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FNUS28 KWNS 272011
FWDD38

DAY 3-8 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0310 PM CDT SAT AUG 27 2016

VALID 291200Z - 041200Z

ENHANCED FLOW ALOFT WILL BE GENERALLY CONFINED TO THE NRN TIER OF
THE CONUS ON D3/MON...AS UPPER RIDGING PREVAILS OVER MUCH OF THE
CNTRL/ERN CONUS. LARGE-SCALE UPPER TROUGHING WILL DEEPEN ACROSS THE
ERN PACIFIC MON AFTERNOON/EVENING...AND STRONGER MID-LEVEL WINDS
SHOULD OVERSPREAD PARTS OF THE PACIFIC NORTHWEST. THIS UPPER TROUGH
IS FORECAST TO AMPLIFY FURTHER FROM D4/TUE THOUGH AT LEAST D6/THU AS
IT DEVELOPS SLOWLY EWD ACROSS THE WRN CONUS. LATEST MEDIUM-RANGE
MODEL GUIDANCE REMAINS IN GENERALLY GOOD AGREEMENT REGARDING THE
TIMING AND AMPLITUDE OF A SHORTWAVE TROUGH FORECAST TO ROTATE AROUND
THE BASE OF THE TROUGH AND ACROSS PARTS OF NRN CA...THE WRN GREAT
BASIN...AND INTERIOR PACIFIC NORTHWEST ON D4/TUE. THE EVOLUTION OF
THE WRN CONUS UPPER TROUGH BECOMES LESS CLEAR FROM D6/THU
ONWARD...AS MODEL SOLUTIONS REGARDING THIS FEATURE DIVERGE.
REGARDLESS...ENHANCED MID-LEVEL FLOW SHOULD OVERLIE PORTIONS OF THE
GREAT BASIN AND INTERIOR PACIFIC NORTHWEST FROM D3/MON THOUGH AT
LEAST D6/THU.

...D3/MON - D6/THU: PORTIONS OF THE GREAT BASIN AND INTERIOR PACIFIC
NORTHWEST...
FOR D3/MON...AN INCREASE IN MID-LEVEL WINDS MAY OCCUR ACROSS NRN CA
INTO CNTRL/ERN ORE AS THE UPPER TROUGH OVER THE ERN PACIFIC MOVES
SLOWLY EWD. A CORRESPONDING MODEST STRENGTHENING OF LOW-LEVEL WINDS
WILL PROBABLY BE REALIZED ACROSS THE SAME GENERAL AREA MON AFTERNOON
AS RH VALUES BECOME LOWERED THROUGH DIURNAL MIXING AND DOWNSLOPE
PROCESSES. AT THIS TIME...FORECAST SFC WIND SPEEDS DO NOT APPEAR
STRONG ENOUGH TO SUPPORT A CRITICAL FIRE WEATHER THREAT.
THEREFORE...NO PROBABILITIES HAVE BEEN INTRODUCED FOR
D3/MON...ALTHOUGH ELEVATED CONDITIONS MAY BE REALIZED.

FOR D4/TUE...THE SHORTWAVE TROUGH MENTIONED ABOVE WILL MOVE NEWD
ACROSS NRN CA...THE WRN GREAT BASIN...AND INTERIOR PORTIONS OF THE
PACIFIC NORTHWEST. A BELT OF STRONGER MID-LEVEL WINDS ATTENDANT TO
THE SHORTWAVE TROUGH WILL SPREAD OVER THIS REGION...AND THERE WILL
BE SOME POTENTIAL FOR A SUFFICIENT OVERLAP OF STRONG/GUSTY LOW-LEVEL
WINDS WITH CRITICALLY LOWERED RH VALUES AND DRY FUELS TO SUPPORT THE
INTRODUCTION OF A 40 PERCENT/MARGINAL AREA. IN ADDITION...CONFIDENCE
IN THE POSSIBILITY OF ISOLATED THUNDERSTORMS OCCURRING ON D4/TUE
ALONG/E OF THE CASCADES/NRN SIERRAS HAS INCREASED ENOUGH TO
INTRODUCE A 10 PERCENT PROBABILITY OF ISOLATED DRY THUNDERSTORMS FOR
FAR NERN CA...FAR NWRN NV...AND PARTS OF CNTRL/ERN ORE. ACROSS THIS
REGION...FORECAST SOUNDINGS SHOW PWAT VALUES SUPPORTING GENERALLY
DRY THUNDERSTORMS ALONG WITH A WELL-MIXED/DRY SUB-CLOUD LAYER AND
ENHANCED MID-LEVEL WINDS.

FOR D5/WED AND D6/THU...STRONGER SWLY MID-LEVEL WINDS ARE FORECAST
TO REMAIN ACROSS SOME PORTION OF THE GREAT BASIN AND PERHAPS
INTERIOR PACIFIC NORTHWEST...ALTHOUGH CONFIDENCE IN WHERE LOW-LEVEL
WINDS WILL OVERLAP REGIONS OF SUFFICIENTLY LOWERED RH VALUES IS LOW.
REGARDLESS...THERE SHOULD BE SOME POTENTIAL FOR CRITICAL FIRE
WEATHER CONDITIONS ACROSS PARTS OF THIS REGION BOTH WED AND THU
AFTERNOONS...AND PROBABILITIES MAY NEED TO BE INTRODUCED IN A LATER
OUTLOOK PENDING BETTER MODEL AGREEMENT.

..GLEASON.. 08/27/2016

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

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