430
FXUS66 KPDT 112139
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
139 PM PST SUN JAN 11 2026
DISCUSSION
BREEZY TO WINDY CONDITIONS WILL PERSIST THROUGH THE BLUE MOUNTAIN
FOOTHILLS THROUGH MONDAY. ESPECIALLY WINDY CONDITIONS WILL
PERSIST ACROSS THE I-84 CORRIDOR THROUGH THE GRANDE RONDE VALLEY.
HERE, THE PRESSURE GRADIENT BETWEEN MEH AND BKE REMAINS STRONG (6
MB OR HIGHER). THE GRADIENT STRENGTHENS OVERNIGHT BASED ON THE NAM
AND SREF. THE WIND ADVISORY FOR THIS AREA HAS BEEN EXTENDED
ANOTHER 24 HOURS UNTIL NOON MONDAY COINCIDING WITH A 90TH
PERCENTILE OF THE NBM MEMBERS WIND FORECAST.
THE WA CASCADES ARE BRUSHING A GRADIENT OF AN ATMOSPHERIC RIVER
IMPINGING ON THE PAC NW/BC REGION, RESULTING IN SHOWERS LINGERING
TODAY , TONIGHT FOLLOWED BY RAPIDLY DECREASING CONFIDENCE THROUGH
MONDAY AS THE ENTIRE AREA THEN BEGINS A DRY PERIOD WITH HIGH
CERTAINTY (90%) BY MONDAY NIGHT.
FOR THE REST OF THE WEEK, A STAGNANT PATTERN IS APPARENTLY
SETTING UP AS MODELS INTENSIFY THE 500 MB RIDGE EXPANDING ACROSS
THE INTERIOR NW INTO THE PACIFIC NW AROUND TUESDAY AND LINGERING
THROUGH THE WEEK. A RESULT WILL BE THAT MEAN MIXING HEIGHTS (BY
THE NBM) LIMITED TO UNDER 1500 FT DURING THE PEAK HEATING DURING
PEAK HEATING EACH DAY, WHILE TRANSPORT WINDS ALSO REMAIN LIMITED
TO 10 MPH OR LESS.
THE STAGNANT PATTERN TYPICALLY LEADS OF OVERNIGHT VALLEY DENSE
FOG, AND OR FREEZING FOG, AND AREAS OF LOWLAND FOG WAS
ADDED/MAINTAINED IN THE WEATHER GRIDS FOR THE TUESDAY THROUGH
FRIDAY PERIOD AS THE STRONG INVERSIONS SET UP OVERNIGHTS,
INCLUDING THE YAKIMA VALLEY AND LOWER COLUMBIA BASIN.
THE 8 TO 14 DAY OUTLOOK INDICATES A TREND TOWARD NEAR NORMAL
PRECIPITATION AND A 40 TO 50% CONFIDENCE FOR ABOVE NORMAL
TEMPERATURES.
PREV DISCUSSION
/ISSUED 917 AM PST SUN JAN 11 2026/
AVIATION...18Z TAFS...VFR CONDITIONS EXPECTED. LIGHT WINDS MAINLY
OUT OF THE S/SW WILL PREVAIL, ALONG WITH BKN-OVC MID-LEVEL CIGS.
74
PRELIMINARY POINT TEMPS/POPS
PDT 35 57 34 52 / 0 0 0 0
ALW 38 56 39 53 / 10 10 0 0
PSC 34 56 35 49 / 10 10 0 0
YKM 34 51 36 52 / 10 10 0 0
HRI 33 55 32 49 / 0 0 0 0
ELN 33 48 36 49 / 30 20 0 0
RDM 28 56 27 58 / 0 0 0 0
LGD 32 47 32 51 / 0 0 0 0
GCD 30 52 32 56 / 0 0 0 0
DLS 37 52 35 51 / 10 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
OR...WIND ADVISORY UNTIL NOON PST MONDAY FOR ORZ049.
WA...NONE.
DISCUSSION...71
AVIATION...74
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