970
FXUS66 KPDT 242153
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
153 PM PST TUE FEB 24 2026
DISCUSSION
A STATIONARY FRONT DRAPED ACROSS THE PACNW IN
COMBINATION WITH A MOIST SOUTHWEST FLOW ALOFT CONTINUES TO BRING
SHOWERY PRECIPITATION ACROSS THE FORECAST AREA THIS EARLY
AFTERNOON. SATELLITE AND RADAR IMAGERY OVER THE PAST FEW HOURS
HAVE SHOWN AN ATMOSPHERIC RIVER BEGINNING TO SHIFT SOUTHEAST,
WITH THE MAIN BAND OF STEADY PRECIP FOCUSED OVER SOUTHERN
PORTIONS OF OREGON. MEANWHILE, MORE SHOWERY LIGHT PRECIP BANDS
ARE DEVELOPING ALONG PORTIONS OF THE CASCADE CREST, THE LOWER
COLUMBIA BASIN AND ADJACENT VALLEYS/FOOTHILLS, AND THE NORTHERN
BLUE MOUNTAINS. CURRENTLY, ONLY LIGHT SNOW SHOWERS ARE
DEVELOPING ALONG THE WA CASCADE CREST, WHILE LIGHT RAIN AND HIGH
MTN PEAK SNOW SHOWERS ARE DEVELOPING ALONG THE OR CASCADE CREST
AND EASTERN MOUNTAINS, WHERE SNOW LEVELS ARE GENERALLY OVER
6KFT.
TODAY THROUGH WEDNESDAY AFTERNOON: SHOWERY PRECIPITATION WILL
CONTINUE ACROSS THE FORECAST AREA THROUGH WEDNESDAY MORNING,
SHIFTING FROM NORTH TO SOUTH THROUGH THE OVERNIGHT HOURS. THIS
IS DUE TO A MOSTLY OFFSHORE TROUGH CLOSING OFF INTO A LOW, WITH
THE INLAND PORTION (OVER BC), PINCHING OFF INTO A BROAD SHALLOW
TROUGH THAT WILL DROP SOUTHEAST OF THE REGION BY LATE WEDNESDAY
MORNING. WITH THE MAIN AR TO THE SOUTH OF THE FORECAST AREA,
SHOWERS WILL REMAIN LIGHT ACROSS THE LOWER ELEVATIONS, WITH ONLY
A 15-40% CHANCE OF AN ADDITIONAL 0.25 INCHES OF RAIN IN THE
LOWER ELEVATIONS (70-80% CHANCE OF AT LEAST 0.1 INCHES) THIS
AFTERNOON THROUGH EARLY TOMORROW AFTERNOON. AS FOR THE
MOUNTAINS, SNOW LEVELS WILL GRADUALLY DROP TO PASS LEVEL (3KFT
TO 4KFT) ACROSS THE OR MOUNTAIN ZONES AS THE SHORTWAVE FORCES A
COOLER AIRMASS INTO THE PACNW TONIGHT. THIS WILL RESULT IN SNOW
AMOUNTS OF 0.5" TO 3 INCHES ACROSS THE PASSES, WA CASCADES, AND
SOUTHERN BLUES, WITH AMOUNTS CLOSER TO 3 TO 5 INCHES IN THE
INTERIOR NORTHERN BLUES, ELKHORN CREST, OR CASCADE CREST, AND
THE EAGLE CAPS (CONFIDENCE 65-85%).
OTHER THAN PRECIP, BREEZY WEST TO SOUTHWEST WINDS (15 TO 25MPH
WITH GUSTS 25 TO 40 MPH) WILL DEVELOP ACROSS FORECAST AREA AS
AN AREA OF SURFACE LOW PRESSURE DEVELOPS OVER THE UPPER PORTIONS
OF THE COLUMBIA BASIN.
DRIER CONDITIONS WILL SETTLE INTO THE REGION BY WEDNESDAY
AFTERNOON AS UPPER LEVEL RIDGING BUILDS ACROSS THE NORTHEAST
PACIFIC, RAISING 500MB HEIGHTS ACROSS THE PACNW.
WEDNESDAY NIGHT THROUGH FRIDAY: THERE IS GOOD AGREEMENT AMONGST
ENSEMBLE AND DETERMINISTIC GUIDANCE THAT THE PACNW WILL BE UNDER
A NORTHWEST FLOW ALOFT AS RIDGING CONTINUES TO BUILD OVER THE
NORTHEAST PACIFIC. THIS WILL RESULT IN MOSTLY DRY CONDITIONS
ACROSS THE FORECAST AREA THROUGH FRIDAY NIGHT. THAT SAID,
UPSLOPE FORCING ALONG THE WA CASCADE CREST WILL BE STRONG ENOUGH
TO WRING OUT ANY LINGERING MOISTURE IN THE FLOW ALOFT AND
PRODUCE LIGHT SNOW FLURRIES, WITH DAILY SNOW AMOUNTS ANYWHERE
FROM A TRACE TO ONE INCH AT SNOQUALMIE AND WHITE PASSES.
AFTERNOON BREEZY WINDS (15 TO 25MPH WITH GUSTS 25 TO 40 MPH)
WILL CONTINUE TO BE A DAILY OCCURRENCE ACROSS MAINLY THE WA
CASCADE EAST SLOPES/CREST, AND THE COLUMBIA BASIN AND ADJACENT
VALLEYS/FOOTHILLS. THERE IS STRONG AGREEMENT AMONGST ENSEMBLE
AND DETERMINISTIC MODEL GUIDANCE THAT A SURFACE LOW WILL LINGER
ACROSS NORTHERN WA THROUGH FRIDAY, WITH HIGH PRESSURE DEVELOPING
WEST OF THE CASCADES AND OVER THE SAWTOOTH MOUNTAINS IN ID.
SATURDAY THROUGH MONDAY: THROUGH EARLY NEXT WEEK, ENSEMBLE
CLUSTER GUIDANCE INDICATES THAT A CLOSED LOW UNDERCUTTING THE
UPPER RIDGE IN THE NORTHEAST PACIFIC WILL SLOWLY PUSH EAST
TOWARDS NORTHERN CA AND SOUTHERN OR. AS IT APPROACHES, THE
SOUTHERN PORTIONS OF THE FORECAST AREA WILL SEE LIGHT RAIN/SNOW
DEVELOP AS EARLY AS SATURDAY AFTERNOON, WITH LIGHT PRECIP
PERSISTING INTO EARLY NEXT WEEK(CONFIDENCE 50-70%). OTHERWISE,
DRY CONDITIONS WILL PREVAIL ACROSS THE REMAINDER OF THE FORECAST
AREA. LAWHORN/82
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
FOR THE REMAINDER OF
THIS MORNING, A MIX OF FLIGHT CATEGORIES WILL BE PREVAILING BETWEEN
MVFR AND LIFR FOR KDLS, KPDT, KYKM, KALW, AND KPSC. KRDM/KBDN ARE
CURRENTLY VFR, BUT ARE EXPECTED TO DETERIORATE TO MVFR FOR THE REST
OF TODAY. WITH PERIODS OF RAIN, MIST AND LOW TO MID CIGS, MOST SITES
MAY FALL UNDER MVFR CONDITIONS OR LOWER THROUGH THE REMAINDER OF
TODAY. HOWEVER, KYKM COULD RETURN TO VFR AROUND 9Z TONIGHT. FOG WITH
LESS THAN A MILE MAY DEVELOP FOR KPDT AROUND 8Z TONIGHT (30-40%
CONFIDENCE). FEASTER/97
PRELIMINARY POINT TEMPS/POPS
PDT 34 47 30 54 / 80 10 0 0
ALW 35 48 33 53 / 80 30 0 0
PSC 33 52 33 55 / 50 0 0 0
YKM 27 49 28 52 / 40 0 0 0
HRI 34 51 30 55 / 60 0 0 0
ELN 26 42 29 46 / 40 10 10 10
RDM 31 46 21 52 / 60 10 0 0
LGD 36 46 25 51 / 90 40 0 0
GCD 37 44 23 49 / 80 40 0 0
DLS 34 48 32 53 / 60 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...82
AVIATION...97
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