From swody2 at goshenarc.org Sun Oct 1 05:47:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 01 Oct 2006 01:47:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 010546 SWODY2 SPC AC 010545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT SUN OCT 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY INTO THE CNTRL GRTLKS... ...UPR MS VLY TO CNTRL GRTLKS... MAIN BELT OF WLYS WILL BE CONFINED TO SRN CANADA WHERE A MID-LEVEL WAVE WILL TRANSLATE THROUGH THE CANADIAN PRAIRIES. TO THE S...A SUB-TROPICAL JET AND EMBEDDED DISTURBANCES WILL EXIST FROM SRN CA NEWD INTO THE PLAINS. MODELS DISAGREE ON THE AMPLITUDE OF THESE SUB-TROPICAL WAVES. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ACROSS SD ALONG A SWD MOVING COLD FRONT. TO THE S...A LEE TROUGH WILL MOVE EWD INTO NEB AND WRN KS. A MODEST SWLY LLJ WILL BE PRESENT DURING THE NEXT COUPLE OF DAYS...AIMED FROM THE ERN PLAINS TO THE UPPER MS VLY. THIS WILL TRANSPORT MODIFIED GULF MOISTURE NWD BENEATH STEEPENING MID- TROPOSPHERIC LAPSE RATES /EML/. THE STRENGTH OF THE EML WILL MOST LIKELY PRECLUDE SFC-BASED TSTMS ALONG THE LEE-TROUGH AND COLD FRONT OVER THE PLAINS. PARCELS WILL LIKELY CONVECT DOWNSTREAM FROM THE STRONGER CAP ACROSS PARTS OF THE UPPER MS VLY INTO THE CNTRL GRTLKS LATE SUNDAY/EARLY MON. THIS ACTIVITY WILL WEAKEN AS IT TRANSLATE ESEWD DURING MONDAY AFTN. STRONGER INSTABILITY WILL DEVELOP UPSTREAM ACROSS THE CORN BELT/ERN PLAINS MON AFTN. THERMAL RIDGE/CAP MAY DEVELOP NEWD AS FAR AS THE UPPER MS VLY COINCIDENT WITH MODEST BOUNDARY LAYER MSTR. IF LARGE SCALE SUPPORT...TIED TO THE SUB-TROPICAL IMPULSES...IS AS STRONG AS THE NAM...SFC-BASED CONVECTION MAY DEVELOP ALONG THE NOSE OF THE THERMAL RIDGE. OTHERWISE...ELEVATED CONVECTION MAY WAIT UNTIL AFTER DARK TO DEVELOP ALONG THE AXIS OF THE LLJ. IF SFC BASED TSTMS CAN MANAGE TO FORM...POTENTIAL FOR SUPERCELLS WITH LARGE HAIL...DAMAGING WINDS AND TORNADOES WILL EXIT. OTHERWISE...ELEVATED TSTMS WILL PRODUCE LARGE HAIL. GIVEN THE UNCERTAINTY ON OVERALL CONVECTIVE EVOLUTION...FRONTAL PLACEMENTS...MAGNITUDE OF THERMODYNAMICS AND WHETHER UPPER SUPPORT WILL BE SUFFICIENT...HAVE INTRODUCED A LOW-END SLGT CATEGORICAL RISK. ..RACY.. 10/01/2006  From swody2 at goshenarc.org Sun Oct 1 16:50:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 01 Oct 2006 12:50:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 011650 SWODY2 SPC AC 011649 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1149 AM CDT SUN OCT 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER MIDWEST... ...SYNOPSIS... PROGRESSIVE LARGE-SCALE PATTERN IS FORECAST DURING THE DAY TWO PERIOD WITH SEVERAL WEAK PERTURBATIONS EMBEDDED IN BROAD WSWLY FLOW REGIME FROM THE GREAT BASIN INTO THE UPPER MIDWEST. IN THE LOW-LEVELS...SURFACE FRONT WILL SLOWLY SAG SWD THROUGH THE UPPER GREAT LAKES WITH WRN EXTENSION OF THIS BOUNDARY REMAINING QUASI-STATIONARY OR PERHAPS RETREATING NWD SLIGHTLY AS LOW PRESSURE INTENSIFIES OVER NEB. ...UPPER MIDWEST... CLUSTERS OF ELEVATED TSTMS...FOCUSED WITH ZONE OF ENHANCED MOIST/THERMAL ADVECTION ALONG NOSE OF 40-45 KT WSWLY LLJ...WILL LIKELY DEVELOP EWD ACROSS LOWER MI MONDAY MORNING. WHILE VERTICAL SHEAR THROUGH THE CLOUD-BEARING LAYER WILL NOT BE PARTICULARLY STRONG...THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 1000-1500 J/KG MAY SUPPORT SOME MARGINALLY SEVERE HAIL WITH THE MOST INTENSE STORMS. OTHER DIURNAL...SURFACE-BASED STORMS WILL BE POSSIBLE MONDAY AFTERNOON INTO EVENING ALONG SURFACE FRONT SLOWLY PUSHING SWD THROUGH WI. PRESENCE AND/OR TIMING OF ANY SIGNIFICANT SHORT WAVE TROUGHS TO FOCUS THIS CONVECTION REMAINS IN QUESTION ATTM...LEADING TO UNCERTAINTY IN CONVECTIVE EVOLUTION AND INHERENT SEVERE WEATHER THREAT. NONETHELESS...INCREASING BOUNDARY LAYER MOISTURE BENEATH PLUME OF STEEP MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. CAPPING WILL BE AN ISSUE...BUT LATEST MODEL GUIDANCE DOES SUGGEST THAT THE INITIATION OF DEEP...MOIST CONVECTION WILL OCCUR BY MID TO LATE AFTERNOON OVER CNTRL OR SRN WI. VERTICAL SHEAR WILL BE MODEST /I.E. EFFECTIVE BULK SHEARS AOB 30-35 KT/ THOUGH THE DEGREE OF INSTABILITY WILL SUPPORT A FEW SEVERE STORMS CAPABLE OF LARGE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONAL MORE ELEVATED STORMS WILL BE POSSIBLE MONDAY NIGHT WWD INTO SRN MN/NRN IA AS INCREASING NOCTURNAL LLJ ENHANCES CONVERGENCE ALONG SURFACE BOUNDARY. EXISTING CAP WILL REMAIN PROBLEMATIC...THOUGH ISOLATED STORMS APPEAR POSSIBLE WITH A THREAT OF MARGINALLY SEVERE HAIL AND/OR LOCALLY STRONG WIND GUSTS. ..MEAD.. 10/01/2006  From swody2 at goshenarc.org Mon Oct 2 06:09:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 02 Oct 2006 02:09:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 020556 SWODY2 SPC AC 020555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT MON OCT 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS VLY AND CNTRL GRTLKS REGION... ...UPPER MS VLY EWD INTO THE CNTRL GRTLKS... TWO-STREAM FLOW REGIME WILL CONTINUE INTO TUE WITH A SRN STREAM TROUGH EVOLVING ACROSS THE PAC COAST AND A BROAD RIDGE ACROSS THE SRN STATES. WITHIN THE NRN STREAM...A MID-LEVEL WAVE WILL SKIRT ACROSS THE NRN GRTLKS REGION ON TUE WHILE A SUB-TROPICAL IMPULSE...EJECTING AHEAD OF THE WRN COAST TROUGH...MOVES ACROSS THE PLAINS TO THE UPPER MS VLY. THE FRONT ASSOCD WITH THE CANADIAN DISTURBANCE WILL MOVE SWD AND STALL FROM MI TO NEB BY 12Z TUE AS A LOW DEVELOPS OVER IA. THE LOW WILL MOVE NEWD ALONG THE FRONT INTO SERN ONTARIO BY EARLY WED. TRAILING THE LOW...THE FRONT WILL RESUME A SEWD MOVEMENT... REACHING THE MIDWEST...OZARKS AND THE SRN PLAINS BY 12Z WED. A STRONG ELEVATED MIXED LAYER /EML/ HAS SPREAD EWD ACROSS THE PLAINS WITH H7-H5 LAPSE RATES IN EXCESS OF 8 DEG C/KM. THIS STRONG EML WILL CONTINUE TO ADVECT EWD ALONG/S OF THE APPROACHING COLD FRONT THROUGH TUE. AT THE SAME TIME...BOUNDARY LAYER MSTR WILL GRADUALLY INCREASE ACROSS THE PLAINS INTO THE UPPER MS VLY WITH SFC DEW POINTS LIKELY IN THE LWR 60S BY TUE AFTN. MORNING ELEVATED CONVECTION SHOULD WEAKEN AND MOVE EWD OUT OF THE REGION EARLY ON TUE. BUT...AS WEAK LARGE SCALE ASCENT TIED TO THE SUB-TROPICAL DISTURBANCE SPREADS EWD...TSTMS ARE EXPECTED TO DEVELOP OVER PARTS OF THE UPPER MS VLY BY EARLY TUE AFTN. ATTM...GIVEN STRENGTH OF THE EML...MOST TSTMS SHOULD BE ELEVATED ATOP THE RESIDUAL COLD DOME PRODUCED BY MORNING CONVECTION. BUT...IF SUFFICIENT HEATING AND STRONGER THAN ANTICIPATED UPPER SUPPORT MATERIALIZE...THE SFC-BASED TSTM THREAT WILL INCREASE. VERTICAL SHEAR WILL IMPROVE THROUGH THE DAY AND SUPERCELLS WILL BE POSSIBLE. ELEVATED STORM CLUSTERS WILL PRODUCE LARGE HAIL...BUT RISKS FOR DAMAGING WINDS AND TORNADOES WILL INCREASE WITH ANY SFC-BASED STORMS. ACTIVITY WILL MOVE/DEVELOP QUICKLY EWD ACROSS MI AND SRN ONTARIO TUE NIGHT AND POSSIBLY ARRIVE ACROSS THE LWR GRTLKS REGION BY EARLY WED. INSTABILITY AND SUBSEQUENT SEVERE THREATS WILL DECREASE RAPIDLY WITH EWD EXTENT...BUT AN OVERNIGHT THREAT FOR HAIL AND DAMAGING WINDS MAY EXIST UPSTREAM ACROSS THE UPPER MS VLY/MIDWEST. ..RACY.. 10/02/2006  From swody2 at goshenarc.org Wed Oct 4 05:46:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 04 Oct 2006 01:46:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040546 SWODY2 SPC AC 040545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT WED OCT 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...GRT BASIN/INTERMOUNTAIN WEST... UPPER LOW OFF THE CNTRL CA COAST WILL GRADUALLY EDGE EWD TOWARD THE GRT BASIN AND INTERMOUNTAIN WEST ON THU. A 60+ KT BELT OF MID-LEVEL FLOW ASSOC WITH THIS SYSTEM IS EXPECTED ACROSS SRN CA NWD INTO MT. THE LOW HAS BEGUN TO TAP INTO SUB-TROPICAL MOISTURE AND PRECIPITABLE WATER VALUES SHOULD INCREASE LATE WED INTO THU...ESPECIALLY ACROSS THE GRT BASIN AND SWRN DESERTS. EMBEDDED SPEED MAXIMA WITHIN THE WARM CONVEYOR WILL CONTRIBUTE TO CONSIDERABLE CONVECTION. STRONGER STORMS WILL LIKELY FAVOR WRN EDGE OF THE MOIST AXIS ACROSS NRN AZ NWD THROUGH UT INTO ERN ID...THEN SPREAD ENEWD THU NIGHT. STEEP LAPSE RATE ENVIRONMENT COUPLED WITH NEARLY 50 KTS OF VERTICAL SHEAR WILL LIKELY RESULT IN AT LEAST ISOLD STG-SVR TSTMS /INCLUDING A BRIEF SUPERCELL RISK/ WITH DAMAGING WINDS/HAIL. GIVEN THE UNCERTAINTY ON WHEN THE UPPER LOW WILL BEGIN TO EJECT NEWD...A SLGT RISK IS NOT JUSTIFIED ATTM. ..RACY.. 10/04/2006  From swody2 at goshenarc.org Thu Oct 5 05:46:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 05 Oct 2006 01:46:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050546 SWODY2 SPC AC 050545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT THU OCT 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SWRN DESERTS AND GRT BASIN... ...SWRN DESERTS NWD INTO THE GRT BASIN... MODELS HAVE BEEN CONSISTENT DURING PAST SEVERAL RUNS IN EJECTING THE UPPER LOW OFF THE CA COAST NEWD AS AN OPEN WAVE INTO THE GRT BASIN REGION FRI AFTN/EVE. AN EXTENSIVE WARM CONVEYOR WITH A SUB-TROPICAL TAP WILL BE ESTABLISHED ACROSS AZ INTO UT THU AND FRI. SPEED MAXIMA WITHIN THIS BELT OF ENHANCED FLOW ALONG WITH TERRAIN INFLUENCES WILL LIKELY CONTRIBUTE TO CONVECTION OVER A FAIRLY EXTENSIVE AREA FROM THE SWRN DESERTS INTO THE INTERMOUNTAIN WEST DURING THE NEXT COUPLE OF DAYS. AS THE UPPER LOW BEGINS TO EJECT...A 70+ KT SWLY JET STREAK IS EXPECTED TO TRANSLATE FROM SRN CA INTO SRN UT BY FRI AFTN. STRONG MID-LEVEL Q-VECTOR FORCING ASSOC WITH THE JETLET WILL INDUCE A SFC LOW THAT WILL TRACK NWD THROUGH ERN NV. TO THE S OF THE LOW...A FRONT WILL MOVE ENEWD INTO SWRN UT/WRN AZ EARLY FRI AFTN. SUFFICIENT HEATING SHOULD TAKE PLACE ALONG/AHEAD OF THIS FRONT AND JUST TO THE WEST OF THE WARM CONVEYOR INDUCED CLOUDS FOR SCT TSTM INITIATION. VERTICAL SHEAR AOA 50 KTS AND STEEPENING LAPSE RATES ALOFT WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND GUSTS. ISOLD TORNADOES WILL BE POSSIBLE. HIGHEST SEVERE POTENTIAL ATTM APPEARS TO BE ACROSS CNTRL-NRN AZ NWD INTO WRN/CNTRL UT WHERE STRONGEST LARGE SCALE ASCENT WILL OCCUR. THOUGH THE RISK OF SUPERCELLS WILL CONTINUE INTO THE EVE...MAIN STORM MODE SHOULD EVOLVE INTO LINE SEGMENTS/SQUALL-LINE BEFORE WEAKENING OVERNIGHT ACROSS SERN ID...ERN UT AND WRN CO. ...SERN STATES... DIGGING UPPER LOW ALONG THE ATLANTIC COAST WILL INDUCE A LOW JUST OFF THE VA/NC CAPES LATE THU INTO FRI. INCREASING NLY FLOW ON THE BACKSIDE OF THIS LOW WILL FORCE A FRONT SWD ACROSS THE SERN STATES AND INTO NRN FL FRI NIGHT. A FEW TSTMS MAY ACCOMPANY THE FRONT...BUT SOUNDINGS SUGGEST THAT A WARM NOSE IN THE H7-H5 LAYER MAY INHIBIT VIGOROUS UPDRAFTS. MOREOVER...VERTICAL SHEAR WILL BE WEAK...WITH MULTICELL STORMS LIKELY FAVORED OVER ORGANIZED SVR STORMS. OTHERWISE...DEFORMATION TSTMS WILL BE POSSIBLE ACROSS SERN VA/ERN NC FRI NIGHT AS MID-LEVEL INSTABILITY INCREASES. IF THE SFC LOW DEVELOPS CLOSER TO THE COAST...THREAT FOR SFC-BASED STORMS WILL INCREASE OVER THE NC CAPES. BUT...MODELS SO FAR KEEP DEVELOPMENT OFF THE COAST. ..RACY.. 10/05/2006  From swody2 at goshenarc.org Thu Oct 5 17:22:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 05 Oct 2006 13:22:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051722 SWODY2 SPC AC 051721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT THU OCT 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FRI ACROSS PARTS OF THE SRN PLATEAU AND GREAT BASIN.... THE STRONGER BRANCH OF UPPER WESTERLIES WILL REMAIN ZONAL AT HIGHER LATITUDES...NORTH OF THE CANADIAN/U.S. BORDER...THROUGH THIS FORECAST PERIOD...WHILE A WEAKER SOUTHERN BRANCH REMAINS AMPLIFIED FROM THE EASTERN PACIFIC THROUGH THE WESTERN ATLANTIC. AS A VIGOROUS EMBEDDED NORTHERN STREAM SHORT WAVE TROUGH DIGS TO THE LEE OF THE CANADIAN ROCKIES...MODELS CONTINUE TO SUGGEST THAT A SIGNIFICANT IMPULSE WILL LIFT OUT OF THE BASE OF THE WESTERN U.S. TROUGH...NORTHEAST OF THE LOWER COLORADO VALLEY INTO THE NORTH CENTRAL ROCKIES BY EARLY SATURDAY. MEANWHILE...DOWNSTREAM OF A SEASONABLY STRONG CENTRAL STATES RIDGE...A DIGGING SHORT WAVE TROUGH IS PROGGED TO EVOLVE INTO ANOTHER CLOSED LOW OVER THE SOUTHERN MID ATLANTIC REGION. ...INTERMOUNTAIN WEST... MOISTENING FROM THE LOWER LATITUDE EASTERN PACIFIC IS ONGOING ACROSS THE SOUTHERN PLATEAU INTO THE GREAT BASIN...IN ASSOCIATION WITH DEEP LAYER SOUTHERLY FLOW AHEAD OF THE PACIFIC COAST TROUGH. THIS WILL LINGER INTO FRIDAY...AS LARGE-SCALE FORCING INCREASES WITH NORTHEASTWARD ACCELERATION OF SHORT WAVE IMPULSE OUT OF SOUTHERN CALIFORNIA. ALTHOUGH CONCERNS EXIST ABOUT POTENTIAL FOR CONSIDERABLE CLOUD COVER...STEEPENING LAPSE RATES SEEM LIKELY TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR WIDESPREAD CONVECTIVE DEVELOPMENT. EVEN WEAK CAPE...IN THE PRESENCE OF STRONG VERTICAL SHEAR ASSOCIATED WITH A 50-70 KT 500 MB JET STREAK...SHOULD BE SUFFICIENT FOR A FEW STRONG/SEVERE STORMS WITH DAMAGING WIND/HAIL POTENTIAL. ISOLATED SUPERCELLS WITH ASSOCIATED ENHANCED SEVERE THREATS ALSO APPEAR POSSIBLE...PARTICULARLY ACROSS CENTRAL ARIZONA INTO MUCH OF SOUTHERN/EASTERN UTAH...BEFORE STRONGER UPPER FORCING SPREADS NORTHEAST OF THE GREAT BASIN FRIDAY EVENING. ...MID/SOUTH ATLANTIC COAST... A SURFACE FRONT IS EXPECTED TO EXTEND ACROSS THE CAROLINAS THROUGH THE FLORIDA PANHANDLE BY 12Z FRIDAY...WITH A MOIST AIR MASS ALONG/AHEAD OF IT REMAINING SUPPORTIVE OF CONVECTIVE POTENTIAL. THE BEST CHANCE FOR STORMS APPEARS LIKELY TO ACCOMPANY THE EXIT REGION OF A STRONG CYCLONIC MID/UPPER JET STREAK...WHICH IS PROGGED TO SPREAD ACROSS EASTERN NORTH CAROLINA LATE FRIDAY AFTERNOON/EVENING. LOW-LEVEL FLOW IS EXPECTED TO REMAIN WEAK...BUT MODERATE DEEP LAYER SHEAR AND FAVORABLE CONVECTIVE INSTABILITY WILL SUPPORT RISK OF AT LEAST AN ISOLATED STORM OR TWO APPROACHING/EXCEEDING SEVERE LIMITS. ..KERR.. 10/05/2006  From swody2 at goshenarc.org Fri Oct 6 05:35:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 06 Oct 2006 01:35:29 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060535 SWODY2 SPC AC 060534 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 AM CDT FRI OCT 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... HIGHLY AMPLIFIED UPPER AIR PATTERN FCST THROUGH PERIOD...CHARACTERIZED BY LARGE RIDGE OVER NERN PACIFIC...POSITIVELY TILTED TROUGH FROM SASK SWWD ACROSS SRN CA...SYNOPTIC SCALE RIDGE FROM ARKLATEX REGION TOWARD SRN QUE. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AS OPEN-WAVE TROUGH OVER MI/INDIANA/OH -- IS FCST TO DEEPEN AND CLOSE OFF AS IT APCHS CAROLINAS/GA THROUGH DAY-1 INTO DAY-2. THIS IS SOMEWHAT FARTHER S AND W OF EARLIER GUIDANCE...HOWEVER...06/00Z SHORT-RANGE DETERMINISTIC PROGS AND 05/21Z SREF MEMBERS ARE IN REMARKABLY CLOSE AGREEMENT. CONFIDENCE THEREFORE IS STRONG IN SCENARIO OF NEARLY CUT-OFF CYCLONE DRIFTING SWD OVER SC/GA COASTAL REGION DURING DAY-2. THIS PATTERN IS HIGHLY ANOMALOUS...BUT HAS A CLOSE 500 MB ANALOG FROM SEP 19-20 1989. AT SFC...WEAK/ELONGATED AREA OF LOW PRESSURE NOW ANALYZED OVER CAROLINAS PIEDMONT IS EXPECTED TO DEEPEN CONSIDERABLY AND MOVE OFFSHORE GA/SC COAST...IN RESPONSE TO APCHG UPPER LOW. FRONTAL ZONE --- NOW ANALYZED FROM OFFSHORE OUTER BANKS WSWWD ACROSS NRN LA -- WILL MOVE SWD ACROSS MUCH OF CENTRAL/ERN GULF COAST IN RESPONSE TO COASTAL CYCLOGENESIS. WARM FRONTAL SEGMENT WILL REACH NEAR NC COAST. MEANWHILE...UPPER LOW NOW OVER COASTAL CA IS FCST TO EJECT NEWD FROM YELLOWSTONE REGION ACROSS ND DAY-2...AS TROUGH NOW OVER ERN GULF OF AK DIGS SEWD INTO NRN ROCKIES. IN RESPONSE...SFC FRONTOGENESIS/CYCLOGENESIS IS FCST OVER NRN ROCKIES AND NRN HIGH PLAINS...WITH LOW DEEPENING AND MOVING NEWD OVER ND DURING DAY. SECONDARY MID/UPPER SPEED MAX...DIGGING SWD INTO MEAN TROUGH POSITION...WILL RESULT IN UPPER LOW RETROGRADING SWWD ACROSS SRN CA IN WAKE OF EJECTING SYSTEM. ...ERN NC... POTENTIAL FOR SFC-BASED CONVECTION WILL DEPEND STRONGLY ON WHETHER FRONTAL ZONE STAYS OFFSHORE -- PER WRF GUIDANCE AND MOST SREF MEMBERS -- OR REACHES COAST AS INDICATED BY OPERATIONAL NGM/SPECTRAL. CONSENSUS FCST SEEMS MOST REASONABLE ATTM FOR FRONT TO REMAIN JUST OFFSHORE...WITH INTENSE/ELEVATED CONVEYOR OF WARM/MOIST ADVECTION SUPPORTING GEN THUNDER POTENTIAL OVER NERN QUADRANT OF DEEP-LAYER CYCLONE. WRF FRONTAL POSITION DOES REACH CLOSE ENOUGH TO COAST FOR EFFECTIVE PARCELS TO BE NEARLY SATURATED AND SFC-BASED OVER IMMEDIATE SHORELINE AREAS...WITH LARGE LOW LEVEL HODOGRAPHS. SVR POTENTIAL OVER LAND APPEARS TOO ISOLATED/CONDITIONAL FOR CATEGORICAL OUTLOOK ATTM...BUT WILL INTRODUCE MRGL PROBABILITIES FOR IMMEDIATE COASTAL AREAS AND COASTAL WATERS. ...AZ... AS SECONDARY UPPER LOW TAKES SHAPE OVER SRN CA...VERTICAL SHEAR PROFILES ARE EXPECTED TO REMAIN FAVORABLE FOR SUPERCELLS AND BOWS ACROSS MUCH OF THIS REGION THROUGH DAY-2. RELATED LOW LEVEL WAA REGIME WILL CONTINUE TO YIELD RICH MOISTURE ACROSS THIS REGION...THOUGH LOW-MIDLEVEL LAPSE RATES WILL BE WEAK WITHOUT SUBSTANTIAL BOUNDARY LAYER HEATING. MAIN UNCERTAINTY PRECLUDING CATEGORICAL SVR OUTLOOK ATTM IS EXTENT OF DESTABILIZATION IN WAKE OF ABUNDANT CLOUDS/PRECIP LIKELY BETWEEN NOW AND SATURDAY AFTERNOON. ...NRN HIGH PLAINS...NRN ROCKIES... FCST SFC TRAJECTORIES FROM RELATIVELY DRY/CONTINENTAL AIR MASS OVER UPPER MIDWEST SUGGEST MOISTURE WILL BE TOO SCANT FOR SFC-BASED DEVELOPMENT ALONG FRONT OR IN WARM SECTOR. HOWEVER.,..BAND OF WIDELY SCATTERED TO SCATTERED TSTMS MAY OCCUR BEHIND SFC COLD FRONT. THIS AREA WILL BE IN REGION OF STG MIDLEVEL DPVA AND COOLING ALOFT...WITH SOME POTENTIAL FOR AFTERNOON HEATING ALONG E RIM OF CLOUD PLUME. SFC TEMPS IN LOW 70S WOULD YIELD UP TO 700 J/KG MLCAPE OVER ERN MT BY 07/21Z...BASED ON MODIFIED WRF SOUNDINGS. STRONGEST TSTMS MAY PRODUCE HAIL OR DAMAGING GUSTS. ..EDWARDS.. 10/06/2006  From swody2 at goshenarc.org Sat Oct 7 16:47:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 07 Oct 2006 12:47:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071650 SWODY2 SPC AC 071649 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1149 AM CDT SAT OCT 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT WAVE TROUGH...CURRENTLY TRACKING SWD ACROSS CENTRAL CA PER WATER VAPOR IMAGERY...IS EXPECTED TO BECOME A CUT-OFF LOW ALONG THE SRN CA COAST BY END OF DAY 1...AND THEN DRIFT SLOWLY EAST ACROSS SRN CA ON DAY 2. MEANWHILE...DEEPENING UPPER TROUGH AND ASSOCIATED STRENGTHENING SURFACE LOW WILL MOVE THROUGH WRN/NRN ONTARIO TOWARD NRN QUEBEC ON SUNDAY. DOWNSTREAM HEIGHT FALLS ACROSS OH VALLEY AND NERN STATES ARE EXPECTED TO ALLOW CAROLINAS CLOSED LOW TO TRACK SEWD OFF THE SRN ATLANTIC COAST. STRONGEST ASCENT SUPPORTIVE OF A SEVERE THREAT WITH THE CLOSED LOW SHOULD REMAIN OFFSHORE DURING DAY 2 PERIOD...THOUGH WARM CONVEYOR ABOVE SURFACE MAY SUPPORT THUNDERSTORM POTENTIAL OVER COASTAL CAROLINAS AND ADJACENT WATERS IN VICINITY OF COASTAL FRONT. ...SWRN CONUS... INCREASING MID LEVEL FLOW ALONG SERN/ERN PERIPHERY OF SRN CA CLOSED LOW IS EXPECTED TO DEVELOP ACROSS AZ BY 12Z SUNDAY AND THEN SPREAD INTO NM BY SUNDAY EVENING...RESULTING IN STRONG DEEP LAYER SHEAR FOR ORGANIZED STORMS. LARGE SCALE ASCENT AHEAD OF UPPER LOW AND COOLER MID LEVEL TEMPERATURES ATOP PERSISTENT TRANSPORT OF MOISTURE INTO THE SWRN STATES FROM THE LOWER LATITUDE ERN PACIFIC WILL SUPPORT THUNDERSTORMS ACROSS AZ/NM INTO FOUR CORNERS REGION. SURFACE DEWPOINTS IN THE UPPER 40S TO MID 50S SUGGEST INSTABILITY WILL TEND TO BE MARGINAL...THOUGH POCKETS OF MLCAPE UP TO 1000 J/KG MAY DEVELOP WHERE CLOUD BREAKS RESULT IN SUFFICIENT SURFACE HEATING. UNCERTAINTIES IN AVAILABLE INSTABILITY FOR A GREATER SEVERE THREAT PRECLUDE A CATEGORICAL OUTLOOK AT THIS TIME. HOWEVER...POTENTIAL FOR WELL-MIXED/INVERTED-V THERMODYNAMIC PROFILES MAY SUPPORT A FEW DAMAGING WIND GUSTS. ..PETERS.. 10/07/2006  From swody2 at goshenarc.org Sun Oct 8 05:24:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 08 Oct 2006 01:24:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080527 SWODY2 SPC AC 080526 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 AM CDT SUN OCT 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN NM AND FAR W TX.... ...SYNOPSIS... UPPER AIR PATTERN TRANSITION FCST BY END OF PERIOD...AS HEIGHTS RISE ACROSS SERN CONUS AND FALL FROM 4-CORNERS REGION TO UPPER GREAT LAKES. PERSISTENT RIDGING ALOFT -- NOW LOCATED FROM ARKLATEX REGION TO SRN ONT -- WILL WEAKEN AND SHIFT SEWD...AS UPPER LOW NOW OVER SRN CA EVOLVES TO STRONG OPEN-WAVE PERTURBATION AND EJECTS EWD ACROSS AZ...SONORA AND NM. THIS WILL OCCUR IN RESPONSE TO SWD MOVEMENT AND AMPLIFICATION OF SPEED MAX AND ASSOCIATED SHORTWAVE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN BC. OPERATIONAL SHORT-RANGE MODELS AND SREF MEMBERS DISAGREE ON TIMING/STRENGTH OF THESE FEATURES AT MESO-ALPHA SCALE...BUT GENERAL PATTERN BY END OF PERIOD SHOULD BE CHARACTERIZED BY DEEP/CLOSED LOW OVER NRN CA OR NV...STRONG SHORTWAVE TROUGH MOVING EWD ACROSS NM...AND POSITIVELY TILTED NRN-STREAM TROUGH MOVING EWD ACROSS LS AND NRN ONT. WEAK SHORTWAVE TROUGH -- NOW EVIDENT OVER NRN MEX S ELP -- IS PROGGED TO LIFT NEWD FROM NM ACROSS CENTRAL PLAINS DAY-1 THEN WEAKEN OVER UPPER MS VALLEY DAY-2. AT SFC...FRONTAL ZONE NOW ASSOCIATED WITH SERN CONUS LOW WILL BECOME DIFFUSE OVER CENTRAL/WRN GULF COAST REGION...AMIDST SFC RIDGING THAT WILL EXTEND FROM CENTRAL APPALACHIANS SWWD ACROSS SE TX. STRONG COLD FRONT -- NOW ANALYZED FROM NWRN MN SWWD ACROSS SERN SD...CENTRAL NEB...NERN CO -- IS EXPECTED TO MOVE THROUGH GREAT LAKES AND INTO OH VALLEY...OZARKS...WRN OK AND PORTIONS W TX/SERN NM BY 10/00Z. TX-NM FRONTAL SEGMENT MAY BECOME QUASISTATIONARY BY END OF PERIOD...BENEATH STRONG/ELEVATED LOW LEVEL WAA REGIME ASSOCIATED WITH EJECTING CA PERTURBATION. ...SWRN CONUS... SCATTERED TSTMS ARE EXPECTED ACROSS PORTIONS SRN HIGH PLAINS -- PERHAPS INTO SWRN KS -- EARLY IN PERIOD. THIS ACTIVITY MAY MOVE NEWD ACROSS PORTIONS TX PANHANDLE...WRN/NWRN OK AND SWRN KS BEFORE DISSIPATING DURING MID-LATE MORNING HOURS. THIS ACTIVITY WILL BE ASSOCIATED WITH ZONE OF JUXTAPOSED MIDLEVEL DPVA AND LOW LEVEL WAA/MOIST ADVECTION....AHEAD OF EJECTING MEXICAN SHORTWAVE TROUGH. BY START OF PERIOD...ACTIVITY SHOULD BE LARGELY N OF SFC COLD FRONT...SVR POTENTIAL HAVING ENDED DURING PREVIOUS NIGHT. REF SPC DAY-1 OUTLOOK FOR MORE DISCUSSION ON THAT REGIME. BY AFTERNOON...PRIND CLOUD BREAKS AND ASSOCIATED DIURNAL HEATING WILL PERMIT BOUNDARY LAYER TO DESTABILIZE FAVORABLY SW OF SFC COLD FRONT...ACROSS PORTIONS SERN AZ...SRN NM AND FAR W TX. SFC TEMPS UPPER 60S TO MID 70S F AND DEW POINTS LOCALLY 50-55 DEG F ARE EXPECTED...YIELDING MLCAPES 500-1000 J/KG IN MODIFIED WRF SOUNDINGS. EXPECT SFC FLOW TO VEER FROM W-E WITH TIME ACROSS ERN AND ERN AZ JUST AHEAD OF MIDLEVEL WAVE...DIMINISHING VERTICAL SHEAR AND SFC FORCING. ASSOCIATED WIND SHIFT/CONFLUENCE LINE WILL MOVE EWD ACROSS SRN NM/FAR W TX BORDERLAND REGION...COINCIDENT WITH PEAK SFC WARMING AND STRENGTHENING DEEP-LAYER SHEAR. THIS BOUNDARY...ALONG WITH LOCALIZED OROGRAPHIC ASCENT E OF LINE WHERE FLOW COMPONENT IS UPSLOPE...WILL PROVIDE SUFFICIENT LIFT BENEATH 45-55 KT 500 MB JET. FCST KINEMATIC PROFILES SUGGEST UP TO 70 KT 0-6 KM SHEAR AND -- FOR RIGHT-MOVING STORMS -- 100-150 J/KG OF 0-1 KM SRH POSSIBLE. THIS WILL SUPPORT POTENTIAL FOR SUPERCELLS AND SMALL BOWS TO DEVELOP. AFTER DARK...BULK OF CONVECTION WILL MOVE OVER SFC AIR MASS THAT WILL BE STABILIZED BY DIABATIC COOLING AND/OR POSTFRONTAL CAA. HOWEVER...STRONG MOISTURE TRANSPORT AND ISENTROPIC ASCENT ABOVE STABLE SFC LAYER MAY SUPPORT MRGL SVR POTENTIAL EWD/NEWD TOWARD PORTIONS SERN NM AND PERMIAN BASIN REGION OF W TX. ..EDWARDS.. 10/08/2006  From swody2 at goshenarc.org Sun Oct 8 17:12:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 08 Oct 2006 13:12:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081715 SWODY2 SPC AC 081714 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1214 PM CDT SUN OCT 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN NM AND FAR W TX... ...SYNOPSIS... CLOSED MID/UPPER LEVEL LOW...NOW LOCATED OVER SRN CA COAST PER WATER VAPOR IMAGERY...IS PROGGED TO EJECT EWD ACROSS NRN SONORA/AZ INTO NM DURING DAY 2 AS UPSTREAM SRN BRITISH COLUMBIA IMPULSE DIGS SWWD FROM NRN INTERMOUNTAIN REGION...REACHING NRN CA/WRN NV BY 12Z TUESDAY. IN THE LOW LEVELS...COLD FRONT ASSOCIATED WITH STORM SYSTEM TRACKING E ACROSS ERN CANADA MONDAY IS EXPECTED TO MOVE SWD INTO OH VALLEY... THE OZARKS REGION...AND SRN PLAINS. WRN EXTENT OF THIS BOUNDARY SHOULD BECOME QUASISTATIONARY ACROSS W TX/SRN NM...ESPECIALLY BY END OF PERIOD...GIVEN DEVELOPMENT OF STRONG LOW LEVEL WAA REGIME ASSOCIATED WITH EJECTING CA SHORT WAVE TROUGH. ...SWRN CONUS... SURFACE DEWPOINTS IN THE 50S LOCATED S OF THE FRONT IN NM COMBINED WITH SURFACE HEATING SHOULD RESULT IN MLCAPE VALUES RANGING FROM 500-1000 J/KG MONDAY AFTERNOON AND EARLY EVENING TIME PERIOD. SURFACE FLOW IS EXPECTED TO VEER WITH TIME ACROSS SRN/ERN AZ...AS CA SHORT WAVE TROUGH ADVANCES EWD...WITH SURFACE WIND SHIFT/GREATEST LOW LEVEL CONVERGENCE INTO SWRN NM AND FAR W TX BY PEAK HEATING. INCREASING ASCENT AHEAD OF CA IMPULSE AND IN EXIT REGION OF ACCOMPANYING 60-65 SWLY MID LEVEL JET EXPECTED TO SUPPORT THUNDERSTORM DEVELOPMENT MONDAY AFTERNOON ACROSS SRN NM/FAR W TX AND POTENTIALLY AS FAR W AS SERN AZ BENEATH COLDER MID LEVEL TEMPERATURES. DESPITE MARGINAL INSTABILITY...STRONG UPPER FORCING AND EFFECTIVE BULK SHEAR VALUES OF 40-50 KT SUGGEST A POTENTIAL FOR ORGANIZED STORMS INCLUDING SUPERCELLS AND BOWING SEGMENTS. LOW LEVEL JET ACROSS W TX IS EXPECTED TO STRENGTHEN MONDAY NIGHT... AND WILL LIKELY MAINTAIN THUNDERSTORM ACTIVITY EWD INTO SERN NM AND ADJACENT PARTS OF W TX ATOP STABLE POST-FRONTAL AIR MASS WHERE WAA/ISENTROPIC ASCENT WILL BE MAXIMIZED. WEAK INSTABILITY AND SUFFICIENT EFFECTIVE BULK SHEAR VALUES SUGGEST AN ISOLATED SEVERE THREAT. ..PETERS.. 10/08/2006  From swody2 at goshenarc.org Tue Oct 10 06:11:09 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 10 Oct 2006 02:11:09 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100613 SWODY2 SPC AC 100613 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0113 AM CDT TUE OCT 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL GULF COAST REGION TO OH/WRN PA... ...SYNOPSIS... SIGNIFICANT PATTERN SHIFT UNDERWAY...AS UPPER LOW NOW INTENSIFYING OVER NRN NV RETROGRADES OFFSHORE CA. ANOTHER UPPER LOW -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER FAR NRN MB -- WILL DIG SWD...PHASE WITH OTHER SHORTWAVE PERTURBATIONS -- AND ENLARGE/INTENSIFY MARKEDLY. BY END OF DAY-2 PERIOD...THIS PROCESS WILL RESULT IN LARGE...DEEP...COLD CYCLONIC VORTEX COVERING MOST OF CENTRAL/ERN CONUS AND CENTERED OVER UPPER GREAT LAKES. SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN NM -- IS FCST TO EJECT EWD AND DEAMPLIFY DAY-1...AMIDST STRENGTHENING LARGE SCALE HEIGHT GRADIENTS ASSOCIATED WITH DIGGING POLAR VORTEX. AT SFC...FRONTAL ZONE NOW ANALYZED FROM NY...SWWD OVER OH AND OZARKS TO SW TX -- WILL BE OVERCOME BY INTENSE/SECONDARY COLD FRONTAL SURGE DURING THIS PERIOD. ASSOCIATED SFC CYCLOGENESIS SHOULD OCCUR OVER UPPER MS VALLEY REGION BY 11/12Z...WITH RESULTANT CYCLONE LIFTING NEWD ACROSS LS/UPPER MI REGION INTO ONT...BECOMING VERTICALLY STACKED WITH MIDLEVEL VORTEX...AND OCCLUDING. BY END OF PERIOD...SFC COLD FRONT SHOULD EXTEND FROM SWRN QUE OR SERN ONT...SWD ACROSS CAROLINAS...THEN SWWD ACROSS DEEP S TX. SREF DATA UNAVAILABLE...AND SPECTRAL MODEL STILL APPEARS TO BE TOO SLOW WITH COLD FRONT OVER TX. HOWEVER...PREVIOUSLY TOO-AGGRESSIVE OPERATIONAL WRF HAS SLOWED CONSIDERABLY IN 24 HOURS AND IS CLOSER TO ECMWF/UKMET CONSENSUS...WHICH REMAINS FAVORED FRONTAL SCENARIO. ...OH VALLEY TO CENTRAL GULF COAST... SCATTERED TSTMS IN BANDS AND CLUSTERS SHOULD FORM WITHIN OUTLOOK AREA DURING DAYLIGHT HOURS...MAIN SVR RISK BEING DAMAGING GUSTS. SVR POTENTIAL SHOULD DIMINISH CONSIDERABLY AFTER DARK...PARTICULARLY FROM TN NWD...AS ALREADY MRGL INSTABILITY WEAKENS. SFC-BASED CAPE WILL BE LIMITED ACROSS MUCH OF THIS AREA BY COMBINATION OF WEAK MIDLEVEL LAPSE RATES -- JUST ABOVE MOIST-ADIABATIC -- AND PRESENCE OF CLOUD COVER TO LIMIT SFC SOLAR HEATING. HOWEVER...EXPECT CINH TO BE WEAK AS WELL...PERMITTING CONVECTION TO DEVELOP IN ONE OR MORE LINEAR ZONES OF FAVORABLE CONVERGENCE ALONG/AHEAD OF SFC COLD FRONT. IN OH VALLEY/LE REGION...WEAK MIDLEVEL ASCENT -- ASSOCIATED WITH EJECTING REMAINS OF CURRENT SWRN TROUGH -- MAY PROVIDE SOME COOLING ALOFT IN SUPPORT OF CONVECTION. FCST SOUNDINGS SUGGEST ABOUT 30 DEG MEAN WIND COMPONENT ACROSS FRONTAL ZONE IS POSSIBLE...SUPPORTING NARROW BAND OF CONVECTION MOVING NEWD INTO ENVIRONMENT OF SFC DEW POINTS MID-UPPER 50S...AND AROUND 500 J/KG MLCAPES. PREFRONTAL LOW LEVEL FLOW GENERALLY SHOULD VEER WITH SWD EXTENT...RELATED TO INCREASING DISTANCE FROM LARGEST PRESSURE FALLS THAT ARE FCST TO OCCUR AHEAD OF EJECTING SFC CYCLONE. HOWEVER...GIVEN STRENGTH OF GRADIENT FLOW ALOFT...DEEP-LAYER SHEAR STILL WILL BE FAVORABLE FOR SVR. PRIND SFC MOISTURE AND POTENTIAL FOR AREAS OF DIABATIC HEATING WILL INCREASE SWD. NEARLY UNIDIRECTIONAL DEEP-LAYER WIND PROFILES ARE FCST...SUPPORTING MORE MULTICELLULAR/LINEAR MODES...ALTHOUGH ANY DISCRETE DEVELOPMENT WILL HAVE SUPERCELL POTENTIAL. RELATIVE MIN IN SVR POTENTIAL MAY EXIST BETWEEN OH VALLEY AND GULF STATES REGIMES...WHERE CONVERGENCE AND HEATING EACH REMAIN RELATIVELY WEAK...HOWEVER THIS IS TOO UNCERTAIN AND MESOSCALE DEPENDENT TO WARRANT BREAKING OUTLOOK INTO TWO DISTINCT CATEGORICAL AREAS ATTM. ...COASTAL/TIDEWATER VA/NC... WIDELY SCATTERED TO SCATTERED TSTMS MAY DEVELOP OVER PORTIONS OF THIS REGION -- SFC-BASED DURING DAYLIGHT HOURS ALONG/S OF FRONT. MID-UPPER LEVEL GRADIENT FLOW IS FCST TO STRENGTHEN WITH TIME IN TANDEM WITH SFC HEATING...WHILE LOW LEVEL MOIST ADVECTION FROM ATLANTIC MAINTAINS/INCREASES BOUNDARY LAYER MOISTURE. MEANWHILE...ALTHOUGH LOW LEVEL WINDS ARE FCST TO REMAIN RATHER WEAK IN WARM SECTOR -- GENERALLY 10 KT OR LESS -- FLOW SHOULD BE SLIGHTLY STRONGER AND SOMEWHAT BACKED IN SFC FRONTAL ZONE. THIS COMBINATION OF FACTORS SUGGESTS AT LEAST MRGL SVR POTENTIAL WITH A FEW TSTMS. ..EDWARDS.. 10/10/2006  From swody2 at goshenarc.org Tue Oct 10 17:28:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 10 Oct 2006 13:28:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101731 SWODY2 SPC AC 101729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT TUE OCT 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE OH VALLEY... ...SYNOPSIS... UPPER PATTERN WILL UNDERGO SIGNIFICANT AMPLIFICATION THIS PERIOD. THE SHORTWAVE TROUGH NOW OVER WRN KS WILL DEAMPLIFY AND EJECT RAPIDLY NEWD INTO THE OH VALLEY BY EARLY WEDNESDAY AS A LARGE UPPER TROUGH AMPLIFIES SSEWD THROUGH THE MS...OH AND TN VALLEYS. SEVERAL JET STREAKS AND ATTENDANT VORTICITY MAXIMA WILL ROTATE THROUGH THE UPPER TROUGH. STRONG CYCLOGENESIS WILL ACCOMPANY THIS FEATURE WITH A SURFACE LOW FORECAST OVER THE UPPER GREAT LAKES WEDNESDAY MORNING. THIS LOW WILL DEEPEN AS IT LIFTS NWD INTO SRN ONTARIO DURING THE DAY. TRAILING COLD FRONT WILL SWEEP EWD AND SEWD THROUGH THE OH AND TN VALLEYS THIS PERIOD. SWRN PORTION OF THIS BOUNDARY WILL LIKELY STALL ACROSS S TX. ...CNTRL/NRN AL AND GA...TN VALLEY THROUGH THE OH VALLEY AREA... SLY LOW LEVEL JET IS FORECAST TO STRENGTHEN OVER THE TN AND OH VALLEYS AND GREAT LAKES IN ASSOCIATION WITH DEEPENING SURFACE LOW AND AMPLIFYING UPPER TROUGH. OBSERVATIONS SHOW BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 50S FROM THE OH VALLEY SWD TO NEAR THE CNTRL GULF COAST. HIGHER DEWPOINTS ARE CONFINED TO SERN TX AND THE WRN GULF. GIVEN THAT THE LOW LEVEL JET WILL REMAIN DISPLACED FROM THE RICHER MOISTURE SOURCE...MOISTURE ADVECTION WILL BE LIMITED. WIDESPREAD CLOUDS WILL LIKELY SPREAD INTO MUCH OF THE OH AND TN VALLEY EARLY WEDNESDAY AND LIMIT OR DELAY HEATING. POTENTIAL FOR SOME HEATING WILL EXIST DURING THE LATE MORNING INTO THE AFTERNOON IN WAKE OF LEAD VORT MAX AS MID LEVEL DRY SLOT ADVANCES EWD. DESPITE LIMITED LOW LEVEL MOISTURE...SOME DESTABILIZATION MAY OCCUR AS A RESULT OF MID LEVEL COOLING ACCOMPANYING THE AMPLIFYING UPPER TROUGH AND WHERE ENOUGH CLOUD BREAKS ALLOW THE BOUNDARY LAYER TO WARM. STILL MLCAPE SHOULD REMAIN MARGINAL AND GENERALLY AOB 800 J/KG FROM THE TN INTO THE OH VALLEY. A FEW STORMS WILL LIKELY BE ONGOING OVER THE OH VALLEY EARLY WEDNESDAY IN ASSOCIATION WITH DEAMPLIFYING LEAD VORT MAX. POTENTIAL WILL EXIST FOR SOME DESTABILIZATION IN WAKE OF THIS ACTIVITY. ADDITIONAL STORMS MAY DEVELOP FROM THE OH VALLEY INTO THE TN VALLEY WITHIN ZONE OF FRONTAL FORCING AS A SECONDARY VORT MAX ROTATES THROUGH BASE OF UPPER TROUGH AND WHERE AN AXIS OF MARGINAL SBCAPE COULD DEVELOP. THESE STORMS WILL EXIST IN AN ENVIRONMENT WITH STRONG LARGELY UNIDIRECTIONAL SSWLY WIND PROFILES ACCOMPANYING THE INTENSIFYING LOW-MID LEVEL JETS. POTENTIAL WILL EXIST FOR LINE SEGMENTS WITH LEWP/BOWING STRUCTURES CAPABLE OF MAINLY DAMAGING WIND. SOME EMBEDDED SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE...BUT MORE CONDITIONAL UPON DEGREE OF INSTABILITY. OVERALL THREAT APPEARS SOMEWHAT MARGINAL DUE TO POTENTIAL LIMITING FACTORS UPON THE THERMODYNAMIC ENVIRONMENT. ...CNTRL GULF COASTAL AREA... SLIGHTLY HIGHER INSTABILITY MAY DEVELOP IN THIS AREA DUE TO SLIGHTLY BETTER LOW LEVEL MOISTURE. MCS CURRENTLY OVER SERN TX MAY CONTINUE INTO THE NRN GULF EARLY WEDNESDAY. CONVECTIVE DEBRIS FROM THIS SYSTEM COULD LIMIT HEATING NEAR THE COAST. MID-UPPER FLOW WILL REMAIN QUITE STRONG IN THIS REGION RESULTING IN FAVORABLE DEEP LAYER SHEAR FOR ORGANIZED STORMS. HOWEVER...LOW LEVEL FLOW IS FORECAST TO VEER AND WEAKEN EARLY IN THE PERIOD AS THE PRIMARY LOW LEVEL JET AND CYCLOGENESIS DEVELOP WELL N. THIS SUGGESTS LOW LEVEL CONVERGENCE WILL BE WEAK...AND CONVECTIVE COVERAGE SHOULD REMAIN QUITE ISOLATED. ..DIAL.. 10/10/2006  From swody2 at goshenarc.org Sat Oct 14 05:59:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 14 Oct 2006 01:59:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140601 SWODY2 SPC AC 140600 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT SAT OCT 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN/SERN TX AND SRN LA... ...SYNOPSIS... GENERALLY FAST MID/UPPER LEVEL FLOW OF MODEST AMPLITUDE WILL PERSIST ACROSS MUCH OF THE NATION THROUGH SUNDAY. FIRST DISTURBANCE RESPONSIBLE FOR POTENTIALLY STRONG CONVECTIVE DEVELOPMENT THROUGH THE DAY 2 PERIOD WILL BE THE MID/UPPER LEVEL LOW CURRENTLY SPINNING TOWARD SRN CA. THERE CONTINUE TO BE TIMING AND AMPLITUDE DIFFERENCES WITH THIS SYSTEM AMONG THE LATEST DETERMINISTIC GUIDANCE. THROUGH LATE SUNDAY...GFS CONTINUES TO SUGGEST A MORE PROGRESSIVE AND LESS AMPLIFIED UPPER TROUGH COMPARED TO NAM-WRF. SREF MEAN APPEARS TO BE A REASONABLE COMPROMISE WITH THE HANDLING OF THIS SYSTEM AND SUGGESTS THE MID/UPPER LOW WILL OPEN UP WHILE DEVELOPING ESEWD FROM THE LOWER CO RIVER VALLEY TO NRN MEX AND THE UPPER RIO GRANDE VALLEY THROUGH EARLY MONDAY. A BELT OF INTENSIFYING SWLY MID LEVEL FLOW WILL PRECEED THE SOUTHWEST/NRN MEX TROUGH. THIS STRONG FLOW WILL EXTEND FROM NRN MEX ACROSS THE SRN PLAINS AND NWRN GULF. A SECOND DISTURBANCE OF CONCERN IS FORECAST TO EMANATE FROM THE LOWER LATITUDES AND LIFT NEWD ALONG/NEAR THE TX GULF COAST EMBEDDED WITHIN THE LARGE SCALE SWLY FLOW. WHILE MODEL TIMING DIFFERENCES WITH THIS FEATURE ARE ALSO LARGE...THERE IS STRONG CONSENSUS THAT PRONOUNCED WARM AIR ADVECTION AND RESULTANT ASCENT WILL EXIST COINCIDENT WITH A VERY MOIST AIR MASS ACROSS THE NWRN GULF...AND POSSIBLY INLAND ACROSS THE TX/LA COASTAL PLAINS. ...TX/LA GULF COAST... MOISTURE AND MASS TRANSPORT SHOULD INCREASE STEADILY THROUGH SUNDAY ALONG THE TX GULF COAST WHERE A COASTAL/WARM FRONT MAY DEVELOP INLAND ACROSS PARTS OF THE COASTAL PLAIN GIVEN INTENSIFYING LOW LEVEL SLY FLOW. LIFT ACROSS THE BOUNDARY MAY BE ENHANCED BY THE APPROACH OF THE SOUTHWEST/NRN MEXICO TROUGH...AND/OR BY LOWER AMPLITUDE IMPULSES EJECTING NNEWD FROM MEX. SURFACE DEWPOINTS IN THE LOW TO MID 70S...WEAK CAP...AND STRONG FORCING WILL ALL CONTRIBUTE TO WIDESPREAD DEEP CONVECTION ACROSS THE REGION. POTENTIALLY WIDESPREAD NATURE OF CLOUDS AND PRECIPITATION MAY TEND TO LIMIT GREATER SURFACE-BASED DESTABILIZATION INLAND FROM THE GULF. HOWEVER...FORECAST MAGNITUDE OF FORCING AND SHEAR ACROSS THE REGION MAY COMPENSATE FOR RELATIVELY LOW CAPE/WEAK LAPSE RATE ENVIRONMENT AND LEAD TO SUPERCELLS WITH A WIND AND TORNADO THREAT...EMBEDDED WITHIN A LARGER CONVECTIVE PRECIPITATION SHIELD. ...RIO GRANDE VALLEY... WARM AIR ADVECTION AND DESTABILIZATION WILL LIKELY OCCUR ACROSS PARTS OF NM AND WRN/CNTRL TX THROUGH SUNDAY AFTERNOON AND EVENING AS STRONG MID/UPPER TROUGH DEVELOPS EWD. WARM FRONT WILL ALSO LIFT ACROSS THE REGION BUT RAPID WARM SECTOR DEVELOPMENT MAY BE INHIBITED BY CLOUDS/PRECIPITATION. IN ADDITION TO STRONG ASCENT ON THE COOL SIDE OF THE BOUNDARY ACROSS TX...LIFT AND LAPSE RATES NEAR THE UPPER TROUGH MAY MARGINALLY SUPPORT HAIL FROM A FEW STORMS IN NM. SURFACE-BASED WARM SECTOR ACTIVITY APPEARS POSSIBLE OVER WEST TX AND NEARER THE RIO GRANDE AS UPPER TROUGH APPROACHES AND POSSIBLE DRYLINE SHARPENS THROUGH LATE IN THE DAY. UNCERTAINTY IN TROUGH TIMING AND STRENGTH OF INSTABILITY PRECLUDE HIGHER SEVERE PROBABILITIES ACROSS THE AREA AT THIS TIME. ..CARBIN.. 10/14/2006  From swody2 at goshenarc.org Sat Oct 14 17:20:33 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 14 Oct 2006 13:20:33 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141722 SWODY2 SPC AC 141721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SAT OCT 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS ALONG THE TX AND LA GULF COASTAL AREAS... ...TX/LA GULF COAST... SOUTHWEST FLOW ALOFT WILL REMAIN IN PLACE ACROSS THE SRN PLAINS AND WRN GULF COAST STATES AS AN UPPER-LOW MOVES SLOWLY ESEWD ACROSS AZ SUNDAY. AT THE SFC...A NEARLY STATIONARY FRONT ACROSS FAR SOUTH TX WILL LIFT NWD ALONG THE TX COAST AS A WARM FRONT SUNDAY. IN RESPONSE TO THE APPROACHING UPPER-LEVEL SYSTEM...LOW-LEVEL MOISTURE WILL RETURN QUICKLY NWD AS A 70 KT LOW-LEVEL JET INTENSIFIES ACROSS EAST AND NORTH TX SATURDAY AFTERNOON. LIFT FROM THE LOW-LEVEL JET AND STRONG CONVERGENCE ALONG THE WARM FRONT SHOULD RESULT IN THE DEVELOPMENT OF A LARGE MCS ACROSS SOUTH TX SUNDAY MORNING WITH THE MCS EXPANDING NWD ACROSS CNTRL AND SOUTHEAST TX DURING THE AFTERNOON. FORECAST SOUNDINGS FOR SUNDAY ALONG THE TX GULF COAST SHOW VEERING WINDS WITH HEIGHT RESULTING IN 0-1 KM SHEAR VALUES IN THE 20 TO 30 KT RANGE. THIS STRONG LOW-LEVEL SHEAR SHOULD BE FAVORABLE FOR ROTATING STORMS WITH TORNADO POTENTIAL ESPECIALLY CONSIDERING SFC DEWPOINTS WILL BE IN THE LOWER TO MID 70S F. THE THREAT SHOULD GRADUALLY EXPAND NORTH AND EWD DURING THE DAY AFFECTING SRN LA BY EVENING. ALTHOUGH LESS OF A THREAT...DAMAGING WINDS WILL ALSO BE POSSIBLE WITH ROTATING CELLS ESPECIALLY IN AREAS WITH LOCALLY ENHANCED INSTABILITY. ...ERN NM/WEST TX... AN UPPER-LOW OVER SRN CA TONIGHT WILL MOVE EWD ACROSS AZ SUNDAY AS A STRONG 70 KT LOW-LEVEL JET DEVELOPS ACROSS THE SRN PLAINS. THIS WILL INCREASE LOW-LEVEL MOISTURE NWD ACROSS CNTRL AND WEST TX SUNDAY WITH SFC DEWPOINTS POSSIBLY REACHING THE MID 60S F AS FAR NWWD AS THE SRN TX PANHANDLE. THIS COMBINED WITH LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-LEVEL TROUGH SHOULD RESULT IN THE DEVELOPMENT OF AN MCS ACROSS WEST TX AND PARTS OF ERN NM DURING THE AFTERNOON. HOWEVER...THE NAM AND GFS SOLUTIONS DISAGREE ON CONVECTIVE COVERAGE KEEPING THE STRENGTH OF THE CONVECTION HIGHLY UNCERTAIN. IF STORM COVERAGE REMAINS LESS AND MORE INSTABILITY DEVELOPS AS SUGGESTED BY THE GFS...A THREAT FOR HAIL AND STRONG GUSTY WINDS MAY MATERIALIZE SUNDAY AFTERNOON ACROSS THE REGION. ..BROYLES.. 10/14/2006  From swody2 at goshenarc.org Sun Oct 15 06:12:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 15 Oct 2006 02:12:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150612 SWODY2 SPC AC 150611 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0111 AM CDT SUN OCT 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX GULF COAST ACROSS THE LOWER MS VALLEY AND THE NRN GULF COAST... ...SYNOPSIS... POTENTIAL FOR SEVERE STORMS AND PERHAPS TORNADOES APPEARS TO BE INCREASING OVER PARTS OF THE NRN GULF COAST AND MS DELTA REGIONS DURING MONDAY AS A VIGOROUS SHORT WAVE IMPULSE EJECTS NEWD FROM THE SRN PLAINS. THIS WILL OCCUR DOWNSTREAM FROM STRONG HEIGHT FALLS AND LARGE SCALE TROUGH DEVELOPMENT FROM THE NORTHWEST/GREAT BASIN AREAS TO THE ROCKIES. RIDGING...SURFACE AND ALOFT...WILL REMAIN SITUATED ACROSS THE ERN SEABOARD...AND OVER FL AND THE ERN GULF OF MEX. THERE CONTINUE TO BE TIMING DIFFERENCES AMONG NAM-WRF AND GFS GUIDANCE WITH RESPECT TO THE EJECTING SHORT WAVE TROUGH. THE GFS CONTINUES TO FORECAST A MORE PROGRESSIVE IMPULSE AND LATEST NAM-WRF GUIDANCE IS TRENDING TOWARD A LESS AMPLIFIED UPPER WAVE...SIMILAR TO WHAT THE GFS HAS BEEN FORECASTING. ECMWF AND SREF MEAN ALSO SUGGEST THAT THE SHORT WAVE TROUGH WILL DEAMPLIFY WHILE ACCELERATING NEWD FROM TX/OK TO THE MIDWEST FROM MONDAY AFTERNOON THROUGH EARLY TUESDAY. LARGE SCALE FORCING ASSOCIATED WITH THE WRN U.S. TROUGH WILL INDUCE STRONG CYCLOGENESIS ACROSS THE NRN PLAINS THROUGH THE PERIOD. MEANWHILE...VERY STRONG WIND FIELDS ACCOMPANYING THE EJECTING SRN PLAINS TROUGH WILL ALLOW WARM SECTOR TO EXPAND NNEWD FROM THE UPPER TX COAST ACROSS THE LOWER MS VALLEY THROUGH THE PERIOD. ...ERN TX ACROSS THE LOWER MS VALLEY... PRONOUNCED GULF MOISTURE TRANSPORT WILL PRECEDE THE EJECTING UPPER TROUGH WITH INTENSIFYING SLY LOW LEVEL JET OF 50KT TO 70KT EXTENDING FROM THE NWRN GULF INLAND TO THE OZARKS DURING MONDAY. INTENSE DYNAMIC ASCENT ACROSS DEVELOPING WARM SECTOR WILL SUPPORT WIDESPREAD CONVECTION OVER THE REGION OF CONCERN. LATEST GUIDANCE SUGGESTS WARM SECTOR WITH 70S DEWPOINTS SHOULD EXPAND NWD AND EWD FROM ERN TX TO SRN AR...AND INTO TO MS FROM MONDAY MORNING THROUGH MONDAY NIGHT. DESPITE NEARLY MOIST ADIABATIC LAPSE RATES DEPICTED IN FORECAST SOUNDINGS...POCKETS OF WEAK TO MODEST INSTABILITY MAY DEVELOP DURING THE DAY AND SUPPORT STRONGER EMBEDDED CONVECTION. ACTIVITY NEAR THE WARM FRONT...AND NEAR ANY WEAK FRONTAL WAVES...WILL ENCOUNTER EXTREME LOW LEVEL SHEAR AND HELICITY. EFFECTIVE SRH VALUES IN EXCESS OF 500 M2/S2 WILL EASILY SUPPORT MESOCYCLONE FORMATION AND PERSISTENCE IN ANY UPDRAFTS THAT CAN REMAIN DISCRETE/LONG-LIVED. INITIALLY...ROTATING STORMS OR FAST-MOVING LINE SEGMENTS MAY REMAIN ROOTED ABOVE THE BOUNDARY LAYER...OR CROSS INTO MORE STABLE AIR MASS NORTH OF THE WARM FRONT. HOWEVER...WITH TIME...SUFFICIENT SURFACE-BASED DESTABILIZATION APPEARS POSSIBLE ACROSS THE WARM SECTOR TO SUPPORT SUPERCELLS...AND POSSIBLY LINE SEGMENTS...WITH TORNADO AND WIND DAMAGE POTENTIAL. INCREASINGLY STRONG FLOW THROUGH THE TROPOSPHERE WILL ALSO RESULT IN FAST STORM MOTION AND AN ENHANCED THREAT OF DAMAGING WINDS. AT PRESENT...GREATEST RISK APPEARS TO BE FROM ERN TX ACROSS LA AND INTO WRN MS THROUGH MONDAY NIGHT. RAPID TRANSLATION OF THE UPPER TROUGH ALSO NECESSITATES A LARGE SLGT RISK AREA GIVEN FAST STORM MOTION. PARTS OF THE REGION MAY REQUIRE HIGHER PROBABILITIES IN LATER OUTLOOKS AS DETAILS BECOME MORE CERTAIN. ..CARBIN.. 10/15/2006  From swody2 at goshenarc.org Sun Oct 15 17:22:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 15 Oct 2006 13:22:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151725 SWODY2 SPC AC 151724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT SUN OCT 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF EAST TX...LA..MS AND SRN AR... ...EAST TX/LA/MS AND SRN AR... AN UPPER-LOW OVER THE SRN ROCKIES TONIGHT IS FORECAST TO OPEN AND ADVANCE EWD INTO WEST TX MONDAY. IN RESPONSE...A VERY STRONG LOW-LEVEL JET WILL CONTINUE TO STRENGTHEN ACROSS EAST TX...WRN LA AND WRN AR WITH THE JET LIKELY REACHING 80 KT BY MONDAY AFTERNOON. IN ADDITION...WIDESPREAD LOW-LEVEL CONVERGENCE AND ISENTROPIC LIFT WITH THE LOW-LEVEL JET WILL SUPPORT A LARGE TROPICAL-LIKE MCS WHICH SHOULD GRADUALLY SPREAD NNEWD ACROSS EAST TX...WRN LA...SRN AR AND INTO WRN MS DURING THE DAY. FORECAST SOUNDINGS VALID AT 12Z MONDAY IN THE HOUSTON...BEAUMONT...LUFKIN AND LAKE CHARLES AREAS SHOW 55 TO 65 KT OF SLY FLOW AT 850 MB AND VEERING WINDS WITH HEIGHT SUGGESTING A TORNADO THREAT WILL BE ONGOING ACROSS EAST TX AND SWRN LA MONDAY MORNING. AS THE LOW-LEVEL JET INTENSIFIES AND THE LARGE MCS DRIFTS NNEWD...THE TORNADO THREAT SHOULD EXPAND INTO NRN LA...SRN AR AND WRN MS BY AFTERNOON. ANOTHER FACTOR THAT MAY INCREASE THE SEVERE THREAT LATE TONIGHT INTO MONDAY IS A MID-LEVEL JET THAT IS FORECAST TO DEVELOP ACROSS THE REGION. IN RESPONSE TO THE DEVELOPING JET...0-6 KM SHEAR WILL STEADILY INCREASE TO ABOUT 40 TO 45 KT IN EAST TX AND WRN LA BY MIDDAY SUNDAY. THIS SHOULD HELP ROTATING STORMS TO PERSIST LONGER AND A WIND DAMAGE THREAT MAY ALSO OCCUR IN ADDITION TO THE TORNADO THREAT. ...WCNTRL TX... AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE EWD INTO THE SRN PLAINS MONDAY. IN RESPONSE...FRONTOGENESIS MAY TAKE PLACE ACROSS WCNTRL TX BY MONDAY AFTERNOON. SFC HEATING...INCREASING LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY AND STRONG LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH SHOULD RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT. ALTHOUGH INSTABILITY IS FORECAST TO REMAIN RELATIVELY WEAK...COOLING TEMPS ALOFT...STRONG VERTICAL SHEAR AND STEEPENING MID-LEVEL LAPSE RATES MAY RESULT IN A MARGINAL HAIL THREAT WITH THE STRONGER THUNDERSTORMS THAT DEVELOP MONDAY AFTERNOON. ..BROYLES.. 10/15/2006  From swody2 at goshenarc.org Mon Oct 16 05:11:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 16 Oct 2006 01:11:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160513 SWODY2 SPC AC 160512 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1212 AM CDT MON OCT 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG SHORT WAVE TROUGH CURRENTLY MOVING ACROSS THE PACIFIC NORTHWEST WILL ACT TO DISLODGE VIGOROUS IMPULSE NOW MOVING TOWARD THE SRN PLAINS. THE NORTHWEST SHORT WAVE WILL RESULT IN A LARGE SCALE DEEP UPPER TROUGH BECOMING ESTABLISHED FROM THE FOUR CORNERS...ACROSS THE ROCKIES...TO THE NRN PLAINS DURING TUESDAY. THE SRN PLAINS IMPULSE WILL DEAMPLIFY AND ACCELERATE NEWD INTO MEAN RIDGE POSITION OVER THE ERN SEABOARD. SUBTROPICAL RIDGE WILL EXPAND OVER THE GULF OF MEX WITH BELT OF MODEST WSWLY MID LEVEL FLOW PERSISTING ON THE NRN PERIPHERY OF THE RIDGE...ACROSS THE GULF COAST REGION. IN THE WAKE OF THE EJECTING LEAD SHORT WAVE IMPULSE AFFECTING THE GULF COAST/LOWER MS VALLEY THROUGH DAY 1...MOIST ONSHORE FLOW AND WARM AIR ADVECTION WILL PERSIST FROM LA TO THE FL PNHDL. ...NRN GULF COAST... SCATTERED CONVECTION APPEARS POSSIBLE EARLY IN THE PERIOD IN BROAD ZONE OF WARM AIR AND MOISTURE ADVECTION OFF THE NRN GULF. LARGE SCALE FORCING FOR ASCENT AND DEEP SHEAR ARE FORECAST TO DIMINISH THROUGH THE PERIOD AS LEAD SHORT WAVE TROUGH AND ASSOCIATED STRONGER WIND FIELDS MOVE AWAY FROM THE REGION. HOWEVER...ADEQUATE SHEAR AND INSTABILITY MAY EXIST NEAR THE IMMEDIATE GULF COAST THROUGH TUESDAY AFTERNOON TO SUPPORT A LOW PROBABILITY CHANCE OF A SEVERE STORM OR TWO. ..CARBIN.. 10/16/2006  From swody2 at goshenarc.org Mon Oct 16 17:29:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 16 Oct 2006 13:29:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161731 SWODY2 SPC AC 161730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT MON OCT 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN MS...AL...FL PANHANDLE... ...SYNOPSIS... UPPER AIR PATTERN THROUGH PERIOD WILL CONTINUE TO FEATURE MEAN TROUGH OVER WRN CONUS...AND POSITIVELY TILTED RIDGE FROM CENTRAL GULF NEWD TOWARD QUE. MID/UPPER LEVEL LOW -- WITH MULTIPLE CIRCULATION CENTERS EVIDENT IN VIS IMAGERY ATTM -- WILL CONTINUE TO DIG SEWD ACROSS NWRN CONUS AND GREAT BASIN. BY 18/12Z...RESULT SHOULD BE HIGH-AMPLITUDE...POSITIVELY TILTED SYNOPTIC TROUGH FROM HUDSON BAY REGION TO VICINITY SRN CA AND NRN BAJA. FOREGOING PLUME OF SW FLOW ALOFT...FROM SRN CONUS AND NRN MEX TO OH/TN VALLEY REGIONS...MAY CONTAIN SEVERAL WEAK/EMBEDDED SHORTWAVES. MEANWHILE...TROUGH NOW LOCATED OVER ERN NM AND FAR W TX WILL DAMPEN CONSIDERABLY AND ACCELERATE NEWD FROM 17/12Z POSITION OVER SE TX...MID-SOUTH AND LOWER OH VALLEY REGIONS. AT SFC...MARINE/WARM FRONT NOW ANALYZED OVER SE TX AND S-CENTRAL LA IS FCST TO LIFT SLOWLY NEWD ACROSS MS/SWRN AL INTO EARLY DAY-2. THIS FRONT MAY BECOME DIFFUSE OVER AL/GA FROM AFTERNOON ONWARD...AS BOUNDARY LAYER FLOW WEAKENS/VEERS IN RESPONSE TO WEAKENING/EJECTION OF MIDLEVEL WAVE AWAY FROM AREA. MEANWHILE...FRONTOGENESIS AND CYCLOGENESIS ARE FCST OVER CENTRAL PLAINS AHEAD OF WRN CONUS SYNOPTIC TROUGH. BY 18/00Z...EXPECT SFC LOW INVOF SERN CO/OK PANHANDLE/SWRN KS REGION...SHIFTING SEWD ACROSS OK BY 18/12Z ALONG ASSOCIATED COLD FRONT. ...CENTRAL/ERN GULF COASTAL PLAIN...EARLY PERIOD... SCATTERED TSTMS -- WITH POTENTIAL FOR SUPERCELLS...TORNADOES AND ISOLATED DAMAGING GUSTS -- ARE POSSIBLE MAINLY OVER CATEGORICAL SLGT RISK AREA DURING FIRST HALF OF PERIOD. VERY FAVORABLE LOW LEVEL SHEAR PROFILES -- NOW PRESENT ACROSS LA -- ARE EXPECTED TO SHIFT EWD GRADUALLY THROUGH REMAINDER DAY-1 PERIOD INTO EARLY-DAY2...WITH 0-1 KM SRH COMMONLY ABOVE 200 J/KG. LARGE LOW LEVEL HODOGRAPHS...VERY RICH LOW LEVEL MOISTURE...AND WEAK CINH WILL SUPPORT POTENTIAL FOR TSTMS TO DEVELOP IN WARM SECTOR AND ROTATE...MARINE FRONT REPRESENTING NRN BOUND OF MOST PROBABLE SVR THREAT. BOUNDARY LAYER WIND AND SHEAR PROFILES ARE EXPECTED TO WEAKEN WITH TIME AND FROM W-E...DURING LATTER HALF OF PERIOD...AS WEAKENING UPPER TROUGH EJECTS WELL N-NE OF AREA. ...LA...SE TX...LATE PERIOD... ALTHOUGH NOT AS STRONG AS WITH DAY-1 THREAT...VERTICAL SHEAR PROFILES MAY INCREASE ENOUGH TO SUPPORT CONDITIONAL SUPERCELL/TORNADO POTENTIAL NOCTURNALLY ACROSS THIS REGION. LOW LEVEL FLOW IS FCST TO BACK TO SLY AFTER DARK...BENEATH ABOUT 30 KT 500 MB WINDS. FCST SOUNDINGS YIELD 0-1 KM SRH 100-150 J/KG BUT ONLY 30-35 KT EFFECTIVE BULK SHEAR. AIR MASS WILL REMAIN FAVORABLY MOIST WITH SFC DEW POINTS 70S F...NEARLY MOIST-ADIABATIC DEEP-LAYER LAPSE RATES...WEAK BUT SUFFICIENT BUOYANCY TO SUPPORT DEEP CONVECTION...AND EFFECTIVE PARCELS ROOTED AT SFC. EXPECT WEAK LOW LEVEL FORCING IN ABSENCE OF SIGNIFICANT BOUNDARIES. ..EDWARDS.. 10/16/2006  From swody2 at goshenarc.org Fri Oct 20 17:23:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 20 Oct 2006 13:23:40 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201725 SWODY2 SPC AC 201724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT FRI OCT 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...GULF COASTAL REGION... POTENT UPPER DISTURBANCE DIGGING THROUGH THE NRN ROCKIES TODAY WILL TRANSLATE TO THE SRN PLAINS EARLY SATURDAY BENEATH A BROAD TROUGH CENTERED OVER NRN ONTARIO. ASOCD COLD FRONT WILL MOVE SEWD AND REACH THE MIDWEST...THE DEEP S AND SRN TX BY 12Z SUNDAY. AHEAD OF THE FRONT...RESIDUAL FRONT ALONG THE GULF COAST WILL RETURN NWD INTO NRN AL AND GA WHILE THE MARINE FRONT REDEVELOPS TO ALONG THE IMMEDIATE GULF COAST THROUGH THE DAY SATURDAY. AS THE NEXT IMPULSE DROPS SEWD...RETURN FLOW WILL DEVELOP FROM S TX INTO THE SRN STATES LATE TONIGHT AND SATURDAY. BUT...LOW-LEVEL TRAJECTORIES WILL REMAIN WSWLY AND NOT FAVORABLE FOR THE MARITIME TROPICAL MOISTURE TO SURGE NWD. RATHER...LOW-LEVEL MOISTURE WILL GRADUALLY INCREASE WITH THE STRONGEST INSTABILITY REMAINING ALONG THE IMMEDIATE GULF COAST INVOF THE MARINE FRONT. WEAK WARM/MOIST ADVECTION WILL RESULT IN BANDS OF CONVECTION/TSTMS OVER THE WRN GULF BASIN/COASTAL TX EARLY IN THE PERIOD. THIS ACTIVITY WILL THEN DEVELOP ENEWD AHEAD OF THE APPROACHING COLD FRONT DURING SATURDAY AFTN. ADDITIONAL TSTMS WILL DEVELOP ALONG THE PRIMARY COLD FRONT ACROSS SERN/S TX SATURDAY EVE/OVERNIGHT. FORECAST SOUNDINGS ALONG THE GULF COAST SUGGEST THAT LOW-LEVEL SHEAR WILL BE SOMEWHAT LACKING...THOUGH DEEP LAYER SHEAR COULD SUPPORT ORGANIZED UPDRAFTS. GIVEN THE EXPECTED WEAK LOW-LEVEL SHEAR AND WEAK INSTABILITY/LAPSE RATES...IT APPEARS MOST TSTMS WILL REMAIN BELOW SEVERE LEVELS...THOUGH ISOLD DAMAGING WINDS/TORNADOES MAY OCCUR ALONG THE GULF COAST. DEEPENING WLY FLOW SHOULD ALLOW CONVECTION TO SPREAD INTO THE SERN STATES LATE SATURDAY NIGHT. ..RACY.. 10/20/2006  From swody2 at goshenarc.org Sat Oct 21 04:30:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 21 Oct 2006 00:30:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210431 SWODY2 SPC AC 210430 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 PM CDT FRI OCT 20 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... STRONG SFC FRONT WILL MOVE ACROSS THE CNTRL GULF STATES INTO CNTRL FL PENINSULA BY THE END OF THE PERIOD AS UPSTREAM RIDGE BUILDS INTO THE SRN PLAINS. DEEP LAYER FLOW WILL VEER AHEAD OF FRONTAL PASSAGE ACROSS THE SERN U.S. AND MID LEVEL LAPSE RATES WILL REMAIN QUITE WEAK...ON THE ORDER OF 5-5.5 C/KM...WITHIN THE WARM SECTOR. ANY THUNDERSTORMS THAT DEVELOP IN ASSOCIATION WITH FRONTAL PASSAGE SHOULD DO SO WITHIN A THERMODYNAMIC ENVIRONMENT NOT PARTICULARLY CONDUCIVE FOR STRONG/ROBUST UPDRAFTS. IN ADDITION...MEAN FLOW SHOULD BE ROUGHLY 25KT SUGGESTING ANY STORMS THAT DEVELOP WILL MAINTAIN MULTI-CELL CHARACTERISTICS. FURTHERMORE...MAJORITY OF DEEP CONVECTION WILL LIKELY CONCENTRATE OFFSHORE OVER WARMER WATERS OF THE GULF OF MEXICO...AND OVER THE GULF STREAM OFF THE FL/CAROLINA COAST LATE IN THE PERIOD. ..DARROW.. 10/21/2006  From swody2 at goshenarc.org Sat Oct 21 16:50:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 21 Oct 2006 12:50:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211651 SWODY2 SPC AC 211650 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1150 AM CDT SAT OCT 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF STATES AND THE SERN ATLANTIC SEABOARD... VIGOROUS SHORTWAVE TROUGH ACROSS THE PLAINS TODAY WILL ROTATE EWD ACROSS THE OH VLY AND MID-ATLANTIC STATES TONIGHT AND SUNDAY. ASSOCD COLD FRONT WILL SURGE SEWD IN WAKE OF THE DISTURBANCE... REACHING THE ATLANTIC SEABOARD...NRN FL AND THE NRN GULF BASIN OVERNIGHT SUNDAY. PRIMARY FORCING FOR ASCENT WILL PASS ACROSS THE GRTLKS AND OH VLYS ON SUNDAY WITH THE DEEP LAYER FLOW ALONG THE GULF COAST AND SERN STATES LIKELY TO VEER WLY AHEAD OF THE COLD FRONT. THIS WILL NOT BE FAVORABLE FOR THE MARITIME TROPICAL AIR MASS TO SURGE NWD INTO THE REGION. LAPSE RATES ALOFT WILL ALSO BE QUITE POOR AND SFC-BASED INSTABILITY EQUALLY UNIMPRESSIVE FOR STRONG UPDRAFTS. FURTHERMORE...VERTICAL SHEAR WILL GENERALLY BE AOB 30 KTS SUGGESTING THAT TSTMS THAT DO DEVELOP WILL BE MAINTAINED IN THE MULTICELL SPECTRUM. STRONGER STORMS WILL DEVELOP OFFSHORE IN THE MORE UNSTABLE MARINE ENVIRONMENT...NAMELY OVER THE NERN GULF OF MEXICO SUNDAY AFTN AND OVER THE GULF STREAM WATERS SUNDAY NIGHT/EARLY MON. ..RACY.. 10/21/2006  From swody2 at goshenarc.org Sun Oct 22 05:29:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 22 Oct 2006 01:29:27 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220530 SWODY2 SPC AC 220530 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CDT SUN OCT 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTH FL... WEAK WARM ADVECTION NEAR FRONTAL ZONE MAY PROVIDE SUFFICIENT ASCENT FOR A FEW THUNDERSTORMS EARLY IN THE PERIOD ACROSS SOUTH FL. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUFFICIENT INSTABILITY WILL EXIST THE FIRST 3-6 HOURS FOR ISOLATED THUNDERSTORMS...HOWEVER RAPIDLY WEAKENING LAPSE RATES AND COLD ADVECTION WILL NEGATE CONVECTIVE THREAT BY 18Z. ...SWRN U.S... MID LEVEL MOISTENING WILL SPREAD NWD ACROSS NWRN MEXICO TOWARD SRN AZ DURING THE LATE AFTERNOON HOURS MONDAY. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...IT APPEARS SUFFICIENT INSTABILITY WILL DEVELOP WITHIN WARM CONVEYOR FOR A FEW THUNDERSTORMS AHEAD OF UPPER TROUGH. HOWEVER...MORE MEANINGFUL DEEP CONVECTION WILL REMAIN SUPPRESSED SOUTH OF THE BORDER. ..DARROW.. 10/22/2006  From swody2 at goshenarc.org Sun Oct 22 16:04:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 22 Oct 2006 12:04:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221605 SWODY2 SPC AC 221604 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1104 AM CDT SUN OCT 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...S FL... COLD FRONT WILL MOVE SWD ACROSS S FL ON MON AFTN...PRECEDED BY A PRE-FRONTAL TROUGH. WARM SECTOR AIR MASS WILL BE SUFFICIENTLY UNSTABLE TO SUPPORT ISOLD TSTMS...PRIMARILY DURING THE EARLY PART OF THE DAY. NO SVR WEATHER IS ANTICIPATED. ...INTERNATIONAL BORDER AZ/NM... DEVELOPING WARM CONVEYOR AHEAD OF THE UPR LOW SEVERAL HUNDRED MILES W OF BAJA CA WILL CONTRIBUTE TO GRADUAL MOISTENING OF THE MID-UPR TROPOSPHERE MON NIGHT ACROSS NRN MEXICO AND THE BORDER REGIONS OF AZ/NM. THERMODYNAMIC PROFILES BECOME SUFFICIENTLY UNSTABLE BY DAYBREAK TUE TO SUPPORT ISOLD GENERAL TSTMS AS FAR N AS EXTREME SRN AZ/NM. MOST TSTMS WILL BE ACROSS NWRN MEXICO. ..RACY.. 10/22/2006  From swody2 at goshenarc.org Mon Oct 23 05:25:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 23 Oct 2006 01:25:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230526 SWODY2 SPC AC 230525 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1225 AM CDT MON OCT 23 2006 VALID 241200Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SWRN U.S...SRN PLAINS... UPPER RIDGING WILL GRADUALLY BREAK DOWN OVER THE SRN PLAINS TUE AS SEVERAL WEAK SHORTWAVE TROUGHS EJECT NEWD ACROSS NRN MEXICO INTO THE SRN ROCKIES/TX REGION. THESE FEATURES WILL ENHANCE WARM ADVECTION PROFILES DOWNSTREAM...WHILE ALLOWING MID LEVEL MOISTENING/WEAK ELEVATED DESTABILIZATION WITHIN A PLUME THAT SHOULD STRETCH NEWD ACROSS WEST TX INTO OK. LATEST GUIDANCE SUGGESTS BOUNDARY LAYER MODIFICATION ACROSS THE WRN GULF OF MEXICO WILL BE IMPEDED BY SFC RIDGING...THUS FORECAST PROFILES ARE NOT PARTICULARLY UNSTABLE INLAND. EVEN SO...ISOLATED THUNDERSTORMS MAY EVOLVE WITHIN ELEVATED CONVECTION ACROSS OUTLOOK AREA. UPSTREAM...BOUNDARY LAYER DESTABILIZATION SHOULD BE MAXIMIZED NEAR THE LOWER CO RIVER VALLEY BENEATH COOLING MID LEVEL TEMPERATURES OF TROUGH AXIS. ISOLATED THUNDERSTORMS SHOULD EVOLVE ACROSS SERN CA INTO PORTIONS OF AZ DURING THE AFTERNOON HOURS. ...PACIFIC NW... STRONG SHORTWAVE TROUGH WILL DIG SEWD INTO THE PACIFIC NW EARLY IN THE PERIOD...WITH FOCUSED ASCENT EXPECTED WITHIN EXIT REGION OF JET AXIS. ISOLATED THUNDERSTORMS COULD EVOLVE WITHIN THIS ZONE FROM SERN B.C. INTO THE ID PANHANDLE...AND PERHAPS WRN MT. ADDITIONALLY...STRONG COLD ADVECTION IN THE WAKE OF FRONTAL PASSAGE SHOULD ENHANCE MARITIME BOUNDARY LAYER INSTABILITY ACROSS NWRN WA. A FEW THUNDERSTORMS SHOULD DEVELOP ACROSS THIS REGION THROUGH 00Z/25TH...THEN WARM ADVECTION WILL WEAKEN LAPSE RATES AND CONVECTION SHOULD WANE. ..DARROW.. 10/23/2006  From swody2 at goshenarc.org Wed Oct 25 05:18:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 25 Oct 2006 01:18:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250521 SWODY2 SPC AC 250520 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 AM CDT WED OCT 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN PORTIONS OF THE SRN PLAINS/EAST TX INTO THE CNTRL GULF COAST STATES... LATEST NAM/GFS MODEL GUIDANCE IS NOTICEABLY SLOWER IN EJECTING UPPER LOW EWD ACROSS OK DURING THE DAY2 PERIOD. THIS SLOWER EVOLUTION WILL SIMPLY ALLOW NARROW MOIST AXIS TO ESTABLISH ITSELF A BIT FARTHER WEST ACROSS ERN OK INTO NERN TX PRIOR TO AFTERNOON CONVECTIVE DEVELOPMENT. LATEST THINKING IS STRONG DYNAMIC SYSTEM WILL FORCE LEE CYCLONE SEWD INTO NCNTRL OK BY LATE AFTERNOON...BEFORE WARM ADVECTION DRIVES SFC LOW EWD TOWARD THE BOOT HEEL OF MO BY THE END OF THE PERIOD. THE POTENTIAL FOR SEVERE THUNDERSTORM DEVELOPMENT WILL FOCUS MAINLY ACROSS ERN OK INTO AR WHERE GREATEST FORCING WILL COINCIDE WITH STEEPER LAPSE RATE PLUME THAT SHOULD OVERSPREAD THE FRONTAL BOUNDARY...ENHANCING SBCAPE TO VALUES APPROACHING 1000 J/KG. STRONGLY FORCED BAND OF THUNDERSTORMS SHOULD DEVELOP ALONG COLD FRONT BY 21Z ACROSS ERN OK INTO NERN TX. SEVERE SQUALL LINE WITH DAMAGING WINDS AND LARGE HAIL APPEAR TO BE THE GREATEST THREATS. HOWEVER...SUPERCELL STRUCTURES ARE CERTAINLY POSSIBLE GIVEN THE FORECAST SHEAR PROFILES...ESPECIALLY EARLY IN THE CONVECTIVE CYCLE. IF BOUNDARY LAYER DEW POINTS CAN INDEED RISE INTO THE UPPER 60S AS SUGGESTED BY LATEST GUIDANCE...ISOLATED TORNADOES CAN NOT BE RULED OUT. OTHERWISE...SUSTAINED PLUME OF WARM ADVECTION-INDUCED THUNDERSTORMS WILL STRETCH SW-NE ACROSS THE COASTAL PLAINS OF TX INTO LA...MAINTAINING A WEAK-NEUTRAL LAPSE RATE PROFILE AND SUPPRESSING DIABATIC HEATING. EVEN SO...STRONG STORMS WILL LIKELY DEVELOP ALONG THE ENTIRE FRONTAL BOUNDARY AS IT SURGES EWD ACROSS THE LOWER MS VALLEY REGION DURING THE OVERNIGHT HOURS. DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT AS SQUALL LINE MATURES AND RACES EWD...EVENTUALLY WEAKENING DOWNSTREAM LATE IN THE PERIOD WHERE INSTABILITY WILL BE NOTABLY WEAKER. ..DARROW.. 10/25/2006  From swody2 at goshenarc.org Thu Oct 26 05:36:15 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 26 Oct 2006 01:36:15 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260539 SWODY2 SPC AC 260538 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CDT THU OCT 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE GULF COAST REGION... STRONG DYNAMIC UPPER LOW WILL EJECT ACROSS OK/TX DURING THE DAY1 PERIOD INTO THE LOWER MS VALLEY BY 27/12Z...WITH A SHARP FRONTAL ZONE EXTENDING SWD FROM A SFC LOW OVER AR INTO LA. THIS BOUNDARY WILL LIKELY REMAIN QUITE ACTIVE WITH THUNDERSTORMS THROUGH THE LATE DAY1 PERIOD INTO DAY2 WITH A WELL FORCED SQUALL LINE EXPECTED TO BE ONGOING AT THE BEGINNING OF THE PERIOD. SFC RIDGING OVER THE CNTRL/ERN GULF COAST WILL INITIALLY PROVE QUITE HOSTILE IN BOUNDARY LAYER RECOVERY AHEAD OF THIS SYSTEM. ADDITIONALLY...CONSIDERABLE AMOUNT OF RAIN WILL SLOW RECOVERY PROCESS INLAND FROM CNTRL MS INTO CNTRL GA. INITIALLY IT APPEARS GREATEST BOUNDARY LAYER MOISTENING WILL OCCUR ACROSS THE UPPER TX COAST/SWRN LA WHERE SFC DEW POINTS ARE RISING THROUGH THE 60S TO NEAR 70F. MUCH OF SRN LA INTO THE FL PANHANDLE SHOULD EASILY DESTABILIZE AS LLJ VEERS AND SFC WARM FRONT LIFTS NWD INTO PORTIONS OF CNTRL AL/WCNTRL GA BY 18Z. AT THIS TIME INSTABILITY SUFFICIENT FOR SEVERE SUPERCELLS MAY BE LIMITED TO THE SRN GULF STATES. NAM IS MORE AGGRESSIVE IN BOUNDARY LAYER RECOVERY THAN THE GFS WHICH AT TIMES IS SLOW TO BRING MOISTURE INLAND. EVEN SO...STRENGTH OF UPPER SYSTEM SUGGESTS AN ORGANIZED SQUALL LINE WILL PROGRESS EWD ACROSS THE GULF STATES...WHILE THE POSSIBILITY EXISTS FOR DISCRETE SUPERCELL STRUCTURES AND ISOLATED TORNADOES...AHEAD OF MAIN LINE WHERE SUFFICIENT BOUNDARY LAYER INSTABILITY CAN DEVELOP. ...CAROLINAS... LATER IN THE PERIOD...WELL DOWNSTREAM...NAM AGGRESSIVELY FORCES HIGHER MOISTURE JUST INLAND ALONG THE CAROLINA COAST. THIS SCENARIO SEEMS PLAUSIBLE GIVEN THE EXPECTED INCREASE IN LLJ AFTER 00Z ACROSS THIS REGION. IF HIGHER THETA-E AIRMASS DOES INDEED SPREAD INTO THE COASTAL CAROLINAS THE POTENTIAL FOR TORNADOES WILL CERTAINLY INCREASE. HOWEVER...THERE REMAINS ENOUGH UNCERTAINTY IN BOUNDARY LAYER RECOVERY INLAND TO MAINTAIN LOW PROBABILITIES FOR SEVERE AT THIS TIME. WILL CONTINUE TO MONITOR THIS REGION FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ..DARROW.. 10/26/2006  From swody2 at goshenarc.org Fri Oct 27 05:42:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 27 Oct 2006 01:42:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270545 SWODY2 SPC AC 270544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT FRI OCT 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFICATION IN THE NORTHERN BRANCH OF THE POLAR WESTERLIES APPEARS UNDERWAY...MUCH AS SUGGESTED BY THE MODELS...WITH A STRONG MID/UPPER JET STREAK NOSING AROUND A BUILDING UPPER RIDGE ACROSS THE EAST CENTRAL PACIFIC INTO THE CANADIAN/NORTHERN U.S. ROCKIES. EXIT REGION OF THIS JET STREAK...AND AN ASSOCIATED SHORT WAVE TROUGH...ARE PROGGED INTO THE UPPER GREAT LAKES REGION BY 12Z SATURDAY...BEFORE CONTINUING TO DIG SOUTHEASTWARD AND MERGING WITH A SOUTHERN BRANCH IMPULSE LIFTING OUT OF THE CENTRAL GULF STATES AND TENNESSEE VALLEY. CONSOLIDATING IMPULSES WILL LIKELY EVOLVE INTO A DEEPENING LOW/MID-LEVEL CYCLONE OVER THE LOWER GREAT LAKES/ ST. LAWRENCE VALLEY REGION LATE SATURDAY INTO EARLY SUNDAY. ...ATLANTIC SEABOARD... VARIABILITY EXISTS AMONG THE MODELS CONCERNING THE DETAILS OF SURFACE LOW DEVELOPMENT ACROSS THE NORTHERN MID ATLANTIC COAST STATES EARLY IN THE FORECAST PERIOD...ASSOCIATED WITH THE SOUTHERN STREAM IMPULSE. IN ALL LIKELIHOOD THOUGH...STRONG WIND FIELDS/SHEAR PROFILES SUPPORTIVE OF A DAMAGING WIND/TORNADO THREAT WILL EXIST IN A MOIST PRE-FRONTAL ENVIRONMENT FROM EASTERN NORTH CAROLINA INTO THE CENTRAL/SOUTHERN FLORIDA PENINSULA AT 12Z SATURDAY. HOWEVER...MODELS CONTINUE TO INDICATE THAT THERMODYNAMIC PROFILES IN THIS REGIME WILL BE NEARLY SATURATED...WITH LAPSE RATES TRENDING TOWARD MOIST ADIABATIC AND SUPPORTIVE OF ONLY VERY WEAK CAPE. THUS...ALTHOUGH A BROKEN SQUALL LINE MAY BE ONGOING ALONG/JUST AHEAD OF SURFACE FRONT...POTENTIAL FOR INTENSIFICATION SEEMS LIMITED BEFORE ACTIVITY PROGRESSES OFFSHORE. THE WINDOW OF OPPORTUNITY MAY BE SMALL AS WELL...AS LOW-LEVEL FLOW FIELDS ACROSS THE MIDDLE AND SOUTHERN ATLANTIC SEABOARD ARE PROGGED TO VEER TO WESTERLY BY MID DAY SATURDAY...IN THE WAKE OF THE SOUTHERN STREAM SHORT WAVE TROUGH AXIS. ASSOCIATED COOLING AND DRYING OF LOWER LEVELS WILL END CONVECTIVE THREAT. ..KERR.. 10/27/2006  From swody2 at goshenarc.org Sun Oct 29 17:11:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 29 Oct 2006 12:11:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291714 SWODY2 SPC AC 291713 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CST SUN OCT 29 2006 VALID 301200Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PHASED NRN AND SRN STREAM TROUGHS WILL MOVE EWD ACROSS THE PLAINS THIS PERIOD. AS THIS OCCURS...A SURFACE COLD FRONT WILL SURGE SEWD ACROSS THE PLAINS...AND SHOULD EXTEND FROM THE UPPER GREAT LAKES REGION SSWWD INTO THE MID MS/LOWER OH VALLEY...AND THEN SWWD ACROSS THE ARKLATEX INTO TX. CAPPING COMBINED WITH A GENERAL LACK OF LOW-LEVEL MOISTURE/INSTABILITY SHOULD LIMIT CONVECTIVE POTENTIAL ALONG MOST OF FRONTAL ZONE THROUGH THE END OF THE PERIOD. ...SERN KS/ERN OK/MO/SRN IL/AR... GREATEST CONVECTIVE THREAT APPEARS TO EXIST ACROSS PARTS OF MO DURING THE LATTER HALF OF THIS PERIOD...AS LIMITED BOUNDARY LAYER MOISTURE RETURNS NWD FROM THE GULF INTO MO/ERN OK/AR AHEAD OF FRONT. THOUGH LOW-LEVEL CAPPING AND MINIMAL INSTABILITY SHOULD LIMIT POTENTIAL COVERAGE AND INTENSITY OF CONVECTION...DEGREE OF QG FORCING SUGGESTS THAT SCATTERED/WEAK STORM DEVELOPMENT MAY OCCUR INVOF FRONT AFTER SUNSET. WITH INSTABILITY FORECAST TO BE MINIMAL...WILL NOT INTRODUCE ANY SEVERE PROBABILITIES ATTM. ..GOSS.. 10/29/2006  From swody2 at goshenarc.org Mon Oct 30 06:28:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 30 Oct 2006 01:28:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300631 SWODY2 SPC AC 300630 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CST MON OCT 30 2006 VALID 311200Z - 011200Z ...NO SVR TSTM AREAS FORECAST... A VIGOROUS SHORT WAVE TROUGH IN THE NORTHERN BRANCH OF THE POLAR WESTERLIES AND WEAK BROAD TROUGHING IN THE SOUTHERN STREAM ARE NOW CONTRIBUTING TO THE EVOLUTION OF A LARGE SCALE TROUGH FROM THE INTERMOUNTAIN WEST INTO THE PLAINS...MUCH AS PROGGED BY THE MODELS THE PAST FEW DAYS. AND...MODELS CONTINUE TO INDICATE THAT CYCLONIC UPPER FLOW WILL DEVELOP EASTWARD THROUGH THE ATLANTIC SEABOARD LATER TODAY THROUGH TUESDAY/TUESDAY NIGHT. THIS IS FORECAST TO OCCUR AS THE NORTHERN IMPULSE PIVOTS AROUND THE SOUTHERN/EASTERN PERIPHERY OF A BROAD CIRCULATION NOW FORMING OVER THE CANADIAN PRAIRIES...AND INCREASINGLY SHEARED SOUTHERN IMPULSE ACCELERATES ACROSS THE OZARK PLATEAU/MIDDLE MISSISSIPPI VALLEY THROUGH THE MID ATLANTIC REGION BY 12Z WEDNESDAY. ANOTHER IMPULSE IN THE SOUTHERN STREAM IS PROGGED TO SHIFT ACROSS SOUTHERN CALIFORNIA/NORTHERN BAJA INTO THE FOUR CORNERS STATES AND NORTHERN MEXICAN PLATEAU TUESDAY. IN RESPONSE TO THIS FEATURE... COLD FRONT ASSOCIATED WITH INITIAL NORTHERN BRANCH SHORT WAVE WILL PROBABLY SLOW OR STALL OVER PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST TEXAS. NORTHERN PORTION OF THE FRONT IS PROGGED TO SURGE EAST OF THE UPPER MISSISSIPPI VALLEY INTO THE NORTH ATLANTIC COAST...TO THE SOUTH/EAST OF ASSOCIATED DEEP OCCLUDING SURFACE LOW OVER ONTARIO. ...LOWER MISSISSIPPI VALLEY... AS BULK OF SOUTHERN STREAM TROUGH SHIFTS WELL TO THE EAST/NORTHEAST OF REGION EARLY IN THE PERIOD...LOW LEVEL FLOW FIELDS AHEAD OF SURFACE FRONT ARE FORECAST TO VEER AND WEAKEN. MID-LEVEL FLOW IS PROGGED TO WEAKEN AS WELL...BUT COULD REMAIN STRONG ENOUGH TO MAINTAIN AT LEAST MODERATE DEEP LAYER SHEAR INTO THE PEAK AFTERNOON HEATING HOURS TUESDAY. PRE-FRONTAL ENVIRONMENT DOES APPEAR LIKELY TO CONTINUE TO MOISTEN WITH ADVECTION OFF THE WESTERN GULF OF MEXICO. AND...MODELS SUGGEST A WEAK TO MODERATE CONDITIONALLY AND CONVECTIVELY UNSTABLE ENVIRONMENT WILL EVOLVE BY TUESDAY AFTERNOON FROM UPPER TEXAS COASTAL AREAS INTO NORTHERN MISSISSIPPI. THOUGH STRENGTH OF LARGE-SCALE FORCING IS UNCERTAIN...MODELS INDICATE WEAKENED INHIBITION ALONG A LINGERING MID-LEVEL SHEAR AXIS...WHICH MAY ALLOW THE INITIATION OF SCATTERED THUNDERSTORM ACTIVITY. IF THIS OCCURS...CAPE OF 1000-1500 J/KG COULD SUPPORT AN ISOLATED STRONG/SEVERE STORM OR TWO CAPABLE OF MARGINALLY SEVERE HAIL...POSSIBLY A DOWNBURST. ..KERR.. 10/30/2006  From swody2 at goshenarc.org Mon Oct 30 18:01:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 30 Oct 2006 13:01:24 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301804 SWODY2 SPC AC 301803 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 1203 PM CST MON OCT 30 2006 VALID 311200Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD BELT OF CYCLONIC MID-LEVEL FLOW /ANCHORED BY VORTEX OVER CNTRL CANADA/ WILL PERSIST THROUGH THE DAY TWO PERIOD OVER MUCH OF THE CONUS. WITHIN THIS REGIME...SRN STREAM SHORT WAVE TROUGH /NOW NEAR THE 4-CORNERS REGION/ IS FORECAST TO WEAKEN AS IT TRANSLATES FROM THE ARKLATEX/LOWER MS VALLEY EWD INTO THE TN VALLEY AND CNTRL GULF COAST STATES. IN THE LOW-LEVELS...SURFACE COLD FRONT INITIALLY FROM THE LOWER OH VALLEY SWWD INTO WRN TX WILL PUSH SEWD AND LIKELY EXTEND FROM WRN OR MIDDLE TN SWWD THROUGH THE ARKLATEX REGION BY LATE TUESDAY AFTERNOON. THIS BOUNDARY WILL BE THE PRIMARY FOCUS FOR TSTM DEVELOPMENT THROUGH THE PERIOD. ...OZARK PLATEAU SWD INTO THE LOWER MS VALLEY... AS MENTIONED IN CURRENT DAY ONE CONVECTIVE OUTLOOK...SOME POTENTIAL FOR ISOLATED SEVERE STORMS WILL EXIST AT THE ONSET OF THE PERIOD OVER THE OZARK PLATEAU WITHIN ZONE OF LOW-LEVEL WAA AHEAD OF SRN STREAM IMPULSE AND ASSOCIATED SURFACE COLD FRONT. THIS ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF DAY EWD INTO THE TN VALLEY...THOUGH STORMS SHOULD TEND TO DIMINISH IN INTENSITY AS FORCING FOR ASCENT DECREASES AND STORMS SHIFT AWAY FROM THE STRONGER INSTABILITY OVER THE LOWER MS VALLEY. POTENTIAL FOR ADDITIONAL SURFACE-BASED STORM DEVELOPMENT WILL INCREASE BY AFTERNOON ALONG OR AHEAD OF THE FRONT OVER LA WITHIN A MOIST LOW-LEVEL AIR MASS CHARACTERIZED BY DEWPOINTS IN THE 60S AND RESULTANT MLCAPES OF 1000-1500 J/KG. PRIMARY UNCERTAINTY IS DEGREE OF FORCING AS: 1) IT APPEARS THAT SHORT WAVE TROUGH MAY HAVE SHIFTED TO THE E PRIOR TO PEAK HEATING/TIME OF STRONGEST INSTABILITY...AND 2) APPARENT SHALLOW FRONTAL ZONE. SHOULD DEEP...MOIST CONVECTION INITIATE AND BECOME SUSTAINED...POTENTIAL WILL EXIST FOR A FEW SEVERE STORMS CAPABLE OF HAIL/LOCALLY DAMAGING WINDS GIVEN THE MODERATE INSTABILITY AND 35-40 KTS OF DEEP-LAYER SHEAR. ONLY LOW SEVERE PROBABILITIES WILL BE INCLUDED ATTM OWING TO UNCERTAINTY IN CONVECTIVE EVOLUTION. ..MEAD.. 10/30/2006  From swody2 at goshenarc.org Sun Oct 1 05:47:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 01 Oct 2006 01:47:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 010546 SWODY2 SPC AC 010545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT SUN OCT 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY INTO THE CNTRL GRTLKS... ...UPR MS VLY TO CNTRL GRTLKS... MAIN BELT OF WLYS WILL BE CONFINED TO SRN CANADA WHERE A MID-LEVEL WAVE WILL TRANSLATE THROUGH THE CANADIAN PRAIRIES. TO THE S...A SUB-TROPICAL JET AND EMBEDDED DISTURBANCES WILL EXIST FROM SRN CA NEWD INTO THE PLAINS. MODELS DISAGREE ON THE AMPLITUDE OF THESE SUB-TROPICAL WAVES. AT THE SFC...A LEE LOW WILL DEVELOP NEWD ACROSS SD ALONG A SWD MOVING COLD FRONT. TO THE S...A LEE TROUGH WILL MOVE EWD INTO NEB AND WRN KS. A MODEST SWLY LLJ WILL BE PRESENT DURING THE NEXT COUPLE OF DAYS...AIMED FROM THE ERN PLAINS TO THE UPPER MS VLY. THIS WILL TRANSPORT MODIFIED GULF MOISTURE NWD BENEATH STEEPENING MID- TROPOSPHERIC LAPSE RATES /EML/. THE STRENGTH OF THE EML WILL MOST LIKELY PRECLUDE SFC-BASED TSTMS ALONG THE LEE-TROUGH AND COLD FRONT OVER THE PLAINS. PARCELS WILL LIKELY CONVECT DOWNSTREAM FROM THE STRONGER CAP ACROSS PARTS OF THE UPPER MS VLY INTO THE CNTRL GRTLKS LATE SUNDAY/EARLY MON. THIS ACTIVITY WILL WEAKEN AS IT TRANSLATE ESEWD DURING MONDAY AFTN. STRONGER INSTABILITY WILL DEVELOP UPSTREAM ACROSS THE CORN BELT/ERN PLAINS MON AFTN. THERMAL RIDGE/CAP MAY DEVELOP NEWD AS FAR AS THE UPPER MS VLY COINCIDENT WITH MODEST BOUNDARY LAYER MSTR. IF LARGE SCALE SUPPORT...TIED TO THE SUB-TROPICAL IMPULSES...IS AS STRONG AS THE NAM...SFC-BASED CONVECTION MAY DEVELOP ALONG THE NOSE OF THE THERMAL RIDGE. OTHERWISE...ELEVATED CONVECTION MAY WAIT UNTIL AFTER DARK TO DEVELOP ALONG THE AXIS OF THE LLJ. IF SFC BASED TSTMS CAN MANAGE TO FORM...POTENTIAL FOR SUPERCELLS WITH LARGE HAIL...DAMAGING WINDS AND TORNADOES WILL EXIT. OTHERWISE...ELEVATED TSTMS WILL PRODUCE LARGE HAIL. GIVEN THE UNCERTAINTY ON OVERALL CONVECTIVE EVOLUTION...FRONTAL PLACEMENTS...MAGNITUDE OF THERMODYNAMICS AND WHETHER UPPER SUPPORT WILL BE SUFFICIENT...HAVE INTRODUCED A LOW-END SLGT CATEGORICAL RISK. ..RACY.. 10/01/2006  From swody2 at goshenarc.org Sun Oct 1 16:50:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 01 Oct 2006 12:50:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 011650 SWODY2 SPC AC 011649 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1149 AM CDT SUN OCT 01 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER MIDWEST... ...SYNOPSIS... PROGRESSIVE LARGE-SCALE PATTERN IS FORECAST DURING THE DAY TWO PERIOD WITH SEVERAL WEAK PERTURBATIONS EMBEDDED IN BROAD WSWLY FLOW REGIME FROM THE GREAT BASIN INTO THE UPPER MIDWEST. IN THE LOW-LEVELS...SURFACE FRONT WILL SLOWLY SAG SWD THROUGH THE UPPER GREAT LAKES WITH WRN EXTENSION OF THIS BOUNDARY REMAINING QUASI-STATIONARY OR PERHAPS RETREATING NWD SLIGHTLY AS LOW PRESSURE INTENSIFIES OVER NEB. ...UPPER MIDWEST... CLUSTERS OF ELEVATED TSTMS...FOCUSED WITH ZONE OF ENHANCED MOIST/THERMAL ADVECTION ALONG NOSE OF 40-45 KT WSWLY LLJ...WILL LIKELY DEVELOP EWD ACROSS LOWER MI MONDAY MORNING. WHILE VERTICAL SHEAR THROUGH THE CLOUD-BEARING LAYER WILL NOT BE PARTICULARLY STRONG...THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES AND RESULTANT MUCAPES OF 1000-1500 J/KG MAY SUPPORT SOME MARGINALLY SEVERE HAIL WITH THE MOST INTENSE STORMS. OTHER DIURNAL...SURFACE-BASED STORMS WILL BE POSSIBLE MONDAY AFTERNOON INTO EVENING ALONG SURFACE FRONT SLOWLY PUSHING SWD THROUGH WI. PRESENCE AND/OR TIMING OF ANY SIGNIFICANT SHORT WAVE TROUGHS TO FOCUS THIS CONVECTION REMAINS IN QUESTION ATTM...LEADING TO UNCERTAINTY IN CONVECTIVE EVOLUTION AND INHERENT SEVERE WEATHER THREAT. NONETHELESS...INCREASING BOUNDARY LAYER MOISTURE BENEATH PLUME OF STEEP MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO MODERATE AFTERNOON INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. CAPPING WILL BE AN ISSUE...BUT LATEST MODEL GUIDANCE DOES SUGGEST THAT THE INITIATION OF DEEP...MOIST CONVECTION WILL OCCUR BY MID TO LATE AFTERNOON OVER CNTRL OR SRN WI. VERTICAL SHEAR WILL BE MODEST /I.E. EFFECTIVE BULK SHEARS AOB 30-35 KT/ THOUGH THE DEGREE OF INSTABILITY WILL SUPPORT A FEW SEVERE STORMS CAPABLE OF LARGE HAIL AND LOCALLY DAMAGING WINDS. ADDITIONAL MORE ELEVATED STORMS WILL BE POSSIBLE MONDAY NIGHT WWD INTO SRN MN/NRN IA AS INCREASING NOCTURNAL LLJ ENHANCES CONVERGENCE ALONG SURFACE BOUNDARY. EXISTING CAP WILL REMAIN PROBLEMATIC...THOUGH ISOLATED STORMS APPEAR POSSIBLE WITH A THREAT OF MARGINALLY SEVERE HAIL AND/OR LOCALLY STRONG WIND GUSTS. ..MEAD.. 10/01/2006  From swody2 at goshenarc.org Mon Oct 2 06:09:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 02 Oct 2006 02:09:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 020556 SWODY2 SPC AC 020555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT MON OCT 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS VLY AND CNTRL GRTLKS REGION... ...UPPER MS VLY EWD INTO THE CNTRL GRTLKS... TWO-STREAM FLOW REGIME WILL CONTINUE INTO TUE WITH A SRN STREAM TROUGH EVOLVING ACROSS THE PAC COAST AND A BROAD RIDGE ACROSS THE SRN STATES. WITHIN THE NRN STREAM...A MID-LEVEL WAVE WILL SKIRT ACROSS THE NRN GRTLKS REGION ON TUE WHILE A SUB-TROPICAL IMPULSE...EJECTING AHEAD OF THE WRN COAST TROUGH...MOVES ACROSS THE PLAINS TO THE UPPER MS VLY. THE FRONT ASSOCD WITH THE CANADIAN DISTURBANCE WILL MOVE SWD AND STALL FROM MI TO NEB BY 12Z TUE AS A LOW DEVELOPS OVER IA. THE LOW WILL MOVE NEWD ALONG THE FRONT INTO SERN ONTARIO BY EARLY WED. TRAILING THE LOW...THE FRONT WILL RESUME A SEWD MOVEMENT... REACHING THE MIDWEST...OZARKS AND THE SRN PLAINS BY 12Z WED. A STRONG ELEVATED MIXED LAYER /EML/ HAS SPREAD EWD ACROSS THE PLAINS WITH H7-H5 LAPSE RATES IN EXCESS OF 8 DEG C/KM. THIS STRONG EML WILL CONTINUE TO ADVECT EWD ALONG/S OF THE APPROACHING COLD FRONT THROUGH TUE. AT THE SAME TIME...BOUNDARY LAYER MSTR WILL GRADUALLY INCREASE ACROSS THE PLAINS INTO THE UPPER MS VLY WITH SFC DEW POINTS LIKELY IN THE LWR 60S BY TUE AFTN. MORNING ELEVATED CONVECTION SHOULD WEAKEN AND MOVE EWD OUT OF THE REGION EARLY ON TUE. BUT...AS WEAK LARGE SCALE ASCENT TIED TO THE SUB-TROPICAL DISTURBANCE SPREADS EWD...TSTMS ARE EXPECTED TO DEVELOP OVER PARTS OF THE UPPER MS VLY BY EARLY TUE AFTN. ATTM...GIVEN STRENGTH OF THE EML...MOST TSTMS SHOULD BE ELEVATED ATOP THE RESIDUAL COLD DOME PRODUCED BY MORNING CONVECTION. BUT...IF SUFFICIENT HEATING AND STRONGER THAN ANTICIPATED UPPER SUPPORT MATERIALIZE...THE SFC-BASED TSTM THREAT WILL INCREASE. VERTICAL SHEAR WILL IMPROVE THROUGH THE DAY AND SUPERCELLS WILL BE POSSIBLE. ELEVATED STORM CLUSTERS WILL PRODUCE LARGE HAIL...BUT RISKS FOR DAMAGING WINDS AND TORNADOES WILL INCREASE WITH ANY SFC-BASED STORMS. ACTIVITY WILL MOVE/DEVELOP QUICKLY EWD ACROSS MI AND SRN ONTARIO TUE NIGHT AND POSSIBLY ARRIVE ACROSS THE LWR GRTLKS REGION BY EARLY WED. INSTABILITY AND SUBSEQUENT SEVERE THREATS WILL DECREASE RAPIDLY WITH EWD EXTENT...BUT AN OVERNIGHT THREAT FOR HAIL AND DAMAGING WINDS MAY EXIST UPSTREAM ACROSS THE UPPER MS VLY/MIDWEST. ..RACY.. 10/02/2006  From swody2 at goshenarc.org Wed Oct 4 05:46:47 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 04 Oct 2006 01:46:47 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040546 SWODY2 SPC AC 040545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT WED OCT 04 2006 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...GRT BASIN/INTERMOUNTAIN WEST... UPPER LOW OFF THE CNTRL CA COAST WILL GRADUALLY EDGE EWD TOWARD THE GRT BASIN AND INTERMOUNTAIN WEST ON THU. A 60+ KT BELT OF MID-LEVEL FLOW ASSOC WITH THIS SYSTEM IS EXPECTED ACROSS SRN CA NWD INTO MT. THE LOW HAS BEGUN TO TAP INTO SUB-TROPICAL MOISTURE AND PRECIPITABLE WATER VALUES SHOULD INCREASE LATE WED INTO THU...ESPECIALLY ACROSS THE GRT BASIN AND SWRN DESERTS. EMBEDDED SPEED MAXIMA WITHIN THE WARM CONVEYOR WILL CONTRIBUTE TO CONSIDERABLE CONVECTION. STRONGER STORMS WILL LIKELY FAVOR WRN EDGE OF THE MOIST AXIS ACROSS NRN AZ NWD THROUGH UT INTO ERN ID...THEN SPREAD ENEWD THU NIGHT. STEEP LAPSE RATE ENVIRONMENT COUPLED WITH NEARLY 50 KTS OF VERTICAL SHEAR WILL LIKELY RESULT IN AT LEAST ISOLD STG-SVR TSTMS /INCLUDING A BRIEF SUPERCELL RISK/ WITH DAMAGING WINDS/HAIL. GIVEN THE UNCERTAINTY ON WHEN THE UPPER LOW WILL BEGIN TO EJECT NEWD...A SLGT RISK IS NOT JUSTIFIED ATTM. ..RACY.. 10/04/2006  From swody2 at goshenarc.org Thu Oct 5 05:46:53 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 05 Oct 2006 01:46:53 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050546 SWODY2 SPC AC 050545 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT THU OCT 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SWRN DESERTS AND GRT BASIN... ...SWRN DESERTS NWD INTO THE GRT BASIN... MODELS HAVE BEEN CONSISTENT DURING PAST SEVERAL RUNS IN EJECTING THE UPPER LOW OFF THE CA COAST NEWD AS AN OPEN WAVE INTO THE GRT BASIN REGION FRI AFTN/EVE. AN EXTENSIVE WARM CONVEYOR WITH A SUB-TROPICAL TAP WILL BE ESTABLISHED ACROSS AZ INTO UT THU AND FRI. SPEED MAXIMA WITHIN THIS BELT OF ENHANCED FLOW ALONG WITH TERRAIN INFLUENCES WILL LIKELY CONTRIBUTE TO CONVECTION OVER A FAIRLY EXTENSIVE AREA FROM THE SWRN DESERTS INTO THE INTERMOUNTAIN WEST DURING THE NEXT COUPLE OF DAYS. AS THE UPPER LOW BEGINS TO EJECT...A 70+ KT SWLY JET STREAK IS EXPECTED TO TRANSLATE FROM SRN CA INTO SRN UT BY FRI AFTN. STRONG MID-LEVEL Q-VECTOR FORCING ASSOC WITH THE JETLET WILL INDUCE A SFC LOW THAT WILL TRACK NWD THROUGH ERN NV. TO THE S OF THE LOW...A FRONT WILL MOVE ENEWD INTO SWRN UT/WRN AZ EARLY FRI AFTN. SUFFICIENT HEATING SHOULD TAKE PLACE ALONG/AHEAD OF THIS FRONT AND JUST TO THE WEST OF THE WARM CONVEYOR INDUCED CLOUDS FOR SCT TSTM INITIATION. VERTICAL SHEAR AOA 50 KTS AND STEEPENING LAPSE RATES ALOFT WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL AND DAMAGING WIND GUSTS. ISOLD TORNADOES WILL BE POSSIBLE. HIGHEST SEVERE POTENTIAL ATTM APPEARS TO BE ACROSS CNTRL-NRN AZ NWD INTO WRN/CNTRL UT WHERE STRONGEST LARGE SCALE ASCENT WILL OCCUR. THOUGH THE RISK OF SUPERCELLS WILL CONTINUE INTO THE EVE...MAIN STORM MODE SHOULD EVOLVE INTO LINE SEGMENTS/SQUALL-LINE BEFORE WEAKENING OVERNIGHT ACROSS SERN ID...ERN UT AND WRN CO. ...SERN STATES... DIGGING UPPER LOW ALONG THE ATLANTIC COAST WILL INDUCE A LOW JUST OFF THE VA/NC CAPES LATE THU INTO FRI. INCREASING NLY FLOW ON THE BACKSIDE OF THIS LOW WILL FORCE A FRONT SWD ACROSS THE SERN STATES AND INTO NRN FL FRI NIGHT. A FEW TSTMS MAY ACCOMPANY THE FRONT...BUT SOUNDINGS SUGGEST THAT A WARM NOSE IN THE H7-H5 LAYER MAY INHIBIT VIGOROUS UPDRAFTS. MOREOVER...VERTICAL SHEAR WILL BE WEAK...WITH MULTICELL STORMS LIKELY FAVORED OVER ORGANIZED SVR STORMS. OTHERWISE...DEFORMATION TSTMS WILL BE POSSIBLE ACROSS SERN VA/ERN NC FRI NIGHT AS MID-LEVEL INSTABILITY INCREASES. IF THE SFC LOW DEVELOPS CLOSER TO THE COAST...THREAT FOR SFC-BASED STORMS WILL INCREASE OVER THE NC CAPES. BUT...MODELS SO FAR KEEP DEVELOPMENT OFF THE COAST. ..RACY.. 10/05/2006  From swody2 at goshenarc.org Thu Oct 5 17:22:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 05 Oct 2006 13:22:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051722 SWODY2 SPC AC 051721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT THU OCT 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FRI ACROSS PARTS OF THE SRN PLATEAU AND GREAT BASIN.... THE STRONGER BRANCH OF UPPER WESTERLIES WILL REMAIN ZONAL AT HIGHER LATITUDES...NORTH OF THE CANADIAN/U.S. BORDER...THROUGH THIS FORECAST PERIOD...WHILE A WEAKER SOUTHERN BRANCH REMAINS AMPLIFIED FROM THE EASTERN PACIFIC THROUGH THE WESTERN ATLANTIC. AS A VIGOROUS EMBEDDED NORTHERN STREAM SHORT WAVE TROUGH DIGS TO THE LEE OF THE CANADIAN ROCKIES...MODELS CONTINUE TO SUGGEST THAT A SIGNIFICANT IMPULSE WILL LIFT OUT OF THE BASE OF THE WESTERN U.S. TROUGH...NORTHEAST OF THE LOWER COLORADO VALLEY INTO THE NORTH CENTRAL ROCKIES BY EARLY SATURDAY. MEANWHILE...DOWNSTREAM OF A SEASONABLY STRONG CENTRAL STATES RIDGE...A DIGGING SHORT WAVE TROUGH IS PROGGED TO EVOLVE INTO ANOTHER CLOSED LOW OVER THE SOUTHERN MID ATLANTIC REGION. ...INTERMOUNTAIN WEST... MOISTENING FROM THE LOWER LATITUDE EASTERN PACIFIC IS ONGOING ACROSS THE SOUTHERN PLATEAU INTO THE GREAT BASIN...IN ASSOCIATION WITH DEEP LAYER SOUTHERLY FLOW AHEAD OF THE PACIFIC COAST TROUGH. THIS WILL LINGER INTO FRIDAY...AS LARGE-SCALE FORCING INCREASES WITH NORTHEASTWARD ACCELERATION OF SHORT WAVE IMPULSE OUT OF SOUTHERN CALIFORNIA. ALTHOUGH CONCERNS EXIST ABOUT POTENTIAL FOR CONSIDERABLE CLOUD COVER...STEEPENING LAPSE RATES SEEM LIKELY TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR WIDESPREAD CONVECTIVE DEVELOPMENT. EVEN WEAK CAPE...IN THE PRESENCE OF STRONG VERTICAL SHEAR ASSOCIATED WITH A 50-70 KT 500 MB JET STREAK...SHOULD BE SUFFICIENT FOR A FEW STRONG/SEVERE STORMS WITH DAMAGING WIND/HAIL POTENTIAL. ISOLATED SUPERCELLS WITH ASSOCIATED ENHANCED SEVERE THREATS ALSO APPEAR POSSIBLE...PARTICULARLY ACROSS CENTRAL ARIZONA INTO MUCH OF SOUTHERN/EASTERN UTAH...BEFORE STRONGER UPPER FORCING SPREADS NORTHEAST OF THE GREAT BASIN FRIDAY EVENING. ...MID/SOUTH ATLANTIC COAST... A SURFACE FRONT IS EXPECTED TO EXTEND ACROSS THE CAROLINAS THROUGH THE FLORIDA PANHANDLE BY 12Z FRIDAY...WITH A MOIST AIR MASS ALONG/AHEAD OF IT REMAINING SUPPORTIVE OF CONVECTIVE POTENTIAL. THE BEST CHANCE FOR STORMS APPEARS LIKELY TO ACCOMPANY THE EXIT REGION OF A STRONG CYCLONIC MID/UPPER JET STREAK...WHICH IS PROGGED TO SPREAD ACROSS EASTERN NORTH CAROLINA LATE FRIDAY AFTERNOON/EVENING. LOW-LEVEL FLOW IS EXPECTED TO REMAIN WEAK...BUT MODERATE DEEP LAYER SHEAR AND FAVORABLE CONVECTIVE INSTABILITY WILL SUPPORT RISK OF AT LEAST AN ISOLATED STORM OR TWO APPROACHING/EXCEEDING SEVERE LIMITS. ..KERR.. 10/05/2006  From swody2 at goshenarc.org Fri Oct 6 05:35:29 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 06 Oct 2006 01:35:29 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060535 SWODY2 SPC AC 060534 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 AM CDT FRI OCT 06 2006 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... HIGHLY AMPLIFIED UPPER AIR PATTERN FCST THROUGH PERIOD...CHARACTERIZED BY LARGE RIDGE OVER NERN PACIFIC...POSITIVELY TILTED TROUGH FROM SASK SWWD ACROSS SRN CA...SYNOPTIC SCALE RIDGE FROM ARKLATEX REGION TOWARD SRN QUE. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AS OPEN-WAVE TROUGH OVER MI/INDIANA/OH -- IS FCST TO DEEPEN AND CLOSE OFF AS IT APCHS CAROLINAS/GA THROUGH DAY-1 INTO DAY-2. THIS IS SOMEWHAT FARTHER S AND W OF EARLIER GUIDANCE...HOWEVER...06/00Z SHORT-RANGE DETERMINISTIC PROGS AND 05/21Z SREF MEMBERS ARE IN REMARKABLY CLOSE AGREEMENT. CONFIDENCE THEREFORE IS STRONG IN SCENARIO OF NEARLY CUT-OFF CYCLONE DRIFTING SWD OVER SC/GA COASTAL REGION DURING DAY-2. THIS PATTERN IS HIGHLY ANOMALOUS...BUT HAS A CLOSE 500 MB ANALOG FROM SEP 19-20 1989. AT SFC...WEAK/ELONGATED AREA OF LOW PRESSURE NOW ANALYZED OVER CAROLINAS PIEDMONT IS EXPECTED TO DEEPEN CONSIDERABLY AND MOVE OFFSHORE GA/SC COAST...IN RESPONSE TO APCHG UPPER LOW. FRONTAL ZONE --- NOW ANALYZED FROM OFFSHORE OUTER BANKS WSWWD ACROSS NRN LA -- WILL MOVE SWD ACROSS MUCH OF CENTRAL/ERN GULF COAST IN RESPONSE TO COASTAL CYCLOGENESIS. WARM FRONTAL SEGMENT WILL REACH NEAR NC COAST. MEANWHILE...UPPER LOW NOW OVER COASTAL CA IS FCST TO EJECT NEWD FROM YELLOWSTONE REGION ACROSS ND DAY-2...AS TROUGH NOW OVER ERN GULF OF AK DIGS SEWD INTO NRN ROCKIES. IN RESPONSE...SFC FRONTOGENESIS/CYCLOGENESIS IS FCST OVER NRN ROCKIES AND NRN HIGH PLAINS...WITH LOW DEEPENING AND MOVING NEWD OVER ND DURING DAY. SECONDARY MID/UPPER SPEED MAX...DIGGING SWD INTO MEAN TROUGH POSITION...WILL RESULT IN UPPER LOW RETROGRADING SWWD ACROSS SRN CA IN WAKE OF EJECTING SYSTEM. ...ERN NC... POTENTIAL FOR SFC-BASED CONVECTION WILL DEPEND STRONGLY ON WHETHER FRONTAL ZONE STAYS OFFSHORE -- PER WRF GUIDANCE AND MOST SREF MEMBERS -- OR REACHES COAST AS INDICATED BY OPERATIONAL NGM/SPECTRAL. CONSENSUS FCST SEEMS MOST REASONABLE ATTM FOR FRONT TO REMAIN JUST OFFSHORE...WITH INTENSE/ELEVATED CONVEYOR OF WARM/MOIST ADVECTION SUPPORTING GEN THUNDER POTENTIAL OVER NERN QUADRANT OF DEEP-LAYER CYCLONE. WRF FRONTAL POSITION DOES REACH CLOSE ENOUGH TO COAST FOR EFFECTIVE PARCELS TO BE NEARLY SATURATED AND SFC-BASED OVER IMMEDIATE SHORELINE AREAS...WITH LARGE LOW LEVEL HODOGRAPHS. SVR POTENTIAL OVER LAND APPEARS TOO ISOLATED/CONDITIONAL FOR CATEGORICAL OUTLOOK ATTM...BUT WILL INTRODUCE MRGL PROBABILITIES FOR IMMEDIATE COASTAL AREAS AND COASTAL WATERS. ...AZ... AS SECONDARY UPPER LOW TAKES SHAPE OVER SRN CA...VERTICAL SHEAR PROFILES ARE EXPECTED TO REMAIN FAVORABLE FOR SUPERCELLS AND BOWS ACROSS MUCH OF THIS REGION THROUGH DAY-2. RELATED LOW LEVEL WAA REGIME WILL CONTINUE TO YIELD RICH MOISTURE ACROSS THIS REGION...THOUGH LOW-MIDLEVEL LAPSE RATES WILL BE WEAK WITHOUT SUBSTANTIAL BOUNDARY LAYER HEATING. MAIN UNCERTAINTY PRECLUDING CATEGORICAL SVR OUTLOOK ATTM IS EXTENT OF DESTABILIZATION IN WAKE OF ABUNDANT CLOUDS/PRECIP LIKELY BETWEEN NOW AND SATURDAY AFTERNOON. ...NRN HIGH PLAINS...NRN ROCKIES... FCST SFC TRAJECTORIES FROM RELATIVELY DRY/CONTINENTAL AIR MASS OVER UPPER MIDWEST SUGGEST MOISTURE WILL BE TOO SCANT FOR SFC-BASED DEVELOPMENT ALONG FRONT OR IN WARM SECTOR. HOWEVER.,..BAND OF WIDELY SCATTERED TO SCATTERED TSTMS MAY OCCUR BEHIND SFC COLD FRONT. THIS AREA WILL BE IN REGION OF STG MIDLEVEL DPVA AND COOLING ALOFT...WITH SOME POTENTIAL FOR AFTERNOON HEATING ALONG E RIM OF CLOUD PLUME. SFC TEMPS IN LOW 70S WOULD YIELD UP TO 700 J/KG MLCAPE OVER ERN MT BY 07/21Z...BASED ON MODIFIED WRF SOUNDINGS. STRONGEST TSTMS MAY PRODUCE HAIL OR DAMAGING GUSTS. ..EDWARDS.. 10/06/2006  From swody2 at goshenarc.org Sat Oct 7 16:47:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 07 Oct 2006 12:47:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071650 SWODY2 SPC AC 071649 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1149 AM CDT SAT OCT 07 2006 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SHORT WAVE TROUGH...CURRENTLY TRACKING SWD ACROSS CENTRAL CA PER WATER VAPOR IMAGERY...IS EXPECTED TO BECOME A CUT-OFF LOW ALONG THE SRN CA COAST BY END OF DAY 1...AND THEN DRIFT SLOWLY EAST ACROSS SRN CA ON DAY 2. MEANWHILE...DEEPENING UPPER TROUGH AND ASSOCIATED STRENGTHENING SURFACE LOW WILL MOVE THROUGH WRN/NRN ONTARIO TOWARD NRN QUEBEC ON SUNDAY. DOWNSTREAM HEIGHT FALLS ACROSS OH VALLEY AND NERN STATES ARE EXPECTED TO ALLOW CAROLINAS CLOSED LOW TO TRACK SEWD OFF THE SRN ATLANTIC COAST. STRONGEST ASCENT SUPPORTIVE OF A SEVERE THREAT WITH THE CLOSED LOW SHOULD REMAIN OFFSHORE DURING DAY 2 PERIOD...THOUGH WARM CONVEYOR ABOVE SURFACE MAY SUPPORT THUNDERSTORM POTENTIAL OVER COASTAL CAROLINAS AND ADJACENT WATERS IN VICINITY OF COASTAL FRONT. ...SWRN CONUS... INCREASING MID LEVEL FLOW ALONG SERN/ERN PERIPHERY OF SRN CA CLOSED LOW IS EXPECTED TO DEVELOP ACROSS AZ BY 12Z SUNDAY AND THEN SPREAD INTO NM BY SUNDAY EVENING...RESULTING IN STRONG DEEP LAYER SHEAR FOR ORGANIZED STORMS. LARGE SCALE ASCENT AHEAD OF UPPER LOW AND COOLER MID LEVEL TEMPERATURES ATOP PERSISTENT TRANSPORT OF MOISTURE INTO THE SWRN STATES FROM THE LOWER LATITUDE ERN PACIFIC WILL SUPPORT THUNDERSTORMS ACROSS AZ/NM INTO FOUR CORNERS REGION. SURFACE DEWPOINTS IN THE UPPER 40S TO MID 50S SUGGEST INSTABILITY WILL TEND TO BE MARGINAL...THOUGH POCKETS OF MLCAPE UP TO 1000 J/KG MAY DEVELOP WHERE CLOUD BREAKS RESULT IN SUFFICIENT SURFACE HEATING. UNCERTAINTIES IN AVAILABLE INSTABILITY FOR A GREATER SEVERE THREAT PRECLUDE A CATEGORICAL OUTLOOK AT THIS TIME. HOWEVER...POTENTIAL FOR WELL-MIXED/INVERTED-V THERMODYNAMIC PROFILES MAY SUPPORT A FEW DAMAGING WIND GUSTS. ..PETERS.. 10/07/2006  From swody2 at goshenarc.org Sun Oct 8 05:24:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 08 Oct 2006 01:24:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080527 SWODY2 SPC AC 080526 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 AM CDT SUN OCT 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN NM AND FAR W TX.... ...SYNOPSIS... UPPER AIR PATTERN TRANSITION FCST BY END OF PERIOD...AS HEIGHTS RISE ACROSS SERN CONUS AND FALL FROM 4-CORNERS REGION TO UPPER GREAT LAKES. PERSISTENT RIDGING ALOFT -- NOW LOCATED FROM ARKLATEX REGION TO SRN ONT -- WILL WEAKEN AND SHIFT SEWD...AS UPPER LOW NOW OVER SRN CA EVOLVES TO STRONG OPEN-WAVE PERTURBATION AND EJECTS EWD ACROSS AZ...SONORA AND NM. THIS WILL OCCUR IN RESPONSE TO SWD MOVEMENT AND AMPLIFICATION OF SPEED MAX AND ASSOCIATED SHORTWAVE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN BC. OPERATIONAL SHORT-RANGE MODELS AND SREF MEMBERS DISAGREE ON TIMING/STRENGTH OF THESE FEATURES AT MESO-ALPHA SCALE...BUT GENERAL PATTERN BY END OF PERIOD SHOULD BE CHARACTERIZED BY DEEP/CLOSED LOW OVER NRN CA OR NV...STRONG SHORTWAVE TROUGH MOVING EWD ACROSS NM...AND POSITIVELY TILTED NRN-STREAM TROUGH MOVING EWD ACROSS LS AND NRN ONT. WEAK SHORTWAVE TROUGH -- NOW EVIDENT OVER NRN MEX S ELP -- IS PROGGED TO LIFT NEWD FROM NM ACROSS CENTRAL PLAINS DAY-1 THEN WEAKEN OVER UPPER MS VALLEY DAY-2. AT SFC...FRONTAL ZONE NOW ASSOCIATED WITH SERN CONUS LOW WILL BECOME DIFFUSE OVER CENTRAL/WRN GULF COAST REGION...AMIDST SFC RIDGING THAT WILL EXTEND FROM CENTRAL APPALACHIANS SWWD ACROSS SE TX. STRONG COLD FRONT -- NOW ANALYZED FROM NWRN MN SWWD ACROSS SERN SD...CENTRAL NEB...NERN CO -- IS EXPECTED TO MOVE THROUGH GREAT LAKES AND INTO OH VALLEY...OZARKS...WRN OK AND PORTIONS W TX/SERN NM BY 10/00Z. TX-NM FRONTAL SEGMENT MAY BECOME QUASISTATIONARY BY END OF PERIOD...BENEATH STRONG/ELEVATED LOW LEVEL WAA REGIME ASSOCIATED WITH EJECTING CA PERTURBATION. ...SWRN CONUS... SCATTERED TSTMS ARE EXPECTED ACROSS PORTIONS SRN HIGH PLAINS -- PERHAPS INTO SWRN KS -- EARLY IN PERIOD. THIS ACTIVITY MAY MOVE NEWD ACROSS PORTIONS TX PANHANDLE...WRN/NWRN OK AND SWRN KS BEFORE DISSIPATING DURING MID-LATE MORNING HOURS. THIS ACTIVITY WILL BE ASSOCIATED WITH ZONE OF JUXTAPOSED MIDLEVEL DPVA AND LOW LEVEL WAA/MOIST ADVECTION....AHEAD OF EJECTING MEXICAN SHORTWAVE TROUGH. BY START OF PERIOD...ACTIVITY SHOULD BE LARGELY N OF SFC COLD FRONT...SVR POTENTIAL HAVING ENDED DURING PREVIOUS NIGHT. REF SPC DAY-1 OUTLOOK FOR MORE DISCUSSION ON THAT REGIME. BY AFTERNOON...PRIND CLOUD BREAKS AND ASSOCIATED DIURNAL HEATING WILL PERMIT BOUNDARY LAYER TO DESTABILIZE FAVORABLY SW OF SFC COLD FRONT...ACROSS PORTIONS SERN AZ...SRN NM AND FAR W TX. SFC TEMPS UPPER 60S TO MID 70S F AND DEW POINTS LOCALLY 50-55 DEG F ARE EXPECTED...YIELDING MLCAPES 500-1000 J/KG IN MODIFIED WRF SOUNDINGS. EXPECT SFC FLOW TO VEER FROM W-E WITH TIME ACROSS ERN AND ERN AZ JUST AHEAD OF MIDLEVEL WAVE...DIMINISHING VERTICAL SHEAR AND SFC FORCING. ASSOCIATED WIND SHIFT/CONFLUENCE LINE WILL MOVE EWD ACROSS SRN NM/FAR W TX BORDERLAND REGION...COINCIDENT WITH PEAK SFC WARMING AND STRENGTHENING DEEP-LAYER SHEAR. THIS BOUNDARY...ALONG WITH LOCALIZED OROGRAPHIC ASCENT E OF LINE WHERE FLOW COMPONENT IS UPSLOPE...WILL PROVIDE SUFFICIENT LIFT BENEATH 45-55 KT 500 MB JET. FCST KINEMATIC PROFILES SUGGEST UP TO 70 KT 0-6 KM SHEAR AND -- FOR RIGHT-MOVING STORMS -- 100-150 J/KG OF 0-1 KM SRH POSSIBLE. THIS WILL SUPPORT POTENTIAL FOR SUPERCELLS AND SMALL BOWS TO DEVELOP. AFTER DARK...BULK OF CONVECTION WILL MOVE OVER SFC AIR MASS THAT WILL BE STABILIZED BY DIABATIC COOLING AND/OR POSTFRONTAL CAA. HOWEVER...STRONG MOISTURE TRANSPORT AND ISENTROPIC ASCENT ABOVE STABLE SFC LAYER MAY SUPPORT MRGL SVR POTENTIAL EWD/NEWD TOWARD PORTIONS SERN NM AND PERMIAN BASIN REGION OF W TX. ..EDWARDS.. 10/08/2006  From swody2 at goshenarc.org Sun Oct 8 17:12:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 08 Oct 2006 13:12:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081715 SWODY2 SPC AC 081714 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1214 PM CDT SUN OCT 08 2006 VALID 091200Z - 101200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN NM AND FAR W TX... ...SYNOPSIS... CLOSED MID/UPPER LEVEL LOW...NOW LOCATED OVER SRN CA COAST PER WATER VAPOR IMAGERY...IS PROGGED TO EJECT EWD ACROSS NRN SONORA/AZ INTO NM DURING DAY 2 AS UPSTREAM SRN BRITISH COLUMBIA IMPULSE DIGS SWWD FROM NRN INTERMOUNTAIN REGION...REACHING NRN CA/WRN NV BY 12Z TUESDAY. IN THE LOW LEVELS...COLD FRONT ASSOCIATED WITH STORM SYSTEM TRACKING E ACROSS ERN CANADA MONDAY IS EXPECTED TO MOVE SWD INTO OH VALLEY... THE OZARKS REGION...AND SRN PLAINS. WRN EXTENT OF THIS BOUNDARY SHOULD BECOME QUASISTATIONARY ACROSS W TX/SRN NM...ESPECIALLY BY END OF PERIOD...GIVEN DEVELOPMENT OF STRONG LOW LEVEL WAA REGIME ASSOCIATED WITH EJECTING CA SHORT WAVE TROUGH. ...SWRN CONUS... SURFACE DEWPOINTS IN THE 50S LOCATED S OF THE FRONT IN NM COMBINED WITH SURFACE HEATING SHOULD RESULT IN MLCAPE VALUES RANGING FROM 500-1000 J/KG MONDAY AFTERNOON AND EARLY EVENING TIME PERIOD. SURFACE FLOW IS EXPECTED TO VEER WITH TIME ACROSS SRN/ERN AZ...AS CA SHORT WAVE TROUGH ADVANCES EWD...WITH SURFACE WIND SHIFT/GREATEST LOW LEVEL CONVERGENCE INTO SWRN NM AND FAR W TX BY PEAK HEATING. INCREASING ASCENT AHEAD OF CA IMPULSE AND IN EXIT REGION OF ACCOMPANYING 60-65 SWLY MID LEVEL JET EXPECTED TO SUPPORT THUNDERSTORM DEVELOPMENT MONDAY AFTERNOON ACROSS SRN NM/FAR W TX AND POTENTIALLY AS FAR W AS SERN AZ BENEATH COLDER MID LEVEL TEMPERATURES. DESPITE MARGINAL INSTABILITY...STRONG UPPER FORCING AND EFFECTIVE BULK SHEAR VALUES OF 40-50 KT SUGGEST A POTENTIAL FOR ORGANIZED STORMS INCLUDING SUPERCELLS AND BOWING SEGMENTS. LOW LEVEL JET ACROSS W TX IS EXPECTED TO STRENGTHEN MONDAY NIGHT... AND WILL LIKELY MAINTAIN THUNDERSTORM ACTIVITY EWD INTO SERN NM AND ADJACENT PARTS OF W TX ATOP STABLE POST-FRONTAL AIR MASS WHERE WAA/ISENTROPIC ASCENT WILL BE MAXIMIZED. WEAK INSTABILITY AND SUFFICIENT EFFECTIVE BULK SHEAR VALUES SUGGEST AN ISOLATED SEVERE THREAT. ..PETERS.. 10/08/2006  From swody2 at goshenarc.org Tue Oct 10 06:11:09 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 10 Oct 2006 02:11:09 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100613 SWODY2 SPC AC 100613 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0113 AM CDT TUE OCT 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL GULF COAST REGION TO OH/WRN PA... ...SYNOPSIS... SIGNIFICANT PATTERN SHIFT UNDERWAY...AS UPPER LOW NOW INTENSIFYING OVER NRN NV RETROGRADES OFFSHORE CA. ANOTHER UPPER LOW -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER FAR NRN MB -- WILL DIG SWD...PHASE WITH OTHER SHORTWAVE PERTURBATIONS -- AND ENLARGE/INTENSIFY MARKEDLY. BY END OF DAY-2 PERIOD...THIS PROCESS WILL RESULT IN LARGE...DEEP...COLD CYCLONIC VORTEX COVERING MOST OF CENTRAL/ERN CONUS AND CENTERED OVER UPPER GREAT LAKES. SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN NM -- IS FCST TO EJECT EWD AND DEAMPLIFY DAY-1...AMIDST STRENGTHENING LARGE SCALE HEIGHT GRADIENTS ASSOCIATED WITH DIGGING POLAR VORTEX. AT SFC...FRONTAL ZONE NOW ANALYZED FROM NY...SWWD OVER OH AND OZARKS TO SW TX -- WILL BE OVERCOME BY INTENSE/SECONDARY COLD FRONTAL SURGE DURING THIS PERIOD. ASSOCIATED SFC CYCLOGENESIS SHOULD OCCUR OVER UPPER MS VALLEY REGION BY 11/12Z...WITH RESULTANT CYCLONE LIFTING NEWD ACROSS LS/UPPER MI REGION INTO ONT...BECOMING VERTICALLY STACKED WITH MIDLEVEL VORTEX...AND OCCLUDING. BY END OF PERIOD...SFC COLD FRONT SHOULD EXTEND FROM SWRN QUE OR SERN ONT...SWD ACROSS CAROLINAS...THEN SWWD ACROSS DEEP S TX. SREF DATA UNAVAILABLE...AND SPECTRAL MODEL STILL APPEARS TO BE TOO SLOW WITH COLD FRONT OVER TX. HOWEVER...PREVIOUSLY TOO-AGGRESSIVE OPERATIONAL WRF HAS SLOWED CONSIDERABLY IN 24 HOURS AND IS CLOSER TO ECMWF/UKMET CONSENSUS...WHICH REMAINS FAVORED FRONTAL SCENARIO. ...OH VALLEY TO CENTRAL GULF COAST... SCATTERED TSTMS IN BANDS AND CLUSTERS SHOULD FORM WITHIN OUTLOOK AREA DURING DAYLIGHT HOURS...MAIN SVR RISK BEING DAMAGING GUSTS. SVR POTENTIAL SHOULD DIMINISH CONSIDERABLY AFTER DARK...PARTICULARLY FROM TN NWD...AS ALREADY MRGL INSTABILITY WEAKENS. SFC-BASED CAPE WILL BE LIMITED ACROSS MUCH OF THIS AREA BY COMBINATION OF WEAK MIDLEVEL LAPSE RATES -- JUST ABOVE MOIST-ADIABATIC -- AND PRESENCE OF CLOUD COVER TO LIMIT SFC SOLAR HEATING. HOWEVER...EXPECT CINH TO BE WEAK AS WELL...PERMITTING CONVECTION TO DEVELOP IN ONE OR MORE LINEAR ZONES OF FAVORABLE CONVERGENCE ALONG/AHEAD OF SFC COLD FRONT. IN OH VALLEY/LE REGION...WEAK MIDLEVEL ASCENT -- ASSOCIATED WITH EJECTING REMAINS OF CURRENT SWRN TROUGH -- MAY PROVIDE SOME COOLING ALOFT IN SUPPORT OF CONVECTION. FCST SOUNDINGS SUGGEST ABOUT 30 DEG MEAN WIND COMPONENT ACROSS FRONTAL ZONE IS POSSIBLE...SUPPORTING NARROW BAND OF CONVECTION MOVING NEWD INTO ENVIRONMENT OF SFC DEW POINTS MID-UPPER 50S...AND AROUND 500 J/KG MLCAPES. PREFRONTAL LOW LEVEL FLOW GENERALLY SHOULD VEER WITH SWD EXTENT...RELATED TO INCREASING DISTANCE FROM LARGEST PRESSURE FALLS THAT ARE FCST TO OCCUR AHEAD OF EJECTING SFC CYCLONE. HOWEVER...GIVEN STRENGTH OF GRADIENT FLOW ALOFT...DEEP-LAYER SHEAR STILL WILL BE FAVORABLE FOR SVR. PRIND SFC MOISTURE AND POTENTIAL FOR AREAS OF DIABATIC HEATING WILL INCREASE SWD. NEARLY UNIDIRECTIONAL DEEP-LAYER WIND PROFILES ARE FCST...SUPPORTING MORE MULTICELLULAR/LINEAR MODES...ALTHOUGH ANY DISCRETE DEVELOPMENT WILL HAVE SUPERCELL POTENTIAL. RELATIVE MIN IN SVR POTENTIAL MAY EXIST BETWEEN OH VALLEY AND GULF STATES REGIMES...WHERE CONVERGENCE AND HEATING EACH REMAIN RELATIVELY WEAK...HOWEVER THIS IS TOO UNCERTAIN AND MESOSCALE DEPENDENT TO WARRANT BREAKING OUTLOOK INTO TWO DISTINCT CATEGORICAL AREAS ATTM. ...COASTAL/TIDEWATER VA/NC... WIDELY SCATTERED TO SCATTERED TSTMS MAY DEVELOP OVER PORTIONS OF THIS REGION -- SFC-BASED DURING DAYLIGHT HOURS ALONG/S OF FRONT. MID-UPPER LEVEL GRADIENT FLOW IS FCST TO STRENGTHEN WITH TIME IN TANDEM WITH SFC HEATING...WHILE LOW LEVEL MOIST ADVECTION FROM ATLANTIC MAINTAINS/INCREASES BOUNDARY LAYER MOISTURE. MEANWHILE...ALTHOUGH LOW LEVEL WINDS ARE FCST TO REMAIN RATHER WEAK IN WARM SECTOR -- GENERALLY 10 KT OR LESS -- FLOW SHOULD BE SLIGHTLY STRONGER AND SOMEWHAT BACKED IN SFC FRONTAL ZONE. THIS COMBINATION OF FACTORS SUGGESTS AT LEAST MRGL SVR POTENTIAL WITH A FEW TSTMS. ..EDWARDS.. 10/10/2006  From swody2 at goshenarc.org Tue Oct 10 17:28:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 10 Oct 2006 13:28:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101731 SWODY2 SPC AC 101729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT TUE OCT 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE TN VALLEY INTO THE OH VALLEY... ...SYNOPSIS... UPPER PATTERN WILL UNDERGO SIGNIFICANT AMPLIFICATION THIS PERIOD. THE SHORTWAVE TROUGH NOW OVER WRN KS WILL DEAMPLIFY AND EJECT RAPIDLY NEWD INTO THE OH VALLEY BY EARLY WEDNESDAY AS A LARGE UPPER TROUGH AMPLIFIES SSEWD THROUGH THE MS...OH AND TN VALLEYS. SEVERAL JET STREAKS AND ATTENDANT VORTICITY MAXIMA WILL ROTATE THROUGH THE UPPER TROUGH. STRONG CYCLOGENESIS WILL ACCOMPANY THIS FEATURE WITH A SURFACE LOW FORECAST OVER THE UPPER GREAT LAKES WEDNESDAY MORNING. THIS LOW WILL DEEPEN AS IT LIFTS NWD INTO SRN ONTARIO DURING THE DAY. TRAILING COLD FRONT WILL SWEEP EWD AND SEWD THROUGH THE OH AND TN VALLEYS THIS PERIOD. SWRN PORTION OF THIS BOUNDARY WILL LIKELY STALL ACROSS S TX. ...CNTRL/NRN AL AND GA...TN VALLEY THROUGH THE OH VALLEY AREA... SLY LOW LEVEL JET IS FORECAST TO STRENGTHEN OVER THE TN AND OH VALLEYS AND GREAT LAKES IN ASSOCIATION WITH DEEPENING SURFACE LOW AND AMPLIFYING UPPER TROUGH. OBSERVATIONS SHOW BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 50S FROM THE OH VALLEY SWD TO NEAR THE CNTRL GULF COAST. HIGHER DEWPOINTS ARE CONFINED TO SERN TX AND THE WRN GULF. GIVEN THAT THE LOW LEVEL JET WILL REMAIN DISPLACED FROM THE RICHER MOISTURE SOURCE...MOISTURE ADVECTION WILL BE LIMITED. WIDESPREAD CLOUDS WILL LIKELY SPREAD INTO MUCH OF THE OH AND TN VALLEY EARLY WEDNESDAY AND LIMIT OR DELAY HEATING. POTENTIAL FOR SOME HEATING WILL EXIST DURING THE LATE MORNING INTO THE AFTERNOON IN WAKE OF LEAD VORT MAX AS MID LEVEL DRY SLOT ADVANCES EWD. DESPITE LIMITED LOW LEVEL MOISTURE...SOME DESTABILIZATION MAY OCCUR AS A RESULT OF MID LEVEL COOLING ACCOMPANYING THE AMPLIFYING UPPER TROUGH AND WHERE ENOUGH CLOUD BREAKS ALLOW THE BOUNDARY LAYER TO WARM. STILL MLCAPE SHOULD REMAIN MARGINAL AND GENERALLY AOB 800 J/KG FROM THE TN INTO THE OH VALLEY. A FEW STORMS WILL LIKELY BE ONGOING OVER THE OH VALLEY EARLY WEDNESDAY IN ASSOCIATION WITH DEAMPLIFYING LEAD VORT MAX. POTENTIAL WILL EXIST FOR SOME DESTABILIZATION IN WAKE OF THIS ACTIVITY. ADDITIONAL STORMS MAY DEVELOP FROM THE OH VALLEY INTO THE TN VALLEY WITHIN ZONE OF FRONTAL FORCING AS A SECONDARY VORT MAX ROTATES THROUGH BASE OF UPPER TROUGH AND WHERE AN AXIS OF MARGINAL SBCAPE COULD DEVELOP. THESE STORMS WILL EXIST IN AN ENVIRONMENT WITH STRONG LARGELY UNIDIRECTIONAL SSWLY WIND PROFILES ACCOMPANYING THE INTENSIFYING LOW-MID LEVEL JETS. POTENTIAL WILL EXIST FOR LINE SEGMENTS WITH LEWP/BOWING STRUCTURES CAPABLE OF MAINLY DAMAGING WIND. SOME EMBEDDED SUPERCELL STRUCTURES WILL ALSO BE POSSIBLE...BUT MORE CONDITIONAL UPON DEGREE OF INSTABILITY. OVERALL THREAT APPEARS SOMEWHAT MARGINAL DUE TO POTENTIAL LIMITING FACTORS UPON THE THERMODYNAMIC ENVIRONMENT. ...CNTRL GULF COASTAL AREA... SLIGHTLY HIGHER INSTABILITY MAY DEVELOP IN THIS AREA DUE TO SLIGHTLY BETTER LOW LEVEL MOISTURE. MCS CURRENTLY OVER SERN TX MAY CONTINUE INTO THE NRN GULF EARLY WEDNESDAY. CONVECTIVE DEBRIS FROM THIS SYSTEM COULD LIMIT HEATING NEAR THE COAST. MID-UPPER FLOW WILL REMAIN QUITE STRONG IN THIS REGION RESULTING IN FAVORABLE DEEP LAYER SHEAR FOR ORGANIZED STORMS. HOWEVER...LOW LEVEL FLOW IS FORECAST TO VEER AND WEAKEN EARLY IN THE PERIOD AS THE PRIMARY LOW LEVEL JET AND CYCLOGENESIS DEVELOP WELL N. THIS SUGGESTS LOW LEVEL CONVERGENCE WILL BE WEAK...AND CONVECTIVE COVERAGE SHOULD REMAIN QUITE ISOLATED. ..DIAL.. 10/10/2006  From swody2 at goshenarc.org Sat Oct 14 05:59:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 14 Oct 2006 01:59:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140601 SWODY2 SPC AC 140600 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT SAT OCT 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN/SERN TX AND SRN LA... ...SYNOPSIS... GENERALLY FAST MID/UPPER LEVEL FLOW OF MODEST AMPLITUDE WILL PERSIST ACROSS MUCH OF THE NATION THROUGH SUNDAY. FIRST DISTURBANCE RESPONSIBLE FOR POTENTIALLY STRONG CONVECTIVE DEVELOPMENT THROUGH THE DAY 2 PERIOD WILL BE THE MID/UPPER LEVEL LOW CURRENTLY SPINNING TOWARD SRN CA. THERE CONTINUE TO BE TIMING AND AMPLITUDE DIFFERENCES WITH THIS SYSTEM AMONG THE LATEST DETERMINISTIC GUIDANCE. THROUGH LATE SUNDAY...GFS CONTINUES TO SUGGEST A MORE PROGRESSIVE AND LESS AMPLIFIED UPPER TROUGH COMPARED TO NAM-WRF. SREF MEAN APPEARS TO BE A REASONABLE COMPROMISE WITH THE HANDLING OF THIS SYSTEM AND SUGGESTS THE MID/UPPER LOW WILL OPEN UP WHILE DEVELOPING ESEWD FROM THE LOWER CO RIVER VALLEY TO NRN MEX AND THE UPPER RIO GRANDE VALLEY THROUGH EARLY MONDAY. A BELT OF INTENSIFYING SWLY MID LEVEL FLOW WILL PRECEED THE SOUTHWEST/NRN MEX TROUGH. THIS STRONG FLOW WILL EXTEND FROM NRN MEX ACROSS THE SRN PLAINS AND NWRN GULF. A SECOND DISTURBANCE OF CONCERN IS FORECAST TO EMANATE FROM THE LOWER LATITUDES AND LIFT NEWD ALONG/NEAR THE TX GULF COAST EMBEDDED WITHIN THE LARGE SCALE SWLY FLOW. WHILE MODEL TIMING DIFFERENCES WITH THIS FEATURE ARE ALSO LARGE...THERE IS STRONG CONSENSUS THAT PRONOUNCED WARM AIR ADVECTION AND RESULTANT ASCENT WILL EXIST COINCIDENT WITH A VERY MOIST AIR MASS ACROSS THE NWRN GULF...AND POSSIBLY INLAND ACROSS THE TX/LA COASTAL PLAINS. ...TX/LA GULF COAST... MOISTURE AND MASS TRANSPORT SHOULD INCREASE STEADILY THROUGH SUNDAY ALONG THE TX GULF COAST WHERE A COASTAL/WARM FRONT MAY DEVELOP INLAND ACROSS PARTS OF THE COASTAL PLAIN GIVEN INTENSIFYING LOW LEVEL SLY FLOW. LIFT ACROSS THE BOUNDARY MAY BE ENHANCED BY THE APPROACH OF THE SOUTHWEST/NRN MEXICO TROUGH...AND/OR BY LOWER AMPLITUDE IMPULSES EJECTING NNEWD FROM MEX. SURFACE DEWPOINTS IN THE LOW TO MID 70S...WEAK CAP...AND STRONG FORCING WILL ALL CONTRIBUTE TO WIDESPREAD DEEP CONVECTION ACROSS THE REGION. POTENTIALLY WIDESPREAD NATURE OF CLOUDS AND PRECIPITATION MAY TEND TO LIMIT GREATER SURFACE-BASED DESTABILIZATION INLAND FROM THE GULF. HOWEVER...FORECAST MAGNITUDE OF FORCING AND SHEAR ACROSS THE REGION MAY COMPENSATE FOR RELATIVELY LOW CAPE/WEAK LAPSE RATE ENVIRONMENT AND LEAD TO SUPERCELLS WITH A WIND AND TORNADO THREAT...EMBEDDED WITHIN A LARGER CONVECTIVE PRECIPITATION SHIELD. ...RIO GRANDE VALLEY... WARM AIR ADVECTION AND DESTABILIZATION WILL LIKELY OCCUR ACROSS PARTS OF NM AND WRN/CNTRL TX THROUGH SUNDAY AFTERNOON AND EVENING AS STRONG MID/UPPER TROUGH DEVELOPS EWD. WARM FRONT WILL ALSO LIFT ACROSS THE REGION BUT RAPID WARM SECTOR DEVELOPMENT MAY BE INHIBITED BY CLOUDS/PRECIPITATION. IN ADDITION TO STRONG ASCENT ON THE COOL SIDE OF THE BOUNDARY ACROSS TX...LIFT AND LAPSE RATES NEAR THE UPPER TROUGH MAY MARGINALLY SUPPORT HAIL FROM A FEW STORMS IN NM. SURFACE-BASED WARM SECTOR ACTIVITY APPEARS POSSIBLE OVER WEST TX AND NEARER THE RIO GRANDE AS UPPER TROUGH APPROACHES AND POSSIBLE DRYLINE SHARPENS THROUGH LATE IN THE DAY. UNCERTAINTY IN TROUGH TIMING AND STRENGTH OF INSTABILITY PRECLUDE HIGHER SEVERE PROBABILITIES ACROSS THE AREA AT THIS TIME. ..CARBIN.. 10/14/2006  From swody2 at goshenarc.org Sat Oct 14 17:20:33 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 14 Oct 2006 13:20:33 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141722 SWODY2 SPC AC 141721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SAT OCT 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS ALONG THE TX AND LA GULF COASTAL AREAS... ...TX/LA GULF COAST... SOUTHWEST FLOW ALOFT WILL REMAIN IN PLACE ACROSS THE SRN PLAINS AND WRN GULF COAST STATES AS AN UPPER-LOW MOVES SLOWLY ESEWD ACROSS AZ SUNDAY. AT THE SFC...A NEARLY STATIONARY FRONT ACROSS FAR SOUTH TX WILL LIFT NWD ALONG THE TX COAST AS A WARM FRONT SUNDAY. IN RESPONSE TO THE APPROACHING UPPER-LEVEL SYSTEM...LOW-LEVEL MOISTURE WILL RETURN QUICKLY NWD AS A 70 KT LOW-LEVEL JET INTENSIFIES ACROSS EAST AND NORTH TX SATURDAY AFTERNOON. LIFT FROM THE LOW-LEVEL JET AND STRONG CONVERGENCE ALONG THE WARM FRONT SHOULD RESULT IN THE DEVELOPMENT OF A LARGE MCS ACROSS SOUTH TX SUNDAY MORNING WITH THE MCS EXPANDING NWD ACROSS CNTRL AND SOUTHEAST TX DURING THE AFTERNOON. FORECAST SOUNDINGS FOR SUNDAY ALONG THE TX GULF COAST SHOW VEERING WINDS WITH HEIGHT RESULTING IN 0-1 KM SHEAR VALUES IN THE 20 TO 30 KT RANGE. THIS STRONG LOW-LEVEL SHEAR SHOULD BE FAVORABLE FOR ROTATING STORMS WITH TORNADO POTENTIAL ESPECIALLY CONSIDERING SFC DEWPOINTS WILL BE IN THE LOWER TO MID 70S F. THE THREAT SHOULD GRADUALLY EXPAND NORTH AND EWD DURING THE DAY AFFECTING SRN LA BY EVENING. ALTHOUGH LESS OF A THREAT...DAMAGING WINDS WILL ALSO BE POSSIBLE WITH ROTATING CELLS ESPECIALLY IN AREAS WITH LOCALLY ENHANCED INSTABILITY. ...ERN NM/WEST TX... AN UPPER-LOW OVER SRN CA TONIGHT WILL MOVE EWD ACROSS AZ SUNDAY AS A STRONG 70 KT LOW-LEVEL JET DEVELOPS ACROSS THE SRN PLAINS. THIS WILL INCREASE LOW-LEVEL MOISTURE NWD ACROSS CNTRL AND WEST TX SUNDAY WITH SFC DEWPOINTS POSSIBLY REACHING THE MID 60S F AS FAR NWWD AS THE SRN TX PANHANDLE. THIS COMBINED WITH LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-LEVEL TROUGH SHOULD RESULT IN THE DEVELOPMENT OF AN MCS ACROSS WEST TX AND PARTS OF ERN NM DURING THE AFTERNOON. HOWEVER...THE NAM AND GFS SOLUTIONS DISAGREE ON CONVECTIVE COVERAGE KEEPING THE STRENGTH OF THE CONVECTION HIGHLY UNCERTAIN. IF STORM COVERAGE REMAINS LESS AND MORE INSTABILITY DEVELOPS AS SUGGESTED BY THE GFS...A THREAT FOR HAIL AND STRONG GUSTY WINDS MAY MATERIALIZE SUNDAY AFTERNOON ACROSS THE REGION. ..BROYLES.. 10/14/2006  From swody2 at goshenarc.org Sun Oct 15 06:12:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 15 Oct 2006 02:12:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150612 SWODY2 SPC AC 150611 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0111 AM CDT SUN OCT 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX GULF COAST ACROSS THE LOWER MS VALLEY AND THE NRN GULF COAST... ...SYNOPSIS... POTENTIAL FOR SEVERE STORMS AND PERHAPS TORNADOES APPEARS TO BE INCREASING OVER PARTS OF THE NRN GULF COAST AND MS DELTA REGIONS DURING MONDAY AS A VIGOROUS SHORT WAVE IMPULSE EJECTS NEWD FROM THE SRN PLAINS. THIS WILL OCCUR DOWNSTREAM FROM STRONG HEIGHT FALLS AND LARGE SCALE TROUGH DEVELOPMENT FROM THE NORTHWEST/GREAT BASIN AREAS TO THE ROCKIES. RIDGING...SURFACE AND ALOFT...WILL REMAIN SITUATED ACROSS THE ERN SEABOARD...AND OVER FL AND THE ERN GULF OF MEX. THERE CONTINUE TO BE TIMING DIFFERENCES AMONG NAM-WRF AND GFS GUIDANCE WITH RESPECT TO THE EJECTING SHORT WAVE TROUGH. THE GFS CONTINUES TO FORECAST A MORE PROGRESSIVE IMPULSE AND LATEST NAM-WRF GUIDANCE IS TRENDING TOWARD A LESS AMPLIFIED UPPER WAVE...SIMILAR TO WHAT THE GFS HAS BEEN FORECASTING. ECMWF AND SREF MEAN ALSO SUGGEST THAT THE SHORT WAVE TROUGH WILL DEAMPLIFY WHILE ACCELERATING NEWD FROM TX/OK TO THE MIDWEST FROM MONDAY AFTERNOON THROUGH EARLY TUESDAY. LARGE SCALE FORCING ASSOCIATED WITH THE WRN U.S. TROUGH WILL INDUCE STRONG CYCLOGENESIS ACROSS THE NRN PLAINS THROUGH THE PERIOD. MEANWHILE...VERY STRONG WIND FIELDS ACCOMPANYING THE EJECTING SRN PLAINS TROUGH WILL ALLOW WARM SECTOR TO EXPAND NNEWD FROM THE UPPER TX COAST ACROSS THE LOWER MS VALLEY THROUGH THE PERIOD. ...ERN TX ACROSS THE LOWER MS VALLEY... PRONOUNCED GULF MOISTURE TRANSPORT WILL PRECEDE THE EJECTING UPPER TROUGH WITH INTENSIFYING SLY LOW LEVEL JET OF 50KT TO 70KT EXTENDING FROM THE NWRN GULF INLAND TO THE OZARKS DURING MONDAY. INTENSE DYNAMIC ASCENT ACROSS DEVELOPING WARM SECTOR WILL SUPPORT WIDESPREAD CONVECTION OVER THE REGION OF CONCERN. LATEST GUIDANCE SUGGESTS WARM SECTOR WITH 70S DEWPOINTS SHOULD EXPAND NWD AND EWD FROM ERN TX TO SRN AR...AND INTO TO MS FROM MONDAY MORNING THROUGH MONDAY NIGHT. DESPITE NEARLY MOIST ADIABATIC LAPSE RATES DEPICTED IN FORECAST SOUNDINGS...POCKETS OF WEAK TO MODEST INSTABILITY MAY DEVELOP DURING THE DAY AND SUPPORT STRONGER EMBEDDED CONVECTION. ACTIVITY NEAR THE WARM FRONT...AND NEAR ANY WEAK FRONTAL WAVES...WILL ENCOUNTER EXTREME LOW LEVEL SHEAR AND HELICITY. EFFECTIVE SRH VALUES IN EXCESS OF 500 M2/S2 WILL EASILY SUPPORT MESOCYCLONE FORMATION AND PERSISTENCE IN ANY UPDRAFTS THAT CAN REMAIN DISCRETE/LONG-LIVED. INITIALLY...ROTATING STORMS OR FAST-MOVING LINE SEGMENTS MAY REMAIN ROOTED ABOVE THE BOUNDARY LAYER...OR CROSS INTO MORE STABLE AIR MASS NORTH OF THE WARM FRONT. HOWEVER...WITH TIME...SUFFICIENT SURFACE-BASED DESTABILIZATION APPEARS POSSIBLE ACROSS THE WARM SECTOR TO SUPPORT SUPERCELLS...AND POSSIBLY LINE SEGMENTS...WITH TORNADO AND WIND DAMAGE POTENTIAL. INCREASINGLY STRONG FLOW THROUGH THE TROPOSPHERE WILL ALSO RESULT IN FAST STORM MOTION AND AN ENHANCED THREAT OF DAMAGING WINDS. AT PRESENT...GREATEST RISK APPEARS TO BE FROM ERN TX ACROSS LA AND INTO WRN MS THROUGH MONDAY NIGHT. RAPID TRANSLATION OF THE UPPER TROUGH ALSO NECESSITATES A LARGE SLGT RISK AREA GIVEN FAST STORM MOTION. PARTS OF THE REGION MAY REQUIRE HIGHER PROBABILITIES IN LATER OUTLOOKS AS DETAILS BECOME MORE CERTAIN. ..CARBIN.. 10/15/2006  From swody2 at goshenarc.org Sun Oct 15 17:22:58 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 15 Oct 2006 13:22:58 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151725 SWODY2 SPC AC 151724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT SUN OCT 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF EAST TX...LA..MS AND SRN AR... ...EAST TX/LA/MS AND SRN AR... AN UPPER-LOW OVER THE SRN ROCKIES TONIGHT IS FORECAST TO OPEN AND ADVANCE EWD INTO WEST TX MONDAY. IN RESPONSE...A VERY STRONG LOW-LEVEL JET WILL CONTINUE TO STRENGTHEN ACROSS EAST TX...WRN LA AND WRN AR WITH THE JET LIKELY REACHING 80 KT BY MONDAY AFTERNOON. IN ADDITION...WIDESPREAD LOW-LEVEL CONVERGENCE AND ISENTROPIC LIFT WITH THE LOW-LEVEL JET WILL SUPPORT A LARGE TROPICAL-LIKE MCS WHICH SHOULD GRADUALLY SPREAD NNEWD ACROSS EAST TX...WRN LA...SRN AR AND INTO WRN MS DURING THE DAY. FORECAST SOUNDINGS VALID AT 12Z MONDAY IN THE HOUSTON...BEAUMONT...LUFKIN AND LAKE CHARLES AREAS SHOW 55 TO 65 KT OF SLY FLOW AT 850 MB AND VEERING WINDS WITH HEIGHT SUGGESTING A TORNADO THREAT WILL BE ONGOING ACROSS EAST TX AND SWRN LA MONDAY MORNING. AS THE LOW-LEVEL JET INTENSIFIES AND THE LARGE MCS DRIFTS NNEWD...THE TORNADO THREAT SHOULD EXPAND INTO NRN LA...SRN AR AND WRN MS BY AFTERNOON. ANOTHER FACTOR THAT MAY INCREASE THE SEVERE THREAT LATE TONIGHT INTO MONDAY IS A MID-LEVEL JET THAT IS FORECAST TO DEVELOP ACROSS THE REGION. IN RESPONSE TO THE DEVELOPING JET...0-6 KM SHEAR WILL STEADILY INCREASE TO ABOUT 40 TO 45 KT IN EAST TX AND WRN LA BY MIDDAY SUNDAY. THIS SHOULD HELP ROTATING STORMS TO PERSIST LONGER AND A WIND DAMAGE THREAT MAY ALSO OCCUR IN ADDITION TO THE TORNADO THREAT. ...WCNTRL TX... AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE EWD INTO THE SRN PLAINS MONDAY. IN RESPONSE...FRONTOGENESIS MAY TAKE PLACE ACROSS WCNTRL TX BY MONDAY AFTERNOON. SFC HEATING...INCREASING LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY AND STRONG LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH SHOULD RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT. ALTHOUGH INSTABILITY IS FORECAST TO REMAIN RELATIVELY WEAK...COOLING TEMPS ALOFT...STRONG VERTICAL SHEAR AND STEEPENING MID-LEVEL LAPSE RATES MAY RESULT IN A MARGINAL HAIL THREAT WITH THE STRONGER THUNDERSTORMS THAT DEVELOP MONDAY AFTERNOON. ..BROYLES.. 10/15/2006  From swody2 at goshenarc.org Mon Oct 16 05:11:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 16 Oct 2006 01:11:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160513 SWODY2 SPC AC 160512 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1212 AM CDT MON OCT 16 2006 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG SHORT WAVE TROUGH CURRENTLY MOVING ACROSS THE PACIFIC NORTHWEST WILL ACT TO DISLODGE VIGOROUS IMPULSE NOW MOVING TOWARD THE SRN PLAINS. THE NORTHWEST SHORT WAVE WILL RESULT IN A LARGE SCALE DEEP UPPER TROUGH BECOMING ESTABLISHED FROM THE FOUR CORNERS...ACROSS THE ROCKIES...TO THE NRN PLAINS DURING TUESDAY. THE SRN PLAINS IMPULSE WILL DEAMPLIFY AND ACCELERATE NEWD INTO MEAN RIDGE POSITION OVER THE ERN SEABOARD. SUBTROPICAL RIDGE WILL EXPAND OVER THE GULF OF MEX WITH BELT OF MODEST WSWLY MID LEVEL FLOW PERSISTING ON THE NRN PERIPHERY OF THE RIDGE...ACROSS THE GULF COAST REGION. IN THE WAKE OF THE EJECTING LEAD SHORT WAVE IMPULSE AFFECTING THE GULF COAST/LOWER MS VALLEY THROUGH DAY 1...MOIST ONSHORE FLOW AND WARM AIR ADVECTION WILL PERSIST FROM LA TO THE FL PNHDL. ...NRN GULF COAST... SCATTERED CONVECTION APPEARS POSSIBLE EARLY IN THE PERIOD IN BROAD ZONE OF WARM AIR AND MOISTURE ADVECTION OFF THE NRN GULF. LARGE SCALE FORCING FOR ASCENT AND DEEP SHEAR ARE FORECAST TO DIMINISH THROUGH THE PERIOD AS LEAD SHORT WAVE TROUGH AND ASSOCIATED STRONGER WIND FIELDS MOVE AWAY FROM THE REGION. HOWEVER...ADEQUATE SHEAR AND INSTABILITY MAY EXIST NEAR THE IMMEDIATE GULF COAST THROUGH TUESDAY AFTERNOON TO SUPPORT A LOW PROBABILITY CHANCE OF A SEVERE STORM OR TWO. ..CARBIN.. 10/16/2006  From swody2 at goshenarc.org Mon Oct 16 17:29:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 16 Oct 2006 13:29:41 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161731 SWODY2 SPC AC 161730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT MON OCT 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN MS...AL...FL PANHANDLE... ...SYNOPSIS... UPPER AIR PATTERN THROUGH PERIOD WILL CONTINUE TO FEATURE MEAN TROUGH OVER WRN CONUS...AND POSITIVELY TILTED RIDGE FROM CENTRAL GULF NEWD TOWARD QUE. MID/UPPER LEVEL LOW -- WITH MULTIPLE CIRCULATION CENTERS EVIDENT IN VIS IMAGERY ATTM -- WILL CONTINUE TO DIG SEWD ACROSS NWRN CONUS AND GREAT BASIN. BY 18/12Z...RESULT SHOULD BE HIGH-AMPLITUDE...POSITIVELY TILTED SYNOPTIC TROUGH FROM HUDSON BAY REGION TO VICINITY SRN CA AND NRN BAJA. FOREGOING PLUME OF SW FLOW ALOFT...FROM SRN CONUS AND NRN MEX TO OH/TN VALLEY REGIONS...MAY CONTAIN SEVERAL WEAK/EMBEDDED SHORTWAVES. MEANWHILE...TROUGH NOW LOCATED OVER ERN NM AND FAR W TX WILL DAMPEN CONSIDERABLY AND ACCELERATE NEWD FROM 17/12Z POSITION OVER SE TX...MID-SOUTH AND LOWER OH VALLEY REGIONS. AT SFC...MARINE/WARM FRONT NOW ANALYZED OVER SE TX AND S-CENTRAL LA IS FCST TO LIFT SLOWLY NEWD ACROSS MS/SWRN AL INTO EARLY DAY-2. THIS FRONT MAY BECOME DIFFUSE OVER AL/GA FROM AFTERNOON ONWARD...AS BOUNDARY LAYER FLOW WEAKENS/VEERS IN RESPONSE TO WEAKENING/EJECTION OF MIDLEVEL WAVE AWAY FROM AREA. MEANWHILE...FRONTOGENESIS AND CYCLOGENESIS ARE FCST OVER CENTRAL PLAINS AHEAD OF WRN CONUS SYNOPTIC TROUGH. BY 18/00Z...EXPECT SFC LOW INVOF SERN CO/OK PANHANDLE/SWRN KS REGION...SHIFTING SEWD ACROSS OK BY 18/12Z ALONG ASSOCIATED COLD FRONT. ...CENTRAL/ERN GULF COASTAL PLAIN...EARLY PERIOD... SCATTERED TSTMS -- WITH POTENTIAL FOR SUPERCELLS...TORNADOES AND ISOLATED DAMAGING GUSTS -- ARE POSSIBLE MAINLY OVER CATEGORICAL SLGT RISK AREA DURING FIRST HALF OF PERIOD. VERY FAVORABLE LOW LEVEL SHEAR PROFILES -- NOW PRESENT ACROSS LA -- ARE EXPECTED TO SHIFT EWD GRADUALLY THROUGH REMAINDER DAY-1 PERIOD INTO EARLY-DAY2...WITH 0-1 KM SRH COMMONLY ABOVE 200 J/KG. LARGE LOW LEVEL HODOGRAPHS...VERY RICH LOW LEVEL MOISTURE...AND WEAK CINH WILL SUPPORT POTENTIAL FOR TSTMS TO DEVELOP IN WARM SECTOR AND ROTATE...MARINE FRONT REPRESENTING NRN BOUND OF MOST PROBABLE SVR THREAT. BOUNDARY LAYER WIND AND SHEAR PROFILES ARE EXPECTED TO WEAKEN WITH TIME AND FROM W-E...DURING LATTER HALF OF PERIOD...AS WEAKENING UPPER TROUGH EJECTS WELL N-NE OF AREA. ...LA...SE TX...LATE PERIOD... ALTHOUGH NOT AS STRONG AS WITH DAY-1 THREAT...VERTICAL SHEAR PROFILES MAY INCREASE ENOUGH TO SUPPORT CONDITIONAL SUPERCELL/TORNADO POTENTIAL NOCTURNALLY ACROSS THIS REGION. LOW LEVEL FLOW IS FCST TO BACK TO SLY AFTER DARK...BENEATH ABOUT 30 KT 500 MB WINDS. FCST SOUNDINGS YIELD 0-1 KM SRH 100-150 J/KG BUT ONLY 30-35 KT EFFECTIVE BULK SHEAR. AIR MASS WILL REMAIN FAVORABLY MOIST WITH SFC DEW POINTS 70S F...NEARLY MOIST-ADIABATIC DEEP-LAYER LAPSE RATES...WEAK BUT SUFFICIENT BUOYANCY TO SUPPORT DEEP CONVECTION...AND EFFECTIVE PARCELS ROOTED AT SFC. EXPECT WEAK LOW LEVEL FORCING IN ABSENCE OF SIGNIFICANT BOUNDARIES. ..EDWARDS.. 10/16/2006  From swody2 at goshenarc.org Fri Oct 20 17:23:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 20 Oct 2006 13:23:40 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201725 SWODY2 SPC AC 201724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT FRI OCT 20 2006 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...GULF COASTAL REGION... POTENT UPPER DISTURBANCE DIGGING THROUGH THE NRN ROCKIES TODAY WILL TRANSLATE TO THE SRN PLAINS EARLY SATURDAY BENEATH A BROAD TROUGH CENTERED OVER NRN ONTARIO. ASOCD COLD FRONT WILL MOVE SEWD AND REACH THE MIDWEST...THE DEEP S AND SRN TX BY 12Z SUNDAY. AHEAD OF THE FRONT...RESIDUAL FRONT ALONG THE GULF COAST WILL RETURN NWD INTO NRN AL AND GA WHILE THE MARINE FRONT REDEVELOPS TO ALONG THE IMMEDIATE GULF COAST THROUGH THE DAY SATURDAY. AS THE NEXT IMPULSE DROPS SEWD...RETURN FLOW WILL DEVELOP FROM S TX INTO THE SRN STATES LATE TONIGHT AND SATURDAY. BUT...LOW-LEVEL TRAJECTORIES WILL REMAIN WSWLY AND NOT FAVORABLE FOR THE MARITIME TROPICAL MOISTURE TO SURGE NWD. RATHER...LOW-LEVEL MOISTURE WILL GRADUALLY INCREASE WITH THE STRONGEST INSTABILITY REMAINING ALONG THE IMMEDIATE GULF COAST INVOF THE MARINE FRONT. WEAK WARM/MOIST ADVECTION WILL RESULT IN BANDS OF CONVECTION/TSTMS OVER THE WRN GULF BASIN/COASTAL TX EARLY IN THE PERIOD. THIS ACTIVITY WILL THEN DEVELOP ENEWD AHEAD OF THE APPROACHING COLD FRONT DURING SATURDAY AFTN. ADDITIONAL TSTMS WILL DEVELOP ALONG THE PRIMARY COLD FRONT ACROSS SERN/S TX SATURDAY EVE/OVERNIGHT. FORECAST SOUNDINGS ALONG THE GULF COAST SUGGEST THAT LOW-LEVEL SHEAR WILL BE SOMEWHAT LACKING...THOUGH DEEP LAYER SHEAR COULD SUPPORT ORGANIZED UPDRAFTS. GIVEN THE EXPECTED WEAK LOW-LEVEL SHEAR AND WEAK INSTABILITY/LAPSE RATES...IT APPEARS MOST TSTMS WILL REMAIN BELOW SEVERE LEVELS...THOUGH ISOLD DAMAGING WINDS/TORNADOES MAY OCCUR ALONG THE GULF COAST. DEEPENING WLY FLOW SHOULD ALLOW CONVECTION TO SPREAD INTO THE SERN STATES LATE SATURDAY NIGHT. ..RACY.. 10/20/2006  From swody2 at goshenarc.org Sat Oct 21 04:30:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 21 Oct 2006 00:30:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210431 SWODY2 SPC AC 210430 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 PM CDT FRI OCT 20 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... STRONG SFC FRONT WILL MOVE ACROSS THE CNTRL GULF STATES INTO CNTRL FL PENINSULA BY THE END OF THE PERIOD AS UPSTREAM RIDGE BUILDS INTO THE SRN PLAINS. DEEP LAYER FLOW WILL VEER AHEAD OF FRONTAL PASSAGE ACROSS THE SERN U.S. AND MID LEVEL LAPSE RATES WILL REMAIN QUITE WEAK...ON THE ORDER OF 5-5.5 C/KM...WITHIN THE WARM SECTOR. ANY THUNDERSTORMS THAT DEVELOP IN ASSOCIATION WITH FRONTAL PASSAGE SHOULD DO SO WITHIN A THERMODYNAMIC ENVIRONMENT NOT PARTICULARLY CONDUCIVE FOR STRONG/ROBUST UPDRAFTS. IN ADDITION...MEAN FLOW SHOULD BE ROUGHLY 25KT SUGGESTING ANY STORMS THAT DEVELOP WILL MAINTAIN MULTI-CELL CHARACTERISTICS. FURTHERMORE...MAJORITY OF DEEP CONVECTION WILL LIKELY CONCENTRATE OFFSHORE OVER WARMER WATERS OF THE GULF OF MEXICO...AND OVER THE GULF STREAM OFF THE FL/CAROLINA COAST LATE IN THE PERIOD. ..DARROW.. 10/21/2006  From swody2 at goshenarc.org Sat Oct 21 16:50:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 21 Oct 2006 12:50:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211651 SWODY2 SPC AC 211650 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1150 AM CDT SAT OCT 21 2006 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...CNTRL/ERN GULF STATES AND THE SERN ATLANTIC SEABOARD... VIGOROUS SHORTWAVE TROUGH ACROSS THE PLAINS TODAY WILL ROTATE EWD ACROSS THE OH VLY AND MID-ATLANTIC STATES TONIGHT AND SUNDAY. ASSOCD COLD FRONT WILL SURGE SEWD IN WAKE OF THE DISTURBANCE... REACHING THE ATLANTIC SEABOARD...NRN FL AND THE NRN GULF BASIN OVERNIGHT SUNDAY. PRIMARY FORCING FOR ASCENT WILL PASS ACROSS THE GRTLKS AND OH VLYS ON SUNDAY WITH THE DEEP LAYER FLOW ALONG THE GULF COAST AND SERN STATES LIKELY TO VEER WLY AHEAD OF THE COLD FRONT. THIS WILL NOT BE FAVORABLE FOR THE MARITIME TROPICAL AIR MASS TO SURGE NWD INTO THE REGION. LAPSE RATES ALOFT WILL ALSO BE QUITE POOR AND SFC-BASED INSTABILITY EQUALLY UNIMPRESSIVE FOR STRONG UPDRAFTS. FURTHERMORE...VERTICAL SHEAR WILL GENERALLY BE AOB 30 KTS SUGGESTING THAT TSTMS THAT DO DEVELOP WILL BE MAINTAINED IN THE MULTICELL SPECTRUM. STRONGER STORMS WILL DEVELOP OFFSHORE IN THE MORE UNSTABLE MARINE ENVIRONMENT...NAMELY OVER THE NERN GULF OF MEXICO SUNDAY AFTN AND OVER THE GULF STREAM WATERS SUNDAY NIGHT/EARLY MON. ..RACY.. 10/21/2006  From swody2 at goshenarc.org Sun Oct 22 05:29:27 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 22 Oct 2006 01:29:27 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220530 SWODY2 SPC AC 220530 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CDT SUN OCT 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...SOUTH FL... WEAK WARM ADVECTION NEAR FRONTAL ZONE MAY PROVIDE SUFFICIENT ASCENT FOR A FEW THUNDERSTORMS EARLY IN THE PERIOD ACROSS SOUTH FL. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUFFICIENT INSTABILITY WILL EXIST THE FIRST 3-6 HOURS FOR ISOLATED THUNDERSTORMS...HOWEVER RAPIDLY WEAKENING LAPSE RATES AND COLD ADVECTION WILL NEGATE CONVECTIVE THREAT BY 18Z. ...SWRN U.S... MID LEVEL MOISTENING WILL SPREAD NWD ACROSS NWRN MEXICO TOWARD SRN AZ DURING THE LATE AFTERNOON HOURS MONDAY. WITH STEEP MID LEVEL LAPSE RATES IN PLACE...IT APPEARS SUFFICIENT INSTABILITY WILL DEVELOP WITHIN WARM CONVEYOR FOR A FEW THUNDERSTORMS AHEAD OF UPPER TROUGH. HOWEVER...MORE MEANINGFUL DEEP CONVECTION WILL REMAIN SUPPRESSED SOUTH OF THE BORDER. ..DARROW.. 10/22/2006  From swody2 at goshenarc.org Sun Oct 22 16:04:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 22 Oct 2006 12:04:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221605 SWODY2 SPC AC 221604 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1104 AM CDT SUN OCT 22 2006 VALID 231200Z - 241200Z ...NO SVR TSTM AREAS FORECAST... ...S FL... COLD FRONT WILL MOVE SWD ACROSS S FL ON MON AFTN...PRECEDED BY A PRE-FRONTAL TROUGH. WARM SECTOR AIR MASS WILL BE SUFFICIENTLY UNSTABLE TO SUPPORT ISOLD TSTMS...PRIMARILY DURING THE EARLY PART OF THE DAY. NO SVR WEATHER IS ANTICIPATED. ...INTERNATIONAL BORDER AZ/NM... DEVELOPING WARM CONVEYOR AHEAD OF THE UPR LOW SEVERAL HUNDRED MILES W OF BAJA CA WILL CONTRIBUTE TO GRADUAL MOISTENING OF THE MID-UPR TROPOSPHERE MON NIGHT ACROSS NRN MEXICO AND THE BORDER REGIONS OF AZ/NM. THERMODYNAMIC PROFILES BECOME SUFFICIENTLY UNSTABLE BY DAYBREAK TUE TO SUPPORT ISOLD GENERAL TSTMS AS FAR N AS EXTREME SRN AZ/NM. MOST TSTMS WILL BE ACROSS NWRN MEXICO. ..RACY.. 10/22/2006  From swody2 at goshenarc.org Mon Oct 23 05:25:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 23 Oct 2006 01:25:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230526 SWODY2 SPC AC 230525 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1225 AM CDT MON OCT 23 2006 VALID 241200Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SWRN U.S...SRN PLAINS... UPPER RIDGING WILL GRADUALLY BREAK DOWN OVER THE SRN PLAINS TUE AS SEVERAL WEAK SHORTWAVE TROUGHS EJECT NEWD ACROSS NRN MEXICO INTO THE SRN ROCKIES/TX REGION. THESE FEATURES WILL ENHANCE WARM ADVECTION PROFILES DOWNSTREAM...WHILE ALLOWING MID LEVEL MOISTENING/WEAK ELEVATED DESTABILIZATION WITHIN A PLUME THAT SHOULD STRETCH NEWD ACROSS WEST TX INTO OK. LATEST GUIDANCE SUGGESTS BOUNDARY LAYER MODIFICATION ACROSS THE WRN GULF OF MEXICO WILL BE IMPEDED BY SFC RIDGING...THUS FORECAST PROFILES ARE NOT PARTICULARLY UNSTABLE INLAND. EVEN SO...ISOLATED THUNDERSTORMS MAY EVOLVE WITHIN ELEVATED CONVECTION ACROSS OUTLOOK AREA. UPSTREAM...BOUNDARY LAYER DESTABILIZATION SHOULD BE MAXIMIZED NEAR THE LOWER CO RIVER VALLEY BENEATH COOLING MID LEVEL TEMPERATURES OF TROUGH AXIS. ISOLATED THUNDERSTORMS SHOULD EVOLVE ACROSS SERN CA INTO PORTIONS OF AZ DURING THE AFTERNOON HOURS. ...PACIFIC NW... STRONG SHORTWAVE TROUGH WILL DIG SEWD INTO THE PACIFIC NW EARLY IN THE PERIOD...WITH FOCUSED ASCENT EXPECTED WITHIN EXIT REGION OF JET AXIS. ISOLATED THUNDERSTORMS COULD EVOLVE WITHIN THIS ZONE FROM SERN B.C. INTO THE ID PANHANDLE...AND PERHAPS WRN MT. ADDITIONALLY...STRONG COLD ADVECTION IN THE WAKE OF FRONTAL PASSAGE SHOULD ENHANCE MARITIME BOUNDARY LAYER INSTABILITY ACROSS NWRN WA. A FEW THUNDERSTORMS SHOULD DEVELOP ACROSS THIS REGION THROUGH 00Z/25TH...THEN WARM ADVECTION WILL WEAKEN LAPSE RATES AND CONVECTION SHOULD WANE. ..DARROW.. 10/23/2006  From swody2 at goshenarc.org Wed Oct 25 05:18:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 25 Oct 2006 01:18:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 250521 SWODY2 SPC AC 250520 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1220 AM CDT WED OCT 25 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN PORTIONS OF THE SRN PLAINS/EAST TX INTO THE CNTRL GULF COAST STATES... LATEST NAM/GFS MODEL GUIDANCE IS NOTICEABLY SLOWER IN EJECTING UPPER LOW EWD ACROSS OK DURING THE DAY2 PERIOD. THIS SLOWER EVOLUTION WILL SIMPLY ALLOW NARROW MOIST AXIS TO ESTABLISH ITSELF A BIT FARTHER WEST ACROSS ERN OK INTO NERN TX PRIOR TO AFTERNOON CONVECTIVE DEVELOPMENT. LATEST THINKING IS STRONG DYNAMIC SYSTEM WILL FORCE LEE CYCLONE SEWD INTO NCNTRL OK BY LATE AFTERNOON...BEFORE WARM ADVECTION DRIVES SFC LOW EWD TOWARD THE BOOT HEEL OF MO BY THE END OF THE PERIOD. THE POTENTIAL FOR SEVERE THUNDERSTORM DEVELOPMENT WILL FOCUS MAINLY ACROSS ERN OK INTO AR WHERE GREATEST FORCING WILL COINCIDE WITH STEEPER LAPSE RATE PLUME THAT SHOULD OVERSPREAD THE FRONTAL BOUNDARY...ENHANCING SBCAPE TO VALUES APPROACHING 1000 J/KG. STRONGLY FORCED BAND OF THUNDERSTORMS SHOULD DEVELOP ALONG COLD FRONT BY 21Z ACROSS ERN OK INTO NERN TX. SEVERE SQUALL LINE WITH DAMAGING WINDS AND LARGE HAIL APPEAR TO BE THE GREATEST THREATS. HOWEVER...SUPERCELL STRUCTURES ARE CERTAINLY POSSIBLE GIVEN THE FORECAST SHEAR PROFILES...ESPECIALLY EARLY IN THE CONVECTIVE CYCLE. IF BOUNDARY LAYER DEW POINTS CAN INDEED RISE INTO THE UPPER 60S AS SUGGESTED BY LATEST GUIDANCE...ISOLATED TORNADOES CAN NOT BE RULED OUT. OTHERWISE...SUSTAINED PLUME OF WARM ADVECTION-INDUCED THUNDERSTORMS WILL STRETCH SW-NE ACROSS THE COASTAL PLAINS OF TX INTO LA...MAINTAINING A WEAK-NEUTRAL LAPSE RATE PROFILE AND SUPPRESSING DIABATIC HEATING. EVEN SO...STRONG STORMS WILL LIKELY DEVELOP ALONG THE ENTIRE FRONTAL BOUNDARY AS IT SURGES EWD ACROSS THE LOWER MS VALLEY REGION DURING THE OVERNIGHT HOURS. DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT AS SQUALL LINE MATURES AND RACES EWD...EVENTUALLY WEAKENING DOWNSTREAM LATE IN THE PERIOD WHERE INSTABILITY WILL BE NOTABLY WEAKER. ..DARROW.. 10/25/2006  From swody2 at goshenarc.org Thu Oct 26 05:36:15 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 26 Oct 2006 01:36:15 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 260539 SWODY2 SPC AC 260538 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CDT THU OCT 26 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE GULF COAST REGION... STRONG DYNAMIC UPPER LOW WILL EJECT ACROSS OK/TX DURING THE DAY1 PERIOD INTO THE LOWER MS VALLEY BY 27/12Z...WITH A SHARP FRONTAL ZONE EXTENDING SWD FROM A SFC LOW OVER AR INTO LA. THIS BOUNDARY WILL LIKELY REMAIN QUITE ACTIVE WITH THUNDERSTORMS THROUGH THE LATE DAY1 PERIOD INTO DAY2 WITH A WELL FORCED SQUALL LINE EXPECTED TO BE ONGOING AT THE BEGINNING OF THE PERIOD. SFC RIDGING OVER THE CNTRL/ERN GULF COAST WILL INITIALLY PROVE QUITE HOSTILE IN BOUNDARY LAYER RECOVERY AHEAD OF THIS SYSTEM. ADDITIONALLY...CONSIDERABLE AMOUNT OF RAIN WILL SLOW RECOVERY PROCESS INLAND FROM CNTRL MS INTO CNTRL GA. INITIALLY IT APPEARS GREATEST BOUNDARY LAYER MOISTENING WILL OCCUR ACROSS THE UPPER TX COAST/SWRN LA WHERE SFC DEW POINTS ARE RISING THROUGH THE 60S TO NEAR 70F. MUCH OF SRN LA INTO THE FL PANHANDLE SHOULD EASILY DESTABILIZE AS LLJ VEERS AND SFC WARM FRONT LIFTS NWD INTO PORTIONS OF CNTRL AL/WCNTRL GA BY 18Z. AT THIS TIME INSTABILITY SUFFICIENT FOR SEVERE SUPERCELLS MAY BE LIMITED TO THE SRN GULF STATES. NAM IS MORE AGGRESSIVE IN BOUNDARY LAYER RECOVERY THAN THE GFS WHICH AT TIMES IS SLOW TO BRING MOISTURE INLAND. EVEN SO...STRENGTH OF UPPER SYSTEM SUGGESTS AN ORGANIZED SQUALL LINE WILL PROGRESS EWD ACROSS THE GULF STATES...WHILE THE POSSIBILITY EXISTS FOR DISCRETE SUPERCELL STRUCTURES AND ISOLATED TORNADOES...AHEAD OF MAIN LINE WHERE SUFFICIENT BOUNDARY LAYER INSTABILITY CAN DEVELOP. ...CAROLINAS... LATER IN THE PERIOD...WELL DOWNSTREAM...NAM AGGRESSIVELY FORCES HIGHER MOISTURE JUST INLAND ALONG THE CAROLINA COAST. THIS SCENARIO SEEMS PLAUSIBLE GIVEN THE EXPECTED INCREASE IN LLJ AFTER 00Z ACROSS THIS REGION. IF HIGHER THETA-E AIRMASS DOES INDEED SPREAD INTO THE COASTAL CAROLINAS THE POTENTIAL FOR TORNADOES WILL CERTAINLY INCREASE. HOWEVER...THERE REMAINS ENOUGH UNCERTAINTY IN BOUNDARY LAYER RECOVERY INLAND TO MAINTAIN LOW PROBABILITIES FOR SEVERE AT THIS TIME. WILL CONTINUE TO MONITOR THIS REGION FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ..DARROW.. 10/26/2006  From swody2 at goshenarc.org Fri Oct 27 05:42:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 27 Oct 2006 01:42:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 270545 SWODY2 SPC AC 270544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT FRI OCT 27 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... AMPLIFICATION IN THE NORTHERN BRANCH OF THE POLAR WESTERLIES APPEARS UNDERWAY...MUCH AS SUGGESTED BY THE MODELS...WITH A STRONG MID/UPPER JET STREAK NOSING AROUND A BUILDING UPPER RIDGE ACROSS THE EAST CENTRAL PACIFIC INTO THE CANADIAN/NORTHERN U.S. ROCKIES. EXIT REGION OF THIS JET STREAK...AND AN ASSOCIATED SHORT WAVE TROUGH...ARE PROGGED INTO THE UPPER GREAT LAKES REGION BY 12Z SATURDAY...BEFORE CONTINUING TO DIG SOUTHEASTWARD AND MERGING WITH A SOUTHERN BRANCH IMPULSE LIFTING OUT OF THE CENTRAL GULF STATES AND TENNESSEE VALLEY. CONSOLIDATING IMPULSES WILL LIKELY EVOLVE INTO A DEEPENING LOW/MID-LEVEL CYCLONE OVER THE LOWER GREAT LAKES/ ST. LAWRENCE VALLEY REGION LATE SATURDAY INTO EARLY SUNDAY. ...ATLANTIC SEABOARD... VARIABILITY EXISTS AMONG THE MODELS CONCERNING THE DETAILS OF SURFACE LOW DEVELOPMENT ACROSS THE NORTHERN MID ATLANTIC COAST STATES EARLY IN THE FORECAST PERIOD...ASSOCIATED WITH THE SOUTHERN STREAM IMPULSE. IN ALL LIKELIHOOD THOUGH...STRONG WIND FIELDS/SHEAR PROFILES SUPPORTIVE OF A DAMAGING WIND/TORNADO THREAT WILL EXIST IN A MOIST PRE-FRONTAL ENVIRONMENT FROM EASTERN NORTH CAROLINA INTO THE CENTRAL/SOUTHERN FLORIDA PENINSULA AT 12Z SATURDAY. HOWEVER...MODELS CONTINUE TO INDICATE THAT THERMODYNAMIC PROFILES IN THIS REGIME WILL BE NEARLY SATURATED...WITH LAPSE RATES TRENDING TOWARD MOIST ADIABATIC AND SUPPORTIVE OF ONLY VERY WEAK CAPE. THUS...ALTHOUGH A BROKEN SQUALL LINE MAY BE ONGOING ALONG/JUST AHEAD OF SURFACE FRONT...POTENTIAL FOR INTENSIFICATION SEEMS LIMITED BEFORE ACTIVITY PROGRESSES OFFSHORE. THE WINDOW OF OPPORTUNITY MAY BE SMALL AS WELL...AS LOW-LEVEL FLOW FIELDS ACROSS THE MIDDLE AND SOUTHERN ATLANTIC SEABOARD ARE PROGGED TO VEER TO WESTERLY BY MID DAY SATURDAY...IN THE WAKE OF THE SOUTHERN STREAM SHORT WAVE TROUGH AXIS. ASSOCIATED COOLING AND DRYING OF LOWER LEVELS WILL END CONVECTIVE THREAT. ..KERR.. 10/27/2006  From swody2 at goshenarc.org Sun Oct 29 17:11:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 29 Oct 2006 12:11:07 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 291714 SWODY2 SPC AC 291713 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1113 AM CST SUN OCT 29 2006 VALID 301200Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PHASED NRN AND SRN STREAM TROUGHS WILL MOVE EWD ACROSS THE PLAINS THIS PERIOD. AS THIS OCCURS...A SURFACE COLD FRONT WILL SURGE SEWD ACROSS THE PLAINS...AND SHOULD EXTEND FROM THE UPPER GREAT LAKES REGION SSWWD INTO THE MID MS/LOWER OH VALLEY...AND THEN SWWD ACROSS THE ARKLATEX INTO TX. CAPPING COMBINED WITH A GENERAL LACK OF LOW-LEVEL MOISTURE/INSTABILITY SHOULD LIMIT CONVECTIVE POTENTIAL ALONG MOST OF FRONTAL ZONE THROUGH THE END OF THE PERIOD. ...SERN KS/ERN OK/MO/SRN IL/AR... GREATEST CONVECTIVE THREAT APPEARS TO EXIST ACROSS PARTS OF MO DURING THE LATTER HALF OF THIS PERIOD...AS LIMITED BOUNDARY LAYER MOISTURE RETURNS NWD FROM THE GULF INTO MO/ERN OK/AR AHEAD OF FRONT. THOUGH LOW-LEVEL CAPPING AND MINIMAL INSTABILITY SHOULD LIMIT POTENTIAL COVERAGE AND INTENSITY OF CONVECTION...DEGREE OF QG FORCING SUGGESTS THAT SCATTERED/WEAK STORM DEVELOPMENT MAY OCCUR INVOF FRONT AFTER SUNSET. WITH INSTABILITY FORECAST TO BE MINIMAL...WILL NOT INTRODUCE ANY SEVERE PROBABILITIES ATTM. ..GOSS.. 10/29/2006  From swody2 at goshenarc.org Mon Oct 30 06:28:41 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 30 Oct 2006 01:28:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 300631 SWODY2 SPC AC 300630 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CST MON OCT 30 2006 VALID 311200Z - 011200Z ...NO SVR TSTM AREAS FORECAST... A VIGOROUS SHORT WAVE TROUGH IN THE NORTHERN BRANCH OF THE POLAR WESTERLIES AND WEAK BROAD TROUGHING IN THE SOUTHERN STREAM ARE NOW CONTRIBUTING TO THE EVOLUTION OF A LARGE SCALE TROUGH FROM THE INTERMOUNTAIN WEST INTO THE PLAINS...MUCH AS PROGGED BY THE MODELS THE PAST FEW DAYS. AND...MODELS CONTINUE TO INDICATE THAT CYCLONIC UPPER FLOW WILL DEVELOP EASTWARD THROUGH THE ATLANTIC SEABOARD LATER TODAY THROUGH TUESDAY/TUESDAY NIGHT. THIS IS FORECAST TO OCCUR AS THE NORTHERN IMPULSE PIVOTS AROUND THE SOUTHERN/EASTERN PERIPHERY OF A BROAD CIRCULATION NOW FORMING OVER THE CANADIAN PRAIRIES...AND INCREASINGLY SHEARED SOUTHERN IMPULSE ACCELERATES ACROSS THE OZARK PLATEAU/MIDDLE MISSISSIPPI VALLEY THROUGH THE MID ATLANTIC REGION BY 12Z WEDNESDAY. ANOTHER IMPULSE IN THE SOUTHERN STREAM IS PROGGED TO SHIFT ACROSS SOUTHERN CALIFORNIA/NORTHERN BAJA INTO THE FOUR CORNERS STATES AND NORTHERN MEXICAN PLATEAU TUESDAY. IN RESPONSE TO THIS FEATURE... COLD FRONT ASSOCIATED WITH INITIAL NORTHERN BRANCH SHORT WAVE WILL PROBABLY SLOW OR STALL OVER PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST TEXAS. NORTHERN PORTION OF THE FRONT IS PROGGED TO SURGE EAST OF THE UPPER MISSISSIPPI VALLEY INTO THE NORTH ATLANTIC COAST...TO THE SOUTH/EAST OF ASSOCIATED DEEP OCCLUDING SURFACE LOW OVER ONTARIO. ...LOWER MISSISSIPPI VALLEY... AS BULK OF SOUTHERN STREAM TROUGH SHIFTS WELL TO THE EAST/NORTHEAST OF REGION EARLY IN THE PERIOD...LOW LEVEL FLOW FIELDS AHEAD OF SURFACE FRONT ARE FORECAST TO VEER AND WEAKEN. MID-LEVEL FLOW IS PROGGED TO WEAKEN AS WELL...BUT COULD REMAIN STRONG ENOUGH TO MAINTAIN AT LEAST MODERATE DEEP LAYER SHEAR INTO THE PEAK AFTERNOON HEATING HOURS TUESDAY. PRE-FRONTAL ENVIRONMENT DOES APPEAR LIKELY TO CONTINUE TO MOISTEN WITH ADVECTION OFF THE WESTERN GULF OF MEXICO. AND...MODELS SUGGEST A WEAK TO MODERATE CONDITIONALLY AND CONVECTIVELY UNSTABLE ENVIRONMENT WILL EVOLVE BY TUESDAY AFTERNOON FROM UPPER TEXAS COASTAL AREAS INTO NORTHERN MISSISSIPPI. THOUGH STRENGTH OF LARGE-SCALE FORCING IS UNCERTAIN...MODELS INDICATE WEAKENED INHIBITION ALONG A LINGERING MID-LEVEL SHEAR AXIS...WHICH MAY ALLOW THE INITIATION OF SCATTERED THUNDERSTORM ACTIVITY. IF THIS OCCURS...CAPE OF 1000-1500 J/KG COULD SUPPORT AN ISOLATED STRONG/SEVERE STORM OR TWO CAPABLE OF MARGINALLY SEVERE HAIL...POSSIBLY A DOWNBURST. ..KERR.. 10/30/2006  From swody2 at goshenarc.org Mon Oct 30 18:01:24 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 30 Oct 2006 13:01:24 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 301804 SWODY2 SPC AC 301803 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 1203 PM CST MON OCT 30 2006 VALID 311200Z - 011200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... BROAD BELT OF CYCLONIC MID-LEVEL FLOW /ANCHORED BY VORTEX OVER CNTRL CANADA/ WILL PERSIST THROUGH THE DAY TWO PERIOD OVER MUCH OF THE CONUS. WITHIN THIS REGIME...SRN STREAM SHORT WAVE TROUGH /NOW NEAR THE 4-CORNERS REGION/ IS FORECAST TO WEAKEN AS IT TRANSLATES FROM THE ARKLATEX/LOWER MS VALLEY EWD INTO THE TN VALLEY AND CNTRL GULF COAST STATES. IN THE LOW-LEVELS...SURFACE COLD FRONT INITIALLY FROM THE LOWER OH VALLEY SWWD INTO WRN TX WILL PUSH SEWD AND LIKELY EXTEND FROM WRN OR MIDDLE TN SWWD THROUGH THE ARKLATEX REGION BY LATE TUESDAY AFTERNOON. THIS BOUNDARY WILL BE THE PRIMARY FOCUS FOR TSTM DEVELOPMENT THROUGH THE PERIOD. ...OZARK PLATEAU SWD INTO THE LOWER MS VALLEY... AS MENTIONED IN CURRENT DAY ONE CONVECTIVE OUTLOOK...SOME POTENTIAL FOR ISOLATED SEVERE STORMS WILL EXIST AT THE ONSET OF THE PERIOD OVER THE OZARK PLATEAU WITHIN ZONE OF LOW-LEVEL WAA AHEAD OF SRN STREAM IMPULSE AND ASSOCIATED SURFACE COLD FRONT. THIS ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF DAY EWD INTO THE TN VALLEY...THOUGH STORMS SHOULD TEND TO DIMINISH IN INTENSITY AS FORCING FOR ASCENT DECREASES AND STORMS SHIFT AWAY FROM THE STRONGER INSTABILITY OVER THE LOWER MS VALLEY. POTENTIAL FOR ADDITIONAL SURFACE-BASED STORM DEVELOPMENT WILL INCREASE BY AFTERNOON ALONG OR AHEAD OF THE FRONT OVER LA WITHIN A MOIST LOW-LEVEL AIR MASS CHARACTERIZED BY DEWPOINTS IN THE 60S AND RESULTANT MLCAPES OF 1000-1500 J/KG. PRIMARY UNCERTAINTY IS DEGREE OF FORCING AS: 1) IT APPEARS THAT SHORT WAVE TROUGH MAY HAVE SHIFTED TO THE E PRIOR TO PEAK HEATING/TIME OF STRONGEST INSTABILITY...AND 2) APPARENT SHALLOW FRONTAL ZONE. SHOULD DEEP...MOIST CONVECTION INITIATE AND BECOME SUSTAINED...POTENTIAL WILL EXIST FOR A FEW SEVERE STORMS CAPABLE OF HAIL/LOCALLY DAMAGING WINDS GIVEN THE MODERATE INSTABILITY AND 35-40 KTS OF DEEP-LAYER SHEAR. ONLY LOW SEVERE PROBABILITIES WILL BE INCLUDED ATTM OWING TO UNCERTAINTY IN CONVECTIVE EVOLUTION. ..MEAD.. 10/30/2006