687  
FNUS21 KWNS 031655  
FWDDY1  
 
DAY 1 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1155 AM CDT WED SEP 03 2025  
 
VALID 031700Z - 041200Z  
 
AN UPPER-LEVEL TROUGH SUPPORTING ONGOING CONVECTION ACROSS THE  
NORTHERN SIERRA NEVADA WILL PROMOTE EXPANDING SHOWERS AND  
THUNDERSTORMS ACROSS NORTHERN CA AS WELL AS THE CASCADES AND  
SOUTH-CENTRAL OR LATER THIS AFTERNOON. ADDITIONAL LIGHTNING  
IGNITIONS ARE POSSIBLE, PARTICULARLY IN DRIER, HEAVIER FUELS ALONG  
THE SHASTA SISKIYOUS AND CASCADES. THE NORTHEAST EXTENT OF DRY  
THUNDERSTORM HIGHLIGHTS WAS TRIMMED ACROSS PORTIONS OF CENTRAL OR AS  
WELL AS THE NORTHERN SACRAMENTO VALLEY AREA, SUPPORTED BY LATEST CAM  
AND ENSEMBLE MODEL GUIDANCE.  
 
..WILLIAMS.. 09/03/2025  
   
PREV DISCUSSION
 
/ISSUED 0149 AM CDT WED SEP 03 2025/  
   
..SYNOPSIS
 
 
A WEAK UPPER-LEVEL TROUGH WILL CONTINUE TO MOVE NORTHWARD ACROSS  
NORTHERN CALIFORNIA INTO THE PACIFIC NORTHWEST ON WEDNESDAY. LIFT  
ASSOCIATED WITH THIS FEATURE WILL PROMOTE ISOLATED TO SCATTERED  
THUNDERSTORM ACTIVITY. THUNDERSTORMS WILL LIKELY BE ONGOING AT THE  
BEGINNING OF THE PERIOD WITH A SECOND ROUND DEVELOPING BY THE  
AFTERNOON. OVERALL, A MIX OF WET/DRY THUNDERSTORMS IS EXPECTED  
ACROSS THE DRIEST FUELS IN NORTHERN CALIFORNIA, FAR WESTERN NEVADA,  
AND CENTRAL OREGON. WHILE LOCALLY HIGHER TOTALS WILL BE POSSIBLE IN  
THE STRONGEST STORMS, ENSEMBLE GUIDANCE GENERALLY SHOWS < 0.10"  
ACROSS MUCH OF THIS REGION. NEW LIGHTNING STARTS WERE REPORTED ON  
TUESDAY IN THESE AREAS, WITH RAINFALL AMOUNTS 0.10-0.25". AN  
ISOLATED DRY THUNDERSTORM AREA WAS MAINTAINED WITH THIS OUTLOOK TO  
SUPPORT THIS POTENTIAL.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page