523  
FNUS22 KWNS 211845  
FWDDY2  
 
DAY 2 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0144 PM CDT THU AUG 21 2025  
 
VALID 221200Z - 231200Z  
 
THE ISODRYT AREAS WERE MERGED AND EXPANDED. SCATTERED MIXED WET/DRY  
THUNDERSTORMS ARE LIKELY ACROSS MUCH OF UTAH AND WESTERN COLORADO,  
WITH PWAT VALUES OF 0.7-0.9" AND STORM MOTIONS OF 10-20 KNOTS.  
WETTING RAIN IS LIKELY IN SOME AREAS DUE TO THE INCREASING MONSOONAL  
MOISTURE AND TRAINING OF STORMS. HOWEVER, DUE TO THE VERY/RECORD DRY  
FUELS, POTENTIAL FOR DEEP PYROCONVECTION ON ACTIVE LARGE FIRES, AND  
ANTICIPATED LOCALLY ELEVATED CONDITIONS, THE ISODRYT WAS EXPANDED.  
ISOLATED MIXED WET/DRY THUNDERSTORMS ARE POSSIBLE IN PORTIONS OF THE  
PENINSULAR RANGES OF SOUTHERN CALIFORNIA AND INTO THE MOJAVE, AND  
ISOLATED HIGH-BASED SHOWERS WITH EMBEDDED THUNDERSTORMS ARE ALSO  
POSSIBLE IN SOUTHERN CALIFORNIA OVERNIGHT.  
 
AN ELEVATED AREA WAS INTRODUCED FOR PORTIONS OF EASTERN NEW ENGLAND.  
DRY/BREEZY NORTHERLY WINDS ARE LIKELY AS HURRICANE ERIN PASSES  
OFFSHORE AND FUELS ARE RECEPTIVE, ESPECIALLY IN MAINE, WHERE FIRE  
ACTIVITY HAS INCREASED RECENTLY.  
 
HOT/DRY/UNSTABLE/BREEZY CONDITIONS ARE EXPECTED ALONG THE THERMAL  
TROUGH EXTENDING FROM SOUTHERN CALIFORNIA INTO THE NORTHWEST. HIGHER  
PROBABILITIES OF THE HOT, DRY, WINDY INDEX EXCEEDING THE 95TH  
PERCENTILE AND LOCALLY ELEVATED WINDS/RH ARE FORECAST IN PORTIONS OF  
CALIFORNIA, OREGON, AND WASHINGTON NEAR THE THERMAL TROUGH.  
 
..NAUSLAR.. 08/21/2025  
   
PREV DISCUSSION  
/ISSUED 0157 AM CDT THU AUG 21 2025/  
   
..SYNOPSIS  
 
AS THE UPPER RIDGE PERSIST OVER THE WEST, SEVERAL SUBTROPICAL  
PERTURBATIONS WILL ARRIVE FROM THE SOUTH, USHERING IN ANOTHER SURGE  
OF MONSOON MOISTURE. ISOLATED THUNDERSTORMS ARE LIKELY ACROSS THE  
SOUTHERN SIERRA AND INTO PARTS OF THE GREAT BASIN FRIDAY. WITH VERY  
WARM SURFACE TEMPERATURES AND DRY SUB-CLOUD LAYERS, LITTLE WETTING  
RAINFALL IS EXPECTED. THIS SHOULD ALLOW FOR ISOLATED DRY LIGHTNING  
ATOP RECEPTIVE FUEL MAINLY OVER PORTIONS OF CALIFORNIA AND NEVADA  
WHERE FUELS ARE MOST RECEPTIVE. SOME LOCALIZED DRY AND BREEZY WINDS  
MAY ALSO OCCUR OUTSIDE OF THE THUNDERSTORMS OVER THE CENTRAL GREAT  
BASIN FRIDAY.  
 
OVER THE SOUTHERN GREAT BASIN AND SOUTHWEST, HIGHER PWATS NEAR 1  
INCH ARE EXPECTED. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE  
LIKELY THROUGH THE AFTERNOON. HOWEVER, A WETTER STORM MODE IS MORE  
PROBABLE ACROSS NORTHERN ARIZONA, SOUTHERN UTAH AND WESTERN  
COLORADO, WHERE FUELS ARE ALSO LESS RECEPTIVE.  
   
..CALIFORNIA  
 
ISOLATED THUNDERSTORMS ARE LIKELY IN PORTIONS OF SOUTHERN CALIFORNIA  
MOUNTAINS AND OVER THE MOJAVE. A WETTER MODE IS EXPECTED WITH MAX  
PWATS NEAR 1.2 TO 1.3 INCHES AND LITTLE IN THE WAY OF STEERING FLOW.  
HOWEVER, CLOUD BASES ARE LIKELY TO BE OVER 3-KM WITH A HOT/DRY  
SUB-CLOUD LAYER LIMITING SOME PRECIPITATION EFFICIENCY. SPORADIC DRY  
STRIKES RE POSSIBLE GIVEN THE DEGREE OF EXTREME HEAT AND DRY FUELS  
BUT COVERAGE IS NOT EXPECTED TO REACH 10% OR GREATER. ADDITIONALLY,  
VERY HOT, DRY AND UNSTABLE CONDITIONS MAY SUPPORT PLUME DOMINATED  
FIRE BEHAVIOR WITH EXISTING LARGE FIRES.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page