873
FXUS66 KPDT 261924
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1224 PM PDT WED AUG 26 2026
KEY MESSAGES
1. TEMPERATURES TODAY AND WEDNESDAY WILL REMAIN ABOVE SEASONAL
NORMAL THROUGH WEDNESDAY.
2. AN UPPER LEVEL LOW APPROACHING THE REGION WILL BRING INCREASED
WINDS TODAY INCREASING FIRE WEATHER CONCERNS.
3. CONTINUED SOUTHWEST FLOW WITH BREEZY CONDITIONS THROUGH THE
REMAINDER OF THE WEEK INTO THE WEEKEND.
DISCUSSION
CURRENT SATELLITE SHOWS MOSTLY CLEAR SKIES WITH A FEW LINGERING
CLOUDS. CONDITIONS WILL REMAIN DRY AND WARM THROUGH THE DAY TODAY
WITH INCREASING CLOUD COVER LATER IN THE AFTERNOON AND EVENING.
MODELS SHOW THE RIDGE OF HIGH PRESSURE REMAINING OVER THE REGION
TODAY AHEAD OF THE NEXT SYSTEM. LOOKING AT IN HOUSE CALCULATIONS,
TEMPERATURES ARE EXPECTED TO BE NEAR 15 DEGREES ABOVE SEASONAL
NORMAL TODAY. LOOKING AT HEATRISK PROBABILITIES, TODAY WILL BE THE
PEAK WITH 80-90% PROBABILITIES OF AREAS REACHING MODERATE HEATRISK
(LEVEL 2 OF 4) ACROSS THE COLUMBIA BASIN. THERE IS ALSO A LOW TO
MEDIUM RISK OF AREAS IN THE COLUMBIA BASIN SEEING MAJOR HEATRISK
(LEVEL 3 OF 4) WITH 30-50% PROBABILITIES. MODERATE HEATRISK AFFECTS
THOSE WHO ARE SENSITIVE TO HEAT, ESPECIALLY THOSE WITHOUT
COOLING/HYDRATION, WHILE MAJOR HEATRISK AFFECTS ANYONE WITHOUT
COOLING/HYDRATION.
MODELS TODAY SHOW THE LEADING EDGE OF THE UPPER LEVEL LOW BEGINNING
TO MAKE ITS WAY ONSHORE. AS THE LOW BEGINS TO TRAVERSE EAST, THE
LEADING EDGE OVER THE CASCADES WEDNESDAY WILL BRING A TIGHTENING OF
THE SURFACE PRESSURE GRADIENTS. WINDS WILL BE INCREASED THROUGH THE
COLUMBIA RIVER GORGE, KITTITAS VALLEY AND ALONG PORTION OF THE
SIMCOE HIGHLANDS AND FOOTHILLS OF THE SOUTHERN BLUES. NBM RAW
ENSEMBLES SHOWS 80-90% PROBABILITIES THAT WINDS WILL BE 15-20 WITH
SOME ISOLATED 25 MPH SUSTAINED WINDS WITH GUSTS TO NEAR 30-35 MPH.
THE INCREASE IN THE WINDS WILL ALSO RAISE SOME FIRE WEATHER CONCERNS
TODAY. WITH THAT, A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR
ISOLATED AREAS WITHIN THE AFOREMENTIONED PLACES FOR CRITICAL FIRE
WEATHER BETWEEN 1100-2000 (8PM) WEDNESDAY DUE TO WINDS AND LOW
RELATIVE HUMIDITY. WHILE NOT WIDESPREAD, THIS WILL AFFECT A FEW OF
THE FIRES ALREADY ON THE LANDSCAPE AS WELL AS ANY NEW FIRE THAT MAY
OCCUR IN THESE AREAS.
LOOKING INTO THE LONGER TERM USING DETERMINISTIC MODELS SHOWS THE
UPPER LEVEL LOW TO MOVE OFF TOWARDS THE NORTH AND A TROUGH TO REMAIN
OVER THE REGION THROUGH THE WEEKEND. THIS WILL BRING CONTINUED
SOUTHWEST FLOW ACROSS THE REGION WITH DAILY BREEZY CONDITIONS
THROUGH THE GAPS. CLUSTERS ARE ALSO IN DECENT AGREEMENT OVER THE
WEEKEND WITH THE MAIN VARIANCE BEING THE AMPLITUDE OF THE TROUGH.
REGARDLESS OF THIS, CONDITIONS WILL REMAIN DRY AND BREEZY WITH
COOLER TEMPERATURES AND HIGHER HUMIDITIES THROUGH MID-WEEK
ONWARDS.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
MOSTLY VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. SITES
RDM/BDN/ALW WILL SEE A 20-40% CHANCE OF SMOKE IMPACTS OVERNIGHT,
ESPECIALLY WHEN WINDS WEAKEN IN THE OVERNIGHT PERIOD. WINDS
WILL INCREASE TO 12-20KTS WITH GUSTS 20-30KTS AT MOST SITES THIS
AFTERNOON, WHICH WILL BECOME 12KTS OR LESS OVERNIGHT. SITES
ALW/PSC ARE EXPECTED TO REMAIN AROUND 12KTS OR LESS THROUGH THE
PERIOD. LAWHORN/82
FIRE WEATHER
BREEZY CONDITIONS THROUGH THE KITTITAS VALLEY,
COLUMBIA RIVER GORGE, SIMCOE HIGHLANDS AND FOOTHILLS OF THE BLUES
COUPLED WITH LOW RELATIVE HUMIDITY WILL KEEP THE AREAS UNDER
ELEVATED FIRE WEATHER CONCERNS THROUGH THE DAY TODAY. ISOLATED AREAS
WITHIN THESES MENTIONED LOCATIONS WILL SEE CRITICAL CONDITIONS.
WHILE THIS IS NOT A WIDESPREAD EVENT, WITH THE FIRE ON THE LANDSCAPE
AND ANY NEW FIRE THAT MAY OCCUR, AN SPECIAL WEATHER STATEMENT
HAS BEEN ISSUED BETWEEN 1100-2000 (8PM) TODAY. AS WE MOVE ON TO
TOMORROW (THURSDAY), WINDS WILL REMAIN ELEVATED. HOWEVER, DUE TO
THE UPPER LEVEL SYSTEM, TEMPERATURES WILL DECREASE AND RELATIVE
HUMIDITY WILL INCREASE OUT OF CRITICAL NUMBERS.
PRELIMINARY POINT TEMPS/POPS
PDT 56 83 47 81 / 0 0 0 0
ALW 63 85 54 83 / 0 0 0 0
PSC 63 88 52 86 / 0 0 0 0
YKM 61 87 55 84 / 0 0 0 0
HRI 63 86 54 85 / 0 0 0 0
ELN 55 78 49 76 / 0 0 0 0
RDM 50 84 42 82 / 0 0 0 0
LGD 56 89 48 86 / 0 0 0 0
GCD 56 91 52 88 / 0 0 0 0
DLS 63 81 57 82 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...AIR QUALITY ALERT UNTIL NOON PDT FRIDAY FOR WAZ026-522-523.
OR...AIR QUALITY ALERT UNTIL NOON PDT FRIDAY FOR ORZ041-505-506-
509>511.
DISCUSSION...90
AVIATION...82
FIRE WEATHER...90
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