445
FXUS66 KOTX 130104
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
604 PM PDT THU MAR 12 2026
KEY MESSAGES
- HEAVY RAIN OVER THE PALOUSE INTO LEWISTON-CLARKSTON VALLEY AND
CAMAS PRAIRIE WILL INCREASE THE RISK OF SMALL STREAM FLOODING.
- POTENTIAL FOR HEAVY WET SNOW POSSIBLE IN THE VALLEYS OF
NORTHEAST WASHINGTON INTO THE NORTHERN PANHANDLE FOR FRIDAY
MORNING. THIS MAY LEAD TO IMPACTS TO THE FRIDAY MORNING
COMMUTE.
- MODERATE TO HEAVY MOUNTAIN SNOW THIS WEEK OVER THE CASCADES
AND NORTH IDAHO MOUNTAIN PASSES.
SYNOPSIS
A WET WEATHER SYSTEM WILL BE SITUATED OVER THE INLAND NORTHWEST
THROUGH FRIDAY. MODERATE TO HEAVY PRECIPITATION WITH RAIN AND A
MIX OF RAIN AND SNOW IN THE VALLEYS. RAIN OVER THE PALOUSE INTO
THE SOUTHERN IDAHO PANHANDLE WILL LEAD TO RISES ON RIVERS AND
SMALL STREAMS. A TRANSITION TO SNOW FOR NORTHERN VALLEYS IN
NORTHEAST WASHINGTON INTO THE NORTHERN PANHANDLE MAY LEAD TO
TRAVEL IMPACTS IN THE VALLEYS FOR FRIDAY MORNING. DRIER OVER THE
WEEKEND AND WARMING ABOVE NORMAL NEXT WEEK.
DISCUSSION
TONIGHT THROUGH SATURDAY: A MODERATELY STRONG ATMOSPHERIC RIVER
WILL BE SITUATED ACROSS THE REGION THROUGH FRIDAY. THE
PROGNOSES IS FOR THE MOISTURE PLUME WITH P-WATS UP TO 0.8-0.9
INTO THE COASTAL AREAS TO REMAIN NEARLY STATIONARY ACROSS
SOUTHERN WASHINGTON INTO THE SOUTHERN IDAHO PANHANDLE. THE PLUME
DOES SHIFT NORTH SLIGHT THROUGH THE NIGHT, BUT NOT BY MUCH.
THERE IS HIGH CONFIDENCE FOR HEAVY PRECIPITATION IN THE
NEIGHBORHOOD OF 2 INCHES TO FALL FROM THE NORTHEAST BLUE
MOUNTAINS TO THE SOUTHERN AND CENTRAL IDAHO PANHANDLE. THERE ARE
TWO PRIMARY QUESTIONS INTRODUCING UNCERTAINTY INTO THE
FORECAST: (1) WHAT WILL SNOW LEVELS BE AT ACROSS THE PALOUSE,
AND (2) HOW MUCH MOISTURE PIVOTS NORTH ACROSS THE SPOKANE/COEUR
D'ALENE AREA OVERNIGHT INTO FRIDAY MORNING? ADDRESSING THE FIRST
QUESTIONS:
THE LATEST FORECAST FROM THE NATIONAL BLEND OF MODELS SHOWS
SNOW LEVELS OVER THE PALOUSE, BUT WITH A TIGHT GRADIENT. THE
NORTHERN PALOUSE REGION AROUND ROSALIA AND TEKOA IS EXPECTED TO
SEE SNOW LEVELS BETWEEN 2,500-3,000 FEET WITH MOSTLY WET SNOW
FALLING, AND THE SOUTHERN PORTION OF THE PALOUSE AROUND COLTON
AND UNIONTOWN RISING TO BETWEEN 4,000-5,000 FEET WHERE
PRECIPITATION IS EXPECTED TO FALL AS RAIN. THEN A LOT OF
UNCERTAINTY IN BETWEEN WITH THE PRECIPITATION TYPE POTENTIAL,
INCLUDING PULLMAN- MOSCOW. A WINTER WEATHER ADVISORY REMAINS IN
EFFECT FOR THE PALOUSE REGION THROUGH FRIDAY MORNING EAST OF
HIGHWAY 195 FOR THE POTENTIAL OF WET SNOW TO CREATE SLIPPERY
CONDITIONS, BUT LATEST TRENDS INDICATE THAT WE MAY SEE MORE RAIN
THAN SNOW. AS SUCH, WE ARE ALSO ISSUING A FLOOD WATCH THAT WILL
COVER WHITMAN, LATAH, GARFIELD, ASOTIN, NEZ PERCE, AND LEWIS
COUNTIES. THERE IS A CONCERN FOR SMALL STREAM FLOODING ACROSS
THIS AREA ALONG WITH A RISK FOR ROCK SLIDES.
ADDRESSING THE SECOND QUESTION OF MOISTURE PUSHING NORTH
OVERNIGHT AND WHAT THAT MEANS FOR WINTER WEATHER ACROSS THE
SPOKANE AREA, COEUR D'ALENE AREA, SILVER VALLEY AND MOUNTAIN
VALLEYS NORTH OF THESE LOCATIONS. DEW POINT TEMPERATURES
INDICATE A MUCH DRIER AIR MASS FOR THESE AREAS, AND CONFIDENCE
IS INCREASING THAT PRECIPITATION TYPE WOULD FALL AS SNOW. IT
WILL JUST BE A MATTER OF HOW MOISTURE WILL BE AVAILABLE FOR
ACCUMULATING SNOW, AS WELL AS, HOW EFFICIENTLY IT WILL
ACCUMULATE ON ROADS. SLIGHTLY MORE NORTHWARD SHIFT OF THE AR
AND THEN WE'RE LOOKING AT HEAVY WET SNOW FOR FRIDAY MORNING THAT
MAY IMPACT THE COMMUTE FOR THE SPOKANE AND COEUR D'ALENE AREAS.
CONFIDENCE FOR IMPACTS DUE TO SNOW IN THE LOWLANDS IS LOW AND
WILL ELECT TO FOREGO ISSUING A WINTER WEATHER ADVISORY RIGHT
NOW, BUT IT WILL BE A SITUATION TO MONITOR FOR THIS EVENING.
THIS THEN BRINGS US TO THE MOUNTAIN SNOW POTENTIAL. HEAVY
MOUNTAIN SNOW WILL CONTINUE ACROSS THE CASCADES AND IN THE IDAHO
PANHANDLE. AN ADDITIONAL 1 TO 2 FEET OF SNOW IS EXPECTED OVER
STEVENS PASS THROUGH FRIDAY BEFORE TAPERING OFF AS A COLD FRONT
SHUNTS THE MOISTURE SOUTHEAST. LOOKOUT PASS IS EXPECTED TO
RECEIVE AROUND AN ADDITIONAL 2 FEET OF SNOW THROUGH SATURDAY
WITH THE HEAVIEST SNOWFALL EXPECTED TONIGHT THROUGH FRIDAY. SNOW
WILL CONTINUE THROUGH FRIDAY NIGHT INTO SATURDAY, BUT WE WILL
ALSO SEE SNOWFALL RATES BECOME LESS. THE COLD FRONT WILL SWEEP
ACROSS THE REST OF EASTERN WASHINGTON AND THE IDAHO PANHANDLE
FRIDAY NIGHT. WESTERLY WINDS WILL INCREASE FOR SATURDAY WITH
GUSTS GENERALLY UP TO AROUND 30-40 MPH ACROSS THE EXPOSED AREAS
OF THE COLUMBIA BASIN. THESE WINDS WILL BE MUCH LESS THAN WHAT
WE JUST EXPERIENCED.
SATURDAY NIGHT THROUGH THURSDAY: A DRYING TREND COMMENCES OVER
THE WEEKEND. THIS WILL RESULT IN RIVERS AND STREAMS TO SUBSIDE.
TEMPERATURES WILL REMAIN BELOW NORMAL. THIS WILL QUICKLY CHANGE
NEXT WEEK WITH A WARM FRONT PUSHING ACROSS SUNDAY INTO SUNDAY
NIGHT. NOT MUCH MOISTURE WITH THIS FRONT. IT WILL BRING LIGHT
SNOW TO THE MOUNTAINS, BUT MORE NOTABLY WILL BE THE INCREASE IN
TEMPERATURES FOR NEXT WEEK AS IT WILL USHER IN MUCH WARM AIR.
TEMPERATURES CLIMB INTO THE UPPER 60S TO NEAR 70 IN THE COLUMBIA
BASIN BY TUESDAY INTO WEDNESDAY. THE MAIN CONCERN WITH THE
WARMER TEMPERATURES IS TO MONITOR RIVER LEVELS FOR RISES WITH
SNOW MELTING AT LOW TO MID ELEVATIONS. /SVH
AVIATION
00Z TAFS: A MOISTURE LADEN FRONTAL BOUNDARY WITH SUBTROPICAL
MOISTURE HAS STALLED ACROSS SOUTHERN WASHINGTON INTO THE
SOUTHERN AND CENTRAL IDAHO PANHANDLE THIS EVENING. PERSISTENT
RAIN WILL FALL AT KPUW AND KLWS. CEILINGS WILL ALSO LOWER AT
BOTH AIRPORT TERMINALS WITH MVFR CONDITIONS BY THIS EVENING IFR
TO LOW IFR OVERNIGHT. PRECIPTIATION TYPE WILL BE TRICKY AT KPUW
WITH INCR PRECIP INTENSITY LOWERING SNOW LEVELS BUT TRENDS ARE
TOWARD LESS SNOW AND MORE RAIN AT PUW. THERE IS MARGINAL WIND
SHEAR AT PUW THIS EVENING WITH WINDS 1000-2000 FT AGL AROUND
35KTS. THE MARGINAL WIND SHEAR WILL DECREASE 6-7Z. THE BAND OF
PRECIPITATION WILL SLOWLY MEANDER FURTHER NORTH OVERNIGHT WITH
WET SNOW OR A RAIN/SNOW MIX ALSO EXPECTED AT KGEG/KSFF/KCOE AND
IFR CONDITIONS DEVELOPING. ANY SNOW ACCUMULATION WILL BE WET AND
SLUSHY INTO FRIDAY MORNING. GEG/COE HAS A 20% FOR 2 INCHES OR
MORE ACCUM WITH PUW CHANCES AT 10%.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
FOR IFR CONDITIONS TO DEVELOP WITH PRECIPITATION TONIGHT AFTER
04Z AT KEAT/KGEG/KSFF/KCOE/KPUW AIRPORT TERMINALS; HOWEVER,
CONFIDENCE REMAINS LOW FOR PRECIPITATION TYPE. THERMAL PROFILES
ALOFT WILL SUPPORT SNOW, BUT TEMPERATURES NEAR THE SURFACE MAY
RESULT IN AT LEAST SOME MELTING. CONFIDENCE IS LOWEST AROUND
EAT/MWH GIVEN PERSISTENT WESTERLY FLOW IN THE MIDLEVELS AND
TENDENCY FOR THIS FLOW PATTERN TO WORK AGAINST LOW-LEVEL
MOISTENING AND MVFR/IFR CONDITIONS WITH HREF PROBS FROM 30-50%.
/SB
-----------------------
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 45 33 42 32 44 24 / 30 80 80 70 40 0
COEUR D'ALENE 45 32 41 31 43 21 / 50 90 90 80 70 10
PULLMAN 45 33 37 33 41 25 / 90 100 100 100 80 20
LEWISTON 52 38 47 40 48 30 / 90 100 100 100 80 10
COLVILLE 48 29 45 26 45 22 / 30 50 50 40 30 0
SANDPOINT 43 30 40 30 40 21 / 60 80 80 70 80 20
KELLOGG 41 32 38 33 38 19 / 80 100 100 90 90 30
MOSES LAKE 51 35 49 31 49 28 / 20 60 70 50 10 0
WENATCHEE 46 34 46 30 43 28 / 50 80 80 40 10 0
OMAK 50 30 47 28 47 27 / 20 50 40 30 10 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...FLOOD WATCH FROM 11 PM PDT THIS EVENING THROUGH SATURDAY
AFTERNOON FOR LOWER GARFIELD AND ASOTIN COUNTIES-
NORTHEAST BLUE MOUNTAINS-WASHINGTON PALOUSE.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 AM PDT
FRIDAY FOR WASHINGTON PALOUSE.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT FRIDAY FOR CENTRAL
CHELAN COUNTY.
WINTER STORM WARNING UNTIL 5 AM PDT SATURDAY FOR WESTERN
CHELAN COUNTY.
ID...FLOOD WATCH FROM 11 PM PDT THIS EVENING THROUGH SATURDAY
AFTERNOON FOR CENTRAL PANHANDLE MOUNTAINS-IDAHO PALOUSE-
LEWIS AND SOUTHERN NEZ PERCE COUNTIES-LEWISTON AREA.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 AM PDT
FRIDAY FOR IDAHO PALOUSE.
WINTER STORM WARNING UNTIL 11 AM PDT SATURDAY FOR CENTRAL
PANHANDLE MOUNTAINS.
WINTER WEATHER ADVISORY UNTIL 5 AM PDT FRIDAY FOR LEWIS AND
SOUTHERN NEZ PERCE COUNTIES.
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