509
FXUS66 KOTX 242041
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
141 PM PDT TUE MAR 24 2026
KEY MESSAGES
- CASCADE PASS SNOW: WINTRY TRAVEL CONDITIONS DEVELOP TONIGHT
THROUGH WEDNESDAY OVER THE CASCADES AS SNOW LEVELS DROP TO
BELOW PASS LEVELS.
- GUSTY WINDS: WINDS WILL RAMP UP THIS AFTERNOON THROUGH
WEDNESDAY WITH SOUTHWESTERLY GUSTS 25 TO 40 MPH.
- HYDROLOGY: THE STEHEKIN RIVER AT STEHEKIN IS FORECAST TO
REMAIN ABOVE ITS ACTION STAGE (19.5 FT) FOR THE NEXT WEEK.
OTHER AREA RIVERS WILL STAY ELEVATED BUT WILL REMAIN BELOW
ACTION STAGE.
SYNOPSIS
AN INCOMING LOW PRESSURE SYSTEM IS USHERING IN A PLUME OF
MOISTURE OFF OF THE PACIFIC, BRINGING WIDESPREAD PRECIPITATION
AND GUSTY SOUTHWESTERLY WINDS. A TRAILING COLD FRONT PUSHING
THROUGH THIS EVENING WILL DROP SNOW LEVELS BELOW MOUNTAIN
PASSES, RESULTING IN WINTRY TRAVEL CONDITIONS OVER THE CASCADES
TONIGHT THROUGH WEDNESDAY. HIGH PRESSURE RETURNS THURSDAY
THROUGH THE WEEKEND MAKING FOR A DRIER AND WARMER END TO THE
WEEK.
DISCUSSION
TODAY AND WEDNESDAY: PRECIPITABLE WATER VALUES ARE CURRENTLY
BETWEEN 200 AND 250 PERCENT OF NORMAL ACROSS THE INLAND
NORTHWEST COURTESY OF AN INCOMING LOW PRESSURE SYSTEM DIRECTING
AN ATMOSPHERIC RIVER AT THE REGION. WIDESPREAD RAINFALL IS BEING
OBSERVED WITH POCKETS OF SNOW IN THE VALLEYS ALONG THE EAST
SLOPES OF THE CASCADES. PRECIPITATION WILL CONTINUE INTO THIS
EVENING REGIONWIDE, THEN HEADING INTO THE OVERNIGHT HOURS A
COLD FRONT PASSAGE WILL DROP SNOW LEVELS FROM WEST TO EAST AND
USHER IN DRIER, MORE WESTERLY FLOW, PUTTING AN END TO
PRECIPITATION EVERYWHERE BUT THE CASCADES, NORTHERN WA
MOUNTAINS, AND ID PANHANDLE MOUNTAINS.
BETWEEN TONIGHT AND WEDNESDAY NIGHT, THE ID PANHANDLE LOWLANDS
HAVE A 50 TO 80 PERCENT CHANCE OF SEEING AT LEAST 0.50 INCHES OF
LIQUID, WHILE THESE CHANCES JUMP UP TO NEAR 100 PERCENT FOR
HIGHER ELEVATIONS. FOR EXTREME EASTERN WA (EAST OF A LINE FROM
METALINE FALLS TO PULLMAN) THERE IS A 30 TO 50 PERCENT CHANCE
FOR AT LEAST 0.50 INCHES OF PRECIP.
LOOKING AT SNOW ACCUMULATION, SNOW LEVELS WILL DROP TO AROUND
2000 FEET BEHIND THE COLD FRONT PASSAGE TONIGHT, TRANSITIONING
PRECIP TYPE AT MOUNTAIN PASSES FROM RAIN TO SNOW. SNOW WILL
CONTINUE OVER THE PASSES THROUGH WEDNESDAY AND INTO EARLY
THURSDAY, RESULTING IN WINTRY TRAVEL CONDITIONS AT TIMES.
THE 10TH PERCENTILE (LOW END) SNOW AMOUNT FORECAST FOR STEVENS
PASS IS 3 INCHES OVER THE COURSE OF THE EVENT, WHILE THE 90TH
PERCENTILE (HIGH END) AMOUNT IS 13 INCHES. HOW MUCH SNOW STEVENS
PASS ENDS UP GETTING WILL DEPEND LARGELY ON WHERE THE PUGET
SOUND CONVERGENCE ZONE SETS UP WEDNESDAY AFTERNOON. IF THE
CONVERGENCE ZONE SETS UP DIRECTLY OVER THE PASS, SNOW AMOUNTS
WILL LIKELY BE ON THE HIGH END OF THAT RANGE, WHILE IF THE
CONVERGENCE ZONE IS SLIGHTLY NORTH OR SOUTH OF THE PASS, SNOW
AMOUNTS WILL BE LOWER. LOOKOUT AND SHERMAN PASSES WILL SEE MUCH
LIGHTER ACCUMULATIONS OF AROUND AN INCH. SOME SPOTS IN THE
CASCADE VALLEYS INCLUDING MAZAMA AND WINTHROP HAVE SEEN A COUPLE
INCHES OF SNOW FALL SO FAR TODAY, BUT SNOW IN THESE VALLEYS
WILL TAPER OFF FOLLOWING THE COLD FRONT PASSAGE.
IN ADDITION TO SNOW, THIS SYSTEM WILL BRING GUSTY WINDS OUT OF
THE SOUTHWEST BETWEEN 25-40 MPH THIS AFTERNOON THROUGH
WEDNESDAY. HIGHEST GUSTS ARE FORECAST ACROSS THE COLUMBIA BASIN
AND OVER THE SPOKANE/PALOUSE AREAS. ONE LAST THING TO KEEP AN
EYE ON FOR WEDNESDAY AFTERNOON WILL BE SOME WEAK POST-FRONTAL
INSTABILITY. THE HREF DEPICTS 50-100 J/KG OF SURFACE CAPE
WEDNESDAY AFTERNOON OVER THE CASCADE CREST, NORTHERN MOUNTAINS,
AND ID PANHANDLE WHICH MAY BE ENOUGH TO TRIGGER A ROGUE
LIGHTNING STRIKE OR TWO.
THURSDAY THROUGH MONDAY: THE PATTERN TURNS DRIER AND WARMER
HEADING INTO NEXT WEEKEND AS A RIDGE OF HIGH PRESSURE BUILDS
IN BEHIND THE EXITING LOW. AFTER THURSDAY MORNING, PRECIPITATION
CHANCES DROP TO NEAR ZERO THROUGH SUNDAY. AFTERNOON HIGHS WILL
CLIMB INTO THE 50S AND 60S, THOUGH MOSTLY CLEAR SKIES WILL ALLOW
OVERNIGHT LOWS TO DIP INTO THE 20S AND 30S. ENSEMBLES HINT AT A
RIDGE BREAKDOWN EARLY NEXT WEEK, BUT FOR NOW, THE WEEKEND LOOKS
DRY AND CALM. /FEWKES
AVIATION
18Z TAFS: A MOIST FRONTAL SYSTEM PASSING THROUGH THE REGION
TODAY. RAIN WILL FILL IN AND INTENSIFY ACROSS THESE AREAS BY
MID AFTERNOON AFTER 21Z WITH MODERATE RAIN AND MVFR CONDITIONS
(BRIEF IFR CONDITIONS) AS THE TRAILING COLD FRONT PUSHES EAST OF
THE CASCADES. WINDS TODAY WITHIN THE WARM SECTOR WILL BE A BIT
TRICKY. SURFACE WINDS WILL BE SOUTHERLY THEN INCREASE AND VEER
SOUTHWESTERLY ALOFT. THERE WILL BE A BREAK IN THE RAIN INTO THE
EARLY AFTERNOON HOURS WITH SPORADIC GUSTS UP TO AROUND 20 KTS
ACROSS THE COLUMBIA BASIN (KMWH) TO SPOKANE (KGEG/KSFF) AND THE
PALOUSE (KPUW). GUSTS ARE EXPECTED TO SUBSIDE WITH RAIN LATE
THIS AFTERNOON WITH MODEST LOW LEVEL WIND SHEAR BETWEEN 21-03Z.
A COLD FRONT PASSAGE WILL THEN MIX DOWN WINDS AND INCREASE THE
POTENTIAL FOR GUSTS OF 20-25 KTS THIS EVENING. WINDS ARE
EXPECTED TO REMAIN BREEZY THROUGH TONIGHT INTO WEDNESDAY. LOW
STRATUS WITH MVFR CEILINGS WILL CONTINUE BEHIND THE COLD FRONT
WITHIN THE AREA OF KGEG TO KCOE AND SOUTH TO KPUW INTO WEDNESDAY
MORNING.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE FOR MVFR CONDITIONS AFTER 22Z AT KGEG/KSFF/KCOE-
KPUW WITH A 80% CHANCE FOR CEILINGS BELOW 3 KFT AGL, AND THERE
IS A 30% CHANCE FOR IFR CONDITIONS AT TIMES WITH THE RAIN
THROUGH 04Z. /SVH
-----------------------
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 38 51 28 47 28 55 / 80 10 20 0 0 0
COEUR D'ALENE 39 51 28 47 27 56 / 100 20 40 10 0 0
PULLMAN 41 49 28 44 29 55 / 100 40 20 0 0 0
LEWISTON 47 55 33 51 30 60 / 100 50 20 0 0 0
COLVILLE 35 53 27 50 26 55 / 60 20 30 0 0 0
SANDPOINT 38 47 28 43 27 53 / 100 40 60 30 0 0
KELLOGG 41 48 29 42 29 55 / 100 40 70 20 0 0
MOSES LAKE 36 56 30 54 29 60 / 20 10 10 0 0 0
WENATCHEE 38 51 32 51 32 55 / 10 20 10 0 0 0
OMAK 35 50 28 47 30 56 / 20 20 10 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 5 AM PDT
THURSDAY FOR WESTERN CHELAN COUNTY-WESTERN OKANOGAN
COUNTY.
ID...NONE.
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