From swody2 at goshenarc.org Sat Nov 4 05:55:32 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Nov 2006 00:55:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040558 SWODY2 SPC AC 040557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST FRI NOV 03 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN IS FORECAST TO REMAIN QUASI-ZONAL THROUGH MUCH OF SUNDAY. HOWEVER SOME AMPLIFICATION OF THE PATTERN IS EXPECTED LATE THIS PERIOD. MAIN FEATURE OF INTEREST WILL BE A FULL LATITUDE UPPER TROUGH THAT IS FORECAST TO BEGIN AMPLIFYING OVER THE PLAINS SUNDAY NIGHT. A SHORTWAVE TROUGH EMBEDDED WITHIN THE SRN BRANCH OF THIS FEATURE WILL MOVE INTO THE SRN PLAINS. ...SWRN THROUGH W CNTRL TX... MODIFIED CP AIR WITH UPPER 50S TO LOW 60S DEWPOINTS WILL BEGIN ADVECTING NWWD THROUGH TX SUNDAY AS BOUNDARY LAYER FLOW OVER THE WRN GULF BECOMES SELY IN WAKE OF RETREATING SERN U.S. SURFACE RIDGE. SUFFICIENT LOW LEVEL MOISTURE SHOULD ADVECT FAR ENOUGH WWD BENEATH 6.5-7 C/KM MID LEVEL LAPSE RATES EXPECTED ACROSS W TX TO RESULT IN MLCAPE NEAR 1000 J/KG BY LATE AFTERNOON. ELEVATED STORMS WILL LIKELY BE IN PROGRESS EARLY SUNDAY FARTHER N FROM NRN TX INTO OK WITHIN THE LOW LEVEL WARM ADVECTION REGIME. FARTHER S ACROSS PARTS OF WRN AND SWRN TX...SOME HEATING MAY OCCUR DURING THE AFTERNOON. STORMS MAY DEVELOP IN THIS AREA AS THE CAP WEAKENS AND THE ATMOSPHERE DESTABILIZES. INITIAL ACTIVITY COULD INITIATE OVER THE HIGHER TERRAIN OF SWRN TX. FORCING FOR ASCENT ATTENDING SEWD ADVANCING UPPER TROUGH AND INCREASING SLY LOW LEVEL JET SHOULD RESULT IN AN ENVIRONMENT FAVORABLE FOR OTHER STORMS TO DEVELOP OVER W THROUGH W CNTRL TX DURING THE EVENING. THE THERMODYNAMIC ENVIRONMENT AND EFFECTIVE SHEAR ON THE ORDER OF 35 TO 40 KT APPEAR SUFFICIENT FOR SOME UPDRAFTS TO ROTATE. ISOLATED HAIL AND STRONG WIND GUSTS SHOULD BE THE MAIN THREATS. STORMS MAY EVOLVE INTO ONE OR MORE CLUSTERS AS THEY CONTINUE EAST OVERNIGHT. ..DIAL.. 11/04/2006  From swody2 at goshenarc.org Sat Nov 4 16:31:11 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Nov 2006 11:31:11 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041633 SWODY2 SPC AC 041632 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SAT NOV 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SPLIT FLOW REGIME WILL UNDERGO AMPLIFICATION DURING THE DAY TWO PERIOD AS FULL-LATITUDE TROUGH EVOLVES OVER THE CNTRL CONUS. WITHIN THIS LARGER-SCALE PATTERN...SHORT WAVE TROUGH CURRENTLY APPROACHING THE FOUR-CORNERS REGION WILL SEWD INTO THE SRN PLAINS SUNDAY/SUNDAY NIGHT WITH AN ASSOCIATED BELT OF MODEST /40-45 KTS AT 500 MB/ SPREADING ACROSS NRN TX/SRN OK. IN THE LOW-LEVELS...INVERTED TROUGH FROM NRN MEXICO INTO THE SRN HIGH PLAINS WILL GRADUALLY SHIFT EWD THROUGH THE PERIOD. ...TX... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING SUNDAY MORNING FROM PORTIONS OF THE TX PNHDL EWD THROUGH OK/RED RIVER VALLEY INTO THE WRN OZARK PLATEAU WITHIN LOW-LEVEL WAA REGIME ASSOCIATED WITH AMPLIFYING SRN STREAM TROUGH. TO THE S OF THIS AREA...INCREASING SLY/SELY LOW-LEVEL FLOW WILL ALLOW FOR THE NWD/NWWD ADVECTION OF MODIFIED CP AIR MASS BENEATH MODEST MID LEVEL LAPSE RATES /7 C PER KM/ CONTRIBUTING POCKETS OF MODERATE INSTABILITY E OF INVERTED TROUGH WITH MLCAPES INCREASING TO AROUND 1000 J/KG. WHILE SOME THREAT OF DIURNAL STORMS WILL EXIST DURING THE AFTERNOON FROM N TX INTO THE EDWARDS PLATEAU/CONCHO VALLEY...IT APPEARS THE BETTER POTENTIAL WILL BE SUNDAY NIGHT AS LLJ RE-INTENSIFIES OVER THE LOWER RIO GRANDE VALLEY AND EFFECTIVELY ENHANCES CONVERGENCE ALONG LOW-LEVEL BAROCLINIC ZONE. 30-35 KT OF EFFECTIVE BULK SHEAR COUPLED WITH THE MODEST INSTABILITY INDICATES SOME POTENTIAL FOR ORGANIZED/ROTATING STORMS WITH THE MAIN THREATS BEING ISOLATED...SEVERE HAIL AND PERHAPS LOCALLY DAMAGING WINDS. ..MEAD.. 11/04/2006  From swody2 at goshenarc.org Sun Nov 5 05:15:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 05 Nov 2006 00:15:12 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050517 SWODY2 SPC AC 050515 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST SAT NOV 04 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE GFS...NAM AND ECMWF HAVE COME INTO BETTER AGREEMENT IN HANDLING SRN BRANCH OF FULL LATITUDE UPPER TROUGH THAT WILL CONTINUE THROUGH THE SRN PLAINS AND LOWER MS VALLEY MONDAY. THE GFS HAS BACKED AWAY FROM CLOSING THE SRN BRANCH SHORTWAVE TROUGH OFF OVER THE WRN GULF. ALL MODELS NOW MAINTAIN A PROGRESSIVE OPEN TROUGH. ...SRN AND SERN TX THROUGH THE LOWER MS VALLEY... LITTLE IN THE WAY OF CYCLOGENESIS IS FORECAST AS THE POSITIVELY TILTED SHORTWAVE TROUGH MOVES THROUGH THE SRN PLAINS AND LOWER MS VALLEY. RESULTING MODEST LOW LEVEL WIND FIELDS WILL LIMIT NWD EXTENT AND DEGREE OF MOISTURE RETURN. HOWEVER...DEWPOINTS IN THE MID TO UPPER 60S WILL LIKELY HAVE ADVECTED INTO SRN AND SERN TX BY EARLY MONDAY. RICHER LOW LEVEL MOISTURE MAY ALSO SPREAD INTO SRN LA AS A COASTAL BOUNDARY MOVES INLAND. STORMS WILL LIKELY BE ONGOING EARLY MONDAY WITHIN ZONE OF ASCENT IN ADVANCE OF THE SHORTWAVE TROUGH FROM PARTS OF CNTRL AND ERN TX NEWD INTO THE LOWER MS VALLEY. EARLY ONSET OF CONVECTION OVER MUCH OF WARM SECTOR AND WEAK LAPSE RATES SUGGEST INSTABILITY WILL REMAIN LIMITED. BEST CHANCE FOR DESTABILIZATION WILL BE ACROSS PARTS OF S TX WHERE MORE SURFACE HEATING MAY OCCUR. MODEST MID LEVEL FLOW OF 25 TO 30 KT ACCOMPANYING THE UPPER TROUGH AND LACK OF A STRONG LOW LEVEL JET SUGGEST VERTICAL SHEAR PROFILES WILL REMAIN ONLY MARGINALLY SUFFICIENT FOR ORGANIZED STORMS. SOME POTENTIAL FOR INTENSIFICATION MAY EXIST AS STORMS DEVELOP SEWD DURING THE DAY...MAINLY OVER PARTS OF S TX WHERE MORE INSTABILITY IS EXPECTED. ACTIVITY SHOULD REMAIN MAINLY MULTICELL IN CHARACTER WITH A MARGINAL THREAT OF ISOLATED WIND GUSTS AND SMALL HAIL. ..DIAL.. 11/05/2006  From swody2 at goshenarc.org Sun Nov 5 16:25:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 05 Nov 2006 11:25:56 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051628 SWODY2 SPC AC 051627 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN NOV 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DESPITE SOME DIFFERENCES....LATEST MODEL GUIDANCE SUGGESTS THAT SRN STREAM BRANCH OF FULL LATITUDE TROUGH WILL INTENSIFY AS IT TRANSLATES FROM THE SRN PLAINS EWD INTO THE LOWER MS VALLEY. IN THE LOW-LEVELS...ATTENDANT SURFACE LOW WILL DEVELOP EWD FROM THE TX HILL COUNTY INTO CNTRL MS BY TUESDAY MORNING WITH TRAILING COLD FRONT PUSHING SEWD INTO THE NWRN GULF OF MEXICO. MEANWHILE...WARM FRONT ATTENDANT TO THIS MIGRATORY SURFACE LOW WILL RETREAT NWD THROUGH THE CNTRL GULF COAST. ...TX COAST EWD ACROSS SRN LA/MS... A FAIRLY LARGE SHIELD OF SHOWERS AND TSTMS ARE EXPECTED TO BE ONGOING MONDAY MORNING AHEAD OF AMPLIFYING UPPER WAVE OVER SRN AND ERN PORTIONS OF TX INTO WRN LA WITHIN A RELATIVELY MOIST LOW-LEVEL AIR MASS CHARACTERIZED BY DEWPOINTS IN THE 60S. WEAK LAPSE RATES RESULTING FROM THE WIDESPREAD CLOUDS AND PRECIPITATION WILL LIMIT AIR MASS DESTABILIZATION WITH MLCAPES AOB 500-800 J/KG. ADDITIONALLY...WIND FIELDS ARE NOT FORECAST TO BE PARTICULARLY STRONG WITH GENERALLY 30-40 KT MID-LEVEL FLOW ACROSS SYSTEM WARM SECTOR. HOWEVER...MODEST LOW-LEVEL WAA AND RESULTANT LOW-LEVEL HODOGRAPH CURVATURE INDICATE SOME POTENTIAL FOR EMBEDDED ROTATING STORMS CAPABLE OF LOCALLY STRONG WIND GUSTS AND PERHAPS A BRIEF TORNADO OR TWO. THIS MARGINAL SEVERE STORM THREAT IS FORECAST TO SPREAD FROM THE TX COAST/SWRN LA MONDAY INTO SERN LA AND FAR SRN MS MONDAY NIGHT. ..MEAD.. 11/05/2006  From swody2 at goshenarc.org Mon Nov 6 06:01:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Nov 2006 01:01:49 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060603 SWODY2 SPC AC 060602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 AM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MODELS ARE IN GENERAL AGREEMENT AMPLIFYING A SHORTWAVE TROUGH INTO A CLOSED UPPER LOW OVER THE LOWER MS VALLEY BY EARLY TUESDAY. THIS FEATURE IS FORECAST TO OCCLUDE AND CONTINUE SLOWLY EAST THROUGH THE SERN U.S. DURING THE DAY. ATTENDANT CYCLOGENESIS IS NOT EXPECTED TO BE PARTICULARLY STRONG. BY EARLY TUESDAY AN OCCLUDED FRONT SHOULD EXTEND FROM A WEAK SURFACE LOW OVER THE LOWER MS VALLEY SWWD INTO THE NWRN GULF. A WARM FRONT SHOULD EXIST JUST OFFSHORE OVER THE NERN GULF INTO NRN FL AND MAY LIFT SLOWLY NWD DURING THE DAY. ...CNTRL AND SRN AL...SRN GA THROUGH FL... CONVECTION WILL LIKELY SPREAD NEWD THROUGH THE NERN GULF COASTAL AREA WITHIN WARM ADVECTION ZONE EARLY TUESDAY. ACTIVITY MAY BE MORE WIDESPREAD N OF WARM FRONT FROM PARTS OF THE FL PANHANDLE INTO SERN AL AND SRN GA. BOUNDARY LAYER DEWPOINTS IN THE UPPER 60S TO NEAR 70 SHOULD RESIDE S OF THE WARM FRONT. LOW LEVEL HODOGRAPHS IN VICINITY OF AND JUST N OF THIS BOUNDARY WILL BE FAVORABLE FOR UPDRAFT ROTATION AND LOW LEVEL MESOCYCLONES. HOWEVER...WIDESPREAD CLOUDS AND RAIN WILL LIKELY LIMIT SIGNIFICANT DESTABILIZATION POTENTIAL. BEST CHANCE FOR DESTABILIZATION WILL EXIST S OF THE BOUNDARY WHERE SOME CLOUD BREAKS WILL BE POSSIBLE...BUT WEAKER LOW LEVEL SHEAR PROFILES WILL EXIST IN THIS AREA. OTHER STORMS MAY DEVELOP IN PRE-FRONTAL WARM SECTOR S OF THE WARM FRONT OVER THE NERN GULF AND SPREAD EWD INTO FL BY LATE AFTERNOON AND OVERNIGHT. LARGELY UNIDIRECTIONAL WIND PROFILES WITH SWLY DEEP LAYER SHEAR ON THE ORDER OF 35 TO 40 KT WILL BE SUFFICIENT FOR SOME ORGANIZED STRUCTURES WITHIN THE LINE. FARTHER W NEAR OCCLUDED FRONT ACROSS PARTS OF AL...SOME POTENTIAL FOR DESTABILIZATION WILL EXIST AS UPPER DRY SLOT ADVANCES EWD. HOWEVER...LOW CLOUDS COULD BE SLOW TO MIX OUT AND LIMIT INSTABILITY IN THIS REGION AS WELL WITH MLCAPE GENERALLY AOB 500 J/KG EXPECTED. STILL PROXIMITY TO STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER LOW SUGGEST STORMS COULD INTENSIFY ALONG THE FRONT AND BECOME CAPABLE OF PRODUCING PRIMARILY ISOLATED DAMAGING WIND GUSTS. WILL INTRODUCE 5% SEVERE PROBABILITIES AND NOT UPGRADE TO SLIGHT RISK AT THIS TIME DUE PRIMARILY TO POTENTIAL LIMITING FACTORS UPON THE THERMODYNAMIC ENVIRONMENT. HOWEVER...AN UPGRADE TO SLIGHT RISK MAY BE NEEDED FOR PORTIONS OF THESE AREAS IN LATER OUTLOOKS. ...MS... COLD CORE UPPER LOW WITH -18C AT 500 MB IS FORECAST TO MOVE OVER THE LOWER MS VALLEY DURING THE AFTERNOON. SOME POTENTIAL WILL EXIST FOR STORMS TO DEVELOP IN THIS REGION IN ASSOCIATION WITH VORT MAX. ISOLATED SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...ESPECIALLY IF LOW CLOUDS MIX OUT ALLOWING BOUNDARY LAYER WARMING TO OCCUR. ..DIAL.. 11/06/2006  From swody2 at goshenarc.org Mon Nov 6 17:22:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Nov 2006 12:22:24 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061724 SWODY2 SPC AC 061722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... STRONG HEIGHT FALLS WILL SPREAD EWD ALONG THE CNTRL GULF COAST REGION TUESDAY AS UPPER SPEED MAX TRANSLATES TOWARD THE FL PANHANDLE/SRN AL EARLY IN THE PERIOD. STRONG ASCENT WITHIN A RECOVERING WARM ADVECTION REGIME WILL UNDOUBTEDLY ENHANCE THE CONVECTIVE THREAT AHEAD OF COLD FRONT...AND ATOP COOLER RETREATING BOUNDARY LAYER. RELUCTANCE FOR AIRMASS RECOVERY WILL BE THE MAIN IMPEDIMENT FOR SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE CNTRL/ERN GULF COAST...AND FL PENINSULA AS DEEP LAYER SHEAR WILL PROVE MORE THAN ADEQUATE FOR SUSTAINING DEEP ROTATING UPDRAFTS. AT THIS TIME IT APPEARS WIDESPREAD SHOWERS/THUNDERSTORMS WILL EVOLVE WITHIN WEAK LAPSE RATE/WARM CONVEYOR BELT...A CONTINUATION OF DAY1 ACTIVITY. THIS ACTIVITY SHOULD PROGRESS STEADILY TOWARD THE ATLANTIC COAST WHERE INCREASING LLJ OFFSHORE MAY ALLOW SOMEWHAT MORE BUOYANT AIR TO SPREAD JUST INLAND ALONG THE SC/NC COAST LATE IN THE PERIOD. GIVEN THE EXPECTED CLOUDS/PRECIPITATION...AND LACK OF INSTABILITY...IT APPEARS GREATEST SEVERE POTENTIAL WILL BE LIMITED TO SUPERCELL STRUCTURES NEAR THE COAST/OR MAINLY OFFSHORE...AND THIS ACTIVITY SHOULD PROVE ISOLATED. ...ELSEWHERE... DEEP CONVECTION MAY DEVELOP WITHIN STRONG BAROCLINIC ZONE ACROSS PORTIONS OF THE NRN ROCKIES DURING THE LATTER HALF OF THE PERIOD...MAINLY ACROSS THE HIGHER ELEVATIONS OF ID/WRN MT. ISOLATED THUNDERSTORMS COULD EVOLVE WITHIN THIS FRONTAL BAND AS IT SAGS SEWD TOWARD THE SNAKE RIVER VALLEY. ..DARROW.. 11/06/2006  From swody2 at goshenarc.org Tue Nov 7 05:32:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Nov 2006 00:32:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070534 SWODY2 SPC AC 070532 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST MON NOV 06 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SERN U.S. UPPER LOW WILL CONTINUE EAST AND OFF THE ATLANTIC SEABOARD BY WEDNESDAY NIGHT. BY 12Z WEDNESDAY...ATTENDANT FRONT WILL EXTEND FROM A SURFACE LOW IN EXTREME ERN NC SWWD ALONG THE GULF STREAM AND INTO SRN FL. REMAINING PORTIONS OF FRONT WILL MOVE OFFSHORE DURING MORNING. WIDESPREAD CONVECTION WILL BE ONGOING WITHIN THE ZONE OF ASCENT ALONG AND JUST E OF THIS BOUNDARY. STRONG LOW TO MID LEVEL VERTICAL WIND PROFILES WILL EXIST WITHIN THE PRE-FRONTAL WARM SECTOR. HOWEVER...LIMITED POTENTIAL FOR DESTABILIZATION WILL EXIST BEFORE ACTIVITY MOVES OFFSHORE. OTHER CONVECTION MAY DEVELOP DURING THE DAY FARTHER W NEAR VORT MAX WHERE STEEPER LAPSE RATES AND COLD MID LEVEL TEMPERATURES WILL EXIST. ANOTHER IN A SERIES OF SHORTWAVE TROUGHS WILL MOVE ONTO THE PACIFIC NW ACCOMPANIED BY SCATTERED CONVECTION. STEEP 700-500 MB LAPSE RATES AND COLD MID LEVEL TEMPERATURES ACCOMPANYING THIS FEATURE MIGHT RESULT IN SUFFICIENT INSTABILITY FOR ISOLATED LIGHTING STRIKES...ESPECIALLY NEAR THE COAST. ..DIAL.. 11/07/2006  From swody2 at goshenarc.org Tue Nov 7 17:26:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Nov 2006 12:26:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071728 SWODY2 SPC AC 071727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST TUE NOV 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...MIDDLE ATLANTIC... UPPER LEVEL SPEED MAX WILL SHIFT OFF THE CAROLINA COAST EARLY IN THE PERIOD AS UPPER LOW SETTLES INTO NERN GA. MAIN BAROCLINIC ZONE AND ASSOCIATED CONVECTIVE THREAT SHOULD BE WELL EAST OF THE OUTER BANKS REGION OF NC AT 12Z...TRAILING SWWD INTO THE SRN TIP OF THE FL PENINSULA. HOWEVER...COLD MID LEVEL TEMPERATURES AND A POCKET OF STEEP LAPSE RATES SHOULD ENHANCE THE CONVECTIVE THREAT BENEATH THE UPPER LOW AS IT MOVES ACROSS THE CAROLINAS DURING THE DAY. ADDITIONALLY...THERE APPEARS TO BE AT LEAST A MARGINAL THREAT FOR ISOLATED ELEVATED THUNDERSTORMS WITHIN THE WARM ADVECTION ZONE JUST NORTH OF THE SFC LOW WHERE BOUNDARY LAYER AIRMASS SHOULD PROVE COOL/STABLE. REGARDLESS...ACTIVITY SHOULD PROVE ISOLATED AND WEAK ACROSS THE ENTIRE REGION. ...PACIFIC NW... BUOYANT MARITIME AIRMASS WILL BEGIN SPREADING INLAND AS SFC FRONT PROGRESSES ACROSS WRN WA/ORE EARLY IN THE PERIOD. LOW TOPPED CONVECTION AND ISOLATED THUNDERSTORMS SHOULD BE NOTED WITH UPPER TROUGH AS IT APPROACHES THE COAST. AT THIS TIME IT APPEARS DAYTIME HEATING WILL ENHANCE THE POTENTIAL FOR ISOLATED LIGHTNING WITHIN DEEPER SHOWERS...MAINLY DURING THE AFTERNOON/EVENING HOURS...AND MAINLY CONFINED NEAR THE COAST. ..DARROW.. 11/07/2006  From swody2 at goshenarc.org Wed Nov 8 05:39:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Nov 2006 00:39:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080541 SWODY2 SPC AC 080539 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1139 PM CST TUE NOV 07 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORTWAVE TROUGH OVER THE ERN PACIFIC WILL MOVE INTO THE PLAINS BY LATE THURSDAY. A LEE CYCLONE WILL DEVELOP OVER THE SRN HIGH PLAINS IN ADVANCE OF THIS FEATURE THEN SHIFT NEWD THROUGH OK/KS AND INTO THE MID MS VALLEY OVERNIGHT. AS THE LOW SHIFTS EAST THE DRYLINE WILL SHARPEN ACROSS TX AND OK. COLD FRONT MARKING LEADING EDGE OF CP AIR WILL MOVE SWD THROUGH THE CNTRL PLAINS THURSDAY...THEN ACCELERATE INTO THE SRN PLAINS OVERNIGHT AS THE LOW LIFTS NEWD INTO THE MID MS VALLEY. ...N CNTRL/NERN OK...ERN KS THROUGH SWRN AND CNTRL MO... MODIFIED CP AIR WILL ADVECT NWD THROUGH THE SRN PLAINS AND LOWER MS VALLEY THURSDAY AS SSWLY BOUNDARY LAYER FLOW INCREASES DOWNSTREAM FROM DEVELOPING CYCLONE. HOWEVER SWLY FLOW IN THE 850-700 MB LAYER WILL LIKELY ADVECT AN EML PLUME THROUGH THE SRN PLAINS AND INTO THE LOWER MS VALLEY ABOVE THE MOISTENING BOUNDARY LAYER. THESE PROCESSES WILL CONTRIBUTE TO DESTABILIZATION DURING THE DAY. HOWEVER...THE EML WILL LIKELY CAP THE WARM SECTOR. A FEW STORMS COULD DEVELOP THURSDAY NIGHT FROM PARTS OF NERN OK...ERN KS THROUGH MO WITHIN ZONE OF LIFT ASSOCIATED WITH THE SWD ADVANCING FRONT AND SWLY LOW LEVEL JET. MOST ACTIVITY WILL PROBABLY BE ELEVATED ON COOL SIDE OF FRONT GIVEN THE ANTICIPATED AMOUNT OF LIFT NEEDED TO OVERCOME CAP. LAPSE RATES OF 7-7.5 C/KM IN THE 700-500 MB LAYER SUGGEST THE STRONGER STORMS COULD PRODUCE SMALL HAIL...BUT INSTABILITY WILL PROBABLY BE TOO MARGINAL FOR A MORE ROBUST THREAT. ..DIAL.. 11/08/2006  From swody2 at goshenarc.org Wed Nov 8 17:19:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Nov 2006 12:19:31 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081721 SWODY2 SPC AC 081719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CST WED NOV 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT SHORT WAVE IMPULSES...EMBEDDED WITHIN SPLIT BELTS OF POLAR WESTERLIES...WILL REMAIN PROGRESSIVE ACROSS CANADA AND THE U.S. THROUGH THIS FORECAST PERIOD. IN THE WAKE OF THE CLOSED LOW...PROGGED TO BE LIFTING AWAY FROM THE SOUTH ATLANTIC COAST BY 12Z THURSDAY...THE SOUTHERN AND SUBTROPICAL STREAMS WILL BE OUT OF PHASE THROUGH MUCH OF THE REMAINDER OF THIS PERIOD ...WITH THE WEAK SUBTROPICAL STREAM GENERALLY SOUTH OF THE U.S. BORDER. THE NEXT SIGNIFICANT SHORT WAVE TROUGH DIGGING INTO THE SOUTHERN STREAM IS ALREADY ADVANCING INTO NORTH CENTRAL PACIFIC COASTAL AREAS...AND PROGGED TO CONTINUE INTO THE NORTHERN GREAT BASIN BY 12Z THURSDAY...THEN ACROSS THE NORTH CENTRAL ROCKIES INTO THE NORTHERN/CENTRAL PLAINS BY 12Z FRIDAY. MODELS SUGGEST THIS FEATURE WILL CONTRIBUTE TO WEAK SURFACE CYCLOGENESIS TO THE LEE OF THE SOUTH CENTRAL ROCKIES. THIS WILL OCCUR NEAR/SOUTH OF A COLD FRONT SURGING SOUTHWARD THROUGH THE PLAINS...IN THE WAKE OF A NORTHERN STREAM IMPULSE WHICH IS PROGGED TO SHIFT EAST OF THE UPPER GREAT LAKES REGION ON THURSDAY. ...GREAT BASIN THRU THE CNTRL/SRN PLAINS AND MS VALLEY... COLD AIR ALOFT ASSOCIATED WITH THE SHORT WAVE TROUGH EMANATING FROM THE PACIFIC WILL CONTRIBUTE TO WEAK DESTABILIZATION ACROSS THE EASTERN GREAT BASIN AND NORTH CENTRAL ROCKIES BY THURSDAY AFTERNOON. THIS WILL PROBABLY BE ACCOMPANIED BY WEAK CONVECTIVE DEVELOPMENT...PARTICULARLY ACROSS THE HIGHER TERRAIN...WHERE SOME POTENTIAL WILL EXIST FOR A THUNDERSTORM. HOWEVER...AREAL COVERAGE/PROBABILITY OF OCCURRENCE APPEARS LOW. OTHERWISE...CONVECTIVE POTENTIAL IS EXPECTED TO REMAIN LIMITED THURSDAY/THURSDAY NIGHT ACROSS MUCH OF THE CENTRAL STATES... DESPITE THE LIKELIHOOD OF AT LEAST A WEAK RETURN FLOW OF MOISTURE FROM THE WESTERN GULF OF MEXICO. MOISTURE SUFFICIENT FOR VIGOROUS CONVECTIVE DEVELOPMENT IS ALREADY PRESENT ACROSS WESTERN GULF COASTAL AREAS...AND WILL PROBABLY ADVECT THROUGH MUCH OF THE SOUTHERN PLAINS AND LOWER HALF OF THE MISSISSIPPI VALLEY THURSDAY. HOWEVER...THIS WILL OCCUR BENEATH A RATHER WARM AND DRY MID-LEVEL ENVIRONMENT...WHICH MODEL FORECAST SOUNDINGS SUGGEST WILL SUPPRESS DEEP CONVECTION. AN EXCEPTION TO THIS MAY BE ON THE LEADING EDGE OF THE BETTER MOISTURE RETURN...AS IT ENCOUNTERS A STRENGTHENING LOW/MID-LEVEL FRONTAL ZONE ACROSS PARTS OF NORTHEAST KANSAS/NORTHERN MISSOURI/SOUTHERN IOWA...TOWARD 12Z FRIDAY. ..KERR.. 11/08/2006  From swody2 at goshenarc.org Thu Nov 9 06:07:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Nov 2006 01:07:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090609 SWODY2 SPC AC 090607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1207 AM CST THU NOV 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN TX THROUGH THE LOWER MS VALLEY AND WRN TN VALLEY... ...SYNOPSIS... UPPER TROUGH OVER THE W COAST WILL MOVE EAST INTO THE PLAINS FRIDAY. INCREASING WLY UPPER FLOW AND HEIGHT FALLS DOWNSTREAM FROM THIS FEATURE WILL CONTRIBUTE TO LEE CYCLOGENESIS OVER THE HIGH PLAINS THURSDAY. AS UPPER TROUGH MOVES THROUGH THE PLAINS...THE LOW WILL SHIFT RAPIDLY NEWD THROUGH OK INTO THE MID MS VALLEY REACHING THE OH VALLEY FRIDAY NIGHT. BY 12Z FRIDAY A FRONT WILL EXTEND FROM THE OH VALLEY SWWD THROUGH OK AND NWRN TX. A DRYLINE WILL EXTEND FROM THE LOW IN OK SWD THROUGH CNTRL TX. AS THE LOW LIFTS NE DURING THE DAY...THE FRONT WILL SURGE SE THROUGH THE SRN PLAINS AND MID TO LOWER MS VALLEYS DURING THE DAY...REACHING THE OH AND TN VALLEYS OVERNIGHT. ...ERN TX THROUGH THE LOWER MS VALLEY AND WRN TN VALLEY REGION... SWLY LOW LEVEL JET WILL DEVELOP OVER THE SRN PLAINS E OF SURFACE LOW AND ADVECT PARTIALLY MODIFIED GULF AIR NWD THROUGH THE PRE-FRONTAL WARM SECTOR. LOW LEVEL DEWPOINTS IN THE MID TO UPPER 60S ARE EXPECTED OVER THE SRN PLAINS AND LOWER MS VALLEY WITH LOWER 60S POSSIBLE INTO SRN MO. THE MOIST AXIS WILL SHIFT EAST AS THE LOW LEVEL JET VEERS DURING THE DAY. OBSERVED SOUNDINGS FROM WEDNESDAY EVENING SHOW AN EML HAS ADVECTED INTO W TX. THIS WARM LAYER WILL SPREAD EAST ABOVE MOIST AXIS THROUGH EARLY FRIDAY. WHILE THIS WILL SERVE TO DESTABILIZE THE ATMOSPHERE...MUCH OF THE WARM SECTOR OVER THE SRN PLAINS AND LOWER MS VALLEY WILL LIKELY REMAIN CAPPED TO SURFACE BASED STORMS MUCH OF THE DAY. MUCAPE WILL LIKELY RANGE FROM AROUND 1500 TO 2000 J/KG OVER THE SRN PLAINS AND LOWER MS VALLEY TO BELOW 800 J/KG FARTHER NE ACROSS THE MID MS VALLEY INTO THE OH VALLEY. ELEVATED STORMS WILL LIKELY BE ONGOING OVER PARTS OF NERN KS INTO NRN MO EARLY FRIDAY ALONG NERN EDGE OF THE STRONGER CAP AND WITHIN ZONE OF ASCENT N OF FRONTAL BOUNDARY. STORMS SHOULD CONTINUE EAST THROUGH THE MID MS VALLEY DURING THE DAY WITHIN ZONE OF STRONGEST FORCING FOR ASCENT ASSOCIATED WITH FRONT AND EWD ADVANCING SHORTWAVE TROUGH. FARTHER S OVER ERN TX AND THE LOWER MS VALLEY EXPECT INITIATION TO BE DELAYED UNTIL LATE AFTERNOON WHEN SEWD MOVING FRONT WILL INTERACT WITHIN MOISTENING AND DESTABILIZING BOUNDARY LAYER. GIVEN EXPECTED CAP...STORMS WILL LIKELY REMAIN CONFINED TO FRONTAL ZONE IN THIS REGION. SHEAR PROFILES WILL DECREASE WITH SWD EXTENT INTO THE LOWER MS VALLEY AND TX. HOWEVER...STORMS WILL LIKELY ORGANIZE INTO LINE SEGMENTS WITH ISOLATED DAMAGING WIND AND HAIL THE PRIMARY THREATS. SOME SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE MAINLY ACROSS PARTS OF AR WHERE BEST COMBINATION OF SHEAR AND INSTABILITY IS EXPECTED. ACTIVITY WILL SHIFT EAST INTO THE TN VALLEY OVERNIGHT. FARTHER N FROM SRN MO THROUGH WRN KY...INSTABILITY WILL BE MORE LIMITED BUT VERTICAL WIND PROFILES AND DEEP LAYER FORCING WILL BE STRONGER. PRIMARY THREAT WITH STORMS DEVELOPING ALONG THIS PORTION OF THE FRONT WILL BE ISOLATED DAMAGING WIND GUSTS...BUT POTENTIAL FOR A STABLE BOUNDARY LAYER COULD LIMIT OVERALL THREAT IN THIS REGION. ..DIAL.. 11/09/2006  From swody2 at goshenarc.org Sat Nov 11 05:56:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Nov 2006 00:56:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110558 SWODY2 SPC AC 110557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST FRI NOV 10 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW IS FORECAST OVER THE CAROLINAS AT THE START OF THE PERIOD...AND SHOULD CONTINUE EWD/ENEWD OFF THE MID-ATLANTIC COAST. ASSOCIATED SURFACE LOW -- THOUGH POSSIBLY INLAND AT THE START OF THE PERIOD -- SHOULD ALSO MOVE OFFSHORE THROUGH THE FIRST HALF OF THE PERIOD. SOME THUNDER THREAT MAY LINGER FROM THE COASTAL CAROLINAS NWD INTO SRN NEW ENGLAND INVOF UPPER LOW...BUT ANY SEVERE THREAT APPEARS MINIMAL AT BEST ATTM. MEANWHILE...LARGE/LOW-AMPLITUDE TROUGH IS FORECAST TO EXPAND EWD INTO THE CENTRAL CONUS...WITH MOST OF THE COUNTRY UNDER THE INFLUENCE OF CYCLONIC UPPER FLOW BY THE END OF THE PERIOD. THOUGH A LIGHTNING STRIKE OR TWO MAY OCCUR OVER MT AND VICINITY DURING THE AFTERNOON...THUNDER THREAT SHOULD REMAIN LIMITED AT BEST ACROSS THE WRN HALF OF THE CONUS. ..GOSS.. 11/11/2006  From swody2 at goshenarc.org Sat Nov 11 17:19:57 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Nov 2006 12:19:57 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 111721 SWODY2 SPC AC 111720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CST SAT NOV 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... CLOSED LOW EXPECTED TO DEVELOP OVER VA/CAROLINAS LATE DAY 1 WILL TRACK E OFF THE MID ATLANTIC COAST ON SUNDAY. MODELS DIVERGE WITH THE TRACK OF THIS SYSTEM AS IT MOVES OFFSHORE...WITH GREATER TRACK SPREAD SUGGESTED BEYOND DAY 2. MEANWHILE...BROAD CYCLONIC FLOW PATTERN SHOULD DEVELOP ACROSS MUCH OF THE CONUS BY 12Z MONDAY AS UPPER TROUGH NOW ENTERING WEST COAST SPREADS INLAND AND A SECOND TROUGH APPROACHES THE WEST COAST. SURFACE CYCLOGENESIS EXPECTED OVER VA TIDEWATER REGION LATE DAY 1 WILL ALSO MOVE OFFSHORE THIS FORECAST PERIOD. A BAND OR TWO OF CONVECTION/TSTMS MAY BE ONGOING ACROSS ERN NC AND THE ADJACENT COASTAL WATERS NWD TO VA CAPES IN RESPONSE TO STRONG DEEP LAYER ASCENT WITHIN EXIT REGION OF 100 KT 500 MB JET OVER CAROLINAS. ISOLATED STRONG WIND GUSTS COULD BE POSSIBLE WITH THIS ACTIVITY. HOWEVER...UNFAVORABLE TIME OF DAY...WEAK LOW LEVEL LAPSE RATES...AND LIMITED GEOGRAPHICAL AREA PRECLUDE ADDITION OF SEVERE THREAT AT THIS TIME. ANY ADDITIONAL THREAT FOR STRONG AND/OR SEVERE STORMS SHOULD DEVELOP OFFSHORE AS THE UPPER LOW AND ATTENDANT SURFACE LOW MOVE E OF THE COAST. ..PETERS.. 11/11/2006  From swody2 at goshenarc.org Sun Nov 12 05:22:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Nov 2006 00:22:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120524 SWODY2 SPC AC 120523 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 PM CST SAT NOV 11 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SE TX... THE UPPER WAVE DIGGING INTO THE DESERT SW APPEARS QUITE STRONG AND THE LATEST NAM DEPICTION OF SHEARING THE IMPULSE QUICKLY NEWD INTO THE MIDWEST ON MONDAY MAY BE PREMATURE. SIDING WITH 00Z GFS/12Z ECMWF WITH A SLOWER...STRONGER AND MORE SRN SOLUTION WOULD MAINTAIN ENELY BOUNDARY LAYER FLOW ALONG THE NRN GULF OF MEXICO FOR A LONGER PERIOD OF TIME INTO MON AFTN. IT DOES APPEAR THAT RETURN FLOW WILL BEGIN IN EARNEST MON NIGHT ACROSS PARTS OF ERN TX AS WEAK DISTURBANCES...PRECEEDING A POWERFUL WCOAST UPPER JET...MOVE EWD TO THE PLAINS. A WARM NOSE BETWEEN H8-H7 ACROSS TX WILL LIKELY KEEP SFC BASED CONVECTION FROM DEVELOPING...BUT SUFFICIENT MOISTENING IN THE MID-UPPER LEVELS SHOULD BE FAVORABLE FOR ELEVATED TSTMS ACROSS SERN TX BY 12Z TUE. ATTM...ELEVATED INSTABILITY SHOULD BE MINIMAL ENOUGH TO PRECLUDE SEVERE TSTMS. ...COASTAL PAC NW... STRONG AND MOIST WLY POST-FRONTAL FLOW WILL DEVELOP BENEATH STEEP LAPSE RATES ALONG CYCLONIC SIDE OF A 100+ UPPER JET MON AFTN/EVE. THIS WILL BE SUFFICIENT FOR SCATTERED TSTMS ALONG/W OF THE COASTAL RANGES. ISOLD LIGHTNING /LESS THAN 10% COVERAGE/ MAY ALSO OCCUR WELL INTO MONDAY NIGHT ACROSS THE NRN INTERMOUNTAIN WEST AS THE UPPER DISTURBANCE QUICKLY MOVES EWD. ...SERN NEW ENGLAND... SLOW MOVING NOREASTER WILL BEGIN TO AFFECT NEW ENGLAND MON INTO TUE. CONSIDERABLE AMOUNTS OF MOISTURE WILL BE DRAWN INTO THIS SYSTEM WITH ELEVATED INSTABILITY DEVELOPING MON NIGHT/EARLY TUE WITHIN HEAVIER BANDS OF PCPN TO THE NW OF THE SFC LOW. TSTMS WILL BE POSSIBLE...PRIMARILY LATE MONDAY NIGHT AS THE CYCLONE DEEPENS. ..RACY.. 11/12/2006  From swody2 at goshenarc.org Mon Nov 20 06:21:20 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Nov 2006 01:21:20 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200624 SWODY2 SPC AC 200623 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 AM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH WILL PERSIST OFF THE WRN CANADA/PAC NW COASTS...WHILE RIDGE SHIFTS SLOWLY EWD ACROSS THE SWRN AND INTO THE S CENTRAL CONUS. BETWEEN THESE TWO FEATURES...A BROAD FETCH OF WSWLY FLOW WILL REMAIN IN PLACE ACROSS THE WRN AND N CENTRAL CONUS...WHILE SPREADING EWD ACROSS THE GREAT LAKES REGION. OTHER FEATURE OF INTEREST ALOFT WILL BE A CLOSED LOW WHICH SHOULD DEEPEN WHILE MOVING SLOWLY EWD ACROSS FL THROUGH THE END OF THE PERIOD. ...PAC NW... FAST FETCH OF WSWLY FLOW ALOFT AHEAD OF UPPER TROUGH SHOULD RESULT IN SHOWERS -- AND PERHAPS A FEW LIGHTNING STRIKES -- ACROSS UPSLOPE FAVORED AREAS OF THE NWRN CONUS. ...COASTAL CAROLINAS SWD ALONG THE FL ATLANTIC COAST... COLD MID-LEVEL TEMPERATURES ASSOCIATED WITH UPPER LOW SHOULD CONTRIBUTE TO MINIMAL INSTABILITY -- AND ASSOCIATED POTENTIAL FOR MAINLY OFFSHORE THUNDER. BEST CHANCE FOR ONSHORE LIGHTNING WILL LIKELY EXIST ACROSS THE COASTAL CAROLINAS...WHERE ELY FETCH OF LOW-LEVEL MOISTURE OFF THE GULF STREAM N OF DEVELOPING SURFACE LOW MAY CONTRIBUTE TO WEAK ELEVATED INSTABILITY. ..GOSS.. 11/20/2006  From swody2 at goshenarc.org Mon Nov 20 16:41:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Nov 2006 11:41:27 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201644 SWODY2 SPC AC 201643 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1043 AM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...SRN STREAM SYNOPTIC PATTERN FCST TO REMAIN HIGHLY AMPLIFIED THROUGH PERIOD...FEATURING DEEP ERN MEAN TROUGH...AND POSITIVELY TILTED RIDGE FROM NRN MEX ACROSS UPPER MS VALLEY/UPPER GREAT LAKES REGION. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN MS AND SERN LA -- IS FCST TO PHASE WITH ANOTHER TROUGH NOW OVER ERN KY AND DIG ESEWD. RESULTANT CLOSED CYCLONE SHOULD MOVE SLOWLY EWD ACROSS SRN GA AND FL PENINSULA...AND WILL BE ANOMALOUSLY INTENSE FOR THIS REGION. NRN STREAM PATTERN IS FCST TO DEAMPLIFY OVER CONUS. BROAD BELT OF WSWLY FLOW WILL DEVELOP FROM PACIFIC NW TO ONTARIO...DOWNSTREAM FROM SEWD-MOVING MID/UPPER LEVEL LOW NOW OVER GULF OF AK. SFC CYCLOGENESIS IS FCST JUST OFFSHORE NRN FL/SERN GA...IN RESPONSE TO APCHG/DEEPENING LOW ALOFT. SFC LOW SHOULD DEEPEN ESSENTIALLY IN PLACE...AS UPPER VORTEX APCHS AND BECOMES MORE VERTICALLY CONTINUOUS WITH SFC CYCLONE. THIS WILL REINFORCE POST COLD FRONTAL BAROCLINIC GRADIENT ALREADY IN PLACE ACROSS FL...BUT ALSO WILL STIMULATE LOW LEVEL WARM-FRONTOGENESIS OVER ATLANTIC WATERS OFFSHORE GA AND CAROLINAS. ...SRN ATLANTIC COAST... ALTHOUGH SFC BASED BUOYANCY AND BULK OF TSTMS EACH SHOULD REMAIN OFFSHORE...STRENGTHENING FRONTOGENETIC FORCING AND ELEVATED LOW LEVEL WAA WILL RESULT IN SUFFICIENT LIFT AND DESTABILIZATION TO SUPPORT POTENTIAL FOR TSTMS FROM COASTAL GA/CAROLINAS EWD. ALTHOUGH LOW-MIDLEVEL LAPSE RATES WILL BE WEAK...ELEVATED MUCAPES UP TO ABOUT 200 J/KG MAY REACH INTO FAVORABLE ICING LAYERS FOR LIGHTNING. ...WRN PACIFIC NW... APCHG MID-UPPER LEVEL LOW WILL RESULT IN INTENSIFYING LOW LEVEL WAA REGIME...AS WELL AS FRONTOGENESIS...AS NOTED IN DAY-1 OUTLOOK. POST-FRONTAL AIR MASS DAY-2 WILL BE CHARACTERIZED BY WEAK BUOYANCY BUT ALSO MINIMAL CINH OVER COASTAL/OFFSHORE WATERS OF PACIFIC...WHERE DESTABILIZATION WILL BE GREATEST...SUPPORTING OFFSHORE DEVELOPMENT OF TSTMS. SOME OF THIS ACTIVITY WILL MOVE INLAND BEFORE WEAKENING. ..EDWARDS.. 11/20/2006  From swody2 at goshenarc.org Tue Nov 21 06:40:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Nov 2006 01:40:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210644 SWODY2 SPC AC 210642 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1242 AM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN TO REMAIN RELATIVELY UNCHANGED ON THE LARGE SCALE...WITH UPPER TROUGH OFF THE W COAST OF NOAM MAKING SLOW EWD/ONSHORE PROGRESS...WHILE UPPER LOW DRIFTS SLOWLY NWD FROM JUST OFF THE N FL/GA COAST TO THE COASTAL CAROLINAS BY THE END OF THE PERIOD. THOUGH THUNDER THREAT SHOULD AGAIN REMAIN LIMITED...A FEW ONSHORE STRIKES ARE ONCE AGAIN ANTICIPATED ACROSS PORTIONS OF THE MID-ATLANTIC COAST AND COASTAL CAROLINAS INVOF UPPER LOW. MEANWHILE...SPORADIC STRIKES ARE ALSO ANTICIPATED OVER PORTIONS OF WRN WA/WRN ORE -- PARTICULARLY AS A STRONGER SHORT-WAVE TROUGH MOVES ONSHORE DURING THE SECOND HALF OF THE PERIOD. IN BOTH OF THESE AREAS HOWEVER...VERY LIMITED INSTABILITY SHOULD PRECLUDE ANY APPRECIABLE SEVERE THREAT. ..GOSS.. 11/21/2006  From swody2 at goshenarc.org Tue Nov 21 16:22:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Nov 2006 11:22:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211625 SWODY2 SPC AC 211624 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1024 AM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...COASTAL SECTIONS OF NC/SERN VA/ERN SHORES MD... STRONG UPPER LOW IS EXPECTED TO WOBBLE NWD ALONG THE SERN ATLANTIC COAST TO THE NC OUTER BANKS BY 12Z THU. WARM CONVEYOR WILL WRAP GULF STREAM PARCELS TO NWRN QUADRANT OF THE MATURE LOW RESULTING IN SUFFICIENT ELEVATED INSTABILITY FOR SPORADIC LIGHTNING STRIKES WITHIN STRONGER ONSHORE BANDING STRUCTURES. HIGHER TSTM PROBABILITIES WILL BE CONFINED TO WED NIGHT ALONG THE NC OUTER BANKS NWD TO THE ERN SHORES MD. ...PAC NW... MAIN PORTION OF THE STUBBORN GULF OF AK UPPER LOW WILL DISLODGE AND COME ASHORE THE PAC NW WED AFTN/NIGHT. H5 TEMPERATURES AOB MINUS 30 DEG C ASSOCD WITH THE TROUGH WILL SPREAD ACROSS WA...ORE...NRN CA AND WRN ID DURING THE PROGRESS OF THE DAY. HIGHEST TSTM PROBABILITIES WILL FAVOR THE COASTAL RANGES WHERE THE MOIST UPSLOPE FLOW COMBINES WITH THE STEEPENING MID-TROPOSPHERIC LAPSE RATES AND CYCLONIC FLOW. TSTMS MAY ALSO OCCUR INLAND OVER THE HIGHER TERRAIN OF ERN WA/ORE AND WRN ID WED NIGHT...BUT COVERAGE SHOULD BE ISOLD AND LESS THAN 10 PERCENT. ..RACY.. 11/21/2006 WWWW From swody2 at goshenarc.org Wed Nov 22 06:49:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Nov 2006 01:49:31 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220652 SWODY2 SPC AC 220650 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH IS FORECAST TO EXPAND/DEEPEN WHILE SHIFTING EWD ACROSS THE WRN HALF OF THE CONUS...AS LEAD SHORT-WAVE TROUGH MOVES INTO THE CENTRAL PLAINS LATE. MEANWHILE...UPPER LOW INITIALLY INVOF THE VA/NC COAST IS FORECAST TO MOVE NNEWD AND WEAKEN THROUGH THE END OF THE PERIOD. SOME THUNDER WILL BE POSSIBLE OVER PARTS OF THE PAC NW -- PARTICULARLY THE WRN THIRD OF WA/ORE...AS WELL AS PORTIONS OF THE ATLANTIC COAST FROM SRN NEW ENGLAND TO THE COASTAL NC. HOWEVER...STABLE AIRMASS IS FORECAST TO PERSIST ACROSS THE CENTRAL CONUS AHEAD OF APPROACHING UPPER FEATURE AND ASSOCIATED COLD FRONT...PRECLUDING THE THREAT FOR DEEP MOIST CONVECTION. ..GOSS.. 11/22/2006 WWWW From swody2 at goshenarc.org Wed Nov 22 16:50:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Nov 2006 11:50:08 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221653 SWODY2 SPC AC 221652 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1052 AM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID-UPPER LEVEL PATTERN CHANGE WILL BE UNDERWAY DURING THIS PERIOD AS MEAN ERN TROUGH WEAKENS AND HEIGHTS FALL ACROSS MUCH OF WRN CONUS. AS THIS OCCURS...ANOMALOUSLY DEEP/COLD CYCLONIC VORTEX NOW OFFSHORE SC/GA IS FCST TO CONTINUE FILLING AND TO EJECT NEWD OVER GULF STREAM. ASSOCIATED SFC CYCLONE -- ANALYZED ATTM OVER NC OUTER BANKS -- SHOULD BE JUST OFFSHORE NERN NC AROUND 23/12Z...LIKEWISE LIFTING NEWD OVER ATLANTIC WATERS. MEANWHILE...SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OFFSHORE ORE/NRN CA -- WILL MOVE EWD QUICKLY FROM INTERIOR PACIFIC NW TO NRN PLAINS DAY-2. THIS WILL ENGENDER STRONG SFC CYCLOGENESIS ACROSS NRN HIGH PLAINS...IN LEE OF ROCKIES. RESULTANT SFC LOW SHOULD LIFT NEWD OVER PORTIONS SRN SASK/MB BY 24/12Z. HOWEVER...MOISTURE IN WARM SECTOR OF THIS SYSTEM WILL BE TOO SCANT TO SUPPORT CONVECTIVE POTENTIAL. FARTHER NW...MID-UPPER LEVEL SPEED MAX NOW DIGGING SWD FROM SRN GULF OF AK SHOULD PIVOT EWD...WITH ASSOCIATED TROUGH MOVING ASHORE WA/ORE BETWEEN 24/00-24/06Z. ...PACIFIC NW... DEEP-LAYER AIR MASS SHOULD BE SLIGHTLY MORE STABLE IN WAKE OF STRONG TROUGH NOW OFFSHORE CA/ORE. HOWEVER...LARGE SCALE FORCING ASSOCIATED WITH UPSTREAM PERTURBATION SHOULD STEEPEN LOW-MIDLEVEL LAPSE RATES...IN ENVIRONMENT OF WEAK CINH AND MARINE MOISTURE. THIS WILL SUPPORT ISOLATED/EPISODIC THUNDER RISK FOR PORTIONS WRN WA/ORE. ...ERN NC... TSTM OUTLOOK IS MRGL AND VALID FOR FIRST FEW HOURS OF PERIOD. GEN TSTM REGIME ALREADY DESCRIBED IN DAY-1 OUTLOOK MAY LINGER PAST 23/12Z BEFORE DEEP-TROPOSPHERIC CYCLONE AND ASSOCIATED WARM CONVEYOR EXIT AREA. ..EDWARDS.. 11/22/2006  From swody2 at goshenarc.org Thu Nov 23 05:14:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 00:14:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230517 SWODY2 SPC AC 230516 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 PM CST WED NOV 22 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE IS FORECAST TO PREVAIL ACROSS THE ERN CONUS THIS PERIOD...AS TROUGH OFF THE ATLANTIC COAST PROGRESSES EWD. MEANWHILE...TROUGH OVER THE WRN HALF OF THE CONUS AT THE START OF THE PERIOD IS FORECAST TO DEEPEN/EXPAND SLOWLY EWD. WITH SURFACE RIDGE FORECAST TO REMAIN OVER THE GULF OF MEXICO...MOISTURE RETURN INTO THE CENTRAL CONUS SHOULD PROVE INSUFFICIENT TO SUPPORT THUNDERSTORM DEVELOPMENT INVOF WEAK BAROCLINIC ZONE WHICH IS FORECAST TO BECOME ESTABLISHED OVER THE CENTRAL PLAINS. ELSEWHERE...DEEP MOIST CONVECTION IS NOT ANTICIPATED THROUGH THE PERIOD. ..GOSS.. 11/23/2006  From swody2 at goshenarc.org Thu Nov 23 17:09:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 12:09:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231712 SWODY2 SPC AC 231710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST THU NOV 23 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... AN UPPER-LEVEL RIDGE IS FORECAST TO BE IN PLACE ACROSS THE ERN UNITED STATES FRIDAY. A SOUTHWEST FLOW REGIME SHOULD REMAIN IN PLACE ACROSS THE WRN AND CNTRL STATES. ALTHOUGH ADEQUATE LARGE-SCALE FORCING WILL EXIST ESPECIALLY IN THE NCNTRL UNITED STATES...MOISTURE WILL LIKELY NOT BE SUFFICIENT FOR THUNDERSTORM ACTIVITY ACROSS CONUS DURING THE DAY 2 PERIOD. ..BROYLES.. 11/23/2006  From swody2 at goshenarc.org Fri Nov 24 04:51:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 23:51:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240454 SWODY2 SPC AC 240453 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1053 PM CST THU NOV 23 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SLOW EWD PROGRESSION OF WRN CONUS LONG WAVE TROUGH /COMPRISED OF DISTINCT POLAR AND SUBTROPICAL JET BRANCHES/ IS FORECAST DURING THE DAY TWO PERIOD WITH PERSISTENT RIDGING OVER THE SERN STATES. SHORT WAVE TROUGH NOW NEAR 30N AND 126W IS FORECAST TO TRANSLATE THROUGH THE SUBTROPICAL BRANCH...EVENTUALLY LIFTING NEWD INTO THE UPPER MIDWEST SATURDAY NIGHT. IN THE LOW-LEVELS...PRIMARY BAROCLINIC ZONE WILL EXIST FROM LOW PRESSURE OVER THE NRN HIGH PLAINS EWD INTO THE UPPER GREAT LAKES WITH DOMINANT RIDGING FROM THE CANADIAN MARITIMES INTO THE GULF OF MEXICO. THIS RIDGING WILL TEND TO LIMIT THE DEGREE/QUALITY OF LOW-LEVEL MOISTURE RETURN ACROSS TX/LA. ...PACIFIC NW COAST TO NRN ROCKIES... COLD MID-LEVEL TEMPERATURES /-25 TO -35 C AT 500 MB/ WILL BE MAINTAINED THROUGH THE PERIOD ON CYCLONIC SIDE OF POLAR JET...EFFECTIVELY CONTRIBUTING TO STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. STRONG SHORT WAVE TROUGH INITIALLY OVER WA/ORE SATURDAY MORNING WILL SHIFT EWD...LIKELY PROVIDING SUFFICIENT BACKGROUND DESTABILIZATION/FORCING FOR ISOLATED TSTM DEVELOPMENT ACROSS THE NRN INTERMOUNTAIN REGION INTO SATURDAY EVENING. FARTHER UPSTREAM ALONG THE WA/ORE COAST...THE STEEP LAPSE RATES COUPLED WITH MOIST ONSHORE FLOW AND HEIGHT FALLS AHEAD OF NEXT SHORT WAVE TROUGH DROPPING SEWD FROM THE GULF OF AK WILL BE SUPPORTIVE OF ISOLATED TSTMS AS WELL. ...SWRN DESERTS INTO THE FOUR CORNERS REGION... SHORT WAVE TROUGH EMBEDDED IN SUBTROPICAL BRANCH INITIALLY ALONG OR JUST OFF THE SRN CA COAST IS EXPECTED TO MOVE EWD THROUGH THE LOWER CO VALLEY AND EVENTUALLY THE FOUR CORNERS REGION SATURDAY AND SATURDAY NIGHT. DEVELOPING STEEP LAPSE RATES AHEAD OF THIS FEATURE WILL LARGELY CONTRIBUTE TO WEAK CONVECTIVE INSTABILITY...ESPECIALLY DURING THE MID/LATE AFTERNOON AND EARLY EVENING HOURS...FOR ISOLATED TO SCATTERED TSTMS FROM AZ NEWD INTO WRN/CNTRL CO. ...UPPER MIDWEST... AS MENTIONED ABOVE...LEAD SRN BRANCH IMPULSE NOW NEAR 30N AND 126W IS FORECAST TO LIFT NEWD TOWARD THE REGION...THOUGH LATEST MODEL GUIDANCE INDICATE SLIGHT TIMING DIFFERENCES. IT APPEARS SOME POTENTIAL EXISTS FOR AT LEAST A FEW ELEVATED TSTMS...MAINLY SATURDAY NIGHT...AS LOW-LEVEL WAA AND ISENTROPIC ASCENT INCREASE AHEAD OF THE SHORT WAVE TROUGH. ..MEAD.. 11/24/2006  From swody2 at goshenarc.org Fri Nov 24 17:25:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Nov 2006 12:25:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241727 SWODY2 SPC AC 241725 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CST FRI NOV 24 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... A SOUTHWEST FLOW PATTERN WILL REMAIN IN PLACE THROUGH SATURDAY ACROSS MOST OF THE CONUS WITH A BROAD UPPER-LEVEL TROUGH OVER THE WRN UNITED STATES. ISOLATED THUNDERSTORM ACTIVITY MAY OCCUR IN THE HIGHER TERRAIN OF THE PACIFIC NORTHWEST AND IN THE FOUR CORNERS REGION DUE TO DAYTIME HEATING AND COLD TEMPS ALOFT. OTHER CONVECTION MAY DEVELOP ALONG A WARM FRONT SATURDAY NIGHT AS A BOUNDARY LIFTS NWD ACROSS THE UPPER MIDWEST. NO SEVERE THREAT IS EXPECTED WITH ANY OF THE THUNDERSTORM ACTIVITY ACROSS THE CONUS SATURDAY AND SATURDAY NIGHT. ..BROYLES.. 11/24/2006  From swody2 at goshenarc.org Sat Nov 25 05:26:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Nov 2006 00:26:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250529 SWODY2 SPC AC 250527 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST FRI NOV 24 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG HEIGHT FALLS ARE FORECAST FROM THE PACIFIC NW INTO NRN/CNTRL CA AS INTENSE MID AND UPPER-LEVEL JET STREAKS DIG SEWD FROM THE NERN PACIFIC OCEAN TOWARD THE GREAT BASIN. AS THIS OCCURS... AMPLIFICATION OF WRN U.S. TROUGH WILL OCCUR...ANCHORED BY VORTEX OVER SRN BRITISH COLUMBIA/WA. MEANWHILE...A SUBTROPICAL JET BRANCH WILL REMAIN ACTIVE WITH SEVERAL EMBEDDED SHORT WAVE TROUGHS TRANSLATING NEWD THROUGH THE MEAN FLOW REGIME FROM NRN MEXICO TO THE UPPER GREAT LAKES. IN THE LOW-LEVELS...ARCTIC COLD FRONT FROM THE NRN ROCKIES INTO UPPER MS VALLEY WILL SLOWLY PUSH SWD THROUGH THE DAY TWO PERIOD. ELSEWHERE...A DEEP SURFACE LOW WILL MOVE INTO WA/ORE WITH ATTENDANT PACIFIC FRONT PUSHING SEWD TOWARD THE GREAT BASIN. ...PACIFIC NW COAST SWD ALONG THE NRN/CNTRL CA COAST... AS MENTIONED ABOVE...STRONG HEIGHT FALLS ARE FORECAST ACROSS THE REGION SUNDAY/SUNDAY NIGHT AS MEAN TROUGH INTENSIFIES ON CYCLONIC SIDE OF MID AND UPPER-LEVEL JET STREAKS DIGGING SSEWD ALONG THE PACIFIC COAST. AS THIS OCCURS LAPSE RATES WILL STEEPEN OWING TO THE FORCING/COOLING ALOFT WITH POCKETS OF WEAK CONVECTIVE INSTABILITY DEVELOPING. IT APPEARS THE BEST POTENTIAL FOR A FEW TSTMS WILL EXIST ALONG PACIFIC COLD FRONT AS IT APPROACHES THE COAST...AS WELL AS WITHIN MOIST...POST-FRONTAL ONSHORE FLOW REGIME DEVELOPING SUNDAY NIGHT. ...UPPER MIDWEST INTO MIDDLE/LOWER MO VALLEY... LOW-LEVEL MOISTURE IS EXPECTED TO REMAIN RATHER LIMITED WITH DEWPOINTS COMMONLY IN THE 40S TO PERHAPS LOWER 50S AHEAD OF SURFACE FRONT. HOWEVER...A PLUME OF RELATIVELY STEEP MID-LEVEL LAPSE RATES ORIGINATING FROM THE CNTRL ROCKIES WILL BE ADVECTED NEWD INTO THE REGION AHEAD OF SHORT WAVE TROUGH LIFTING OUT OF THE CNTRL HIGH PLAINS....EFFECTIVELY CONTRIBUTING TO WEAK CONVECTIVE INSTABILITY. SUSTAINED FRONTAL CONVERGENCE COUPLED WITH INCREASED LARGE-SCALE FORCING FOR ASCENT WITH APPROACHING SHORT WAVE TROUGH WILL LIKELY CONTRIBUTE TO THE DEVELOPMENT OF ISOLATED TSTMS LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. SOME SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...THOUGH THE MARGINAL INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ..MEAD.. 11/25/2006  From swody2 at goshenarc.org Sat Nov 25 17:26:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Nov 2006 12:26:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 251729 SWODY2 SPC AC 251727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST SAT NOV 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... AN UPPER-LEVEL TROUGH OVER THE PACIFIC NORTHWEST WILL DRIFT ENEWD INTO SRN CANADA TONIGHT AS ANOTHER SHORTWAVE TROUGH REPLACES IT IN THE NWRN UNITED STATES SUNDAY. THUNDERSTORM ACTIVITY MAY OCCUR IN THE COASTAL SECTIONS OF WA...ORE AND NRN CA AS STRONG LARGE-SCALE ASCENT ASSOCIATED WITH THE TROUGH MOVES INLAND SUNDAY AFTERNO0N. THE ONLY OTHER AREA ACROSS THE CONUS WITH POTENTIAL FOR CONVECTION WILL BE IN THE UPPER MIDWEST. A FEW THUNDERSTORMS MAY OCCUR ALONG A COLD FRONT FORECAST TO MOVE SEWD ACROSS IA SUNDAY. THE THUNDERSTORM ACTIVITY ACROSS THE CONUS ON SUNDAY AND SUNDAY NIGHT SHOULD REMAIN WELL BELOW SEVERE LIMITS DUE TO WEAK INSTABILITY. ..BROYLES.. 11/25/2006  From swody2 at goshenarc.org Sun Nov 26 05:16:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Nov 2006 00:16:59 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260519 SWODY2 SPC AC 260518 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 PM CST SAT NOV 25 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SLOW EWD PROGRESSION/DEVELOPMENT OF WRN U.S. LONG WAVE TROUGH /ANCHORED BY VORTEX OVER THE PACIFIC NW/ IS FORECAST DURING THE DAY TWO PERIOD WITH PERSISTENT RIDGING IN THE SE. WITHIN THIS REGIME...ELONGATED...LEAD SHORT WAVE TROUGH INITIALLY FROM THE MID MO VALLEY SWWD TO THE SRN HIGH PLAINS MONDAY MORNING WILL LIFT NEWD INTO THE UPPER GREAT LAKES WHILE STRONGER UPSTREAM SYSTEM EJECTS FROM THE ROCKIES INTO THE GREAT PLAINS MONDAY NIGHT INTO TUESDAY MORNING. IN THE LOW-LEVELS...SURFACE FRONT EXTENDING FROM LOW PRESSURE OVER SWRN KS NEWD INTO THE MIDWEST WILL LIFT NWD THROUGH THE PERIOD IN RESPONSE TO INCREASING PRESSURE FALLS OVER THE NRN/CNTRL HIGH PLAINS. A WEAK LOW ATTENDANT TO THE LEAD SHORT WAVE TROUGH IS FORECAST TO DEVELOP NEWD ALONG THIS RETREATING BOUNDARY WHILE PRIMARY CYCLONE CONCURRENTLY DEEPENS OVER WY. THIS STRONGER LOW IS THEN EXPECTED TO DEVELOP GENERALLY EWD INTO SD BY TUESDAY MORNING. ...CNTRL/ERN KS THROUGH THE MID MO VALLEY... LATEST SHORT RANGE MODEL GUIDANCE REMAINS CONSISTENT IN SUGGESTING THAT SEPARATE CONVECTIVE EPISODES ARE POSSIBLE DURING THE DAY TWO PERIOD. ISOLATED/SCATTERED TSTMS /MAINLY ELEVATED/ ARE EXPECTED TO BE ONGOING OR DEVELOP EARLY IN THE PERIOD MONDAY MORNING OVER THE MID MO VALLEY PERHAPS INTO CNTRL IA...DRIVEN BY LOW-LEVEL WAA ALONG NOSE OF SWLY LLJ AND DEEPER LAYER FORCING FOR ASCENT ASSOCIATED WITH LEAD SHORT WAVE TROUGH. OVER THE COURSE OF THE DAY...THIS ACTIVITY IS FORECAST TO SHIFT INTO PARTS OF SRN MN/SWRN WI WITH BACKBUILDING DEVELOPMENT POSSIBLE INTO ERN KS. LAPSE RATES AND RESULTANT INSTABILITY ARE EXPECTED TO REMAIN QUITE MARGINAL WITH STORMS LIKELY REMAINING BELOW SEVERE LEVELS. A POTENTIALLY GREATER THREAT OF ISOLATED...SEVERE STORMS WILL EXIST DURING THE LATTER HALF OF THE PERIOD IN ADVANCE OF STRONGER SHORT WAVE TROUGH MOVING OUT OF THE ROCKIES. BOUNDARY LAYER MOISTURE WILL REMAIN MODEST WITH DEWPOINTS COMMONLY IN THE LOW/MID 50S. HOWEVER...A PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL PRECEDE THIS STRONGER IMPULSE...CONTRIBUTING TO MUCAPES OF 500-900 J/KG. TSTMS ARE FORECAST TO BECOME INCREASINGLY LIKELY AFTER 28/00Z ALONG LEE TROUGH/WEAK DRYLINE FROM PORTIONS OF WRN OK INTO CNTRL KS. ACTIVITY SHOULD TEND TO INCREASE IN COVERAGE AND INTENSITY MONDAY NIGHT ACROSS CNTRL/ERN KS INTO THE MID MO VALLEY AS STRONGER DYNAMIC FORCING OVERSPREADS REGION. FORECAST SOUNDINGS INDICATE THAT VERTICAL SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF ORGANIZED/ROTATING STORMS CAPABLE OF SEVERE HAIL AND LOCALLY DAMAGING WINDS. GIVEN THAT THIS GREATEST STORM THREAT WILL EXIST DURING THE NIGHTTIME HOURS...PRIMARY UNCERTAINTIES ARE DEGREE OF INSTABILITY AND WHETHER OR NOT STORMS WILL REMAIN ROOTED IN BOUNDARY LAYER OR BECOME SLIGHTLY ELEVATED. THEREFORE...ONLY LOW SEVERE PROBABILITIES HAVE BEEN INCLUDED. ..MEAD.. 11/26/2006  From swody2 at goshenarc.org Sun Nov 26 17:27:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Nov 2006 12:27:49 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261730 SWODY2 SPC AC 261728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST SUN NOV 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... A BROAD ZONE OF SOUTHWEST FLOW WILL REMAIN IN PLACE ACROSS THE CONUS THROUGH THE DAY 2 PERIOD AS A POWERFUL UPPER-LOW DEVELOPS AND MOVES INLAND ACROSS THE PACIFIC NORTHWEST. SOME THUNDERSTORM ACTIVITY MAY DEVELOP IN THE PACIFIC NORTHWEST AND IN THE INTERMOUNTAIN WEST MONDAY ASSOCIATED WITH THE STRONG ASCENT AHEAD OF THE APPROACHING LOW/TROUGH. THE GREATEST THREAT FOR THUNDERSTORM ACTIVITY SHOULD OCCUR IN THE PLAINS AND UPPER MIDWEST WHERE A STRONG LOW-LEVEL JET IS FORECAST TO DEVELOP MONDAY AND MONDAY NIGHT. ALTHOUGH INSTABILITY/MOISTURE RETURN WILL REMAIN WEAK ACROSS THE REGION...SCATTERED THUNDERSTORMS MAY DEVELOP IN A REGION OF WARM ADVECTION FROM OK/N TX EXTENDING NNEWD INTO IA/MN AND WI. THUNDERSTORM COVERAGE WOULD LIKELY BE GREATEST FROM NEAR PEAK HEATING INTO THE EVENING HOURS AS THE LOW-LEVEL JET STRENGTHENS. A FEW OF THE BETTER ORGANIZED THUNDERSTORMS COULD CONTAIN HAIL DUE TO COLD TEMPS ALOFT AND STEEPENING LAPSE RATES AS MID-LEVEL FLOW STRENGTHENS AHEAD OF A STRONG MID-LEVEL JET EJECTING OUT OF THE BASE OF THE TROUGH. ..BROYLES.. 11/26/2006  From swody2 at goshenarc.org Mon Nov 27 05:47:48 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 27 Nov 2006 00:47:48 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270550 SWODY2 SPC AC 270548 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST SUN NOV 26 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DYNAMIC LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD CHARACTERIZED BY DEEP TROUGH SHIFTING EWD THROUGH THE INTERMOUNTAIN W INTO THE PLAINS AND PERSISTENT RIDGING OVER THE SERN STATES. WITHIN THIS BROADER PATTERN...SHORT WAVE TROUGH INITIALLY OVER THE NRN/CNTRL PLAINS WILL LIFT NNEWD INTO MANITOBA AND WRN ONTARIO...POTENTIALLY FORMING A CLOSED LOW OVER THIS REGION. MEANWHILE...STRONG MID AND UPPER-LEVEL JET STREAKS FROM THE PACIFIC NW COAST TO THE GREAT BASIN WILL DIG SEWD WITH HEIGHT FALLS DEVELOPING THROUGH THE FOUR CORNERS REGION INTO SRN HIGH PLAINS. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO LEAD SHORT WAVE TROUGH WILL DEVELOP NEWD FROM NRN NEB OR SRN SD INTO WRN ONTARIO WITH SECONDARY LOW PRESSURE DEVELOPING ALONG ARCTIC COLD FRONT SURGING SWD THROUGH THE CNTRL INTO SRN HIGH PLAINS. ...CNTRL LOW PLAINS/LOWER MO VALLEY INTO THE UPPER GREAT LAKES... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING TUESDAY MORNING FROM PORTIONS OF THE MID MO VALLEY AND MIDWEST SWD INTO THE ERN KS AND WRN/NRN MO. DPVA ASSOCIATED WITH LEAD SHORT WAVE TROUGH COUPLED WITH LOWER LEVEL ISENTROPIC ASCENT WILL BE THE PRIMARY MECHANISMS FOCUSING THIS ACTIVITY WITHIN THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY MODEST MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 500-700 J/KG. SOME OF THE STRONGER STORMS WILL BE CAPABLE OF SMALL TO POTENTIALLY MARGINALLY SEVERE HAIL THROUGH THE MORNING...THOUGH THIS THREAT APPEARS TOO MARGINAL FOR INCLUSION OF SEVERE PROBABILITIES. THESE STORMS SHOULD TEND TO MOVE/DEVELOP NEWD INTO THE UPPER GREAT LAKES TUESDAY AFTERNOON WITH STORMS WEAKENING WITH TIME AS THEY BECOME INCREASINGLY ELEVATED IN PROGRESSIVELY MORE STABLE ENVIRONMENT. ADDITIONAL STORM DEVELOPMENT IS POSSIBLE ALONG COLD FRONT TUESDAY NIGHT FROM PORTIONS OF CNTRL/ERN IA SWWD INTO ERN KS/MO AS BOUNDARY ENCOUNTERS LOW-LEVEL MOISTURE AXIS. SOME THREAT OF ISOLATED...SEVERE STORMS WILL EXIST WITH THIS NOCTURNAL DEVELOPMENT...PARTICULARLY ACROSS ERN KS GIVEN THE STRONG VERTICAL SHEAR PROFILES FORECAST. NO SEVERE PROBABILITIES WILL BE INCLUDED AT THIS POINT DUE TO THE POTENTIAL LIMITING EFFECTS OF THE EXPECTED WEAK INSTABILITY. ..MEAD.. 11/27/2006  From swody2 at goshenarc.org Mon Nov 27 17:12:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 27 Nov 2006 12:12:28 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 271714 SWODY2 SPC AC 271713 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CST MON NOV 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT WAVE ENERGY ROTATING THROUGH LARGE SCALE WRN NORTH AMERICAN UPPER TROUGH WILL PRODUCE AREAS OF MODEST TO STRONG HEIGHT FALLS FROM THE ROCKIES TO THE CNTRL AND NRN PLAINS THROUGH TUESDAY. THIS WILL CAUSE THE AXIS OF THE LARGE SCALE TROUGH TO TRANSLATE EWD FROM THE INTERIOR NORTHWEST TO THE NRN ROCKIES/FOUR CORNERS REGIONS OVER THE NEXT COUPLE OF DAYS. MEANWHILE...A STRONG AND PERSISTENT UPPER RIDGE WILL REMAIN NEARLY STATIONARY ACROSS THE SOUTHEAST AND ADJACENT ATLANTIC COASTAL WATERS. AN EXTENSIVE BELT OF STRONG SWLY MID LEVEL FLOW AND ASSOCIATED DEEP-LAYER BAROCLINIC ZONE WILL BE SITUATED BETWEEN THE WRN TROUGH AND SERN RIDGE. LIFT AND MOISTURE FLUX WITHIN WARM CONVEYOR BELT TO THE EAST OF SW/NE ORIENTED DEEP-LAYER BAROCLINIC ZONE WILL SUSTAIN SCATTERED TSTMS THIS PERIOD. ...SRN PLAINS ACROSS THE MO RIVER VALLEY... TSTMS...PRIMARILY ROOTED ABOVE A MORE STABLE BOUNDARY LAYER...ARE POSSIBLE TUESDAY MORNING FROM THE RED RIVER VALLEY OF NERN TX/SERN OK...NNEWD ACROSS THE MID TO LOWER MO RIVER VALLEY. CONVECTIVE ACTIVITY APPEARS MOST LIKELY NEAR THE NOSE OF THE LLJ...AND IN ASSOCIATION WITH STRONGER DYNAMIC FORCING AND STEEPER LAPSE RATES ACCOMPANYING A LOW AMPLITUDE SHORT WAVE TROUGH EJECTING NEWD ACROSS THE CNTRL PLAINS. MUCAPE VALUES OF 500-1000 J/KG ARE FORECAST ACROSS THE PLAINS REGIONS AND A COUPLE OF THE STRONGER STORM UPDRAFTS COULD PRODUCE SMALL TO MARGINALLY SEVERE HAIL...FROM ERN NEB ACROSS IA AND NRN MO...INTO THE AFTERNOON. STRONGER FORCING ASSOCIATED WITH THE LEAD SHORT WAVE TROUGH WILL LIFT AWAY FROM THE INSTABILITY AXIS THROUGH THE FIRST PART OF THE DAY AND SEVERE HAIL POTENTIAL CURRENTLY APPEARS TOO LIMITED IN TIME/SPACE TO JUSTIFY A PROBABILITY FORECAST. ACTIVITY WILL TEND TO MOVE/DEVELOP NEWD TOWARD THE WRN GREAT LAKES THROUGH THE AFTERNOON WITH STORMS GENERALLY WEAKENING WITH TIME. A REPRIEVE FROM DEEP CONVECTION MAY OCCUR FOR A TIME TUESDAY EVENING BETWEEN THE NRN PLAINS/GREAT LAKES SHORT WAVE TROUGH AND THE NEXT UPSTREAM IMPULSE APPROACHING THE PLAINS FROM THE ROCKIES. LIFT ASSOCIATED WITH THIS NEXT SYSTEM SHOULD ENHANCE CONVERGENCE AND RESULT IN POSSIBLE TSTM DEVELOPMENT ALONG THE COLD FRONT TUESDAY NIGHT AND EARLY WEDNESDAY MORNING...FROM NRN IA ACROSS MN/WI. ADDITIONAL ISOLATED STORMS MAY FORM LATE IN THE PERIOD WITHIN PERSISTENT WARM/MOIST CONVEYOR BELT...AND AHEAD OF THE COLD FRONT...FROM CNTRL OK ACROSS THE OZARKS. WHILE ISOLATED HAIL WILL BE POSSIBLE WITH THIS NOCTURNAL DEVELOPMENT GIVEN STRONG VERTICAL SHEAR AND INCREASINGLY STRONG FORCING...OVERALL SEVERE POTENTIAL SHOULD BE LIMITED BY WEAK INSTABILITY. ..CARBIN.. 11/27/2006  From swody2 at goshenarc.org Tue Nov 28 09:07:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 28 Nov 2006 04:07:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280909 SWODY2 SPC AC 280907 DAY 2 CONVECTIVE OUTLOOK RESENT 4 NWS STORM PREDICTION CENTER NORMAN OK 0307 AM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN KS/SWRN MO SWD INTO N-CNTRL AND NERN TX... ...SYNOPSIS... A PROGRESSIVE WAVE TRAIN IS FORECAST FROM THE NERN PACIFIC AND WRN CANADA EWD INTO CNTRL CANADA AND THE N-CNTRL TIER OF STATES. MEANWHILE...A SLOWER EWD MOVEMENT OF DEEP...LOW LATITUDE TROUGH IS EXPECTED FROM THE SRN ROCKIES INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SURFACE COLD FRONT INITIALLY FROM LOW PRESSURE OVER LAKE SUPERIOR SWWD TO SECONDARY LOW PRESSURE OVER THE TX S PLAINS WILL PUSH SEWD THROUGH THE PERIOD...EXTENDING FROM CNTRL LOWER MI TO THE LOWER RIO GRANDE VALLEY BY THURSDAY MORNING. ...LOWER MO VALLEY SWD INTO NERN TX... 28/00Z SOUNDINGS WITHIN LOW-LEVEL MOISTURE AXIS ACROSS THE SRN PLAINS INDICATE THAT PRE-FRONTAL AIR MASS IS ALREADY WEAKLY TO MODERATELY UNSTABLE WITH MUCAPES OF 500-1000 J/KG. PERSISTENT SLY FLOW AHEAD OF COLD FRONT WILL RESULT IN A FURTHER INCREASE IN BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA...SUPPORTING MUCAPES OF 1000-1500 J/KG BY WEDNESDAY AFTERNOON. INSTABILITY IS FORECAST TO DECREASE WITH NEWD EXTENT WITH MUCAPES OF 500-800 J/KG MORE LIKELY TOWARD THE LOWER MO VALLEY. TSTMS ARE EXPECTED TO BE ONGOING WEDNESDAY MORNING ALONG FRONT OVER PORTIONS OF IA WITHIN WEAKLY UNSTABLE AIR MASS. INCREASING HEIGHT FALLS/DYNAMIC LARGE-SCALE FORCING FOR ASCENT SHOULD SUPPORT SWWD STORM DEVELOPMENT ALONG/AHEAD OF FRONT BY AFTERNOON AS BOUNDARY LAYER BECOMES INCREASINGLY UNSTABLE. VERTICAL SHEAR PROFILES ALONG LENGTH OF FRONTAL ZONE WILL BE QUITE FAVORABLE FOR ORGANIZED STORMS INCLUDING SUPERCELLS GIVEN 50-65 KT OF EFFECTIVE BULK SHEAR. CURRENTLY...IT APPEARS THAT INSTABILITY WILL REMAIN QUITE MARGINAL ACROSS NRN AND CNTRL MO...WHICH COULD POTENTIALLY LIMIT A MORE SUBSTANTIAL SEVERE THREAT. MODEL TRENDS WILL BE MONITORED AND AN UPGRADE TO SLIGHT RISK MAY BE NECESSARY IN LATER OUTLOOKS. AN APPARENT GREATER SEVERE STORM THREAT WILL EXIST FROM SERN KS/SWRN MO SSWWD INTO THE ERN HALF OF OK AND N-CNTRL/NERN TX WHERE AIR MASS IS FORECAST TO BECOME MORE UNSTABLE. SUPERCELLS ARE POSSIBLE GIVEN THE STRONGLY SHEARED ENVIRONMENT...THOUGH CONVECTION SHOULD TEND TO EVOLVE TO MORE OF A LINEAR STRUCTURE OWING TO THE ANAFRONTAL CHARACTERISTICS OF THE COLD FRONT. DAMAGING WINDS AND SEVERE HAIL APPEAR TO BE THE MAIN THREATS WITH THE STRONGEST STORMS. MORE BROKEN...CELLULAR STORM DEVELOPMENT WILL BE POSSIBLE LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT SWD ALONG TROUGH OR DRYLINE ATTENDANT TO COLD FRONT INTO N-CNTRL AND CNTRL TX. SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE HAIL AND PERHAPS A COUPLE OF TORNADOES OWING TO THE ANTICIPATED MORE DISCRETE NATURE OF THE STORMS. ACTIVITY SHOULD EVOLVE INTO A QUASI-LINEAR MCS OVERNIGHT AS COLD FRONT OVERTAKES TROUGH/DRYLINE WITH ASSOCIATED WIND/HAIL THREAT DEVELOPING TOWARD THE ARKLATEX. ..MEAD.. 11/28/2006  From swody2 at goshenarc.org Tue Nov 28 17:34:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 28 Nov 2006 12:34:59 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281737 SWODY2 SPC AC 281735 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 AM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX/OK NEWD TO WRN IL... ...SYNOPSIS... SIGNIFICANT LARGE SCALE PATTERN CHANGE IS FORECAST OVER THE CNTRL U.S THROUGH WEDNESDAY AS A DEEP UPPER TROUGH...CURRENTLY ENCOMPASSING THE INTERMOUNTAIN WEST...TRANSLATES EWD. WHILE A PORTION OF SHORT WAVE ENERGY ASSOCIATED WITH THE LARGER SCALE TROUGH SYSTEM EJECTS NEWD FROM MT INTO SRN CANADA...ANOTHER VIGOROUS LOBE OF VORTICITY AND ITS ASSOCIATED JET SEGMENT WILL TRACK ACROSS THE GREAT BASIN AREA THROUGH TONIGHT...AND RESULT IN HEIGHT FALLS SPREADING EWD/SEWD ACROSS THE SRN HIGH PLAINS THROUGH THURSDAY MORNING. DYNAMIC FORCING ACCOMPANYING THE EWD TRANSITION OF THE LARGE SCALE TROUGH WILL ENHANCE DEEP-LAYER FRONTOGENESIS AND LIFT ALONG A STRONG COLD FRONT FORECAST TO SURGE INTO THE WRN GREAT LAKES...MIDWEST...AND SRN PLAINS REGIONS THROUGH LATE TOMORROW NIGHT. ...NRN TX...ERN OK...OZARKS... MOIST AXIS HAS BECOME WELL ESTABLISHED ACROSS THE SRN PLAINS GIVEN PERSISTENT SLY LOW LEVEL FLOW AND PASSAGE OF DEAMPLIFYING SHORT WAVE TROUGH EARLIER TODAY. CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT WILL MAINTAIN LOW TO MID 60S F DEWPOINTS ACROSS THE SRN PLAINS AND SUPPORT MUCAPES CLIMBING TO NEAR 1000 J/KG PERHAPS AS EARLY AS WEDNESDAY MORNING. LATEST NAM AND GFS ARE TRENDING A BIT FASTER WITH COLD FRONTAL PASSAGE ACROSS NWRN/CNTRL OK BY WEDNESDAY AFTERNOON BIT THERE ARE DIFFERENCES IN CONVECTIVE INITIATION NEAR THE FRONT WITH THE GFS SUGGESTING AN EARLIER START TO MORE VIGOROUS DEEP CONVECTION ACROSS OK/NORTH TX BY AFTERNOON. GIVEN FAVORABLE LARGE SCALE SUPPORT IN THE FORM OF INCREASINGLY DIFFLUENT/DIVERGENT FLOW IN RIGHT ENTRANCE REGION OF INTENSIFYING UPPER JET...AND GENERALLY WEAK CAP ACROSS MOIST AND UNSTABLE PRE-FRONTAL AIR MASS...TSTMS SHOULD INCREASE THROUGH THE AFTERNOON. SHEAR ACROSS THE REGION WILL STRENGTHEN THROUGH THE DAY AND SUPPORT ORGANIZED AND PERSISTENT UPDRAFTS CAPABLE OF HAIL AND DAMAGING WINDS. A SUPERCELL TORNADO AND/OR VERY LARGE HAIL THREAT APPEARS POSSIBLE ACROSS THE RED RIVER REGION DURING THE AFTERNOON OR EARLY EVENING WHERE THERMAL TROUGH/COLD FRONT INTERSECTION MAY ENHANCE LOW LEVEL MESOSCALE FORCING. BULK OF CONVECTION ACROSS THE REGION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING SEWD ACROSS THE AREA THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE ACROSS PARTS OF NERN OK AND NCNTRL TX INTO THE LATER EVENING. ...NRN MO TO IL... MOIST AXIS WILL BE NARROW AND CAPE WILL BE WEAKER FROM THE OZARKS NEWD ACROSS THE MS VALLEY INTO WRN IL. NONETHELESS...LIFT ALONG THE FRONT...AND INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES...SUGGEST SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT OF EITHER MARGINALLY SEVERE HAIL AND/OR HIGH WINDS. GIVEN CONSENSUS IN AVAILABLE GUIDANCE THAT A NARROW CORRIDOR OF AT LEAST 500 J/KG MUCAPE WILL BE AVAILABLE TO CONVECTION DEVELOPING NEAR THE ADVANCING FRONT...AND STRONG SIGNAL THAT VIGOROUS CONVECTIVE DEVELOPMENT WILL OCCUR WITHIN HIGH MOMENTUM REGIME...NEWD EXTENSION OF THE HIGHER SEVERE PROBABILITIES APPEARS PRUDENT AT THIS TIME. ..CARBIN.. 11/28/2006  From swody2 at goshenarc.org Wed Nov 29 05:28:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 00:28:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290530 SWODY2 SPC AC 290528 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST TUE NOV 28 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... ...SYNOPSIS... INTENSIFICATION OF SRN STREAM TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS IT TRANSLATES EWD THROUGH THE SRN PLAINS...PRIOR TO BECOMING NEGATIVELY TILTED AND EJECTING MORE NEWD INTO THE MID MS AND LOWER OH VALLEYS BY FRIDAY MORNING. AN ACCOMPANYING BELT OF STRONG /80-100 KT AT 500 MB/ MID-LEVEL FLOW WILL PROPAGATE THROUGH THE TROUGH BASE...SPREADING THROUGH THE ARKLATEX...MID SOUTH AND LOWER MS VALLEY REGIONS. IN THE LOW-LEVELS...COLD FRONT INITIALLY EXTENDING FROM CNTRL LOWER MI SWWD INTO SERN TX WILL RAPIDLY PUSH SEWD/EWD WITH SECONDARY CYCLOGENESIS FORECAST OVER THE LOWER MS VALLEY THURSDAY. DIFFERENCES EXIST IN LATEST SHORT RANGE MODEL GUIDANCE WITH REGARD TO THE TRACK AND STRENGTH OF THIS FEATURE...BUT IN GENERAL IT IS FORECAST TO DEVELOP NEWD ALONG COLD FRONT INTO THE UPPER OH VALLEY BY FRIDAY MORNING. ...S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... LARGE-SCALE PATTERN CONTINUES TO INDICATE THE POTENTIAL FOR A LOW INSTABILITY - HIGH SHEAR SERIAL-TYPE WIND EVENT ACROSS THE REGION THURSDAY INTO THURSDAY NIGHT. 29/00Z OBSERVED SOUNDINGS...CURRENT SURFACE OBSERVATIONS AND GOES SOUNDER PW LOOP ALL INDICATE A FAIRLY RAPID RETURN OF LOW-LEVEL MOISTURE THROUGH THE SABINE AND LOWER MS RIVER VALLEYS NWD INTO THE MID SOUTH AND WRN TN VALLEY WITH 60F DEWPOINTS TO LIT AND THE MS DELTA. SWLY LLJ WILL BE MAINTAINED AHEAD OF EVOLVING UPPER SYSTEM...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD WITH 60F DEWPOINTS INTO KY...AND MID/UPPER 60S INTO THE LOWER MS VALLEY BY THURSDAY AFTERNOON. LATEST MODEL GUIDANCE CONTINUES TO INDICATE ONLY MARGINAL INSTABILITY /MUCAPES OF 200-600 J PER KG/ AHEAD OF SURFACE FRONT THURSDAY...LARGELY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE THE MARGINAL INSTABILITY...INCREASED LARGE-SCALE FORCING...SLAB ASCENT ALONG COLD FRONT AND STRONG VERTICAL SHEAR ALL SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD INTO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. THE STRENGTH OF THE AMBIENT WIND FIELDS WILL SUPPORT STORM MOTIONS OF 45-50+KT WITH THE POTENTIAL FOR CORRIDORS OF WIND DAMAGE. LOW-TOPPED SUPERCELLS WILL ALSO BE POSSIBLE...BOTH EMBEDDED IN LINE OR FORMING IN MORE DISCRETE FASHION AHEAD OF PRIMARY CONVECTIVE SYSTEM. GIVEN THE LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR...THE THREAT FOR ISOLATED TORNADOES WILL EXIST. THIS IS ESPECIALLY THE CASE INVOF DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. THIS CONVECTIVE LINE WILL RAPIDLY SHIFT EWD THROUGH THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THURSDAY NIGHT WITH A CONTINUING THREAT OF DAMAGING WINDS AND PERHAPS A FEW TORNADOES. ..MEAD.. 11/29/2006  From swody2 at goshenarc.org Wed Nov 29 07:05:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 02:05:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290707 SWODY2 SPC AC 290528 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST TUE NOV 28 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... ...SYNOPSIS... INTENSIFICATION OF SRN STREAM TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS IT TRANSLATES EWD THROUGH THE SRN PLAINS...PRIOR TO BECOMING NEGATIVELY TILTED AND EJECTING MORE NEWD INTO THE MID MS AND LOWER OH VALLEYS BY FRIDAY MORNING. AN ACCOMPANYING BELT OF STRONG /80-100 KT AT 500 MB/ MID-LEVEL FLOW WILL PROPAGATE THROUGH THE TROUGH BASE...SPREADING THROUGH THE ARKLATEX...MID SOUTH AND LOWER MS VALLEY REGIONS. IN THE LOW-LEVELS...COLD FRONT INITIALLY EXTENDING FROM CNTRL LOWER MI SWWD INTO SERN TX WILL RAPIDLY PUSH SEWD/EWD WITH SECONDARY CYCLOGENESIS FORECAST OVER THE LOWER MS VALLEY THURSDAY. DIFFERENCES EXIST IN LATEST SHORT RANGE MODEL GUIDANCE WITH REGARD TO THE TRACK AND STRENGTH OF THIS FEATURE...BUT IN GENERAL IT IS FORECAST TO DEVELOP NEWD ALONG COLD FRONT INTO THE UPPER OH VALLEY BY FRIDAY MORNING. ...S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... LARGE-SCALE PATTERN CONTINUES TO INDICATE THE POTENTIAL FOR A LOW INSTABILITY - HIGH SHEAR SERIAL-TYPE WIND EVENT ACROSS THE REGION THURSDAY INTO THURSDAY NIGHT. 29/00Z OBSERVED SOUNDINGS...CURRENT SURFACE OBSERVATIONS AND GOES SOUNDER PW LOOP ALL INDICATE A FAIRLY RAPID RETURN OF LOW-LEVEL MOISTURE THROUGH THE SABINE AND LOWER MS RIVER VALLEYS NWD INTO THE MID SOUTH AND WRN TN VALLEY WITH 60F DEWPOINTS TO LIT AND THE MS DELTA. SWLY LLJ WILL BE MAINTAINED AHEAD OF EVOLVING UPPER SYSTEM...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD WITH 60F DEWPOINTS INTO KY...AND MID/UPPER 60S INTO THE LOWER MS VALLEY BY THURSDAY AFTERNOON. LATEST MODEL GUIDANCE CONTINUES TO INDICATE ONLY MARGINAL INSTABILITY /MUCAPES OF 200-600 J PER KG/ AHEAD OF SURFACE FRONT THURSDAY...LARGELY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE THE MARGINAL INSTABILITY...INCREASED LARGE-SCALE FORCING...SLAB ASCENT ALONG COLD FRONT AND STRONG VERTICAL SHEAR ALL SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD INTO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. THE STRENGTH OF THE AMBIENT WIND FIELDS WILL SUPPORT STORM MOTIONS OF 45-50+KT WITH THE POTENTIAL FOR CORRIDORS OF WIND DAMAGE. LOW-TOPPED SUPERCELLS WILL ALSO BE POSSIBLE...BOTH EMBEDDED IN LINE OR FORMING IN MORE DISCRETE FASHION AHEAD OF PRIMARY CONVECTIVE SYSTEM. GIVEN THE LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR...THE THREAT FOR ISOLATED TORNADOES WILL EXIST. THIS IS ESPECIALLY THE CASE INVOF DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. THIS CONVECTIVE LINE WILL RAPIDLY SHIFT EWD THROUGH THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THURSDAY NIGHT WITH A CONTINUING THREAT OF DAMAGING WINDS AND PERHAPS A FEW TORNADOES. ..MEAD.. 11/29/2006  From swody2 at goshenarc.org Wed Nov 29 17:28:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 12:28:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291731 SWODY2 SPC AC 291729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CST WED NOV 29 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST ACROSS THE MS/TN AND LOWER OH VALLEYS TO SRN APPALACHIANS... ...SYNOPSIS... POWERFUL AND PROGRESSIVE SHORT WAVE IMPULSE WILL INTENSIFY THROUGH THE DAY TWO PERIOD ACROSS THE SRN PLAINS BEFORE TAKING ON A NEGATIVE TILT AND EJECTING NEWD FROM THE OZARKS TO THE OH VALLEY BY FRIDAY. IN ADDITION TO SIGNIFICANT 12H 500MB HEIGHT FALLS OF AROUND 300M ACROSS THE MO BOOTHEEL/SRN IL...AN INTENSE MID LEVEL JET OF 100-120KT WILL ROTATE THROUGH THE BASE OF THE EJECTING SHORT WAVE TROUGH...MOVING NEWD FROM THE ARKLATEX TO THE LOWER OH VALLEY AREA THROUGH THURSDAY NIGHT. VERY STRONG DYNAMIC AND KINEMATIC FORCING WILL INDUCE SURFACE CYCLOGENESIS ALONG AN ASSOCIATED COLD FRONT ACROSS ERN AR BY THURSDAY AFTERNOON. THE INTENSIFYING SURFACE CYCLONE IS FORECAST TO TRACK NEWD FROM ERN AR TO OH AS POTENT COLD FRONT SWEEPS EWD FROM THE MS VALLEY TO THE APPALACHIANS THROUGH EARLY FRIDAY. LARGE-SCALE PATTERN AS FORECAST BY NAM AND GFS HAS AN ANALOG IN 1996 NOVEMBER 7-8 EVENT WHICH RESULTED IN A SWATH OF SEVERE CONVECTIVE WIND EVENTS FROM LA TO OH. THIS ANALOG WAS ALSO A STRONGLY DYNAMIC...LOW CAPE/HIGH SHEAR...SEVERE WEATHER EPISODE. ...CNTRL GULF COAST ACROSS THE MS/TN AND LOWER OH VALLEYS...TO SRN APPALACHIANS... LATEST OBSERVATIONS INDICATE SURFACE DEWPOINTS INCREASING AND SPREADING NNEWD FROM THE GULF ACROSS THE LOWER MS RIVER VALLEY AND INTO THE LOWER OH VALLEY. WITH SWLY LLJ BEING MAINTAINED IN ADVANCE OF THE APPROACHING UPPER TROUGH...EXPECT AN INCREASINGLY MOIST BOUNDARY LAYER TO EXPAND NWD AND EWD ACROSS THE MS/TN AND OH VALLEYS THROUGH EARLY THURSDAY. HOWEVER...LATEST GUIDANCE CONTINUES TO INDICATE THAT ONLY MARGINAL INSTABILITY /MUCAPES OF 200-500 J PER KG/ WILL DEVELOP AHEAD OF THE INTENSE COLD FRONT ON THURSDAY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE INSTABILITY CONSTRAINTS...INCREASINGLY STRONG LARGE-SCALE FORCING AND SLAB ASCENT ACROSS COLD FRONT SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD TO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. STRENGTH OF THE DEEP-LAYER WIND FIELDS WILL SUPPORT STORM MOTIONS OF 50+KT WITH THE POTENTIAL FOR DAMAGING WINDS FROM A FAST MOVING LOW-TOPPED SQUALL LINE. GIVEN MAGNITUDE OF SHEAR AND FORCING...A FEW LOW-TOPPED SUPERCELLS ALSO APPEAR POSSIBLE...PERHAPS EMBEDDED WITHIN THE LINE...OR FORMING AS MORE DISCRETE STORMS AHEAD OF THE LINE. LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR IN THE WARM SECTOR SHOULD SUPPORT SOME THREAT FOR TORNADOES. POTENTIAL FOR TORNADOES MAY BE ESPECIALLY ENHANCED NEAR THE DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. SQUALL LINE...WITH THE POSSIBILITY OF LIMITED CG LIGHTNING DUE TO LOW CAPE...WILL SHIFT EAST ACROSS THE MS VALLEY AND INTO THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THROUGH THURSDAY NIGHT. WITH CONTINUING INTENSIFICATION OF THE DEEP-LAYER CYCLONE AND CONTINUED SHARPENING OF THE FRONTAL ZONE...THE THREAT OF DAMAGING WINDS AND ISOLATED TORNADOES MAY PERSIST INTO EARLY FRIDAY AS THE FRONT/SQUALL LINE MOVES EAST TOWARD THE UPPER OH VALLEY AND EXTENDS SWD TO THE SRN APPALACHIANS. ..CARBIN.. 11/29/2006  From swody2 at goshenarc.org Thu Nov 30 05:36:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 30 Nov 2006 00:36:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300538 SWODY2 SPC AC 300536 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 PM CST WED NOV 29 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER OH VALLEY EWD THROUGH THE MIDDLE ATLANTIC STATES AND NEW ENGLAND... ...SYNOPSIS... INTENSE...NEGATIVELY-TILTED SHORT WAVE TROUGH INITIALLY OVER THE LOWER OH VALLEY WILL RAPIDLY TRANSLATE NEWD THROUGH THE ST. LAWRENCE VALLEY WITH 250-300M HEIGHT FALLS SPREADING NEWD THROUGH THE MIDDLE/UPPER OH VALLEY AND NERN STATES. IN THE LOW-LEVELS... DEEPENING SURFACE LOW WILL DEVELOP FROM THE MIDDLE OH VALLEY NEWD THROUGH THE UPPER GREAT LAKES INTO THE GULF OF ST. LAWRENCE WITH TRAILING COLD FRONT SWEEPING EWD THROUGH THE APPALACHIANS...PIEDMONT AND COASTAL PLAIN. ...UPPER OH VALLEY EWD THROUGH THE MIDDLE ATLANTIC STATES AND NEW ENGLAND... LARGE-SCALE PATTERN APPEARS SUPPORTIVE OF A LOW INSTABILITY/HIGH SHEAR SERIAL-TYPE DERECHO EVENT OVER PARTS OF THE REGION FRIDAY INTO FRIDAY NIGHT. STRONGLY FORCED...LOW-TOPPED CONVECTIVE LINE IS EXPECTED TO BE ONGOING FRIDAY MORNING FROM VICINITY OF SURFACE LOW OVER IND/WRN OH SWD ALONG COLD FRONT INTO MIDDLE TN...DRIVEN BY INTENSE LARGE-SCALE FORCING ASSOCIATED WITH EJECTING UPPER WAVE. SSWLY 50-60KT LLJ INITIALLY FROM AL/GA INTO THE UPPER OH VALLEY WILL SHIFT EWD THROUGH THE DAY...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD INTO THE REGION. THIS INCREASE IN MOISTURE COUPLED WITH STEEPENING MID-LEVEL LAPSE RATES ARE EXPECTED TO CONTRIBUTE TO DESTABILIZATION OF PRE-FRONTAL AIR MASS WITH STRONGEST INSTABILITY /MUCAPES APPROACHING 500-900 J PER KG/ DEVELOPING ACROSS PA AND NY FRIDAY AFTERNOON. 100-120KT MID-LEVEL JET STREAK ALONG IMMEDIATE DOWNSTREAM POSITION OF TROUGH BASE AND 60-70KT WINDS AS LOW AS 1-2 KM AGL /PER FORECAST SOUNDINGS/ INDICATE THAT EVEN WEAK CONVECTIVE DOWNDRAFTS WILL BE CAPABLE OF DAMAGING WINDS. AS SUCH...EXPECT THAT THE WIND DAMAGING THREAT WILL EXIST FROM THE ONSET OF THE FORECAST OVER OH SWD INTO KY/WV...WITH THIS THREAT LIKELY INCREASING CONSIDERABLY BY AFTERNOON OVER NY/PA AS CONVECTIVE LINE ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS. EMBEDDED BOWING/LEWP STRUCTURES WILL BE CAPABLE OF CORRIDORS OF DAMAGING WINDS...ESPECIALLY GIVEN THE FORECAST 50-60+KT STORM MOTIONS. THE STRONGER INSTABILITY OVER NY/PA MAY EVEN SUPPORT EMBEDDED SUPERCELLS WITH A THREAT OF ISOLATED TORNADOES GIVEN THE STRONG LOW-LEVEL SHEAR AND LOW LCL HEIGHTS. EXPECT THIS STRONGLY FORCED...FAST MOVING CONVECTIVE LINE TO SWEEP THROUGH THE HUDSON VALLEY AND DE RIVER VALLEY LATE FRIDAY AFTERNOON OR EARLY EVENING...AND MUCH OF NEW ENGLAND FRIDAY NIGHT. WIDESPREAD DAMAGING WINDS WILL REMAIN POSSIBLE THROUGH AT LEAST THE EVENING HOURS AS BOUNDARY LAYER REMAINS SOMEWHAT TURBULENTLY MIXED. SHOULD FUTURE OBSERVATIONS AND/OR MODEL GUIDANCE INDICATE MORE INSTABILITY THAN IS CURRENTLY FORECAST...AN UPGRADE TO MODERATE RISK MAY BECOME NECESSARY. ..MEAD.. 11/30/2006  From swody2 at goshenarc.org Thu Nov 30 17:25:55 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 30 Nov 2006 12:25:55 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301727 SWODY2 SPC AC 301725 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CST THU NOV 30 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH/TN VLYS NEWD INTO THE MID-ATLANTIC REGION AND NEW ENGLAND... ...OH VLY/CNTRL APPALACHIANS NEWD TO NEW ENGLAND/MID-ATLANTIC... SYNOPTIC REGIME APPEARS SUPPORTIVE OF A LOW INSTABILITY/HIGH SHEAR SERIAL-TYPE DERECHO EVENT ACROSS PARTS OF THE REGION FRI AND FRI NIGHT. POTENTIAL EXISTS FOR WIDESPREAD DAMAGING WINDS AND ISOLD TORNADOES...PARTICULARLY ACROSS CNTRL/ERN PA...PARTS OF MD AND SRN NY. POWERFUL NEGATIVE-TILT UPPER LOW AND ASSOCD 120+ KT H5 JET WILL TRANSLATE FROM THE LWR OH VLY EARLY FRI TO SRN QUE BY 12Z SAT. IMPRESSIVE LARGE SCALE HEIGHT FALLS OF 150-300 METERS WILL SPREAD NEWD...WITH THE STRONGEST FALLS SHIFTING THROUGH THE OH VLY INTO PA/NY DURING FRI AFTN/EVE. AT THE SFC...PRIMARY OCCLUSION WILL TRAVEL FROM NRN IND INTO SWRN ONTARIO BY FRI EVE. NEW CYCLOGENESIS IS LIKELY OVER NCNTRL PA OR SCNTRL NY FRI MORNING...WITH THE LOW THEN MOVING INTO NWRN MAINE/SRN QUE BY 12Z SATURDAY. A TRAILING COLD FRONT WILL SWEEP EWD ACROSS THE APPALACHIANS DURING FRI AFTN/EVE...THEN OFFSHORE BY EARLY SATURDAY MORNING. A STRONGLY FORCED...LOW-TOPPED CONVECTIVE LINE IS EXPECTED TO BE ONGOING EARLY FRI MORNING FROM THE OCCLUDED LOW OVER IND SWD INTO THE MID-TN VLY. AHEAD OF THIS LINE...A STRONG SSWLY LLJ IN EXCESS OF 50-60 KTS WILL SHIFT EWD FROM THE OH/TN VLYS. AS A RESULT...SUBSTANTIAL BOUNDARY LAYER MOISTURE...NOW EVIDENT AS SFC DEW POINTS AOA 60 DEG F OVER THE SERN STATES...WILL ADVECT NWD. GIVEN STEEPENING MID-LEVEL LAPSE RATES SPREADING EWD ATOP THIS MOIST AXIS...MODEST DESTABILIZATION IS EXPECTED AHEAD OF THE FRONT. STRONGEST INSTABILITY /MUCAPES OF A FEW HUNDRED J/KG/ SHOULD DEVELOP ACROSS PARTS OF PA AND NY DURING PEAK HEATING FRI. AS A RESULT...TSTMS WILL LIKELY INTENSIFY OVER THESE AREAS AFTER 18Z. FORECAST SOUNDINGS INDICATE THAT TSTMS WILL LIKELY BECOME SFC-BASED...ESPECIALLY ALONG AND IMMEDIATELY EAST OF THE SPINE OF THE APPALACHIANS AND THEN RAPIDLY TRANSLATE ENEWD INTO SCNTRL NY/ERN PA/NRN MD BY FRI EVE. AMBIENT WINDS WILL BE QUITE STRONG WITH THIS SYSTEM WITH 70 KTS JUST OFF THE SURFACE...INCREASING CONFIDENCE THAT CONVECTIVE DOWNDRAFTS WILL BE CAPABLE OF DAMAGING WINDS. WHILE THE WIND DAMAGE THREAT WILL EXIST FROM THE ONSET OF THE FCST PERIOD OVER THE MID-OH VLY SWD INTO ERN PORTIONS OF KY/TN...THE THREAT WILL INCREASE AND PEAK BY AFTN OVER NY/PA AND NRN MD AS THE LINE ENCOUNTERS THE MORE SUBSTANTIAL INSTABILITY/LOW-LEVEL LAPSE RATES. EMBEDDED BOWING/LEWP STRUCTURES WILL BE CAPABLE OF CORRIDORS OF DAMAGING WINDS...ESPECIALLY GIVEN THE FORECAST 50-60+KT STORM MOTIONS. MOREOVER...THE STRONGER INSTABILITY OVER NY/PA MAY EVEN SUPPORT SUPERCELLS...BOTH EMBEDDED WITHIN THE LINE AND POSSIBLY IN THE WARM SECTOR...WITH A THREAT OF ISOLATED TORNADOES GIVEN THE STRONG LOW-LEVEL SHEAR AND LOW LCL HEIGHTS. THIS STRONGLY FORCED...FAST MOVING CONVECTIVE LINE WILL SWEEP THROUGH THE HUDSON VALLEY AND DE RIVER VLY LATE FRI AFTN/EVE AND MUCH OF NEW ENGLAND FRI NIGHT WITH ATTENDANT DAMAGING WINDS. NRN EXTENT OF THE DAMAGING WIND THREAT SHOULD BE MODULATED BY AN E-W FRONT THAT SHOULD REMAIN ACROSS AT LEAST SRN MAINE OVERNIGHT. ..RACY.. 11/30/2006  From swody2 at goshenarc.org Sat Nov 4 05:55:32 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Nov 2006 00:55:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040558 SWODY2 SPC AC 040557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST FRI NOV 03 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN IS FORECAST TO REMAIN QUASI-ZONAL THROUGH MUCH OF SUNDAY. HOWEVER SOME AMPLIFICATION OF THE PATTERN IS EXPECTED LATE THIS PERIOD. MAIN FEATURE OF INTEREST WILL BE A FULL LATITUDE UPPER TROUGH THAT IS FORECAST TO BEGIN AMPLIFYING OVER THE PLAINS SUNDAY NIGHT. A SHORTWAVE TROUGH EMBEDDED WITHIN THE SRN BRANCH OF THIS FEATURE WILL MOVE INTO THE SRN PLAINS. ...SWRN THROUGH W CNTRL TX... MODIFIED CP AIR WITH UPPER 50S TO LOW 60S DEWPOINTS WILL BEGIN ADVECTING NWWD THROUGH TX SUNDAY AS BOUNDARY LAYER FLOW OVER THE WRN GULF BECOMES SELY IN WAKE OF RETREATING SERN U.S. SURFACE RIDGE. SUFFICIENT LOW LEVEL MOISTURE SHOULD ADVECT FAR ENOUGH WWD BENEATH 6.5-7 C/KM MID LEVEL LAPSE RATES EXPECTED ACROSS W TX TO RESULT IN MLCAPE NEAR 1000 J/KG BY LATE AFTERNOON. ELEVATED STORMS WILL LIKELY BE IN PROGRESS EARLY SUNDAY FARTHER N FROM NRN TX INTO OK WITHIN THE LOW LEVEL WARM ADVECTION REGIME. FARTHER S ACROSS PARTS OF WRN AND SWRN TX...SOME HEATING MAY OCCUR DURING THE AFTERNOON. STORMS MAY DEVELOP IN THIS AREA AS THE CAP WEAKENS AND THE ATMOSPHERE DESTABILIZES. INITIAL ACTIVITY COULD INITIATE OVER THE HIGHER TERRAIN OF SWRN TX. FORCING FOR ASCENT ATTENDING SEWD ADVANCING UPPER TROUGH AND INCREASING SLY LOW LEVEL JET SHOULD RESULT IN AN ENVIRONMENT FAVORABLE FOR OTHER STORMS TO DEVELOP OVER W THROUGH W CNTRL TX DURING THE EVENING. THE THERMODYNAMIC ENVIRONMENT AND EFFECTIVE SHEAR ON THE ORDER OF 35 TO 40 KT APPEAR SUFFICIENT FOR SOME UPDRAFTS TO ROTATE. ISOLATED HAIL AND STRONG WIND GUSTS SHOULD BE THE MAIN THREATS. STORMS MAY EVOLVE INTO ONE OR MORE CLUSTERS AS THEY CONTINUE EAST OVERNIGHT. ..DIAL.. 11/04/2006  From swody2 at goshenarc.org Sat Nov 4 16:31:11 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 04 Nov 2006 11:31:11 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041633 SWODY2 SPC AC 041632 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1032 AM CST SAT NOV 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SPLIT FLOW REGIME WILL UNDERGO AMPLIFICATION DURING THE DAY TWO PERIOD AS FULL-LATITUDE TROUGH EVOLVES OVER THE CNTRL CONUS. WITHIN THIS LARGER-SCALE PATTERN...SHORT WAVE TROUGH CURRENTLY APPROACHING THE FOUR-CORNERS REGION WILL SEWD INTO THE SRN PLAINS SUNDAY/SUNDAY NIGHT WITH AN ASSOCIATED BELT OF MODEST /40-45 KTS AT 500 MB/ SPREADING ACROSS NRN TX/SRN OK. IN THE LOW-LEVELS...INVERTED TROUGH FROM NRN MEXICO INTO THE SRN HIGH PLAINS WILL GRADUALLY SHIFT EWD THROUGH THE PERIOD. ...TX... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING SUNDAY MORNING FROM PORTIONS OF THE TX PNHDL EWD THROUGH OK/RED RIVER VALLEY INTO THE WRN OZARK PLATEAU WITHIN LOW-LEVEL WAA REGIME ASSOCIATED WITH AMPLIFYING SRN STREAM TROUGH. TO THE S OF THIS AREA...INCREASING SLY/SELY LOW-LEVEL FLOW WILL ALLOW FOR THE NWD/NWWD ADVECTION OF MODIFIED CP AIR MASS BENEATH MODEST MID LEVEL LAPSE RATES /7 C PER KM/ CONTRIBUTING POCKETS OF MODERATE INSTABILITY E OF INVERTED TROUGH WITH MLCAPES INCREASING TO AROUND 1000 J/KG. WHILE SOME THREAT OF DIURNAL STORMS WILL EXIST DURING THE AFTERNOON FROM N TX INTO THE EDWARDS PLATEAU/CONCHO VALLEY...IT APPEARS THE BETTER POTENTIAL WILL BE SUNDAY NIGHT AS LLJ RE-INTENSIFIES OVER THE LOWER RIO GRANDE VALLEY AND EFFECTIVELY ENHANCES CONVERGENCE ALONG LOW-LEVEL BAROCLINIC ZONE. 30-35 KT OF EFFECTIVE BULK SHEAR COUPLED WITH THE MODEST INSTABILITY INDICATES SOME POTENTIAL FOR ORGANIZED/ROTATING STORMS WITH THE MAIN THREATS BEING ISOLATED...SEVERE HAIL AND PERHAPS LOCALLY DAMAGING WINDS. ..MEAD.. 11/04/2006  From swody2 at goshenarc.org Sun Nov 5 05:15:12 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 05 Nov 2006 00:15:12 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050517 SWODY2 SPC AC 050515 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 PM CST SAT NOV 04 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE GFS...NAM AND ECMWF HAVE COME INTO BETTER AGREEMENT IN HANDLING SRN BRANCH OF FULL LATITUDE UPPER TROUGH THAT WILL CONTINUE THROUGH THE SRN PLAINS AND LOWER MS VALLEY MONDAY. THE GFS HAS BACKED AWAY FROM CLOSING THE SRN BRANCH SHORTWAVE TROUGH OFF OVER THE WRN GULF. ALL MODELS NOW MAINTAIN A PROGRESSIVE OPEN TROUGH. ...SRN AND SERN TX THROUGH THE LOWER MS VALLEY... LITTLE IN THE WAY OF CYCLOGENESIS IS FORECAST AS THE POSITIVELY TILTED SHORTWAVE TROUGH MOVES THROUGH THE SRN PLAINS AND LOWER MS VALLEY. RESULTING MODEST LOW LEVEL WIND FIELDS WILL LIMIT NWD EXTENT AND DEGREE OF MOISTURE RETURN. HOWEVER...DEWPOINTS IN THE MID TO UPPER 60S WILL LIKELY HAVE ADVECTED INTO SRN AND SERN TX BY EARLY MONDAY. RICHER LOW LEVEL MOISTURE MAY ALSO SPREAD INTO SRN LA AS A COASTAL BOUNDARY MOVES INLAND. STORMS WILL LIKELY BE ONGOING EARLY MONDAY WITHIN ZONE OF ASCENT IN ADVANCE OF THE SHORTWAVE TROUGH FROM PARTS OF CNTRL AND ERN TX NEWD INTO THE LOWER MS VALLEY. EARLY ONSET OF CONVECTION OVER MUCH OF WARM SECTOR AND WEAK LAPSE RATES SUGGEST INSTABILITY WILL REMAIN LIMITED. BEST CHANCE FOR DESTABILIZATION WILL BE ACROSS PARTS OF S TX WHERE MORE SURFACE HEATING MAY OCCUR. MODEST MID LEVEL FLOW OF 25 TO 30 KT ACCOMPANYING THE UPPER TROUGH AND LACK OF A STRONG LOW LEVEL JET SUGGEST VERTICAL SHEAR PROFILES WILL REMAIN ONLY MARGINALLY SUFFICIENT FOR ORGANIZED STORMS. SOME POTENTIAL FOR INTENSIFICATION MAY EXIST AS STORMS DEVELOP SEWD DURING THE DAY...MAINLY OVER PARTS OF S TX WHERE MORE INSTABILITY IS EXPECTED. ACTIVITY SHOULD REMAIN MAINLY MULTICELL IN CHARACTER WITH A MARGINAL THREAT OF ISOLATED WIND GUSTS AND SMALL HAIL. ..DIAL.. 11/05/2006  From swody2 at goshenarc.org Sun Nov 5 16:25:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 05 Nov 2006 11:25:56 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051628 SWODY2 SPC AC 051627 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN NOV 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DESPITE SOME DIFFERENCES....LATEST MODEL GUIDANCE SUGGESTS THAT SRN STREAM BRANCH OF FULL LATITUDE TROUGH WILL INTENSIFY AS IT TRANSLATES FROM THE SRN PLAINS EWD INTO THE LOWER MS VALLEY. IN THE LOW-LEVELS...ATTENDANT SURFACE LOW WILL DEVELOP EWD FROM THE TX HILL COUNTY INTO CNTRL MS BY TUESDAY MORNING WITH TRAILING COLD FRONT PUSHING SEWD INTO THE NWRN GULF OF MEXICO. MEANWHILE...WARM FRONT ATTENDANT TO THIS MIGRATORY SURFACE LOW WILL RETREAT NWD THROUGH THE CNTRL GULF COAST. ...TX COAST EWD ACROSS SRN LA/MS... A FAIRLY LARGE SHIELD OF SHOWERS AND TSTMS ARE EXPECTED TO BE ONGOING MONDAY MORNING AHEAD OF AMPLIFYING UPPER WAVE OVER SRN AND ERN PORTIONS OF TX INTO WRN LA WITHIN A RELATIVELY MOIST LOW-LEVEL AIR MASS CHARACTERIZED BY DEWPOINTS IN THE 60S. WEAK LAPSE RATES RESULTING FROM THE WIDESPREAD CLOUDS AND PRECIPITATION WILL LIMIT AIR MASS DESTABILIZATION WITH MLCAPES AOB 500-800 J/KG. ADDITIONALLY...WIND FIELDS ARE NOT FORECAST TO BE PARTICULARLY STRONG WITH GENERALLY 30-40 KT MID-LEVEL FLOW ACROSS SYSTEM WARM SECTOR. HOWEVER...MODEST LOW-LEVEL WAA AND RESULTANT LOW-LEVEL HODOGRAPH CURVATURE INDICATE SOME POTENTIAL FOR EMBEDDED ROTATING STORMS CAPABLE OF LOCALLY STRONG WIND GUSTS AND PERHAPS A BRIEF TORNADO OR TWO. THIS MARGINAL SEVERE STORM THREAT IS FORECAST TO SPREAD FROM THE TX COAST/SWRN LA MONDAY INTO SERN LA AND FAR SRN MS MONDAY NIGHT. ..MEAD.. 11/05/2006  From swody2 at goshenarc.org Mon Nov 6 06:01:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Nov 2006 01:01:49 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060603 SWODY2 SPC AC 060602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1202 AM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MODELS ARE IN GENERAL AGREEMENT AMPLIFYING A SHORTWAVE TROUGH INTO A CLOSED UPPER LOW OVER THE LOWER MS VALLEY BY EARLY TUESDAY. THIS FEATURE IS FORECAST TO OCCLUDE AND CONTINUE SLOWLY EAST THROUGH THE SERN U.S. DURING THE DAY. ATTENDANT CYCLOGENESIS IS NOT EXPECTED TO BE PARTICULARLY STRONG. BY EARLY TUESDAY AN OCCLUDED FRONT SHOULD EXTEND FROM A WEAK SURFACE LOW OVER THE LOWER MS VALLEY SWWD INTO THE NWRN GULF. A WARM FRONT SHOULD EXIST JUST OFFSHORE OVER THE NERN GULF INTO NRN FL AND MAY LIFT SLOWLY NWD DURING THE DAY. ...CNTRL AND SRN AL...SRN GA THROUGH FL... CONVECTION WILL LIKELY SPREAD NEWD THROUGH THE NERN GULF COASTAL AREA WITHIN WARM ADVECTION ZONE EARLY TUESDAY. ACTIVITY MAY BE MORE WIDESPREAD N OF WARM FRONT FROM PARTS OF THE FL PANHANDLE INTO SERN AL AND SRN GA. BOUNDARY LAYER DEWPOINTS IN THE UPPER 60S TO NEAR 70 SHOULD RESIDE S OF THE WARM FRONT. LOW LEVEL HODOGRAPHS IN VICINITY OF AND JUST N OF THIS BOUNDARY WILL BE FAVORABLE FOR UPDRAFT ROTATION AND LOW LEVEL MESOCYCLONES. HOWEVER...WIDESPREAD CLOUDS AND RAIN WILL LIKELY LIMIT SIGNIFICANT DESTABILIZATION POTENTIAL. BEST CHANCE FOR DESTABILIZATION WILL EXIST S OF THE BOUNDARY WHERE SOME CLOUD BREAKS WILL BE POSSIBLE...BUT WEAKER LOW LEVEL SHEAR PROFILES WILL EXIST IN THIS AREA. OTHER STORMS MAY DEVELOP IN PRE-FRONTAL WARM SECTOR S OF THE WARM FRONT OVER THE NERN GULF AND SPREAD EWD INTO FL BY LATE AFTERNOON AND OVERNIGHT. LARGELY UNIDIRECTIONAL WIND PROFILES WITH SWLY DEEP LAYER SHEAR ON THE ORDER OF 35 TO 40 KT WILL BE SUFFICIENT FOR SOME ORGANIZED STRUCTURES WITHIN THE LINE. FARTHER W NEAR OCCLUDED FRONT ACROSS PARTS OF AL...SOME POTENTIAL FOR DESTABILIZATION WILL EXIST AS UPPER DRY SLOT ADVANCES EWD. HOWEVER...LOW CLOUDS COULD BE SLOW TO MIX OUT AND LIMIT INSTABILITY IN THIS REGION AS WELL WITH MLCAPE GENERALLY AOB 500 J/KG EXPECTED. STILL PROXIMITY TO STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE UPPER LOW SUGGEST STORMS COULD INTENSIFY ALONG THE FRONT AND BECOME CAPABLE OF PRODUCING PRIMARILY ISOLATED DAMAGING WIND GUSTS. WILL INTRODUCE 5% SEVERE PROBABILITIES AND NOT UPGRADE TO SLIGHT RISK AT THIS TIME DUE PRIMARILY TO POTENTIAL LIMITING FACTORS UPON THE THERMODYNAMIC ENVIRONMENT. HOWEVER...AN UPGRADE TO SLIGHT RISK MAY BE NEEDED FOR PORTIONS OF THESE AREAS IN LATER OUTLOOKS. ...MS... COLD CORE UPPER LOW WITH -18C AT 500 MB IS FORECAST TO MOVE OVER THE LOWER MS VALLEY DURING THE AFTERNOON. SOME POTENTIAL WILL EXIST FOR STORMS TO DEVELOP IN THIS REGION IN ASSOCIATION WITH VORT MAX. ISOLATED SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...ESPECIALLY IF LOW CLOUDS MIX OUT ALLOWING BOUNDARY LAYER WARMING TO OCCUR. ..DIAL.. 11/06/2006  From swody2 at goshenarc.org Mon Nov 6 17:22:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 06 Nov 2006 12:22:24 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061724 SWODY2 SPC AC 061722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... STRONG HEIGHT FALLS WILL SPREAD EWD ALONG THE CNTRL GULF COAST REGION TUESDAY AS UPPER SPEED MAX TRANSLATES TOWARD THE FL PANHANDLE/SRN AL EARLY IN THE PERIOD. STRONG ASCENT WITHIN A RECOVERING WARM ADVECTION REGIME WILL UNDOUBTEDLY ENHANCE THE CONVECTIVE THREAT AHEAD OF COLD FRONT...AND ATOP COOLER RETREATING BOUNDARY LAYER. RELUCTANCE FOR AIRMASS RECOVERY WILL BE THE MAIN IMPEDIMENT FOR SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE CNTRL/ERN GULF COAST...AND FL PENINSULA AS DEEP LAYER SHEAR WILL PROVE MORE THAN ADEQUATE FOR SUSTAINING DEEP ROTATING UPDRAFTS. AT THIS TIME IT APPEARS WIDESPREAD SHOWERS/THUNDERSTORMS WILL EVOLVE WITHIN WEAK LAPSE RATE/WARM CONVEYOR BELT...A CONTINUATION OF DAY1 ACTIVITY. THIS ACTIVITY SHOULD PROGRESS STEADILY TOWARD THE ATLANTIC COAST WHERE INCREASING LLJ OFFSHORE MAY ALLOW SOMEWHAT MORE BUOYANT AIR TO SPREAD JUST INLAND ALONG THE SC/NC COAST LATE IN THE PERIOD. GIVEN THE EXPECTED CLOUDS/PRECIPITATION...AND LACK OF INSTABILITY...IT APPEARS GREATEST SEVERE POTENTIAL WILL BE LIMITED TO SUPERCELL STRUCTURES NEAR THE COAST/OR MAINLY OFFSHORE...AND THIS ACTIVITY SHOULD PROVE ISOLATED. ...ELSEWHERE... DEEP CONVECTION MAY DEVELOP WITHIN STRONG BAROCLINIC ZONE ACROSS PORTIONS OF THE NRN ROCKIES DURING THE LATTER HALF OF THE PERIOD...MAINLY ACROSS THE HIGHER ELEVATIONS OF ID/WRN MT. ISOLATED THUNDERSTORMS COULD EVOLVE WITHIN THIS FRONTAL BAND AS IT SAGS SEWD TOWARD THE SNAKE RIVER VALLEY. ..DARROW.. 11/06/2006  From swody2 at goshenarc.org Tue Nov 7 05:32:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Nov 2006 00:32:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070534 SWODY2 SPC AC 070532 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 PM CST MON NOV 06 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SERN U.S. UPPER LOW WILL CONTINUE EAST AND OFF THE ATLANTIC SEABOARD BY WEDNESDAY NIGHT. BY 12Z WEDNESDAY...ATTENDANT FRONT WILL EXTEND FROM A SURFACE LOW IN EXTREME ERN NC SWWD ALONG THE GULF STREAM AND INTO SRN FL. REMAINING PORTIONS OF FRONT WILL MOVE OFFSHORE DURING MORNING. WIDESPREAD CONVECTION WILL BE ONGOING WITHIN THE ZONE OF ASCENT ALONG AND JUST E OF THIS BOUNDARY. STRONG LOW TO MID LEVEL VERTICAL WIND PROFILES WILL EXIST WITHIN THE PRE-FRONTAL WARM SECTOR. HOWEVER...LIMITED POTENTIAL FOR DESTABILIZATION WILL EXIST BEFORE ACTIVITY MOVES OFFSHORE. OTHER CONVECTION MAY DEVELOP DURING THE DAY FARTHER W NEAR VORT MAX WHERE STEEPER LAPSE RATES AND COLD MID LEVEL TEMPERATURES WILL EXIST. ANOTHER IN A SERIES OF SHORTWAVE TROUGHS WILL MOVE ONTO THE PACIFIC NW ACCOMPANIED BY SCATTERED CONVECTION. STEEP 700-500 MB LAPSE RATES AND COLD MID LEVEL TEMPERATURES ACCOMPANYING THIS FEATURE MIGHT RESULT IN SUFFICIENT INSTABILITY FOR ISOLATED LIGHTING STRIKES...ESPECIALLY NEAR THE COAST. ..DIAL.. 11/07/2006  From swody2 at goshenarc.org Tue Nov 7 17:26:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 07 Nov 2006 12:26:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071728 SWODY2 SPC AC 071727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST TUE NOV 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...MIDDLE ATLANTIC... UPPER LEVEL SPEED MAX WILL SHIFT OFF THE CAROLINA COAST EARLY IN THE PERIOD AS UPPER LOW SETTLES INTO NERN GA. MAIN BAROCLINIC ZONE AND ASSOCIATED CONVECTIVE THREAT SHOULD BE WELL EAST OF THE OUTER BANKS REGION OF NC AT 12Z...TRAILING SWWD INTO THE SRN TIP OF THE FL PENINSULA. HOWEVER...COLD MID LEVEL TEMPERATURES AND A POCKET OF STEEP LAPSE RATES SHOULD ENHANCE THE CONVECTIVE THREAT BENEATH THE UPPER LOW AS IT MOVES ACROSS THE CAROLINAS DURING THE DAY. ADDITIONALLY...THERE APPEARS TO BE AT LEAST A MARGINAL THREAT FOR ISOLATED ELEVATED THUNDERSTORMS WITHIN THE WARM ADVECTION ZONE JUST NORTH OF THE SFC LOW WHERE BOUNDARY LAYER AIRMASS SHOULD PROVE COOL/STABLE. REGARDLESS...ACTIVITY SHOULD PROVE ISOLATED AND WEAK ACROSS THE ENTIRE REGION. ...PACIFIC NW... BUOYANT MARITIME AIRMASS WILL BEGIN SPREADING INLAND AS SFC FRONT PROGRESSES ACROSS WRN WA/ORE EARLY IN THE PERIOD. LOW TOPPED CONVECTION AND ISOLATED THUNDERSTORMS SHOULD BE NOTED WITH UPPER TROUGH AS IT APPROACHES THE COAST. AT THIS TIME IT APPEARS DAYTIME HEATING WILL ENHANCE THE POTENTIAL FOR ISOLATED LIGHTNING WITHIN DEEPER SHOWERS...MAINLY DURING THE AFTERNOON/EVENING HOURS...AND MAINLY CONFINED NEAR THE COAST. ..DARROW.. 11/07/2006  From swody2 at goshenarc.org Wed Nov 8 05:39:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Nov 2006 00:39:40 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080541 SWODY2 SPC AC 080539 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1139 PM CST TUE NOV 07 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORTWAVE TROUGH OVER THE ERN PACIFIC WILL MOVE INTO THE PLAINS BY LATE THURSDAY. A LEE CYCLONE WILL DEVELOP OVER THE SRN HIGH PLAINS IN ADVANCE OF THIS FEATURE THEN SHIFT NEWD THROUGH OK/KS AND INTO THE MID MS VALLEY OVERNIGHT. AS THE LOW SHIFTS EAST THE DRYLINE WILL SHARPEN ACROSS TX AND OK. COLD FRONT MARKING LEADING EDGE OF CP AIR WILL MOVE SWD THROUGH THE CNTRL PLAINS THURSDAY...THEN ACCELERATE INTO THE SRN PLAINS OVERNIGHT AS THE LOW LIFTS NEWD INTO THE MID MS VALLEY. ...N CNTRL/NERN OK...ERN KS THROUGH SWRN AND CNTRL MO... MODIFIED CP AIR WILL ADVECT NWD THROUGH THE SRN PLAINS AND LOWER MS VALLEY THURSDAY AS SSWLY BOUNDARY LAYER FLOW INCREASES DOWNSTREAM FROM DEVELOPING CYCLONE. HOWEVER SWLY FLOW IN THE 850-700 MB LAYER WILL LIKELY ADVECT AN EML PLUME THROUGH THE SRN PLAINS AND INTO THE LOWER MS VALLEY ABOVE THE MOISTENING BOUNDARY LAYER. THESE PROCESSES WILL CONTRIBUTE TO DESTABILIZATION DURING THE DAY. HOWEVER...THE EML WILL LIKELY CAP THE WARM SECTOR. A FEW STORMS COULD DEVELOP THURSDAY NIGHT FROM PARTS OF NERN OK...ERN KS THROUGH MO WITHIN ZONE OF LIFT ASSOCIATED WITH THE SWD ADVANCING FRONT AND SWLY LOW LEVEL JET. MOST ACTIVITY WILL PROBABLY BE ELEVATED ON COOL SIDE OF FRONT GIVEN THE ANTICIPATED AMOUNT OF LIFT NEEDED TO OVERCOME CAP. LAPSE RATES OF 7-7.5 C/KM IN THE 700-500 MB LAYER SUGGEST THE STRONGER STORMS COULD PRODUCE SMALL HAIL...BUT INSTABILITY WILL PROBABLY BE TOO MARGINAL FOR A MORE ROBUST THREAT. ..DIAL.. 11/08/2006  From swody2 at goshenarc.org Wed Nov 8 17:19:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 08 Nov 2006 12:19:31 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081721 SWODY2 SPC AC 081719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CST WED NOV 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT SHORT WAVE IMPULSES...EMBEDDED WITHIN SPLIT BELTS OF POLAR WESTERLIES...WILL REMAIN PROGRESSIVE ACROSS CANADA AND THE U.S. THROUGH THIS FORECAST PERIOD. IN THE WAKE OF THE CLOSED LOW...PROGGED TO BE LIFTING AWAY FROM THE SOUTH ATLANTIC COAST BY 12Z THURSDAY...THE SOUTHERN AND SUBTROPICAL STREAMS WILL BE OUT OF PHASE THROUGH MUCH OF THE REMAINDER OF THIS PERIOD ...WITH THE WEAK SUBTROPICAL STREAM GENERALLY SOUTH OF THE U.S. BORDER. THE NEXT SIGNIFICANT SHORT WAVE TROUGH DIGGING INTO THE SOUTHERN STREAM IS ALREADY ADVANCING INTO NORTH CENTRAL PACIFIC COASTAL AREAS...AND PROGGED TO CONTINUE INTO THE NORTHERN GREAT BASIN BY 12Z THURSDAY...THEN ACROSS THE NORTH CENTRAL ROCKIES INTO THE NORTHERN/CENTRAL PLAINS BY 12Z FRIDAY. MODELS SUGGEST THIS FEATURE WILL CONTRIBUTE TO WEAK SURFACE CYCLOGENESIS TO THE LEE OF THE SOUTH CENTRAL ROCKIES. THIS WILL OCCUR NEAR/SOUTH OF A COLD FRONT SURGING SOUTHWARD THROUGH THE PLAINS...IN THE WAKE OF A NORTHERN STREAM IMPULSE WHICH IS PROGGED TO SHIFT EAST OF THE UPPER GREAT LAKES REGION ON THURSDAY. ...GREAT BASIN THRU THE CNTRL/SRN PLAINS AND MS VALLEY... COLD AIR ALOFT ASSOCIATED WITH THE SHORT WAVE TROUGH EMANATING FROM THE PACIFIC WILL CONTRIBUTE TO WEAK DESTABILIZATION ACROSS THE EASTERN GREAT BASIN AND NORTH CENTRAL ROCKIES BY THURSDAY AFTERNOON. THIS WILL PROBABLY BE ACCOMPANIED BY WEAK CONVECTIVE DEVELOPMENT...PARTICULARLY ACROSS THE HIGHER TERRAIN...WHERE SOME POTENTIAL WILL EXIST FOR A THUNDERSTORM. HOWEVER...AREAL COVERAGE/PROBABILITY OF OCCURRENCE APPEARS LOW. OTHERWISE...CONVECTIVE POTENTIAL IS EXPECTED TO REMAIN LIMITED THURSDAY/THURSDAY NIGHT ACROSS MUCH OF THE CENTRAL STATES... DESPITE THE LIKELIHOOD OF AT LEAST A WEAK RETURN FLOW OF MOISTURE FROM THE WESTERN GULF OF MEXICO. MOISTURE SUFFICIENT FOR VIGOROUS CONVECTIVE DEVELOPMENT IS ALREADY PRESENT ACROSS WESTERN GULF COASTAL AREAS...AND WILL PROBABLY ADVECT THROUGH MUCH OF THE SOUTHERN PLAINS AND LOWER HALF OF THE MISSISSIPPI VALLEY THURSDAY. HOWEVER...THIS WILL OCCUR BENEATH A RATHER WARM AND DRY MID-LEVEL ENVIRONMENT...WHICH MODEL FORECAST SOUNDINGS SUGGEST WILL SUPPRESS DEEP CONVECTION. AN EXCEPTION TO THIS MAY BE ON THE LEADING EDGE OF THE BETTER MOISTURE RETURN...AS IT ENCOUNTERS A STRENGTHENING LOW/MID-LEVEL FRONTAL ZONE ACROSS PARTS OF NORTHEAST KANSAS/NORTHERN MISSOURI/SOUTHERN IOWA...TOWARD 12Z FRIDAY. ..KERR.. 11/08/2006  From swody2 at goshenarc.org Thu Nov 9 06:07:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 09 Nov 2006 01:07:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090609 SWODY2 SPC AC 090607 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1207 AM CST THU NOV 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN TX THROUGH THE LOWER MS VALLEY AND WRN TN VALLEY... ...SYNOPSIS... UPPER TROUGH OVER THE W COAST WILL MOVE EAST INTO THE PLAINS FRIDAY. INCREASING WLY UPPER FLOW AND HEIGHT FALLS DOWNSTREAM FROM THIS FEATURE WILL CONTRIBUTE TO LEE CYCLOGENESIS OVER THE HIGH PLAINS THURSDAY. AS UPPER TROUGH MOVES THROUGH THE PLAINS...THE LOW WILL SHIFT RAPIDLY NEWD THROUGH OK INTO THE MID MS VALLEY REACHING THE OH VALLEY FRIDAY NIGHT. BY 12Z FRIDAY A FRONT WILL EXTEND FROM THE OH VALLEY SWWD THROUGH OK AND NWRN TX. A DRYLINE WILL EXTEND FROM THE LOW IN OK SWD THROUGH CNTRL TX. AS THE LOW LIFTS NE DURING THE DAY...THE FRONT WILL SURGE SE THROUGH THE SRN PLAINS AND MID TO LOWER MS VALLEYS DURING THE DAY...REACHING THE OH AND TN VALLEYS OVERNIGHT. ...ERN TX THROUGH THE LOWER MS VALLEY AND WRN TN VALLEY REGION... SWLY LOW LEVEL JET WILL DEVELOP OVER THE SRN PLAINS E OF SURFACE LOW AND ADVECT PARTIALLY MODIFIED GULF AIR NWD THROUGH THE PRE-FRONTAL WARM SECTOR. LOW LEVEL DEWPOINTS IN THE MID TO UPPER 60S ARE EXPECTED OVER THE SRN PLAINS AND LOWER MS VALLEY WITH LOWER 60S POSSIBLE INTO SRN MO. THE MOIST AXIS WILL SHIFT EAST AS THE LOW LEVEL JET VEERS DURING THE DAY. OBSERVED SOUNDINGS FROM WEDNESDAY EVENING SHOW AN EML HAS ADVECTED INTO W TX. THIS WARM LAYER WILL SPREAD EAST ABOVE MOIST AXIS THROUGH EARLY FRIDAY. WHILE THIS WILL SERVE TO DESTABILIZE THE ATMOSPHERE...MUCH OF THE WARM SECTOR OVER THE SRN PLAINS AND LOWER MS VALLEY WILL LIKELY REMAIN CAPPED TO SURFACE BASED STORMS MUCH OF THE DAY. MUCAPE WILL LIKELY RANGE FROM AROUND 1500 TO 2000 J/KG OVER THE SRN PLAINS AND LOWER MS VALLEY TO BELOW 800 J/KG FARTHER NE ACROSS THE MID MS VALLEY INTO THE OH VALLEY. ELEVATED STORMS WILL LIKELY BE ONGOING OVER PARTS OF NERN KS INTO NRN MO EARLY FRIDAY ALONG NERN EDGE OF THE STRONGER CAP AND WITHIN ZONE OF ASCENT N OF FRONTAL BOUNDARY. STORMS SHOULD CONTINUE EAST THROUGH THE MID MS VALLEY DURING THE DAY WITHIN ZONE OF STRONGEST FORCING FOR ASCENT ASSOCIATED WITH FRONT AND EWD ADVANCING SHORTWAVE TROUGH. FARTHER S OVER ERN TX AND THE LOWER MS VALLEY EXPECT INITIATION TO BE DELAYED UNTIL LATE AFTERNOON WHEN SEWD MOVING FRONT WILL INTERACT WITHIN MOISTENING AND DESTABILIZING BOUNDARY LAYER. GIVEN EXPECTED CAP...STORMS WILL LIKELY REMAIN CONFINED TO FRONTAL ZONE IN THIS REGION. SHEAR PROFILES WILL DECREASE WITH SWD EXTENT INTO THE LOWER MS VALLEY AND TX. HOWEVER...STORMS WILL LIKELY ORGANIZE INTO LINE SEGMENTS WITH ISOLATED DAMAGING WIND AND HAIL THE PRIMARY THREATS. SOME SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE MAINLY ACROSS PARTS OF AR WHERE BEST COMBINATION OF SHEAR AND INSTABILITY IS EXPECTED. ACTIVITY WILL SHIFT EAST INTO THE TN VALLEY OVERNIGHT. FARTHER N FROM SRN MO THROUGH WRN KY...INSTABILITY WILL BE MORE LIMITED BUT VERTICAL WIND PROFILES AND DEEP LAYER FORCING WILL BE STRONGER. PRIMARY THREAT WITH STORMS DEVELOPING ALONG THIS PORTION OF THE FRONT WILL BE ISOLATED DAMAGING WIND GUSTS...BUT POTENTIAL FOR A STABLE BOUNDARY LAYER COULD LIMIT OVERALL THREAT IN THIS REGION. ..DIAL.. 11/09/2006  From swody2 at goshenarc.org Sat Nov 11 05:56:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Nov 2006 00:56:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110558 SWODY2 SPC AC 110557 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST FRI NOV 10 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER LOW IS FORECAST OVER THE CAROLINAS AT THE START OF THE PERIOD...AND SHOULD CONTINUE EWD/ENEWD OFF THE MID-ATLANTIC COAST. ASSOCIATED SURFACE LOW -- THOUGH POSSIBLY INLAND AT THE START OF THE PERIOD -- SHOULD ALSO MOVE OFFSHORE THROUGH THE FIRST HALF OF THE PERIOD. SOME THUNDER THREAT MAY LINGER FROM THE COASTAL CAROLINAS NWD INTO SRN NEW ENGLAND INVOF UPPER LOW...BUT ANY SEVERE THREAT APPEARS MINIMAL AT BEST ATTM. MEANWHILE...LARGE/LOW-AMPLITUDE TROUGH IS FORECAST TO EXPAND EWD INTO THE CENTRAL CONUS...WITH MOST OF THE COUNTRY UNDER THE INFLUENCE OF CYCLONIC UPPER FLOW BY THE END OF THE PERIOD. THOUGH A LIGHTNING STRIKE OR TWO MAY OCCUR OVER MT AND VICINITY DURING THE AFTERNOON...THUNDER THREAT SHOULD REMAIN LIMITED AT BEST ACROSS THE WRN HALF OF THE CONUS. ..GOSS.. 11/11/2006  From swody2 at goshenarc.org Sat Nov 11 17:19:57 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 11 Nov 2006 12:19:57 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 111721 SWODY2 SPC AC 111720 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CST SAT NOV 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... CLOSED LOW EXPECTED TO DEVELOP OVER VA/CAROLINAS LATE DAY 1 WILL TRACK E OFF THE MID ATLANTIC COAST ON SUNDAY. MODELS DIVERGE WITH THE TRACK OF THIS SYSTEM AS IT MOVES OFFSHORE...WITH GREATER TRACK SPREAD SUGGESTED BEYOND DAY 2. MEANWHILE...BROAD CYCLONIC FLOW PATTERN SHOULD DEVELOP ACROSS MUCH OF THE CONUS BY 12Z MONDAY AS UPPER TROUGH NOW ENTERING WEST COAST SPREADS INLAND AND A SECOND TROUGH APPROACHES THE WEST COAST. SURFACE CYCLOGENESIS EXPECTED OVER VA TIDEWATER REGION LATE DAY 1 WILL ALSO MOVE OFFSHORE THIS FORECAST PERIOD. A BAND OR TWO OF CONVECTION/TSTMS MAY BE ONGOING ACROSS ERN NC AND THE ADJACENT COASTAL WATERS NWD TO VA CAPES IN RESPONSE TO STRONG DEEP LAYER ASCENT WITHIN EXIT REGION OF 100 KT 500 MB JET OVER CAROLINAS. ISOLATED STRONG WIND GUSTS COULD BE POSSIBLE WITH THIS ACTIVITY. HOWEVER...UNFAVORABLE TIME OF DAY...WEAK LOW LEVEL LAPSE RATES...AND LIMITED GEOGRAPHICAL AREA PRECLUDE ADDITION OF SEVERE THREAT AT THIS TIME. ANY ADDITIONAL THREAT FOR STRONG AND/OR SEVERE STORMS SHOULD DEVELOP OFFSHORE AS THE UPPER LOW AND ATTENDANT SURFACE LOW MOVE E OF THE COAST. ..PETERS.. 11/11/2006  From swody2 at goshenarc.org Sun Nov 12 05:22:51 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 12 Nov 2006 00:22:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120524 SWODY2 SPC AC 120523 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1123 PM CST SAT NOV 11 2006 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SE TX... THE UPPER WAVE DIGGING INTO THE DESERT SW APPEARS QUITE STRONG AND THE LATEST NAM DEPICTION OF SHEARING THE IMPULSE QUICKLY NEWD INTO THE MIDWEST ON MONDAY MAY BE PREMATURE. SIDING WITH 00Z GFS/12Z ECMWF WITH A SLOWER...STRONGER AND MORE SRN SOLUTION WOULD MAINTAIN ENELY BOUNDARY LAYER FLOW ALONG THE NRN GULF OF MEXICO FOR A LONGER PERIOD OF TIME INTO MON AFTN. IT DOES APPEAR THAT RETURN FLOW WILL BEGIN IN EARNEST MON NIGHT ACROSS PARTS OF ERN TX AS WEAK DISTURBANCES...PRECEEDING A POWERFUL WCOAST UPPER JET...MOVE EWD TO THE PLAINS. A WARM NOSE BETWEEN H8-H7 ACROSS TX WILL LIKELY KEEP SFC BASED CONVECTION FROM DEVELOPING...BUT SUFFICIENT MOISTENING IN THE MID-UPPER LEVELS SHOULD BE FAVORABLE FOR ELEVATED TSTMS ACROSS SERN TX BY 12Z TUE. ATTM...ELEVATED INSTABILITY SHOULD BE MINIMAL ENOUGH TO PRECLUDE SEVERE TSTMS. ...COASTAL PAC NW... STRONG AND MOIST WLY POST-FRONTAL FLOW WILL DEVELOP BENEATH STEEP LAPSE RATES ALONG CYCLONIC SIDE OF A 100+ UPPER JET MON AFTN/EVE. THIS WILL BE SUFFICIENT FOR SCATTERED TSTMS ALONG/W OF THE COASTAL RANGES. ISOLD LIGHTNING /LESS THAN 10% COVERAGE/ MAY ALSO OCCUR WELL INTO MONDAY NIGHT ACROSS THE NRN INTERMOUNTAIN WEST AS THE UPPER DISTURBANCE QUICKLY MOVES EWD. ...SERN NEW ENGLAND... SLOW MOVING NOREASTER WILL BEGIN TO AFFECT NEW ENGLAND MON INTO TUE. CONSIDERABLE AMOUNTS OF MOISTURE WILL BE DRAWN INTO THIS SYSTEM WITH ELEVATED INSTABILITY DEVELOPING MON NIGHT/EARLY TUE WITHIN HEAVIER BANDS OF PCPN TO THE NW OF THE SFC LOW. TSTMS WILL BE POSSIBLE...PRIMARILY LATE MONDAY NIGHT AS THE CYCLONE DEEPENS. ..RACY.. 11/12/2006  From swody2 at goshenarc.org Mon Nov 20 06:21:20 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Nov 2006 01:21:20 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200624 SWODY2 SPC AC 200623 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 AM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH WILL PERSIST OFF THE WRN CANADA/PAC NW COASTS...WHILE RIDGE SHIFTS SLOWLY EWD ACROSS THE SWRN AND INTO THE S CENTRAL CONUS. BETWEEN THESE TWO FEATURES...A BROAD FETCH OF WSWLY FLOW WILL REMAIN IN PLACE ACROSS THE WRN AND N CENTRAL CONUS...WHILE SPREADING EWD ACROSS THE GREAT LAKES REGION. OTHER FEATURE OF INTEREST ALOFT WILL BE A CLOSED LOW WHICH SHOULD DEEPEN WHILE MOVING SLOWLY EWD ACROSS FL THROUGH THE END OF THE PERIOD. ...PAC NW... FAST FETCH OF WSWLY FLOW ALOFT AHEAD OF UPPER TROUGH SHOULD RESULT IN SHOWERS -- AND PERHAPS A FEW LIGHTNING STRIKES -- ACROSS UPSLOPE FAVORED AREAS OF THE NWRN CONUS. ...COASTAL CAROLINAS SWD ALONG THE FL ATLANTIC COAST... COLD MID-LEVEL TEMPERATURES ASSOCIATED WITH UPPER LOW SHOULD CONTRIBUTE TO MINIMAL INSTABILITY -- AND ASSOCIATED POTENTIAL FOR MAINLY OFFSHORE THUNDER. BEST CHANCE FOR ONSHORE LIGHTNING WILL LIKELY EXIST ACROSS THE COASTAL CAROLINAS...WHERE ELY FETCH OF LOW-LEVEL MOISTURE OFF THE GULF STREAM N OF DEVELOPING SURFACE LOW MAY CONTRIBUTE TO WEAK ELEVATED INSTABILITY. ..GOSS.. 11/20/2006  From swody2 at goshenarc.org Mon Nov 20 16:41:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 20 Nov 2006 11:41:27 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201644 SWODY2 SPC AC 201643 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1043 AM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...SRN STREAM SYNOPTIC PATTERN FCST TO REMAIN HIGHLY AMPLIFIED THROUGH PERIOD...FEATURING DEEP ERN MEAN TROUGH...AND POSITIVELY TILTED RIDGE FROM NRN MEX ACROSS UPPER MS VALLEY/UPPER GREAT LAKES REGION. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SRN MS AND SERN LA -- IS FCST TO PHASE WITH ANOTHER TROUGH NOW OVER ERN KY AND DIG ESEWD. RESULTANT CLOSED CYCLONE SHOULD MOVE SLOWLY EWD ACROSS SRN GA AND FL PENINSULA...AND WILL BE ANOMALOUSLY INTENSE FOR THIS REGION. NRN STREAM PATTERN IS FCST TO DEAMPLIFY OVER CONUS. BROAD BELT OF WSWLY FLOW WILL DEVELOP FROM PACIFIC NW TO ONTARIO...DOWNSTREAM FROM SEWD-MOVING MID/UPPER LEVEL LOW NOW OVER GULF OF AK. SFC CYCLOGENESIS IS FCST JUST OFFSHORE NRN FL/SERN GA...IN RESPONSE TO APCHG/DEEPENING LOW ALOFT. SFC LOW SHOULD DEEPEN ESSENTIALLY IN PLACE...AS UPPER VORTEX APCHS AND BECOMES MORE VERTICALLY CONTINUOUS WITH SFC CYCLONE. THIS WILL REINFORCE POST COLD FRONTAL BAROCLINIC GRADIENT ALREADY IN PLACE ACROSS FL...BUT ALSO WILL STIMULATE LOW LEVEL WARM-FRONTOGENESIS OVER ATLANTIC WATERS OFFSHORE GA AND CAROLINAS. ...SRN ATLANTIC COAST... ALTHOUGH SFC BASED BUOYANCY AND BULK OF TSTMS EACH SHOULD REMAIN OFFSHORE...STRENGTHENING FRONTOGENETIC FORCING AND ELEVATED LOW LEVEL WAA WILL RESULT IN SUFFICIENT LIFT AND DESTABILIZATION TO SUPPORT POTENTIAL FOR TSTMS FROM COASTAL GA/CAROLINAS EWD. ALTHOUGH LOW-MIDLEVEL LAPSE RATES WILL BE WEAK...ELEVATED MUCAPES UP TO ABOUT 200 J/KG MAY REACH INTO FAVORABLE ICING LAYERS FOR LIGHTNING. ...WRN PACIFIC NW... APCHG MID-UPPER LEVEL LOW WILL RESULT IN INTENSIFYING LOW LEVEL WAA REGIME...AS WELL AS FRONTOGENESIS...AS NOTED IN DAY-1 OUTLOOK. POST-FRONTAL AIR MASS DAY-2 WILL BE CHARACTERIZED BY WEAK BUOYANCY BUT ALSO MINIMAL CINH OVER COASTAL/OFFSHORE WATERS OF PACIFIC...WHERE DESTABILIZATION WILL BE GREATEST...SUPPORTING OFFSHORE DEVELOPMENT OF TSTMS. SOME OF THIS ACTIVITY WILL MOVE INLAND BEFORE WEAKENING. ..EDWARDS.. 11/20/2006  From swody2 at goshenarc.org Tue Nov 21 06:40:42 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Nov 2006 01:40:42 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210644 SWODY2 SPC AC 210642 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1242 AM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN TO REMAIN RELATIVELY UNCHANGED ON THE LARGE SCALE...WITH UPPER TROUGH OFF THE W COAST OF NOAM MAKING SLOW EWD/ONSHORE PROGRESS...WHILE UPPER LOW DRIFTS SLOWLY NWD FROM JUST OFF THE N FL/GA COAST TO THE COASTAL CAROLINAS BY THE END OF THE PERIOD. THOUGH THUNDER THREAT SHOULD AGAIN REMAIN LIMITED...A FEW ONSHORE STRIKES ARE ONCE AGAIN ANTICIPATED ACROSS PORTIONS OF THE MID-ATLANTIC COAST AND COASTAL CAROLINAS INVOF UPPER LOW. MEANWHILE...SPORADIC STRIKES ARE ALSO ANTICIPATED OVER PORTIONS OF WRN WA/WRN ORE -- PARTICULARLY AS A STRONGER SHORT-WAVE TROUGH MOVES ONSHORE DURING THE SECOND HALF OF THE PERIOD. IN BOTH OF THESE AREAS HOWEVER...VERY LIMITED INSTABILITY SHOULD PRECLUDE ANY APPRECIABLE SEVERE THREAT. ..GOSS.. 11/21/2006  From swody2 at goshenarc.org Tue Nov 21 16:22:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 21 Nov 2006 11:22:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211625 SWODY2 SPC AC 211624 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1024 AM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...COASTAL SECTIONS OF NC/SERN VA/ERN SHORES MD... STRONG UPPER LOW IS EXPECTED TO WOBBLE NWD ALONG THE SERN ATLANTIC COAST TO THE NC OUTER BANKS BY 12Z THU. WARM CONVEYOR WILL WRAP GULF STREAM PARCELS TO NWRN QUADRANT OF THE MATURE LOW RESULTING IN SUFFICIENT ELEVATED INSTABILITY FOR SPORADIC LIGHTNING STRIKES WITHIN STRONGER ONSHORE BANDING STRUCTURES. HIGHER TSTM PROBABILITIES WILL BE CONFINED TO WED NIGHT ALONG THE NC OUTER BANKS NWD TO THE ERN SHORES MD. ...PAC NW... MAIN PORTION OF THE STUBBORN GULF OF AK UPPER LOW WILL DISLODGE AND COME ASHORE THE PAC NW WED AFTN/NIGHT. H5 TEMPERATURES AOB MINUS 30 DEG C ASSOCD WITH THE TROUGH WILL SPREAD ACROSS WA...ORE...NRN CA AND WRN ID DURING THE PROGRESS OF THE DAY. HIGHEST TSTM PROBABILITIES WILL FAVOR THE COASTAL RANGES WHERE THE MOIST UPSLOPE FLOW COMBINES WITH THE STEEPENING MID-TROPOSPHERIC LAPSE RATES AND CYCLONIC FLOW. TSTMS MAY ALSO OCCUR INLAND OVER THE HIGHER TERRAIN OF ERN WA/ORE AND WRN ID WED NIGHT...BUT COVERAGE SHOULD BE ISOLD AND LESS THAN 10 PERCENT. ..RACY.. 11/21/2006 WWWW From swody2 at goshenarc.org Wed Nov 22 06:49:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Nov 2006 01:49:31 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220652 SWODY2 SPC AC 220650 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH IS FORECAST TO EXPAND/DEEPEN WHILE SHIFTING EWD ACROSS THE WRN HALF OF THE CONUS...AS LEAD SHORT-WAVE TROUGH MOVES INTO THE CENTRAL PLAINS LATE. MEANWHILE...UPPER LOW INITIALLY INVOF THE VA/NC COAST IS FORECAST TO MOVE NNEWD AND WEAKEN THROUGH THE END OF THE PERIOD. SOME THUNDER WILL BE POSSIBLE OVER PARTS OF THE PAC NW -- PARTICULARLY THE WRN THIRD OF WA/ORE...AS WELL AS PORTIONS OF THE ATLANTIC COAST FROM SRN NEW ENGLAND TO THE COASTAL NC. HOWEVER...STABLE AIRMASS IS FORECAST TO PERSIST ACROSS THE CENTRAL CONUS AHEAD OF APPROACHING UPPER FEATURE AND ASSOCIATED COLD FRONT...PRECLUDING THE THREAT FOR DEEP MOIST CONVECTION. ..GOSS.. 11/22/2006 WWWW From swody2 at goshenarc.org Wed Nov 22 16:50:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 22 Nov 2006 11:50:08 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221653 SWODY2 SPC AC 221652 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1052 AM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID-UPPER LEVEL PATTERN CHANGE WILL BE UNDERWAY DURING THIS PERIOD AS MEAN ERN TROUGH WEAKENS AND HEIGHTS FALL ACROSS MUCH OF WRN CONUS. AS THIS OCCURS...ANOMALOUSLY DEEP/COLD CYCLONIC VORTEX NOW OFFSHORE SC/GA IS FCST TO CONTINUE FILLING AND TO EJECT NEWD OVER GULF STREAM. ASSOCIATED SFC CYCLONE -- ANALYZED ATTM OVER NC OUTER BANKS -- SHOULD BE JUST OFFSHORE NERN NC AROUND 23/12Z...LIKEWISE LIFTING NEWD OVER ATLANTIC WATERS. MEANWHILE...SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OFFSHORE ORE/NRN CA -- WILL MOVE EWD QUICKLY FROM INTERIOR PACIFIC NW TO NRN PLAINS DAY-2. THIS WILL ENGENDER STRONG SFC CYCLOGENESIS ACROSS NRN HIGH PLAINS...IN LEE OF ROCKIES. RESULTANT SFC LOW SHOULD LIFT NEWD OVER PORTIONS SRN SASK/MB BY 24/12Z. HOWEVER...MOISTURE IN WARM SECTOR OF THIS SYSTEM WILL BE TOO SCANT TO SUPPORT CONVECTIVE POTENTIAL. FARTHER NW...MID-UPPER LEVEL SPEED MAX NOW DIGGING SWD FROM SRN GULF OF AK SHOULD PIVOT EWD...WITH ASSOCIATED TROUGH MOVING ASHORE WA/ORE BETWEEN 24/00-24/06Z. ...PACIFIC NW... DEEP-LAYER AIR MASS SHOULD BE SLIGHTLY MORE STABLE IN WAKE OF STRONG TROUGH NOW OFFSHORE CA/ORE. HOWEVER...LARGE SCALE FORCING ASSOCIATED WITH UPSTREAM PERTURBATION SHOULD STEEPEN LOW-MIDLEVEL LAPSE RATES...IN ENVIRONMENT OF WEAK CINH AND MARINE MOISTURE. THIS WILL SUPPORT ISOLATED/EPISODIC THUNDER RISK FOR PORTIONS WRN WA/ORE. ...ERN NC... TSTM OUTLOOK IS MRGL AND VALID FOR FIRST FEW HOURS OF PERIOD. GEN TSTM REGIME ALREADY DESCRIBED IN DAY-1 OUTLOOK MAY LINGER PAST 23/12Z BEFORE DEEP-TROPOSPHERIC CYCLONE AND ASSOCIATED WARM CONVEYOR EXIT AREA. ..EDWARDS.. 11/22/2006  From swody2 at goshenarc.org Thu Nov 23 05:14:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 00:14:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230517 SWODY2 SPC AC 230516 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 PM CST WED NOV 22 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... UPPER RIDGE IS FORECAST TO PREVAIL ACROSS THE ERN CONUS THIS PERIOD...AS TROUGH OFF THE ATLANTIC COAST PROGRESSES EWD. MEANWHILE...TROUGH OVER THE WRN HALF OF THE CONUS AT THE START OF THE PERIOD IS FORECAST TO DEEPEN/EXPAND SLOWLY EWD. WITH SURFACE RIDGE FORECAST TO REMAIN OVER THE GULF OF MEXICO...MOISTURE RETURN INTO THE CENTRAL CONUS SHOULD PROVE INSUFFICIENT TO SUPPORT THUNDERSTORM DEVELOPMENT INVOF WEAK BAROCLINIC ZONE WHICH IS FORECAST TO BECOME ESTABLISHED OVER THE CENTRAL PLAINS. ELSEWHERE...DEEP MOIST CONVECTION IS NOT ANTICIPATED THROUGH THE PERIOD. ..GOSS.. 11/23/2006  From swody2 at goshenarc.org Thu Nov 23 17:09:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 12:09:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231712 SWODY2 SPC AC 231710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST THU NOV 23 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... AN UPPER-LEVEL RIDGE IS FORECAST TO BE IN PLACE ACROSS THE ERN UNITED STATES FRIDAY. A SOUTHWEST FLOW REGIME SHOULD REMAIN IN PLACE ACROSS THE WRN AND CNTRL STATES. ALTHOUGH ADEQUATE LARGE-SCALE FORCING WILL EXIST ESPECIALLY IN THE NCNTRL UNITED STATES...MOISTURE WILL LIKELY NOT BE SUFFICIENT FOR THUNDERSTORM ACTIVITY ACROSS CONUS DURING THE DAY 2 PERIOD. ..BROYLES.. 11/23/2006  From swody2 at goshenarc.org Fri Nov 24 04:51:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 23 Nov 2006 23:51:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 240454 SWODY2 SPC AC 240453 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1053 PM CST THU NOV 23 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SLOW EWD PROGRESSION OF WRN CONUS LONG WAVE TROUGH /COMPRISED OF DISTINCT POLAR AND SUBTROPICAL JET BRANCHES/ IS FORECAST DURING THE DAY TWO PERIOD WITH PERSISTENT RIDGING OVER THE SERN STATES. SHORT WAVE TROUGH NOW NEAR 30N AND 126W IS FORECAST TO TRANSLATE THROUGH THE SUBTROPICAL BRANCH...EVENTUALLY LIFTING NEWD INTO THE UPPER MIDWEST SATURDAY NIGHT. IN THE LOW-LEVELS...PRIMARY BAROCLINIC ZONE WILL EXIST FROM LOW PRESSURE OVER THE NRN HIGH PLAINS EWD INTO THE UPPER GREAT LAKES WITH DOMINANT RIDGING FROM THE CANADIAN MARITIMES INTO THE GULF OF MEXICO. THIS RIDGING WILL TEND TO LIMIT THE DEGREE/QUALITY OF LOW-LEVEL MOISTURE RETURN ACROSS TX/LA. ...PACIFIC NW COAST TO NRN ROCKIES... COLD MID-LEVEL TEMPERATURES /-25 TO -35 C AT 500 MB/ WILL BE MAINTAINED THROUGH THE PERIOD ON CYCLONIC SIDE OF POLAR JET...EFFECTIVELY CONTRIBUTING TO STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. STRONG SHORT WAVE TROUGH INITIALLY OVER WA/ORE SATURDAY MORNING WILL SHIFT EWD...LIKELY PROVIDING SUFFICIENT BACKGROUND DESTABILIZATION/FORCING FOR ISOLATED TSTM DEVELOPMENT ACROSS THE NRN INTERMOUNTAIN REGION INTO SATURDAY EVENING. FARTHER UPSTREAM ALONG THE WA/ORE COAST...THE STEEP LAPSE RATES COUPLED WITH MOIST ONSHORE FLOW AND HEIGHT FALLS AHEAD OF NEXT SHORT WAVE TROUGH DROPPING SEWD FROM THE GULF OF AK WILL BE SUPPORTIVE OF ISOLATED TSTMS AS WELL. ...SWRN DESERTS INTO THE FOUR CORNERS REGION... SHORT WAVE TROUGH EMBEDDED IN SUBTROPICAL BRANCH INITIALLY ALONG OR JUST OFF THE SRN CA COAST IS EXPECTED TO MOVE EWD THROUGH THE LOWER CO VALLEY AND EVENTUALLY THE FOUR CORNERS REGION SATURDAY AND SATURDAY NIGHT. DEVELOPING STEEP LAPSE RATES AHEAD OF THIS FEATURE WILL LARGELY CONTRIBUTE TO WEAK CONVECTIVE INSTABILITY...ESPECIALLY DURING THE MID/LATE AFTERNOON AND EARLY EVENING HOURS...FOR ISOLATED TO SCATTERED TSTMS FROM AZ NEWD INTO WRN/CNTRL CO. ...UPPER MIDWEST... AS MENTIONED ABOVE...LEAD SRN BRANCH IMPULSE NOW NEAR 30N AND 126W IS FORECAST TO LIFT NEWD TOWARD THE REGION...THOUGH LATEST MODEL GUIDANCE INDICATE SLIGHT TIMING DIFFERENCES. IT APPEARS SOME POTENTIAL EXISTS FOR AT LEAST A FEW ELEVATED TSTMS...MAINLY SATURDAY NIGHT...AS LOW-LEVEL WAA AND ISENTROPIC ASCENT INCREASE AHEAD OF THE SHORT WAVE TROUGH. ..MEAD.. 11/24/2006  From swody2 at goshenarc.org Fri Nov 24 17:25:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 24 Nov 2006 12:25:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 241727 SWODY2 SPC AC 241725 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CST FRI NOV 24 2006 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... A SOUTHWEST FLOW PATTERN WILL REMAIN IN PLACE THROUGH SATURDAY ACROSS MOST OF THE CONUS WITH A BROAD UPPER-LEVEL TROUGH OVER THE WRN UNITED STATES. ISOLATED THUNDERSTORM ACTIVITY MAY OCCUR IN THE HIGHER TERRAIN OF THE PACIFIC NORTHWEST AND IN THE FOUR CORNERS REGION DUE TO DAYTIME HEATING AND COLD TEMPS ALOFT. OTHER CONVECTION MAY DEVELOP ALONG A WARM FRONT SATURDAY NIGHT AS A BOUNDARY LIFTS NWD ACROSS THE UPPER MIDWEST. NO SEVERE THREAT IS EXPECTED WITH ANY OF THE THUNDERSTORM ACTIVITY ACROSS THE CONUS SATURDAY AND SATURDAY NIGHT. ..BROYLES.. 11/24/2006  From swody2 at goshenarc.org Sat Nov 25 05:26:38 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Nov 2006 00:26:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250529 SWODY2 SPC AC 250527 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 PM CST FRI NOV 24 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG HEIGHT FALLS ARE FORECAST FROM THE PACIFIC NW INTO NRN/CNTRL CA AS INTENSE MID AND UPPER-LEVEL JET STREAKS DIG SEWD FROM THE NERN PACIFIC OCEAN TOWARD THE GREAT BASIN. AS THIS OCCURS... AMPLIFICATION OF WRN U.S. TROUGH WILL OCCUR...ANCHORED BY VORTEX OVER SRN BRITISH COLUMBIA/WA. MEANWHILE...A SUBTROPICAL JET BRANCH WILL REMAIN ACTIVE WITH SEVERAL EMBEDDED SHORT WAVE TROUGHS TRANSLATING NEWD THROUGH THE MEAN FLOW REGIME FROM NRN MEXICO TO THE UPPER GREAT LAKES. IN THE LOW-LEVELS...ARCTIC COLD FRONT FROM THE NRN ROCKIES INTO UPPER MS VALLEY WILL SLOWLY PUSH SWD THROUGH THE DAY TWO PERIOD. ELSEWHERE...A DEEP SURFACE LOW WILL MOVE INTO WA/ORE WITH ATTENDANT PACIFIC FRONT PUSHING SEWD TOWARD THE GREAT BASIN. ...PACIFIC NW COAST SWD ALONG THE NRN/CNTRL CA COAST... AS MENTIONED ABOVE...STRONG HEIGHT FALLS ARE FORECAST ACROSS THE REGION SUNDAY/SUNDAY NIGHT AS MEAN TROUGH INTENSIFIES ON CYCLONIC SIDE OF MID AND UPPER-LEVEL JET STREAKS DIGGING SSEWD ALONG THE PACIFIC COAST. AS THIS OCCURS LAPSE RATES WILL STEEPEN OWING TO THE FORCING/COOLING ALOFT WITH POCKETS OF WEAK CONVECTIVE INSTABILITY DEVELOPING. IT APPEARS THE BEST POTENTIAL FOR A FEW TSTMS WILL EXIST ALONG PACIFIC COLD FRONT AS IT APPROACHES THE COAST...AS WELL AS WITHIN MOIST...POST-FRONTAL ONSHORE FLOW REGIME DEVELOPING SUNDAY NIGHT. ...UPPER MIDWEST INTO MIDDLE/LOWER MO VALLEY... LOW-LEVEL MOISTURE IS EXPECTED TO REMAIN RATHER LIMITED WITH DEWPOINTS COMMONLY IN THE 40S TO PERHAPS LOWER 50S AHEAD OF SURFACE FRONT. HOWEVER...A PLUME OF RELATIVELY STEEP MID-LEVEL LAPSE RATES ORIGINATING FROM THE CNTRL ROCKIES WILL BE ADVECTED NEWD INTO THE REGION AHEAD OF SHORT WAVE TROUGH LIFTING OUT OF THE CNTRL HIGH PLAINS....EFFECTIVELY CONTRIBUTING TO WEAK CONVECTIVE INSTABILITY. SUSTAINED FRONTAL CONVERGENCE COUPLED WITH INCREASED LARGE-SCALE FORCING FOR ASCENT WITH APPROACHING SHORT WAVE TROUGH WILL LIKELY CONTRIBUTE TO THE DEVELOPMENT OF ISOLATED TSTMS LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. SOME SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...THOUGH THE MARGINAL INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ..MEAD.. 11/25/2006  From swody2 at goshenarc.org Sat Nov 25 17:26:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 25 Nov 2006 12:26:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 251729 SWODY2 SPC AC 251727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST SAT NOV 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... AN UPPER-LEVEL TROUGH OVER THE PACIFIC NORTHWEST WILL DRIFT ENEWD INTO SRN CANADA TONIGHT AS ANOTHER SHORTWAVE TROUGH REPLACES IT IN THE NWRN UNITED STATES SUNDAY. THUNDERSTORM ACTIVITY MAY OCCUR IN THE COASTAL SECTIONS OF WA...ORE AND NRN CA AS STRONG LARGE-SCALE ASCENT ASSOCIATED WITH THE TROUGH MOVES INLAND SUNDAY AFTERNO0N. THE ONLY OTHER AREA ACROSS THE CONUS WITH POTENTIAL FOR CONVECTION WILL BE IN THE UPPER MIDWEST. A FEW THUNDERSTORMS MAY OCCUR ALONG A COLD FRONT FORECAST TO MOVE SEWD ACROSS IA SUNDAY. THE THUNDERSTORM ACTIVITY ACROSS THE CONUS ON SUNDAY AND SUNDAY NIGHT SHOULD REMAIN WELL BELOW SEVERE LIMITS DUE TO WEAK INSTABILITY. ..BROYLES.. 11/25/2006  From swody2 at goshenarc.org Sun Nov 26 05:16:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Nov 2006 00:16:59 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260519 SWODY2 SPC AC 260518 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 PM CST SAT NOV 25 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SLOW EWD PROGRESSION/DEVELOPMENT OF WRN U.S. LONG WAVE TROUGH /ANCHORED BY VORTEX OVER THE PACIFIC NW/ IS FORECAST DURING THE DAY TWO PERIOD WITH PERSISTENT RIDGING IN THE SE. WITHIN THIS REGIME...ELONGATED...LEAD SHORT WAVE TROUGH INITIALLY FROM THE MID MO VALLEY SWWD TO THE SRN HIGH PLAINS MONDAY MORNING WILL LIFT NEWD INTO THE UPPER GREAT LAKES WHILE STRONGER UPSTREAM SYSTEM EJECTS FROM THE ROCKIES INTO THE GREAT PLAINS MONDAY NIGHT INTO TUESDAY MORNING. IN THE LOW-LEVELS...SURFACE FRONT EXTENDING FROM LOW PRESSURE OVER SWRN KS NEWD INTO THE MIDWEST WILL LIFT NWD THROUGH THE PERIOD IN RESPONSE TO INCREASING PRESSURE FALLS OVER THE NRN/CNTRL HIGH PLAINS. A WEAK LOW ATTENDANT TO THE LEAD SHORT WAVE TROUGH IS FORECAST TO DEVELOP NEWD ALONG THIS RETREATING BOUNDARY WHILE PRIMARY CYCLONE CONCURRENTLY DEEPENS OVER WY. THIS STRONGER LOW IS THEN EXPECTED TO DEVELOP GENERALLY EWD INTO SD BY TUESDAY MORNING. ...CNTRL/ERN KS THROUGH THE MID MO VALLEY... LATEST SHORT RANGE MODEL GUIDANCE REMAINS CONSISTENT IN SUGGESTING THAT SEPARATE CONVECTIVE EPISODES ARE POSSIBLE DURING THE DAY TWO PERIOD. ISOLATED/SCATTERED TSTMS /MAINLY ELEVATED/ ARE EXPECTED TO BE ONGOING OR DEVELOP EARLY IN THE PERIOD MONDAY MORNING OVER THE MID MO VALLEY PERHAPS INTO CNTRL IA...DRIVEN BY LOW-LEVEL WAA ALONG NOSE OF SWLY LLJ AND DEEPER LAYER FORCING FOR ASCENT ASSOCIATED WITH LEAD SHORT WAVE TROUGH. OVER THE COURSE OF THE DAY...THIS ACTIVITY IS FORECAST TO SHIFT INTO PARTS OF SRN MN/SWRN WI WITH BACKBUILDING DEVELOPMENT POSSIBLE INTO ERN KS. LAPSE RATES AND RESULTANT INSTABILITY ARE EXPECTED TO REMAIN QUITE MARGINAL WITH STORMS LIKELY REMAINING BELOW SEVERE LEVELS. A POTENTIALLY GREATER THREAT OF ISOLATED...SEVERE STORMS WILL EXIST DURING THE LATTER HALF OF THE PERIOD IN ADVANCE OF STRONGER SHORT WAVE TROUGH MOVING OUT OF THE ROCKIES. BOUNDARY LAYER MOISTURE WILL REMAIN MODEST WITH DEWPOINTS COMMONLY IN THE LOW/MID 50S. HOWEVER...A PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL PRECEDE THIS STRONGER IMPULSE...CONTRIBUTING TO MUCAPES OF 500-900 J/KG. TSTMS ARE FORECAST TO BECOME INCREASINGLY LIKELY AFTER 28/00Z ALONG LEE TROUGH/WEAK DRYLINE FROM PORTIONS OF WRN OK INTO CNTRL KS. ACTIVITY SHOULD TEND TO INCREASE IN COVERAGE AND INTENSITY MONDAY NIGHT ACROSS CNTRL/ERN KS INTO THE MID MO VALLEY AS STRONGER DYNAMIC FORCING OVERSPREADS REGION. FORECAST SOUNDINGS INDICATE THAT VERTICAL SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF ORGANIZED/ROTATING STORMS CAPABLE OF SEVERE HAIL AND LOCALLY DAMAGING WINDS. GIVEN THAT THIS GREATEST STORM THREAT WILL EXIST DURING THE NIGHTTIME HOURS...PRIMARY UNCERTAINTIES ARE DEGREE OF INSTABILITY AND WHETHER OR NOT STORMS WILL REMAIN ROOTED IN BOUNDARY LAYER OR BECOME SLIGHTLY ELEVATED. THEREFORE...ONLY LOW SEVERE PROBABILITIES HAVE BEEN INCLUDED. ..MEAD.. 11/26/2006  From swody2 at goshenarc.org Sun Nov 26 17:27:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 26 Nov 2006 12:27:49 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261730 SWODY2 SPC AC 261728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST SUN NOV 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... A BROAD ZONE OF SOUTHWEST FLOW WILL REMAIN IN PLACE ACROSS THE CONUS THROUGH THE DAY 2 PERIOD AS A POWERFUL UPPER-LOW DEVELOPS AND MOVES INLAND ACROSS THE PACIFIC NORTHWEST. SOME THUNDERSTORM ACTIVITY MAY DEVELOP IN THE PACIFIC NORTHWEST AND IN THE INTERMOUNTAIN WEST MONDAY ASSOCIATED WITH THE STRONG ASCENT AHEAD OF THE APPROACHING LOW/TROUGH. THE GREATEST THREAT FOR THUNDERSTORM ACTIVITY SHOULD OCCUR IN THE PLAINS AND UPPER MIDWEST WHERE A STRONG LOW-LEVEL JET IS FORECAST TO DEVELOP MONDAY AND MONDAY NIGHT. ALTHOUGH INSTABILITY/MOISTURE RETURN WILL REMAIN WEAK ACROSS THE REGION...SCATTERED THUNDERSTORMS MAY DEVELOP IN A REGION OF WARM ADVECTION FROM OK/N TX EXTENDING NNEWD INTO IA/MN AND WI. THUNDERSTORM COVERAGE WOULD LIKELY BE GREATEST FROM NEAR PEAK HEATING INTO THE EVENING HOURS AS THE LOW-LEVEL JET STRENGTHENS. A FEW OF THE BETTER ORGANIZED THUNDERSTORMS COULD CONTAIN HAIL DUE TO COLD TEMPS ALOFT AND STEEPENING LAPSE RATES AS MID-LEVEL FLOW STRENGTHENS AHEAD OF A STRONG MID-LEVEL JET EJECTING OUT OF THE BASE OF THE TROUGH. ..BROYLES.. 11/26/2006  From swody2 at goshenarc.org Mon Nov 27 05:47:48 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 27 Nov 2006 00:47:48 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270550 SWODY2 SPC AC 270548 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST SUN NOV 26 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... DYNAMIC LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY TWO PERIOD CHARACTERIZED BY DEEP TROUGH SHIFTING EWD THROUGH THE INTERMOUNTAIN W INTO THE PLAINS AND PERSISTENT RIDGING OVER THE SERN STATES. WITHIN THIS BROADER PATTERN...SHORT WAVE TROUGH INITIALLY OVER THE NRN/CNTRL PLAINS WILL LIFT NNEWD INTO MANITOBA AND WRN ONTARIO...POTENTIALLY FORMING A CLOSED LOW OVER THIS REGION. MEANWHILE...STRONG MID AND UPPER-LEVEL JET STREAKS FROM THE PACIFIC NW COAST TO THE GREAT BASIN WILL DIG SEWD WITH HEIGHT FALLS DEVELOPING THROUGH THE FOUR CORNERS REGION INTO SRN HIGH PLAINS. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO LEAD SHORT WAVE TROUGH WILL DEVELOP NEWD FROM NRN NEB OR SRN SD INTO WRN ONTARIO WITH SECONDARY LOW PRESSURE DEVELOPING ALONG ARCTIC COLD FRONT SURGING SWD THROUGH THE CNTRL INTO SRN HIGH PLAINS. ...CNTRL LOW PLAINS/LOWER MO VALLEY INTO THE UPPER GREAT LAKES... CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING TUESDAY MORNING FROM PORTIONS OF THE MID MO VALLEY AND MIDWEST SWD INTO THE ERN KS AND WRN/NRN MO. DPVA ASSOCIATED WITH LEAD SHORT WAVE TROUGH COUPLED WITH LOWER LEVEL ISENTROPIC ASCENT WILL BE THE PRIMARY MECHANISMS FOCUSING THIS ACTIVITY WITHIN THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY MODEST MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 500-700 J/KG. SOME OF THE STRONGER STORMS WILL BE CAPABLE OF SMALL TO POTENTIALLY MARGINALLY SEVERE HAIL THROUGH THE MORNING...THOUGH THIS THREAT APPEARS TOO MARGINAL FOR INCLUSION OF SEVERE PROBABILITIES. THESE STORMS SHOULD TEND TO MOVE/DEVELOP NEWD INTO THE UPPER GREAT LAKES TUESDAY AFTERNOON WITH STORMS WEAKENING WITH TIME AS THEY BECOME INCREASINGLY ELEVATED IN PROGRESSIVELY MORE STABLE ENVIRONMENT. ADDITIONAL STORM DEVELOPMENT IS POSSIBLE ALONG COLD FRONT TUESDAY NIGHT FROM PORTIONS OF CNTRL/ERN IA SWWD INTO ERN KS/MO AS BOUNDARY ENCOUNTERS LOW-LEVEL MOISTURE AXIS. SOME THREAT OF ISOLATED...SEVERE STORMS WILL EXIST WITH THIS NOCTURNAL DEVELOPMENT...PARTICULARLY ACROSS ERN KS GIVEN THE STRONG VERTICAL SHEAR PROFILES FORECAST. NO SEVERE PROBABILITIES WILL BE INCLUDED AT THIS POINT DUE TO THE POTENTIAL LIMITING EFFECTS OF THE EXPECTED WEAK INSTABILITY. ..MEAD.. 11/27/2006  From swody2 at goshenarc.org Mon Nov 27 17:12:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 27 Nov 2006 12:12:28 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 271714 SWODY2 SPC AC 271713 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CST MON NOV 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT WAVE ENERGY ROTATING THROUGH LARGE SCALE WRN NORTH AMERICAN UPPER TROUGH WILL PRODUCE AREAS OF MODEST TO STRONG HEIGHT FALLS FROM THE ROCKIES TO THE CNTRL AND NRN PLAINS THROUGH TUESDAY. THIS WILL CAUSE THE AXIS OF THE LARGE SCALE TROUGH TO TRANSLATE EWD FROM THE INTERIOR NORTHWEST TO THE NRN ROCKIES/FOUR CORNERS REGIONS OVER THE NEXT COUPLE OF DAYS. MEANWHILE...A STRONG AND PERSISTENT UPPER RIDGE WILL REMAIN NEARLY STATIONARY ACROSS THE SOUTHEAST AND ADJACENT ATLANTIC COASTAL WATERS. AN EXTENSIVE BELT OF STRONG SWLY MID LEVEL FLOW AND ASSOCIATED DEEP-LAYER BAROCLINIC ZONE WILL BE SITUATED BETWEEN THE WRN TROUGH AND SERN RIDGE. LIFT AND MOISTURE FLUX WITHIN WARM CONVEYOR BELT TO THE EAST OF SW/NE ORIENTED DEEP-LAYER BAROCLINIC ZONE WILL SUSTAIN SCATTERED TSTMS THIS PERIOD. ...SRN PLAINS ACROSS THE MO RIVER VALLEY... TSTMS...PRIMARILY ROOTED ABOVE A MORE STABLE BOUNDARY LAYER...ARE POSSIBLE TUESDAY MORNING FROM THE RED RIVER VALLEY OF NERN TX/SERN OK...NNEWD ACROSS THE MID TO LOWER MO RIVER VALLEY. CONVECTIVE ACTIVITY APPEARS MOST LIKELY NEAR THE NOSE OF THE LLJ...AND IN ASSOCIATION WITH STRONGER DYNAMIC FORCING AND STEEPER LAPSE RATES ACCOMPANYING A LOW AMPLITUDE SHORT WAVE TROUGH EJECTING NEWD ACROSS THE CNTRL PLAINS. MUCAPE VALUES OF 500-1000 J/KG ARE FORECAST ACROSS THE PLAINS REGIONS AND A COUPLE OF THE STRONGER STORM UPDRAFTS COULD PRODUCE SMALL TO MARGINALLY SEVERE HAIL...FROM ERN NEB ACROSS IA AND NRN MO...INTO THE AFTERNOON. STRONGER FORCING ASSOCIATED WITH THE LEAD SHORT WAVE TROUGH WILL LIFT AWAY FROM THE INSTABILITY AXIS THROUGH THE FIRST PART OF THE DAY AND SEVERE HAIL POTENTIAL CURRENTLY APPEARS TOO LIMITED IN TIME/SPACE TO JUSTIFY A PROBABILITY FORECAST. ACTIVITY WILL TEND TO MOVE/DEVELOP NEWD TOWARD THE WRN GREAT LAKES THROUGH THE AFTERNOON WITH STORMS GENERALLY WEAKENING WITH TIME. A REPRIEVE FROM DEEP CONVECTION MAY OCCUR FOR A TIME TUESDAY EVENING BETWEEN THE NRN PLAINS/GREAT LAKES SHORT WAVE TROUGH AND THE NEXT UPSTREAM IMPULSE APPROACHING THE PLAINS FROM THE ROCKIES. LIFT ASSOCIATED WITH THIS NEXT SYSTEM SHOULD ENHANCE CONVERGENCE AND RESULT IN POSSIBLE TSTM DEVELOPMENT ALONG THE COLD FRONT TUESDAY NIGHT AND EARLY WEDNESDAY MORNING...FROM NRN IA ACROSS MN/WI. ADDITIONAL ISOLATED STORMS MAY FORM LATE IN THE PERIOD WITHIN PERSISTENT WARM/MOIST CONVEYOR BELT...AND AHEAD OF THE COLD FRONT...FROM CNTRL OK ACROSS THE OZARKS. WHILE ISOLATED HAIL WILL BE POSSIBLE WITH THIS NOCTURNAL DEVELOPMENT GIVEN STRONG VERTICAL SHEAR AND INCREASINGLY STRONG FORCING...OVERALL SEVERE POTENTIAL SHOULD BE LIMITED BY WEAK INSTABILITY. ..CARBIN.. 11/27/2006  From swody2 at goshenarc.org Tue Nov 28 09:07:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 28 Nov 2006 04:07:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280909 SWODY2 SPC AC 280907 DAY 2 CONVECTIVE OUTLOOK RESENT 4 NWS STORM PREDICTION CENTER NORMAN OK 0307 AM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN KS/SWRN MO SWD INTO N-CNTRL AND NERN TX... ...SYNOPSIS... A PROGRESSIVE WAVE TRAIN IS FORECAST FROM THE NERN PACIFIC AND WRN CANADA EWD INTO CNTRL CANADA AND THE N-CNTRL TIER OF STATES. MEANWHILE...A SLOWER EWD MOVEMENT OF DEEP...LOW LATITUDE TROUGH IS EXPECTED FROM THE SRN ROCKIES INTO THE SRN HIGH PLAINS. IN THE LOW-LEVELS...SURFACE COLD FRONT INITIALLY FROM LOW PRESSURE OVER LAKE SUPERIOR SWWD TO SECONDARY LOW PRESSURE OVER THE TX S PLAINS WILL PUSH SEWD THROUGH THE PERIOD...EXTENDING FROM CNTRL LOWER MI TO THE LOWER RIO GRANDE VALLEY BY THURSDAY MORNING. ...LOWER MO VALLEY SWD INTO NERN TX... 28/00Z SOUNDINGS WITHIN LOW-LEVEL MOISTURE AXIS ACROSS THE SRN PLAINS INDICATE THAT PRE-FRONTAL AIR MASS IS ALREADY WEAKLY TO MODERATELY UNSTABLE WITH MUCAPES OF 500-1000 J/KG. PERSISTENT SLY FLOW AHEAD OF COLD FRONT WILL RESULT IN A FURTHER INCREASE IN BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA...SUPPORTING MUCAPES OF 1000-1500 J/KG BY WEDNESDAY AFTERNOON. INSTABILITY IS FORECAST TO DECREASE WITH NEWD EXTENT WITH MUCAPES OF 500-800 J/KG MORE LIKELY TOWARD THE LOWER MO VALLEY. TSTMS ARE EXPECTED TO BE ONGOING WEDNESDAY MORNING ALONG FRONT OVER PORTIONS OF IA WITHIN WEAKLY UNSTABLE AIR MASS. INCREASING HEIGHT FALLS/DYNAMIC LARGE-SCALE FORCING FOR ASCENT SHOULD SUPPORT SWWD STORM DEVELOPMENT ALONG/AHEAD OF FRONT BY AFTERNOON AS BOUNDARY LAYER BECOMES INCREASINGLY UNSTABLE. VERTICAL SHEAR PROFILES ALONG LENGTH OF FRONTAL ZONE WILL BE QUITE FAVORABLE FOR ORGANIZED STORMS INCLUDING SUPERCELLS GIVEN 50-65 KT OF EFFECTIVE BULK SHEAR. CURRENTLY...IT APPEARS THAT INSTABILITY WILL REMAIN QUITE MARGINAL ACROSS NRN AND CNTRL MO...WHICH COULD POTENTIALLY LIMIT A MORE SUBSTANTIAL SEVERE THREAT. MODEL TRENDS WILL BE MONITORED AND AN UPGRADE TO SLIGHT RISK MAY BE NECESSARY IN LATER OUTLOOKS. AN APPARENT GREATER SEVERE STORM THREAT WILL EXIST FROM SERN KS/SWRN MO SSWWD INTO THE ERN HALF OF OK AND N-CNTRL/NERN TX WHERE AIR MASS IS FORECAST TO BECOME MORE UNSTABLE. SUPERCELLS ARE POSSIBLE GIVEN THE STRONGLY SHEARED ENVIRONMENT...THOUGH CONVECTION SHOULD TEND TO EVOLVE TO MORE OF A LINEAR STRUCTURE OWING TO THE ANAFRONTAL CHARACTERISTICS OF THE COLD FRONT. DAMAGING WINDS AND SEVERE HAIL APPEAR TO BE THE MAIN THREATS WITH THE STRONGEST STORMS. MORE BROKEN...CELLULAR STORM DEVELOPMENT WILL BE POSSIBLE LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT SWD ALONG TROUGH OR DRYLINE ATTENDANT TO COLD FRONT INTO N-CNTRL AND CNTRL TX. SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE HAIL AND PERHAPS A COUPLE OF TORNADOES OWING TO THE ANTICIPATED MORE DISCRETE NATURE OF THE STORMS. ACTIVITY SHOULD EVOLVE INTO A QUASI-LINEAR MCS OVERNIGHT AS COLD FRONT OVERTAKES TROUGH/DRYLINE WITH ASSOCIATED WIND/HAIL THREAT DEVELOPING TOWARD THE ARKLATEX. ..MEAD.. 11/28/2006  From swody2 at goshenarc.org Tue Nov 28 17:34:59 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 28 Nov 2006 12:34:59 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281737 SWODY2 SPC AC 281735 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1135 AM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX/OK NEWD TO WRN IL... ...SYNOPSIS... SIGNIFICANT LARGE SCALE PATTERN CHANGE IS FORECAST OVER THE CNTRL U.S THROUGH WEDNESDAY AS A DEEP UPPER TROUGH...CURRENTLY ENCOMPASSING THE INTERMOUNTAIN WEST...TRANSLATES EWD. WHILE A PORTION OF SHORT WAVE ENERGY ASSOCIATED WITH THE LARGER SCALE TROUGH SYSTEM EJECTS NEWD FROM MT INTO SRN CANADA...ANOTHER VIGOROUS LOBE OF VORTICITY AND ITS ASSOCIATED JET SEGMENT WILL TRACK ACROSS THE GREAT BASIN AREA THROUGH TONIGHT...AND RESULT IN HEIGHT FALLS SPREADING EWD/SEWD ACROSS THE SRN HIGH PLAINS THROUGH THURSDAY MORNING. DYNAMIC FORCING ACCOMPANYING THE EWD TRANSITION OF THE LARGE SCALE TROUGH WILL ENHANCE DEEP-LAYER FRONTOGENESIS AND LIFT ALONG A STRONG COLD FRONT FORECAST TO SURGE INTO THE WRN GREAT LAKES...MIDWEST...AND SRN PLAINS REGIONS THROUGH LATE TOMORROW NIGHT. ...NRN TX...ERN OK...OZARKS... MOIST AXIS HAS BECOME WELL ESTABLISHED ACROSS THE SRN PLAINS GIVEN PERSISTENT SLY LOW LEVEL FLOW AND PASSAGE OF DEAMPLIFYING SHORT WAVE TROUGH EARLIER TODAY. CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT WILL MAINTAIN LOW TO MID 60S F DEWPOINTS ACROSS THE SRN PLAINS AND SUPPORT MUCAPES CLIMBING TO NEAR 1000 J/KG PERHAPS AS EARLY AS WEDNESDAY MORNING. LATEST NAM AND GFS ARE TRENDING A BIT FASTER WITH COLD FRONTAL PASSAGE ACROSS NWRN/CNTRL OK BY WEDNESDAY AFTERNOON BIT THERE ARE DIFFERENCES IN CONVECTIVE INITIATION NEAR THE FRONT WITH THE GFS SUGGESTING AN EARLIER START TO MORE VIGOROUS DEEP CONVECTION ACROSS OK/NORTH TX BY AFTERNOON. GIVEN FAVORABLE LARGE SCALE SUPPORT IN THE FORM OF INCREASINGLY DIFFLUENT/DIVERGENT FLOW IN RIGHT ENTRANCE REGION OF INTENSIFYING UPPER JET...AND GENERALLY WEAK CAP ACROSS MOIST AND UNSTABLE PRE-FRONTAL AIR MASS...TSTMS SHOULD INCREASE THROUGH THE AFTERNOON. SHEAR ACROSS THE REGION WILL STRENGTHEN THROUGH THE DAY AND SUPPORT ORGANIZED AND PERSISTENT UPDRAFTS CAPABLE OF HAIL AND DAMAGING WINDS. A SUPERCELL TORNADO AND/OR VERY LARGE HAIL THREAT APPEARS POSSIBLE ACROSS THE RED RIVER REGION DURING THE AFTERNOON OR EARLY EVENING WHERE THERMAL TROUGH/COLD FRONT INTERSECTION MAY ENHANCE LOW LEVEL MESOSCALE FORCING. BULK OF CONVECTION ACROSS THE REGION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING SEWD ACROSS THE AREA THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE ACROSS PARTS OF NERN OK AND NCNTRL TX INTO THE LATER EVENING. ...NRN MO TO IL... MOIST AXIS WILL BE NARROW AND CAPE WILL BE WEAKER FROM THE OZARKS NEWD ACROSS THE MS VALLEY INTO WRN IL. NONETHELESS...LIFT ALONG THE FRONT...AND INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES...SUGGEST SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT OF EITHER MARGINALLY SEVERE HAIL AND/OR HIGH WINDS. GIVEN CONSENSUS IN AVAILABLE GUIDANCE THAT A NARROW CORRIDOR OF AT LEAST 500 J/KG MUCAPE WILL BE AVAILABLE TO CONVECTION DEVELOPING NEAR THE ADVANCING FRONT...AND STRONG SIGNAL THAT VIGOROUS CONVECTIVE DEVELOPMENT WILL OCCUR WITHIN HIGH MOMENTUM REGIME...NEWD EXTENSION OF THE HIGHER SEVERE PROBABILITIES APPEARS PRUDENT AT THIS TIME. ..CARBIN.. 11/28/2006  From swody2 at goshenarc.org Wed Nov 29 05:28:36 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 00:28:36 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290530 SWODY2 SPC AC 290528 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST TUE NOV 28 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... ...SYNOPSIS... INTENSIFICATION OF SRN STREAM TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS IT TRANSLATES EWD THROUGH THE SRN PLAINS...PRIOR TO BECOMING NEGATIVELY TILTED AND EJECTING MORE NEWD INTO THE MID MS AND LOWER OH VALLEYS BY FRIDAY MORNING. AN ACCOMPANYING BELT OF STRONG /80-100 KT AT 500 MB/ MID-LEVEL FLOW WILL PROPAGATE THROUGH THE TROUGH BASE...SPREADING THROUGH THE ARKLATEX...MID SOUTH AND LOWER MS VALLEY REGIONS. IN THE LOW-LEVELS...COLD FRONT INITIALLY EXTENDING FROM CNTRL LOWER MI SWWD INTO SERN TX WILL RAPIDLY PUSH SEWD/EWD WITH SECONDARY CYCLOGENESIS FORECAST OVER THE LOWER MS VALLEY THURSDAY. DIFFERENCES EXIST IN LATEST SHORT RANGE MODEL GUIDANCE WITH REGARD TO THE TRACK AND STRENGTH OF THIS FEATURE...BUT IN GENERAL IT IS FORECAST TO DEVELOP NEWD ALONG COLD FRONT INTO THE UPPER OH VALLEY BY FRIDAY MORNING. ...S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... LARGE-SCALE PATTERN CONTINUES TO INDICATE THE POTENTIAL FOR A LOW INSTABILITY - HIGH SHEAR SERIAL-TYPE WIND EVENT ACROSS THE REGION THURSDAY INTO THURSDAY NIGHT. 29/00Z OBSERVED SOUNDINGS...CURRENT SURFACE OBSERVATIONS AND GOES SOUNDER PW LOOP ALL INDICATE A FAIRLY RAPID RETURN OF LOW-LEVEL MOISTURE THROUGH THE SABINE AND LOWER MS RIVER VALLEYS NWD INTO THE MID SOUTH AND WRN TN VALLEY WITH 60F DEWPOINTS TO LIT AND THE MS DELTA. SWLY LLJ WILL BE MAINTAINED AHEAD OF EVOLVING UPPER SYSTEM...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD WITH 60F DEWPOINTS INTO KY...AND MID/UPPER 60S INTO THE LOWER MS VALLEY BY THURSDAY AFTERNOON. LATEST MODEL GUIDANCE CONTINUES TO INDICATE ONLY MARGINAL INSTABILITY /MUCAPES OF 200-600 J PER KG/ AHEAD OF SURFACE FRONT THURSDAY...LARGELY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE THE MARGINAL INSTABILITY...INCREASED LARGE-SCALE FORCING...SLAB ASCENT ALONG COLD FRONT AND STRONG VERTICAL SHEAR ALL SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD INTO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. THE STRENGTH OF THE AMBIENT WIND FIELDS WILL SUPPORT STORM MOTIONS OF 45-50+KT WITH THE POTENTIAL FOR CORRIDORS OF WIND DAMAGE. LOW-TOPPED SUPERCELLS WILL ALSO BE POSSIBLE...BOTH EMBEDDED IN LINE OR FORMING IN MORE DISCRETE FASHION AHEAD OF PRIMARY CONVECTIVE SYSTEM. GIVEN THE LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR...THE THREAT FOR ISOLATED TORNADOES WILL EXIST. THIS IS ESPECIALLY THE CASE INVOF DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. THIS CONVECTIVE LINE WILL RAPIDLY SHIFT EWD THROUGH THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THURSDAY NIGHT WITH A CONTINUING THREAT OF DAMAGING WINDS AND PERHAPS A FEW TORNADOES. ..MEAD.. 11/29/2006  From swody2 at goshenarc.org Wed Nov 29 07:05:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 02:05:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290707 SWODY2 SPC AC 290528 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 PM CST TUE NOV 28 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... ...SYNOPSIS... INTENSIFICATION OF SRN STREAM TROUGH IS FORECAST DURING THE DAY TWO PERIOD AS IT TRANSLATES EWD THROUGH THE SRN PLAINS...PRIOR TO BECOMING NEGATIVELY TILTED AND EJECTING MORE NEWD INTO THE MID MS AND LOWER OH VALLEYS BY FRIDAY MORNING. AN ACCOMPANYING BELT OF STRONG /80-100 KT AT 500 MB/ MID-LEVEL FLOW WILL PROPAGATE THROUGH THE TROUGH BASE...SPREADING THROUGH THE ARKLATEX...MID SOUTH AND LOWER MS VALLEY REGIONS. IN THE LOW-LEVELS...COLD FRONT INITIALLY EXTENDING FROM CNTRL LOWER MI SWWD INTO SERN TX WILL RAPIDLY PUSH SEWD/EWD WITH SECONDARY CYCLOGENESIS FORECAST OVER THE LOWER MS VALLEY THURSDAY. DIFFERENCES EXIST IN LATEST SHORT RANGE MODEL GUIDANCE WITH REGARD TO THE TRACK AND STRENGTH OF THIS FEATURE...BUT IN GENERAL IT IS FORECAST TO DEVELOP NEWD ALONG COLD FRONT INTO THE UPPER OH VALLEY BY FRIDAY MORNING. ...S-CNTRL OH VALLEY SWD INTO THE LOWER MS VALLEY AND CNTRL GULF COAST... LARGE-SCALE PATTERN CONTINUES TO INDICATE THE POTENTIAL FOR A LOW INSTABILITY - HIGH SHEAR SERIAL-TYPE WIND EVENT ACROSS THE REGION THURSDAY INTO THURSDAY NIGHT. 29/00Z OBSERVED SOUNDINGS...CURRENT SURFACE OBSERVATIONS AND GOES SOUNDER PW LOOP ALL INDICATE A FAIRLY RAPID RETURN OF LOW-LEVEL MOISTURE THROUGH THE SABINE AND LOWER MS RIVER VALLEYS NWD INTO THE MID SOUTH AND WRN TN VALLEY WITH 60F DEWPOINTS TO LIT AND THE MS DELTA. SWLY LLJ WILL BE MAINTAINED AHEAD OF EVOLVING UPPER SYSTEM...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD WITH 60F DEWPOINTS INTO KY...AND MID/UPPER 60S INTO THE LOWER MS VALLEY BY THURSDAY AFTERNOON. LATEST MODEL GUIDANCE CONTINUES TO INDICATE ONLY MARGINAL INSTABILITY /MUCAPES OF 200-600 J PER KG/ AHEAD OF SURFACE FRONT THURSDAY...LARGELY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE THE MARGINAL INSTABILITY...INCREASED LARGE-SCALE FORCING...SLAB ASCENT ALONG COLD FRONT AND STRONG VERTICAL SHEAR ALL SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD INTO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. THE STRENGTH OF THE AMBIENT WIND FIELDS WILL SUPPORT STORM MOTIONS OF 45-50+KT WITH THE POTENTIAL FOR CORRIDORS OF WIND DAMAGE. LOW-TOPPED SUPERCELLS WILL ALSO BE POSSIBLE...BOTH EMBEDDED IN LINE OR FORMING IN MORE DISCRETE FASHION AHEAD OF PRIMARY CONVECTIVE SYSTEM. GIVEN THE LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR...THE THREAT FOR ISOLATED TORNADOES WILL EXIST. THIS IS ESPECIALLY THE CASE INVOF DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. THIS CONVECTIVE LINE WILL RAPIDLY SHIFT EWD THROUGH THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THURSDAY NIGHT WITH A CONTINUING THREAT OF DAMAGING WINDS AND PERHAPS A FEW TORNADOES. ..MEAD.. 11/29/2006  From swody2 at goshenarc.org Wed Nov 29 17:28:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 29 Nov 2006 12:28:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291731 SWODY2 SPC AC 291729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CST WED NOV 29 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST ACROSS THE MS/TN AND LOWER OH VALLEYS TO SRN APPALACHIANS... ...SYNOPSIS... POWERFUL AND PROGRESSIVE SHORT WAVE IMPULSE WILL INTENSIFY THROUGH THE DAY TWO PERIOD ACROSS THE SRN PLAINS BEFORE TAKING ON A NEGATIVE TILT AND EJECTING NEWD FROM THE OZARKS TO THE OH VALLEY BY FRIDAY. IN ADDITION TO SIGNIFICANT 12H 500MB HEIGHT FALLS OF AROUND 300M ACROSS THE MO BOOTHEEL/SRN IL...AN INTENSE MID LEVEL JET OF 100-120KT WILL ROTATE THROUGH THE BASE OF THE EJECTING SHORT WAVE TROUGH...MOVING NEWD FROM THE ARKLATEX TO THE LOWER OH VALLEY AREA THROUGH THURSDAY NIGHT. VERY STRONG DYNAMIC AND KINEMATIC FORCING WILL INDUCE SURFACE CYCLOGENESIS ALONG AN ASSOCIATED COLD FRONT ACROSS ERN AR BY THURSDAY AFTERNOON. THE INTENSIFYING SURFACE CYCLONE IS FORECAST TO TRACK NEWD FROM ERN AR TO OH AS POTENT COLD FRONT SWEEPS EWD FROM THE MS VALLEY TO THE APPALACHIANS THROUGH EARLY FRIDAY. LARGE-SCALE PATTERN AS FORECAST BY NAM AND GFS HAS AN ANALOG IN 1996 NOVEMBER 7-8 EVENT WHICH RESULTED IN A SWATH OF SEVERE CONVECTIVE WIND EVENTS FROM LA TO OH. THIS ANALOG WAS ALSO A STRONGLY DYNAMIC...LOW CAPE/HIGH SHEAR...SEVERE WEATHER EPISODE. ...CNTRL GULF COAST ACROSS THE MS/TN AND LOWER OH VALLEYS...TO SRN APPALACHIANS... LATEST OBSERVATIONS INDICATE SURFACE DEWPOINTS INCREASING AND SPREADING NNEWD FROM THE GULF ACROSS THE LOWER MS RIVER VALLEY AND INTO THE LOWER OH VALLEY. WITH SWLY LLJ BEING MAINTAINED IN ADVANCE OF THE APPROACHING UPPER TROUGH...EXPECT AN INCREASINGLY MOIST BOUNDARY LAYER TO EXPAND NWD AND EWD ACROSS THE MS/TN AND OH VALLEYS THROUGH EARLY THURSDAY. HOWEVER...LATEST GUIDANCE CONTINUES TO INDICATE THAT ONLY MARGINAL INSTABILITY /MUCAPES OF 200-500 J PER KG/ WILL DEVELOP AHEAD OF THE INTENSE COLD FRONT ON THURSDAY DUE TO WEAK LOW TO MID-LEVEL LAPSE RATES. DESPITE INSTABILITY CONSTRAINTS...INCREASINGLY STRONG LARGE-SCALE FORCING AND SLAB ASCENT ACROSS COLD FRONT SHOULD CONTRIBUTE TO THE INTENSIFICATION OF A LOW-TOPPED CONVECTIVE LINE BY AFTERNOON FROM THE CONFLUENCE OF THE MS/OH RIVERS SWWD TO ERN AR AND CNTRL LA. PRIMARY CONVECTIVE MODE IS EXPECTED TO BE LINEAR WITH EMBEDDED LEWP/BOW STRUCTURES. STRENGTH OF THE DEEP-LAYER WIND FIELDS WILL SUPPORT STORM MOTIONS OF 50+KT WITH THE POTENTIAL FOR DAMAGING WINDS FROM A FAST MOVING LOW-TOPPED SQUALL LINE. GIVEN MAGNITUDE OF SHEAR AND FORCING...A FEW LOW-TOPPED SUPERCELLS ALSO APPEAR POSSIBLE...PERHAPS EMBEDDED WITHIN THE LINE...OR FORMING AS MORE DISCRETE STORMS AHEAD OF THE LINE. LOW LCL HEIGHTS AND STRONG LOW-LEVEL SHEAR IN THE WARM SECTOR SHOULD SUPPORT SOME THREAT FOR TORNADOES. POTENTIAL FOR TORNADOES MAY BE ESPECIALLY ENHANCED NEAR THE DEEPENING SURFACE CYCLONE WHERE LOW LEVEL SHEAR/FORCING WILL BE LOCALLY MORE INTENSE. SQUALL LINE...WITH THE POSSIBILITY OF LIMITED CG LIGHTNING DUE TO LOW CAPE...WILL SHIFT EAST ACROSS THE MS VALLEY AND INTO THE SRN OH AND TN VALLEYS...AS WELL AS THE CNTRL GULF COAST THROUGH THURSDAY NIGHT. WITH CONTINUING INTENSIFICATION OF THE DEEP-LAYER CYCLONE AND CONTINUED SHARPENING OF THE FRONTAL ZONE...THE THREAT OF DAMAGING WINDS AND ISOLATED TORNADOES MAY PERSIST INTO EARLY FRIDAY AS THE FRONT/SQUALL LINE MOVES EAST TOWARD THE UPPER OH VALLEY AND EXTENDS SWD TO THE SRN APPALACHIANS. ..CARBIN.. 11/29/2006  From swody2 at goshenarc.org Thu Nov 30 05:36:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 30 Nov 2006 00:36:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300538 SWODY2 SPC AC 300536 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 PM CST WED NOV 29 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER OH VALLEY EWD THROUGH THE MIDDLE ATLANTIC STATES AND NEW ENGLAND... ...SYNOPSIS... INTENSE...NEGATIVELY-TILTED SHORT WAVE TROUGH INITIALLY OVER THE LOWER OH VALLEY WILL RAPIDLY TRANSLATE NEWD THROUGH THE ST. LAWRENCE VALLEY WITH 250-300M HEIGHT FALLS SPREADING NEWD THROUGH THE MIDDLE/UPPER OH VALLEY AND NERN STATES. IN THE LOW-LEVELS... DEEPENING SURFACE LOW WILL DEVELOP FROM THE MIDDLE OH VALLEY NEWD THROUGH THE UPPER GREAT LAKES INTO THE GULF OF ST. LAWRENCE WITH TRAILING COLD FRONT SWEEPING EWD THROUGH THE APPALACHIANS...PIEDMONT AND COASTAL PLAIN. ...UPPER OH VALLEY EWD THROUGH THE MIDDLE ATLANTIC STATES AND NEW ENGLAND... LARGE-SCALE PATTERN APPEARS SUPPORTIVE OF A LOW INSTABILITY/HIGH SHEAR SERIAL-TYPE DERECHO EVENT OVER PARTS OF THE REGION FRIDAY INTO FRIDAY NIGHT. STRONGLY FORCED...LOW-TOPPED CONVECTIVE LINE IS EXPECTED TO BE ONGOING FRIDAY MORNING FROM VICINITY OF SURFACE LOW OVER IND/WRN OH SWD ALONG COLD FRONT INTO MIDDLE TN...DRIVEN BY INTENSE LARGE-SCALE FORCING ASSOCIATED WITH EJECTING UPPER WAVE. SSWLY 50-60KT LLJ INITIALLY FROM AL/GA INTO THE UPPER OH VALLEY WILL SHIFT EWD THROUGH THE DAY...TRANSPORTING AN INCREASINGLY MOIST BOUNDARY LAYER NWD INTO THE REGION. THIS INCREASE IN MOISTURE COUPLED WITH STEEPENING MID-LEVEL LAPSE RATES ARE EXPECTED TO CONTRIBUTE TO DESTABILIZATION OF PRE-FRONTAL AIR MASS WITH STRONGEST INSTABILITY /MUCAPES APPROACHING 500-900 J PER KG/ DEVELOPING ACROSS PA AND NY FRIDAY AFTERNOON. 100-120KT MID-LEVEL JET STREAK ALONG IMMEDIATE DOWNSTREAM POSITION OF TROUGH BASE AND 60-70KT WINDS AS LOW AS 1-2 KM AGL /PER FORECAST SOUNDINGS/ INDICATE THAT EVEN WEAK CONVECTIVE DOWNDRAFTS WILL BE CAPABLE OF DAMAGING WINDS. AS SUCH...EXPECT THAT THE WIND DAMAGING THREAT WILL EXIST FROM THE ONSET OF THE FORECAST OVER OH SWD INTO KY/WV...WITH THIS THREAT LIKELY INCREASING CONSIDERABLY BY AFTERNOON OVER NY/PA AS CONVECTIVE LINE ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS. EMBEDDED BOWING/LEWP STRUCTURES WILL BE CAPABLE OF CORRIDORS OF DAMAGING WINDS...ESPECIALLY GIVEN THE FORECAST 50-60+KT STORM MOTIONS. THE STRONGER INSTABILITY OVER NY/PA MAY EVEN SUPPORT EMBEDDED SUPERCELLS WITH A THREAT OF ISOLATED TORNADOES GIVEN THE STRONG LOW-LEVEL SHEAR AND LOW LCL HEIGHTS. EXPECT THIS STRONGLY FORCED...FAST MOVING CONVECTIVE LINE TO SWEEP THROUGH THE HUDSON VALLEY AND DE RIVER VALLEY LATE FRIDAY AFTERNOON OR EARLY EVENING...AND MUCH OF NEW ENGLAND FRIDAY NIGHT. WIDESPREAD DAMAGING WINDS WILL REMAIN POSSIBLE THROUGH AT LEAST THE EVENING HOURS AS BOUNDARY LAYER REMAINS SOMEWHAT TURBULENTLY MIXED. SHOULD FUTURE OBSERVATIONS AND/OR MODEL GUIDANCE INDICATE MORE INSTABILITY THAN IS CURRENTLY FORECAST...AN UPGRADE TO MODERATE RISK MAY BECOME NECESSARY. ..MEAD.. 11/30/2006  From swody2 at goshenarc.org Thu Nov 30 17:25:55 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 30 Nov 2006 12:25:55 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301727 SWODY2 SPC AC 301725 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CST THU NOV 30 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH/TN VLYS NEWD INTO THE MID-ATLANTIC REGION AND NEW ENGLAND... ...OH VLY/CNTRL APPALACHIANS NEWD TO NEW ENGLAND/MID-ATLANTIC... SYNOPTIC REGIME APPEARS SUPPORTIVE OF A LOW INSTABILITY/HIGH SHEAR SERIAL-TYPE DERECHO EVENT ACROSS PARTS OF THE REGION FRI AND FRI NIGHT. POTENTIAL EXISTS FOR WIDESPREAD DAMAGING WINDS AND ISOLD TORNADOES...PARTICULARLY ACROSS CNTRL/ERN PA...PARTS OF MD AND SRN NY. POWERFUL NEGATIVE-TILT UPPER LOW AND ASSOCD 120+ KT H5 JET WILL TRANSLATE FROM THE LWR OH VLY EARLY FRI TO SRN QUE BY 12Z SAT. IMPRESSIVE LARGE SCALE HEIGHT FALLS OF 150-300 METERS WILL SPREAD NEWD...WITH THE STRONGEST FALLS SHIFTING THROUGH THE OH VLY INTO PA/NY DURING FRI AFTN/EVE. AT THE SFC...PRIMARY OCCLUSION WILL TRAVEL FROM NRN IND INTO SWRN ONTARIO BY FRI EVE. NEW CYCLOGENESIS IS LIKELY OVER NCNTRL PA OR SCNTRL NY FRI MORNING...WITH THE LOW THEN MOVING INTO NWRN MAINE/SRN QUE BY 12Z SATURDAY. A TRAILING COLD FRONT WILL SWEEP EWD ACROSS THE APPALACHIANS DURING FRI AFTN/EVE...THEN OFFSHORE BY EARLY SATURDAY MORNING. A STRONGLY FORCED...LOW-TOPPED CONVECTIVE LINE IS EXPECTED TO BE ONGOING EARLY FRI MORNING FROM THE OCCLUDED LOW OVER IND SWD INTO THE MID-TN VLY. AHEAD OF THIS LINE...A STRONG SSWLY LLJ IN EXCESS OF 50-60 KTS WILL SHIFT EWD FROM THE OH/TN VLYS. AS A RESULT...SUBSTANTIAL BOUNDARY LAYER MOISTURE...NOW EVIDENT AS SFC DEW POINTS AOA 60 DEG F OVER THE SERN STATES...WILL ADVECT NWD. GIVEN STEEPENING MID-LEVEL LAPSE RATES SPREADING EWD ATOP THIS MOIST AXIS...MODEST DESTABILIZATION IS EXPECTED AHEAD OF THE FRONT. STRONGEST INSTABILITY /MUCAPES OF A FEW HUNDRED J/KG/ SHOULD DEVELOP ACROSS PARTS OF PA AND NY DURING PEAK HEATING FRI. AS A RESULT...TSTMS WILL LIKELY INTENSIFY OVER THESE AREAS AFTER 18Z. FORECAST SOUNDINGS INDICATE THAT TSTMS WILL LIKELY BECOME SFC-BASED...ESPECIALLY ALONG AND IMMEDIATELY EAST OF THE SPINE OF THE APPALACHIANS AND THEN RAPIDLY TRANSLATE ENEWD INTO SCNTRL NY/ERN PA/NRN MD BY FRI EVE. AMBIENT WINDS WILL BE QUITE STRONG WITH THIS SYSTEM WITH 70 KTS JUST OFF THE SURFACE...INCREASING CONFIDENCE THAT CONVECTIVE DOWNDRAFTS WILL BE CAPABLE OF DAMAGING WINDS. WHILE THE WIND DAMAGE THREAT WILL EXIST FROM THE ONSET OF THE FCST PERIOD OVER THE MID-OH VLY SWD INTO ERN PORTIONS OF KY/TN...THE THREAT WILL INCREASE AND PEAK BY AFTN OVER NY/PA AND NRN MD AS THE LINE ENCOUNTERS THE MORE SUBSTANTIAL INSTABILITY/LOW-LEVEL LAPSE RATES. EMBEDDED BOWING/LEWP STRUCTURES WILL BE CAPABLE OF CORRIDORS OF DAMAGING WINDS...ESPECIALLY GIVEN THE FORECAST 50-60+KT STORM MOTIONS. MOREOVER...THE STRONGER INSTABILITY OVER NY/PA MAY EVEN SUPPORT SUPERCELLS...BOTH EMBEDDED WITHIN THE LINE AND POSSIBLY IN THE WARM SECTOR...WITH A THREAT OF ISOLATED TORNADOES GIVEN THE STRONG LOW-LEVEL SHEAR AND LOW LCL HEIGHTS. THIS STRONGLY FORCED...FAST MOVING CONVECTIVE LINE WILL SWEEP THROUGH THE HUDSON VALLEY AND DE RIVER VLY LATE FRI AFTN/EVE AND MUCH OF NEW ENGLAND FRI NIGHT WITH ATTENDANT DAMAGING WINDS. NRN EXTENT OF THE DAMAGING WIND THREAT SHOULD BE MODULATED BY AN E-W FRONT THAT SHOULD REMAIN ACROSS AT LEAST SRN MAINE OVERNIGHT. ..RACY.. 11/30/2006