265  
FNUS21 KWNS 250601  
FWDDY1  
 
DAY 1 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0101 AM CDT TUE AUG 25 2026  
 
VALID 251200Z - 261200Z  
   
..SYNOPSIS
 
 
A MID-LEVEL WAVE EMBEDDED IN BROADER SOUTHWEST FLOW ON THE WESTERN  
PERIPHERY OF A HIGH-AMPLITUDE UPPER RIDGE IS EXPECTED TO MOVE INTO  
THE NORTHERN ROCKIES THROUGH TODAY. THIS FEATURE ALONG WITH DAYTIME  
DESTABILIZATION WILL AID IN ISOLATED THUNDERSTORM DEVELOPMENT FROM  
THE WALLOWA MOUNTAINS IN NORTHEAST OR INTO CENTRAL ID AND FAR  
SOUTHWEST MT. DRY SOUTHWEST FLOW IN THE WAKE OF THIS FEATURE WILL  
BRING A FIRE WEATHER CONCERN TO PORTIONS OF NORTHEAST CA, NORTHWEST  
NV AND SOUTHEASTERN OR. A WEAK OFFSHORE PRESSURE GRADIENT IN THE  
EVENING AND OVERNIGHT HOURS WILL BRING DRY AND BREEZY CONDITIONS AND  
A FIRE WEATHER THREAT TO PORTIONS OF SOUTHERN CA.  
 
...NORTHEASTERN OREGON, CENTRAL IDAHO MOUNTAINS AND FAR SOUTHWESTERN  
MONTANA...  
HIGH-BASED CONVECTION IS EXPECTED THIS AFTERNOON FROM FAR  
NORTHEASTERN OR MOUNTAINS, EASTWARD INTO PORTIONS OF THE NORTHERN  
ROCKIES AS THE MID-LEVEL WAVE MOVES INTO THE REGION AMID INCREASING  
AFTERNOON INSTABILITY. INVERTED-V FORECAST SOUNDINGS, PWAT VALUES OF  
ONLY 0.5" TO 0.8" AND HIGH SURFACE DEW POINT DEPRESSIONS (SURFACE  
DEWPOINTS IN THE 30S TO 40S F) WILL LIKELY SUPPORT MOSTLY DRY  
ISOLATED THUNDERSTORM ACTIVITY THIS AFTERNOON. FUELS REMAIN DRY  
RECEPTIVE AS EVIDENCED BY NEW RECENT LIGHTNING IGNITIONS ACROSS  
NORTHEASTERN CA AND NORTHWESTERN NV, WITH ERC VALUES IN THE 90-95TH  
PERCENTILE RANGE STRETCHING NORTHEASTWARD INTO CENTRAL ID.  
   
..NORTHEASTERN CALIFORNIA INTO NORTHERN GREAT BASIN
 
 
MODEST SOUTHWEST WINDS ALOFT, AN INCREASINGLY DRY BOUNDARY LAYER AND  
AN EFFICIENT DAYTIME MIXING ENVIRONMENT WILL BRING GUSTY SOUTHWEST  
WINDS TO PORTIONS OF NORTHEASTERN CA INTO THE NORTHERN GREAT BASIN  
FOR SEVERAL HOURS THIS AFTERNOON. SOUTHWEST WINDS OF 10-15 MPH WITH  
HIGHER GUSTS AND RH AS LOW AS 15 PERCENT WILL RESULT IN ELEVATED  
FIRE WEATHER CONDITIONS. LOCALLY CRITICAL FIRE WEATHER CONCERNS WILL  
EXIST WHERE WINDS BRIEFLY REACH 20 MPH. RECENT LIGHTNING AND  
RESULTANT NEW WILDFIRES ACROSS NORTHEASTERN CA AND NORTHWESTERN NV  
WILL BE EXPOSED TO THIS ADVERSE FIRE WEATHER ENVIRONMENT THIS  
AFTERNOON.  
   
..SOUTHERN CALIFORNIA
 
 
AN ELEVATED FIRE WEATHER THREAT WILL EVOLVE THIS EVENING AND  
OVERNIGHT ACROSS PORTIONS OF SOUTHERN CALIFORNIA AS OFFSHORE FLOW  
DEVELOPS AMID AN INCREASINGLY RECEPTIVE FUELSCAPE. OFFSHORE WINDS OF  
15-25 MPH ARE EXPECTED IN FAVORED TERRAIN GAPS AND DOWNSLOPE REGIONS  
OF LA/VENTURA/SANTA BARBARA COUNTIES AS RH FALLS TO AS LOW AS 15  
PERCENT, PRIMARILY THIS EVENING INTO EARLY WEDNESDAY MORNING.  
 
..WILLIAMS.. 08/25/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
 
 

 
 
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