Storm Prediction Center Fire Weather Outlook

• Day 1 fire weather outlook and map
• Day 2 fire weather outlook and map

Day 1 Fire Weather Outlook

	    
   NWS STORM PREDICTION CENTER NORMAN OK
   1158 AM CDT FRI MAY 24 2013

   VALID 241700Z - 251200Z

   ...CRITICAL FIRE WEATHER AREA FOR NRN AZ...PORTIONS OF NWRN/W-CNTRL
   NM...PORTIONS OF SRN UT...SWRN CO...FAR SRN NV...A SMALL PART OF
   SERN CA...

   ...NRN AZ...PORTIONS OF NWRN/W-CNTRL NM...PORTIONS OF SRN UT...SWRN
   CO...FAR SRN NV...A SMALL PART OF SERN CA...
   NO CHANGES HAVE BEEN MADE TO THE AREAL DELINEATION OF CRITICAL FIRE
   WEATHER CONDITIONS. MODESTLY STRONG SWLY FLOW ALOFT CONTINUES ACROSS
   THE AREA IN CONJUNCTION WITH AN ENHANCED MID-LEVEL HEIGHT GRADIENT
   BETWEEN A WRN-CONUS TROUGH AND A CNTRL-CONUS RIDGE. THE 12Z
   FLAGSTAFF RAOB AND RECENT VWP DATA INDICATE AROUND 30-40 MPH OF FLOW
   AOA 3 KFT AGL...AND THIS WILL SUPPORT THE POTENTIAL FOR STRONG SFC
   WINDS AS VERTICAL MIXING DIURNALLY STRENGTHENS.

   THE LATEST MODEL GUIDANCE INDICATES A POTENTIAL FOR SUBTLE WEAKENING
   OF 700-MB FLOW DURING THE DAY...WHICH COULD CORRESPOND TO SFC WIND
   SPEEDS BECOMING ONLY MARGINALLY STRONG DURING THE AFTERNOON.
   REGARDLESS...SLY TO SWLY SFC WINDS AROUND 20 MPH WITH LOCALLY HIGHER
   GUSTS ARE EXPECTED TO COMBINE WITH RH VALUES FROM THE UPPER SINGLE
   DIGITS TO THE MIDDLE TEENS AMIDST BELOW-NORMAL PRECIPITATION DURING
   THE PAST FEW MONTHS TO SUPPORT LOW-END CRITICAL FIRE WEATHER
   CONDITIONS. IN FACT...WIND SPEEDS MAY BE A LITTLE WEAKER THAN THOSE
   YESTERDAY. REGARDLESS...WITH THE LOW-END CRITICAL FIRE WEATHER
   THREAT STILL ANTICIPATED...THE CRITICAL AREA HAS BEEN MAINTAINED
   FOLLOWING COORDINATION WITH THE FLAGSTAFF WEATHER FORECAST OFFICE.

   ...SRN AZ...
   TO THE SOUTH OF THE CRITICAL AREA...ELEVATED FIRE WEATHER CONDITIONS
   ARE EXPECTED AS RH VALUES BECOME CRITICALLY LOW. HOWEVER...ANY MORE
   THAN SPOTTY AND/OR BRIEF INSTANCES OF CRITICALLY STRONG SUSTAINED
   WIND SPEEDS ARE NOT EXPECTED IN THE ABSENCE OF STRONGER
   LOW/MID-LEVEL FLOW.

   ...MOUNTAINS OF CNTRL NM AND THE IMMEDIATELY ADJACENT HIGH PLAINS...
   OVER THE WRN FRINGES OF RICHER LOWER/MIDDLE-TROPOSPHERIC
   MOISTURE...ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED
   TO DEVELOP THIS AFTERNOON ACROSS THE CNTRL NM MOUNTAINS AS
   OROGRAPHIC CIRCULATIONS OFFER LOW-LEVEL ASCENT. HIGH-BASED
   CONVECTIVE INITIATION IS FORECAST TO OCCUR IN AN ENVIRONMENT
   CHARACTERIZED BY PW VALUES BETWEEN 0.50 AND 0.75 INCH PER GPS DATA
   SUPPORTING ISOLATED TO WIDELY SCATTERED DRY THUNDERSTORMS...AS 20-35
   MPH OF MID-LEVEL FLOW YIELD MODEST STORM MOTIONS FROM THE MOUNTAINS
   TO THE IMMEDIATELY ADJACENT HIGH PLAINS. IN THE ABSENCE OF STRONGER
   DEEP FORCING FOR ASCENT...ANY DRY THUNDERSTORM COVERAGE SHOULD BE
   ISOLATED TO WIDELY SCATTERED. REGARDLESS...DRY/VERY DRY FUELS MAY
   PROMOTE LIGHTNING-INDUCED IGNITIONS AS SFC RH VALUES FALL TO AROUND
   15-20 PERCENT AMIDST DRY/VERY DRY FUELS...AND THERMODYNAMIC PROFILES
   BECOME CHARACTERIZED BY DEEP INVERTED-VEE STRUCTURES.

   AS THUNDERSTORMS ADVANCE OVER THE LOWER ELEVATIONS OF ERN NM AND
   ENCOUNTER RICHER LOW-LEVEL MOISTURE/GREATER
   BUOYANCY...EVOLVING/MERGING COLD POOLS MAY GIVE WAY TO SOMEWHAT
   HIGHER THUNDERSTORM COVERAGE. HOWEVER...THIS ACTIVITY WILL ENCOUNTER
   INCREASINGLY HIGHER PW/HIGHER SFC RH...WITH THUNDERSTORM MODES
   TRANSITIONING TO MIXED WET/DRY. REGARDLESS...LIGHTNING STRIKES
   OUTSIDE OF RAIN CORES COULD YIELD IGNITIONS AMIDST ONGOING DROUGHT
   CONDITIONS.

   WITH THE COVERAGE OF PURELY DRY THUNDERSTORMS NOT EXPECTED TO EXCEED
   WIDELY SCATTERED...A CRITICAL AREA HAS NOT BEEN INCLUDED AT THIS
   TIME.

   ..COHEN.. 05/24/2013

   .PREV DISCUSSION... /ISSUED 0404 AM CDT FRI MAY 24 2013/

   ...SYNOPSIS...
   A POTENT SHORTWAVE TROUGH...ROTATING THROUGH THE FLOW SURROUNDING
   THE PACIFIC NORTHWEST UPPER LOW...WILL CONTINUE TO LIFT
   NORTH/NORTHEAST ACROSS THE NORTHERN ROCKIES TODAY. AHEAD OF THIS
   TROUGH...SHORTWAVE RIDING IS EXPECTED TO CONTINUE TO BUILD ACROSS
   THE CENTRAL US...WHICH IN TURN SHOULD AID THE DEEPENING OF THE
   EASTERN CONUS TROUGH.

   ACROSS THE SOUTHWESTERN STATES...A ZONE OF ENHANCED WEST/SOUTHWEST
   FLOW SHOULD PERSIST THROUGH MUCH OF TODAY. HERE...DIURNAL HEATING
   SHOULD RESULT IN DEEP MIXING OF AN ALREADY DRY BOUNDARY
   LAYER...RESULTING IN DAYTIME HIGH TEMPERATURES WARMING INTO THE 80S
   AND 90S COUPLED WITH SFC DEWPOINTS FALLING INTO THE SINGLE DIGITS TO
   LOW TEENS /YIELDING RELATIVE HUMIDITY VALUES IN THE SINGLE DIGITS TO
   LOW TEENS FOR MUCH OF THE AFTERNOON/. FURTHERMORE GIVEN THE STRONG
   FLOW ALOFT AND THE DEEP MIXING...STRONG/GUSTY WINDS ARE EXPECTED TO
   MIX DOWN TO THE SFC RESULTING IN A PROLONGED PERIOD OF CONDITIONS
   EXCEEDING THE CRITICAL THRESHOLD.

   ...SOUTHERN ARIZONA...
   TO THE SOUTH OF THE CRITICAL AREA...MID-LEVEL FLOW IS EXPECTED TO
   REMAIN WEAKER THAN FARTHER NORTH. THUS...EVEN THROUGH SFC RH VALUES
   WILL EXCEED CRITICAL THRESHOLDS...DIURNAL MIXING WILL ONLY RESULT IN
   SUB-CRITICAL THRESHOLD SFC WINDS /15-20 MPH/.

   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...

      

Day 2 Fire Weather Outlook

 STORM PREDICTION CENTER NORMAN OK
   0458 AM CDT FRI MAY 24 2013

   VALID 251200Z - 261200Z

   ...CRITICAL FIRE WEATHER AREA FOR FAR SOUTHERN NEVADA...EXTREME
   SOUTHERN UTAH...NORTHERN ARIZONA...WEST CENTRAL AND NORTHWEST NEW
   MEXICO...AND SOUTHWEST COLORADO...

   ...SYNOPSIS...
   AN UPPER LOW IS FORECAST TO REMAIN NEARLY STATIONARY ACROSS THE
   PACIFIC NORTHWEST AS A SERIES OF SUBTLE SHORTWAVE TROUGHS ROTATES
   THROUGH THE LARGER SCALE FLOW AROUND THIS LOW ON SATURDAY. 

   ACROSS THE SOUTHWESTERN STATES...A ZONE OF ENHANCED WEST/SOUTHWEST
   FLOW IS EXPECTED TO PERSIST THROUGH SATURDAY. HERE /ONCE AGAIN/
   STRONG INSOLATION SHOULD RESULT IN DEEP MIXING OF A PERSISTENTLY DRY
   BOUNDARY LAYER...RESULTING IN WARM DAYTIME TEMPERATURES /80S AND
   90S/ AND LOW AND RELATIVE HUMIDITY VALUES IN THE SINGLE DIGITS TO
   LOW TEENS FOR MUCH OF THE DAY. ADDITIONALLY...GIVEN THE RELATIVELY
   STRONG FLOW ALOFT AND THE FORECAST DEEP MIXING...STRONG/GUSTY SFC
   WINDS /20-25 MPH WITH GUSTS TO 30/ SHOULD DEVELOP...WARRANTING THE
   CRITICAL RISK.

   ...SOUTHERN ARIZONA...
   CONDITIONS HERE APPEAR TO BE SIMILAR TO THOSE FARTHER NORTH IN THE
   CRITICAL AREA. ONE MITIGATING FACTOR IN THIS AREA IS THAT IT THIS
   AREA IS A LITTLE MORE REMOVED FROM THE STRONG MID-LEVEL FLOW AND
   THUS AFTERNOON MIXING SHOULD RESULT IN SLIGHTLY WEAKER SFC WINDS
   NEARING...BUT NOT ACHIEVING...CRITICAL THRESHOLDS FOR THE REQUISITE
   DURATION /3 HRS/.

   ..MARSH.. 05/24/2013

   ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...

      

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