Storm Prediction Center
Day 1 and Day 2 Fire Weather Outlooks

Day 1 Fire Weather Forecast graphic

Click for Day 1 FireWX Areal Outline Product

   ZCZC SPCFWDDY1 ALL
   FNUS21 KWNS 081635
   
   DAY 1 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 AM CDT WED SEP 08 2010
   
   VALID 081700Z - 091200Z
   
   ...CRITICAL FIRE WEATHER AREA FOR ERN/SRN NV...WRN UT...NWRN AZ...
   ...CRITICAL FIRE WEATHER AREA FOR SERN PA...SRN NJ...NRN DE...MOST
   OF MD...D.C...ERN WV PANHANDLE...NRN VA...
   
   ...ERN/SRN NV...WRN UT...NWRN AZ...
   WV IMAGERY DEPICTS A SHORTWAVE TROUGH LOCATED OFF THE COAST OF CA
   THIS MORNING. AS IT PIVOTS EWD TOWARD THE W COAST...MID-LEVEL SWLY
   FLOW IS FORECAST TO INCREASE IN STRENGTH ACROSS THE GREAT BASIN
   /AROUND 50 KT AT 500 MB...30 KT AT 700 MB/. DESPITE THIS
   STRENGTHENING UPPER FLOW REGIME...LATEST NAM MODEL GUIDANCE HAS
   TRENDED SLIGHTLY WEAKER WITH THE MAGNITUDE OF CRITICAL FIRE WEATHER
   INGREDIENTS...SHOWING MAX SUSTAINED WINDS OF 20 TO PERHAPS 25 MPH
   /WITH GUSTS UP TO 30 MPH...PARTICULARLY OVER E-CNTRL NV AND W-CNTRL
   UT/ AND MIN RH VALUES AROUND 15 PERCENT /WHICH WILL HAVE TO DROP
   SUBSTANTIALLY GIVEN GENERALLY MOIST RH VALUES OBSERVED THIS
   MORNING/. THE PREVIOUS OUTLOOK AREA ENCOMPASSES THE REGION OF
   HIGHEST CRITICAL FIRE WEATHER POTENTIAL...SO NO CHANGES HAVE BEEN
   MADE.
   
   ...SERN PA...SRN NJ...NRN DE...MOST OF MD...D.C...ERN WV
   PANHANDLE...NRN VA...
   AT 16Z...A COLD FRONT WAS IN THE PROCESS OF MOVING OFF THE JERSEY
   SHORE...AND THEN TRAILED SWWD ACROSS VA...WHERE IT IS FORECAST TO
   GRADUALLY SHIFT S-SEWD THROUGH THE AFTERNOON. TEMPERATURES ARE
   WARMING INTO THE 80S F BEHIND THE FRONT...AND A NOTABLE DRYING TREND
   IN SURFACE DEWPOINTS IS ALSO OBSERVED...WHICH WILL SUPPORT MIN RH
   VALUES IN THE 20S BY EARLY AFTERNOON. AREA RAOBS AT 12Z INDICATE
   STRONG LOW/MID-LEVEL WLY FLOW ACCOMPANYING A SHORTWAVE TROUGH THAT
   IS MOVING EWD ACROSS THE CNTRL APPALACHIANS AND TOWARD THE MID
   ATLANTIC...WHICH WILL FAVOR POST FRONTAL SURFACE WIND SPEEDS AOA 15
   MPH. THESE CONDITIONS SUPPORT THE CRITICAL AREA ASSIGNED TO THE
   REGION...AND NO SUBSTANTIAL CHANGES HAVE BEEN MADE TO THE PREVIOUS
   FORECAST.
   
   ..GARNER.. 09/08/2010
   
   .PREV DISCUSSION... /ISSUED 0313 AM CDT WED SEP 08 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 LATE 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 ACROSS SRN QUEBEC AND NEW ENGLAND.
   ASSOCIATED SURFACE COLD FRONT WILL PUSH EAST OF THE NRN/CNTRL
   APPALACHIANS THIS MORNING REACHING THE MID-ATLANTIC COAST DURING THE
   EARLY/MID-AFTERNOON.
   
   ...ERN/SRN NV...WRN UT...NWRN AZ...
   A BROAD SWATH OF MODERATELY STRONG LOW/MID-LEVEL S/SWLYS WILL
   ENVELOP MUCH OF THE CNTRL/SRN GREAT BASIN BY THIS AFTERNOON. THIS
   WILL BE COINCIDENT WITH A ZONE OF LOWER RH VALUES DEVELOPING BETWEEN
   A COLD FRONT PUSHING ACROSS WRN NV AND A PLUME OF RICHER
   SUB-TROPICAL MOISTURE BECOME SHUNTED EWD TOWARDS THE FOUR CORNERS.
   LATEST MODEL FORECASTS ARE FAIRLY CONSISTENT WITH THE DEPICTION OF
   WIDESPREAD SUSTAINED SURFACE WINDS AROUND 20 TO 25 MPH AND GUSTS OF
   30 TO 40 MPH...JUXTAPOSED WITH RH VALUES OF 10 TO 15 PERCENT. THE
   OVERALL THREAT SHOULD BE TEMPERED IN SOME AREAS ACROSS FAR SRN
   NV/SWRN UT/NWRN AZ WHERE LIGHT RAINFALL CONTRIBUTED TO HIGHER FUEL
   MOISTURE ON TUE.
   
   ...SERN PA...SRN NJ...NRN DE...MOST OF MD...D.C...ERN WV
   PANHANDLE...NRN VA...
   SUBSTANTIAL DRYING WILL OCCUR IN THE WAKE OF A COLD FRONT PASSAGE
   THIS MORNING. 06Z NAM/00Z GFS FORECASTS ARE CONSISTENT WITH THE
   DEPICTION OF RH VALUES FALLING INTO THE UPPER TEENS AND 20S BY PEAK
   HEATING AS TEMPERATURES HOLD SLIGHTLY ABOVE NORMAL IN THE 80S. MODEL
   FORECAST SOUNDINGS SUGGEST STRONG WLYS AT THE TOP OF A WELL-MIXED
   BOUNDARY LAYER WOULD SUPPORT SUSTAINED SURFACE WINDS FROM 15 TO 20
   MPH AND POTENTIAL FOR FREQUENT GUSTS OF 25 TO 35 MPH. GIVEN THAT
   LITTLE TO NO RAIN HAS FALLEN OVER THE PAST TWO WEEKS AND AREAS OF
   MODERATE TO SEVERE DROUGHT PERSIST...A CRITICAL AREA DELINEATION
   APPEARS WARRANTED.
   
   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
   
      
Day 2 Fire Weather Forecast graphic

Click for Day 2 FireWX Areal Outline Product

   ZCZC SPCFWDDY2 ALL
   FNUS22 KWNS 081837
   
   DAY 2 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0137 PM CDT WED SEP 08 2010
   
   VALID 091200Z - 101200Z
   
   ...CRITICAL FIRE WEATHER AREA FOR CNTRL/NERN WY...FAR NWRN CO...ERN
   UT...FAR NERN AZ...
   
   ...CNTRL/NERN WY...FAR NWRN CO...ERN UT...FAR NERN AZ...
   NO CHANGES MADE TO THE PREVIOUS FORECAST.
   
   ...LEE OF THE ROCKIES IN N-CNTRL CO...
   LATEST NAM FORECAST SOUNDINGS INDICATE THAT STRONG /40 KT AT 1 KM
   AGL/ DOWNSLOPE WINDS WILL DEVELOP IMMEDIATELY UPSTREAM OF BOULDER
   ALONG THE LEE OF THE ROCKIES/ADJACENT FOOTHILLS BETWEEN 00-12Z
   FRIDAY /I.E. LATE IN THE D2 PERIOD/. IN ADDITION TO THE POTENTIAL
   FOR RAPID FIRE SPREAD...DOWNSLOPE WINDS WOULD PROMOTE WARMING
   TEMPERATURES AND LOWERING RH VALUES...WHICH COULD AGGRAVATE CONTROL
   EFFORTS ASSOCIATED WITH THE FOUR MILE CANYON WILDFIRE. ATTM...IT IS
   UNCERTAIN WHETHER THE MAGNITUDE OF NAM FORECAST WIND SPEEDS WILL
   MATERIALIZE...SO WILL DEFER AN UPGRADE TO CRITICAL FOR THE NEXT D1
   OUTLOOK.
   
   ...MD...DE...NRN VA...D.C....
   NO CHANGES MADE TO THE PREVIOUS FORECAST.
   
   ..GARNER.. 09/08/2010
   
   .PREV DISCUSSION... /ISSUED 0457 AM CDT WED SEP 08 2010/
   
   ...SYNOPSIS...
   AN UPPER-LEVEL TROUGH WILL PROGRESS E/NEWD ACROSS THE GREAT BASIN
   TOWARDS THE NRN/CNTRL ROCKIES THROUGH EARLY FRI. LEE CYCLOGENESIS
   WILL OCCUR ACROSS NRN HIGH PLAINS...WITH AN ATTENDANT COLD FRONT
   DRAPED SWWD THROUGH THE ERN GREAT BASIN ON THU AFTERNOON. IN THE
   EAST...AN UPPER-LEVEL LOW WILL REMAIN ANCHORED OVER NRN NEW ENGLAND.
   
   ...CNTRL/NERN WY...FAR NWRN CO...ERN UT...FAR NERN AZ...
   A BELT OF RATHER STRONG MID-LEVEL SWLYS /60 TO 75 MPH AT 500 MB/
   WILL OVERSPREAD THE ERN GREAT BASIN AND CNTRL ROCKIES BY THU
   AFTERNOON IN ASSOCIATION WITH THE WRN CONUS UPPER-LEVEL TROUGH. DEEP
   VERTICAL MIXING SHOULD OCCUR WITHIN A RELATIVELY NARROW CORRIDOR
   BETWEEN A COLD FRONT SHIFTING E THROUGH THE ERN GREAT BASIN AND A
   PLUME OF RICHER SUB-TROPICAL MOISTURE BEING SHUNTED EWD ACROSS THE
   CNTRL/SRN ROCKIES. THIS MIXING SHOULD LEAD TO SUSTAINED SURFACE
   WINDS OF 20 TO 30 MPH BECOMING WIDESPREAD FROM NERN AZ THROUGH
   CNTRL/NERN WY. THE PRIMARY UNCERTAINTY REVOLVES AROUND THE
   DEVELOPMENT OF LOW RH...AS MODEL FORECASTS VARY WITH BOTH MAGNITUDE
   AND SPATIAL EXTENT. CONSENSUS OF MODEL GUIDANCE SUGGESTS RH VALUES
   WOULD ONLY BECOME MARGINALLY LOW /AROUND 12 TO 20 PERCENT/.
   HOWEVER...GIVEN THE EXPECTED MAGNITUDE OF WINDS...A CRITICAL AREA
   APPEARS JUSTIFIED.
   
   ...MD...DE...NRN VA...D.C....
   LOW-LEVEL FLOW WILL SHIFT FROM WLY ON WED TO NWLY ON THU...RESULTING
   IN COOLER TEMPERATURES /PRIMARILY IN THE MIDDLE TO UPPER 70S/. THIS
   SHOULD MITIGATE THE DEVELOPMENT OF LOW RH...WITH VALUES FALLING INTO
   THE 30S. SUSTAINED SURFACE WINDS WILL ALSO BE SLIGHTLY WEAKER /NEAR
   15 MPH/ AS THE PRESSURE GRADIENT RELAXES. HOWEVER...POTENTIAL FOR
   GUSTS OF 25 TO 30 MPH SHOULD CONTRIBUTE TO A MARGINAL FIRE WEATHER
   THREAT.
   
   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
   
      

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