311
FXUS66 KPDT 241746
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
946 AM PST Mon Nov 24 2025

Updated Aviation Discussion

.AVIATION...18Z TAFs...VFR conditions to prevail through the
period. There are low chances (20-30%) of MVFR vsby developing at
site PSC around or after 12Z. Otherwise, cloud cover will increase
late overnight at all sites, but remain AOA 5kft AGL through the
end of the TAF period. Breezy winds 12-17kts with gusts up to
25kts will continue at sites DLS/PDT through 1Z, becoming less
than 12kts through the remainder of the period. All other sites
will see light winds, 12kts or less, through the period.
Lawhorn/82

&&

.PREV DISCUSSION... /issued 321 AM PST Mon Nov 24 2025/

.DISCUSSION...A cold front is currently passing through the area
that is now situated along eastern Oregon, close to the OR/ID
border. A couple showers in the eastern portion of the Basin will
linger for the next couple of hours with some wintry mix along the
Eastern Mountains continuing to fall through the early morning
hours. Overnight lows will drop below or at freezing for many
portions of the area (60-80 percent chance), with slightly warmer
temperatures across portions where the rain/wintry mix will
linger longer. Winds will continue to be breezy with gusts up to
20 to 25 mph in many parts of the region. Expecting winds to
decrease heading into the late morning hours into the early
afternoon. Will see an area of high pressure introduce some
temporary drying conditions Monday through Tuesday morning. This will
increase chances of freezing fogs in some of the valleys going
into the early morning hours of Tuesday, although confidence
remains medium (30-50 percent chance) with partly cloudy to mostly
cloudy conditions keeping confidence high.

Unsettled weather will resume Tuesday afternoon when high
pressure situated in eastern Idaho/western Wyoming along with a
low located in northern California will bring a southern shift in
the wind, increasing moisture transportation to fuel our next
weather event. At the same time, a stationary front will be
situated just offshore of the PacNW, extending a shortwave trough
in the region, bringing enough instability with a southern wind to
initiate low valley rain with mountain snow and/or wintry mix
Tuesday through Thanksgiving. This will make holiday travel
tricky, especially through Snoqualmie Pass and other parts of the
WA Cascades where the NBM is suggesting 4 to 7 inches of
accumulated snowfall (40 to 60 percent chance), although it`s
worthwhile to note this is a slight downtrend than what we saw
compared to yesterday afternoon. Regardless, extra caution is
needed if traveling this week through the WA cascades. No
highlights are expected as of yet, but will keep additional
monitoring if an advisory is warranted.

Friday will continue to see a pattern supporting low valley rain
with mountain snow and/or wintry mix showers. Precipitation will
kick-off again on Friday with a shortwave passing through the
region to bring heavier snow/rain showers, although NBM shows a
slight downtrend in accumulation with guidance showing only an
additional half inch accumulation the day after Thanksgiving.
Guidance suggests the Basin may get its first snow event this
weekend, but confidence is a bit split with only 44% of clusters
suggesting this scenario. The question becomes how deep/strong the
incoming trough this weekend will be, while the remaining members
shows a much weaker trough with a drier solution overall.
Regardless, accumulation does not look impressive with most of the
lower Basin possibly seeing only up to a tenth an inch of
accumulation, if any accumulates. By nature of being Day 5 and
being in a transitional season along with unsettled weather brings
the model to disagreement by nature. As we get closer to this
weekend, we`ll have a much more clear picture if the trend favors
the first snow day for many to be as early as this weekend.
Regardless which way the forecast falls, this should be a reminder
to prepare for winter weather as we begin meteorological winter
December 1st.


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  48  27  44  34 /  20   0  20  60
ALW  47  32  44  36 /  30   0  20  70
PSC  52  27  43  33 /  10   0  10  60
YKM  49  27  41  30 /   0   0  30  60
HRI  51  27  43  34 /  10   0  20  60
ELN  46  24  39  28 /   0   0  40  70
RDM  46  21  48  31 /   0   0  10  30
LGD  44  23  43  33 /  50   0  10  60
GCD  44  24  46  33 /  40   0  10  50
DLS  51  33  43  37 /  10  10  50  70

&&

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

$$

DISCUSSION...95
AVIATION...82