169
FXUS66 KOTX 201742
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1042 AM PDT WED AUG 20 2025
KEY MESSAGES
- DRY AND BREEZY SOUTHWEST WINDS ON WEDNESDAY WITH ELEVATED FIRE
WEATHER CONDITIONS.
- WARM AND DRY THROUGH THE WEEKEND WITH WIDESPREAD MODERATE FOR
EASTERN WASHINGTON AND NORTH IDAHO AND WIDESPREAD MAJOR
HEATRISK FOR CENTRAL WASHINGTON.
SYNOPSIS
WINDS WILL BE BREEZY ON WEDNESDAY WITH ELEVATED FIRE WEATHER
CONDITIONS. THEN, A PERSISTENT RIDGING PATTERN WILL LEAD TO A
WARMING AND DRYING TREND ACROSS THE REGION THURSDAY THROUGH
EARLY NEXT WEEK.
DISCUSSION
WEDNESDAY: THE INLAND NORTHWEST REMAINS UNDER SOUTHWESTERLY FLOW
ALOFT, WITH AN UPPER-LEVEL RIDGE ANCHORED OVER THE CENTRAL UNITED
STATES AND A CLOSED LOW TRACKING ACROSS NORTHERN BRITISH COLUMBIA.
MID AND UPPER LEVEL CLOUDS ARE INCREASING ACROSS WESTERN AND CENTRAL
WASHINGTON AS A WEAK MID-LEVEL FRONT ASSOCIATED WITH THE LOW MOVES
INLAND. THIS FRONT WILL CROSS THE CASCADES WEDNESDAY MORNING,
BRINGING A NOTICEABLE INCREASE IN SOUTHWEST WINDS ACROSS EASTERN
WASHINGTON AND NORTH IDAHO BY LATE MORNING INTO THE AFTERNOON.
SUSTAINED WINDS OF 10-20 MPH WITH GUSTS OF 20-30 MPH ARE EXPECTED
DURING THIS TIME.
PRECIPITATION IS NOT EXPECTED WITH THIS FRONT, THOUGH A FEW
SPRINKLES CANNOT BE RULED OUT OVER FAR NORTHEAST WASHINGTON AND
NORTH IDAHO. AHEAD OF THE FRONT, PRECIPITABLE WATER VALUES WILL
RANGE FROM 100-140% OF NORMAL, DROPPING TO 40-80% OF NORMAL BEHIND
IT BY WEDNESDAY EVENING AS MUCH DRIER AIR MOVES IN. ELEVATED FIRE
WEATHER CONDITIONS ARE ANTICIPATED DURING THE AFTERNOON, HOWEVER,
RELATIVE HUMIDITY VALUES SHOULD REMAIN HIGH ENOUGH TO MITIGATE
WIDESPREAD CRITICAL CONDITIONS. THAT SAID, BRIEF POCKETS OF CRITICAL
FIRE WEATHER ARE POSSIBLE, PARTICULARLY OVER THE WATERVILLE PLATEAU
AND WESTERN COLUMBIA BASIN, WHERE THERE IS A 30% CHANCE OF MINIMUM
RH BELOW 20% AND SUSTAINED WINDS ABOVE 15 MPH BETWEEN 3 PM AND 7 PM.
THURSDAY THROUGH TUESDAY: MODELS ARE IN GOOD AGREEMENT THAT THE
UPPER-LEVEL LOW WILL SHIFT EAST THROUGH CENTRAL CANADA ON THURSDAY
AS ANOTHER UPPER-LEVEL LOW APPROACHES THE ALASKAN PANHANDLE. THIS
PATTERN WILL ALLOW THE FOUR CORNERS HIGH TO AMPLIFY NORTHWARD,
LEAVING THE PACIFIC NORTHWEST SANDWICHED BETWEEN THESE TWO LOWS AND
UNDER THE INFLUENCE OF A STRENGTHENING RIDGE FOR SEVERAL DAYS.
HEAT WILL BE THE PRIMARY CONCERN. TEMPERATURES WILL TREND WARMER
THROUGH SATURDAY, WITH HIGHS REACHING THE MID 90S TO LOW 100S AND
VERY LITTLE SPREAD BETWEEN THE 25TH AND 75TH PERCENTILE TEMPERATURE
FORECASTS IN THE NATIONAL BLEND OF MODELS (NBM) THROUGH MONDAY.
MODERATE (ORANGE) HEATRISK WILL BECOME WIDESPREAD ACROSS THE INLAND
NORTHWEST BY SATURDAY, WITH LOCALLY MAJOR (RED) CONDITIONS IN THE
WENATCHEE AREA AND L-C VALLEY. LITTLE CHANGE IN THE RIDGE POSITION
WILL PROLONG THE HEAT INTO EARLY NEXT WEEK, WITH MAJOR HEATRISK
BECOMING MORE WIDESPREAD IN CENTRAL WASHINGTON AND POCKETS OF
EXTREME (MAGENTA) HEATRISK AROUND WENATCHEE. EXTREME HEATRISK IS
RARE AND TYPICALLY OCCURS WHEN SEVERAL CONSECUTIVE DAYS OF HOT
DAYTIME TEMPERATURES COMBINE WITH WARM OVERNIGHT LOWS (MID 60S TO
LOW 70S). THIS LEVEL AND DURATION OF HEAT WILL POSE A SIGNIFICANT
DANGER TO ANYONE WITHOUT ADEQUATE COOLING OR HYDRATION.
BY MONDAY AND TUESDAY, DETERMINISTIC MODELS BEGIN TO SUGGEST THE
NORTHWARD ADVECTION OF MONSOONAL MOISTURE AS A WEAK WEATHER SYSTEM
APPROACHES THE PNW COAST. THIS COULD BRING THE POTENTIAL FOR
ELEVATED CONVECTION, RAISING THE RISK OF NEW FIRE STARTS. CONFIDENCE
REMAINS LOW, WITH ONLY A 5-10% CHANCE OF THUNDERSTORMS IN THE NBM AT
THIS TIME. THIS WILL CONTINUE TO BE MONITORED CLOSELY IN THE COMING
DAYS. /VMT
AVIATION
18Z TAFS: VFR CONDITIONS WILL PREVAIL FOR ALL SITES THROUGH THE
NEXT 24 HOURS. A WEAK WEATHER SYSTEM MOVING THROUGH WILL BRING
PASSING MID AND HIGH CLOUDS ALONG WITH BREEZY WEST WINDS WITH
GUSTS UP TO 20KTS ANTICIPATED. WINDS WILL SUBSIDE AFTER SUNSET
TONIGHT (AROUND 03Z).
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HIGH CONFIDENCE
FOR CONDITIONS TO REMAIN VFR.
-----------------------
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:/WEATHER.GOV/OTX/AVNDASHBOARD
PRELIMINARY POINT TEMPS/POPS
SPOKANE 84 53 87 54 91 57 / 0 0 0 0 0 0
COEUR D'ALENE 84 53 87 54 90 58 / 0 0 0 0 0 0
PULLMAN 80 51 85 51 91 53 / 0 0 0 0 0 0
LEWISTON 90 61 93 60 98 63 / 0 0 0 0 0 0
COLVILLE 85 44 86 45 90 48 / 0 0 0 0 0 0
SANDPOINT 82 49 85 50 87 52 / 0 0 0 0 0 0
KELLOGG 81 57 83 58 90 60 / 0 0 0 0 0 0
MOSES LAKE 87 52 88 55 94 59 / 0 0 0 0 0 0
WENATCHEE 85 60 88 63 93 67 / 0 0 0 0 0 0
OMAK 88 55 88 56 93 59 / 0 0 0 0 0 0
OTX WATCHES/WARNINGS/ADVISORIES
WA...NONE.
ID...NONE.
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