From swody2 at goshenarc.org Tue Jun 6 06:12:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 06 Jun 2006 02:12:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060609 SWODY2 SPC AC 060608 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT TUE JUN 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY TO MIDDLE TN... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE PART OF THE INTERIOR NORTHWEST/NRN ROCKIES/NRN HIGH PLAINS... ...SYNOPSIS... EXPANSIVE WCNTRL U.S. UPPER RIDGE IS FORECAST TO BEGIN TO BREAK DOWN ACROSS THE NRN ROCKIES AND NRN PLAINS THROUGH WEDNESDAY AS NUMEROUS SHORT WAVE IMPULSES RIDE AROUND THE WRN/NRN PERIPHERY OF THE ANTICYCLONE AND COMBINE WITH STRONGER HEIGHT FALLS ACCOMPANYING A PACIFIC SHORT WAVE TROUGH MOVING INLAND OVER WA/ORE THROUGH EARLY THURSDAY. A DEAMPLIFYING SHORT WAVE IMPULSE... CURRENTLY CROSSING THE UPPER MS VALLEY ON THE ERN FLANK OF THE LARGE UPPER HIGH...IS FORECAST TO SPREAD SEWD FROM THE GREAT LAKES TO THE OH VALLEY THROUGH WEDNESDAY EVENING. THIS SYSTEM WILL ACT TO REESTABLISH THE MEAN TROUGH SITUATED ACROSS THE ERN SEABOARD AS EXISTING/PERSISTENT DEEP LAYER LOW OVER THIS REGION IS EJECTED NEWD OFF THE NEW ENGLAND COAST THROUGH EARLY THURSDAY. ...MIDWEST TO LOWER MS VALLEY/NRN GULF COAST... INCREASINGLY DIFFLUENT MID LEVEL FLOW WILL DEVELOP ACROSS THE MIDWEST AND LOWER MS VALLEY THROUGH WEDNESDAY AFTERNOON AS WEAK HEIGHT FALLS ASSOCIATED WITH GREAT LAKES/MIDWEST SHORT WAVE TROUGH SPREAD SEWD ON THE ERN FLANK OF THE LARGE UPPER RIDGE. LOW LEVEL MOISTURE FOCUSED ALONG WEAK WIND SHIFT WILL COMBINE WITH SURFACE HEATING TO PRODUCE A NARROW AXIS OF STRONGER INSTABILITY FROM LA/AR NEWD TO IND/OH. STRONGER LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH THE SHORT WAVE TROUGH IS FORECAST TO EXIST ACROSS THE OH VALLEY AREA...COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. ADDITIONALLY...STRONGER MID LEVEL NWLY FLOW WILL CONTRIBUTE TO MORE THAN ADEQUATE SHEAR ACROSS THIS REGION FOR ORGANIZED STORMS. ACTIVITY MAY BUILD/INCREASE SWWD INTO INSTABILITY AXIS FROM SRN IND ACROSS KY AND MIDDLE TN AS MID LEVEL WIND MAX PASSES OVERHEAD. A FEW CLUSTERS OF ORGANIZED STORMS...PERHAPS A COUPLE OF SUPERCELLS...WITH HAIL AND WIND DAMAGE POTENTIAL APPEAR POSSIBLE. ACTIVITY FARTHER SWWD INTO THE LOWER MS VALLEY/NRN GULF COAST IS FORECAST TO REMAIN MORE ISOLATED GIVEN WEAKER LARGE SCALE SUPPORT. ...INTERIOR NORTHWEST ACROSS THE ROCKIES TO NRN PLAINS... WIDESPREAD CONVECTION IS FORECAST ACROSS PARTS OF THE GREAT BASIN AS DIURNAL HEATING COMBINES WITH A NUMBER OF SMALL SCALE PERTURBATIONS RIDING UP AND AROUND THE WRN/NRN FLANK OF THE UPPER RIDGE. ADDITIONAL ACTIVITY IS EXPECTED TO INCREASE EAST OF THE CONTINENTAL DIVIDE FROM NM ACROSS CO/WY/MT OWING TO RELATIVELY MOIST UPSLOPE FLOW IN VICINITY OF RESIDUAL FRONTAL BOUNDARY BACKED INTO THE HIGHER TERRAIN. MODELS APPEAR IN REASONABLE AGREEMENT THAT STRONGEST LARGE SCALE FORCING WILL DEVELOP EAST ACROSS THE CASCADES AS A PACIFIC SHORT WAVE TROUGH MOVES INLAND AND PROMOTES ANOTHER AREA OF STRONG TO SEVERE CONVECTIVE POTENTIAL FROM THE UPPER COLUMBIA RIVER VALLEY...EAST ACROSS WRN MT. OVERALL FORCING AND DEEP LAYER SHEAR WILL FAVOR SEVERE STORMS WITH HAIL AND WIND OVER ALL OF THESE AREAS WITH MORE PERSISTENT ACTIVITY PERHAPS CONSOLIDATING NEAR THE SHORT WAVE TROUGH FROM ORE/WA EWD ACROSS MT DURING THE AFTERNOON AND EVENING. OTHER STORMS/SUPERCELLS DEVELOPING ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS FROM NRN WY AND SERN MT TO THE SD BLACK HILLS ARE EXPECTED TO CONGEAL INTO AN MCS OR TWO THROUGH THE EVENING. IN ADDITION TO ISOLATED TORNADO THREAT WITH INITIAL DISCRETE CONVECTION...LARGE HAIL AND WIND POTENTIAL MAY PERSIST AS ACTIVITY DEVELOPS INTO STRENGTHENING WARM AIR ADVECTION REGIME FROM ERN MT INTO THE WRN DAKOTAS OVERNIGHT. ...SOUTHWEST... ANTICIPATED PLUME OF GREATER MID LEVEL MOISTURE STREAMING NWD ON THE WRN FLANK OF THE UPPER RIDGE...COUPLED WITH STRONG HEATING AND UPSLOPE FLOW ACROSS THE SOUTHWEST...WILL LIKELY SPUR SCATTERED TO NUMEROUS TSTMS. MODELS SUGGEST THAT SLIGHTLY STRONGER MID LEVEL FLOW ACROSS SRN AZ WILL CONTRIBUTE TO POCKETS OF GREATER DEEP LAYER SHEAR SUPPORTIVE OF UPDRAFT PERSISTENCE. ISOLATED TO WIDELY SCATTERED DAMAGING DOWNBURSTS...AND A FEW HAIL EVENTS...APPEAR POSSIBLE WITH THIS ACTIVITY THROUGH EVENING. ..CARBIN.. 06/06/2006  From swody2 at goshenarc.org Tue Jun 6 17:38:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 06 Jun 2006 13:38:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061736 SWODY2 SPC AC 061734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT TUE JUN 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY IN THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN INTERMOUNTAIN REGION EWD INTO THE NRN PLAINS... ...SYNOPSIS... MODELS INDICATE HIGH AMPLITUDE UPPER FLOW PATTERN WILL CONTINUE TOMORROW. IN THE EAST...A MEAN TROUGH WILL BE MAINTAINED AS A WELL-DEFINED VORTICITY CENTER CURRENTLY APPROACHING WRN LAKE SUPERIOR MOVES SEWD ACROSS THE GREAT LAKES TOWARD THE OH VALLEY...WHILE DOWNSTREAM UPPER LOW ALONG THE CAROLINA COAST LIFTS NWD TOWARD NEW ENGLAND. FARTHER WEST...MODELS SUGGEST SLOW PROGRESSION OF LARGE SCALE FEATURES AS THE WRN RIDGE AXIS SLOWLY SHIFTS EWD TOWARD THE HIGH PLAINS IN ADVANCE OF A SHORT WAVE TROUGH MOVING TOWARD THE PACIFIC NORTHWEST COAST. AT THE SURFACE...A WEAK LOW ASSOCIATED WITH THE GREAT LAKES UPPER SYSTEM WILL MOVE SEWD FROM MI INTO OH...WHILE WEAKENING FRONT MOVES SLOWLY SEWD REACHING A WRN OH/WRN TN/CENTRAL TX LINE DURING THE LATE AFTERNOON/EVENING. A SECOND FRONT WILL EXTEND FROM ONTARIO AND LAKE SUPERIOR WWD ACROSS SD INTO A LOW OVER NRN ID AREA...AND A PACIFIC COLD FRONT WILL MOVE INLAND ACROSS PARTS OF WA/ORE/ID/WRN MT DURING THE PERIOD. ...OH VALLEY INTO THE LOWER MS VALLEY... SEVERAL BANDS OF THUNDERSTORMS MAY BE ONGOING AT THE START OF THE PERIOD FROM LAKE MI/LOWER MI SWD INTO THE LOWER MS VALLEY. SCATTERED CONVECTION NEAR THE FRONT IS EXPECTED TO CONTINUE MOVING SLOWLY EWD/SEWD DURING THE DAY...WHICH WILL INHIBIT STRONG INSOLATION AND DESTABILIZATION DOWNSTREAM FROM ACTIVE AREAS OF STORMS. HOWEVER...THUNDERSTORMS MAY REDEVELOP OVER THE NRN PARTS OF THE RISK AREA IN THE WAKE OF THE MORNING THUNDERSTORMS AS DYNAMIC FORCING ASSOCIATED WITH THE UPPER VORTICITY OVERSPREADS THE FRONT AND REGION OF ENHANCED MOISTURE/INSTABILITY. THESE STORMS WILL ALSO BE LOCATED IN CLOSER PROXIMITY TO THE STRONGER NLY MID LEVEL WINDS/DEEP LAYER SHEAR...WHICH WILL ENHANCE CONVECTIVE ORGANIZATION AND INDICATE A THREAT FOR A FEW SEVERE STORMS TO DEVELOP. FARTHER SOUTH...INCREASINGLY DIFFLUENT FLOW ALOFT FAVORS DEVELOPMENT OF A FEW SEVERE THUNDERSTORMS OVER PARTS OF THE LOWER MS VALLEY. DAMAGING WIND GUSTS AND HAIL WILL BE THE PRIMARY THREATS ACROSS THESE REGIONS MAINLY DURING THE AFTERNOON AND EVENING HOURS. ...NRN INTERMOUNTAIN REGION... UPPER SHORT WAVE TROUGH NOW NEARING 137W IS FORECAST TO MOVE INLAND INTO THE PACIFIC NORTHWEST TOMORROW. SCATTERED THUNDERSTORMS DURING DAY 1 PERIOD MAY RESULT IN INCREASED MOISTURE AVAILABILITY ON WEDNESDAY IN ADVANCE OF THE APPROACHING COLD FRONT. PRE-EXISTING STEEP MID LEVEL LAPSE RATES WILL AID DEVELOPMENT OF UNSTABLE ENVIRONMENT WITH MLCAPE OF 1000-1500 J/KG. DYNAMIC FORCING ASSOCIATED WITH RIGHT ENTRANCE REGION OF UPPER LEVEL JET STREAK COUPLED WITH FRONTAL CONVERGENCE AND TERRAIN EFFECTS WILL RESULT IN SCATTERED THUNDERSTORMS DEVELOPING OVER PARTS OF ERN ORE/EXTREME SERN WA INTO NRN/CENTRAL ID AND WRN MT DURING THE LATE AFTERNOON THROUGH THE EVENING HOURS. DEEP LAYER SHEAR OF 30-40 KT IN THE LOWEST 6 KM WILL BE SUPPORTIVE OF A FEW SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL..DAMAGING WIND GUSTS..AND AN ISOLATED TORNADO OR TWO. ...NRN ROCKIES INTO NRN PLAINS... A LOW LEVEL MOIST AXIS IS FORECAST TO DEVELOP TOMORROW OVER PARTS OF SD/NRN WY AND MT AS ELY LOW LEVEL WINDS STRENGTHEN NORTH OF THE AFOREMENTIONED EAST/WEST NRN PLAINS FRONT. VERY STEEP LAPSE RATES WILL ENHANCE INSTABILITY...AND LOW LEVEL UPSLOPE WINDS WILL COMBINE WITH WEAK PERTURBATIONS ALONG THE NRN EDGE OF THE UPPER RIDGE TO AID IN DEVELOPMENT OF SCATTERED THUNDERSTORMS DURING THE LATE AFTERNOON AND EVENING. STRONG DIRECTIONAL SHEAR WITH HEIGHT WILL SUPPORT A FEW SEVERE STORMS. CONVECTIVE THREAT WILL CONTINUE OVER THE HIGH PLAINS DURING THE NIGHT AS THE SOUTHERLY LOW LEVEL JET INTENSIFIES OVER NEB/SD...ENHANCING LOW LEVEL WARM ADVECTION/CONVERGENCE ALONG/NORTH OF THE FRONT. ...SERN CA/AZ... MID LEVEL MOISTURE IS EXPECTED TO PERSIST ON THE WRN PERIPHERY OF THE UPPER RIDGE...WHERE STEEP LAPSE RATES AND DEEP WELL-MIXED LAYER WILL BE PRESENT. HIGH-BASED THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING AND SPREAD NWD/NWWD WITHIN BAND OF 25-30 KT SSELY MID LEVEL WINDS. THERE IS POTENTIAL FOR ISOLATED DAMAGING DOWNBURSTS AND POSSIBLY HAIL TO OCCUR WITH STRONGEST CELLS. ..WEISS.. 06/06/2006  From swody2 at goshenarc.org Wed Jun 7 06:15:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 07 Jun 2006 02:15:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070611 SWODY2 SPC AC 070610 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0110 AM CDT WED JUN 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN ROCKIES TO NRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SOUTHEAST COAST... ...SYNOPSIS... HIGH AMPLITUDE FLOW WILL REMAIN WELL ESTABLISHED OVER THE U.S. DURING THURSDAY AND FRIDAY AND CONSIST OF A BROAD DEEP LAYERED ANTICYCLONE SETTLING ACROSS THE SCNTRL CONUS...A RELATIVELY STRONG TROUGH ALONG THE EAST COAST...AND ANOTHER TROUGH DEVELOPING GRADUALLY INLAND FROM THE PACIFIC NORTHWEST. ONE OR MORE SUBTLE SHORT WAVE DISTURBANCES...ROUNDING THE WRN AND NRN PERIPHERY OF THE UPPER RIDGE...WILL LIKELY AID IN THE DEVELOPMENT AND ORGANIZATION OF DEEP CONVECTION FROM THE GREAT BASIN TO THE NRN PLAINS DURING THE DAY ONE PERIOD. THESE FEATURES...COUPLED WITH HEIGHT FALLS ASSOCIATED WITH THE HIGHER AMPLITUDE TROUGH MOVING ACROSS THE NORTHWEST...WILL SUBSTANTIALLY ERODE THE NWRN FLANK OF THE RIDGE CURRENTLY SITUATED ACROSS THE NRN ROCKIES. A BROAD BELT OF MODEST SWLY TO WLY DIFFLUENT FLOW ALOFT WILL EXTEND FROM THE NRN GREAT BASIN TO THE NRN PLAINS BY EARLY FRIDAY...AS CENTER OF UPPER HIGH CONSOLIDATES ACROSS THE SRN PLAINS. SHORT WAVE TROUGH AND ASSOCIATED WIND MAX CURRENTLY MOVING ACROSS THE GREAT LAKES REGION WILL CONTINUE SEWD WITH STRENGTHENING DIFFLUENT MID LEVEL FLOW SPREADING ACROSS THE NRN GULF AND SOUTHEAST COASTS THROUGH THURSDAY AFTERNOON. ...NRN ROCKIES TO NRN HIGH PLAINS... APPROACH OF PACIFIC TROUGH AND UPSTREAM AMPLIFICATION OF UPPER RIDGE ACROSS THE CANADIAN PRAIRIES WILL ENHANCE LOW LEVEL SELY/UPSLOPE FLOW ACROSS MT/WY ON THE SWRN PERIPHERY OF SURFACE HIGH CENTERED OVER SCNTRL CANADA. COUPLED WITH EXTENSIVE ZONE OF DIFFLUENT MID LEVEL FLOW FROM THE ROCKIES TO THE NRN/CNTRL HIGH PLAINS...A NW-SE ORIENTED BAND OF STRONG WARM AIR ADVECTION AND ELEVATED CONVECTION IS EXPECTED TO BE ONGOING BY EARLY THURSDAY FROM NERN MT...ACROSS THE DAKOTAS...TO IA. A WARM AND RELATIVELY MOIST AIR MASS IS EXPECTED TO DEVELOP IN THE WAKE OF THIS ACTIVITY...AND AHEAD OF STRENGTHENING LEE TROUGH AND SLOW MOVING COLD FRONT...FROM ID EWD ACROSS WRN/CNTRL MT...AND NRN/ERN WY. CONVECTION DURING THE DAY ONE PERIOD WILL FURTHER ENHANCE BOUNDARY LAYER MOISTURE ACROSS THESE AREAS WITH STEEPENING LAPSE RATES AND SURFACE HEATING CONTRIBUTING TO AREAS OF STRONG DESTABILIZATION BY AFTERNOON. STORMS WILL INITIATE ON THE HIGHER TERRAIN AND INCREASE IN COVERAGE AND INTENSITY AS GREATER INSTABILITY AND SHEAR IS REALIZED. SEVERAL CLUSTERS/LINES OF STORMS/SUPERCELLS WILL MOVE EWD/NEWD INTO THE EVENING WITH THE CHANCE FOR LARGE HAIL/HIGH WINDS AND PERHAPS A TORNADO OR TWO. ONE OR TWO SMALL CLUSTERS OF STORMS MAY PERSIST AND MOVE EAST INTO HOT AND DEEPLY MIXED BOUNDARY LAYER FROM ERN WY ACROSS WRN NEB AND SD DURING THE EVENING. LEE-LOW MAY FURTHER SUPPORT THE UPSCALE EVOLUTION INTO AN MCS WITH WIND/HAIL POTENTIAL SPREADING EAST DURING THE NIGHT. A SEPARATE AREA OF STRONG FORCING ON THE NOSE OF THE LOW LEVEL JET MAY PROMOTE STORM INITIATION ON THE EDGE OF THE CAP...FROM ERN DAKOTAS INTO MN/IA THROUGH EARLY FRIDAY. GIVEN POTENTIAL FOR VERY STEEP MID LEVEL LAPSE RATES AND STRENGTHENING SHEAR ACROSS THESE AREAS...A FEW HAIL EVENTS WILL BE POSSIBLE WITH THIS ACTIVITY. ...OH VALLEY TO SOUTHEAST/NRN GULF COAST... STRONGER FORCING AND SHEAR ACCOMPANYING SHORT WAVE DISTURBANCE WILL DEVELOP SEWD FROM THE OH VALLEY TO THE SRN APPALACHIANS AND ARRIVE OVER THE SOUTHEAST COINCIDENT WITH DAYTIME HEATING/DESTABILIZATION. ALTHOUGH LOW LEVEL MOISTURE IS NOT EXPECTED TO BE GREAT IN THE WAKE OF RECENT COOL OFFSHORE FLOW ASSOCIATED WITH PERSISTENT UPPER LOW...STEEPENING LAPSE RATES AND GREATER MOISTURE/INSTABILITY...ESPECIALLY NEARER THE COAST...COULD PROMOTE STRONG TO SEVERE STORMS. SOMEWHAT WEAKER LOW LEVEL FORCING/CONVERGENCE ON THE FRONT/WIND SHIFT...BUT POTENTIALLY STRONGER SHEAR AND ADEQUATE INSTABILITY...COULD LEAD TO A FEW ORGANIZED STORMS WITH HAIL AND WIND FROM GA WWD/SWWD ALONG THE NRN GULF COAST. ...SOUTHWEST ACROSS THE FOUR CORNERS... DEEP HEATING/MIXING AND MID LEVEL MOISTENING ON THE WRN FLANK OF UPPER RIDGE WILL AGAIN RESULT IN WIDESPREAD AFTERNOON TSTMS FROM THE SOUTHWEST ACROSS THE FOUR CORNERS TO THE FRONT RANGE AND HIGH PLAINS. GIVEN POCKETS OF LOCALLY STRONGER DEEP LAYER SHEAR...AND DRY SUBCLOUD/INVERTED-V PROFILES...A FEW STORMS COULD PRODUCE HAIL AND DOWNBURST WINDS. ..CARBIN.. 06/07/2006  From swody2 at goshenarc.org Fri Jun 9 06:02:02 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 02:02:02 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090559 SWODY2 SPC AC 090558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN MT TO THE TN VALLEY... ...SYNOPSIS... UPPER RIDGE WILL FLATTEN CONSIDERABLY DURING THE DAY2 PERIOD AS HEIGHTS FALL ACROSS THE NRN ROCKIES FORCING SEVERAL SHORTWAVE TROUGHS ACROSS THE NRN/CNTRL PLAINS INTO THE MS VALLEY REGION. THIS EVOLUTION WILL BECOME VERY FAVORABLE FOR MULTIPLE MCS-TYPE EPISODES FROM THE NRN HIGH PLAINS...SEWD INTO THE TN VALLEY. ...TN VALLEY... ONE SUCH MCS CLUSTER WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD FROM IA INTO IL. WNWLY STEERING CURRENTS WILL ALLOW THIS ACTIVITY TO SPREAD DOWNSTREAM ALONG EXISTING FRONTAL BOUNDARY INTO KY/TN WITH DAYTIME INTENSIFICATION POSSIBLE WITHIN 30-40KT DEEP LAYER SHEAR. UPSTREAM...SFC FRONT WILL SAG SWD IN WAKE OF EARLY MORNING MCS ACROSS KS...WHILE INTENSE HEATING ACROSS THE SRN HIGH PLAINS WILL ALLOW DRY LINE TO MIX EWD TO A POSITION FROM THE TX SOUTH PLAINS INTO SCNTRL KS. THIS BOUNDARY MAY PROVE SUFFICIENT IN GENERATING ISOLATED SEVERE...MAINLY DIURNAL...THUNDERSTORMS WHERE TEMPERATURE DEW POINT SPREADS WILL BE MAXIMIZED...APPROACHING 50F...ENHANCING DOWNBURST POTENTIAL. ...NRN ROCKIES/HIGH PLAINS... ANOTHER MORE SYNOPTICALLY EVIDENT REGION FOR ASCENT WILL OCCUR ACROSS THE NRN ROCKIES INTO THE HIGH PLAINS OF ERN WY. SFC RIDGING ACROSS THE NRN/CNTRL PLAINS WILL FORCE MODIFIED BOUNDARY LAYER MOISTURE WELL WEST AGAINST THE HIGHER TERRAIN OF WY INTO SRN MT. IT APPEARS THUNDERSTORMS WILL EASILY DEVELOP BY MID AFTERNOON ACROSS THIS REGION WITHIN EXIT REGION OF JET BENEATH COLD THERMAL TROUGH. VERTICAL SHEAR PROFILES WILL SUPPORT STORM ROTATION WITH STRONG VEERING WITH HEIGHT AND SUFFICIENT SPEED SHEAR FOR SUPERCELL DEVELOPMENT. A VERY ACTIVE CONVECTIVE AFTERNOON/EVENING IS POSSIBLE FROM SCNTRL MT INTO SERN WY BEFORE ACTIVITY MERGES INTO AN MCS OVER THE NEB PANHANDLE...SPREADING SEWD TOWARD THE CNTRL PLAINS DURING THE OVERNIGHT HOURS. IF SUFFICIENT LOW LEVEL MOISTURE CAN RETURN TO WY/NEB PANHANDLE IT APPEARS TO BE A FAVORABLE SETUP FOR POSSIBLE TORNADOES PRIOR TO MCS EVOLUTION. ..DARROW.. 06/09/2006  From swody2 at goshenarc.org Fri Jun 9 17:33:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 13:33:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091731 SWODY2 SPC AC 091729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN/CENTRAL ROCKIES EWD ACROSS THE CENTRAL PLAINS INTO PORTIONS OF THE MID MS/TN/LOWER OH VALLEYS... ...SYNOPSIS.. LARGE UPPER RIDGE...CURRENTLY LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY...WILL FLATTEN BY SATURDAY AS A SERIES OF SHORTWAVE TROUGHS EJECT NEWD FROM THE SWRN U.S. INTO THE PLAINS STATES. THIS WILL RESULT IN 30-50 KT WLY MID LEVEL FLOW TO EXTEND W TO E ACROSS THE CENTRAL CONUS. UNDER THIS STRONGER MID LEVEL FLOW...A QUASI-STATIONARY COLD FRONT IS FORECAST TO EXTEND FROM ERN WY/CO EWD ACROSS KS/MID MS VALLEY/LOWER OH VALLEY INTO NC BY LATE IN THE DAY. THIS PATTERN SHOULD SUPPORT SEVERAL MCS EPISODES TO SPREAD EWD...MAINLY ALONG AND NORTH OF THE FRONT...FROM THE ROCKIES/CENTRAL PLAINS ESEWD INTO THE LOWER OH VALLEY/TN VALLEY REGION. ...MID MS/LOWER OH/TN VALLEYS... A WEAKENING MCS IS LIKELY BE ONGOING AT THE START OF THE PERIOD IN IL. WEAK WARM ADVECTION IS EXPECTED TO MAINTAIN THIS CONVECTION AS WNWLY FLOW ALOFT PUSHES THIS SYSTEM INTO THE LOWER OH VALLEY/ERN TN VALLEY REGION DURING THE AFTERNOON. WITH HEATING...MLCAPES BETWEEN 1000-1500 J/KG AND 30-40 KT DEEP LAYER SHEAR MAY AID STORM INTENSIFICATION. WIND DAMAGE IS EXPECTED TO THE MAIN THREAT GIVEN THE 30-50 KT WNWLY WINDS THAT WILL BE LOCATED ABOVE THE BOUNDARY LAYER. STORMS ARE EXPECTED TO WEAKEN AS THEY CROSS THE APPALACHIANS AND ENCOUNTER A MORE STABLE ENVIRONMENT. ETA/GFS ARE BOTH SUGGESTIVE OF SHORTWAVE TROUGH MOVING INTO KS/OK LATE IN THE DAY. THIS WILL INCREASE THE LOW LEVEL JET/WARM ADVECTION NORTH OF THE FRONT ACROSS PORTIONS OF ERN KS/WRN MO. THE LIFT ASSOCIATED WITH THESE FEATURES SHOULD AID STORM INITIATION ACROSS PORTIONS OF KS/MO LATE IN THE DAY. ALTHOUGH FORECAST OF MID AND UPPER 60 DEWPOINTS WILL LIKELY BE CONFINED CLOSE TO THE SURFACE...STEEP MID LEVEL LAPSE RATES WILL LIKELY RESULT IN AT LEAST MODERATE INSTABILITY. STRENGTHENING...MOSTLY UNIDIRECTIONAL...WLY WINDS ABOVE THE BOUNDARY LAYER SHOULD RESULT IN 30-40 KT OF DEEP LAYER SHEAR. THE LARGE SCALE LIFTING COMBINED WITH THE SHEAR AND DEGREE OF INSTABILITY SHOULD RESULT IN SEVERE STORMS DEVELOPING IN ERN KS/WRN MO LATE IN THE DAY. THE UNIDIRECTIONAL FLOW ALOFT SHOULD HELP TO CONSOLIDATE UPDRAFTS INTO AND MCS WITH THE SYSTEM MOVING ESEWD OVERNIGHT INTO THE LOWER OH VALLEY. ...NRN ROCKIES/HIGH PLAINS... MODELS SUGGEST SHORTWAVE TROUGH AND 50 KT JET MAX WILL MOVE EWD INTO THE REGION...WHERE ELY UPSLOPE FLOW WILL BE MOISTENING BOUNDARY LAYER. THE COMBINATION OF LARGE SCALE LIFTING AND UPSLOPE FLOW SHOULD RESULT IN NUMEROUS THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN FROM MT SWD INTO NRN CO. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS DUE TO STRONG VEERING WIND PROFILES AND 40-50 KT MID LEVEL WINDS. ALTHOUGH THE SHEAR AND INSTABILITY MAY SUPPORT A COUPLE OF TORNADOES...THE ACTIVITY IS EXPECTED TO MERGE INTO A FEW COMPLEXES AND THEN MOVE SEWD INTO THE PLAINS WITH HAIL/WIND THE MAIN THREATS. ..SRN PLAINS.... MID/HIGH LEVEL TROPICAL MOISTURE FROM THE ITCZ IS EXPECTED TO STREAM NEWD FROM MEXICO ACROSS TX INTO WRN OK/SRN KS. INTENSE HEATING SHOULD HELP TO CREATE DRY ADIABATIC LAPSE RATES FROM THE SURFACE TO THE LFC...AROUND 10 KFT...WHICH SHOULD AID IN HIGH BASE CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THE DEEP WELL MIXED BOUNDARY LAYER MAY BE SUFFICIENT IN GENERATING ISOLATED SEVERE WIND GUSTS BETWEEN 21-03Z. ..IMY.. 06/09/2006  From swody2 at goshenarc.org Fri Jun 9 17:41:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 13:41:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091739 SWODY2 SPC AC 091738 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 PM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN/CENTRAL ROCKIES EWD ACROSS THE CENTRAL PLAINS INTO PORTIONS OF THE MID MS/TN/LOWER OH VALLEYS... ...SYNOPSIS.. LARGE UPPER RIDGE...CURRENTLY LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY...WILL FLATTEN BY SATURDAY AS A SERIES OF SHORTWAVE TROUGHS EJECT NEWD FROM THE SWRN U.S. INTO THE PLAINS STATES. THIS WILL RESULT IN 30-50 KT WLY MID LEVEL FLOW TO EXTEND W TO E ACROSS THE CENTRAL CONUS. UNDER THIS STRONGER MID LEVEL FLOW...A QUASI-STATIONARY COLD FRONT IS FORECAST TO EXTEND FROM ERN WY/CO EWD ACROSS KS/MID MS VALLEY/LOWER OH VALLEY INTO NC BY LATE IN THE DAY. THIS PATTERN SHOULD SUPPORT SEVERAL MCS EPISODES TO SPREAD EWD...MAINLY ALONG AND NORTH OF THE FRONT...FROM THE ROCKIES/CENTRAL PLAINS ESEWD INTO THE LOWER OH VALLEY/TN VALLEY REGION. ...MID MS/LOWER OH/TN VALLEYS... A WEAKENING MCS IS LIKELY BE ONGOING AT THE START OF THE PERIOD IN IL. WEAK WARM ADVECTION IS EXPECTED TO MAINTAIN THIS CONVECTION AS WNWLY FLOW ALOFT PUSHES THIS SYSTEM INTO THE LOWER OH VALLEY/ERN TN VALLEY REGION DURING THE AFTERNOON. WITH HEATING...MLCAPES BETWEEN 1000-1500 J/KG AND 30-40 KT DEEP LAYER SHEAR MAY AID STORM INTENSIFICATION. WIND DAMAGE IS EXPECTED TO THE MAIN THREAT GIVEN THE 30-50 KT WNWLY WINDS THAT WILL BE LOCATED ABOVE THE BOUNDARY LAYER. STORMS ARE EXPECTED TO WEAKEN AS THEY CROSS THE APPALACHIANS AND ENCOUNTER A MORE STABLE ENVIRONMENT. ETA/GFS ARE BOTH SUGGESTIVE OF SHORTWAVE TROUGH MOVING INTO KS/OK LATE IN THE DAY. THIS WILL INCREASE THE LOW LEVEL JET/WARM ADVECTION NORTH OF THE FRONT ACROSS PORTIONS OF ERN KS/WRN MO. THE LIFT ASSOCIATED WITH THESE FEATURES SHOULD AID STORM INITIATION ACROSS PORTIONS OF KS/MO LATE IN THE DAY. ALTHOUGH FORECAST OF MID AND UPPER 60 DEWPOINTS WILL LIKELY BE CONFINED CLOSE TO THE SURFACE...STEEP MID LEVEL LAPSE RATES WILL LIKELY RESULT IN AT LEAST MODERATE INSTABILITY. STRENGTHENING...MOSTLY UNIDIRECTIONAL...WLY WINDS ABOVE THE BOUNDARY LAYER SHOULD RESULT IN 30-40 KT OF DEEP LAYER SHEAR. THE LARGE SCALE LIFTING COMBINED WITH THE SHEAR AND DEGREE OF INSTABILITY SHOULD RESULT IN SEVERE STORMS DEVELOPING IN ERN KS/WRN MO LATE IN THE DAY. THE UNIDIRECTIONAL FLOW ALOFT SHOULD HELP TO CONSOLIDATE UPDRAFTS INTO AND MCS WITH THE SYSTEM MOVING ESEWD OVERNIGHT INTO THE LOWER OH VALLEY. ...NRN ROCKIES/HIGH PLAINS... MODELS SUGGEST SHORTWAVE TROUGH AND 50 KT JET MAX WILL MOVE EWD INTO THE REGION...WHERE ELY UPSLOPE FLOW WILL BE MOISTENING BOUNDARY LAYER. THE COMBINATION OF LARGE SCALE LIFTING AND UPSLOPE FLOW SHOULD RESULT IN NUMEROUS THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN FROM MT SWD INTO NRN CO. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS DUE TO STRONG VEERING WIND PROFILES AND 40-50 KT MID LEVEL WINDS. ALTHOUGH THE SHEAR AND INSTABILITY MAY SUPPORT A COUPLE OF TORNADOES...THE ACTIVITY IS EXPECTED TO MERGE INTO A FEW COMPLEXES AND THEN MOVE SEWD INTO THE PLAINS WITH HAIL/WIND THE MAIN THREATS. ..SRN PLAINS.... MID/HIGH LEVEL TROPICAL MOISTURE FROM THE ITCZ IS EXPECTED TO STREAM NEWD FROM MEXICO ACROSS TX INTO WRN OK/SRN KS. INTENSE HEATING SHOULD HELP TO CREATE DRY ADIABATIC LAPSE RATES FROM THE SURFACE TO THE LFC...AROUND 10 KFT...WHICH SHOULD AID IN HIGH BASE CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THE DEEP WELL MIXED BOUNDARY LAYER MAY BE SUFFICIENT IN GENERATING ISOLATED SEVERE WIND GUSTS BETWEEN 21-03Z. ..IMY.. 06/09/2006  From swody2 at goshenarc.org Sat Jun 10 05:46:30 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 10 Jun 2006 01:46:30 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100544 SWODY2 SPC AC 100543 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT SAT JUN 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MO TO THE CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN CO TO SERN MT... ...MO TO CAROLINAS... LARGE SCALE HEIGHT RISES ACROSS THE PLAINS DURING THE DAY2 PERIOD WILL LIMIT STRONG THUNDERSTORM DEVELOPMENT TO THAT REGION FORCED BY LOW LEVEL WARM ADVECTION ACROSS THE MID MS/TN VALLEY...CAROLINAS...AND UPSLOPE REGIONS OF THE HIGH PLAINS. IT APPEARS AN MCS WILL BE ONGOING EARLY IN THE PERIOD OVER MO AIDED BY FOCUSED LLJ THAT SHOULD VEER AND WEAKEN SLIGHTLY DURING THE DAY OVER THE TN VALLEY. THIS MCS ACTIVITY SHOULD PROPAGATE ESEWD...BECOMING REJUVENATED DURING THE DAY...ALONG FRONTAL ZONE THAT WILL PROVE MODERATELY UNSTABLE...DRAPED FROM MO ALONG THE KY/TN BORDER INTO THE CAROLINAS. THERMODYNAMIC PROFILES AND VERTICAL SHEAR SUGGEST POSSIBLE LONG-LIVED SEVERE THUNDERSTORM CLUSTERS WITH DAMAGING WINDS WHERE CONVECTION CAN INTERACT WITH WARM SECTOR BOUNDARY LAYER INSTABILITY. FRONTAL ZONE ACROSS NC WILL LIKELY BE ANOTHER ACTIVE ZONE FOR DAYTIME THUNDERSTORM DEVELOPMENT. STORM ORGANIZATION IS LIKELY ALONG SFC WIND SHIFT WHERE WNWLY FLOW AT MID LEVELS WILL LIKELY EXCEED 35-40KT. ...CNTRL/NRN HIGH PLAINS... WELL ENTRENCHED SFC RIDGE OVER THE PLAINS WILL MAINTAIN ELY COMPONENT TO BOUNDARY LAYER FLOW ACROSS THE HIGH PLAINS INTO THE EAST SLOPES OF THE MOUNTAINS FROM CO...NWD INTO SRN MT. DESPITE RISING HEIGHTS ALOFT...STRONG HEATING COMBINED WITH LOW LEVEL CONVERGENT UPSLOPE FLOW SHOULD GENERATE SCATTERED THUNDERSTORMS BY MID-LATE AFTERNOON. DEEP VEERING PROFILES AND MODEST VERTICAL SHEAR CERTAINLY SUGGEST SUPERCELLS ARE POSSIBLE...AT LEAST INITIALLY IN STORM EVOLUTION. SLOW ESEWD PROPAGATIONAL COMPONENT WILL LIMIT MAIN SEVERE THREAT TO THE HIGH PLAINS REGION. LARGE HAIL AND ISOLATED TORNADOES MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/10/2006  From swody2 at goshenarc.org Sat Jun 10 17:30:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 10 Jun 2006 13:30:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101727 SWODY2 SPC AC 101726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT JUN 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN WY SEWD INTO THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS SERN MO EWD TO THE CAROLINAS... ...SYNOPSIS... BELT OF 30-40KT WLY MID LEVEL FLOW...CURRENTLY LOCATED W-E ACROSS THE CENTRAL CONUS...WILL SHIFT NWD INTO THE NRN ROCKIES/PLAINS AS THE UPPER RIDGE BUILDS NWD ACROSS THE ROCKIES/PLAINS REGION. THIS WILL RESULT IN AMPLIFICATION OF UPPER TROUGHS ACROSS THE WRN AND ERN CONUS. QUASI-STATIONARY FRONT IS FORECAST TO EXTEND ALONG THE FOOTHILLS ON WY/CO EWD THROUGH NRN OK INTO THE TN VALLEY AND THE CAROLINAS THROUGH MOST OF THE PERIOD. ...SERN MO EWD TO THE CAROLINAS... A WEAKENING MCS IS EXPECTED TO BE ONGOING EARLY IN THE PERIOD ACROSS PORTIONS OF MO/IL AS LOW LEVEL JET WEAKENS AND VEERS. ONCE THIS COMPLEX WEAKENS OR PERHAPS EVEN DISSIPATES...CONVECTIVE INITIATION ACROSS THIS REGION IS SOMEWHAT UNCERTAIN AS HEIGHTS RISE SLIGHTLY AND LOW LEVEL WARM ADVECTION WEAKENS AS 20-25 KT WLY WINDS BECOME PARALLEL TO THE SURFACE BOUNDARY. STRONG HEATING MAY AID STORM INITIATION NEAR THE FRONT AND/OR FROM REMNANTS OF EARLIER MCS ACTIVITY. STORMS THAT DEVELOP WILL HAVE FAVORABLE INSTABILITY AND VERTICAL SHEAR TO PRODUCE DAMAGING WINDS AND SOME MARGINALLY SEVERE HAIL. ...ERN WY SEWD INTO THE CENTRAL HIGH PLAINS... LARGE SURFACE HIGH...LOCATED OVER THE GREATS LAKE AREA...WILL MAINTAIN DEEP ELY COMPONENT TO THE BOUNDARY LAYER FLOW ACROSS THE HIGH PLAINS AND ERN SLOPES OF ERN CO/WY. DESPITE RISING HEIGHTS ALOFT...STRONG HEATING COMBINED WITH CONVERGENT UPSLOPE FLOW AND MOISTENING BOUNDARY LAYER SHOULD AID IN THUNDERSTORMS DEVELOPING BY MID-LATE AFTERNOON. MID LEVEL FLOW ALOFT WILL BE ABOUT 15-20 KT WEAKER THAN TODAY...BUT STRONGLY VEERING WIND PROFILES AND 30 KT MID LEVEL WLY WINDS RESULT IN STRONGLY VEERING PROFILES...WHICH WOULD BE FAVORABLE FOR SUPERCELLS. THE STORMS SHOULD MOVE SEWD TOWARD THE STRONGER INSTABILITY...LIMITING THE MAIN SEVERE WEATHER THREAT TO THE HIGH PLAINS REGION. ALTHOUGH AN ISOLATED TORNADO IS POSSIBLE SHORTLY AFTER THE STORMS FIRST DEVELOP...THE SHEAR AND STEEP LAPSE RATES SUGGEST SEVERE HAIL SHOULD BE THE MAIN THREAT. ...FL PENINSULA... TROPICAL DEPRESSION #1 IS FORECAST TO BE LOCATED IN THE SERN GULF OF MEXICO DURING THIS PERIOD...WITH HIGH CHANCES OF THUNDERSTORMS ACROSS THE FL PENINSULA. KEY WEST VAD WIND PROFILE IS ALREADY SHOWING SELY WINDS AT 30-35 KT FROM THE SURFACE TO 4 KM AND DEPENDING ON THE ACTUAL TRACK AND STRENGTHENING OF THE SYSTEM... WINDS MAY STRENGTHEN ENOUGH FOR AN ISOLATED TORNADO THREAT WITHIN THE OUTER BANDS OF THE SYSTEM. REFER TO THE NATIONAL HURRICANE CENTER FOR THE LATEST ADVISORIES AND FORECASTS ON THIS TROPICAL SYSTEM. ..IMY.. 06/10/2006  From swody2 at goshenarc.org Sun Jun 11 05:41:57 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 11 Jun 2006 01:41:57 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110539 SWODY2 SPC AC 110538 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CDT SUN JUN 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN INTER MOUNTAIN REGION INTO MT... ...SERN U.S... LATEST MODEL GUIDANCE SUGGEST TROPICAL SYSTEM DEVELOPING OVER THE SRN GULF OF MEXICO WILL BE DRAWN INTO THE BASE OF LONG WAVE TROUGH OVER THE ERN U.S. AND LIFT NEWD TOWARD THE FL PENINSULA EARLY IN THE DAY2 PERIOD. GUIDANCE FROM THE HURRICANE CENTER INDICATES THIS FEATURE WILL GRADUALLY INCREASE AND POSSIBLY BECOME A TROPICAL STORM BEFORE LANDFALL. THIS EVOLUTION WILL RESULT IN INCREASINGLY SHEARED PROFILES ALONG THE FL PENINSULA AS SYSTEM ACCELERATES TOWARD THE WRN ATLANTIC...OFF THE CAROLINA COAST BY TUE MORNING. ISOLATED TORNADOES WILL BECOME MORE LIKELY TO THE EAST OF THE LOW TRACK AS CIRCULATION BECOMES ABSORBED IN THE BASE OF LONG WAVE TROUGH. ...NRN INTER MOUNTAIN REGION/NRN ROCKIES...HIGH PLAINS... SIGNIFICANT HEIGHT RISES WILL DEVELOP ACROSS MUCH OF THE WRN U.S. THIS PERIOD AS RIDGE BUILDS NWD ACROSS THE ROCKIES INTO ALBERTA/SASKATCHEWAN. LONG WAVE TROUGH ALONG THE PACIFIC COAST WILL PROGRESS LITTLE INLAND...ALTHOUGH AT LEAST ONE SIGNIFICANT MID LEVEL SPEED MAX WILL SPREAD INTO NV LATE IN THE PERIOD. A BELT OF MODERATE MID-HIGH LEVEL MERIDIONAL FLOW WILL BE MAINTAINED FROM SRN CANADA INTO ERN WA/ORE DURING THE PERIOD PROVIDING VERTICAL SHEAR NECESSARY FOR SUSTAINING ROBUST CONVECTIVE DEVELOPMENT. IN THE ABSENCE OF MEANINGFUL LARGE SCALE ASCENT...IT APPEARS STRONG HEATING/OROGRAPHIC LIFTING WILL PROVE BENEFICIAL IN GENERATING THUNDERSTORMS DURING THE AFTERNOON ACROSS THE NWRN U.S. MONDAY. CONVECTION SHOULD DEVELOP LATE...BUT LIKELY INCREASE IN INTENSITY OVER ERN ORE/WA ALONG FRONTAL ZONE WHERE SUPERCELL STRUCTURES ARE POSSIBLE. OTHER STORMS ARE POSSIBLE ACROSS WRN MT BY LATE AFTERNOON WHERE SIGNIFICANT ELY LOW LEVEL FLOW IS EXPECTED TO FORCE BOUNDARY LAYER MOISTURE DEEP INTO THE HIGHER ELEVATIONS. VERTICAL SHEAR PROFILES STRONGLY SUGGEST ANY THUNDERSTORM CLUSTERS THAT EVOLVE ACROSS WRN MT WILL BE MORE THAN ADEQUATELY SHEARED FOR SUPERCELL STRUCTURES. THIS ACTIVITY WOULD THEN MOVE NEWD TOWARD THE PLAINS WHERE STRONG LOW LEVEL SHEAR WILL ENHANCE INFLOW/FORWARD PROPAGATIONAL COMPONENT. MCS MAY EVOLVE ACROSS NWRN/NRN MT LATE IN THE PERIOD BEFORE SPREADING INTO SWRN SASKATCHEWAN AFTER MIDNIGHT. ..DARROW.. 06/11/2006  From swody2 at goshenarc.org Sun Jun 11 17:24:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 11 Jun 2006 13:24:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 111722 SWODY2 SPC AC 111721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SUN JUN 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE INTERIOR PAC NW INTO WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS SERN CO... ...THERE IS A SLGT RISK OF SVR TSTMS FL PENINSULA... ...SYNOPSIS... HIGHLY AMPLIFIED PATTERN IN WRN U.S. AS TROUGH REMAINS JUST OFF W COAST AND STRONG RIDGE BUILDS NWD OVER ROCKIES. TROUGH POSITION REMAINS ERN U.S. AS ONE S/WV TRACKS EWD TO SRN ENGLAND AND NEXT IN LINE DROPS SEWD FROM MANITOBA REACHING WRN GREAT LAKES BY 12Z TUE. NEWLY FORMED T.S. ALBERTO SERN GULF IS PROGGED TO HEAD FOR THE NERN GULF COAST BY LATE DY2. MODEL GUIDANCE SUGGEST THERE IS CONSIDERABLE UNCERTAINTY ABOUT THE FUTURE TRACK AND INTENSITY AT THE SURFACE HIGH PRESSURE GENERALLY OVER NCENTRAL U.S WHICH WILL MAINTAIN E/SELY FLOW CENTRAL AND NORTHERN HIGH PLAINS AND ACROSS NRN ROCKIES. ...PAC NW... WITH SUCH AMPLITUDE IN THE TROUGH/RIDGE WRN U.S...ONLY MINOR IMPULSES EXPECTED TO MOVE INLAND THIS FORECAST PERIOD. HOWEVER WITH A STRONG MID/UPPER LEVEL JET MAX MOVING FROM CENTRAL CA TOWARD ERN WA...DEEP LAYER SHEAR WILL BE QUITE FAVORABLE FOR ORGANIZED THUNDERSTORM POTENTIAL INTERIOR PAC NW...DEPENDENT ON THE QUALITY OF AIR MASS. WITH THE LOW LEVEL ELYS FROM NRN HIGH PLAINS FORECASTED TO EXTEND WWD ACROSS MT INTO NRN ID/ERN WA...MOISTURE ALONG WITH ENHANCED LOW LEVEL SHEAR SUFFICIENT FOR SUPERCELL POTENTIAL. HEATING COUPLED WITH TERRAIN EFFECTS SHOULD LEAD TO STORM DEVELOPMENT BY MID/LATE AFTERNOON ERN WA/NERN OR/NRN ID. GREATEST UNCERTAINTY IS DEGREE OF INSTABILITY...HOWEVER WITH LAPSE RATES AROUND 8C/KM AND 50-60 KT OF DEEP LAYER SHEAR...SEVERE STORMS ARE LIKELY WITH POTENTIAL FOR SUPERCELLS. SEVERE THREAT EXPECTED TO REMAIN PRIMARILY W OF DIVIDE GIVEN THE POSITION OF UPPER RIDGE OVER ROCKIES. EXCEPTION WOULD BE IF ANY MCS THAT EVOLVES OUT OF PAC NW STORMS COULD TRACK NEWD ACROSS NCENTRAL MT OVERNIGHT. ...FL PENINSULA... HAVE CONFINED THREAT FOR SEVERE THUNDERSTORMS ASSOCIATED WITH T.S. ALBERTO TO JUST FL PENINSULA DUE TO UNCERTAINTY IN BOTH TRACK AND SPEED OF STORM. TROPICAL AIR EXPECTED TO OVERSPREAD FL PENINSULA BY MON AND WITH MDTLY SHEARED ENVIRONMENT ON E SIDE OF ALBERTO...THREAT IS MAINTAINED FOR A SEVERE THREAT...BOTH ISOLATED TORNADOES AND WIND DAMAGE. ...ERN CO... E/SELY UPSLOPE FLOW WILL CONTINUE TO TRANSPORT SUFFICIENT MOISTURE FOR THUNDERSTORMS INTO ERN CO. WITH STRONG HEATING AND VERY STEEP LAPSE RATES...MLCAPES BY MID AFTERNOON WILL RANGE UPWARD FROM 1500 J/KG ALONG FRONT RANGE TO 2500 J/KG SERN PLAINS OF CO. DEEP LAYER SHEAR OF 30-40KT EXPECTED TO SUPPORT SUPERCELLS AS STORMS THAT DEVELOP OVER HIGHER TERRAIN PROPAGATE E/SEWD INTO PLAINS BY LATE AFTERNOON/EVENING. LARGE HAIL AND DOWNBURSTS PRIMARY CONCERN AS THE EXPECTED HIGH BASES WILL LIMIT TORNADO THREAT. ..HALES.. 06/11/2006  From swody2 at goshenarc.org Mon Jun 12 05:59:43 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 01:59:43 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120557 SWODY2 SPC AC 120556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR NW INTO ERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S.... ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... LARGE SCALE PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS AS UPPER RIDGE HOLDS FROM THE SRN ROCKIES INTO SASKATCHEWAN. MODEST MID-HIGH LEVEL MERIDIONAL FLOW ACROSS THE GREAT BASIN INTO WRN MT WILL PERSIST...AND INCREASE LATE IN THE PERIOD AS SPEED MAX LIFTS NEWD TOWARD ERN ID. ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE DAY...ESPECIALLY IN OROGRAPHICALLY FAVORED AREAS. THIS ACTIVITY WILL BE STRONGLY SHEARED...AND SUFFICIENTLY BUOYANT FOR POTENTIAL SUPERCELL DEVELOPMENT. DEEP ELY BOUNDARY LAYER FLOW ACROSS THE PLAINS OF MT WILL LIMIT LOW LEVEL HEATING AND SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL STORM ALBERTO IS EXPECTED TO EJECT NEWD ACROSS THE NRN FL PENINSULA DURING THE DAY2 PERIOD. THIS TRACK WILL OBVIOUSLY ALLOW SHEAR PROFILES TO INCREASE MARKEDLY ACROSS MUCH OF THE FL PENINSULA...ENHANCING THE POSSIBILITY FOR A FEW TORNADOES. ..DARROW.. 06/12/2006  From swody2 at goshenarc.org Mon Jun 12 06:07:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 02:07:40 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120605 SWODY2 SPC AC 120604 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0104 AM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR NW INTO ERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S.... ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... LARGE SCALE PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS AS UPPER RIDGE HOLDS FROM THE SRN ROCKIES INTO SASKATCHEWAN. MODEST MID-HIGH LEVEL MERIDIONAL FLOW ACROSS THE GREAT BASIN INTO WRN MT WILL PERSIST...AND INCREASE LATE IN THE PERIOD AS SPEED MAX LIFTS NEWD TOWARD ERN ID. ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE DAY...ESPECIALLY IN OROGRAPHICALLY FAVORED AREAS. THIS ACTIVITY WILL BE STRONGLY SHEARED...AND SUFFICIENTLY BUOYANT FOR POTENTIAL SUPERCELL DEVELOPMENT. DEEP ELY BOUNDARY LAYER FLOW ACROSS THE PLAINS OF MT WILL LIMIT LOW LEVEL HEATING AND SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL STORM ALBERTO IS EXPECTED TO EJECT NEWD ACROSS THE NRN FL PENINSULA DURING THE DAY2 PERIOD. THIS TRACK WILL OBVIOUSLY ALLOW SHEAR PROFILES TO INCREASE MARKEDLY ACROSS MUCH OF THE FL PENINSULA...ENHANCING THE POSSIBILITY FOR A FEW TORNADOES. ..DARROW.. 06/12/2006  From swody2 at goshenarc.org Mon Jun 12 17:26:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 13:26:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121722 SWODY2 SPC AC 121721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR PAC NW INTO ERN MT...... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S...... ...SYNOPTIC DISCUSSION... LARGE SCALE FEATURES WILL MAKE ONLY SLOW EWD PROGRESS TUE. WHILE THE CIRCULATION CENTER OF NWRN U.S. TROUGH REMAINS NEAR THE MOUTH OF THE COLUMBIA RIVER...A STRONG MID/UPPER SPEED MAX ROTATES NEWD ACROSS INTERMOUNTAIN REGION REACHING NRN ROCKIES BY LATER TUE NIGHT. DOWNSTREAM RIDGE EXTENDS NWD FROM NM UPPER HIGH TO SASKATCHEWAN SHIFTING INTO HIGH PLAINS BY 12Z WED. ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...THE TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE AFTERNOON AHEAD OF THE COLD FRONT FROM NWRN MT AT LEAST AS FAR S AS SWRN ID. THIS ACTIVITY WILL BE STRONGLY SHEARED. LIMITATION...PARTICULARLY SRN ID AREA WILL BE MOISTURE/INSTABILITY. ACROSS MT DEEP ELY BOUNDARY LAYER FLOW WILL PROVIDE SIGNIFICANTLY GREATER MOISTURE AND POTENTIAL INSTABILITY. STORM MODE SRN PORTION OF SLIGHT SHOULD BE HIGH BASED MULTI-CELLS LIMITING POTENTIAL TO WIND DAMAGE AND MARGINAL HAIL. WITH POTENTIALLY SIGNIFICANTLY GREATER INSTABILITY AND VEERING LOW LEVEL SHEAR ENVIRONMENT WRN MT...SUPERCELLS WILL BE POSSIBLE. THIS WILL ENHANCE... PARTICULARLY LARGE HAIL THREAT WITH POSSIBLE ISOLATED TORNADOES. ACROSS THE PLAINS OF MT WITH MORE LIMITED LOW LEVEL HEATING...SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL AIR WILL CONTINUE SPREADING NWD AS T.S. ALBERTO HEADS TOWARD LANDFALL NERN GULF COAST. REF NHC PRODUCTS FOR TRACK AND LANDFALL TIMING. FAVORABLE SHEAR WILL MAINTAIN POTENTIAL FOR TORNADIC SUPERCELLS AHEAD OF THE TRACK OF ALBERTO. ..HALES.. 06/12/2006  From swody2 at goshenarc.org Tue Jun 13 05:59:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 13 Jun 2006 01:59:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130556 SWODY2 SPC AC 130555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE JUN 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...NRN ROCKIES/NRN PLAINS... UPPER RIDGE WILL BE SHUNTED EAST ACROSS THE NRN HIGH PLAINS DURING THE DAY2 PERIOD AS STRONGER FLOW TRANSLATES ACROSS THE GREAT BASIN INTO ERN MT...ON DOWNSTREAM SIDE OF UPPER TROUGH. SWLY FLOW ACROSS THE HIGHER TERRAIN OF THE NRN...AND ESPECIALLY THE CENTRAL ROCKIES...WILL GENERATE SUBSTANTIAL CAPPING ATOP MODESTLY MOIST BOUNDARY LAYER. WHILE WARM SECTOR THUNDERSTORMS WILL STRUGGLE TO DEVELOP SOUTH OF I-70 OVER NEB...IT APPEARS STRONG HEATING IN THE LEE OF THE NRN ROCKIES WILL WEAKEN CAP ALLOWING SFC PARCELS TO REACH THEIR LFC. THIS APPEARS LIKELY ACROSS MT...SEWD TO POSSIBLY NEAR THE BLACK HILLS REGION OF WRN SD. LATEST THINKING IS SEVERE THUNDERSTORMS...INITIALLY SUPERCELLULAR...WILL EVOLVE AHEAD OF SFC LOW OVER SERN MT THEN SPREAD ENEWD TOWARD WRN ND...DEVELOPING SWD INTO WRN SD AS THE EVENING PROGRESSES. INCREASING LLJ AFTER DARK WILL MOST LIKELY AID MCS DEVELOPMENT AS THUNDERSTORM CLUSTERS SPREAD INTO THE NRN PLAINS. HIGH TEMP/DEW POINT SPREADS MAY SUPPORT DAMAGING WINDS WITH BOW ECHO-TYPE STRUCTURES...IN ADDITION TO LARGE HAIL. ...COASTAL CAROLINAS... ALBERTO IS EXPECTED TO LIFT NEWD ALONG THE SC/NC COAST DURING THE DAY2 PERIOD. STRONGER SHEAR MORE FAVORABLE FOR SUPERCELLS SHOULD HOLD JUST OFFSHORE...ALTHOUGH UNCERTAINTY IN TRACK WILL REQUIRE AT LEAST LOW PROBABILITIES FOR ISOLATED TORNADOES NEAR THE REMNANT CIRCULATION. ..DARROW.. 06/13/2006  From swody2 at goshenarc.org Tue Jun 13 17:39:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 13 Jun 2006 13:39:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131737 SWODY2 SPC AC 131735 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1235 PM CDT TUE JUN 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN ROCKIES TO NRN PLAINS... ...SYNOPSIS... STRONGLY AMPLIFIED BUT RELATIVELY PROGRESSIVE UPPER FLOW WILL PERSIST ACROSS THE CONUS THROUGH MIDWEEK. AN IMPULSE ROUNDING THE BASE OF THE ELONGATED WEST COAST TROUGH IS FORECAST TO PIVOT NEWD AND PRODUCE MODERATE HEIGHT FALLS FROM THE NRN GREAT BASIN TO THE NRN HIGH PLAINS INTO EARLY THURSDAY. MEANWHILE...UPPER RIDGE CURRENTLY SITUATED ACROSS THESE AREAS WILL SHIFT EWD OVER THE PLAINS STATES THROUGH THE PERIOD...AND EXTEND NWD INTO SCNTRL CANADA. CIRCULATION ASSOCIATED WITH T.D. ALBERTO WILL BECOME INCREASINGLY ABSORBED BY THE WLYS WHICH WILL ACT TO ACCELERATE THE REMAINS OF THE TROPICAL SYSTEM NEWD ACROSS THE CAROLINAS EARLY IN THE PERIOD. THIS WILL OCCUR AHEAD OF SHORT WAVE TROUGHING DEVELOPING SEWD ACROSS THE OH VALLEY AND NORTHEAST AND CONTRIBUTING TO THE AMPLIFICATION OF THE MEAN UPPER TROUGH COVERING THE ERN U.S. ...NRN ROCKIES/NRN PLAINS... POTENT LARGE SCALE FORCING FOR ASCENT WILL ACCOMPANY THE IMPULSE EJECTING NEWD FROM THE NRN GREAT BASIN EARLY IN THE DAY. THIS WILL LIKELY SUSTAIN TSTMS ACROSS THE HIGHER TERRAIN THROUGH THE MORNING...WITH THIS ACTIVITY SPREADING ACROSS THE CONTINENTAL DIVIDE AND INTO CNTRL MT BY AFTERNOON. SHARPENING LEE-TROUGH WILL ENHANCE UPSLOPE FLOW AND ACT TO FOCUS GREATER LOW LEVEL MOISTURE BENEATH THE STRONG CAP FROM CNTRL MT/NRN WY EWD TO THE NRN HIGH PLAINS WHERE STRONG DESTABILIZATION WILL TAKE PLACE. AS DIFFLUENT MID LEVEL FLOW AND HEIGHT FALLS SPREAD ATOP THE CAPPED INSTABILITY AXIS THROUGH LATE AFTERNOON...OROGRAPHIC AND DIABATIC FORCING WILL CONTRIBUTE TO WEAKENING THE CAP SUFFICIENTLY FOR STORM INTENSIFICATION FROM NRN WY ACROSS THE ERN HALF OF MT. DIRECTIONAL AND VERTICAL SPEED SHEAR FORECAST ACROSS THE REGION WILL PROVE MORE THAN ADEQUATE FOR SUPERCELLS WITH GOOD POTENTIAL FOR LARGE HAIL...HIGH WINDS...AND PERHAPS A COUPLE TORNADOES. LARGE SCALE FORCING AND FORECAST EVOLUTION OF CONVECTION STRONGLY SUGGESTS THAT AN FORWARD PROPAGATING MCS OR TWO SHOULD DEVELOP EAST INTO THE DAKOTAS THROUGH LATE EVENING. DEGREE OF POTENTIAL INSTABILITY FEEDING INTO THIS ACTIVITY ON PLAINS LOW LEVEL JET SHOULD MAINTAIN THE THREAT FOR SEVERE WEATHER EAST ACROSS THE NRN PLAINS WELL INTO EARLY THURSDAY. ...CAROLINAS... STRONG LOW LEVEL SHEAR WITHIN RIGHT FRONT QUADRANT OF ALBERTO CIRCULATION WILL DEVELOP ACROSS THE ERN CAROLINAS DURING THE DAY. RECENT FRONTAL PASSAGE ACROSS THE AREA HAS BROUGHT IN LOWER DEWPOINTS/MORE STABLE AIR MASS. DESPITE STRONG MOISTURE ADVECTION AHEAD OF THE TROPICAL SYSTEM...WIDESPREAD PRECIPITATION IN ADVANCE OF THE LOW MAY KEEP DESTABILIZATION LIMITED GIVEN ANTECEDENT RELATIVELY DRY BOUNDARY LAYER. WHILE AN ISOLATED/BRIEF TORNADO CANNOT BE RULED OUT WITH SUCH A SYSTEM...POTENTIAL FOR WEAK INSTABILITY PRECLUDES GREATER PROBABILITIES AT THIS TIME. STRONGER INSTABILITY MAY...HOWEVER...DEVELOP IN THE WAKE OF ALBERTO...ACROSS SRN NC/SC...AS SKIES CLEAR DURING THE AFTERNOON. INCREASING WLY FLOW ACROSS THE REGION AHEAD OF OH VALLEY/SRN APPALACHIANS SHORT WAVE TROUGH COULD PROMOTE SCATTERED ORGANIZED STORMS OVER PARTS OF THE REGION BY LATE AFTERNOON/EARLY EVENING. A SMALL CLUSTER OF SEVERE STORMS APPEARS POSSIBLE FROM SERN NC ACROSS ERN SC DURING THIS TIME FRAME. IF THIS SIGNAL REMAINS COHERENT IN LATER FORECASTS...SEVERE PROBABILITIES MAY NEED TO BE INCREASED OVER PARTS OF THE AREA. ...MO VALLEY TO MIDWEST... BAND OF SCATTERED CONVECTION MAY BE ONGOING FROM ERN SD...ACROSS PARTS OF IA...AND INTO SRN WI/NRN IL...WITHIN WARM CONVEYOR ON THE EDGE OF THE CAP EARLY WEDNESDAY. IT IS POSSIBLE THAT SOME OF THIS ACTIVITY MAY ROOT INTO MARGINALLY UNSTABLE BOUNDARY LAYER FROM SRN WI INTO NRN IL/NWRN IND DURING THE DAY AND INTO THE EVENING. THIS ACTIVITY MIGHT BE FURTHER SUSTAINED BY STRONGER SHEAR/FORCING ASSOCIATED WITH A SHORT WAVE DEVELOPING SEWD ACROSS THE REGION. LATEST NAM-WRF INDICATES THE POTENTIAL FOR A FEW SEVERE STORMS WHILE NAM-ETA IS NOT AS STRONG WITH THE MID LEVEL IMPULSE. GIVEN THESE DIFFERENCES...WILL ONLY OUTLOOK LOW SEVERE PROBABILITIES AT THIS TIME. ...MID ATLANTIC/NORTHEAST... FORCING ASSOCIATED WITH OH VALLEY SHORT WAVE WILL CONTRIBUTE TO SCATTERED TSTM DEVELOPMENT WITHIN WEAKLY UNSTABLE AIR MASS FROM WV/NRN VA NEWD TO NEW ENGLAND DURING THE AFTERNOON. WHILE FORCING AND SHEAR APPEAR SUPPORTIVE OF A FEW STORMS WITH MARGINALLY SEVERE HAIL OR ISOLATED DAMAGING WINDS...LACK OF STRONGER DESTABILIZATION SHOULD PREVENT THESE THREATS FROM BECOMING MORE WIDESPREAD. ..CARBIN.. 06/13/2006  From swody2 at goshenarc.org Wed Jun 14 06:06:45 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 14 Jun 2006 02:06:45 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140603 SWODY2 SPC AC 140602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT WED JUN 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN/CENTRAL PLAINS... UPPER TROUGH OVER THE INTER MOUNTAIN WEST WILL SHIFT EWD ACROSS THE ROCKIES SPLITTING INTO TWO DISTINCT FEATURES THURSDAY. A SIGNIFICANT UPPER SPEED MAX WILL DIG SEWD ACROSS NV INTO AZ/NM FORCING HEIGHT FALLS INTO THE SRN ROCKIES...WHILE NRN MORE PERSISTENT MID LEVEL CIRCULATION WILL SHIFT EAST ALONG THE U.S./CANADIAN BORDER. LATEST MODEL GUIDANCE SEEM A BIT AGGRESSIVE IN BOUNDARY LAYER MOISTURE RECOVERY ACROSS THE ERN DAKOTAS/MN WHERE SFC DEW POINTS ARE FORECAST TO RISE INTO THE UPPER 60S. OF PARTICULAR CONCERN FOR MUCH OF THE PLAINS IS THE PERSISTENT WARMTH AT 700 MB. DNR SOUNDING THIS EVENING WAS QUITE WARM WITH 20C...WHILE RIW WAS 17C. THIS HEAT PLUME WILL ADVECT ACROSS THE PLAINS AS AN ELEVATED MIXED LAYER THAT SHOULD IMPEDE BOUNDARY LAYER CONVECTION MUCH OF THE AFTERNOON. STRONG HEATING WILL CERTAINLY PROVE BENEFICIAL IN BREAKING THIS CAP ALONG ADVANCING WIND SHIFT IN THE ABSENCE OF STRONG FORCING. TWO REGIONS WHERE STRONGER FORCING SEEM POSSIBLE ARE ACROSS SRN CANADA...THEN LATER IN THE EVENING ALONG NOSE OF STRENGTHENING LLJ OVER THE PLAINS. LATE EVENING THUNDERSTORM ACTIVITY SEEMS LIKELY ALONG/NORTH OF THE BOUNDARY FROM NEB INTO SERN SD. OTHERWISE...ISOLATED DAYTIME STORMS ARE POSSIBLE WHERE STRONG HEATING OCCURS. UNCERTAINTY IN CONVECTIVE MODE COMBINED WITH STRONG CAP LEND ENOUGH UNCERTAINTY IN SEVERE EVOLUTION TO MAINTAIN LOW PROBABILITIES AT THIS TIME. HOWEVER...SUFFICIENT VERTICAL SHEAR WILL SPREAD ACROSS THE BOUNDARY FOR THE POTENTIAL FOR ORGANIZED ACTIVITY. WILL MONITOR THIS REGION FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ..DARROW.. 06/14/2006  From swody2 at goshenarc.org Wed Jun 14 17:30:20 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 14 Jun 2006 13:30:20 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141726 SWODY2 SPC AC 141726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT WED JUN 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MIDWEST SWWD INTO THE CENTAL HIGH PLAINS... ...SYNOPSIS... UPPER TROUGH...CURRENTLY LOCATED ACROSS THE INTERMOUNTAIN WEST ...IS EXPECTED TO MOVE EWD INTO THE ROCKIES AND NRN/CENTRAL PLAINS ON THURSDAY. WHILE THE MODELS ARE CONSISTENT IN A CLOSED LOW DEVELOPING WITHIN THE TROUGH NORTH OF MT...A STRONG SHORTWAVE TROUGH AND ASSOCIATED SPEED MAX WILL DIG SEWD ACROSS NV INTO AZ/NM. ALTHOUGH THE COLD FRONT IS FORECAST TO EXTEND FROM CENTRAL ND/SD SWWD INTO NERN CO AT THE START OF THE PERIOD...THE FRONT SHOULD EDGE ONLY SLOWLY EWD DURING THE PERIOD AS THE SWLY MID LEVEL WINDS ALOFT...PARALLEL TO THE FRONT... STRENGTHEN TO 50-60 KT. ...NORTHERN PLAINS AND UPPER MIDWEST... A WEAKENING MCS MAY BE ONGOING AT THE START OF THE PERIOD ACROSS PORTIONS OF ND. HOWEVER...THE REMNANTS OF THIS CONVECTION AND A POSSIBLE MCV...MAY INTENSIFY DURING THE AFTERNOON ACROSS MN/NWRN WI AS THE UPPER LEVEL DIFFLUENCE STRENGTHENS ALONG WITH WEAK LOW LEVEL WARM ADVECTION. THE FORECAST OF UPPER 60 DEWPOINTS ARE LIKELY OVERESTIMATED OR SHOULD BE CONFINED CLOSE TO THE SURFACE ...BUT LOWER 60 DEWPOINTS AND STEEP MID LEVEL LAPSE RATES WILL RESULT IN MLCAPES FROM 1500-2000 J/KG. STORM MODE IS UNCERTAIN... BUT SELY BOUNDARY LAYER WINDS VEERING TO WLY SHOULD PROVIDE SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS. THE RELATIVELY DRY BOUNDARY INDICATES THAT LARGE HAIL AND WIND DAMAGE WOULD BE THE MAIN THREAT WITH THESE STORMS. ALTHOUGH THE COLD FRONT IS EXPECTED TO BE LOCATED ACROSS ERN ND/SD DURING THE AFTERNOON...ALONG WITH AT LEAST MODERATE INSTABILITY... WEAKENING CONVERGENCE AND MORNING CONVECTIVE OUTFLOW BOUNDARIES MAY INHIBIT STORM DEVELOPMENT DURING THE AFTERNOON. IF STORMS ARE ABLE TO DEVELOP...THE DEGREE OF INSTABILITY AND SHEAR WOULD SUPPORT A SEVERE THREAT. ...CENTRAL AND ERN NEB/NWRN KS/ERN CO... MODELS ARE REMARKABLY SIMILAR IN INITIATING STORMS ALONG THE FRONT IN THE NWRN KS AREA BY LATE AFTERNOON...AND THIS APPEARS REASONABLE AS LARGE SCALE LIFT INCREASES WITH SHORTWAVE TROUGH APPROACHING FROM THE AZ/NM AREA. THE STORMS ARE ALSO LIKELY TO DEVELOP NEWD ALONG THE FRONT ACROSS NEB AS THE FORCING SPREADS NEWD. ALTHOUGH LOWER 60 DEWPOINTS ARE CURRENTLY STREAMING NWD FROM SRN TX INTO WRN KS...STRONG HEATING AND A LARGE AMOUNT OF DRY AIR FROM BETWEEN 800 AND 600 MB...IS LIKELY TO RESULT IN DEWPOINTS LOWERING INTO THE 50S. THESE DEWPOINTS AND VERY STEEP LAPSE RATES SHOULD STILL RESULT IN MLCAPES AROUND 1500 J/KG BY LATE AFTERNOON. VEERING WIND PROFILES AND STRENGTHENING MID LEVEL WINDS WILL BE FAVORABLE FOR STORMS WITH ROTATION. THE FORECAST OF INVERTED-V SOUNDINGS FROM THE SURFACE TO 600 MB SUGGESTS THAT WIND DAMAGE WILL BE THE MAIN THREAT. ..IMY.. 06/14/2006  From swody2 at goshenarc.org Thu Jun 15 06:06:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 15 Jun 2006 02:06:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150603 SWODY2 SPC AC 150602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT THU JUN 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE TO THE UPPER MS VALLEY... ...CNTRL/SRN HIGH PLAINS... LATEST MODEL GUIDANCE CONTINUES TO SUGGEST WRN U.S. TROUGH WILL SPLIT WITH SIGNIFICANT AMOUNT OF DIGGING EXPECTED ACROSS THE 4-CORNERS INTO THE SRN HIGH PLAINS BY THE END OF THE PERIOD. MODELS HAVE BEEN CONSISTENT WITH THIS EVOLUTION ALTHOUGH THE CONVECTIVE SCENARIO REMAINS SOMEWHAT COMPLEX AS VERY WARM AIR AT 700MB HAS YET TO BE DISPLACED...EITHER THROUGH EXTENSIVE CONVECTIVE OVERTURNING...OR THROUGH LARGE SCALE ASCENT. IT APPEARS THICKNESSES WILL COOL SUFFICIENTLY OVER THE NEXT FEW DAYS FOR SEVERAL CONVECTIVE EPISODES ALONG/POST FRONTAL FROM ERN CO INTO NEB. THIS SHOULD FORCE SFC FRONT SWD ACROSS THE HIGH PLAINS WHERE BOUNDARY LAYER MOISTURE SHOULD RETURN TO UPSLOPE REGIONS OF ERN CO...TO THE NW OF LEE CYCLONE OVER THE TX PANHANDLE. LATEST THINKING IS THUNDERSTORMS MAY BE ONGOING EARLY IN THE PERIOD ALONG FRONTAL ZONE ACROSS NEB INTO NWRN KS. THIS ACTIVITY MAY GENERATE ISOLATED LARGE HAIL...BUT OTHERWISE SPREAD NEWD ALONG EXISTING CONVERGENCE ZONE WITH LITTLE WARM SECTOR PROPAGATION. LATER IN THE DAY STRONG HEATING ACROSS THE HIGH PLAINS FROM THE TX PANHANDLE INTO SERN CO SHOULD PROVE ADEQUATE FOR SFC PARCELS TO REACH THEIR LFC...ESPECIALLY AS MID LEVELS COOL BENEATH UPPER TROUGH. SEVERE THUNDERSTORMS SHOULD EVOLVE BENEATH MODEST MID-HIGH LEVEL FLOW ALONG DRY LINE...AND ACROSS UPSLOPE REGIONS INTO WRN KS/ERN CO. THIS ACTIVITY WILL GRADUALLY SPREAD EWD DURING THE EVENING HOURS INTO WRN OK/CNTRL KS AS LLJ SHIFTS INTO THE SRN PLAINS AFTER DARK. ...NRN MS VALLEY... 00Z NAM IS A BIT MORE AGGRESSIVE WITH WEAK HEIGHT FALLS ACROSS THE UPPER MS VALLEY REGION FRIDAY...WHILE GFS IS NEUTRAL DURING THE DAYTIME WITH HEIGHT CHANGES AHEAD OF SASKATCHEWAN/ALBERTA SHORTWAVE TROUGH. IDENTIFYING A PARTICULAR TIME FOR HEIGHTENED THUNDERSTORM DEVELOPMENT IS PROVING QUITE DIFFICULT ACROSS THIS REGION AS LOW LEVEL WARM ADVECTION WILL LIKELY ENHANCE EARLY MORNING DEVELOPMENT ALONG FRONTAL ZONE FROM SERN SD INTO MN. WHILE DAYTIME HEATING SHOULD AID ADDITIONAL DEVELOPMENT ALONG SFC WIND SHIFT/OUTFLOW DEMARKATION...FORCING AHEAD OF CANADIAN TROUGH DOES NOT APPEAR PARTICULARLY STRONG ACROSS THE NRN U.S. ISOLATED SEVERE WIND GUSTS MAY BE THE GREATEST RISK OF SEVERE WITH ANY BOW-TYPE ECHOES THAT CAN EVOLVE AND BECOME ORIENTED PERPENDICULAR TO MEAN SWLY WIND VECTORS. ..DARROW.. 06/15/2006  From swody2 at goshenarc.org Thu Jun 15 17:37:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 15 Jun 2006 13:37:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151734 SWODY2 SPC AC 151733 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 PM CDT THU JUN 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE TO THE UPPER MS VALLEY...... ...SYNOPSIS... LARGE SCALE UPPER TROUGH NOW OVER THE WEST WILL MOVE EAST TO THE PLAINS/UPPER MS VALLEY FRIDAY AS A BELT OF FAST WLY FLOW MOVES INLAND OVER THE PACIFIC NORTHWEST/NRN ROCKIES...AND SHORT WAVE RIDGING DEVELOPS OVER THE GREAT BASIN/FOUR CORNERS. THE WRN TROUGH WILL DEVELOP EAST IN ESSENTIALLY TWO SEGMENTS AS A STRONG DOWNSTREAM RIDGE PERSISTS OVER THE ERN GREAT LAKES...MIDWEST...AND SOUTH. A MORE PROGRESSIVE NRN SEGMENT OF THE TROUGH...WITH STRONGER HEIGHT FALLS...WILL EVOLVE FROM THE CLOSED LOW CURRENTLY SITUATED ACROSS NRN MT/SRN ALBERTA. THIS DISTURBANCE WILL BE EJECTED EWD FROM THE NRN PLAINS TO THE UPPER MS VALLEY AND SCNTRL CANADA AS RELATIVELY FAST UPSTREAM WLY FLOW AND PACIFIC IMPULSE MOVE INLAND ACROSS THE NRN ROCKIES. THE SLOWER AND MORE AMPLIFIED SRN SEGMENT OF THE TROUGH...CURRENTLY CROSSING THE SWRN U.S...WILL TRANSLATE EWD FROM THE FOUR CORNERS TO THE CNTRL/SRN PLAINS THROUGH EARLY SATURDAY. MID LEVEL CIRCULATION...CURRENTLY EMBEDDED IN DEEP LAYER ELY FLOW ACROSS THE LOWER RIO GRANDE VALLEY...WILL BE INFLUENCED AND EVENTUALLY DIRECTED NEWD ACROSS THE ARKLATEX BY THE APPROACHING PLAINS TROUGH. AN EXTENSIVE BELT OF SWLY/SLY LOW LEVEL FLOW WILL PRECEDE MID LEVEL HEIGHT FALLS AND ASSOCIATED FRONT SPREADING EAST ACROSS THE PLAINS/UPPER MS VALLEY THROUGH THE PERIOD. THIS LOW LEVEL FLOW WILL MAINTAIN A VERY WARM AND MODESTLY MOIST BOUNDARY LAYER FROM THE GULF TO THE WRN GREAT LAKES ON FRIDAY...BENEATH A RELATIVELY STRONG CAP. MOST VIGOROUS CONVECTIVE DEVELOPMENT WILL OCCUR WHERE STRONGER FORCING ASSOCIATED WITH MODEST HEIGHT FALLS...LOW LEVEL JET...AND FRONTAL LIFT CAN ACT TO OVERCOME THE CAP. ...CNTRL/SRN PLAINS... A COUPLE OF CLUSTERS OF STORMS ARE EXPECTED TO BE ONGOING EARLY FRIDAY MORNING ACROSS THE CNTRL PLAINS FROM SD/NEB SWWD TO ERN CO AND PERHAPS WRN KS. CLOUDS AND OUTFLOW FROM THIS ACTIVITY WILL EFFECTIVELY REDEFINE THE DEEP LAYER SYNOPTIC FRONTAL ZONE ASSOCIATED WITH THE LARGER SCALE TROUGH DEVELOPING EAST ACROSS THE ROCKIES. INFLUENCE OF PRESSURE FALLS ASSOCIATED WITH LEE/FRONTAL WAVE DEVELOPMENT ACROSS THE HIGH PLAINS WILL MAINTAIN MASS INFLOW ACROSS THE BOUNDARY FROM KS TO NEB. STRONG DIURNAL DESTABILIZATION OF INFLOW AIR MASS...AND DIFFERENTIAL HEATING ACROSS THE BOUNDARY...WILL OVERCOME WARM SECTOR INHIBITION TO SUPPORT SURFACE-BASED TSTMS WITHIN STRONGLY UNSTABLE AIR MASS ACROSS KS/NEB THROUGH THE AFTERNOON. ADDITIONAL TSTM DEVELOPMENT APPEARS LIKELY AS DRYLINE MIXES EAST ACROSS THE TX/OK PNHDLS/SWRN KS DURING THE AFTERNOON. MOIST POST-FRONTAL UPSLOPE FLOW FROM WRN NEB INTO ERN CO WILL SUPPORT/MAINTAIN TSTMS ACROSS THESE AREAS WHERE INSTABILITY MAY BE MORE LIMITED DUE TO EARLY CONVECTION/CLOUD COVER. MID LEVEL SLY FLOW IS EXPECTED TO STRENGTHEN THROUGH THE DAY OVER THE PLAINS AND RESULT IN SUFFICIENT SHEAR FOR STORM PERSISTENCE/ORGANIZATION AS MID/UPPER TROUGH SPREADS EAST. FORCING/ORGANIZATION ASSOCIATED WITH THE LARGER SCALE FRONT/OUTFLOW/DRYLINE AND FRONTAL WAVES WILL LIKELY RESULT IN ORGANIZED CLUSTERS OF STORMS/EMBEDDED SUPERCELLS WITH HAIL/WIND AND SOME TORNADO POTENTIAL. MORE DISCRETE STORMS MAY INITIALLY BE POSSIBLE NEAR THE DRYLINE GIVEN STRONGER CAPPING IN THIS ENVIRONMENT. AN MCS OR TWO APPEAR LIKELY TO EVOLVE FROM LATE AFTERNOON CONVECTION AND SPREAD ESEWD OVER KS/OK AS DESTABILIZATION/INFLOW IS MAINTAINED BY BOTH LARGE SCALE HEIGHT FALLS AND LOW LEVEL JET...AS WELL AS LIFT ALONG POTENTIALLY EXTENSIVE CONVECTIVE COLD POOL. ...UPPER MS VALLEY... MORE PROGRESSIVE NATURE OF THE NRN SEGMENT OF THE TROUGH SHOULD PROMOTE FRONTAL ADVANCE FROM THE DAKOTAS EWD TO MN. LIFT WITHIN WARM CONVEYOR BELT AHEAD OF THE FRONT...FROM ERN SD ACROSS MN INTO WI...SHOULD SUPPORT ONE OR TWO AREAS OF ACTIVE CONVECTION STRENGTHENING AS GREATER INSTABILITY IS TAPPED DURING THE DAY. POTENTIAL FOR FRONTAL WAVES AND PREFERENTIALLY ORIENTED CONVECTIVE OUTFLOWS WITHIN INCREASINGLY UNSTABLE AND SHEARED ENVIRONMENT WILL RESULT IN A NUMBER OF ORGANIZED STORMS/SUPERCELLS WITH HAIL/WIND AND TORNADO POTENTIAL. ..CARBIN.. 06/15/2006  From swody2 at goshenarc.org Fri Jun 16 05:53:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 16 Jun 2006 01:53:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160550 SWODY2 SPC AC 160549 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1249 AM CDT FRI JUN 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS SAT/SAT NIGHT ACROSS PARTS OF THE CNTRL/SRN PLAINS.... MODELS INDICATE THAT A TRANSITION TOWARD A LESS AMPLIFIED UPPER FLOW REGIME WILL BEGIN DURING THIS FORECAST PERIOD...WITH STRONGER WESTERLIES GRADUALLY DEVELOPING NORTHWARD THROUGH THE NORTHWESTERN/ NORTH CENTRAL U.S. INTO SOUTHEASTERN CANADA. WITHIN THIS REGIME...A CLOSED LOW WILL ACCELERATE EASTWARD ALONG THE CENTRAL CANADIAN/U.S. BORDER TODAY...IN RESPONSE TO A RAPIDLY APPROACHING UPSTREAM SHORT WAVE TROUGH. A SIGNIFICANT IMPULSE EMBEDDED WITHIN THE BROADER SCALE CIRCULATION IS PROGGED TO LIFT AWAY FROM THE INTERNATIONAL BORDER TOWARD HUDSON/JAMES BAY EARLY SATURDAY. HOWEVER...MODELS SUGGEST REMNANTS OF CLOSED LOW AND UPSTREAM IMPULSE WILL CONSOLIDATE INTO ANOTHER BROADER SCALE TROUGH...WHICH WILL CONTINUE EASTWARD TOWARD CONFLUENT REGIME OVER THE UPPER GREAT LAKES REGION LATER SATURDAY INTO EARLY SUNDAY. FARTHER SOUTH...MID-LEVEL HEIGHT RISES ARE PROGGED THROUGH MUCH OF THE CENTRAL/SOUTHERN TIER OF THE U.S...AS SUBTROPICAL RIDGING BEGINS TO DEVELOP NORTHWARD. A SHORT WAVE TROUGH WILL PROGRESS EAST OF THE SOUTHERN ROCKIES THROUGH MUCH OF THE SOUTHERN PLAINS BY LATE SATURDAY/EARLY SUNDAY. THIS SYSTEM WILL WEAKEN BETWEEN UPPER HIGH CENTERS DEVELOPING INTO THE EASTERN AND SOUTHWESTERN STATES. HOWEVER...FORCING ASSOCIATED WITH THIS FEATURE...AND REMNANTS OF A DOWNSTREAM WAVE SLOWLY LIFTING OUT OF THE WESTERN GULF COAST REGION...ARE EXPECTED TO CONTRIBUTED TO CONSIDERABLE CONVECTIVE DEVELOPMENT OVER A BROAD AREA OF THE CENTRAL U.S. DURING THIS FORECAST PERIOD. THE MOST VIGOROUS THUNDERSTORMS ARE EXPECTED TO GENERALLY BE FOCUSED NEAR A LEE SURFACE TROUGH ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS. ...CENTRAL/SOUTHERN PLAINS... VARIABILITY EXISTS AMONG THE MODELS CONCERNING THE TRACK OF THE MID-LEVEL COLD CORE...BUT A LARGE CONVECTIVE CLUSTER COULD BE ONGOING EARLY SATURDAY IN ASSOCIATION WITH THIS FEATURE ACROSS THE CENTRAL/SOUTHERN HIGH PLAINS. THIS SEEMS MOST LIKELY ACROSS PARTS OF CENTRAL KANSAS/WESTERN OKLAHOMA INTO NORTHWEST TEXAS. ALONG/AHEAD OF ASSOCIATED SURFACE COLD POOL...AND SOUTHWARD ALONG SURFACE TROUGH/DRY LINE THROUGH WESTERN TEXAS...LAPSE RATES SHOULD BECOME QUITE STEEP IN CONJUNCTION WITH DIFFERENTIAL THERMAL ADVECTION AND DAYTIME HEATING. THIS WILL SUPPORT MODERATE TO STRONG INSTABILITY BY LATE AFTERNOON...WITH MIXED LAYER CAPE PEAKING IN THE 2000 TO 4000 J/KG RANGE. DESTABILIZATION AND LARGE-SCALE FORCING ARE EXPECTED TO GENERATE SUBSTANTIAL VIGOROUS LATE AFTERNOON/EVENING THUNDERSTORMS...WITHIN A THERMODYNAMIC ENVIRONMENT FAVORABLE FOR DAMAGING DOWNBURSTS AND LARGE HAIL. BEFORE INSTABILITY WANES WITH LOSS OF DAYTIME HEATING ...ACTIVITY FROM PARTS OF CENTRAL/SOUTHERN OKLAHOMA INTO WEST CENTRAL TEXAS COULD BE AUGMENTED BY MODERATELY STRONG SHEAR...AS A SOUTHERLY LOW-LEVEL JET STRENGTHENS DURING THE EVENING BENEATH WESTERLY MID-LEVEL FLOW. ...UPPER MISSISSIPPI VALLEY/GREAT LAKES REGION... INSTABILITY IS MORE UNCERTAIN ACROSS THIS AREA DUE TO THE LIKELIHOOD OF WEAKER LAPSE RATES. COLDER MID-LEVEL AIR MASS IS PROGGED TO LAG TO THE WEST OF A PRE-FRONTAL LOW-LEVEL CONFLUENT BAND...WHICH IS EXPECTED TO BECOME THE FOCUS FOR THE PRIMARY THUNDERSTORM ACTIVITY FROM PARTS OF NORTHEAST IOWA/SOUTHWEST MINNESOTA THROUGH CENTRAL WISCONSIN/UPPER MICHIGAN LATE SATURDAY AFTERNOON AND EVENING. SURFACE HEATING IN THE VICINITY OF THIS FEATURE MAY ALSO BE RESTRICTED BY CONSIDERABLE CLOUD COVER. HOWEVER...MODERATELY STRONG /30-35+ KT/ SOUTHWESTERLY MEAN FLOW REGIME WILL ENHANCE STORM MOTIONS AND POTENTIAL FOR GUSTY WINDS...WHICH COULD BRIEFLY APPROACH OR EXCEED SEVERE LIMITS. ..KERR.. 06/16/2006  From swody2 at goshenarc.org Fri Jun 16 17:28:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 16 Jun 2006 13:28:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161725 SWODY2 SPC AC 161724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT FRI JUN 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL/SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM FAR NRN IA/SERN MN TO UPPER PENINSULA OF MI... ...SYNOPSIS... STRONG WLY MID/UPPER LEVEL FLOW WILL CONTINUE TO PENETRATE FARTHER INLAND ACROSS THE NRN TIER OF STATES ON SATURDAY REACHING THE NRN PLAINS TO UPPER GREAT LAKES REGION. THIS WILL ALLOW STORM SYSTEMS TO BE MORE PROGRESSIVE ACROSS THE NRN STATES INTO SERN CANADA. ONE SHORT WAVE TROUGH...INITIALLY LOCATED OVER SRN MANITOBA SATURDAY MORNING...SHOULD WEAKEN AS UPSTREAM TROUGH NOW ENTERING NW WA/SW BRITISH COLUMBIA AMPLIFIES EWD ACROSS ND TO NRN MN/WRN ONTARIO. THE SRN EXTENT OF THE CURRENT WRN U.S. TROUGH IS EXPECTED TO MOVE EWD INTO THE CENTRAL/SRN PLAINS AND WEAKEN SATURDAY AS IT BECOMES DETACHED FROM STRONGER FLOW TO THE NORTH AND RESIDES BETWEEN HEIGHT RISES OVER THE SOUTHWEST AND ERN STATES. MEANWHILE...SHORT WAVE TROUGH...NOW LOCATED ALONG THE UPPER TX COAST...IS EXPECTED TO WEAKEN AS IT TRACKS NEWD THROUGH THE LOWER MS TO LOWER OH VALLEYS. SURFACE TROUGH WILL MOVE SLOWLY EWD ACROSS THE CENTRAL STATES AND SHOULD EXTEND FROM NRN MN SWWD THROUGH ERN NEB/CENTRAL KS TO W TX BY 18/00Z. ...CENTRAL/SRN PLAINS... CONSIDERABLE CONVECTIVE DEVELOPMENT IS EXPECTED ACROSS A BROAD AREA OF THE CENTRAL U.S. IN ASSOCIATION WITH THE LOWER MS VALLEY IMPULSE AND THE CENTRAL/SRN PLAINS UPPER TROUGH. THE MOST VIGOROUS THUNDERSTORM DEVELOPMENT AND SEVERE POTENTIAL SHOULD BE FOCUSED ACROSS PARTS OF OK AND TX ALONG LEE SURFACE TROUGH AND OUTFLOW BOUNDARIES LEFT OVER FROM DAY 1 CONVECTION. AT 12Z SATURDAY...ONE OR TWO CLUSTERS OF STORMS SHOULD BE ONGOING ACROSS PARTS OF NEB/KS INTO OK ASSOCIATED WITH WAA ALONG STRONG SSWLY LLJ. THIS ACTIVITY IS EXPECTED TO MOVE EWD ALLOWING FOR SURFACE HEATING IN ITS WAKE ALONG/E OF SURFACE TROUGH. LAPSE RATES SHOULD BECOME QUITE STEEP IN THIS ENVIRONMENT PRIMARILY FROM OK SWD INTO TX WHERE SURFACE HEATING BENEATH COLDER MID LEVEL TEMPERATURES WILL RESULT IN MODERATE INSTABILITY. MODERATE WNWLY MID LEVEL FLOW /40+ KT/ WILL CONTRIBUTE TO SUFFICIENT DEEP LAYER SHEAR FOR STORMS TO BECOME ORGANIZED WITH THERMODYNAMICS FAVORING HAIL AND STRONG DOWNBURSTS WINDS. STRENGTHENING SLY LLJ ACROSS SRN/CENTRAL TX IS EXPECTED TO SUPPORT A CONTINUED SEVERE THREAT WITH ACTIVITY ACROSS THESE PARTS OF TX SATURDAY NIGHT. ...UPPER MS VALLEY/WRN GREAT LAKES REGION... THUNDERSTORMS MAY BE ONGOING AT 12Z SATURDAY FROM NEB NEWD ALONG A PRE-FRONTAL TROUGH EXTENDING ACROSS SWRN MN TO NRN WI/WRN U.P. OF MI. SURFACE HEATING ALONG/S OF THIS PRE-FRONTAL BOUNDARY IS EXPECTED TO SUPPORT AT LEAST MODERATE INSTABILITY ACROSS PARTS OF SRN/ERN MN INTO NRN WI/WRN U.P. OF MI DESPITE WEAKER MID LEVEL LAPSE RATES. LARGE SCALE ASCENT AHEAD OF A WEAK MID LEVEL IMPULSE MOVING NEWD ACROSS THIS REGION SHOULD SUPPORT THUNDERSTORM DEVELOPMENT BY SATURDAY AFTERNOON ALONG THE PRE-FRONTAL TROUGH. MODERATE INSTABILITY COMBINED WITH 40-50 KT OF SWLY MID LEVEL FLOW WILL SUPPORT ORGANIZED STORMS WITH HAIL AND DAMAGING WINDS BEING THE PRIMARY THREATS WITH THE STRONGEST ACTIVITY. GIVEN THIS SCENARIO...HIGHER PROBABILITIES AND A SLIGHT SEVERE RISK HAVE BEEN ADDED TO THIS REGION. ..PETERS.. 06/16/2006  From swody2 at goshenarc.org Sat Jun 17 05:49:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 17 Jun 2006 01:49:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170545 SWODY2 SPC AC 170544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT SAT JUN 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE STRONGER WESTERLIES WILL PERSIST IN A BELT EXTENDING OUT OF THE NORTHERN PACIFIC...THROUGH THE NORTHWESTERN AND NORTH CENTRAL U.S....INTO SOUTHEASTERN CANADA THROUGH THIS FORECAST PERIOD. A COUPLE OF WAVES EMBEDDED WITHIN THIS REGIME ARE PROGGED TO REMAIN PROGRESSIVE...ONE ADVANCING FROM THE NORTH CENTRAL CANADIAN/U.S. BORDER AREA INTO THE GREAT LAKES...ANOTHER ADVANCING INLAND ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. IN ADVANCE OF LATTER FEATURE...AN UPPER RIDGE IS FORECAST TO BUILD ACROSS THE SOUTHERN U.S./NORTHERN MEXICAN PLATEAU REGION INTO THE CENTRAL/SOUTHERN PLAINS BY LATE SUNDAY NIGHT. WITH A SHARP UPPER RIDGE REMAINING STRONG THROUGH MUCH OF THE PERIOD ACROSS THE EASTERN STATES...SHEARING OF AN UPPER TROUGH TO THE SOUTH OF THE STRONGER WESTERLIES WILL CONTINUE ACROSS EASTERN PORTIONS OF THE SOUTHERN PLAINS INTO THE LOWER HALF OF THE MISSISSIPPI VALLEY. ...EAST OF ROCKIES... CONSIDERABLE UNCERTAINTY EXISTS CONCERNING SEVERE POTENTIAL SUNDAY/SUNDAY NIGHT. IT WILL REMAIN VERY MOIST FROM THE WESTERN/ CENTRAL GULF STATES NORTHWARD AHEAD OF A PRE-FRONTAL CONFLUENCE INTO THE LOWER GREAT LAKES REGION. HOWEVER...FLOW FIELDS ARE PROGGED TO WEAKEN CONSIDERABLY ACROSS THE SOUTH CENTRAL STATES IN RESPONSE TO EVOLVING UPPER PATTERN. AND...WHERE STRONG LOW/MID-LEVEL FLOW FIELDS PERSIST AHEAD OF NORTH CENTRAL U.S. UPPER TROUGH...WEAK LAPSE RATES WILL TEND TO MINIMIZE DESTABILIZATION. THIS WILL FURTHER BE LIMITED BY EXTENSIVE CLOUD COVER ASSOCIATED WITH A COUPLE OF DAYS OF WIDESPREAD CONVECTIVE DEVELOPMENT. STABILIZING INFLUENCE OF SURFACE COLD POOLS GENERATED BY THIS CONVECTION IS ALSO UNCERTAIN. IN WAKE OF PRE-FRONTAL CONFLUENT ZONE...PROGGED TO SHIFT ACROSS THE OHIO VALLEY/LOWER GREAT LAKES REGION DURING THE DAY SUNDAY... DIFFERENTIAL THERMAL ADVECTION ALONG/JUST AHEAD OF COLD FRONT SEEMS TO OFFER BEST POTENTIAL/FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT. BY LATE AFTERNOON...THE FRONT IS EXPECTED TO CURVE FROM THE UPPER GREAT LAKES REGION THROUGH THE NORTH CENTRAL PLAINS. THOUGH MOISTURE WILL BE LIMITED NEAR THIS FEATURE ...SUFFICIENT DESTABILIZATION APPEARS LIKELY FOR AT LEAST SCATTERED THUNDERSTORMS. PERHAPS ENHANCED BY FAVORABLE SHEAR BENEATH SEASONABLY STRONG CYCLONIC MID-LEVEL FLOW...A FEW STORMS COULD PRODUCE HAIL/GUSTY WINDS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS. ACTIVITY MAY SPREAD SOUTHEASTWARD THROUGH LOWER GREAT LAKES AND PARTS OF THE MIDDLE MISSISSIPPI VALLEY BEFORE DIMINISHING SUNDAY EVENING. FARTHER SOUTH...POTENTIAL FOR SURFACE HEATING APPEARS MUCH BETTER FROM PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY...WHERE 70F SURFACE DEW POINTS SHOULD PERSIST. BENEATH LINGERING MID-LEVEL COOL POCKET...THIS COULD CONTRIBUTE TO A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/LOCALIZED SEVERE STORMS WITH HAIL/GUSTY WINDS. ...WEST OF ROCKIES... FORCING/SHEAR ASSOCIATED WITH A 40-50 KT MID-LEVEL JET STREAK IS EXPECTED TO ENHANCE CONVECTIVE POTENTIAL NEAR LOW/MID-LEVEL BAROCLINIC ZONE ACROSS PARTS OF EASTERN OREGON/CENTRAL AND SOUTHERN IDAHO LATE SUNDAY AFTERNOON/EVENING. MOISTURE WILL BE LIMITED...BUT LAPSE RATES WILL BECOME QUITE STEEP AND SUPPORTIVE OF AT LEAST WIDELY SCATTERED STORMS WITH POTENTIAL FOR MICROBURSTS. ..KERR.. 06/17/2006  From swody2 at goshenarc.org Sat Jun 17 17:34:06 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 17 Jun 2006 13:34:06 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 171728 SWODY2 SPC AC 171728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 PM CDT SAT JUN 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG WESTERLIES WILL PERSIST IN A BELT EXTENDING FROM THE NORTHWESTERN AND NORTH CENTRAL U.S. INTO SOUTHEASTERN CANADA THIS FORECAST PERIOD. A COUPLE OF WAVES EMBEDDED WITHIN THIS REGIME ARE PROGGED TO REMAIN PROGRESSIVE...ONE ADVANCING FROM THE NORTH CENTRAL U.S./CANADIAN BORDER AREA INTO THE GREAT LAKES REGION... AND A SECOND MOVING INLAND ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. IN ADVANCE OF THE LATTER FEATURE...AN UPPER RIDGE IS FORECAST TO BUILD EWD INTO THE CENTRAL/SRN PLAINS WITH HEIGHT RISES ALSO EXTENDING NWD THROUGH THE NRN HIGH PLAINS. SHEARING OF AN UPPER TROUGH TO THE SOUTH OF THE STRONGER WESTERLIES WILL CONTINUE ACROSS EASTERN PORTIONS OF THE SOUTHERN PLAINS INTO THE LOWER HALF OF THE MISSISSIPPI VALLEY...AS A SHARP UPPER RIDGE REMAINS STRONG ACROSS THE ERN STATES. ...GREAT LAKES REGION SWWD TO ERN NEB/NERN KS... AIR MASS IS PROGGED TO REMAIN VERY MOIST FROM THE WESTERN/CENTRAL GULF STATES NORTHWARD AHEAD OF A PRE-FRONTAL TROUGH INTO THE LOWER GREAT LAKES REGION. AN EXTENSIVE BAND OF SHOWERS/EMBEDDED THUNDERSTORMS SHOULD BE ONGOING AT 12Z SUNDAY ALONG THIS TROUGH FROM PARTS OF THE LOWER MS VALLEY NNEWD INTO WI/LOWER MI. DEEP LAYER ASCENT AHEAD OF SHEARING UPPER TROUGH/ALONG PRE-FRONTAL TROUGH WILL MAINTAIN THIS ACTIVITY EWD INTO THE LOWER TN/OH VALLEYS AND SRN GREAT LAKES REGION THROUGH THE PERIOD. DESPITE STRONGER WIND FIELDS AHEAD OF NORTH CENTRAL U.S. UPPER TROUGH... WEAK LAPSE RATES SHOULD PRECLUDE A SEVERE THREAT WITH THIS LEAD BAND OF CONVECTION. IN WAKE OF PRE-FRONTAL CONFLUENT ZONE...SURFACE HEATING JUST AHEAD OF A COLD FRONT SEEMS TO SUGGEST BEST POTENTIAL/FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT. THIS FRONT IS EXPECTED TO CURVE FROM THE UPPER GREAT LAKES REGION THROUGH THE NORTH CENTRAL PLAINS BY LATE SUNDAY AFTERNOON. ALTHOUGH MOISTURE WILL TEND TO BE LIMITED NEAR THIS BOUNDARY...SUFFICIENT DESTABILIZATION APPEARS LIKELY FOR AT LEAST SCATTERED THUNDERSTORMS. ENHANCED SHEAR BENEATH STRONG CYCLONIC MID LEVEL FLOW MAINLY OVER THE ERN EXTENT OF THE COLD FRONT /SRN WI TO ERN IA/ MAY ALLOW A FEW STORMS TO PRODUCE HAIL/ GUSTY WINDS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS. ACTIVITY SHOULD SPREAD SOUTHEASTWARD THROUGH LOWER GREAT LAKES AND PARTS OF THE MID MS VALLEY BEFORE DIMINISHING SUNDAY EVENING. FARTHER WEST...MODELS SUGGEST POTENTIAL FOR ELEVATED THUNDERSTORMS DEVELOPING SUNDAY EVENING ACROSS ERN NEB/WRN IA WITHIN INCREASING ZONE OF LOW LEVEL WAA ALONG NOSE OF STRENGTHENING SWLY LLJ. ELEVATED INSTABILITY AND EFFECTIVE BULK SHEAR SUGGEST POTENTIAL FOR A FEW STORMS TO PRODUCE HAIL...WITH ACTIVITY DEVELOPING SEWD INTO NERN KS/NRN MO SUNDAY NIGHT. ...LOWER MS VALLEY TO EAST TX... SURFACE HEATING WITHIN MOIST AIR MASS /SURFACE DEWPOINTS 70+ F/ FROM PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY AND BENEATH LINGERING MID-LEVEL COOL POCKET WILL RESULT IN FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/LOCALIZED SEVERE STORMS. WEAKENING FLOW FIELDS SUGGEST THIS ACTIVITY SHOULD BE MORE PULSE-TYPE WITH HAIL/GUSTY WINDS THE PRIMARY THREATS. ...ERN ORE/CENTRAL-SRN ID/SW MT... FORCING/SHEAR ASSOCIATED WITH A 40-50 KT MID-LEVEL JET STREAK IS EXPECTED TO ENHANCE CONVECTIVE POTENTIAL NEAR LOW/MID-LEVEL BAROCLINIC ZONE ACROSS PARTS OF ERN ORE/CENTRAL AND SRN ID LATE SUNDAY AFTERNOON/EVENING. MOISTURE WILL BE LIMITED...BUT LAPSE RATES WILL BECOME QUITE STEEP AND SUPPORTIVE OF AT LEAST WIDELY SCATTERED STORMS WITH POTENTIAL FOR MICROBURSTS. ..PETERS.. 06/17/2006  From swody2 at goshenarc.org Sun Jun 18 05:59:11 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 18 Jun 2006 01:59:11 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180556 SWODY2 SPC AC 180555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT SUN JUN 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS MON ACROSS PARTS OF THE NRN APPALACHIANS INTO NEW ENGLAND.... ...THERE IS A SLGT RISK OF SVR TSTMS LATE MON/MON NIGHT ACROSS PARTS OF THE NRN ROCKIES INTO THE NRN PLAINS AND PARTS OF THE MID MO VALLEY.... A HIGH LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD ACROSS THE NORTHEAST PACIFIC/ALASKA AND NORTHWEST CANADA. AND...MODELS INDICATE THAT THE SOUTHERN BRANCH OF THE ASSOCIATED SPLIT FLOW WILL REMAIN LARGELY ZONAL...AND GENERALLY NEAR OR JUST SOUTH THE CANADIAN/U.S. BORDER. A COUPLE OF BROADER SCALE TROUGHS...WITH ASSOCIATED SMALLER SCALE IMPULSES...ARE EMBEDDED WITHIN THIS REGIME...AND ARE PROGGED TO REMAIN PROGRESSIVE. IN TANDEM WITH TROUGHING IN THE NORTHERN STREAM...LEAD TROUGH IS FORECAST TO DEVELOP EAST SOUTHEAST OF THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES REGION MONDAY...THROUGH MUCH OF THE REMAINDER OF THE GREAT LAKES AND OHIO VALLEY BY EARLY TUESDAY. AS THIS OCCURS...AN UPSTREAM TROUGH IS FORECAST TO ADVANCE ACROSS THE NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES AND NORTHERN HIGH PLAINS...AHEAD OF A STRONG MID/UPPER JET STREAK NOSING ACROSS THE NORTHEAST PACIFIC TOWARD THE PACIFIC NORTHWEST COAST. ...GREAT LAKES/OHIO VALLEY INTO THE NORTHEAST... AHEAD OF MAIN UPPER TROUGH...CONFIDENCE IS GROWING THAT A SIGNIFICANT IMPULSE...FROM WEAKENING TROUGH NOW SOUTH OF MAIN BELT OF WESTERLIES...WILL ACCELERATE NORTHEASTWARD INTO THE UPPER OHIO VALLEY BY 12Z MONDAY...BEFORE CONTINUING INTO/THROUGH THE ST. LAWRENCE VALLEY/NORTHERN NEW ENGLAND. BELT OF STRONGER LOWER/MID- LEVEL FLOW /ON THE ORDER OF 30-40 KTS/ SEEMS LIKELY TO ACCOMPANY THIS FEATURE...ALONG WITH NARROW TONGUE OF VERY MOIST AIR.... INCLUDING SURFACE DEW POINTS AS HIGH AS 70F. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE WEAK...MODELS SUGGEST INFLUX OF MOISTURE AND DAYTIME HEATING WILL CONTRIBUTE TO MIXED LAYER CAPE OF 1000-2000 J/KG...FROM THE NORTH CENTRAL APPALACHIANS THROUGH THE HUDSON/ CHAMPLAIN VALLEY. ZONE OF ENHANCED MID-LEVEL FORCING IS EXPECTED TO BE SUFFICIENT FOR THE DEVELOPMENT OF A SOLIDIFYING CONVECTIVE LINE BY MONDAY AFTERNOON. AND...GIVEN POSSIBLE DESTABILIZATION AND FAVORABLE WIND FIELDS...POTENTIAL WILL EXIST FOR DAMAGING WINDS TO ACCOMPANY LOCALLY HEAVY RAINFALL WITH RELATIVELY FAST MOVING STORMS. ELSEWHERE...FORCING ON TAIL END OF MAIN...DIGGING UPPER TROUGH MAY SUPPORT ADDITIONAL SCATTERED VIGOROUS STORMS AHEAD OF COLD FRONT...THROUGH THE OHIO VALLEY LATE MONDAY AFTERNOON/EVENING. MOISTURE/LOW-LEVEL CONVERGENCE IN WAKE OF IMPULSE LIFTING THROUGH THE NORTHEAST IS UNCERTAIN...AND IT STILL APPEARS MOST PROBABLE THAT ANY SEVERE HAIL/WIND EVENTS WILL BE FAIRLY LOCALIZED AND LIMITED TO PERIOD NEAR/SHORTLY AFTER PEAK HEATING. ...NORTHERN ROCKIES THROUGH NORTHERN/CENTRAL PLAINS... MOISTURE RETURN IN DEVELOPING FAVORABLE UPSLOPE FLOW REGIME THROUGH THE HIGH PLAINS STILL APPEARS LIKELY TO BE SOMEWHAT MARGINAL FOR VIGOROUS CONVECTIVE DEVELOPMENT. HOWEVER...LAPSE RATES ARE EXPECTED TO BECOME STEEP AND SUPPORTIVE OF SEVERE HAIL/WIND...AS FORCING ASSOCIATED WITH OROGRAPHY AND APPROACHING TROUGH GENERATE DEEP CONVECTION. INITIATION IS EXPECTED BY LATE MONDAY AFTERNOON ACROSS THE MOUNTAINS OF SOUTHWEST MONTANA AND WYOMING...BEFORE SPREADING THROUGH SOUTHERN MONTANA AND NORTHEASTERN WYOMING...NEAR 40-50 KT MID-LEVEL JET STREAK...MONDAY EVENING. STRONG MID-LEVEL WARMING SOUTHEAST OF UPPER TROUGH...THROUGH MUCH OF THE NORTH CENTRAL PLAINS...WILL PROVIDE STRONG CAPPING. HOWEVER...EVENTUALLY...LOW/MID-LEVEL WARM ADVECTION ON EDGE OF CAP WILL PROBABLY SUPPORT AN EVOLVING CONVECTIVE CLUSTER AS MID-LEVEL JET NOSES INTO THE NORTHERN PLAINS MONDAY NIGHT. THIS STILL APPEARS MOST LIKELY NEAR THE NORTH DAKOTA/SOUTH DAKOTA BORDER AREA...WHERE SIZABLE LOW/MID-LEVEL TEMPERATURE DEW POINT SPREADS WILL CONTRIBUTE TO POTENTIAL FOR DAMAGING WIND GUSTS...IN ADDITION TO LARGE HAIL...DESPITE PRESENCE OF DEEPENING RADIATIONAL INVERSION LAYER. OTHER STORMS...PRIMARILY WITH LARGE HAIL POTENTIAL...APPEAR POSSIBLE LATE MONDAY NIGHT AS LIFT STRENGTHENS ON EDGE OF STRONGER CAPPING EAST OF THE MID MISSOURI VALLEY. ..KERR.. 06/18/2006  From swody2 at goshenarc.org Mon Jun 19 01:16:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 18 Jun 2006 21:16:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 181737 SWODY2 SPC AC 181736 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1236 PM CDT SUN JUN 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY FROM THE OH VALLEY TO NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY/MONDAY NIGHT ACROSS PARTS OF THE NRN ROCKIES INTO THE NRN PLAINS AND PARTS OF THE MID MO VALLEY... ...SYNOPSIS... AMPLIFIED NRN STREAM WILL REMAIN PROGRESSIVE THROUGH THE DAY 2 PERIOD...WHILE A SUB-TROPICAL RIDGE BUILDS EWD THROUGH THE PLAINS STATES. ONE LARGE SCALE TROUGH DEVELOPING SEWD ACROSS THE UPPER MS VALLEY AND ONTARIO DURING DAY 1 PERIOD WILL MOVE EWD THROUGH THE GREAT LAKES/OH VALLEY TO NERN STATES BY 12Z TUESDAY. UPSTREAM PACIFIC TROUGH IS PROGGED TO TRACK EWD ACROSS THE NRN INTERMOUNTAIN WEST REACHING THE WRN DAKOTAS LATE DAY 2. WEAKER IMPULSES...WITHIN SRN FRINGE OF STRONGER SWLY MID LEVEL FLOW EXPECTED TO EXTEND FROM THE GREAT BASIN TO NRN PLAINS...WILL TRACK OVER THE CENTRAL HIGH PLAINS BY LATE MONDAY AFTERNOON. ...GREAT LAKES/OH VALLEY INTO THE NORTHEAST... UPPER TROUGH JUST SOUTH OF MAIN BELT OF WESTERLIES IS PROGGED TO WEAKEN AS IT SPREADS E TOWARD THE ERN SEABOARD MONDAY. HOWEVER... STRONGER IMPULSE...WITHIN NRN EXTENT OF THIS TROUGH AND CURRENTLY LOCATED OVER THE MID MS VALLEY...IS EXPECTED TO ACCELERATE NEWD FROM THE UPPER OH VALLEY TO NRN NEW ENGLAND/ST LAWRENCE VALLEY. 30-40 KT SWLY LOW-MID LEVEL FLOW WILL LIKELY ACCOMPANY THIS FEATURE ACROSS THE NERN STATES. SURFACE FRONT ASSOCIATED WITH LEAD TROUGH WILL SPREAD EWD ACROSS NY/CENTRAL-SRN APPALACHIANS THROUGH MONDAY AFTERNOON REACHING VT TO ERN PA/MD AND CENTRAL VA BY 20/00Z. A BAND OF SHOWERS/EMBEDDED THUNDERSTORMS MAY BE ONGOING ACROSS THE LOWER GREAT LAKES/UPPER OH VALLEY TO ERN TN AT 12Z MONDAY ALONG THE FRONT. SURFACE HEATING DOWNSTREAM OF THIS ACTIVITY IS EXPECTED TO RESULT IN MODERATE INSTABILITY NEWD FROM CENTRAL PA BY EARLY MONDAY AFTERNOON. THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE/INTENSITY AS THE FRONT MOVES EWD INTO THE GREATER INSTABILITY WITH LINEAR FORCING SUGGESTING A SQUALL LINE WILL BE POSSIBLE WITH DAMAGING WINDS AND HAIL THE PRIMARY THREATS. SEVERE THREAT SHOULD SPREAD ENE INTO WRN/NRN NEW ENGLAND BEFORE WEAKENING MONDAY NIGHT WITH A DECREASE IN CONVECTIVE INSTABILITY. FARTHER WEST...SURFACE HEATING IS EXPECTED IN THE WAKE OF MORNING ACTIVITY ACROSS THE UPPER OH VALLEY AND ALONG/E OF A SECOND SURFACE FRONT ASSOCIATED WITH GREAT LAKES UPPER TROUGH. THIS FRONT SHOULD EXTEND FROM LOWER MI TO CENTRAL IL BY EARLY MONDAY AFTERNOON. A MID LEVEL IMPULSE TRACKING THROUGH BASE OF UPPER TROUGH WILL MOVE ACROSS OH VALLEY MONDAY AFTERNOON/EVENING. RESULTANT STEEPENING OF LAPSE RATES DUE TO SURFACE HEATING AND ADVECTION OF COLD MID LEVEL TEMPERATURES WITH IMPULSE WILL SUPPORT MODERATE INSTABILITY ACROSS THE OH VALLEY. ASCENT AHEAD OF IMPULSE WILL SUPPORT THUNDERSTORMS ALONG SECONDARY FRONT MONDAY AFTERNOON WITH ACTIVITY SPREADING EWD THROUGH THE OH VALLEY... REACHING SWRN NY/WRN PA AND WV MONDAY EVENING. 50 KT MID LEVEL JET ACCOMPANYING IMPULSE WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR STORM ORGANIZATION WITH DAMAGING WINDS/HAIL THE PRIMARY THREATS. ...NRN ROCKIES THROUGH NRN/CENTRAL PLAINS.... MOISTURE RETURN WITHIN UPSLOPE FLOW REGIME ALONG THE HIGH PLAINS IS EXPECTED TO BE MARGINAL WITH LOWER 60S SURFACE DEWPOINTS POTENTIALLY EXTENDING INTO WRN NEB/NWRN KS MONDAY AFTERNOON. DESPITE THIS LIMITING FACTOR...STEEPENING LAPSE RATES AND STRONG FORCING SPREADING EWD AHEAD OF THE APPROACHING PACIFIC UPPER TROUGH COMBINED WITH OROGRAPHIC ASCENT ARE EXPECTED TO GENERATE DEEP CONVECTION BY MID-LATE MONDAY AFTERNOON OVER SW MT/WRN WY. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THIS INITIAL ACTIVITY. WARM MID LEVEL TEMPERATURES TO THE S OF THE UPPER TROUGH AND WITHIN SUB-TROPICAL RIDGE ARE EXPECTED TO CAP THE PLAINS STATES INCLUDING ERN MT/WY THROUGH MUCH OF THE DAY. HOWEVER...LARGE DEWPOINT DEPRESSIONS WILL RESULT IN INVERTED-V THERMODYNAMIC PROFILES ALONG THE NRN HIGH PLAINS. THIS COMBINED WITH STRENGTHENING WLY MID LEVEL WINDS /50 KT/ SUGGEST THE SEVERE THREAT COULD TRANSITION INTO A GREATER DAMAGING WIND POTENTIAL AS THE PACIFIC FRONT SPREADS EWD THROUGH MT/NRN WY. FARTHER S ALONG THE LEE TROUGH...ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE INTO WRN NEB AS STRONG SURFACE HEATING WEAKENS THE CAP BY LATE MONDAY AFTERNOON. DAMAGING WINDS AND LARGE HAIL WILL BE POSSIBLE WITH THIS ACTIVITY. LOW/MID-LEVEL WARM ADVECTION ON EDGE OF CAP WILL PROBABLY SUPPORT AN EVOLVING CONVECTIVE CLUSTER ACROSS ND/SD AS MID-LEVEL JET NOSES INTO THE NORTHERN PLAINS MONDAY NIGHT. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THIS OVERNIGHT COMPLEX. OTHER STORMS...PRIMARILY WITH LARGE HAIL POTENTIAL...STILL APPEAR POSSIBLE LATE MONDAY NIGHT AS LIFT STRENGTHENS ON EDGE OF STRONGER CAPPING EAST OF THE MID MO VALLEY. ..PETERS.. 06/18/2006  From swody2 at goshenarc.org Mon Jun 19 05:39:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 01:39:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190538 SWODY2 SPC AC 190537 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE/TUE NIGHT ACROSS PARTS OF THE N CNTRL PLAINS INTO THE UPPER GREAT LAKES REGION.... MODELS CONTINUE TO INDICATE LITTLE CHANGE TO THE LARGE-SCALE PATTERN THROUGH THIS FORECAST PERIOD AND BEYOND. A SPLIT FLOW REGIME WILL PERSIST IN THE HIGHER LATITUDES...WITH THE SOUTHERN BELT REMAINING GENERALLY ZONAL ALONG/OR JUST SOUTH OF THE CANADIAN/U.S. BORDER. WITHIN THIS STREAM...A SERIES OF BROADER SCALE TROUGHS ARE FORECAST TO REMAIN PROGRESSIVE TUESDAY. THIS INCLUDES ONE PROGGED TO SHIFT EAST OF THE LOWER GREAT LAKES INTO NORTH ATLANTIC COASTAL AREAS...AND ANOTHER PROGGED EASTWARD ALONG THE CENTRAL CANADIAN/U.S. BORDER. ...N CNTRL PLAINS THRU THE UPPER GREAT LAKES REGION... STRONG DESTABILIZATION STILL APPEARS LIKELY BY EARLY TUESDAY ACROSS THE NORTH CENTRAL PLAINS/MID MISSOURI VALLEY REGION...WHERE BOUNDARY LAYER IS FORECAST TO MOISTEN CONSIDERABLY...BENEATH CAPPING MID-LEVEL THERMAL RIDGE NOSING NORTHEASTWARD OUT OF THE CENTRAL/SOUTHERN ROCKIES. SURFACE DEW POINTS ARE EXPECTED TO CLIMB THROUGH THE LOWER/MID 60S AS MID-LEVEL LAPSE RATES STEEPEN. THIS WILL CONTRIBUTE TO STRONG CONDITIONAL AND CONVECTIVE INSTABILITY...WHICH SHOULD YIELD MIXED LAYER CAPE ON THE ORDER OF 2000 TO 4000 J/KG BY PEAK HEATING TUESDAY AFTERNOON. VIGOROUS CONVECTIVE DEVELOPMENT COULD BE ONGOING AT 12Z TUESDAY IN FAVORABLE LOW/MID-LEVEL WARM ADVECTION REGIME ON NORTHERN/EASTERN PERIPHERY OF STRONGER CAP...FROM PARTS OF THE DAKOTAS SOUTHEASTWARD INTO IOWA. THIS ACTIVITY IS EXPECTED TO DEVELOP EASTWARD AND WEAKEN THROUGH THE DAY. THE FOCUS FOR PRIMARY CONVECTIVE DEVELOPMENT DURING THE LATE AFTERNOON...THEN...IS EXPECTED TO BE FORCING EAST OF WEAK FRONTAL WAVE...FORMING ON THE SOUTHERN FRINGE OF THE STRONGER WESTERLIES. THIS APPEARS MOST LIKELY FROM PARTS OF EASTERN NEBRASKA INTO CENTRAL IOWA. MODELS STILL INDICATE SEASONABLY STRONG WIND FIELDS WILL ACCOMPANY UPPER TROUGH THROUGH THE MID MISSOURI VALLEY...WITH THE NOSE OF A 30-40 KT SOUTHERLY LOW-LEVEL JET FORECAST BENEATH 40-50 KT WESTERLY MID-LEVEL FLOW...NEAR/EAST OF SURFACE WAVE. GIVEN PRESENCE OF LARGE CAPE...AND THERMODYNAMIC PROFILES SUPPORTING POTENTIAL FOR STRONG EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...CONDITIONS SEEM LIKELY TO FAVOR RAPID TRANSITION FROM SUPERCELLS TO AN EXPANDING SEVERE MESOSCALE CONVECTIVE SYSTEM... BENEATH RELATIVELY WEAK BUT DIVERGENT UPPER FLOW. STRONG DAMAGING WINDS AND LARGE HAIL ARE EXPECTED...AND A SIGNIFICANT COLD POOL COULD DEVELOP TUESDAY EVENING AS ACTIVITY SPREADS ACROSS THE CORN BELT INTO THE UPPER MISSISSIPPI VALLEY. THIS COULD REACH THE UPPER GREAT LAKES REGION WITH CONTINUING SEVERE POTENTIAL BY THE END OF THE FORECAST PERIOD. FARTHER TO THE SOUTH/WEST...MODELS ARE SUGGESTIVE THAT AN IMPULSE IN THE SUBTROPICAL STREAM COULD WEAKEN INHIBITION SUFFICIENTLY FOR INITIATION OF CONVECTION NEAR FRONT/PRE-FRONTAL TROUGH ACROSS EASTERN COLORADO INTO CENTRAL KANSAS BY EARLY TUESDAY EVENING. IF THIS OCCURS...ANOTHER CLUSTER OF STORMS PROBABLY WILL EVENTUALLY EVOLVE IN ENVIRONMENT FAVORABLE FOR DOWNBURSTS AND SOME HAIL. ...SOUTHERN MID ATLANTIC COASTAL AREAS INTO NEW ENGLAND... STRONGER LOW-LEVEL FLOW FIELDS ARE PROGGED TO LIFT AWAY FROM NORTH ATLANTIC COASTAL AREAS BY EARLY TUESDAY...WITH AN ASSOCIATED TONGUE OF HIGHER PRECIPITABLE WATER GENERALLY SHIFTING OFFSHORE. HOWEVER...LINGERING LOW-LEVEL MOISTURE MAY SUPPORT SUFFICIENT DESTABILIZATION WITH DAYTIME HEATING FOR LOCALIZED HAIL/WIND EVENTS IN SCATTERED AFTERNOON THUNDERSTORMS. ACTIVITY IS EXPECTED TO DEVELOP AHEAD OF MID-LEVEL TROUGH AXIS...NEAR SURFACE FRONT ADVANCING TOWARD COASTAL NEW ENGLAND AND THE LOWER HUDSON VALLEY...AND NEAR LEE SURFACE TROUGH ACROSS MIDDLE/NORTHERN ATLANTIC COASTAL AREAS. ..KERR.. 06/19/2006  From swody2 at goshenarc.org Mon Jun 19 17:43:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 13:43:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191739 SWODY2 SPC AC 191738 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 PM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY INTO CO... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NEW ENGLAND... ...MID MS VALLEY... NRN ROCKIES SHORTWAVE TROUGH WILL FLATTEN UPPER RIDGE FROM THE NRN/CNTRL PLAINS INTO THE MID MS VALLEY REGION TUESDAY. WLY FLOW IN ASSOCIATION WITH THIS FEATURE WILL MAINTAIN A STOUT CAP ACROSS THE CNTRL PLAINS MOST OF THE PERIOD. LATEST THINKING IS DAY1 CONVECTION ACROSS THE NRN HIGH PLAINS WILL PROGRESS INTO THE DAKOTAS EARLY IN THE PERIOD AIDED BY LOW LEVEL WARM ADVECTION THAT WILL BECOME FOCUSED OVER THE MID/UPPER MS VALLEY LATER IN THE DAY. ELEVATED CONVECTION SHOULD SPREAD/DEVELOP SEWD INTO PORTIONS OF MN/IA ALONG THE ERN EDGE OF THE STRONG PLAINS CAP. THIS ACTIVITY MAY GENERATE HAIL WHILE ROOTED ABOVE THE BOUNDARY LAYER...BUT WITHIN STEEP MID LEVEL LAPSE RATE PLUME. OF MORE CONCERN IS THE POTENTIAL FOR BOUNDARY LAYER THUNDERSTORM DEVELOPMENT LATER IN THE DAY AHEAD OF COLD FRONT. IT APPEARS STRONG LOW LEVEL HEATING WILL OCCUR ACROSS WRN IA/ERN NEB...WHICH WILL BE NECESSARY FOR THE REMOVAL OF INHIBITION...AND CONVECTION SHOULD EVOLVE BY LATE AFTERNOON WITHIN A POTENTIALLY VERY UNSTABLE AIRMASS. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUPERCELL STRUCTURES ARE LIKELY WITH VERY LARGE HAIL POSSIBLE. WITH TIME...STORM MERGERS MAY RESULT IN MCS EVOLUTION WHICH COULD LEAD TO A MORE ORGANIZED DAMAGING WIND THREAT AS ACTIVITY SPREADS SEWD TOWARD NRN IL DURING THE OVERNIGHT HOURS. ...ERN CO/KS... UPSLOPE FLOW IN THE WAKE OF SWD SAGGING FRONTAL BOUNDARY WILL ALLOW HIGHER RH BOUNDARY LAYER TO SPREAD WWD INTO NERN CO TUESDAY AFTERNOON. TAIL END OF PLAINS UPPER TROUGH WILL BRUSH THIS REGION ENHANCING LARGE SCALE ASCENT AND AIDING UPSLOPE COMPONENT INTO EAST SLOPES. THUNDERSTORMS WILL DEVELOP BY MID-LATE AFTERNOON AND SPREAD SEWD TOWARD WRN KS WITH MORE THAN ENOUGH SHEAR FOR SUPERCELLS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH COVERAGE/INTENSITY OF STORMS EXPECTED TO BE MODULATED BY THE DEGREE OF BOUNDARY LAYER MOISTURE THAT CAN RETURN TO THIS REGION BEFORE INITIATION. IF SUFFICIENT MOISTURE DOES RETURN...AN MCS COULD EASILY EVOLVE OVER THE CNTRL HIGH PLAINS TUESDAY NIGHT. ...NEW ENGLAND/MIDDLE ATLANTIC... TIMING OF UPPER TROUGH AND THE PROGRESSION OF ASSOCIATED LOW LEVEL WIND SHIFT WILL PLAY AN IMPORTANT ROLE IN DEEP CONVECTION ACROSS NEW ENGLAND DURING THE DAY2 PERIOD. LATEST NAM GUIDANCE SUGGEST LOW LEVEL CONFLUENCE ZONE WILL HAVE SHIFTED INTO CNTRL ME...STRETCHING SWWD INTO CNTRL MA BY 18Z..AND THIS IS SUPPORTED BY 12Z GFS. A NARROW AXIS OF MODEST INSTABILITY WILL EVOLVE ALONG THIS WIND SHIFT WHICH SHOULD SUPPORT ORGANIZED DEEP CONVECTIVE DEVELOPMENT BY MID DAY. RAPID BOUNDARY LAYER HEATING WILL STEEPEN LOW LEVEL LAPSE RATES AND FORECAST SHEAR PROFILES SUGGEST SUFFICIENT WLY FLOW TO ALLOW STORMS TO PROGRESS TOWARD COASTAL AREAS DURING THE AFTERNOON. LARGE HAIL/DAMAGING WINDS MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/19/2006  From swody2 at goshenarc.org Mon Jun 19 17:55:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 13:55:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191755 SWODY2 SPC AC 191753 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1253 PM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY INTO CO... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NEW ENGLAND... CORRECTED FOR THUNDER LINE IN THE SOUTHERN U.S. ...MID MS VALLEY... NRN ROCKIES SHORTWAVE TROUGH WILL FLATTEN UPPER RIDGE FROM THE NRN/CNTRL PLAINS INTO THE MID MS VALLEY REGION TUESDAY. WLY FLOW IN ASSOCIATION WITH THIS FEATURE WILL MAINTAIN A STOUT CAP ACROSS THE CNTRL PLAINS MOST OF THE PERIOD. LATEST THINKING IS DAY1 CONVECTION ACROSS THE NRN HIGH PLAINS WILL PROGRESS INTO THE DAKOTAS EARLY IN THE PERIOD AIDED BY LOW LEVEL WARM ADVECTION THAT WILL BECOME FOCUSED OVER THE MID/UPPER MS VALLEY LATER IN THE DAY. ELEVATED CONVECTION SHOULD SPREAD/DEVELOP SEWD INTO PORTIONS OF MN/IA ALONG THE ERN EDGE OF THE STRONG PLAINS CAP. THIS ACTIVITY MAY GENERATE HAIL WHILE ROOTED ABOVE THE BOUNDARY LAYER...BUT WITHIN STEEP MID LEVEL LAPSE RATE PLUME. OF MORE CONCERN IS THE POTENTIAL FOR BOUNDARY LAYER THUNDERSTORM DEVELOPMENT LATER IN THE DAY AHEAD OF COLD FRONT. IT APPEARS STRONG LOW LEVEL HEATING WILL OCCUR ACROSS WRN IA/ERN NEB...WHICH WILL BE NECESSARY FOR THE REMOVAL OF INHIBITION...AND CONVECTION SHOULD EVOLVE BY LATE AFTERNOON WITHIN A POTENTIALLY VERY UNSTABLE AIRMASS. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUPERCELL STRUCTURES ARE LIKELY WITH VERY LARGE HAIL POSSIBLE. WITH TIME...STORM MERGERS MAY RESULT IN MCS EVOLUTION WHICH COULD LEAD TO A MORE ORGANIZED DAMAGING WIND THREAT AS ACTIVITY SPREADS SEWD TOWARD NRN IL DURING THE OVERNIGHT HOURS. ...ERN CO/KS... UPSLOPE FLOW IN THE WAKE OF SWD SAGGING FRONTAL BOUNDARY WILL ALLOW HIGHER RH BOUNDARY LAYER TO SPREAD WWD INTO NERN CO TUESDAY AFTERNOON. TAIL END OF PLAINS UPPER TROUGH WILL BRUSH THIS REGION ENHANCING LARGE SCALE ASCENT AND AIDING UPSLOPE COMPONENT INTO EAST SLOPES. THUNDERSTORMS WILL DEVELOP BY MID-LATE AFTERNOON AND SPREAD SEWD TOWARD WRN KS WITH MORE THAN ENOUGH SHEAR FOR SUPERCELLS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH COVERAGE/INTENSITY OF STORMS EXPECTED TO BE MODULATED BY THE DEGREE OF BOUNDARY LAYER MOISTURE THAT CAN RETURN TO THIS REGION BEFORE INITIATION. IF SUFFICIENT MOISTURE DOES RETURN...AN MCS COULD EASILY EVOLVE OVER THE CNTRL HIGH PLAINS TUESDAY NIGHT. ...NEW ENGLAND/MIDDLE ATLANTIC... TIMING OF UPPER TROUGH AND THE PROGRESSION OF ASSOCIATED LOW LEVEL WIND SHIFT WILL PLAY AN IMPORTANT ROLE IN DEEP CONVECTION ACROSS NEW ENGLAND DURING THE DAY2 PERIOD. LATEST NAM GUIDANCE SUGGEST LOW LEVEL CONFLUENCE ZONE WILL HAVE SHIFTED INTO CNTRL ME...STRETCHING SWWD INTO CNTRL MA BY 18Z..AND THIS IS SUPPORTED BY 12Z GFS. A NARROW AXIS OF MODEST INSTABILITY WILL EVOLVE ALONG THIS WIND SHIFT WHICH SHOULD SUPPORT ORGANIZED DEEP CONVECTIVE DEVELOPMENT BY MID DAY. RAPID BOUNDARY LAYER HEATING WILL STEEPEN LOW LEVEL LAPSE RATES AND FORECAST SHEAR PROFILES SUGGEST SUFFICIENT WLY FLOW TO ALLOW STORMS TO PROGRESS TOWARD COASTAL AREAS DURING THE AFTERNOON. LARGE HAIL/DAMAGING WINDS MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/19/2006  From swody2 at goshenarc.org Tue Jun 20 17:32:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 20 Jun 2006 13:32:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201731 SWODY2 SPC AC 201730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT TUE JUN 20 2006 VALID 211200Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF THE GREAT LAKES/OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CENTRAL PLAINS... ...GREAT LAKES/OH VALLEY... MODELS ARE IN GENERAL AGREEMENT WITH SPEED/MOVEMENT OF SRN CANADA/NRN PLAINS TROUGH INTO THE GREAT LAKES REGION DURING THE DAY WEDNESDAY. THIS FEATURE WILL INDUCE HEIGHT FALLS ACROSS NRN WI/U.P. OF MI WHILE WLY FLOW...H5 SPEEDS ON THE ORDER OF 50-60KT...SHOULD INCREASE ALONG SRN FRINGES OF THIS FEATURE FROM SRN IA INTO SRN ONTARIO. THIS INCREASING WLY FLOW ALOFT...COMBINED WITH RECOVERING/MOISTENING BOUNDARY LAYER WILL ENHANCE THE PROSPECT FOR POTENTIALLY SIGNIFICANT THUNDERSTORM EVENT DAY2...WITH THE POSSIBILITY FOR LONG-LIVED ORGANIZED DAMAGING WINDS. LATEST THINKING IS SUSTAINED LOW LEVEL WARM ADVECTION WILL DRIVE EARLY MORNING CONVECTION ACROSS THE GREAT LAKES INTO THE OH VALLEY WITH BOUNDARY LAYER HEATING/DESTABILIZATION EXPECTED IN THE WAKE OF THIS ACTIVITY FROM LOWER MI...WSWWD INTO ERN IA BY EARLY AFTERNOON. IT APPEARS CONVECTION SHOULD DEVELOP/INTENSIFY BY MID DAY...POSSIBLY ALONG LEADING EDGE OF LATE DAY1 PLAINS CLUSTER...OVER PORTIONS OF IA/WI/NRN IL. THIS ACTIVITY SHOULD SEE UPSCALE GROWTH BENEATH DEEP WLY FLOW WITH SUSTAINED SWLY LLJ AIDING INFLOW. WITH TIME BOW TYPE STRUCTURES SHOULD EVOLVE WHICH WILL MOVE QUICKLY EWD INTO LOWER MI/NRN IND/OH BY LATE AFTERNOON. DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREAT...ESPECIALLY IF LONG-LIVED MCS CAN EVOLVE ACROSS THIS REGION. ...CENTRAL PLAINS... SEVERAL WEAK VORT MAXIMA EMBEDDED WITHIN WNWLY FLOW SHOULD APPROACH THE CNTRL ROCKIES WHICH SHOULD AID ELY LOW LEVEL COMPONENT ACROSS SERN WY/ERN CO. 700MB THERMAL GRADIENT HAS TIGHTENED ACROSS THIS REGION WITH MUCH COOLER TEMPERATURES SAGGING SWD TOWARD I-70. THIS COOLING ALOFT...COMBINED WITH UPSLOPE FLOW WILL UNDOUBTEDLY ENHANCE CONVECTIVE POTENTIAL BY MID-LATE AFTERNOON OVER NERN CO. SUPERCELLS SHOULD EVOLVE QUICKLY ONCE BOUNDARY LAYER WARMS THEN SPREAD SEWD ACROSS THE PLAINS TOWARD WRN KS. SUFFICIENT LOW LEVEL MOISTURE SHOULD BE IN PLACE ACROSS THE PLAINS BY STORM MATURATION FOR ISOLATED TORNADOES AND VERY LARGE HAIL. THIS REGION MAY NEED TO BE UPGRADED IN LATER OUTLOOKS...ESPECIALLY IF AN IDENTIFIABLE ORGANIZED SHORTWAVE TROUGH APPROACHES THIS REGION NEAR CONVECTIVE CLIMAX. ..DARROW.. 06/20/2006  From swody2 at goshenarc.org Wed Jun 21 05:33:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 21 Jun 2006 01:33:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210532 SWODY2 SPC AC 210531 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1231 AM CDT WED JUN 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MUCH OF THE LWR GREAT LAKES/OHIO VALLEY REGION INTO THE SOUTH CENTRAL HIGH PLAINS.... WHILE THE SOUTHERN BRANCH OF HIGHER LATITUDE SPLIT FLOW PATTERN REMAINS GENERALLY ZONAL NEAR OR JUST SOUTH OF THE CANADIAN U.S. BORDER THROUGH THIS FORECAST PERIOD...MODELS CONTINUE TO INDICATE THAT SIGNIFICANT AMPLIFICATION WILL OCCUR IN THE NORTHERN STREAM ...ACROSS EASTERN CANADA. THIS SHOULD BE WELL UNDERWAY BY 12Z THURSDAY...WHEN A STRONG SHORT WAVE TROUGH IS FORECAST TO BE IN THE PROCESS OF DIGGING THROUGH SOUTHERN HUDSON BAY/NORTHERN ONTARIO. IN ADVANCE OF THE NORTHERN BRANCH SYSTEM...WHICH IS PROGGED TO TURN EASTWARD ACROSS ONTARIO INTO WESTERN QUEBEC THURSDAY/THURSDAY NIGHT....A SIGNIFICANT SOUTHERN BRANCH IMPULSE WILL CONTINUE LIFTING ACROSS QUEBEC THROUGH THE CANADIAN MARITIMES. AS THIS OCCURS...STRONGER SOUTHERLY LOW-LEVEL FLOW FIELDS WILL LIFT OUT OF THE NORTHEAST...BUT WESTERLY LOWER/MID TROPOSPHERIC FLOW WILL INTENSIFY AHEAD OF SIGNIFICANT SURFACE COLD FRONT ADVANCING THROUGH SOUTHEASTERN CANADA. THIS WILL GENERALLY OCCUR ACROSS THE LOWER GREAT LAKES INTO NORTHERN NEW ENGLAND...BUT THE SOUTHERN FRINGE OF MORE MODERATE WESTERLIES COULD EXTEND AS FAR SOUTH/WEST AS NORTHERN PARTS OF THE LOWER OHIO VALLEY THROUGH MUCH OF THE PERIOD. ACROSS THE WEST...ANOTHER MID-LEVEL JET STREAK/IMPULSE PROGRESSING ACROSS THE NORTHERN INTERMOUNTAIN REGION/ROCKIES APPEARS LIKELY TO BE INCONSEQUENTIAL TO SIGNIFICANT CONVECTIVE DEVELOPMENT DURING THIS PERIOD. BUT...AN IMPULSE IN THE WEAKER SUBTROPICAL STREAM TO THE SOUTH/EAST COULD ENHANCE CONVECTIVE POTENTIAL TO THE LEE OF THE SOUTH CENTRAL ROCKIES. ...MIDDLE MISSISSIPPI VALLEY EASTWARD THROUGH THE NORTHEAST... CONSIDERABLE UNCERTAINTIES EXIST. HOWEVER...IT APPEARS MOST PROBABLE THAT SUBSTANTIAL CONVECTIVE CLUSTER ASSOCIATED WITH INITIAL SOUTHERN BRANCH IMPULSE WILL WEAKEN AS IT PROGRESSES ACROSS THE HUDSON/CHAMPLAIN VALLEY THROUGH NORTHERN NEW ENGLAND EARLY THURSDAY. LOW-LEVEL MOISTURE IN ADVANCE OF SYSTEM ACROSS THIS REGION DOES NOT APPEAR LIKELY TO MAINTAIN VIGOROUS CONVECTION. BUT...MOISTENING/DAYTIME HEATING ACROSS THE NORTH CENTRAL APPALACHIANS...AND THE URBAN CORRIDOR FROM WASHINGTON D.C./BALTIMORE THROUGH NEW YORK CITY...COULD BE SUFFICIENT TO SUPPORT NEW STRONG STORMS ON THE LEADING EDGE OF CONVECTIVELY GENERATED COLD POOL...POSSIBLY BY EARLY AFTERNOON. IN THE WAKE OF WEAKENING CONVECTIVE SYSTEM...DOUBTS ARE INCREASING CONCERNING LIKELIHOOD OF SIGNIFICANT DESTABILIZATION FROM PARTS OF NORTHERN NEW YORK INTO NEW ENGLAND...AHEAD OF STRONG COLD FRONT WHICH COULD ADVANCE INTO THE LOWER GREAT LAKES/ST. LAWRENCE VALLEY AS EARLY AS LATE THURSDAY AFTERNOON. IT NOW APPEARS MOST LIKELY THAT COMPOSITE OUTFLOW BOUNDARY/PRE-FRONTAL CONFLUENT ZONE WILL BE THE FOCUS FOR PRIMARY CONVECTIVE DEVELOPMENT. THIS FEATURE IS EXPECTED TO STALL NEAR OR JUST SOUTH OF THE NEW YORK/PENNSYLVANIA BORDER...SOUTHWESTWARD THROUGH THE MIDDLE MISSISSIPPI VALLEY... BEFORE SLOWLY ADVANCING SOUTHWARD AS CONVECTION INCREASES LATE THURSDAY/THURSDAY NIGHT. ACTIVITY...PARTICULARLY ACROSS THE OHIO VALLEY/SOUTHERN GREAT LAKES...COULD BE ENHANCED BY A SHEARING SUBTROPICAL STREAM IMPULSE...GRADUALLY ACCELERATING OUT OF THE CENTRAL PLAINS. SEVERAL CLUSTERS OF STORMS APPEAR POSSIBLE...IN THERMODYNAMIC ENVIRONMENT WITH RELATIVELY STEEP LAPSE RATES AND MIXED LAYER CAPE IN EXCESS OF 2000 J/KG. MOMENTUM ON SOUTHERN FRINGE OF WESTERLIES IS EXPECTED TO SUPPORT STORM MOTIONS OF 30-35+ KT...WHICH SHOULD CONTRIBUTE TO DAMAGING WIND POTENTIAL...IN ADDITION TO LARGE HAIL. ...SOUTH CENTRAL PLAINS... MOIST UPSLOPE FLOW IN WAKE OF COMPOSITE OUTFLOW BOUNDARY ADVANCING SOUTHWARD TO THE LEE OF THE CENTRAL ROCKIES WILL CONTRIBUTE TO LARGE SCALE ASCENT/DESTABILIZATION IN STEEP LAPSE RATE ENVIRONMENT. THIS IS EXPECTED TO SUPPORT CONVECTIVE DEVELOPMENT OFF THE HIGHER TERRAIN LATE THURSDAY AFTERNOON. FLOW WILL BE RATHER WEAK...BUT VEERING WINDS WITH HEIGHT BENEATH NORTHWESTERLY MID-LEVEL FLOW MAY PROVIDE SUFFICIENT DEEP LAYER SHEAR FOR MID-LEVEL UPDRAFT ROTATION IN STRONGER STORMS. AIDED BY WEAK UPPER IMPULSE...ACTIVITY COULD CONSOLIDATE INTO ANOTHER MESOSCALE CONVECTIVE SYSTEM WITH ISOLATED DAMAGING WIND GUSTS...IN ADDITION TO HAIL...AS IT PROGRESSES INTO/THROUGH THE TEXAS PANHANDLE REGION THURSDAY NIGHT. ..KERR.. 06/21/2006  From swody2 at goshenarc.org Wed Jun 21 17:25:09 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 21 Jun 2006 13:25:09 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211724 SWODY2 SPC AC 211723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CDT WED JUN 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/SRN PLAINS...NEWD TO PORTIONS OF WRN NEW ENGLAND... ...SYNOPSIS... A CONVECTIVELY-ACTIVE DAY APPEARS TO BE SHAPING UP FOR MUCH OF THE COUNTRY FROM THE CNTRL/SRN HIGH PLAINS...NEWD ALONG ADVANCING FRONTAL ZONE ACROSS THE OH VALLEY INTO PORTIONS OF NEW ENGLAND. THUNDERSTORMS...AND ULTIMATELY THEIR INTENSITY...WILL BE MODULATED BY AVAILABLE BUOYANCY WHICH WILL BE SIGNIFICANTLY IMPACTED BY DAY1 CONVECTIVE PROCESSES. MULTIPLE THUNDERSTORM COMPLEXES...MOST IN THE DECAYING STAGES...WILL BE ONGOING AT THE START OF THE PERIOD ALONG THE FRONTAL ZONE. THIS ACTIVITY WILL UNDOUBTEDLY FORCE OUTFLOW BOUNDARIES INTO THE WARM SECTOR WHICH WILL SERVE AS THE FOCUS FOR RENEWED DAYTIME DEVELOPMENT. LATEST THINKING IS THE GREATEST PROSPECT FOR BOUNDARY LAYER RECOVERY/HEATING WILL OCCUR ACROSS THE MID MS VALLEY AND OH VALLEY REGION...AS WELL AS PORTIONS OF THE SRN HIGH PLAINS. GIVEN THE 30-40KT 6KM SWLY FLOW ALOFT...ANY STORMS THAT DEVELOP ACROSS THE OH VALLEY SHOULD OBTAIN AT LEAST ORGANIZED MULTI-CELL CHARACTERISTICS. DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT WITH THIS ACTIVITY...AS WELL AS DOWNSTREAM CONVECTION ACROSS NY INTO PORTIONS OF WRN NEW ENGLAND. UPSTREAM...SFC FRONT SHOULD DRIVE SOUTH ACROSS THE HIGH PLAINS AS PRESSURES RISE OVER NEB...PARTLY ENHANCED BY OVERNIGHT CONVECTION. UPSLOPE FLOW COMPONENT INTO ERN CO...SWD INTO THE TX PANHANDLE WILL FORCE MOISTURE INTO A REGION THAT WILL SEE STRONG SUNSHINE AND RAPID DESTABILIZATION. ALTHOUGH MID-HIGH LEVEL NWLY FLOW WILL NOT BE THAT STRONG...DIRECTIONAL SHEAR WILL PROVE MORE THAN ADEQUATE FOR ORGANIZED UPDRAFTS...A FEW OF WHICH MAY ROTATE. WEAKENING CAP...BUT STEEP LAPSE RATES WILL SUPPORT LARGE HAIL. ALTHOUGH MODEST SEVERE PROBABILITIES WILL BE MAINTAINED FOR THIS OUTLOOK DUE TO THE COMPLEXITIES OF DAY1 CONVECTION...LATER OUTLOOKS MAY BE ABLE TO DISCERN WITH MORE CERTAINTY REGIONS FOR POTENTIAL UPGRADES LATER TONIGHT. ..DARROW.. 06/21/2006  From swody2 at goshenarc.org Thu Jun 22 05:18:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 22 Jun 2006 01:18:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220518 SWODY2 SPC AC 220516 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1216 AM CDT THU JUN 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FRI/EARLY FRI EVE FROM PARTS OF SRN NEW ENGLAND AND THE NRN MID ATLC COAST THRU THE OHIO VLY AND OZARK PLATEAU.... ...THERE IS A SLGT RISK OF SVR TSTMS FRI/EARLY FRI EVE ACROSS PARTS OF THE N CNTRL PLAINS.... MODELS INDICATE THAT A VIGOROUS NORTHERN BRANCH SHORT WAVE TROUGH...DIGGING THROUGH ONTARIO/QUEBEC TODAY...WILL QUICKLY LIFT OUT OF QUEBEC THROUGH THE CANADIAN MARITIMES DURING THIS FORECAST PERIOD. AS THIS OCCURS...LINGERING BELT OF CYCLONIC MID-LEVEL FLOW ACROSS MUCH OF THE GREAT LAKES/OHIO VALLEY INTO THE NORTHEAST WILL GRADUALLY BEGIN TO WEAKEN. STRONGER WESTERLIES...IN GENERAL...WILL CONTINUE TO RETREAT NORTH OF THE CANADIAN/U.S. BORDER FRIDAY...AS AN UPPER RIDGE BUILDS ACROSS THE WESTERN STATES...INTO THE CANADIAN ROCKIES. HOWEVER...ONE MORE FAIRLY SIGNIFICANT SOUTHERN STREAM SHORT WAVE TROUGH IS FORECAST TO DIG AROUND NORTHEASTERN PERIPHERY OF RIDGE...ACROSS THE NORTHERN PLAINS. AND...MODELS SUGGEST THAT WEAK MID-LEVEL TROUGHING ALREADY PRESENT ACROSS THE CENTRAL PLAINS...ON THE SOUTHERN FRINGE OF THE WESTERLIES...WILL ACCELERATE EASTWARD TOWARD THE SOUTHERN APPALACHIANS. AS THIS OCCURS...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST STATES WILL WEAKEN...AND A NARROW BELT OF MODERATE MID-LEVEL FLOW MAY SHIFT EAST OF THE OHIO VALLEY THROUGH THE NORTHERN MID ATLANTIC STATES BY THE PEAK HEATING HOURS. ...SRN NEW ENGLAND/NRN MID ATLANTIC THRU OH VLY/OZARK PLATEAU... A FAIRLY SIGNIFICANT COLD FRONT ASSOCIATED WITH THE NORTHERN BRANCH TROUGH APPEARS LIKELY TO BE IN THE PROCESS OF ADVANCING SOUTH/EAST OF THE LOWER GREAT LAKES AND ST. LAWRENCE VALLEY BY 12Z FRIDAY. THIS FRONT MAY CONTINUE SOUTHWARD INTO/THROUGH THE NORTHERN MID ATLANTIC COAST AND MUCH OF THE OHIO VALLEY BY THE END OF THE FORECAST PERIOD...BEFORE BEGINNING TO WEAKEN. THE FRONT LIKELY WILL BE PRECEDED BY A WEAK CONFLUENT ZONE OR COMPOSITE OUTFLOW BOUNDARY...ASSOCIATED WITH EXTENSIVE CONVECTIVE DEVELOPMENT TODAY...WHICH IS EXPECTED TO ALREADY EXTEND ACROSS THE NORTHERN MID ATLANTIC COAST STATES AND OHIO VALLEY INTO THE OZARK PLATEAU BY 12Z FRIDAY. WITH PERHAPS THE EXCEPTION OF SOUTHERN NEW ENGLAND...THIS PRE-FRONTAL BOUNDARY IS EXPECTED TO BECOME THE PRIMARY FOCUS FOR NEW CONVECTIVE DEVELOPMENT LATE FRIDAY MORNING AND AFTERNOON. THOUGH CLOUD COVER COULD BE CONSIDERABLE...ENOUGH HEATING OF MOIST BOUNDARY LAYER WITH UPPER 60S+ SURFACE DEW POINTS IS EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE UP TO AROUND 2000 J/KG. AS INHIBITION WEAKENS... THUNDERSTORM ACTIVITY IS EXPECTED TO BECOME NUMEROUS IN WEAK TO MODERATELY SHEARED WESTERLY MEAN FLOW REGIME. HAIL WILL BE POSSIBLE IN STRONGER CELLS...AND 30 KT MID LEVEL FLOW MAY BE ENOUGH TO ENHANCE STORM MOTIONS AND DOWNBURST POTENTIAL. ACTIVITY ACROSS MOST AREAS WILL PROBABLY WEAKEN RELATIVELY QUICKLY FRIDAY EVENING WITH LOSS OF DAYTIME HEATING. ...ROCKIES INTO PLAINS... COMPOSITE OUTFLOW SLOWLY ADVANCING THROUGH THE SOUTH CENTRAL PLAINS...AND MOIST UPSLOPE FLOW IN THE LEE OF THE ROCKIES TO THE NORTH WILL SUPPORT SCATTERED THUNDERSTORM ACTIVITY FRIDAY AFTERNOON AND EVENING. VEERING WINDS WITH HEIGHT BENEATH WEAK NORTHWESTERLY FLOW MAY CONTRIBUTE TO SUFFICIENT SHEAR FOR MID-LEVEL UPDRAFT ROTATION ACROSS MUCH OF THE CENTRAL/NORTHERN HIGH PLAINS. COVERAGE OF THIS ACTIVITY MAY BECOME MOST CONCENTRATED DURING THE LATE AFTERNOON FROM SOUTHEAST MONTANA/EASTERN WYOMING INTO THE WESTERN DAKOTAS...ASSOCIATED WITH WARM ADVECTION REGIME DOWNSTREAM OF APPROACHING SHORT WAVE. THIS FORCING WILL SPREAD SOUTHEASTWARD FRIDAY EVENING...BUT DUE TO MARGINAL LOW-LEVEL MOISTURE AND LIKELIHOOD OF QUICK RADIATIONAL SURFACE COOLING...SEVERE THREAT PROBABLY WILL NOT LAST LONG AFTER DARK. ..KERR.. 06/22/2006  From swody2 at goshenarc.org Thu Jun 22 17:24:50 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 22 Jun 2006 13:24:50 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221724 SWODY2 SPC AC 221723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CDT THU JUN 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TN VALLEY TO SOUTHERN NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS... ...TN VALLEY TO SRN NEW ENGLAND... ANOTHER VERY ACTIVE CONVECTIVE EVENT WILL OCCUR DURING THE DAY2 PERIOD WITH A SLIGHT SEWD DISPLACEMENT INTO THE TN VALLEY...STRETCHING INTO SRN NEW ENGLAND. MODELS ARE IN GENERAL AGREEMENT WITH EWD MOVEMENT OF LONGWAVE TROUGH AXIS INTO THE GREAT LAKES WHICH WILL FORCE A ZONE OF MODEST SWLY FLOW ALOFT FROM KY INTO ME. LARGE SCALE PROCESSES SUGGEST SYNOPTIC FRONTAL ZONE WILL SAG SEWD INTO THIS REGION...AUGMENTED BY CONVECTIVE OUTFLOW FROM THURSDAY NIGHT CONVECTION. IT APPEARS ONE OR MORE WEAKENING MCS/S WILL BE ONGOING AT THE BEGINNING OF THE PERIOD...THE MOST LIKELY REGION WILL BE SOMEWHERE BETWEEN SRN IL INTO SWRN OH. ADDITIONAL WEAKER ACTIVITY MAY BE SCATTERED ALONG/NORTH OF THE BOUNDARY INTO UPSTATE NY. RAPID BOUNDARY LAYER WARMING ACROSS THE WARM SECTOR...COMBINED WITH ROUGHLY 30-40KT 6KM FLOW ALOFT...WILL RESULT IN RAPID INTENSIFICATION/EXPANSION OF MULTI-CELL THUNDERSTORM CLUSTERS BY MID DAY FROM KY/TN...NEWD INTO SRN NEW ENGLAND. DAMAGING WINDS AND HAIL ARE THE MOST LIKELY SEVERE THREATS WITH THIS ACTIVITY. ...NORTHERN/CENTRAL PLAINS... 12Z MODELS ARE FAIRLY CONSISTENT WITH UPPER RIDGE FLATTENING OVER THE NRN ROCKIES AS SPEED MAX/SHORTWAVE TROUGH TURNS SEWD AND DIGS TOWARD THE CNTRL PLAINS LATE IN THE PERIOD. THIS FEATURE WILL ENHANCE LOW LEVEL WARM ADVECTION ACROSS THE CNTRL HIGH PLAINS AS SELY FLOW RESPONDS TO WEAK HEIGHT FALLS AND HEATING IN THE LEE OF THE MT/WY HIGH TERRAIN. VERY STEEP LAPSE RATES WILL DEVELOP BENEATH THERMAL TROUGH CREATING A FAVORABLE ENVIRONMENT FOR ORGANIZED DEEP CONVECTION. SCATTERED THUNDERSTORMS SHOULD DEVELOP NEAR THE BLACK HILLS BY LATE AFTERNOON WITH SEWD DEVELOPMENT/MOVEMENT EXPECTED TOWARD NCNTRL NEB AFTER DARK. OTHER ISOLATED SEVERE STORMS ARE POSSIBLE SWD INTO PORTIONS OF NERN CO...ALTHOUGH FORCING ACROSS THIS REGION WILL BE SOMEWHAT WEAKER. LARGE HAIL IS THE MOST LIKELY SEVERE THREAT WITH SUPERCELLS THAT EVOLVE ACROSS THIS REGION. ..DARROW.. 06/22/2006  From swody2 at goshenarc.org Fri Jun 23 05:52:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 23 Jun 2006 01:52:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230551 SWODY2 SPC AC 230550 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CDT FRI JUN 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...SYNOPSIS... SLIGHT AMPLIFICATION OF LONG WAVE PATTERN IS FORECAST DURING THE DAY TWO PERIOD WITH PRIMARY LARGE-SCALE FEATURES BEING UPPER LOW OVER ERN CANADA AND UPPER HIGH OVER THE GREAT BASIN. WITHIN THIS BROADER PATTERN...SEVERAL WEAK IMPULSES CURRENTLY OVER WRN CANADA ARE FORECAST TO CONSOLIDATE INTO A MORE INTENSE...AMPLIFYING SHORT WAVE TROUGH WHICH WILL DIG SEWD FROM THE NRN PLAINS AND UPPER MS VALLEY INTO THE UPPER MIDWEST SATURDAY AND SATURDAY NIGHT. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO UPPER MS VALLEY SHORT WAVE TROUGH WILL GENERALLY DEVELOP SEWD FROM CNTRL OR SRN MN INTO SRN WI OR NRN IL BY SATURDAY NIGHT WITH TRAILING COLD FRONT SHIFTING SWD THROUGH THE CNTRL INTO SRN PLAINS. IN THE E...FRONTAL SYSTEM WILL PUSH SEWD THROUGH THE SRN NEW ENGLAND AND THE MIDDLE ATLANTIC STATES...WITH SRN EXTENSION OF THIS BOUNDARY REMAINING MORE QUASI-STATIONARY OVER THE CNTRL/SRN APPALACHIANS OR ADJACENT PIEDMONT REGION. ...CNTRL/SRN HIGH PLAINS... ERN EXTENSION OF HIGH TERRAIN STEEP LAPSE RATES WILL REMAIN CO-LOCATED WITH WRN EDGE OF LOW-LEVEL MOIST AXIS WITH MLCAPES INCREASING TO 1000-1500 J/KG BY AFTERNOON OVER ERN CO/WRN KS INTO THE TX/OK PNHDLS. TSTMS WILL BECOME INCREASINGLY LIKELY BY MID/LATE AFTERNOON FROM SERN WY SWD TO THE RATON MESA OWING TO INCREASED LOW-LEVEL OROGRAPHIC FORCING AND PERHAPS SOME DEEPER ASCENT ASSOCIATED WITH A SERIES OF WEAK IMPULSES APPROACHING FROM THE NW. FORECAST SOUNDINGS INDICATE ELY/NELY LOW-LEVEL WINDS VEERING TO NWLY AT 20-30 KTS IN THE MID-LEVELS...RESULTING IN SUFFICIENT DEEP-LAYER SHEAR FOR ORGANIZED/ROTATING STORMS CAPABLE OF MAINLY LARGE HAIL AND ISOLATED DAMAGING WINDS. DIURNAL STORMS SHOULD GROW UPSCALE INTO ONE OR MORE MCS/S SATURDAY NIGHT WITH A WIND/HAIL THREAT DEVELOPING SEWD INTO WRN KS AND THE TX/OK PNHDLS. ...MN/IA/WI/IL... CLUSTERS OF TSTMS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD WITHIN ZONE OF DEEP-LAYER FORCING FOR ASCENT AHEAD OF INTENSIFYING SHORT WAVE TROUGH DIGGING SEWD. THOUGH SURFACE FRONT WILL REMAIN ON IMMEDIATE BACKSIDE OF ANTICYCLONE OVER THE CNTRL GREAT LAKES...RESIDUAL LOW-LEVEL MOISTURE AND EVAPOTRANSPIRATION SHOULD SUPPORT DEWPOINTS IN THE MID/UPPER 60S WITH MLCAPES OF 1000-1500 J/KG. WHILE ISOLATED SEVERE STORMS CAPABLE OF HIGH WINDS/HAIL WILL BE POSSIBLE NEAR SURFACE LOW AND ASSOCIATED FRONT...IT APPEARS THAT WEAK LAPSE RATES AND ONLY MODEST SHEAR /20-30 KTS THROUGH THE LOWEST 6 KM AGL/ WILL PRECLUDE A MORE ORGANIZED SEVERE WEATHER THREAT. ...MIDDLE ATLANTIC STATES INTO THE SRN APPALACHIANS... HERE TOO...TSTMS SHOULD BE FAIRLY WIDESPREAD SATURDAY INTO SATURDAY NIGHT ALONG SURFACE FRONT WITHIN MOIST /I.E. DEWPOINTS IN THE UPPER 60S TO MID 70S/ AND WEAKLY CAPPED ENVIRONMENT. TROPOSPHERIC WINDS WILL REMAIN RELATIVELY WEAK...THOUGH THE MODERATE INSTABILITY AND MOIST CONDITIONS MAY SUPPORT ISOLATED WET MICROBURST EVENTS. ..MEAD.. 06/23/2006  From swody2 at goshenarc.org Fri Jun 23 17:30:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 23 Jun 2006 13:30:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231730 SWODY2 SPC AC 231729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI JUN 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH PLAINS... ...CENTRAL/SRN HIGH PLAINS... UPPER RIDGE WILL HOLD OVER THE GREAT BASIN THROUGH DAY2 ALLOWING SHORTWAVE TROUGH DROPPING INTO THE MID MS VALLEY TO STRENGTHEN NNWLY FLOW ACROSS THE PLAINS. THIS FLOW REGIME WILL CONTINUE TO GENERATE ORGANIZED CONVECTION WITHIN UPSLOPE PATTERN UNTIL BOUNDARY LAYER MOISTURE IS REDUCED ACROSS THE HIGH PLAINS. THUNDERSTORM COMPLEX WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD OVER PORTIONS OF NEB/NRN KS. HOWEVER...WEAK WARM ADVECTION SHOULD NOT SUSTAIN THIS ACTIVITY BEYOND MID MORNING WHILE PRESSURE RISES OVER THE CNTRL PLAINS FORCE NELY LOW LEVEL FLOW INTO ERN CO. IT APPEARS THIS WILL BE THE GENERATING REGION FOR RENEWED THUNDERSTORM DEVELOPMENT BY MID AFTERNOON WHERE MODEST DEEP NWLY SHEAR VECTORS SHOULD ALLOW CONVECTION TO ORGANIZE/INTENSIFY...THEN PROPAGATE SWD TOWARD THE OK/TX PANHANDLES AND NERN NM. LARGE HAIL SHOULD BE THE MAIN SEVERE THREAT WITH SUPERCELLS AND LARGER THUNDERSTORM CLUSTERS. ...SRN MN/IA/WI/NWRN IL... HEIGHT FALLS AHEAD OF SHORTWAVE TROUGH WILL AID ASCENT AND STEEPEN LAPSE RATES ACROSS THE UPPER MS VALLEY REGION SATURDAY. EVEN SO...LOW LEVEL CONVERGENCE WILL NOT BE PARTICULARLY FOCUSED OR STRONG ALONG WIND SHIFT THAT WILL ADVANCE INTO MN/IA DURING THE AFTERNOON HOURS. ADDITIONALLY...BOUNDARY LAYER MOISTURE HAS DRIED SOMEWHAT ACROSS THIS REGION WITH SFC DEW POINTS ONLY IN THE 40S/50S. IT APPEARS THUNDERSTORMS SHOULD DEVELOP ALONG NOSE OF STRONGEST HEATING ACROSS SRN MN/NRN IA. THESE STORMS WILL MOVE SEWD WITH A THREAT OF SOME ORGANIZATION...BUT LIMITED BY INSTABILITY AND MARGINAL DEEP LAYER SHEAR. HAIL AND GUSTY WINDS MAY ACCOMPANY THIS ACTIVITY BUT THREAT APPEARS TOO LOW TO WARRANT A SLIGHT RISK AT THIS TIME. ...GULF STATES TO SRN NEW ENGLAND... THUNDERSTORMS WILL DEVELOP WITHIN VERY MOIST PLUME FROM THE CENTRAL GULF STATES INTO SRN NEW ENGLAND. LARGE SCALE FLOW WILL DIMINISH ACROSS THIS REGION AS SHORTWAVE DIGS INTO THE MID MS VALLEY...AND UPPER LOW PROPAGATES WWD INTO FL. ASIDE FROM A FEW WET MICROBURSTS IT DOES NOT APPEAR ORGANIZED SEVERE THUNDERSTORMS WILL BE AN ISSUE FOR THIS REGION SATURDAY. ..DARROW.. 06/23/2006  From swody2 at goshenarc.org Mon Jun 26 17:36:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 26 Jun 2006 13:36:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261735 SWODY2 SPC AC 261734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT MON JUN 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER PATTERN IS EXPECTED TO REMAIN GENERALLY UNCHANGED THIS PERIOD...WITH BROAD CYCLONIC FLOW OVER THE ERN 2/3 OF THE COUNTRY AND A LARGE SCALE RIDGE OVER THE WRN STATES. SEVERAL SMALLER SCALE FEATURES WILL TRAVERSE THE ERN LONGWAVE TROUGH. A VORTICITY MAXIMUM NOW OVER THE WRN ATLANTIC BASIN EAST OF NRN FL IS EXPECTED TO LIFT NWD ACROSS THE CAROLINAS AND MID-ATLANTIC REGION ON TUE. THE SECOND DISTURBANCE...NOW DROPPING SWD INTO THE MID-MS VLY REGION...WILL EJECT RAPIDLY NEWD TUE WHILE WEAKENING. A THIRD IMPULSE WILL MOVE SLOWLY SEWD ACROSS MN INTO THE UPPER MS VLY REGION THROUGH EARLY WED. AT THE SFC...LOW ASSOCIATED WITH THE ATLANTIC COASTAL UPPER FEATURE SHOULD CONTINUE TO WEAKEN WITH TIME...THOUGH BROAD SELY LOW-LEVEL FLOW N AND E OF THIS FEATURE WILL CONTINUE TO ADVECT SEASONABLY MOIST ENVIRONMENT ACROSS THE MID-ATLANTIC REGION. FURTHER W...SFC TROUGH ASSOCIATED WITH OH VALLEY VORT MAX SHOULD PERSIST ACROSS THE OH VLY REGION. FINALLY...A COLD FRONT SHOULD CONTINUE MOVING SLOWLY SWD ACROSS THE NRN/CNTRL PLAINS AND SEWD ACROSS THE UPPER MIDWEST/UPPER GRTLKS REGION THROUGH THE PERIOD. ....ERN CAROLINAS NWD TO THE MID-ATLANTIC REGION... HIGH PWAT VALUES WILL BE MAINTAINED ACROSS A LARGE PART OF THE REGION THROUGH TUE. MINIMAL CINH AND LOCALIZED FRICTIONAL CONVERGENCE WILL MAINTAIN THE RISK FOR RATHER WIDESPREAD CONVECTION. THERE WILL BE A LOW PROBABILITY FOR A TORNADO OR DAMAGING WIND GUST...PARTICULARLY ALONG THE TRACK OF THE WEAKENING DISTURBANCE THAT WILL MOVE NWD THROUGH THE CAROLINAS INTO VA DURING PEAK HEATING. PARTS OF THIS REGION MAY NEED A SLGT RISK IN LATER OUTLOOKS...ONCE MAGNITUDE OF INSTABILITY CAN BE BETTER ASSESSED. ...UPPER GRTLKS/UPPER MIDWEST WWD ACROSS NEB... BANDS OF CONVECTION WILL LIKELY INTENSIFY DURING PEAK HEATING TUE ALONG/AHEAD OF THE APPROACHING COLD FRONT...THOUGH CONVERGENCE IS EXPECTED TO REMAIN RATHER WEAK. GIVEN APPROACH OF COLD TEMPERATURES ALOFT...LAPSE RATES WILL STEEPEN ATOP AT LEAST 50S SFC DEW POINTS. AS A RESULT...A FEW STRONGER TSTMS WILL BE LIKELY WITH ISOLD HAIL. RELATIVELY DRY SUB-CLOUD LAYER AND UNIDIRECTIONAL FLOW REGIME WILL BE FAVORABLE FOR GUSTY WINDS. WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED. ...PARTS OF THE OH VLY AND MIDWEST... SLIGHTLY STRONGER/SSWLY FLOW ALOFT IS FORECAST FROM TN/KY NWD ACROSS THE MID/UPPER OH VLY REGION AND INTO SRN ONTARIO/QUEBEC AHEAD OF THE WEAKENING DISTURBANCE EJECTING NEWD. BUT...THE LATEST NAM APPEARS TO BE TOO UNSTABLE ALONG/AHEAD OF THE INVERTED TROUGH/COLD FRONT. GIVEN THAT THE DISTURBANCE WILL BE WEAKENING...SLIGHTLY WARMING MID-TROPOSPHERE AND THE FACT THAT MASS CONVERGENCE SHOULD RE-LOCATE FARTHER WEST AHEAD OF THE UPPER MS VLY IMPULSE...THE THREAT FOR SUSTAINED SEVERE CONVECTION APPEARS LIMITED. DIURNAL TSTMS ARE EXPECTED TO DEVELOP...PARTICULARLY ACROSS NRN IND INTO LWR MI AND ISOLD TSTMS MAY PRODUCE HAIL OR DAMAGING WINDS. ..RACY.. 06/26/2006  From swody2 at goshenarc.org Wed Jun 28 06:12:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 28 Jun 2006 02:12:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280610 SWODY2 SPC AC 280609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT WED JUN 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO/MID MS/TN VALLEYS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ND... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC REGION... ...SYNOPSIS... UPPER PATTERN ACROSS THE U.S. WILL CONTINUE TO FEATURE A WRN RIDGE AND ERN TROUGH...THOUGH SOME DEAMPLIFICATION OF THE FLOW FIELD SHOULD OCCUR THIS PERIOD. CORRESPONDINGLY...SURFACE PATTERN SHOULD REMAIN GENERALLY WEAK...THOUGH A COLD FRONT MOVING TOWARD THE ATLANTIC COAST...A SECOND BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS/MID MO VALLEY...AND A THIRD MOVING EWD ACROSS ND SHOULD EACH SUPPORT CONVECTIVE DEVELOPMENT AND AN ASSOCIATED/LIMITED SEVERE THREAT. ...LOWER MO/MID MS/TN VALLEYS... AFTERNOON STORMS ARE FORECAST TO DEVELOP INVOF WEAK BAROCLINIC ZONE FORECAST ACROSS THIS REGION...AS AIRMASS BECOMES MODERATELY UNSTABLE DURING THE AFTERNOON. CONVECTIVE DEVELOPMENT MAY BE AIDED BY WEAK SHORT-WAVE TROUGH FORECAST BY NUMERICAL GUIDANCE TO MOVE SEWD ACROSS THIS REGION WITHIN NWLY CYCLONIC FLOW ON THE REAR SIDE OF MAIN UPPER TROUGH. THOUGH CAP SHOULD BE STRONGER AND SHEAR WEAKER WITH WWD EXTENT INTO THE CENTRAL PLAINS...THREAT APPEARS SUFFICIENT FROM NWRN MO SEWD INTO MIDDLE TN TO WARRANT A SLIGHT RISK. ALONG WITH POTENTIAL FOR HAIL...ROUGHLY UNIDIRECTIONAL/NWLY FLOW WITH HEIGHT ALSO SUGGESTS SOME POTENTIAL FOR DAMAGING WINDS WITH SMALL-SCALE LINES/BOWS WHICH COULD DEVELOP. OVERNIGHT...LOW-LEVEL JET SHOULD SUPPORT AN INCREASE IN WARM ADVECTION -- AND SUBSEQUENT CONVECTIVE COVERAGE -- ACROSS THIS REGION...PERHAPS SUPPORTING A CONTINUED SEVERE THREAT INTO THE OVERNIGHT HOURS. ...ND... EWD-MOVING COLD FRONT -- STRETCHING FROM THE CANADIAN PRAIRIE PROVINCES SWD ACROSS ERN MT AT THE START OF THE PERIOD -- SHOULD SHIFT EWD WITH TIME THROUGH THE DAY -- AHEAD OF MID-LEVEL SHORT-WAVE TROUGH. THOUGH LARGE-SCALE RIDGE ACROSS THE PLAINS SHOULD SUPPRESS CONVECTIVE DEVELOPMENT FROM SD SWD...STORMS SHOULD DEVELOP ALONG FRONT BY LATE AFTERNOON ACROSS PARTS OF NRN AND WRN ND...WHERE 50O TO 1000 J/KG MEAN-LAYER CAPE IS ANTICIPATED. THOUGH DEEP-LAYER WIND FIELD WILL NOT BE PARTICULARLY STRONG...SLY FLOW AHEAD OF FRONT VEERING/INCREASING WITH HEIGHT TO AROUND 30 KT FROM THE NW AT MID LEVELS WILL RESULT IN SHEAR SUPPORTIVE OF MULTICELL/WEAK SUPERCELL STORMS. THUS...THREAT FOR LOCALLY STRONG/DAMAGING WINDS AND/OR HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS ACROSS THIS REGION. ...MID-ATLANTIC REGION... MODELS CONTINUE TO HINT THAT AN AREA OF SUFFICIENT DESTABILIZATION AND AMPLE SHEAR MAY COEXIST DURING THE AFTERNOON ACROSS THE MID-ATLANTIC REGION...NEAR COLD FRONT/AHEAD OF STRONG MID-LEVEL SHORT-WAVE TROUGH APPROACHING THIS REGION DURING THE AFTERNOON. PRESUMING THAT MORE WIDESPREAD PRECIPITATION WITHIN WARM CONVEYOR BELT CAN SHIFT E OF THIS REGION RESULTING IN SUFFICIENT INSTABILITY...THREAT FOR LOCALLY-SEVERE STORMS WOULD EXIST. THEREFORE...WILL RE-INTRODUCE A SLIGHT RISK ACROSS THIS REGION...GIVEN APPARENT POTENTIAL FOR HAIL AND/OR LOCALLY-DAMAGING WINDS DURING THE AFTERNOON/EARLY EVENING. ...ERN ID/SRN MT/NWRN WY... SHORT-WAVE TROUGH IS FORECAST TO ROTATE NEWD ACROSS THIS REGION DURING THE AFTERNOON...WITHIN SOMEWHAT ENHANCED FLOW ALOFT BETWEEN RIDGE OVER THE ROCKIES AND TROUGH OVER WRN CANADA. THOUGH DEGREE OF MOISTURE/INSTABILITY REMAINS QUESTIONABLE ATTM...IT APPEARS THAT SUFFICIENT COMBINATION OF SHEAR AND INSTABILITY MAY DEVELOP BY AFTERNOON TO SUPPORT SOME THREAT FOR ISOLATED SEVERE STORMS. ...UPPER GREAT LAKES... COOL /-16 TO -18/ MID-LEVEL TEMPERATURES ARE FORECAST ACROSS THIS REGION WITHIN CIRCULATION OF LARGE-SCALE TROUGH. SCATTERED LOW-TOPPED/PRIMARILY DIURNAL THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON...AS AIRMASS BECOMES MARGINALLY UNSTABLE. THOUGH GENERAL LACK OF INSTABILITY/SHEAR SHOULD PRECLUDE APPRECIABLE SEVERE THREAT...A FEW STRONGER CELLS MAY PRODUCE SMALL HAIL -- POSSIBLY APPROACHING MARGINAL SEVERE CRITERIA. ..GOSS.. 06/28/2006  From swody2 at goshenarc.org Wed Jun 28 17:24:26 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 28 Jun 2006 13:24:26 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281723 SWODY2 SPC AC 281722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1222 PM CDT WED JUN 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS THU ACROSS PARTS OF THE NRN MID ATLANTIC COAST STATES.... ...THERE IS A SLGT RISK OF SVR TSTMS THU NIGHT ACROSS PARTS OF THE MID MS VALLEY.... WESTERLIES WILL REMAIN WEAK BENEATH SUBTROPICAL RIDGE ACROSS MUCH OF THE WESTERN/SOUTHERN STATES THROUGH THIS FORECAST PERIOD. BUT ...WESTERN RIDGE MAY BEGIN TO WEAKEN SOME...AS A SUBTROPICAL IMPULSE MIGRATES AROUND ITS NORTHWESTERN/NORTHERN PERIPHERY... ACROSS THE NORTHERN INTERMOUNTAIN REGION AND NORTHERN ROCKIES. DOWNSTREAM...MODELS SUGGEST A SIGNIFICANT IMPULSE...EMBEDDED WITHIN PERSISTENT TROUGHING OVER THE GREAT LAKES/OHIO VALLEY...WILL ACCELERATE EASTWARD THROUGH MUCH OF THE NORTHEAST AND MID ATLANTIC REGION BY 12Z FRIDAY. THIS IS FORECAST TO OCCUR AS ANOTHER FAIRLY VIGOROUS SHORT WAVE TROUGH DIGS TO THE SOUTHWEST THROUGH SOUTH OF A CLOSED LOW OVER SOUTHERN HUDSON/JAMES BAY. ...EAST COAST... HIGH MOISTURE CONTENT AIR OF THE PAST SEVERAL DAYS IS EXPECTED TO SHIFT EAST OF ALL BUT THE FLORIDA PENINSULA BY EARLY THURSDAY...AS IMPULSE EMANATING FROM THE LOWER LATITUDES LIFTS NORTHEAST OF NEW ENGLAND LATER TODAY. HOWEVER...LINGERING MOISTURE IS EXPECTED TO BE SUFFICIENT FOR SCATTERED CONVECTIVE DEVELOPMENT THURSDAY... BENEATH MID-LEVEL COOL POCKET ASSOCIATED WITH APPROACHING UPPER TROUGH...FROM THE LOWER LAKES INTO THE NORTHEAST...AND AHEAD OF UPPER TROUGH AXIS ACROSS THE REMAINDER OF ATLANTIC COASTAL AREAS. BY THURSDAY AFTERNOON...MODELS SUGGEST STRONGEST FORCING FOR UPPER VERTICAL MOTION MAY BECOME JUXTAPOSED WITH STRONGEST DESTABILIZATION ACROSS PARTS OF THE NORTHERN MID ATLANTIC COAST STATES...WHERE ANY SEVERE THREAT APPEARS MOST LIKELY TO BECOME CONCENTRATED. MIXED LAYER CAPE LIKELY WILL EXCEED 1000 J/KG ACROSS THIS REGION...AND COULD APPROACH 2000 J/KG...WHICH WILL BE SUPPORTIVE OF VIGOROUS UPDRAFTS. THOUGH LOW-LEVEL FLOW WILL BECOME RATHER WEAK...30 TO 40+ KT SOUTHERLY MID-LEVEL FLOW AHEAD OF UPPER TROUGH AXIS WILL CONTRIBUTE TO A MODERATELY SHEARED REGIME WHICH COULD ENHANCE HAIL POTENTIAL IN STRONGEST STORMS. ...CENTRAL STATES... WEAK SURFACE FRONT/LOW-LEVEL BAROCLINIC ZONE IS EXPECTED TO STALL FROM PARTS OF THE TENNESSEE VALLEY THROUGH THE LOWER MISSOURI VALLEY...AND COULD BECOME FOCUS FOR WIDELY SCATTERED THUNDERSTORMS LATE THURSDAY AFTERNOON. LOW-LEVEL THERMAL RIDGE AXIS TO THE SOUTH OF BOUNDARY WILL CONTRIBUTE TO STEEP LAPSE RATES AND FAVORABLE THERMODYNAMIC ENVIRONMENT FOR HAIL/GUSTY WINDS IN STRONGER STORMS. HOWEVER...POTENTIAL FOR A MORE ORGANIZED OR CONCENTRATED SEVERE THREAT SEEMS LOW UNTIL AFTER DARK...WHEN NOCTURNAL STRENGTHENING OF LOW-LEVEL JET..TO THE NORTH OF LOWER MISSISSIPPI VALLEY LOW-LEVEL RIDGE...COULD SUPPORT A GROWING CLUSTER OF STORMS. MODELS SUGGEST THIS IS MOST PROBABLE TO THE COOL SIDE OF THE SURFACE FRONT...ACROSS PARTS OF SOUTHERN IOWA/ NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS BY LATE THURSDAY NIGHT. ...WESTERN STATES... STRONGEST FORCING ASSOCIATED WITH SUBTROPICAL IMPULSE APPEARS LIKELY TO SHIFT ACROSS IDAHO THROUGH THE NORTHERN ROCKIES DURING THE DAYTIME HOURS THURSDAY. UNCERTAINTY EXISTS CONCERNING EXTENT OF CLOUD COVER LINGERING FROM DAY 1 CONVECTION...AND ITS INFLUENCE ON MAGNITUDE OF DAYTIME HEATING. BUT...EVEN IF CAPE IS MINIMAL... LARGE LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL BE FAVORABLE FOR AT LEAST LOCALIZED DOWNBURSTS. ..KERR.. 06/28/2006  From swody2 at goshenarc.org Tue Jun 6 06:12:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 06 Jun 2006 02:12:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060609 SWODY2 SPC AC 060608 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0108 AM CDT TUE JUN 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY TO MIDDLE TN... ...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE PART OF THE INTERIOR NORTHWEST/NRN ROCKIES/NRN HIGH PLAINS... ...SYNOPSIS... EXPANSIVE WCNTRL U.S. UPPER RIDGE IS FORECAST TO BEGIN TO BREAK DOWN ACROSS THE NRN ROCKIES AND NRN PLAINS THROUGH WEDNESDAY AS NUMEROUS SHORT WAVE IMPULSES RIDE AROUND THE WRN/NRN PERIPHERY OF THE ANTICYCLONE AND COMBINE WITH STRONGER HEIGHT FALLS ACCOMPANYING A PACIFIC SHORT WAVE TROUGH MOVING INLAND OVER WA/ORE THROUGH EARLY THURSDAY. A DEAMPLIFYING SHORT WAVE IMPULSE... CURRENTLY CROSSING THE UPPER MS VALLEY ON THE ERN FLANK OF THE LARGE UPPER HIGH...IS FORECAST TO SPREAD SEWD FROM THE GREAT LAKES TO THE OH VALLEY THROUGH WEDNESDAY EVENING. THIS SYSTEM WILL ACT TO REESTABLISH THE MEAN TROUGH SITUATED ACROSS THE ERN SEABOARD AS EXISTING/PERSISTENT DEEP LAYER LOW OVER THIS REGION IS EJECTED NEWD OFF THE NEW ENGLAND COAST THROUGH EARLY THURSDAY. ...MIDWEST TO LOWER MS VALLEY/NRN GULF COAST... INCREASINGLY DIFFLUENT MID LEVEL FLOW WILL DEVELOP ACROSS THE MIDWEST AND LOWER MS VALLEY THROUGH WEDNESDAY AFTERNOON AS WEAK HEIGHT FALLS ASSOCIATED WITH GREAT LAKES/MIDWEST SHORT WAVE TROUGH SPREAD SEWD ON THE ERN FLANK OF THE LARGE UPPER RIDGE. LOW LEVEL MOISTURE FOCUSED ALONG WEAK WIND SHIFT WILL COMBINE WITH SURFACE HEATING TO PRODUCE A NARROW AXIS OF STRONGER INSTABILITY FROM LA/AR NEWD TO IND/OH. STRONGER LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH THE SHORT WAVE TROUGH IS FORECAST TO EXIST ACROSS THE OH VALLEY AREA...COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION. ADDITIONALLY...STRONGER MID LEVEL NWLY FLOW WILL CONTRIBUTE TO MORE THAN ADEQUATE SHEAR ACROSS THIS REGION FOR ORGANIZED STORMS. ACTIVITY MAY BUILD/INCREASE SWWD INTO INSTABILITY AXIS FROM SRN IND ACROSS KY AND MIDDLE TN AS MID LEVEL WIND MAX PASSES OVERHEAD. A FEW CLUSTERS OF ORGANIZED STORMS...PERHAPS A COUPLE OF SUPERCELLS...WITH HAIL AND WIND DAMAGE POTENTIAL APPEAR POSSIBLE. ACTIVITY FARTHER SWWD INTO THE LOWER MS VALLEY/NRN GULF COAST IS FORECAST TO REMAIN MORE ISOLATED GIVEN WEAKER LARGE SCALE SUPPORT. ...INTERIOR NORTHWEST ACROSS THE ROCKIES TO NRN PLAINS... WIDESPREAD CONVECTION IS FORECAST ACROSS PARTS OF THE GREAT BASIN AS DIURNAL HEATING COMBINES WITH A NUMBER OF SMALL SCALE PERTURBATIONS RIDING UP AND AROUND THE WRN/NRN FLANK OF THE UPPER RIDGE. ADDITIONAL ACTIVITY IS EXPECTED TO INCREASE EAST OF THE CONTINENTAL DIVIDE FROM NM ACROSS CO/WY/MT OWING TO RELATIVELY MOIST UPSLOPE FLOW IN VICINITY OF RESIDUAL FRONTAL BOUNDARY BACKED INTO THE HIGHER TERRAIN. MODELS APPEAR IN REASONABLE AGREEMENT THAT STRONGEST LARGE SCALE FORCING WILL DEVELOP EAST ACROSS THE CASCADES AS A PACIFIC SHORT WAVE TROUGH MOVES INLAND AND PROMOTES ANOTHER AREA OF STRONG TO SEVERE CONVECTIVE POTENTIAL FROM THE UPPER COLUMBIA RIVER VALLEY...EAST ACROSS WRN MT. OVERALL FORCING AND DEEP LAYER SHEAR WILL FAVOR SEVERE STORMS WITH HAIL AND WIND OVER ALL OF THESE AREAS WITH MORE PERSISTENT ACTIVITY PERHAPS CONSOLIDATING NEAR THE SHORT WAVE TROUGH FROM ORE/WA EWD ACROSS MT DURING THE AFTERNOON AND EVENING. OTHER STORMS/SUPERCELLS DEVELOPING ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS FROM NRN WY AND SERN MT TO THE SD BLACK HILLS ARE EXPECTED TO CONGEAL INTO AN MCS OR TWO THROUGH THE EVENING. IN ADDITION TO ISOLATED TORNADO THREAT WITH INITIAL DISCRETE CONVECTION...LARGE HAIL AND WIND POTENTIAL MAY PERSIST AS ACTIVITY DEVELOPS INTO STRENGTHENING WARM AIR ADVECTION REGIME FROM ERN MT INTO THE WRN DAKOTAS OVERNIGHT. ...SOUTHWEST... ANTICIPATED PLUME OF GREATER MID LEVEL MOISTURE STREAMING NWD ON THE WRN FLANK OF THE UPPER RIDGE...COUPLED WITH STRONG HEATING AND UPSLOPE FLOW ACROSS THE SOUTHWEST...WILL LIKELY SPUR SCATTERED TO NUMEROUS TSTMS. MODELS SUGGEST THAT SLIGHTLY STRONGER MID LEVEL FLOW ACROSS SRN AZ WILL CONTRIBUTE TO POCKETS OF GREATER DEEP LAYER SHEAR SUPPORTIVE OF UPDRAFT PERSISTENCE. ISOLATED TO WIDELY SCATTERED DAMAGING DOWNBURSTS...AND A FEW HAIL EVENTS...APPEAR POSSIBLE WITH THIS ACTIVITY THROUGH EVENING. ..CARBIN.. 06/06/2006  From swody2 at goshenarc.org Tue Jun 6 17:38:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 06 Jun 2006 13:38:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061736 SWODY2 SPC AC 061734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT TUE JUN 06 2006 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY IN THE LOWER MS VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN INTERMOUNTAIN REGION EWD INTO THE NRN PLAINS... ...SYNOPSIS... MODELS INDICATE HIGH AMPLITUDE UPPER FLOW PATTERN WILL CONTINUE TOMORROW. IN THE EAST...A MEAN TROUGH WILL BE MAINTAINED AS A WELL-DEFINED VORTICITY CENTER CURRENTLY APPROACHING WRN LAKE SUPERIOR MOVES SEWD ACROSS THE GREAT LAKES TOWARD THE OH VALLEY...WHILE DOWNSTREAM UPPER LOW ALONG THE CAROLINA COAST LIFTS NWD TOWARD NEW ENGLAND. FARTHER WEST...MODELS SUGGEST SLOW PROGRESSION OF LARGE SCALE FEATURES AS THE WRN RIDGE AXIS SLOWLY SHIFTS EWD TOWARD THE HIGH PLAINS IN ADVANCE OF A SHORT WAVE TROUGH MOVING TOWARD THE PACIFIC NORTHWEST COAST. AT THE SURFACE...A WEAK LOW ASSOCIATED WITH THE GREAT LAKES UPPER SYSTEM WILL MOVE SEWD FROM MI INTO OH...WHILE WEAKENING FRONT MOVES SLOWLY SEWD REACHING A WRN OH/WRN TN/CENTRAL TX LINE DURING THE LATE AFTERNOON/EVENING. A SECOND FRONT WILL EXTEND FROM ONTARIO AND LAKE SUPERIOR WWD ACROSS SD INTO A LOW OVER NRN ID AREA...AND A PACIFIC COLD FRONT WILL MOVE INLAND ACROSS PARTS OF WA/ORE/ID/WRN MT DURING THE PERIOD. ...OH VALLEY INTO THE LOWER MS VALLEY... SEVERAL BANDS OF THUNDERSTORMS MAY BE ONGOING AT THE START OF THE PERIOD FROM LAKE MI/LOWER MI SWD INTO THE LOWER MS VALLEY. SCATTERED CONVECTION NEAR THE FRONT IS EXPECTED TO CONTINUE MOVING SLOWLY EWD/SEWD DURING THE DAY...WHICH WILL INHIBIT STRONG INSOLATION AND DESTABILIZATION DOWNSTREAM FROM ACTIVE AREAS OF STORMS. HOWEVER...THUNDERSTORMS MAY REDEVELOP OVER THE NRN PARTS OF THE RISK AREA IN THE WAKE OF THE MORNING THUNDERSTORMS AS DYNAMIC FORCING ASSOCIATED WITH THE UPPER VORTICITY OVERSPREADS THE FRONT AND REGION OF ENHANCED MOISTURE/INSTABILITY. THESE STORMS WILL ALSO BE LOCATED IN CLOSER PROXIMITY TO THE STRONGER NLY MID LEVEL WINDS/DEEP LAYER SHEAR...WHICH WILL ENHANCE CONVECTIVE ORGANIZATION AND INDICATE A THREAT FOR A FEW SEVERE STORMS TO DEVELOP. FARTHER SOUTH...INCREASINGLY DIFFLUENT FLOW ALOFT FAVORS DEVELOPMENT OF A FEW SEVERE THUNDERSTORMS OVER PARTS OF THE LOWER MS VALLEY. DAMAGING WIND GUSTS AND HAIL WILL BE THE PRIMARY THREATS ACROSS THESE REGIONS MAINLY DURING THE AFTERNOON AND EVENING HOURS. ...NRN INTERMOUNTAIN REGION... UPPER SHORT WAVE TROUGH NOW NEARING 137W IS FORECAST TO MOVE INLAND INTO THE PACIFIC NORTHWEST TOMORROW. SCATTERED THUNDERSTORMS DURING DAY 1 PERIOD MAY RESULT IN INCREASED MOISTURE AVAILABILITY ON WEDNESDAY IN ADVANCE OF THE APPROACHING COLD FRONT. PRE-EXISTING STEEP MID LEVEL LAPSE RATES WILL AID DEVELOPMENT OF UNSTABLE ENVIRONMENT WITH MLCAPE OF 1000-1500 J/KG. DYNAMIC FORCING ASSOCIATED WITH RIGHT ENTRANCE REGION OF UPPER LEVEL JET STREAK COUPLED WITH FRONTAL CONVERGENCE AND TERRAIN EFFECTS WILL RESULT IN SCATTERED THUNDERSTORMS DEVELOPING OVER PARTS OF ERN ORE/EXTREME SERN WA INTO NRN/CENTRAL ID AND WRN MT DURING THE LATE AFTERNOON THROUGH THE EVENING HOURS. DEEP LAYER SHEAR OF 30-40 KT IN THE LOWEST 6 KM WILL BE SUPPORTIVE OF A FEW SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL..DAMAGING WIND GUSTS..AND AN ISOLATED TORNADO OR TWO. ...NRN ROCKIES INTO NRN PLAINS... A LOW LEVEL MOIST AXIS IS FORECAST TO DEVELOP TOMORROW OVER PARTS OF SD/NRN WY AND MT AS ELY LOW LEVEL WINDS STRENGTHEN NORTH OF THE AFOREMENTIONED EAST/WEST NRN PLAINS FRONT. VERY STEEP LAPSE RATES WILL ENHANCE INSTABILITY...AND LOW LEVEL UPSLOPE WINDS WILL COMBINE WITH WEAK PERTURBATIONS ALONG THE NRN EDGE OF THE UPPER RIDGE TO AID IN DEVELOPMENT OF SCATTERED THUNDERSTORMS DURING THE LATE AFTERNOON AND EVENING. STRONG DIRECTIONAL SHEAR WITH HEIGHT WILL SUPPORT A FEW SEVERE STORMS. CONVECTIVE THREAT WILL CONTINUE OVER THE HIGH PLAINS DURING THE NIGHT AS THE SOUTHERLY LOW LEVEL JET INTENSIFIES OVER NEB/SD...ENHANCING LOW LEVEL WARM ADVECTION/CONVERGENCE ALONG/NORTH OF THE FRONT. ...SERN CA/AZ... MID LEVEL MOISTURE IS EXPECTED TO PERSIST ON THE WRN PERIPHERY OF THE UPPER RIDGE...WHERE STEEP LAPSE RATES AND DEEP WELL-MIXED LAYER WILL BE PRESENT. HIGH-BASED THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING AND SPREAD NWD/NWWD WITHIN BAND OF 25-30 KT SSELY MID LEVEL WINDS. THERE IS POTENTIAL FOR ISOLATED DAMAGING DOWNBURSTS AND POSSIBLY HAIL TO OCCUR WITH STRONGEST CELLS. ..WEISS.. 06/06/2006  From swody2 at goshenarc.org Wed Jun 7 06:15:56 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 07 Jun 2006 02:15:56 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070611 SWODY2 SPC AC 070610 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0110 AM CDT WED JUN 07 2006 VALID 081200Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN ROCKIES TO NRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SOUTHEAST COAST... ...SYNOPSIS... HIGH AMPLITUDE FLOW WILL REMAIN WELL ESTABLISHED OVER THE U.S. DURING THURSDAY AND FRIDAY AND CONSIST OF A BROAD DEEP LAYERED ANTICYCLONE SETTLING ACROSS THE SCNTRL CONUS...A RELATIVELY STRONG TROUGH ALONG THE EAST COAST...AND ANOTHER TROUGH DEVELOPING GRADUALLY INLAND FROM THE PACIFIC NORTHWEST. ONE OR MORE SUBTLE SHORT WAVE DISTURBANCES...ROUNDING THE WRN AND NRN PERIPHERY OF THE UPPER RIDGE...WILL LIKELY AID IN THE DEVELOPMENT AND ORGANIZATION OF DEEP CONVECTION FROM THE GREAT BASIN TO THE NRN PLAINS DURING THE DAY ONE PERIOD. THESE FEATURES...COUPLED WITH HEIGHT FALLS ASSOCIATED WITH THE HIGHER AMPLITUDE TROUGH MOVING ACROSS THE NORTHWEST...WILL SUBSTANTIALLY ERODE THE NWRN FLANK OF THE RIDGE CURRENTLY SITUATED ACROSS THE NRN ROCKIES. A BROAD BELT OF MODEST SWLY TO WLY DIFFLUENT FLOW ALOFT WILL EXTEND FROM THE NRN GREAT BASIN TO THE NRN PLAINS BY EARLY FRIDAY...AS CENTER OF UPPER HIGH CONSOLIDATES ACROSS THE SRN PLAINS. SHORT WAVE TROUGH AND ASSOCIATED WIND MAX CURRENTLY MOVING ACROSS THE GREAT LAKES REGION WILL CONTINUE SEWD WITH STRENGTHENING DIFFLUENT MID LEVEL FLOW SPREADING ACROSS THE NRN GULF AND SOUTHEAST COASTS THROUGH THURSDAY AFTERNOON. ...NRN ROCKIES TO NRN HIGH PLAINS... APPROACH OF PACIFIC TROUGH AND UPSTREAM AMPLIFICATION OF UPPER RIDGE ACROSS THE CANADIAN PRAIRIES WILL ENHANCE LOW LEVEL SELY/UPSLOPE FLOW ACROSS MT/WY ON THE SWRN PERIPHERY OF SURFACE HIGH CENTERED OVER SCNTRL CANADA. COUPLED WITH EXTENSIVE ZONE OF DIFFLUENT MID LEVEL FLOW FROM THE ROCKIES TO THE NRN/CNTRL HIGH PLAINS...A NW-SE ORIENTED BAND OF STRONG WARM AIR ADVECTION AND ELEVATED CONVECTION IS EXPECTED TO BE ONGOING BY EARLY THURSDAY FROM NERN MT...ACROSS THE DAKOTAS...TO IA. A WARM AND RELATIVELY MOIST AIR MASS IS EXPECTED TO DEVELOP IN THE WAKE OF THIS ACTIVITY...AND AHEAD OF STRENGTHENING LEE TROUGH AND SLOW MOVING COLD FRONT...FROM ID EWD ACROSS WRN/CNTRL MT...AND NRN/ERN WY. CONVECTION DURING THE DAY ONE PERIOD WILL FURTHER ENHANCE BOUNDARY LAYER MOISTURE ACROSS THESE AREAS WITH STEEPENING LAPSE RATES AND SURFACE HEATING CONTRIBUTING TO AREAS OF STRONG DESTABILIZATION BY AFTERNOON. STORMS WILL INITIATE ON THE HIGHER TERRAIN AND INCREASE IN COVERAGE AND INTENSITY AS GREATER INSTABILITY AND SHEAR IS REALIZED. SEVERAL CLUSTERS/LINES OF STORMS/SUPERCELLS WILL MOVE EWD/NEWD INTO THE EVENING WITH THE CHANCE FOR LARGE HAIL/HIGH WINDS AND PERHAPS A TORNADO OR TWO. ONE OR TWO SMALL CLUSTERS OF STORMS MAY PERSIST AND MOVE EAST INTO HOT AND DEEPLY MIXED BOUNDARY LAYER FROM ERN WY ACROSS WRN NEB AND SD DURING THE EVENING. LEE-LOW MAY FURTHER SUPPORT THE UPSCALE EVOLUTION INTO AN MCS WITH WIND/HAIL POTENTIAL SPREADING EAST DURING THE NIGHT. A SEPARATE AREA OF STRONG FORCING ON THE NOSE OF THE LOW LEVEL JET MAY PROMOTE STORM INITIATION ON THE EDGE OF THE CAP...FROM ERN DAKOTAS INTO MN/IA THROUGH EARLY FRIDAY. GIVEN POTENTIAL FOR VERY STEEP MID LEVEL LAPSE RATES AND STRENGTHENING SHEAR ACROSS THESE AREAS...A FEW HAIL EVENTS WILL BE POSSIBLE WITH THIS ACTIVITY. ...OH VALLEY TO SOUTHEAST/NRN GULF COAST... STRONGER FORCING AND SHEAR ACCOMPANYING SHORT WAVE DISTURBANCE WILL DEVELOP SEWD FROM THE OH VALLEY TO THE SRN APPALACHIANS AND ARRIVE OVER THE SOUTHEAST COINCIDENT WITH DAYTIME HEATING/DESTABILIZATION. ALTHOUGH LOW LEVEL MOISTURE IS NOT EXPECTED TO BE GREAT IN THE WAKE OF RECENT COOL OFFSHORE FLOW ASSOCIATED WITH PERSISTENT UPPER LOW...STEEPENING LAPSE RATES AND GREATER MOISTURE/INSTABILITY...ESPECIALLY NEARER THE COAST...COULD PROMOTE STRONG TO SEVERE STORMS. SOMEWHAT WEAKER LOW LEVEL FORCING/CONVERGENCE ON THE FRONT/WIND SHIFT...BUT POTENTIALLY STRONGER SHEAR AND ADEQUATE INSTABILITY...COULD LEAD TO A FEW ORGANIZED STORMS WITH HAIL AND WIND FROM GA WWD/SWWD ALONG THE NRN GULF COAST. ...SOUTHWEST ACROSS THE FOUR CORNERS... DEEP HEATING/MIXING AND MID LEVEL MOISTENING ON THE WRN FLANK OF UPPER RIDGE WILL AGAIN RESULT IN WIDESPREAD AFTERNOON TSTMS FROM THE SOUTHWEST ACROSS THE FOUR CORNERS TO THE FRONT RANGE AND HIGH PLAINS. GIVEN POCKETS OF LOCALLY STRONGER DEEP LAYER SHEAR...AND DRY SUBCLOUD/INVERTED-V PROFILES...A FEW STORMS COULD PRODUCE HAIL AND DOWNBURST WINDS. ..CARBIN.. 06/07/2006  From swody2 at goshenarc.org Fri Jun 9 06:02:02 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 02:02:02 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090559 SWODY2 SPC AC 090558 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN MT TO THE TN VALLEY... ...SYNOPSIS... UPPER RIDGE WILL FLATTEN CONSIDERABLY DURING THE DAY2 PERIOD AS HEIGHTS FALL ACROSS THE NRN ROCKIES FORCING SEVERAL SHORTWAVE TROUGHS ACROSS THE NRN/CNTRL PLAINS INTO THE MS VALLEY REGION. THIS EVOLUTION WILL BECOME VERY FAVORABLE FOR MULTIPLE MCS-TYPE EPISODES FROM THE NRN HIGH PLAINS...SEWD INTO THE TN VALLEY. ...TN VALLEY... ONE SUCH MCS CLUSTER WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD FROM IA INTO IL. WNWLY STEERING CURRENTS WILL ALLOW THIS ACTIVITY TO SPREAD DOWNSTREAM ALONG EXISTING FRONTAL BOUNDARY INTO KY/TN WITH DAYTIME INTENSIFICATION POSSIBLE WITHIN 30-40KT DEEP LAYER SHEAR. UPSTREAM...SFC FRONT WILL SAG SWD IN WAKE OF EARLY MORNING MCS ACROSS KS...WHILE INTENSE HEATING ACROSS THE SRN HIGH PLAINS WILL ALLOW DRY LINE TO MIX EWD TO A POSITION FROM THE TX SOUTH PLAINS INTO SCNTRL KS. THIS BOUNDARY MAY PROVE SUFFICIENT IN GENERATING ISOLATED SEVERE...MAINLY DIURNAL...THUNDERSTORMS WHERE TEMPERATURE DEW POINT SPREADS WILL BE MAXIMIZED...APPROACHING 50F...ENHANCING DOWNBURST POTENTIAL. ...NRN ROCKIES/HIGH PLAINS... ANOTHER MORE SYNOPTICALLY EVIDENT REGION FOR ASCENT WILL OCCUR ACROSS THE NRN ROCKIES INTO THE HIGH PLAINS OF ERN WY. SFC RIDGING ACROSS THE NRN/CNTRL PLAINS WILL FORCE MODIFIED BOUNDARY LAYER MOISTURE WELL WEST AGAINST THE HIGHER TERRAIN OF WY INTO SRN MT. IT APPEARS THUNDERSTORMS WILL EASILY DEVELOP BY MID AFTERNOON ACROSS THIS REGION WITHIN EXIT REGION OF JET BENEATH COLD THERMAL TROUGH. VERTICAL SHEAR PROFILES WILL SUPPORT STORM ROTATION WITH STRONG VEERING WITH HEIGHT AND SUFFICIENT SPEED SHEAR FOR SUPERCELL DEVELOPMENT. A VERY ACTIVE CONVECTIVE AFTERNOON/EVENING IS POSSIBLE FROM SCNTRL MT INTO SERN WY BEFORE ACTIVITY MERGES INTO AN MCS OVER THE NEB PANHANDLE...SPREADING SEWD TOWARD THE CNTRL PLAINS DURING THE OVERNIGHT HOURS. IF SUFFICIENT LOW LEVEL MOISTURE CAN RETURN TO WY/NEB PANHANDLE IT APPEARS TO BE A FAVORABLE SETUP FOR POSSIBLE TORNADOES PRIOR TO MCS EVOLUTION. ..DARROW.. 06/09/2006  From swody2 at goshenarc.org Fri Jun 9 17:33:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 13:33:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091731 SWODY2 SPC AC 091729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN/CENTRAL ROCKIES EWD ACROSS THE CENTRAL PLAINS INTO PORTIONS OF THE MID MS/TN/LOWER OH VALLEYS... ...SYNOPSIS.. LARGE UPPER RIDGE...CURRENTLY LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY...WILL FLATTEN BY SATURDAY AS A SERIES OF SHORTWAVE TROUGHS EJECT NEWD FROM THE SWRN U.S. INTO THE PLAINS STATES. THIS WILL RESULT IN 30-50 KT WLY MID LEVEL FLOW TO EXTEND W TO E ACROSS THE CENTRAL CONUS. UNDER THIS STRONGER MID LEVEL FLOW...A QUASI-STATIONARY COLD FRONT IS FORECAST TO EXTEND FROM ERN WY/CO EWD ACROSS KS/MID MS VALLEY/LOWER OH VALLEY INTO NC BY LATE IN THE DAY. THIS PATTERN SHOULD SUPPORT SEVERAL MCS EPISODES TO SPREAD EWD...MAINLY ALONG AND NORTH OF THE FRONT...FROM THE ROCKIES/CENTRAL PLAINS ESEWD INTO THE LOWER OH VALLEY/TN VALLEY REGION. ...MID MS/LOWER OH/TN VALLEYS... A WEAKENING MCS IS LIKELY BE ONGOING AT THE START OF THE PERIOD IN IL. WEAK WARM ADVECTION IS EXPECTED TO MAINTAIN THIS CONVECTION AS WNWLY FLOW ALOFT PUSHES THIS SYSTEM INTO THE LOWER OH VALLEY/ERN TN VALLEY REGION DURING THE AFTERNOON. WITH HEATING...MLCAPES BETWEEN 1000-1500 J/KG AND 30-40 KT DEEP LAYER SHEAR MAY AID STORM INTENSIFICATION. WIND DAMAGE IS EXPECTED TO THE MAIN THREAT GIVEN THE 30-50 KT WNWLY WINDS THAT WILL BE LOCATED ABOVE THE BOUNDARY LAYER. STORMS ARE EXPECTED TO WEAKEN AS THEY CROSS THE APPALACHIANS AND ENCOUNTER A MORE STABLE ENVIRONMENT. ETA/GFS ARE BOTH SUGGESTIVE OF SHORTWAVE TROUGH MOVING INTO KS/OK LATE IN THE DAY. THIS WILL INCREASE THE LOW LEVEL JET/WARM ADVECTION NORTH OF THE FRONT ACROSS PORTIONS OF ERN KS/WRN MO. THE LIFT ASSOCIATED WITH THESE FEATURES SHOULD AID STORM INITIATION ACROSS PORTIONS OF KS/MO LATE IN THE DAY. ALTHOUGH FORECAST OF MID AND UPPER 60 DEWPOINTS WILL LIKELY BE CONFINED CLOSE TO THE SURFACE...STEEP MID LEVEL LAPSE RATES WILL LIKELY RESULT IN AT LEAST MODERATE INSTABILITY. STRENGTHENING...MOSTLY UNIDIRECTIONAL...WLY WINDS ABOVE THE BOUNDARY LAYER SHOULD RESULT IN 30-40 KT OF DEEP LAYER SHEAR. THE LARGE SCALE LIFTING COMBINED WITH THE SHEAR AND DEGREE OF INSTABILITY SHOULD RESULT IN SEVERE STORMS DEVELOPING IN ERN KS/WRN MO LATE IN THE DAY. THE UNIDIRECTIONAL FLOW ALOFT SHOULD HELP TO CONSOLIDATE UPDRAFTS INTO AND MCS WITH THE SYSTEM MOVING ESEWD OVERNIGHT INTO THE LOWER OH VALLEY. ...NRN ROCKIES/HIGH PLAINS... MODELS SUGGEST SHORTWAVE TROUGH AND 50 KT JET MAX WILL MOVE EWD INTO THE REGION...WHERE ELY UPSLOPE FLOW WILL BE MOISTENING BOUNDARY LAYER. THE COMBINATION OF LARGE SCALE LIFTING AND UPSLOPE FLOW SHOULD RESULT IN NUMEROUS THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN FROM MT SWD INTO NRN CO. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS DUE TO STRONG VEERING WIND PROFILES AND 40-50 KT MID LEVEL WINDS. ALTHOUGH THE SHEAR AND INSTABILITY MAY SUPPORT A COUPLE OF TORNADOES...THE ACTIVITY IS EXPECTED TO MERGE INTO A FEW COMPLEXES AND THEN MOVE SEWD INTO THE PLAINS WITH HAIL/WIND THE MAIN THREATS. ..SRN PLAINS.... MID/HIGH LEVEL TROPICAL MOISTURE FROM THE ITCZ IS EXPECTED TO STREAM NEWD FROM MEXICO ACROSS TX INTO WRN OK/SRN KS. INTENSE HEATING SHOULD HELP TO CREATE DRY ADIABATIC LAPSE RATES FROM THE SURFACE TO THE LFC...AROUND 10 KFT...WHICH SHOULD AID IN HIGH BASE CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THE DEEP WELL MIXED BOUNDARY LAYER MAY BE SUFFICIENT IN GENERATING ISOLATED SEVERE WIND GUSTS BETWEEN 21-03Z. ..IMY.. 06/09/2006  From swody2 at goshenarc.org Fri Jun 9 17:41:08 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 09 Jun 2006 13:41:08 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 091739 SWODY2 SPC AC 091738 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 PM CDT FRI JUN 09 2006 VALID 101200Z - 111200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN/CENTRAL ROCKIES EWD ACROSS THE CENTRAL PLAINS INTO PORTIONS OF THE MID MS/TN/LOWER OH VALLEYS... ...SYNOPSIS.. LARGE UPPER RIDGE...CURRENTLY LOCATED OVER THE CENTRAL PORTIONS OF THE COUNTRY...WILL FLATTEN BY SATURDAY AS A SERIES OF SHORTWAVE TROUGHS EJECT NEWD FROM THE SWRN U.S. INTO THE PLAINS STATES. THIS WILL RESULT IN 30-50 KT WLY MID LEVEL FLOW TO EXTEND W TO E ACROSS THE CENTRAL CONUS. UNDER THIS STRONGER MID LEVEL FLOW...A QUASI-STATIONARY COLD FRONT IS FORECAST TO EXTEND FROM ERN WY/CO EWD ACROSS KS/MID MS VALLEY/LOWER OH VALLEY INTO NC BY LATE IN THE DAY. THIS PATTERN SHOULD SUPPORT SEVERAL MCS EPISODES TO SPREAD EWD...MAINLY ALONG AND NORTH OF THE FRONT...FROM THE ROCKIES/CENTRAL PLAINS ESEWD INTO THE LOWER OH VALLEY/TN VALLEY REGION. ...MID MS/LOWER OH/TN VALLEYS... A WEAKENING MCS IS LIKELY BE ONGOING AT THE START OF THE PERIOD IN IL. WEAK WARM ADVECTION IS EXPECTED TO MAINTAIN THIS CONVECTION AS WNWLY FLOW ALOFT PUSHES THIS SYSTEM INTO THE LOWER OH VALLEY/ERN TN VALLEY REGION DURING THE AFTERNOON. WITH HEATING...MLCAPES BETWEEN 1000-1500 J/KG AND 30-40 KT DEEP LAYER SHEAR MAY AID STORM INTENSIFICATION. WIND DAMAGE IS EXPECTED TO THE MAIN THREAT GIVEN THE 30-50 KT WNWLY WINDS THAT WILL BE LOCATED ABOVE THE BOUNDARY LAYER. STORMS ARE EXPECTED TO WEAKEN AS THEY CROSS THE APPALACHIANS AND ENCOUNTER A MORE STABLE ENVIRONMENT. ETA/GFS ARE BOTH SUGGESTIVE OF SHORTWAVE TROUGH MOVING INTO KS/OK LATE IN THE DAY. THIS WILL INCREASE THE LOW LEVEL JET/WARM ADVECTION NORTH OF THE FRONT ACROSS PORTIONS OF ERN KS/WRN MO. THE LIFT ASSOCIATED WITH THESE FEATURES SHOULD AID STORM INITIATION ACROSS PORTIONS OF KS/MO LATE IN THE DAY. ALTHOUGH FORECAST OF MID AND UPPER 60 DEWPOINTS WILL LIKELY BE CONFINED CLOSE TO THE SURFACE...STEEP MID LEVEL LAPSE RATES WILL LIKELY RESULT IN AT LEAST MODERATE INSTABILITY. STRENGTHENING...MOSTLY UNIDIRECTIONAL...WLY WINDS ABOVE THE BOUNDARY LAYER SHOULD RESULT IN 30-40 KT OF DEEP LAYER SHEAR. THE LARGE SCALE LIFTING COMBINED WITH THE SHEAR AND DEGREE OF INSTABILITY SHOULD RESULT IN SEVERE STORMS DEVELOPING IN ERN KS/WRN MO LATE IN THE DAY. THE UNIDIRECTIONAL FLOW ALOFT SHOULD HELP TO CONSOLIDATE UPDRAFTS INTO AND MCS WITH THE SYSTEM MOVING ESEWD OVERNIGHT INTO THE LOWER OH VALLEY. ...NRN ROCKIES/HIGH PLAINS... MODELS SUGGEST SHORTWAVE TROUGH AND 50 KT JET MAX WILL MOVE EWD INTO THE REGION...WHERE ELY UPSLOPE FLOW WILL BE MOISTENING BOUNDARY LAYER. THE COMBINATION OF LARGE SCALE LIFTING AND UPSLOPE FLOW SHOULD RESULT IN NUMEROUS THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN FROM MT SWD INTO NRN CO. VERTICAL SHEAR PROFILES WILL SUPPORT SUPERCELLS DUE TO STRONG VEERING WIND PROFILES AND 40-50 KT MID LEVEL WINDS. ALTHOUGH THE SHEAR AND INSTABILITY MAY SUPPORT A COUPLE OF TORNADOES...THE ACTIVITY IS EXPECTED TO MERGE INTO A FEW COMPLEXES AND THEN MOVE SEWD INTO THE PLAINS WITH HAIL/WIND THE MAIN THREATS. ..SRN PLAINS.... MID/HIGH LEVEL TROPICAL MOISTURE FROM THE ITCZ IS EXPECTED TO STREAM NEWD FROM MEXICO ACROSS TX INTO WRN OK/SRN KS. INTENSE HEATING SHOULD HELP TO CREATE DRY ADIABATIC LAPSE RATES FROM THE SURFACE TO THE LFC...AROUND 10 KFT...WHICH SHOULD AID IN HIGH BASE CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THE DEEP WELL MIXED BOUNDARY LAYER MAY BE SUFFICIENT IN GENERATING ISOLATED SEVERE WIND GUSTS BETWEEN 21-03Z. ..IMY.. 06/09/2006  From swody2 at goshenarc.org Sat Jun 10 05:46:30 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 10 Jun 2006 01:46:30 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 100544 SWODY2 SPC AC 100543 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT SAT JUN 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MO TO THE CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN CO TO SERN MT... ...MO TO CAROLINAS... LARGE SCALE HEIGHT RISES ACROSS THE PLAINS DURING THE DAY2 PERIOD WILL LIMIT STRONG THUNDERSTORM DEVELOPMENT TO THAT REGION FORCED BY LOW LEVEL WARM ADVECTION ACROSS THE MID MS/TN VALLEY...CAROLINAS...AND UPSLOPE REGIONS OF THE HIGH PLAINS. IT APPEARS AN MCS WILL BE ONGOING EARLY IN THE PERIOD OVER MO AIDED BY FOCUSED LLJ THAT SHOULD VEER AND WEAKEN SLIGHTLY DURING THE DAY OVER THE TN VALLEY. THIS MCS ACTIVITY SHOULD PROPAGATE ESEWD...BECOMING REJUVENATED DURING THE DAY...ALONG FRONTAL ZONE THAT WILL PROVE MODERATELY UNSTABLE...DRAPED FROM MO ALONG THE KY/TN BORDER INTO THE CAROLINAS. THERMODYNAMIC PROFILES AND VERTICAL SHEAR SUGGEST POSSIBLE LONG-LIVED SEVERE THUNDERSTORM CLUSTERS WITH DAMAGING WINDS WHERE CONVECTION CAN INTERACT WITH WARM SECTOR BOUNDARY LAYER INSTABILITY. FRONTAL ZONE ACROSS NC WILL LIKELY BE ANOTHER ACTIVE ZONE FOR DAYTIME THUNDERSTORM DEVELOPMENT. STORM ORGANIZATION IS LIKELY ALONG SFC WIND SHIFT WHERE WNWLY FLOW AT MID LEVELS WILL LIKELY EXCEED 35-40KT. ...CNTRL/NRN HIGH PLAINS... WELL ENTRENCHED SFC RIDGE OVER THE PLAINS WILL MAINTAIN ELY COMPONENT TO BOUNDARY LAYER FLOW ACROSS THE HIGH PLAINS INTO THE EAST SLOPES OF THE MOUNTAINS FROM CO...NWD INTO SRN MT. DESPITE RISING HEIGHTS ALOFT...STRONG HEATING COMBINED WITH LOW LEVEL CONVERGENT UPSLOPE FLOW SHOULD GENERATE SCATTERED THUNDERSTORMS BY MID-LATE AFTERNOON. DEEP VEERING PROFILES AND MODEST VERTICAL SHEAR CERTAINLY SUGGEST SUPERCELLS ARE POSSIBLE...AT LEAST INITIALLY IN STORM EVOLUTION. SLOW ESEWD PROPAGATIONAL COMPONENT WILL LIMIT MAIN SEVERE THREAT TO THE HIGH PLAINS REGION. LARGE HAIL AND ISOLATED TORNADOES MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/10/2006  From swody2 at goshenarc.org Sat Jun 10 17:30:23 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 10 Jun 2006 13:30:23 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 101727 SWODY2 SPC AC 101726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT JUN 10 2006 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN WY SEWD INTO THE CENTRAL HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS SERN MO EWD TO THE CAROLINAS... ...SYNOPSIS... BELT OF 30-40KT WLY MID LEVEL FLOW...CURRENTLY LOCATED W-E ACROSS THE CENTRAL CONUS...WILL SHIFT NWD INTO THE NRN ROCKIES/PLAINS AS THE UPPER RIDGE BUILDS NWD ACROSS THE ROCKIES/PLAINS REGION. THIS WILL RESULT IN AMPLIFICATION OF UPPER TROUGHS ACROSS THE WRN AND ERN CONUS. QUASI-STATIONARY FRONT IS FORECAST TO EXTEND ALONG THE FOOTHILLS ON WY/CO EWD THROUGH NRN OK INTO THE TN VALLEY AND THE CAROLINAS THROUGH MOST OF THE PERIOD. ...SERN MO EWD TO THE CAROLINAS... A WEAKENING MCS IS EXPECTED TO BE ONGOING EARLY IN THE PERIOD ACROSS PORTIONS OF MO/IL AS LOW LEVEL JET WEAKENS AND VEERS. ONCE THIS COMPLEX WEAKENS OR PERHAPS EVEN DISSIPATES...CONVECTIVE INITIATION ACROSS THIS REGION IS SOMEWHAT UNCERTAIN AS HEIGHTS RISE SLIGHTLY AND LOW LEVEL WARM ADVECTION WEAKENS AS 20-25 KT WLY WINDS BECOME PARALLEL TO THE SURFACE BOUNDARY. STRONG HEATING MAY AID STORM INITIATION NEAR THE FRONT AND/OR FROM REMNANTS OF EARLIER MCS ACTIVITY. STORMS THAT DEVELOP WILL HAVE FAVORABLE INSTABILITY AND VERTICAL SHEAR TO PRODUCE DAMAGING WINDS AND SOME MARGINALLY SEVERE HAIL. ...ERN WY SEWD INTO THE CENTRAL HIGH PLAINS... LARGE SURFACE HIGH...LOCATED OVER THE GREATS LAKE AREA...WILL MAINTAIN DEEP ELY COMPONENT TO THE BOUNDARY LAYER FLOW ACROSS THE HIGH PLAINS AND ERN SLOPES OF ERN CO/WY. DESPITE RISING HEIGHTS ALOFT...STRONG HEATING COMBINED WITH CONVERGENT UPSLOPE FLOW AND MOISTENING BOUNDARY LAYER SHOULD AID IN THUNDERSTORMS DEVELOPING BY MID-LATE AFTERNOON. MID LEVEL FLOW ALOFT WILL BE ABOUT 15-20 KT WEAKER THAN TODAY...BUT STRONGLY VEERING WIND PROFILES AND 30 KT MID LEVEL WLY WINDS RESULT IN STRONGLY VEERING PROFILES...WHICH WOULD BE FAVORABLE FOR SUPERCELLS. THE STORMS SHOULD MOVE SEWD TOWARD THE STRONGER INSTABILITY...LIMITING THE MAIN SEVERE WEATHER THREAT TO THE HIGH PLAINS REGION. ALTHOUGH AN ISOLATED TORNADO IS POSSIBLE SHORTLY AFTER THE STORMS FIRST DEVELOP...THE SHEAR AND STEEP LAPSE RATES SUGGEST SEVERE HAIL SHOULD BE THE MAIN THREAT. ...FL PENINSULA... TROPICAL DEPRESSION #1 IS FORECAST TO BE LOCATED IN THE SERN GULF OF MEXICO DURING THIS PERIOD...WITH HIGH CHANCES OF THUNDERSTORMS ACROSS THE FL PENINSULA. KEY WEST VAD WIND PROFILE IS ALREADY SHOWING SELY WINDS AT 30-35 KT FROM THE SURFACE TO 4 KM AND DEPENDING ON THE ACTUAL TRACK AND STRENGTHENING OF THE SYSTEM... WINDS MAY STRENGTHEN ENOUGH FOR AN ISOLATED TORNADO THREAT WITHIN THE OUTER BANDS OF THE SYSTEM. REFER TO THE NATIONAL HURRICANE CENTER FOR THE LATEST ADVISORIES AND FORECASTS ON THIS TROPICAL SYSTEM. ..IMY.. 06/10/2006  From swody2 at goshenarc.org Sun Jun 11 05:41:57 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 11 Jun 2006 01:41:57 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 110539 SWODY2 SPC AC 110538 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CDT SUN JUN 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SERN U.S.... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN INTER MOUNTAIN REGION INTO MT... ...SERN U.S... LATEST MODEL GUIDANCE SUGGEST TROPICAL SYSTEM DEVELOPING OVER THE SRN GULF OF MEXICO WILL BE DRAWN INTO THE BASE OF LONG WAVE TROUGH OVER THE ERN U.S. AND LIFT NEWD TOWARD THE FL PENINSULA EARLY IN THE DAY2 PERIOD. GUIDANCE FROM THE HURRICANE CENTER INDICATES THIS FEATURE WILL GRADUALLY INCREASE AND POSSIBLY BECOME A TROPICAL STORM BEFORE LANDFALL. THIS EVOLUTION WILL RESULT IN INCREASINGLY SHEARED PROFILES ALONG THE FL PENINSULA AS SYSTEM ACCELERATES TOWARD THE WRN ATLANTIC...OFF THE CAROLINA COAST BY TUE MORNING. ISOLATED TORNADOES WILL BECOME MORE LIKELY TO THE EAST OF THE LOW TRACK AS CIRCULATION BECOMES ABSORBED IN THE BASE OF LONG WAVE TROUGH. ...NRN INTER MOUNTAIN REGION/NRN ROCKIES...HIGH PLAINS... SIGNIFICANT HEIGHT RISES WILL DEVELOP ACROSS MUCH OF THE WRN U.S. THIS PERIOD AS RIDGE BUILDS NWD ACROSS THE ROCKIES INTO ALBERTA/SASKATCHEWAN. LONG WAVE TROUGH ALONG THE PACIFIC COAST WILL PROGRESS LITTLE INLAND...ALTHOUGH AT LEAST ONE SIGNIFICANT MID LEVEL SPEED MAX WILL SPREAD INTO NV LATE IN THE PERIOD. A BELT OF MODERATE MID-HIGH LEVEL MERIDIONAL FLOW WILL BE MAINTAINED FROM SRN CANADA INTO ERN WA/ORE DURING THE PERIOD PROVIDING VERTICAL SHEAR NECESSARY FOR SUSTAINING ROBUST CONVECTIVE DEVELOPMENT. IN THE ABSENCE OF MEANINGFUL LARGE SCALE ASCENT...IT APPEARS STRONG HEATING/OROGRAPHIC LIFTING WILL PROVE BENEFICIAL IN GENERATING THUNDERSTORMS DURING THE AFTERNOON ACROSS THE NWRN U.S. MONDAY. CONVECTION SHOULD DEVELOP LATE...BUT LIKELY INCREASE IN INTENSITY OVER ERN ORE/WA ALONG FRONTAL ZONE WHERE SUPERCELL STRUCTURES ARE POSSIBLE. OTHER STORMS ARE POSSIBLE ACROSS WRN MT BY LATE AFTERNOON WHERE SIGNIFICANT ELY LOW LEVEL FLOW IS EXPECTED TO FORCE BOUNDARY LAYER MOISTURE DEEP INTO THE HIGHER ELEVATIONS. VERTICAL SHEAR PROFILES STRONGLY SUGGEST ANY THUNDERSTORM CLUSTERS THAT EVOLVE ACROSS WRN MT WILL BE MORE THAN ADEQUATELY SHEARED FOR SUPERCELL STRUCTURES. THIS ACTIVITY WOULD THEN MOVE NEWD TOWARD THE PLAINS WHERE STRONG LOW LEVEL SHEAR WILL ENHANCE INFLOW/FORWARD PROPAGATIONAL COMPONENT. MCS MAY EVOLVE ACROSS NWRN/NRN MT LATE IN THE PERIOD BEFORE SPREADING INTO SWRN SASKATCHEWAN AFTER MIDNIGHT. ..DARROW.. 06/11/2006  From swody2 at goshenarc.org Sun Jun 11 17:24:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 11 Jun 2006 13:24:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 111722 SWODY2 SPC AC 111721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT SUN JUN 11 2006 VALID 121200Z - 131200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE INTERIOR PAC NW INTO WRN MT... ...THERE IS A SLGT RISK OF SVR TSTMS SERN CO... ...THERE IS A SLGT RISK OF SVR TSTMS FL PENINSULA... ...SYNOPSIS... HIGHLY AMPLIFIED PATTERN IN WRN U.S. AS TROUGH REMAINS JUST OFF W COAST AND STRONG RIDGE BUILDS NWD OVER ROCKIES. TROUGH POSITION REMAINS ERN U.S. AS ONE S/WV TRACKS EWD TO SRN ENGLAND AND NEXT IN LINE DROPS SEWD FROM MANITOBA REACHING WRN GREAT LAKES BY 12Z TUE. NEWLY FORMED T.S. ALBERTO SERN GULF IS PROGGED TO HEAD FOR THE NERN GULF COAST BY LATE DY2. MODEL GUIDANCE SUGGEST THERE IS CONSIDERABLE UNCERTAINTY ABOUT THE FUTURE TRACK AND INTENSITY AT THE SURFACE HIGH PRESSURE GENERALLY OVER NCENTRAL U.S WHICH WILL MAINTAIN E/SELY FLOW CENTRAL AND NORTHERN HIGH PLAINS AND ACROSS NRN ROCKIES. ...PAC NW... WITH SUCH AMPLITUDE IN THE TROUGH/RIDGE WRN U.S...ONLY MINOR IMPULSES EXPECTED TO MOVE INLAND THIS FORECAST PERIOD. HOWEVER WITH A STRONG MID/UPPER LEVEL JET MAX MOVING FROM CENTRAL CA TOWARD ERN WA...DEEP LAYER SHEAR WILL BE QUITE FAVORABLE FOR ORGANIZED THUNDERSTORM POTENTIAL INTERIOR PAC NW...DEPENDENT ON THE QUALITY OF AIR MASS. WITH THE LOW LEVEL ELYS FROM NRN HIGH PLAINS FORECASTED TO EXTEND WWD ACROSS MT INTO NRN ID/ERN WA...MOISTURE ALONG WITH ENHANCED LOW LEVEL SHEAR SUFFICIENT FOR SUPERCELL POTENTIAL. HEATING COUPLED WITH TERRAIN EFFECTS SHOULD LEAD TO STORM DEVELOPMENT BY MID/LATE AFTERNOON ERN WA/NERN OR/NRN ID. GREATEST UNCERTAINTY IS DEGREE OF INSTABILITY...HOWEVER WITH LAPSE RATES AROUND 8C/KM AND 50-60 KT OF DEEP LAYER SHEAR...SEVERE STORMS ARE LIKELY WITH POTENTIAL FOR SUPERCELLS. SEVERE THREAT EXPECTED TO REMAIN PRIMARILY W OF DIVIDE GIVEN THE POSITION OF UPPER RIDGE OVER ROCKIES. EXCEPTION WOULD BE IF ANY MCS THAT EVOLVES OUT OF PAC NW STORMS COULD TRACK NEWD ACROSS NCENTRAL MT OVERNIGHT. ...FL PENINSULA... HAVE CONFINED THREAT FOR SEVERE THUNDERSTORMS ASSOCIATED WITH T.S. ALBERTO TO JUST FL PENINSULA DUE TO UNCERTAINTY IN BOTH TRACK AND SPEED OF STORM. TROPICAL AIR EXPECTED TO OVERSPREAD FL PENINSULA BY MON AND WITH MDTLY SHEARED ENVIRONMENT ON E SIDE OF ALBERTO...THREAT IS MAINTAINED FOR A SEVERE THREAT...BOTH ISOLATED TORNADOES AND WIND DAMAGE. ...ERN CO... E/SELY UPSLOPE FLOW WILL CONTINUE TO TRANSPORT SUFFICIENT MOISTURE FOR THUNDERSTORMS INTO ERN CO. WITH STRONG HEATING AND VERY STEEP LAPSE RATES...MLCAPES BY MID AFTERNOON WILL RANGE UPWARD FROM 1500 J/KG ALONG FRONT RANGE TO 2500 J/KG SERN PLAINS OF CO. DEEP LAYER SHEAR OF 30-40KT EXPECTED TO SUPPORT SUPERCELLS AS STORMS THAT DEVELOP OVER HIGHER TERRAIN PROPAGATE E/SEWD INTO PLAINS BY LATE AFTERNOON/EVENING. LARGE HAIL AND DOWNBURSTS PRIMARY CONCERN AS THE EXPECTED HIGH BASES WILL LIMIT TORNADO THREAT. ..HALES.. 06/11/2006  From swody2 at goshenarc.org Mon Jun 12 05:59:43 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 01:59:43 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120557 SWODY2 SPC AC 120556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1256 AM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR NW INTO ERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S.... ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... LARGE SCALE PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS AS UPPER RIDGE HOLDS FROM THE SRN ROCKIES INTO SASKATCHEWAN. MODEST MID-HIGH LEVEL MERIDIONAL FLOW ACROSS THE GREAT BASIN INTO WRN MT WILL PERSIST...AND INCREASE LATE IN THE PERIOD AS SPEED MAX LIFTS NEWD TOWARD ERN ID. ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE DAY...ESPECIALLY IN OROGRAPHICALLY FAVORED AREAS. THIS ACTIVITY WILL BE STRONGLY SHEARED...AND SUFFICIENTLY BUOYANT FOR POTENTIAL SUPERCELL DEVELOPMENT. DEEP ELY BOUNDARY LAYER FLOW ACROSS THE PLAINS OF MT WILL LIMIT LOW LEVEL HEATING AND SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL STORM ALBERTO IS EXPECTED TO EJECT NEWD ACROSS THE NRN FL PENINSULA DURING THE DAY2 PERIOD. THIS TRACK WILL OBVIOUSLY ALLOW SHEAR PROFILES TO INCREASE MARKEDLY ACROSS MUCH OF THE FL PENINSULA...ENHANCING THE POSSIBILITY FOR A FEW TORNADOES. ..DARROW.. 06/12/2006  From swody2 at goshenarc.org Mon Jun 12 06:07:40 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 02:07:40 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120605 SWODY2 SPC AC 120604 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0104 AM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR NW INTO ERN MT... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S.... ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... LARGE SCALE PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS AS UPPER RIDGE HOLDS FROM THE SRN ROCKIES INTO SASKATCHEWAN. MODEST MID-HIGH LEVEL MERIDIONAL FLOW ACROSS THE GREAT BASIN INTO WRN MT WILL PERSIST...AND INCREASE LATE IN THE PERIOD AS SPEED MAX LIFTS NEWD TOWARD ERN ID. ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE DAY...ESPECIALLY IN OROGRAPHICALLY FAVORED AREAS. THIS ACTIVITY WILL BE STRONGLY SHEARED...AND SUFFICIENTLY BUOYANT FOR POTENTIAL SUPERCELL DEVELOPMENT. DEEP ELY BOUNDARY LAYER FLOW ACROSS THE PLAINS OF MT WILL LIMIT LOW LEVEL HEATING AND SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL STORM ALBERTO IS EXPECTED TO EJECT NEWD ACROSS THE NRN FL PENINSULA DURING THE DAY2 PERIOD. THIS TRACK WILL OBVIOUSLY ALLOW SHEAR PROFILES TO INCREASE MARKEDLY ACROSS MUCH OF THE FL PENINSULA...ENHANCING THE POSSIBILITY FOR A FEW TORNADOES. ..DARROW.. 06/12/2006  From swody2 at goshenarc.org Mon Jun 12 17:26:31 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 12 Jun 2006 13:26:31 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121722 SWODY2 SPC AC 121721 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1221 PM CDT MON JUN 12 2006 VALID 131200Z - 141200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR PAC NW INTO ERN MT...... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN U.S...... ...SYNOPTIC DISCUSSION... LARGE SCALE FEATURES WILL MAKE ONLY SLOW EWD PROGRESS TUE. WHILE THE CIRCULATION CENTER OF NWRN U.S. TROUGH REMAINS NEAR THE MOUTH OF THE COLUMBIA RIVER...A STRONG MID/UPPER SPEED MAX ROTATES NEWD ACROSS INTERMOUNTAIN REGION REACHING NRN ROCKIES BY LATER TUE NIGHT. DOWNSTREAM RIDGE EXTENDS NWD FROM NM UPPER HIGH TO SASKATCHEWAN SHIFTING INTO HIGH PLAINS BY 12Z WED. ...NRN INTER MOUNTAINS...NRN ROCKIES/HIGH PLAINS... ALTHOUGH HEIGHT FALLS LATE IN THE PERIOD WILL FORCE SHARP BAROCLINIC ZONE EWD ACROSS ID INTO WRN MT...THE TIMING OF THIS FEATURE IS NOT PARTICULARLY CONDUCIVE FOR ENHANCING AFTERNOON CONVECTION OVER ERN PORTIONS OF THE SLIGHT RISK. EVEN SO...FORECAST SOUNDINGS ACROSS THE INTERIOR NW SUGGEST THUNDERSTORMS SHOULD DEVELOP DURING THE HEAT OF THE AFTERNOON AHEAD OF THE COLD FRONT FROM NWRN MT AT LEAST AS FAR S AS SWRN ID. THIS ACTIVITY WILL BE STRONGLY SHEARED. LIMITATION...PARTICULARLY SRN ID AREA WILL BE MOISTURE/INSTABILITY. ACROSS MT DEEP ELY BOUNDARY LAYER FLOW WILL PROVIDE SIGNIFICANTLY GREATER MOISTURE AND POTENTIAL INSTABILITY. STORM MODE SRN PORTION OF SLIGHT SHOULD BE HIGH BASED MULTI-CELLS LIMITING POTENTIAL TO WIND DAMAGE AND MARGINAL HAIL. WITH POTENTIALLY SIGNIFICANTLY GREATER INSTABILITY AND VEERING LOW LEVEL SHEAR ENVIRONMENT WRN MT...SUPERCELLS WILL BE POSSIBLE. THIS WILL ENHANCE... PARTICULARLY LARGE HAIL THREAT WITH POSSIBLE ISOLATED TORNADOES. ACROSS THE PLAINS OF MT WITH MORE LIMITED LOW LEVEL HEATING...SFC PARCELS MAY REMAIN SLIGHTLY CAPPED THROUGH EARLY EVENING. HOWEVER...APPROACHING SPEED MAX SHOULD MAINTAIN CONVECTION ACROSS ID/WRN MT WITH ACTIVITY POSSIBLY SPREADING ACROSS THE PLAINS OF MT DURING THE OVERNIGHT HOURS WHERE STRONG SELY LLJ IS EXPECTED TO RESPOND TO THE APPROACHING UPPER TROUGH. FARTHER SOUTHEAST...THUNDERSTORM DEVELOPMENT IS POSSIBLE ALONG SFC FRONT DRAPED FROM NERN WY INTO SWRN MN. THIS BOUNDARY WILL PROVE CONVERGENT AT LOW LEVELS...BUT LARGE SCALE SUBSIDENCE ALOFT BENEATH UPPER RIDGE WILL PROVE SOMEWHAT PROBLEMATIC MAINTAINING ANY UPDRAFTS THAT MANAGE TO BREAK CAP. THIS ACTIVITY WILL LIKELY REMAIN ISOLATED THROUGH EARLY EVENING...THEN POSSIBLY EXPAND IN AREAL COVERAGE AS LLJ INCREASES AFTER DARK. GIVEN THE EXPECTED LATE DEVELOPMENT BENEATH UPPER RIDGE WILL MAINTAIN LOW PROBABILITIES FOR THIS CONVECTION. ...SERN U.S... TROPICAL AIR WILL CONTINUE SPREADING NWD AS T.S. ALBERTO HEADS TOWARD LANDFALL NERN GULF COAST. REF NHC PRODUCTS FOR TRACK AND LANDFALL TIMING. FAVORABLE SHEAR WILL MAINTAIN POTENTIAL FOR TORNADIC SUPERCELLS AHEAD OF THE TRACK OF ALBERTO. ..HALES.. 06/12/2006  From swody2 at goshenarc.org Tue Jun 13 05:59:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 13 Jun 2006 01:59:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 130556 SWODY2 SPC AC 130555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT TUE JUN 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NRN PLAINS... ...NRN ROCKIES/NRN PLAINS... UPPER RIDGE WILL BE SHUNTED EAST ACROSS THE NRN HIGH PLAINS DURING THE DAY2 PERIOD AS STRONGER FLOW TRANSLATES ACROSS THE GREAT BASIN INTO ERN MT...ON DOWNSTREAM SIDE OF UPPER TROUGH. SWLY FLOW ACROSS THE HIGHER TERRAIN OF THE NRN...AND ESPECIALLY THE CENTRAL ROCKIES...WILL GENERATE SUBSTANTIAL CAPPING ATOP MODESTLY MOIST BOUNDARY LAYER. WHILE WARM SECTOR THUNDERSTORMS WILL STRUGGLE TO DEVELOP SOUTH OF I-70 OVER NEB...IT APPEARS STRONG HEATING IN THE LEE OF THE NRN ROCKIES WILL WEAKEN CAP ALLOWING SFC PARCELS TO REACH THEIR LFC. THIS APPEARS LIKELY ACROSS MT...SEWD TO POSSIBLY NEAR THE BLACK HILLS REGION OF WRN SD. LATEST THINKING IS SEVERE THUNDERSTORMS...INITIALLY SUPERCELLULAR...WILL EVOLVE AHEAD OF SFC LOW OVER SERN MT THEN SPREAD ENEWD TOWARD WRN ND...DEVELOPING SWD INTO WRN SD AS THE EVENING PROGRESSES. INCREASING LLJ AFTER DARK WILL MOST LIKELY AID MCS DEVELOPMENT AS THUNDERSTORM CLUSTERS SPREAD INTO THE NRN PLAINS. HIGH TEMP/DEW POINT SPREADS MAY SUPPORT DAMAGING WINDS WITH BOW ECHO-TYPE STRUCTURES...IN ADDITION TO LARGE HAIL. ...COASTAL CAROLINAS... ALBERTO IS EXPECTED TO LIFT NEWD ALONG THE SC/NC COAST DURING THE DAY2 PERIOD. STRONGER SHEAR MORE FAVORABLE FOR SUPERCELLS SHOULD HOLD JUST OFFSHORE...ALTHOUGH UNCERTAINTY IN TRACK WILL REQUIRE AT LEAST LOW PROBABILITIES FOR ISOLATED TORNADOES NEAR THE REMNANT CIRCULATION. ..DARROW.. 06/13/2006  From swody2 at goshenarc.org Tue Jun 13 17:39:49 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 13 Jun 2006 13:39:49 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131737 SWODY2 SPC AC 131735 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1235 PM CDT TUE JUN 13 2006 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN ROCKIES TO NRN PLAINS... ...SYNOPSIS... STRONGLY AMPLIFIED BUT RELATIVELY PROGRESSIVE UPPER FLOW WILL PERSIST ACROSS THE CONUS THROUGH MIDWEEK. AN IMPULSE ROUNDING THE BASE OF THE ELONGATED WEST COAST TROUGH IS FORECAST TO PIVOT NEWD AND PRODUCE MODERATE HEIGHT FALLS FROM THE NRN GREAT BASIN TO THE NRN HIGH PLAINS INTO EARLY THURSDAY. MEANWHILE...UPPER RIDGE CURRENTLY SITUATED ACROSS THESE AREAS WILL SHIFT EWD OVER THE PLAINS STATES THROUGH THE PERIOD...AND EXTEND NWD INTO SCNTRL CANADA. CIRCULATION ASSOCIATED WITH T.D. ALBERTO WILL BECOME INCREASINGLY ABSORBED BY THE WLYS WHICH WILL ACT TO ACCELERATE THE REMAINS OF THE TROPICAL SYSTEM NEWD ACROSS THE CAROLINAS EARLY IN THE PERIOD. THIS WILL OCCUR AHEAD OF SHORT WAVE TROUGHING DEVELOPING SEWD ACROSS THE OH VALLEY AND NORTHEAST AND CONTRIBUTING TO THE AMPLIFICATION OF THE MEAN UPPER TROUGH COVERING THE ERN U.S. ...NRN ROCKIES/NRN PLAINS... POTENT LARGE SCALE FORCING FOR ASCENT WILL ACCOMPANY THE IMPULSE EJECTING NEWD FROM THE NRN GREAT BASIN EARLY IN THE DAY. THIS WILL LIKELY SUSTAIN TSTMS ACROSS THE HIGHER TERRAIN THROUGH THE MORNING...WITH THIS ACTIVITY SPREADING ACROSS THE CONTINENTAL DIVIDE AND INTO CNTRL MT BY AFTERNOON. SHARPENING LEE-TROUGH WILL ENHANCE UPSLOPE FLOW AND ACT TO FOCUS GREATER LOW LEVEL MOISTURE BENEATH THE STRONG CAP FROM CNTRL MT/NRN WY EWD TO THE NRN HIGH PLAINS WHERE STRONG DESTABILIZATION WILL TAKE PLACE. AS DIFFLUENT MID LEVEL FLOW AND HEIGHT FALLS SPREAD ATOP THE CAPPED INSTABILITY AXIS THROUGH LATE AFTERNOON...OROGRAPHIC AND DIABATIC FORCING WILL CONTRIBUTE TO WEAKENING THE CAP SUFFICIENTLY FOR STORM INTENSIFICATION FROM NRN WY ACROSS THE ERN HALF OF MT. DIRECTIONAL AND VERTICAL SPEED SHEAR FORECAST ACROSS THE REGION WILL PROVE MORE THAN ADEQUATE FOR SUPERCELLS WITH GOOD POTENTIAL FOR LARGE HAIL...HIGH WINDS...AND PERHAPS A COUPLE TORNADOES. LARGE SCALE FORCING AND FORECAST EVOLUTION OF CONVECTION STRONGLY SUGGESTS THAT AN FORWARD PROPAGATING MCS OR TWO SHOULD DEVELOP EAST INTO THE DAKOTAS THROUGH LATE EVENING. DEGREE OF POTENTIAL INSTABILITY FEEDING INTO THIS ACTIVITY ON PLAINS LOW LEVEL JET SHOULD MAINTAIN THE THREAT FOR SEVERE WEATHER EAST ACROSS THE NRN PLAINS WELL INTO EARLY THURSDAY. ...CAROLINAS... STRONG LOW LEVEL SHEAR WITHIN RIGHT FRONT QUADRANT OF ALBERTO CIRCULATION WILL DEVELOP ACROSS THE ERN CAROLINAS DURING THE DAY. RECENT FRONTAL PASSAGE ACROSS THE AREA HAS BROUGHT IN LOWER DEWPOINTS/MORE STABLE AIR MASS. DESPITE STRONG MOISTURE ADVECTION AHEAD OF THE TROPICAL SYSTEM...WIDESPREAD PRECIPITATION IN ADVANCE OF THE LOW MAY KEEP DESTABILIZATION LIMITED GIVEN ANTECEDENT RELATIVELY DRY BOUNDARY LAYER. WHILE AN ISOLATED/BRIEF TORNADO CANNOT BE RULED OUT WITH SUCH A SYSTEM...POTENTIAL FOR WEAK INSTABILITY PRECLUDES GREATER PROBABILITIES AT THIS TIME. STRONGER INSTABILITY MAY...HOWEVER...DEVELOP IN THE WAKE OF ALBERTO...ACROSS SRN NC/SC...AS SKIES CLEAR DURING THE AFTERNOON. INCREASING WLY FLOW ACROSS THE REGION AHEAD OF OH VALLEY/SRN APPALACHIANS SHORT WAVE TROUGH COULD PROMOTE SCATTERED ORGANIZED STORMS OVER PARTS OF THE REGION BY LATE AFTERNOON/EARLY EVENING. A SMALL CLUSTER OF SEVERE STORMS APPEARS POSSIBLE FROM SERN NC ACROSS ERN SC DURING THIS TIME FRAME. IF THIS SIGNAL REMAINS COHERENT IN LATER FORECASTS...SEVERE PROBABILITIES MAY NEED TO BE INCREASED OVER PARTS OF THE AREA. ...MO VALLEY TO MIDWEST... BAND OF SCATTERED CONVECTION MAY BE ONGOING FROM ERN SD...ACROSS PARTS OF IA...AND INTO SRN WI/NRN IL...WITHIN WARM CONVEYOR ON THE EDGE OF THE CAP EARLY WEDNESDAY. IT IS POSSIBLE THAT SOME OF THIS ACTIVITY MAY ROOT INTO MARGINALLY UNSTABLE BOUNDARY LAYER FROM SRN WI INTO NRN IL/NWRN IND DURING THE DAY AND INTO THE EVENING. THIS ACTIVITY MIGHT BE FURTHER SUSTAINED BY STRONGER SHEAR/FORCING ASSOCIATED WITH A SHORT WAVE DEVELOPING SEWD ACROSS THE REGION. LATEST NAM-WRF INDICATES THE POTENTIAL FOR A FEW SEVERE STORMS WHILE NAM-ETA IS NOT AS STRONG WITH THE MID LEVEL IMPULSE. GIVEN THESE DIFFERENCES...WILL ONLY OUTLOOK LOW SEVERE PROBABILITIES AT THIS TIME. ...MID ATLANTIC/NORTHEAST... FORCING ASSOCIATED WITH OH VALLEY SHORT WAVE WILL CONTRIBUTE TO SCATTERED TSTM DEVELOPMENT WITHIN WEAKLY UNSTABLE AIR MASS FROM WV/NRN VA NEWD TO NEW ENGLAND DURING THE AFTERNOON. WHILE FORCING AND SHEAR APPEAR SUPPORTIVE OF A FEW STORMS WITH MARGINALLY SEVERE HAIL OR ISOLATED DAMAGING WINDS...LACK OF STRONGER DESTABILIZATION SHOULD PREVENT THESE THREATS FROM BECOMING MORE WIDESPREAD. ..CARBIN.. 06/13/2006  From swody2 at goshenarc.org Wed Jun 14 06:06:45 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 14 Jun 2006 02:06:45 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140603 SWODY2 SPC AC 140602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT WED JUN 14 2006 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...NORTHERN/CENTRAL PLAINS... UPPER TROUGH OVER THE INTER MOUNTAIN WEST WILL SHIFT EWD ACROSS THE ROCKIES SPLITTING INTO TWO DISTINCT FEATURES THURSDAY. A SIGNIFICANT UPPER SPEED MAX WILL DIG SEWD ACROSS NV INTO AZ/NM FORCING HEIGHT FALLS INTO THE SRN ROCKIES...WHILE NRN MORE PERSISTENT MID LEVEL CIRCULATION WILL SHIFT EAST ALONG THE U.S./CANADIAN BORDER. LATEST MODEL GUIDANCE SEEM A BIT AGGRESSIVE IN BOUNDARY LAYER MOISTURE RECOVERY ACROSS THE ERN DAKOTAS/MN WHERE SFC DEW POINTS ARE FORECAST TO RISE INTO THE UPPER 60S. OF PARTICULAR CONCERN FOR MUCH OF THE PLAINS IS THE PERSISTENT WARMTH AT 700 MB. DNR SOUNDING THIS EVENING WAS QUITE WARM WITH 20C...WHILE RIW WAS 17C. THIS HEAT PLUME WILL ADVECT ACROSS THE PLAINS AS AN ELEVATED MIXED LAYER THAT SHOULD IMPEDE BOUNDARY LAYER CONVECTION MUCH OF THE AFTERNOON. STRONG HEATING WILL CERTAINLY PROVE BENEFICIAL IN BREAKING THIS CAP ALONG ADVANCING WIND SHIFT IN THE ABSENCE OF STRONG FORCING. TWO REGIONS WHERE STRONGER FORCING SEEM POSSIBLE ARE ACROSS SRN CANADA...THEN LATER IN THE EVENING ALONG NOSE OF STRENGTHENING LLJ OVER THE PLAINS. LATE EVENING THUNDERSTORM ACTIVITY SEEMS LIKELY ALONG/NORTH OF THE BOUNDARY FROM NEB INTO SERN SD. OTHERWISE...ISOLATED DAYTIME STORMS ARE POSSIBLE WHERE STRONG HEATING OCCURS. UNCERTAINTY IN CONVECTIVE MODE COMBINED WITH STRONG CAP LEND ENOUGH UNCERTAINTY IN SEVERE EVOLUTION TO MAINTAIN LOW PROBABILITIES AT THIS TIME. HOWEVER...SUFFICIENT VERTICAL SHEAR WILL SPREAD ACROSS THE BOUNDARY FOR THE POTENTIAL FOR ORGANIZED ACTIVITY. WILL MONITOR THIS REGION FOR POSSIBLE UPGRADE IN LATER OUTLOOKS. ..DARROW.. 06/14/2006  From swody2 at goshenarc.org Wed Jun 14 17:30:20 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 14 Jun 2006 13:30:20 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141726 SWODY2 SPC AC 141726 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT WED JUN 14 2006 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MIDWEST SWWD INTO THE CENTAL HIGH PLAINS... ...SYNOPSIS... UPPER TROUGH...CURRENTLY LOCATED ACROSS THE INTERMOUNTAIN WEST ...IS EXPECTED TO MOVE EWD INTO THE ROCKIES AND NRN/CENTRAL PLAINS ON THURSDAY. WHILE THE MODELS ARE CONSISTENT IN A CLOSED LOW DEVELOPING WITHIN THE TROUGH NORTH OF MT...A STRONG SHORTWAVE TROUGH AND ASSOCIATED SPEED MAX WILL DIG SEWD ACROSS NV INTO AZ/NM. ALTHOUGH THE COLD FRONT IS FORECAST TO EXTEND FROM CENTRAL ND/SD SWWD INTO NERN CO AT THE START OF THE PERIOD...THE FRONT SHOULD EDGE ONLY SLOWLY EWD DURING THE PERIOD AS THE SWLY MID LEVEL WINDS ALOFT...PARALLEL TO THE FRONT... STRENGTHEN TO 50-60 KT. ...NORTHERN PLAINS AND UPPER MIDWEST... A WEAKENING MCS MAY BE ONGOING AT THE START OF THE PERIOD ACROSS PORTIONS OF ND. HOWEVER...THE REMNANTS OF THIS CONVECTION AND A POSSIBLE MCV...MAY INTENSIFY DURING THE AFTERNOON ACROSS MN/NWRN WI AS THE UPPER LEVEL DIFFLUENCE STRENGTHENS ALONG WITH WEAK LOW LEVEL WARM ADVECTION. THE FORECAST OF UPPER 60 DEWPOINTS ARE LIKELY OVERESTIMATED OR SHOULD BE CONFINED CLOSE TO THE SURFACE ...BUT LOWER 60 DEWPOINTS AND STEEP MID LEVEL LAPSE RATES WILL RESULT IN MLCAPES FROM 1500-2000 J/KG. STORM MODE IS UNCERTAIN... BUT SELY BOUNDARY LAYER WINDS VEERING TO WLY SHOULD PROVIDE SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS. THE RELATIVELY DRY BOUNDARY INDICATES THAT LARGE HAIL AND WIND DAMAGE WOULD BE THE MAIN THREAT WITH THESE STORMS. ALTHOUGH THE COLD FRONT IS EXPECTED TO BE LOCATED ACROSS ERN ND/SD DURING THE AFTERNOON...ALONG WITH AT LEAST MODERATE INSTABILITY... WEAKENING CONVERGENCE AND MORNING CONVECTIVE OUTFLOW BOUNDARIES MAY INHIBIT STORM DEVELOPMENT DURING THE AFTERNOON. IF STORMS ARE ABLE TO DEVELOP...THE DEGREE OF INSTABILITY AND SHEAR WOULD SUPPORT A SEVERE THREAT. ...CENTRAL AND ERN NEB/NWRN KS/ERN CO... MODELS ARE REMARKABLY SIMILAR IN INITIATING STORMS ALONG THE FRONT IN THE NWRN KS AREA BY LATE AFTERNOON...AND THIS APPEARS REASONABLE AS LARGE SCALE LIFT INCREASES WITH SHORTWAVE TROUGH APPROACHING FROM THE AZ/NM AREA. THE STORMS ARE ALSO LIKELY TO DEVELOP NEWD ALONG THE FRONT ACROSS NEB AS THE FORCING SPREADS NEWD. ALTHOUGH LOWER 60 DEWPOINTS ARE CURRENTLY STREAMING NWD FROM SRN TX INTO WRN KS...STRONG HEATING AND A LARGE AMOUNT OF DRY AIR FROM BETWEEN 800 AND 600 MB...IS LIKELY TO RESULT IN DEWPOINTS LOWERING INTO THE 50S. THESE DEWPOINTS AND VERY STEEP LAPSE RATES SHOULD STILL RESULT IN MLCAPES AROUND 1500 J/KG BY LATE AFTERNOON. VEERING WIND PROFILES AND STRENGTHENING MID LEVEL WINDS WILL BE FAVORABLE FOR STORMS WITH ROTATION. THE FORECAST OF INVERTED-V SOUNDINGS FROM THE SURFACE TO 600 MB SUGGESTS THAT WIND DAMAGE WILL BE THE MAIN THREAT. ..IMY.. 06/14/2006  From swody2 at goshenarc.org Thu Jun 15 06:06:34 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 15 Jun 2006 02:06:34 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150603 SWODY2 SPC AC 150602 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT THU JUN 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE TO THE UPPER MS VALLEY... ...CNTRL/SRN HIGH PLAINS... LATEST MODEL GUIDANCE CONTINUES TO SUGGEST WRN U.S. TROUGH WILL SPLIT WITH SIGNIFICANT AMOUNT OF DIGGING EXPECTED ACROSS THE 4-CORNERS INTO THE SRN HIGH PLAINS BY THE END OF THE PERIOD. MODELS HAVE BEEN CONSISTENT WITH THIS EVOLUTION ALTHOUGH THE CONVECTIVE SCENARIO REMAINS SOMEWHAT COMPLEX AS VERY WARM AIR AT 700MB HAS YET TO BE DISPLACED...EITHER THROUGH EXTENSIVE CONVECTIVE OVERTURNING...OR THROUGH LARGE SCALE ASCENT. IT APPEARS THICKNESSES WILL COOL SUFFICIENTLY OVER THE NEXT FEW DAYS FOR SEVERAL CONVECTIVE EPISODES ALONG/POST FRONTAL FROM ERN CO INTO NEB. THIS SHOULD FORCE SFC FRONT SWD ACROSS THE HIGH PLAINS WHERE BOUNDARY LAYER MOISTURE SHOULD RETURN TO UPSLOPE REGIONS OF ERN CO...TO THE NW OF LEE CYCLONE OVER THE TX PANHANDLE. LATEST THINKING IS THUNDERSTORMS MAY BE ONGOING EARLY IN THE PERIOD ALONG FRONTAL ZONE ACROSS NEB INTO NWRN KS. THIS ACTIVITY MAY GENERATE ISOLATED LARGE HAIL...BUT OTHERWISE SPREAD NEWD ALONG EXISTING CONVERGENCE ZONE WITH LITTLE WARM SECTOR PROPAGATION. LATER IN THE DAY STRONG HEATING ACROSS THE HIGH PLAINS FROM THE TX PANHANDLE INTO SERN CO SHOULD PROVE ADEQUATE FOR SFC PARCELS TO REACH THEIR LFC...ESPECIALLY AS MID LEVELS COOL BENEATH UPPER TROUGH. SEVERE THUNDERSTORMS SHOULD EVOLVE BENEATH MODEST MID-HIGH LEVEL FLOW ALONG DRY LINE...AND ACROSS UPSLOPE REGIONS INTO WRN KS/ERN CO. THIS ACTIVITY WILL GRADUALLY SPREAD EWD DURING THE EVENING HOURS INTO WRN OK/CNTRL KS AS LLJ SHIFTS INTO THE SRN PLAINS AFTER DARK. ...NRN MS VALLEY... 00Z NAM IS A BIT MORE AGGRESSIVE WITH WEAK HEIGHT FALLS ACROSS THE UPPER MS VALLEY REGION FRIDAY...WHILE GFS IS NEUTRAL DURING THE DAYTIME WITH HEIGHT CHANGES AHEAD OF SASKATCHEWAN/ALBERTA SHORTWAVE TROUGH. IDENTIFYING A PARTICULAR TIME FOR HEIGHTENED THUNDERSTORM DEVELOPMENT IS PROVING QUITE DIFFICULT ACROSS THIS REGION AS LOW LEVEL WARM ADVECTION WILL LIKELY ENHANCE EARLY MORNING DEVELOPMENT ALONG FRONTAL ZONE FROM SERN SD INTO MN. WHILE DAYTIME HEATING SHOULD AID ADDITIONAL DEVELOPMENT ALONG SFC WIND SHIFT/OUTFLOW DEMARKATION...FORCING AHEAD OF CANADIAN TROUGH DOES NOT APPEAR PARTICULARLY STRONG ACROSS THE NRN U.S. ISOLATED SEVERE WIND GUSTS MAY BE THE GREATEST RISK OF SEVERE WITH ANY BOW-TYPE ECHOES THAT CAN EVOLVE AND BECOME ORIENTED PERPENDICULAR TO MEAN SWLY WIND VECTORS. ..DARROW.. 06/15/2006  From swody2 at goshenarc.org Thu Jun 15 17:37:37 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 15 Jun 2006 13:37:37 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 151734 SWODY2 SPC AC 151733 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1233 PM CDT THU JUN 15 2006 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX PANHANDLE TO THE UPPER MS VALLEY...... ...SYNOPSIS... LARGE SCALE UPPER TROUGH NOW OVER THE WEST WILL MOVE EAST TO THE PLAINS/UPPER MS VALLEY FRIDAY AS A BELT OF FAST WLY FLOW MOVES INLAND OVER THE PACIFIC NORTHWEST/NRN ROCKIES...AND SHORT WAVE RIDGING DEVELOPS OVER THE GREAT BASIN/FOUR CORNERS. THE WRN TROUGH WILL DEVELOP EAST IN ESSENTIALLY TWO SEGMENTS AS A STRONG DOWNSTREAM RIDGE PERSISTS OVER THE ERN GREAT LAKES...MIDWEST...AND SOUTH. A MORE PROGRESSIVE NRN SEGMENT OF THE TROUGH...WITH STRONGER HEIGHT FALLS...WILL EVOLVE FROM THE CLOSED LOW CURRENTLY SITUATED ACROSS NRN MT/SRN ALBERTA. THIS DISTURBANCE WILL BE EJECTED EWD FROM THE NRN PLAINS TO THE UPPER MS VALLEY AND SCNTRL CANADA AS RELATIVELY FAST UPSTREAM WLY FLOW AND PACIFIC IMPULSE MOVE INLAND ACROSS THE NRN ROCKIES. THE SLOWER AND MORE AMPLIFIED SRN SEGMENT OF THE TROUGH...CURRENTLY CROSSING THE SWRN U.S...WILL TRANSLATE EWD FROM THE FOUR CORNERS TO THE CNTRL/SRN PLAINS THROUGH EARLY SATURDAY. MID LEVEL CIRCULATION...CURRENTLY EMBEDDED IN DEEP LAYER ELY FLOW ACROSS THE LOWER RIO GRANDE VALLEY...WILL BE INFLUENCED AND EVENTUALLY DIRECTED NEWD ACROSS THE ARKLATEX BY THE APPROACHING PLAINS TROUGH. AN EXTENSIVE BELT OF SWLY/SLY LOW LEVEL FLOW WILL PRECEDE MID LEVEL HEIGHT FALLS AND ASSOCIATED FRONT SPREADING EAST ACROSS THE PLAINS/UPPER MS VALLEY THROUGH THE PERIOD. THIS LOW LEVEL FLOW WILL MAINTAIN A VERY WARM AND MODESTLY MOIST BOUNDARY LAYER FROM THE GULF TO THE WRN GREAT LAKES ON FRIDAY...BENEATH A RELATIVELY STRONG CAP. MOST VIGOROUS CONVECTIVE DEVELOPMENT WILL OCCUR WHERE STRONGER FORCING ASSOCIATED WITH MODEST HEIGHT FALLS...LOW LEVEL JET...AND FRONTAL LIFT CAN ACT TO OVERCOME THE CAP. ...CNTRL/SRN PLAINS... A COUPLE OF CLUSTERS OF STORMS ARE EXPECTED TO BE ONGOING EARLY FRIDAY MORNING ACROSS THE CNTRL PLAINS FROM SD/NEB SWWD TO ERN CO AND PERHAPS WRN KS. CLOUDS AND OUTFLOW FROM THIS ACTIVITY WILL EFFECTIVELY REDEFINE THE DEEP LAYER SYNOPTIC FRONTAL ZONE ASSOCIATED WITH THE LARGER SCALE TROUGH DEVELOPING EAST ACROSS THE ROCKIES. INFLUENCE OF PRESSURE FALLS ASSOCIATED WITH LEE/FRONTAL WAVE DEVELOPMENT ACROSS THE HIGH PLAINS WILL MAINTAIN MASS INFLOW ACROSS THE BOUNDARY FROM KS TO NEB. STRONG DIURNAL DESTABILIZATION OF INFLOW AIR MASS...AND DIFFERENTIAL HEATING ACROSS THE BOUNDARY...WILL OVERCOME WARM SECTOR INHIBITION TO SUPPORT SURFACE-BASED TSTMS WITHIN STRONGLY UNSTABLE AIR MASS ACROSS KS/NEB THROUGH THE AFTERNOON. ADDITIONAL TSTM DEVELOPMENT APPEARS LIKELY AS DRYLINE MIXES EAST ACROSS THE TX/OK PNHDLS/SWRN KS DURING THE AFTERNOON. MOIST POST-FRONTAL UPSLOPE FLOW FROM WRN NEB INTO ERN CO WILL SUPPORT/MAINTAIN TSTMS ACROSS THESE AREAS WHERE INSTABILITY MAY BE MORE LIMITED DUE TO EARLY CONVECTION/CLOUD COVER. MID LEVEL SLY FLOW IS EXPECTED TO STRENGTHEN THROUGH THE DAY OVER THE PLAINS AND RESULT IN SUFFICIENT SHEAR FOR STORM PERSISTENCE/ORGANIZATION AS MID/UPPER TROUGH SPREADS EAST. FORCING/ORGANIZATION ASSOCIATED WITH THE LARGER SCALE FRONT/OUTFLOW/DRYLINE AND FRONTAL WAVES WILL LIKELY RESULT IN ORGANIZED CLUSTERS OF STORMS/EMBEDDED SUPERCELLS WITH HAIL/WIND AND SOME TORNADO POTENTIAL. MORE DISCRETE STORMS MAY INITIALLY BE POSSIBLE NEAR THE DRYLINE GIVEN STRONGER CAPPING IN THIS ENVIRONMENT. AN MCS OR TWO APPEAR LIKELY TO EVOLVE FROM LATE AFTERNOON CONVECTION AND SPREAD ESEWD OVER KS/OK AS DESTABILIZATION/INFLOW IS MAINTAINED BY BOTH LARGE SCALE HEIGHT FALLS AND LOW LEVEL JET...AS WELL AS LIFT ALONG POTENTIALLY EXTENSIVE CONVECTIVE COLD POOL. ...UPPER MS VALLEY... MORE PROGRESSIVE NATURE OF THE NRN SEGMENT OF THE TROUGH SHOULD PROMOTE FRONTAL ADVANCE FROM THE DAKOTAS EWD TO MN. LIFT WITHIN WARM CONVEYOR BELT AHEAD OF THE FRONT...FROM ERN SD ACROSS MN INTO WI...SHOULD SUPPORT ONE OR TWO AREAS OF ACTIVE CONVECTION STRENGTHENING AS GREATER INSTABILITY IS TAPPED DURING THE DAY. POTENTIAL FOR FRONTAL WAVES AND PREFERENTIALLY ORIENTED CONVECTIVE OUTFLOWS WITHIN INCREASINGLY UNSTABLE AND SHEARED ENVIRONMENT WILL RESULT IN A NUMBER OF ORGANIZED STORMS/SUPERCELLS WITH HAIL/WIND AND TORNADO POTENTIAL. ..CARBIN.. 06/15/2006  From swody2 at goshenarc.org Fri Jun 16 05:53:18 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 16 Jun 2006 01:53:18 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160550 SWODY2 SPC AC 160549 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1249 AM CDT FRI JUN 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS SAT/SAT NIGHT ACROSS PARTS OF THE CNTRL/SRN PLAINS.... MODELS INDICATE THAT A TRANSITION TOWARD A LESS AMPLIFIED UPPER FLOW REGIME WILL BEGIN DURING THIS FORECAST PERIOD...WITH STRONGER WESTERLIES GRADUALLY DEVELOPING NORTHWARD THROUGH THE NORTHWESTERN/ NORTH CENTRAL U.S. INTO SOUTHEASTERN CANADA. WITHIN THIS REGIME...A CLOSED LOW WILL ACCELERATE EASTWARD ALONG THE CENTRAL CANADIAN/U.S. BORDER TODAY...IN RESPONSE TO A RAPIDLY APPROACHING UPSTREAM SHORT WAVE TROUGH. A SIGNIFICANT IMPULSE EMBEDDED WITHIN THE BROADER SCALE CIRCULATION IS PROGGED TO LIFT AWAY FROM THE INTERNATIONAL BORDER TOWARD HUDSON/JAMES BAY EARLY SATURDAY. HOWEVER...MODELS SUGGEST REMNANTS OF CLOSED LOW AND UPSTREAM IMPULSE WILL CONSOLIDATE INTO ANOTHER BROADER SCALE TROUGH...WHICH WILL CONTINUE EASTWARD TOWARD CONFLUENT REGIME OVER THE UPPER GREAT LAKES REGION LATER SATURDAY INTO EARLY SUNDAY. FARTHER SOUTH...MID-LEVEL HEIGHT RISES ARE PROGGED THROUGH MUCH OF THE CENTRAL/SOUTHERN TIER OF THE U.S...AS SUBTROPICAL RIDGING BEGINS TO DEVELOP NORTHWARD. A SHORT WAVE TROUGH WILL PROGRESS EAST OF THE SOUTHERN ROCKIES THROUGH MUCH OF THE SOUTHERN PLAINS BY LATE SATURDAY/EARLY SUNDAY. THIS SYSTEM WILL WEAKEN BETWEEN UPPER HIGH CENTERS DEVELOPING INTO THE EASTERN AND SOUTHWESTERN STATES. HOWEVER...FORCING ASSOCIATED WITH THIS FEATURE...AND REMNANTS OF A DOWNSTREAM WAVE SLOWLY LIFTING OUT OF THE WESTERN GULF COAST REGION...ARE EXPECTED TO CONTRIBUTED TO CONSIDERABLE CONVECTIVE DEVELOPMENT OVER A BROAD AREA OF THE CENTRAL U.S. DURING THIS FORECAST PERIOD. THE MOST VIGOROUS THUNDERSTORMS ARE EXPECTED TO GENERALLY BE FOCUSED NEAR A LEE SURFACE TROUGH ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS. ...CENTRAL/SOUTHERN PLAINS... VARIABILITY EXISTS AMONG THE MODELS CONCERNING THE TRACK OF THE MID-LEVEL COLD CORE...BUT A LARGE CONVECTIVE CLUSTER COULD BE ONGOING EARLY SATURDAY IN ASSOCIATION WITH THIS FEATURE ACROSS THE CENTRAL/SOUTHERN HIGH PLAINS. THIS SEEMS MOST LIKELY ACROSS PARTS OF CENTRAL KANSAS/WESTERN OKLAHOMA INTO NORTHWEST TEXAS. ALONG/AHEAD OF ASSOCIATED SURFACE COLD POOL...AND SOUTHWARD ALONG SURFACE TROUGH/DRY LINE THROUGH WESTERN TEXAS...LAPSE RATES SHOULD BECOME QUITE STEEP IN CONJUNCTION WITH DIFFERENTIAL THERMAL ADVECTION AND DAYTIME HEATING. THIS WILL SUPPORT MODERATE TO STRONG INSTABILITY BY LATE AFTERNOON...WITH MIXED LAYER CAPE PEAKING IN THE 2000 TO 4000 J/KG RANGE. DESTABILIZATION AND LARGE-SCALE FORCING ARE EXPECTED TO GENERATE SUBSTANTIAL VIGOROUS LATE AFTERNOON/EVENING THUNDERSTORMS...WITHIN A THERMODYNAMIC ENVIRONMENT FAVORABLE FOR DAMAGING DOWNBURSTS AND LARGE HAIL. BEFORE INSTABILITY WANES WITH LOSS OF DAYTIME HEATING ...ACTIVITY FROM PARTS OF CENTRAL/SOUTHERN OKLAHOMA INTO WEST CENTRAL TEXAS COULD BE AUGMENTED BY MODERATELY STRONG SHEAR...AS A SOUTHERLY LOW-LEVEL JET STRENGTHENS DURING THE EVENING BENEATH WESTERLY MID-LEVEL FLOW. ...UPPER MISSISSIPPI VALLEY/GREAT LAKES REGION... INSTABILITY IS MORE UNCERTAIN ACROSS THIS AREA DUE TO THE LIKELIHOOD OF WEAKER LAPSE RATES. COLDER MID-LEVEL AIR MASS IS PROGGED TO LAG TO THE WEST OF A PRE-FRONTAL LOW-LEVEL CONFLUENT BAND...WHICH IS EXPECTED TO BECOME THE FOCUS FOR THE PRIMARY THUNDERSTORM ACTIVITY FROM PARTS OF NORTHEAST IOWA/SOUTHWEST MINNESOTA THROUGH CENTRAL WISCONSIN/UPPER MICHIGAN LATE SATURDAY AFTERNOON AND EVENING. SURFACE HEATING IN THE VICINITY OF THIS FEATURE MAY ALSO BE RESTRICTED BY CONSIDERABLE CLOUD COVER. HOWEVER...MODERATELY STRONG /30-35+ KT/ SOUTHWESTERLY MEAN FLOW REGIME WILL ENHANCE STORM MOTIONS AND POTENTIAL FOR GUSTY WINDS...WHICH COULD BRIEFLY APPROACH OR EXCEED SEVERE LIMITS. ..KERR.. 06/16/2006  From swody2 at goshenarc.org Fri Jun 16 17:28:17 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 16 Jun 2006 13:28:17 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 161725 SWODY2 SPC AC 161724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT FRI JUN 16 2006 VALID 171200Z - 181200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL/SRN PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM FAR NRN IA/SERN MN TO UPPER PENINSULA OF MI... ...SYNOPSIS... STRONG WLY MID/UPPER LEVEL FLOW WILL CONTINUE TO PENETRATE FARTHER INLAND ACROSS THE NRN TIER OF STATES ON SATURDAY REACHING THE NRN PLAINS TO UPPER GREAT LAKES REGION. THIS WILL ALLOW STORM SYSTEMS TO BE MORE PROGRESSIVE ACROSS THE NRN STATES INTO SERN CANADA. ONE SHORT WAVE TROUGH...INITIALLY LOCATED OVER SRN MANITOBA SATURDAY MORNING...SHOULD WEAKEN AS UPSTREAM TROUGH NOW ENTERING NW WA/SW BRITISH COLUMBIA AMPLIFIES EWD ACROSS ND TO NRN MN/WRN ONTARIO. THE SRN EXTENT OF THE CURRENT WRN U.S. TROUGH IS EXPECTED TO MOVE EWD INTO THE CENTRAL/SRN PLAINS AND WEAKEN SATURDAY AS IT BECOMES DETACHED FROM STRONGER FLOW TO THE NORTH AND RESIDES BETWEEN HEIGHT RISES OVER THE SOUTHWEST AND ERN STATES. MEANWHILE...SHORT WAVE TROUGH...NOW LOCATED ALONG THE UPPER TX COAST...IS EXPECTED TO WEAKEN AS IT TRACKS NEWD THROUGH THE LOWER MS TO LOWER OH VALLEYS. SURFACE TROUGH WILL MOVE SLOWLY EWD ACROSS THE CENTRAL STATES AND SHOULD EXTEND FROM NRN MN SWWD THROUGH ERN NEB/CENTRAL KS TO W TX BY 18/00Z. ...CENTRAL/SRN PLAINS... CONSIDERABLE CONVECTIVE DEVELOPMENT IS EXPECTED ACROSS A BROAD AREA OF THE CENTRAL U.S. IN ASSOCIATION WITH THE LOWER MS VALLEY IMPULSE AND THE CENTRAL/SRN PLAINS UPPER TROUGH. THE MOST VIGOROUS THUNDERSTORM DEVELOPMENT AND SEVERE POTENTIAL SHOULD BE FOCUSED ACROSS PARTS OF OK AND TX ALONG LEE SURFACE TROUGH AND OUTFLOW BOUNDARIES LEFT OVER FROM DAY 1 CONVECTION. AT 12Z SATURDAY...ONE OR TWO CLUSTERS OF STORMS SHOULD BE ONGOING ACROSS PARTS OF NEB/KS INTO OK ASSOCIATED WITH WAA ALONG STRONG SSWLY LLJ. THIS ACTIVITY IS EXPECTED TO MOVE EWD ALLOWING FOR SURFACE HEATING IN ITS WAKE ALONG/E OF SURFACE TROUGH. LAPSE RATES SHOULD BECOME QUITE STEEP IN THIS ENVIRONMENT PRIMARILY FROM OK SWD INTO TX WHERE SURFACE HEATING BENEATH COLDER MID LEVEL TEMPERATURES WILL RESULT IN MODERATE INSTABILITY. MODERATE WNWLY MID LEVEL FLOW /40+ KT/ WILL CONTRIBUTE TO SUFFICIENT DEEP LAYER SHEAR FOR STORMS TO BECOME ORGANIZED WITH THERMODYNAMICS FAVORING HAIL AND STRONG DOWNBURSTS WINDS. STRENGTHENING SLY LLJ ACROSS SRN/CENTRAL TX IS EXPECTED TO SUPPORT A CONTINUED SEVERE THREAT WITH ACTIVITY ACROSS THESE PARTS OF TX SATURDAY NIGHT. ...UPPER MS VALLEY/WRN GREAT LAKES REGION... THUNDERSTORMS MAY BE ONGOING AT 12Z SATURDAY FROM NEB NEWD ALONG A PRE-FRONTAL TROUGH EXTENDING ACROSS SWRN MN TO NRN WI/WRN U.P. OF MI. SURFACE HEATING ALONG/S OF THIS PRE-FRONTAL BOUNDARY IS EXPECTED TO SUPPORT AT LEAST MODERATE INSTABILITY ACROSS PARTS OF SRN/ERN MN INTO NRN WI/WRN U.P. OF MI DESPITE WEAKER MID LEVEL LAPSE RATES. LARGE SCALE ASCENT AHEAD OF A WEAK MID LEVEL IMPULSE MOVING NEWD ACROSS THIS REGION SHOULD SUPPORT THUNDERSTORM DEVELOPMENT BY SATURDAY AFTERNOON ALONG THE PRE-FRONTAL TROUGH. MODERATE INSTABILITY COMBINED WITH 40-50 KT OF SWLY MID LEVEL FLOW WILL SUPPORT ORGANIZED STORMS WITH HAIL AND DAMAGING WINDS BEING THE PRIMARY THREATS WITH THE STRONGEST ACTIVITY. GIVEN THIS SCENARIO...HIGHER PROBABILITIES AND A SLIGHT SEVERE RISK HAVE BEEN ADDED TO THIS REGION. ..PETERS.. 06/16/2006  From swody2 at goshenarc.org Sat Jun 17 05:49:01 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 17 Jun 2006 01:49:01 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 170545 SWODY2 SPC AC 170544 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1244 AM CDT SAT JUN 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE STRONGER WESTERLIES WILL PERSIST IN A BELT EXTENDING OUT OF THE NORTHERN PACIFIC...THROUGH THE NORTHWESTERN AND NORTH CENTRAL U.S....INTO SOUTHEASTERN CANADA THROUGH THIS FORECAST PERIOD. A COUPLE OF WAVES EMBEDDED WITHIN THIS REGIME ARE PROGGED TO REMAIN PROGRESSIVE...ONE ADVANCING FROM THE NORTH CENTRAL CANADIAN/U.S. BORDER AREA INTO THE GREAT LAKES...ANOTHER ADVANCING INLAND ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. IN ADVANCE OF LATTER FEATURE...AN UPPER RIDGE IS FORECAST TO BUILD ACROSS THE SOUTHERN U.S./NORTHERN MEXICAN PLATEAU REGION INTO THE CENTRAL/SOUTHERN PLAINS BY LATE SUNDAY NIGHT. WITH A SHARP UPPER RIDGE REMAINING STRONG THROUGH MUCH OF THE PERIOD ACROSS THE EASTERN STATES...SHEARING OF AN UPPER TROUGH TO THE SOUTH OF THE STRONGER WESTERLIES WILL CONTINUE ACROSS EASTERN PORTIONS OF THE SOUTHERN PLAINS INTO THE LOWER HALF OF THE MISSISSIPPI VALLEY. ...EAST OF ROCKIES... CONSIDERABLE UNCERTAINTY EXISTS CONCERNING SEVERE POTENTIAL SUNDAY/SUNDAY NIGHT. IT WILL REMAIN VERY MOIST FROM THE WESTERN/ CENTRAL GULF STATES NORTHWARD AHEAD OF A PRE-FRONTAL CONFLUENCE INTO THE LOWER GREAT LAKES REGION. HOWEVER...FLOW FIELDS ARE PROGGED TO WEAKEN CONSIDERABLY ACROSS THE SOUTH CENTRAL STATES IN RESPONSE TO EVOLVING UPPER PATTERN. AND...WHERE STRONG LOW/MID-LEVEL FLOW FIELDS PERSIST AHEAD OF NORTH CENTRAL U.S. UPPER TROUGH...WEAK LAPSE RATES WILL TEND TO MINIMIZE DESTABILIZATION. THIS WILL FURTHER BE LIMITED BY EXTENSIVE CLOUD COVER ASSOCIATED WITH A COUPLE OF DAYS OF WIDESPREAD CONVECTIVE DEVELOPMENT. STABILIZING INFLUENCE OF SURFACE COLD POOLS GENERATED BY THIS CONVECTION IS ALSO UNCERTAIN. IN WAKE OF PRE-FRONTAL CONFLUENT ZONE...PROGGED TO SHIFT ACROSS THE OHIO VALLEY/LOWER GREAT LAKES REGION DURING THE DAY SUNDAY... DIFFERENTIAL THERMAL ADVECTION ALONG/JUST AHEAD OF COLD FRONT SEEMS TO OFFER BEST POTENTIAL/FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT. BY LATE AFTERNOON...THE FRONT IS EXPECTED TO CURVE FROM THE UPPER GREAT LAKES REGION THROUGH THE NORTH CENTRAL PLAINS. THOUGH MOISTURE WILL BE LIMITED NEAR THIS FEATURE ...SUFFICIENT DESTABILIZATION APPEARS LIKELY FOR AT LEAST SCATTERED THUNDERSTORMS. PERHAPS ENHANCED BY FAVORABLE SHEAR BENEATH SEASONABLY STRONG CYCLONIC MID-LEVEL FLOW...A FEW STORMS COULD PRODUCE HAIL/GUSTY WINDS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS. ACTIVITY MAY SPREAD SOUTHEASTWARD THROUGH LOWER GREAT LAKES AND PARTS OF THE MIDDLE MISSISSIPPI VALLEY BEFORE DIMINISHING SUNDAY EVENING. FARTHER SOUTH...POTENTIAL FOR SURFACE HEATING APPEARS MUCH BETTER FROM PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY...WHERE 70F SURFACE DEW POINTS SHOULD PERSIST. BENEATH LINGERING MID-LEVEL COOL POCKET...THIS COULD CONTRIBUTE TO A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/LOCALIZED SEVERE STORMS WITH HAIL/GUSTY WINDS. ...WEST OF ROCKIES... FORCING/SHEAR ASSOCIATED WITH A 40-50 KT MID-LEVEL JET STREAK IS EXPECTED TO ENHANCE CONVECTIVE POTENTIAL NEAR LOW/MID-LEVEL BAROCLINIC ZONE ACROSS PARTS OF EASTERN OREGON/CENTRAL AND SOUTHERN IDAHO LATE SUNDAY AFTERNOON/EVENING. MOISTURE WILL BE LIMITED...BUT LAPSE RATES WILL BECOME QUITE STEEP AND SUPPORTIVE OF AT LEAST WIDELY SCATTERED STORMS WITH POTENTIAL FOR MICROBURSTS. ..KERR.. 06/17/2006  From swody2 at goshenarc.org Sat Jun 17 17:34:06 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 17 Jun 2006 13:34:06 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 171728 SWODY2 SPC AC 171728 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 PM CDT SAT JUN 17 2006 VALID 181200Z - 191200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... STRONG WESTERLIES WILL PERSIST IN A BELT EXTENDING FROM THE NORTHWESTERN AND NORTH CENTRAL U.S. INTO SOUTHEASTERN CANADA THIS FORECAST PERIOD. A COUPLE OF WAVES EMBEDDED WITHIN THIS REGIME ARE PROGGED TO REMAIN PROGRESSIVE...ONE ADVANCING FROM THE NORTH CENTRAL U.S./CANADIAN BORDER AREA INTO THE GREAT LAKES REGION... AND A SECOND MOVING INLAND ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. IN ADVANCE OF THE LATTER FEATURE...AN UPPER RIDGE IS FORECAST TO BUILD EWD INTO THE CENTRAL/SRN PLAINS WITH HEIGHT RISES ALSO EXTENDING NWD THROUGH THE NRN HIGH PLAINS. SHEARING OF AN UPPER TROUGH TO THE SOUTH OF THE STRONGER WESTERLIES WILL CONTINUE ACROSS EASTERN PORTIONS OF THE SOUTHERN PLAINS INTO THE LOWER HALF OF THE MISSISSIPPI VALLEY...AS A SHARP UPPER RIDGE REMAINS STRONG ACROSS THE ERN STATES. ...GREAT LAKES REGION SWWD TO ERN NEB/NERN KS... AIR MASS IS PROGGED TO REMAIN VERY MOIST FROM THE WESTERN/CENTRAL GULF STATES NORTHWARD AHEAD OF A PRE-FRONTAL TROUGH INTO THE LOWER GREAT LAKES REGION. AN EXTENSIVE BAND OF SHOWERS/EMBEDDED THUNDERSTORMS SHOULD BE ONGOING AT 12Z SUNDAY ALONG THIS TROUGH FROM PARTS OF THE LOWER MS VALLEY NNEWD INTO WI/LOWER MI. DEEP LAYER ASCENT AHEAD OF SHEARING UPPER TROUGH/ALONG PRE-FRONTAL TROUGH WILL MAINTAIN THIS ACTIVITY EWD INTO THE LOWER TN/OH VALLEYS AND SRN GREAT LAKES REGION THROUGH THE PERIOD. DESPITE STRONGER WIND FIELDS AHEAD OF NORTH CENTRAL U.S. UPPER TROUGH... WEAK LAPSE RATES SHOULD PRECLUDE A SEVERE THREAT WITH THIS LEAD BAND OF CONVECTION. IN WAKE OF PRE-FRONTAL CONFLUENT ZONE...SURFACE HEATING JUST AHEAD OF A COLD FRONT SEEMS TO SUGGEST BEST POTENTIAL/FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT. THIS FRONT IS EXPECTED TO CURVE FROM THE UPPER GREAT LAKES REGION THROUGH THE NORTH CENTRAL PLAINS BY LATE SUNDAY AFTERNOON. ALTHOUGH MOISTURE WILL TEND TO BE LIMITED NEAR THIS BOUNDARY...SUFFICIENT DESTABILIZATION APPEARS LIKELY FOR AT LEAST SCATTERED THUNDERSTORMS. ENHANCED SHEAR BENEATH STRONG CYCLONIC MID LEVEL FLOW MAINLY OVER THE ERN EXTENT OF THE COLD FRONT /SRN WI TO ERN IA/ MAY ALLOW A FEW STORMS TO PRODUCE HAIL/ GUSTY WINDS APPROACHING OR BRIEFLY EXCEEDING SEVERE LIMITS. ACTIVITY SHOULD SPREAD SOUTHEASTWARD THROUGH LOWER GREAT LAKES AND PARTS OF THE MID MS VALLEY BEFORE DIMINISHING SUNDAY EVENING. FARTHER WEST...MODELS SUGGEST POTENTIAL FOR ELEVATED THUNDERSTORMS DEVELOPING SUNDAY EVENING ACROSS ERN NEB/WRN IA WITHIN INCREASING ZONE OF LOW LEVEL WAA ALONG NOSE OF STRENGTHENING SWLY LLJ. ELEVATED INSTABILITY AND EFFECTIVE BULK SHEAR SUGGEST POTENTIAL FOR A FEW STORMS TO PRODUCE HAIL...WITH ACTIVITY DEVELOPING SEWD INTO NERN KS/NRN MO SUNDAY NIGHT. ...LOWER MS VALLEY TO EAST TX... SURFACE HEATING WITHIN MOIST AIR MASS /SURFACE DEWPOINTS 70+ F/ FROM PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY AND BENEATH LINGERING MID-LEVEL COOL POCKET WILL RESULT IN FAVORABLE THERMODYNAMIC ENVIRONMENT FOR STRONG/LOCALIZED SEVERE STORMS. WEAKENING FLOW FIELDS SUGGEST THIS ACTIVITY SHOULD BE MORE PULSE-TYPE WITH HAIL/GUSTY WINDS THE PRIMARY THREATS. ...ERN ORE/CENTRAL-SRN ID/SW MT... FORCING/SHEAR ASSOCIATED WITH A 40-50 KT MID-LEVEL JET STREAK IS EXPECTED TO ENHANCE CONVECTIVE POTENTIAL NEAR LOW/MID-LEVEL BAROCLINIC ZONE ACROSS PARTS OF ERN ORE/CENTRAL AND SRN ID LATE SUNDAY AFTERNOON/EVENING. MOISTURE WILL BE LIMITED...BUT LAPSE RATES WILL BECOME QUITE STEEP AND SUPPORTIVE OF AT LEAST WIDELY SCATTERED STORMS WITH POTENTIAL FOR MICROBURSTS. ..PETERS.. 06/17/2006  From swody2 at goshenarc.org Sun Jun 18 05:59:11 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 18 Jun 2006 01:59:11 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 180556 SWODY2 SPC AC 180555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT SUN JUN 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS MON ACROSS PARTS OF THE NRN APPALACHIANS INTO NEW ENGLAND.... ...THERE IS A SLGT RISK OF SVR TSTMS LATE MON/MON NIGHT ACROSS PARTS OF THE NRN ROCKIES INTO THE NRN PLAINS AND PARTS OF THE MID MO VALLEY.... A HIGH LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST PERIOD ACROSS THE NORTHEAST PACIFIC/ALASKA AND NORTHWEST CANADA. AND...MODELS INDICATE THAT THE SOUTHERN BRANCH OF THE ASSOCIATED SPLIT FLOW WILL REMAIN LARGELY ZONAL...AND GENERALLY NEAR OR JUST SOUTH THE CANADIAN/U.S. BORDER. A COUPLE OF BROADER SCALE TROUGHS...WITH ASSOCIATED SMALLER SCALE IMPULSES...ARE EMBEDDED WITHIN THIS REGIME...AND ARE PROGGED TO REMAIN PROGRESSIVE. IN TANDEM WITH TROUGHING IN THE NORTHERN STREAM...LEAD TROUGH IS FORECAST TO DEVELOP EAST SOUTHEAST OF THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES REGION MONDAY...THROUGH MUCH OF THE REMAINDER OF THE GREAT LAKES AND OHIO VALLEY BY EARLY TUESDAY. AS THIS OCCURS...AN UPSTREAM TROUGH IS FORECAST TO ADVANCE ACROSS THE NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES AND NORTHERN HIGH PLAINS...AHEAD OF A STRONG MID/UPPER JET STREAK NOSING ACROSS THE NORTHEAST PACIFIC TOWARD THE PACIFIC NORTHWEST COAST. ...GREAT LAKES/OHIO VALLEY INTO THE NORTHEAST... AHEAD OF MAIN UPPER TROUGH...CONFIDENCE IS GROWING THAT A SIGNIFICANT IMPULSE...FROM WEAKENING TROUGH NOW SOUTH OF MAIN BELT OF WESTERLIES...WILL ACCELERATE NORTHEASTWARD INTO THE UPPER OHIO VALLEY BY 12Z MONDAY...BEFORE CONTINUING INTO/THROUGH THE ST. LAWRENCE VALLEY/NORTHERN NEW ENGLAND. BELT OF STRONGER LOWER/MID- LEVEL FLOW /ON THE ORDER OF 30-40 KTS/ SEEMS LIKELY TO ACCOMPANY THIS FEATURE...ALONG WITH NARROW TONGUE OF VERY MOIST AIR.... INCLUDING SURFACE DEW POINTS AS HIGH AS 70F. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE WEAK...MODELS SUGGEST INFLUX OF MOISTURE AND DAYTIME HEATING WILL CONTRIBUTE TO MIXED LAYER CAPE OF 1000-2000 J/KG...FROM THE NORTH CENTRAL APPALACHIANS THROUGH THE HUDSON/ CHAMPLAIN VALLEY. ZONE OF ENHANCED MID-LEVEL FORCING IS EXPECTED TO BE SUFFICIENT FOR THE DEVELOPMENT OF A SOLIDIFYING CONVECTIVE LINE BY MONDAY AFTERNOON. AND...GIVEN POSSIBLE DESTABILIZATION AND FAVORABLE WIND FIELDS...POTENTIAL WILL EXIST FOR DAMAGING WINDS TO ACCOMPANY LOCALLY HEAVY RAINFALL WITH RELATIVELY FAST MOVING STORMS. ELSEWHERE...FORCING ON TAIL END OF MAIN...DIGGING UPPER TROUGH MAY SUPPORT ADDITIONAL SCATTERED VIGOROUS STORMS AHEAD OF COLD FRONT...THROUGH THE OHIO VALLEY LATE MONDAY AFTERNOON/EVENING. MOISTURE/LOW-LEVEL CONVERGENCE IN WAKE OF IMPULSE LIFTING THROUGH THE NORTHEAST IS UNCERTAIN...AND IT STILL APPEARS MOST PROBABLE THAT ANY SEVERE HAIL/WIND EVENTS WILL BE FAIRLY LOCALIZED AND LIMITED TO PERIOD NEAR/SHORTLY AFTER PEAK HEATING. ...NORTHERN ROCKIES THROUGH NORTHERN/CENTRAL PLAINS... MOISTURE RETURN IN DEVELOPING FAVORABLE UPSLOPE FLOW REGIME THROUGH THE HIGH PLAINS STILL APPEARS LIKELY TO BE SOMEWHAT MARGINAL FOR VIGOROUS CONVECTIVE DEVELOPMENT. HOWEVER...LAPSE RATES ARE EXPECTED TO BECOME STEEP AND SUPPORTIVE OF SEVERE HAIL/WIND...AS FORCING ASSOCIATED WITH OROGRAPHY AND APPROACHING TROUGH GENERATE DEEP CONVECTION. INITIATION IS EXPECTED BY LATE MONDAY AFTERNOON ACROSS THE MOUNTAINS OF SOUTHWEST MONTANA AND WYOMING...BEFORE SPREADING THROUGH SOUTHERN MONTANA AND NORTHEASTERN WYOMING...NEAR 40-50 KT MID-LEVEL JET STREAK...MONDAY EVENING. STRONG MID-LEVEL WARMING SOUTHEAST OF UPPER TROUGH...THROUGH MUCH OF THE NORTH CENTRAL PLAINS...WILL PROVIDE STRONG CAPPING. HOWEVER...EVENTUALLY...LOW/MID-LEVEL WARM ADVECTION ON EDGE OF CAP WILL PROBABLY SUPPORT AN EVOLVING CONVECTIVE CLUSTER AS MID-LEVEL JET NOSES INTO THE NORTHERN PLAINS MONDAY NIGHT. THIS STILL APPEARS MOST LIKELY NEAR THE NORTH DAKOTA/SOUTH DAKOTA BORDER AREA...WHERE SIZABLE LOW/MID-LEVEL TEMPERATURE DEW POINT SPREADS WILL CONTRIBUTE TO POTENTIAL FOR DAMAGING WIND GUSTS...IN ADDITION TO LARGE HAIL...DESPITE PRESENCE OF DEEPENING RADIATIONAL INVERSION LAYER. OTHER STORMS...PRIMARILY WITH LARGE HAIL POTENTIAL...APPEAR POSSIBLE LATE MONDAY NIGHT AS LIFT STRENGTHENS ON EDGE OF STRONGER CAPPING EAST OF THE MID MISSOURI VALLEY. ..KERR.. 06/18/2006  From swody2 at goshenarc.org Mon Jun 19 01:16:00 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 18 Jun 2006 21:16:00 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 181737 SWODY2 SPC AC 181736 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1236 PM CDT SUN JUN 18 2006 VALID 191200Z - 201200Z ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY FROM THE OH VALLEY TO NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS MONDAY/MONDAY NIGHT ACROSS PARTS OF THE NRN ROCKIES INTO THE NRN PLAINS AND PARTS OF THE MID MO VALLEY... ...SYNOPSIS... AMPLIFIED NRN STREAM WILL REMAIN PROGRESSIVE THROUGH THE DAY 2 PERIOD...WHILE A SUB-TROPICAL RIDGE BUILDS EWD THROUGH THE PLAINS STATES. ONE LARGE SCALE TROUGH DEVELOPING SEWD ACROSS THE UPPER MS VALLEY AND ONTARIO DURING DAY 1 PERIOD WILL MOVE EWD THROUGH THE GREAT LAKES/OH VALLEY TO NERN STATES BY 12Z TUESDAY. UPSTREAM PACIFIC TROUGH IS PROGGED TO TRACK EWD ACROSS THE NRN INTERMOUNTAIN WEST REACHING THE WRN DAKOTAS LATE DAY 2. WEAKER IMPULSES...WITHIN SRN FRINGE OF STRONGER SWLY MID LEVEL FLOW EXPECTED TO EXTEND FROM THE GREAT BASIN TO NRN PLAINS...WILL TRACK OVER THE CENTRAL HIGH PLAINS BY LATE MONDAY AFTERNOON. ...GREAT LAKES/OH VALLEY INTO THE NORTHEAST... UPPER TROUGH JUST SOUTH OF MAIN BELT OF WESTERLIES IS PROGGED TO WEAKEN AS IT SPREADS E TOWARD THE ERN SEABOARD MONDAY. HOWEVER... STRONGER IMPULSE...WITHIN NRN EXTENT OF THIS TROUGH AND CURRENTLY LOCATED OVER THE MID MS VALLEY...IS EXPECTED TO ACCELERATE NEWD FROM THE UPPER OH VALLEY TO NRN NEW ENGLAND/ST LAWRENCE VALLEY. 30-40 KT SWLY LOW-MID LEVEL FLOW WILL LIKELY ACCOMPANY THIS FEATURE ACROSS THE NERN STATES. SURFACE FRONT ASSOCIATED WITH LEAD TROUGH WILL SPREAD EWD ACROSS NY/CENTRAL-SRN APPALACHIANS THROUGH MONDAY AFTERNOON REACHING VT TO ERN PA/MD AND CENTRAL VA BY 20/00Z. A BAND OF SHOWERS/EMBEDDED THUNDERSTORMS MAY BE ONGOING ACROSS THE LOWER GREAT LAKES/UPPER OH VALLEY TO ERN TN AT 12Z MONDAY ALONG THE FRONT. SURFACE HEATING DOWNSTREAM OF THIS ACTIVITY IS EXPECTED TO RESULT IN MODERATE INSTABILITY NEWD FROM CENTRAL PA BY EARLY MONDAY AFTERNOON. THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE/INTENSITY AS THE FRONT MOVES EWD INTO THE GREATER INSTABILITY WITH LINEAR FORCING SUGGESTING A SQUALL LINE WILL BE POSSIBLE WITH DAMAGING WINDS AND HAIL THE PRIMARY THREATS. SEVERE THREAT SHOULD SPREAD ENE INTO WRN/NRN NEW ENGLAND BEFORE WEAKENING MONDAY NIGHT WITH A DECREASE IN CONVECTIVE INSTABILITY. FARTHER WEST...SURFACE HEATING IS EXPECTED IN THE WAKE OF MORNING ACTIVITY ACROSS THE UPPER OH VALLEY AND ALONG/E OF A SECOND SURFACE FRONT ASSOCIATED WITH GREAT LAKES UPPER TROUGH. THIS FRONT SHOULD EXTEND FROM LOWER MI TO CENTRAL IL BY EARLY MONDAY AFTERNOON. A MID LEVEL IMPULSE TRACKING THROUGH BASE OF UPPER TROUGH WILL MOVE ACROSS OH VALLEY MONDAY AFTERNOON/EVENING. RESULTANT STEEPENING OF LAPSE RATES DUE TO SURFACE HEATING AND ADVECTION OF COLD MID LEVEL TEMPERATURES WITH IMPULSE WILL SUPPORT MODERATE INSTABILITY ACROSS THE OH VALLEY. ASCENT AHEAD OF IMPULSE WILL SUPPORT THUNDERSTORMS ALONG SECONDARY FRONT MONDAY AFTERNOON WITH ACTIVITY SPREADING EWD THROUGH THE OH VALLEY... REACHING SWRN NY/WRN PA AND WV MONDAY EVENING. 50 KT MID LEVEL JET ACCOMPANYING IMPULSE WILL RESULT IN SUFFICIENT DEEP LAYER SHEAR FOR STORM ORGANIZATION WITH DAMAGING WINDS/HAIL THE PRIMARY THREATS. ...NRN ROCKIES THROUGH NRN/CENTRAL PLAINS.... MOISTURE RETURN WITHIN UPSLOPE FLOW REGIME ALONG THE HIGH PLAINS IS EXPECTED TO BE MARGINAL WITH LOWER 60S SURFACE DEWPOINTS POTENTIALLY EXTENDING INTO WRN NEB/NWRN KS MONDAY AFTERNOON. DESPITE THIS LIMITING FACTOR...STEEPENING LAPSE RATES AND STRONG FORCING SPREADING EWD AHEAD OF THE APPROACHING PACIFIC UPPER TROUGH COMBINED WITH OROGRAPHIC ASCENT ARE EXPECTED TO GENERATE DEEP CONVECTION BY MID-LATE MONDAY AFTERNOON OVER SW MT/WRN WY. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THIS INITIAL ACTIVITY. WARM MID LEVEL TEMPERATURES TO THE S OF THE UPPER TROUGH AND WITHIN SUB-TROPICAL RIDGE ARE EXPECTED TO CAP THE PLAINS STATES INCLUDING ERN MT/WY THROUGH MUCH OF THE DAY. HOWEVER...LARGE DEWPOINT DEPRESSIONS WILL RESULT IN INVERTED-V THERMODYNAMIC PROFILES ALONG THE NRN HIGH PLAINS. THIS COMBINED WITH STRENGTHENING WLY MID LEVEL WINDS /50 KT/ SUGGEST THE SEVERE THREAT COULD TRANSITION INTO A GREATER DAMAGING WIND POTENTIAL AS THE PACIFIC FRONT SPREADS EWD THROUGH MT/NRN WY. FARTHER S ALONG THE LEE TROUGH...ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE INTO WRN NEB AS STRONG SURFACE HEATING WEAKENS THE CAP BY LATE MONDAY AFTERNOON. DAMAGING WINDS AND LARGE HAIL WILL BE POSSIBLE WITH THIS ACTIVITY. LOW/MID-LEVEL WARM ADVECTION ON EDGE OF CAP WILL PROBABLY SUPPORT AN EVOLVING CONVECTIVE CLUSTER ACROSS ND/SD AS MID-LEVEL JET NOSES INTO THE NORTHERN PLAINS MONDAY NIGHT. HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THIS OVERNIGHT COMPLEX. OTHER STORMS...PRIMARILY WITH LARGE HAIL POTENTIAL...STILL APPEAR POSSIBLE LATE MONDAY NIGHT AS LIFT STRENGTHENS ON EDGE OF STRONGER CAPPING EAST OF THE MID MO VALLEY. ..PETERS.. 06/18/2006  From swody2 at goshenarc.org Mon Jun 19 05:39:05 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 01:39:05 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190538 SWODY2 SPC AC 190537 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1237 AM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE/TUE NIGHT ACROSS PARTS OF THE N CNTRL PLAINS INTO THE UPPER GREAT LAKES REGION.... MODELS CONTINUE TO INDICATE LITTLE CHANGE TO THE LARGE-SCALE PATTERN THROUGH THIS FORECAST PERIOD AND BEYOND. A SPLIT FLOW REGIME WILL PERSIST IN THE HIGHER LATITUDES...WITH THE SOUTHERN BELT REMAINING GENERALLY ZONAL ALONG/OR JUST SOUTH OF THE CANADIAN/U.S. BORDER. WITHIN THIS STREAM...A SERIES OF BROADER SCALE TROUGHS ARE FORECAST TO REMAIN PROGRESSIVE TUESDAY. THIS INCLUDES ONE PROGGED TO SHIFT EAST OF THE LOWER GREAT LAKES INTO NORTH ATLANTIC COASTAL AREAS...AND ANOTHER PROGGED EASTWARD ALONG THE CENTRAL CANADIAN/U.S. BORDER. ...N CNTRL PLAINS THRU THE UPPER GREAT LAKES REGION... STRONG DESTABILIZATION STILL APPEARS LIKELY BY EARLY TUESDAY ACROSS THE NORTH CENTRAL PLAINS/MID MISSOURI VALLEY REGION...WHERE BOUNDARY LAYER IS FORECAST TO MOISTEN CONSIDERABLY...BENEATH CAPPING MID-LEVEL THERMAL RIDGE NOSING NORTHEASTWARD OUT OF THE CENTRAL/SOUTHERN ROCKIES. SURFACE DEW POINTS ARE EXPECTED TO CLIMB THROUGH THE LOWER/MID 60S AS MID-LEVEL LAPSE RATES STEEPEN. THIS WILL CONTRIBUTE TO STRONG CONDITIONAL AND CONVECTIVE INSTABILITY...WHICH SHOULD YIELD MIXED LAYER CAPE ON THE ORDER OF 2000 TO 4000 J/KG BY PEAK HEATING TUESDAY AFTERNOON. VIGOROUS CONVECTIVE DEVELOPMENT COULD BE ONGOING AT 12Z TUESDAY IN FAVORABLE LOW/MID-LEVEL WARM ADVECTION REGIME ON NORTHERN/EASTERN PERIPHERY OF STRONGER CAP...FROM PARTS OF THE DAKOTAS SOUTHEASTWARD INTO IOWA. THIS ACTIVITY IS EXPECTED TO DEVELOP EASTWARD AND WEAKEN THROUGH THE DAY. THE FOCUS FOR PRIMARY CONVECTIVE DEVELOPMENT DURING THE LATE AFTERNOON...THEN...IS EXPECTED TO BE FORCING EAST OF WEAK FRONTAL WAVE...FORMING ON THE SOUTHERN FRINGE OF THE STRONGER WESTERLIES. THIS APPEARS MOST LIKELY FROM PARTS OF EASTERN NEBRASKA INTO CENTRAL IOWA. MODELS STILL INDICATE SEASONABLY STRONG WIND FIELDS WILL ACCOMPANY UPPER TROUGH THROUGH THE MID MISSOURI VALLEY...WITH THE NOSE OF A 30-40 KT SOUTHERLY LOW-LEVEL JET FORECAST BENEATH 40-50 KT WESTERLY MID-LEVEL FLOW...NEAR/EAST OF SURFACE WAVE. GIVEN PRESENCE OF LARGE CAPE...AND THERMODYNAMIC PROFILES SUPPORTING POTENTIAL FOR STRONG EVAPORATIVE COOLING NEAR HEAVY PRECIPITATION CORES...CONDITIONS SEEM LIKELY TO FAVOR RAPID TRANSITION FROM SUPERCELLS TO AN EXPANDING SEVERE MESOSCALE CONVECTIVE SYSTEM... BENEATH RELATIVELY WEAK BUT DIVERGENT UPPER FLOW. STRONG DAMAGING WINDS AND LARGE HAIL ARE EXPECTED...AND A SIGNIFICANT COLD POOL COULD DEVELOP TUESDAY EVENING AS ACTIVITY SPREADS ACROSS THE CORN BELT INTO THE UPPER MISSISSIPPI VALLEY. THIS COULD REACH THE UPPER GREAT LAKES REGION WITH CONTINUING SEVERE POTENTIAL BY THE END OF THE FORECAST PERIOD. FARTHER TO THE SOUTH/WEST...MODELS ARE SUGGESTIVE THAT AN IMPULSE IN THE SUBTROPICAL STREAM COULD WEAKEN INHIBITION SUFFICIENTLY FOR INITIATION OF CONVECTION NEAR FRONT/PRE-FRONTAL TROUGH ACROSS EASTERN COLORADO INTO CENTRAL KANSAS BY EARLY TUESDAY EVENING. IF THIS OCCURS...ANOTHER CLUSTER OF STORMS PROBABLY WILL EVENTUALLY EVOLVE IN ENVIRONMENT FAVORABLE FOR DOWNBURSTS AND SOME HAIL. ...SOUTHERN MID ATLANTIC COASTAL AREAS INTO NEW ENGLAND... STRONGER LOW-LEVEL FLOW FIELDS ARE PROGGED TO LIFT AWAY FROM NORTH ATLANTIC COASTAL AREAS BY EARLY TUESDAY...WITH AN ASSOCIATED TONGUE OF HIGHER PRECIPITABLE WATER GENERALLY SHIFTING OFFSHORE. HOWEVER...LINGERING LOW-LEVEL MOISTURE MAY SUPPORT SUFFICIENT DESTABILIZATION WITH DAYTIME HEATING FOR LOCALIZED HAIL/WIND EVENTS IN SCATTERED AFTERNOON THUNDERSTORMS. ACTIVITY IS EXPECTED TO DEVELOP AHEAD OF MID-LEVEL TROUGH AXIS...NEAR SURFACE FRONT ADVANCING TOWARD COASTAL NEW ENGLAND AND THE LOWER HUDSON VALLEY...AND NEAR LEE SURFACE TROUGH ACROSS MIDDLE/NORTHERN ATLANTIC COASTAL AREAS. ..KERR.. 06/19/2006  From swody2 at goshenarc.org Mon Jun 19 17:43:04 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 13:43:04 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191739 SWODY2 SPC AC 191738 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 PM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY INTO CO... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NEW ENGLAND... ...MID MS VALLEY... NRN ROCKIES SHORTWAVE TROUGH WILL FLATTEN UPPER RIDGE FROM THE NRN/CNTRL PLAINS INTO THE MID MS VALLEY REGION TUESDAY. WLY FLOW IN ASSOCIATION WITH THIS FEATURE WILL MAINTAIN A STOUT CAP ACROSS THE CNTRL PLAINS MOST OF THE PERIOD. LATEST THINKING IS DAY1 CONVECTION ACROSS THE NRN HIGH PLAINS WILL PROGRESS INTO THE DAKOTAS EARLY IN THE PERIOD AIDED BY LOW LEVEL WARM ADVECTION THAT WILL BECOME FOCUSED OVER THE MID/UPPER MS VALLEY LATER IN THE DAY. ELEVATED CONVECTION SHOULD SPREAD/DEVELOP SEWD INTO PORTIONS OF MN/IA ALONG THE ERN EDGE OF THE STRONG PLAINS CAP. THIS ACTIVITY MAY GENERATE HAIL WHILE ROOTED ABOVE THE BOUNDARY LAYER...BUT WITHIN STEEP MID LEVEL LAPSE RATE PLUME. OF MORE CONCERN IS THE POTENTIAL FOR BOUNDARY LAYER THUNDERSTORM DEVELOPMENT LATER IN THE DAY AHEAD OF COLD FRONT. IT APPEARS STRONG LOW LEVEL HEATING WILL OCCUR ACROSS WRN IA/ERN NEB...WHICH WILL BE NECESSARY FOR THE REMOVAL OF INHIBITION...AND CONVECTION SHOULD EVOLVE BY LATE AFTERNOON WITHIN A POTENTIALLY VERY UNSTABLE AIRMASS. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUPERCELL STRUCTURES ARE LIKELY WITH VERY LARGE HAIL POSSIBLE. WITH TIME...STORM MERGERS MAY RESULT IN MCS EVOLUTION WHICH COULD LEAD TO A MORE ORGANIZED DAMAGING WIND THREAT AS ACTIVITY SPREADS SEWD TOWARD NRN IL DURING THE OVERNIGHT HOURS. ...ERN CO/KS... UPSLOPE FLOW IN THE WAKE OF SWD SAGGING FRONTAL BOUNDARY WILL ALLOW HIGHER RH BOUNDARY LAYER TO SPREAD WWD INTO NERN CO TUESDAY AFTERNOON. TAIL END OF PLAINS UPPER TROUGH WILL BRUSH THIS REGION ENHANCING LARGE SCALE ASCENT AND AIDING UPSLOPE COMPONENT INTO EAST SLOPES. THUNDERSTORMS WILL DEVELOP BY MID-LATE AFTERNOON AND SPREAD SEWD TOWARD WRN KS WITH MORE THAN ENOUGH SHEAR FOR SUPERCELLS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH COVERAGE/INTENSITY OF STORMS EXPECTED TO BE MODULATED BY THE DEGREE OF BOUNDARY LAYER MOISTURE THAT CAN RETURN TO THIS REGION BEFORE INITIATION. IF SUFFICIENT MOISTURE DOES RETURN...AN MCS COULD EASILY EVOLVE OVER THE CNTRL HIGH PLAINS TUESDAY NIGHT. ...NEW ENGLAND/MIDDLE ATLANTIC... TIMING OF UPPER TROUGH AND THE PROGRESSION OF ASSOCIATED LOW LEVEL WIND SHIFT WILL PLAY AN IMPORTANT ROLE IN DEEP CONVECTION ACROSS NEW ENGLAND DURING THE DAY2 PERIOD. LATEST NAM GUIDANCE SUGGEST LOW LEVEL CONFLUENCE ZONE WILL HAVE SHIFTED INTO CNTRL ME...STRETCHING SWWD INTO CNTRL MA BY 18Z..AND THIS IS SUPPORTED BY 12Z GFS. A NARROW AXIS OF MODEST INSTABILITY WILL EVOLVE ALONG THIS WIND SHIFT WHICH SHOULD SUPPORT ORGANIZED DEEP CONVECTIVE DEVELOPMENT BY MID DAY. RAPID BOUNDARY LAYER HEATING WILL STEEPEN LOW LEVEL LAPSE RATES AND FORECAST SHEAR PROFILES SUGGEST SUFFICIENT WLY FLOW TO ALLOW STORMS TO PROGRESS TOWARD COASTAL AREAS DURING THE AFTERNOON. LARGE HAIL/DAMAGING WINDS MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/19/2006  From swody2 at goshenarc.org Mon Jun 19 17:55:46 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 19 Jun 2006 13:55:46 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191755 SWODY2 SPC AC 191753 DAY 2 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1253 PM CDT MON JUN 19 2006 VALID 201200Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY INTO CO... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NEW ENGLAND... CORRECTED FOR THUNDER LINE IN THE SOUTHERN U.S. ...MID MS VALLEY... NRN ROCKIES SHORTWAVE TROUGH WILL FLATTEN UPPER RIDGE FROM THE NRN/CNTRL PLAINS INTO THE MID MS VALLEY REGION TUESDAY. WLY FLOW IN ASSOCIATION WITH THIS FEATURE WILL MAINTAIN A STOUT CAP ACROSS THE CNTRL PLAINS MOST OF THE PERIOD. LATEST THINKING IS DAY1 CONVECTION ACROSS THE NRN HIGH PLAINS WILL PROGRESS INTO THE DAKOTAS EARLY IN THE PERIOD AIDED BY LOW LEVEL WARM ADVECTION THAT WILL BECOME FOCUSED OVER THE MID/UPPER MS VALLEY LATER IN THE DAY. ELEVATED CONVECTION SHOULD SPREAD/DEVELOP SEWD INTO PORTIONS OF MN/IA ALONG THE ERN EDGE OF THE STRONG PLAINS CAP. THIS ACTIVITY MAY GENERATE HAIL WHILE ROOTED ABOVE THE BOUNDARY LAYER...BUT WITHIN STEEP MID LEVEL LAPSE RATE PLUME. OF MORE CONCERN IS THE POTENTIAL FOR BOUNDARY LAYER THUNDERSTORM DEVELOPMENT LATER IN THE DAY AHEAD OF COLD FRONT. IT APPEARS STRONG LOW LEVEL HEATING WILL OCCUR ACROSS WRN IA/ERN NEB...WHICH WILL BE NECESSARY FOR THE REMOVAL OF INHIBITION...AND CONVECTION SHOULD EVOLVE BY LATE AFTERNOON WITHIN A POTENTIALLY VERY UNSTABLE AIRMASS. FORECAST SOUNDINGS FOR THIS REGION SUGGEST SUPERCELL STRUCTURES ARE LIKELY WITH VERY LARGE HAIL POSSIBLE. WITH TIME...STORM MERGERS MAY RESULT IN MCS EVOLUTION WHICH COULD LEAD TO A MORE ORGANIZED DAMAGING WIND THREAT AS ACTIVITY SPREADS SEWD TOWARD NRN IL DURING THE OVERNIGHT HOURS. ...ERN CO/KS... UPSLOPE FLOW IN THE WAKE OF SWD SAGGING FRONTAL BOUNDARY WILL ALLOW HIGHER RH BOUNDARY LAYER TO SPREAD WWD INTO NERN CO TUESDAY AFTERNOON. TAIL END OF PLAINS UPPER TROUGH WILL BRUSH THIS REGION ENHANCING LARGE SCALE ASCENT AND AIDING UPSLOPE COMPONENT INTO EAST SLOPES. THUNDERSTORMS WILL DEVELOP BY MID-LATE AFTERNOON AND SPREAD SEWD TOWARD WRN KS WITH MORE THAN ENOUGH SHEAR FOR SUPERCELLS. LARGE HAIL SHOULD BE THE PRIMARY SEVERE THREAT WITH COVERAGE/INTENSITY OF STORMS EXPECTED TO BE MODULATED BY THE DEGREE OF BOUNDARY LAYER MOISTURE THAT CAN RETURN TO THIS REGION BEFORE INITIATION. IF SUFFICIENT MOISTURE DOES RETURN...AN MCS COULD EASILY EVOLVE OVER THE CNTRL HIGH PLAINS TUESDAY NIGHT. ...NEW ENGLAND/MIDDLE ATLANTIC... TIMING OF UPPER TROUGH AND THE PROGRESSION OF ASSOCIATED LOW LEVEL WIND SHIFT WILL PLAY AN IMPORTANT ROLE IN DEEP CONVECTION ACROSS NEW ENGLAND DURING THE DAY2 PERIOD. LATEST NAM GUIDANCE SUGGEST LOW LEVEL CONFLUENCE ZONE WILL HAVE SHIFTED INTO CNTRL ME...STRETCHING SWWD INTO CNTRL MA BY 18Z..AND THIS IS SUPPORTED BY 12Z GFS. A NARROW AXIS OF MODEST INSTABILITY WILL EVOLVE ALONG THIS WIND SHIFT WHICH SHOULD SUPPORT ORGANIZED DEEP CONVECTIVE DEVELOPMENT BY MID DAY. RAPID BOUNDARY LAYER HEATING WILL STEEPEN LOW LEVEL LAPSE RATES AND FORECAST SHEAR PROFILES SUGGEST SUFFICIENT WLY FLOW TO ALLOW STORMS TO PROGRESS TOWARD COASTAL AREAS DURING THE AFTERNOON. LARGE HAIL/DAMAGING WINDS MAY OCCUR WITH THIS ACTIVITY. ..DARROW.. 06/19/2006  From swody2 at goshenarc.org Tue Jun 20 17:32:07 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 20 Jun 2006 13:32:07 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201731 SWODY2 SPC AC 201730 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT TUE JUN 20 2006 VALID 211200Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF THE GREAT LAKES/OH VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CENTRAL PLAINS... ...GREAT LAKES/OH VALLEY... MODELS ARE IN GENERAL AGREEMENT WITH SPEED/MOVEMENT OF SRN CANADA/NRN PLAINS TROUGH INTO THE GREAT LAKES REGION DURING THE DAY WEDNESDAY. THIS FEATURE WILL INDUCE HEIGHT FALLS ACROSS NRN WI/U.P. OF MI WHILE WLY FLOW...H5 SPEEDS ON THE ORDER OF 50-60KT...SHOULD INCREASE ALONG SRN FRINGES OF THIS FEATURE FROM SRN IA INTO SRN ONTARIO. THIS INCREASING WLY FLOW ALOFT...COMBINED WITH RECOVERING/MOISTENING BOUNDARY LAYER WILL ENHANCE THE PROSPECT FOR POTENTIALLY SIGNIFICANT THUNDERSTORM EVENT DAY2...WITH THE POSSIBILITY FOR LONG-LIVED ORGANIZED DAMAGING WINDS. LATEST THINKING IS SUSTAINED LOW LEVEL WARM ADVECTION WILL DRIVE EARLY MORNING CONVECTION ACROSS THE GREAT LAKES INTO THE OH VALLEY WITH BOUNDARY LAYER HEATING/DESTABILIZATION EXPECTED IN THE WAKE OF THIS ACTIVITY FROM LOWER MI...WSWWD INTO ERN IA BY EARLY AFTERNOON. IT APPEARS CONVECTION SHOULD DEVELOP/INTENSIFY BY MID DAY...POSSIBLY ALONG LEADING EDGE OF LATE DAY1 PLAINS CLUSTER...OVER PORTIONS OF IA/WI/NRN IL. THIS ACTIVITY SHOULD SEE UPSCALE GROWTH BENEATH DEEP WLY FLOW WITH SUSTAINED SWLY LLJ AIDING INFLOW. WITH TIME BOW TYPE STRUCTURES SHOULD EVOLVE WHICH WILL MOVE QUICKLY EWD INTO LOWER MI/NRN IND/OH BY LATE AFTERNOON. DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREAT...ESPECIALLY IF LONG-LIVED MCS CAN EVOLVE ACROSS THIS REGION. ...CENTRAL PLAINS... SEVERAL WEAK VORT MAXIMA EMBEDDED WITHIN WNWLY FLOW SHOULD APPROACH THE CNTRL ROCKIES WHICH SHOULD AID ELY LOW LEVEL COMPONENT ACROSS SERN WY/ERN CO. 700MB THERMAL GRADIENT HAS TIGHTENED ACROSS THIS REGION WITH MUCH COOLER TEMPERATURES SAGGING SWD TOWARD I-70. THIS COOLING ALOFT...COMBINED WITH UPSLOPE FLOW WILL UNDOUBTEDLY ENHANCE CONVECTIVE POTENTIAL BY MID-LATE AFTERNOON OVER NERN CO. SUPERCELLS SHOULD EVOLVE QUICKLY ONCE BOUNDARY LAYER WARMS THEN SPREAD SEWD ACROSS THE PLAINS TOWARD WRN KS. SUFFICIENT LOW LEVEL MOISTURE SHOULD BE IN PLACE ACROSS THE PLAINS BY STORM MATURATION FOR ISOLATED TORNADOES AND VERY LARGE HAIL. THIS REGION MAY NEED TO BE UPGRADED IN LATER OUTLOOKS...ESPECIALLY IF AN IDENTIFIABLE ORGANIZED SHORTWAVE TROUGH APPROACHES THIS REGION NEAR CONVECTIVE CLIMAX. ..DARROW.. 06/20/2006  From swody2 at goshenarc.org Wed Jun 21 05:33:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 21 Jun 2006 01:33:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210532 SWODY2 SPC AC 210531 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1231 AM CDT WED JUN 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM MUCH OF THE LWR GREAT LAKES/OHIO VALLEY REGION INTO THE SOUTH CENTRAL HIGH PLAINS.... WHILE THE SOUTHERN BRANCH OF HIGHER LATITUDE SPLIT FLOW PATTERN REMAINS GENERALLY ZONAL NEAR OR JUST SOUTH OF THE CANADIAN U.S. BORDER THROUGH THIS FORECAST PERIOD...MODELS CONTINUE TO INDICATE THAT SIGNIFICANT AMPLIFICATION WILL OCCUR IN THE NORTHERN STREAM ...ACROSS EASTERN CANADA. THIS SHOULD BE WELL UNDERWAY BY 12Z THURSDAY...WHEN A STRONG SHORT WAVE TROUGH IS FORECAST TO BE IN THE PROCESS OF DIGGING THROUGH SOUTHERN HUDSON BAY/NORTHERN ONTARIO. IN ADVANCE OF THE NORTHERN BRANCH SYSTEM...WHICH IS PROGGED TO TURN EASTWARD ACROSS ONTARIO INTO WESTERN QUEBEC THURSDAY/THURSDAY NIGHT....A SIGNIFICANT SOUTHERN BRANCH IMPULSE WILL CONTINUE LIFTING ACROSS QUEBEC THROUGH THE CANADIAN MARITIMES. AS THIS OCCURS...STRONGER SOUTHERLY LOW-LEVEL FLOW FIELDS WILL LIFT OUT OF THE NORTHEAST...BUT WESTERLY LOWER/MID TROPOSPHERIC FLOW WILL INTENSIFY AHEAD OF SIGNIFICANT SURFACE COLD FRONT ADVANCING THROUGH SOUTHEASTERN CANADA. THIS WILL GENERALLY OCCUR ACROSS THE LOWER GREAT LAKES INTO NORTHERN NEW ENGLAND...BUT THE SOUTHERN FRINGE OF MORE MODERATE WESTERLIES COULD EXTEND AS FAR SOUTH/WEST AS NORTHERN PARTS OF THE LOWER OHIO VALLEY THROUGH MUCH OF THE PERIOD. ACROSS THE WEST...ANOTHER MID-LEVEL JET STREAK/IMPULSE PROGRESSING ACROSS THE NORTHERN INTERMOUNTAIN REGION/ROCKIES APPEARS LIKELY TO BE INCONSEQUENTIAL TO SIGNIFICANT CONVECTIVE DEVELOPMENT DURING THIS PERIOD. BUT...AN IMPULSE IN THE WEAKER SUBTROPICAL STREAM TO THE SOUTH/EAST COULD ENHANCE CONVECTIVE POTENTIAL TO THE LEE OF THE SOUTH CENTRAL ROCKIES. ...MIDDLE MISSISSIPPI VALLEY EASTWARD THROUGH THE NORTHEAST... CONSIDERABLE UNCERTAINTIES EXIST. HOWEVER...IT APPEARS MOST PROBABLE THAT SUBSTANTIAL CONVECTIVE CLUSTER ASSOCIATED WITH INITIAL SOUTHERN BRANCH IMPULSE WILL WEAKEN AS IT PROGRESSES ACROSS THE HUDSON/CHAMPLAIN VALLEY THROUGH NORTHERN NEW ENGLAND EARLY THURSDAY. LOW-LEVEL MOISTURE IN ADVANCE OF SYSTEM ACROSS THIS REGION DOES NOT APPEAR LIKELY TO MAINTAIN VIGOROUS CONVECTION. BUT...MOISTENING/DAYTIME HEATING ACROSS THE NORTH CENTRAL APPALACHIANS...AND THE URBAN CORRIDOR FROM WASHINGTON D.C./BALTIMORE THROUGH NEW YORK CITY...COULD BE SUFFICIENT TO SUPPORT NEW STRONG STORMS ON THE LEADING EDGE OF CONVECTIVELY GENERATED COLD POOL...POSSIBLY BY EARLY AFTERNOON. IN THE WAKE OF WEAKENING CONVECTIVE SYSTEM...DOUBTS ARE INCREASING CONCERNING LIKELIHOOD OF SIGNIFICANT DESTABILIZATION FROM PARTS OF NORTHERN NEW YORK INTO NEW ENGLAND...AHEAD OF STRONG COLD FRONT WHICH COULD ADVANCE INTO THE LOWER GREAT LAKES/ST. LAWRENCE VALLEY AS EARLY AS LATE THURSDAY AFTERNOON. IT NOW APPEARS MOST LIKELY THAT COMPOSITE OUTFLOW BOUNDARY/PRE-FRONTAL CONFLUENT ZONE WILL BE THE FOCUS FOR PRIMARY CONVECTIVE DEVELOPMENT. THIS FEATURE IS EXPECTED TO STALL NEAR OR JUST SOUTH OF THE NEW YORK/PENNSYLVANIA BORDER...SOUTHWESTWARD THROUGH THE MIDDLE MISSISSIPPI VALLEY... BEFORE SLOWLY ADVANCING SOUTHWARD AS CONVECTION INCREASES LATE THURSDAY/THURSDAY NIGHT. ACTIVITY...PARTICULARLY ACROSS THE OHIO VALLEY/SOUTHERN GREAT LAKES...COULD BE ENHANCED BY A SHEARING SUBTROPICAL STREAM IMPULSE...GRADUALLY ACCELERATING OUT OF THE CENTRAL PLAINS. SEVERAL CLUSTERS OF STORMS APPEAR POSSIBLE...IN THERMODYNAMIC ENVIRONMENT WITH RELATIVELY STEEP LAPSE RATES AND MIXED LAYER CAPE IN EXCESS OF 2000 J/KG. MOMENTUM ON SOUTHERN FRINGE OF WESTERLIES IS EXPECTED TO SUPPORT STORM MOTIONS OF 30-35+ KT...WHICH SHOULD CONTRIBUTE TO DAMAGING WIND POTENTIAL...IN ADDITION TO LARGE HAIL. ...SOUTH CENTRAL PLAINS... MOIST UPSLOPE FLOW IN WAKE OF COMPOSITE OUTFLOW BOUNDARY ADVANCING SOUTHWARD TO THE LEE OF THE CENTRAL ROCKIES WILL CONTRIBUTE TO LARGE SCALE ASCENT/DESTABILIZATION IN STEEP LAPSE RATE ENVIRONMENT. THIS IS EXPECTED TO SUPPORT CONVECTIVE DEVELOPMENT OFF THE HIGHER TERRAIN LATE THURSDAY AFTERNOON. FLOW WILL BE RATHER WEAK...BUT VEERING WINDS WITH HEIGHT BENEATH NORTHWESTERLY MID-LEVEL FLOW MAY PROVIDE SUFFICIENT DEEP LAYER SHEAR FOR MID-LEVEL UPDRAFT ROTATION IN STRONGER STORMS. AIDED BY WEAK UPPER IMPULSE...ACTIVITY COULD CONSOLIDATE INTO ANOTHER MESOSCALE CONVECTIVE SYSTEM WITH ISOLATED DAMAGING WIND GUSTS...IN ADDITION TO HAIL...AS IT PROGRESSES INTO/THROUGH THE TEXAS PANHANDLE REGION THURSDAY NIGHT. ..KERR.. 06/21/2006  From swody2 at goshenarc.org Wed Jun 21 17:25:09 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 21 Jun 2006 13:25:09 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211724 SWODY2 SPC AC 211723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CDT WED JUN 21 2006 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/SRN PLAINS...NEWD TO PORTIONS OF WRN NEW ENGLAND... ...SYNOPSIS... A CONVECTIVELY-ACTIVE DAY APPEARS TO BE SHAPING UP FOR MUCH OF THE COUNTRY FROM THE CNTRL/SRN HIGH PLAINS...NEWD ALONG ADVANCING FRONTAL ZONE ACROSS THE OH VALLEY INTO PORTIONS OF NEW ENGLAND. THUNDERSTORMS...AND ULTIMATELY THEIR INTENSITY...WILL BE MODULATED BY AVAILABLE BUOYANCY WHICH WILL BE SIGNIFICANTLY IMPACTED BY DAY1 CONVECTIVE PROCESSES. MULTIPLE THUNDERSTORM COMPLEXES...MOST IN THE DECAYING STAGES...WILL BE ONGOING AT THE START OF THE PERIOD ALONG THE FRONTAL ZONE. THIS ACTIVITY WILL UNDOUBTEDLY FORCE OUTFLOW BOUNDARIES INTO THE WARM SECTOR WHICH WILL SERVE AS THE FOCUS FOR RENEWED DAYTIME DEVELOPMENT. LATEST THINKING IS THE GREATEST PROSPECT FOR BOUNDARY LAYER RECOVERY/HEATING WILL OCCUR ACROSS THE MID MS VALLEY AND OH VALLEY REGION...AS WELL AS PORTIONS OF THE SRN HIGH PLAINS. GIVEN THE 30-40KT 6KM SWLY FLOW ALOFT...ANY STORMS THAT DEVELOP ACROSS THE OH VALLEY SHOULD OBTAIN AT LEAST ORGANIZED MULTI-CELL CHARACTERISTICS. DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT WITH THIS ACTIVITY...AS WELL AS DOWNSTREAM CONVECTION ACROSS NY INTO PORTIONS OF WRN NEW ENGLAND. UPSTREAM...SFC FRONT SHOULD DRIVE SOUTH ACROSS THE HIGH PLAINS AS PRESSURES RISE OVER NEB...PARTLY ENHANCED BY OVERNIGHT CONVECTION. UPSLOPE FLOW COMPONENT INTO ERN CO...SWD INTO THE TX PANHANDLE WILL FORCE MOISTURE INTO A REGION THAT WILL SEE STRONG SUNSHINE AND RAPID DESTABILIZATION. ALTHOUGH MID-HIGH LEVEL NWLY FLOW WILL NOT BE THAT STRONG...DIRECTIONAL SHEAR WILL PROVE MORE THAN ADEQUATE FOR ORGANIZED UPDRAFTS...A FEW OF WHICH MAY ROTATE. WEAKENING CAP...BUT STEEP LAPSE RATES WILL SUPPORT LARGE HAIL. ALTHOUGH MODEST SEVERE PROBABILITIES WILL BE MAINTAINED FOR THIS OUTLOOK DUE TO THE COMPLEXITIES OF DAY1 CONVECTION...LATER OUTLOOKS MAY BE ABLE TO DISCERN WITH MORE CERTAINTY REGIONS FOR POTENTIAL UPGRADES LATER TONIGHT. ..DARROW.. 06/21/2006  From swody2 at goshenarc.org Thu Jun 22 05:18:22 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 22 Jun 2006 01:18:22 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220518 SWODY2 SPC AC 220516 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1216 AM CDT THU JUN 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FRI/EARLY FRI EVE FROM PARTS OF SRN NEW ENGLAND AND THE NRN MID ATLC COAST THRU THE OHIO VLY AND OZARK PLATEAU.... ...THERE IS A SLGT RISK OF SVR TSTMS FRI/EARLY FRI EVE ACROSS PARTS OF THE N CNTRL PLAINS.... MODELS INDICATE THAT A VIGOROUS NORTHERN BRANCH SHORT WAVE TROUGH...DIGGING THROUGH ONTARIO/QUEBEC TODAY...WILL QUICKLY LIFT OUT OF QUEBEC THROUGH THE CANADIAN MARITIMES DURING THIS FORECAST PERIOD. AS THIS OCCURS...LINGERING BELT OF CYCLONIC MID-LEVEL FLOW ACROSS MUCH OF THE GREAT LAKES/OHIO VALLEY INTO THE NORTHEAST WILL GRADUALLY BEGIN TO WEAKEN. STRONGER WESTERLIES...IN GENERAL...WILL CONTINUE TO RETREAT NORTH OF THE CANADIAN/U.S. BORDER FRIDAY...AS AN UPPER RIDGE BUILDS ACROSS THE WESTERN STATES...INTO THE CANADIAN ROCKIES. HOWEVER...ONE MORE FAIRLY SIGNIFICANT SOUTHERN STREAM SHORT WAVE TROUGH IS FORECAST TO DIG AROUND NORTHEASTERN PERIPHERY OF RIDGE...ACROSS THE NORTHERN PLAINS. AND...MODELS SUGGEST THAT WEAK MID-LEVEL TROUGHING ALREADY PRESENT ACROSS THE CENTRAL PLAINS...ON THE SOUTHERN FRINGE OF THE WESTERLIES...WILL ACCELERATE EASTWARD TOWARD THE SOUTHERN APPALACHIANS. AS THIS OCCURS...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST STATES WILL WEAKEN...AND A NARROW BELT OF MODERATE MID-LEVEL FLOW MAY SHIFT EAST OF THE OHIO VALLEY THROUGH THE NORTHERN MID ATLANTIC STATES BY THE PEAK HEATING HOURS. ...SRN NEW ENGLAND/NRN MID ATLANTIC THRU OH VLY/OZARK PLATEAU... A FAIRLY SIGNIFICANT COLD FRONT ASSOCIATED WITH THE NORTHERN BRANCH TROUGH APPEARS LIKELY TO BE IN THE PROCESS OF ADVANCING SOUTH/EAST OF THE LOWER GREAT LAKES AND ST. LAWRENCE VALLEY BY 12Z FRIDAY. THIS FRONT MAY CONTINUE SOUTHWARD INTO/THROUGH THE NORTHERN MID ATLANTIC COAST AND MUCH OF THE OHIO VALLEY BY THE END OF THE FORECAST PERIOD...BEFORE BEGINNING TO WEAKEN. THE FRONT LIKELY WILL BE PRECEDED BY A WEAK CONFLUENT ZONE OR COMPOSITE OUTFLOW BOUNDARY...ASSOCIATED WITH EXTENSIVE CONVECTIVE DEVELOPMENT TODAY...WHICH IS EXPECTED TO ALREADY EXTEND ACROSS THE NORTHERN MID ATLANTIC COAST STATES AND OHIO VALLEY INTO THE OZARK PLATEAU BY 12Z FRIDAY. WITH PERHAPS THE EXCEPTION OF SOUTHERN NEW ENGLAND...THIS PRE-FRONTAL BOUNDARY IS EXPECTED TO BECOME THE PRIMARY FOCUS FOR NEW CONVECTIVE DEVELOPMENT LATE FRIDAY MORNING AND AFTERNOON. THOUGH CLOUD COVER COULD BE CONSIDERABLE...ENOUGH HEATING OF MOIST BOUNDARY LAYER WITH UPPER 60S+ SURFACE DEW POINTS IS EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE UP TO AROUND 2000 J/KG. AS INHIBITION WEAKENS... THUNDERSTORM ACTIVITY IS EXPECTED TO BECOME NUMEROUS IN WEAK TO MODERATELY SHEARED WESTERLY MEAN FLOW REGIME. HAIL WILL BE POSSIBLE IN STRONGER CELLS...AND 30 KT MID LEVEL FLOW MAY BE ENOUGH TO ENHANCE STORM MOTIONS AND DOWNBURST POTENTIAL. ACTIVITY ACROSS MOST AREAS WILL PROBABLY WEAKEN RELATIVELY QUICKLY FRIDAY EVENING WITH LOSS OF DAYTIME HEATING. ...ROCKIES INTO PLAINS... COMPOSITE OUTFLOW SLOWLY ADVANCING THROUGH THE SOUTH CENTRAL PLAINS...AND MOIST UPSLOPE FLOW IN THE LEE OF THE ROCKIES TO THE NORTH WILL SUPPORT SCATTERED THUNDERSTORM ACTIVITY FRIDAY AFTERNOON AND EVENING. VEERING WINDS WITH HEIGHT BENEATH WEAK NORTHWESTERLY FLOW MAY CONTRIBUTE TO SUFFICIENT SHEAR FOR MID-LEVEL UPDRAFT ROTATION ACROSS MUCH OF THE CENTRAL/NORTHERN HIGH PLAINS. COVERAGE OF THIS ACTIVITY MAY BECOME MOST CONCENTRATED DURING THE LATE AFTERNOON FROM SOUTHEAST MONTANA/EASTERN WYOMING INTO THE WESTERN DAKOTAS...ASSOCIATED WITH WARM ADVECTION REGIME DOWNSTREAM OF APPROACHING SHORT WAVE. THIS FORCING WILL SPREAD SOUTHEASTWARD FRIDAY EVENING...BUT DUE TO MARGINAL LOW-LEVEL MOISTURE AND LIKELIHOOD OF QUICK RADIATIONAL SURFACE COOLING...SEVERE THREAT PROBABLY WILL NOT LAST LONG AFTER DARK. ..KERR.. 06/22/2006  From swody2 at goshenarc.org Thu Jun 22 17:24:50 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 22 Jun 2006 13:24:50 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221724 SWODY2 SPC AC 221723 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CDT THU JUN 22 2006 VALID 231200Z - 241200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TN VALLEY TO SOUTHERN NEW ENGLAND... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS... ...TN VALLEY TO SRN NEW ENGLAND... ANOTHER VERY ACTIVE CONVECTIVE EVENT WILL OCCUR DURING THE DAY2 PERIOD WITH A SLIGHT SEWD DISPLACEMENT INTO THE TN VALLEY...STRETCHING INTO SRN NEW ENGLAND. MODELS ARE IN GENERAL AGREEMENT WITH EWD MOVEMENT OF LONGWAVE TROUGH AXIS INTO THE GREAT LAKES WHICH WILL FORCE A ZONE OF MODEST SWLY FLOW ALOFT FROM KY INTO ME. LARGE SCALE PROCESSES SUGGEST SYNOPTIC FRONTAL ZONE WILL SAG SEWD INTO THIS REGION...AUGMENTED BY CONVECTIVE OUTFLOW FROM THURSDAY NIGHT CONVECTION. IT APPEARS ONE OR MORE WEAKENING MCS/S WILL BE ONGOING AT THE BEGINNING OF THE PERIOD...THE MOST LIKELY REGION WILL BE SOMEWHERE BETWEEN SRN IL INTO SWRN OH. ADDITIONAL WEAKER ACTIVITY MAY BE SCATTERED ALONG/NORTH OF THE BOUNDARY INTO UPSTATE NY. RAPID BOUNDARY LAYER WARMING ACROSS THE WARM SECTOR...COMBINED WITH ROUGHLY 30-40KT 6KM FLOW ALOFT...WILL RESULT IN RAPID INTENSIFICATION/EXPANSION OF MULTI-CELL THUNDERSTORM CLUSTERS BY MID DAY FROM KY/TN...NEWD INTO SRN NEW ENGLAND. DAMAGING WINDS AND HAIL ARE THE MOST LIKELY SEVERE THREATS WITH THIS ACTIVITY. ...NORTHERN/CENTRAL PLAINS... 12Z MODELS ARE FAIRLY CONSISTENT WITH UPPER RIDGE FLATTENING OVER THE NRN ROCKIES AS SPEED MAX/SHORTWAVE TROUGH TURNS SEWD AND DIGS TOWARD THE CNTRL PLAINS LATE IN THE PERIOD. THIS FEATURE WILL ENHANCE LOW LEVEL WARM ADVECTION ACROSS THE CNTRL HIGH PLAINS AS SELY FLOW RESPONDS TO WEAK HEIGHT FALLS AND HEATING IN THE LEE OF THE MT/WY HIGH TERRAIN. VERY STEEP LAPSE RATES WILL DEVELOP BENEATH THERMAL TROUGH CREATING A FAVORABLE ENVIRONMENT FOR ORGANIZED DEEP CONVECTION. SCATTERED THUNDERSTORMS SHOULD DEVELOP NEAR THE BLACK HILLS BY LATE AFTERNOON WITH SEWD DEVELOPMENT/MOVEMENT EXPECTED TOWARD NCNTRL NEB AFTER DARK. OTHER ISOLATED SEVERE STORMS ARE POSSIBLE SWD INTO PORTIONS OF NERN CO...ALTHOUGH FORCING ACROSS THIS REGION WILL BE SOMEWHAT WEAKER. LARGE HAIL IS THE MOST LIKELY SEVERE THREAT WITH SUPERCELLS THAT EVOLVE ACROSS THIS REGION. ..DARROW.. 06/22/2006  From swody2 at goshenarc.org Fri Jun 23 05:52:03 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 23 Jun 2006 01:52:03 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 230551 SWODY2 SPC AC 230550 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1250 AM CDT FRI JUN 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND SRN HIGH PLAINS... ...SYNOPSIS... SLIGHT AMPLIFICATION OF LONG WAVE PATTERN IS FORECAST DURING THE DAY TWO PERIOD WITH PRIMARY LARGE-SCALE FEATURES BEING UPPER LOW OVER ERN CANADA AND UPPER HIGH OVER THE GREAT BASIN. WITHIN THIS BROADER PATTERN...SEVERAL WEAK IMPULSES CURRENTLY OVER WRN CANADA ARE FORECAST TO CONSOLIDATE INTO A MORE INTENSE...AMPLIFYING SHORT WAVE TROUGH WHICH WILL DIG SEWD FROM THE NRN PLAINS AND UPPER MS VALLEY INTO THE UPPER MIDWEST SATURDAY AND SATURDAY NIGHT. IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO UPPER MS VALLEY SHORT WAVE TROUGH WILL GENERALLY DEVELOP SEWD FROM CNTRL OR SRN MN INTO SRN WI OR NRN IL BY SATURDAY NIGHT WITH TRAILING COLD FRONT SHIFTING SWD THROUGH THE CNTRL INTO SRN PLAINS. IN THE E...FRONTAL SYSTEM WILL PUSH SEWD THROUGH THE SRN NEW ENGLAND AND THE MIDDLE ATLANTIC STATES...WITH SRN EXTENSION OF THIS BOUNDARY REMAINING MORE QUASI-STATIONARY OVER THE CNTRL/SRN APPALACHIANS OR ADJACENT PIEDMONT REGION. ...CNTRL/SRN HIGH PLAINS... ERN EXTENSION OF HIGH TERRAIN STEEP LAPSE RATES WILL REMAIN CO-LOCATED WITH WRN EDGE OF LOW-LEVEL MOIST AXIS WITH MLCAPES INCREASING TO 1000-1500 J/KG BY AFTERNOON OVER ERN CO/WRN KS INTO THE TX/OK PNHDLS. TSTMS WILL BECOME INCREASINGLY LIKELY BY MID/LATE AFTERNOON FROM SERN WY SWD TO THE RATON MESA OWING TO INCREASED LOW-LEVEL OROGRAPHIC FORCING AND PERHAPS SOME DEEPER ASCENT ASSOCIATED WITH A SERIES OF WEAK IMPULSES APPROACHING FROM THE NW. FORECAST SOUNDINGS INDICATE ELY/NELY LOW-LEVEL WINDS VEERING TO NWLY AT 20-30 KTS IN THE MID-LEVELS...RESULTING IN SUFFICIENT DEEP-LAYER SHEAR FOR ORGANIZED/ROTATING STORMS CAPABLE OF MAINLY LARGE HAIL AND ISOLATED DAMAGING WINDS. DIURNAL STORMS SHOULD GROW UPSCALE INTO ONE OR MORE MCS/S SATURDAY NIGHT WITH A WIND/HAIL THREAT DEVELOPING SEWD INTO WRN KS AND THE TX/OK PNHDLS. ...MN/IA/WI/IL... CLUSTERS OF TSTMS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD WITHIN ZONE OF DEEP-LAYER FORCING FOR ASCENT AHEAD OF INTENSIFYING SHORT WAVE TROUGH DIGGING SEWD. THOUGH SURFACE FRONT WILL REMAIN ON IMMEDIATE BACKSIDE OF ANTICYCLONE OVER THE CNTRL GREAT LAKES...RESIDUAL LOW-LEVEL MOISTURE AND EVAPOTRANSPIRATION SHOULD SUPPORT DEWPOINTS IN THE MID/UPPER 60S WITH MLCAPES OF 1000-1500 J/KG. WHILE ISOLATED SEVERE STORMS CAPABLE OF HIGH WINDS/HAIL WILL BE POSSIBLE NEAR SURFACE LOW AND ASSOCIATED FRONT...IT APPEARS THAT WEAK LAPSE RATES AND ONLY MODEST SHEAR /20-30 KTS THROUGH THE LOWEST 6 KM AGL/ WILL PRECLUDE A MORE ORGANIZED SEVERE WEATHER THREAT. ...MIDDLE ATLANTIC STATES INTO THE SRN APPALACHIANS... HERE TOO...TSTMS SHOULD BE FAIRLY WIDESPREAD SATURDAY INTO SATURDAY NIGHT ALONG SURFACE FRONT WITHIN MOIST /I.E. DEWPOINTS IN THE UPPER 60S TO MID 70S/ AND WEAKLY CAPPED ENVIRONMENT. TROPOSPHERIC WINDS WILL REMAIN RELATIVELY WEAK...THOUGH THE MODERATE INSTABILITY AND MOIST CONDITIONS MAY SUPPORT ISOLATED WET MICROBURST EVENTS. ..MEAD.. 06/23/2006  From swody2 at goshenarc.org Fri Jun 23 17:30:28 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 23 Jun 2006 13:30:28 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 231730 SWODY2 SPC AC 231729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CDT FRI JUN 23 2006 VALID 241200Z - 251200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH PLAINS... ...CENTRAL/SRN HIGH PLAINS... UPPER RIDGE WILL HOLD OVER THE GREAT BASIN THROUGH DAY2 ALLOWING SHORTWAVE TROUGH DROPPING INTO THE MID MS VALLEY TO STRENGTHEN NNWLY FLOW ACROSS THE PLAINS. THIS FLOW REGIME WILL CONTINUE TO GENERATE ORGANIZED CONVECTION WITHIN UPSLOPE PATTERN UNTIL BOUNDARY LAYER MOISTURE IS REDUCED ACROSS THE HIGH PLAINS. THUNDERSTORM COMPLEX WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD OVER PORTIONS OF NEB/NRN KS. HOWEVER...WEAK WARM ADVECTION SHOULD NOT SUSTAIN THIS ACTIVITY BEYOND MID MORNING WHILE PRESSURE RISES OVER THE CNTRL PLAINS FORCE NELY LOW LEVEL FLOW INTO ERN CO. IT APPEARS THIS WILL BE THE GENERATING REGION FOR RENEWED THUNDERSTORM DEVELOPMENT BY MID AFTERNOON WHERE MODEST DEEP NWLY SHEAR VECTORS SHOULD ALLOW CONVECTION TO ORGANIZE/INTENSIFY...THEN PROPAGATE SWD TOWARD THE OK/TX PANHANDLES AND NERN NM. LARGE HAIL SHOULD BE THE MAIN SEVERE THREAT WITH SUPERCELLS AND LARGER THUNDERSTORM CLUSTERS. ...SRN MN/IA/WI/NWRN IL... HEIGHT FALLS AHEAD OF SHORTWAVE TROUGH WILL AID ASCENT AND STEEPEN LAPSE RATES ACROSS THE UPPER MS VALLEY REGION SATURDAY. EVEN SO...LOW LEVEL CONVERGENCE WILL NOT BE PARTICULARLY FOCUSED OR STRONG ALONG WIND SHIFT THAT WILL ADVANCE INTO MN/IA DURING THE AFTERNOON HOURS. ADDITIONALLY...BOUNDARY LAYER MOISTURE HAS DRIED SOMEWHAT ACROSS THIS REGION WITH SFC DEW POINTS ONLY IN THE 40S/50S. IT APPEARS THUNDERSTORMS SHOULD DEVELOP ALONG NOSE OF STRONGEST HEATING ACROSS SRN MN/NRN IA. THESE STORMS WILL MOVE SEWD WITH A THREAT OF SOME ORGANIZATION...BUT LIMITED BY INSTABILITY AND MARGINAL DEEP LAYER SHEAR. HAIL AND GUSTY WINDS MAY ACCOMPANY THIS ACTIVITY BUT THREAT APPEARS TOO LOW TO WARRANT A SLIGHT RISK AT THIS TIME. ...GULF STATES TO SRN NEW ENGLAND... THUNDERSTORMS WILL DEVELOP WITHIN VERY MOIST PLUME FROM THE CENTRAL GULF STATES INTO SRN NEW ENGLAND. LARGE SCALE FLOW WILL DIMINISH ACROSS THIS REGION AS SHORTWAVE DIGS INTO THE MID MS VALLEY...AND UPPER LOW PROPAGATES WWD INTO FL. ASIDE FROM A FEW WET MICROBURSTS IT DOES NOT APPEAR ORGANIZED SEVERE THUNDERSTORMS WILL BE AN ISSUE FOR THIS REGION SATURDAY. ..DARROW.. 06/23/2006  From swody2 at goshenarc.org Mon Jun 26 17:36:21 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 26 Jun 2006 13:36:21 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 261735 SWODY2 SPC AC 261734 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1234 PM CDT MON JUN 26 2006 VALID 271200Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE-SCALE UPPER PATTERN IS EXPECTED TO REMAIN GENERALLY UNCHANGED THIS PERIOD...WITH BROAD CYCLONIC FLOW OVER THE ERN 2/3 OF THE COUNTRY AND A LARGE SCALE RIDGE OVER THE WRN STATES. SEVERAL SMALLER SCALE FEATURES WILL TRAVERSE THE ERN LONGWAVE TROUGH. A VORTICITY MAXIMUM NOW OVER THE WRN ATLANTIC BASIN EAST OF NRN FL IS EXPECTED TO LIFT NWD ACROSS THE CAROLINAS AND MID-ATLANTIC REGION ON TUE. THE SECOND DISTURBANCE...NOW DROPPING SWD INTO THE MID-MS VLY REGION...WILL EJECT RAPIDLY NEWD TUE WHILE WEAKENING. A THIRD IMPULSE WILL MOVE SLOWLY SEWD ACROSS MN INTO THE UPPER MS VLY REGION THROUGH EARLY WED. AT THE SFC...LOW ASSOCIATED WITH THE ATLANTIC COASTAL UPPER FEATURE SHOULD CONTINUE TO WEAKEN WITH TIME...THOUGH BROAD SELY LOW-LEVEL FLOW N AND E OF THIS FEATURE WILL CONTINUE TO ADVECT SEASONABLY MOIST ENVIRONMENT ACROSS THE MID-ATLANTIC REGION. FURTHER W...SFC TROUGH ASSOCIATED WITH OH VALLEY VORT MAX SHOULD PERSIST ACROSS THE OH VLY REGION. FINALLY...A COLD FRONT SHOULD CONTINUE MOVING SLOWLY SWD ACROSS THE NRN/CNTRL PLAINS AND SEWD ACROSS THE UPPER MIDWEST/UPPER GRTLKS REGION THROUGH THE PERIOD. ....ERN CAROLINAS NWD TO THE MID-ATLANTIC REGION... HIGH PWAT VALUES WILL BE MAINTAINED ACROSS A LARGE PART OF THE REGION THROUGH TUE. MINIMAL CINH AND LOCALIZED FRICTIONAL CONVERGENCE WILL MAINTAIN THE RISK FOR RATHER WIDESPREAD CONVECTION. THERE WILL BE A LOW PROBABILITY FOR A TORNADO OR DAMAGING WIND GUST...PARTICULARLY ALONG THE TRACK OF THE WEAKENING DISTURBANCE THAT WILL MOVE NWD THROUGH THE CAROLINAS INTO VA DURING PEAK HEATING. PARTS OF THIS REGION MAY NEED A SLGT RISK IN LATER OUTLOOKS...ONCE MAGNITUDE OF INSTABILITY CAN BE BETTER ASSESSED. ...UPPER GRTLKS/UPPER MIDWEST WWD ACROSS NEB... BANDS OF CONVECTION WILL LIKELY INTENSIFY DURING PEAK HEATING TUE ALONG/AHEAD OF THE APPROACHING COLD FRONT...THOUGH CONVERGENCE IS EXPECTED TO REMAIN RATHER WEAK. GIVEN APPROACH OF COLD TEMPERATURES ALOFT...LAPSE RATES WILL STEEPEN ATOP AT LEAST 50S SFC DEW POINTS. AS A RESULT...A FEW STRONGER TSTMS WILL BE LIKELY WITH ISOLD HAIL. RELATIVELY DRY SUB-CLOUD LAYER AND UNIDIRECTIONAL FLOW REGIME WILL BE FAVORABLE FOR GUSTY WINDS. WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED. ...PARTS OF THE OH VLY AND MIDWEST... SLIGHTLY STRONGER/SSWLY FLOW ALOFT IS FORECAST FROM TN/KY NWD ACROSS THE MID/UPPER OH VLY REGION AND INTO SRN ONTARIO/QUEBEC AHEAD OF THE WEAKENING DISTURBANCE EJECTING NEWD. BUT...THE LATEST NAM APPEARS TO BE TOO UNSTABLE ALONG/AHEAD OF THE INVERTED TROUGH/COLD FRONT. GIVEN THAT THE DISTURBANCE WILL BE WEAKENING...SLIGHTLY WARMING MID-TROPOSPHERE AND THE FACT THAT MASS CONVERGENCE SHOULD RE-LOCATE FARTHER WEST AHEAD OF THE UPPER MS VLY IMPULSE...THE THREAT FOR SUSTAINED SEVERE CONVECTION APPEARS LIMITED. DIURNAL TSTMS ARE EXPECTED TO DEVELOP...PARTICULARLY ACROSS NRN IND INTO LWR MI AND ISOLD TSTMS MAY PRODUCE HAIL OR DAMAGING WINDS. ..RACY.. 06/26/2006  From swody2 at goshenarc.org Wed Jun 28 06:12:54 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 28 Jun 2006 02:12:54 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280610 SWODY2 SPC AC 280609 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT WED JUN 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO/MID MS/TN VALLEYS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ND... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC REGION... ...SYNOPSIS... UPPER PATTERN ACROSS THE U.S. WILL CONTINUE TO FEATURE A WRN RIDGE AND ERN TROUGH...THOUGH SOME DEAMPLIFICATION OF THE FLOW FIELD SHOULD OCCUR THIS PERIOD. CORRESPONDINGLY...SURFACE PATTERN SHOULD REMAIN GENERALLY WEAK...THOUGH A COLD FRONT MOVING TOWARD THE ATLANTIC COAST...A SECOND BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS/MID MO VALLEY...AND A THIRD MOVING EWD ACROSS ND SHOULD EACH SUPPORT CONVECTIVE DEVELOPMENT AND AN ASSOCIATED/LIMITED SEVERE THREAT. ...LOWER MO/MID MS/TN VALLEYS... AFTERNOON STORMS ARE FORECAST TO DEVELOP INVOF WEAK BAROCLINIC ZONE FORECAST ACROSS THIS REGION...AS AIRMASS BECOMES MODERATELY UNSTABLE DURING THE AFTERNOON. CONVECTIVE DEVELOPMENT MAY BE AIDED BY WEAK SHORT-WAVE TROUGH FORECAST BY NUMERICAL GUIDANCE TO MOVE SEWD ACROSS THIS REGION WITHIN NWLY CYCLONIC FLOW ON THE REAR SIDE OF MAIN UPPER TROUGH. THOUGH CAP SHOULD BE STRONGER AND SHEAR WEAKER WITH WWD EXTENT INTO THE CENTRAL PLAINS...THREAT APPEARS SUFFICIENT FROM NWRN MO SEWD INTO MIDDLE TN TO WARRANT A SLIGHT RISK. ALONG WITH POTENTIAL FOR HAIL...ROUGHLY UNIDIRECTIONAL/NWLY FLOW WITH HEIGHT ALSO SUGGESTS SOME POTENTIAL FOR DAMAGING WINDS WITH SMALL-SCALE LINES/BOWS WHICH COULD DEVELOP. OVERNIGHT...LOW-LEVEL JET SHOULD SUPPORT AN INCREASE IN WARM ADVECTION -- AND SUBSEQUENT CONVECTIVE COVERAGE -- ACROSS THIS REGION...PERHAPS SUPPORTING A CONTINUED SEVERE THREAT INTO THE OVERNIGHT HOURS. ...ND... EWD-MOVING COLD FRONT -- STRETCHING FROM THE CANADIAN PRAIRIE PROVINCES SWD ACROSS ERN MT AT THE START OF THE PERIOD -- SHOULD SHIFT EWD WITH TIME THROUGH THE DAY -- AHEAD OF MID-LEVEL SHORT-WAVE TROUGH. THOUGH LARGE-SCALE RIDGE ACROSS THE PLAINS SHOULD SUPPRESS CONVECTIVE DEVELOPMENT FROM SD SWD...STORMS SHOULD DEVELOP ALONG FRONT BY LATE AFTERNOON ACROSS PARTS OF NRN AND WRN ND...WHERE 50O TO 1000 J/KG MEAN-LAYER CAPE IS ANTICIPATED. THOUGH DEEP-LAYER WIND FIELD WILL NOT BE PARTICULARLY STRONG...SLY FLOW AHEAD OF FRONT VEERING/INCREASING WITH HEIGHT TO AROUND 30 KT FROM THE NW AT MID LEVELS WILL RESULT IN SHEAR SUPPORTIVE OF MULTICELL/WEAK SUPERCELL STORMS. THUS...THREAT FOR LOCALLY STRONG/DAMAGING WINDS AND/OR HAIL WILL BE POSSIBLE WITH THE STRONGER STORMS ACROSS THIS REGION. ...MID-ATLANTIC REGION... MODELS CONTINUE TO HINT THAT AN AREA OF SUFFICIENT DESTABILIZATION AND AMPLE SHEAR MAY COEXIST DURING THE AFTERNOON ACROSS THE MID-ATLANTIC REGION...NEAR COLD FRONT/AHEAD OF STRONG MID-LEVEL SHORT-WAVE TROUGH APPROACHING THIS REGION DURING THE AFTERNOON. PRESUMING THAT MORE WIDESPREAD PRECIPITATION WITHIN WARM CONVEYOR BELT CAN SHIFT E OF THIS REGION RESULTING IN SUFFICIENT INSTABILITY...THREAT FOR LOCALLY-SEVERE STORMS WOULD EXIST. THEREFORE...WILL RE-INTRODUCE A SLIGHT RISK ACROSS THIS REGION...GIVEN APPARENT POTENTIAL FOR HAIL AND/OR LOCALLY-DAMAGING WINDS DURING THE AFTERNOON/EARLY EVENING. ...ERN ID/SRN MT/NWRN WY... SHORT-WAVE TROUGH IS FORECAST TO ROTATE NEWD ACROSS THIS REGION DURING THE AFTERNOON...WITHIN SOMEWHAT ENHANCED FLOW ALOFT BETWEEN RIDGE OVER THE ROCKIES AND TROUGH OVER WRN CANADA. THOUGH DEGREE OF MOISTURE/INSTABILITY REMAINS QUESTIONABLE ATTM...IT APPEARS THAT SUFFICIENT COMBINATION OF SHEAR AND INSTABILITY MAY DEVELOP BY AFTERNOON TO SUPPORT SOME THREAT FOR ISOLATED SEVERE STORMS. ...UPPER GREAT LAKES... COOL /-16 TO -18/ MID-LEVEL TEMPERATURES ARE FORECAST ACROSS THIS REGION WITHIN CIRCULATION OF LARGE-SCALE TROUGH. SCATTERED LOW-TOPPED/PRIMARILY DIURNAL THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON...AS AIRMASS BECOMES MARGINALLY UNSTABLE. THOUGH GENERAL LACK OF INSTABILITY/SHEAR SHOULD PRECLUDE APPRECIABLE SEVERE THREAT...A FEW STRONGER CELLS MAY PRODUCE SMALL HAIL -- POSSIBLY APPROACHING MARGINAL SEVERE CRITERIA. ..GOSS.. 06/28/2006  From swody2 at goshenarc.org Wed Jun 28 17:24:26 2006 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 28 Jun 2006 13:24:26 -0400 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281723 SWODY2 SPC AC 281722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1222 PM CDT WED JUN 28 2006 VALID 291200Z - 301200Z ...THERE IS A SLGT RISK OF SVR TSTMS THU ACROSS PARTS OF THE NRN MID ATLANTIC COAST STATES.... ...THERE IS A SLGT RISK OF SVR TSTMS THU NIGHT ACROSS PARTS OF THE MID MS VALLEY.... WESTERLIES WILL REMAIN WEAK BENEATH SUBTROPICAL RIDGE ACROSS MUCH OF THE WESTERN/SOUTHERN STATES THROUGH THIS FORECAST PERIOD. BUT ...WESTERN RIDGE MAY BEGIN TO WEAKEN SOME...AS A SUBTROPICAL IMPULSE MIGRATES AROUND ITS NORTHWESTERN/NORTHERN PERIPHERY... ACROSS THE NORTHERN INTERMOUNTAIN REGION AND NORTHERN ROCKIES. DOWNSTREAM...MODELS SUGGEST A SIGNIFICANT IMPULSE...EMBEDDED WITHIN PERSISTENT TROUGHING OVER THE GREAT LAKES/OHIO VALLEY...WILL ACCELERATE EASTWARD THROUGH MUCH OF THE NORTHEAST AND MID ATLANTIC REGION BY 12Z FRIDAY. THIS IS FORECAST TO OCCUR AS ANOTHER FAIRLY VIGOROUS SHORT WAVE TROUGH DIGS TO THE SOUTHWEST THROUGH SOUTH OF A CLOSED LOW OVER SOUTHERN HUDSON/JAMES BAY. ...EAST COAST... HIGH MOISTURE CONTENT AIR OF THE PAST SEVERAL DAYS IS EXPECTED TO SHIFT EAST OF ALL BUT THE FLORIDA PENINSULA BY EARLY THURSDAY...AS IMPULSE EMANATING FROM THE LOWER LATITUDES LIFTS NORTHEAST OF NEW ENGLAND LATER TODAY. HOWEVER...LINGERING MOISTURE IS EXPECTED TO BE SUFFICIENT FOR SCATTERED CONVECTIVE DEVELOPMENT THURSDAY... BENEATH MID-LEVEL COOL POCKET ASSOCIATED WITH APPROACHING UPPER TROUGH...FROM THE LOWER LAKES INTO THE NORTHEAST...AND AHEAD OF UPPER TROUGH AXIS ACROSS THE REMAINDER OF ATLANTIC COASTAL AREAS. BY THURSDAY AFTERNOON...MODELS SUGGEST STRONGEST FORCING FOR UPPER VERTICAL MOTION MAY BECOME JUXTAPOSED WITH STRONGEST DESTABILIZATION ACROSS PARTS OF THE NORTHERN MID ATLANTIC COAST STATES...WHERE ANY SEVERE THREAT APPEARS MOST LIKELY TO BECOME CONCENTRATED. MIXED LAYER CAPE LIKELY WILL EXCEED 1000 J/KG ACROSS THIS REGION...AND COULD APPROACH 2000 J/KG...WHICH WILL BE SUPPORTIVE OF VIGOROUS UPDRAFTS. THOUGH LOW-LEVEL FLOW WILL BECOME RATHER WEAK...30 TO 40+ KT SOUTHERLY MID-LEVEL FLOW AHEAD OF UPPER TROUGH AXIS WILL CONTRIBUTE TO A MODERATELY SHEARED REGIME WHICH COULD ENHANCE HAIL POTENTIAL IN STRONGEST STORMS. ...CENTRAL STATES... WEAK SURFACE FRONT/LOW-LEVEL BAROCLINIC ZONE IS EXPECTED TO STALL FROM PARTS OF THE TENNESSEE VALLEY THROUGH THE LOWER MISSOURI VALLEY...AND COULD BECOME FOCUS FOR WIDELY SCATTERED THUNDERSTORMS LATE THURSDAY AFTERNOON. LOW-LEVEL THERMAL RIDGE AXIS TO THE SOUTH OF BOUNDARY WILL CONTRIBUTE TO STEEP LAPSE RATES AND FAVORABLE THERMODYNAMIC ENVIRONMENT FOR HAIL/GUSTY WINDS IN STRONGER STORMS. HOWEVER...POTENTIAL FOR A MORE ORGANIZED OR CONCENTRATED SEVERE THREAT SEEMS LOW UNTIL AFTER DARK...WHEN NOCTURNAL STRENGTHENING OF LOW-LEVEL JET..TO THE NORTH OF LOWER MISSISSIPPI VALLEY LOW-LEVEL RIDGE...COULD SUPPORT A GROWING CLUSTER OF STORMS. MODELS SUGGEST THIS IS MOST PROBABLE TO THE COOL SIDE OF THE SURFACE FRONT...ACROSS PARTS OF SOUTHERN IOWA/ NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS BY LATE THURSDAY NIGHT. ...WESTERN STATES... STRONGEST FORCING ASSOCIATED WITH SUBTROPICAL IMPULSE APPEARS LIKELY TO SHIFT ACROSS IDAHO THROUGH THE NORTHERN ROCKIES DURING THE DAYTIME HOURS THURSDAY. UNCERTAINTY EXISTS CONCERNING EXTENT OF CLOUD COVER LINGERING FROM DAY 1 CONVECTION...AND ITS INFLUENCE ON MAGNITUDE OF DAYTIME HEATING. BUT...EVEN IF CAPE IS MINIMAL... LARGE LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL BE FAVORABLE FOR AT LEAST LOCALIZED DOWNBURSTS. ..KERR.. 06/28/2006