525
FXUS66 KOTX 210539
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1039 PM PDT TUE MAY 20 2025
KEY MESSAGES
- A 25% CHANCE FOR AFTERNOON THUNDERSTORMS THROUGH TUESDAY
EVENING IN THE NORTHERN MOUNTAINS.
- PATCHY FROST FOR COLDER POCKETS IN NORTHERN MOUNTAIN VALLEYS
TUESDAY NIGHT INTO WEDNESDAY MORNING.
- CHANCE OF RAIN SHOWERS INCREASED FOR THURSDAY
- MILD WITH SHOWERS AND ISOLATED THUNDERSTORMS START TO THE
HOLIDAY WEEKEND FOLLOWED BY WARM AND DRY CONDITIONS INTO
MEMORIAL DAY.
SYNOPSIS
SHOWERS WILL CONTINUE OVER THE NORTHERN MOUNTAINS AND IDAHO
PANHANDLE THROUGH WEDNESDAY, ALONG WITH A CHANCE OF
THUNDERSTORMS THROUGH TUESDAY EVENING. PATCHY FROST IS EXPECTED IN
COLDER POCKETS OF THE NORTHERN MOUNTAIN VALLEYS FOR WEDNESDAY
MORNING. THEN TEMPERATURES SEE A GRADUAL WARMING TREND INTO THE
HOLIDAY WEEKEND. THURSDAY THROUGH SATURDAY REMAINS UNSETTLED
WITH SHOWERS AT TIMES. DRIER AND WARMER SUNDAY INTO MEMORIAL DAY
WITH TEMPERATURES WARMING INTO THE 80S.
DISCUSSION
TODAY THROUGH THURSDAY MORNING: AS THE LOW PRESSURE SYSTEM CURRENTLY
SITTING OVER TOP OF THE FORECAST AREA SLOWLY WEAKENS AND MOVES OUT
OF THE AREA, RAIN SHOWERS WILL CONTINUE. THESE SHOWERS WILL MOSTLY
BE CONFINED TO THE MOUNTAIN AREAS DUE TO OROGRAPHIC LIFT. RAIN
TOTALS WILL OVERALL BE LESS THAN 0.1 INCHES EXCEPT FOR LOCALIZED
AREAS WITHIN THE MOUNTAINS. WINDS THROUGH THE AFTERNOON WILL
CONTINUE TO BE BREEZY ACROSS MOST OF THE AREA, WITH GUSTS 25-30 MPH
ANTICIPATED. LIFT PROVIDED BY THE LOW WILL CONTRIBUTE TO A GENERAL
CHANCE (25 PERCENT) FOR THUNDERSTORMS THROUGHOUT FAR
NORTHEASTERN WASHINGTON AND THE NORTHERN IDAHO PANHANDLE.
STRONGEST THUNDERSTORMS ARE ANTICIPATED THROUGH AROUND 8PM THIS
EVENING. CLEARING TONIGHT WILL ALLOW TEMPERATURES TO BE CHILLY,
WITH SOME FROST CHANCES. IN PARTICULAR, THE NBM SHOWS
PERCENTAGES OF SEEING 36 DEGREES OR BELOW OVER 60 PERCENT FOR
NORTHEASTERN LOCATIONS SUCH AS REPUBLIC AND COLVILLE. AS SUCH, A
FROST ADVISORY HAS BEEN ISSUED FOR THE NORTHERN MOUNTAINS AND
OKANOGAN HIGHLANDS FROM 2-7AM TOMORROW MORNING. TOMORROW, BOTH
HIGH AND LOW TEMPERATURES ARE EXPECTED TO INCREASE TO CLOSER TO
NORMAL, SO FROST SHOULD NO LONGER BE A RISK. /AS
THURSDAY THROUGH TUESDAY: A MID LEVEL SHORT WAVE TRACKS INTO THE
REGION ON THURSDAY BRINGING ANOTHER ROUND OF SHOWERS TO THE
REGION. THE ENSEMBLES ARE CURRENTLY STRUGGLING WITH THE COVERAGE
OF PRECIPITATION, WITH THE GEFS THE WETTEST WITH AMOUNTS OF
0.10-0.20" ACROSS MUCH OF EASTERN WA/N IDAHO, WHILE THE CANADIAN
ENSEMBLE IS THE DRIEST WITH AMOUNTS LESS THAN 0.10" OVER SE
WASHINGTON INTO THE SOUTH ID PANHANDLE. THE EC ENSEMBLE IS A
COMPROMOISE BETWEEN THE WET GEFS AND DRIER CANADIAN. GIVEN THE
HIGH PWAT'S NEAR 125% OF NORMAL, AND THE SHORT WAVE COMING
THROUGH DURING PEAK HEATING, THE FORECAST IS LEANING TOWARDS A
COMPROMISE OF THE GFS/EC ENSEMBLE SOLUTIONS. THUS POP'S WERE
RAISED ABOVE THE NBM. THIS SHORT WAVE MOVES OUT THURSDAY NIGHT
BRINGING ABOUT A WARMING AND DRYING TREND THROUGH THE MEMORIAL
DAY WEEKEND. SOME RESIDUAL SHOWERS ARE EXPECTED FRIDAY AND
SATURDAY IN THE MOUNTAINS BUT WILL BE ISOLATED/SCATTERED IN
NATURE. THE NEXT TROUGH SETS UP OFF THE COAST PLACING THE INLAND
NW IN A MILDER SOUTHERLY FLOW. THIS WILL ALLOW HIGH TEMPERATURES
TO WARM INTO THE 70S AND 80S BY SUNDAY AND MONDAY. THEN THE
OFFSHORE TROUGH BEGINS TO PUSH THE RIDGE EAST LATE MONDAY INTO
TUESDAY. THE DETAILS BECOME MORE UNCERTAIN THIS FAR OUT, WITH
POP'S NUDGING UPWARD AND TEMPERATURES DOWN HEADING INTO TUESDAY.
JW
AVIATION
06Z TAFS: VFR CONDITIONS ARE FORECAST FOR ALL TAF SITES THROUGH
06Z THURSDAY. WINDS WILL ALSO BE ON THE DECREASE TONIGHT AS
PRESSURE GRADIENTS WEAKEN AND THE LOWER ATMOSPHERE STABILIZES.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
IN VFR CONDITIONS THROUGH THE TAF PERIOD.
-----------------------
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 38 63 43 60 43 67 / 10 10 0 50 20 10
COEUR D'ALENE 37 62 41 60 41 68 / 20 10 0 60 20 20
PULLMAN 37 60 43 56 40 65 / 10 0 10 60 20 10
LEWISTON 44 68 50 64 47 73 / 10 0 10 60 20 10
COLVILLE 32 62 36 64 37 67 / 50 50 10 30 10 20
SANDPOINT 39 61 40 61 43 68 / 30 40 0 50 20 20
KELLOGG 39 58 43 57 43 65 / 20 30 10 70 30 20
MOSES LAKE 39 68 47 71 44 75 / 0 0 10 20 0 10
WENATCHEE 42 68 50 71 47 72 / 0 0 0 20 10 10
OMAK 39 68 42 71 43 73 / 10 10 0 10 10 20
OTX WATCHES/WARNINGS/ADVISORIES
WA...FROST ADVISORY FROM 2 AM TO 7 AM PDT WEDNESDAY FOR NORTHEAST
MOUNTAINS-OKANOGAN HIGHLANDS.
ID...NONE.
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