Pendleton, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

766
FXUS66 KPDT 142235
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
235 PM PST Wed Jan 14 2026

.DISCUSSION...

Key Messages:

1. Stagnant conditions persist through week.
   *Dense Fog Advisory Active*
   *Air Stagnation Advisory Active*

2. Dry conditions and cooling trend into next week.

Current radar and visible satellite imagery shows dry conditions
and clear skies, with the exception of lingering fog and low
stratus across the Yakima and Kittitas Valleys. This has resulting
in the issuance of a Dense Fog Advisory over these valleys earlier
in the day, with the Kittitas Valley`s advisory extending until
noon Thursday due to the continuing visibilities as low as one
quarter of a mile. Fog is likely to return tonight into Thursday
morning across the Yakima Valley (50-60% chance), and even
potentially across the Simcoe Highlands, Columbia Gorge, Lower
Columbia Basin, and the northern Blue Mountain foothills (15-25%
chance) as a strong upper level ridge and surface high pressure
resides across the Pacific Northwest, allowing inversions to
be present. This is evident as current temperatures at lower
elevations of the Columbia Basin are in the low to mid-40s,
whereas higher elevations across the Northern Blue Mountains and
the Cascades are in the mid-to upper 50s. This pooling of cold
air at lower elevations will inhibit vertical mixing, keeping air
and particulates close to the ground surface. This has warranted
the issuance of an Air Stagnation Advisory across the Lower
Columbia Basin, Columbia Gorge, Blue Mountain foothills, Central
and North Central Oregon, and the Kittitas/Yakima Valleys until 10
AM Friday. This may lead to further degradation of air quality,
with current values in the moderate category with Air Quality
Index (AQI) values between 50-80 across the aforementioned areas.

The upper level ridge will shift just offshore late today and
elongate up the British Columbia and Southern Alaska coast through
the remainder of the week, enhancing north-northwest flow aloft
across the Pacific Northwest and advecting a cooler airmass into
the area. This will lead to temperatures cooling through the
weekend, bottoming-out Sunday and Monday with high temperatures in
the mid-to upper 30s across the Columbia Basin and Blue Mountain
foothills with lows dropping in the low to mid-20s. Ensembles
suggest the upper level ridge will break down Monday into Tuesday
as an embedded shortwave rides over and suppresses the ridge. This
will bring the next chance (15-25%) for precipitation Tuesday
evening into Wednesday. There are considerable uncertainty
regarding timing and rain amounts related to overall strength of
the embedded shortwave trough and how quickly the ridge breaks
down, but 56% of ensemble members suggest precipitation arriving
along the Cascades in the early morning hours on Wednesday. All
ensemble members highlight mountain precipitation across the
Cascade and Blue Mountains Wednesday, but only 19% of members show
widespread precipitation reaching lower elevations of the
Columbia Basin. Snow levels are forecast to be between 3500-4500
feet Wednesday, which means any precipitation will fall as snow
across our mountainous terrain. However, the amounts are expected
to be rather low as 88% of ensemble members keep 24 hour snow
totals through Thursday afternoon below 1 inch. 75



&&

.AVIATION...00Z TAFs...LIFR conditions continue for YKM at the
beginning of the period. Expecting the low level cloud deck to
persist through 02Z but will keep monitoring for potential
longevity beyond. Otherwise expecting some more fog to drop to a
half mile in the DLS in the early morning hours lasting until around
18Z, with ALW in a TEMPO group around the same time for half mile
fog. Otherwise, continuous VFR conditions are expected with small
chances for areas to develop temporary fog in IFR or worse (5-15
percent chance) going through the overnight hours.


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  30  43  26  39 /   0   0   0   0
ALW  32  42  29  39 /   0   0   0   0
PSC  29  43  29  41 /   0   0   0   0
YKM  31  47  28  44 /   0   0   0   0
HRI  30  42  28  40 /   0   0   0   0
ELN  31  43  26  40 /   0   0   0   0
RDM  27  50  21  42 /   0   0   0   0
LGD  32  50  28  46 /   0   0   0   0
GCD  35  54  30  52 /   0   0   0   0
DLS  33  45  31  44 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Air Stagnation Advisory until 10 AM PST Friday for ORZ041-044-
     507-508-510-511.

WA...Air Stagnation Advisory until 10 AM PST Friday for WAZ024-
     026>029-521.

     Dense Fog Advisory until 2 PM PST this afternoon for WAZ026-027.

&&

$$

DISCUSSION...75
AVIATION...95