635
FXUS66 KOTX 120535
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1035 PM PDT SAT OCT 11 2025
KEY MESSAGES
- MODERATE TO HEAVY SNOW FOR THE MOUNTAINS SUNDAY INTO MONDAY
MORNING.
- GUSTY NORTH TO NORTHEAST WINDS ON MONDAY. COLD WIND CHILLS IN
THE TEENS TO SINGLE DIGITS IN THE MOUNTAINS.
- BELOW NORMAL TEMPERATURES SUNDAY INTO EARLY NEXT WEEK WITH
HIGHS IN THE 50S. LOW TEMPERATURES DROPPING INTO THE 20S AND
30S BY TUESDAY.
SYNOPSIS
RAIN WILL CONTINUE OVER MUCH OF EXTREME EASTERN WASHINGTON INTO
THE IDAHO PANHANDLE TONIGHT. HEAVY SNOW WITH WINTER CONDITIONS
IS EXPECTED IN THE CASCADES AND NORTHERN MOUNTAINS ABOVE 3000
FEET SUNDAY INTO MONDAY. DRY WEATHER WITH FALL LIKE TEMPERATURES
ARE EXPECTED TUESDAY THROUGH THURSDAY.
DISCUSSION
...EARLY SEASON WINTER STORM TO BRING MODERATE TO HEAVY SNOW TO THE
CASCADES, NORTHERN MOUNTAINS OF EASTERN WASHINGTON AND NORTH IDAHO...
TONIGHT: A TROUGH OF LOWER PRESSURE PUSHING ACROSS THE INLAND
NORTHWEST WILL BRING LIGHT PRECIPITATION THROUGH TONIGHT. ADDITIONAL
ENERGY DIVING SOUTH ACROSS BC WILL REINFORCE THE MOIST ISENTROPIC
ASCENT ACROSS THE EASTERN HALF OR SO OF THE FORECAST AREA TONIGHT.
SNOW LEVELS WILL ALSO BEGIN TO DROP OVERNIGHT DOWN TO BETWEEN 3000-
4000 OVER THE CASCADES AND THE NORTHERN MOUNTAINS. WE WILL
START TO SEE LIGHT SNOW FOR THOSE HIGHER ELEVATIONS PARTICULARLY
CLOSER TO THE CASCADE CREST. THE IDAHO PANHANDLE WILL SEE UP TO
A QUARTER OF AN INCH TO UP TO A HALF OF AN INCH OF PRECIPITATION
FOR THOSE MORE FAVORED HIGHER ELEVATIONS WHERE OROGRAPHICS HELP
GENERATE LIFT. EXPECT LOW CLOUDS AND A DAMP MORNING ON SUNDAY
ESPECIALLY FOR THE EASTERN HALF OF THE FORECAST AREA. WINDS WILL
REMAIN BREEZY, BUT HIGHER GUSTS WILL GENERALLY DIE OFF
OVERNIGHT.
SUNDAY THROUGH MONDAY: BIGGER IMPACTS ARE ANTICIPATED WITH A SECOND
UPPER LEVEL LOW THAT DEEPENS ACROSS WESTERN WASHINGTON.
MODELS REMAIN IN GOOD AGREEMENT WITH A SURFACE LOW SPINNING UP OVER
NORTHWEST WASHINGTON SUNDAY AFTERNOON AND CONTINUING TO DEEPEN AS IT
TRACKS DOWN THE WESTERN WASHINGTON COASTLINE. THIS WILL DO TWO
THINGS: (1) TIGHTEN THE NORTHERLY PRESSURE GRADIENT WITH COLD
CANADIAN AIR ADVANCING INTO THE REGION, AND (2) DRAW MOISTURE
NORTHWARD ACROSS THE REGION THAT OVERRUNS THE ADVANCING COLD AIR.
ADVECTION OF COLDER CANADIAN AIR WILL DROP SNOW LEVELS FURTHER
SUNDAY NIGHT. SNOW WILL ACCUMULATE FURTHER DOWN IN ELEVATION THROUGH
THE NIGH ON SUNDAY WITH THE NORTHERN LOCATIONS SUCH AS REPUBLIC,
NORTHPORT, SANDPOINT, BONNERS FERRY, PORTHILL, AND EASTPORT
PICKING UP AT LEAST A DUSTING. WARM ROAD TEMPERATURES MAY MAKE
IT DIFFICULT FOR SNOW TO ACCUMULATE INITIALLY, BUT THESE
TEMPERATURES ARE EXPECTED TO DROP OVERNIGHT SUNDAY. STRONG
DYNAMICS AND VERTICAL LIFT IN THE SNOW GROWTH ZONE MAY ALSO PUSH
SNOW LEVELS DOWN MORE SO THAN MODELS ARE LETTING ON. THE EAST
SLOPES OF THE CASCADES WILL BE FAVORED FOR HIGHER INTENSITY
SNOWFALL SOUTH OF LAKE CHELAN WITH NORTH-NORTHEAST WINDS
RESULTING IN FAVORABLE UPSLOPE FLOW INTO THIS AREA. THIS WILL BE
PARTICULARLY SO INTO MISSION RIDGE WHERE BURST OF HEAVY SNOW IS
POSSIBLE. A BIG CONCERN WILL BE FOR ANY BACKCOUNTRY
RECRATIONALISTS CAMPING IN THE MOUNTAINS THIS WEEKEND. WEATHER
CONDITIONS WILL DETERIORATE RAPIDLY PARTICULARLY LATE ON SUNDAY.
EXPECT WINTER CONDITIONS AND COLD TEMPERATURES. MOUNTAIN PASSES
WILL ALSO SEE THE POTENTIAL FOR SNOW COVERED ROADS AND HEAVY AT
TIMES FOR WASHINGTON PASS AND SHERMAN PASS; HOWEVER, LOUP LOUP
PASS, STEVENS PASS, AND BLEWETT PASS WILL ALSO SEE THE POTENTIAL
FOR SNOW TRAVEL. BELOW ARE THE PROBABILITIES FOR SNOWFALL
THRESHOLDS OF AT LEAST 2", 4", AND 8" AT OUR MOUNTAIN PASSES:
MOUNTAIN PASS CHANCE OF 2+" CHANCE OF 4+" CHANCE OF 8+"
WASHINGTON 95% 90% 60%
SHERMAN 100% 85% 30%
LOOKOUT 80% 45% 5%
STEVENS 95% 80% 45%
BLEWETT 90% 70% 20%
LOUP LOUP 85% 50% 5%
NORTH TO NORTHEAST WINDS WILL ALSO BE GUSTY, ESPECIALLY DOWN THE
OKANOGAN VALLEY, PURCELL TRENCH AND ACROSS THE COLUMBIA BASIN.
THE ECMWF ENSEMBLE HAS A MEAN WIND GUST SPEED OF 40 MPH AT
SANDPOINT FOR MONDAY. THE GUSTY WINDS AND COLD AIR IS EXPECTED
TO PRODUCE CHILLY WIND CHILLS IN THE SINGLE DIGITS IN THE
MOUNTAINS. WIND CHILLS IN THE TEENS CAN BE EXPECTED IN THE
MOUNTAINS IN THE CASCADES AND ACROSS THE NORTHERN MOUNTAINS OF
EASTERN WASHINGTON. THE COMBINATION OF CHANGING WEATHER
CONDITIONS TO SNOW AND THEN ADD THE BITTERLY COLD WIND WILL MAKE
FOR DANGEROUS WINTER CONDITIONS FOR ANYONE IN THE BACKCOUNTRY
THAT IS PREPARED. THE WINTER STORM WATCH HAS BEEN UPGRADED TO A
WINTER STORM WARNING IN NORTH IDAHO ABOVE 3,000 FEET. SNOW
ACCUMULATIONS DON'T LOOK TO MEET WARNING CRITERIA FOR THE REST
OF THE HIGHER TERRAIN AND WINTER WEATHER ADVISORIES HAVE BEEN
ISSUED INSTEAD. THERE IS POTENTIAL FOR HEAVY SNOW ACCUMULATION
ACROSS THE HIGHER TERRAIN OF CHELAN COUNTY ESPECIALLY AS
TEMPERATURES COOL AND SNOW RATIOS INCREASE EARLY MONDAY MORNING,
BUT NOT CONFIDENT ENOUGH THAT SNOW WILL BE HEAVY ENOUGH TO
WARRANT A WINTER STORM WARNING. WIND GUSTS ON MONDAY WILL RANGE
FROM BETWEEN 30-40 MPH FOR THE OKANOGAN VALLEY, PURCELL TRENCH,
AND COLUMBIA BASIN. /SVH
MONDAY NIGHT THROUGH THURSDAY: A QUIETER PATTERN RETURNS AS THE
LOW DROPS SOUTH OVER CALIFORNIA AND AN UPPER RIDGE BUILDS OFF
THE COAST PROVIDING A DRY NORTH TO NORTHWEST FLOW OVER THE
INLAND NORTHWEST. IT WILL FEEL LIKE FALL AS LOW TEMPERATURES
DROP INTO THE 20S AND 30S FOR MOST OF THE REGION, AND DAYTIME
HIGHS IN THE MID 50S TO LOW 60S.
BY FRIDAY, 85% OF THE ENSEMBLES SHOWS ANOTHER SYSTEM DROPPING
IN FROM THE NORTHWEST BUT DIFFER WITH THE STRENGTH. 40% SHOW A
WINDY AND WET SCENARIO WHILE 45% SHOW A WEAKER TROUGH. FORECAST
CURRENTLY LEANS TOWARDS THE WEAKER SCENARIO BUT THIS WILL
CONTINUE TO BE MONITORED IN THE COMING DAYS. JW
AVIATION
06Z TAFS: STEADY LIGHT RAIN WILL CONTINUE OVER THE ID PANHANDLE
TONIGHT, DECREASING AND COMING TO AN END FOR THE SPOKANE AREA
OVERNIGHT. A MOIST BOUNDARY LAYER WILL LEAD TO AREAS OF MVFR
CONDITIONS IN THE ID PANHANDLE, WITH MAINLY VFR CONDITIONS FOR
CENTRAL AND EASTERN WA TONIGHT. ON SUNDAY AS THE NEXT WEATHER
SYSTEM MOVES IN WIDESPREAD RAIN DEVELOPS, WITH WIDESPREAD MVFR
CONDITIONS, AND EVEN LOCALIZED IFR CONDITIONS OVER NE WASHINGTON
AND THE NORTH ID PANHANDLE. WINDS WILL SWITCH ACROSS THE REGION
SUNDAY AFTERNOON AND EVENING, AS SOUTHWEST WINDS BECOME
NORTHEAST AS A STRENGTHENING LOW PRESSURE SYSTEM DEVELOPS ALONG
THE WASHINGTON COAST. THIS WILL IMPACT BOUNDARY LAYER MOISTURE
CONDITIONS, WITH MOISTENING SUNDAY EVENING FOR KEAT/KMWH WITH
LOWERING CIGS, WHILE CIGS MAY RISE SOME FOR KPUW/KLWS DUE TO
DOWNSLOPE SOUTHEAST BOUNDARY LAYER WINDS.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
IN CIGS LOWERING TO AT LEAST MVFR FOR KGEG/KSFF/KCOE/KPUW SUNDAY
MORNING AS RAIN DEVELOPS. JW
-----------------------
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:/WEATHER.GOV/OTX/AVNDASHBOARD
PRELIMINARY POINT TEMPS/POPS
SPOKANE 41 48 35 49 31 55 / 80 90 90 20 0 0
COEUR D'ALENE 41 47 34 49 31 55 / 90 90 100 10 10 0
PULLMAN 41 45 39 52 31 55 / 90 90 90 20 10 10
LEWISTON 47 53 44 59 39 58 / 90 80 80 20 10 10
COLVILLE 35 48 32 50 19 56 / 90 90 100 20 0 0
SANDPOINT 40 45 32 46 25 53 / 100 90 100 10 10 0
KELLOGG 40 45 32 46 32 53 / 100 100 100 20 10 10
MOSES LAKE 43 53 40 54 34 58 / 20 70 90 60 0 0
WENATCHEE 44 51 37 50 36 57 / 40 80 90 80 0 0
OMAK 42 51 37 55 33 59 / 60 80 90 30 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY FROM 5 PM SUNDAY TO 5 AM PDT MONDAY
FOR NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS.
WINTER WEATHER ADVISORY FROM 8 AM SUNDAY TO 11 AM PDT MONDAY
FOR CENTRAL CHELAN COUNTY-WESTERN CHELAN COUNTY-WESTERN
OKANOGAN COUNTY.
ID...WINTER STORM WARNING FROM 2 PM SUNDAY TO 5 AM PDT MONDAY FOR
NORTHERN PANHANDLE.
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