960  
FNUS21 KWNS 021601  
FWDDY1  
 
DAY 1 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1101 AM CDT TUE SEP 02 2025  
 
VALID 021700Z - 031200Z  
 
THE PREVIOUS FORECAST LARGELY REMAINS ON TRACK WITH ONLY MINOR  
ADJUSTMENTS MADE TO ACCOUNT FOR RECENT CONVECTIVE TRENDS. THROUGH 15  
UTC THIS MORNING, RADAR RAINFALL ESTIMATES AND LIGHTNING DATA  
SUGGEST A MIX OF WET AND DRY THUNDERSTORMS IS ONGOING ACROSS THE  
CENTRAL VALLEY. ADDITIONAL THUNDERSTORM DEVELOPMENT REMAINS LIKELY  
THROUGH THE EVENING HOURS ACROSS NORTHERN CA, NORTHWEST NV, AND  
CENTRAL OR. WHILE 12 UTC GUIDANCE HAS CAPTURED THE ONGOING ACTIVITY  
WELL, MOST SOLUTIONS INITIALIZED WITH A NOTABLE WARM/DRY BIAS ACROSS  
NORTHERN CA AND ADJACENT PORTIONS OF OR/NV, SUGGESTING THAT MOISTURE  
QUALITY MAY BE SLIGHTLY BETTER THAN DEPICTED BY MORNING SOLUTIONS.  
ADDITIONALLY, MID/HIGH-LEVEL CLOUD COVER ASSOCIATED WITH THE ONGOING  
SHOWERS/THUNDERSTORMS WILL CONTINUE TO SPREAD NORTH AND MAY MODULATE  
DIURNAL HEATING/MIXING TO SOME DEGREE OVER PARTS OF NORTHERN  
CA/SOUTHERN OR. THESE FACTORS, COUPLED WITH FORECAST PWAT VALUES  
BETWEEN 0.6 TO 0.8 INCHES, HINT THAT A MIX OF DRY/WET THUNDERSTORMS  
IS PROBABLE FOR NORTHERN CA/SOUTHERN OR WITH AN INCREASING CHANCE  
FOR DRY LIGHTNING WITH NORTH AND EASTWARD EXTENT IF/WHERE STORMS CAN  
DEVELOP AHEAD OF THE APPROACHING CLOUD COVER.  
 
..MOORE.. 09/02/2025  
   
PREV DISCUSSION
 
/ISSUED 0155 AM CDT TUE SEP 02 2025/  
   
..SYNOPSIS
 
 
A WEAK UPPER-LEVEL LOW WILL MOVE NORTHWARD ACROSS NORTHERN  
CALIFORNIA INTO THE PACIFIC NORTHWEST TODAY THROUGH D2/WEDNESDAY,  
WITH INCREASES IN MOISTURE AND FORCING LEADING TO THUNDERSTORM  
DEVELOPMENT. PRECIPITABLE WATER VALUES WILL APPROACH 0.60-0.90",  
DECREASING WITH EASTWARD EXTENT ACROSS EASTERN OREGON/WESTERN  
NEVADA. FASTER STORM MOTIONS AROUND 15-20 KTS WILL LIKELY LEAD TO A  
MIX OF WET/DRY THUNDERSTORMS. NEW STARTS WILL BE POSSIBLE WHERE  
LITTLE TO NO PRECIPITATION OCCURS, WITH ERCS AROUND THE 80TH-90TH  
PERCENTILE ACROSS PORTIONS OF THESE REGIONS. AN ISOLATED DRY  
THUNDERSTORM AREA WAS MAINTAINED WITH THIS OUTLOOK ACROSS PORTIONS  
OF NORTHERN CALIFORNIA INTO WESTERN NEVADA AN NORTHWARD INTO CENTRAL  
OREGON.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
 
 

 
 
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