084
FNUS22 KWNS 201926
FWDDY2
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0225 PM CDT THU AUG 20 2026
VALID 211200Z - 221200Z
THE EXISTING ISOLATED DRY THUNDERSTORM AREA WAS MOVED FARTHER WEST
IN AGREEMENT WITH THE LATEST FORECAST GUIDANCE. WHILE SOME THREAT
EXISTS DURING THE DAY ON FRIDAY NEAR THE CASCADE CREST, THE BEST
POTENTIAL, ESPECIALLY FARTHER NORTH IN WESTERN WA, WILL OCCUR AFTER
06Z (EARLY SATURDAY MORNING). GIVEN THE SLOWER PROGRESSION OF THE
TROUGH AS DEPICTED IN RECENT FORECAST GUIDANCE AND THE HEAVY AND DRY
(ERCS ABOVE THE 80-90TH PERCENTILE) FUEL LOADING OVER THE OLYMPIC
PENINSULA, THAT AREA WAS ADDED INTO THE ISOLATED DRY THUNDER AREA ON
DAY 2/FRIDAY AS WELL. NO CHANGES WERE MADE TO THE EXISTING ELEVATED
WIND/RH AREA. SOME UNCERTAINTY REMAINS AS TO HOW PERSISTENT THE
CLOUDS MAY BE, WHICH COULD KEEP BOTH AFTERNOON WINDS SLIGHTLY LOWER
AND RHS SLIGHTLY HIGHER. EVEN SO, THE LATEST FORECAST GUIDANCE STILL
MAINTAINS ELEVATED CRITERIA GIVEN THE DRY ENVIRONMENT AND TIGHTENED
PRESSURE GRADIENT.
..STEARNS.. 08/20/2026
PREV DISCUSSION
/ISSUED 1242 AM CDT THU AUG 20 2026/
..SYNOPSIS
THE ESTABLISHED UPPER RIDGE OVER THE GREAT BASIN WILL CONTINUE TO
AMPLIFY AS AN UPPER TROUGH STRENGTHENS ALONG THE WEST COAST ON DAY
2/FRIDAY. A MID-LEVEL LOW PRESSURE SYSTEM WILL NEAR THE PACIFIC
NORTHWEST COAST AS THE UPPER-LEVEL JET MAX PEAKS OVER
SOUTHERN/CENTRAL OREGON, PROVIDING A FAVORABLE SETUP FOR
THUNDERSTORMS ALONG/EAST OF THE CASCADES. FARTHER SOUTH, INCREASING
SOUTHWESTERLY FLOW OVER THE WESTERN GREAT BASIN WILL PROMOTE GUSTY
SURFACE WINDS WITHIN A WARM AND DRY AIRMASS, YIELDING ELEVATED FIRE
WEATHER CONCERNS.
..CENTRAL-EASTERN OREGON/WASHINGTON
AS THE MID-LEVEL LOW NEARS THE OREGON/WASHINGTON COASTLINE, SYNOPTIC
SCALE FORCING WILL OVERSPREAD THE PACIFIC NORTHWEST LATE
AFTERNOON/OVERNIGHT. AS A RESULT OF AFTERNOON VERTICAL MIXING, SOME
ISOLATED DRY THUNDERSTORMS ARE POSSIBLE (5-15% CHANCE) BEFORE BETTER
MOISTURE IS USHERED IN BY THE UPPER TROUGH LATE EVENING. HOWEVER,
WIDESPREAD CLOUD COVER DURING THE DAY MAY INHIBIT SOLAR INSOLATION,
THUS LIMITING GREATER INSTABILITY. WHILE SOME TIMING DISPARITY IS
PORTRAYED IN RECENT GUIDANCE ON THE APPROACH OF THE UPPER TROUGH,
THE OVERALL PATTERN IS FAVORABLE FOR THUNDERSTORM POTENTIAL
OVERNIGHT. FORECAST SOUNDINGS DEPICT 0.8-1.0" PWATS, 30-35 KT LCL-EL
WINDS, AND A DRY SUB-CLOUD LAYER, INDICATING HIGHER RAINFALL
ACCUMULATION WILL LIKELY REMAIN LOCALIZED (OR WITHIN AREAS THAT SEE
MULTIPLE ROUNDS OF STORMS). A DROUGHT-STRESSED AND RECENTLY
RECEPTIVE FUEL ENVIRONMENT WILL RAISE CONCERNS FOR NEW LIGHTNING
IGNITIONS; THUS, AN ISOLATED DRY THUNDERSTORM RISK AREA WAS
INTRODUCED ACROSS THE REGION TO CAPTURE THE EXPANSE OF THUNDERSTORM
POTENTIAL IN THE AFTERNOON AND THE OVERNIGHT HOURS. HIGHLIGHTS MAY
NEED TO BE CONFINED IN FUTURE OUTLOOKS AS THE PATTERN IS BETTER
RESOLVED.
...NORTHEASTERN CALIFORNIA, NORTHWESTERN NEVADA, AND SOUTHERN
OREGON...
DAYTIME HIGH TEMPERATURES WILL BE SLIGHTLY COOLER ON DAY 2/FRIDAY AS
COMPARED TO PREVIOUS DAYS, BUT WILL STILL RANGE FROM 90-100 F. AT
PEAK HEATING, SUSTAINED SOUTHWESTERLY WINDS OF 10-15 MPH (GUSTS UP
TO 25 MPH) AND 10-15% RH WILL ALLOW ELEVATED FIRE WEATHER CONDITIONS
TO EVOLVE WHERE FUELS HAVE GROWN INCREASINGLY MORE RECEPTIVE.
..PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT
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