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FNUS28 KWNS 242038
FWDD38

DAY 3-8 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0337 PM CDT FRI APR 24 2015

VALID 261200Z - 021200Z

STRONG SHORTWAVE TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD THROUGH
THE INTERMOUNTAIN WEST AND FOUR CORNERS REGION ON D3/SUNDAY...WITH
80-90 KNOT MID-LEVEL JET MAX LOCATED OVER CA/NV JUST WEST OF THE
SHORTWAVE TROUGH AXIS. DOWNSTREAM OF THIS SHORTWAVE...A BELT OF
ENHANCED MID-LEVEL FLOW WILL BE LOCATED ACROSS THE SOUTHERN TIER OF
THE U.S. FROM THE SOUTHERN ROCKIES TO THE CAROLINAS. THE WESTERN
U.S. SHORTWAVE TROUGH WILL CLOSE OFF OVER THE SRN ROCKIES AND SRN
HIGH PLAINS TOWARD THE END OF D3...THEN MAKE SLOW PROGRESS TOWARD
THE EAST INTO THE SRN PLAINS THROUGH D5/TUE. BY D6/WED...TROUGH WILL
OPEN UP AND MOVE NEWD TO THE OHIO VALLEY...WHILE SHORTWAVE RIDGING
DEVELOPS FROM THE LOWER CO RIVER VALLEY NORTHWARD TO THE NRN
ROCKIES. STRENGTHENING MID-LEVEL FLOW WILL OCCUR ACROSS THE PACIFIC
NW IN ADVANCE OF ANOTHER SHORTWAVE TROUGH ADVANCING UPON THE BRITISH
COLUMBIA COAST. SUBSTANTIAL MODEL DIFFERENCES DEVELOP ON D6 AND
BEYOND...DECREASING PREDICTABILITY DURING THAT TIME PERIOD.

...D3/SUN: WRN/SWRN TX AND SERN NM...
STRENGTHENING MID-LEVEL FLOW WILL OVERSPREAD SW TX AND FAR SERN NM
DURING THE D3 PERIOD IN ADVANCE OF SEWD MOVING SHORTWAVE TROUGH NEAR
THE AZ/NM BORDER AREA. A DRY BOUNDARY LAYER IS EXPECTED OVER THE
REGION...WITH AFTERNOON RH VALUES FORECAST TO DROP TO 10-15 PERCENT
PARTICULARLY OVER THE TRANS-PECOS REGION. GREATEST CONFIDENCE OF
CRITICAL FIRE WEATHER CONDITIONS EXISTS IN THE VICINITY OF THE
GUADALUPE MOUNTAINS...WHERE 20-30 MPH SUSTAINED SURFACE WINDS WITH
HIGHER GUSTS AND MINIMUM AFTERNOON RH VALUES OF 10-15 PERCENT ARE
POSSIBLE. TO THE NORTHWEST OF THIS AREA ACROSS SERN NM...SURFACE
WINDS WILL BE STRONGER BUT CONFIDENCE IS LOWER THAT CRITICAL RH
THRESHOLDS WILL BE MET. SOUTH OF THIS AREA...CONFIDENCE IS HIGH THAT
CRITICAL RH THRESHOLDS WILL BE MET...BUT SURFACE WINDS ARE FORECAST
TO BE WEAKER. GIVEN SUBSTANTIAL GREENUP IN SOME PARTS OF THE
REGION...FUELS MAY NOT BE DRY OR RECEPTIVE TO FIRE STARTS. AS A
RESULT...A 70 PERCENT/CRITICAL DESIGNATION WILL NOT BE ISSUED FOR
THIS OUTLOOK...BUT FUTURE OUTLOOKS WILL NEED TO BE MONITORED FOR
GREATER CONFIDENCE OF A CRITICAL FIRE WEATHER THREAT.

...D3/SUN: WRN AZ/SERN CA...
SOLAR HEATING BENEATH A STRONG MID-LEVEL JET OVER THE REGION WILL
PROMOTE VERTICAL MIXING AND DOWNWARD TRANSPORT OF HIGHER-MOMENTUM
AIR...YIELDING AFTERNOON SURFACE WINDS EXCEEDING CRITICAL
THRESHOLDS. WITH AFTERNOON RH VALUES FALLING BELOW 10 PERCENT IN
PARTS OF THE REGION...AT LEAST ELEVATED FIRE WEATHER CONDITIONS ARE
POSSIBLE IN THIS AREA BUT CONCERNS ABOUT DRYNESS/AVAILABILITY OF
FUELS PRECLUDE ISSUANCE OF A 70 PERCENT/CRITICAL AREA AT THIS TIME.

...D4/MON: SRN CA...
HIGH PRESSURE BUILDING IN TO THE GREAT BASIN ON D4 WILL CONTRIBUTE
TO MODERATE OFFSHORE FLOW IN THE LEE OF THE MOUNTAINS OF SRN CA.
WITH A DRYING BOUNDARY LAYER DUE TO DOWNSLOPE FLOW AND RH VALUES
DROPPING TO NEAR 15 PERCENT ACROSS INLAND AREAS...EXPECT AT LEAST A
BRIEF PERIOD OF ELEVATED FIRE WEATHER CONCERNS IN TYPICALLY-FAVORED
AREAS OF VENTURA AND LOS ANGELES COUNTIES. A LIMITING FACTOR MAY BE
PRECEDING RAINFALL FORECAST TO OCCUR ON D3/SUN ACROSS THE
AREA...WHICH MAY ALTER THE STATE OF THE FUELS ENOUGH TO LIMIT FIRE
THREAT. AFTER COLLABORATING WITH LOCAL OFFICES...A 40
PERCENT/ELEVATED AREA WAS ADDED TO THE VENTURA/LOS ANGELES COUNTY
MOUNTAINS AND FOOTHILLS TO ADDRESS THE POTENTIAL FIRE WEATHER
THREAT. THIS AREA WILL CONTINUE TO BE MONITORED IN FUTURE OUTLOOKS.

..COOK/LEITMAN.. 04/24/2015

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




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