538
FXUS66 KOTX 270318
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
718 PM PST Wed Nov 26 2025

.KEY MESSAGES...

- Snow impacting travel in the East Slopes of Cascades and
  along Hwy 20 tonight through Thanksgiving then Lookout Pass
  Thursday night into Friday morning.

- Colder temperatures over weekend into next week with
  occasional chances for snow showers.

&&

.UPDATE...
A dense fog advisory is in effect through 3 AM Thursday for the
Spokane Area. The main are of concern will be in Airway Heights.
This includes travel along Highway 2 between Davenport and
Airway Heights and along I-90 between Tyler and Airway Heights.
Expect visibility down to 1/4 mile or less at times. An incoming
warm front tonight should provide enough mixing in the boundary
layer for fog to thin and visibility to improve overnight. /SVH

&&

.SYNOPSIS...
Precipitation moves in Wednesday night through Thanksgiving. A
mix of rain and snow is expected for the northern mountain
valleys and additional light snow over mountain passes resulting
in minor impacts to travel. A dry, cold air push will bring
colder temperatures for the weekend.

&&

.DISCUSSION...
Tonight through Friday:  A potent low pressure system is tracking
across the Eastern Pacific toward the WA Coast and is expected
to make landfall Thursday afternoon. The system will deliver
additional rounds of precipitation to the region coming in the
form of rain and snow. Where snow falls will be a bit more
complex vs the Tuesday-Wednesday morning system. A weak midlevel
warm front will lift south to north over the region overnight
bringing the first round of light precipitation. Many lowlands
across the northern mountains and East Slopes were socked in low
clouds today. This kept temperatures varying from 32-35F vs the
upper 30s and lower 40s. Models suggest midlevel temperatures
for areas along and north of Hwy 20 and within the upper river
valleys of the East Slopes including Leavenworth, Winthrop,
Republic, Ione, and Bonners Ferry are expected to remain near 0C
or colder. As such, the forecast has been adjusted to lower
snow levels and maintain snow as the p-type though accumulations
with the first wave of moisture will likely be low with snow
falling with temperatures near or just above freezing and weak
ascent through the dendritic layer. Heavier precipitation will
arrive through the day on Thursday as the low nears the coast
and pushes a cold occluding front inland. Forcing ahead and
along the occluded front will ramp up, especially through the
dendritic layer while easterly winds dam cooler air into the E
Slopes. This combination will work against rising snow levels
blasting northward north of the International border and it
conceivable that upper reaches of the Methow Valley, Republic
Area, Upper Pend Oreille River Valley, and Porthill/Bonners
Ferry area experience multiple hours of snow from late tonight
into Thursday night. Intensities will vary over time which will
limit accum due to temperatures wavering from 32-35F; would not
rule out 1-3 inches for these lowlands with local amounts in
excess of 5 inches on the higher benches and peaks including
Washington, Loup Loup, and Sherman Passes and this is reflected
in the latest forecast. If you are traveling over these passes,
please be prepared for snowy travel. The warmer air will have an
easier time working into the Cascade passes for Hwy 2 and I-90
where temperatures are already near 33F and not expected to
cool. Snow is in the forecast for tonight but a transition to
rain is expected with light slushy, accumulations. Lookout Pass
is also near 33F with wet snow expected with the warm front but
minor impacts are expected as snow levels will have ample time
to rise before the heavier precipitation arrives Thursday
afternoon. For the remainder of the lowlands, weather impacts
will come in the form of patchy dense fog and light to moderate
rains.

The remnants of the low pressure system will track through the Inland
NW Thursday night into Friday morning and depart to the southeast.
Gusty northerly winds will be drawn into the departing system
with speeds magnified down the Okanogan Valley where gusts will
be on the order of 20-30 mph. These northerly winds will draw
cooler air back into the region with snow levels falling over
the lower Idaho Panhandle and Blue Mountains and periods of
moderate snow in the mountains. Greatest impacts to Lookout Pass
will come Thursday night into Friday morning where 4-6 inches
of snow is expected to fall. The higher benches of the Camas
Prairie will also see a transition to wet snow with potential
for an inch. The remainder of the region will dry out with clear
skies. The increased winds will also deliver increased
probabilities to scour out low clouds and fog.

Saturday-Sunday: A ridge of high pressure will amplify over the
E Pacific placing the INW under northwest flow aloft. There is
good agreement of another shortwave dropping down from the
northwest on Saturday, generally quick hitter, fashion. This
will bring a renewed threat for snow showers to the Cascades and
anywhere from a trace to two inches. The flow pattern would
also favor the rising terrain of the Camas Prairie and Blue
Mountains for a quick tenth of QPF and light snow accumulations
above 2500 feet. Breezy north to northeast winds will continue
to draw cooler continental air in from the north and east.

Monday-Thursday: There is good agreement amongst the ensembles
for the upper-level ridge to waver around over the Eastern
Pacific and at times, flop over into the coastal Pac NW. This
will result in near to below normal temperatures for the Inland
NW through the period with occasional chances for weaker waves
to drop in from the northwest bringing rain and snow showers.
When these waves are not present, there are increased odds for
dry and chilly conditions and periods of afternoon sunshine. /sb

&&

.AVIATION...
00Z TAFs: The very moist boundary layer continues to bring low
ceilings to KGEG/KSFF/KCOE, with fog still being observed at
KGEG. High-res models showed a 10% chance of visibilities
remaining at 1/4 mile or less for KGEG. TAFs for KGEG/KSFF/KCOE
see a brief in visibilities around 0900 as rain moves through
the area, but reflect a brief increase in visibilities around
0900. Around 15Z, visibilities and ceilings become low again.
For KPUW/KLWS, rain looks to begin around 03Z and last through
09Z with a warm front moving through. Rain will return by 18Z.
Due to an easterly wind moving through, ceilings remain around
VFR to MVFR through around 16Z. KMWH/KEAT have improved to MVFR,
but look to drop back down by 03Z, when rain moves through the
area. These locations will experience rain from around 06Z
through the end of the TAF period and into the next TAF period.
Around 06Z, ceilings will drop down back into the IFR range
through 20Z. Main factors impacting confidence in the forecast
is the timing of the rain and the ceilings decreasing,
particularly for KGEG/KSFF/KCOE.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High-res models
show a 10% chance of almost no improvement for ceilings in the
GEG/SFF/COE area. The timing of the rain ending will impact
ceilings decreasing. Moderate confidence in lower ceilings as
most models show at least VFR conditions or less for all TAF
sites. Biggest uncertainty will be impacts to visibilities and
ceilings and how quickly they deteriorate with the timing of the
rain, especially with the KGEG areas.

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

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        37  35  41  35  42  25 /  20  40  90  90  40   0
Coeur d`Alene  38  35  41  35  40  24 /  40  50  90 100  70  10
Pullman        40  36  44  36  40  27 /  50  50  60 100  90  20
Lewiston       45  39  49  40  46  32 /  40  40  30  90  80  10
Colville       37  27  39  28  42  21 /   0  40 100  90  20   0
Sandpoint      38  31  39  31  39  21 /  50  50 100 100  80  10
Kellogg        38  37  44  36  39  23 /  70  60  90 100  90  20
Moses Lake     40  37  43  35  46  28 /  10  40  90  70  20   0
Wenatchee      38  36  41  37  45  32 /  10  70  90  80  10   0
Omak           37  33  39  32  43  27 /   0  50  90  60   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Dense Fog Advisory until 3 AM PST Thursday for Spokane Area.
ID...None.

&&

$$