330
FXUS66 KOTX 180819
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
119 AM PDT SAT APR 18 2026
KEY MESSAGES
- WARMING AND DRYING TREND FRIDAY THROUGH MONDAY.
- INCREASING RISK FOR SHOWERS AND THUNDERSTORMS TUESDAY.
- LIGHT TO MODERATE RAINS WEDNESDAY.
SYNOPSIS
WARMER AND DRIER CONDITIONS RETURN FRIDAY THROUGH THE WEEKEND.
UNSETTLED WEATHER RETURNS TUESDAY INTO WEDNESDAY NEXT WEEK.
DISCUSSION
SATURDAY-MONDAY: STABLE WEATHER CONDITIONS RETURN TO THE
INLAND NW THROUGH THE WEEKEND AND INTO EARLY NEXT COURTESY OF
HIGH PRESSURE ALOFT. THERE IS HIGH CONFIDENCE FOR WARMING
TEMPERATURES, DRY CONDITIONS, AND GENERALLY LIGHT WINDS. THE
ONLY EXCEPTION TO THE WINDS WILL BE LOCALLY BREEZY EAST WINDS
ACROSS THE PALOUSE EACH SATURDAY AND SUNDAY MORNINGS WITH SPEEDS
NEAR 15 MPH. BANDS OF MID AND HIGH LEVEL CLOUDS WILL PASS
THROUGH AT TIMES FILTERING SUNSHINE THOUGH THIS MOISTURE WILL BE
WELL ELEVATED AND REMOVED FROM DEEP LOW PRESSURE SYSTEM THAT IS
DIGGING SOUTHWARD WELL OFF THE PAC NW COAST. TEMPERATURES WILL
WARM INTO THE UPPER 50S TO 60S SATURDAY THEN 60-70S SUNDAY THEN
70S MONDAY WITH LOCAL READINGS IN THE LOW 80S AROUND MOSES LAKE,
LEWISTON, AND OMAK.
TUESDAY-THURSDAY: THERE IS INCREASING CONFIDENCE FOR AN UNSETTLED
WEATHER PATTERN OVER THE INLAND NW AS THE OFFSHORE LOW WOBBLES
INLAND AND INTERACTS WITH A SECONDARY SHORTWAVE WAVE DROPPING
SOUTH FROM BRITISH COLUMBIA. PRECISE LOCATIONS WHERE THESE
FEATURES INTERACT WILL BE IMPORTANT AND DOES COME WITH MODERATE
UNCERTAINTY. NEEDLESS TO SAY, WERE ARE BEGINNING TO SEE NUMEROUS
ENSEMBLE MEMBERS INDICATING MODERATE TO HEAVY RAINFALL FOR SOME
AREAS OF THE INLAND NW BETWEEN LATE TUESDAY AND WEDNESDAY
NIGHT. THIS WILL COME IN THE FORM OF CONVECTIVE SHOWERS AND
THUNDERSTORMS AND DOES LEAD TO SOME CONCERN FOR LOCALIZED
FLOODING. THE PATTERN WOULD ALSO SUGGEST AT LEAST A 5-15% CHANCE
FOR A FEW STRONG STORMS CAPABLE OF GUSTY OUTFLOW WINDS AND
HAIL.
TUESDAY WILL START OFF MILD AND DRY. THE OFFSHORE LOW WILL PIVOT
INTO THE REGION BY TUESDAY AFTERNOON/EVENING WITH AN INCREASING
THREAT FOR SHOWERS AND THUNDERSTORMS. THIS WILL BE THE PERIOD
OF GREATEST CONCERN FOR THUNDERSTORMS WITH GUSTY OUTFLOW WINDS
AND HAIL. HEADING INTO TUESDAY NIGHT AND WEDNESDAY, THE OFFSHORE
LOW WILL DRIFT INTO SOUTHERN WA WITH THE AFOREMENTIONED
SECONDARY SHORTWAVE ARRIVING FROM THE NORTH. THE CONCERN WILL BE
FOR AN AXIS OF MODERATE TO HEAVY RAINFALL TO DEVELOP IN THIS
DYNAMIC, SYNOPTICALLY FORCED ENVIRONMENT WITH SOME FLAVORS OF
CONVECTIVE INSTABILITY. THERE IS LITTLE TO NO WESTERLY FLOW IN
PLAY WHICH KEEPS ALL OF THE REGION AVAILABLE FOR THE AXIS OF
HEAVIER PRECIPITATION. GIVEN THE DIFFERENCES IN THE PLACEMENT OF
THIS AXIS OF RAIN, THE ENSEMBLE MEANS ARE NOT OVERLY EXCITING
BUT CLOSER EXAMINATION OF INDIVIDUAL MEMBERS SUGGEST THIS WILL
BE AN EVENT TO WATCH WITH POTENTIAL FOR OVER AN INCH OF RAINFALL
IN SOME AREAS. PROBABILITIES FAVOR NORTH IDAHO, EASTERN WA, AND
THE CASCADE CREST (30-60% CHANCE) FOR RAINFALL AMOUNTS OF 0.5"
OR MORE. THE LEE OF THE CASCADES AND BASIN HAVE A 10-30% CHANCE
FOR SIMILAR AMOUNTS; THIS IS RESPECTABLE FOR 5 DAYS OUT.
FOLKS SHOULD BE PREPARED FOR WET CONDITIONS (0.10 - 0.30") AND
CONSIDER WHAT THE IMPACTS COULD BE IF 0.50-1.50" DID FALL IN
YOUR AREA. CONSIDER WRAPPING UP OR AT LEAST PROTECT RAIN
SENSITIVE PROJECTS BY MIDDAY TUESDAY. IF YOU HAVE PLANS TO
VENTURE IN THE BACKCOUNTRY, BRING APPROPRIATE GEAR TO STAY DRY.
TEMPERATURES START OFF IN THE 70S TUESDAY, COOL INTO THE 50-60S
WEDNESDAY, THEN 50S THURSDAY. GENERAL WINDS OUTSIDE OF THUNDERSTORMS
WILL BECOME GUSTY WEDNESDAY INTO THURSDAY AS WE TRANSITION FROM
A MILD TO COOLER AIR MASS. THIS COMES WITH A 20-50% CHANCE FOR
GUSTS OF 30 MPH OR GREATER.
FRIDAY-SATURDAY: THERE IS LOW CONFIDENCE IN THIS PORTION OF THE
FORECAST WHAT THE WEATHER PATTERN WILL BE OVER THE INLAND NW.
WHAT WE DO KNOW WITH MODERATE CONFIDENCE: A RIDGE OF HIGH
PRESSURE BUILDS OVER THE GULF OF AK AND A TROUGH OF LOWER
PRESSURE SETTLE OVER CALIFORNIA. ENSEMBLES SUGGEST THE RIDGE
COULD EXPAND OVER THE INTERIOR PAC NW DELIVER WARMING AND DRYING
OR BE IMPACTED BY WAVES COMING DOWN THE EASTERN FLANK OF THE
GULF OF AK RIDGE OR DEAL WITH SHORTWAVES FROM THE
NORTH/NORTHEAST AS A BROAD AREA OF LOW PRESSURE OVER THE
CANADIAN PLAINS RETROGRADES AND ATTEMPTS TO PHASE WITH THE
CALIFORNIA LOW. MANY DIFFERENT OUTCOMES FROM MILD AND DRY TO
COOL AND WET AND BREEZY. NEEDLESS TO SAY, VERY LOW CONFIDENCE
HOW THIS PATTERN WILL SHAKE OUT WITH PROBABILITIES NEARLY SPLIT
30/30/30. /SB
AVIATION
06Z TAFS: HIGH CONFIDENCE FOR VFR CONDITIONS FOR ALL TAF SITES
AS HIGH PRESSURE DEVELOPS ALOFT. THERE WILL BE MID AND HIGH
LEVEL CLOUDS INCREASING OVER CENTRAL AND EASTERN WA IN RESPONSE
TO A SYSTEM WELL OFF THE COAST. OTHERWISE, MAINLY FAIR CUMULUS
CLOUDS IN THE IDAHO PANHANDLE BETWEEN 19-02Z. MOST SITES WILL
EXPERIENCE LIGHT WINDS OF LESS THAN 10KTS. PUW IS THE EXCEPTION
WITH A PERIOD OF EASTERLY WINDS AROUND 14KTS 10-19Z.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE PERIOD AND
INCREASED WINDS FOR KPUW.
-----------------------
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 61 38 69 44 76 47 / 0 0 0 0 0 0
COEUR D'ALENE 61 37 69 44 75 46 / 0 0 0 0 0 0
PULLMAN 60 39 69 45 74 48 / 0 0 0 0 0 0
LEWISTON 66 40 73 47 78 50 / 0 0 0 0 0 0
COLVILLE 63 34 72 41 78 44 / 0 0 0 0 0 0
SANDPOINT 58 36 67 43 73 45 / 0 0 0 0 0 0
KELLOGG 58 37 69 45 75 48 / 0 0 0 0 0 0
MOSES LAKE 68 40 77 46 81 49 / 0 0 0 0 0 0
WENATCHEE 65 43 72 50 78 54 / 0 0 0 0 0 0
OMAK 64 41 72 46 79 50 / 0 0 0 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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