Sun Valley

000
FXUS66 KOTX 261150
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
450 AM PDT Mon Oct 26 2026

.KEY MESSAGES...

- Active weather pattern with chances for precipitation
  increasing on Monday. Precipitation chances continue 
  throughout the work week.

- Snow levels lowering to between 3,000 and 4,500 feet with snow
  in the mountains by Tuesday night and continuing through 
  Thursday. Winter travel over mountain passes in the Cascades 
  to Sherman Pass in north-central WA will be possible.

&&

.SYNOPSIS...
The weather pattern turns more active this week with a pair of 
low pressure systems impacting the region. The first weather 
system moves across on Monday and is expected to bring light 
precipitation, especially across southeast WA and into the ID 
Panhandle. A second, colder weather system for Tuesday night 
through Thursday night will drop snow levels to as low as 3000 
feet over the Cascades and north- central WA and down to around 
4500 feet in the ID Panhandle. Valley rain and mountain snow is 
expected with the potential for travel impacts over mountain 
passes.

&&

.DISCUSSION...
Monday through Tuesday: A vertically stacked low off the
Washington coast will weaken and slide southeast today (Monday).
As it does so increased lift ahead of the low combined with mid
level instability will result in a band of rain showers passing
through the region with snow levels around 5000 to 6000 feet. As
the low exits Monday Night residual moisture and upslope flow into
the Cascades, Northeast Washington, and the Idaho Panhandle will
keep showers persisting. With the weakening nature of the low and
quick movement through the area precipitation amounts are 
expected to be light, mainly between .05 to .15 inches. Exception
is around the Blue Mountains into the Central Panhandle Mountains
where stronger lift as well as surface based instability with 
CAPE of 200-400 J/KG has the potential to produce locally heavier 
downpours with rain amounts of a quarter inch. A few thunderstorms
can not be ruled out but confidence remains too low to include in
the forecast.

Wednesday through Thursday: An upper ridge amplifies along 150W 
in the Eastern Pacific forcing a trough to settle into the region,
with a stronger closed low dropping south along the WA coast on 
Wednesday and remaining in place Thursday. There is good ensemble 
agreement leading to high confidence of a cooler and showery 
pattern as snow levels fall Wednesday to 3000-4500 feet. This 
will allow for snow in the mountains including the passes, 
especially in the Cascades. Increasing instability with 500mb 
temperatures dropping to near -30C combined with upslope flow 
into the Cascade crest will be favorable for several inches of 
snow at Stevens Pass and Washington Pass. Below are the NBM 
chances for various snow thresholds being reached for the mountain
passes from 5 PM Tuesday to 5 PM Thursday:

Mountain Pass   2+ inches   4+ inches   6+ inches   8+ inches
Stevens Pass    100%        75%         40%         5%
Washington Pass 100%        60%         10%         2%
Sherman Pass     60%        10%          1%         0%
Lookout Pass     50%        10%          0%         0% 

Snow is likely to cause winter driving conditions at times in the
mountains and drivers should be prepared for winter travel. With
the influence of the low and showers high temperatures will drop
into the mid 40s to low 50s, with overnight lows mainly in the
30s.

Friday through Sunday: The low remains off the coast Friday and
Saturday but gradually weakens resulting in a drying trend.
Although impulses rotating into the area will keep a chance for
rain and mountain snow showers persisting. Snow levels overnight
fall as low as 2000 feet in the northern valleys such that some
wet snow could mix in at the lower elevations as well but little
to no accumulations are expected at this time. On Sunday the low
digs further south leading to drier conditions across the Inland
NW but with continued cool temperatures. JW

&&

.AVIATION...
12Z TAFS: A band of precipitation associated with a low 
pressure system will remain nearly stationary through 15z over 
the Cascades. TAF sites will remain dry during this time. As 
the low pressure system moves eastward through the day, bands 
of showers will expand across the region with areas of MVFR 
conditions developing in the afternoon over Northeast Washington
and North Idaho. 

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for VFR conditions at all TAF sites through 18z Monday. As rain
spreads across Eastern Washington and North Idaho, NBM 
probabilities indicate a 30-50 percent chance of MVFR conditions
at KGEG/KSFF/KCOE/KPUW between 20z-01z. These chances increase 
to 50-70 percent between 02z and 12z.

-----------------------

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:/www.weather.gov/otx/avndashboard

&&

.Preliminary Point Temps/PoPs...
Spokane        53  39  52  38  48  34 /  90  70  40  60  90  70 
Coeur d'Alene  55  39  49  38  45  34 /  80  90  80  90 100  80 
Pullman        51  38  50  39  48  35 /  90  70  60  60  90  40 
Lewiston       54  43  55  43  53  38 /  90  50  50  40  70  50 
Colville       57  37  51  37  47  34 /  70  80  60  70  90  50 
Sandpoint      54  37  45  38  42  34 /  40  90 100 100 100  90 
Kellogg        56  37  45  37  42  33 /  70  90 100 100 100  80 
Moses Lake     55  38  58  38  53  34 /  20  10   0  20  30  10 
Wenatchee      55  41  56  39  51  36 /  40  10   0  40  30  40 
Omak           55  40  55  37  50  35 /  70  70  10  40  60  40 

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...None.
ID...None.

&&

$$