392
FXUS66 KOTX 062128
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
228 PM PDT SAT JUN 6 2026
KEY MESSAGES
- FROST EXPECTED ACROSS THE NORTHERN VALLEY'S SATURDAY NIGHT
AND EARLY SUNDAY.
- RAIN MOVES IN MONDAY NIGHT WITH AN 80% CHANCE OF AT LEAST A
TENTH OF AN INCH OVER MUCH OF EXTREME EASTERN WASHINGTON AND
INTO THE IDAHO PANHANDLE. PRECIPITATION TURNS SHOWERY ON
TUESDAY WITH A 10-30% CHANCE FOR THUNDERSTORMS.
- TRENDING DRIER WEDNESDAY INTO NEXT WEEKEND WITH HIGH
CONFIDENCE FOR ABOVE NORMAL TEMPERATURES BY FRIDAY. THERE IS
A 30-50% CHANCE FOR TEMPERATURES IN THE UPPER 80S TO LOW 90S
BY NEXT SUNDAY AND WIDESPREAD MINOR TO MODERATE HEATRISK.
SYNOPSIS
GUSTY WEST TO SOUTHWEST WINDS WILL CONTINUE THROUGH SATURDAY AFTERNOON
BEFORE WINDS RELAX THROUGH IN THE EVENING. TEMPERATURES TONIGHT
WILL BE CHILLY IN THE NORTHERN MOUNTAIN VALLEYS WITH OVERNIGHT
LOWS IN THE 30S WITH FROST DEVELOPMENT EXPECTED. A WETTER STORM
SYSTEM WITH WIDELY SCATTERED LIGHT RAIN ACROSS THE REGION LATE
MONDAY INTO TUESDAY MORNING. BREEZY WITH SHOWERS TUESDAY
AFTERNOON WITH THE THREAT FOR ISOLATED THUNDERSTORMS. THE REST
OF THE WEEK WILL BE DRIER WITH WARMER TEMPERATURES.
DISCUSSION
REST OF THIS AFTERNOON THROUGH SUNDAY NIGHT: AN UPPER LEVEL LOW
PRESSURE SYSTEM WILL PUSH ACROSS THE INLAND NORTHWEST. A -27
DEGREE CELSIUS COLD POOL AT 500 MB IS MOVING INTO THE CASCADES
AND INTO THE OKANOGAN HIGHLANDS WHICH IS STEEPENING THE MID
LEVEL LAPSE RATES EXPLAINING THE DEVELOPING CONVECTION OVER
THESE AREAS. A GOOD AMOUNT OF DRIER AIR DESCENDED DOWN THE EAST
SLOPES OF THE CASCADES INTO THE COLUMBIA BASIN WITH THE COLD
FRONT AND THIS WILL MAKE IT MORE DIFFICULT FOR MUCH APPRECIABLE
PRECIPITAITON TO FALL WITH DEVELOPING CONVECTION OVER THE
COLUMBIA BASIN THIS AFTERNOON. THERE WILL BE ISOLATED SHOWERS
THAT POP UP INTO THE EVENING AND THESE SHOWERS WILL DEVELOP AND
DRIFT OVER THE SPOKANE/COEUR D'ALENE AREAS AND THE PALOUSE AS
WELL; LOW LEVELS APPEAR TO BE TOO DRY THOUGH TO SEE ENOUGH
CHARGE SEPARATION FOR THUNDERSTORMS, BUT CANNOT COMPLETELY RULE
OUT A ONE HIT WONDER WITH A PROBABILITY OF OCCURRENCE AT AROUND
10 PERCENT TODAY. THE PASAYTEN WILDERNESS AND MOUNTAINOUS AREAS
ACROSS NORTHEAST WASHINGTON WILL SEE HIGHER PROBABILITIES FOR
THUNDERSTORMS AT 20-30% CHANCE THROUGH THE REST OF THE
AFTERNOON. GOOD MIXING WITH A MODEST SOUTHWEST GRADIENT WILL
KEEP WINDS GUSTY INTO THE EARLY EVENING WITH GUSTS UP TO AROUND
25-30 MPH. SHOWERS AND WIND GUSTS WILL WANE THROUGH THE LATE
EVENING HOURS. SOME BREAKS IN THE CLOUD COVER AND DEW POINTS IN
THE LOW 30S ACROSS THE NORTHERN MOUNTAIN VALLEYS WILL BRING THE
RISK OF FROST FORMATION OVERNIGHT. MAKE SURE TO COVER ANY
SENSITIVE VEGETATION OR BRING THEM INDOORS TO PROTECT FROM FROST
DAMAGE.
SHOWERS WILL LINGER OVER THE MOUNTAINS OF NORTHEAST WASHINGTON
AND THE IDAHO PANHANDLE ON SUNDAY. ISOLATED THUNDERSTORMS IN THE
AFTERNOON IS EXPECTED FOR THE NORTHEAST MOUNTAINS CLOSER TO THE
CANADIAN BORDER AND OVER NORTH IDAHO. CHANCES WILL BE LESS THAN
TODAY AT 20 PERCENT PROBABILITY. OVERALL, TOMORROW WILL SEE
DRIER CONDITIONS OVER NORTH-CENTRAL WASHINGTON AND ACROSS THE
COLUMBIA BASIN. IT WILL STILL BE A BIT BREEZY WITH WESTERN WINDS
GUSTING UP TO AROUND 25 MPH AND TEMPERATURES 2-5 DEGREES WARMER
WITH LESS IN THE WAY OF CLOUD COVER, ESPECIALLY IN THE WESTERN
COLUMBIA BASIN, OKANOGAN VALLEY AND VALLEYS IN THE EAST SLOPES
OF THE CASCADES. TEMPERATURES ARE NOT EXPECTED TO BE AS COLD
SUNDAY NIGHT, BUT THERE COULD BE SOME ISOLATED POCKETS OF FROST
DEVELOPING FOR THE COLDER POCKETS IN THE NORTHERN MOUNTAIN
VALLEYS.
MONDAY THROUGH WEDNESDAY NIGHT: A SECOND SHORTWAVE TROUGH OF
LOWER PRESSURE WILL SWING THROUGH AROUND MONDAY NIGHT INTO
TUESDAY. THIS DISTURBANCE WILL PUSH ACROSS AS AN OPEN WAVE OFF
OF THE EASTERN PACIFIC WILL BE ACCOMPANIED BY A MORE ROBUST
P-WAT PLUME THAT TRACES ALL THE WAY BACK TO THE SUBTROPICAL
REGIONS OF THE WEST-CENTRAL PACIFIC. INTEGRATED VAPOR TRANSPORT
(IVT) OF BETWEEN 250-500 KG/M*S WILL BE DIRECTED INTO THE STATE
OF OREGON. A FRACTION OF THIS MOISTURE CONTENT THEN PUSHES
NORTHWARD ACROSS THE INLAND NORTHWEST WITH A WARM FRONTAL BAND
MONDAY NIGHT QUICKLY FOLLOWED BY THE COLD FRONT EARLY TUESDAY.
THIS STORM SYSTEM WILL LOOK DIFFERENT THAT OUR TYPICAL JUNE
PRECIPITATION EVENTS IN THAT THE PRECIPITATION ALONG THE WARM
FRONT WILL MORE LIKELY MOVE ACROSS AS A GREATER AREAL COVERAGE
STRATIFORM BAND. MILDER TEMPERATURES WITH THE WARM FRONT WILL
PUSH SNOW LEVELS UP A BIT, BUT STILL COULD SEE AN INCH OR SNOW
OF LIGHT SNOW AT THE HIGHER PEAKS ABOUT 6,000 FEET IN THE
CASCADES AS COLDER AIR MOVES IN THE COLD FRONT. OTHERWISE,
LOOKING AT RAINFALL ACROSS THE REST OF THE REGION. THERE IS AN
80-90% CHANCE FOR WETTING RAINS (AT LEAST 0.10 INCHES) ACROSS
THE EASTERN HALF OF THE FORECAST AREA, AND A 70% CHANCE OF AT
LEAST A QUARTER OF AN INCH OF RAINFALL. TUESDAY MORNING MAY BE A
BIT DAMP OUTSIDE. THE COLUMBIA BASIN WILL ALSO SEE A SHOT AT
RAIN WITH A 25-50% OF SEEING AT LEAST A TENTH OF AN INCH.
THE STRATIFORM PORTION OF THE PRECIPITATION COMES TO AN END
TUESDAY MORNING WITH THE PASSAGE OF THE COLD FRONT. WE THEN
TRANSITION TO SHOWERY PRECIPITATION IN THE AFTERNOON AND THE
MORNING RAINFALL WILL PRIME THE PUMPS FOR CONVECTION IN THE
AFTERNOON WITH SKINNY CAPE SOUNDING PROFILES. JUST ENOUGH
INSTABILITY TO GET POP UP THUNDERSTORMS ACROSS MUCH OF THE
INLAND NORTHWEST, ESPECIALLY EAST OF THE DOWNSLOPE AREAS OF THE
EAST SLOPES OF THE CASCADES. THUNDERSTORMS WILL BE PULSE TYPE
STORMS FEATURING OCCASIONAL LIGHTNING, HEAVY DOWNPOURS, AND
BRIEF SMALL HAIL. PRESSURE GRADIENTS WILL TIGHTEN AS WELL WITH
BREEZY WESTERLY WINDS FOR THE AFTERNOON. WINDS WILL BE STRONGEST
ACROSS CENTRAL WASHINGTON IN THE LEE OF THE CASCADES FROM
WENATCHEE/CHELAN INTO THE WESTERN COLUMBIA BASIN WITH GUSTS UP
TO 30-40 MPH EXPECTED.
SHOWERS WILL CONTINUE INTO WEDNESDAY PRIMARILY ALONG THE CASCADE
CREST, AND OVER THE NORTHEAST MOUNTAINS AND THE IDAHO PANHANDLE.
ISOLATED THUNDERSTORMS IN THE AFTERNOON IS EXPECTED MAINLY FOR
THE HIGHER TERRAIN OVER THE NORTHEAST MOUNTAINS INTO NORTH
IDAHO. TEMPERATURES FOR MONDAY THROUGH WEDNESDAY WILL REMAIN
BELOW NORMAL WITH HIGHS GENERALLY IN THE 60S TO LOW 70S.
THURSDAY THROUGH SATURDAY: THERE IS GOOD CONSENSUS FROM THE
MODEL ENSEMBLES FOR A RIDGE OF HIGH PRESSURE TO BE PUMPED UP
OVER THE EASTERN PACIFIC OCEAN. THIS MEANS HIGH CONFIDENCE IN
THE FAR EXTENDED PORTION OF THE FORECAST FOR TEMPERATURES
WARMING ABOVE NORMAL. SOME UNCERTAINTY REMAINS WITH WHERE THE
RIDGE AXIS WILL SET UP AND THIS WILL PLAY A PART IN HOW WARM WE
GET. THERE IS A 30% CHANCE FOR MODERATE HEATRISK TO BE A FACTOR
BY NEXT WEEKEND THOUGH WITH A 30-50% CHANCE FOR WIDESPREAD 90
DEGREE TEMPERATURES BY NEXT SUNDAY INTO THE BEGINNING OF THE
FOLLOWING WEEK IN THE COLUMBIA BASIN, IN THE LEWISTON- CLARKSTON
VALLEY, AT WENATCHEE, AND IN THE OKANOGAN VALLEY. /SVH
AVIATION
18Z TAFS: ANOTHER BREEZY DAY IS ON TAP ACROSS THE INLAND NORTHWEST
WITH PREVAILING VFR CONDITIONS EXPECTED. WIND GUSTS UP TO 25-30 KTS
EXPECTED INTO THE AFTERNOON THROUGH THE CASCADE GAPS INTO KEAT,
ACROSS THE EXPOSED AREAS OF THE COLUMBIA BASIN (KEPH/KMWH), INTO THE
SPOKANE/COEUR D'ALENE AREAS (KGEG/KSFF/KCOE), AND PALOUSE TO
LEWISTON/CLARKSTON VALLEY (KPUW/KLWS). CONDITIONALLY UNSTABLE TODAY
WITH DIURNAL HEATING RESULTING IN CONVECTIVE SHOWERS THROUGH THE
DAY. SHOWERS WILL BE MORE WIDELY SCATTERED ACROSS THE NORTHERN
MOUNTAINS WITH ISOLATED THUNDERSTORMS (15-25 PERCENT CHANCE), AND
ISOLATED SHOWERS WITH A ONLY A 10 PERCENT CHANCE FOR THUNDERSTORMS IN
THE COLUMBIA BASIN. CONVECTION IS EXPECTED TO WANE BETWEEN 03-06Z
THIS EVENING.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS AT ALL TAF SITES
THROUGH THE PERIOD. LOW CONFIDENCE IN SHOWER OR THUNDERSTORM
DEVELOPING OVER A GIVEN TAF SITE. /SVH
-----------------------
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 65 42 67 45 64 / 20 10 0 10 80 80
COEUR D'ALENE 40 62 41 67 47 61 / 20 10 0 0 80 90
PULLMAN 39 61 41 65 44 61 / 10 0 0 0 80 80
LEWISTON 47 69 47 73 51 69 / 0 0 0 0 80 80
COLVILLE 32 67 35 68 40 66 / 40 20 0 10 70 90
SANDPOINT 38 60 39 65 45 59 / 30 30 0 0 70 90
KELLOGG 41 59 40 68 47 59 / 20 20 0 0 70 90
MOSES LAKE 38 72 45 70 44 72 / 10 0 0 10 50 30
WENATCHEE 46 71 51 68 51 70 / 10 0 10 20 60 30
OMAK 38 72 43 70 46 70 / 10 0 0 10 60 80
OTX WATCHES/WARNINGS/ADVISORIES
WA...FROST ADVISORY FROM 10 PM THIS EVENING TO 11 AM PDT SUNDAY FOR
NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-OKANOGAN VALLEY-
WESTERN OKANOGAN COUNTY.
ID...FROST ADVISORY FROM 10 PM THIS EVENING TO 11 AM PDT SUNDAY FOR
NORTHERN PANHANDLE.
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