SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CDT SAT SEP 04 2010 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...MT... SURFACE ANALYSIS SHOWS A DIFFUSE TROUGH FROM SRN ID INTO NRN MT...WITH ANOTHER AXIS FROM NRN MT SWD ACROSS THE NRN HIGH PLAINS. CONVECTION WILL CONTINUE TO INCREASE AHEAD OF THE UPPER TROUGH WHERE MARGINAL INSTABILITY HAS DEVELOPED. COOL TEMPERATURES ALOFT AND STRONG DEEP LAYER SHEAR MAY YIELD MARGINALLY SEVERE HAIL...AND STEEPENING LOW LEVEL LAPSE RATES MAY ENHANCE WIND GUST POTENTIAL. FOR MORE INFORMATION...SEE MESOSCALE DISCUSSION 1789. ..JEWELL.. 09/04/2010 .PREV DISCUSSION... /ISSUED 1130 AM CDT SAT SEP 04 2010/ ...WRN/CENTRAL MT AREA THIS AFTERNOON/EVENING... A MIDLEVEL SHORTWAVE TROUGH OVER BC/WA WILL AMPLIFY SEWD OVER THE NRN ROCKIES AS AN ASSOCIATED COLD FRONT MOVES SEWD ACROSS MT THIS AFTERNOON THROUGH TONIGHT. THE MIDLEVEL TROUGH IS PRECEDED BY A NARROW PLUME OF MIDLEVEL MOISTURE ACROSS NRN ID/WRN MT...AND MODIFIED REGIONAL SOUNDINGS INDICATE THE POTENTIAL FOR AT LEAST WEAK INSTABILITY AND DEEP INVERTED-V PROFILES THIS AFTERNOON AHEAD OF THE FRONT. THESE PROFILES WILL SUPPORT HIGH-BASED THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE STRONG/ISOLATED DAMAGING GUSTS THIS AFTERNOON/EVENING ACROSS WRN/CENTRAL MT AS MIDLEVEL FLOW INCREASES. THE PRIMARY LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT IS WEAK INSTABILITY. ...ELSEWHERE ACROSS THE CONUS... DEEP DRYING IN THE WAKE OF A DEEP MIDLEVEL TROUGH OVER THE LOWER GREAT LAKES/NEW ENGLAND...AND AN ASSOCIATED COLD FRONT MOVING OVER THE NRN GULF OF MEXICO...WILL LIMIT THUNDERSTORM POTENTIAL ACROSS THE MAJORITY OF THE CONUS. THE PRIMARY EXCEPTION WILL BE NEAR THE SLOW-MOVING FRONT ACROSS S TX AND FL...WITHIN THE REMAINING TROPICAL MOISTURE PLUME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CDT SAT SEP 04 2010 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...MT... SURFACE ANALYSIS SHOWS A DIFFUSE TROUGH FROM SRN ID INTO NRN MT...WITH ANOTHER AXIS FROM NRN MT SWD ACROSS THE NRN HIGH PLAINS. CONVECTION WILL CONTINUE TO INCREASE AHEAD OF THE UPPER TROUGH WHERE MARGINAL INSTABILITY HAS DEVELOPED. COOL TEMPERATURES ALOFT AND STRONG DEEP LAYER SHEAR MAY YIELD MARGINALLY SEVERE HAIL...AND STEEPENING LOW LEVEL LAPSE RATES MAY ENHANCE WIND GUST POTENTIAL. FOR MORE INFORMATION...SEE MESOSCALE DISCUSSION 1789. ..JEWELL.. 09/04/2010 .PREV DISCUSSION... /ISSUED 1130 AM CDT SAT SEP 04 2010/ ...WRN/CENTRAL MT AREA THIS AFTERNOON/EVENING... A MIDLEVEL SHORTWAVE TROUGH OVER BC/WA WILL AMPLIFY SEWD OVER THE NRN ROCKIES AS AN ASSOCIATED COLD FRONT MOVES SEWD ACROSS MT THIS AFTERNOON THROUGH TONIGHT. THE MIDLEVEL TROUGH IS PRECEDED BY A NARROW PLUME OF MIDLEVEL MOISTURE ACROSS NRN ID/WRN MT...AND MODIFIED REGIONAL SOUNDINGS INDICATE THE POTENTIAL FOR AT LEAST WEAK INSTABILITY AND DEEP INVERTED-V PROFILES THIS AFTERNOON AHEAD OF THE FRONT. THESE PROFILES WILL SUPPORT HIGH-BASED THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE STRONG/ISOLATED DAMAGING GUSTS THIS AFTERNOON/EVENING ACROSS WRN/CENTRAL MT AS MIDLEVEL FLOW INCREASES. THE PRIMARY LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT IS WEAK INSTABILITY. ...ELSEWHERE ACROSS THE CONUS... DEEP DRYING IN THE WAKE OF A DEEP MIDLEVEL TROUGH OVER THE LOWER GREAT LAKES/NEW ENGLAND...AND AN ASSOCIATED COLD FRONT MOVING OVER THE NRN GULF OF MEXICO...WILL LIMIT THUNDERSTORM POTENTIAL ACROSS THE MAJORITY OF THE CONUS. THE PRIMARY EXCEPTION WILL BE NEAR THE SLOW-MOVING FRONT ACROSS S TX AND FL...WITHIN THE REMAINING TROPICAL MOISTURE PLUME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CDT SAT SEP 04 2010 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...MT... SURFACE ANALYSIS SHOWS A DIFFUSE TROUGH FROM SRN ID INTO NRN MT...WITH ANOTHER AXIS FROM NRN MT SWD ACROSS THE NRN HIGH PLAINS. CONVECTION WILL CONTINUE TO INCREASE AHEAD OF THE UPPER TROUGH WHERE MARGINAL INSTABILITY HAS DEVELOPED. COOL TEMPERATURES ALOFT AND STRONG DEEP LAYER SHEAR MAY YIELD MARGINALLY SEVERE HAIL...AND STEEPENING LOW LEVEL LAPSE RATES MAY ENHANCE WIND GUST POTENTIAL. FOR MORE INFORMATION...SEE MESOSCALE DISCUSSION 1789. ..JEWELL.. 09/04/2010 .PREV DISCUSSION... /ISSUED 1130 AM CDT SAT SEP 04 2010/ ...WRN/CENTRAL MT AREA THIS AFTERNOON/EVENING... A MIDLEVEL SHORTWAVE TROUGH OVER BC/WA WILL AMPLIFY SEWD OVER THE NRN ROCKIES AS AN ASSOCIATED COLD FRONT MOVES SEWD ACROSS MT THIS AFTERNOON THROUGH TONIGHT. THE MIDLEVEL TROUGH IS PRECEDED BY A NARROW PLUME OF MIDLEVEL MOISTURE ACROSS NRN ID/WRN MT...AND MODIFIED REGIONAL SOUNDINGS INDICATE THE POTENTIAL FOR AT LEAST WEAK INSTABILITY AND DEEP INVERTED-V PROFILES THIS AFTERNOON AHEAD OF THE FRONT. THESE PROFILES WILL SUPPORT HIGH-BASED THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE STRONG/ISOLATED DAMAGING GUSTS THIS AFTERNOON/EVENING ACROSS WRN/CENTRAL MT AS MIDLEVEL FLOW INCREASES. THE PRIMARY LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT IS WEAK INSTABILITY. ...ELSEWHERE ACROSS THE CONUS... DEEP DRYING IN THE WAKE OF A DEEP MIDLEVEL TROUGH OVER THE LOWER GREAT LAKES/NEW ENGLAND...AND AN ASSOCIATED COLD FRONT MOVING OVER THE NRN GULF OF MEXICO...WILL LIMIT THUNDERSTORM POTENTIAL ACROSS THE MAJORITY OF THE CONUS. THE PRIMARY EXCEPTION WILL BE NEAR THE SLOW-MOVING FRONT ACROSS S TX AND FL...WITHIN THE REMAINING TROPICAL MOISTURE PLUME. Read more

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CDT SAT SEP 04 2010 VALID 042000Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...MT... SURFACE ANALYSIS SHOWS A DIFFUSE TROUGH FROM SRN ID INTO NRN MT...WITH ANOTHER AXIS FROM NRN MT SWD ACROSS THE NRN HIGH PLAINS. CONVECTION WILL CONTINUE TO INCREASE AHEAD OF THE UPPER TROUGH WHERE MARGINAL INSTABILITY HAS DEVELOPED. COOL TEMPERATURES ALOFT AND STRONG DEEP LAYER SHEAR MAY YIELD MARGINALLY SEVERE HAIL...AND STEEPENING LOW LEVEL LAPSE RATES MAY ENHANCE WIND GUST POTENTIAL. FOR MORE INFORMATION...SEE MESOSCALE DISCUSSION 1789. ..JEWELL.. 09/04/2010 .PREV DISCUSSION... /ISSUED 1130 AM CDT SAT SEP 04 2010/ ...WRN/CENTRAL MT AREA THIS AFTERNOON/EVENING... A MIDLEVEL SHORTWAVE TROUGH OVER BC/WA WILL AMPLIFY SEWD OVER THE NRN ROCKIES AS AN ASSOCIATED COLD FRONT MOVES SEWD ACROSS MT THIS AFTERNOON THROUGH TONIGHT. THE MIDLEVEL TROUGH IS PRECEDED BY A NARROW PLUME OF MIDLEVEL MOISTURE ACROSS NRN ID/WRN MT...AND MODIFIED REGIONAL SOUNDINGS INDICATE THE POTENTIAL FOR AT LEAST WEAK INSTABILITY AND DEEP INVERTED-V PROFILES THIS AFTERNOON AHEAD OF THE FRONT. THESE PROFILES WILL SUPPORT HIGH-BASED THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE STRONG/ISOLATED DAMAGING GUSTS THIS AFTERNOON/EVENING ACROSS WRN/CENTRAL MT AS MIDLEVEL FLOW INCREASES. THE PRIMARY LIMITING FACTOR FOR A MORE ROBUST DAMAGING WIND THREAT IS WEAK INSTABILITY. ...ELSEWHERE ACROSS THE CONUS... DEEP DRYING IN THE WAKE OF A DEEP MIDLEVEL TROUGH OVER THE LOWER GREAT LAKES/NEW ENGLAND...AND AN ASSOCIATED COLD FRONT MOVING OVER THE NRN GULF OF MEXICO...WILL LIMIT THUNDERSTORM POTENTIAL ACROSS THE MAJORITY OF THE CONUS. THE PRIMARY EXCEPTION WILL BE NEAR THE SLOW-MOVING FRONT ACROSS S TX AND FL...WITHIN THE REMAINING TROPICAL MOISTURE PLUME. Read more

SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0235 PM CDT SAT SEP 04 2010 VALID 061200Z - 121200Z A STRONG UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO EJECT EWD INTO THE GREAT PLAINS ON MONDAY/D3...ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT. AS THE SURFACE LOW APPROACHES THE UPR MS VALLEY REGION DURING THE AFTERNOON...A COLD FRONT WILL DROP SWD AND ARC ACROSS KS INTO WRN OK AND THE TX/OK PANHANDLES. STRONG POST FRONTAL WINDS WILL LIKELY OCCUR INVOF THE CO FRONT RANGE AND ADJACENT HIGH PLAINS...WHICH MAY FAVOR LOCALLY CRITICAL FIRE WEATHER CONDITIONS WHERE RH VALUES FALL INTO THE TEENS. FARTHER S...BREEZY SOUTHERLY WINDS ARE INDICATED BY SOME MODEL GUIDANCE AHEAD OF THE FRONT OVER SRN KS...OK...AND THE TX PANHANDLE /WITH SUSTAINED SPEEDS AOA 20 MPH/. HOWEVER...RH VALUES ARE CURRENTLY EXPECTED TO BE TOO HIGH TO SUPPORT AN OUTLOOK AREA. TOWARD MID WEEK...ANOTHER UPPER TROUGH WILL DIG ALONG THE W COAST AND THEN EJECT EWD ACROSS THE GREAT BASIN. AS THIS TAKES PLACE...MODEL GUIDANCE INDICATES NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /FOR STRONG SUSTAINED WINDS AND LOW RH VALUES/ WILL BE POSSIBLE ON WEDNESDAY/D5 OVER PORTIONS OF ERN NV...AND THEN WY SWD TOWARD THE FOUR CORNERS REGION ON THURSDAY/D6. THESE REGIONS WILL CONTINUE TO BE MONITORED DURING FUTURE OUTLOOKS...AND MAY REQUIRE CRITICAL AREAS AS FORECAST CONFIDENCE INCREASES. ..GARNER.. 09/04/2010 ...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 0235 PM CDT SAT SEP 04 2010 VALID 061200Z - 121200Z A STRONG UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO EJECT EWD INTO THE GREAT PLAINS ON MONDAY/D3...ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT. AS THE SURFACE LOW APPROACHES THE UPR MS VALLEY REGION DURING THE AFTERNOON...A COLD FRONT WILL DROP SWD AND ARC ACROSS KS INTO WRN OK AND THE TX/OK PANHANDLES. STRONG POST FRONTAL WINDS WILL LIKELY OCCUR INVOF THE CO FRONT RANGE AND ADJACENT HIGH PLAINS...WHICH MAY FAVOR LOCALLY CRITICAL FIRE WEATHER CONDITIONS WHERE RH VALUES FALL INTO THE TEENS. FARTHER S...BREEZY SOUTHERLY WINDS ARE INDICATED BY SOME MODEL GUIDANCE AHEAD OF THE FRONT OVER SRN KS...OK...AND THE TX PANHANDLE /WITH SUSTAINED SPEEDS AOA 20 MPH/. HOWEVER...RH VALUES ARE CURRENTLY EXPECTED TO BE TOO HIGH TO SUPPORT AN OUTLOOK AREA. TOWARD MID WEEK...ANOTHER UPPER TROUGH WILL DIG ALONG THE W COAST AND THEN EJECT EWD ACROSS THE GREAT BASIN. AS THIS TAKES PLACE...MODEL GUIDANCE INDICATES NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /FOR STRONG SUSTAINED WINDS AND LOW RH VALUES/ WILL BE POSSIBLE ON WEDNESDAY/D5 OVER PORTIONS OF ERN NV...AND THEN WY SWD TOWARD THE FOUR CORNERS REGION ON THURSDAY/D6. THESE REGIONS WILL CONTINUE TO BE MONITORED DURING FUTURE OUTLOOKS...AND MAY REQUIRE CRITICAL AREAS AS FORECAST CONFIDENCE INCREASES. ..GARNER.. 09/04/2010 ...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 0235 PM CDT SAT SEP 04 2010 VALID 061200Z - 121200Z A STRONG UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO EJECT EWD INTO THE GREAT PLAINS ON MONDAY/D3...ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT. AS THE SURFACE LOW APPROACHES THE UPR MS VALLEY REGION DURING THE AFTERNOON...A COLD FRONT WILL DROP SWD AND ARC ACROSS KS INTO WRN OK AND THE TX/OK PANHANDLES. STRONG POST FRONTAL WINDS WILL LIKELY OCCUR INVOF THE CO FRONT RANGE AND ADJACENT HIGH PLAINS...WHICH MAY FAVOR LOCALLY CRITICAL FIRE WEATHER CONDITIONS WHERE RH VALUES FALL INTO THE TEENS. FARTHER S...BREEZY SOUTHERLY WINDS ARE INDICATED BY SOME MODEL GUIDANCE AHEAD OF THE FRONT OVER SRN KS...OK...AND THE TX PANHANDLE /WITH SUSTAINED SPEEDS AOA 20 MPH/. HOWEVER...RH VALUES ARE CURRENTLY EXPECTED TO BE TOO HIGH TO SUPPORT AN OUTLOOK AREA. TOWARD MID WEEK...ANOTHER UPPER TROUGH WILL DIG ALONG THE W COAST AND THEN EJECT EWD ACROSS THE GREAT BASIN. AS THIS TAKES PLACE...MODEL GUIDANCE INDICATES NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /FOR STRONG SUSTAINED WINDS AND LOW RH VALUES/ WILL BE POSSIBLE ON WEDNESDAY/D5 OVER PORTIONS OF ERN NV...AND THEN WY SWD TOWARD THE FOUR CORNERS REGION ON THURSDAY/D6. THESE REGIONS WILL CONTINUE TO BE MONITORED DURING FUTURE OUTLOOKS...AND MAY REQUIRE CRITICAL AREAS AS FORECAST CONFIDENCE INCREASES. ..GARNER.. 09/04/2010 ...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 0235 PM CDT SAT SEP 04 2010 VALID 061200Z - 121200Z A STRONG UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO EJECT EWD INTO THE GREAT PLAINS ON MONDAY/D3...ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT. AS THE SURFACE LOW APPROACHES THE UPR MS VALLEY REGION DURING THE AFTERNOON...A COLD FRONT WILL DROP SWD AND ARC ACROSS KS INTO WRN OK AND THE TX/OK PANHANDLES. STRONG POST FRONTAL WINDS WILL LIKELY OCCUR INVOF THE CO FRONT RANGE AND ADJACENT HIGH PLAINS...WHICH MAY FAVOR LOCALLY CRITICAL FIRE WEATHER CONDITIONS WHERE RH VALUES FALL INTO THE TEENS. FARTHER S...BREEZY SOUTHERLY WINDS ARE INDICATED BY SOME MODEL GUIDANCE AHEAD OF THE FRONT OVER SRN KS...OK...AND THE TX PANHANDLE /WITH SUSTAINED SPEEDS AOA 20 MPH/. HOWEVER...RH VALUES ARE CURRENTLY EXPECTED TO BE TOO HIGH TO SUPPORT AN OUTLOOK AREA. TOWARD MID WEEK...ANOTHER UPPER TROUGH WILL DIG ALONG THE W COAST AND THEN EJECT EWD ACROSS THE GREAT BASIN. AS THIS TAKES PLACE...MODEL GUIDANCE INDICATES NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /FOR STRONG SUSTAINED WINDS AND LOW RH VALUES/ WILL BE POSSIBLE ON WEDNESDAY/D5 OVER PORTIONS OF ERN NV...AND THEN WY SWD TOWARD THE FOUR CORNERS REGION ON THURSDAY/D6. THESE REGIONS WILL CONTINUE TO BE MONITORED DURING FUTURE OUTLOOKS...AND MAY REQUIRE CRITICAL AREAS AS FORECAST CONFIDENCE INCREASES. ..GARNER.. 09/04/2010 ...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 0235 PM CDT SAT SEP 04 2010 VALID 061200Z - 121200Z A STRONG UPPER LEVEL SHORTWAVE TROUGH IS FORECAST TO EJECT EWD INTO THE GREAT PLAINS ON MONDAY/D3...ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT. AS THE SURFACE LOW APPROACHES THE UPR MS VALLEY REGION DURING THE AFTERNOON...A COLD FRONT WILL DROP SWD AND ARC ACROSS KS INTO WRN OK AND THE TX/OK PANHANDLES. STRONG POST FRONTAL WINDS WILL LIKELY OCCUR INVOF THE CO FRONT RANGE AND ADJACENT HIGH PLAINS...WHICH MAY FAVOR LOCALLY CRITICAL FIRE WEATHER CONDITIONS WHERE RH VALUES FALL INTO THE TEENS. FARTHER S...BREEZY SOUTHERLY WINDS ARE INDICATED BY SOME MODEL GUIDANCE AHEAD OF THE FRONT OVER SRN KS...OK...AND THE TX PANHANDLE /WITH SUSTAINED SPEEDS AOA 20 MPH/. HOWEVER...RH VALUES ARE CURRENTLY EXPECTED TO BE TOO HIGH TO SUPPORT AN OUTLOOK AREA. TOWARD MID WEEK...ANOTHER UPPER TROUGH WILL DIG ALONG THE W COAST AND THEN EJECT EWD ACROSS THE GREAT BASIN. AS THIS TAKES PLACE...MODEL GUIDANCE INDICATES NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS /FOR STRONG SUSTAINED WINDS AND LOW RH VALUES/ WILL BE POSSIBLE ON WEDNESDAY/D5 OVER PORTIONS OF ERN NV...AND THEN WY SWD TOWARD THE FOUR CORNERS REGION ON THURSDAY/D6. THESE REGIONS WILL CONTINUE TO BE MONITORED DURING FUTURE OUTLOOKS...AND MAY REQUIRE CRITICAL AREAS AS FORECAST CONFIDENCE INCREASES. ..GARNER.. 09/04/2010 ...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 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY STRONG UPPER TROUGH /WITH -22 C AT 500 MB/ WILL CONTINUE TO MOVE SEWD ACROSS THE PACIFIC NW AND NRN ROCKIES...EMERGING INTO THE CNTRL/NRN HIGH PLAINS BY 12Z MON. AT THE SURFACE...A COLD FRONT WILL EXTEND FROM SERN MT/ERN WY SWWD INTO THE GREAT BASIN AT 00Z. MEANWHILE...A BROAD AREA OF LOW PRESSURE WILL DEEPEN ACROSS THE PLAINS...WITH A LOW CENTER ACROSS WRN NEB SUN AFTERNOON. GIVEN LOW LEVEL TRAJECTORIES OUT OF THE SERN U.S. HIGH...MOISTURE AND INSTABILITY WILL BE QUITE LIMITED ACROSS THE NRN HIGH PLAINS. ELSEWHERE...INSTABILITY WILL REMAIN OVER THE FL PENINSULA WITH A FEW AFTERNOON STORMS AS WELL AS ALONG THE WRN AND CNTRL GULF COAST WITH ISOLATED SEA-BREEZE CONVECTION POSSIBLE. ...SERN MT...NRN WY...WRN SD... SCATTERED STORMS WILL LIKELY BE ONGOING SUN MORNING ACROSS SRN MT NEAR A DEVELOPING COLD FRONT. SURFACE CONVERGENCE WILL INCREASE DURING THE DAY OVER SRN MT AND NRN WY...WHILE LOW LEVEL LAPSE RATES STEEPEN AND MARGINAL INSTABILITY DEVELOPS AHEAD OF THE FRONT. FORECAST SOUNDINGS SHOW RELATIVELY COOL PROFILES ALOFT AND DEEP LAYER SHEAR FAVORABLE FOR SUPERCELLS...AND THIS WILL FAVOR AT LEAST MARGINALLY SEVERE HAIL. A FEW SEVERE WIND GUSTS WILL BE INCREASINGLY LIKELY BY LATE IN THE DAY OVER NERN WY...SERN MT AND THE WRN DAKOTAS AS PEAK HEATING IS REACHED AND CONVECTIVE OUTFLOWS MERGE. ..JEWELL.. 09/04/2010 Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... LATEST MODEL GUIDANCE CONTINUES TO INDICATE A STRONG UPPER JET STREAK /100-120 KT AT 250 MB/ MOVING ACROSS THE NRN GREAT BASIN DURING SUNDAY AFTERNOON...WHICH WILL SUPPORT THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS /SUSTAINED WIND SPEEDS AOA 25 MPH FOR MANY LOCATIONS WITH RH VALUES BELOW 15 PERCENT/ ACROSS MOST OF THE ERN GREAT BASIN INTO PORTIONS OF THE CNTRL ROCKIES. STRONG POST FRONTAL SURFACE WIND SPEEDS /20-30 MPH/ ARE ALSO INDICATED OVER S-CNTRL/SERN ID INTO PORTIONS OF NWRN UT AND NERN NV...WHICH WILL SUPPORT CRITICAL CONDITIONS AS WELL...DESPITE THE PRESENCE OF SLIGHTLY MORE MARGINAL RH VALUES. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... LOW-LEVEL CYCLOGENESIS OVER THE CNTRL HIGH PLAINS WILL AID IN THE DEVELOPMENT OF A 30-40 KT S-SWLY LOW-LEVEL JET DURING THE MID TO LATE AFTERNOON...WHILE A HOT/STEEP LAPSE RATE AIR MASS SPREADS EWD ACROSS THE TX/OK PANHANDLES AND SWRN KS. THOUGH A ZONE OF CRITICALLY LOW RH SHOULD BE FAVORABLY JUXTAPOSED WITH CRITICALLY STRONG WIND SPEEDS DURING SUNDAY AFTERNOON...UNCERTAINTY EXISTS ON WHERE A LOW-LEVEL TROUGH AXIS WILL SET UP /WHICH WILL INFLUENCE WHERE THE LOW RH/STRONG WIND OVERLAP WILL BE LOCATED/. THEREFORE...WILL WAIT TO ISSUE A CRITICAL OUTLOOK AREA UNTIL GREATER CONFIDENCE IN THIS SCENARIO DEVELOPS. ...NRN SACRAMENTO VALLEY IN NRN CA... NO CHANGES MADE TO THE PREVIOUS FORECAST. ...SRN CA DESERTS... NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING OVER THE DESERTS OF SRN CA AS ONSHORE FLOW REGIME STRENGTHENS IN RESPONSE TO INCREASING PRESSURE GRADIENT...LEADING TO SUSTAINED WIND SPEEDS OF 20 MPH OCCURRING IN THE MIDST OF RH VALUES NEAR 5 PERCENT. ...MID-ATLANTIC REGION /NJ INTO NRN-ERN VA/... LATEST MODEL GUIDANCE INDICATES AFTERNOON RH VALUES MAY BRIEFLY DROP BELOW 30 PERCENT ON SUNDAY. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN AOB 10 MPH...WHICH WILL PRECLUDE A MORE SIGNIFICANT FIRE WEATHER THREAT. ..GARNER.. 09/04/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT SAT SEP 04 2010/ ...SYNOPSIS... A LARGE-SCALE UPPER-LEVEL TROUGH WILL CONTINUE TO DIG ACROSS THE NWRN CONUS AND PROGRESS EWD TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY MON. MID-LEVEL WLYS WILL STRENGTHEN WITH A BELT OF 50 TO 70 MPH FLOW AT 500 MB CENTERED ACROSS NRN NV/SRN ID INTO WY ON SUN AFTERNOON. AT THE SURFACE...A SHARP COLD FRONT WILL SWEEP SWD THROUGH THE GREAT BASIN...WITH TIGHT THERMAL AND PRESSURE GRADIENTS DEVELOPING IN ITS WAKE. ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... WIDESPREAD CRITICAL CONDITIONS APPEAR LIKELY SUN AFTERNOON AHEAD OF A SHARP COLD FRONT ACROSS NRN AZ...SRN/ERN UT...NRN/WRN CO AND CNTRL/SRN WY. SUSTAINED SURFACE WINDS WILL INCREASE TO 20 TO 30 MPH...WITH WIND GUSTS LOCALLY REACHING 40 TO 50 MPH OVER PORTIONS OF SRN WY/NWRN CO. THIS WILL COINCIDE WITH AN ANTECEDENT VERY WARM/DRY AIR MASS /RH VALUES OF 5 TO 15 PERCENT/. THE CRITICAL AREA HAS BEEN EXTENDED FARTHER NW INTO NERN NV/NWRN UT/SERN ID. HERE...STRONG SURFACE WINDS /FROM 20 TO 30 MPH/ DURING THE AFTERNOON WILL PERSIST INTO THE EVENING AS THE POST-FRONTAL PRESSURE GRADIENT STRENGTHENS. DESPITE COOLING TEMPERATURES WITH WINDS VEERING TO THE N/NW...CONSENSUS OF MODEL FORECASTS SUGGESTS RH RECOVERY WILL INITIALLY BE POOR DURING THE EARLY EVENING AS GUSTS AOA 30 MPH CONTINUE. ALTHOUGH MIN RH VALUES MAY BE MARGINAL /AROUND 15 PERCENT/...THE STRENGTH AND DURATION OF WINDS WARRANT A CRITICAL DELINEATION. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... MARGINAL TO LOCALIZED CRITICAL CONDITIONS MAY DEVELOP AROUND PEAK HEATING ON SUN. THE STRONGEST LOW-LEVEL SLYS SHOULD PRIMARILY BE CONFINED E OF A DRYLINE MIXING ACROSS THE CNTRL/SRN PLAINS...WHERE RH VALUES WILL BE INCREASINGLY MARGINAL WITH ERN EXTENT. HOWEVER...AS LEE CYCLOGENESIS ENSUES INVOF NERN CO...A TIGHTENING SURFACE PRESSURE GRADIENT W OF THE DRYLINE WILL OCCUR ACROSS THE TX/OX PANHANDLES DURING MID TO LATE AFTERNOON. SUSTAINED SURFACE WINDS SHOULD REACH 15 TO 20 MPH WITH RH VALUES OF 10 TO 20 PERCENT. ...NRN SACRAMENTO VALLEY IN NRN CA... A HIGHLY LOCALIZED ENHANCED FIRE WEATHER THREAT SHOULD DEVELOP LATE SUN AFTERNOON THROUGH THE EVENING. GUSTY NLY WINDS WILL DEVELOP AS LOW-LEVEL PRESSURE GRADIENTS TIGHTEN SUBSTANTIALLY WITH A RIDGE BUILDING INTO THE PACIFIC NW. SUSTAINED SURFACE WINDS SHOULD BECOME MODERATE...REACHING 15 MPH. THIS WOULD BE INITIALLY JUXTAPOSED WITH LOW RH VALUES OF 6 TO 12 PERCENT...AND POOR RH RECOVERY IS EXPECTED THROUGH MUCH OF THE NIGHT. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... LATEST MODEL GUIDANCE CONTINUES TO INDICATE A STRONG UPPER JET STREAK /100-120 KT AT 250 MB/ MOVING ACROSS THE NRN GREAT BASIN DURING SUNDAY AFTERNOON...WHICH WILL SUPPORT THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS /SUSTAINED WIND SPEEDS AOA 25 MPH FOR MANY LOCATIONS WITH RH VALUES BELOW 15 PERCENT/ ACROSS MOST OF THE ERN GREAT BASIN INTO PORTIONS OF THE CNTRL ROCKIES. STRONG POST FRONTAL SURFACE WIND SPEEDS /20-30 MPH/ ARE ALSO INDICATED OVER S-CNTRL/SERN ID INTO PORTIONS OF NWRN UT AND NERN NV...WHICH WILL SUPPORT CRITICAL CONDITIONS AS WELL...DESPITE THE PRESENCE OF SLIGHTLY MORE MARGINAL RH VALUES. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... LOW-LEVEL CYCLOGENESIS OVER THE CNTRL HIGH PLAINS WILL AID IN THE DEVELOPMENT OF A 30-40 KT S-SWLY LOW-LEVEL JET DURING THE MID TO LATE AFTERNOON...WHILE A HOT/STEEP LAPSE RATE AIR MASS SPREADS EWD ACROSS THE TX/OK PANHANDLES AND SWRN KS. THOUGH A ZONE OF CRITICALLY LOW RH SHOULD BE FAVORABLY JUXTAPOSED WITH CRITICALLY STRONG WIND SPEEDS DURING SUNDAY AFTERNOON...UNCERTAINTY EXISTS ON WHERE A LOW-LEVEL TROUGH AXIS WILL SET UP /WHICH WILL INFLUENCE WHERE THE LOW RH/STRONG WIND OVERLAP WILL BE LOCATED/. THEREFORE...WILL WAIT TO ISSUE A CRITICAL OUTLOOK AREA UNTIL GREATER CONFIDENCE IN THIS SCENARIO DEVELOPS. ...NRN SACRAMENTO VALLEY IN NRN CA... NO CHANGES MADE TO THE PREVIOUS FORECAST. ...SRN CA DESERTS... NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING OVER THE DESERTS OF SRN CA AS ONSHORE FLOW REGIME STRENGTHENS IN RESPONSE TO INCREASING PRESSURE GRADIENT...LEADING TO SUSTAINED WIND SPEEDS OF 20 MPH OCCURRING IN THE MIDST OF RH VALUES NEAR 5 PERCENT. ...MID-ATLANTIC REGION /NJ INTO NRN-ERN VA/... LATEST MODEL GUIDANCE INDICATES AFTERNOON RH VALUES MAY BRIEFLY DROP BELOW 30 PERCENT ON SUNDAY. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN AOB 10 MPH...WHICH WILL PRECLUDE A MORE SIGNIFICANT FIRE WEATHER THREAT. ..GARNER.. 09/04/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT SAT SEP 04 2010/ ...SYNOPSIS... A LARGE-SCALE UPPER-LEVEL TROUGH WILL CONTINUE TO DIG ACROSS THE NWRN CONUS AND PROGRESS EWD TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY MON. MID-LEVEL WLYS WILL STRENGTHEN WITH A BELT OF 50 TO 70 MPH FLOW AT 500 MB CENTERED ACROSS NRN NV/SRN ID INTO WY ON SUN AFTERNOON. AT THE SURFACE...A SHARP COLD FRONT WILL SWEEP SWD THROUGH THE GREAT BASIN...WITH TIGHT THERMAL AND PRESSURE GRADIENTS DEVELOPING IN ITS WAKE. ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... WIDESPREAD CRITICAL CONDITIONS APPEAR LIKELY SUN AFTERNOON AHEAD OF A SHARP COLD FRONT ACROSS NRN AZ...SRN/ERN UT...NRN/WRN CO AND CNTRL/SRN WY. SUSTAINED SURFACE WINDS WILL INCREASE TO 20 TO 30 MPH...WITH WIND GUSTS LOCALLY REACHING 40 TO 50 MPH OVER PORTIONS OF SRN WY/NWRN CO. THIS WILL COINCIDE WITH AN ANTECEDENT VERY WARM/DRY AIR MASS /RH VALUES OF 5 TO 15 PERCENT/. THE CRITICAL AREA HAS BEEN EXTENDED FARTHER NW INTO NERN NV/NWRN UT/SERN ID. HERE...STRONG SURFACE WINDS /FROM 20 TO 30 MPH/ DURING THE AFTERNOON WILL PERSIST INTO THE EVENING AS THE POST-FRONTAL PRESSURE GRADIENT STRENGTHENS. DESPITE COOLING TEMPERATURES WITH WINDS VEERING TO THE N/NW...CONSENSUS OF MODEL FORECASTS SUGGESTS RH RECOVERY WILL INITIALLY BE POOR DURING THE EARLY EVENING AS GUSTS AOA 30 MPH CONTINUE. ALTHOUGH MIN RH VALUES MAY BE MARGINAL /AROUND 15 PERCENT/...THE STRENGTH AND DURATION OF WINDS WARRANT A CRITICAL DELINEATION. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... MARGINAL TO LOCALIZED CRITICAL CONDITIONS MAY DEVELOP AROUND PEAK HEATING ON SUN. THE STRONGEST LOW-LEVEL SLYS SHOULD PRIMARILY BE CONFINED E OF A DRYLINE MIXING ACROSS THE CNTRL/SRN PLAINS...WHERE RH VALUES WILL BE INCREASINGLY MARGINAL WITH ERN EXTENT. HOWEVER...AS LEE CYCLOGENESIS ENSUES INVOF NERN CO...A TIGHTENING SURFACE PRESSURE GRADIENT W OF THE DRYLINE WILL OCCUR ACROSS THE TX/OX PANHANDLES DURING MID TO LATE AFTERNOON. SUSTAINED SURFACE WINDS SHOULD REACH 15 TO 20 MPH WITH RH VALUES OF 10 TO 20 PERCENT. ...NRN SACRAMENTO VALLEY IN NRN CA... A HIGHLY LOCALIZED ENHANCED FIRE WEATHER THREAT SHOULD DEVELOP LATE SUN AFTERNOON THROUGH THE EVENING. GUSTY NLY WINDS WILL DEVELOP AS LOW-LEVEL PRESSURE GRADIENTS TIGHTEN SUBSTANTIALLY WITH A RIDGE BUILDING INTO THE PACIFIC NW. SUSTAINED SURFACE WINDS SHOULD BECOME MODERATE...REACHING 15 MPH. THIS WOULD BE INITIALLY JUXTAPOSED WITH LOW RH VALUES OF 6 TO 12 PERCENT...AND POOR RH RECOVERY IS EXPECTED THROUGH MUCH OF THE NIGHT. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... LATEST MODEL GUIDANCE CONTINUES TO INDICATE A STRONG UPPER JET STREAK /100-120 KT AT 250 MB/ MOVING ACROSS THE NRN GREAT BASIN DURING SUNDAY AFTERNOON...WHICH WILL SUPPORT THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS /SUSTAINED WIND SPEEDS AOA 25 MPH FOR MANY LOCATIONS WITH RH VALUES BELOW 15 PERCENT/ ACROSS MOST OF THE ERN GREAT BASIN INTO PORTIONS OF THE CNTRL ROCKIES. STRONG POST FRONTAL SURFACE WIND SPEEDS /20-30 MPH/ ARE ALSO INDICATED OVER S-CNTRL/SERN ID INTO PORTIONS OF NWRN UT AND NERN NV...WHICH WILL SUPPORT CRITICAL CONDITIONS AS WELL...DESPITE THE PRESENCE OF SLIGHTLY MORE MARGINAL RH VALUES. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... LOW-LEVEL CYCLOGENESIS OVER THE CNTRL HIGH PLAINS WILL AID IN THE DEVELOPMENT OF A 30-40 KT S-SWLY LOW-LEVEL JET DURING THE MID TO LATE AFTERNOON...WHILE A HOT/STEEP LAPSE RATE AIR MASS SPREADS EWD ACROSS THE TX/OK PANHANDLES AND SWRN KS. THOUGH A ZONE OF CRITICALLY LOW RH SHOULD BE FAVORABLY JUXTAPOSED WITH CRITICALLY STRONG WIND SPEEDS DURING SUNDAY AFTERNOON...UNCERTAINTY EXISTS ON WHERE A LOW-LEVEL TROUGH AXIS WILL SET UP /WHICH WILL INFLUENCE WHERE THE LOW RH/STRONG WIND OVERLAP WILL BE LOCATED/. THEREFORE...WILL WAIT TO ISSUE A CRITICAL OUTLOOK AREA UNTIL GREATER CONFIDENCE IN THIS SCENARIO DEVELOPS. ...NRN SACRAMENTO VALLEY IN NRN CA... NO CHANGES MADE TO THE PREVIOUS FORECAST. ...SRN CA DESERTS... NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING OVER THE DESERTS OF SRN CA AS ONSHORE FLOW REGIME STRENGTHENS IN RESPONSE TO INCREASING PRESSURE GRADIENT...LEADING TO SUSTAINED WIND SPEEDS OF 20 MPH OCCURRING IN THE MIDST OF RH VALUES NEAR 5 PERCENT. ...MID-ATLANTIC REGION /NJ INTO NRN-ERN VA/... LATEST MODEL GUIDANCE INDICATES AFTERNOON RH VALUES MAY BRIEFLY DROP BELOW 30 PERCENT ON SUNDAY. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN AOB 10 MPH...WHICH WILL PRECLUDE A MORE SIGNIFICANT FIRE WEATHER THREAT. ..GARNER.. 09/04/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT SAT SEP 04 2010/ ...SYNOPSIS... A LARGE-SCALE UPPER-LEVEL TROUGH WILL CONTINUE TO DIG ACROSS THE NWRN CONUS AND PROGRESS EWD TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY MON. MID-LEVEL WLYS WILL STRENGTHEN WITH A BELT OF 50 TO 70 MPH FLOW AT 500 MB CENTERED ACROSS NRN NV/SRN ID INTO WY ON SUN AFTERNOON. AT THE SURFACE...A SHARP COLD FRONT WILL SWEEP SWD THROUGH THE GREAT BASIN...WITH TIGHT THERMAL AND PRESSURE GRADIENTS DEVELOPING IN ITS WAKE. ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... WIDESPREAD CRITICAL CONDITIONS APPEAR LIKELY SUN AFTERNOON AHEAD OF A SHARP COLD FRONT ACROSS NRN AZ...SRN/ERN UT...NRN/WRN CO AND CNTRL/SRN WY. SUSTAINED SURFACE WINDS WILL INCREASE TO 20 TO 30 MPH...WITH WIND GUSTS LOCALLY REACHING 40 TO 50 MPH OVER PORTIONS OF SRN WY/NWRN CO. THIS WILL COINCIDE WITH AN ANTECEDENT VERY WARM/DRY AIR MASS /RH VALUES OF 5 TO 15 PERCENT/. THE CRITICAL AREA HAS BEEN EXTENDED FARTHER NW INTO NERN NV/NWRN UT/SERN ID. HERE...STRONG SURFACE WINDS /FROM 20 TO 30 MPH/ DURING THE AFTERNOON WILL PERSIST INTO THE EVENING AS THE POST-FRONTAL PRESSURE GRADIENT STRENGTHENS. DESPITE COOLING TEMPERATURES WITH WINDS VEERING TO THE N/NW...CONSENSUS OF MODEL FORECASTS SUGGESTS RH RECOVERY WILL INITIALLY BE POOR DURING THE EARLY EVENING AS GUSTS AOA 30 MPH CONTINUE. ALTHOUGH MIN RH VALUES MAY BE MARGINAL /AROUND 15 PERCENT/...THE STRENGTH AND DURATION OF WINDS WARRANT A CRITICAL DELINEATION. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... MARGINAL TO LOCALIZED CRITICAL CONDITIONS MAY DEVELOP AROUND PEAK HEATING ON SUN. THE STRONGEST LOW-LEVEL SLYS SHOULD PRIMARILY BE CONFINED E OF A DRYLINE MIXING ACROSS THE CNTRL/SRN PLAINS...WHERE RH VALUES WILL BE INCREASINGLY MARGINAL WITH ERN EXTENT. HOWEVER...AS LEE CYCLOGENESIS ENSUES INVOF NERN CO...A TIGHTENING SURFACE PRESSURE GRADIENT W OF THE DRYLINE WILL OCCUR ACROSS THE TX/OX PANHANDLES DURING MID TO LATE AFTERNOON. SUSTAINED SURFACE WINDS SHOULD REACH 15 TO 20 MPH WITH RH VALUES OF 10 TO 20 PERCENT. ...NRN SACRAMENTO VALLEY IN NRN CA... A HIGHLY LOCALIZED ENHANCED FIRE WEATHER THREAT SHOULD DEVELOP LATE SUN AFTERNOON THROUGH THE EVENING. GUSTY NLY WINDS WILL DEVELOP AS LOW-LEVEL PRESSURE GRADIENTS TIGHTEN SUBSTANTIALLY WITH A RIDGE BUILDING INTO THE PACIFIC NW. SUSTAINED SURFACE WINDS SHOULD BECOME MODERATE...REACHING 15 MPH. THIS WOULD BE INITIALLY JUXTAPOSED WITH LOW RH VALUES OF 6 TO 12 PERCENT...AND POOR RH RECOVERY IS EXPECTED THROUGH MUCH OF THE NIGHT. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... LATEST MODEL GUIDANCE CONTINUES TO INDICATE A STRONG UPPER JET STREAK /100-120 KT AT 250 MB/ MOVING ACROSS THE NRN GREAT BASIN DURING SUNDAY AFTERNOON...WHICH WILL SUPPORT THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS /SUSTAINED WIND SPEEDS AOA 25 MPH FOR MANY LOCATIONS WITH RH VALUES BELOW 15 PERCENT/ ACROSS MOST OF THE ERN GREAT BASIN INTO PORTIONS OF THE CNTRL ROCKIES. STRONG POST FRONTAL SURFACE WIND SPEEDS /20-30 MPH/ ARE ALSO INDICATED OVER S-CNTRL/SERN ID INTO PORTIONS OF NWRN UT AND NERN NV...WHICH WILL SUPPORT CRITICAL CONDITIONS AS WELL...DESPITE THE PRESENCE OF SLIGHTLY MORE MARGINAL RH VALUES. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... LOW-LEVEL CYCLOGENESIS OVER THE CNTRL HIGH PLAINS WILL AID IN THE DEVELOPMENT OF A 30-40 KT S-SWLY LOW-LEVEL JET DURING THE MID TO LATE AFTERNOON...WHILE A HOT/STEEP LAPSE RATE AIR MASS SPREADS EWD ACROSS THE TX/OK PANHANDLES AND SWRN KS. THOUGH A ZONE OF CRITICALLY LOW RH SHOULD BE FAVORABLY JUXTAPOSED WITH CRITICALLY STRONG WIND SPEEDS DURING SUNDAY AFTERNOON...UNCERTAINTY EXISTS ON WHERE A LOW-LEVEL TROUGH AXIS WILL SET UP /WHICH WILL INFLUENCE WHERE THE LOW RH/STRONG WIND OVERLAP WILL BE LOCATED/. THEREFORE...WILL WAIT TO ISSUE A CRITICAL OUTLOOK AREA UNTIL GREATER CONFIDENCE IN THIS SCENARIO DEVELOPS. ...NRN SACRAMENTO VALLEY IN NRN CA... NO CHANGES MADE TO THE PREVIOUS FORECAST. ...SRN CA DESERTS... NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING OVER THE DESERTS OF SRN CA AS ONSHORE FLOW REGIME STRENGTHENS IN RESPONSE TO INCREASING PRESSURE GRADIENT...LEADING TO SUSTAINED WIND SPEEDS OF 20 MPH OCCURRING IN THE MIDST OF RH VALUES NEAR 5 PERCENT. ...MID-ATLANTIC REGION /NJ INTO NRN-ERN VA/... LATEST MODEL GUIDANCE INDICATES AFTERNOON RH VALUES MAY BRIEFLY DROP BELOW 30 PERCENT ON SUNDAY. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN AOB 10 MPH...WHICH WILL PRECLUDE A MORE SIGNIFICANT FIRE WEATHER THREAT. ..GARNER.. 09/04/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT SAT SEP 04 2010/ ...SYNOPSIS... A LARGE-SCALE UPPER-LEVEL TROUGH WILL CONTINUE TO DIG ACROSS THE NWRN CONUS AND PROGRESS EWD TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY MON. MID-LEVEL WLYS WILL STRENGTHEN WITH A BELT OF 50 TO 70 MPH FLOW AT 500 MB CENTERED ACROSS NRN NV/SRN ID INTO WY ON SUN AFTERNOON. AT THE SURFACE...A SHARP COLD FRONT WILL SWEEP SWD THROUGH THE GREAT BASIN...WITH TIGHT THERMAL AND PRESSURE GRADIENTS DEVELOPING IN ITS WAKE. ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... WIDESPREAD CRITICAL CONDITIONS APPEAR LIKELY SUN AFTERNOON AHEAD OF A SHARP COLD FRONT ACROSS NRN AZ...SRN/ERN UT...NRN/WRN CO AND CNTRL/SRN WY. SUSTAINED SURFACE WINDS WILL INCREASE TO 20 TO 30 MPH...WITH WIND GUSTS LOCALLY REACHING 40 TO 50 MPH OVER PORTIONS OF SRN WY/NWRN CO. THIS WILL COINCIDE WITH AN ANTECEDENT VERY WARM/DRY AIR MASS /RH VALUES OF 5 TO 15 PERCENT/. THE CRITICAL AREA HAS BEEN EXTENDED FARTHER NW INTO NERN NV/NWRN UT/SERN ID. HERE...STRONG SURFACE WINDS /FROM 20 TO 30 MPH/ DURING THE AFTERNOON WILL PERSIST INTO THE EVENING AS THE POST-FRONTAL PRESSURE GRADIENT STRENGTHENS. DESPITE COOLING TEMPERATURES WITH WINDS VEERING TO THE N/NW...CONSENSUS OF MODEL FORECASTS SUGGESTS RH RECOVERY WILL INITIALLY BE POOR DURING THE EARLY EVENING AS GUSTS AOA 30 MPH CONTINUE. ALTHOUGH MIN RH VALUES MAY BE MARGINAL /AROUND 15 PERCENT/...THE STRENGTH AND DURATION OF WINDS WARRANT A CRITICAL DELINEATION. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... MARGINAL TO LOCALIZED CRITICAL CONDITIONS MAY DEVELOP AROUND PEAK HEATING ON SUN. THE STRONGEST LOW-LEVEL SLYS SHOULD PRIMARILY BE CONFINED E OF A DRYLINE MIXING ACROSS THE CNTRL/SRN PLAINS...WHERE RH VALUES WILL BE INCREASINGLY MARGINAL WITH ERN EXTENT. HOWEVER...AS LEE CYCLOGENESIS ENSUES INVOF NERN CO...A TIGHTENING SURFACE PRESSURE GRADIENT W OF THE DRYLINE WILL OCCUR ACROSS THE TX/OX PANHANDLES DURING MID TO LATE AFTERNOON. SUSTAINED SURFACE WINDS SHOULD REACH 15 TO 20 MPH WITH RH VALUES OF 10 TO 20 PERCENT. ...NRN SACRAMENTO VALLEY IN NRN CA... A HIGHLY LOCALIZED ENHANCED FIRE WEATHER THREAT SHOULD DEVELOP LATE SUN AFTERNOON THROUGH THE EVENING. GUSTY NLY WINDS WILL DEVELOP AS LOW-LEVEL PRESSURE GRADIENTS TIGHTEN SUBSTANTIALLY WITH A RIDGE BUILDING INTO THE PACIFIC NW. SUSTAINED SURFACE WINDS SHOULD BECOME MODERATE...REACHING 15 MPH. THIS WOULD BE INITIALLY JUXTAPOSED WITH LOW RH VALUES OF 6 TO 12 PERCENT...AND POOR RH RECOVERY IS EXPECTED THROUGH MUCH OF THE NIGHT. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1159 AM CDT SAT SEP 04 2010 VALID 051200Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... LATEST MODEL GUIDANCE CONTINUES TO INDICATE A STRONG UPPER JET STREAK /100-120 KT AT 250 MB/ MOVING ACROSS THE NRN GREAT BASIN DURING SUNDAY AFTERNOON...WHICH WILL SUPPORT THE POTENTIAL FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS /SUSTAINED WIND SPEEDS AOA 25 MPH FOR MANY LOCATIONS WITH RH VALUES BELOW 15 PERCENT/ ACROSS MOST OF THE ERN GREAT BASIN INTO PORTIONS OF THE CNTRL ROCKIES. STRONG POST FRONTAL SURFACE WIND SPEEDS /20-30 MPH/ ARE ALSO INDICATED OVER S-CNTRL/SERN ID INTO PORTIONS OF NWRN UT AND NERN NV...WHICH WILL SUPPORT CRITICAL CONDITIONS AS WELL...DESPITE THE PRESENCE OF SLIGHTLY MORE MARGINAL RH VALUES. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... LOW-LEVEL CYCLOGENESIS OVER THE CNTRL HIGH PLAINS WILL AID IN THE DEVELOPMENT OF A 30-40 KT S-SWLY LOW-LEVEL JET DURING THE MID TO LATE AFTERNOON...WHILE A HOT/STEEP LAPSE RATE AIR MASS SPREADS EWD ACROSS THE TX/OK PANHANDLES AND SWRN KS. THOUGH A ZONE OF CRITICALLY LOW RH SHOULD BE FAVORABLY JUXTAPOSED WITH CRITICALLY STRONG WIND SPEEDS DURING SUNDAY AFTERNOON...UNCERTAINTY EXISTS ON WHERE A LOW-LEVEL TROUGH AXIS WILL SET UP /WHICH WILL INFLUENCE WHERE THE LOW RH/STRONG WIND OVERLAP WILL BE LOCATED/. THEREFORE...WILL WAIT TO ISSUE A CRITICAL OUTLOOK AREA UNTIL GREATER CONFIDENCE IN THIS SCENARIO DEVELOPS. ...NRN SACRAMENTO VALLEY IN NRN CA... NO CHANGES MADE TO THE PREVIOUS FORECAST. ...SRN CA DESERTS... NEAR TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE LATE AFTERNOON/EVENING OVER THE DESERTS OF SRN CA AS ONSHORE FLOW REGIME STRENGTHENS IN RESPONSE TO INCREASING PRESSURE GRADIENT...LEADING TO SUSTAINED WIND SPEEDS OF 20 MPH OCCURRING IN THE MIDST OF RH VALUES NEAR 5 PERCENT. ...MID-ATLANTIC REGION /NJ INTO NRN-ERN VA/... LATEST MODEL GUIDANCE INDICATES AFTERNOON RH VALUES MAY BRIEFLY DROP BELOW 30 PERCENT ON SUNDAY. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN AOB 10 MPH...WHICH WILL PRECLUDE A MORE SIGNIFICANT FIRE WEATHER THREAT. ..GARNER.. 09/04/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT SAT SEP 04 2010/ ...SYNOPSIS... A LARGE-SCALE UPPER-LEVEL TROUGH WILL CONTINUE TO DIG ACROSS THE NWRN CONUS AND PROGRESS EWD TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY MON. MID-LEVEL WLYS WILL STRENGTHEN WITH A BELT OF 50 TO 70 MPH FLOW AT 500 MB CENTERED ACROSS NRN NV/SRN ID INTO WY ON SUN AFTERNOON. AT THE SURFACE...A SHARP COLD FRONT WILL SWEEP SWD THROUGH THE GREAT BASIN...WITH TIGHT THERMAL AND PRESSURE GRADIENTS DEVELOPING IN ITS WAKE. ...MOST OF THE ERN GREAT BASIN TO THE CNTRL ROCKIES... WIDESPREAD CRITICAL CONDITIONS APPEAR LIKELY SUN AFTERNOON AHEAD OF A SHARP COLD FRONT ACROSS NRN AZ...SRN/ERN UT...NRN/WRN CO AND CNTRL/SRN WY. SUSTAINED SURFACE WINDS WILL INCREASE TO 20 TO 30 MPH...WITH WIND GUSTS LOCALLY REACHING 40 TO 50 MPH OVER PORTIONS OF SRN WY/NWRN CO. THIS WILL COINCIDE WITH AN ANTECEDENT VERY WARM/DRY AIR MASS /RH VALUES OF 5 TO 15 PERCENT/. THE CRITICAL AREA HAS BEEN EXTENDED FARTHER NW INTO NERN NV/NWRN UT/SERN ID. HERE...STRONG SURFACE WINDS /FROM 20 TO 30 MPH/ DURING THE AFTERNOON WILL PERSIST INTO THE EVENING AS THE POST-FRONTAL PRESSURE GRADIENT STRENGTHENS. DESPITE COOLING TEMPERATURES WITH WINDS VEERING TO THE N/NW...CONSENSUS OF MODEL FORECASTS SUGGESTS RH RECOVERY WILL INITIALLY BE POOR DURING THE EARLY EVENING AS GUSTS AOA 30 MPH CONTINUE. ALTHOUGH MIN RH VALUES MAY BE MARGINAL /AROUND 15 PERCENT/...THE STRENGTH AND DURATION OF WINDS WARRANT A CRITICAL DELINEATION. ...PORTIONS OF THE TX/OK PANHANDLES...SWRN KS...NWRN OK... MARGINAL TO LOCALIZED CRITICAL CONDITIONS MAY DEVELOP AROUND PEAK HEATING ON SUN. THE STRONGEST LOW-LEVEL SLYS SHOULD PRIMARILY BE CONFINED E OF A DRYLINE MIXING ACROSS THE CNTRL/SRN PLAINS...WHERE RH VALUES WILL BE INCREASINGLY MARGINAL WITH ERN EXTENT. HOWEVER...AS LEE CYCLOGENESIS ENSUES INVOF NERN CO...A TIGHTENING SURFACE PRESSURE GRADIENT W OF THE DRYLINE WILL OCCUR ACROSS THE TX/OX PANHANDLES DURING MID TO LATE AFTERNOON. SUSTAINED SURFACE WINDS SHOULD REACH 15 TO 20 MPH WITH RH VALUES OF 10 TO 20 PERCENT. ...NRN SACRAMENTO VALLEY IN NRN CA... A HIGHLY LOCALIZED ENHANCED FIRE WEATHER THREAT SHOULD DEVELOP LATE SUN AFTERNOON THROUGH THE EVENING. GUSTY NLY WINDS WILL DEVELOP AS LOW-LEVEL PRESSURE GRADIENTS TIGHTEN SUBSTANTIALLY WITH A RIDGE BUILDING INTO THE PACIFIC NW. SUSTAINED SURFACE WINDS SHOULD BECOME MODERATE...REACHING 15 MPH. THIS WOULD BE INITIALLY JUXTAPOSED WITH LOW RH VALUES OF 6 TO 12 PERCENT...AND POOR RH RECOVERY IS EXPECTED THROUGH MUCH OF THE NIGHT. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more