110
FXUS66 KOTX 220501
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1001 PM PDT WED OCT 21 2026
KEY MESSAGES
- HIGH CONFIDENCE FOR RAIN ACROSS FAR EASTERN WASHINGTON AND
NORTHERN IDAHO THURSDAY AFTERNOON THROUGH FRIDAY MORNING.
- DRY AND WINDY FRIDAY OKANOGAN VALLEY, WATERVILLE PLATEAU, AND
UPPER COLUMBIA BASIN LEADING TO ELEVATED FIRE WEATHER
CONDITIONS WITH POTENTIAL FOR PATCHY BLOWING DUST
- COOLER TEMPERATURES FRIDAY INTO THE WEEKEND
SYNOPSIS
RAIN WILL INCREASE OVER THE EASTERN THIRD OF WASHINGTON INTO
NORTH IDAHO BY THURSDAY EVENING AND CONTINUE INTO EARLY FRIDAY.
CENTRAL WASHINGTON WILL MISS OUT ON THE RAIN, WHICH COMBINED
WITH DRY AND WINDY CONDITIONS ON FRIDAY WILL LEAD TO ELEVATED
FIRE WEATHER CONDITIONS AND THE POTENTIAL FOR PATCHY BLOWING
DUST. COOLER WEATHER IS EXPECTED FRIDAY INTO THE WEEKEND.
DISCUSSION
THURSDAY THROUGH FRIDAY: A LOW OFF THE CALIFORNIA COAST WILL
EJECT NORTHEAST INTO CALIFORNIA, NEVADA AND SOUTHERN IDAHO. WHILE
THE SYSTEM IS PASSING WELL TO OUR SOUTH, SOME OF THIS MOISTURE
GETS PICKED UP BY AN INCOMING UPPER TROUGH FROM THE WEST, WITH
PRECIPITABLE WATER VALUES INCREASING TO 175-200 PERCENT OF NORMAL
ACROSS THE EASTERN THIRD OF WASHINGTON INTO THE IDAHO PANHANDLE.
THIS WILL TRANSLATE TO A BAND OF RAIN MOVING INTO THE REGION, WITH
MODELS TRENDING WETTER WITH RAIN AMOUNTS OF 0.10-0.30 INCHES FROM
THE BLUE MOUNTAINS AND PALOUSE NORTHWARD ACROSS THE SPOKANE AREA,
NORTHEAST MOUNTAINS, AND ID PANHANDLE. ALSO AIDING IN
PRECIPITATION WILL BE MID LEVEL INSTABILITY WITH 700-500MB MU CAPE
VALUES OF 50-100 J/KG. TIMING OF RAIN FOR EASTERN WA IS MAINLY
DURING THE AFTERNOON AND EVENING HOURS, BECOMING MORE CONFINED TO
THE IDAHO PANHANDLE OVERNIGHT INTO EARLY FRIDAY. AS THE TROUGH
AXIS MOVES OVER THE REGION TONIGHT, COOLER AND DRIER AIR MOVES
INTO CENTRAL WA AS A COLD FRONT PASSES. THE DRY AIR REALLY BECOMES
NOTEWORTHY FRIDAY AFTERNOON AS PRECIPITABLE WATER VALUES PLUMMET
TO 25-50 PERCENT OF NORMAL. THIS COMBINED WITH BREEZY NORTH-
NORTHWEST WINDS (LOCALLY WINDY DOWN THE OKANOGAN VALLEY AND
WATERVILLE PLATEAU) WILL PROMOTE ELEVATED FIRE WEATHER CONDITIONS
AND THE POTENTIAL FOR PATCHY BLOWING DUST. WINDS EASE FRIDAY
NIGHT, AND WITH THE VERY DRY AIR OVER THE REGION RADIATIONAL
COOLING WILL BE STRONG, WITH FREEZING TEMPERATURES FOR MOST
(EXCEPT LOCALLY AROUND WENATCHEE), WITH THE COLDER POCKETS SUCH AS
REPUBLIC AND DEER PARK FALLING INTO THE LOW 20S.
SATURDAY THROUGH WEDNESDAY: ENSEMBLES TO CONTINUE TO STRUGGLE
WITH A LOW THAT STRENGTHENS OFF THE SOUTHERN BC COAST ON SATURDAY
AND THEN WHAT HAPPENS AFTER THAT. 45 PERCENT OF THE CLUSTERS
POSITION THE LOW BY MONDAY NEAR THE WA COAST FOR COOLER AND
SHOWERY WEATHER, ESPECIALLY NEAR THE CASCADES. 20 PERCENT TAKE THE
LOW DIRECTLY OVER THE REGION FOR MUCH COOLER AND WIDESPREAD
SHOWERY WEATHER, AS WELL AS MOUNTAIN SNOW. THE REMAINING 35
PERCENT HAVE THE LOW MUCH FURTHER WEST AND MAINTAIN HIGH PRESSURE
OVER THE REGION. GIVEN THE UNCERTAINTY NOT TOO MANY CHANGES TO
THIS PART OF THE FORECAST WHICH CURRENTLY PROVIDES A MIDDLE GROUND
OF THE MODEL SOLUTIONS WITH NEAR SEASONAL TEMPERATURES WITH HIGHS
MAINLY IN THE 50S AND A 20-30 PERCENT CHANCE OF SHOWERS. BUT WITH
A 10-15 DEGREE RANGE BETWEEN THE NBM 10TH AND 90TH PERCENTILES
THERE IS LOW CONFIDENCE IN THE FORECAST DETAILS. WASHINGTON PASS
SUNDAY AND SUNDAY NIGHT HAS A 20 PERCENT CHANCE OF 1 INCH OR MORE
OF SNOW. JW
AVIATION
00Z TAFS: DRY WEATHER CONTINUES FOR TONIGHT WITH PASSING MID AND
HIGH CLOUDS. THEN MOISTURE INCREASES FROM THE SOUTHWEST OVER THE
EASTERN THIRD OF WASHINGTON INTO THE IDAHO PANHANDLE MAINLY
AFTER 18Z THURSDAY WITH RAIN SHOWERS SPREADING INTO KPUW/KLWS IN
THE AFTERNOON, AND THEN UP INTO KGEG/KSFF/KCOE DURING THE LATE
AFTERNOON AND EVENING. VFR CONDITIONS ARE EXPECTED WITH THESE
SHOWERS, ALTHOUGH WITH ELEVATED INSTABILITY THERE IS THE
POTENTIAL FOR MODERATE RAIN EMBEDDED WHICH COULD BRIEFLY LOWER
VISIBILITY TO MVFR.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
IN VFR CONDITIONS THROUGH 20Z THURSDAY. THEN EMBEDDED MODERATE
RAIN WITHIN SHOWERS FOR KLWS/KPUW COULD BRIEFLY LOWER VISIBILITY
TO MVFR BUT CONFIDENCE TOO LOW TO INCLUDE THIS IN TAF FORECAST.
JW
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CONFIDENCE DESCRIPTORS:
LOW - LESS THAN A 30 PERCENT CHANCE
MODERATE - 30 TO 70 PERCENT CHANCE
HIGH - GREATER THAN A 70 PERCENT CHANCE
FOR ADDITIONAL PROBABILISTIC INFORMATION FOR NWS SPOKANE
AIRPORTS, PLEASE REFER TO THE AVIATION DASHBOARD ON OUR
WEBPAGE: HTTPS:/WWW.WEATHER.GOV/OTX/AVNDASHBOARD
PRELIMINARY POINT TEMPS/POPS
SPOKANE 40 65 41 60 32 56 / 0 20 80 0 0 0
COEUR D'ALENE 41 67 43 57 34 56 / 0 20 90 10 0 0
PULLMAN 42 63 40 52 28 54 / 0 40 90 10 0 0
LEWISTON 46 65 47 58 35 59 / 0 50 100 30 0 0
COLVILLE 32 68 35 61 23 57 / 0 0 60 0 0 0
SANDPOINT 38 67 44 57 31 55 / 0 10 90 20 10 0
KELLOGG 43 70 43 50 32 54 / 0 20 100 50 0 0
MOSES LAKE 35 64 37 65 27 58 / 0 20 10 0 0 0
WENATCHEE 44 67 42 63 36 57 / 0 0 0 0 0 0
OMAK 36 68 41 62 29 57 / 0 0 0 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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