498  
FNUS21 KWNS 031700  
FWDDY1  
 
DAY 1 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1200 PM CDT THU JUL 03 2025  
 
VALID 031700Z - 041200Z  
   
..CENTRAL CALIFORNIA  
 
AN APPROACHING MID-LEVEL SHORT WAVE TROUGH WILL PROMOTE ENHANCED DRY  
DOWNSLOPE WINDS ALONG AND LEEWARD OF THE DIABLO RANGE INTO THE SAN  
JOAQUIN VALLEY THIS AFTERNOON. WEST-NORTHWEST WINDS OF 10-15 MPH  
WITH LOCALLY SUSTAINED 20 MPH COMBINED WITH RELATIVE HUMIDITY AS LOW  
AS 10% WILL SUPPORT A FEW HOURS OF ELEVATED FIRE WEATHER CONDITIONS  
AMID DRY FUELS.  
   
..NORTHERN GREAT BASIN AND UPPER-COLORADO RIVER BASIN  
 
ISOLATED DRY THUNDERSTORM THREAT WAS EXPANDED INTO SOUTH-CENTRAL OR  
AND NORTH-CENTRAL NV WITH LATEST MODEL GUIDANCE AND OBSERVED  
SOUNDINGS INDICATING PRECIPITABLE WATER VALUES HOLDING IN THE  
0.50-0.80 INCH RANGE FOR THIS AFTERNOON. THE ADVANCING SHORT-WAVE  
TROUGH WILL SUPPORT FASTER STORM MOTIONS PARTICULARLY ACROSS  
SOUTHEASTERN OR. IN ADDITION, FALLING 500 DM HEIGHTS AND MID-LEVEL  
JET SUPPORT WILL KEEP A NOCTURNAL THUNDERSTORM THREAT FOR  
SOUTHEASTERN OR AND SOUTHERN IDAHO THROUGH 12Z FRIDAY. OTHERWISE, A  
MIX OF WET/DRY THUNDERSTORMS ACROSS THE UPPER CO RIVER BASIN AND  
CENTRAL MOUNTAINS OF UT COULD SUPPORT NEW IGNITIONS IN POCKETS OF  
EXISTING DRY FUELS.  
 
..WILLIAMS.. 07/03/2025  
   
PREV DISCUSSION  
/ISSUED 0211 AM CDT THU JUL 03 2025/  
   
..SYNOPSIS  
 
A COMPACT SHORTWAVE TROUGH MOVING ACROSS NORTHERN CA WILL ACCOMPANY  
40-50 KT WESTERLY FLOW ACROSS THE NORTHERN GREAT BASIN. THIS WILL  
ENCOURAGE DRY DOWNSLOPE FLOW ACROSS PARTS OF WESTERN NV AND THE  
NORTHERN GREAT BASIN. AT THE SAME TIME, CONTINUED MONSOON MOISTURE  
WILL ALLOW SCATTERED SHOWERS AND THUNDERSTORMS OVER THE  
INTERMOUNTAIN WEST WITH ISOLATED LIGHTNING.  
   
..NORTHERN GREAT BASIN  
 
DRY AND BREEZY CONDITIONS ARE EXPECTED TODAY AND TONIGHT IN THE LEE  
OF THE SIERRA AND NORTHERN GREAT BASIN AHEAD OF THE SHORTWAVE  
TROUGH. SUSTAINED 15-20 MPH SURFACE WINDS ARE EXPECTED FROM THE  
WEST/SOUTHWEST THROUGH THE DAY. A DRY AND DEEP BOUNDARY LAYER WILL  
ALSO SUPPORT RH BELOW 15-20%. DESPITE SOME RECENT RAINFALL, AREA  
FUELS REMAIN RECEPTIVE ACROSS MUCH OF NV AND THE NORTHERN GREAT  
BASIN. WIDESPREAD ELEVATED AND LOCALLY CRITICAL FIRE-WEATHER  
CONDITIONS ARE LIKELY.  
   
..DRY THUNDER  
 
AS THE UPPER TROUGH MOVES INTO THE WEST, MONSOON MOISTURE WILL BE  
SHUNTED EASTWARD COMPARED TO THE LAST SEVERAL DAYS. STILL, PWATS  
AROUND 0.6-0.8 INCHES ACROSS WESTERN CO AND INTO THE NORTHERN  
ROCKIES WILL BE SUFFICIENT TO SUPPORT SCATTERED SHOWERS AND  
THUNDERSTORMS THIS AFTERNOON AND EVENING. FUEL RECEPTIVENESS HAS  
DECREASED WITH MULTIPLE ROUNDS OF SHOWERS AND STORMS THIS WEEK.  
STILL, DRIER POCKETS REMAIN AND LIGHTNING OUTSIDE OF THE HEAVIER  
PRECIPITATION CORES WILL BE CAPABLE OF IGNITIONS. THIS APPEARS MOST  
LIKELY OVER PARTS OF NORTHERN CO TO EASTERN ID, WHERE LESS RAINFALL  
HAS BEEN OBSERVED. WILL MAINTAIN ISODRYT HIGHLIGHTS FOR OCCASIONAL  
LIGHTING STRIKES WITHIN RECEPTIVE FUELS.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT  
 
 
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