735
FXUS66 KPDT 052308
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
308 PM PST Mon Jan 5 2026

.Key Messages...

- Freezing Fog Advisory for Kittitas Valley through 10 AM
  Tuesday.

- Winter Storm Warnings in effect from 4AM Tuesday through 4PM
  Thursday.

- Breezy to locally windy conditions Tuesday through Thursday.

.DISCUSSION...Given the NAM guidance showing visibility less
than one mile through 10AM PST Tuesday near Ellensburg, a
Freezing Fog Advisory has been issued for the Kittitas Valley for
that timeframe. Based on surface observations and webcams,
visibilities of less than one mile have been persisting through
majority of today along I-90 and I-82 near Ellensburg through Cle
Elum and may continue tonight as well. Otherwise, current
satellite and radar imagery show light returns across the
Foothills of the Northern Blue Mountains and Grande Ronde Valley
and mid to high clouds passing from central OR to the eastern
mountains.

Winter Storm Warnings will remain as our main concern for WA/OR
Cascades and Northern Blue Mountains early Tuesday morning into
Thursday afternoon. Multiple of weather systems will push across the
region, bringing total snow accumulations of 12 to 30 inches over
the Cascades and 7 to 10 inches at the Northern Blues (>70 percent
chance). In addition to that, we will see near blowing snow
conditions with expected gusty winds of 25 to 35 mph that could
impact visibilities and driving conditions through the work week.
The strongest winds and heaviest snow rates remain to be expected
for development Tuesday morning through the late evening hours
Tuesday as the frontal system approaches. Snow levels will gradually
drop to around 1.5 to 2 kft across the region Wednesday through
Thursday.

Breezy to locally windy conditions will develop starting Tuesday
into Thursday. We can expected the gusts to be about 25 to 35 mph
(40-60% chance) as these systems come through. The NBM raw guidance
favor a 20-30% probability for gusts at 40-45 mph. That said, not
confident enough to issue a wind advisory but winds may briefly
increase up to 45 mph (30% confidence).

&&

.AVIATION...00Z TAFS...VFR conditions are expected at all
TAF sites through the period.  The only exception is DLS, where some
low clouds/fog will begin to affect site late this evening overnight
and will bring lower conditions, likely even IFR conditions through
the morning hours.

Winds will generally be 10 kts or less, through afternoon Tuesday,
when BDN, RDM and ALW will see gusts to around 20 kts, and PDT could
gust in the 10 to 15 kt range.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  31  47  35  47 /   0  40  60  30
ALW  35  46  36  46 /   0  70  70  40
PSC  32  47  36  48 /   0  40  30  20
YKM  27  43  28  45 /   0  40  40  20
HRI  30  47  35  49 /   0  30  40  20
ELN  26  37  26  38 /   0  60  50  40
RDM  25  45  28  43 /   0  10  50  40
LGD  31  44  33  42 /  30  70  90  50
GCD  32  44  34  41 /  20  40  70  50
DLS  33  45  35  45 /   0  50  90  70

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Storm Warning from 4 AM Tuesday to 4 PM PST Thursday for
     ORZ502-509.

WA...Winter Storm Warning from 4 AM Tuesday to 4 PM PST Thursday for
     WAZ030-522-523.

     Freezing Fog Advisory until 10 AM PST Tuesday for WAZ026.

&&

$$

DISCUSSION...97
AVIATION...77