655
FXUS66 KOTX 011156
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
356 AM PST Mon Dec 1 2025

.KEY MESSAGES...

- Light snow late Monday into Tuesday, especially in the
  Central Panhandle Mountains.

- Modifying temperatures and a transition of snow to rain late
  this week with breezy winds

- Moderate impacts from snow expected on the mountain passes
  late week into the weekend.

&&

.SYNOPSIS...
A weather system on late Monday into Tuesday will bring light
snow mainly to the Idaho Panhandle and extreme Eastern
Washington. Temperatures will modify and warm above normal late
this week. Unsettled late this week as well with snow
transitioning to rain in the lowlands.

&&

.DISCUSSION...
Tonight: A short wave ridge off the coast will move over the
region tonight for dry conditions. An abundance of stratus today
over Southeast Washington into the south ID Panhandle has been
slowly moving north this afternoon as boundary layer winds shift
out of the south. Continued expansion of stratus northward is
expected through tonight, which should help keep fog coverage
mostly patchy in coverage.

Monday through Tuesday: A wave topping the ridge moves over the
region bringing an increased threat of mainly snow Monday
afternoon into Tuesday as colder temperatures support low snow
levels. Precipitable water values briefly increase to around
150-175% of normal, which combined with isentropic ascent into
the ID Panhandle and eastern third of Washington leads to the
development of light snow. The highest amounts are expected in
the Central Panhandle Mountains and the Camas Prairie where
upslope flow is maximized. The 12z ECMWF ensembles have trended
upward with precipitation totals and snow amounts. Here are the
latest NBM chances for 1" of snow or more: Colville: 20%,
Spokane 15%, Pullman 20%, Sandpoint 60%, Kellogg 60%. Given that
the latest NBM doesn`t have the 12z ECMWF ensembles
incorporated, it`s possible that these numbers increase with the
next run.

Tuesday Night and Wednesday: As this system pushes east, a short
wave ridge moves in for another drier period. A moist boundary
layer combined with the ridge is a good setup for more fog and
stratus over the region.

Thursday through Sunday: An active pattern becomes established
by the weekend as an arctic air mass slides south into Central
British Columbia, while a strong pacific jet also takes aim at
the region. The jet is likely to keep cold air well north of our
area, with 85% of the ensembles favoring an active jet over the
region with an influx of moisture and milder air. The increase
in temperatures and snow levels will result in mainly a valley
rain and mountain snow situation although some valleys may begin
as snow with the initial warm front late Thursday or Friday
before snow levels rise. The strong jet will also bring breezy
to windy conditions on Friday. There is some model spread in the
details that far out regarding exactly how windy. The NBM
currently has a 30% chance of wind gusts exceeding 40 MPH at
Wenatchee and Pullman, and a 15% chance for Spokane. Wenatchee
has a 20% of gusts exceeding 50 MPH as well. Similar
probabilities are forecast for Saturday and Sunday. JW

&&

.AVIATION...
12Z TAFs: Persistent MVFR stratus over NE WA and northern Idaho
Panhandle will slowly erode from the south/southeast but
confidence is low if this clearing will reach KGEG-KCOE as just
when HREF probabilities reach this corridor, A band of light
snow is moving in and the trend reverses. The first band of snow
today is expected to be very light with low confidence for
accumulations on terminals. The low stratus is also drifting
toward KMWH-KEAT this morning but is tough to say for sure where
it is located as high clouds are masking its appearance via
satellite. Confidence is moderate for KPUW and KLWS to remain
VFR through 20z. After 20z, the incoming band of -SN results in
decreased confidence levels how long cigs will become. There
will be a brief break then additional bands of showers will
track north to south through the region with the most persistent
snow focused over the Idaho Panhandle between KCOE and KLWS.
Little to no precipitation is expected in Central WA which has a
higher probability for breaks in the clouds and patchy shallow
fog development. Breaks between the snow showers in NE WA will
also result in a chaotic, extremely low confident forecast for
fog or low stratus at times.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is a
30-40% chance that MVFR cigs lift out of KGEG/KSFF/KCOE this
morning. There is moderate confidence in stratus moving through
KMWH 12-15Z. Biggest uncertainties lie with impacts from the
very light snow with the initial band of precipitation and how
cigs react between different waves of showers thereafter.
Highest probabilities for cigs to return to MVFR or lower for
KGEG/KSFF/KCOE is closer to 10z and later on Tuesday. /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  28  34  24  36  27 /  30  50  30   0   0  10
Coeur d`Alene  33  29  35  27  38  29 /  30  70  50   0   0  20
Pullman        36  29  35  28  38  25 /  30  60  80  10   0  10
Lewiston       38  33  41  33  42  30 /  20  60  70  10   0  10
Colville       32  22  37  19  37  22 /  30  50  10   0  10  10
Sandpoint      32  27  34  25  35  27 /  40  80  50  10  10  40
Kellogg        33  32  35  29  38  30 /  40  80  80  10  10  40
Moses Lake     36  27  38  24  38  26 /  20  20  10   0   0   0
Wenatchee      35  32  39  30  41  28 /  20  20  10   0   0   0
Omak           35  27  39  27  39  25 /  30  20   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...None.
ID...Winter Weather Advisory from 1 PM this afternoon to 11 AM PST
     Tuesday for Central Panhandle Mountains.

&&

$$