803
FXUS66 KPDT 191812
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1012 AM PST Wed Nov 19 2025

.DISCUSSION...Skies are clearing across much of the forecast area
early this morning as a ridge of high pressure accompanied by
cold and dry air slides into the PacNW. Low clouds are lingering
(and even building) across some of our elevated valleys in central
and eastern Oregon, but otherwise much of the Basin and mountain
foothills are seeing clear skies. Could see patchy fog develop
across some of our usual fog-prone areas along river valleys, but
given the lack of a temperature inversion present across obs,
thinking is that this morning will just be cold, with much of the
forecast area seeing below-freezing temps. As of this discussion`s
writing, the Freeze Warning in the Columbia River Gorge is
flirting with verification with temps in the mid to upper 30s, and
as long as low stratus does not form via light easterly winds,
the last of our freeze-eligible zones should finally fall.

Looking ahead, Wednesday will be dry before our forecast area is
clipped by the next system - a low diving to our south and east
before settling over southern California. The trajectory of this
system is not favorable for widespread precip, so as of now, the
forecast for late Wednesday into Thursday looks to be that of
light mountain snow generally less than an inch above primarily
4500-5000 ft, with perhaps a stray shower impacting the Basin
(15-30%) via wraparound moisture from the low as it digs to our
south. But with most of this system`s moisture landing to our
west, impacts are overall anticipated to be minimal.

We enter another relatively benign pattern Friday through Sunday
as ridging, slightly dirty in nature, prevails over the region.
Guidance favors persistent shower chances across primarily the WA
Cascades over the weekend, but QPF is once again minuscule.
Ensemble guidance starts to diverge Monday onward, but some
members do depict an upper-level wave moving down from the ridge
upon us early Monday morning, which would provide for the next-
best chance for area-wide precip. But beyond that, forecast
confidence weakens (30-40%) as ensemble solutions diverge in light
of a relatively progressive synoptic pattern. 74

AVIATION...18Z TAFs...The main driver of sub-VFR (mainly IFR)
conditions across TAF sites today will be low stratus that is
blanketing central and north-central Oregon. Based on satellite
imagery and web cameras, stratus appears to be roughly 500-800
feet thick over BDN/RDM, with wispier stratus sloshing around the
eastern Columbia River Gorge at DLS. Anticipating it will take
several hours to clear at RDM/BDN with earlier clearing at DLS.
Elsewhere, mostly clear skies are present with fog/stratus
remaining confined to the lower elevations along the Columbia,
Snake, and Walla Walla rivers.

An incoming weather system will bring a return of BKN/OVC skies
tonight into Thursday, with the best chances of precipitation at
BDN/RDM. While precipitation type is expected to be predominantly
rain at BDN/RDM, some light snow may mix in as well (30 percent
confidence). Light rain is forecast at DLS. Farther north and
east, precipitation chances are lower (10-30 percent) at other TAF
sites.

Mostly light winds (10 kts or less) are forecast through the
period (80 percent confidence).

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  48  32  47  32 /   0  20  30   0
ALW  48  35  46  36 /   0  20  40  10
PSC  49  32  49  30 /   0  10  10   0
YKM  48  32  50  29 /   0  20  10   0
HRI  48  34  48  31 /   0  20  20   0
ELN  45  29  48  29 /   0  20  10  10
RDM  50  28  47  23 /   0  60  20   0
LGD  50  34  50  30 /   0  20  50  10
GCD  53  35  49  29 /   0  30  40   0
DLS  50  39  52  36 /   0  60  40  10

&&

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

$$

DISCUSSION...74
AVIATION...86