MD 1797 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SE IND...NRN KY...WRN AND CNTRL OH
MESOSCALE DISCUSSION 1797 NWS STORM PREDICTION CENTER NORMAN OK 0258 PM CDT TUE SEP 07 2010 AREAS AFFECTED...SE IND...NRN KY...WRN AND CNTRL OH CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 071958Z - 072100Z AN ISOLATED THREAT FOR STRONG GUSTY WINDS AND HAIL WILL LIKELY DEVELOP ACROSS THE UPPER OH VALLEY OVER THE NEXT FEW HOURS. ALTHOUGH A WW IS NOT ANTICIPATED...THE THREAT WILL CONTINUE TO BE MONITORED THIS AFTERNOON. THUNDERSTORMS ARE STARTING TO INITIATE ALONG AND AHEAD OF A COLD FRONT FROM THE LOUISVILLE AREA EXTENDING TO EAST OF INDIANAPOLIS AND TO NORTHWEST OF COLUMBUS. THE STORMS ARE LOCATED ALONG THE NERN EDGE OF MODERATE INSTABILITY WHERE OBJECTIVE ANALYSIS IS ESTIMATING MLCAPE VALUES IN THE 1000 TO 1500 J/KG RANGE. THE INSTABILITY ALONG WITH AN UNCAPPED AIRMASS SHOULD RESULT IN THE DEVELOPMENT OF SFC-BASED THUNDERSTORMS WITH STRONG UPDRAFTS. AT MID-LEVELS...A WELL-DEFINED 80 TO 90 KT MID-LEVEL JET IS LOCATED ACROSS THE GREAT LAKES REGION. THE SRN EDGE OF THIS FEATURE IS CREATING MODERATE DEEP LAYER SHEAR ACROSS THE MCD AREA WHICH SHOULD HELP STORM ORGANIZATION. AS STORMS INCREASE IN COVERAGE AND INTENSITY...A FEW OF THE STRONGER CELLS MAY CONTAIN STRONG GUSTY WINDS ESPECIALLY AS LOW-LEVEL LAPSE RATES BECOME STEEP LATE THIS AFTERNOON. HAIL WILL ALSO BE POSSIBLE WITH THE MORE INTENSE CORES. ..BROYLES.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PBZ...RLX...CLE...ILN...LMK...IWX...IND... LAT...LON 41178131 41608178 41658245 41308336 39958484 38838634 38298651 37938524 38738357 40508161 41178131 Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT TUE SEP 07 2010 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN/SERN TX... SEVERE PROBABILITIES FOR ISOLATED TORNADOES REMAIN OVER TX AT 20Z. HERMINE CONTINUES ITS NNWWD MOVEMENT AT ROUGHLY 15KT AND IS CENTERED OVER KENDALL COUNTY IN CNTRL TX...NW OF SAT AT 1930Z. LATEST LIGHTNING DATA SUGGEST THE DEEPEST/STRONGEST CONVECTION EXTENDS IN BANDS FROM THE NWRN GULF OF MEXICO...NWD INTO ERN TX BEFORE ARCING INTO THE DFW METROPLEX. GIVEN THAT MINIMAL HEATING IS EXPECTED INVOF THE ACTUAL LOW CENTER...WILL CONTINUE THE GREATEST RISK OF TORNADOES BENEATH THE STRONGER BANDS WITHIN THE ERN PERIPHERY. CONVECTION IS GRADUALLY INCREASING ACROSS CNTRL IND INTO SWRN OH WITHIN VEERED FLOW AHEAD OF SFC FRONT. THIS ACTIVITY IS EVOLVING WITHIN AN AXIS OF MODEST INSTABILITY AND SUFFICIENT VERTICAL SHEAR FOR ORGANIZED UPDRAFTS. WILL MAINTAIN 5% PROBS FOR STORMS CAPABLE OF PRODUCING ISOLATED SEVERE WIND GUSTS AND PERHAPS SOME HAIL. STEEP LOW LEVEL LAPSE RATES DUE TO STRONG SFC HEATING WILL CONTRIBUTE TO STORM INTENSITY AND WITH LOSS OF DAYTIME HEATING THIS ACTIVITY SHOULD DECREASE. OTHERWISE...ONLY MINOR CHANGES TO PREVIOUS OUTLOOK TO ADJUST FOR DIURNAL TENDENCIES AND FRONTAL POSITION. ..DARROW.. 09/07/2010 .PREV DISCUSSION... /ISSUED 1111 AM CDT TUE SEP 07 2010/ ...CENTRAL AND SE TX THROUGH THIS EVENING... TROPICAL STORM HERMINE MAINTAINS A WELL-DEFINED CIRCULATION TO THE SSE OF SAT AND IS MOVING LARGELY NWD AT ABOUT 15 KT. SHORT TERM MODEL FORECASTS INSIST ON A MORE NWWD MOTION TOWARD W/NW TX TONIGHT...WHILE EXTRAPOLATION SUGGESTS SW OK BY THE END OF THE PERIOD. SEVERAL OUTER CONVECTIVE BANDS WITH SUBSTANTIAL LIGHTNING AND SOME EMBEDDED WEAK SUPERCELL STRUCTURES PERSIST IN THE ERN QUADRANTS OF THE SYSTEM. AN INFLUX OF MID-UPPER 70S DEWPOINTS AND WEAK SURFACE HEATING IN CLOUD BREAKS...ALONG WITH A BELT OF ENHANCED LOW-LEVEL FLOW/SHEAR BETWEEN SAT AND HOU...WILL MAINTAIN A THREAT FOR SUPERCELLS WITH A COUPLE OF TORNADOES THROUGH THE AFTERNOON/EVENING. ...UPPER OH VALLEY/LOWER GREAT LAKES THIS AFTERNOON/EVENING... THE OCCLUDED LOW OVER NRN WI/WRN UPPER MI/LAKE SUPERIOR WILL MOVE EWD OVER SRN ONTARIO TO SWRN QUEBEC...WHILE AN ASSOCIATED COLD FRONT PROGRESSES SEWD ACROSS THE OH VALLEY THIS EVENING AND THE LOWER GREAT LAKES EARLY TONIGHT. LOW-LEVEL MOISTURE IS INITIALLY LIMITED IN THE PRE-FRONTAL WARM SECTOR WHERE STRONG SURFACE HEATING IS UNDERWAY FROM KY NEWD INTO OH...THOUGH SOME INCREASE IS EXPECTED THIS AFTERNOON AS THE NERN FRINGE OF THE TROPICAL MOISTURE PLUME IS DRAWN NEWD AHEAD OF THE FRONT. THE NET RESULT WILL BE A NARROW CORRIDOR OF WEAK INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES...COINCIDENT WITH THE SRN PORTION OF THE STRONGER LOW-MIDLEVEL FLOW. A BROKEN BAND OF THUNDERSTORMS SHOULD DEVELOP BY MID-LATE AFTERNOON OVER THE LOWER OH VALLEY AND SPREAD NEWD TOWARD THE LOWER GREAT LAKES THIS EVENING/EARLY TONIGHT. FORECAST HODOGRAPHS APPEAR FAVORABLE FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...BUT THE WEAK INSTABILITY STILL APPEARS TO BE A LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT. ...ERN NV/WRN UT THROUGH EARLY TONIGHT... A MIDLEVEL TROUGH CONTINUES TO DIG SEWD OVER THE PAC NW COAST. DOWNSTREAM FROM THIS WAVE...THE NRN PORTIONS OF THE SUBTROPICAL MOISTURE PLUME WILL SPREAD NWD FROM AZ ACROSS ERN NV AND UT. SOME INCREASE IN SWLY MIDLEVEL FLOW AND STEEP LAPSE RATES WITH STRONG SURFACE HEATING ON THE FRINGES OF THE MOISTURE SURGE COULD SUPPORT A FEW STORMS WITH GUSTY OUTFLOW WINDS THIS AFTERNOON/EVENING FROM ERN NV INTO NW UT. HOWEVER...THE SEVERE STORM THREAT APPEARS TOO MARGINAL TO INTRODUCE ANY DAMAGING WIND PROBABILITIES AT THIS TIME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT TUE SEP 07 2010 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN/SERN TX... SEVERE PROBABILITIES FOR ISOLATED TORNADOES REMAIN OVER TX AT 20Z. HERMINE CONTINUES ITS NNWWD MOVEMENT AT ROUGHLY 15KT AND IS CENTERED OVER KENDALL COUNTY IN CNTRL TX...NW OF SAT AT 1930Z. LATEST LIGHTNING DATA SUGGEST THE DEEPEST/STRONGEST CONVECTION EXTENDS IN BANDS FROM THE NWRN GULF OF MEXICO...NWD INTO ERN TX BEFORE ARCING INTO THE DFW METROPLEX. GIVEN THAT MINIMAL HEATING IS EXPECTED INVOF THE ACTUAL LOW CENTER...WILL CONTINUE THE GREATEST RISK OF TORNADOES BENEATH THE STRONGER BANDS WITHIN THE ERN PERIPHERY. CONVECTION IS GRADUALLY INCREASING ACROSS CNTRL IND INTO SWRN OH WITHIN VEERED FLOW AHEAD OF SFC FRONT. THIS ACTIVITY IS EVOLVING WITHIN AN AXIS OF MODEST INSTABILITY AND SUFFICIENT VERTICAL SHEAR FOR ORGANIZED UPDRAFTS. WILL MAINTAIN 5% PROBS FOR STORMS CAPABLE OF PRODUCING ISOLATED SEVERE WIND GUSTS AND PERHAPS SOME HAIL. STEEP LOW LEVEL LAPSE RATES DUE TO STRONG SFC HEATING WILL CONTRIBUTE TO STORM INTENSITY AND WITH LOSS OF DAYTIME HEATING THIS ACTIVITY SHOULD DECREASE. OTHERWISE...ONLY MINOR CHANGES TO PREVIOUS OUTLOOK TO ADJUST FOR DIURNAL TENDENCIES AND FRONTAL POSITION. ..DARROW.. 09/07/2010 .PREV DISCUSSION... /ISSUED 1111 AM CDT TUE SEP 07 2010/ ...CENTRAL AND SE TX THROUGH THIS EVENING... TROPICAL STORM HERMINE MAINTAINS A WELL-DEFINED CIRCULATION TO THE SSE OF SAT AND IS MOVING LARGELY NWD AT ABOUT 15 KT. SHORT TERM MODEL FORECASTS INSIST ON A MORE NWWD MOTION TOWARD W/NW TX TONIGHT...WHILE EXTRAPOLATION SUGGESTS SW OK BY THE END OF THE PERIOD. SEVERAL OUTER CONVECTIVE BANDS WITH SUBSTANTIAL LIGHTNING AND SOME EMBEDDED WEAK SUPERCELL STRUCTURES PERSIST IN THE ERN QUADRANTS OF THE SYSTEM. AN INFLUX OF MID-UPPER 70S DEWPOINTS AND WEAK SURFACE HEATING IN CLOUD BREAKS...ALONG WITH A BELT OF ENHANCED LOW-LEVEL FLOW/SHEAR BETWEEN SAT AND HOU...WILL MAINTAIN A THREAT FOR SUPERCELLS WITH A COUPLE OF TORNADOES THROUGH THE AFTERNOON/EVENING. ...UPPER OH VALLEY/LOWER GREAT LAKES THIS AFTERNOON/EVENING... THE OCCLUDED LOW OVER NRN WI/WRN UPPER MI/LAKE SUPERIOR WILL MOVE EWD OVER SRN ONTARIO TO SWRN QUEBEC...WHILE AN ASSOCIATED COLD FRONT PROGRESSES SEWD ACROSS THE OH VALLEY THIS EVENING AND THE LOWER GREAT LAKES EARLY TONIGHT. LOW-LEVEL MOISTURE IS INITIALLY LIMITED IN THE PRE-FRONTAL WARM SECTOR WHERE STRONG SURFACE HEATING IS UNDERWAY FROM KY NEWD INTO OH...THOUGH SOME INCREASE IS EXPECTED THIS AFTERNOON AS THE NERN FRINGE OF THE TROPICAL MOISTURE PLUME IS DRAWN NEWD AHEAD OF THE FRONT. THE NET RESULT WILL BE A NARROW CORRIDOR OF WEAK INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES...COINCIDENT WITH THE SRN PORTION OF THE STRONGER LOW-MIDLEVEL FLOW. A BROKEN BAND OF THUNDERSTORMS SHOULD DEVELOP BY MID-LATE AFTERNOON OVER THE LOWER OH VALLEY AND SPREAD NEWD TOWARD THE LOWER GREAT LAKES THIS EVENING/EARLY TONIGHT. FORECAST HODOGRAPHS APPEAR FAVORABLE FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...BUT THE WEAK INSTABILITY STILL APPEARS TO BE A LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT. ...ERN NV/WRN UT THROUGH EARLY TONIGHT... A MIDLEVEL TROUGH CONTINUES TO DIG SEWD OVER THE PAC NW COAST. DOWNSTREAM FROM THIS WAVE...THE NRN PORTIONS OF THE SUBTROPICAL MOISTURE PLUME WILL SPREAD NWD FROM AZ ACROSS ERN NV AND UT. SOME INCREASE IN SWLY MIDLEVEL FLOW AND STEEP LAPSE RATES WITH STRONG SURFACE HEATING ON THE FRINGES OF THE MOISTURE SURGE COULD SUPPORT A FEW STORMS WITH GUSTY OUTFLOW WINDS THIS AFTERNOON/EVENING FROM ERN NV INTO NW UT. HOWEVER...THE SEVERE STORM THREAT APPEARS TOO MARGINAL TO INTRODUCE ANY DAMAGING WIND PROBABILITIES AT THIS TIME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT TUE SEP 07 2010 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN/SERN TX... SEVERE PROBABILITIES FOR ISOLATED TORNADOES REMAIN OVER TX AT 20Z. HERMINE CONTINUES ITS NNWWD MOVEMENT AT ROUGHLY 15KT AND IS CENTERED OVER KENDALL COUNTY IN CNTRL TX...NW OF SAT AT 1930Z. LATEST LIGHTNING DATA SUGGEST THE DEEPEST/STRONGEST CONVECTION EXTENDS IN BANDS FROM THE NWRN GULF OF MEXICO...NWD INTO ERN TX BEFORE ARCING INTO THE DFW METROPLEX. GIVEN THAT MINIMAL HEATING IS EXPECTED INVOF THE ACTUAL LOW CENTER...WILL CONTINUE THE GREATEST RISK OF TORNADOES BENEATH THE STRONGER BANDS WITHIN THE ERN PERIPHERY. CONVECTION IS GRADUALLY INCREASING ACROSS CNTRL IND INTO SWRN OH WITHIN VEERED FLOW AHEAD OF SFC FRONT. THIS ACTIVITY IS EVOLVING WITHIN AN AXIS OF MODEST INSTABILITY AND SUFFICIENT VERTICAL SHEAR FOR ORGANIZED UPDRAFTS. WILL MAINTAIN 5% PROBS FOR STORMS CAPABLE OF PRODUCING ISOLATED SEVERE WIND GUSTS AND PERHAPS SOME HAIL. STEEP LOW LEVEL LAPSE RATES DUE TO STRONG SFC HEATING WILL CONTRIBUTE TO STORM INTENSITY AND WITH LOSS OF DAYTIME HEATING THIS ACTIVITY SHOULD DECREASE. OTHERWISE...ONLY MINOR CHANGES TO PREVIOUS OUTLOOK TO ADJUST FOR DIURNAL TENDENCIES AND FRONTAL POSITION. ..DARROW.. 09/07/2010 .PREV DISCUSSION... /ISSUED 1111 AM CDT TUE SEP 07 2010/ ...CENTRAL AND SE TX THROUGH THIS EVENING... TROPICAL STORM HERMINE MAINTAINS A WELL-DEFINED CIRCULATION TO THE SSE OF SAT AND IS MOVING LARGELY NWD AT ABOUT 15 KT. SHORT TERM MODEL FORECASTS INSIST ON A MORE NWWD MOTION TOWARD W/NW TX TONIGHT...WHILE EXTRAPOLATION SUGGESTS SW OK BY THE END OF THE PERIOD. SEVERAL OUTER CONVECTIVE BANDS WITH SUBSTANTIAL LIGHTNING AND SOME EMBEDDED WEAK SUPERCELL STRUCTURES PERSIST IN THE ERN QUADRANTS OF THE SYSTEM. AN INFLUX OF MID-UPPER 70S DEWPOINTS AND WEAK SURFACE HEATING IN CLOUD BREAKS...ALONG WITH A BELT OF ENHANCED LOW-LEVEL FLOW/SHEAR BETWEEN SAT AND HOU...WILL MAINTAIN A THREAT FOR SUPERCELLS WITH A COUPLE OF TORNADOES THROUGH THE AFTERNOON/EVENING. ...UPPER OH VALLEY/LOWER GREAT LAKES THIS AFTERNOON/EVENING... THE OCCLUDED LOW OVER NRN WI/WRN UPPER MI/LAKE SUPERIOR WILL MOVE EWD OVER SRN ONTARIO TO SWRN QUEBEC...WHILE AN ASSOCIATED COLD FRONT PROGRESSES SEWD ACROSS THE OH VALLEY THIS EVENING AND THE LOWER GREAT LAKES EARLY TONIGHT. LOW-LEVEL MOISTURE IS INITIALLY LIMITED IN THE PRE-FRONTAL WARM SECTOR WHERE STRONG SURFACE HEATING IS UNDERWAY FROM KY NEWD INTO OH...THOUGH SOME INCREASE IS EXPECTED THIS AFTERNOON AS THE NERN FRINGE OF THE TROPICAL MOISTURE PLUME IS DRAWN NEWD AHEAD OF THE FRONT. THE NET RESULT WILL BE A NARROW CORRIDOR OF WEAK INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES...COINCIDENT WITH THE SRN PORTION OF THE STRONGER LOW-MIDLEVEL FLOW. A BROKEN BAND OF THUNDERSTORMS SHOULD DEVELOP BY MID-LATE AFTERNOON OVER THE LOWER OH VALLEY AND SPREAD NEWD TOWARD THE LOWER GREAT LAKES THIS EVENING/EARLY TONIGHT. FORECAST HODOGRAPHS APPEAR FAVORABLE FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...BUT THE WEAK INSTABILITY STILL APPEARS TO BE A LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT. ...ERN NV/WRN UT THROUGH EARLY TONIGHT... A MIDLEVEL TROUGH CONTINUES TO DIG SEWD OVER THE PAC NW COAST. DOWNSTREAM FROM THIS WAVE...THE NRN PORTIONS OF THE SUBTROPICAL MOISTURE PLUME WILL SPREAD NWD FROM AZ ACROSS ERN NV AND UT. SOME INCREASE IN SWLY MIDLEVEL FLOW AND STEEP LAPSE RATES WITH STRONG SURFACE HEATING ON THE FRINGES OF THE MOISTURE SURGE COULD SUPPORT A FEW STORMS WITH GUSTY OUTFLOW WINDS THIS AFTERNOON/EVENING FROM ERN NV INTO NW UT. HOWEVER...THE SEVERE STORM THREAT APPEARS TOO MARGINAL TO INTRODUCE ANY DAMAGING WIND PROBABILITIES AT THIS TIME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0241 PM CDT TUE SEP 07 2010 VALID 072000Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN/SERN TX... SEVERE PROBABILITIES FOR ISOLATED TORNADOES REMAIN OVER TX AT 20Z. HERMINE CONTINUES ITS NNWWD MOVEMENT AT ROUGHLY 15KT AND IS CENTERED OVER KENDALL COUNTY IN CNTRL TX...NW OF SAT AT 1930Z. LATEST LIGHTNING DATA SUGGEST THE DEEPEST/STRONGEST CONVECTION EXTENDS IN BANDS FROM THE NWRN GULF OF MEXICO...NWD INTO ERN TX BEFORE ARCING INTO THE DFW METROPLEX. GIVEN THAT MINIMAL HEATING IS EXPECTED INVOF THE ACTUAL LOW CENTER...WILL CONTINUE THE GREATEST RISK OF TORNADOES BENEATH THE STRONGER BANDS WITHIN THE ERN PERIPHERY. CONVECTION IS GRADUALLY INCREASING ACROSS CNTRL IND INTO SWRN OH WITHIN VEERED FLOW AHEAD OF SFC FRONT. THIS ACTIVITY IS EVOLVING WITHIN AN AXIS OF MODEST INSTABILITY AND SUFFICIENT VERTICAL SHEAR FOR ORGANIZED UPDRAFTS. WILL MAINTAIN 5% PROBS FOR STORMS CAPABLE OF PRODUCING ISOLATED SEVERE WIND GUSTS AND PERHAPS SOME HAIL. STEEP LOW LEVEL LAPSE RATES DUE TO STRONG SFC HEATING WILL CONTRIBUTE TO STORM INTENSITY AND WITH LOSS OF DAYTIME HEATING THIS ACTIVITY SHOULD DECREASE. OTHERWISE...ONLY MINOR CHANGES TO PREVIOUS OUTLOOK TO ADJUST FOR DIURNAL TENDENCIES AND FRONTAL POSITION. ..DARROW.. 09/07/2010 .PREV DISCUSSION... /ISSUED 1111 AM CDT TUE SEP 07 2010/ ...CENTRAL AND SE TX THROUGH THIS EVENING... TROPICAL STORM HERMINE MAINTAINS A WELL-DEFINED CIRCULATION TO THE SSE OF SAT AND IS MOVING LARGELY NWD AT ABOUT 15 KT. SHORT TERM MODEL FORECASTS INSIST ON A MORE NWWD MOTION TOWARD W/NW TX TONIGHT...WHILE EXTRAPOLATION SUGGESTS SW OK BY THE END OF THE PERIOD. SEVERAL OUTER CONVECTIVE BANDS WITH SUBSTANTIAL LIGHTNING AND SOME EMBEDDED WEAK SUPERCELL STRUCTURES PERSIST IN THE ERN QUADRANTS OF THE SYSTEM. AN INFLUX OF MID-UPPER 70S DEWPOINTS AND WEAK SURFACE HEATING IN CLOUD BREAKS...ALONG WITH A BELT OF ENHANCED LOW-LEVEL FLOW/SHEAR BETWEEN SAT AND HOU...WILL MAINTAIN A THREAT FOR SUPERCELLS WITH A COUPLE OF TORNADOES THROUGH THE AFTERNOON/EVENING. ...UPPER OH VALLEY/LOWER GREAT LAKES THIS AFTERNOON/EVENING... THE OCCLUDED LOW OVER NRN WI/WRN UPPER MI/LAKE SUPERIOR WILL MOVE EWD OVER SRN ONTARIO TO SWRN QUEBEC...WHILE AN ASSOCIATED COLD FRONT PROGRESSES SEWD ACROSS THE OH VALLEY THIS EVENING AND THE LOWER GREAT LAKES EARLY TONIGHT. LOW-LEVEL MOISTURE IS INITIALLY LIMITED IN THE PRE-FRONTAL WARM SECTOR WHERE STRONG SURFACE HEATING IS UNDERWAY FROM KY NEWD INTO OH...THOUGH SOME INCREASE IS EXPECTED THIS AFTERNOON AS THE NERN FRINGE OF THE TROPICAL MOISTURE PLUME IS DRAWN NEWD AHEAD OF THE FRONT. THE NET RESULT WILL BE A NARROW CORRIDOR OF WEAK INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES...COINCIDENT WITH THE SRN PORTION OF THE STRONGER LOW-MIDLEVEL FLOW. A BROKEN BAND OF THUNDERSTORMS SHOULD DEVELOP BY MID-LATE AFTERNOON OVER THE LOWER OH VALLEY AND SPREAD NEWD TOWARD THE LOWER GREAT LAKES THIS EVENING/EARLY TONIGHT. FORECAST HODOGRAPHS APPEAR FAVORABLE FOR ORGANIZED LINE SEGMENTS AND/OR SUPERCELLS...BUT THE WEAK INSTABILITY STILL APPEARS TO BE A LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT. ...ERN NV/WRN UT THROUGH EARLY TONIGHT... A MIDLEVEL TROUGH CONTINUES TO DIG SEWD OVER THE PAC NW COAST. DOWNSTREAM FROM THIS WAVE...THE NRN PORTIONS OF THE SUBTROPICAL MOISTURE PLUME WILL SPREAD NWD FROM AZ ACROSS ERN NV AND UT. SOME INCREASE IN SWLY MIDLEVEL FLOW AND STEEP LAPSE RATES WITH STRONG SURFACE HEATING ON THE FRINGES OF THE MOISTURE SURGE COULD SUPPORT A FEW STORMS WITH GUSTY OUTFLOW WINDS THIS AFTERNOON/EVENING FROM ERN NV INTO NW UT. HOWEVER...THE SEVERE STORM THREAT APPEARS TOO MARGINAL TO INTRODUCE ANY DAMAGING WIND PROBABILITIES AT THIS TIME. Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CDT TUE SEP 07 2010 VALID 091200Z - 151200Z AN UPPER LEVEL TROUGH IS FORECAST TO MOVE E-NEWD ACROSS THE GREAT BASIN ON THURSDAY/D3...AND WILL FOCUS A ZONE OF NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /RH VALUES AOB 15 PERCENT AND SUSTAINED SURFACE WIND SPEEDS OF 20-25 MPH/ FROM CNTRL WY S-SWWD INTO PORTIONS OF UT/WRN CO AND NRN AZ. THE TROUGH THEN EJECTS INTO THE GREAT PLAINS ON FRIDAY/D4. MODEL GUIDANCE INDICATES INCREASING POTENTIAL FOR MODERATELY STRONG DOWNSLOPE WINDS ALONG THE LEE OF THE FRONT RANGE OF THE CNTRL ROCKIES AND ADJACENT HIGH PLAINS...WHICH MAY LEAD TO RAPID DRYING AND CRITICAL FIRE WEATHER CONDITIONS AS THE TROUGH PASSES ACROSS THE REGION. THIS AREA WILL BE MONITORED CLOSELY FOR A POSSIBLE UPGRADE IN FUTURE OUTLOOKS. THE CNTRL CONUS TROUGH IS THEN FORECAST TO EJECT NEWD TOWARD THE UPR MS VALLEY REGION ON SATURDAY/D5...FOLLOWED BY A DECREASING POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DURING THE D6-8 PERIOD. ..GARNER.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CDT TUE SEP 07 2010 VALID 091200Z - 151200Z AN UPPER LEVEL TROUGH IS FORECAST TO MOVE E-NEWD ACROSS THE GREAT BASIN ON THURSDAY/D3...AND WILL FOCUS A ZONE OF NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /RH VALUES AOB 15 PERCENT AND SUSTAINED SURFACE WIND SPEEDS OF 20-25 MPH/ FROM CNTRL WY S-SWWD INTO PORTIONS OF UT/WRN CO AND NRN AZ. THE TROUGH THEN EJECTS INTO THE GREAT PLAINS ON FRIDAY/D4. MODEL GUIDANCE INDICATES INCREASING POTENTIAL FOR MODERATELY STRONG DOWNSLOPE WINDS ALONG THE LEE OF THE FRONT RANGE OF THE CNTRL ROCKIES AND ADJACENT HIGH PLAINS...WHICH MAY LEAD TO RAPID DRYING AND CRITICAL FIRE WEATHER CONDITIONS AS THE TROUGH PASSES ACROSS THE REGION. THIS AREA WILL BE MONITORED CLOSELY FOR A POSSIBLE UPGRADE IN FUTURE OUTLOOKS. THE CNTRL CONUS TROUGH IS THEN FORECAST TO EJECT NEWD TOWARD THE UPR MS VALLEY REGION ON SATURDAY/D5...FOLLOWED BY A DECREASING POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DURING THE D6-8 PERIOD. ..GARNER.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CDT TUE SEP 07 2010 VALID 091200Z - 151200Z AN UPPER LEVEL TROUGH IS FORECAST TO MOVE E-NEWD ACROSS THE GREAT BASIN ON THURSDAY/D3...AND WILL FOCUS A ZONE OF NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /RH VALUES AOB 15 PERCENT AND SUSTAINED SURFACE WIND SPEEDS OF 20-25 MPH/ FROM CNTRL WY S-SWWD INTO PORTIONS OF UT/WRN CO AND NRN AZ. THE TROUGH THEN EJECTS INTO THE GREAT PLAINS ON FRIDAY/D4. MODEL GUIDANCE INDICATES INCREASING POTENTIAL FOR MODERATELY STRONG DOWNSLOPE WINDS ALONG THE LEE OF THE FRONT RANGE OF THE CNTRL ROCKIES AND ADJACENT HIGH PLAINS...WHICH MAY LEAD TO RAPID DRYING AND CRITICAL FIRE WEATHER CONDITIONS AS THE TROUGH PASSES ACROSS THE REGION. THIS AREA WILL BE MONITORED CLOSELY FOR A POSSIBLE UPGRADE IN FUTURE OUTLOOKS. THE CNTRL CONUS TROUGH IS THEN FORECAST TO EJECT NEWD TOWARD THE UPR MS VALLEY REGION ON SATURDAY/D5...FOLLOWED BY A DECREASING POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DURING THE D6-8 PERIOD. ..GARNER.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CDT TUE SEP 07 2010 VALID 091200Z - 151200Z AN UPPER LEVEL TROUGH IS FORECAST TO MOVE E-NEWD ACROSS THE GREAT BASIN ON THURSDAY/D3...AND WILL FOCUS A ZONE OF NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /RH VALUES AOB 15 PERCENT AND SUSTAINED SURFACE WIND SPEEDS OF 20-25 MPH/ FROM CNTRL WY S-SWWD INTO PORTIONS OF UT/WRN CO AND NRN AZ. THE TROUGH THEN EJECTS INTO THE GREAT PLAINS ON FRIDAY/D4. MODEL GUIDANCE INDICATES INCREASING POTENTIAL FOR MODERATELY STRONG DOWNSLOPE WINDS ALONG THE LEE OF THE FRONT RANGE OF THE CNTRL ROCKIES AND ADJACENT HIGH PLAINS...WHICH MAY LEAD TO RAPID DRYING AND CRITICAL FIRE WEATHER CONDITIONS AS THE TROUGH PASSES ACROSS THE REGION. THIS AREA WILL BE MONITORED CLOSELY FOR A POSSIBLE UPGRADE IN FUTURE OUTLOOKS. THE CNTRL CONUS TROUGH IS THEN FORECAST TO EJECT NEWD TOWARD THE UPR MS VALLEY REGION ON SATURDAY/D5...FOLLOWED BY A DECREASING POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DURING THE D6-8 PERIOD. ..GARNER.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CDT TUE SEP 07 2010 VALID 091200Z - 151200Z AN UPPER LEVEL TROUGH IS FORECAST TO MOVE E-NEWD ACROSS THE GREAT BASIN ON THURSDAY/D3...AND WILL FOCUS A ZONE OF NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /RH VALUES AOB 15 PERCENT AND SUSTAINED SURFACE WIND SPEEDS OF 20-25 MPH/ FROM CNTRL WY S-SWWD INTO PORTIONS OF UT/WRN CO AND NRN AZ. THE TROUGH THEN EJECTS INTO THE GREAT PLAINS ON FRIDAY/D4. MODEL GUIDANCE INDICATES INCREASING POTENTIAL FOR MODERATELY STRONG DOWNSLOPE WINDS ALONG THE LEE OF THE FRONT RANGE OF THE CNTRL ROCKIES AND ADJACENT HIGH PLAINS...WHICH MAY LEAD TO RAPID DRYING AND CRITICAL FIRE WEATHER CONDITIONS AS THE TROUGH PASSES ACROSS THE REGION. THIS AREA WILL BE MONITORED CLOSELY FOR A POSSIBLE UPGRADE IN FUTURE OUTLOOKS. THE CNTRL CONUS TROUGH IS THEN FORECAST TO EJECT NEWD TOWARD THE UPR MS VALLEY REGION ON SATURDAY/D5...FOLLOWED BY A DECREASING POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DURING THE D6-8 PERIOD. ..GARNER.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT TUE SEP 07 2010 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NRN/CNTRL HIGH PLAINS... HIGH LEVEL FLOW WILL BECOME INCREASINGLY DIFFLUENT INTO THE DAY2 PERIOD AS A STRONG UPPER TROUGH DIGS INTO THE WRN U.S. AND A SPEED MAX BEGINS TO EJECT ACROSS THE SRN GREAT BASIN. LEE TROUGHING WILL THEN INTENSIFY ACROSS THE NRN/CNTRL HIGH PLAINS FROM MT INTO THE NEB PANHANDLE ENABLING A RETURN OF A MORE MOIST BOUNDARY LAYER BY PEAK HEATING. IT DOES NOT APPEAR THAT SIGNIFICANT LARGE SCALE FORCING WILL OVERSPREAD THE HIGH PLAINS...THUS DIURNAL HEATING...COMBINED WITH OROGRAPHIC FORCING NEAR THE BLACK HILLS...WILL BE PRIMARILY RESPONSIBLE FOR ANY THUNDERSTORM DEVELOPMENT DURING THE LATE AFTERNOON/EARLY EVENING HOURS. WITH TIME LOW LEVEL WARM ADVECTION MAY PROMOTE ELEVATED THUNDERSTORMS ACROSS THE ERN PLAINS OF SD...BUT INSTABILITY SHOULD PROVE A BIT TOO WEAK TO WARRANT ORGANIZED SEVERE EAST OF THE MISSOURI RIVER. FARTHER WEST...WILL MAINTAIN 5% PROBABILITIES FOR ISOLATED SEVERE WIND GUSTS OR PERHAPS SOME HAIL WITH ANY SUPERCELLS THAT EVOLVE OVER THE HIGH PLAINS. ...SRN PLAINS/HERMINE... REMNANTS OF HERMINE SHOULD CONTINUE NWD INTO OK BEFORE GRADUALLY CURVING NEWD IN RESPONSE TO THE WRN U.S. TROUGH. CIRCULATION CENTER IS EXPECTED TO BECOME LESS ORGANIZED AND SHEAR PROFILES LESS FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THAT EXTENSIVE CLOUDS AND PRECIP WILL LIKELY INHIBIT SFC HEATING NEAR THE LOW. FOR THIS REASON HAVE OPTED TO REDUCE THE 5% PROBS ACROSS OK/TX...THOUGH A FEW WEAK SUPERCELLS MAY BE NOTED ALONG ERN PERIPHERY OF STORM TRACK. ..DARROW.. 09/07/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT TUE SEP 07 2010 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NRN/CNTRL HIGH PLAINS... HIGH LEVEL FLOW WILL BECOME INCREASINGLY DIFFLUENT INTO THE DAY2 PERIOD AS A STRONG UPPER TROUGH DIGS INTO THE WRN U.S. AND A SPEED MAX BEGINS TO EJECT ACROSS THE SRN GREAT BASIN. LEE TROUGHING WILL THEN INTENSIFY ACROSS THE NRN/CNTRL HIGH PLAINS FROM MT INTO THE NEB PANHANDLE ENABLING A RETURN OF A MORE MOIST BOUNDARY LAYER BY PEAK HEATING. IT DOES NOT APPEAR THAT SIGNIFICANT LARGE SCALE FORCING WILL OVERSPREAD THE HIGH PLAINS...THUS DIURNAL HEATING...COMBINED WITH OROGRAPHIC FORCING NEAR THE BLACK HILLS...WILL BE PRIMARILY RESPONSIBLE FOR ANY THUNDERSTORM DEVELOPMENT DURING THE LATE AFTERNOON/EARLY EVENING HOURS. WITH TIME LOW LEVEL WARM ADVECTION MAY PROMOTE ELEVATED THUNDERSTORMS ACROSS THE ERN PLAINS OF SD...BUT INSTABILITY SHOULD PROVE A BIT TOO WEAK TO WARRANT ORGANIZED SEVERE EAST OF THE MISSOURI RIVER. FARTHER WEST...WILL MAINTAIN 5% PROBABILITIES FOR ISOLATED SEVERE WIND GUSTS OR PERHAPS SOME HAIL WITH ANY SUPERCELLS THAT EVOLVE OVER THE HIGH PLAINS. ...SRN PLAINS/HERMINE... REMNANTS OF HERMINE SHOULD CONTINUE NWD INTO OK BEFORE GRADUALLY CURVING NEWD IN RESPONSE TO THE WRN U.S. TROUGH. CIRCULATION CENTER IS EXPECTED TO BECOME LESS ORGANIZED AND SHEAR PROFILES LESS FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THAT EXTENSIVE CLOUDS AND PRECIP WILL LIKELY INHIBIT SFC HEATING NEAR THE LOW. FOR THIS REASON HAVE OPTED TO REDUCE THE 5% PROBS ACROSS OK/TX...THOUGH A FEW WEAK SUPERCELLS MAY BE NOTED ALONG ERN PERIPHERY OF STORM TRACK. ..DARROW.. 09/07/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT TUE SEP 07 2010 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NRN/CNTRL HIGH PLAINS... HIGH LEVEL FLOW WILL BECOME INCREASINGLY DIFFLUENT INTO THE DAY2 PERIOD AS A STRONG UPPER TROUGH DIGS INTO THE WRN U.S. AND A SPEED MAX BEGINS TO EJECT ACROSS THE SRN GREAT BASIN. LEE TROUGHING WILL THEN INTENSIFY ACROSS THE NRN/CNTRL HIGH PLAINS FROM MT INTO THE NEB PANHANDLE ENABLING A RETURN OF A MORE MOIST BOUNDARY LAYER BY PEAK HEATING. IT DOES NOT APPEAR THAT SIGNIFICANT LARGE SCALE FORCING WILL OVERSPREAD THE HIGH PLAINS...THUS DIURNAL HEATING...COMBINED WITH OROGRAPHIC FORCING NEAR THE BLACK HILLS...WILL BE PRIMARILY RESPONSIBLE FOR ANY THUNDERSTORM DEVELOPMENT DURING THE LATE AFTERNOON/EARLY EVENING HOURS. WITH TIME LOW LEVEL WARM ADVECTION MAY PROMOTE ELEVATED THUNDERSTORMS ACROSS THE ERN PLAINS OF SD...BUT INSTABILITY SHOULD PROVE A BIT TOO WEAK TO WARRANT ORGANIZED SEVERE EAST OF THE MISSOURI RIVER. FARTHER WEST...WILL MAINTAIN 5% PROBABILITIES FOR ISOLATED SEVERE WIND GUSTS OR PERHAPS SOME HAIL WITH ANY SUPERCELLS THAT EVOLVE OVER THE HIGH PLAINS. ...SRN PLAINS/HERMINE... REMNANTS OF HERMINE SHOULD CONTINUE NWD INTO OK BEFORE GRADUALLY CURVING NEWD IN RESPONSE TO THE WRN U.S. TROUGH. CIRCULATION CENTER IS EXPECTED TO BECOME LESS ORGANIZED AND SHEAR PROFILES LESS FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THAT EXTENSIVE CLOUDS AND PRECIP WILL LIKELY INHIBIT SFC HEATING NEAR THE LOW. FOR THIS REASON HAVE OPTED TO REDUCE THE 5% PROBS ACROSS OK/TX...THOUGH A FEW WEAK SUPERCELLS MAY BE NOTED ALONG ERN PERIPHERY OF STORM TRACK. ..DARROW.. 09/07/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CDT TUE SEP 07 2010 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...NRN/CNTRL HIGH PLAINS... HIGH LEVEL FLOW WILL BECOME INCREASINGLY DIFFLUENT INTO THE DAY2 PERIOD AS A STRONG UPPER TROUGH DIGS INTO THE WRN U.S. AND A SPEED MAX BEGINS TO EJECT ACROSS THE SRN GREAT BASIN. LEE TROUGHING WILL THEN INTENSIFY ACROSS THE NRN/CNTRL HIGH PLAINS FROM MT INTO THE NEB PANHANDLE ENABLING A RETURN OF A MORE MOIST BOUNDARY LAYER BY PEAK HEATING. IT DOES NOT APPEAR THAT SIGNIFICANT LARGE SCALE FORCING WILL OVERSPREAD THE HIGH PLAINS...THUS DIURNAL HEATING...COMBINED WITH OROGRAPHIC FORCING NEAR THE BLACK HILLS...WILL BE PRIMARILY RESPONSIBLE FOR ANY THUNDERSTORM DEVELOPMENT DURING THE LATE AFTERNOON/EARLY EVENING HOURS. WITH TIME LOW LEVEL WARM ADVECTION MAY PROMOTE ELEVATED THUNDERSTORMS ACROSS THE ERN PLAINS OF SD...BUT INSTABILITY SHOULD PROVE A BIT TOO WEAK TO WARRANT ORGANIZED SEVERE EAST OF THE MISSOURI RIVER. FARTHER WEST...WILL MAINTAIN 5% PROBABILITIES FOR ISOLATED SEVERE WIND GUSTS OR PERHAPS SOME HAIL WITH ANY SUPERCELLS THAT EVOLVE OVER THE HIGH PLAINS. ...SRN PLAINS/HERMINE... REMNANTS OF HERMINE SHOULD CONTINUE NWD INTO OK BEFORE GRADUALLY CURVING NEWD IN RESPONSE TO THE WRN U.S. TROUGH. CIRCULATION CENTER IS EXPECTED TO BECOME LESS ORGANIZED AND SHEAR PROFILES LESS FAVORABLE FOR TORNADOES...ESPECIALLY GIVEN THAT EXTENSIVE CLOUDS AND PRECIP WILL LIKELY INHIBIT SFC HEATING NEAR THE LOW. FOR THIS REASON HAVE OPTED TO REDUCE THE 5% PROBS ACROSS OK/TX...THOUGH A FEW WEAK SUPERCELLS MAY BE NOTED ALONG ERN PERIPHERY OF STORM TRACK. ..DARROW.. 09/07/2010 Read more

WW 0647 Status Reports
STATUS FOR WATCH 0647 HAS NOT BEEN ISSUED YET Read more

WW 0647 Status Reports
STATUS FOR WATCH 0647 HAS NOT BEEN ISSUED YET Read more

WW 0647 Status Reports
STATUS FOR WATCH 0647 HAS NOT BEEN ISSUED YET Read more

WW 0647 Status Reports
STATUS FOR WATCH 0647 HAS NOT BEEN ISSUED YET Read more

MD 1796 CONCERNING TORNADO WATCH 646... FOR MIDDLE TX COAST...ECNTRL TX
MESOSCALE DISCUSSION 1796 NWS STORM PREDICTION CENTER NORMAN OK 1141 AM CDT TUE SEP 07 2010 AREAS AFFECTED...MIDDLE TX COAST...ECNTRL TX CONCERNING...TORNADO WATCH 646... VALID 071641Z - 071815Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 646 CONTINUES. THE TORNADO THREAT CURRENTLY ONGOING ALONG THE MIDDLE TX COAST AND IN ECNTRL TX WILL LIKELY CONTINUE THIS AFTERNOON. WW 646 IS SCHEDULED TO EXPIRE AT 18Z. A NEW TORNADO WATCH APPEARS LIKELY TO BE ISSUED FURTHER NORTH ACROSS ECNTRL TX FOR THE REMAINDER OF THE AFTERNOON. TROPICAL STORM HERMINE IS CURRENTLY LOCATED JUST SOUTH OF SAN ANTONIO WITH A DISTINCT RAINBAND EAST OF THE CENTER EXTENDING FROM PORT OCONNER ON THE TX COAST NNWWD TO NEAR WACO. THE LATEST OBJECTIVE ANALYSIS ALONG THIS CORRIDOR IS ESTIMATING 0-1 KM SHEAR VALUES AROUND 30 KT RANGE ALONG WITH PRECIPITABLE WATER VALUES IN THE 2.50 TO 2.75 INCH RANGE. THIS COMBINATION OF SHEAR AND MOISTURE SHOULD BE FAVORABLE FOR ROTATING STORMS WITH A FEW TORNADOES POSSIBLE WITH THE MORE PERSISTENT ROTATING STORMS THIS AFTERNOON. LOW-LEVEL FLOW SHOULD CONTINUE TO INCREASE NWD ACROSS ECNTRL TX SUGGESTING THE TORNADO THREAT MAY SPREAD NWD ALONG THE I-45 CORRIDOR SOUTH OF DALLAS/FORT WORTH. THE TORNADO THREAT FURTHER SOUTH ALONG THE MIDDLE TX COAST SHOULD ALSO CONTINUE AS ROTATING STORMS MOVE ONSHORE THIS AFTERNOON BETWEEN VICTORIA AND HOUSTON. ..BROYLES.. 09/07/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX...BRO... LAT...LON 27189759 27909813 29179728 29709581 29129529 28459579 27389639 27189759 Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CDT TUE SEP 07 2010 VALID 081200Z - 091200Z CORRECTED FOR SPELLING ERROR ...CRITICAL FIRE WEATHER AREA FOR ERN/SRN NV...WRN UT...NWRN AZ... ...ERN/SRN NV...WRN UT...NWRN AZ... LATEST OPERATIONAL NAM IS MOST AGGRESSIVE IN FORECASTING A LARGE AREA OF CRITICAL RH /AOB 15 PERCENT/ AND SUSTAINED WIND SPEEDS /AROUND 20-25 MPH AND GUSTS AOA 30 MPH/ OVER THE REGION...WHILE GFS AND NAMKF INDICATE SLIGHTLY MORE MARGINAL WIND SPEEDS /MAX SPEEDS AROUND 20 MPH WITH LOWER GUST POTENTIAL/ AND HIGHER RH VALUES /15-20 PERCENT/. AS MENTIONED IN THE PREVIOUS D2 FORECAST...THE EWD EXTENT OF CRITICAL CONDITIONS IS ALSO IN QUESTION...AND THE MAGNITUDE AND SUBSEQUENT IMPACT FROM D1 RAINFALL MAY NEGATIVELY INFLUENCE D2 MIXING HEIGHTS AND MIN RH VALUES. DUE TO THESE UNCERTAINTIES...NO CHANGES WILL BE MADE TO THE CRITICAL AREA ATTM...BUT ADJUSTMENTS MAY BE REQUIRED DURING THE NEXT D1 OUTLOOK. ...FAR S-CNTRL/SERN PA...SRN NJ...NRN DE...CNTRL MD...ERN WV PANHANDLE...NRN VA...D.C.... NO CHANGES MADE TO THE PREVIOUS FORECAST. ..GARNER.. 09/07/2010 .PREV DISCUSSION... /ISSUED 0457 AM CDT TUE SEP 07 2010/ ...SYNOPSIS... LARGE-SCALE UPPER-LEVEL TROUGH WILL REMAIN ANCHORED ACROSS THE WRN CONUS...WITH A VIGOROUS SHORT WAVE IMPULSE ROTATING THROUGH THE BASE OF THE TROUGH ACROSS CA INTO THE WRN GREAT BASIN THROUGH EARLY THU. PRIMARY SURFACE CYCLONE SHOULD BECOME CENTERED OVER NERN NV/NWRN UT BY WED AFTERNOON...WITH AN ATTENDANT COLD FRONT DRAPED SWWD TOWARDS THE SRN SIERRAS. IN THE EAST...AN UPPER-LEVEL SHORT WAVE TROUGH WILL DECELERATE AS IT PROGRESSES EWD FROM SRN ONTARIO INTO NEW ENGLAND. ASSOCIATED SURFACE COLD FRONT WILL SHIFT EAST OF THE NRN/CNTRL APPALACHIANS WED MORNING REACHING THE NORTHEAST/MID-ATLANTIC COAST BY WED AFTERNOON. ...ERN/SRN NV...WRN UT...NWRN AZ... A BROAD SWATH OF MODERATELY STRONG LOW/MID-LEVEL SWLYS WILL ENVELOP MUCH OF THE CNTRL/SRN GREAT BASIN BY WED AFTERNOON. DEEPLY MIXED THERMODYNAMIC PROFILES WILL EXIST BETWEEN A COLD FRONT PUSHING ACROSS WRN NV AND RICHER SUB-TROPICAL MOISTURE CENTERED ALONG THE LONGITUDE OF THE FOUR CORNERS. WIDESPREAD SUSTAINED SURFACE WINDS OF 20 TO 25 MPH /WITH AREAS NEAR 30 MPH/ ARE EXPECTED TO BE JUXTAPOSED WITH RH VALUES AOB 15 PERCENT. UNCERTAINTY EXISTS WITH THE ERN EXTENT OF LOW RH GIVEN MODERATE SPREAD AMONGST MODEL GUIDANCE WITH THE DEGREE OF MIXING ON THE WRN PERIPHERY OF THE SUB-TROPICAL MOISTURE PLUME. ...FAR S-CNTRL/SERN PA...SRN NJ...NRN DE...CNTRL MD...ERN WV PANHANDLE...NRN VA...D.C.... MARGINAL TO LOCALIZED CRITICAL CONDITIONS SHOULD DEVELOP DURING WED AFTERNOON IN THE WAKE OF A COLD FRONT PASSAGE DURING THE MORNING. A MODERATE LOW-LEVEL PRESSURE GRADIENT SHOULD SUPPORT SUSTAINED SURFACE WINDS AROUND 15 MPH...WITH GUSTS OF 25 TO PERHAPS 30 MPH AS DEEPER MIXING ENSUES. 06Z NAM/00Z GFS FORECASTS ARE RATHER CONSISTENT WITH THE INDICATION OF RH VALUES FALLING TO BETWEEN 20 AND 30 PERCENT. ALTHOUGH ISOLATED TSTMS ARE POSSIBLE IN ASSOCIATION WITH THE FRONTAL PASSAGE OVER THE HIGHER TERRAIN EARLY WED...WELL BELOW-NORMAL RAINFALL HAS PERSISTED ACROSS THE REGION DURING THE PAST FEW WEEKS...SUPPORTIVE OF ELEVATED FIRE WEATHER POTENTIAL. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more