579
FXUS66 KOTX 041021
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
221 AM PST Thu Dec 4 2025

.KEY MESSAGES...

- Wintry mix Thursday into Friday may result in a slick
  commutes.

- Warming 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.

- Increased potential for rock slides next week with a mild and
  wet weather pattern.

&&

.SYNOPSIS...
The weather will trend much more unsettled Thursday through the
weekend. Temperatures look to be cold enough tonight into
Friday to support a lowland wintry mix. By Friday, temperatures
will modify and warm above normal with unsettled weather
continuing through the weekend and into next week.

&&

.DISCUSSION...

     MIXED VALLEY PRECIPITATION AND MOUNTAIN SNOW THROUGH THIS WEEKEND
TO BRING THE POTENTIAL FOR TRAVEL IMPACTS...

Today through Saturday Night: An active jet stream will be aimed
at the region bringing several rounds of precipitation.

The first short wave arrives today as warm advection results in
isentropic ascent which is maximized over the ID Panhandle,
particularly the Central Panhandle Mountains with the assistance
of upslope flow as well. Precipitable water increases to 175-200%
of normal further increasing confidence of an increase in
precipitation. The warm advection will help erode the cold air
from southwest to northeast, reaching the Wenatchee and Moses Lake
areas and the Waterville Plateau this morning. Temperatures have
been holding steady in Wenatchee and Moses Lake around 33-35F, but
gain a little elevation onto the Waterville Plateau and
temperatures are in the upper 20s. Temperatures are also running
colder for the Upper Columbia Basin. With the warming aloft and
surface temperatures near freezing, the HREF continues to
advertise areas of light freezing rain this morning. Yet, with
POP`s only chance and amounts expected to be very light confidence
in significant impacts for an advisory is low. As precipitation
reaches NE Washington into the ID Panhandle, mainly snow is
expected, although snow levels will gradually be rising to
2000-2500 feet this afternoon into the evening.

A relative lull in the precipitation occurs tonight as the first
wave before the next round moves in Friday morning. The latest
HREF shows low level cold air to be scrubbed out for mainly a
valley rain/mountain snow event except the northern valleys where
snow levels will start off around 2000 feet. This wave will carry
stronger isentropic lift as warm advection continues with even the
northern valleys changing to rain Friday afternoon. There will
also be stronger jet support as a robust 160 kt zonal jet takes
aim at the region. 850mb winds increase to 50 kts, jet being in
the warm sector mixing potential does not look sufficient for
these higher gusts to mix down into the valleys. Yet there are a
few exceptions. One being around the Wenatchee area and Waterville
Plateau where a stable layer above mountain tops may allow
stronger gusts to mix down. Another is the Alpowa Summit area near
the Blue Mountains, with HRRR currently advertising gusts around
50 MPH.

With snow levels on the increase this should limit snow impacts
for Stevens Pass as steady light snow today changes to rain
tonight. After the strong jet Friday sags south Friday Night snow
levels fall back down to near 4000 feet Saturday leading to a
better potential for snow to impact the pass. For Lookout Pass
precipitation is expected to fall as mainly snow through the
evening with a Winter Weather Advisory in effect for the first
round of snow today into tonight, followed by a Winter Storm Watch
above 3000 feet for Friday.

Sunday through Wednesday: A mild and wet pattern continues with
rounds of more precipitation. These next rounds look to contain
greater moisture content as an atmospheric river takes aim at the
region Monday into Tuesday. After that model differ if it
continues into Wednesday or lifts north or south of the region.
Snow levels rise to 5000 to 7000 feet which means even most of the
mountain passes see a change to rain. So concerns will shift to
mud and rock slides in steep terrain due to rain and snow melt,
and rises on rivers and small streams. At this time no flooding is
forecast. JW

&&

.AVIATION...
06Z TAFs: Widespread IFR and MVFR stratus will continue tonight
over Central and Northeast Washington and the ID Panhandle. Another
round of precipitation moves in between 12z-16z Thursday,
bringing rain and snow to the region. The warm advection and
precipitation will saturate the boundary layer, with IFR and
MVFR conditions expanding to include SE Washington and the
Lewiston area. Pockets of light freezing rain are also possible
in the Columbia Basin Thursday morning. With KEAT/KMWH holding
fairly steady near 34-36F and latest HREF guidance supporting
rain as the most likely precip type did not mention FZRA for
these sites.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence of widespread IFR and MVFR conditions across the
region into Thursday. Exception is KEAT where increasing
downslope boundary layer winds may help break up the stratus
Thursday afternoon. JW

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

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        34  32  39  35  44  36 /  80  70  90  60  40  30
Coeur d`Alene  35  32  39  35  43  35 /  90  70 100  80  70  60
Pullman        36  33  44  38  44  38 / 100  90 100  90  70  60
Lewiston       39  37  49  41  51  41 /  90  90 100  90  50  50
Colville       36  32  36  33  41  32 /  70  40  90  60  50  30
Sandpoint      35  32  36  33  39  35 /  80  70 100  90  80  70
Kellogg        35  33  40  35  40  37 / 100  90 100 100  90  80
Moses Lake     36  35  43  36  50  36 /  70  50  70  20  10  10
Wenatchee      39  35  47  38  49  37 /  50  50  80  50  30  30
Omak           35  33  38  34  42  33 /  50  40  90  40  20  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...None.
ID...Winter Weather Advisory from 7 AM this morning to 4 AM PST
     Friday for Central Panhandle Mountains.
     Winter Storm Watch from late tonight through Saturday
     afternoon for Central Panhandle Mountains.

&&

$$