901
FXUS66 KPDT 230552
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
952 PM PST Sat Nov 22 2025


.UPDATED AVIATION...06Z TAFs...While most sites are in VFR
through this evening, low CIGs and fog/mist will be the main
concern for KYKM/KPSC thus dropping them to LIFR overnight into
Sunday morning. However, fog may return Sunday evening for KYKM.
Other than that, light rain may develop starting around Sunday
afternoon over KDLS/KPDT/KALW/KPSC when the frontal passage
arrives (30% confidence). Feaster/97

&&


.PREV DISCUSSION... /issued 229 PM PST Sat Nov 22 2025/

.DISCUSSION...Low stratus continues to blanket much of the lower
Columbia Basin, Yakima and Walla Walla, and Wallowa valleys.
Elsewhere, skies are mostly clear to partly cloudy as we await the
arrival of a Pacific cold front Sunday. Have included a mention of
patchy fog in the forecast overnight into Sunday morning for the
aforementioned areas as confidence is high (80 percent) that the
inversion will persist.

Snow levels will drop Sunday afternoon through Sunday night as the
cold front sweeps across the region. No winter highlights are in
effect, but do have medium-high confidence (60-80 percent) in
one-half inch to two inches of snow for mountain passes in the
Cascades and northern Blue Mountains.

Breezy westerly winds of 10-20 mph accompanied by gusts of 20-35
mph are forecast late Sunday afternoon through Monday.

Tuesday afternoon through Thursday, uncertainty in forecast
details is still present as ensemble guidance struggles to resolve
features of a progressive weather pattern, including the
magnitude and axis of moisture transport into the Pacific
Northwest, focusing mechanisms for precipitation (fronts, surface
lows, etc.), and any wintry precipitation. Will note the NBM
suggests a low probability (5-20 percent) of 1 inch or greater
snowfall for the 48-hr period ending 4 PM PST Thursday for the
Yakima, Kittitas, and Grande Ronde valleys. In the eastern half of
the Columbia Basin and farther south into central Oregon,
guidance is more confident in a warmer air mass, resulting in very
low probabilities of measurable snowfall (less than 5 percent).
While probabilities are still quite low (up to 10 percent), the
synoptic pattern does support some potential for measurable
freezing rain Tuesday night and Wednesday in sheltered valleys
along the east side of the Washington Cascades as warm air
overrides colder air at the surface.

&&


.PRELIMINARY POINT TEMPS/POPS...
PDT  35  53  32  47 /   0  20  70  10
ALW  39  52  35  46 /   0  40  80  20
PSC  34  54  32  50 /   0  20  40   0
YKM  35  53  27  49 /  10  30  20   0
HRI  34  53  33  49 /   0  20  50   0
ELN  34  49  29  44 /  20  50  30  10
RDM  27  54  24  45 /   0  20  40   0
LGD  34  53  30  43 /   0  20  90  20
GCD  31  55  29  44 /   0  10  60  10
DLS  40  52  37  50 /  10  60  50  20

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

SHORT TERM...86
LONG TERM....86
AVIATION...97