162
FXUS66 KOTX 011721
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
921 AM PST SUN MAR 1 2026
KEY MESSAGES
- DRY AND MILD THROUGH EARLY TUESDAY.
- MOUNTAIN SNOW AND LOWLAND RAIN RETURNS TUESDAY NIGHT AND
CONTINUES THROUGH NEXT WEEKEND.
SYNOPSIS
TEMPERATURES WILL GRADUALLY TREND WARMER THROUGH TUESDAY.
ACTIVE WEATHER RETURNS TUESDAY NIGHT INTO WEDNESDAY, WITH
MOUNTAIN SNOW, LOWLAND RAIN, AND BREEZY WINDS. THIS WILL BRING
PERIODS OF WINTER TRAVEL CONDITIONS OVER THE MOUNTAIN PASSES.
DISCUSSION
TODAY THROUGH EARLY TUESDAY: QUIET WEATHER CONTINUES AS THE
INLAND NORTHWEST REMAINS UNDER A SPLIT-FLOW REGIME AND SUBTLE
UPPER- LEVEL RIDGING. MOISTURE WRAPPING AROUND A CLOSED LOW
OFFSHORE OF OREGON AND NORTHERN CALIFORNIA WILL BRING PASSING
HIGH-LEVEL CLOUDS TO THE INLAND NORTHWEST AS IT PROGRESSES
INLAND THROUGH MONDAY. HOWEVER, THE STRONGEST DYNAMICS WILL
REMAIN SOUTH OF WASHINGTON AND NORTH IDAHO, KEEPING THE REGION
PRECIPITATION- FREE. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT AN
UPPER-LEVEL RIDGE WILL SHIFT INTO THE PACIFIC NORTHWEST LATE
MONDAY AND TUESDAY AS THE LOW DIGS INTO THE GREAT BASIN. A
RELATIVELY DRY AIR MASS WILL SUPPORT LARGE DIURNAL TEMPERATURE
SWINGS WITH COOL OVERNIGHT LOWS AND WARM AFTERNOON HIGHS.
TEMPERATURES ARE EXPECTED TO PEAK TUESDAY, WITH WIDESPREAD HIGHS
IN THE 50S. THE WARMEST SPOTS WILL BE IN THE LOWER ELEVATIONS
ALONG THE SNAKE RIVER AND IN THE L-C VALLEY, WHERE THERE IS HIGH
CONFIDENCE IN AFTERNOON TEMPERATURES REACHING 60 OR GREATER ON
TUESDAY.
TUESDAY EVENING THROUGH FRIDAY: ACTIVE WEATHER RETURNS LATER IN
THE DAY ON TUESDAY AS THE FIRST IN A SERIES OF WEATHER SYSTEMS
MOVES THROUGH THE PACIFIC NORTHWEST. A WEAK FRONT APPROACHES THE
WA COAST ON TUESDAY, FOLLOWED BY A DEEPER, STRONGER UPPER-LEVEL
TROUGH ON WEDNESDAY. MODELS ARE IN GREAT AGREEMENT REGARDING
THE PRESENCE OF THIS TROUGH, ALTHOUGH UNCERTAINTY REMAINS
REGARDING ITS EXACT TIMING AND STRENGTH. A STRONG WESTERLY FLOW
WILL FAVOR OROGRAPHIC PRECIPITATION. THE 72 HOUR 10TH-90TH
PERCENTILE QPF FROM 5 AM TUESDAY TO 5 AM FRIDAY RANGES BETWEEN
0.50 AND 2.50 INCHES IN THE MOUNTAINS. A PRONOUNCED RAIN SHADOW
IS EXPECTED ACROSS THE COLUMBIA BASIN AND THE LEE OF THE
CASCADES, WHERE TOTALS WILL LIKELY REMAIN BELOW 0.10 INCHES. FOR
FAR EASTERN WASHINGTON, TOTALS MAY RANGE BETWEEN A FEW TENTHS
AND 0.50 INCHES.
THERMAL PROFILES INDICATE SNOW LEVELS WILL INITIALLY BE NEAR OR
SLIGHTLY ABOVE PASS LEVEL, MEANING PRECIPITATION WILL LIKELY
BEGIN AS LIGHT RAIN OR A RAIN/SNOW MIX FOR THE MOUNTAIN PASSES
WITH THE WEAK FRONT ON TUESDAY. SNOW LEVELS WILL THEN LOWER
TUESDAY NIGHT IN THE CASCADES AND WEDNESDAY EVENING FOR THE
IDAHO PANHANDLE. THERE IS A WIDE SPREAD IN THE PROBABILISTIC
SNOW TOTALS FOR THE PASSES FROM 5 AM TUESDAY THROUGH 5 AM FRIDAY
AS PRECIPITATION BECOMES MORE CONVECTIVE ON WEDNESDAY. CURRENT
10TH-90TH PERCENTILE RANGES ARE BETWEEN 1 AND 10 INCHES FOR
STEVENS PASS AND 1 TO 5 INCHES FOR LOOKOUT PASS. THIS WILL
RESULT IN A PERIOD OF WINTER TRAVEL CONDITIONS OVER THE PASSES.
INSTABILITY INCREASES WEDNESDAY AFTERNOON AS THE COLD POOL
ALOFT (500 MB TEMPERATURES NEAR -29C) MOVES IN BEHIND THE FRONT
AND STEEPENS LAPSE RATES. THIS ENVIRONMENT WILL FAVOR SPRING-
LIKE GRAUPEL SHOWERS IN THE LOWLANDS AND SNOW SHOWERS IN THE
MOUNTAINS. STRONGER SHOWERS MAY RESULT IN ISOLATED LIGHTNING,
WITH A 10-15% CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.
ADDITIONAL WAVES SLIDE INTO THE PNW ON THE LEADING EDGE OF AN
OFFSHORE RIDGE THURSDAY AND FRIDAY, WITH MOUNTAIN SNOW SHOWERS
RESULTING IN PERIODS OF WINTER DRIVING CONDITIONS OVER THE
PASSES.
SATURDAY AND SUNDAY: MODELS SUGGEST THE PROGRESSIVE WEATHER
PATTERN WILL CONTINUE INTO THE WEEKEND, THOUGH A GREAT DEAL OF
UNCERTAINTY EXISTS REGARDING THE SYNOPTIC SETUP OF THE OFFSHORE
RIDGE, A DIGGING TROUGH IN THE CENTRAL US, AND A COLD FRONT AND
UPPER-LEVEL TROUGH MOVING IN FROM THE NORTHEASTERN PACIFIC
SOMETIME SUNDAY. A STRONG OFFSHORE RIDGE WOULD DEFLECT THE
APPROACHING SYSTEM NORTHWARD AND RESULT IN A MILDER, DRIER
OUTCOME. A WEAKER OFFSHORE RIDGE WOULD ALLOW THE TROUGH TO DIG
FURTHER SOUTH INTO THE REGION, RESULTING IN INCREASED
PRECIPITATION, COOLER TEMPERATURES, AND STRONGER WINDS. /VMT
AVIATION
18Z TAFS: MAINLY MID AND HIGH LEVEL CLOUDS PASSING THROUGH
SOUTHERN WASHINGTON AND THE LOWER IDAHO PANHANDLE, OTHERWISE
CLEAR SKIES. VFR CONDITIONS WILL PREVAIL THROUGH MONDAY MORNING.
WINDS WILL BE LIGHT AND VARIABLE WITH OCCASIONAL SPEEDS NEAR
8KTS AT MOSES LAKE AND COEUR D ALENE.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
FOR VFR CONDITIONS. THERE IS A LOW PROBABILITY FOR A SLIGHT
INCREASE IN NORTHERLY WINDS THROUGH THE OKANOGAN VALLEY
OVERNIGHT INTO MONDAY MORNING WITH OMAK REACHING 10-12KTS
13-17Z.
-----------------------
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 51 30 53 34 52 41 / 0 0 0 0 10 60
COEUR D'ALENE 52 31 52 33 51 40 / 0 0 0 0 10 70
PULLMAN 52 35 51 34 53 41 / 0 0 0 0 10 70
LEWISTON 56 39 57 37 59 45 / 0 10 0 0 0 50
COLVILLE 51 29 53 31 49 38 / 0 0 0 0 10 50
SANDPOINT 48 30 49 32 47 39 / 0 0 0 0 20 80
KELLOGG 51 33 51 34 49 41 / 0 0 0 0 20 80
MOSES LAKE 55 30 56 34 57 40 / 0 0 0 0 0 20
WENATCHEE 52 36 56 37 54 40 / 0 0 0 0 10 40
OMAK 52 33 53 35 50 39 / 0 0 0 0 10 30
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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