976
FXUS66 KOTX 041810
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1110 AM PDT FRI SEP 4 2026
KEY MESSAGES
- COOL AND SHOWERY WEATHER EXPECTED THROUGH LABOR DAY WEEKEND
WITH ISOLATED THUNDERSTORMS.
- A WARMING AND DRYING TREND RETURNS AROUND THE MIDDLE OF NEXT
WEEK.
SYNOPSIS
ACTIVE WEATHER STICKS AROUND THROUGH LABOR DAY WEEKEND WITH
SCATTERED SHOWERS, ISOLATED THUNDERSTORMS, AND COOLER THAN NORMAL
TEMPERATURES. A WARMING AND DRYING TREND COMMENCES AROUND THE MIDDLE
OF NEXT WEEK AS HIGHER PRESSURE RETURNS TO THE REGION.
DISCUSSION
FRIDAY THROUGH MONDAY: AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SPIN
OVER THE INLAND NORTHWEST KEEPING TEMPERATURES SEASONABLY COOL AND
THE WEATHER ACTIVE. THE CENTER OF THE LOW IS SITUATED OVER NORTHWEST
OREGON. A DEFORMATION BAND FORMING ON THE EASTERN FLANK WILL SWING
ACROSS THE IDAHO PANHANDLE THROUGH EARLY FRIDAY MORNING.
PERIODS OF LIGHT TO MODERATE RAIN WILL SOAK THE GROUND FROM THE
LEWISTON- CLARKSTON VALLEY UP ACROSS THE PALOUSE REGION, AND
ACROSS THE SOUTHERN TO CENTRAL IDAHO PANHANDLE. TOTAL
PRECIPITATION UNDER THIS BAND WILL BE UP TO BETWEEN 0.50-1.0
INCHES ACROSS MUCH OF THIS AREA. MUCH NEEDED RAINFALL AFTER A
WARMER AND DRIER THAN AVERAGE JUNE- AUGUST. STEADY RAIN WILL
TRANSITION TO SHOWERS FOR FRIDAY AFTERNOON. SHOWERS WILL FAVOR
THE HIGHER TERRAIN, BUT EVEN THE COLUMBIA BASIN WILL SEE AT
LEAST ISOLATED SHOWERS. WEAK SURFACE BASED INSTABILITY OVER THE
CASCADES AND THE MOUNTAINS OF NORTH-CENTRAL WASHINGTON WILL
BRING AN ISOLATED THREAT FOR THUNDERSTORMS. ANY STORMS THAT
DEVELOP THIS AFTERNOON WILL BE CAPABLE OF BRIEF HEAVY RAIN, AND
INFREQUENT LIGHTNING STRIKES.
THE CENTER OF THE UPPER LEVEL LOW WOBBLES AROUND OVER THE NORTHWEST
REGION THROUGH AT LEAST SUNDAY. THIS WILL KEEP THE REGION
CONDITIONALLY UNSTABLE. BEST CHANCES FOR SHOWERS WILL COME IN THE
AFTERNOON WITH DIURNALLY FORCED SHOWERS. PERTURBATIONS THAT
SPIN AROUND THE UPPER LOW WILL ALSO HELP TO FORCE PRECIPITATION.
THE NEXT ONE LOOKS TO BE AROUND SATURDAY AFTERNOON WITH MORE
ORGANIZED DEVELOPMENT OF SHOWERS ACROSS EXTREME EASTERN
WASHINGTON INTO THE IDAHO PANHANDLE. THEN ANOTHER ROUND WITH
ANOTHER SHORTWAVE SPINNING IN ACROSS THESE SAME AREAS FOR SUNDAY
NIGHT INTO MONDAY. IT'S REALLY TOUGH TO PIN POINT HOW MUCH
PRECIPITATION WILL FALL AS THERE WILL BE SOME CONVECTIVE
ELEMENTS IN PLACE WITH MODESTLY STEEP LAPSE RATES AT MID LEVELS
OF THE ATMOSPHERE. THERE WILL BE THE POTENTIAL FOR HEAVIER
SHOWERS THAT BRINGS WETTING RAINS (GREATER THAN A TENTH OF AN
INCH), AND THIS WILL ALL LARGELY BE BENEFICIAL FOR THE ONGOING
DROUGHT ACROSS THE REGION. WHERE RAIN MAY BE OF A NUISANCE IS IF
IT GETS HEAVY OVER A RECENT BURN SCAR, AND THAT WOULD BRING A
SMALL CHANCE FOR MINOR FLOODING IMPACTS.
THE UPPER LEVEL LOW GETS PICKED UP BY THE POLAR JET STREAM AROUND
LATE SUNDAY INTO MONDAY. A 30-60% CHANCE OF PRECIPITATION WILL
CONTINUE ACROSS THE EASTERN HALF OF THE REGION WHILE THE CASCADES
BEGINS TO DRY OUT. TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS
GENERALLY IN THE UPPER 60S TO MID 70S THROUGH LABOR DAY WEEKEND.
BREAKS IN THE CLOUD COVER OVERNIGHT MAY YIELD PATCHY FOG AS RAIN
WILL MOISTEN UP THE BOUNDARY LAYER. THE NEXT FEW DAYS IS A REMINDER
THAT THE FALL SEASON IS RIGHT AROUND THE CORNER.
MONDAY NIGHT THROUGH FRIDAY: THE INLAND NORTHWEST REMAINS UNDER A
BAGGY LONGWAVE TROUGH OF LOW PRESSURE INTO NEXT WEEK. A LONGWAVE
HIGH PRESSURE AREA WILL BE SITUATED OVER THE CENTRAL PORTION OF THE
U.S. THE TROUGH AXIS WILL BE SITUATED MORE OFFSHORE AND IT LOOKS TO
DIG AROUND THE TUESDAY INTO WEDNESDAY TIMEFRAME. THE EQUATORIAL
PACIFIC IS ALSO QUITE ACTIVE WITH TROPICAL SYSTEMS, AND THERE'S SOME
INDICATION THAT ONE OF THESE SYSTEMS COULD GET ENTRAINED INTO THE
MID LATITUDES OFF OF THE COAST OF BAJA CALIFORNIA BY WEDNESDAY. THIS
TENDS TO MUCK UP THE MODELS WITH REDUCED CONFIDENCE IN THE EXTENDED
FORECAST. THE GENERAL CONSENSUS, HOWEVER, IS THAT THE RIDGING IN THE
CENTRAL U.S. WILL BUILD IN TOWARD THE INLAND NORTHWEST WITH A
WARMING AND DRYING TREND AROUND MID WEEK. WE WILL NEED TO KEEP AN
EYE ON THAT TROPICAL MOISTURE FOR LATER IN THE WEEK THOUGH AS
THERE IS A POSSIBILITY FOR SOME OF THAT TO GET ENTRAINED AND
ADVECT NORTHWARD INTO THE REGION. EARLY INDICATIONS IS THAT IF
THIS HAPPENS, IT WILL BE A SMALL FRACTION AND WON'T BE MORE THAN
A MINOR IMPACT. /SVH
AVIATION
18Z TAFS: SPOTTY SHOWERS WILL CONTINUE TO LINGER OVER NORTHERN
WA AND NORTH ID THIS MORNING AND AFTERNOON, BUT ARE NOT EXPECTED
TO IMPACT TAF SITES. FEW TO SCATTERED LOW CLOUDS ARE PRESENT
ACROSS THE NORTHERN MOUNTAINS, EXTREME EASTERN WA, AND NORTH ID
INCLUDING AT KGEG, KSFF, AND KCOE. KPUW IS THE ONE SITE STILL
SEEING MVFR CLOUD DECKS WITH BROKEN COVERAGE. CEILINGS ARE
EXPECTED TO LIFT FOR ALL SITES AS SHOWERS CONTINUE TO MOVE
NORTHWARD. ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED OVER
THE CASCADES AND MOUNTAINS OF NORTH-CENTRAL WASHINGTON, BUT ARE
NOT FORECAST TO MOVE OVER TAF SITES.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
FOR IMPROVING CEILINGS OVER EASTERN WA/ID TAF SITES AS SHOWERS
CONTINUE MOVING NORTHWARD. LOW CONFIDENCE ON THUNDERSTORMS THIS
AFTERNOON IMPACTING ANY TAF SITES.
-----------------------
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 67 44 70 46 72 48 / 40 10 20 20 10 40
COEUR D'ALENE 67 44 71 46 73 48 / 50 0 30 20 30 50
PULLMAN 65 41 68 41 70 42 / 50 0 20 10 20 50
LEWISTON 70 51 73 52 74 54 / 30 10 30 10 20 60
COLVILLE 67 39 71 39 74 42 / 30 0 30 30 10 30
SANDPOINT 65 42 68 43 71 45 / 40 0 30 20 30 40
KELLOGG 63 42 68 45 70 47 / 50 10 40 20 40 60
MOSES LAKE 71 45 72 46 76 48 / 10 0 20 20 10 30
WENATCHEE 70 52 71 54 76 58 / 20 10 40 20 10 30
OMAK 70 46 72 47 74 49 / 10 10 30 40 10 20
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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