512
FXUS66 KOTX 081151
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
451 AM PDT THU MAY 8 2025
KEY MESSAGES
- DRY WITH WIND GUSTS UP TO 20 MPH TODAY.
- MILD TEMPERATURES FRIDAY AND SATURDAY.
- COOLER WITH PERIODS OF SHOWERS AND AFTERNOON THUNDERSTORMS
SUNDAY THROUGH TUESDAY
SYNOPSIS
TEMPERATURES COOL NEAR NORMAL VALUES TODAY THEN REBOUND BACK
INTO THE 70S TO LOWER 80S FRIDAY AND SATURDAY. COOLER AND
WETTER WEATHER PATTERN RETURNS LATE SATURDAY AND INTO EARLY NEXT
WEEK WITH SEVERAL OPPORTUNITIES FOR SHOWERS AND AFTERNOON
THUNDERSTORMS.
DISCUSSION
TODAY AND TONIGHT: PLENTY OF SUNSHINE TO BE FOUND ACROSS THE INLAND
NW TODAY WITH THE POST FRONTAL AIR MASS VERY DRY. THIS IS EVIDENT
BY THE AMOUNT OF DARKENING ON THE MORNING WATER VAPOR AND ITS
NOT LIKE THERE IS MUCH MOISTURE TO MIX OUT WITH THE ONLY SITE IN
THE INLAND NW THAT REPORTED A 0.01" COMING FROM WINTHROP, WA.
PWATS PLUMMET BACK NEAR 0.20" AND DESPITE TEMPERATURES COOLING
BACK INTO THE 60S AND LOW 70S, RELATIVE HUMIDITIES WILL ONCE
AGAIN FALL INTO THE TEENS TO TWENTIES WHICH IS NOT TYPICAL FOR
MAY. WINDS WILL REMAIN BREEZY, ESPECIALLY IN THE MORNING AND
EARLY AFTERNOON AND DECREASE LATE IN THE DAY INTO THE EVENING.
WIND GUSTS OF 15 TO 20 MPH ARE EXPECTED. CLEAR SKIES, LIGHT
WINDS, AND LOW DEWPOINTS WILL ALLOW FOR STRONG RADIATIONAL
COOLING OVERNIGHT WITH 30S AND 40S BY FRIDAY MORNING. PATCHY
FROST HAS BEEN ADDED TO THE NORTHERN MOUNTAIN VALLEYS AND A FEW
OF THE COLD SPOTS ACROSS THE UPPER COLUMBIA BASIN. BE SURE TO
PROTECT SENSITIVE PLANTS.
FRIDAY AND SATURDAY: THE REGION WILL BE IN A BATTLE GROUND BETWEEN
HIGH PRESSURE ADVANCING NORTHWARD FROM THE DESERT SOUTHWEST AND
LOW PRESSURE RECLAIMING THE OFFSHORE WATERS. THE RIDGE AND
STABLE WEATHER PATTERN LOOKS TO WIN THE TUG OF WAR ON FRIDAY
DELIVERING 10 DEGREES OF WARMING AND MOSTLY DRY CONDITIONS. THE
ONE CAVEAT WILL BE INCREASING INSTABILITY OVER THE FAR SOUTHEAST
(NE OREGON TO CAMAS PRAIRIE) WHICH HAS A 10% CHANCE FOR A STRAY
T-STORM OR TWO. THIS COMES WITH VERY LOW CONFIDENCE AND IS NOT
MENTIONED IN THE FORECAST AT THIS TIME BUT WILL BE MONITORED
CLOSELY FOR FUTURE TRENDS. BY SATURDAY, THINKING THERE WILL BE
SHORTWAVES COMING THROUGH THE SOUTHWEST FLOW ALOFT TO ALLOW FOR
SHOWERS AND A FEW THUNDERSTORMS TO DEVELOP OVER SOUTHEASTERN WA
AND THE LOWER IDAHO PANHANDLE WHILE A COLD FRONT BRINGS
INCREASING SHOWERS TO W WA AND THE CASCADE CREST. THE REMAINDER
OF CENTRAL/EASTERN WA AND N ID LOOK TO HAVE ONE MORE DRY DAY
WITH MILD TEMPERATURES UNDER INCREASING CLOUD COVER. HIGH
TEMPERATURES HAVE COME DOWN 1-2 DEGREES FROM THE PREVIOUS
FORECAST AND NOW ARE NEAR OR A DEGREE COOLER THAN FRIDAY
INDICATIVE OF THE OFFSHORE TROUGH STARTING TO WIN THE BATTLE.
WINDS BY SATURDAY EVENING WILL BECOME GUSTY DOWN THE EAST SLOPES
AND CASCADE GAPS AS THE MARINE LAYER DEEPENS AND COOLER AIR
BEGINS TO SEEP INLAND.
SUNDAY AND MONDAY: THERE IS HIGH CONFIDENCE FOR LOW PRESSURE TO
CARVE INTO THE NORTHWEST DELIVERING MORE TYPICAL SPRING
TEMPERATURES AND HUMIDITY LEVELS. SHOWERS WILL RETURN TO MOST
AREAS ACROSS NORTH IDAHO, NORTHEASTERN WA, AND ALONG THE CASCADE
CREST. LOWEST RAIN CHANCES WILL BE IN THE IMMEDIATE LEE OF THE
CASCADES AROUND CHELAN, WENATCHEE, AND INTO THE SOUTHWESTERN
BASIN AROUND MOSES LAKE. UNFORTUNATELY, THIS AREA HAS BEEN
LARGELY SKIPPED OVER WITH PREVIOUS RAIN EVENTS AND REALLY COULD
USE THE MOISTURE THE MOST. NORTH IDAHO, NE WASHINGTON, AND THE
CASCADE CREST COME WITH A 70-80% CHANCE TO RECEIVE AT LEAST A
WETTING RAIN (0.10") OVER THIS 2 DAY PERIOD, 50-70% CHANCE FOR
AT LEAST 0.25", AND 20-40% CHANCE FOR 0.50" OR MORE. THE EASTERN
COLUMBIA BASIN INCLUDING SPOKANE TO RITZVILLE COMES WITH A
50-60% FOR A TENTH, 20-40% CHANCE FOR A 0.25", AND 5-15% FOR
0.50". MOSES LAKE, WENATCHEE, AND CHELAN ONLY HAVE A 15-20%
CHANCE FOR A TENTH AND 5-10% CHANCE FOR 0.25". OMAK, THE
OKANOGAN VALLEY, AND METHOW VALLEY CARRY HIGHER PROBABILITIES
THAN CHELAN BUT LOWER THAN THE CASCADE CREST AND KETTLE
MOUNTAINS TO THE EAST THOUGH I WOULDN'T RULE THESE PROBABILITIES
TO INCREASE AS THERE WILL BE LITTLE TO NO WESTERLY FLOW AND
RAIN SHADOWING IN THIS PATTERN. AFTERNOON THUNDERSTORMS WILL
ALSO BE A CONCERN WITH POTENTIAL IMPACTS BEING LIGHTNING AND
HEAVY DOWNPOURS WITH ANY CELLS.
TUESDAY THROUGH THURSDAY: QUITE THE SHIFT IN THE LARGE SCALE
PATTERN OVER THE WESTERN TWO-THIRDS OF THE US WHICH WILL
FEATURE A BROAD UPPER-LEVEL TROUGH. THE LOW OVER THE INLAND NW
SUNDAY AND MONDAY WILL BE WELL ON ITS WAY INTO THE UPPER
MIDWEST AND THE REGION WILL BE IN A POSITION FOR WEAKER WAVES
DROPPING OUT THE NORTHWEST THROUGH. WHILE INSTABILITY PARAMETERS
WILL BE ON THE DECLINE, THE PATTERN WILL CONTINUE TO SUPPORT
MENTION OF SHOWERS EITHER FROM AFTERNOON HEATING OR DEVELOPING
ALONG THE MIDLEVEL WAVES FROM THE NORTHWEST. GREATEST RISK LOOKS
TO BE ON TUESDAY AND WEDNESDAY WITH A GENERAL DRYING TREND BY
THURSDAY. ROUGHLY 80% OF THE CLUSTERS AGREE WITH THIS NOTION AND
IS REFLECTED IN THE CPC 6-10 DAY OUTLOOK WHICH LEANS TOWARD
COOLER AND WETTER CONDITIONS FOR MAY 13-17TH. /SB
AVIATION
12Z TAFS: VFR CONDITIONS. HIGH CIRRUS THROUGH THE PERIOD.
DECREASING WINDS ESPECIALLY THIS AFTERNOON AND EVENING.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE IN VFR CONDITIONS.
-----------------------
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 40 77 50 76 49 65 / 0 0 0 0 10 30
COEUR D'ALENE 38 76 48 76 48 65 / 0 0 0 0 20 40
PULLMAN 38 77 50 73 48 63 / 0 0 0 0 20 40
LEWISTON 45 83 54 81 53 70 / 0 0 0 0 20 40
COLVILLE 32 74 44 74 43 66 / 0 0 0 0 10 40
SANDPOINT 36 74 47 74 48 64 / 0 0 0 0 20 40
KELLOGG 39 76 52 73 50 64 / 0 0 0 0 30 50
MOSES LAKE 39 79 49 79 48 70 / 0 0 0 0 0 10
WENATCHEE 45 78 53 75 48 68 / 0 0 0 0 0 10
OMAK 36 76 48 75 44 69 / 0 0 0 0 0 10
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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