 KM WILL SUPPORT A FEW ORGANIZED STORMS CAPABLE OF SEVERE HAIL AND LOCALLY DAMAGING WINDS. ..MEAD.. 07/04/2006  From swody2 at goshenarc.org Mon Jul 10 06:03:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 10 Jul 2006 02:03:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100602 SWODY2 SPC AC 100601 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0101 AM CDT MON JUL 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SERN CO INTO THE TX PANHANDLE AND EWD INTO SWRN KS/NWRN OK... ...SYNOPSIS... STRONGEST BELT OF WESTERLIES IS EXPECTED TO REMAIN LOCATED FROM THE PACIFIC NORTHWEST TO NORTH OF THE INTERNATIONAL BORDER INTO CENTRAL AND NERN CANADA. SOUTH OF THIS STRONGER FLOW...A RATHER BROAD MID/UPPER LEVEL TROUGH WILL MOVE SLOWLY ENEWD FROM THE CENTRAL/NRN PLAINS TO THE UPPER MS VALLEY/GREAT LAKES REGION. COMPACT SHORT WAVE TROUGH...CURRENTLY TRACKING SEWD ACROSS THE GREAT LAKES REGION...IS PROGGED TO BE LOCATED OVER ERN NY/PA AT 12Z TUESDAY AND SHOULD WEAKEN AS IT MOVES ACROSS NEW ENGLAND DURING DAY 2. ...SERN CO INTO TX PANHANDLE EWD TO SWRN KS/NWRN OK... THE SRN EXTENT OF A SURFACE TROUGH IS EXPECTED TO REMAIN NEARLY STATIONARY FROM THE TX PANHANDLE ENEWD INTO SWRN KS. STRONG SURFACE HEATING ALONG THIS BOUNDARY WHERE SURFACE DEWPOINTS SHOULD REMAIN IN THE 60S COMBINED WITH STEEP MID LEVEL LAPSE RATES WILL RESULT IN MODERATE INSTABILITY. DESPITE WNWLY MID LEVEL WINDS GENERALLY AT 20-25 KT...ELY LOW LEVEL WINDS LOCATED BENEATH THE MODEST FLOW ALOFT SHOULD SUPPORT 30-35 KT OF DEEP LAYER SHEAR FOR STORM ORGANIZATION. THUNDERSTORMS SHOULD DEVELOP ALONG THIS BOUNDARY TUESDAY AFTERNOON WITH THE POTENTIAL FOR DAMAGING WINDS GIVEN LARGE SURFACE DEWPOINT DEPRESSIONS...AND ALSO A THREAT FOR HAIL DUE TO STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR. ...S CENTRAL KS/N CENTRAL OK NEWD TO MID MS VALLEY/IND... MODELS CONTINUE TO DIFFER IN THE AMPLIFICATION OF THE MID/UPPER LEVEL TROUGH MOVING ACROSS THIS REGION ON TUESDAY...AND THUS RESULTING IN UNCERTAINTY WITH THE STRENGTH OF THE WLY MID LEVEL WINDS AND DEEP LAYER SHEAR. A WEAK SURFACE LOW IS EXPECTED TO BE LOCATED OVER SRN IA/NRN MO AT 12Z TUESDAY WITH A TROUGH EXTENDING SWWD ACROSS KS INTO THE SRN HIGH PLAINS. THE NRN EXTENT OF THIS BOUNDARY IS EXPECTED TO MOVE EWD ACROSS THE MID MS VALLEY REACHING THE LOWER OH VALLEY...WHILE THE SURFACE LOW MOVES INTO THE SRN GREAT LAKES REGION BY 12Z WEDNESDAY. THE SRN EXTENT OF THE SURFACE BOUNDARY IS EXPECTED TO MOVE SLOWLY SWD AND SHOULD STALL ALONG THE OK/KS BORDER INTO SRN MO. THUNDERSTORMS SHOULD BE ONGOING AT THE START OF DAY 2 ACROSS PARTS OF THE CENTRAL PLAINS TO THE MID MS VALLEY WITHIN WAA REGIME ALONG AXIS OF SWLY LLJ. AIR MASS ALONG/S OF ONGOING ACTIVITY FROM SRN KS/NRN OK INTO PARTS OF THE MID MS VALLEY SHOULD BECOME MODERATELY UNSTABLE TUESDAY AFTERNOON. LESS INSTABILITY IS EXPECTED WITH EWD EXTENT INTO IL/IND DUE TO WEAKER LAPSE RATES AND THE POTENTIAL FOR CONVECTIVE CLOUDINESS LIMITING SURFACE HEATING. GIVEN UNCERTAINTIES IN THE STRENGTH OF DEEP LAYER SHEAR...THIS OUTLOOK WILL MAINTAIN LOW SEVERE PROBABILITIES EAST OF THE SLIGHT RISK AREA FOR THE POTENTIAL OF ISOLATED STRONG WIND GUSTS AND/OR HAIL. A SLIGHT RISK AREA MAY BE REQUIRED IN LATER OUTLOOKS FOR PARTS OF THIS REGION...IF MODELS AND/OR OBSERVATIONAL DATA SUGGEST STRONGER WLY MID LEVEL WINDS/DEEP LAYER SHEAR. ...DELMARVA REGION TO NEW ENGLAND... IN THE LOW LEVELS...A WEAK SURFACE TROUGH WILL MOVE SLOWLY EWD ACROSS ERN NY/PA INTO NEW ENGLAND AS ASSOCIATED MID LEVEL IMPULSE DE-AMPLIFIES THIS FORECAST PERIOD. POCKETS OF SURFACE HEATING EAST OF THE SURFACE TROUGH COMBINED WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S SHOULD RESULT IN MODERATE INSTABILITY FROM THE DELMARVA REGION NEWD INTO MUCH OF NEW ENGLAND. WEAK MID LEVEL LAPSE RATES AND GENERALLY WEAK DEEP LAYER SHEAR ARE EXPECTED TO LIMIT THE SEVERE POTENTIAL. HOWEVER...A FEW STORMS MAY BECOME STRONG ENOUGH TO PRODUCE AN ISOLATED THREAT OF HAIL/STRONG WIND GUSTS THROUGH TUESDAY AFTERNOON INTO THE EARLY EVENING. ..PETERS.. 07/10/2006  From swody2 at goshenarc.org Mon Jul 10 17:33:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 10 Jul 2006 13:33:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101730 SWODY2 SPC AC 101729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT MON JUL 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE ACROSS PARTS OF THE MID MS/LWR OH VLY.... ...THERE IS A SLGT RISK OF SVR TSTMS LATE TUE AFTN/EVE ACROSS PARTS OF THE S CNTRL HIGH PLAINS.... MODELS INDICATE STRONGER WESTERLIES WITH EMBEDDED SHORT WAVES WILL PERSIST IN A BROAD CYCLONIC BELT FROM THE NORTHEAST PACIFIC THROUGH THE PACIFIC NORTHWEST/NORTHERN ROCKIES INTO THE CENTRAL AND EASTERN CANADIAN PROVINCES. MID/UPPER FLOW ACROSS MUCH OF THE REST OF THE U.S. WILL REMAIN WEAK TUESDAY...BUT RIDGING WILL REMAIN SUPPRESSED AS BROAD UPPER TROUGH IN THE SUBTROPICAL STREAM SHIFTS EASTWARD ACROSS THE MID MISSISSIPPI/OHIO VALLEYS AND GREAT LAKES REGION. DOWNSTREAM SHORT WAVE TROUGH IS PROGGED TO SLOWLY PROGRESS OFF THE NORTH ATLANTIC COAST...WHILE WEAKER IMPULSES UPSTREAM MIGRATE ACROSS PARTS OF THE SOUTHERN PLATEAU/ROCKIES AND HIGH PLAINS. UNCERTAINTIES CONCERNING LOCATION OF PRIMARY CONVECTIVE DEVELOPMENT ARE SIZABLE FOR THIS FORECAST PERIOD...BUT WEAK FRONTAL ZONE ASSOCIATED WITH THE SOUTHERN/SUBTROPICAL STREAMS IS EXPECTED TO PROVIDE THE FOCUS FOR THUNDERSTORM ACTIVITY. ...NEW ENGLAND COASTAL AREAS INTO NRN MID ATLANTIC REGION... POTENTIAL FOR AN ORGANIZED CLUSTER OF STORMS SEEMS LOW...BUT WEAKENING UPPER TROUGH MAY CONTRIBUTE TO SUFFICIENT FORCING/DESTABILIZATION FOR SCATTERED THUNDERSTORMS BY EARLY TUESDAY AFTERNOON. EXPECTED MIXED LAYER CAPE UP TO AROUND 1500 J/KG BY PEAK HEATING IS NOT PARTICULARLY STRONG. HOWEVER...30+ KT SOUTHWESTERLY/WESTERLY MID-LEVEL FLOW COULD CONTRIBUTE TO FAVORABLE SHEAR/STORM MOTIONS FOR ISOLATED STORMS APPROACHING OR BRIEFLY EXCEEDING SEVERE CRITERIA BEFORE STORMS DIMINISH TUESDAY EVENING WITH LOSS OF INSOLATION. ...MID MISSISSIPPI/LOWER OHIO VALLEY... MAGNITUDE OF DESTABILIZATION IS UNCERTAIN DUE TO LIKELIHOOD OF CONSIDERABLE CLOUD COVER AND WEAK LAPSE RATES. HOWEVER...BOUNDARY LAYER DEW POINTS AROUND 70F WILL STILL PROBABLY BE SUPPORTIVE OF MIXED LAYER CAPE AT OR ABOVE 1000 J/KG WITH AT LEAST SOME INSOLATION. AND...MODELS SUGGEST A BELT OF 30-40 KT WEST SOUTHWESTERLY LOWER/MID TROPOSPHERIC FLOW WITH AN IMPULSE ACCOMPANYING UPPER TROUGH...WHICH MAY PROVIDE SUFFICIENT FORCING FOR AN ORGANIZED CONVECTIVE CLUSTER. THERMODYNAMIC ENVIRONMENT DOES NOT APPEAR LIKELY TO BE SUPPORTIVE OF LARGE HAIL...BUT POTENTIAL EXISTS FOR A SWATH OF DAMAGING WINDS APPROACHING OR EXCEEDING SEVERE CRITERIA...PARTICULARLY AS ACTIVITY PROGRESSES ACROSS ILLINOIS/INDIANA DURING THE PEAK HEATING HOURS. ...SOUTHERN CENTRAL PLAINS... MID/UPPER FORCING FOR CONVECTIVE DEVELOPMENT IS UNCERTAIN...BUT SURFACE LOW NEAR INTERSECTION OF FRONT/LEE TROUGH ACROSS THE TEXAS PANHANDLE REGION COULD PROVIDE THE FOCUS FOR CONVECTIVE DEVELOPMENT LATE TUESDAY AFTERNOON. ACTIVITY WILL PROBABLY INITIATE AS CONVECTIVE TEMPERATURES ARE REACHED IN ENVIRONMENT WITH MIXED LAYER CAPE OF 1000-2000 J/KG. STRENGTH OF DEEP LAYER SHEAR IS IN QUESTION...BUT FAVORABLE LOW-LEVEL CONVERGENCE/WARM ADVECTION COULD AID CONSOLIDATION OF ACTIVITY INTO A LARGE CONVECTIVE CLUSTER. AND...STEEP LAPSE RATES/HOT BOUNDARY LAYER WILL BE CONDUCIVE FOR A FEW DOWNBURSTS AND STRONG GUSTY WINDS ALONG OUTFLOWS. SOME HAIL IS ALSO POSSIBLE IN STRONGER CELLS...BEFORE THEY DIMINISH IN INTENSITY TUESDAY EVENING. ..KERR.. 07/10/2006  From swody2 at goshenarc.org Tue Jul 11 06:14:16 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 11 Jul 2006 02:14:16 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110610 SWODY2 SPC AC 110609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT TUE JUL 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL APPALACHIANS INTO SWRN NEW ENGLAND... ...SYNOPSIS... BROAD POSITIVELY TILTED MID LEVEL TROUGH IS EXPECTED TO MOVE EWD FROM THE GREAT LAKES/MID MS VALLEY ACROSS THE OH VALLEY AND TOWARD NEW ENGLAND. MEANWHILE...PRIMARY BELT OF WESTERLIES IS EXPECTED TO EXTEND FROM THE PACIFIC NW INTO SRN AND ERN CANADA. MODELS REMAIN DIFFERENT WITH THE TIMING OF A SHORT WAVE TROUGH EXPECTED TO TRANSLATE ENEWD ACROSS THE NRN HIGH PLAINS TO SOUTH CENTRAL CANADA DURING DAY 2 FORECAST PERIOD. NAM/NAMKF INDICATED A MID LEVEL SHORT WAVE TROUGH AND ATTENDANT SURFACE LOW APPROACHING THE E/SE COAST OF FL WEDNESDAY AFTERNOON... WITH THIS SYSTEM THEN TURNING NWD ALONG THE N FL COAST WEDNESDAY NIGHT. IF THIS SYSTEM DOES DEVELOP AS FORECAST BY THE NAM/NAMKF... AND MOVES CLOSER TO THE COAST THAN CURRENTLY FORECAST ENHANCING LOW LEVEL DIRECTIONAL SHEAR...THEN SEVERE PROBABILITIES MAY BE REQUIRED IN LATER OUTLOOKS. ...SRN NEW ENGLAND TO CENTRAL APPALACHIANS AND OH VALLEY... IN THE LOW LEVELS...A SURFACE LOW ASSOCIATED WITH THE BROAD MID LEVEL TROUGH IS EXPECTED TO BE LOCATED OVER THE SRN GREAT LAKES REGION AT 12Z WEDNESDAY. THIS LOW IS FORECAST TO TRACK EWD REACHING SRN NEW ENGLAND BY 12Z THURSDAY...WHILE THE TRAILING SURFACE BOUNDARY SPREADS EWD ACROSS NY/PA AND SWD INTO THE OH VALLEY. THUNDERSTORMS ARE EXPECTED TO BE ONGOING ALONG/AHEAD OF THE SURFACE TROUGH AT 12Z WEDNESDAY FROM THE LOWER GREAT LAKES REGION SWWD THROUGH THE OH VALLEY IN ASSOCIATION WITH WAA ALONG A 40-50 KT SWLY LLJ AXIS. AIR MASS DOWNSTREAM OF THIS INITIAL ACTIVITY IS EXPECTED TO DESTABILIZE GIVEN RICH MOISTURE /SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70/ ADVECTION AND SURFACE HEATING ESPECIALLY ACROSS THE SRN HALF OF THE SLIGHT RISK AREA. WEAK MID LEVEL LAPSE RATES SHOULD LIMIT THE DEVELOPMENT OF STRONGER INSTABILITY WITH MLCAPE RANGING FROM 500-1000 J/KG. DESPITE POTENTIAL FOR MARGINAL INSTABILITY...STRONG /40-50 KT/ WSWLY LOW-MID LEVEL WINDS SHOULD COMPENSATE FOR THIS LIMITING FACTOR...AND SUPPORT A THREAT FOR DAMAGING WINDS AS ONGOING STORMS AND/OR NEW LINE SEGMENTS DEVELOP EWD ACROSS THE SLIGHT RISK AREA. STRONG DEEP LAYER SHEAR ALSO SUGGESTS SUPERCELLS WILL BE POSSIBLE WITH STRONG LOW LEVEL SHEAR VALUES SUPPORTING A TORNADO THREAT...ESPECIALLY ACROSS NRN MD/ERN PA TO SERN NY WHERE INSTABILITY SHOULD BE MAXIMIZED AND MLCAPE POTENTIALLY REACH 1500 J/KG. FARTHER SOUTHWEST THROUGH THE OH VALLEY...THE AIR MASS SHOULD BECOME MODERATELY UNSTABLE SOUTH OF INITIAL CONVECTIVE ACTIVITY SUPPORTING NEW THUNDERSTORMS THROUGH DAY 2. WEAKER DEEP LAYER SHEAR WITH SWWD EXTENT IS EXPECTED TO LIMIT THE SEVERE WEATHER THREAT ACROSS THE OH VALLEY. ...PLAINS STATES... SLY LOW LEVEL FLOW ACROSS THE PLAINS STATES IS EXPECTED TO ADVECT MOISTURE NWD...WHILE STRONG SURFACE HEATING AND DEEP BOUNDARY LAYER MIXING WITHIN THIS AIR MASS SHOULD RESULT IN LARGE SURFACE TEMPERATURE/DEWPOINT SPREADS BY PEAK HEATING WEDNESDAY AFTERNOON. STEEP LAPSE RATES WILL SUPPORT MODERATE INSTABILITY /MLCAPE 1500-2500 J/KG/ DEVELOPING FROM OK AND TX PANHANDLE NWD TO THE DAKOTAS. IN ADDITION TO MODEL DIFFERENCES WITH THE TIMING OF THE MID LEVEL IMPULSE TO AFFECT THE NRN PLAINS...THERE IS LARGE MODEL SPREAD IN THE SPEED OF WLY MID LEVEL FLOW EXPECTED ACROSS THE CENTRAL/SRN PLAINS. DESPITE THESE DIFFERENCES...THIS OUTLOOK WILL INDICATE LOW SEVERE PROBABILITIES...GIVEN THAT EVEN WEAK DEEP LAYER SHEAR /20-25 KT/ WITHIN A MODERATELY UNSTABLE ENVIRONMENT WILL SUPPORT A FEW SEVERE STORMS. ACTIVITY SHOULD BE FOCUSED ALONG THE LEE TROUGH WHICH WILL MOVE EWD INTO THE NRN PLAINS BY LATER IN THE FORECAST PERIOD. A FEW SEVERE STORMS WILL ALSO BE POSSIBLE ALONG A TRAILING COLD FRONT INTO SRN MT WHERE DEEP LAYER SHEAR WILL BE SUFFICIENT FOR ORGANIZED STORMS...BUT INSTABILITY MAY BE WEAKER. ..PETERS.. 07/11/2006  From swody2 at goshenarc.org Wed Jul 12 17:36:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 12 Jul 2006 13:36:51 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121735 SWODY2 SPC AC 121734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT WED JUL 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN AND CENTRAL PLAINS... ...SYNOPSIS... UPPER RIDGE WILL REMAIN OVER THE SWRN U.S. THIS PERIOD...WHILE SEVERAL UPPER DISTURBANCES MOVE W-E ACROSS THE CENTRAL AND NRN CONUS WITH BELT OF WLYS N OF UPPER RIDGE. AT THE SURFACE...A COLD FRONT WILL SHIFT EWD ACROSS THE NORTHEAST AHEAD OF A FAIRLY PRONOUNCED UPPER TROUGH...WHILE A SECOND FRONT/TROUGH CROSSES THE PLAINS AHEAD OF A SECOND SHORT-WAVE FEATURE. ...THE PLAINS... STEEP LAPSE RATES ABOVE A MOIST BOUNDARY LAYER SHOULD RESULT IN MODERATE TO STRONG INSTABILITY BY AFTERNOON ACROSS THE PLAINS. AS MORE PRONOUNCED SHORT-WAVE TROUGH ENTERS THE PLAINS IN THE WAKE OF EARLIER FEATURE...STORMS SHOULD INITIATE ALONG SURFACE FRONT/LEE TROUGH BY AFTERNOON. THOUGH ENHANCED FLOW ALOFT IS FORECAST ALONG WRN FRINGE OF SHORT-WAVE FEATURE...IT APPEARS ATTM THAT STRONGEST FLOW WILL REMAIN BEHIND THE SURFACE BOUNDARY AND ASSOCIATED ZONE OF CONVECTIVE INITIATION. NONETHELESS...LOW-LEVEL VEERING SHOULD YIELD SUFFICIENT SHEAR -- GIVEN DEGREE OF INSTABILITY -- FOR MULTICELL AND/OR WEAKLY-ROTATING STORMS. ALONG WITH POTENTIAL FOR LARGE HAIL GIVEN DEGREE OF INSTABILITY...LOCALLY-DAMAGING WINDS WILL ALSO BE POSSIBLE DUE TO POTENTIAL FOR LOW-LEVEL EVAPORATIVE COOLING GIVEN SURFACE TEMPERATURES FORECAST TO CLIMB INTO THE 90S. STORMS SHOULD CONTINUE/SHIFT SEWD ACROSS THE PLAINS OVERNIGHT AS LOW-LEVEL JET VEERS -- WITH SOME SEVERE THREAT POSSIBLY LINGERING THROUGH THE END OF THE PERIOD. ...SRN NEW ENGLAND/THE MID-ATLANTIC REGION... MARGINAL AIRMASS DESTABILIZATION IS FORECAST ALONG EWD-MOVING COLD FRONT DURING THE AFTERNOON...AS UPPER SHORT-WAVE TROUGH CROSSES THE NERN CONUS. ATTM...IT APPEARS THE STRONGER FLOW AND GREATER LOW-LEVEL CONVERGENCE ALONG FRONT WILL EXIST ACROSS SRN NEW ENGLAND -- WHERE INSTABILITY SHOULD BE WEAKER /AOB 500 J/KG MEAN-LAYER CAPE/. FURTHER S INTO THE MID-ATLANTIC REGION...WEAKER WSWLY FLOW THROUGH THE LOWER TROPOSPHERE -- MORE PARALLEL TO SURFACE FRONT -- SUGGESTS WEAKER LOW-LEVEL CONVERGENCE AND WEAKER SHEAR DESPITE SOMEWHAT MORE UNSTABLE AIRMASS. THEREFORE -- THOUGH A LIMITED SEVERE THREAT APPEARS POSSIBLE ALONG THE SURFACE BOUNDARY FROM SRN NEW ENGLAND SWWD INTO SWRN VA...OVERALL SEVERE POTENTIAL APPEARS TO BE BELOW SLIGHT RISK THRESHOLD ATTM. ...OZARKS INTO THE MID MS VALLEY... THUNDERSTORMS ARE FORECAST TO REDEVELOP ALONG REMNANT BAROCLINIC ZONE -- WHICH SHOULD EXTEND FROM THE TN VALLEY REGION WWD INTO THE CENTRAL PLAINS...AS AIRMASS BECOMES MODERATELY UNSTABLE DURING THE AFTERNOON. THOUGH DEEP-LAYER WILL REMAIN WEAK ACROSS THIS REGION...A FEW PULSE-TYPE SEVERE STORMS CAPABLE OF HAIL OR BRIEFLY-DAMAGING WIND GUSTS WILL BE POSSIBLE. ..GOSS.. 07/12/2006  From swody2 at goshenarc.org Thu Jul 13 06:11:06 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 13 Jul 2006 02:11:06 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130608 SWODY2 SPC AC 130607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT THU JUL 13 2006 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SHORT WAVE TROUGH OVER THE UPPER/MID MS VALLEY AND EXTENDING NWD INTO CANADA AT 12Z FRIDAY IS PROGGED TO DE-AMPLIFY AS IT TRACKS EWD ACROSS THE GREAT LAKES REGION AND ONTARIO...WITH A RIDGE BUILDING NNEWD IN ITS WAKE. THE SRN EXTENT OF THIS TROUGH SHOULD BECOME DETACHED FROM THE PRIMARY BELT OF WESTERLIES...WHICH WILL BE FARTHER TO THE NORTH...AND MOVE SLOWLY SEWD OVER THE MID MS VALLEY. IN THE NORTHEAST...A WEAK SHORT WAVE TROUGH IS EXPECTED TO TRACK SEWD ACROSS NRN NEW ENGLAND WITHIN MODERATE NWLY FLOW REGIME DURING THE FIRST HALF OF DAY 2. ...MAINE... A SURFACE TROUGH IS EXPECTED TO MOVE SEWD ACROSS MAINE FRIDAY MORNING/EARLY AFTERNOON. DESPITE SURFACE HEATING AHEAD OF THIS BOUNDARY COMBINED WITH RICH MOISTURE /SURFACE DEWPOINTS IN THE 60S/...WEAK LAPSE RATES SUGGEST INSTABILITY SHOULD REMAIN MARGINAL /MUCAPE GENERALLY BELOW 1000 J/KG/. ASCENT AHEAD OF THE WEAK MID LEVEL SHORT WAVE TROUGH WILL SUPPORT THUNDERSTORMS MAINLY OVER SRN/ERN MAINE AS THE SURFACE BOUNDARY MOVES SEWD DURING THE LATE MORNING INTO THE AFTERNOON. DEEP LAYER SHEAR IS EXPECTED TO BE SUFFICIENT FOR A FEW ORGANIZED STORMS GIVEN 30-40 KT OF NWLY MID LEVEL FLOW. ...PARTS OF CENTRAL/NRN WI INTO WRN U.P. OF MI... ALTHOUGH HEIGHTS WILL BE RISING ACROSS THIS REGION ON FRIDAY... RESIDUAL SURFACE MOISTURE AND SURFACE HEATING ARE EXPECTED TO RESULT IN MODERATE INSTABILITY ACROSS PARTS OF WI INTO THE WRN U.P. OF MI. WEAK LOW LEVEL WAA ACROSS THIS REGION FRIDAY AFTERNOON SHOULD SUPPORT A FEW THUNDERSTORMS. MODERATE NWLY FLOW /30 KT/ SUGGESTS DEEP LAYER SHEAR WILL BE SUFFICIENT FOR STORMS TO BECOME ORGANIZED...WITH AN ATTENDANT THREAT OF ISOLATED HAIL AND/ OR STRONG WIND GUSTS. ...PARTS OF CENTRAL/NORTH CENTRAL MT... A SHORT WAVE TROUGH IS EXPECTED TO TRACK ENEWD FROM THE PACIFIC NORTHWEST GRAZING NRN MT DURING THE LATE AFTERNOON INTO THE EVENING. COLD FRONT ASSOCIATED WITH THIS MID LEVEL TROUGH SHOULD MOVE INTO CENTRAL/NRN MT BY 15/00Z. ALTHOUGH LOW LEVELS WILL BE RATHER DRY... POINT FORECAST SOUNDINGS SUGGEST STEEP MID LAPSE RATES WILL RESULT IN MARGINAL INSTABILITY. STRONG SWLY MID LEVEL WINDS /50-60 KT/ AND THE LIKELIHOOD FOR A DEEP WELL MIXED BOUNDARY LAYER WITH LARGE SURFACE TEMPERATURE/DEWPOINT SPREADS...ANY STORMS THAT DEVELOP INTO THE EVENING MAY PRODUCE STRONG WIND GUSTS. ISOLATED HAIL WILL ALSO BE POSSIBLE...GIVEN STEEP LAPSE RATES AND STRONG DEEP LAYER SHEAR. ..PETERS.. 07/13/2006  From swody2 at goshenarc.org Thu Jul 13 17:50:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 13 Jul 2006 13:50:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131748 SWODY2 SPC AC 131746 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 PM CDT THU JUL 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID/LOWER OH VALLEY AND VICINITY... ...SYNOPSIS... LARGE UPPER HIGH WILL PREVAIL ACROSS THE WRN CONUS...WHILE A SHORT-WAVE TROUGH WILL MOVE EWD ACROSS THE MID AND UPPER MS/OH VALLEYS AND GREAT LAKES AND SWD ACROSS THE PLAINS ON ERN PERIPHERY OF THE RIDGE. MEANWHILE...SMALLER-SCALE DISTURBANCES SHOULD MOVE SEWD ACROSS THE NORTHEAST WITHIN NWLY FLOW REGIME. MAIN SURFACE FEATURE WILL BE A COMBINATION SURFACE FRONT/CONVECTIVE OUTFLOW BOUNDARY AHEAD OF SHORT-WAVE TROUGH CROSSING THE CENTRAL CONUS. THOUGH EXACT LOCATION OF THIS BOUNDARY WILL DEPEND UPON LOCATION AND INTENSITY OF ONGOING STORMS...THIS FEATURE SHOULD MOVE EWD ACROSS THE MIDWEST...SEWD ACROSS THE MID MS VALLEY...AND SWD ACROSS THE SRN PLAINS THROUGH THE PERIOD. ...MID AND LOWER OH/MID MS VALLEY REGIONS... UPPER SHORT-WAVE TROUGH IS FORECAST TO MOVE EWD ACROSS THE MS/OH VALLEYS AND GREAT LAKES REGION THIS PERIOD...AFFECTING AREAS AS FAR S AS THE TN VALLEY. THOUGH ASSOCIATED COLD FRONT SHOULD BE WEAK...POTENTIAL FOR A STRONGER SURFACE BOUNDARY EXISTS DEPENDING UPON THE EVOLUTION OF CONVECTION AND ASSOCIATED OUTFLOW LATE IN THE DAY 1 PERIOD. IN ANY CASE...MOIST AIRMASS WILL BE IN PLACE ACROSS THE REGION...WITH MODELS INDICATING A BELT OF ENHANCED/ROUGHLY UNIDIRECTIONAL LOWER TO MID-LEVEL FLOW /AROUND 30 KT/ ACROSS THE LOWER OH VALLEY REGION. SCENARIO IS COMPLICATED GIVEN CONVECTION WHICH SHOULD BE ONGOING...BUT ATTM IT APPEARS THAT SUFFICIENT INSTABILITY WILL DEVELOP AHEAD OF FRONT/CONVECTIVE OUTFLOW SOMEWHERE WITHIN A ZONE FROM INDIANA/WRN OH INTO CENTRAL AND WRN KY AND PERHAPS SRN IL/SERN MO/NRN TN. THIS COMBINED WITH MODERATE WLY FLOW SUGGESTS AN ENHANCED POTENTIAL FOR DAMAGING WINDS...AND THUS WILL INTRODUCE A SLIGHT RISK ACROSS THIS REGION. FURTHER N INTO THE UPPER GREAT LAKES...NW ACROSS IL/IA...AND SW INTO SRN MO/NRN AR...SCENARIO REMAINS MORE COMPLEX DUE TO LIKELIHOOD FOR ONGOING CONVECTION. WILL INCLUDE A LARGE 5% SEVERE THREAT AREA THIS FORECAST TO ACCOUNT FOR SEVERE POTENTIAL...WITH ANY POSSIBILITY FOR GREATER SEVERE THREAT IN THESE AREAS LARGELY DEPENDENT UPON EVOLUTION OF DAY 1 CONVECTION. ...SRN PLAINS WWD INTO ERN NM... STRONG HEATING IS FORECAST S OF OUTFLOW-REINFORCED SURFACE BOUNDARY WHICH SHOULD BE MOVING ACROSS OK/THE TX PANHANDLE DURING THE DAY...AS UPPER VORT MAX MOVES SWD/SWWD AROUND ERN PERIPHERY OF UPPER HIGH. SUFFICIENT MOISTURE/INSTABILITY ALONG THE SURFACE FRONT SHOULD ALLOW ONGOING THUNDERSTORMS EARLY IN THE PERIOD TO PERSIST -- AND THEN INCREASE DURING THE AFTERNOON COINCIDENT WITH DIURNAL HEATING. THOUGH FLOW ALOFT WILL BE RELATIVELY WEAK...SLY FLOW AT LOW LEVELS BENEATH UPPER NLYS MAY PROVIDE SUFFICIENT SHEAR FOR SOME STORM ORGANIZATION. THIS COMBINED WITH HOT/DEEP MIXED LAYER SUGGESTS A POTENTIAL FOR ISOLATED DAMAGING GUSTS. WILL THEREFORE INTRODUCE 5% SEVERE PROBABILITY ACROSS THIS AREA...WITH SOME POTENTIAL FOR A SLIGHT RISK UPGRADE IN LATER FORECASTS. ...NRN NEW ENGLAND... MODERATE NWLY FLOW ALOFT IS FORECAST ACROSS NEW ENGLAND ON BACK SIDE OF MAIN UPPER TROUGH OFFSHORE. TIMING OF SMALLER-SCALE DISTURBANCES MOVING SEWD ACROSS NEW ENGLAND REMAINS DIFFICULT...BUT MODELS HINT THAT ONE FEATURE MAY CROSS THE REGION EARLY IN THE DAY...AND A SECOND FEATURE MAY APPROACH LATE IN THE AFTERNOON. DESPITE QUESTIONS REGARDING TIMING...POTENTIAL FOR SUFFICIENT DESTABILIZATION AND MODERATE FLOW ALOFT SUPPORT MAINTAINING 5% SEVERE PROBABILITY ACROSS THIS REGION. ...N CENTRAL MT... VERY SUBTLE UPPER DISTURBANCES ARE FORECAST TO MOVE EWD ACROSS SERN BRITISH COLUMBIA/SRN ALBERTA/SRN SASKATCHEWAN DURING THE DAY...WITHIN FAST BELT OF WEAKLY ANTICYCLONIC FLOW AROUND NRN PERIPHERY OF WRN U.S. RIDGE. LOW-LEVEL BAROCLINIC ZONE IS FORECAST TO LIE ACROSS ID/MT...THOUGH DESTABILIZATION ALONG THIS FRONT IS FORECAST TO BE MINIMAL AT BEST. COULD A FEW ISOLATED STORMS INITIATE OVER THE HIGHER TERRAIN OF MT...STRENGTH OF FLOW ALOFT WOULD SUPPORT A THREAT FOR DAMAGING WINDS. HOWEVER...GIVEN MEAGER INSTABILITY AND POTENTIAL THAT ANY STORMS WILL REMAIN N OF THE CANADA/U.S. BORDER...WILL MAINTAIN ONLY A SMALL CONDITION 5% SEVERE THREAT ACROSS THIS REGION. ..GOSS.. 07/13/2006  From swody2 at goshenarc.org Fri Jul 14 06:06:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 14 Jul 2006 02:06:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140604 SWODY2 SPC AC 140603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0103 AM CDT FRI JUL 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AN ELONGATED DOMINANT ZONE OF HIGH PRESSURE ALOFT WILL BUILD EWD ACROSS THE OH VALLEY DURING THE DAY2 PERIOD IN THE WAKE OF WEAK UPPER TROUGH. LARGE SCALE SUBSIDENCE AND WARM TEMPERATURES ALOFT WILL PROVE HOSTILE FOR ORGANIZED DEEP CONVECTION ACROSS MUCH OF THE MID SECTION OF THE U.S. ...NERN U.S... DOWNSTREAM...THUNDERSTORMS SHOULD DEVELOP EASILY AHEAD OF UPPER TROUGH AXIS OVER PORTIONS OF THE NERN U.S. WHERE MID LEVELS WILL REMAIN FAVORABLY COOL AND BOUNDARY LAYER TEMPERATURES WILL WARM RAPIDLY BY MID DAY. DESPITE WEAK LOW LEVEL CONVERGENCE IT APPEARS THERE MAY BE A ZONE OF ENHANCED THUNDERSTORM ACTIVITY FROM ERN NY INTO ME...AIDED BY UPPER TROUGH AND JUST ENOUGH DEEP LAYER SHEAR FOR A FEW STRONG THUNDERSTORMS. ...UPPER MS VALLEY... PLUME OF VERY WARM TEMPERATURES WILL ADVECT OFF THE NRN ROCKIES/HIGH PLAINS REGION NEWD INTO THE ERN DAKOTAS SATURDAY. LATEST MODEL GUIDANCE INDICATES BOUNDARY LAYER PARCELS WILL STRUGGLE TO REACH THEIR LFC UNTIL LATE IN THE AFTERNOON WHEN SFC TEMPERATURES SOAR TO NEAR OR ABOVE 100F. IN THE ABSENCE OF HEIGHT FALLS ACROSS THIS REGION ANY STORMS THAT DEVELOP ALONG A WIND SHIFT FROM NWRN MN INTO ERN ND MAY PROVE SHORT LIVED...ALTHOUGH GUSTY WINDS ARE POSSIBLE. OTHERWISE...MAJORITY OF CONVECTION SHOULD DEVELOP FARTHER NORTHEAST WITHIN WARM ADVECTION ZONE OVER WRN ONTARIO. ...AZ... RATHER LARGE UPPER LEVEL CIRCULATION IS MOVING WWD ACROSS THE WRN GULF OF MEXICO AND SHOULD PROGRESS ACROSS THE BODY OF MEXICO OVER THE NEXT COUPLE OF DAYS. MOISTURE SHOULD GRADUALLY RETURN NWWD INTO PORTIONS OF THE SWRN U.S. WHERE ELY FLOW SHOULD STRENGTHEN AND PROVIDE SUFFICIENT SHEAR FOR MULTICELL STORM STRUCTURES. GUSTY WINDS WILL BE POSSIBLE WITH MOISTENING CONVECTION ACROSS THIS REGION. ..DARROW.. 07/14/2006  From swody2 at goshenarc.org Mon Jul 17 06:00:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 17 Jul 2006 02:00:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170557 SWODY2 SPC AC 170556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON JUL 17 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NERN U.S. AND OH VALLEY... ...OH VALLEY/NERN U.S... DEEP WLY FLOW AROUND THE NRN PERIPHERY OF DOMINANT UPPER HIGH WILL ALLOW STEEP LAPSE RATE PLUME TO SPREAD ACROSS SRN ONTARIO INTO PORTIONS OF THE NERN U.S...IN ADDITION TO THE OH VALLEY REGION. WITH SUBSTANTIAL BOUNDARY LAYER MOISTURE IN PLACE...THERMODYNAMIC PROFILES WILL PROVE MORE THAN ADEQUATE FOR ROBUST CONVECTION TUESDAY. IT APPEARS HEIGHT FALLS IN ASSOCIATION WITH PROGRESSIVE UPPER TROUGH WILL DEVELOP ACROSS MUCH OF THE NERN U.S. EARLY IN THE PERIOD ALLOWING SFC FRONT TO ADVANCE ACROSS ONTARIO/QUEBEC INTO NRN NEW ENGLAND...SWWD INTO OH BY 18Z. THUNDERSTORMS SHOULD READILY DEVELOP ALONG THIS ZONE OF CONVERGENCE AND SPREAD ESEWD AT ROUGHLY 30-40KT. DAMAGING WINDS APPEAR LIKELY WITH THIS ACTIVITY GIVEN STEEP LAPSE RATE ENVIRONMENT AND STORM MOTIONS. AT THIS TIME WILL MAINTAIN MODEST SEVERE PROBABILITIES FOR THIS ACTIVITY. HOWEVER...WIND PROBABILITIES MAY NEED TO BE INCREASED IN LATER OUTLOOKS AS ORGANIZED SQUALL LINE STRUCTURE WITHIN THIS DEVELOPING FLOW REGIME MAY ULTIMATELY PRODUCE MORE WIDESPREAD SEVERE. ...NRN PLAINS/UPPER-MID MS VALLEY... ANOTHER IN A SERIES OF UPPER SHORTWAVE TROUGHS WILL ADVECT ACROSS THE NRN ROCKIES/SRN CANADA TOWARD THE UPPER MS VALLEY LATE IN THE PERIOD. THIS FEATURE WILL ENHANCE LOW LEVEL WARM ADVECTION ACROSS THE PLAINS INTO MN AS LLJ INCREASES...ESPECIALLY AFTER DARK. IT APPEARS THUNDERSTORMS WILL DEVELOP WITHIN THIS EVOLVING ASCENT REGION DURING THE OVERNIGHT HOURS...POSSIBLY ORGANIZING INTO AN MCS BY MORNING OVER PORTIONS OF ERN SD INTO SRN MN AND NRN IA. IT'S NOT ENTIRELY CLEAR WHETHER THIS ACTIVITY WILL BE SEVERE IN NATURE GIVEN THE HIGH THICKNESS VALUES AND INTENSE HEAT AIRMASS THIS CONVECTION WILL ULTIMATELY EVOLVE FROM. LATE AFTERNOON STORMS COULD FORM ALONG WIND SHIFT OVER WRN SD WHERE STEEP LAPSE RATE ENVIRONMENT WILL RESULT IN HIGH BASED INVERTED-V TYPE ACTIVITY. STRENGTHENING LLJ MAY ULTIMATELY ALLOW THIS CONVECTION TO PROPAGATE EWD DURING THE OVERNIGHT HOURS WHERE STRUCTURES SHOULD BECOME ELEVATED IN NATURE FARTHER EAST. GUSTY WINDS SHOULD BE THE PRIMARY SEVERE THREAT. ..DARROW.. 07/17/2006  From swody2 at goshenarc.org Mon Jul 17 17:23:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 17 Jul 2006 13:23:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 171721 SWODY2 SPC AC 171720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 PM CDT MON JUL 17 2006 VALID 181200Z - 191200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND INTO THE OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLAINS... ...SYNOPSIS... STRONGER WESTERLY FLOW ALOFT WILL REMAIN ALONG THE NRN TIER OF STATES AS TWO SHORT WAVE TROUGHS PROGRESS EWD ACROSS THE CANADIAN/US BORDER. LEAD SHORT WAVE CURRENTLY APPROACHING THE UPPER GREAT LAKES WILL MOVE FROM WRN QUEBEC AND THE LOWER GREAT LAKES EWD ACROSS THE ST LAWRENCE VALLEY/NRN NEW ENGLAND TOMORROW...AS UPSTREAM TROUGH MOVES ACROSS THE SRN CANADIAN PRAIRIE PROVINCES. FARTHER SOUTH...LOW LATITUDE TROUGH IN THE SUBTROPICAL EASTERLIES WILL CONTINUE WWD INTO THE PACIFIC OFF NRN BAJA AS INVERTED TROUGH MOVE NWWD ACROSS CENTRAL/SRN CA. AT THE SURFACE...A COLD FRONT WILL MOVE SEWD ACROSS NEW ENGLAND AND THE OH VALLEY. THE WRN PART OF THE FRONT WILL BEGIN TO LIFT NWD DURING THE EVENING AS A LOW CENTER DEVELOPS EWD INTO NRN NEB/SRN SD...AND A SECOND COLD FRONT MOVES SEWD ACROSS THE DAKOTAS. ...NERN STATES/OH VALLEY... AMPLE LOW LEVEL MOISTURE WITH SURFACE DEW POINTS IN THE UPPER 60S/LOWER 70S WILL BE PRESENT AHEAD OF THE ADVANCING COLD FRONT...BENEATH AN ELEVATED MIXED LAYER PLUME EXTENDING EWD FROM THE PLAINS INTO PARTS OF NEW ENGLAND. THE STEEP MID LEVEL LAPSE RATES ABOVE THE LOW LEVEL MOISTURE LAYER WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPE OF 1500-2500 J/KG AND PROVIDE A VERY FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT. A BAND OF THUNDERSTORMS IS EXPECTED TO BE ONGOING IN THE MORNING ALONG THE COLD FRONT FROM THE LOWER GREAT LAKES NEWD INTO NRN NEW ENGLAND. THE CAPPING INVERSION ASSOCIATED WITH THE EML IN SRN NEW ENGLAND IS EXPECTED TO INHIBIT CONVECTIVE INITIATION IN THE WARM SECTOR SOUTH OF THE FRONT DURING THE MORNING. STORMS ALONG/IMMEDIATELY AHEAD OF THE FRONT ARE LIKELY TO INTENSIFY BY MID/LATE MORNING AS STRONG INSOLATION DESTABILIZES THE PRE-CONVECTIVE ENVIRONMENT...AND DYNAMIC FORCING FOR LARGE SCALE ASCENT INCREASES WITHIN RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET MOVING ACROSS THE ST LAWRENCE VALLEY. ALTHOUGH THE STRONGEST VERTICAL SHEAR WILL BE LOCATED PRIMARILY NORTH OF THE COLD FRONT...DEEP LAYER SHEAR OF 25-35 KT WILL BE SUFFICIENT TO ENHANCE CONVECTIVE ORGANIZATION WITH POTENTIAL FOR A FEW SUPERCELLS TO DEVELOP...ESPECIALLY OVER PARTS OF NEW ENGLAND/SERN NY INTO NRN PA. UNIDIRECTIONAL WIND PROFILES ABOVE THE PBL SUGGEST PRIMARY CONVECTIVE MODE WILL BE IN THE FORM OF LINE SEGMENTS INCLUDING EMBEDDED BOW ECHOES GIVEN THE DRY AIR WITHIN THE ELEVATED MIXED LAYER AND ENHANCED POTENTIAL FOR STRONG DOWNDRAFTS. ALTHOUGH VERTICAL SHEAR DECREASES WITH WWD EXTENT ACROSS THE OH VALLEY...SUFFICIENT INSTABILITY/DRY AIR ALOFT SUGGESTS POTENTIAL FOR A FEW SEVERE STORMS INTO PARTS OF THE OH VALLEY. SEVERE THREAT IS EXPECTED TO DIMINISH BY 03-06Z. ...NRN PLAINS INTO UPPER MS VALLEY... THE ELEVATED MIXED LAYER WILL PERSIST FROM THE ROCKIES INTO THE NRN PLAINS TOMORROW...EFFECTIVELY CAPPING DEVELOPMENT OF SURFACE-BASED CONVECTION THROUGH MOST OF THE PERIOD. AS THE WARM FRONT LIFTS NWD ACROSS THE LOWER/MIDDLE MO RIVER VALLEY DURING THE LATE AFTERNOON INTO THE OVERNIGHT HOURS...MOISTURE WILL RETURN NWD INTO IA/ERN NEB/CENTRAL AND ERN SD/SRN MN BENEATH THE EML. ALTHOUGH THERE IS POTENTIAL FOR ISOLATED HIGH-BASED THUNDERSTORMS TO DEVELOP EWD ACROSS THE NRN HIGH PLAINS DURING THE LATE AFTERNOON AND EVENING WITH AN ATTENDANT THREAT FOR LOCAL MICROBURSTS...THE PRIMARY ELEVATED CONVECTIVE DEVELOPMENT IS EXPECTED DURING THE OVERNIGHT HOURS AS WARM ADVECTION LIFT INCREASES NORTH OF THE WARM FRONT AS THE NOCTURNAL LOW LEVEL JET INTENSIFIES. VERTICAL WIND PROFILES ARE FORECAST TO EXHIBIT PRONOUNCED VEERING WITH HEIGHT AS A STRONG MID LEVEL JET STREAK ASSOCIATED WITH THE NEXT SHORT WAVE TROUGH MOVES EWD ACROSS THE NRN PLAINS. THIS WILL PROVIDE SUFFICIENT SHEAR TO SUPPORT ISOLATED ELEVATED SUPERCELLS AFTER 03-06Z...WITH STRONGER CELLS CAPABLE OF PRODUCING LARGE HAIL. ..WEISS.. 07/17/2006  From swody2 at goshenarc.org Tue Jul 18 05:44:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 01:44:24 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180541 SWODY2 SPC AC 180540 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1240 AM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES REGION... DOMINANT UPPER RIDGE WILL REMAIN ANCHORED OVER THE CNTRL PLAINS WHILE TRANSITORY SHORTWAVES RIPPLE EWD ALONG THE U.S./CANADIAN BORDER. ANOTHER SIGNIFICANT TROUGH...AND ASSOCIATED SPEED MAX...WILL APPROACH THE UPPER MS VALLEY/UPPER GREAT LAKES REGION DURING THE LATTER HALF OF THE PERIOD FORCING A SFC COLD FRONT INTO NWRN MN...TRAILING SWWD INTO ERN SD BY MID DAY. EARLY IN THE PERIOD...STRONG LOW LEVEL WARM ADVECTION AND A FOCUSED LLJ INTO SERN SD/SWRN MN WILL LIKELY ENHANCE MCS-TYPE CONVECTION ALONG ERN EDGE OF STRONGER CAPPED REGION. THESE STORMS WILL UNDOUBTEDLY BE ELEVATED WITH INFLOW PARCEL LAYER LIKELY ABOVE 850MB. STEEP LAPSE RATE ENVIRONMENT MAY ENHANCE GUSTY WIND POTENTIAL DESPITE THE DEEP STABLE BOUNDARY LAYER. MODELS ARE IN GENERAL AGREEMENT THAT THIS ACTIVITY MAY LINGER THROUGH THE MORNING WITH POSSIBLE REGENERATION AS WARM SECTOR HEATS ACROSS IA. SWD EXTENT OF THIS CONVECTION IS SOMEWHAT QUESTIONABLE AS VERY HIGH THICKNESS VALUES WILL BE NOTED...RESULTING IN EXTREME SFC TEMPERATURES NECESSARY FOR PARCELS TO FREELY CONVECT. UPSTREAM...LATE AFTERNOON THUNDERSTORMS SHOULD DEVELOP ALONG ADVANCING COLD FRONT ACROSS MN WHERE THERMODYNAMIC PROFILES WILL BE MUCH COOLER AND LESS INHIBITED. UPWARD EVOLUTION INTO AN MCS COULD OCCUR AS SPEED MAX DIGS INTO NWRN WI. ADDITIONALLY...LLJ SHOULD FOCUS INTO THIS REGION AFTER DARK ALLOWING COMPLEX TO PROPAGATE TOWARD LAKE SUPERIOR. ..DARROW.. 07/18/2006  From swody2 at goshenarc.org Tue Jul 18 06:11:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 02:11:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180609 SWODY2 SPC AC 180607 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0107 AM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES REGION... DOMINANT UPPER RIDGE WILL REMAIN ANCHORED OVER THE CNTRL PLAINS WHILE TRANSITORY SHORTWAVES RIPPLE EWD ALONG THE U.S./CANADIAN BORDER. ANOTHER SIGNIFICANT TROUGH...AND ASSOCIATED SPEED MAX...WILL APPROACH THE UPPER MS VALLEY/UPPER GREAT LAKES REGION DURING THE LATTER HALF OF THE PERIOD FORCING A SFC COLD FRONT INTO NWRN MN...TRAILING SWWD INTO ERN SD BY MID DAY. EARLY IN THE PERIOD...STRONG LOW LEVEL WARM ADVECTION AND A FOCUSED LLJ INTO SERN SD/SWRN MN WILL LIKELY ENHANCE MCS-TYPE CONVECTION ALONG ERN EDGE OF STRONGER CAPPED REGION. THESE STORMS WILL UNDOUBTEDLY BE ELEVATED WITH INFLOW PARCEL LAYER LIKELY ABOVE 850MB. STEEP LAPSE RATE ENVIRONMENT MAY ENHANCE GUSTY WIND POTENTIAL DESPITE THE DEEP STABLE BOUNDARY LAYER. MODELS ARE IN GENERAL AGREEMENT THAT THIS ACTIVITY MAY LINGER THROUGH THE MORNING WITH POSSIBLE REGENERATION AS WARM SECTOR HEATS ACROSS IA. SWD EXTENT OF THIS CONVECTION IS SOMEWHAT QUESTIONABLE AS VERY HIGH THICKNESS VALUES WILL BE NOTED...RESULTING IN EXTREME SFC TEMPERATURES NECESSARY FOR PARCELS TO FREELY CONVECT. UPSTREAM...LATE AFTERNOON THUNDERSTORMS SHOULD DEVELOP ALONG ADVANCING COLD FRONT ACROSS MN WHERE THERMODYNAMIC PROFILES WILL BE MUCH COOLER AND LESS INHIBITED. UPWARD EVOLUTION INTO AN MCS COULD OCCUR AS SPEED MAX DIGS INTO NWRN WI. ADDITIONALLY...LLJ SHOULD FOCUS INTO THIS REGION AFTER DARK ALLOWING COMPLEX TO PROPAGATE TOWARD LAKE SUPERIOR. ..DARROW.. 07/18/2006  From swody2 at goshenarc.org Tue Jul 18 17:25:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 18 Jul 2006 13:25:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 181722 SWODY2 SPC AC 181721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT TUE JUL 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY INTO THE UPR GREAT LAKES... ...SYNOPSIS... PROGRESSIVE UPPER FLOW PATTERN WITHIN THE STRONGER WESTERLIES ALOFT IS FORECAST TO CONTINUE ACROSS THE NRN TIER OF STATES TOMORROW AS UPPER RIDGE REMAINS ANCHORED ACROSS THE CENTRAL PARTS OF THE PLAINS AND ROCKIES. PRIMARY SHORT WAVE TROUGH CURRENTLY MOVING ACROSS SRN ALBERTA AND SRN BRITISH COLUMBIA IS EXPECTED TO PROGRESS ESEWD REACHING THE UPPER MS VALLEY/UPPER GREAT LAKES BY THE END OF THE PERIOD. ASSOCIATED NE/SW SURFACE COLD FRONT WILL MOVE EWD ACROSS THE NRN PLAINS AND UPPER MS VALLEY...REACHING A WRN LAKE SUPERIOR/SWRN MN/NRN NEB LINE BY 20/00Z...AND CONTINUING TO ERN LAKE SUPERIOR/SWRN WI/SWRN IA BY THE END OF THE PERIOD. A WARM FRONT WILL LIFT RAPIDLY NWD ACROSS THE UPPER MS VALLEY DURING THE MORNING WITH A VERY MOIST WARM SECTOR DEVELOPING BY AFTERNOON. ...NRN PLAINS/UPPER MS VALLEY INTO THE UPPER GREAT LAKES... THERMODYNAMIC ENVIRONMENT WILL BE INCREASINGLY FAVORABLE FOR STRONG/SEVERE CONVECTION AS LOW LEVEL MOISTURE RETURNS NWD BENEATH PRE-EXISTING PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE ELEVATED MIXED LAYER FROM THE NRN PLAINS ACROSS THE UPPER MS VALLEY. ELEVATED THUNDERSTORMS MAY BE OCCURRING IN THE MORNING ACROSS PARTS OF THE DAKOTAS WITH STRONGER STORMS CAPABLE OF PRODUCING ISOLATED HAIL AND STRONG WIND GUSTS. PRIMARY SEVERE THREAT IS EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING AS THE ELEVATED CONVECTION SPREADS EWD TOWARD THE FRONTAL ZONE WITH POTENTIAL TO BECOME ROOTED IN THE BOUNDARY LAYER...AND ADDITIONAL STORMS ARE LIKELY TO DEVELOP ALONG/JUST AHEAD OF THE FRONT AS LOW LEVEL CONVERGENCE AND STRONG HEATING LOCALLY WEAKENS THE CAP. ENVIRONMENT IS FORECAST TO BECOME VERY UNSTABLE NEAR THE FRONT AS SURFACE TEMPERATURES WARM INTO THE 90S AND DEW POINTS INCREASE INTO THE 70S...CONTRIBUTING TO MLCAPE OF 2500-4000 J/KG. VERTICAL SHEAR IS ALSO EXPECTED TO STRENGTHEN AS FORECAST SOUNDINGS EXHIBIT WIND PROFILES THAT VEER AND INCREASE WITH HEIGHT...IN RESPONSE TO A 50-60 KT MID LEVEL JET STREAK MOVING ACROSS ND INTO MN ON THE SOUTH SIDE OF THE SHORT WAVE TROUGH. COMBINATION OF STRONG INSTABILITY AND MODERATE DEEP LAYER SHEAR INDICATES POTENTIAL FOR A FEW SUPERCELLS TO DEVELOP...PRIMARILY FROM ERN SD INTO CENTRAL/SRN MN DURING THE AFTERNOON SPREADING EWD INTO PARTS OF WI AT NIGHT. STEEP LAPSE RATES/LARGE INSTABILITY AND A FAVORABLY SHEARED ENVIRONMENT SUGGEST STRONGER STORMS WILL BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WIND GUSTS...AND A FEW TORNADOES. THE TORNADO THREAT WILL BE ENHANCED IF DISCRETE CELLS CAN BE MAINTAINED INTO THE EVENING HOURS. CONVECTION IS EXPECTED TO GROW UPSCALE INTO ONE OR MORE MCS/S DURING THE OVERNIGHT HOURS WITH SEVERE THREAT CONTINUING AFTER DARK TOWARD THE UPPER GREAT LAKES. UNCERTAINTY IN CONVECTIVE MODE PRECLUDES INTRODUCTION OF A HIGHER RISK CATEGORY ATTM BUT REGION WILL BE MONITORED FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ...ERN NC INTO SERN VA... TROPICAL DEPRESSION OFF THE NC COAST IS FORECAST TO TURN NWWD TOWARD THE NC OUTER BANKS TOMORROW /SEE LATEST FORECASTS FROM TPC/. THIS MOTION WILL PLACE REGION OF STRONGER CYCLONIC LOW LEVEL FLOW/VERTICAL SHEAR INTO COASTAL SECTIONS OF NERN NC/SERN VA BEGINNING LATER TOMORROW AFTERNOON. THIS SUGGESTS INCREASING POTENTIAL FOR STRONGER CONVECTION ACROSS THIS AREA...ALTHOUGH CURRENT TRACK FORECAST WILL KEEP FAVORED CLIMATOLOGICAL SECTOR FOR TROPICAL CYCLONE TORNADOES MAINLY OFFSHORE. ..WEISS.. 07/18/2006  From swody2 at goshenarc.org Wed Jul 19 05:41:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 19 Jul 2006 01:41:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190538 SWODY2 SPC AC 190537 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT WED JUL 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER GREAT LAKES AND OH/MID MS VALLEY REGION... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN AND CNTRL HIGH PLAINS... ...SYNOPSIS... DOMINANT HIGH PRESSURE WILL BE SUPPLANTED BY BROAD UPPER TROUGHING WITH SEVERAL DISTINCT SIGNIFICANT SHORTWAVE TROUGHS FROM THE NRN PLAINS TO THE OH VALLEY DURING THE NEXT FEW DAYS. THIS TRANSITION WILL LIKELY RESULT IN CONSIDERABLE AREAL COVERAGE OF DEEP CONVECTION ALONG THE LEADING EDGE OF ADVANCING FRONTAL ZONE. ...LOWER GREAT LAKES/OH VALLEY/MID MS VALLEY... MCS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD FROM LOWER MI INTO NERN IL...AN EXTENSION OF DAY1 COMPLEX THAT SHOULD SPREAD SEWD ACROSS THE UPPER GREAT LAKES. DAY2 CONVECTIVE EVOLUTION MAY BE SOMEWHAT MODULATED BY INTENSITY OF EARLY MORNING ACTIVITY. THERE IS A DISTINCT POSSIBILITY THAT AN ELONGATED SEVERE SQUALL LINE WILL PROPAGATE SEWD ACROSS THE OH VALLEY AHEAD OF WELL DEFINED UPPER TROUGH. STEEP LAPSE RATE PLUME AND MODERATE BOUNDARY LAYER INSTABILITY SHOULD ENHANCE THE POTENTIAL FOR DAMAGING WINDS AS THIS ACTIVITY SPREADS ACROSS IND/OH...NEWD INTO UPSTATE NY. CONVECTION WILL STRUGGLE TO SPREAD/DEVELOP SWWD INTO MO WHERE STRONG CAP AND LESS FAVORABLE THERMODYNAMIC PROFILES WILL PROVE HOSTILE TO BOUNDARY LAYER DEVELOPMENT...IN ADDITION TO NEGLIGIBLE INFLUENCE FROM UPPER TROUGH. ...NRN/CNTRL HIGH PLAINS... SECONDARY SPEED MAX/SHORTWAVE TROUGH WILL SUPPRESS UPPER RIDGE OVER THE HIGH PLAINS THURSDAY. THIS FEATURE WILL UNDOUBTEDLY AID VERTICAL ASCENT FROM ERN MT/WRN DAKOTAS...SWD INTO THE NEB PANHANDLE WHERE ELY COMPONENT TO BOUNDARY LAYER FLOW WILL ENHANCE UPSLOPE COMPONENT AND LOW LEVEL SHEAR. FORECAST SOUNDINGS FOR THIS REGION STRONGLY SUGGEST SUPERCELLS WILL DEVELOP BY MID AFTERNOON...INITIALLY ACROSS NRN AREAS...WITH SEWD MOVEMENT EXPECTED DURING THE OVERNIGHT HOURS. INCREASING LLJ INTO THIS ACTIVITY ALSO FAVORS ONE OR MORE MCS-TYPE COMPLEXES AS CONVECTION CONSOLIDATES AND BECOMES ELEVATED AFTER DARK OVER THE CNTRL PLAINS. ISOLATED TORNADOES SEEM POSSIBLE EARLY IN STORM EVOLUTION...THEN DAMAGING WINDS AND HAIL WITH THE LARGER CLUSTERS. ...SWRN U.S... PRECIPITABLE WATER VALUES REMAIN SEASONABLY HIGH ACROSS AZ INTO SRN CA...WITH VALUES WELL IN EXCESS OF 1 IN NEAR THE BORDER. LARGE SCALE FLOW REGIME HAS YET TO CHANGE AND THIS SHOULD RESULT IN ANOTHER CONVECTIVELY ACTIVE DAY ACROSS THIS REGION. SLIGHT RISK MAY NEED TO BE ADDED IN LATER OUTLOOKS TO ADDRESS THE POSSIBILITY FOR WWD PROPAGATING ORGANIZED THUNDERSTORMS ACROSS THE DESERTS. ..DARROW.. 07/19/2006  From swody2 at goshenarc.org Wed Jul 19 17:32:26 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 19 Jul 2006 13:32:26 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191728 SWODY2 SPC AC 191727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 PM CDT WED JUL 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDDLE MS VALLEY ACROSS THE GREAT LAKES REGION... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SYNOPSIS... UPPER FLOW PATTERN IS FORECAST TO AMPLIFY TOMORROW AS LEAD SHORT WAVE TROUGH CURRENTLY ACROSS THE SRN CANADIAN PRAIRIE PROVINCES/FAR NRN PLAINS PROGRESSES EWD ACROSS ERN CANADA...WHILE UPSTREAM SHORT WAVE TROUGH NEARING THE BRITISH COLUMBIA COAST IS PREDICTED TO DIG SEWD OVER THE NRN PLAINS IN RESPONSE TO BUILDING RIDGE OVER THE NRN INTERMOUNTAIN REGION. SURFACE COLD FRONT IS EXPECTED TO MOVE EWD/SEWD ACROSS THE GREAT LAKES AND CENTRAL PLAINS...REACHING A SERN QUEBEC/WRN PA/SRN INDIANA/SRN KS LINE BY THE END OF THE PERIOD. ...GREAT LAKES/OH VALLEY REGION... A BAND OF STRONG/LOCALLY SEVERE CONVECTION ALONG/AHEAD OF THE COLD FRONT MAY BE OCCURRING EARLY IN THE PERIOD FROM LAKE HURON/LOWER MI SWWD INTO NRN/CENTRAL IL AS DAY 1 OVERNIGHT MCS CONTINUES INTO THE DAY 2 PERIOD. AMPLE LOW LEVEL MOISTURE WITH SURFACE DEW POINTS GENERALLY IN THE UPPER 60S/LOWER 70S (LOCALLY MID/UPPER 70S OVER THE MIDDLE MS VALLEY) WILL BE PRESENT AHEAD OF THE FRONT AND/OR ANY EFFECTIVE OUTFLOW BOUNDARIES. PLUME OF STEEPER MID LEVEL LAPSE RATES WILL EXTEND FROM THE MIDDLE MS VALLEY ENEWD INTO THE LOWER GREAT LAKES IN ADVANCE OF CONVECTIVE ACTIVITY. THIS WILL ENHANCE INSTABILITY IN REGIONS WHERE LIMITED CLOUD COVER AND STRONGER DIURNAL HEATING OCCUR...WITH AFTERNOON MLCAPE RANGING FROM 1000-1500 J/KG FROM THE ST LAWRENCE VALLEY INTO THE UPPER OH VALLEY TO 2500-4000 J/KG ACROSS THE MIDDLE MS VALLEY. PRIMARY MID/UPPER LEVEL JET WILL CURVE CYCLONICALLY FROM THE UPPER GREAT LAKES INTO THE ST LAWRENCE VALLEY...WITH A SECONDARY JET STREAM ARCING ANTI-CYCLONICALLY FROM THE UPPER MS VALLEY ACROSS THE LOWER OH/TN VALLEYS. THIS DIFFLUENT JET PATTERN WILL ENHANCE UPPER LEVEL DIVERGENCE ACROSS THE LOWER GREAT LAKES INTO THE OH VALLEY WITH RESULTANT INCREASE IN LARGE SCALE ASCENT ABOVE THE LOW LEVEL FRONTAL ZONE. THIS SHOULD SUPPORT ADDITIONAL BANDS OF THUNDERSTORMS BEGINNING IN THE AFTERNOON...WITH ACTIVITY SPREADING EWD/SEWD AHEAD OF THE FRONT. DEEP LAYER VERTICAL SHEAR OF 30-40 KT FROM THE LOWER LAKES INTO THE ST LAWRENCE VALLEY WILL SUPPORT ORGANIZED SEVERE CONVECTION /INCLUDING POSSIBILITY OF ISOLATED SUPERCELLS/ WITH PRIMARY THREAT FOR DAMAGING WIND GUSTS AND LARGE HAIL WITH STRONGER CELLS. THIS ACTIVITY IS LIKELY TO REMAIN ORGANIZED AND PERSIST THROUGH THE OVERNIGHT HOURS EVENTUALLY REACHING UPSTATE NY/NRN VT AFTER 06Z. ALTHOUGH VERTICAL SHEAR IS FORECAST TO BE WEAKER /20-30 KT IN THE LOWEST 6 KM/ FARTHER SOUTHWEST ACROSS THE MIDDLE MS/LOWER OH VALLEYS...LARGER VALUES OF MLCAPE WILL BE SUPPORTIVE OF SEVERE STORMS. WEAKER DYNAMIC FORCING OVER THIS REGION SUGGESTS STORMS WILL GRADUALLY DECREASE IN COVERAGE AND INTENSITY DURING THE 03-06Z PERIOD. ...NRN HIGH PLAINS INTO CENTRAL PLAINS... LOW LEVEL UPSLOPE FLOW IS FORECAST TO DEVELOP OVER THE CENTRAL/NRN HIGH PLAINS NORTH OF THE SURFACE FRONT...WHICH WILL RESULT IN AN AXIS OF HIGHER DEW POINTS SPREADING FROM NRN KS/SRN NEB NWWD INTO ERN PARTS OF WY/MT AND THE WRN PARTS OF THE DAKOTAS AND NEB. A STEEP LAPSE RATE ENVIRONMENT COUPLED WITH INCREASING LOW LEVEL MOISTURE WILL RESULT IN UNSTABLE CONDITIONS WITH MUCAPE RANGING FROM OF 1000-1500 J/KG OVER THE HIGH PLAINS TO 2000-3000 J/KG OVER SRN NEB/NRN KS. THUNDERSTORMS ARE EXPECTED TO INCREASE/INTENSIFY DURING THE AFTERNOON OVER THE NRN HIGH PLAINS AS THE NEXT SHORT WAVE TROUGH DIGS SEWD FROM MT TOWARD THE NRN/CENTRAL PLAINS. FORECAST SOUNDINGS EXHIBIT PRONOUNCED DIRECTIONAL/SPEED SHEAR WITH HEIGHT AS LOW LEVEL SELY WINDS VEER TO WESTERLY IN THE MIDDLE LEVELS...PROVIDING A FAVORABLE ENVIRONMENT FOR SEVERE STORMS INCLUDING A FEW SUPERCELLS. LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES WILL BE POSSIBLE WITH STRONGER CELLS DURING THE AFTERNOON AND EVENING. THE CONVECTION IS EXPECTED TO CONSOLIDATE INTO ONE OR MORE MCS/S FROM THE LATE EVENING THROUGH THE OVERNIGHT HOURS AS IT SPREADS SEWD INTO PARTS OF NEB AND POSSIBLY FAR NRN KS WHERE ELEVATED MOISTURE/INSTABILITY WILL BE PRESENT NORTH OF THE SURFACE FRONT. PRIMARY SEVERE THREAT IS EXPECTED TO GRADUALLY TRANSITION TO LARGE HAIL AND ISOLATED WIND DAMAGE AS LOW LEVEL WARM ADVECTION/CONVERGENCE ALONG AND NORTH OF THE FRONT STRENGTHENS IN RESPONSE TO THE DEVELOPING NOCTURNAL LOW LEVEL JET OVER THE PLAINS. ...LOWER MS VALLEY/GULF COAST... FORECAST SOUNDINGS ACROSS THIS REGION INDICATE VERY WARM/MOIST LOW LEVEL AIR MASS WILL PERSIST TOMORROW...WITH A STRONG DECREASE IN THETA-E PREDICTED ABOVE 850 MB. THE PRESENCE OF DRIER AIR ALOFT COUPLED WITH ANTICIPATED DEVELOPMENT OF STEEP LAPSE RATES IN THE LOWEST 1-2 KM SUGGEST POTENTIAL FOR A FEW WET MICROBURSTS TO DEVELOP DURING THE AFTERNOON AND EVENING. NELY MID LEVEL WINDS OF 15-25 KT MAY ALLOW MARGINALLY ORGANIZED CONVECTION TO PERSIST ACROSS THIS REGION...BUT OVERALL COVERAGE IS NOT EXPECTED TO WARRANT A SLIGHT RISK ATTM. ...AZ/EXTREME SERN CA... SYNOPTIC PATTERN THAT IS DOMINATED BY UPPER RIDGE FROM THE GREAT BASIN EWD INTO THE PLAINS WILL CONFINE STRONGER ELY COMPONENT OF THE DEEP LAYER FLOW ACROSS SRN PART OF AZ. PRESENCE OF A DEEP SURFACE-BASED WELL-MIXED LAYER AND SUFFICIENT MOISTURE WILL ALLOW THUNDERSTORMS TO DEVELOP OVER PARTS OF THE RIM AND MOUNTAINS OF EAST CENTRAL/SERN AZ...WITH ACTIVITY PROPAGATING PRIMARILY WWD ACROSS THE LOWER DESERTS TOWARD THE LOWER CO RIVER VALLEY. ALTHOUGH THERE IS TYPICAL UNCERTAINTY IN THE DETAILS OF CONVECTIVE EVOLUTION ACROSS THIS AREA...POTENTIAL WILL EXIST FOR A FEW WET MICROBURSTS TO DEVELOP. ..WEISS.. 07/19/2006  From swody2 at goshenarc.org Thu Jul 20 06:02:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 20 Jul 2006 02:02:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200559 SWODY2 SPC AC 200558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT THU JUL 20 2006 VALID 211200Z - 221200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS TO MIDDLE TN... SECONDARY UPSTREAM SHORTWAVE TROUGH WILL DIG SEWD ACROSS THE NRN PLAINS INTO NEB BY THE BEGINNING OF THE DAY2 PERIOD. THIS FEATURE WILL BE RESPONSIBLE FOR ENHANCING LOW LEVEL WARM ADVECTION/ELEVATED THUNDERSTORM CLUSTERS THURSDAY NIGHT INTO FRIDAY MORNING ACROSS MUCH OF THE CNTRL PLAINS REGION. DAY2 SEVERE THREAT WILL BE SOMEWHAT MODULATED BY THE MAGNITUDE OF DAY1 CONVECTION OVER THE OH/MID MS VALLEY REGION AND ITS ABILITY TO FORCE SFC BOUNDARY SWD TO A POSITION ARCING FROM THE LOWER OH RIVER...IL/IND/KY...INTO SERN KS. IT APPEARS EARLY MORNING MCS OVER NEB/KS WILL PROPAGATE SEWD ALONG THE AFOREMENTIONED LOW LEVEL CONVERGENCE ZONE...AIDED BY PROGRESSIVE SHORTWAVE TROUGH. WHETHER THE EARLY MORNING ACTIVITY MAINTAINS ITS INTENSITY OR REDEVELOPS DURING THE HEAT OF THE DAY IS NOT COMPLETELY CLEAR AT THIS TIME. NWRN PORTIONS OF THE SLGT RISK ARE PREDICATED ON MCS MAINTAINING ITS STRUCTURE/INTENSITY THROUGH THE EARLY MORNING. STRONG DOWNSTREAM HEATING WILL AID INSTABILITY FOR ADDITIONAL DEVELOPMENT ACROSS MO/AR INTO KY/TN BY MID/LATE AFTERNOON. ALTHOUGH THIS CONVECTION WILL GRADUALLY MOVE AWAY FROM STRONGER MID-HIGH LEVEL FLOW...IT APPEARS SUFFICIENT LARGE SCALE FORCING WILL SPREAD INTO THIS REGION FOR RENEWED CONVECTIVE DEVELOPMENT AS UPPER TROUGH AXIS DIGS SEWD. STRONG WINDS ARE THE MOST LIKELY SEVERE THREAT WITH THIS ACTIVITY. ...NEW ENGLAND... TROPICAL STORM BERYL IS EXPECTED TO REMAIN OFF THE NEW ENGLAND COAST THROUGH THE PERIOD. THIS STORM TRACK SHOULD MINIMIZE LOW LEVEL CONVERGENCE/INSTABILITY ALONG THE IMMEDIATE COAST. HOWEVER...FARTHER INLAND BOUNDARY LAYER LAPSE RATES SHOULD STEEPEN ACROSS UPSTATE NY INTO VT AS SFC TEMPERATURES WARM AHEAD OF SFC FRONT. DEEP LAYER SHEAR WILL GRADUALLY INCREASE AS UPPER TROUGH APPROACHES. STRONGER STORMS THAT FORM WITHIN THIS ENVIRONMENT MAY PRODUCE GUSTY WINDS OR PERHAPS SOME HAIL. WILL HOLD OFF ON ADDING A SLIGHT RISK AT THIS TIME UNTIL INFLUENCE OF BERYL ON THERMODYNAMIC ENVIRONMENT IS MORE CLEAR. ..DARROW.. 07/20/2006  From swody2 at goshenarc.org Sat Jul 22 05:58:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 22 Jul 2006 01:58:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220555 SWODY2 SPC AC 220554 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT SAT JUL 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN CAROLINAS AND SERN VA... ...SYNOPSIS... THE UPPER IMPULSE EXPECTED TO REACH THE MID-ATLANTIC STATES SATURDAY WILL EJECT NEWD INTO SERN CANADA ON SUNDAY. THE PRIMARY LONGWAVE TROUGH WILL GRADUALLY LIFT NEWD AS WELL AS THE NEXT DISTURBANCE DIGS SEWD INTO THE UPPER GRTLKS/NWRN ONT. MEANWHILE...THE UPPER HIGH WILL CONTINUE OVER THE WRN STATES WITH A CENTER OVER THE ERN UT. IN THE LWR LEVELS...THE COLD FRONT SITUATED ALONG THE APPALACHIANS WWD INTO THE SRN HIGH PLAINS WILL STALL LATE SATURDAY AS IT BECOMES PARALLEL WITH THE SWLY FLOW ALOFT. A NEW FRONT WILL MOVE QUICKLY SEWD FROM THE CANADIAN PRAIRIES TO THE UPPER GRTLKS AND UPPER MS VLY BY 12Z MON. ...ERN CAROLINAS AND SERN VA... PRIMARY FORCING FOR ASCENT ASSOCIATED WITH THE LEAD MID-LEVEL IMPULSE WILL BEGIN TO PULL AWAY FROM THE MID-ATLANTIC REGION EARLY SUNDAY. BUT...THE FLOW WILL REMAIN CYCLONIC ALOFT FOR THE MAJORITY OF THE AFTN FROM SC NWD AS THE PRIMARY LONGWAVE TROUGH LAGS. THERE WILL LIKELY BE BANDS OF CONVECTION ALONG/AHEAD OF THE FRONT THAT MAY WEAKEN/SHIFT EWD BY AFTN. IF SUFFICIENT INSOLATION CAN BE REALIZED IN WAKE OF THIS PCPN...TSTMS COULD DEVELOP OVER THE MOUNTAINS OF NC/SC DURING PEAK HEATING. HIGH PRECIPITABLE WATER VALUES AND MODEST MID-LEVEL WLY FLOW OF 30-35 KTS WILL BE FAVORABLE FOR A FEW ORGANIZED STORMS. DAMAGING WINDS WILL BE THE PRIMARY THREAT. ACTIVITY SHOULD SHIFT TOWARD THE COAST OVERNIGHT AND LIKELY WEAKEN AFTER SUNSET. ...SERN STATES/GULF COASTAL REGION... AIR MASS ALONG/S OF THE SYNOPTIC FRONT WILL REMAIN QUITE MOIST AND UNSTABLE SUNDAY AFTN/EVE. AMBIENT FLOW WILL BE WEAK AND MID-LEVEL LAPSE RATES WILL BE POOR OWING TO WARM TROPOSPHERE. WEAK CINH AND LOCALIZED CONVERGENCE/HEATING...HOWEVER...WILL BE FAVORABLE FOR TSTMS. ISOLD TSTMS MAY PRODUCE A DAMAGING WIND GUST...BUT WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. ...UPPER GRTLKS...NRN MN AND NERN ND... NEXT IN A SERIES OF UPPER DISTURBANCES WILL TRANSLATE QUICKLY SEWD WITHIN NWLY FLOW REGIME TO NWRN ONT/UPPER GRTLKS REGION BY LATE SUNDAY. A PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL STREAM EWD AHEAD OF THE FRONT ATOP SFC DEW POINTS IN THE LWR-MID 60S. THIS WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR TSTMS ALONG/AHEAD OF THE FRONT. INCREASING WNWLY UNIDIRECTIONAL FLOW REGIME WILL BE FAVORABLE FOR FAST MOVING TSTM LINE SEGMENTS THAT COULD GIVE ISOLD DAMAGING WIND GUSTS. ...SRN PLATEAU/FOUR CORNERS REGION... JETSTREAK WITHIN THE SUBTROPICAL JET ROUNDING THE PERIPHERY OF THE UPPER HIGH...WILL MOVE FROM CO THROUGH NM INTO AZ SUN AFTN/NIGHT. TSTMS WILL DEVELOP OVER THE HIGHER TERRAIN AND LIKELY BE ENHANCED BY THE DISTURBANCE. STORMS WILL PROPAGATE SWWD WITHIN THE 30-40 KT MID-LEVEL FLOW REGIME WITH THE RISK OF ISOLD SEVERE WIND GUSTS. STORMS THAT DEVELOP OVER THE MOGOLLON RIM COULD MOVE INTO THE LWR DESERTS BY EVENING BEFORE WEAKENING. ..RACY.. 07/22/2006  From swody2 at goshenarc.org Sat Jul 22 17:07:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 22 Jul 2006 13:07:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221703 SWODY2 SPC AC 221702 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 PM CDT SAT JUL 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CHESAPEAKE BAY INTO PARTS OF THE CAROLINAS... ...SYNOPSIS... ERN U.S. TROUGH IS FORECAST TO WEAKEN AS IT LIFTS NEWD IN RESPONSE TO APPROACH OF UPSTREAM SHORT WAVE TROUGH MOVING THROUGH ONTARIO. IN THE W...SOME FLATTENING OF RIDGE WILL OCCUR ACROSS THE PACIFIC NW INTO NRN ROCKIES WITH MID-LEVEL HIGH REMAINING ANCHORED OVER THE GREAT BASIN. IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH WEAKENING TROUGH WILL DEVELOP NEWD FROM ME INTO THE CANADIAN MARITIMES WITH TRAILING COLD FRONT PUSHING OFF THE NEW ENGLAND AND MIDDLE ATLANTIC COASTS. FARTHER TO THE S...FRONT WILL BE SLOWER TO PUSH EWD FROM CHESAPEAKE BAY SWD THROUGH THE PIEDMONT AND COASTAL PLAIN. A SECONDARY COLD FRONT WILL PUSH SWD INTO THE N-CNTRL TIER OF STATES IN ASSOCIATION WITH ONTARIO IMPULSE. ...CHESAPEAKE BAY INTO THE CAROLINAS... AS MENTIONED ABOVE...SURFACE FRONT WILL BE SLOW TO SHIFT EWD THROUGH THE PERIOD OWING TO WEAKENING LARGE-SCALE FORCING AND INCREASINGLY PARALLEL ORIENTATION OF BOUNDARY TO MID AND UPPER-LEVEL FLOW FIELDS. PRE-FRONTAL AIR MASS WILL REMAIN QUITE MOIST WITH DEWPOINTS IN THE UPPER 60S TO LOW/MID 70S...AND WHEN COUPLED WITH DIABATIC HEATING...BOUNDARY LAYER WILL BECOME MODERATELY UNSTABLE BY AFTERNOON WITH MLCAPES OF 1000-2500 J/KG. NEUTRAL TO SLIGHT HEIGHT RISES DURING TIME OF PEAK HEATING WOULD SUGGEST THAT LARGE-SCALE FORCING WILL REMAIN QUITE NEGLIGIBLE...AND THAT TSTM DEVELOPMENT WILL LIKELY BE DRIVEN BY A WEAK CAP AND LOW-LEVEL CONVERGENCE ALONG FRONTAL ZONE. DESPITE NEAR MOIST ADIABATIC MID-LEVEL LAPSE RATES...THE PRESENCE OF MODESTLY STRONG /30-35 KT/ MID-LEVEL FLOW...THE MODERATE INSTABILITY AND RELATIVELY STEEP LOW-LEVEL LAPSE RATES...SCATTERED SEVERE STORMS WILL BE POSSIBLE WITH THE PRIMARY SEVERE WEATHER THREAT BEING LOCALLY DAMAGING WINDS. STORMS SHOULD TEND TO WEAKEN BY MID TO LATE EVENING AS BOUNDARY LAYER SLOWLY STABILIZES. ...UPPER MS VALLEY INTO NRN HIGH PLAINS... BOUNDARY LAYER MOISTURE WILL REMAIN QUITE LIMITED AHEAD OF COLD FRONT MOVING SWD OUT OF CANADA WITH DEWPOINTS IN THE 40S TO PERHAPS LOW/MID 50S. HOWEVER...FORECAST SOUNDINGS INDICATE THE PRESENCE OF RELATIVELY STEEP LOW TO MID-LEVEL LAPSE RATES WHICH WILL LARGELY CONTRIBUTE TO MLCAPES OF 500-1000 J/KG. STORMS WILL LIKELY DEVELOP NEAR OR JUST N OF THE INTERNATIONAL BORDER DURING THE LATE AFTERNOON OR EARLY EVENING HOURS ALONG OR SLIGHTLY BEHIND SURFACE FRONT. ACTIVITY SHOULD THEN MOVE/DEVELOP SWD INTO NRN MN...ND AND MT SUNDAY EVENING AND NIGHT WITH A THREAT OF ISOLATED SEVERE HAIL AND GUSTY WINDS. ...SRN ROCKIES INTO AZ DESERTS... ERN PERIPHERY OF WRN U.S. HIGH IS FORECAST TO BE CONVECTIVELY ACTIVE SUNDAY AFTERNOON AND EVENING OWING STRONG HEATING ALONG THE ELEVATED TERRAIN AND THE SUBTLE INFLUENCE OF WEAK IMPULSES EMBEDDED IN LARGER-SCALE CIRCULATION. STRONG BOUNDARY LAYER HEATING/MIXING WILL RESULT IN A DEEP SUB-CLOUD LAYER WITH SBCAPES INCREASING TO 500-800 J/KG...WHICH WILL BE SUPPORTIVE OF ISOLATED SEVERE STORMS CAPABLE OF LOCALLY DAMAGING WINDS. A POTENTIALLY GREATER THREAT OF MORE ORGANIZED STORMS CAPABLE OF DAMAGING WINDS WILL EXIST FROM ERN AZ INTO THE LOWER DESERTS WHERE DEEPER 20-30 KT NELY/ELY SHEAR WILL FAVOR COLD POOL ORGANIZATION WITH ANY STORM CLUSTERS MOVING OFF THE MOGOLLON RIM. ..MEAD.. 07/22/2006  From swody2 at goshenarc.org Sun Jul 23 05:57:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 23 Jul 2006 01:57:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230554 SWODY2 SPC AC 230553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT SUN JUL 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY AND CNTRL GRTLKS REGION... ...SYNOPSIS... A GRADUAL TREND TOWARD A MORE ZONAL FLOW REGIME WILL OCCUR ON MON AS THE UPPER HIGH OVER THE WRN STATES BUILDS EWD AND THE NERN TROUGH BEGINS TO FILL. A STRONG SHORTWAVE TROUGH THAT WILL MOVE INTO NWRN ONT EARLY MON WILL TRANSLATE TO SRN QUE BY 12Z TUE. A SEPARATE BUT WEAKER JET STREAM WILL CARRY OTHER DISTURBANCES SEWD FROM THE DAKS INTO THE UPPER MS VLY AND UPPER MIDWEST...ALONG NRN PERIPHERY OF THE UPPER HIGH. ...UPPER MS VLY TO THE CNTRL GRTLKS REGION... A COLD FRONT ASSOCIATED WITH THE CANADIAN SHORTWAVE TROUGH WILL MOVE SEWD THROUGH THE CNTRL GRTLKS...UPPER MS VLY AND NRN PLAINS THROUGH MON AFTN. A WARM FRONT WILL GRADUALLY SHIFT NEWD THROUGH THE CNTRL GRTLKS. MORNING ELEVATED CONVECTION WILL LIKELY BE ONGOING ACROSS PARTS OF THE CNTRL GRTLKS AS THE WARM/MOIST AIR MASS RETURNS EWD ACROSS THE REGION. THIS PLACES SOME UNCERTAINTY ON THE MAGNITUDE OF PRE-FRONTAL HEATING/DESTABILIZATION LATER ON MON. BUT...A WLY FLOW REGIME ALOFT WILL ADVECT STEEP MID-LEVEL LAPSE RATES EWD FROM THE PLAINS AND LIKELY CONTRIBUTE TO THE POTENTIAL INSTABILITY. IF ENOUGH HEATING CAN BE REALIZED...SFC-BASED CONVECTION MAY EVOLVE DURING THE AFTN ALONG/AHEAD OF THE FRONT FROM PARTS OF ERN UPPER/NRN-CNTRL LWR MI WWD INTO WI AND ECNTRL MN. STRONGER TSTMS ARE EXPECTED ALONG THE WRN/SRN PARTS OF THE FRONT WHERE MID-LEVEL LAPSE RATES WILL BE STEEPER. VERTICAL SHEAR WILL NOT BE PARTICULARLY STRONG...BUT THE UNIDIRECTIONAL NATURE OF THE WNWLY FLOW WILL BE FAVORABLE FOR DAMAGING WIND GUSTS ALONG WITH LARGE HAIL. ISOLD TORNADOES MAY BE POSSIBLE ACROSS PORTIONS OF MI VCNTY THE WARM FRONT WHERE THE BOUNDARY LAYER WINDS FLOW WILL BE MOVE SLY BENEATH WLY FLOW ALOFT. ...CNTRL PLAINS... ELEVATED MIXED LAYER WILL BECOME STRONGER THROUGH MON ACROSS THE PLAINS AS THE UPPER RIDGE BUILDS EWD. BUT...THE BOUNDARY LAYER IS EXPECTED TO HEAT CONSIDERABLY VCNTY A LEE-TROUGH THAT WILL MOVE INTO PARTS OF SCNTRL SD AND NCNTRL NEB MON AFTN/EVE. LOCALIZED CONVERGENCE AND HEATING MAY CONTRIBUTE TO ISOLD HIGH-BASED TSTM DEVELOPMENT VCNTY THIS TROUGH. VERTICAL SHEAR WILL BE SOMEWHAT WEAK...ON THE ORDER OF 30-35 KTS. BUT...COUPLED WITH THE VERY STEEP LAPSE RATE ENVIRONMENT...ISOLD SUPERCELLS MAY BE POSSIBLE GIVING MAINLY LARGE HAIL AND PERHAPS A DAMAGING WIND GUST. ACTIVITY MAY CONGEAL INTO A WEAKLY ORGANIZED MCS OVERNIGHT MON AS THE LLJ INCREASES ACROSS THE PLAINS. THIS ACTIVITY MAY POSE A HAIL RISK. ...SRN PLATEAU/DESERT SW... ANOTHER ROUND OF DIURNAL TSTMS ARE EXPECTED ACROSS THE HIGHER TERRAIN OF THE SRN PLATEAU/DESERT SW MONDAY AFTN/EVE. MID-LEVEL FLOW SHOULD BEGIN TO SLACKEN OWING TO STRENGTHENING UPPER RIDGE AXIS. BUT...STEEP LOW-LEVEL LAPSE RATES WILL ENCOURAGE GUSTY WINDS/ISOLD SEVERE WIND GUSTS WITH THE STRONGER STORMS. ..RACY.. 07/23/2006  From swody2 at goshenarc.org Sun Jul 23 17:26:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 23 Jul 2006 13:26:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231722 SWODY2 SPC AC 231721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SUN JUL 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE UPPER GREAT LAKES WWD INTO ERN SD... ...SYNOPSIS... FLATTENING OF SWRN U.S. RIDGE IS FORECAST DURING THE DAY TWO PERIOD OWING TO THE TRANSLATION OF WEAK IMPULSES FROM THE PACIFIC NW AND NRN ROCKIES INTO THE NRN PLAINS. IN THE NE...HEIGHTS WILL REBOUND IN WAKE OF SHORT WAVE TROUGH LIFTING NEWD INTO THE CANADIAN MARITIMES. IN THE LOW-LEVELS...A COLD FRONT ASSOCIATED WITH A SHORT WAVE TROUGH MOVING THROUGH ONTARIO WILL PUSH SEWD INTO THE UPPER GREAT LAKES WITH THIS BOUNDARY EXTENDING WWD TO DEVELOPING LOW PRESSURE OVER SD. MEANWHILE IN THE SE...REMNANT BOUNDARY FROM THE NC COAST INTO THE NWRN GULF OF MEXICO WILL WEAKEN THROUGH THE PERIOD. ...UPPER GREAT LAKES INTO NRN PLAINS... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING MONDAY MORNING OVER PARTS OF WI INTO THE UP MI WITHIN LOW-LEVEL WAA REGIME ASSOCIATED WITH SHORT WAVE TROUGH MOVING THROUGH ONTARIO. WHILE SOME HAIL WILL BE POSSIBLE WITH THESE STORMS THROUGH THE MORNING HOURS...THIS ACTIVITY SHOULD GENERALLY MOVE EWD INTO SWRN ONTARIO BY AFTERNOON. ADDITIONAL...DIURNAL STORM DEVELOPMENT WILL BE POSSIBLE BY AFTERNOON ALONG COLD FRONT PUSHING SEWD INTO REGION FROM LOWER MI WWD THROUGH WI...CNTRL/SRN MN AND ERN SD. LATEST MODEL GUIDANCE SUGGESTS THAT MODEST BOUNDARY LAYER MOISTURE /DEWPOINTS OF 55-65 F...DECREASING TO GENERALLY 50S WWD OVER SD/ COUPLED WITH STEEP LOW TO MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO MODERATE INSTABILITY BY AFTERNOON WITH MLCAPES OF 1000-2000 J/KG. THE STRONGEST VERTICAL SHEAR IS FORECAST TO EXIST IN CLOSER PROXIMITY TO ONTARIO IMPULSE N OF THE INTERNATIONAL BORDER...AND TO THE W OVER WRN/CNTRL SD WITH GENERALLY 25-35 KTS OF DEEP-LAYER SHEAR EXPECTED ACROSS SLIGHT RISK PORTION OF FRONTAL ZONE. SURFACE-BASED TSTMS WILL BECOME INCREASINGLY LIKELY BY AFTERNOON ALONG FRONT OWING TO GLANCING INFLUENCE OF ONTARIO SHORT WAVE TROUGH AND INCREASED LARGE-SCALE FORCING ASSOCIATED WITH WEAKER UPSTREAM IMPULSE MOVING THROUGH THE NRN PLAINS. STORMS SHOULD REMAIN LARGELY MULTICELLULAR FROM LOWER MI WWD INTO MN WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS. DESPITE WEAKENING INSTABILITY WITH WWD EXTENT INTO SD...POTENTIAL WILL EXIST FOR A COUPLE OF HIGH-BASED MARGINAL SUPERCELLS...SUPPORTED BY THE STEEP LAPSE RATES AND AROUND 35 KTS OF DEEP-LAYER SHEAR. THESE STORMS WILL ALSO BE CAPABLE OF LOCALLY HIGH WINDS AND HAIL. ...NRN HIGH PLAINS... A FEW HIGH-BASED STRONG TO MARGINALLY SEVERE STORMS WILL BE POSSIBLE MONDAY AFTERNOON AND EVENING ALONG WRN EXTENSION OF FRONTAL BOUNDARY OVER MT. LOW-LEVEL MOISTURE WILL REMAIN LIMITED...THOUGH THE PRESENCE OF STEEP LAPSE RATES WILL SUPPORT MARGINAL INSTABILITY. FORECAST SOUNDINGS INDICATE THAT VERTICAL SHEAR WILL BE SUFFICIENT FOR SOME STORM ORGANIZATION WITH A THREAT OF ISOLATED STRONG WINDS/SEVERE HAIL. ...CNTRL ROCKIES TOWARD THE LOWER CO VALLEY... DIURNAL TSTMS ARE EXPECTED TO DEVELOP ALONG THE HIGHER TERRAIN AROUND PERIPHERY OF FLATTENING MID-LEVEL RIDGE MONDAY AFTERNOON AND EVENING. A SHORT WAVE TROUGH MOVING SWD THROUGH CO WILL LIKELY FOCUS A MORE CONCENTRATED CLUSTER OF STORMS FROM S-CNTRL CO INTO CNTRL NM...WITH MORE WIDELY SCATTERED DEVELOPMENT ANTICIPATED ALONG OROGRAPHICALLY FAVORED AREAS. DEEP BOUNDARY LAYER MIXING WILL RESULT IN THE DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND STRONG EVAPORATIONAL COOLING POTENTIAL IN THE SUB-CLOUD LAYER WITH LOCALLY DAMAGING WINDS POSSIBLE WITH THE STRONGEST STORMS. ...SRN ATLANTIC COAST... RICH BOUNDARY LAYER MOISTURE COUPLED WITH DAYTIME HEATING ARE EXPECTED TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS MONDAY TO THE S OF WEAKENING FRONTAL ZONE WITH MLCAPES INCREASING TO 1500-2500 J/KG. LITTLE OR NO CONVECTIVE INHIBITION SHOULD ALLOW TSTMS TO BECOME FAIRLY WIDESPREAD ACROSS THE REGION BY PEAK HEATING WITH THE POTENTIAL FOR ISOLATED...SEVERE WET MICROBURSTS. ..MEAD.. 07/23/2006  From swody2 at goshenarc.org Mon Jul 24 06:06:55 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 24 Jul 2006 02:06:55 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240603 SWODY2 SPC AC 240603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0103 AM CDT MON JUL 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NRN NEW ENGLAND... ...SYNOPSIS... THE WRN STATES UPPER RIDGE WILL EXPAND TO THE N AND E ACROSS THE SRN AND CNTRL PARTS OF THE COUNTRY ON TUE AS THE PRIMARY BELT OF WLYS BECOMES SITUATED ALONG THE INTERNATIONAL BORDER. A MID-LEVEL SHORTWAVE TROUGH THAT WILL REACH SRN QUE BY EARLY TUE WILL EJECT NEWD INTO ATLANTIC CANADA BY TUE EVE...SKIRTING PARTS OF NRN NEW ENGLAND. MEANWHILE...A SECONDARY DISTURBANCE WILL MOVE QUICKLY SEWD THROUGH THE NRN PLAINS TO THE UPPER MS VLY DURING THE DAY TUE. ...NRN NEW ENGLAND... THE SRN QUE H5 SHORTWAVE TROUGH WILL GLANCE ACROSS NRN NEW ENGLAND DURING TUE AFTN WITH ASSOCIATED 40-50 KT JET...BOOSTING VERTICAL SHEAR VALUES. AIR MASS SHOULD GRADUALLY MOISTEN...BUT RECENT INTRUSION OF A CP AIR MASS WILL LIKELY SLOW THE RETURN OF QUALITY MOISTURE. THIS...AND THE FACT THAT MID-TROPOSPHERIC LAPSE RATES WILL GENERALLY BE BELOW 6 DEG C PER KM...SUGGEST THAT INSTABILITY WILL BE MODEST AT BEST. BUT...GIVEN MAGNITUDE OF ASCENT AND SHEAR IN PLACE DURING PEAK HEATING...A FEW TSTMS WILL LIKELY PRODUCE DAMAGING WIND GUSTS...PRIMARY OVER NRN MAINE. ...SWRN DESERTS... EMILIA IS EXPECTED TO BECOME A HRCN AND MOVE JUST OFF THE WRN BAJA COAST THROUGH TUE. CLIMATOLOGICALLY...SIGNIFICANT GULF OF CA SURGES OCCUR WHEN A TROPICAL SYSTEM TAKES A PATH SIMILAR TO EMILIA. THIS WILL LIKELY CAUSE AN DRAMATIC INCREASE IN BOUNDARY LAYER MOISTURE ACROSS THE LWR DESERT REGIONS BY TUE AFTN/EVE AND COULD PLAY A ROLE IN AN INCREASE IN TSTMS PROBABILITIES. MODELS SUGGEST THAT NELY FLOW WILL INCREASE TO AOA 30 KTS AS THE BOUNDARY LAYER FLOW REMAINS UPSLOPE DURING PEAK HEATING. AS A RESULT...TSTMS COULD STRONGLY PROPAGATE INTO THE LWR DESERTS DURING THE AFTN/EVE WITH DAMAGING WINDS AND HAIL. TYPICALLY... MESOSCALE PROCESSES...WHICH ARE DIFFICULT TO PIN-POINT THIS FAR IN ADVANCE ACROSS THE SWRN STATES...DICTATE STORM MODE AND EVOLUTION. AS SUCH...A CATEGORICAL SLGT RISK IS NOT WARRANTED ATTM. BUT... THE REGION MAY NEED HIGHER SEVERE PROBABILITIES IN FUTURE OTLKS. ...UPPER MS VLY/CORN BELT... DIFFICULT FORECAST CONTINUES WITH RESPECT TO SEVERE TSTM PROBABILITIES ACROSS THE REGION. PRIMARY FORCING FOR ASCENT WILL BE PULLING NEWD AWAY FROM THE REGION EARLY ON TUE AS THE STRONGER SHORTWAVE TROUGH MOVES TO SERN CANADA. THE LOW-LEVEL FLOW...HOWEVER...SHOULD REMAIN SWLY...MAXIMIZING WARM ADVECTION REGIME DOWNSTREAM FROM STRONGER ELEVATED MIXED LAYER ACROSS THE MO VLY. AS A RESULT...CONVECTION/TSTMS WILL LIKELY DEVELOP THROUGHOUT THE DAY FROM PARTS OF IA/SRN WI EWD TOWARD MI...OR WITHIN/NE OF THE STRONGER LOW-LEVEL THERMAL AXIS. VERTICAL SHEAR WILL REMAIN WEAK AND SUGGESTS THAT THE SEVERE PROBABILITIES WILL REMAIN LOW...ESPECIALLY IF SFC RIDGING BECOMES AS STRONG AS THE 00Z NAM SUGGESTS. FARTHER NW...A SEPARATE REGION OF SLIGHTLY HIGHER SEVERE PROBABILITIES WILL EXIST ACROSS NRN/CNTRL MN TOWARD THE UPPER GRTLKS. THIS REGION WILL BE DOWNSTREAM FROM A WEAK IMPULSE. 00Z MODEL SUITE DIFFER IN MAGNITUDE OF THIS WAVE. GIVEN THAT THE NAM IS AN OUTLIER...HAVE GIVEN CREDENCE TO THE GFS/ECMWF IN A WEAKER WAVE. TSTMS WILL STILL REMAIN POSSIBLE...ALONG/AHEAD OF THE ASSOCIATED COLD FRONT...BUT RELATIVELY WARMER MID-LEVEL TEMPERATURES MAY TEND TO BE DETRIMENTAL TO WIDESPREAD TSTM INITIATION. GIVEN A SUSTAINED STORM...THE MAGNITUDE OF LAPSE RATES AND AT LEAST MODEST VERTICAL SHEAR WILL BE FAVORABLE FOR ISOLD LARGE HAIL. ...CNTRL PLAINS... HIGH-BASED TSTMS WILL LIKELY DEVELOP TUE AFTN/EVE ALONG/AHEAD OF A LEE-TROUGH FROM ERN CO NEWD INTO NCNTRL NEB. THIS REGION WILL RESIDE ALONG THE SRN PERIPHERY OF THE UPPER MS VLY IMPULSE WITH MODEST NWLY FLOW ALOFT. GIVEN THE SLY LOW-LEVEL FLOW...SUFFICIENT DIRECTIONAL SHEAR MAY EXIST FOR ISOLD ORGANIZED STORMS THAT PRODUCE LARGE HAIL/DAMAGING WIND GUSTS. ACTIVITY MAY DEVELOP INTO A LOOSELY ORGANIZED MCS THAT WILL MOVE EWD INTO THE CORN BELT OVERNIGHT TUE. ...SERN TX... TROPICAL AIR MASS WILL CONTINUE TO FLOW NWD ALONG ERN SIDES OF THE UPPER LOW EXPECTED TO MIGRATE NWD INTO THE REGION ON TUE. RESIDUAL FRONT AND DEEPENING SFC LOW WILL MAINTAIN AN ESELY BOUNDARY LAYER FLOW. AS A RESULT...TSTMS THAT DEVELOP AND MOVE NWD MAY PRODUCE ISOLD TORNADOES...ESPECIALLY AS THEY APPROACH THE OLD FRONT ACROSS PORTIONS OF SERN TX. ..RACY.. 07/24/2006  From swody2 at goshenarc.org Mon Jul 24 17:17:15 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 24 Jul 2006 13:17:15 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241712 SWODY2 SPC AC 241711 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1211 PM CDT MON JUL 24 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS DURING THE AFTERNOON OVER EXTREME NRN MAINE.... ...SYNOPSIS... MID/UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE SOUTHWEST QUARTER OF THE U.S. FIRST MID/UPPER LEVEL SHORTWAVE TROUGH NOW OVER ONTARIO IS FORECAST TO MOVE EWD INTO QUEBEC THEN LIFT NNEWD SKIRTING WRN AND NRN EDGES OF MAINE TUESDAY AFTERNOON. SECOND SHORTWAVE TROUGH NOW OVER WRN SASKATCHEWAN IS EXPECTED TO MOVE ACROSS THE NRN PLAINS AND UPPER MIDWEST DURING THE SECOND HALF OF THE PERIOD. FINALLY...MID/UPPER LEVEL TROUGH OVER NERN SECTIONS OF MEXICO IS PROGGED TO INTENSIFY SLIGHTLY AND BECOME A CLOSED LOW OVER SOUTH CENTRAL TEXAS BY THE END OF THE PERIOD. ...NRN PARTS OF MAINE... ANALYSIS OF NAM...GFS AND NMM-WRF MODELS REVEAL MORE NEGATIVES THAN POSITIVES FOR SEVERE POTENTIAL ACROSS THIS AREA. THE SHORT RANGE ENSEMBLE SEEMS TO BE THE SOLUTION THAT IS A LITTLE MORE AGGRESSIVE DETAILING A 30 PERCENT PROBABILITY FOR SUPERCELLS AS IT BANKS ON THE FAVORABLE SHEAR PROFILES IN THE FORECAST SOUNDINGS. GIVEN THAT THE INDIVIDUAL MODELS ARE TAKING THE SHORTWAVE TROUGH INTO THE ST. LAWRENCE RIVER VALLEY IN SRN QUEBEC THEN LIFTING IT NNEWD DURING THE AFTERNOON...PLUS FORECAST SOUNDINGS ARE INDICATING PERSISTENT CLOUD COVER AS WELL AS LIMITED INSTABILITY /MLCAPE MAXING OUT AT 900 J/KG/ AND MOIST ADIABATIC LAPSE RATES OF 6C/KM...SEEMS THAT THE SEVERE POTENTIAL COULD BE MARGINAL AT BEST. COLD FRONTAL BOUNDARY ACCOMPANYING THE MID/UPPER LEVEL TROUGH LOOKS TO BECOME QUASISTATIONARY JUST WEST OF MAINE LEAVING A WEAKENING LINE OF THUNDERSTORMS TO MOVE OVER THE REGION TOMORROW. IF THERE IS ANY PROBABILITY FOR SEVERE...IT WILL BE STRONG WINDS OVER THE EXTREME NWRN AND NRN MAINE WHERE BEST DYNAMICS WILL BRUSH BY THE AREA. ...UPPER MIDWEST/WRN GREAT LAKES REGION... SECOND MID/UPPER LEVEL TROUGH WILL DROP SEWD INTO THE NRN PLAINS AND UPPER MIDWEST REGION DURING THE LATTER HALF OF THE PERIOD. THIS WILL BE ACCOMPANIED BY WEAK FRONTAL BOUNDARY/SURFACE TROUGH THAT WILL EXTEND FROM N CENTRAL MN SWWD INTO SWRN SD BY 12Z WEDNESDAY. MODELS DEPICT AREA OF SCATTERED THUNDERSTORMS WILL DEVELOP ALONG THE SURFACE TROUGH EARLY IN THE PERIOD THROUGH EARLY EVENING...GIVING WAY TO CLUSTER OF STORMS/MCS OVER WI/IA TUE NIGHT AND WED MORNING. STEEP LOW LEVEL LAPSE RATES JUST ABOVE 7.5C/KM INDICATES THAT SOME OF THE STORMS COULD PRODUCE STRONG DOWNBURSTS WITH PROBABILITIES DIMINISHING AFTER SUNSET. ...SOUTHWESTERN U.S.... PERSISTENCE INDICATES THAT SCATTERED STRONG THUNDERSTORMS COULD OCCUR ONCE AGAIN ACROSS THE REGION. ELY MID LEVEL FLOW WILL CONTINUE ACROSS AZ AND PARTS OF NM WITH VERY STEEP LAPSE RATES BELOW 600 MB. THIS ALONG WITH VERY HIGH DCAPE VALUES OVER 1000 J/KG INDICATES THE THREAT FOR STRONG DOWNBURSTS WITH SCATTERED AFTERNOON/EVENING THUNDERSTORMS. ...SOUTH CENTRAL TEXAS EWD INTO LOWER MS VALLEY... MID/UPPER LEVEL LOW IS FORECAST TO DEVELOP OVER S CENTRAL TX DURING THE PERIOD. AIR MASS WILL REMAIN VERY WARM AND MOIST WITH MOIST ADIABATIC LAPSE RATES AND LIMITED INSTABILITY WITH MOST UNSTABLE CAPES BETWEEN 500 AND 800 J/KG. SHEAR PROFILES INCREASE ACROSS S CENTRAL TX AS LOW DEVELOPS INDICATING THE POSSIBILITY OF ISOLATED SUPERCELLS LATE IN THE PERIOD. ..MCCARTHY.. 07/24/2006  From swody2 at goshenarc.org Tue Jul 25 05:58:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 25 Jul 2006 01:58:42 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250554 SWODY2 SPC AC 250553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT TUE JUL 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL GRTLKS AND UPPER MS VLY REGIONS... ...SYNOPSIS... MID-WEEK UPPER FLOW REGIME WILL MAINTAIN A BROAD UPPER HIGH ACROSS THE SWRN STATES WITH A CENTER OVER THE GRT BASIN REGION. A LARGELY ZONAL PATTERN WILL EXIST ACROSS SRN CANADA AND THE EXTREME NRN PARTS OF THE UNITED STATES. THIS JET STREAM WILL CARRY NUMEROUS SHORTWAVE TROUGHS ACROSS THE NRN TIER OF THE COUNTRY. TWO FEATURES OF NOTE WILL LIKELY MODULATE THE POTENTIAL FOR SEVERE WEATHER. ONE WILL BE A FAIRLY STRONG MID-LEVEL IMPULSE...NOW EVOLVING OVER SRN CANADA. THIS FEATURE WILL MOVE ACROSS THE UPPER MS VLY/GRT LKS REGION ON WED. A SECOND WEAKER SHORTWAVE TROUGH WILL MOVE SEWD ACROSS MT BY WED EVE. AT THE SFC...A COLD FRONT ACCOMPANYING THE LEAD WAVE WILL MOVE SEWD ACROSS THE UPPER MS VLY AND TO THE CNTRL GRTLKS REGION BY 12Z THU. TAIL END OF THIS FRONT WILL REDEVELOP QUICKLY NWD ACROSS THE HIGH PLAINS DURING THE PERIOD. A WEAK LEE-TROUGH WILL EXIST ACROSS THE CNTRL PLAINS AND CORN BELT. ...CNTRL GRTLKS SWWD TO THE CNTRL PLAINS... CONVECTION...LIKELY SUB-SEVERE...WILL BE ONGOING EARLY WED MORNING ACROSS PARTS OF THE CNTRL GRTLKS SWWD INTO THE CORN BELT. THIS ACTIVITY WILL BE KEPT ALIVE THROUGH THE MORNING BY A WEAKENING SWLY LLJ AXIS THAT WILL SHIFT NEWD INTO SRN ONT BY MID-DAY. IN WAKE OF THE MORNING ACTIVITY...THE PRE-FRONTAL AIR MASS IS LIKELY TO BECOME QUITE UNSTABLE OWING TO THE GRADUAL MOISTENING OF THE BOUNDARY LAYER AND VERY STEEP MID-TROPOSPHERIC LAPSE RATES. THE PRIMARY FORCING FOR ASCENT ASSOCIATED WITH THE UPPER WAVE WILL LIKELY BE PASSING ACROSS THE INSTABILITY AXIS BY EARLY AFTN...WITH TSTMS LIKELY DEVELOPING ALONG/AHEAD OF THE COLD FRONT FROM PARTS OF UPPER MI TO NERN IA. VERTICAL SHEAR WILL GENERALLY BE LESS THAN 30-35 KTS...BUT EXPECTED MAGNITUDE OF LAPSE RATES AND MODEST VEERING WINDS WITH HEIGHT SUGGEST THAT SUPERCELLS WILL BE POSSIBLE WITH LARGE HAIL...DAMAGING WINDS AND POSSIBLY AN ISOLD TORNADO. ACTIVITY SHOULD MOVE EWD DURING THE EVENING INTO THE CNTRL GRTLKS REGION AND LIKELY WEAKEN AFTER DARK AS THEY MOVE INTO A MORE STABLE ENVIRONMENT. A SEPARATE REGION OF ENHANCED CONVECTION WILL LIKELY FAVOR PORTIONS OF THE CNTRL PLAINS EWD INTO PARTS OF NRN MO AND CNTRL IL WHERE A SECONDARY LOW-LEVEL THERMAL RIDGE SHOULD EXIST. THIS WILL BE JUST S OF MORNING CONVECTION AND AS THE BOUNDARY LAYER HEATS...LOCAL CONVERGENCE ALONG THE LEE-TROUGH AND/OR OUTFLOW BOUNDARIES MAY SERVE AS A FOCUS FOR TSTMS. THOUGH THE VERTICAL SHEAR THIS FAR S WILL BE MEAGER...LAPSE RATES WILL BE QUITE STEEP THROUGHOUT THE COLUMN AND ISOLD STORMS MAY PRODUCE LARGE HAIL OR DAMAGING WIND GUSTS. ...HIGH PLAINS... HIGH-BASED TSTMS WILL LIKELY DEVELOP ACROSS THE NRN HIGH PLAINS...DOWNSTREAM FROM THE WEAKER SECONDARY IMPULSE DROPPING ESEWD FROM THE SRN CANADIAN ROCKIES. A TONGUE OF INSTABILITY WILL LIKELY ARC NWWD ALONG/N OF THE RETREATING SFC BOUNDARY AND COUPLED WITH 35-40 KTS OF 6KM SHEAR SUGGEST THAT ISOLD ORGANIZED STORMS MAY EVOLVE FROM ERN MT INTO PARTS OF WRN ND WITH POSSIBLE HAIL AND GUSTY WINDS. OTHER STORMS WILL DEVELOP SWD ALONG THE ROCKIES DURING PEAK HEATING AND MAY POSE AN ISOLD DAMAGING WIND THREAT GIVEN THE TYPICAL STEEP LOW-LEVEL LAPSE RATES. ...SWRN DESERTS... HIGHER PWAT VALUES SHOULD BE WELL-ESTABLISHED ACROSS THE LWR DESERTS OWING TO HRCN EMILIA THAT WILL MOVE OFF THE WRN COAST OF BAJA THROUGH WED. DEPENDING ON HOW MUCH RESIDUAL CONVECTIVE DEBRIS IS IN PLACE ON WED...THERE COULD BE ANOTHER ROUND OF ORGANIZED TSTMS WED AFTN/EVE. IT APPEARS...THOUGH...THAT THE STRONGER ENELY FLOW WILL EXIST ACROSS SONORA. WILL MAINTAIN LOW SEVERE PROBABILITIES ATTM. ...MIDDLE/UPPER TX COAST... THERE IS A WIDE SPREAD AMONG THE MODELS IN HANDLING THE TROPICAL WAVE ACROSS THE WRN GULF BASIN. CONSENSUS SUGGESTS THAT THE STRONGEST CONVECTION SHOULD BE CONFINED TO THE COASTAL PLAINS AND OFFSHORE WATERS. FORECAST SOUNDINGS SHOW A HIGH PWAT AIRMASS WITH SUFFICIENT LOW-LEVEL SHEAR FOR PERHAPS AN ISOLD TORNADO OR DAMAGING WIND GUST. ..RACY.. 07/25/2006  From swody2 at goshenarc.org Tue Jul 25 17:02:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 25 Jul 2006 13:02:27 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 251659 SWODY2 SPC AC 251658 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1158 AM CDT TUE JUL 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NORTH CENTRAL GREAT LAKES.... ...SYNOPSIS... SEVERAL EMBEDDED MINOR SHORTWAVE TROUGHS WILL TRAVEL WITHIN MAIN BAND OF WESTERLIES THAT WILL EXTEND FROM MT THRU THR GREAT LAKES INTO NEW ENGLAND. LARGE MID/UPPER LEVEL RIDGE WILL DOMINATE THE GREAT BASIN AND SWRN STATES...AS WELL AS THE SERN STATES WHILE MID/UPPER LEVEL LOW MOVES NWD ACROSS PARTS OF CENTRAL/ERN TX. ...NORTH CENTRAL GREAT LAKES... MODELS INDICATE THAT MID/UPPER LEVEL TROUGH MOVING INTO THE UPPER MS RIVER VALLEY ON DAY1 WILL SWING EWD/NEWD EARLY IN THE PERIOD FROM ERN WI THRU LOWER MI BEFORE 27/0300Z. BAND OF THUNDERSTORMS ARE EXPECTED ALONG/AHEAD OF WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE TROUGH. DUE TO TIME OF DAY...EXPECT MUCH OF THIS ACTIVITY TO BE NEAR/BELOW SEVERE LEVELS DUE TO LIMITED THERMODYNAMICS. MODELS HINT AT A WEAK BOUNDARY THAT WILL EXTEND SWWD THOUGH FROM NRN INDIANA THRU IL INTO SRN IA. DAYTIME HEATING WILL DESTABILIZE THESE AREAS BY AFTERNOON AIDING IN THE INITIATION OF THUNDERSTORMS ACROSS THESE AREAS. TEMPERATURES AT 500 MB ARE EXPECTED TO REMAIN WARM AROUND -6C...THUS HAVE OPTED FOR A LOW OR ISOLATED PROBABILITY FOR SEVERE THUNDERSTORMS WITH THE POSSIBILITY OF SOME STRONG WIND GUSTS. CONCENTRATED MORE ON WHERE SRN PERIPHERY OF MID/UPPER LEVEL TROUGH WILL MOVE ACROSS UPPER MI/NERN WI AND NRN LOWER MI ON NRN FRINGES OF UNSTABLE AIR MASS WHERE 500 MB TEMPERATURES ARE -8C OR -10C. THIS AREA HAS SOME BETTER SHEAR WITH SWLY LOW LEVEL FLOW OF AROUND 50 KT COUPLED WITH WLY 500 MB FLOW OF 40-50 KT. EXPECT SECONDARY LINE OF STRONG/SEVERE THUNDERSTORMS TO DEVELOP WED AFTN INTO EARLY WED NIGHT WITH THE THREAT OF DAMAGING WINDS AND HAIL. ...PARTS OF CENTRAL AND ERN TX... TROPICAL MID/UPPER LEVEL LOW WILL MOVE NWD FROM THE TX GULF COAST TO AROUND THE DALLAS METROPLEX DURING THE PERIOD. LOW/MID LEVEL FLOW OF 30-40 KT IS FORECAST ON THE ERN SIDE OF THIS SYSTEM THRU ERN TX INTO WRN SECTIONS OF LA. THUS...THERE MAY BE SOME STRONG WIND GUSTS...BUT GIVEN THE MOIST ADIABATIC LAPSE RATES AND MINIMAL DIRECTIONAL SHEAR...ACTIVITY SHOULD REMAIN BELOW SEVERE LEVELS. ..MCCARTHY.. 07/25/2006  From swody2 at goshenarc.org Wed Jul 26 06:00:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 26 Jul 2006 02:00:24 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260557 SWODY2 SPC AC 260556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT WED JUL 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER FLOW PATTERN WILL BEGIN TO TRANSITION AGAIN ON THU AS AN UPPER TROUGH EVOLVES OFF THE PAC NW COAST...WITH A BROAD DOWNSTREAM TROUGH ACROSS THE MIDWEST. THE UPPER HIGH WILL REMAIN IN PLACE ACROSS THE SWRN DESERTS. STRONGEST WLYS WILL REMAIN ACROSS SRN CANADA...BUT A COUPLE OF MODEST SHORTWAVE TROUGHS WILL BE SKIRTING THE NRN TIER OF THE COUNTRY. LEAD IMPULSE WILL TRAVEL FROM THE CNTRL GRTLKS REGION NEWD INTO SRN QUE THU AFTN/NIGHT WHILE DEAMPLIFYING. A SECOND DISTURBANCE WILL MOVE SEWD INTO THE DAKS. THE TROPICAL WAVE MOVING NWD THROUGH THE WRN GULF OF MEXICO CURRENTLY SHOULD MOVE NWD AND COULD PHASE WITH THE NRN STREAM BY THU AFTN...THOUGH MODEL SOLUTIONS ARE HIGHLY VARIED. ...NERN STATES... SRN PERIPHERY OF A LEAD H5 SHORTWAVE TROUGH IS EXPECTED TO SKIRT PARTS OF NRN NEW ENGLAND AND NRN NY STATE THU AFTN. THOUGH MOST FORCING FOR LARGE SCALE ASCENT WILL MOVE THROUGH QUE...THERE WILL BE SLIGHT INCREASE IN THE VERTICAL SHEAR ALONG THE BASE OF THIS TROUGH. DIURNALLY-BASED TSTMS THAT FORM ALONG THE MOUNTAINS AND THE PRE-FRONTAL TROUGH MAY BECOME STRONGER DURING PEAK HEATING DUE TO THE INCREASE IN SHEAR. LACK OF A SUSTAINED FOCUS...HOWEVER... WILL LIMIT THE SEVERE THREATS TO ISOLD LARGE HAIL AND DAMAGING WINDS. ...LWR GRTLKS REGION WWD THROUGH THE OZARKS... RATHER WEAK FLOW REGIME AND WARM TROPOSPHERIC TEMPERATURES SHOULD PRECLUDE WIDESPREAD AND ORGANIZED SEVERE WEATHER ACROSS THIS REGION ON THU. THERE WILL LIKELY CONTINUE TO BE A BROAD LOW-LEVEL CONFLUENCE ZONE ALONG NWRN PERIPHERY OF THE BERMUDA HIGH FROM THE OZARKS NEWD INTO THE LWR GRTLKS REGION. MOREOVER...THERE WILL PROBABLY BE NUMEROUS OUTFLOW BOUNDARIES LOCATED FROM PARTS OF MO NEWD INTO SERN LWR MI AT THE START OF THE PERIOD. THESE BOUNDARIES AND THE BROAD CONFLUENCE WILL LIKELY BE THE FOCUS FOR TSTMS THU AFTN. DEPENDING ON THE TRACK OF THE TROPICAL WAVE...MORE TROPICAL AIR MASS WILL ADVECT NWD INTO PARTS OF THE OZARKS. SLIGHTLY STRONGER LLJ ASSOCIATED WITH THIS SYSTEM MAY BE FAVORABLE FOR ISOLD DAMAGING WIND GUSTS WITH A FEW STORMS. OTHERWISE...FARTHER N AND NE...STEEP LAPSE RATE ENVIRONMENT WILL BE FAVORABLE FOR ISOLD DAMAGING WIND GUSTS AND PERHAPS SMALL HAIL. AT THIS POINT... NARROWING IN ON ANY ENHANCED SEVERE SCENARIO IS NOT POSSIBLE AND LOW SEVERE PROBABILITIES WILL SUFFICE. ...SWRN DESERTS... THERE IS APT TO BE SEVERAL ROUNDS OF TSTMS ACROSS THE SWRN DESERTS DURING WED AND WED NIGHT AND COULD EXHAUST STRONGER INSTABILITY/ LAPSE RATES ACROSS THE SWRN DESERTS FOR THU/THU NIGHT. BUT...THESE DETAILS ARE DIFFICULT TO FORECAST THIS FAR IN ADVANCE. UPSHOT IS THAT BOUNDARY LAYER MOISTURE WILL REMAIN QUITE HIGH AND THERE SHOULD BE SLIGHT COOLING ALOFT OWING TO SLIGHTLY MORE NLY MID-LEVEL FLOW REGIME ON ERN EDGE OF THE UPPER ANTICYCLONE. LOW PROBABILITY SEVERE TSTM RISKS WILL BE MAINTAINED. ..RACY.. 07/26/2006  From swody2 at goshenarc.org Wed Jul 26 16:32:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 26 Jul 2006 12:32:51 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261629 SWODY2 SPC AC 261628 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT WED JUL 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WEAK NEAR-TROPICAL SYSTEM NOW OVER SERN TX IS EXPECTED TO LIFT SLOWLY NNEWD DURING THE NEXT COUPLE OF DAYS INTO THE MID SOUTH AS IT BECOMES ENTRAINED IN WEAK NRN STREAM. IN ADDITION...A SERIES OF IMPULSES WILL PROGRESS EWD ACROSS THE MID WEST AND THE NORTHEAST...WITH UPPER RIDGE HOLDING OVER THE NRN/CENTRAL ROCKIES AND ADJACENT HIGH PLAINS. AIR MASS WILL REMAIN QUITE MOIST FROM THE SRN PLAINS INTO THE NORTHEAST...AND ACROSS THE SWRN DESERTS...WHERE SURFACE DEW POINTS IN THE MID/UPPER 60S AND LOWER 70S WILL BE COMMON. ...LOWER MS RIVER VALLEY/MID SOUTH INTO THE SRN GREAT LAKES... COMBINATION OF A VERY MOIST BOUNDARY LAYER AND MODEST TO STRONG HEATING WILL AGAIN SUPPORT A VERY UNSTABLE AIR MASS OVER MUCH OF THIS REGION THURSDAY. OUTFLOW BOUNDARIES AND REMNANTS OF IMPULSE NOW LIFTING INTO SERN TX SHOULD FOCUS SCATTERED THUNDERSTORMS DURING THE FORECAST PERIOD. THOUGH FLOW ALOFT REMAINS QUITE MODEST...DEGREE OF INSTABILITY/LOW LEVEL MOISTURE SHOULD FOCUS A FEW STRONG TO SEVERE THUNDERSTORMS DURING THE AFTERNOON/EVENING WITHIN 15-25 KT EFFECTIVE SHEAR. LOCATION OF ANY INCREASED SEVERE RISK TOO UNCERTAIN ATTM AND WILL MAINTAIN BROAD AREA OF LOW SEVERE PROBABILITIES...THOUGH SLGT RISK MAY BE NEEDED IN LATER OUTLOOKS. ...NORTHEAST... FLOW ALOFT WILL BE A BIT STRONGER ON THURSDAY AS COMPARED TO TODAY AS WELL DEFINED SHORTWAVE TROUGH NOW MOVING ACROSS THE CENTRAL GREAT LAKES LIFTS ENEWD ACROSS QUEBEC. TAIL END OF STRONGER FORCING/ASCENT WILL SKIRT THE REGION AND SHOULD SUPPORT SCATTERED THUNDERSTORMS AS AIR MASS BECOMES MARGINALLY TO MODERATELY UNSTABLE. SURFACE DEWPOINTS IN THE UPPER 60S/LOWER 70S AND EFFECTIVE SHEAR FROM 20-30 KT SHOULD SUPPORT A FEW STRONG TO SEVERE THUNDERSTORMS...MAINLY IN THE FORM OF BRIEFLY-SEVERE WIND GUSTS. HOWEVER...DESPITE THE RICH BOUNDARY LAYER MOISTURE IN PLACE...LAPSE RATES ARE FORECAST TO REMAIN WEAK ATTM AND LIMIT OVERALL SEVERE THREAT. ...SWRN DESERTS... RICH LOW LEVEL MOISTURE WILL AGAIN BE IN PLACE OVER MUCH OF SRN/WRN AZ INTO THE LOWER CO RIVER VALLEY...SUPPORTING MODERATE TO STRONG INSTABILITY. THIS WILL FOCUS SCATTERED TO WIDESPREAD THUNDERSTORMS OVER HIGHER TERRAIN DURING THE AFTERNOON...AND POSSIBLY OVER LOWER ELEVATIONS NEAR RESIDUAL OUTFLOW BOUNDARIES. QUESTIONS REGARDING AVAILABLE LAPSE RATES AND OTHER EFFECTS FROM PRECEDING CONVECTION PRECLUDE ADDING SLGT RISK ATTM. ..EVANS.. 07/26/2006  From swody2 at goshenarc.org Thu Jul 27 05:58:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 27 Jul 2006 01:58:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270555 SWODY2 SPC AC 270553 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1253 AM CDT THU JUL 27 2006 VALID 281200Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF NEW ENGLAND AND THE MID-ATLANTIC REGION... ...SYNOPSIS... MODELS IN GOOD AGREEMENT AT DIGGING AN UPPER TROUGH OFF THE PAC COAST ON FRI WITH A WEAKLY AMPLIFIED TROUGH LIFTING THROUGH NEW ENGLAND AND MID-ATLANTIC REGIONS. THE MAJORITY OF THE COUNTRY WILL CONTINUE BENEATH A LARGE UPPER HIGH THAT WILL BUILD E AND N WITH A CENTER OVER CO BY EARLY SATURDAY. A COUPLE OF SHORTWAVE TROUGHS WILL BE OF INTEREST. AT THE SFC...A SERIES OF WEAK FRONTS THAT HAVE MOVED SWD IN WAKE OF DISTURBANCES PASSING WELL N OF THE GRTLKS THE PAST COUPLE OF DAYS...WILL BE SITUATED FROM THE MID-ATLANTIC REGION WWD INTO THE CORN BELT. A NEW SYNOPTIC COLD FRONT/PRE-FRONTAL TROUGH WILL BEGIN TO MOVE SEWD ACROSS THE DAKS AND INTO PARTS OF THE UPPER GRTLKS AND UPPER MS VLY REGION BY FRI NIGHT. ...NERN STATES SWD TO THE MID ATLANTIC REGION... THERE WILL LIKELY BE A FAIR AMOUNT OF CONVECTIVE CLOUD DEBRIS ACROSS PRIMARILY SRN PARTS OF NEW ENGLAND AND THE MID-ATLANTIC REGION EARLY ON FRI. THERE IS SOME QUESTION ON HOW THIS WILL AFFECT AIR MASS DESTABILIZATION FRI AFTN ALONG/AHEAD OF THE LEE-TROUGH...PARTICULARLY ACROSS SERN PA...MD...DE...NJ AND VA. NONETHELESS...EVEN MODEST HEATING WILL CREATE AN UNSTABLE ENVIRONMENT GIVEN THE RICH BOUNDARY LAYER MOISTURE IN PLACE. TSTMS WILL LIKELY DEVELOP ALONG/AHEAD OF THE PRE-FRONTAL TROUGH/MOUNTAINS FROM PORTIONS OF NEW ENGLAND SWD INTO NERN PA BY EARLY AFTN. OTHER STORMS ARE POSSIBLE FARTHER S...THOUGH COVERAGE WILL BE MODULATED BY INSTABILITY FACTORS. AS THE UPPER TROUGH BEGINS TO ACCELERATE NEWD...WLY MID-LEVEL FLOW AOA 30 KTS IS EXPECTED ATOP THE SSWLY LOW-LEVEL FLOW. ANY TSTM THAT DEVELOPS IN THIS ENVIRONMENT MAY BECOME ORGANIZED AND PRODUCE MAINLY DAMAGING WINDS. MAIN LIMITING FACTORS FOR A ROBUST SEVERE EVENT WILL BE THE MEAGER MID-LEVEL LAPSE RATES. ACTIVITY SHOULD MAINLY BE DIURNALLY DRIVEN AND WEAKEN DURING THE EVE AND/OR AS STORMS MOVE TO THE MARINE LAYER IN SERN NEW ENGLAND/LONG ISLAND. ...SRN PLATEAU/SWRN DESERTS... THE HIGH PRECIPITABLE WATER AIR MASS ACROSS THE SWRN DESERTS IS APT TO BE ADVECTED NWD INTO PARTS OF THE SRN GRT BASIN AHEAD OF THE DIGGING PAC NW TROUGH ON FRI. THIS MAY SUPPORT A NWD EXPANSION OF THE ISOLD SEVERE THREAT INTO PARTS OF SRN UT AND SWRN CO. FARTHER S...WITH THE EXPECTED INCREASE IN TSTMS OVER AZ AHEAD OF THE MID-LEVEL IMPULSE ON DAY 1 /THU/...THERE COULD VERY WELL BE A DOWN DAY ACROSS THE SWRN DESERTS...DESPITE THE ARRIVAL OF AN INVERTED TROUGH MOVING WWD FROM SRN NM/NRN CHIHUAHUA. BUT... THESE DETAILS ARE DIFFICULT TO ANTICIPATE THIS FAR IN ADVANCE. THUS...WILL CONTINUE AT LEAST ISOLD SEVERE PROBABILITIES OVER THE ENTIRE REGION. ...NRN MN/UPPER GRTLKS REGION... LARGE SCALE HEIGHT RISES AND WARMING ALOFT CAN BE EXPECTED OVER THE MAJORITY OF THE PLAINS ON FRI. THIS SHOULD INHIBIT SFC-BASED TSTM CHANCES ALONG THE SEWD MOVING COLD FRONT EXPECTED TO MOVE ACROSS THE ERN DAKS AND MN FRI AFTN/EVE. BUT...DOWNSTREAM...A WEAKER CAP AND A WEAK INFLUENCE OF A DISTURBANCE PASSING JUST N OF THE REGION WILL EXIST ACROSS PORTIONS OF NERN MN...NRN WI AND UPPER MI. A FEW SFC-BASED STORMS WILL BE POSSIBLE LATE FRI AFTN/EVE ACROSS THE REGIONS...LIKELY TRANSITIONING INTO AN ELEVATED STORM CLUSTER FRI NIGHT. INITIAL ACTIVITY WILL HAVE THE RISKS FOR ISOLD LARGE HAIL AND DAMAGING WINDS...WITH THE SEVERE THREATS DIMINISHING OVERNIGHT AND WITH EWD EXTENT. ..RACY.. 07/27/2006  From swody2 at goshenarc.org Fri Jul 28 05:55:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 28 Jul 2006 01:55:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280555 SWODY2 SPC AC 280554 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT FRI JUL 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...SYNOPSIS... BELT OF STRONGER FLOW WILL PERSIST ALONG THE NRN TIER OF THE U.S. THIS PERIOD. SEVERAL IMPULSES WILL MOVE THROUGH THIS BAND OF FLOW. ONE SUCH FEATURE NOW MOVING INTO THE PACIFIC NW IS FORECAST TO BE OVER THE UPPER MS VALLEY EARLY SATURDAY. A STRONGER UPSTREAM SHORTWAVE TROUGH IS FORECAST TO AMPLIFY INTO THE PACIFIC NW THEN EJECT NEWD THROUGH THE NRN ROCKIES AND INTO SWRN CANADA DURING THE DAY. A BAROCLINIC ZONE WILL EXTEND FROM A SURFACE LOW OVER THE DAKOTAS EWD INTO THE GREAT LAKES AREA. A COLD FRONT WILL APPROACH THE NERN STATES SATURDAY NIGHT. ...UPPER MS VALLEY THROUGH GREAT LAKES AREA... THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE FRIDAY NIGHT AND PERSIST INTO EARLY SATURDAY OVER THE NRN PLAINS OR UPPER MS VALLEY AREA WITHIN ZONE OF WARM ADVECTION AND ISENTROPIC ASCENT N OF SURFACE FRONT. THE ATMOSPHERE IN VICINITY OF THE E-W BOUNDARY AND OUTSIDE OF ONGOING CONVECTION IS EXPECTED TO BECOME MODERATELY UNSTABLE. LOW LEVEL DEWPOINTS IN THE 60S...STEEP MID LEVEL LAPSE RATES AND SURFACE HEATING SHOULD CONTRIBUTE TO MLCAPE AROUND 2000 J/KG. AS THE CAP WEAKENS AND THE ATMOSPHERE DESTABILIZES...IT IS POSSIBLE THAT ONGOING ELEVATED STORMS MAY EVENTUALLY BECOME FORWARD PROPAGATING IF THEY CAN ROOT IN THE BOUNDARY LAYER. OTHER SURFACE BASED STORMS MAY DEVELOP ALONG RESIDUAL OUTFLOW BOUNDARIES...ALONG LAKE BREEZE BOUNDARIES OR IN VICINITY OF THE SURFACE FRONT. LARGE SCALE ASCENT ASSOCIATED WITH EWD ADVANCING MID LEVEL IMPULSE MAY ENHANCE THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER THE GREAT LAKES AREA. BELT OF 35 TO 40 KT MID LEVEL FLOW ABOVE SELY LOW LEVEL FLOW NEAR SURFACE FRONT WILL CONTRIBUTE TO SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORMS INCLUDING SUPERCELLS AND BOW ECHOES. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. OTHER MORE ELEVATED STORMS MAY DEVELOP OVERNIGHT ACROSS THE UPPER MS VALLEY WITH DEVELOPING WARM ADVECTION REGIME. LARGE HAIL SHOULD BE THE MAIN THREAT WITH THAT ACTIVITY. ...NERN U.S... A COLD FRONT WILL MOVE INTO THE NERN STATES SATURDAY EVENING AND OVERNIGHT. THE PRE-FRONTAL WARM SECTOR SHOULD BECOME MODERATELY UNSTABLE DURING THE DAY. THUNDERSTORMS THAT DEVELOP UPSTREAM ACROSS CANADA AND ALONG LAKE BREEZES WITHIN THE PRE-FRONTAL WARM SECTOR MAY SPREAD INTO PARTS OF NY AND NEW ENGLAND DURING THE AFTERNOON. LOW LEVEL FLOW IS EXPECTED TO REMAIN WEAK...BUT WNWLY FLOW INCREASING TO 40-50 KT ABOVE 6 KM MAY RESULT IN SUFFICIENT UNIDIRECTIONAL SHEAR FOR MID LEVEL UPDRAFT ROTATION. ISOLATED STRONG WIND GUSTS AND HAIL COULD ACCOMPANY THE STRONGER STORMS. ...CNTRL AND NRN MT... SHORTWAVE TROUGH WILL EJECT NEWD THROUGH THE NRN ROCKIES AND INTO SWRN CANADA DURING THE DAY. LARGE SCALE ASCENT AND OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE A FEW HIGH BASED STORMS OVER WRN MT. THIS ACTIVITY MAY SUBSEQUENTLY SPREAD NEWD THROUGH PARTS OF NRN AND CNTRL MT. AT THIS TIME IT APPEARS THAT COVERAGE WILL BE TOO ISOLATED AND MOISTURE/INSTABILITY TOO MARGINAL FOR A SLIGHT RISK. ...SWRN U.S.... STORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF NM AND AZ AND SUBSEQUENTLY SPREAD SWWD DURING THE DAY. ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ..DIAL.. 07/28/2006  From swody2 at goshenarc.org Fri Jul 28 17:43:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 28 Jul 2006 13:43:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281743 SWODY2 SPC AC 281741 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1241 PM CDT FRI JUL 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...UPPER MS VALLEY THROUGH GREAT LAKES AREA... ACTIVE SEVERE WEATHER DAY APPEARS LIKELY ON SATURDAY FROM THE UPPER MS VALLEY INTO THE CENTRAL GREAT LAKES REGION WITH SEVERAL ROUNDS OF SEVERE STORMS MOVING ESEWD ACROSS THIS REGION. ONE POTENTIALLY SEVERE MCS IS EXPECTED TO BE ONGOING AT 12Z SATURDAY ACROSS PARTS OF ERN ND INTO CENTRAL/NRN MN AS DISCUSSED IN THE SPC DAY 1 CONVECTIVE OUTLOOK...WITH AN ATTENDANT THREAT OF HAIL AND DAMAGING WINDS. THIS MCS WILL BE ASSOCIATED WITH ASCENT AHEAD OF A MID LEVEL SHORT WAVE TROUGH PROGGED TO TRACK ESEWD FROM NWRN MN INTO THE CENTRAL GREAT LAKES BY 30/00Z...AND REACHING NEW ENGLAND BY 12Z SUNDAY. A SURFACE BOUNDARY IS EXPECTED TO REMAIN STATIONARY FROM NRN MI WNWWD THROUGH NRN WI AND CENTRAL MN TO ALONG THE ND/SD BORDER AND WILL BE THE FOCUS FOR STORMS TO TRACK ESEWD THROUGH THESE AREAS DURING DAY 2 PERIOD. AIR MASS ALONG/S OF THIS BOUNDARY IS EXPECTED TO REMAIN VERY MOIST WITH SURFACE DEWPOINTS IN THE UPPER 60S TO AROUND 70. THIS COMBINED WITH SURFACE HEATING BENEATH ERN EXTENT OF ELEVATED MIXED LAYER WILL RESULT IN AN AMPLE INFLOW...PER 30-35 KT WSWLY LLJ...OF MODERATE INSTABILITY TO ONGOING MCS AS IT TRACKS INTO NRN WI/WRN U.P. OF MI SATURDAY MORNING. NAM POINT FORECAST SOUNDINGS SUGGEST THE LIKELIHOOD FOR THIS MCS TO BECOME SURFACE BASED AS SURFACE HEATING COMMENCES SATURDAY MORNING...WITH INCREASING POTENTIAL FOR DAMAGING WINDS. THIS INITIAL MCS SHOULD REACH PARTS OF NRN LOWER MI SATURDAY AFTERNOON WITH THE CONTINUED THREAT FOR DAMAGING WINDS AND HAIL. GIVEN THE ENHANCED LOW LEVEL SHEAR ALONG SURFACE BOUNDARY PER WSWLY LOW LEVEL WINDS BENEATH 50-60 KT WNWLY MID LEVEL AND HIGH SURFACE DEWPOINTS...THREAT FOR TORNADOES WILL EXIST AS WELL. MODELS SUGGEST A SECOND MCS SHOULD DEVELOP ACROSS PARTS OF NERN MN/NWRN WI AREA BY LATE SATURDAY AFTERNOON/EARLY EVENING AS A SWLY LLJ STRENGTHENS ACROSS THE UPPER MS VALLEY. SUFFICIENT ELEVATED INSTABILITY AND EFFECTIVE BULK SHEAR VALUES INDICATED THIS MCS MAY BE SEVERE AS IT TRACKS ESEWD SATURDAY NIGHT THROUGH THE UPPER GREAT LAKES. ...LOWER GREAT LAKES TO NWRN ME... A COLD FRONT WILL MOVE INTO THE NERN STATES SATURDAY EVENING AND OVERNIGHT. THE PRE-FRONTAL WARM SECTOR SHOULD BECOME MODERATELY UNSTABLE DURING THE DAY. THUNDERSTORMS THAT DEVELOP UPSTREAM ACROSS CANADA AND ALONG LAKE BREEZES WITHIN THE PRE-FRONTAL WARM SECTOR MAY SPREAD INTO PARTS OF NY AND NEW ENGLAND DURING THE AFTERNOON. WEAK LAPSE RATES SUGGEST SEVERE THREAT SHOULD BE MARGINAL. HOWEVER...A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE GIVEN EFFECTIVE BULK SHEAR VALUES OF 25-30 KT RESULTING IN ISOLATED STRONG WIND GUSTS AND HAIL IN THE STRONGER CORES. ...NRN HIGH PLAINS... SHORTWAVE TROUGH WILL TRACK NEWD THROUGH THE NRN ROCKIES AND INTO CANADA DURING THE DAY. LARGE SCALE ASCENT AND OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE A FEW HIGH BASED STORMS OVER WRN MT. THIS ACTIVITY MAY SUBSEQUENTLY SPREAD NEWD THROUGH PARTS OF NRN AND CNTRL MT. ADDITIONAL STORMS MAY DEVELOP ALONG FRONT EXTENDING FROM SERN TO NORTH CENTRAL MT. AT THIS TIME IT APPEARS THAT COVERAGE WILL BE TOO ISOLATED AND MOISTURE/INSTABILITY TOO MARGINAL FOR A SLIGHT RISK ACROSS CENTRAL MT. ALTHOUGH INSTABILITY MAY BE GREATER ACROSS ERN MT INTO ND SATURDAY AFTERNOON/NIGHT...MODEL UNCERTAINTIES IN THE EVOLUTION OF THIS ACTIVITY PRECLUDES A SLIGHT RISK. ...SOUTHWESTERN STATES... AN INVERTED SHORT WAVE TROUGH IS EXPECTED TO WEAKEN AS IT SPREADS WWD ACROSS AZ ON SATURDAY...WHILE A MID LEVEL IMPULSE APPROACHES SWRN NM/SERN AZ SATURDAY AFTERNOON/NIGHT. AIR MASS IN THE LOWER ELEVATIONS/DESERTS OF SRN/WRN AZ IS NOT EXPECTED TO BECOME AS UNSTABLE AS EXPECTED DURING DAY 1. NONETHELESS...THUNDERSTORMS SHOULD DEVELOP OVER THE HIGHER TERRAIN OF NM AND AZ AND SUBSEQUENTLY SPREAD SWWD. ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS. ...PARTS OF THE CAROLINAS/SRN VA... AIR MASS ACROSS THIS REGION IS EXPECTED TO BECOME MODERATELY UNSTABLE SUPPORTING AFTERNOON/EVENING THUNDERSTORMS AS MID LEVEL IMPULSE TRACKS SLOWLY EWD FROM THE SRN APPALACHIANS THROUGH NC/VA ON SATURDAY. GENERALLY WEAK DEEP LAYER SHEAR SHOULD RESULT IN PULSE-TYPE STORMS WITH STEEP LOW LEVEL LAPSE RATES SUPPORTING ISOLATED STRONG WIND GUSTS AND HAIL WITH THE STRONGER STORMS. ..PETERS.. 07/28/2006  From swody2 at goshenarc.org Sat Jul 29 05:35:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 29 Jul 2006 01:35:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290535 SWODY2 SPC AC 290533 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 AM CDT SAT JUL 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES... ...SYNOPSIS... LARGE UPPER RIDGE CENTERED OVER THE CNTRL U.S. WILL DOMINATE MOST OF THE COUNTRY...WITH STRONGER BELT OF WLYS REMAINING OVER THE NRN TIER STATES. A POSITIVELY TILTED SHORTWAVE TROUGH WILL AMPLIFY INTO THE PACIFIC NW THEN EJECT NEWD INTO SWRN CANADA. A BROAD...LOW AMPLITUDE UPPER TROUGH WILL PERSIST ACROSS SERN CANADA INTO THE NERN STATES. POTENTIAL ALSO WILL EXIST FOR A SERIES OF SMALLER SCALE VORTICITY MAXIMA TO MOVE THROUGH THE BELT OF STRONGER FLOW. A COLD FRONT WILL MOVE INTO THE NERN STATES...BUT SHOULD STALL DURING THE DAY. THIS BOUNDARY WILL EXTEND NWWD THROUGH THE GREAT LAKES AREA AND TO A SURFACE LOW ACROSS ND. THE WRN PORTION OF THIS BOUNDARY WILL LIFT NWD AS A WARM FRONT. A COLD FRONT WILL ALSO MOVE THROUGH ERN MT INTO ND. ...NERN ND THROUGH NRN MN AND GREAT LAKES AREA... STRONGER BELT OF WLYS WILL MAINTAIN LAPSE RATE PLUME AS FAR EAST AS THE GREAT LAKES. RICH LOW LEVEL MOISTURE WILL PERSIST ALONG AND S OF THE FRONT WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. THESE FACTORS WILL CONTRIBUTE TO POTENTIAL FOR STRONG INSTABILITY WHERE SURFACE HEATING DEVELOPS. PRIMARY UNCERTAINTIES ARE TIMING OF INDIVIDUAL VORT MAXES AND EVOLUTION OF ONGOING CONVECTION. MODELS SUGGEST THAT STORMS MAY BE ONGOING WITHIN ZONE OF WARM ADVECTION FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES AREA EARLY SUNDAY. THIS ACTIVITY WILL SPREAD SEWD AND POTENTIAL WILL EXIST FOR NEW DEVELOPMENT ALONG ASSOCIATED OUTFLOW BOUNDARIES DURING THE AFTERNOON. ON THE LARGER SCALE...HEIGHTS ARE FORECAST TO BUILD FROM THE NRN PLAINS INTO THE UPPER MS VALLEY WITHIN ZONE OF LOW LEVEL WARM AIR ADVECTION. RISING HEIGHTS AND PRESENCE OF EML SUGGEST THUNDERSTORM INITIATION MAY OCCUR FARTHER N THAN PREVIOUS DAYS. NEW INITIATION MAY WAIT UNTIL EVENING AS THE LOW LEVEL JET INCREASES...ENHANCING LIFT N OF BAROCLINIC ZONE FROM NRN MN...EXTREME NRN WI INTO THE UPPER PENINSULA OF MI. VERTICAL SHEAR IN THE 0-6 KM LAYER ON THE ORDER OF 40 KT WILL SUPPORT ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS...ESPECIALLY IF STORMS DEVELOP EARLY ENOUGH TO BE NEAR SURFACE BASED. LARGE HAIL AND DAMAGING WIND WILL BE THE PRIMARY THREATS. ...ERN PORTIONS OF THE OH VALLEY THROUGH NERN U.S.... STORMS MAY DEVELOP IN MORE WEAKLY CAPPED WARM SECTOR FROM OH INTO PA AND WRN NY S OF FRONT EXPECTED TO EXTEND FROM NW-SE ACROSS A PORTION OF NEW YORK. THE ATMOSPHERE IN THIS REGION WILL BECOME MODERATELY UNSTABLE DURING THE AFTERNOON. STRONGEST FLOW IN THE 0-6 KM LAYER WILL REMAIN FARTHER NE ON COOL SIDE OF THE FRONT WITH MODEST DEEP LAYER VERTICAL SHEAR AND MID LEVEL LAPSE RATES IN WARM SECTOR. A FEW MULTICELL STORMS CAPABLE OF PRODUCING ISOLATED STRONG TO DAMAGING WIND GUSTS WILL BE THE MAIN THREAT. ...SWRN U.S.... UPPER LOW OVER THE SWRN STATES IS FORECAST TO MOVE LITTLE THROUGH THIS PERIOD. STORMS WILL LIKELY DEVELOP OVER THE HIGHER TERRAIN AS OROGRAPHIC FORCING AND HEATING INCREASE DURING THE AFTERNOON. THE THERMODYNAMIC ENVIRONMENT WITH MODERATE INSTABILITY AND STEEP LAPSE RATES WILL SUPPORT THE POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS AND HAIL WITH THE STRONGER STORMS. ..DIAL.. 07/29/2006  From swody2 at goshenarc.org Sat Jul 29 17:46:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 29 Jul 2006 13:46:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291746 SWODY2 SPC AC 291745 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 PM CDT SAT JUL 29 2006 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS EXTENDING FROM NRN ND/MN THROUGH GREAT LAKES REGION TO PARTS OF SRN NY/PA/NWRN NJ... ...SYNOPSIS... LONG WAVE TROUGH WILL DEVELOP SWD ALONG THE WEST COAST ON SUNDAY RESULTING IN DOWNSTREAM RIDGE BUILDING EWD...AND EXTENDING FROM THE MS VALLEY INTO ONTARIO/HUDSON BAY BY 12Z MONDAY. STRONGER BELT OF WLYS WILL REMAIN ALONG THE NRN TIER STATES...WITH THE PRIMARY ZONE OF NWLY FLOW ALOFT EXTENDING FROM FAR NRN MN THROUGH THE GREAT LAKES TO MID ATLANTIC/NERN STATES. MODELS ARE IN GENERAL AGREEMENT WITH EJECTING A PACIFIC SHORT WAVE TROUGH NEWD ACROSS THE NRN ROCKIES SUNDAY INTO SRN ALBERTA/SASKATCHEWAN...WHILE A LOW AMPLITUDE TROUGH PERSISTS ACROSS SERN CANADA AND NERN STATES. POTENTIAL ALSO EXISTS FOR SEVERAL SMALLER SCALE VORTICITY MAXIMA TO MOVE THROUGH THE BELT OF STRONGER FLOW. IN THE LOW-LEVELS...A COLD FRONT IS EXPECTED TO STALL FROM SRN NEW ENGLAND INTO SRN NY...WITH THIS BOUNDARY EXTENDING WNWWD THROUGH THE GREAT LAKES REGION TO A SURFACE LOW OVER THE DAKOTAS. THE WRN EXTENT OF THIS BOUNDARY WILL LIFT NWD AS A WARM FRONT ACROSS NRN PLAINS/NRN MS VALLEY. ...NERN ND THROUGH NRN MN AND GREAT LAKES REGION... RICH LOW LEVEL MOISTURE WILL PERSIST ALONG/S OF THE SURFACE FRONT WHILE STRONGER BELT OF WLYS MAINTAINS A PLUME OF STEEP LAPSE RATES INTO THE GREAT LAKES. THESE FACTORS WILL CONTRIBUTE TO MODERATE TO STRONG INSTABILITY FOR THUNDERSTORM DEVELOPMENT ALONG THE SURFACE BOUNDARY AND/OR CONVECTIVE OUTFLOW BOUNDARIES FROM DAY 1 ACTIVITY AS WEAK IMPULSES TRAVERSE THIS REGION. THE FOLLOWING IS A LIKELY SCENARIO FOR DAY 2 SEVERE. AN MCS... POTENTIALLY SEVERE...SHOULD BE ONGOING AT 12Z SUNDAY ACROSS PARTS OF THE NRN MS VALLEY/WRN GREAT LAKES REGION PER SPC DAY 1 CONVECTIVE OUTLOOK. THIS ACTIVITY MAY WEAKEN IN THE MORNING WITH THUNDERSTORM REDEVELOPMENT DOWNSTREAM ACROSS THE GREAT LAKES SUNDAY AFTERNOON INTO THE EVENING. DEEP LAYER SHEAR WILL BE SUFFICIENT FOR SEVERE STORM ORGANIZATION. SEVERE THREAT SHOULD THEN SHIFT FARTHER NWWD AS THE SURFACE FRONT MOVES NWD AND THE RIDGE BUILDS INTO THIS REGION. STRENGTHENING SSWLY PLAINS LLJ SHOULD FOCUS STRONGEST CONVERGENCE ALONG THE U.S./CANADIAN BORDER FROM NRN ND/MN INTO THE UPPER GREAT LAKES REGION WITH POTENTIAL FOR AN OVERNIGHT MCS OVER THIS REGION. ...LOWER GREAT LAKES TO MID ATLANTIC/SWRN NEW ENGLAND REGION... AIR MASS IS ALSO EXPECTED TO BECOME MODERATELY UNSTABLE ALONG/S OF SURFACE BOUNDARY...ESPECIALLY IN AREAS OF STRONGEST SURFACE HEATING. MODELS DIFFER IN THE STRENGTH OF THE NWLY MID LEVEL FLOW/DEEP LAYER SHEAR EXPECTED ACROSS THIS REGION ON DAY 2. NONETHELESS...EVEN THE WEAKER GFS SUGGESTS DEEP LAYER SHEAR WILL BE SUFFICIENT FOR MULTICELLS /SFC-6 KM SHEAR 20-30 KT/. ALTHOUGH MID LEVEL LAPSE RATES WILL BE WEAK...MODERATE INSTABILITY AND THE EXPECTED SHEAR SHOULD BE ADEQUATE FOR AT LEAST A FEW SEVERE STORMS WITH DAMAGING WINDS/HAIL THE PRIMARY THREATS. THUS...HAVE EXTENDED SLIGHT RISK SEWD INTO THE LOWER GREAT LAKES AND PARTS OF THE MID ATLANTIC REGION. ...CENTRAL/ERN MT TO WRN ND... ASCENT AHEAD OF EJECTING PACIFIC SHORT WAVE THROUGH MAY PROMOTE THUNDERSTORM DEVELOPMENT ACROSS THE HIGHER TERRAIN OF THE NRN ROCKIES SUNDAY AFTERNOON...WITH ACTIVITY DEVELOPING NEWD INTO CENTRAL/ERN MT AND WRN ND. WEAK INSTABILITY IN THE VICINITY OF THE INITIAL STORMS SHOULD PRECLUDE A SEVERE THREAT ACROSS WRN MT...BUT GREATER INSTABILITY FARTHER EAST SUGGESTS A FEW STORMS MAY BECOME SEVERE BY SUNDAY EVENING. ...SWRN STATES... ASCENT IN VICINITY OF WEAK UPPER CIRCULATION EXPECTED ACROSS ERN AZ/WRN NM AND WITHIN MOIST AIR MASS SHOULD PROMOTE THUNDERSTORM DEVELOPMENT ACROSS THE SWRN STATES ON DAY 2. MARGINAL TO MODERATE INSTABILITY AND GENERALLY WEAK DEEP LAYER SHEAR SUGGESTS STORM MODE SHOULD BE PULSE WITH ISOLATED STRONG WIND GUSTS THE GREATEST THREAT. ..PETERS.. 07/29/2006  From swody2 at goshenarc.org Mon Jul 31 05:45:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 31 Jul 2006 01:45:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 310546 SWODY2 SPC AC 310544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON JUL 31 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE CNTRL AND NRN PAINS INTO THE UPPER MS VALLEY AND GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF NEW ENGLAND... ...SYNOPSIS... THE COLD FRONT CURRENTLY FROM CNTRL CANADA SWWD INTO THE NRN ROCKIES WILL MOVE SEWD INTO THE GREAT LAKES AND CNTRL PLAINS THIS PERIOD. BY EARLY TUESDAY THIS BOUNDARY IS FORECAST TO EXTEND FROM EXTREME NRN WI SWWD THROUGH NEB INTO SERN WY. THE FRONT MAY BECOME STATIONARY OR LIFT SLIGHTLY NWD OVER THE PLAINS AS A WEAK LEE CYCLONE DEVELOPS IN RESPONSE TO AN APPROACHING UPPER TROUGH. FARTHER EAST A WARM FRONT WILL LIFT NEWD THROUGH NEW ENGLAND AS A SURFACE LOW AND ATTENDANT MID LEVEL JET ADVANCE EWD THROUGH SERN CANADA. THIS REGION WILL REMAIN UNDER THE INFLUENCE OF A BELT OF MODERATE WNWLY MID LEVEL FLOW. ...GREAT LAKES AND UPPER MS VALLEY THROUGH CNTRL/NRN PLAINS AREA... COLD FRONT FORECAST TO STRETCH FROM THE GREAT LAKES SWWD INTO PARTS OF NEB WILL PROVIDE A FOCUS FOR THUNDERSTORMS TUESDAY. AN AXIS OF LOW LEVEL DEWPOINTS IN THE 60S WILL PERSIST IN VICINITY OF THE FRONT...AND SWLY FLOW IN ADVANCE OF THE UPPER TROUGH WILL MAINTAIN AN ELEVATED MIXED LAYER PLUME OVER THIS REGION. MODERATE INSTABILITY IS EXPECTED AS THE BOUNDARY LAYER WARMS DURING THE AFTERNOON. THE HEIGHT GRADIENT WILL INCREASE OVER THE CNTRL PLAINS AS THE UPPER TROUGH ADVANCES INTO THE CNTRL/NRN ROCKIES. POTENTIAL WILL EXIST FOR WEAKER IMPULSES TO EJECT NEWD THROUGH THE CNTRL PLAINS AHEAD OF APPROACHING UPPER TROUGH AS THE MID LEVEL FLOW INCREASES. STORMS SHOULD REDEVELOP DURING THE DAY...ESPECIALLY ALONG AND JUST N OF THE FRONT FROM PARTS OF NEB NEWD INTO THE GREAT LAKES. STRONGEST VERTICAL SHEAR WILL REMAIN IN POST FRONTAL REGION WHERE ENELY LOW LEVEL FLOW WILL EXIST ABOVE 30 KT MID LEVEL FLOW...RESULTING IN 35 TO 40 KT DEEP LAYER SHEAR. THIS SUGGESTS SOME SUPERCELL STRUCTURES WILL BE POSSIBLE WITH ANY SURFACE BASED STORMS ALONG THE FRONT. OTHERWISE...MULTICELL CLUSTERS SHOULD BE THE DOMINANT STORM TYPE. DAMAGING WIND AND HAIL WILL BE THE MAIN THREATS. THUNDERSTORM COVERAGE WILL LIKELY INCREASE OVER THE UPPER MS VALLEY AND STORMS MAY EVOLVE INTO AN MCS DURING THE EVENING AS THE LOW LEVEL JET INCREASES AND ENHANCES LIFT N OF THE FRONT. ...NERN U.S.... MODERATELY UNSTABLE WARM SECTOR WILL SPREAD THROUGH NEW ENGLAND IN WAKE OF WARM FRONT THAT WILL MOVE EWD IN RESPONSE TO EWD ADVANCING SURFACE LOW OVER SERN CANADA. A STRONG MID LEVEL JET MOVING INTO SERN CANADA WILL KEEP THE UPPER RIDGE SUPPRESSED...RESULTING IN MODERATE 35 TO 40 KT MID LEVEL FLOW. WLY LOW LEVEL FLOW WILL ALSO INCREASE OVER NEW ENGLAND AS SURFACE LOW AND MID LEVEL JET ADVANCE EWD THROUGH SERN CANADA. THIS WILL RESULT IN MODERATELY STRONG WLY DEEP LAYER WIND PROFILES. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP IN THE WARM ADVECTION REGIME ALONG RETREATING WARM FRONT. OTHER STORMS MAY DEVELOP OVER CANADA AND SPREAD SEWD THROUGH NEW ENGLAND DURING THE DAY. DAMAGING WIND WILL BE THE PRIMARY THREAT WITH THE STRONGER STORMS. WARM MID LEVEL TEMPERATURES WITH -4C AT 500 MB WILL LIMIT OVERALL LARGE HAIL THREAT. ..DIAL.. 07/31/2006  From swody2 at goshenarc.org Mon Jul 31 17:00:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 31 Jul 2006 13:00:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 311700 SWODY2 SPC AC 311659 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT MON JUL 31 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NORTHERN NY AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO THE GREAT LAKES REGION... LARGE UPPER RIDGE WILL DOMINATE THE WEATHER OVER THE SOUTH-CENTRAL AND SOUTHEAST UNITED STATES ON TUESDAY...WITH BAND OF MODERATELY STRONG WESTERLY MID LEVEL WINDS STRETCHING FROM THE NORTHERN ROCKIES INTO NEW ENGLAND. SEVERAL EMBEDDED FEATURES IN THIS FLOW WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS FROM THE DAKOTAS...ACROSS THE GREAT LAKES REGION...INTO PARTS OF NY/NEW ENGLAND. ...NY/NEW ENGLAND... WATER VAPOR IMAGERY SHOWS SERIES OF IMPULSES TRACKING ACROSS ONTARIO/QUEBEC. THIS SCENARIO WILL CONTINUE TOMORROW WITH NAM/GFS DIFFERING ON TIMING AND PLACEMENT OF INDIVIDUAL SYSTEMS. RATHER STRONG DEEP LAYER WESTERLY FLOW IS EXPECTED TO DEVELOP BY TUESDAY AFTERNOON ACROSS NY AND NORTHERN NEW ENGLAND. THIS WILL HELP TO TRANSPORT STEEP LAPSE RATES EASTWARD...WITH 850MB TEMPERATURES OVER 20C ACROSS MUCH OF THE AREA. VERY MOIST BOUNDARY LAYER DEWPOINTS IN THE UPPER 60S/LOWER 70S WILL CONTRIBUTE TO MLCAPE VALUES OVER 3000 J/KG. PRESENT INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL MOVE FROM SOUTHERN QUEBEC INTO NORTHERN NY/VT/NH TUESDAY AFTERNOON. THIS ACTIVITY SHOULD TRACK EASTWARD ACROSS MUCH OF ME DURING THE AFTERNOON/EVENING. TIMING IS IN QUESTION. HOWEVER...VERY FAVORABLE THERMODYNAMIC AND KINEMATIC PARAMETERS ARE IN PLACE FOR A LONG LIVED MCS PRODUCING DAMAGING WINDS IF MESOSCALE DETAILS FALL INTO PLACE. ...CENTRAL PLAINS INTO GREAT LAKES... SURFACE COLD FRONT IS FORECAST TO EXTEND FROM SOUTHWEST NEB INTO WI TUESDAY AFTERNOON. FULL SUNSHINE AND HOT TEMPERATURES WILL LEAD TO A DEEP MIXED BOUNDARY LAYER ACROSS PARTS OF KS/NEB/IA...LIKELY RESULTING IN SCATTERED HIGH-BASED THUNDERSTORMS. INCREASING LOW/MID LEVEL WIND FIELDS AND MODERATE INSTABILITY WILL ENHANCE THE THREAT OF ISOLATED DAMAGING WINDS ACROSS THIS REGION. FARTHER NORTHEAST OVER MN/WI...CONVERGENCE ALONG THE FRONT WILL ALSO HELP TO ORGANIZE CONVECTION WITH THE THREAT OF HAIL AND DAMAGING WINDS IN STRONGER CELLS. ..HART.. 07/31/2006