536
FXUS66 KPDT 222236
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
336 PM PDT FRI MAY 22 2026
KEY MESSAGES
1. DRY AND WARM CONDITIONS WILL PERSIST THROUGH THE WEEKEND
2. BREEZY TO WINDY THROUGH THE GAPS SATURDAY AND AGAIN MONDAY
3. PATTERN SHIFT MONDAY WILL BRING CHANCES MOUNTAIN SHOWERS
BECOMING MORE WIDESPREAD TUESDAY ONWARDS
DISCUSSION
CURRENT SATELLITE SHOWS SOME FAIR WEATHER CUMULUS CLOUDS FORMING
OVER SOME OF THE RIDGELINES THROUGHOUT THE REGION. OTHERWISE, MOSTLY
CLEAR SKIES ARE BEING OBSERVED. WITH THE LACK OF CLOUD COVER,
TEMPERATURES TODAY ILL WARM UP STEADILY WITH TEMPERATURES REACHING
INTO THE UPPER 70S TO LOW 80S FOR THE VAST MAJORITY OF THE REGION.
WINDS WILL BE MOSTLY DIURNALLY DRIVEN AND LIGHT.
NO REAL CHANGE IN THE FORECAST THROUGH SATURDAY. MODELS REMAIN IN
LINE WITH THE UPPER LEVEL RIDGE REMAINING OVER THE REGION THROUGH AT
LEAST SATURDAY BEFORE BEING INFLUENCED BY THE NEXT SYSTEM. A SLIGHT
SHIFT FROM NORTHWEST TO WEST WINDS WILL OCCUR AS THE SYSTEM BEGINS
TO BREAK DOWN THE RIDGE. TEMPERATURES WILL CONTINUE TO WARM THROUGH
THE PERIOD WITH TEMPERATURES PEAKING SATURDAY. RAW NBM ENSEMBLES
SHOW TEMPERATURES TO BE IN THE UPPER 70S TO LOW 80S STARTING
TOMORROW WITH 70-90% PROBABILITIES. BY SATURDAY TEMPERATURES WILL BE
IN THE LOW TO MID 80S WITH 70-90% PROBABILITIES. IN OFFICE
DIFFERENCE CALCULATIONS FROM CLIMATE SHOWS TEMPERATURES TO BE 5 TO
10 DEGREES ABOVE SEASONAL NORMAL TODAY AND TOMORROW BEFORE REACHING
10-15 DEGREES ABOVE NORMAL BY SATURDAY.
AS MENTIONED ABOVE, THE BREAKDOWN OF THE RIDGE FROM NORTHWEST FLOW
TO WESTERLY FLOW WILL CAUSE A SLIGHT INCREASE IN THE WINDS,
ESPECIALLY THROUGH THE MOUNTAINS GAP AREAS. WITH THE WESTERLY OR
ZONAL FLOW, WINDS WILL BE BREEZY WITH MODELS SHOWING SUSTAINED WINDS
SPEEDS NEARING 20 MPH WITH GUSTS NEAR 30 MPH WITH 70-90% OF THE NBM
RAW ENSEMBLES IN AGREEMENT. THE LOCATIONS OF THE WINDS WILL
PRIMARILY BE THROUGH THE MOUNTAIN GAPS OF THE GORGE AND KITTITAS
VALLEY WITH 50-70% IN AGREEMENT THAT THE SOUTHERN FOOTHILLS OF THE
BLUES WILL SEE THESE WINDS AS WELL. THERE WILL BE A BRIEF SETTLING
OF THE WIND AHEAD OF THE NEXT SYSTEM THAT WILL BE ROLLING THROUGH
ON MONDAY. WINDS WILL THEN SHIFT TO THE SOUTHWEST AS THE UPPER LEVEL
TROUGH/LOW MAKES ITS WAY INTO THE REGION. AS THE FRONT MOVES INLAND,
MODELS AND IN HOUSE CALCULATIONS SHOW A TIGHTENING OF THE PRESSURE
GRADIENTS AT THE SURFACE ACROSS THE CASCADES. THIS WILL BRING
INCREASED WINDS BACK TO THE REGION LEANING MORE TOWARDS WINDY
CONDITIONS ON MONDAY THROUGH THE GORGE, KITTITAS VALLEY AND THE
SOUTHERN BLUE FOOTHILLS. NBM RAW ENSEMBLES ARE AGAIN IN 60-80%
AGREEMENT OF SUSTAINED WINDS OF 25-35 MPH WITH GUSTS OF 45-50 MPH.
WILL BE KEEPING AN EYE ON THE WINDS TO WATCH FOR THE NEED OF A
POSSIBLE ADVISORY FOR THOSE AREAS.
LASTLY, MONDAY ONWARDS THE UPPER LEVEL LOW WILL BRING COOLER
TEMPERATURES AND PRECIPITATION WITH TUESDAY BEING THE COOLEST DAY OF
THE PERIOD. IN HOUSE CALCULATIONS SHOW TEMPERATURES WILL DROP TO
NEARLY 10-15 DEGREES BELOW SEASONAL AVERAGES WITH THE NBM ENSEMBLES
SHOWING TEMPERATURES IN THE UPPER 50S TO LOW 60S WITH A FEW ISOLATED
BASIN LOCATIONS SEEING NEAR 70S WITH HIGH CONFIDENCE OF 70-90%.
PRECIPITATION IS EXPECTED TO RETURN TO THE CASCADES MONDAY AFTERNOON
WITH 0.05 INCHES OF RAIN POSSIBLE OVER THE 24 HOURS WITH 70-80%
CONFIDENCE. MODELS SHOW THE RAIN TO BECOME MORE WIDESPREAD TUESDAY
WITH PRECIPITATION EXPECTED ACROSS A VAST MAJORITY OF THE REGION.
TUESDAYS 24 HOUR RAIN TOTAL ARE NEAR 0.05 INCHES IN THE MOUNTAINS
WITH 70-80% CONFIDENCE ON 0.01-0.03 FOR SOME OF THE LOWER
ELEVATIONS. ON TUESDAY AS WELL, NBM MODELS AS WELL AS ENSEMBLES
SHOW A 20% CHANCE OF ISOLATED THUNDERSTORMS THROUGH CENTRAL OR AND
THE EASTERN MOUNTAINS AND INTO WALLOWA COUNTY BEGINNING AFTER 11 AM.
AS THE SYSTEM STEADILY MOVES SOUTHEAST, RAIN AMOUNTS WILL SLIGHTLY
DECREASE TO 0.01-0.03 INCHES WITH 60-80% CONFIDENCE AND STEADILY
DECREASE THEREAFTER WITH MAINLY LIGHT SHOWERS EXPECTED THROUGH THE
REMAINDER OF THE WEEK.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
VFR CONDITIONS WILL CONTINUE THROUGH THE REST OF THE PERIOD
WITH ABUNDANT SUNSHINE, LOW CLOUD COVER, AND DRY CONDITIONS
PREVAILING. WINDS WILL REMAIN LIGHT AND VARIABLE IN NATURE, WITH
THE EXCEPTION OF SOME STRONGER 10-20 MPH WINDS DEVELOPING IN
DLS/PDT/RDM AT AROUND 17-23Z. NO CIG OR VIS ISSUES ANTICIPATED
AT THIS TIME, WITH MOSTLY SKC TO SCT CLOUD CONDITIONS EXPECTED.
FIRE WEATHER
DRY AND WARM CONDITIONS WILL PERSIST THROUGH
THE WEEKEND WITH A SLIGHT PATTERN SHIFT TO ZONAL FLOW SATURDAY
AND THE SOUTHWEST FLOW MONDAY AS AN UPPER LEVEL TROUGH/LOW MOVES
INTO THE REGION. DAYTIME RHS WILL BE AT THEIR LOWEST OVER
WEEKEND WITH THE LOWEST RHS WILL BE SUNDAY WITH WIDESPREAD TEENS
AND LOW 20%. RHS TOMORROW WILL BE IN THE LOW TO MID TEENS
THROUGH CENTRAL OR AND THE OCHCO-JOHN DAY HIGHLAND WITH POCKETS
ALONG THE SOUTHERN BLUES AND IN THE BASIN. SUNDAY IS THE HIGHEST
DAY OF CONCERN, ESPECIALLY IN THE KITTITAS VALLEY WHERE RHS
WILL BE IN THE LOW TO MID 20% AND WINDS WILL BE BETWEEN 15-25
MPH AS WELL AS THE BASIN WITH 15-20 MPH WINDS. THIS PUTS THIS
AREA OF THE REGION IN ELEVATED FIRE WEATHER CONCERNS WHERE THE
OVERALL FIRE ENVIRONMENT SUGGESTS A MODERATE HIGH RISK FOR
SIGNIFICANT FIRES (5-19% PROBABILITIES).
PRELIMINARY POINT TEMPS/POPS
PDT 49 83 51 84 / 0 0 0 0
ALW 53 84 56 83 / 0 0 0 0
PSC 52 89 52 88 / 0 0 0 0
YKM 53 88 51 86 / 0 0 0 0
HRI 52 86 54 86 / 0 0 0 0
ELN 50 79 48 78 / 0 0 0 0
RDM 44 83 42 85 / 0 0 0 0
LGD 45 82 46 83 / 0 0 0 0
GCD 43 85 44 86 / 0 0 0 0
DLS 56 83 53 84 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...90
AVIATION...95
FIRE WEATHER...90
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