571
FNUS21 KWNS 260608
FWDDY1
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0107 AM CDT WED AUG 26 2026
VALID 261200Z - 271200Z
...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN CALIFORNIA INTO
NORTHWESTERN GREAT BASIN...
..SYNOPSIS
AN UPPER-LEVEL TROUGH EDGING INTO THE PACIFIC NORTHWEST WILL BRING
WIDESPREAD FIRE WEATHER CONCERNS TO MUCH OF THE INTERIOR OF THE
NORTHWEST, NORTHERN GREAT BASIN AND NORTHERN ROCKIES TODAY. ISOLATED
DRY THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE NORTHERN ROCKIES,
WHILE DRY AND BREEZY CONDITIONS DEVELOP FARTHER WEST ACROSS THE
COLUMBIA BASIN SOUTH TOWARDS THE NORTHERN GREAT BASIN AND
NORTHEASTERN CA. AN INCREASING OFFSHORE PRESSURE GRADIENT WILL BRING
AN ELEVATED FIRE WEATHER THREAT TO PARTS OF SOUTHERN CA LATE THIS
AFTERNOON INTO THE OVERNIGHT HOURS AS DRY AND BREEZY CONDITIONS
DEVELOP.
..NORTHEASTERN CALIFORNIA INTO NORTHWESTERN GREAT BASIN
A NARROW CORRIDOR OF CRITICAL FIRE WEATHER CONDITIONS IS LIKELY
TODAY ACROSS THE NORTHWESTERN FRINGE OF THE GREAT BASIN. THE
UPPER-LEVEL TROUGH AND ATTENDANT INCREASING DEEP LAYER SOUTHWEST
FLOW WILL SUPPORT SOUTHWEST SURFACE WINDS OF AROUND 20 MPH. AN
EXISTING DRY AIR MASS WITH RH FALLING TO AS LOW AS 10% AND RECEPTIVE
FUELS WILL PROMOTE WILDFIRE SPREAD, WHERE SEVERAL ACTIVE FIRES ARE
PRESENT.
...COLUMBIA BASIN SOUTHWARD TOWARDS THE NORTHERN GREAT BASIN AND
NORTHERN SIERRA NEVADA...
AN UPPER TROUGH ENCROACHING UPON THE PACIFIC NORTHWEST WILL
STRENGTHEN MID-LEVEL SOUTHWEST WINDS ACROSS MUCH OF THE NORTHWESTERN
U.S. TODAY. ALTHOUGH UPPER-LEVEL CLOUD COVER WILL INHIBIT FULL
MIXING POTENTIAL ACROSS THE REGION, THE DEEP-LAYER SOUTHWEST FLOW
AIDED BY AN EMERGING SURFACE LOW ACROSS EASTERN WA/OR WILL
CONTRIBUTE TO SOUTHWEST WINDS OF 10-15 MPH FROM NORTHEASTERN CA INTO
EASTERN OR AND THE COLUMBIA BASIN. RELATIVE HUMIDITY REDUCTIONS BY
PEAK AFTERNOON HEATING WILL LIKELY REACH AROUND 15%.
..NORTHERN ROCKIES INTO NORTHERN WASHINGTON
THE APPROACHING UPPER TROUGH WILL PROMOTE BROAD BUT DIFFUSE FORCING
FOR ASCENT AS A MID/UPPER MOISTURE PLUME PUSHES INTO THE NORTHERN
ROCKIES. AFTERNOON INSTABILITY (MLCAPE VALUES IN THE 500-1000 J/KG
RANGE), A DRY SUB-CLOUD LAYER AND NORTHEAST SHOWER/THUNDERSTORM
TRAJECTORIES OF 25-35 MPH WITH PWATS GENERALLY LESS THAN 0.8",
SHOULD LIMIT SURFACE RAINFALL THIS AFTERNOON AND EVENING AS ISOLATED
DRY THUNDERSTORMS DEVELOP ACROSS THE CENTRAL ID MOUNTAINS NORTHWARD
INTO THE ID PANHANDLE AND WESTERN MT.
..SOUTHERN CALIFORNIA
HIGH PRESSURE ALOFT WILL CONTINUE TO SUPPORT DRY CONDITIONS AND NEAR
RECORD HIGH TEMPERATURES IN THE 90S AND 100S FARTHER INLAND AWAY
FROM COASTAL INFLUENCE. FUELS CONTINUE TO DRY, BECOMING INCREASINGLY
RECEPTIVE EACH DAY. AN OFFSHORE PRESSURE GRADIENT WILL PROMOTE
PRIMARILY NORTH WINDS OF 15-25 MPH AMID RH OF 15-20% THIS EVENING
INTO EARLY D2/THURSDAY MORNING. WINDS WILL BE STRONGEST IN FAVORED
TERRAIN GAPS AND DOWNSLOPE AREAS IN LA/VENTURA/SANTA BARBARA
COUNTIES.
..WILLIAMS.. 08/26/2026
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
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