841
FXUS66 KOTX 121836
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1136 AM PDT Sun Oct 12 2025

.KEY MESSAGES...

- Moderate to heavy snow for the mountains Sunday into Monday
  morning.

- Gusty north to northeast winds on Monday. Cold wind chills in
  the teens to single digits in the mountains.

- Below normal temperatures Sunday into early next week with
  highs in the 50s. Low temperatures dropping into the 20s and
  30s by Tuesday.

&&

.UPDATE...
The intensity of the precipition has resulted in snow punching a
bit further down with snow levels as low as 4000-4500 feet in
the Central Panhandle Mountains this morning. Light snow was
observed over Lookout Pass. Snow is expected to melt through the
afternoon as road temperatures warm, but we should see snow
begin to stick again in the evening before tapering off a little
after midnight. A Winter Weather Advisory has been issued above
4000 feet for the Central Panhandle Mountains with slick travel
expected over Lookout Pass this evening and impacts to anyone
out in the backcountry at higher elevations. /SVH

&&

.SYNOPSIS...
Heavy snow with winter conditions is expected in the Cascades
and northern mountains above 3000 feet Sunday into Monday. Windy
conditions are expected over much of the region on Monday. Dry
weather with fall like temperatures are expected Tuesday through
Thursday.

&&

.DISCUSSION...

...EARLY SEASON WINTER STORM TO BRING MODERATE TO HEAVY SNOW TO
THE CASCADES, NORTHERN MOUNTAINS OF EASTERN WASHINGTON AND
NORTH IDAHO...

Sunday through Monday: An intensifying low pressure system will
drop south over the region today bring much needed widespread
precipitation to the Inland NW. The upper trough drops south out
of Canada and intensifies over the region as a surface low
spins up along the WA/OR coast in the left exit region of an
upper level jet. The surface low will help draw in low level
cold air from the north as winds turn northeast. Models have
trended toward lower snow levels by Monday morning. Although as
the low drops south and the northeast winds increase,
precipitation intensity will be decreasing over the northern
valleys as the winds draw in colder, and drier air. Yet, models
show a period of rain changing to snow over the northern valleys
and possibly briefly for the West Plains and Waterville
Plateau. With the warmer ground temperatures of mid-October, it
will be tough for snow to stick in the valleys, but several
inches will accumulate in the mountains. Mission Ridge will
especially be favored as the north-northeast winds upslope into
that area with 12-18 inches forecast.

Below are the are the probabilities for snowfall thresholds of
at least 2", 4", and 8" at our mountain passes

Mountain Pass    Chance of 2+"    Chance of 4+"     Chance of 8+"
Washington       95%              90%               85%
Sherman         100%              90%               50%
Lookout          80%              45%                5%
Stevens          90%              80%               35%
Blewett          90%              60%               20%
Loup Loup        90%              70%               15%

Regarding winds, the pressure gradient over the region on
Monday over the region strengthens between a 1030mb surface high
over southern Alberta, and a 1005mb surface low along the
Oregon coast. This will bring gusty northeast winds especially
in the open area of the Columbia Basin, and channeled north-
south drainages such as the Purcell Trench in North Idaho
(Sandpoint and Coeur d`Alene areas), and the Okanogan Valley.
The NBM continues to advertise gusts of 30-40 MPH in these
areas.

Monday Night through Thursday: A quieter pattern returns as the
low drops south over California and an upper ridge builds off
the coast provides a dry north to northwest flow over the Inland
NW. It will feel like fall as low temperatures drop into the
20s and 30s for most of the region, and daytime highs in the mid
50s to low 60s.

Friday and Saturday: Ensembles are in better agreement of a
weaker trough passing through the region. With the trough and
mid level westerly flow the Cascade crest and ID Panhandle have
a chance of showers while most of Central and Eastern Washington
is expected to be rain shadowed. Snow levels with this bout of
light precipitation range from 5000-6000 feet. JW

&&

.AVIATION...
18Z TAFS: Low pressure drops south along the Washington
coastline tonight. A clash of moisture from the south into
colder Canadian air from the north will result in widespread
precipitation across the Inland Northwest today into tonight.
Widespread MVFR conditions is expected through the day tonight.
Airports across the region will mainly see rain with this low
pressure system. Cold air with increasing north to northeast
winds will make an impact tonight. This may result in a little
bit of snow mixing in with rain overnight including at KCOE and
KGEG. Northerly winds will be gusty through north Idaho, the
Okanogan Valley, and over the Columbia Basin overnight into
Monday with gusts of 20-30 kts common, and as strong as 35 kts
at KOMK/KSZT KCOE by the morning hours on Monday. IFR conditions
with lowering ceilings may occur overnight fore the boundary
layer dries out into Monday morning.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in CIGS lowering to at least MVFR for GEG/SFF/COE/PUW and
moderate confidence for MVFR conditions at LWS/MWH/EAT. Low
confidence for snow to mix in as temperatures cool late tonight
into Monday morning. Best chances would be at KGEG/KCOE/KEAT
with a probability of less than 10% chance. /SVH

-----------------------
Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane
airports, please refer to the Aviation Dashboard on our webpage:
https:/weather.gov/otx/avndashboard

&&

.Preliminary Point Temps/PoPs...
Spokane        45  35  51  31  56  33 /  90  90  10   0   0  10
Coeur d`Alene  45  34  52  31  58  35 / 100  90  10   0  10  10
Pullman        46  39  55  30  56  32 /  90  80  20   0  10  10
Lewiston       51  44  62  39  60  40 /  90  70  20  10  10  10
Colville       47  32  52  19  57  22 / 100 100  20   0   0  10
Sandpoint      43  32  48  26  54  31 / 100 100  20   0   0  10
Kellogg        40  32  47  32  54  36 / 100 100  30  10  10  20
Moses Lake     55  40  55  35  59  32 /  70  90  60   0   0  10
Wenatchee      53  37  52  37  58  40 /  70  90  70   0   0  10
Omak           50  37  54  33  61  33 /  90  90  40   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory from 5 PM this afternoon to 5 AM PDT
     Monday for Northeast Mountains-Okanogan Highlands.
     Winter Weather Advisory until 11 AM PDT Monday for Central
     Chelan County-Western Chelan County-Western Okanogan
     County.
ID...Winter Storm Warning until 5 AM PDT Monday for Northern
     Panhandle.
     Winter Weather Advisory until 5 AM PDT Monday for Central
     Panhandle Mountains.

&&

$$