236
FXUS66 KOTX 010502
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1002 PM PDT MON MAR 31 2025
SYNOPSIS
SHOWERS WILL CONTINUE ACROSS THE REGION FOR MONDAY. ISOLATED
THUNDERSTORMS ARE POSSIBLE MONDAY AFTERNOON. COOL AND UNSETTLED
WEATHER PATTERN WILL PERSIST THROUGH MUCH OF THE WEEK WITH A
WARMING AND DRYING TREND BY THE WEEKEND.
DISCUSSION
TONIGHT THROUGH WEDNESDAY NIGHT: UNSETTLED WEATHER WILL CONTINUE.
THIS AFTERNOON REGIONAL RADAR SHOWS SHOWERS SCATTERED THROUGHOUT
THE REGION, BUT THERE ARE SOME FOCUSING MECHANISMS FOR THESE
SHOWERS. IN THE LARGE SCALE LOW PRESSURE IS CENTERED OFF THE COAST
AND THAT BROAD FEATURE WILL SHIFT INLAND OVERNIGHT INTO TUESDAY
MORNING. A DEFORMATION AXIS AROUND ITS EAST TO NORTH SIDE, FROM
IDAHO TO NORTHEAST WA AND BACK SOUTHWEST INTO THE DEEPER BASIN,
WILL GRADUALLY PIVOT EASTWARD THROUGH THAT SAME PERIOD. ANYWHERE
ALONG THAT FEATURE AND UNDER THE TROUGH THERE WILL BE A RISK FOR
SHOWERS AND MAYBE SOME ISOLATED T-STORMS.
SHOWERS HAVE BEEN LOCALLY FOCUSED OVER SOUTHEAST WA AND LOWER ID
WITH AN UPPER IMPULSE SLIDING BY. THESE WILL CONTINUE TO TRACK
EAST-NORTHEAST THROUGH THIS EVENING, WITH OTHER WAVE POTENTIALLY
SLIPPING BY THE BLUES AND CAMAS PRAIRIE AND L-C VALLEY ON ITS
HEELS. ANOTHER FOCAL POINT FOR SHOWERS WILL BE AROUND AROUND THE
NORTHERN COLUMBIA BASIN WEST-SOUTHWEST TOWARD THE WATERVILLE
PLATEAU/WESTERN BASIN. THAT FEATURE IS EXPECTED TO LINGER THERE
THROUGH THE EVENING, GRADUALLY MIGRATING EAST ACROSS THE UPPER
COLUMBIA BASIN AND SPOKANE/C'DA OVERNIGHT INTO TUESDAY MORNING.
AS WE HEAD INTO TUESDAY AFTERNOON, THE UPPER TROUGH AND CONTINUED
INSTABILITY WILL ALLOW FOR THE BUBBLING UP OF SCATTERED SHOWERS
AGAIN IN THE HEATING OF THE DAY. THESE WILL BE KIND OF HIT-AND-
MISS AGAIN TOO, BUT A SECONDARY UPPER WAVE COMING IN FROM THE
NORTHWEST LATER IN THE AFTERNOON INTO TUESDAY NIGHT WILL ALLOW
MORE MORE FOCUSED SHOWER CHANCES. THEY WILL FIRST BE MORE AROUND
THE CASCADES, CENTRAL WA AND THEN MIGRATE TOWARD EASTERN WA AND
NORTH ID IN THE EVENING AND ON THROUGH IDAHO BY LATE EVENING INTO
THE OVERNIGHT.
SOME SHOWERS BETWEEN THIS AFTERNOON INTO TUESDAY COULD BE LOCALLY
HEAVY. SOME HAVE BEEN HEAVY ENOUGH TO CAUSE WET-BULB COOLING
ENOUGH TO MIX SOME SNOW DOWN. SO THAT IS SOMETHING TO WATCH OUT
FOR. ADDITIONALLY ISOLATED EMBEDDED T-STORMS ARE POSSIBLE AND
COULD BRING LOCALLY HEAVY DOWNPOURS, GUSTY WINDS AND SMALL HAIL.
SOME OF THAT MAY COME IN THE FORM OF A RAIN/SNOW MIX IN THE
LOWLANDS OVERNIGHT/EARLY TUESDAY. MEANWHILE IN THE MOUNTAINS,
INCLUDING THE PASSES, SNOW WILL BE MORE LIKELY. ACCUMULATIONS OF
1-3 INCHES WILL BE POSSIBLE, BUT DURING THE DAYTIME HOURS IT WILL
BE HARDER FOR THOSE ACCUMULATIONS TO STICK. SO IMPACTS ARE
EXPECTED TO BE LIMITED.
HEADING INTO WEDNESDAY WE WILL REMAIN UNDER THE INFLUENCE OF AN
UPPER TROUGH, BUT MORESO IN A WEST-NORTHWEST FLOW SECTOR OF THE
TROUGH. SHOWER CHANCES WILL CONTINUE AROUND THE CASCADES AND THE
EASTERN MOUNTAINS ZONES, WITH ADDITIONAL CHANCES DEVELOPING IN THE
AFTERNOON ACROSS THE EAST THIRD OF WA AND LOWER ID TOO. IF ANY OF
THIS FALLS IN THE LOWLANDS THERE WILL BE A POTENTIAL RAIN/SNOW
MIX, GIVEN THE COOLER ATMOSPHERE UNDER THE TROUGH.
TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY BELOW SEASONAL NORMS,
WITH HIGHS IN THE UPPER 40S AND 50S AND LOWS IN THE UPPER 20S AND
30S.
THURSDAY THROUGH MONDAY: THE INLAND NW WILL BE ON THE BACKSIDE OF
A DEPARTING TROUGH THURSDAY INTO FRIDAY BEFORE UPPER-LEVEL
RIDGING SETTLES IN OVER THE WEEKEND. THERE WILL BE ENOUGH
INSTABILITY LINGERING OVER THE REGION THURSDAY AFTERNOON TO KEEP A
MENTION OF SHOWERS YET DRIER AIR CONTINENTAL AIR COMING IN THE
LOWER LEVELS WILL KEEP RAINFALL AMOUNTS VERY LIGHT. BULK OF THE
SHOWERS WILL ALSO FOCUS OVER THE IDAHO PANHANDLE AND EASTERN
REACHES OF WA GIVEN THE NORTHWESTERLY FLOW PATTERN. 70% OF THE
ENSEMBLES ARE DRY BY FRIDAY WITH 30% HOLDING ON TO A GLIMMER OF
HOPE FOR A FEW LAST CONVECTIVE SHOWERS. FORECAST LEANS TOWARD THE
DRIER SCENARIO. CONFIDENCE INCREASES BY THE WEEKEND FOR HIGH
PRESSURE TO BUILD OVER THE NW DELIVERING A DRY, WARMING TREND.
HIGH TEMPERATURES WILL BE REBOUNDING FROM THE 50S AND 60S ON
THURSDAY TO THE 60S AND 70S OVER THE WEEKEND. OUR MAIN UNCERTAINTY
FOR THE FRI-SUN TIME-FRAME REVOLVES AROUND THE AMOUNT OF DRY,
CONTINENTAL AIR THAT BLEEDS IN FROM THE NORTH PRIOR TO THE RIDGE.
THERE IS STILL MODERATE SPREAD BETWEEN THE ENS/GEPS AND GEFS MEANS
TO WHICH RANGE THE DEWPOINTS WILL LOWER TO. IF THEY LOWER INTO
THE LOWER 20S OR UPPER TEENS, THIS WOULD RESULT IN SOME DRY
RELATIVE HUMIDITIES OVER THE WEEKEND AND ELEVATED FIRE WEATHER
CONCERNS IN REGARDS TO BURN PILES SPREADING INTO DRY GRASSES FROM
LAST SUMMER THOUGH WE ARE NOT LOOKING AT MUCH WIND. IF THEY HOLD
IN THE UPPER 20S TO LOWER 30S, HUMIDITY LEVELS WILL BE HIGHER
(CLOSER TO 30%) WHICH LOWERS THE CONCERN FOR FIRE SPREAD. OVERALL,
VERY MINIMAL IMPACTS IN THE GRAND SCHEME BUT SOMETHING TO MONITOR
IF LOOKING TO BURN. THE OTHER IMPACT WOULD BE OVERNIGHT LOWS. A
DRIER SCENARIO WOULD ALLOW STRONG RADIATIONAL COOLING AND LOWS IN
THE 20S TO 30S WHILE A "HIGHER DEWPOINT" SCENARIO WOULD FAVOR LOWS
MORE IN THE 30S. AS SPRING FEVER SETS IN FOR PLANTING...KEEP THIS
IN MIND.
BY MONDAY, THE RIDGE LOOKS TO TAKE A BLOW FROM AN INCOMING TROF.
70% CHANCE MOST OF THE PRECIPITATION WILL BE DEFLECTED WEST OF
THE CASCADES AND INTO BC BUT THIS WILL LIKELY BRING INCREASING
CLOUDS AND INCREASED WINDS. THE AIR MASS WILL REMAIN MILD WITH
MONDAY LOOKING TO BE ONE OF THE WARMEST DAYS OF THE PERIOD,
ESPECIALLY WITH THE INCREASED WINDS AND BETTER MIXING. /SB
AVIATION
06Z TAFS: SHOWERS WILL CONTINUE OVER THE COLUMBIA BASIN,
EXPANDING EASTWARD OVERNIGHT INTO TUESDAY AM, POTENTIALLY REACHING
GEG/SFF TOWARD 12-15Z. THEN THE HEATING OF THE DAY WILL BRING A
THREAT OF ISOLATED TO SCATTERED SHOWERS TUESDAY PM. ANY HEAVIER
SHOWERS COULD RESULT IN PRECIPITATION TURNING TO SNOW OR AT LEAST
A RAIN/SNOW MIX. VFR CEILINGS ARE EXPECTED THROUGH THE FIRST HALF
OF THE NIGHT, THEN HEADING INTO TUESDAY AM (10-14Z) MODELS SHOW
AN EXPANDING MVFR STRATUS DECK OVER EASTERN WA AND NORTH ID, WITH
A SOME RISK FOR IFR CONDITIONS DEVELOPING. GEG/SFF/COE HAVE THE
BEST CHANCES OF MVFR.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: MODERATE
UNCERTAINTY FOR CIGS IN EASTERN WA AND NORTH ID. MODERATE
CONFIDENCE IN MVFR CONDITIONS TOWARD TUESDAY AM NEAR GEG/SFF/COE.
LOW CONFIDENCE IN MVFR CONDITIONS AT OTHER TAF SITES. LOW
CONFIDENCE IN IFR CONDITIONS AT GEG/SFF/COE.
-----------------------
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 35 49 34 51 34 52 / 30 40 20 20 20 40
COEUR D'ALENE 34 47 34 49 32 50 / 60 50 20 20 30 60
PULLMAN 32 47 34 47 32 49 / 20 20 10 20 10 50
LEWISTON 37 54 39 54 37 55 / 20 20 10 20 10 30
COLVILLE 34 50 31 52 32 53 / 40 30 20 40 30 40
SANDPOINT 35 45 34 46 33 49 / 60 50 30 40 50 80
KELLOGG 35 44 37 44 34 45 / 60 60 30 50 20 80
MOSES LAKE 35 57 33 57 33 60 / 30 20 10 10 0 10
WENATCHEE 37 56 36 56 35 56 / 50 10 0 10 0 10
OMAK 37 58 34 57 33 58 / 60 30 20 20 10 10
OTX WATCHES/WARNINGS/ADVISORIES
ID...NONE.
WA...NONE.
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