281
FXUS66 KPDT 110002
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
502 PM PDT Fri Oct 10 2025

Updated Aviation Discussion

.DISCUSSION...

A broken band of rain and rain showers was pivoting across the
lee of the Cascades this afternoon in response to a deep upper low
just off the Oregon coast. These rains have produced generally
under a tenth of an inch across the eastern sections of Klickitat,
Wasco, Jefferson and Deschutes counties, and higher rain amounts
over the eastern slopes (in the 0.10-0,20 range by mesonet obs
in the last 6 hours). HREF 1hr precipitation trends show this
rain band disintegrating by 3-6z (or early to mid evening).
Overall colder temperatures are expected Saturday morning, with
the warmest lows being found across the Columbia Basin, in the
mid 40s.

A cold front will be driven across the region Saturday and
overnight, bringing a wind impacts to the Columbia Gorge area with
strong westerly winds overnight. Although short in duration for
the higher impact winds, the median NBM gusts output at DLS is
around 40 mph with potential to around 50 mph on the standard
deviation plot. This continues to support wind advisory headlines
across the Simcoe Highlands and the Eastern Columbia River Gorge
of Oregon for Saturday night. Windy conditions will also extend
southeast across the Lower Columbia Basin of Oregon, however the
stronger sustained winds in the Gorge area are related to the
current advisory area and we will not be expanding the advisory
in areal coverage at this time.

Snow will be on the uptick though the weekend. WPC Snow ratios
were reduced slightly from the NBM numbers, and snow ratios of
10:1-12:1 are limited to the highest mountain elevations. Greatest
snowfall will be along the Upper Slopes of the Eastern Washington
Cascades, Lower Slopes of the Eastern Washington Cascades Crest
and the East Slopes of the Oregon Cascades. Four to six inches are
also possible (NBM) across the Wallowas above about 5,000 ft.
Winter Driving conditions may still be encountered across the more
elevated reaches of the Kittitas valley and along I-90 Sunday into
early Monday.

Boundary layer cold air advection and precipitation cooled air
will contribute to relegating high temperatures to the 40s and 50s
on Sunday and Monday. Even colder high temperatures in the 30s
will certainly be possible in areas above 4-5 kft where meaningful
snowfall would happen. Temperatures begin to recover Monday into
Tuesday as more widespread 60s are likely across the Columbia
Basin, Grande Ronde Valley and John Day Basin. Russell/71


.AVIATION...00Z TAFS...Mostly VFR conditions to prevail through
the period. Rain shower impacts will continue through 03Z at sites
DLS/RDM/BDN, with dry conditions persisting afterwards. A gust
front originating from showers along the Cascade east slopes
briefly brought strong winds and reduced vsby to sites PDT/ALW,
with vsby clearing shortly afterwards at site PDT, with MVFR vsby
continuing through the next 2 hours at site ALW. Strong winds
associated with the gust front will continue at these sites
through the next several hours. Otherwise, winds will generally be
12-20kts with gusts to around 25kts at sites PDT/PSC into this
evening, becoming light overnight. Breezy winds 12-20kts with
gusts 20-30kts will redevelop at sites DLS/PDT/ALW/PSC tomorrow
after 15Z. Otherwise, winds will remain light at all other sites
through the period. Lawhorn/82

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  43  61  43  56 /  50  60  70  60
ALW  48  62  45  55 /  50  50  80  70
PSC  44  65  44  58 /  30  30  40  50
YKM  41  62  39  57 /  40  40  20  60
HRI  44  63  44  58 /  50  40  50  40
ELN  38  58  37  52 /  50  40  40  60
RDM  31  55  32  52 /  60  40  50  40
LGD  41  57  39  51 /  50  60  90  70
GCD  38  56  37  52 /  40  50  70  30
DLS  46  63  47  60 /  70  70  60  80

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 11 PM Saturday to 5 AM PDT Sunday for ORZ041.

WA...Wind Advisory from 11 PM Saturday to 5 AM PDT Sunday for WAZ024-
     521.

&&

$$

DISCUSSION...71
AVIATION...82