528
FXUS66 KOTX 202235
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
235 PM PST Thu Nov 20 2025

.KEY MESSAGES...

- Minimal weather impacts outside morning fog through Sunday
  morning.

- Snow returns to the mountain passes Sunday evening and night.

- Light valley snow and cooler temperatures Tuesday night into
  Wednesday. Moderate snow on the mountain passes.

&&

.SYNOPSIS...
The weather will remain quiet through Sunday with near to warmer
than normal temperatures. An unsettled weather pattern returns
Sunday and continues into next week. Snow will impact the
mountain passes beginning Sunday evening and again Tuesday night
into Wednesday. This midweek system will bring the potential for
light snow in the lowlands as well.

&&

.DISCUSSION...
Tonight-Saturday: A quiet and relatively mild end to the work week
and start of the weekend. The weak front responsible for the
heavier cloud cover over portions of the INW on Thursday will
continue to weaken with midlevel clouds eroding through the
evening. The main weather impact tonight will be low clouds and
fog developing. This will be accompanied by temperatures near or
slightly below freezing. Be cautious of slick conditions
heading out for the Friday morning commute. As of 2PM, we are
already seeing a bank of low clouds over the Palouse beginning
to drift northward as boundary layer winds shift to the south.
This is expected to expand into Spokane-Cd`A this evening. With
the established stratus deck, the highest probabilities for fog
will be west and north of these lower clouds across the central
and western Basin as well as the valleys of northern WA and
north ID where radiational cooling will be maximized.

Zonal flow develops for Friday and Saturday with a 120+ kt jet
nosing into southern BC. Thick clouds will pass through
northern WA and north Idaho at times with a 20-30% chance for
light precipitation over the mountains. Much of the INW will
remain dry and mild for late November with temperatures in the
mid to upper 40s. Winds will be light with speeds of 10 mph or
less.

Sunday-Monday: Changes arrive on Sunday as trough with cooler air
drops out of the Gulf of Alaska and through the Northwest. The
trough will usher a cold front through the region with periods
of light rain. Snow levels will remain high such that impacts on
the mountain passes will be minimal (mainly wet) through Sunday
afternoon. Colder air will flood into the region Sunday evening
and overnight delivering gusty winds and transition from rain
to snow in the mountains and even some of the higher benches of
the Camas Prairie, Palouse, and Central Panhandle Mountains
overnight. Wind gusts of 20-30 mph will be in place Sunday
night. Highest probabilities for gusts of 30-35 mph will extend
between Walla Walla and Pullman.

Motorists heading over the Cascades and Lookout Pass after sunset
Sunday evening should be prepared for a transition toward
wintery weather. Snow showers will continue over the mountains
on Monday morning with light additional accumulations before
showers taper off Monday afternoon. The remainder of the Inland
NW will be cool and largely dry with breezy westerly winds in
place. Temperatures on Monday will have a bit more of a bite
with highs only in the lower 40s and accompanying wind chills in
the 30s due to steady winds of 6-12 mph.

Tuesday-Thursday: Tuesday will be a favorable travel day across the
Northwest with high pressure briefly building into the region
and dry conditions outside a few light mountain showers. It will
be a cold start with temperatures in the lower 20s. The weather
pattern takes a turn Tuesday night heading into Wednesday with
the next plume of rich moisture becoming aimed to the Northwest.
There is increasing confidence for a period of light snow to
impact the region Wednesday as the leading edge of this rich
moisture overruns the cooler air left behind Sunday night`s cold
front. At this time, the initial band of light snow looks to be
a quick hitter across the lowlands with a strong jet arriving
on its heels over the Northern Pacific. Nonetheless, this could
be the first dusting to inch of snow for many communities across
the INW. Travel over the mountain passes could be a different
story with moderate to heavy snow in the Cascades and light to
moderate amounts over Lookout Pass. Those planning to travel
over the Cascade passes Tuesday night into Wednesday are urged
to monitor the forecast closely and plan accordingly. Stevens
and Washington Passes have a 40/30% chance for 8" or more
respectively with a bulk of this falling Tuesday night through
Wednesday.

The forecast becomes uncertain Wednesday night into Thursday due
to many variations with the orientation of an incoming the
plume of subtropical moisture. If this rich axis of moisture
(which contains precipitable water values on the order of
200-220% of normal) can remain aimed with a slight west to
southwest orientation into the Cascades and INW, the air mass
will undoubtedly become warmer and result in rising snow levels.
This could mean a transition to rain for most lowlands and even
the passes. The NBM has nearly a 50/50 split for p-type (rain
or snow) at Stevens Pass by Wednesday afternoon. This pass is
higher elevation than Snoqualmie which could experience a
transition to rain sooner. This may be good news for those
holiday travelers needing to travel last minute Wednesday PM and
night. In a different scenario, the axis of subtropical
moisture noses inland further south closer to the WA/OR border.
In this outcome, the cold air persists over the WA and ID passes
and results in potential for all snow for Stevens, Washington,
and Lookout Passes. This would also keep snow over the northern
mountains and mountain valleys although, there is likely to be a
break in the precipitation for a period of time Wednesday night
into Thursday morning before lifting back in Thursday. All
things considered, there is low confidence in the details
centered around Thursday. /sb

&&

.AVIATION...
18Z TAFs: A weak front limping through the region is bringing
increasing moisture at low to mid levels. Ceilings are currently
near 6-7k ft AGL but will be lowering between 4-6 kft AGL and
down to between 2-4 kft AGL with MVFR conditions developing at
KPUW/KGEG/KSFF/KCOE Thursday afternoon into the evening. Cigs
will continue to lower toward IFR conditions at KGEG overnight.
Clearing over Central WA will increase probabilities for low
stratus or fog development around KMWH/KEAT after 08z.


.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Confidence is moderate that MVFR ceilings will develop with the
stratus for KPUW/KGEG/KSFF/KCOE. Model guidance is in good
agreement with a 50-70% chance for ceilings to lower below 3 kft
AGL at these terminals by Thursday evening. Confidence increases
that ceilings lower further Thursday night with a 60% chance
that IFR conditions develop at KGEG after 08Z. At KMWH, there is
a 70-80% chance for ceilings to lower below 1000 ft with only a
10-20% chance at KEAT. /sb

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

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        32  44  30  46  34  47 /   0  10   0   0  10  30
Coeur d`Alene  34  44  33  47  35  47 /   0  10  10  10  20  40
Pullman        31  46  31  48  34  49 /   0  10   0   0  10  30
Lewiston       35  49  34  51  37  54 /   0   0   0   0   0  20
Colville       26  42  28  45  30  44 /   0  20  10  10  30  40
Sandpoint      31  42  32  45  34  44 /  20  30  20  20  40  60
Kellogg        36  45  35  49  37  49 /  10  20  10  10  20  50
Moses Lake     29  42  28  43  30  45 /   0   0   0   0   0  20
Wenatchee      31  44  33  45  36  47 /   0  10   0   0  10  30
Omak           31  43  34  44  36  45 /   0  10   0   0  10  20

&&

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

&&

$$