300
FXUS66 KPDT 241122
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
422 AM PDT TUE MAR 24 2026
KEY MESSAGES
- HYDRO CONCERNS CONTINUE FOR THE NEXT SEVERAL DAYS, MOSTLY
CONFINED IN THE NACHES AND YAKIMA RIVER.
- VALLEY RAIN TUESDAY, WITH DRYING CONDITIONS LATER THIS WEEK.
- BREEZY TO LOCALLY WINDY CONDITIONS DEVELOP TUESDAY AND
WEDNESDAY ALONG THE COLUMBIA BASIN THROUGH THE SIMCOE
HIGHLANDS.
DISCUSSION
AN ATMOSPHERIC RIVER CONTINUES TO DELIVER RAIN/SNOW IN THE
CASCADE MOUNTAINS THAT WILL TRAIL THROUGH THE COLUMBIA BASIN
LATER TUESDAY MORNING/AFTERNOON. CHANCES OF RAIN ACROSS THE
COLUMBIA BASIN WILL INCREASE AS WE GO THROUGH THE LATER MORNING
HOURS GOING INTO THE AFTERNOON. AREAS ACROSS THE BASIN WILL SEE
VALUES AROUND THE .1" RANGE (60-80% CHANCE), WHILE THE MOUNTAIN
CRESTS WILL SEE A HALF INCH TO INCH THROUGH WEDNESDAY (70-90%
CHANCE). SNOW LEVELS WILL BE ABOVE 9000 FEET THROUGH WEDNESDAY
MORNING UNTIL A COLD FRONT SWEEPS THROUGH THE REGION, DROPPING
LEVELS TO 2500-3500 FEET. RAIN WILL TRANSITION INTO SNOW AS A
RESULT, WITH LIGHT TO LOCALLY MODERATE RATES IN MANY PARTS OF
THE MOUNTAIN REGION.
BREEZY TO LOCALLY WINDY CONDITIONS WILL DEVELOP
AS THE FRONT SWEEPS THE REGION, BRINGING 25 TO 35 MPH GUSTS
ACROSS THE BASIN, WITH HIGHER 35-40+ MPH GUSTS IN HIGHER
ELEVATIONS. STRONGEST WINDS ARE FORECASTED TO DEVELOP LATE
TUESDAY MORNING THROUGH THE AFTERNOON HOURS. WINDS WILL
DECREASE GOING INTO THE EARLY WEDNESDAY MORNING HOURS, WITH A
SECONDARY MAXIMA DEVELOPING IN THE WEDNESDAY AFTERNOON
TIMEFRAME. WIDESPREAD ADVISORY CONFIDENCE IS CURRENTLY LOW
(20-40% CHANCE), WITH CLOSE MONITORING NEEDED FOR FUTURE TRENDS.
NBM CURRENTLY SHOWS 20-40% CHANCES OF MANY PLACES IN THE BASIN
REACHING ABOVE CRITERIA TUESDAY AND WEDNESDAY. WEDNESDAY APPEARS
TO SHOW SLIGHTLY STRONGER WINDS COMPARED TO TUESDAY.
RIDGING WILL DEVELOP FRIDAY, BRINGING DRY CONDITIONS INTO THE
AREA, ALONG WITH A WARMING TREND GOING INTO THE WEEKEND. HIGH
TEMPERATURES FROM THE NBM CURRENTLY FORECASTS MAX TEMPERATURES
TO RE-ENTER THE HIGH 60S TO LOW 70S (70-90% CHANCE) BY SUNDAY.
GUIDANCE SHOWS A WETTER PATTERN RETURNING GOING INTO EARLY NEXT
WEEK, WITH LIGHT MOUNTAIN SHOWERS AND LOWER ELEVATION RAIN AS
DETERMINISTIC MODELS BRING A TROUGH FROM THE PACIFIC ON-SHORE BY
THE MONDAY/TUESDAY TIMEFRAME.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
VFR CONDITIONS PREVAIL THROUGH ALL SITES. RAIN WILL DEVELOP OVER
ALL SITES OVER THE NEXT 24-HOURS, WITH NO FORECASTED SUB-VFR
CONDITIONS. A STRAY HEAVY SHOWER IS POSSIBLE THAT COULD VERY
BRIEFLY BRING CIGS AND/OR VIS DOWN TO SUB-VFR (15-25% CHANCE).
WINDS IN BDN/RDM EXPECTED TO INCREASE TO 20-30 KNOTS BY THE
AFTERNOON HOURS, PREVAILING THROUGH THE EVENING. ELSEWHERE,
WINDS WILL BE BETWEEN 5-15 KNOTS.
PRELIMINARY POINT TEMPS/POPS
PDT 67 43 56 30 / 60 70 40 10
ALW 64 45 56 34 / 80 90 50 20
PSC 65 45 62 33 / 60 50 10 0
YKM 62 35 55 29 / 70 30 10 0
HRI 66 44 60 32 / 50 50 10 0
ELN 55 34 49 29 / 80 30 20 10
RDM 65 38 54 21 / 30 40 0 0
LGD 64 44 54 28 / 60 90 70 30
GCD 68 48 59 28 / 30 50 40 10
DLS 61 43 57 34 / 80 70 40 10
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...95
AVIATION...95
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