766
FXUS66 KOTX 092232
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
332 PM PDT WED SEP 9 2026
KEY MESSAGES
- BREEZY AND DRY ON THURSDAY. ELEVATED FIRE WEATHER CONDITIONS IN
DRY GRASSES. A 20 PERCENT CHANCE FOR PATCHY BLOWING DUST ALONG I-90
FROM MOSES LAKE TO RITZVILLE SOUTHWARD ACROSS THE COLUMBIA BASIN.
- COOLER BY FRIDAY. SHOWERS RETURN OVER THE WEEKEND. A 60-90 PERCENT
CHANCE FOR GREATER THAN A QUARTER OF AN INCH OF PRECIPITATION OVER
SOUTHEAST WASHINGTON INTO THE SOUTHERN TO CENTRAL IDAHO PANHANDLE
LATE SATURDAY INTO SUNDAY MORNING.
SYNOPSIS
A COLD FRONT WILL MOVE IN OVER THE INLAND NORTHWEST ON THURSDAY WITH
WEST WINDS BECOMING BREEZY BY THE AFTERNOON. VERY LITTLE
PRECIPITATION WITH THE FRONT AND THE COMBINATION OF DRY AND
BREEZY CONDITIONS WILL ELEVATED FIRE WEATHER CONDITIONS IN DRY
GRASSES. PATCHY BLOWING DUST MAY ALSO OCCUR NEAR RECENTLY WORKED
FIELDS IN THE COLUMBIA BASIN. TEMPERATURES COOL BACK TO BELOW
NORMAL BY FRIDAY. PRECIPITATION CHANCES INCREASE SATURDAY NIGHT
INTO SUNDAY MORNING.
DISCUSSION
THIS AFTERNOON THROUGH FRIDAY NIGHT: WATER VAPOR SATELLITE IMAGERY
SHOWS A DYNAMIC LOOKING FRONTAL SYSTEM DROPPING SOUTH ALONG THE
COAST OF BC. MOISTURE WILL INCREASE AHEAD OF THE FRONT ACROSS THE
NORTHWEST INTO TONIGHT WITH A +1 INCH P-WAT PLUME. THE MOISTURE
CONTENT ASSOCIATED WITH THIS PLUME LOOKS TO DECREASE WITH TIME, AND
THIS TREND WILL LIMIT MOISTURE THAT SQUEEZES OUT ALONG THE FRONT.
THERE IS VERY LITTLE MOIST ISENTROPIC ASCENT IN THE WARM SECTOR. THE
DARKENING APPARENT ON THE WATER VAPOR BEHIND THE FRONT IS ALSO
AN INDICATION OF THE DRY AIR DESCENDING ON THE BACKSIDE. THESE
FACTORS EXPLAIN WHY MODELS AREN'T PRODUCING MUCH PRECIPITATION
ALONG THE FRONT. AS SUCH, WE ARE LOOKING AT A MOSTLY DRY COLD
FRONT PASSAGE. THERE WILL BE A BAND OF MID TO HIGH LEVEL CLOUDS
BEFORE CLEARING OCCURS ON THE BACKSIDE IN THE LEE OF THE
CASCADES BY THURSDAY MORNING. WESTERLY WINDS THEN INCREASE WITH
GUSTS UP TO AROUND 25 TO 30 MPH THROUGH THE CASCADE GAPS, ONTO
THE WATERVILLE PLATEAU, AND INTO THE COLUMBIA BASIN FOR THE
AFTERNOON HOURS. RELATIVE HUMIDITY WILL LOWER DOWN TO BETWEEN
20-25%, AND THE COMBINATION OF BREEZY WINDS WITH DRY CONDITIONS
WILL ELEVATED FIRE WEATHER CONCERNS IN DRY GRASSES.
THE FLOW PATTERN OVER THE REGION BECOMES ZONAL WITH A CLOSED LOW
PRESSURE SYSTEM DEEPENING AND TRACKING SOUTH OFF OF VANCOUVER ISLAND
AND THE WASHINGTON COASTLINE ON FRIDAY. TEMPERATURES WILL BE COOLER
WITH HIGHS DROPPING BACK INTO THE UPPER 60S AND 70S IN THE POST
FRONTAL AIRMASS. THE DRIER AIR FUNNEL IN ACROSS THE REGION WILL ALSO
RESULT IN MOSTLY SUNNY SKIES FOR THE FIRST HALF OF FRIDAY. WE THEN
SEE HIGHER CLOUDS INCREASE OVER THE REGION AS THE UPPER LOW IN THE
EASTERN PACIFIC BEGINS TO BUCKLE THE FLOW AND MOISTURE INCREASES
BACK IN OVER THE REGION.
SATURDAY THROUGH SUNDAY: A BOWLING BALL OF AN UPPER LEVEL LOW WILL
TAKE AIM AT THE NORTHWEST FOR THE WEEKEND. LOOKING AT THE CLUSTER
SPACE OF ALL OF THE ENSEMBLE MEMBERS, THERE SEEMS TO BE HIGHER
CONFIDENCE ON THE STRENGTH OF THE UPPER LEVEL LOW PRESSURE SYSTEM.
THERE IS A TIGHT CLUSTERING ON THE 500 MB LOW DEEPENING TO BETWEEN
554MB TO 558MB AND TRACKING INTO NORTHWEST OREGON BY SATURDAY
AFTERNOON. WHERE UNCERTAINTY BEGINS TO CROP UP AND THE TRACK ACROSS
OREGON. THE GENERAL CONSENSUS IS THAT IT WILL TRACK ACROSS THE
NORTHERN PORTION OF THE STATE, BUT UNCERTAINTY REMAINS ON HOW
QUICKLY IT TRACKS ACROSS. ABOUT 40% OF THE ENSEMBLE MEMBERS IS A BIT
SLOWER WITH THE BEING DEAD CENTER IN THE MIDDLE OF THE OREGON-
WASHINGTON BORDER. THE SLOWER TRACK WOULD RESULT IN THE REGION BEING
UNDER THE ASSOCIATED DEFORMATION BAND LONER WITH HIGHER
PRECIPITATION AMOUNTS. THAT DEFORMATION BAND LOOKS TO SET UP FROM
THE SOUTHERN TO CENTRAL IDAHO PANHANDLE AND OVER THE SOUTHERN HALF
OF EASTERN WASHINGTON. UNDER THE AXIS OF THIS BAND WILL BE THE
POTENTIAL FOR 1.25-1.75 INCHES OF RAINFALL OVER A 24 HOUR PERIOD.
THERE WILL ALSO BE A CONVECTIVE ELEMENT PRIMARILY ACROSS SOUTHEAST
WASHINGTON INTO THE SOUTHERN IDAHO PANHANDLE FOR SATURDAY AFTERNOON
AND EVENING. THERE IS A 20% CHANCE FOR THUNDERSTORMS OVER THE
NORTHEAST BLUE MOUNTAINS, PALOUSE, L-C VALLEY, CAMAS PRAIRIE UP TO
ST. MARIES AND THE SILVER VALLEY OF IDAHO. THE CONCERN WITH
THUNDERSTORMS WILL BE FOR SHORTER DURATION HIGHER INTENSITY
RAINFALL, AND THAT WOULD INCREASE THE POTENTIAL FOR FLOODING
IMPACTS. THE RAINFALL, WHERE IT TRACKS, AND HOW QUICKLY IT
ACCUMULATES WILL BE THE MAIN CONCERN FOR POTENTIAL IMPACTS. THOSE
INCLUDE AN INCREASED POTENTIAL FOR ROCK SLIDES, AND RISES ON CREEKS
AND SMALL STREAMS, AS WELL AS PONDING OF WATER ON ROADWAYS.
NORTH TO NORTHEAST WINDS ALSO WILL INCREASE ON SATURDAY DOWN THE
OKANOGAN VALLEY, PURCELL TRENCH AND OVER THE COLUMBIA BASIN. WIND
GUSTS OF UP TO 30-35 MPH WILL BE POSSIBLE WITH THE BETTER POTENTIAL
FOR GUSTY WINDS BEING ACROSS THE OKANOGAN VALLEY ONTO THE WATERVILLE
PLATEAU. LIGHT WEIGHT OBJECTS MAY BE BLOWN AROUND. NOT MUCH OF A
RISK FOR BLOWING DUST THOUGH WITH THE PROSPECT OF RAINFALL DURING
THIS PERIOD.
SUNDAY NIGHT THROUGH WEDNESDAY: THE UPPER LEVEL LOW WILL TRACK AWAY
FROM THE REGION BY EARLY NEXT WEEK. WE ENTER INTO A DRIER NORTHWEST
FLOW UNDER A BAGGY LOW PRESSURE TROUGH. ADDITIONAL
PRECIPITATION LOOKS MINIMAL MAINLY ACROSS THE NORTHERN MOUNTAINS
NEAR CANADA AND OVER NORTH IDAHO. THERE IS HIGHER CONFIDENCE FOR
BELOW NORMAL TEMPERATURES TO PERSIST. /SVH
AVIATION
18Z TAFS: LOW CLOUDS AND FOG IN THE VALLEYS OF NORTHEAST
WASHINGTON AND THE NORTHERN IDAHO PANHANDLE WILL BURN OFF BY 19Z
THIS MORNING. A COLD FRONT WILL SAG IN ACROSS THE REGION BY
THURSDAY MORNING. HIGH CLOUDS WILL INCREASE AHEAD OF THE FRONT
TODAY INTO TONIGHT. CEILINGS ARE EXPECTED TO REMAIN ABOVE 15 KFT
WITH VFR CONDITIONS PREVAILING ONCE LOW CLOUDS BURN OFF THIS
MORNING. HIGH CLOUDS TONIGHT SHOULD LIMIT FOG AND STRATUS
FORMATION OVERNIGHT. WEST-SOUTHWEST WINDS WILL INCREASE THROUGH
THE MORNING INTO THE AFTERNOON ON THURSDAY. GUSTS UP TO 20-25
KTS WILL BE POSSIBLE ACROSS THE EXPOSED AREAS OF THE COLUMBIA
BASIN FOR THURSDAY AFTERNOON.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
FOR VFR CONDITIONS AT ALL TAF SITES THROUGH THURSDAY MORNING.
/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 53 78 46 70 49 70 / 0 0 10 0 0 10
COEUR D'ALENE 51 77 48 70 48 69 / 0 0 10 0 0 10
PULLMAN 48 76 46 67 44 68 / 0 0 10 0 0 10
LEWISTON 55 85 53 75 53 74 / 0 0 10 0 0 20
COLVILLE 46 79 42 74 42 72 / 10 0 0 0 0 10
SANDPOINT 46 74 43 67 43 66 / 0 10 10 10 0 10
KELLOGG 50 74 47 68 48 67 / 0 0 40 0 0 10
MOSES LAKE 54 81 49 73 50 73 / 0 0 0 0 0 20
WENATCHEE 63 78 53 72 58 71 / 0 0 0 0 0 40
OMAK 56 80 49 75 52 75 / 0 0 0 0 0 10
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page