405  
FXUS66 KOTX 291117  
AFDOTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SPOKANE WA  
317 AM PST THU FEB 29 2024  
   
SYNOPSIS
 
 
MOUNTAIN SNOW, MODERATE AT TIMES, WILL CONTINUE INTO FRIDAY.  
WINDS WILL BE GUSTY TODAY AND STRENGTHEN OVERNIGHT INTO THURSDAY  
MORNING WITH PASSAGE OF A COLD FRONT. AN UNSETTLED WEATHER PATTERN  
WILL REMAIN IN PLACE THROUGH NEXT WEEK WITH SEVERAL OPPORTUNITIES  
FOR RAIN AND SNOW.  
 

 
   
DISCUSSION
 
 
TODAY THROUGH FRIDAY NIGHT: THE PATTERN WILL REMAIN ACTIVE WITH  
MOUNTAIN SNOW AND AREAS OF LOWLAND RAIN TRANSITIONING TO RAIN AND  
SNOW LATER. THERE WILL ALSO BREEZY TO WINDY CONDITIONS, ESPECIALLY  
TODAY. A ROBUST FRONTAL SYSTEM IS CURRENTLY PUSHING INTO THE  
PACIFIC NORTHWEST, WITH A 988MB LOW OVER SOUTHWEST CANADA AND IT  
TRAILING COLD FRONT PUSHING THROUGH THE CASCADES. THIS BOUNDARY  
MOVES TOWARD EASTERN WA LATER THIS MORNING TO EARLY AFTERNOON AND  
ON TOWARD THE ID/MT BORDER TOWARD MIDDLE TO LATE AFTERNOON BEFORE  
A COLDER UPPER TROUGH ENVELOPS THE AREA TONIGHT INTO FRIDAY.  
 
* WIND HIGHLIGHTS: CURRENTLY WIND ADVISORIES AND A MORE LOCALIZED  
HIGH WIND WARNING ARE IN PLACE. THE WIND ADVISORIES CONTINUE  
AROUND THE OKANOGAN VALLEY THROUGH WATERVILLE PLATEAU, EAST  
ACROSS THE COLUMBIA BASIN TO NE WA MOUNTAIN AND SPOKANE AREA.  
WINDS THIS AREA AT THIS HOUR ARE GUSTING NEAR 25-30 MPH, WITH  
SOME GUSTS NEAR 40-45 MPH AROUND THE OKANOGAN VALLEY TO  
WATERVILLE PLATEAU. ENSEMBLE GUIDANCE SHOWS THE HIGHEST  
POTENTIAL FOR WINDS GUSTING OVER 40 MPH THIS MORNING, BUT MODELS  
STILL SHOW THE POTENTIAL FOR WINDS GUSTING TO NEAR 30 MPH THIS  
AFTERNOON AND TONIGHT. MEANWHILE THE HIGH WIND WARNING IS FOUND  
AROUND THE CAMAS PRAIRIE, WITH THE POTENTIAL FOR WIND GUSTS OVER  
50 MPH THROUGH THE EARLY AFTERNOON BEFORE THOSE GRADUALLY  
SUBSIDE.  
 
* WINTER HIGHLIGHTS: WINTER STORM WARNINGS REMAIN IN PLACE AROUND  
THE CASCADE CREST, NEAR STEVENS PASS AND CURRENTLY WEB CAMERAS  
SHOW SOME RATHER SNOW COVERED ROADS AT THIS EARLY HOUR. HOWEVER  
BY COLES CORNER THE WEB CAMERA SUGGEST THE ROADS ARE JUST WET.  
IT IS CURRENTLY IN EFFECT THROUGH THIS AFTERNOON, BUT IT WILL BE  
MONITORED SHOULD ANY ADJUSTED MAY BE NEEDED. ADDITIONAL SNOW  
AMOUNTS BETWEEN 3 TO 6 INCHES ARE POSSIBLE IN THE NEXT 24  
HOURS. FARTHER EAST WINTER STORM WARNINGS REMAIN IN PLACE AROUND  
THE NORTH AND CENTRAL ID PANHANDLE MOUNTAINS, ABOVE 4000 FEET  
WHERE AROUND 3 TO 7 INCHES AND LOCALLY OVER A FOOT IS POSSIBLE,  
AND IN THE BLUE MOUNTAINS WHERE UP TO 5 INCHES IS POSSIBLE.  
THESE ARE ALSO IN PLACE THROUGH THIS AFTERNOON AND WILL BE  
MONITORED FOR ANY UPDATES AS WE HEAD THROUGH THE DAY.  
 
THIS MORNING SNOW LEVELS WILL BE AROUND 4-5KFT AHEAD OF THE COLD  
FRONT, BUT THEY WILL BE FALLING FROM THE WEST THROUGH THE DAY.  
THIS MEANS MAINLY SNOW NEAR THE CASCADES AND EASTERN MOUNTAINS AND  
RAIN OVER THE EASTERN LOWLANDS THIS MORNING, BUT THE POTENTIAL FOR  
A MIX STARTS TO COME IN TO THE LOWLANDS AS EARLY AS THIS AFTERNOON  
BETWEEN 1 TO 4 PM. HOWEVER THE BETTER CHANCES COME AFTER 4 PM.  
MORE SPECIFICALLY, MIDDAY SNOW LEVELS ARE FORECAST TO BE NEAR  
1-2KFT OVER THE CASCADES AND CENTRAL WA AND 3-4.7KFT FROM THE EAST  
THIRD OF WA TO THE MT BORDER, THEN BETWEEN 0.5-2.5KFT BY SUNSET  
AND THEN BY FRIDAY MORNING TOWARD MOST VALLEY FLOORS. THEY DO  
RECOVER TO ABOUT 1-2.5KFT FOR FRIDAY AFTERNOON, WITH THE HIGHER  
END OF THAT RANGE TOWARD THE LOWER ID PANHANDLE, THEN FALL AGAIN  
TOWARD THE MOST VALLEY FLOORS LATER FRIDAY NIGHT INTO EARLY  
SATURDAY.  
 
TEMPERATURES OVERALL MAY BE A BIT TRICKY TODAY. THEY MAY NOT RISE  
MUCH IN THE EAST WITH BEST CHANCE FOR PRECIPITATION DAMPENING ANY  
POTENTIAL RISES DURING THE AFTERNOON, BUT SOME DOWNSLOPING IN THE  
LEE OF THE CASCADES COULD STILL RESULT IN SOME AREAS WARMING  
TOWARD 50 THERE. FRIDAY'S HIGH TEMPERATURES WILL LARGELY BE IN  
THE UPPER 30S AND 40S WITH OVERNIGHT LOWS IN THE MID-20S TO LOW  
30S.  
 
SO HOW WILL THE PRECIPITATION EVOLVE WITH THIS SYSTEM? ALONG AND  
AHEAD OF THE COLD FRONT IS SOME MOISTURE, WITH PWATS AROUND 0.50”  
OR ABOUT 150-200% OR NORMAL. THIS SET-UP WILL CONTINUE TO PRODUCE  
THE HIGHEST PRECIPITATION POTENTIAL OVER THE CASCADE CREST AND THE  
EASTERN THIRD OF WA AND ID. THE HEAVIER PRECIPITATION RATES NEAR  
THE CASCADE CREST (LARGELY AS SNOW) WILL DECLINE EARLY THIS  
MORNING WITH THE COLD FRONT NOW SHIFTING EAST OF THERE. FARTHER  
EAST, THE OVERNIGHT PRECIPITATION MAY BRIEFLY WANE OVER THE  
SPOKANE/COEUR D'ALENE AREA AND PALOUSE SOUTHWARD VERY EARLY.  
HOWEVER AS THE COLD FRONT STARTS TO MOVE IN FROM THE WEST THE  
PRECIPITATION BAND IS EXPECTED TO BE REVITALIZED COMING JUST EAST  
OF THE CASCADES THROUGH NORTH-CENTRAL WA EARLY THIS MORNING,  
COMING INTO THE AREAS MENTIONED ABOVE BETWEEN 8 AM TO 12 PM.  
 
MEANWHILE THE PRECIPITATION WILL REMAIN STEADIER OVER THE  
NORTHEAST WA AND ID PANHANDLE MOUNTAIN ZONES, BUT THIS IS ALSO  
EXPECTED TO INCREASE IN INTENSITY WITH THE COLD FRONT. IN FACT,  
THIS AFTERNOON SNOWFALL RATES OVER IDAHO PANHANDLE MOUNTAINS RATES  
COULD LOCALLY REACH 0.5-1"/HOUR. HREF PROBABILITIES SHOW THAT  
POTENTIAL OF >=0.5"/HR SNOW RATES BETWEEN 40-80% AND >=1"/HR  
SNOWFALL RATES BETWEEN 40-60%, INCLUDING PLACES LIKE LOOKOUT PASS.  
THE HIGHEST RATES PER THIS GUIDANCE ARE PLACED BETWEEN ABOUT 1 TO  
4 PM, BEFORE QUICKLY DECLINING AFTER 4-5 PM.  
 
BEHIND THE COLD FRONT FOR LATER THIS AFTERNOON INTO TONIGHT THE  
SET-UP IS A BIT DIFFERENT. THE ATMOSPHERE DRIES OUT, WITH PWATS  
DROPPING TO AROUND 0.15 TO 0.20" OR 50-80%. HOWEVER 700-500MB  
LAPSES RATES STEEPEN TO AROUND 8-9 C/KM AND THERE ARE SOME  
EMBEDDED SHORTWAVES. OVERALL PRECIPITATION CHANCES WILL CONTINUE  
BEHIND THE COLD FRONT BUT WILL BE MORE SHOWERY IN NATURE, WITH AT  
LEAST ONE FOCAL POINT ACROSS THE CASCADES TO NORTH-CENTRAL WA WITH  
ONE SHORTWAVE SLIPPING BY. THIS COULD MEAN AN POTENTIAL UPTICK IN  
THOSE SNOWFALL RATES NEAR THE CASCADE CREST, INCLUDING NEAR THE  
PASSES BUT WHAT I AM SEEING FROM THE VARIOUS ENSEMBLES SUGGESTS IT  
WOULD NOT HOLD OVER ANY SPOT FOR TOO LONG. OTHER SPOTTY SHOWERS  
WILL BE POSSIBLE ON THE BACKSIDE OF THE FRONT OVER THE EASTERN OF  
WA GOING INTO THIS EVENING INTO TONIGHT TOO, THOUGH THE BETTER  
RISK WILL LINGER AROUND THE MOUNTAINS, WITH THE MOST OF THAT  
LOWLAND PRECIPITATION POTENTIAL CHANGING TO A RAIN/SNOW MIX OR  
EVEN ALL SNOW BY FRIDAY MORNING. I CANNOT RULE OUT AN EMBEDDED  
RUMBLE OF THUNDER WITH SOME OF THE SHOWERS AROUND THE CASCADES  
AND NORTHERN MOUNTAINS THIS AFTERNOON/EVENING IN THE INSTABILITY  
BEHIND THE COLD FRONT, BUT PROBABILITIES ARE ONLY AROUND 10% AT  
THIS TIME AND NOT ENOUGH TO PUT IN THE OFFICIAL FORECAST.  
 
AS WE HEAD INTO FRIDAY AND FRIDAY NIGHT THE AREA WILL REMAIN IN  
THE ACTIVE SOUTHWEST FLOW, WITH IMPULSES RIDING AROUND THE  
OFFSHORE TROUGH. THIS WILL KEEP SHOWER CHANCES ALIVE ACROSS THE  
REGION, WITH THE HIGHER POTENTIAL FOR FRIDAY AFTERNOON INTO FRIDAY  
NIGHT AS A COUPLE MORE ORGANIZED SHORTWAVE IMPULSES RIDE IN. THE  
FRIDAY NIGHT WAVE COMES WITH A SLIGHT INCREASE IN MOISTURE TOO.  
THE SNOW COULD ACCUMULATE A COUPLE INCHES IN THE MOUNTAINS AND  
LATE FRIDAY NIGHT INTO SATURDAY MORNING THERE COULD BE SOME LIGHT  
ACCUMULATION IN THE LOWLANDS, INCLUDING FROM THE LEE OF THE  
CASCADES THROUGH THE WATERVILLE PLATEAU TO THE NORTHERN COLUMBIA  
BASIN AND LOWER SELKIRKS EAST TOWARD THE PALOUSE AND CENTRAL  
PANHANDLE, WITH MAYBE UP TO AN HALF INCH OR SO BY EARLY SATURDAY.  
HOWEVER THE POTENTIAL FOR ADDITIONAL ACCUMULATION CONTINUES INTO  
THE DAY SATURDAY. /SOLVEIG  
 
SATURDAY THROUGH THURSDAY: THE BROAD, DEEP UPPER LEVEL TROUGH  
WILL CONTINUE TO AIM A PLUME OF MOISTURE AT THE SIERRA MOUNTAINS  
IN CALIFORNIA/NEVADA AS WE BEGIN THE WEEKEND, WHILE THE INLAND  
NORTHWEST REMAINS UNDER THE UNSETTLED, MOIST FLOW ALOFT RESULTING  
IN SEVERAL ROUNDS OF PRECIPITATION. SEVERAL SHORTWAVE FEATURES  
WILL MOVE THROUGH THE INLAND NORTHWEST SATURDAY AND SUNDAY AS THE  
PARENT TROUGH PROGRESSES THROUGH THE GREAT BASIN OVER THE WEEKEND  
THROUGH TUESDAY. BY THAT TIME, A MORE ZONAL FLOW/WESTERLY FLOW  
PATTERN WILL SETUP. THE ENSEMBLE GUIDANCE IS IN GREAT AGREEMENT  
LATE THIS WEEKEND INTO EARLY NEXT WEEK WITH REGARD TO THE STRENGTH  
AND LOCATION OF THE TROUGH BRINGING A COOLER AND ACTIVE WEATHER  
PATTERN TO THE NORTHWEST. SNOW LEVELS WILL REMAIN LOW ENOUGH FOR  
SNOW TO VALLEYS/LOW ELEVATION AREAS THROUGH TUESDAY.  
 
THE AVAILABLE MOISTURE WILL BE QUITE MINIMAL THIS WEEKEND INTO  
EARLY NEXT WEEK, WITH PRECIPITABLE WATER VALUES AROUND 40-50% OF  
NORMAL, AND THE TEMPERATURE PROFILE AT 850MB WILL REMAIN -5C TO  
-7C THROUGH EARLY NEXT WEEK. SO, THE PRECIPITATION TYPE SHOULD BE  
COLD ENOUGH FOR SNOW TO THE VALLEY LOCATIONS AND THE SNOW TO  
LIQUID (SLR) RATIO WILL BE HIGHER GIVEN THE COLDER AIRMASS IN  
PLACE. THIS ALL POINTS TO A SMALL AMOUNT OF MOISTURE NEEDED FOR  
MEASUREABLE SNOWFALL. THE TEMPERATURES ALOFT AT 500MB ARE EVEN  
COLDER (-35C) AND THIS WILL ALLOW STEEP LAPSE RATES (8.5-9C/KM)  
AND RESULT IN A MORE CONVECTIVE ENVIRONMENT. SATURDAY AND SUNDAY  
THERE IS A RELATIVELY LIMITED AMOUNT OF INSTABILITY (CAPE) BUT  
NOTHING TO IGNORE GIVEN ALL THE OTHER PARAMETERS IN PLACE. AROUND  
200 J/KG ACROSS EASTERN WASHINGTON AND NORTH IDAHO. THESE  
INGREDIENTS IN PLACE WILL BE CONDUCIVE TO CONVECTIVE SNOW SHOWERS  
RESULTING IN MODERATE TO HIGH IMPACTS FOR TRAVELERS UNDER THESE  
SHOWERS WITH BRIEF ACCUMULATIONS. ROAD TEMPERATURES OVERNIGHT ARE  
FORECAST TO DIP TO NEAR/JUST BELOW FREEZING, WHICH COULD RESULT IN  
SLICK DRIVING CONDITIONS IF SNOW ACCUMULATES IN SPECIFIC AREAS.  
 
* SNOW ACCUMULATIONS: SATURDAY AND SUNDAY ACCUMULATIONS WILL BE  
GREATEST IN THE HIGHER ELEVATIONS AND MOUNTAINS AND WILL LARGELY  
BE DRIVEN BY CONVECTIVE SNOW SHOWERS. CONFIDENCE IS LOW IN THE  
HIGHER AMOUNTS BEING ADVERTISED BY THE SHORT-RANGE ENSEMBLES BUT I  
CAN NOT DISCOUNT THOSE POTENTIALS. SHERMAN PASS HAS A 50% CHANCE  
OF SEEING OVER 4 INCHES AND A 25% CHANCE OF SEEING OVER 6 INCHES,  
ACCORDING TO THE NBM. SANDPOINT IS ANOTHER LOCATION WHICH MAY  
PERFORM WELL WITH SNOW AMOUNTS. A 53% CHANCE OF OVER 4 INCHES, 20%  
CHANCE FOR OVER 6 INCHES. SPOKANE AND COEUR D'ALENE HAVE 1-3  
INCHES IN THE FORECAST AMOUNTS, AND A 35% CHANCE OF MORE THAN 2  
INCHES.  
 
* TEMPERATURES: IT'S EARLY MARCH SO THE TEMPERATURES CAN SEE BIG  
SWINGS FROM DAYTIME TO OVERNIGHT; NORMALS IN THE MID TO UPPER 40S  
DURING THE DAY AND AT OR BELOW FREEZING (32F) OVERNIGHT. GIVEN OUR  
HIGHER SUN ANGLE, ANY SNOW THAT DOES FALL AND ACCUMULATE HAS  
BETTER CHANCES OF NOT LASTING FOR VERY LONG ON GRASSY AND ROAD  
SURFACES. HOWEVER, THAT DOESN'T MEAN THAT ROADS/SURFACES WON'T BE  
SLICK IF WE SEE MOISTURE LINGERING AFTER THE SUN SETS.  
 
BY MID WEEK NEXT WEEK, ENSEMBLES CONTINUE WITH A PROGRESSIVE BUT  
WEAKER TROUGH FEATURE THAT WILL BRING MORE WESTERLY FLOW TO THE  
REGION. SOUNDING LIKE WE'RE ON REPEAT, AN UNSETTLED AND ACTIVE  
PERIOD OF WEATHER WILL CONTINUE BUT THE IMPACTS SHOULD BE LITTLE TO  
MINOR FOR THE REGION. /DEWEY  
 

 
   
AVIATION
 
 
12Z TAFS: PRECIPITATION WILL CONTINUE AROUND THE CASCADES AND  
MOUNTAINS, AS WELL AS THE EASTERN THIRD OF WA INTO ID, INCREASING  
IN INTENSITY AS WE PROGRESS THROUGH THE MORNING INTO EARLY  
AFTERNOON. PRECIPITAITON WILL THEN START TO TURN MORE SHOWERY AND  
DECREASE THROUGH THE EVENING INTO EARLY FRIDAY. THIS WILL MAINLY  
IN THE FORM OF RAIN THROUGH THE DAY, THEN TURN TO A MIX OR ALL  
SNOW POTENTIAL THIS EVENING INTO EARLY FRIDAY. LOOK FOR PRIMARILY  
VFR CIGS, DECREASING TO MVFR WITH STEADIER PRECIPITATION OVER THE  
UPPER COLUMBIA BASIN INTO THE SPOKANE/C'DA AREA AND PULLMAN  
THROUGH AT LEAST THIS EVENING. SOME IMPROVEMENT IS POSSIBLE IN  
THE LATER EVENING, ESPECIALLY SOUTH BUT IT THE MVFR/LCL IFR  
CONDITIONS MAY HOLD ON NEAR GEG/SFF/COE AND IN THE NORTHEAST  
VALLEYS. EXPECT BREEZY TO WINDY CONDITIONS. THERE IS A 50-70%  
CHANCE FOR GUSTS 40-50 MPH AT TIMES EARLY THIS MORNING. ANOTHER  
AREA OF CONCERN FOR DAMAGING WIND GUSTS ON THE ORDER OF 60 MPH  
WILL BE POSSIBLE IN THE LOWER IDAHO PANHANDLE AROUND WINCHESTER  
AND GRANGEVILLE THIS MORNING AND EARLY AFTERNOON. OTHERWISE, BE  
PREPARED FOR REGIONWIDE MOUNTAIN OBSCURATIONS.  
 
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:  
MODERATE TO HIGH CONFIDENCE FOR STEADY RAINFALL PROMOTING MVFR  
CONDITIONS AND STEADY WINDS OF 15-25 MPH. LOWER CONFIDENCE IS  
OVERNIGHT MVFR/IFR CONDITIONS NEAR GEG/SFF/COE. LOWER CONFIDENCE  
IN SUSTAINED WIND SPEEDS REACHING 30 MPH AND HIGHER. HIGH  
CONFIDENCE FOR WIND GUSTS TO 35 MPH. LOWER CONFIDENCE FOR  
FREQUENCY AND EXACT TIMING OF WIND GUSTS IN EXCESS OF 40 MPH.  
 
------------------  
 
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 44 29 41 29 38 24 / 80 30 50 60 70 30  
COEUR D'ALENE 43 27 38 27 36 21 / 90 50 60 50 80 30  
PULLMAN 46 28 41 30 39 24 / 90 30 50 60 80 30  
LEWISTON 53 32 48 33 44 28 / 80 30 40 50 60 20  
COLVILLE 43 27 39 26 38 19 / 80 50 70 50 90 40  
SANDPOINT 41 29 36 27 34 21 / 90 70 80 50 90 60  
KELLOGG 45 28 38 28 36 21 / 100 70 70 60 90 50  
MOSES LAKE 49 31 46 31 44 26 / 30 20 20 40 30 10  
WENATCHEE 50 29 42 29 41 25 / 20 30 30 40 30 10  
OMAK 52 30 44 30 41 24 / 40 20 40 60 70 20  
 

 
   
OTX WATCHES/WARNINGS/ADVISORIES
 
 
ID...WINTER STORM WARNING UNTIL 4 PM PST THIS AFTERNOON FOR CENTRAL  
PANHANDLE MOUNTAINS-NORTHERN PANHANDLE.  
 
HIGH WIND WARNING FROM 7 AM THIS MORNING TO 2 PM PST THIS  
AFTERNOON FOR LEWIS AND SOUTHERN NEZ PERCE COUNTIES.  
 
WA...WINTER STORM WARNING UNTIL 4 PM PST THIS AFTERNOON FOR NORTHEAST  
BLUE MOUNTAINS-WESTERN CHELAN COUNTY.  
 
WIND ADVISORY UNTIL 10 AM PST THIS MORNING FOR MOSES LAKE AREA-  
NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-OKANOGAN VALLEY-  
SPOKANE AREA-UPPER COLUMBIA BASIN-WATERVILLE PLATEAU.  
 

 
 

 
 
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