From swody1 at goshenarc.org Sat Nov 4 05:44:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 00:44:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040546 SWODY1 SPC AC 040544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST FRI NOV 03 2006 VALID 041200Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... EMBEDDED IN A RELATIVELY ZONAL UPPER LEVEL PATTERN ACROSS THE CONUS...A PROGRESSIVE SHORTWAVE TROUGH OVER THE GREAT BASIN EARLY THIS MORNING WILL MOVE EWD INTO THE CENTRAL/SRN PLAINS BY THE TONIGHT. STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THIS SYSTEM COMBINED WITH HEATING AND OROGRAPHIC LIFT MAY SUPPORT A FEW TSTMS OVER PORTIONS OF THE SRN ROCKIES IN THE AFTERNOON. AHEAD OF THIS SYSTEM...MODIFIED RETURN FLOW WILL SUPPORT LOW LEVEL MOISTURE INCREASE OVER THE SRN PLAINS. ALONG WITH LIFT ASSOCIATED WITH THE APPROACHING SYSTEM....THERE WILL BE THE POTENTIAL FOR ELEVATED TSTMS OVERNIGHT ACROSS PORTIONS OF THE AREA. THE REMAINDER OF THE ERN HALF OF THE NATION WILL REMAIN STABLE UNDER THE INFLUENCE OF A BROAD AREA OF SFC HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE OVER THE FLA KEYS WHERE A DIFFUSE FRONTAL BOUNDARY AND A PLUME OF MID/HIGH LEVEL TROPICAL MOISTURE WILL REMAIN INVOF THE AREA...SUPPORTING ISOLATED TSTMS GENERALLY BEFORE 00Z. ...PORTIONS OF OK/WRN AR AND SRN MO... ELEVATED MOISTURE /850 DEWPT AROUND 8 DEG C NOTED ON THE 04/00Z DRT SOUNDING AND 700 DEWPT AROUND 0 DEG C ON THE 04/00Z MAF SOUNDING/ WILL ADVECT/ISENTROPICALLY LIFT INTO THE REGION LATER THIS AFTERNOON AND OVERNIGHT ON THE NOSE OF A MODERATELY STRONG 40 KT LOW LEVEL JET. WITH THE APPROACH OF THE SHORTWAVE...MID LEVEL TEMPERATURES WILL COOL AIDING IN STEEPENING MID LEVEL LAPSE RATES. IN ADDITION...INCREASING MID LEVEL VERTICAL MOTION WILL OCCUR OVER THE AREA OVERNIGHT AS A RESULT THE RIGHT ENTRANCE OF A 100 KT UPPER LEVEL SPEED MAX MOVING ACROSS THE REGION. THE COMBINATION OF ALL THESE INGREDIENTS SHOULD BE SUFFICIENT TO SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS FROM PORTIONS OF CENTRAL/ERN OK INTO SRN MO AND WRN AR GENERALLY AFTER 03Z. MARGINAL INSTABILITY /MUCAPES LESS THAN 250 J/KG/ SHOULD PRECLUDE AN ELEVATED SVR HAIL THREAT. ..CROSBIE/WEISS.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 12:41:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 07:41:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041243 SWODY1 SPC AC 041240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST SAT NOV 04 2006 VALID 041300Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...KS/OK/TX/MO/AR... WATER VAPOR LOOP SHOWS BROAD/FAST ZONAL FLOW PATTERN ACROSS MOST OF THE NATION THIS MORNING. ONE UPPER SHORTWAVE TROUGH CURRENTLY OVER NV/UT WILL TRACK EASTWARD ACROSS THE ROCKIES AND INTO THE CENTRAL HIGH PLAINS BY SUNDAY MORNING. SOUTHWESTERLY LOW LEVEL JET WILL BE SUSTAINED THROUGHOUT THE FORECAST PERIOD FROM CENTRAL TX...ACROSS MO...INTO THE WESTERN GREAT LAKES REGION. TRAJECTORIES WILL DRAW MODEST LOW LEVEL MOISTURE /MOSTLY ELEVATED ABOVE STABLE BOUNDARY LAYER/ INTO PARTS OF OK/KS/MO/AR. MODEL FORECAST SOUNDINGS ACROSS THIS AREA SHOW A PLUME OF MARGINAL ELEVATED INSTABILITY DEVELOPING AFTER 00Z IN REGION OF LOW LEVEL JET AXIS. INCREASING FORCING FOR LARGE SCALE ASCENT DURING THIS PERIOD IS EXPECTED TO RESULT IN AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS FROM NORTH CENTRAL TX INTO SOUTHWEST MO. LACK OF SUFFICIENT INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ...CO... STEEP LOW/MID LEVEL LAPSE RATES ARE FORECAST TO DEVELOP THIS AFTERNOON OVER THE HIGHER TERRAIN OF SOUTHERN CO AS UPPER SHORTWAVE TROUGH APPROACHES AREA. 500MB TEMPERATURES AROUND -18C COUPLED WITH POCKETS OF STRONG DAYTIME HEATING ARE LIKELY TO RESULT IN SUFFICIENT INSTABILITY FOR ISOLATED THUNDERSTORMS. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND DIMINISH RAPIDLY AFTER SUNSET. NO SEVERE STORMS ARE FORECAST. ...SOUTH FL... PLUME OF SUBTROPICAL MOISTURE REMAINS OVER THE FL STRAITS THIS MORNING. THIS WILL LIKELY RESULT IN SCATTERED CONVECTION THROUGHOUT THE DAY ACROSS THE SOUTHERN HALF OF THE FL PENINSULA. FAR SOUTH FL AND THE KEYS MAY SEE SUFFICIENTLY DEEP INSTABILITY FOR ISOLATED LIGHTNING STRIKES IN STRONGER CELLS THIS AFTERNOON. ..HART/CROSBIE.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 16:19:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 11:19:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041622 SWODY1 SPC AC 041620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST SAT NOV 04 2006 VALID 041630Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS... MID-LEVEL SHORTWAVE TROUGH OVER UT WILL TRACK E/SEWD TOWARDS THE OK/TX PANHANDLES BY SUNDAY MORNING. A 30-40 KT S/SWLY LOW-LEVEL JET WILL BE SUSTAINED AHEAD OF THIS TROUGH FROM CNTRL TX INTO ERN OK. MODEST LOW-LEVEL MOISTURE /AS SAMPLED BY 12Z DRT SOUNDING/ WILL BE DRAWN N/NEWD. IN ADDITION...MID-LEVEL LAPSE RATES AROUND 7 C/KM SHOULD BE ADVECTED EWD ATOP THE LOW-LEVEL MOIST AXIS ACROSS WRN/CNTRL OK AND N-CNTRL TX. MODEL FORECAST SOUNDINGS INDICATE MARGINAL ELEVATED INSTABILITY WITH MUCAPES OF 500 TO 1000 J/KG IN THIS REGION LATER TONIGHT. AS LARGE-SCALE FORCING INCREASES WITH THE SHORTWAVE APPROACHING...ISOLATED TO SCATTERED TSTMS SHOULD DEVELOP...ESPECIALLY BY THE 09-12Z TIME FRAME. A FEW STORMS MAY CONTAIN SOME MARGINAL HAIL. FURTHER E...OTHER TSTMS SHOULD DEVELOP IN THE LOW-LEVEL MOIST AXIS...MAINLY AFTER DARK. ...SRN CO... LOW-LEVEL LAPSE RATES WILL STEEPEN THROUGH THIS AFTERNOON AS DAYTIME HEATING CONTINUES. COOL MID-LEVEL TEMPS /AROUND -18C AT 500 MB/ IN ASSOCIATION WITH THE UT SHORTWAVE SHOULD RESULT IN WEAK INSTABILITY FOR A FEW TSTMS. CONVECTION SHOULD BE DIURNAL IN NATURE AND DIMINISH AFTER SUNSET. ..GRAMS/THOMPSON.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 19:54:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 14:54:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041956 SWODY1 SPC AC 041953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0153 PM CST SAT NOV 04 2006 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS INTO OZARK PLATEAU... VISIBLE SATELLITE LOOP AND SURFACE OBSERVATIONAL DATA TRENDS INDICATE LOW-LEVEL MOISTURE INCREASING NWD FROM THE NWRN GULF OF MEXICO INTO NWRN TX...DOWNSTREAM FROM SHORT WAVE TROUGH MOVING INTO THE SRN HIGH PLAINS. THIS SHORTWAVE TROUGH WILL CONTINUE EWD OVERNIGHT...PROMOTING NOCTURNAL LLJ DEVELOPMENT FROM THE LOWER RIO GRANDE VALLEY INTO ERN OK. ELEVATED TSTMS ARE FORECAST TO BECOMING INCREASINGLY LIKELY OVERNIGHT ALONG THIS LLJ AXIS WHERE WAA/ISENTROPIC UPGLIDE WILL BE COLOCATED WITH THE INCREASE IN MOISTURE /MOST NOTABLY IN THE 850-800 MB LAYER/ AND STEEPENING MID-LEVEL LAPSE RATES. SOME SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT NO SEVERE WEATHER IS ANTICIPATED. ...SWRN TX... VISIBLE SATELLITE AND RUC OBJECTIVE FIELDS INDICATE BOUNDARY LAYER BECOMING PROGRESSIVELY MORE BUOYANT THIS AFTERNOON OWING TO DIABATIC HEATING AND MODEST LOW-LEVEL MOISTURE WITH SBCAPES OF 1000-1500 J/KG AND LITTLE OR NO CONVECTIVE INHIBITION. LARGE SCALE FORCING FOR ASCENT IS EXPECTED TO REMAIN QUITE WEAK...HOWEVER SUBTLE OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE ISOLATED TSTMS THIS AFTERNOON INTO EVENING ALONG THE HIGHER TERRAIN. ..MEAD.. 11/04/2006  From swody1 at goshenarc.org Sun Nov 5 01:01:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 20:01:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050103 SWODY1 SPC AC 050100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 PM CST SAT NOV 04 2006 VALID 050100Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID/UPPER LEVELS...NEARLY ZONAL MEAN FLOW PATTERN IS EVIDENT OVER MOST OF CONUS...DISTORTED PRIMARILY BY SHORTWAVE TROUGH ANALYZED FROM CENTRAL HIGH PLAINS SWWD ACROSS SWRN NM. THIS TROUGH SHOULD DRIFT EWD OVERNIGHT. UPSTREAM...MID-UPPER LEVEL SHORTWAVE TROUGH -- EVIDENT IN MOISTURE CHANNEL IMAGERY FROM 130-133W OFFSHORE WA/BC -- IS FCST TO MOVE INLAND BY APPROXIMATELY 06Z. AT SFC...WEAK QUASISTATIONARY FRONT AND CONFLUENT LINE WAS ANALYZED FROM NW OK SWWD ACROSS CENTRAL TX PANHANDLE...THROUGH LOW INVOF TCC...THEN BECOMING DIFFUSE FARTHER WSW. DRYLINE WAS ANALYZED FROM NRN COAHUILA NWD BETWEEN MAF-INK THEN NNEWD ACROSS CDS AREA...BECOMING DIFFUSE OVER WRN OK WHERE ONLY WEAK MOISTURE HAS RETURNED TO ITS E. LOW CLOUD TRENDS AND GPS-PW DATA INDICATE BOUNDARY LAYER DRYLINE HAS BEEN QUASISTATIONARY SE OF REGION DURING PAST FEW HOURS...HOWEVER MORE INTENSE PRESSURE/HEIGHT FALLS ARE EXPECTED IN LOW LEVELS OVERNIGHT THAT SHOULD SHIFT W/NW EDGE OF MOIST PLUME AT LEAST INTO POSITION OF QUASISTATIONARY FRONT OVER PANHANDLE...AND WWD TO VICINITY NM BORDER AND DAVIS MOUNTAINS FARTHER S. ...OZARKS TO SRN HIGH PLAINS... AHEAD OF AFOREMENTIONED SHORTWAVE TROUGH...ELEVATED LOW LEVEL WAA REGIME WILL PERSIST THROUGH TONIGHT...ACCOMPANIED BY MOISTENING/STRENGTHENING LLJ FROM NRN COAHUILA NWD THEN NEWD ACROSS W-CENTRAL/N-CENTRAL TX AND ERN OK. TWO ASSOCIATED AREAS OF GEN TSTM POTENTIAL EXIST FOR REMAINDER PERIOD...WITH JUST ENOUGH UNCERTAINTY IN POSSIBLE SPATIAL OVERLAP THAT THEY STILL FORM ONE COMPOSITE AREA ON 01Z-12Z GRAPHIC DEPICTION. 1. CONVECTION IS INCREASING IN COVERAGE AND INTENSITY ACROSS SERN KS...NWRN AR...NERN OK AND SWRN MO ATTM. THIS ACTIVITY CORRESPONDS TO LEADING PORTION OF FAVORABLE LOW LEVEL MOIST ADVECTION ABOVE SFC...AND ISENTROPIC ASCENT TO LFC. ELEVATED MUCAPES 100-200 J/KG ALREADY EVIDENT IN SGF RAOB WERE UNDERFCST BY LATEST RUNS OF BOTH ETA AND RUC...INDICATING THESE MODELS MAY SIMILARLY UNDERFCST SIZE/COVERAGE OF CONVECTIVE AREA THIS EVENING UNTIL LATEST RAOB DATA IS INPUT. PRIND ACTIVITY OVER THIS REGION WILL WEAKEN AFTER ABOUT 08Z AS PRIMARY FOCI FOR ELEVATED CONVECTION SHIFT SW. 2. AFTER ABOUT 06Z...WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP OVER PORTIONS NW TX....ERN TX PANHANDLE AND/OR WRN OK. MODIFIED RUC SOUNDINGS SUGGEST SUFFICIENT MOISTENING IN 750-900 MB LAYER -- BENEATH 7-8 DEG C/KM MIDLEVEL LAPSE RATES...FOR ELEVATED MUCAPES TO REACH 800 J/KG BY END OF PERIOD OVER SWRN OK AND NW TX...WITH MINIMAL CINH. ADDITIONAL/CONDITIONAL THUNDER AREA MAY DEVELOP BENEATH OR JUST W OF LLJ AXIS FROM CENTRAL TX NNEWD ACROSS CENTRAL OK...AMIDST STRONGEST LOW LEVEL MOISTURE TRANSPORT. ...WRN/NRN OLYMPIC PENINSULA... STRONGEST MID-UPPER LEVEL ASCENT WITH MIDLEVEL TROUGH SHOULD REMAIN JUST N OF AREA ACROSS VANCOUVER ISLAND. GIVEN WEAKLY BUOYANT PROFILE EVIDENT IN UIL RAOB...BRIEF/ISOLATED LIGHTNING CANNOT BE RULED OUT...HOWEVER POTENTIAL APPEARS TOO TRANSIENT AND CONDITIONAL TO WARRANT GEN THUNDER OUTLOOK. ..EDWARDS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 04:12:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 23:12:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050414 SWODY1 SPC AC 050412 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1012 PM CST SAT NOV 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MIDDLE/UPPER LEVEL PATTERN WILL REMAIN GENERALLY ZONAL....EXCEPT FOR TROUGHING ACROSS CENTRAL CONUS. MAIN SHORTWAVE FEATURE WILL BE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM CENTRAL HIGH PLAINS TO SRN NM. THIS FEATURE IS EXPECTED TO MOVE SEWD AND AMPLIFY SOMEWHAT...EXTENDING FROM MO SWWD ACROSS CENTRAL TX TO N-CENTRAL MEX BY 06/12Z. AT SFC...WEAK FRONTAL ZONE AND TROUGH -- NOW EVIDENT OVER SRN TX PANHANDLE AND NWRN OK -- IS EXPECTED TO SHIFT SEWD ACROSS NW AND W-CENTRAL TX AHEAD OF SLOWLY DIGGING MIDLEVEL SYSTEM. WEAK SFC LOW NOW EVIDENT SW TCC MAY PROPAGATE SEWD ALONG THIS BOUNDARY. ...W-CENTRAL/SW TX... EXTENSIVE SW-NE PLUME OF CLOUDS/PRECIP -- WITH EMBEDDED AND LARGELY ELEVATED TSTMS -- IS EXPECTED TO DEVELOP FROM CENTRAL/N-CENTRAL TX NEWD ACROSS SERN OK INTO AR THROUGH MUCH OF PERIOD. THIS WILL LIMIT DESTABILIZATION...BOTH SFC AND ALOFT OVER MUCH OF SERN PLAINS...RED RIVER REGION AND ARKLATEX. HOWEVER...SFC HEATING MAY BE MORE PRONOUNCED DURING AFTERNOON ACROSS BIG COUNTRY...CONCHO VALLEY...LOWER PECOS RIVER AND ERN PERMIAN BASIN REGIONS OF TX. TSTMS MAY DEVELOP ALONG AND S OF BOUNDARY DURING AFTERNOON AND EVENING...SHIFTING EWD-SEWD TOWARD HILL COUNTRY WITH POTENTIAL FOR ISOLATED HAIL AND DAMAGING GUSTS. SFC MOISTURE S OF BOUNDARY IS EXPECTED TO RECOVER GRADUALLY ACROSS THIS REGION...AS SELY FLOW CONTINUES FROM MODIFYING NWRN-GULF AIR MASS. SFC DEW POINTS OVER MUCH OF REGION SHOULD REACH 60S BY AFTERNOON...BENEATH MODEST 6.5-7.5 DEG C/KM MIDLEVEL LAPSE RATES. ACCORDINGLY MODIFIED WRF SOUNDINGS SUGGEST MLCAPES 500-1000 J/KG OVER REGION. OTHER THAN HEATING ITSELF...LIFT MAY BE LIMITED. WEAK BOUNDARY LAYER WINDS ARE FCST...WHICH WILL LIMIT BOTH LOW LEVEL SHEAR AND CONVERGENCE INVOF FRONT/TROUGH. FLOW IS EXPECTED TO VEER WITH HEIGHT...BUT DEEP-LAYER SHEAR WILL BE MRGL OVER MOST OF REGION. SOME ENHANCEMENT TO LIFT AND SHEAR MAY OCCUR IF DIFFERENTIAL HEATING CAN DIURNALLY REINFORCE PREVIOUSLY WEAK BAROCLINIC GRADIENT ASSOCIATED WITH SFC BOUNDARY...HOWEVER ASSOCIATED MESOSCALE PROCESSES ARE TOO CONDITIONAL TO JUSTIFY GREATER PROBABILITY NUMBERS ATTM. ..EDWARDS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 12:31:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 07:31:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051233 SWODY1 SPC AC 051231 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 AM CST SUN NOV 05 2006 VALID 051300Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...OK SWD INTO CNTRL/SW TX... A SHORTWAVE TROUGH OVER THE TX PNHDL AT SUNRISE WILL TRANSLATE EWD ACROSS OK AND N TX THIS AFTN TO SRN MO/AR BY 12Z. A SECONDARY IMPULSE...NOW OVER AZ...WILL DIG SEWD INTO SW TX BY LATE EVE...REACHING SCNTRL TX BY EARLY MON MORNING. IN THE LWR LEVELS...A FRONT/TROUGH OVER THE SRN HIGH PLAINS WILL MOVE SEWD ACROSS NW AND WCNTRL TX IN WAKE OF THE LEAD IMPULSE. AT DAYBREAK...LOW-LEVEL MOISTURE/EXTENSIVE CLOUDS CONTINUED TO SPREAD NWWD ACROSS THE SRN PLAINS IN ADVANCE OF THE UPPER TROUGH. THE INITIAL WARM CONVEYOR BELT ENHANCED CONVECTION PERSISTED IN AN ARC FROM N TX TO THE OZARKS. ADDITIONAL TSTMS WERE DEVELOPING ACROSS WRN/CNTRL OK TIED TO THE STRONGEST H5-H3 Q-VECTOR CONVERGENCE ASSOCD WITH THE MID-LEVEL IMPULSE. AS THE LEAD IMPULSE MOVES ACROSS OK/N TX THROUGH THIS AFTN... CONVECTION/TSTMS WILL INCREASE ALONG WRN EDGE OF THE ORIGINAL WARM CONVEYOR FROM CNTRL/SERN OK SWD INTO N TX. AS A RESULT...BOUNDARY LAYER HEATING WILL BE MINIMAL AND SFC BASED TSTMS ARE NOT EXPECTED. NONETHELESS...MID-LEVEL COLD ADVECTION/STEEPENING LAPSE RATES ALOFT WILL TEND TO SUPPORT STRONGER ELEVATED TSTMS THAT MAY PRODUCE ISOLD LARGE HAIL. FARTHER S...SOUNDINGS INDICATE THAT SFC HEATING MAY BE MORE PRONOUNCED THIS AFTN ACROSS THE BIG COUNTRY...CONCHO VALLEY...LOWER PECOS RIVER AND ERN PERMIAN BASIN REGIONS OF TX. BOUNDARY LAYER MOISTURE SHOULD BE MAINTAINED DURING PEAK HEATING BENEATH MID-LEVEL LAPSE RATES AROUND 7 DEG C/KM...RESULTING IN MLCAPES TO 1000 J/KG. OVERALL FORCING FOR ASCENT WILL BE COMPARATIVELY WEAKER HERE THAN FARTHER N...UNTIL LATER TONIGHT WHEN THE SECONDARY AZ IMPULSE APPROACHES THE REGION. MOREOVER... VERTICAL WIND SHEAR WILL BE MARGINAL OVER MOST OF THE REGION...GENERALLY AOB 35 KTS. TSTMS MAY DEVELOP ALONG AND S OF THE SFC TROUGH DURING PEAK HEATING...PRIMARILY ACROSS THE LOW ROLLING PLAINS/BIG COUNTRY. TSTMS WILL BECOME MORE LIKELY AFTER DARK FARTHER S IN SWRN/WCNTRL TX IN ASSOCIATION WITH THE AZ IMPULSE. THIS ACTIVITY WILL THEN SHIFT E-SEWD TOWARD THE HILL COUNTRY OVERNIGHT WITH THE POTENTIAL FOR ISOLD LARGE HAIL AND DAMAGING WIND GUSTS. ATTM...ANTICIPATED ISOLD SEVERE THREATS PRECLUDE A CATEGORICAL SLGT RISK. FINALLY...TSTMS MAY DEVELOP FARTHER DOWNSTREAM ALONG THE SERN TX COAST BETWEEN 09-12Z. ATTM...IT APPEARS THE STRONGER STORMS SHOULD REMAIN OFFSHORE WHERE STRONGER INSTABILITY WILL EXIST. ..RACY/CROSBIE.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 16:02:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 11:02:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051604 SWODY1 SPC AC 051602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST SUN NOV 05 2006 VALID 051630Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...W-CENTRAL INTO NWRN TX... PAIR OF MID LEVEL IMPULSES WILL IMPACT THE SRN PLAINS TODAY AND TONIGHT. LEADING SYSTEM IS FOCUSING AN AREA OF THUNDERSTORMS INTO CENTRAL OK THIS MORNING...WITH WEAK LOW LEVEL WAA ALONG ASSOCIATED 20 KT H85 JET SUSTAINING A FEW ELEVATED THUNDERSTORMS INTO ERN OK/WRN AR. THIS ACTIVITY WILL LIKELY WEAKEN AS LEADING SYSTEM DAMPENS OUT AND EJECTS EWD TODAY. TRAILING SHORTWAVE TROUGH IS NOW DIGGING SEWD INTO CENTRAL/SRN NM. LOW LEVEL WINDS WILL LIKELY BACK AND SLIGHTLY STRENGTHEN THIS AFTERNOON INTO CENTRAL/WRN TX IN RESPONSE TO HEIGHT FALLS AHEAD OF THIS SYSTEM. LOW CLOUDS AND LIMITED SURFACE MOISTURE WILL HINDER DESTABILIZATION...THOUGH INCREASING LARGE SCALE ASCENT AND MODEST INSTABILITY WILL SUPPORT A CLUSTER OF THUNDERSTORMS LATER THIS AFTERNOON OVER WRN/NWRN TX WHICH SHOULD DEVELOP INTO A MCS AND SPREAD ESEWD ACROSS MORE OF NRN/CENTRAL TX THIS EVENING AND INTO ERN TX OVERNIGHT. INITIAL DEVELOPMENT MAY BECOME ROOTED INTO THE BOUNDARY LAYER ACROSS NWRN TX WHERE BREAKS IN LOW CLOUDS ARE EVIDENT THIS MORNING. HOWEVER...MOST OF THE ACTIVITY WILL LIKELY REMAIN OR BECOME INCREASINGLY ELEVATED THIS EVENING AND TONIGHT. OVERALL SETUP APPEARS MARGINAL FOR MORE THAN AN ISOLATED SEVERE THUNDERSTORM...THOUGH ONE OR TWO STRONGER STORMS LATE TODAY MAY PRODUCE HAIL/WIND AROUND SEVERE LEVELS. ..EVANS/GRAMS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 19:47:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 14:47:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051950 SWODY1 SPC AC 051947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST SUN NOV 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER SWRN OK INTO NWRN TX... ...OK/TX... AFTERNOON WATER VAPOR IMAGERY SHOWS VORTICITY MAXIMA OVER THE TX PNHDL AND S-CNTRL NM WITH LATEST MODEL GUIDANCE CONSISTENT IN SHIFTING THESE FEATURES SEWD THROUGH WRN INTO CNTRL TX TONIGHT. IN THE LOW-LEVELS...18Z MESOANALYSIS INDICATED LOW PRESSURE N OF MAF WITH INVERTED TROUGH/BAROCLINIC ZONE EXTENDING NEWD THROUGH E-CNTRL TX PNHDL INTO NERN OK. THE TRAILING PORTION OF THIS BOUNDARY THEN EXTENDED SWD INTO SWRN TX /E OF FST/. FINALLY...WARM FRONT STRETCHED FROM INTERSECTION WITH INVERTED TROUGH OVER THE SERN TX PNHDL OR SWRN OK ESEWD THROUGH S-CNTRL OK INTO NERN TX. THIS INVERTED TROUGH IS FORECAST TO TRANSITION TO MORE OF A COLD FRONT AS IT PUSHES SEWD INTO NWRN TX...WITH ASSOCIATED TRIPLE POINT LOW DEVELOPING SEWD INTO NWRN AND EVENTUALLY CNTRL TX OVERNIGHT. THUS FAR TODAY....TSTMS HAVE BEEN FOCUSED NEAR INVERTED TROUGH-850 MB FRONTAL ZONE FROM THE E-CNTRL TX PNHDL INTO WRN OK WITHIN A PLUME OF 7-7.5 C/KM MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF AROUND 500 J/KG. MORE RECENT DEVELOPMENT HAS OCCURRED NEAR WARM FRONT/INVERTED TROUGH TRIPLE POINT /NEAR CDS/ WITHIN ZONE OF STRONGER DEEP-LAYER FORCING FOR ASCENT ASSOCIATED WITH LEAD SHORT WAVE TROUGH. WIDESPREAD CLOUDS AND WEAKER MID-LEVEL LAPSE RATES WITH SWD EXTENT HAVE LIMITED AIR MASS DESTABILIZATION TODAY ACROSS MUCH OF WARM SECTOR WITH MLCAPES OF LESS THAN 1000 J/KG. A FEW BREAKS IN THE CLOUDS HAVE ALLOWED TEMPERATURES TO WARM INTO THE LOWER 70S ALONG THE RED RIVER /NEAR SPS/ AND WHEN COUPLED WITH DEWPOINTS OF AROUND 60F ARE LIKELY CONTRIBUTING TO LOCALLY STRONGER INSTABILITY. SHORT TERM RUC/OPERATIONAL WRF AND HIGH RESOLUTION WRF DATASETS SUGGEST THAT DEEP CONVECTION WILL BECOME INCREASINGLY FOCUSED THIS AFTERNOON INTO EVENING OVER NWRN TX AS THE STRONGER FORCING FOR ASCENT OVERSPREADS SLIGHTLY TO MODERATELY UNSTABLE WARM SECTOR. WHILE REGIONAL VWPS/PROFILERS INDICATE THAT VERTICAL SHEAR IS MARGINALLY STRONG /30-35 KT EFFECTIVE BULK SHEAR/ GIVEN THE DEGREE OF BUOYANCY...SOME POTENTIAL WILL EXIST FOR ROTATING STORMS CAPABLE OF SEVERE HAIL. STORMS SHOULD INCREASE IN AREAL COVERAGE OVERNIGHT OVER NRN INTO CNTRL TX AS AFOREMENTIONED SHORT WAVE TROUGHS PHASE AND CONTRIBUTE TO OVERALL AMPLIFICATION OF UPPER SYSTEM. HOWEVER...IT APPEARS THAT BOTH VERTICAL SHEAR AND INSTABILITY WILL REMAIN MARGINAL WITH ONLY A THREAT OF ISOLATED SEVERE STORMS CAPABLE OF SOME WIND/HAIL. ..MEAD.. 11/05/2006  From swody1 at goshenarc.org Mon Nov 6 00:55:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 19:55:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060057 SWODY1 SPC AC 060055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0655 PM CST SUN NOV 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS FAR S CENTRAL OK/CENTRAL N TX... ...N TX INTO S CENTRAL AND SERN OK... MCS IS ONGOING ATTM OVER N CENTRAL TX/S CENTRAL OK...ALONG WARM FRONT WHICH EXTENDS W-E ACROSS N TX JUST S OF THE RED RIVER. OVERALL DEGREE OF INSTABILITY AND SHEAR REMAINS MARGINAL /EVENING FORT WORTH RAOB REVEALS LESS THAN 500 J/KG MEAN-LAYER CAPE AND SHEAR OVER THE LOWER HALF OF THE STORM DEPTH 33 KT/. HOWEVER...A MESO-LOW HAS EVOLVED WITHIN A SMALL/FAIRLY INTENSE STORM CLUSTER ALONG THE WARM FRONT...AND A BOWING LINE SEGMENT CONTINUES TO ORGANIZE S OF THE MESO-LOW NOW MOVING EWD AT 35 KT. THEREFORE...WILL MAINTAIN A SMALL SLIGHT RISK AREA ALONG AND S OF THE RED RIVER...MAINLY ACROSS PARTS OF N TX. ELSEWHERE...A MORE LIMITED SEVERE POTENTIAL EXTENDS WWD INTO WRN N TX...WHERE SHEAR AND INSTABILITY REMAIN MARGINALLY-SUPPORTIVE OF SEVERE STORMS BUT WHERE CONVECTIVE DEVELOPMENT REMAINS LIMITED -- PRESUMABLY DUE TO LOW-LEVEL CAPPING. A LIMITED THREAT FOR MARGINAL HAIL ALSO APPEARS TO EXTEND INTO SERN OK AND NERN TX. OVERALL SEVERE THREAT ACROSS THE SRN PLAINS SHOULD CONTINUE FOR THE NEXT COUPLE OF HOURS...AND THEN BEGIN TO SLOWLY DIMINISH AS BOUNDARY LAYER STABILIZES AND STORMS MOVE INTO EVEN LESS-UNSTABLE AIRMASS OVER NERN TX/SERN OK. ..GOSS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 05:25:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 00:25:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060527 SWODY1 SPC AC 060525 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 PM CST SUN NOV 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH IS FORECAST TO STRENGTHEN/SHIFT SLOWLY EWD ACROSS THE S CENTRAL CONUS THIS PERIOD...AS VORT MAX/DEVELOPING UPPER LOW DIGS QUICKLY SSEWD FROM THE CENTRAL/NRN HIGH PLAINS TOWARD THE LOWER MS VALLEY THROUGH THE END OF THE PERIOD. WIDESPREAD CONVECTIVE PRECIPITATION IS FORECAST ACROSS THE S CENTRAL CONUS AHEAD OF THIS FEATURE AND ASSOCIATED WEAK SURFACE LOW/TROUGH MOVING OUT OF E TX AND ACROSS THE LOWER MS VALLEY THROUGH 07/12Z. ...WRN AND CENTRAL GULF COAST REGION... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE S CENTRAL CONUS...WITH ALL MODELS FORECASTING A SIGNIFICANT INCREASE IN CONVECTIVE COVERAGE WITH TIME ACROSS THE LOWER MS VALLEY REGION AND VICINITY. WITH CLOUDS/PRECIPITATION AND ASSOCIATED WEAK LAPSE RATES FORECAST TO LIMIT ANY POTENTIAL FOR DESTABILIZATION...EXPECT SEVERE THREAT TO REMAIN LOW ACROSS MOST PARTS OF THE REGION. MODELS HINT THAT WARM FRONT -- AT THE LEADING EDGE OF RICHER GULF MOISTURE -- MAY ATTEMPT TO WORK NWD/ONSHORE ACROSS SRN LA/SRN MS DURING THE DAY. SHOULD THIS OCCUR...FAVORABLE LOW-LEVEL VEERING/SHEAR INVOF BOUNDARY AND SLIGHTLY GREATER INSTABILITY -- DRIVEN BY TROPICAL BOUNDARY LAYER -- WOULD SUPPORT A POTENTIAL FOR LOW-LEVEL ROTATION AND POSSIBLY A LIMITED TORNADO THREAT. ATTM...CONFIDENCE THAT MOIST/SUFFICIENTLY-UNSTABLE AIRMASS WILL WORK INLAND REMAINS LOW...AND THUS WILL MAINTAIN ONLY A LOW-PROBABILITY SEVERE THREAT ACROSS THIS REGION. SLIGHT RISK MAY BE WARRANTED IN LATER OUTLOOKS IF IT APPEARS THAT SUFFICIENT MOISTENING/DESTABILIZATION MAY OCCUR ONSHORE. ...PARTS OF OK AND TX... AS COLD /AROUND -20 C AT H5/ MID-LEVEL AIR SPREADS SSEWD ACROSS OK AND PARTS OF TX NEAR PEAK HEATING -- IN CONJUNCTION WITH UPPER VORT MAX/LOW...MARGINAL DESTABILIZATION IS EXPECTED. DEGREE OF INSTABILITY AND LARGE-SCALE ASCENT AHEAD OF APPROACHING UPPER FEATURE MAY SUPPORT THE EVENTUAL DEVELOPMENT OF SCATTERED TO ISOLATED/LOW-TOPPED CONVECTION. GIVEN COLD MID-LEVEL AIR/STEEP LAPSE RATES...SMALL TO MARGINALLY-SEVERE HAIL MAY BE POSSIBLE WITH ANY STRONGER UPDRAFTS. THREAT SHOULD END QUICKLY THROUGH SUNSET WITH THE LOSS OF DAYTIME HEATING. ..GOSS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 12:55:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 07:55:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061256 SWODY1 SPC AC 061254 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 AM CST MON NOV 06 2006 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WATER VAPOR IMAGERY THIS MORNING SHOWS VERY STRONG ZONAL FLOW AT MID/UPPER LEVELS INTO THE PACIFIC NORTHWEST WITH RIDGING FROM CENTRAL CA NEWD INTO MT. THIS IS RESULTING IN A RAPIDLY DEEPENING TROUGH DIVING SWD THROUGH WRN KS AT THIS TIME WHICH IS EXPECTED TO BECOME A MID/UPPER LEVEL LOW OVER OK BY THIS AFTERNOON AND MOVE INTO THE LOWER MS VALLEY TONIGHT. SURFACE FEATURES SEEM TO BE WEAK ACROSS THE SRN PLAINS DOMINATED MORE BY CONVECTIVE OUTFLOW ASSOCIATED WITH LINE OF STORMS FROM E CENTRAL AND SERN AR SWWD INTO W CENTRAL LA...THEN WWD ACROSS NRN TX. S OF THIS BOUNDARY IS A POOL OF MODERATELY UNSTABLE AIR WHERE MLCAPE RANGES FROM 1000 J/KG OVER PARTS OF SERN TX TO 2000 J/KG OVER WRN SECTIONS IN THE MIDDLE RIO GRANDE VALLEY. IN THE PAST FEW HOURS...SOME STRONG/ISOLATED SEVERE STORMS HAVE BEEN OCCURRING FROM W OF LFK TO AROUND SAT AHEAD OF WEAK MID LEVEL TROUGH THAT EXTENDS FROM ERN OK SWWD INTO THE MIDDLE RIO GRANDE. ...PARTS OF SERN TX INTO SRN LA... TWO FACETS TO CONSIDER HERE IS THAT AS THE MID/UPPER LOW DIVES SWD THROUGH TONIGHT...THE SRN BRANCH OF THE UPPER LEVEL JET EXTENDS FROM EXTREME S TX NEWD INTO SRN MS/AL TAKING FAVORABLE EXIT REGION QUADRANT ACROSS SERN TX INTO CENTRAL LA MAINLY TONIGHT. SRN PARTS OF MAIN LOW LEVEL JET PULLS OUT OF SERN MS THRU MID TN TONIGHT CREATING A FAVORABLE AREA OF DEEP LAYER SHEAR FROM THE SERN TX AND LA GULF COAST REGION INTO CENTRAL LA. THUS...GIVEN FAVORABLE KINEMATICS DURING A CLIMATOLOGICAL FAVORABLE TIME PERIOD ACROSS THIS REGION...HAVE KEPT LOW TORNADO PROBABILITIES ACROSS THIS REGION FOR TONIGHT. BUT...ALSO GIVEN THAT ISOLATED SUPERCELLS ARE OCCURRING THIS MORNING WITH CURRENT THERMODYNAMIC PROFILES...EXTENDED THE AREA WWD AS FIRST TROUGH MOVES THROUGH REGION EARLY TODAY. ...PARTS OF WESTERN OK INTO N CENTRAL TX... MID/UPPER LEVEL JET ON BACKSIDE OF RAPIDLY DEEPENING LOW WILL TRAVEL FROM SWRN KS INTO CENTRAL TX THROUGH EARLY TONIGHT. MORNING RAOB DATA FROM DDC SHOWS -20C AT 500 MB AND STEEP LOW-MID LEVEL LAPSE RATES VERY NEAR 8C/KM. THUS...AS TEMPERATURES REACH MID 60S TO 70 DEG F...POTENTIAL INSTABILITY COULD BE AROUND 1000 J/KG LEADING TO THE POSSIBILITY OF ISOLATED STRONG/SEVERE THUNDERSTORMS WITH LARGE HAIL BEING THE MAIN THREAT LATE THIS AFTERNOON AND EARLY TONIGHT. ..MCCARTHY/CROSBIE.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 16:19:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 11:19:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061621 SWODY1 SPC AC 061619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1019 AM CST MON NOV 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH OVER THE CENTRAL/SRN PLAINS IS FORECAST TO DEEPEN TO A CLOSED LOW OVER THE LOWER MS VALLEY...IN RESPONSE TO A JET MAX AND THERMAL TROUGH DIGGING SEWD DOWN THE BACKSIDE OF THE SYSTEM. A REFLECTION OF THE UPPER TROUGH WAS NOTED AT THE SURFACE WITH A WEAK LOW OVER CENTRAL AR AND A TROUGH/COLD FRONT EXTENDING SWWD FROM THE LOW INTO NERN AND SRN TX. THE WEAK LOW SHOULD MOVE EWD INTO WRN TN TONIGHT WITH THE TRAILING TROUGH/FRONT PUSHING ACROSS THE LOWER MS VALLEY. ...SERN TX EWD INTO SWRN AL INTO SRN LA... LEADING EDGE OF LARGE PRECIPITATION AREA EXTENDED FROM WRN TN/WRN MS SWWD INTO SRN LA/SERN TX AT MID MORNING. PRESENCE OF COLD POOL AND EWD MOVING UPPER TROUGH SHOULD RESULT IN PRECIPITATION SPREADING EWD ACROSS THE REMAINDER OF TN/MS...AND SEWD ACROSS SRN LA AND SERN TX. WIDESPREAD CLOUDS AND WEAK LAPSE RATES WILL RESULT IN ONLY MARGINAL INSTABILITY. WITH THE STRONGEST MASS CONVERGENCE/LIFT EXPECTED TO BE LOCATED ACROSS PORTIONS OF THE TN VALLEY...THREAT FOR SEVERE APPEARS LOW. THOUGH INSTABILITY WILL BE A LITTLE GREATER IN AN AREA BOUNDED BY VCT-CRP-AUS THIS AFTERNOON ...SUBSIDENCE FROM THE RIGHT EXIT REGION OF APPROACHING UPPER JET WILL STRENGTHEN CAPPING THROUGHOUT THE DAY AND REDUCE CONVECTIVE THREAT. ...CENTRAL/WRN OK SWD INTO NRN TX... THERMAL TROUGH ALOFT...WITH 500MB TEMPERATURES NEAR -20C...WILL CREATE A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR A FEW THUNDERSTORMS TO DEVELOP THIS AFTERNOON...ONCE CLOUDS DECREASE AND TEMPERATURES WARM AT LEAST INTO THE LOWER 60S. CLOUDS HAVE CLEARED ACROSS EXTREME NWRN OK AND SHOULD DECREASE ACROSS THE WRN HALF OF OK/NWRN TX BY LATE AFTERNOON. GIVEN THE EXPECTED STEEP MID LEVEL LAPSE RATES...NEAR 8C/KM...AND MUCAPES UP TO 1000 J/KG...ISOLATED THUNDERSTORMS WITH MARGINALLY SEVERE HAIL WOULD BE POSSIBLE. ..IMY/GRAMS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 20:04:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 15:04:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062001 SWODY1 SPC AC 061958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON NOV 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WRN/CNTRL GULF COAST... LONG-LIVED EXPANSIVE MCS CONTINUES ITS EWD PROGRESSION ACROSS THE LOWER MS VALLEY REGION THIS AFTERNOON. NRN MOST PORTIONS OF THIS ACTIVITY ARE WELL CORRELATED WITH AN UPPER VORT OVER SERN MO...WHILE TRAILING PORTIONS ACROSS MS INTO SERN LA SEEM TO BE DRIVEN IN LARGE PART DUE TO SIGNIFICANT COLD POOL DEVELOPMENT BENEATH PRECIPITATION SHIELD OVER LA/WRN MS. ADDITIONALLY...STRENGTHENING LOW LEVEL WARM ADVECTION APPEARS TO BE DRIVING NUMEROUS SHOWERS OVER THE MS DELTA REGION...SOME OF WHICH ARE NOW DEEP ENOUGH FOR SOME LIGHTNING. WEAK LAPSE RATE ENVIRONMENT WILL LIMIT UPDRAFT STRENGTH ACROSS THIS REGION...ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS DEEPER ROTATION. GREATEST THREAT WITH THIS ACTIVITY SHOULD BE GUSTY WINDS...OR PERHAPS ONE OR TWO WEAK TORNADOES. UPSTREAM ACROSS THE COASTAL PLAINS OF TX...FLOW HAS VEERED SUBSTANTIALLY IN THE WAKE OF EARLY MORNING MCS WITH DEEP WNWLY FLOW NOW OBSERVED ACROSS THE UPPER TX COAST INTO CNTRL TX. LATEST DIAGNOSTIC DATA SUGGEST LOW LEVEL LAPSE RATES HAVE STEEPENED AS BOUNDARY LAYER HAS WARMED...HOWEVER SWWD PROGRESSION OF MULTI-FACETED CONVECTIVE OUTFLOW DOES NOT APPEAR PARTICULARLY FAVORABLE FOR SUSTAINING LONG-LIVED SEVERE UPDRAFTS. AT THIS TIME IT APPEARS ONGOING THUNDERSTORM ACTIVITY ALONG ADVANCING WIND SHIFT...INVOF BASTROP COUNTY...SHOULD CONTINUE SEWD INTO INCREASINGLY HOSTILE AIRMASS. IN ALL LIKELIHOOD THIS SHOULD LIMIT SEVERE POTENTIAL TO MARGINALLY SEVERE HAIL AS UPDRAFTS STRUGGLE TO SUSTAIN THEMSELVES WITH WEAK LOW LEVEL CONVERGENCE. ..DARROW.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 21:39:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 16:39:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062141 SWODY1 SPC AC 062138 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0338 PM CST MON NOV 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WRN/CNTRL GULF COAST... LONG-LIVED EXPANSIVE MCS CONTINUES ITS EWD PROGRESSION ACROSS THE LOWER MS VALLEY REGION THIS AFTERNOON. NRN MOST PORTIONS OF THIS ACTIVITY ARE WELL CORRELATED WITH AN UPPER VORT OVER SERN MO...WHILE TRAILING PORTIONS ACROSS MS INTO SERN LA SEEM TO BE DRIVEN IN LARGE PART DUE TO SIGNIFICANT COLD POOL DEVELOPMENT BENEATH PRECIPITATION SHIELD OVER LA/WRN MS. ADDITIONALLY...STRENGTHENING LOW LEVEL WARM ADVECTION APPEARS TO BE DRIVING NUMEROUS SHOWERS OVER THE MS DELTA REGION...SOME OF WHICH ARE NOW DEEP ENOUGH FOR SOME LIGHTNING. WEAK LAPSE RATE ENVIRONMENT WILL LIMIT UPDRAFT STRENGTH ACROSS THIS REGION...ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS DEEPER ROTATION. GREATEST THREAT WITH THIS ACTIVITY SHOULD BE GUSTY WINDS...OR PERHAPS ONE OR TWO WEAK TORNADOES. UPSTREAM ACROSS THE COASTAL PLAINS OF TX...FLOW HAS VEERED SUBSTANTIALLY IN THE WAKE OF EARLY MORNING MCS WITH DEEP WNWLY FLOW NOW OBSERVED ACROSS THE UPPER TX COAST INTO CNTRL TX. LATEST DIAGNOSTIC DATA SUGGEST LOW LEVEL LAPSE RATES HAVE STEEPENED AS BOUNDARY LAYER HAS WARMED...HOWEVER SWWD PROGRESSION OF MULTI-FACETED CONVECTIVE OUTFLOW DOES NOT APPEAR PARTICULARLY FAVORABLE FOR SUSTAINING LONG-LIVED SEVERE UPDRAFTS. AT THIS TIME IT APPEARS ONGOING THUNDERSTORM ACTIVITY ALONG ADVANCING WIND SHIFT...INVOF BASTROP COUNTY...SHOULD CONTINUE SEWD INTO INCREASINGLY HOSTILE AIRMASS. IN ALL LIKELIHOOD THIS SHOULD LIMIT SEVERE POTENTIAL TO MARGINALLY SEVERE HAIL AS UPDRAFTS STRUGGLE TO SUSTAIN THEMSELVES WITH WEAK LOW LEVEL CONVERGENCE. ..DARROW.. 11/06/2006  From swody1 at goshenarc.org Tue Nov 7 00:54:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 19:54:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070056 SWODY1 SPC AC 070054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST MON NOV 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SRN AL AND PORTIONS OF THE FL PANHANDLE... NE-SW BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS CONTINUES MOVING EWD ACROSS THE CENTRAL GULF COAST REGION...INTO AN ENVIRONMENT OF VERY WEAK INSTABILITY WHICH DECREASES FURTHER WITH EWD EXTENT. LOW-LEVEL SHEAR DOWNSTREAM OF ONGOING CONVECTION REMAINS SUPPORTIVE OF LOW-LEVEL UPDRAFT ROTATION...AND SOME HINTS OF WEAK CIRCULATION CONTINUE TO BE REVEALED BY AREA WSR-88DS -- THOUGH PRIMARILY OFFSHORE. AS STORMS MOVE EWD INTO EVEN LESS FAVORABLE THERMODYNAMIC ENVIRONMENT...ONSHORE SEVERE THREAT WILL CONTINUE TO DIMINISH. HOWEVER...WILL MAINTAIN LOW SEVERE PROBABILITY ATTM ACROSS COASTAL PORTIONS OF SRN AL AND THE FL PANHANDLE FOR THE NEXT FEW HOURS. ..GOSS.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 05:46:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 00:46:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070548 SWODY1 SPC AC 070546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH IS FORECAST TO MOVE EWD ACROSS THE SERN U.S. THIS PERIOD. MEANWHILE...FAST/ZONAL FLOW WILL SPREAD ACROSS THE NWRN AND INTO THE N CENTRAL CONUS N OF LOW-AMPLITUDE RIDGE OVER THE SWRN QUARTER OF THE COUNTRY. AT THE SURFACE...A WEAK LOW AND ASSOCIATED COLD FRONT ASSOCIATED WITH THE UPPER TROUGH WILL ALSO SHIFT EWD ACROSS AL/GA/FL THROUGH THE END OF THE PERIOD. ...FL NWD ALONG THE IMMEDIATE ATLANTIC COAST... SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO BE ONGOING ACROSS THE SOUTHEAST AT THE START OF THE PERIOD...AHEAD OF LARGE UPPER TROUGH. WITH WIDESPREAD CLOUDS AND PRECIPITATION ACROSS THIS REGION...POTENTIAL FOR DESTABILIZATION APPEARS TO BE QUITE LIMITED. THEREFORE...DESPITE MODERATELY-STRONG DEEP-LAYER FLOW ACROSS THE SOUTHEAST...SEVERE THREAT APPEARS TO BE LOW ATTM. WILL MAINTAIN LOW PROBABILITY THREAT ACROSS FL...AS COLD FRONT IS FORECAST TO MOVE EWD/SEWD ACROSS THE FL PENINSULA THROUGH THE PERIOD. WILL ALSO MAINTAIN A LOW-PROBABILITY THREAT ALONG THE IMMEDIATE COASTS OF SERN GA AND THE CAROLINAS...TO ACCOUNT FOR THE POSSIBILITY THAT HIGHER THETA-E GULF STREAM AIRMASS NEAR THE COAST MAY SUPPORT STORM DEVELOPMENT INVOF FRONT AS IT APPROACHES LATE IN THE PERIOD. ATTM HOWEVER...IT APPEARS THAT MOST IF NOT ALL SURFACE-BASED STORM DEVELOPMENT SHOULD REMAIN OFFSHORE. ..GOSS.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 12:38:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 07:38:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071240 SWODY1 SPC AC 071238 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0638 AM CST TUE NOV 07 2006 VALID 071300Z - 081200Z ...NO SVR TSTM AREAS FORECAST... MORNING SATELLITE LOOPS SHOW VIGOROUS UPPER TROUGH DIGGING ACROSS THE LOWER MS VALLEY. A LEAD SHORTWAVE TROUGH IS NOTED OVER GA/AL...ACCOMPANYING A LINE OF SHOWERS AND THUNDERSTORMS. THE PRIMARY SURFACE LOW IS CURRENTLY OVER WESTERN TN...BUT CYCLOGENESIS IS EXPECTED TO SHIFT RAPIDLY EASTWARD TO THE CAROLINA COAST BY AFTERNOON. LARGE SCALE FORCING FOR ASCENT WILL BE IN PLACE THROUGHOUT THE SOUTHEAST STATES TODAY...YIELDING A CONTINUATION OF SCATTERED SHOWERS AND THUNDERSTORMS FROM MS/AL INTO NC/VA DURING THIS PERIOD. ...MS/AL/FL/GA... LOW LEVEL TRAJECTORIES ARE SOUTHEASTERLY ACROSS MUCH OF THE FL PENINSULA AND EASTERN GULF OF MEXICO. THIS IS NOT TAPPING THE TROPICAL MOISTURE FARTHER SOUTH...AND IS ONLY RESULTING IN DEWPOINTS IN THE LOWER 60S ACROSS THE FL PANHANDLE. ONLY MODEST INCREASES IN MOISTURE ARE EXPECTED IN THIS AREA TODAY. THUS...MLCAPE VALUES WILL GENERALLY BE BELOW 500 J/KG OVER PARTS OF MS/AL/GA/FL. ISOLATED STORMS ALONG THE COAST MAY POSE A RISK OF LOCALLY GUSTY WINDS OR A BRIEF TORNADO. HOWEVER...OVERALL THREAT APPEARS RATHER LOW. ...SC/NC... LOW LEVEL MOISTURE/INSTABILITY IS ALSO FORECAST TO INCREASE THIS AFTERNOON OVER THE CAROLINAS AS SURFACE CYCLOGENESIS OCCURS AND SOUTHEASTERLY LOW LEVEL WINDS STRENGTHEN. SURFACE WARM FRONT WILL LIKELY DEVELOP ALONG OR JUST OFF THE COAST AND MOVE SLOWLY INLAND AHEAD OF LOW. WIDESPREAD PRECIPITATION IS LIKELY TO PRECLUDE STRONG DAYTIME HEATING IN THIS AREA. NEVERTHELESS...MARGINAL INSTABILITY MAY BE SUFFICIENT GIVEN STRONG LOW LEVEL WINDS VEERING/INCREASING WITH HEIGHT AND LARGE SCALE FORCING. STRONGEST CELLS COULD PRODUCE DAMAGING WINDS OR A TORNADO. WILL MAINTAIN ONLY LOW SEVERE PROBABILITIES AT THIS TIME DUE TO LOW CONFIDENCE IN THE DEVELOPMENT OF STRONGER INSTABILITY. ..HART/CROSBIE.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 16:38:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 11:38:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071639 SWODY1 SPC AC 071637 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1037 AM CST TUE NOV 07 2006 VALID 071630Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG MID/UPPER LEVEL LOW OVER THE MIDDLE TN VALLEY THIS MORNING IS EXPECTED TO SLOWLY DRIFT EWD OVER THE NC/SC/GA TRIPLE POINT DURING THE REMINDER OF THE PERIOD. STRONG NRN BRANCH WILL EXTEND FROM THE PACIFIC NORTHWEST INTO THE NRN PLAINS AND UPPER GREAT LAKES AS MID LEVEL RIDGING HOLDS OVER THE SWRN U.S. MORNING SFC ANALYSIS INDICATED LOW OVER NWRN TN WITH AN OCCLUSION EXTENDING SWD THROUGH THE CENTRAL FL PANHANDLE. A WARM FRONTAL/CONVECTIVE BOUNDARY EXTENDED FROM THE NERN GULF OF MEXICO EWD ACROSS NRN FL WITH STRONG LARGE SFC RIDGING ANCHORED JUST SE OF NEW ENGLAND BRINGING NELY FLOW ACROSS PARTS OF THE MID ATLANTIC REGION. ...ERN CAROLINAS... MORNING NAM IS WEAK ON THE DETAILS OF DEVELOPING SFC LOW ANYWHERE FROM NRN FL INTO CENTRAL SC/NC LATER THIS AFTERNOON AND TONIGHT. LATEST RUC FORECAST BRINGS THE LOW THRU THE ERN FL PANHANDLE INTO S CENTRAL GA BY 08/00Z WHICH IS CLOSER TO WHAT MAY REALLY HAPPEN. USUALLY IN THESE CASES CONSIDERING THE STRONG PRESSURES OVER THE MID ATLANTIC REGION...THE SURFACE LOW DEVELOPMENT WILL DEPEND ON THE COLD AIR DAMMING ALONG THE ERN APPALACHIANS AND THE GULF STREAM OFF COAST CAROLINA. SO...THINK THAT ONE LOW WILL BE A REFLECTION OF THE UPPER LOW OVER NRN GA...WHILE ANOTHER LOW WILL DEVELOP ALONG THE WARM FRONT N OF JAX THAT WILL MOVE NWD ALONG THE COASTAL AREAS. MODELS DEPICT VERY STRONG SHEAR PROFILES IN THE HODOGRAPHS DUE TO STRONG GRADIENT FLOW DEVELOPING BY 08/00Z. HOWEVER...WEAK LOW/MID LEVEL LAPSE RATES AND INSTABILITY MAKES FOR A LOW PROBABILITY FOR TORNADOES/WATERSPOUTS OVER THE CAROLINAS EARLY TONIGHT. ELSEWHERE...STRONG THUNDERSTORMS COULD MOVE INTO THE TPA AREA NWD...OR ACROSS PARTS OF THE KEYS AS WEAK SFC LOW OFFSHORE MOVES EWD THEN WEAKENS DUE TO CURRENT CONVECTION NW OF THE TPA AREA. ..MCCARTHY/JEWELL.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 19:38:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 14:38:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071940 SWODY1 SPC AC 071937 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0137 PM CST TUE NOV 07 2006 VALID 072000Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...FL PENINSULA... LAPSE RATES ACROSS THE CNTRL/SRN PENINSULA HAVE BEEN SLOW TO STEEPEN AHEAD OF UPPER TROUGH DUE IN LARGE PART TO EXTENSIVE CLOUDINESS AND PRECIPITATION. LATEST RADAR DATA SUGGESTS STRONGEST CONVECTION REMAINS OVER WARM WATERS OF THE ERN GULF WHERE BUOYANCY IS A BIT GREATER. OF PARTICULAR CONCERN IS THE WELL ORGANIZED COMPLEX APPROACHING THE WCNTRL COAST. A LONG-LIVED MVC IS LOCATED JUST NW OF PIE WITH A BAND OF STRONG STORMS EXTENDING FROM E-SW OF CIRCULATION CENTER. AIRMASS INLAND IS NOT PARTICULARLY UNSTABLE AND IT APPEARS THE GREATEST THREAT WITH THIS ACTIVITY WILL BE STRONG WINDS AND PERHAPS AN ISOLATED SEVERE GUST. ALTHOUGH THIS CLUSTER OF ORGANIZED STORMS WILL LIKELY MOVE ACROSS THE CNTRL PENINSULA...ORGANIZED DAMAGING WINDS ARE NOT EXPECTED...AND GRADUAL WEAKEN IS CERTAINLY POSSIBLE OVER MORE STABLE INLAND AREAS. ...CAROLINA COAST... LATER TONIGHT LOW LEVEL WARM ADVECTION WILL INCREASE IN THE WAKE OF CURRENT EJECTING SHORTWAVE. REGIONAL RADAR DATA EXHIBITS A WELL DEFINED VORT CENTER ALONG THE NC/SC BORDER...JUST ENE OF FLO. BROADER PRECIPITATION SHIELD WILL LIFT NORTH OF THIS REGION WITH GRADUAL BOUNDARY LAYER DESTABILIZATION EXPECTED OVER THE NEXT 6-18 HOURS. IT APPEARS MODIFIED MARITIME AIRMASS WILL SPREAD INLAND ENHANCING THE BUOYANCY AND THUNDERSTORM POTENTIAL AHEAD OF MAIN UPPER TROUGH. IF SUFFICIENT INSTABILITY CAN SPREAD INLAND THEN SUPERCELLS ARE CERTAINLY POSSIBLE...AND TORNADO THREAT MAY INCREASE...ESPECIALLY AFTER DARK. COASTAL SC/NC WILL BE MONITORED AT 01Z OUTLOOK FOR POSSIBLE UPGRADE TO SLIGHT RISK. ..DARROW.. 11/07/2006  From swody1 at goshenarc.org Wed Nov 8 00:59:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 19:59:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080101 SWODY1 SPC AC 080059 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 PM CST TUE NOV 07 2006 VALID 080100Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SRN FL... SUPERCELL WHICH PRODUCED SEVERAL TORNADO REPORTS ACROSS CENTRAL AND E CENTRAL FL EARLIER HAS MOVED OFFSHORE. MEANWHILE...BOUNDARY-LAYER FLOW ACROSS THE REMAINDER OF E CENTRAL AND INTO SRN FL IS MORE SWLY...RESULTING IN LESS FAVORABLE LOW-LEVEL SHEAR. THEREFORE...GREATEST TORNADO THREAT APPEARS TO HAVE PASSED. DEGREE OF INSTABILITY AND DEEP-LAYER SHEAR SE OF FRONT -- WHICH LIES NNE-SSW ACROSS CENTRAL FL -- REMAINS SUFFICIENT FOR A FEW STRONGER/ROTATING STORMS. HOWEVER...MARGINAL SEVERE THREAT IS FORECAST TO FURTHER DIMINISH WITH TIME...GIVEN WEAK LOW-LEVEL CONVERGENCE AND SLOWLY STABILIZING BOUNDARY LAYER. ...COASTAL CAROLINAS... MOIST /LOW TO MID 60S DEWPOINTS/ BOUNDARY LAYER HAS WORKED INLAND ACROSS NERN SC AND INTO ERN SC...E AND NE OF WEAK SURFACE LOW OVER ERN SC. DESPITE THIS...INSTABILITY IS MINIMAL -- PER LATEST OBJECTIVE ANALYSES...AND EVENING RAOBS WHICH REVEAL VERY WEAK LAPSE RATES. GIVEN AMPLE LOW-LEVEL SHEAR AND FAIRLY MOIST BOUNDARY LAYER...WILL MAINTAIN A VERY LOW-PROBABILITY THREAT FOR A BRIEF TORNADO. HOWEVER...THREAT WILL CONTINUE TO DIMINISH THROUGH THE EVENING AS SURFACE LOW/FRONT MOVES OFFSHORE. ..GOSS.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 05:46:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 00:46:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080547 SWODY1 SPC AC 080546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST TUE NOV 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE UPPER PATTERN IS FORECAST THIS PERIOD AS A LOW-AMPLITUDE TROUGH MOVES INTO THE WRN U.S. AND A STRONGER TROUGH/UPPER LOW MOVES EWD ACROSS THE ERN CONUS. IN BETWEEN...A LOW-AMPLITUDE RIDGE WILL SHIFT EWD ACROSS THE S CENTRAL 2/3 OF THE COUNTRY. AT THE SURFACE...COLD FRONT SHOULD EXTEND FROM A SURFACE LOW IN ERN NC SWD/SWWD ACROSS SRN FL AT THE START OF THE PERIOD. THIS LOW SHOULD MOVE NWD WITH TIME TOWARD SRN NEW ENGLAND...WHILE COLD FRONT MOVES EWD INTO THE ATLANTIC/SEWD ACROSS FL. A SECOND COLD FRONT EXTENDING ENE-WSW ACROSS THE NWRN CONUS SHOULD MOVE SEWD ACROSS THE ROCKIES/NRN AND CENTRAL PLAINS...AS ASSOCIATED LOW MOVES FROM SRN ALBERTA RAPIDLY EWD TOWARD JAMES BAY THROUGH THE END OF THE PERIOD. ...S FL... A FEW SHOWERS AND PERHAPS A THUNDERSTORM OR TWO MAY DEVELOP OVER S FL AND THE KEYS AHEAD OF SWD-MOVING COLD FRONT DURING THE FIRST HALF OF THE PERIOD. WEAK CONVERGENCE ALONG FRONT AND LIMITED INSTABILITY SUGGESTS VERY LITTLE IF ANY SEVERE THREAT. ...SRN NEW ENGLAND INTO THE CAROLINAS... EFFECTIVE SURFACE BOUNDARY IS FORECAST TO BE OFF THE SERN U.S. COAST BY THE START OF THE PERIOD. HOWEVER...COLD AIR ALOFT ASSOCIATED WITH UPPER LOW MOVING EWD ACROSS THE CAROLINAS/MID-ATLANTIC REGION MAY COMBINE WITH LIMITED DAYTIME HEATING TO YIELD MARGINAL INSTABILITY. THUS...WILL MAINTAIN THUNDER FORECAST ACROSS THIS REGION -- AND EXPAND IT NEWD INTO SRN NEW ENGLAND...WHERE A FEW STRIKES COULD OCCUR DURING THE LATTER HALF OF THE PERIOD. ...PAC NW... AS LOW-AMPLITUDE UPPER TROUGH AND ASSOCIATED COLDER AIR ALOFT /-28 TO -30C AT H5/ SETTLES EWD INTO THE PAC NW...A FEW LIGHTNING STRIKES WILL BE POSSIBLE WITHIN LARGER AREA OF CONVECTIVE PRECIPITATION. GREATEST POTENTIAL WILL LIKELY EXIST THROUGH THE AFTERNOON NEAR DIURNAL PEAK HEATING. ...NERN ND INTO THE WRN UPPER GREAT LAKES REGION... A FEW LIGHTNING STRIKES WILL BE POSSIBLE ACROSS PORTIONS OF THE N CENTRAL CONUS -- AND PARTICULARLY ACROSS THE BORDER INTO S CENTRAL CANADA -- AS SHORT-WAVE TROUGH AND ASSOCIATED SURFACE LOW MOVE QUICKLY EWD ACROSS THIS REGION. ..GOSS.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 12:49:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 07:49:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081250 SWODY1 SPC AC 081248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST WED NOV 08 2006 VALID 081300Z - 091200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH OVER THE SOUTHEASTERN STATES WILL MOVE SLOWLY EASTWARD AND OFFSHORE BY THURSDAY MORNING. MEANWHILE...LOW AMPLITUDE UPPER TROUGH WILL MOVE RAPIDLY EASTWARD ACROSS THE WESTERN STATES. ALTHOUGH THREAT OF SEVERE THUNDERSTORMS APPEARS RATHER LOW TODAY...SEVERAL AREAS MAY SEE ISOLATED THUNDERSTORM ACTIVITY. ...MID ATLANTIC INTO SOUTHERN NEW ENGLAND... LINGERING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FROM THE MID ATLANTIC REGION INTO SOUTHERN NEW ENGLAND. DESPITE ONLY MARGINAL INSTABILITY...LARGE SCALE FORCING FOR ASCENT IS QUITE STRONG AHEAD OF UPPER TROUGH. THREAT SHOULD DIMINISH FROM WEST TO EAST ACROSS THE MID ATLANTIC REGION DURING THE DAY...WHILE POTENTIAL FOR CONVECTION MAY CONTINUE OVER SOUTHERN NEW ENGLAND THROUGH THE NIGHT. NO ORGANIZED SEVERE STORMS ARE ANTICIPATED. ...CAROLINAS... CORE OF UPPER LOW WILL MOVE ACROSS SC/NC TODAY. POCKET OF COLD MID LEVEL TEMPERATURES /-20C AT 500MB/ WILL YIELD RELATIVELY STEEP MID LEVEL LAPSE RATES AND MARGINAL INSTABILITY. SCATTERED AFTERNOON THUNDERSTORMS MAY DEVELOP IN THIS REGION...BEFORE QUICKLY DIMINISHING AFTER DARK. SMALL HAIL WILL BE POSSIBLE IN STRONGER STORMS...BUT POTENTIAL FOR SEVERE STORMS APPEARS LOW. ...SOUTH FL... SECONDARY SHORTWAVE TROUGH IS EVIDENT IN WATER VAPOR IMAGERY OVER THE EASTERN GULF OF MEXICO. THIS FEATURE WILL MOVE ACROSS THE FL PENINSULA TODAY...PROVIDING A THREAT OF ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS. ...PACIFIC NORTHWEST... STRONG ONSHORE FLOW WILL CONTINUE ALONG THE WA/ORE COAST TODAY AHEAD OF APPROACHING UPPER TROUGH. COOLING TEMPERATURES ALOFT AND OROGRAPHIC FORCING WILL AID IN THE THREAT OF ISOLATED THUNDERSTORMS. ...UPPER MIDWEST AND WESTERN GREAT LAKES... FAST MOVING UPPER JET MAX OVER MT/ND WILL TRACK EASTWARD ALONG THE US/CANADIAN BORDER TODAY. STEEP MID LEVEL LAPSE RATES AND UPPER FORCING WILL AID IN THE DEVELOPMENT OF MARGINAL ELEVATED INSTABILITY LATER TODAY. FORECAST SOUNDINGS IN THIS REGION SUGGEST SUFFICIENT CAPE ABOVE AN ELEVATED MIXED LAYER FOR A RISK OF ISOLATED THUNDERSTORMS. ACTIVITY MAY SPREAD INTO MI DURING THE EVENING. NO SEVERE STORMS ARE FORECAST. ..HART/BOTHWELL.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 16:28:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 11:28:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081629 SWODY1 SPC AC 081627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST WED NOV 08 2006 VALID 081630Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... COMPACT UPPER LOW WILL CONTINUE EWD ACROSS THE SERN STATES...WITH WEAK TROUGH EXTENDING NWD INTO THE NERN U.S. BEHIND THIS SYSTEM...UPPER RIDGE WILL EXIST ACROSS THE CNTRL/SRN PLAINS PROVIDING WARM AND DRY CONDITIONS. TO THE W...BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EWD ACROSS THE PACIFIC NW/NRN ROCKIES AS VORTICITY CENTER MOVES ASHORE LATER TODAY INTO WA/ORE. FINALLY...A LOW AMPLITUDE BUT POTENT UPPER TROUGH WILL SKIRT ALONG THE U.S./CANADA BORDER BRINGING A SLIM CHANCE OF A THUNDERSHOWER FROM NRN MN INTO THE WRN GREAT LAKES. ...MID ATLANTIC REGION... VERY COOL MID LEVEL TEMPERATURES EXIST WITHIN UPPER LOW CENTER...WITH -21.1 C AT FFC THIS MORNING AT 500 MB. POCKETS OF SURFACE HEATING ACROSS THE CAROLINAS MAY ALLOW FOR ENOUGH CONVECTIVE INSTABILITY TO DEVELOP FOR A FEW THUNDERSTORMS AS MAIN SURFACE LOW DEEPENS TO THE NE. ...PACIFIC NW... VERY COOL TEMPERATURES ALOFT/STEEP LAPSE RATES WILL EXIST AS STRONG TROUGH ENTERS THE REGION. SHORELINE CONVERGENCE WITH WEAK SURFACE TROUGH COMBINED WITH HEIGHT FALLS/COOLING ALOFT WILL SUPPORT SCATTERED STORMS OVER THE OCEAN AND LIKELY INLAND TO THE W SLOPES OF THE CASCADES. ..JEWELL/MCCARTHY.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 19:19:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 14:19:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081921 SWODY1 SPC AC 081918 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0118 PM CST WED NOV 08 2006 VALID 082000Z - 091200Z ...NO SVR TSTM AREAS FORECAST... THE SOUTHERN BRANCH CLOSED LOW IS BEGINNING TO LIFT OUT OF THE SOUTHEASTERN STATES. IN ITS WAKE...A SURFACE RIDGE OVER THE GULF OF MEXICO...AND BROAD RIDGING ALOFT...FROM THE FOUR CORNERS STATES THROUGH THE CENTRAL/SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY...ARE CONTRIBUTING TO A GENERALLY STABLY STRATIFIED ENVIRONMENT ACROSS MUCH OF THE NATION. A COUPLE AREAS WITH LIMITED CONVECTIVE POTENTIAL DO EXIST...BUT PROBABILITY OF THUNDERSTORMS EVEN IN THESE AREAS IS LOW. ...PACIFIC NORTHWEST/NORTHERN GREAT BASIN... ISOLATED/WIDELY SCATTERED THUNDERSTORMS ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL BE POSSIBLE THIS AFTERNOON FROM COASTAL AREAS INTO THE WESTERN SLOPES OF THE CASCADES...AS UPPER TROUGH PROGRESSES INLAND. ONSHORE FLOW IS GENERALLY WEAK...BUT BECOMING FOCUSED ACROSS THE OREGON COAST...WHERE BEST CHANCE FOR STORMS EXISTS. OTHERWISE...DESTABILIZATION HAS BECOME SUFFICIENT FOR WEAK THUNDERSTORM ACTIVITY IN A ZONE OF STRONGER FORCING ALONG FRONT NOW ADVANCING SLOWLY SOUTHWARD ACROSS THE NORTHERN INTERMOUNTAIN REGION INTO THE NORTHERN GREAT BASIN. ADDITIONAL WIDELY SCATTERED STORMS APPEAR POSSIBLE EASTWARD INTO SOUTHEASTERN IDAHO...WITH SOUTHWARD DEVELOPMENT THROUGH NORTH CENTRAL NEVADA/NORTHERN UTAH BY EARLY THIS EVENING EVENING...BEFORE ACTIVITY DIMINISHES WITH LOSS OF DAYTIME HEATING. ...UPPER GREAT LAKES... WEAK...MID-LEVEL BASED CONVECTION IS EVIDENT IN WARM ADVECTION REGIME SPREADING ACROSS PARTS OF LAKE SUPERIOR AND THE UPPER PENINSULA OF MICHIGAN...ASSOCIATED WITH A NORTHERN BRANCH SHORT WAVE TROUGH NEAR THE CENTRAL U.S./CANADIAN BORDER. AN ISOLATED WEAK THUNDERSTORM OR TWO STILL APPEARS POSSIBLE THIS AFTERNOON ...BEFORE FORCING SHIFTS OFF INTO SOUTHERN ONTARIO. ...ATLANTIC COAST... CONVECTIVE DEVELOPMENT IS ONGOING ACROSS PARTS OF SOUTHEAST VIRGINIA...WHERE THE BOUNDARY LAYER REMAINS MOIST AND WEAKLY UNSTABLE...ALTHOUGH THE SURFACE LOW IS NOW DEVELOPING EAST OF THE DELMARVA PENINSULA. UPPER FLOW REMAINS DIVERGENT ACROSS MID ATLANTIC COASTAL AREAS...AHEAD OF UPPER TROUGH AXIS PIVOTING OFF THE SOUTH ATLANTIC COAST...AND THIS COULD CONTRIBUTE TO ADDITIONAL ISOLATED THUNDERSTORMS LATE THIS AFTERNOON/EARLY THIS EVENING. OTHERWISE...THUNDERSTORMS REMAIN POSSIBLE LATER TODAY/TONIGHT IN LOW-LEVEL WARM ADVECTION REGIME LIFTING UP MIDDLE/NORTHERN ATLANTIC COASTAL AREAS...IN ADVANCE OF SURFACE CYCLONE. ..KERR.. 11/08/2006  From swody1 at goshenarc.org Thu Nov 9 00:50:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 19:50:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090052 SWODY1 SPC AC 090050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 PM CST WED NOV 08 2006 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A FEW AREAS OF ACTIVE BUT ISOLATED CONVECTION MAY PERSIST OVER THE NEXT FEW HOURS ACROSS THE CONUS. FROM WEST TO EAST...THE NEXT SHORT WAVE TROUGH MOVING ASHORE OVER THE PACIFIC NORTHWEST WILL CONTINUE TO ACT UPON MOIST ONSHORE LOW LEVEL FLOW TO PROMOTE A FEW SCATTERED TSTMS FROM THE COASTAL RANGES TO THE CASCADES. FROM THE NRN SIERRA RANGE ACROSS THE GREAT BASIN...LIFT AND WEAK INSTABILITY ALONG DEEP LAYER BAROCLINIC BAND WILL PROVIDE IMPETUS FOR A FEW LIGHTNING STRIKES OVER THE NEXT FEW HOURS. A FAST-MOVING IMPULSE EMBEDDED WITHIN NEARLY ZONAL FLOW ACROSS SCNTRL CANADA AND THE NRN PLAINS WILL CONTINUE TO TREK EAST ACROSS THE NRN GREAT LAKES TONIGHT. FORCING WITH THIS IMPULSE MAY SUPPORT ISOLATED CONVECTION ON THE NOSE OF LOW LEVEL WARM CONVEYOR BELT FROM NRN WI INTO THE NRN PARTS OF LOWER MI. FINALLY...STRONG ASCENT WITHIN DEFORMATION AXIS NORTH OF ERN CAROLINAS CLOSED LOW MAY CONTINUE TO CONTRIBUTE TO ISOLATED TSTMS ACROSS THE VA/NC CAPES TONIGHT. ..CARBIN.. 11/09/2006  From swody1 at goshenarc.org Thu Nov 9 05:57:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 09 Nov 2006 00:57:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090558 SWODY1 SPC AC 090556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST WED NOV 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE SHORT WAVE TROUGH...CURRENTLY MOVING OVER THE PACIFIC NORTHWEST...WILL CONTINUE TO TRACK ACROSS THE NRN GREAT BASIN THROUGH 12Z TODAY BEFORE MOVING ACROSS THE ROCKIES AND INTO THE NRN/CNTRL PLAINS BY 12Z FRIDAY. HEIGHT FALLS WITH THIS DISTURBANCE WILL CONTRIBUTE TO LEE CYCLOGENESIS OVER CO LATER TODAY. AS THE UPPER TROUGH SPREADS OVER THE PLAINS STATES LATER TONIGHT...THE ASSOCIATED SURFACE LOW PRESSURE AREA WILL REFORM ALONG A DEEP-LAYER BAROCLINIC ZONE BISECTING THE PLAINS FROM IA SWWD TO OK. ...INTERMOUNTAIN REGION... COLD AIR ALOFT ASSOCIATED WITH THE SHORT WAVE TROUGH EMANATING FROM THE PACIFIC NORTHWEST WILL CONTRIBUTE TO WEAK DESTABILIZATION /MUCAPE 100-200 J PER KG/ ACROSS PARTS OF NRN UT...WY...AND NWRN CO AREAS THIS AFTERNOON. WEAK CONVECTIVE DEVELOPMENT SHOULD ENSUE ACROSS THE HIGHER TERRAIN WHERE A FEW ISOLATED TO WIDELY SCATTERED TSTMS APPEAR POSSIBLE THROUGH EARLY EVENING. ...LOWER MO RIVER VALLEY... STRENGTHENING MOISTURE TRANSPORT AND LIFT IN ADVANCE OF THE APPROACHING TROUGH AND FRONTAL ZONE WILL CONTRIBUTE TO AN AXIS OF HIGHER THETA-E AIR AHEAD OF DEVELOPING SURFACE LOW FROM OK TO KS BY LATE TONIGHT. DESPITE INCREASING ISENTROPIC LIFT THROUGH LATE IN THE PERIOD ACROSS THIS AREA...WEAKER CAPPING AND STRONGER FORCING FOR ASCENT ARE FORECAST TO EXIST PRIMARILY NORTH OF THE RESULTING INSTABILITY AXIS...FROM NERN KS INTO SRN IA. LATEST GUIDANCE SUGGESTS FORCING AND DESTABILIZATION ALONG THE FRONTAL BAND AND AHEAD OF THE DEVELOPING SURFACE LOW WILL BE SUFFICIENT FOR CONVECTIVE INITIATION BY EARLY FRIDAY MORNING. THIS ACTIVITY WILL LIKELY EXIST ATOP A STABLE POST-FRONTAL ENVIRONMENT WHERE MUCAPE UP TO 500 J/KG AND STRONG SHEAR COULD CONTRIBUTE TO A VERY LOW PROBABILITY HAIL THREAT. GIVEN LATE IN THE PERIOD DEVELOPMENT AND SOME UNCERTAINTY IN DEGREE OF INSTABILITY...IT IS TOO EARLY TO INTRODUCE LOW SEVERE PROBABILITIES AT THIS TIME. ..CARBIN/LEVIT.. 11/09/2006  From swody1 at goshenarc.org Sat Nov 11 05:38:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 00:38:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110539 SWODY1 SPC AC 110537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 PM CST FRI NOV 10 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AN ACTIVE AND PROGRESSIVE MID/UPPER LEVEL WAVE TRAIN WILL CONTINUE INTO THE WEEKEND ACROSS THE U.S. AS ANOTHER STRONG TROUGH MOVES INLAND FROM THE INTERIOR NORTHWEST AND ACROSS THE ROCKIES...AND A COMPACT BUT POTENT SHORT WAVE TROUGH CLOSES OFF AND TAKES ON A NEGATIVE TILT FROM THE SRN APPALACHIANS ACROSS THE CAROLINAS/MID ATLANTIC. SYSTEM MOVING EAST FROM THE CNTRL U.S. EARLY TODAY IS EXPECTED TO UNDERGO FURTHER AMPLIFICATION AS IT EVOLVES INTO A CLOSED LOW BY LATE TONIGHT ACROSS THE SRN APPALACHIANS AND CAROLINAS. PRIMARY SURFACE LOW ASSOCIATED WITH THE STRONG UPPER TROUGH WILL START OUT THE PERIOD ACROSS THE ERN GREAT LAKES/PA/NY AREAS. WITH TIME... STRONG JET ENERGY MOVING THROUGH THE BASE OF THE UPPER TROUGH WILL INDUCE PRONOUNCED HEIGHT FALLS AND SECONDARY CYCLOGENESIS OVER THE MID ATLANTIC REGION THROUGH EARLY SUNDAY. THE COLD FRONT ACCOMPANYING THIS SYSTEM WILL EXTEND FROM OH TO LA THIS MORNING AND SHOULD REACH THE APPALACHIANS BY THIS EVENING. THE SRN SEGMENT OF THE FRONT IS FORECAST TO MOVE ACROSS THE SRN APPALACHIANS AND THEN SURGE OFF THE SOUTHEAST U.S COAST THROUGH SUNDAY MORNING AS DEEP-LAYER CYCLONE INTENSIFIES OVER ERN NC/VA. ...AL/GA ACROSS SRN/CNTRL APPALACHIANS...CAROLINAS/VA... A NARROW AXIS OF GREATER BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE 50S TO LOW 60S/ EXPECTED TO ADVECT NEWD AHEAD OF THE COLD FRONT FROM ERN AL...ACROSS GA...AND OVER PARTS OF THE WRN CAROLINAS THROUGH LATE TODAY. GENERALLY WEAK MID LEVEL LAPSE RATES ARE FORECAST TO LIMIT STRONGER DESTABILIZATION. HOWEVER...LIFT ALONG THE FRONT...AND INCREASINGLY STRONG DYNAMIC FORCING AND WIND FIELDS WITH THE APPROACHING UPPER TROUGH...SHOULD CONTRIBUTE TO THE DEVELOPMENT OF A NARROW LOW-TOPPED LINE OF CONVECTION THROUGH LATE EVENING FROM GA NNEWD TO VA. CONVECTION MAY BE MAINTAINED THROUGH THE NIGHT GIVEN STRONG CYCLOGENETIC FORCING FORECAST TO OCCUR ACROSS THE CAROLINAS AND VA. LACK OF GREATER INSTABILITY MAY BE OFFSET BY INCREASINGLY STRONG LIFT AND SHEAR TO SUPPORT AN ISOLATED SEVERE WIND GUST OR PERHAPS SOME MARGINALLY SEVERE HAIL. LOW SEVERE PROBABILITIES WILL BE MAINTAINED FOR THIS POTENTIAL. ...PACIFIC NORTHWEST... SHOWERS AND PERHAPS SOME EMBEDDED LIGHTNING APPEAR LIKELY AS WEAKLY UNSTABLE ONSHORE/UPSLOPE FLOW PERSISTS IN THE WAKE OF EWD-MOVING UPPER TROUGH. MOST LIKELY AREAS FOR ONSHORE THUNDER SHOULD BE LIMITED TO THE WINDWARD SLOPES OF THE OLYMPICS AND COASTAL RANGES. ..CARBIN/GRAMS.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 12:19:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 07:19:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111220 SWODY1 SPC AC 111218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST SAT NOV 11 2006 VALID 111300Z - 121200Z ...NO SVR TSTM AREAS FORECAST... TROUGH CURRENTLY MOVING ACROSS THE MID MS VALLEY IS PROGGED TO AMPLIFY TONIGHT CLOSING OFF AN UPPER LOW OVER THE CAROLINAS BY 12Z SUNDAY. COLD FRONT EXTENDS SWWD FROM THE SURFACE LOW OVER ERN OH VALLEY TO OFFSHORE TX COAST. BY TONIGHT A NEW SURFACE LOW WILL DEVELOP VA/NC AS UPSTREAM TROUGH INTENSIFIES. STRONG ASCENT TONIGHT AHEAD OF THIS SYSTEM WILL RESULT IN EXPANDING AREA OF PRECIPITATION CENTRAL APPALACHIANS EWD. WITH LITTLE GULF MOISTURE AVAILABLE OVER SERN U.S...INSTABILITY EXPECTED TO BE MEAGER AHEAD OF THE COLD FRONT AND TROUGH. WHILE SOME CONVECTION IS LIKELY...PARTICULARLY TONIGHT WITH THE INTENSIFYING UPPER SYSTEM...SEVERE STORMS NOT EXPECTED. ..HALES/GRAMS.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 16:28:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 11:28:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111630 SWODY1 SPC AC 111628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1028 AM CST SAT NOV 11 2006 VALID 111630Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... UPR TROUGH NOW OVER THE MID MS VLY EXPECTED TO AMPLIFY SUBSTANTIALLY TONIGHT/EARLY SUNDAY AS SYSTEM CONTINUES E/SE INTO NC/SRN VA. ASSOCIATED COLD FRONT NOW ALONG THE WRN SLOPES OF THE SRN APPALACHIANS SHOULD REACH WRN PARTS OF THE SW VA...NC AND SC PIEDMONT BY THIS EVENING...AND THE HATTERAS AREA BY 12Z SUNDAY...AS EXISTING SFC LOW FILLS OVER NW PA AND NEW CYCLOGENESIS OCCURS OVER TIDEWATER VA. WITH MAIN UPR JET STREAK/VORT MAX ASSOCIATED WITH MS VLY SYSTEM REMAINING WELL W OF SFC WARM SECTOR...MID LEVEL LAPSE RATES AND FORCING FOR ASCENT WILL REMAIN WEAK. THIS WILL LIMIT POTENTIAL FOR DEEP CONVECTION OVER THE CAROLINAS TODAY DESPITE UNINHIBITED SURFACE HEATING AND SHALLOW FRONTAL UPLIFT. LATER IN THE PERIOD...HOWEVER...DEEP FORCING FOR ASCENT LIKELY WILL OVERTAKE MOISTENING WARM SECTOR OVER FAR ERN NC AND PERHAPS TIDEWATER VA AS SECONDARY SFC CYCLONE STRENGTHENS. SATELLITE AND SFC OBSERVATIONS OFF THE S ATLANTIC CST ATTM SUGGEST THAT LOW LEVEL AIR MASS INVOLVED WILL BE OF MODIFIED POLAR CHARACTER...WITH A FAIRLY SHALLOW MODERATELY MOIST BOUNDARY LAYER /DEWPOINTS IN THE LOW 60S/. A BAND OR TWO OF CONVECTION/TSTMS MAY DEVELOP LATE IN THE PERIOD ALONG WRN EDGE OF MORE STRONGLY MODIFIED AIRMASS OVER EXTREME ERN NC AND THE ADJACENT CSTL WATERS NWD TO THE VA CAPES. WHILE ISOLATED STRONG WINDS WILL BE POSSIBLE WITH ANY SUCH ACTIVITY... UNFAVORABLE TIME OF DAY...WEAK LOW LEVEL LAPSE RATES AND LIMITED GEOGRAPHICAL AREA INVOLVED PRECLUDE ADDITION OF A SEVERE THREAT AREA ATTM. ..CORFIDI/GUYER.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 19:49:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 14:49:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111951 SWODY1 SPC AC 111949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SAT NOV 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC STATES... PRIMARY ZONE OF UPPER FORCING ASSOCIATED WITH AMPLIFYING MID/UPPER LEVEL TROUGH APPROACHING MID ATLANTIC REGION FROM THE LOWER OH/TN VALLEYS IS EXPECTED TO REMAIN WEST OF THE COLD FRONT THROUGH MUCH OF THIS FORECAST PERIOD. THUS...SHOWERS WITH EMBEDDED ELEVATED THUNDERSTORMS SHOULD REMAIN MAINLY POST-FRONTAL...WHILE WEAK LAPSE RATES/INSTABILITY PRECLUDE A SEVERE WEATHER THREAT. LATER TONIGHT /MOST LIKELY 09-12Z/...SURFACE CYCLOGENESIS IS PROGGED TO OCCUR OVER NERN NC TO THE VA TIDEWATER AREA IN RESPONSE TO STRONGER HEIGHT FALLS DEVELOPING EWD ACROSS THIS AREA AS THE CLOSED LOW EVOLVES OVER VA/NC BY 12Z SUNDAY. EARLY AFTERNOON SURFACE ANALYSIS SHOWED A COASTAL BOUNDARY EXTENDING SSW-NNE ACROSS FAR ERN NC TO FAR SERN VA WITH THE SURFACE LOW EXPECTED TO DEVELOP IN THE VICINITY OF THIS FRONT. SURFACE DEWPOINTS IN THE LOWER 60S EAST OF THIS BOUNDARY SHOULD SUPPORT WEAK INSTABILITY LATE TONIGHT...AND THE POTENTIAL FOR A BAND OR TWO OF CONVECTION/TSTMS. ALTHOUGH ISOLATED STRONG WIND GUSTS WOULD BE POSSIBLE WITH THIS ACTIVITY...TIME OF DAY...WEAK LOW LEVEL LAPSE RATES...AND LIMITED GEOGRAPHICAL AREA CONTINUE TO PRECLUDE ADDITION OF SEVERE WEATHER THREAT. ...SERN AL/FL PANHANDLE/SWRN GA... REGIONAL RADARS AND LIGHTNING DATA INDICATED THUNDERSTORMS HAVE DEVELOPED SINCE 1830Z ALONG THE COLD FRONT AS IT MOVED EWD INTO THE WRN FL PANHANDLE AND SERN AL. A NARROW MOIST AXIS EXTENDED NEWD INTO WRN GA AHEAD OF THE FRONT...SUPPORTING WEAK INSTABILITY. VEERED LOW LEVEL WINDS IN ADVANCE OF THIS BOUNDARY WILL CONTINUE TO LIMIT CONVERGENCE...WITH STORMS POTENTIALLY BECOMING UNDERCUT BY THE FRONT. WEAK INSTABILITY AND CONVERGENCE SHOULD MINIMIZE LIKELIHOOD FOR MORE ROBUST UPDRAFTS...DESPITE EFFECTIVE SHEAR VALUES OF 35-40 KT. A FEW WIND GUSTS WILL BE POSSIBLE...BUT OVERALL SEVERE WEATHER THREAT APPEARS TOO LOW TO INCLUDE SEVERE PROBABILITIES IN THIS OUTLOOK. ..PETERS.. 11/11/2006  From swody1 at goshenarc.org Sun Nov 12 00:45:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 19:45:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120046 SWODY1 SPC AC 120044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 PM CST SAT NOV 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MIDDLE ATLANTIC STATES SWD TO FL... INTENSE SHORT WAVE TROUGH OVER THE TN VALLEY IS FORECAST TO EVOLVE INTO A CLOSED MID-LEVEL LOW LATE TONIGHT AS IT TRANSLATES EWD INTO THE PIEDMONT REGION. IN THE LOW-LEVELS...SURFACE COLD FRONT ALONG THE APPALACHIANS WILL SHIFT EWD INTO THE PIEDMONT AND COASTAL PLAIN WITH SECONDARY CYCLOGENESIS OCCURRING ALONG THE FRONT OVER ERN NC LATE TONIGHT INTO SUNDAY MORNING. RADAR AND LIGHTNING DATA INDICATE RECENT INTENSIFICATION OF STORMS OVER WRN NC INTO SWRN VA...PRESUMABLY AS STRONGER LARGE-SCALE FORCING OVERSPREADS FRONTAL ZONE. 12/00Z REGIONAL SOUNDINGS INDICATE THAT MARGINAL BOUNDARY LAYER MOISTURE AND WEAK MID-LEVEL LAPSE RATES ARE LIMITING AIR MASS DESTABILIZATION...EXCEPT NEAR THE FRONT OVER THE FL PENINSULA WHERE SOME WEAK INSTABILITY WAS PRESENT. INTENSE LARGE-SCALE FORCING OWING TO DEEPENING SYNOPTIC SYSTEM SHOULD SUPPORT SOME AIR MASS DESTABILIZATION OVERNIGHT WITH ISOLATED TO WIDELY SCATTERED TSTMS FORECAST ALONG FRONTAL ZONE. SOME THREAT OF GUSTY WINDS AND/OR SMALL HAIL WILL EXIST WITH STRONGEST STORMS. HOWEVER...ANY MORE ORGANIZED SEVERE THREAT SHOULD REMAIN CONFINED TO REGION OF COMPARABLY STRONGER CONVECTIVE INSTABILITY ALONG THE GULF STREAM TOWARD THE END OF THE FORECAST PERIOD. ..MEAD.. 11/12/2006  From swody1 at goshenarc.org Sun Nov 12 05:14:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 12 Nov 2006 00:14:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120516 SWODY1 SPC AC 120514 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1114 PM CST SAT NOV 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID AND UPPER-LEVEL LOW OVER THE PIEDMONT REGION AT THE BEGINNING OF THE FORECAST PERIOD WILL SLOWLY SHIFT EWD INTO THE WRN ATLANTIC BY TONIGHT. MEANWHILE...A MORE PROGRESSIVE SHORT WAVE TROUGH /NOW OVER THE LOWER CO VALLEY/ WILL TRANSLATE EWD THROUGH THE CNTRL/SRN ROCKIES INTO THE PLAINS STATES LATER TODAY. IN THE LOW-LEVELS...SURFACE CYCLONE ATTENDANT TO ERN U.S. UPPER LOW IS FORECAST TO UNDERGO OCCLUSION AS IT SLOWLY DEVELOPS NEWD FROM NERN NC INTO THE ATLANTIC. ASSOCIATED COLD FRONT WILL PUSH EWD OFF THE NC COAST EARLY IN THE PERIOD. TO THE W...PACIFIC COLD FRONT /INITIALLY FROM THE ERN DAKOTAS INTO CNTRL HIGH PLAINS/ WILL PUSH SEWD THROUGH THE MO VALLEY AND CNTRL INTO SRN PLAINS. ...SRN NEW ENGLAND SWD THROUGH THE TIDEWATER TO ERN NC... CLUSTERS OF TSTMS MAY BE ONGOING AT THE ONSET OF THE FORECAST PERIOD ALONG COLD FRONT AND INVOF DEEPENING CYCLONE OVER ERN NC WITHIN ZONE OF STRONG DEEP LAYER FORCING FOR ASCENT. MARGINAL BOUNDARY LAYER MOISTURE AND LAPSE RATES WILL LIMIT THE DEGREE OF INSTABILITY WITHIN PREFRONTAL AIR MASS ACROSS ERN NC AND THE OUTER BANKS. SOME POTENTIAL WILL EXIST FOR A FEW STRONG STORMS CAPABLE OF GUSTY WINDS/SMALL HAIL THROUGH THE MORNING HOURS OWING TO THE INTENSE FORCING AND RELATIVELY STRONG WIND FIELDS. HOWEVER...THE GREATER SEVERE THREAT SHOULD REMAIN OFFSHORE...NEARER TO THE GULF STREAM. OTHER ISOLATED STORMS WILL BE POSSIBLE N AND NW OF OCCLUDING SYNOPTIC SYSTEM ALONG THE MIDDLE ATLANTIC AND SRN NEW ENGLAND COASTS AS STRONG LOW-LEVEL WAA CONTRIBUTES TO AIR MASS DESTABILIZATION AND WEAK ELEVATED CONVECTIVE INSTABILITY. ...PACIFIC NW COAST... A SIMILAR ENVIRONMENT TO CURRENT IS FORECAST TO PERSIST THROUGH THE MORNING HOURS AS MOIST ONSHORE FLOW AND RELATIVELY COLD MID-LEVEL TEMPERATURES CONTRIBUTE TO A WEAKLY UNSTABLE ENVIRONMENT. TSTM POTENTIAL SHOULD TEND TO DIMINISH LATER TODAY AS LOW-LEVEL WIND FIELDS BACK IN RESPONSE TO THE APPROACH OF THE NEXT SYNOPTIC SYSTEM FROM THE NERN PACIFIC. ..MEAD/GRAMS.. 11/12/2006  From swody1 at goshenarc.org Mon Nov 20 00:42:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 19 Nov 2006 19:42:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200045 SWODY1 SPC AC 200043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0643 PM CST SUN NOV 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...OLYMPIC PENINSULA... STRONG HEIGHT FALLS ARE FORECAST ACROSS REGION TONIGHT AS INTENSE MID AND UPPER-LEVEL JET STREAKS DEVELOP SEWD FROM THE FAR ERN PACIFIC AND BRITISH COLUMBIA INTO WA AND ORE. 20/00Z UIL SOUNDING INDICATES THAT RELATIVELY STEEP 0-3 KM AGL LAPSE RATES ARE CONTRIBUTING TO A WEAKLY UNSTABLE ENVIRONMENT WITH MUCAPES OF 100-200 J/KG AND EQUILIBRIUM LEVEL TEMPERATURES OF AROUND -19 TO -20 C. FURTHER DESTABILIZATION IS EXPECTED OVERNIGHT AS HEIGHT FALLS/DYNAMIC COOLING ON CYCLONIC SIDE OF MID-LEVEL JET STREAK INCREASE FROM THE NW. AS SUCH...EXPECT ISOLATED TSTM ACTIVITY /PER OCEANIC LIGHTNING DATA/ CURRENTLY 100-120 NM OFFSHORE TO GRADUALLY MOVE/DEVELOP INLAND LATER TONIGHT. ..MEAD.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 05:20:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 00:20:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200523 SWODY1 SPC AC 200521 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 PM CST SUN NOV 19 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... AMPLIFIED...FULL LATITUDE TROUGH WILL PERSIST ACROSS ERN PARTS OF CANADA AND THE U.S. THIS PERIOD WHILE IN THE W...A BELT OF STRONG...MID AND UPPER LEVEL CYCLONIC FLOW WILL EXIST FROM THE ERN PACIFIC INTO THE NRN PLAINS AND S-CNTRL CANADA. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS INTENSIFYING SRN BRANCH OF ERN U.S. TROUGH AND ATTENDANT SURFACE LOW OVER THE GULF STREAM WILL LIKELY FOCUS THE MAJORITY TSTM DEVELOPMENT THIS FORECAST OFF THE SERN ATLANTIC COAST. OTHER MORE ISOLATED TSTM ACTIVITY MAY OCCUR ALONG THE WA/ORE COASTS...ESPECIALLY OVERNIGHT...AS NEXT STRONG SHORT WAVE TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM APPROACH FROM THE W. HERE...INCREASED LARGE-SCALE FORCING AND RESULTANT STEEPENING OF LAPSE RATES WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR A FEW STORMS EMBEDDED WITHIN FRONTAL PRECIPITATION BAND. ..MEAD/BOTHWELL.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 12:30:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 07:30:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201233 SWODY1 SPC AC 201231 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 AM CST MON NOV 20 2006 VALID 201300Z - 211200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED...FULL LATITUDE TROUGH WILL PERSIST ACROSS ERN PARTS OF CANADA AND THE U.S. THIS PERIOD WHILE IN THE W...A BELT OF STRONG...MID AND UPPER LEVEL CYCLONIC FLOW WILL EXIST FROM THE ERN PACIFIC INTO THE NRN PLAINS AND S-CNTRL CANADA. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS INTENSIFYING SRN BRANCH OF ERN U.S. TROUGH AND ATTENDANT SURFACE LOW OVER THE GULF STREAM WILL LIKELY FOCUS THE MAJORITY TSTM DEVELOPMENT THIS FORECAST OFF THE SERN ATLANTIC COAST. OTHER MORE ISOLATED TSTM ACTIVITY MAY OCCUR ALONG THE WA/ORE COASTS...ESPECIALLY OVERNIGHT...AS NEXT STRONG SHORT WAVE TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM APPROACH FROM THE W. HERE...INCREASED LARGE-SCALE FORCING AND RESULTANT STEEPENING OF LAPSE RATES WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR A FEW STORMS EMBEDDED WITHIN FRONTAL PRECIPITATION BAND. ..EVANS/MEAD.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 16:28:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 11:28:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201632 SWODY1 SPC AC 201629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST MON NOV 20 2006 VALID 201630Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SERN ATLANTIC COAST... A LONGWAVE TROUGH WILL CONTINUE TO PERSIST ACROSS THE ERN CONUS THROUGH TONIGHT WITH EVENTUAL DEVELOPMENT OF A CLOSED LOW OVER NRN FL BY 12Z TUE. ATTENDANT SFC LOW ALREADY EVIDENT IN BUOY STREAMLINE ANALYSIS OFF THE SC/GA COASTS WILL INTENSIFY. INTENSIFYING CONVEYOR BELT ON THE NWRN PERIPHERY OF THIS DEVELOPING CYCLONE WILL WRAP MOISTURE IN THE MID-UPPER LEVELS FROM THE GULF STREAM WWD TO THE SERN ATLANTIC COAST BY 12Z TUE. MOST SUBSTANTIAL DESTABILIZATION AND TSTM PROBABILITIES SHOULD REMAIN OFFSHORE...HOWEVER. ...COASTAL WA/ORE... WEAK MID-LEVEL SHORTWAVE TROUGH CONTINUES TO MIGRATE NEWD ACROSS CNTRL WA THIS MORNING. IN WAKE OF THIS IMPULSE...THERE WILL BE A BRIEF PERIOD OF WARMING AND RIDGING ALOFT THROUGH THIS EVE. NEXT DISTURBANCE...NOW LOCATED NEAR 40N/140W WILL BE APPROACHING THE COAST BY 12Z TUE WITH STRONG LOW/MID-LEVEL FRONTOGENESIS JUST OFFSHORE. COLD/UNSTABLE AIR MASS ALREADY IN PLACE JUST OFFSHORE COMBINED WITH STRONG MESOSCALE LIFT WILL RESULT IN AN UPSWING IN TSTM PROBABILITIES ALONG COASTAL WA/ORE LATER TONIGHT AS THE FRONT APPROACHES. ..RACY/TAYLOR.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 19:57:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 14:57:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 202001 SWODY1 SPC AC 201958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON NOV 20 2006 VALID 202000Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SYNOPTIC PATTERN IN MID-UPPER LEVELS FEATURES HIGH-AMPLITUDE TROUGH OVER ERN CONUS...AND RIDGING FROM NRN MEX NEWD ACROSS UPPER MIDWEST AND UPPER MS VALLEY. SRN STREAM FLOW OVER SERN CONUS IS EXPECTED TO BEGIN CUTTING OFF BY END OF PERIOD AS STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER N-CENTRAL GULF AND SERN LA -- PIVOTS EWD AND PHASES WITH ANOTHER TROUGH OVER SRN APPALACHIANS. BY 21/12Z...RESULT SHOULD BE CLOSED CYCLONE COVERING GA...NERN GULF AND FL PANHANDLE. AS THIS OCCURS...SFC LOW ALREADY EVIDENT OFFSHORE SC IS EXPECTED TO DEEPEN IN PLACE. MEANWHILE...BROAD FETCH OF SWLY FLOW ALOFT WILL CONTINUE ACROSS MUCH OF W COAST AND NRN CONUS...W OF MEAN RIDGE. ...SERN CONUS... WRN EDGE OF LARGELY MARITIME TSTM POTENTIAL WILL BRUSH COASTAL AREAS OF SC/NC THROUGH REMAINDER PERIOD...IN ASSOCIATION WITH STRENGTHENING LOW LEVEL WAA AND FRONTAL ASCENT. FAVORABLY HIGH-THETAE SURFACE AIR MASS IN SERN SECTOR OF SFC CYCLONE -- AND OVER ENHANCED HEAT/MOISTURE FLUXES OF GULF STREAM -- WILL BE LIFTED ABOVE OFFSHORE WARM FRONTAL ZONE AND ADVECTED WWD IN ELEVATED WARM CONVEYOR. THIS WILL DESTABILIZE AIR MASS ENOUGH TO RESULT IN ELEVATED MUCAPES UP TO ABOUT 250 J/KG DURING OVERNIGHT HOURS. ...PACIFIC NW... EPISODES OF TSTMS ARE POSSIBLE OVER COASTAL/OFFSHORE WATERS...SOME OF WHICH MAY MOVE INLAND BEFORE WEAKENING. THIS WILL OCCUR IN RESPONSE TO PERIODS OF LOW-MIDLEVEL DESTABILIZATION IN AN ENVIRONMENT OF WEAK CINH AND MRGL LOW LEVEL THETAE...RESULTING IN MUCAPES 100-300 J/KG ALONG COAST. IN ADDITION...LOW LEVEL FRONTOGENETIC FORCING LATE TONIGHT MAY CONCENTRATE TSTM POTENTIAL ALONG ASSOCIATED AREA OF ENHANCED LIFT. ..EDWARDS.. 11/20/2006  From swody1 at goshenarc.org Tue Nov 21 00:32:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 19:32:44 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210036 SWODY1 SPC AC 210033 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 PM CST MON NOV 20 2006 VALID 210100Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SERN ATLANTIC COAST... CLUSTERS OF TSTMS ARE ONGOING THIS EVENING OFF THE CAROLINA COASTS...LARGELY DRIVEN BY RESPONSE TO FRONTOGENESIS IN THE 850 MB LAYER /PER RUC OBJECTIVE FIELDS/. HEAT AND MOISTURE FLUXES ALONG THE GULF STREAM SHOULD MAINTAIN AT LEAST WEAK INSTABILITY OVERNIGHT INVOF OF THIS INTENSIFYING BOUNDARY AND ATTENDANT LOW LEVEL CIRCULATION /SITUATED APPROXIMATELY 100 NM SE CHS/. SOME OF THIS ACTIVITY COULD APPROACH THE COAST LATER TONIGHT AS PORTION OF BAROCLINIC ZONE N OF SURFACE LOW PIVOTS SLIGHTLY WWD. ADDITIONAL STORMS MAY DEVELOP SWD FROM ONGOING ACTIVITY TO JUST OFF THE GA COAST AS STRONG SHORT WAVE TROUGH NOW OVER THE FAR NERN GULF OF MEXICO TRANSLATES EWD AND INTERACTS WITH THE WEAKLY UNSTABLE ENVIRONMENT. ...WA/ORE COASTS... WATER VAPOR IMAGERY INDICATES NEXT UPSTREAM SHORT WAVE TROUGH NEAR 42N AND 129W...WHICH LATEST MODEL GUIDANCE TAKES ONTO THE COAST BY 21/12Z. 21/00Z UIL/SLE SOUNDINGS INDICATE RELATIVELY STEEP LAPSE RATES --7 C/KM-- IN THE LOWEST 3.5 KM AGL WITH VERY MARGINAL CONVECTIVE INSTABILITY. FURTHER STEEPENING OF LAPSE RATES IS FORECAST OVERNIGHT WITH THE APPROACH OF THIS SHORT WAVE TROUGH WITH SUFFICIENT INSTABILITY DEVELOPING FOR ISOLATED...EMBEDDED TSTMS ALONG THE COAST /SIMILAR TO WHAT IS BEING OBSERVED JUST AHEAD OF VORTICITY MAXIMUM NEAR 43.5N AND 127W AS OF 0030Z/. ..MEAD.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 05:24:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 00:24:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210527 SWODY1 SPC AC 210525 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 PM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... INTENSE MID AND UPPER LOW EVOLVING OVER SRN GA/FL PNHDL INTO THE NERN GULF OF MEXICO WILL CONSTRICT SLIGHTLY AS IT SLOWLY SHIFTS EWD OFF THE FL ATLANTIC COAST. IN THE W...A BROAD BELT OF CYCLONIC FLOW WILL EXIST IN THE MID LEVELS FROM THE ERN PACIFIC INTO THE NRN ROCKIES. SHORT WAVE TROUGH EMBEDDED WITHIN THIS REGIME NOW APPROACHING THE WA/ORE COAST WILL TRANSLATE EWD INTO THE NRN ROCKIES BY TONIGHT WHILE NEXT UPSTREAM IMPULSE DIGS SEWD FROM THE GULF OF AK TO OFF THE PACIFIC NW COAST BY WEDNESDAY MORNING. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO FL UPPER LOW WILL REMAIN QUASI-STATIONARY OVER THE GULF STREAM WHILE GRADUALLY UNDERGOING OCCLUSION. WELL TO THE NW...LEE CYCLONE IS FORECAST TO INTENSIFY OVER ALBERTA INTO SASKATCHEWAN IN RESPONSE TO APPROACH OF LEAD SHORT WAVE TROUGH THROUGH THE NRN ROCKIES. LOW-LEVEL ONSHORE FLOW WILL CONCURRENTLY INCREASE ALONG THE PACIFIC NW COAST...IN WAKE OF BAROCLINIC ZONE INTENSIFYING FROM THE LOW OVER THE CANADIAN HIGH PLAINS SWWD INTO ERN ORE. ...SRN ATLANTIC COAST... LOW-LEVEL BAROCLINIC ZONE N AND NW OF SURFACE LOW IS EXPECTED TO REMAIN OVER THE SHELF WATERS WITH RESPONSE TO FRONTOGENESIS AND LOW-LEVEL WAA MAINTAINING ISOLATED/SCATTERED STORMS ALONG THIS BOUNDARY. FORECAST SOUNDINGS SUGGEST THAT ANY STORMS DEVELOPING ALONG THE IMMEDIATE COAST WILL LIKELY REMAIN ELEVATED AND BASED AROUND 850 MB WITHIN WEAKLY UNSTABLE ENVIRONMENT WITH MUCAPES OF AROUND 100 J/KG. ...NRN ROCKIES... INCREASED HEIGHT FALLS ASSOCIATED WITH SHORT WAVE TROUGH MOVING THROUGH WA/ORE ARE EXPECTED TO CONTRIBUTE TO STEEPENING LAPSE RATES AND DEVELOPMENT OF WEAK CONVECTIVE INSTABILITY LATER TODAY INTO TONIGHT. ISOLATED TSTMS EMBEDDED IN SHALLOWER CONVECTION WILL BECOME INCREASINGLY LIKELY AT THIS TIME ALONG STRENGTHENING LOW LEVEL BAROCLINIC ZONE THAT WILL STRETCH FROM WRN MT INTO ERN ORE. ...PACIFIC NW COAST... MOIST ONSHORE FLOW IN THE LOW LEVELS BENEATH COLD MID LEVEL TEMPERATURES OF AROUND -30 C AT 500 MB WILL RESULT IN RATHER STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. IT APPEARS THE BEST POTENTIAL FOR ISOLATED TSTM ACTIVITY WILL EXIST THIS MORNING IN ASSOCIATION WITH LEAD SHORT WAVE TROUGH...AND TOWARD THE END OF THE PERIOD WEDNESDAY MORNING AS NEXT UPSTREAM SYSTEM APPROACHES FROM THE W. ..MEAD/BOTHWELL.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 12:40:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 07:40:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211244 SWODY1 SPC AC 211241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 AM CST TUE NOV 21 2006 VALID 211300Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...PAC NW COAST INTO THE NRN SIERRAS AND NRN ROCKIES... 12Z SOUNDINGS AND EARLY MORNING LIGHTNING DETECTION NETWORK INDICATE ISOLATED THUNDERSTORMS WILL LIKELY CONTINUE THIS MORNING ALONG THE PAC NW COAST AND WITHIN BROAD MID LEVEL MOISTURE PLUME INTO THE NRN SIERRAS. STRONG MID/UPPER LEVEL TROUGH WILL PERSIST ALONG AND JUST OFF THE PAC NW COAST THROUGH THE PERIOD WITH SHORTWAVE TROUGH NOW APPROACHING THE COAST LIFTING ENEWD INTO THE NRN ROCKIES AS ANOTHER VORT MAX DIGS SSEWD OUT OF THE GULF OF AK. PERSISTENT ONSHORE FLOW AND STEEP LOW TO MID LEVEL LAPSE RATES SHOULD MAINTAIN ISOLATED THUNDERSTORMS ALONG AND WEST OF THE COASTAL RANGE IN WRN WA/ORE. ELSEWHERE...MOIST CONVECTION AND POSSIBLY ISOLATED THUNDERSTORMS SHOULD DEVELOP ALONG AND AHEAD OF SHORTWAVE TROUGH AND ASSOCIATED PAC COLD FRONT FORECAST TO OVERSPREAD THE NRN ROCKIES LATER TODAY AND TONIGHT. ...SERN U.S. COAST... INTENSE LOW SYSTEM WILL REMAIN IN PLACE JUST OFF THE GA/FL/SC COAST THROUGH THE PERIOD. DEEPER CONVERGENCE AND GREATER INSTABILITY WILL REMAIN OVER THE GULF STREAM AND SUPPORT SCATTERED THUNDERSTORMS JUST OFF THE COAST. HOWEVER...SUFFICIENT MID LEVEL COOLING IS EXPECTED TO SUSTAIN NARROW WEDGE OF ELEVATED INSTABILITY AND POTENTIAL FOR AN ISOLATED THUNDERSTORM OR TWO ACROSS COASTAL SC INTO ERN NC TODAY AND TONIGHT. ..EVANS.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 16:16:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 11:16:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211619 SWODY1 SPC AC 211617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1017 AM CST TUE NOV 21 2006 VALID 211630Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AMPLIFIED UPPER AIR PATTERN OVER CENTRAL/ERN CONUS WILL CONTINUE THROUGH PERIOD...WITH PRONOUNCED RIDGING FROM NRN MEX NEWD ACROSS MID/UPPER MS VALLEY. DOWNSTREAM...ANOMALOUSLY DEEP CYCLONE ALOFT -- CHARACTERIZED BY 90M/12H 500 MB HEIGHT FALLS TO ITS S AT EYW -- IS FCST TO MEANDER SLOWLY ACROSS NRN FL TOWARD ATLANTIC WATERS OFFSHORE GA. AS THIS OCCURS...ASSOCIATED LOW LEVEL CYCLONE WILL PROCEED DEEPER INTO OCCLUSION PROCESS...BECOMING PROGRESSIVELY MORE VERTICALLY STACKED WITH RESPECT TO MID/UPPER VORTEX. FARTHER NW...SERIES OF SHORTWAVE TROUGHS WILL PIVOT EWD AND NEWD AROUND NERN PACIFIC UPPER LOW...FROM COASTAL WA/ORE NEWD ACROSS INTERIOR WA AND SRN BC. MAIN PERTURBATION -- INDICATED BY MOISTURE CHANNEL IMAGERY INVOF WA COAST AND JUST OFFSHORE ORE -- IS EXPECTED TO DEAMPLIFY AS IT MOVES INLAND THROUGH REMAINDER PERIOD. ASSOCIATED LOW LEVEL FRONT -- NOW EVIDENT FROM NRN CASCADES SSWWD ACROSS NWRN CA -- LIKEWISE SHOULD WEAKEN AS IT MOVES INLAND. THOUGH SEVERAL AREAS OF MRGL GEN TSTM POTENTIAL EXIST WITH THESE REGIMES...INSTABILITY WILL REMAIN TOO WEAK FOR ORGANIZED SVR POTENTIAL. ...NWRN CONUS... POTENTIAL LINGERS FOR ISOLATED TSTMS WITHIN PORTIONS OF LOW LEVEL WAA PLUME AND CORRESPONDING BELT OF LOW-MIDLEVEL MOISTURE TRANSPORT -- FROM NRN CA NEWD ACROSS NRN ROCKIES. AS SHORTWAVE TROUGH NOW NEAR COAST MOVES INLAND...FAVORABLE LARGE SCALE ASCENT AND TSTM POTENTIAL IN WARM CONVEYOR EACH SHOULD WEAKEN FROM SW-NE...ENDING OVER NRN CA AREA WITHIN NEXT 3-4 HOURS BUT PERSISTING EPISODICALLY OVER PORTIONS INTERIOR NW AND NRN ROCKIES INTO EARLY TONIGHT. MEANWHILE...RELATIVELY STEEP LAPSE RATES AND MINIMAL CINH WILL HELP TO SUPPORT RISK OF ISOLATED TO WIDELY SCATTERED...SHALLOW...POSTFRONTAL TSTMS ACROSS COASTAL AREAS OF WA/ORE. IN THIS REGIME...CHARACTERIZED BY 500 MB TEMPS TO AROUND -30 C...MUCAPES MAY REACH TO NEAR 300 J/KG WITH BUOYANCY VERTICALLY EXTENDING INTO FAVORABLE ICING LAYERS FOR LIGHTNING PRODUCTION. ...SRN ATLANTIC COASTAL REGION... AS DEEP-LAYER CYCLONE MEANDERS OFFSHORE GA COAST...LOW LEVEL FRONTAL FORCING AND WAA CONVEYOR WILL WRAP AROUND NRN/WRN SECTORS OF THIS SYSTEM. EXPECT FAVORABLE MOISTURE...ELEVATED INSTABILITY AND LIFT TO SUPPORT ISOLATED TSTMS OVER COASTAL AREAS...BECOMING MORE COMMON OFFSHORE WHERE OCEANIC HEAT FLUXES WILL CONTRIBUTE TO LOW LEVEL BUOYANCY. ..EDWARDS/GRAMS.. 11/21/2006 WWWW From swody1 at goshenarc.org Tue Nov 21 19:58:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 14:58:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212000 SWODY1 SPC AC 211958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST TUE NOV 21 2006 VALID 212000Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...ERN CAROLINAS... MARINE FRONT SEEMS TO HAVE MOVED WWD TOWARD THE NC OUTER BANKS PER BUOY 41025 WHERE A WIND SHIFT TO ELY OCCURRED AND TEMPERATURE/DEW POINTS HAVE CLIMBED DURING THE PAST FEW HOURS. MAINTENANCE OF STRONG ISENTROPIC LIFT ON THE COLD SIDE OF THE CYCLONE SHOULD CONTINUE TO STRENGTHEN THE BAROCLINIC ZONE...PREVENTING THE MARINE BOUNDARY LAYER /MORE UNSTABLE ENVIRONMENT/ FROM REACHING THE OUTER BANKS. AS SUCH...NO ORGANIZED SEVERE WEATHER IS ANTICIPATED. BUT...SPORADIC TSTMS ARE LIKELY INLAND WITHIN THE ENHANCED MESOSCALE BANDS ALONG NWRN SIDE OF THE MATURING CYCLONE. SATL INDICATES THAT THE NEXT LOBE OF VORTICITY WILL ROTATE NWD INTO PRIMARILY ERN NC DURING THE EVENING. THIS WILL LIKELY ENHANCE THE MID-LEVEL FRONTOGENETIC RESPONSE AND TSTM PROBABILITIES. FURTHER DETAILS CAN BE FOUND IN NEWLY ISSUED MESOSCALE DISCUSSION 2229. ...PAC NW... CONSIDERABLE OPEN-CELL CUMULIFORM CLOUD TEXTURES ARE EVIDENT ON VSBL SATL IMAGERY OFFSHORE WA/ORE WITHIN CYCLONIC FLOW REGIME SITUATED ACROSS THE PAC NW. A FEW LIGHTNING STRIKES CONTINUE ALONG/W OF THE COASTAL RANGES AND THIS WILL LIKELY BE THE CASE THROUGH THIS EVENING. TSTM CHANCES SHOULD HAVE PEAKED AS SLIGHT WARMING OCCURS ALOFT AHEAD OF THE NEXT DISTURBANCE EXPECTED TO ARRIVE ONSHORE ON WED. OTHERWISE...ISOLD TSTMS MAY STILL BE POSSIBLE ACROSS THE NRN INTERMOUNTAIN WEST AHEAD OF A WEAK UPPER DISTURBANCE PASSING ACROSS THE REGION. ..RACY.. 11/21/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 00:42:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 19:42:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220042 SWODY1 SPC AC 220039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST TUE NOV 21 2006 VALID 220100Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ATLANTIC COAST... EVENING WATER VAPOR IMAGERY SHOWS ANOMALOUSLY INTENSE UPPER LOW CENTERED JUST OFF THE COAST OF NRN FL/GA WITH STRONG VORTICITY MAXIMUM ROTATING NNWWD AROUND THE ERN/NERN PERIPHERY OF THIS LOW. DEEP-LAYER FORCING FOR ASCENT...COMPRISED OF DPVA AND LOW-LEVEL WAA...ARE CONTRIBUTING TO EMBEDDED SCATTERED TSTMS FROM NEAR CRE TO OAJ AS OF 0000Z. THE MAJORITY OF THIS STORM ACTIVITY IS OCCURRING NEAR AND W OF LOW-LEVEL BAROCLINIC ZONE LOCATED JUST OFF THE OUTER BANKS WITHIN WEAKLY UNSTABLE ENVIRONMENT FOR ELEVATED PARCELS WITH MUCAPES OF 200-300 J/KG AS OBSERVED BY 22/00Z MHX SOUNDING. EXPECT THAT THE ONGOING LOW-LEVEL WAA WILL LIKELY CONTINUE TO BE THE PRIMARY FORCING MECHANISM TO MAINTAIN ISOLATED TO SCATTERED TSTMS OVERNIGHT MAINLY ALONG THE IMMEDIATE COAST. ...PACIFIC NW COAST TO NRN INTERMOUNTAIN REGION... ISOLATED TSTMS HAVE BEEN OBSERVED THIS AFTERNOON AND EARLY EVENING OVER CNTRL PARTS OF ID IN ASSOCIATION WITH LEAD SHORT WAVE TROUGH TRANSLATING THROUGH THE NRN ROCKIES. 22/00Z BOI SOUNDING SHOWS THAT STEEP LOW TO MID-LEVEL LAPSE RATES ARE LARGELY CONTRIBUTING TO POCKETS OF WEAK INSTABILITY /MUCAPES OF 200-300 J PER KG/. TSTMS SHOULD TEND TO DIMINISH LATER THIS EVENING AS BOUNDARY LAYER COOLS AND LAPSE RATES WEAKEN. FARTHER TO THE W...MOIST ONSHORE FLOW IN THE LOW-LEVELS COUPLED WITH COLD MID-LEVEL TEMPERATURES /-32 C AT 500 MB/ ARE CONTRIBUTING TO STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY /PER 22/00Z UIL/SLE SOUNDINGS/. WATER VAPOR IMAGERY SUGGESTS THAT NEXT UPSTREAM SHORT WAVE TROUGH IS ABOUT 100 NM W OF OTH WITH SOME OCEANIC LIGHTNING ACTIVITY OBSERVED WITH THIS FEATURE. EXPECT THAT THE THREAT OF ISOLATED...EMBEDDED TSTMS WILL INCREASE ALONG THE COAST WITH THE ARRIVAL OF THIS IMPULSE LATE TONIGHT. SOME SMALL HAIL/GRAUPEL MAY ACCOMPANY THE STRONGER CELLS...THOUGH THE MARGINAL INSTABILITY WILL LIMIT ANY SEVERE THREAT. ..MEAD.. 11/22/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 05:00:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 00:00:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220503 SWODY1 SPC AC 220501 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 PM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A STRONG AND COMPACT UPPER LOW WILL SLOWLY LIFT NEWD ALONG THE SERN COAST THROUGH THE PERIOD. AHEAD OF THIS FEATURE...A SFC FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ALONG THE OUTER BANKS NWD JUST OFF THE MID ATLANTIC COAST OF NJ. THE COMBINATION OF MODEST VERTICAL MOTION AND INSTABILITY SHOULD SUPPORT ISOLATED TO SCATTERED TSTMS ALONG AND EAST OF THIS BOUNDARY THROUGH TONIGHT. ELSEWHERE ACROSS THE NATION...WARM AND MILD CONDITIONS CAN BE EXPECTED ACROSS THE PLAINS STATES UNDER THE INFLUENCE OF MID/UPPER RIDGING. FURTHER WEST...ANOTHER STRONG UPPER TROUGH WILL MOVE INTO THE PAC NW DURING THE DAY AND INTO THE NRN ROCKIES WED NIGHT. THE COMBINATION OF MODEST UPSLOPE FLOW AND COLD MID LEVEL TEMPERATURES WILL SUPPORT ISOLATED TSTMS OVER WRN WA/ORE AS WELL AS PORTIONS OF THE NRN ROCKIES. ...OUTER BANKS OF NC... THE FRONTAL BOUNDARY PRESENTLY DRAPED ACROSS THE AREA WILL REMAIN NEARLY STATIONARY THROUGH DAYTIME HRS AS THE SFC/UPPER LOW MOVES SLOWLY NNEWD. COLDER MID LEVEL TEMPERATURES /-22 DEG C AT 500 MB/ LOCATED OFF THE EAST COAST OF FLA EARLY THIS MORNING WILL ROTATE ACROSS THE AREA DURING PEAK HEATING. SUFFICIENT INSTABILITY /MUCAPE FROM 500-750 J/KG/ COUPLED WITH LOW-MID LEVEL MODERATE VERTICAL MOTION EAST OF THE STATIONARY BOUNDARY SHOULD SUPPORT ISOLATED/SCT TSTM DEVELOPMENT. DESPITE THE PRESENCE OF A MID LEVEL DRY SLOT OVER THE REGION...THERE SHOULD BE WIDESPREAD LOW CLOUD COVER GIVEN THE MOIST LOW LEVEL WARM ADVECTION PROFILE. IF LESS LOW CLOUD COVER DEVELOPS THAN PRESENTLY EXPECTED...SLIGHTLY GREATER INSTABILITY /MUCAPES OVER 1000 J/KG/ WOULD BE REALIZED SUPPORTING MARGINALLY SVR HAIL IN THE STRONGEST TSTMS. GIVEN THE LOW CONFIDENCE IN THIS SCENARIO...WE WILL NOT INTRODUCE 5 PERCENT HAIL PROBS FOR THIS AREA ATTM. ...PAC NW/NRN ROCKIES... A LARGE POCKET OF COLD MID LEVEL TEMPERATURES...EVIDENT BY VIS/IR SATELLITE IMAGERY...EXISTED SEVERAL HUNDRED MILES OFF THE PAC NW COAST. THIS AREA WAS IN ASSOCIATION WITH A STRONG UPPER LOW/VORT LOBE ROTATING AROUND A BROADER UPPER TROUGH LOCATED OVER THE NERN PACIFIC. AS THIS VORT LOBE/TROUGH MOVES TOWARDS THE PAC NW COAST DURING THE AFTERNOON...SUFFICIENTLY STRONG UPSLOPE FLOW COMBINED WITH STEEPENING MID LEVEL LAPSE RATES /7.5-8 DEG C/KM/ WILL SUPPORT SCATTERED TSTMS OVER PORTIONS OF WRN ORE/WA. ALONG WITH LOW WBZ HEIGHTS...SUB-SVR SMALL HAIL/GRAUPEL IS POSSIBLE WITH THE STRONGEST TSTMS IN LOWER ELEVATIONS. DESPITE BEING AFTER DARK...ISOLATED TSTMS ARE ALSO POSSIBLE IN THE STRONG UPSLOPE REGIME/STEEP LAPSE RATE ENVIRONMENT JUST AHEAD OF UPPER TROUGH OVER PORTIONS OF THE NRN ROCKIES BETWEEN 23/06-12Z. ..CROSBIE/MEAD.. 11/22/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 12:46:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 07:46:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221249 SWODY1 SPC AC 221247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST WED NOV 22 2006 VALID 221300Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...OUTER BANKS OF NC... SURFACE FRONTAL BOUNDARY PRESENTLY DRAPED ACROSS THE AREA WILL REMAIN NEARLY STATIONARY TODAY AS VERTICALLY STACKED LOW MOVES SLOWLY NNEWD. COLDER MID LEVEL TEMPERATURES /-22 DEG C AT 500 MB/ LOCATED OFF THE EAST COAST OF FL EARLY THIS MORNING WILL ROTATE ACROSS THE AREA DURING PEAK HEATING. SUFFICIENT INSTABILITY /MUCAPE FROM 500-750 J/KG/ COUPLED WITH LOW-MID LEVEL MODERATE VERTICAL MOTION EAST OF THE STATIONARY BOUNDARY SHOULD SUPPORT ISOLATED/SCT TSTM DEVELOPMENT...PRIMARILY JUST OFF THE CAROLINA AND MID ATLANTIC COAST. ...PAC NW/NRN ROCKIES... STRONG UPPER LOW/VORT LOBE ROTATING AROUND A BROADER UPPER TROUGH LOCATED OVER THE NERN PACIFIC WILL MOVE TOWARDS THE PAC NW COAST DURING THE AFTERNOON...AND APPROACH THE NRN ROCKIES LATER TONIGHT. ACCOMPANYING POCKET OF COLD MID LEVEL TEMPERATURES WILL SUPPORT STEEP LOW-MID LEVEL LAPSE RATES...MAINLY IN POST-FRONTAL REGIME...WHERE UPSLOPE FLOW AND MARGINAL INSTABILITY WILL REMAIN SUPPORTIVE OF A FEW THUNDERSTORMS NEAR THE WA/ORE COAST. INCREASING MOIST CONVECTION AND POSSIBLY EMBEDDED/ISOLATED TSTMS SHOULD DEVELOP IN STRONG UPSLOPE/STEEP LAPSE RATE REGIME JUST AHEAD OF UPPER TROUGH AND ASSOCIATED COLD FRONT OVER PORTIONS OF THE NRN ROCKIES OVERNIGHT. ..EVANS.. 11/22/2006  From swody1 at goshenarc.org Wed Nov 22 16:20:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 11:20:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221624 SWODY1 SPC AC 221621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1021 AM CST WED NOV 22 2006 VALID 221630Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...ERN NC TO DELMARVA... 16Z STREAMLINE ANALYSIS PLACES A BROAD SFC LOW OVER THE NC CAPES WITH THE PRIMARY MARINE FRONT STILL LOCATED 30-40 MILES OFFSHORE. THE LOW SHOULD CONSOLIDATE ALONG THIS FRONT EAST OF THE CAPES LATER TODAY AS THE NEXT LOBE OF VORTICITY...NOW EVIDENT IN WATER VAPOR IMAGERY OVER ECNTRL FL...ROTATES NNEWD. OLD DEFORMATION ZONE OVER THE FOOTHILLS OF VA...NC...SC SHOULD DIMINISH THIS AFTN...WITH A NEW LOW TO MID-LEVEL FRONTOGENETIC ZONE LIKELY EVOLVING THIS EVE/ OVERNIGHT FROM EXTREME ERN NC NWD TO NEAR THE DELMARVA COAST. MESOSCALE BANDS WITHIN THIS ZONE SHOULD STRENGTHEN AFTER 00Z AS STRONGER H5-H3 QVECTOR CONVERGENCE SHIFTS NWD COINCIDENT WITH MUCAPES UP TO A FEW HUNDRED J PER KG. STRONGER TSTMS SHOULD REMAIN OFFSHORE WHERE THE PRIMARY INSTABILITY AXIS WILL BE LOCATED. ...PAC NW TO THE NRN INTERMOUNTAIN WEST... HEALTHY SHORTWAVE TROUGH WAS LOCATED 200-300 NM OFF THE WA/ORE COAST THIS MORNING PER WATER VAPOR IMAGERY WITH CONSIDERABLE OPEN-CELL CUMULUS FIELD. EXTRAPOLATION SUGGESTS THAT THE CORE OF THE COLD AIR ASSOCD WITH THIS IMPULSE /AOB MINUS 30 DEG C/ WILL SPREAD ACROSS WA/ORE THIS EVE AND INTO THE NRN INTERMOUNTAIN WEST LATE TONIGHT. STEEPENING LAPSE RATES ALOFT COMBINED WITH AN INCREASING WLY COMPONENT TO THE LOW-LEVEL FLOW WILL BE SUFFICIENT FOR PARCELS TO REACH ICING LEVELS AND TSTMS WILL BE POSSIBLE ACROSS THE REGION. HIGHEST PROBABILITIES WILL BE ACROSS NWRN ORE/SWRN WA LATE THIS EVENING. OTHER TSTMS WILL BE POSSIBLE...BUT MORE ISOLD IN COVERAGE...ACROSS THE HIGHER TERRAIN OF ERN WA/ORE EWD INTO WRN MT BY 12Z THU. ..RACY/GRAMS.. 11/22/2006  From swody1 at goshenarc.org Wed Nov 22 19:55:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 14:55:30 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221958 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST WED NOV 22 2006 VALID 222000Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER LEVEL PATTERN SHIFT IS BEGINNING...AS EVIDENT IN NEWD EJECTION OF DEEP/OCCLUDED CYCLONE INVOF COAST...AND IN HEIGHT FALLS ACROSS PACIFIC NW REGION. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY BETWEEN 128W-132W OFFSHORE PACIFIC NW -- IS FCST TO MOVE INLAND DURING 23/00Z-23/03Z TIME FRAME. MEANWHILE...FARTHER SE...SW-NE ELONGATED SFC CYCLONE LOCATED JUST OFFSHORE SRN NC COAST IS FCST TO MOVE SLOWLY NEWD IN TANDEM WITH LOW ALOFT. AIR MASS BETWEEN TIDEWATER REGION AND PACIFIC NW WILL REMAIN TOO DRY AND/OR STABLE TO SUPPORT DEEP MOIST CONVECTION. ...NWRN CONUS... SYNOPTIC SCALE DESTABILIZATION AND COOLING ALOFT WILL INCREASE DURING NEXT FEW HOURS FROM W-E ACROSS WA/ORE...AS STRONGEST DPVA MOVES OVERHEAD PRIOR TO PASSAGE OF MID/UPPER LEVEL TROUGH. THIS SYSTEM IS RESPONSIBLE FOR EXTENSIVE AREA OF DISCRETE/CUMULIFORM CONVECTION OVER WATER...INCLUDING SCATTERED/SMALL CB. MODIFIED RAOBS AND RUC SOUNDINGS SUGGESTS WEAK MUCAPE OF 300 J/KG OR LESS IN MOST AREAS...BUT ALSO WEAK CINH AND STEEP LAPSE RATES...WITH SOME BUOYANCY EXTENDING INTO ICING LAYERS FAVORABLE FOR CG LIGHTNING PRODUCTION. ...TIDEWATER NC TO COASTAL NJ... MRGL/ELEVATED BUOYANCY...ASSOCIATED WITH LOW LEVEL WARM CONVEYOR...WILL SHIFT NWD AND WEAKEN THROUGH REMAINDER PERIOD. HOWEVER...FRONTOGENETIC FORCING NEAR COAST OR JUST OFFSHORE MAY PROVIDE ENHANCED LIFT IN SUPPORT OF POTENTIAL FOR ISOLATED/SPORADIC THUNDER FROM DELMARVA THROUGH COASTAL NJ. FARTHER S...ISOLATED TSTMS IN COLD CORE REGION OF SYSTEM -- LOCATED MAINLY OFFSHORE -- MAY AFFECT IMMEDIATE COASTAL ARAS NC THIS EVENING AND TONIGHT. HOWEVER...SWATH OF MIDLEVEL DRYING THAT HAS WRAPPED AROUND MUCH OF CYCLONE CORE MAY CONTINUE TO LIMIT OVERALL CONVECTIVE COVERAGE. ..EDWARDS.. 11/22/2006  From swody1 at goshenarc.org Thu Nov 23 00:36:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 19:36:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230039 SWODY1 SPC AC 230037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CST WED NOV 22 2006 VALID 230100Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC COASTAL AREAS... IN RESPONSE TO THE PROGRESSION OF AN IMPULSE ROTATING AROUND ITS EASTERN/NORTHERN PERIPHERY...A MID-LEVEL CLOSED LOW HAS REDEVELOPED NORTHEASTWARD INTO AREAS OFF THE CAROLINA COAST...TO THE SOUTH/EAST OF WILMINGTON. ASSOCIATED MID-LEVEL COOLING HAS CONTRIBUTED TO DESTABILIZATION NEAR WAVE ALONG STALLED LOW-LEVEL BAROCLINIC ZONE ...SUPPORTING ONGOING AREA OF SCATTERED THUNDERSTORMS. THIS ACTIVITY MAY PERSIST INTO THE OVERNIGHT HOURS...AND LIKELY WILL BE SLOW TO SHIFT NORTHEAST OF THE NORTH CAROLINA/SOUTHEAST VIRGINIA COAST...AS UPPER SYSTEM REMAINS CUT-OFF FROM THE STRONGER WESTERLIES. ...PACIFIC NORTHWEST... SHORT WAVE TROUGH EMBEDDED WITHIN BELT OF STRONGER POLAR WESTERLIES IS JUST NOW BEGINNING TO SHIFT INTO COASTAL AREAS...AND IS PROGGED EAST OF THE CASCADES BY 23/12Z. MID-LEVEL COLD POOL ASSOCIATED WITH THIS FEATURE WILL OVERSPREAD MUCH OF THE NORTHWESTERN STATES BY DAYBREAK...LIKELY CONTRIBUTING TO SOME DESTABILIZATION AND CONVECTIVE POTENTIAL. HOWEVER...RISK FOR THUNDERSTORMS SEEMS LIKELY TO MOSTLY BE CONFINED TO COASTAL AREAS AND THE WESTERN SLOPES OF THE CASCADES...AS WEAK TO MODERATE MOIST ONSHORE FLOW DEVELOPS LATER THIS EVENING/OVERNIGHT. ..KERR.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 04:48:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 23:48:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230451 SWODY1 SPC AC 230449 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1049 PM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... A SIGNIFICANT PROGRESSIVE SHORT WAVE TROUGH...EMBEDDED WITHIN THE STRONGER NORTHERN BRANCH OF THE POLAR WESTERLIES...IS FORECAST TO LIFT RAPIDLY EAST NORTHEAST OF THE NORTHERN INTERMOUNTAIN REGION... THROUGH THE CENTRAL CANADIAN/U.S. BORDER AREA BY 12Z FRIDAY. THIS IS EXPECTED TO OCCUR AS ANOTHER SHORT WAVE TROUGH MIGRATES INLAND ACROSS SOUTHERN BRITISH COLUMBIA AND WASHINGTON. MEANWHILE...A DOWNSTREAM RIDGE IS PROGGED TO SHIFT EAST OF THE MISSISSIPPI VALLEY...AND MODELS SUGGEST THIS WILL CONTRIBUTE TO THE NORTHEASTWARD ACCELERATION OF MID ATLANTIC COAST CLOSED LOW...OFF NORTH ATLANTIC COASTAL AREAS. IN THE WAKE OF THE EASTERN SYSTEM...LOW/MID-LEVEL RIDGING ...EXTENDING FROM THE UPPER OHIO VALLEY DEEP INTO THE WESTERN GULF OF MEXICO...WILL INHIBIT THE NORTHWARD RETURN OF A SLOWLY MODIFYING/MOISTENING WESTERN GULF BOUNDARY LAYER. AND...A DRY STABLY STRATIFIED ENVIRONMENT WILL PREVAIL ACROSS MOST AREAS EAST OF THE ROCKIES...WITH NEGLIGIBLE POTENTIAL FOR THUNDERSTORM ACTIVITY. SIMILARLY DRY AND STABLE CONDITIONS ACROSS MUCH OF THE WEST WILL ALSO MINIMIZE CONVECTIVE POTENTIAL. AN EXCEPTION MAY EXIST ACROSS PARTS OF THE PACIFIC NORTHWEST. ...PACIFIC NORTHWEST... MODELS SUGGEST THAT ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COASTAL AREAS. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..KERR.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 12:31:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 07:31:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231234 SWODY1 SPC AC 231232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST THU NOV 23 2006 VALID 231300Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC COAST INTO COASTAL NEW ENGLAND... EJECTING LOW PRESSURE SYSTEM WILL CONTINUE TO LIFT NWD ALONG THE EAST COAST TODAY WITH FEED OF WEAK INSTABILITY AND STEEPENING MID LEVEL LAPSE RATES MAINTAINING A FEW THUNDERSTORMS OVER COASTAL WATERS. 12Z SOUNDINGS AT WAL AND OKX BOTH INDICATE SLIVER OF CAPE BETWEEN ROUGHLY H8 AND H5. THOUGH INFLUX OF MOISTURE WILL SUSTAIN MODERATE TO HEAVY MOIST CONVECTION INTO THE MID ATLANTIC AND SRN NEW ENGLAND AHEAD OF THIS SYSTEM...APPEARS THUNDERSTORM POTENTIAL WILL BE QUITE WEAK AWAY FROM THE COAST. ...PACIFIC NORTHWEST... ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COAST....IN WAKE OF SHORTWAVE TROUGH NOW MOVING ACROSS WRN WA. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..EVANS/CROSBIE.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 13:42:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 08:42:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231345 SWODY1 SPC AC 231343 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0743 AM CST THU NOV 23 2006 VALID 231300Z - 241200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED GRAPHIC ...MID ATLANTIC COAST INTO COASTAL NEW ENGLAND... EJECTING LOW PRESSURE SYSTEM WILL CONTINUE TO LIFT NWD ALONG THE EAST COAST TODAY WITH FEED OF WEAK INSTABILITY AND STEEPENING MID LEVEL LAPSE RATES MAINTAINING A FEW THUNDERSTORMS OVER COASTAL WATERS. 12Z SOUNDINGS AT WAL AND OKX BOTH INDICATE SLIVER OF CAPE BETWEEN ROUGHLY H8 AND H5. THOUGH INFLUX OF MOISTURE WILL SUSTAIN MODERATE TO HEAVY MOIST CONVECTION INTO THE MID ATLANTIC AND SRN NEW ENGLAND AHEAD OF THIS SYSTEM...APPEARS THUNDERSTORM POTENTIAL WILL BE QUITE WEAK AWAY FROM THE COAST. ...PACIFIC NORTHWEST... ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COAST....IN WAKE OF SHORTWAVE TROUGH NOW MOVING ACROSS WRN WA. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..EVANS.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 15:41:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 10:41:14 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231544 SWODY1 SPC AC 231542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0942 AM CST THU NOV 23 2006 VALID 231630Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...PAC NW AND NRN ROCKIES TODAY... A PRONOUNCED MID LEVEL SHORTWAVE TROUGH AND ASSOCIATED BAROCLINIC ZONE WILL MOVE EWD OVER THE NRN ROCKIES TODAY...TO THE NRN PLAINS LATE TONIGHT. AN ISOLATED LIGHTNING STRIKE OR TWO COULD ACCOMPANY SHALLOW CONVECTION ALONG THE COLD FRONT ACROSS ERN ID/SW MT/NW WY WHERE RELATIVELY STEEP LAPSE COINCIDE WITH ASCENT ALONG THE FRONT...THOUGH VERY MARGINAL INSTABILITY WILL LIMIT THE OVERALL TSTM THREAT. OTHERWISE...A SECOND TROUGH WILL MOVE EWD OVER WA TODAY INTO TONIGHT. COLD MID LEVEL TEMPERATURES /-34 C AT 500 MB/ AND 7-8 C/KM THROUGH MUCH OF THE LOWEST 6 KM SHOULD REMAIN SUFFICIENT FOR ISOLATED THUNDERSTORMS WITHIN THE BROAD AREA OF CONVECTION NEAR AND DOWNSTREAM FROM THE MID LEVEL WAVE AXIS. ...SE NEW ENGLAND TODAY... A CLOSED LOW JUST OFF THE MID ATLANTIC COAST WILL MOVE NEWD AND LIKELY REMAIN JUST SE OF THE NEW ENGLAND COAST. SOME WEAK ELEVATED CONVECTION MAY OCCUR WITHIN THE BROADER RAIN SHIELD TODAY ACROSS SE NEW ENGLAND...BUT THE MORE SUBSTANTIAL INSTABILITY AND THUNDERSTORM THREAT WILL LIKELY REMAIN OFFSHORE. ..THOMPSON/GRAMS.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 19:55:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 14:55:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231958 SWODY1 SPC AC 231955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST THU NOV 23 2006 VALID 232000Z - 241200Z ...NO SVR TSTM AREAS FORECAST... LATEST WATER VAPOR IMAGERY SHOWS TWO UPPER-LEVEL TROUGHS IN PLACE ACROSS THE CONUS. THE FIRST TROUGH IS ASSOCIATED WITH A CLOSED LOW LOCATED JUST OFF THE COAST OF MARYLAND. STRONG ASCENT AND COLD AIR ALOFT WITH THE UPPER-LOW MAY BE ENOUGH TO SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT MAINLY IN THE COASTAL WATERS OFF OF SRN NEW ENGLAND. THE SECOND UPPER TROUGH EXTENDS WWD FROM THE NRN HIGH PLAINS INTO THE PACIFIC NORTHWEST. A FEW THUNDERSTORMS MAY FORM ALONG THE COASTAL SECTIONS OF WA THIS EVENING AS A SECONDARY UPPER-LEVEL IMPULSE MOVES INLAND. NO SEVERE THREAT IS ANTICIPATED ACROSS THE CONUS THROUGH THE DAY 1 PERIOD. ..BROYLES.. 11/23/2006  From swody1 at goshenarc.org Fri Nov 24 00:47:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 19:47:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240050 SWODY1 SPC AC 240047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 PM CST THU NOV 23 2006 VALID 240100Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...NORTH CENTRAL STATES... ISOLATED...SHORT-LIVED WEAK THUNDERSTORM ACTIVITY HAS BEEN EVIDENT ACROSS THE NORTH CENTRAL ROCKIES INTO THE NORTHERN HIGH PLAINS... IN ASSOCIATION WITH INITIAL SHORT WAVE TROUGH EMANATING FROM THE NORTHEAST PACIFIC. OROGRAPHY AND HEATING IN THE LEE OF THE HIGHER TERRAIN HAVE CONTRIBUTED TO DESTABILIZATION BENEATH LEADING EDGE OF COLD MID-LEVEL AIR MASS ACCOMPANYING UPPER SYSTEM. AS THIS FEATURE CONTINUES TO PIVOT DEEPER INTO THE PLAINS AND UPPER MISSISSIPPI VALLEY TONIGHT...SPORADIC THUNDERSTORM ACTIVITY SHOULD DIMINISH. ...PACIFIC NORTHWEST COAST... THE EXIT REGION OF A BROADLY CYCLONIC MID/UPPER JET STREAK CONTINUES TO NOSE INTO THE NORTHERN CASCADES. THIS...IN CONJUNCTION WITH 30 TO 40 KT 850 MB ONSHORE FLOW...IS CONTRIBUTING TO DESTABILIZATION AND WEAK CONVECTIVE DEVELOPMENT...INCLUDING A SCATTERING OF THUNDERSTORMS ACROSS AREAS WEST OF THE WASHINGTON/NORTHERN OREGON CASCADES. AS THE UPPER SYSTEM PROGRESSES INLAND THIS EVENING...POTENTIAL FOR THUNDERSTORMS WILL DIMINISH...AS LOW-LEVEL ONSHORE/UPSLOPE FLOW WEAKENS...AND MID-LEVELS GRADUALLY WARM. THIS MAY BE SLOWEST TO OCCUR ACROSS AREAS NEAR/WEST OF PUGET SOUND...BUT THREAT IS EXPECTED TO END IN AREAS TO THE SOUTH BY 06Z. ...NORTH ATLANTIC COAST... THE CLOSED LOW ACCELERATING NORTHEAST OF THE MID ATLANTIC COAST IS PROGGED TO TURN MORE TO THE EAST AS IT APPROACHES THE SOUTHERN NEW ENGLAND COAST...DUE TO THE INFLUENCE OF A PROGRESSIVE SHORT WAVE IMPULSE IN THE NORTHERN STREAM. AND...IT APPEARS MOST LIKELY THAT ANY THUNDERSTORM ACTIVITY NEAR WEAKENING MID-LEVEL CIRCULATION SHOULD PASS TO THE SOUTHEAST OF CAPE COD. ..KERR.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 04:40:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 23:40:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240443 SWODY1 SPC AC 240440 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1040 PM CST THU NOV 23 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... MODELS SUGGEST THAT THE POLAR WESTERLIES WILL REMAIN SPLIT INTO A COUPLE OF DISTINCT STRONGER BELTS THROUGH THIS FORECAST PERIOD. BUT...BROAD UPPER TROUGHING IS PROGGED TO CONTINUE TO EVOLVE FROM THE EASTERN PACIFIC THROUGH THE PLAINS AND UPPER MISSISSIPPI VALLEY...WHILE A DOWNSTREAM RIDGE SHIFTS EAST OF THE MISSISSIPPI VALLEY INTO THE EASTERN STATES. A STRONG JET STREAK IN THE BASE OF THE UPPER TROUGH...ASSOCIATED WITH THE PHASING OF THE SOUTHERN BRANCH OF THE POLAR WESTERLIES AND THE SUBTROPICAL STREAM...IS PROGGED TO NOSE EAST OF THE SOUTHERN U.S./NORTHERN MEXICAN PLATEAU REGION INTO THE SOUTHERN PLAINS. THIS WILL PROBABLY CONTRIBUTE TO AN AREA OF BROAD/WEAK LARGE-SCALE ASCENT FROM PARTS OF THE SOUTH CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY DURING THE LATTER PART OF THE PERIOD. HOWEVER...IN THE WAKE OF THE CLOSED LOW NOW ACCELERATING AWAY FROM ATLANTIC COASTAL AREAS...THE BOUNDARY LAYER OVER THE GULF OF MEXICO IS ONLY SLOWLY BEGINNING TO MODIFY/MOISTEN. WHILE A SOUTHERLY LOW-LEVEL FLOW WILL BEGIN TO DEVELOP ACROSS THE SOUTH CENTRAL STATES AS A LOW-LEVEL RIDGE RETREATS TOWARD THE ATLANTIC SEABOARD...POTENTIAL FOR THUNDERSTORMS APPEARS NEGLIGIBLE ACROSS THE CENTRAL STATES...AND THE REMAINDER OF THE U.S...THROUGH AT LEAST 12Z SATURDAY. ..KERR.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 12:49:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 07:49:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241252 SWODY1 SPC AC 241250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST FRI NOV 24 2006 VALID 241300Z - 251200Z ...NO TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO EVOLVE ACROSS THE WESTERN UNITED STATES AND EASTERN PACIFIC TODAY. GENERALLY DRY/STABLE CONDITIONS ARE EXPECTED TO PRECLUDE THUNDERSTORMS OVER THE CONTIGUOUS U.S. DURING THIS FORECAST PERIOD. ISOLATED LIGHTNING STRIKES MAY OCCUR OFF THE WA AND FL COASTS...BUT THREATS IN THESE AREAS SHOULD ALSO REMAIN RATHER LOW. ..HART.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 16:16:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 11:16:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241618 SWODY1 SPC AC 241616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1016 AM CST FRI NOV 24 2006 VALID 241630Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/DISCUSSION... NO THREAT FOR SEVERE WEATHER TODAY WITH LITTLE OR NO AVAILABLE INSTABILITY FOR THUNDERSTORMS. A RIDGE ACROSS THE ERN CONUS AND SURFACE HIGH PRESSURE WILL KEEP CONDITIONS THERE VERY DRY. MEAGER MOISTURE RETURN WILL OCCUR INTO TX AROUND WRN EDGE OF THIS HIGH...AHEAD OF WEAK SRN STREAM TROUGH ACROSS THE WEST. RELATIVELY COOL TEMPERATURES ALOFT EXIST WITH THIS TROUGH ACROSS MUCH OF THE WEST...HOWEVER...PRECIPITABLE WATER VALUES WILL REMAIN LOW AND GENERALLY UNDER 0.33 IN. FARTHER N...A STRONGER NRN STREAM JET AND TEMPERATURE GRADIENT ALOFT WILL ALLOW FOR STEEP LAPSE RATES...BUT INSTABILITY WILL REMAIN LOW HERE AS WELL WITH ONLY A VERY LOW PROBABILITY OF A LIGHTNING STRIKE COASTAL WA. ..JEWELL/HALES.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 19:46:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 14:46:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241949 SWODY1 SPC AC 241947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST FRI NOV 24 2006 VALID 242000Z - 251200Z ...NO SVR TSTM AREAS FORECAST... A BROAD UPPER-LEVEL TROUGH OVER THE WRN U.S. WILL REMAIN IN PLACE TODAY AND TONIGHT. A SHORTWAVE TROUGH IS FORECAST TO MOVE EWD INTO THE PACIFIC NORTHWEST THIS EVENING. STRONG LARGE-SCALE ASCENT AND COLD TEMPS ALOFT ASSOCIATED WITH THE SHORTWAVE TROUGH MAY RESULT IN THE DEVELOPMENT OF ISOLATED THUNDERSTORMS OFF THE COAST OF WASHINGTON TONIGHT. OTHERWISE...NO CONVECTION IS EXPECTED ACROSS THE CONUS. ..BROYLES.. 11/24/2006  From swody1 at goshenarc.org Sat Nov 25 00:24:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 19:24:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250027 SWODY1 SPC AC 250024 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0624 PM CST FRI NOV 24 2006 VALID 250100Z - 251200Z ...NO TSTM AREAS FORECAST... A LARGE-SCALE UPPER TROUGH CONTINUES TO EVOLVE ACROSS THE EASTERN PACIFIC INTO THE PLAINS/UPPER MISSISSIPPI VALLEY...BUT THE FLOW REGIME BETWEEN SPLIT BELTS OF POLAR WESTERLIES TO THE EAST OF THE TROUGH AXIS REMAINS CONFLUENT. AND...SOUTHERN STREAM IMPULSE LIKELY WILL WEAKEN AS IT BEGINS TO LIFT NORTHEAST OF THE FOUR CORNERS STATES LATER TONIGHT. AN ELONGATED SURFACE RIDGE EXTENDING FROM THE EASTERN CANADIAN PROVINCES INTO GULF OF MEXICO HAS INHIBITED THE MODIFICATION OF THE BOUNDARY LAYER OVER THE GULF OF MEXICO...WHERE SURFACE DEW POINTS HAVE REMAINED MORE OR LESS STEADY IN THE 50S DURING THE PAST 24 HOURS. WITH LITTLE CHANGE ANTICIPATED IN THE SHORT TERM... SUBSTANTIAL RETURN FLOW OF MOISTURE INTO THE CENTRAL STATES APPEARS UNLIKELY THROUGH THE REMAINDER OF THIS PERIOD AND BEYOND. ACROSS THE PACIFIC NORTHWEST...COLDER MID-LEVEL ENVIRONMENT ASSOCIATED WITH THE NORTHERN STREAM APPEARS LIKELY TO REMAIN MOSTLY INLAND OR NORTH OF THE CANADIAN/U.S. BORDER. AND...WITH ONSHORE LOW-LEVEL/UPSLOPE FLOW REMAINING WEAK INTO SATURDAY...POTENTIAL FOR THUNDERSTORMS APPEARS NEGLIGIBLE. ..KERR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 04:33:49 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 23:33:49 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250436 SWODY1 SPC AC 250434 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1034 PM CST FRI NOV 24 2006 VALID 251200Z - 261200Z ...NO TSTM AREAS FORECAST... A CYCLONIC UPPER FLOW CONTINUES TO EVOLVE FROM THE EASTERN PACIFIC THROUGH THE PLAINS AND UPPER MISSISSIPPI VALLEY REGION. MODELS INDICATE THAT THIS REGIME WILL REMAIN COMPRISED OF A COUPLE OF DISTINCT STRONGER BELTS...BUT THE PATTERN IS FORECAST TO BEGIN AMPLIFYING TOWARD THE END OF THE FORECAST PERIOD. THE MOST SIGNIFICANT EMBEDDED SHORT WAVE IMPULSES APPEAR LIKELY TO BE DIGGING IN THE SOUTHERN BRANCH OF THE POLAR WESTERLIES...ONE OFF THE PACIFIC NORTHWEST COAST...THE OTHER INTO THE BASE OF AN IN PHASE SOUTHERN BRANCH/SUBTROPICAL STREAM TROUGH ACROSS BAJA. FARTHER EAST...A MID-LEVEL SHORT WAVE TROUGH...EMBEDDED WITHIN THE NORTHERN STREAM...IS PROGGED TO SHIFT EAST OF THE NORTHERN INTERMOUNTAIN REGION INTO THE NORTHERN PLAINS BY 12Z SUNDAY. MEANWHILE...A COUPLE OF ADDITIONAL SOUTHERN BRANCH IMPULSES ARE FORECAST TO ACCELERATE NORTHEASTWARD AND WEAKEN WITHIN CONFLUENT REGIME EAST OF BROADER SCALE TROUGH AXIS...INTO UPPER RIDGE OVER THE EASTERN STATES. THE INCREASINGLY SHEARED LEAD IMPULSE IS PROGGED TO LIFT ACROSS THE CENTRAL PLAINS AND MID MISSOURI VALLEY INTO THE UPPER GREAT LAKES REGION...WHILE THE UPSTREAM SYSTEM LIFTS ACROSS THE LOWER COLORADO VALLEY INTO THE FOUR CORNERS REGION. ...EAST OF THE ROCKIES... MOISTENING OF THE BOUNDARY LAYER OVER THE WESTERN GULF OF MEXICO HAS BEEN INHIBITED BY AN ELONGATED SURFACE RIDGE EXTENDING FROM THE ST. LAWRENCE VALLEY INTO THE GULF OF MEXICO. WHILE A MORE RAPID MODIFICATION MAY BEGIN TO OCCUR DURING THIS PERIOD...A SIGNIFICANT RETURN FLOW OF MOISTURE INTO THE CENTRAL STATES APPEARS UNLIKELY TO OCCUR. ISENTROPIC ASCENT OF AN AIR MASS CHARACTERIZED BY 40S/LOWER 50S SURFACE DEW POINTS COULD EVENTUALLY SATURATE LOWER LEVELS TO THE WEST OF SURFACE RIDGE...ACROSS PARTS OF THE MID MISSOURI VALLEY INTO THE LOWER GREAT LAKES...TOWARD THE END OF THE PERIOD. HOWEVER...MODEL FORECAST SOUNDINGS SUGGEST THAT AN INITIALLY WARM AND DRY LOWER/MID TROPOSPHERE WILL PROBABLY INHIBIT DEEP CONVECTIVE DEVELOPMENT THROUGH AT LEAST 12Z SUNDAY. ...WEST OF ROCKIES... SOME MOISTENING IS OCCURRING ACROSS THE FOUR CORNERS WITH INITIAL SOUTHERN BRANCH SHORT WAVE TROUGH. AND...UPSTREAM SYSTEM MAY REMAIN VIGOROUS ENOUGH TO SUPPORT SIGNIFICANT UPWARD VERTICAL MOTION. HOWEVER...THIS DOES NOT LOOK LIKELY TO SPREAD INTO THE MORE FAVORABLE OROGRAPHY OF THE FOUR CORNERS REGION UNTIL AFTER SUNSET...WHICH WILL PROBABLY MINIMIZE POTENTIAL FOR THUNDERSTORM ACTIVITY. FARTHER NORTH...HEATING ACROSS THE NORTHERN ROCKIES WILL CONTRIBUTE TO AT LEAST MARGINAL DESTABILIZATION BENEATH VERY COLD MID-LEVEL AIR MASS ASSOCIATED WITH THE NORTHERN BRANCH SHORT WAVE TROUGH. HOWEVER...SOUNDINGS ACROSS THESE AREAS ARE FORECAST TO REMAIN LARGELY BELOW FREEZING. WHILE SCATTERED LOW-TOPPED CONVECTION IS PROBABLE...THUNDERSTORM ACTIVITY...IF ANY...SEEMS LIKELY TO BE VERY ISOLATED OR SPARSE IN COVERAGE. ..KERR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 12:33:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 07:33:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251235 SWODY1 SPC AC 251233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 AM CST SAT NOV 25 2006 VALID 251300Z - 261200Z ...NO TSTM AREAS FORECAST... MORNING WATER VAPOR LOOP SHOWS SEVERAL SHORTWAVE TROUGHS MOVING ACROSS THE WESTERN STATES. DESPITE LOCAL FORCING FOR VERTICAL MOTION IMMEDIATELY AHEAD OF THESE FEATURES...RELATIVELY DRY/STABLE CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE UNITED STATES AGAIN TODAY. THIS IS EXPECTED TO PRECLUDE ORGANIZED THUNDERSTORMS. THERE IS...HOWEVER...ONE AREA TO BE MONITORED. ...WESTERN CO THIS EVENING... UPPER VORT MAX CURRENTLY APPROACHING THE LA BASIN IS FORECAST TO MOVE EASTWARD AND INTO THE FOUR CORNERS REGION BY THIS EVENING. MODEL GUIDANCE SUGGESTS THAT AIR MASS AHEAD OF SYSTEM IS CHARACTERIZED BY RELATIVELY STEEP LAPSE RATES...BUT VERY LITTLE LOW/MID LEVEL MOISTURE. LIFT AHEAD OF TROUGH...COUPLED WITH OROGRAPHIC EFFECTS...MAY BE SUFFICIENT FOR SCATTERED SHOWERS AND ISOLATED LIGHTNING STRIKES AFTER DARK ACROSS WESTERN CO. HOWEVER...DEEP CONVECTIVE THREAT APPEARS TOO MARGINAL TO OUTLOOK AT THIS TIME. ..HART/TAYLOR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 16:29:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 11:29:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251632 SWODY1 SPC AC 251629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST SAT NOV 25 2006 VALID 251630Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/DISCUSSION... MDT SWLY FLOW WITHIN BROAD SRN STREAM JET WILL REMAIN SITUATED FROM NRN MX ACROSS THE CNTRL PLAINS AND INTO THE GREAT LAKES WITH NRN STREAM JET ALONG THE U.S./CANADIAN BORDER. VERY COOL AIR ALOFT WILL EXIST OVER MUCH OF THE NRN AND WRN CONUS WHICH WILL RESULT IN CONDITIONAL THREAT OF ISOLATED THUNDERSTORMS MAINLY ACROSS SRN IA AND NRN MO WITH ELEVATED MOISTURE RETURN. ...NRN MO/SRN IA/ERN NEB/KS... MOIST PLUME IS IN PLACE WITH PRECIPITABLE WATER VALUES OF 0.50-0.75. CONTINUED ELEVATED WARM ADVECTION ALONG WITH RELATIVELY STEEP MID LVL LAPSE RATES MAY ALLOW FOR A FEW LIGHTNING STRIKES AS WEAK UPPER LVL SHORTWAVE TROUGH NOW EMERGING INTO WRN KS CONTINUES NEWD...AND LOW LEVEL WARM ADVECTION AROUND 850 MB PERSISTS. ..JEWELL/HALES.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 19:44:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 14:44:33 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251947 SWODY1 SPC AC 251944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0144 PM CST SAT NOV 25 2006 VALID 252000Z - 261200Z ...NO SVR TSTM AREAS FORECAST... SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE CNTRL AND ERN UNITED STATES. A COLD FRONT WILL MOVE SLOWLY SWD ACROSS THE CNTRL PLAINS AND UPPER MIDWEST TONIGHT. A FEW THUNDERSTORMS MAY DEVELOP LATE IN THE PERIOD ALONG THE BOUNDARY AS THE LOW-LEVEL JET BECOMES ENHANCED LATE TONIGHT. NO SEVERE THUNDERSTORMS SHOULD OCCUR WITH THE ACTIVITY. ..BROYLES.. 11/25/2006  From swody1 at goshenarc.org Sun Nov 26 00:09:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 19:09:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260012 SWODY1 SPC AC 260010 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0610 PM CST SAT NOV 25 2006 VALID 260100Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SERN NEB/NERN KS/NRN MO/CENTRAL-SRN IA... A COUPLE OF SHORT WAVE TROUGHS WILL TRAVERSE NEWD ACROSS THE CENTRAL/SRN PLAINS TO THE GREAT LAKES REGION WITHIN SUBTROPICAL STREAM ALONG THE ERN PERIPHERY OF WRN U.S. LONG WAVE TROUGH. A SURFACE BOUNDARY EXTENDING FROM NRN KS TO ALONG THE MO/IA BORDER INTO SRN WI SHOULD CONTINUE TO MOVE SLOWLY NWD TONIGHT...AS A COLD FRONT SPREADS SEWD INTO THE UPPER MS VALLEY AND NEB. WATER VAPOR IMAGERY INDICATED A LEAD SHORT WAVE TROUGH TRACKING ACROSS NERN KS/SRN IA AT THIS TIME...WITH THIS FEATURE EXPECTED TO DEPART THE DAY 1 GENERAL TSTM OUTLOOK AREA THIS EVENING. ASCENT WITH THIS FEATURE HAS AIDED IN MOISTENING THE MID LEVELS AS SHOWN BY CLOUDS ACROSS THIS AREA. THIS MOISTENING COMBINED WITH ASCENT AHEAD OF NEXT UPSTREAM SPEED MAX/SHORT WAVE TROUGH...NOW LOCATED OVER SRN ROCKIES/HIGH PLAINS...AND WAA ALONG NOSE OF STRENGTHENING SWLY LLJ MAY SUPPORT CONVECTION AND A FEW LIGHTNING STRIKES THIS FORECAST PERIOD. THIS ACTIVITY...THOUGH LIKELY SPARSE...SHOULD PRIMARILY BE LOCATED ALONG/N OF RETREATING SURFACE BOUNDARY FROM NERN KS INTO IA. ..PETERS.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 05:29:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 00:29:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260531 SWODY1 SPC AC 260530 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 PM CST SAT NOV 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE UPPER TROUGH LOCATED WEST OF THE ROCKIES IS EXPECTED TO AMPLIFY THIS FORECAST PERIOD AS VORTEX OVER BRITISH COLUMBIA MOVES SWD TOWARD PACIFIC NW AND DEEPENS. AS THIS PROCESS OCCURS...PACIFIC SHORT WAVE TROUGH...CURRENTLY LOCATED NEAR 49N 139W PER WATER VAPOR IMAGERY...WILL DIG SSEWD REACHING SRN CA/GREAT BASIN BY 12Z MONDAY. DOWNSTREAM SHORT WAVE TROUGH TRACKING NEWD FROM FOUR CORNERS REGION TO THE CENTRAL PLAINS AND MID MO VALLEY WILL LIKELY DE-AMPLIFY AS IT APPROACHES REGION OF HEIGHT RISES/RIDGING ACROSS THE CENTRAL STATES. ...PACIFIC NW COAST SWD ALONG THE NRN CA COAST... STRONG HEIGHT FALLS ARE EXPECTED ACROSS THIS REGION AS UPPER VORTEX DEEPENS DURING THE FORECAST PERIOD. INITIAL THREAT FOR TSTMS SHOULD BE AS ASCENT ASSOCIATED WITH PACIFIC SHORT WAVE TROUGH/SURFACE FRONT SPREADS INLAND ALONG THE ORE TO NRN CA COAST THIS MORNING AND AFTERNOON. ADDITIONAL TSTMS WILL BE LIKELY OFFSHORE TO ALONG THE PAC NW COAST BY THIS EVENING WITHIN MOIST...POST-FRONTAL ONSHORE FLOW REGIME LOCATED BENEATH VERY COLD MID LEVEL TEMPERATURES /-30 TO -34 C AT 500 MB/. ...IA/FAR SRN MN/SWRN WI SWWD TO ERN NEB/NERN KS... IN THE LOW LEVELS...SURFACE BOUNDARY EXPECTED TO EXTEND FROM NRN KS ENEWD INTO SRN IA AND SRN WI SHOULD REMAIN NEARLY STATIONARY TODAY...AS A COLD FRONT...INITIALLY EXTENDING FROM NRN NEB TO NRN WI...MOVES SWD MERGING WITH THE SRN BOUNDARY. LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NNEWD WITH SURFACE DEWPOINTS IN THE LOWER 50S REACHING SERN NEB TO SRN IA/SRN WI BY LATE THIS AFTERNOON. ALTHOUGH THE FOUR CORNERS TROUGH WILL BE DE-AMPLIFYING AS IT APPROACHES THE CENTRAL PLAINS TO MID MO VALLEY TONIGHT...PLUME OF STEEP MID LEVEL LAPSE RATES /7+ C/KM/ WILL BE ADVECTED DOWNSTREAM AHEAD OF THIS TROUGH AND ATOP NRN EXTENT OF MOISTURE RETURN. THIS WILL AID IN WEAK DESTABILIZATION. DESPITE WEAK UPPER FORCING THIS EVENING AND OVERNIGHT WITH THE DAMPENING TROUGH...INCREASING LOW LEVEL WAA SHOULD SUPPORT AN AREA OF TSTMS FROM ERN NEB/NERN KS ACROSS IA/FAR SRN MN AND POTENTIALLY SWRN WI. SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...THOUGH THE MARGINAL INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ..PETERS/TAYLOR.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 12:43:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 07:43:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261245 SWODY1 SPC AC 261242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 AM CST SUN NOV 26 2006 VALID 261300Z - 271200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL REMAIN OVER THE WESTERN AND CENTRAL STATES TODAY...WITH RIDGING MAINTAINING CONTROL OVER THE SOUTHEAST REGION. TWO AREAS APPEAR TO HAVE A THREAT OF ISOLATED-SCATTERED THUNDERSTORMS TODAY: THE MIDWEST STATES AND THE PACIFIC NORTHWEST COAST. ...CENTRAL PLAINS INTO MIDWEST... MID LEVEL VORT MAX CURRENTLY OVER WESTERN CO HAS RESULTED IN ISOLATED LIGHTNING STRIKES OVERNIGHT SOUTH OF GJT. THIS FEATURE WILL MOVE ACROSS THE CENTRAL PLAINS TODAY AND APPROACH THE WESTERN EDGE OF MORE MOIST/UNSTABLE AIRMASS LATER THIS AFTERNOON AND EVENING. LOW LEVEL WARM ADVECTION AND LIFT WILL HELP TO INITIATE SCATTERED THUNDERSTORMS OVER EASTERN NEB/NORTHEAST KS AFTER 00Z...SPREADING NORTHEASTWARD ACROSS IA DURING THE NIGHT. PRESENT INDICATIONS ARE THAT WEAK INSTABILITY WILL PRECLUDE A RISK OF ORGANIZED SEVERE STORMS. ...PACIFIC NORTHWEST COAST... VIGOROUS UPPER TROUGH IS MOVING ASHORE THIS MORNING ALONG THE WA/ORE COASTS. ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE ALONG COASTAL RANGES EARLY TODAY AS SYSTEM PASSES. OTHER CONVECTION MAY DEVELOP THIS AFTERNOON IN WAKE OF SHORTWAVE TROUGH DUE TO COLD TEMPERATURES ALOFT AND OROGRAPHIC LIFT. ..HART/TAYLOR.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 16:11:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 11:11:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261614 SWODY1 SPC AC 261611 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1011 AM CST SUN NOV 26 2006 VALID 261630Z - 271200Z ...NO SVR TSTM AREAS FORECAST... UPPER TROUGH OVER WRN U.S. WILL DEEPEN THIS FORECAST PERIOD IN RESPONSE TO A VIGOROUS SYSTEM NOW MOVING INTO PAC NW. BROAD SWLY FLOW PREVAILS FROM THE SWRN U.S. TO THE GREAT LAKES. A WEAKENING MID LEVEL IMPULSE EMBEDDED IN THIS FLOW CURRENTLY VICINITY CO WILL MOVE QUICKLY ACROSS PLAINS AND UPPER MS VALLEY BY MON AM. RETURN OF MODIFIED GULF MOISTURE WILL CONTINUE INTO MON SRN/CENTRAL PLAINS ACROSS MID MS VALLEY UNDER SWLY FLOW AT ALL LEVELS. INSUFFICIENT INSTABILITY AND ONLY WEAK UPPER SUPPORT WILL BE ASSOCIATED WITH THE IMPULSE MOVING ACROSS THE PLAINS TODAY TO SUPPORT ANY THREAT OF SEVERE THUNDERSTORMS. HOWEVER CONVECTION IS EXPECTED TO INCREASE MAINLY OVERNIGHT AS UPPER LEVEL IMPULSE INTERACTS WITH PLUME OF MODIFIED GULF MOISTURE FROM ERN NE/KS TO WI. THUNDERSTORMS THIS AREA WILL BE ELEVATED...BUT WITH MUCAPES POSSIBLY TO 500 J/KG...MID LEVEL LAPSE RATES AROUND 7C/KM AND LOW WET BULB ZERO LEVELS...THERE COULD BE SMALL HAIL ASSOCIATED WITH MORE VIGOROUS UPDRAFTS. IN THE WAKE OF SURFACE LOW MOVING INLAND WRN WA TODAY A COLD AND WEAKLY UNSTABLE ONSHORE FLOW WILL DEVELOP. THIS SHOULD SUPPORT A FEW LOW TOPPED THUNDERSTORMS COASTAL AREA PAC NW...MOST LIKELY AFTER 00Z. ..HALES/JEWELL.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 19:49:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 14:49:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261951 SWODY1 SPC AC 261949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN NOV 26 2006 VALID 262000Z - 271200Z ...NO SVR TSTM AREAS FORECAST... BROAD SOUTHWESTERLY FLOW WILL REMAIN IN PLACE TONIGHT ACROSS MOST OF THE UNITED STATES AS AN UPPER-TROUGH COMES ASHORE IN THE PACIFIC NORTHWEST. THUNDERSTORM ACTIVITY MAY OCCUR ALONG THE WEST COAST ASSOCIATED WITH COLD AIR ALOFT IN THE UPPER-TROUGH AS THE STRONGER BANDS OF LARGE-SCALE ASCENT MOVE INLAND LATE TONIGHT. OTHERWISE...A FEW THUNDERSTORMS MAY ALSO OCCUR IN THE CNTRL PLAINS AND UPPER MIDWEST ALONG THE NOSE OF THE LOW-LEVEL JET AS LOW-LEVEL MOISTURE ADVECTION INCREASES TONIGHT. NONE OF THE THUNDERSTORM ACTIVITY IS EXPECTED TO APPROACH SEVERE LIMITS. ..BROYLES.. 11/26/2006  From swody1 at goshenarc.org Mon Nov 27 00:48:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 19:48:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270051 SWODY1 SPC AC 270049 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0649 PM CST SUN NOV 26 2006 VALID 270100Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL PLAINS NEWD TO PARTS OF WRN GREAT LAKES... EARLY EVENING SATELLITE IMAGERY INDICATED A LOW AMPLITUDE SHORT WAVE TROUGH OVER NEB/NRN KS. THIS FEATURE WILL PROGRESS NEWD WITHIN SWLY FLOW ALOFT...REACHING SERN MN/WI BY 12Z MONDAY...AS THE NEXT UPSTREAM IMPULSE TRACKS NEWD INTO THE SRN HIGH PLAINS. IN THE LOW LEVELS...AN ARCTIC COLD FRONT WILL CONTINUE TO SPREAD SWD THROUGH THE CENTRAL PLAINS OVERNIGHT AND SHOULD EXTEND FROM THE NRN TX PANHANDLE/NW OK REGION NEWD INTO NWRN MO AND CENTRAL IA TO SERN MN BY END OF DAY 1 PERIOD. MEANWHILE...A SECOND BOUNDARY MARKING NWD EXTENT OF LOW LEVEL MOISTURE RETURN /SURFACE DEWPOINTS IN THE LOWER 50S/ SHOULD REMAIN STATIONARY FROM NERN IA THROUGH SRN WI TO CENTRAL LOWER MI. STRENGTHENING SWLY LLJ EXTENDING FROM SRN PLAINS TO SRN/ERN IA WILL MAINTAIN MOISTURE RETURN...WHILE ASCENT WITHIN WAA IN VICINITY OF LLJ AND DEEP LAYER ASCENT AHEAD OF CENTRAL PLAINS TROUGH EXPECTED TO SUPPORT INCREASE IN CONVECTION. ACTIVITY SHOULD SPREAD NEWD ALONG/N OF STATIONARY BOUNDARY...POTENTIALLY REACHING LM AND WRN LOWER MI AS UPPER TROUGH APPROACHES WI BY 27/12Z. PLUME OF STEEP LAPSE RATES /7.5 TO 8 C/KM PER 27/00Z SOUNDINGS FROM NEB TO WI/ ATOP LOW LEVEL WARM AIR AND MOISTURE ADVECTION COMBINED WITH EFFECTIVE BULK SHEAR OF 25-30 KT SUGGEST POTENTIAL FOR MARGINALLY SEVERE HAIL WITH STRONGER STORMS. HOWEVER...SEVERE THREAT SHOULD REMAIN TOO LOW... GIVEN WEAK INSTABILITY...AND THUS PRECLUDE INTRODUCTION OF SEVERE PROBABILITIES. SECOND AREA OF INCREASING ISENTROPIC ASCENT...IN ADVANCE OF IMPULSE APPROACHING SRN HIGH PLAINS...OVER PARTS OF CENTRAL KS AND POTENTIALLY FAR NW OK TO THE NORTH OF SURGING COLD FRONT SUGGESTS THREAT FOR TSTMS LATE IN FORECAST PERIOD. ...PACIFIC NW COAST SWD ALONG NRN/CENTRAL CA COAST... A FEW LIGHTNING STRIKES REMAIN POSSIBLE...MAINLY ALONG AND OFFSHORE OF THE CENTRAL CA COAST...AS ASCENT WITH A SHORT WAVE TROUGH SPREADS SEWD ACROSS CENTRAL TO SRN CA. ADDITIONAL TSTMS ARE POSSIBLE FARTHER N ALONG THE PACIFIC NW COAST AS COLD MID LEVEL TEMPERATURES /LESS THAN -30 C AT 500 MB/ WITH DEEPENING VORTEX SPREAD INLAND ATOP MOIST...POST-FRONTAL ONSHORE FLOW. ..PETERS.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 05:42:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 00:42:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270545 SWODY1 SPC AC 270542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1142 PM CST SUN NOV 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER LEVEL TROUGH...CURRENTLY DEEPENING ACROSS THE PACIFIC NW AND INTERMOUNTAIN WEST...IS EXPECTED TO BEGIN TO MOVE EWD THIS FORECAST PERIOD. THIS WILL OCCUR AS STRONG MID/UPPER LEVEL WINDS TRANSLATE INTO THE BASE OF THIS TROUGH FROM THE GREAT BASIN EWD TO THE CENTRAL PLAINS. A COUPLE OF SHORT WAVE TROUGHS WITHIN SWLY FLOW ALOFT WILL TRACK NEWD ACROSS THE CENTRAL STATES THROUGH TONIGHT. COLD FRONT IS EXPECTED TO EXTEND FROM THE TX PANHANDLE/NW OK NEWD THROUGH ERN KS TO ERN IA...AND THEN EWD ACROSS SRN WI TO LOWER MI AT 12Z TODAY. THIS BOUNDARY SHOULD REMAIN MAINLY STATIONARY INTO THE AFTERNOON...WITH A SURFACE WAVE DEVELOPING OVER WRN OK BY LATE AFTERNOON AS LEAD SHORT WAVE TROUGH TRACKS ACROSS OK/KS. THIS IMPULSE WILL CONTINUE TO MOVE NEWD ACROSS THE MID/LOWER MO VALLEYS TO THE WRN GREAT LAKES REGION TONIGHT. THE ATTENDANT SURFACE LOW SHOULD MOVE MORE NWD INTO WRN/NRN IA AS STRONGER HEIGHT FALLS/ SURFACE PRESSURE FALLS DEVELOP ACROSS THE NRN PLAINS AND UPPER MIDWEST IN RESPONSE TO EWD PROGRESSION OF WRN LONG WAVE TROUGH. KS/MO PORTION OF SURFACE FRONT WILL LIKEWISE RETREAT NWD AFTER 28/00Z TO ALONG THE IA/MN BORDER BY 12Z TUESDAY. MEANWHILE... PRIMARY CYCLONE IS EXPECTED TO DEEPEN OVER WY TODAY...BEFORE MOVING EWD INTO SD BY TUESDAY MORNING. ...SRN PLAINS NEWD TO MID MO VALLEY... LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NEWD ALONG/E OF SURFACE FRONT AS SSWLY LLJ EXTENDING FROM SRN PLAINS TO LOWER MO/MID MS VALLEYS STRENGTHENS THROUGH THE FORECAST PERIOD...WITH EXTENSIVE CLOUDINESS LIKELY LIMITING AIR MASS DESTABILIZATION. ELEVATED TSTMS MAY BE ONGOING AT 12Z TODAY OVER PARTS OF CENTRAL KS/NW OK WITHIN REGION OF ISENTROPIC ASCENT NORTH OF COLD FRONT. DEEP LAYER ASCENT AND SUBSEQUENT POTENTIAL FOR TSTMS WILL CONTINUE TO INCREASE INITIALLY ACROSS KS/NW OK...AND THEN SWD THROUGH OK AND W/NW TX ALONG LEE TROUGH/DRY LINE WITH APPROACH OF LEAD SHORT WAVE TROUGH. GENERALLY WEAK INSTABILITY WITH THIS LEAD TROUGH IS EXPECTED TO LIMIT SEVERE THREAT THROUGH 28/00Z. AN EXCEPTION MAY EXIST ACROSS WRN OK/ERN TX PANHANDLE WHERE MLCAPE MAY BE AROUND 500 J/KG BY LATE AFTERNOON...SUPPORTING A THREAT FOR ISOLATED HAIL/ STRONG WINDS. GREATER SEVERE THREAT...THOUGH STILL ISOLATED IN COVERAGE GIVEN TIME OF DAY AND SOMEWHAT WEAK INSTABILITY...IS EXPECTED AFTER 28/00Z AS STEEPER MID LEVEL LAPSE RATES/STRONGER FORCING SPREAD NEWD ACROSS CENTRAL/SRN PLAINS AHEAD OF STRONGER IMPULSE...NOW LOCATED OVER CENTRAL CA. THIS ACTIVITY AND ATTENDANT SEVERE THREAT SHOULD DEVELOP NEWD AND MAY REACH PARTS OF IA/WRN MO BY 12Z TUESDAY. ..PETERS/TAYLOR.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 12:39:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 07:39:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271241 SWODY1 SPC AC 271239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 AM CST MON NOV 27 2006 VALID 271300Z - 281200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH IS IN PLACE THIS MORNING OVER MOST OF THE CENTRAL AND WESTERN UNITED STATES...WHILE UPPER RIDGE REMAINS ACROSS THE SOUTHEAST. ONE SHORTWAVE TROUGH NOTED ON WATER VAPOR IMAGERY OVER NM WILL TRACK NORTHEASTWARD ACROSS THE CENTRAL PLAINS TODAY. SURFACE BAROCLINIC ZONE LIES ALONG AN AXIS FROM THE NORTHWEST TX PANHANDLE INTO NORTHEAST KS...AND WILL MOVE VERY LITTLE THROUGH 00Z. INCREASINGLY STRONG SOUTHERLY LOW LEVEL WINDS WILL CONTINUE TO HELP TRANSPORT MOIST AND MARGINALLY UNSTABLE AIR MASS NORTHWARD ACROSS TX/OK/KS. FORCING FOR LARGE SCALE ASCENT WILL INCREASE BY LATE MORNING ALONG FRONTAL ZONE AS UPPER TROUGH APPROACHES. THIS IS EXPECTED TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS FROM WESTERN OK INTO KS AND NORTHWEST MO. FORECAST SOUNDINGS SHOW ONLY MARGINAL LAPSE RATES. HOWEVER...STRENGTH OF WIND FIELDS/VERTICAL SHEAR COUPLED WITH SUFFICIENT INSTABILITY MAY LEAD TO AN ISOLATED STRONG/SEVERE STORM THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND HAIL. THREAT SHOULD BE RESTRICTED TO A NARROW ZONE ALONG AND IMMEDIATELY EAST OF FRONTAL ZONE. ELSEWHERE IN THE NATION...ISOLATED THUNDERSTORMS WILL BE POSSIBLE ALONG THE PACIFIC NORTHWEST COAST AND THE INTERMOUNTAIN WEST. NO SEVERE STORMS ARE FORECAST IN THESE REGIONS. ..HART/TAYLOR.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 16:21:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 11:21:33 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271624 SWODY1 SPC AC 271621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1021 AM CST MON NOV 27 2006 VALID 271630Z - 281200Z ...NO SVR TSTM AREAS FORECAST... LARGE COLD UPPER TROUGH CONTINUES TO DEEPEN OVER WRN U.S WITH A BROAD SWLY FLOW FROM THE ROCKIES TO THE APPALACHIANS. LEADING EDGE OF THE ARCTIC AIR FROM CENTRAL IA TO NWRN OK/TX PANHANDLE WILL BEGIN RETREATING NWD INTO KS THIS AFTERNOON AS PRESSURE FALLS DEVELOP LEE OF ROCKIES. MODIFIED GULF MOISTURE CONTINUES TO STREAM NWD/NEWD THRU SRN/CENTRAL PLAINS ON 30KT LOW LEVEL JET. LIMITED POTENTIAL INSTABILITY IN WARM SECTOR WITH LAPSE RATES GENERALLY LESS THAN 7C/KM AND EXTENSIVE CLOUDINESS. S/WV TROUGH EMBEDDED IN THE FLOW AROUND DEEP WESTERN SYSTEM CURRENTLY ROTATING NEWD FROM NM ACROSS THE PLAINS THIS AFTERNOON. GIVEN THE LIFT PROVIDED BY THE FRONT AND MLCAPES FROM 300-500 J/KG THIS AFTERNOON...THUNDERSTORMS EXPECTED TO DEVELOP VICINITY AND JUST E OF FRONTAL ZONE. WITH DEEP LAYER SHEAR FROM 40-50 KTS A FEW OF THE STORMS COULD BECOME STRONG/BRIEFLY SEVERE THIS AFTERNOON AND EVENING. COVERAGE AND EXPECTED LIMITED INTENSITY PRECLUDES A SLIGHT RISK. ..HALES/JEWELL.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 19:45:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 14:45:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271947 SWODY1 SPC AC 271945 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0145 PM CST MON NOV 27 2006 VALID 272000Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SRN THROUGH CNTRL PLAINS... SERIES OF SHORT WAVE DISTURBANCES PIVOTING AROUND DEEP UPPER TROUGH ACROSS THE WEST WILL CONTINUE TO AID LARGE SCALE ASCENT OVER THE GREAT PLAINS THROUGH TONIGHT. THESE DISTURBANCES WILL ACT IN CONCERT WITH LOW LEVEL ISENTROPIC LIFT ACROSS A SHARP FRONTAL ZONE FROM TX/OK TO IA/WI TO PRODUCE SCATTERED CONVECTION. LOW LEVEL MOISTURE TRANSPORT AND A PLUME OF STEEPER MID LEVEL LAPSE RATES FROM THE SRN HIGH PLAINS ACROSS THE MO RIVER VALLEY WERE CONTRIBUTING TO POCKETS OF MUCAPE IN THE RANGE OF 300-800 J/KG. STRONGER ASCENT...ASSOCIATED WITH AN IMPULSE NOW MOVING TOWARD THE AZ/NM BORDER...SHOULD RESULT IN A GRADUAL INCREASE IN TSTM ACTIVITY ACROSS THE SRN PLAINS AREA THROUGH THIS EVENING. WHILE BOUNDARY LAYER AIR MASS BENEATH THIS INCREASING CONVECTION IS EXPECTED TO REMAIN QUITE STABLE...LAPSE RATES AND SHEAR IN THE CLOUD-BEARING LAYER COULD SUPPORT ISOLATED AND MARGINALLY SEVERE HAIL FROM WRN OK...ACROSS PARTS OF KS...AND INTO NWRN MO AND SWRN IA THROUGH LATE TONIGHT/EARLY TUESDAY. ..CARBIN.. 11/27/2006  From swody1 at goshenarc.org Tue Nov 28 00:58:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 19:58:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280100 SWODY1 SPC AC 280058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 PM CST MON NOV 27 2006 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SRN THROUGH CENTRAL PLAINS/MID MO VALLEY TO WI... SERIES OF SHORT WAVE DISTURBANCES /ONE CURRENTLY LOCATED OVER SWRN IA/ERN KS AND THE SECOND OVER THE SRN ROCKIES/ PIVOTING AROUND DEEP UPPER TROUGH ACROSS THE WEST WILL CONTINUE TO AID LARGE SCALE ASCENT OVER THE GREAT PLAINS THROUGH TONIGHT. THIS ASCENT WILL ACT IN CONCERT WITH LOW LEVEL ISENTROPIC LIFT ACROSS A SHARP FRONTAL ZONE FROM TX/OK TO IA/WI TO PRODUCE SCATTERED CONVECTION. LOW LEVEL MOISTURE TRANSPORT ALONG/E OF SURFACE FRONT WILL PERSIST THIS FORECAST PERIOD...AS KS/IA PORTION OF FRONT RETREATS NWD IN RESPONSE TO HEIGHT FALLS/SURFACE PRESSURE FALLS OVER THE NRN PLAINS TO UPPER MS VALLEY. INCREASING DEEP LAYER ASCENT/STEEPER LAPSE RATES SPREADING NEWD ACROSS THE SRN/CENTRAL PLAINS WITH APPROACH OF STRONGER SRN ROCKIES SHORT WAVE TROUGH SUGGEST GREATER DESTABILIZATION/TSTM DEVELOPMENT SHOULD OCCUR FROM OK TO ERN NEB. MOST OF THESE STORMS SHOULD BE LOCATED ATOP STABLE BOUNDARY LAYER AIR...NORTH OF FRONTAL ZONE...WHERE LAPSE RATES AND SHEAR IN CLOUD-BEARING LAYER COULD SUPPORT ISOLATED AND MARGINALLY SEVERE HAIL. ENHANCED LOW LEVEL SHEAR ALONG THE SURFACE FRONT MAY SUPPORT AN ISOLATED TORNADO ACROSS NRN OK/KS PORTION OF FRONT WHICH IS CLOSER TO STRONGER MOISTURE FEED. ...NERN NV/NRN UT TO SWRN WY... COLD MID LEVEL TEMPERATURES /AROUND -30 C AT 500 MB/ AND ASCENT WITH SHORT WAVE TROUGH...CURRENTLY LOCATED OVER NERN NV/SRN ID...WILL CONTINUE TO SUPPORT CONVECTIVE DEVELOPMENT AND EMBEDDED TSTMS ACROSS NRN UT INTO SWRN WY THIS EVENING. ..PETERS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 05:19:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 00:19:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280521 SWODY1 SPC AC 280519 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 PM CST MON NOV 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... WRN U.S. TROUGH WILL CONTINUE TO AMPLIFY AND MOVE EWD TODAY TOWARD THE ROCKIES AND PLAINS...AS A STRONG NLY MID/UPPER LEVEL JETS TRANSLATE SEWD ALONG THE WRN PERIPHERY OF THIS FEATURE FROM THE BC COAST INTO THE WRN STATES. MEANWHILE...SHORT WAVE TROUGH MOVING INTO THE CENTRAL/SRN PLAINS PRIOR TO 12Z TODAY WILL TRACK NEWD WITHIN STRENGTHENING BAND OF SWLY MID/UPPER LEVEL FLOW ALONG ERN PERIPHERY OF WRN U.S. LONG WAVE TROUGH. IN THE LOW LEVELS...PRIMARY SURFACE LOW SHOULD INITIALLY BE LOCATED OVER SD/NEB AND THEN MOVE NNEWD...REACHING SRN MANITOBA/WRN ONTARIO BY 12Z WEDNESDAY. A STRONG ARCTIC FRONT TRAILING THIS LOW WILL SPREAD E AND S ACROSS THE NRN INTO CENTRAL PLAINS AND UPPER MS VALLEY. WARM SECTOR IS EXPECTED TO SPREAD NWD INTO SERN MN/WI...IN ADVANCE OF THE APPROACHING COLD FRONT...WITH LOWER 50S SURFACE DEWPOINTS REACHING THAT REGION BY MID-LATE AFTERNOON. AT 12Z TODAY...CLUSTERS OF TSTMS SHOULD BE ONGOING ACROSS ERN PARTS OF THE CENTRAL/SRN PLAINS INTO THE MID MO VALLEY...WITHIN ZONE OF DEEP LAYER ASCENT AND STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE CENTRAL/SRN PLAINS SHORT WAVE TROUGH. A FEW OF THE STRONGER STORMS MAY BE CAPABLE OF PRODUCING SMALL TO POTENTIALLY MARGINALLY SEVERE HAIL THIS MORNING...THOUGH THIS THREAT APPEARS TOO MARGINAL TO INCLUDE SEVERE PROBABILITIES. AS THE LEAD TROUGH TRACKS TOWARD SRN CANADA...THIS ONGOING ACTIVITY IS EXPECTED TO LIFT NEWD TO THE WRN GREAT LAKES REGION BY AFTERNOON...BUT SHOULD TEND TO DECREASE IN INTENSITY AS IT MOVES AWAY FROM BETTER INSTABILITY. ADDITIONAL TSTMS ARE PROGGED TO DEVELOP ALONG THE COLD FRONT FROM SERN NEB TO ERN MN AS THIS BOUNDARY ADVANCES ESE INTO THE MID MO/ UPPER MS VALLEYS BY 29/00Z...WHERE THE RETREATING MOIST WARM SECTOR WILL HAVE RESULTED IN MARGINAL INSTABILITY. SOME OF THIS ACTIVITY MAY BECOME STRONG PRODUCING ISOLATED SEVERE GIVEN FORECAST OF STRONG VERTICAL SHEAR PROFILES. THESE STORMS SHOULD SPREAD EWD AND MAY ALSO DEVELOP SWD ALONG FRONT INTO ERN KS/MO. SEVERE THREAT APPEARS TOO MARGINAL TO INCLUDE PROBABILITIES...GIVEN THE EFFECTS OF THE MARGINAL INSTABILITY. ..PETERS/GRAMS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 12:18:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 07:18:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281220 SWODY1 SPC AC 281218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST TUE NOV 28 2006 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL STATES... AN EXPANSIVE UPPER TROUGH IS IN PLACE THIS MORNING OVER MOST OF THE UNITED STATES...WITH THE EXCEPTION OF THE SOUTHEAST STATES. SEVERAL SMALLER FEATURES ARE ROTATING THROUGH THE TROUGH...RESULTING IN POCKETS OF PRECIPITATION THROUGHOUT THE WESTERN AND CENTRAL UNITED STATES. THE STRONGEST SHORTWAVE TROUGH IS NOW MOVING ACROSS WESTERN OK. STRONG FORCING FOR LARGE SCALE ASCENT IS OCCURRING AHEAD OF TROUGH ACROSS PARTS OF OK/KS/MO/NEB/IA/MN...WHERE SCATTERED THUNDERSTORMS ARE NOTED. THIS ACTIVITY WILL MOVE EASTWARD INTO PARTS OF WI/IL/AR AND WEAKEN THROUGH THE DAY AS IT ENCOUNTERS MORE STABLE AIR MASS. SMALL HAIL WILL BE POSSIBLE IN STRONGER STORMS THIS MORNING...BUT ORGANIZED SEVERE ACTIVITY IS NOT ANTICIPATED. ...CO/WY... ELSEWHERE...SHOWERS AND ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE OVER THE HIGHER TERRAIN OF CO AND SOUTHERN WY THIS AFTERNOON AS DIURNAL HEATING...COLD TEMPERATURES ALOFT...AND SERIES OF SHORTWAVE TROUGHS AFFECT THE AREA. OVERALL THREAT OF DEEP CONVECTION APPEARS TOO MARGINAL TO OUTLOOK AT THIS TIME. ..HART/GRAMS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 16:26:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 11:26:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281628 SWODY1 SPC AC 281626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1026 AM CST TUE NOV 28 2006 VALID 281630Z - 291200Z ...NO SVR TSTM AREAS FORECAST... STRONG VERY COLD UPPER TROUGH WRN U.S. CONTINUES TO DEEPEN AS IT SLOWLY SHIFTS EWD. ONE STRONG IMPULSE LIFTING NEWD INTO SCENTRAL CANADA WHILE 140KT NLY POLAR JET PAC NW SUPPORTS CONTINUED AMPLIFICATION OVER CENTRAL/SRN ROCKIES. SURFACE LOW AHEAD OF ARCTIC FRONT OVER DAKOTAS TRACKS NEWD AS ARCTIC AIR CONTINUES TO PRESS SEWD THRU THE HIGH PLAINS. PAC FRONTAL ZONE EXTENDS FROM SURFACE LOW ERN CO SWWD INTO NRN AZ. THIS LOW WILL MOVE INTO TX PANHANDLE TONIGHT WITH PAC FRONT TRAILING WSWWD ACROSS AZ. AHEAD OF THESE SYSTEMS AND UPPER TROUGH THE STRONG SLY FLOW OF UNSEASONABLY WARM/MOIST AIR FROM THE PLAINS TO UPPER MS VALLEY WILL PERSIST THRU THE PERIOD. THE ACTIVE OVERNIGHT CONVECTION ACROSS THE PLAINS WAS TIED TO WEAKENING S/WV TROUGH NOW LIFTING NEWD ACROSS UPPER MS VALLEY. WHILE THE LOW LEVEL AIR MASS REMAINS MOIST...MID LEVEL VEERING/DRYING AND SUBSIDENCE IN WAKE OF S/WV TROUGH WILL PRECLUDE THREAT FOR STRONG/SEVERE THUNDERSTORMS MUCH OF THIS FORECAST PERIOD. OVERNIGHT WITH WARM ADVECTION AND DEEPENING MOISTURE INDICATED IN MODEL SOUNDINGS ACROSS THE CENTAL/SRN PLAINS AHEAD OF THE APPROACHING LARGE SCALE UPPER TROUGH...THERE IS SOME CONCERN THAT STRONG STORMS COULD DEVELOP. MODELS STILL INDICATING THE PRIMARY THREAT OF SEVERE THUNDERSTORMS WILL BE AFTER 12Z WED...SO FOR NOW WILL NOT INTRODUCE ANY SEVERE THREAT BUT TAKE ANOTHER LOOK AT THIS AREA DURING AFTERNOON DAY1 UPDATE. ..HALES/TAYLOR.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 19:50:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 14:50:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281953 SWODY1 SPC AC 281951 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0151 PM CST TUE NOV 28 2006 VALID 282000Z - 291200Z ...NO SVR TSTM AREAS FORECAST... SCATTERED TSTMS PERSIST WITHIN WARM AIR ADVECTION REGIME ON THE APEX OF LOW LEVEL MOIST AXIS FROM SERN MN ACROSS WI AND NRN IL THIS AFTERNOON. THIS ACTIVITY WAS BEING FURTHER SUPPORTED BY A LOW AMPLITUDE SHORT WAVE TROUGH EJECTING NEWD ACROSS THE REGION. ADDITIONAL ISOLATED TSTMS HAVE RECENTLY DEVELOPED AHEAD OF A STRONG COLD FRONT MOVING ACROSS IA. DEEP-LAYER SLY/SWLY FLOW BETWEEN STRONG WRN U.S. TROUGH AND SERN U.S RIDGE WILL MAINTAIN A CORRIDOR OF HIGHER BOUNDARY LAYER MOISTURE TOPPED BY GENERALLY WEAK MID LEVEL LAPSE RATES FROM THE SRN PLAINS ACROSS THE MO RIVER VALLEY THROUGH TONIGHT. MUCAPE VALUES WITHIN MUCH OF THIS CORRIDOR ARE EXPECTED TO REMAIN WEAK/MARGINAL WITH THE POSSIBLE EXCEPTION OF THE TX/OK AREAS WHERE MUCAPE IS FORECAST TO INCREASE TO AROUND 1000 J/KG THROUGH THE REMAINDER OF THIS FORECAST PERIOD. COLD FRONT ASSOCIATED WITH THE WRN LARGE SCALE TROUGH WILL EDGE STEADILY ESEWD ACROSS THE MO VALLEY AND MUCH OF KS THROUGH TONIGHT. A NARROW WARM CONVEYOR BELT AIDED BY NOCTURNAL INCREASE IN LOW LEVEL JET WILL PRECEDE THE FRONT FROM OK NEWD ACROSS ERN KS/WRN MO AND WILL RESULT IN INCREASING ASCENT NEAR AND ACROSS THE BOUNDARY. CONVECTION IS EXPECTED TO GRADUALLY DEVELOP WITHIN THE CONVEYOR BELT AND ALONG/BEHIND THE COLD FRONTAL CIRCULATION AS IT DEVELOPS INTO THE MOIST AXIS THROUGH THE NIGHT. WHILE FORCING...SHEAR...AND INSTABILITY ACROSS THE REGION APPEAR SUFFICIENT TO MAINTAIN AREAS OF DEEP CONVECTION...WEAK LAPSE RATES ARE LIKELY TO TEMPER SEVERE WEATHER /HAIL/ POTENTIAL UNTIL AFTER DAYBREAK WEDNESDAY. ..CARBIN.. 11/28/2006  From swody1 at goshenarc.org Wed Nov 29 00:51:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 19:51:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290054 SWODY1 SPC AC 290052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST TUE NOV 28 2006 VALID 290100Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...NERN OK/NWRN AR/SERN KS INTO SWRN AND CENTRAL MO... SURFACE LOW LOCATED OVER NRN MN AND ASSOCIATED WITH SHORT WAVE TROUGH NOW MOVING NEWD INTO ONTARIO WILL TEND TO TRACK MORE NWD OVERNIGHT IN RESPONSE TO STRONG HEIGHT FALLS EXPECTED OVER ND/SRN MANITOBA AS ERN MT SHORT WAVE TROUGH APPROACHES SRN CANADA. COLD FRONT TRAILING SWD FROM THIS LOW WILL CONTINUE EWD INTO THE WRN GREAT LAKES REGION AND SEWD INTO THE MID MS VALLEY AND SRN PLAINS...AS LARGE SCALE WRN TROUGH EDGES EWD. TSTMS WILL REMAIN POSSIBLE AS THE PROGRESSIVE COLD FRONT MOVES INTO A NARROW MOIST AXIS AHEAD OF THIS BOUNDARY. WEAK MID LEVEL LAPSE RATES SHOULD LIMIT UPDRAFT STRENGTH AND ANY SEVERE THREAT ALONG THE NRN EXTENT OF THE FRONT INTO THE WRN GREAT LAKES REGION. FARTHER S...TSTMS SHOULD DEVELOP LATER TONIGHT...LIKELY AFTER 06Z... FROM ERN KS/NERN OK AS THE COLD FRONT ADVANCES SEWD AND SWLY LLJ EXTENDING FROM TX/ERN OK TO OZARK PLATEAU STRENGTHENS. DEEP LAYER ASCENT IS EXPECTED TO INCREASE ACROSS THIS REGION LATE TONIGHT DUE TO WAA ALONG NOSE OF LLJ AND WITHIN EXIT REGION OF 70 KT MID LEVEL JET APPROACHING FROM THE SRN HIGH PLAINS. LOW LEVEL MOIST/WARM AIR ADVECTION BENEATH STEEPER MID LEVEL LAPSE RATES ACCOMPANYING SRN HIGH PLAINS JETLET SHOULD SUPPORT MUCAPE 500-1000 J/KG. THIS COMBINED WITH INCREASING EFFECTIVE BULK SHEARS SUGGEST POTENTIAL FOR ROTATING STORMS. STRONGER STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED HAIL AND/OR STRONG WIND GUSTS AS ACTIVITY SPREADS INTO NWRN AR TO CENTRAL MO. ..PETERS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:34:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:34:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290636 SWODY1 SPC AC 290556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:43:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:43:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290645 SWODY1 SPC AC 290556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:56:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:56:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290658 SWODY1 SPC AC 290657 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CST WED NOV 29 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... RESENT PER REQUEST ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 12:46:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 07:46:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291248 SWODY1 SPC AC 291245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 AM CST WED NOV 29 2006 VALID 291300Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO THE MID MISSISSIPPI VALLEY... POWERFUL SHORTWAVE TROUGH NOW OVER WESTERN NM WILL TRACK EASTWARD AND INTO THE SOUTHERN PLAINS TODAY. MEANWHILE...ARCTIC COLD FRONT WILL SURGE SOUTHEASTWARD THROUGH WESTERN MO/OK/NORTHWEST TX. INCREASINGLY MOIST AND MODERATELY UNSTABLE AIR MASS IS IN PLACE AHEAD OF FRONT WHERE SURFACE DEWPOINTS ARE IN THE LOW-MID 60S. SCATTERED THUNDERSTORMS ARE BEGINNING TO FORM ALONG FRONT FROM NORTH-CENTRAL OK INTO WESTERN MO. THIS TREND IS LIKELY TO CONTINUE THROUGH THE MORNING WITH DEVELOPMENT AS FAR SOUTH AS THE RED RIVER EXPECTED. THESE STORMS ARE LIKELY TO BE QUICKLY UNDERCUT BY FAST-MOVING FRONT. HOWEVER...MORNING OBSERVED AND MODEL FORECAST SOUNDINGS IN THIS ZONE SHOW SUFFICIENT CAPE AND DEEP LAYER VERTICAL SHEAR FOR A RISK OF HAIL IN STRONGEST CELLS. AIR MASS OVER CENTRAL AND NORTH-CENTRAL TX IS EXPECTED TO BECOME MODERATELY UNSTABLE BY EARLY AFTERNOON...WITH DEWPOINTS IN THE MID 60S ALONG/EAST OF DRYLINE. STRONG HEATING WEST OF THE DRYLINE... COOLING MID LEVEL TEMPERATURES...AND INCREASING LARGE SCALE FORCING WILL ENHANCE DESTABILIZATION AND LIKELY LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT. FORECAST SOUNDINGS IN THIS AREA SHOW VERY FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR PROFILES FOR SUPERCELLS CAPABLE OF DAMAGING WINDS AND ISOLATED TORNADOES. THIS ACTIVITY WILL LIKELY INCREASE IN AREAL COVERAGE THROUGH THE AFTERNOON/EARLY EVENING AND SPREAD INTO PARTS OF SOUTHEAST OK AND WESTERN AR. VERY STRONG WIND FIELDS AT ALL LEVELS WILL PROMOTE THE POTENTIAL FOR DAMAGING WINDS...AS WELL AS LARGE HAIL. STORMS WILL LIKELY PERSIST THROUGH THE NIGHT INTO PARTS OF MO/IL...WHERE STRONG WIND FIELDS MAY BE SUFFICIENT TO MAINTAIN ISOLATED SEVERE THREAT DESPITE VERY MARGINAL INSTABILITY. ..HART/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 16:05:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 11:05:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291606 SWODY1 SPC AC 291604 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1004 AM CST WED NOV 29 2006 VALID 291630Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO THE MID MISSISSIPPI VALLEY... POWERFUL S/WV TROUGH WILL CROSS NM THIS AFTERNOON REACHING SRN PLAINS OVERNIGHT. STRONG ARCTIC FRONT AT 15Z FROM NERN MO TO CENTRAL OK/SRN TX PANHANDLE CONTINUES PRESSING SEWD. STRONG SLY FLOW OFF WRN GULF OF MEXICO CONTINUES TO INCREASE MOISTURE AND INSTABILITY NWD THRU SRN PLAINS INTO MID MS VALLEY AHEAD OF THE FRONT. THUNDERSTORMS ARE DEVELOPING ALONG AND TO COLD SIDE OF SHALLOW ARCTIC FRONT THIS AM FROM WRN IL TO NRN OK. WITH MARGINAL INSTABILITY AND STRONG DEEP LAYER SHEAR...INITIAL THREAT WILL BE HAIL AND LOCAL DAMAGING WINDS WITH STORMS THAT DEVELOP ALONG FRONTAL ZONE THRU THE EARLY AFTERNOON FROM OK TO WRN IL. ELEVATED INSTABILITY WILL ALSO RESULT IN MARGINALLY SEVERE HAIL THREAT SOME DISTANCE TO THE COLD SIDE OF SURFACE FRONT. FURTHER S WARM SECTOR AIR MASS WILL BECOME SUPPORTIVE OF SURFACE BASED THUNDERSTORMS AHEAD OF THE FRONT ACROSS NRN TX BY MID AFTERNOON WHERE MLCAPES WILL CLIMB TO AOA 2000 J/KG. GIVEN 50-60 KT OF DEEP LAYER SHEAR...SUPERCELLS ARE LIKELY ENHANCING BOTH THE LARGE HAIL AND TORNADO POTENTIAL. STORMS SHOULD SPREAD E/NEWD ACROSS NRN TX/SERN OK INTO WRN AR THIS EVENING WITH APPROACH OF STRONG UPPER SUPPORT FROM THE W. ..HALES/GUYER.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 19:56:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 14:56:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291958 SWODY1 SPC AC 291956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST WED NOV 29 2006 VALID 292000Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX NEWD TO MO/IL... ...NRN TX/SERN OK/NWRN AR... POWERFUL COLD FRONT CONTINUES TO SPREAD SEWD ACROSS NWRN TX AND SERN OK LATE THIS AFTERNOON. MOIST AND INCREASING UNSTABLE AIR MASS WAS DEVELOPING AHEAD OF AND ACROSS THE VERY SHARP FRONT AND CONTRIBUTING TO AN EXPANDING AREA OF DEEP CONVECTION FROM THE RED RIVER VALLEY NEWD ACROSS ECNTRL OK...AND INTO PARTS OF SERN KS AND WRN MO. SO FAR...THE BULK OF THIS CONVECTION HAS OCCURRED ON THE IMMEDIATE COLD SIDE OF THE SURFACE FRONT. HOWEVER...THAT HAS BEGUN TO CHANGE ACROSS NORTH TX WHERE NEAR SURFACE-BASED STORMS APPEAR TO HAVE FORMED OVER THE PAST 1-2 HOURS. EXPECT TREND OF PRE-FRONTAL SURFACE-BASED CONVECTIVE DEVELOPMENT TO CONTINUE ACROSS PARTS OF NRN TX...SERN OK...AND WRN AR THROUGH THIS EVENING. LATEST OBJECTIVE ANALYSIS DATA SUGGESTS THAT MLCAPE OF 1000-1500 J/KG AND STRONG SHEAR ACROSS THESE AREAS WILL INITIALLY SUPPORT SUPERCELLULAR STORMS WITH SOME POTENTIAL FOR A TORNADO OR TWO...IN ADDITION TO DAMAGING WINDS AND LARGE HAIL. EXPECT THIS ACTIVITY TO BECOME INCREASINGLY LINEAR AND UNDERCUT BY DEEPENING SYNOPTIC COLD POOL AS THE FRONT MAKES GRADUAL SEWD PROGRESS THROUGH THE NIGHT. LARGE SCALE ASCENT ASSOCIATED WITH AN INTENSE SHORT WAVE TROUGH APPROACHING FROM NM THROUGH LATE TONIGHT WILL AID IN STEEPENING MID LEVEL LAPSE RATES ATOP THE SURFACE-BASED COLD DOME. IN COMBINATION WITH PERSISTENT MOIST ISENTROPIC LIFT ACROSS THE FRONTAL ZONE...DEEP CONVECTION WITH THE CHANCE FOR HAIL WILL LIKELY REMAIN A THREAT ACROSS PARTS OF TX/OK THROUGH LATE TONIGHT. ...MO/IL... AFTERNOON SOUNDINGS FROM SGF AND ILX INDICATED WEAKER LAPSE RATES AND MARGINAL INSTABILITY /MUCAPE AROUND 700 J PER KG/ IN THE PRE-FRONTAL ENVIRONMENT ACROSS THESE AREAS. HOWEVER...LATEST GUIDANCE REMAINS CONSISTENT IN SUGGESTING A CONTINUING POTENTIAL FOR VIGOROUS CONVECTIVE DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT THROUGH THIS EVENING. THIS DEVELOPMENT WILL OCCUR WITHIN A SUFFICIENTLY STRONG FLOW REGIME WHERE UNIDIRECTIONAL SHEAR PROFILES FAVOR FAST-MOVING LINE SEGMENTS CAPABLE OF PRODUCING WIND DAMAGE AND PERHAPS MARGINALLY SEVERE HAIL. ..CARBIN.. 11/29/2006  From swody1 at goshenarc.org Thu Nov 30 00:56:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 19:56:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300058 SWODY1 SPC AC 300056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST WED NOV 29 2006 VALID 300100Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF TX AND SERN OK THROUGH THE MID MS VALLEY... ...S CNTRL THROUGH NERN TX...SERN OK NWRN AR AND SRN MO... ARCTIC COLD FRONT EXTENDS FROM THE GREAT LAKES REGION SWWD THROUGH CNTRL AND SWRN MO...SERN OK INTO N CNTRL THROUGH WRN TX. THIS FRONT WILL CONTINUE TO SETTLE SEWD THE REMAINDER OF TONIGHT. PRE-FRONTAL WARM SECTOR IS CHARACTERIZED BY LOW 60S DEWPOINTS FROM TX THROUGH SERN OK WITH UPPER 50S TO NEAR 60 FARTHER NE INTO THE MID MS VALLEY. MUCAPE FROM 500 TO 1000 J/KG EXISTS FROM CNTRL THROUGH NERN TX INTO SERN OK...BUT DECREASES TO BELOW 500 J/KG FARTHER NE INTO THE MID MS VALLEY WHERE MID LEVEL LAPSE RATES ARE WEAKER AND LOW LEVEL MOISTURE IS MORE LIMITED. STORMS SHOULD CONTINUE DEVELOPING THIS EVENING PRIMARILY WITHIN ZONE OF FORCED LOW LEVEL ASCENT ALONG THE ARCTIC FRONT FROM CNTRL THROUGH NERN TX INTO ERN OK AND THE MID MS VALLEY. ORIENTATION OF THE SWLY MID LEVEL FLOW WITH RESPECT TO THE FRONT HAS RESULTED IN STORMS BEING UNDERCUT AND BECOMING ELEVATED SOON AFTER INITIATION. THIS SUGGESTS THE PRIMARY THREAT WITH THIS ACTIVITY SHOULD BE HAIL...ESPECIALLY GIVEN 6.5-7 C/KM 850-500 MB LAPSE RATES PRESENT ON COOL SIDE OF FRONT. OVERALL HAIL THREAT WILL REMAIN LIMITED BY MODEST INSTABILITY. STRONGER FORCING FOR ASCENT ASSOCIATED WITH UPPER TROUGH OVER NM SHOULD REMAIN W OF THE WARM SECTOR OVERNIGHT. HOWEVER...WV IMAGERY SHOWS A LEAD IMPULSE MOVING NEWD INTO SWRN TX. SOME INCREASE IN THE SLY LOW LEVEL JET MAY OCCUR AHEAD OF THIS FEATURE ACROSS PARTS OF CNTRL TX THROUGH THE LOWER MS VALLEY. A FEW STORMS MAY CONTINUE DEVELOPING WITHIN WARM ADVECTION REGIME ACROSS CNTRL TX PRE-FRONTAL WARM SECTOR. STRONG DEEP LAYER SHEAR AND STRENGTHENING LOW LEVEL SHEAR WILL MAINTAIN A THREAT FOR ISOLATED SUPERCELLS WITH THIS ACTIVITY. HOWEVER...MODEST LAPSE RATES AND COOLING BOUNDARY LAYER SHOULD SERVE AS LIMITING FACTORS FOR A MORE ROBUST SEVERE THREAT. ..DIAL.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 06:00:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 01:00:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300603 SWODY1 SPC AC 300600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1200 AM CST THU NOV 30 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS AND TN VALLEYS INTO THE SERN U.S. AND A SMALL PART OF THE OH VALLEY... ...SYNOPSIS... STRONG SHORTWAVE TROUGH OVER NM WILL AMPLIFY ESEWD THROUGH THE SRN PLAINS THURSDAY BEFORE EJECTING NEWD INTO THE LOWER-MID MS VALLEY AND WRN TN VALLEY THURSDAY EVENING...REACHING THE OH VALLEY LATE THURSDAY NIGHT. ARCTIC FRONT SHOULD EXTEND FROM THE GREAT LAKES SWWD INTO AR AND SRN TX BY 12Z THURSDAY. CYCLOGENESIS WILL COMMENCE ALONG LOWER MS VALLEY PORTION OF FRONT THURSDAY AFTERNOON AS ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONIC UPPER JET BEGINS TO OVERTAKE WARM SECTOR. THE LOW WILL SUBSEQUENTLY DEEPEN AND LIFT NEWD INTO THE OH VALLEY OVERNIGHT. THIS SHOULD RESULT IN SRN PORTION OF THE COLD FRONT ACCELERATING EWD THROUGH THE TN VALLEY AND SERN U.S. THURSDAY EVENING AND NIGHT. ...SERN TX THROUGH THE LOWER MS AND TN VALLEYS AND SERN STATES... MODIFIED CP AIR WITH BOUNDARY LAYER DEWPOINTS MOSTLY IN THE LOW TO MID 60S WILL EXIST IN PRE-FRONTAL WARM SECTOR OVER THE LOWER MS VALLEY AND PORTIONS OF THE SERN STATES WITH NEAR 60 FARTHER N INTO THE TN AND OH VALLEYS. THIS MOISTURE WILL EXIST BELOW WEAK MID LEVEL LAPSE RATES WITH 5.5 C/KM EXPECTED IN THE 850-500 MB LAYER. THE WEAK LAPSE RATES AND LIMITED BOUNDARY LAYER HEATING SHOULD RESULT IN WEAK INSTABILITY WITH MLCAPE GENERALLY AOB 500 J/KG. BY 12Z THURSDAY STORMS WILL BE ONGOING MAINLY ON COLD SIDE OF ARCTIC FRONT FROM SERN TX INTO THE LOWER-MID MS VALLEY. ANY SEVERE THREAT WITH THIS ACTIVITY WILL BE MINIMAL DUE TO ELEVATED NATURE OF THE STORMS AND WEAK INSTABILITY. THREAT FOR SEVERE STORMS MAY INCREASE FARTHER EAST THURSDAY AFTERNOON INTO THURSDAY EVENING OVER PARTS OF THE LOWER MS VALLEY INTO THE TN VALLEY. DEEP LAYER FORCING ALONG FRONT WILL INCREASE IN THIS REGION AS THE SURFACE LOW DEEPENS AND LOW LEVEL JET STRENGTHENS. THIS MAY CONTRIBUTE TO A LINE OF LOW TOPPED CONVECTION...POSSIBLY WITH LITTLE OR NO LIGHTNING...ESPECIALLY FROM ERN AR...MS INTO WRN TN AND KY. WITH THE LOW LEVEL JET FORECAST TO STRENGTHEN TO 60+ KT...POTENTIAL WILL EXIST FOR MAINLY ISOLATED DAMAGING WIND ALONG THE LINE. SOME STORMS MAY BECOME UNDERCUT BY THE COLD AIR ACCOMPANYING EWD MOVING FRONT. HOWEVER...FRONT WILL BECOME ORIENTED MORE N-S DURING THE AFTERNOON S OF THE SURFACE LOW...AND THIS PORTION OF BOUNDARY MAY TREND TOWARD A KATAFRONT. THIS MAY SUPPORT A FEW SURFACE BASED STORMS BEING MAINTAINED ALONG THE SURFACE FRONT AS IT MOVES EWD THROUGH THE TN VALLEY AND SRN PORTIONS OF THE OH VALLEY. STRENGTHENING LOW-LEVEL AND CLOUD LAYER SHEAR PROFILES WOULD ALSO SUPPORT A THREAT OF SUPERCELL STRUCTURES EMBEDDED WITHIN THE LINE. ANY TORNADO THREAT WILL BE MAINLY LIMITED TO STORMS THAT CAN DEVELOP IN WARM SECTOR E OF ADVANCING COLD FRONT. HOWEVER...IT MAY BE DIFFICULT TO MAINTAIN DISCRETE UPRIGHT CONVECTION AWAY FROM THE FRONT IN SUCH A STRONGLY SHEARED ENVIRONMENT...AND THIS MAY SERVE AS A LIMITING FACTOR FOR A MORE ROBUST TORNADO THREAT. ..DIAL/GRAMS.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 12:41:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 07:41:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301243 SWODY1 SPC AC 301240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST THU NOV 30 2006 VALID 301300Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE LOWER MS AND TN VALLEYS... ...LOWER MS AND TN VALLEYS... VIGOROUS UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD ACROSS NM...AND IS FORECAST TO EJECT EASTWARD ACROSS THE SOUTHERN PLAINS THROUGH TONIGHT. AS IT DOES SO...SYSTEM DEEPENS RAPIDLY AND MID LEVEL JET STRENGTHENS TO OVER 120 KNOTS. THIS PROCESS WILL RESULT IN VERY STRONG LARGE SCALE FORCING FOR ASCENT SPREADING ACROSS THE LOWER/MID MS VALLEY THIS EVENING. MODEL GUIDANCE IS IN GENERAL AGREEMENT THAT SURFACE LOW WILL DEEPEN OVER SOUTHERN AR BY MID AFTERNOON AND TRACK NORTHEASTWARD INTO WESTERN KY/TN. STRENGTHENING SOUTHERLY LOW LEVEL WINDS AHEAD OF LOW WILL DRAW INCREASINGLY MOIST/UNSTABLE AIR NORTHWARD WITH MID 60S DEWPOINTS EXPECTED INTO WESTERN TN. WEAK MID LEVEL LAPSE RATES WILL SUPPRESS THE DEVELOPMENT OF MORE THAN MARGINAL INSTABILITY IN WARM SECTOR. HOWEVER...EXTREMELY STRONG WIND FIELDS AND FORCING NEAR SURFACE LOW WILL LIKELY RESULT IN A LINE OF STRONG/SEVERE THUNDERSTORMS. THIS ACTIVITY WILL LIKELY FORM OVER SOUTHEAST AR/NORTHEAST LA AND RACE INTO PARTS OF KY/TN/MS BEFORE 06Z. DAMAGING WINDS ARE THE MOST LIKELY SEVERE THREAT. HOWEVER...INTENSE FORCING AND STRENGTH OF WIND FIELDS /OVER 100 KNOTS AT 500MB AND OVER 60 KNOTS AT 850MB/ SUGGEST THE POTENTIAL FOR TORNADOES IN ANY PERSISTENT SUPERCELLS THAT CAN FORM WITHIN OR AHEAD OF THE LINE. ..HART/GRAMS.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 16:23:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 11:23:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301625 SWODY1 SPC AC 301623 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1023 AM CST THU NOV 30 2006 VALID 301630Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE LOWER MS AND TN VALLEYS...... ....LOWER MS AND TN VALLEYS... CYCLOGENESIS IS JUST BEGINNING SWRN AR IN ADVANCE OF THE VIGOROUS TROUGH CURRENTLY ENTERING SRN PLAINS. BY LATER THIS AFTERNOON AND OVERNIGHT THE SURFACE LOW WILL DEEPEN RAPIDLY IN RESPONSE TO THE VERY STRONG UPPER SUPPORT FROM THE INTENSIFYING UPPER TROUGH MOVING ENEWD ACROSS THE SRN PLAINS TO THE LOWER OH VALLEY LATE TONIGHT. LEADING EDGE OF THE ARCTIC AIR MASS CURRENTLY SERN IL TO SURFACE LOW SWRN AR THEN TO S TX. FRONT TO NE OF DEVELOPING LOW WILL MOVE LITTLE TODAY WHILE IT PUSHES RAPIDLY SEWD OFF TX COAST. WHILE THE WARM SECTOR IS VERY MOIST WITH MID 60 DEWPOINTS SURGING NWD BY THIS AFTERNOON THRU MS INTO WRN TN...THE WEAK LAPSE RATES AND WARM MID/UPPER LEVELS IS GREATLY LIMITING THE INSTABILITY AVAILABLE FOR DEEP CONVECTION. MLCAPES OF JUST 200-400 J/KG ARE ABOUT ALL THAT CAN BE EXPECTED IN THE WARM SECTOR THRU TONIGHT. HOWEVER THE EXTREMELY STRONG WIND FIELDS AND FORCING AHEAD OF THE DEEPENING SURFACE LOW WILL RESULT IN THE DEVELOPMENT OF A LINE OF STRONG/SEVERE THUNDERSTORMS. THIS ACTIVITY WILL LIKELY FORM OVER SERN AR/NERN LA THIS AFTERNOON AND RACE NEWD ACROSS LOWER MS VALLEY AND PARTS OF KY/TN/MS PRIOR TO 06Z. DAMAGING WINDS ARE THE PRIMARY THREAT GIVEN THE INTENSE FORCING AND STRENGTH OF WIND FIELDS/OVER 100KT AT 500MB AND CLOSE TO 70 KT AT 850MB OVERNIGHT. THERE WILL ALSO BE POTENTIAL FOR ISOLATED TORNADOES WITH ANY SUPERCELL THAT CAN FORM WITHIN OR JUST AHEAD OF THE SQUALL LINE. ..HALES/GUYER.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 19:55:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 14:55:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301957 SWODY1 SPC AC 301955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST THU NOV 30 2006 VALID 302000Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE LWR MS VLY INTO THE MID-SOUTH AND LWR OH VLY... ...LWR MS AND TN VLYS... 19Z SFC ANALYSIS PLACES 1007 MB LOW VCNTY KHOT WITH A COLD FRONT SWD INTO NWRN LA AND ANOTHER FRONT NEWD INTO THE KMEM VCNTY TO THE OH VLY. THE LOW SHOULD BEGIN TO INTENSIFY RAPIDLY THIS AFTN AS THE PRIMARY UPPER LOW APPROACHES WRN OK...WITH A TRACK NEWD TO KMEM BY 06Z AND INTO WRN IND BY 12Z. THE COLD FRONT SHOULD CONTINUE SWEEPING EWD THROUGH THE LWR MS VLY WHILE THE FRONT IN THE OH VLY RETREATS NWWD. DEVELOPMENT OF A LOW-TOPPED QUASI-LINEAR CONVECTIVE SYSTEM (QLCS) APPEARS IMMINENT VCNTY THE COLD FRONT FROM CNTRL AR SWD INTO NRN LA EARLY THIS AFTN. AHEAD OF THE FRONT...18Z RAOBS AND SELECTED ACARS SOUNDINGS SUGGEST THAT LAPSE RATES ARE MARGINAL GIVEN THE WARM LAYER ALOFT. BUT...VSBL SATL SHOWS MODEST INSOLATION OCCURRING THROUGH THE LWR MS VLY INTO THE MID-SOUTH. THIS WILL TEND TO DESTABILIZE THE BOUNDARY LAYER AND LESSEN THE INHIBITION SUFFICIENTLY TO SUPPORT MLCAPES TO AROUND 500 J/KG. THUS...COMBINATION OF STRONG LARGE SCALE ASCENT AND MARGINAL BUOYANCY WILL LIKELY CONTRIBUTE TO INCREASING INTENSITY TO THE QLCS LATE AFTN INTO THE EVE FROM SERN/ECNTRL AR AND NERN LA NEWD INTO THE MID-SOUTH AND LWR OH VLY. PRE-FRONTAL LOW-LEVEL SHEAR PROFILES ARE NOT PARTICULARLY STRONG PRIMARILY DUE TO THE LACK OF DIRECTIONAL SHEAR ABOVE THE SFC. THIS MAY CHANGE DURING THE NEXT SEVERAL HOURS...ESPECIALLY VCNTY THE SFC LOW TRACK. THUS...IT APPEARS THAT DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT...THOUGH ISOLD TORNADOES WILL REMAIN POSSIBLE...MAINLY ACROSS ECNTRL/SERN AR INTO NWRN MS AND WRN TN. THE INCREASING MID-LEVEL FLOW /100+ KTS AT H5/ WILL ENHANCE THE VERTICAL SHEAR...AND IF A SUFFICIENTLY STRONG UPDRAFT CAN EVOLVE...EMBEDDED SUPERCELL STRUCTURES WILL BE POSSIBLE. MORE LIKELY SCENARIO WILL BE FOR BOW ECHO/LEWPS ALONG THE QLCS THAT PRODUCE CORRIDORS OF DAMAGING WINDS. ..RACY.. 11/30/2006  From swody1 at goshenarc.org Sat Nov 4 05:44:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 00:44:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040546 SWODY1 SPC AC 040544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 PM CST FRI NOV 03 2006 VALID 041200Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... EMBEDDED IN A RELATIVELY ZONAL UPPER LEVEL PATTERN ACROSS THE CONUS...A PROGRESSIVE SHORTWAVE TROUGH OVER THE GREAT BASIN EARLY THIS MORNING WILL MOVE EWD INTO THE CENTRAL/SRN PLAINS BY THE TONIGHT. STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THIS SYSTEM COMBINED WITH HEATING AND OROGRAPHIC LIFT MAY SUPPORT A FEW TSTMS OVER PORTIONS OF THE SRN ROCKIES IN THE AFTERNOON. AHEAD OF THIS SYSTEM...MODIFIED RETURN FLOW WILL SUPPORT LOW LEVEL MOISTURE INCREASE OVER THE SRN PLAINS. ALONG WITH LIFT ASSOCIATED WITH THE APPROACHING SYSTEM....THERE WILL BE THE POTENTIAL FOR ELEVATED TSTMS OVERNIGHT ACROSS PORTIONS OF THE AREA. THE REMAINDER OF THE ERN HALF OF THE NATION WILL REMAIN STABLE UNDER THE INFLUENCE OF A BROAD AREA OF SFC HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE OVER THE FLA KEYS WHERE A DIFFUSE FRONTAL BOUNDARY AND A PLUME OF MID/HIGH LEVEL TROPICAL MOISTURE WILL REMAIN INVOF THE AREA...SUPPORTING ISOLATED TSTMS GENERALLY BEFORE 00Z. ...PORTIONS OF OK/WRN AR AND SRN MO... ELEVATED MOISTURE /850 DEWPT AROUND 8 DEG C NOTED ON THE 04/00Z DRT SOUNDING AND 700 DEWPT AROUND 0 DEG C ON THE 04/00Z MAF SOUNDING/ WILL ADVECT/ISENTROPICALLY LIFT INTO THE REGION LATER THIS AFTERNOON AND OVERNIGHT ON THE NOSE OF A MODERATELY STRONG 40 KT LOW LEVEL JET. WITH THE APPROACH OF THE SHORTWAVE...MID LEVEL TEMPERATURES WILL COOL AIDING IN STEEPENING MID LEVEL LAPSE RATES. IN ADDITION...INCREASING MID LEVEL VERTICAL MOTION WILL OCCUR OVER THE AREA OVERNIGHT AS A RESULT THE RIGHT ENTRANCE OF A 100 KT UPPER LEVEL SPEED MAX MOVING ACROSS THE REGION. THE COMBINATION OF ALL THESE INGREDIENTS SHOULD BE SUFFICIENT TO SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS FROM PORTIONS OF CENTRAL/ERN OK INTO SRN MO AND WRN AR GENERALLY AFTER 03Z. MARGINAL INSTABILITY /MUCAPES LESS THAN 250 J/KG/ SHOULD PRECLUDE AN ELEVATED SVR HAIL THREAT. ..CROSBIE/WEISS.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 12:41:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 07:41:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041243 SWODY1 SPC AC 041240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST SAT NOV 04 2006 VALID 041300Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...KS/OK/TX/MO/AR... WATER VAPOR LOOP SHOWS BROAD/FAST ZONAL FLOW PATTERN ACROSS MOST OF THE NATION THIS MORNING. ONE UPPER SHORTWAVE TROUGH CURRENTLY OVER NV/UT WILL TRACK EASTWARD ACROSS THE ROCKIES AND INTO THE CENTRAL HIGH PLAINS BY SUNDAY MORNING. SOUTHWESTERLY LOW LEVEL JET WILL BE SUSTAINED THROUGHOUT THE FORECAST PERIOD FROM CENTRAL TX...ACROSS MO...INTO THE WESTERN GREAT LAKES REGION. TRAJECTORIES WILL DRAW MODEST LOW LEVEL MOISTURE /MOSTLY ELEVATED ABOVE STABLE BOUNDARY LAYER/ INTO PARTS OF OK/KS/MO/AR. MODEL FORECAST SOUNDINGS ACROSS THIS AREA SHOW A PLUME OF MARGINAL ELEVATED INSTABILITY DEVELOPING AFTER 00Z IN REGION OF LOW LEVEL JET AXIS. INCREASING FORCING FOR LARGE SCALE ASCENT DURING THIS PERIOD IS EXPECTED TO RESULT IN AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS FROM NORTH CENTRAL TX INTO SOUTHWEST MO. LACK OF SUFFICIENT INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ...CO... STEEP LOW/MID LEVEL LAPSE RATES ARE FORECAST TO DEVELOP THIS AFTERNOON OVER THE HIGHER TERRAIN OF SOUTHERN CO AS UPPER SHORTWAVE TROUGH APPROACHES AREA. 500MB TEMPERATURES AROUND -18C COUPLED WITH POCKETS OF STRONG DAYTIME HEATING ARE LIKELY TO RESULT IN SUFFICIENT INSTABILITY FOR ISOLATED THUNDERSTORMS. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND DIMINISH RAPIDLY AFTER SUNSET. NO SEVERE STORMS ARE FORECAST. ...SOUTH FL... PLUME OF SUBTROPICAL MOISTURE REMAINS OVER THE FL STRAITS THIS MORNING. THIS WILL LIKELY RESULT IN SCATTERED CONVECTION THROUGHOUT THE DAY ACROSS THE SOUTHERN HALF OF THE FL PENINSULA. FAR SOUTH FL AND THE KEYS MAY SEE SUFFICIENTLY DEEP INSTABILITY FOR ISOLATED LIGHTNING STRIKES IN STRONGER CELLS THIS AFTERNOON. ..HART/CROSBIE.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 16:19:57 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 11:19:57 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041622 SWODY1 SPC AC 041620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST SAT NOV 04 2006 VALID 041630Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS... MID-LEVEL SHORTWAVE TROUGH OVER UT WILL TRACK E/SEWD TOWARDS THE OK/TX PANHANDLES BY SUNDAY MORNING. A 30-40 KT S/SWLY LOW-LEVEL JET WILL BE SUSTAINED AHEAD OF THIS TROUGH FROM CNTRL TX INTO ERN OK. MODEST LOW-LEVEL MOISTURE /AS SAMPLED BY 12Z DRT SOUNDING/ WILL BE DRAWN N/NEWD. IN ADDITION...MID-LEVEL LAPSE RATES AROUND 7 C/KM SHOULD BE ADVECTED EWD ATOP THE LOW-LEVEL MOIST AXIS ACROSS WRN/CNTRL OK AND N-CNTRL TX. MODEL FORECAST SOUNDINGS INDICATE MARGINAL ELEVATED INSTABILITY WITH MUCAPES OF 500 TO 1000 J/KG IN THIS REGION LATER TONIGHT. AS LARGE-SCALE FORCING INCREASES WITH THE SHORTWAVE APPROACHING...ISOLATED TO SCATTERED TSTMS SHOULD DEVELOP...ESPECIALLY BY THE 09-12Z TIME FRAME. A FEW STORMS MAY CONTAIN SOME MARGINAL HAIL. FURTHER E...OTHER TSTMS SHOULD DEVELOP IN THE LOW-LEVEL MOIST AXIS...MAINLY AFTER DARK. ...SRN CO... LOW-LEVEL LAPSE RATES WILL STEEPEN THROUGH THIS AFTERNOON AS DAYTIME HEATING CONTINUES. COOL MID-LEVEL TEMPS /AROUND -18C AT 500 MB/ IN ASSOCIATION WITH THE UT SHORTWAVE SHOULD RESULT IN WEAK INSTABILITY FOR A FEW TSTMS. CONVECTION SHOULD BE DIURNAL IN NATURE AND DIMINISH AFTER SUNSET. ..GRAMS/THOMPSON.. 11/04/2006  From swody1 at goshenarc.org Sat Nov 4 19:54:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 14:54:07 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041956 SWODY1 SPC AC 041953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0153 PM CST SAT NOV 04 2006 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SRN PLAINS INTO OZARK PLATEAU... VISIBLE SATELLITE LOOP AND SURFACE OBSERVATIONAL DATA TRENDS INDICATE LOW-LEVEL MOISTURE INCREASING NWD FROM THE NWRN GULF OF MEXICO INTO NWRN TX...DOWNSTREAM FROM SHORT WAVE TROUGH MOVING INTO THE SRN HIGH PLAINS. THIS SHORTWAVE TROUGH WILL CONTINUE EWD OVERNIGHT...PROMOTING NOCTURNAL LLJ DEVELOPMENT FROM THE LOWER RIO GRANDE VALLEY INTO ERN OK. ELEVATED TSTMS ARE FORECAST TO BECOMING INCREASINGLY LIKELY OVERNIGHT ALONG THIS LLJ AXIS WHERE WAA/ISENTROPIC UPGLIDE WILL BE COLOCATED WITH THE INCREASE IN MOISTURE /MOST NOTABLY IN THE 850-800 MB LAYER/ AND STEEPENING MID-LEVEL LAPSE RATES. SOME SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS...BUT NO SEVERE WEATHER IS ANTICIPATED. ...SWRN TX... VISIBLE SATELLITE AND RUC OBJECTIVE FIELDS INDICATE BOUNDARY LAYER BECOMING PROGRESSIVELY MORE BUOYANT THIS AFTERNOON OWING TO DIABATIC HEATING AND MODEST LOW-LEVEL MOISTURE WITH SBCAPES OF 1000-1500 J/KG AND LITTLE OR NO CONVECTIVE INHIBITION. LARGE SCALE FORCING FOR ASCENT IS EXPECTED TO REMAIN QUITE WEAK...HOWEVER SUBTLE OROGRAPHIC FORCING MAY BE SUFFICIENT TO INITIATE ISOLATED TSTMS THIS AFTERNOON INTO EVENING ALONG THE HIGHER TERRAIN. ..MEAD.. 11/04/2006  From swody1 at goshenarc.org Sun Nov 5 01:01:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 20:01:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050103 SWODY1 SPC AC 050100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0700 PM CST SAT NOV 04 2006 VALID 050100Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... IN MID/UPPER LEVELS...NEARLY ZONAL MEAN FLOW PATTERN IS EVIDENT OVER MOST OF CONUS...DISTORTED PRIMARILY BY SHORTWAVE TROUGH ANALYZED FROM CENTRAL HIGH PLAINS SWWD ACROSS SWRN NM. THIS TROUGH SHOULD DRIFT EWD OVERNIGHT. UPSTREAM...MID-UPPER LEVEL SHORTWAVE TROUGH -- EVIDENT IN MOISTURE CHANNEL IMAGERY FROM 130-133W OFFSHORE WA/BC -- IS FCST TO MOVE INLAND BY APPROXIMATELY 06Z. AT SFC...WEAK QUASISTATIONARY FRONT AND CONFLUENT LINE WAS ANALYZED FROM NW OK SWWD ACROSS CENTRAL TX PANHANDLE...THROUGH LOW INVOF TCC...THEN BECOMING DIFFUSE FARTHER WSW. DRYLINE WAS ANALYZED FROM NRN COAHUILA NWD BETWEEN MAF-INK THEN NNEWD ACROSS CDS AREA...BECOMING DIFFUSE OVER WRN OK WHERE ONLY WEAK MOISTURE HAS RETURNED TO ITS E. LOW CLOUD TRENDS AND GPS-PW DATA INDICATE BOUNDARY LAYER DRYLINE HAS BEEN QUASISTATIONARY SE OF REGION DURING PAST FEW HOURS...HOWEVER MORE INTENSE PRESSURE/HEIGHT FALLS ARE EXPECTED IN LOW LEVELS OVERNIGHT THAT SHOULD SHIFT W/NW EDGE OF MOIST PLUME AT LEAST INTO POSITION OF QUASISTATIONARY FRONT OVER PANHANDLE...AND WWD TO VICINITY NM BORDER AND DAVIS MOUNTAINS FARTHER S. ...OZARKS TO SRN HIGH PLAINS... AHEAD OF AFOREMENTIONED SHORTWAVE TROUGH...ELEVATED LOW LEVEL WAA REGIME WILL PERSIST THROUGH TONIGHT...ACCOMPANIED BY MOISTENING/STRENGTHENING LLJ FROM NRN COAHUILA NWD THEN NEWD ACROSS W-CENTRAL/N-CENTRAL TX AND ERN OK. TWO ASSOCIATED AREAS OF GEN TSTM POTENTIAL EXIST FOR REMAINDER PERIOD...WITH JUST ENOUGH UNCERTAINTY IN POSSIBLE SPATIAL OVERLAP THAT THEY STILL FORM ONE COMPOSITE AREA ON 01Z-12Z GRAPHIC DEPICTION. 1. CONVECTION IS INCREASING IN COVERAGE AND INTENSITY ACROSS SERN KS...NWRN AR...NERN OK AND SWRN MO ATTM. THIS ACTIVITY CORRESPONDS TO LEADING PORTION OF FAVORABLE LOW LEVEL MOIST ADVECTION ABOVE SFC...AND ISENTROPIC ASCENT TO LFC. ELEVATED MUCAPES 100-200 J/KG ALREADY EVIDENT IN SGF RAOB WERE UNDERFCST BY LATEST RUNS OF BOTH ETA AND RUC...INDICATING THESE MODELS MAY SIMILARLY UNDERFCST SIZE/COVERAGE OF CONVECTIVE AREA THIS EVENING UNTIL LATEST RAOB DATA IS INPUT. PRIND ACTIVITY OVER THIS REGION WILL WEAKEN AFTER ABOUT 08Z AS PRIMARY FOCI FOR ELEVATED CONVECTION SHIFT SW. 2. AFTER ABOUT 06Z...WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP OVER PORTIONS NW TX....ERN TX PANHANDLE AND/OR WRN OK. MODIFIED RUC SOUNDINGS SUGGEST SUFFICIENT MOISTENING IN 750-900 MB LAYER -- BENEATH 7-8 DEG C/KM MIDLEVEL LAPSE RATES...FOR ELEVATED MUCAPES TO REACH 800 J/KG BY END OF PERIOD OVER SWRN OK AND NW TX...WITH MINIMAL CINH. ADDITIONAL/CONDITIONAL THUNDER AREA MAY DEVELOP BENEATH OR JUST W OF LLJ AXIS FROM CENTRAL TX NNEWD ACROSS CENTRAL OK...AMIDST STRONGEST LOW LEVEL MOISTURE TRANSPORT. ...WRN/NRN OLYMPIC PENINSULA... STRONGEST MID-UPPER LEVEL ASCENT WITH MIDLEVEL TROUGH SHOULD REMAIN JUST N OF AREA ACROSS VANCOUVER ISLAND. GIVEN WEAKLY BUOYANT PROFILE EVIDENT IN UIL RAOB...BRIEF/ISOLATED LIGHTNING CANNOT BE RULED OUT...HOWEVER POTENTIAL APPEARS TOO TRANSIENT AND CONDITIONAL TO WARRANT GEN THUNDER OUTLOOK. ..EDWARDS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 04:12:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 04 Nov 2006 23:12:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050414 SWODY1 SPC AC 050412 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1012 PM CST SAT NOV 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MIDDLE/UPPER LEVEL PATTERN WILL REMAIN GENERALLY ZONAL....EXCEPT FOR TROUGHING ACROSS CENTRAL CONUS. MAIN SHORTWAVE FEATURE WILL BE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM CENTRAL HIGH PLAINS TO SRN NM. THIS FEATURE IS EXPECTED TO MOVE SEWD AND AMPLIFY SOMEWHAT...EXTENDING FROM MO SWWD ACROSS CENTRAL TX TO N-CENTRAL MEX BY 06/12Z. AT SFC...WEAK FRONTAL ZONE AND TROUGH -- NOW EVIDENT OVER SRN TX PANHANDLE AND NWRN OK -- IS EXPECTED TO SHIFT SEWD ACROSS NW AND W-CENTRAL TX AHEAD OF SLOWLY DIGGING MIDLEVEL SYSTEM. WEAK SFC LOW NOW EVIDENT SW TCC MAY PROPAGATE SEWD ALONG THIS BOUNDARY. ...W-CENTRAL/SW TX... EXTENSIVE SW-NE PLUME OF CLOUDS/PRECIP -- WITH EMBEDDED AND LARGELY ELEVATED TSTMS -- IS EXPECTED TO DEVELOP FROM CENTRAL/N-CENTRAL TX NEWD ACROSS SERN OK INTO AR THROUGH MUCH OF PERIOD. THIS WILL LIMIT DESTABILIZATION...BOTH SFC AND ALOFT OVER MUCH OF SERN PLAINS...RED RIVER REGION AND ARKLATEX. HOWEVER...SFC HEATING MAY BE MORE PRONOUNCED DURING AFTERNOON ACROSS BIG COUNTRY...CONCHO VALLEY...LOWER PECOS RIVER AND ERN PERMIAN BASIN REGIONS OF TX. TSTMS MAY DEVELOP ALONG AND S OF BOUNDARY DURING AFTERNOON AND EVENING...SHIFTING EWD-SEWD TOWARD HILL COUNTRY WITH POTENTIAL FOR ISOLATED HAIL AND DAMAGING GUSTS. SFC MOISTURE S OF BOUNDARY IS EXPECTED TO RECOVER GRADUALLY ACROSS THIS REGION...AS SELY FLOW CONTINUES FROM MODIFYING NWRN-GULF AIR MASS. SFC DEW POINTS OVER MUCH OF REGION SHOULD REACH 60S BY AFTERNOON...BENEATH MODEST 6.5-7.5 DEG C/KM MIDLEVEL LAPSE RATES. ACCORDINGLY MODIFIED WRF SOUNDINGS SUGGEST MLCAPES 500-1000 J/KG OVER REGION. OTHER THAN HEATING ITSELF...LIFT MAY BE LIMITED. WEAK BOUNDARY LAYER WINDS ARE FCST...WHICH WILL LIMIT BOTH LOW LEVEL SHEAR AND CONVERGENCE INVOF FRONT/TROUGH. FLOW IS EXPECTED TO VEER WITH HEIGHT...BUT DEEP-LAYER SHEAR WILL BE MRGL OVER MOST OF REGION. SOME ENHANCEMENT TO LIFT AND SHEAR MAY OCCUR IF DIFFERENTIAL HEATING CAN DIURNALLY REINFORCE PREVIOUSLY WEAK BAROCLINIC GRADIENT ASSOCIATED WITH SFC BOUNDARY...HOWEVER ASSOCIATED MESOSCALE PROCESSES ARE TOO CONDITIONAL TO JUSTIFY GREATER PROBABILITY NUMBERS ATTM. ..EDWARDS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 12:31:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 07:31:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051233 SWODY1 SPC AC 051231 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 AM CST SUN NOV 05 2006 VALID 051300Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...OK SWD INTO CNTRL/SW TX... A SHORTWAVE TROUGH OVER THE TX PNHDL AT SUNRISE WILL TRANSLATE EWD ACROSS OK AND N TX THIS AFTN TO SRN MO/AR BY 12Z. A SECONDARY IMPULSE...NOW OVER AZ...WILL DIG SEWD INTO SW TX BY LATE EVE...REACHING SCNTRL TX BY EARLY MON MORNING. IN THE LWR LEVELS...A FRONT/TROUGH OVER THE SRN HIGH PLAINS WILL MOVE SEWD ACROSS NW AND WCNTRL TX IN WAKE OF THE LEAD IMPULSE. AT DAYBREAK...LOW-LEVEL MOISTURE/EXTENSIVE CLOUDS CONTINUED TO SPREAD NWWD ACROSS THE SRN PLAINS IN ADVANCE OF THE UPPER TROUGH. THE INITIAL WARM CONVEYOR BELT ENHANCED CONVECTION PERSISTED IN AN ARC FROM N TX TO THE OZARKS. ADDITIONAL TSTMS WERE DEVELOPING ACROSS WRN/CNTRL OK TIED TO THE STRONGEST H5-H3 Q-VECTOR CONVERGENCE ASSOCD WITH THE MID-LEVEL IMPULSE. AS THE LEAD IMPULSE MOVES ACROSS OK/N TX THROUGH THIS AFTN... CONVECTION/TSTMS WILL INCREASE ALONG WRN EDGE OF THE ORIGINAL WARM CONVEYOR FROM CNTRL/SERN OK SWD INTO N TX. AS A RESULT...BOUNDARY LAYER HEATING WILL BE MINIMAL AND SFC BASED TSTMS ARE NOT EXPECTED. NONETHELESS...MID-LEVEL COLD ADVECTION/STEEPENING LAPSE RATES ALOFT WILL TEND TO SUPPORT STRONGER ELEVATED TSTMS THAT MAY PRODUCE ISOLD LARGE HAIL. FARTHER S...SOUNDINGS INDICATE THAT SFC HEATING MAY BE MORE PRONOUNCED THIS AFTN ACROSS THE BIG COUNTRY...CONCHO VALLEY...LOWER PECOS RIVER AND ERN PERMIAN BASIN REGIONS OF TX. BOUNDARY LAYER MOISTURE SHOULD BE MAINTAINED DURING PEAK HEATING BENEATH MID-LEVEL LAPSE RATES AROUND 7 DEG C/KM...RESULTING IN MLCAPES TO 1000 J/KG. OVERALL FORCING FOR ASCENT WILL BE COMPARATIVELY WEAKER HERE THAN FARTHER N...UNTIL LATER TONIGHT WHEN THE SECONDARY AZ IMPULSE APPROACHES THE REGION. MOREOVER... VERTICAL WIND SHEAR WILL BE MARGINAL OVER MOST OF THE REGION...GENERALLY AOB 35 KTS. TSTMS MAY DEVELOP ALONG AND S OF THE SFC TROUGH DURING PEAK HEATING...PRIMARILY ACROSS THE LOW ROLLING PLAINS/BIG COUNTRY. TSTMS WILL BECOME MORE LIKELY AFTER DARK FARTHER S IN SWRN/WCNTRL TX IN ASSOCIATION WITH THE AZ IMPULSE. THIS ACTIVITY WILL THEN SHIFT E-SEWD TOWARD THE HILL COUNTRY OVERNIGHT WITH THE POTENTIAL FOR ISOLD LARGE HAIL AND DAMAGING WIND GUSTS. ATTM...ANTICIPATED ISOLD SEVERE THREATS PRECLUDE A CATEGORICAL SLGT RISK. FINALLY...TSTMS MAY DEVELOP FARTHER DOWNSTREAM ALONG THE SERN TX COAST BETWEEN 09-12Z. ATTM...IT APPEARS THE STRONGER STORMS SHOULD REMAIN OFFSHORE WHERE STRONGER INSTABILITY WILL EXIST. ..RACY/CROSBIE.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 16:02:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 11:02:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051604 SWODY1 SPC AC 051602 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1002 AM CST SUN NOV 05 2006 VALID 051630Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...W-CENTRAL INTO NWRN TX... PAIR OF MID LEVEL IMPULSES WILL IMPACT THE SRN PLAINS TODAY AND TONIGHT. LEADING SYSTEM IS FOCUSING AN AREA OF THUNDERSTORMS INTO CENTRAL OK THIS MORNING...WITH WEAK LOW LEVEL WAA ALONG ASSOCIATED 20 KT H85 JET SUSTAINING A FEW ELEVATED THUNDERSTORMS INTO ERN OK/WRN AR. THIS ACTIVITY WILL LIKELY WEAKEN AS LEADING SYSTEM DAMPENS OUT AND EJECTS EWD TODAY. TRAILING SHORTWAVE TROUGH IS NOW DIGGING SEWD INTO CENTRAL/SRN NM. LOW LEVEL WINDS WILL LIKELY BACK AND SLIGHTLY STRENGTHEN THIS AFTERNOON INTO CENTRAL/WRN TX IN RESPONSE TO HEIGHT FALLS AHEAD OF THIS SYSTEM. LOW CLOUDS AND LIMITED SURFACE MOISTURE WILL HINDER DESTABILIZATION...THOUGH INCREASING LARGE SCALE ASCENT AND MODEST INSTABILITY WILL SUPPORT A CLUSTER OF THUNDERSTORMS LATER THIS AFTERNOON OVER WRN/NWRN TX WHICH SHOULD DEVELOP INTO A MCS AND SPREAD ESEWD ACROSS MORE OF NRN/CENTRAL TX THIS EVENING AND INTO ERN TX OVERNIGHT. INITIAL DEVELOPMENT MAY BECOME ROOTED INTO THE BOUNDARY LAYER ACROSS NWRN TX WHERE BREAKS IN LOW CLOUDS ARE EVIDENT THIS MORNING. HOWEVER...MOST OF THE ACTIVITY WILL LIKELY REMAIN OR BECOME INCREASINGLY ELEVATED THIS EVENING AND TONIGHT. OVERALL SETUP APPEARS MARGINAL FOR MORE THAN AN ISOLATED SEVERE THUNDERSTORM...THOUGH ONE OR TWO STRONGER STORMS LATE TODAY MAY PRODUCE HAIL/WIND AROUND SEVERE LEVELS. ..EVANS/GRAMS.. 11/05/2006  From swody1 at goshenarc.org Sun Nov 5 19:47:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 14:47:51 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051950 SWODY1 SPC AC 051947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST SUN NOV 05 2006 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER SWRN OK INTO NWRN TX... ...OK/TX... AFTERNOON WATER VAPOR IMAGERY SHOWS VORTICITY MAXIMA OVER THE TX PNHDL AND S-CNTRL NM WITH LATEST MODEL GUIDANCE CONSISTENT IN SHIFTING THESE FEATURES SEWD THROUGH WRN INTO CNTRL TX TONIGHT. IN THE LOW-LEVELS...18Z MESOANALYSIS INDICATED LOW PRESSURE N OF MAF WITH INVERTED TROUGH/BAROCLINIC ZONE EXTENDING NEWD THROUGH E-CNTRL TX PNHDL INTO NERN OK. THE TRAILING PORTION OF THIS BOUNDARY THEN EXTENDED SWD INTO SWRN TX /E OF FST/. FINALLY...WARM FRONT STRETCHED FROM INTERSECTION WITH INVERTED TROUGH OVER THE SERN TX PNHDL OR SWRN OK ESEWD THROUGH S-CNTRL OK INTO NERN TX. THIS INVERTED TROUGH IS FORECAST TO TRANSITION TO MORE OF A COLD FRONT AS IT PUSHES SEWD INTO NWRN TX...WITH ASSOCIATED TRIPLE POINT LOW DEVELOPING SEWD INTO NWRN AND EVENTUALLY CNTRL TX OVERNIGHT. THUS FAR TODAY....TSTMS HAVE BEEN FOCUSED NEAR INVERTED TROUGH-850 MB FRONTAL ZONE FROM THE E-CNTRL TX PNHDL INTO WRN OK WITHIN A PLUME OF 7-7.5 C/KM MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF AROUND 500 J/KG. MORE RECENT DEVELOPMENT HAS OCCURRED NEAR WARM FRONT/INVERTED TROUGH TRIPLE POINT /NEAR CDS/ WITHIN ZONE OF STRONGER DEEP-LAYER FORCING FOR ASCENT ASSOCIATED WITH LEAD SHORT WAVE TROUGH. WIDESPREAD CLOUDS AND WEAKER MID-LEVEL LAPSE RATES WITH SWD EXTENT HAVE LIMITED AIR MASS DESTABILIZATION TODAY ACROSS MUCH OF WARM SECTOR WITH MLCAPES OF LESS THAN 1000 J/KG. A FEW BREAKS IN THE CLOUDS HAVE ALLOWED TEMPERATURES TO WARM INTO THE LOWER 70S ALONG THE RED RIVER /NEAR SPS/ AND WHEN COUPLED WITH DEWPOINTS OF AROUND 60F ARE LIKELY CONTRIBUTING TO LOCALLY STRONGER INSTABILITY. SHORT TERM RUC/OPERATIONAL WRF AND HIGH RESOLUTION WRF DATASETS SUGGEST THAT DEEP CONVECTION WILL BECOME INCREASINGLY FOCUSED THIS AFTERNOON INTO EVENING OVER NWRN TX AS THE STRONGER FORCING FOR ASCENT OVERSPREADS SLIGHTLY TO MODERATELY UNSTABLE WARM SECTOR. WHILE REGIONAL VWPS/PROFILERS INDICATE THAT VERTICAL SHEAR IS MARGINALLY STRONG /30-35 KT EFFECTIVE BULK SHEAR/ GIVEN THE DEGREE OF BUOYANCY...SOME POTENTIAL WILL EXIST FOR ROTATING STORMS CAPABLE OF SEVERE HAIL. STORMS SHOULD INCREASE IN AREAL COVERAGE OVERNIGHT OVER NRN INTO CNTRL TX AS AFOREMENTIONED SHORT WAVE TROUGHS PHASE AND CONTRIBUTE TO OVERALL AMPLIFICATION OF UPPER SYSTEM. HOWEVER...IT APPEARS THAT BOTH VERTICAL SHEAR AND INSTABILITY WILL REMAIN MARGINAL WITH ONLY A THREAT OF ISOLATED SEVERE STORMS CAPABLE OF SOME WIND/HAIL. ..MEAD.. 11/05/2006  From swody1 at goshenarc.org Mon Nov 6 00:55:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 05 Nov 2006 19:55:38 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060057 SWODY1 SPC AC 060055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0655 PM CST SUN NOV 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS FAR S CENTRAL OK/CENTRAL N TX... ...N TX INTO S CENTRAL AND SERN OK... MCS IS ONGOING ATTM OVER N CENTRAL TX/S CENTRAL OK...ALONG WARM FRONT WHICH EXTENDS W-E ACROSS N TX JUST S OF THE RED RIVER. OVERALL DEGREE OF INSTABILITY AND SHEAR REMAINS MARGINAL /EVENING FORT WORTH RAOB REVEALS LESS THAN 500 J/KG MEAN-LAYER CAPE AND SHEAR OVER THE LOWER HALF OF THE STORM DEPTH 33 KT/. HOWEVER...A MESO-LOW HAS EVOLVED WITHIN A SMALL/FAIRLY INTENSE STORM CLUSTER ALONG THE WARM FRONT...AND A BOWING LINE SEGMENT CONTINUES TO ORGANIZE S OF THE MESO-LOW NOW MOVING EWD AT 35 KT. THEREFORE...WILL MAINTAIN A SMALL SLIGHT RISK AREA ALONG AND S OF THE RED RIVER...MAINLY ACROSS PARTS OF N TX. ELSEWHERE...A MORE LIMITED SEVERE POTENTIAL EXTENDS WWD INTO WRN N TX...WHERE SHEAR AND INSTABILITY REMAIN MARGINALLY-SUPPORTIVE OF SEVERE STORMS BUT WHERE CONVECTIVE DEVELOPMENT REMAINS LIMITED -- PRESUMABLY DUE TO LOW-LEVEL CAPPING. A LIMITED THREAT FOR MARGINAL HAIL ALSO APPEARS TO EXTEND INTO SERN OK AND NERN TX. OVERALL SEVERE THREAT ACROSS THE SRN PLAINS SHOULD CONTINUE FOR THE NEXT COUPLE OF HOURS...AND THEN BEGIN TO SLOWLY DIMINISH AS BOUNDARY LAYER STABILIZES AND STORMS MOVE INTO EVEN LESS-UNSTABLE AIRMASS OVER NERN TX/SERN OK. ..GOSS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 05:25:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 00:25:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060527 SWODY1 SPC AC 060525 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 PM CST SUN NOV 05 2006 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH IS FORECAST TO STRENGTHEN/SHIFT SLOWLY EWD ACROSS THE S CENTRAL CONUS THIS PERIOD...AS VORT MAX/DEVELOPING UPPER LOW DIGS QUICKLY SSEWD FROM THE CENTRAL/NRN HIGH PLAINS TOWARD THE LOWER MS VALLEY THROUGH THE END OF THE PERIOD. WIDESPREAD CONVECTIVE PRECIPITATION IS FORECAST ACROSS THE S CENTRAL CONUS AHEAD OF THIS FEATURE AND ASSOCIATED WEAK SURFACE LOW/TROUGH MOVING OUT OF E TX AND ACROSS THE LOWER MS VALLEY THROUGH 07/12Z. ...WRN AND CENTRAL GULF COAST REGION... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE S CENTRAL CONUS...WITH ALL MODELS FORECASTING A SIGNIFICANT INCREASE IN CONVECTIVE COVERAGE WITH TIME ACROSS THE LOWER MS VALLEY REGION AND VICINITY. WITH CLOUDS/PRECIPITATION AND ASSOCIATED WEAK LAPSE RATES FORECAST TO LIMIT ANY POTENTIAL FOR DESTABILIZATION...EXPECT SEVERE THREAT TO REMAIN LOW ACROSS MOST PARTS OF THE REGION. MODELS HINT THAT WARM FRONT -- AT THE LEADING EDGE OF RICHER GULF MOISTURE -- MAY ATTEMPT TO WORK NWD/ONSHORE ACROSS SRN LA/SRN MS DURING THE DAY. SHOULD THIS OCCUR...FAVORABLE LOW-LEVEL VEERING/SHEAR INVOF BOUNDARY AND SLIGHTLY GREATER INSTABILITY -- DRIVEN BY TROPICAL BOUNDARY LAYER -- WOULD SUPPORT A POTENTIAL FOR LOW-LEVEL ROTATION AND POSSIBLY A LIMITED TORNADO THREAT. ATTM...CONFIDENCE THAT MOIST/SUFFICIENTLY-UNSTABLE AIRMASS WILL WORK INLAND REMAINS LOW...AND THUS WILL MAINTAIN ONLY A LOW-PROBABILITY SEVERE THREAT ACROSS THIS REGION. SLIGHT RISK MAY BE WARRANTED IN LATER OUTLOOKS IF IT APPEARS THAT SUFFICIENT MOISTENING/DESTABILIZATION MAY OCCUR ONSHORE. ...PARTS OF OK AND TX... AS COLD /AROUND -20 C AT H5/ MID-LEVEL AIR SPREADS SSEWD ACROSS OK AND PARTS OF TX NEAR PEAK HEATING -- IN CONJUNCTION WITH UPPER VORT MAX/LOW...MARGINAL DESTABILIZATION IS EXPECTED. DEGREE OF INSTABILITY AND LARGE-SCALE ASCENT AHEAD OF APPROACHING UPPER FEATURE MAY SUPPORT THE EVENTUAL DEVELOPMENT OF SCATTERED TO ISOLATED/LOW-TOPPED CONVECTION. GIVEN COLD MID-LEVEL AIR/STEEP LAPSE RATES...SMALL TO MARGINALLY-SEVERE HAIL MAY BE POSSIBLE WITH ANY STRONGER UPDRAFTS. THREAT SHOULD END QUICKLY THROUGH SUNSET WITH THE LOSS OF DAYTIME HEATING. ..GOSS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 12:55:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 07:55:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061256 SWODY1 SPC AC 061254 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 AM CST MON NOV 06 2006 VALID 061300Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WATER VAPOR IMAGERY THIS MORNING SHOWS VERY STRONG ZONAL FLOW AT MID/UPPER LEVELS INTO THE PACIFIC NORTHWEST WITH RIDGING FROM CENTRAL CA NEWD INTO MT. THIS IS RESULTING IN A RAPIDLY DEEPENING TROUGH DIVING SWD THROUGH WRN KS AT THIS TIME WHICH IS EXPECTED TO BECOME A MID/UPPER LEVEL LOW OVER OK BY THIS AFTERNOON AND MOVE INTO THE LOWER MS VALLEY TONIGHT. SURFACE FEATURES SEEM TO BE WEAK ACROSS THE SRN PLAINS DOMINATED MORE BY CONVECTIVE OUTFLOW ASSOCIATED WITH LINE OF STORMS FROM E CENTRAL AND SERN AR SWWD INTO W CENTRAL LA...THEN WWD ACROSS NRN TX. S OF THIS BOUNDARY IS A POOL OF MODERATELY UNSTABLE AIR WHERE MLCAPE RANGES FROM 1000 J/KG OVER PARTS OF SERN TX TO 2000 J/KG OVER WRN SECTIONS IN THE MIDDLE RIO GRANDE VALLEY. IN THE PAST FEW HOURS...SOME STRONG/ISOLATED SEVERE STORMS HAVE BEEN OCCURRING FROM W OF LFK TO AROUND SAT AHEAD OF WEAK MID LEVEL TROUGH THAT EXTENDS FROM ERN OK SWWD INTO THE MIDDLE RIO GRANDE. ...PARTS OF SERN TX INTO SRN LA... TWO FACETS TO CONSIDER HERE IS THAT AS THE MID/UPPER LOW DIVES SWD THROUGH TONIGHT...THE SRN BRANCH OF THE UPPER LEVEL JET EXTENDS FROM EXTREME S TX NEWD INTO SRN MS/AL TAKING FAVORABLE EXIT REGION QUADRANT ACROSS SERN TX INTO CENTRAL LA MAINLY TONIGHT. SRN PARTS OF MAIN LOW LEVEL JET PULLS OUT OF SERN MS THRU MID TN TONIGHT CREATING A FAVORABLE AREA OF DEEP LAYER SHEAR FROM THE SERN TX AND LA GULF COAST REGION INTO CENTRAL LA. THUS...GIVEN FAVORABLE KINEMATICS DURING A CLIMATOLOGICAL FAVORABLE TIME PERIOD ACROSS THIS REGION...HAVE KEPT LOW TORNADO PROBABILITIES ACROSS THIS REGION FOR TONIGHT. BUT...ALSO GIVEN THAT ISOLATED SUPERCELLS ARE OCCURRING THIS MORNING WITH CURRENT THERMODYNAMIC PROFILES...EXTENDED THE AREA WWD AS FIRST TROUGH MOVES THROUGH REGION EARLY TODAY. ...PARTS OF WESTERN OK INTO N CENTRAL TX... MID/UPPER LEVEL JET ON BACKSIDE OF RAPIDLY DEEPENING LOW WILL TRAVEL FROM SWRN KS INTO CENTRAL TX THROUGH EARLY TONIGHT. MORNING RAOB DATA FROM DDC SHOWS -20C AT 500 MB AND STEEP LOW-MID LEVEL LAPSE RATES VERY NEAR 8C/KM. THUS...AS TEMPERATURES REACH MID 60S TO 70 DEG F...POTENTIAL INSTABILITY COULD BE AROUND 1000 J/KG LEADING TO THE POSSIBILITY OF ISOLATED STRONG/SEVERE THUNDERSTORMS WITH LARGE HAIL BEING THE MAIN THREAT LATE THIS AFTERNOON AND EARLY TONIGHT. ..MCCARTHY/CROSBIE.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 16:19:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 11:19:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061621 SWODY1 SPC AC 061619 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1019 AM CST MON NOV 06 2006 VALID 061630Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH OVER THE CENTRAL/SRN PLAINS IS FORECAST TO DEEPEN TO A CLOSED LOW OVER THE LOWER MS VALLEY...IN RESPONSE TO A JET MAX AND THERMAL TROUGH DIGGING SEWD DOWN THE BACKSIDE OF THE SYSTEM. A REFLECTION OF THE UPPER TROUGH WAS NOTED AT THE SURFACE WITH A WEAK LOW OVER CENTRAL AR AND A TROUGH/COLD FRONT EXTENDING SWWD FROM THE LOW INTO NERN AND SRN TX. THE WEAK LOW SHOULD MOVE EWD INTO WRN TN TONIGHT WITH THE TRAILING TROUGH/FRONT PUSHING ACROSS THE LOWER MS VALLEY. ...SERN TX EWD INTO SWRN AL INTO SRN LA... LEADING EDGE OF LARGE PRECIPITATION AREA EXTENDED FROM WRN TN/WRN MS SWWD INTO SRN LA/SERN TX AT MID MORNING. PRESENCE OF COLD POOL AND EWD MOVING UPPER TROUGH SHOULD RESULT IN PRECIPITATION SPREADING EWD ACROSS THE REMAINDER OF TN/MS...AND SEWD ACROSS SRN LA AND SERN TX. WIDESPREAD CLOUDS AND WEAK LAPSE RATES WILL RESULT IN ONLY MARGINAL INSTABILITY. WITH THE STRONGEST MASS CONVERGENCE/LIFT EXPECTED TO BE LOCATED ACROSS PORTIONS OF THE TN VALLEY...THREAT FOR SEVERE APPEARS LOW. THOUGH INSTABILITY WILL BE A LITTLE GREATER IN AN AREA BOUNDED BY VCT-CRP-AUS THIS AFTERNOON ...SUBSIDENCE FROM THE RIGHT EXIT REGION OF APPROACHING UPPER JET WILL STRENGTHEN CAPPING THROUGHOUT THE DAY AND REDUCE CONVECTIVE THREAT. ...CENTRAL/WRN OK SWD INTO NRN TX... THERMAL TROUGH ALOFT...WITH 500MB TEMPERATURES NEAR -20C...WILL CREATE A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR A FEW THUNDERSTORMS TO DEVELOP THIS AFTERNOON...ONCE CLOUDS DECREASE AND TEMPERATURES WARM AT LEAST INTO THE LOWER 60S. CLOUDS HAVE CLEARED ACROSS EXTREME NWRN OK AND SHOULD DECREASE ACROSS THE WRN HALF OF OK/NWRN TX BY LATE AFTERNOON. GIVEN THE EXPECTED STEEP MID LEVEL LAPSE RATES...NEAR 8C/KM...AND MUCAPES UP TO 1000 J/KG...ISOLATED THUNDERSTORMS WITH MARGINALLY SEVERE HAIL WOULD BE POSSIBLE. ..IMY/GRAMS.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 20:04:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 15:04:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062001 SWODY1 SPC AC 061958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON NOV 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WRN/CNTRL GULF COAST... LONG-LIVED EXPANSIVE MCS CONTINUES ITS EWD PROGRESSION ACROSS THE LOWER MS VALLEY REGION THIS AFTERNOON. NRN MOST PORTIONS OF THIS ACTIVITY ARE WELL CORRELATED WITH AN UPPER VORT OVER SERN MO...WHILE TRAILING PORTIONS ACROSS MS INTO SERN LA SEEM TO BE DRIVEN IN LARGE PART DUE TO SIGNIFICANT COLD POOL DEVELOPMENT BENEATH PRECIPITATION SHIELD OVER LA/WRN MS. ADDITIONALLY...STRENGTHENING LOW LEVEL WARM ADVECTION APPEARS TO BE DRIVING NUMEROUS SHOWERS OVER THE MS DELTA REGION...SOME OF WHICH ARE NOW DEEP ENOUGH FOR SOME LIGHTNING. WEAK LAPSE RATE ENVIRONMENT WILL LIMIT UPDRAFT STRENGTH ACROSS THIS REGION...ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS DEEPER ROTATION. GREATEST THREAT WITH THIS ACTIVITY SHOULD BE GUSTY WINDS...OR PERHAPS ONE OR TWO WEAK TORNADOES. UPSTREAM ACROSS THE COASTAL PLAINS OF TX...FLOW HAS VEERED SUBSTANTIALLY IN THE WAKE OF EARLY MORNING MCS WITH DEEP WNWLY FLOW NOW OBSERVED ACROSS THE UPPER TX COAST INTO CNTRL TX. LATEST DIAGNOSTIC DATA SUGGEST LOW LEVEL LAPSE RATES HAVE STEEPENED AS BOUNDARY LAYER HAS WARMED...HOWEVER SWWD PROGRESSION OF MULTI-FACETED CONVECTIVE OUTFLOW DOES NOT APPEAR PARTICULARLY FAVORABLE FOR SUSTAINING LONG-LIVED SEVERE UPDRAFTS. AT THIS TIME IT APPEARS ONGOING THUNDERSTORM ACTIVITY ALONG ADVANCING WIND SHIFT...INVOF BASTROP COUNTY...SHOULD CONTINUE SEWD INTO INCREASINGLY HOSTILE AIRMASS. IN ALL LIKELIHOOD THIS SHOULD LIMIT SEVERE POTENTIAL TO MARGINALLY SEVERE HAIL AS UPDRAFTS STRUGGLE TO SUSTAIN THEMSELVES WITH WEAK LOW LEVEL CONVERGENCE. ..DARROW.. 11/06/2006  From swody1 at goshenarc.org Mon Nov 6 21:39:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 16:39:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 062141 SWODY1 SPC AC 062138 DAY 1 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0338 PM CST MON NOV 06 2006 VALID 062000Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WRN/CNTRL GULF COAST... LONG-LIVED EXPANSIVE MCS CONTINUES ITS EWD PROGRESSION ACROSS THE LOWER MS VALLEY REGION THIS AFTERNOON. NRN MOST PORTIONS OF THIS ACTIVITY ARE WELL CORRELATED WITH AN UPPER VORT OVER SERN MO...WHILE TRAILING PORTIONS ACROSS MS INTO SERN LA SEEM TO BE DRIVEN IN LARGE PART DUE TO SIGNIFICANT COLD POOL DEVELOPMENT BENEATH PRECIPITATION SHIELD OVER LA/WRN MS. ADDITIONALLY...STRENGTHENING LOW LEVEL WARM ADVECTION APPEARS TO BE DRIVING NUMEROUS SHOWERS OVER THE MS DELTA REGION...SOME OF WHICH ARE NOW DEEP ENOUGH FOR SOME LIGHTNING. WEAK LAPSE RATE ENVIRONMENT WILL LIMIT UPDRAFT STRENGTH ACROSS THIS REGION...ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS DEEPER ROTATION. GREATEST THREAT WITH THIS ACTIVITY SHOULD BE GUSTY WINDS...OR PERHAPS ONE OR TWO WEAK TORNADOES. UPSTREAM ACROSS THE COASTAL PLAINS OF TX...FLOW HAS VEERED SUBSTANTIALLY IN THE WAKE OF EARLY MORNING MCS WITH DEEP WNWLY FLOW NOW OBSERVED ACROSS THE UPPER TX COAST INTO CNTRL TX. LATEST DIAGNOSTIC DATA SUGGEST LOW LEVEL LAPSE RATES HAVE STEEPENED AS BOUNDARY LAYER HAS WARMED...HOWEVER SWWD PROGRESSION OF MULTI-FACETED CONVECTIVE OUTFLOW DOES NOT APPEAR PARTICULARLY FAVORABLE FOR SUSTAINING LONG-LIVED SEVERE UPDRAFTS. AT THIS TIME IT APPEARS ONGOING THUNDERSTORM ACTIVITY ALONG ADVANCING WIND SHIFT...INVOF BASTROP COUNTY...SHOULD CONTINUE SEWD INTO INCREASINGLY HOSTILE AIRMASS. IN ALL LIKELIHOOD THIS SHOULD LIMIT SEVERE POTENTIAL TO MARGINALLY SEVERE HAIL AS UPDRAFTS STRUGGLE TO SUSTAIN THEMSELVES WITH WEAK LOW LEVEL CONVERGENCE. ..DARROW.. 11/06/2006  From swody1 at goshenarc.org Tue Nov 7 00:54:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 06 Nov 2006 19:54:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070056 SWODY1 SPC AC 070054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST MON NOV 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SRN AL AND PORTIONS OF THE FL PANHANDLE... NE-SW BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS CONTINUES MOVING EWD ACROSS THE CENTRAL GULF COAST REGION...INTO AN ENVIRONMENT OF VERY WEAK INSTABILITY WHICH DECREASES FURTHER WITH EWD EXTENT. LOW-LEVEL SHEAR DOWNSTREAM OF ONGOING CONVECTION REMAINS SUPPORTIVE OF LOW-LEVEL UPDRAFT ROTATION...AND SOME HINTS OF WEAK CIRCULATION CONTINUE TO BE REVEALED BY AREA WSR-88DS -- THOUGH PRIMARILY OFFSHORE. AS STORMS MOVE EWD INTO EVEN LESS FAVORABLE THERMODYNAMIC ENVIRONMENT...ONSHORE SEVERE THREAT WILL CONTINUE TO DIMINISH. HOWEVER...WILL MAINTAIN LOW SEVERE PROBABILITY ATTM ACROSS COASTAL PORTIONS OF SRN AL AND THE FL PANHANDLE FOR THE NEXT FEW HOURS. ..GOSS.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 05:46:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 00:46:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070548 SWODY1 SPC AC 070546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST MON NOV 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH IS FORECAST TO MOVE EWD ACROSS THE SERN U.S. THIS PERIOD. MEANWHILE...FAST/ZONAL FLOW WILL SPREAD ACROSS THE NWRN AND INTO THE N CENTRAL CONUS N OF LOW-AMPLITUDE RIDGE OVER THE SWRN QUARTER OF THE COUNTRY. AT THE SURFACE...A WEAK LOW AND ASSOCIATED COLD FRONT ASSOCIATED WITH THE UPPER TROUGH WILL ALSO SHIFT EWD ACROSS AL/GA/FL THROUGH THE END OF THE PERIOD. ...FL NWD ALONG THE IMMEDIATE ATLANTIC COAST... SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO BE ONGOING ACROSS THE SOUTHEAST AT THE START OF THE PERIOD...AHEAD OF LARGE UPPER TROUGH. WITH WIDESPREAD CLOUDS AND PRECIPITATION ACROSS THIS REGION...POTENTIAL FOR DESTABILIZATION APPEARS TO BE QUITE LIMITED. THEREFORE...DESPITE MODERATELY-STRONG DEEP-LAYER FLOW ACROSS THE SOUTHEAST...SEVERE THREAT APPEARS TO BE LOW ATTM. WILL MAINTAIN LOW PROBABILITY THREAT ACROSS FL...AS COLD FRONT IS FORECAST TO MOVE EWD/SEWD ACROSS THE FL PENINSULA THROUGH THE PERIOD. WILL ALSO MAINTAIN A LOW-PROBABILITY THREAT ALONG THE IMMEDIATE COASTS OF SERN GA AND THE CAROLINAS...TO ACCOUNT FOR THE POSSIBILITY THAT HIGHER THETA-E GULF STREAM AIRMASS NEAR THE COAST MAY SUPPORT STORM DEVELOPMENT INVOF FRONT AS IT APPROACHES LATE IN THE PERIOD. ATTM HOWEVER...IT APPEARS THAT MOST IF NOT ALL SURFACE-BASED STORM DEVELOPMENT SHOULD REMAIN OFFSHORE. ..GOSS.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 12:38:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 07:38:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071240 SWODY1 SPC AC 071238 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0638 AM CST TUE NOV 07 2006 VALID 071300Z - 081200Z ...NO SVR TSTM AREAS FORECAST... MORNING SATELLITE LOOPS SHOW VIGOROUS UPPER TROUGH DIGGING ACROSS THE LOWER MS VALLEY. A LEAD SHORTWAVE TROUGH IS NOTED OVER GA/AL...ACCOMPANYING A LINE OF SHOWERS AND THUNDERSTORMS. THE PRIMARY SURFACE LOW IS CURRENTLY OVER WESTERN TN...BUT CYCLOGENESIS IS EXPECTED TO SHIFT RAPIDLY EASTWARD TO THE CAROLINA COAST BY AFTERNOON. LARGE SCALE FORCING FOR ASCENT WILL BE IN PLACE THROUGHOUT THE SOUTHEAST STATES TODAY...YIELDING A CONTINUATION OF SCATTERED SHOWERS AND THUNDERSTORMS FROM MS/AL INTO NC/VA DURING THIS PERIOD. ...MS/AL/FL/GA... LOW LEVEL TRAJECTORIES ARE SOUTHEASTERLY ACROSS MUCH OF THE FL PENINSULA AND EASTERN GULF OF MEXICO. THIS IS NOT TAPPING THE TROPICAL MOISTURE FARTHER SOUTH...AND IS ONLY RESULTING IN DEWPOINTS IN THE LOWER 60S ACROSS THE FL PANHANDLE. ONLY MODEST INCREASES IN MOISTURE ARE EXPECTED IN THIS AREA TODAY. THUS...MLCAPE VALUES WILL GENERALLY BE BELOW 500 J/KG OVER PARTS OF MS/AL/GA/FL. ISOLATED STORMS ALONG THE COAST MAY POSE A RISK OF LOCALLY GUSTY WINDS OR A BRIEF TORNADO. HOWEVER...OVERALL THREAT APPEARS RATHER LOW. ...SC/NC... LOW LEVEL MOISTURE/INSTABILITY IS ALSO FORECAST TO INCREASE THIS AFTERNOON OVER THE CAROLINAS AS SURFACE CYCLOGENESIS OCCURS AND SOUTHEASTERLY LOW LEVEL WINDS STRENGTHEN. SURFACE WARM FRONT WILL LIKELY DEVELOP ALONG OR JUST OFF THE COAST AND MOVE SLOWLY INLAND AHEAD OF LOW. WIDESPREAD PRECIPITATION IS LIKELY TO PRECLUDE STRONG DAYTIME HEATING IN THIS AREA. NEVERTHELESS...MARGINAL INSTABILITY MAY BE SUFFICIENT GIVEN STRONG LOW LEVEL WINDS VEERING/INCREASING WITH HEIGHT AND LARGE SCALE FORCING. STRONGEST CELLS COULD PRODUCE DAMAGING WINDS OR A TORNADO. WILL MAINTAIN ONLY LOW SEVERE PROBABILITIES AT THIS TIME DUE TO LOW CONFIDENCE IN THE DEVELOPMENT OF STRONGER INSTABILITY. ..HART/CROSBIE.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 16:38:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 11:38:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071639 SWODY1 SPC AC 071637 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1037 AM CST TUE NOV 07 2006 VALID 071630Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG MID/UPPER LEVEL LOW OVER THE MIDDLE TN VALLEY THIS MORNING IS EXPECTED TO SLOWLY DRIFT EWD OVER THE NC/SC/GA TRIPLE POINT DURING THE REMINDER OF THE PERIOD. STRONG NRN BRANCH WILL EXTEND FROM THE PACIFIC NORTHWEST INTO THE NRN PLAINS AND UPPER GREAT LAKES AS MID LEVEL RIDGING HOLDS OVER THE SWRN U.S. MORNING SFC ANALYSIS INDICATED LOW OVER NWRN TN WITH AN OCCLUSION EXTENDING SWD THROUGH THE CENTRAL FL PANHANDLE. A WARM FRONTAL/CONVECTIVE BOUNDARY EXTENDED FROM THE NERN GULF OF MEXICO EWD ACROSS NRN FL WITH STRONG LARGE SFC RIDGING ANCHORED JUST SE OF NEW ENGLAND BRINGING NELY FLOW ACROSS PARTS OF THE MID ATLANTIC REGION. ...ERN CAROLINAS... MORNING NAM IS WEAK ON THE DETAILS OF DEVELOPING SFC LOW ANYWHERE FROM NRN FL INTO CENTRAL SC/NC LATER THIS AFTERNOON AND TONIGHT. LATEST RUC FORECAST BRINGS THE LOW THRU THE ERN FL PANHANDLE INTO S CENTRAL GA BY 08/00Z WHICH IS CLOSER TO WHAT MAY REALLY HAPPEN. USUALLY IN THESE CASES CONSIDERING THE STRONG PRESSURES OVER THE MID ATLANTIC REGION...THE SURFACE LOW DEVELOPMENT WILL DEPEND ON THE COLD AIR DAMMING ALONG THE ERN APPALACHIANS AND THE GULF STREAM OFF COAST CAROLINA. SO...THINK THAT ONE LOW WILL BE A REFLECTION OF THE UPPER LOW OVER NRN GA...WHILE ANOTHER LOW WILL DEVELOP ALONG THE WARM FRONT N OF JAX THAT WILL MOVE NWD ALONG THE COASTAL AREAS. MODELS DEPICT VERY STRONG SHEAR PROFILES IN THE HODOGRAPHS DUE TO STRONG GRADIENT FLOW DEVELOPING BY 08/00Z. HOWEVER...WEAK LOW/MID LEVEL LAPSE RATES AND INSTABILITY MAKES FOR A LOW PROBABILITY FOR TORNADOES/WATERSPOUTS OVER THE CAROLINAS EARLY TONIGHT. ELSEWHERE...STRONG THUNDERSTORMS COULD MOVE INTO THE TPA AREA NWD...OR ACROSS PARTS OF THE KEYS AS WEAK SFC LOW OFFSHORE MOVES EWD THEN WEAKENS DUE TO CURRENT CONVECTION NW OF THE TPA AREA. ..MCCARTHY/JEWELL.. 11/07/2006  From swody1 at goshenarc.org Tue Nov 7 19:38:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 14:38:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 071940 SWODY1 SPC AC 071937 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0137 PM CST TUE NOV 07 2006 VALID 072000Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...FL PENINSULA... LAPSE RATES ACROSS THE CNTRL/SRN PENINSULA HAVE BEEN SLOW TO STEEPEN AHEAD OF UPPER TROUGH DUE IN LARGE PART TO EXTENSIVE CLOUDINESS AND PRECIPITATION. LATEST RADAR DATA SUGGESTS STRONGEST CONVECTION REMAINS OVER WARM WATERS OF THE ERN GULF WHERE BUOYANCY IS A BIT GREATER. OF PARTICULAR CONCERN IS THE WELL ORGANIZED COMPLEX APPROACHING THE WCNTRL COAST. A LONG-LIVED MVC IS LOCATED JUST NW OF PIE WITH A BAND OF STRONG STORMS EXTENDING FROM E-SW OF CIRCULATION CENTER. AIRMASS INLAND IS NOT PARTICULARLY UNSTABLE AND IT APPEARS THE GREATEST THREAT WITH THIS ACTIVITY WILL BE STRONG WINDS AND PERHAPS AN ISOLATED SEVERE GUST. ALTHOUGH THIS CLUSTER OF ORGANIZED STORMS WILL LIKELY MOVE ACROSS THE CNTRL PENINSULA...ORGANIZED DAMAGING WINDS ARE NOT EXPECTED...AND GRADUAL WEAKEN IS CERTAINLY POSSIBLE OVER MORE STABLE INLAND AREAS. ...CAROLINA COAST... LATER TONIGHT LOW LEVEL WARM ADVECTION WILL INCREASE IN THE WAKE OF CURRENT EJECTING SHORTWAVE. REGIONAL RADAR DATA EXHIBITS A WELL DEFINED VORT CENTER ALONG THE NC/SC BORDER...JUST ENE OF FLO. BROADER PRECIPITATION SHIELD WILL LIFT NORTH OF THIS REGION WITH GRADUAL BOUNDARY LAYER DESTABILIZATION EXPECTED OVER THE NEXT 6-18 HOURS. IT APPEARS MODIFIED MARITIME AIRMASS WILL SPREAD INLAND ENHANCING THE BUOYANCY AND THUNDERSTORM POTENTIAL AHEAD OF MAIN UPPER TROUGH. IF SUFFICIENT INSTABILITY CAN SPREAD INLAND THEN SUPERCELLS ARE CERTAINLY POSSIBLE...AND TORNADO THREAT MAY INCREASE...ESPECIALLY AFTER DARK. COASTAL SC/NC WILL BE MONITORED AT 01Z OUTLOOK FOR POSSIBLE UPGRADE TO SLIGHT RISK. ..DARROW.. 11/07/2006  From swody1 at goshenarc.org Wed Nov 8 00:59:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 07 Nov 2006 19:59:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080101 SWODY1 SPC AC 080059 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0659 PM CST TUE NOV 07 2006 VALID 080100Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SRN FL... SUPERCELL WHICH PRODUCED SEVERAL TORNADO REPORTS ACROSS CENTRAL AND E CENTRAL FL EARLIER HAS MOVED OFFSHORE. MEANWHILE...BOUNDARY-LAYER FLOW ACROSS THE REMAINDER OF E CENTRAL AND INTO SRN FL IS MORE SWLY...RESULTING IN LESS FAVORABLE LOW-LEVEL SHEAR. THEREFORE...GREATEST TORNADO THREAT APPEARS TO HAVE PASSED. DEGREE OF INSTABILITY AND DEEP-LAYER SHEAR SE OF FRONT -- WHICH LIES NNE-SSW ACROSS CENTRAL FL -- REMAINS SUFFICIENT FOR A FEW STRONGER/ROTATING STORMS. HOWEVER...MARGINAL SEVERE THREAT IS FORECAST TO FURTHER DIMINISH WITH TIME...GIVEN WEAK LOW-LEVEL CONVERGENCE AND SLOWLY STABILIZING BOUNDARY LAYER. ...COASTAL CAROLINAS... MOIST /LOW TO MID 60S DEWPOINTS/ BOUNDARY LAYER HAS WORKED INLAND ACROSS NERN SC AND INTO ERN SC...E AND NE OF WEAK SURFACE LOW OVER ERN SC. DESPITE THIS...INSTABILITY IS MINIMAL -- PER LATEST OBJECTIVE ANALYSES...AND EVENING RAOBS WHICH REVEAL VERY WEAK LAPSE RATES. GIVEN AMPLE LOW-LEVEL SHEAR AND FAIRLY MOIST BOUNDARY LAYER...WILL MAINTAIN A VERY LOW-PROBABILITY THREAT FOR A BRIEF TORNADO. HOWEVER...THREAT WILL CONTINUE TO DIMINISH THROUGH THE EVENING AS SURFACE LOW/FRONT MOVES OFFSHORE. ..GOSS.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 05:46:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 00:46:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 080547 SWODY1 SPC AC 080546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST TUE NOV 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE UPPER PATTERN IS FORECAST THIS PERIOD AS A LOW-AMPLITUDE TROUGH MOVES INTO THE WRN U.S. AND A STRONGER TROUGH/UPPER LOW MOVES EWD ACROSS THE ERN CONUS. IN BETWEEN...A LOW-AMPLITUDE RIDGE WILL SHIFT EWD ACROSS THE S CENTRAL 2/3 OF THE COUNTRY. AT THE SURFACE...COLD FRONT SHOULD EXTEND FROM A SURFACE LOW IN ERN NC SWD/SWWD ACROSS SRN FL AT THE START OF THE PERIOD. THIS LOW SHOULD MOVE NWD WITH TIME TOWARD SRN NEW ENGLAND...WHILE COLD FRONT MOVES EWD INTO THE ATLANTIC/SEWD ACROSS FL. A SECOND COLD FRONT EXTENDING ENE-WSW ACROSS THE NWRN CONUS SHOULD MOVE SEWD ACROSS THE ROCKIES/NRN AND CENTRAL PLAINS...AS ASSOCIATED LOW MOVES FROM SRN ALBERTA RAPIDLY EWD TOWARD JAMES BAY THROUGH THE END OF THE PERIOD. ...S FL... A FEW SHOWERS AND PERHAPS A THUNDERSTORM OR TWO MAY DEVELOP OVER S FL AND THE KEYS AHEAD OF SWD-MOVING COLD FRONT DURING THE FIRST HALF OF THE PERIOD. WEAK CONVERGENCE ALONG FRONT AND LIMITED INSTABILITY SUGGESTS VERY LITTLE IF ANY SEVERE THREAT. ...SRN NEW ENGLAND INTO THE CAROLINAS... EFFECTIVE SURFACE BOUNDARY IS FORECAST TO BE OFF THE SERN U.S. COAST BY THE START OF THE PERIOD. HOWEVER...COLD AIR ALOFT ASSOCIATED WITH UPPER LOW MOVING EWD ACROSS THE CAROLINAS/MID-ATLANTIC REGION MAY COMBINE WITH LIMITED DAYTIME HEATING TO YIELD MARGINAL INSTABILITY. THUS...WILL MAINTAIN THUNDER FORECAST ACROSS THIS REGION -- AND EXPAND IT NEWD INTO SRN NEW ENGLAND...WHERE A FEW STRIKES COULD OCCUR DURING THE LATTER HALF OF THE PERIOD. ...PAC NW... AS LOW-AMPLITUDE UPPER TROUGH AND ASSOCIATED COLDER AIR ALOFT /-28 TO -30C AT H5/ SETTLES EWD INTO THE PAC NW...A FEW LIGHTNING STRIKES WILL BE POSSIBLE WITHIN LARGER AREA OF CONVECTIVE PRECIPITATION. GREATEST POTENTIAL WILL LIKELY EXIST THROUGH THE AFTERNOON NEAR DIURNAL PEAK HEATING. ...NERN ND INTO THE WRN UPPER GREAT LAKES REGION... A FEW LIGHTNING STRIKES WILL BE POSSIBLE ACROSS PORTIONS OF THE N CENTRAL CONUS -- AND PARTICULARLY ACROSS THE BORDER INTO S CENTRAL CANADA -- AS SHORT-WAVE TROUGH AND ASSOCIATED SURFACE LOW MOVE QUICKLY EWD ACROSS THIS REGION. ..GOSS.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 12:49:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 07:49:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081250 SWODY1 SPC AC 081248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0648 AM CST WED NOV 08 2006 VALID 081300Z - 091200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH OVER THE SOUTHEASTERN STATES WILL MOVE SLOWLY EASTWARD AND OFFSHORE BY THURSDAY MORNING. MEANWHILE...LOW AMPLITUDE UPPER TROUGH WILL MOVE RAPIDLY EASTWARD ACROSS THE WESTERN STATES. ALTHOUGH THREAT OF SEVERE THUNDERSTORMS APPEARS RATHER LOW TODAY...SEVERAL AREAS MAY SEE ISOLATED THUNDERSTORM ACTIVITY. ...MID ATLANTIC INTO SOUTHERN NEW ENGLAND... LINGERING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY FROM THE MID ATLANTIC REGION INTO SOUTHERN NEW ENGLAND. DESPITE ONLY MARGINAL INSTABILITY...LARGE SCALE FORCING FOR ASCENT IS QUITE STRONG AHEAD OF UPPER TROUGH. THREAT SHOULD DIMINISH FROM WEST TO EAST ACROSS THE MID ATLANTIC REGION DURING THE DAY...WHILE POTENTIAL FOR CONVECTION MAY CONTINUE OVER SOUTHERN NEW ENGLAND THROUGH THE NIGHT. NO ORGANIZED SEVERE STORMS ARE ANTICIPATED. ...CAROLINAS... CORE OF UPPER LOW WILL MOVE ACROSS SC/NC TODAY. POCKET OF COLD MID LEVEL TEMPERATURES /-20C AT 500MB/ WILL YIELD RELATIVELY STEEP MID LEVEL LAPSE RATES AND MARGINAL INSTABILITY. SCATTERED AFTERNOON THUNDERSTORMS MAY DEVELOP IN THIS REGION...BEFORE QUICKLY DIMINISHING AFTER DARK. SMALL HAIL WILL BE POSSIBLE IN STRONGER STORMS...BUT POTENTIAL FOR SEVERE STORMS APPEARS LOW. ...SOUTH FL... SECONDARY SHORTWAVE TROUGH IS EVIDENT IN WATER VAPOR IMAGERY OVER THE EASTERN GULF OF MEXICO. THIS FEATURE WILL MOVE ACROSS THE FL PENINSULA TODAY...PROVIDING A THREAT OF ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS. ...PACIFIC NORTHWEST... STRONG ONSHORE FLOW WILL CONTINUE ALONG THE WA/ORE COAST TODAY AHEAD OF APPROACHING UPPER TROUGH. COOLING TEMPERATURES ALOFT AND OROGRAPHIC FORCING WILL AID IN THE THREAT OF ISOLATED THUNDERSTORMS. ...UPPER MIDWEST AND WESTERN GREAT LAKES... FAST MOVING UPPER JET MAX OVER MT/ND WILL TRACK EASTWARD ALONG THE US/CANADIAN BORDER TODAY. STEEP MID LEVEL LAPSE RATES AND UPPER FORCING WILL AID IN THE DEVELOPMENT OF MARGINAL ELEVATED INSTABILITY LATER TODAY. FORECAST SOUNDINGS IN THIS REGION SUGGEST SUFFICIENT CAPE ABOVE AN ELEVATED MIXED LAYER FOR A RISK OF ISOLATED THUNDERSTORMS. ACTIVITY MAY SPREAD INTO MI DURING THE EVENING. NO SEVERE STORMS ARE FORECAST. ..HART/BOTHWELL.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 16:28:20 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 11:28:20 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081629 SWODY1 SPC AC 081627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST WED NOV 08 2006 VALID 081630Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... COMPACT UPPER LOW WILL CONTINUE EWD ACROSS THE SERN STATES...WITH WEAK TROUGH EXTENDING NWD INTO THE NERN U.S. BEHIND THIS SYSTEM...UPPER RIDGE WILL EXIST ACROSS THE CNTRL/SRN PLAINS PROVIDING WARM AND DRY CONDITIONS. TO THE W...BROAD UPPER TROUGH WILL CONTINUE TO SHIFT EWD ACROSS THE PACIFIC NW/NRN ROCKIES AS VORTICITY CENTER MOVES ASHORE LATER TODAY INTO WA/ORE. FINALLY...A LOW AMPLITUDE BUT POTENT UPPER TROUGH WILL SKIRT ALONG THE U.S./CANADA BORDER BRINGING A SLIM CHANCE OF A THUNDERSHOWER FROM NRN MN INTO THE WRN GREAT LAKES. ...MID ATLANTIC REGION... VERY COOL MID LEVEL TEMPERATURES EXIST WITHIN UPPER LOW CENTER...WITH -21.1 C AT FFC THIS MORNING AT 500 MB. POCKETS OF SURFACE HEATING ACROSS THE CAROLINAS MAY ALLOW FOR ENOUGH CONVECTIVE INSTABILITY TO DEVELOP FOR A FEW THUNDERSTORMS AS MAIN SURFACE LOW DEEPENS TO THE NE. ...PACIFIC NW... VERY COOL TEMPERATURES ALOFT/STEEP LAPSE RATES WILL EXIST AS STRONG TROUGH ENTERS THE REGION. SHORELINE CONVERGENCE WITH WEAK SURFACE TROUGH COMBINED WITH HEIGHT FALLS/COOLING ALOFT WILL SUPPORT SCATTERED STORMS OVER THE OCEAN AND LIKELY INLAND TO THE W SLOPES OF THE CASCADES. ..JEWELL/MCCARTHY.. 11/08/2006  From swody1 at goshenarc.org Wed Nov 8 19:19:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 14:19:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 081921 SWODY1 SPC AC 081918 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0118 PM CST WED NOV 08 2006 VALID 082000Z - 091200Z ...NO SVR TSTM AREAS FORECAST... THE SOUTHERN BRANCH CLOSED LOW IS BEGINNING TO LIFT OUT OF THE SOUTHEASTERN STATES. IN ITS WAKE...A SURFACE RIDGE OVER THE GULF OF MEXICO...AND BROAD RIDGING ALOFT...FROM THE FOUR CORNERS STATES THROUGH THE CENTRAL/SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY...ARE CONTRIBUTING TO A GENERALLY STABLY STRATIFIED ENVIRONMENT ACROSS MUCH OF THE NATION. A COUPLE AREAS WITH LIMITED CONVECTIVE POTENTIAL DO EXIST...BUT PROBABILITY OF THUNDERSTORMS EVEN IN THESE AREAS IS LOW. ...PACIFIC NORTHWEST/NORTHERN GREAT BASIN... ISOLATED/WIDELY SCATTERED THUNDERSTORMS ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL BE POSSIBLE THIS AFTERNOON FROM COASTAL AREAS INTO THE WESTERN SLOPES OF THE CASCADES...AS UPPER TROUGH PROGRESSES INLAND. ONSHORE FLOW IS GENERALLY WEAK...BUT BECOMING FOCUSED ACROSS THE OREGON COAST...WHERE BEST CHANCE FOR STORMS EXISTS. OTHERWISE...DESTABILIZATION HAS BECOME SUFFICIENT FOR WEAK THUNDERSTORM ACTIVITY IN A ZONE OF STRONGER FORCING ALONG FRONT NOW ADVANCING SLOWLY SOUTHWARD ACROSS THE NORTHERN INTERMOUNTAIN REGION INTO THE NORTHERN GREAT BASIN. ADDITIONAL WIDELY SCATTERED STORMS APPEAR POSSIBLE EASTWARD INTO SOUTHEASTERN IDAHO...WITH SOUTHWARD DEVELOPMENT THROUGH NORTH CENTRAL NEVADA/NORTHERN UTAH BY EARLY THIS EVENING EVENING...BEFORE ACTIVITY DIMINISHES WITH LOSS OF DAYTIME HEATING. ...UPPER GREAT LAKES... WEAK...MID-LEVEL BASED CONVECTION IS EVIDENT IN WARM ADVECTION REGIME SPREADING ACROSS PARTS OF LAKE SUPERIOR AND THE UPPER PENINSULA OF MICHIGAN...ASSOCIATED WITH A NORTHERN BRANCH SHORT WAVE TROUGH NEAR THE CENTRAL U.S./CANADIAN BORDER. AN ISOLATED WEAK THUNDERSTORM OR TWO STILL APPEARS POSSIBLE THIS AFTERNOON ...BEFORE FORCING SHIFTS OFF INTO SOUTHERN ONTARIO. ...ATLANTIC COAST... CONVECTIVE DEVELOPMENT IS ONGOING ACROSS PARTS OF SOUTHEAST VIRGINIA...WHERE THE BOUNDARY LAYER REMAINS MOIST AND WEAKLY UNSTABLE...ALTHOUGH THE SURFACE LOW IS NOW DEVELOPING EAST OF THE DELMARVA PENINSULA. UPPER FLOW REMAINS DIVERGENT ACROSS MID ATLANTIC COASTAL AREAS...AHEAD OF UPPER TROUGH AXIS PIVOTING OFF THE SOUTH ATLANTIC COAST...AND THIS COULD CONTRIBUTE TO ADDITIONAL ISOLATED THUNDERSTORMS LATE THIS AFTERNOON/EARLY THIS EVENING. OTHERWISE...THUNDERSTORMS REMAIN POSSIBLE LATER TODAY/TONIGHT IN LOW-LEVEL WARM ADVECTION REGIME LIFTING UP MIDDLE/NORTHERN ATLANTIC COASTAL AREAS...IN ADVANCE OF SURFACE CYCLONE. ..KERR.. 11/08/2006  From swody1 at goshenarc.org Thu Nov 9 00:50:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 08 Nov 2006 19:50:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090052 SWODY1 SPC AC 090050 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 PM CST WED NOV 08 2006 VALID 090100Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A FEW AREAS OF ACTIVE BUT ISOLATED CONVECTION MAY PERSIST OVER THE NEXT FEW HOURS ACROSS THE CONUS. FROM WEST TO EAST...THE NEXT SHORT WAVE TROUGH MOVING ASHORE OVER THE PACIFIC NORTHWEST WILL CONTINUE TO ACT UPON MOIST ONSHORE LOW LEVEL FLOW TO PROMOTE A FEW SCATTERED TSTMS FROM THE COASTAL RANGES TO THE CASCADES. FROM THE NRN SIERRA RANGE ACROSS THE GREAT BASIN...LIFT AND WEAK INSTABILITY ALONG DEEP LAYER BAROCLINIC BAND WILL PROVIDE IMPETUS FOR A FEW LIGHTNING STRIKES OVER THE NEXT FEW HOURS. A FAST-MOVING IMPULSE EMBEDDED WITHIN NEARLY ZONAL FLOW ACROSS SCNTRL CANADA AND THE NRN PLAINS WILL CONTINUE TO TREK EAST ACROSS THE NRN GREAT LAKES TONIGHT. FORCING WITH THIS IMPULSE MAY SUPPORT ISOLATED CONVECTION ON THE NOSE OF LOW LEVEL WARM CONVEYOR BELT FROM NRN WI INTO THE NRN PARTS OF LOWER MI. FINALLY...STRONG ASCENT WITHIN DEFORMATION AXIS NORTH OF ERN CAROLINAS CLOSED LOW MAY CONTINUE TO CONTRIBUTE TO ISOLATED TSTMS ACROSS THE VA/NC CAPES TONIGHT. ..CARBIN.. 11/09/2006  From swody1 at goshenarc.org Thu Nov 9 05:57:03 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 09 Nov 2006 00:57:03 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 090558 SWODY1 SPC AC 090556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST WED NOV 08 2006 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE SHORT WAVE TROUGH...CURRENTLY MOVING OVER THE PACIFIC NORTHWEST...WILL CONTINUE TO TRACK ACROSS THE NRN GREAT BASIN THROUGH 12Z TODAY BEFORE MOVING ACROSS THE ROCKIES AND INTO THE NRN/CNTRL PLAINS BY 12Z FRIDAY. HEIGHT FALLS WITH THIS DISTURBANCE WILL CONTRIBUTE TO LEE CYCLOGENESIS OVER CO LATER TODAY. AS THE UPPER TROUGH SPREADS OVER THE PLAINS STATES LATER TONIGHT...THE ASSOCIATED SURFACE LOW PRESSURE AREA WILL REFORM ALONG A DEEP-LAYER BAROCLINIC ZONE BISECTING THE PLAINS FROM IA SWWD TO OK. ...INTERMOUNTAIN REGION... COLD AIR ALOFT ASSOCIATED WITH THE SHORT WAVE TROUGH EMANATING FROM THE PACIFIC NORTHWEST WILL CONTRIBUTE TO WEAK DESTABILIZATION /MUCAPE 100-200 J PER KG/ ACROSS PARTS OF NRN UT...WY...AND NWRN CO AREAS THIS AFTERNOON. WEAK CONVECTIVE DEVELOPMENT SHOULD ENSUE ACROSS THE HIGHER TERRAIN WHERE A FEW ISOLATED TO WIDELY SCATTERED TSTMS APPEAR POSSIBLE THROUGH EARLY EVENING. ...LOWER MO RIVER VALLEY... STRENGTHENING MOISTURE TRANSPORT AND LIFT IN ADVANCE OF THE APPROACHING TROUGH AND FRONTAL ZONE WILL CONTRIBUTE TO AN AXIS OF HIGHER THETA-E AIR AHEAD OF DEVELOPING SURFACE LOW FROM OK TO KS BY LATE TONIGHT. DESPITE INCREASING ISENTROPIC LIFT THROUGH LATE IN THE PERIOD ACROSS THIS AREA...WEAKER CAPPING AND STRONGER FORCING FOR ASCENT ARE FORECAST TO EXIST PRIMARILY NORTH OF THE RESULTING INSTABILITY AXIS...FROM NERN KS INTO SRN IA. LATEST GUIDANCE SUGGESTS FORCING AND DESTABILIZATION ALONG THE FRONTAL BAND AND AHEAD OF THE DEVELOPING SURFACE LOW WILL BE SUFFICIENT FOR CONVECTIVE INITIATION BY EARLY FRIDAY MORNING. THIS ACTIVITY WILL LIKELY EXIST ATOP A STABLE POST-FRONTAL ENVIRONMENT WHERE MUCAPE UP TO 500 J/KG AND STRONG SHEAR COULD CONTRIBUTE TO A VERY LOW PROBABILITY HAIL THREAT. GIVEN LATE IN THE PERIOD DEVELOPMENT AND SOME UNCERTAINTY IN DEGREE OF INSTABILITY...IT IS TOO EARLY TO INTRODUCE LOW SEVERE PROBABILITIES AT THIS TIME. ..CARBIN/LEVIT.. 11/09/2006  From swody1 at goshenarc.org Sat Nov 11 05:38:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 00:38:39 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 110539 SWODY1 SPC AC 110537 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 PM CST FRI NOV 10 2006 VALID 111200Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AN ACTIVE AND PROGRESSIVE MID/UPPER LEVEL WAVE TRAIN WILL CONTINUE INTO THE WEEKEND ACROSS THE U.S. AS ANOTHER STRONG TROUGH MOVES INLAND FROM THE INTERIOR NORTHWEST AND ACROSS THE ROCKIES...AND A COMPACT BUT POTENT SHORT WAVE TROUGH CLOSES OFF AND TAKES ON A NEGATIVE TILT FROM THE SRN APPALACHIANS ACROSS THE CAROLINAS/MID ATLANTIC. SYSTEM MOVING EAST FROM THE CNTRL U.S. EARLY TODAY IS EXPECTED TO UNDERGO FURTHER AMPLIFICATION AS IT EVOLVES INTO A CLOSED LOW BY LATE TONIGHT ACROSS THE SRN APPALACHIANS AND CAROLINAS. PRIMARY SURFACE LOW ASSOCIATED WITH THE STRONG UPPER TROUGH WILL START OUT THE PERIOD ACROSS THE ERN GREAT LAKES/PA/NY AREAS. WITH TIME... STRONG JET ENERGY MOVING THROUGH THE BASE OF THE UPPER TROUGH WILL INDUCE PRONOUNCED HEIGHT FALLS AND SECONDARY CYCLOGENESIS OVER THE MID ATLANTIC REGION THROUGH EARLY SUNDAY. THE COLD FRONT ACCOMPANYING THIS SYSTEM WILL EXTEND FROM OH TO LA THIS MORNING AND SHOULD REACH THE APPALACHIANS BY THIS EVENING. THE SRN SEGMENT OF THE FRONT IS FORECAST TO MOVE ACROSS THE SRN APPALACHIANS AND THEN SURGE OFF THE SOUTHEAST U.S COAST THROUGH SUNDAY MORNING AS DEEP-LAYER CYCLONE INTENSIFIES OVER ERN NC/VA. ...AL/GA ACROSS SRN/CNTRL APPALACHIANS...CAROLINAS/VA... A NARROW AXIS OF GREATER BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE 50S TO LOW 60S/ EXPECTED TO ADVECT NEWD AHEAD OF THE COLD FRONT FROM ERN AL...ACROSS GA...AND OVER PARTS OF THE WRN CAROLINAS THROUGH LATE TODAY. GENERALLY WEAK MID LEVEL LAPSE RATES ARE FORECAST TO LIMIT STRONGER DESTABILIZATION. HOWEVER...LIFT ALONG THE FRONT...AND INCREASINGLY STRONG DYNAMIC FORCING AND WIND FIELDS WITH THE APPROACHING UPPER TROUGH...SHOULD CONTRIBUTE TO THE DEVELOPMENT OF A NARROW LOW-TOPPED LINE OF CONVECTION THROUGH LATE EVENING FROM GA NNEWD TO VA. CONVECTION MAY BE MAINTAINED THROUGH THE NIGHT GIVEN STRONG CYCLOGENETIC FORCING FORECAST TO OCCUR ACROSS THE CAROLINAS AND VA. LACK OF GREATER INSTABILITY MAY BE OFFSET BY INCREASINGLY STRONG LIFT AND SHEAR TO SUPPORT AN ISOLATED SEVERE WIND GUST OR PERHAPS SOME MARGINALLY SEVERE HAIL. LOW SEVERE PROBABILITIES WILL BE MAINTAINED FOR THIS POTENTIAL. ...PACIFIC NORTHWEST... SHOWERS AND PERHAPS SOME EMBEDDED LIGHTNING APPEAR LIKELY AS WEAKLY UNSTABLE ONSHORE/UPSLOPE FLOW PERSISTS IN THE WAKE OF EWD-MOVING UPPER TROUGH. MOST LIKELY AREAS FOR ONSHORE THUNDER SHOULD BE LIMITED TO THE WINDWARD SLOPES OF THE OLYMPICS AND COASTAL RANGES. ..CARBIN/GRAMS.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 12:19:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 07:19:08 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111220 SWODY1 SPC AC 111218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST SAT NOV 11 2006 VALID 111300Z - 121200Z ...NO SVR TSTM AREAS FORECAST... TROUGH CURRENTLY MOVING ACROSS THE MID MS VALLEY IS PROGGED TO AMPLIFY TONIGHT CLOSING OFF AN UPPER LOW OVER THE CAROLINAS BY 12Z SUNDAY. COLD FRONT EXTENDS SWWD FROM THE SURFACE LOW OVER ERN OH VALLEY TO OFFSHORE TX COAST. BY TONIGHT A NEW SURFACE LOW WILL DEVELOP VA/NC AS UPSTREAM TROUGH INTENSIFIES. STRONG ASCENT TONIGHT AHEAD OF THIS SYSTEM WILL RESULT IN EXPANDING AREA OF PRECIPITATION CENTRAL APPALACHIANS EWD. WITH LITTLE GULF MOISTURE AVAILABLE OVER SERN U.S...INSTABILITY EXPECTED TO BE MEAGER AHEAD OF THE COLD FRONT AND TROUGH. WHILE SOME CONVECTION IS LIKELY...PARTICULARLY TONIGHT WITH THE INTENSIFYING UPPER SYSTEM...SEVERE STORMS NOT EXPECTED. ..HALES/GRAMS.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 16:28:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 11:28:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111630 SWODY1 SPC AC 111628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1028 AM CST SAT NOV 11 2006 VALID 111630Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... UPR TROUGH NOW OVER THE MID MS VLY EXPECTED TO AMPLIFY SUBSTANTIALLY TONIGHT/EARLY SUNDAY AS SYSTEM CONTINUES E/SE INTO NC/SRN VA. ASSOCIATED COLD FRONT NOW ALONG THE WRN SLOPES OF THE SRN APPALACHIANS SHOULD REACH WRN PARTS OF THE SW VA...NC AND SC PIEDMONT BY THIS EVENING...AND THE HATTERAS AREA BY 12Z SUNDAY...AS EXISTING SFC LOW FILLS OVER NW PA AND NEW CYCLOGENESIS OCCURS OVER TIDEWATER VA. WITH MAIN UPR JET STREAK/VORT MAX ASSOCIATED WITH MS VLY SYSTEM REMAINING WELL W OF SFC WARM SECTOR...MID LEVEL LAPSE RATES AND FORCING FOR ASCENT WILL REMAIN WEAK. THIS WILL LIMIT POTENTIAL FOR DEEP CONVECTION OVER THE CAROLINAS TODAY DESPITE UNINHIBITED SURFACE HEATING AND SHALLOW FRONTAL UPLIFT. LATER IN THE PERIOD...HOWEVER...DEEP FORCING FOR ASCENT LIKELY WILL OVERTAKE MOISTENING WARM SECTOR OVER FAR ERN NC AND PERHAPS TIDEWATER VA AS SECONDARY SFC CYCLONE STRENGTHENS. SATELLITE AND SFC OBSERVATIONS OFF THE S ATLANTIC CST ATTM SUGGEST THAT LOW LEVEL AIR MASS INVOLVED WILL BE OF MODIFIED POLAR CHARACTER...WITH A FAIRLY SHALLOW MODERATELY MOIST BOUNDARY LAYER /DEWPOINTS IN THE LOW 60S/. A BAND OR TWO OF CONVECTION/TSTMS MAY DEVELOP LATE IN THE PERIOD ALONG WRN EDGE OF MORE STRONGLY MODIFIED AIRMASS OVER EXTREME ERN NC AND THE ADJACENT CSTL WATERS NWD TO THE VA CAPES. WHILE ISOLATED STRONG WINDS WILL BE POSSIBLE WITH ANY SUCH ACTIVITY... UNFAVORABLE TIME OF DAY...WEAK LOW LEVEL LAPSE RATES AND LIMITED GEOGRAPHICAL AREA INVOLVED PRECLUDE ADDITION OF A SEVERE THREAT AREA ATTM. ..CORFIDI/GUYER.. 11/11/2006  From swody1 at goshenarc.org Sat Nov 11 19:49:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 14:49:56 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 111951 SWODY1 SPC AC 111949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SAT NOV 11 2006 VALID 112000Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC STATES... PRIMARY ZONE OF UPPER FORCING ASSOCIATED WITH AMPLIFYING MID/UPPER LEVEL TROUGH APPROACHING MID ATLANTIC REGION FROM THE LOWER OH/TN VALLEYS IS EXPECTED TO REMAIN WEST OF THE COLD FRONT THROUGH MUCH OF THIS FORECAST PERIOD. THUS...SHOWERS WITH EMBEDDED ELEVATED THUNDERSTORMS SHOULD REMAIN MAINLY POST-FRONTAL...WHILE WEAK LAPSE RATES/INSTABILITY PRECLUDE A SEVERE WEATHER THREAT. LATER TONIGHT /MOST LIKELY 09-12Z/...SURFACE CYCLOGENESIS IS PROGGED TO OCCUR OVER NERN NC TO THE VA TIDEWATER AREA IN RESPONSE TO STRONGER HEIGHT FALLS DEVELOPING EWD ACROSS THIS AREA AS THE CLOSED LOW EVOLVES OVER VA/NC BY 12Z SUNDAY. EARLY AFTERNOON SURFACE ANALYSIS SHOWED A COASTAL BOUNDARY EXTENDING SSW-NNE ACROSS FAR ERN NC TO FAR SERN VA WITH THE SURFACE LOW EXPECTED TO DEVELOP IN THE VICINITY OF THIS FRONT. SURFACE DEWPOINTS IN THE LOWER 60S EAST OF THIS BOUNDARY SHOULD SUPPORT WEAK INSTABILITY LATE TONIGHT...AND THE POTENTIAL FOR A BAND OR TWO OF CONVECTION/TSTMS. ALTHOUGH ISOLATED STRONG WIND GUSTS WOULD BE POSSIBLE WITH THIS ACTIVITY...TIME OF DAY...WEAK LOW LEVEL LAPSE RATES...AND LIMITED GEOGRAPHICAL AREA CONTINUE TO PRECLUDE ADDITION OF SEVERE WEATHER THREAT. ...SERN AL/FL PANHANDLE/SWRN GA... REGIONAL RADARS AND LIGHTNING DATA INDICATED THUNDERSTORMS HAVE DEVELOPED SINCE 1830Z ALONG THE COLD FRONT AS IT MOVED EWD INTO THE WRN FL PANHANDLE AND SERN AL. A NARROW MOIST AXIS EXTENDED NEWD INTO WRN GA AHEAD OF THE FRONT...SUPPORTING WEAK INSTABILITY. VEERED LOW LEVEL WINDS IN ADVANCE OF THIS BOUNDARY WILL CONTINUE TO LIMIT CONVERGENCE...WITH STORMS POTENTIALLY BECOMING UNDERCUT BY THE FRONT. WEAK INSTABILITY AND CONVERGENCE SHOULD MINIMIZE LIKELIHOOD FOR MORE ROBUST UPDRAFTS...DESPITE EFFECTIVE SHEAR VALUES OF 35-40 KT. A FEW WIND GUSTS WILL BE POSSIBLE...BUT OVERALL SEVERE WEATHER THREAT APPEARS TOO LOW TO INCLUDE SEVERE PROBABILITIES IN THIS OUTLOOK. ..PETERS.. 11/11/2006  From swody1 at goshenarc.org Sun Nov 12 00:45:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 11 Nov 2006 19:45:01 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120046 SWODY1 SPC AC 120044 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0644 PM CST SAT NOV 11 2006 VALID 120100Z - 121200Z ...NO SVR TSTM AREAS FORECAST... ...MIDDLE ATLANTIC STATES SWD TO FL... INTENSE SHORT WAVE TROUGH OVER THE TN VALLEY IS FORECAST TO EVOLVE INTO A CLOSED MID-LEVEL LOW LATE TONIGHT AS IT TRANSLATES EWD INTO THE PIEDMONT REGION. IN THE LOW-LEVELS...SURFACE COLD FRONT ALONG THE APPALACHIANS WILL SHIFT EWD INTO THE PIEDMONT AND COASTAL PLAIN WITH SECONDARY CYCLOGENESIS OCCURRING ALONG THE FRONT OVER ERN NC LATE TONIGHT INTO SUNDAY MORNING. RADAR AND LIGHTNING DATA INDICATE RECENT INTENSIFICATION OF STORMS OVER WRN NC INTO SWRN VA...PRESUMABLY AS STRONGER LARGE-SCALE FORCING OVERSPREADS FRONTAL ZONE. 12/00Z REGIONAL SOUNDINGS INDICATE THAT MARGINAL BOUNDARY LAYER MOISTURE AND WEAK MID-LEVEL LAPSE RATES ARE LIMITING AIR MASS DESTABILIZATION...EXCEPT NEAR THE FRONT OVER THE FL PENINSULA WHERE SOME WEAK INSTABILITY WAS PRESENT. INTENSE LARGE-SCALE FORCING OWING TO DEEPENING SYNOPTIC SYSTEM SHOULD SUPPORT SOME AIR MASS DESTABILIZATION OVERNIGHT WITH ISOLATED TO WIDELY SCATTERED TSTMS FORECAST ALONG FRONTAL ZONE. SOME THREAT OF GUSTY WINDS AND/OR SMALL HAIL WILL EXIST WITH STRONGEST STORMS. HOWEVER...ANY MORE ORGANIZED SEVERE THREAT SHOULD REMAIN CONFINED TO REGION OF COMPARABLY STRONGER CONVECTIVE INSTABILITY ALONG THE GULF STREAM TOWARD THE END OF THE FORECAST PERIOD. ..MEAD.. 11/12/2006  From swody1 at goshenarc.org Sun Nov 12 05:14:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 12 Nov 2006 00:14:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120516 SWODY1 SPC AC 120514 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1114 PM CST SAT NOV 11 2006 VALID 121200Z - 131200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID AND UPPER-LEVEL LOW OVER THE PIEDMONT REGION AT THE BEGINNING OF THE FORECAST PERIOD WILL SLOWLY SHIFT EWD INTO THE WRN ATLANTIC BY TONIGHT. MEANWHILE...A MORE PROGRESSIVE SHORT WAVE TROUGH /NOW OVER THE LOWER CO VALLEY/ WILL TRANSLATE EWD THROUGH THE CNTRL/SRN ROCKIES INTO THE PLAINS STATES LATER TODAY. IN THE LOW-LEVELS...SURFACE CYCLONE ATTENDANT TO ERN U.S. UPPER LOW IS FORECAST TO UNDERGO OCCLUSION AS IT SLOWLY DEVELOPS NEWD FROM NERN NC INTO THE ATLANTIC. ASSOCIATED COLD FRONT WILL PUSH EWD OFF THE NC COAST EARLY IN THE PERIOD. TO THE W...PACIFIC COLD FRONT /INITIALLY FROM THE ERN DAKOTAS INTO CNTRL HIGH PLAINS/ WILL PUSH SEWD THROUGH THE MO VALLEY AND CNTRL INTO SRN PLAINS. ...SRN NEW ENGLAND SWD THROUGH THE TIDEWATER TO ERN NC... CLUSTERS OF TSTMS MAY BE ONGOING AT THE ONSET OF THE FORECAST PERIOD ALONG COLD FRONT AND INVOF DEEPENING CYCLONE OVER ERN NC WITHIN ZONE OF STRONG DEEP LAYER FORCING FOR ASCENT. MARGINAL BOUNDARY LAYER MOISTURE AND LAPSE RATES WILL LIMIT THE DEGREE OF INSTABILITY WITHIN PREFRONTAL AIR MASS ACROSS ERN NC AND THE OUTER BANKS. SOME POTENTIAL WILL EXIST FOR A FEW STRONG STORMS CAPABLE OF GUSTY WINDS/SMALL HAIL THROUGH THE MORNING HOURS OWING TO THE INTENSE FORCING AND RELATIVELY STRONG WIND FIELDS. HOWEVER...THE GREATER SEVERE THREAT SHOULD REMAIN OFFSHORE...NEARER TO THE GULF STREAM. OTHER ISOLATED STORMS WILL BE POSSIBLE N AND NW OF OCCLUDING SYNOPTIC SYSTEM ALONG THE MIDDLE ATLANTIC AND SRN NEW ENGLAND COASTS AS STRONG LOW-LEVEL WAA CONTRIBUTES TO AIR MASS DESTABILIZATION AND WEAK ELEVATED CONVECTIVE INSTABILITY. ...PACIFIC NW COAST... A SIMILAR ENVIRONMENT TO CURRENT IS FORECAST TO PERSIST THROUGH THE MORNING HOURS AS MOIST ONSHORE FLOW AND RELATIVELY COLD MID-LEVEL TEMPERATURES CONTRIBUTE TO A WEAKLY UNSTABLE ENVIRONMENT. TSTM POTENTIAL SHOULD TEND TO DIMINISH LATER TODAY AS LOW-LEVEL WIND FIELDS BACK IN RESPONSE TO THE APPROACH OF THE NEXT SYNOPTIC SYSTEM FROM THE NERN PACIFIC. ..MEAD/GRAMS.. 11/12/2006  From swody1 at goshenarc.org Mon Nov 20 00:42:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 19 Nov 2006 19:42:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200045 SWODY1 SPC AC 200043 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0643 PM CST SUN NOV 19 2006 VALID 200100Z - 201200Z ...NO SVR TSTM AREAS FORECAST... ...OLYMPIC PENINSULA... STRONG HEIGHT FALLS ARE FORECAST ACROSS REGION TONIGHT AS INTENSE MID AND UPPER-LEVEL JET STREAKS DEVELOP SEWD FROM THE FAR ERN PACIFIC AND BRITISH COLUMBIA INTO WA AND ORE. 20/00Z UIL SOUNDING INDICATES THAT RELATIVELY STEEP 0-3 KM AGL LAPSE RATES ARE CONTRIBUTING TO A WEAKLY UNSTABLE ENVIRONMENT WITH MUCAPES OF 100-200 J/KG AND EQUILIBRIUM LEVEL TEMPERATURES OF AROUND -19 TO -20 C. FURTHER DESTABILIZATION IS EXPECTED OVERNIGHT AS HEIGHT FALLS/DYNAMIC COOLING ON CYCLONIC SIDE OF MID-LEVEL JET STREAK INCREASE FROM THE NW. AS SUCH...EXPECT ISOLATED TSTM ACTIVITY /PER OCEANIC LIGHTNING DATA/ CURRENTLY 100-120 NM OFFSHORE TO GRADUALLY MOVE/DEVELOP INLAND LATER TONIGHT. ..MEAD.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 05:20:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 00:20:36 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 200523 SWODY1 SPC AC 200521 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 PM CST SUN NOV 19 2006 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... AMPLIFIED...FULL LATITUDE TROUGH WILL PERSIST ACROSS ERN PARTS OF CANADA AND THE U.S. THIS PERIOD WHILE IN THE W...A BELT OF STRONG...MID AND UPPER LEVEL CYCLONIC FLOW WILL EXIST FROM THE ERN PACIFIC INTO THE NRN PLAINS AND S-CNTRL CANADA. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS INTENSIFYING SRN BRANCH OF ERN U.S. TROUGH AND ATTENDANT SURFACE LOW OVER THE GULF STREAM WILL LIKELY FOCUS THE MAJORITY TSTM DEVELOPMENT THIS FORECAST OFF THE SERN ATLANTIC COAST. OTHER MORE ISOLATED TSTM ACTIVITY MAY OCCUR ALONG THE WA/ORE COASTS...ESPECIALLY OVERNIGHT...AS NEXT STRONG SHORT WAVE TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM APPROACH FROM THE W. HERE...INCREASED LARGE-SCALE FORCING AND RESULTANT STEEPENING OF LAPSE RATES WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR A FEW STORMS EMBEDDED WITHIN FRONTAL PRECIPITATION BAND. ..MEAD/BOTHWELL.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 12:30:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 07:30:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201233 SWODY1 SPC AC 201231 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0631 AM CST MON NOV 20 2006 VALID 201300Z - 211200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFIED...FULL LATITUDE TROUGH WILL PERSIST ACROSS ERN PARTS OF CANADA AND THE U.S. THIS PERIOD WHILE IN THE W...A BELT OF STRONG...MID AND UPPER LEVEL CYCLONIC FLOW WILL EXIST FROM THE ERN PACIFIC INTO THE NRN PLAINS AND S-CNTRL CANADA. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS INTENSIFYING SRN BRANCH OF ERN U.S. TROUGH AND ATTENDANT SURFACE LOW OVER THE GULF STREAM WILL LIKELY FOCUS THE MAJORITY TSTM DEVELOPMENT THIS FORECAST OFF THE SERN ATLANTIC COAST. OTHER MORE ISOLATED TSTM ACTIVITY MAY OCCUR ALONG THE WA/ORE COASTS...ESPECIALLY OVERNIGHT...AS NEXT STRONG SHORT WAVE TROUGH AND ASSOCIATED SURFACE FRONTAL SYSTEM APPROACH FROM THE W. HERE...INCREASED LARGE-SCALE FORCING AND RESULTANT STEEPENING OF LAPSE RATES WILL CONTRIBUTE TO SUFFICIENT INSTABILITY FOR A FEW STORMS EMBEDDED WITHIN FRONTAL PRECIPITATION BAND. ..EVANS/MEAD.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 16:28:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 11:28:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 201632 SWODY1 SPC AC 201629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST MON NOV 20 2006 VALID 201630Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SERN ATLANTIC COAST... A LONGWAVE TROUGH WILL CONTINUE TO PERSIST ACROSS THE ERN CONUS THROUGH TONIGHT WITH EVENTUAL DEVELOPMENT OF A CLOSED LOW OVER NRN FL BY 12Z TUE. ATTENDANT SFC LOW ALREADY EVIDENT IN BUOY STREAMLINE ANALYSIS OFF THE SC/GA COASTS WILL INTENSIFY. INTENSIFYING CONVEYOR BELT ON THE NWRN PERIPHERY OF THIS DEVELOPING CYCLONE WILL WRAP MOISTURE IN THE MID-UPPER LEVELS FROM THE GULF STREAM WWD TO THE SERN ATLANTIC COAST BY 12Z TUE. MOST SUBSTANTIAL DESTABILIZATION AND TSTM PROBABILITIES SHOULD REMAIN OFFSHORE...HOWEVER. ...COASTAL WA/ORE... WEAK MID-LEVEL SHORTWAVE TROUGH CONTINUES TO MIGRATE NEWD ACROSS CNTRL WA THIS MORNING. IN WAKE OF THIS IMPULSE...THERE WILL BE A BRIEF PERIOD OF WARMING AND RIDGING ALOFT THROUGH THIS EVE. NEXT DISTURBANCE...NOW LOCATED NEAR 40N/140W WILL BE APPROACHING THE COAST BY 12Z TUE WITH STRONG LOW/MID-LEVEL FRONTOGENESIS JUST OFFSHORE. COLD/UNSTABLE AIR MASS ALREADY IN PLACE JUST OFFSHORE COMBINED WITH STRONG MESOSCALE LIFT WILL RESULT IN AN UPSWING IN TSTM PROBABILITIES ALONG COASTAL WA/ORE LATER TONIGHT AS THE FRONT APPROACHES. ..RACY/TAYLOR.. 11/20/2006  From swody1 at goshenarc.org Mon Nov 20 19:57:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 14:57:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 202001 SWODY1 SPC AC 201958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST MON NOV 20 2006 VALID 202000Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SYNOPTIC PATTERN IN MID-UPPER LEVELS FEATURES HIGH-AMPLITUDE TROUGH OVER ERN CONUS...AND RIDGING FROM NRN MEX NEWD ACROSS UPPER MIDWEST AND UPPER MS VALLEY. SRN STREAM FLOW OVER SERN CONUS IS EXPECTED TO BEGIN CUTTING OFF BY END OF PERIOD AS STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER N-CENTRAL GULF AND SERN LA -- PIVOTS EWD AND PHASES WITH ANOTHER TROUGH OVER SRN APPALACHIANS. BY 21/12Z...RESULT SHOULD BE CLOSED CYCLONE COVERING GA...NERN GULF AND FL PANHANDLE. AS THIS OCCURS...SFC LOW ALREADY EVIDENT OFFSHORE SC IS EXPECTED TO DEEPEN IN PLACE. MEANWHILE...BROAD FETCH OF SWLY FLOW ALOFT WILL CONTINUE ACROSS MUCH OF W COAST AND NRN CONUS...W OF MEAN RIDGE. ...SERN CONUS... WRN EDGE OF LARGELY MARITIME TSTM POTENTIAL WILL BRUSH COASTAL AREAS OF SC/NC THROUGH REMAINDER PERIOD...IN ASSOCIATION WITH STRENGTHENING LOW LEVEL WAA AND FRONTAL ASCENT. FAVORABLY HIGH-THETAE SURFACE AIR MASS IN SERN SECTOR OF SFC CYCLONE -- AND OVER ENHANCED HEAT/MOISTURE FLUXES OF GULF STREAM -- WILL BE LIFTED ABOVE OFFSHORE WARM FRONTAL ZONE AND ADVECTED WWD IN ELEVATED WARM CONVEYOR. THIS WILL DESTABILIZE AIR MASS ENOUGH TO RESULT IN ELEVATED MUCAPES UP TO ABOUT 250 J/KG DURING OVERNIGHT HOURS. ...PACIFIC NW... EPISODES OF TSTMS ARE POSSIBLE OVER COASTAL/OFFSHORE WATERS...SOME OF WHICH MAY MOVE INLAND BEFORE WEAKENING. THIS WILL OCCUR IN RESPONSE TO PERIODS OF LOW-MIDLEVEL DESTABILIZATION IN AN ENVIRONMENT OF WEAK CINH AND MRGL LOW LEVEL THETAE...RESULTING IN MUCAPES 100-300 J/KG ALONG COAST. IN ADDITION...LOW LEVEL FRONTOGENETIC FORCING LATE TONIGHT MAY CONCENTRATE TSTM POTENTIAL ALONG ASSOCIATED AREA OF ENHANCED LIFT. ..EDWARDS.. 11/20/2006  From swody1 at goshenarc.org Tue Nov 21 00:32:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 20 Nov 2006 19:32:44 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210036 SWODY1 SPC AC 210033 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 PM CST MON NOV 20 2006 VALID 210100Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SERN ATLANTIC COAST... CLUSTERS OF TSTMS ARE ONGOING THIS EVENING OFF THE CAROLINA COASTS...LARGELY DRIVEN BY RESPONSE TO FRONTOGENESIS IN THE 850 MB LAYER /PER RUC OBJECTIVE FIELDS/. HEAT AND MOISTURE FLUXES ALONG THE GULF STREAM SHOULD MAINTAIN AT LEAST WEAK INSTABILITY OVERNIGHT INVOF OF THIS INTENSIFYING BOUNDARY AND ATTENDANT LOW LEVEL CIRCULATION /SITUATED APPROXIMATELY 100 NM SE CHS/. SOME OF THIS ACTIVITY COULD APPROACH THE COAST LATER TONIGHT AS PORTION OF BAROCLINIC ZONE N OF SURFACE LOW PIVOTS SLIGHTLY WWD. ADDITIONAL STORMS MAY DEVELOP SWD FROM ONGOING ACTIVITY TO JUST OFF THE GA COAST AS STRONG SHORT WAVE TROUGH NOW OVER THE FAR NERN GULF OF MEXICO TRANSLATES EWD AND INTERACTS WITH THE WEAKLY UNSTABLE ENVIRONMENT. ...WA/ORE COASTS... WATER VAPOR IMAGERY INDICATES NEXT UPSTREAM SHORT WAVE TROUGH NEAR 42N AND 129W...WHICH LATEST MODEL GUIDANCE TAKES ONTO THE COAST BY 21/12Z. 21/00Z UIL/SLE SOUNDINGS INDICATE RELATIVELY STEEP LAPSE RATES --7 C/KM-- IN THE LOWEST 3.5 KM AGL WITH VERY MARGINAL CONVECTIVE INSTABILITY. FURTHER STEEPENING OF LAPSE RATES IS FORECAST OVERNIGHT WITH THE APPROACH OF THIS SHORT WAVE TROUGH WITH SUFFICIENT INSTABILITY DEVELOPING FOR ISOLATED...EMBEDDED TSTMS ALONG THE COAST /SIMILAR TO WHAT IS BEING OBSERVED JUST AHEAD OF VORTICITY MAXIMUM NEAR 43.5N AND 127W AS OF 0030Z/. ..MEAD.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 05:24:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 00:24:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 210527 SWODY1 SPC AC 210525 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 PM CST MON NOV 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... INTENSE MID AND UPPER LOW EVOLVING OVER SRN GA/FL PNHDL INTO THE NERN GULF OF MEXICO WILL CONSTRICT SLIGHTLY AS IT SLOWLY SHIFTS EWD OFF THE FL ATLANTIC COAST. IN THE W...A BROAD BELT OF CYCLONIC FLOW WILL EXIST IN THE MID LEVELS FROM THE ERN PACIFIC INTO THE NRN ROCKIES. SHORT WAVE TROUGH EMBEDDED WITHIN THIS REGIME NOW APPROACHING THE WA/ORE COAST WILL TRANSLATE EWD INTO THE NRN ROCKIES BY TONIGHT WHILE NEXT UPSTREAM IMPULSE DIGS SEWD FROM THE GULF OF AK TO OFF THE PACIFIC NW COAST BY WEDNESDAY MORNING. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO FL UPPER LOW WILL REMAIN QUASI-STATIONARY OVER THE GULF STREAM WHILE GRADUALLY UNDERGOING OCCLUSION. WELL TO THE NW...LEE CYCLONE IS FORECAST TO INTENSIFY OVER ALBERTA INTO SASKATCHEWAN IN RESPONSE TO APPROACH OF LEAD SHORT WAVE TROUGH THROUGH THE NRN ROCKIES. LOW-LEVEL ONSHORE FLOW WILL CONCURRENTLY INCREASE ALONG THE PACIFIC NW COAST...IN WAKE OF BAROCLINIC ZONE INTENSIFYING FROM THE LOW OVER THE CANADIAN HIGH PLAINS SWWD INTO ERN ORE. ...SRN ATLANTIC COAST... LOW-LEVEL BAROCLINIC ZONE N AND NW OF SURFACE LOW IS EXPECTED TO REMAIN OVER THE SHELF WATERS WITH RESPONSE TO FRONTOGENESIS AND LOW-LEVEL WAA MAINTAINING ISOLATED/SCATTERED STORMS ALONG THIS BOUNDARY. FORECAST SOUNDINGS SUGGEST THAT ANY STORMS DEVELOPING ALONG THE IMMEDIATE COAST WILL LIKELY REMAIN ELEVATED AND BASED AROUND 850 MB WITHIN WEAKLY UNSTABLE ENVIRONMENT WITH MUCAPES OF AROUND 100 J/KG. ...NRN ROCKIES... INCREASED HEIGHT FALLS ASSOCIATED WITH SHORT WAVE TROUGH MOVING THROUGH WA/ORE ARE EXPECTED TO CONTRIBUTE TO STEEPENING LAPSE RATES AND DEVELOPMENT OF WEAK CONVECTIVE INSTABILITY LATER TODAY INTO TONIGHT. ISOLATED TSTMS EMBEDDED IN SHALLOWER CONVECTION WILL BECOME INCREASINGLY LIKELY AT THIS TIME ALONG STRENGTHENING LOW LEVEL BAROCLINIC ZONE THAT WILL STRETCH FROM WRN MT INTO ERN ORE. ...PACIFIC NW COAST... MOIST ONSHORE FLOW IN THE LOW LEVELS BENEATH COLD MID LEVEL TEMPERATURES OF AROUND -30 C AT 500 MB WILL RESULT IN RATHER STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY. IT APPEARS THE BEST POTENTIAL FOR ISOLATED TSTM ACTIVITY WILL EXIST THIS MORNING IN ASSOCIATION WITH LEAD SHORT WAVE TROUGH...AND TOWARD THE END OF THE PERIOD WEDNESDAY MORNING AS NEXT UPSTREAM SYSTEM APPROACHES FROM THE W. ..MEAD/BOTHWELL.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 12:40:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 07:40:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211244 SWODY1 SPC AC 211241 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0641 AM CST TUE NOV 21 2006 VALID 211300Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...PAC NW COAST INTO THE NRN SIERRAS AND NRN ROCKIES... 12Z SOUNDINGS AND EARLY MORNING LIGHTNING DETECTION NETWORK INDICATE ISOLATED THUNDERSTORMS WILL LIKELY CONTINUE THIS MORNING ALONG THE PAC NW COAST AND WITHIN BROAD MID LEVEL MOISTURE PLUME INTO THE NRN SIERRAS. STRONG MID/UPPER LEVEL TROUGH WILL PERSIST ALONG AND JUST OFF THE PAC NW COAST THROUGH THE PERIOD WITH SHORTWAVE TROUGH NOW APPROACHING THE COAST LIFTING ENEWD INTO THE NRN ROCKIES AS ANOTHER VORT MAX DIGS SSEWD OUT OF THE GULF OF AK. PERSISTENT ONSHORE FLOW AND STEEP LOW TO MID LEVEL LAPSE RATES SHOULD MAINTAIN ISOLATED THUNDERSTORMS ALONG AND WEST OF THE COASTAL RANGE IN WRN WA/ORE. ELSEWHERE...MOIST CONVECTION AND POSSIBLY ISOLATED THUNDERSTORMS SHOULD DEVELOP ALONG AND AHEAD OF SHORTWAVE TROUGH AND ASSOCIATED PAC COLD FRONT FORECAST TO OVERSPREAD THE NRN ROCKIES LATER TODAY AND TONIGHT. ...SERN U.S. COAST... INTENSE LOW SYSTEM WILL REMAIN IN PLACE JUST OFF THE GA/FL/SC COAST THROUGH THE PERIOD. DEEPER CONVERGENCE AND GREATER INSTABILITY WILL REMAIN OVER THE GULF STREAM AND SUPPORT SCATTERED THUNDERSTORMS JUST OFF THE COAST. HOWEVER...SUFFICIENT MID LEVEL COOLING IS EXPECTED TO SUSTAIN NARROW WEDGE OF ELEVATED INSTABILITY AND POTENTIAL FOR AN ISOLATED THUNDERSTORM OR TWO ACROSS COASTAL SC INTO ERN NC TODAY AND TONIGHT. ..EVANS.. 11/21/2006  From swody1 at goshenarc.org Tue Nov 21 16:16:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 11:16:50 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 211619 SWODY1 SPC AC 211617 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1017 AM CST TUE NOV 21 2006 VALID 211630Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AMPLIFIED UPPER AIR PATTERN OVER CENTRAL/ERN CONUS WILL CONTINUE THROUGH PERIOD...WITH PRONOUNCED RIDGING FROM NRN MEX NEWD ACROSS MID/UPPER MS VALLEY. DOWNSTREAM...ANOMALOUSLY DEEP CYCLONE ALOFT -- CHARACTERIZED BY 90M/12H 500 MB HEIGHT FALLS TO ITS S AT EYW -- IS FCST TO MEANDER SLOWLY ACROSS NRN FL TOWARD ATLANTIC WATERS OFFSHORE GA. AS THIS OCCURS...ASSOCIATED LOW LEVEL CYCLONE WILL PROCEED DEEPER INTO OCCLUSION PROCESS...BECOMING PROGRESSIVELY MORE VERTICALLY STACKED WITH RESPECT TO MID/UPPER VORTEX. FARTHER NW...SERIES OF SHORTWAVE TROUGHS WILL PIVOT EWD AND NEWD AROUND NERN PACIFIC UPPER LOW...FROM COASTAL WA/ORE NEWD ACROSS INTERIOR WA AND SRN BC. MAIN PERTURBATION -- INDICATED BY MOISTURE CHANNEL IMAGERY INVOF WA COAST AND JUST OFFSHORE ORE -- IS EXPECTED TO DEAMPLIFY AS IT MOVES INLAND THROUGH REMAINDER PERIOD. ASSOCIATED LOW LEVEL FRONT -- NOW EVIDENT FROM NRN CASCADES SSWWD ACROSS NWRN CA -- LIKEWISE SHOULD WEAKEN AS IT MOVES INLAND. THOUGH SEVERAL AREAS OF MRGL GEN TSTM POTENTIAL EXIST WITH THESE REGIMES...INSTABILITY WILL REMAIN TOO WEAK FOR ORGANIZED SVR POTENTIAL. ...NWRN CONUS... POTENTIAL LINGERS FOR ISOLATED TSTMS WITHIN PORTIONS OF LOW LEVEL WAA PLUME AND CORRESPONDING BELT OF LOW-MIDLEVEL MOISTURE TRANSPORT -- FROM NRN CA NEWD ACROSS NRN ROCKIES. AS SHORTWAVE TROUGH NOW NEAR COAST MOVES INLAND...FAVORABLE LARGE SCALE ASCENT AND TSTM POTENTIAL IN WARM CONVEYOR EACH SHOULD WEAKEN FROM SW-NE...ENDING OVER NRN CA AREA WITHIN NEXT 3-4 HOURS BUT PERSISTING EPISODICALLY OVER PORTIONS INTERIOR NW AND NRN ROCKIES INTO EARLY TONIGHT. MEANWHILE...RELATIVELY STEEP LAPSE RATES AND MINIMAL CINH WILL HELP TO SUPPORT RISK OF ISOLATED TO WIDELY SCATTERED...SHALLOW...POSTFRONTAL TSTMS ACROSS COASTAL AREAS OF WA/ORE. IN THIS REGIME...CHARACTERIZED BY 500 MB TEMPS TO AROUND -30 C...MUCAPES MAY REACH TO NEAR 300 J/KG WITH BUOYANCY VERTICALLY EXTENDING INTO FAVORABLE ICING LAYERS FOR LIGHTNING PRODUCTION. ...SRN ATLANTIC COASTAL REGION... AS DEEP-LAYER CYCLONE MEANDERS OFFSHORE GA COAST...LOW LEVEL FRONTAL FORCING AND WAA CONVEYOR WILL WRAP AROUND NRN/WRN SECTORS OF THIS SYSTEM. EXPECT FAVORABLE MOISTURE...ELEVATED INSTABILITY AND LIFT TO SUPPORT ISOLATED TSTMS OVER COASTAL AREAS...BECOMING MORE COMMON OFFSHORE WHERE OCEANIC HEAT FLUXES WILL CONTRIBUTE TO LOW LEVEL BUOYANCY. ..EDWARDS/GRAMS.. 11/21/2006 WWWW From swody1 at goshenarc.org Tue Nov 21 19:58:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 14:58:00 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 212000 SWODY1 SPC AC 211958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0158 PM CST TUE NOV 21 2006 VALID 212000Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...ERN CAROLINAS... MARINE FRONT SEEMS TO HAVE MOVED WWD TOWARD THE NC OUTER BANKS PER BUOY 41025 WHERE A WIND SHIFT TO ELY OCCURRED AND TEMPERATURE/DEW POINTS HAVE CLIMBED DURING THE PAST FEW HOURS. MAINTENANCE OF STRONG ISENTROPIC LIFT ON THE COLD SIDE OF THE CYCLONE SHOULD CONTINUE TO STRENGTHEN THE BAROCLINIC ZONE...PREVENTING THE MARINE BOUNDARY LAYER /MORE UNSTABLE ENVIRONMENT/ FROM REACHING THE OUTER BANKS. AS SUCH...NO ORGANIZED SEVERE WEATHER IS ANTICIPATED. BUT...SPORADIC TSTMS ARE LIKELY INLAND WITHIN THE ENHANCED MESOSCALE BANDS ALONG NWRN SIDE OF THE MATURING CYCLONE. SATL INDICATES THAT THE NEXT LOBE OF VORTICITY WILL ROTATE NWD INTO PRIMARILY ERN NC DURING THE EVENING. THIS WILL LIKELY ENHANCE THE MID-LEVEL FRONTOGENETIC RESPONSE AND TSTM PROBABILITIES. FURTHER DETAILS CAN BE FOUND IN NEWLY ISSUED MESOSCALE DISCUSSION 2229. ...PAC NW... CONSIDERABLE OPEN-CELL CUMULIFORM CLOUD TEXTURES ARE EVIDENT ON VSBL SATL IMAGERY OFFSHORE WA/ORE WITHIN CYCLONIC FLOW REGIME SITUATED ACROSS THE PAC NW. A FEW LIGHTNING STRIKES CONTINUE ALONG/W OF THE COASTAL RANGES AND THIS WILL LIKELY BE THE CASE THROUGH THIS EVENING. TSTM CHANCES SHOULD HAVE PEAKED AS SLIGHT WARMING OCCURS ALOFT AHEAD OF THE NEXT DISTURBANCE EXPECTED TO ARRIVE ONSHORE ON WED. OTHERWISE...ISOLD TSTMS MAY STILL BE POSSIBLE ACROSS THE NRN INTERMOUNTAIN WEST AHEAD OF A WEAK UPPER DISTURBANCE PASSING ACROSS THE REGION. ..RACY.. 11/21/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 00:42:11 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 21 Nov 2006 19:42:11 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220042 SWODY1 SPC AC 220039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 PM CST TUE NOV 21 2006 VALID 220100Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SRN ATLANTIC COAST... EVENING WATER VAPOR IMAGERY SHOWS ANOMALOUSLY INTENSE UPPER LOW CENTERED JUST OFF THE COAST OF NRN FL/GA WITH STRONG VORTICITY MAXIMUM ROTATING NNWWD AROUND THE ERN/NERN PERIPHERY OF THIS LOW. DEEP-LAYER FORCING FOR ASCENT...COMPRISED OF DPVA AND LOW-LEVEL WAA...ARE CONTRIBUTING TO EMBEDDED SCATTERED TSTMS FROM NEAR CRE TO OAJ AS OF 0000Z. THE MAJORITY OF THIS STORM ACTIVITY IS OCCURRING NEAR AND W OF LOW-LEVEL BAROCLINIC ZONE LOCATED JUST OFF THE OUTER BANKS WITHIN WEAKLY UNSTABLE ENVIRONMENT FOR ELEVATED PARCELS WITH MUCAPES OF 200-300 J/KG AS OBSERVED BY 22/00Z MHX SOUNDING. EXPECT THAT THE ONGOING LOW-LEVEL WAA WILL LIKELY CONTINUE TO BE THE PRIMARY FORCING MECHANISM TO MAINTAIN ISOLATED TO SCATTERED TSTMS OVERNIGHT MAINLY ALONG THE IMMEDIATE COAST. ...PACIFIC NW COAST TO NRN INTERMOUNTAIN REGION... ISOLATED TSTMS HAVE BEEN OBSERVED THIS AFTERNOON AND EARLY EVENING OVER CNTRL PARTS OF ID IN ASSOCIATION WITH LEAD SHORT WAVE TROUGH TRANSLATING THROUGH THE NRN ROCKIES. 22/00Z BOI SOUNDING SHOWS THAT STEEP LOW TO MID-LEVEL LAPSE RATES ARE LARGELY CONTRIBUTING TO POCKETS OF WEAK INSTABILITY /MUCAPES OF 200-300 J PER KG/. TSTMS SHOULD TEND TO DIMINISH LATER THIS EVENING AS BOUNDARY LAYER COOLS AND LAPSE RATES WEAKEN. FARTHER TO THE W...MOIST ONSHORE FLOW IN THE LOW-LEVELS COUPLED WITH COLD MID-LEVEL TEMPERATURES /-32 C AT 500 MB/ ARE CONTRIBUTING TO STEEP LAPSE RATES AND WEAK CONVECTIVE INSTABILITY /PER 22/00Z UIL/SLE SOUNDINGS/. WATER VAPOR IMAGERY SUGGESTS THAT NEXT UPSTREAM SHORT WAVE TROUGH IS ABOUT 100 NM W OF OTH WITH SOME OCEANIC LIGHTNING ACTIVITY OBSERVED WITH THIS FEATURE. EXPECT THAT THE THREAT OF ISOLATED...EMBEDDED TSTMS WILL INCREASE ALONG THE COAST WITH THE ARRIVAL OF THIS IMPULSE LATE TONIGHT. SOME SMALL HAIL/GRAUPEL MAY ACCOMPANY THE STRONGER CELLS...THOUGH THE MARGINAL INSTABILITY WILL LIMIT ANY SEVERE THREAT. ..MEAD.. 11/22/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 05:00:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 00:00:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 220503 SWODY1 SPC AC 220501 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 PM CST TUE NOV 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A STRONG AND COMPACT UPPER LOW WILL SLOWLY LIFT NEWD ALONG THE SERN COAST THROUGH THE PERIOD. AHEAD OF THIS FEATURE...A SFC FRONTAL BOUNDARY WILL REMAIN NEARLY STATIONARY ALONG THE OUTER BANKS NWD JUST OFF THE MID ATLANTIC COAST OF NJ. THE COMBINATION OF MODEST VERTICAL MOTION AND INSTABILITY SHOULD SUPPORT ISOLATED TO SCATTERED TSTMS ALONG AND EAST OF THIS BOUNDARY THROUGH TONIGHT. ELSEWHERE ACROSS THE NATION...WARM AND MILD CONDITIONS CAN BE EXPECTED ACROSS THE PLAINS STATES UNDER THE INFLUENCE OF MID/UPPER RIDGING. FURTHER WEST...ANOTHER STRONG UPPER TROUGH WILL MOVE INTO THE PAC NW DURING THE DAY AND INTO THE NRN ROCKIES WED NIGHT. THE COMBINATION OF MODEST UPSLOPE FLOW AND COLD MID LEVEL TEMPERATURES WILL SUPPORT ISOLATED TSTMS OVER WRN WA/ORE AS WELL AS PORTIONS OF THE NRN ROCKIES. ...OUTER BANKS OF NC... THE FRONTAL BOUNDARY PRESENTLY DRAPED ACROSS THE AREA WILL REMAIN NEARLY STATIONARY THROUGH DAYTIME HRS AS THE SFC/UPPER LOW MOVES SLOWLY NNEWD. COLDER MID LEVEL TEMPERATURES /-22 DEG C AT 500 MB/ LOCATED OFF THE EAST COAST OF FLA EARLY THIS MORNING WILL ROTATE ACROSS THE AREA DURING PEAK HEATING. SUFFICIENT INSTABILITY /MUCAPE FROM 500-750 J/KG/ COUPLED WITH LOW-MID LEVEL MODERATE VERTICAL MOTION EAST OF THE STATIONARY BOUNDARY SHOULD SUPPORT ISOLATED/SCT TSTM DEVELOPMENT. DESPITE THE PRESENCE OF A MID LEVEL DRY SLOT OVER THE REGION...THERE SHOULD BE WIDESPREAD LOW CLOUD COVER GIVEN THE MOIST LOW LEVEL WARM ADVECTION PROFILE. IF LESS LOW CLOUD COVER DEVELOPS THAN PRESENTLY EXPECTED...SLIGHTLY GREATER INSTABILITY /MUCAPES OVER 1000 J/KG/ WOULD BE REALIZED SUPPORTING MARGINALLY SVR HAIL IN THE STRONGEST TSTMS. GIVEN THE LOW CONFIDENCE IN THIS SCENARIO...WE WILL NOT INTRODUCE 5 PERCENT HAIL PROBS FOR THIS AREA ATTM. ...PAC NW/NRN ROCKIES... A LARGE POCKET OF COLD MID LEVEL TEMPERATURES...EVIDENT BY VIS/IR SATELLITE IMAGERY...EXISTED SEVERAL HUNDRED MILES OFF THE PAC NW COAST. THIS AREA WAS IN ASSOCIATION WITH A STRONG UPPER LOW/VORT LOBE ROTATING AROUND A BROADER UPPER TROUGH LOCATED OVER THE NERN PACIFIC. AS THIS VORT LOBE/TROUGH MOVES TOWARDS THE PAC NW COAST DURING THE AFTERNOON...SUFFICIENTLY STRONG UPSLOPE FLOW COMBINED WITH STEEPENING MID LEVEL LAPSE RATES /7.5-8 DEG C/KM/ WILL SUPPORT SCATTERED TSTMS OVER PORTIONS OF WRN ORE/WA. ALONG WITH LOW WBZ HEIGHTS...SUB-SVR SMALL HAIL/GRAUPEL IS POSSIBLE WITH THE STRONGEST TSTMS IN LOWER ELEVATIONS. DESPITE BEING AFTER DARK...ISOLATED TSTMS ARE ALSO POSSIBLE IN THE STRONG UPSLOPE REGIME/STEEP LAPSE RATE ENVIRONMENT JUST AHEAD OF UPPER TROUGH OVER PORTIONS OF THE NRN ROCKIES BETWEEN 23/06-12Z. ..CROSBIE/MEAD.. 11/22/2006 WWWW From swody1 at goshenarc.org Wed Nov 22 12:46:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 07:46:43 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221249 SWODY1 SPC AC 221247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST WED NOV 22 2006 VALID 221300Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...OUTER BANKS OF NC... SURFACE FRONTAL BOUNDARY PRESENTLY DRAPED ACROSS THE AREA WILL REMAIN NEARLY STATIONARY TODAY AS VERTICALLY STACKED LOW MOVES SLOWLY NNEWD. COLDER MID LEVEL TEMPERATURES /-22 DEG C AT 500 MB/ LOCATED OFF THE EAST COAST OF FL EARLY THIS MORNING WILL ROTATE ACROSS THE AREA DURING PEAK HEATING. SUFFICIENT INSTABILITY /MUCAPE FROM 500-750 J/KG/ COUPLED WITH LOW-MID LEVEL MODERATE VERTICAL MOTION EAST OF THE STATIONARY BOUNDARY SHOULD SUPPORT ISOLATED/SCT TSTM DEVELOPMENT...PRIMARILY JUST OFF THE CAROLINA AND MID ATLANTIC COAST. ...PAC NW/NRN ROCKIES... STRONG UPPER LOW/VORT LOBE ROTATING AROUND A BROADER UPPER TROUGH LOCATED OVER THE NERN PACIFIC WILL MOVE TOWARDS THE PAC NW COAST DURING THE AFTERNOON...AND APPROACH THE NRN ROCKIES LATER TONIGHT. ACCOMPANYING POCKET OF COLD MID LEVEL TEMPERATURES WILL SUPPORT STEEP LOW-MID LEVEL LAPSE RATES...MAINLY IN POST-FRONTAL REGIME...WHERE UPSLOPE FLOW AND MARGINAL INSTABILITY WILL REMAIN SUPPORTIVE OF A FEW THUNDERSTORMS NEAR THE WA/ORE COAST. INCREASING MOIST CONVECTION AND POSSIBLY EMBEDDED/ISOLATED TSTMS SHOULD DEVELOP IN STRONG UPSLOPE/STEEP LAPSE RATE REGIME JUST AHEAD OF UPPER TROUGH AND ASSOCIATED COLD FRONT OVER PORTIONS OF THE NRN ROCKIES OVERNIGHT. ..EVANS.. 11/22/2006  From swody1 at goshenarc.org Wed Nov 22 16:20:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 11:20:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221624 SWODY1 SPC AC 221621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1021 AM CST WED NOV 22 2006 VALID 221630Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...ERN NC TO DELMARVA... 16Z STREAMLINE ANALYSIS PLACES A BROAD SFC LOW OVER THE NC CAPES WITH THE PRIMARY MARINE FRONT STILL LOCATED 30-40 MILES OFFSHORE. THE LOW SHOULD CONSOLIDATE ALONG THIS FRONT EAST OF THE CAPES LATER TODAY AS THE NEXT LOBE OF VORTICITY...NOW EVIDENT IN WATER VAPOR IMAGERY OVER ECNTRL FL...ROTATES NNEWD. OLD DEFORMATION ZONE OVER THE FOOTHILLS OF VA...NC...SC SHOULD DIMINISH THIS AFTN...WITH A NEW LOW TO MID-LEVEL FRONTOGENETIC ZONE LIKELY EVOLVING THIS EVE/ OVERNIGHT FROM EXTREME ERN NC NWD TO NEAR THE DELMARVA COAST. MESOSCALE BANDS WITHIN THIS ZONE SHOULD STRENGTHEN AFTER 00Z AS STRONGER H5-H3 QVECTOR CONVERGENCE SHIFTS NWD COINCIDENT WITH MUCAPES UP TO A FEW HUNDRED J PER KG. STRONGER TSTMS SHOULD REMAIN OFFSHORE WHERE THE PRIMARY INSTABILITY AXIS WILL BE LOCATED. ...PAC NW TO THE NRN INTERMOUNTAIN WEST... HEALTHY SHORTWAVE TROUGH WAS LOCATED 200-300 NM OFF THE WA/ORE COAST THIS MORNING PER WATER VAPOR IMAGERY WITH CONSIDERABLE OPEN-CELL CUMULUS FIELD. EXTRAPOLATION SUGGESTS THAT THE CORE OF THE COLD AIR ASSOCD WITH THIS IMPULSE /AOB MINUS 30 DEG C/ WILL SPREAD ACROSS WA/ORE THIS EVE AND INTO THE NRN INTERMOUNTAIN WEST LATE TONIGHT. STEEPENING LAPSE RATES ALOFT COMBINED WITH AN INCREASING WLY COMPONENT TO THE LOW-LEVEL FLOW WILL BE SUFFICIENT FOR PARCELS TO REACH ICING LEVELS AND TSTMS WILL BE POSSIBLE ACROSS THE REGION. HIGHEST PROBABILITIES WILL BE ACROSS NWRN ORE/SWRN WA LATE THIS EVENING. OTHER TSTMS WILL BE POSSIBLE...BUT MORE ISOLD IN COVERAGE...ACROSS THE HIGHER TERRAIN OF ERN WA/ORE EWD INTO WRN MT BY 12Z THU. ..RACY/GRAMS.. 11/22/2006  From swody1 at goshenarc.org Wed Nov 22 19:55:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 14:55:30 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221958 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST WED NOV 22 2006 VALID 222000Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER LEVEL PATTERN SHIFT IS BEGINNING...AS EVIDENT IN NEWD EJECTION OF DEEP/OCCLUDED CYCLONE INVOF COAST...AND IN HEIGHT FALLS ACROSS PACIFIC NW REGION. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY BETWEEN 128W-132W OFFSHORE PACIFIC NW -- IS FCST TO MOVE INLAND DURING 23/00Z-23/03Z TIME FRAME. MEANWHILE...FARTHER SE...SW-NE ELONGATED SFC CYCLONE LOCATED JUST OFFSHORE SRN NC COAST IS FCST TO MOVE SLOWLY NEWD IN TANDEM WITH LOW ALOFT. AIR MASS BETWEEN TIDEWATER REGION AND PACIFIC NW WILL REMAIN TOO DRY AND/OR STABLE TO SUPPORT DEEP MOIST CONVECTION. ...NWRN CONUS... SYNOPTIC SCALE DESTABILIZATION AND COOLING ALOFT WILL INCREASE DURING NEXT FEW HOURS FROM W-E ACROSS WA/ORE...AS STRONGEST DPVA MOVES OVERHEAD PRIOR TO PASSAGE OF MID/UPPER LEVEL TROUGH. THIS SYSTEM IS RESPONSIBLE FOR EXTENSIVE AREA OF DISCRETE/CUMULIFORM CONVECTION OVER WATER...INCLUDING SCATTERED/SMALL CB. MODIFIED RAOBS AND RUC SOUNDINGS SUGGESTS WEAK MUCAPE OF 300 J/KG OR LESS IN MOST AREAS...BUT ALSO WEAK CINH AND STEEP LAPSE RATES...WITH SOME BUOYANCY EXTENDING INTO ICING LAYERS FAVORABLE FOR CG LIGHTNING PRODUCTION. ...TIDEWATER NC TO COASTAL NJ... MRGL/ELEVATED BUOYANCY...ASSOCIATED WITH LOW LEVEL WARM CONVEYOR...WILL SHIFT NWD AND WEAKEN THROUGH REMAINDER PERIOD. HOWEVER...FRONTOGENETIC FORCING NEAR COAST OR JUST OFFSHORE MAY PROVIDE ENHANCED LIFT IN SUPPORT OF POTENTIAL FOR ISOLATED/SPORADIC THUNDER FROM DELMARVA THROUGH COASTAL NJ. FARTHER S...ISOLATED TSTMS IN COLD CORE REGION OF SYSTEM -- LOCATED MAINLY OFFSHORE -- MAY AFFECT IMMEDIATE COASTAL ARAS NC THIS EVENING AND TONIGHT. HOWEVER...SWATH OF MIDLEVEL DRYING THAT HAS WRAPPED AROUND MUCH OF CYCLONE CORE MAY CONTINUE TO LIMIT OVERALL CONVECTIVE COVERAGE. ..EDWARDS.. 11/22/2006  From swody1 at goshenarc.org Thu Nov 23 00:36:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 19:36:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230039 SWODY1 SPC AC 230037 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CST WED NOV 22 2006 VALID 230100Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC COASTAL AREAS... IN RESPONSE TO THE PROGRESSION OF AN IMPULSE ROTATING AROUND ITS EASTERN/NORTHERN PERIPHERY...A MID-LEVEL CLOSED LOW HAS REDEVELOPED NORTHEASTWARD INTO AREAS OFF THE CAROLINA COAST...TO THE SOUTH/EAST OF WILMINGTON. ASSOCIATED MID-LEVEL COOLING HAS CONTRIBUTED TO DESTABILIZATION NEAR WAVE ALONG STALLED LOW-LEVEL BAROCLINIC ZONE ...SUPPORTING ONGOING AREA OF SCATTERED THUNDERSTORMS. THIS ACTIVITY MAY PERSIST INTO THE OVERNIGHT HOURS...AND LIKELY WILL BE SLOW TO SHIFT NORTHEAST OF THE NORTH CAROLINA/SOUTHEAST VIRGINIA COAST...AS UPPER SYSTEM REMAINS CUT-OFF FROM THE STRONGER WESTERLIES. ...PACIFIC NORTHWEST... SHORT WAVE TROUGH EMBEDDED WITHIN BELT OF STRONGER POLAR WESTERLIES IS JUST NOW BEGINNING TO SHIFT INTO COASTAL AREAS...AND IS PROGGED EAST OF THE CASCADES BY 23/12Z. MID-LEVEL COLD POOL ASSOCIATED WITH THIS FEATURE WILL OVERSPREAD MUCH OF THE NORTHWESTERN STATES BY DAYBREAK...LIKELY CONTRIBUTING TO SOME DESTABILIZATION AND CONVECTIVE POTENTIAL. HOWEVER...RISK FOR THUNDERSTORMS SEEMS LIKELY TO MOSTLY BE CONFINED TO COASTAL AREAS AND THE WESTERN SLOPES OF THE CASCADES...AS WEAK TO MODERATE MOIST ONSHORE FLOW DEVELOPS LATER THIS EVENING/OVERNIGHT. ..KERR.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 04:48:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 22 Nov 2006 23:48:41 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230451 SWODY1 SPC AC 230449 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1049 PM CST WED NOV 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... A SIGNIFICANT PROGRESSIVE SHORT WAVE TROUGH...EMBEDDED WITHIN THE STRONGER NORTHERN BRANCH OF THE POLAR WESTERLIES...IS FORECAST TO LIFT RAPIDLY EAST NORTHEAST OF THE NORTHERN INTERMOUNTAIN REGION... THROUGH THE CENTRAL CANADIAN/U.S. BORDER AREA BY 12Z FRIDAY. THIS IS EXPECTED TO OCCUR AS ANOTHER SHORT WAVE TROUGH MIGRATES INLAND ACROSS SOUTHERN BRITISH COLUMBIA AND WASHINGTON. MEANWHILE...A DOWNSTREAM RIDGE IS PROGGED TO SHIFT EAST OF THE MISSISSIPPI VALLEY...AND MODELS SUGGEST THIS WILL CONTRIBUTE TO THE NORTHEASTWARD ACCELERATION OF MID ATLANTIC COAST CLOSED LOW...OFF NORTH ATLANTIC COASTAL AREAS. IN THE WAKE OF THE EASTERN SYSTEM...LOW/MID-LEVEL RIDGING ...EXTENDING FROM THE UPPER OHIO VALLEY DEEP INTO THE WESTERN GULF OF MEXICO...WILL INHIBIT THE NORTHWARD RETURN OF A SLOWLY MODIFYING/MOISTENING WESTERN GULF BOUNDARY LAYER. AND...A DRY STABLY STRATIFIED ENVIRONMENT WILL PREVAIL ACROSS MOST AREAS EAST OF THE ROCKIES...WITH NEGLIGIBLE POTENTIAL FOR THUNDERSTORM ACTIVITY. SIMILARLY DRY AND STABLE CONDITIONS ACROSS MUCH OF THE WEST WILL ALSO MINIMIZE CONVECTIVE POTENTIAL. AN EXCEPTION MAY EXIST ACROSS PARTS OF THE PACIFIC NORTHWEST. ...PACIFIC NORTHWEST... MODELS SUGGEST THAT ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COASTAL AREAS. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..KERR.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 12:31:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 07:31:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231234 SWODY1 SPC AC 231232 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0632 AM CST THU NOV 23 2006 VALID 231300Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...MID ATLANTIC COAST INTO COASTAL NEW ENGLAND... EJECTING LOW PRESSURE SYSTEM WILL CONTINUE TO LIFT NWD ALONG THE EAST COAST TODAY WITH FEED OF WEAK INSTABILITY AND STEEPENING MID LEVEL LAPSE RATES MAINTAINING A FEW THUNDERSTORMS OVER COASTAL WATERS. 12Z SOUNDINGS AT WAL AND OKX BOTH INDICATE SLIVER OF CAPE BETWEEN ROUGHLY H8 AND H5. THOUGH INFLUX OF MOISTURE WILL SUSTAIN MODERATE TO HEAVY MOIST CONVECTION INTO THE MID ATLANTIC AND SRN NEW ENGLAND AHEAD OF THIS SYSTEM...APPEARS THUNDERSTORM POTENTIAL WILL BE QUITE WEAK AWAY FROM THE COAST. ...PACIFIC NORTHWEST... ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COAST....IN WAKE OF SHORTWAVE TROUGH NOW MOVING ACROSS WRN WA. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..EVANS/CROSBIE.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 13:42:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 08:42:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231345 SWODY1 SPC AC 231343 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0743 AM CST THU NOV 23 2006 VALID 231300Z - 241200Z ...NO SVR TSTM AREAS FORECAST... CORRECTED GRAPHIC ...MID ATLANTIC COAST INTO COASTAL NEW ENGLAND... EJECTING LOW PRESSURE SYSTEM WILL CONTINUE TO LIFT NWD ALONG THE EAST COAST TODAY WITH FEED OF WEAK INSTABILITY AND STEEPENING MID LEVEL LAPSE RATES MAINTAINING A FEW THUNDERSTORMS OVER COASTAL WATERS. 12Z SOUNDINGS AT WAL AND OKX BOTH INDICATE SLIVER OF CAPE BETWEEN ROUGHLY H8 AND H5. THOUGH INFLUX OF MOISTURE WILL SUSTAIN MODERATE TO HEAVY MOIST CONVECTION INTO THE MID ATLANTIC AND SRN NEW ENGLAND AHEAD OF THIS SYSTEM...APPEARS THUNDERSTORM POTENTIAL WILL BE QUITE WEAK AWAY FROM THE COAST. ...PACIFIC NORTHWEST... ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COAST....IN WAKE OF SHORTWAVE TROUGH NOW MOVING ACROSS WRN WA. THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS. POTENTIAL IS EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID LEVELS CONTINUE TO GRADUALLY WARM. ..EVANS.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 15:41:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 10:41:14 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231544 SWODY1 SPC AC 231542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0942 AM CST THU NOV 23 2006 VALID 231630Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...PAC NW AND NRN ROCKIES TODAY... A PRONOUNCED MID LEVEL SHORTWAVE TROUGH AND ASSOCIATED BAROCLINIC ZONE WILL MOVE EWD OVER THE NRN ROCKIES TODAY...TO THE NRN PLAINS LATE TONIGHT. AN ISOLATED LIGHTNING STRIKE OR TWO COULD ACCOMPANY SHALLOW CONVECTION ALONG THE COLD FRONT ACROSS ERN ID/SW MT/NW WY WHERE RELATIVELY STEEP LAPSE COINCIDE WITH ASCENT ALONG THE FRONT...THOUGH VERY MARGINAL INSTABILITY WILL LIMIT THE OVERALL TSTM THREAT. OTHERWISE...A SECOND TROUGH WILL MOVE EWD OVER WA TODAY INTO TONIGHT. COLD MID LEVEL TEMPERATURES /-34 C AT 500 MB/ AND 7-8 C/KM THROUGH MUCH OF THE LOWEST 6 KM SHOULD REMAIN SUFFICIENT FOR ISOLATED THUNDERSTORMS WITHIN THE BROAD AREA OF CONVECTION NEAR AND DOWNSTREAM FROM THE MID LEVEL WAVE AXIS. ...SE NEW ENGLAND TODAY... A CLOSED LOW JUST OFF THE MID ATLANTIC COAST WILL MOVE NEWD AND LIKELY REMAIN JUST SE OF THE NEW ENGLAND COAST. SOME WEAK ELEVATED CONVECTION MAY OCCUR WITHIN THE BROADER RAIN SHIELD TODAY ACROSS SE NEW ENGLAND...BUT THE MORE SUBSTANTIAL INSTABILITY AND THUNDERSTORM THREAT WILL LIKELY REMAIN OFFSHORE. ..THOMPSON/GRAMS.. 11/23/2006  From swody1 at goshenarc.org Thu Nov 23 19:55:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 14:55:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231958 SWODY1 SPC AC 231955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST THU NOV 23 2006 VALID 232000Z - 241200Z ...NO SVR TSTM AREAS FORECAST... LATEST WATER VAPOR IMAGERY SHOWS TWO UPPER-LEVEL TROUGHS IN PLACE ACROSS THE CONUS. THE FIRST TROUGH IS ASSOCIATED WITH A CLOSED LOW LOCATED JUST OFF THE COAST OF MARYLAND. STRONG ASCENT AND COLD AIR ALOFT WITH THE UPPER-LOW MAY BE ENOUGH TO SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT MAINLY IN THE COASTAL WATERS OFF OF SRN NEW ENGLAND. THE SECOND UPPER TROUGH EXTENDS WWD FROM THE NRN HIGH PLAINS INTO THE PACIFIC NORTHWEST. A FEW THUNDERSTORMS MAY FORM ALONG THE COASTAL SECTIONS OF WA THIS EVENING AS A SECONDARY UPPER-LEVEL IMPULSE MOVES INLAND. NO SEVERE THREAT IS ANTICIPATED ACROSS THE CONUS THROUGH THE DAY 1 PERIOD. ..BROYLES.. 11/23/2006  From swody1 at goshenarc.org Fri Nov 24 00:47:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 19:47:13 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240050 SWODY1 SPC AC 240047 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 PM CST THU NOV 23 2006 VALID 240100Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...NORTH CENTRAL STATES... ISOLATED...SHORT-LIVED WEAK THUNDERSTORM ACTIVITY HAS BEEN EVIDENT ACROSS THE NORTH CENTRAL ROCKIES INTO THE NORTHERN HIGH PLAINS... IN ASSOCIATION WITH INITIAL SHORT WAVE TROUGH EMANATING FROM THE NORTHEAST PACIFIC. OROGRAPHY AND HEATING IN THE LEE OF THE HIGHER TERRAIN HAVE CONTRIBUTED TO DESTABILIZATION BENEATH LEADING EDGE OF COLD MID-LEVEL AIR MASS ACCOMPANYING UPPER SYSTEM. AS THIS FEATURE CONTINUES TO PIVOT DEEPER INTO THE PLAINS AND UPPER MISSISSIPPI VALLEY TONIGHT...SPORADIC THUNDERSTORM ACTIVITY SHOULD DIMINISH. ...PACIFIC NORTHWEST COAST... THE EXIT REGION OF A BROADLY CYCLONIC MID/UPPER JET STREAK CONTINUES TO NOSE INTO THE NORTHERN CASCADES. THIS...IN CONJUNCTION WITH 30 TO 40 KT 850 MB ONSHORE FLOW...IS CONTRIBUTING TO DESTABILIZATION AND WEAK CONVECTIVE DEVELOPMENT...INCLUDING A SCATTERING OF THUNDERSTORMS ACROSS AREAS WEST OF THE WASHINGTON/NORTHERN OREGON CASCADES. AS THE UPPER SYSTEM PROGRESSES INLAND THIS EVENING...POTENTIAL FOR THUNDERSTORMS WILL DIMINISH...AS LOW-LEVEL ONSHORE/UPSLOPE FLOW WEAKENS...AND MID-LEVELS GRADUALLY WARM. THIS MAY BE SLOWEST TO OCCUR ACROSS AREAS NEAR/WEST OF PUGET SOUND...BUT THREAT IS EXPECTED TO END IN AREAS TO THE SOUTH BY 06Z. ...NORTH ATLANTIC COAST... THE CLOSED LOW ACCELERATING NORTHEAST OF THE MID ATLANTIC COAST IS PROGGED TO TURN MORE TO THE EAST AS IT APPROACHES THE SOUTHERN NEW ENGLAND COAST...DUE TO THE INFLUENCE OF A PROGRESSIVE SHORT WAVE IMPULSE IN THE NORTHERN STREAM. AND...IT APPEARS MOST LIKELY THAT ANY THUNDERSTORM ACTIVITY NEAR WEAKENING MID-LEVEL CIRCULATION SHOULD PASS TO THE SOUTHEAST OF CAPE COD. ..KERR.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 04:40:27 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 23 Nov 2006 23:40:27 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240443 SWODY1 SPC AC 240440 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1040 PM CST THU NOV 23 2006 VALID 241200Z - 251200Z ...NO TSTM AREAS FORECAST... MODELS SUGGEST THAT THE POLAR WESTERLIES WILL REMAIN SPLIT INTO A COUPLE OF DISTINCT STRONGER BELTS THROUGH THIS FORECAST PERIOD. BUT...BROAD UPPER TROUGHING IS PROGGED TO CONTINUE TO EVOLVE FROM THE EASTERN PACIFIC THROUGH THE PLAINS AND UPPER MISSISSIPPI VALLEY...WHILE A DOWNSTREAM RIDGE SHIFTS EAST OF THE MISSISSIPPI VALLEY INTO THE EASTERN STATES. A STRONG JET STREAK IN THE BASE OF THE UPPER TROUGH...ASSOCIATED WITH THE PHASING OF THE SOUTHERN BRANCH OF THE POLAR WESTERLIES AND THE SUBTROPICAL STREAM...IS PROGGED TO NOSE EAST OF THE SOUTHERN U.S./NORTHERN MEXICAN PLATEAU REGION INTO THE SOUTHERN PLAINS. THIS WILL PROBABLY CONTRIBUTE TO AN AREA OF BROAD/WEAK LARGE-SCALE ASCENT FROM PARTS OF THE SOUTH CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY DURING THE LATTER PART OF THE PERIOD. HOWEVER...IN THE WAKE OF THE CLOSED LOW NOW ACCELERATING AWAY FROM ATLANTIC COASTAL AREAS...THE BOUNDARY LAYER OVER THE GULF OF MEXICO IS ONLY SLOWLY BEGINNING TO MODIFY/MOISTEN. WHILE A SOUTHERLY LOW-LEVEL FLOW WILL BEGIN TO DEVELOP ACROSS THE SOUTH CENTRAL STATES AS A LOW-LEVEL RIDGE RETREATS TOWARD THE ATLANTIC SEABOARD...POTENTIAL FOR THUNDERSTORMS APPEARS NEGLIGIBLE ACROSS THE CENTRAL STATES...AND THE REMAINDER OF THE U.S...THROUGH AT LEAST 12Z SATURDAY. ..KERR.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 12:49:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 07:49:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241252 SWODY1 SPC AC 241250 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0650 AM CST FRI NOV 24 2006 VALID 241300Z - 251200Z ...NO TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL CONTINUE TO EVOLVE ACROSS THE WESTERN UNITED STATES AND EASTERN PACIFIC TODAY. GENERALLY DRY/STABLE CONDITIONS ARE EXPECTED TO PRECLUDE THUNDERSTORMS OVER THE CONTIGUOUS U.S. DURING THIS FORECAST PERIOD. ISOLATED LIGHTNING STRIKES MAY OCCUR OFF THE WA AND FL COASTS...BUT THREATS IN THESE AREAS SHOULD ALSO REMAIN RATHER LOW. ..HART.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 16:16:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 11:16:10 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241618 SWODY1 SPC AC 241616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1016 AM CST FRI NOV 24 2006 VALID 241630Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/DISCUSSION... NO THREAT FOR SEVERE WEATHER TODAY WITH LITTLE OR NO AVAILABLE INSTABILITY FOR THUNDERSTORMS. A RIDGE ACROSS THE ERN CONUS AND SURFACE HIGH PRESSURE WILL KEEP CONDITIONS THERE VERY DRY. MEAGER MOISTURE RETURN WILL OCCUR INTO TX AROUND WRN EDGE OF THIS HIGH...AHEAD OF WEAK SRN STREAM TROUGH ACROSS THE WEST. RELATIVELY COOL TEMPERATURES ALOFT EXIST WITH THIS TROUGH ACROSS MUCH OF THE WEST...HOWEVER...PRECIPITABLE WATER VALUES WILL REMAIN LOW AND GENERALLY UNDER 0.33 IN. FARTHER N...A STRONGER NRN STREAM JET AND TEMPERATURE GRADIENT ALOFT WILL ALLOW FOR STEEP LAPSE RATES...BUT INSTABILITY WILL REMAIN LOW HERE AS WELL WITH ONLY A VERY LOW PROBABILITY OF A LIGHTNING STRIKE COASTAL WA. ..JEWELL/HALES.. 11/24/2006  From swody1 at goshenarc.org Fri Nov 24 19:46:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 14:46:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241949 SWODY1 SPC AC 241947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CST FRI NOV 24 2006 VALID 242000Z - 251200Z ...NO SVR TSTM AREAS FORECAST... A BROAD UPPER-LEVEL TROUGH OVER THE WRN U.S. WILL REMAIN IN PLACE TODAY AND TONIGHT. A SHORTWAVE TROUGH IS FORECAST TO MOVE EWD INTO THE PACIFIC NORTHWEST THIS EVENING. STRONG LARGE-SCALE ASCENT AND COLD TEMPS ALOFT ASSOCIATED WITH THE SHORTWAVE TROUGH MAY RESULT IN THE DEVELOPMENT OF ISOLATED THUNDERSTORMS OFF THE COAST OF WASHINGTON TONIGHT. OTHERWISE...NO CONVECTION IS EXPECTED ACROSS THE CONUS. ..BROYLES.. 11/24/2006  From swody1 at goshenarc.org Sat Nov 25 00:24:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 19:24:28 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250027 SWODY1 SPC AC 250024 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0624 PM CST FRI NOV 24 2006 VALID 250100Z - 251200Z ...NO TSTM AREAS FORECAST... A LARGE-SCALE UPPER TROUGH CONTINUES TO EVOLVE ACROSS THE EASTERN PACIFIC INTO THE PLAINS/UPPER MISSISSIPPI VALLEY...BUT THE FLOW REGIME BETWEEN SPLIT BELTS OF POLAR WESTERLIES TO THE EAST OF THE TROUGH AXIS REMAINS CONFLUENT. AND...SOUTHERN STREAM IMPULSE LIKELY WILL WEAKEN AS IT BEGINS TO LIFT NORTHEAST OF THE FOUR CORNERS STATES LATER TONIGHT. AN ELONGATED SURFACE RIDGE EXTENDING FROM THE EASTERN CANADIAN PROVINCES INTO GULF OF MEXICO HAS INHIBITED THE MODIFICATION OF THE BOUNDARY LAYER OVER THE GULF OF MEXICO...WHERE SURFACE DEW POINTS HAVE REMAINED MORE OR LESS STEADY IN THE 50S DURING THE PAST 24 HOURS. WITH LITTLE CHANGE ANTICIPATED IN THE SHORT TERM... SUBSTANTIAL RETURN FLOW OF MOISTURE INTO THE CENTRAL STATES APPEARS UNLIKELY THROUGH THE REMAINDER OF THIS PERIOD AND BEYOND. ACROSS THE PACIFIC NORTHWEST...COLDER MID-LEVEL ENVIRONMENT ASSOCIATED WITH THE NORTHERN STREAM APPEARS LIKELY TO REMAIN MOSTLY INLAND OR NORTH OF THE CANADIAN/U.S. BORDER. AND...WITH ONSHORE LOW-LEVEL/UPSLOPE FLOW REMAINING WEAK INTO SATURDAY...POTENTIAL FOR THUNDERSTORMS APPEARS NEGLIGIBLE. ..KERR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 04:33:49 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 24 Nov 2006 23:33:49 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250436 SWODY1 SPC AC 250434 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1034 PM CST FRI NOV 24 2006 VALID 251200Z - 261200Z ...NO TSTM AREAS FORECAST... A CYCLONIC UPPER FLOW CONTINUES TO EVOLVE FROM THE EASTERN PACIFIC THROUGH THE PLAINS AND UPPER MISSISSIPPI VALLEY REGION. MODELS INDICATE THAT THIS REGIME WILL REMAIN COMPRISED OF A COUPLE OF DISTINCT STRONGER BELTS...BUT THE PATTERN IS FORECAST TO BEGIN AMPLIFYING TOWARD THE END OF THE FORECAST PERIOD. THE MOST SIGNIFICANT EMBEDDED SHORT WAVE IMPULSES APPEAR LIKELY TO BE DIGGING IN THE SOUTHERN BRANCH OF THE POLAR WESTERLIES...ONE OFF THE PACIFIC NORTHWEST COAST...THE OTHER INTO THE BASE OF AN IN PHASE SOUTHERN BRANCH/SUBTROPICAL STREAM TROUGH ACROSS BAJA. FARTHER EAST...A MID-LEVEL SHORT WAVE TROUGH...EMBEDDED WITHIN THE NORTHERN STREAM...IS PROGGED TO SHIFT EAST OF THE NORTHERN INTERMOUNTAIN REGION INTO THE NORTHERN PLAINS BY 12Z SUNDAY. MEANWHILE...A COUPLE OF ADDITIONAL SOUTHERN BRANCH IMPULSES ARE FORECAST TO ACCELERATE NORTHEASTWARD AND WEAKEN WITHIN CONFLUENT REGIME EAST OF BROADER SCALE TROUGH AXIS...INTO UPPER RIDGE OVER THE EASTERN STATES. THE INCREASINGLY SHEARED LEAD IMPULSE IS PROGGED TO LIFT ACROSS THE CENTRAL PLAINS AND MID MISSOURI VALLEY INTO THE UPPER GREAT LAKES REGION...WHILE THE UPSTREAM SYSTEM LIFTS ACROSS THE LOWER COLORADO VALLEY INTO THE FOUR CORNERS REGION. ...EAST OF THE ROCKIES... MOISTENING OF THE BOUNDARY LAYER OVER THE WESTERN GULF OF MEXICO HAS BEEN INHIBITED BY AN ELONGATED SURFACE RIDGE EXTENDING FROM THE ST. LAWRENCE VALLEY INTO THE GULF OF MEXICO. WHILE A MORE RAPID MODIFICATION MAY BEGIN TO OCCUR DURING THIS PERIOD...A SIGNIFICANT RETURN FLOW OF MOISTURE INTO THE CENTRAL STATES APPEARS UNLIKELY TO OCCUR. ISENTROPIC ASCENT OF AN AIR MASS CHARACTERIZED BY 40S/LOWER 50S SURFACE DEW POINTS COULD EVENTUALLY SATURATE LOWER LEVELS TO THE WEST OF SURFACE RIDGE...ACROSS PARTS OF THE MID MISSOURI VALLEY INTO THE LOWER GREAT LAKES...TOWARD THE END OF THE PERIOD. HOWEVER...MODEL FORECAST SOUNDINGS SUGGEST THAT AN INITIALLY WARM AND DRY LOWER/MID TROPOSPHERE WILL PROBABLY INHIBIT DEEP CONVECTIVE DEVELOPMENT THROUGH AT LEAST 12Z SUNDAY. ...WEST OF ROCKIES... SOME MOISTENING IS OCCURRING ACROSS THE FOUR CORNERS WITH INITIAL SOUTHERN BRANCH SHORT WAVE TROUGH. AND...UPSTREAM SYSTEM MAY REMAIN VIGOROUS ENOUGH TO SUPPORT SIGNIFICANT UPWARD VERTICAL MOTION. HOWEVER...THIS DOES NOT LOOK LIKELY TO SPREAD INTO THE MORE FAVORABLE OROGRAPHY OF THE FOUR CORNERS REGION UNTIL AFTER SUNSET...WHICH WILL PROBABLY MINIMIZE POTENTIAL FOR THUNDERSTORM ACTIVITY. FARTHER NORTH...HEATING ACROSS THE NORTHERN ROCKIES WILL CONTRIBUTE TO AT LEAST MARGINAL DESTABILIZATION BENEATH VERY COLD MID-LEVEL AIR MASS ASSOCIATED WITH THE NORTHERN BRANCH SHORT WAVE TROUGH. HOWEVER...SOUNDINGS ACROSS THESE AREAS ARE FORECAST TO REMAIN LARGELY BELOW FREEZING. WHILE SCATTERED LOW-TOPPED CONVECTION IS PROBABLE...THUNDERSTORM ACTIVITY...IF ANY...SEEMS LIKELY TO BE VERY ISOLATED OR SPARSE IN COVERAGE. ..KERR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 12:33:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 07:33:06 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251235 SWODY1 SPC AC 251233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0633 AM CST SAT NOV 25 2006 VALID 251300Z - 261200Z ...NO TSTM AREAS FORECAST... MORNING WATER VAPOR LOOP SHOWS SEVERAL SHORTWAVE TROUGHS MOVING ACROSS THE WESTERN STATES. DESPITE LOCAL FORCING FOR VERTICAL MOTION IMMEDIATELY AHEAD OF THESE FEATURES...RELATIVELY DRY/STABLE CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE UNITED STATES AGAIN TODAY. THIS IS EXPECTED TO PRECLUDE ORGANIZED THUNDERSTORMS. THERE IS...HOWEVER...ONE AREA TO BE MONITORED. ...WESTERN CO THIS EVENING... UPPER VORT MAX CURRENTLY APPROACHING THE LA BASIN IS FORECAST TO MOVE EASTWARD AND INTO THE FOUR CORNERS REGION BY THIS EVENING. MODEL GUIDANCE SUGGESTS THAT AIR MASS AHEAD OF SYSTEM IS CHARACTERIZED BY RELATIVELY STEEP LAPSE RATES...BUT VERY LITTLE LOW/MID LEVEL MOISTURE. LIFT AHEAD OF TROUGH...COUPLED WITH OROGRAPHIC EFFECTS...MAY BE SUFFICIENT FOR SCATTERED SHOWERS AND ISOLATED LIGHTNING STRIKES AFTER DARK ACROSS WESTERN CO. HOWEVER...DEEP CONVECTIVE THREAT APPEARS TOO MARGINAL TO OUTLOOK AT THIS TIME. ..HART/TAYLOR.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 16:29:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 11:29:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251632 SWODY1 SPC AC 251629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1029 AM CST SAT NOV 25 2006 VALID 251630Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/DISCUSSION... MDT SWLY FLOW WITHIN BROAD SRN STREAM JET WILL REMAIN SITUATED FROM NRN MX ACROSS THE CNTRL PLAINS AND INTO THE GREAT LAKES WITH NRN STREAM JET ALONG THE U.S./CANADIAN BORDER. VERY COOL AIR ALOFT WILL EXIST OVER MUCH OF THE NRN AND WRN CONUS WHICH WILL RESULT IN CONDITIONAL THREAT OF ISOLATED THUNDERSTORMS MAINLY ACROSS SRN IA AND NRN MO WITH ELEVATED MOISTURE RETURN. ...NRN MO/SRN IA/ERN NEB/KS... MOIST PLUME IS IN PLACE WITH PRECIPITABLE WATER VALUES OF 0.50-0.75. CONTINUED ELEVATED WARM ADVECTION ALONG WITH RELATIVELY STEEP MID LVL LAPSE RATES MAY ALLOW FOR A FEW LIGHTNING STRIKES AS WEAK UPPER LVL SHORTWAVE TROUGH NOW EMERGING INTO WRN KS CONTINUES NEWD...AND LOW LEVEL WARM ADVECTION AROUND 850 MB PERSISTS. ..JEWELL/HALES.. 11/25/2006  From swody1 at goshenarc.org Sat Nov 25 19:44:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 14:44:33 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251947 SWODY1 SPC AC 251944 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0144 PM CST SAT NOV 25 2006 VALID 252000Z - 261200Z ...NO SVR TSTM AREAS FORECAST... SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE CNTRL AND ERN UNITED STATES. A COLD FRONT WILL MOVE SLOWLY SWD ACROSS THE CNTRL PLAINS AND UPPER MIDWEST TONIGHT. A FEW THUNDERSTORMS MAY DEVELOP LATE IN THE PERIOD ALONG THE BOUNDARY AS THE LOW-LEVEL JET BECOMES ENHANCED LATE TONIGHT. NO SEVERE THUNDERSTORMS SHOULD OCCUR WITH THE ACTIVITY. ..BROYLES.. 11/25/2006  From swody1 at goshenarc.org Sun Nov 26 00:09:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 25 Nov 2006 19:09:45 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260012 SWODY1 SPC AC 260010 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0610 PM CST SAT NOV 25 2006 VALID 260100Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SERN NEB/NERN KS/NRN MO/CENTRAL-SRN IA... A COUPLE OF SHORT WAVE TROUGHS WILL TRAVERSE NEWD ACROSS THE CENTRAL/SRN PLAINS TO THE GREAT LAKES REGION WITHIN SUBTROPICAL STREAM ALONG THE ERN PERIPHERY OF WRN U.S. LONG WAVE TROUGH. A SURFACE BOUNDARY EXTENDING FROM NRN KS TO ALONG THE MO/IA BORDER INTO SRN WI SHOULD CONTINUE TO MOVE SLOWLY NWD TONIGHT...AS A COLD FRONT SPREADS SEWD INTO THE UPPER MS VALLEY AND NEB. WATER VAPOR IMAGERY INDICATED A LEAD SHORT WAVE TROUGH TRACKING ACROSS NERN KS/SRN IA AT THIS TIME...WITH THIS FEATURE EXPECTED TO DEPART THE DAY 1 GENERAL TSTM OUTLOOK AREA THIS EVENING. ASCENT WITH THIS FEATURE HAS AIDED IN MOISTENING THE MID LEVELS AS SHOWN BY CLOUDS ACROSS THIS AREA. THIS MOISTENING COMBINED WITH ASCENT AHEAD OF NEXT UPSTREAM SPEED MAX/SHORT WAVE TROUGH...NOW LOCATED OVER SRN ROCKIES/HIGH PLAINS...AND WAA ALONG NOSE OF STRENGTHENING SWLY LLJ MAY SUPPORT CONVECTION AND A FEW LIGHTNING STRIKES THIS FORECAST PERIOD. THIS ACTIVITY...THOUGH LIKELY SPARSE...SHOULD PRIMARILY BE LOCATED ALONG/N OF RETREATING SURFACE BOUNDARY FROM NERN KS INTO IA. ..PETERS.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 05:29:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 00:29:17 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260531 SWODY1 SPC AC 260530 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 PM CST SAT NOV 25 2006 VALID 261200Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE SCALE UPPER TROUGH LOCATED WEST OF THE ROCKIES IS EXPECTED TO AMPLIFY THIS FORECAST PERIOD AS VORTEX OVER BRITISH COLUMBIA MOVES SWD TOWARD PACIFIC NW AND DEEPENS. AS THIS PROCESS OCCURS...PACIFIC SHORT WAVE TROUGH...CURRENTLY LOCATED NEAR 49N 139W PER WATER VAPOR IMAGERY...WILL DIG SSEWD REACHING SRN CA/GREAT BASIN BY 12Z MONDAY. DOWNSTREAM SHORT WAVE TROUGH TRACKING NEWD FROM FOUR CORNERS REGION TO THE CENTRAL PLAINS AND MID MO VALLEY WILL LIKELY DE-AMPLIFY AS IT APPROACHES REGION OF HEIGHT RISES/RIDGING ACROSS THE CENTRAL STATES. ...PACIFIC NW COAST SWD ALONG THE NRN CA COAST... STRONG HEIGHT FALLS ARE EXPECTED ACROSS THIS REGION AS UPPER VORTEX DEEPENS DURING THE FORECAST PERIOD. INITIAL THREAT FOR TSTMS SHOULD BE AS ASCENT ASSOCIATED WITH PACIFIC SHORT WAVE TROUGH/SURFACE FRONT SPREADS INLAND ALONG THE ORE TO NRN CA COAST THIS MORNING AND AFTERNOON. ADDITIONAL TSTMS WILL BE LIKELY OFFSHORE TO ALONG THE PAC NW COAST BY THIS EVENING WITHIN MOIST...POST-FRONTAL ONSHORE FLOW REGIME LOCATED BENEATH VERY COLD MID LEVEL TEMPERATURES /-30 TO -34 C AT 500 MB/. ...IA/FAR SRN MN/SWRN WI SWWD TO ERN NEB/NERN KS... IN THE LOW LEVELS...SURFACE BOUNDARY EXPECTED TO EXTEND FROM NRN KS ENEWD INTO SRN IA AND SRN WI SHOULD REMAIN NEARLY STATIONARY TODAY...AS A COLD FRONT...INITIALLY EXTENDING FROM NRN NEB TO NRN WI...MOVES SWD MERGING WITH THE SRN BOUNDARY. LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NNEWD WITH SURFACE DEWPOINTS IN THE LOWER 50S REACHING SERN NEB TO SRN IA/SRN WI BY LATE THIS AFTERNOON. ALTHOUGH THE FOUR CORNERS TROUGH WILL BE DE-AMPLIFYING AS IT APPROACHES THE CENTRAL PLAINS TO MID MO VALLEY TONIGHT...PLUME OF STEEP MID LEVEL LAPSE RATES /7+ C/KM/ WILL BE ADVECTED DOWNSTREAM AHEAD OF THIS TROUGH AND ATOP NRN EXTENT OF MOISTURE RETURN. THIS WILL AID IN WEAK DESTABILIZATION. DESPITE WEAK UPPER FORCING THIS EVENING AND OVERNIGHT WITH THE DAMPENING TROUGH...INCREASING LOW LEVEL WAA SHOULD SUPPORT AN AREA OF TSTMS FROM ERN NEB/NERN KS ACROSS IA/FAR SRN MN AND POTENTIALLY SWRN WI. SMALL HAIL COULD ACCOMPANY THE STRONGER STORMS...THOUGH THE MARGINAL INSTABILITY SHOULD PRECLUDE ANY SEVERE THREAT. ..PETERS/TAYLOR.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 12:43:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 07:43:29 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261245 SWODY1 SPC AC 261242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0642 AM CST SUN NOV 26 2006 VALID 261300Z - 271200Z ...NO SVR TSTM AREAS FORECAST... BROAD UPPER TROUGH WILL REMAIN OVER THE WESTERN AND CENTRAL STATES TODAY...WITH RIDGING MAINTAINING CONTROL OVER THE SOUTHEAST REGION. TWO AREAS APPEAR TO HAVE A THREAT OF ISOLATED-SCATTERED THUNDERSTORMS TODAY: THE MIDWEST STATES AND THE PACIFIC NORTHWEST COAST. ...CENTRAL PLAINS INTO MIDWEST... MID LEVEL VORT MAX CURRENTLY OVER WESTERN CO HAS RESULTED IN ISOLATED LIGHTNING STRIKES OVERNIGHT SOUTH OF GJT. THIS FEATURE WILL MOVE ACROSS THE CENTRAL PLAINS TODAY AND APPROACH THE WESTERN EDGE OF MORE MOIST/UNSTABLE AIRMASS LATER THIS AFTERNOON AND EVENING. LOW LEVEL WARM ADVECTION AND LIFT WILL HELP TO INITIATE SCATTERED THUNDERSTORMS OVER EASTERN NEB/NORTHEAST KS AFTER 00Z...SPREADING NORTHEASTWARD ACROSS IA DURING THE NIGHT. PRESENT INDICATIONS ARE THAT WEAK INSTABILITY WILL PRECLUDE A RISK OF ORGANIZED SEVERE STORMS. ...PACIFIC NORTHWEST COAST... VIGOROUS UPPER TROUGH IS MOVING ASHORE THIS MORNING ALONG THE WA/ORE COASTS. ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE ALONG COASTAL RANGES EARLY TODAY AS SYSTEM PASSES. OTHER CONVECTION MAY DEVELOP THIS AFTERNOON IN WAKE OF SHORTWAVE TROUGH DUE TO COLD TEMPERATURES ALOFT AND OROGRAPHIC LIFT. ..HART/TAYLOR.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 16:11:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 11:11:12 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261614 SWODY1 SPC AC 261611 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1011 AM CST SUN NOV 26 2006 VALID 261630Z - 271200Z ...NO SVR TSTM AREAS FORECAST... UPPER TROUGH OVER WRN U.S. WILL DEEPEN THIS FORECAST PERIOD IN RESPONSE TO A VIGOROUS SYSTEM NOW MOVING INTO PAC NW. BROAD SWLY FLOW PREVAILS FROM THE SWRN U.S. TO THE GREAT LAKES. A WEAKENING MID LEVEL IMPULSE EMBEDDED IN THIS FLOW CURRENTLY VICINITY CO WILL MOVE QUICKLY ACROSS PLAINS AND UPPER MS VALLEY BY MON AM. RETURN OF MODIFIED GULF MOISTURE WILL CONTINUE INTO MON SRN/CENTRAL PLAINS ACROSS MID MS VALLEY UNDER SWLY FLOW AT ALL LEVELS. INSUFFICIENT INSTABILITY AND ONLY WEAK UPPER SUPPORT WILL BE ASSOCIATED WITH THE IMPULSE MOVING ACROSS THE PLAINS TODAY TO SUPPORT ANY THREAT OF SEVERE THUNDERSTORMS. HOWEVER CONVECTION IS EXPECTED TO INCREASE MAINLY OVERNIGHT AS UPPER LEVEL IMPULSE INTERACTS WITH PLUME OF MODIFIED GULF MOISTURE FROM ERN NE/KS TO WI. THUNDERSTORMS THIS AREA WILL BE ELEVATED...BUT WITH MUCAPES POSSIBLY TO 500 J/KG...MID LEVEL LAPSE RATES AROUND 7C/KM AND LOW WET BULB ZERO LEVELS...THERE COULD BE SMALL HAIL ASSOCIATED WITH MORE VIGOROUS UPDRAFTS. IN THE WAKE OF SURFACE LOW MOVING INLAND WRN WA TODAY A COLD AND WEAKLY UNSTABLE ONSHORE FLOW WILL DEVELOP. THIS SHOULD SUPPORT A FEW LOW TOPPED THUNDERSTORMS COASTAL AREA PAC NW...MOST LIKELY AFTER 00Z. ..HALES/JEWELL.. 11/26/2006  From swody1 at goshenarc.org Sun Nov 26 19:49:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 14:49:19 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261951 SWODY1 SPC AC 261949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0149 PM CST SUN NOV 26 2006 VALID 262000Z - 271200Z ...NO SVR TSTM AREAS FORECAST... BROAD SOUTHWESTERLY FLOW WILL REMAIN IN PLACE TONIGHT ACROSS MOST OF THE UNITED STATES AS AN UPPER-TROUGH COMES ASHORE IN THE PACIFIC NORTHWEST. THUNDERSTORM ACTIVITY MAY OCCUR ALONG THE WEST COAST ASSOCIATED WITH COLD AIR ALOFT IN THE UPPER-TROUGH AS THE STRONGER BANDS OF LARGE-SCALE ASCENT MOVE INLAND LATE TONIGHT. OTHERWISE...A FEW THUNDERSTORMS MAY ALSO OCCUR IN THE CNTRL PLAINS AND UPPER MIDWEST ALONG THE NOSE OF THE LOW-LEVEL JET AS LOW-LEVEL MOISTURE ADVECTION INCREASES TONIGHT. NONE OF THE THUNDERSTORM ACTIVITY IS EXPECTED TO APPROACH SEVERE LIMITS. ..BROYLES.. 11/26/2006  From swody1 at goshenarc.org Mon Nov 27 00:48:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 26 Nov 2006 19:48:59 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270051 SWODY1 SPC AC 270049 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0649 PM CST SUN NOV 26 2006 VALID 270100Z - 271200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL PLAINS NEWD TO PARTS OF WRN GREAT LAKES... EARLY EVENING SATELLITE IMAGERY INDICATED A LOW AMPLITUDE SHORT WAVE TROUGH OVER NEB/NRN KS. THIS FEATURE WILL PROGRESS NEWD WITHIN SWLY FLOW ALOFT...REACHING SERN MN/WI BY 12Z MONDAY...AS THE NEXT UPSTREAM IMPULSE TRACKS NEWD INTO THE SRN HIGH PLAINS. IN THE LOW LEVELS...AN ARCTIC COLD FRONT WILL CONTINUE TO SPREAD SWD THROUGH THE CENTRAL PLAINS OVERNIGHT AND SHOULD EXTEND FROM THE NRN TX PANHANDLE/NW OK REGION NEWD INTO NWRN MO AND CENTRAL IA TO SERN MN BY END OF DAY 1 PERIOD. MEANWHILE...A SECOND BOUNDARY MARKING NWD EXTENT OF LOW LEVEL MOISTURE RETURN /SURFACE DEWPOINTS IN THE LOWER 50S/ SHOULD REMAIN STATIONARY FROM NERN IA THROUGH SRN WI TO CENTRAL LOWER MI. STRENGTHENING SWLY LLJ EXTENDING FROM SRN PLAINS TO SRN/ERN IA WILL MAINTAIN MOISTURE RETURN...WHILE ASCENT WITHIN WAA IN VICINITY OF LLJ AND DEEP LAYER ASCENT AHEAD OF CENTRAL PLAINS TROUGH EXPECTED TO SUPPORT INCREASE IN CONVECTION. ACTIVITY SHOULD SPREAD NEWD ALONG/N OF STATIONARY BOUNDARY...POTENTIALLY REACHING LM AND WRN LOWER MI AS UPPER TROUGH APPROACHES WI BY 27/12Z. PLUME OF STEEP LAPSE RATES /7.5 TO 8 C/KM PER 27/00Z SOUNDINGS FROM NEB TO WI/ ATOP LOW LEVEL WARM AIR AND MOISTURE ADVECTION COMBINED WITH EFFECTIVE BULK SHEAR OF 25-30 KT SUGGEST POTENTIAL FOR MARGINALLY SEVERE HAIL WITH STRONGER STORMS. HOWEVER...SEVERE THREAT SHOULD REMAIN TOO LOW... GIVEN WEAK INSTABILITY...AND THUS PRECLUDE INTRODUCTION OF SEVERE PROBABILITIES. SECOND AREA OF INCREASING ISENTROPIC ASCENT...IN ADVANCE OF IMPULSE APPROACHING SRN HIGH PLAINS...OVER PARTS OF CENTRAL KS AND POTENTIALLY FAR NW OK TO THE NORTH OF SURGING COLD FRONT SUGGESTS THREAT FOR TSTMS LATE IN FORECAST PERIOD. ...PACIFIC NW COAST SWD ALONG NRN/CENTRAL CA COAST... A FEW LIGHTNING STRIKES REMAIN POSSIBLE...MAINLY ALONG AND OFFSHORE OF THE CENTRAL CA COAST...AS ASCENT WITH A SHORT WAVE TROUGH SPREADS SEWD ACROSS CENTRAL TO SRN CA. ADDITIONAL TSTMS ARE POSSIBLE FARTHER N ALONG THE PACIFIC NW COAST AS COLD MID LEVEL TEMPERATURES /LESS THAN -30 C AT 500 MB/ WITH DEEPENING VORTEX SPREAD INLAND ATOP MOIST...POST-FRONTAL ONSHORE FLOW. ..PETERS.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 05:42:46 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 00:42:46 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270545 SWODY1 SPC AC 270542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1142 PM CST SUN NOV 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID/UPPER LEVEL TROUGH...CURRENTLY DEEPENING ACROSS THE PACIFIC NW AND INTERMOUNTAIN WEST...IS EXPECTED TO BEGIN TO MOVE EWD THIS FORECAST PERIOD. THIS WILL OCCUR AS STRONG MID/UPPER LEVEL WINDS TRANSLATE INTO THE BASE OF THIS TROUGH FROM THE GREAT BASIN EWD TO THE CENTRAL PLAINS. A COUPLE OF SHORT WAVE TROUGHS WITHIN SWLY FLOW ALOFT WILL TRACK NEWD ACROSS THE CENTRAL STATES THROUGH TONIGHT. COLD FRONT IS EXPECTED TO EXTEND FROM THE TX PANHANDLE/NW OK NEWD THROUGH ERN KS TO ERN IA...AND THEN EWD ACROSS SRN WI TO LOWER MI AT 12Z TODAY. THIS BOUNDARY SHOULD REMAIN MAINLY STATIONARY INTO THE AFTERNOON...WITH A SURFACE WAVE DEVELOPING OVER WRN OK BY LATE AFTERNOON AS LEAD SHORT WAVE TROUGH TRACKS ACROSS OK/KS. THIS IMPULSE WILL CONTINUE TO MOVE NEWD ACROSS THE MID/LOWER MO VALLEYS TO THE WRN GREAT LAKES REGION TONIGHT. THE ATTENDANT SURFACE LOW SHOULD MOVE MORE NWD INTO WRN/NRN IA AS STRONGER HEIGHT FALLS/ SURFACE PRESSURE FALLS DEVELOP ACROSS THE NRN PLAINS AND UPPER MIDWEST IN RESPONSE TO EWD PROGRESSION OF WRN LONG WAVE TROUGH. KS/MO PORTION OF SURFACE FRONT WILL LIKEWISE RETREAT NWD AFTER 28/00Z TO ALONG THE IA/MN BORDER BY 12Z TUESDAY. MEANWHILE... PRIMARY CYCLONE IS EXPECTED TO DEEPEN OVER WY TODAY...BEFORE MOVING EWD INTO SD BY TUESDAY MORNING. ...SRN PLAINS NEWD TO MID MO VALLEY... LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NEWD ALONG/E OF SURFACE FRONT AS SSWLY LLJ EXTENDING FROM SRN PLAINS TO LOWER MO/MID MS VALLEYS STRENGTHENS THROUGH THE FORECAST PERIOD...WITH EXTENSIVE CLOUDINESS LIKELY LIMITING AIR MASS DESTABILIZATION. ELEVATED TSTMS MAY BE ONGOING AT 12Z TODAY OVER PARTS OF CENTRAL KS/NW OK WITHIN REGION OF ISENTROPIC ASCENT NORTH OF COLD FRONT. DEEP LAYER ASCENT AND SUBSEQUENT POTENTIAL FOR TSTMS WILL CONTINUE TO INCREASE INITIALLY ACROSS KS/NW OK...AND THEN SWD THROUGH OK AND W/NW TX ALONG LEE TROUGH/DRY LINE WITH APPROACH OF LEAD SHORT WAVE TROUGH. GENERALLY WEAK INSTABILITY WITH THIS LEAD TROUGH IS EXPECTED TO LIMIT SEVERE THREAT THROUGH 28/00Z. AN EXCEPTION MAY EXIST ACROSS WRN OK/ERN TX PANHANDLE WHERE MLCAPE MAY BE AROUND 500 J/KG BY LATE AFTERNOON...SUPPORTING A THREAT FOR ISOLATED HAIL/ STRONG WINDS. GREATER SEVERE THREAT...THOUGH STILL ISOLATED IN COVERAGE GIVEN TIME OF DAY AND SOMEWHAT WEAK INSTABILITY...IS EXPECTED AFTER 28/00Z AS STEEPER MID LEVEL LAPSE RATES/STRONGER FORCING SPREAD NEWD ACROSS CENTRAL/SRN PLAINS AHEAD OF STRONGER IMPULSE...NOW LOCATED OVER CENTRAL CA. THIS ACTIVITY AND ATTENDANT SEVERE THREAT SHOULD DEVELOP NEWD AND MAY REACH PARTS OF IA/WRN MO BY 12Z TUESDAY. ..PETERS/TAYLOR.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 12:39:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 07:39:23 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271241 SWODY1 SPC AC 271239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0639 AM CST MON NOV 27 2006 VALID 271300Z - 281200Z ...NO SVR TSTM AREAS FORECAST... LARGE UPPER TROUGH IS IN PLACE THIS MORNING OVER MOST OF THE CENTRAL AND WESTERN UNITED STATES...WHILE UPPER RIDGE REMAINS ACROSS THE SOUTHEAST. ONE SHORTWAVE TROUGH NOTED ON WATER VAPOR IMAGERY OVER NM WILL TRACK NORTHEASTWARD ACROSS THE CENTRAL PLAINS TODAY. SURFACE BAROCLINIC ZONE LIES ALONG AN AXIS FROM THE NORTHWEST TX PANHANDLE INTO NORTHEAST KS...AND WILL MOVE VERY LITTLE THROUGH 00Z. INCREASINGLY STRONG SOUTHERLY LOW LEVEL WINDS WILL CONTINUE TO HELP TRANSPORT MOIST AND MARGINALLY UNSTABLE AIR MASS NORTHWARD ACROSS TX/OK/KS. FORCING FOR LARGE SCALE ASCENT WILL INCREASE BY LATE MORNING ALONG FRONTAL ZONE AS UPPER TROUGH APPROACHES. THIS IS EXPECTED TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS FROM WESTERN OK INTO KS AND NORTHWEST MO. FORECAST SOUNDINGS SHOW ONLY MARGINAL LAPSE RATES. HOWEVER...STRENGTH OF WIND FIELDS/VERTICAL SHEAR COUPLED WITH SUFFICIENT INSTABILITY MAY LEAD TO AN ISOLATED STRONG/SEVERE STORM THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND HAIL. THREAT SHOULD BE RESTRICTED TO A NARROW ZONE ALONG AND IMMEDIATELY EAST OF FRONTAL ZONE. ELSEWHERE IN THE NATION...ISOLATED THUNDERSTORMS WILL BE POSSIBLE ALONG THE PACIFIC NORTHWEST COAST AND THE INTERMOUNTAIN WEST. NO SEVERE STORMS ARE FORECAST IN THESE REGIONS. ..HART/TAYLOR.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 16:21:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 11:21:33 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271624 SWODY1 SPC AC 271621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1021 AM CST MON NOV 27 2006 VALID 271630Z - 281200Z ...NO SVR TSTM AREAS FORECAST... LARGE COLD UPPER TROUGH CONTINUES TO DEEPEN OVER WRN U.S WITH A BROAD SWLY FLOW FROM THE ROCKIES TO THE APPALACHIANS. LEADING EDGE OF THE ARCTIC AIR FROM CENTRAL IA TO NWRN OK/TX PANHANDLE WILL BEGIN RETREATING NWD INTO KS THIS AFTERNOON AS PRESSURE FALLS DEVELOP LEE OF ROCKIES. MODIFIED GULF MOISTURE CONTINUES TO STREAM NWD/NEWD THRU SRN/CENTRAL PLAINS ON 30KT LOW LEVEL JET. LIMITED POTENTIAL INSTABILITY IN WARM SECTOR WITH LAPSE RATES GENERALLY LESS THAN 7C/KM AND EXTENSIVE CLOUDINESS. S/WV TROUGH EMBEDDED IN THE FLOW AROUND DEEP WESTERN SYSTEM CURRENTLY ROTATING NEWD FROM NM ACROSS THE PLAINS THIS AFTERNOON. GIVEN THE LIFT PROVIDED BY THE FRONT AND MLCAPES FROM 300-500 J/KG THIS AFTERNOON...THUNDERSTORMS EXPECTED TO DEVELOP VICINITY AND JUST E OF FRONTAL ZONE. WITH DEEP LAYER SHEAR FROM 40-50 KTS A FEW OF THE STORMS COULD BECOME STRONG/BRIEFLY SEVERE THIS AFTERNOON AND EVENING. COVERAGE AND EXPECTED LIMITED INTENSITY PRECLUDES A SLIGHT RISK. ..HALES/JEWELL.. 11/27/2006  From swody1 at goshenarc.org Mon Nov 27 19:45:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 14:45:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271947 SWODY1 SPC AC 271945 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0145 PM CST MON NOV 27 2006 VALID 272000Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SRN THROUGH CNTRL PLAINS... SERIES OF SHORT WAVE DISTURBANCES PIVOTING AROUND DEEP UPPER TROUGH ACROSS THE WEST WILL CONTINUE TO AID LARGE SCALE ASCENT OVER THE GREAT PLAINS THROUGH TONIGHT. THESE DISTURBANCES WILL ACT IN CONCERT WITH LOW LEVEL ISENTROPIC LIFT ACROSS A SHARP FRONTAL ZONE FROM TX/OK TO IA/WI TO PRODUCE SCATTERED CONVECTION. LOW LEVEL MOISTURE TRANSPORT AND A PLUME OF STEEPER MID LEVEL LAPSE RATES FROM THE SRN HIGH PLAINS ACROSS THE MO RIVER VALLEY WERE CONTRIBUTING TO POCKETS OF MUCAPE IN THE RANGE OF 300-800 J/KG. STRONGER ASCENT...ASSOCIATED WITH AN IMPULSE NOW MOVING TOWARD THE AZ/NM BORDER...SHOULD RESULT IN A GRADUAL INCREASE IN TSTM ACTIVITY ACROSS THE SRN PLAINS AREA THROUGH THIS EVENING. WHILE BOUNDARY LAYER AIR MASS BENEATH THIS INCREASING CONVECTION IS EXPECTED TO REMAIN QUITE STABLE...LAPSE RATES AND SHEAR IN THE CLOUD-BEARING LAYER COULD SUPPORT ISOLATED AND MARGINALLY SEVERE HAIL FROM WRN OK...ACROSS PARTS OF KS...AND INTO NWRN MO AND SWRN IA THROUGH LATE TONIGHT/EARLY TUESDAY. ..CARBIN.. 11/27/2006  From swody1 at goshenarc.org Tue Nov 28 00:58:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 27 Nov 2006 19:58:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280100 SWODY1 SPC AC 280058 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0658 PM CST MON NOV 27 2006 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SRN THROUGH CENTRAL PLAINS/MID MO VALLEY TO WI... SERIES OF SHORT WAVE DISTURBANCES /ONE CURRENTLY LOCATED OVER SWRN IA/ERN KS AND THE SECOND OVER THE SRN ROCKIES/ PIVOTING AROUND DEEP UPPER TROUGH ACROSS THE WEST WILL CONTINUE TO AID LARGE SCALE ASCENT OVER THE GREAT PLAINS THROUGH TONIGHT. THIS ASCENT WILL ACT IN CONCERT WITH LOW LEVEL ISENTROPIC LIFT ACROSS A SHARP FRONTAL ZONE FROM TX/OK TO IA/WI TO PRODUCE SCATTERED CONVECTION. LOW LEVEL MOISTURE TRANSPORT ALONG/E OF SURFACE FRONT WILL PERSIST THIS FORECAST PERIOD...AS KS/IA PORTION OF FRONT RETREATS NWD IN RESPONSE TO HEIGHT FALLS/SURFACE PRESSURE FALLS OVER THE NRN PLAINS TO UPPER MS VALLEY. INCREASING DEEP LAYER ASCENT/STEEPER LAPSE RATES SPREADING NEWD ACROSS THE SRN/CENTRAL PLAINS WITH APPROACH OF STRONGER SRN ROCKIES SHORT WAVE TROUGH SUGGEST GREATER DESTABILIZATION/TSTM DEVELOPMENT SHOULD OCCUR FROM OK TO ERN NEB. MOST OF THESE STORMS SHOULD BE LOCATED ATOP STABLE BOUNDARY LAYER AIR...NORTH OF FRONTAL ZONE...WHERE LAPSE RATES AND SHEAR IN CLOUD-BEARING LAYER COULD SUPPORT ISOLATED AND MARGINALLY SEVERE HAIL. ENHANCED LOW LEVEL SHEAR ALONG THE SURFACE FRONT MAY SUPPORT AN ISOLATED TORNADO ACROSS NRN OK/KS PORTION OF FRONT WHICH IS CLOSER TO STRONGER MOISTURE FEED. ...NERN NV/NRN UT TO SWRN WY... COLD MID LEVEL TEMPERATURES /AROUND -30 C AT 500 MB/ AND ASCENT WITH SHORT WAVE TROUGH...CURRENTLY LOCATED OVER NERN NV/SRN ID...WILL CONTINUE TO SUPPORT CONVECTIVE DEVELOPMENT AND EMBEDDED TSTMS ACROSS NRN UT INTO SWRN WY THIS EVENING. ..PETERS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 05:19:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 00:19:34 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280521 SWODY1 SPC AC 280519 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 PM CST MON NOV 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... WRN U.S. TROUGH WILL CONTINUE TO AMPLIFY AND MOVE EWD TODAY TOWARD THE ROCKIES AND PLAINS...AS A STRONG NLY MID/UPPER LEVEL JETS TRANSLATE SEWD ALONG THE WRN PERIPHERY OF THIS FEATURE FROM THE BC COAST INTO THE WRN STATES. MEANWHILE...SHORT WAVE TROUGH MOVING INTO THE CENTRAL/SRN PLAINS PRIOR TO 12Z TODAY WILL TRACK NEWD WITHIN STRENGTHENING BAND OF SWLY MID/UPPER LEVEL FLOW ALONG ERN PERIPHERY OF WRN U.S. LONG WAVE TROUGH. IN THE LOW LEVELS...PRIMARY SURFACE LOW SHOULD INITIALLY BE LOCATED OVER SD/NEB AND THEN MOVE NNEWD...REACHING SRN MANITOBA/WRN ONTARIO BY 12Z WEDNESDAY. A STRONG ARCTIC FRONT TRAILING THIS LOW WILL SPREAD E AND S ACROSS THE NRN INTO CENTRAL PLAINS AND UPPER MS VALLEY. WARM SECTOR IS EXPECTED TO SPREAD NWD INTO SERN MN/WI...IN ADVANCE OF THE APPROACHING COLD FRONT...WITH LOWER 50S SURFACE DEWPOINTS REACHING THAT REGION BY MID-LATE AFTERNOON. AT 12Z TODAY...CLUSTERS OF TSTMS SHOULD BE ONGOING ACROSS ERN PARTS OF THE CENTRAL/SRN PLAINS INTO THE MID MO VALLEY...WITHIN ZONE OF DEEP LAYER ASCENT AND STEEPER MID LEVEL LAPSE RATES ACCOMPANYING THE CENTRAL/SRN PLAINS SHORT WAVE TROUGH. A FEW OF THE STRONGER STORMS MAY BE CAPABLE OF PRODUCING SMALL TO POTENTIALLY MARGINALLY SEVERE HAIL THIS MORNING...THOUGH THIS THREAT APPEARS TOO MARGINAL TO INCLUDE SEVERE PROBABILITIES. AS THE LEAD TROUGH TRACKS TOWARD SRN CANADA...THIS ONGOING ACTIVITY IS EXPECTED TO LIFT NEWD TO THE WRN GREAT LAKES REGION BY AFTERNOON...BUT SHOULD TEND TO DECREASE IN INTENSITY AS IT MOVES AWAY FROM BETTER INSTABILITY. ADDITIONAL TSTMS ARE PROGGED TO DEVELOP ALONG THE COLD FRONT FROM SERN NEB TO ERN MN AS THIS BOUNDARY ADVANCES ESE INTO THE MID MO/ UPPER MS VALLEYS BY 29/00Z...WHERE THE RETREATING MOIST WARM SECTOR WILL HAVE RESULTED IN MARGINAL INSTABILITY. SOME OF THIS ACTIVITY MAY BECOME STRONG PRODUCING ISOLATED SEVERE GIVEN FORECAST OF STRONG VERTICAL SHEAR PROFILES. THESE STORMS SHOULD SPREAD EWD AND MAY ALSO DEVELOP SWD ALONG FRONT INTO ERN KS/MO. SEVERE THREAT APPEARS TOO MARGINAL TO INCLUDE PROBABILITIES...GIVEN THE EFFECTS OF THE MARGINAL INSTABILITY. ..PETERS/GRAMS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 12:18:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 07:18:32 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281220 SWODY1 SPC AC 281218 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0618 AM CST TUE NOV 28 2006 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...CENTRAL STATES... AN EXPANSIVE UPPER TROUGH IS IN PLACE THIS MORNING OVER MOST OF THE UNITED STATES...WITH THE EXCEPTION OF THE SOUTHEAST STATES. SEVERAL SMALLER FEATURES ARE ROTATING THROUGH THE TROUGH...RESULTING IN POCKETS OF PRECIPITATION THROUGHOUT THE WESTERN AND CENTRAL UNITED STATES. THE STRONGEST SHORTWAVE TROUGH IS NOW MOVING ACROSS WESTERN OK. STRONG FORCING FOR LARGE SCALE ASCENT IS OCCURRING AHEAD OF TROUGH ACROSS PARTS OF OK/KS/MO/NEB/IA/MN...WHERE SCATTERED THUNDERSTORMS ARE NOTED. THIS ACTIVITY WILL MOVE EASTWARD INTO PARTS OF WI/IL/AR AND WEAKEN THROUGH THE DAY AS IT ENCOUNTERS MORE STABLE AIR MASS. SMALL HAIL WILL BE POSSIBLE IN STRONGER STORMS THIS MORNING...BUT ORGANIZED SEVERE ACTIVITY IS NOT ANTICIPATED. ...CO/WY... ELSEWHERE...SHOWERS AND ISOLATED LIGHTNING STRIKES WILL BE POSSIBLE OVER THE HIGHER TERRAIN OF CO AND SOUTHERN WY THIS AFTERNOON AS DIURNAL HEATING...COLD TEMPERATURES ALOFT...AND SERIES OF SHORTWAVE TROUGHS AFFECT THE AREA. OVERALL THREAT OF DEEP CONVECTION APPEARS TOO MARGINAL TO OUTLOOK AT THIS TIME. ..HART/GRAMS.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 16:26:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 11:26:22 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281628 SWODY1 SPC AC 281626 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1026 AM CST TUE NOV 28 2006 VALID 281630Z - 291200Z ...NO SVR TSTM AREAS FORECAST... STRONG VERY COLD UPPER TROUGH WRN U.S. CONTINUES TO DEEPEN AS IT SLOWLY SHIFTS EWD. ONE STRONG IMPULSE LIFTING NEWD INTO SCENTRAL CANADA WHILE 140KT NLY POLAR JET PAC NW SUPPORTS CONTINUED AMPLIFICATION OVER CENTRAL/SRN ROCKIES. SURFACE LOW AHEAD OF ARCTIC FRONT OVER DAKOTAS TRACKS NEWD AS ARCTIC AIR CONTINUES TO PRESS SEWD THRU THE HIGH PLAINS. PAC FRONTAL ZONE EXTENDS FROM SURFACE LOW ERN CO SWWD INTO NRN AZ. THIS LOW WILL MOVE INTO TX PANHANDLE TONIGHT WITH PAC FRONT TRAILING WSWWD ACROSS AZ. AHEAD OF THESE SYSTEMS AND UPPER TROUGH THE STRONG SLY FLOW OF UNSEASONABLY WARM/MOIST AIR FROM THE PLAINS TO UPPER MS VALLEY WILL PERSIST THRU THE PERIOD. THE ACTIVE OVERNIGHT CONVECTION ACROSS THE PLAINS WAS TIED TO WEAKENING S/WV TROUGH NOW LIFTING NEWD ACROSS UPPER MS VALLEY. WHILE THE LOW LEVEL AIR MASS REMAINS MOIST...MID LEVEL VEERING/DRYING AND SUBSIDENCE IN WAKE OF S/WV TROUGH WILL PRECLUDE THREAT FOR STRONG/SEVERE THUNDERSTORMS MUCH OF THIS FORECAST PERIOD. OVERNIGHT WITH WARM ADVECTION AND DEEPENING MOISTURE INDICATED IN MODEL SOUNDINGS ACROSS THE CENTAL/SRN PLAINS AHEAD OF THE APPROACHING LARGE SCALE UPPER TROUGH...THERE IS SOME CONCERN THAT STRONG STORMS COULD DEVELOP. MODELS STILL INDICATING THE PRIMARY THREAT OF SEVERE THUNDERSTORMS WILL BE AFTER 12Z WED...SO FOR NOW WILL NOT INTRODUCE ANY SEVERE THREAT BUT TAKE ANOTHER LOOK AT THIS AREA DURING AFTERNOON DAY1 UPDATE. ..HALES/TAYLOR.. 11/28/2006  From swody1 at goshenarc.org Tue Nov 28 19:50:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 14:50:53 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281953 SWODY1 SPC AC 281951 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0151 PM CST TUE NOV 28 2006 VALID 282000Z - 291200Z ...NO SVR TSTM AREAS FORECAST... SCATTERED TSTMS PERSIST WITHIN WARM AIR ADVECTION REGIME ON THE APEX OF LOW LEVEL MOIST AXIS FROM SERN MN ACROSS WI AND NRN IL THIS AFTERNOON. THIS ACTIVITY WAS BEING FURTHER SUPPORTED BY A LOW AMPLITUDE SHORT WAVE TROUGH EJECTING NEWD ACROSS THE REGION. ADDITIONAL ISOLATED TSTMS HAVE RECENTLY DEVELOPED AHEAD OF A STRONG COLD FRONT MOVING ACROSS IA. DEEP-LAYER SLY/SWLY FLOW BETWEEN STRONG WRN U.S. TROUGH AND SERN U.S RIDGE WILL MAINTAIN A CORRIDOR OF HIGHER BOUNDARY LAYER MOISTURE TOPPED BY GENERALLY WEAK MID LEVEL LAPSE RATES FROM THE SRN PLAINS ACROSS THE MO RIVER VALLEY THROUGH TONIGHT. MUCAPE VALUES WITHIN MUCH OF THIS CORRIDOR ARE EXPECTED TO REMAIN WEAK/MARGINAL WITH THE POSSIBLE EXCEPTION OF THE TX/OK AREAS WHERE MUCAPE IS FORECAST TO INCREASE TO AROUND 1000 J/KG THROUGH THE REMAINDER OF THIS FORECAST PERIOD. COLD FRONT ASSOCIATED WITH THE WRN LARGE SCALE TROUGH WILL EDGE STEADILY ESEWD ACROSS THE MO VALLEY AND MUCH OF KS THROUGH TONIGHT. A NARROW WARM CONVEYOR BELT AIDED BY NOCTURNAL INCREASE IN LOW LEVEL JET WILL PRECEDE THE FRONT FROM OK NEWD ACROSS ERN KS/WRN MO AND WILL RESULT IN INCREASING ASCENT NEAR AND ACROSS THE BOUNDARY. CONVECTION IS EXPECTED TO GRADUALLY DEVELOP WITHIN THE CONVEYOR BELT AND ALONG/BEHIND THE COLD FRONTAL CIRCULATION AS IT DEVELOPS INTO THE MOIST AXIS THROUGH THE NIGHT. WHILE FORCING...SHEAR...AND INSTABILITY ACROSS THE REGION APPEAR SUFFICIENT TO MAINTAIN AREAS OF DEEP CONVECTION...WEAK LAPSE RATES ARE LIKELY TO TEMPER SEVERE WEATHER /HAIL/ POTENTIAL UNTIL AFTER DAYBREAK WEDNESDAY. ..CARBIN.. 11/28/2006  From swody1 at goshenarc.org Wed Nov 29 00:51:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 28 Nov 2006 19:51:58 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290054 SWODY1 SPC AC 290052 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0652 PM CST TUE NOV 28 2006 VALID 290100Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...NERN OK/NWRN AR/SERN KS INTO SWRN AND CENTRAL MO... SURFACE LOW LOCATED OVER NRN MN AND ASSOCIATED WITH SHORT WAVE TROUGH NOW MOVING NEWD INTO ONTARIO WILL TEND TO TRACK MORE NWD OVERNIGHT IN RESPONSE TO STRONG HEIGHT FALLS EXPECTED OVER ND/SRN MANITOBA AS ERN MT SHORT WAVE TROUGH APPROACHES SRN CANADA. COLD FRONT TRAILING SWD FROM THIS LOW WILL CONTINUE EWD INTO THE WRN GREAT LAKES REGION AND SEWD INTO THE MID MS VALLEY AND SRN PLAINS...AS LARGE SCALE WRN TROUGH EDGES EWD. TSTMS WILL REMAIN POSSIBLE AS THE PROGRESSIVE COLD FRONT MOVES INTO A NARROW MOIST AXIS AHEAD OF THIS BOUNDARY. WEAK MID LEVEL LAPSE RATES SHOULD LIMIT UPDRAFT STRENGTH AND ANY SEVERE THREAT ALONG THE NRN EXTENT OF THE FRONT INTO THE WRN GREAT LAKES REGION. FARTHER S...TSTMS SHOULD DEVELOP LATER TONIGHT...LIKELY AFTER 06Z... FROM ERN KS/NERN OK AS THE COLD FRONT ADVANCES SEWD AND SWLY LLJ EXTENDING FROM TX/ERN OK TO OZARK PLATEAU STRENGTHENS. DEEP LAYER ASCENT IS EXPECTED TO INCREASE ACROSS THIS REGION LATE TONIGHT DUE TO WAA ALONG NOSE OF LLJ AND WITHIN EXIT REGION OF 70 KT MID LEVEL JET APPROACHING FROM THE SRN HIGH PLAINS. LOW LEVEL MOIST/WARM AIR ADVECTION BENEATH STEEPER MID LEVEL LAPSE RATES ACCOMPANYING SRN HIGH PLAINS JETLET SHOULD SUPPORT MUCAPE 500-1000 J/KG. THIS COMBINED WITH INCREASING EFFECTIVE BULK SHEARS SUGGEST POTENTIAL FOR ROTATING STORMS. STRONGER STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED HAIL AND/OR STRONG WIND GUSTS AS ACTIVITY SPREADS INTO NWRN AR TO CENTRAL MO. ..PETERS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:34:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:34:05 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290636 SWODY1 SPC AC 290556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:43:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:43:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290645 SWODY1 SPC AC 290556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST TUE NOV 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 06:56:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 01:56:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 290658 SWODY1 SPC AC 290657 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CST WED NOV 29 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MID MS VALLEY... RESENT PER REQUEST ...SYNOPSIS... BROAD WRN U.S UPPER TROUGH IS EXPECTED TO TRACK EWD AND UNDERGO AMPLIFICATION TODAY AS A STRONG SHORT WAVE TROUGH DIGS SEWD FROM THE GREAT BASIN...REACHING THE SRN HIGH PLAINS BY 12Z THURSDAY. THE UPPER TROUGH AXIS SHOULD EXTEND FROM CENTRAL CANADA SWWD TO THE SRN HIGH PLAINS/FAR NRN MEXICO BY THE END OF THE FORECAST PERIOD. A WEAKER MID LEVEL IMPULSE EMANATING FROM THE NRN BAJA REGION...AT THIS TIME...SHOULD TRANSLATE NEWD WITHIN STRENGTHENING MID/UPPER LEVEL SWLY FLOW BETWEEN UPPER TROUGH AND BUILDING RIDGE ALONG/OFF THE EAST COAST. THIS IMPULSE SHOULD MOVE ACROSS THE SRN PLAINS TODAY AND INTO THE MID MS/LOWER OH VALLEYS TONIGHT. IN THE LOW LEVELS...STRONG COLD FRONT ALONG LEADING EDGE OF UPPER TROUGH WILL CONTINUE TO MOVE E AND S INTO THE GREAT LAKES...MIDWEST AND SRN PLAINS. ...CENTRAL/NRN TX TO ERN OK/OZARKS AND NEWD TO IL... CONTINUED MOISTURE TRANSPORT AHEAD OF THE COLD FRONT IS EXPECTED TO MAINTAIN LOWER TO MID 60S SURFACE DEWPOINTS ACROSS THE SRN PLAINS... WHILE MID TO UPPER 50S DEWPOINTS SPREAD NEWD INTO IL AND SRN GREAT LAKES REGION. WEAK MID LEVEL LAPSE RATES WILL TEND TO PRECLUDE DEVELOPMENT OF STRONGER INSTABILITY ALONG NRN EXTENT OF COLD FRONT WITH MUCAPE VALUES GENERALLY AOB 500 J/KG. GREATER BOUNDARY LAYER MOISTURE AND THE POTENTIAL FOR SURFACE HEATING FROM TX TO SERN OK SHOULD COMPENSATE FOR WEAK MID LEVEL LAPSE RATES AND RESULT IN MODERATE INSTABILITY FROM PARTS OF SRN OK SWD INTO CENTRAL TX. DEEP LAYER SHEAR WILL BE INCREASING THROUGH THE DAY ALONG THE FRONTAL ZONE...AS DEEP SWLY WIND FIELDS STRENGTHEN WITH THE APPROACH OF THE AMPLIFYING UPPER TROUGH. AT 12Z TODAY...TSTMS MAY BE ONGOING ACROSS PARTS OF NERN OK/NWRN AR INTO MO. THIS ACTIVITY SHOULD DEVELOP/SPREAD NEWD ALONG THE ADVANCING COLD FRONT...WITH INCREASINGLY STRONG UNIDIRECTIONAL SHEAR PROFILES SUGGESTING SOME POTENTIAL FOR NEAR SURFACE-BASED CONVECTION TO POSE A THREAT FOR SEVERE HAIL AND/OR HIGH WINDS. GIVEN FAVORABLE LARGE SCALE SUPPORT AS DEEP LAYER ASCENT INCREASES WITHIN THE ENTRANCE REGION OF THE INTENSIFYING UPPER JET...TSTMS SHOULD NOT ONLY DEVELOP NEWD FROM THE ONGOING ACTIVITY...BUT ALSO SWWD ALONG THE FRONT THIS AFTERNOON AS THE AIR MASS DESTABILIZES. HAIL AND STRONG WINDS WILL BE A THREAT GIVEN SHEAR PROFILES BECOMING SUPPORTIVE OF SUSTAINED UPDRAFTS. A SUPERCELL TORNADO AND/OR LARGE HAIL THREAT APPEAR POSSIBLE ACROSS THE RED RIVER VALLEY REGION AND SWD INTO CENTRAL TX THIS AFTERNOON AND EVENING. LOW LEVEL SHEAR VALUES SHOULD BE ENHANCED ACROSS THESE AREAS WHERE THE PROGRESSIVE COLD FRONT INTERSECTS A SWD EXTENDING DRY LINE. BULK OF CONVECTION IS LIKELY TO LINE UP ALONG OR IMMEDIATELY BEHIND THE DEEPER FRONTAL CIRCULATION DEVELOPING ESEWD THROUGH THE EVENING. IT IS POSSIBLE A LINEAR MCS WITH A CONTINUING SEVERE THREAT COULD EVOLVE FROM CENTRAL/NERN TX INTO THE OZARKS TONIGHT. ..PETERS/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 12:46:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 07:46:18 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291248 SWODY1 SPC AC 291245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 AM CST WED NOV 29 2006 VALID 291300Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO THE MID MISSISSIPPI VALLEY... POWERFUL SHORTWAVE TROUGH NOW OVER WESTERN NM WILL TRACK EASTWARD AND INTO THE SOUTHERN PLAINS TODAY. MEANWHILE...ARCTIC COLD FRONT WILL SURGE SOUTHEASTWARD THROUGH WESTERN MO/OK/NORTHWEST TX. INCREASINGLY MOIST AND MODERATELY UNSTABLE AIR MASS IS IN PLACE AHEAD OF FRONT WHERE SURFACE DEWPOINTS ARE IN THE LOW-MID 60S. SCATTERED THUNDERSTORMS ARE BEGINNING TO FORM ALONG FRONT FROM NORTH-CENTRAL OK INTO WESTERN MO. THIS TREND IS LIKELY TO CONTINUE THROUGH THE MORNING WITH DEVELOPMENT AS FAR SOUTH AS THE RED RIVER EXPECTED. THESE STORMS ARE LIKELY TO BE QUICKLY UNDERCUT BY FAST-MOVING FRONT. HOWEVER...MORNING OBSERVED AND MODEL FORECAST SOUNDINGS IN THIS ZONE SHOW SUFFICIENT CAPE AND DEEP LAYER VERTICAL SHEAR FOR A RISK OF HAIL IN STRONGEST CELLS. AIR MASS OVER CENTRAL AND NORTH-CENTRAL TX IS EXPECTED TO BECOME MODERATELY UNSTABLE BY EARLY AFTERNOON...WITH DEWPOINTS IN THE MID 60S ALONG/EAST OF DRYLINE. STRONG HEATING WEST OF THE DRYLINE... COOLING MID LEVEL TEMPERATURES...AND INCREASING LARGE SCALE FORCING WILL ENHANCE DESTABILIZATION AND LIKELY LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT. FORECAST SOUNDINGS IN THIS AREA SHOW VERY FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR PROFILES FOR SUPERCELLS CAPABLE OF DAMAGING WINDS AND ISOLATED TORNADOES. THIS ACTIVITY WILL LIKELY INCREASE IN AREAL COVERAGE THROUGH THE AFTERNOON/EARLY EVENING AND SPREAD INTO PARTS OF SOUTHEAST OK AND WESTERN AR. VERY STRONG WIND FIELDS AT ALL LEVELS WILL PROMOTE THE POTENTIAL FOR DAMAGING WINDS...AS WELL AS LARGE HAIL. STORMS WILL LIKELY PERSIST THROUGH THE NIGHT INTO PARTS OF MO/IL...WHERE STRONG WIND FIELDS MAY BE SUFFICIENT TO MAINTAIN ISOLATED SEVERE THREAT DESPITE VERY MARGINAL INSTABILITY. ..HART/GRAMS.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 16:05:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 11:05:31 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291606 SWODY1 SPC AC 291604 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1004 AM CST WED NOV 29 2006 VALID 291630Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO THE MID MISSISSIPPI VALLEY... POWERFUL S/WV TROUGH WILL CROSS NM THIS AFTERNOON REACHING SRN PLAINS OVERNIGHT. STRONG ARCTIC FRONT AT 15Z FROM NERN MO TO CENTRAL OK/SRN TX PANHANDLE CONTINUES PRESSING SEWD. STRONG SLY FLOW OFF WRN GULF OF MEXICO CONTINUES TO INCREASE MOISTURE AND INSTABILITY NWD THRU SRN PLAINS INTO MID MS VALLEY AHEAD OF THE FRONT. THUNDERSTORMS ARE DEVELOPING ALONG AND TO COLD SIDE OF SHALLOW ARCTIC FRONT THIS AM FROM WRN IL TO NRN OK. WITH MARGINAL INSTABILITY AND STRONG DEEP LAYER SHEAR...INITIAL THREAT WILL BE HAIL AND LOCAL DAMAGING WINDS WITH STORMS THAT DEVELOP ALONG FRONTAL ZONE THRU THE EARLY AFTERNOON FROM OK TO WRN IL. ELEVATED INSTABILITY WILL ALSO RESULT IN MARGINALLY SEVERE HAIL THREAT SOME DISTANCE TO THE COLD SIDE OF SURFACE FRONT. FURTHER S WARM SECTOR AIR MASS WILL BECOME SUPPORTIVE OF SURFACE BASED THUNDERSTORMS AHEAD OF THE FRONT ACROSS NRN TX BY MID AFTERNOON WHERE MLCAPES WILL CLIMB TO AOA 2000 J/KG. GIVEN 50-60 KT OF DEEP LAYER SHEAR...SUPERCELLS ARE LIKELY ENHANCING BOTH THE LARGE HAIL AND TORNADO POTENTIAL. STORMS SHOULD SPREAD E/NEWD ACROSS NRN TX/SERN OK INTO WRN AR THIS EVENING WITH APPROACH OF STRONG UPPER SUPPORT FROM THE W. ..HALES/GUYER.. 11/29/2006  From swody1 at goshenarc.org Wed Nov 29 19:56:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 14:56:21 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 291958 SWODY1 SPC AC 291956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST WED NOV 29 2006 VALID 292000Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX NEWD TO MO/IL... ...NRN TX/SERN OK/NWRN AR... POWERFUL COLD FRONT CONTINUES TO SPREAD SEWD ACROSS NWRN TX AND SERN OK LATE THIS AFTERNOON. MOIST AND INCREASING UNSTABLE AIR MASS WAS DEVELOPING AHEAD OF AND ACROSS THE VERY SHARP FRONT AND CONTRIBUTING TO AN EXPANDING AREA OF DEEP CONVECTION FROM THE RED RIVER VALLEY NEWD ACROSS ECNTRL OK...AND INTO PARTS OF SERN KS AND WRN MO. SO FAR...THE BULK OF THIS CONVECTION HAS OCCURRED ON THE IMMEDIATE COLD SIDE OF THE SURFACE FRONT. HOWEVER...THAT HAS BEGUN TO CHANGE ACROSS NORTH TX WHERE NEAR SURFACE-BASED STORMS APPEAR TO HAVE FORMED OVER THE PAST 1-2 HOURS. EXPECT TREND OF PRE-FRONTAL SURFACE-BASED CONVECTIVE DEVELOPMENT TO CONTINUE ACROSS PARTS OF NRN TX...SERN OK...AND WRN AR THROUGH THIS EVENING. LATEST OBJECTIVE ANALYSIS DATA SUGGESTS THAT MLCAPE OF 1000-1500 J/KG AND STRONG SHEAR ACROSS THESE AREAS WILL INITIALLY SUPPORT SUPERCELLULAR STORMS WITH SOME POTENTIAL FOR A TORNADO OR TWO...IN ADDITION TO DAMAGING WINDS AND LARGE HAIL. EXPECT THIS ACTIVITY TO BECOME INCREASINGLY LINEAR AND UNDERCUT BY DEEPENING SYNOPTIC COLD POOL AS THE FRONT MAKES GRADUAL SEWD PROGRESS THROUGH THE NIGHT. LARGE SCALE ASCENT ASSOCIATED WITH AN INTENSE SHORT WAVE TROUGH APPROACHING FROM NM THROUGH LATE TONIGHT WILL AID IN STEEPENING MID LEVEL LAPSE RATES ATOP THE SURFACE-BASED COLD DOME. IN COMBINATION WITH PERSISTENT MOIST ISENTROPIC LIFT ACROSS THE FRONTAL ZONE...DEEP CONVECTION WITH THE CHANCE FOR HAIL WILL LIKELY REMAIN A THREAT ACROSS PARTS OF TX/OK THROUGH LATE TONIGHT. ...MO/IL... AFTERNOON SOUNDINGS FROM SGF AND ILX INDICATED WEAKER LAPSE RATES AND MARGINAL INSTABILITY /MUCAPE AROUND 700 J PER KG/ IN THE PRE-FRONTAL ENVIRONMENT ACROSS THESE AREAS. HOWEVER...LATEST GUIDANCE REMAINS CONSISTENT IN SUGGESTING A CONTINUING POTENTIAL FOR VIGOROUS CONVECTIVE DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT THROUGH THIS EVENING. THIS DEVELOPMENT WILL OCCUR WITHIN A SUFFICIENTLY STRONG FLOW REGIME WHERE UNIDIRECTIONAL SHEAR PROFILES FAVOR FAST-MOVING LINE SEGMENTS CAPABLE OF PRODUCING WIND DAMAGE AND PERHAPS MARGINALLY SEVERE HAIL. ..CARBIN.. 11/29/2006  From swody1 at goshenarc.org Thu Nov 30 00:56:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 29 Nov 2006 19:56:40 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300058 SWODY1 SPC AC 300056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST WED NOV 29 2006 VALID 300100Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF TX AND SERN OK THROUGH THE MID MS VALLEY... ...S CNTRL THROUGH NERN TX...SERN OK NWRN AR AND SRN MO... ARCTIC COLD FRONT EXTENDS FROM THE GREAT LAKES REGION SWWD THROUGH CNTRL AND SWRN MO...SERN OK INTO N CNTRL THROUGH WRN TX. THIS FRONT WILL CONTINUE TO SETTLE SEWD THE REMAINDER OF TONIGHT. PRE-FRONTAL WARM SECTOR IS CHARACTERIZED BY LOW 60S DEWPOINTS FROM TX THROUGH SERN OK WITH UPPER 50S TO NEAR 60 FARTHER NE INTO THE MID MS VALLEY. MUCAPE FROM 500 TO 1000 J/KG EXISTS FROM CNTRL THROUGH NERN TX INTO SERN OK...BUT DECREASES TO BELOW 500 J/KG FARTHER NE INTO THE MID MS VALLEY WHERE MID LEVEL LAPSE RATES ARE WEAKER AND LOW LEVEL MOISTURE IS MORE LIMITED. STORMS SHOULD CONTINUE DEVELOPING THIS EVENING PRIMARILY WITHIN ZONE OF FORCED LOW LEVEL ASCENT ALONG THE ARCTIC FRONT FROM CNTRL THROUGH NERN TX INTO ERN OK AND THE MID MS VALLEY. ORIENTATION OF THE SWLY MID LEVEL FLOW WITH RESPECT TO THE FRONT HAS RESULTED IN STORMS BEING UNDERCUT AND BECOMING ELEVATED SOON AFTER INITIATION. THIS SUGGESTS THE PRIMARY THREAT WITH THIS ACTIVITY SHOULD BE HAIL...ESPECIALLY GIVEN 6.5-7 C/KM 850-500 MB LAPSE RATES PRESENT ON COOL SIDE OF FRONT. OVERALL HAIL THREAT WILL REMAIN LIMITED BY MODEST INSTABILITY. STRONGER FORCING FOR ASCENT ASSOCIATED WITH UPPER TROUGH OVER NM SHOULD REMAIN W OF THE WARM SECTOR OVERNIGHT. HOWEVER...WV IMAGERY SHOWS A LEAD IMPULSE MOVING NEWD INTO SWRN TX. SOME INCREASE IN THE SLY LOW LEVEL JET MAY OCCUR AHEAD OF THIS FEATURE ACROSS PARTS OF CNTRL TX THROUGH THE LOWER MS VALLEY. A FEW STORMS MAY CONTINUE DEVELOPING WITHIN WARM ADVECTION REGIME ACROSS CNTRL TX PRE-FRONTAL WARM SECTOR. STRONG DEEP LAYER SHEAR AND STRENGTHENING LOW LEVEL SHEAR WILL MAINTAIN A THREAT FOR ISOLATED SUPERCELLS WITH THIS ACTIVITY. HOWEVER...MODEST LAPSE RATES AND COOLING BOUNDARY LAYER SHOULD SERVE AS LIMITING FACTORS FOR A MORE ROBUST SEVERE THREAT. ..DIAL.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 06:00:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 01:00:55 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300603 SWODY1 SPC AC 300600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1200 AM CST THU NOV 30 2006 VALID 301200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS AND TN VALLEYS INTO THE SERN U.S. AND A SMALL PART OF THE OH VALLEY... ...SYNOPSIS... STRONG SHORTWAVE TROUGH OVER NM WILL AMPLIFY ESEWD THROUGH THE SRN PLAINS THURSDAY BEFORE EJECTING NEWD INTO THE LOWER-MID MS VALLEY AND WRN TN VALLEY THURSDAY EVENING...REACHING THE OH VALLEY LATE THURSDAY NIGHT. ARCTIC FRONT SHOULD EXTEND FROM THE GREAT LAKES SWWD INTO AR AND SRN TX BY 12Z THURSDAY. CYCLOGENESIS WILL COMMENCE ALONG LOWER MS VALLEY PORTION OF FRONT THURSDAY AFTERNOON AS ASCENT WITHIN DIVERGENT EXIT REGION OF CYCLONIC UPPER JET BEGINS TO OVERTAKE WARM SECTOR. THE LOW WILL SUBSEQUENTLY DEEPEN AND LIFT NEWD INTO THE OH VALLEY OVERNIGHT. THIS SHOULD RESULT IN SRN PORTION OF THE COLD FRONT ACCELERATING EWD THROUGH THE TN VALLEY AND SERN U.S. THURSDAY EVENING AND NIGHT. ...SERN TX THROUGH THE LOWER MS AND TN VALLEYS AND SERN STATES... MODIFIED CP AIR WITH BOUNDARY LAYER DEWPOINTS MOSTLY IN THE LOW TO MID 60S WILL EXIST IN PRE-FRONTAL WARM SECTOR OVER THE LOWER MS VALLEY AND PORTIONS OF THE SERN STATES WITH NEAR 60 FARTHER N INTO THE TN AND OH VALLEYS. THIS MOISTURE WILL EXIST BELOW WEAK MID LEVEL LAPSE RATES WITH 5.5 C/KM EXPECTED IN THE 850-500 MB LAYER. THE WEAK LAPSE RATES AND LIMITED BOUNDARY LAYER HEATING SHOULD RESULT IN WEAK INSTABILITY WITH MLCAPE GENERALLY AOB 500 J/KG. BY 12Z THURSDAY STORMS WILL BE ONGOING MAINLY ON COLD SIDE OF ARCTIC FRONT FROM SERN TX INTO THE LOWER-MID MS VALLEY. ANY SEVERE THREAT WITH THIS ACTIVITY WILL BE MINIMAL DUE TO ELEVATED NATURE OF THE STORMS AND WEAK INSTABILITY. THREAT FOR SEVERE STORMS MAY INCREASE FARTHER EAST THURSDAY AFTERNOON INTO THURSDAY EVENING OVER PARTS OF THE LOWER MS VALLEY INTO THE TN VALLEY. DEEP LAYER FORCING ALONG FRONT WILL INCREASE IN THIS REGION AS THE SURFACE LOW DEEPENS AND LOW LEVEL JET STRENGTHENS. THIS MAY CONTRIBUTE TO A LINE OF LOW TOPPED CONVECTION...POSSIBLY WITH LITTLE OR NO LIGHTNING...ESPECIALLY FROM ERN AR...MS INTO WRN TN AND KY. WITH THE LOW LEVEL JET FORECAST TO STRENGTHEN TO 60+ KT...POTENTIAL WILL EXIST FOR MAINLY ISOLATED DAMAGING WIND ALONG THE LINE. SOME STORMS MAY BECOME UNDERCUT BY THE COLD AIR ACCOMPANYING EWD MOVING FRONT. HOWEVER...FRONT WILL BECOME ORIENTED MORE N-S DURING THE AFTERNOON S OF THE SURFACE LOW...AND THIS PORTION OF BOUNDARY MAY TREND TOWARD A KATAFRONT. THIS MAY SUPPORT A FEW SURFACE BASED STORMS BEING MAINTAINED ALONG THE SURFACE FRONT AS IT MOVES EWD THROUGH THE TN VALLEY AND SRN PORTIONS OF THE OH VALLEY. STRENGTHENING LOW-LEVEL AND CLOUD LAYER SHEAR PROFILES WOULD ALSO SUPPORT A THREAT OF SUPERCELL STRUCTURES EMBEDDED WITHIN THE LINE. ANY TORNADO THREAT WILL BE MAINLY LIMITED TO STORMS THAT CAN DEVELOP IN WARM SECTOR E OF ADVANCING COLD FRONT. HOWEVER...IT MAY BE DIFFICULT TO MAINTAIN DISCRETE UPRIGHT CONVECTION AWAY FROM THE FRONT IN SUCH A STRONGLY SHEARED ENVIRONMENT...AND THIS MAY SERVE AS A LIMITING FACTOR FOR A MORE ROBUST TORNADO THREAT. ..DIAL/GRAMS.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 12:41:04 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 07:41:04 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301243 SWODY1 SPC AC 301240 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0640 AM CST THU NOV 30 2006 VALID 301300Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE LOWER MS AND TN VALLEYS... ...LOWER MS AND TN VALLEYS... VIGOROUS UPPER TROUGH CONTINUES TO DIG SOUTHEASTWARD ACROSS NM...AND IS FORECAST TO EJECT EASTWARD ACROSS THE SOUTHERN PLAINS THROUGH TONIGHT. AS IT DOES SO...SYSTEM DEEPENS RAPIDLY AND MID LEVEL JET STRENGTHENS TO OVER 120 KNOTS. THIS PROCESS WILL RESULT IN VERY STRONG LARGE SCALE FORCING FOR ASCENT SPREADING ACROSS THE LOWER/MID MS VALLEY THIS EVENING. MODEL GUIDANCE IS IN GENERAL AGREEMENT THAT SURFACE LOW WILL DEEPEN OVER SOUTHERN AR BY MID AFTERNOON AND TRACK NORTHEASTWARD INTO WESTERN KY/TN. STRENGTHENING SOUTHERLY LOW LEVEL WINDS AHEAD OF LOW WILL DRAW INCREASINGLY MOIST/UNSTABLE AIR NORTHWARD WITH MID 60S DEWPOINTS EXPECTED INTO WESTERN TN. WEAK MID LEVEL LAPSE RATES WILL SUPPRESS THE DEVELOPMENT OF MORE THAN MARGINAL INSTABILITY IN WARM SECTOR. HOWEVER...EXTREMELY STRONG WIND FIELDS AND FORCING NEAR SURFACE LOW WILL LIKELY RESULT IN A LINE OF STRONG/SEVERE THUNDERSTORMS. THIS ACTIVITY WILL LIKELY FORM OVER SOUTHEAST AR/NORTHEAST LA AND RACE INTO PARTS OF KY/TN/MS BEFORE 06Z. DAMAGING WINDS ARE THE MOST LIKELY SEVERE THREAT. HOWEVER...INTENSE FORCING AND STRENGTH OF WIND FIELDS /OVER 100 KNOTS AT 500MB AND OVER 60 KNOTS AT 850MB/ SUGGEST THE POTENTIAL FOR TORNADOES IN ANY PERSISTENT SUPERCELLS THAT CAN FORM WITHIN OR AHEAD OF THE LINE. ..HART/GRAMS.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 16:23:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 11:23:16 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301625 SWODY1 SPC AC 301623 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1023 AM CST THU NOV 30 2006 VALID 301630Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE LOWER MS AND TN VALLEYS...... ....LOWER MS AND TN VALLEYS... CYCLOGENESIS IS JUST BEGINNING SWRN AR IN ADVANCE OF THE VIGOROUS TROUGH CURRENTLY ENTERING SRN PLAINS. BY LATER THIS AFTERNOON AND OVERNIGHT THE SURFACE LOW WILL DEEPEN RAPIDLY IN RESPONSE TO THE VERY STRONG UPPER SUPPORT FROM THE INTENSIFYING UPPER TROUGH MOVING ENEWD ACROSS THE SRN PLAINS TO THE LOWER OH VALLEY LATE TONIGHT. LEADING EDGE OF THE ARCTIC AIR MASS CURRENTLY SERN IL TO SURFACE LOW SWRN AR THEN TO S TX. FRONT TO NE OF DEVELOPING LOW WILL MOVE LITTLE TODAY WHILE IT PUSHES RAPIDLY SEWD OFF TX COAST. WHILE THE WARM SECTOR IS VERY MOIST WITH MID 60 DEWPOINTS SURGING NWD BY THIS AFTERNOON THRU MS INTO WRN TN...THE WEAK LAPSE RATES AND WARM MID/UPPER LEVELS IS GREATLY LIMITING THE INSTABILITY AVAILABLE FOR DEEP CONVECTION. MLCAPES OF JUST 200-400 J/KG ARE ABOUT ALL THAT CAN BE EXPECTED IN THE WARM SECTOR THRU TONIGHT. HOWEVER THE EXTREMELY STRONG WIND FIELDS AND FORCING AHEAD OF THE DEEPENING SURFACE LOW WILL RESULT IN THE DEVELOPMENT OF A LINE OF STRONG/SEVERE THUNDERSTORMS. THIS ACTIVITY WILL LIKELY FORM OVER SERN AR/NERN LA THIS AFTERNOON AND RACE NEWD ACROSS LOWER MS VALLEY AND PARTS OF KY/TN/MS PRIOR TO 06Z. DAMAGING WINDS ARE THE PRIMARY THREAT GIVEN THE INTENSE FORCING AND STRENGTH OF WIND FIELDS/OVER 100KT AT 500MB AND CLOSE TO 70 KT AT 850MB OVERNIGHT. THERE WILL ALSO BE POTENTIAL FOR ISOLATED TORNADOES WITH ANY SUPERCELL THAT CAN FORM WITHIN OR JUST AHEAD OF THE SQUALL LINE. ..HALES/GUYER.. 11/30/2006  From swody1 at goshenarc.org Thu Nov 30 19:55:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 30 Nov 2006 14:55:35 -0500 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301957 SWODY1 SPC AC 301955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST THU NOV 30 2006 VALID 302000Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE LWR MS VLY INTO THE MID-SOUTH AND LWR OH VLY... ...LWR MS AND TN VLYS... 19Z SFC ANALYSIS PLACES 1007 MB LOW VCNTY KHOT WITH A COLD FRONT SWD INTO NWRN LA AND ANOTHER FRONT NEWD INTO THE KMEM VCNTY TO THE OH VLY. THE LOW SHOULD BEGIN TO INTENSIFY RAPIDLY THIS AFTN AS THE PRIMARY UPPER LOW APPROACHES WRN OK...WITH A TRACK NEWD TO KMEM BY 06Z AND INTO WRN IND BY 12Z. THE COLD FRONT SHOULD CONTINUE SWEEPING EWD THROUGH THE LWR MS VLY WHILE THE FRONT IN THE OH VLY RETREATS NWWD. DEVELOPMENT OF A LOW-TOPPED QUASI-LINEAR CONVECTIVE SYSTEM (QLCS) APPEARS IMMINENT VCNTY THE COLD FRONT FROM CNTRL AR SWD INTO NRN LA EARLY THIS AFTN. AHEAD OF THE FRONT...18Z RAOBS AND SELECTED ACARS SOUNDINGS SUGGEST THAT LAPSE RATES ARE MARGINAL GIVEN THE WARM LAYER ALOFT. BUT...VSBL SATL SHOWS MODEST INSOLATION OCCURRING THROUGH THE LWR MS VLY INTO THE MID-SOUTH. THIS WILL TEND TO DESTABILIZE THE BOUNDARY LAYER AND LESSEN THE INHIBITION SUFFICIENTLY TO SUPPORT MLCAPES TO AROUND 500 J/KG. THUS...COMBINATION OF STRONG LARGE SCALE ASCENT AND MARGINAL BUOYANCY WILL LIKELY CONTRIBUTE TO INCREASING INTENSITY TO THE QLCS LATE AFTN INTO THE EVE FROM SERN/ECNTRL AR AND NERN LA NEWD INTO THE MID-SOUTH AND LWR OH VLY. PRE-FRONTAL LOW-LEVEL SHEAR PROFILES ARE NOT PARTICULARLY STRONG PRIMARILY DUE TO THE LACK OF DIRECTIONAL SHEAR ABOVE THE SFC. THIS MAY CHANGE DURING THE NEXT SEVERAL HOURS...ESPECIALLY VCNTY THE SFC LOW TRACK. THUS...IT APPEARS THAT DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT...THOUGH ISOLD TORNADOES WILL REMAIN POSSIBLE...MAINLY ACROSS ECNTRL/SERN AR INTO NWRN MS AND WRN TN. THE INCREASING MID-LEVEL FLOW /100+ KTS AT H5/ WILL ENHANCE THE VERTICAL SHEAR...AND IF A SUFFICIENTLY STRONG UPDRAFT CAN EVOLVE...EMBEDDED SUPERCELL STRUCTURES WILL BE POSSIBLE. MORE LIKELY SCENARIO WILL BE FOR BOW ECHO/LEWPS ALONG THE QLCS THAT PRODUCE CORRIDORS OF DAMAGING WINDS. ..RACY.. 11/30/2006