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 281602
   
   DAY 1 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1102 AM CDT SAT AUG 28 2010
   
   VALID 281700Z - 291200Z
   
   ...CRITICAL FIRE WEATHER AREA FOR MUCH OF NV / WRN UT / SERN CA /
   FAR NWRN AZ...
   
   NO CHANGES NEEDED.
   
   ..SMITH.. 08/28/2010
   
   .PREV DISCUSSION... /ISSUED 0201 AM CDT SAT AUG 28 2010/
   
   ...SYNOPSIS...
   AN UPPER TROUGH WILL DEEPEN OVER THE WRN CONUS...WITH MID-LEVEL
   WINDS INCREASING ACROSS THE GREAT BASIN IN RESPONSE. A SFC LOW
   PRESSURE SYSTEM AND COLD FRONT WILL DEVELOP AND PUSH SEWD ACROSS NV
   AND CA THIS AFTERNOON. STRONG WINDS WITHIN A DRYING AIR MASS WILL
   LEAD TO CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS OF SRN CA
   AND THE WRN GREAT BASIN. FARTHER E...A LEE SFC TROUGH WILL DEVELOP
   OVER THE HIGH PLAINS OF CO/WY...WHILE SCATTERED THUNDERSTORMS MAY
   EXIST FROM THE FOUR CORNERS REGION INTO THE CNTRL ROCKIES AND NRN
   HIGH PLAINS.
   
   ...MUCH OF NV...WRN UT...SERN CA...FAR NWRN AZ...
   A DEEPENING UPPER TROUGH AND ASSOCIATED MID-LEVEL SPEED MAX
   CURRENTLY LOCATED OFF THE NRN CA COAST /PER EARLY MORNING WATER
   VAPOR IMAGERY/ WILL SHIFT TOWARDS THE WRN GREAT BASIN TODAY. AS THIS
   OCCURS...DEEP-LAYER WIND FIELDS WILL INCREASE COINCIDENT WITH A
   STRENGTHENING SFC PRESSURE GRADIENT IN RESPONSE TO PRESSURE FALLS
   OVER NERN NV. THE STRONGEST WINDS WITHIN THE CRITICAL AREA WILL
   OCCUR BENEATH 50-60 KT MID-LEVEL FLOW STRETCHING FROM THE SRN SIERRA
   NV MOUNTAINS INTO SWRN UT. SUSTAINED SFC WIND SPEEDS OF 20-30 MPH
   /GUSTS 35-45 MPH/ ARE EXPECTED TO DEVELOP BY LATE MORNING. ALTHOUGH
   SOMEWHAT COOLER TEMPERATURES /70S ACROSS CNTRL NV TO LOWER 90S IN
   SRN NV/CA / RELATIVE TO THE PAST FEW DAYS WILL BE PRESENT AS
   THICKNESS FALLS OCCUR AHEAD OF THE APPROACHING UPPER TROUGH...VERY
   DRY MID-LEVEL AIR WILL READILY MIX DOWN TO THE SFC...AND RESULT IN
   MIN RH VALUES RANGING FROM THE SINGLE DIGITS TO THE LOWER TEENS. A
   SFC COLD FRONT WILL SHIFT INTO CNTRL NV BY LATE AFTERNOON...WITH
   WINDS BECOMING NWLY IN THE POST-FRONTAL AIR MASS.
   
   ...CNTRL/ERN WY...
   MODERATELY STRONG MID-LEVEL FLOW /AROUND 30 KTS AT 500 MB/ WILL
   EXTEND ACROSS MUCH OF WY AHEAD OF A DEEPENING WRN CONUS TROUGH. AT
   THE SFC...A LEE TROUGH WILL DEVELOP ACROSS THE HIGH PLAINS OF ERN
   WY/CO...RESULTING IN STRENGTHENING SWLY WINDS SUSTAINED AROUND 15-20
   MPH ACROSS PORTIONS OF CNTRL/ERN WY. ENOUGH MOISTURE WILL REMAIN
   PRESENT TO LIMIT A MORE SIGNIFICANT FIRE WEATHER THREAT...WITH MIN
   RH VALUES EXPECTED TO REACH THE LOW 20S. ADDITIONALLY...THE
   POTENTIAL WILL EXIST FOR ISOLATED-SCATTERED THUNDERSTORM DEVELOPMENT
   THIS AFTERNOON.
   
   ...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 281904
   
   DAY 2 FIRE WEATHER OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0204 PM CDT SAT AUG 28 2010
   
   VALID 291200Z - 301200Z
   
   ...NO CRITICAL AREAS...
   
   MAIN IMPETUS FOR MAINTAINING CATEGORICAL SEE TEXT ACROSS WY WHERE
   POTENTIAL CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR IS MODEL
   VARIABILITY ACCORDING TO SATURDAY MORNING 12Z MODEL OUTPUT.  THE GFS
   DEPICTS A DRIER MORE DEEPLY MIXED BOUNDARY LAYER WHEREAS THE NAM
   SUSTAINS NON-CRITICAL RH VALUES THROUGHOUT MUCH OF THE DAY. 
   SATURDAY MORNING OBSERVED DATA INDICATE A SUBSTANTIAL UNDERFORECAST
   BY RECENT MODELS IN SURFACE MOISTURE ACROSS THIS REGION. 
   REGARDLESS...STRONG TO VERY STRONG SUSTAINED WINDS ARE FORECAST AND
   WILL ENHANCE THE OVERALL FIRE WEATHER THREAT.  WILL DEFER POSSIBLE
   UPGRADE OVER WY TO LATER OUTLOOKS.
   
   ..SMITH.. 08/28/2010
   
   .PREV DISCUSSION... /ISSUED 0345 AM CDT SAT AUG 28 2010/
   
   ...SYNOPSIS...
   AN AMPLIFIED UPPER TROUGH WILL CONTINUE TO SLOWLY SHIFT EWD ACROSS
   THE WRN CONUS...WITH A BROAD ZONE OF ENHANCED MID-LEVEL FLOW
   EXTENDING FROM THE DESERT SOUTHWEST INTO THE NRN PLAINS. AT THE
   SFC...STRONG WINDS WILL EXIST OVER NRN AZ/UT AND ACROSS ERN
   WY...WHILE A COLD FRONT SLOWLY MOVES SEWD OVER THE GREAT BASIN. COOL
   TEMPERATURES WILL RESIDE OVER MUCH OF THE PAC NW AND INTER-MTN WEST.
   
   ...CNTRL/SRN UT...NRN AZ...
   A BELT OF 50-60 KT SWLY MID-LEVEL FLOW WILL BE POSITIONED OVER THE
   REGION AHEAD OF AN UPPER TROUGH. SFC WINDS WILL STRENGTHEN RAPIDLY
   DURING THE LATE MORNING HRS AS VERTICAL MIXING COMMENCES...RESULTING
   IN SUSTAINED SPEEDS OF 15-25 MPH /GUSTS TO 45 MPH/. THE AIR MASS
   WILL BECOME MUCH DRIER AND COOLER THAN PREVIOUS DAYS...WITH SFC
   TEMPERATURES GENERALLY IN THE 60S AND 70S. DESPITE THE PRESENCE OF
   DRIER AIR...CURRENT FORECAST MODEL GUIDANCE INDICATES MIN RH VALUES
   WILL GENERALLY REMAIN AOA CRITICAL THRESHOLDS /15 PERCENT OR
   GREATER/. IN ADDITION...CONSIDERABLE UNCERTAINTY EXISTS REGARDING
   THE MAGNITUDE AND COVERAGE OF RAINFALL THAT MAY OCCUR SAT/D1...WHICH
   MAY TEMPER THE OVERALL FIRE WEATHER THREAT. NEVERTHELESS...NEAR
   CRITICAL TO LOCALLY CRITICAL CONDITIONS APPEAR PROBABLE...AND THIS
   AREA WILL CONTINUE TO BE MONITORED FOR A POTENTIAL UPGRADE IN FUTURE
   OUTLOOKS.
   
   ...CNTRL/ERN WY...
   STRONG WINDS ARE EXPECTED TO DEVELOP ONCE AGAIN DURING THE DAYTIME
   AS A LEE SFC TROUGH DEEPENS OVER THE NRN HIGH PLAINS. DEEP VERTICAL
   MIXING SHOULD RESULT IN STRONGER MID-LEVEL WINDS /40-50 KTS/ MIXING
   DOWN TO THE SFC...WITH SUSTAINED SPEEDS RANGING FROM 15-25 MPH.
   MINIMUM HUMIDITY VALUES ARE EXPECTED TO GENERALLY REMAIN ABOVE
   CRITICAL THRESHOLDS DUE TO SLIGHT COOLING ACROSS CNTRL WY...AND
   ADEQUATE MOISTURE IN PLACE OVER THE HIGH PLAINS OF ERN WY.
   HOWEVER...LOCALLY CRITICAL CONDITIONS MAY STILL BE OBSERVED.
   
   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
   
      

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