171
FXUS66 KPDT 131746
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
946 AM PST Thu Nov 13 2025

.UPDATED AVIATION.

.AVIATION...18Z TAFs...A mixed bag of sites at VFR to LIFR
conditions across the seven terminals. Low stratus continues to
dominate over ALW and PSC, although PSC shows an OVC deck that
will soon lift over the next few hours, along with visibility
clearing up as some of the heavier showers move out of the area.
Precipitation will continue to be off an on with the greatest
chances occurring right now, while confidence continues to go
down through the period, with mostly TEMPO groups put in through
the period for precipitation. We`ll be mostly VFR after 20Z, but
low confidence still remains for lower decks and obscure
visibility as we head into the late evening to early morning for
temporary sub- VFR conditions through the sites (5-15% chance),
although the greatest chances seem to be the sites outside of
Central OR (BDN/RDM specifically). Winds will continue to be light
to breezy, with Central OR sites (BDN/RDM) being the strongest
with gusts up to 25 mph lasting through the late afternoon hours
today.


&&

.PREV DISCUSSION... /issued 423 AM PST Thu Nov 13 2025/

.DISCUSSION...The forecast area finds itself caught between a
cutoff low to our south and an upper-level trough to our north
this morning, which will result in some moderately breezy
downslope winds and a round of light precipitation. Low ceilings
and even dense fog continue to persist for much of the Columbia
Basin and the Walla Walla Valley, respectively, as persistent cold
pooling from an otherwise stable synoptic pattern has allowed
these conditions to persist. The expectation is that we`ll see
some relief today, however, as even though the wind forecast
across guidance is subdued because of an overly stable environment
in the Basin, warm air advection brought about by the low to our
south and its subsequent downslope winds should provide enough of
a drying effect to at least partially lift ceilings, especially
along the foothills. So even though central Oregon and the
Foothills of the Blues will see gusts in the 20-30 mph range today
while the lower elevations continue to see light winds,
conditions are ripe for at least some scouring out of this pesky
fog and stratus.

With moisture advection lacking, however, precipitation impacts
are expected to be minimal with this system. CAMs generally
depict broken shower activity over the forecast area during much
of the day, with more persistent bands over primarily the
Cascades. But with snow levels well above 7000 ft, ptype will be
rain across all of our area`s mountain passes. Light shower
activity may persist across the mountains through Friday (30-40%
confidence), however the bulk of the moisture with this oncoming
system is expected to occur today, before transitory ridging
slides in late Friday into Saturday.

Widespread PoPs return on Sunday as global models generally depict
a weak shortwave clipping the forecast area to the east, but
again with only minimal precip impacts, concentrated mainly across
the eastern mountains where snow levels are generally expected to
be above the 6000-7000 ft range. Colder air then looks to intrude
on Monday as a more northwesterly trough moves in, but this
system looks to be relatively moisture-starved based on ensemble
QPF guidance. Better, more widespread PoPs materialize late
Tuesday into Wednesday as ensembles generally depict a more
organized trough moving into the PacNW. 74


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  62  45  61  42 /  50  70  30  10
ALW  60  48  60  46 /  60  80  50  20
PSC  54  43  62  43 /  50  60  10  10
YKM  54  39  58  39 /  90  60  10  20
HRI  57  44  61  43 /  50  70  20  10
ELN  51  36  52  38 /  90  60  20  40
RDM  66  36  58  32 /  50  40  10   0
LGD  64  43  60  38 /  50  80  50  20
GCD  66  42  59  37 /  50  70  20   0
DLS  57  46  60  46 /  90  80  40  30

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...Dense Fog Advisory until 10 AM PST this morning for WAZ028-029.

&&

$$

SHORT TERM...74
LONG TERM....74
AVIATION...95