494
FXUS66 KOTX 081326
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
526 AM PST Mon Dec 8 2025

.KEY MESSAGES...

- Strong west to southwest winds Monday evening into early
  Tuesday morning may result in downed trees and power outages.

- Heavy mountain rain will bring a risk for flooding in the
  Cascades and the Idaho Panhandle, especially in steep areas
  and near burn scars.

&&

.SYNOPSIS...
An active weather pattern will impact the area through the week.
A series of warm and wet weather systems will result in periods
of heavy mountain rain, lowland rain, high mountain snow, and
gusty winds. Widespread strong wind gusts are expected Monday
night into Tuesday which may result in downed trees and power
outages.

&&

.DISCUSSION...
Today through tomorrow: A first in a series of atmospheric rivers
will impact the forecast area today through tomorrow. With warm and
moist air moving in, PWATs will rise to 200-250% of normal by
tomorrow morning. This first round of precipitation has snow levels
around 3000-5000 feet, meaning most mid and low elevation areas will
see rain and snow will be confined to the mountains. Snowfall
through tomorrow night will total a few inches, with minor impacts
expected along mountain passes. Stevens Pass has a 65% chance of 2
inches of snow or more, while Blewett Pass has a 10% chance for
those same totals. By early tomorrow morning, NBM probabilities of
24-hour rainfall give Spokane, CdA, Deer Park, Sandpoint, and
Pullman a 60-80% chance of 0.25 inches of rain. Due to snow levels
being so high and mid to low elevation snowmelt occurring, main
impacts from precipitation will be hydrological in nature. Rivers
and streams could see an uptick in streamflow, with Stehekin
River nearing Action Stage by tomorrow morning. Another
hydrological impact will be an increased chance for mud and
rockslides, especially in steep terrain and in or around any
burn scars. Due to this impact, a Flood Watch has been issued
for Chelan County through late tonight.

Wind gusts: as a surface low drops into Montana, the surface
pressure gradient across the state of Washington will increase,
leading to gusty winds across the majority of the forecast area. The
Basin and Palouse will see the highest wind gusts, with
Spokane, Pullman, Moses Lake, and Ritzville seeing a 50-60%
chance of wind gusts 40 mph or higher. A Wind Advisory has been
issued for much of the Idaho Panhandle and eastern Washington,
and is valid through 7am on Tuesday. Strongest wind gusts will
be seen Monday night through early Tuesday morning. Main impacts
that could be seen are blowing objects, damage to trees and
branches, and difficulty driving high profile vehicles.

Tomorrow morning through Thursday: Tuesday will have a small break
in precipitation during the day before the second atmospheric river
impacts the area Tuesday night into Thursday. PWATs remain
anomalously high, with a rise in some areas to 250-300% of normal.
Snow levels will be higher with this storm, starting at around 4000
feet and rising steadily throughout the event to 5000-7000 feet.
Snowfall during this second system will be heavier than the first.
The bulk of the snow will fall Tuesday night through Wednesday. More
mountain passes have a chance at seeing a few inches of snow.
Blewett, Lookout, and Stevens Passes have a 15-25% chance of seeing
two inches of snow or more, and Sherman Pass has a 55% chance of
seeing those snow totals. With this second surge of rain, hydrologic
impacts along rivers and streams become even more likely. A
Hydrologic Outlook has been issued for two river forecast points in
Idaho that are forecast to see impacts due to streamflow rises. The
Coeur d`Alene River at Cataldo forecast point will reach Minor Flood
Stage at 43.50 feet, and Paradise Creek at Moscow will reach Action
Stage at 8.5 feet. By Thursday morning, much of the basin has a 50-
60% chance and above of 72-hr rainfall totals near 0.75 inches.
Mountain areas and foothills have a 60-90% chance of seeing an inch
or more of rain by Thursday morning.

The pressure gradient will have relaxed by this second system, so
winds will have decreased. Basin and Palouse areas remain breezy
with gusts 20-25 mph on Tuesday night, but will decrease down to 10-
15 mph by Wednesday night. With this decrease in gusts, chances for
wind headlines during this time are decreasing.

By next weekend, clusters still show a somewhat active pattern,
particularly in the mountains. The Extreme Forecast Index shows very
anomalously high QPF values in the mountains and into the foothills.
Temperatures remain above normal due to the warmth of the moisture
moving in. The lowlands will get a bit of a break from
precipitation. Right now, all clusters show higher heights moving
into the area, and roughly a quarter of clusters show a bit of
disagreement in the location of these heights. The Climate
Prediction Center`s 6-10 and 8-14 Day Outlook indicates continued
increased chances of higher than normal temperatures and
precipitation. Long range models show chances for another warm, wet
active pattern moving through early next week, so stay tuned.
/AS

&&

.AVIATION...
12Z TAFs: As one wave exits, another is right behind it. Rain
chances will steadily increase through the period starting
around 15Z across the Inland Northwest. After 18Z, PoPs are
high enough to support steady precipitation. With this rain
moving in, ceilings will drop back down to MVFR/IFR. Airports
that have the highest chance of IFR conditions are
KGEG/KSFF/KCOE/KPUW. Increasing winds through the TAF period
will bring period of LLWS but confidence is low on timing. Winds
will peak through the overnight hours with eastern sites having
gusts into the 40 kt range excluding KEAT-KMWH.


.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Moderate confidence in southwest wind gusts continuing for
KGEG/KSFF/KPUW/KMWH through 18Z, but high confidence in stronger
southwest wind gusts moving in around 21Z. cig improvements as a
cold front sweeps through this evening. /JDC

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

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        50  42  49  39  50  41 /  90  80  50  90  80  60
Coeur d`Alene  49  42  48  38  49  42 / 100 100  60 100  90  70
Pullman        50  43  49  41  52  45 /  90  90  90 100  90  80
Lewiston       54  49  55  46  58  51 /  90  90  90 100  90  70
Colville       46  34  45  33  44  33 /  90  80  30  90  70  50
Sandpoint      46  38  46  35  44  38 / 100 100  50 100 100  80
Kellogg        47  41  46  38  48  42 / 100 100  80 100 100  90
Moses Lake     53  43  49  40  54  41 /  70  50  60  90  60  40
Wenatchee      50  41  48  40  51  41 /  90  80  60  90  80  60
Omak           46  35  45  35  44  35 /  80  70  20  90  60  50

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 7 PM this evening to 7 AM PST Tuesday for
     Lower Garfield and Asotin Counties-Northeast Mountains-
     Spokane Area-Upper Columbia Basin-Washington Palouse.
     Flood Watch through late tonight for Central Chelan County-
     Wenatchee Area-Western Chelan County.
ID...Wind Advisory from 7 PM this evening to 7 AM PST Tuesday for
     Central Panhandle Mountains-Coeur d`Alene Area-Idaho
     Palouse-Lewiston Area-Northern Panhandle.

&&

$$