106  
FNUS21 KWNS 181622  
FWDDY1  
 
DAY 1 FIRE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1121 AM CDT SAT JUL 18 2026  
 
VALID 181700Z - 191200Z  
 
THE FORECAST REMAINS ON TRACK FOR ELEVATED FIRE WEATHER CONDITIONS  
ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND THE NORTHERN HIGH  
PLAINS TODAY. CURRENT (16Z) OBSERVATIONS DEPICT RH VALUES QUICKLY  
PLUMMETING BENEATH MOSTLY CLEAR SKIES -- APART FROM AREAS OF DENSE  
SMOKE IN CENTRAL-EASTERN OR/WA -- AND A FEW WIND GUSTS OF 20+ MPH IN  
TERRAIN-FAVORED AREAS. THIS AFTERNOON, HIGH TEMPERATURES ACROSS THE  
RISK AREAS WILL APPROACH 90-95 DEGREES (LOCALLY HIGHER) YIELDING  
BETTER BOUNDARY LAYER MIXING, ALLOWING FOR RH VALUES TO DECLINE TO  
LESS THAN 20% AMID SUSTAINED WINDS OF 10-15 MPH (WEST-SOUTHWESTERLY  
IN THE NORTHWEST, SOUTHEASTERLY IN THE NORTHERN HIGH PLAINS).  
DESPITE SEVERAL DAYS OF THUNDERSTORMS ACROSS OR/WA/ID, FUELS REMAIN  
VERY DRY WITH ERCS AT OR ABOVE THE 90TH PERCENTILE. COMBINED  
METEOROLOGICAL CONDITIONS AND A DRY FUELSCAPE WILL PROMOTE AN  
ELEVATED FIRE RISK, ESPECIALLY IN THE NORTHWEST WHERE AN ABUNDANCE  
OF LIGHTNING STRIKES OVER THE LAST SEVERAL DAYS HAS LED TO THE  
EMERGENCE OF NUMEROUS WILDFIRES.  
 
..ELIZALDE-GARCIA.. 07/18/2026  
   
PREV DISCUSSION  
/ISSUED 1250 AM CDT SAT JUL 18 2026/  
   
..SYNOPSIS  
 
ALONG THE NORTHWESTERN PERIPHERY OF AN EXPANSIVE UPPER RIDGE OVER  
THE WEST, A MIDLEVEL TROUGH WILL ADVANCE EASTWARD ACROSS BC AND THE  
NORTHWEST DURING THE DAY. WITHIN THE BASE OF THE TROUGH, STRONG  
MIDLEVEL SOUTHWESTERLY FLOW WILL OVERSPREAD WA, OR, NORTHERN CA, AND  
NORTHWEST NV. ASSOCIATED DOWNSLOPE FLOW IN THE LEE OF THE CASCADES  
AND NORTHERN SIERRA WILL AID IN DEEP BOUNDARY-LAYER MIXING INTO THE  
STRENGTHENING FLOW ALOFT. THIS WILL YIELD A BROAD AREA OF 15 MPH  
SUSTAINED WEST-SOUTHWESTERLY SURFACE WINDS (WITH HIGHER GUSTS) AMID  
10-15 PERCENT RH. LOCALLY STRONGER SURFACE WINDS CAN BE EXPECTED IN  
TERRAIN-FAVORED/GAP-FLOW AREAS THROUGH THE CASCADES. GIVEN  
DRY/RECEPTIVE FUELS ACROSS REGION, ELEVATED FIRE-WEATHER CONDITIONS  
ARE EXPECTED.  
 
FARTHER EAST, LEE TROUGHING OVER THE NORTHERN HIGH PLAINS WILL  
PROMOTE 10-15 MPH SUSTAINED EASTERLY SURFACE WINDS ACROSS PARTS OF  
SOUTHEASTERN WY DURING THE AFTERNOON. THESE WINDS, COMBINED WITH  
15-20 PERCENT RH AND DRY FUELS, WILL FAVOR ELEVATED FIRE-WEATHER  
CONDITIONS.  
   
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT  
 
 
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