From swody1 at goshenarc.org Tue Aug 1 00:53:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 31 Jul 2006 20:53:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010053 SWODY1 SPC AC 010051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 PM CDT MON JUL 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PORTIONS OF THE UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PARTS OF UPSTATE NY INTO WRN/CNTRL NEW ENGLAND... ...UPPER GREAT LAKES... CLUSTERS OF TSTMS ARE ONGOING THIS EVENING ALONG AND AHEAD OF SURFACE COLD FRONT FROM THE ARROWHEAD SWWD INTO ERN SD WITHIN MODERATE TO STRONGLY UNSTABLE ENVIRONMENT CHARACTERIZED BY MLCAPES OF 1500-3500 J/KG. HIGH RESOLUTION RADAR IMAGERY SUGGESTS THAT THE COMBINATION OF FRONTAL SURGE AND COLD POOL GENERATION HAVE LARGELY UNDERCUT MUCH OF THIS ACTIVITY...AND THIS TEND SHOULD LIMIT A MORE ORGANIZED SEVERE THREAT. 00Z SOUNDINGS FROM INL/MPX INDICATE THAT STRONGEST DEEP-LAYER SHEAR IS DISPLACED TO THE N OF STRONGER INSTABILITY IN PLACE ACROSS E-CNTRL MN INTO NRN WI. BASED ON THIS INFORMATION...IT APPEARS THE GREATEST SEVERE THREAT WILL EXIST FROM PORTIONS OF CNTRL MN EWD INTO NWRN WI WHERE STRONGEST INSTABILITY WILL BE CO-LOCATED WITH SRN FRINGE OF MARGINALLY STRONG DEEP LAYER SHEAR. THE MOST INTENSE STORMS WILL REMAIN CAPABLE OF LOCALLY DAMAGING WINDS AND SOME SEVERE HAIL. ...PORTIONS OF UPSTATE NY INTO WRN/CNTRL NEW ENGLAND... VISIBLE SATELLITE AND LIGHTNING DATA INDICATE THE GRADUAL ORGANIZATION OF A NW-SE ORIENTED BAND OF TSTMS FROM SWRN QUEBEC INTO THE NRN ADIRONDACKS...DRIVEN LARGELY BY LOW-LEVEL WAA N OF RETREATING SURFACE WARM FRONT. 00Z SOUNDINGS FROM BUF AND ALB SHOW THAT INSTABILITY REMAINS SOMEWHAT MARGINAL OWING TO THE WEAK MID-LEVEL LAPSE RATES WITH MLCAPES OF AROUND 500 J/KG. HOWEVER THESE SOUNDINGS AND BURLINGTON VT VWP INDICATE STRONG LOW-LEVEL VEERING WITH HEIGHT WITH 45-55 KTS OF DEEP-LAYER SHEAR. STRENGTHENING WLY LLJ FROM THE UPPER MIDWEST INTO THE ST. LAWRENCE VALLEY SHOULD SUPPORT REGENERATIVE TSTM DEVELOPMENT OVERNIGHT FROM SWRN QUEBEC INTO PORTIONS OF UPSTATE NY AND WRN NEW ENGLAND. DESPITE THE MARGINAL INSTABILITY...THE RELATIVELY STRONG SHEAR SHOULD SUPPORT A FEW ORGANIZED STORMS /INCLUDING SUPERCELLS AND BOWING STRUCTURES/ CAPABLE OF MAINLY DAMAGING WINDS AND PERHAPS SOME HAIL. ..MEAD.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 05:38:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 01:38:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010538 SWODY1 SPC AC 010536 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1236 AM CDT TUE AUG 01 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER GREAT LAKES INTO THE MID MO VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE UPPER HUDSON VALLEY INTO NRN AND CNTRL NEW ENGLAND... ...SYNOPSIS... A RATHER LOW-AMPLITUDE...PROGRESSIVE LARGE-SCALE PATTERN WILL EXIST ACROSS SRN CANADA AND THE NRN TIER OF STATES DURING THE DAY ONE PERIOD. WITHIN THIS REGIME...STRONG SHORT WAVE TROUGH OVER WRN ONTARIO WILL TRANSLATE EWD INTO QUEBEC...EFFECTIVELY LOWERING HEIGHTS OVER THE ST. LAWRENCE VALLEY DURING THE LATTER HALF OF THE FORECAST. MEANWHILE TO THE W...PRIMARY SHORT WAVE TROUGH /NOW OVER NV/ WILL TEND TO DE-AMPLIFY AS IT LIFTS NEWD INTO THE NRN PLAINS. A WEAKER IMPULSE /CURRENTLY OVER THE CNTRL ROCKIES/ WILL PRECEED THE NV WAVE INTO THE CNTRL PLAINS WHILE SHEAR AXIS OVER NM SLOWLY SHIFTS EWD INTO THE CNTRL/SRN HIGH PLAINS. IN THE LOW-LEVELS...NW-SE ORIENTED WARM FRONT WILL LIFT NEWD THROUGH NEW ENGLAND TODAY WHILE TRAILING FRONTAL BOUNDARY SLOWLY SAGS SWD THROUGH THE UPPER GREAT LAKES AND CNTRL PLAINS REGIONS. SURFACE LOW PRESSURE INITIALLY OVER NWRN KS WILL DEVELOP NEWD ALONG THIS BOUNDARY INTO THE MID MO VALLEY BY THIS EVENING. ...UPPER GREAT LAKES INTO MID MO VALLEY... AS MENTIONED ABOVE...WEAKER SHORT WAVE TROUGH /NOW LIFTING NEWD INTO WY/ WILL PRECEDE PRIMARY WAVE WITH FORCING FOR ASCENT ASSOCIATED WITH THIS FEATURE SHIFTING EWD INTO PLAINS FAIRLY EARLY IN THE DAY. AS A CONSEQUENCE...LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT CONSIDERABLE CLOUDS/PRECIPITATION MAY EXIST NEAR OR JUST N OF FRONTAL ZONE FROM NEB INTO SRN MN...WHICH COULD LIMIT THE DEGREE OF DESTABILIZATION. IT DOES APPEAR THAT AIR MASS S OF FRONTAL ZONE OVER KS NEWD INTO THE MIDWEST WILL EXPERIENCE STRONG DIABATIC HEATING...WHICH WHEN COUPLED WITH MODEST BOUNDARY LAYER MOISTURE...WILL SUPPORT MLCAPES OF 1000-2500 J/KG. DIURNAL TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY BY MID TO LATE AFTERNOON ALONG FRONT OR DIFFERENTIAL HEATING/OUTFLOW BOUNDARIES FROM THE CNTRL HIGH PLAINS NEWD THROUGH THE MID MO VALLEY INTO WI AND PORTIONS OF LOWER MI. FORECAST SOUNDINGS INDICATE MODESTLY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL WITH QUITE WEAK WIND FIELDS ABOVE 6-7 KM AGL...ESPECIALLY OVER THE WRN PORTION OF SLIGHT RISK AREA. THIS WOULD SUGGEST THE POTENTIAL FOR SOME UPDRAFT ROTATION EARLY IN STORM LIFE CYCLES WITH A GRADUAL TRANSITION TO OUTFLOW DOMINANT MULTICELL CLUSTERS OR A BROKEN LINE. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL PRODUCTION WITH THE PRIMARY SEVERE WEATHER THREAT BEING DAMAGING WINDS. ...NRN/CNTRL NEW ENGLAND... CLUSTERS OF STRONG TO POTENTIALLY SEVERE STORMS CAPABLE OF LOCALLY DAMAGING WINDS MAY BE ONGOING AT THE ONSET OF THE FORECAST FROM NERN NY INTO NRN NEW ENGLAND IN ASSOCIATION WITH LOW-LEVEL WAA OCCURRING N OF SURFACE WARM FRONT. THIS ACTIVITY SHOULD SHIFT SEWD OR EWD THROUGH THE MORNING HOURS. HEIGHT RISES/INTENSIFYING CAP IN WAKE OF SURFACE WARM FRONTAL PASSAGE AND WITHIN SLIGHT RIDGING AHEAD OF QUEBEC SHORT WAVE TROUGH WILL LIKELY SUPPRESS ANY SEVERE CONVECTION THROUGH THE AFTERNOON HOURS...PERHAPS INTO EARLY EVENING. HOWEVER WITH TIME...HEIGHT FALLS ON SERN PERIPHERY OF QUEBEC SHORT WAVE TROUGH SHOULD SUPPORT AN INCREASE IN TSTM ACTIVITY OVER THE ST. LAWRENCE VALLEY WITH STORMS BECOMING INCREASINGLY LIKELY ACROSS NRN/CNTRL NEW ENGLAND TONIGHT. STRONG WLY DEEP SHEAR OF 40-50 KT INDICATES THE POTENTIAL FOR EMBEDDED BOWING STRUCTURES CAPABLE OF MAINLY DAMAGING WINDS. ..MEAD/GRAMS.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 12:57:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 08:57:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011257 SWODY1 SPC AC 011255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 AM CDT TUE AUG 01 2006 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER NERN NY AND NRN /CNTRL NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MO VLY TO THE UPR GRT LKS... ...SYNOPSIS... SUBTROPICAL UPR RIDGE WILL ELONGATE E TO THE MID ATLANTIC CST THIS PERIOD AS BELT OF STRONG WLY FLOW ASSOCIATED WITH NRN ONTARIO SHORTWAVE TROUGH OVERSPREADS CNTRL QUEBEC AND THE LWR ST LAWRENCE VLY. IN THE WEST...TROUGH OVER THE NRN GRT BASIN SHOULD CONTINUE ENE TO THE NRN PLNS WHILE A SERIES OF WEAKER IMPULSES MOVE NEWD IN BELT OF ENHANCED FLOW EXTENDING FROM THE SRN HI PLNS TO THE UPR MS VLY. SURFACE LOW ACCOMPANYING THE ONTARIO DISTURBANCE SHOULD TRACK E ACROSS QUEBEC...ALLOWING NW-SE ORIENTED WARM FRONT NOW IN WRN NEW ENGLAND TO REDEVELOP E INTO NRN AND CNTRL ME BY LATE IN THE DAY. FARTHER W...TRAILING COLD FRONT WITH WAVES EXPECTED TO DRIFT SLOWLY S/SE ACROSS THE CNTRL PLNS...THE MID/UPR MS VLY AND THE UPR GRT LKS. ...NE NY INTO NRN/CNTRL NEW ENGLAND... CLUSTERS OF TSTMS SHOULD CONTINUE TO FORM INVOF WARM FRONT OVER SW/S CNTRL QUEBEC TODAY...WHERE 30+ KT WARM/MOIST WLY LLJ WILL MOST STRONGLY IMPINGE ON BOUNDARY. MORE ISOLATED DEVELOPMENT MAY ALSO OCCUR SWD INTO NERN NY AND WRN/NRN NEW ENGLAND...WHERE HEIGHT RISES ASSOCIATED WITH ELONGATING RIDGE WILL TEND TO SUPPRESS DEVELOPMENT ...BUT SUBSTANTIAL DIFFERENTIAL HEATING WILL EXIST. THE AXIS OF DEVELOPMENT LIKELY WILL SHIFT E WITH TIME WITH MOTION OF FRONT. BY EARLY EVENING...COMBINATION OF DIURNAL HEATING AND LARGE SCALE ASCENT ON SRN FRINGE OF QUEBEC SHORTWAVE IMPULSE SHOULD SUPPORT INCREASED STORM DEVELOPMENT ALONG BOTH THE WARM FRONT...AND ALONG COLD FRONT SETTLING S OVER THE ST. LAWRENCE VLY. THIS ACTIVITY SHOULD CONTINUE E/ESE ACROSS NRN NEW ENGLAND TONIGHT/EARLY WEDNESDAY. GIVEN MODERATE TO STRONG /30-40 KT/ DEEP W TO NWLY CLOUD-LAYER FLOW...AND MODEST DIRECTIONAL SHEAR...EMBEDDED SUSTAINED STORMS/ SUPERCELLS APPEAR LIKELY. ASSOCIATED BOWING SEGMENTS COULD YIELD DAMAGING WIND AND POSSIBLY A TORNADO...IN ADDITION TO VERY HEAVY RAIN...AS PWS REMAIN AROUND 2 INCHES. ...MID MO VLY TO UPR GRT LKS... STORM OUTFLOW/LOW LEVEL DIVERGENCE ASSOCIATED WITH WEAK IMPULSE LIFTING NE ACROSS THE CNTRL PLNS LIKELY WILL MITIGATE SEVERE THREAT OVER PARTS OF NEB AND IA TODAY. HOWEVER...AIR MASS E OF OUTFLOW BOUNDARY/COLD FRONT SHOULD DESTABILIZE WITH DAYTIME HEATING. MLCAPE TO 2500 J/KG WILL BE POSSIBLE OVER KS...AND FROM ERN IA INTO CNTRL/SRN WI AND LWR MI. WHILE ELEVATED STORMS COULD POSE A LIMITED SEVERE THREAT LATER TODAY INTO TONIGHT INVOF FRONT OVER CNTRL/ERN NEB INTO ERN SD...GREATER CHANCE FOR SEVERE SHOULD ACCOMPANY MORE SURFACE-BASED ACTIVITY FROM ERN IA INTO WI/LWR MI. FORECAST SOUNDINGS INDICATE MODERATELY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL...WITH WEAK WINDS ABOVE 6-7 KM...ESPECIALLY OVER THE WRN PART OF SLIGHT RISK AREA. THIS SUGGESTS THE POTENTIAL FOR UPDRAFT ROTATION EARLY IN STORM LIFE CYCLES...BUT WITH A FAIRLY RAPID EVOLUTION TO OUTFLOW DOMINANT MULTICELL CLUSTERS/BROKEN LINES. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL POTENTIAL...WITH THE PRIMARY SEVERE THREAT BEING DAMAGING WIND. ...SERN U.S... WWD-MOVING UPR IMPULSE MAY ENHANCE POTENTIAL FOR A CLUSTER OR TWO OF DIURNAL PULSE STORMS WITH LOCALLY DAMAGING WIND IN MS/AL AND THE FL PANHANDLE REGION. ..CORFIDI/GRAMS.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 16:33:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 12:33:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011634 SWODY1 SPC AC 011633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1133 AM CDT TUE AUG 01 2006 VALID 011630Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NEB THROUGH UPR GRT LKS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NY THROUGH NRN / CNTRL NEW ENGLAND... ...SYNOPSIS... SUBTROPICAL UPR RIDGE WILL ELONGATE E TO THE MID ATLANTIC CST THIS PERIOD AS BELT OF STRONG WLY FLOW ASSOCIATED WITH SRN QUEBEC SHORTWAVE TROUGH OVERSPREADS LWR ST LAWRENCE VLY. IN THE WEST...TROUGH OVER THE NRN GRT BASIN SHOULD CONTINUE ENE TO THE NRN PLNS WHILE A SERIES OF WEAKER IMPULSES MOVE NEWD IN BELT OF ENHANCED FLOW EXTENDING FROM THE SRN HI PLNS TO THE UPR MS VLY. SURFACE LOW ACCOMPANYING THE ONTARIO DISTURBANCE SHOULD TRACK E ACROSS QUEBEC...ALLOWING NW-SE ORIENTED WARM FRONT NOW MOVING INTO MAINE. FARTHER W...TRAILING COLD FRONT EXPECTED TO DRIFT SLOWLY S/SE ACROSS THE CNTRL PLNS...THE MID/UPR MS VLY AND THE UPR GRT LKS. ...NE NY INTO NRN/CNTRL NEW ENGLAND... ONE CLUSTER OF STORMS ALREADY MOVING SE OUT OF QUEBEC INTO NRN VT/WRN ME...WITH ANOTHER CLUSTER MOVING SE THROUGH QUEBEC. WARM/MOIST SWLY LLJ PLUS LARGE SCALE LOW LEVEL ASCENT WILL RESULT IN CONTINUED THUNDERSTORM DEVELOPMENT THROUGH THE NIGHT. SEVERE THREAT MAY BE MITIGATED BY UPPER RIDGING AND WARM TEMPERATURES ALOFT ON THE WESTERN END OF THE SLIGHT RISK. BY EARLY EVENING...COMBINATION OF DIURNAL HEATING...LACK OF CONVECTIVE INHIBITION...AND LARGE SCALE ASCENT ON SRN FRINGE OF QUEBEC SHORTWAVE IMPULSE SHOULD SUPPORT INCREASED STORM DEVELOPMENT ALONG BOTH THE WARM FRONT...AND ALONG COLD FRONT SETTLING S OVER THE ST. LAWRENCE VLY. THIS ACTIVITY SHOULD CONTINUE E/ESE ACROSS NRN NEW ENGLAND TONIGHT/EARLY WEDNESDAY. GIVEN MODERATE TO STRONG /30-40 KT/ DEEP W TO NWLY CLOUD-LAYER FLOW...AND MODEST DIRECTIONAL SHEAR...EMBEDDED SUSTAINED STORMS/SUPERCELLS APPEAR LIKELY. ASSOCIATED BOWING SEGMENTS COULD YIELD DAMAGING WIND AND POSSIBLY A TORNADO...IN ADDITION TO VERY HEAVY RAIN...AS PWS REMAIN AROUND 2 INCHES. ...MID MO VLY TO UPR GRT LKS... STORM OUTFLOW/LOW LEVEL DIVERGENCE ASSOCIATED WITH WEAK IMPULSE LIFTING NE ACROSS THE CNTRL PLNS LIKELY WILL MITIGATE SEVERE THREAT OVER PARTS OF NEB AND IA TODAY. HOWEVER...AIR MASS E OF OUTFLOW BOUNDARY/COLD FRONT SHOULD DESTABILIZE WITH DAYTIME HEATING. MLCAPE TO 2500 J/KG WILL BE POSSIBLE OVER IA...AND FROM ERN IA INTO CNTRL/SRN WI AND LWR MI. WHILE ELEVATED STORMS COULD POSE A LIMITED SEVERE THREAT INVOF FRONT OVER ERN NEB INTO WRN IA...GREATER CHANCE FOR SEVERE IS POSSIBLE IN ERN IA THROUGH WI/LWR MI WHERE LACK OF CLOUD COVER RESULTS IN STRONGER AFTERNOON HEATING. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL POTENTIAL...WITH THE PRIMARY SEVERE THREAT BEING DAMAGING WIND. ...SERN U.S... WNWD-MOVING UPR IMPULSE OVER WRN AL MAY ENHANCE POTENTIAL FOR A CLUSTER OR TWO OF DIURNAL PULSE STORMS WITH LOCALLY DAMAGING WIND IN MS/AL AND THE FL PANHANDLE REGION. .,.GREAT BASIN... ISOLATED WIND DAMAGE POSSIBLE THIS AFTERNOON IN ASSOCIATION WITH UPPER TROUGH MOVING EWD. ..AFWA.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 19:38:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 15:38:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011929 SWODY1 SPC AC 011928 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0228 PM CDT TUE AUG 01 2006 VALID 012000Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS IN NEW YORK AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHWESTERN KANSAS/NEBRASKA INTO MICHIGAN... ...SYNOPSIS... UPPER TROUGH IN THE WESTERN CONUS AND SUBTROPICAL RIDGE CENTERED IN NORTH CAROLINA WILL REMAIN IN PLACE DURING THE FORECAST PERIOD. FRONTAL BOUNDARY ASSOCIATED WITH THE TROUGH EXTENDS FROM NORTHEASTERN KANSAS INTO SOUTHERN QUEBEC. THIS FRONT IS EXPECTED TO MOVE ONLY SLOWLY SOUTHEASTWARD INTO THIS EVENING. ...NEW YORK AND NEW ENGLAND... CONVECTIVE TEMPERATURES HAVE BEEN REACHED IN NEW YORK AND THUNDERSTORMS ARE BEGINNING TO DEVELOP. WITH DEWPOINTS IN THE MID AND UPPER 70S...MLCAPES ARE IN EXCESS OF 3000 J/KG DESPITE WARM MID LEVEL TEMPERATURES. NORTHWEST FLOW ON THE NRN PERIPHERY OF THE SUBTROPICAL RIDGE IS CONTRIBUTING TO DEEP LAYER SHEAR OF 25-35 KNOTS...WHICH WILL ALLOW FOR MULTICELLULAR THUNDERSTORM DEVELOPMENT. OTHER THUNDERSTORMS MAY ALSO FORM UPSTREAM IN ONTARIO/QUEBEC AND PROPAGATE SOUTHEASTWARD INTO THE AREA LATER THIS EVENING. GIVEN LOW LEVEL SHEAR AROUND 20 KNOTS AND DCAPE OVER 1000 J/KG...A DAMAGING WIND MCS IS POSSIBLE. HOWEVER...WARM MID LEVEL TEMPERATURES AND UPPER LEVEL RIDGING MAY TEND TO SUPPRESS WIDESPREAD THUNDERSTORM DEVELOPMENT. FURTHER NORTHEAST INTO NEW ENGLAND...CLOUD COVER IS HOLDING DOWN TEMPERATURES AND LIMITING INSTABILITY...ESPECIALLY INTO NORTHERN MAINE. THIS WILL TEND TO LIMIT THE SEVERE WEATHER THREAT. ...NORTHWESTERN KANSAS/NEBRASKA INTO MICHIGAN... SKIES HAVE CLEARED OUT OVER CENTRAL AND EASTERN NEBRASKA IN THE WAKE OF MORNING CONVECTION. RUC SOUNDINGS INDICATE MLCAPE AROUND 3000 J/KG WITH LITTLE MLCIN BY 2100 UTC. SCATTERED THUNDERSTORMS WILL DEVELOP AROUND THIS TIME AND SHOULD PRODUCE SOME DAMAGING WINDS GIVEN 30 KNOTS OF LOW LEVEL FLOW. WITH DEEP LAYER SHEAR AROUND 40 KNOTS...A FEW SUPERCELLS COULD FORM. MARGINALLY SEVERE HAIL IS POSSIBLE...BUT MID LEVEL LAPSE RATES ARE FAIRLY WEAK...AROUND 6.0 K/KM...SO WIND DAMAGE IS THE MAIN THREAT. FROM WISCONSIN INTO MICHIGAN THE DEEP LAYER SHEAR IS SOMEWHAT WEAKER AROUND 30 KNOTS...BUT LOW LEVEL FLOW OF 25 KNOTS IS STILL FAVORABLE FOR SOME DAMAGING WINDS. THUNDERSTORMS HAVE ALREADY DEVELOPED IN NORTHERN MICHIGAN AND THESE SHOULD INTENSIFY AND BECOME MORE WIDESPREAD ALONG THE FRONTAL BOUNDARY INTO THIS EVENING. ...UTAH/WYOMING/COLORADO... POTENT SHORTWAVE TROUGH CONTINUES TO FORCE THUNDERSTORMS IN WEAKLY UNSTABLE ENVIRONMENT. STRONG FLOW AROUND 30 KNOTS AT 600 MB WILL HELP ENHANCE AN ISOLATED DAMAGING WIND THREAT WITH ANY DOWNBURSTS THAT OCCUR IN STRONGER THUNDERSTORMS. ..AFWA.. 08/01/2006  From swody1 at goshenarc.org Wed Aug 2 00:58:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 20:58:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020058 SWODY1 SPC AC 020056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT TUE AUG 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM THE MID MO VALLEY INTO PARTS OF THE UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER HUDSON VALLEY INTO NRN/CNTRL NEW ENGLAND... ...MID MO VALLEY INTO THE UPPER GREAT LAKES... EVENING WATER VAPOR IMAGERY SHOWS PRIMARY SHORT WAVE TROUGH LIFTING NEWD THROUGH WY WITH SEVERAL WEAKER DOWNSTREAM IMPULSES...TWO OF WHICH APPEAR TO BE OVER NRN WI AND CNTRL NEB. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WAS LOCATED OVER CNTRL NEB WITH AN ATTENDANT FRONTAL BOUNDARY EXTENDING NEWD THROUGH SWRN MN/CNTRL WI INTO NRN LOWER MI. TRAILING PORTION OF THIS BOUNDARY THEN EXTENDED SWWD INTO WRN KS. AS OF 0015Z...MOST CONCENTRATED CLUSTERS OF STRONG/SEVERE STORMS EXIST OVER NERN NEB/NWRN IA AND NRN LAKE MI WITHIN ZONES OF STRONGER LARGE-SCALE FORCING ASSOCIATED WITH AFOREMENTIONED SHORT WAVE TROUGHS. 00Z OAX SOUNDING INDICATES THAT AMBIENT AIR MASS OVER THE MID MO VALLEY REMAINS MODERATELY UNSTABLE OWING TO MOIST BOUNDARY-LAYER CONDITIONS AND STEEP LOW-LEVEL LAPSE RATES WITH MLCAPES AROUND 2000 J/KG. FARTHER TO THE NE...MORE WIDESPREAD CLOUDS AND PRECIPITATION HAVE LIMITED DESTABILIZATION OVER SERN MN INTO NRN/CNTRL WI...THOUGH MLCAPES STILL REMAIN AROUND 1000 J/KG. INSTABILITY THEN INCREASES OVER LOWER MI OWING TO STRONGER DAYTIME HEATING WITH 00Z APX SOUNDING INDICATING MLCAPES OF AROUND 2000 J/KG. EXPECT GREATEST SEVERE THREAT TO CONTINUE THROUGH 03-05Z OVER PORTIONS OF NRN IA INTO SRN MN AND PARTS OF NRN LOWER MI WHERE AIR MASS REMAINS MOST UNSTABLE. 00Z OAX HODOGRAPH INDICATED MODEST LOW-LEVEL SHEAR WITH 0-1 KM SRH OF 150-200 M2/S2. HOWEVER...WIND FIELDS DECREASE SIGNIFICANTLY ABOVE 500 MB...SUGGESTING THAT STORMS SHOULD REMAIN OUTFLOW DOMINANT. WHILE A BRIEF TORNADO IS POSSIBLE WITH ANY ROTATING STORMS EARLY IN THEIR LIFE CYCLE... SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREATS. WIND PROFILES ARE MUCH MORE UNIDIRECTIONAL INTO THE UPPER GREAT LAKES WHICH SHOULD SUPPORT STORM FORWARD PROPAGATION WITH DAMAGING WINDS AND SOME HAIL BEING THE PRIMARY SEVERE THREATS. ...NEW ENGLAND... TSTMS CONTINUE TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING E OF WARM FRONT /NOW ALONG THE NH-ME BORDER/ OVER PORTIONS OF NWRN ME WITH A MORE ORGANIZED QUASI-LINEAR MCS OVER SRN QUEBEC MOVING 305/40-50 KTS. 00Z ALB SOUNDING INDICATES THAT AIR MASS STREAMING INTO WRN NEW ENGLAND IN WAKE OF WARM FRONT IS MODERATE TO STRONGLY UNSTABLE WITH MLCAPES OF 2000-3500 J/KG...WHICH SHOULD MAINTAIN SRN QUEBEC MCS SEWD THROUGH PORTIONS OF NRN/CNTRL NEW ENGLAND OVERNIGHT. VERTICAL SHEAR PROFILES ARE FORECAST TO REMAIN QUITE SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES WITH CORRIDORS OF DAMAGING WINDS APPEARING LIKELY IN ADDITION TO SOME LARGE HAIL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1696. ..MEAD.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 05:45:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 01:45:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020545 SWODY1 SPC AC 020543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT WED AUG 02 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS NEWD THROUGH THE GREAT LAKES AND INTO MUCH OF NEW ENGLAND... ...SYNOPSIS... QUASI-ZONAL FLOW REGIME WILL PERSIST OVER THE NRN TIER OF STATES DURING THE DAY ONE PERIOD WITH SEVERAL SHORT WAVE TROUGHS EMBEDDED WITHIN THIS PATTERN. ONE SUCH IMPULSE WILL TRANSLATE EWD FROM WI THROUGH THE U.P./NRN LOWER MI INTO SRN QUEBEC BY LATE TONIGHT. MEANWHILE...MID-LEVEL SHEAR AXIS OVER THE CNTRL/SRN HIGH PLAINS WILL SLOWLY SHIFT EWD ACROSS KS TODAY AND TONIGHT. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO GREAT LAKES IMPULSE WILL DEVELOP EWD FROM CNTRL WI TO ERN LAKE HURON ALONG BAROCLINIC ZONE EXTENDING EWD THROUGH NRN NEW ENGLAND. IN THE WAKE OF THIS LOW...TRAILING COLD FRONT WILL SLOWLY SAG SWD THROUGH THE MID/LOWER MO VALLEY TO SECONDARY LOW PRESSURE OVER CNTRL/ERN KS. ...GREAT LAKES REGION INTO NEW ENGLAND... CLUSTERS OF NOCTURNAL TSTMS ARE EXPECTED TO BE IN PROGRESS AT THE ONSET OF THE PERIOD FROM VICINITY OF SURFACE LOW EWD ALONG LOW-LEVEL WAA ZONE FROM ERN MN INTO THE U.P. AND PARTS OF LOWER MI. THIS ACTIVITY WILL LIKELY CONTINUE THROUGH THE DAY...MAINLY N OF FRONTAL ZONE WITH ADDITIONAL...MORE DIURNAL STORM DEVELOPMENT LIKELY BY AFTERNOON WITHIN DESTABILIZING AIR MASS TO THE S FROM PARTS OF SRN WI EWD ACROSS CNTRL/SRN LOWER MI. HERE...MOIST BOUNDARY LAYER CONDITIONS COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPES INCREASING TO 1500-2500 J/KG. LARGELY UNIDIRECTIONAL WIND PROFILES WITH 30-40 KTS OF DEEP SHEAR WILL BE SUPPORTIVE OF BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND SOME HAIL. FARTHER TO THE E OVER NEW ENGLAND...ADDITIONAL CLUSTERS OF STORMS WILL BE POSSIBLE TODAY AND TONIGHT...BOTH IN INTENSIFYING LOW-LEVEL WAA REGIME AHEAD OF SURFACE LOW...AS WELL AS WITH APPROACH OF SURFACE LOW LATE IN THE PERIOD. HERE TOO...KINEMATIC ENVIRONMENT IS CHARACTERIZED BY DEEP WLY TROPOSPHERIC FLOW WITH 35-45 KTS OF DEEP SHEAR...SUPPORTIVE OF ORGANIZED STORM STRUCTURES INCLUDING BOWS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. ...MIDWEST INTO KS... ADDITIONAL CLUSTERS OF STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON INTO EVENING ALONG COLD FRONT FROM NRN IL/SRN IA WWD INTO KS. STRONG DAYTIME HEATING AND RESULTANT STEEPING OF LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO THE DEVELOPMENT OF A MODERATELY UNSTABLE PRE-FRONTAL AIR MASS WITH MLCAPES OF 1000-2500 J/KG. FORCING WILL REMAIN RELATIVELY WEAK OVER THE MIDWEST...POTENTIALLY LIMITING STORM COVERAGE. HOWEVER FARTHER TO THE W OVER KS...FORCING FOR ASCENT ASSOCIATED WITH APPROACHING SHEAR AXIS WILL LIKELY SUPPORT MORE WIDESPREAD STORM COVERAGE. WHILE SLIGHTLY GREATER LOW-LEVEL HODOGRAPH CURVATURE IS FORECAST AHEAD OF SECONDARY SURFACE LOW ACROSS ERN KS INTO NWRN MO...DEEP-LAYER SHEAR WILL REMAIN QUITE MARGINAL /AOB 25-30 KTS/. THUS EXPECT THAT STORMS WILL REMAIN LARGELY MULTICELLULAR WITH THE PRIMARY THREATS BEING DAMAGING WINDS AND PERHAPS SOME HAIL. ..MEAD/JEWELL.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 12:57:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 08:57:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021257 SWODY1 SPC AC 021256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED AUG 02 2006 VALID 021300Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLNS THROUGH THE MID MS VLY/GRT LKS TO NRN NEW ENGLAND... ...SYNOPSIS... SEASONABLY STRONG ZONAL FLOW WILL PREVAIL OVER THE NRN THIRD OF THE NATION AS SEVERAL SHORT WAVE IMPULSES TEMPORARILY FLATTEN WRN FLANK OF BERMUDA RIDGE. ONE OF THESE DISTURBANCES...NOW OVER WI...WILL MOVE E ACROSS NRN MI INTO SRN QUEBEC BY LATE TONIGHT. FARTHER SE...MID-LEVEL SHEAR AXIS OVER THE CNTRL/SRN HIGH PLAINS EXPECTED TO SHIFT SLOWLY E ACROSS KS THROUGH TONIGHT. SURFACE LOW ACCOMPANYING GRT LKS IMPULSE WILL TRACK E ACROSS NRN MI AND SRN ONTARIO LATER TODAY/TONIGHT AS TRAILING COLD FRONT SETTLES SLOWLY SE ACROSS THE MID MS VLY AND CNTRL PLNS. E OF THE LOW...A FRONT SHOULD REMAIN MORE OR LESS STATIONARY EWD INTO NRN NEW ENGLAND. ...UPR GRT LKS TO NRN NEW ENGLAND... SEVERAL CLUSTERS OF STORMS EXPECTED TO MOVE/DEVELOP E ALONG STALLED FRONTAL ZONE FROM WI/NRN MI E ACROSS SRN ONTARIO/UPSTATE NY INTO NRN ENGLAND TODAY THROUGH TONIGHT. MUCH OF THE ACTIVITY MAY REMAIN SLIGHTLY ELEVATED ALONG AND N OF FRONT. BUT SURFACE HEATING SHOULD SUPPORT SURFACE-BASED STORM DEVELOPMENT FROM SRN/CNTRL WI E ACROSS CNTRL/SRN LOWER MI...AND POSSIBLY OVER UPSTATE NY/NWRN NEW ENGLAND BY EARLY AFTERNOON. RICH BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE LOW 70S/ WILL COMPENSATE FOR RELATIVELY WARM MID LEVEL TEMPERATURES TO YIELD MLCAPE OF 1500-2500 J/KG. COUPLED WITH DEEP...MODERATE TO STRONG /40+ KT/ UNIDIRECTIONAL CLOUD LAYER FLOW...SETUP SHOULD PROMOTE N/S BOWING SEGMENTS AND POSSIBLE EMBEDDED SUPERCELLS WITH DAMAGING WIND/MARGINALLY SEVERE HAIL. DEPENDING ON STORM-SCALE EVOLUTION ...FAIRLY CONCENTRATED WIND DAMAGE MAY AFFECT LWR MI AND PARTS OF WI/NRN IL TODAY. FARTHER E...A FINAL ROUND OF STORMS MAY AFFECT UPSTATE NY/NW NEW ENGLAND EARLY THURSDAY AS LLJ STRENGTHENS DOWNSTREAM FROM APPROACHING SURFACE WAVE. ...CNTRL PLNS TO MID MS VLY... SURFACE HEATING EXPECTED TO SUPPORT DEVELOPMENT OF ADDITIONAL STRONG TO SEVERE STORM CLUSTERS ALONG COLD FRONT/LEE TROUGH FROM THE TX/OK PANHANDLE REGION THROUGH PARTS OF KS AND NW MO INTO SRN IA/NRN IL. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPE OF 1500-2500 J/KG. FORCING FOR ASCENT...WHILE WEAKER THAN OVER THE GRT LKS...WILL BE ENHANCED BY SMALL SCALE DISTURBANCES WITHIN UPR LEVEL SHEAR AXIS. DEEP WIND PROFILES OVER REGION WILL BE LESS UNIDIRECTIONAL THAN OVER THE GREAT LKS/NORTHEAST...BUT OVERALL MAGNITUDES WILL BE RELATIVELY WEAK /AOB 25-30 KTS/. COUPLED WITH FAIRLY LARGE TEMPERATURE-DEWPOINT SPREADS AND LARGELY LINEAR FORCING FOR ASCENT...STORMS SHOULD FAIRLY QUICKLY ORGANIZE INTO BANDS/CLUSTERS. THE MAIN SEVERE THREAT SHOULD BE DAMAGING WIND...AND POSSIBLY MARGINALLY SEVERE HAIL. ..CORFIDI.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 16:20:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 12:20:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021620 SWODY1 SPC AC 021618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CDT WED AUG 02 2006 VALID 021630Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS THRU THE MIDDLE MS VALLEY AND GREAT LAKES TO NEW ENGLAND... ...SYNOPSIS... WESTERLIES NOW PREVAIL FROM COAST TO COAST ACROSS NRN TIER OF CONUS WITH BROAD HIGH PRESSURE DOMINATING MUCH OF SRN U.S. BAND OF 40-50KT MID LEVEL WESTERLIES IN ADVANCE OF S/WV TROUGH NOW MOVING ACROSS NRN CENTRAL U.S. WILL TRANSLATE EWD ACROSS GREAT LAKES THIS AFTERNOON AND NERN U.S. TONIGHT. COLD FRONT FROM UPR MI EXTENDS SWWD THRU SERN NEB TO NERN NM. FRONT WILL CONTINUE EWD ACROSS GREAT LAKES AND BY LATER TONIGHT REACH FROM NRN NY BACK TO VICINITY OK/KS BORDER. WARM...MOIST AND POTENTIALLY VERY UNSTABLE AIR REMAINS S AND E OF FRONTAL ZONE PARTICULARLY MS VALLEY EWD. ...GREAT LAKES TO NERN U.S... STRONG HEATING MOST AREAS TO S OF COLD FRONT WHERE DEWPOINTS GENERALLY 70F OR GREATER WILL GENERATE A VERY UNSTABLE AIR MASS WITH MLCAPES RANGING UPWARDS TO 2500 J/KG MANY AREAS. PRIMARY FOCUS FOR SEVERE THUNDERSTORM INITIATION THIS AFTERNOON WILL BE THE FRONTAL CONVERGENCE. BY MID AFTERNOON SEVERE THUNDERSTORMS EXPECTED TO BE INCREASING IN NUMBER AND INTENSITY FROM WI EWD ACROSS LOWER MI THRU UPSTATE NY AND WRN NEW ENGLAND. WITH 30-40KT OF DEEP LAYER SHEAR...STORMS SHOULD EVOLVE INTO SHORT LINES/BOW IN THE STRONG FLOW WITH ACCOMPANYING WIND DAMAGE POTENTIAL. LARGE HAIL THREAT WILL BE SOMEWHAT MITIGATED BY THE WARM LAPSE RATES. SUFFICIENT SHEAR GIVEN LARGE AMOUNT OF INSTABILITY FOR SUPERCELL POTENTIAL. THIS WOULD RESULT IN AN ENHANCED SEVERE THREAT ALONG WITH ISOLATED TORNADOES. ONE OF MORE FORWARD PROPAGATING MCS'S LIKELY DEVELOPING THIS EVENING WHICH ALSO WOULD INCREASE WIND DAMAGE THREAT. ...MID MS VALLEY SWWD TO CENTRAL/SRN HIGH PLAINS... DEEP LAYER SHEAR WILL RANGE DOWNWARD ALONG FRONTAL ZONE FROM 25-30KT IA AREA TO LESS THAN 20KT HIGH PLAINS. HOWEVER THE STRONG HEATING WILL DEVELOP STEEP LOW/MID LAPSE RATES AHEAD OF FRONT ALONG WITH MLCAPES CLIMBING TO AS HIGH AS 2000 J/KG. THUNDERSTORMS WILL ALSO DEVELOP IN RESPONSE TO FRONTAL CONVERGENCE BY MID/LATE AFTERNOON. CONVECTIVE MODE SHOULD BE MORE MULTI-CELLULAR WITH ISOLATED SUPERCELLS POSSIBLE. DAMAGING WINDS AND LARGE HAIL WOULD BE LIKELY...PARTICULARLY IN KS PORTION WHERE CAPE/SHEAR COMBINATION APPEARS TO BE MORE FAVORABLE. ..HALES/CROSBIE.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 20:05:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 16:05:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 022005 SWODY1 SPC AC 022003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT WED AUG 02 2006 VALID 022000Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NERN U.S. AND GREAT LAKES INTO THE CENTRAL PLAINS.... ...SYNOPSIS... LATEST SFC MESOANALYSIS SHOWS COLD FRONTAL BOUNDARY THAT EXTENDS FROM SWRN QUEBEC SWWD THRU SERN ONTARIO TO A LOW OVER EXTREME ERN UPR MI/NRN LWR MI. A FRONTAL BOUNDARY CONTINUES FROM THE LOW THRU CENTRAL WI. THESE BOUNDARIES ARE AHEAD OF POSITIVELY TILTED MID/UPR LEVEL SHORTWAVE TROUGH THAT EXTENDS FROM NERN MN SWWD INTO NERN NEB. THIS TROUGH IS EXPECTED TO CONTINUE EWD INTO WI/IA BY 03/12Z. ...PARTS OF THE NORTHEAST FROM CENTRAL NEW ENGLAND INTO NEW YORK STATE... AIR MASS IS ABNORMALLY HOT AND MOIST WITH TEMPERATURES GENERALLY IN THE 90S AND DEW POINTS IN THE MID/UPR 70S FROM NEW YORK INTO SRN ME AND COASTAL MA. NUMEROUS STRONG/SEVERE STORMS ARE TRACKING EWD ACROSS PARTS OF VT/NH AND CENTRAL NY STATE. MLCAPE VALUES ARE 2000-2500 J/KG FROM ERN LE REGION THRU SRN NEW ENGLAND. RUC MODEL SOUNDINGS SHOW THAT LAPSE RATES ARE BETWEEN 6.0 AND 6.5C/KM...BUT THE DATA ALSO SHOWS A FAIR AMOUNT OF DRYING ABOVE 720 MB WHICH WOULD INDICATE THAT THE MAIN THREAT WILL BE DAMAGING WINDS AND HAIL. ...GREAT LAKES REGION... COLD FRONT EXTENDS FROM EXTREME N CENTRAL LOWER MI SWWD THRU GRB AND RST AND WILL CONTINUE SEWD AND SWD ACROSS THESE REGIONS. STORMS ARE DEVELOPING/RAPIDLY INTENSIFYING WITHIN STRONG INSTABILITY GRADIENT WHERE MLCAPE RANGES FROM 1000-3000 J/KG. RUC MODEL SOUNDING AT OSH SHOWS MID LEVEL DRY AIR PRESENT WITH MID LEVEL LAPSE RATES NEAR 7C/KM. THIS WOULD INDICATE AGAIN THE THREAT FOR DAMAGING WINDS...BUT SOME LARGE HAIL MAY OCCUR WITH THE STEEP MID LEVEL LAPSE RATES THRU THIS AFTERNOON. ...IA SWWD INTO KS... WARM AIR MASS WITH DEW POINTS MAINLY FROM THE MID 60S TO LOWER 70S IS PRESENT THRU THIS AREA. WEAK FRONT/SURFACE TROUGH EXTENDS FROM NERN IA INTO SWRN KS. LOOKS LIKE MAINLY MID LEVEL BASED TYPE THUNDERSTORMS WILL DEVELOP ALONG THE SURFACE TROUGH AS EFFECTIVE CAPE VALUES ARE RANGING BETWEEN 1500-2000 J/KG. THIS ENVIRONMENT IS FAVORABLE FOR DOWNBURST WINDS WITH STEEP LAPSE RATES IN THE LOWEST 3KM OF 8.5C/KM. ..MCCARTHY.. 08/02/2006  From swody1 at goshenarc.org Thu Aug 3 00:54:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 20:54:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030054 SWODY1 SPC AC 030053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT WED AUG 02 2006 VALID 030100Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE GREAT LAKES/MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF UPSTATE NY AND WRN NEW ENGLAND... ...SYNOPSIS... EXTENSIVE FRONTAL ZONE LIES ALONG THE NWRN/NRN PERIPHERY OF DEEP LAYER SUBTROPICAL RIDGE FROM THE SRN HIGH PLAINS...NEWD ACROSS THE UPPER MIDWEST...AND THEN EWD FROM SRN ONTARIO TO NRN NEW ENGLAND. PACKETS OF STRONGER MID LEVEL FLOW...ASSOCIATED WITH IMPULSES EMBEDDED WITHIN THE WLYS...WERE AIDING SURFACE CONVERGENCE/LIFT AND TSTM DEVELOPMENT ALONG SEGMENTS OF THE FRONT FROM KS TO MI TO SRN ONTARIO. GREATEST POTENTIAL FOR STORM ORGANIZATION AND PERSISTENCE OVERNIGHT WILL OCCUR OVER THREE REGIONS. FROM WEST-TO-EAST THESE REGIONS ARE...THE MO RIVER VALLEY...IL/MI... AND UPSTATE NY/WRN NEW ENGLAND. ...KS/MO/EXTREME SERN NEB AND SRN IA... WELL ORGANIZED MESOSCALE STORM COMPLEX ACROSS KS HAS PRODUCED A LARGE COLD POOL. RESULTANT OUTFLOW SHOULD CONTINUE TO SPAWN SCATTERED TSTM DEVELOPMENT WITH SOME THREAT FOR DAMAGING DOWNBURSTS IN HOT/WELL-MIXED AND MODERATELY UNSTABLE AIR MASS FROM ERN KS EWD INTO MO. GREATER POTENTIAL FOR PERSISTENT MESOSCALE ORGANIZATION... AND PERHAPS A MORE CONCENTRATED SEVERE THREAT...MAY EVOLVE FROM FRONTAL WAVE MOVING ACROSS EXTREME NEB AND INTO VERY MOIST AND UNSTABLE AIR MASS ALONG THE FRONT FROM SRN IA/NRN MO TO THE MS RIVER THROUGH LATE TONIGHT. ...IL/MI... SEVERAL BANDS OF DEEP CONVECTION PRECEDE THE SURFACE FRONT SITUATED FROM SRN WI ENEWD ACROSS LOWER MI THIS EVENING. MOST INTENSE STORMS WERE NOW DEVELOPING INTO AN AXIS OF LOCALLY EXTREME INSTABILITY FROM CHICAGO ACROSS SRN LAKE MI...AND INTO SWRN MI. SOMEWHAT LIMITED DEEP SHEAR EXIST OVER THIS REGION BASED ON LATEST SOUNDINGS FROM ILX AND DTX. HOWEVER...LARGE SCALE LIFT AND DEGREE OF INSTABILITY WILL LIKELY PROVE SUFFICIENT TO MAINTAIN A THREAT DAMAGING WINDS AS CONVECTION PERSISTS AND DEVELOPS GRADUALLY EWD THROUGH LATE TONIGHT. ...NY/VT... PER COORDINATION WITH ENVIRONMENT CANADA AND REVIEW OF OBSERVATIONAL DATA FROM SRN/SWRN ONTARIO...WIDESPREAD SEVERE WIND WAS ACCOMPANYING STORMS NORTH OF LAKES ERIE AND ONTARIO THIS EVENING. THIS LINEAR MCS WAS BEING DRIVEN BY A WELL-DEFINED SHORT WAVE TROUGH...STRONG LOW LEVEL WARM AIR ADVECTION...AND VERY UNSTABLE BOUNDARY LAYER AIR MASS FEEDING INTO THE REGION FROM THE MIDWEST. STRONG DYNAMIC FORCING ASSOCIATED WITH FRONTAL WAVE AND WARM AIR/MOISTURE ADVECTION WITH THIS SYSTEM WILL MOVE ACROSS THE LAKES AND INTO NY AND PARTS OF NEW ENGLAND THROUGH LATE TONIGHT. EVENING SOUNDINGS FROM BUF AND ALY DEPICTED RELATIVELY STEEP LOW LEVEL LAPSE RATES AND ABUNDANT MOISTURE WITH MORE THAN ADEQUATE SHEAR TO SUSTAIN SEVERE STORMS. OVERALL PATTERN APPEARS TO FAVOR THE MAINTENANCE OF A SEVERE MCS WITH POTENTIAL FOR NUMEROUS DAMAGING WIND EVENTS MOVING ACROSS UPSTATE NY AND PARTS OF VT INTO LATE TONIGHT/EARLY THURSDAY. ..CARBIN.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 04:55:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 00:55:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030455 SWODY1 SPC AC 030453 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1153 PM CDT WED AUG 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST/OH VALLEY TO SRN NEW ENGLAND... ...SYNOPSIS... SUBTROPICAL RIDGE AXIS WILL CONTINUE TO PRODUCE TYPICALLY HOT AND HUMID SUMMERTIME CONDITIONS FROM THE SRN ROCKIES AND PLAINS EWD/NEWD ACROSS MUCH OF THE MS VALLEY...SOUTH...AND MOST OF THE EAST COAST TODAY. A RESPITE FROM THE HEAT WILL COME ALONG WITH THE CHANCE FOR ISOLATED TO SCATTERED SEVERE STORMS DURING THE AFTERNOON AND EVENING FROM PARTS OF THE SRN ROCKIES/PLAINS EAST TO THE MIDWEST/OH VALLEY AREAS...AND OVER PA/NY/NJ...AND PORTIONS OF SRN NEW ENGLAND. ADDITIONAL SCATTERED AFTERNOON AND EARLY EVENING PULSE/MULTICELL STORMS COULD PRODUCE ISOLATED DAMAGING WIND GUSTS AND HAIL FROM THE SRN APPALACHIANS TO THE NERN GULF COAST AND FL. ...MIDWEST TO SRN NEW ENGLAND... DEEP-LAYER FRONTAL ZONE REINFORCED BY SEVERAL ONGOING CONVECTIVE COMPLEXES WILL REMAIN SITUATED ALONG THE SRN EDGE OF FASTER MID LEVEL FLOW OF 30-40KT FROM THE MID MS VALLEY EWD TO NY/CT. VERY UNSTABLE CONDITIONS SHOULD DEVELOP WITH HEATING OF THE DAY ALONG AND SOUTH OF THE FRONT WITH MLCAPE OVER 2000 J/KG LIKELY. LARGE SCALE FORCING ASSOCIATED WITH MID LEVEL HEIGHT FALLS AND FRONTAL LIFT WILL SPUR ADDITIONAL CONVECTION WITH STORMS INTENSIFYING AS GREATER INSTABILITY IS REALIZED. ACTIVITY SHOULD FORM INTO SEVERAL PERSISTENT ESEWD-MOVING BANDS OR CLUSTERS WITH WIND DAMAGE BEING THE PREDOMINANT SEVERE WEATHER HAZARD. ...SRN ROCKIES/PLAINS... FARTHER WEST...LARGE SCALE FORCING AND SHEAR WILL BE WEAKER. HOWEVER...TRAILING FRONT AND STRONG HEATING WILL PROVIDE SOME IMPETUS FOR AT LEAST ISOLATED STRONG TO SEVERE STORM DEVELOPMENT FROM THE OZARKS WSWWD ACROSS OK/NRN TX AND NM BY AFTERNOON. WELL MIXED BOUNDARY LAYER AND LARGE SURFACE TEMP/DEWPOINT DEPRESSIONS WILL LEAD TO THE POTENTIAL FOR DAMAGING DOWNBURST WINDS FROM PULSE STORMS DURING THE LATE AFTERNOON. A WEAK IMPULSE ROTATING AROUND THE WRN/NWRN PERIPHERY OF SUB-TROPICAL RIDGE...COUPLED WITH WEAK LOW LEVEL UPSLOPE FLOW AND DIFFERENTIAL HEATING...MAY PROMOTE A FEW TSTM CLUSTERS FROM NERN NM NWD/NEWD ALONG THE FRONT RANGE AND INTO THE CENTRAL HIGH PLAINS. SOME OF THIS CONVECTION MAY PERSIST PAST SUNSET AS LOW LEVEL JET INTENSIFIES AND SUSTAINS MASS TRANSPORT INTO THE CENTRAL HIGH PLAINS AREA. GENERALLY LIMITED MOISTURE AND WEAK FORCING SHOULD KEEP SEVERE WEATHER ISOLATED TO MARGINAL HAIL...AND PERHAPS A COUPLE OF SEVERE WIND GUSTS. ANOTHER DISTURBANCE OF SUB-TROPICAL ORIGIN IS FORECAST TO SPREAD NWWD FROM NRN MEXICO TO NEAR THE AZ/NM BORDER AREA. THIS SYSTEM COULD ENHANCE TSTM COVERAGE AND PERSISTENCE FROM WEST TX WWD TO SERN AZ WITH ISOLATED STRONG TO SEVERE WIND GUSTS AND HAIL POSSIBLE...ALONG WITH HEAVY RAIN. ...SOUTHEAST/FL... STRONG HEATING AND WEAK CAP WILL CONTRIBUTE TO THE DEVELOPMENT OF AFTERNOON STORMS ACROSS THE SOUTHEAST AND FL. STORMS ACROSS THE SOUTHEAST WILL LIKELY FORM ON THE ERN SLOPES OF THE APPALACHIANS AND ALSO NEAR SEA BREEZE BOUNDARIES NEAR THE COAST. WEAK SHEAR AND FORCING WITHIN DEEP-LAYER ANTICYCLONE WILL CONFINE SEVERE WEATHER POTENTIAL TO ISOLATED/RANDOM PULSE STORMS ACCOMPANIED BY STRONG WIND GUSTS. SLIGHTLY GREATER CONCENTRATION OF STORMS WITH WIND AND HAIL POTENTIAL MAY FORM ACROSS PORTIONS OF FL AS A MID LEVEL IMPULSE AND ASSOCIATED MID LEVEL COLD POOL DRIFT WWD COINCIDENT WITH STRONGEST DIURNAL DESTABILIZATION. ..CARBIN/JEWELL.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 13:01:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 09:01:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031301 SWODY1 SPC AC 031259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0759 AM CDT THU AUG 03 2006 VALID 031300Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR OH VLY INTO SRN NEW ENGLAND... ...SYNOPSIS... LOW AMPLITUDE SHORTWAVE TROUGH NOW OVER THE MID/UPR MS VLY WILL TRACK E TO LK HURON BY THIS EVENING BEFORE CONTINUING E INTO UPSTATE NY FRIDAY MORNING. MODERATE TO STRONG ZONAL FLOW ASSOCIATED WITH THIS FEATURE WILL PREVAIL FROM THE N CNTRL STATES TO THE N AND MID ATLANTIC CST. ELSEWHERE...REMNANT DEFORMATION AXIS WITH EMBEDDED DISTURBANCES EXPECTED TO PERSIST FROM THE SRN HI PLNS E/NE INTO SRN KS AND MO. FARTHER S...SUBTROPICAL IMPULSES SHOULD CONTINUE SLOWLY W ACROSS THE BAHAMAS/FL...AND ACROSS S TX. AT THE SURFACE...DIFFUSE W/E COLD FRONT LOCALLY REINFORCED BY CONVECTIVE OUTFLOW WILL SETTLE S ACROSS THE ERN GRT LKS AND OH VLY. A SHALLOW COOL SURGE WILL ALSO MOVE SW INTO CNTRL NEW ENGLAND. ...OH VLY INTO SRN NEW ENGLAND... DEEP UNIDIRECTIONAL WSWLY FLOW...WITH MEAN SPEEDS ON THE ORDER OF 40 KTS...WILL PREVAIL DOWNSTREAM FROM SHORTWAVE IMPULSE CROSSING THE GRT LKS. SURFACE HEATING SHOULD YIELD VERY UNSTABLE CONDITIONS ALONG/AHEAD OF COLD FRONT/OUTFLOW BOUNDARIES...WITH AVERAGE MLCAPE AOA 2000 J/KG LIKELY FROM PARTS OF IN/KY E/NE INTO SRN NEW ENGLAND AND PA/SRN NY. COMBINATION OF LARGE SCALE FORCING...FRONTAL UPLIFT AND DEEP UNIDIRECTIONAL FLOW SHOULD SUPPORT ADDITIONAL ROUNDS OF FORWARD-PROPAGATING CONVECTIVE SYSTEMS...WITH N/S-ORIENTED EMBEDDED BOWS PRODUCING WIND DAMAGE AND POSSIBLY MARGINALLY SEVERE HAIL THROUGH EARLY TONIGHT. ...SRN/CNTRL PLNS INTO THE RCKYS/SW... WEAK DEEP SHEAR/FORCING WILL PREVAIL INVOF STALLING COLD FRONT/LEE TROUGH OVER THE SRN PLNS. STRONG HEATING...SHALLOW FRONTAL CONVERGENCE AND UPSLOPE COMPONENTS WILL...HOWEVER...PROVIDE SUPPORT FOR ISOLATED TO WIDELY SCATTERED STRONG TO SEVERE PULSE STORMS FROM THE OZARKS WSW ACROSS OK/NRN TX AND ERN NM BY AFTERNOON. DEEPLY MIXED BOUNDARY LAYER WITH LARGE SURFACE TEMP/DEWPOINT SPREADS MAY PROMOTE A FEW MICROBURSTS THIS AFTERNOON AND EARLY EVENING. FARTHER W...WEAK IMPULSE MOVING W ACROSS S TX...COUPLED WITH WEAK UPSLOPE FLOW AND DIFFERENTIAL HEATING...MAY SUPPORT A FEW PERSISTENT TSTM CLUSTERS FROM NERN NM NWD/NEWD ALONG THE FRONT RANGE AND INTO THE CENTRAL HIGH PLAINS. SOME OF THIS ACTIVITY CONVECTION MAY PERSIST PAST SUNSET AND SPREAD INTO SD/SRN ND LATE TONIGHT AS LLJ INTENSIFIES. SUFFICIENT INSTABILITY MAY DEVELOP TO SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL AND WIND. ANOTHER DISTURBANCE OF SUB-TROPICAL ORIGIN WILL MOVE NW FROM NRN MEXICO TO NEAR THE AZ/NM BORDER AREA. THIS SYSTEM COULD ENHANCE TSTM COVERAGE/PERSISTENCE FROM W TX INTO SE AZ...WITH ISOLATED STRONG TO SEVERE WIND GUSTS AND HAIL POSSIBLE...ALONG WITH HEAVY RAIN. ...FL PENINSULA... WWD-MOVING UPR DISTURBANCE WILL STEEPEN MID LEVEL LAPSE RATES AND ENHANCE LARGE SCALE ASCENT ACROSS FL PENINSULA DURING MAX HEATING TODAY. THIS MAY SUPPORT STRONGER/MORE PERSISTENT AND ORGANIZED DIURNAL STORM CLUSTERS RELATIVE TO RECENT DAYS. PARTS OF THE SRN/CNTRL PENINSULA MAY REQUIRE UPGRADE TO SLIGHT RISK IF STORM SCALE INTERACTIONS ARE ABLE TO TAKE ADVANTAGE OF INCREASING INSTABILITY. ..CORFIDI/JEWELL.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 16:34:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 12:34:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031633 SWODY1 SPC AC 031632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT THU AUG 03 2006 VALID 031630Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OHIO VALLEY TO SRN NEW ENGLAND... ...SYNOPSIS... ZONAL FLOW CONTINUES ACROSS NRN CONUS WITH A BROAD UPPER RIDGE S OF 40N. PRIMARY FRONTAL ZONE CONTINUES TO MOVE SLOWLY S AND E AND THIS MORNING EXTENDS FROM SWRN ONTARIO THRU NRN IL AND THEN SWWD ACROSS NRN OK INTO TX PANHANDLE. A VERY WARM AND MOIST AIR MASS REMAINS TO S OF FRONTAL ZONE FROM SRN NEW ENGLAND TO SRN PLAINS. FOCUS FOR INITIATION OF STRONG/SEVERE THUNDERSTORMS WILL BE PRIMARILY VICINITY THE SRN FRINGE OF THICKER BAND OF CLOUDS THAT EXTENDS FROM SRN NEW ENGLAND ACROSS NY INTO NRN OH VALLEY. ...OH VALLEY TO SRN NEW ENGLAND... AS TEMPERATURES RISE THRU THE 90S WITH DEWPOINTS AOA 70F...AIR MASS IS BECOMING VERY UNSTABLE WITH MLCAPES INCREASING TO 2000-3000 J/KG. 30-35 KT OF SHEAR COMMON AHEAD OF WEAK TROUGH NOW MOVING EWD THRU THE GREAT LAKES. CLUSTERS OF THUNDERSTORMS HAVE ALREADY DEVELOPED NERN OH AND CENTRAL IND THIS AM. WITH THE STRONG HEATING...STRONG/SEVERE THUNDERSTORMS WILL BE INCREASING EWD ACROSS OH VALLEY INTO SRN NEW ENGLAND THRU THE AFTERNOON. WIND DAMAGE WILL BE GREATEST CONCERN PARTICULARLY ASSOCIATED WITH DEVELOPMENT OF SHORT LINES/BOWS GIVEN THE FAVORABLE SHEAR...STEEP LOW LEVEL LAPSE RATES AND HIGH PW/S. HAIL WILL BE LESS LIKELY WITH THE WARM MID LEVEL LAPSE RATES. ...CAROLINAS... WITH VERY STRONG HEATING...AND HIGH SURFACE DEWPOINTS....CONDITIONS ARE FAVORABLE FOR STRONG/ISOLATED SEVERE STORMS TO DEVELOP E OF APPALACHIANS THIS AFTERNOON AND EVENING. WHILE SHEAR IS WEAK...DCAPES FORECASTED TO BE IN EXCESS OF 1500 J/KG AND STEEP LOW LEVEL LAPSE RATES SUPPORT POTENTIAL FOR PULSE SEVERE IN FORM OF DOWNBURSTS FROM MID AFTERNOON UNTIL SUNSET. ...SRN FL... WEAK MID/UPPER LEVEL CYCLONIC SYSTEM OFF E COAST OF FL WILL PROVIDE BOTH SOME INCREASE IN SHEAR AND LAPSE RATES TO ENHANCE THE DIURNAL THUNDERSTORM CYCLE. ISOLATED DOWNBURSTS AND MARGINAL HAIL WILL BE POSSIBLE WITH STRONGEST STORMS S HALF OF FL. ...SRN ROCKIES/CENTRAL SRN HIGH PLAINS EWD ACROSS OK INTO SRN MO... BOUNDARIES HAVE MOVED SWD TO STRETCH ACROSS SRN MO INTO SWRN OK THEN WWD. EXAMINING 12Z SOUNDINGS...THE MODERATELY UNSTABLE AIR MASS WILL SUPPORT THUNDERSTORMS DEVELOPING BY MID/LATE AFTERNOON VICINITY BOUNDARIES AS MLCAPES CLIMB TO ABOVE 2000 J/KG AND DCAPES ALSO INCREASE TO AOA 1500 J/KG. WITH WEAK DEEP LAYER SHEAR...STORM MODE SHOULD BE PRIMARILY PULSE SRN PLAINS AND POSSIBLY MULTICELL ERN CO INTO WRN NEB/SD WHERE SHEAR IS A LITTLE GREATER. DOWNBURSTS AND ISOLATED HAIL WILL BE POSSIBLE MUCH OF THIS AREA BUT LACK OF ORGANIZATION PRECLUDES A RISK AREA. ..HALES/CROSBIE.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 20:04:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 16:04:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032003 SWODY1 SPC AC 032001 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0301 PM CDT THU AUG 03 2006 VALID 032000Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE NORTHEAST INTO THE LOWER OHIO VALLEY.... ...SYNOPSIS... MID/UPPER LEVEL SHORTWAVE TROUGH IS MOVING EWD INTO THE ERN GREAT LAKES AND EXTENDING SWWD INTO THE MID MS VALLEY. LATEST SURFACE ANALYSIS SHOWS A COLD FRONT FROM WRN LAKE ERIE WSWWD THRU CENTRAL MO INTO SERN KS...WITH SEVERAL CONVECTIVE BOUNDARIES ACROSS NE INTO CENTRAL OHIO...THRU CENTRAL NY STATE INTO NERN OH...AND FROM NERN PA ENEWD THRU COASTAL MA. THE BOUNDARIES WILL REMAIN THE FOCUS FOR FURTHER CONVECTION THRU EARLY TONIGHT. ...INDIANA/OHIO ENEWD INTO SRN NEW ENGLAND... STRONG/SEVERE THUNDERSTORMS EXTENDS ALONG THE BOUNDARY FROM S CENTRAL NY STATE THRU NRN/CENTRAL OH AND CENTRAL INDIANA. ALONG AND S OF THE BOUNDARY...AIR MASS IS MODERATELY UNSTABLE WITH MLCAPE BETWEEN 1500-2500 J/KG DUE TO DAYTIME HEATING AND SURFACE DEW POINTS IN THE UPR 60S TO LOW 70S. MAIN THREAT WITH ALL THIS ACTIVITY WILL BE DAMAGING WINDS RAIN-COOLED AIR BEHIND THE LINES OF CONVECTION ACCELERATE THE STORMS EWD INTO UNSTABLE AIR. IN ADDITION...ISOLATED STRONG STORMS ARE DEVELOPING OVER SERN LOWER MI INTO E CENTRAL IL AHEAD OF 850 MB FRONT AND JUST BEHIND SURFACE FRONT. THESE STORMS ARE EXPECTED TO BECOME STRONG THRU EARLY TONIGHT AND POSSIBLY PRODUCE SOME STRONG GUSTY WINDS. ...SERN U.S. FROM VA/NC INTO AL/GA... PULSE STORMS HAVE DEVELOPED IN VERY UNSTABLE AIR MASS WHERE MLCAPE IS GENERALLY BETWEEN 2000-3000 J/KG. ACTIVITY IS WITHIN REGIME OF WEAK LOW/UPPER LEVEL FLOW...THUS THE STORMS ARE DEVELOPING AND NOT MOVING VERY MUCH AND MERGING WITH SURROUNDING STORMS. SOME OF THIS ACTIVITY MAY PRODUCE LOCALIZED DAMAGING WINDS AS THEY COLLAPSE PUTTING OUT OUTFLOWS FOR NEWER STORMS TO DEVELOP THROUGH EARLY TONIGHT. ...PARTS OF THE SRN PLAINS INTO THE CENTRAL HIGH PLAINS... SEVERAL WEAK BOUNDARIES FROM PREVIOUS CONVECTION EXTENDS FROM S CENTRAL KS THRU NWRN OK...AND FROM NWRN AR INTO SWRN OK AND THE TX PANHANDLE. THIS AIR MASS TOO IS MODERATELY UNSTABLE WITH MLCAPE GENERALLY AROUND 2000 J/KG. UPSLOPE TYPE FLOW EXTENDS FROM THE TX PANHANDLE INTO ERN CO...THEN RETURN SLY FLOW IS CARRYING THIS MOISTURE INTO THE BLACK HILLS REGION OF SD. ONCE AGAIN...GIVEN THAT THE AIR MASS IS HOT AND MOIST WITH TEMPERATURES IN THE 90S IN THE PLAINS AND DEW POINTS IN THE 60S ACROSS SRN SECTIONS DOWN TO THE 50S IN ERN CO TO THE 40S IN SD...LAPSE RATES ARE FAVORABLE FOR STRONG STORMS WITH POSSIBLY STRONG GUSTY WINDS. ..MCCARTHY.. 08/03/2006  From swody1 at goshenarc.org Fri Aug 4 00:44:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 20:44:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040040 SWODY1 SPC AC 040039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0739 PM CDT THU AUG 03 2006 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...STATIONARY FRONT FROM SRN PLAINS TO LONG ISLAND SOUND... A NARROW BUT EXTENSIVE AXIS OF PERSISTENT LOW LEVEL CONVERGENCE ASSOCIATED WITH NEARLY STALLED FRONTAL ZONE...COUPLED WITH REGIONS OF MODEST TO STRONG INSTABILITY...WILL CONTINUE TO SUPPORT SCATTERED STRONG TO ISOLATED SEVERE TSTMS TONIGHT. POCKETS OF ACTIVITY PERSIST FROM THE TX/OK PNHDLS EWD AND NEWD ACROSS THE OH VALLEY...AND FROM LAKE ERIE ACROSS PARTS OF CNTRL PA. GENERALLY WEAK LARGE SCALE SUPPORT FOR UPWARD MOTION...LIMITED DEEP LAYER SHEAR...AND GRADUAL BOUNDARY LAYER STABILIZATION WITH LOSS OF INSOLATION ALL POINT TOWARD A DIMINISHING RISK OF SEVERE WEATHER. THEREFORE...ONLY A LOW PROBABILITY FOR DAMAGING WINDS WILL BE MAINTAINED ALONG THE FRONTAL ZONE FOR THE REMAINDER OF TONIGHT. ..CARBIN.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 05:07:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 01:07:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040508 SWODY1 SPC AC 040506 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1206 AM CDT FRI AUG 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID ATLANTIC AND SOUTHEAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN PLAINS FROM ND/NRN MN TO WRN LAKE SUPERIOR... ...SYNOPSIS... MODERATE ZONAL FLOW WITH PROGRESSIVE LOW-AMPLITUDE PERTURBATIONS WILL PERSIST ACROSS THE NRN BORDER STATES THROUGH FRIDAY. AS A MID LEVEL TROUGH PASSES OFF THE ERN SEABOARD...ASSOCIATED DEEP-LAYER FRONTAL ZONE WILL SETTLE SEWD ACROSS THE CNTRL/SRN APPALACHIANS AND MERGE WITH LEE-TROUGH FROM VA SWWD ACROSS THE CAROLINAS TODAY. THE BOUNDARY WILL EXTEND WWD FROM THE TN VALLEY INTO THE SRN PLAINS BENEATH WEAK ANTICYCLONIC FLOW ALOFT. FROM THE NRN ROCKIES TO THE NRN PLAINS...A WEAK SHORT WAVE TROUGH WILL PRECEED A STRONGER SYSTEM DIGGING SEWD FROM NWRN CANADA. THIS LEAD IMPULSE WILL ENHANCE WARM AIR ADVECTION AND LIFT FROM THE DAKOTAS EWD ACROSS NRN MN THROUGH TONIGHT...WHILE THE STRONGER DISTURBANCE DRIVES A COLD FRONT SEWD INTO ERN MT AND WRN ND THROUGH EARLY SATURDAY. A COUPLE OF WEAK WAVES WILL TRAVEL ALONG THE SRN/SWRN PERIPHERY OF THE SUBTROPICAL RIDGE AXIS. ONE OF THESE WAVES WILL CONTINUE TO TRACK ACROSS FL AND THE NERN GULF COAST THROUGH TODAY. THE OTHER WAVE WILL MOVE SLOWLY NWD FROM MEXICO AND ACROSS THE NM/AZ BORDER AREA DURING THIS FORECAST PERIOD. ...SRN DELMARVA SWWD TO GA... VERY MOIST AIR MASS AND HEATING WILL CONTRIBUTE TO THE DEVELOPMENT OF STRONG INSTABILITY AGAIN TODAY FROM THE APPALACHIANS EWD TO THE COAST. TSTMS WILL AGAIN DEVELOP ACROSS THE HIGHER TERRAIN AND NEAR LEE-TROUGH IN ADVANCE OF DEEPER FRONTAL CIRCULATION SPREADING INTO THE REGION THROUGH EVENING. WHILE EFFECTIVE SHEAR WILL REMAIN MEAGER GIVEN NO MORE THAN 20KT MID LEVEL FLOW...LARGE SCALE MID LEVEL DEFORMATION AXIS ATOP ABUNDANT BOUNDARIES TO FOCUS CONVECTION SHOULD SUPPORT NUMEROUS PULSE AND MULTICELL STORMS. STEEP THETA-E LAPSE RATES/HIGH DCAPE INVOF LEE-TROUGH/FRONT AND SEA-BREEZE MERGERS WILL PROMOTE WET DOWNBURST POTENTIAL WITH ANTICIPATED STORM COVERAGE WARRANTING HIGHER SEVERE PROBABILITIES/SLGT RISK. ...NRN PLAINS TO WRN LAKE SUPERIOR... LEADING LOW AMPLITUDE IMPULSE AND WEAK HEIGHT FALLS WILL SPREAD EAST FROM MT/WRN DAKOTAS COINCIDENT WITH INTENSE SURFACE HEATING ACROSS THE NRN HIGH PLAINS. VERY STEEP LAPSE RATES ATOP DRY BOUNDARY LAYER WILL RESULT IN STRONG INHIBITION OVER MUCH OF THE REGION THROUGH THE DAY. HOWEVER...PERSISTENT ASCENT AND DESTABILIZATION WITHIN WARM CONVEYOR BELT FROM ERN ND ACROSS MN MAY PROMOTE HIGH-BASED/ELEVATED TSTM DEVELOPMENT ACROSS THESE AREAS THROUGH THE AFTERNOON. THIS ACTIVITY MAY CONTINUE TO SPREAD EAST ACROSS NRN MN THROUGH THE PERIOD AS WARM FRONT STRENGTHENS AHEAD OF THE STRONGER IMPULSE DIGGING SEWD FROM CANADA. PRIMARY HAZARD WILL BE LARGE HAIL GIVEN STEEP LAPSE RATES AND STRONG SHEAR. HOWEVER...ISOLATED DAMAGING WINDS COULD ALSO EVOLVE IF ELEVATED CONVECTION CAN PERSIST NEAR EDGE OF THE CAP AND THEN MOVE/BACKBUILD INTO HEATED AND DEEPLY MIXED AIR MASS FROM ERN SD ACROSS CNTRL MN DURING THE AFTERNOON AND EVENING. ...TN VALLEY TO SRN PLAINS... ISOLATED WET DOWNBURSTS COULD OCCUR AS HEATING AIDS PULSE STORM DEVELOPMENT ALONG RESIDUAL FRONTAL ZONE THESE AREAS. VERY WEAK SHEAR AND MEAGER LAPSE RATES INDICATE SEVERE THREAT SHOULD REMAIN LIMITED IN TIME AND SPACE. ...SOUTHWEST... WET DOWNBURST ACTIVITY MAY ALSO INCREASE AS SUBTROPICAL IMPULSE ENHANCES TSTM ACTIVITY ACROSS THE SOUTHWEST. HOWEVER...WARM LAPSE RATES AND LIMITED SHEAR SUGGEST ONLY AN ISOLATED THREAT OF DAMAGING WINDS...BUT INCREASING POTENTIAL FOR LOCALLY HEAVY RAIN. ..CARBIN/JEWELL.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 13:00:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 09:00:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041300 SWODY1 SPC AC 041258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT FRI AUG 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLNS/UPR MS VLY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID AND S ATLANTIC CST... ...SYNOPSIS... SUBTROPICAL RIDGE WILL RETROGRADE SLIGHTLY THIS PERIOD AS LOW AMPLITUDE IMPULSE CONTINUES E TO THE CANADIAN MARITIMES. FARTHER N AND W...STRONGER DISTURBANCES NOW OVER BC EXPECTED TO PHASE OVER THE CANADIAN RCKYS LATER TODAY...BEFORE CONTINUING E AS A FAIRLY POTENT SHORTWAVE TROUGH INTO CNTRL/SRN SASKATCHEWAN. TRAILING FRONT WITH ERN SYSTEM WILL SETTLE SE ACROSS THE MID ATLANTIC AND TN VLY TODAY...WHILE DOWNSTREAM FROM THE BC/AB DISTURBANCE...EXPECT LEE LOW AND ASSOCIATED FRONTAL SYSTEM TO INTENSIFY OVER THE NRN PLNS. ...NRN PLNS... WEAK IMPULSE PRECEDING BC/AB DISTURBANCE WILL ENHANCE WARM ADVECTION/JET ENTRANCE REGION ASCENT OVER NRN/ERN ND AND NRN MN TODAY. BOUNDARY LAYER MOISTURE OVER REGION WILL REMAIN LIMITED. BUT COUPLED WITH MID LEVEL STEEP LAPSE RATES AND MODERATE/ UNIDIRECTIONAL CLOUD LAYER WLY FLOW...SETUP SHOULD SUPPORT A PERSISTENT AREA OF ELEVATED STORMS/POSSIBLE WEAK SUPERCELLS WITH MARGINALLY SEVERE HAIL. AS THE BOUNDARY LAYER WARMS AND LOW LEVEL LAPSE RATES STEEPEN...THIS ACTIVITY COULD ALSO YIELD LOCALLY DAMAGING WIND. SOME OF THE STORMS COULD SPREAD E TO WRN LK SUPERIOR EARLY SATURDAY. FARTHER S...EML SHOULD KEEP DEVELOPING WARM SECTOR CAPPED UNTIL LATE IN THE DAY. BUT CONVERGENCE ALONG LEE TROUGH COULD PROMOTE DEVELOPMENT OF WIDELY SCATTERED HIGH-BASED STORMS FROM CNTRL ND SSW INTO NW NEB LATE THIS AFTERNOON...WHERE THERMODYNAMIC ENVIRONMENT COULD SUPPORT A FEW MICROBURSTS. ...SRN DELMARVA SW INTO GA/TN VLY... HEATING OF VERY MOIST AIR IN PLACE INVOF WEAKENING COLD FRONT AND LEE TROUGH FROM THE SRN DELMARVA REGION INTO GA WILL BOOST MUCAPE TO AOA 2500 J/KG. EFFECTIVE DEEP WLY SHEAR WILL BE RATHER WEAK ...RANGING FROM 20-25 KTS IN NRN PART OF SLIGHT AREA TO LESS THAN 10 KTS IN SC. SLIGHTLY STRONGER ELY SHEAR WILL EXIST FARTHER S ACROSS SRN GA AND N FL...ON N SIDE OF W-MOVING UPR DISTURBANCE. WITH RESIDUAL UPR LEVEL DEFORMATION AXIS AND TERRAIN-INDUCED CIRCULATIONS TO FOSTER STORM INITIATION...SETUP SHOULD SUPPORT NUMEROUS AFTERNOON PULSE/MULTICELL STORMS. STEEP THETA-E LAPSE RATES AND HIGH DCAPE WILL PROMOTE WET DOWNBURST POTENTIAL. MORE ISOLATED WET MICROBURST ACTIVITY COULD OCCUR WWD ALONG TRAILING FRONT INTO THE TN VLY. ...SRN/ERN ID... SATELLITE LOOPS SHOW AN UPR IMPULSE LIFTING N ACROSS ERN NV ATTM...DOWNSTREAM FROM OFFSHORE LOW. INCREASING MID LEVEL MOISTURE AND UPR LEVEL DIVERGENCE IN ASSOCIATED DEFORMATION ZONE WILL REACH SRN/ERN ID AFTER MAX HEATING TIME TODAY...WHERE ENVIRONMENT COULD SUPPORT A SMALL CLUSTER OR TWO OF STORMS WITH LOCALLY DAMAGING WIND. ...SOUTHWEST... A FEW WET DOWNBURSTS MAY ALSO OCCUR OVER PARTS OF THE SOUTHWEST AS SUBTROPICAL IMPULSE ENHANCES TSTM COVERAGE OVER REGION. BUT WARM THERMODYNAMIC PROFILES AND VERY WEAK SHEAR SUGGEST THAT MAIN THREAT WILL BE LOCALLY HEAVY RAIN. ..CORFIDI/JEWELL.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 16:30:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 12:30:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041629 SWODY1 SPC AC 041628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT FRI AUG 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS NE ND INTO NRN MN.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FROM ERN VA ACROSS THE CAROLINAS TO GA/FL.... ...FL PENINSULA THIS AFTERNOON... A MID LEVEL LOW OVER CENTRAL FL WILL MOVE SLOWLY WWD THROUGH THE PERIOD. THE 12Z SOUNDING FROM TBW REVEALS 6.5-7 C/KM LAPSE RATES THROUGH THE LOWER TO MIDDLE TROPOSPHERE...AND A 500 MB TEMPERATURE OF -9 TO -10 C IN ASSOCIATION WITH THIS MID LEVEL LOW. AFTERNOON TEMPERATURES NEAR 90 F AND DEWPOINTS IN THE LOW-MID 70S WILL SUPPORT MLCAPE VALUES AOA 3000 J/KG. THUNDERSTORMS WILL LIKELY DEVELOP BY EARLY AFTERNOON...AND THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING DAMAGING WINDS WITH WET MICROBURSTS AND MARGINALLY SEVERE HAIL. ...SE ATLANTIC STATES THIS AFTERNOON... A MID LEVEL DEFORMATION ZONE EXISTS INVOF THE SRN APPALACHIANS...BETWEEN THE SRN FRINGE OF THE WLYS OVER THE OH VALLEY...AND THE MID LEVEL LOW IN THE ELYS OVER FL. A SURFACE COLD FRONT IS MOVING SEWD ACROSS THE CENTRAL/SRN APPALACHIANS...AND A PRE-FRONTAL TROUGH EXTENDS ALONG THE SE ATLANTIC COASTAL PLAINS FROM VA TO SE GA. SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON ALONG BOTH SURFACE BOUNDARIES AND OVER THE HIGHER TERRAIN OF THE WRN CAROLINAS. THE STRONGER INSTABILITY IS EXPECTED OVER THE COASTAL PLAINS WHERE AFTERNOON TEMPERATURES WILL REACH THE MID-UPPER 90S WITH DEWPOINTS IN THE 70S. STEEP LOW-LEVEL LAPSE RATES...MLCAPE OF 3000-4000 J/KG...DCAPE IN EXCESS OF 1000 J/KG...AND MINIMAL VERTICAL SHEAR WILL SUPPORT A FEW PULSE-TYPE STORMS CAPABLE OF PRODUCING WET MICROBURSTS WITH DAMAGING WINDS. ...NRN PLAINS THROUGH TONIGHT... AN ONGOING CLUSTER OF THUNDERSTORMS ALONG THE INTERNATIONAL BORDER WILL LIKELY PERSIST INTO THIS AFTERNOON ACROSS NE ND AND NRN MN. THIS CONVECTION APPEARS TO BE BASED IN THE 850-700 MB LAYER...IN ASSOCIATION WITH LOW-LEVEL WAA AND STEEP MID LEVEL LAPSE RATES SAMPLED IN THE 12Z BIS SOUNDING. CLOUDS ACROSS THE AREA WILL SLOW SURFACE HEATING...THOUGH THE CONVECTION COULD BECOME ROOTED NEAR THE GROUND WITH TEMPERATURES IN THE LOWER 80S. MARGINALLY SEVERE HAIL AND ISOLATED DAMAGING GUSTS WILL BE THE PRIMARY SEVERE THREATS. FARTHER W...STRONG SURFACE HEATING /AFTERNOON TEMPERATURES IN THE LOW-MID 90S/ WILL RESULT IN DEEP INVERTED-V PROFILES NEAR THE LEE CYCLONE IN WRN ND. THOUGH LOW-LEVEL MOISTURE IS SOMEWHAT LIMITED THIS AREA AND STORM COVERAGE MAY BE RATHER SPARSE...THE STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT VERY ISOLATED STRONG OUTFLOW WINDS LATER THIS AFTERNOON/EVENING. A PRONOUNCED MID LEVEL TROUGH NOW OVER SE BRITISH COLUMBIA WILL APPROACH THE NRN HIGH PLAINS LATE IN THE PERIOD...THOUGH MARGINAL MOISTURE AND INCREASING CONVECTIVE INHIBITION WILL TEND TO LIMIT THE THREAT FOR OVERNIGHT STORMS. ...SE ID THIS AFTERNOON... WATER VAPOR IMAGERY SHOWS A WEAK MID LEVEL WAVE MOVING NNEWD FROM ERN NV/NW UT TOWARD SE ID. SHORT TERM FORECAST SOUNDINGS...AND THE 12Z SLC SOUNDING MODIFIED FOR SURFACE HEATING...SHOW THE POTENTIAL FOR GUSTY OUTFLOW WINDS AND PERHAPS SMALL HAIL. ...CENTRAL OK TO CENTRAL AR THIS AFTERNOON... A QUASI-STATIONARY FRONT IS LOCATED NEAR I-40. STRONG SURFACE HEATING ALONG AND S OF THE FRONT WILL RESULT IN THE DEVELOPMENT OF MODERATE INSTABILITY AND A RELATIVELY DEEP BOUNDARY LAYER THIS AFTERNOON. WIDELY SCATTERED THUNDERSTORMS WILL LIKELY FORM ALONG THE FRONT BY MID AFTERNOON...A FEW OF WHICH WILL PRODUCE STRONG DOWNBURST WINDS. ..THOMPSON/TAYLOR.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 20:06:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 16:06:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042004 SWODY1 SPC AC 042003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT FRI AUG 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THRU EARLY TONIGHT ACROSS PARTS OF THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT ACROSS PARTS OF THE NRN PLAINS INTO NRN MN.... ...SYNOPSIS... LARGE MID/UPPER LEVEL RIDGE EXTENDS FROMCENTRAL/SRN HIGH PLAINS EWD INTO THE TN VALLEY AND CAROLINAS. MAIN BAND OF WESTERLIES RUN ALONG THE NRN TIER OF STATES FROM MT THRU THE GREAT LAKES WITH SEVERAL EMBEDDED SHORTWAVES. VIGOROUS MID/UPPER LEVEL LOW IS MOVG SEWD ACROSS ERN BRITISH COLUMBIA AND SRN ALBERTA AND IS EXPECTED TO BE INTO S CENTRAL SASKATCHEWAN. ...MID ATLANTIC/SERN STATES... LATEST SURFACE ANALYSIS SHOWS THAT COLD FRONTAL BOUNDARY EXTENDS FROM SERN MD...THEN CONTINUES SWWD/WWD AS A COMBINATION WEAK WIND SHIFT/CONVECTIVE BOUNDARY THRU THE TN VALLEY INTO NRN AR. SFC DEWPOINTS ARE IN THE 70S FROM SERN VA INTO THE GULF COAST REGION...FARTHER S THAN THE PAST FEW DAYS. THUS...FOCUS OF CONVECTION WILL BE IN THE FORM OF PULSE-TYPE ACTIVITY AND ITS ASSOCIATED BOUNDARIES FOR THE REMAINDER OF THE AFTN AND EARLY TONIGHT WITH THE MAIN THREAT BEING DAMAGING WINDS. ...PARTS OF THE NRN PLAINS EWD THRU NRN MN... LOW LEVEL WARM ADVECTION WILL BE INCREASING THRU TONIGHT ACROSS THE REGION. SWLY LOW LEVEL JET 35-45 KT WILL DEVELOP FROMCENTRAL NEB THRU N CENTRAL MN WHICH WILL ENHANCE VERTICAL SHEAR PROFILES ACROSS THE REGION. AIR MASS CONTINUES TO DESTABILIZE ACROSS CENTRAL ND WITH MLCAPE TO 1500 J/KG. PROBLEM ATTM LOKS TO BE LACK OF SUFFICIENT LOW LEVEL MOISTURE WITH DEW POINTS IN THE MID 50S. BUT WITH DEEP LAYER SHEAR OF 50-60 KT ACROSS THE NRN HALF OF ND...AND THAT THE SW CANADA SHORTWAVE TROUGH WILL BE MOVING INTO SASKATCHEWAN...EXPECT STRONG/SEVERE THUNDERSTORMS TO BE POSSIBLE AFTER 05/06Z ACROSS THIS REGION IF STORMS CAN DEVELOP ABOVE LOW LEVEL CAPPING INVERSION. ..MCCARTHY.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 20:09:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 16:09:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042008 SWODY1 SPC AC 042006 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT FRI AUG 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THRU EARLY TONIGHT ACROSS PARTS OF THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT ACROSS PARTS OF THE NRN PLAINS INTO NRN MN.... ...SYNOPSIS... LARGE MID/UPPER LEVEL RIDGE EXTENDS FROM CENTRAL/SRN HIGH PLAINS EWD INTO THE TN VALLEY AND CAROLINAS. MAIN BAND OF WESTERLIES RUNS ALONG THE NRN TIER OF STATES FROM MT THRU THE GREAT LAKES WITH SEVERAL EMBEDDED SHORTWAVES. VIGOROUS MID/UPPER LEVEL LOW IS MOVG SEWD ACROSS ERN BRITISH COLUMBIA AND SRN ALBERTA AND IS EXPECTED TO BE INTO S CENTRAL SASKATCHEWAN BY END OF THE PERIOD. ...MID ATLANTIC/SERN STATES... LATEST SURFACE ANALYSIS SHOWS THAT COLD FRONTAL BOUNDARY EXTENDS FROM SERN MD...THEN CONTINUES SWWD/WWD AS A COMBINATION WEAK WIND SHIFT/CONVECTIVE BOUNDARY THRU THE TN VALLEY INTO NRN AR. SFC DEWPOINTS ARE IN THE 70S FROM SERN VA INTO THE GULF COAST REGION...FARTHER S THAN THE PAST FEW DAYS. THUS...FOCUS OF CONVECTION WILL BE IN THE FORM OF PULSE-TYPE ACTIVITY AND ITS ASSOCIATED BOUNDARIES FOR THE REMAINDER OF THE AFTN AND EARLY TONIGHT WITH THE MAIN THREAT BEING DAMAGING WINDS. ...PARTS OF THE NRN PLAINS EWD THRU NRN MN... LOW LEVEL WARM ADVECTION WILL BE INCREASING THRU TONIGHT ACROSS THE REGION. SWLY LOW LEVEL JET 35-45 KT WILL DEVELOP FROM CENTRAL NEB THRU N CENTRAL MN WHICH WILL ENHANCE VERTICAL SHEAR PROFILES ACROSS THE REGION. AIR MASS CONTINUES TO DESTABILIZE ACROSS CENTRAL ND WITH MLCAPE TO 1500 J/KG. PROBLEM ATTM LOOKS TO BE LACK OF SUFFICIENT LOW LEVEL MOISTURE WITH DEW POINTS IN THE MID 50S. BUT WITH DEEP LAYER SHEAR OF 50-60 KT ACROSS THE NRN HALF OF ND...AND THAT THE SW CANADA SHORTWAVE TROUGH WILL BE MOVING INTO SASKATCHEWAN...EXPECT STRONG/SEVERE THUNDERSTORMS TO BE POSSIBLE AFTER 05/06Z ACROSS THIS REGION IF STORMS CAN DEVELOP ABOVE LOW LEVEL CAPPING INVERSION. ..MCCARTHY.. 08/04/2006  From swody1 at goshenarc.org Sat Aug 5 00:59:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 20:59:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050052 SWODY1 SPC AC 050051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 PM CDT FRI AUG 04 2006 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE DAKOTAS... ...NRN PLAINS... MODEST QG-FORCING FOR ASCENT SPREADING ACROSS THE DAKOTAS WILL CONTINUE TO LOCALLY OVERCOME STRONG INHIBITION AND MAINTAIN THE CHANCE FOR SCATTERED SEVERE TSTMS FROM THE CNTRL TO ERN DAKOTAS TONIGHT. EFFECTIVE SHEAR AND LAPSE RATES ACROSS THE REGION REMAIN SUPPORTIVE OF ISOLATED SUPERCELLS AND LINE SEGMENTS CAPABLE OF PRODUCING HAIL AND HIGH WINDS. A STRONGER SYSTEM WILL DIG SEWD ACROSS NERN MT AND NWRN ND THROUGH DAYBREAK. FORCING/COLD FRONT ASSOCIATED WITH THIS SYSTEM MAY SPUR ADDITIONAL SEVERE STORM DEVELOPMENT OVER PARTS OF NWRN/NRN ND INTO EARLY SATURDAY. FARTHER EAST...LOW-AMPLITUDE SHORT WAVE TROUGH NOW MOVING OVER THE DAKOTAS MAY ENHANCE WARM ADVECTION AND MASS TRANSPORT ON THE EDGE OF THE CAP FROM NRN MN TO WRN SECTIONS OF THE U.P. OF MI/LAKE SUPERIOR. A FEW STRONG STORMS WITH SOME HAIL POTENTIAL MAY SPREAD ACROSS THESE AREAS OVERNIGHT. ...NORTHEAST GULF COAST... LARGE CLUSTER OF MULTICELLULAR CONVECTION HAS GROWN UPSCALE AND WAS DRIFTING SWWD ACROSS SWRN GA AND NRN FL THIS EVENING. THIS COMPLEX OF STORMS SHOULD CONTINUE TO POSE A THREAT OF ISOLATED WET DOWNBURSTS FOR AT LEAST ANOTHER HOUR OR SO GIVEN VERY MOIST AND UNSTABLE CONDITIONS REMAINING ACROSS THE REGION AND SOME LARGE SCALE SUPPORT FROM UPPER LOW TRACKING WWD ACROSS FL. ...SOUTHEAST... ISOLATED ACTIVITY EXPECTED TO PERSIST...AND MAY INCREASE SOMEWHAT...IN WEAKLY SHEARED BUT VERY UNSTABLE AIR MASS FROM NRN GA ACROSS THE CAROLINAS AND SERN VA. RESIDUAL COLD FRONT AND LEE TROUGH...IN ADDITION TO NUMEROUS COMPOSITE OUTFLOW AND SEA BREEZE BOUNDARIES...MAY CONTINUE TO AID WIDELY SCATTERED UPDRAFT/PULSE STORM DEVELOPMENT. THE REGION ALSO LIES BENEATH FAVORABLE DIFFLUENT FLOW PATTERN ALOFT WHICH COULD MAINTAIN AT LEAST AN ISOLATED SEVERE THREAT DESPITE TIME OF DAY. ...ERN OK/SWRN AR... MESOSCALE ASCENT BEHIND LEADING EDGE OF WWD MOVING CONVECTIVE OUTFLOW FROM ERN OK INTO SWRN AR MAY CONTINUE TO PROMOTE PULSE STORM DEVELOPMENT OVER THESE AREAS FOR ANOTHER HOUR OR SO. BRIEF WIND DAMAGE POTENTIAL WILL BE GREATEST BENEATH UPDRAFTS FORMING OR DRIFTING INTO HOT AND DEEPLY MIXED AIR MASS AROUND THE ARKLATEX OVER THE NEXT 1-2 HOURS. ...NRN NEW ENGLAND... LIFT ASSOCIATED WITH A COLD FRONT APPROACHING WARM AND WEAKLY UNSTABLE AIR MASS OVER MAINE HAS RESULTED IN AN ARC OF STRONG STORMS OVER THIS REGION SINCE LATE AFTERNOON. MID LEVEL JET STREAK AND ASSOCIATED FRONT WILL CONTINUE TO SPREAD SEWD THROUGH TONIGHT AS BOUNDARY LAYER BECOMES INCREASINGLY STABLE. LOCALLY STRONG WIND GUSTS MAY ACCOMPANY SOME OF THE STRONGER CORES OVER THE NEXT HOUR BUT SEVERE WEATHER POTENTIAL WITH THIS ACTIVITY APPEARS TO BE LOW. ..CARBIN.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 05:29:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 01:29:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050528 SWODY1 SPC AC 050527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 AM CDT SAT AUG 05 2006 VALID 051200Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN NORTH DAKOTA AND NERN SOUTH DAKOTA ACROSS MUCH OF MINNESOTA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM THE CNTRL DAKOTAS AND NRN NEB...EAST ACROSS NRN IA AND THE UPPER MS VALLEY/WRN GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NORTHEAST GULF COAST AND PARTS OF THE SOUTHEAST... ...WIDESPREAD SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND LARGE HAIL ARE EXPECTED TO DEVELOP EAST ACROSS PARTS OF THE DAKOTAS AND MINNESOTA THIS AFTERNOON AND TONIGHT... ...SYNOPSIS... BROAD MID-UPPER LEVEL SUBTROPICAL RIDGE AXIS WILL REMAIN SITUATED ACROSS THE SCNTRL U.S. FROM THE FOUR CORNERS REGION EWD TO THE MID ATLANTIC AND SOUTHEAST. BELT OF ZONAL NRN STREAM FLOW WILL CONTAIN A POTENT...PROGRESSIVE...AND COMPACT SHORT WAVE DISTURBANCE WHICH WILL TRANSLATE EWD FROM NERN MT TO SRN ONTARIO AND THE UPPER MS VALLEY DURING THE PERIOD. WHILE ASSOCIATED SURFACE CYCLOGENESIS WITH THIS NRN STREAM IMPULSE WILL OCCUR OVER THE CANADIAN PRAIRIES THROUGH THE DAY TODAY...MODEST HEIGHT FALLS AND INCREASINGLY DIFFLUENT FLOW ON THE NOSE 0F 50-70 KT MID LEVEL JET WILL SPREAD EAST ATOP STRONGLY UNSTABLE WARM SECTOR FROM THE ERN DAKOTAS TO MN. SEVERE STORMS ARE EXPECTED TO FORM AHEAD OF ASSOCIATED COLD FRONT WHICH WILL SWEEP ESEWD ACROSS THE NRN PLAINS TO THE WRN GREAT LAKES REGION FROM LATE THIS AFTERNOON THROUGH EARLY SUNDAY. ...NRN PLAINS TO UPPER MS VALLEY... INGREDIENTS APPEAR TO BE COMING TOGETHER FOR POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE ACROSS ERN ND...NERN SD...AND MN LATER THIS AFTERNOON AND TONIGHT. A LEADING LOW-AMPLITUDE SHORT WAVE TROUGH AND MODEST LOW LEVEL JET DIRECTED INTO MN WERE AIDING LOW LEVEL MOISTURE RETURN AND MAINTAINING WEAK CONVECTIVE ACTIVITY ACROSS THE AREA ATTM. EARLY ELEVATED CONVECTION IS EXPECTED TO DISSIPATE RAPIDLY AFTER SUNRISE AS LOW LEVEL FLOW FIELDS ADJUST TO INFLUENCE OF STRONGER UPSTREAM IMPULSE MOVING ESEWD FROM NERN MT. INTENSE SURFACE HEATING BENEATH PRONOUNCED ELEVATED MIXED LAYER AND ADIABATIC COOLING ALOFT ASSOCIATED WITH THE APPROACHING TROUGH WILL LEAD TO THE DEVELOPMENT OF STRONG INSTABILITY AHEAD OF DRYLINE/COLD FRONT BY AFTERNOON. MLCAPE ACROSS THE CNTRL/ERN DAKOTAS SHOULD EASILY CLIMB TO 2000 J/KG WITH INITIALLY STRONG CAPPING ALLOWING LOW LEVEL MOISTURE AND INSTABILITY TO CONTINUE TO BUILD THROUGH THE AFTERNOON. AS TEMPERATURES CLIMB THROUGH THE 90S F...AND STRONGER QG FORCING ARRIVES ATOP THE VERY UNSTABLE WARM SECTOR...REMAINING INHIBITION WILL FIRST BE OVERCOME ACROSS ERN/NERN ND WHERE RAPID TO EXPLOSIVE TSTM DEVELOPMENT SHOULD ENSUE BEFORE LATE AFTERNOON. ADDITIONAL SCATTERED DEVELOPMENT SWD/SWWD ACROSS THE WARM SECTOR MAY OCCUR FROM LATE AFTERNOON THROUGH EARLY EVENING AS STRONG DYNAMIC FORCING ASSOCIATED WITH THE TROUGH AND DRYLINE/FRONT ACT TO OVERCOME THE CAP FROM NERN SD SWWD INTO THE NCNTRL PLAINS. VERTICAL SHEAR AND FORCING WILL BE MORE THAN ADEQUATE FOR ORGANIZED SEVERE STORMS WITH INITIAL ACTIVITY RAPIDLY BECOMING SUPERCELLULAR AND PRODUCING VERY LARGE HAIL. FORECAST SOUNDINGS ALSO DEPICT SUFFICIENT DIRECTIONAL SHEAR AND LOW LEVEL CAPE IN THE STORM UPDRAFT LAYER FOR POTENTIALLY STRONG LOW-LEVEL MESOCYCLONES. TORNADOES MAY DEVELOP FROM DISCRETE STORMS PERSISTING NEAR RESIDUAL OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES...AS WELL AS FROM STRONG UPDRAFT/DOWNDRAFT COUPLETS OCCURRING NEAR BREAKS IN ANY LINE SEGMENTS. CONVECTION SHOULD TREND TOWARD SQUALL-LINEAR MODE INTO THE EVENING WITH WIDESPREAD DAMAGING WINDS POSSIBLE AS STORM COVERAGE INCREASES AND RESULTANT COLD POOLS STRENGTHEN AND MERGE. STRONG MID LEVEL DRY PUNCH AND ENHANCED MESOSCALE ASCENT ON THE EDGE OF THE PLAINS CAPPING INVERSION SHOULD MAINTAIN THE THREAT OF BOWING LINE SEGMENTS...HAIL...AND ISOLATED/BRIEF TORNADOES ACROSS MN/NRN IA...INTO WI...AND PERHAPS THE U.P. OF MI...INTO LATE SATURDAY NIGHT/EARLY SUNDAY. ...NERN GULF COAST/SOUTHEAST... VERY MOIST AND INCREASINGLY UNSTABLE AIR MASS WILL AGAIN SUPPORT THE DEVELOPMENT OF NUMEROUS PULSE/MULTICELL STORMS ACROSS THESE AREAS TODAY. WHILE WEAK SHEAR WILL LIMIT OVERALL ORGANIZATION... ACTIVITY PERSISTING ALONG RESIDUAL FRONTAL BOUNDARY...AND ALSO AIDED BY LARGE SCALE INFLUENCE OF WWD MOVING TROUGH OVER THE ERN GULF...WILL POSE SOME THREAT FOR LOCALLY DAMAGING WINDS AND MARGINALLY SEVERE HAIL. ..CARBIN/GUYER.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 13:00:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 09:00:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051300 SWODY1 SPC AC 051258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT SAT AUG 05 2006 VALID 051300Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN ND INTO ERN SD AND MUCH OF NRN / WRN MN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA SWD / EWD INTO THE MID MO AND UPR MS VLYS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL GULF CST REGION... ...SYNOPSIS... UPR RIDGE WILL REMAIN ANCHORED OVER THE SRN PLNS THIS PERIOD AS POTENT SHORTWAVE IMPULSE NOW OVER SRN SASKATCHEWAN SWEEPS E IN STRONG ZONAL JET JUST N OF THE CANADIAN BORDER. THE SYSTEM SHOULD AMPLIFY INTO A CLOSED LOW NEAR LK WINNIPEG EARLY TONIGHT...AND REACH WRN ONTARIO EARLY SUNDAY. FARTHER S...SATELLITE AND VWP DATA SHOW TWO WEAKER DISTURBANCES IN THE BELT OF MODERATE FLOW TOPPING THE PLNS RIDGE. ONE OF THE THESE IS OVER FSD/SUX ATTM...AND THE OTHER OVER N CNTRL WY. AT THE SURFACE...COLD FRONT ATTENDING CANADIAN IMPULSE EXPECTED TO MOVE STEADILY SE ACROSS THE NRN PLNS TODAY...AND INTO THE UPR MS VLY/CNTRL PLNS TONIGHT/EARLY SUNDAY. AHEAD OF THE COLD FRONT... LATEST SURFACE DATA AND SATELLITE/GPS PWS SHOW MOISTURE RETURN CONTINUING INVOF DIFFUSE WARM FRONT EXTENDING FROM THE CNTRL DAKOTAS SSE INTO ERN KS/NE OK. MOISTURE LIKELY WILL CONTINUE TO SPREAD NWD INTO THE ERN DAKOTAS/WRN MN TODAY. SURFACE DEWPOINTS COULD REACH THE MID 60S IN THE RED RVR VLY REGION BY MID AFTERNOON...WITH VALUES IN THE UPPER 60S POSSIBLE FARTHER S ACROSS ERN SD/SW MN. THE W/E BREADTH OF THE MOISTURE RETURN AXIS WILL...HOWEVER...LIKELY REMAIN LIMITED AS GRT LKS SURFACE RIDGE EXPECTED TO EDGE ONLY SLOWLY EWD. ...NRN PLNS/UPR MS VLY... ELEVATED TSTMS ARE ALREADY IN PROGRESS IN NW/N CNTRL ND...IN WARM ADVECTION ZONE DOWNSTREAM FROM SASKATCHEWAN TROUGH. THIS ACTIVITY SHOULD CONTINUE E ACROSS ND THROUGH THE DAY...WITH SOME SWD DEVELOPMENT LIKELY OVER TIME AS STORMS/FORCING ENCOUNTER INCREASING LOW LEVEL MOISTURE RETURN AND OVERCOME CAP. COUPLED WITH EXPECTED SURFACE HEATING AND CONTINUED E/SEWD PROGRESS OF COLD FRONT...EXPECT THAT CELLS WILL EVENTUALLY BECOME SURFACE-BASED AND MARKEDLY STRENGTHEN...MOST LIKELY OVER THE RED RVR VLY. OTHER VIGOROUS STORMS SHOULD FORM A BIT LATER IN THE AFTERNOON SWD ALONG MERGING COLD FRONT/PREFRONTAL TROUGH OVER ERN SD/WRN MN. AMPLE DEEP SPEED AND DIRECTIONAL SHEAR WILL BE PRESENT FOR SUSTAINED SUPERCELLS...ESPECIALLY IN ND AND NRN MN...WHERE 500 MB WLY FLOW WILL INCREASE TO AROUND 50 KTS ON SRN SIDE OF UPR TROUGH. SOMEWHAT WEAKER DEEP SHEAR WILL BE COMPENSATED BY GREATER INSTABILITY /SBCAPE TO 3000 J PER KG/ TO SUPPORT SUSTAINED UPDRAFTS/SUPERCELLS SWD INTO ERN/SRN SD AND SW MN. BY EARLY EVENING...STRONG STORMS COULD DEVELOP SWD INTO NRN NEB. COMBINATION OF MODERATE TO STRONG DEEP SHEAR...STEEP MID LEVEL LAPSE RATES AND INCREASING MOISTURE LIKELY WILL PROMOTE A FEW UPDRAFTS WITH VERY LARGE HAIL FROM THE RED RVR VLY S/SW INTO PARTS OF SD/WRN MN. AND...WHILE OVERALL CONDITIONS DO NOT APPEAR IDEAL...A FEW TORNADOES ALSO APPEAR POSSIBLE...ESPECIALLY DURING EXPECTED PERIOD OF STORM INTENSIFICATION IN THE RED RVR VLY...AND DURING EARLY STAGES OF STORM DEVELOPMENT IN ERN SD/SW MN. FOCUSED AND LINEAR FORCING FOR ASCENT SUGGEST THAT ACTIVITY WILL FAIRLY QUICKLY ORGANIZE INTO A BROKEN LINE MODE THIS EVENING. EMBEDDED SUPERCELLS WILL CONTINUE TO POSE A THREAT FOR HIGH WIND/HAIL AND ISOLATED TORNADOES...ESPECIALLY BENEATH BELT OF STRONGER FLOW ALOFT IN NRN MN...AND INVOF MERGING BOUNDARIES SRN MN/SE SD. WHILE THE SRN MN/SE SD ACTIVITY MAY REMAIN SEVERE INTO SUNDAY MORNING...AND FORWARD-PROPAGATE E INTO NRN IA/SW WI... NARROW NATURE OF INSTABILITY AXIS SHOULD LIMIT EWD EXTENT OF HIGH-END /DERECHO/ SEVERE THREAT INTO THE LK SUPERIOR REGION. ...NERN GULF COAST/SOUTHEAST... STRONGLY HEATED...VERY MOIST/UNSTABLE AIR WILL AGAIN SUPPORT POCKETS OF DIURNAL PULSE/MULTICELL STORMS IN AREAS WHERE DEEP CONFLUENCE IS FAVORED ON LEADING EDGE OF ELY WAVE CROSSING THE SERN STATES. WHILE WEAK SHEAR WILL LIMIT ORGANIZATION...SOME STORMS WILL POSE A THREAT FOR LOCALLY DAMAGING WIND/MARGINALLY SEVERE HAIL. ..CORFIDI/GUYER.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 16:38:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 12:38:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051638 SWODY1 SPC AC 051636 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT SAT AUG 05 2006 VALID 051630Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS THE ERN DAKOTAS AND MN.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA...FROM THE NRN PLAINS TO THE UPPER MS VALLEY.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FROM LA/SRN MS TO CENTRAL GA AND SC.... ...NRN PLAINS AND UPPER MS VALLEY THROUGH TONIGHT... A STRONG MID LEVEL SHORTWAVE TROUGH OVER SRN SASKATCHEWAN WILL MOVE EWD OVER ND/SRN MANITOBA TODAY AND INTO WRN ONTARIO/NRN MN TONIGHT. AN ASSOCIATED SURFACE COLD FRONT ACROSS WRN ND THIS MORNING WILL MOVE SEWD ACROSS ERN ND AND CENTRAL SD BY THIS EVENING...REACHING AN AXIS FROM CENTRAL NEB TO NW IA TO NW WI BY 06/12Z. A SEPARATE LEE CYCLONE IN SW SD WILL GRADUALLY FILL AND DRIFT SWD/SEWD THROUGH TONIGHT. THE COLD FRONT IS EXPECTED TO BE THE PRIMARY FOCUS FOR SEVERE THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON INTO EARLY TONIGHT. THE REMNANTS OF OVERNIGHT CONVECTION...ASSOCIATED WITH AN INITIAL MID LEVEL WAVE NOW MOVING OVER MN/IA...PERSIST OVER SRN IA. BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S ARE RETURNING NWD ACROSS THE ERN DAKOTAS TO THE W OF THIS CONVECTION...THOUGH THE RICHEST MOISTURE IS CONFINED TO AREAS FROM ERN KS SWD TO THE GULF COAST. ANOTHER MINOR MID LEVEL WAVE IS MOVING EWD FROM NW SD/SE MT INTO CENTRAL ND. THE BAND OF CLOUDS OVER CENTRAL ND AND THE ELEVATED THUNDERSTORMS IN NE ND APPEAR TO BE ASSOCIATED WITH THIS WAVE...AND LOCAL VWP/S CONFIRM A PRONOUNCED VEERING OF LOW-LEVEL FLOW IN ND WITH PASSAGE OF THIS WAVE. THE 12Z BIS SOUNDING REVEALED VERY STEEP MID LEVEL LAPSE RATES...BUT A STRONG CAP FOR SURFACE PARCELS AND CONVECTIVE TEMPERATURES IN THE MID 90S. THE CLOUDS...MODEST MOISTURE...AND STRONG CAP ALL SUGGEST THAT SURFACE-BASED THUNDERSTORM DEVELOPMENT WILL LIKELY BE CONFINED TO THE IMMEDIATE COLD FRONT THIS AFTERNOON/EVENING ACROSS THE ERN DAKOTAS INTO WRN MN. MODIFYING THE 12Z BIS AND MODEL FORECAST SOUNDINGS FOR EXPECTED AFTERNOON BOUNDARY LAYER CONDITIONS...MLCAPE VALUES RANGE FROM 1500 J/KG ACROSS NW MN TO 3000 J/KG INVOF SE SD WHERE RICHER MOISTURE WILL SPREAD NWD ALONG THE MO RIVER VALLEY. DEEP LAYER VERTICAL SHEAR MAGNITUDE AND ORIENTATION WITH RESPECT TO THE FRONT APPEARS SUPPORTIVE OF A BROKEN BAND OF SUPERCELLS AND/OR SHORT LINE SEGMENTS THROUGH THE AFTERNOON/EVENING. VERY LARGE HAIL AND DAMAGING WINDS ARE LIKELY WITH ANY SUPERCELLS IN THE LINE. A COUPLE OF TORNADOES WILL ALSO BE POSSIBLE THIS EVENING...WITH A LITTLE GREATER THREAT IN MN WHERE LOW-LEVEL SHEAR/MOISTURE WILL BE SOMEWHAT GREATER THAN AREAS FARTHER W. ...GULF AND SE ATLANTIC COASTS THIS AFTERNOON... LOW-LEVEL DRYING HAS OCCURRED ACROSS THE SE ATLANTIC STATES COMPARED TO YESTERDAY MORNING...AS THE MID LEVEL WAVE IN THE ELYS PROGRESSES WWD OVER THE NE GULF AND FL PANHANDLE/SRN AL. IT APPEARS THAT THE GREATER INSTABILITY THIS AFTERNOON WILL BE FROM SRN MS INTO LA IN ADVANCE OF THE MID LEVEL WAVE. THE NE MID LEVEL FLOW WILL FAVOR MULTICELL CLUSTERS THAT MOVE INTO THE LOW-LEVEL HEAT/MOISTURE AXIS...WHILE VERTICAL PROFILES FAVOR A FEW STORMS WITH WET MICROBURSTS AND PERHAPS MARGINALLY SEVERE HAIL. THOUGH DEEP LAYER FLOW IS WEAK OVER THE CAROLINAS...A SURFACE FRONT WILL PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON. DEWPOINTS IN THE 70S AND AFTERNOON TEMPERATURES IN THE 90S WILL SUPPORT MLCAPE VALUES OF 2000-3000 J/KG...ALONG WITH DCAPE VALUES IN EXCESS OF 1000 J/KG. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING DAMAGING DOWNBURST WINDS. ACROSS FL AND SE GA...SCATTERED SEA BREEZE STORMS WILL OCCUR AGAIN THIS AFTERNOON...THOUGH THE SEVERE STORM THREAT WILL BE LIMITED BY WARMING MID LEVEL TEMPERATURES AND REDUCED INSTABILITY COMPARED TO YESTERDAY. ..THOMPSON/TAYLOR.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 19:49:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 15:49:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051949 SWODY1 SPC AC 051947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SAT AUG 05 2006 VALID 052000Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MN...ND...SD... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS...CNTRL PLAINS AND NRN MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SERN U.S.... ...NRN AND CNTRL PLAINS/UPPER MS VALLEY... LATEST WATER VAPOR IMAGERY SHOWS A WELL-DEFINED UPPER-LEVEL TROUGH MOVING EWD ACROSS SASKATCHEWAN AND THE NRN HIGH PLAINS WITH A LEAD TROUGH OVER ERN ND. AT THE SFC....A COLD FRONT IS LOCATED IN CNTRL ND AND NW SD WITH SFC DEWPOINTS ACROSS THE WARM SECTOR IN THE 60S F RESULTING IN MODERATE TO STRONG INSTABILITY. THUNDERSTORMS ARE DEVELOPING IN SE ND AND NW MN ALONG THE LEADING EDGE OF LARGE-SCALE ASCENT ASSOCIATED WITH THE LEAD SHORTWAVE TROUGH. STORM COVERAGE SHOULD CONTINUE TO EXPAND LATE THIS AFTERNOON ALONG THE INSTABILITY AXIS AS LARGE-SCALE ASCENT CONTINUES TO INCREASE FROM WEST TO EAST ACROSS THE REGION. OBJECTIVE ANALYSIS CURRENTLY SHOWS A 70 KT MID-LEVEL JET OVER NW ND WITH STRONGER MID-LEVEL FLOW SPREADING EWD ACROSS THE DAKOTAS. THIS WILL STRENGTHEN DEEP LAYER SHEAR ACROSS THE REGION WITH 0-6 KM SHEAR VALUES LIKELY REACHING 40 TO 50 KT ACROSS THE MODERATE RISK AREA BY LATE AFTERNOON/EARLY EVENING. IN ADDITION...LAPSE RATES WILL CONTINUE TO STEEPEN WHICH WITH THE INCREASING SHEAR SHOULD BECOME FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE STRONGEST SUPERCELLS SHOULD BE CAPABLE OF PRODUCING VERY LARGE HAIL AND WIND DAMAGE. VERY STRONG WIND GUSTS AND A FEW TORNADOES WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS AND/OR BOW ECHOES ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS LATE THIS AFTERNOON AND EARLY THIS EVENING. THE SEVERE THREAT SHOULD CONTINUE THROUGH THE EVENING AND POSSIBLY INTO THE OVERNIGHT PERIOD AS A LINEAR MCS ORGANIZES AHEAD OF THE FRONT AND MOVES EWD ACROSS THE REGION. ...SERN U.S... A WEAK FLOW REGIME IS CURRENTLY IN PLACE ACROSS THE SERN U.S. WITH A STATIONARY FRONT LOCATED FROM LA EXTENDING ENEWD ACROSS CNTRL MS...NCNTRL AL...NRN GA AND SC. MODERATE INSTABILITY IS PRESENT ALONG THE BOUNDARY AND LOW-LEVEL CONVERGENCE IS HELPING INITIATE SCATTERED TO NUMEROUS THUNDERSTORMS ACROSS THE REGION. ALTHOUGH WIND SHEAR PROFILES ARE RELATIVELY WEAK...LOW-LEVEL LAPSE RATES ARE VERY STEEP AND EXCEED 8.0 C/KM IN SOME AREAS. THIS SHOULD BE FAVORABLE FOR ISOLATED DAMAGING WINDS WITH THE STRONGER CELLS THROUGH THE REMAINDER OF THE AFTERNOON. ..BROYLES.. 08/05/2006  From swody1 at goshenarc.org Sun Aug 6 01:07:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 21:07:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060106 SWODY1 SPC AC 060104 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0804 PM CDT SAT AUG 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLAINS AND UPPER MS VALLEY... ...ERN DAKOTAS AND MN... POTENT MID-UPPER LEVEL DISTURBANCE WAS CLEARLY EVIDENT ON WATER VAPOR IMAGERY ACROSS SRN MANITOBA AND NRN ND THIS EVENING. DIFFLUENT MID LEVEL FLOW FIELD AHEAD OF THIS IMPULSE WAS AIDING DEEP LAYER ASCENT ALONG AN ADVANCING ASSOCIATED COLD FRONT FROM NRN MN SWWD INTO NCNTRL SD. STRONGEST DYNAMIC FORCING ASSOCIATED WITH THE MID LEVEL SYSTEM WILL CONTINUE TO TRAVEL ACROSS NRN MN THROUGH TONIGHT WHILE SOMEWHAT WEAKER LARGE SCALE FORCING WILL ACCOMPANY THE FRONTAL PASSAGE FROM ERN SD ACROSS SRN MN AND NRN IA THROUGH EARLY SUNDAY. A FEW INTENSE SUPERCELLS HAVE DEVELOPED AHEAD OF THE FRONT... ACROSS ERN ND AND NRN MN...WHERE DYNAMIC FORCING HAS ACTED TO LOCALLY OVERCOME STRONG CONVECTIVE INHIBITION. THIS ACTIVITY APPEARS TO HAVE RECENTLY INCREASED IN COVERAGE AND INTENSITY AS IT MOVES INTO AN INSTABILITY AXIS WHERE PRONOUNCED SPEED AND DIRECTIONAL SHEAR WILL CONTINUE TO SUPPORT UPDRAFT ROTATION AND STORM PERSISTENCE. DIAGNOSTIC DATA CONTINUE TO SUGGEST THAT BOTH VERY LARGE HAIL AND ISOLATED TORNADOES WILL BE POSSIBLE WITH THESE CELLS AS THEY TRACK ACROSS PARTS OF SERN ND AND NWRN/NRN MN THIS EVENING. FARTHER SOUTH AND EAST...MSP SOUNDING DEPICTED PRONOUNCED WARM LAYER ABOVE 800 MB CONTRIBUTING TO SIGNIFICANT INHIBITION...WHICH LIKELY COVERS MUCH OF THE WARM SECTOR AHEAD OF THE FRONT. A CLUSTER OF POORLY ORGANIZED STORMS ON THE SRN FRINGE OF STRONGER DEEP LAYER SHEAR PERSISTS FROM NERN NEB INTO EXTREME SERN SD. THIS ACTIVITY INITIATED EARLIER ON THE APEX OF SURFACE THERMAL RIDGE AXIS/TROUGH WHERE DEEP MIXING IN VERY HOT AIR MASS WAS SUFFICIENT TO OVERCOME CONVECTIVE INHIBITION /SEE OAX EVENING RAOB/. MEANWHILE...ISOLATED STORM UPDRAFTS HAVE STRUGGLED TO TAKE ROOT ALONG THE FRONTAL WIND SHIFT OVER CNTRL/NERN SD. OVERNIGHT EVOLUTION OF CONVECTION ACROSS THESE AREAS...EWD ACROSS IA/SRN MN...REMAINS UNCERTAIN. CURRENT ACTIVITY SHOULD CONTINUE TO POSE A THREAT OF ISOLATED WIND AND HAIL. LATEST NAM-WRF AND RUC DEPICT DIFFERING SOLUTIONS WITH THE NAM-WRF DEVELOPING AN MCS ACROSS IA...AND RUC KEEPING STRONGER UVV AND QPF SIGNALS FARTHER NORTH...ACROSS MN. IT SEEMS POSSIBLE THAT A SEVERE MCS MAY DEVELOP ACROSS NRN IA/SRN MN LATER TONIGHT AS FRONTAL LIFT MOVES SEWD INTO VERY MOIST AND UNSTABLE AIR MASS...AND MASS TRANSPORT INTO THE REGION IS MAXIMIZED ON THE NOSE OF PLAINS LOW LEVEL JET. ...SOUTHEAST... POCKETS OF STRONG INSTABILITY REMAIN SITUATED AHEAD OF SCATTERED CLUSTERS OF PERSISTENT CONVECTION FROM LA EWD TO SC LATE THIS EVENING. CELL MERGERS AND LIFT ALONG COMPOSITE OUTFLOWS MAY BE SUFFICIENT FOR A FEW ROBUST UPDRAFTS...AND POSSIBLY LEAD TO NEW DEVELOPMENT...OVER THE NEXT COUPLE OF HOURS. ISOLATED WET DOWNBURSTS PRODUCING DAMAGING WINDS APPEAR TO BE THE MAIN HAZARD UNTIL BOUNDARY LAYER STABILIZES FURTHER. ..CARBIN.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 04:51:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 00:51:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060452 SWODY1 SPC AC 060450 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1150 PM CDT SAT AUG 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLAINS TO PARTS OF THE UPPER MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY/CNTRL APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX COASTAL PLAIN/SRN LA... ...SYNOPSIS... TYPICAL SUMMERTIME FLOW REGIME WILL CONTINUE THIS PERIOD WITH LARGE SUBTROPICAL RIDGE DOMINATING THE SRN 2/3RDS OF THE CONUS AND A BROAD BAND OF CYCLONIC FLOW SPREADING ESEWD FROM SCNTRL CANADA AND THE UPPER MS VALLEY...ACROSS THE GREAT LAKES...TO THE ST. LAWRENCE VALLEY/NRN NEW ENGLAND BY THE END OF THE PERIOD. A CLOSED LOW OFF THE CA COAST WILL BEGIN TO OPEN UP AND MOVE NEWD TOWARD THE NORTHWEST COAST TODAY AND TONIGHT AS DOWNSTREAM UPPER RIDGE BUILDS ACROSS THE NRN ROCKIES. LONG-LIVED SUBTROPICAL GYRE WILL MOVE ACROSS THE TX GULF COAST TODAY WHILE SMALLER SCALE WAVE MOVES WWD FROM THE FL STRAITS INTO THE CNTRL GULF. ...CNTRL PLAINS/MIDWEST... AS STRONGER HEIGHT FALLS ASSOCIATED WITH PROGRESSIVE IMPULSE OVER ONTARIO CONTINUE TO SPREAD EAST...TRAILING FRONT/WIND SHIFT...FROM WRN GREAT LAKES REGION SWWD TO IA/NEB...WILL EVENTUALLY WEAKEN ACROSS THESE AREAS WITH TIME. HOWEVER...RESIDUAL CLOUDS AND CONVECTION...COUPLED WITH PERSISTENT CONVERGENCE ALONG THE BOUNDARY...WILL ESTABLISH A ZONE OF ENHANCED MESOSCALE ASCENT FROM SRN WI WSWWD TO THE CNTRL HIGH PLAINS THIS AFTERNOON. STRONG HEATING AND DESTABILIZATION WITHIN THIS ZONE WILL LIKELY FUEL AFTERNOON AND EVENING TSTMS...A FEW OF WHICH COULD BE SEVERE. WEAK POST FRONTAL FLOW WITH SOME ELY/UPSLOPE COMPONENT WILL BE TOPPED BY 15-30KT WLY FLOW ALOFT AND RESULT IN MARGINALLY SUPPORTIVE DEEP LAYER SHEAR FOR UPDRAFT PERSISTENCE/ROTATION... AND PERHAPS SOME HAIL. IN ADDITION...DAMAGING OUTFLOW WINDS WILL BE POSSIBLE FROM STORMS DEVELOPING NEAR THE RESIDUAL FRONT AND MOVING INTO STRONGLY HEATED AND DEEPLY MIXED BOUNDARY LAYER FROM NEB/KS BORDER EWD ACROSS SRN IA/NRN MO. ...UPPER OH VALLEY/CNTRL APPALACHIANS... INCREASING WARM AIR AND MOISTURE ADVECTION IS FORECAST TO DEVELOP ON THE WRN PERIPHERY OF EAST COAST ANTICYCLONE AND MAY BE FURTHER ENHANCED/CHANNELED IN THE LOW LEVELS ALONG THE WRN SLOPES OF THE CNTRL APPALACHIANS. THIS PROCESS IS EXPECTED TO RESULT IN THE DEVELOPMENT OF STRONG INSTABILITY WITH HEATING OF THE DAY FROM THE TN VALLEY NEWD ACROSS THE UPPER OH VALLEY. ISOLATED TO SCATTERED PULSE STORMS WILL BE POSSIBLE ACROSS MUCH OF THE AREA GIVEN WEAKLY CAPPED AND INCREASINGLY UNSTABLE BOUNDARY LAYER. THE POTENTIAL FOR ORGANIZED MULTICELL STORMS WITH SEVERE HAIL AND WIND MAY EVOLVE OVER PARTS OF ERN KY/SRN OH WHERE MID LEVEL FLOW IS FORECAST TO STRENGTHEN DURING THE DAY. WEAK HEIGHT FALLS ASSOCIATED WITH THE GREAT LAKES TROUGH WILL ALSO BRUSH THIS REGION AND MAY PROMOTE GREATER STORM COVERAGE/SEVERE POTENTIAL. ...SERN TX/SRN LA... TROPICAL MOISTURE AND STRONG HEATING WILL RESULT IN NUMEROUS TSTMS DEVELOPING ACROSS THE GULF COAST AND TX COASTAL PLAIN TODAY. LARGE SCALE ASCENT AND BAND OF ENHANCED CYCLONIC FLOW AROUND LARGE NWWD MOVING MID/UPPER LOW MAY SUPPORT CLUSTERS OF MULTICELL STORMS PRODUCING WET DOWNBURSTS. ...NRN CA/SRN ORE... BELT OF 25-30KT SLY FLOW ON ERN EDGE OF OPENING MID LEVEL WAVE WILL ARRIVE ACROSS NRN CA/SRN ORE COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. THE INCREASE IN SHEAR MAY RESULT IN ISOLATED SEVERE STORMS WITH SOME HAIL/WIND POTENTIAL OVER THESE AREAS INTO THE EVENING HOURS. ..CARBIN/GUYER.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 12:44:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 08:44:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061244 SWODY1 SPC AC 061242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0742 AM CDT SUN AUG 06 2006 VALID 061300Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO THE UPPER MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE TX COASTAL PLAIN AND SRN LA... ...CNTRL PLAINS/MIDWEST... AS STRONGER HEIGHT FALLS ASSOCIATED WITH PROGRESSIVE IMPULSE OVER ONTARIO CONTINUE TO SPREAD EAST...TRAILING FRONT/WIND SHIFT...FROM WRN GREAT LAKES REGION SWWD TO IA/SERN NEB...WILL EVENTUALLY WEAKEN ACROSS THESE AREAS WITH TIME. HOWEVER...RESIDUAL CLOUDS AND CONVECTION...COUPLED WITH PERSISTENT CONVERGENCE ALONG THE BOUNDARY...WILL ESTABLISH A ZONE OF ENHANCED MESOSCALE ASCENT FROM SRN WI WSWWD TO THE CNTRL HIGH PLAINS THIS AFTERNOON. STRONG HEATING AND DESTABILIZATION WITHIN THIS ZONE WILL LIKELY FUEL AFTERNOON AND EVENING TSTMS...A FEW OF WHICH COULD BE SEVERE. WEAK POST FRONTAL FLOW WITH SOME ELY/UPSLOPE COMPONENT WILL BE TOPPED BY 15-30KT WLY FLOW ALOFT AND RESULT IN MARGINALLY SUPPORTIVE DEEP LAYER SHEAR FOR UPDRAFT PERSISTENCE/ROTATION...AND PERHAPS SOME HAIL. IN ADDITION...DAMAGING OUTFLOW WINDS WILL BE POSSIBLE FROM STORMS DEVELOPING NEAR THE RESIDUAL FRONT AND MOVING INTO STRONGLY HEATED AND DEEPLY MIXED BOUNDARY LAYER FROM NEB/KS BORDER EWD ACROSS SRN IA/NRN MO. ..SERN TX/SRN LA... TROPICAL MOISTURE AND STRONG HEATING WILL RESULT IN NUMEROUS TSTMS DEVELOPING ACROSS THE GULF COAST AND TX COASTAL PLAIN TODAY. LARGE SCALE ASCENT AND BAND OF ENHANCED CYCLONIC FLOW AROUND LARGE NWWD MOVING MID/UPPER LOW MAY SUPPORT CLUSTERS OF MULTICELL STORMS PRODUCING WET DOWNBURSTS. THE POTENTIAL FOR ISOLATED WATERSPOUTS AND POSSIBLY A BRIEF TORNADO SHOULD ALSO CONTINUE. ...UPPER OH VALLEY/CNTRL APPALACHIANS... INCREASING WARM AIR AND MOISTURE ADVECTION IS FORECAST TO DEVELOP ON THE WRN PERIPHERY OF EAST COAST ANTICYCLONE AND MAY BE FURTHER ENHANCED/CHANNELED IN THE LOW LEVELS ALONG THE WRN SLOPES OF THE CNTRL APPALACHIANS. THIS PROCESS IS EXPECTED TO RESULT IN THE DEVELOPMENT OF STRONG INSTABILITY WITH HEATING OF THE DAY FROM THE TN VALLEY NEWD ACROSS THE UPPER OH VALLEY. ISOLATED TO SCATTERED PULSE STORMS WILL BE POSSIBLE ACROSS MUCH OF THE AREA GIVEN WEAKLY CAPPED AND INCREASINGLY UNSTABLE BOUNDARY LAYER. WEAK HEIGHT FALLS ASSOCIATED WITH THE GREAT LAKES TROUGH WILL ALSO BRUSH THIS REGION AND MAY PROMOTE GREATER STORM COVERAGE/SEVERE POTENTIAL. OVERALL SEVERE THREAT APPEARS LIMITED...HOWEVER...AS RUC FORECAST AND OBSERVED SOUNDINGS THIS MORNING INDICATE RELATIVELY WEAK LAPSE RATES AND MARGINAL DEEP LAYER SHEAR. ...NRN CA/SRN ORE... BELT OF 25-30KT SLY FLOW ON ERN EDGE OF OPENING MID LEVEL WAVE WILL ARRIVE ACROSS NRN CA/SRN ORE COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. THE INCREASE IN SHEAR MAY RESULT IN ISOLATED SEVERE STORMS WITH SOME HAIL/WIND POTENTIAL OVER THESE AREAS INTO THE EVENING HOURS. ..EVANS/GUYER/CARBIN.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 16:37:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 12:37:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061636 SWODY1 SPC AC 061634 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CDT SUN AUG 06 2006 VALID 061630Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM NRN KS TO ERN IA.... ...CENTRAL PLAINS TO MID MS VALLEY THIS AFTERNOON... A SURFACE COLD FRONT...WHICH EXTENDED FROM NW WI TO SE MN/NW IA/SE NEB/NW KS AS OF 15Z...IS MOVING SLOWLY SEWD IN THE WAKE OF A PRONOUNCED SHORTWAVE TROUGH PROGRESSING EWD OVER ONTARIO. A BAND OF MID-UPPER 60S DEWPOINTS PRECEDES THE FRONT ACROSS WI/UPPER MI. HOWEVER...INSTABILITY SHOULD REMAIN RATHER LIMITED THIS AREA DUE TO CLOUDS AND POOR LAPSE RATES...AND FORCING FOR ASCENT WILL BE WEAK IN THE WAKE OF THE MORNING WAVE AND WELL S OF THE ONTARIO TROUGH. THUS...ANY SEVERE STORM THREAT SHOULD ALSO REMAIN MARGINAL THIS AREA. OVERNIGHT CONVECTION IS GRADUALLY WEAKENING OVER SE WI AND NRN IL. THESE STORMS ARE ASSOCIATED WITH A WEAK MID LEVEL SHORTWAVE TROUGH MOVING EWD OVER ERN IA/WI...THOUGH THE CONVECTION SHOULD CONTINUE TO WEAKEN AS IT MOVES INTO A REGION OF WEAK INSTABILITY. AN OUTFLOW BOUNDARY EXTENDS FROM NRN IL INTO CENTRAL IA...WITH A FEED OF UNDISTURBED WARM SECTOR AIR FROM ERN KS/MO INTO SRN IA. THE STRONGER INSTABILITY /MLCAPE VALUES OF 1500-2000 J/KG/ ARE EXPECTED ALONG THE OUTFLOW BOUNDARY AND FRONT FROM NRN KS INTO IA THIS AFTERNOON. THIS AREA REMAINS S OF THE STRONGER MID LEVEL WLYS...BUT VERTICAL SHEAR SHOULD BE SUFFICIENT FOR ORGANIZED MULTICELL CLUSTERS AND PERHAPS MARGINAL SUPERCELL TYPE STORMS. ISOLATED DAMAGING WINDS AND MARGINALLY SEVERE HAIL SHOULD BE THE MAIN SEVERE THREATS THIS AFTERNOON/EVENING. ...NW GULF COAST REGION... THE MID LEVEL TROUGH IN THE ELYS CONTINUES TO MOVE OVER LA/NW GULF TOWARD SE TX. REGIONAL 12Z SOUNDINGS SUGGEST THAT THE DOWNBURST POTENTIAL HAS BEEN REDUCED COMPARED TO THE PREVIOUS TWO DAYS ACROSS THE GULF COAST...GIVEN LESSER CAPE VALUES AND MODEST LOW-LEVEL LAPSE RATES. WHILE ISOLATED DAMAGING WINDS WILL STILL BE POSSIBLE...THE OVERALL SEVERE STORM THREAT APPEARS TOO MARGINAL TO WARRANT MAINTAINING A SLIGHT RISK. ..THOMPSON/TAYLOR.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 19:52:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 15:52:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061952 SWODY1 SPC AC 061950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SUN AUG 06 2006 VALID 062000Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS AND UPPER MIDWEST... ...CNTRL PLAINS/UPPER MIDWEST... A LARGE AREA OF UPPER-LEVEL HIGH PRESSURE CURRENTLY EXTENDS EWD FROM THE CNTRL PLAINS ACROSS THE MID MS VALLEY. AT THE SFC...A COLD FRONT EXISTS FROM NRN KS EXTENDING NEWD INTO CNTRL IA. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE 60S AND LOWER 70S F RESULTING IN MODERATE TO STRONG INSTABILITY. THUNDERSTORMS ARE INCREASING IN COVERAGE ACROSS NRN KS AND SERN NEB AND THIS TREND SHOULD CONTINUE THROUGH THE LATE AFTERNOON WITH CONVECTION SPREADING ENEWD INTO SRN IA. ALTHOUGH OBJECTIVE ANALYSIS SHOWS SHEAR PROFILES MARGINAL FOR SUPERCELLS...VERTICAL SHEAR APPEARS SUFFICIENT FOR SEVERE MULTICELLS. LAPSE RATES ARE VERY STEEP EXCEEDING 8.0 C/KM ACROSS MUCH OF THE WARM SECTOR WHICH COMBINED WITH THE STRONG INSTABILITY WILL MAKE HAIL AND ISOLATED WIND DAMAGE A POSSIBILITY WITH THE STRONGER CELLS THIS AFTERNOON. ...EAST TX/WRN LA/ERN OK/WRN OZARKS... LATEST WATER VAPOR IMAGERY SHOWS A WWD MOVING WAVE OVER THE NWRN GULF OF MEXICO. NUMEROUS THUNDERSTORMS ARE ONGOING ACROSS THE REGION LOCATED MAINLY ALONG BANDS OF LARGE-SCALE ASCENT ASSOCIATED WITH THE WAVE. OBJECTIVE ANALYSIS CURRENTLY SHOWS MODERATE INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES ACROSS MUCH OF THE REGION. THIS SHOULD BE SUFFICIENT FOR STRONG MULTICELL AND/OR PULSE THUNDERSTORMS CAPABLE OF STRONG WIND GUSTS THIS AFTERNOON. ..BROYLES.. 08/06/2006  From swody1 at goshenarc.org Mon Aug 7 00:40:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 20:40:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070040 SWODY1 SPC AC 070038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT SUN AUG 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MO RIVER VALLEY... MASS OF DEEP CONVECTION PRECEDES SYNOPTIC FRONTAL ZONE FROM ERN NEB/SWRN IA TO NERN KS AND NWRN MO THIS EVENING. COLD POOL FROM THIS CONVECTION HAS SPREAD OUT TO THE SOUTH AND EAST AND APPEARS TO BE PROMOTING ADDITIONAL TSTM DEVELOPMENT IN HOT AND STRONGLY UNSTABLE AIR MASS. THREAT FOR ISOLATED HAIL AND SCATTERED DAMAGING DOWNBURST WINDS WILL PERSIST FOR AT LEAST A COUPLE MORE HOURS ACROSS THE REGION UNTIL BOUNDARY LAYER STABILIZES FURTHER. ...CNTRL HIGH PLAINS... ROBUST STORMS CONTINUE TO DEVELOP IN REGION OF POST-OUTFLOW ASCENT OVER NWRN KS...AS WELL AS IN POST-FRONTAL UPSLOPE ENVIRONMENT FROM ERN CO TO NERN WY. DEEP LAYER ASCENT ACROSS THIS REGION MAY BE FURTHER ENHANCED BY A WEAK SHORT WAVE TROUGH SPREADING EAST ACROSS NERN CO. GIVEN MODEST INSTABILITY AND SHEAR...ISOLATED SEVERE STORMS WITH WIND AND HAIL COULD PERSIST ACROSS THESE AREAS THIS EVENING. ...SERN TX... CLUSTERS OF TSTMS WILL CONTINUE WITHIN VERY MOIST AND MODERATELY UNSTABLE REGIME ACROSS THE UPPER TX GULF COAST AND COASTAL PLAIN. THIS CONVECTION APPEARS TO BE AIDED BY SLOW MOVING MID/UPPER WAVE DEVELOPING NWWD FROM THE GULF. DEEP LAYER CYCLONIC FLOW AND LIFT FROM THE UPPER WAVE MAY SUSTAIN MORE WIDESPREAD DEEP CONVECTION OVER THE REGION INTO THE NIGHT WITH SOME POTENTIAL FOR ISOLATED WET DOWNBURSTS. ...SRN CASCADES... STRONG TO ISOLATED SEVERE STORMS HAVE ERUPTED OVER THE SISKIYOU MOUNTAINS AND SRN CASCADES LATE THIS AFTERNOON. THIS OROGRAPHICALLY FORCED ACTIVITY APPEARS TO BE FURTHER SUPPORTED BY BROADLY DIFFLUENT MID LEVEL FLOW AHEAD OF UPPER LOW EDGING NEWD TOWARD THE NRN CA COAST. DESPITE LIMITED MOISTURE...STEEP LAPSE RATE ENVIRONMENT AND SUFFICIENT FORCING SHOULD CONTRIBUTE TO A CONTINUED POTENTIAL FOR A HAIL/WIND EVENT OR TWO OVER THE NEXT FEW HOURS. ..CARBIN.. 08/07/2006  From swody1 at goshenarc.org Sat Aug 12 00:57:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 11 Aug 2006 20:57:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120057 SWODY1 SPC AC 120056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT FRI AUG 11 2006 VALID 120100Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN/CNTRL PLAINS... ...NRN/CNTRL PLAINS... SCATTERED SUPERCELLS HAVE INCREASED IN AREAL COVERAGE AHEAD OF UPPER TROUGH FROM SERN SASKATCHEWAN...SWD INTO NWRN SD...WITH MORE ISOLATED ACTIVITY OVER NCNTRL NEB/SCNTRL SD. EARLY EVENING SOUNDINGS AND DIAGNOSTIC DATA EXHIBIT A DEEP MIXED BOUNDARY LAYER ACROSS THE HIGH PLAINS TO THE WEST OF THE ONGOING CONVECTION...THROUGH 550MB AT RAP...WITH SIGNIFICANT INSTABILITY DOWNSTREAM ACROSS THE MOIST SECTOR...COINCIDENT WITH THUNDERSTORM ACTIVITY. WITH LOSS OF DAYTIME HEATING IT APPEARS BOUNDARY LAYER WILL DECOUPLE AS CAP BEGINS TO STRENGTHEN THIS EVENING. LLJ SHOULD PROVE INSTRUMENTAL IN MAINTAINING OVERNIGHT CONVECTION...ESPECIALLY ACROSS ND. GIVEN THE POSITION OF THE UPPER TROUGH...WELL UPSTREAM OVER THE NRN ROCKIES...IT APPEARS LOW LEVEL WARM ADVECTION WILL AID CONVECTIVE CLUSTERING AND POSSIBLE MCS DEVELOPMENT THAT SHOULD SHIFT EWD TOWARD THE RED RIVER REGION OF NWRN MN BY THE END OF THE PERIOD. LARGE HAIL AND DAMAGING WINDS MAY ACCOMPANY THESE STORMS THROUGH THE OVERNIGHT HOURS. FARTHER SOUTH...LBS SOUNDING AT 00Z DISPLAYED A SIGNIFICANT AMOUNT OF INSTABILITY THIS EVENING...MLCAPE IN EXCESS OF 2200 J/KG. SEVERE SUPERCELL STRUCTURES THAT ARE ONGOING ACROSS THIS REGION SHOULD STRUGGLE TO SPREAD TOO FAR DOWNSTREAM GIVEN THE LACK OF LARGE SCALE SUPPORT...AND EXPECTED FOCUS OF THE LLJ INTO THE NRN DAKOTAS. WITH LOSS OF HEATING CNTRL PLAINS CONVECTION SHOULD GRADUALLY BECOME ELEVATED AND BACKBUILD INTO STEEPER HEAT PLUME BEFORE WEAKENING LATE THIS EVENING. ..DARROW.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 05:43:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 01:43:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120544 SWODY1 SPC AC 120542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1242 AM CDT SAT AUG 12 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN/CNTRL PLAINS INTO THE UPPER MS VALLEY... HEIGHT FALLS ACROSS THE NRN ROCKIES WILL FLATTEN THE RIDGE IN PLACE ACROSS THE NRN PLAINS LATER TODAY. AS UPPER TROUGH SHIFTS EWD ACROSS ID/MT IT SHOULD FORCE A WEAK DISTURBANCE LOCATED OVER UT NEWD INTO SD BY 00Z...ENHANCING DEEP LAYER SHEAR ALONG AN ELONGATED ZONE OF TIGHTENING LOW LEVEL CONFLUENCE FROM THE NEB PANHANDLE INTO ERN ND/NWRN MN. THIS LOW LEVEL BOUNDARY WILL SERVE AS THE FOCUS FOR EPISODIC CONVECTIVE EVENTS DURING THE DAY1 PERIOD. LATEST THINKING IS SCATTERED THUNDERSTORM ACTIVITY WILL BE ONGOING EARLY IN THE PERIOD WITHIN WARM ADVECTION ZONE ACROSS THE ERN DAKOTAS/MN AS LLJ FEEDS ONGOING ELEVATED CONVECTION. ALTHOUGH THIS ACTIVITY MAY PRODUCE ISOLATED HAIL OR GUSTY WINDS...IT APPEARS STRONGER ACTIVITY WILL EVOLVE LATER IN THE DAY AS BOUNDARY LAYER HEATS ALONG WIND SHIFT. FAVORABLE LOW LEVEL TRAJECTORIES WILL MAINTAIN MORE THAN SUFFICIENT MOISTURE ACROSS THE NRN/CNTRL PLAINS FOR RENEWED THUNDERSTORM DEVELOPMENT BY 21Z...ESPECIALLY GIVEN THE ADDED ASCENT AHEAD OF EJECTING CNTRL ROCKIES SHORTWAVE TROUGH. WITH STRENGTHENING VERTICAL SHEAR PROFILES IT APPEARS SUPERCELL STRUCTURES ARE POSSIBLE...ESPECIALLY EARLY IN THE AFTERNOON CONVECTIVE CYCLE. THE ENTIRE FRONTAL ZONE MAY CONVECT QUICKLY AND EXPAND LINEARLY NEWD FROM CO INTO MN BY 00Z. LATEST FORECAST SOUNDINGS SUGGEST AN ENHANCED SUPERCELL THREAT MAY EXIST AHEAD OF WEAK SFC LOW FROM ERN SD INTO WCNTRL MN BETWEEN 21Z-03Z. THIS SFC FEATURE APPEARS CORRELATED WITH EJECTING SHORTWAVE WHICH COULD RESULT IN A FEW TORNADOES BEFORE STORM MERGERS AND MULTI-CELL CLUSTERS BECOME DOMINATE. OTHERWISE...SUFFICIENT MOISTURE/INSTABILITY WILL LINGER WITHIN POST FRONTAL REGIME ACROSS THE NRN PLAINS FOR AN ELEVATED ANA-TYPE CONVECTIVE EVENT TO DEVELOP ACROSS PORTIONS OF SD/ND LATER IN THE EVENING HOURS...AIDED BY MAIN UPPER TROUGH THAT APPROACHES AFTER DARK. LARGE HAIL SHOULD BE THE PRIMARY SEVERE RISK ACROSS THE SLIGHT RISK REGION. ...ELSEWHERE... STATIONARY...DECAYING FRONTAL ZONE FROM GA...WWD ACROSS THE NRN GULF STATES INTO THE SRN PLAINS WILL FOCUS CONVECTION AGAIN TODAY. VERY MOIST PROFILES AND WEAK TROPOSPHERIC FLOW MAY ENHANCE LOCAL WET MICROBURSTS...HOWEVER ORGANIZED DAMAGING WIND THREAT WILL PROVE TOO DIFFICULT TO PREDICT THIS EARLY IN THE CONVECTIVE PERIOD. ..DARROW/TAYLOR.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 12:37:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 08:37:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121237 SWODY1 SPC AC 121236 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 AM CDT SAT AUG 12 2006 VALID 121300Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHEAST CO ACROSS MUCH OF THE NORTHERN PLAINS INTO MN... LARGE UPPER RIDGE WILL REMAIN OVER THE SOUTHERN HALF OF THE NATION TODAY...WHILE STRONG TROUGH ROTATES EASTWARD ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS. UPPER FORCING WILL OVERSPREAD A MOIST AND VERY UNSTABLE AIRMASS ACROSS THE DAKOTAS/MN/NEB THIS AFTERNOON...POTENTIALLY SETTING THE STAGE FOR A MORE ORGANIZED SEVERE THUNDERSTORM EVENT FROM EASTERN SD INTO WESTERN MN. ...NORTHERN PLAINS... SURFACE COLD FRONT IS ANALYZED THIS MORNING FROM CENTRAL ND INTO EASTERN WY. THIS BOUNDARY WILL MOVE SLOWLY EASTWARD ACROSS THE DAKOTAS THIS AFTERNOON...WHILE SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT MAINTAIN AMPLE MOISTURE/INSTABILITY. SURFACE TEMPERATURES IN THE 90S AND DEWPOINTS NEAR 70F WILL YIELD AFTERNOON MLCAPE VALUES OVER 3000 J/KG. CAPPING INVERSION WILL BE QUITE STRONG ACROSS THIS REGION THROUGH THE MORNING...BUT IS EXPECTED TO WEAKEN RAPIDLY DURING THE AFTERNOON AS UPPER TROUGH APPROACHES. BY 21Z...RUC/NAM FORECAST SOUNDINGS INDICATE AN ENVIRONMENT QUITE FAVORABLE FOR SUPERCELL STORMS CAPABLE OF VERY LARGE HAIL AND DAMAGING WINDS. LCL HEIGHTS MAY BE A LITTLE HIGH...BUT OTHERWISE LOW LEVEL SHEAR MAY ALSO BE SUFFICIENT FOR ISOLATED TORNADOES. ACTIVITY SHOULD SPREAD INTO MN DURING THE EVENING WITH A CONTINUED SEVERE THREAT. ...NEB/CO... FULL SUNSHINE IS EXPECTED FROM EASTERN CO INTO PARTS OF NEB TODAY...ALLOWING AIR MASS TO BECOME HOT AND MODERATELY UNSTABLE. FORECAST SOUNDINGS SHOW A DEEP...MIXED BOUNDARY LAYER CONDUCIVE TO LOCALLY DAMAGING WINDS IN STRONGER CELLS. ACTIVITY IS EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF CENTRAL CO AND SPREAD NORTHEASTWARD INTO WESTERN NEB BEFORE WEAKENING TONIGHT. MARGINAL DEEP LAYER VERTICAL SHEAR SUGGESTS STORMS WILL BE RATHER DISORGANIZED AND LIMITED. ...SOUTHEAST... ANOTHER DAY OF HOT...HUMID CONDITIONS ARE EXPECTED TODAY ALONG AND SOUTH OF MAIN FRONTAL BOUNDARY FROM EAST TX INTO GA/SC. THESE STORMS ARE LIKELY TO BE DISORGANIZED AND CAPABLE OF ONLY BRIEF SEVERE WINDS. ACTIVITY SHOULD DIMINISH RAPIDLY AFTER MIDNIGHT. ..HART/TAYLOR.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 16:14:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 12:14:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121614 SWODY1 SPC AC 121612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT SAT AUG 12 2006 VALID 121630Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN CO ACROSS NRN PLAINS INTO MN... ...SYNOPSIS... WHILE RIDGING PREVAILS S OF 40N THE LARGE SCALE TROUGH WRN CANADA INTO PAC NW WILL SHIFT EWD ACROSS NRN ROCKIES INTO NRN HIGH PLAINS BY 12Z SUN. S/WV ENERGY ROTATING THRU THE TROUGH CURRENTLY CROSSING ID AND WRN MT WILL REACH HIGH PLAINS LATE TONIGHT. PRECEEDING THE TROUGH A PLUME OF DEEP MONSOON MOISTURE IS SPREADING NEWD FROM CENTRAL ROCKIES ACROSS THE NRN PLAINS TODAY. AT THE SURFACE COLD FRONT CURRENTLY ACROSS WRN DAKOTAS AND THEN WSWWD INTO SWRN WY AND NRN UT WILL ONLY SHIFT SLOWLY EWD THRU THE AFTERNOON AS UPPER SUPPORT STILL WELL TO THE W. 30-40KT SLY LOW LEVEL JET E OF FRONT CONTINUES TO PROVIDE A MOIST AND POTENTIALLY VERY UNSTABLE AIR MASS NWD TO CANADIAN BORDER. ...NRN PLAINS... THE COMBINATION OF WARM MID LEVEL TEMPERATURES AND THE MONSOON PLUME OF MOISTURE WILL DELAY INITIATION OF SURFACE BASED SEVERE THUNDERSTORMS UNTIL LATER THIS AFTERNOON/EVENING MUCH OF NRN PLAINS AREA ALONG AND E OF COLD FRONT. SUFFICIENT ELEVATED INSTABILITY AND SHEAR FOR MORE ISOLATED LARGE HAIL THIS AFTERNOON PRIOR TO THE EXPECTED MORE INTENSE DEVELOPMENT ONCE CAP HAS ERODED. HOWEVER WITH DEWPOINTS MID 60S TO 70 F AND POTENTIAL FOR SURFACE TEMPERATURES RISING THRU THE 90S F...CAP SHOULD WEAKEN SUFFICIENTLY FOR SEVERE THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF COLD FRONT CENTRAL ND/SD BY LATER THIS AFTERNOON. WITH DEEP LAYER SHEAR OF 30-40KT COUPLED WITH MLCAPES INCREASING TO 2500...SUPERCELLS ARE LIKELY. VERY LARGE HAIL WILL BE PRIMARY THREAT WITH ANY SUPERCELL...HOWEVER SUFFICIENT LOW LCL/S ERN DAKOTAS/WRN MN BY LATE THIS AFTERNOON FOR POSSIBLE TORNADOES AS WELL. ...NERN CO INTO NEB... STRONG HEATING AND WEAKER SHEAR THIS AREA WILL RESULT IN A DEEPLY MIXED BOUNDARY LAYER BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGH TERRAIN AND IN CONVERGENCE ALONG COLD FRONT...THEN PROPAGATE E/NE THRU THE EVENING. PRIMARY THREAT GIVEN THE EXPECTED STEEP LAPSE RATES AND HIGH BASES WILL BE DAMAGING WINDS. ANY SEVERE HAIL WILL BE ASSOCIATED WITH ISOLATED SUPERCELLS THAT COULD FORM PRIOR TO NIGHTFALL. ..HALES/JEWELL.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 20:00:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 16:00:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 122001 SWODY1 SPC AC 121959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT SAT AUG 12 2006 VALID 122000Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/NRN PLAINS TO THE UPPER MS VLY... ...NRN/CNTRL PLAINS TO THE UPPER MS VLY... TSTMS CONTINUE TO GRADUALLY INTENSIFY ALONG/AHEAD OF A PRE-FRONTAL TROUGH COINCIDENT WITH A LOW-LEVEL THERMAL RIDGE FROM CNTRL SD SWD INTO NERN CO THIS AFTN. 2-6KM SHEAR VECTORS HAVE HAD A BACKING TENDENCY AHEAD OF THE DIGGING PAC NW TROUGH...NOW ALIGNED PARALLEL TO THE INITIATING BOUNDARY. THIS SUGGESTS THAT STORMS WILL EVOLVE PRIMARILY INTO LINE SEGMENTS. VERTICAL SHEAR WAS STRONGEST ACROSS THE INTERNATIONAL BORDER AND ACROSS THE NRN HIGH PLAINS...BUT MARGINALLY SUFFICIENT FOR PERHAPS A BRIEF SUPERCELL. PRESENT INDICATIONS ARE THAT THE STORMS WILL SLOWLY INTENSIFY ACROSS CNTRL/ERN SD SWD INTO CNTRL NEB THROUGH THE EVENING OWING TO STEEP LOW-LEVEL LAPSE RATES. H7-H5 LAPSE RATES HAVE BEEN TEMPERED BY INFLUX OF MONSOONAL MOISTURE ALOFT ON THE SUB-TROPICAL CONVEYOR AND SHOULD LIMIT HAIL SIZE TO LESS THAN 2 INCHES. DAMAGING WINDS WILL BE A THREAT AS STORMS DEVELOP INTO SMALL SCALE BOWS. FURTHERMORE...THOUGH STORM EVOLUTION INTO A MORE LINEAR MODE WILL TEND TO LIMIT THREAT FOR SUSTAINED LOW-LEVEL ROTATION...ISOLD TORNADOES ARE PSBL ACROSS THE ERN DAKS/WRN MN WHERE THE BOUNDARY LAYER FLOW REMAINS BACKED AHEAD OF A 1003 MB SFC-LOW OVER CNTRL SD. HERE...LCLS ARE LOWER OWING TO SLIGHTLY COOLER TEMPERATURES AND AMPLY MOIST BOUNDARY LAYER. ACTIVITY WILL GRADUALLY SPREAD ENEWD INTO ERN SD...WRN MN AND NERN NEB OVERNIGHT WITH PERHAPS DAMAGING WINDS. FARTHER N...GLANCING INFLUENCE OF A LEAD MID-LEVEL SHORTWAVE TROUGH MOVING INTO SRN MANITOBA HAS CONTRIBUTED TO A GRADUAL INCREASE IN ELEVATED TSTMS ALONG/N OF THE PRIMARY COLD FRONT FROM NWRN ONTARIO...SERN MANITOBA INTO CNTRL ND. THIS REGION IS SITUATED JUST N OF THE SUB-TROPICAL MOIST PLUME AND MID-LEVEL TEMPERATURES ARE NOT AS WARM AS FARTHER S. CLOUDS DOWNSTREAM FROM THE ACTIVITY WILL TEND TO LIMIT SFC-BASED EVOLUTION...BUT ACTIVITY WILL LIKELY BUILD SWWD ALONG THE FRONT TOWARD SWRN ND LATER THIS AFTN. LARGE HAIL WILL BE THE PRIMARY THREAT WITH THIS ACTIVITY AS IT MOVES ENEWD INTO FAR NWRN MN/LAKE OF THE WOODS LATER THIS EVENING/OVERNIGHT. ...NRN/CNTRL ROCKIES/HIGH PLAINS... PRIMARY TROUGH AXIS NOW OVER ERN ORE AND ID WILL EJECT ENEWD INTO THE NRN/CNTRL HIGH PLAINS TONIGHT. TSTMS WILL BE INCREASING THIS EVENING ACROSS PORTIONS OF SRN MT AND WY IN ADVANCE OF THIS SYSTEM. ACTIVITY WILL MOVE NEWD ONTO THE ADJACENT HIGH PLAINS OVERNIGHT. LOW-LEVEL MOISTURE WILL BE SOMEWHAT LIMITED...BUT LARGE TEMP/DEW POINT SPREADS AND COLDER AIR ALOFT FILTERING INTO THE REGION MAY SUPPORT ISOLD GUSTY WINDS/HAIL. ..RACY.. 08/12/2006  From swody1 at goshenarc.org Sun Aug 13 00:55:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 20:55:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130055 SWODY1 SPC AC 130053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT SAT AUG 12 2006 VALID 130100Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/NRN PLAINS TO THE UPPER MS VALLEY... LARGE SCALE ASCENT APPEARS TO BE OVERSPREADING WRN EDGE OF DEEP MOIST PLUME IN PLACE ACROSS THE CNTRL/NRN HIGH PLAINS...PER RECENT EXPANDING MID LEVEL CLOUDINESS FROM NERN CO INTO SWRN SD. ADDITIONALLY...A BROKEN LINE OF THUNDERSTORMS HAS FORMED AHEAD OF MAIN SHORTWAVE FROM SERN MT INTO NWRN CO COINCIDENT WITH INCREASING ZONE OF ASCENT...PRODUCING ISOLATED SEVERE WIND GUSTS AT TIMES OVER THE HIGHER TERRAIN OF WY. WITH TIME...UPDRAFTS WILL INTERACT WITH MOIST BOUNDARY LAYER DOWNSTREAM WHICH MAY ALLOW FOR AN EXPANDING LINE OF THUNDERSTORMS FROM NWRN NEB INTO WRN SD/SCNTRL ND ALONG MAIN FRONTAL ZONE. HAIL AND GUSTY WINDS SHOULD ACCOMPANY THIS ACTIVITY AS IT SPREADS EWD DURING THE OVERNIGHT HOURS. DOWNSTREAM...AN ELONGATED MCS HAS EVOLVED FROM ERN SD INTO WCNTRL MN WITHIN DEEP MID-HIGH LEVEL MOIST PLUME THAT EXTENDS INTO LOW LATITUDE REGIONS OF THE SWRN U.S./NWRN MEXICO. THIS ACTIVITY IS SHIFTING SLOWLY EWD AHEAD OF LEAD SPEED MAX/SHORTWAVE THAT EJECTED ACROSS THE CNTRL ROCKIES EARLY THIS MORNING. LAPSE RATES ARE NOT PARTICULARLY STEEP ACROSS THIS REGION...WITH SUBSTANTIAL INHIBITION NOTED AT BOTH MPX AND OMA ON 00Z SOUNDINGS THIS EVENING. ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS STORM ROTATION...CURRENT STORM MODE WOULD SUGGEST ACTIVITY WILL MAINTAIN ITS MCS-TYPE CHARACTER AS IT SPREADS INTO SWRN PORTIONS OF MN. ..DARROW.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 05:52:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 01:52:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130552 SWODY1 SPC AC 130551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT SUN AUG 13 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES TO THE CENTRAL PLAINS... PRECIPITABLE WATER VALUES WILL REMAIN HIGH ACROSS THE MID SECTION OF THE U.S. SUNDAY AIDED BY MOIST MID-HIGH LEVEL TRAJECTORIES ACROSS THE SWRN U.S. INTO THE CNTRL PLAINS...WHILE SELY CONFLUENT BOUNDARY LAYER FLOW PERSISTS ALONG WRN EDGE OF OH VALLEY ANTICYCLONE. THIS MOIST REGIME WILL UNDOUBTEDLY PROVIDE SUFFICIENT INSTABILITY FOR RENEWED DAYTIME CONVECTION AHEAD OF ADVANCING COLD FRONT FROM THE SRN/CNTRL ROCKIES INTO THE GREAT LAKES REGION. EARLY MORNING WATER VAPOR IMAGERY IS NOT PARTICULARLY HELPFUL DEPICTING POTENTIAL DISTURBANCES EMBEDDED WITHIN TROPICAL CONNECTION FROM THE LOWER LATITUDES IN THE SWRN U.S. AS A RESULT...DAYTIME HEATING SHOULD PROVE INSTRUMENTAL IN POTENTIAL SEVERE DEVELOPMENT. LATE EVENING MODEL GUIDANCE SUGGEST AN AXIS OF STEEP LOW LEVEL LAPSE RATES WILL DEVELOP/SPREAD NEWD AHEAD OF SFC BOUNDARY ACROSS KS INTO WRN IA BY EARLY AFTERNOON. THIS SHOULD ENHANCE INSTABILITY ALONG SRN FRINGE OF STRONGER WLY FLOW/ZONE OF MID LEVEL HEIGHT FALLS IN ADVANCE OF NRN PLAINS TROUGH. ALTHOUGH SCATTERED THUNDERSTORMS MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ALONG FRONTAL ZONE...IT APPEARS MUCH OF THIS ACTIVITY MAY ACTUALLY BE POST WIND SHIFT. MOIST BOUNDARY LAYER CONVECTION SHOULD EVOLVE BY 20Z ALONG/AHEAD OF COLD FRONT...SHIFTING EWD INTO THE UPPER GREAT LAKES BY EARLY EVENING...ARCING SWWD INTO KS WHERE VERTICAL SHEAR WILL BE QUITE WEAK. FORECAST SOUNDINGS FOR THE MID MS VALLEY SUGGEST SUPERCELLS ARE POSSIBLE EARLY IN THE CONVECTIVE MODE...THEN LIKELY MATURE INTO FORCED BANDS OF STRONG/SEVERE CONVECTION THAT MAY GENERATE LOCALLY DAMAGING WINDS AS THEY MOVE DOWNSTREAM DURING THE EVENING HOURS. ...ELSEWHERE... DECAYING FRONTAL ZONE FROM THE SERN U.S. INTO THE SRN PLAINS WILL ONCE AGAIN AID ISOLATED-SCATTERED THUNDERSTORM DEVELOPMENT BY MID AFTERNOON. ASIDE FROM LOCALLY STRONG WINDS AND HEAVY RAIN THIS ACTIVITY SHOULD REMAIN RATHER BENIGN. ..DARROW/TAYLOR.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 12:48:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 08:48:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131248 SWODY1 SPC AC 131247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 AM CDT SUN AUG 13 2006 VALID 131300Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN KS/NEB INTO THE WESTERN GREAT LAKES REGION... ...MN/IA/WI/MI... MORNING WATER VAPOR IMAGERY SHOWS UPPER TROUGH MOVING ACROSS EASTERN MT/WY INTO THE NORTHERN PLAINS. AHEAD OF THIS TROUGH...WEAKER EMBEDDED FEATURES ARE INDICATED BY MODEL GUIDANCE OVER PARTS OF SD/NEB...ALTHOUGH THEY ARE HARDER TO IDENTIFY IN SATELLITE IMAGERY. THUNDERSTORMS HAVE PERSISTED OVERNIGHT AHEAD OF THESE FEATURES... RESULTING IN WIDESPREAD CLOUDS FROM SD/NEB/KS INTO MN/IA. THIS SHOULD LIMIT DAYTIME HEATING AND DESTABILIZATION ACROSS THE MIDWEST TODAY. AFTERNOON MAX TEMPERATURES IN THE LOW/MID 80S...COUPLED WITH SURFACE DEWPOINTS IN THE 60S...WILL YIELD MLCAPE VALUES OF 1000-1500 J/KG FROM MN/IA EASTWARD INTO THE WESTERN GREAT LAKES. DESPITE ONLY MODERATE INSTABILITY...VERTICAL SHEAR PROFILES WILL BE QUITE STRONG AS SOUTHERN FRINGE OF STRONG UPPER LEVEL JET OVERSPREADS REGION. THUNDERSTORMS ARE LIKELY TO INTENSIFY THIS AFTERNOON OVER MN/IA AHEAD OF SURFACE LOW/COLD FRONT...WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS IN STRONGER CELLS. THIS ACTIVITY WILL LIKELY DEVELOP EASTWARD ACROSS PARTS OF WI AND UPPER MI BEFORE WEAKENING THIS EVENING. ...EASTERN NEB/KS/NORTHERN MO... STRONGER DAYTIME HEATING IS ANTICIPATED SOUTH AND WEST OF AFOREMENTIONED AREA...WITH TEMPERATURES LIKELY TO CLIMB WELL INTO THE 90S FROM EASTERN NEB INTO PARTS OF KS/MO. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG COLD FRONT AS IT MOVES INTO REGION THIS AFTERNOON/EVENING. MID LEVEL WIND FIELDS AND VERTICAL SHEAR PROFILES WILL BE MUCH WEAKER IN THIS AREA THAN FARTHER NORTHEAST. HOWEVER...DEGREE OF INSTABILITY AND DEEP-MIXED BOUNDARY LAYER WILL PROMOTE A RISK OF DAMAGING WINDS IN STRONGER CELLS. ..HART/TAYLOR.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 15:58:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 11:58:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131559 SWODY1 SPC AC 131557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1057 AM CDT SUN AUG 13 2006 VALID 131630Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS/ERN NEB ACROSS IA INTO SRN MN/SWRN WI... ...KS/ERN NEB ACROSS IA INTO SRN MN/SWRN WI... A RATHER VIGOROUS S/WV TROUGH WILL BE CROSSING THE NRN PLAINS THIS AFTERNOON...REACHING THE UPPER GREAT LAKES BY 12Z MON. SWLY FLOW AHEAD OF TROUGH CONTINUES TO DIRECT MONSOONAL PLUME OF MOIST AIR NEWD ACROSS PLAINS INTO UPPER MS VALLEY. COLD FRONT CURRENTLY MOVING EWD EXTENDS FROM CENTRAL DAKOTAS/NEB INTO NERN CO. A SURFACE TROUGH PRECEDES THE FRONT ACROSS WRN KS TO NERN NM WITH WARM AND ONLY MODESTLY STEEP MID LEVEL LAPSE RATES IN ADVANCE OF THE COLD FRONT THAT IS MOVING EWD ACROSS CENTRAL DAKOTAS/NEB TODAY...SEVERE THUNDERSTORMS WILL REQUIRE STRONG SURFACE HEATING FOR INITIATION. BASED ON CURRENT TEMP AND CLOUD COVER TRENDS...HEATING WILL BE SUFFICIENT FOR DEVELOPMENT OF SURFACE BASED THUNDERSTORMS AHEAD OF COLD FRONT AND THE SURFACE TROUGH BY MID AFTERNOON. ADDITIONALLY SURFACE TEMPERATURES WILL LIKELY REACH LOW 90S INTO SRN IA WHERE A MORE FAVORABLE SHEAR ENVIRONMENT WILL BE IN PLACE. MLCAPES AOA 2000 J/KG FROM SRN IA SWWD INTO KS WILL SUPPORT DEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS BY MID AFTERNOON. GENERALLY SHEAR OF 20KT OR LESS IN KS WILL FAVOR PULSE/MULTICELLULAR ACTIVITY WITH DOWNBURSTS AND A MARGINALLY SEVERE HAIL THREAT. FURTHER NE ACROSS IA...SHEAR OF 30-40KT WILL CONDITIONALLY SUPPORT SUPERCELLS...PROVIDED SUFFICIENT HEATING/INSTABILITY DEVELOPS. MODELS INDICATE A GOOD MCS SIGNAL BY LATER THIS AFTERNOON/EVENING ACROSS NRN/CENTRAL IA WHICH WOULD LEAD TO A GREATER WIND DAMAGE POTENTIAL. AGAIN AMOUNT OF SURFACE HEATING WILL BE THE CAVEAT AS TO AMOUNT OF SEVERE POTENTIAL AS THE STRONG UVVS WITH THE S/WV TROUGH PASS FURTHER N ACROSS MN INTO UPPER GREAT LAKES WHERE THERMODYNAMICS ARE VERY LIMITED. ..HALES/JEWELL.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 19:52:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 15:52:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131952 SWODY1 SPC AC 131950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SUN AUG 13 2006 VALID 132000Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY SWWD INTO THE CNTRL PLAINS... ...UPPER MS VLY SWD INTO THE CNTRL PLAINS... 19Z SFC ANALYSIS PLACES A TROUGH FROM CNTRL IA SWWD TO A HEAT LOW VCNTY KTOP THEN SWWD INTO WRN KS. A 1010 MB LOW WAS SITUATED VCNTY KFSD WITH A N-S COLD FRONT FROM NCNTRL MN SWWD THROUGH THE LOW TO ECNTRL CO. BOUNDARY LAYER HEATING HAS BEEN STRONGEST AHEAD OF THE PRE-FRONTAL TROUGH FROM SCNTRL IA SWWD ACROSS NWRN MO INTO KS WHERE TEMPERATURES HAVE RISEN TO AOA 90 DEG F AND DEW POINTS HAVE REMAINED 70-75 DEG F. MAJORITY OF THE LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE UPPER TROUGH WAS PASSING WELL N OF THE MOST UNSTABLE WARM SECTOR. THUS... TSTMS WILL BE DRIVEN MOSTLY BY THERMODYNAMIC PROCESSES. THIS SHOULD CONFINE THE MOST VIGOROUS TSTM DEVELOPMENT ALONG THE SERN EDGE OF CURRENT CONVECTION...NAMELY FROM SCNTRL IA SWWD INTO EXTREME SERN NEB...NWRN MO AND NRN/CNTRL KS. BULK SHEAR WAS GENERALLY 35-40 KTS IN THIS REGION AND MID-LEVEL LAPSE RATES BLO 6 DEG C/KM. BUT... GIVEN PRESENCE OF A HOT AND MOIST BOUNDARY LAYER AND GENERALLY UNIDIRECTIONAL WSWLY FLOW ALOFT...STORMS WILL LIKELY DEVELOP INTO SHORT LINE SEGMENTS GIVING DAMAGING WINDS. FURTHERMORE...A BRIEF ISOLD TORNADO MAY OCCUR...MAINLY ACROSS EXTREME SCNTRL IA/NCNTRL MO WHERE OUTFLOW BOUNDARY INTERSECTIONS MAY AUGMENT LOW-LEVEL HELICITY. ACTIVITY SHOULD MOVE ENEWD INTO/ACROSS THE UPPER MS VLY AND PARTS OF NRN MO OVERNIGHT...BUT LIKELY WEAKEN AS BUOYANCY DECREASES WITH ONSET OF NOCTURNAL COOLING. A FEW TSTMS MAY DEVELOP VCNTY THE SFC LOW/COLD FRONT ACROSS SERN SD INTO SWRN MN AND SWD ACROSS NWRN IA...NERN NEB LATER THIS AFTN. THIS REGION HAS HAD SOME AIR MASS RECOVERY COINCIDENT WITH MASS CONVERGENCE. OTHER THAN ISOLD HAIL/GUSTY WINDS...NO WIDESPREAD SVR TSTMS ARE EXPECTED HERE. FARTHER N...CLOUDS/POOR LAPSE RATE ENVIRONMENT WILL BE NEGATIVE FACTORS FOR SUSTAINED DEEP MOIST CONVECTION FROM MN/WI NWD INTO THE GRTLKS REGION. ..RACY.. 08/13/2006  From swody1 at goshenarc.org Mon Aug 14 00:58:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 20:58:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140057 SWODY1 SPC AC 140056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT SUN AUG 13 2006 VALID 140100Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE KS...NRN MO...SE IA AND WRN IL... ...MID MS VALLEY/CNTRL PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A WELL-DEVELOPED UPPER-LEVEL TROUGH OVER MANITOBA EXTENDING SWD INTO THE NRN PLAINS. ALTHOUGH HARDER TO IDENTIFY...A LEAD SHORTWAVE TROUGH LIKELY EXISTS ACROSS THE NRN MS VALLEY EXTENDING SWWD INTO THE CNTRL PLAINS ALONG THE ERN EDGE OF A PLUME OF MID-LEVEL MOISTURE. THE LARGE LINEAR MCS ONGOING IN SE IA...NRN MO AND NE KS IS LIKELY BEING SUPPORTED BY LARGE-SCALE ASCENT JUST AHEAD OF THE LEAD SHORTWAVE TROUGH. AS THE MCS TRACKS EWD ACROSS NE MO AND WRN IL...SFC DEWPOINTS IN THE UPPER 60S/LOWER 70S F AND MODERATE INSTABILITY SHOULD SUPPORT THE LINE OF THUNDERSTORMS THROUGH LATE EVENING. THE PROFILER AT LATHROP MO CURRENTLY SHOWS A 0-6 KM SHEAR VALUE AROUND 25 KT IN NW MO AND THIS AMOUNT OF SHEAR IS FORECAST TO REMAIN PRESENT THROUGH 06Z. THIS SHOULD BE SUFFICIENT FOR SEVERE MULTICELL THUNDERSTORMS IN NE MO AND WRN IL. AS INSTABILITY DECREASES...THE SEVERE THREAT SHOULD BECOME MORE ISOLATED WITH A GRADUAL DOWNTREND IN STORM INTENSITY OVER THE NEXT 2 TO 3 HOURS. ALTHOUGH HAIL WILL BE POSSIBLE WITH THE STRONGER CELLS...WIND DAMAGE SHOULD BE THE PRIMARY THREAT DUE TO STEEP LOW-LEVEL LAPSE RATES CURRENTLY EXCEEDING 7.0 C/KM EWD INTO THE ST LOUIS AREA. WSWWD ACROSS KS AND NRN OK...LOW-LEVEL LAPSE RATES ARE ALSO STEEP WHICH MAY RESULT IN A FEW MARGINALLY SEVERE STORMS CAPABLE OF STRONG WIND GUSTS FOR 1 TO 2 MORE HOURS. ..BROYLES.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 05:46:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 01:46:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140545 SWODY1 SPC AC 140544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON AUG 14 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY... ...OH VALLEY... AN UPPER-LEVEL TROUGH OVER THE NRN PLAINS WILL DRIFT ESEWD INTO THE GREAT LAKES REGION TODAY AS A COLD FRONT ADVANCES SEWD INTO THE OH VALLEY. SFC DEWPOINTS AHEAD OF THE FRONT SHOULD RANGE FROM AROUND 60 F NEAR LAKE ERIE TO THE LOWER 70S F ACROSS THE MID MS VALLEY. SEVERAL CLUSTERS OF CONVECTION WILL LIKELY BE PRESENT ALONG THE BOUNDARY THIS MORNING. REINTENSIFICATION THIS AFTERNOON SHOULD OCCUR WITH EXISTING CONVECTION AS MODERATE INSTABILITY DEVELOPS AHEAD OF THE FRONT. ADDITIONAL THUNDERSTORMS WILL ALSO LIKELY INITIATE AHEAD OF THE FRONT FROM THE OH VALLEY SWWD INTO THE MID MS VALLEY. THE GREATEST STORM COVERAGE SHOULD OCCUR NEAR THE UPPER-TROUGH ACROSS IND...OH AND NRN KY WHERE LARGE-SCALE ASCENT WILL BE THE STRONGEST. VERTICAL SHEAR AND LIFT WILL LIKELY BE ENHANCED IN THE LATE AFTERNOON AS THE RIGHT ENTRANCE REGION OF A 70 TO 80 KT MID-LEVEL JET MOVES ACROSS THE REGION. FORECAST SOUNDINGS IN IND AND OH THIS AFTERNOON SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE WHICH SHOULD BE SUPPORTIVE OF SEVERE MULTICELLS AND POSSIBLY ISOLATED SUPERCELLS WHERE THE INSTABILITY IS LOCALLY MAXIMIZED. THE UNIDIRECTIONAL FLOW WILL BE FAVORABLE FOR ISOLATED WIND DAMAGE ESPECIALLY WITH SHORT-LINE SEGMENTS IN AREAS WITH LOCALLY STEEP LOW-LEVEL LAPSE RATES. ISOLATED LARGE HAIL MAY ALSO ACCOMPANY ANY SUPERCELLS THAT DEVELOP. ...SRN PLAINS... A COLD FRONT IS FORECAST TO BECOME NEARLY STATIONARY FROM WEST TX EXTENDING EWD ACROSS SRN OK INTO CNTRL AR THIS AFTERNOON. NORTH OF THE FRONT...SCATTERED THUNDERSTORMS SHOULD BE ONGOING THIS MORNING WITH ADDITIONAL THUNDERSTORMS LIKELY INITIATING ALONG AND BEHIND THE BOUNDARY THIS AFTERNOON. SFC HEATING AND DEWPOINTS IN THE LOWER TO MID 60S F SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY BY AFTERNOON. NORTH OF THE BOUNDARY LATE THIS AFTERNOON...BACKED LOW-LEVEL FLOW MAY CREATE ENOUGH DEEP LAYER SHEAR FOR A FEW MULTICELL SEVERE THUNDERSTORMS. HOWEVER...ANY SEVERE THREAT SHOULD REMAIN VERY ISOLATED AND CONCENTRATED NEAR PEAK HEATING. THE STRONGEST THUNDERSTORMS MAY BE CAPABLE OF PRODUCING MARGINALLY SEVERE WIND GUSTS AND HAIL. ...HIGH PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH OVER WRN NV. THIS FEATURE IS FORECAST TO MOVE INTO THE CNTRL ROCKIES AND EMERGE INTO THE CNTRL HIGH PLAINS THIS AFTERNOON. LARGE-SCALE ASCENT AHEAD OF THE SHORTWAVE TROUGH SHOULD BE SUPPORTIVE OF ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT. ALTHOUGH VERTICAL SHEAR PROFILES WILL LIKELY BE SUFFICIENT FOR SEVERE STORMS...THE AMOUNT OF INSTABILITY THAT WILL BE IN PLACE THIS AFTERNOON REMAINS IN QUESTION. IF ENOUGH INSTABILITY DEVELOPS...THE SHEAR AND STEEP LAPSE RATES SHOULD SUPPORT AT LEAST A FEW MARGINALLY SEVERE STORMS CAPABLE OF HAIL AND STRONG GUSTY WINDS. ..BROYLES/TAYLOR.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 12:28:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 08:28:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141229 SWODY1 SPC AC 141227 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0727 AM CDT MON AUG 14 2006 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG UPPER TROUGH CONTINUES TO TRACK EASTWARD ACROSS THE GREAT LAKES REGION THIS MORNING...WITH BROAD UPPER RIDGE REMAINING IN PLACE THROUGHOUT THE SOUTHERN STATES. A WEAKENING COLD FRONT WILL SWEEP SOUTHEASTWARD FROM THE OH VALLEY INTO THE CENTRAL PLAINS...PROVIDING A FOCUS FOR SCATTERED THUNDERSTORMS. OTHER CONVECTION IS EXPECTED TODAY OVER THE CENTRAL HIGH PLAINS...AND OVER PORTIONS OF THE SOUTHWEST STATES. ...OH VALLEY... SURFACE COLD FRONT IS CURRENTLY ANALYZED CENTRAL WI INTO SOUTHERN KS. THIS BOUNDARY IS FORECAST TO SWEEP SOUTHEASTWARD...EXTENDING FROM WESTERN OH INTO SOUTHERN MO BY LATE AFTERNOON. AMPLE MOISTURE AND FRONTAL CONVERGENCE SHOULD PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS ALONG THE LENGTH OF THE FRONT. HOWEVER...STRONGER DEEP LAYER VERTICAL SHEAR WILL RESIDE FROM OH NORTHWARD...WHERE FORECAST SOUNDINGS SUGGEST AOB 1000 J/KG OF CAPE WILL BE PRESENT. FROM THERE SOUTHWARD INTO KY...GREATER DAYTIME HEATING AND HIGHER DEWPOINTS WILL PROMOTE A MODERATELY UNSTABLE AIRMASS. BUT RATHER WEAK VERTICAL SHEAR IS EXPECTED IN THIS REGION. THEREFORE...PRESENT INDICATIONS ARE THAT ORGANIZED/SEVERE THUNDERSTORM COVERAGE WILL BE RATHER LOW TODAY. NEVERTHELESS...GUSTY/DAMAGING WINDS AND PERHAPS HAIL WILL BE POSSIBLE IN STRONGEST CELLS TODAY ALONG THE FRONT. ...AR/OK/TX... HOT...HUMID CONDITIONS ARE EXPECTED TO PERSIST AGAIN TODAY ACROSS THIS REGION WITH TEMPERATURES WELL INTO THE 90S. SCATTERED AFTERNOON THUNDERSTORMS ARE EXPECTED FROM THE TX PANHANDLE ACROSS OK INTO AR...ALONG AND SOUTH OF FRONT. STEEP LOW LEVEL LAPSE RATES AND MODERATE CAPE VALUES WILL PROMOTE A RISK OF LOCALIZED DAMAGING WINDS IN STRONGER CELLS. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY SUGGESTS A WEAK UPPER VORT MAX CURRENTLY OVER WESTERN WY. THIS FEATURE IS FORECAST TO MOVE SLOWLY EASTWARD...AND AFFECT THE FOOTHILLS AND FRONT RANGE OF SOUTHEAST WY/NORTHEAST CO THIS AFTERNOON. SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP OVER THE HIGHER TERRAIN AND MOVE EASTWARD INTO THE NEB PANHANDLE AND SOUTHWEST SD DURING THE EVENING. ISOLATED STORMS IN THIS AREA COULD PRODUCE GUSTY WINDS AND HAIL BEFORE DIMINISHING AFTER SUNSET. ...AZ... NORTHEAST UPPER FLOW PATTERN HAS DEVELOPED OVER AZ TODAY...ON EAST SIDE OF UPPER RIDGE CENTERED NEAR YUM. DEEP MONSOONAL MOISTURE REMAINS IN PLACE OVER EASTERN AZ AND MUCH OF NM...WHERE SCATTERED AFTERNOON THUNDERSTORMS ARE EXPECTED. EAST/NORTHEAST UPPER FLOW MAY ALLOW THIS ACTIVITY TO SPREAD INTO LOWER DESERTS FROM PHX-TUS THIS AFTERNOON AND EVENING. GUSTY/DAMAGING WINDS COULD OCCUR NEAR STRONGER STORMS. ..HART/TAYLOR.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 16:18:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 12:18:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141618 SWODY1 SPC AC 141616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 AM CDT MON AUG 14 2006 VALID 141630Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF ERN WY/NEB PANHANDLE AND SWRN SD... ...SYNOPSIS... PROGRESSIVE TROUGH CONTINUES EWD ACROSS GREAT LAKES TO NERN U.S. THIS FORECAST PERIOD. COLD FRONT ACCOMPANYING TROUGH THIS AM LOCATED FROM LOWER MI SWWD THRU SWRN MO TO SCENTRAL OK THEN WWD TO CENTRAL NM. SURFACE HIGH CENTRAL NEB WILL SHIFT TO LOWER MO VALLEY BY 12Z TUE ALLOWING SELY UPSLOPE FLOW TO PERSIST THE LEE OF CENTRAL ROCKIES. ...ERN WY/NEB PANHANDLE/SWRN SD... CONSISTENT MODEL SIGNAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON IN THE CURRENT UPSLOPE REGIME LEE OF CENTRAL ROCKIES. WITH DEWPOINTS EXPECTED TO HOLD AT 50 F OR HIGHER E OF HIGHER TERRAIN AS FAR N AS ECENTRAL WY...AIR MASS EXPECTED TO BECOME SUFFICIENTLY UNSTABLE TO SUPPORT STRONG/SEVERE THUNDERSTORMS. WITH LAPSE RATES IN EXCESS OF 8C/KM AND VEERING SHEAR PROFILES UPWARDS TO 30KT...PARAMETERS SHOULD BE IN PLACE FOR AT LEAST ISOLATED SUPERCELL DEVELOPMENT VICINITY NEB/WY BORDER BY LATE AFTERNOON. WITH LOW LEVEL SELYS OF ONLY 10-15KT AND LIFTED CONDENSATION LEVELS AROUND 2KM AGL...PRIMARY THREAT WOULD BE LARGE HAIL. ...OH VALLEY ACROSS SRN PLAINS... MUCH OF THIS REGION ALONG AND AHEAD OF COLD FRONT IS CHARACTERIZED BY WARM 500 MB TEMPERATURES AND GENERALLY WEAK LOW LEVEL SHEAR. WITH PW/S BETWEEN 1.5 AND 2 INCHES ALONG WITH STRONG SURFACE HEATING...MLCAPES OF 2000 J/KG WILL BE COMMON BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT BY THIS AFTERNOON HOWEVER SEVERE THREAT EXPECTED TO BE LIMITED TO LOCAL DAMAGING DOWNBURSTS FROM PRIMARILY PULSE AND MULTICELLULAR CONVECTION. STRONGER DEEP LAYER SHEAR UPWARDS TO 30KT WILL BE AVAILABLE ACROSS UPPER OH VALLEY...BUT THE WARM MID LEVELS SHOULD LIMIT UPDRAFT STRENGTH. THUS ONLY ISOLATED POTENTIAL FOR WIND DAMAGE IS EXPECTED. ...AZ... DRIER AIR IS GRADUALLY WORKING EWD AT MID LEVELS ACROSS CENTRAL AZ AS NOTED ON FLG AND PHX 12Z SOUNDINGS. LOW LEVELS REMAIN VERY MOIST...THUS THUNDERSTORMS WILL DEVELOP OVER HIGHER TERRAIN BY MID AFTERNOON. THE ENTRAINMENT OF THE DRIER MID LEVEL AIR DOES INCREASE POTENTIAL FOR DOWNBURSTS...THOUGH THE GENERALLY WEAK STEERING FLOW PRECLUDES A SLIGHT RISK. ..HALES/JEWELL.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 16:32:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 12:32:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141633 SWODY1 SPC AC 141631 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1131 AM CDT MON AUG 14 2006 VALID 141630Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF ERN WY/NEB PANHANDLE AND SWRN SD... CORRECTED FOR REVERSAL OF HAIL PROB LINE IN AZ ...SYNOPSIS... PROGRESSIVE TROUGH CONTINUES EWD ACROSS GREAT LAKES TO NERN U.S. THIS FORECAST PERIOD. COLD FRONT ACCOMPANYING TROUGH THIS AM LOCATED FROM LOWER MI SWWD THRU SWRN MO TO SCENTRAL OK THEN WWD TO CENTRAL NM. SURFACE HIGH CENTRAL NEB WILL SHIFT TO LOWER MO VALLEY BY 12Z TUE ALLOWING SELY UPSLOPE FLOW TO PERSIST THE LEE OF CENTRAL ROCKIES. ...ERN WY/NEB PANHANDLE/SWRN SD... CONSISTENT MODEL SIGNAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON IN THE CURRENT UPSLOPE REGIME LEE OF CENTRAL ROCKIES. WITH DEWPOINTS EXPECTED TO HOLD AT 50 F OR HIGHER E OF HIGHER TERRAIN AS FAR N AS ECENTRAL WY...AIR MASS EXPECTED TO BECOME SUFFICIENTLY UNSTABLE TO SUPPORT STRONG/SEVERE THUNDERSTORMS. WITH LAPSE RATES IN EXCESS OF 8C/KM AND VEERING SHEAR PROFILES UPWARDS TO 30KT...PARAMETERS SHOULD BE IN PLACE FOR AT LEAST ISOLATED SUPERCELL DEVELOPMENT VICINITY NEB/WY BORDER BY LATE AFTERNOON. WITH LOW LEVEL SELYS OF ONLY 10-15KT AND LIFTED CONDENSATION LEVELS AROUND 2KM AGL...PRIMARY THREAT WOULD BE LARGE HAIL. ...OH VALLEY ACROSS SRN PLAINS... MUCH OF THIS REGION ALONG AND AHEAD OF COLD FRONT IS CHARACTERIZED BY WARM 500 MB TEMPERATURES AND GENERALLY WEAK LOW LEVEL SHEAR. WITH PW/S BETWEEN 1.5 AND 2 INCHES ALONG WITH STRONG SURFACE HEATING...MLCAPES OF 2000 J/KG WILL BE COMMON BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT BY THIS AFTERNOON HOWEVER SEVERE THREAT EXPECTED TO BE LIMITED TO LOCAL DAMAGING DOWNBURSTS FROM PRIMARILY PULSE AND MULTICELLULAR CONVECTION. STRONGER DEEP LAYER SHEAR UPWARDS TO 30KT WILL BE AVAILABLE ACROSS UPPER OH VALLEY...BUT THE WARM MID LEVELS SHOULD LIMIT UPDRAFT STRENGTH. THUS ONLY ISOLATED POTENTIAL FOR WIND DAMAGE IS EXPECTED. ...AZ... DRIER AIR IS GRADUALLY WORKING EWD AT MID LEVELS ACROSS CENTRAL AZ AS NOTED ON FLG AND PHX 12Z SOUNDINGS. LOW LEVELS REMAIN VERY MOIST...THUS THUNDERSTORMS WILL DEVELOP OVER HIGHER TERRAIN BY MID AFTERNOON. THE ENTRAINMENT OF THE DRIER MID LEVEL AIR DOES INCREASE POTENTIAL FOR DOWNBURSTS...THOUGH THE GENERALLY WEAK STEERING FLOW PRECLUDES A SLIGHT RISK. ..HALES.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 19:55:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 15:55:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141955 SWODY1 SPC AC 141953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT MON AUG 14 2006 VALID 142000Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CO/WY/SWRN SD/WRN NEB... ...THERE IS A SLGT RISK OF SVR TSTMS LOWER OH VALLEY THROUGH OZARKS... ...SYNOPSIS... SYNOPTIC PATTERN WILL REMAIN CHARACTERIZED BY PROGRESSIVE NRN STREAM ACROSS NRN 1/2-1/3 OF CONUS. ELONGATED AREA OF RIDGING ALOFT -- INTERSPERSED WITH SEVERAL WEAK AND SLOW-MOVING SHORTWAVES -- WILL EXTEND FROM AZ ACROSS SRN PLAINS...EWD TO OFFSHORE GA/SC. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NRN ONT AND UPPER GREAT LAKES REGION...WILL CONTINUE TO MOVE EWD TOWARD ERN ONT AND QUE. ASSOCIATED SFC COLD FRONT IS ANALYZED FROM ERN LOWER MI SWWD ACROSS SWRN MO AND SRN TX PANHANDLE. FRONT HAS STALLED OVER SRN PLAINS AND SHOULD DECELERATE ACROSS OZARKS AREA...WHILE MOVING SEWD THROUGH MID/UPPER OH VALLEY REGION. ...CENTRAL HIGH PLAINS... VIS IMAGERY INDICATED CB DEVELOPING AND INCREASING IN COVERAGE OVER FRONT/LARAMIE RANGES. FARTHER E ACROSS HIGH PLAINS...AXIS OF RELATIVELY STEEP MIDLEVEL LAPSE RATES -- 8-8.5 DEG C/KM -- IS ANALYZED ACROSS THIS AREA. THIS CROSSES N-S ORIENTED BOUNDARY LAYER MOIST AXIS OVER SERN WY...WITH MOIST PLUME EXTENDING SSEWD ACROSS ERN CO. DEEP-LAYER VERTICAL SHEAR PROFILES INCREASE WITH NWD EXTENT...AND PROXIMITY TO MID/UPPER LEVEL NRN STREAM JET...AND SLY MOIST ADVECTION WILL COMBINE WITH DIABATIC HEATING TO INCREASE BUOYANCY NWD ACROSS SWRN ND AND ERN WY. THESE FACTORS WILL SUPPORT INTENSIFICATION OF CONVECTION OVER THIS REGION TO SVR LEVELS WITH LARGE HAIL AND OCCASIONAL DAMAGING GUSTS POSSIBLE. REF SPC WW 720 AND RELATED MESOSCALE DISCUSSIONS FOR NEAR-TERM DETAILS. ...OH VALLEY TO SRN PLAINS... WIDELY SCATTERED TO SCATTERED TSTMS ARE EXPECTED THROUGH REMAINDER AFTERNOON INTO EVENING HOURS...ALONG/AHEAD OF SFC COLD FRONT...FROM WRN UPSTATE NY TO SRN HIGH PLAINS. IN ADDITION TO FRONT...OUTFLOW BOUNDARIES WILL ACT AS FOCI FOR CONVECTIVE INITIATION. ISOLATED DAMAGING DOWNBURSTS ARE POSSIBLE FROM PULSE/MULTICELL CONVECTION ALMOST ANYWHERE WITHIN THAT SWATH. MOST PROBABLE AREA FOR RELATIVELY DENSE CONCENTRATION OF MULTICELLS...AND OF POTENTIAL FOR MULTIPLE STG-SVR TSTMS...APPEARS TO BE FROM NRN AR TOWARD SWRN INDIANA/WRN KY. PRE-STORM AIR MASS ACROSS THIS AREA WILL CONTINUE TO BE FAVORABLY UNSTABLE FOR SEVERAL MORE HOURS WITH 70S SFC DEW POINTS AND STG HEATING CONTRIBUTING TO MLCAPES IN 2500-3500 J/KG RANGE. SVR POTENTIAL IS STRONGLY TIED TO DIABATIC HEATING AND EXPECTED TO WEAKEN GRADUALLY AFTER SUNSET. ...SERN AZ/SWRN NM... WIDELY SCATTERED TSTMS SHOULD INCREASE IN COVERAGE THROUGH REMAINDER AFTERNOON. MOST FAVORABLE AREA FOR ISOLATED DAMAGING GUSTS AND HAIL NEAR SVR LEVELS IS IN CORRIDOR FROM NWRN TO SERN AZ WHERE ERN PORTION OF STRONGEST SFC WARMING WILL OVERLAP WRN EXTENT OF RICH LOW LEVEL MOISTURE PLUME. SFC DEW POINTS MID 70S F WILL SUPPORT MLCAPES 1500-2500 J/KG OVER MOST DESERT AREAS...THOUGH WITH WEAK AMBIENT FLOW...OROGRAPHICALLY INITIATED STORMS WILL BE SLOW TO MOVE OVER DEEPER BOUNDARY LAYERS OF DESERTS. HOWEVER...ADDITIONAL DEVELOPMENT MAY OCCUR ALONG OUTFLOW BOUNDARIES GENERATED BY EARLIEST CONVECTION. TSTMS SHOULD DIMINISH IN COVERAGE AND INTENSITY AFTER NIGHTFALL...BECAUSE OF COMBINED STABILIZING EFFECTS OF SPREADING OUTFLOW AIR AND SFC DIABATIC COOLING. ..EDWARDS.. 08/14/2006  From swody1 at goshenarc.org Tue Aug 15 00:55:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 20:55:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150056 SWODY1 SPC AC 150054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0754 PM CDT MON AUG 14 2006 VALID 150100Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID MS VALLEY... ...HIGH PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH DRIFTING EWD INTO WRN SD ATTM. SCATTERED THUNDERSTORMS ARE ONGOING ALONG THE LEADING EDGE OF LARGE-SCALE ASCENT AND JUST AHEAD OF A WELL-DEFINED DRY SLOT. THE STORMS ARE FORMING ALONG THE WRN EDGE OF THE LOW-LEVEL MOIST AXIS IN A SMALL POCKET OF MODERATE INSTABILITY WHERE MLCAPE VALUES RANGE FROM 1000 TO 1500 J/KG. THE INSTABILITY IN PLACE SHOULD SUSTAIN STRONG UPDRAFTS THROUGH MUCH OF THE EVENING. THE 00Z SOUNDING AT RAPID CITY SHOWS A STRONG VEERING WIND PROFILE WHICH IS SUPPORTING SUPERCELLS ONGOING IN SW SD ATTM. THE CLUSTER OF SEVERE THUNDERSTORMS IS LOCATED ALONG THE ERN EDGE OF VERY STEEP MID-LEVEL LAPSE RATES. IN ADDITION...0-3 KM LAPSE RATES IN SWRN SD EXCEED 9.0 C/KM WHICH ALONG WITH THE SHEAR SUGGESTS THE THREAT FOR LARGE HAIL AND WIND DAMAGE WILL CONTINUE WITH THE STRONGER CELLS THIS EVENING. ...MID MS VALLEY/SRN PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A LARGE UPPER-LEVEL TROUGH OVER ONTARIO EXTENDING SWD INTO THE OH VALLEY REGION. NUMEROUS THUNDERSTORMS ARE ONGOING ALONG THE SRN EDGE OF A PLUME OF MID-LEVEL MOISTURE EXTENDING ENEWD FROM NRN OK ACROSS MO INTO THE LOWER OH VALLEY. THE HIGHEST SFC DEWPOINTS AND STRONGEST INSTABILITY EXISTS ACROSS NE AR...SE MO...NW TN AND WRN KY WHERE MLCAPE VALUES RANGE FROM 2500 TO 3000 J/KG ACCORDING TO RUC ANALYSIS. THE 00Z NASHVILLE SOUNDING SHOWS ABOUT 25 KT OF VERTICAL SHEAR WHICH COMBINED WITH THE STRONG INSTABILITY SHOULD BE SUFFICIENT TO CONTINUE A THREAT FOR MULTICELLS CAPABLE OF ISOLATED WIND DAMAGE FOR A FEW MORE HOURS. THE THREAT SHOULD DECREASE THIS EVENING AS LOW-LEVEL LAPSE RATES CONTINUE TO WEAKEN. ...SRN AND CNTRL AZ... A BROKEN LINE OF STRONG THUNDERSTORMS IS CURRENTLY ONGOING IN CNTRL AZ. THE STORMS ARE LOCATED ALONG AND JUST TO THE SOUTHWEST OF A MOIST AXIS WHERE DEWPOINTS RANGE FROM 55 TO 65 F. MUCAPE VALUES ABOVE 1500 J/KG AS SHOWN ON REGIONAL SOUNDINGS LARGE TEMP-DEWPOINT SPREADS MAY BE FAVORABLE FOR A FEW THUNDERSTORMS CAPABLE OF MARGINALLY SEVERE WIND DAMAGE EARLY THIS EVENING. ..BROYLES.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 05:53:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 01:53:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150553 SWODY1 SPC AC 150552 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1252 AM CDT TUE AUG 15 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...NRN PLAINS... AN UPPER-LEVEL TROUGH OVER THE PACIFIC NORTHWEST IS FORECAST TO DEEPEN TODAY AS A LEAD SHORTWAVE TROUGH MOVES INTO THE NRN ROCKIES THIS AFTERNOON. THUNDERSTORMS SHOULD INITIATE IN THE HIGHER TERRAIN OF ID AND MT IN THE AFTERNOON WITH ADDITIONAL CONVECTION DEVELOPING IN THE NRN HIGH PLAINS AS THE TROUGH COMES OUT OF THE ROCKIES THIS EVENING. FORECAST SOUNDINGS ACROSS ERN MT AND WRN ND THIS EVENING SHOW MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES. THIS SHOULD BE ENOUGH FOR A FEW SEVERE STORMS IF THUNDERSTORM INITIATION OCCURS IN AREAS WITH THE STRONGER INSTABILITY. HOWEVER...UNCERTAINTY CONCERNING TIMING AND DESTABILIZATION STILL REMAINS. ONCE CERTAINTY INCREASES IN THE SCENARIO...AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...TN VALLEY/LOWER MS VALLEY... SCATTERED TO NUMEROUS THUNDERSTORMS WILL AGAIN INITIATE THIS AFTERNOON ALONG AND BEHIND A COLD FRONT POSITIONED FROM SRN MS EXTENDING NEWD ACROSS AL AND GA. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW MODERATE INSTABILITY WITH RELATIVELY WEAK SHEAR PROFILES. ALTHOUGH A FEW MARGINALLY SEVERE THUNDERSTORMS SHOULD DEVELOP...THE WEAK SHEAR SHOULD KEEP ANY THREAT ISOLATED. STRONG GUSTY WINDS WILL BE POSSIBLE WITH THE STRONGER THUNDERSTORMS NEAR AREAS OF LOCALLY STEEP LOW-LEVEL LAPSE RATES. ..BROYLES/TAYLOR.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 12:53:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 08:53:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151222 SWODY1 SPC AC 151220 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0720 AM CDT TUE AUG 15 2006 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MS VALLEY/TN VALLEY/CAROLINAS... LARGE UPPER TROUGH IS MOVING ACROSS EASTERN CANADA THIS MORNING...WITH BROAD UPPER RIDGE MAINTAINING CONTROL ACROSS THE SOUTHERN STATES. WEAK SURFACE BAROCLINIC ZONE EXTENDS FROM MID ATLANTIC REGION INTO OK/AR. THIS ZONE WILL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS. AIR MASS ALONG AND SOUTH OF BOUNDARY WILL BE HOT TODAY WITH TEMPERATURES IN THE 90S...ALONG WITH DEWPOINTS NEAR 70F. DESPITE HIGH THETA-E VALUES AT THE SURFACE...WARM TEMPERATURES ALOFT WILL LIMIT LAPSE RATES AND AVAILABLE CAPE. ALSO...BOUNDARY HAS SAGGED SOUTH OF STRONGER WESTERLIES ALOFT...WITH ONLY WEAK VERTICAL SHEAR PROFILES SHOWN ON FORECAST SOUNDINGS. ISOLATED CELLS ALONG THIS AXIS WILL BE CAPABLE OF LOCALLY GUSTY WINDS. HOWEVER...ORGANIZED SEVERE THUNDERSTORM ACTIVITY DOES NOT APPEAR LIKELY. ...NORTHERN HIGH PLAINS... SERIES OF WEAK UPPER FEATURES ARE NOTED ON MORNING WATER VAPOR IMAGERY OVER THE NORTHERN GREAT BASIN AND NORTHERN ROCKIES. THESE FEATURES HAVE RESULTED IN SCATTERED THUNDERSTORMS OVER PARTS OF ID/UT/WY OVERNIGHT. STEEP MID LEVEL LAPSE RATES AND FAST SOUTHWESTERLY FLOW ALOFT WILL PROMOTE A CONTINUED RISK OF GUSTY/DAMAGING WINDS IN CONVECTION THROUGH THE DAY AS IT SPREADS EASTWARD TOWARD THE WESTERN DAKOTAS. POTENTIAL EXISTS FOR RE-DEVELOPMENT OF SCATTERED THUNDERSTORMS THIS AFTERNOON OVER PARTS OF EASTERN ID/NORTHWEST WY...WITH A RENEWED THREAT OF DAMAGING WINDS. FINALLY...ISOLATED THUNDERSTORMS MAY INTENSIFY EARLY THIS EVENING OVER PARTS OF ND/SD AS SOUTHERLY LOW LEVEL JET INTENSIFIES AND ENHANCES WARM ADVECTION. FORECAST SOUNDINGS SUGGEST A THREAT OF HIGH-BASED SUPERCELLS IN THIS REGION...WITH A RISK OF HAIL AND GUSTY WINDS. ..HART/TAYLOR.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 16:18:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 12:18:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151617 SWODY1 SPC AC 151615 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 AM CDT TUE AUG 15 2006 VALID 151630Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PRIMARY WESTERLIES REMAIN ACROSS NRN TIER OF CONUS WITH PROGRESSIVE LARGE SCALE FEATURES. TROUGH MOVING EWD THRU NERN STATES WHILE SOME AMPLIFICATION OCCURS UPSTREAM WITH TROUGH ENTERING PAC NW. BROAD RIDGE SHIFTS EWD ACROSS NRN PLAINS/UPPER MS VALLEY THIS FORECAST PERIOD. S/WV IMPULSE RIDING ACROSS RIDGE LOCATED WY/SRN MT WILL CROSS NRN PLAINS TONIGHT. COLD FRONT WILL MOVE OFF NERN COAST THIS AFTERNOON TRAILING WSWWD THRU DELMARVA TO TN/MID MS VALLEY. WWD ACROSS SRN PLAINS FRONT WILL BEGIN LIFTING NWD AS LEE TROUGH DEVELOPS E OF ROCKIES. ...NRN HIGH PLAINS... RATHER ACTIVE OVERNIGHT HIGH BASED CONVECTION NOTED WITH S/WV NOW CROSSING WY/SRN MT. THIS FEATURE WILL PROVIDE SOME DYNAMIC SUPPORT ALONG WITH ENHANCED DEEP LAYER SHEAR FOR POTENTIAL OF STRONG/SEVERE THUNDERSTORMS THIS AFTERNOON. WITH STEEP LAPSE RATES IN PLACE AND LOW LEVEL MOISTURE SPREADING NWD THRU HIGH PLAINS E OF LEE TROUGH...EXPECT AT LEAST ISOLATED SEVERE STORMS TO DEVELOP BY MID AFTERNOON WITH PRIMARY THREAT LARGE HAIL AND DOWNBURST WINDS. WHILE SHEAR OF 35-40KT SUGGESTS AN UPGRADE COULD BE NEEDED...THERE IS SUFFICIENT DOUBT AS TO AVAILABLE MOISTURE/INSTABILITY TO SUPPORT THE STORM COVERAGE NEED FOR A SLIGHT RISK ATTM. PORTION OF HIGH PLAINS COULD BE UPGRADED IN AFTERNOON UPDATE. FARTHER W STEEP LAPSE RATES AND STRONG HEATING WILL SUPPORT REDEVELOPMENT OF HIGH BASED STORMS FROM SERN ID ACROSS NRN WY/SRN MT. PRIMARY THREAT WOULD BE ISOLATED STRONG WINDS. ...MID ATLANTIC STATES WWD TO LOWER MS VALLEY... AIR MASS S OF FRONTAL ZONE REMAINS MOIST AND POTENTIALLY VERY UNSTABLE. WHILE WEAK SHEAR PROFILES SUPPORT PRIMARILY PULSE STORMS...MLCAPES UPWARDS TO 2000 J/KG AND STEEP LOW LEVEL LAPSE RATES SUPPORT WET DOWNBURSTS. SEVERE THREAT WILL BE HIGHLY DIURNAL DIMINISHING BY SUNSET. ..HALES/GUYER.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 20:04:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 16:04:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152003 SWODY1 SPC AC 152002 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0302 PM CDT TUE AUG 15 2006 VALID 152000Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS EXTREME ERN WY...NWRN NEB...SD...SERN ND...WRN MN... ...SYNOPSIS... IN MIDDLE-UPPER LEVELS...PROGRESSIVE NRN STREAM PATTERN WILL BE DOMINATED BY WEAKENING TROUGH OVER QUE/NERN CONUS...AND AMPLIFYING TROUGH MOVING SEWD INTO PACIFIC NW STATES. MEAN RIDGE WILL CONTINUE SHIFTING EWD ACROSS NRN PLAINS TOWARD UPPER MS VALLEY. WEAK SRN STREAM PERTURBATIONS NOW OVER W TX AND NM ARE EXPECTED TO LIFT NEWD ACROSS SRN ROCKIES AND SRN PLAINS THROUGH REMAINDER PERIOD. AT SFC...COLD FRONT IS EVIDENT FROM DELMARVA PENINSULA SWWD THROUGH SRN APPALACHIANS...BECOMING QUASISTATIONARY WWD ACROSS AR...THEN WARM FRONT ACROSS OK. LEESIDE CYCLOGENESIS IS EVIDENT ACROSS NRN HIGH PLAINS...WITH SEVERAL WEAK LOW PRESSURE CENTERS FROM SRN SASK SEWD ACROSS SD. FRONTOGENESIS ACROSS SRN SASK AND NRN MT SHOULD RESULT IN COLD FRONT MOVING SEWD OVER ERN MT AND INTO NWRN ND BY 16/12Z. ...NRN PLAINS... INITIALLY ELEVATED DEVELOPMENT EVIDENT ATTM OVER NERN SD MAY CONTINUE AND MOVE EWD ACROSS PORTIONS CENTRAL/NRN MN THROUGH REMAINDER EVENING. ALTHOUGH MOISTURE WILL REMAIN MRGL WITH SFC DEW POINTS MID 50S TO AROUND 60 F...STG SFC HEATING IN MODIFIED FCST SOUNDINGS RENDERS SFC-BASED PARCELS AND INVERTED-V SHAPE TO BOUNDARY LAYER THERMODYNAMIC PROFILE. VERTICAL SHEAR PROFILES IN RUC FCST SOUNDINGS SHOW CONSIDERABLE VEERING WITH HEIGHT AND SUGGEST SOME SUPERCELL POTENTIAL...WITH ORGANIZED MULTICELL CONVECTION ALSO POSSIBLE. THEREFORE POTENTIALLY DAMAGING GUSTS AND LARGE HAIL MAY OCCUR WITH SOME OF THIS ACTIVITY...AS WELL AS WITH SFC-BASED CONVECTION DEVELOPING FARTHER W ACROSS ERN WY AND SWRN SD. LATTER ACTIVITY IS OCCURRING IN SOMEWHAT WEAKER SHEAR ENVIRONMENT BUT WILL MOVE ALONG OR PARALLEL TO SFC MOIST AXIS -- ANALYZED ATTM FROM SERN WY NEWD ACROSS BADLANDS OF SD...TO NERN CORNER SD AND INTO SWRN MN. SVR POTENTIAL MAY PERSIST AFTER DARK INVOF NOSE OF STRENGTHENING LLJ...WHICH WILL ADVECT INCREASINGLY RICH MOISTURE NWD FROM SRN PLAINS AND CENTRAL HIGH PLAINS IN A NARROW PLUME. ...SERN CONUS...SRN PLAINS... SCATTERED TSTMS IN MULTICELL CLUSTERS ALREADY HAVE DEVELOPED IN BKN BAND FROM CENTRAL VA SWWD TO ERN MS. THIS ACTIVITY SHOULD SHIFT/EXPAND SWD AND SWWD THROUGH REMAINDER AFTERNOON...AS CONVECTIVE OUTFLOWS PROPAGATE INITIATION POTENTIAL DEEPER INTO MARITIME/TROPICAL AIR MASS THAT CHARACTERIZES MUCH OF SERN CONUS. DEVELOPMENT ALSO IS EXPECTED ALONG AND S OF FRONT WWD ACROSS AR INTO CENTRAL/ERN OK...WHERE STRONGEST HEATING IS OCCURRING. SFC DEW POINTS MID 60S/MID 70S F AND INSOLATION WILL SUPPORT MLCAPES 2500-4000 J/KG FROM NWRN GA INTO SERN OK...AMIDST WEAKENING CINH. WEAK DEEP-LAYER KINEMATIC PROFILES ARE EXPECTED TO LIMIT OVERALL ORGANIZATION OF CONVECTION IN THIS CORRIDOR. PULSE AND MULTICELL MODES ARE EXPECTED WITH SVR POTENTIAL BEING BRIEF AND ISOLATED...THEREFORE PROBABILITIES REMAIN TOO LOW TO WARRANT CATEGORICAL OUTLOOK ATTM. ..EDWARDS.. 08/15/2006  From swody1 at goshenarc.org Wed Aug 16 00:56:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 20:56:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160057 SWODY1 SPC AC 160055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT TUE AUG 15 2006 VALID 160100Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SD...SERN ND AND WRN MN... ...SYNOPSIS... PROGRESSIVE NRN STREAM PATTERN WILL CONTINUE ALOFT...WITH TROUGH WEAKENING/EJECTING ACROSS QUE AND NEW ENGLAND...MEAN RIDGE SHIFTING EWD OVER NRN PLAINS/UPPER MS VALLEY REGION...AND NERN PACIFIC TROUGH DIGGING ESEWD INTO PACIFIC NW. AT SFC...COLD FRONT IS ANALYZED FROM SRN DELMARVA PENINSULA SWWD THROUGH SRN APPALACHIANS...BECOMING QUASISTATIONARY WWD ACROSS AR...THEN DIFFUSE AND CONVECTIVELY MODULATED WARM FRONT OVER PORTIONS NRN OK/SRN KS. LEESIDE CYCLOGENESIS CONTINUES OVER NRN HIGH PLAINS...WHERE SEVERAL WEAK LOW PRESSURE CENTERS EVIDENT EARLIER THIS AFTERNOON HAVE CONSOLIDATED INTO TWO MAIN LOWS...INVOF NERN AND SERN CORNERS OF MT. WARM FRONT IS BECOMING BETTER DEFINED ACROSS NRN SD...AND SHOULD LIFT NWD INTO SRN ND AND ACROSS WRN MN OVERNIGHT. ...NRN PLAINS TO UPPER MS VALLEY... PRIMARY UNCONDITIONAL SEVERE THREAT WILL OCCUR THROUGH APPROXIMATELY 05Z...ASSOCIATED WITH POTENTIAL FOR ADDITIONAL DEVELOPMENT WITHIN...OR UPSCALE EVOLUTION OF...TWO PRIMARY NODES OF DIURNAL CONVECTIVE DEVELOPMENT -- OVER NERN SD/WRN MN AND OVER SWRN ND. REF SPC WW 722 AND RELATED MESOSCALE DISCUSSIONS FOR SHORT-TERM FCST DETAILS. SOME POTENTIAL EXISTS FOR MCS TO EVOLVE OVERNIGHT INVOF NOSE OF INCREASINGLY MOIST LLJ OVER SD...IN ZONE OF STRONGEST LOW LEVEL WAA AND MOIST ADVECTION ABOVE SFC. HOWEVER AVAILABLE RAOB DATA AND RUC PROGS INDICATE OPTIMAL 850 MB DEW POINTS MAY NOT REACH THIS AREA UNTIL AFTER 06Z. THIS CASTS DOUBT ON PERSISTENCE OF CURRENT OUTFLOW-DOMINANT CONVECTION ONCE BOUNDARY LAYER MORE STRONGLY COOLS/DECOUPLES AND REDUCES SBCAPE. ...SERN CONUS... PRIMARY AREA OF CONCERN FOR STG...POTENTIALLY DAMAGING GUSTS THROUGH REMAINDER EVENING WILL BE AREA ALONG AND S OF ONGOING CLUSTER OF ORGANIZED MULTICELLS...NOW MOVING SWD ACROSS AL AND SRN MS. AIR MASS BETWEEN THIS ACTIVITY AND GULF COAST WILL REMAIN FAVORABLY MOIST AND UNSTABLE WITH SFC DEW POINTS 70S F...AND MLCAPES 1500-2000 J/KG PER MODIFIED TLH RAOBS AND RUC SOUNDINGS. SOME POTENTIAL FOR GUSTS NEAR SVR LEVELS MAY PERSIST ANOTHER 1-2 HOURS ELSEWHERE ALONG AND S OF FRONTAL ZONE...FROM OK TO ATLANTIC COAST...HOWEVER THIS POTENTIAL IS BECOMING TOO BRIEF/ISOLATED TO WARRANT SVR PROBABILITIES. ..EDWARDS.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 06:00:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 02:00:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160559 SWODY1 SPC AC 160558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT WED AUG 16 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... ...CNTRL PLAINS... AN UPPER-LEVEL RIDGE OVER THE MO VALLEY WILL SHIFT EWD TODAY AS A SHORTWAVE TROUGH MOVES NEWD OUT OF THE CNTRL ROCKIES. A WEAK FRONTAL BOUNDARY OVER THE SRN PLAINS WILL MOVE NWD EXTENDING FROM NCNTRL KS INTO SW NEB. CONVERGENCE ALONG THE BOUNDARY COMBINED WITH LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE TROUGH SHOULD PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THUNDERSTORMS APPEAR LIKELY TO INITIATE NEAR THE BOUNDARY IN CNTRL AND NRN KS WITH CONVECTION EXPANDING NEWD ACROSS CNTRL AND ERN NEB. ADDITIONAL THUNDERSTORM DEVELOPMENT APPEARS LIKELY ALONG A SFC TROUGH EXISTING IN NE CO AND WRN NEB. FORECAST SOUNDINGS ACROSS SRN AND CNTRL NEB THIS AFTERNOON SHOW SUBSTANTIAL VEERING BELOW 700 MB WITH 0-6 KM SHEAR VALUES IN THE 25 TO 30 KT RANGE. THIS SHOULD BE FAVORABLE FOR ISOLATED SUPERCELLS IN AREAS WITH THE STRONGEST INSTABILITY. HOWEVER...MOST OF THE CONVECTION SHOULD REMAIN MULTICELL AS AN MCS ORGANIZES AND MOVES INTO ERN NEB AND POSSIBLY WRN IA BY EVENING. THE CURRENT THINKING IS THAT THE GREATEST SEVERE THREAT WILL BE THE MID-AFTERNOON BEFORE THE CONVECTION BECOMES ELEVATED NORTHEAST OF THE BOUNDARY. ALTHOUGH HAIL WILL BE POSSIBLE WITH THE STRONGER CELLS...THE MOST PROBABLE SEVERE THREAT WILL BE WIND DAMAGE JUST AFTER INITIATION NEAR THE BOUNDARY WHERE LOW-LEVEL LAPSE RATES ARE FORECAST TO BE THE STEEPEST. FURTHER NORTHWEST ACROSS WRN NEB...ISOLATED TO SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG A NORTH TO SOUTH SFC TROUGH WITH THE CONVECTION MOVING EWD INTO WRN NEB DURING THE LATE AFTERNOON. FORECAST SOUNDINGS IN WRN NEB THIS AFTERNOON SHOW STRONG ENOUGH VERTICAL SHEAR FOR SEVERE MULTICELLS. THE CONVECTION SHOULD BE THE STRONGEST IN THE LATE AFTERNOON AND EARLY EVENING AS LOW-LEVEL FLOW STRENGTHENS ACROSS THE REGION. STEEP LAPSE RATES AND COOLER MID-LEVEL TEMPS WILL LIKELY FAVOR EITHER A THREAT FOR HAIL AND/OR ISOLATED WIND DAMAGE WITH THE MORE ORGANIZED STORMS. ...NRN PLAINS... AN UPPER-LEVEL RIDGE OVER THE PLAINS STATES WILL MOVE INTO THE GREAT LAKES REGION TODAY AS A SHORTWAVE TROUGH DRIFTS ENEWD INTO THE NRN PLAINS. A COLD FRONT WILL ADVANCE SEWD ACROSS ND AND THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE BOUNDARY DURING THE AFTERNOON. FORECAST SOUNDINGS IN ERN ND THIS AFTERNOON SHOW MODERATE INSTABILITY AND STRONG ENOUGH SHEAR PROFILES FOR ORGANIZED MULTICELLS. HOWEVER...THE NUMBER OF STORMS THAT WILL INITIATE REMAINS UNCERTAIN WHICH COULD LIMIT THE SEVERE WEATHER THREAT AREA. IF A SHORTWAVE CURRENTLY OVER THE NRN ROCKIES TIMES WELL WITH MAXIMUM INSTABILITY ACROSS ERN ND...A SLIGHT RISK UPGRADE MAY BECOME NECESSARY IN LATER OUTLOOKS. ...NRN ROCKIES... A WELL-DEVELOPED UPPER-LEVEL TROUGH OFF THE COAST OF THE PACIFIC NORTHWEST WILL MOVE INLAND TODAY. THIS WILL SPREAD STRONG LARGE-SCALE ASCENT EWD INTO ID AND WRN MT WITH SCATTERED THUNDERSTORM INITIATION LIKELY IN THE HIGHER TERRAIN THIS AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON IN THE NRN ROCKIES SHOW STRONG ENOUGH SHEAR PROFILES FOR SEVERE STORMS. IF ENOUGH INSTABILITY CAN DEVELOP IN AREAS WHERE CONVECTION FORMS...HAIL AND STRONG WIND GUSTS WOULD BE POSSIBLE. A SLIGHT RISK AREA MAY BECOME NECESSARY IF POCKETS OF MODERATE INSTABILITY DEVELOP THIS AFTERNOON ACROSS THE REGION. ..BROYLES/BOTHWELL.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 12:46:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 08:46:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161246 SWODY1 SPC AC 161244 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0744 AM CDT WED AUG 16 2006 VALID 161300Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF EASTERN ND AND NORTHWEST MN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF NEB/KS... LARGE UPPER RIDGE REMAINS FROM THE SOUTHERN PLAINS INTO THE OH VALLEY TODAY...WITH SERIES OF SHORTWAVE TROUGHS MOVING FROM THE NRN CALIFORNIA COAST...ACROSS THE CENTRAL/NORTHERN ROCKIES...INTO THE GREAT LAKES REGION. THE OVERALL THREAT OF SEVERE STORMS ACROSS THE NATION IS EXPECTED TO BE RATHER LOW TODAY. HOWEVER...THERE ARE A FEW LOCALIZED AREAS WHERE GREATER THREATS OF HAIL/DAMAGING WINDS WILL EXIST. ...ND/MN... WATER VAPOR IMAGERY SHOWS RELATIVELY FAST-MOVING SHORTWAVE TROUGH NOW OVER EASTERN MT. THIS FEATURE WILL MOVE EASTWARD ACROSS ND TODAY...WITH ACCOMPANYING COLD FRONT EXTENDING FROM EXTREME NORTHWEST MN INTO CENTRAL SD BY 00Z. THE LOW LEVEL AIR MASS AHEAD OF THE COLD FRONT IS EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS CLIMBING INTO THE 60S AND POCKETS OF HEATING. MODELS ARE IN GENERAL AGREEMENT THAT SCATTERED THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE FRONT OVER EASTERN ND AND SPREAD INTO MN THIS EVENING. VERTICAL SHEAR PROFILES IN THIS REGION WILL BE FAVORABLE FOR SUPERCELLS CAPABLE OF HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY WEAKEN RAPIDLY AS IT MOVES INTO MN DUE TO MORE STABLE AIRMASS. ...NEB/KS... SURFACE WARM FRONT IS SLOWLY RETREATING NORTHWARD ACROSS KS THIS MORNING. THE AIRMASS SOUTH OF FRONT WILL LIKELY BECOME VERY UNSTABLE THIS AFTERNOON WITH TEMPERATURES NEAR 90F AND DEWPOINTS IN THE UPPER 60S. FORECAST SOUNDINGS IN THIS REGION SHOW A DEEP-MIXED BOUNDARY LAYER AND MLCAPE VALUES OF 1000-1500 J/KG. AMPLE MID LEVEL MOISTURE OVER THIS AREA AND CONVERGENCE ALONG WEAK FRONT WILL PROMOTE SCATTERED THUNDERSTORMS THIS AFTERNOON...WITH DAMAGING WINDS POSSIBLE IN STRONGER CELLS. ACTIVITY SHOULD DIMINISH QUICKLY AFTER SUNSET. ...MT/ID... VIGOROUS SHORTWAVE TROUGH IS CURRENTLY MOVING INLAND OVER NORTHERN CA. THIS FEATURE WILL TRACK EAST-NORTHEASTWARD AND AFFECT PORTIONS OF ID/MT THIS AFTERNOON. FORCING FOR LARGE SCALE UPWARD VERTICAL MOTION...ALONG WITH MARGINAL INSTABILITY AND DAYTIME HEATING...WILL HELP INITIATE THUNDERSTORMS OVER THE MOUNTAINS OF CENTRAL ID/WESTERN MT BY EARLY AFTERNOON. STRENGTH OF MID LEVEL WINDS AND INVERTED-V PROFILES WILL ENHANCE THE RISK OF GUSTY/DAMAGING WINDS IN STRONGER CELLS. ...GULF COAST... WEAK UPPER LOW IS MOVING NORTHWESTWARD ACROSS FL THIS MORNING. BAND OF MID LEVEL MOISTURE IS EVIDENT IN WATER VAPOR IMAGERY FROM NORTHERN GA/AL TO THE CENTRAL GULF COAST. THIS REGION WILL LIKELY BECOME MODERATELY UNSTABLE THIS AFTERNOON AS TEMPERATURES WARM WELL INTO THE 90S. SCATTERED THUNDERSTORMS ARE EXPECTED FROM SOUTHEAST LA INTO SOUTHWEST GA AND THE FL PANHANDLE. WET MICROBURSTS WILL BE POSSIBLE WITH MORE INTENSE CELLS. ..HART/LEVIT.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 16:03:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 12:03:39 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161601 SWODY1 SPC AC 161600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 AM CDT WED AUG 16 2006 VALID 161630Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF NRN/CENTRAL ID AND WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ERN ND AND NWRN MN... ...WRN MT AND NRN/CENTRAL ID... TROUGH THAT DEEPENED SEWD INTO PAC NW PAST 24 HOURS IS NOW SHIFTING EWD SPREADING STRONGER FLOW...LARGE SCALE UPWARD MOTION FIELD AND COOLING ALOFT ACROSS NRN ROCKIES TODAY/TONIGHT. SURFACE HIGH DROPPING SEWD SRN PRAIRIE PROVINCES WILL PROVIDE UPSLOPE COMPONENT TO THE LOW LEVEL FLOW ENHANCING THE DEEP LAYER SHEAR PROFILES ACROSS WRN MT. ALTHOUGH THE AVAILABLE MOISTURE AND INSTABILITY WILL BE SOMEWHAT LIMITED AHEAD OF THE TROUGH...COMBINATION OF 40-50 KT OF SHEAR AND STEEP LAPSE RATES SUFFICIENT TO UPGRADE MUCH OF NRN ROCKIES TO A SLIGHT RISK FOR THIS AFTERNOON AND EVENING. WITH OVERNIGHT CONVECTION AND CLOUD COVER CURRENTLY CLEARING OUT OF THE NRN ROCKIES...FULL HEATING WILL RAPIDLY STEEPEN LOW LEVEL LAPSE RATES DURING AFTERNOON WITH THUNDERSTORMS FORMING OVER HIGHER TERRAIN FROM NERN ORE MTNS ACROSS CENTRAL ID INTO WRN MT. THE THREAT OF LARGE HAIL AND DAMAGING DOWNBURSTS WINDS WILL INCREASE BY MID/LATE AFTERNOON WITH MLCAPES UPWARDS TO 1000 J/KG DEVELOPING GIVEN THE STRONG SURFACE HEATING AND COLD ADVECTION ALOFT. ...ND/MN... WATER VAPOR IMAGERY SHOWS RELATIVELY FAST-MOVING SHORTWAVE TROUGH MOVING INTO WRN DAKOTAS. THIS FEATURE WILL MOVE EASTWARD ACROSS ND TODAY...WITH ACCOMPANYING COLD FRONT EXTENDING FROM ERN ND TO SWRN SD BY 00Z. THE LOW LEVEL AIR MASS AHEAD OF THE COLD FRONT IS EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS CLIMBING INTO THE 60S AND POCKETS OF HEATING. SCATTERED THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE FRONT OVER EASTERN ND AND SPREAD INTO MN THIS EVENING. VERTICAL SHEAR PROFILES IN THIS REGION WILL BE FAVORABLE FOR SUPERCELLS CAPABLE OF HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY WEAKEN RAPIDLY OVERNIGHT AS STORMS MOVE INTO MN DUE TO MORE STABLE AIRMASS. ...KS/NE/SD... SLY FLOW RETURNING A MOIST AND POTENTIALLY MODERATELY UNSTABLE AIR MASS NWD THRU THE PLAINS. STRONG HEATING WILL STEEPEN LOW LEVEL LAPSE RATES ACROSS PLAINS THIS AFTERNOON. WITH MLCAPES UPWARDS TO 2000 J/KG...WET MICRO BURSTS ARE POSSIBLE MOST ANYWHERE IN THIS AREA WHERE STRONG STORMS DEVELOP. GENERALLY DEEP LAYER SHEAR LESS THAN 15KTS MUCH OF PLAINS SUPPORT A PULSE MODE FOR CONVECTIVE DEVELOPMENT. ..HALES/GUYER.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 20:05:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 16:05:08 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 162005 SWODY1 SPC AC 162003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT WED AUG 16 2006 VALID 162000Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN OR TO WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/ERN DAKOTAS...NWRN MN... ...SYNOPSIS... PROGRESSIVE NRN STREAM PATTERN CONTINUES...WITH HEIGHT FALLS CONCENTRATED ACROSS NRN ROCKIES ATTM. STRONG MIDDLE-UPPER LEVEL TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER CASCADES -- IS FCST TO MAINTAIN POSITIVE TILT WHILE DRIFTING EWD ACROSS CENTRAL/ERN PORTIONS WA/ORE AND NRN CA. FARTHER DOWNSTREAM...WEAK SHORTWAVE TROUGH EMBEDDED IN SW FLOW ALOFT WILL CONTINUE TO MOVE ENEWD ACROSS ND AND NWRN CORNER OF MN. AT SFC...LOW EVIDENT OVER EXTREME N-CENTRAL ND/SWRN MB ATTM SHOULD WEAKEN AS ASSOCIATED TROUGH MOVES PAST...AND AS ACCOMPANYING COLD FRONT MOVES SEWD OVER ND AND NWRN MN. TRAILING PORTION OF THIS FRONT WILL CONTINUE MOVING SWD OVER CENTRAL/ERN MT...BECOMING QUASISTATIONARY INVOF WY BORDER BY END OF PERIOD AS PRESSURES CONTINUE TO FALL IN WRN WY/SWRN ID. SECOND LOW IS ANALYZED OVER MO RIVER NEAR SD/ND BORDER...WITH WEAK COLD FRONT SWWD INTO SRN BLACK HILLS AND WARM FRONT ENEWD ACROSS SERN ND AND NRN MN. BAROCLINIC ZONES SHOULD MERGE BY LATE TONIGHT AND BECOME NEARLY STATIONARY FROM N-CENTRAL SD TO NRN MN. ...INTERIOR NWRN CONUS...NRN ROCKIES... AIR MASS CONTINUES TO DESTABILIZE ATTM BOTH SFC AND ALOFT. SFC DIABATIC HEATING AND DPVA IN MIDLEVELS ARE RESULTING IN STEEP UNSTABLE DEEP-LAYER LAPSE RATES AMIDST FAVORABLE VERTICAL SHEAR PROFILES...AHEAD OF MID/UPPER LEVEL TROUGH. COVERAGE AND INTENSITY OF TSTMS WILL CONTINUE TO GROW FOR A FEW MORE HOURS AS ACTIVITY INITIALLY OVER ERN ORE AND CENTRAL ID SHIFTS NEWD...WITH ADDITIONAL DEVELOPMENT POSSIBLE SWRN THROUGH W-CENTRAL MT. REF SPC WW 723 AND RELATED MESOSCALE DISCUSSIONS FOR SHORT-TERM DETAILS. SVR POTENTIAL SHOULD DIMINISH AFTER DARK FROM COMBINATION OF DIABATIC SFC COOLING AND INCREASING COVERAGE OF OUTFLOW AIR. ...NRN PLAINS... TSTMS ARE FCST TO DEVELOP AND BECOME SVR OVER PORTIONS CENTRAL/ERN DAKOTAS DURING NEXT SEVERAL HOURS...AS CAP WEAKENS AMIDST STRONG HEATING AND FAVORABLE SFC MOIST AXIS...AHEAD OF SFC FRONT. ADDITIONAL DESTABILIZATION ALOFT MAY BE PROVIDED BY WEAK DPVA/ASCENT ASSOCIATED WITH EJECTING ND SHORTWAVE. DAMAGING GUSTS AND HAIL ARE POSSIBLE. REF SPC MESOSCALE DISCUSSION 1822 FOR NOWCAST INFORMATION. AFTERNOON ACTIVITY MAY PERSIST THROUGH MUCH OF THIS EVENING IN NE-SW ORIENTED BAND MOVING SLOWLY EWD ACROSS ERN DAKOTAS AND PERHAPS NWRN MN. OVERALL SVR THREAT SHOULD DIMINISH GRADUALLY LATE THIS EVENING AND INTO OVERNIGHT HOURS. ..EDWARDS.. 08/16/2006  From swody1 at goshenarc.org Thu Aug 17 01:01:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 21:01:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170100 SWODY1 SPC AC 170059 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0759 PM CDT WED AUG 16 2006 VALID 170100Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS CENTRAL ID AND WESTERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS FAR EASTERN DAKOTAS/NORTHWEST MN... ....ID/MT... WATER VAPOR IMAGERY EARLY THIS EVENING FEATURES POTENT UPPER TROUGH SHIFTING EASTWARD ACROSS ORE/WA. LARGE SCALE ASCENT ASSOCIATED WITH THE FEATURE HAS RESULTED IN A BROAD COVERAGE OF STRONG/OCCASIONALLY SEVERE STORMS ACROSS ID/WESTERN MT SINCE THIS AFTERNOON. WITHIN A STRONGLY SHEARED ENVIRONMENT...BOUNDARY LAYER STABILIZATION VIA CONVECTIVE OUTFLOWS/LOSS OF DAYTIME HEATING WILL TEND TO CURB CONVECTIVE INTENSITY REMAINDER OF THE EVENING IN AN ALREADY WEAKLY UNSTABLE AIRMASS /REFERENCE 00Z GREAT FALLS AND GLASGOW MT RAOBS/. NEVERTHELESS...ISOLATED LARGE HAIL AND STRONG WIND GUSTS WILL REMAIN POSSIBLE TONIGHT AS THUNDERSTORM CLUSTERS SPREAD E/NE ACROSS MT. ...NORTHEAST SD/EASTERN ND/NORTHWEST MN... STRONG/SEVERE THUNDERSTORMS CONTINUE IN VICINITY OF PREFRONTAL TROUGH AND SOUTHWARD MOVING WEAK COLD FRONT ACROSS ND. 00Z OBSERVED ABERDEEN RAOB IS INDICATIVE OF THE MODERATELY UNSTABLE/ADEQUATELY SHEARED AIRMASS ACROSS THE FAR EASTERN DAKOTAS/NORTHWEST MN...WHICH REMAINS FAVORABLE FOR SUPERCELLS WITH A PRIMARY HAZARD OF LARGE HAIL. AN ISOLATED TORNADO MAY REMAIN POSSIBLE OVER THE NEXT HOUR OR TWO GIVEN THE BACKED SOUTHEASTERLY LOW LEVEL FLOW/INCREASING LOW LEVEL JET AND A SUFFICIENTLY MOIST AIRMASS. WITH THE SOUTHERN EXTENT ACROSS SOUTHEAST ND/NORTHEAST SD LARGELY TIED TO THE DIURNAL CYCLE...THE MOST SUSTAINED ACTIVITY IS LIKELY TO PERSIST ACROSS NORTHWEST MN AS SHORTWAVE TROUGH SPREADS EAST OF THE SURFACE TROUGH/INSTABILITY AXIS. CONSULT WW 724 AND RELATED MESOSCALE DISCUSSIONS FOR THE LATEST DETAILS REMAINDER OF THE NIGHT. ...SOUTHERN LA/FAR SOUTHEAST TX... WITH THE THUNDERSTORM COMPLEX SPREADING WEST ACROSS THE SABINE RIVER EARLY THIS EVENING...LOSS OF DAYTIME HEATING AND STABILIZING AFFECTS OF CONVECTIVE OUTFLOWS WILL LEAD TO A DIMINISHING MICROBURST/HAIL THREAT. ..GUYER/KERR.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 05:47:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 01:47:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170547 SWODY1 SPC AC 170546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT THU AUG 17 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN/TONIGHT ACROSS PARTS OF THE NORTHERN PLAINS.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVE ACROSS PARTS OF THE CNTRL PLAINS/MID MS VLY.... SUBTROPICAL RIDGE ENCOMPASSING MUCH OF THE CENTRAL AND SOUTHERN TIER OF THE U.S. WILL REMAIN STRONG THROUGH MUCH OF THIS FORECAST PERIOD. HOWEVER...WEAKENING OF THIS FEATURE MAY COMMENCE TOWARD THE END OF THE PERIOD ...AS A SIGNIFICANT SHORT WAVE TROUGH... EMBEDDED WITHIN A BELT OF STRONGER WESTERLIES ACROSS CANADA... FINALLY SHIFTS EAST OF SASKATCHEWAN/MANITOBA. THIS SYSTEM WILL BE TRAILED CLOSELY BY A SHORT WAVE TROUGH IN A WEAKER SOUTHERN STREAM...ACROSS THE NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES AND NORTHERN PLAINS. ADDITIONALLY...WEAK BROAD TROUGHING IN THE SUBTROPICAL WESTERLIES IS FORECAST TO CONTINUE AROUND THE NORTHERN PERIPHERY OF THE UPPER RIDGE...PROGRESSING EAST OF THE MID MISSOURI VALLEY THROUGH THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION. SEVERAL OTHER IMPULSES WILL MIGRATE THROUGH THE ANTICYCLONIC FLOW AROUND THE OZARK PLATEAU SUBTROPICAL HIGH CENTER...FROM THE SOUTHERN ROCKIES INTO THE CENTRAL PLAINS...AND ACROSS THE GULF STATES. ALL OF THESE FEATURES...IN CONJUNCTION WITH SEASONABLE INSTABILITY ...WILL CONTRIBUTE TO SCATTERED THUNDERSTORM ACTIVITY TODAY/TONIGHT. MUCH OF THE COUNTRY WILL BE AFFECTED...WITH THE MOST NOTABLE EXCEPTIONS THE NORTHEAST...STILL UNDER THE INFLUENCE OF RECENT COOL/DRY INTRUSION...AND THE PACIFIC COAST STATES/GREAT BASIN...ASSOCIATED WITH DRYING TO THE SOUTH/WEST OF NORTHERN INTERMOUNTAIN TROUGH. ...CENTRAL PLAINS INTO MID MISSISSIPPI VALLEY... IN THE WAKE OF THE SUBTROPICAL IMPULSE...A CONFLUENT LOW/MID-LEVEL FLOW REGIME WITH A BELT OF 20 TO 30+ KT FLOW IS EXPECTED TO PERSIST FROM PARTS OF NORTHERN KANSAS ACROSS THE MISSOURI/IOWA BORDER AREA THROUGH MUCH OF THE DAY. THIS WILL AID FORWARD PROPAGATION OF CONVECTIVE DEVELOPMENT...WHICH IS EXPECTED TO INITIATE IN A WARM ADVECTION REGIME ALONG/NORTH OF A LOW-LEVEL THERMAL RIDGE AXIS...MOST LIKELY NEAR/SHORTLY AFTER PEAK AFTERNOON HEATING. A HOT...DEEP MIXED BOUNDARY LAYER ON THE SOUTHERN FRINGE OF A SUBTROPICAL MOISTURE PLUME SHOULD PROVE FAVORABLE FOR DOWNBURSTS...AND POTENTIALLY DAMAGING SURFACE GUSTS...WHICH COULD BECOME FAIRLY NUMEROUS BEFORE STORMS WEAKEN WITH LOSS OF HEATING THIS EVENING. ...NORTHERN PLAINS... FAVORABLE OROGRAPHY NEAR THE BLACK HILLS MAY PROVIDE THE LONE/ PRIMARY FORCING TO SUPPORT CONVECTIVE PRIOR TO 22-23Z TODAY...AS WARM MID-LEVEL TEMPERATURES PROVIDE SUBSTANTIAL CAP. IF ACTIVITY DOES DEVELOP...MODERATELY STRONG SOUTHWESTERLY MID-LEVEL FLOW WILL CONTRIBUTE TO FAVORABLE SHEAR FOR ISOLATED SUPERCELLS IN AN ENVIRONMENT WITH STEEP MID-LEVEL LAPSE RATES AND CAPE AROUND 2000 J/KG. THEREAFTER...INCREASING LARGE-SCALE ASCENT ASSOCIATED WITH THE APPROACH OF UPPER TROUGH/STRENGTHENING SOUTHERLY LOW-LEVEL JET MAY SUPPORT INCREASING CONVECTIVE DEVELOPMENT ALONG A SURFACE FRONT... EXTENDING ACROSS NORTHERN SOUTH DAKOTA INTO VICINITY OF SURFACE LOW TO THE LEE OF THE NORTH CENTRAL ROCKIES. ACTIVITY PROBABLY WILL INITIATE IN THE MOIST POST-FRONTAL UPSLOPE FLOW REGIME ACROSS SOUTHEAST MONTANA/PARTS OF NORTHEAST WYOMING...AND COULD CONSOLIDATE INTO AN ORGANIZED CONVECTIVE CLUSTER EASTWARD ALONG FRONT TONIGHT. IF THIS OCCURS...THERMODYNAMIC PROFILES FAVORABLE FOR EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...AND DOWNBURSTS/SURFACE COLD POOL DEVELOPMENT...WILL SUPPORT POTENTIAL FOR DAMAGING WIND GUSTS. LARGE HAIL IS ALSO POSSIBLE. ..KERR/BOTHWELL.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 12:49:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 08:49:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171249 SWODY1 SPC AC 171248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT THU AUG 17 2006 VALID 171300Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN MT ACROSS PARTS OF THE DAKOTAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF KS...NEB...IA...AND MO... ...NORTHERN PLAINS... ZONAL FLOW PATTERN WILL PERSIST ACROSS THE NORTHERN U.S. TODAY... WITH SERIES OF SHORTWAVE TROUGHS MOVING FROM THE NORTHERN ROCKIES TO THE GREAT LAKES. ONE STRONG TROUGH IS CURRENTLY OVER PARTS OF ORE/ID...AND IS FORECAST TO TRACK EASTWARD ACROSS MT THIS AFTERNOON AND EVENING. THE AIRMASS OVER THE NORTHERN PLAINS /EASTERN MT INTO ND/ WILL REMAIN QUITE MOIST TODAY JUST NORTH OF SURFACE BAROCLINIC ZONE. POCKETS OF AFTERNOON HEATING IN THIS AREA...COUPLED WITH EASTERLY/UPSLOPE FLOW WILL HELP TO INITIATE AFTERNOON THUNDERSTORMS OVER THE BLACK HILLS AND BIGHORN MTNS OF MT/WY/SD. VERTICAL SHEAR PROFILES IN THIS AREA WILL PROMOTE SUPERCELL STRUCTURES CAPABLE OF HAIL AND DAMAGING WINDS. LIMITED FORCING FOR UPWARD VERTICAL MOTION WILL LIKELY LIMIT AREAL COVERAGE OF THUNDERSTORMS UNTIL AFTER DARK. DURING THE EVENING...UPPER TROUGH WILL APPROACH FROM THE WEST. STRONGER FORCING WILL OVERSPREAD WESTERN EDGE OF DEEPER LOW LEVEL MOISTURE OVER SOUTHEAST MT AND NORTHEAST WY. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THIS AREA AND PROPAGATE EASTWARD INTO PARTS OF THE DAKOTAS OVERNIGHT. CAPE/SHEAR PARAMETERS AND STRENGTH OF UPPER FORCING SUGGEST THAT SUPERCELLS/BOWS WILL BE POSSIBLE THROUGHOUT THE NIGHT WITH DAMAGING WINDS AND HAIL IN STRONGER STORMS. ...KS/NEB/IA/MO... WEAK SURFACE BOUNDARY CURRENTLY EXTENDS FROM SOUTH CENTRAL NEB INTO MO. THIS BOUNDARY IS FORECAST TO LIFT NORTHWARD TODAY...WITH MOIST/UNSTABLE AIRMASS SOUTH OF FRONT SPREADING ACROSS MUCH OF NEB/IA. STRONG DAYTIME HEATING WILL LEAD TO STEEP LOW LEVEL LAPSE RATES AND MODERATE INSTABILITY /MLCAPE VALUES OVER 2500 J/KG/. MORNING WATER VAPOR IMAGERY SHOWS PLUME OF MID LEVEL MOISTURE FROM THE TX PANHANDLE INTO SOUTHEAST NEB. COMBINATION OF CONVERGENCE NEAR RETREATING BOUNDARY...FAVORABLE MID LEVEL MOISTURE...AND FULL SUNSHINE WILL HELP TO INITIATE THUNDERSTORMS FROM EASTERN KS/NEB INTO WESTERN IA/MO THIS AFTERNOON. THESE STORMS MAY MOVE AS FAR EAST AS THE MISSISSIPPI RIVER THIS EVENING BEFORE WEAKENING. LOCALLY GUSTY/DAMAGING WINDS ARE EXPECTED IN STRONGER STORMS. ..HART/LEVIT.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 16:12:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 12:12:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171610 SWODY1 SPC AC 171608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1108 AM CDT THU AUG 17 2006 VALID 171630Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS NERN WY/SERN MT EWD ACROSS SD AND SRN ND...... ...SERN MT/NRN WY EWD ACROSS DAKOTAS... COLD UPPER TROUGH CURRENTLY CROSSING NRN ROCKIES PRECEEDED BY MODERATE SWLY FLOW AT MID LEVELS ACROSS NRN PLAINS. OVERNIGHT A COLD FRONT MOVED EWD ACROSS ND AND CURRENTLY EXTENDS FROM NWRN MN SWWD TO BLACK HILLS AND WWD ACROSS NRN WY. SURFACE LOW CENTRAL WY SHIFTS EWD INTO SWRN SD BY EVENING WITH NELY FLOW ALLOWING LOW LEVEL MOISTURE TO SPREAD INTO BIG HORN BASIN AND NERN WY. SURFACE HEATING COUPLED WITH THE UPSLOPE FLOW TO NORTH OF FRONTAL ZONE WILL SUPPORT STRONG/SEVERE THUNDERSTORM DEVELOPMENT FROM BIG HORN BASIN ENEWD ACROSS NERN WY/SERN MT INTO NWRN SD/SWRN ND BY MID/LATE AFTERNOON. SHEAR PROFILES WILL INCREASE TOWARD EVENING AS UPPER TROUGH APPROACHES AND LOW LEVEL JET TO S OF FRONTAL ZONE ACROSS NRN HIGH PLAINS INCREASES TO 25-30KT. SUPERCELLS WILL BECOME MORE LIKELY BY EVENING WITH THE INCREASINGLY FAVORABLE SHEAR AND UPWARD MOTION AHEAD OF THE APPROACHING TROUGH. PRIMARY THREAT WILL BE LARGE HAIL EARLY IN STORM EVOLUTION. DAMAGING WINDS WILL BECOME MORE LIKELY TOWARD EVENING AS STORMS DEVELOP UPSCALE INTO POSSIBLE MCS AND SHORT LINES. ANY TORNADO THREAT WITH SUPERCELLS SHOULD BE BRIEF AS BASES WILL BE RELATIVELY HIGH AND MLCAPES LIKELY NOT MUCH ABOVE 1500 J/KG. THREAT OF AT LEAST DAMAGING WINDS EXPECTED TO CONTINUE WELL AFTER DARK ACROSS DAKOTAS GIVEN THE UPPER WIND MAX TRANSLATING EWD ALONG ND/CANADA BORDER. ..HALES/GUYER.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 20:04:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 16:04:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 172004 SWODY1 SPC AC 172002 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0302 PM CDT THU AUG 17 2006 VALID 172000Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN HIGH PLAINS AND INTO THE DAKOTAS... ...SERN MT/NERN WY INTO THE DAKOTAS... CUMULUS DEVELOPMENT CONTINUES ACROSS THE BLACK HILLS...WHERE STRONG BOUNDARY-LAYER HEATING IS RESULTING IN CONTINUED DESTABILIZATION /1000 TO 1500 J/KG MEAN-LAYER CAPE/. CAPPING INVERSION S OF W-E BAROCLINIC ZONE OVER SD SHOULD CONTINUE TO INHIBIT WARM-SECTOR CONVECTION. HOWEVER...STORMS SHOULD DEVELOP OVER THE BLACK HILLS -- AS WELL AS NEAR AND N OF SURFACE FRONT FROM NRN WY EWD INTO CENTRAL SD THIS AFTERNOON AND EVENING. AS LOW-LEVEL JET DEVELOPS THIS EVENING ACROSS THE HIGH PLAINS...STORMS SHOULD INCREASE IN COVERAGE -- AND POSSIBLY EVOLVE INTO ONE OR MORE MCS. THOUGH DEEP-LAYER SHEAR REMAINS LIMITED S OF FRONT...ELY LOW-LEVEL FLOW N OF FRONT COMBINED WITH INCREASE IN FLOW ALOFT AS UPPER TROUGH APPROACHES WILL YIELD SHEAR SUPPORTIVE OF SUPERCELLS. ALONG WITH THREAT FOR LARGE HAIL...LOCALLY-DAMAGING WINDS WILL ALSO BE POSSIBLE -- PARTICULARLY IF STORMS ORGANIZE ON THE MESOSCALE AS WARM ADVECTION INCREASES THIS EVENING. SEVERE THREAT APPEARS TO EXTEND WWD INTO NRN WY AND SWD ACROSS ERN WY...THOUGH LESS UNSTABLE AIRMASS SHOULD ACT TO LIMIT STORM INTENSITY. ..GOSS.. 08/17/2006  From swody1 at goshenarc.org Fri Aug 18 00:55:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 20:55:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180054 SWODY1 SPC AC 180053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT THU AUG 17 2006 VALID 180100Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NORTHERN PLAINS.... ...NORTHERN PLAINS... AN UPPER TROUGH IS BECOMING INCREASINGLY SHEARED AS IT ACCELERATES EASTWARD OUT OF THE NORTHERN INTERMOUNTAIN REGION. THIS IS OCCURRING AS A MORE SIGNIFICANT SHORT WAVE TROUGH...EMBEDDED WITHIN THE MAIN BELT OF WESTERLIES ACROSS CANADA...PROGRESSES EASTWARD INTO HUDSON BAY/ONTARIO. SURFACE FRONT ASSOCIATED WITH THE LATTER FEATURE IS ADVANCING INTO THE UPPER MISSISSIPPI VALLEY...BUT THE BOUNDARY HAS STALLED ACROSS PARTS OF NORTHERN SOUTH DAKOTA INTO NORTHEAST WYOMING...AWAITING THE APPROACH OF UPSTREAM SYSTEM. AS LARGE-SCALE UPWARD VERTICAL MOTION FIELD STRENGTHENS ALONG/JUST NORTH OF FRONT ACROSS NORTHWESTERN SOUTH DAKOTA THIS EVENING...POTENTIAL STILL EXISTS FOR THE DEVELOPMENT OF AN ORGANIZING MESOSCALE CONVECTION SYSTEM WITH RISK FOR DAMAGING WINDS/LARGE HAIL. VERTICAL SHEAR PROFILES ALONG FRONT ARE STRONG...VEERING FROM EASTERLY AT LOW-LEVELS TO MODERATELY STRONG WESTERLY AT MID/UPPER LEVELS...AND STEEP MID-LEVEL LAPSE RATES WILL MAINTAIN MOST UNSTABLE CAPE ON THE ORDER OF 1000-2000 J/KG. THIS MAY BE SUPPORTIVE OF SUPERCELL STRUCTURES BEFORE CONVECTION CONSOLIDATES LATER THIS EVENING/OVERNIGHT...GRADUALLY SPREADING EASTWARD ALONG FRONT ACROSS NORTHERN/CENTRAL SOUTH DAKOTA. ...CENTRAL PLAINS INTO MIDDLE MISSISSIPPI VALLEY... REMNANT BOUNDARY LEFT IN THE WAKE OF A SUBTROPICAL SHORT WAVE TROUGH... WHICH HAS SHIFTED EAST OF UPPER PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY INTO THE SOUTHERN GREAT LAKES REGION...IS BECOMING A FOCUS FOR INCREASING CONVECTIVE DEVELOPMENT ACROSS NORTHERN KANSAS...NEAR INTERSTATE 70. ACTIVITY SEEMS LIKELY TO PERSIST TONIGHT...PERHAPS AIDED BY FORCING ASSOCIATED WITH ANOTHER WEAK IMPULSE MIGRATING AROUND WESTERN/NORTHWESTERN PERIPHERY OF MID SOUTH SUBTROPICAL RIDGE. AND...DEVELOPMENT IS EXPECTED TO GRADUALLY SHIFT EAST NORTHEASTWARD THROUGH PARTS OF NORTHERN MISSOURI/SOUTHERN IOWA BY LATE TONIGHT...AS SOUTHERLY CENTRAL PLAINS LOW-LEVEL JET GRADUALLY VEERS. ALTHOUGH TIMING IS NOT OPTIMAL WITH THE ONSET OF DIURNAL BOUNDARY LAYER COOLING...UNSATURATED LOWER/MID-LEVEL PROFILES WILL ALLOW SUBSTANTIAL EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...CONTRIBUTING TO POTENTIAL FOR DOWNBURSTS AND AT LEAST A LOCALIZED DAMAGING WIND THREAT. ..KERR.. 08/18/2006  From swody1 at goshenarc.org Fri Aug 18 05:41:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 18 Aug 2006 01:41:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180540 SWODY1 SPC AC 180539 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1239 AM CDT FRI AUG 18 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... SUBTROPICAL RIDGING WILL PERSIST ACROSS MUCH OF THE CENTRAL AND SOUTHERN TIER OF THE U.S. THROUGH THIS FORECAST PERIOD. HOWEVER...MODELS INDICATE THAT THE OZARK PLATEAU/MID SOUTH HIGH CENTER WILL GRADUALLY BEGIN TO BREAK DOWN/WEAKEN...IN RESPONSE TO THE PROGRESSION OF SHORT WAVE TROUGHS IN FASTER FLOW TO THE NORTH...AND ASSOCIATED INTRUSIONS OF COOLER AIR INTO THE NORTH CENTRAL STATES. THE MOST PROMINENT OF THESE SHORT WAVES...EMBEDDED WITHIN THE STRONGER BELT OF WESTERLIES ACROSS CANADA...IS PROGGED CONTINUE EAST OF HUDSON BAY/ONTARIO TODAY...WITH ANOTHER SYSTEM CONTINUING INLAND EAST OF THE CANADIAN ROCKIES. AS THIS OCCURS...AN INCREASINGLY SHEARED SHORT WAVE TROUGH IN A WEAKER SOUTHERN BRANCH OF POLAR WESTERLIES...IS PROGGED TO ADVANCE ACROSS THE NORTHERN PLAINS...AND INTO THE UPPER GREAT LAKES REGION BY EARLY SATURDAY MORNING. ...CENTRAL STATES... CONSIDERABLY COMPLICATING MATTERS...CONCERNING SEVERE POTENTIAL DURING THIS FORECAST PERIOD...IS SERIES OF WEAK IMPULSES EMBEDDED WITHIN SUBTROPICAL MOIST PLUME ADVECTING AROUND UPPER HIGH CENTER. MODELS SUGGEST THAT A CONVECTIVELY GENERATED/ENHANCED SURFACE BOUNDARY ASSOCIATED WITH THIS STREAM...LIKELY OVER NORTHERN KANSAS/NORTHERN MISSOURI AT THE OUTSET OF THE PERIOD...WILL ADVANCE SOUTHWARD INTO/THROUGH THE OZARKS/CENTRAL PLAINS DURING THE DAY. THIS MOVEMENT...INTO AREAS WELL SOUTH OF STRONGER FLOW ASSOCIATED WITH THE WESTERLIES...IS FORECAST TO OCCUR AS A SIGNIFICANT IMPULSE SHIFTS EAST OF THE MID/LOWER MISSOURI VALLEY TOWARD THE LOWER OHIO VALLEY. LOW-LEVEL CONVERGENCE WILL BECOME FOCUSED ALONG THIS BOUNDARY...WITH STRONGER SURFACE HEATING AND STEEPER LAPSE RATES BECOMING CONFINED TO AREAS TO THE SOUTH AND WEST...ACROSS MUCH OF KANSAS/SOUTHERN MISSOURI. DESPITE WEAK SHEAR AND UNCERTAIN MID/UPPER FORCING...MIXED LAYER CAPE IN EXCESS OF 2000 J/KG MAY SUPPORT SCATTERED VIGOROUS STORMS AS INHIBITION WEAKENS IN PEAK AFTERNOON HEATING ALONG/SOUTH OF BOUNDARY. LOCALIZED DOWNBURSTS WILL BE POSSIBLE IN STRONGER CONVECTION...BUT POTENTIAL FOR A SIGNIFICANT CONVECTIVE CLUSTER WITH BROADER SCALE DAMAGING WIND POTENTIAL SEEMS SMALL. ELSEWHERE...AHEAD OF UPPER IMPULSE...SCATTERED THUNDERSTORM ACTIVITY SEEMS LIKELY TO DEVELOP FROM PARTS OF THE MIDDLE MISSISSIPPI INTO THE LOWER OHIO VALLEY LATE THIS AFTERNOON. SHEAR WILL BE LIMITED...AND SURFACE HEATING/DESTABILIZATION NOT AS STRONG AS AREAS FARTHER WEST...BUT HIGH PRECIPITABLE WATER CONTENT OF AIR WILL BE FAVORABLE FOR LOCALLY HEAVY DOWNPOURS...PERHAPS LOCALIZED DOWNBURSTS. OTHER STRONG/LOCALLY SEVERE STORMS COULD OCCUR NEAR FRONTAL ZONE ASSOCIATED WITH SOUTHERN BRANCH TROUGH MIGRATING ACROSS THE NORTH CENTRAL STATES. THIS SEEMS MOST LIKELY EARLY IN THE DAY ACROSS PARTS OF SOUTHERN SOUTH DAKOTA/NORTHERN NEBRASKA...BEFORE LOW-LEVEL CONVERGENCE WEAKENS AS PRE-FRONTAL LOW-LEVEL FLOW VEERS TO A PROGGED NORTHERLY COMPONENT. ..KERR/BOTHWELL.. 08/18/2006  From swody1 at goshenarc.org Tue Aug 22 13:03:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 09:03:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221302 SWODY1 SPC AC 221300 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 AM CDT TUE AUG 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS... ...NRN PLAINS... AN UPPER-LEVEL DISTURBANCE ON WATER VAPOR IMAGERY OVER SW MT WILL MOVE INTO THE NRN PLAINS TODAY. IN RESPONSE TO THE DEVELOPING SHORTWAVE TROUGH...A 35-40 KT LOW-LEVEL JET IS FORECAST TO STRENGTHEN ACROSS SD RESULTING IN STRONG MOISTURE ADVECTION. THIS WILL HELP MOVE A WARM FRONT NEWD ACROSS ERN SD INTO WRN MN AS A DRY SLOT ADVECTS NEWD INTO SWRN SD. THE MOIST AXIS WITH 60 TO 65 F SFC DEWPOINTS SHOULD SET UP FROM SRN ND EXTENDING SEWD INTO NE SD AND SWRN MN. MODERATE INSTABILITY APPEARS LIKELY TO DEVELOP ALONG THE MOIST AXIS BY AFTERNOON. HOWEVER...THE LOCATION AND TIMING OF THUNDERSTORM INITIATION REMAINS HIGHLY UNCERTAIN. IT IS POSSIBLE THAT THUNDERSTORMS WILL INITIATE LATE THIS AFTERNOON ALONG THE WARM FRONT IN SCNTRL ND WHERE THE CAPPING INVERSION IS FORECAST TO BE WEAKER. EVEN THOUGH WARM AIR ALOFT WILL BE IN PLACE BEHIND THE DRY SLOT ACROSS SWRN SD...ISOLATED THUNDERSTORMS STILL MAY DEVELOP IN THE HIGHER TERRAIN OF THE BLACK HILLS. THE GREATEST POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS LIKELY TO OCCUR IN NE SD...SE ND AND WRN MN ALONG THE MOIST AXIS AFTER DARK AS THE LOW-LEVEL JET RAPIDLY STRENGTHENS THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS EVENING STRONGLY INCREASE DEEP LAYER SHEAR AS THE SHORTWAVE TROUGH APPROACHES. THIS SHOULD MAKE SUPERCELL DEVELOPMENT INCREASINGLY LIKELY AS STORM COVERAGE INCREASES THIS EVENING. THE POTENTIAL FOR SUPERCELLS APPEARS MOST LIKELY IN A CORRIDOR FROM NEAR FARGO ND EXTENDING EWD TO NEAR MINNEAPOLIS MN LATE THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF PRODUCING LARGE HAIL DUE TO THE STRONG DIRECTIONAL SHEAR AND STEEP MID-LEVEL LAPSE RATES IN PLACE. IN ADDITION...LOW-LEVEL SHEAR PROFILES WILL BE STRONG DUE TO THE LOW-LEVEL JET AND SUPERCELLS THAT BECOME ROOTED IN THE BOUNDARY LAYER MAY HAVE AN ISOLATED TORNADO POTENTIAL. WIND DAMAGE MAY ALSO OCCUR WITH CONVECTION THAT BECOMES SFC-BASED. ...COASTAL CAROLINAS... LATEST ANALYSIS SHOWS A NEARLY STATIONARY FRONT LOCATED ACROSS NRN NC WITH A SFC LOW IN THE MTNS OF WRN NC. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE LOWER 70S F AND THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP ACROSS THE ERN CAROLINAS BY MIDDAY. AS AN UPPER-LEVEL TROUGH MOVES EWD FROM THE SRN APPALACHIAN MTNS INTO THE COASTAL PLAINS LATE THIS AFTERNOON...SCATTERED STRONG THUNDERSTORMS APPEAR POSSIBLE. AS THE UPPER-TROUGH APPROACHES...VERTICAL SHEAR PROFILES SHOULD INCREASE JUST ENOUGH FOR STRONG AND POSSIBLE A FEW MARGINALLY SEVERE MULTICELLS. THE MAIN THREAT WOULD BE WIND DAMAGE DUE TO THE UNIDIRECTIONAL WIND PROFILES IN PLACE. ...ARIZONA... LATEST ANALYSIS SHOWS A MOIST AXIS IN PLACE ACROSS SRN AND CNTRL AZ WHERE DEWPOINTS ARE IN THE 60S F. AS SFC HEATING TAKES PLACE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG THE MOGOLLON RIM. CONVECTIVE COVERAGE WILL LIKELY BE THE GREATEST THIS EVENING AS STORMS MOVE WSWWD ACROSS SRN AND CNTRL AZ. STEEP LOW-LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW DAMAGING WIND GUSTS WITH THE STRONGER CELLS. ...UPSTATE NY/NH/VT/MAINE... A COLD FRONT WILL MOVE SEWD INTO THE NERN U.S. TODAY PROVIDING A FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT. STEEP LAPSE RATES ARE FORECAST TO BE IN PLACE AHEAD OF THE FRONT WHICH COMBINED WITH SFC HEATING MAY BE ENOUGH FOR A FEW STRONG WIND GUSTS WITH THE MORE ORGANIZED STORMS THIS AFTERNOON. ..BROYLES/GUYER.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 13:14:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 09:14:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221312 SWODY1 SPC AC 221311 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 AM CDT TUE AUG 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS... CORRECTED TO ADD 5 % HAIL LINE IN NRN PLAINS ...NRN PLAINS... AN UPPER-LEVEL DISTURBANCE ON WATER VAPOR IMAGERY OVER SW MT WILL MOVE INTO THE NRN PLAINS TODAY. IN RESPONSE TO THE DEVELOPING SHORTWAVE TROUGH...A 35-40 KT LOW-LEVEL JET IS FORECAST TO STRENGTHEN ACROSS SD RESULTING IN STRONG MOISTURE ADVECTION. THIS WILL HELP MOVE A WARM FRONT NEWD ACROSS ERN SD INTO WRN MN AS A DRY SLOT ADVECTS NEWD INTO SWRN SD. THE MOIST AXIS WITH 60 TO 65 F SFC DEWPOINTS SHOULD SET UP FROM SRN ND EXTENDING SEWD INTO NE SD AND SWRN MN. MODERATE INSTABILITY APPEARS LIKELY TO DEVELOP ALONG THE MOIST AXIS BY AFTERNOON. HOWEVER...THE LOCATION AND TIMING OF THUNDERSTORM INITIATION REMAINS HIGHLY UNCERTAIN. IT IS POSSIBLE THAT THUNDERSTORMS WILL INITIATE LATE THIS AFTERNOON ALONG THE WARM FRONT IN SCNTRL ND WHERE THE CAPPING INVERSION IS FORECAST TO BE WEAKER. EVEN THOUGH WARM AIR ALOFT WILL BE IN PLACE BEHIND THE DRY SLOT ACROSS SWRN SD...ISOLATED THUNDERSTORMS STILL MAY DEVELOP IN THE HIGHER TERRAIN OF THE BLACK HILLS. THE GREATEST POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS LIKELY TO OCCUR IN NE SD...SE ND AND WRN MN ALONG THE MOIST AXIS AFTER DARK AS THE LOW-LEVEL JET RAPIDLY STRENGTHENS THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS EVENING STRONGLY INCREASE DEEP LAYER SHEAR AS THE SHORTWAVE TROUGH APPROACHES. THIS SHOULD MAKE SUPERCELL DEVELOPMENT INCREASINGLY LIKELY AS STORM COVERAGE INCREASES THIS EVENING. THE POTENTIAL FOR SUPERCELLS APPEARS MOST LIKELY IN A CORRIDOR FROM NEAR FARGO ND EXTENDING EWD TO NEAR MINNEAPOLIS MN LATE THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF PRODUCING LARGE HAIL DUE TO THE STRONG DIRECTIONAL SHEAR AND STEEP MID-LEVEL LAPSE RATES IN PLACE. IN ADDITION...LOW-LEVEL SHEAR PROFILES WILL BE STRONG DUE TO THE LOW-LEVEL JET AND SUPERCELLS THAT BECOME ROOTED IN THE BOUNDARY LAYER MAY HAVE AN ISOLATED TORNADO POTENTIAL. WIND DAMAGE MAY ALSO OCCUR WITH CONVECTION THAT BECOMES SFC-BASED. ...COASTAL CAROLINAS... LATEST ANALYSIS SHOWS A NEARLY STATIONARY FRONT LOCATED ACROSS NRN NC WITH A SFC LOW IN THE MTNS OF WRN NC. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE LOWER 70S F AND THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP ACROSS THE ERN CAROLINAS BY MIDDAY. AS AN UPPER-LEVEL TROUGH MOVES EWD FROM THE SRN APPALACHIAN MTNS INTO THE COASTAL PLAINS LATE THIS AFTERNOON...SCATTERED STRONG THUNDERSTORMS APPEAR POSSIBLE. AS THE UPPER-TROUGH APPROACHES...VERTICAL SHEAR PROFILES SHOULD INCREASE JUST ENOUGH FOR STRONG AND POSSIBLE A FEW MARGINALLY SEVERE MULTICELLS. THE MAIN THREAT WOULD BE WIND DAMAGE DUE TO THE UNIDIRECTIONAL WIND PROFILES IN PLACE. ...ARIZONA... LATEST ANALYSIS SHOWS A MOIST AXIS IN PLACE ACROSS SRN AND CNTRL AZ WHERE DEWPOINTS ARE IN THE 60S F. AS SFC HEATING TAKES PLACE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG THE MOGOLLON RIM. CONVECTIVE COVERAGE WILL LIKELY BE THE GREATEST THIS EVENING AS STORMS MOVE WSWWD ACROSS SRN AND CNTRL AZ. STEEP LOW-LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW DAMAGING WIND GUSTS WITH THE STRONGER CELLS. ...UPSTATE NY/NH/VT/MAINE... A COLD FRONT WILL MOVE SEWD INTO THE NERN U.S. TODAY PROVIDING A FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT. STEEP LAPSE RATES ARE FORECAST TO BE IN PLACE AHEAD OF THE FRONT WHICH COMBINED WITH SFC HEATING MAY BE ENOUGH FOR A FEW STRONG WIND GUSTS WITH THE MORE ORGANIZED STORMS THIS AFTERNOON. ..BROYLES.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 16:31:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 12:31:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221630 SWODY1 SPC AC 221629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CDT TUE AUG 22 2006 VALID 221630Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN PLAINS... ...NRN PLAINS... PRESSURE FALLS WILL CONTINUE ACROSS THE NRN PLAINS TODAY AS SHORTWAVE TROUGHS TOP UPPER RIDGE AND SHIFT SEWD TOWARDS THE NRN MS RIVER VALLEY TONIGHT. THIS WILL ALLOW A WARM FRONT TO BECOME BETTER DEFINED FROM PORTIONS OF THE NRN MS RIVER VALLEY INTO THE UPPER MO RIVER VALLEY TODAY...WITH A WEAK LOW CENTER LIKELY EVOLVING INTO SWRN ND/NWRN SD/SERN MT. WARM SECTOR AIR MASS WILL BE MOISTENING THROUGH THE DAY WITH LOWER TO MID 60F SURFACE DEW POINTS POSSIBLE INTO SD BY THE LATE AFTERNOON. WITH STRONG SURFACE HEATING AND INCREASING ASCENT AHEAD OF WEAK SHORTWAVE TROUGH AND ALONG NOSE OF STRENGTHENING SSWLY LLJ...POTENTIAL FOR INITIATION WILL INCREASE LATER TODAY NEAR THE SURFACE FRONT. FORECAST SOUNDINGS INDICATE MLCAPE WILL EXCEED 2000 J/KG WITH WEAKENING CINH BY 21Z ALONG AND JUST SOUTH OF SURFACE WARM FRONT INTO N-CENTRAL SD/S-CENTRAL ND...WITH SUFFICIENT WNWLY FLOW ALOFT FOR 35-45 KT EFFECTIVE SHEAR. APPEARS ANY DIURNAL DEVELOPMENT WILL THEREFORE OCCUR WITHIN A FAVORABLE ENVIRONMENT FOR SURFACE-BASED SUPERCELLS INTO THE EVENING. EXPECT OVERALL INCREASE/EVOLUTION INTO A MCS ALONG NOSE OF STRENGTHENING LLJ THROUGH THE EVENING/OVERNIGHT NORTH OF THE SURFACE FRONT INTO PORTIONS OF ERN ND/NERN SD WHICH WILL SPREAD ESEWD INTO CENTRAL MN LATER TONIGHT. APPEARS THIS ACTIVITY WILL REMAIN ELEVATED...THOUGH STEEP MID LEVEL LAPSE RATES AND INFUSION OF 10-12C H85 DEW POINTS SHOULD SUSTAIN MODERATE MUCAPE. STRONG EFFECTIVE SHEAR IN EXCESS OF 45 KT WILL ALSO FAVOR ELEVATED SUPERCELLS AND ORGANIZED CLUSTERS/LINES...FURTHER INCREASING THE POTENTIAL FOR LARGE HAIL. DAMAGING WIND THREAT LATER TONIGHT WILL DEPEND ON DEGREE OF BOUNDARY LAYER STABILIZATION...THOUGH ISOLATED DAMAGING WINDS MAY OCCUR. ..EVANS/TAYLOR.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 19:58:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 15:58:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221957 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT TUE AUG 22 2006 VALID 222000Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE DAKOTAS AND CNTRL/SRN MN... ...DAKOTAS TO MN... STRONG WARM AIR ADVECTION AND DESTABILIZATION WERE UNDERWAY BENEATH STOUT WARM SECTOR CAPPING ACROSS SD ATTM. SURFACE WARM FRONT WAS RECENTLY ANALYZED BISECTING SD FROM NW TO SE WITH LATEST DIAGNOSTIC DATA INDICATING MLCAPE IN EXCESS OF 2000 J/KG ALONG AND SOUTH OF THE FRONT. WHILE SUBTLE SHORT WAVE IMPULSE APPEARS TO BE DEVELOPING EAST ACROSS ERN MT AND WRN DAKOTAS ATTM...IT REMAINS TO BE SEEN WHETHER BACKGROUND ASCENT ASSOCIATED THIS FEATURE CAN OVERCOME MODEST AND PERSISTENT WARM SECTOR INHIBITION. RECENT CU TRENDS ACROSS THE BLACK HILLS SUGGEST AT LEAST ISOLATED HIGH TERRAIN DEVELOPMENT SHOULD OCCUR OVER THE NEXT FEW HOURS AND...GIVEN INTENSE SURFACE HEATING AND MIXING ACROSS THE BADLANDS...SOME OF THIS ACTIVITY MAY SURVIVE AND SPREAD EAST WITH ATTENDANT WIND AND LARGE HAIL HAZARDS THROUGH EARLY EVENING. SEVERE STORM DEVELOPMENT APPEARS A BIT MORE CERTAIN NEAR AND NORTH OF THE WARM FRONT...FROM NERN SD INTO SRN ND INTO THIS EVENING. AS LOW LEVEL INHIBITION IS WEAKENED THROUGH PERSISTENT BOUNDARY LAYER HEATING...AND MID LEVEL WARMING IS POTENTIALLY OFFSET BY WEAK LARGE SCALE ASCENT...EXPECT CHANCES FOR CONVECTIVE INITIATION TO INCREASE. STORMS DEVELOPING NORTH OF THE SURFACE WARM FRONT SHOULD REMAIN ELEVATED. HOWEVER...PROXIMITY OF STRONG INSTABILITY AND MORE THAN ADEQUATE EFFECTIVE BULK SHEAR WILL LEAD TO ROBUST UPDRAFTS AND PERHAPS A COUPLE OF SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. IF CELLS CAN DEVELOP OR TRACK NEAR THE WARM FRONT AND TAP NEAR SURFACE PARCELS...ISOLATED TORNADO AND DOWNBURST WIND THREATS COULD ENSUE. MAJORITY OF GUIDANCE INDICATES THAT AN MCS SHOULD EVOLVE FROM EVENING CONVECTION AND THIS SYSTEM WILL SPREAD EWD/ESEWD INTO MN THROUGH THE NIGHT SUSTAINED IN PART BY STRONG MASS INFLOW ON THE NOSE OF PLAINS LLJ. SEVERE WIND AND HAIL MAY ACCOMPANY THIS CONVECTION WELL INTO THE NIGHT ACROSS WRN/CNTRL AND SRN MN. ...SOUTH/SOUTHEAST... WIDESPREAD PULSE AND MULTICELL CONVECTION WAS UNDERWAY ALONG RESIDUAL FRONTAL AND OUTFLOW BOUNDARIES...AND SEA AND GULF BREEZES...FROM ERN NC SWWD TO LA/TX. ISOLATED WET DOWNBURST WINDS MAY DEVELOP WITH THIS CONVECTION AS IT MOVES INTO POCKETS OF STRONG LATE AFTERNOON INSTABILITY. ...SOUTHWEST... WEAK MID LEVEL DISTURBANCE ROTATING AROUND WRN/SWRN EDGE OF SUBTROPICAL HIGH WAS AIDING HIGH-TERRAIN TSTM DEVELOPMENT FROM SRN CA TO NRN PARTS OF AZ. MUCH OF SRN AZ REMAINS SHROUDED BY DEEP LAYER CLOUD COVER THAT WAS INHIBITING DESTABILIZATION ACROSS THESE AREAS. EXPECT CHANCES FOR DOWNBURST WINDS TO INCREASE IN THE NEXT FEW HOURS OVER AREAS THAT HAVE UNDERGONE STRONG HEATING... PRIMARILY FROM THE HIGHER ELEVATIONS OF SRN CA AND SRN NV...ACROSS PARTS OF CNTRL AND NRN AZ. ...SRN LWR MI...ERN GREAT LAKES...NORTHEAST... COLD FRONT WAS MOVING INTO WARM AND WEAKLY UNSTABLE AIR MASS FROM LOWER MI EWD ACROSS NRN NEW ENGLAND THIS AFTERNOON. A STORM OR TWO ALONG THE ADVANCING BOUNDARY COULD BRIEFLY ATTAIN SEVERE LEVELS WITH THE POTENTIAL FOR LOCALLY STRONG WIND GUSTS OR MARGINALLY SEVERE HAIL. ..CARBIN.. 08/22/2006  From swody1 at goshenarc.org Wed Aug 23 05:49:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 01:49:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230547 SWODY1 SPC AC 230546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT WED AUG 23 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VLY... ...SYNOPSIS... THE NRN STREAM WILL REMAIN ACTIVE ON WEDNESDAY. SEVERAL SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW WILL MOVE ACROSS THE NRN/HIGH PLAINS AND BE THE IMPETUS FOR EPISODIC TSTM CLUSTERS. LEAD SYSTEM OVER THE DAKS WILL TRANSLATE SEWD INTO THE LWR GRTLKS REGION BY WED EVE. AN UPSTREAM STRONGER TROUGH IS EXPECTED TO MOVE INLAND ACROSS THE PAC NW EARLY WED...THEN MOVE INTO THE NRN INTERMOUNTAIN WEST WED NIGHT. AHEAD OF THIS SYSTEM...A WEAKER IMPULSE SHOULD MOVE ACROSS THE NRN DAKS AND THE CANADIAN PRAIRIES WED AFTN. IN THE LWR-LVLS...TAIL END OF A FRONT WILL BE IN PLACE FROM THE MIDWEST NWWD INTO THE UPPER MS VLY WHILE A LEE TROUGH EXISTS FROM THE CNTRL DAKS SWD INTO THE CNTRL HIGH PLAINS THROUGH THE PERIOD. A NEW FRONT WILL GAIN STRENGTH ACROSS THE NRN INTERMOUNTAIN WEST AND NRN ROCKIES BY EARLY THU. ...UPPER MS VLY... SWLY LLJ AXIS IMPINGING ON THE NW-SE ORIENTED FRONT WILL BE FEEDING A WED MORNING MCS ACROSS PORTIONS OF THE UPPER MS VLY. ASSOCD OUTFLOW WILL REINFORCE THE BAROCLINIC ZONE THROUGH WED AFTN ACROSS NRN IL NWWD INTO SWRN MN. THE SHORTWAVE TROUGH/MCV WILL QUICKLY MOVE SEWD AND LIKELY OUTRUN THE SUPPLY OF STEEP LAPSE RATES. AS A RESULT...THE MCS WILL LIKELY DIMINISH/WEAKEN AS IT MOVES SEWD TOWARD THE MIDWEST/CNTRL GRTLKS REGION. OUTFLOW BOUNDARY/FRONT WILL GRADUALLY RECOVER AND MOVE NEWD WED AFTN. AIR MASS SW OF THE FRONT WILL BECOME QUITE UNSTABLE AS STEEP MID-LEVEL LAPSE RATES STREAM EWD FROM THE PLAINS AND SFC DEW POINTS REMAIN IN THE UPPER 60S. THERE IS A HIGH DEGREE OF UNCERTAINTY ON WHETHER SFC-BASED TSTMS WILL DEVELOP ALONG THE FRONT GIVEN LACK OF APPARENT LARGE SCALE ASCENT. BUT...REGION WILL REMAIN ALONG NE EDGE OF THE STRONGER CAP. LOCAL CONVERGENCE ALONG THE FRONT AND STRONG HEATING MAY CONTRIBUTE TO INITIATION FROM CNTRL/SRN MN INTO SWRN WI AND NRN IL BY MID-AFTN. GIVEN A STORM...THE 40-50 KT OF VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL...DAMAGING WINDS AND PERHAPS AN ISOLD TORNADO. LOW CONFIDENCE IN INITIATION ARGUES FOR LOW-END SLGT RISK/LOW SVR PROBABILITIES ATTM. ...NRN DAKS INTO NRN MN... ISOLD TSTMS MAY BACKBUILD/DEVELOP ACROSS SRN MANITOBA/SASK SWD INTO THE NRN DAKS ALONG A LEE TROUGH WED AFTN. CINH WILL BE AN ISSUE...PARTICULARITY ACROSS SD...BUT WEAK HEIGHT FALLS ASSOCD WITH A WEAK IMPULSE AND STRONG HEATING ALONG THE EDGE OF THE ELEVATED MIXED LAYER WILL WEAKEN THE CAP. MOST ACTIVITY SHOULD REMAIN N OF THE INTERNATIONAL BORDER...BUT GIVEN A STORM...SUPERCELLS WILL BE POSSIBLE WITH PRIMARILY LARGE HAIL. AFTER DARK...ELEVATED BANDS OF STORMS MAY EVOLVE/DEVELOP FARTHER NE INTO NRN MN WITH PERHAPS ISOLD LARGE HAIL. LOW PROBABILITIES WILL BE MAINTAINED AS COVERAGE IS EXPECTED TO BE ISOLD. ...NRN HIGH PLAINS/ROCKIES... STRONGER ASCENT WILL SPREAD NEWD ACROSS MT/WRN ND WED NIGHT AS UPPER TROUGH AND HEIGHT FALLS DEVELOP ACROSS THE REGION. LINEAR CONVECTIVE DEVELOPMENT MAY OCCUR ALONG THE LEADING EDGE OF THIS ASCENT. ISOLD DAMAGING WINDS MAY OCCUR WITH THE STRONGER STORMS...BUT MOISTURE WILL BE QUITE LIMITED IN THE BOUNDARY LAYER. ..RACY/GUYER.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 13:04:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 09:04:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231302 SWODY1 SPC AC 231301 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0801 AM CDT WED AUG 23 2006 VALID 231300Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST AND NRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN ND... ...UPPER MIDWEST/NRN PLAINS... A SHORTWAVE TROUGH OVER IL THIS MORNING WILL MOVE SEWD INTO THE OH VALLEY WITH A SHORTWAVE RIDGE MOVING INTO THE UPPER MIDWEST TODAY. AT THE SFC...ANALYSIS SHOWS A NEARLY STATIONARY FRONT EXTENDING ESEWD FROM SRN MN INTO THE CHICAGO IL AREA WITH SFC DEWPOINTS ALONG THE BOUNDARY IN THE LOWER TO MID 60S F. THIS SHOULD ALLOW MODERATE TO STRONG INSTABILITY TO DEVELOP ALONG AND TO THE SOUTHWEST OF THE BOUNDARY. HOWEVER...WARM AIR ALOFT AND A STRONG CAPPING INVERSION OVER THE WARM SECTOR WILL LIKELY KEEP CONVECTIVE DEVELOPMENT MINIMAL FROM FAR WRN MN EXTENDING SWD ACROSS ERN SD...WRN IA AND ERN NEB. THE CAPPING INVERSION SHOULD BE WEAKER JUST NORTH AND EAST OF THE STATIONARY FRONT ESPECIALLY BY EVENING. THE MOST LIKELY SPOT FOR INITIATION APPEARS TO BE ACROSS SRN MN AND/OR SCNTRL WI EARLY THIS EVENING WHERE MODEL FORECASTS SHOW ENHANCED LOW-LEVEL CONVERGENCE. IF MCS DEVELOPMENT OCCURS...THE MOST LIKELY TRACK WOULD BE SEWD INTO NRN IL AND POSSIBLY INTO FAR SW LOWER MI LATER TONIGHT. THE THUNDERSTORM ACTIVITY SHOULD REMAIN MOSTLY ELEVATED. HOWEVER...FORECAST SOUNDINGS ALONG THIS ZONE SHOW STRONG DEEP LAYER SHEAR WITH 0-6 KM SHEAR VALUES REACHING 50-60 KT. IN ADDITION...MID-LEVEL LAPSE RATES ARE FORECAST TO EXCEED 7.5 C/KM WHICH COMBINED WITH STRONG FLOW FROM THE LOW-LEVEL JET MAY BE FAVORABLE FOR SUPERCELLS AND/OR BOW ECHOES WITH HAIL AND ISOLATED WIND DAMAGE POSSIBLE. FURTHER NORTHWEST ACROSS NRN ND...THE UPPER-LEVEL RIDGE WILL LIKELY PREVENT CONVECTIVE DEVELOPMENT THIS AFTERNOON. HOWEVER...THUNDERSTORMS SHOULD DEVELOP EARLY THIS EVENING NEAR A SFC LOW FORECAST TO BE LOCATED IN FAR SRN SASKATCHEWAN. FORECAST SOUNDINGS IN THIS AREA SHOW ADEQUATE DIRECTIONAL SHEAR AND STRONG SPEED SHEAR IN THE LOWER TO MID-LEVELS. THIS COMBINED WITH VERY STEEP LASE RATES SHOULD RESULT IN A HIGH POTENTIAL FOR ROTATING STORMS WITH HAIL POTENTIAL. IF SUPERCELLS MOVE SEWD INTO NRN ND EARLY THIS EVENING...LARGE HAIL WILL BE VERY LIKELY. ...SRN PLAINS... LATEST ANALYSIS SHOWS A DIFFUSE STATIONARY FRONT LOCATED FROM FAR NE OK EXTENDING ESEWD ACROSS NE TX AND NRN LA. DEWPOINTS ALONG AND SOUTH OF THE BOUNDARY ARE IN THE LOWER TO MID 70S F WHICH SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY BY AFTERNOON. AS THUNDERSTORMS DEVELOP NEAR THE BOUNDARY THIS AFTERNOON...STEEP LOW-LEVEL LAPSE RATES ESPECIALLY IN NE TX WILL MAKE STRONG WIND GUSTS LIKELY WITH THE STRONGER MULTICELL STORMS. ...GA/SC/FL.. SCATTERED THUNDERSTORMS WILL DEVELOP TODAY ALONG AND SOUTH OF A NEARLY STATIONARY FRONT LOCATED ACROSS CNTRL AL...CNTRL GA AND SC. DEWPOINTS IN THE LOWER 70S F SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY. THIS COMBINED WITH STEEPENING LOW-LEVEL LAPSE RATES BY MID-AFTERNOON SHOULD BE ENOUGH FOR STRONG WIND GUSTS WITH SOME CELLS NEAR PEAK HEATING. ...AZ... LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWWD ACROSS SCNTRL AZ WHERE DEWPOINTS ARE IN THE LOWER TO MID 60S F. THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP WITH SCATTERED THUNDERSTORM INITIATION LIKELY OCCURRING ALONG THE MOGOLLON RIM BY LATE AFTERNOON. ALTHOUGH FORECAST SOUNDINGS SHOW RELATIVELY WEAK SHEAR PROFILES...0-3 KM LAPSE RATES SHOULD EXCEED 9.0 C/KM IN SOME AREAS MAKING STRONG WIND GUSTS LIKELY WITH THE SOME CELLS EARLY THIS EVENING. ..BROYLES/GUYER.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 16:35:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 12:35:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231634 SWODY1 SPC AC 231633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT WED AUG 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... ...NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... FAVORABLE LOW LEVEL WAA REGIME WILL REMAIN IN PLACE TODAY ATOP SURFACE OUTFLOW BOUNDARY/WARM FRONT WHICH EXTENDS FROM NERN IL/SERN WI NWWD TO SURFACE LOW ALONG THE ND-SD BORDER THIS MORNING. THIS BOUNDARY WILL MOVE LITTLE THROUGH THE AFTERNOON...WHILE STRONG HEATING AT THE SURFACE AND WARMING THROUGH H7 OCCURS ACROSS THE WARM SECTOR. APPEARS WSWLY H85 FLOW FROM 30-40 KT WILL PERSIST FOR MUCH OF THE DAY INTO THE NRN MS RIVER VALLEY AND CONTINUE DEVELOPING ELEVATED THUNDERSTORMS ALONG NERN EDGE OF MID LEVEL CAPPING ACROSS WRN/CENTRAL WI. MID LEVEL LAPSE RATES ARE QUITE STEEP AND FEED OF MODERATE INSTABILITY WILL SUPPORT STRONG UPDRAFTS...FURTHER ENHANCED BY 40-50 KT EFFECTIVE SHEAR...SUGGESTING ISOLATED LARGE HAIL MAY OCCUR WITH THIS ACTIVITY. SEVERE THREAT MAY INCREASE LATER THIS AFTERNOON AS STRONG SURFACE HEATING ALONG EDGE OF H7 THERMAL RIDGE OCCURS NEAR THE SURFACE FRONT OVER THE NRN MS RIVER VALLEY. FORECAST SOUNDINGS INDICATE CAP MAY WEAKEN SUFFICIENTLY FOR SURFACE-BASED DEVELOPMENT WITHIN AN ENVIRONMENT CHARACTERIZED BY 1500+ J/KG MLCAPE AND 40-50 KT DEEP LAYER SHEAR. THEREFORE...SUPERCELLS AND POSSIBLY ISOLATED TORNADOES/VERY LARGE HAIL WOULD BE FAVORED SHOULD SURFACE-BASED DEVELOPMENT OCCUR. OTHERWISE...EXPECT EVOLUTION INTO ANOTHER STRONG/SEVERE MCS WHICH WILL SPREAD ESEWD ACROSS THE CENTRAL GREAT LAKES AHEAD OF SHORTWAVE TROUGH NOW SHIFTING EWD ACROSS NERN MT/SRN SASK. HAVE ADJUSTED SLGT RISK AREA INTO PORTIONS OF SWRN MI TO ACCOUNT FOR THIS SCENARIO WHERE FORECAST SOUNDINGS LATER TONIGHT YIELD MUCAPE AROUND 1500 J/KG AND SUFFICIENT CLOUD-LAYER SHEAR FOR ROTATING UPDRAFTS. AS WAS THE CASE LAST NIGHT...MCS COULD BOW INTO A LINE THOUGH WIND DAMAGE POTENTIAL WILL DEPEND ON HOW STABLE THE BOUNDARY LAYER REMAINS. ATTM...EXPECT PRIMARY THREAT WILL BE FROM LARGE HAIL. ..EVANS/TAYLOR.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 17:34:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 13:34:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231732 SWODY1 SPC AC 231633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT WED AUG 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... ...NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... FAVORABLE LOW LEVEL WAA REGIME WILL REMAIN IN PLACE TODAY ATOP SURFACE OUTFLOW BOUNDARY/WARM FRONT WHICH EXTENDS FROM NERN IL/SERN WI NWWD TO SURFACE LOW ALONG THE ND-SD BORDER THIS MORNING. THIS BOUNDARY WILL MOVE LITTLE THROUGH THE AFTERNOON...WHILE STRONG HEATING AT THE SURFACE AND WARMING THROUGH H7 OCCURS ACROSS THE WARM SECTOR. APPEARS WSWLY H85 FLOW FROM 30-40 KT WILL PERSIST FOR MUCH OF THE DAY INTO THE NRN MS RIVER VALLEY AND CONTINUE DEVELOPING ELEVATED THUNDERSTORMS ALONG NERN EDGE OF MID LEVEL CAPPING ACROSS WRN/CENTRAL WI. MID LEVEL LAPSE RATES ARE QUITE STEEP AND FEED OF MODERATE INSTABILITY WILL SUPPORT STRONG UPDRAFTS...FURTHER ENHANCED BY 40-50 KT EFFECTIVE SHEAR...SUGGESTING ISOLATED LARGE HAIL MAY OCCUR WITH THIS ACTIVITY. SEVERE THREAT MAY INCREASE LATER THIS AFTERNOON AS STRONG SURFACE HEATING ALONG EDGE OF H7 THERMAL RIDGE OCCURS NEAR THE SURFACE FRONT OVER THE NRN MS RIVER VALLEY. FORECAST SOUNDINGS INDICATE CAP MAY WEAKEN SUFFICIENTLY FOR SURFACE-BASED DEVELOPMENT WITHIN AN ENVIRONMENT CHARACTERIZED BY 1500+ J/KG MLCAPE AND 40-50 KT DEEP LAYER SHEAR. THEREFORE...SUPERCELLS AND POSSIBLY ISOLATED TORNADOES/VERY LARGE HAIL WOULD BE FAVORED SHOULD SURFACE-BASED DEVELOPMENT OCCUR. OTHERWISE...EXPECT EVOLUTION INTO ANOTHER STRONG/SEVERE MCS WHICH WILL SPREAD ESEWD ACROSS THE CENTRAL GREAT LAKES AHEAD OF SHORTWAVE TROUGH NOW SHIFTING EWD ACROSS NERN MT/SRN SASK. HAVE ADJUSTED SLGT RISK AREA INTO PORTIONS OF SWRN MI TO ACCOUNT FOR THIS SCENARIO WHERE FORECAST SOUNDINGS LATER TONIGHT YIELD MUCAPE AROUND 1500 J/KG AND SUFFICIENT CLOUD-LAYER SHEAR FOR ROTATING UPDRAFTS. AS WAS THE CASE LAST NIGHT...MCS COULD BOW INTO A LINE THOUGH WIND DAMAGE POTENTIAL WILL DEPEND ON HOW STABLE THE BOUNDARY LAYER REMAINS. ATTM...EXPECT PRIMARY THREAT WILL BE FROM LARGE HAIL. ..EVANS/TAYLOR.. 08/23/2006  From swody1 at goshenarc.org Thu Aug 24 01:11:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 21:11:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240110 SWODY1 SPC AC 240109 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0809 PM CDT WED AUG 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER MS VALLEY AND UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF WRN ND... ...UPPER MS VALLEY THROUGH UPPER GREAT LAKES AREA... EARLY THIS EVENING A QUASISTATIONARY FRONT EXTENDS FROM A WEAK LOW IN CNTRL SD ESEWD THROUGH SRN MN...SRN WI...NRN IND AND EWD THROUGH THE OH VALLEY. THE ATMOSPHERE S OF FRONT REMAINS VERY UNSTABLE WITH STEEP LAPSE RATES AND MLCAPE FROM 4000 J/KG ACROSS SRN MN TO AROUND 1500 J/KG ACROSS NRN IND. STORMS CONTINUE NEAR AND JUST N OF THE BOUNDARY FROM S CNTRL WI SEWD INTO NRN IND. CURRENT THINKING IS THAT STORMS WILL CONTINUE DEVELOPING OVER CNTRL AND S CNTRL WI NEXT FEW HOURS AND SPREAD SEWD AS WLY LOW LEVEL JET ENHANCES ISENTROPIC LIFT AND THETA-E ADVECTION ON COOL SIDE OF FRONT. STORMS THAT DEVELOP AND TRACK SEWD NEAR THE FRONT WILL BE CLOSE ENOUGH TO SURFACE BASED FOR A CONTINUING ISOLATED TORNADO THREAT NEXT FEW HOURS WITH ANY DISCRETE SUPERCELL STRUCTURES. HOWEVER...SOME STORMS MAY ALSO EVOLVE INTO SMALL CLUSTERS AND BOWS AS THEY SPREAD SEWD. GIVEN THE STEEP LAPSE RATES...STRONG INSTABILITY AND FAVORABLE VERTICAL SHEAR FOR SUPERCELLS...SOME STORMS MAY BE CAPABLE OF PRODUCING VERY LARGE HAIL. FARTHER W ACROSS SRN MN WHERE THE STRONGER INSTABILITY EXISTS...THE 00Z RAOB FROM MINNEAPOLIS AS WELL AS LACK OF BOUNDARY LAYER CUMULUS CONFIRM THAT THE ATMOSPHERE IS STILL CAPPED IN THIS AREA. LIFT MAY INCREASE ALONG MN PORTION OF THE BOUNDARY LAYER THIS EVENING AS THE LOW LEVEL JET STRENGTHENS. HOWEVER...GIVEN THE CAP IN PLACE...CONFIDENCE IS NOT HIGH THAT STORMS WILL BE ABLE TO DEVELOP MUCH FARTHER W THAT CURRENT ONGOING ACTIVITY. ...ND... ISOLATED HIGH BASED STORMS HAVE DEVELOP IN THE DEEPLY MIXED REGIME ACROSS WRN ND. LOW LEVEL THERMODYNAMIC PROFILES WITH LARGE TEMPERATURE/DEWPOINT SPREADS AND STEEP LAPSE RATES WILL SUPPORT A THREAT OF ISOLATED DAMAGING WIND. SOME HAIL MAY ALSO ACCOMPANY THE STRONGER STORMS. FORCING FOR ASCENT WILL INCREASE ACROSS WRN ND TOWARD THE END OF THIS PERIOD AS A STRONG SHORTWAVE TROUGH APPROACHES FROM THE W. THREAT FOR ELEVATED STORMS CAPABLE OF PRODUCING HAIL WILL BE THE MAIN THREAT. ..DIAL.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 06:01:15 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 02:01:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240601 SWODY1 SPC AC 240600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT THU AUG 24 2006 VALID 241200Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF ERN SD THROUGH CNTRL AND SRN MN AND EXTREME NRN IA... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE NRN AND CNTRL PLAINS THROUGH THE UPPER MS VALLEY AREA... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE OH VALLEY THROUGH MID ATLANTIC AND NERN U.S.... ...SYNOPSIS... STRONG SHORTWAVE TROUGH OVER THE NRN ROCKY MOUNTAIN REGION WILL MOVE EWD INTO THE NRN PLAINS AND UPPER MS VALLEY THIS PERIOD...RESULTING IN LEE CYCLOGENESIS AND DEAMPLIFICATION OF SHORTWAVE RIDGE. A MORE SUBTLE LEAD VORT MAX CURRENTLY OVER SRN MT WILL MOVE EWD IN ADVANCE OF THE MAIN UPPER TROUGH. A COLD FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH INTO THE NRN PLAINS. BY EARLY THURSDAY THE FRONT WILL EXTEND FROM ERN MT SWWD THROUGH ERN WY. THIS BOUNDARY ALONG WITH DEVELOPING LEE CYCLONE WILL ADVANCE EWD THROUGH THE DAKOTAS DURING THE DAY. A QUASISTATIONARY FRONT WILL EXTEND FROM THE LOW OVER SD EWD THROUGH SRN MN AND SRN WI. ...NRN PLAINS THROUGH UPPER MS VALLEY AREA... RESERVOIR OF UNTAPPED INSTABILITY WILL PERSIST OVER PORTIONS OF SD INTO SRN MN GENERALLY NEAR AND S OF E-W FRONT. BOUNDARY LAYER IN WARM SECTOR WILL MOST LIKELY REMAIN CAPPED BY A STRONG EML MUCH OF THE DAY. STORMS MAY BE ONGOING EARLY THURSDAY N OF FRONT MOSTLY ACROSS ND AS FORCING FOR ASCENT ACCOMPANYING LEAD SHORTWAVE TROUGH INCREASES. DOWNSTREAM FROM THIS ACTIVITY AND ESPECIALLY S OF E-W FRONT FROM CNTRL AND ERN SD INTO SRN MN...THE ATMOSPHERE SHOULD BECOME VERY UNSTABLE AS SURFACE HEATING COMMENCES. STORMS MAY INITIALLY INTENSIFY ALONG EWD ADVANCING COLD FRONT. STRONG LINEAR FORCING ENHANCED BY DEEP LAYER ASCENT ACCOMPANYING EWD ADVANCING SHORTWAVE TROUGH MAY RESULT IN ACTIVITY EVOLVING INTO A LINEAR MCS. HOWEVER...SOME SUPERCELL STRUCTURES WILL BE POSSIBLE ESPECIALLY ALONG SRN END OF THE LINE. DAMAGING WIND AND LARGE HAIL WILL BE THE MAIN THREATS...BUT AN ISOLATED TORNADO OR TWO WILL ALSO BE POSSIBLE WITH ANY SUPERCELL MODES WITHIN THE LINE. FARTHER EAST...ASCENT ASSOCIATED WITH LEAD SHORTWAVE TROUGH AND A BRANCH OF THE LOW LEVEL JET E OF SURFACE LOW WILL MAINTAIN FORCING FOR ASCENT ALONG AND N OF THE E-W STATIONARY FRONT. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP NEAR AND JUST N OF THE BOUNDARY AS THE CAP WEAKENS DURING THE AFTERNOON. ESELY LOW LEVEL FLOW NEAR FRONT VEERING TO WSWLY AND INCREASING TO 40+ KT AT 6 KM WILL CONTRIBUTE TO FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR PROFILES FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES. VERY LARGE HAIL AND A FEW TORNADOES WILL BE POSSIBLE WITH ANY DISCRETE SUPERCELLS THAT DEVELOP NEAR THIS BOUNDARY. OVERNIGHT...STORMS MAY EVOLVE INTO ONE OR MORE MCSS AS THE LOW LEVEL JET INCREASES WITH A CONTINUING THREAT FOR MAINLY DAMAGING WIND AND LARGE HAIL FROM THE UPPER MS VALLEY INTO PARTS OF THE GREAT LAKES. ...OH VALLEY THROUGH MID ATLANTIC AND NERN STATES... STORMS MAY STILL BE IN PROGRESS IN WARM ADVECTION REGIME FROM PARTS OF SRN LOWER MI INTO NRN OH EARLY THURSDAY. POTENTIAL WILL EXIST FOR SOME OF THIS ACTIVITY TO BECOME SURFACE BASED AS THE DOWNSTREAM ATMOSPHERE DESTABILIZES. PRIMARY THREAT WILL BE DAMAGING WIND AS ACTIVITY ADVANCES ESEWD. OTHER STORMS MAY DEVELOP DOWNSTREAM OVER PARTS OF THE MID ATLANTIC AS THE ATMOSPHERE DESTABILIZES AND AS VORT MAX ROTATES SEWD THROUGH BASE OF UPPER TROUGH. BOUNDARY LAYER FLOW WILL BE RATHER WEAK...BUT DEEP LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR UPDRAFT ROTATION. POOR MID LEVEL LAPSE RATES AND MODEST INSTABILITY WILL LIMIT OVERALL HAIL POTENTIAL. HOWEVER...THE STRONGER STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS. ..DIAL/GUYER.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 16:34:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 12:34:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241635 SWODY1 SPC AC 241633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT THU AUG 24 2006 VALID 241630Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF ERN SD...SRN MN AND EXTREME WRN WI... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK ACROSS THE NRN AND CENTRAL PLAINS AND THE UPPER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS IN DELMARVA... ...SYNOPSIS... POTENT SHORTWAVE TROUGH MOVING INTO WRN ND WILL SHIFT EWD INTO NRN MN TONIGHT. SURFACE LOW OVER WRN SD AND ASSOCIATED N-S COLD FRONT IS FORECAST TO MOVE EWD INTO THE ERN DAKOTAS/CENTRAL NEB BY EARLY EVENING..AND THEN INTO MN/WRN IA TONIGHT. SURFACE LOW MOVING SHOULD MAINTAIN CURRENT POSITION OF WARM FRONT THROUGH THE AFTERNOON FROM EAST CENTRAL SD ESEWD ACROSS FAR SRN MN TO NEAR THE IL/WI BORDER. CONVERGENCE ALONG WARM FRONT SHOULD BE ENHANCED BY STRONG HEATING SOUTH AND CLOUDS/COOLER TEMPERATURES NORTH OF THE BOUNDARY. OTHER THUNDERSTORMS ARE ALSO POSSIBLE ALONG EWD EXTENSION OF FRONT FROM THE UPPER MIDWEST INTO THE MID ATLANTIC STATES. ...NRN PLNS INTO UPR MS VLY... WIDESPREAD DAMAGING WIND EVENT AND POSSIBLY STRONG TORNADOES ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT...ESPECIALLY ACROSS THE MODERATE RISK AREA. LARGE AREA OF CLOUDS ACROSS MOST OF THE DAKOTAS WILL REDUCE THE AMOUNT OF HEATING ACROSS THIS AREA THIS AFTERNOON. HOWEVER...STRONG FORCING HAS ALREADY RESULTED IN ELEVATED SEVERE THUNDERSTORMS ACROSS WRN ND IN ASSOCIATION WITH LARGE SCALE FORCING. DESPITE STABLE BOUNDARY...EFFECTIVE SHEAR NEAR 50 KT AND MUCAPES IN EXCESS OF 3000 J/KG...AS OBSERVED ON BIS MORNING SOUNDING...WILL BE FAVORABLE FOR SUPERCELLS TO MOVE/DEVELOP SEWD ALONG INSTABILITY AXIS TOWARD SERN ND/NRN SD. DESPITE RELATIVELY STABLE BOUNDARY LAYER...THE DEGREE OF SHEAR/INSTABILITY WILL BE FAVORABLE FOR SEVERE HAIL/WINDS. OTHER ELEVATED STORMS ARE ALSO LOCATED ACROSS SERN MN/WRN WI IN ASSOCIATION WITH WARM ADVECTION NORTH OF WARM FRONT. DEEP LAYER SHEAR AND STRONG INSTABILITY ALSO FAVOR SEVERE HAIL/WINDS WITH THESE STORMS AS THEY GRADUALLY MOVE/DEVELOP SEWD. SURFACE BASED STORMS ARE MOST LIKELY TO DEVELOP NEAR THE WARM FRONT ACROSS ERN SD/SWRN MN WHERE STRONG HEATING SHOULD RESULT IN AN EXTREMELY UNSTABLE AIR MASS WITH MLCAPES IN EXCESS OF 4000 J/KG. WARM 700 MB TEMPERATURES BETWEEN 14-16C SHOULD KEEP THIS AREA CAPPED MOST OF THE DAY...THOUGH THIS LAYER WILL COOL AS LARGE SCALE FORCING SPREADS INTO THE REGION. THE POTENTIAL EXISTS FOR STORMS TO FIRST DEVELOP N OF THE BOUNDARY AS THE CAP SHOULD ERODE MORE RAPIDLY NORTH OF THE BOUNDARY. THOUGH THESE STORMS WOULD BE SLIGHTLY ELEVATED...THE STORMS MAY QUICKLY EVOLVE INTO A LINE/BOW AND THEN MOVE ESEWD. WIDESPREAD WIND DAMAGE WOULD BE POSSIBLE GIVEN THE DEGREE OF INSTABILITY AND DEEP LAYER SHEAR. EVENTUALLY...SURFACE BASED STORMS ARE EXPECTED TO DEVELOP NEAR THE WARM FRONT LATE THIS AFTERNOON. THE EXTREME INSTABILITY AND 60 KT DEEP LAYER SHEAR WILL RESULT IN THE RAPID DEVELOPMENT OF SUPERCELLS. ANY DISCRETE SUPERCELLS THAT CAN BE MAINTAINED NEAR THE WARM FRONT WILL INGEST A MOIST BOUNDARY LAYER WITH 25-30 KT 1 KM SHEAR...WHICH WOULD BE SUPPORTIVE OF STRONG TORNADOES LATE THIS AFTERNOON/EVENING. AS THE LOW LEVEL JET STRENGTHENS THIS EVENING ...THE SUPERCELLS SHOULD EVOLVE INTO A LINE/BOW AND MOVE ESEWD ALONG WARM FRONT ACROSS SRN MN AND INTO WI...WITH THE MAIN THREAT BECOMING DAMAGING WIND GUSTS...WITH SOME POSSIBLY EXTREME. ...NEB... HIGH BASED THUNDERSTORMS ARE ALSO POSSIBLE ALONG SRN EXTENSION OF COLD FRONT FROM SERN SD SWWD ACROSS NEB LATE THIS AFTERNOON. DEEP LAYER SHEAR AROUND 30 KT AND DEWPOINT DEPRESSIONS NEAR 50F WOULD SUPPORT STRONG WIND GUSTS. ...DELMARVA... ABUNDANT SUNSHINE WAS PREVALENT ACROSS THE REGION AND SHOULD RESULT IN AT LEAST MODERATE INSTABILITY THIS AFTERNOON. GIVEN WEAK FRONTAL BOUNDARY AND WEAK IMPULSES MOVING EWD THROUGH THE AREA...A FEW STRONG STORMS WITH MARGINALLY SEVERE WIND GUSTS ARE POSSIBLE THIS AFTERNOON. ..IMY/TAYLOR.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 20:00:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 16:00:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 242000 SWODY1 SPC AC 241958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0258 PM CDT THU AUG 24 2006 VALID 242000Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PARTS OF NERN SD...SERN ND...CNTRL/SRN MN AND W-CNTRL WI... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE DAKOTAS INTO PARTS OF THE UPPER GREAT LAKES... ...DAKOTAS INTO THE UPPER GREAT LAKES... COMPLEX SCENARIO IS EVOLVING TODAY ACROSS THE REGION IN ADVANCE OF STRONG SHORT WAVE TROUGH TRANSLATING EWD THROUGH WRN/CNTRL ND. WATER VAPOR IMAGERY SUGGESTS THAT A LEAD IMPULSE IS CURRENTLY SHIFTING EWD THROUGH CNTRL/ERN SD WHICH IS LIKELY SUPPORTING THE ONGOING STORMS FROM FAR NERN SD INTO CNTRL MN. IN THE LOW-LEVELS...PRIMARY SURFACE LOW APPEARS TO BE W OF MBG WITH ATTENDANT WARM FRONT EXTENDING SEWD TO NEAR HON AND THEN ACROSS SRN MN TO NEAR THE WI/IL BORDER. A SECONDARY SURFACE LOW WAS ANALYZED ALONG THIS BOUNDARY N OR NE OF FSD WITH A TRAILING PRE-FRONTAL TROUGH STRETCHING SWWD FROM THIS LOW INTO CNTRL NEB. MEANWHILE...COLD FRONT /CURRENTLY MASKED BY ADIABATIC DOWNSLOPE WARMING/ EXTENDED FROM NEAR MOT TO PHP INTO THE NEB PNHDL. THUS FAR TODAY...PRIMARY SEVERE IN THE FORM OF ELEVATED SUPERCELLS PRODUCING LARGE /AND AT TIMES SIGNIFICANT/ HAIL HAS PERSISTED FROM CNTRL MN INTO SRN WI IN ASSOCIATION WITH LOW-LEVEL WAA/ISENTROPIC ASCENT REGIME N OF WARM FRONT. BOTH 12Z AND 18Z REGIONAL SOUNDINGS INDICATE THAT INFLOW PARCEL SOURCE REGION OVER THE MID MO VALLEY INTO SRN MN REMAINS MODERATE TO STRONGLY UNSTABLE WITH MUCAPES OF 2500-4500 J/KG. STRENGTHENING SWLY LLJ THIS AFTERNOON AND TONIGHT SHOULD MAINTAIN CLUSTERS OF ELEVATED SUPERCELLS TO THE N OF SURFACE BOUNDARY WITH VERY LARGE HAIL BEING THE MAIN SEVERE THREAT. OTHER SURFACE-BASED STORMS WILL BECOME INCREASINGLY LIKELY LATE THIS AFTERNOON INTO EVENING FROM SERN SD EWD ACROSS SRN MN NEAR AND E OF TRIPLE POINT ASSOCIATED WITH SECONDARY SURFACE LOW. MODERATELY STRONG LOW-LEVEL SHEAR /0-1 KM SRH OF 100-200 M2/S2/ COUPLED WITH THE MODERATE TO STRONG INSTABILITY AND 40-50 KTS OF EFFECTIVE BULK SHEAR INDICATE THE POTENTIAL FOR SUPERCELLS CAPABLE OF A FEW TORNADOES...LARGE HAIL AND DAMAGING WINDS SHOULD STORMS DEVELOP AND BECOME SUSTAINED. FARTHER DOWNSTREAM...TSTM COMPLEX OVER SRN WI WILL POSE A DAMAGING WIND/LARGE HAIL THREAT AS IT CONTINUES SEWD ALONG BAROCLINIC ZONE ACROSS SERN WI/NERN IL. MEANWHILE...A LARGE CLUSTER OF TSTMS INCLUDING EMBEDDED SUPERCELLS CONTINUES TO INCREASE IN COVERAGE AND INTENSITY THIS AFTERNOON OVER PORTIONS OF WRN AND CNTRL ND...IMMEDIATELY AHEAD OF SHORT WAVE TROUGH. VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT AIR MASS IS RECOVERING AHEAD OF THIS ACTIVITY OVER N-CNTRL SD INTO S-CNTRL ND WHERE STRONGER DIABATIC HEATING HAS ALLOWED TEMPERATURES TO WARM INTO THE 80S...SUPPORTING MLCAPES OF 1500-3000 J/KG. WHILE THERE HAS BEEN SOME TENDENCY FOR STORMS TO EVOLVE INTO A MORE LINEAR CONFIGURATION...POTENTIAL STILL EXISTS FOR MORE DISCRETE SUPERCELLS ALONG SRN PORTION OF COMPLEX NEAR SURFACE LOW AND ATTENDANT WARM FRONT WITH A THREAT OF A FEW TORNADOES AS WELL AS LARGE HAIL AND DAMAGING WINDS. THERE IS SOME UNCERTAINTY AS TO HOW FAR S STORMS WILL FORM INTO CNTRL SD OWING TO CLOSE PROXIMITY OF LEAD SHORT WAVE TROUGH OVER ERN SD. LATEST VISIBLE IMAGERY DOES INDICATE DEEPENING CUMULUS ALONG COLD FRONT SW OF MBG AND SSE PHP. SHOULD STORMS DEVELOP AND BECOME SUSTAINED THE COMBINATION OF MODERATE TO STRONG INSTABILITY AND MODERATELY STRONG VERTICAL SHEAR WILL BE SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES CAPABLE OF LARGE HAIL...DAMAGING WINDS AND PERHAPS A COUPLE OF TORNADOES. ..MEAD.. 08/24/2006  From swody1 at goshenarc.org Fri Aug 25 01:04:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 21:04:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250105 SWODY1 SPC AC 250103 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0803 PM CDT THU AUG 24 2006 VALID 250100Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM SOUTHEAST SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND PARTS OF SOUTHWEST WISCONSIN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM ERN SD TO LAKE MI SWD TO KS AND WRN MO... ...VOLATILE SEVERE WEATHER SITUATION CONTINUING ACROSS EASTERN SOUTH DAKOTAS...SOUTHERN MINNESOTA...AND WESTERN WISCONSIN THIS EVENING... COMPACT AND FAST MOVING MID LEVEL IMPULSE AND ASSOCIATED 50-60KT WLY SPEED MAX WILL CONTINUE TO DRIVE DANGEROUS SEVERE WEATHER EPISODE ACROSS PARTS OF THE NRN PLAINS/UPPER MS VALLEY INTO TONIGHT. A PLUME OF EXTREMELY UNSTABLE AIR /MLCAPE IN EXCESS OF 5000 J PER KG/ CONTINUES TO WRAP INTO THE WARM SECTOR OF ASSOCIATED VIGOROUS SURFACE CYCLONE MOVING EWD ALONG INTENSE WARM FRONT FROM ERN SD AND SRN MN. IN ADDITION TO VERY MOIST AND HIGHLY UNSTABLE AIR MASS...PRONOUNCED DIRECTIONAL SHEAR EXISTS NEAR OUTFLOW-REINFORCED WARM FRONT OVER SRN MN...WHERE LATEST DIAGNOSTIC DATA INDICATES 0-1KM SRH GREATER THAN 250 M2/S2. THESE CONDITIONS WILL CONTINUE TO FUEL INTENSE SUPERCELLS WITH TORNADOES...HIGH WINDS...AND VERY LARGE HAIL OVER PORTIONS OF SERN SD INTO SCNTRL MN THIS EVENING. ONGOING TORNADIC SUPERCELL WAS RECENTLY MOVING NEAR HURON SD AND APPEARS TO BE LOCATED IN CLOSE PROXIMITY TO SYNOPTIC SURFACE LOW. DAMAGING TORNADOES WERE ALSO RECENTLY REPORTED IN NICOLLET AND LE SEUR COUNTIES IN SCNTRL MN. TORNADIC SUPERCELLS OVER MN APPEAR TO HAVE FORMED ON THE INTENSE WARM FRONT SOUTH OF MSP. ADDITIONAL ELEVATED ACTIVITY WAS TRACKING NORTH OF THE WARM FRONT AND WILL CONTINUE TO PRODUCE HAIL AND LOCALLY STRONG WINDS FROM THE MSP AREA INTO WRN WI THIS EVENING. SD SUPERCELL MAY PERSIST WITHIN NARROW CORRIDOR BETWEEN RELATIVELY STRONG WARM SECTOR CAP ALONG/SOUTH OF THE SD/MN BORDERS...AND OUTFLOW AIR MASS NORTH OF THE WARM FRONT. HOWEVER...LATEST GUIDANCE APPEARS TO SUGGEST THAT CAP...TIME OF DAY...AND DEAMPLIFICATION OF UPPER WAVE...MAY BEGIN TO TEMPER SEVERE WEATHER POTENTIAL FROM SWRN MN INTO IA OVERNIGHT. DESPITE THESE INDICATIONS...LIFT ALONG THE COLD FRONT/WIND SHIFT WILL DEVELOP SEWD INTO THE INSTABILITY AXIS ACROSS THESE AREAS LATER TONIGHT. THIS WARRANTS MAINTAINING A SLGT RISK AND RELATIVELY LOW SEVERE PROBABILITIES OVER THE AREA AT THIS TIME. ...NEB/ERN KS/WRN MO... HOT AND MODERATELY UNSTABLE AIR MASS SHOULD PERSIST ACROSS THE CNTRL PLAINS AS FRONT/WIND SHIFT SPREADS SEWD OVERNIGHT. LATEST NAM-WRF AND NCEP-SREF WERE INDICATING A POTENTIAL FOR SCATTERED TSTM DEVELOPMENT AS THE FRONT MOVES SEWD. SHEAR ACROSS THE AREA APPEARS MARGINALLY SUPPORTIVE OF UPDRAFT PERSISTENCE AND IF A CLUSTER OR TWO OF STORMS CAN DEVELOP...MASS INFLOW ON THE PLAINS NOCTURNAL LOW LEVEL JET MAY BE ENOUGH TO SUSTAIN STORMS INTO EARLY FRIDAY FROM SERN KS INTO WRN MO. PROBABILITY OF HAIL AND HIGH WINDS WITH THIS POTENTIAL ACTIVITY APPEARS GREAT ENOUGH TO WARRANT A SLGT RISK ACROSS THE MO RIVER VALLEY FOR THE REST OF TONIGHT. ..CARBIN.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 05:57:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 01:57:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250557 SWODY1 SPC AC 250556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT FRI AUG 25 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE WRN GREAT LAKES/UPPER MIDWEST TO SRN PLAINS/HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE WRN GREAT LAKES FROM PA/NY TO NRN NJ... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL ROCKIES... ...SYNOPSIS... RELATIVELY HIGH-AMPLITUDE FLOW REGIME ACROSS SRN CANADA/NRN U.S. WILL MAINTAIN A BELT OF MODERATE CYCLONIC FLOW ACROSS THE UPPER MS VALLEY/WRN GREAT LAKES REGIONS THROUGH TODAY...WHILE SHARP DOWNSTREAM RIDGE BUILDS ACROSS ONTARIO AND WRN QUEBEC. WEAKER DOWNSTREAM IMPULSES...UNDERCUTTING THE RIDGE AXIS...WILL TRAVEL SEWD IN A BAND OF MODEST WNWLY MID LEVEL FLOW FROM THE ERN GREAT LAKES...ACROSS PA/NY...TO SRN NEW ENGLAND AND NJ. IN THE WEST...A POSITIVE-TILT UPPER TROUGH WILL DIG SEWD OVER THE NRN GREAT BASIN WITH HEIGHT FALLS AND DIFFLUENT MID/UPPER LEVEL FLOW SPREADING ACROSS THE NRN/CNTRL ROCKIES. SURFACE LOW ASSOCIATED WITH THE UPPER MS VALLEY/GREAT LAKES TROUGH WILL DEVELOP GENERALLY EWD ALONG A WARM FRONT FROM WI TO LOWER MI AS TRAILING COLD FRONT MAKES RELATIVELY SLOW PROGRESS EWD/SEWD ACROSS IA AND THE UPPER MIDWEST THROUGH SATURDAY MORNING. WRN EXTENSION OF THE FRONT WILL MOVE A BIT FASTER ACROSS THE SCNTRL PLAINS...AND PUSH WWD/SWWD INTO THE HIGHER TERRAIN FROM WY SWD ACROSS CO. A QUASI-STATIONARY WARM FRONTAL ZONE...ALIGNED WITH THE DEEP-LAYER WNWLY FLOW FROM THE LOWER/ERN GREAT LAKES TO SRN NEW ENGLAND/NJ WILL PROVIDE A NARROW CORRIDOR FOR ASCENT ACROSS THESE REGIONS THROUGH THE PERIOD. ...UPPER MIDWEST/GREAT LAKES... WARM AND VERY MOIST AIR MASS WILL CONTINUE TO BE INCORPORATED INTO ZONE OF PERSISTENT ASCENT AHEAD OF SURFACE LOW AND COLD FRONT THROUGH THE AFTERNOON. DAYTIME HEATING COUPLED WITH 65-75F DEWPOINTS WILL CONTRIBUTE TO MODERATE TO STRONG AFTERNOON DESTABILIZATION WITH MLCAPES OF 1500-3500 J/KG EXPECTED FROM CNTRL SRN WI/NRN IL SWWD ACROSS ERN IA. GIVEN WIDESPREAD CONVECTIVE DEBRIS BUT PERSISTING LIFT NORTH OF THE WARM FRONT...FROM CNTRL/NRN WI ACROSS MUCH OF MI...ELEVATED TSTMS CAPABLE OF MARGINALLY SEVERE HAIL MAY CONTINUE THROUGH THE DAY FRIDAY OVER THESE AREAS. MORE INTENSE...SURFACE-BASED STORM DEVELOPMENT APPEARS INCREASINGLY LIKELY BY AFTERNOON FROM VICINITY OF SURFACE LOW SWD ALONG COLD FRONT FROM CNTRL/SRN WI INTO NRN IL AS HEATING AND LARGE-SCALE FORCING FOR ASCENT EFFECTIVELY ERODE THE CAP. MODEST WLY FLOW ATOP THE DESTABILIZING AIR MASS WILL PROVIDE MORE THAN ADEQUATE VERTICAL SHEAR FOR SUPERCELL STORMS AND PERHAPS BOWING LINE SEGMENTS CAPABLE OF BOTH LARGE HAIL AND DAMAGING WINDS. TORNADO POTENTIAL APPEARS TO BE SLIGHTLY LOWER THAN THURSDAY WITH WEAKER/VEERED LOW LEVEL FLOW NEAR THE FRONT. HOWEVER...BETTER POTENTIAL FOR A TORNADO OR TWO MAY EVOLVE FROM STORMS DEVELOPING NEAR SURFACE LOW AND MOVING ALONG THE WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE ENHANCED. CELLS ENCOUNTERING POSSIBLE LAKE BREEZE BOUNDARY ACROSS ERN WI MAY ALSO POSE A THREAT FOR A BRIEF TORNADO OR TWO. FARTHER SW ALONG THE ADVANCING COLD FRONT...FROM ERN IA INTO ERN MO AND IL...DEEP LAYER SHEAR WILL DIMINISH. HOWEVER...STRONG DESTABILIZATION WILL DEVELOP BENEATH STOUT CAP. FRONTAL CIRCULATION MAY BE SUFFICIENT TO OVERCOME THE CAP WITH A FEW INTENSE STORMS POSSIBLE ACROSS THESE AREAS FROM LATE AFTERNOON INTO THE EVENING. ISOLATED HAIL AND STRONG/DAMAGING WINDS COULD ACCOMPANY THIS ACTIVITY. ...KS SWWD/WWD ACROSS THE PNHDLS INTO THE SRN HIGH PLAINS... STEEPENING LOW THROUGH MID-LEVEL LAPSE RATES AND MOIST BOUNDARY LAYER WILL COEXIST ALONG AND NORTH OF SURFACE FRONT/WIND SHIFT SETTLING SOUTH INTO THESE AREAS DURING THE AFTERNOON. MLCAPES OF 1500-2500 J/KG AND LOW LEVEL CONVERGENCE/MIXING ALONG THE FRONT WILL LEAD TO INCREASING TSTM COVERAGE AND INTENSITY. THIS WILL OCCUR COINCIDENT WITH A SLIGHT INCREASE IN SWLY MID LEVEL FLOW...AND ATOP LOW LEVEL ELY FLOW...THUS PROVIDING AN ENVIRONMENT WITH MARGINALLY SUPPORTIVE SHEAR FOR ORGANIZED AND PERSISTENT STORMS. LATEST GUIDANCE SUGGESTS THAT THIS CONVECTION WILL CONTINUE WELL INTO THE EVENING AND POSSIBLY EVOLVE INTO AN MCS ACROSS PARTS OF SRN KS/NRN OK. LOW LEVEL MASS INFLOW AND DEGREE OF INSTABILITY SHOULD SUSTAIN A SEVERE HAIL/WIND THREAT FROM THIS CONVECTION ACROSS THESE AREAS THROUGH EARLY SATURDAY. ...NCNTRL ROCKIES... HEIGHT FALLS...DIFFLUENT MID LEVEL FLOW...AND LOW LEVEL UPSLOPE FLOW WILL SPREAD ACROSS PARTS OF NRN UT/WRN WY AND CO DURING THE PERIOD OF PEAK HEATING. AS LARGE SCALE ASCENT IMPINGES ON SUBTROPICAL MOISTURE PLUME ACROSS THE AREA...STEEP LAPSE RATES AND MOISTENING WILL LEAD TO SUFFICIENT INSTABILITY FOR STRONG TO SEVERE STORMS. RELATIVELY HIGH-BASED SUPERCELLS WILL POSE A THREAT FOR HAIL AND HIGH WINDS. ...ERN GREAT LAKES ACROSS NY/PA TO NJ... NAM AND GFS INDICATE THAT SHORT WAVE IMPULSE UNDERCUTTING RIDGE AXIS ACROSS SRN ONTARIO WILL SPREAD EAST AND ENHANCE ASCENT ALONG THE STATIONARY FRONTAL ZONE FROM LAKE ERIE ACROSS NY/PA. VERTICAL SHEAR ALONG THE SURFACE FRONT WILL REMAIN QUITE FAVORABLE FOR SUPERCELLS THROUGH THE PERIOD GIVEN THE DEVELOPMENT AND MAINTENENCE OF CONVECTION. MODELS AGREE THAT MOST FAVORABLE JUXTAPOSITION OF DESTABILIZATION...FORCING...AND SHEAR MAY EVOLVE FROM WRN NY ACROSS NCNTRL PA THROUGH EARLY EVENING. SUPERCELL STORMS ACROSS THESE AREAS COULD BE CAPABLE OF PRODUCING HAIL AND POSSIBLY A TORNADO OR TWO. ..CARBIN/GUYER.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 12:50:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 08:50:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251250 SWODY1 SPC AC 251249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT FRI AUG 25 2006 VALID 251300Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT FROM KS NEWD TO WI...THEN ESEWD TO NRN PA... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR NE UT/NW CO/SW WY... ...ERN IA/NW IL/SRN WI THIS AFTERNOON... A MID LEVEL TROUGH OVER THE CANADIAN PRAIRIES WILL PROGRESS EWD TO ONTARIO...WHILE THE SRN EXTENT OF THIS TROUGH MOVES EWD FROM MN THIS MORNING TO UPPER MI/LAKE SUPERIOR THIS EVENING WHILE GRADUALLY WEAKENING. AN ASSOCIATED SURFACE CYCLONE ACROSS SRN MN/NRN IA WILL MOVE EWD ACROSS SRN WI TO LAKE MI AND WEAKEN IN CONJUNCTION WITH DE-AMPLIFICATION OF THE MID LEVEL WAVE. A TRAILING COLD FRONT SHOULD CONTINUE SLOWLY SEWD ACROSS IA/NRN MO/KS THROUGH TONIGHT. FARTHER E...THE SURFACE PATTERN HAS BEEN COMPLICATED BY OUTFLOW FROM OVERNIGHT STORMS ACROSS SRN WI/NERN IA. AN OUTFLOW BOUNDARY EXTENDS FROM E CENTRAL IA INTO SE WI AS OF 11Z...WHILE THE PRIMARY BAROCLINIC ZONE IS LOCATED FARTHER N FROM CENTRAL WI ACROSS SRN LOWER MI. OVERNIGHT CONVECTION HAS EXHAUSTED MUCH OF THE STRONGER INSTABILITY...AND THE RICHER BOUNDARY LAYER MOISTURE /MID 60S OR GREATER/ IS CONFINED TO A NARROW CORRIDOR FROM ERN KS/WRN MO INTO IA. SOME RECOVERY WILL BE POSSIBLE THROUGH THIS AFTERNOON IN ADVANCE OF THE SURFACE LOW/COLD FRONT AND IN THE WAKE OF THE MORNING CONVECTION...AND A FEW THUNDERSTORMS MAY FORM FROM ERN IA INTO SRN WI. VERTICAL SHEAR AND LOW-MID LEVEL FLOW FIELDS ARE EXPECTED TO WEAKEN SLOWLY THROUGH THIS EVENING IN THE WARM SECTOR...THOUGH VERTICAL SHEAR MAY REMAIN AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS ACROSS WI THIS AFTERNOON. ...LOWER MI TO PA AREA THROUGH THIS EVENING... A BELT OF WEAK-MODERATE INSTABILITY IS EXPECTED TODAY ALONG A LOW-LEVEL BAROCLINIC ZONE FROM SRN LOWER MI INTO CENTRAL PA. DEBRIS CLOUDS MAY LIMIT SURFACE HEATING ACROSS LOWER MI EARLY TODAY...BUT A FEW THUNDERSTORM CLUSTERS ARE STILL EXPECTED INVOF THE SURFACE BOUNDARY. DEEP LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR BOTH SUPERCELLS AND BOWING SEGMENTS...THE STRONGEST OF WHICH COULD PRODUCE A FEW DAMAGING GUSTS AND MARGINALLY SEVERE HAIL. ...PLAINS AREA THIS AFTERNOON INTO EARLY TONIGHT... A BROAD AREA OF THUNDERSTORMS ASSOCIATED WITH LOW-LEVEL WAA AND A 40-50 KT LLJ IS ONGOING ACROSS MO TO THE E OF THE MOISTURE/INSTABILITY ACROSS FROM ERN OK INTO ERN KS. SURFACE HEATING AND BOUNDARY LAYER DEWPOINTS OF 65-70 F ALONG A SLOW MOVING COLD FRONT IN KS WILL RESULT IN MODERATE INSTABILITY BY AFTERNOON WHEN SURFACE-BASED THUNDERSTORM DEVELOPMENT IS EXPECTED. STEEP LOW-LEVEL LAPSE RATES AND MLCAPE VALUES OF 1500-2000 J/KG WILL SUPPORT A THREAT FOR WIDELY SCATTERED DOWNBURSTS AND SOME HAIL THIS AFTERNOON/EVENING ALONG AND S OF THE FRONT. N OF THE BOUNDARY...LOW-LEVEL NELY FLOW BENEATH 25-30 KT SWLY MID LEVEL FLOW WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR SOME SUPERCELL STRUCTURES FROM EXTREME SE CO ACROSS WRN/CENTRAL KS. CONVECTION WILL EVENTUALLY BECOME RATHER WIDESPREAD ALONG AND N OF THE FRONT...THUS THE SEVERE STORM THREAT IS EXPECTED TO DIMINISH BY LATE EVENING. ...NE UT/NW CO/SW WY AREA TODAY... THE MID LEVEL TROUGH OVER ERN ORE/WA AND ID THIS MORNING WILL DIG SLOWLY SEWD TOWARD NE NV/NW UT BY EARLY SATURDAY. ASCENT IN ADVANCE OF THE MID LEVEL TROUGH...ALONG WITH NW EDGE OF THE MONSOONAL MOISTURE PLUME...WILL SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT FROM NE UT INTO SW WY AND NW CO TODAY INTO EARLY TONIGHT. STEEP L0W-MID LEVEL LAPSE RATES...LOW-LEVEL DEWPOINTS OF 45-50 F...AND MODEST SWLY MID LEVEL FLOW SHOULD BE SUFFICIENT FOR A FEW STORMS WITH STRONG/DAMAGING OUTFLOW WINDS AND MARGINALLY SEVERE HAIL. ..THOMPSON/GUYER.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 16:49:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 12:49:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251650 SWODY1 SPC AC 251648 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 AM CDT FRI AUG 25 2006 VALID 251630Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT LAKES REGION SEWD INTO THE NRN MID ATLANTIC AREA...AND ACROSS THE CENTRAL PLAINS.... ...SYNOPSIS... SEVERAL MID/UPPER LEVEL LOWS DEFINE THE PATTERN WITH ONE OVER THE NRN PLATEAU...ANOTHER OVER CENTRAL/SOUTH CENTRAL CANADA AND THE OTHER OVER CENTRAL/EASTERN QUEBEC. THIS PLACES THE MAIN STORM TRACK FROM NRN NEVADA NEWD THRU WY...THEN EWD ACROSS THE UPPER GREAT LAKES THEN SEWD THRU THE LOWER GREAT LAKES INTO THE NRN MID ATLANTIC REGION. THE LATEST SURFACE ANALYSIS EXTENDS A WARM FRONT FROM A LOW OVER SERN MN EWD/SEWD ACROSS SRN WI INTO SERN LOWER MI...THEN CONTINUES AS A QUASI STATIONARY FRONT THRU NERN OH THRU NRN NJ. IN ADDITION...A WEAK COLD FRONT EXTENDS FROM THE MN LOW SWWD ACROSS SWRN IA AND NERN KS THEN WWD THRU EXTREME SWRN KS AND SRN CO. ...SRN WI ESEWD ACROSS NERN OH INTO NJ... MODELS ARE ALL IN FAIR AGREEMENT OF DEVELOPING STRONG CONVECTION OVER PARTS OF SRN LOWER MI INTO NERN OH/NWRN PA AND AGAIN FROM NERN PA INTO NJ LATER THIS AFTERNOON AND TONIGHT. MODELS DO NOT DEVELOP ANY LOW LEVEL FLOW TOWARDS THE QUASI-STATIONARY BOUNDARY ACROSS THIS REGION...BUT DOES HAVE A FAVORABLE ENTRANCE REGION OF THE MID/UPPER LEVEL JET STREAK THAT IS FORECAST FROM SRN LK HURON OVER SWRN AND SERN NY. IT ALSO LOOKS LIKE THE MODELS WANT TO TAKE THE CONVECTION CURRENTLY OVER SRN WI AND TRACK IT EWD/SEWD INTO THIS AREA. THE 15Z RUC IS CONSISTENT WITH THIS SCENARIO...DESTABILIZING THE AIR MASS WITH SBCAPE BETWEEN 1500-2000 J/KG WITH DEEP LAYER SHEAR OF 45-55 KT. ANALYSIS OF MODEL SOUNDINGS FOR CLE SUGGESTS MID LEVEL LAPSE RATES NEAR 7C/KM WITH MID LEVEL DRYING PRESENT SUGGESTS THAT STORMS THAT DO DEVELOP IN WNWLY FLOW ALOFT HAVE THE POTENTIAL FOR DAMAGING WINDS AND HAIL THAT CAN TRACK/REDEVELOP ESEWD ACROSS PA/SRN NY STATE INTO NJ TONIGHT. GIVEN THE VERTICAL PROFILES ARE FAVORABLE FOR ISOLATED SUPERCELLS /0-3KM HELICITY NEAR 300 M2/S2/...AN ISOLATED TORNADO IS POSSIBLE NEAR/JUST N OF THE BOUNDARY. ...SRN WI SWWD INTO THE GREAT PLAINS... AIR MASS IS VERY WARM...MOIST AND MODERATELY UNSTABLE AT THIS TIME ALONG AND AHEAD OF FRONTAL BOUNDARY. MLCAPE IS CURRENTLY 1500-2500 J/KG FROM CENTRAL KS ENEWD INTO S CENTRAL IA. MODELS ENHANCE UVVS ACROSS MUCH OF THE CENTRAL PLAINS IN THE VICINITY OF THE BOUNDARY S OF UPPER LEVEL JET STREAK OF 80-100 KT. MODELS DO DEVELOP NOCTURNAL LOW LEVEL JET OF 40 KT FROM SWRN OK INTO SERN KS WHICH WILL ENHANCE LOW LEVEL ASCENT NEAR THE BOUNDARY. SO...MODELS MAY HAVE A GOOD HANDLE ON DEVELOPING SCATTERED STRONG /SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. LOOK FOR ACTIVITY TO CONTINUE FROM NRN IL SWWD INTO NERN MO...BUT FOR MORE DEVELOPMENT IN VICINITY OF OLD CONVECTIVE BOUNDARIES FROM NWRN IL INTO KS DEVELOPING INTO AN MCS OVERNIGHT. POTENTIAL INSTABILITY WITH SBCAPE FORECAST BETWEEN 3000-4000 J/KG IS EXPECTED BY TONIGHT AND STEEP MID LEVEL LAPSE RATES BETWEEN 7-7.5C/KM INDICATES DAMAGING WINDS AND HAIL BEING THE MAIN THREATS. ...CENTRAL INTERMOUNTAIN REGION... NAM/RUC MID LEVEL TEMPERATURES ARE FORECAST TO CHANGE LITTLE LATER TODAY WITH VALUES BEING AROUND -16C IN ASSOCIATION WITH MID/UPPER LEVEL LOW MOVING SSEWD FROM CENTRAL ID INTO NERN NV/NWRN UT/S CENTRAL ID BY THE END OF THE PERIOD. RUC MODEL IS MORE UNSTABLE THAN THE NAM AND ANALYSIS OF THE FORECAST SOUNDING DO INDICATE A MUCH DRIER BOUNDARY LAYER ON THE NAM THAN COMPARED TO THE RUC. THUS...EXPECT SOME STORMS TO DEVELOP BY THIS EVENING POSSIBLY PRODUCING SOME STRONG WINDS ACROSS PARTS OF NRN UT GIVEN THAT VERTICAL PROFILES INDICATE AN INVERTED-V ASPECT. ..MCCARTHY.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 20:03:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 16:03:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 252002 SWODY1 SPC AC 252000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT FRI AUG 25 2006 VALID 252000Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL/SRN HIGH PLAINS TO GREAT LAKES/NRN OH VALLEY...AND THEN SEWD TO THE MID ATLANTIC COAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN UT...NWRN CO AND SWRN WY... ...UPPER MIDWEST/SRN GREAT LAKES TO MID ATLANTIC COAST... LATEST MESOANALYSIS INDICATED A SURFACE LOW OVER NERN IA/SWRN WI WITH AN ATTENDANT WARM OR QUASI-STATIONARY BOUNDARY EXTENDING EWD THROUGH CNTRL LOWER MI AND THEN MORE ESEWD FROM NEAR BUF TO CNTRL NJ. A COLD FRONT THEN STRETCHED SWWD FROM THIS LOW THROUGH S-CNTRL IA. BREAKS IN THE CLOUDS FROM SERN WI/NRN IL INTO ERN IA HAVE ALLOWED BOUNDARY LAYER TO WARM TO 75-85 F AND WHEN COUPLED WITH DEW POINTS IN THE UPPER 60S TO LOWER 70S...AIR MASS HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-2000 J/KG. CONVERGENCE ALONG THESE BOUNDARIES IN CONJUNCTION WITH INFLUENCE OF WEAKENING SHORT WAVE TROUGH OVER NRN/CNTRL WI INTO NRN LOWER MI HAVE CONTRIBUTED TO INCREASING STORM COVERAGE AND INTENSITY OVER SRN WI/NRN IL. LOCAL VADS INDICATE MODEST VERTICAL SHEAR OF 30-35 KTS WHICH IS SUFFICIENT TO SUPPORT ORGANIZED UPDRAFTS GIVEN THE MODERATE INSTABILITY. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY SEVERE WEATHER THREATS WITH THESE STORMS. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1883. ADDITIONAL STORMS WILL BE POSSIBLE FARTHER TO THE E OVER CNTRL/SRN LOWER MI...EVENTUALLY INTO THE UPPER OH VALLEY LATER THIS AFTERNOON INTO TONIGHT AS AFOREMENTIONED SHORT WAVE TROUGH CONTINUES EWD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS HAS LIMITED AIR MASS DESTABILIZATION THUS FAR TODAY...AND THIS MAY CONTINUE TO BE A FACTOR WHICH LIMITS OVERALL SEVERE THREAT. HOWEVER...SHOULD STORMS DEVELOP AND BECOME SUSTAINED...SUFFICIENT VERTICAL SHEAR WILL EXIST FOR A FEW SEVERE STORMS CAPABLE OF HIGH WINDS AND SOME HAIL. FARTHER SE OVER ERN PA/NJ...REGION APPEARS TO BE IN SOME DEGREE OF LARGE SCALE SUBSIDENCE IN WAKE OF SHORT WAVE TROUGH WHICH PASSED THROUGH EARLIER TODAY. ABUNDANT SUNSHINE MAY STILL ALLOW FOR THE RE-DEVELOPMENT OF STORMS LATE THIS AFTERNOON OR EVENING ALONG PRE-EXISTING LOW-LEVEL BOUNDARY. SHOULD STORMS DEVELOP...DEEP NWLY FLOW WILL SUPPORT SOME DAMAGING WIND POTENTIAL WITH THE MORE ORGANIZED CELLS. ...CNTRL/SRN HIGH PLAINS TO LOWER MO VALLEY... TRAILING PORTION OF COLD FRONT EXTENDED SWWD THROUGH NWRN MO TO SECONDARY LOW PRESSURE OVER S-CNTRL KS AND WSWWD INTO NERN NM AS OF 19Z. RELATIVELY CLOUD FREE SKIES S OF THIS BOUNDARY HAVE ALLOWED FOR STRONG DIABATIC HEATING WITHIN MOIST BOUNDARY LAYER WHERE MLCAPES HAVE INCREASED TO 2000-3000 J/KG WITH A RAPIDLY WEAKENING CAP. THIS DESTABILIZATION COUPLED WITH INCREASED FORCING FOR ASCENT ASSOCIATED WITH SHORT WAVE TROUGH SHIFTING EWD OUT OF ERN CO SHOULD SUPPORT AN INCREASE IN TSTM COVERAGE ALONG FRONT LATE THIS AFTERNOON INTO EVENING. PROFILER/VAD OBSERVATIONS INDICATE VERTICAL SHEAR SUPPORTIVE OF SUPERCELLS OVER SERN CO/SWRN KS...WITH A GENERAL DECREASE WITH NEWD EXTENT ACROSS KS INTO MO. THE STRONGEST STORMS WILL BE CAPABLE OF LARGE HAIL GIVEN THE STEEP MID-LEVEL LAPSE RATES AND ROTATIONAL UPDRAFT POTENTIAL...AS WELL AS LOCALLY DAMAGING WIND GUSTS. THE SEVERE THREAT SHOULD DIMINISH BY LATE EVENING AS BOUNDARY LAYER COOLS AND STABILIZES. ...UT/SRN WY/WRN CO... VISIBLE SATELLITE IMAGERY AND RADAR DATA INDICATE TSTMS DEVELOPING ALONG THE ERN SLOPES OF THE WASATCH THIS AFTERNOON IN RESPONSE TO APPROACH OF SHORT WAVE TROUGH THROUGH ERN NV INTO WRN UT. WHILE BOUNDARY LAYER IS NOT PARTICULARLY WARM OR MOIST...THE PRESENCE OF STEEP LOW TO MID LEVEL LAPSE RATES ARE CONTRIBUTING TO MODERATE INSTABILITY WITH MLCAPES OF 500-1500 J/KG. INCREASING MID AND HIGH-LEVEL WIND FIELDS IN ASSOCIATION WITH APPROACHING IMPULSE ARE RESULTING IN SUFFICIENT VERTICAL SHEAR FOR SOME STORM ORGANIZATION/ROTATION. ISOLATED SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE GREATEST THREATS WITH THESE MORE INTENSE STORMS. ..MEAD.. 08/25/2006  From swody1 at goshenarc.org Sat Aug 26 01:08:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 21:08:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260108 SWODY1 SPC AC 260106 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0806 PM CDT FRI AUG 25 2006 VALID 260100Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SCNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN UT AND NWRN CO... ...THERE IS A SLGT RISK OF SVR TSTMS OVER SWRN NY AND NWRN PA... ...SCNTRL PLAINS... QUASI-STATIONARY FRONTAL ZONE BISECTS THE SCNTRL PLAINS FROM THE TX PNHDL NEWD ACROSS KS...TO NRN MO. WIDESPREAD DEEP CONVECTION HAS DEVELOPED IN VARIOUS REGIMES ACROSS THIS REGION...FROM HOT AND DEEPLY MIXED BOUNDARY LAYER AIR MASS AHEAD OF THE FRONT...OVER NRN OK/SRN KS...TO STRONGLY UNSTABLE POST-FRONTAL AIR MASS...ALONG THE NEB/KS BORDER. MOST INTENSE AND LONG-LIVED STORMS HAVE BEEN ON OR NEAR THE FRONTAL WIND SHIFT FROM SWRN KS TO NWRN MO. LARGE SCALE MID/UPPER LEVEL DIFFLUENCE ATOP ABUNDANTLY MOIST/UNSTABLE AIR MASS ACROSS THE BOUNDARY SHOULD SUSTAIN VIGOROUS STORMS WITH HAIL AND HIGH WINDS WELL INTO THE NIGHT. GENERALLY WEAK LOW LEVEL FLOW TOPPED BY 30KT MID LEVEL FLOW WAS RESULTING IN SUFFICIENT BULK SHEAR FOR UPDRAFT PERSISTENCE AND ROTATION. MAGNITUDE OF LOW LEVEL CAPE AND ENHANCED SHEAR NEAR AND NORTH OF THE SURFACE FRONT/WIND SHIFT COULD SUPPORT A BRIEF TORNADO OR TWO FROM CELLS TRACKING NEAR/ALONG THE FRONT. ...ERN UT/NWRN CO... UPPER TROUGH OVER THE NRN GREAT BASIN WILL CONTINUE TO DIG SEWD TONIGHT AND INDUCE WIDESPREAD ASCENT ACROSS THE NCNTRL ROCKIES. NUMEROUS HIGH-BASED STORMS IN LOW-CAPE BUT MODESTLY SHEARED ENVIRONMENT WILL CONTINUE TO POSE A THREAT OF MARGINALLY SEVERE HAIL AND DAMAGING DOWNBURSTS. THIS ACTIVITY WILL GRADUALLY WANE THROUGH LATE EVENING AS LOW LEVELS STABILIZE AND BOUNDARY LAYER LAPSE RATES WEAKEN. ...WRN NY/NWRN PA... TSTMS HAVE RECENTLY INCREASED AHEAD OF LOW-AMPLITUDE SHORT WAVE IMPULSE TRACKING SEWD ACROSS LAKES ERIE/ONTARIO. THIS IMPULSE WAS LIKELY AIDING DEEP LAYER ASCENT AND DESTABILIZATION IN A NARROW ZONE FROM NWRN PA INTO WRN NY WHERE DIAGNOSTIC DATA AND EVENING SOUNDINGS SUGGEST STRONG DEEP LAYER SHEAR EXISTS. SOUNDINGS ALSO DEPICT RELATIVELY WEAK MID LEVEL LAPSE RATES BUT MAY NOT BE TRULY SAMPLING THE SMALL SCALE ENVIRONMENT BETWEEN PIT AND BUF WHERE CONVECTION IS EXPECTED TO PERSIST. GIVEN LATEST TRENDS IN REFLECTIVITY...AND MODEL GUIDANCE SUGGESTING AN INCREASE IN CONVECTION ACROSS THE NY/PA BORDER THROUGH LATE TONIGHT...A SMALL SLGT RISK WILL BE MAINTAINED. MARGINALLY SEVERE HAIL APPEARS TO BE THE PRIMARY HAZARD AT THIS TIME BUT A BRIEF SEVERE WIND GUST OR TORNADO COULD OCCUR IF A ROBUST CELL CAN TRACK PREFERENTIALLY ALONG THE SURFACE BOUNDARY SITUATED ACROSS NWRN PA/WRN NY. ...UPPER MIDWEST... DESPITE STRONG INSTABILITY AND FOCUSED LOW LEVEL FORCING ALONG THE FRONT...AND NEAR WEAK FRONTAL WAVE OVER ERN IA/NRN IL...TSTMS ACROSS THESE AREAS HAVE REMAINED POORLY ORGANIZED SINCE EARLY EVENING. WEAK LARGE SCALE SUPPORT /SHORT WAVE RIDGING ALOFT/ AND SLOW DIURNAL DECREASE IN INSTABILITY SHOULD INHIBIT A MORE WIDESPREAD SEVERE THREAT. AN ISOLATED HAIL AND/OR WIND EVENT REMAINS POSSIBLE GIVEN FRONTAL LIFT OCCURRING IN MOIST AND UNSTABLE ENVIRONMENT. HOWEVER... OVERALL PROBABILITY DOES NOT WARRANT CONTINUING A SLGT RISK IN THIS AREA. ..CARBIN.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 05:51:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 01:51:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260551 SWODY1 SPC AC 260550 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CDT SAT AUG 26 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GREAT BASIN/CNTRL ROCKIES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE MIDWEST AND PARTS OF THE ERN GREAT LAKES TO DELMARVA... ...SYNOPSIS... COMPLEX SYNOPTIC FLOW REGIME WILL EVOLVE ACROSS THE CONUS THIS PERIOD WITH A NUMBER OF DIFFERENT STREAMS COMPOSED OF RELATIVELY HIGH-AMPLITUDE MID/UPPER LEVEL WAVES. WITHIN THIS FLOW WILL ALSO EXIST A NUMBER OF SMALLER-SCALE PERTURBATIONS EMANATING FROM EPISODES OF WIDESPREAD DEEP CONVECTION. PRIMARY LARGE SCALE FEATURES DRIVING DEEP CONVECTION WILL INCLUDE MID/UPPER LOW DEVELOPING ACROSS THE ERN GREAT BASIN...A QUASI-STATIONARY FRONT FROM THE SRN HIGH PLAINS NEWD TO THE MIDWEST/LOWER MI...AND A BACK DOOR FRONT FROM PA INTO DELMARVA AREA. ...ERN GREAT BASIN TO CNTRL ROCKIES... A MIDDLE STREAM UPPER LOW WILL CONTINUE TO TRANSLATE EAST FROM THE GREAT BASIN TO THE ROCKIES TODAY. MODEST HEIGHT FALLS...MID LEVEL COLD POOL...AND BAND OF 30-40KT DIFFLUENT MID LEVEL FLOW WILL SPREAD EAST FROM UT TO WY/CO THIS AFTERNOON. TSTMS SHOULD INCREASE AS THE SYSTEM MOVES ACROSS UT THROUGH THE AFTERNOON. SIMILAR TO FRIDAY....STEEP LAPSE RATES AND MOISTENING DUE TO STRONG DPVA WILL SUPPORT MODEST INSTABILITY WITHIN SUFFICIENTLY SHEARED ENVIRONMENT FOR PERSISTENT/ORGANIZED STORMS. SUPERCELLS APPEAR LIKELY AND WILL BE CAPABLE OF PRODUCING HAIL AND HIGH WINDS. ...SRN PLAINS TO MIDWEST... FROM THE HIGH PLAINS TO THE MID WEST...STALLED SYNOPTIC BOUNDARY WILL BE INTERSPERSED WITH NUMEROUS CONVECTIVE OUTFLOWS FROM CO/NM ENEWD ACROSS KS/OK...AND NEWD TO IL. MCS NOW MOVING ACROSS MO WILL LIKELY INDUCE AN MCV IMPULSE THAT MAY TRACK DOWNSTREAM AND ACROSS THE MS VALLEY TO THE MIDWEST THROUGH THE DAY. LIFT ASSOCIATED WITH THIS IMPULSE WILL ACT ON INCREASINGLY UNSTABLE AIR MASS FROM IL TO IND. ON THE LARGE SCALE...SHEAR REMAINS WEAK ACROSS THESE AREAS. HOWEVER...FORCING WITH THE MCV AND MAGNITUDE OF INSTABILITY SHOULD PROVOKE A FEW SEVERE STORMS WITH HAIL AND HIGH WINDS. IN THE WAKE OF THIS SYSTEM...CLEARING CONVECTIVE DEBRIS ACROSS WRN MO/KS AND OK...WILL AGAIN RESULT IN STRONG INSTABILITY ACROSS THESE AREAS. FRONTAL BOUNDARY AND OUTFLOWS WILL PROVIDE A FOCUS FOR AFTERNOON AND EVENING TSTMS. BELT OF 30-40KT MID LEVEL FLOW WILL PROVIDE ADEQUATE EFFECTIVE SHEAR ACROSS THE REGION FOR A FEW SUPERCELLS AND ORGANIZED STORM CLUSTERS WITH DAMAGING WINDS AND HAIL. ACTIVITY MAY MERGE AND GROW UPSCALE INTO A SLOW MOVING MCS OR TWO THROUGH SUNDAY MORNING. ...LOWER MI... IN THE NRN STREAM...TROUGH CROSSING SCNTRL CANADA WILL BRUSH PARTS OF THE UPPER MS VALLEY AND NRN GREAT LAKES. WHILE STRONGER HEIGHT FALLS WITH THIS SYSTEM WILL REMAIN PRIMARILY NORTH OF THE BORDER...A BAND OF SLIGHTLY STRONGER MID LEVEL WLY FLOW WILL DEVELOP EWD ACROSS LOWER MI...COINCIDENT WITH DIURNAL HEATING AND FRONTAL PASSAGE OVER THIS AREA. A FEW SEVERE STORMS WITH HAIL AND WIND APPEAR POSSIBLE ACROSS THIS AREA DURING THE AFTERNOON/EARLY EVENING. ...LAKE ERIE TO DELMARVA... NW-SE ORIENTED FRONTAL BAND WILL CONTINUE TO SEPARATE CONTINENTAL POLAR AIR MASS OVER NEW ENGLAND FROM RETURNING TROPICAL MARITIME AIR ACROSS THE OH VALLEY. LOW AMPLITUDE PERTURBATIONS IN NW FLOW ALOFT WILL ENHANCE ASCENT ALONG THE LOW LEVEL BOUNDARY AND LEAD TO SCATTERED TSTM DEVELOPMENT DURING THE DAY. PART OF THE BOUNDARY MAY SETTLE FARTHER SWWD INTO INCREASINGLY UNSTABLE AIR ACROSS SRN PA/WV PNHDL AND DELMARVA AREAS THROUGH THE EVENING. DIRECTIONAL SHEAR ALONG THE BOUNDARY...AS WELL AS DEEP LAYER VERTICAL SPEED SHEAR...WILL ENHANCE STORM UPDRAFTS WITH A FEW HAIL/WIND EVENTS POSSIBLE. ..CARBIN.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 12:35:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 08:35:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261235 SWODY1 SPC AC 261233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0733 AM CDT SAT AUG 26 2006 VALID 261300Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR NE IL...NW INDIANA...AND SRN LOWER MI... ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE TX PANHANDLE...NRN OK...SE KS...NW AR...AND SW MO... ...THERE IS A SLGT RISK OF SVR TSTMS FOR NE UT...WRN CO...SW WY... ...SYNOPSIS... A MID LEVEL TROUGH OVER THE GREAT BASIN...WITHIN A SRN STREAM OF THE WLYS...WILL MOVE SLOWLY ESEWD OVER UT TO WRN CO BY THE END OF THE PERIOD. A SEPARATE WAVE IN THE NRN STREAM WILL PROGRESS EWD FROM MANITOBA/WRN ONTARIO TOWARD WRN QUEBEC. IN ASSOCIATION WITH THESE FLOW STREAMS...A LOW-LEVEL BAROCLINIC ZONE EXTENDS WNWWD FROM THE NRN MID ATLANTIC REGION TO SRN LOWER MI...AND THEN SWWD ACROSS NRN MO/NW OK TO ERN NM. ONLY SLOW SEWD MOTION OF THIS FRONT IS EXPECTED ACROSS THE PLAINS/MS VALLEY IN THE WAKE OF THE NRN STREAM TROUGH...AND THE MID ATLANTIC PORTION OF THE BOUNDARY SHOULD REMAIN QUASI-STATIONARY. ...IL TO SRN LOWER MI... A LARGE CLUSTER OF THUNDERSTORMS OVER MO/WRN IL HAS PRODUCED AN MCV OVER NE MO WHICH SHOULD MOVE ENEWD OVER IL TODAY AND INDIANA/OH TONIGHT. BOUNDARY LAYER DEWPOINTS OF 68-72 F WILL SPREAD NEWD IN ADVANCE OF A WEAK WAVE ON THE SURFACE FRONT ACROSS NRN IL...PROVIDING SUFFICIENT INSTABILITY TO MAINTAIN THUNDERSTORM CLUSTERS THROUGH TONIGHT ALONG THE PATH OF THE MCV. MODEST VERTICAL SHEAR ASSOCIATED WITH MCV AND NEAR THE SURFACE FRONT ACROSS LOWER MI MAY SUPPORT A FEW SEVERE STORMS/MARGINAL SUPERCELLS TODAY. DAMAGING WINDS SHOULD BE THE MAIN SEVERE THREAT...ALONG WITH MARGINALLY SEVERE HAIL. ...SRN PLAINS... WIDESPREAD OVERNIGHT AND ONGOING CONVECTION HAS REDUCED MID LEVEL LAPSE RATES OVER A BROAD AREA IMMEDIATELY N OF THE FRONT ACROSS KS/MO...WITH THE STEEPER LOW-MID LEVEL LAPSE RATES CONFINED TO A BAND ALONG AND S OF THE FRONT WHERE STRONG SURFACE HEATING AND DEEP MIXING HAS OCCURRED THE PAST TWO DAYS. A FEW STRONG/SEVERE STORMS SHOULD FORM ALONG THE FRONT AND REMNANT OUTFLOW BOUNDARIES THIS AFTERNOON...NEAR THE SRN FRINGE OF THE ONGOING CONVECTION THIS MORNING. THESE STORMS WILL BE CAPABLE OF PRODUCING ISOLATED DAMAGING DOWNBURST WINDS AND MARGINALLY SEVERE HAIL. OVERALL...THE SEVERE STORM THREAT APPEARS MARGINAL AND IS REDUCED COMPARED TO FRIDAY. ...UT/CO AREA... A BELT OF ASCENT WILL CONTINUE TO SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT TODAY OVER NRN/ERN UT INTO WRN CO AND SW WY...IN ADVANCE OF A MID LEVEL TROUGH MOVING ESEWD FROM SW ID/NE NV. STEEP LOW-MID LEVEL LAPSE RATES AND 500 MB TEMPERATURES APPROACHING -15 C WILL SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL TODAY ACROSS NRN UT. THE STRONGER VERTICAL SHEAR AND POTENTIAL FOR MORE ORGANIZED STORM TYPES IS EXPECTED THIS AFTERNOON OVER NERN UT INTO WRN CO. HERE...THE STRONGER STORMS MAY PRODUCE ISOLATED LARGE HAIL AND STRONG OUTFLOW WINDS. ...MID ATLANTIC AREA... CONVECTION AND AN ASSOCIATED MID LEVEL WAVE WILL MOVE OFFSHORE EARLY THIS MORNING. SHORTWAVE RIDGING IS EXPECTED THROUGH MUCH OF THE PERIOD OVER THIS AREA...WITH ONLY SPARSE THUNDERSTORM COVERAGE ANTICIPATED NEAR THE NW-SE ORIENTED SURFACE FRONT. VERY ISOLATED STRONG WIND GUSTS OR HAIL CANNOT BE RULED OUT...BUT THE OVERALL THREAT APPEARS INSUFFICIENT TO WARRANT A SLIGHT RISK. ..THOMPSON/TAYLOR.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 16:40:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 12:40:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261639 SWODY1 SPC AC 261637 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CDT SAT AUG 26 2006 VALID 261630Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVENING ACROSS LOWER MI INTO NERN IL AND NRN IN.... ...THERE IS A SLGT RISK OF SVR TSTMS THRU TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY TONIGHT ACROSS PARTS OF THE CENTRAL ROCKIES.... ...SYNOPSIS... MID/UPPER LEVEL LOW MOVG SEWD INTO THE CENTRAL INTERMOUNTAIN REGION WILL TURN EWD LATER TODAY AND TONIGHT INTO WY/CO. MID/UPPER LEVEL SHORTWAVE TROUGH WILL BE SKIRTING EWD ACROSS ONTARIO AND THE NRN GREAT LAKES AS MID/UPPER LEVEL RIDGING REMAINS OVER THE SERN QUARTER OF THE U.S. MORNING SURFACE ANALYSIS SHOWS WEAKENING LOW PRESSURE OVER SERN WI WITH A COLD FRONT EXTENDING SWWD INTO NWRN MO...THEN BECOMING QUASI-STATIONARY ACROSS NERN KS INTO THE TX PANHANDLE. SEVERAL OLD CONVECTIVE BOUNDARIES ARE DRAPED ACROSS CENTRAL AR...THRU CENTRAL OK INTO W CENTRAL TX. ALSO...A WARM FRONT REMAINS FROM THE WI LOW EWD THRU CENTRAL LOWER MI...THEN IS MORE QUASI-STATIONARY SEWD THRU NWRN PA AND SRN NJ. ...LOWER MI SSWWD INTO PARTS OF IL AND IN... SFC LOW OVER SERN WI IS FORECAST TO MOVE NEWD INTO NWRN LOWER MI THRU LATE THIS AFTERNOON DRAGGING ASSOCIATED COLD FRONT THRU NERN IL INTO CENTRAL MO. STRONG THUNDERSTORMS ARE CURRENTLY MOVING ACROSS NWRN SECTIONS OF LOWER MI IN AREA WITH DEEP LAYER SHEAR AT APPROXIMATELY 40 KT. CLOUD COVER IS LIMITING POTENTIAL INSTABILITY AT THIS TIME WITH MLCAPES BETWEEN 500 AND 1000 J/KG. PRESENCE OF SUFFICIENT SHEAR MAY SUPPORT WEAK SUPERCELLS THROUGH THIS REGION INTO EARLY THIS AFTERNOON. THERE MAY BE ENOUGH HEATING/LOW LEVEL WARM ADVECTION LATER OVER E CENTRAL LWR MI THAT MAY ALLOW MORE THERMODYNAMICS THAT MAY AID IN HAIL AND DAMAGING WINDS. ...PARTS OF THE CENTRAL PLAINS... AIR MASS ACROSS THIS AREA REMAINS QUITE WARM AND MOIST AS SURFACE DEW POINTS ARE IN THE UPPER 60S/LOWER 70S. THE PRESENCE OF OLD CONVECTIVE OUTFLOWS FROM THE TX PANHANDLE INTO AR MAY A PLAY ROLE TO ENHANCE LIFT AS DAYTIME HEATING WILL DESTABILIZE THE AIR MASS FOR MLCAPES TO REACH TO 1500-2000 J/KG. THE HEATING WILL ALSO STEEPEN LOW-MID LEVEL LAPSE RATES ACROSS THIS REGION TO BETWEEN 7.0 TO 9.0C/KM. THUS...WIDELY SCATTERED STRONG/SEVERE THUNDERSTORMS ARE EXPECTED WITH THE MAIN THREAT BEING STRONG DOWNBURSTS POSSIBLY ACCOMPANIED BY SOME HAIL. ...INTERMOUNTAIN REGION... MID/UPPER LEVEL LOW WITH MID LEVEL TEMPERATURES AROUND -14 TO -16C WILL TRANSLATE ESEWD ACROSS UT INTO WY/CO DURING THE PERIOD. MOST NOTABLE IN THE ANALYSIS OF THE LATEST RUC SOUNDINGS IS THE MID LEVEL DRYING THAT WILL ACCOMPANY THE LOW. STEEP MID LEVEL LAPSE RATES OF 7-8C/KM WILL BE ACROSS PARTS OF ERN UT INTO WRN CO SUFFICIENT TO SUPPORT HAIL AND DAMAGING WINDS WITH THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY TONIGHT. ..MCCARTHY/GRAMS.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 19:54:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 15:54:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261954 SWODY1 SPC AC 261952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0252 PM CDT SAT AUG 26 2006 VALID 262000Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE GREAT LAKES AND OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL AND SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE INTERMOUNTAIN WEST... ...GREAT LAKES INTO OH VALLEY... FORCING FOR UPWARD VERTICAL MOTION IS BEING ENHANCED THIS AFTERNOON BY: 1) SHORT WAVE TROUGH AND ASSOCIATED SPEED MAX OVER THE U.P. AND LAKE MI...AND 2) MCV OVER NRN/CNTRL IL. WHILE CONSIDERABLE CLOUDS HAVE LIMITED DIABATIC HEATING AND RESULTANT DESTABILIZATION...MOIST BOUNDARY LAYER CONDITIONS ARE CONTRIBUTING TO MLCAPES OF 500-1000 J/KG FROM LOWER MI INTO IL/IND. THE STRONGEST STORMS THUS FAR TODAY HAVE BEEN LOCATED OVER PARTS OF LOWER MI INVOF SURFACE LOW MOVING INTO THE W-CNTRL PART OF THE STATE. MESOANALYSIS INDICATES THAT ATTENDANT WARM FRONT EXTENDS FROM THIS LOW EWD TO N OF RBQ AND THEN SEWD TO NEAR MTC. SHEAR PROFILES ALONG THIS BOUNDARY ARE SUPPORTIVE OF SUPERCELLS OWING TO PRONOUNCED LOW-LEVEL HODOGRAPH CURVATURE AND AROUND 35 KTS OF EFFECTIVE BULK SHEAR. FURTHER AIR MASS DESTABILIZATION AND APPROACH OF IMPULSES FROM THE NW AND SW SHOULD CONTRIBUTE TO INCREASED COVERAGE AND INTENSITY OF STORMS OVER LOWER MI THIS AFTERNOON INTO EVENING WITH THE MAIN THREAT BEING SEVERE HAIL AND LOCALLY DAMAGING WINDS. GREATEST POTENTIAL FOR A TORNADO OR TWO WILL BE WITH ANY SURFACE-BASED SUPERCELLS THAT CAN FAVORABLY INTERACT WITH SURFACE WARM FRONT. ADDITIONAL STRONG TO POTENTIALLY SEVERE STORMS WILL BE POSSIBLE SWWD ALONG TRAILING COLD FRONT INTO PORTIONS OF NRN IL...AS WELL AS AHEAD OF MCV INTO IND/OH WHERE STRONGER DESTABILIZATION IS OCCURRING. VERTICAL SHEAR REMAINS COMPARATIVELY WEAKER THAN POINTS TO THE N...WITH THE MAIN THREATS BEING MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS WITH ORGANIZED MULTICELL CLUSTERS. ...SERN KS/OK INTO THE TX PNHDL/NWRN TX... VISIBLE SATELLITE AND MESOANALYSIS INDICATE THAT OUTFLOW FROM NOCTURNAL CONVECTION HAS ESTABLISHED A BOUNDARY WELL S OF PRIMARY SYNOPTIC FRONT FROM CNTRL AR WWD TO CNTRL OK AND THEN SWWD TO NEAR ABI. THE MAIN COLD FRONT EXTENDED FROM NEAR CNU TO NEAR PVW AS OF 18Z. WHILE 12Z REGIONAL SOUNDINGS INDICATED THAT MID-LEVEL LAPSE RATES WERE RELATIVELY POOR /AROUND 6.5 C/KM/...DAYTIME HEATING AND DEWPOINTS OF 65-70 F ARE CONTRIBUTING TO DESTABILIZATION OF PRE-FRONTAL AIR MASS WITH MLCAPES LIKELY REACHING 2000-3000 J/KG LATER THIS AFTERNOON. WHILE LARGE-SCALE FORCING FOR ASCENT IS EXPECTED TO REMAIN RATHER WEAK...CONVERGENCE ALONG THE LOW-LEVEL BOUNDARIES SHOULD SUPPORT AN INCREASE IN STORM COVERAGE AND INTENSITY BOTH ALONG THE OUTFLOW BOUNDARY AND MAIN FRONT. AREA VWPS AND PROFILERS INDICATE THAT VERTICAL SHEAR IS MARGINAL FOR STORM ORGANIZATION...WITH MULTICELL CLUSTERS THE MOST LIKELY CONVECTIVE MODE. THE STRONGEST STORMS WILL BE CAPABLE OF SEVERE HAIL AND DAMAGING WIND GUSTS. ...INTERMOUNTAIN WEST... AFTERNOON WATER VAPOR IMAGERY INDICATES MID/UPPER LOW MOVING SEWD INTO NRN UT WITH STRONGEST HEIGHT FALLS SHIFTING ACROSS ERN UT INTO WRN CO. TSTMS ARE RAPIDLY INCREASING IN COVERAGE THIS AFTERNOON WITHIN THIS ZONE OF HEIGHT FALLS WHERE STEEP LAPSE RATES ARE CONTRIBUTING TO MLCAPES OF 500-1000 J/KG. GJT VWP INDICATES RELATIVELY STRONG FLOW ABOVE THE BOUNDARY LAYER /I.E. 35 KT WLY WINDS AT 2 KM AGL INCREASING TO 60 KTS OUT OF THE SW AT 6 KM AGL/ WITH VERTICAL SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1891. ..MEAD.. 08/26/2006  From swody1 at goshenarc.org Sun Aug 27 01:02:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 21:02:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270102 SWODY1 SPC AC 270100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SAT AUG 26 2006 VALID 270100Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL AND SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE OH VALLEY AND GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTION OF SERN CO... ...NWRN TX THROUGH CNTRL OK AND SERN KS... NUMEROUS STORMS CONTINUE DEVELOPING IN VICINITY OF COLD FRONT AND CONVECTIVE OUTFLOW BOUNDARIES FROM NWRN TX NEWD THROUGH OK INTO SERN KS. THE 00Z RAOB FROM NORMAN SHOWS THE ATMOSPHERE REMAINS MODERATELY UNSTABLE IN THIS REGION...AND BOUNDARY LAYER TEMPERATURE/DEWPOINT SPREADS ARE FAVORABLE FOR ISOLATED DAMAGING WIND GUSTS. SOME HAIL MAY ALSO ACCOMPANY THE STRONGER STORMS. ACTIVITY IS MOSTLY MULTICELL IN CHARACTER. HOWEVER...AN ELEVATED LEFT MOVING SUPERCELL WAS OBSERVED MOVING THROUGH NRN OK N OF THE FRONT DURING THE PAST HOUR WHERE SLIGHTLY STRONGER MID LEVEL FLOW IS CONTRIBUTING TO BULK EFFECTIVE SHEAR AROUND 35 KT. AS THE BOUNDARY LAYER DECOUPLES TONIGHT...WARM SECTOR LOW LEVEL FLOW IS FORECAST TO INCREASE TO SLY AT 20-25 KT. THIS SHOULD ENHANCE LIFT AND SUPPORT CONTINUED DEVELOPMENT ALONG AND N OF THE FRONT/OUTFLOW BOUNDARY. THIS SEVERE THREAT MAY PERSIST FOR ANOTHER FEW HOURS. ...GREAT LAKES...OH VALLEY THROUGH MID ATLANTIC... SCATTERED STORMS CONTINUE DEVELOPING WITHIN ZONE OF ASCENT ACCOMPANYING SHORTWAVE TROUGH MOVING EWD THROUGH ERN IL INTO IND. LATEST VWP DATA SHOW THE SLY LOW LEVEL JET HAS INCREASED TO 40 KT IN ADVANCE OF THIS FEATURE WITH FAVORABLE LOW LEVEL HODOGRAPHS FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES. UPDRAFT ROTATION HAS RECENTLY BEEN OBSERVED IN A FEW OF THE STORMS. THREAT WILL EXIST FOR AN ISOLATED BRIEF TORNADO OR TWO WITH ANY SUSTAINED SUPERCELL NEXT FEW HOURS. PRIMARY LIMITING FACTOR IS MARGINAL INSTABILITY AND POOR LAPSE RATES. OTHER STORMS ARE DEVELOPING ACROSS SRN MI. THIS ACTIVITY MAY REMAIN CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS NEXT COUPLE HOURS. ...CO... STORMS MOVING THROUGH ERN CO MAY REMAIN CAPABLE OF PRODUCING ISOLATED DAMAGING WIND AND LARGE HAIL NEXT COUPLE HOURS. HOWEVER...THIS ACTIVITY IS EXPECTED TO BEGIN A WEAKENING TREND AS IT APPROACHES THE KS BORDER WHERE INSTABILITY IS MORE LIMITED. ..DIAL.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 05:52:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 01:52:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270553 SWODY1 SPC AC 270551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT SUN AUG 27 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL AND SRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN PARTS OF THE UPPER OH VALLEY INTO THE MID ATLANTIC AND NERN U.S.... ...SYNOPSIS... UPPER PATTERN WILL REMAIN PROGRESSIVE THIS PERIOD. UPPER LOW OVER CO WILL CONTINUE EWD INTO THE CNTRL AND SRN PLAINS. FARTHER EAST...A VORT MAX NOW OVER IND WILL MOVE EWD INTO PA AND THE NERN U.S. DURING THE AFTERNOON. AT THE SURFACE A COLD FRONT WILL ACCOMPANY THE VORT MAX INTO THE MID ATLANTIC AND NERN U.S. DURING THE AFTERNOON. TRAILING PORTION OF THIS BOUNDARY WILL EXTEND SWWD INTO THE LOWER MS VALLEY AND SRN PLAINS. A WARM FRONT CURRENTLY FROM NRN VA INTO SWRN PA MAY LIFT SLOWLY NWD DURING THE DAY. ...CNTRL AND SRN HIGH PLAINS... WEAK ENELY BOUNDARY LAYER FLOW IN POST FRONTAL ENVIRONMENT SHOULD MAINTAIN LOW LEVEL DEWPOINTS IN THE UPPER 50S TO NEAR 60 INTO THE CNTRL AND SRN HIGH PLAINS. MID LEVEL DRY SLOT WILL ADVECT NEWD THROUGH ERN CO IN WAKE OF VORT MAX NOW OVER ERN CO. SECONDARY VORT MAX WILL ROTATE THROUGH THE BASE OF THE EWD ADVANCING UPPER LOW AND INTO PARTS OF THE CNTRL HIGH PLAINS DURING THE DAY. SURFACE HEATING WITHIN DRY SLOT AND COOLING MID LEVEL TEMPERATURES ACCOMPANYING THE UPPER LOW WILL RESULT IN STEEP LAPSE RATES DURING THE AFTERNOON. THE STEEP LAPSE RATES AND IN SITU LOW LEVEL MOISTURE WILL RESULT IN MODERATE INSTABILITY WITH MLCAPE AROUND 1500 J/KG. STORMS ARE EXPECTED TO DEVELOP WITHIN ZONE OF LARGE SCALE ASCENT ACCOMPANYING THE SHORTWAVE TROUGH AS THE BOUNDARY LAYER DESTABILIZES DURING THE AFTERNOON. LOW LEVEL WIND FIELDS WILL REMAIN RATHER WEAK. HOWEVER...A 40 KT MID LEVEL JET ROTATING THROUGH BASE OF UPPER TROUGH WILL CONTRIBUTE TO FAVORABLE DEEP SHEAR FOR SUPERCELL STRUCTURES. LARGE HAIL AND DAMAGING WIND WILL BE THE MAIN THREATS. ...SRN PORTIONS OF THE UPPER OH VALLEY THROUGH PORTIONS OF THE MID ATLANTIC AND NERN STATES... CORRIDOR OF LOW LEVEL DEWPOINTS IN THE UPPER 60S TO NEAR 70 SHOULD PERSIST IN VICINITY OF WARM FRONT AS IT RETREATS SLOWLY NWD. THIS BOUNDARY SHOULD EXTEND FROM NJ WNWWD THROUGH PA SUNDAY AFTERNOON. PRIMARY CONCERN AND POTENTIAL OVERALL LIMITING FACTOR WILL BE DEGREE OF DESTABILIZATION. THUNDERSTORMS WILL LIKELY CONTINUE DEVELOPING INTO EARLY SUNDAY WITHIN ZONE OF ASCENT ACCOMPANYING A VORT MAX CURRENTLY OVER NRN IND. THIS FEATURE SHOULD APPROACH WRN PA BY SUNRISE. OTHER STORMS MAY CONTINUE INTO PARTS OF PA WITHIN ZONE OF WARM ADVECTION N OF THE WARM FRONT. CLOUDS SHOULD REMAIN MORE WIDESPREAD N OF THE FRONT FROM PARTS OF OH AND PA NWD INTO THE NERN STATES. BEST POTENTIAL FOR DESTABILIZATION WILL EXIST NEAR AND S OF THIS BOUNDARY. HOWEVER...WEAK MID LEVEL LAPSE RATES SHOULD LIMIT MLCAPE TO AOB 1000 J/KG. STORMS MAY INTENSIFY ALONG AND N OF WARM FRONT AS WARM SECTOR SOURCE REGION DESTABILIZES. SRN BRANCH OF LOW LEVEL JET IS FORECAST TO STRENGTHEN FROM THE MID ATLANTIC INTO THE NERN STATES IN ASSOCIATION WITH APPROACHING SHORTWAVE TROUGH. THIS WILL RESULT IN LOW LEVEL HODOGRAPHS FAVORABLE FOR A THREAT OF SUPERCELLS WITH LOW LEVEL MESOCYCLONES AND ISOLATED TORNADOES NEAR WARM FRONT. OTHERWISE...THREAT OF ISOLATED DAMAGING WIND WILL EXIST AS STORMS DEVELOP EWD ALONG AND AHEAD OF COLD FRONT. ...NERN TX AND SERN OK THROUGH PORTIONS OF THE LOWER AND MIDDLE MS VALLEY... STORMS ARE EXPECTED TO REDEVELOP DURING THE AFTERNOON ALONG FRONT OR RESIDUAL CONVECTIVE OUTFLOW BOUNDARIES. THE ATMOSPHERE WILL LIKELY ONCE AGAIN BECOME MODERATELY UNSTABLE IN VICINITY OF THESE BOUNDARIES WHERE SURFACE HEATING CAN DEVELOP OUTSIDE OF CONVECTIVE DEBRIS. MODEST VERTICAL SHEAR WILL SUPPORT MAINLY MULTICELLS WITH A THREAT OF ISOLATED DAMAGING WIND. MCV CURRENTLY MOVING ENEWD THROUGH CNTRL OK MAY RESULT IN A GREATER CONCENTRATION OF STORMS OVER PARTS OF AR OR SRN MO DURING THE DAY. AN UPGRADE TO SLIGHT RISK MIGHT BE NEEDED FOR PARTS OF THIS AREA IN LATER OUTLOOKS IF IT BECOMES MORE CERTAIN THAT ONGOING STORMS WILL NOT EXHAUST THE INSTABILITY IN THIS REGION. ..DIAL/TAYLOR.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 12:32:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 08:32:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271232 SWODY1 SPC AC 271230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0730 AM CDT SUN AUG 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS SE PA/MD/DE/NJ... ...HIGH PLAINS THIS AFTERNOON... A COLD CORE MID LEVEL LOW OVER NW CO WILL PROGRESS EWD TO NE CO BY THIS AFTERNOON...AND CONTINUE ACROSS NEB/KS INTO TONIGHT. A BAND OF THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON ACROSS ERN CO/NE NM AND SPREAD ESEWD INTO WRN KS AND THE TX PANHANDLE IN ASSOCIATION WITH THIS MID LEVEL WAVE. THOUGH MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP OVER THE HIGH PLAINS...SUFFICIENT INSTABILITY FOR STRONG/SEVERE STORMS IS EXPECTED BY EARLY AFTERNOON. RESIDUAL BOUNDARY LAYER DEWPOINTS OF 55-60 F FROM NE NM/NW TX PANHANDLE INTO ERN CO/WRN KS AND SURFACE HEATING IN THE WAKE OF A CONVECTIVE BAND THIS MORNING SHOULD SUPPORT MLCAPE VALUES OF 500-1000 J/KG. DEEP LAYER WIND FIELDS AND VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...THE STRONGEST OF WHICH WILL BE CAPABLE OF PRODUCING AT LEAST MARGINALLY SEVERE HAIL AND STRONG OUTFLOW WINDS. ...SE PA/NJ AREA TODAY... REMNANT MCV IS MOVING EWD OVER CENTRAL OH THIS MORNING...AND SHOULD CONTINUE ACROSS PA THIS AFTERNOON WHILE INTERACTING WITH A WARM FRONT THAT SHOULD LIFT SLOWLY NWD ACROSS PA/NJ. THE DEGREE OF INSTABILITY ALONG THE BOUNDARY IS IN QUESTION GIVEN THE ONGOING CONVECTION AND RATHER THICK CLOUD COVER FROM SE PA INTO OH. HOWEVER...LOW-LEVEL MOISTURE WILL BE SUFFICIENT FOR EMBEDDED THUNDERSTORMS IN THE ABSENCE OF STRONG SURFACE HEATING. OBSERVED AND FORECAST HODOGRAPHS APPEAR FAVORABLE FOR SUPERCELLS INVOF THE WARM FRONT TODAY...WHERE A FEW STORMS COULD PRODUCE DAMAGING WINDS AND PERHAPS A TORNADO OR TWO. ...OK/AR/MO TODAY... A SURFACE FRONT NEAR I-44 IN MO/OK WILL MOVE LITTLE THIS PERIOD...WITH WEAK WAVE DEVELOPMENT ANTICIPATED ALONG THE FRONT FROM CENTRAL/NE OK INTO SE KS IN ADVANCE OF THE APPROACHING MID LEVEL TROUGH FROM CO. WIDESPREAD CONVECTION FROM SATURDAY EVENING INTO THIS MORNING PRODUCED CONVECTIVE OUTFLOWS THAT NOW EXTEND FROM CENTRAL TX ACROSS SE OK/NW AR INTO SRN MO...AS WELL AS AN MCV THAT IS PROGRESSING NEWD OVER NE OK. THOUGH THE OUTFLOW BOUNDARIES SHOULD BECOME MORE DIFFUSE ACROSS OK/AR/MO AS CONVECTION DIMINISHES THIS MORNING...THE MCV MAY PERSIST AND FOCUS ADDITIONAL THUNDERSTORM DEVELOPMENT DURING THE DAY ACROSS NE OK/SRN MO/NW AR. GRADUAL MOISTENING OF THE LOW-MID LEVELS SUGGEST THAT SURFACE TEMPERATURES AND LOW-LEVEL LAPSE RATES WILL NOT BE AS GREAT AS OBSERVED THE PAST TWO DAYS ACROSS THE OK AREA...THUS THE POTENTIAL FOR DAMAGING DOWNBURSTS SHOULD BECOME RATHER MARGINAL. ..THOMPSON/TAYLOR.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 16:40:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 12:40:18 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271640 SWODY1 SPC AC 271638 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1138 AM CDT SUN AUG 27 2006 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF THE DELMARVA.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING ACROSS PARTS OF THE LOWER OHIO VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY TONIGHT ACROSS THE CENTRAL HIGH PLAINS.... ...SYNOPSIS... MID/UPPER LEVEL LOW OVER THE CENTRAL ROCKIES WILL MOVE INTO NEB DURING THE PERIOD. TROUGH ASSOCIATED WITH THIS LOW WILL DRAG EWD THRU THE CENTRAL AND NRN PARTS OF THE SRN PLAINS. LATEST SURFACE ANALYSIS SHOWS A SERIES OF CONVECTIVE BOUNDARIES THAT REACH FROM CENTRAL IND WSWWD ACROSS SRN MO INTO NERN AND S CENTRAL OK INTO W CENTRAL TX. IN ADDITION...THERE IS A QUASI STATIONARY FRONT THAT LIES FROM SRN NJ WWD ACROSS THE MD/WV PANHANDLE INTO CENTRAL OH. LOOKS AT THIS TIME THAT THE STRONGEST ACTIVITY TODAY AND EARLY TONIGHT WILL FOCUS ON THESE AREAS WHERE THERMAL GRADIENTS WILL PROVIDE THE MORE FAVORABLE THERMODYNAMICS FOR STRONG/ISOLATED SEVERE THUNDERSTORMS. ...PARTS OF THE DELMARVA REGION FROM SRN PA/MD AND NRN VA INTO DE... LATEST VISIBLE IMAGERY SHOWS SRN EDGES OF CLOUD COVER FROM DE/MD INTO NRN VA THEN SWWD ACROSS SERN WV. AREAS S OF THIS CLOUD COVER DELINEATION WILL BE LOCATION OF BETTER DAYTIME HEATING/ THERMODYNAMICS. ISOLATED STRONG/SEVERE THUNDERSTORMS ARE POSSIBLE AS THERE WILL BE FAVORABLE SHEAR /STORM RELATIVE HELICITY AROUND 200 M2/S2/ DUE TO LOW LEVEL WARM ADVECTION. LOOKS LIKE STRONG GUSTY WINDS MAY BE THE MAIN THREAT LATER THIS AFTERNOON INTO THIS EVENING. ...PARTS OF THE LOWER OHIO VALLEY... REMNANT OF COLD FRONTAL BOUNDARY EXTENDS FROM LOW OVER SERN ONTARIO SWWD THRU SWRN IND INTO CENTRAL KS. CONSIDERABLE CLOUDINESS COVERS MUCH OF THESE REGION FROM PREVIOUS CONVECTION. THUS...ONCE AGAIN WILL LOOK FOR WHERE THERMAL GRADIENTS MAY SET UP THE BEST FOR AFTN/EVE THUNDERSTORM DEVELOPMENT. BOTH THE NAM AND GFS DEVELOPS CONVECTION ALONG THE SRN FRINGES OF THE CLOUD COVER FROM THE CENTRAL MO/AR BORDER ENEWD INTO N CENTRAL KY. SBCAPE IS FORECAST TO BE BETWEEN 2000-3000 J/KG BY LATER TODAY. THUS...STRONG/ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THESE AREA WITH THE THREAT BEING STRONG GUSTY WINDS AND SOME HAIL. ...CENTRAL HI PLAINS... MID/UPPER LEVEL LOW WILL BE MOVING OUT OF THE CENTRAL ROCKIES BY MID AFTN. WHILE THE AIR MASS LOOKS WORKED OVER ACROSS THE CENTRAL PLAINS FROM CONVECTION OVER THE PAST FEW DAYS...BEST THERMAL GRADIENT EXTENDS FROM SWRN/CENTRAL TX NEWD INTO SERN OK. MID LEVEL COOLING IS EXPECTED TO MOVE ACROSS ERN CO BY MID AFTN AND THIS SHOULD AID IN INITIATING CONVECTIVE DEVELOPMENT WITH DAYTIME HEATING ALONG THE WRN EDGES OF THE EXISTING CLOUD COVER OVER ERN CO. DAYTIME HEATING WITH UPSLOPE COMPONENT TO THE FLOW SHOULD BE SUFFICIENT IN DEVELOPING STRONG/POSSIBLE SEVERE THUNDERSTORMS ACROSS ERN CO THIS AFTN WITH SBCAPE BETWEEN 1000-1500 J/KG. MAIN THREAT AGAIN WILL BE HAIL AND DAMAGING WINDS. MID/UPPER LEVEL FLOW IS EXPECTED TO BE SUFFICIENT FOR DEEP LAYER SHEAR TO 40 KT WHICH WILL BE ENOUGH TO SUPPORT UPDRAFTS/ISOLATED SUPERCELLS. ..MCCARTHY/GRAMS.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 19:48:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 15:48:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271948 SWODY1 SPC AC 271947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SUN AUG 27 2006 VALID 272000Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY TO THE MIDDLE ATLANTIC COAST... ...CNTRL/SRN HIGH PLAINS... DAYTIME HEATING COUPLED WITH HEIGHT FALLS/DYNAMIC COOLING ASSOCIATED WITH THE APPROACH OF UPPER LOW THROUGH THE CNTRL ROCKIES ARE CONTRIBUTING TO AIR MASS DESTABILIZATION THIS AFTERNOON ACROSS ERN CO INTO WRN KS AND SWD INTO THE OK/TX PNHDLS AND NERN NM. CONTINUED HEATING SHOULD SUPPORT FURTHER DESTABILIZATION THIS AFTERNOON WITH MLCAPES APPROACHING 1000-1500 J/KG. WHILE MORNING RAOB DATA INDICATED 25-30 KT FLOW AT 500 MB ACROSS CO...UPPER TROPOSPHERIC WIND FIELDS WERE STRONGER /55-65 KTS/...WHICH WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS AS EFFECTIVE BULK SHEARS STRENGTHEN TO 45-55 KTS. VISIBLE SATELLITE AND REGIONAL RADAR IMAGERY SHOW EARLY STORM DEVELOPMENT FROM NERN CO/SWRN NEB/NWRN KS SSWWD TOWARD THE RATON MESA. INCREASING FORCING FOR UPWARD VERTICAL MOTION AND DECREASING STATIC STABILITY SHOULD SUPPORT INCREASING STORM COVERAGE ACROSS THE REGION THIS AFTERNOON INTO EVENING WITH THE POTENTIAL FOR A FEW SUPERCELLS CAPABLE OF MAINLY LARGE HAIL AND LOCALLY STRONG WIND GUSTS. STORMS MAY MERGE INTO CLUSTERS THIS EVENING WITH SOME DAMAGING WIND THREAT OVER WRN KS INTO THE PNHDLS. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1902. ...MID MS/LOWER OH VALLEYS EWD ALONG THE OH RIVER... CLUSTERS OF TSTMS CONTINUE THIS AFTERNOON FROM NE OF EVV SWWD ACROSS SRN MO/NRN AR WITHIN A MOIST LOW-LEVEL AIR MASS WHERE MLCAPES HAVE INCREASED TO 2000 J/KG. LONG LOOP RADAR IMAGERY SUGGESTS THE PRESENCE OF AN MCV OVER SWRN MO WHICH WILL CONTINUE EWD THIS AFTERNOON AND EVENING...LIKELY ENHANCING DOWNSTREAM CONVECTIVE DEVELOPMENT ALONG AND S OF LOW-LEVEL BAROCLINIC ZONE. AREA PROFILERS/VWPS INDICATE THAT VERTICAL SHEAR REMAINS RELATIVELY WEAK THOUGH THERE IS SOME LOW-LEVEL VEERING WITH HEIGHT IN THE LOWEST 3-4 KM AGL. GIVEN THIS TYPE OF ENVIRONMENT...EXPECT THE PRIMARY CONVECTIVE MODE TO REMAIN MULTICELLULAR CLUSTERS CAPABLE OF DAMAGING WINDS...ESPECIALLY IF STORMS CAN ORGANIZE A COLD POOL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1901. ...MID ATLANTIC COAST... A SOMEWHAT MORE CONDITIONAL THREAT OF SEVERE STORMS INCLUDING SUPERCELLS EXISTS ACROSS THE REGION THIS AFTERNOON INTO EVENING INVOF OF WARM OR QUASI-STATIONARY BOUNDARY EXTENDING FROM WEAK SURFACE LOW OVER NERN OH SEWD THROUGH W-CNTRL PA TO CNTRL NJ. PRIMARY CLOUD BAND ASSOCIATED WITH BELT OF FORCING FOR ASCENT ATTENDANT TO SHORT WAVE TROUGH MOVING THROUGH WRN PA IS CURRENTLY SPREADING E OF THE HIGHER TERRAIN INTO CNTRL PARTS OF MD/VA. HOWEVER...AIR MASS S OF BOUNDARY HAS WARMED INTO THE UPPER 80S AND LOWER 90S WHICH IS RESULTING IN MLCAPES OF 500-1000 J/KG. STORMS CURRENTLY DEVELOPING OVER FAR WRN PA/WV WILL LIKELY CONTINUE TO SPREAD EWD/SEWD LATE THIS AFTERNOON INTO EVENING WITH AN INHERENT SEVERE THREAT INCREASING ACROSS SRN PA INTO MD/NRN VA AND DE. RELATIVELY STRONG VEERING IN THE LOW-LEVELS AND THE PRESENCE OF 30-35 KT WLY MID-LEVEL FLOW IS RESULTING IN SHEAR PROFILES SUPPORTIVE OF SUPERCELLS CAPABLE OF DAMAGING WINDS AND PERHAPS A BRIEF TORNADO. ..MEAD.. 08/27/2006  From swody1 at goshenarc.org Mon Aug 28 00:56:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 20:56:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280056 SWODY1 SPC AC 280054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0754 PM CDT SUN AUG 27 2006 VALID 280100Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SERN CO/SWRN KS/NERN NM/THE TX AND OH PANHANDLES... ...CENTRAL AND SRN HIGH PLAINS... UPPER TROUGH CONTINUES MOVING SEWD INTO THE PLAINS...WITH LARGE-SCALE ASCENT ACROSS THE CENTRAL AND SRN HIGH PLAINS SUPPORTING STORMS FROM NWRN KS SWD ACROSS THE SRN HIGH PLAINS. STRONGEST SHEAR IS INDICATED FROM KS/CO SWD INTO THE TX PNHDL/NERN NM...WHERE PRIMARY SEVERE THREAT EXISTS THIS EVENING. WITH 1000 TO 1500 J/KG MEAN-LAYER CAPE AND KINEMATIC ENVIRONMENT CHARACTERIZED BY WEAK LOW-LEVEL FLOW BUT DEEP-LAYER SHEAR SUFFICIENT FOR ORGANIZED/ROTATING STORMS...EXPECT HAIL AND LOCALLY STRONG/GUSTY WINDS TO BE THE MAIN SEVERE THREATS WITH STRONGEST CELLS THROUGH MID TO LATE EVENING. MEANWHILE...INCREASING INSTABILITY SWD INTO THE TRANSPECOS REGION WILL SUPPORT A MORE ISOLATED SEVERE THREAT ACROSS THIS REGION -- WITH DEVELOPING SELY LOW-LEVEL JET SUPPORTING WIDESPREAD CONVECTION THROUGH THE REMAINDER OF THE PERIOD. ...OH VALLEY WWD INTO THE OZARKS/ARKLATEX... LIMITED SHEAR BUT SUFFICIENT INSTABILITY EXISTS ACROSS THE OH VALLEY REGION AND SWWD INTO THE OZARKS/ARKLATEX...WHERE WIDESPREAD THUNDERSTORMS ARE ONGOING. THOUGH OVERALL SEVERE THREAT SHOULD DIMINISH SLOWLY WITH TIME...LOCALLY STRONG/GUSTY WINDS OR MARGINALLY-SEVERE HAIL WILL BE POSSIBLE WITH STRONGEST STORMS -- MAINLY PRIOR TO MIDNIGHT. ..GOSS.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 06:01:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 02:01:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280601 SWODY1 SPC AC 280559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT MON AUG 28 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH OVER THE CENTRAL CONUS WILL MOVE SLOWLY EWD THIS PERIOD...AS A SECOND/STRONGER FEATURE MOVES SEWD INTO THE PAC NW. WIND FIELD ALOFT ACROSS THE CENTRAL AND ERN CONUS WILL REMAIN GENERALLY WEAK...THOUGH BELT OF SLIGHTLY ENHANCED /30 TO 35 KT/ WSWLY FLOW SHOULD EXTEND FROM THE CENTRAL PLAINS ENEWD ACROSS THE OH VALLEY AROUND SRN SIDE OF UPPER TROUGH. AT THE SURFACE...BAROCLINIC ZONE EXTENDING FROM THE MID-ATLANTIC REGION WWD ACROSS THE OH ALLEY AND THEN SWWD ACROSS THE OZARKS INTO CENTRAL TX SHOULD MOVE LITTLE THIS PERIOD...AS LOW/FRONTAL WAVE MOVES EWD ACROSS THE OH VALLEY. THIS FRONT WILL BE A FOCUS FOR CONVECTIVE ACTIVITY...THOUGH COMBINATION OF INSTABILITY AND SHEAR SHOULD REMAIN ONLY MARGINALLY-SUPPORTIVE OF SEVERE STORMS THROUGH THE PERIOD. ...OH VALLEY REGION... STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF THE MIDDLE OH VALLEY...WHICH SHOULD CONTRIBUTE TO WEAK LAPSE RATES AND WIDESPREAD CLOUDINESS ALONG THE FRONTAL ZONE. NONETHELESS...STORMS SHOULD INCREASE IN COVERAGE THROUGH THE AFTERNOON FROM THE MID-ATLANTIC REGION WWD TO THE MID MS VALLEY...AS POCKETS OF DESTABILIZATION DEVELOP. NAM SUGGESTS THAT A WEAK MID-LEVEL FEATURE -- DIFFICULT TO DISCERN IN WV IMAGERY ATTM -- WILL MOVE EWD ACROSS THIS REGION DURING THE AFTERNOON AHEAD OF MAIN TROUGH. THOUGH AREA WILL NOT BE UPGRADED TO SLIGHT RISK ATTM DUE TO QUESTIONS REGARDING DEGREE OF INSTABILITY...A SLIGHTLY MORE CONCENTRATED SEVERE THREAT MAY EVOLVE ACROSS THIS REGION DURING THE AFTERNOON. ...OZARKS SWWD INTO CENTRAL TX AND THEN NWWD INTO NM... THOUGH STRONGER DAYTIME HEATING IS ANTICIPATED ACROSS THIS REGION DURING THE AFTERNOON...WEAK LAPSE RATES ARE ANTICIPATED AS WIDESPREAD PRECIPITATION CONTINUES. DESTABILIZATION SHOULD BE SUFFICIENT...HOWEVER...FOR FAIRLY WIDESPREAD CONVECTIVE DEVELOPMENT -- BOTH ALONG FRONT ACROSS AR AND TX...AND IN POST-FRONTAL UPSLOPE REGIME INTO NM. DESPITE WIDESPREAD STORM DEVELOPMENT...STRONGER FLOW ALOFT SHOULD REMAIN WELL N OF THIS REGION. THEREFORE...EXPECT PULSE AND MULTICELL STORM MODES TO PREVAIL -- THUS LIMITING SEVERE POTENTIAL. THOUGH A MARGINAL SEVERE THREAT WILL EXIST...SITUATION DOES NOT WARRANT A SLIGHT RISK UPGRADE ATTM. ..GOSS.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 12:23:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 08:23:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281223 SWODY1 SPC AC 281221 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0721 AM CDT MON AUG 28 2006 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A MID LEVEL TROUGH OVER THE CENTRAL PLAINS WILL PROGRESS SLOWLY EWD TOWARD THE MID MS VALLEY BY EARLY TUESDAY. AS THIS OCCURS...A BROAD/WEAK SURFACE LOW ACROSS NRN MO WILL CONSOLIDATE AND DEVELOP EWD ACROSS THE OH VALLEY...ALONG A PRE-EXISTING E-W BAROCLINIC ZONE. IN THE WAKE OF THE SURFACE CYCLONE...A COLD FRONT WILL MOVE SEWD ACROSS OK/N TX/NW AR AND MO. THIS BAROCLINIC ZONE...ALONG WITH PRE-FRONTAL OUTFLOW BOUNDARIES AND DIFFERENTIAL HEATING ALONG THE EDGE OF THE THICKER CLOUDS...WILL SERVE AS THE PRIMARY FOCUS FOR THUNDERSTORM DEVELOPMENT THROUGH TONIGHT. ...OH VALLEY... A BROAD SWATH OF RICH LOW-MID LEVEL MOISTURE /PW VALUES OF 1.75-2.25 INCHES AND BOUNDARY LAYER DEWPOINTS AOA 70 F/ IS PRESENT FROM THE SRN PLAINS TO THE OH VALLEY AND NRN MID ATLANTIC REGION. WIDESPREAD PRECIPITATION THE PAST TWO DAYS WITHIN THIS SWATH HAS REDUCED LOW-MID LEVEL LAPSE RATES TO ROUGHLY MOIST ADIABATIC...WHICH WILL LIMIT POTENTIAL INSTABILITY ALONG THE FRONT AND IN ADVANCE OF THE SURFACE LOW. ALSO...VERTICAL SHEAR WILL REMAIN WEAK IN THE MAJORITY OF THE WARM SECTOR. RELATIVELY STRONGER LOW-LEVEL AND DEEP LAYER SHEAR WILL BE CONFINED TO A NARROW CORRIDOR IMMEDIATELY E OF THE SURFACE LOW ACROSS THE OH VALLEY...WHERE FORECAST SOUNDINGS/HODOGRAPHS SUGGEST SOME POTENTIAL FOR SUPERCELLS. AN ISOLATED TORNADO CANNOT BE RULED OUT...ALONG WITH STRONG WIND GUSTS...BUT THE WEAK INSTABILITY/MOIST PROFILES SUGGEST THAT ANY SEVERE STORM THREAT SHOULD BE REMAIN MARGINAL. ..THOMPSON/CROSBIE.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 16:31:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 12:31:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281631 SWODY1 SPC AC 281630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT MON AUG 28 2006 VALID 281630Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SEASONABLY STRONG SHORTWAVE TROUGH OVER ERN NEB EXPECTED DEAMPLIFY SLIGHTLY AS IT MOVES E INTO ERN IA BY 12Z TUESDAY. AT THE SURFACE...WEAK WAVE NOW IN CNTRL IL SHOULD DRIFT E ALONG STALLED FRONT EXTENDING E INTO SRN OH. IN WAKE OF THE LOW...COLD FRONT SHOULD SETTLE SLOWLY SE ACROSS PARTS OF TX/OK/AR AND LWR TN/OH VLYS. ...OH VLY/CNTRL APLCNS... VERY MOIST /PWS AOA 2 INCHES/...WEAKLY UNSTABLE AIR WILL PREVAIL FROM THE LWR OH VLY NEWD INTO FAR WRN PA/WV TODAY...WHERE MODEST SURFACE HEATING WILL CONTINUE ALONG AND S OF STALLED SURFACE FRONT. AREA VWPS...MORNING SOUNDINGS AND LATEST MODEL FORECASTS SUGGEST THAT A BAND OF 30+ KT WSWLY MID LEVEL FLOW WILL PERSIST/SPREAD NEWD UP THE OH VLY ON SERN FRINGE OF NEB/IA SHORTWAVE IMPULSE. PRESENCE OF THIS WEAK JET STREAK WILL YIELD MODERATE...UNIDIRECTIONAL CLOUD LAYER WIND PROFILES WITH ANY STORMS FORMING IN WARM SECTOR. COUPLED WITH HI PWS...SETUP MAY PROMOTE DEVELOPMENT OF A FEW SMALL SCALE BOWING SEGMENTS WITH LOCALLY DAMAGING WIND ACROSS KY/SRN WV. A BIT FARTHER N...WEAK BUT BACKED LOW LEVEL FLOW WILL ENLARGE LOW LEVEL HODOGRAPH CURVATURE INVOF STATIONARY FRONT FROM CNTRL/SRN IND ENE INTO CNTRL/SRN OH...WRN WV AND NRN KY. STORMS LIKELY TO FORM IN AREA OF ENHANCED CONVERGENCE IMMEDIATELY DOWNSTREAM FROM IL/IND SURFACE WAVE MAY DEVELOP WEAK LOW LEVEL MESOCYCLONES AND YIELD A TORNADO OR TWO LATER THIS AFTERNOON THROUGH EARLY TONIGHT. BUT LIMITED DEGREE OF INSTABILITY SHOULD KEEP SUCH ANY ACTIVITY BRIEF/ ISOLATED. ..CORFIDI/GRAMS.. 08/28/2006  From swody1 at goshenarc.org Wed Aug 30 06:07:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 02:07:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300602 SWODY1 SPC AC 300600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT WED AUG 30 2006 VALID 301200Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN IS FORECAST TO BECOME MORE HIGHLY-AMPLIFIED THROUGH THE PERIOD. SEASONABLY STRONG UPPER TROUGH WILL CONTINUE MOVING EWD ACROSS THE NWRN CONUS. THIS TROUGH WILL IMPINGE ON A SECOND TROUGH OVER THE MIDWEST...WHOSE EWD PROGRESS WILL BE HINDERED BY ERNESTO MOVING NWD ACROSS FL AND INTO THE SWRN ATLANTIC. THOUGH A COLD FRONT WILL MOVE ACROSS MT/WY AND APPROACH THE NRN PLAINS DURING THE SECOND HALF OF THE PERIOD...CONVECTIVE THREAT SHOULD BE LIMITED BY DRY/CAPPED BOUNDARY LAYER. ELSEWHERE...WEAK BAROCLINIC ZONE WILL LINGER FROM THE CAROLINAS INTO GA/AL...BUT WEAK LAPSE RATES ASSOCIATED WITH ONGOING PRECIPITATION WITHIN TROPICAL AIRMASS SPREADING NWD SHOULD LIMIT POTENTIAL FOR DESTABILIZATION AND THUS SEVERE POTENTIAL. ...ERN FL PENINSULA... RELATIVELY STRONG/WEAKLY-VEERING FLOW IN THE LOWER TROPOSPHERE WITHIN THE NERN QUADRANT OF ERNESTO WILL REMAIN ACROSS THE ERN HALF OF THE FL PENINSULA THROUGH THE FIRST HALF OF THE PERIOD. GIVEN VERY MOIST BOUNDARY LAYER...SHEAR MAY SUPPORT LOW-LEVEL ROTATION WITHIN STRONGER CONVECTIVE CELLS -- AND PERHAPS AN ISOLATED/BRIEF TORNADO. THREAT SHOULD DIMINISH OVERNIGHT AS ERNESTO MOVES OFF THE E CENTRAL FL COAST. ...THE CAROLINAS... WIDESPREAD PRECIPITATION WILL LIKELY BE ONGOING ACROSS THE CAROLINAS AT THE START OF THE PERIOD...AND SHOULD CONTINUE WITHIN TROPICAL AIRMASS SPREADING NWD AHEAD OF ERNESTO. WEAK LAPSE RATES WILL LIMIT DESTABILIZATION...BUT SLIGHTLY-ENHANCED BELT OF WSWLY MID-LEVEL FLOW ON SERN PERIPHERY OF UPPER TROUGH MAY SUPPORT A FEW ORGANIZED STORMS...AND ASSOCIATED POTENTIAL FOR ISOLATED STRONG/GUSTY WINDS. ..GOSS.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 12:38:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 08:38:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301239 SWODY1 SPC AC 301236 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 AM CDT WED AUG 30 2006 VALID 301300Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...E CENTRAL FL TODAY... TROPICAL STORM ERNESTO IS DRIFTING NWD OVER S FL THIS MORNING...AND IS FORECAST TO EMERGE OFF THE E CENTRAL FL COAST BY EARLY TONIGHT /SEE LATEST NHC ADVISORIES FOR ADDITIONAL INFORMATION/. LOCAL VWP/S SHOW A NARROW CORRIDOR OF SOMEWHAT ENHANCED VERTICAL SHEAR COLOCATED WITH A BROKEN OUTER CONVECTIVE BAND BETWEEN PBI AND MLB. THIS BAND SHOULD SHIFT NWD INTO THE MLB-DAB AREAS DURING THE DAY...WHERE AN ISOLATED/BRIEF TORNADO COULD OCCUR. HOWEVER...THE RATHER POOR CONVECTIVE STRUCTURE OF THE STORM AND MODEST WIND FIELDS SUGGEST THAT ANY TORNADO THREAT SHOULD REMAIN MARGINAL. ...SE STATES TODAY... A MID LEVEL TROUGH ALONG AN AXIS FROM NW AR TO NRN IL THIS MORNING WILL DRIFT ESEWD OVER THE OH/MS VALLEYS THROUGH TONIGHT. AT THE SURFACE...A COLD FRONT WILL SAG SWD ACROSS VA TOWARD NC AS SURFACE PRESSURE RISE ACROSS NEW ENGLAND IN THE WAKE OF A NRN STREAM TROUGH. THE FRONT WILL ALSO MOVE VERY SLOWLY SEWD ACROSS THE LOWER MS VALLEY AND SRN APPALACHIANS. A MOIST/TROPICAL AIR MASS IS IN PLACE E OF THE FRONT...WHICH WILL SUPPORT SCATTERED THUNDERSTORMS THROUGH THE PERIOD ACROSS THE SE STATES. DESPITE MODEST MID LEVEL LAPSE RATES...DAYTIME HEATING WITHIN CLOUD BREAKS COULD ALLOW MLCAPE VALUES TO REACH 1500-2500 J/KG THIS AFTERNOON. VERTICAL SHEAR WILL BE RATHER WEAK IN THE OPEN WARM SECTOR WHERE INSTABILITY SHOULD BE GREATER...WITH RELATIVELY STRONGER SHEAR ALONG THE FRONT IN CLOSER PROXIMITY TO THE BELT OF 25-30 KT MID LEVEL FLOW. THE MODEST SHEAR/INSTABILITY MAY SUPPORT MULTICELL STORMS WITH ISOLATED DAMAGING WINDS TODAY FROM AL TO THE CAROLINAS/SRN VA. ...NRN HIGH PLAINS THIS AFTERNOON/TONIGHT... A DEEP MID LEVEL TROUGH OVER WA/ORE THIS MORNING...AND AN ASSOCIATED COLD FRONT...WILL PROGRESS EWD OVER ID/MT/NW WY BY TONIGHT. MEANWHILE...A LEE CYCLONE WILL DEEPEN ACROSS SE MT DOWNSTREAM FROM THE MID LEVEL WAVE. LOW-LEVEL MOISTURE IS LIMITED ACROSS THE PLAINS IN THE WAKE OF A PRIOR FRONTAL PASSAGE...WITH BOUNDARY LAYER DEWPOINTS RANGING FROM THE MID 40S TO LOWER 50S. A PLUME OF STEEP MID LEVEL LAPSE RATES WILL OVERSPREAD THE MARGINALLY MOIST BOUNDARY LAYER ALONG AND E OF THE LEE TROUGH IN ADVANCE OF THE MID LEVEL WAVE. THE POOR MOISTURE AND SMALL CAPE SUGGEST THAT SURFACE-BASED CONVECTION WILL BE SPARSE AND LIKELY CONFINED TO THE IMMEDIATE LEE CYCLONE/TROUGH WHERE SURFACE TEMPERATURES WARM WELL INTO THE 90S. OTHER ELEVATED STORMS MAY FORM IN A NARROW POST-FRONTAL BAND TONIGHT ACROSS NE MT/NW ND IN CONJUCTION WITH MID LEVEL MOISTENING AND COOLING OF THE COLUMN...THOUGH WEAK INSTABILITY WILL LIMIT THE OVERALL CONVECTIVE THREAT. ..THOMPSON/CROSBIE.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 16:22:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 12:22:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301622 SWODY1 SPC AC 301621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT WED AUG 30 2006 VALID 301630Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MUCH OF THE U.S. IS ENTERING A BLOCKING TYPE PATTERN AS MID/UPPER LEVEL LOW BECOMES ANCHORED OVER IL/IND. MID/UPPER LEVEL TROUGH OVER THE NWRN U.S. WILL MOVE EWD ACROSS THE NRN PLATEAU INTO THE NRN ROCKIES AS MID/UPPER LEVEL RIDGE HAS BEEN PUSHED INTO THE SWRN U.S. AND EXTENDS NEWD INTO THE UPPER MIDWEST. MEANWHILE...T.D. ERNESTO IS FORECAST TO MOVE NNEWD DURING THE PERIOD. SEE LATEST STATEMENTS FROM NHC/TPC ON T.D. ERNESTO. ...E CENTRAL AND NERN FL INTO SERN COASTAL GA... GIVEN THE FORECAST TRACK OF T.D. ERNESTO BY NHC/TPC...OUTER BANDS OF THE STORMS WILL MOSTLY BE EFFECTING COASTAL AREAS FROM MLB NWD TOWARDS SAV. THIS IS WHERE THE FAVORABLE QUADRANT FOR ROTATING UPDRAFTS WILL BE ASSOCIATED WITH ERNESTO DURING THE PERIOD. LOOKS LIKE THE BEST THREAT FOR ISOLATED TORNADOES/WATERSPOUTS WILL BE COASTAL AND MARINE ZONE AREAS OFF THE FL/SERN GA COAST. ...PARTS OF NC AND SC INTO ERN TN... MORNING SURFACE ANALYSIS SHOWS QUASI-STATIONARY BOUNDARY EXTENDING FROM EXTREME SERN VA WSWWD THRU SWRN NC INTO CENTRAL MS. VISIBLE SATELLITE IMAGERY SHOWS AREA OF BEST INSOLATION WILL BE IN THE VICINITY AND S OF THE BOUNDARY WHERE AIR MASS HAS ALREADY DESTABILIZED WITH MLCAPES AROUND 2500 J/KG. THERE IS ALSO THE PRESENCE OF 30-40 KT DEEP LAYER SHEAR EFFECTIVE LOCATED IN FAVORABLE UPPER LEVEL JET ENTRANCE REGION TO ENHANCE UVVS ACROSS THIS AREA THROUGH EARLY TONIGHT. THUS...MULTICELLULAR STORMS ARE EXPECTED THIS AFTERNOON AND EARLY TONIGHT WITH THE POSSIBILITY OF WET MICROBURSTS. ...NRN HIGH PLAINS... MODELS GENERATE AREA OF POSSIBLE CONVECTION OVER THE NRN HIGH PLAINS FOR LATER THIS AFTERNOON/EARLY EVENING. ANALYSIS OF FORECAST SOUNDINGS SHOWED VERY STEEP LAPSE RATES NEAR/AROUND 9C/KM ...YET WITH A HIGH LFC AND DRYING IN LOW/MID LEVELS BY THIS EVENING AHEAD OF THE APPROACHING TROUGH. THUS...WOULD EXPECT THAT ISOLATED THUNDERSTORMS COULD DEVELOP LATER THIS AFTERNOON BUT REMAIN BELOW SEVERE LEVELS DUE TO LIMITED MOISTURE/INSTABILITY. ..MCCARTHY/JEWELL.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 20:02:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 16:02:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301959 SWODY1 SPC AC 301957 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0257 PM CDT WED AUG 30 2006 VALID 302000Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST AND MID ATLANTIC... ...SOUTHEAST TO MID ATLANTIC... ROBUST MULTICELLULAR CONVECTION HAS ERUPTED WITHIN VERY MOIST AND STRONGLY UNSTABLE AIR MASS FROM SRN AL/GA BORDER AREA NEWD ACROSS THE CAROLINAS TO VA/WV. PRESENCE OF RESIDUAL FRONT/OUTFLOW AND WEAK FRONTAL WAVE ACROSS NC HAS FOCUSED MOST VIGOROUS STORMS ACROSS ECNTRL NC WITH ADDITIONAL ACTIVITY INCREASING ACROSS THE MOUNTAINS AND OVER THE COASTAL PLAIN. WHILE STRONGER DEEP-LAYER SHEAR RESIDES NORTH OF NC CONVECTION...AND LARGER SCALE SUPPORT TO SUSTAIN UPWARD MOTION APPEARS LIMITED...MAGNITUDE OF INSTABILITY AND COVERAGE OF CONVECTION SHOULD RESULT IN SCATTERED DAMAGING WINDS AND SOME SEVERE HAIL THROUGH EARLY EVENING. LONG-LIVED SUPERCELL HAS BEEN TRACKING EAST ACROSS WRN WV AND APPEARS LINKED WITH SUB-SYNOPTIC SCALE LOW TRAVELING EAST ALONG LOW LEVEL BAROCLINIC ZONE. SHEAR ACROSS THE AREA REMAINS SUPPORTIVE OF STORM ROTATION AND INSTABILITY HAS BEEN STEADILY INCREASING ALONG AND SOUTH OF THE BOUNDARY. THUS...SEVERE HAIL AND WIND THREAT MAY PERSIST FROM WV EWD INTO PARTS OF WRN/SCNTRL VA OVER THE NEXT FEW HOURS. ...ERN FL... T.D. ERNESTO APPEARS TO BE ACCELERATING NNEWD TOWARD ERN FL LATE THIS AFTERNOON WITH THE CENTER OF THE CIRCULATION ON TRACK TO MOVE OVER THE EAST COAST LATE TONIGHT. WIND FIELDS IN THE RIGHT FRONT QUADRANT OF THE CIRCULATION WILL REMAIN MARGINALLY SUPPORTIVE OF LOW LEVEL UPDRAFT ROTATION AND AN ISOLATED TORNADO CANNOT BE RULED OUT. HOWEVER...OVERALL DISORGANIZED BANDING AND WEAK INSTABILITY AHEAD OF THE LOW TRACK DO NOT...ATTM...APPEAR PARTICULARLY SUPPORTIVE FOR DISCRETE AND PERSISTENT STORMS. ...SRN AZ... VERY STRONG INSTABILITY HAS DEVELOPED ACROSS SRN AZ WHERE DEWPOINTS IN THE 60S AND INTENSE SURFACE HEATING ARE CONTRIBUTING TO MLCAPE AROUND 2000 J/KG. FORCING AND SHEAR ACROSS THE REGION ARE EXPECTED TO REMAIN WEAK BUT ISOLATED CONVECTION COULD POSE SOME DAMAGING WIND POTENTIAL INTO THE EVENING. ...NRN HIGH PLAINS... NARROW N-S AXIS OF STRONG INSTABILITY HAS DEVELOPED NEAR LEE-TROUGH/DRYLINE ACROSS THE HIGH PLAINS. WHILE CAP REMAINS QUITE STRONG ACROSS MUCH OF THE REGION...RAP MORNING SOUNDING ADJUSTED FOR LATEST SURFACE CONDITIONS REVEALS THAT INHIBITION ACROSS THIS AREA HAS WEAKENED CONSIDERABLY. A FEW MORE HOURS OF HEATING/MIXING...AND PERHAPS OROGRAPHIC FORCING NEAR THE BLACK HILLS...MAY PROVE SUFFICIENT FOR ISOLATED STORM DEVELOPMENT. EFFECTIVE SHEAR APPROACHING 30KT WILL FURTHER ENHANCE UPDRAFTS AND CONTRIBUTE TO SEVERE HAIL/WIND POTENTIAL WITH ANY STORMS THAT MAY FORM. ADDITIONAL ACTIVITY MAY DEVELOP LATER TONIGHT ACROSS PARTS OF THE NRN PLAINS IN RESPONSE TO APPROACHING UPPER TROUGH AND COLD FRONT. STRONG EML AND LIMITED MOISTURE ARE EXPECTED TO RESTRICT SEVERE POTENTIAL WITH THIS CONVECTION. ..CARBIN.. 08/30/2006  From swody1 at goshenarc.org Thu Aug 31 00:46:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 20:46:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310048 SWODY1 SPC AC 310046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 PM CDT WED AUG 30 2006 VALID 310100Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... ERNESTO CONTINUES ITS NNEWD MOVEMENT ALONG THE ECNTRL FL COAST THIS EVENING. STRONGER SHEAR ASSOCIATED WITH CIRCULATION CENTER WILL SOON BE MOSTLY OFFSHORE...ALONG WITH ANY MEANINGFUL THREAT FOR SUPERCELLS. IT APPEARS THE GREATEST THREAT FOR STRONG STORMS THE REST OF THE PERIOD WILL BE WELL INLAND FROM THE FL PANHANDLE...NEWD AROUND THE PERIPHERY OF THE TROPICAL CIRCULATION INTO COASTAL NC. HOWEVER...00Z SOUNDINGS FROM THIS REGION SUGGEST LOW LEVEL LAPSE RATE ENVIRONMENT IS BEGINNING TO STABILIZE. ADDITIONAL BOUNDARY LAYER COOLING WILL NOT PROVE HELPFUL FOR SEVERE DEVELOPMENT THE REST OF TONIGHT. GUSTY WINDS ARE THE PRIMARY SEVERE THREAT WITH MCS CLUSTERS ACROSS THE FL PANHANDLE AND OVER COASTAL NC. ...BLACK HILLS/NEB PANHANDLE... ISOLATED THUNDERSTORM ACTIVITY ACROSS WRN SD INTO THE NWRN NEB PANHANDLE IS STRUGGLING TO MAINTAIN BOUNDARY LAYER PARCEL INFLOW. SIGNIFICANT AMOUNT OF INHIBITION WILL LIKELY RESULT IN THIS ACTIVITY BECOMING ROOTED ABOVE THE BOUNDARY LAYER SHORTLY. LLJ MAY MAINTAIN THIS CONVECTION FOR SEVERAL HOURS BUT SEVERE THREAT APPEARS RATHER LOW. ...AZ... STEEP LAPSE RATES ACROSS THE AZ DESERTS WILL PROVE SOMEWHAT SUPPORTIVE OF GUSTY WINDS BENEATH SCATTERED THUNDERSTORMS PROPAGATING SWWD INTO YUMA COUNTY. COLD POOL IS NOT PARTICULARLY ESTABLISHED SO SEVERE THREAT SHOULD REMAIN ISOLATED. ..DARROW.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 05:50:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 01:50:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310551 SWODY1 SPC AC 310549 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1249 AM CDT THU AUG 31 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL PLAINS... LEE CYCLONE SHOULD DEVELOP OVER ERN CO...WELL AHEAD OF MAIN FRONTAL BOUNDARY THAT SHOULD PLUNGE SWD THROUGH WY LATER THIS MORNING. LATE EVENING MODEL GUIDANCE SUGGESTS ELY COMPONENT SHOULD DEVELOP THROUGH AT LEAST 2KM ACROSS THE CENTRAL HIGH PLAINS BY MID AFTERNOON WHICH WILL ENHANCE LOW LEVEL CONVERGENCE/ASCENT WITHIN SLIGHT RISK REGION. ALTHOUGH LARGE SCALE HEIGHT FALLS WILL SPREAD ACROSS THE NRN PLAINS...SRN INFLUENCE OF UPPER TROUGH SHOULD STRENGTHEN WLY FLOW ALOFT AS FAR SOUTH AS I-70...ENHANCING DEEP LAYER SHEAR WHERE THUNDERSTORM DEVELOPMENT IS EXPECTED. IT APPEARS SUFFICIENT VERTICAL SHEAR WILL EXIST ACROSS ERN CO INTO WRN KS TO SUPPORT STORM ROTATION AND SUPERCELL DEVELOPMENT...ESPECIALLY EARLY IN CONVECTIVE CYCLE. IN THE ABSENCE OF SIGNIFICANT INHIBITION...CONVECTION SHOULD EVOLVE IN THE 20Z-21Z TIME FRAME OVER NERN CO INTO SWRN NEB...THEN SPREAD/DEVELOP SEWD ACROSS MUCH OF ERN CO/WRN KS. LARGE HAIL SHOULD ACCOMPANY THIS ACTIVITY...ALONG WITH SOME THREAT FOR DAMAGING WINDS...ESPECIALLY AS CONVECTION MERGES AND EVOLVES INTO CLUSTER-TYPE ECHOES. ONE OR MORE SMALL MCS/S SHOULD SPREAD SEWD TOWARD NWRN OK/NRN TX PANHANDLE AFTER MIDNIGHT. ...ERNESTO... CENTER OF TROPICAL STORM ERNESTO HAS MOVED OFF THE FL COAST AND IS LIFTING NNEWD TOWARD THE SC/NC COAST. STRONGER CONVECTIVE BANDS WILL SPREAD INTO THE CAROLINAS LATER TODAY WITH AT LEAST SOME THREAT FOR MARGINALLY SEVERE WIND GUSTS...OR PERHAPS A WEAK TORNADO. IN THE ABSENCE OF SIGNIFICANT STRENGTHENING OVER THE WARMER ATLANTIC WATERS...LOW PROBABILITIES WILL SUFFICE FOR THE SERN U.S. ...AZ... PRECIPITABLE WATER VALUES REMAIN QUITE HIGH ACROSS THE LOWER ELEVATION REGIONS OF AZ THIS MORNING...WITH READINGS WELL ABOVE AN INCH IN MOST PLACES. LATEST WV IMAGERY SUGGESTS A WEAK UPPER DISTURBANCE IS LOCATED JUST SW OF AZ OVER THE NRN BAJA REGION/GULF OF CA...LIFTING NEWD AROUND THE UPPER RIDGE. TIMING OF THIS FEATURE IS NOT PARTICULARLY FAVORABLE FOR LATE AFTERNOON CONVECTION...HOWEVER PARCELS SHOULD ONCE AGAIN REACH THEIR LFC WITH MID 90S TO NEAR 100F. ISOLATED STORMS MAY PRODUCE GUSTY WINDS GIVEN HIGH WATER CONTENT...STEEP LAPSE RATE ENVIRONMENT. ..DARROW/CROSBIE.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 12:35:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 08:35:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311235 SWODY1 SPC AC 311234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT THU AUG 31 2006 VALID 311300Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY THROUGH TONIGHT ACROSS THE ERN CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS THE CENTRAL HIGH PLAINS... ...ERN CAROLINAS THROUGH TONIGHT... TROPICAL STORM ERNESTO IS EXPECTED TO MAKE LANDFALL TONIGHT NEAR THE NC/SC BORDER AND CONTINUE MOVING NWD ACROSS ERN NC THROUGH 01/12Z. MODEST STRENGTHENING OF THE TROPICAL CYCLONE PRIOR TO LANDFALL WILL RESULT IN A BROADER AREA OF STRONGER LOW-MID LEVEL FLOW IN ADVANCE OF THE STORM CORE. ADDITIONALLY...THE FORWARD QUADRANTS OF ERNESTO WILL BEGIN TO INTERACT WITH A BAROCLINIC ZONE ACROSS THE ERN CAROLINAS. THIS WILL PROVIDE A CORRIDOR OF ENHANCED LOW-LEVEL SHEAR TO FOCUS THE SUPERCELL/TORNADO THREAT AS BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 70S AND ASSOCIATED LOW-LEVEL BUOYANCY SPREAD INLAND LATER TODAY AND TONIGHT. ...CENTRAL HIGH PLAINS THIS AFTERNOON/EVENING... A STRONG SURFACE COLD FRONT WILL MOVE EWD ACROSS THE NRN PLAINS IN ASSOCIATION WITH A MID LEVEL TROUGH OVER THE NRN ROCKIES...AND THE FRONT WILL MOVE SWD INTO ERN CO. BOUNDARY LAYER DEWPOINTS OF 58-62 F ARE RETURNING NWD ACROSS THE HIGH PLAINS IN A NARROW CORRIDOR E OF THE LEE TROUGH. THIS MOISTURE...COMBINED WITH AFTERNOON TEMPERATURES OF 85-90 F AND STEEP MID LEVEL LAPSE RATES...WILL RESULT IN MODERATE INSTABILITY IN THE WARM SECTOR BY AFTERNOON /MLCAPE VALUES OF 1500-2000 J/KG/. EXPECT THUNDERSTORMS TO DEVELOP BY MID-LATE AFTERNOON NEAR THE COLD FRONT/LEE TROUGH INTERSECTION IN NE CO...AND CONVECTION SHOULD SPREAD EWD/SEWD THROUGH THE EVENING ACROSS SW NEB/ERN CO/WRN KS. VERTICAL SHEAR IS FORECAST TO REMAIN SOMEWHAT MARGINAL FOR SUPERCELLS...THOUGH SUFFICIENT FOR PERSISTENT MULTICELL CLUSTERS. LARGE HAIL AND A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREATS FROM ABOUT 21-03Z. ..THOMPSON/CROSBIE.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 16:23:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 12:23:21 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311623 SWODY1 SPC AC 311622 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CDT THU AUG 31 2006 VALID 311630Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE ERN CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL HIGH PLAINS... ...ERN CAROLINAS... LATEST INFORMATION FROM NHC INDICATES ERNESTO HAS STRENGTHENED OVERNIGHT OFF THE GA COAST. THE CIRCULATION CENTER IS FORECAST TO MOVE NNEWD MAKING LANDFALL NEAR THE SC/NC BORDER AROUND 05-06Z AND CONTINUING INTO ERN NC DURING THE REMAINDER OF THE PERIOD. STRONGER LOW LEVEL WIND FIELDS AND ATTENDANT VERTICAL SHEAR WITHIN NERN QUADRANT OF THE SYSTEM WILL GRADUALLY SPREAD ONSHORE THIS AFTERNOON AND TONIGHT INTO COASTAL REGIONS OF NERN SC AND NC...INCREASING POTENTIAL FOR A FEW SUPERCELL THUNDERSTORMS. IN ADDITION...COASTAL BOUNDARY IN ADVANCE OF ERNESTO CURRENTLY LOCATED ALONG THE NC COAST IS EXPECTED TO MOVE INLAND BY TONIGHT AND FURTHER ENHANCE LOW LEVEL SHEAR PROFILES. THIS MAY PROVIDE A FOCUS FOR SUPERCELL DEVELOPMENT WITH THREAT FOR ISOLATED TORNADOES CONTINUING THROUGH THE OVERNIGHT HOURS. ...CENTRAL HIGH PLAINS... SRN PORTION OF UPPER SHORT WAVE TROUGH MOVING ACROSS MT/WY IS EXPECTED TO MOVE INTO THE NRN PLAINS TONIGHT. THIS SYSTEM WILL FORCE SURFACE COLD FRONT EWD/SEWD ACROSS THE NRN AND CENTRAL PLAINS THIS AFTERNOON AND TONIGHT. 12Z AREA SOUNDINGS EXHIBIT STEEP MID LEVEL LAPSE RATES...AND SURFACE DEW POINTS IN THE 50S TO LOWER 60S COUPLED WITH STRONG DIABATIC INSOLATION THIS AFTERNOON WILL RESULT IN MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE OF 1500-2000 J/KG. ALTHOUGH STRONGEST DYNAMIC FORCING FOR LARGE SCALE ASCENT WILL BE LOCATED WELL NORTH OF THE PLAINS...PROGRESSION OF A WEAK UPPER LEVEL JET STREAK ACROSS THE CENTRAL ROCKIES WITH DIFFLUENT MID/UPPER LEVEL FLOW DOWNSTREAM OVER THE HIGH PLAINS...LOW LEVEL CONVERGENCE ALONG THE ADVANCING COLD FRONT...AND UPSLOPE LOW LEVEL WIND COMPONENT FAVOR DEVELOPMENT OF THUNDERSTORMS LATER THIS AFTERNOON AND EVENING FROM PARTS OF NERN CO INTO WRN/CENTRAL NEB. THIS ACTIVITY IS EXPECTED TO SPREAD EWD/SEWD INTO SERN CO/WRN KS AND POSSIBLY THE OK PANHANDLE REGION THROUGH THE EVENING BEFORE DIMINISHING LATER AT NIGHT. DEEP LAYER VERTICAL SHEAR OF 30-35 KT WILL BE SUPPORTIVE OF PRIMARILY MULTICELLULAR CONVECTIVE STRUCTURES ALTHOUGH ISOLATED SUPERCELLS WILL ALSO BE POSSIBLE. LARGE HAIL AND OCCASIONAL DAMAGING WIND GUSTS WILL BE POSSIBLE WITH STRONGER CELLS. ..WEISS/JEWELL.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 20:01:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 16:01:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 312002 SWODY1 SPC AC 312000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT THU AUG 31 2006 VALID 312000Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN CAROLINAS... ...ERN CO/WRN KS/SW NEB... LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE CNTRL HIGH PLAINS WITH A DISTURBANCE/VORTICITY MAX MOVING EWD THROUGH CNTRL AND SRN CO ATTM. AT THE SFC...A MOIST AXIS WITH DEWPOINTS IN THE 60-65 F RANGE EXISTS ACROSS WRN KS AND FAR NE CO WHERE OBJECTIVE ANALYSIS SHOWS MODERATE INSTABILITY WITH MLCAPE VALUES RANGING FROM 1500 TO 2000 J/KG. AS THE DISTURBANCE MOVES INTO THE PLAINS OF CO LATE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE IN FAR NE CO ALONG THE LEADING EDGE OF ASCENT AND ALONG THE WRN EDGE OF THE INSTABILITY AXIS. THE NAM AND GFS SOLUTIONS ARE CONSISTENT WITH THIS SCENARIO AND IT APPEARS AN MCS WILL DEVELOP AND MOVE EWD INTO NW KS BY THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION LATE THIS AFTERNOON SHOW SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STORMS AND SHEAR PROFILES MAY INCREASE THIS EVENING AS A 30-40 KT LOW-LEVEL JET STRENGTHENS ACROSS WRN KS. THIS COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES ALREADY IN PLACE SUGGEST SUPERCELLS WITH LARGE HAIL WILL BE LIKELY AS THE MCS ORGANIZES THIS EVENING. THE SEVERE THREAT MAY ALSO EXPAND SWD WITH TIME AS THE MCS ORGANIZES ACROSS WRN KS THIS EVENING. ...ERN SC/ERN NC... TROPICAL STORM ERNESTO WILL CONTINUE TO MOVE NWD THIS AFTERNOON AND IS FORECAST TO MOVE INLAND NEAR WILMINGTON NC OVERNIGHT. AT THE SFC...ELY FLOW WILL STRENGTHEN ACROSS ERN SC AND ERN NC AHEAD OF THE APPROACHING TROPICAL STORM. THIS WILL INCREASE SFC DEWPOINTS ACROSS THE REGION FROM EAST TO WEST ALLOWING MODERATE INSTABILITY TO DEVELOP TONIGHT. FORECAST SOUNDINGS ALSO INCREASE LOW-LEVEL SHEAR PROFILES AFTER MIDNIGHT ALONG AND NORTH OF THE CENTER OF TROPICAL STORM ERNESTO WITH THE STRONGER DEEP LAYER SHEAR PROFILES REMAINING EAST OF THE CENTER. THIS SUGGESTS ROTATING STORMS WITH TORNADO POTENTIAL WILL BE MOST LIKELY FROM FAR ERN SC EXTENDING NWD INTO ERN NC. THE TORNADO THREAT SHOULD BE GREATEST LATE TONIGHT AS THE INNER RAINBANDS OF TROPICAL STORM ERNESTO MOVE FURTHER INLAND. ..BROYLES.. 08/31/2006  From swody1 at goshenarc.org Tue Aug 1 00:53:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 31 Jul 2006 20:53:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010053 SWODY1 SPC AC 010051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 PM CDT MON JUL 31 2006 VALID 010100Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PORTIONS OF THE UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PARTS OF UPSTATE NY INTO WRN/CNTRL NEW ENGLAND... ...UPPER GREAT LAKES... CLUSTERS OF TSTMS ARE ONGOING THIS EVENING ALONG AND AHEAD OF SURFACE COLD FRONT FROM THE ARROWHEAD SWWD INTO ERN SD WITHIN MODERATE TO STRONGLY UNSTABLE ENVIRONMENT CHARACTERIZED BY MLCAPES OF 1500-3500 J/KG. HIGH RESOLUTION RADAR IMAGERY SUGGESTS THAT THE COMBINATION OF FRONTAL SURGE AND COLD POOL GENERATION HAVE LARGELY UNDERCUT MUCH OF THIS ACTIVITY...AND THIS TEND SHOULD LIMIT A MORE ORGANIZED SEVERE THREAT. 00Z SOUNDINGS FROM INL/MPX INDICATE THAT STRONGEST DEEP-LAYER SHEAR IS DISPLACED TO THE N OF STRONGER INSTABILITY IN PLACE ACROSS E-CNTRL MN INTO NRN WI. BASED ON THIS INFORMATION...IT APPEARS THE GREATEST SEVERE THREAT WILL EXIST FROM PORTIONS OF CNTRL MN EWD INTO NWRN WI WHERE STRONGEST INSTABILITY WILL BE CO-LOCATED WITH SRN FRINGE OF MARGINALLY STRONG DEEP LAYER SHEAR. THE MOST INTENSE STORMS WILL REMAIN CAPABLE OF LOCALLY DAMAGING WINDS AND SOME SEVERE HAIL. ...PORTIONS OF UPSTATE NY INTO WRN/CNTRL NEW ENGLAND... VISIBLE SATELLITE AND LIGHTNING DATA INDICATE THE GRADUAL ORGANIZATION OF A NW-SE ORIENTED BAND OF TSTMS FROM SWRN QUEBEC INTO THE NRN ADIRONDACKS...DRIVEN LARGELY BY LOW-LEVEL WAA N OF RETREATING SURFACE WARM FRONT. 00Z SOUNDINGS FROM BUF AND ALB SHOW THAT INSTABILITY REMAINS SOMEWHAT MARGINAL OWING TO THE WEAK MID-LEVEL LAPSE RATES WITH MLCAPES OF AROUND 500 J/KG. HOWEVER THESE SOUNDINGS AND BURLINGTON VT VWP INDICATE STRONG LOW-LEVEL VEERING WITH HEIGHT WITH 45-55 KTS OF DEEP-LAYER SHEAR. STRENGTHENING WLY LLJ FROM THE UPPER MIDWEST INTO THE ST. LAWRENCE VALLEY SHOULD SUPPORT REGENERATIVE TSTM DEVELOPMENT OVERNIGHT FROM SWRN QUEBEC INTO PORTIONS OF UPSTATE NY AND WRN NEW ENGLAND. DESPITE THE MARGINAL INSTABILITY...THE RELATIVELY STRONG SHEAR SHOULD SUPPORT A FEW ORGANIZED STORMS /INCLUDING SUPERCELLS AND BOWING STRUCTURES/ CAPABLE OF MAINLY DAMAGING WINDS AND PERHAPS SOME HAIL. ..MEAD.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 05:38:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 01:38:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 010538 SWODY1 SPC AC 010536 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1236 AM CDT TUE AUG 01 2006 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER GREAT LAKES INTO THE MID MO VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE UPPER HUDSON VALLEY INTO NRN AND CNTRL NEW ENGLAND... ...SYNOPSIS... A RATHER LOW-AMPLITUDE...PROGRESSIVE LARGE-SCALE PATTERN WILL EXIST ACROSS SRN CANADA AND THE NRN TIER OF STATES DURING THE DAY ONE PERIOD. WITHIN THIS REGIME...STRONG SHORT WAVE TROUGH OVER WRN ONTARIO WILL TRANSLATE EWD INTO QUEBEC...EFFECTIVELY LOWERING HEIGHTS OVER THE ST. LAWRENCE VALLEY DURING THE LATTER HALF OF THE FORECAST. MEANWHILE TO THE W...PRIMARY SHORT WAVE TROUGH /NOW OVER NV/ WILL TEND TO DE-AMPLIFY AS IT LIFTS NEWD INTO THE NRN PLAINS. A WEAKER IMPULSE /CURRENTLY OVER THE CNTRL ROCKIES/ WILL PRECEED THE NV WAVE INTO THE CNTRL PLAINS WHILE SHEAR AXIS OVER NM SLOWLY SHIFTS EWD INTO THE CNTRL/SRN HIGH PLAINS. IN THE LOW-LEVELS...NW-SE ORIENTED WARM FRONT WILL LIFT NEWD THROUGH NEW ENGLAND TODAY WHILE TRAILING FRONTAL BOUNDARY SLOWLY SAGS SWD THROUGH THE UPPER GREAT LAKES AND CNTRL PLAINS REGIONS. SURFACE LOW PRESSURE INITIALLY OVER NWRN KS WILL DEVELOP NEWD ALONG THIS BOUNDARY INTO THE MID MO VALLEY BY THIS EVENING. ...UPPER GREAT LAKES INTO MID MO VALLEY... AS MENTIONED ABOVE...WEAKER SHORT WAVE TROUGH /NOW LIFTING NEWD INTO WY/ WILL PRECEDE PRIMARY WAVE WITH FORCING FOR ASCENT ASSOCIATED WITH THIS FEATURE SHIFTING EWD INTO PLAINS FAIRLY EARLY IN THE DAY. AS A CONSEQUENCE...LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT CONSIDERABLE CLOUDS/PRECIPITATION MAY EXIST NEAR OR JUST N OF FRONTAL ZONE FROM NEB INTO SRN MN...WHICH COULD LIMIT THE DEGREE OF DESTABILIZATION. IT DOES APPEAR THAT AIR MASS S OF FRONTAL ZONE OVER KS NEWD INTO THE MIDWEST WILL EXPERIENCE STRONG DIABATIC HEATING...WHICH WHEN COUPLED WITH MODEST BOUNDARY LAYER MOISTURE...WILL SUPPORT MLCAPES OF 1000-2500 J/KG. DIURNAL TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY BY MID TO LATE AFTERNOON ALONG FRONT OR DIFFERENTIAL HEATING/OUTFLOW BOUNDARIES FROM THE CNTRL HIGH PLAINS NEWD THROUGH THE MID MO VALLEY INTO WI AND PORTIONS OF LOWER MI. FORECAST SOUNDINGS INDICATE MODESTLY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL WITH QUITE WEAK WIND FIELDS ABOVE 6-7 KM AGL...ESPECIALLY OVER THE WRN PORTION OF SLIGHT RISK AREA. THIS WOULD SUGGEST THE POTENTIAL FOR SOME UPDRAFT ROTATION EARLY IN STORM LIFE CYCLES WITH A GRADUAL TRANSITION TO OUTFLOW DOMINANT MULTICELL CLUSTERS OR A BROKEN LINE. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL PRODUCTION WITH THE PRIMARY SEVERE WEATHER THREAT BEING DAMAGING WINDS. ...NRN/CNTRL NEW ENGLAND... CLUSTERS OF STRONG TO POTENTIALLY SEVERE STORMS CAPABLE OF LOCALLY DAMAGING WINDS MAY BE ONGOING AT THE ONSET OF THE FORECAST FROM NERN NY INTO NRN NEW ENGLAND IN ASSOCIATION WITH LOW-LEVEL WAA OCCURRING N OF SURFACE WARM FRONT. THIS ACTIVITY SHOULD SHIFT SEWD OR EWD THROUGH THE MORNING HOURS. HEIGHT RISES/INTENSIFYING CAP IN WAKE OF SURFACE WARM FRONTAL PASSAGE AND WITHIN SLIGHT RIDGING AHEAD OF QUEBEC SHORT WAVE TROUGH WILL LIKELY SUPPRESS ANY SEVERE CONVECTION THROUGH THE AFTERNOON HOURS...PERHAPS INTO EARLY EVENING. HOWEVER WITH TIME...HEIGHT FALLS ON SERN PERIPHERY OF QUEBEC SHORT WAVE TROUGH SHOULD SUPPORT AN INCREASE IN TSTM ACTIVITY OVER THE ST. LAWRENCE VALLEY WITH STORMS BECOMING INCREASINGLY LIKELY ACROSS NRN/CNTRL NEW ENGLAND TONIGHT. STRONG WLY DEEP SHEAR OF 40-50 KT INDICATES THE POTENTIAL FOR EMBEDDED BOWING STRUCTURES CAPABLE OF MAINLY DAMAGING WINDS. ..MEAD/GRAMS.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 12:57:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 08:57:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011257 SWODY1 SPC AC 011255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 AM CDT TUE AUG 01 2006 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER NERN NY AND NRN /CNTRL NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MO VLY TO THE UPR GRT LKS... ...SYNOPSIS... SUBTROPICAL UPR RIDGE WILL ELONGATE E TO THE MID ATLANTIC CST THIS PERIOD AS BELT OF STRONG WLY FLOW ASSOCIATED WITH NRN ONTARIO SHORTWAVE TROUGH OVERSPREADS CNTRL QUEBEC AND THE LWR ST LAWRENCE VLY. IN THE WEST...TROUGH OVER THE NRN GRT BASIN SHOULD CONTINUE ENE TO THE NRN PLNS WHILE A SERIES OF WEAKER IMPULSES MOVE NEWD IN BELT OF ENHANCED FLOW EXTENDING FROM THE SRN HI PLNS TO THE UPR MS VLY. SURFACE LOW ACCOMPANYING THE ONTARIO DISTURBANCE SHOULD TRACK E ACROSS QUEBEC...ALLOWING NW-SE ORIENTED WARM FRONT NOW IN WRN NEW ENGLAND TO REDEVELOP E INTO NRN AND CNTRL ME BY LATE IN THE DAY. FARTHER W...TRAILING COLD FRONT WITH WAVES EXPECTED TO DRIFT SLOWLY S/SE ACROSS THE CNTRL PLNS...THE MID/UPR MS VLY AND THE UPR GRT LKS. ...NE NY INTO NRN/CNTRL NEW ENGLAND... CLUSTERS OF TSTMS SHOULD CONTINUE TO FORM INVOF WARM FRONT OVER SW/S CNTRL QUEBEC TODAY...WHERE 30+ KT WARM/MOIST WLY LLJ WILL MOST STRONGLY IMPINGE ON BOUNDARY. MORE ISOLATED DEVELOPMENT MAY ALSO OCCUR SWD INTO NERN NY AND WRN/NRN NEW ENGLAND...WHERE HEIGHT RISES ASSOCIATED WITH ELONGATING RIDGE WILL TEND TO SUPPRESS DEVELOPMENT ...BUT SUBSTANTIAL DIFFERENTIAL HEATING WILL EXIST. THE AXIS OF DEVELOPMENT LIKELY WILL SHIFT E WITH TIME WITH MOTION OF FRONT. BY EARLY EVENING...COMBINATION OF DIURNAL HEATING AND LARGE SCALE ASCENT ON SRN FRINGE OF QUEBEC SHORTWAVE IMPULSE SHOULD SUPPORT INCREASED STORM DEVELOPMENT ALONG BOTH THE WARM FRONT...AND ALONG COLD FRONT SETTLING S OVER THE ST. LAWRENCE VLY. THIS ACTIVITY SHOULD CONTINUE E/ESE ACROSS NRN NEW ENGLAND TONIGHT/EARLY WEDNESDAY. GIVEN MODERATE TO STRONG /30-40 KT/ DEEP W TO NWLY CLOUD-LAYER FLOW...AND MODEST DIRECTIONAL SHEAR...EMBEDDED SUSTAINED STORMS/ SUPERCELLS APPEAR LIKELY. ASSOCIATED BOWING SEGMENTS COULD YIELD DAMAGING WIND AND POSSIBLY A TORNADO...IN ADDITION TO VERY HEAVY RAIN...AS PWS REMAIN AROUND 2 INCHES. ...MID MO VLY TO UPR GRT LKS... STORM OUTFLOW/LOW LEVEL DIVERGENCE ASSOCIATED WITH WEAK IMPULSE LIFTING NE ACROSS THE CNTRL PLNS LIKELY WILL MITIGATE SEVERE THREAT OVER PARTS OF NEB AND IA TODAY. HOWEVER...AIR MASS E OF OUTFLOW BOUNDARY/COLD FRONT SHOULD DESTABILIZE WITH DAYTIME HEATING. MLCAPE TO 2500 J/KG WILL BE POSSIBLE OVER KS...AND FROM ERN IA INTO CNTRL/SRN WI AND LWR MI. WHILE ELEVATED STORMS COULD POSE A LIMITED SEVERE THREAT LATER TODAY INTO TONIGHT INVOF FRONT OVER CNTRL/ERN NEB INTO ERN SD...GREATER CHANCE FOR SEVERE SHOULD ACCOMPANY MORE SURFACE-BASED ACTIVITY FROM ERN IA INTO WI/LWR MI. FORECAST SOUNDINGS INDICATE MODERATELY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL...WITH WEAK WINDS ABOVE 6-7 KM...ESPECIALLY OVER THE WRN PART OF SLIGHT RISK AREA. THIS SUGGESTS THE POTENTIAL FOR UPDRAFT ROTATION EARLY IN STORM LIFE CYCLES...BUT WITH A FAIRLY RAPID EVOLUTION TO OUTFLOW DOMINANT MULTICELL CLUSTERS/BROKEN LINES. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL POTENTIAL...WITH THE PRIMARY SEVERE THREAT BEING DAMAGING WIND. ...SERN U.S... WWD-MOVING UPR IMPULSE MAY ENHANCE POTENTIAL FOR A CLUSTER OR TWO OF DIURNAL PULSE STORMS WITH LOCALLY DAMAGING WIND IN MS/AL AND THE FL PANHANDLE REGION. ..CORFIDI/GRAMS.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 16:33:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 12:33:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011634 SWODY1 SPC AC 011633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 1133 AM CDT TUE AUG 01 2006 VALID 011630Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NEB THROUGH UPR GRT LKS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NY THROUGH NRN / CNTRL NEW ENGLAND... ...SYNOPSIS... SUBTROPICAL UPR RIDGE WILL ELONGATE E TO THE MID ATLANTIC CST THIS PERIOD AS BELT OF STRONG WLY FLOW ASSOCIATED WITH SRN QUEBEC SHORTWAVE TROUGH OVERSPREADS LWR ST LAWRENCE VLY. IN THE WEST...TROUGH OVER THE NRN GRT BASIN SHOULD CONTINUE ENE TO THE NRN PLNS WHILE A SERIES OF WEAKER IMPULSES MOVE NEWD IN BELT OF ENHANCED FLOW EXTENDING FROM THE SRN HI PLNS TO THE UPR MS VLY. SURFACE LOW ACCOMPANYING THE ONTARIO DISTURBANCE SHOULD TRACK E ACROSS QUEBEC...ALLOWING NW-SE ORIENTED WARM FRONT NOW MOVING INTO MAINE. FARTHER W...TRAILING COLD FRONT EXPECTED TO DRIFT SLOWLY S/SE ACROSS THE CNTRL PLNS...THE MID/UPR MS VLY AND THE UPR GRT LKS. ...NE NY INTO NRN/CNTRL NEW ENGLAND... ONE CLUSTER OF STORMS ALREADY MOVING SE OUT OF QUEBEC INTO NRN VT/WRN ME...WITH ANOTHER CLUSTER MOVING SE THROUGH QUEBEC. WARM/MOIST SWLY LLJ PLUS LARGE SCALE LOW LEVEL ASCENT WILL RESULT IN CONTINUED THUNDERSTORM DEVELOPMENT THROUGH THE NIGHT. SEVERE THREAT MAY BE MITIGATED BY UPPER RIDGING AND WARM TEMPERATURES ALOFT ON THE WESTERN END OF THE SLIGHT RISK. BY EARLY EVENING...COMBINATION OF DIURNAL HEATING...LACK OF CONVECTIVE INHIBITION...AND LARGE SCALE ASCENT ON SRN FRINGE OF QUEBEC SHORTWAVE IMPULSE SHOULD SUPPORT INCREASED STORM DEVELOPMENT ALONG BOTH THE WARM FRONT...AND ALONG COLD FRONT SETTLING S OVER THE ST. LAWRENCE VLY. THIS ACTIVITY SHOULD CONTINUE E/ESE ACROSS NRN NEW ENGLAND TONIGHT/EARLY WEDNESDAY. GIVEN MODERATE TO STRONG /30-40 KT/ DEEP W TO NWLY CLOUD-LAYER FLOW...AND MODEST DIRECTIONAL SHEAR...EMBEDDED SUSTAINED STORMS/SUPERCELLS APPEAR LIKELY. ASSOCIATED BOWING SEGMENTS COULD YIELD DAMAGING WIND AND POSSIBLY A TORNADO...IN ADDITION TO VERY HEAVY RAIN...AS PWS REMAIN AROUND 2 INCHES. ...MID MO VLY TO UPR GRT LKS... STORM OUTFLOW/LOW LEVEL DIVERGENCE ASSOCIATED WITH WEAK IMPULSE LIFTING NE ACROSS THE CNTRL PLNS LIKELY WILL MITIGATE SEVERE THREAT OVER PARTS OF NEB AND IA TODAY. HOWEVER...AIR MASS E OF OUTFLOW BOUNDARY/COLD FRONT SHOULD DESTABILIZE WITH DAYTIME HEATING. MLCAPE TO 2500 J/KG WILL BE POSSIBLE OVER IA...AND FROM ERN IA INTO CNTRL/SRN WI AND LWR MI. WHILE ELEVATED STORMS COULD POSE A LIMITED SEVERE THREAT INVOF FRONT OVER ERN NEB INTO WRN IA...GREATER CHANCE FOR SEVERE IS POSSIBLE IN ERN IA THROUGH WI/LWR MI WHERE LACK OF CLOUD COVER RESULTS IN STRONGER AFTERNOON HEATING. WARM THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL POTENTIAL...WITH THE PRIMARY SEVERE THREAT BEING DAMAGING WIND. ...SERN U.S... WNWD-MOVING UPR IMPULSE OVER WRN AL MAY ENHANCE POTENTIAL FOR A CLUSTER OR TWO OF DIURNAL PULSE STORMS WITH LOCALLY DAMAGING WIND IN MS/AL AND THE FL PANHANDLE REGION. .,.GREAT BASIN... ISOLATED WIND DAMAGE POSSIBLE THIS AFTERNOON IN ASSOCIATION WITH UPPER TROUGH MOVING EWD. ..AFWA.. 08/01/2006  From swody1 at goshenarc.org Tue Aug 1 19:38:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 15:38:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 011929 SWODY1 SPC AC 011928 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE 0228 PM CDT TUE AUG 01 2006 VALID 012000Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS IN NEW YORK AND NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHWESTERN KANSAS/NEBRASKA INTO MICHIGAN... ...SYNOPSIS... UPPER TROUGH IN THE WESTERN CONUS AND SUBTROPICAL RIDGE CENTERED IN NORTH CAROLINA WILL REMAIN IN PLACE DURING THE FORECAST PERIOD. FRONTAL BOUNDARY ASSOCIATED WITH THE TROUGH EXTENDS FROM NORTHEASTERN KANSAS INTO SOUTHERN QUEBEC. THIS FRONT IS EXPECTED TO MOVE ONLY SLOWLY SOUTHEASTWARD INTO THIS EVENING. ...NEW YORK AND NEW ENGLAND... CONVECTIVE TEMPERATURES HAVE BEEN REACHED IN NEW YORK AND THUNDERSTORMS ARE BEGINNING TO DEVELOP. WITH DEWPOINTS IN THE MID AND UPPER 70S...MLCAPES ARE IN EXCESS OF 3000 J/KG DESPITE WARM MID LEVEL TEMPERATURES. NORTHWEST FLOW ON THE NRN PERIPHERY OF THE SUBTROPICAL RIDGE IS CONTRIBUTING TO DEEP LAYER SHEAR OF 25-35 KNOTS...WHICH WILL ALLOW FOR MULTICELLULAR THUNDERSTORM DEVELOPMENT. OTHER THUNDERSTORMS MAY ALSO FORM UPSTREAM IN ONTARIO/QUEBEC AND PROPAGATE SOUTHEASTWARD INTO THE AREA LATER THIS EVENING. GIVEN LOW LEVEL SHEAR AROUND 20 KNOTS AND DCAPE OVER 1000 J/KG...A DAMAGING WIND MCS IS POSSIBLE. HOWEVER...WARM MID LEVEL TEMPERATURES AND UPPER LEVEL RIDGING MAY TEND TO SUPPRESS WIDESPREAD THUNDERSTORM DEVELOPMENT. FURTHER NORTHEAST INTO NEW ENGLAND...CLOUD COVER IS HOLDING DOWN TEMPERATURES AND LIMITING INSTABILITY...ESPECIALLY INTO NORTHERN MAINE. THIS WILL TEND TO LIMIT THE SEVERE WEATHER THREAT. ...NORTHWESTERN KANSAS/NEBRASKA INTO MICHIGAN... SKIES HAVE CLEARED OUT OVER CENTRAL AND EASTERN NEBRASKA IN THE WAKE OF MORNING CONVECTION. RUC SOUNDINGS INDICATE MLCAPE AROUND 3000 J/KG WITH LITTLE MLCIN BY 2100 UTC. SCATTERED THUNDERSTORMS WILL DEVELOP AROUND THIS TIME AND SHOULD PRODUCE SOME DAMAGING WINDS GIVEN 30 KNOTS OF LOW LEVEL FLOW. WITH DEEP LAYER SHEAR AROUND 40 KNOTS...A FEW SUPERCELLS COULD FORM. MARGINALLY SEVERE HAIL IS POSSIBLE...BUT MID LEVEL LAPSE RATES ARE FAIRLY WEAK...AROUND 6.0 K/KM...SO WIND DAMAGE IS THE MAIN THREAT. FROM WISCONSIN INTO MICHIGAN THE DEEP LAYER SHEAR IS SOMEWHAT WEAKER AROUND 30 KNOTS...BUT LOW LEVEL FLOW OF 25 KNOTS IS STILL FAVORABLE FOR SOME DAMAGING WINDS. THUNDERSTORMS HAVE ALREADY DEVELOPED IN NORTHERN MICHIGAN AND THESE SHOULD INTENSIFY AND BECOME MORE WIDESPREAD ALONG THE FRONTAL BOUNDARY INTO THIS EVENING. ...UTAH/WYOMING/COLORADO... POTENT SHORTWAVE TROUGH CONTINUES TO FORCE THUNDERSTORMS IN WEAKLY UNSTABLE ENVIRONMENT. STRONG FLOW AROUND 30 KNOTS AT 600 MB WILL HELP ENHANCE AN ISOLATED DAMAGING WIND THREAT WITH ANY DOWNBURSTS THAT OCCUR IN STRONGER THUNDERSTORMS. ..AFWA.. 08/01/2006  From swody1 at goshenarc.org Wed Aug 2 00:58:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 01 Aug 2006 20:58:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020058 SWODY1 SPC AC 020056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT TUE AUG 01 2006 VALID 020100Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FROM THE MID MO VALLEY INTO PARTS OF THE UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER HUDSON VALLEY INTO NRN/CNTRL NEW ENGLAND... ...MID MO VALLEY INTO THE UPPER GREAT LAKES... EVENING WATER VAPOR IMAGERY SHOWS PRIMARY SHORT WAVE TROUGH LIFTING NEWD THROUGH WY WITH SEVERAL WEAKER DOWNSTREAM IMPULSES...TWO OF WHICH APPEAR TO BE OVER NRN WI AND CNTRL NEB. IN THE LOW-LEVELS...PRIMARY SURFACE LOW WAS LOCATED OVER CNTRL NEB WITH AN ATTENDANT FRONTAL BOUNDARY EXTENDING NEWD THROUGH SWRN MN/CNTRL WI INTO NRN LOWER MI. TRAILING PORTION OF THIS BOUNDARY THEN EXTENDED SWWD INTO WRN KS. AS OF 0015Z...MOST CONCENTRATED CLUSTERS OF STRONG/SEVERE STORMS EXIST OVER NERN NEB/NWRN IA AND NRN LAKE MI WITHIN ZONES OF STRONGER LARGE-SCALE FORCING ASSOCIATED WITH AFOREMENTIONED SHORT WAVE TROUGHS. 00Z OAX SOUNDING INDICATES THAT AMBIENT AIR MASS OVER THE MID MO VALLEY REMAINS MODERATELY UNSTABLE OWING TO MOIST BOUNDARY-LAYER CONDITIONS AND STEEP LOW-LEVEL LAPSE RATES WITH MLCAPES AROUND 2000 J/KG. FARTHER TO THE NE...MORE WIDESPREAD CLOUDS AND PRECIPITATION HAVE LIMITED DESTABILIZATION OVER SERN MN INTO NRN/CNTRL WI...THOUGH MLCAPES STILL REMAIN AROUND 1000 J/KG. INSTABILITY THEN INCREASES OVER LOWER MI OWING TO STRONGER DAYTIME HEATING WITH 00Z APX SOUNDING INDICATING MLCAPES OF AROUND 2000 J/KG. EXPECT GREATEST SEVERE THREAT TO CONTINUE THROUGH 03-05Z OVER PORTIONS OF NRN IA INTO SRN MN AND PARTS OF NRN LOWER MI WHERE AIR MASS REMAINS MOST UNSTABLE. 00Z OAX HODOGRAPH INDICATED MODEST LOW-LEVEL SHEAR WITH 0-1 KM SRH OF 150-200 M2/S2. HOWEVER...WIND FIELDS DECREASE SIGNIFICANTLY ABOVE 500 MB...SUGGESTING THAT STORMS SHOULD REMAIN OUTFLOW DOMINANT. WHILE A BRIEF TORNADO IS POSSIBLE WITH ANY ROTATING STORMS EARLY IN THEIR LIFE CYCLE... SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREATS. WIND PROFILES ARE MUCH MORE UNIDIRECTIONAL INTO THE UPPER GREAT LAKES WHICH SHOULD SUPPORT STORM FORWARD PROPAGATION WITH DAMAGING WINDS AND SOME HAIL BEING THE PRIMARY SEVERE THREATS. ...NEW ENGLAND... TSTMS CONTINUE TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING E OF WARM FRONT /NOW ALONG THE NH-ME BORDER/ OVER PORTIONS OF NWRN ME WITH A MORE ORGANIZED QUASI-LINEAR MCS OVER SRN QUEBEC MOVING 305/40-50 KTS. 00Z ALB SOUNDING INDICATES THAT AIR MASS STREAMING INTO WRN NEW ENGLAND IN WAKE OF WARM FRONT IS MODERATE TO STRONGLY UNSTABLE WITH MLCAPES OF 2000-3500 J/KG...WHICH SHOULD MAINTAIN SRN QUEBEC MCS SEWD THROUGH PORTIONS OF NRN/CNTRL NEW ENGLAND OVERNIGHT. VERTICAL SHEAR PROFILES ARE FORECAST TO REMAIN QUITE SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES WITH CORRIDORS OF DAMAGING WINDS APPEARING LIKELY IN ADDITION TO SOME LARGE HAIL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1696. ..MEAD.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 05:45:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 01:45:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 020545 SWODY1 SPC AC 020543 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT WED AUG 02 2006 VALID 021200Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS NEWD THROUGH THE GREAT LAKES AND INTO MUCH OF NEW ENGLAND... ...SYNOPSIS... QUASI-ZONAL FLOW REGIME WILL PERSIST OVER THE NRN TIER OF STATES DURING THE DAY ONE PERIOD WITH SEVERAL SHORT WAVE TROUGHS EMBEDDED WITHIN THIS PATTERN. ONE SUCH IMPULSE WILL TRANSLATE EWD FROM WI THROUGH THE U.P./NRN LOWER MI INTO SRN QUEBEC BY LATE TONIGHT. MEANWHILE...MID-LEVEL SHEAR AXIS OVER THE CNTRL/SRN HIGH PLAINS WILL SLOWLY SHIFT EWD ACROSS KS TODAY AND TONIGHT. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO GREAT LAKES IMPULSE WILL DEVELOP EWD FROM CNTRL WI TO ERN LAKE HURON ALONG BAROCLINIC ZONE EXTENDING EWD THROUGH NRN NEW ENGLAND. IN THE WAKE OF THIS LOW...TRAILING COLD FRONT WILL SLOWLY SAG SWD THROUGH THE MID/LOWER MO VALLEY TO SECONDARY LOW PRESSURE OVER CNTRL/ERN KS. ...GREAT LAKES REGION INTO NEW ENGLAND... CLUSTERS OF NOCTURNAL TSTMS ARE EXPECTED TO BE IN PROGRESS AT THE ONSET OF THE PERIOD FROM VICINITY OF SURFACE LOW EWD ALONG LOW-LEVEL WAA ZONE FROM ERN MN INTO THE U.P. AND PARTS OF LOWER MI. THIS ACTIVITY WILL LIKELY CONTINUE THROUGH THE DAY...MAINLY N OF FRONTAL ZONE WITH ADDITIONAL...MORE DIURNAL STORM DEVELOPMENT LIKELY BY AFTERNOON WITHIN DESTABILIZING AIR MASS TO THE S FROM PARTS OF SRN WI EWD ACROSS CNTRL/SRN LOWER MI. HERE...MOIST BOUNDARY LAYER CONDITIONS COUPLED WITH DAYTIME HEATING WILL CONTRIBUTE TO MODERATE INSTABILITY WITH MLCAPES INCREASING TO 1500-2500 J/KG. LARGELY UNIDIRECTIONAL WIND PROFILES WITH 30-40 KTS OF DEEP SHEAR WILL BE SUPPORTIVE OF BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND SOME HAIL. FARTHER TO THE E OVER NEW ENGLAND...ADDITIONAL CLUSTERS OF STORMS WILL BE POSSIBLE TODAY AND TONIGHT...BOTH IN INTENSIFYING LOW-LEVEL WAA REGIME AHEAD OF SURFACE LOW...AS WELL AS WITH APPROACH OF SURFACE LOW LATE IN THE PERIOD. HERE TOO...KINEMATIC ENVIRONMENT IS CHARACTERIZED BY DEEP WLY TROPOSPHERIC FLOW WITH 35-45 KTS OF DEEP SHEAR...SUPPORTIVE OF ORGANIZED STORM STRUCTURES INCLUDING BOWS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. ...MIDWEST INTO KS... ADDITIONAL CLUSTERS OF STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON INTO EVENING ALONG COLD FRONT FROM NRN IL/SRN IA WWD INTO KS. STRONG DAYTIME HEATING AND RESULTANT STEEPING OF LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO THE DEVELOPMENT OF A MODERATELY UNSTABLE PRE-FRONTAL AIR MASS WITH MLCAPES OF 1000-2500 J/KG. FORCING WILL REMAIN RELATIVELY WEAK OVER THE MIDWEST...POTENTIALLY LIMITING STORM COVERAGE. HOWEVER FARTHER TO THE W OVER KS...FORCING FOR ASCENT ASSOCIATED WITH APPROACHING SHEAR AXIS WILL LIKELY SUPPORT MORE WIDESPREAD STORM COVERAGE. WHILE SLIGHTLY GREATER LOW-LEVEL HODOGRAPH CURVATURE IS FORECAST AHEAD OF SECONDARY SURFACE LOW ACROSS ERN KS INTO NWRN MO...DEEP-LAYER SHEAR WILL REMAIN QUITE MARGINAL /AOB 25-30 KTS/. THUS EXPECT THAT STORMS WILL REMAIN LARGELY MULTICELLULAR WITH THE PRIMARY THREATS BEING DAMAGING WINDS AND PERHAPS SOME HAIL. ..MEAD/JEWELL.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 12:57:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 08:57:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021257 SWODY1 SPC AC 021256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED AUG 02 2006 VALID 021300Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLNS THROUGH THE MID MS VLY/GRT LKS TO NRN NEW ENGLAND... ...SYNOPSIS... SEASONABLY STRONG ZONAL FLOW WILL PREVAIL OVER THE NRN THIRD OF THE NATION AS SEVERAL SHORT WAVE IMPULSES TEMPORARILY FLATTEN WRN FLANK OF BERMUDA RIDGE. ONE OF THESE DISTURBANCES...NOW OVER WI...WILL MOVE E ACROSS NRN MI INTO SRN QUEBEC BY LATE TONIGHT. FARTHER SE...MID-LEVEL SHEAR AXIS OVER THE CNTRL/SRN HIGH PLAINS EXPECTED TO SHIFT SLOWLY E ACROSS KS THROUGH TONIGHT. SURFACE LOW ACCOMPANYING GRT LKS IMPULSE WILL TRACK E ACROSS NRN MI AND SRN ONTARIO LATER TODAY/TONIGHT AS TRAILING COLD FRONT SETTLES SLOWLY SE ACROSS THE MID MS VLY AND CNTRL PLNS. E OF THE LOW...A FRONT SHOULD REMAIN MORE OR LESS STATIONARY EWD INTO NRN NEW ENGLAND. ...UPR GRT LKS TO NRN NEW ENGLAND... SEVERAL CLUSTERS OF STORMS EXPECTED TO MOVE/DEVELOP E ALONG STALLED FRONTAL ZONE FROM WI/NRN MI E ACROSS SRN ONTARIO/UPSTATE NY INTO NRN ENGLAND TODAY THROUGH TONIGHT. MUCH OF THE ACTIVITY MAY REMAIN SLIGHTLY ELEVATED ALONG AND N OF FRONT. BUT SURFACE HEATING SHOULD SUPPORT SURFACE-BASED STORM DEVELOPMENT FROM SRN/CNTRL WI E ACROSS CNTRL/SRN LOWER MI...AND POSSIBLY OVER UPSTATE NY/NWRN NEW ENGLAND BY EARLY AFTERNOON. RICH BOUNDARY LAYER MOISTURE /DEWPOINTS IN THE LOW 70S/ WILL COMPENSATE FOR RELATIVELY WARM MID LEVEL TEMPERATURES TO YIELD MLCAPE OF 1500-2500 J/KG. COUPLED WITH DEEP...MODERATE TO STRONG /40+ KT/ UNIDIRECTIONAL CLOUD LAYER FLOW...SETUP SHOULD PROMOTE N/S BOWING SEGMENTS AND POSSIBLE EMBEDDED SUPERCELLS WITH DAMAGING WIND/MARGINALLY SEVERE HAIL. DEPENDING ON STORM-SCALE EVOLUTION ...FAIRLY CONCENTRATED WIND DAMAGE MAY AFFECT LWR MI AND PARTS OF WI/NRN IL TODAY. FARTHER E...A FINAL ROUND OF STORMS MAY AFFECT UPSTATE NY/NW NEW ENGLAND EARLY THURSDAY AS LLJ STRENGTHENS DOWNSTREAM FROM APPROACHING SURFACE WAVE. ...CNTRL PLNS TO MID MS VLY... SURFACE HEATING EXPECTED TO SUPPORT DEVELOPMENT OF ADDITIONAL STRONG TO SEVERE STORM CLUSTERS ALONG COLD FRONT/LEE TROUGH FROM THE TX/OK PANHANDLE REGION THROUGH PARTS OF KS AND NW MO INTO SRN IA/NRN IL. STEEP LOW-LEVEL LAPSE RATES WILL CONTRIBUTE TO MLCAPE OF 1500-2500 J/KG. FORCING FOR ASCENT...WHILE WEAKER THAN OVER THE GRT LKS...WILL BE ENHANCED BY SMALL SCALE DISTURBANCES WITHIN UPR LEVEL SHEAR AXIS. DEEP WIND PROFILES OVER REGION WILL BE LESS UNIDIRECTIONAL THAN OVER THE GREAT LKS/NORTHEAST...BUT OVERALL MAGNITUDES WILL BE RELATIVELY WEAK /AOB 25-30 KTS/. COUPLED WITH FAIRLY LARGE TEMPERATURE-DEWPOINT SPREADS AND LARGELY LINEAR FORCING FOR ASCENT...STORMS SHOULD FAIRLY QUICKLY ORGANIZE INTO BANDS/CLUSTERS. THE MAIN SEVERE THREAT SHOULD BE DAMAGING WIND...AND POSSIBLY MARGINALLY SEVERE HAIL. ..CORFIDI.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 16:20:28 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 12:20:28 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 021620 SWODY1 SPC AC 021618 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 AM CDT WED AUG 02 2006 VALID 021630Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS THRU THE MIDDLE MS VALLEY AND GREAT LAKES TO NEW ENGLAND... ...SYNOPSIS... WESTERLIES NOW PREVAIL FROM COAST TO COAST ACROSS NRN TIER OF CONUS WITH BROAD HIGH PRESSURE DOMINATING MUCH OF SRN U.S. BAND OF 40-50KT MID LEVEL WESTERLIES IN ADVANCE OF S/WV TROUGH NOW MOVING ACROSS NRN CENTRAL U.S. WILL TRANSLATE EWD ACROSS GREAT LAKES THIS AFTERNOON AND NERN U.S. TONIGHT. COLD FRONT FROM UPR MI EXTENDS SWWD THRU SERN NEB TO NERN NM. FRONT WILL CONTINUE EWD ACROSS GREAT LAKES AND BY LATER TONIGHT REACH FROM NRN NY BACK TO VICINITY OK/KS BORDER. WARM...MOIST AND POTENTIALLY VERY UNSTABLE AIR REMAINS S AND E OF FRONTAL ZONE PARTICULARLY MS VALLEY EWD. ...GREAT LAKES TO NERN U.S... STRONG HEATING MOST AREAS TO S OF COLD FRONT WHERE DEWPOINTS GENERALLY 70F OR GREATER WILL GENERATE A VERY UNSTABLE AIR MASS WITH MLCAPES RANGING UPWARDS TO 2500 J/KG MANY AREAS. PRIMARY FOCUS FOR SEVERE THUNDERSTORM INITIATION THIS AFTERNOON WILL BE THE FRONTAL CONVERGENCE. BY MID AFTERNOON SEVERE THUNDERSTORMS EXPECTED TO BE INCREASING IN NUMBER AND INTENSITY FROM WI EWD ACROSS LOWER MI THRU UPSTATE NY AND WRN NEW ENGLAND. WITH 30-40KT OF DEEP LAYER SHEAR...STORMS SHOULD EVOLVE INTO SHORT LINES/BOW IN THE STRONG FLOW WITH ACCOMPANYING WIND DAMAGE POTENTIAL. LARGE HAIL THREAT WILL BE SOMEWHAT MITIGATED BY THE WARM LAPSE RATES. SUFFICIENT SHEAR GIVEN LARGE AMOUNT OF INSTABILITY FOR SUPERCELL POTENTIAL. THIS WOULD RESULT IN AN ENHANCED SEVERE THREAT ALONG WITH ISOLATED TORNADOES. ONE OF MORE FORWARD PROPAGATING MCS'S LIKELY DEVELOPING THIS EVENING WHICH ALSO WOULD INCREASE WIND DAMAGE THREAT. ...MID MS VALLEY SWWD TO CENTRAL/SRN HIGH PLAINS... DEEP LAYER SHEAR WILL RANGE DOWNWARD ALONG FRONTAL ZONE FROM 25-30KT IA AREA TO LESS THAN 20KT HIGH PLAINS. HOWEVER THE STRONG HEATING WILL DEVELOP STEEP LOW/MID LAPSE RATES AHEAD OF FRONT ALONG WITH MLCAPES CLIMBING TO AS HIGH AS 2000 J/KG. THUNDERSTORMS WILL ALSO DEVELOP IN RESPONSE TO FRONTAL CONVERGENCE BY MID/LATE AFTERNOON. CONVECTIVE MODE SHOULD BE MORE MULTI-CELLULAR WITH ISOLATED SUPERCELLS POSSIBLE. DAMAGING WINDS AND LARGE HAIL WOULD BE LIKELY...PARTICULARLY IN KS PORTION WHERE CAPE/SHEAR COMBINATION APPEARS TO BE MORE FAVORABLE. ..HALES/CROSBIE.. 08/02/2006  From swody1 at goshenarc.org Wed Aug 2 20:05:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 16:05:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 022005 SWODY1 SPC AC 022003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT WED AUG 02 2006 VALID 022000Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NERN U.S. AND GREAT LAKES INTO THE CENTRAL PLAINS.... ...SYNOPSIS... LATEST SFC MESOANALYSIS SHOWS COLD FRONTAL BOUNDARY THAT EXTENDS FROM SWRN QUEBEC SWWD THRU SERN ONTARIO TO A LOW OVER EXTREME ERN UPR MI/NRN LWR MI. A FRONTAL BOUNDARY CONTINUES FROM THE LOW THRU CENTRAL WI. THESE BOUNDARIES ARE AHEAD OF POSITIVELY TILTED MID/UPR LEVEL SHORTWAVE TROUGH THAT EXTENDS FROM NERN MN SWWD INTO NERN NEB. THIS TROUGH IS EXPECTED TO CONTINUE EWD INTO WI/IA BY 03/12Z. ...PARTS OF THE NORTHEAST FROM CENTRAL NEW ENGLAND INTO NEW YORK STATE... AIR MASS IS ABNORMALLY HOT AND MOIST WITH TEMPERATURES GENERALLY IN THE 90S AND DEW POINTS IN THE MID/UPR 70S FROM NEW YORK INTO SRN ME AND COASTAL MA. NUMEROUS STRONG/SEVERE STORMS ARE TRACKING EWD ACROSS PARTS OF VT/NH AND CENTRAL NY STATE. MLCAPE VALUES ARE 2000-2500 J/KG FROM ERN LE REGION THRU SRN NEW ENGLAND. RUC MODEL SOUNDINGS SHOW THAT LAPSE RATES ARE BETWEEN 6.0 AND 6.5C/KM...BUT THE DATA ALSO SHOWS A FAIR AMOUNT OF DRYING ABOVE 720 MB WHICH WOULD INDICATE THAT THE MAIN THREAT WILL BE DAMAGING WINDS AND HAIL. ...GREAT LAKES REGION... COLD FRONT EXTENDS FROM EXTREME N CENTRAL LOWER MI SWWD THRU GRB AND RST AND WILL CONTINUE SEWD AND SWD ACROSS THESE REGIONS. STORMS ARE DEVELOPING/RAPIDLY INTENSIFYING WITHIN STRONG INSTABILITY GRADIENT WHERE MLCAPE RANGES FROM 1000-3000 J/KG. RUC MODEL SOUNDING AT OSH SHOWS MID LEVEL DRY AIR PRESENT WITH MID LEVEL LAPSE RATES NEAR 7C/KM. THIS WOULD INDICATE AGAIN THE THREAT FOR DAMAGING WINDS...BUT SOME LARGE HAIL MAY OCCUR WITH THE STEEP MID LEVEL LAPSE RATES THRU THIS AFTERNOON. ...IA SWWD INTO KS... WARM AIR MASS WITH DEW POINTS MAINLY FROM THE MID 60S TO LOWER 70S IS PRESENT THRU THIS AREA. WEAK FRONT/SURFACE TROUGH EXTENDS FROM NERN IA INTO SWRN KS. LOOKS LIKE MAINLY MID LEVEL BASED TYPE THUNDERSTORMS WILL DEVELOP ALONG THE SURFACE TROUGH AS EFFECTIVE CAPE VALUES ARE RANGING BETWEEN 1500-2000 J/KG. THIS ENVIRONMENT IS FAVORABLE FOR DOWNBURST WINDS WITH STEEP LAPSE RATES IN THE LOWEST 3KM OF 8.5C/KM. ..MCCARTHY.. 08/02/2006  From swody1 at goshenarc.org Thu Aug 3 00:54:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 02 Aug 2006 20:54:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030054 SWODY1 SPC AC 030053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT WED AUG 02 2006 VALID 030100Z - 031200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE GREAT LAKES/MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF UPSTATE NY AND WRN NEW ENGLAND... ...SYNOPSIS... EXTENSIVE FRONTAL ZONE LIES ALONG THE NWRN/NRN PERIPHERY OF DEEP LAYER SUBTROPICAL RIDGE FROM THE SRN HIGH PLAINS...NEWD ACROSS THE UPPER MIDWEST...AND THEN EWD FROM SRN ONTARIO TO NRN NEW ENGLAND. PACKETS OF STRONGER MID LEVEL FLOW...ASSOCIATED WITH IMPULSES EMBEDDED WITHIN THE WLYS...WERE AIDING SURFACE CONVERGENCE/LIFT AND TSTM DEVELOPMENT ALONG SEGMENTS OF THE FRONT FROM KS TO MI TO SRN ONTARIO. GREATEST POTENTIAL FOR STORM ORGANIZATION AND PERSISTENCE OVERNIGHT WILL OCCUR OVER THREE REGIONS. FROM WEST-TO-EAST THESE REGIONS ARE...THE MO RIVER VALLEY...IL/MI... AND UPSTATE NY/WRN NEW ENGLAND. ...KS/MO/EXTREME SERN NEB AND SRN IA... WELL ORGANIZED MESOSCALE STORM COMPLEX ACROSS KS HAS PRODUCED A LARGE COLD POOL. RESULTANT OUTFLOW SHOULD CONTINUE TO SPAWN SCATTERED TSTM DEVELOPMENT WITH SOME THREAT FOR DAMAGING DOWNBURSTS IN HOT/WELL-MIXED AND MODERATELY UNSTABLE AIR MASS FROM ERN KS EWD INTO MO. GREATER POTENTIAL FOR PERSISTENT MESOSCALE ORGANIZATION... AND PERHAPS A MORE CONCENTRATED SEVERE THREAT...MAY EVOLVE FROM FRONTAL WAVE MOVING ACROSS EXTREME NEB AND INTO VERY MOIST AND UNSTABLE AIR MASS ALONG THE FRONT FROM SRN IA/NRN MO TO THE MS RIVER THROUGH LATE TONIGHT. ...IL/MI... SEVERAL BANDS OF DEEP CONVECTION PRECEDE THE SURFACE FRONT SITUATED FROM SRN WI ENEWD ACROSS LOWER MI THIS EVENING. MOST INTENSE STORMS WERE NOW DEVELOPING INTO AN AXIS OF LOCALLY EXTREME INSTABILITY FROM CHICAGO ACROSS SRN LAKE MI...AND INTO SWRN MI. SOMEWHAT LIMITED DEEP SHEAR EXIST OVER THIS REGION BASED ON LATEST SOUNDINGS FROM ILX AND DTX. HOWEVER...LARGE SCALE LIFT AND DEGREE OF INSTABILITY WILL LIKELY PROVE SUFFICIENT TO MAINTAIN A THREAT DAMAGING WINDS AS CONVECTION PERSISTS AND DEVELOPS GRADUALLY EWD THROUGH LATE TONIGHT. ...NY/VT... PER COORDINATION WITH ENVIRONMENT CANADA AND REVIEW OF OBSERVATIONAL DATA FROM SRN/SWRN ONTARIO...WIDESPREAD SEVERE WIND WAS ACCOMPANYING STORMS NORTH OF LAKES ERIE AND ONTARIO THIS EVENING. THIS LINEAR MCS WAS BEING DRIVEN BY A WELL-DEFINED SHORT WAVE TROUGH...STRONG LOW LEVEL WARM AIR ADVECTION...AND VERY UNSTABLE BOUNDARY LAYER AIR MASS FEEDING INTO THE REGION FROM THE MIDWEST. STRONG DYNAMIC FORCING ASSOCIATED WITH FRONTAL WAVE AND WARM AIR/MOISTURE ADVECTION WITH THIS SYSTEM WILL MOVE ACROSS THE LAKES AND INTO NY AND PARTS OF NEW ENGLAND THROUGH LATE TONIGHT. EVENING SOUNDINGS FROM BUF AND ALY DEPICTED RELATIVELY STEEP LOW LEVEL LAPSE RATES AND ABUNDANT MOISTURE WITH MORE THAN ADEQUATE SHEAR TO SUSTAIN SEVERE STORMS. OVERALL PATTERN APPEARS TO FAVOR THE MAINTENANCE OF A SEVERE MCS WITH POTENTIAL FOR NUMEROUS DAMAGING WIND EVENTS MOVING ACROSS UPSTATE NY AND PARTS OF VT INTO LATE TONIGHT/EARLY THURSDAY. ..CARBIN.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 04:55:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 00:55:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 030455 SWODY1 SPC AC 030453 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1153 PM CDT WED AUG 02 2006 VALID 031200Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST/OH VALLEY TO SRN NEW ENGLAND... ...SYNOPSIS... SUBTROPICAL RIDGE AXIS WILL CONTINUE TO PRODUCE TYPICALLY HOT AND HUMID SUMMERTIME CONDITIONS FROM THE SRN ROCKIES AND PLAINS EWD/NEWD ACROSS MUCH OF THE MS VALLEY...SOUTH...AND MOST OF THE EAST COAST TODAY. A RESPITE FROM THE HEAT WILL COME ALONG WITH THE CHANCE FOR ISOLATED TO SCATTERED SEVERE STORMS DURING THE AFTERNOON AND EVENING FROM PARTS OF THE SRN ROCKIES/PLAINS EAST TO THE MIDWEST/OH VALLEY AREAS...AND OVER PA/NY/NJ...AND PORTIONS OF SRN NEW ENGLAND. ADDITIONAL SCATTERED AFTERNOON AND EARLY EVENING PULSE/MULTICELL STORMS COULD PRODUCE ISOLATED DAMAGING WIND GUSTS AND HAIL FROM THE SRN APPALACHIANS TO THE NERN GULF COAST AND FL. ...MIDWEST TO SRN NEW ENGLAND... DEEP-LAYER FRONTAL ZONE REINFORCED BY SEVERAL ONGOING CONVECTIVE COMPLEXES WILL REMAIN SITUATED ALONG THE SRN EDGE OF FASTER MID LEVEL FLOW OF 30-40KT FROM THE MID MS VALLEY EWD TO NY/CT. VERY UNSTABLE CONDITIONS SHOULD DEVELOP WITH HEATING OF THE DAY ALONG AND SOUTH OF THE FRONT WITH MLCAPE OVER 2000 J/KG LIKELY. LARGE SCALE FORCING ASSOCIATED WITH MID LEVEL HEIGHT FALLS AND FRONTAL LIFT WILL SPUR ADDITIONAL CONVECTION WITH STORMS INTENSIFYING AS GREATER INSTABILITY IS REALIZED. ACTIVITY SHOULD FORM INTO SEVERAL PERSISTENT ESEWD-MOVING BANDS OR CLUSTERS WITH WIND DAMAGE BEING THE PREDOMINANT SEVERE WEATHER HAZARD. ...SRN ROCKIES/PLAINS... FARTHER WEST...LARGE SCALE FORCING AND SHEAR WILL BE WEAKER. HOWEVER...TRAILING FRONT AND STRONG HEATING WILL PROVIDE SOME IMPETUS FOR AT LEAST ISOLATED STRONG TO SEVERE STORM DEVELOPMENT FROM THE OZARKS WSWWD ACROSS OK/NRN TX AND NM BY AFTERNOON. WELL MIXED BOUNDARY LAYER AND LARGE SURFACE TEMP/DEWPOINT DEPRESSIONS WILL LEAD TO THE POTENTIAL FOR DAMAGING DOWNBURST WINDS FROM PULSE STORMS DURING THE LATE AFTERNOON. A WEAK IMPULSE ROTATING AROUND THE WRN/NWRN PERIPHERY OF SUB-TROPICAL RIDGE...COUPLED WITH WEAK LOW LEVEL UPSLOPE FLOW AND DIFFERENTIAL HEATING...MAY PROMOTE A FEW TSTM CLUSTERS FROM NERN NM NWD/NEWD ALONG THE FRONT RANGE AND INTO THE CENTRAL HIGH PLAINS. SOME OF THIS CONVECTION MAY PERSIST PAST SUNSET AS LOW LEVEL JET INTENSIFIES AND SUSTAINS MASS TRANSPORT INTO THE CENTRAL HIGH PLAINS AREA. GENERALLY LIMITED MOISTURE AND WEAK FORCING SHOULD KEEP SEVERE WEATHER ISOLATED TO MARGINAL HAIL...AND PERHAPS A COUPLE OF SEVERE WIND GUSTS. ANOTHER DISTURBANCE OF SUB-TROPICAL ORIGIN IS FORECAST TO SPREAD NWWD FROM NRN MEXICO TO NEAR THE AZ/NM BORDER AREA. THIS SYSTEM COULD ENHANCE TSTM COVERAGE AND PERSISTENCE FROM WEST TX WWD TO SERN AZ WITH ISOLATED STRONG TO SEVERE WIND GUSTS AND HAIL POSSIBLE...ALONG WITH HEAVY RAIN. ...SOUTHEAST/FL... STRONG HEATING AND WEAK CAP WILL CONTRIBUTE TO THE DEVELOPMENT OF AFTERNOON STORMS ACROSS THE SOUTHEAST AND FL. STORMS ACROSS THE SOUTHEAST WILL LIKELY FORM ON THE ERN SLOPES OF THE APPALACHIANS AND ALSO NEAR SEA BREEZE BOUNDARIES NEAR THE COAST. WEAK SHEAR AND FORCING WITHIN DEEP-LAYER ANTICYCLONE WILL CONFINE SEVERE WEATHER POTENTIAL TO ISOLATED/RANDOM PULSE STORMS ACCOMPANIED BY STRONG WIND GUSTS. SLIGHTLY GREATER CONCENTRATION OF STORMS WITH WIND AND HAIL POTENTIAL MAY FORM ACROSS PORTIONS OF FL AS A MID LEVEL IMPULSE AND ASSOCIATED MID LEVEL COLD POOL DRIFT WWD COINCIDENT WITH STRONGEST DIURNAL DESTABILIZATION. ..CARBIN/JEWELL.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 13:01:40 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 09:01:40 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031301 SWODY1 SPC AC 031259 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0759 AM CDT THU AUG 03 2006 VALID 031300Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR OH VLY INTO SRN NEW ENGLAND... ...SYNOPSIS... LOW AMPLITUDE SHORTWAVE TROUGH NOW OVER THE MID/UPR MS VLY WILL TRACK E TO LK HURON BY THIS EVENING BEFORE CONTINUING E INTO UPSTATE NY FRIDAY MORNING. MODERATE TO STRONG ZONAL FLOW ASSOCIATED WITH THIS FEATURE WILL PREVAIL FROM THE N CNTRL STATES TO THE N AND MID ATLANTIC CST. ELSEWHERE...REMNANT DEFORMATION AXIS WITH EMBEDDED DISTURBANCES EXPECTED TO PERSIST FROM THE SRN HI PLNS E/NE INTO SRN KS AND MO. FARTHER S...SUBTROPICAL IMPULSES SHOULD CONTINUE SLOWLY W ACROSS THE BAHAMAS/FL...AND ACROSS S TX. AT THE SURFACE...DIFFUSE W/E COLD FRONT LOCALLY REINFORCED BY CONVECTIVE OUTFLOW WILL SETTLE S ACROSS THE ERN GRT LKS AND OH VLY. A SHALLOW COOL SURGE WILL ALSO MOVE SW INTO CNTRL NEW ENGLAND. ...OH VLY INTO SRN NEW ENGLAND... DEEP UNIDIRECTIONAL WSWLY FLOW...WITH MEAN SPEEDS ON THE ORDER OF 40 KTS...WILL PREVAIL DOWNSTREAM FROM SHORTWAVE IMPULSE CROSSING THE GRT LKS. SURFACE HEATING SHOULD YIELD VERY UNSTABLE CONDITIONS ALONG/AHEAD OF COLD FRONT/OUTFLOW BOUNDARIES...WITH AVERAGE MLCAPE AOA 2000 J/KG LIKELY FROM PARTS OF IN/KY E/NE INTO SRN NEW ENGLAND AND PA/SRN NY. COMBINATION OF LARGE SCALE FORCING...FRONTAL UPLIFT AND DEEP UNIDIRECTIONAL FLOW SHOULD SUPPORT ADDITIONAL ROUNDS OF FORWARD-PROPAGATING CONVECTIVE SYSTEMS...WITH N/S-ORIENTED EMBEDDED BOWS PRODUCING WIND DAMAGE AND POSSIBLY MARGINALLY SEVERE HAIL THROUGH EARLY TONIGHT. ...SRN/CNTRL PLNS INTO THE RCKYS/SW... WEAK DEEP SHEAR/FORCING WILL PREVAIL INVOF STALLING COLD FRONT/LEE TROUGH OVER THE SRN PLNS. STRONG HEATING...SHALLOW FRONTAL CONVERGENCE AND UPSLOPE COMPONENTS WILL...HOWEVER...PROVIDE SUPPORT FOR ISOLATED TO WIDELY SCATTERED STRONG TO SEVERE PULSE STORMS FROM THE OZARKS WSW ACROSS OK/NRN TX AND ERN NM BY AFTERNOON. DEEPLY MIXED BOUNDARY LAYER WITH LARGE SURFACE TEMP/DEWPOINT SPREADS MAY PROMOTE A FEW MICROBURSTS THIS AFTERNOON AND EARLY EVENING. FARTHER W...WEAK IMPULSE MOVING W ACROSS S TX...COUPLED WITH WEAK UPSLOPE FLOW AND DIFFERENTIAL HEATING...MAY SUPPORT A FEW PERSISTENT TSTM CLUSTERS FROM NERN NM NWD/NEWD ALONG THE FRONT RANGE AND INTO THE CENTRAL HIGH PLAINS. SOME OF THIS ACTIVITY CONVECTION MAY PERSIST PAST SUNSET AND SPREAD INTO SD/SRN ND LATE TONIGHT AS LLJ INTENSIFIES. SUFFICIENT INSTABILITY MAY DEVELOP TO SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL AND WIND. ANOTHER DISTURBANCE OF SUB-TROPICAL ORIGIN WILL MOVE NW FROM NRN MEXICO TO NEAR THE AZ/NM BORDER AREA. THIS SYSTEM COULD ENHANCE TSTM COVERAGE/PERSISTENCE FROM W TX INTO SE AZ...WITH ISOLATED STRONG TO SEVERE WIND GUSTS AND HAIL POSSIBLE...ALONG WITH HEAVY RAIN. ...FL PENINSULA... WWD-MOVING UPR DISTURBANCE WILL STEEPEN MID LEVEL LAPSE RATES AND ENHANCE LARGE SCALE ASCENT ACROSS FL PENINSULA DURING MAX HEATING TODAY. THIS MAY SUPPORT STRONGER/MORE PERSISTENT AND ORGANIZED DIURNAL STORM CLUSTERS RELATIVE TO RECENT DAYS. PARTS OF THE SRN/CNTRL PENINSULA MAY REQUIRE UPGRADE TO SLIGHT RISK IF STORM SCALE INTERACTIONS ARE ABLE TO TAKE ADVANTAGE OF INCREASING INSTABILITY. ..CORFIDI/JEWELL.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 16:34:00 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 12:34:00 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 031633 SWODY1 SPC AC 031632 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1132 AM CDT THU AUG 03 2006 VALID 031630Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS OHIO VALLEY TO SRN NEW ENGLAND... ...SYNOPSIS... ZONAL FLOW CONTINUES ACROSS NRN CONUS WITH A BROAD UPPER RIDGE S OF 40N. PRIMARY FRONTAL ZONE CONTINUES TO MOVE SLOWLY S AND E AND THIS MORNING EXTENDS FROM SWRN ONTARIO THRU NRN IL AND THEN SWWD ACROSS NRN OK INTO TX PANHANDLE. A VERY WARM AND MOIST AIR MASS REMAINS TO S OF FRONTAL ZONE FROM SRN NEW ENGLAND TO SRN PLAINS. FOCUS FOR INITIATION OF STRONG/SEVERE THUNDERSTORMS WILL BE PRIMARILY VICINITY THE SRN FRINGE OF THICKER BAND OF CLOUDS THAT EXTENDS FROM SRN NEW ENGLAND ACROSS NY INTO NRN OH VALLEY. ...OH VALLEY TO SRN NEW ENGLAND... AS TEMPERATURES RISE THRU THE 90S WITH DEWPOINTS AOA 70F...AIR MASS IS BECOMING VERY UNSTABLE WITH MLCAPES INCREASING TO 2000-3000 J/KG. 30-35 KT OF SHEAR COMMON AHEAD OF WEAK TROUGH NOW MOVING EWD THRU THE GREAT LAKES. CLUSTERS OF THUNDERSTORMS HAVE ALREADY DEVELOPED NERN OH AND CENTRAL IND THIS AM. WITH THE STRONG HEATING...STRONG/SEVERE THUNDERSTORMS WILL BE INCREASING EWD ACROSS OH VALLEY INTO SRN NEW ENGLAND THRU THE AFTERNOON. WIND DAMAGE WILL BE GREATEST CONCERN PARTICULARLY ASSOCIATED WITH DEVELOPMENT OF SHORT LINES/BOWS GIVEN THE FAVORABLE SHEAR...STEEP LOW LEVEL LAPSE RATES AND HIGH PW/S. HAIL WILL BE LESS LIKELY WITH THE WARM MID LEVEL LAPSE RATES. ...CAROLINAS... WITH VERY STRONG HEATING...AND HIGH SURFACE DEWPOINTS....CONDITIONS ARE FAVORABLE FOR STRONG/ISOLATED SEVERE STORMS TO DEVELOP E OF APPALACHIANS THIS AFTERNOON AND EVENING. WHILE SHEAR IS WEAK...DCAPES FORECASTED TO BE IN EXCESS OF 1500 J/KG AND STEEP LOW LEVEL LAPSE RATES SUPPORT POTENTIAL FOR PULSE SEVERE IN FORM OF DOWNBURSTS FROM MID AFTERNOON UNTIL SUNSET. ...SRN FL... WEAK MID/UPPER LEVEL CYCLONIC SYSTEM OFF E COAST OF FL WILL PROVIDE BOTH SOME INCREASE IN SHEAR AND LAPSE RATES TO ENHANCE THE DIURNAL THUNDERSTORM CYCLE. ISOLATED DOWNBURSTS AND MARGINAL HAIL WILL BE POSSIBLE WITH STRONGEST STORMS S HALF OF FL. ...SRN ROCKIES/CENTRAL SRN HIGH PLAINS EWD ACROSS OK INTO SRN MO... BOUNDARIES HAVE MOVED SWD TO STRETCH ACROSS SRN MO INTO SWRN OK THEN WWD. EXAMINING 12Z SOUNDINGS...THE MODERATELY UNSTABLE AIR MASS WILL SUPPORT THUNDERSTORMS DEVELOPING BY MID/LATE AFTERNOON VICINITY BOUNDARIES AS MLCAPES CLIMB TO ABOVE 2000 J/KG AND DCAPES ALSO INCREASE TO AOA 1500 J/KG. WITH WEAK DEEP LAYER SHEAR...STORM MODE SHOULD BE PRIMARILY PULSE SRN PLAINS AND POSSIBLY MULTICELL ERN CO INTO WRN NEB/SD WHERE SHEAR IS A LITTLE GREATER. DOWNBURSTS AND ISOLATED HAIL WILL BE POSSIBLE MUCH OF THIS AREA BUT LACK OF ORGANIZATION PRECLUDES A RISK AREA. ..HALES/CROSBIE.. 08/03/2006  From swody1 at goshenarc.org Thu Aug 3 20:04:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 16:04:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 032003 SWODY1 SPC AC 032001 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0301 PM CDT THU AUG 03 2006 VALID 032000Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE NORTHEAST INTO THE LOWER OHIO VALLEY.... ...SYNOPSIS... MID/UPPER LEVEL SHORTWAVE TROUGH IS MOVING EWD INTO THE ERN GREAT LAKES AND EXTENDING SWWD INTO THE MID MS VALLEY. LATEST SURFACE ANALYSIS SHOWS A COLD FRONT FROM WRN LAKE ERIE WSWWD THRU CENTRAL MO INTO SERN KS...WITH SEVERAL CONVECTIVE BOUNDARIES ACROSS NE INTO CENTRAL OHIO...THRU CENTRAL NY STATE INTO NERN OH...AND FROM NERN PA ENEWD THRU COASTAL MA. THE BOUNDARIES WILL REMAIN THE FOCUS FOR FURTHER CONVECTION THRU EARLY TONIGHT. ...INDIANA/OHIO ENEWD INTO SRN NEW ENGLAND... STRONG/SEVERE THUNDERSTORMS EXTENDS ALONG THE BOUNDARY FROM S CENTRAL NY STATE THRU NRN/CENTRAL OH AND CENTRAL INDIANA. ALONG AND S OF THE BOUNDARY...AIR MASS IS MODERATELY UNSTABLE WITH MLCAPE BETWEEN 1500-2500 J/KG DUE TO DAYTIME HEATING AND SURFACE DEW POINTS IN THE UPR 60S TO LOW 70S. MAIN THREAT WITH ALL THIS ACTIVITY WILL BE DAMAGING WINDS RAIN-COOLED AIR BEHIND THE LINES OF CONVECTION ACCELERATE THE STORMS EWD INTO UNSTABLE AIR. IN ADDITION...ISOLATED STRONG STORMS ARE DEVELOPING OVER SERN LOWER MI INTO E CENTRAL IL AHEAD OF 850 MB FRONT AND JUST BEHIND SURFACE FRONT. THESE STORMS ARE EXPECTED TO BECOME STRONG THRU EARLY TONIGHT AND POSSIBLY PRODUCE SOME STRONG GUSTY WINDS. ...SERN U.S. FROM VA/NC INTO AL/GA... PULSE STORMS HAVE DEVELOPED IN VERY UNSTABLE AIR MASS WHERE MLCAPE IS GENERALLY BETWEEN 2000-3000 J/KG. ACTIVITY IS WITHIN REGIME OF WEAK LOW/UPPER LEVEL FLOW...THUS THE STORMS ARE DEVELOPING AND NOT MOVING VERY MUCH AND MERGING WITH SURROUNDING STORMS. SOME OF THIS ACTIVITY MAY PRODUCE LOCALIZED DAMAGING WINDS AS THEY COLLAPSE PUTTING OUT OUTFLOWS FOR NEWER STORMS TO DEVELOP THROUGH EARLY TONIGHT. ...PARTS OF THE SRN PLAINS INTO THE CENTRAL HIGH PLAINS... SEVERAL WEAK BOUNDARIES FROM PREVIOUS CONVECTION EXTENDS FROM S CENTRAL KS THRU NWRN OK...AND FROM NWRN AR INTO SWRN OK AND THE TX PANHANDLE. THIS AIR MASS TOO IS MODERATELY UNSTABLE WITH MLCAPE GENERALLY AROUND 2000 J/KG. UPSLOPE TYPE FLOW EXTENDS FROM THE TX PANHANDLE INTO ERN CO...THEN RETURN SLY FLOW IS CARRYING THIS MOISTURE INTO THE BLACK HILLS REGION OF SD. ONCE AGAIN...GIVEN THAT THE AIR MASS IS HOT AND MOIST WITH TEMPERATURES IN THE 90S IN THE PLAINS AND DEW POINTS IN THE 60S ACROSS SRN SECTIONS DOWN TO THE 50S IN ERN CO TO THE 40S IN SD...LAPSE RATES ARE FAVORABLE FOR STRONG STORMS WITH POSSIBLY STRONG GUSTY WINDS. ..MCCARTHY.. 08/03/2006  From swody1 at goshenarc.org Fri Aug 4 00:44:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 03 Aug 2006 20:44:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040040 SWODY1 SPC AC 040039 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0739 PM CDT THU AUG 03 2006 VALID 040100Z - 041200Z ...NO SVR TSTM AREAS FORECAST... ...STATIONARY FRONT FROM SRN PLAINS TO LONG ISLAND SOUND... A NARROW BUT EXTENSIVE AXIS OF PERSISTENT LOW LEVEL CONVERGENCE ASSOCIATED WITH NEARLY STALLED FRONTAL ZONE...COUPLED WITH REGIONS OF MODEST TO STRONG INSTABILITY...WILL CONTINUE TO SUPPORT SCATTERED STRONG TO ISOLATED SEVERE TSTMS TONIGHT. POCKETS OF ACTIVITY PERSIST FROM THE TX/OK PNHDLS EWD AND NEWD ACROSS THE OH VALLEY...AND FROM LAKE ERIE ACROSS PARTS OF CNTRL PA. GENERALLY WEAK LARGE SCALE SUPPORT FOR UPWARD MOTION...LIMITED DEEP LAYER SHEAR...AND GRADUAL BOUNDARY LAYER STABILIZATION WITH LOSS OF INSOLATION ALL POINT TOWARD A DIMINISHING RISK OF SEVERE WEATHER. THEREFORE...ONLY A LOW PROBABILITY FOR DAMAGING WINDS WILL BE MAINTAINED ALONG THE FRONTAL ZONE FOR THE REMAINDER OF TONIGHT. ..CARBIN.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 05:07:53 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 01:07:53 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 040508 SWODY1 SPC AC 040506 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1206 AM CDT FRI AUG 04 2006 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID ATLANTIC AND SOUTHEAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN PLAINS FROM ND/NRN MN TO WRN LAKE SUPERIOR... ...SYNOPSIS... MODERATE ZONAL FLOW WITH PROGRESSIVE LOW-AMPLITUDE PERTURBATIONS WILL PERSIST ACROSS THE NRN BORDER STATES THROUGH FRIDAY. AS A MID LEVEL TROUGH PASSES OFF THE ERN SEABOARD...ASSOCIATED DEEP-LAYER FRONTAL ZONE WILL SETTLE SEWD ACROSS THE CNTRL/SRN APPALACHIANS AND MERGE WITH LEE-TROUGH FROM VA SWWD ACROSS THE CAROLINAS TODAY. THE BOUNDARY WILL EXTEND WWD FROM THE TN VALLEY INTO THE SRN PLAINS BENEATH WEAK ANTICYCLONIC FLOW ALOFT. FROM THE NRN ROCKIES TO THE NRN PLAINS...A WEAK SHORT WAVE TROUGH WILL PRECEED A STRONGER SYSTEM DIGGING SEWD FROM NWRN CANADA. THIS LEAD IMPULSE WILL ENHANCE WARM AIR ADVECTION AND LIFT FROM THE DAKOTAS EWD ACROSS NRN MN THROUGH TONIGHT...WHILE THE STRONGER DISTURBANCE DRIVES A COLD FRONT SEWD INTO ERN MT AND WRN ND THROUGH EARLY SATURDAY. A COUPLE OF WEAK WAVES WILL TRAVEL ALONG THE SRN/SWRN PERIPHERY OF THE SUBTROPICAL RIDGE AXIS. ONE OF THESE WAVES WILL CONTINUE TO TRACK ACROSS FL AND THE NERN GULF COAST THROUGH TODAY. THE OTHER WAVE WILL MOVE SLOWLY NWD FROM MEXICO AND ACROSS THE NM/AZ BORDER AREA DURING THIS FORECAST PERIOD. ...SRN DELMARVA SWWD TO GA... VERY MOIST AIR MASS AND HEATING WILL CONTRIBUTE TO THE DEVELOPMENT OF STRONG INSTABILITY AGAIN TODAY FROM THE APPALACHIANS EWD TO THE COAST. TSTMS WILL AGAIN DEVELOP ACROSS THE HIGHER TERRAIN AND NEAR LEE-TROUGH IN ADVANCE OF DEEPER FRONTAL CIRCULATION SPREADING INTO THE REGION THROUGH EVENING. WHILE EFFECTIVE SHEAR WILL REMAIN MEAGER GIVEN NO MORE THAN 20KT MID LEVEL FLOW...LARGE SCALE MID LEVEL DEFORMATION AXIS ATOP ABUNDANT BOUNDARIES TO FOCUS CONVECTION SHOULD SUPPORT NUMEROUS PULSE AND MULTICELL STORMS. STEEP THETA-E LAPSE RATES/HIGH DCAPE INVOF LEE-TROUGH/FRONT AND SEA-BREEZE MERGERS WILL PROMOTE WET DOWNBURST POTENTIAL WITH ANTICIPATED STORM COVERAGE WARRANTING HIGHER SEVERE PROBABILITIES/SLGT RISK. ...NRN PLAINS TO WRN LAKE SUPERIOR... LEADING LOW AMPLITUDE IMPULSE AND WEAK HEIGHT FALLS WILL SPREAD EAST FROM MT/WRN DAKOTAS COINCIDENT WITH INTENSE SURFACE HEATING ACROSS THE NRN HIGH PLAINS. VERY STEEP LAPSE RATES ATOP DRY BOUNDARY LAYER WILL RESULT IN STRONG INHIBITION OVER MUCH OF THE REGION THROUGH THE DAY. HOWEVER...PERSISTENT ASCENT AND DESTABILIZATION WITHIN WARM CONVEYOR BELT FROM ERN ND ACROSS MN MAY PROMOTE HIGH-BASED/ELEVATED TSTM DEVELOPMENT ACROSS THESE AREAS THROUGH THE AFTERNOON. THIS ACTIVITY MAY CONTINUE TO SPREAD EAST ACROSS NRN MN THROUGH THE PERIOD AS WARM FRONT STRENGTHENS AHEAD OF THE STRONGER IMPULSE DIGGING SEWD FROM CANADA. PRIMARY HAZARD WILL BE LARGE HAIL GIVEN STEEP LAPSE RATES AND STRONG SHEAR. HOWEVER...ISOLATED DAMAGING WINDS COULD ALSO EVOLVE IF ELEVATED CONVECTION CAN PERSIST NEAR EDGE OF THE CAP AND THEN MOVE/BACKBUILD INTO HEATED AND DEEPLY MIXED AIR MASS FROM ERN SD ACROSS CNTRL MN DURING THE AFTERNOON AND EVENING. ...TN VALLEY TO SRN PLAINS... ISOLATED WET DOWNBURSTS COULD OCCUR AS HEATING AIDS PULSE STORM DEVELOPMENT ALONG RESIDUAL FRONTAL ZONE THESE AREAS. VERY WEAK SHEAR AND MEAGER LAPSE RATES INDICATE SEVERE THREAT SHOULD REMAIN LIMITED IN TIME AND SPACE. ...SOUTHWEST... WET DOWNBURST ACTIVITY MAY ALSO INCREASE AS SUBTROPICAL IMPULSE ENHANCES TSTM ACTIVITY ACROSS THE SOUTHWEST. HOWEVER...WARM LAPSE RATES AND LIMITED SHEAR SUGGEST ONLY AN ISOLATED THREAT OF DAMAGING WINDS...BUT INCREASING POTENTIAL FOR LOCALLY HEAVY RAIN. ..CARBIN/JEWELL.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 13:00:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 09:00:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041300 SWODY1 SPC AC 041258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT FRI AUG 04 2006 VALID 041300Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLNS/UPR MS VLY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID AND S ATLANTIC CST... ...SYNOPSIS... SUBTROPICAL RIDGE WILL RETROGRADE SLIGHTLY THIS PERIOD AS LOW AMPLITUDE IMPULSE CONTINUES E TO THE CANADIAN MARITIMES. FARTHER N AND W...STRONGER DISTURBANCES NOW OVER BC EXPECTED TO PHASE OVER THE CANADIAN RCKYS LATER TODAY...BEFORE CONTINUING E AS A FAIRLY POTENT SHORTWAVE TROUGH INTO CNTRL/SRN SASKATCHEWAN. TRAILING FRONT WITH ERN SYSTEM WILL SETTLE SE ACROSS THE MID ATLANTIC AND TN VLY TODAY...WHILE DOWNSTREAM FROM THE BC/AB DISTURBANCE...EXPECT LEE LOW AND ASSOCIATED FRONTAL SYSTEM TO INTENSIFY OVER THE NRN PLNS. ...NRN PLNS... WEAK IMPULSE PRECEDING BC/AB DISTURBANCE WILL ENHANCE WARM ADVECTION/JET ENTRANCE REGION ASCENT OVER NRN/ERN ND AND NRN MN TODAY. BOUNDARY LAYER MOISTURE OVER REGION WILL REMAIN LIMITED. BUT COUPLED WITH MID LEVEL STEEP LAPSE RATES AND MODERATE/ UNIDIRECTIONAL CLOUD LAYER WLY FLOW...SETUP SHOULD SUPPORT A PERSISTENT AREA OF ELEVATED STORMS/POSSIBLE WEAK SUPERCELLS WITH MARGINALLY SEVERE HAIL. AS THE BOUNDARY LAYER WARMS AND LOW LEVEL LAPSE RATES STEEPEN...THIS ACTIVITY COULD ALSO YIELD LOCALLY DAMAGING WIND. SOME OF THE STORMS COULD SPREAD E TO WRN LK SUPERIOR EARLY SATURDAY. FARTHER S...EML SHOULD KEEP DEVELOPING WARM SECTOR CAPPED UNTIL LATE IN THE DAY. BUT CONVERGENCE ALONG LEE TROUGH COULD PROMOTE DEVELOPMENT OF WIDELY SCATTERED HIGH-BASED STORMS FROM CNTRL ND SSW INTO NW NEB LATE THIS AFTERNOON...WHERE THERMODYNAMIC ENVIRONMENT COULD SUPPORT A FEW MICROBURSTS. ...SRN DELMARVA SW INTO GA/TN VLY... HEATING OF VERY MOIST AIR IN PLACE INVOF WEAKENING COLD FRONT AND LEE TROUGH FROM THE SRN DELMARVA REGION INTO GA WILL BOOST MUCAPE TO AOA 2500 J/KG. EFFECTIVE DEEP WLY SHEAR WILL BE RATHER WEAK ...RANGING FROM 20-25 KTS IN NRN PART OF SLIGHT AREA TO LESS THAN 10 KTS IN SC. SLIGHTLY STRONGER ELY SHEAR WILL EXIST FARTHER S ACROSS SRN GA AND N FL...ON N SIDE OF W-MOVING UPR DISTURBANCE. WITH RESIDUAL UPR LEVEL DEFORMATION AXIS AND TERRAIN-INDUCED CIRCULATIONS TO FOSTER STORM INITIATION...SETUP SHOULD SUPPORT NUMEROUS AFTERNOON PULSE/MULTICELL STORMS. STEEP THETA-E LAPSE RATES AND HIGH DCAPE WILL PROMOTE WET DOWNBURST POTENTIAL. MORE ISOLATED WET MICROBURST ACTIVITY COULD OCCUR WWD ALONG TRAILING FRONT INTO THE TN VLY. ...SRN/ERN ID... SATELLITE LOOPS SHOW AN UPR IMPULSE LIFTING N ACROSS ERN NV ATTM...DOWNSTREAM FROM OFFSHORE LOW. INCREASING MID LEVEL MOISTURE AND UPR LEVEL DIVERGENCE IN ASSOCIATED DEFORMATION ZONE WILL REACH SRN/ERN ID AFTER MAX HEATING TIME TODAY...WHERE ENVIRONMENT COULD SUPPORT A SMALL CLUSTER OR TWO OF STORMS WITH LOCALLY DAMAGING WIND. ...SOUTHWEST... A FEW WET DOWNBURSTS MAY ALSO OCCUR OVER PARTS OF THE SOUTHWEST AS SUBTROPICAL IMPULSE ENHANCES TSTM COVERAGE OVER REGION. BUT WARM THERMODYNAMIC PROFILES AND VERY WEAK SHEAR SUGGEST THAT MAIN THREAT WILL BE LOCALLY HEAVY RAIN. ..CORFIDI/JEWELL.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 16:30:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 12:30:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 041629 SWODY1 SPC AC 041628 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CDT FRI AUG 04 2006 VALID 041630Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS NE ND INTO NRN MN.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FROM ERN VA ACROSS THE CAROLINAS TO GA/FL.... ...FL PENINSULA THIS AFTERNOON... A MID LEVEL LOW OVER CENTRAL FL WILL MOVE SLOWLY WWD THROUGH THE PERIOD. THE 12Z SOUNDING FROM TBW REVEALS 6.5-7 C/KM LAPSE RATES THROUGH THE LOWER TO MIDDLE TROPOSPHERE...AND A 500 MB TEMPERATURE OF -9 TO -10 C IN ASSOCIATION WITH THIS MID LEVEL LOW. AFTERNOON TEMPERATURES NEAR 90 F AND DEWPOINTS IN THE LOW-MID 70S WILL SUPPORT MLCAPE VALUES AOA 3000 J/KG. THUNDERSTORMS WILL LIKELY DEVELOP BY EARLY AFTERNOON...AND THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING DAMAGING WINDS WITH WET MICROBURSTS AND MARGINALLY SEVERE HAIL. ...SE ATLANTIC STATES THIS AFTERNOON... A MID LEVEL DEFORMATION ZONE EXISTS INVOF THE SRN APPALACHIANS...BETWEEN THE SRN FRINGE OF THE WLYS OVER THE OH VALLEY...AND THE MID LEVEL LOW IN THE ELYS OVER FL. A SURFACE COLD FRONT IS MOVING SEWD ACROSS THE CENTRAL/SRN APPALACHIANS...AND A PRE-FRONTAL TROUGH EXTENDS ALONG THE SE ATLANTIC COASTAL PLAINS FROM VA TO SE GA. SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON ALONG BOTH SURFACE BOUNDARIES AND OVER THE HIGHER TERRAIN OF THE WRN CAROLINAS. THE STRONGER INSTABILITY IS EXPECTED OVER THE COASTAL PLAINS WHERE AFTERNOON TEMPERATURES WILL REACH THE MID-UPPER 90S WITH DEWPOINTS IN THE 70S. STEEP LOW-LEVEL LAPSE RATES...MLCAPE OF 3000-4000 J/KG...DCAPE IN EXCESS OF 1000 J/KG...AND MINIMAL VERTICAL SHEAR WILL SUPPORT A FEW PULSE-TYPE STORMS CAPABLE OF PRODUCING WET MICROBURSTS WITH DAMAGING WINDS. ...NRN PLAINS THROUGH TONIGHT... AN ONGOING CLUSTER OF THUNDERSTORMS ALONG THE INTERNATIONAL BORDER WILL LIKELY PERSIST INTO THIS AFTERNOON ACROSS NE ND AND NRN MN. THIS CONVECTION APPEARS TO BE BASED IN THE 850-700 MB LAYER...IN ASSOCIATION WITH LOW-LEVEL WAA AND STEEP MID LEVEL LAPSE RATES SAMPLED IN THE 12Z BIS SOUNDING. CLOUDS ACROSS THE AREA WILL SLOW SURFACE HEATING...THOUGH THE CONVECTION COULD BECOME ROOTED NEAR THE GROUND WITH TEMPERATURES IN THE LOWER 80S. MARGINALLY SEVERE HAIL AND ISOLATED DAMAGING GUSTS WILL BE THE PRIMARY SEVERE THREATS. FARTHER W...STRONG SURFACE HEATING /AFTERNOON TEMPERATURES IN THE LOW-MID 90S/ WILL RESULT IN DEEP INVERTED-V PROFILES NEAR THE LEE CYCLONE IN WRN ND. THOUGH LOW-LEVEL MOISTURE IS SOMEWHAT LIMITED THIS AREA AND STORM COVERAGE MAY BE RATHER SPARSE...THE STEEP LOW-LEVEL LAPSE RATES MAY SUPPORT VERY ISOLATED STRONG OUTFLOW WINDS LATER THIS AFTERNOON/EVENING. A PRONOUNCED MID LEVEL TROUGH NOW OVER SE BRITISH COLUMBIA WILL APPROACH THE NRN HIGH PLAINS LATE IN THE PERIOD...THOUGH MARGINAL MOISTURE AND INCREASING CONVECTIVE INHIBITION WILL TEND TO LIMIT THE THREAT FOR OVERNIGHT STORMS. ...SE ID THIS AFTERNOON... WATER VAPOR IMAGERY SHOWS A WEAK MID LEVEL WAVE MOVING NNEWD FROM ERN NV/NW UT TOWARD SE ID. SHORT TERM FORECAST SOUNDINGS...AND THE 12Z SLC SOUNDING MODIFIED FOR SURFACE HEATING...SHOW THE POTENTIAL FOR GUSTY OUTFLOW WINDS AND PERHAPS SMALL HAIL. ...CENTRAL OK TO CENTRAL AR THIS AFTERNOON... A QUASI-STATIONARY FRONT IS LOCATED NEAR I-40. STRONG SURFACE HEATING ALONG AND S OF THE FRONT WILL RESULT IN THE DEVELOPMENT OF MODERATE INSTABILITY AND A RELATIVELY DEEP BOUNDARY LAYER THIS AFTERNOON. WIDELY SCATTERED THUNDERSTORMS WILL LIKELY FORM ALONG THE FRONT BY MID AFTERNOON...A FEW OF WHICH WILL PRODUCE STRONG DOWNBURST WINDS. ..THOMPSON/TAYLOR.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 20:06:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 16:06:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042004 SWODY1 SPC AC 042003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT FRI AUG 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THRU EARLY TONIGHT ACROSS PARTS OF THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT ACROSS PARTS OF THE NRN PLAINS INTO NRN MN.... ...SYNOPSIS... LARGE MID/UPPER LEVEL RIDGE EXTENDS FROMCENTRAL/SRN HIGH PLAINS EWD INTO THE TN VALLEY AND CAROLINAS. MAIN BAND OF WESTERLIES RUN ALONG THE NRN TIER OF STATES FROM MT THRU THE GREAT LAKES WITH SEVERAL EMBEDDED SHORTWAVES. VIGOROUS MID/UPPER LEVEL LOW IS MOVG SEWD ACROSS ERN BRITISH COLUMBIA AND SRN ALBERTA AND IS EXPECTED TO BE INTO S CENTRAL SASKATCHEWAN. ...MID ATLANTIC/SERN STATES... LATEST SURFACE ANALYSIS SHOWS THAT COLD FRONTAL BOUNDARY EXTENDS FROM SERN MD...THEN CONTINUES SWWD/WWD AS A COMBINATION WEAK WIND SHIFT/CONVECTIVE BOUNDARY THRU THE TN VALLEY INTO NRN AR. SFC DEWPOINTS ARE IN THE 70S FROM SERN VA INTO THE GULF COAST REGION...FARTHER S THAN THE PAST FEW DAYS. THUS...FOCUS OF CONVECTION WILL BE IN THE FORM OF PULSE-TYPE ACTIVITY AND ITS ASSOCIATED BOUNDARIES FOR THE REMAINDER OF THE AFTN AND EARLY TONIGHT WITH THE MAIN THREAT BEING DAMAGING WINDS. ...PARTS OF THE NRN PLAINS EWD THRU NRN MN... LOW LEVEL WARM ADVECTION WILL BE INCREASING THRU TONIGHT ACROSS THE REGION. SWLY LOW LEVEL JET 35-45 KT WILL DEVELOP FROMCENTRAL NEB THRU N CENTRAL MN WHICH WILL ENHANCE VERTICAL SHEAR PROFILES ACROSS THE REGION. AIR MASS CONTINUES TO DESTABILIZE ACROSS CENTRAL ND WITH MLCAPE TO 1500 J/KG. PROBLEM ATTM LOKS TO BE LACK OF SUFFICIENT LOW LEVEL MOISTURE WITH DEW POINTS IN THE MID 50S. BUT WITH DEEP LAYER SHEAR OF 50-60 KT ACROSS THE NRN HALF OF ND...AND THAT THE SW CANADA SHORTWAVE TROUGH WILL BE MOVING INTO SASKATCHEWAN...EXPECT STRONG/SEVERE THUNDERSTORMS TO BE POSSIBLE AFTER 05/06Z ACROSS THIS REGION IF STORMS CAN DEVELOP ABOVE LOW LEVEL CAPPING INVERSION. ..MCCARTHY.. 08/04/2006  From swody1 at goshenarc.org Fri Aug 4 20:09:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 16:09:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 042008 SWODY1 SPC AC 042006 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0306 PM CDT FRI AUG 04 2006 VALID 042000Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS THRU EARLY TONIGHT ACROSS PARTS OF THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT ACROSS PARTS OF THE NRN PLAINS INTO NRN MN.... ...SYNOPSIS... LARGE MID/UPPER LEVEL RIDGE EXTENDS FROM CENTRAL/SRN HIGH PLAINS EWD INTO THE TN VALLEY AND CAROLINAS. MAIN BAND OF WESTERLIES RUNS ALONG THE NRN TIER OF STATES FROM MT THRU THE GREAT LAKES WITH SEVERAL EMBEDDED SHORTWAVES. VIGOROUS MID/UPPER LEVEL LOW IS MOVG SEWD ACROSS ERN BRITISH COLUMBIA AND SRN ALBERTA AND IS EXPECTED TO BE INTO S CENTRAL SASKATCHEWAN BY END OF THE PERIOD. ...MID ATLANTIC/SERN STATES... LATEST SURFACE ANALYSIS SHOWS THAT COLD FRONTAL BOUNDARY EXTENDS FROM SERN MD...THEN CONTINUES SWWD/WWD AS A COMBINATION WEAK WIND SHIFT/CONVECTIVE BOUNDARY THRU THE TN VALLEY INTO NRN AR. SFC DEWPOINTS ARE IN THE 70S FROM SERN VA INTO THE GULF COAST REGION...FARTHER S THAN THE PAST FEW DAYS. THUS...FOCUS OF CONVECTION WILL BE IN THE FORM OF PULSE-TYPE ACTIVITY AND ITS ASSOCIATED BOUNDARIES FOR THE REMAINDER OF THE AFTN AND EARLY TONIGHT WITH THE MAIN THREAT BEING DAMAGING WINDS. ...PARTS OF THE NRN PLAINS EWD THRU NRN MN... LOW LEVEL WARM ADVECTION WILL BE INCREASING THRU TONIGHT ACROSS THE REGION. SWLY LOW LEVEL JET 35-45 KT WILL DEVELOP FROM CENTRAL NEB THRU N CENTRAL MN WHICH WILL ENHANCE VERTICAL SHEAR PROFILES ACROSS THE REGION. AIR MASS CONTINUES TO DESTABILIZE ACROSS CENTRAL ND WITH MLCAPE TO 1500 J/KG. PROBLEM ATTM LOOKS TO BE LACK OF SUFFICIENT LOW LEVEL MOISTURE WITH DEW POINTS IN THE MID 50S. BUT WITH DEEP LAYER SHEAR OF 50-60 KT ACROSS THE NRN HALF OF ND...AND THAT THE SW CANADA SHORTWAVE TROUGH WILL BE MOVING INTO SASKATCHEWAN...EXPECT STRONG/SEVERE THUNDERSTORMS TO BE POSSIBLE AFTER 05/06Z ACROSS THIS REGION IF STORMS CAN DEVELOP ABOVE LOW LEVEL CAPPING INVERSION. ..MCCARTHY.. 08/04/2006  From swody1 at goshenarc.org Sat Aug 5 00:59:34 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 04 Aug 2006 20:59:34 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050052 SWODY1 SPC AC 050051 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0751 PM CDT FRI AUG 04 2006 VALID 050100Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE DAKOTAS... ...NRN PLAINS... MODEST QG-FORCING FOR ASCENT SPREADING ACROSS THE DAKOTAS WILL CONTINUE TO LOCALLY OVERCOME STRONG INHIBITION AND MAINTAIN THE CHANCE FOR SCATTERED SEVERE TSTMS FROM THE CNTRL TO ERN DAKOTAS TONIGHT. EFFECTIVE SHEAR AND LAPSE RATES ACROSS THE REGION REMAIN SUPPORTIVE OF ISOLATED SUPERCELLS AND LINE SEGMENTS CAPABLE OF PRODUCING HAIL AND HIGH WINDS. A STRONGER SYSTEM WILL DIG SEWD ACROSS NERN MT AND NWRN ND THROUGH DAYBREAK. FORCING/COLD FRONT ASSOCIATED WITH THIS SYSTEM MAY SPUR ADDITIONAL SEVERE STORM DEVELOPMENT OVER PARTS OF NWRN/NRN ND INTO EARLY SATURDAY. FARTHER EAST...LOW-AMPLITUDE SHORT WAVE TROUGH NOW MOVING OVER THE DAKOTAS MAY ENHANCE WARM ADVECTION AND MASS TRANSPORT ON THE EDGE OF THE CAP FROM NRN MN TO WRN SECTIONS OF THE U.P. OF MI/LAKE SUPERIOR. A FEW STRONG STORMS WITH SOME HAIL POTENTIAL MAY SPREAD ACROSS THESE AREAS OVERNIGHT. ...NORTHEAST GULF COAST... LARGE CLUSTER OF MULTICELLULAR CONVECTION HAS GROWN UPSCALE AND WAS DRIFTING SWWD ACROSS SWRN GA AND NRN FL THIS EVENING. THIS COMPLEX OF STORMS SHOULD CONTINUE TO POSE A THREAT OF ISOLATED WET DOWNBURSTS FOR AT LEAST ANOTHER HOUR OR SO GIVEN VERY MOIST AND UNSTABLE CONDITIONS REMAINING ACROSS THE REGION AND SOME LARGE SCALE SUPPORT FROM UPPER LOW TRACKING WWD ACROSS FL. ...SOUTHEAST... ISOLATED ACTIVITY EXPECTED TO PERSIST...AND MAY INCREASE SOMEWHAT...IN WEAKLY SHEARED BUT VERY UNSTABLE AIR MASS FROM NRN GA ACROSS THE CAROLINAS AND SERN VA. RESIDUAL COLD FRONT AND LEE TROUGH...IN ADDITION TO NUMEROUS COMPOSITE OUTFLOW AND SEA BREEZE BOUNDARIES...MAY CONTINUE TO AID WIDELY SCATTERED UPDRAFT/PULSE STORM DEVELOPMENT. THE REGION ALSO LIES BENEATH FAVORABLE DIFFLUENT FLOW PATTERN ALOFT WHICH COULD MAINTAIN AT LEAST AN ISOLATED SEVERE THREAT DESPITE TIME OF DAY. ...ERN OK/SWRN AR... MESOSCALE ASCENT BEHIND LEADING EDGE OF WWD MOVING CONVECTIVE OUTFLOW FROM ERN OK INTO SWRN AR MAY CONTINUE TO PROMOTE PULSE STORM DEVELOPMENT OVER THESE AREAS FOR ANOTHER HOUR OR SO. BRIEF WIND DAMAGE POTENTIAL WILL BE GREATEST BENEATH UPDRAFTS FORMING OR DRIFTING INTO HOT AND DEEPLY MIXED AIR MASS AROUND THE ARKLATEX OVER THE NEXT 1-2 HOURS. ...NRN NEW ENGLAND... LIFT ASSOCIATED WITH A COLD FRONT APPROACHING WARM AND WEAKLY UNSTABLE AIR MASS OVER MAINE HAS RESULTED IN AN ARC OF STRONG STORMS OVER THIS REGION SINCE LATE AFTERNOON. MID LEVEL JET STREAK AND ASSOCIATED FRONT WILL CONTINUE TO SPREAD SEWD THROUGH TONIGHT AS BOUNDARY LAYER BECOMES INCREASINGLY STABLE. LOCALLY STRONG WIND GUSTS MAY ACCOMPANY SOME OF THE STRONGER CORES OVER THE NEXT HOUR BUT SEVERE WEATHER POTENTIAL WITH THIS ACTIVITY APPEARS TO BE LOW. ..CARBIN.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 05:29:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 01:29:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 050528 SWODY1 SPC AC 050527 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1227 AM CDT SAT AUG 05 2006 VALID 051200Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN NORTH DAKOTA AND NERN SOUTH DAKOTA ACROSS MUCH OF MINNESOTA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM THE CNTRL DAKOTAS AND NRN NEB...EAST ACROSS NRN IA AND THE UPPER MS VALLEY/WRN GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NORTHEAST GULF COAST AND PARTS OF THE SOUTHEAST... ...WIDESPREAD SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND LARGE HAIL ARE EXPECTED TO DEVELOP EAST ACROSS PARTS OF THE DAKOTAS AND MINNESOTA THIS AFTERNOON AND TONIGHT... ...SYNOPSIS... BROAD MID-UPPER LEVEL SUBTROPICAL RIDGE AXIS WILL REMAIN SITUATED ACROSS THE SCNTRL U.S. FROM THE FOUR CORNERS REGION EWD TO THE MID ATLANTIC AND SOUTHEAST. BELT OF ZONAL NRN STREAM FLOW WILL CONTAIN A POTENT...PROGRESSIVE...AND COMPACT SHORT WAVE DISTURBANCE WHICH WILL TRANSLATE EWD FROM NERN MT TO SRN ONTARIO AND THE UPPER MS VALLEY DURING THE PERIOD. WHILE ASSOCIATED SURFACE CYCLOGENESIS WITH THIS NRN STREAM IMPULSE WILL OCCUR OVER THE CANADIAN PRAIRIES THROUGH THE DAY TODAY...MODEST HEIGHT FALLS AND INCREASINGLY DIFFLUENT FLOW ON THE NOSE 0F 50-70 KT MID LEVEL JET WILL SPREAD EAST ATOP STRONGLY UNSTABLE WARM SECTOR FROM THE ERN DAKOTAS TO MN. SEVERE STORMS ARE EXPECTED TO FORM AHEAD OF ASSOCIATED COLD FRONT WHICH WILL SWEEP ESEWD ACROSS THE NRN PLAINS TO THE WRN GREAT LAKES REGION FROM LATE THIS AFTERNOON THROUGH EARLY SUNDAY. ...NRN PLAINS TO UPPER MS VALLEY... INGREDIENTS APPEAR TO BE COMING TOGETHER FOR POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE ACROSS ERN ND...NERN SD...AND MN LATER THIS AFTERNOON AND TONIGHT. A LEADING LOW-AMPLITUDE SHORT WAVE TROUGH AND MODEST LOW LEVEL JET DIRECTED INTO MN WERE AIDING LOW LEVEL MOISTURE RETURN AND MAINTAINING WEAK CONVECTIVE ACTIVITY ACROSS THE AREA ATTM. EARLY ELEVATED CONVECTION IS EXPECTED TO DISSIPATE RAPIDLY AFTER SUNRISE AS LOW LEVEL FLOW FIELDS ADJUST TO INFLUENCE OF STRONGER UPSTREAM IMPULSE MOVING ESEWD FROM NERN MT. INTENSE SURFACE HEATING BENEATH PRONOUNCED ELEVATED MIXED LAYER AND ADIABATIC COOLING ALOFT ASSOCIATED WITH THE APPROACHING TROUGH WILL LEAD TO THE DEVELOPMENT OF STRONG INSTABILITY AHEAD OF DRYLINE/COLD FRONT BY AFTERNOON. MLCAPE ACROSS THE CNTRL/ERN DAKOTAS SHOULD EASILY CLIMB TO 2000 J/KG WITH INITIALLY STRONG CAPPING ALLOWING LOW LEVEL MOISTURE AND INSTABILITY TO CONTINUE TO BUILD THROUGH THE AFTERNOON. AS TEMPERATURES CLIMB THROUGH THE 90S F...AND STRONGER QG FORCING ARRIVES ATOP THE VERY UNSTABLE WARM SECTOR...REMAINING INHIBITION WILL FIRST BE OVERCOME ACROSS ERN/NERN ND WHERE RAPID TO EXPLOSIVE TSTM DEVELOPMENT SHOULD ENSUE BEFORE LATE AFTERNOON. ADDITIONAL SCATTERED DEVELOPMENT SWD/SWWD ACROSS THE WARM SECTOR MAY OCCUR FROM LATE AFTERNOON THROUGH EARLY EVENING AS STRONG DYNAMIC FORCING ASSOCIATED WITH THE TROUGH AND DRYLINE/FRONT ACT TO OVERCOME THE CAP FROM NERN SD SWWD INTO THE NCNTRL PLAINS. VERTICAL SHEAR AND FORCING WILL BE MORE THAN ADEQUATE FOR ORGANIZED SEVERE STORMS WITH INITIAL ACTIVITY RAPIDLY BECOMING SUPERCELLULAR AND PRODUCING VERY LARGE HAIL. FORECAST SOUNDINGS ALSO DEPICT SUFFICIENT DIRECTIONAL SHEAR AND LOW LEVEL CAPE IN THE STORM UPDRAFT LAYER FOR POTENTIALLY STRONG LOW-LEVEL MESOCYCLONES. TORNADOES MAY DEVELOP FROM DISCRETE STORMS PERSISTING NEAR RESIDUAL OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES...AS WELL AS FROM STRONG UPDRAFT/DOWNDRAFT COUPLETS OCCURRING NEAR BREAKS IN ANY LINE SEGMENTS. CONVECTION SHOULD TREND TOWARD SQUALL-LINEAR MODE INTO THE EVENING WITH WIDESPREAD DAMAGING WINDS POSSIBLE AS STORM COVERAGE INCREASES AND RESULTANT COLD POOLS STRENGTHEN AND MERGE. STRONG MID LEVEL DRY PUNCH AND ENHANCED MESOSCALE ASCENT ON THE EDGE OF THE PLAINS CAPPING INVERSION SHOULD MAINTAIN THE THREAT OF BOWING LINE SEGMENTS...HAIL...AND ISOLATED/BRIEF TORNADOES ACROSS MN/NRN IA...INTO WI...AND PERHAPS THE U.P. OF MI...INTO LATE SATURDAY NIGHT/EARLY SUNDAY. ...NERN GULF COAST/SOUTHEAST... VERY MOIST AND INCREASINGLY UNSTABLE AIR MASS WILL AGAIN SUPPORT THE DEVELOPMENT OF NUMEROUS PULSE/MULTICELL STORMS ACROSS THESE AREAS TODAY. WHILE WEAK SHEAR WILL LIMIT OVERALL ORGANIZATION... ACTIVITY PERSISTING ALONG RESIDUAL FRONTAL BOUNDARY...AND ALSO AIDED BY LARGE SCALE INFLUENCE OF WWD MOVING TROUGH OVER THE ERN GULF...WILL POSE SOME THREAT FOR LOCALLY DAMAGING WINDS AND MARGINALLY SEVERE HAIL. ..CARBIN/GUYER.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 13:00:26 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 09:00:26 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051300 SWODY1 SPC AC 051258 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0758 AM CDT SAT AUG 05 2006 VALID 051300Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN ND INTO ERN SD AND MUCH OF NRN / WRN MN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA SWD / EWD INTO THE MID MO AND UPR MS VLYS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CNTRL GULF CST REGION... ...SYNOPSIS... UPR RIDGE WILL REMAIN ANCHORED OVER THE SRN PLNS THIS PERIOD AS POTENT SHORTWAVE IMPULSE NOW OVER SRN SASKATCHEWAN SWEEPS E IN STRONG ZONAL JET JUST N OF THE CANADIAN BORDER. THE SYSTEM SHOULD AMPLIFY INTO A CLOSED LOW NEAR LK WINNIPEG EARLY TONIGHT...AND REACH WRN ONTARIO EARLY SUNDAY. FARTHER S...SATELLITE AND VWP DATA SHOW TWO WEAKER DISTURBANCES IN THE BELT OF MODERATE FLOW TOPPING THE PLNS RIDGE. ONE OF THE THESE IS OVER FSD/SUX ATTM...AND THE OTHER OVER N CNTRL WY. AT THE SURFACE...COLD FRONT ATTENDING CANADIAN IMPULSE EXPECTED TO MOVE STEADILY SE ACROSS THE NRN PLNS TODAY...AND INTO THE UPR MS VLY/CNTRL PLNS TONIGHT/EARLY SUNDAY. AHEAD OF THE COLD FRONT... LATEST SURFACE DATA AND SATELLITE/GPS PWS SHOW MOISTURE RETURN CONTINUING INVOF DIFFUSE WARM FRONT EXTENDING FROM THE CNTRL DAKOTAS SSE INTO ERN KS/NE OK. MOISTURE LIKELY WILL CONTINUE TO SPREAD NWD INTO THE ERN DAKOTAS/WRN MN TODAY. SURFACE DEWPOINTS COULD REACH THE MID 60S IN THE RED RVR VLY REGION BY MID AFTERNOON...WITH VALUES IN THE UPPER 60S POSSIBLE FARTHER S ACROSS ERN SD/SW MN. THE W/E BREADTH OF THE MOISTURE RETURN AXIS WILL...HOWEVER...LIKELY REMAIN LIMITED AS GRT LKS SURFACE RIDGE EXPECTED TO EDGE ONLY SLOWLY EWD. ...NRN PLNS/UPR MS VLY... ELEVATED TSTMS ARE ALREADY IN PROGRESS IN NW/N CNTRL ND...IN WARM ADVECTION ZONE DOWNSTREAM FROM SASKATCHEWAN TROUGH. THIS ACTIVITY SHOULD CONTINUE E ACROSS ND THROUGH THE DAY...WITH SOME SWD DEVELOPMENT LIKELY OVER TIME AS STORMS/FORCING ENCOUNTER INCREASING LOW LEVEL MOISTURE RETURN AND OVERCOME CAP. COUPLED WITH EXPECTED SURFACE HEATING AND CONTINUED E/SEWD PROGRESS OF COLD FRONT...EXPECT THAT CELLS WILL EVENTUALLY BECOME SURFACE-BASED AND MARKEDLY STRENGTHEN...MOST LIKELY OVER THE RED RVR VLY. OTHER VIGOROUS STORMS SHOULD FORM A BIT LATER IN THE AFTERNOON SWD ALONG MERGING COLD FRONT/PREFRONTAL TROUGH OVER ERN SD/WRN MN. AMPLE DEEP SPEED AND DIRECTIONAL SHEAR WILL BE PRESENT FOR SUSTAINED SUPERCELLS...ESPECIALLY IN ND AND NRN MN...WHERE 500 MB WLY FLOW WILL INCREASE TO AROUND 50 KTS ON SRN SIDE OF UPR TROUGH. SOMEWHAT WEAKER DEEP SHEAR WILL BE COMPENSATED BY GREATER INSTABILITY /SBCAPE TO 3000 J PER KG/ TO SUPPORT SUSTAINED UPDRAFTS/SUPERCELLS SWD INTO ERN/SRN SD AND SW MN. BY EARLY EVENING...STRONG STORMS COULD DEVELOP SWD INTO NRN NEB. COMBINATION OF MODERATE TO STRONG DEEP SHEAR...STEEP MID LEVEL LAPSE RATES AND INCREASING MOISTURE LIKELY WILL PROMOTE A FEW UPDRAFTS WITH VERY LARGE HAIL FROM THE RED RVR VLY S/SW INTO PARTS OF SD/WRN MN. AND...WHILE OVERALL CONDITIONS DO NOT APPEAR IDEAL...A FEW TORNADOES ALSO APPEAR POSSIBLE...ESPECIALLY DURING EXPECTED PERIOD OF STORM INTENSIFICATION IN THE RED RVR VLY...AND DURING EARLY STAGES OF STORM DEVELOPMENT IN ERN SD/SW MN. FOCUSED AND LINEAR FORCING FOR ASCENT SUGGEST THAT ACTIVITY WILL FAIRLY QUICKLY ORGANIZE INTO A BROKEN LINE MODE THIS EVENING. EMBEDDED SUPERCELLS WILL CONTINUE TO POSE A THREAT FOR HIGH WIND/HAIL AND ISOLATED TORNADOES...ESPECIALLY BENEATH BELT OF STRONGER FLOW ALOFT IN NRN MN...AND INVOF MERGING BOUNDARIES SRN MN/SE SD. WHILE THE SRN MN/SE SD ACTIVITY MAY REMAIN SEVERE INTO SUNDAY MORNING...AND FORWARD-PROPAGATE E INTO NRN IA/SW WI... NARROW NATURE OF INSTABILITY AXIS SHOULD LIMIT EWD EXTENT OF HIGH-END /DERECHO/ SEVERE THREAT INTO THE LK SUPERIOR REGION. ...NERN GULF COAST/SOUTHEAST... STRONGLY HEATED...VERY MOIST/UNSTABLE AIR WILL AGAIN SUPPORT POCKETS OF DIURNAL PULSE/MULTICELL STORMS IN AREAS WHERE DEEP CONFLUENCE IS FAVORED ON LEADING EDGE OF ELY WAVE CROSSING THE SERN STATES. WHILE WEAK SHEAR WILL LIMIT ORGANIZATION...SOME STORMS WILL POSE A THREAT FOR LOCALLY DAMAGING WIND/MARGINALLY SEVERE HAIL. ..CORFIDI/GUYER.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 16:38:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 12:38:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051638 SWODY1 SPC AC 051636 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT SAT AUG 05 2006 VALID 051630Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS THE ERN DAKOTAS AND MN.... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA...FROM THE NRN PLAINS TO THE UPPER MS VALLEY.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FROM LA/SRN MS TO CENTRAL GA AND SC.... ...NRN PLAINS AND UPPER MS VALLEY THROUGH TONIGHT... A STRONG MID LEVEL SHORTWAVE TROUGH OVER SRN SASKATCHEWAN WILL MOVE EWD OVER ND/SRN MANITOBA TODAY AND INTO WRN ONTARIO/NRN MN TONIGHT. AN ASSOCIATED SURFACE COLD FRONT ACROSS WRN ND THIS MORNING WILL MOVE SEWD ACROSS ERN ND AND CENTRAL SD BY THIS EVENING...REACHING AN AXIS FROM CENTRAL NEB TO NW IA TO NW WI BY 06/12Z. A SEPARATE LEE CYCLONE IN SW SD WILL GRADUALLY FILL AND DRIFT SWD/SEWD THROUGH TONIGHT. THE COLD FRONT IS EXPECTED TO BE THE PRIMARY FOCUS FOR SEVERE THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON INTO EARLY TONIGHT. THE REMNANTS OF OVERNIGHT CONVECTION...ASSOCIATED WITH AN INITIAL MID LEVEL WAVE NOW MOVING OVER MN/IA...PERSIST OVER SRN IA. BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S ARE RETURNING NWD ACROSS THE ERN DAKOTAS TO THE W OF THIS CONVECTION...THOUGH THE RICHEST MOISTURE IS CONFINED TO AREAS FROM ERN KS SWD TO THE GULF COAST. ANOTHER MINOR MID LEVEL WAVE IS MOVING EWD FROM NW SD/SE MT INTO CENTRAL ND. THE BAND OF CLOUDS OVER CENTRAL ND AND THE ELEVATED THUNDERSTORMS IN NE ND APPEAR TO BE ASSOCIATED WITH THIS WAVE...AND LOCAL VWP/S CONFIRM A PRONOUNCED VEERING OF LOW-LEVEL FLOW IN ND WITH PASSAGE OF THIS WAVE. THE 12Z BIS SOUNDING REVEALED VERY STEEP MID LEVEL LAPSE RATES...BUT A STRONG CAP FOR SURFACE PARCELS AND CONVECTIVE TEMPERATURES IN THE MID 90S. THE CLOUDS...MODEST MOISTURE...AND STRONG CAP ALL SUGGEST THAT SURFACE-BASED THUNDERSTORM DEVELOPMENT WILL LIKELY BE CONFINED TO THE IMMEDIATE COLD FRONT THIS AFTERNOON/EVENING ACROSS THE ERN DAKOTAS INTO WRN MN. MODIFYING THE 12Z BIS AND MODEL FORECAST SOUNDINGS FOR EXPECTED AFTERNOON BOUNDARY LAYER CONDITIONS...MLCAPE VALUES RANGE FROM 1500 J/KG ACROSS NW MN TO 3000 J/KG INVOF SE SD WHERE RICHER MOISTURE WILL SPREAD NWD ALONG THE MO RIVER VALLEY. DEEP LAYER VERTICAL SHEAR MAGNITUDE AND ORIENTATION WITH RESPECT TO THE FRONT APPEARS SUPPORTIVE OF A BROKEN BAND OF SUPERCELLS AND/OR SHORT LINE SEGMENTS THROUGH THE AFTERNOON/EVENING. VERY LARGE HAIL AND DAMAGING WINDS ARE LIKELY WITH ANY SUPERCELLS IN THE LINE. A COUPLE OF TORNADOES WILL ALSO BE POSSIBLE THIS EVENING...WITH A LITTLE GREATER THREAT IN MN WHERE LOW-LEVEL SHEAR/MOISTURE WILL BE SOMEWHAT GREATER THAN AREAS FARTHER W. ...GULF AND SE ATLANTIC COASTS THIS AFTERNOON... LOW-LEVEL DRYING HAS OCCURRED ACROSS THE SE ATLANTIC STATES COMPARED TO YESTERDAY MORNING...AS THE MID LEVEL WAVE IN THE ELYS PROGRESSES WWD OVER THE NE GULF AND FL PANHANDLE/SRN AL. IT APPEARS THAT THE GREATER INSTABILITY THIS AFTERNOON WILL BE FROM SRN MS INTO LA IN ADVANCE OF THE MID LEVEL WAVE. THE NE MID LEVEL FLOW WILL FAVOR MULTICELL CLUSTERS THAT MOVE INTO THE LOW-LEVEL HEAT/MOISTURE AXIS...WHILE VERTICAL PROFILES FAVOR A FEW STORMS WITH WET MICROBURSTS AND PERHAPS MARGINALLY SEVERE HAIL. THOUGH DEEP LAYER FLOW IS WEAK OVER THE CAROLINAS...A SURFACE FRONT WILL PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON. DEWPOINTS IN THE 70S AND AFTERNOON TEMPERATURES IN THE 90S WILL SUPPORT MLCAPE VALUES OF 2000-3000 J/KG...ALONG WITH DCAPE VALUES IN EXCESS OF 1000 J/KG. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING DAMAGING DOWNBURST WINDS. ACROSS FL AND SE GA...SCATTERED SEA BREEZE STORMS WILL OCCUR AGAIN THIS AFTERNOON...THOUGH THE SEVERE STORM THREAT WILL BE LIMITED BY WARMING MID LEVEL TEMPERATURES AND REDUCED INSTABILITY COMPARED TO YESTERDAY. ..THOMPSON/TAYLOR.. 08/05/2006  From swody1 at goshenarc.org Sat Aug 5 19:49:01 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 15:49:01 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 051949 SWODY1 SPC AC 051947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SAT AUG 05 2006 VALID 052000Z - 061200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MN...ND...SD... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS...CNTRL PLAINS AND NRN MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SERN U.S.... ...NRN AND CNTRL PLAINS/UPPER MS VALLEY... LATEST WATER VAPOR IMAGERY SHOWS A WELL-DEFINED UPPER-LEVEL TROUGH MOVING EWD ACROSS SASKATCHEWAN AND THE NRN HIGH PLAINS WITH A LEAD TROUGH OVER ERN ND. AT THE SFC....A COLD FRONT IS LOCATED IN CNTRL ND AND NW SD WITH SFC DEWPOINTS ACROSS THE WARM SECTOR IN THE 60S F RESULTING IN MODERATE TO STRONG INSTABILITY. THUNDERSTORMS ARE DEVELOPING IN SE ND AND NW MN ALONG THE LEADING EDGE OF LARGE-SCALE ASCENT ASSOCIATED WITH THE LEAD SHORTWAVE TROUGH. STORM COVERAGE SHOULD CONTINUE TO EXPAND LATE THIS AFTERNOON ALONG THE INSTABILITY AXIS AS LARGE-SCALE ASCENT CONTINUES TO INCREASE FROM WEST TO EAST ACROSS THE REGION. OBJECTIVE ANALYSIS CURRENTLY SHOWS A 70 KT MID-LEVEL JET OVER NW ND WITH STRONGER MID-LEVEL FLOW SPREADING EWD ACROSS THE DAKOTAS. THIS WILL STRENGTHEN DEEP LAYER SHEAR ACROSS THE REGION WITH 0-6 KM SHEAR VALUES LIKELY REACHING 40 TO 50 KT ACROSS THE MODERATE RISK AREA BY LATE AFTERNOON/EARLY EVENING. IN ADDITION...LAPSE RATES WILL CONTINUE TO STEEPEN WHICH WITH THE INCREASING SHEAR SHOULD BECOME FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. THE STRONGEST SUPERCELLS SHOULD BE CAPABLE OF PRODUCING VERY LARGE HAIL AND WIND DAMAGE. VERY STRONG WIND GUSTS AND A FEW TORNADOES WILL BE POSSIBLE WITH THE STRONGER SUPERCELLS AND/OR BOW ECHOES ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS LATE THIS AFTERNOON AND EARLY THIS EVENING. THE SEVERE THREAT SHOULD CONTINUE THROUGH THE EVENING AND POSSIBLY INTO THE OVERNIGHT PERIOD AS A LINEAR MCS ORGANIZES AHEAD OF THE FRONT AND MOVES EWD ACROSS THE REGION. ...SERN U.S... A WEAK FLOW REGIME IS CURRENTLY IN PLACE ACROSS THE SERN U.S. WITH A STATIONARY FRONT LOCATED FROM LA EXTENDING ENEWD ACROSS CNTRL MS...NCNTRL AL...NRN GA AND SC. MODERATE INSTABILITY IS PRESENT ALONG THE BOUNDARY AND LOW-LEVEL CONVERGENCE IS HELPING INITIATE SCATTERED TO NUMEROUS THUNDERSTORMS ACROSS THE REGION. ALTHOUGH WIND SHEAR PROFILES ARE RELATIVELY WEAK...LOW-LEVEL LAPSE RATES ARE VERY STEEP AND EXCEED 8.0 C/KM IN SOME AREAS. THIS SHOULD BE FAVORABLE FOR ISOLATED DAMAGING WINDS WITH THE STRONGER CELLS THROUGH THE REMAINDER OF THE AFTERNOON. ..BROYLES.. 08/05/2006  From swody1 at goshenarc.org Sun Aug 6 01:07:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 05 Aug 2006 21:07:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060106 SWODY1 SPC AC 060104 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0804 PM CDT SAT AUG 05 2006 VALID 060100Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN PLAINS AND UPPER MS VALLEY... ...ERN DAKOTAS AND MN... POTENT MID-UPPER LEVEL DISTURBANCE WAS CLEARLY EVIDENT ON WATER VAPOR IMAGERY ACROSS SRN MANITOBA AND NRN ND THIS EVENING. DIFFLUENT MID LEVEL FLOW FIELD AHEAD OF THIS IMPULSE WAS AIDING DEEP LAYER ASCENT ALONG AN ADVANCING ASSOCIATED COLD FRONT FROM NRN MN SWWD INTO NCNTRL SD. STRONGEST DYNAMIC FORCING ASSOCIATED WITH THE MID LEVEL SYSTEM WILL CONTINUE TO TRAVEL ACROSS NRN MN THROUGH TONIGHT WHILE SOMEWHAT WEAKER LARGE SCALE FORCING WILL ACCOMPANY THE FRONTAL PASSAGE FROM ERN SD ACROSS SRN MN AND NRN IA THROUGH EARLY SUNDAY. A FEW INTENSE SUPERCELLS HAVE DEVELOPED AHEAD OF THE FRONT... ACROSS ERN ND AND NRN MN...WHERE DYNAMIC FORCING HAS ACTED TO LOCALLY OVERCOME STRONG CONVECTIVE INHIBITION. THIS ACTIVITY APPEARS TO HAVE RECENTLY INCREASED IN COVERAGE AND INTENSITY AS IT MOVES INTO AN INSTABILITY AXIS WHERE PRONOUNCED SPEED AND DIRECTIONAL SHEAR WILL CONTINUE TO SUPPORT UPDRAFT ROTATION AND STORM PERSISTENCE. DIAGNOSTIC DATA CONTINUE TO SUGGEST THAT BOTH VERY LARGE HAIL AND ISOLATED TORNADOES WILL BE POSSIBLE WITH THESE CELLS AS THEY TRACK ACROSS PARTS OF SERN ND AND NWRN/NRN MN THIS EVENING. FARTHER SOUTH AND EAST...MSP SOUNDING DEPICTED PRONOUNCED WARM LAYER ABOVE 800 MB CONTRIBUTING TO SIGNIFICANT INHIBITION...WHICH LIKELY COVERS MUCH OF THE WARM SECTOR AHEAD OF THE FRONT. A CLUSTER OF POORLY ORGANIZED STORMS ON THE SRN FRINGE OF STRONGER DEEP LAYER SHEAR PERSISTS FROM NERN NEB INTO EXTREME SERN SD. THIS ACTIVITY INITIATED EARLIER ON THE APEX OF SURFACE THERMAL RIDGE AXIS/TROUGH WHERE DEEP MIXING IN VERY HOT AIR MASS WAS SUFFICIENT TO OVERCOME CONVECTIVE INHIBITION /SEE OAX EVENING RAOB/. MEANWHILE...ISOLATED STORM UPDRAFTS HAVE STRUGGLED TO TAKE ROOT ALONG THE FRONTAL WIND SHIFT OVER CNTRL/NERN SD. OVERNIGHT EVOLUTION OF CONVECTION ACROSS THESE AREAS...EWD ACROSS IA/SRN MN...REMAINS UNCERTAIN. CURRENT ACTIVITY SHOULD CONTINUE TO POSE A THREAT OF ISOLATED WIND AND HAIL. LATEST NAM-WRF AND RUC DEPICT DIFFERING SOLUTIONS WITH THE NAM-WRF DEVELOPING AN MCS ACROSS IA...AND RUC KEEPING STRONGER UVV AND QPF SIGNALS FARTHER NORTH...ACROSS MN. IT SEEMS POSSIBLE THAT A SEVERE MCS MAY DEVELOP ACROSS NRN IA/SRN MN LATER TONIGHT AS FRONTAL LIFT MOVES SEWD INTO VERY MOIST AND UNSTABLE AIR MASS...AND MASS TRANSPORT INTO THE REGION IS MAXIMIZED ON THE NOSE OF PLAINS LOW LEVEL JET. ...SOUTHEAST... POCKETS OF STRONG INSTABILITY REMAIN SITUATED AHEAD OF SCATTERED CLUSTERS OF PERSISTENT CONVECTION FROM LA EWD TO SC LATE THIS EVENING. CELL MERGERS AND LIFT ALONG COMPOSITE OUTFLOWS MAY BE SUFFICIENT FOR A FEW ROBUST UPDRAFTS...AND POSSIBLY LEAD TO NEW DEVELOPMENT...OVER THE NEXT COUPLE OF HOURS. ISOLATED WET DOWNBURSTS PRODUCING DAMAGING WINDS APPEAR TO BE THE MAIN HAZARD UNTIL BOUNDARY LAYER STABILIZES FURTHER. ..CARBIN.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 04:51:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 00:51:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 060452 SWODY1 SPC AC 060450 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1150 PM CDT SAT AUG 05 2006 VALID 061200Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLAINS TO PARTS OF THE UPPER MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY/CNTRL APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX COASTAL PLAIN/SRN LA... ...SYNOPSIS... TYPICAL SUMMERTIME FLOW REGIME WILL CONTINUE THIS PERIOD WITH LARGE SUBTROPICAL RIDGE DOMINATING THE SRN 2/3RDS OF THE CONUS AND A BROAD BAND OF CYCLONIC FLOW SPREADING ESEWD FROM SCNTRL CANADA AND THE UPPER MS VALLEY...ACROSS THE GREAT LAKES...TO THE ST. LAWRENCE VALLEY/NRN NEW ENGLAND BY THE END OF THE PERIOD. A CLOSED LOW OFF THE CA COAST WILL BEGIN TO OPEN UP AND MOVE NEWD TOWARD THE NORTHWEST COAST TODAY AND TONIGHT AS DOWNSTREAM UPPER RIDGE BUILDS ACROSS THE NRN ROCKIES. LONG-LIVED SUBTROPICAL GYRE WILL MOVE ACROSS THE TX GULF COAST TODAY WHILE SMALLER SCALE WAVE MOVES WWD FROM THE FL STRAITS INTO THE CNTRL GULF. ...CNTRL PLAINS/MIDWEST... AS STRONGER HEIGHT FALLS ASSOCIATED WITH PROGRESSIVE IMPULSE OVER ONTARIO CONTINUE TO SPREAD EAST...TRAILING FRONT/WIND SHIFT...FROM WRN GREAT LAKES REGION SWWD TO IA/NEB...WILL EVENTUALLY WEAKEN ACROSS THESE AREAS WITH TIME. HOWEVER...RESIDUAL CLOUDS AND CONVECTION...COUPLED WITH PERSISTENT CONVERGENCE ALONG THE BOUNDARY...WILL ESTABLISH A ZONE OF ENHANCED MESOSCALE ASCENT FROM SRN WI WSWWD TO THE CNTRL HIGH PLAINS THIS AFTERNOON. STRONG HEATING AND DESTABILIZATION WITHIN THIS ZONE WILL LIKELY FUEL AFTERNOON AND EVENING TSTMS...A FEW OF WHICH COULD BE SEVERE. WEAK POST FRONTAL FLOW WITH SOME ELY/UPSLOPE COMPONENT WILL BE TOPPED BY 15-30KT WLY FLOW ALOFT AND RESULT IN MARGINALLY SUPPORTIVE DEEP LAYER SHEAR FOR UPDRAFT PERSISTENCE/ROTATION... AND PERHAPS SOME HAIL. IN ADDITION...DAMAGING OUTFLOW WINDS WILL BE POSSIBLE FROM STORMS DEVELOPING NEAR THE RESIDUAL FRONT AND MOVING INTO STRONGLY HEATED AND DEEPLY MIXED BOUNDARY LAYER FROM NEB/KS BORDER EWD ACROSS SRN IA/NRN MO. ...UPPER OH VALLEY/CNTRL APPALACHIANS... INCREASING WARM AIR AND MOISTURE ADVECTION IS FORECAST TO DEVELOP ON THE WRN PERIPHERY OF EAST COAST ANTICYCLONE AND MAY BE FURTHER ENHANCED/CHANNELED IN THE LOW LEVELS ALONG THE WRN SLOPES OF THE CNTRL APPALACHIANS. THIS PROCESS IS EXPECTED TO RESULT IN THE DEVELOPMENT OF STRONG INSTABILITY WITH HEATING OF THE DAY FROM THE TN VALLEY NEWD ACROSS THE UPPER OH VALLEY. ISOLATED TO SCATTERED PULSE STORMS WILL BE POSSIBLE ACROSS MUCH OF THE AREA GIVEN WEAKLY CAPPED AND INCREASINGLY UNSTABLE BOUNDARY LAYER. THE POTENTIAL FOR ORGANIZED MULTICELL STORMS WITH SEVERE HAIL AND WIND MAY EVOLVE OVER PARTS OF ERN KY/SRN OH WHERE MID LEVEL FLOW IS FORECAST TO STRENGTHEN DURING THE DAY. WEAK HEIGHT FALLS ASSOCIATED WITH THE GREAT LAKES TROUGH WILL ALSO BRUSH THIS REGION AND MAY PROMOTE GREATER STORM COVERAGE/SEVERE POTENTIAL. ...SERN TX/SRN LA... TROPICAL MOISTURE AND STRONG HEATING WILL RESULT IN NUMEROUS TSTMS DEVELOPING ACROSS THE GULF COAST AND TX COASTAL PLAIN TODAY. LARGE SCALE ASCENT AND BAND OF ENHANCED CYCLONIC FLOW AROUND LARGE NWWD MOVING MID/UPPER LOW MAY SUPPORT CLUSTERS OF MULTICELL STORMS PRODUCING WET DOWNBURSTS. ...NRN CA/SRN ORE... BELT OF 25-30KT SLY FLOW ON ERN EDGE OF OPENING MID LEVEL WAVE WILL ARRIVE ACROSS NRN CA/SRN ORE COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. THE INCREASE IN SHEAR MAY RESULT IN ISOLATED SEVERE STORMS WITH SOME HAIL/WIND POTENTIAL OVER THESE AREAS INTO THE EVENING HOURS. ..CARBIN/GUYER.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 12:44:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 08:44:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061244 SWODY1 SPC AC 061242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0742 AM CDT SUN AUG 06 2006 VALID 061300Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO THE UPPER MIDWEST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE TX COASTAL PLAIN AND SRN LA... ...CNTRL PLAINS/MIDWEST... AS STRONGER HEIGHT FALLS ASSOCIATED WITH PROGRESSIVE IMPULSE OVER ONTARIO CONTINUE TO SPREAD EAST...TRAILING FRONT/WIND SHIFT...FROM WRN GREAT LAKES REGION SWWD TO IA/SERN NEB...WILL EVENTUALLY WEAKEN ACROSS THESE AREAS WITH TIME. HOWEVER...RESIDUAL CLOUDS AND CONVECTION...COUPLED WITH PERSISTENT CONVERGENCE ALONG THE BOUNDARY...WILL ESTABLISH A ZONE OF ENHANCED MESOSCALE ASCENT FROM SRN WI WSWWD TO THE CNTRL HIGH PLAINS THIS AFTERNOON. STRONG HEATING AND DESTABILIZATION WITHIN THIS ZONE WILL LIKELY FUEL AFTERNOON AND EVENING TSTMS...A FEW OF WHICH COULD BE SEVERE. WEAK POST FRONTAL FLOW WITH SOME ELY/UPSLOPE COMPONENT WILL BE TOPPED BY 15-30KT WLY FLOW ALOFT AND RESULT IN MARGINALLY SUPPORTIVE DEEP LAYER SHEAR FOR UPDRAFT PERSISTENCE/ROTATION...AND PERHAPS SOME HAIL. IN ADDITION...DAMAGING OUTFLOW WINDS WILL BE POSSIBLE FROM STORMS DEVELOPING NEAR THE RESIDUAL FRONT AND MOVING INTO STRONGLY HEATED AND DEEPLY MIXED BOUNDARY LAYER FROM NEB/KS BORDER EWD ACROSS SRN IA/NRN MO. ..SERN TX/SRN LA... TROPICAL MOISTURE AND STRONG HEATING WILL RESULT IN NUMEROUS TSTMS DEVELOPING ACROSS THE GULF COAST AND TX COASTAL PLAIN TODAY. LARGE SCALE ASCENT AND BAND OF ENHANCED CYCLONIC FLOW AROUND LARGE NWWD MOVING MID/UPPER LOW MAY SUPPORT CLUSTERS OF MULTICELL STORMS PRODUCING WET DOWNBURSTS. THE POTENTIAL FOR ISOLATED WATERSPOUTS AND POSSIBLY A BRIEF TORNADO SHOULD ALSO CONTINUE. ...UPPER OH VALLEY/CNTRL APPALACHIANS... INCREASING WARM AIR AND MOISTURE ADVECTION IS FORECAST TO DEVELOP ON THE WRN PERIPHERY OF EAST COAST ANTICYCLONE AND MAY BE FURTHER ENHANCED/CHANNELED IN THE LOW LEVELS ALONG THE WRN SLOPES OF THE CNTRL APPALACHIANS. THIS PROCESS IS EXPECTED TO RESULT IN THE DEVELOPMENT OF STRONG INSTABILITY WITH HEATING OF THE DAY FROM THE TN VALLEY NEWD ACROSS THE UPPER OH VALLEY. ISOLATED TO SCATTERED PULSE STORMS WILL BE POSSIBLE ACROSS MUCH OF THE AREA GIVEN WEAKLY CAPPED AND INCREASINGLY UNSTABLE BOUNDARY LAYER. WEAK HEIGHT FALLS ASSOCIATED WITH THE GREAT LAKES TROUGH WILL ALSO BRUSH THIS REGION AND MAY PROMOTE GREATER STORM COVERAGE/SEVERE POTENTIAL. OVERALL SEVERE THREAT APPEARS LIMITED...HOWEVER...AS RUC FORECAST AND OBSERVED SOUNDINGS THIS MORNING INDICATE RELATIVELY WEAK LAPSE RATES AND MARGINAL DEEP LAYER SHEAR. ...NRN CA/SRN ORE... BELT OF 25-30KT SLY FLOW ON ERN EDGE OF OPENING MID LEVEL WAVE WILL ARRIVE ACROSS NRN CA/SRN ORE COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. THE INCREASE IN SHEAR MAY RESULT IN ISOLATED SEVERE STORMS WITH SOME HAIL/WIND POTENTIAL OVER THESE AREAS INTO THE EVENING HOURS. ..EVANS/GUYER/CARBIN.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 16:37:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 12:37:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061636 SWODY1 SPC AC 061634 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 AM CDT SUN AUG 06 2006 VALID 061630Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM NRN KS TO ERN IA.... ...CENTRAL PLAINS TO MID MS VALLEY THIS AFTERNOON... A SURFACE COLD FRONT...WHICH EXTENDED FROM NW WI TO SE MN/NW IA/SE NEB/NW KS AS OF 15Z...IS MOVING SLOWLY SEWD IN THE WAKE OF A PRONOUNCED SHORTWAVE TROUGH PROGRESSING EWD OVER ONTARIO. A BAND OF MID-UPPER 60S DEWPOINTS PRECEDES THE FRONT ACROSS WI/UPPER MI. HOWEVER...INSTABILITY SHOULD REMAIN RATHER LIMITED THIS AREA DUE TO CLOUDS AND POOR LAPSE RATES...AND FORCING FOR ASCENT WILL BE WEAK IN THE WAKE OF THE MORNING WAVE AND WELL S OF THE ONTARIO TROUGH. THUS...ANY SEVERE STORM THREAT SHOULD ALSO REMAIN MARGINAL THIS AREA. OVERNIGHT CONVECTION IS GRADUALLY WEAKENING OVER SE WI AND NRN IL. THESE STORMS ARE ASSOCIATED WITH A WEAK MID LEVEL SHORTWAVE TROUGH MOVING EWD OVER ERN IA/WI...THOUGH THE CONVECTION SHOULD CONTINUE TO WEAKEN AS IT MOVES INTO A REGION OF WEAK INSTABILITY. AN OUTFLOW BOUNDARY EXTENDS FROM NRN IL INTO CENTRAL IA...WITH A FEED OF UNDISTURBED WARM SECTOR AIR FROM ERN KS/MO INTO SRN IA. THE STRONGER INSTABILITY /MLCAPE VALUES OF 1500-2000 J/KG/ ARE EXPECTED ALONG THE OUTFLOW BOUNDARY AND FRONT FROM NRN KS INTO IA THIS AFTERNOON. THIS AREA REMAINS S OF THE STRONGER MID LEVEL WLYS...BUT VERTICAL SHEAR SHOULD BE SUFFICIENT FOR ORGANIZED MULTICELL CLUSTERS AND PERHAPS MARGINAL SUPERCELL TYPE STORMS. ISOLATED DAMAGING WINDS AND MARGINALLY SEVERE HAIL SHOULD BE THE MAIN SEVERE THREATS THIS AFTERNOON/EVENING. ...NW GULF COAST REGION... THE MID LEVEL TROUGH IN THE ELYS CONTINUES TO MOVE OVER LA/NW GULF TOWARD SE TX. REGIONAL 12Z SOUNDINGS SUGGEST THAT THE DOWNBURST POTENTIAL HAS BEEN REDUCED COMPARED TO THE PREVIOUS TWO DAYS ACROSS THE GULF COAST...GIVEN LESSER CAPE VALUES AND MODEST LOW-LEVEL LAPSE RATES. WHILE ISOLATED DAMAGING WINDS WILL STILL BE POSSIBLE...THE OVERALL SEVERE STORM THREAT APPEARS TOO MARGINAL TO WARRANT MAINTAINING A SLIGHT RISK. ..THOMPSON/TAYLOR.. 08/06/2006  From swody1 at goshenarc.org Sun Aug 6 19:52:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 15:52:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 061952 SWODY1 SPC AC 061950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SUN AUG 06 2006 VALID 062000Z - 071200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS AND UPPER MIDWEST... ...CNTRL PLAINS/UPPER MIDWEST... A LARGE AREA OF UPPER-LEVEL HIGH PRESSURE CURRENTLY EXTENDS EWD FROM THE CNTRL PLAINS ACROSS THE MID MS VALLEY. AT THE SFC...A COLD FRONT EXISTS FROM NRN KS EXTENDING NEWD INTO CNTRL IA. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE 60S AND LOWER 70S F RESULTING IN MODERATE TO STRONG INSTABILITY. THUNDERSTORMS ARE INCREASING IN COVERAGE ACROSS NRN KS AND SERN NEB AND THIS TREND SHOULD CONTINUE THROUGH THE LATE AFTERNOON WITH CONVECTION SPREADING ENEWD INTO SRN IA. ALTHOUGH OBJECTIVE ANALYSIS SHOWS SHEAR PROFILES MARGINAL FOR SUPERCELLS...VERTICAL SHEAR APPEARS SUFFICIENT FOR SEVERE MULTICELLS. LAPSE RATES ARE VERY STEEP EXCEEDING 8.0 C/KM ACROSS MUCH OF THE WARM SECTOR WHICH COMBINED WITH THE STRONG INSTABILITY WILL MAKE HAIL AND ISOLATED WIND DAMAGE A POSSIBILITY WITH THE STRONGER CELLS THIS AFTERNOON. ...EAST TX/WRN LA/ERN OK/WRN OZARKS... LATEST WATER VAPOR IMAGERY SHOWS A WWD MOVING WAVE OVER THE NWRN GULF OF MEXICO. NUMEROUS THUNDERSTORMS ARE ONGOING ACROSS THE REGION LOCATED MAINLY ALONG BANDS OF LARGE-SCALE ASCENT ASSOCIATED WITH THE WAVE. OBJECTIVE ANALYSIS CURRENTLY SHOWS MODERATE INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES ACROSS MUCH OF THE REGION. THIS SHOULD BE SUFFICIENT FOR STRONG MULTICELL AND/OR PULSE THUNDERSTORMS CAPABLE OF STRONG WIND GUSTS THIS AFTERNOON. ..BROYLES.. 08/06/2006  From swody1 at goshenarc.org Mon Aug 7 00:40:31 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 06 Aug 2006 20:40:31 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 070040 SWODY1 SPC AC 070038 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT SUN AUG 06 2006 VALID 070100Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MO RIVER VALLEY... MASS OF DEEP CONVECTION PRECEDES SYNOPTIC FRONTAL ZONE FROM ERN NEB/SWRN IA TO NERN KS AND NWRN MO THIS EVENING. COLD POOL FROM THIS CONVECTION HAS SPREAD OUT TO THE SOUTH AND EAST AND APPEARS TO BE PROMOTING ADDITIONAL TSTM DEVELOPMENT IN HOT AND STRONGLY UNSTABLE AIR MASS. THREAT FOR ISOLATED HAIL AND SCATTERED DAMAGING DOWNBURST WINDS WILL PERSIST FOR AT LEAST A COUPLE MORE HOURS ACROSS THE REGION UNTIL BOUNDARY LAYER STABILIZES FURTHER. ...CNTRL HIGH PLAINS... ROBUST STORMS CONTINUE TO DEVELOP IN REGION OF POST-OUTFLOW ASCENT OVER NWRN KS...AS WELL AS IN POST-FRONTAL UPSLOPE ENVIRONMENT FROM ERN CO TO NERN WY. DEEP LAYER ASCENT ACROSS THIS REGION MAY BE FURTHER ENHANCED BY A WEAK SHORT WAVE TROUGH SPREADING EAST ACROSS NERN CO. GIVEN MODEST INSTABILITY AND SHEAR...ISOLATED SEVERE STORMS WITH WIND AND HAIL COULD PERSIST ACROSS THESE AREAS THIS EVENING. ...SERN TX... CLUSTERS OF TSTMS WILL CONTINUE WITHIN VERY MOIST AND MODERATELY UNSTABLE REGIME ACROSS THE UPPER TX GULF COAST AND COASTAL PLAIN. THIS CONVECTION APPEARS TO BE AIDED BY SLOW MOVING MID/UPPER WAVE DEVELOPING NWWD FROM THE GULF. DEEP LAYER CYCLONIC FLOW AND LIFT FROM THE UPPER WAVE MAY SUSTAIN MORE WIDESPREAD DEEP CONVECTION OVER THE REGION INTO THE NIGHT WITH SOME POTENTIAL FOR ISOLATED WET DOWNBURSTS. ...SRN CASCADES... STRONG TO ISOLATED SEVERE STORMS HAVE ERUPTED OVER THE SISKIYOU MOUNTAINS AND SRN CASCADES LATE THIS AFTERNOON. THIS OROGRAPHICALLY FORCED ACTIVITY APPEARS TO BE FURTHER SUPPORTED BY BROADLY DIFFLUENT MID LEVEL FLOW AHEAD OF UPPER LOW EDGING NEWD TOWARD THE NRN CA COAST. DESPITE LIMITED MOISTURE...STEEP LAPSE RATE ENVIRONMENT AND SUFFICIENT FORCING SHOULD CONTRIBUTE TO A CONTINUED POTENTIAL FOR A HAIL/WIND EVENT OR TWO OVER THE NEXT FEW HOURS. ..CARBIN.. 08/07/2006  From swody1 at goshenarc.org Sat Aug 12 00:57:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 11 Aug 2006 20:57:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120057 SWODY1 SPC AC 120056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT FRI AUG 11 2006 VALID 120100Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN/CNTRL PLAINS... ...NRN/CNTRL PLAINS... SCATTERED SUPERCELLS HAVE INCREASED IN AREAL COVERAGE AHEAD OF UPPER TROUGH FROM SERN SASKATCHEWAN...SWD INTO NWRN SD...WITH MORE ISOLATED ACTIVITY OVER NCNTRL NEB/SCNTRL SD. EARLY EVENING SOUNDINGS AND DIAGNOSTIC DATA EXHIBIT A DEEP MIXED BOUNDARY LAYER ACROSS THE HIGH PLAINS TO THE WEST OF THE ONGOING CONVECTION...THROUGH 550MB AT RAP...WITH SIGNIFICANT INSTABILITY DOWNSTREAM ACROSS THE MOIST SECTOR...COINCIDENT WITH THUNDERSTORM ACTIVITY. WITH LOSS OF DAYTIME HEATING IT APPEARS BOUNDARY LAYER WILL DECOUPLE AS CAP BEGINS TO STRENGTHEN THIS EVENING. LLJ SHOULD PROVE INSTRUMENTAL IN MAINTAINING OVERNIGHT CONVECTION...ESPECIALLY ACROSS ND. GIVEN THE POSITION OF THE UPPER TROUGH...WELL UPSTREAM OVER THE NRN ROCKIES...IT APPEARS LOW LEVEL WARM ADVECTION WILL AID CONVECTIVE CLUSTERING AND POSSIBLE MCS DEVELOPMENT THAT SHOULD SHIFT EWD TOWARD THE RED RIVER REGION OF NWRN MN BY THE END OF THE PERIOD. LARGE HAIL AND DAMAGING WINDS MAY ACCOMPANY THESE STORMS THROUGH THE OVERNIGHT HOURS. FARTHER SOUTH...LBS SOUNDING AT 00Z DISPLAYED A SIGNIFICANT AMOUNT OF INSTABILITY THIS EVENING...MLCAPE IN EXCESS OF 2200 J/KG. SEVERE SUPERCELL STRUCTURES THAT ARE ONGOING ACROSS THIS REGION SHOULD STRUGGLE TO SPREAD TOO FAR DOWNSTREAM GIVEN THE LACK OF LARGE SCALE SUPPORT...AND EXPECTED FOCUS OF THE LLJ INTO THE NRN DAKOTAS. WITH LOSS OF HEATING CNTRL PLAINS CONVECTION SHOULD GRADUALLY BECOME ELEVATED AND BACKBUILD INTO STEEPER HEAT PLUME BEFORE WEAKENING LATE THIS EVENING. ..DARROW.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 05:43:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 01:43:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 120544 SWODY1 SPC AC 120542 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1242 AM CDT SAT AUG 12 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN/CNTRL PLAINS INTO THE UPPER MS VALLEY... HEIGHT FALLS ACROSS THE NRN ROCKIES WILL FLATTEN THE RIDGE IN PLACE ACROSS THE NRN PLAINS LATER TODAY. AS UPPER TROUGH SHIFTS EWD ACROSS ID/MT IT SHOULD FORCE A WEAK DISTURBANCE LOCATED OVER UT NEWD INTO SD BY 00Z...ENHANCING DEEP LAYER SHEAR ALONG AN ELONGATED ZONE OF TIGHTENING LOW LEVEL CONFLUENCE FROM THE NEB PANHANDLE INTO ERN ND/NWRN MN. THIS LOW LEVEL BOUNDARY WILL SERVE AS THE FOCUS FOR EPISODIC CONVECTIVE EVENTS DURING THE DAY1 PERIOD. LATEST THINKING IS SCATTERED THUNDERSTORM ACTIVITY WILL BE ONGOING EARLY IN THE PERIOD WITHIN WARM ADVECTION ZONE ACROSS THE ERN DAKOTAS/MN AS LLJ FEEDS ONGOING ELEVATED CONVECTION. ALTHOUGH THIS ACTIVITY MAY PRODUCE ISOLATED HAIL OR GUSTY WINDS...IT APPEARS STRONGER ACTIVITY WILL EVOLVE LATER IN THE DAY AS BOUNDARY LAYER HEATS ALONG WIND SHIFT. FAVORABLE LOW LEVEL TRAJECTORIES WILL MAINTAIN MORE THAN SUFFICIENT MOISTURE ACROSS THE NRN/CNTRL PLAINS FOR RENEWED THUNDERSTORM DEVELOPMENT BY 21Z...ESPECIALLY GIVEN THE ADDED ASCENT AHEAD OF EJECTING CNTRL ROCKIES SHORTWAVE TROUGH. WITH STRENGTHENING VERTICAL SHEAR PROFILES IT APPEARS SUPERCELL STRUCTURES ARE POSSIBLE...ESPECIALLY EARLY IN THE AFTERNOON CONVECTIVE CYCLE. THE ENTIRE FRONTAL ZONE MAY CONVECT QUICKLY AND EXPAND LINEARLY NEWD FROM CO INTO MN BY 00Z. LATEST FORECAST SOUNDINGS SUGGEST AN ENHANCED SUPERCELL THREAT MAY EXIST AHEAD OF WEAK SFC LOW FROM ERN SD INTO WCNTRL MN BETWEEN 21Z-03Z. THIS SFC FEATURE APPEARS CORRELATED WITH EJECTING SHORTWAVE WHICH COULD RESULT IN A FEW TORNADOES BEFORE STORM MERGERS AND MULTI-CELL CLUSTERS BECOME DOMINATE. OTHERWISE...SUFFICIENT MOISTURE/INSTABILITY WILL LINGER WITHIN POST FRONTAL REGIME ACROSS THE NRN PLAINS FOR AN ELEVATED ANA-TYPE CONVECTIVE EVENT TO DEVELOP ACROSS PORTIONS OF SD/ND LATER IN THE EVENING HOURS...AIDED BY MAIN UPPER TROUGH THAT APPROACHES AFTER DARK. LARGE HAIL SHOULD BE THE PRIMARY SEVERE RISK ACROSS THE SLIGHT RISK REGION. ...ELSEWHERE... STATIONARY...DECAYING FRONTAL ZONE FROM GA...WWD ACROSS THE NRN GULF STATES INTO THE SRN PLAINS WILL FOCUS CONVECTION AGAIN TODAY. VERY MOIST PROFILES AND WEAK TROPOSPHERIC FLOW MAY ENHANCE LOCAL WET MICROBURSTS...HOWEVER ORGANIZED DAMAGING WIND THREAT WILL PROVE TOO DIFFICULT TO PREDICT THIS EARLY IN THE CONVECTIVE PERIOD. ..DARROW/TAYLOR.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 12:37:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 08:37:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121237 SWODY1 SPC AC 121236 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 AM CDT SAT AUG 12 2006 VALID 121300Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHEAST CO ACROSS MUCH OF THE NORTHERN PLAINS INTO MN... LARGE UPPER RIDGE WILL REMAIN OVER THE SOUTHERN HALF OF THE NATION TODAY...WHILE STRONG TROUGH ROTATES EASTWARD ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS. UPPER FORCING WILL OVERSPREAD A MOIST AND VERY UNSTABLE AIRMASS ACROSS THE DAKOTAS/MN/NEB THIS AFTERNOON...POTENTIALLY SETTING THE STAGE FOR A MORE ORGANIZED SEVERE THUNDERSTORM EVENT FROM EASTERN SD INTO WESTERN MN. ...NORTHERN PLAINS... SURFACE COLD FRONT IS ANALYZED THIS MORNING FROM CENTRAL ND INTO EASTERN WY. THIS BOUNDARY WILL MOVE SLOWLY EASTWARD ACROSS THE DAKOTAS THIS AFTERNOON...WHILE SOUTHERLY LOW LEVEL WINDS AHEAD OF FRONT MAINTAIN AMPLE MOISTURE/INSTABILITY. SURFACE TEMPERATURES IN THE 90S AND DEWPOINTS NEAR 70F WILL YIELD AFTERNOON MLCAPE VALUES OVER 3000 J/KG. CAPPING INVERSION WILL BE QUITE STRONG ACROSS THIS REGION THROUGH THE MORNING...BUT IS EXPECTED TO WEAKEN RAPIDLY DURING THE AFTERNOON AS UPPER TROUGH APPROACHES. BY 21Z...RUC/NAM FORECAST SOUNDINGS INDICATE AN ENVIRONMENT QUITE FAVORABLE FOR SUPERCELL STORMS CAPABLE OF VERY LARGE HAIL AND DAMAGING WINDS. LCL HEIGHTS MAY BE A LITTLE HIGH...BUT OTHERWISE LOW LEVEL SHEAR MAY ALSO BE SUFFICIENT FOR ISOLATED TORNADOES. ACTIVITY SHOULD SPREAD INTO MN DURING THE EVENING WITH A CONTINUED SEVERE THREAT. ...NEB/CO... FULL SUNSHINE IS EXPECTED FROM EASTERN CO INTO PARTS OF NEB TODAY...ALLOWING AIR MASS TO BECOME HOT AND MODERATELY UNSTABLE. FORECAST SOUNDINGS SHOW A DEEP...MIXED BOUNDARY LAYER CONDUCIVE TO LOCALLY DAMAGING WINDS IN STRONGER CELLS. ACTIVITY IS EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF CENTRAL CO AND SPREAD NORTHEASTWARD INTO WESTERN NEB BEFORE WEAKENING TONIGHT. MARGINAL DEEP LAYER VERTICAL SHEAR SUGGESTS STORMS WILL BE RATHER DISORGANIZED AND LIMITED. ...SOUTHEAST... ANOTHER DAY OF HOT...HUMID CONDITIONS ARE EXPECTED TODAY ALONG AND SOUTH OF MAIN FRONTAL BOUNDARY FROM EAST TX INTO GA/SC. THESE STORMS ARE LIKELY TO BE DISORGANIZED AND CAPABLE OF ONLY BRIEF SEVERE WINDS. ACTIVITY SHOULD DIMINISH RAPIDLY AFTER MIDNIGHT. ..HART/TAYLOR.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 16:14:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 12:14:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 121614 SWODY1 SPC AC 121612 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1112 AM CDT SAT AUG 12 2006 VALID 121630Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN CO ACROSS NRN PLAINS INTO MN... ...SYNOPSIS... WHILE RIDGING PREVAILS S OF 40N THE LARGE SCALE TROUGH WRN CANADA INTO PAC NW WILL SHIFT EWD ACROSS NRN ROCKIES INTO NRN HIGH PLAINS BY 12Z SUN. S/WV ENERGY ROTATING THRU THE TROUGH CURRENTLY CROSSING ID AND WRN MT WILL REACH HIGH PLAINS LATE TONIGHT. PRECEEDING THE TROUGH A PLUME OF DEEP MONSOON MOISTURE IS SPREADING NEWD FROM CENTRAL ROCKIES ACROSS THE NRN PLAINS TODAY. AT THE SURFACE COLD FRONT CURRENTLY ACROSS WRN DAKOTAS AND THEN WSWWD INTO SWRN WY AND NRN UT WILL ONLY SHIFT SLOWLY EWD THRU THE AFTERNOON AS UPPER SUPPORT STILL WELL TO THE W. 30-40KT SLY LOW LEVEL JET E OF FRONT CONTINUES TO PROVIDE A MOIST AND POTENTIALLY VERY UNSTABLE AIR MASS NWD TO CANADIAN BORDER. ...NRN PLAINS... THE COMBINATION OF WARM MID LEVEL TEMPERATURES AND THE MONSOON PLUME OF MOISTURE WILL DELAY INITIATION OF SURFACE BASED SEVERE THUNDERSTORMS UNTIL LATER THIS AFTERNOON/EVENING MUCH OF NRN PLAINS AREA ALONG AND E OF COLD FRONT. SUFFICIENT ELEVATED INSTABILITY AND SHEAR FOR MORE ISOLATED LARGE HAIL THIS AFTERNOON PRIOR TO THE EXPECTED MORE INTENSE DEVELOPMENT ONCE CAP HAS ERODED. HOWEVER WITH DEWPOINTS MID 60S TO 70 F AND POTENTIAL FOR SURFACE TEMPERATURES RISING THRU THE 90S F...CAP SHOULD WEAKEN SUFFICIENTLY FOR SEVERE THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF COLD FRONT CENTRAL ND/SD BY LATER THIS AFTERNOON. WITH DEEP LAYER SHEAR OF 30-40KT COUPLED WITH MLCAPES INCREASING TO 2500...SUPERCELLS ARE LIKELY. VERY LARGE HAIL WILL BE PRIMARY THREAT WITH ANY SUPERCELL...HOWEVER SUFFICIENT LOW LCL/S ERN DAKOTAS/WRN MN BY LATE THIS AFTERNOON FOR POSSIBLE TORNADOES AS WELL. ...NERN CO INTO NEB... STRONG HEATING AND WEAKER SHEAR THIS AREA WILL RESULT IN A DEEPLY MIXED BOUNDARY LAYER BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP INITIALLY OVER HIGH TERRAIN AND IN CONVERGENCE ALONG COLD FRONT...THEN PROPAGATE E/NE THRU THE EVENING. PRIMARY THREAT GIVEN THE EXPECTED STEEP LAPSE RATES AND HIGH BASES WILL BE DAMAGING WINDS. ANY SEVERE HAIL WILL BE ASSOCIATED WITH ISOLATED SUPERCELLS THAT COULD FORM PRIOR TO NIGHTFALL. ..HALES/JEWELL.. 08/12/2006  From swody1 at goshenarc.org Sat Aug 12 20:00:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 16:00:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 122001 SWODY1 SPC AC 121959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0259 PM CDT SAT AUG 12 2006 VALID 122000Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL/NRN PLAINS TO THE UPPER MS VLY... ...NRN/CNTRL PLAINS TO THE UPPER MS VLY... TSTMS CONTINUE TO GRADUALLY INTENSIFY ALONG/AHEAD OF A PRE-FRONTAL TROUGH COINCIDENT WITH A LOW-LEVEL THERMAL RIDGE FROM CNTRL SD SWD INTO NERN CO THIS AFTN. 2-6KM SHEAR VECTORS HAVE HAD A BACKING TENDENCY AHEAD OF THE DIGGING PAC NW TROUGH...NOW ALIGNED PARALLEL TO THE INITIATING BOUNDARY. THIS SUGGESTS THAT STORMS WILL EVOLVE PRIMARILY INTO LINE SEGMENTS. VERTICAL SHEAR WAS STRONGEST ACROSS THE INTERNATIONAL BORDER AND ACROSS THE NRN HIGH PLAINS...BUT MARGINALLY SUFFICIENT FOR PERHAPS A BRIEF SUPERCELL. PRESENT INDICATIONS ARE THAT THE STORMS WILL SLOWLY INTENSIFY ACROSS CNTRL/ERN SD SWD INTO CNTRL NEB THROUGH THE EVENING OWING TO STEEP LOW-LEVEL LAPSE RATES. H7-H5 LAPSE RATES HAVE BEEN TEMPERED BY INFLUX OF MONSOONAL MOISTURE ALOFT ON THE SUB-TROPICAL CONVEYOR AND SHOULD LIMIT HAIL SIZE TO LESS THAN 2 INCHES. DAMAGING WINDS WILL BE A THREAT AS STORMS DEVELOP INTO SMALL SCALE BOWS. FURTHERMORE...THOUGH STORM EVOLUTION INTO A MORE LINEAR MODE WILL TEND TO LIMIT THREAT FOR SUSTAINED LOW-LEVEL ROTATION...ISOLD TORNADOES ARE PSBL ACROSS THE ERN DAKS/WRN MN WHERE THE BOUNDARY LAYER FLOW REMAINS BACKED AHEAD OF A 1003 MB SFC-LOW OVER CNTRL SD. HERE...LCLS ARE LOWER OWING TO SLIGHTLY COOLER TEMPERATURES AND AMPLY MOIST BOUNDARY LAYER. ACTIVITY WILL GRADUALLY SPREAD ENEWD INTO ERN SD...WRN MN AND NERN NEB OVERNIGHT WITH PERHAPS DAMAGING WINDS. FARTHER N...GLANCING INFLUENCE OF A LEAD MID-LEVEL SHORTWAVE TROUGH MOVING INTO SRN MANITOBA HAS CONTRIBUTED TO A GRADUAL INCREASE IN ELEVATED TSTMS ALONG/N OF THE PRIMARY COLD FRONT FROM NWRN ONTARIO...SERN MANITOBA INTO CNTRL ND. THIS REGION IS SITUATED JUST N OF THE SUB-TROPICAL MOIST PLUME AND MID-LEVEL TEMPERATURES ARE NOT AS WARM AS FARTHER S. CLOUDS DOWNSTREAM FROM THE ACTIVITY WILL TEND TO LIMIT SFC-BASED EVOLUTION...BUT ACTIVITY WILL LIKELY BUILD SWWD ALONG THE FRONT TOWARD SWRN ND LATER THIS AFTN. LARGE HAIL WILL BE THE PRIMARY THREAT WITH THIS ACTIVITY AS IT MOVES ENEWD INTO FAR NWRN MN/LAKE OF THE WOODS LATER THIS EVENING/OVERNIGHT. ...NRN/CNTRL ROCKIES/HIGH PLAINS... PRIMARY TROUGH AXIS NOW OVER ERN ORE AND ID WILL EJECT ENEWD INTO THE NRN/CNTRL HIGH PLAINS TONIGHT. TSTMS WILL BE INCREASING THIS EVENING ACROSS PORTIONS OF SRN MT AND WY IN ADVANCE OF THIS SYSTEM. ACTIVITY WILL MOVE NEWD ONTO THE ADJACENT HIGH PLAINS OVERNIGHT. LOW-LEVEL MOISTURE WILL BE SOMEWHAT LIMITED...BUT LARGE TEMP/DEW POINT SPREADS AND COLDER AIR ALOFT FILTERING INTO THE REGION MAY SUPPORT ISOLD GUSTY WINDS/HAIL. ..RACY.. 08/12/2006  From swody1 at goshenarc.org Sun Aug 13 00:55:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 12 Aug 2006 20:55:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130055 SWODY1 SPC AC 130053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT SAT AUG 12 2006 VALID 130100Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/NRN PLAINS TO THE UPPER MS VALLEY... LARGE SCALE ASCENT APPEARS TO BE OVERSPREADING WRN EDGE OF DEEP MOIST PLUME IN PLACE ACROSS THE CNTRL/NRN HIGH PLAINS...PER RECENT EXPANDING MID LEVEL CLOUDINESS FROM NERN CO INTO SWRN SD. ADDITIONALLY...A BROKEN LINE OF THUNDERSTORMS HAS FORMED AHEAD OF MAIN SHORTWAVE FROM SERN MT INTO NWRN CO COINCIDENT WITH INCREASING ZONE OF ASCENT...PRODUCING ISOLATED SEVERE WIND GUSTS AT TIMES OVER THE HIGHER TERRAIN OF WY. WITH TIME...UPDRAFTS WILL INTERACT WITH MOIST BOUNDARY LAYER DOWNSTREAM WHICH MAY ALLOW FOR AN EXPANDING LINE OF THUNDERSTORMS FROM NWRN NEB INTO WRN SD/SCNTRL ND ALONG MAIN FRONTAL ZONE. HAIL AND GUSTY WINDS SHOULD ACCOMPANY THIS ACTIVITY AS IT SPREADS EWD DURING THE OVERNIGHT HOURS. DOWNSTREAM...AN ELONGATED MCS HAS EVOLVED FROM ERN SD INTO WCNTRL MN WITHIN DEEP MID-HIGH LEVEL MOIST PLUME THAT EXTENDS INTO LOW LATITUDE REGIONS OF THE SWRN U.S./NWRN MEXICO. THIS ACTIVITY IS SHIFTING SLOWLY EWD AHEAD OF LEAD SPEED MAX/SHORTWAVE THAT EJECTED ACROSS THE CNTRL ROCKIES EARLY THIS MORNING. LAPSE RATES ARE NOT PARTICULARLY STEEP ACROSS THIS REGION...WITH SUBSTANTIAL INHIBITION NOTED AT BOTH MPX AND OMA ON 00Z SOUNDINGS THIS EVENING. ALTHOUGH DEEP LAYER SHEAR CERTAINLY SUPPORTS STORM ROTATION...CURRENT STORM MODE WOULD SUGGEST ACTIVITY WILL MAINTAIN ITS MCS-TYPE CHARACTER AS IT SPREADS INTO SWRN PORTIONS OF MN. ..DARROW.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 05:52:16 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 01:52:16 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 130552 SWODY1 SPC AC 130551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT SUN AUG 13 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES TO THE CENTRAL PLAINS... PRECIPITABLE WATER VALUES WILL REMAIN HIGH ACROSS THE MID SECTION OF THE U.S. SUNDAY AIDED BY MOIST MID-HIGH LEVEL TRAJECTORIES ACROSS THE SWRN U.S. INTO THE CNTRL PLAINS...WHILE SELY CONFLUENT BOUNDARY LAYER FLOW PERSISTS ALONG WRN EDGE OF OH VALLEY ANTICYCLONE. THIS MOIST REGIME WILL UNDOUBTEDLY PROVIDE SUFFICIENT INSTABILITY FOR RENEWED DAYTIME CONVECTION AHEAD OF ADVANCING COLD FRONT FROM THE SRN/CNTRL ROCKIES INTO THE GREAT LAKES REGION. EARLY MORNING WATER VAPOR IMAGERY IS NOT PARTICULARLY HELPFUL DEPICTING POTENTIAL DISTURBANCES EMBEDDED WITHIN TROPICAL CONNECTION FROM THE LOWER LATITUDES IN THE SWRN U.S. AS A RESULT...DAYTIME HEATING SHOULD PROVE INSTRUMENTAL IN POTENTIAL SEVERE DEVELOPMENT. LATE EVENING MODEL GUIDANCE SUGGEST AN AXIS OF STEEP LOW LEVEL LAPSE RATES WILL DEVELOP/SPREAD NEWD AHEAD OF SFC BOUNDARY ACROSS KS INTO WRN IA BY EARLY AFTERNOON. THIS SHOULD ENHANCE INSTABILITY ALONG SRN FRINGE OF STRONGER WLY FLOW/ZONE OF MID LEVEL HEIGHT FALLS IN ADVANCE OF NRN PLAINS TROUGH. ALTHOUGH SCATTERED THUNDERSTORMS MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ALONG FRONTAL ZONE...IT APPEARS MUCH OF THIS ACTIVITY MAY ACTUALLY BE POST WIND SHIFT. MOIST BOUNDARY LAYER CONVECTION SHOULD EVOLVE BY 20Z ALONG/AHEAD OF COLD FRONT...SHIFTING EWD INTO THE UPPER GREAT LAKES BY EARLY EVENING...ARCING SWWD INTO KS WHERE VERTICAL SHEAR WILL BE QUITE WEAK. FORECAST SOUNDINGS FOR THE MID MS VALLEY SUGGEST SUPERCELLS ARE POSSIBLE EARLY IN THE CONVECTIVE MODE...THEN LIKELY MATURE INTO FORCED BANDS OF STRONG/SEVERE CONVECTION THAT MAY GENERATE LOCALLY DAMAGING WINDS AS THEY MOVE DOWNSTREAM DURING THE EVENING HOURS. ...ELSEWHERE... DECAYING FRONTAL ZONE FROM THE SERN U.S. INTO THE SRN PLAINS WILL ONCE AGAIN AID ISOLATED-SCATTERED THUNDERSTORM DEVELOPMENT BY MID AFTERNOON. ASIDE FROM LOCALLY STRONG WINDS AND HEAVY RAIN THIS ACTIVITY SHOULD REMAIN RATHER BENIGN. ..DARROW/TAYLOR.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 12:48:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 08:48:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131248 SWODY1 SPC AC 131247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0747 AM CDT SUN AUG 13 2006 VALID 131300Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN KS/NEB INTO THE WESTERN GREAT LAKES REGION... ...MN/IA/WI/MI... MORNING WATER VAPOR IMAGERY SHOWS UPPER TROUGH MOVING ACROSS EASTERN MT/WY INTO THE NORTHERN PLAINS. AHEAD OF THIS TROUGH...WEAKER EMBEDDED FEATURES ARE INDICATED BY MODEL GUIDANCE OVER PARTS OF SD/NEB...ALTHOUGH THEY ARE HARDER TO IDENTIFY IN SATELLITE IMAGERY. THUNDERSTORMS HAVE PERSISTED OVERNIGHT AHEAD OF THESE FEATURES... RESULTING IN WIDESPREAD CLOUDS FROM SD/NEB/KS INTO MN/IA. THIS SHOULD LIMIT DAYTIME HEATING AND DESTABILIZATION ACROSS THE MIDWEST TODAY. AFTERNOON MAX TEMPERATURES IN THE LOW/MID 80S...COUPLED WITH SURFACE DEWPOINTS IN THE 60S...WILL YIELD MLCAPE VALUES OF 1000-1500 J/KG FROM MN/IA EASTWARD INTO THE WESTERN GREAT LAKES. DESPITE ONLY MODERATE INSTABILITY...VERTICAL SHEAR PROFILES WILL BE QUITE STRONG AS SOUTHERN FRINGE OF STRONG UPPER LEVEL JET OVERSPREADS REGION. THUNDERSTORMS ARE LIKELY TO INTENSIFY THIS AFTERNOON OVER MN/IA AHEAD OF SURFACE LOW/COLD FRONT...WITH A THREAT OF LARGE HAIL AND DAMAGING WINDS IN STRONGER CELLS. THIS ACTIVITY WILL LIKELY DEVELOP EASTWARD ACROSS PARTS OF WI AND UPPER MI BEFORE WEAKENING THIS EVENING. ...EASTERN NEB/KS/NORTHERN MO... STRONGER DAYTIME HEATING IS ANTICIPATED SOUTH AND WEST OF AFOREMENTIONED AREA...WITH TEMPERATURES LIKELY TO CLIMB WELL INTO THE 90S FROM EASTERN NEB INTO PARTS OF KS/MO. SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG COLD FRONT AS IT MOVES INTO REGION THIS AFTERNOON/EVENING. MID LEVEL WIND FIELDS AND VERTICAL SHEAR PROFILES WILL BE MUCH WEAKER IN THIS AREA THAN FARTHER NORTHEAST. HOWEVER...DEGREE OF INSTABILITY AND DEEP-MIXED BOUNDARY LAYER WILL PROMOTE A RISK OF DAMAGING WINDS IN STRONGER CELLS. ..HART/TAYLOR.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 15:58:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 11:58:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131559 SWODY1 SPC AC 131557 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1057 AM CDT SUN AUG 13 2006 VALID 131630Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM KS/ERN NEB ACROSS IA INTO SRN MN/SWRN WI... ...KS/ERN NEB ACROSS IA INTO SRN MN/SWRN WI... A RATHER VIGOROUS S/WV TROUGH WILL BE CROSSING THE NRN PLAINS THIS AFTERNOON...REACHING THE UPPER GREAT LAKES BY 12Z MON. SWLY FLOW AHEAD OF TROUGH CONTINUES TO DIRECT MONSOONAL PLUME OF MOIST AIR NEWD ACROSS PLAINS INTO UPPER MS VALLEY. COLD FRONT CURRENTLY MOVING EWD EXTENDS FROM CENTRAL DAKOTAS/NEB INTO NERN CO. A SURFACE TROUGH PRECEDES THE FRONT ACROSS WRN KS TO NERN NM WITH WARM AND ONLY MODESTLY STEEP MID LEVEL LAPSE RATES IN ADVANCE OF THE COLD FRONT THAT IS MOVING EWD ACROSS CENTRAL DAKOTAS/NEB TODAY...SEVERE THUNDERSTORMS WILL REQUIRE STRONG SURFACE HEATING FOR INITIATION. BASED ON CURRENT TEMP AND CLOUD COVER TRENDS...HEATING WILL BE SUFFICIENT FOR DEVELOPMENT OF SURFACE BASED THUNDERSTORMS AHEAD OF COLD FRONT AND THE SURFACE TROUGH BY MID AFTERNOON. ADDITIONALLY SURFACE TEMPERATURES WILL LIKELY REACH LOW 90S INTO SRN IA WHERE A MORE FAVORABLE SHEAR ENVIRONMENT WILL BE IN PLACE. MLCAPES AOA 2000 J/KG FROM SRN IA SWWD INTO KS WILL SUPPORT DEVELOPMENT OF STRONG/SEVERE THUNDERSTORMS BY MID AFTERNOON. GENERALLY SHEAR OF 20KT OR LESS IN KS WILL FAVOR PULSE/MULTICELLULAR ACTIVITY WITH DOWNBURSTS AND A MARGINALLY SEVERE HAIL THREAT. FURTHER NE ACROSS IA...SHEAR OF 30-40KT WILL CONDITIONALLY SUPPORT SUPERCELLS...PROVIDED SUFFICIENT HEATING/INSTABILITY DEVELOPS. MODELS INDICATE A GOOD MCS SIGNAL BY LATER THIS AFTERNOON/EVENING ACROSS NRN/CENTRAL IA WHICH WOULD LEAD TO A GREATER WIND DAMAGE POTENTIAL. AGAIN AMOUNT OF SURFACE HEATING WILL BE THE CAVEAT AS TO AMOUNT OF SEVERE POTENTIAL AS THE STRONG UVVS WITH THE S/WV TROUGH PASS FURTHER N ACROSS MN INTO UPPER GREAT LAKES WHERE THERMODYNAMICS ARE VERY LIMITED. ..HALES/JEWELL.. 08/13/2006  From swody1 at goshenarc.org Sun Aug 13 19:52:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 15:52:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 131952 SWODY1 SPC AC 131950 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0250 PM CDT SUN AUG 13 2006 VALID 132000Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE UPPER MS VLY SWWD INTO THE CNTRL PLAINS... ...UPPER MS VLY SWD INTO THE CNTRL PLAINS... 19Z SFC ANALYSIS PLACES A TROUGH FROM CNTRL IA SWWD TO A HEAT LOW VCNTY KTOP THEN SWWD INTO WRN KS. A 1010 MB LOW WAS SITUATED VCNTY KFSD WITH A N-S COLD FRONT FROM NCNTRL MN SWWD THROUGH THE LOW TO ECNTRL CO. BOUNDARY LAYER HEATING HAS BEEN STRONGEST AHEAD OF THE PRE-FRONTAL TROUGH FROM SCNTRL IA SWWD ACROSS NWRN MO INTO KS WHERE TEMPERATURES HAVE RISEN TO AOA 90 DEG F AND DEW POINTS HAVE REMAINED 70-75 DEG F. MAJORITY OF THE LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE UPPER TROUGH WAS PASSING WELL N OF THE MOST UNSTABLE WARM SECTOR. THUS... TSTMS WILL BE DRIVEN MOSTLY BY THERMODYNAMIC PROCESSES. THIS SHOULD CONFINE THE MOST VIGOROUS TSTM DEVELOPMENT ALONG THE SERN EDGE OF CURRENT CONVECTION...NAMELY FROM SCNTRL IA SWWD INTO EXTREME SERN NEB...NWRN MO AND NRN/CNTRL KS. BULK SHEAR WAS GENERALLY 35-40 KTS IN THIS REGION AND MID-LEVEL LAPSE RATES BLO 6 DEG C/KM. BUT... GIVEN PRESENCE OF A HOT AND MOIST BOUNDARY LAYER AND GENERALLY UNIDIRECTIONAL WSWLY FLOW ALOFT...STORMS WILL LIKELY DEVELOP INTO SHORT LINE SEGMENTS GIVING DAMAGING WINDS. FURTHERMORE...A BRIEF ISOLD TORNADO MAY OCCUR...MAINLY ACROSS EXTREME SCNTRL IA/NCNTRL MO WHERE OUTFLOW BOUNDARY INTERSECTIONS MAY AUGMENT LOW-LEVEL HELICITY. ACTIVITY SHOULD MOVE ENEWD INTO/ACROSS THE UPPER MS VLY AND PARTS OF NRN MO OVERNIGHT...BUT LIKELY WEAKEN AS BUOYANCY DECREASES WITH ONSET OF NOCTURNAL COOLING. A FEW TSTMS MAY DEVELOP VCNTY THE SFC LOW/COLD FRONT ACROSS SERN SD INTO SWRN MN AND SWD ACROSS NWRN IA...NERN NEB LATER THIS AFTN. THIS REGION HAS HAD SOME AIR MASS RECOVERY COINCIDENT WITH MASS CONVERGENCE. OTHER THAN ISOLD HAIL/GUSTY WINDS...NO WIDESPREAD SVR TSTMS ARE EXPECTED HERE. FARTHER N...CLOUDS/POOR LAPSE RATE ENVIRONMENT WILL BE NEGATIVE FACTORS FOR SUSTAINED DEEP MOIST CONVECTION FROM MN/WI NWD INTO THE GRTLKS REGION. ..RACY.. 08/13/2006  From swody1 at goshenarc.org Mon Aug 14 00:58:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 13 Aug 2006 20:58:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140057 SWODY1 SPC AC 140056 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 PM CDT SUN AUG 13 2006 VALID 140100Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NE KS...NRN MO...SE IA AND WRN IL... ...MID MS VALLEY/CNTRL PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A WELL-DEVELOPED UPPER-LEVEL TROUGH OVER MANITOBA EXTENDING SWD INTO THE NRN PLAINS. ALTHOUGH HARDER TO IDENTIFY...A LEAD SHORTWAVE TROUGH LIKELY EXISTS ACROSS THE NRN MS VALLEY EXTENDING SWWD INTO THE CNTRL PLAINS ALONG THE ERN EDGE OF A PLUME OF MID-LEVEL MOISTURE. THE LARGE LINEAR MCS ONGOING IN SE IA...NRN MO AND NE KS IS LIKELY BEING SUPPORTED BY LARGE-SCALE ASCENT JUST AHEAD OF THE LEAD SHORTWAVE TROUGH. AS THE MCS TRACKS EWD ACROSS NE MO AND WRN IL...SFC DEWPOINTS IN THE UPPER 60S/LOWER 70S F AND MODERATE INSTABILITY SHOULD SUPPORT THE LINE OF THUNDERSTORMS THROUGH LATE EVENING. THE PROFILER AT LATHROP MO CURRENTLY SHOWS A 0-6 KM SHEAR VALUE AROUND 25 KT IN NW MO AND THIS AMOUNT OF SHEAR IS FORECAST TO REMAIN PRESENT THROUGH 06Z. THIS SHOULD BE SUFFICIENT FOR SEVERE MULTICELL THUNDERSTORMS IN NE MO AND WRN IL. AS INSTABILITY DECREASES...THE SEVERE THREAT SHOULD BECOME MORE ISOLATED WITH A GRADUAL DOWNTREND IN STORM INTENSITY OVER THE NEXT 2 TO 3 HOURS. ALTHOUGH HAIL WILL BE POSSIBLE WITH THE STRONGER CELLS...WIND DAMAGE SHOULD BE THE PRIMARY THREAT DUE TO STEEP LOW-LEVEL LAPSE RATES CURRENTLY EXCEEDING 7.0 C/KM EWD INTO THE ST LOUIS AREA. WSWWD ACROSS KS AND NRN OK...LOW-LEVEL LAPSE RATES ARE ALSO STEEP WHICH MAY RESULT IN A FEW MARGINALLY SEVERE STORMS CAPABLE OF STRONG WIND GUSTS FOR 1 TO 2 MORE HOURS. ..BROYLES.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 05:46:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 01:46:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 140545 SWODY1 SPC AC 140544 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT MON AUG 14 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH VALLEY... ...OH VALLEY... AN UPPER-LEVEL TROUGH OVER THE NRN PLAINS WILL DRIFT ESEWD INTO THE GREAT LAKES REGION TODAY AS A COLD FRONT ADVANCES SEWD INTO THE OH VALLEY. SFC DEWPOINTS AHEAD OF THE FRONT SHOULD RANGE FROM AROUND 60 F NEAR LAKE ERIE TO THE LOWER 70S F ACROSS THE MID MS VALLEY. SEVERAL CLUSTERS OF CONVECTION WILL LIKELY BE PRESENT ALONG THE BOUNDARY THIS MORNING. REINTENSIFICATION THIS AFTERNOON SHOULD OCCUR WITH EXISTING CONVECTION AS MODERATE INSTABILITY DEVELOPS AHEAD OF THE FRONT. ADDITIONAL THUNDERSTORMS WILL ALSO LIKELY INITIATE AHEAD OF THE FRONT FROM THE OH VALLEY SWWD INTO THE MID MS VALLEY. THE GREATEST STORM COVERAGE SHOULD OCCUR NEAR THE UPPER-TROUGH ACROSS IND...OH AND NRN KY WHERE LARGE-SCALE ASCENT WILL BE THE STRONGEST. VERTICAL SHEAR AND LIFT WILL LIKELY BE ENHANCED IN THE LATE AFTERNOON AS THE RIGHT ENTRANCE REGION OF A 70 TO 80 KT MID-LEVEL JET MOVES ACROSS THE REGION. FORECAST SOUNDINGS IN IND AND OH THIS AFTERNOON SHOW 0-6 KM SHEAR VALUES IN THE 30 TO 40 KT RANGE WHICH SHOULD BE SUPPORTIVE OF SEVERE MULTICELLS AND POSSIBLY ISOLATED SUPERCELLS WHERE THE INSTABILITY IS LOCALLY MAXIMIZED. THE UNIDIRECTIONAL FLOW WILL BE FAVORABLE FOR ISOLATED WIND DAMAGE ESPECIALLY WITH SHORT-LINE SEGMENTS IN AREAS WITH LOCALLY STEEP LOW-LEVEL LAPSE RATES. ISOLATED LARGE HAIL MAY ALSO ACCOMPANY ANY SUPERCELLS THAT DEVELOP. ...SRN PLAINS... A COLD FRONT IS FORECAST TO BECOME NEARLY STATIONARY FROM WEST TX EXTENDING EWD ACROSS SRN OK INTO CNTRL AR THIS AFTERNOON. NORTH OF THE FRONT...SCATTERED THUNDERSTORMS SHOULD BE ONGOING THIS MORNING WITH ADDITIONAL THUNDERSTORMS LIKELY INITIATING ALONG AND BEHIND THE BOUNDARY THIS AFTERNOON. SFC HEATING AND DEWPOINTS IN THE LOWER TO MID 60S F SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY BY AFTERNOON. NORTH OF THE BOUNDARY LATE THIS AFTERNOON...BACKED LOW-LEVEL FLOW MAY CREATE ENOUGH DEEP LAYER SHEAR FOR A FEW MULTICELL SEVERE THUNDERSTORMS. HOWEVER...ANY SEVERE THREAT SHOULD REMAIN VERY ISOLATED AND CONCENTRATED NEAR PEAK HEATING. THE STRONGEST THUNDERSTORMS MAY BE CAPABLE OF PRODUCING MARGINALLY SEVERE WIND GUSTS AND HAIL. ...HIGH PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH OVER WRN NV. THIS FEATURE IS FORECAST TO MOVE INTO THE CNTRL ROCKIES AND EMERGE INTO THE CNTRL HIGH PLAINS THIS AFTERNOON. LARGE-SCALE ASCENT AHEAD OF THE SHORTWAVE TROUGH SHOULD BE SUPPORTIVE OF ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT. ALTHOUGH VERTICAL SHEAR PROFILES WILL LIKELY BE SUFFICIENT FOR SEVERE STORMS...THE AMOUNT OF INSTABILITY THAT WILL BE IN PLACE THIS AFTERNOON REMAINS IN QUESTION. IF ENOUGH INSTABILITY DEVELOPS...THE SHEAR AND STEEP LAPSE RATES SHOULD SUPPORT AT LEAST A FEW MARGINALLY SEVERE STORMS CAPABLE OF HAIL AND STRONG GUSTY WINDS. ..BROYLES/TAYLOR.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 12:28:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 08:28:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141229 SWODY1 SPC AC 141227 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0727 AM CDT MON AUG 14 2006 VALID 141300Z - 151200Z ...NO SVR TSTM AREAS FORECAST... STRONG UPPER TROUGH CONTINUES TO TRACK EASTWARD ACROSS THE GREAT LAKES REGION THIS MORNING...WITH BROAD UPPER RIDGE REMAINING IN PLACE THROUGHOUT THE SOUTHERN STATES. A WEAKENING COLD FRONT WILL SWEEP SOUTHEASTWARD FROM THE OH VALLEY INTO THE CENTRAL PLAINS...PROVIDING A FOCUS FOR SCATTERED THUNDERSTORMS. OTHER CONVECTION IS EXPECTED TODAY OVER THE CENTRAL HIGH PLAINS...AND OVER PORTIONS OF THE SOUTHWEST STATES. ...OH VALLEY... SURFACE COLD FRONT IS CURRENTLY ANALYZED CENTRAL WI INTO SOUTHERN KS. THIS BOUNDARY IS FORECAST TO SWEEP SOUTHEASTWARD...EXTENDING FROM WESTERN OH INTO SOUTHERN MO BY LATE AFTERNOON. AMPLE MOISTURE AND FRONTAL CONVERGENCE SHOULD PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS ALONG THE LENGTH OF THE FRONT. HOWEVER...STRONGER DEEP LAYER VERTICAL SHEAR WILL RESIDE FROM OH NORTHWARD...WHERE FORECAST SOUNDINGS SUGGEST AOB 1000 J/KG OF CAPE WILL BE PRESENT. FROM THERE SOUTHWARD INTO KY...GREATER DAYTIME HEATING AND HIGHER DEWPOINTS WILL PROMOTE A MODERATELY UNSTABLE AIRMASS. BUT RATHER WEAK VERTICAL SHEAR IS EXPECTED IN THIS REGION. THEREFORE...PRESENT INDICATIONS ARE THAT ORGANIZED/SEVERE THUNDERSTORM COVERAGE WILL BE RATHER LOW TODAY. NEVERTHELESS...GUSTY/DAMAGING WINDS AND PERHAPS HAIL WILL BE POSSIBLE IN STRONGEST CELLS TODAY ALONG THE FRONT. ...AR/OK/TX... HOT...HUMID CONDITIONS ARE EXPECTED TO PERSIST AGAIN TODAY ACROSS THIS REGION WITH TEMPERATURES WELL INTO THE 90S. SCATTERED AFTERNOON THUNDERSTORMS ARE EXPECTED FROM THE TX PANHANDLE ACROSS OK INTO AR...ALONG AND SOUTH OF FRONT. STEEP LOW LEVEL LAPSE RATES AND MODERATE CAPE VALUES WILL PROMOTE A RISK OF LOCALIZED DAMAGING WINDS IN STRONGER CELLS. ...CENTRAL HIGH PLAINS... WATER VAPOR IMAGERY SUGGESTS A WEAK UPPER VORT MAX CURRENTLY OVER WESTERN WY. THIS FEATURE IS FORECAST TO MOVE SLOWLY EASTWARD...AND AFFECT THE FOOTHILLS AND FRONT RANGE OF SOUTHEAST WY/NORTHEAST CO THIS AFTERNOON. SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP OVER THE HIGHER TERRAIN AND MOVE EASTWARD INTO THE NEB PANHANDLE AND SOUTHWEST SD DURING THE EVENING. ISOLATED STORMS IN THIS AREA COULD PRODUCE GUSTY WINDS AND HAIL BEFORE DIMINISHING AFTER SUNSET. ...AZ... NORTHEAST UPPER FLOW PATTERN HAS DEVELOPED OVER AZ TODAY...ON EAST SIDE OF UPPER RIDGE CENTERED NEAR YUM. DEEP MONSOONAL MOISTURE REMAINS IN PLACE OVER EASTERN AZ AND MUCH OF NM...WHERE SCATTERED AFTERNOON THUNDERSTORMS ARE EXPECTED. EAST/NORTHEAST UPPER FLOW MAY ALLOW THIS ACTIVITY TO SPREAD INTO LOWER DESERTS FROM PHX-TUS THIS AFTERNOON AND EVENING. GUSTY/DAMAGING WINDS COULD OCCUR NEAR STRONGER STORMS. ..HART/TAYLOR.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 16:18:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 12:18:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141618 SWODY1 SPC AC 141616 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1116 AM CDT MON AUG 14 2006 VALID 141630Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF ERN WY/NEB PANHANDLE AND SWRN SD... ...SYNOPSIS... PROGRESSIVE TROUGH CONTINUES EWD ACROSS GREAT LAKES TO NERN U.S. THIS FORECAST PERIOD. COLD FRONT ACCOMPANYING TROUGH THIS AM LOCATED FROM LOWER MI SWWD THRU SWRN MO TO SCENTRAL OK THEN WWD TO CENTRAL NM. SURFACE HIGH CENTRAL NEB WILL SHIFT TO LOWER MO VALLEY BY 12Z TUE ALLOWING SELY UPSLOPE FLOW TO PERSIST THE LEE OF CENTRAL ROCKIES. ...ERN WY/NEB PANHANDLE/SWRN SD... CONSISTENT MODEL SIGNAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON IN THE CURRENT UPSLOPE REGIME LEE OF CENTRAL ROCKIES. WITH DEWPOINTS EXPECTED TO HOLD AT 50 F OR HIGHER E OF HIGHER TERRAIN AS FAR N AS ECENTRAL WY...AIR MASS EXPECTED TO BECOME SUFFICIENTLY UNSTABLE TO SUPPORT STRONG/SEVERE THUNDERSTORMS. WITH LAPSE RATES IN EXCESS OF 8C/KM AND VEERING SHEAR PROFILES UPWARDS TO 30KT...PARAMETERS SHOULD BE IN PLACE FOR AT LEAST ISOLATED SUPERCELL DEVELOPMENT VICINITY NEB/WY BORDER BY LATE AFTERNOON. WITH LOW LEVEL SELYS OF ONLY 10-15KT AND LIFTED CONDENSATION LEVELS AROUND 2KM AGL...PRIMARY THREAT WOULD BE LARGE HAIL. ...OH VALLEY ACROSS SRN PLAINS... MUCH OF THIS REGION ALONG AND AHEAD OF COLD FRONT IS CHARACTERIZED BY WARM 500 MB TEMPERATURES AND GENERALLY WEAK LOW LEVEL SHEAR. WITH PW/S BETWEEN 1.5 AND 2 INCHES ALONG WITH STRONG SURFACE HEATING...MLCAPES OF 2000 J/KG WILL BE COMMON BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT BY THIS AFTERNOON HOWEVER SEVERE THREAT EXPECTED TO BE LIMITED TO LOCAL DAMAGING DOWNBURSTS FROM PRIMARILY PULSE AND MULTICELLULAR CONVECTION. STRONGER DEEP LAYER SHEAR UPWARDS TO 30KT WILL BE AVAILABLE ACROSS UPPER OH VALLEY...BUT THE WARM MID LEVELS SHOULD LIMIT UPDRAFT STRENGTH. THUS ONLY ISOLATED POTENTIAL FOR WIND DAMAGE IS EXPECTED. ...AZ... DRIER AIR IS GRADUALLY WORKING EWD AT MID LEVELS ACROSS CENTRAL AZ AS NOTED ON FLG AND PHX 12Z SOUNDINGS. LOW LEVELS REMAIN VERY MOIST...THUS THUNDERSTORMS WILL DEVELOP OVER HIGHER TERRAIN BY MID AFTERNOON. THE ENTRAINMENT OF THE DRIER MID LEVEL AIR DOES INCREASE POTENTIAL FOR DOWNBURSTS...THOUGH THE GENERALLY WEAK STEERING FLOW PRECLUDES A SLIGHT RISK. ..HALES/JEWELL.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 16:32:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 12:32:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141633 SWODY1 SPC AC 141631 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1131 AM CDT MON AUG 14 2006 VALID 141630Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF ERN WY/NEB PANHANDLE AND SWRN SD... CORRECTED FOR REVERSAL OF HAIL PROB LINE IN AZ ...SYNOPSIS... PROGRESSIVE TROUGH CONTINUES EWD ACROSS GREAT LAKES TO NERN U.S. THIS FORECAST PERIOD. COLD FRONT ACCOMPANYING TROUGH THIS AM LOCATED FROM LOWER MI SWWD THRU SWRN MO TO SCENTRAL OK THEN WWD TO CENTRAL NM. SURFACE HIGH CENTRAL NEB WILL SHIFT TO LOWER MO VALLEY BY 12Z TUE ALLOWING SELY UPSLOPE FLOW TO PERSIST THE LEE OF CENTRAL ROCKIES. ...ERN WY/NEB PANHANDLE/SWRN SD... CONSISTENT MODEL SIGNAL FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON IN THE CURRENT UPSLOPE REGIME LEE OF CENTRAL ROCKIES. WITH DEWPOINTS EXPECTED TO HOLD AT 50 F OR HIGHER E OF HIGHER TERRAIN AS FAR N AS ECENTRAL WY...AIR MASS EXPECTED TO BECOME SUFFICIENTLY UNSTABLE TO SUPPORT STRONG/SEVERE THUNDERSTORMS. WITH LAPSE RATES IN EXCESS OF 8C/KM AND VEERING SHEAR PROFILES UPWARDS TO 30KT...PARAMETERS SHOULD BE IN PLACE FOR AT LEAST ISOLATED SUPERCELL DEVELOPMENT VICINITY NEB/WY BORDER BY LATE AFTERNOON. WITH LOW LEVEL SELYS OF ONLY 10-15KT AND LIFTED CONDENSATION LEVELS AROUND 2KM AGL...PRIMARY THREAT WOULD BE LARGE HAIL. ...OH VALLEY ACROSS SRN PLAINS... MUCH OF THIS REGION ALONG AND AHEAD OF COLD FRONT IS CHARACTERIZED BY WARM 500 MB TEMPERATURES AND GENERALLY WEAK LOW LEVEL SHEAR. WITH PW/S BETWEEN 1.5 AND 2 INCHES ALONG WITH STRONG SURFACE HEATING...MLCAPES OF 2000 J/KG WILL BE COMMON BY MID AFTERNOON. THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT BY THIS AFTERNOON HOWEVER SEVERE THREAT EXPECTED TO BE LIMITED TO LOCAL DAMAGING DOWNBURSTS FROM PRIMARILY PULSE AND MULTICELLULAR CONVECTION. STRONGER DEEP LAYER SHEAR UPWARDS TO 30KT WILL BE AVAILABLE ACROSS UPPER OH VALLEY...BUT THE WARM MID LEVELS SHOULD LIMIT UPDRAFT STRENGTH. THUS ONLY ISOLATED POTENTIAL FOR WIND DAMAGE IS EXPECTED. ...AZ... DRIER AIR IS GRADUALLY WORKING EWD AT MID LEVELS ACROSS CENTRAL AZ AS NOTED ON FLG AND PHX 12Z SOUNDINGS. LOW LEVELS REMAIN VERY MOIST...THUS THUNDERSTORMS WILL DEVELOP OVER HIGHER TERRAIN BY MID AFTERNOON. THE ENTRAINMENT OF THE DRIER MID LEVEL AIR DOES INCREASE POTENTIAL FOR DOWNBURSTS...THOUGH THE GENERALLY WEAK STEERING FLOW PRECLUDES A SLIGHT RISK. ..HALES.. 08/14/2006  From swody1 at goshenarc.org Mon Aug 14 19:55:22 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 15:55:22 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 141955 SWODY1 SPC AC 141953 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0253 PM CDT MON AUG 14 2006 VALID 142000Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CO/WY/SWRN SD/WRN NEB... ...THERE IS A SLGT RISK OF SVR TSTMS LOWER OH VALLEY THROUGH OZARKS... ...SYNOPSIS... SYNOPTIC PATTERN WILL REMAIN CHARACTERIZED BY PROGRESSIVE NRN STREAM ACROSS NRN 1/2-1/3 OF CONUS. ELONGATED AREA OF RIDGING ALOFT -- INTERSPERSED WITH SEVERAL WEAK AND SLOW-MOVING SHORTWAVES -- WILL EXTEND FROM AZ ACROSS SRN PLAINS...EWD TO OFFSHORE GA/SC. STRONG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NRN ONT AND UPPER GREAT LAKES REGION...WILL CONTINUE TO MOVE EWD TOWARD ERN ONT AND QUE. ASSOCIATED SFC COLD FRONT IS ANALYZED FROM ERN LOWER MI SWWD ACROSS SWRN MO AND SRN TX PANHANDLE. FRONT HAS STALLED OVER SRN PLAINS AND SHOULD DECELERATE ACROSS OZARKS AREA...WHILE MOVING SEWD THROUGH MID/UPPER OH VALLEY REGION. ...CENTRAL HIGH PLAINS... VIS IMAGERY INDICATED CB DEVELOPING AND INCREASING IN COVERAGE OVER FRONT/LARAMIE RANGES. FARTHER E ACROSS HIGH PLAINS...AXIS OF RELATIVELY STEEP MIDLEVEL LAPSE RATES -- 8-8.5 DEG C/KM -- IS ANALYZED ACROSS THIS AREA. THIS CROSSES N-S ORIENTED BOUNDARY LAYER MOIST AXIS OVER SERN WY...WITH MOIST PLUME EXTENDING SSEWD ACROSS ERN CO. DEEP-LAYER VERTICAL SHEAR PROFILES INCREASE WITH NWD EXTENT...AND PROXIMITY TO MID/UPPER LEVEL NRN STREAM JET...AND SLY MOIST ADVECTION WILL COMBINE WITH DIABATIC HEATING TO INCREASE BUOYANCY NWD ACROSS SWRN ND AND ERN WY. THESE FACTORS WILL SUPPORT INTENSIFICATION OF CONVECTION OVER THIS REGION TO SVR LEVELS WITH LARGE HAIL AND OCCASIONAL DAMAGING GUSTS POSSIBLE. REF SPC WW 720 AND RELATED MESOSCALE DISCUSSIONS FOR NEAR-TERM DETAILS. ...OH VALLEY TO SRN PLAINS... WIDELY SCATTERED TO SCATTERED TSTMS ARE EXPECTED THROUGH REMAINDER AFTERNOON INTO EVENING HOURS...ALONG/AHEAD OF SFC COLD FRONT...FROM WRN UPSTATE NY TO SRN HIGH PLAINS. IN ADDITION TO FRONT...OUTFLOW BOUNDARIES WILL ACT AS FOCI FOR CONVECTIVE INITIATION. ISOLATED DAMAGING DOWNBURSTS ARE POSSIBLE FROM PULSE/MULTICELL CONVECTION ALMOST ANYWHERE WITHIN THAT SWATH. MOST PROBABLE AREA FOR RELATIVELY DENSE CONCENTRATION OF MULTICELLS...AND OF POTENTIAL FOR MULTIPLE STG-SVR TSTMS...APPEARS TO BE FROM NRN AR TOWARD SWRN INDIANA/WRN KY. PRE-STORM AIR MASS ACROSS THIS AREA WILL CONTINUE TO BE FAVORABLY UNSTABLE FOR SEVERAL MORE HOURS WITH 70S SFC DEW POINTS AND STG HEATING CONTRIBUTING TO MLCAPES IN 2500-3500 J/KG RANGE. SVR POTENTIAL IS STRONGLY TIED TO DIABATIC HEATING AND EXPECTED TO WEAKEN GRADUALLY AFTER SUNSET. ...SERN AZ/SWRN NM... WIDELY SCATTERED TSTMS SHOULD INCREASE IN COVERAGE THROUGH REMAINDER AFTERNOON. MOST FAVORABLE AREA FOR ISOLATED DAMAGING GUSTS AND HAIL NEAR SVR LEVELS IS IN CORRIDOR FROM NWRN TO SERN AZ WHERE ERN PORTION OF STRONGEST SFC WARMING WILL OVERLAP WRN EXTENT OF RICH LOW LEVEL MOISTURE PLUME. SFC DEW POINTS MID 70S F WILL SUPPORT MLCAPES 1500-2500 J/KG OVER MOST DESERT AREAS...THOUGH WITH WEAK AMBIENT FLOW...OROGRAPHICALLY INITIATED STORMS WILL BE SLOW TO MOVE OVER DEEPER BOUNDARY LAYERS OF DESERTS. HOWEVER...ADDITIONAL DEVELOPMENT MAY OCCUR ALONG OUTFLOW BOUNDARIES GENERATED BY EARLIEST CONVECTION. TSTMS SHOULD DIMINISH IN COVERAGE AND INTENSITY AFTER NIGHTFALL...BECAUSE OF COMBINED STABILIZING EFFECTS OF SPREADING OUTFLOW AIR AND SFC DIABATIC COOLING. ..EDWARDS.. 08/14/2006  From swody1 at goshenarc.org Tue Aug 15 00:55:54 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 14 Aug 2006 20:55:54 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150056 SWODY1 SPC AC 150054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0754 PM CDT MON AUG 14 2006 VALID 150100Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID MS VALLEY... ...HIGH PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH DRIFTING EWD INTO WRN SD ATTM. SCATTERED THUNDERSTORMS ARE ONGOING ALONG THE LEADING EDGE OF LARGE-SCALE ASCENT AND JUST AHEAD OF A WELL-DEFINED DRY SLOT. THE STORMS ARE FORMING ALONG THE WRN EDGE OF THE LOW-LEVEL MOIST AXIS IN A SMALL POCKET OF MODERATE INSTABILITY WHERE MLCAPE VALUES RANGE FROM 1000 TO 1500 J/KG. THE INSTABILITY IN PLACE SHOULD SUSTAIN STRONG UPDRAFTS THROUGH MUCH OF THE EVENING. THE 00Z SOUNDING AT RAPID CITY SHOWS A STRONG VEERING WIND PROFILE WHICH IS SUPPORTING SUPERCELLS ONGOING IN SW SD ATTM. THE CLUSTER OF SEVERE THUNDERSTORMS IS LOCATED ALONG THE ERN EDGE OF VERY STEEP MID-LEVEL LAPSE RATES. IN ADDITION...0-3 KM LAPSE RATES IN SWRN SD EXCEED 9.0 C/KM WHICH ALONG WITH THE SHEAR SUGGESTS THE THREAT FOR LARGE HAIL AND WIND DAMAGE WILL CONTINUE WITH THE STRONGER CELLS THIS EVENING. ...MID MS VALLEY/SRN PLAINS... LATEST WATER VAPOR IMAGERY SHOWS A LARGE UPPER-LEVEL TROUGH OVER ONTARIO EXTENDING SWD INTO THE OH VALLEY REGION. NUMEROUS THUNDERSTORMS ARE ONGOING ALONG THE SRN EDGE OF A PLUME OF MID-LEVEL MOISTURE EXTENDING ENEWD FROM NRN OK ACROSS MO INTO THE LOWER OH VALLEY. THE HIGHEST SFC DEWPOINTS AND STRONGEST INSTABILITY EXISTS ACROSS NE AR...SE MO...NW TN AND WRN KY WHERE MLCAPE VALUES RANGE FROM 2500 TO 3000 J/KG ACCORDING TO RUC ANALYSIS. THE 00Z NASHVILLE SOUNDING SHOWS ABOUT 25 KT OF VERTICAL SHEAR WHICH COMBINED WITH THE STRONG INSTABILITY SHOULD BE SUFFICIENT TO CONTINUE A THREAT FOR MULTICELLS CAPABLE OF ISOLATED WIND DAMAGE FOR A FEW MORE HOURS. THE THREAT SHOULD DECREASE THIS EVENING AS LOW-LEVEL LAPSE RATES CONTINUE TO WEAKEN. ...SRN AND CNTRL AZ... A BROKEN LINE OF STRONG THUNDERSTORMS IS CURRENTLY ONGOING IN CNTRL AZ. THE STORMS ARE LOCATED ALONG AND JUST TO THE SOUTHWEST OF A MOIST AXIS WHERE DEWPOINTS RANGE FROM 55 TO 65 F. MUCAPE VALUES ABOVE 1500 J/KG AS SHOWN ON REGIONAL SOUNDINGS LARGE TEMP-DEWPOINT SPREADS MAY BE FAVORABLE FOR A FEW THUNDERSTORMS CAPABLE OF MARGINALLY SEVERE WIND DAMAGE EARLY THIS EVENING. ..BROYLES.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 05:53:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 01:53:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 150553 SWODY1 SPC AC 150552 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1252 AM CDT TUE AUG 15 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...NRN PLAINS... AN UPPER-LEVEL TROUGH OVER THE PACIFIC NORTHWEST IS FORECAST TO DEEPEN TODAY AS A LEAD SHORTWAVE TROUGH MOVES INTO THE NRN ROCKIES THIS AFTERNOON. THUNDERSTORMS SHOULD INITIATE IN THE HIGHER TERRAIN OF ID AND MT IN THE AFTERNOON WITH ADDITIONAL CONVECTION DEVELOPING IN THE NRN HIGH PLAINS AS THE TROUGH COMES OUT OF THE ROCKIES THIS EVENING. FORECAST SOUNDINGS ACROSS ERN MT AND WRN ND THIS EVENING SHOW MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES. THIS SHOULD BE ENOUGH FOR A FEW SEVERE STORMS IF THUNDERSTORM INITIATION OCCURS IN AREAS WITH THE STRONGER INSTABILITY. HOWEVER...UNCERTAINTY CONCERNING TIMING AND DESTABILIZATION STILL REMAINS. ONCE CERTAINTY INCREASES IN THE SCENARIO...AN UPGRADE TO SLIGHT RISK MAY BECOME NECESSARY IN LATER OUTLOOKS. ...TN VALLEY/LOWER MS VALLEY... SCATTERED TO NUMEROUS THUNDERSTORMS WILL AGAIN INITIATE THIS AFTERNOON ALONG AND BEHIND A COLD FRONT POSITIONED FROM SRN MS EXTENDING NEWD ACROSS AL AND GA. FORECAST SOUNDINGS THIS AFTERNOON ACROSS THE REGION SHOW MODERATE INSTABILITY WITH RELATIVELY WEAK SHEAR PROFILES. ALTHOUGH A FEW MARGINALLY SEVERE THUNDERSTORMS SHOULD DEVELOP...THE WEAK SHEAR SHOULD KEEP ANY THREAT ISOLATED. STRONG GUSTY WINDS WILL BE POSSIBLE WITH THE STRONGER THUNDERSTORMS NEAR AREAS OF LOCALLY STEEP LOW-LEVEL LAPSE RATES. ..BROYLES/TAYLOR.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 12:53:35 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 08:53:35 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151222 SWODY1 SPC AC 151220 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0720 AM CDT TUE AUG 15 2006 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...LOWER MS VALLEY/TN VALLEY/CAROLINAS... LARGE UPPER TROUGH IS MOVING ACROSS EASTERN CANADA THIS MORNING...WITH BROAD UPPER RIDGE MAINTAINING CONTROL ACROSS THE SOUTHERN STATES. WEAK SURFACE BAROCLINIC ZONE EXTENDS FROM MID ATLANTIC REGION INTO OK/AR. THIS ZONE WILL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS. AIR MASS ALONG AND SOUTH OF BOUNDARY WILL BE HOT TODAY WITH TEMPERATURES IN THE 90S...ALONG WITH DEWPOINTS NEAR 70F. DESPITE HIGH THETA-E VALUES AT THE SURFACE...WARM TEMPERATURES ALOFT WILL LIMIT LAPSE RATES AND AVAILABLE CAPE. ALSO...BOUNDARY HAS SAGGED SOUTH OF STRONGER WESTERLIES ALOFT...WITH ONLY WEAK VERTICAL SHEAR PROFILES SHOWN ON FORECAST SOUNDINGS. ISOLATED CELLS ALONG THIS AXIS WILL BE CAPABLE OF LOCALLY GUSTY WINDS. HOWEVER...ORGANIZED SEVERE THUNDERSTORM ACTIVITY DOES NOT APPEAR LIKELY. ...NORTHERN HIGH PLAINS... SERIES OF WEAK UPPER FEATURES ARE NOTED ON MORNING WATER VAPOR IMAGERY OVER THE NORTHERN GREAT BASIN AND NORTHERN ROCKIES. THESE FEATURES HAVE RESULTED IN SCATTERED THUNDERSTORMS OVER PARTS OF ID/UT/WY OVERNIGHT. STEEP MID LEVEL LAPSE RATES AND FAST SOUTHWESTERLY FLOW ALOFT WILL PROMOTE A CONTINUED RISK OF GUSTY/DAMAGING WINDS IN CONVECTION THROUGH THE DAY AS IT SPREADS EASTWARD TOWARD THE WESTERN DAKOTAS. POTENTIAL EXISTS FOR RE-DEVELOPMENT OF SCATTERED THUNDERSTORMS THIS AFTERNOON OVER PARTS OF EASTERN ID/NORTHWEST WY...WITH A RENEWED THREAT OF DAMAGING WINDS. FINALLY...ISOLATED THUNDERSTORMS MAY INTENSIFY EARLY THIS EVENING OVER PARTS OF ND/SD AS SOUTHERLY LOW LEVEL JET INTENSIFIES AND ENHANCES WARM ADVECTION. FORECAST SOUNDINGS SUGGEST A THREAT OF HIGH-BASED SUPERCELLS IN THIS REGION...WITH A RISK OF HAIL AND GUSTY WINDS. ..HART/TAYLOR.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 16:18:32 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 12:18:32 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 151617 SWODY1 SPC AC 151615 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 AM CDT TUE AUG 15 2006 VALID 151630Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... PRIMARY WESTERLIES REMAIN ACROSS NRN TIER OF CONUS WITH PROGRESSIVE LARGE SCALE FEATURES. TROUGH MOVING EWD THRU NERN STATES WHILE SOME AMPLIFICATION OCCURS UPSTREAM WITH TROUGH ENTERING PAC NW. BROAD RIDGE SHIFTS EWD ACROSS NRN PLAINS/UPPER MS VALLEY THIS FORECAST PERIOD. S/WV IMPULSE RIDING ACROSS RIDGE LOCATED WY/SRN MT WILL CROSS NRN PLAINS TONIGHT. COLD FRONT WILL MOVE OFF NERN COAST THIS AFTERNOON TRAILING WSWWD THRU DELMARVA TO TN/MID MS VALLEY. WWD ACROSS SRN PLAINS FRONT WILL BEGIN LIFTING NWD AS LEE TROUGH DEVELOPS E OF ROCKIES. ...NRN HIGH PLAINS... RATHER ACTIVE OVERNIGHT HIGH BASED CONVECTION NOTED WITH S/WV NOW CROSSING WY/SRN MT. THIS FEATURE WILL PROVIDE SOME DYNAMIC SUPPORT ALONG WITH ENHANCED DEEP LAYER SHEAR FOR POTENTIAL OF STRONG/SEVERE THUNDERSTORMS THIS AFTERNOON. WITH STEEP LAPSE RATES IN PLACE AND LOW LEVEL MOISTURE SPREADING NWD THRU HIGH PLAINS E OF LEE TROUGH...EXPECT AT LEAST ISOLATED SEVERE STORMS TO DEVELOP BY MID AFTERNOON WITH PRIMARY THREAT LARGE HAIL AND DOWNBURST WINDS. WHILE SHEAR OF 35-40KT SUGGESTS AN UPGRADE COULD BE NEEDED...THERE IS SUFFICIENT DOUBT AS TO AVAILABLE MOISTURE/INSTABILITY TO SUPPORT THE STORM COVERAGE NEED FOR A SLIGHT RISK ATTM. PORTION OF HIGH PLAINS COULD BE UPGRADED IN AFTERNOON UPDATE. FARTHER W STEEP LAPSE RATES AND STRONG HEATING WILL SUPPORT REDEVELOPMENT OF HIGH BASED STORMS FROM SERN ID ACROSS NRN WY/SRN MT. PRIMARY THREAT WOULD BE ISOLATED STRONG WINDS. ...MID ATLANTIC STATES WWD TO LOWER MS VALLEY... AIR MASS S OF FRONTAL ZONE REMAINS MOIST AND POTENTIALLY VERY UNSTABLE. WHILE WEAK SHEAR PROFILES SUPPORT PRIMARILY PULSE STORMS...MLCAPES UPWARDS TO 2000 J/KG AND STEEP LOW LEVEL LAPSE RATES SUPPORT WET DOWNBURSTS. SEVERE THREAT WILL BE HIGHLY DIURNAL DIMINISHING BY SUNSET. ..HALES/GUYER.. 08/15/2006  From swody1 at goshenarc.org Tue Aug 15 20:04:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 16:04:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 152003 SWODY1 SPC AC 152002 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0302 PM CDT TUE AUG 15 2006 VALID 152000Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS EXTREME ERN WY...NWRN NEB...SD...SERN ND...WRN MN... ...SYNOPSIS... IN MIDDLE-UPPER LEVELS...PROGRESSIVE NRN STREAM PATTERN WILL BE DOMINATED BY WEAKENING TROUGH OVER QUE/NERN CONUS...AND AMPLIFYING TROUGH MOVING SEWD INTO PACIFIC NW STATES. MEAN RIDGE WILL CONTINUE SHIFTING EWD ACROSS NRN PLAINS TOWARD UPPER MS VALLEY. WEAK SRN STREAM PERTURBATIONS NOW OVER W TX AND NM ARE EXPECTED TO LIFT NEWD ACROSS SRN ROCKIES AND SRN PLAINS THROUGH REMAINDER PERIOD. AT SFC...COLD FRONT IS EVIDENT FROM DELMARVA PENINSULA SWWD THROUGH SRN APPALACHIANS...BECOMING QUASISTATIONARY WWD ACROSS AR...THEN WARM FRONT ACROSS OK. LEESIDE CYCLOGENESIS IS EVIDENT ACROSS NRN HIGH PLAINS...WITH SEVERAL WEAK LOW PRESSURE CENTERS FROM SRN SASK SEWD ACROSS SD. FRONTOGENESIS ACROSS SRN SASK AND NRN MT SHOULD RESULT IN COLD FRONT MOVING SEWD OVER ERN MT AND INTO NWRN ND BY 16/12Z. ...NRN PLAINS... INITIALLY ELEVATED DEVELOPMENT EVIDENT ATTM OVER NERN SD MAY CONTINUE AND MOVE EWD ACROSS PORTIONS CENTRAL/NRN MN THROUGH REMAINDER EVENING. ALTHOUGH MOISTURE WILL REMAIN MRGL WITH SFC DEW POINTS MID 50S TO AROUND 60 F...STG SFC HEATING IN MODIFIED FCST SOUNDINGS RENDERS SFC-BASED PARCELS AND INVERTED-V SHAPE TO BOUNDARY LAYER THERMODYNAMIC PROFILE. VERTICAL SHEAR PROFILES IN RUC FCST SOUNDINGS SHOW CONSIDERABLE VEERING WITH HEIGHT AND SUGGEST SOME SUPERCELL POTENTIAL...WITH ORGANIZED MULTICELL CONVECTION ALSO POSSIBLE. THEREFORE POTENTIALLY DAMAGING GUSTS AND LARGE HAIL MAY OCCUR WITH SOME OF THIS ACTIVITY...AS WELL AS WITH SFC-BASED CONVECTION DEVELOPING FARTHER W ACROSS ERN WY AND SWRN SD. LATTER ACTIVITY IS OCCURRING IN SOMEWHAT WEAKER SHEAR ENVIRONMENT BUT WILL MOVE ALONG OR PARALLEL TO SFC MOIST AXIS -- ANALYZED ATTM FROM SERN WY NEWD ACROSS BADLANDS OF SD...TO NERN CORNER SD AND INTO SWRN MN. SVR POTENTIAL MAY PERSIST AFTER DARK INVOF NOSE OF STRENGTHENING LLJ...WHICH WILL ADVECT INCREASINGLY RICH MOISTURE NWD FROM SRN PLAINS AND CENTRAL HIGH PLAINS IN A NARROW PLUME. ...SERN CONUS...SRN PLAINS... SCATTERED TSTMS IN MULTICELL CLUSTERS ALREADY HAVE DEVELOPED IN BKN BAND FROM CENTRAL VA SWWD TO ERN MS. THIS ACTIVITY SHOULD SHIFT/EXPAND SWD AND SWWD THROUGH REMAINDER AFTERNOON...AS CONVECTIVE OUTFLOWS PROPAGATE INITIATION POTENTIAL DEEPER INTO MARITIME/TROPICAL AIR MASS THAT CHARACTERIZES MUCH OF SERN CONUS. DEVELOPMENT ALSO IS EXPECTED ALONG AND S OF FRONT WWD ACROSS AR INTO CENTRAL/ERN OK...WHERE STRONGEST HEATING IS OCCURRING. SFC DEW POINTS MID 60S/MID 70S F AND INSOLATION WILL SUPPORT MLCAPES 2500-4000 J/KG FROM NWRN GA INTO SERN OK...AMIDST WEAKENING CINH. WEAK DEEP-LAYER KINEMATIC PROFILES ARE EXPECTED TO LIMIT OVERALL ORGANIZATION OF CONVECTION IN THIS CORRIDOR. PULSE AND MULTICELL MODES ARE EXPECTED WITH SVR POTENTIAL BEING BRIEF AND ISOLATED...THEREFORE PROBABILITIES REMAIN TOO LOW TO WARRANT CATEGORICAL OUTLOOK ATTM. ..EDWARDS.. 08/15/2006  From swody1 at goshenarc.org Wed Aug 16 00:56:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 15 Aug 2006 20:56:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160057 SWODY1 SPC AC 160055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 PM CDT TUE AUG 15 2006 VALID 160100Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SD...SERN ND AND WRN MN... ...SYNOPSIS... PROGRESSIVE NRN STREAM PATTERN WILL CONTINUE ALOFT...WITH TROUGH WEAKENING/EJECTING ACROSS QUE AND NEW ENGLAND...MEAN RIDGE SHIFTING EWD OVER NRN PLAINS/UPPER MS VALLEY REGION...AND NERN PACIFIC TROUGH DIGGING ESEWD INTO PACIFIC NW. AT SFC...COLD FRONT IS ANALYZED FROM SRN DELMARVA PENINSULA SWWD THROUGH SRN APPALACHIANS...BECOMING QUASISTATIONARY WWD ACROSS AR...THEN DIFFUSE AND CONVECTIVELY MODULATED WARM FRONT OVER PORTIONS NRN OK/SRN KS. LEESIDE CYCLOGENESIS CONTINUES OVER NRN HIGH PLAINS...WHERE SEVERAL WEAK LOW PRESSURE CENTERS EVIDENT EARLIER THIS AFTERNOON HAVE CONSOLIDATED INTO TWO MAIN LOWS...INVOF NERN AND SERN CORNERS OF MT. WARM FRONT IS BECOMING BETTER DEFINED ACROSS NRN SD...AND SHOULD LIFT NWD INTO SRN ND AND ACROSS WRN MN OVERNIGHT. ...NRN PLAINS TO UPPER MS VALLEY... PRIMARY UNCONDITIONAL SEVERE THREAT WILL OCCUR THROUGH APPROXIMATELY 05Z...ASSOCIATED WITH POTENTIAL FOR ADDITIONAL DEVELOPMENT WITHIN...OR UPSCALE EVOLUTION OF...TWO PRIMARY NODES OF DIURNAL CONVECTIVE DEVELOPMENT -- OVER NERN SD/WRN MN AND OVER SWRN ND. REF SPC WW 722 AND RELATED MESOSCALE DISCUSSIONS FOR SHORT-TERM FCST DETAILS. SOME POTENTIAL EXISTS FOR MCS TO EVOLVE OVERNIGHT INVOF NOSE OF INCREASINGLY MOIST LLJ OVER SD...IN ZONE OF STRONGEST LOW LEVEL WAA AND MOIST ADVECTION ABOVE SFC. HOWEVER AVAILABLE RAOB DATA AND RUC PROGS INDICATE OPTIMAL 850 MB DEW POINTS MAY NOT REACH THIS AREA UNTIL AFTER 06Z. THIS CASTS DOUBT ON PERSISTENCE OF CURRENT OUTFLOW-DOMINANT CONVECTION ONCE BOUNDARY LAYER MORE STRONGLY COOLS/DECOUPLES AND REDUCES SBCAPE. ...SERN CONUS... PRIMARY AREA OF CONCERN FOR STG...POTENTIALLY DAMAGING GUSTS THROUGH REMAINDER EVENING WILL BE AREA ALONG AND S OF ONGOING CLUSTER OF ORGANIZED MULTICELLS...NOW MOVING SWD ACROSS AL AND SRN MS. AIR MASS BETWEEN THIS ACTIVITY AND GULF COAST WILL REMAIN FAVORABLY MOIST AND UNSTABLE WITH SFC DEW POINTS 70S F...AND MLCAPES 1500-2000 J/KG PER MODIFIED TLH RAOBS AND RUC SOUNDINGS. SOME POTENTIAL FOR GUSTS NEAR SVR LEVELS MAY PERSIST ANOTHER 1-2 HOURS ELSEWHERE ALONG AND S OF FRONTAL ZONE...FROM OK TO ATLANTIC COAST...HOWEVER THIS POTENTIAL IS BECOMING TOO BRIEF/ISOLATED TO WARRANT SVR PROBABILITIES. ..EDWARDS.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 06:00:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 02:00:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 160559 SWODY1 SPC AC 160558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT WED AUG 16 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL PLAINS... ...CNTRL PLAINS... AN UPPER-LEVEL RIDGE OVER THE MO VALLEY WILL SHIFT EWD TODAY AS A SHORTWAVE TROUGH MOVES NEWD OUT OF THE CNTRL ROCKIES. A WEAK FRONTAL BOUNDARY OVER THE SRN PLAINS WILL MOVE NWD EXTENDING FROM NCNTRL KS INTO SW NEB. CONVERGENCE ALONG THE BOUNDARY COMBINED WITH LARGE-SCALE ASCENT ASSOCIATED WITH THE SHORTWAVE TROUGH SHOULD PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THUNDERSTORMS APPEAR LIKELY TO INITIATE NEAR THE BOUNDARY IN CNTRL AND NRN KS WITH CONVECTION EXPANDING NEWD ACROSS CNTRL AND ERN NEB. ADDITIONAL THUNDERSTORM DEVELOPMENT APPEARS LIKELY ALONG A SFC TROUGH EXISTING IN NE CO AND WRN NEB. FORECAST SOUNDINGS ACROSS SRN AND CNTRL NEB THIS AFTERNOON SHOW SUBSTANTIAL VEERING BELOW 700 MB WITH 0-6 KM SHEAR VALUES IN THE 25 TO 30 KT RANGE. THIS SHOULD BE FAVORABLE FOR ISOLATED SUPERCELLS IN AREAS WITH THE STRONGEST INSTABILITY. HOWEVER...MOST OF THE CONVECTION SHOULD REMAIN MULTICELL AS AN MCS ORGANIZES AND MOVES INTO ERN NEB AND POSSIBLY WRN IA BY EVENING. THE CURRENT THINKING IS THAT THE GREATEST SEVERE THREAT WILL BE THE MID-AFTERNOON BEFORE THE CONVECTION BECOMES ELEVATED NORTHEAST OF THE BOUNDARY. ALTHOUGH HAIL WILL BE POSSIBLE WITH THE STRONGER CELLS...THE MOST PROBABLE SEVERE THREAT WILL BE WIND DAMAGE JUST AFTER INITIATION NEAR THE BOUNDARY WHERE LOW-LEVEL LAPSE RATES ARE FORECAST TO BE THE STEEPEST. FURTHER NORTHWEST ACROSS WRN NEB...ISOLATED TO SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG A NORTH TO SOUTH SFC TROUGH WITH THE CONVECTION MOVING EWD INTO WRN NEB DURING THE LATE AFTERNOON. FORECAST SOUNDINGS IN WRN NEB THIS AFTERNOON SHOW STRONG ENOUGH VERTICAL SHEAR FOR SEVERE MULTICELLS. THE CONVECTION SHOULD BE THE STRONGEST IN THE LATE AFTERNOON AND EARLY EVENING AS LOW-LEVEL FLOW STRENGTHENS ACROSS THE REGION. STEEP LAPSE RATES AND COOLER MID-LEVEL TEMPS WILL LIKELY FAVOR EITHER A THREAT FOR HAIL AND/OR ISOLATED WIND DAMAGE WITH THE MORE ORGANIZED STORMS. ...NRN PLAINS... AN UPPER-LEVEL RIDGE OVER THE PLAINS STATES WILL MOVE INTO THE GREAT LAKES REGION TODAY AS A SHORTWAVE TROUGH DRIFTS ENEWD INTO THE NRN PLAINS. A COLD FRONT WILL ADVANCE SEWD ACROSS ND AND THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE BOUNDARY DURING THE AFTERNOON. FORECAST SOUNDINGS IN ERN ND THIS AFTERNOON SHOW MODERATE INSTABILITY AND STRONG ENOUGH SHEAR PROFILES FOR ORGANIZED MULTICELLS. HOWEVER...THE NUMBER OF STORMS THAT WILL INITIATE REMAINS UNCERTAIN WHICH COULD LIMIT THE SEVERE WEATHER THREAT AREA. IF A SHORTWAVE CURRENTLY OVER THE NRN ROCKIES TIMES WELL WITH MAXIMUM INSTABILITY ACROSS ERN ND...A SLIGHT RISK UPGRADE MAY BECOME NECESSARY IN LATER OUTLOOKS. ...NRN ROCKIES... A WELL-DEVELOPED UPPER-LEVEL TROUGH OFF THE COAST OF THE PACIFIC NORTHWEST WILL MOVE INLAND TODAY. THIS WILL SPREAD STRONG LARGE-SCALE ASCENT EWD INTO ID AND WRN MT WITH SCATTERED THUNDERSTORM INITIATION LIKELY IN THE HIGHER TERRAIN THIS AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON IN THE NRN ROCKIES SHOW STRONG ENOUGH SHEAR PROFILES FOR SEVERE STORMS. IF ENOUGH INSTABILITY CAN DEVELOP IN AREAS WHERE CONVECTION FORMS...HAIL AND STRONG WIND GUSTS WOULD BE POSSIBLE. A SLIGHT RISK AREA MAY BECOME NECESSARY IF POCKETS OF MODERATE INSTABILITY DEVELOP THIS AFTERNOON ACROSS THE REGION. ..BROYLES/BOTHWELL.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 12:46:23 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 08:46:23 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161246 SWODY1 SPC AC 161244 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0744 AM CDT WED AUG 16 2006 VALID 161300Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF EASTERN ND AND NORTHWEST MN... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF NEB/KS... LARGE UPPER RIDGE REMAINS FROM THE SOUTHERN PLAINS INTO THE OH VALLEY TODAY...WITH SERIES OF SHORTWAVE TROUGHS MOVING FROM THE NRN CALIFORNIA COAST...ACROSS THE CENTRAL/NORTHERN ROCKIES...INTO THE GREAT LAKES REGION. THE OVERALL THREAT OF SEVERE STORMS ACROSS THE NATION IS EXPECTED TO BE RATHER LOW TODAY. HOWEVER...THERE ARE A FEW LOCALIZED AREAS WHERE GREATER THREATS OF HAIL/DAMAGING WINDS WILL EXIST. ...ND/MN... WATER VAPOR IMAGERY SHOWS RELATIVELY FAST-MOVING SHORTWAVE TROUGH NOW OVER EASTERN MT. THIS FEATURE WILL MOVE EASTWARD ACROSS ND TODAY...WITH ACCOMPANYING COLD FRONT EXTENDING FROM EXTREME NORTHWEST MN INTO CENTRAL SD BY 00Z. THE LOW LEVEL AIR MASS AHEAD OF THE COLD FRONT IS EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS CLIMBING INTO THE 60S AND POCKETS OF HEATING. MODELS ARE IN GENERAL AGREEMENT THAT SCATTERED THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE FRONT OVER EASTERN ND AND SPREAD INTO MN THIS EVENING. VERTICAL SHEAR PROFILES IN THIS REGION WILL BE FAVORABLE FOR SUPERCELLS CAPABLE OF HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY WEAKEN RAPIDLY AS IT MOVES INTO MN DUE TO MORE STABLE AIRMASS. ...NEB/KS... SURFACE WARM FRONT IS SLOWLY RETREATING NORTHWARD ACROSS KS THIS MORNING. THE AIRMASS SOUTH OF FRONT WILL LIKELY BECOME VERY UNSTABLE THIS AFTERNOON WITH TEMPERATURES NEAR 90F AND DEWPOINTS IN THE UPPER 60S. FORECAST SOUNDINGS IN THIS REGION SHOW A DEEP-MIXED BOUNDARY LAYER AND MLCAPE VALUES OF 1000-1500 J/KG. AMPLE MID LEVEL MOISTURE OVER THIS AREA AND CONVERGENCE ALONG WEAK FRONT WILL PROMOTE SCATTERED THUNDERSTORMS THIS AFTERNOON...WITH DAMAGING WINDS POSSIBLE IN STRONGER CELLS. ACTIVITY SHOULD DIMINISH QUICKLY AFTER SUNSET. ...MT/ID... VIGOROUS SHORTWAVE TROUGH IS CURRENTLY MOVING INLAND OVER NORTHERN CA. THIS FEATURE WILL TRACK EAST-NORTHEASTWARD AND AFFECT PORTIONS OF ID/MT THIS AFTERNOON. FORCING FOR LARGE SCALE UPWARD VERTICAL MOTION...ALONG WITH MARGINAL INSTABILITY AND DAYTIME HEATING...WILL HELP INITIATE THUNDERSTORMS OVER THE MOUNTAINS OF CENTRAL ID/WESTERN MT BY EARLY AFTERNOON. STRENGTH OF MID LEVEL WINDS AND INVERTED-V PROFILES WILL ENHANCE THE RISK OF GUSTY/DAMAGING WINDS IN STRONGER CELLS. ...GULF COAST... WEAK UPPER LOW IS MOVING NORTHWESTWARD ACROSS FL THIS MORNING. BAND OF MID LEVEL MOISTURE IS EVIDENT IN WATER VAPOR IMAGERY FROM NORTHERN GA/AL TO THE CENTRAL GULF COAST. THIS REGION WILL LIKELY BECOME MODERATELY UNSTABLE THIS AFTERNOON AS TEMPERATURES WARM WELL INTO THE 90S. SCATTERED THUNDERSTORMS ARE EXPECTED FROM SOUTHEAST LA INTO SOUTHWEST GA AND THE FL PANHANDLE. WET MICROBURSTS WILL BE POSSIBLE WITH MORE INTENSE CELLS. ..HART/LEVIT.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 16:03:39 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 12:03:39 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 161601 SWODY1 SPC AC 161600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 AM CDT WED AUG 16 2006 VALID 161630Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF NRN/CENTRAL ID AND WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ERN ND AND NWRN MN... ...WRN MT AND NRN/CENTRAL ID... TROUGH THAT DEEPENED SEWD INTO PAC NW PAST 24 HOURS IS NOW SHIFTING EWD SPREADING STRONGER FLOW...LARGE SCALE UPWARD MOTION FIELD AND COOLING ALOFT ACROSS NRN ROCKIES TODAY/TONIGHT. SURFACE HIGH DROPPING SEWD SRN PRAIRIE PROVINCES WILL PROVIDE UPSLOPE COMPONENT TO THE LOW LEVEL FLOW ENHANCING THE DEEP LAYER SHEAR PROFILES ACROSS WRN MT. ALTHOUGH THE AVAILABLE MOISTURE AND INSTABILITY WILL BE SOMEWHAT LIMITED AHEAD OF THE TROUGH...COMBINATION OF 40-50 KT OF SHEAR AND STEEP LAPSE RATES SUFFICIENT TO UPGRADE MUCH OF NRN ROCKIES TO A SLIGHT RISK FOR THIS AFTERNOON AND EVENING. WITH OVERNIGHT CONVECTION AND CLOUD COVER CURRENTLY CLEARING OUT OF THE NRN ROCKIES...FULL HEATING WILL RAPIDLY STEEPEN LOW LEVEL LAPSE RATES DURING AFTERNOON WITH THUNDERSTORMS FORMING OVER HIGHER TERRAIN FROM NERN ORE MTNS ACROSS CENTRAL ID INTO WRN MT. THE THREAT OF LARGE HAIL AND DAMAGING DOWNBURSTS WINDS WILL INCREASE BY MID/LATE AFTERNOON WITH MLCAPES UPWARDS TO 1000 J/KG DEVELOPING GIVEN THE STRONG SURFACE HEATING AND COLD ADVECTION ALOFT. ...ND/MN... WATER VAPOR IMAGERY SHOWS RELATIVELY FAST-MOVING SHORTWAVE TROUGH MOVING INTO WRN DAKOTAS. THIS FEATURE WILL MOVE EASTWARD ACROSS ND TODAY...WITH ACCOMPANYING COLD FRONT EXTENDING FROM ERN ND TO SWRN SD BY 00Z. THE LOW LEVEL AIR MASS AHEAD OF THE COLD FRONT IS EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH DEWPOINTS CLIMBING INTO THE 60S AND POCKETS OF HEATING. SCATTERED THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE FRONT OVER EASTERN ND AND SPREAD INTO MN THIS EVENING. VERTICAL SHEAR PROFILES IN THIS REGION WILL BE FAVORABLE FOR SUPERCELLS CAPABLE OF HAIL AND DAMAGING WINDS. ACTIVITY WILL LIKELY WEAKEN RAPIDLY OVERNIGHT AS STORMS MOVE INTO MN DUE TO MORE STABLE AIRMASS. ...KS/NE/SD... SLY FLOW RETURNING A MOIST AND POTENTIALLY MODERATELY UNSTABLE AIR MASS NWD THRU THE PLAINS. STRONG HEATING WILL STEEPEN LOW LEVEL LAPSE RATES ACROSS PLAINS THIS AFTERNOON. WITH MLCAPES UPWARDS TO 2000 J/KG...WET MICRO BURSTS ARE POSSIBLE MOST ANYWHERE IN THIS AREA WHERE STRONG STORMS DEVELOP. GENERALLY DEEP LAYER SHEAR LESS THAN 15KTS MUCH OF PLAINS SUPPORT A PULSE MODE FOR CONVECTIVE DEVELOPMENT. ..HALES/GUYER.. 08/16/2006  From swody1 at goshenarc.org Wed Aug 16 20:05:08 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 16:05:08 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 162005 SWODY1 SPC AC 162003 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT WED AUG 16 2006 VALID 162000Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN OR TO WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/ERN DAKOTAS...NWRN MN... ...SYNOPSIS... PROGRESSIVE NRN STREAM PATTERN CONTINUES...WITH HEIGHT FALLS CONCENTRATED ACROSS NRN ROCKIES ATTM. STRONG MIDDLE-UPPER LEVEL TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER CASCADES -- IS FCST TO MAINTAIN POSITIVE TILT WHILE DRIFTING EWD ACROSS CENTRAL/ERN PORTIONS WA/ORE AND NRN CA. FARTHER DOWNSTREAM...WEAK SHORTWAVE TROUGH EMBEDDED IN SW FLOW ALOFT WILL CONTINUE TO MOVE ENEWD ACROSS ND AND NWRN CORNER OF MN. AT SFC...LOW EVIDENT OVER EXTREME N-CENTRAL ND/SWRN MB ATTM SHOULD WEAKEN AS ASSOCIATED TROUGH MOVES PAST...AND AS ACCOMPANYING COLD FRONT MOVES SEWD OVER ND AND NWRN MN. TRAILING PORTION OF THIS FRONT WILL CONTINUE MOVING SWD OVER CENTRAL/ERN MT...BECOMING QUASISTATIONARY INVOF WY BORDER BY END OF PERIOD AS PRESSURES CONTINUE TO FALL IN WRN WY/SWRN ID. SECOND LOW IS ANALYZED OVER MO RIVER NEAR SD/ND BORDER...WITH WEAK COLD FRONT SWWD INTO SRN BLACK HILLS AND WARM FRONT ENEWD ACROSS SERN ND AND NRN MN. BAROCLINIC ZONES SHOULD MERGE BY LATE TONIGHT AND BECOME NEARLY STATIONARY FROM N-CENTRAL SD TO NRN MN. ...INTERIOR NWRN CONUS...NRN ROCKIES... AIR MASS CONTINUES TO DESTABILIZE ATTM BOTH SFC AND ALOFT. SFC DIABATIC HEATING AND DPVA IN MIDLEVELS ARE RESULTING IN STEEP UNSTABLE DEEP-LAYER LAPSE RATES AMIDST FAVORABLE VERTICAL SHEAR PROFILES...AHEAD OF MID/UPPER LEVEL TROUGH. COVERAGE AND INTENSITY OF TSTMS WILL CONTINUE TO GROW FOR A FEW MORE HOURS AS ACTIVITY INITIALLY OVER ERN ORE AND CENTRAL ID SHIFTS NEWD...WITH ADDITIONAL DEVELOPMENT POSSIBLE SWRN THROUGH W-CENTRAL MT. REF SPC WW 723 AND RELATED MESOSCALE DISCUSSIONS FOR SHORT-TERM DETAILS. SVR POTENTIAL SHOULD DIMINISH AFTER DARK FROM COMBINATION OF DIABATIC SFC COOLING AND INCREASING COVERAGE OF OUTFLOW AIR. ...NRN PLAINS... TSTMS ARE FCST TO DEVELOP AND BECOME SVR OVER PORTIONS CENTRAL/ERN DAKOTAS DURING NEXT SEVERAL HOURS...AS CAP WEAKENS AMIDST STRONG HEATING AND FAVORABLE SFC MOIST AXIS...AHEAD OF SFC FRONT. ADDITIONAL DESTABILIZATION ALOFT MAY BE PROVIDED BY WEAK DPVA/ASCENT ASSOCIATED WITH EJECTING ND SHORTWAVE. DAMAGING GUSTS AND HAIL ARE POSSIBLE. REF SPC MESOSCALE DISCUSSION 1822 FOR NOWCAST INFORMATION. AFTERNOON ACTIVITY MAY PERSIST THROUGH MUCH OF THIS EVENING IN NE-SW ORIENTED BAND MOVING SLOWLY EWD ACROSS ERN DAKOTAS AND PERHAPS NWRN MN. OVERALL SVR THREAT SHOULD DIMINISH GRADUALLY LATE THIS EVENING AND INTO OVERNIGHT HOURS. ..EDWARDS.. 08/16/2006  From swody1 at goshenarc.org Thu Aug 17 01:01:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 16 Aug 2006 21:01:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170100 SWODY1 SPC AC 170059 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0759 PM CDT WED AUG 16 2006 VALID 170100Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS CENTRAL ID AND WESTERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS FAR EASTERN DAKOTAS/NORTHWEST MN... ....ID/MT... WATER VAPOR IMAGERY EARLY THIS EVENING FEATURES POTENT UPPER TROUGH SHIFTING EASTWARD ACROSS ORE/WA. LARGE SCALE ASCENT ASSOCIATED WITH THE FEATURE HAS RESULTED IN A BROAD COVERAGE OF STRONG/OCCASIONALLY SEVERE STORMS ACROSS ID/WESTERN MT SINCE THIS AFTERNOON. WITHIN A STRONGLY SHEARED ENVIRONMENT...BOUNDARY LAYER STABILIZATION VIA CONVECTIVE OUTFLOWS/LOSS OF DAYTIME HEATING WILL TEND TO CURB CONVECTIVE INTENSITY REMAINDER OF THE EVENING IN AN ALREADY WEAKLY UNSTABLE AIRMASS /REFERENCE 00Z GREAT FALLS AND GLASGOW MT RAOBS/. NEVERTHELESS...ISOLATED LARGE HAIL AND STRONG WIND GUSTS WILL REMAIN POSSIBLE TONIGHT AS THUNDERSTORM CLUSTERS SPREAD E/NE ACROSS MT. ...NORTHEAST SD/EASTERN ND/NORTHWEST MN... STRONG/SEVERE THUNDERSTORMS CONTINUE IN VICINITY OF PREFRONTAL TROUGH AND SOUTHWARD MOVING WEAK COLD FRONT ACROSS ND. 00Z OBSERVED ABERDEEN RAOB IS INDICATIVE OF THE MODERATELY UNSTABLE/ADEQUATELY SHEARED AIRMASS ACROSS THE FAR EASTERN DAKOTAS/NORTHWEST MN...WHICH REMAINS FAVORABLE FOR SUPERCELLS WITH A PRIMARY HAZARD OF LARGE HAIL. AN ISOLATED TORNADO MAY REMAIN POSSIBLE OVER THE NEXT HOUR OR TWO GIVEN THE BACKED SOUTHEASTERLY LOW LEVEL FLOW/INCREASING LOW LEVEL JET AND A SUFFICIENTLY MOIST AIRMASS. WITH THE SOUTHERN EXTENT ACROSS SOUTHEAST ND/NORTHEAST SD LARGELY TIED TO THE DIURNAL CYCLE...THE MOST SUSTAINED ACTIVITY IS LIKELY TO PERSIST ACROSS NORTHWEST MN AS SHORTWAVE TROUGH SPREADS EAST OF THE SURFACE TROUGH/INSTABILITY AXIS. CONSULT WW 724 AND RELATED MESOSCALE DISCUSSIONS FOR THE LATEST DETAILS REMAINDER OF THE NIGHT. ...SOUTHERN LA/FAR SOUTHEAST TX... WITH THE THUNDERSTORM COMPLEX SPREADING WEST ACROSS THE SABINE RIVER EARLY THIS EVENING...LOSS OF DAYTIME HEATING AND STABILIZING AFFECTS OF CONVECTIVE OUTFLOWS WILL LEAD TO A DIMINISHING MICROBURST/HAIL THREAT. ..GUYER/KERR.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 05:47:56 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 01:47:56 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 170547 SWODY1 SPC AC 170546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT THU AUG 17 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN/TONIGHT ACROSS PARTS OF THE NORTHERN PLAINS.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVE ACROSS PARTS OF THE CNTRL PLAINS/MID MS VLY.... SUBTROPICAL RIDGE ENCOMPASSING MUCH OF THE CENTRAL AND SOUTHERN TIER OF THE U.S. WILL REMAIN STRONG THROUGH MUCH OF THIS FORECAST PERIOD. HOWEVER...WEAKENING OF THIS FEATURE MAY COMMENCE TOWARD THE END OF THE PERIOD ...AS A SIGNIFICANT SHORT WAVE TROUGH... EMBEDDED WITHIN A BELT OF STRONGER WESTERLIES ACROSS CANADA... FINALLY SHIFTS EAST OF SASKATCHEWAN/MANITOBA. THIS SYSTEM WILL BE TRAILED CLOSELY BY A SHORT WAVE TROUGH IN A WEAKER SOUTHERN STREAM...ACROSS THE NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES AND NORTHERN PLAINS. ADDITIONALLY...WEAK BROAD TROUGHING IN THE SUBTROPICAL WESTERLIES IS FORECAST TO CONTINUE AROUND THE NORTHERN PERIPHERY OF THE UPPER RIDGE...PROGRESSING EAST OF THE MID MISSOURI VALLEY THROUGH THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION. SEVERAL OTHER IMPULSES WILL MIGRATE THROUGH THE ANTICYCLONIC FLOW AROUND THE OZARK PLATEAU SUBTROPICAL HIGH CENTER...FROM THE SOUTHERN ROCKIES INTO THE CENTRAL PLAINS...AND ACROSS THE GULF STATES. ALL OF THESE FEATURES...IN CONJUNCTION WITH SEASONABLE INSTABILITY ...WILL CONTRIBUTE TO SCATTERED THUNDERSTORM ACTIVITY TODAY/TONIGHT. MUCH OF THE COUNTRY WILL BE AFFECTED...WITH THE MOST NOTABLE EXCEPTIONS THE NORTHEAST...STILL UNDER THE INFLUENCE OF RECENT COOL/DRY INTRUSION...AND THE PACIFIC COAST STATES/GREAT BASIN...ASSOCIATED WITH DRYING TO THE SOUTH/WEST OF NORTHERN INTERMOUNTAIN TROUGH. ...CENTRAL PLAINS INTO MID MISSISSIPPI VALLEY... IN THE WAKE OF THE SUBTROPICAL IMPULSE...A CONFLUENT LOW/MID-LEVEL FLOW REGIME WITH A BELT OF 20 TO 30+ KT FLOW IS EXPECTED TO PERSIST FROM PARTS OF NORTHERN KANSAS ACROSS THE MISSOURI/IOWA BORDER AREA THROUGH MUCH OF THE DAY. THIS WILL AID FORWARD PROPAGATION OF CONVECTIVE DEVELOPMENT...WHICH IS EXPECTED TO INITIATE IN A WARM ADVECTION REGIME ALONG/NORTH OF A LOW-LEVEL THERMAL RIDGE AXIS...MOST LIKELY NEAR/SHORTLY AFTER PEAK AFTERNOON HEATING. A HOT...DEEP MIXED BOUNDARY LAYER ON THE SOUTHERN FRINGE OF A SUBTROPICAL MOISTURE PLUME SHOULD PROVE FAVORABLE FOR DOWNBURSTS...AND POTENTIALLY DAMAGING SURFACE GUSTS...WHICH COULD BECOME FAIRLY NUMEROUS BEFORE STORMS WEAKEN WITH LOSS OF HEATING THIS EVENING. ...NORTHERN PLAINS... FAVORABLE OROGRAPHY NEAR THE BLACK HILLS MAY PROVIDE THE LONE/ PRIMARY FORCING TO SUPPORT CONVECTIVE PRIOR TO 22-23Z TODAY...AS WARM MID-LEVEL TEMPERATURES PROVIDE SUBSTANTIAL CAP. IF ACTIVITY DOES DEVELOP...MODERATELY STRONG SOUTHWESTERLY MID-LEVEL FLOW WILL CONTRIBUTE TO FAVORABLE SHEAR FOR ISOLATED SUPERCELLS IN AN ENVIRONMENT WITH STEEP MID-LEVEL LAPSE RATES AND CAPE AROUND 2000 J/KG. THEREAFTER...INCREASING LARGE-SCALE ASCENT ASSOCIATED WITH THE APPROACH OF UPPER TROUGH/STRENGTHENING SOUTHERLY LOW-LEVEL JET MAY SUPPORT INCREASING CONVECTIVE DEVELOPMENT ALONG A SURFACE FRONT... EXTENDING ACROSS NORTHERN SOUTH DAKOTA INTO VICINITY OF SURFACE LOW TO THE LEE OF THE NORTH CENTRAL ROCKIES. ACTIVITY PROBABLY WILL INITIATE IN THE MOIST POST-FRONTAL UPSLOPE FLOW REGIME ACROSS SOUTHEAST MONTANA/PARTS OF NORTHEAST WYOMING...AND COULD CONSOLIDATE INTO AN ORGANIZED CONVECTIVE CLUSTER EASTWARD ALONG FRONT TONIGHT. IF THIS OCCURS...THERMODYNAMIC PROFILES FAVORABLE FOR EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...AND DOWNBURSTS/SURFACE COLD POOL DEVELOPMENT...WILL SUPPORT POTENTIAL FOR DAMAGING WIND GUSTS. LARGE HAIL IS ALSO POSSIBLE. ..KERR/BOTHWELL.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 12:49:47 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 08:49:47 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171249 SWODY1 SPC AC 171248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT THU AUG 17 2006 VALID 171300Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN MT ACROSS PARTS OF THE DAKOTAS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF KS...NEB...IA...AND MO... ...NORTHERN PLAINS... ZONAL FLOW PATTERN WILL PERSIST ACROSS THE NORTHERN U.S. TODAY... WITH SERIES OF SHORTWAVE TROUGHS MOVING FROM THE NORTHERN ROCKIES TO THE GREAT LAKES. ONE STRONG TROUGH IS CURRENTLY OVER PARTS OF ORE/ID...AND IS FORECAST TO TRACK EASTWARD ACROSS MT THIS AFTERNOON AND EVENING. THE AIRMASS OVER THE NORTHERN PLAINS /EASTERN MT INTO ND/ WILL REMAIN QUITE MOIST TODAY JUST NORTH OF SURFACE BAROCLINIC ZONE. POCKETS OF AFTERNOON HEATING IN THIS AREA...COUPLED WITH EASTERLY/UPSLOPE FLOW WILL HELP TO INITIATE AFTERNOON THUNDERSTORMS OVER THE BLACK HILLS AND BIGHORN MTNS OF MT/WY/SD. VERTICAL SHEAR PROFILES IN THIS AREA WILL PROMOTE SUPERCELL STRUCTURES CAPABLE OF HAIL AND DAMAGING WINDS. LIMITED FORCING FOR UPWARD VERTICAL MOTION WILL LIKELY LIMIT AREAL COVERAGE OF THUNDERSTORMS UNTIL AFTER DARK. DURING THE EVENING...UPPER TROUGH WILL APPROACH FROM THE WEST. STRONGER FORCING WILL OVERSPREAD WESTERN EDGE OF DEEPER LOW LEVEL MOISTURE OVER SOUTHEAST MT AND NORTHEAST WY. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THIS AREA AND PROPAGATE EASTWARD INTO PARTS OF THE DAKOTAS OVERNIGHT. CAPE/SHEAR PARAMETERS AND STRENGTH OF UPPER FORCING SUGGEST THAT SUPERCELLS/BOWS WILL BE POSSIBLE THROUGHOUT THE NIGHT WITH DAMAGING WINDS AND HAIL IN STRONGER STORMS. ...KS/NEB/IA/MO... WEAK SURFACE BOUNDARY CURRENTLY EXTENDS FROM SOUTH CENTRAL NEB INTO MO. THIS BOUNDARY IS FORECAST TO LIFT NORTHWARD TODAY...WITH MOIST/UNSTABLE AIRMASS SOUTH OF FRONT SPREADING ACROSS MUCH OF NEB/IA. STRONG DAYTIME HEATING WILL LEAD TO STEEP LOW LEVEL LAPSE RATES AND MODERATE INSTABILITY /MLCAPE VALUES OVER 2500 J/KG/. MORNING WATER VAPOR IMAGERY SHOWS PLUME OF MID LEVEL MOISTURE FROM THE TX PANHANDLE INTO SOUTHEAST NEB. COMBINATION OF CONVERGENCE NEAR RETREATING BOUNDARY...FAVORABLE MID LEVEL MOISTURE...AND FULL SUNSHINE WILL HELP TO INITIATE THUNDERSTORMS FROM EASTERN KS/NEB INTO WESTERN IA/MO THIS AFTERNOON. THESE STORMS MAY MOVE AS FAR EAST AS THE MISSISSIPPI RIVER THIS EVENING BEFORE WEAKENING. LOCALLY GUSTY/DAMAGING WINDS ARE EXPECTED IN STRONGER STORMS. ..HART/LEVIT.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 16:12:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 12:12:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 171610 SWODY1 SPC AC 171608 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1108 AM CDT THU AUG 17 2006 VALID 171630Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS NERN WY/SERN MT EWD ACROSS SD AND SRN ND...... ...SERN MT/NRN WY EWD ACROSS DAKOTAS... COLD UPPER TROUGH CURRENTLY CROSSING NRN ROCKIES PRECEEDED BY MODERATE SWLY FLOW AT MID LEVELS ACROSS NRN PLAINS. OVERNIGHT A COLD FRONT MOVED EWD ACROSS ND AND CURRENTLY EXTENDS FROM NWRN MN SWWD TO BLACK HILLS AND WWD ACROSS NRN WY. SURFACE LOW CENTRAL WY SHIFTS EWD INTO SWRN SD BY EVENING WITH NELY FLOW ALLOWING LOW LEVEL MOISTURE TO SPREAD INTO BIG HORN BASIN AND NERN WY. SURFACE HEATING COUPLED WITH THE UPSLOPE FLOW TO NORTH OF FRONTAL ZONE WILL SUPPORT STRONG/SEVERE THUNDERSTORM DEVELOPMENT FROM BIG HORN BASIN ENEWD ACROSS NERN WY/SERN MT INTO NWRN SD/SWRN ND BY MID/LATE AFTERNOON. SHEAR PROFILES WILL INCREASE TOWARD EVENING AS UPPER TROUGH APPROACHES AND LOW LEVEL JET TO S OF FRONTAL ZONE ACROSS NRN HIGH PLAINS INCREASES TO 25-30KT. SUPERCELLS WILL BECOME MORE LIKELY BY EVENING WITH THE INCREASINGLY FAVORABLE SHEAR AND UPWARD MOTION AHEAD OF THE APPROACHING TROUGH. PRIMARY THREAT WILL BE LARGE HAIL EARLY IN STORM EVOLUTION. DAMAGING WINDS WILL BECOME MORE LIKELY TOWARD EVENING AS STORMS DEVELOP UPSCALE INTO POSSIBLE MCS AND SHORT LINES. ANY TORNADO THREAT WITH SUPERCELLS SHOULD BE BRIEF AS BASES WILL BE RELATIVELY HIGH AND MLCAPES LIKELY NOT MUCH ABOVE 1500 J/KG. THREAT OF AT LEAST DAMAGING WINDS EXPECTED TO CONTINUE WELL AFTER DARK ACROSS DAKOTAS GIVEN THE UPPER WIND MAX TRANSLATING EWD ALONG ND/CANADA BORDER. ..HALES/GUYER.. 08/17/2006  From swody1 at goshenarc.org Thu Aug 17 20:04:48 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 16:04:48 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 172004 SWODY1 SPC AC 172002 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0302 PM CDT THU AUG 17 2006 VALID 172000Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN HIGH PLAINS AND INTO THE DAKOTAS... ...SERN MT/NERN WY INTO THE DAKOTAS... CUMULUS DEVELOPMENT CONTINUES ACROSS THE BLACK HILLS...WHERE STRONG BOUNDARY-LAYER HEATING IS RESULTING IN CONTINUED DESTABILIZATION /1000 TO 1500 J/KG MEAN-LAYER CAPE/. CAPPING INVERSION S OF W-E BAROCLINIC ZONE OVER SD SHOULD CONTINUE TO INHIBIT WARM-SECTOR CONVECTION. HOWEVER...STORMS SHOULD DEVELOP OVER THE BLACK HILLS -- AS WELL AS NEAR AND N OF SURFACE FRONT FROM NRN WY EWD INTO CENTRAL SD THIS AFTERNOON AND EVENING. AS LOW-LEVEL JET DEVELOPS THIS EVENING ACROSS THE HIGH PLAINS...STORMS SHOULD INCREASE IN COVERAGE -- AND POSSIBLY EVOLVE INTO ONE OR MORE MCS. THOUGH DEEP-LAYER SHEAR REMAINS LIMITED S OF FRONT...ELY LOW-LEVEL FLOW N OF FRONT COMBINED WITH INCREASE IN FLOW ALOFT AS UPPER TROUGH APPROACHES WILL YIELD SHEAR SUPPORTIVE OF SUPERCELLS. ALONG WITH THREAT FOR LARGE HAIL...LOCALLY-DAMAGING WINDS WILL ALSO BE POSSIBLE -- PARTICULARLY IF STORMS ORGANIZE ON THE MESOSCALE AS WARM ADVECTION INCREASES THIS EVENING. SEVERE THREAT APPEARS TO EXTEND WWD INTO NRN WY AND SWD ACROSS ERN WY...THOUGH LESS UNSTABLE AIRMASS SHOULD ACT TO LIMIT STORM INTENSITY. ..GOSS.. 08/17/2006  From swody1 at goshenarc.org Fri Aug 18 00:55:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 17 Aug 2006 20:55:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180054 SWODY1 SPC AC 180053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0753 PM CDT THU AUG 17 2006 VALID 180100Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NORTHERN PLAINS.... ...NORTHERN PLAINS... AN UPPER TROUGH IS BECOMING INCREASINGLY SHEARED AS IT ACCELERATES EASTWARD OUT OF THE NORTHERN INTERMOUNTAIN REGION. THIS IS OCCURRING AS A MORE SIGNIFICANT SHORT WAVE TROUGH...EMBEDDED WITHIN THE MAIN BELT OF WESTERLIES ACROSS CANADA...PROGRESSES EASTWARD INTO HUDSON BAY/ONTARIO. SURFACE FRONT ASSOCIATED WITH THE LATTER FEATURE IS ADVANCING INTO THE UPPER MISSISSIPPI VALLEY...BUT THE BOUNDARY HAS STALLED ACROSS PARTS OF NORTHERN SOUTH DAKOTA INTO NORTHEAST WYOMING...AWAITING THE APPROACH OF UPSTREAM SYSTEM. AS LARGE-SCALE UPWARD VERTICAL MOTION FIELD STRENGTHENS ALONG/JUST NORTH OF FRONT ACROSS NORTHWESTERN SOUTH DAKOTA THIS EVENING...POTENTIAL STILL EXISTS FOR THE DEVELOPMENT OF AN ORGANIZING MESOSCALE CONVECTION SYSTEM WITH RISK FOR DAMAGING WINDS/LARGE HAIL. VERTICAL SHEAR PROFILES ALONG FRONT ARE STRONG...VEERING FROM EASTERLY AT LOW-LEVELS TO MODERATELY STRONG WESTERLY AT MID/UPPER LEVELS...AND STEEP MID-LEVEL LAPSE RATES WILL MAINTAIN MOST UNSTABLE CAPE ON THE ORDER OF 1000-2000 J/KG. THIS MAY BE SUPPORTIVE OF SUPERCELL STRUCTURES BEFORE CONVECTION CONSOLIDATES LATER THIS EVENING/OVERNIGHT...GRADUALLY SPREADING EASTWARD ALONG FRONT ACROSS NORTHERN/CENTRAL SOUTH DAKOTA. ...CENTRAL PLAINS INTO MIDDLE MISSISSIPPI VALLEY... REMNANT BOUNDARY LEFT IN THE WAKE OF A SUBTROPICAL SHORT WAVE TROUGH... WHICH HAS SHIFTED EAST OF UPPER PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY INTO THE SOUTHERN GREAT LAKES REGION...IS BECOMING A FOCUS FOR INCREASING CONVECTIVE DEVELOPMENT ACROSS NORTHERN KANSAS...NEAR INTERSTATE 70. ACTIVITY SEEMS LIKELY TO PERSIST TONIGHT...PERHAPS AIDED BY FORCING ASSOCIATED WITH ANOTHER WEAK IMPULSE MIGRATING AROUND WESTERN/NORTHWESTERN PERIPHERY OF MID SOUTH SUBTROPICAL RIDGE. AND...DEVELOPMENT IS EXPECTED TO GRADUALLY SHIFT EAST NORTHEASTWARD THROUGH PARTS OF NORTHERN MISSOURI/SOUTHERN IOWA BY LATE TONIGHT...AS SOUTHERLY CENTRAL PLAINS LOW-LEVEL JET GRADUALLY VEERS. ALTHOUGH TIMING IS NOT OPTIMAL WITH THE ONSET OF DIURNAL BOUNDARY LAYER COOLING...UNSATURATED LOWER/MID-LEVEL PROFILES WILL ALLOW SUBSTANTIAL EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...CONTRIBUTING TO POTENTIAL FOR DOWNBURSTS AND AT LEAST A LOCALIZED DAMAGING WIND THREAT. ..KERR.. 08/18/2006  From swody1 at goshenarc.org Fri Aug 18 05:41:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 18 Aug 2006 01:41:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 180540 SWODY1 SPC AC 180539 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1239 AM CDT FRI AUG 18 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... SUBTROPICAL RIDGING WILL PERSIST ACROSS MUCH OF THE CENTRAL AND SOUTHERN TIER OF THE U.S. THROUGH THIS FORECAST PERIOD. HOWEVER...MODELS INDICATE THAT THE OZARK PLATEAU/MID SOUTH HIGH CENTER WILL GRADUALLY BEGIN TO BREAK DOWN/WEAKEN...IN RESPONSE TO THE PROGRESSION OF SHORT WAVE TROUGHS IN FASTER FLOW TO THE NORTH...AND ASSOCIATED INTRUSIONS OF COOLER AIR INTO THE NORTH CENTRAL STATES. THE MOST PROMINENT OF THESE SHORT WAVES...EMBEDDED WITHIN THE STRONGER BELT OF WESTERLIES ACROSS CANADA...IS PROGGED CONTINUE EAST OF HUDSON BAY/ONTARIO TODAY...WITH ANOTHER SYSTEM CONTINUING INLAND EAST OF THE CANADIAN ROCKIES. AS THIS OCCURS...AN INCREASINGLY SHEARED SHORT WAVE TROUGH IN A WEAKER SOUTHERN BRANCH OF POLAR WESTERLIES...IS PROGGED TO ADVANCE ACROSS THE NORTHERN PLAINS...AND INTO THE UPPER GREAT LAKES REGION BY EARLY SATURDAY MORNING. ...CENTRAL STATES... CONSIDERABLY COMPLICATING MATTERS...CONCERNING SEVERE POTENTIAL DURING THIS FORECAST PERIOD...IS SERIES OF WEAK IMPULSES EMBEDDED WITHIN SUBTROPICAL MOIST PLUME ADVECTING AROUND UPPER HIGH CENTER. MODELS SUGGEST THAT A CONVECTIVELY GENERATED/ENHANCED SURFACE BOUNDARY ASSOCIATED WITH THIS STREAM...LIKELY OVER NORTHERN KANSAS/NORTHERN MISSOURI AT THE OUTSET OF THE PERIOD...WILL ADVANCE SOUTHWARD INTO/THROUGH THE OZARKS/CENTRAL PLAINS DURING THE DAY. THIS MOVEMENT...INTO AREAS WELL SOUTH OF STRONGER FLOW ASSOCIATED WITH THE WESTERLIES...IS FORECAST TO OCCUR AS A SIGNIFICANT IMPULSE SHIFTS EAST OF THE MID/LOWER MISSOURI VALLEY TOWARD THE LOWER OHIO VALLEY. LOW-LEVEL CONVERGENCE WILL BECOME FOCUSED ALONG THIS BOUNDARY...WITH STRONGER SURFACE HEATING AND STEEPER LAPSE RATES BECOMING CONFINED TO AREAS TO THE SOUTH AND WEST...ACROSS MUCH OF KANSAS/SOUTHERN MISSOURI. DESPITE WEAK SHEAR AND UNCERTAIN MID/UPPER FORCING...MIXED LAYER CAPE IN EXCESS OF 2000 J/KG MAY SUPPORT SCATTERED VIGOROUS STORMS AS INHIBITION WEAKENS IN PEAK AFTERNOON HEATING ALONG/SOUTH OF BOUNDARY. LOCALIZED DOWNBURSTS WILL BE POSSIBLE IN STRONGER CONVECTION...BUT POTENTIAL FOR A SIGNIFICANT CONVECTIVE CLUSTER WITH BROADER SCALE DAMAGING WIND POTENTIAL SEEMS SMALL. ELSEWHERE...AHEAD OF UPPER IMPULSE...SCATTERED THUNDERSTORM ACTIVITY SEEMS LIKELY TO DEVELOP FROM PARTS OF THE MIDDLE MISSISSIPPI INTO THE LOWER OHIO VALLEY LATE THIS AFTERNOON. SHEAR WILL BE LIMITED...AND SURFACE HEATING/DESTABILIZATION NOT AS STRONG AS AREAS FARTHER WEST...BUT HIGH PRECIPITABLE WATER CONTENT OF AIR WILL BE FAVORABLE FOR LOCALLY HEAVY DOWNPOURS...PERHAPS LOCALIZED DOWNBURSTS. OTHER STRONG/LOCALLY SEVERE STORMS COULD OCCUR NEAR FRONTAL ZONE ASSOCIATED WITH SOUTHERN BRANCH TROUGH MIGRATING ACROSS THE NORTH CENTRAL STATES. THIS SEEMS MOST LIKELY EARLY IN THE DAY ACROSS PARTS OF SOUTHERN SOUTH DAKOTA/NORTHERN NEBRASKA...BEFORE LOW-LEVEL CONVERGENCE WEAKENS AS PRE-FRONTAL LOW-LEVEL FLOW VEERS TO A PROGGED NORTHERLY COMPONENT. ..KERR/BOTHWELL.. 08/18/2006  From swody1 at goshenarc.org Tue Aug 22 13:03:51 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 09:03:51 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221302 SWODY1 SPC AC 221300 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 AM CDT TUE AUG 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS... ...NRN PLAINS... AN UPPER-LEVEL DISTURBANCE ON WATER VAPOR IMAGERY OVER SW MT WILL MOVE INTO THE NRN PLAINS TODAY. IN RESPONSE TO THE DEVELOPING SHORTWAVE TROUGH...A 35-40 KT LOW-LEVEL JET IS FORECAST TO STRENGTHEN ACROSS SD RESULTING IN STRONG MOISTURE ADVECTION. THIS WILL HELP MOVE A WARM FRONT NEWD ACROSS ERN SD INTO WRN MN AS A DRY SLOT ADVECTS NEWD INTO SWRN SD. THE MOIST AXIS WITH 60 TO 65 F SFC DEWPOINTS SHOULD SET UP FROM SRN ND EXTENDING SEWD INTO NE SD AND SWRN MN. MODERATE INSTABILITY APPEARS LIKELY TO DEVELOP ALONG THE MOIST AXIS BY AFTERNOON. HOWEVER...THE LOCATION AND TIMING OF THUNDERSTORM INITIATION REMAINS HIGHLY UNCERTAIN. IT IS POSSIBLE THAT THUNDERSTORMS WILL INITIATE LATE THIS AFTERNOON ALONG THE WARM FRONT IN SCNTRL ND WHERE THE CAPPING INVERSION IS FORECAST TO BE WEAKER. EVEN THOUGH WARM AIR ALOFT WILL BE IN PLACE BEHIND THE DRY SLOT ACROSS SWRN SD...ISOLATED THUNDERSTORMS STILL MAY DEVELOP IN THE HIGHER TERRAIN OF THE BLACK HILLS. THE GREATEST POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS LIKELY TO OCCUR IN NE SD...SE ND AND WRN MN ALONG THE MOIST AXIS AFTER DARK AS THE LOW-LEVEL JET RAPIDLY STRENGTHENS THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS EVENING STRONGLY INCREASE DEEP LAYER SHEAR AS THE SHORTWAVE TROUGH APPROACHES. THIS SHOULD MAKE SUPERCELL DEVELOPMENT INCREASINGLY LIKELY AS STORM COVERAGE INCREASES THIS EVENING. THE POTENTIAL FOR SUPERCELLS APPEARS MOST LIKELY IN A CORRIDOR FROM NEAR FARGO ND EXTENDING EWD TO NEAR MINNEAPOLIS MN LATE THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF PRODUCING LARGE HAIL DUE TO THE STRONG DIRECTIONAL SHEAR AND STEEP MID-LEVEL LAPSE RATES IN PLACE. IN ADDITION...LOW-LEVEL SHEAR PROFILES WILL BE STRONG DUE TO THE LOW-LEVEL JET AND SUPERCELLS THAT BECOME ROOTED IN THE BOUNDARY LAYER MAY HAVE AN ISOLATED TORNADO POTENTIAL. WIND DAMAGE MAY ALSO OCCUR WITH CONVECTION THAT BECOMES SFC-BASED. ...COASTAL CAROLINAS... LATEST ANALYSIS SHOWS A NEARLY STATIONARY FRONT LOCATED ACROSS NRN NC WITH A SFC LOW IN THE MTNS OF WRN NC. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE LOWER 70S F AND THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP ACROSS THE ERN CAROLINAS BY MIDDAY. AS AN UPPER-LEVEL TROUGH MOVES EWD FROM THE SRN APPALACHIAN MTNS INTO THE COASTAL PLAINS LATE THIS AFTERNOON...SCATTERED STRONG THUNDERSTORMS APPEAR POSSIBLE. AS THE UPPER-TROUGH APPROACHES...VERTICAL SHEAR PROFILES SHOULD INCREASE JUST ENOUGH FOR STRONG AND POSSIBLE A FEW MARGINALLY SEVERE MULTICELLS. THE MAIN THREAT WOULD BE WIND DAMAGE DUE TO THE UNIDIRECTIONAL WIND PROFILES IN PLACE. ...ARIZONA... LATEST ANALYSIS SHOWS A MOIST AXIS IN PLACE ACROSS SRN AND CNTRL AZ WHERE DEWPOINTS ARE IN THE 60S F. AS SFC HEATING TAKES PLACE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG THE MOGOLLON RIM. CONVECTIVE COVERAGE WILL LIKELY BE THE GREATEST THIS EVENING AS STORMS MOVE WSWWD ACROSS SRN AND CNTRL AZ. STEEP LOW-LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW DAMAGING WIND GUSTS WITH THE STRONGER CELLS. ...UPSTATE NY/NH/VT/MAINE... A COLD FRONT WILL MOVE SEWD INTO THE NERN U.S. TODAY PROVIDING A FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT. STEEP LAPSE RATES ARE FORECAST TO BE IN PLACE AHEAD OF THE FRONT WHICH COMBINED WITH SFC HEATING MAY BE ENOUGH FOR A FEW STRONG WIND GUSTS WITH THE MORE ORGANIZED STORMS THIS AFTERNOON. ..BROYLES/GUYER.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 13:14:25 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 09:14:25 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221312 SWODY1 SPC AC 221311 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0811 AM CDT TUE AUG 22 2006 VALID 221300Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS... CORRECTED TO ADD 5 % HAIL LINE IN NRN PLAINS ...NRN PLAINS... AN UPPER-LEVEL DISTURBANCE ON WATER VAPOR IMAGERY OVER SW MT WILL MOVE INTO THE NRN PLAINS TODAY. IN RESPONSE TO THE DEVELOPING SHORTWAVE TROUGH...A 35-40 KT LOW-LEVEL JET IS FORECAST TO STRENGTHEN ACROSS SD RESULTING IN STRONG MOISTURE ADVECTION. THIS WILL HELP MOVE A WARM FRONT NEWD ACROSS ERN SD INTO WRN MN AS A DRY SLOT ADVECTS NEWD INTO SWRN SD. THE MOIST AXIS WITH 60 TO 65 F SFC DEWPOINTS SHOULD SET UP FROM SRN ND EXTENDING SEWD INTO NE SD AND SWRN MN. MODERATE INSTABILITY APPEARS LIKELY TO DEVELOP ALONG THE MOIST AXIS BY AFTERNOON. HOWEVER...THE LOCATION AND TIMING OF THUNDERSTORM INITIATION REMAINS HIGHLY UNCERTAIN. IT IS POSSIBLE THAT THUNDERSTORMS WILL INITIATE LATE THIS AFTERNOON ALONG THE WARM FRONT IN SCNTRL ND WHERE THE CAPPING INVERSION IS FORECAST TO BE WEAKER. EVEN THOUGH WARM AIR ALOFT WILL BE IN PLACE BEHIND THE DRY SLOT ACROSS SWRN SD...ISOLATED THUNDERSTORMS STILL MAY DEVELOP IN THE HIGHER TERRAIN OF THE BLACK HILLS. THE GREATEST POTENTIAL FOR THUNDERSTORM DEVELOPMENT APPEARS LIKELY TO OCCUR IN NE SD...SE ND AND WRN MN ALONG THE MOIST AXIS AFTER DARK AS THE LOW-LEVEL JET RAPIDLY STRENGTHENS THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION THIS EVENING STRONGLY INCREASE DEEP LAYER SHEAR AS THE SHORTWAVE TROUGH APPROACHES. THIS SHOULD MAKE SUPERCELL DEVELOPMENT INCREASINGLY LIKELY AS STORM COVERAGE INCREASES THIS EVENING. THE POTENTIAL FOR SUPERCELLS APPEARS MOST LIKELY IN A CORRIDOR FROM NEAR FARGO ND EXTENDING EWD TO NEAR MINNEAPOLIS MN LATE THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF PRODUCING LARGE HAIL DUE TO THE STRONG DIRECTIONAL SHEAR AND STEEP MID-LEVEL LAPSE RATES IN PLACE. IN ADDITION...LOW-LEVEL SHEAR PROFILES WILL BE STRONG DUE TO THE LOW-LEVEL JET AND SUPERCELLS THAT BECOME ROOTED IN THE BOUNDARY LAYER MAY HAVE AN ISOLATED TORNADO POTENTIAL. WIND DAMAGE MAY ALSO OCCUR WITH CONVECTION THAT BECOMES SFC-BASED. ...COASTAL CAROLINAS... LATEST ANALYSIS SHOWS A NEARLY STATIONARY FRONT LOCATED ACROSS NRN NC WITH A SFC LOW IN THE MTNS OF WRN NC. SOUTH OF THE BOUNDARY...DEWPOINTS ARE IN THE LOWER 70S F AND THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP ACROSS THE ERN CAROLINAS BY MIDDAY. AS AN UPPER-LEVEL TROUGH MOVES EWD FROM THE SRN APPALACHIAN MTNS INTO THE COASTAL PLAINS LATE THIS AFTERNOON...SCATTERED STRONG THUNDERSTORMS APPEAR POSSIBLE. AS THE UPPER-TROUGH APPROACHES...VERTICAL SHEAR PROFILES SHOULD INCREASE JUST ENOUGH FOR STRONG AND POSSIBLE A FEW MARGINALLY SEVERE MULTICELLS. THE MAIN THREAT WOULD BE WIND DAMAGE DUE TO THE UNIDIRECTIONAL WIND PROFILES IN PLACE. ...ARIZONA... LATEST ANALYSIS SHOWS A MOIST AXIS IN PLACE ACROSS SRN AND CNTRL AZ WHERE DEWPOINTS ARE IN THE 60S F. AS SFC HEATING TAKES PLACE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG THE MOGOLLON RIM. CONVECTIVE COVERAGE WILL LIKELY BE THE GREATEST THIS EVENING AS STORMS MOVE WSWWD ACROSS SRN AND CNTRL AZ. STEEP LOW-LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW DAMAGING WIND GUSTS WITH THE STRONGER CELLS. ...UPSTATE NY/NH/VT/MAINE... A COLD FRONT WILL MOVE SEWD INTO THE NERN U.S. TODAY PROVIDING A FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT. STEEP LAPSE RATES ARE FORECAST TO BE IN PLACE AHEAD OF THE FRONT WHICH COMBINED WITH SFC HEATING MAY BE ENOUGH FOR A FEW STRONG WIND GUSTS WITH THE MORE ORGANIZED STORMS THIS AFTERNOON. ..BROYLES.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 16:31:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 12:31:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221630 SWODY1 SPC AC 221629 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CDT TUE AUG 22 2006 VALID 221630Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NRN PLAINS... ...NRN PLAINS... PRESSURE FALLS WILL CONTINUE ACROSS THE NRN PLAINS TODAY AS SHORTWAVE TROUGHS TOP UPPER RIDGE AND SHIFT SEWD TOWARDS THE NRN MS RIVER VALLEY TONIGHT. THIS WILL ALLOW A WARM FRONT TO BECOME BETTER DEFINED FROM PORTIONS OF THE NRN MS RIVER VALLEY INTO THE UPPER MO RIVER VALLEY TODAY...WITH A WEAK LOW CENTER LIKELY EVOLVING INTO SWRN ND/NWRN SD/SERN MT. WARM SECTOR AIR MASS WILL BE MOISTENING THROUGH THE DAY WITH LOWER TO MID 60F SURFACE DEW POINTS POSSIBLE INTO SD BY THE LATE AFTERNOON. WITH STRONG SURFACE HEATING AND INCREASING ASCENT AHEAD OF WEAK SHORTWAVE TROUGH AND ALONG NOSE OF STRENGTHENING SSWLY LLJ...POTENTIAL FOR INITIATION WILL INCREASE LATER TODAY NEAR THE SURFACE FRONT. FORECAST SOUNDINGS INDICATE MLCAPE WILL EXCEED 2000 J/KG WITH WEAKENING CINH BY 21Z ALONG AND JUST SOUTH OF SURFACE WARM FRONT INTO N-CENTRAL SD/S-CENTRAL ND...WITH SUFFICIENT WNWLY FLOW ALOFT FOR 35-45 KT EFFECTIVE SHEAR. APPEARS ANY DIURNAL DEVELOPMENT WILL THEREFORE OCCUR WITHIN A FAVORABLE ENVIRONMENT FOR SURFACE-BASED SUPERCELLS INTO THE EVENING. EXPECT OVERALL INCREASE/EVOLUTION INTO A MCS ALONG NOSE OF STRENGTHENING LLJ THROUGH THE EVENING/OVERNIGHT NORTH OF THE SURFACE FRONT INTO PORTIONS OF ERN ND/NERN SD WHICH WILL SPREAD ESEWD INTO CENTRAL MN LATER TONIGHT. APPEARS THIS ACTIVITY WILL REMAIN ELEVATED...THOUGH STEEP MID LEVEL LAPSE RATES AND INFUSION OF 10-12C H85 DEW POINTS SHOULD SUSTAIN MODERATE MUCAPE. STRONG EFFECTIVE SHEAR IN EXCESS OF 45 KT WILL ALSO FAVOR ELEVATED SUPERCELLS AND ORGANIZED CLUSTERS/LINES...FURTHER INCREASING THE POTENTIAL FOR LARGE HAIL. DAMAGING WIND THREAT LATER TONIGHT WILL DEPEND ON DEGREE OF BOUNDARY LAYER STABILIZATION...THOUGH ISOLATED DAMAGING WINDS MAY OCCUR. ..EVANS/TAYLOR.. 08/22/2006  From swody1 at goshenarc.org Tue Aug 22 19:58:17 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Tue, 22 Aug 2006 15:58:17 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 221957 SWODY1 SPC AC 221956 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0256 PM CDT TUE AUG 22 2006 VALID 222000Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE DAKOTAS AND CNTRL/SRN MN... ...DAKOTAS TO MN... STRONG WARM AIR ADVECTION AND DESTABILIZATION WERE UNDERWAY BENEATH STOUT WARM SECTOR CAPPING ACROSS SD ATTM. SURFACE WARM FRONT WAS RECENTLY ANALYZED BISECTING SD FROM NW TO SE WITH LATEST DIAGNOSTIC DATA INDICATING MLCAPE IN EXCESS OF 2000 J/KG ALONG AND SOUTH OF THE FRONT. WHILE SUBTLE SHORT WAVE IMPULSE APPEARS TO BE DEVELOPING EAST ACROSS ERN MT AND WRN DAKOTAS ATTM...IT REMAINS TO BE SEEN WHETHER BACKGROUND ASCENT ASSOCIATED THIS FEATURE CAN OVERCOME MODEST AND PERSISTENT WARM SECTOR INHIBITION. RECENT CU TRENDS ACROSS THE BLACK HILLS SUGGEST AT LEAST ISOLATED HIGH TERRAIN DEVELOPMENT SHOULD OCCUR OVER THE NEXT FEW HOURS AND...GIVEN INTENSE SURFACE HEATING AND MIXING ACROSS THE BADLANDS...SOME OF THIS ACTIVITY MAY SURVIVE AND SPREAD EAST WITH ATTENDANT WIND AND LARGE HAIL HAZARDS THROUGH EARLY EVENING. SEVERE STORM DEVELOPMENT APPEARS A BIT MORE CERTAIN NEAR AND NORTH OF THE WARM FRONT...FROM NERN SD INTO SRN ND INTO THIS EVENING. AS LOW LEVEL INHIBITION IS WEAKENED THROUGH PERSISTENT BOUNDARY LAYER HEATING...AND MID LEVEL WARMING IS POTENTIALLY OFFSET BY WEAK LARGE SCALE ASCENT...EXPECT CHANCES FOR CONVECTIVE INITIATION TO INCREASE. STORMS DEVELOPING NORTH OF THE SURFACE WARM FRONT SHOULD REMAIN ELEVATED. HOWEVER...PROXIMITY OF STRONG INSTABILITY AND MORE THAN ADEQUATE EFFECTIVE BULK SHEAR WILL LEAD TO ROBUST UPDRAFTS AND PERHAPS A COUPLE OF SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. IF CELLS CAN DEVELOP OR TRACK NEAR THE WARM FRONT AND TAP NEAR SURFACE PARCELS...ISOLATED TORNADO AND DOWNBURST WIND THREATS COULD ENSUE. MAJORITY OF GUIDANCE INDICATES THAT AN MCS SHOULD EVOLVE FROM EVENING CONVECTION AND THIS SYSTEM WILL SPREAD EWD/ESEWD INTO MN THROUGH THE NIGHT SUSTAINED IN PART BY STRONG MASS INFLOW ON THE NOSE OF PLAINS LLJ. SEVERE WIND AND HAIL MAY ACCOMPANY THIS CONVECTION WELL INTO THE NIGHT ACROSS WRN/CNTRL AND SRN MN. ...SOUTH/SOUTHEAST... WIDESPREAD PULSE AND MULTICELL CONVECTION WAS UNDERWAY ALONG RESIDUAL FRONTAL AND OUTFLOW BOUNDARIES...AND SEA AND GULF BREEZES...FROM ERN NC SWWD TO LA/TX. ISOLATED WET DOWNBURST WINDS MAY DEVELOP WITH THIS CONVECTION AS IT MOVES INTO POCKETS OF STRONG LATE AFTERNOON INSTABILITY. ...SOUTHWEST... WEAK MID LEVEL DISTURBANCE ROTATING AROUND WRN/SWRN EDGE OF SUBTROPICAL HIGH WAS AIDING HIGH-TERRAIN TSTM DEVELOPMENT FROM SRN CA TO NRN PARTS OF AZ. MUCH OF SRN AZ REMAINS SHROUDED BY DEEP LAYER CLOUD COVER THAT WAS INHIBITING DESTABILIZATION ACROSS THESE AREAS. EXPECT CHANCES FOR DOWNBURST WINDS TO INCREASE IN THE NEXT FEW HOURS OVER AREAS THAT HAVE UNDERGONE STRONG HEATING... PRIMARILY FROM THE HIGHER ELEVATIONS OF SRN CA AND SRN NV...ACROSS PARTS OF CNTRL AND NRN AZ. ...SRN LWR MI...ERN GREAT LAKES...NORTHEAST... COLD FRONT WAS MOVING INTO WARM AND WEAKLY UNSTABLE AIR MASS FROM LOWER MI EWD ACROSS NRN NEW ENGLAND THIS AFTERNOON. A STORM OR TWO ALONG THE ADVANCING BOUNDARY COULD BRIEFLY ATTAIN SEVERE LEVELS WITH THE POTENTIAL FOR LOCALLY STRONG WIND GUSTS OR MARGINALLY SEVERE HAIL. ..CARBIN.. 08/22/2006  From swody1 at goshenarc.org Wed Aug 23 05:49:37 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 01:49:37 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 230547 SWODY1 SPC AC 230546 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CDT WED AUG 23 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS VLY... ...SYNOPSIS... THE NRN STREAM WILL REMAIN ACTIVE ON WEDNESDAY. SEVERAL SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW WILL MOVE ACROSS THE NRN/HIGH PLAINS AND BE THE IMPETUS FOR EPISODIC TSTM CLUSTERS. LEAD SYSTEM OVER THE DAKS WILL TRANSLATE SEWD INTO THE LWR GRTLKS REGION BY WED EVE. AN UPSTREAM STRONGER TROUGH IS EXPECTED TO MOVE INLAND ACROSS THE PAC NW EARLY WED...THEN MOVE INTO THE NRN INTERMOUNTAIN WEST WED NIGHT. AHEAD OF THIS SYSTEM...A WEAKER IMPULSE SHOULD MOVE ACROSS THE NRN DAKS AND THE CANADIAN PRAIRIES WED AFTN. IN THE LWR-LVLS...TAIL END OF A FRONT WILL BE IN PLACE FROM THE MIDWEST NWWD INTO THE UPPER MS VLY WHILE A LEE TROUGH EXISTS FROM THE CNTRL DAKS SWD INTO THE CNTRL HIGH PLAINS THROUGH THE PERIOD. A NEW FRONT WILL GAIN STRENGTH ACROSS THE NRN INTERMOUNTAIN WEST AND NRN ROCKIES BY EARLY THU. ...UPPER MS VLY... SWLY LLJ AXIS IMPINGING ON THE NW-SE ORIENTED FRONT WILL BE FEEDING A WED MORNING MCS ACROSS PORTIONS OF THE UPPER MS VLY. ASSOCD OUTFLOW WILL REINFORCE THE BAROCLINIC ZONE THROUGH WED AFTN ACROSS NRN IL NWWD INTO SWRN MN. THE SHORTWAVE TROUGH/MCV WILL QUICKLY MOVE SEWD AND LIKELY OUTRUN THE SUPPLY OF STEEP LAPSE RATES. AS A RESULT...THE MCS WILL LIKELY DIMINISH/WEAKEN AS IT MOVES SEWD TOWARD THE MIDWEST/CNTRL GRTLKS REGION. OUTFLOW BOUNDARY/FRONT WILL GRADUALLY RECOVER AND MOVE NEWD WED AFTN. AIR MASS SW OF THE FRONT WILL BECOME QUITE UNSTABLE AS STEEP MID-LEVEL LAPSE RATES STREAM EWD FROM THE PLAINS AND SFC DEW POINTS REMAIN IN THE UPPER 60S. THERE IS A HIGH DEGREE OF UNCERTAINTY ON WHETHER SFC-BASED TSTMS WILL DEVELOP ALONG THE FRONT GIVEN LACK OF APPARENT LARGE SCALE ASCENT. BUT...REGION WILL REMAIN ALONG NE EDGE OF THE STRONGER CAP. LOCAL CONVERGENCE ALONG THE FRONT AND STRONG HEATING MAY CONTRIBUTE TO INITIATION FROM CNTRL/SRN MN INTO SWRN WI AND NRN IL BY MID-AFTN. GIVEN A STORM...THE 40-50 KT OF VERTICAL SHEAR WILL BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL...DAMAGING WINDS AND PERHAPS AN ISOLD TORNADO. LOW CONFIDENCE IN INITIATION ARGUES FOR LOW-END SLGT RISK/LOW SVR PROBABILITIES ATTM. ...NRN DAKS INTO NRN MN... ISOLD TSTMS MAY BACKBUILD/DEVELOP ACROSS SRN MANITOBA/SASK SWD INTO THE NRN DAKS ALONG A LEE TROUGH WED AFTN. CINH WILL BE AN ISSUE...PARTICULARITY ACROSS SD...BUT WEAK HEIGHT FALLS ASSOCD WITH A WEAK IMPULSE AND STRONG HEATING ALONG THE EDGE OF THE ELEVATED MIXED LAYER WILL WEAKEN THE CAP. MOST ACTIVITY SHOULD REMAIN N OF THE INTERNATIONAL BORDER...BUT GIVEN A STORM...SUPERCELLS WILL BE POSSIBLE WITH PRIMARILY LARGE HAIL. AFTER DARK...ELEVATED BANDS OF STORMS MAY EVOLVE/DEVELOP FARTHER NE INTO NRN MN WITH PERHAPS ISOLD LARGE HAIL. LOW PROBABILITIES WILL BE MAINTAINED AS COVERAGE IS EXPECTED TO BE ISOLD. ...NRN HIGH PLAINS/ROCKIES... STRONGER ASCENT WILL SPREAD NEWD ACROSS MT/WRN ND WED NIGHT AS UPPER TROUGH AND HEIGHT FALLS DEVELOP ACROSS THE REGION. LINEAR CONVECTIVE DEVELOPMENT MAY OCCUR ALONG THE LEADING EDGE OF THIS ASCENT. ISOLD DAMAGING WINDS MAY OCCUR WITH THE STRONGER STORMS...BUT MOISTURE WILL BE QUITE LIMITED IN THE BOUNDARY LAYER. ..RACY/GUYER.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 13:04:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 09:04:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231302 SWODY1 SPC AC 231301 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0801 AM CDT WED AUG 23 2006 VALID 231300Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MIDWEST AND NRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN ND... ...UPPER MIDWEST/NRN PLAINS... A SHORTWAVE TROUGH OVER IL THIS MORNING WILL MOVE SEWD INTO THE OH VALLEY WITH A SHORTWAVE RIDGE MOVING INTO THE UPPER MIDWEST TODAY. AT THE SFC...ANALYSIS SHOWS A NEARLY STATIONARY FRONT EXTENDING ESEWD FROM SRN MN INTO THE CHICAGO IL AREA WITH SFC DEWPOINTS ALONG THE BOUNDARY IN THE LOWER TO MID 60S F. THIS SHOULD ALLOW MODERATE TO STRONG INSTABILITY TO DEVELOP ALONG AND TO THE SOUTHWEST OF THE BOUNDARY. HOWEVER...WARM AIR ALOFT AND A STRONG CAPPING INVERSION OVER THE WARM SECTOR WILL LIKELY KEEP CONVECTIVE DEVELOPMENT MINIMAL FROM FAR WRN MN EXTENDING SWD ACROSS ERN SD...WRN IA AND ERN NEB. THE CAPPING INVERSION SHOULD BE WEAKER JUST NORTH AND EAST OF THE STATIONARY FRONT ESPECIALLY BY EVENING. THE MOST LIKELY SPOT FOR INITIATION APPEARS TO BE ACROSS SRN MN AND/OR SCNTRL WI EARLY THIS EVENING WHERE MODEL FORECASTS SHOW ENHANCED LOW-LEVEL CONVERGENCE. IF MCS DEVELOPMENT OCCURS...THE MOST LIKELY TRACK WOULD BE SEWD INTO NRN IL AND POSSIBLY INTO FAR SW LOWER MI LATER TONIGHT. THE THUNDERSTORM ACTIVITY SHOULD REMAIN MOSTLY ELEVATED. HOWEVER...FORECAST SOUNDINGS ALONG THIS ZONE SHOW STRONG DEEP LAYER SHEAR WITH 0-6 KM SHEAR VALUES REACHING 50-60 KT. IN ADDITION...MID-LEVEL LAPSE RATES ARE FORECAST TO EXCEED 7.5 C/KM WHICH COMBINED WITH STRONG FLOW FROM THE LOW-LEVEL JET MAY BE FAVORABLE FOR SUPERCELLS AND/OR BOW ECHOES WITH HAIL AND ISOLATED WIND DAMAGE POSSIBLE. FURTHER NORTHWEST ACROSS NRN ND...THE UPPER-LEVEL RIDGE WILL LIKELY PREVENT CONVECTIVE DEVELOPMENT THIS AFTERNOON. HOWEVER...THUNDERSTORMS SHOULD DEVELOP EARLY THIS EVENING NEAR A SFC LOW FORECAST TO BE LOCATED IN FAR SRN SASKATCHEWAN. FORECAST SOUNDINGS IN THIS AREA SHOW ADEQUATE DIRECTIONAL SHEAR AND STRONG SPEED SHEAR IN THE LOWER TO MID-LEVELS. THIS COMBINED WITH VERY STEEP LASE RATES SHOULD RESULT IN A HIGH POTENTIAL FOR ROTATING STORMS WITH HAIL POTENTIAL. IF SUPERCELLS MOVE SEWD INTO NRN ND EARLY THIS EVENING...LARGE HAIL WILL BE VERY LIKELY. ...SRN PLAINS... LATEST ANALYSIS SHOWS A DIFFUSE STATIONARY FRONT LOCATED FROM FAR NE OK EXTENDING ESEWD ACROSS NE TX AND NRN LA. DEWPOINTS ALONG AND SOUTH OF THE BOUNDARY ARE IN THE LOWER TO MID 70S F WHICH SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY BY AFTERNOON. AS THUNDERSTORMS DEVELOP NEAR THE BOUNDARY THIS AFTERNOON...STEEP LOW-LEVEL LAPSE RATES ESPECIALLY IN NE TX WILL MAKE STRONG WIND GUSTS LIKELY WITH THE STRONGER MULTICELL STORMS. ...GA/SC/FL.. SCATTERED THUNDERSTORMS WILL DEVELOP TODAY ALONG AND SOUTH OF A NEARLY STATIONARY FRONT LOCATED ACROSS CNTRL AL...CNTRL GA AND SC. DEWPOINTS IN THE LOWER 70S F SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY. THIS COMBINED WITH STEEPENING LOW-LEVEL LAPSE RATES BY MID-AFTERNOON SHOULD BE ENOUGH FOR STRONG WIND GUSTS WITH SOME CELLS NEAR PEAK HEATING. ...AZ... LATEST SFC ANALYSIS SHOWS A MOIST AXIS EXTENDING NWWD ACROSS SCNTRL AZ WHERE DEWPOINTS ARE IN THE LOWER TO MID 60S F. THIS SHOULD ALLOW MODERATE INSTABILITY TO DEVELOP WITH SCATTERED THUNDERSTORM INITIATION LIKELY OCCURRING ALONG THE MOGOLLON RIM BY LATE AFTERNOON. ALTHOUGH FORECAST SOUNDINGS SHOW RELATIVELY WEAK SHEAR PROFILES...0-3 KM LAPSE RATES SHOULD EXCEED 9.0 C/KM IN SOME AREAS MAKING STRONG WIND GUSTS LIKELY WITH THE SOME CELLS EARLY THIS EVENING. ..BROYLES/GUYER.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 16:35:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 12:35:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231634 SWODY1 SPC AC 231633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT WED AUG 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... ...NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... FAVORABLE LOW LEVEL WAA REGIME WILL REMAIN IN PLACE TODAY ATOP SURFACE OUTFLOW BOUNDARY/WARM FRONT WHICH EXTENDS FROM NERN IL/SERN WI NWWD TO SURFACE LOW ALONG THE ND-SD BORDER THIS MORNING. THIS BOUNDARY WILL MOVE LITTLE THROUGH THE AFTERNOON...WHILE STRONG HEATING AT THE SURFACE AND WARMING THROUGH H7 OCCURS ACROSS THE WARM SECTOR. APPEARS WSWLY H85 FLOW FROM 30-40 KT WILL PERSIST FOR MUCH OF THE DAY INTO THE NRN MS RIVER VALLEY AND CONTINUE DEVELOPING ELEVATED THUNDERSTORMS ALONG NERN EDGE OF MID LEVEL CAPPING ACROSS WRN/CENTRAL WI. MID LEVEL LAPSE RATES ARE QUITE STEEP AND FEED OF MODERATE INSTABILITY WILL SUPPORT STRONG UPDRAFTS...FURTHER ENHANCED BY 40-50 KT EFFECTIVE SHEAR...SUGGESTING ISOLATED LARGE HAIL MAY OCCUR WITH THIS ACTIVITY. SEVERE THREAT MAY INCREASE LATER THIS AFTERNOON AS STRONG SURFACE HEATING ALONG EDGE OF H7 THERMAL RIDGE OCCURS NEAR THE SURFACE FRONT OVER THE NRN MS RIVER VALLEY. FORECAST SOUNDINGS INDICATE CAP MAY WEAKEN SUFFICIENTLY FOR SURFACE-BASED DEVELOPMENT WITHIN AN ENVIRONMENT CHARACTERIZED BY 1500+ J/KG MLCAPE AND 40-50 KT DEEP LAYER SHEAR. THEREFORE...SUPERCELLS AND POSSIBLY ISOLATED TORNADOES/VERY LARGE HAIL WOULD BE FAVORED SHOULD SURFACE-BASED DEVELOPMENT OCCUR. OTHERWISE...EXPECT EVOLUTION INTO ANOTHER STRONG/SEVERE MCS WHICH WILL SPREAD ESEWD ACROSS THE CENTRAL GREAT LAKES AHEAD OF SHORTWAVE TROUGH NOW SHIFTING EWD ACROSS NERN MT/SRN SASK. HAVE ADJUSTED SLGT RISK AREA INTO PORTIONS OF SWRN MI TO ACCOUNT FOR THIS SCENARIO WHERE FORECAST SOUNDINGS LATER TONIGHT YIELD MUCAPE AROUND 1500 J/KG AND SUFFICIENT CLOUD-LAYER SHEAR FOR ROTATING UPDRAFTS. AS WAS THE CASE LAST NIGHT...MCS COULD BOW INTO A LINE THOUGH WIND DAMAGE POTENTIAL WILL DEPEND ON HOW STABLE THE BOUNDARY LAYER REMAINS. ATTM...EXPECT PRIMARY THREAT WILL BE FROM LARGE HAIL. ..EVANS/TAYLOR.. 08/23/2006  From swody1 at goshenarc.org Wed Aug 23 17:34:06 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 13:34:06 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 231732 SWODY1 SPC AC 231633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT WED AUG 23 2006 VALID 231630Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... ...NRN MS RIVER VALLEY INTO THE CENTRAL GREAT LAKES... FAVORABLE LOW LEVEL WAA REGIME WILL REMAIN IN PLACE TODAY ATOP SURFACE OUTFLOW BOUNDARY/WARM FRONT WHICH EXTENDS FROM NERN IL/SERN WI NWWD TO SURFACE LOW ALONG THE ND-SD BORDER THIS MORNING. THIS BOUNDARY WILL MOVE LITTLE THROUGH THE AFTERNOON...WHILE STRONG HEATING AT THE SURFACE AND WARMING THROUGH H7 OCCURS ACROSS THE WARM SECTOR. APPEARS WSWLY H85 FLOW FROM 30-40 KT WILL PERSIST FOR MUCH OF THE DAY INTO THE NRN MS RIVER VALLEY AND CONTINUE DEVELOPING ELEVATED THUNDERSTORMS ALONG NERN EDGE OF MID LEVEL CAPPING ACROSS WRN/CENTRAL WI. MID LEVEL LAPSE RATES ARE QUITE STEEP AND FEED OF MODERATE INSTABILITY WILL SUPPORT STRONG UPDRAFTS...FURTHER ENHANCED BY 40-50 KT EFFECTIVE SHEAR...SUGGESTING ISOLATED LARGE HAIL MAY OCCUR WITH THIS ACTIVITY. SEVERE THREAT MAY INCREASE LATER THIS AFTERNOON AS STRONG SURFACE HEATING ALONG EDGE OF H7 THERMAL RIDGE OCCURS NEAR THE SURFACE FRONT OVER THE NRN MS RIVER VALLEY. FORECAST SOUNDINGS INDICATE CAP MAY WEAKEN SUFFICIENTLY FOR SURFACE-BASED DEVELOPMENT WITHIN AN ENVIRONMENT CHARACTERIZED BY 1500+ J/KG MLCAPE AND 40-50 KT DEEP LAYER SHEAR. THEREFORE...SUPERCELLS AND POSSIBLY ISOLATED TORNADOES/VERY LARGE HAIL WOULD BE FAVORED SHOULD SURFACE-BASED DEVELOPMENT OCCUR. OTHERWISE...EXPECT EVOLUTION INTO ANOTHER STRONG/SEVERE MCS WHICH WILL SPREAD ESEWD ACROSS THE CENTRAL GREAT LAKES AHEAD OF SHORTWAVE TROUGH NOW SHIFTING EWD ACROSS NERN MT/SRN SASK. HAVE ADJUSTED SLGT RISK AREA INTO PORTIONS OF SWRN MI TO ACCOUNT FOR THIS SCENARIO WHERE FORECAST SOUNDINGS LATER TONIGHT YIELD MUCAPE AROUND 1500 J/KG AND SUFFICIENT CLOUD-LAYER SHEAR FOR ROTATING UPDRAFTS. AS WAS THE CASE LAST NIGHT...MCS COULD BOW INTO A LINE THOUGH WIND DAMAGE POTENTIAL WILL DEPEND ON HOW STABLE THE BOUNDARY LAYER REMAINS. ATTM...EXPECT PRIMARY THREAT WILL BE FROM LARGE HAIL. ..EVANS/TAYLOR.. 08/23/2006  From swody1 at goshenarc.org Thu Aug 24 01:11:36 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 23 Aug 2006 21:11:36 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240110 SWODY1 SPC AC 240109 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0809 PM CDT WED AUG 23 2006 VALID 240100Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE UPPER MS VALLEY AND UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF WRN ND... ...UPPER MS VALLEY THROUGH UPPER GREAT LAKES AREA... EARLY THIS EVENING A QUASISTATIONARY FRONT EXTENDS FROM A WEAK LOW IN CNTRL SD ESEWD THROUGH SRN MN...SRN WI...NRN IND AND EWD THROUGH THE OH VALLEY. THE ATMOSPHERE S OF FRONT REMAINS VERY UNSTABLE WITH STEEP LAPSE RATES AND MLCAPE FROM 4000 J/KG ACROSS SRN MN TO AROUND 1500 J/KG ACROSS NRN IND. STORMS CONTINUE NEAR AND JUST N OF THE BOUNDARY FROM S CNTRL WI SEWD INTO NRN IND. CURRENT THINKING IS THAT STORMS WILL CONTINUE DEVELOPING OVER CNTRL AND S CNTRL WI NEXT FEW HOURS AND SPREAD SEWD AS WLY LOW LEVEL JET ENHANCES ISENTROPIC LIFT AND THETA-E ADVECTION ON COOL SIDE OF FRONT. STORMS THAT DEVELOP AND TRACK SEWD NEAR THE FRONT WILL BE CLOSE ENOUGH TO SURFACE BASED FOR A CONTINUING ISOLATED TORNADO THREAT NEXT FEW HOURS WITH ANY DISCRETE SUPERCELL STRUCTURES. HOWEVER...SOME STORMS MAY ALSO EVOLVE INTO SMALL CLUSTERS AND BOWS AS THEY SPREAD SEWD. GIVEN THE STEEP LAPSE RATES...STRONG INSTABILITY AND FAVORABLE VERTICAL SHEAR FOR SUPERCELLS...SOME STORMS MAY BE CAPABLE OF PRODUCING VERY LARGE HAIL. FARTHER W ACROSS SRN MN WHERE THE STRONGER INSTABILITY EXISTS...THE 00Z RAOB FROM MINNEAPOLIS AS WELL AS LACK OF BOUNDARY LAYER CUMULUS CONFIRM THAT THE ATMOSPHERE IS STILL CAPPED IN THIS AREA. LIFT MAY INCREASE ALONG MN PORTION OF THE BOUNDARY LAYER THIS EVENING AS THE LOW LEVEL JET STRENGTHENS. HOWEVER...GIVEN THE CAP IN PLACE...CONFIDENCE IS NOT HIGH THAT STORMS WILL BE ABLE TO DEVELOP MUCH FARTHER W THAT CURRENT ONGOING ACTIVITY. ...ND... ISOLATED HIGH BASED STORMS HAVE DEVELOP IN THE DEEPLY MIXED REGIME ACROSS WRN ND. LOW LEVEL THERMODYNAMIC PROFILES WITH LARGE TEMPERATURE/DEWPOINT SPREADS AND STEEP LAPSE RATES WILL SUPPORT A THREAT OF ISOLATED DAMAGING WIND. SOME HAIL MAY ALSO ACCOMPANY THE STRONGER STORMS. FORCING FOR ASCENT WILL INCREASE ACROSS WRN ND TOWARD THE END OF THIS PERIOD AS A STRONG SHORTWAVE TROUGH APPROACHES FROM THE W. THREAT FOR ELEVATED STORMS CAPABLE OF PRODUCING HAIL WILL BE THE MAIN THREAT. ..DIAL.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 06:01:15 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 02:01:15 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 240601 SWODY1 SPC AC 240600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT THU AUG 24 2006 VALID 241200Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF ERN SD THROUGH CNTRL AND SRN MN AND EXTREME NRN IA... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE NRN AND CNTRL PLAINS THROUGH THE UPPER MS VALLEY AREA... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE OH VALLEY THROUGH MID ATLANTIC AND NERN U.S.... ...SYNOPSIS... STRONG SHORTWAVE TROUGH OVER THE NRN ROCKY MOUNTAIN REGION WILL MOVE EWD INTO THE NRN PLAINS AND UPPER MS VALLEY THIS PERIOD...RESULTING IN LEE CYCLOGENESIS AND DEAMPLIFICATION OF SHORTWAVE RIDGE. A MORE SUBTLE LEAD VORT MAX CURRENTLY OVER SRN MT WILL MOVE EWD IN ADVANCE OF THE MAIN UPPER TROUGH. A COLD FRONT WILL ACCOMPANY THE SHORTWAVE TROUGH INTO THE NRN PLAINS. BY EARLY THURSDAY THE FRONT WILL EXTEND FROM ERN MT SWWD THROUGH ERN WY. THIS BOUNDARY ALONG WITH DEVELOPING LEE CYCLONE WILL ADVANCE EWD THROUGH THE DAKOTAS DURING THE DAY. A QUASISTATIONARY FRONT WILL EXTEND FROM THE LOW OVER SD EWD THROUGH SRN MN AND SRN WI. ...NRN PLAINS THROUGH UPPER MS VALLEY AREA... RESERVOIR OF UNTAPPED INSTABILITY WILL PERSIST OVER PORTIONS OF SD INTO SRN MN GENERALLY NEAR AND S OF E-W FRONT. BOUNDARY LAYER IN WARM SECTOR WILL MOST LIKELY REMAIN CAPPED BY A STRONG EML MUCH OF THE DAY. STORMS MAY BE ONGOING EARLY THURSDAY N OF FRONT MOSTLY ACROSS ND AS FORCING FOR ASCENT ACCOMPANYING LEAD SHORTWAVE TROUGH INCREASES. DOWNSTREAM FROM THIS ACTIVITY AND ESPECIALLY S OF E-W FRONT FROM CNTRL AND ERN SD INTO SRN MN...THE ATMOSPHERE SHOULD BECOME VERY UNSTABLE AS SURFACE HEATING COMMENCES. STORMS MAY INITIALLY INTENSIFY ALONG EWD ADVANCING COLD FRONT. STRONG LINEAR FORCING ENHANCED BY DEEP LAYER ASCENT ACCOMPANYING EWD ADVANCING SHORTWAVE TROUGH MAY RESULT IN ACTIVITY EVOLVING INTO A LINEAR MCS. HOWEVER...SOME SUPERCELL STRUCTURES WILL BE POSSIBLE ESPECIALLY ALONG SRN END OF THE LINE. DAMAGING WIND AND LARGE HAIL WILL BE THE MAIN THREATS...BUT AN ISOLATED TORNADO OR TWO WILL ALSO BE POSSIBLE WITH ANY SUPERCELL MODES WITHIN THE LINE. FARTHER EAST...ASCENT ASSOCIATED WITH LEAD SHORTWAVE TROUGH AND A BRANCH OF THE LOW LEVEL JET E OF SURFACE LOW WILL MAINTAIN FORCING FOR ASCENT ALONG AND N OF THE E-W STATIONARY FRONT. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP NEAR AND JUST N OF THE BOUNDARY AS THE CAP WEAKENS DURING THE AFTERNOON. ESELY LOW LEVEL FLOW NEAR FRONT VEERING TO WSWLY AND INCREASING TO 40+ KT AT 6 KM WILL CONTRIBUTE TO FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR PROFILES FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES. VERY LARGE HAIL AND A FEW TORNADOES WILL BE POSSIBLE WITH ANY DISCRETE SUPERCELLS THAT DEVELOP NEAR THIS BOUNDARY. OVERNIGHT...STORMS MAY EVOLVE INTO ONE OR MORE MCSS AS THE LOW LEVEL JET INCREASES WITH A CONTINUING THREAT FOR MAINLY DAMAGING WIND AND LARGE HAIL FROM THE UPPER MS VALLEY INTO PARTS OF THE GREAT LAKES. ...OH VALLEY THROUGH MID ATLANTIC AND NERN STATES... STORMS MAY STILL BE IN PROGRESS IN WARM ADVECTION REGIME FROM PARTS OF SRN LOWER MI INTO NRN OH EARLY THURSDAY. POTENTIAL WILL EXIST FOR SOME OF THIS ACTIVITY TO BECOME SURFACE BASED AS THE DOWNSTREAM ATMOSPHERE DESTABILIZES. PRIMARY THREAT WILL BE DAMAGING WIND AS ACTIVITY ADVANCES ESEWD. OTHER STORMS MAY DEVELOP DOWNSTREAM OVER PARTS OF THE MID ATLANTIC AS THE ATMOSPHERE DESTABILIZES AND AS VORT MAX ROTATES SEWD THROUGH BASE OF UPPER TROUGH. BOUNDARY LAYER FLOW WILL BE RATHER WEAK...BUT DEEP LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR UPDRAFT ROTATION. POOR MID LEVEL LAPSE RATES AND MODEST INSTABILITY WILL LIMIT OVERALL HAIL POTENTIAL. HOWEVER...THE STRONGER STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS. ..DIAL/GUYER.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 16:34:33 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 12:34:33 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 241635 SWODY1 SPC AC 241633 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1133 AM CDT THU AUG 24 2006 VALID 241630Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF ERN SD...SRN MN AND EXTREME WRN WI... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK ACROSS THE NRN AND CENTRAL PLAINS AND THE UPPER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS IN DELMARVA... ...SYNOPSIS... POTENT SHORTWAVE TROUGH MOVING INTO WRN ND WILL SHIFT EWD INTO NRN MN TONIGHT. SURFACE LOW OVER WRN SD AND ASSOCIATED N-S COLD FRONT IS FORECAST TO MOVE EWD INTO THE ERN DAKOTAS/CENTRAL NEB BY EARLY EVENING..AND THEN INTO MN/WRN IA TONIGHT. SURFACE LOW MOVING SHOULD MAINTAIN CURRENT POSITION OF WARM FRONT THROUGH THE AFTERNOON FROM EAST CENTRAL SD ESEWD ACROSS FAR SRN MN TO NEAR THE IL/WI BORDER. CONVERGENCE ALONG WARM FRONT SHOULD BE ENHANCED BY STRONG HEATING SOUTH AND CLOUDS/COOLER TEMPERATURES NORTH OF THE BOUNDARY. OTHER THUNDERSTORMS ARE ALSO POSSIBLE ALONG EWD EXTENSION OF FRONT FROM THE UPPER MIDWEST INTO THE MID ATLANTIC STATES. ...NRN PLNS INTO UPR MS VLY... WIDESPREAD DAMAGING WIND EVENT AND POSSIBLY STRONG TORNADOES ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT...ESPECIALLY ACROSS THE MODERATE RISK AREA. LARGE AREA OF CLOUDS ACROSS MOST OF THE DAKOTAS WILL REDUCE THE AMOUNT OF HEATING ACROSS THIS AREA THIS AFTERNOON. HOWEVER...STRONG FORCING HAS ALREADY RESULTED IN ELEVATED SEVERE THUNDERSTORMS ACROSS WRN ND IN ASSOCIATION WITH LARGE SCALE FORCING. DESPITE STABLE BOUNDARY...EFFECTIVE SHEAR NEAR 50 KT AND MUCAPES IN EXCESS OF 3000 J/KG...AS OBSERVED ON BIS MORNING SOUNDING...WILL BE FAVORABLE FOR SUPERCELLS TO MOVE/DEVELOP SEWD ALONG INSTABILITY AXIS TOWARD SERN ND/NRN SD. DESPITE RELATIVELY STABLE BOUNDARY LAYER...THE DEGREE OF SHEAR/INSTABILITY WILL BE FAVORABLE FOR SEVERE HAIL/WINDS. OTHER ELEVATED STORMS ARE ALSO LOCATED ACROSS SERN MN/WRN WI IN ASSOCIATION WITH WARM ADVECTION NORTH OF WARM FRONT. DEEP LAYER SHEAR AND STRONG INSTABILITY ALSO FAVOR SEVERE HAIL/WINDS WITH THESE STORMS AS THEY GRADUALLY MOVE/DEVELOP SEWD. SURFACE BASED STORMS ARE MOST LIKELY TO DEVELOP NEAR THE WARM FRONT ACROSS ERN SD/SWRN MN WHERE STRONG HEATING SHOULD RESULT IN AN EXTREMELY UNSTABLE AIR MASS WITH MLCAPES IN EXCESS OF 4000 J/KG. WARM 700 MB TEMPERATURES BETWEEN 14-16C SHOULD KEEP THIS AREA CAPPED MOST OF THE DAY...THOUGH THIS LAYER WILL COOL AS LARGE SCALE FORCING SPREADS INTO THE REGION. THE POTENTIAL EXISTS FOR STORMS TO FIRST DEVELOP N OF THE BOUNDARY AS THE CAP SHOULD ERODE MORE RAPIDLY NORTH OF THE BOUNDARY. THOUGH THESE STORMS WOULD BE SLIGHTLY ELEVATED...THE STORMS MAY QUICKLY EVOLVE INTO A LINE/BOW AND THEN MOVE ESEWD. WIDESPREAD WIND DAMAGE WOULD BE POSSIBLE GIVEN THE DEGREE OF INSTABILITY AND DEEP LAYER SHEAR. EVENTUALLY...SURFACE BASED STORMS ARE EXPECTED TO DEVELOP NEAR THE WARM FRONT LATE THIS AFTERNOON. THE EXTREME INSTABILITY AND 60 KT DEEP LAYER SHEAR WILL RESULT IN THE RAPID DEVELOPMENT OF SUPERCELLS. ANY DISCRETE SUPERCELLS THAT CAN BE MAINTAINED NEAR THE WARM FRONT WILL INGEST A MOIST BOUNDARY LAYER WITH 25-30 KT 1 KM SHEAR...WHICH WOULD BE SUPPORTIVE OF STRONG TORNADOES LATE THIS AFTERNOON/EVENING. AS THE LOW LEVEL JET STRENGTHENS THIS EVENING ...THE SUPERCELLS SHOULD EVOLVE INTO A LINE/BOW AND MOVE ESEWD ALONG WARM FRONT ACROSS SRN MN AND INTO WI...WITH THE MAIN THREAT BECOMING DAMAGING WIND GUSTS...WITH SOME POSSIBLY EXTREME. ...NEB... HIGH BASED THUNDERSTORMS ARE ALSO POSSIBLE ALONG SRN EXTENSION OF COLD FRONT FROM SERN SD SWWD ACROSS NEB LATE THIS AFTERNOON. DEEP LAYER SHEAR AROUND 30 KT AND DEWPOINT DEPRESSIONS NEAR 50F WOULD SUPPORT STRONG WIND GUSTS. ...DELMARVA... ABUNDANT SUNSHINE WAS PREVALENT ACROSS THE REGION AND SHOULD RESULT IN AT LEAST MODERATE INSTABILITY THIS AFTERNOON. GIVEN WEAK FRONTAL BOUNDARY AND WEAK IMPULSES MOVING EWD THROUGH THE AREA...A FEW STRONG STORMS WITH MARGINALLY SEVERE WIND GUSTS ARE POSSIBLE THIS AFTERNOON. ..IMY/TAYLOR.. 08/24/2006  From swody1 at goshenarc.org Thu Aug 24 20:00:12 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 16:00:12 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 242000 SWODY1 SPC AC 241958 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0258 PM CDT THU AUG 24 2006 VALID 242000Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER PARTS OF NERN SD...SERN ND...CNTRL/SRN MN AND W-CNTRL WI... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE DAKOTAS INTO PARTS OF THE UPPER GREAT LAKES... ...DAKOTAS INTO THE UPPER GREAT LAKES... COMPLEX SCENARIO IS EVOLVING TODAY ACROSS THE REGION IN ADVANCE OF STRONG SHORT WAVE TROUGH TRANSLATING EWD THROUGH WRN/CNTRL ND. WATER VAPOR IMAGERY SUGGESTS THAT A LEAD IMPULSE IS CURRENTLY SHIFTING EWD THROUGH CNTRL/ERN SD WHICH IS LIKELY SUPPORTING THE ONGOING STORMS FROM FAR NERN SD INTO CNTRL MN. IN THE LOW-LEVELS...PRIMARY SURFACE LOW APPEARS TO BE W OF MBG WITH ATTENDANT WARM FRONT EXTENDING SEWD TO NEAR HON AND THEN ACROSS SRN MN TO NEAR THE WI/IL BORDER. A SECONDARY SURFACE LOW WAS ANALYZED ALONG THIS BOUNDARY N OR NE OF FSD WITH A TRAILING PRE-FRONTAL TROUGH STRETCHING SWWD FROM THIS LOW INTO CNTRL NEB. MEANWHILE...COLD FRONT /CURRENTLY MASKED BY ADIABATIC DOWNSLOPE WARMING/ EXTENDED FROM NEAR MOT TO PHP INTO THE NEB PNHDL. THUS FAR TODAY...PRIMARY SEVERE IN THE FORM OF ELEVATED SUPERCELLS PRODUCING LARGE /AND AT TIMES SIGNIFICANT/ HAIL HAS PERSISTED FROM CNTRL MN INTO SRN WI IN ASSOCIATION WITH LOW-LEVEL WAA/ISENTROPIC ASCENT REGIME N OF WARM FRONT. BOTH 12Z AND 18Z REGIONAL SOUNDINGS INDICATE THAT INFLOW PARCEL SOURCE REGION OVER THE MID MO VALLEY INTO SRN MN REMAINS MODERATE TO STRONGLY UNSTABLE WITH MUCAPES OF 2500-4500 J/KG. STRENGTHENING SWLY LLJ THIS AFTERNOON AND TONIGHT SHOULD MAINTAIN CLUSTERS OF ELEVATED SUPERCELLS TO THE N OF SURFACE BOUNDARY WITH VERY LARGE HAIL BEING THE MAIN SEVERE THREAT. OTHER SURFACE-BASED STORMS WILL BECOME INCREASINGLY LIKELY LATE THIS AFTERNOON INTO EVENING FROM SERN SD EWD ACROSS SRN MN NEAR AND E OF TRIPLE POINT ASSOCIATED WITH SECONDARY SURFACE LOW. MODERATELY STRONG LOW-LEVEL SHEAR /0-1 KM SRH OF 100-200 M2/S2/ COUPLED WITH THE MODERATE TO STRONG INSTABILITY AND 40-50 KTS OF EFFECTIVE BULK SHEAR INDICATE THE POTENTIAL FOR SUPERCELLS CAPABLE OF A FEW TORNADOES...LARGE HAIL AND DAMAGING WINDS SHOULD STORMS DEVELOP AND BECOME SUSTAINED. FARTHER DOWNSTREAM...TSTM COMPLEX OVER SRN WI WILL POSE A DAMAGING WIND/LARGE HAIL THREAT AS IT CONTINUES SEWD ALONG BAROCLINIC ZONE ACROSS SERN WI/NERN IL. MEANWHILE...A LARGE CLUSTER OF TSTMS INCLUDING EMBEDDED SUPERCELLS CONTINUES TO INCREASE IN COVERAGE AND INTENSITY THIS AFTERNOON OVER PORTIONS OF WRN AND CNTRL ND...IMMEDIATELY AHEAD OF SHORT WAVE TROUGH. VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT AIR MASS IS RECOVERING AHEAD OF THIS ACTIVITY OVER N-CNTRL SD INTO S-CNTRL ND WHERE STRONGER DIABATIC HEATING HAS ALLOWED TEMPERATURES TO WARM INTO THE 80S...SUPPORTING MLCAPES OF 1500-3000 J/KG. WHILE THERE HAS BEEN SOME TENDENCY FOR STORMS TO EVOLVE INTO A MORE LINEAR CONFIGURATION...POTENTIAL STILL EXISTS FOR MORE DISCRETE SUPERCELLS ALONG SRN PORTION OF COMPLEX NEAR SURFACE LOW AND ATTENDANT WARM FRONT WITH A THREAT OF A FEW TORNADOES AS WELL AS LARGE HAIL AND DAMAGING WINDS. THERE IS SOME UNCERTAINTY AS TO HOW FAR S STORMS WILL FORM INTO CNTRL SD OWING TO CLOSE PROXIMITY OF LEAD SHORT WAVE TROUGH OVER ERN SD. LATEST VISIBLE IMAGERY DOES INDICATE DEEPENING CUMULUS ALONG COLD FRONT SW OF MBG AND SSE PHP. SHOULD STORMS DEVELOP AND BECOME SUSTAINED THE COMBINATION OF MODERATE TO STRONG INSTABILITY AND MODERATELY STRONG VERTICAL SHEAR WILL BE SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES CAPABLE OF LARGE HAIL...DAMAGING WINDS AND PERHAPS A COUPLE OF TORNADOES. ..MEAD.. 08/24/2006  From swody1 at goshenarc.org Fri Aug 25 01:04:38 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 24 Aug 2006 21:04:38 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250105 SWODY1 SPC AC 250103 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0803 PM CDT THU AUG 24 2006 VALID 250100Z - 251200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM SOUTHEAST SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND PARTS OF SOUTHWEST WISCONSIN... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM ERN SD TO LAKE MI SWD TO KS AND WRN MO... ...VOLATILE SEVERE WEATHER SITUATION CONTINUING ACROSS EASTERN SOUTH DAKOTAS...SOUTHERN MINNESOTA...AND WESTERN WISCONSIN THIS EVENING... COMPACT AND FAST MOVING MID LEVEL IMPULSE AND ASSOCIATED 50-60KT WLY SPEED MAX WILL CONTINUE TO DRIVE DANGEROUS SEVERE WEATHER EPISODE ACROSS PARTS OF THE NRN PLAINS/UPPER MS VALLEY INTO TONIGHT. A PLUME OF EXTREMELY UNSTABLE AIR /MLCAPE IN EXCESS OF 5000 J PER KG/ CONTINUES TO WRAP INTO THE WARM SECTOR OF ASSOCIATED VIGOROUS SURFACE CYCLONE MOVING EWD ALONG INTENSE WARM FRONT FROM ERN SD AND SRN MN. IN ADDITION TO VERY MOIST AND HIGHLY UNSTABLE AIR MASS...PRONOUNCED DIRECTIONAL SHEAR EXISTS NEAR OUTFLOW-REINFORCED WARM FRONT OVER SRN MN...WHERE LATEST DIAGNOSTIC DATA INDICATES 0-1KM SRH GREATER THAN 250 M2/S2. THESE CONDITIONS WILL CONTINUE TO FUEL INTENSE SUPERCELLS WITH TORNADOES...HIGH WINDS...AND VERY LARGE HAIL OVER PORTIONS OF SERN SD INTO SCNTRL MN THIS EVENING. ONGOING TORNADIC SUPERCELL WAS RECENTLY MOVING NEAR HURON SD AND APPEARS TO BE LOCATED IN CLOSE PROXIMITY TO SYNOPTIC SURFACE LOW. DAMAGING TORNADOES WERE ALSO RECENTLY REPORTED IN NICOLLET AND LE SEUR COUNTIES IN SCNTRL MN. TORNADIC SUPERCELLS OVER MN APPEAR TO HAVE FORMED ON THE INTENSE WARM FRONT SOUTH OF MSP. ADDITIONAL ELEVATED ACTIVITY WAS TRACKING NORTH OF THE WARM FRONT AND WILL CONTINUE TO PRODUCE HAIL AND LOCALLY STRONG WINDS FROM THE MSP AREA INTO WRN WI THIS EVENING. SD SUPERCELL MAY PERSIST WITHIN NARROW CORRIDOR BETWEEN RELATIVELY STRONG WARM SECTOR CAP ALONG/SOUTH OF THE SD/MN BORDERS...AND OUTFLOW AIR MASS NORTH OF THE WARM FRONT. HOWEVER...LATEST GUIDANCE APPEARS TO SUGGEST THAT CAP...TIME OF DAY...AND DEAMPLIFICATION OF UPPER WAVE...MAY BEGIN TO TEMPER SEVERE WEATHER POTENTIAL FROM SWRN MN INTO IA OVERNIGHT. DESPITE THESE INDICATIONS...LIFT ALONG THE COLD FRONT/WIND SHIFT WILL DEVELOP SEWD INTO THE INSTABILITY AXIS ACROSS THESE AREAS LATER TONIGHT. THIS WARRANTS MAINTAINING A SLGT RISK AND RELATIVELY LOW SEVERE PROBABILITIES OVER THE AREA AT THIS TIME. ...NEB/ERN KS/WRN MO... HOT AND MODERATELY UNSTABLE AIR MASS SHOULD PERSIST ACROSS THE CNTRL PLAINS AS FRONT/WIND SHIFT SPREADS SEWD OVERNIGHT. LATEST NAM-WRF AND NCEP-SREF WERE INDICATING A POTENTIAL FOR SCATTERED TSTM DEVELOPMENT AS THE FRONT MOVES SEWD. SHEAR ACROSS THE AREA APPEARS MARGINALLY SUPPORTIVE OF UPDRAFT PERSISTENCE AND IF A CLUSTER OR TWO OF STORMS CAN DEVELOP...MASS INFLOW ON THE PLAINS NOCTURNAL LOW LEVEL JET MAY BE ENOUGH TO SUSTAIN STORMS INTO EARLY FRIDAY FROM SERN KS INTO WRN MO. PROBABILITY OF HAIL AND HIGH WINDS WITH THIS POTENTIAL ACTIVITY APPEARS GREAT ENOUGH TO WARRANT A SLGT RISK ACROSS THE MO RIVER VALLEY FOR THE REST OF TONIGHT. ..CARBIN.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 05:57:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 01:57:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 250557 SWODY1 SPC AC 250556 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT FRI AUG 25 2006 VALID 251200Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE WRN GREAT LAKES/UPPER MIDWEST TO SRN PLAINS/HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE WRN GREAT LAKES FROM PA/NY TO NRN NJ... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL ROCKIES... ...SYNOPSIS... RELATIVELY HIGH-AMPLITUDE FLOW REGIME ACROSS SRN CANADA/NRN U.S. WILL MAINTAIN A BELT OF MODERATE CYCLONIC FLOW ACROSS THE UPPER MS VALLEY/WRN GREAT LAKES REGIONS THROUGH TODAY...WHILE SHARP DOWNSTREAM RIDGE BUILDS ACROSS ONTARIO AND WRN QUEBEC. WEAKER DOWNSTREAM IMPULSES...UNDERCUTTING THE RIDGE AXIS...WILL TRAVEL SEWD IN A BAND OF MODEST WNWLY MID LEVEL FLOW FROM THE ERN GREAT LAKES...ACROSS PA/NY...TO SRN NEW ENGLAND AND NJ. IN THE WEST...A POSITIVE-TILT UPPER TROUGH WILL DIG SEWD OVER THE NRN GREAT BASIN WITH HEIGHT FALLS AND DIFFLUENT MID/UPPER LEVEL FLOW SPREADING ACROSS THE NRN/CNTRL ROCKIES. SURFACE LOW ASSOCIATED WITH THE UPPER MS VALLEY/GREAT LAKES TROUGH WILL DEVELOP GENERALLY EWD ALONG A WARM FRONT FROM WI TO LOWER MI AS TRAILING COLD FRONT MAKES RELATIVELY SLOW PROGRESS EWD/SEWD ACROSS IA AND THE UPPER MIDWEST THROUGH SATURDAY MORNING. WRN EXTENSION OF THE FRONT WILL MOVE A BIT FASTER ACROSS THE SCNTRL PLAINS...AND PUSH WWD/SWWD INTO THE HIGHER TERRAIN FROM WY SWD ACROSS CO. A QUASI-STATIONARY WARM FRONTAL ZONE...ALIGNED WITH THE DEEP-LAYER WNWLY FLOW FROM THE LOWER/ERN GREAT LAKES TO SRN NEW ENGLAND/NJ WILL PROVIDE A NARROW CORRIDOR FOR ASCENT ACROSS THESE REGIONS THROUGH THE PERIOD. ...UPPER MIDWEST/GREAT LAKES... WARM AND VERY MOIST AIR MASS WILL CONTINUE TO BE INCORPORATED INTO ZONE OF PERSISTENT ASCENT AHEAD OF SURFACE LOW AND COLD FRONT THROUGH THE AFTERNOON. DAYTIME HEATING COUPLED WITH 65-75F DEWPOINTS WILL CONTRIBUTE TO MODERATE TO STRONG AFTERNOON DESTABILIZATION WITH MLCAPES OF 1500-3500 J/KG EXPECTED FROM CNTRL SRN WI/NRN IL SWWD ACROSS ERN IA. GIVEN WIDESPREAD CONVECTIVE DEBRIS BUT PERSISTING LIFT NORTH OF THE WARM FRONT...FROM CNTRL/NRN WI ACROSS MUCH OF MI...ELEVATED TSTMS CAPABLE OF MARGINALLY SEVERE HAIL MAY CONTINUE THROUGH THE DAY FRIDAY OVER THESE AREAS. MORE INTENSE...SURFACE-BASED STORM DEVELOPMENT APPEARS INCREASINGLY LIKELY BY AFTERNOON FROM VICINITY OF SURFACE LOW SWD ALONG COLD FRONT FROM CNTRL/SRN WI INTO NRN IL AS HEATING AND LARGE-SCALE FORCING FOR ASCENT EFFECTIVELY ERODE THE CAP. MODEST WLY FLOW ATOP THE DESTABILIZING AIR MASS WILL PROVIDE MORE THAN ADEQUATE VERTICAL SHEAR FOR SUPERCELL STORMS AND PERHAPS BOWING LINE SEGMENTS CAPABLE OF BOTH LARGE HAIL AND DAMAGING WINDS. TORNADO POTENTIAL APPEARS TO BE SLIGHTLY LOWER THAN THURSDAY WITH WEAKER/VEERED LOW LEVEL FLOW NEAR THE FRONT. HOWEVER...BETTER POTENTIAL FOR A TORNADO OR TWO MAY EVOLVE FROM STORMS DEVELOPING NEAR SURFACE LOW AND MOVING ALONG THE WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE ENHANCED. CELLS ENCOUNTERING POSSIBLE LAKE BREEZE BOUNDARY ACROSS ERN WI MAY ALSO POSE A THREAT FOR A BRIEF TORNADO OR TWO. FARTHER SW ALONG THE ADVANCING COLD FRONT...FROM ERN IA INTO ERN MO AND IL...DEEP LAYER SHEAR WILL DIMINISH. HOWEVER...STRONG DESTABILIZATION WILL DEVELOP BENEATH STOUT CAP. FRONTAL CIRCULATION MAY BE SUFFICIENT TO OVERCOME THE CAP WITH A FEW INTENSE STORMS POSSIBLE ACROSS THESE AREAS FROM LATE AFTERNOON INTO THE EVENING. ISOLATED HAIL AND STRONG/DAMAGING WINDS COULD ACCOMPANY THIS ACTIVITY. ...KS SWWD/WWD ACROSS THE PNHDLS INTO THE SRN HIGH PLAINS... STEEPENING LOW THROUGH MID-LEVEL LAPSE RATES AND MOIST BOUNDARY LAYER WILL COEXIST ALONG AND NORTH OF SURFACE FRONT/WIND SHIFT SETTLING SOUTH INTO THESE AREAS DURING THE AFTERNOON. MLCAPES OF 1500-2500 J/KG AND LOW LEVEL CONVERGENCE/MIXING ALONG THE FRONT WILL LEAD TO INCREASING TSTM COVERAGE AND INTENSITY. THIS WILL OCCUR COINCIDENT WITH A SLIGHT INCREASE IN SWLY MID LEVEL FLOW...AND ATOP LOW LEVEL ELY FLOW...THUS PROVIDING AN ENVIRONMENT WITH MARGINALLY SUPPORTIVE SHEAR FOR ORGANIZED AND PERSISTENT STORMS. LATEST GUIDANCE SUGGESTS THAT THIS CONVECTION WILL CONTINUE WELL INTO THE EVENING AND POSSIBLY EVOLVE INTO AN MCS ACROSS PARTS OF SRN KS/NRN OK. LOW LEVEL MASS INFLOW AND DEGREE OF INSTABILITY SHOULD SUSTAIN A SEVERE HAIL/WIND THREAT FROM THIS CONVECTION ACROSS THESE AREAS THROUGH EARLY SATURDAY. ...NCNTRL ROCKIES... HEIGHT FALLS...DIFFLUENT MID LEVEL FLOW...AND LOW LEVEL UPSLOPE FLOW WILL SPREAD ACROSS PARTS OF NRN UT/WRN WY AND CO DURING THE PERIOD OF PEAK HEATING. AS LARGE SCALE ASCENT IMPINGES ON SUBTROPICAL MOISTURE PLUME ACROSS THE AREA...STEEP LAPSE RATES AND MOISTENING WILL LEAD TO SUFFICIENT INSTABILITY FOR STRONG TO SEVERE STORMS. RELATIVELY HIGH-BASED SUPERCELLS WILL POSE A THREAT FOR HAIL AND HIGH WINDS. ...ERN GREAT LAKES ACROSS NY/PA TO NJ... NAM AND GFS INDICATE THAT SHORT WAVE IMPULSE UNDERCUTTING RIDGE AXIS ACROSS SRN ONTARIO WILL SPREAD EAST AND ENHANCE ASCENT ALONG THE STATIONARY FRONTAL ZONE FROM LAKE ERIE ACROSS NY/PA. VERTICAL SHEAR ALONG THE SURFACE FRONT WILL REMAIN QUITE FAVORABLE FOR SUPERCELLS THROUGH THE PERIOD GIVEN THE DEVELOPMENT AND MAINTENENCE OF CONVECTION. MODELS AGREE THAT MOST FAVORABLE JUXTAPOSITION OF DESTABILIZATION...FORCING...AND SHEAR MAY EVOLVE FROM WRN NY ACROSS NCNTRL PA THROUGH EARLY EVENING. SUPERCELL STORMS ACROSS THESE AREAS COULD BE CAPABLE OF PRODUCING HAIL AND POSSIBLY A TORNADO OR TWO. ..CARBIN/GUYER.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 12:50:59 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 08:50:59 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251250 SWODY1 SPC AC 251249 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT FRI AUG 25 2006 VALID 251300Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO EARLY TONIGHT FROM KS NEWD TO WI...THEN ESEWD TO NRN PA... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR NE UT/NW CO/SW WY... ...ERN IA/NW IL/SRN WI THIS AFTERNOON... A MID LEVEL TROUGH OVER THE CANADIAN PRAIRIES WILL PROGRESS EWD TO ONTARIO...WHILE THE SRN EXTENT OF THIS TROUGH MOVES EWD FROM MN THIS MORNING TO UPPER MI/LAKE SUPERIOR THIS EVENING WHILE GRADUALLY WEAKENING. AN ASSOCIATED SURFACE CYCLONE ACROSS SRN MN/NRN IA WILL MOVE EWD ACROSS SRN WI TO LAKE MI AND WEAKEN IN CONJUNCTION WITH DE-AMPLIFICATION OF THE MID LEVEL WAVE. A TRAILING COLD FRONT SHOULD CONTINUE SLOWLY SEWD ACROSS IA/NRN MO/KS THROUGH TONIGHT. FARTHER E...THE SURFACE PATTERN HAS BEEN COMPLICATED BY OUTFLOW FROM OVERNIGHT STORMS ACROSS SRN WI/NERN IA. AN OUTFLOW BOUNDARY EXTENDS FROM E CENTRAL IA INTO SE WI AS OF 11Z...WHILE THE PRIMARY BAROCLINIC ZONE IS LOCATED FARTHER N FROM CENTRAL WI ACROSS SRN LOWER MI. OVERNIGHT CONVECTION HAS EXHAUSTED MUCH OF THE STRONGER INSTABILITY...AND THE RICHER BOUNDARY LAYER MOISTURE /MID 60S OR GREATER/ IS CONFINED TO A NARROW CORRIDOR FROM ERN KS/WRN MO INTO IA. SOME RECOVERY WILL BE POSSIBLE THROUGH THIS AFTERNOON IN ADVANCE OF THE SURFACE LOW/COLD FRONT AND IN THE WAKE OF THE MORNING CONVECTION...AND A FEW THUNDERSTORMS MAY FORM FROM ERN IA INTO SRN WI. VERTICAL SHEAR AND LOW-MID LEVEL FLOW FIELDS ARE EXPECTED TO WEAKEN SLOWLY THROUGH THIS EVENING IN THE WARM SECTOR...THOUGH VERTICAL SHEAR MAY REMAIN AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS ACROSS WI THIS AFTERNOON. ...LOWER MI TO PA AREA THROUGH THIS EVENING... A BELT OF WEAK-MODERATE INSTABILITY IS EXPECTED TODAY ALONG A LOW-LEVEL BAROCLINIC ZONE FROM SRN LOWER MI INTO CENTRAL PA. DEBRIS CLOUDS MAY LIMIT SURFACE HEATING ACROSS LOWER MI EARLY TODAY...BUT A FEW THUNDERSTORM CLUSTERS ARE STILL EXPECTED INVOF THE SURFACE BOUNDARY. DEEP LAYER VERTICAL SHEAR WILL BE SUFFICIENT FOR BOTH SUPERCELLS AND BOWING SEGMENTS...THE STRONGEST OF WHICH COULD PRODUCE A FEW DAMAGING GUSTS AND MARGINALLY SEVERE HAIL. ...PLAINS AREA THIS AFTERNOON INTO EARLY TONIGHT... A BROAD AREA OF THUNDERSTORMS ASSOCIATED WITH LOW-LEVEL WAA AND A 40-50 KT LLJ IS ONGOING ACROSS MO TO THE E OF THE MOISTURE/INSTABILITY ACROSS FROM ERN OK INTO ERN KS. SURFACE HEATING AND BOUNDARY LAYER DEWPOINTS OF 65-70 F ALONG A SLOW MOVING COLD FRONT IN KS WILL RESULT IN MODERATE INSTABILITY BY AFTERNOON WHEN SURFACE-BASED THUNDERSTORM DEVELOPMENT IS EXPECTED. STEEP LOW-LEVEL LAPSE RATES AND MLCAPE VALUES OF 1500-2000 J/KG WILL SUPPORT A THREAT FOR WIDELY SCATTERED DOWNBURSTS AND SOME HAIL THIS AFTERNOON/EVENING ALONG AND S OF THE FRONT. N OF THE BOUNDARY...LOW-LEVEL NELY FLOW BENEATH 25-30 KT SWLY MID LEVEL FLOW WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR SOME SUPERCELL STRUCTURES FROM EXTREME SE CO ACROSS WRN/CENTRAL KS. CONVECTION WILL EVENTUALLY BECOME RATHER WIDESPREAD ALONG AND N OF THE FRONT...THUS THE SEVERE STORM THREAT IS EXPECTED TO DIMINISH BY LATE EVENING. ...NE UT/NW CO/SW WY AREA TODAY... THE MID LEVEL TROUGH OVER ERN ORE/WA AND ID THIS MORNING WILL DIG SLOWLY SEWD TOWARD NE NV/NW UT BY EARLY SATURDAY. ASCENT IN ADVANCE OF THE MID LEVEL TROUGH...ALONG WITH NW EDGE OF THE MONSOONAL MOISTURE PLUME...WILL SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT FROM NE UT INTO SW WY AND NW CO TODAY INTO EARLY TONIGHT. STEEP L0W-MID LEVEL LAPSE RATES...LOW-LEVEL DEWPOINTS OF 45-50 F...AND MODEST SWLY MID LEVEL FLOW SHOULD BE SUFFICIENT FOR A FEW STORMS WITH STRONG/DAMAGING OUTFLOW WINDS AND MARGINALLY SEVERE HAIL. ..THOMPSON/GUYER.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 16:49:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 12:49:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 251650 SWODY1 SPC AC 251648 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 AM CDT FRI AUG 25 2006 VALID 251630Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT LAKES REGION SEWD INTO THE NRN MID ATLANTIC AREA...AND ACROSS THE CENTRAL PLAINS.... ...SYNOPSIS... SEVERAL MID/UPPER LEVEL LOWS DEFINE THE PATTERN WITH ONE OVER THE NRN PLATEAU...ANOTHER OVER CENTRAL/SOUTH CENTRAL CANADA AND THE OTHER OVER CENTRAL/EASTERN QUEBEC. THIS PLACES THE MAIN STORM TRACK FROM NRN NEVADA NEWD THRU WY...THEN EWD ACROSS THE UPPER GREAT LAKES THEN SEWD THRU THE LOWER GREAT LAKES INTO THE NRN MID ATLANTIC REGION. THE LATEST SURFACE ANALYSIS EXTENDS A WARM FRONT FROM A LOW OVER SERN MN EWD/SEWD ACROSS SRN WI INTO SERN LOWER MI...THEN CONTINUES AS A QUASI STATIONARY FRONT THRU NERN OH THRU NRN NJ. IN ADDITION...A WEAK COLD FRONT EXTENDS FROM THE MN LOW SWWD ACROSS SWRN IA AND NERN KS THEN WWD THRU EXTREME SWRN KS AND SRN CO. ...SRN WI ESEWD ACROSS NERN OH INTO NJ... MODELS ARE ALL IN FAIR AGREEMENT OF DEVELOPING STRONG CONVECTION OVER PARTS OF SRN LOWER MI INTO NERN OH/NWRN PA AND AGAIN FROM NERN PA INTO NJ LATER THIS AFTERNOON AND TONIGHT. MODELS DO NOT DEVELOP ANY LOW LEVEL FLOW TOWARDS THE QUASI-STATIONARY BOUNDARY ACROSS THIS REGION...BUT DOES HAVE A FAVORABLE ENTRANCE REGION OF THE MID/UPPER LEVEL JET STREAK THAT IS FORECAST FROM SRN LK HURON OVER SWRN AND SERN NY. IT ALSO LOOKS LIKE THE MODELS WANT TO TAKE THE CONVECTION CURRENTLY OVER SRN WI AND TRACK IT EWD/SEWD INTO THIS AREA. THE 15Z RUC IS CONSISTENT WITH THIS SCENARIO...DESTABILIZING THE AIR MASS WITH SBCAPE BETWEEN 1500-2000 J/KG WITH DEEP LAYER SHEAR OF 45-55 KT. ANALYSIS OF MODEL SOUNDINGS FOR CLE SUGGESTS MID LEVEL LAPSE RATES NEAR 7C/KM WITH MID LEVEL DRYING PRESENT SUGGESTS THAT STORMS THAT DO DEVELOP IN WNWLY FLOW ALOFT HAVE THE POTENTIAL FOR DAMAGING WINDS AND HAIL THAT CAN TRACK/REDEVELOP ESEWD ACROSS PA/SRN NY STATE INTO NJ TONIGHT. GIVEN THE VERTICAL PROFILES ARE FAVORABLE FOR ISOLATED SUPERCELLS /0-3KM HELICITY NEAR 300 M2/S2/...AN ISOLATED TORNADO IS POSSIBLE NEAR/JUST N OF THE BOUNDARY. ...SRN WI SWWD INTO THE GREAT PLAINS... AIR MASS IS VERY WARM...MOIST AND MODERATELY UNSTABLE AT THIS TIME ALONG AND AHEAD OF FRONTAL BOUNDARY. MLCAPE IS CURRENTLY 1500-2500 J/KG FROM CENTRAL KS ENEWD INTO S CENTRAL IA. MODELS ENHANCE UVVS ACROSS MUCH OF THE CENTRAL PLAINS IN THE VICINITY OF THE BOUNDARY S OF UPPER LEVEL JET STREAK OF 80-100 KT. MODELS DO DEVELOP NOCTURNAL LOW LEVEL JET OF 40 KT FROM SWRN OK INTO SERN KS WHICH WILL ENHANCE LOW LEVEL ASCENT NEAR THE BOUNDARY. SO...MODELS MAY HAVE A GOOD HANDLE ON DEVELOPING SCATTERED STRONG /SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. LOOK FOR ACTIVITY TO CONTINUE FROM NRN IL SWWD INTO NERN MO...BUT FOR MORE DEVELOPMENT IN VICINITY OF OLD CONVECTIVE BOUNDARIES FROM NWRN IL INTO KS DEVELOPING INTO AN MCS OVERNIGHT. POTENTIAL INSTABILITY WITH SBCAPE FORECAST BETWEEN 3000-4000 J/KG IS EXPECTED BY TONIGHT AND STEEP MID LEVEL LAPSE RATES BETWEEN 7-7.5C/KM INDICATES DAMAGING WINDS AND HAIL BEING THE MAIN THREATS. ...CENTRAL INTERMOUNTAIN REGION... NAM/RUC MID LEVEL TEMPERATURES ARE FORECAST TO CHANGE LITTLE LATER TODAY WITH VALUES BEING AROUND -16C IN ASSOCIATION WITH MID/UPPER LEVEL LOW MOVING SSEWD FROM CENTRAL ID INTO NERN NV/NWRN UT/S CENTRAL ID BY THE END OF THE PERIOD. RUC MODEL IS MORE UNSTABLE THAN THE NAM AND ANALYSIS OF THE FORECAST SOUNDING DO INDICATE A MUCH DRIER BOUNDARY LAYER ON THE NAM THAN COMPARED TO THE RUC. THUS...EXPECT SOME STORMS TO DEVELOP BY THIS EVENING POSSIBLY PRODUCING SOME STRONG WINDS ACROSS PARTS OF NRN UT GIVEN THAT VERTICAL PROFILES INDICATE AN INVERTED-V ASPECT. ..MCCARTHY.. 08/25/2006  From swody1 at goshenarc.org Fri Aug 25 20:03:05 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 16:03:05 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 252002 SWODY1 SPC AC 252000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT FRI AUG 25 2006 VALID 252000Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL/SRN HIGH PLAINS TO GREAT LAKES/NRN OH VALLEY...AND THEN SEWD TO THE MID ATLANTIC COAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN UT...NWRN CO AND SWRN WY... ...UPPER MIDWEST/SRN GREAT LAKES TO MID ATLANTIC COAST... LATEST MESOANALYSIS INDICATED A SURFACE LOW OVER NERN IA/SWRN WI WITH AN ATTENDANT WARM OR QUASI-STATIONARY BOUNDARY EXTENDING EWD THROUGH CNTRL LOWER MI AND THEN MORE ESEWD FROM NEAR BUF TO CNTRL NJ. A COLD FRONT THEN STRETCHED SWWD FROM THIS LOW THROUGH S-CNTRL IA. BREAKS IN THE CLOUDS FROM SERN WI/NRN IL INTO ERN IA HAVE ALLOWED BOUNDARY LAYER TO WARM TO 75-85 F AND WHEN COUPLED WITH DEW POINTS IN THE UPPER 60S TO LOWER 70S...AIR MASS HAS BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-2000 J/KG. CONVERGENCE ALONG THESE BOUNDARIES IN CONJUNCTION WITH INFLUENCE OF WEAKENING SHORT WAVE TROUGH OVER NRN/CNTRL WI INTO NRN LOWER MI HAVE CONTRIBUTED TO INCREASING STORM COVERAGE AND INTENSITY OVER SRN WI/NRN IL. LOCAL VADS INDICATE MODEST VERTICAL SHEAR OF 30-35 KTS WHICH IS SUFFICIENT TO SUPPORT ORGANIZED UPDRAFTS GIVEN THE MODERATE INSTABILITY. SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY SEVERE WEATHER THREATS WITH THESE STORMS. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1883. ADDITIONAL STORMS WILL BE POSSIBLE FARTHER TO THE E OVER CNTRL/SRN LOWER MI...EVENTUALLY INTO THE UPPER OH VALLEY LATER THIS AFTERNOON INTO TONIGHT AS AFOREMENTIONED SHORT WAVE TROUGH CONTINUES EWD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS HAS LIMITED AIR MASS DESTABILIZATION THUS FAR TODAY...AND THIS MAY CONTINUE TO BE A FACTOR WHICH LIMITS OVERALL SEVERE THREAT. HOWEVER...SHOULD STORMS DEVELOP AND BECOME SUSTAINED...SUFFICIENT VERTICAL SHEAR WILL EXIST FOR A FEW SEVERE STORMS CAPABLE OF HIGH WINDS AND SOME HAIL. FARTHER SE OVER ERN PA/NJ...REGION APPEARS TO BE IN SOME DEGREE OF LARGE SCALE SUBSIDENCE IN WAKE OF SHORT WAVE TROUGH WHICH PASSED THROUGH EARLIER TODAY. ABUNDANT SUNSHINE MAY STILL ALLOW FOR THE RE-DEVELOPMENT OF STORMS LATE THIS AFTERNOON OR EVENING ALONG PRE-EXISTING LOW-LEVEL BOUNDARY. SHOULD STORMS DEVELOP...DEEP NWLY FLOW WILL SUPPORT SOME DAMAGING WIND POTENTIAL WITH THE MORE ORGANIZED CELLS. ...CNTRL/SRN HIGH PLAINS TO LOWER MO VALLEY... TRAILING PORTION OF COLD FRONT EXTENDED SWWD THROUGH NWRN MO TO SECONDARY LOW PRESSURE OVER S-CNTRL KS AND WSWWD INTO NERN NM AS OF 19Z. RELATIVELY CLOUD FREE SKIES S OF THIS BOUNDARY HAVE ALLOWED FOR STRONG DIABATIC HEATING WITHIN MOIST BOUNDARY LAYER WHERE MLCAPES HAVE INCREASED TO 2000-3000 J/KG WITH A RAPIDLY WEAKENING CAP. THIS DESTABILIZATION COUPLED WITH INCREASED FORCING FOR ASCENT ASSOCIATED WITH SHORT WAVE TROUGH SHIFTING EWD OUT OF ERN CO SHOULD SUPPORT AN INCREASE IN TSTM COVERAGE ALONG FRONT LATE THIS AFTERNOON INTO EVENING. PROFILER/VAD OBSERVATIONS INDICATE VERTICAL SHEAR SUPPORTIVE OF SUPERCELLS OVER SERN CO/SWRN KS...WITH A GENERAL DECREASE WITH NEWD EXTENT ACROSS KS INTO MO. THE STRONGEST STORMS WILL BE CAPABLE OF LARGE HAIL GIVEN THE STEEP MID-LEVEL LAPSE RATES AND ROTATIONAL UPDRAFT POTENTIAL...AS WELL AS LOCALLY DAMAGING WIND GUSTS. THE SEVERE THREAT SHOULD DIMINISH BY LATE EVENING AS BOUNDARY LAYER COOLS AND STABILIZES. ...UT/SRN WY/WRN CO... VISIBLE SATELLITE IMAGERY AND RADAR DATA INDICATE TSTMS DEVELOPING ALONG THE ERN SLOPES OF THE WASATCH THIS AFTERNOON IN RESPONSE TO APPROACH OF SHORT WAVE TROUGH THROUGH ERN NV INTO WRN UT. WHILE BOUNDARY LAYER IS NOT PARTICULARLY WARM OR MOIST...THE PRESENCE OF STEEP LOW TO MID LEVEL LAPSE RATES ARE CONTRIBUTING TO MODERATE INSTABILITY WITH MLCAPES OF 500-1500 J/KG. INCREASING MID AND HIGH-LEVEL WIND FIELDS IN ASSOCIATION WITH APPROACHING IMPULSE ARE RESULTING IN SUFFICIENT VERTICAL SHEAR FOR SOME STORM ORGANIZATION/ROTATION. ISOLATED SEVERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE GREATEST THREATS WITH THESE MORE INTENSE STORMS. ..MEAD.. 08/25/2006  From swody1 at goshenarc.org Sat Aug 26 01:08:30 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Fri, 25 Aug 2006 21:08:30 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260108 SWODY1 SPC AC 260106 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0806 PM CDT FRI AUG 25 2006 VALID 260100Z - 261200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SCNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN UT AND NWRN CO... ...THERE IS A SLGT RISK OF SVR TSTMS OVER SWRN NY AND NWRN PA... ...SCNTRL PLAINS... QUASI-STATIONARY FRONTAL ZONE BISECTS THE SCNTRL PLAINS FROM THE TX PNHDL NEWD ACROSS KS...TO NRN MO. WIDESPREAD DEEP CONVECTION HAS DEVELOPED IN VARIOUS REGIMES ACROSS THIS REGION...FROM HOT AND DEEPLY MIXED BOUNDARY LAYER AIR MASS AHEAD OF THE FRONT...OVER NRN OK/SRN KS...TO STRONGLY UNSTABLE POST-FRONTAL AIR MASS...ALONG THE NEB/KS BORDER. MOST INTENSE AND LONG-LIVED STORMS HAVE BEEN ON OR NEAR THE FRONTAL WIND SHIFT FROM SWRN KS TO NWRN MO. LARGE SCALE MID/UPPER LEVEL DIFFLUENCE ATOP ABUNDANTLY MOIST/UNSTABLE AIR MASS ACROSS THE BOUNDARY SHOULD SUSTAIN VIGOROUS STORMS WITH HAIL AND HIGH WINDS WELL INTO THE NIGHT. GENERALLY WEAK LOW LEVEL FLOW TOPPED BY 30KT MID LEVEL FLOW WAS RESULTING IN SUFFICIENT BULK SHEAR FOR UPDRAFT PERSISTENCE AND ROTATION. MAGNITUDE OF LOW LEVEL CAPE AND ENHANCED SHEAR NEAR AND NORTH OF THE SURFACE FRONT/WIND SHIFT COULD SUPPORT A BRIEF TORNADO OR TWO FROM CELLS TRACKING NEAR/ALONG THE FRONT. ...ERN UT/NWRN CO... UPPER TROUGH OVER THE NRN GREAT BASIN WILL CONTINUE TO DIG SEWD TONIGHT AND INDUCE WIDESPREAD ASCENT ACROSS THE NCNTRL ROCKIES. NUMEROUS HIGH-BASED STORMS IN LOW-CAPE BUT MODESTLY SHEARED ENVIRONMENT WILL CONTINUE TO POSE A THREAT OF MARGINALLY SEVERE HAIL AND DAMAGING DOWNBURSTS. THIS ACTIVITY WILL GRADUALLY WANE THROUGH LATE EVENING AS LOW LEVELS STABILIZE AND BOUNDARY LAYER LAPSE RATES WEAKEN. ...WRN NY/NWRN PA... TSTMS HAVE RECENTLY INCREASED AHEAD OF LOW-AMPLITUDE SHORT WAVE IMPULSE TRACKING SEWD ACROSS LAKES ERIE/ONTARIO. THIS IMPULSE WAS LIKELY AIDING DEEP LAYER ASCENT AND DESTABILIZATION IN A NARROW ZONE FROM NWRN PA INTO WRN NY WHERE DIAGNOSTIC DATA AND EVENING SOUNDINGS SUGGEST STRONG DEEP LAYER SHEAR EXISTS. SOUNDINGS ALSO DEPICT RELATIVELY WEAK MID LEVEL LAPSE RATES BUT MAY NOT BE TRULY SAMPLING THE SMALL SCALE ENVIRONMENT BETWEEN PIT AND BUF WHERE CONVECTION IS EXPECTED TO PERSIST. GIVEN LATEST TRENDS IN REFLECTIVITY...AND MODEL GUIDANCE SUGGESTING AN INCREASE IN CONVECTION ACROSS THE NY/PA BORDER THROUGH LATE TONIGHT...A SMALL SLGT RISK WILL BE MAINTAINED. MARGINALLY SEVERE HAIL APPEARS TO BE THE PRIMARY HAZARD AT THIS TIME BUT A BRIEF SEVERE WIND GUST OR TORNADO COULD OCCUR IF A ROBUST CELL CAN TRACK PREFERENTIALLY ALONG THE SURFACE BOUNDARY SITUATED ACROSS NWRN PA/WRN NY. ...UPPER MIDWEST... DESPITE STRONG INSTABILITY AND FOCUSED LOW LEVEL FORCING ALONG THE FRONT...AND NEAR WEAK FRONTAL WAVE OVER ERN IA/NRN IL...TSTMS ACROSS THESE AREAS HAVE REMAINED POORLY ORGANIZED SINCE EARLY EVENING. WEAK LARGE SCALE SUPPORT /SHORT WAVE RIDGING ALOFT/ AND SLOW DIURNAL DECREASE IN INSTABILITY SHOULD INHIBIT A MORE WIDESPREAD SEVERE THREAT. AN ISOLATED HAIL AND/OR WIND EVENT REMAINS POSSIBLE GIVEN FRONTAL LIFT OCCURRING IN MOIST AND UNSTABLE ENVIRONMENT. HOWEVER... OVERALL PROBABILITY DOES NOT WARRANT CONTINUING A SLGT RISK IN THIS AREA. ..CARBIN.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 05:51:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 01:51:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 260551 SWODY1 SPC AC 260550 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CDT SAT AUG 26 2006 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GREAT BASIN/CNTRL ROCKIES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE MIDWEST AND PARTS OF THE ERN GREAT LAKES TO DELMARVA... ...SYNOPSIS... COMPLEX SYNOPTIC FLOW REGIME WILL EVOLVE ACROSS THE CONUS THIS PERIOD WITH A NUMBER OF DIFFERENT STREAMS COMPOSED OF RELATIVELY HIGH-AMPLITUDE MID/UPPER LEVEL WAVES. WITHIN THIS FLOW WILL ALSO EXIST A NUMBER OF SMALLER-SCALE PERTURBATIONS EMANATING FROM EPISODES OF WIDESPREAD DEEP CONVECTION. PRIMARY LARGE SCALE FEATURES DRIVING DEEP CONVECTION WILL INCLUDE MID/UPPER LOW DEVELOPING ACROSS THE ERN GREAT BASIN...A QUASI-STATIONARY FRONT FROM THE SRN HIGH PLAINS NEWD TO THE MIDWEST/LOWER MI...AND A BACK DOOR FRONT FROM PA INTO DELMARVA AREA. ...ERN GREAT BASIN TO CNTRL ROCKIES... A MIDDLE STREAM UPPER LOW WILL CONTINUE TO TRANSLATE EAST FROM THE GREAT BASIN TO THE ROCKIES TODAY. MODEST HEIGHT FALLS...MID LEVEL COLD POOL...AND BAND OF 30-40KT DIFFLUENT MID LEVEL FLOW WILL SPREAD EAST FROM UT TO WY/CO THIS AFTERNOON. TSTMS SHOULD INCREASE AS THE SYSTEM MOVES ACROSS UT THROUGH THE AFTERNOON. SIMILAR TO FRIDAY....STEEP LAPSE RATES AND MOISTENING DUE TO STRONG DPVA WILL SUPPORT MODEST INSTABILITY WITHIN SUFFICIENTLY SHEARED ENVIRONMENT FOR PERSISTENT/ORGANIZED STORMS. SUPERCELLS APPEAR LIKELY AND WILL BE CAPABLE OF PRODUCING HAIL AND HIGH WINDS. ...SRN PLAINS TO MIDWEST... FROM THE HIGH PLAINS TO THE MID WEST...STALLED SYNOPTIC BOUNDARY WILL BE INTERSPERSED WITH NUMEROUS CONVECTIVE OUTFLOWS FROM CO/NM ENEWD ACROSS KS/OK...AND NEWD TO IL. MCS NOW MOVING ACROSS MO WILL LIKELY INDUCE AN MCV IMPULSE THAT MAY TRACK DOWNSTREAM AND ACROSS THE MS VALLEY TO THE MIDWEST THROUGH THE DAY. LIFT ASSOCIATED WITH THIS IMPULSE WILL ACT ON INCREASINGLY UNSTABLE AIR MASS FROM IL TO IND. ON THE LARGE SCALE...SHEAR REMAINS WEAK ACROSS THESE AREAS. HOWEVER...FORCING WITH THE MCV AND MAGNITUDE OF INSTABILITY SHOULD PROVOKE A FEW SEVERE STORMS WITH HAIL AND HIGH WINDS. IN THE WAKE OF THIS SYSTEM...CLEARING CONVECTIVE DEBRIS ACROSS WRN MO/KS AND OK...WILL AGAIN RESULT IN STRONG INSTABILITY ACROSS THESE AREAS. FRONTAL BOUNDARY AND OUTFLOWS WILL PROVIDE A FOCUS FOR AFTERNOON AND EVENING TSTMS. BELT OF 30-40KT MID LEVEL FLOW WILL PROVIDE ADEQUATE EFFECTIVE SHEAR ACROSS THE REGION FOR A FEW SUPERCELLS AND ORGANIZED STORM CLUSTERS WITH DAMAGING WINDS AND HAIL. ACTIVITY MAY MERGE AND GROW UPSCALE INTO A SLOW MOVING MCS OR TWO THROUGH SUNDAY MORNING. ...LOWER MI... IN THE NRN STREAM...TROUGH CROSSING SCNTRL CANADA WILL BRUSH PARTS OF THE UPPER MS VALLEY AND NRN GREAT LAKES. WHILE STRONGER HEIGHT FALLS WITH THIS SYSTEM WILL REMAIN PRIMARILY NORTH OF THE BORDER...A BAND OF SLIGHTLY STRONGER MID LEVEL WLY FLOW WILL DEVELOP EWD ACROSS LOWER MI...COINCIDENT WITH DIURNAL HEATING AND FRONTAL PASSAGE OVER THIS AREA. A FEW SEVERE STORMS WITH HAIL AND WIND APPEAR POSSIBLE ACROSS THIS AREA DURING THE AFTERNOON/EARLY EVENING. ...LAKE ERIE TO DELMARVA... NW-SE ORIENTED FRONTAL BAND WILL CONTINUE TO SEPARATE CONTINENTAL POLAR AIR MASS OVER NEW ENGLAND FROM RETURNING TROPICAL MARITIME AIR ACROSS THE OH VALLEY. LOW AMPLITUDE PERTURBATIONS IN NW FLOW ALOFT WILL ENHANCE ASCENT ALONG THE LOW LEVEL BOUNDARY AND LEAD TO SCATTERED TSTM DEVELOPMENT DURING THE DAY. PART OF THE BOUNDARY MAY SETTLE FARTHER SWWD INTO INCREASINGLY UNSTABLE AIR ACROSS SRN PA/WV PNHDL AND DELMARVA AREAS THROUGH THE EVENING. DIRECTIONAL SHEAR ALONG THE BOUNDARY...AS WELL AS DEEP LAYER VERTICAL SPEED SHEAR...WILL ENHANCE STORM UPDRAFTS WITH A FEW HAIL/WIND EVENTS POSSIBLE. ..CARBIN.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 12:35:10 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 08:35:10 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261235 SWODY1 SPC AC 261233 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0733 AM CDT SAT AUG 26 2006 VALID 261300Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR NE IL...NW INDIANA...AND SRN LOWER MI... ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE TX PANHANDLE...NRN OK...SE KS...NW AR...AND SW MO... ...THERE IS A SLGT RISK OF SVR TSTMS FOR NE UT...WRN CO...SW WY... ...SYNOPSIS... A MID LEVEL TROUGH OVER THE GREAT BASIN...WITHIN A SRN STREAM OF THE WLYS...WILL MOVE SLOWLY ESEWD OVER UT TO WRN CO BY THE END OF THE PERIOD. A SEPARATE WAVE IN THE NRN STREAM WILL PROGRESS EWD FROM MANITOBA/WRN ONTARIO TOWARD WRN QUEBEC. IN ASSOCIATION WITH THESE FLOW STREAMS...A LOW-LEVEL BAROCLINIC ZONE EXTENDS WNWWD FROM THE NRN MID ATLANTIC REGION TO SRN LOWER MI...AND THEN SWWD ACROSS NRN MO/NW OK TO ERN NM. ONLY SLOW SEWD MOTION OF THIS FRONT IS EXPECTED ACROSS THE PLAINS/MS VALLEY IN THE WAKE OF THE NRN STREAM TROUGH...AND THE MID ATLANTIC PORTION OF THE BOUNDARY SHOULD REMAIN QUASI-STATIONARY. ...IL TO SRN LOWER MI... A LARGE CLUSTER OF THUNDERSTORMS OVER MO/WRN IL HAS PRODUCED AN MCV OVER NE MO WHICH SHOULD MOVE ENEWD OVER IL TODAY AND INDIANA/OH TONIGHT. BOUNDARY LAYER DEWPOINTS OF 68-72 F WILL SPREAD NEWD IN ADVANCE OF A WEAK WAVE ON THE SURFACE FRONT ACROSS NRN IL...PROVIDING SUFFICIENT INSTABILITY TO MAINTAIN THUNDERSTORM CLUSTERS THROUGH TONIGHT ALONG THE PATH OF THE MCV. MODEST VERTICAL SHEAR ASSOCIATED WITH MCV AND NEAR THE SURFACE FRONT ACROSS LOWER MI MAY SUPPORT A FEW SEVERE STORMS/MARGINAL SUPERCELLS TODAY. DAMAGING WINDS SHOULD BE THE MAIN SEVERE THREAT...ALONG WITH MARGINALLY SEVERE HAIL. ...SRN PLAINS... WIDESPREAD OVERNIGHT AND ONGOING CONVECTION HAS REDUCED MID LEVEL LAPSE RATES OVER A BROAD AREA IMMEDIATELY N OF THE FRONT ACROSS KS/MO...WITH THE STEEPER LOW-MID LEVEL LAPSE RATES CONFINED TO A BAND ALONG AND S OF THE FRONT WHERE STRONG SURFACE HEATING AND DEEP MIXING HAS OCCURRED THE PAST TWO DAYS. A FEW STRONG/SEVERE STORMS SHOULD FORM ALONG THE FRONT AND REMNANT OUTFLOW BOUNDARIES THIS AFTERNOON...NEAR THE SRN FRINGE OF THE ONGOING CONVECTION THIS MORNING. THESE STORMS WILL BE CAPABLE OF PRODUCING ISOLATED DAMAGING DOWNBURST WINDS AND MARGINALLY SEVERE HAIL. OVERALL...THE SEVERE STORM THREAT APPEARS MARGINAL AND IS REDUCED COMPARED TO FRIDAY. ...UT/CO AREA... A BELT OF ASCENT WILL CONTINUE TO SUPPORT SCATTERED THUNDERSTORM DEVELOPMENT TODAY OVER NRN/ERN UT INTO WRN CO AND SW WY...IN ADVANCE OF A MID LEVEL TROUGH MOVING ESEWD FROM SW ID/NE NV. STEEP LOW-MID LEVEL LAPSE RATES AND 500 MB TEMPERATURES APPROACHING -15 C WILL SUPPORT A FEW STORMS WITH MARGINALLY SEVERE HAIL TODAY ACROSS NRN UT. THE STRONGER VERTICAL SHEAR AND POTENTIAL FOR MORE ORGANIZED STORM TYPES IS EXPECTED THIS AFTERNOON OVER NERN UT INTO WRN CO. HERE...THE STRONGER STORMS MAY PRODUCE ISOLATED LARGE HAIL AND STRONG OUTFLOW WINDS. ...MID ATLANTIC AREA... CONVECTION AND AN ASSOCIATED MID LEVEL WAVE WILL MOVE OFFSHORE EARLY THIS MORNING. SHORTWAVE RIDGING IS EXPECTED THROUGH MUCH OF THE PERIOD OVER THIS AREA...WITH ONLY SPARSE THUNDERSTORM COVERAGE ANTICIPATED NEAR THE NW-SE ORIENTED SURFACE FRONT. VERY ISOLATED STRONG WIND GUSTS OR HAIL CANNOT BE RULED OUT...BUT THE OVERALL THREAT APPEARS INSUFFICIENT TO WARRANT A SLIGHT RISK. ..THOMPSON/TAYLOR.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 16:40:29 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 12:40:29 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261639 SWODY1 SPC AC 261637 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CDT SAT AUG 26 2006 VALID 261630Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVENING ACROSS LOWER MI INTO NERN IL AND NRN IN.... ...THERE IS A SLGT RISK OF SVR TSTMS THRU TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY TONIGHT ACROSS PARTS OF THE CENTRAL ROCKIES.... ...SYNOPSIS... MID/UPPER LEVEL LOW MOVG SEWD INTO THE CENTRAL INTERMOUNTAIN REGION WILL TURN EWD LATER TODAY AND TONIGHT INTO WY/CO. MID/UPPER LEVEL SHORTWAVE TROUGH WILL BE SKIRTING EWD ACROSS ONTARIO AND THE NRN GREAT LAKES AS MID/UPPER LEVEL RIDGING REMAINS OVER THE SERN QUARTER OF THE U.S. MORNING SURFACE ANALYSIS SHOWS WEAKENING LOW PRESSURE OVER SERN WI WITH A COLD FRONT EXTENDING SWWD INTO NWRN MO...THEN BECOMING QUASI-STATIONARY ACROSS NERN KS INTO THE TX PANHANDLE. SEVERAL OLD CONVECTIVE BOUNDARIES ARE DRAPED ACROSS CENTRAL AR...THRU CENTRAL OK INTO W CENTRAL TX. ALSO...A WARM FRONT REMAINS FROM THE WI LOW EWD THRU CENTRAL LOWER MI...THEN IS MORE QUASI-STATIONARY SEWD THRU NWRN PA AND SRN NJ. ...LOWER MI SSWWD INTO PARTS OF IL AND IN... SFC LOW OVER SERN WI IS FORECAST TO MOVE NEWD INTO NWRN LOWER MI THRU LATE THIS AFTERNOON DRAGGING ASSOCIATED COLD FRONT THRU NERN IL INTO CENTRAL MO. STRONG THUNDERSTORMS ARE CURRENTLY MOVING ACROSS NWRN SECTIONS OF LOWER MI IN AREA WITH DEEP LAYER SHEAR AT APPROXIMATELY 40 KT. CLOUD COVER IS LIMITING POTENTIAL INSTABILITY AT THIS TIME WITH MLCAPES BETWEEN 500 AND 1000 J/KG. PRESENCE OF SUFFICIENT SHEAR MAY SUPPORT WEAK SUPERCELLS THROUGH THIS REGION INTO EARLY THIS AFTERNOON. THERE MAY BE ENOUGH HEATING/LOW LEVEL WARM ADVECTION LATER OVER E CENTRAL LWR MI THAT MAY ALLOW MORE THERMODYNAMICS THAT MAY AID IN HAIL AND DAMAGING WINDS. ...PARTS OF THE CENTRAL PLAINS... AIR MASS ACROSS THIS AREA REMAINS QUITE WARM AND MOIST AS SURFACE DEW POINTS ARE IN THE UPPER 60S/LOWER 70S. THE PRESENCE OF OLD CONVECTIVE OUTFLOWS FROM THE TX PANHANDLE INTO AR MAY A PLAY ROLE TO ENHANCE LIFT AS DAYTIME HEATING WILL DESTABILIZE THE AIR MASS FOR MLCAPES TO REACH TO 1500-2000 J/KG. THE HEATING WILL ALSO STEEPEN LOW-MID LEVEL LAPSE RATES ACROSS THIS REGION TO BETWEEN 7.0 TO 9.0C/KM. THUS...WIDELY SCATTERED STRONG/SEVERE THUNDERSTORMS ARE EXPECTED WITH THE MAIN THREAT BEING STRONG DOWNBURSTS POSSIBLY ACCOMPANIED BY SOME HAIL. ...INTERMOUNTAIN REGION... MID/UPPER LEVEL LOW WITH MID LEVEL TEMPERATURES AROUND -14 TO -16C WILL TRANSLATE ESEWD ACROSS UT INTO WY/CO DURING THE PERIOD. MOST NOTABLE IN THE ANALYSIS OF THE LATEST RUC SOUNDINGS IS THE MID LEVEL DRYING THAT WILL ACCOMPANY THE LOW. STEEP MID LEVEL LAPSE RATES OF 7-8C/KM WILL BE ACROSS PARTS OF ERN UT INTO WRN CO SUFFICIENT TO SUPPORT HAIL AND DAMAGING WINDS WITH THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY TONIGHT. ..MCCARTHY/GRAMS.. 08/26/2006  From swody1 at goshenarc.org Sat Aug 26 19:54:14 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 15:54:14 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 261954 SWODY1 SPC AC 261952 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0252 PM CDT SAT AUG 26 2006 VALID 262000Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE GREAT LAKES AND OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL AND SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE INTERMOUNTAIN WEST... ...GREAT LAKES INTO OH VALLEY... FORCING FOR UPWARD VERTICAL MOTION IS BEING ENHANCED THIS AFTERNOON BY: 1) SHORT WAVE TROUGH AND ASSOCIATED SPEED MAX OVER THE U.P. AND LAKE MI...AND 2) MCV OVER NRN/CNTRL IL. WHILE CONSIDERABLE CLOUDS HAVE LIMITED DIABATIC HEATING AND RESULTANT DESTABILIZATION...MOIST BOUNDARY LAYER CONDITIONS ARE CONTRIBUTING TO MLCAPES OF 500-1000 J/KG FROM LOWER MI INTO IL/IND. THE STRONGEST STORMS THUS FAR TODAY HAVE BEEN LOCATED OVER PARTS OF LOWER MI INVOF SURFACE LOW MOVING INTO THE W-CNTRL PART OF THE STATE. MESOANALYSIS INDICATES THAT ATTENDANT WARM FRONT EXTENDS FROM THIS LOW EWD TO N OF RBQ AND THEN SEWD TO NEAR MTC. SHEAR PROFILES ALONG THIS BOUNDARY ARE SUPPORTIVE OF SUPERCELLS OWING TO PRONOUNCED LOW-LEVEL HODOGRAPH CURVATURE AND AROUND 35 KTS OF EFFECTIVE BULK SHEAR. FURTHER AIR MASS DESTABILIZATION AND APPROACH OF IMPULSES FROM THE NW AND SW SHOULD CONTRIBUTE TO INCREASED COVERAGE AND INTENSITY OF STORMS OVER LOWER MI THIS AFTERNOON INTO EVENING WITH THE MAIN THREAT BEING SEVERE HAIL AND LOCALLY DAMAGING WINDS. GREATEST POTENTIAL FOR A TORNADO OR TWO WILL BE WITH ANY SURFACE-BASED SUPERCELLS THAT CAN FAVORABLY INTERACT WITH SURFACE WARM FRONT. ADDITIONAL STRONG TO POTENTIALLY SEVERE STORMS WILL BE POSSIBLE SWWD ALONG TRAILING COLD FRONT INTO PORTIONS OF NRN IL...AS WELL AS AHEAD OF MCV INTO IND/OH WHERE STRONGER DESTABILIZATION IS OCCURRING. VERTICAL SHEAR REMAINS COMPARATIVELY WEAKER THAN POINTS TO THE N...WITH THE MAIN THREATS BEING MARGINALLY SEVERE HAIL AND LOCALLY STRONG WIND GUSTS WITH ORGANIZED MULTICELL CLUSTERS. ...SERN KS/OK INTO THE TX PNHDL/NWRN TX... VISIBLE SATELLITE AND MESOANALYSIS INDICATE THAT OUTFLOW FROM NOCTURNAL CONVECTION HAS ESTABLISHED A BOUNDARY WELL S OF PRIMARY SYNOPTIC FRONT FROM CNTRL AR WWD TO CNTRL OK AND THEN SWWD TO NEAR ABI. THE MAIN COLD FRONT EXTENDED FROM NEAR CNU TO NEAR PVW AS OF 18Z. WHILE 12Z REGIONAL SOUNDINGS INDICATED THAT MID-LEVEL LAPSE RATES WERE RELATIVELY POOR /AROUND 6.5 C/KM/...DAYTIME HEATING AND DEWPOINTS OF 65-70 F ARE CONTRIBUTING TO DESTABILIZATION OF PRE-FRONTAL AIR MASS WITH MLCAPES LIKELY REACHING 2000-3000 J/KG LATER THIS AFTERNOON. WHILE LARGE-SCALE FORCING FOR ASCENT IS EXPECTED TO REMAIN RATHER WEAK...CONVERGENCE ALONG THE LOW-LEVEL BOUNDARIES SHOULD SUPPORT AN INCREASE IN STORM COVERAGE AND INTENSITY BOTH ALONG THE OUTFLOW BOUNDARY AND MAIN FRONT. AREA VWPS AND PROFILERS INDICATE THAT VERTICAL SHEAR IS MARGINAL FOR STORM ORGANIZATION...WITH MULTICELL CLUSTERS THE MOST LIKELY CONVECTIVE MODE. THE STRONGEST STORMS WILL BE CAPABLE OF SEVERE HAIL AND DAMAGING WIND GUSTS. ...INTERMOUNTAIN WEST... AFTERNOON WATER VAPOR IMAGERY INDICATES MID/UPPER LOW MOVING SEWD INTO NRN UT WITH STRONGEST HEIGHT FALLS SHIFTING ACROSS ERN UT INTO WRN CO. TSTMS ARE RAPIDLY INCREASING IN COVERAGE THIS AFTERNOON WITHIN THIS ZONE OF HEIGHT FALLS WHERE STEEP LAPSE RATES ARE CONTRIBUTING TO MLCAPES OF 500-1000 J/KG. GJT VWP INDICATES RELATIVELY STRONG FLOW ABOVE THE BOUNDARY LAYER /I.E. 35 KT WLY WINDS AT 2 KM AGL INCREASING TO 60 KTS OUT OF THE SW AT 6 KM AGL/ WITH VERTICAL SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS CAPABLE OF DAMAGING WINDS AND LARGE HAIL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1891. ..MEAD.. 08/26/2006  From swody1 at goshenarc.org Sun Aug 27 01:02:24 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sat, 26 Aug 2006 21:02:24 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270102 SWODY1 SPC AC 270100 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SAT AUG 26 2006 VALID 270100Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL AND SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE OH VALLEY AND GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTION OF SERN CO... ...NWRN TX THROUGH CNTRL OK AND SERN KS... NUMEROUS STORMS CONTINUE DEVELOPING IN VICINITY OF COLD FRONT AND CONVECTIVE OUTFLOW BOUNDARIES FROM NWRN TX NEWD THROUGH OK INTO SERN KS. THE 00Z RAOB FROM NORMAN SHOWS THE ATMOSPHERE REMAINS MODERATELY UNSTABLE IN THIS REGION...AND BOUNDARY LAYER TEMPERATURE/DEWPOINT SPREADS ARE FAVORABLE FOR ISOLATED DAMAGING WIND GUSTS. SOME HAIL MAY ALSO ACCOMPANY THE STRONGER STORMS. ACTIVITY IS MOSTLY MULTICELL IN CHARACTER. HOWEVER...AN ELEVATED LEFT MOVING SUPERCELL WAS OBSERVED MOVING THROUGH NRN OK N OF THE FRONT DURING THE PAST HOUR WHERE SLIGHTLY STRONGER MID LEVEL FLOW IS CONTRIBUTING TO BULK EFFECTIVE SHEAR AROUND 35 KT. AS THE BOUNDARY LAYER DECOUPLES TONIGHT...WARM SECTOR LOW LEVEL FLOW IS FORECAST TO INCREASE TO SLY AT 20-25 KT. THIS SHOULD ENHANCE LIFT AND SUPPORT CONTINUED DEVELOPMENT ALONG AND N OF THE FRONT/OUTFLOW BOUNDARY. THIS SEVERE THREAT MAY PERSIST FOR ANOTHER FEW HOURS. ...GREAT LAKES...OH VALLEY THROUGH MID ATLANTIC... SCATTERED STORMS CONTINUE DEVELOPING WITHIN ZONE OF ASCENT ACCOMPANYING SHORTWAVE TROUGH MOVING EWD THROUGH ERN IL INTO IND. LATEST VWP DATA SHOW THE SLY LOW LEVEL JET HAS INCREASED TO 40 KT IN ADVANCE OF THIS FEATURE WITH FAVORABLE LOW LEVEL HODOGRAPHS FOR SUPERCELLS WITH LOW LEVEL MESOCYCLONES. UPDRAFT ROTATION HAS RECENTLY BEEN OBSERVED IN A FEW OF THE STORMS. THREAT WILL EXIST FOR AN ISOLATED BRIEF TORNADO OR TWO WITH ANY SUSTAINED SUPERCELL NEXT FEW HOURS. PRIMARY LIMITING FACTOR IS MARGINAL INSTABILITY AND POOR LAPSE RATES. OTHER STORMS ARE DEVELOPING ACROSS SRN MI. THIS ACTIVITY MAY REMAIN CAPABLE OF PRODUCING ISOLATED DAMAGING WIND GUSTS NEXT COUPLE HOURS. ...CO... STORMS MOVING THROUGH ERN CO MAY REMAIN CAPABLE OF PRODUCING ISOLATED DAMAGING WIND AND LARGE HAIL NEXT COUPLE HOURS. HOWEVER...THIS ACTIVITY IS EXPECTED TO BEGIN A WEAKENING TREND AS IT APPROACHES THE KS BORDER WHERE INSTABILITY IS MORE LIMITED. ..DIAL.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 05:52:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 01:52:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 270553 SWODY1 SPC AC 270551 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1251 AM CDT SUN AUG 27 2006 VALID 271200Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL AND SRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN PARTS OF THE UPPER OH VALLEY INTO THE MID ATLANTIC AND NERN U.S.... ...SYNOPSIS... UPPER PATTERN WILL REMAIN PROGRESSIVE THIS PERIOD. UPPER LOW OVER CO WILL CONTINUE EWD INTO THE CNTRL AND SRN PLAINS. FARTHER EAST...A VORT MAX NOW OVER IND WILL MOVE EWD INTO PA AND THE NERN U.S. DURING THE AFTERNOON. AT THE SURFACE A COLD FRONT WILL ACCOMPANY THE VORT MAX INTO THE MID ATLANTIC AND NERN U.S. DURING THE AFTERNOON. TRAILING PORTION OF THIS BOUNDARY WILL EXTEND SWWD INTO THE LOWER MS VALLEY AND SRN PLAINS. A WARM FRONT CURRENTLY FROM NRN VA INTO SWRN PA MAY LIFT SLOWLY NWD DURING THE DAY. ...CNTRL AND SRN HIGH PLAINS... WEAK ENELY BOUNDARY LAYER FLOW IN POST FRONTAL ENVIRONMENT SHOULD MAINTAIN LOW LEVEL DEWPOINTS IN THE UPPER 50S TO NEAR 60 INTO THE CNTRL AND SRN HIGH PLAINS. MID LEVEL DRY SLOT WILL ADVECT NEWD THROUGH ERN CO IN WAKE OF VORT MAX NOW OVER ERN CO. SECONDARY VORT MAX WILL ROTATE THROUGH THE BASE OF THE EWD ADVANCING UPPER LOW AND INTO PARTS OF THE CNTRL HIGH PLAINS DURING THE DAY. SURFACE HEATING WITHIN DRY SLOT AND COOLING MID LEVEL TEMPERATURES ACCOMPANYING THE UPPER LOW WILL RESULT IN STEEP LAPSE RATES DURING THE AFTERNOON. THE STEEP LAPSE RATES AND IN SITU LOW LEVEL MOISTURE WILL RESULT IN MODERATE INSTABILITY WITH MLCAPE AROUND 1500 J/KG. STORMS ARE EXPECTED TO DEVELOP WITHIN ZONE OF LARGE SCALE ASCENT ACCOMPANYING THE SHORTWAVE TROUGH AS THE BOUNDARY LAYER DESTABILIZES DURING THE AFTERNOON. LOW LEVEL WIND FIELDS WILL REMAIN RATHER WEAK. HOWEVER...A 40 KT MID LEVEL JET ROTATING THROUGH BASE OF UPPER TROUGH WILL CONTRIBUTE TO FAVORABLE DEEP SHEAR FOR SUPERCELL STRUCTURES. LARGE HAIL AND DAMAGING WIND WILL BE THE MAIN THREATS. ...SRN PORTIONS OF THE UPPER OH VALLEY THROUGH PORTIONS OF THE MID ATLANTIC AND NERN STATES... CORRIDOR OF LOW LEVEL DEWPOINTS IN THE UPPER 60S TO NEAR 70 SHOULD PERSIST IN VICINITY OF WARM FRONT AS IT RETREATS SLOWLY NWD. THIS BOUNDARY SHOULD EXTEND FROM NJ WNWWD THROUGH PA SUNDAY AFTERNOON. PRIMARY CONCERN AND POTENTIAL OVERALL LIMITING FACTOR WILL BE DEGREE OF DESTABILIZATION. THUNDERSTORMS WILL LIKELY CONTINUE DEVELOPING INTO EARLY SUNDAY WITHIN ZONE OF ASCENT ACCOMPANYING A VORT MAX CURRENTLY OVER NRN IND. THIS FEATURE SHOULD APPROACH WRN PA BY SUNRISE. OTHER STORMS MAY CONTINUE INTO PARTS OF PA WITHIN ZONE OF WARM ADVECTION N OF THE WARM FRONT. CLOUDS SHOULD REMAIN MORE WIDESPREAD N OF THE FRONT FROM PARTS OF OH AND PA NWD INTO THE NERN STATES. BEST POTENTIAL FOR DESTABILIZATION WILL EXIST NEAR AND S OF THIS BOUNDARY. HOWEVER...WEAK MID LEVEL LAPSE RATES SHOULD LIMIT MLCAPE TO AOB 1000 J/KG. STORMS MAY INTENSIFY ALONG AND N OF WARM FRONT AS WARM SECTOR SOURCE REGION DESTABILIZES. SRN BRANCH OF LOW LEVEL JET IS FORECAST TO STRENGTHEN FROM THE MID ATLANTIC INTO THE NERN STATES IN ASSOCIATION WITH APPROACHING SHORTWAVE TROUGH. THIS WILL RESULT IN LOW LEVEL HODOGRAPHS FAVORABLE FOR A THREAT OF SUPERCELLS WITH LOW LEVEL MESOCYCLONES AND ISOLATED TORNADOES NEAR WARM FRONT. OTHERWISE...THREAT OF ISOLATED DAMAGING WIND WILL EXIST AS STORMS DEVELOP EWD ALONG AND AHEAD OF COLD FRONT. ...NERN TX AND SERN OK THROUGH PORTIONS OF THE LOWER AND MIDDLE MS VALLEY... STORMS ARE EXPECTED TO REDEVELOP DURING THE AFTERNOON ALONG FRONT OR RESIDUAL CONVECTIVE OUTFLOW BOUNDARIES. THE ATMOSPHERE WILL LIKELY ONCE AGAIN BECOME MODERATELY UNSTABLE IN VICINITY OF THESE BOUNDARIES WHERE SURFACE HEATING CAN DEVELOP OUTSIDE OF CONVECTIVE DEBRIS. MODEST VERTICAL SHEAR WILL SUPPORT MAINLY MULTICELLS WITH A THREAT OF ISOLATED DAMAGING WIND. MCV CURRENTLY MOVING ENEWD THROUGH CNTRL OK MAY RESULT IN A GREATER CONCENTRATION OF STORMS OVER PARTS OF AR OR SRN MO DURING THE DAY. AN UPGRADE TO SLIGHT RISK MIGHT BE NEEDED FOR PARTS OF THIS AREA IN LATER OUTLOOKS IF IT BECOMES MORE CERTAIN THAT ONGOING STORMS WILL NOT EXHAUST THE INSTABILITY IN THIS REGION. ..DIAL/TAYLOR.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 12:32:44 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 08:32:44 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271232 SWODY1 SPC AC 271230 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0730 AM CDT SUN AUG 27 2006 VALID 271300Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS SE PA/MD/DE/NJ... ...HIGH PLAINS THIS AFTERNOON... A COLD CORE MID LEVEL LOW OVER NW CO WILL PROGRESS EWD TO NE CO BY THIS AFTERNOON...AND CONTINUE ACROSS NEB/KS INTO TONIGHT. A BAND OF THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON ACROSS ERN CO/NE NM AND SPREAD ESEWD INTO WRN KS AND THE TX PANHANDLE IN ASSOCIATION WITH THIS MID LEVEL WAVE. THOUGH MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP OVER THE HIGH PLAINS...SUFFICIENT INSTABILITY FOR STRONG/SEVERE STORMS IS EXPECTED BY EARLY AFTERNOON. RESIDUAL BOUNDARY LAYER DEWPOINTS OF 55-60 F FROM NE NM/NW TX PANHANDLE INTO ERN CO/WRN KS AND SURFACE HEATING IN THE WAKE OF A CONVECTIVE BAND THIS MORNING SHOULD SUPPORT MLCAPE VALUES OF 500-1000 J/KG. DEEP LAYER WIND FIELDS AND VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...THE STRONGEST OF WHICH WILL BE CAPABLE OF PRODUCING AT LEAST MARGINALLY SEVERE HAIL AND STRONG OUTFLOW WINDS. ...SE PA/NJ AREA TODAY... REMNANT MCV IS MOVING EWD OVER CENTRAL OH THIS MORNING...AND SHOULD CONTINUE ACROSS PA THIS AFTERNOON WHILE INTERACTING WITH A WARM FRONT THAT SHOULD LIFT SLOWLY NWD ACROSS PA/NJ. THE DEGREE OF INSTABILITY ALONG THE BOUNDARY IS IN QUESTION GIVEN THE ONGOING CONVECTION AND RATHER THICK CLOUD COVER FROM SE PA INTO OH. HOWEVER...LOW-LEVEL MOISTURE WILL BE SUFFICIENT FOR EMBEDDED THUNDERSTORMS IN THE ABSENCE OF STRONG SURFACE HEATING. OBSERVED AND FORECAST HODOGRAPHS APPEAR FAVORABLE FOR SUPERCELLS INVOF THE WARM FRONT TODAY...WHERE A FEW STORMS COULD PRODUCE DAMAGING WINDS AND PERHAPS A TORNADO OR TWO. ...OK/AR/MO TODAY... A SURFACE FRONT NEAR I-44 IN MO/OK WILL MOVE LITTLE THIS PERIOD...WITH WEAK WAVE DEVELOPMENT ANTICIPATED ALONG THE FRONT FROM CENTRAL/NE OK INTO SE KS IN ADVANCE OF THE APPROACHING MID LEVEL TROUGH FROM CO. WIDESPREAD CONVECTION FROM SATURDAY EVENING INTO THIS MORNING PRODUCED CONVECTIVE OUTFLOWS THAT NOW EXTEND FROM CENTRAL TX ACROSS SE OK/NW AR INTO SRN MO...AS WELL AS AN MCV THAT IS PROGRESSING NEWD OVER NE OK. THOUGH THE OUTFLOW BOUNDARIES SHOULD BECOME MORE DIFFUSE ACROSS OK/AR/MO AS CONVECTION DIMINISHES THIS MORNING...THE MCV MAY PERSIST AND FOCUS ADDITIONAL THUNDERSTORM DEVELOPMENT DURING THE DAY ACROSS NE OK/SRN MO/NW AR. GRADUAL MOISTENING OF THE LOW-MID LEVELS SUGGEST THAT SURFACE TEMPERATURES AND LOW-LEVEL LAPSE RATES WILL NOT BE AS GREAT AS OBSERVED THE PAST TWO DAYS ACROSS THE OK AREA...THUS THE POTENTIAL FOR DAMAGING DOWNBURSTS SHOULD BECOME RATHER MARGINAL. ..THOMPSON/TAYLOR.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 16:40:18 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 12:40:18 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271640 SWODY1 SPC AC 271638 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1138 AM CDT SUN AUG 27 2006 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF THE DELMARVA.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING ACROSS PARTS OF THE LOWER OHIO VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY TONIGHT ACROSS THE CENTRAL HIGH PLAINS.... ...SYNOPSIS... MID/UPPER LEVEL LOW OVER THE CENTRAL ROCKIES WILL MOVE INTO NEB DURING THE PERIOD. TROUGH ASSOCIATED WITH THIS LOW WILL DRAG EWD THRU THE CENTRAL AND NRN PARTS OF THE SRN PLAINS. LATEST SURFACE ANALYSIS SHOWS A SERIES OF CONVECTIVE BOUNDARIES THAT REACH FROM CENTRAL IND WSWWD ACROSS SRN MO INTO NERN AND S CENTRAL OK INTO W CENTRAL TX. IN ADDITION...THERE IS A QUASI STATIONARY FRONT THAT LIES FROM SRN NJ WWD ACROSS THE MD/WV PANHANDLE INTO CENTRAL OH. LOOKS AT THIS TIME THAT THE STRONGEST ACTIVITY TODAY AND EARLY TONIGHT WILL FOCUS ON THESE AREAS WHERE THERMAL GRADIENTS WILL PROVIDE THE MORE FAVORABLE THERMODYNAMICS FOR STRONG/ISOLATED SEVERE THUNDERSTORMS. ...PARTS OF THE DELMARVA REGION FROM SRN PA/MD AND NRN VA INTO DE... LATEST VISIBLE IMAGERY SHOWS SRN EDGES OF CLOUD COVER FROM DE/MD INTO NRN VA THEN SWWD ACROSS SERN WV. AREAS S OF THIS CLOUD COVER DELINEATION WILL BE LOCATION OF BETTER DAYTIME HEATING/ THERMODYNAMICS. ISOLATED STRONG/SEVERE THUNDERSTORMS ARE POSSIBLE AS THERE WILL BE FAVORABLE SHEAR /STORM RELATIVE HELICITY AROUND 200 M2/S2/ DUE TO LOW LEVEL WARM ADVECTION. LOOKS LIKE STRONG GUSTY WINDS MAY BE THE MAIN THREAT LATER THIS AFTERNOON INTO THIS EVENING. ...PARTS OF THE LOWER OHIO VALLEY... REMNANT OF COLD FRONTAL BOUNDARY EXTENDS FROM LOW OVER SERN ONTARIO SWWD THRU SWRN IND INTO CENTRAL KS. CONSIDERABLE CLOUDINESS COVERS MUCH OF THESE REGION FROM PREVIOUS CONVECTION. THUS...ONCE AGAIN WILL LOOK FOR WHERE THERMAL GRADIENTS MAY SET UP THE BEST FOR AFTN/EVE THUNDERSTORM DEVELOPMENT. BOTH THE NAM AND GFS DEVELOPS CONVECTION ALONG THE SRN FRINGES OF THE CLOUD COVER FROM THE CENTRAL MO/AR BORDER ENEWD INTO N CENTRAL KY. SBCAPE IS FORECAST TO BE BETWEEN 2000-3000 J/KG BY LATER TODAY. THUS...STRONG/ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THESE AREA WITH THE THREAT BEING STRONG GUSTY WINDS AND SOME HAIL. ...CENTRAL HI PLAINS... MID/UPPER LEVEL LOW WILL BE MOVING OUT OF THE CENTRAL ROCKIES BY MID AFTN. WHILE THE AIR MASS LOOKS WORKED OVER ACROSS THE CENTRAL PLAINS FROM CONVECTION OVER THE PAST FEW DAYS...BEST THERMAL GRADIENT EXTENDS FROM SWRN/CENTRAL TX NEWD INTO SERN OK. MID LEVEL COOLING IS EXPECTED TO MOVE ACROSS ERN CO BY MID AFTN AND THIS SHOULD AID IN INITIATING CONVECTIVE DEVELOPMENT WITH DAYTIME HEATING ALONG THE WRN EDGES OF THE EXISTING CLOUD COVER OVER ERN CO. DAYTIME HEATING WITH UPSLOPE COMPONENT TO THE FLOW SHOULD BE SUFFICIENT IN DEVELOPING STRONG/POSSIBLE SEVERE THUNDERSTORMS ACROSS ERN CO THIS AFTN WITH SBCAPE BETWEEN 1000-1500 J/KG. MAIN THREAT AGAIN WILL BE HAIL AND DAMAGING WINDS. MID/UPPER LEVEL FLOW IS EXPECTED TO BE SUFFICIENT FOR DEEP LAYER SHEAR TO 40 KT WHICH WILL BE ENOUGH TO SUPPORT UPDRAFTS/ISOLATED SUPERCELLS. ..MCCARTHY/GRAMS.. 08/27/2006  From swody1 at goshenarc.org Sun Aug 27 19:48:19 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 15:48:19 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 271948 SWODY1 SPC AC 271947 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0247 PM CDT SUN AUG 27 2006 VALID 272000Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY TO THE MIDDLE ATLANTIC COAST... ...CNTRL/SRN HIGH PLAINS... DAYTIME HEATING COUPLED WITH HEIGHT FALLS/DYNAMIC COOLING ASSOCIATED WITH THE APPROACH OF UPPER LOW THROUGH THE CNTRL ROCKIES ARE CONTRIBUTING TO AIR MASS DESTABILIZATION THIS AFTERNOON ACROSS ERN CO INTO WRN KS AND SWD INTO THE OK/TX PNHDLS AND NERN NM. CONTINUED HEATING SHOULD SUPPORT FURTHER DESTABILIZATION THIS AFTERNOON WITH MLCAPES APPROACHING 1000-1500 J/KG. WHILE MORNING RAOB DATA INDICATED 25-30 KT FLOW AT 500 MB ACROSS CO...UPPER TROPOSPHERIC WIND FIELDS WERE STRONGER /55-65 KTS/...WHICH WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS AS EFFECTIVE BULK SHEARS STRENGTHEN TO 45-55 KTS. VISIBLE SATELLITE AND REGIONAL RADAR IMAGERY SHOW EARLY STORM DEVELOPMENT FROM NERN CO/SWRN NEB/NWRN KS SSWWD TOWARD THE RATON MESA. INCREASING FORCING FOR UPWARD VERTICAL MOTION AND DECREASING STATIC STABILITY SHOULD SUPPORT INCREASING STORM COVERAGE ACROSS THE REGION THIS AFTERNOON INTO EVENING WITH THE POTENTIAL FOR A FEW SUPERCELLS CAPABLE OF MAINLY LARGE HAIL AND LOCALLY STRONG WIND GUSTS. STORMS MAY MERGE INTO CLUSTERS THIS EVENING WITH SOME DAMAGING WIND THREAT OVER WRN KS INTO THE PNHDLS. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1902. ...MID MS/LOWER OH VALLEYS EWD ALONG THE OH RIVER... CLUSTERS OF TSTMS CONTINUE THIS AFTERNOON FROM NE OF EVV SWWD ACROSS SRN MO/NRN AR WITHIN A MOIST LOW-LEVEL AIR MASS WHERE MLCAPES HAVE INCREASED TO 2000 J/KG. LONG LOOP RADAR IMAGERY SUGGESTS THE PRESENCE OF AN MCV OVER SWRN MO WHICH WILL CONTINUE EWD THIS AFTERNOON AND EVENING...LIKELY ENHANCING DOWNSTREAM CONVECTIVE DEVELOPMENT ALONG AND S OF LOW-LEVEL BAROCLINIC ZONE. AREA PROFILERS/VWPS INDICATE THAT VERTICAL SHEAR REMAINS RELATIVELY WEAK THOUGH THERE IS SOME LOW-LEVEL VEERING WITH HEIGHT IN THE LOWEST 3-4 KM AGL. GIVEN THIS TYPE OF ENVIRONMENT...EXPECT THE PRIMARY CONVECTIVE MODE TO REMAIN MULTICELLULAR CLUSTERS CAPABLE OF DAMAGING WINDS...ESPECIALLY IF STORMS CAN ORGANIZE A COLD POOL. FOR ADDITIONAL SHORT TERM GUIDANCE...PLEASE SEE MCD 1901. ...MID ATLANTIC COAST... A SOMEWHAT MORE CONDITIONAL THREAT OF SEVERE STORMS INCLUDING SUPERCELLS EXISTS ACROSS THE REGION THIS AFTERNOON INTO EVENING INVOF OF WARM OR QUASI-STATIONARY BOUNDARY EXTENDING FROM WEAK SURFACE LOW OVER NERN OH SEWD THROUGH W-CNTRL PA TO CNTRL NJ. PRIMARY CLOUD BAND ASSOCIATED WITH BELT OF FORCING FOR ASCENT ATTENDANT TO SHORT WAVE TROUGH MOVING THROUGH WRN PA IS CURRENTLY SPREADING E OF THE HIGHER TERRAIN INTO CNTRL PARTS OF MD/VA. HOWEVER...AIR MASS S OF BOUNDARY HAS WARMED INTO THE UPPER 80S AND LOWER 90S WHICH IS RESULTING IN MLCAPES OF 500-1000 J/KG. STORMS CURRENTLY DEVELOPING OVER FAR WRN PA/WV WILL LIKELY CONTINUE TO SPREAD EWD/SEWD LATE THIS AFTERNOON INTO EVENING WITH AN INHERENT SEVERE THREAT INCREASING ACROSS SRN PA INTO MD/NRN VA AND DE. RELATIVELY STRONG VEERING IN THE LOW-LEVELS AND THE PRESENCE OF 30-35 KT WLY MID-LEVEL FLOW IS RESULTING IN SHEAR PROFILES SUPPORTIVE OF SUPERCELLS CAPABLE OF DAMAGING WINDS AND PERHAPS A BRIEF TORNADO. ..MEAD.. 08/27/2006  From swody1 at goshenarc.org Mon Aug 28 00:56:45 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Sun, 27 Aug 2006 20:56:45 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280056 SWODY1 SPC AC 280054 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0754 PM CDT SUN AUG 27 2006 VALID 280100Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SERN CO/SWRN KS/NERN NM/THE TX AND OH PANHANDLES... ...CENTRAL AND SRN HIGH PLAINS... UPPER TROUGH CONTINUES MOVING SEWD INTO THE PLAINS...WITH LARGE-SCALE ASCENT ACROSS THE CENTRAL AND SRN HIGH PLAINS SUPPORTING STORMS FROM NWRN KS SWD ACROSS THE SRN HIGH PLAINS. STRONGEST SHEAR IS INDICATED FROM KS/CO SWD INTO THE TX PNHDL/NERN NM...WHERE PRIMARY SEVERE THREAT EXISTS THIS EVENING. WITH 1000 TO 1500 J/KG MEAN-LAYER CAPE AND KINEMATIC ENVIRONMENT CHARACTERIZED BY WEAK LOW-LEVEL FLOW BUT DEEP-LAYER SHEAR SUFFICIENT FOR ORGANIZED/ROTATING STORMS...EXPECT HAIL AND LOCALLY STRONG/GUSTY WINDS TO BE THE MAIN SEVERE THREATS WITH STRONGEST CELLS THROUGH MID TO LATE EVENING. MEANWHILE...INCREASING INSTABILITY SWD INTO THE TRANSPECOS REGION WILL SUPPORT A MORE ISOLATED SEVERE THREAT ACROSS THIS REGION -- WITH DEVELOPING SELY LOW-LEVEL JET SUPPORTING WIDESPREAD CONVECTION THROUGH THE REMAINDER OF THE PERIOD. ...OH VALLEY WWD INTO THE OZARKS/ARKLATEX... LIMITED SHEAR BUT SUFFICIENT INSTABILITY EXISTS ACROSS THE OH VALLEY REGION AND SWWD INTO THE OZARKS/ARKLATEX...WHERE WIDESPREAD THUNDERSTORMS ARE ONGOING. THOUGH OVERALL SEVERE THREAT SHOULD DIMINISH SLOWLY WITH TIME...LOCALLY STRONG/GUSTY WINDS OR MARGINALLY-SEVERE HAIL WILL BE POSSIBLE WITH STRONGEST STORMS -- MAINLY PRIOR TO MIDNIGHT. ..GOSS.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 06:01:13 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 02:01:13 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 280601 SWODY1 SPC AC 280559 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1259 AM CDT MON AUG 28 2006 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER TROUGH OVER THE CENTRAL CONUS WILL MOVE SLOWLY EWD THIS PERIOD...AS A SECOND/STRONGER FEATURE MOVES SEWD INTO THE PAC NW. WIND FIELD ALOFT ACROSS THE CENTRAL AND ERN CONUS WILL REMAIN GENERALLY WEAK...THOUGH BELT OF SLIGHTLY ENHANCED /30 TO 35 KT/ WSWLY FLOW SHOULD EXTEND FROM THE CENTRAL PLAINS ENEWD ACROSS THE OH VALLEY AROUND SRN SIDE OF UPPER TROUGH. AT THE SURFACE...BAROCLINIC ZONE EXTENDING FROM THE MID-ATLANTIC REGION WWD ACROSS THE OH ALLEY AND THEN SWWD ACROSS THE OZARKS INTO CENTRAL TX SHOULD MOVE LITTLE THIS PERIOD...AS LOW/FRONTAL WAVE MOVES EWD ACROSS THE OH VALLEY. THIS FRONT WILL BE A FOCUS FOR CONVECTIVE ACTIVITY...THOUGH COMBINATION OF INSTABILITY AND SHEAR SHOULD REMAIN ONLY MARGINALLY-SUPPORTIVE OF SEVERE STORMS THROUGH THE PERIOD. ...OH VALLEY REGION... STORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS PARTS OF THE MIDDLE OH VALLEY...WHICH SHOULD CONTRIBUTE TO WEAK LAPSE RATES AND WIDESPREAD CLOUDINESS ALONG THE FRONTAL ZONE. NONETHELESS...STORMS SHOULD INCREASE IN COVERAGE THROUGH THE AFTERNOON FROM THE MID-ATLANTIC REGION WWD TO THE MID MS VALLEY...AS POCKETS OF DESTABILIZATION DEVELOP. NAM SUGGESTS THAT A WEAK MID-LEVEL FEATURE -- DIFFICULT TO DISCERN IN WV IMAGERY ATTM -- WILL MOVE EWD ACROSS THIS REGION DURING THE AFTERNOON AHEAD OF MAIN TROUGH. THOUGH AREA WILL NOT BE UPGRADED TO SLIGHT RISK ATTM DUE TO QUESTIONS REGARDING DEGREE OF INSTABILITY...A SLIGHTLY MORE CONCENTRATED SEVERE THREAT MAY EVOLVE ACROSS THIS REGION DURING THE AFTERNOON. ...OZARKS SWWD INTO CENTRAL TX AND THEN NWWD INTO NM... THOUGH STRONGER DAYTIME HEATING IS ANTICIPATED ACROSS THIS REGION DURING THE AFTERNOON...WEAK LAPSE RATES ARE ANTICIPATED AS WIDESPREAD PRECIPITATION CONTINUES. DESTABILIZATION SHOULD BE SUFFICIENT...HOWEVER...FOR FAIRLY WIDESPREAD CONVECTIVE DEVELOPMENT -- BOTH ALONG FRONT ACROSS AR AND TX...AND IN POST-FRONTAL UPSLOPE REGIME INTO NM. DESPITE WIDESPREAD STORM DEVELOPMENT...STRONGER FLOW ALOFT SHOULD REMAIN WELL N OF THIS REGION. THEREFORE...EXPECT PULSE AND MULTICELL STORM MODES TO PREVAIL -- THUS LIMITING SEVERE POTENTIAL. THOUGH A MARGINAL SEVERE THREAT WILL EXIST...SITUATION DOES NOT WARRANT A SLIGHT RISK UPGRADE ATTM. ..GOSS.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 12:23:09 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 08:23:09 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281223 SWODY1 SPC AC 281221 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0721 AM CDT MON AUG 28 2006 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A MID LEVEL TROUGH OVER THE CENTRAL PLAINS WILL PROGRESS SLOWLY EWD TOWARD THE MID MS VALLEY BY EARLY TUESDAY. AS THIS OCCURS...A BROAD/WEAK SURFACE LOW ACROSS NRN MO WILL CONSOLIDATE AND DEVELOP EWD ACROSS THE OH VALLEY...ALONG A PRE-EXISTING E-W BAROCLINIC ZONE. IN THE WAKE OF THE SURFACE CYCLONE...A COLD FRONT WILL MOVE SEWD ACROSS OK/N TX/NW AR AND MO. THIS BAROCLINIC ZONE...ALONG WITH PRE-FRONTAL OUTFLOW BOUNDARIES AND DIFFERENTIAL HEATING ALONG THE EDGE OF THE THICKER CLOUDS...WILL SERVE AS THE PRIMARY FOCUS FOR THUNDERSTORM DEVELOPMENT THROUGH TONIGHT. ...OH VALLEY... A BROAD SWATH OF RICH LOW-MID LEVEL MOISTURE /PW VALUES OF 1.75-2.25 INCHES AND BOUNDARY LAYER DEWPOINTS AOA 70 F/ IS PRESENT FROM THE SRN PLAINS TO THE OH VALLEY AND NRN MID ATLANTIC REGION. WIDESPREAD PRECIPITATION THE PAST TWO DAYS WITHIN THIS SWATH HAS REDUCED LOW-MID LEVEL LAPSE RATES TO ROUGHLY MOIST ADIABATIC...WHICH WILL LIMIT POTENTIAL INSTABILITY ALONG THE FRONT AND IN ADVANCE OF THE SURFACE LOW. ALSO...VERTICAL SHEAR WILL REMAIN WEAK IN THE MAJORITY OF THE WARM SECTOR. RELATIVELY STRONGER LOW-LEVEL AND DEEP LAYER SHEAR WILL BE CONFINED TO A NARROW CORRIDOR IMMEDIATELY E OF THE SURFACE LOW ACROSS THE OH VALLEY...WHERE FORECAST SOUNDINGS/HODOGRAPHS SUGGEST SOME POTENTIAL FOR SUPERCELLS. AN ISOLATED TORNADO CANNOT BE RULED OUT...ALONG WITH STRONG WIND GUSTS...BUT THE WEAK INSTABILITY/MOIST PROFILES SUGGEST THAT ANY SEVERE STORM THREAT SHOULD BE REMAIN MARGINAL. ..THOMPSON/CROSBIE.. 08/28/2006  From swody1 at goshenarc.org Mon Aug 28 16:31:41 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Mon, 28 Aug 2006 12:31:41 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 281631 SWODY1 SPC AC 281630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT MON AUG 28 2006 VALID 281630Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... SEASONABLY STRONG SHORTWAVE TROUGH OVER ERN NEB EXPECTED DEAMPLIFY SLIGHTLY AS IT MOVES E INTO ERN IA BY 12Z TUESDAY. AT THE SURFACE...WEAK WAVE NOW IN CNTRL IL SHOULD DRIFT E ALONG STALLED FRONT EXTENDING E INTO SRN OH. IN WAKE OF THE LOW...COLD FRONT SHOULD SETTLE SLOWLY SE ACROSS PARTS OF TX/OK/AR AND LWR TN/OH VLYS. ...OH VLY/CNTRL APLCNS... VERY MOIST /PWS AOA 2 INCHES/...WEAKLY UNSTABLE AIR WILL PREVAIL FROM THE LWR OH VLY NEWD INTO FAR WRN PA/WV TODAY...WHERE MODEST SURFACE HEATING WILL CONTINUE ALONG AND S OF STALLED SURFACE FRONT. AREA VWPS...MORNING SOUNDINGS AND LATEST MODEL FORECASTS SUGGEST THAT A BAND OF 30+ KT WSWLY MID LEVEL FLOW WILL PERSIST/SPREAD NEWD UP THE OH VLY ON SERN FRINGE OF NEB/IA SHORTWAVE IMPULSE. PRESENCE OF THIS WEAK JET STREAK WILL YIELD MODERATE...UNIDIRECTIONAL CLOUD LAYER WIND PROFILES WITH ANY STORMS FORMING IN WARM SECTOR. COUPLED WITH HI PWS...SETUP MAY PROMOTE DEVELOPMENT OF A FEW SMALL SCALE BOWING SEGMENTS WITH LOCALLY DAMAGING WIND ACROSS KY/SRN WV. A BIT FARTHER N...WEAK BUT BACKED LOW LEVEL FLOW WILL ENLARGE LOW LEVEL HODOGRAPH CURVATURE INVOF STATIONARY FRONT FROM CNTRL/SRN IND ENE INTO CNTRL/SRN OH...WRN WV AND NRN KY. STORMS LIKELY TO FORM IN AREA OF ENHANCED CONVERGENCE IMMEDIATELY DOWNSTREAM FROM IL/IND SURFACE WAVE MAY DEVELOP WEAK LOW LEVEL MESOCYCLONES AND YIELD A TORNADO OR TWO LATER THIS AFTERNOON THROUGH EARLY TONIGHT. BUT LIMITED DEGREE OF INSTABILITY SHOULD KEEP SUCH ANY ACTIVITY BRIEF/ ISOLATED. ..CORFIDI/GRAMS.. 08/28/2006  From swody1 at goshenarc.org Wed Aug 30 06:07:07 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 02:07:07 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 300602 SWODY1 SPC AC 300600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT WED AUG 30 2006 VALID 301200Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... UPPER PATTERN IS FORECAST TO BECOME MORE HIGHLY-AMPLIFIED THROUGH THE PERIOD. SEASONABLY STRONG UPPER TROUGH WILL CONTINUE MOVING EWD ACROSS THE NWRN CONUS. THIS TROUGH WILL IMPINGE ON A SECOND TROUGH OVER THE MIDWEST...WHOSE EWD PROGRESS WILL BE HINDERED BY ERNESTO MOVING NWD ACROSS FL AND INTO THE SWRN ATLANTIC. THOUGH A COLD FRONT WILL MOVE ACROSS MT/WY AND APPROACH THE NRN PLAINS DURING THE SECOND HALF OF THE PERIOD...CONVECTIVE THREAT SHOULD BE LIMITED BY DRY/CAPPED BOUNDARY LAYER. ELSEWHERE...WEAK BAROCLINIC ZONE WILL LINGER FROM THE CAROLINAS INTO GA/AL...BUT WEAK LAPSE RATES ASSOCIATED WITH ONGOING PRECIPITATION WITHIN TROPICAL AIRMASS SPREADING NWD SHOULD LIMIT POTENTIAL FOR DESTABILIZATION AND THUS SEVERE POTENTIAL. ...ERN FL PENINSULA... RELATIVELY STRONG/WEAKLY-VEERING FLOW IN THE LOWER TROPOSPHERE WITHIN THE NERN QUADRANT OF ERNESTO WILL REMAIN ACROSS THE ERN HALF OF THE FL PENINSULA THROUGH THE FIRST HALF OF THE PERIOD. GIVEN VERY MOIST BOUNDARY LAYER...SHEAR MAY SUPPORT LOW-LEVEL ROTATION WITHIN STRONGER CONVECTIVE CELLS -- AND PERHAPS AN ISOLATED/BRIEF TORNADO. THREAT SHOULD DIMINISH OVERNIGHT AS ERNESTO MOVES OFF THE E CENTRAL FL COAST. ...THE CAROLINAS... WIDESPREAD PRECIPITATION WILL LIKELY BE ONGOING ACROSS THE CAROLINAS AT THE START OF THE PERIOD...AND SHOULD CONTINUE WITHIN TROPICAL AIRMASS SPREADING NWD AHEAD OF ERNESTO. WEAK LAPSE RATES WILL LIMIT DESTABILIZATION...BUT SLIGHTLY-ENHANCED BELT OF WSWLY MID-LEVEL FLOW ON SERN PERIPHERY OF UPPER TROUGH MAY SUPPORT A FEW ORGANIZED STORMS...AND ASSOCIATED POTENTIAL FOR ISOLATED STRONG/GUSTY WINDS. ..GOSS.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 12:38:02 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 08:38:02 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301239 SWODY1 SPC AC 301236 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0736 AM CDT WED AUG 30 2006 VALID 301300Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...E CENTRAL FL TODAY... TROPICAL STORM ERNESTO IS DRIFTING NWD OVER S FL THIS MORNING...AND IS FORECAST TO EMERGE OFF THE E CENTRAL FL COAST BY EARLY TONIGHT /SEE LATEST NHC ADVISORIES FOR ADDITIONAL INFORMATION/. LOCAL VWP/S SHOW A NARROW CORRIDOR OF SOMEWHAT ENHANCED VERTICAL SHEAR COLOCATED WITH A BROKEN OUTER CONVECTIVE BAND BETWEEN PBI AND MLB. THIS BAND SHOULD SHIFT NWD INTO THE MLB-DAB AREAS DURING THE DAY...WHERE AN ISOLATED/BRIEF TORNADO COULD OCCUR. HOWEVER...THE RATHER POOR CONVECTIVE STRUCTURE OF THE STORM AND MODEST WIND FIELDS SUGGEST THAT ANY TORNADO THREAT SHOULD REMAIN MARGINAL. ...SE STATES TODAY... A MID LEVEL TROUGH ALONG AN AXIS FROM NW AR TO NRN IL THIS MORNING WILL DRIFT ESEWD OVER THE OH/MS VALLEYS THROUGH TONIGHT. AT THE SURFACE...A COLD FRONT WILL SAG SWD ACROSS VA TOWARD NC AS SURFACE PRESSURE RISE ACROSS NEW ENGLAND IN THE WAKE OF A NRN STREAM TROUGH. THE FRONT WILL ALSO MOVE VERY SLOWLY SEWD ACROSS THE LOWER MS VALLEY AND SRN APPALACHIANS. A MOIST/TROPICAL AIR MASS IS IN PLACE E OF THE FRONT...WHICH WILL SUPPORT SCATTERED THUNDERSTORMS THROUGH THE PERIOD ACROSS THE SE STATES. DESPITE MODEST MID LEVEL LAPSE RATES...DAYTIME HEATING WITHIN CLOUD BREAKS COULD ALLOW MLCAPE VALUES TO REACH 1500-2500 J/KG THIS AFTERNOON. VERTICAL SHEAR WILL BE RATHER WEAK IN THE OPEN WARM SECTOR WHERE INSTABILITY SHOULD BE GREATER...WITH RELATIVELY STRONGER SHEAR ALONG THE FRONT IN CLOSER PROXIMITY TO THE BELT OF 25-30 KT MID LEVEL FLOW. THE MODEST SHEAR/INSTABILITY MAY SUPPORT MULTICELL STORMS WITH ISOLATED DAMAGING WINDS TODAY FROM AL TO THE CAROLINAS/SRN VA. ...NRN HIGH PLAINS THIS AFTERNOON/TONIGHT... A DEEP MID LEVEL TROUGH OVER WA/ORE THIS MORNING...AND AN ASSOCIATED COLD FRONT...WILL PROGRESS EWD OVER ID/MT/NW WY BY TONIGHT. MEANWHILE...A LEE CYCLONE WILL DEEPEN ACROSS SE MT DOWNSTREAM FROM THE MID LEVEL WAVE. LOW-LEVEL MOISTURE IS LIMITED ACROSS THE PLAINS IN THE WAKE OF A PRIOR FRONTAL PASSAGE...WITH BOUNDARY LAYER DEWPOINTS RANGING FROM THE MID 40S TO LOWER 50S. A PLUME OF STEEP MID LEVEL LAPSE RATES WILL OVERSPREAD THE MARGINALLY MOIST BOUNDARY LAYER ALONG AND E OF THE LEE TROUGH IN ADVANCE OF THE MID LEVEL WAVE. THE POOR MOISTURE AND SMALL CAPE SUGGEST THAT SURFACE-BASED CONVECTION WILL BE SPARSE AND LIKELY CONFINED TO THE IMMEDIATE LEE CYCLONE/TROUGH WHERE SURFACE TEMPERATURES WARM WELL INTO THE 90S. OTHER ELEVATED STORMS MAY FORM IN A NARROW POST-FRONTAL BAND TONIGHT ACROSS NE MT/NW ND IN CONJUCTION WITH MID LEVEL MOISTENING AND COOLING OF THE COLUMN...THOUGH WEAK INSTABILITY WILL LIMIT THE OVERALL CONVECTIVE THREAT. ..THOMPSON/CROSBIE.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 16:22:50 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 12:22:50 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301622 SWODY1 SPC AC 301621 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT WED AUG 30 2006 VALID 301630Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MUCH OF THE U.S. IS ENTERING A BLOCKING TYPE PATTERN AS MID/UPPER LEVEL LOW BECOMES ANCHORED OVER IL/IND. MID/UPPER LEVEL TROUGH OVER THE NWRN U.S. WILL MOVE EWD ACROSS THE NRN PLATEAU INTO THE NRN ROCKIES AS MID/UPPER LEVEL RIDGE HAS BEEN PUSHED INTO THE SWRN U.S. AND EXTENDS NEWD INTO THE UPPER MIDWEST. MEANWHILE...T.D. ERNESTO IS FORECAST TO MOVE NNEWD DURING THE PERIOD. SEE LATEST STATEMENTS FROM NHC/TPC ON T.D. ERNESTO. ...E CENTRAL AND NERN FL INTO SERN COASTAL GA... GIVEN THE FORECAST TRACK OF T.D. ERNESTO BY NHC/TPC...OUTER BANDS OF THE STORMS WILL MOSTLY BE EFFECTING COASTAL AREAS FROM MLB NWD TOWARDS SAV. THIS IS WHERE THE FAVORABLE QUADRANT FOR ROTATING UPDRAFTS WILL BE ASSOCIATED WITH ERNESTO DURING THE PERIOD. LOOKS LIKE THE BEST THREAT FOR ISOLATED TORNADOES/WATERSPOUTS WILL BE COASTAL AND MARINE ZONE AREAS OFF THE FL/SERN GA COAST. ...PARTS OF NC AND SC INTO ERN TN... MORNING SURFACE ANALYSIS SHOWS QUASI-STATIONARY BOUNDARY EXTENDING FROM EXTREME SERN VA WSWWD THRU SWRN NC INTO CENTRAL MS. VISIBLE SATELLITE IMAGERY SHOWS AREA OF BEST INSOLATION WILL BE IN THE VICINITY AND S OF THE BOUNDARY WHERE AIR MASS HAS ALREADY DESTABILIZED WITH MLCAPES AROUND 2500 J/KG. THERE IS ALSO THE PRESENCE OF 30-40 KT DEEP LAYER SHEAR EFFECTIVE LOCATED IN FAVORABLE UPPER LEVEL JET ENTRANCE REGION TO ENHANCE UVVS ACROSS THIS AREA THROUGH EARLY TONIGHT. THUS...MULTICELLULAR STORMS ARE EXPECTED THIS AFTERNOON AND EARLY TONIGHT WITH THE POSSIBILITY OF WET MICROBURSTS. ...NRN HIGH PLAINS... MODELS GENERATE AREA OF POSSIBLE CONVECTION OVER THE NRN HIGH PLAINS FOR LATER THIS AFTERNOON/EARLY EVENING. ANALYSIS OF FORECAST SOUNDINGS SHOWED VERY STEEP LAPSE RATES NEAR/AROUND 9C/KM ...YET WITH A HIGH LFC AND DRYING IN LOW/MID LEVELS BY THIS EVENING AHEAD OF THE APPROACHING TROUGH. THUS...WOULD EXPECT THAT ISOLATED THUNDERSTORMS COULD DEVELOP LATER THIS AFTERNOON BUT REMAIN BELOW SEVERE LEVELS DUE TO LIMITED MOISTURE/INSTABILITY. ..MCCARTHY/JEWELL.. 08/30/2006  From swody1 at goshenarc.org Wed Aug 30 20:02:58 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 16:02:58 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 301959 SWODY1 SPC AC 301957 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0257 PM CDT WED AUG 30 2006 VALID 302000Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SOUTHEAST AND MID ATLANTIC... ...SOUTHEAST TO MID ATLANTIC... ROBUST MULTICELLULAR CONVECTION HAS ERUPTED WITHIN VERY MOIST AND STRONGLY UNSTABLE AIR MASS FROM SRN AL/GA BORDER AREA NEWD ACROSS THE CAROLINAS TO VA/WV. PRESENCE OF RESIDUAL FRONT/OUTFLOW AND WEAK FRONTAL WAVE ACROSS NC HAS FOCUSED MOST VIGOROUS STORMS ACROSS ECNTRL NC WITH ADDITIONAL ACTIVITY INCREASING ACROSS THE MOUNTAINS AND OVER THE COASTAL PLAIN. WHILE STRONGER DEEP-LAYER SHEAR RESIDES NORTH OF NC CONVECTION...AND LARGER SCALE SUPPORT TO SUSTAIN UPWARD MOTION APPEARS LIMITED...MAGNITUDE OF INSTABILITY AND COVERAGE OF CONVECTION SHOULD RESULT IN SCATTERED DAMAGING WINDS AND SOME SEVERE HAIL THROUGH EARLY EVENING. LONG-LIVED SUPERCELL HAS BEEN TRACKING EAST ACROSS WRN WV AND APPEARS LINKED WITH SUB-SYNOPTIC SCALE LOW TRAVELING EAST ALONG LOW LEVEL BAROCLINIC ZONE. SHEAR ACROSS THE AREA REMAINS SUPPORTIVE OF STORM ROTATION AND INSTABILITY HAS BEEN STEADILY INCREASING ALONG AND SOUTH OF THE BOUNDARY. THUS...SEVERE HAIL AND WIND THREAT MAY PERSIST FROM WV EWD INTO PARTS OF WRN/SCNTRL VA OVER THE NEXT FEW HOURS. ...ERN FL... T.D. ERNESTO APPEARS TO BE ACCELERATING NNEWD TOWARD ERN FL LATE THIS AFTERNOON WITH THE CENTER OF THE CIRCULATION ON TRACK TO MOVE OVER THE EAST COAST LATE TONIGHT. WIND FIELDS IN THE RIGHT FRONT QUADRANT OF THE CIRCULATION WILL REMAIN MARGINALLY SUPPORTIVE OF LOW LEVEL UPDRAFT ROTATION AND AN ISOLATED TORNADO CANNOT BE RULED OUT. HOWEVER...OVERALL DISORGANIZED BANDING AND WEAK INSTABILITY AHEAD OF THE LOW TRACK DO NOT...ATTM...APPEAR PARTICULARLY SUPPORTIVE FOR DISCRETE AND PERSISTENT STORMS. ...SRN AZ... VERY STRONG INSTABILITY HAS DEVELOPED ACROSS SRN AZ WHERE DEWPOINTS IN THE 60S AND INTENSE SURFACE HEATING ARE CONTRIBUTING TO MLCAPE AROUND 2000 J/KG. FORCING AND SHEAR ACROSS THE REGION ARE EXPECTED TO REMAIN WEAK BUT ISOLATED CONVECTION COULD POSE SOME DAMAGING WIND POTENTIAL INTO THE EVENING. ...NRN HIGH PLAINS... NARROW N-S AXIS OF STRONG INSTABILITY HAS DEVELOPED NEAR LEE-TROUGH/DRYLINE ACROSS THE HIGH PLAINS. WHILE CAP REMAINS QUITE STRONG ACROSS MUCH OF THE REGION...RAP MORNING SOUNDING ADJUSTED FOR LATEST SURFACE CONDITIONS REVEALS THAT INHIBITION ACROSS THIS AREA HAS WEAKENED CONSIDERABLY. A FEW MORE HOURS OF HEATING/MIXING...AND PERHAPS OROGRAPHIC FORCING NEAR THE BLACK HILLS...MAY PROVE SUFFICIENT FOR ISOLATED STORM DEVELOPMENT. EFFECTIVE SHEAR APPROACHING 30KT WILL FURTHER ENHANCE UPDRAFTS AND CONTRIBUTE TO SEVERE HAIL/WIND POTENTIAL WITH ANY STORMS THAT MAY FORM. ADDITIONAL ACTIVITY MAY DEVELOP LATER TONIGHT ACROSS PARTS OF THE NRN PLAINS IN RESPONSE TO APPROACHING UPPER TROUGH AND COLD FRONT. STRONG EML AND LIMITED MOISTURE ARE EXPECTED TO RESTRICT SEVERE POTENTIAL WITH THIS CONVECTION. ..CARBIN.. 08/30/2006  From swody1 at goshenarc.org Thu Aug 31 00:46:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Wed, 30 Aug 2006 20:46:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310048 SWODY1 SPC AC 310046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 PM CDT WED AUG 30 2006 VALID 310100Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SERN U.S... ERNESTO CONTINUES ITS NNEWD MOVEMENT ALONG THE ECNTRL FL COAST THIS EVENING. STRONGER SHEAR ASSOCIATED WITH CIRCULATION CENTER WILL SOON BE MOSTLY OFFSHORE...ALONG WITH ANY MEANINGFUL THREAT FOR SUPERCELLS. IT APPEARS THE GREATEST THREAT FOR STRONG STORMS THE REST OF THE PERIOD WILL BE WELL INLAND FROM THE FL PANHANDLE...NEWD AROUND THE PERIPHERY OF THE TROPICAL CIRCULATION INTO COASTAL NC. HOWEVER...00Z SOUNDINGS FROM THIS REGION SUGGEST LOW LEVEL LAPSE RATE ENVIRONMENT IS BEGINNING TO STABILIZE. ADDITIONAL BOUNDARY LAYER COOLING WILL NOT PROVE HELPFUL FOR SEVERE DEVELOPMENT THE REST OF TONIGHT. GUSTY WINDS ARE THE PRIMARY SEVERE THREAT WITH MCS CLUSTERS ACROSS THE FL PANHANDLE AND OVER COASTAL NC. ...BLACK HILLS/NEB PANHANDLE... ISOLATED THUNDERSTORM ACTIVITY ACROSS WRN SD INTO THE NWRN NEB PANHANDLE IS STRUGGLING TO MAINTAIN BOUNDARY LAYER PARCEL INFLOW. SIGNIFICANT AMOUNT OF INHIBITION WILL LIKELY RESULT IN THIS ACTIVITY BECOMING ROOTED ABOVE THE BOUNDARY LAYER SHORTLY. LLJ MAY MAINTAIN THIS CONVECTION FOR SEVERAL HOURS BUT SEVERE THREAT APPEARS RATHER LOW. ...AZ... STEEP LAPSE RATES ACROSS THE AZ DESERTS WILL PROVE SOMEWHAT SUPPORTIVE OF GUSTY WINDS BENEATH SCATTERED THUNDERSTORMS PROPAGATING SWWD INTO YUMA COUNTY. COLD POOL IS NOT PARTICULARLY ESTABLISHED SO SEVERE THREAT SHOULD REMAIN ISOLATED. ..DARROW.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 05:50:55 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 01:50:55 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 310551 SWODY1 SPC AC 310549 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1249 AM CDT THU AUG 31 2006 VALID 311200Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL PLAINS... LEE CYCLONE SHOULD DEVELOP OVER ERN CO...WELL AHEAD OF MAIN FRONTAL BOUNDARY THAT SHOULD PLUNGE SWD THROUGH WY LATER THIS MORNING. LATE EVENING MODEL GUIDANCE SUGGESTS ELY COMPONENT SHOULD DEVELOP THROUGH AT LEAST 2KM ACROSS THE CENTRAL HIGH PLAINS BY MID AFTERNOON WHICH WILL ENHANCE LOW LEVEL CONVERGENCE/ASCENT WITHIN SLIGHT RISK REGION. ALTHOUGH LARGE SCALE HEIGHT FALLS WILL SPREAD ACROSS THE NRN PLAINS...SRN INFLUENCE OF UPPER TROUGH SHOULD STRENGTHEN WLY FLOW ALOFT AS FAR SOUTH AS I-70...ENHANCING DEEP LAYER SHEAR WHERE THUNDERSTORM DEVELOPMENT IS EXPECTED. IT APPEARS SUFFICIENT VERTICAL SHEAR WILL EXIST ACROSS ERN CO INTO WRN KS TO SUPPORT STORM ROTATION AND SUPERCELL DEVELOPMENT...ESPECIALLY EARLY IN CONVECTIVE CYCLE. IN THE ABSENCE OF SIGNIFICANT INHIBITION...CONVECTION SHOULD EVOLVE IN THE 20Z-21Z TIME FRAME OVER NERN CO INTO SWRN NEB...THEN SPREAD/DEVELOP SEWD ACROSS MUCH OF ERN CO/WRN KS. LARGE HAIL SHOULD ACCOMPANY THIS ACTIVITY...ALONG WITH SOME THREAT FOR DAMAGING WINDS...ESPECIALLY AS CONVECTION MERGES AND EVOLVES INTO CLUSTER-TYPE ECHOES. ONE OR MORE SMALL MCS/S SHOULD SPREAD SEWD TOWARD NWRN OK/NRN TX PANHANDLE AFTER MIDNIGHT. ...ERNESTO... CENTER OF TROPICAL STORM ERNESTO HAS MOVED OFF THE FL COAST AND IS LIFTING NNEWD TOWARD THE SC/NC COAST. STRONGER CONVECTIVE BANDS WILL SPREAD INTO THE CAROLINAS LATER TODAY WITH AT LEAST SOME THREAT FOR MARGINALLY SEVERE WIND GUSTS...OR PERHAPS A WEAK TORNADO. IN THE ABSENCE OF SIGNIFICANT STRENGTHENING OVER THE WARMER ATLANTIC WATERS...LOW PROBABILITIES WILL SUFFICE FOR THE SERN U.S. ...AZ... PRECIPITABLE WATER VALUES REMAIN QUITE HIGH ACROSS THE LOWER ELEVATION REGIONS OF AZ THIS MORNING...WITH READINGS WELL ABOVE AN INCH IN MOST PLACES. LATEST WV IMAGERY SUGGESTS A WEAK UPPER DISTURBANCE IS LOCATED JUST SW OF AZ OVER THE NRN BAJA REGION/GULF OF CA...LIFTING NEWD AROUND THE UPPER RIDGE. TIMING OF THIS FEATURE IS NOT PARTICULARLY FAVORABLE FOR LATE AFTERNOON CONVECTION...HOWEVER PARCELS SHOULD ONCE AGAIN REACH THEIR LFC WITH MID 90S TO NEAR 100F. ISOLATED STORMS MAY PRODUCE GUSTY WINDS GIVEN HIGH WATER CONTENT...STEEP LAPSE RATE ENVIRONMENT. ..DARROW/CROSBIE.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 12:35:42 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 08:35:42 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311235 SWODY1 SPC AC 311234 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0734 AM CDT THU AUG 31 2006 VALID 311300Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS TODAY THROUGH TONIGHT ACROSS THE ERN CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS THE CENTRAL HIGH PLAINS... ...ERN CAROLINAS THROUGH TONIGHT... TROPICAL STORM ERNESTO IS EXPECTED TO MAKE LANDFALL TONIGHT NEAR THE NC/SC BORDER AND CONTINUE MOVING NWD ACROSS ERN NC THROUGH 01/12Z. MODEST STRENGTHENING OF THE TROPICAL CYCLONE PRIOR TO LANDFALL WILL RESULT IN A BROADER AREA OF STRONGER LOW-MID LEVEL FLOW IN ADVANCE OF THE STORM CORE. ADDITIONALLY...THE FORWARD QUADRANTS OF ERNESTO WILL BEGIN TO INTERACT WITH A BAROCLINIC ZONE ACROSS THE ERN CAROLINAS. THIS WILL PROVIDE A CORRIDOR OF ENHANCED LOW-LEVEL SHEAR TO FOCUS THE SUPERCELL/TORNADO THREAT AS BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 70S AND ASSOCIATED LOW-LEVEL BUOYANCY SPREAD INLAND LATER TODAY AND TONIGHT. ...CENTRAL HIGH PLAINS THIS AFTERNOON/EVENING... A STRONG SURFACE COLD FRONT WILL MOVE EWD ACROSS THE NRN PLAINS IN ASSOCIATION WITH A MID LEVEL TROUGH OVER THE NRN ROCKIES...AND THE FRONT WILL MOVE SWD INTO ERN CO. BOUNDARY LAYER DEWPOINTS OF 58-62 F ARE RETURNING NWD ACROSS THE HIGH PLAINS IN A NARROW CORRIDOR E OF THE LEE TROUGH. THIS MOISTURE...COMBINED WITH AFTERNOON TEMPERATURES OF 85-90 F AND STEEP MID LEVEL LAPSE RATES...WILL RESULT IN MODERATE INSTABILITY IN THE WARM SECTOR BY AFTERNOON /MLCAPE VALUES OF 1500-2000 J/KG/. EXPECT THUNDERSTORMS TO DEVELOP BY MID-LATE AFTERNOON NEAR THE COLD FRONT/LEE TROUGH INTERSECTION IN NE CO...AND CONVECTION SHOULD SPREAD EWD/SEWD THROUGH THE EVENING ACROSS SW NEB/ERN CO/WRN KS. VERTICAL SHEAR IS FORECAST TO REMAIN SOMEWHAT MARGINAL FOR SUPERCELLS...THOUGH SUFFICIENT FOR PERSISTENT MULTICELL CLUSTERS. LARGE HAIL AND A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREATS FROM ABOUT 21-03Z. ..THOMPSON/CROSBIE.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 16:23:21 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 12:23:21 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 311623 SWODY1 SPC AC 311622 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CDT THU AUG 31 2006 VALID 311630Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE ERN CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL HIGH PLAINS... ...ERN CAROLINAS... LATEST INFORMATION FROM NHC INDICATES ERNESTO HAS STRENGTHENED OVERNIGHT OFF THE GA COAST. THE CIRCULATION CENTER IS FORECAST TO MOVE NNEWD MAKING LANDFALL NEAR THE SC/NC BORDER AROUND 05-06Z AND CONTINUING INTO ERN NC DURING THE REMAINDER OF THE PERIOD. STRONGER LOW LEVEL WIND FIELDS AND ATTENDANT VERTICAL SHEAR WITHIN NERN QUADRANT OF THE SYSTEM WILL GRADUALLY SPREAD ONSHORE THIS AFTERNOON AND TONIGHT INTO COASTAL REGIONS OF NERN SC AND NC...INCREASING POTENTIAL FOR A FEW SUPERCELL THUNDERSTORMS. IN ADDITION...COASTAL BOUNDARY IN ADVANCE OF ERNESTO CURRENTLY LOCATED ALONG THE NC COAST IS EXPECTED TO MOVE INLAND BY TONIGHT AND FURTHER ENHANCE LOW LEVEL SHEAR PROFILES. THIS MAY PROVIDE A FOCUS FOR SUPERCELL DEVELOPMENT WITH THREAT FOR ISOLATED TORNADOES CONTINUING THROUGH THE OVERNIGHT HOURS. ...CENTRAL HIGH PLAINS... SRN PORTION OF UPPER SHORT WAVE TROUGH MOVING ACROSS MT/WY IS EXPECTED TO MOVE INTO THE NRN PLAINS TONIGHT. THIS SYSTEM WILL FORCE SURFACE COLD FRONT EWD/SEWD ACROSS THE NRN AND CENTRAL PLAINS THIS AFTERNOON AND TONIGHT. 12Z AREA SOUNDINGS EXHIBIT STEEP MID LEVEL LAPSE RATES...AND SURFACE DEW POINTS IN THE 50S TO LOWER 60S COUPLED WITH STRONG DIABATIC INSOLATION THIS AFTERNOON WILL RESULT IN MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE OF 1500-2000 J/KG. ALTHOUGH STRONGEST DYNAMIC FORCING FOR LARGE SCALE ASCENT WILL BE LOCATED WELL NORTH OF THE PLAINS...PROGRESSION OF A WEAK UPPER LEVEL JET STREAK ACROSS THE CENTRAL ROCKIES WITH DIFFLUENT MID/UPPER LEVEL FLOW DOWNSTREAM OVER THE HIGH PLAINS...LOW LEVEL CONVERGENCE ALONG THE ADVANCING COLD FRONT...AND UPSLOPE LOW LEVEL WIND COMPONENT FAVOR DEVELOPMENT OF THUNDERSTORMS LATER THIS AFTERNOON AND EVENING FROM PARTS OF NERN CO INTO WRN/CENTRAL NEB. THIS ACTIVITY IS EXPECTED TO SPREAD EWD/SEWD INTO SERN CO/WRN KS AND POSSIBLY THE OK PANHANDLE REGION THROUGH THE EVENING BEFORE DIMINISHING LATER AT NIGHT. DEEP LAYER VERTICAL SHEAR OF 30-35 KT WILL BE SUPPORTIVE OF PRIMARILY MULTICELLULAR CONVECTIVE STRUCTURES ALTHOUGH ISOLATED SUPERCELLS WILL ALSO BE POSSIBLE. LARGE HAIL AND OCCASIONAL DAMAGING WIND GUSTS WILL BE POSSIBLE WITH STRONGER CELLS. ..WEISS/JEWELL.. 08/31/2006  From swody1 at goshenarc.org Thu Aug 31 20:01:43 2006 From: swody1 at goshenarc.org (Severe Weather Outlook Day 1) Date: Thu, 31 Aug 2006 16:01:43 -0400 Subject: [SWODY1] SWODY1 Message-ID: ACUS01 KWNS 312002 SWODY1 SPC AC 312000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT THU AUG 31 2006 VALID 312000Z - 011200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH PLAINS AND CNTRL PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE ERN CAROLINAS... ...ERN CO/WRN KS/SW NEB... LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN UPPER-LEVEL RIDGE IN PLACE ACROSS THE CNTRL HIGH PLAINS WITH A DISTURBANCE/VORTICITY MAX MOVING EWD THROUGH CNTRL AND SRN CO ATTM. AT THE SFC...A MOIST AXIS WITH DEWPOINTS IN THE 60-65 F RANGE EXISTS ACROSS WRN KS AND FAR NE CO WHERE OBJECTIVE ANALYSIS SHOWS MODERATE INSTABILITY WITH MLCAPE VALUES RANGING FROM 1500 TO 2000 J/KG. AS THE DISTURBANCE MOVES INTO THE PLAINS OF CO LATE THIS AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE IN FAR NE CO ALONG THE LEADING EDGE OF ASCENT AND ALONG THE WRN EDGE OF THE INSTABILITY AXIS. THE NAM AND GFS SOLUTIONS ARE CONSISTENT WITH THIS SCENARIO AND IT APPEARS AN MCS WILL DEVELOP AND MOVE EWD INTO NW KS BY THIS EVENING. FORECAST SOUNDINGS ACROSS THE REGION LATE THIS AFTERNOON SHOW SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STORMS AND SHEAR PROFILES MAY INCREASE THIS EVENING AS A 30-40 KT LOW-LEVEL JET STRENGTHENS ACROSS WRN KS. THIS COMBINED WITH THE INSTABILITY AND STEEP LAPSE RATES ALREADY IN PLACE SUGGEST SUPERCELLS WITH LARGE HAIL WILL BE LIKELY AS THE MCS ORGANIZES THIS EVENING. THE SEVERE THREAT MAY ALSO EXPAND SWD WITH TIME AS THE MCS ORGANIZES ACROSS WRN KS THIS EVENING. ...ERN SC/ERN NC... TROPICAL STORM ERNESTO WILL CONTINUE TO MOVE NWD THIS AFTERNOON AND IS FORECAST TO MOVE INLAND NEAR WILMINGTON NC OVERNIGHT. AT THE SFC...ELY FLOW WILL STRENGTHEN ACROSS ERN SC AND ERN NC AHEAD OF THE APPROACHING TROPICAL STORM. THIS WILL INCREASE SFC DEWPOINTS ACROSS THE REGION FROM EAST TO WEST ALLOWING MODERATE INSTABILITY TO DEVELOP TONIGHT. FORECAST SOUNDINGS ALSO INCREASE LOW-LEVEL SHEAR PROFILES AFTER MIDNIGHT ALONG AND NORTH OF THE CENTER OF TROPICAL STORM ERNESTO WITH THE STRONGER DEEP LAYER SHEAR PROFILES REMAINING EAST OF THE CENTER. THIS SUGGESTS ROTATING STORMS WITH TORNADO POTENTIAL WILL BE MOST LIKELY FROM FAR ERN SC EXTENDING NWD INTO ERN NC. THE TORNADO THREAT SHOULD BE GREATEST LATE TONIGHT AS THE INNER RAINBANDS OF TROPICAL STORM ERNESTO MOVE FURTHER INLAND. ..BROYLES.. 08/31/2006