496
FXUS66 KPDT 030644 CCA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1044 PM PST Tue Dec 2 2025

.UPDATED AVIATION...06Z TAFs...Most sites (KDLS/KPDT/KYKM/KALW/KPSC)
will have low clouds arriving through the day Wednesday, though
patchy fog lingers over KALW/KPSC overnight with KYKM joining in
around 12Z (MVFR conditions or below). The fog will also drop VSBYs
to 1/2SM or lower, bringing KALW/KYKM/KPSC to LIFR conditions. While
the fog may dissipate late Wednesday morning (18Z/19Z) as VSBYs
improve, low cloud decks will continue for these sites
(KDLS/KYKM/KALW/KPSC) thus keeping them between MVFR and IFR. KPDT
may see patchy fog/mist overnight (30-40% confidence), but mid to
high clouds will start returning early Wednesday morning. KRDM/KBDN
will be in VFR through this TAF period. Winds will be less than
10kts. Feaster/97

&&


.PREV DISCUSSION... /issued 252 PM PST Tue Dec 2 2025/

.DISCUSSION...

Precipitation chances will be dwindling rapidly this afternoon as
high surface pressure increases across the region. Locally dense
fog was forming along the foothills of the northern Blues This
Afternoon, which may be the precursor to more fog development
Tonight. With the recent rains and some snow areas, and a cool
moist boundary layer, the risk for some freezing fog exists
overnight as temperatures plummet into the upper 20s, with the
only area escaping freezing temperatures being the Columbia River
Gorge. Other than this diurnally recurring local/areas of freezing
fog risk, little sensible weather (Little to no risk) is expected
for about 36 hours or through at least early Thursday. Despite
the high pressure, starting out colder early Wednesday morning
will promote even cooler high temperatures in some spots Wednesday
than we are seeing This Afternoon, but overall it will be a
similar day are far as highs go. The warming trend does not begin
until Thursday evening when rains and breezy conditions redevelop.
High mountain snows are possible as well Thursday night as the
NBM prints 3 along the Wallowa Eagle Caps. EPS ensemble mean
500 mb heights show a sharp drop in heights around Friday, turning
the westerly flow not only cooler but more zonal. Efficient rains
return to the Cascades and northern Blues, as begins a wet period
for the end of the week and beyond. NBM is producing gusts in the
high 40 knots range across the Simcoe Highlands Friday Night.
This looks like a possibility of a high end advisory episode from
late Saturday afternoon through early morning Saturday as model
LREF ensembles show nearly 70% chances of 40 mph gusts or higher
over the lower Columbia Basin of Washington and Simcoe Highlands
areas. However large uncertainty exists as the huge differences
are seen between the 25th and 75th percentile wind gusts, between
22 and 38 mph respectively. A significant bump in total
precipitation for the season is expected through the weekend, as
even the lower Columbia Basin is shown by the grand ensemble mean
to receive around one quarter inch of rain, and the higher
elevations of the eastern mountains have means of anywhere from 1
to 2 inches total precipitation. Russell/71

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  27  41  29  42 /   0   0  10  70
ALW  28  39  31  41 /  10  10  10  80
PSC  24  38  28  40 /   0   0  10  60
YKM  25  38  28  42 /   0  10  10  40
HRI  25  39  29  41 /   0   0  10  70
ELN  23  38  27  41 /   0  10  20  40
RDM  21  45  25  47 /   0   0  10  40
LGD  25  41  26  41 /  10   0  10  80
GCD  27  42  26  43 /  10   0   0  70
DLS  35  44  37  47 /   0  10  20  70

&&

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

$$

SHORT TERM...71
LONG TERM....71
AVIATION...97