429
FXUS66 KPDT 071143
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
343 AM PST Fri Nov 7 2025

.UPDATED AVIATION.

.AVIATION...12Z TAFs...Radar shows precip currently leaving the
PDT/PSC/ALW area, with a few lingering light showers. We will dry
out as we head into the night, paving way for dry conditions for
the rest of the period. VIS and CIG levels will not be an issue
and keep things in VFR for all sites for the remainder of the
period. The major highlight will be the winds as PDT/RDM/ALW/PSC
are experiencing some breezy 15-25 knots gusts. These will
persist for much of the period through the early afternoon hours
Friday, before dropping to 5-15 knots. Rest of the sites will see
light and variable conditions through the TAF period.


&&

.PREV DISCUSSION... /issued 328 AM PST Fri Nov 7 2025/

.DISCUSSION...

Key Messages:

1. Lingering winds and mountain precipitation.

2. Dry, but below normal temperatures through weekend.

3. Mountain showers Monday, Widespread coverage returns Thursday.

Current radar and infrared satellite imagery shows a line of
precipitation passing through the Blue Mountains and spotty
showers over the Cascades under mostly cloudy skies. This is in
response to the passing of an upper level trough and associated
cold front, which has also brought breezy winds across the area.
These winds are beginning to subside and will continue to decrease
through the day as the system departs to the east and a high
pressure ridge builds in its wake. Rain chances (15-35%) will
become confined along the Cascades and higher elevations of the
Northern Blue Mountains through the early afternoon, with dry
conditions expected after 6 PM. Snow levels will hover between
3500-4500 feet north-to-south as an additional inch of snowfall is
expected at elevations of 5000 feet and above (70-90% chance via
NBM). Rain amounts of less than 0.10" are likely over higher
elevations of our mountain zones, with the Basin staying dry
following the overnight line of showers - which dropped around
0.05" of rain across lower elevations. The incoming ridge that is
following closely behind the departing trough will allow isobars
to stay rather tight between these two features, which will keep
winds elevated through the afternoon. Sustained west winds of
10-20 mph with gusts around 30 mph are expected across the
Columbia Basin, Blue Mountain foothills, and Kittitas Valley
(50-70% chance via NBM). The incoming high pressure will also lead
to clearing skies through the late morning and early afternoon
through the Columbia Basin.

The high pressure will finally provide some relief from the
consistent wet pattern that the area has been experiencing over
the last week. Skies will also stay mostly clear to partly cloudy,
which will allow for significant radiational cooling to occur
overnight into the early morning hours. Saturday morning
temperatures are expected to dip into the upper 20s to low 30s.
most populated centers in across the Columbia Basin will be waking
up to freezing temperatures morning (50-70% chance via NBM), with
a couple degree improvement expected on Sunday. Today`s high
temperatures will break into the mid-to upper 50s across the
Columbia Basin, and will drop 5-8 degrees Saturday and stay in the
low 50s through Sunday. These high and low temperature values are
2-4 degrees below normal for this time of year. Temperatures
across Central Oregon will be much more mild as the ridge of high
pressure builds in from the south. High temperatures are likely to
break into the low 60s Saturday and into the low to mid-60s on
Sunday as lows hover in the low to mid-30s both mornings.

The upper level ridge begins to suppress and flatten on Sunday in
response to an upper level shortwave that will weaken as it passes
through the Pacific Northwest on Monday. Ensembles are in good
agreement in showers staying confined to the Cascade and northern
Blue Mountains Monday evening through Tuesday morning. Snow levels
of 6500-7500 feet are likely, keeping precipitation mostly liquid
except for higher terrain. Rain amounts of up to 0.20" are
possible along the Washington Cascade crest (45-55% chance via
NBM), with a tight gradient that drops to a trace near Cle Elum.
Ensembles are also in fairly good agreement with the next, more
substantial system late Wednesday into Thursday. This is expected
to bring more widespread showers across the region as snow levels
dip into the 3500-4500 foot range on Thursday. There are some
discrepancies regarding the incoming upper level trough`s
strength and timing, with the majority of members split between a
tighter, more deep trough versus a broad and shallow one. The more
broad scenario would be able to tap and transfer additional
moisture east of the Cascades, which is currently the slightly
more favorable scenario. At this time, lower elevations of the
Basin and Blue Mountain foothills will receive 0.02-0.10" of rain,
with 0.15-0.30" expected over the Cascade and Blue Mountains
(45-65% chance via NBM). 75


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  56  32  53  33 /  10   0   0   0
ALW  55  36  53  37 /  10   0   0   0
PSC  59  31  53  32 /   0   0   0   0
YKM  56  30  52  32 /   0   0   0   0
HRI  58  33  53  33 /   0   0   0   0
ELN  50  28  48  29 /  10   0   0   0
RDM  53  25  58  29 /  10   0   0   0
LGD  52  28  54  35 /  40   0   0   0
GCD  52  29  59  34 /  30   0   0   0
DLS  57  38  55  37 /  20  10   0   0

&&

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

$$

SHORT TERM...75
LONG TERM....75
AVIATION...95