824
FXUS66 KOTX 202311
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
311 PM PST THU FEB 20 2025
SYNOPSIS
WARMER TEMPERATURES AND RAIN WILL ARRIVE THIS WEEKEND AS HIGH
TEMPERATURES WARM INTO THE 40S. RUNOFF FROM RAIN AND MELTING SNOW
WILL LEAD TO INCREASED FLOW ON CREEKS AND STREAMS IN SOUTHEAST
WASHINGTON AND THE CENTRAL AND SOUTHERN IDAHO PANHANDLE.
DISCUSSION
TONIGHT: THE WEATHER OVERNIGHT WILL BE RELATIVELY QUIET WITH AN
UPPER LEVEL RIDGE OF HIGH PRESSURE MOVING INTO THE INLAND
NORTHWEST. WITH PERSISTENT LOW LEVEL SOUTHERLY FLOW THROUGH THE
NIGHT AND INTO THE MORNING, THERE IS A HIGH LIKELIHOOD THAT LOW
CLOUDS WILL REMAIN IN PLACE ACROSS THE MOSES LAKE AREA, WATERVILLE
PLATEAU, AND THE VALLEYS OF NORTH CENTRAL AND NORTHEAST
WASHINGTON. THE CLOUD COVER WILL KEEP OVERNIGHT LOWS IN THE UPPER
20S TO LOW 30S OVER MOST OF THE INLAND NORTHWEST. THE PALOUSE AND
PORTIONS OF THE CENTRAL AND SOUTHERN IDAHO PANHANDLE MAY BE THE
EXCEPTION WHERE LOW TO MID 20S WILL BE POSSIBLE DEPENDING ON
CLOUD COVER. THE HIGH RESOLUTION ENSEMBLE FORECAST (HREF)
GENERATES ENOUGH OF AN EASTERLY COMPONENT TO THE SURFACE WIND FOR
MUCH OF WHITMAN, LATAH, AND BENEWAH COUNTIES TO LOSE THE LOW
CLOUDS BY SUNRISE (90 PERCENT PROBABILITY). PLACES THAT CLEAR AT
LEAST A COUPLE HOURS PRIOR TO SUNRISE WILL HAVE THE BEST CHANCES
OF DROPPING BELOW 25 DEGREES.
FRIDAY AND SATURDAY: A WEAK FRONTAL SYSTEM CROSS EASTERN
WASHINGTON AND NORTH IDAHO FRIDAY AFTERNOON INTO FRIDAY EVENING.
THE SURFACE LOW ASSOCIATED WITH THIS FRONT WILL MAKE LANDFALL WELL
NORTH OF OUR REGION (SHORES OF NORTHWEST BC). WITH THE LOW LEVEL
DYNAMICS SO FAR NORTH, PRECIPITATION AMOUNTS WILL BE LIGHT AND WE
WON'T EXPERIENCE A VERY NOTICEABLE WIND SHIFT EITHER. SNOW LEVELS
WILL BE LOW ENOUGH FRIDAY AFTERNOON INTO SATURDAY MORNING FOR SNOW
ACROSS OUR NORTHERN COUNTIES INCLUDING THE METHOW VALLEY,
REPUBLIC, COLVILLE, DEER PARK, METALINE, AND BONNERS FERRY TO
EXPERIENCE PERIODS OF LIGHT SNOW. PORTIONS OF SPOKANE MAY ALSO
EXPERIENCE A RAIN/SNOW MIX SATURDAY AFTERNOON AND EVENING, BUT THE
PROBABILITY OF RECEIVING AN INCH OF ACCUMULATION IS LESS THAN 10
PERCENT FOR ANY OF THE AFOREMENTIONED AREAS. OVERNIGHT LOWS FRIDAY
ARE EXPECTED TO REMAIN ABOVE FREEZING ACROSS THE L-C VALLEY,
PALOUSE, SPOKANE AREA, AND VALLEYS OF NORTHEAST WASHINGTON AND
NORTH IDAHO. FRIDAY NIGHT WILL BE THE FIRST OF SEVERAL NIGHTS
ABOVE FREEZING AS SNOW LEVELS CLIMB INTO THE 5000-7000FT RANGE BY
SATURDAY AFTERNOON. /GKOCH
SATURDAY NIGHT TO WEDNESDAY: THE INLAND NW IS TRANSITIONING INTO A
PERIOD OF WARMER AND WETTER WEATHER AS A SERIES OF SYSTEMS MOVE
THROUGH THE REGION. A WARM FRONT WILL ARRIVE LATE SATURDAY, BRINGING
WIDESPREAD PRECIPITATION, PARTICULARLY TO THE ENTIRE REGION. SNOW
LEVELS WILL RISE THROUGHOUT THE DAY, WITH PRECIPITATION MAINLY
FALLING AS HIGH MOUNTAIN SNOW AND LOWLAND RAIN, THOUGH A WINTRY MIX
MAY OCCUR IN THE METHOW VALLEY DUE TO COLDER TEMPERATURES WITHIN THE
VALLEY. RAIN TOTALS IN FAR EASTERN WA AND NORTH ID WILL SEE 0.6 AND
1.5 INCHES, AND 0.15 TO 0.5 INCHES FOR CENTRAL WA.
A SECOND WAVE OF PRECIPITATION WILL MOVE THROUGH SUNDAY AS A
SHORTWAVE BRINGS ADDITIONAL RAIN. THE COMBINATION OF RAIN, WARMER
TEMPERATURES AND BREEZY WINDS WILL LEAD TO RAPID SNOWMELT ACROSS
ACROSS LOWLAND AREAS, WHERE RECENT SNOW HAS FALLEN. THIS WILL CAUSE
RISES IN CREEKS AND STREAMS, URBAN PONDING AND FIELD FLOODING. THE
FORECAST FOR PARADISE CREEK CONTINUES TO TREND TOWARDS MINOR FLOOD
STAGE BY SATURDAY AFTERNOON. LOOKING AHEAD, A THIRD SYSTEM WILL
BRING MORE PRECIPITATION AND POSSIBLE STRONGER WINDS MONDAY THROUGH
TUESDAY. WHILE THE TIMING AND STRENGTH REMAIN UNCERTAIN, TRENDS SHOW
WIND GUSTS AROUND SPOKANE/CDA DOWN TO THE PALOUSE AND INTO THE
COLUMBIA BASIN REACHING 40+ MPH GUSTS. STARTING WEDNESDAY, HIGH-
PRESSURE RIDGE SETTLES OVER THE WESTERN US. /KK
AVIATION
18Z TAFS: THERE ARE SEVERAL LOW CLOUD BANKS ACROSS CENTRAL/EASTERN
WASHINGTON AND NORTH IDAHO FOLLOWING THE PASSAGE OF YESTERDAY'S
ROUND OF PRECIPITATION. WITH WEAK SOUTH WINDS JUST ABOVE THE
SURFACE AND WIDESPREAD SNOW COVER, ANY IMPROVEMENT IN CEILINGS
AND VISIBILITY AT SPOKANE INTERNATIONAL WILL BE GRADUAL THROUGH
THE DAY AND NIGHT DUE TO LIGHT UPSLOPE FLOW. WITH SUNSHINE AT TRI
CITIES AND WALLA WALLA, SURFACE WARMING IN THE DEEP COLUMBIA
BASIN SHOULD HELP ERODE AND LIFT THE LOW CLOUDS AROUND MOSES LAKE
AND EPHRATA, BUT THE HREF SUGGESTS THAT AFTERNOON IMPROVEMENTS AT
MWH AND EPH WILL BE LOST BY FRIDAY MORNING WITH THE EXPANSION OF
CLOUDS THROUGH THE NIGHT.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: OVERALL,
CONFIDENCE IN THE CEILINGS IS MODERATE TO LOW. IT IS NOT UNUSUAL
FOR LOW CLOUD LAYERS TO VARY ACROSS THE INLAND NORTHWEST FOLLOWING
A PRECIPITATION EVENT. AFTER ABOUT 24 TO 36 HOURS, CLOUD LAYERS
OFTEN CONSOLIDATE AS THE INVERSION LAYER STABILIZES. THE
WENATCHEE AND LEWISTON TAFS WILL LIKELY BE ESPECIALLY PROBLEMATIC
THIS AFTERNOON AND EVENING WITH FOG AND LOW CLOUDS BEING
CHANNELED THROUGH THE COLUMBIA AND SNAKE/CLEARWATER VALLEYS. WILL
THERE BE ENOUGH WARMING OF THE VALLEY WALLS TO DISPERSE THE
FOG/CLOUDS OR WILL THE LOW CLOUDS BE TRAPPED LATE INTO THE DAY?
TOUGH CALL. /GKOCH
-----------------------
CONFIDENCE DESCRIPTORS:
LOW - LESS THAN A 30 PERCENT CHANCE
MODERATE - 30 TO 70 PERCENT CHANCE
HIGH - GREATER THAN A 70 PERCENT CHANCE
PRELIMINARY POINT TEMPS/POPS
SPOKANE 27 40 36 43 41 47 / 0 10 70 50 100 80
COEUR D'ALENE 27 42 34 44 39 47 / 0 10 70 70 100 90
PULLMAN 26 37 34 42 39 45 / 0 10 50 40 100 90
LEWISTON 27 42 37 49 43 50 / 0 0 30 20 90 90
COLVILLE 27 39 33 43 38 45 / 10 50 70 60 100 70
SANDPOINT 29 40 35 41 39 44 / 10 30 90 90 100 90
KELLOGG 25 42 36 43 40 44 / 0 10 70 80 100 100
MOSES LAKE 29 41 31 49 40 52 / 0 10 30 20 70 70
WENATCHEE 30 38 33 43 38 48 / 0 30 30 40 70 70
OMAK 29 38 33 42 36 46 / 0 40 50 40 90 60
OTX WATCHES/WARNINGS/ADVISORIES
ID...NONE.
WA...NONE.
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