837
FXUS66 KOTX 132342
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
342 PM PST Sat Dec 13 2025

.KEY MESSAGES...

- Dry conditions and decreasing river levels through Sunday.

- Rain and High Mountain Snow Monday into Tuesday to bring
  additional river rises and mud and rock slide concerns to
  Cascades and Idaho Panhandle.

- High winds possible Tuesday Night into Wednesday. A 30-60%
  chance for widespread wind gusts of greater than 50 mph.

- High confidence for heavy mountain snow impacting the Cascades
  starting Wednesday morning. 70% chance of 3 feet or more of
  snow at Stevens Pass through Friday afternoon.

&&

.SYNOPSIS...
Drier weather is expected for this weekend with decreasing river
levels. Next week, another very active weather pattern moves
through the forecast area. Rain and high mountain snow Monday
into Tuesday will bring additional river rises with mud and rock
slide concerns in steep terrain of the Cascades and Idaho
Panhandle. Very windy conditions will then develop Tuesday Night
into Wednesday, along with the return of mountains snow. Heavy
mountain snow in the Cascades is expected mid to late week.

&&

.DISCUSSION...
...VERY ACTIVE WEATHER PATTERN NEXT WEEK WITH RENEWED FLOODING
CONCERNS FOR CASCADES AND NORTH ID PANHANDLE MONDAY INTO
TUESDAY, POSSIBLE HIGH WINDS TUESDAY NIGHT INTO WEDNESDAY, AND
HEAVY MOUNTAIN SNOW FOR THE CASCADES WEDNESDAY THROUGH FRIDAY...

Today through Sunday afternoon: A welcome break from cloud cover and
precipitation will last through tomorrow afternoon. Temperatures
remain much warmer than normal for this time of year, with highs
today and tomorrow expected in the high 40s/early 50s. These values
are 15-20 degrees higher than normal.

Sunday evening through Wednesday: By Sunday evening, another active
weather pattern makes its entrance as an atmospheric river moves
through the state of Washington. Another plume of warm moisture
comes through, raising PWATs across the forecast area from 90-100%
to 250-300% of normal. Alongside ensemble PWATs, Enhanced Forecast
Index values show anomalously high chances for temperatures (through
midweek), rainfall, and strong winds, which will be discussed below.
Temperatures for this first wave remain warmer than usual, and thus
snow levels remain high on Sunday and Monday, with snow being
confined to highest mountain elevations. By Tuesday, lower heights
will start to move in ahead of an upper level low, dropping snow
levels. On Wednesday, this upper level low will move through, and
mountain passes will begin seeing accumulating snow.

Rainfall: Because of antecedent conditions from the multiple
atmospheric rivers that moved through last week, hydrologic impacts
will continue to be seen. Multiple river forecast points in Chelan
County including Stehekin River and the Wenatchee River show a
forecasted increase in streamflows, either heading back into flood
stage or coming close to it. Rain totals at the mountain crest to
the upper river valleys (roughly 3000 feet and above) will total
nearly 3-4 inches. NBM probabilities show Leavenworth has a 40%
chance of seeing 3 or more inches of rain through early Wednesday
morning. In the Idaho Panhandle, rain amounts of 1.5-1.75 inches of
rain will fall, resulting in an uptick in streamflows for the Coeur
d`Alene river as well. Chances for upcoming hydrologic headlines
are increasing.

Snowfall: As the trough off coast moves into the state of Washington
on Wednesday, colder air will be advected into the area, lowering
snow levels and bringing accumulating snow to mountain passes along
the Cascades and Idaho Panhandle. With this second system, snowfall
will be heavy and continuous. NBM probabilities show Stevens Pass
has a 40% chance of seeing 2 feet of snow or more through early
Wednesday morning. Blewett and Lookout Passes have a 20-40% chance
of seeing 6 or more inches of snow during this time. Bottom line:
expect wintry driving conditions and prepare accordingly, as roads
may be slick.

High Winds: Impacts to driving will be further hindered Tuesday
night through Wednesday morning as strong westerly winds move
through. A surface low dropping into southern Alberta will deepen,
increasing the surface pressure gradient across the state. Right
now, deterministic wind forecasts show westerly 850 mb winds 50-
65kts Tuesday into Wednesday. With cold air advection making mixing
more likely, wind gusts at the surface will be strong. Areas that
will see the highest wind gusts include the Wenatchee, Waterville
Plateau, Spokane, basin, ID/WA Palouse, and Lewiston/Pullman areas.
NBM probabilities are currently showing a 40% chance and higher of
sustained wind speeds 25-30 mph. Many of these same areas have a 25-
35% chance of seeing wind gusts 55 mph or higher. A notable
exception is Lewiston/Pullman, with a 50% chance of 55+ mph wind
gusts. Wind headlines will almost certainly be needed if models
continue showing such strong winds Tuesday night into Wednesday
afternoon.

Thursday through Friday: Snow will continue in earnest at mountain
passes on Thursday, accumulating further. Blewett and Lookout Passes
have a 30-40% chance of seeing an additional foot of snow through
Friday afternoon. Stevens Pass will see considerably higher totals,
with a 77% chance of seeing 3 feet of snow or more through Friday
afternoon. Winter weather headlines will likely be needed mid to
late week. Bottom line, expect another impactful week of weather,
especially to mountain and foothill areas.

Saturday through Sunday: Clusters overwhelmingly show continued low
heights and another trough moving through the PNW next weekend and
into the beginning of next week. This will result in continued
chances for the active weather pattern to continue. The Climate
Prediction Center`s 8-14 Day Outlook also shows signals of a
continued active weather pattern, with increased chances for below
normal temperatures and above normal precipitation. /AS

&&

.AVIATION...
00Z TAFs: All TAF ceilings have improved to VFR and all but one
site are projected to stay that way through the TAF forecast
period. KMWH initially had a 40% chance of seeing MVFR per the
HREF, but those chances have increased, with a good chance for
LIFR conditions from around 10-18Z. No precipitation is expected
and winds are expected to be light.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in dry conditions and VFR conditions for TAF sites throughout
the forecast period. High confidence in no precipitation and
light winds. Moderate confidence in KMWH dropping to IFR or less
from 10-18Z. /AS

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

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        35  48  41  54  40  50 /   0  20  20 100  60  50
Coeur d`Alene  36  48  41  52  40  48 /   0  20  30 100  80  70
Pullman        36  50  41  50  41  51 /   0  10  10  90  80  60
Lewiston       39  55  43  56  46  56 /   0   0   0  70  60  40
Colville       32  44  35  49  33  46 /   0  20  50 100  50  50
Sandpoint      35  44  38  48  38  46 /   0  30  50 100  90  80
Kellogg        40  50  43  49  40  46 /   0  20  20 100  90  90
Moses Lake     34  45  38  56  39  53 /   0  20  20  70  10  30
Wenatchee      39  49  42  53  40  49 /   0  10  40  90  40  60
Omak           36  47  38  48  34  45 /   0  10  40  90  30  50

&&

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

&&

$$