Lewiston, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

994
FXUS66 KOTX 060905
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
105 AM PST Sat Dec 6 2025

.KEY MESSAGES...

- Moderate to heavy mountain snow through Saturday at the
  Cascade crest and the Idaho Panhandle mountains. 60% chance
  and above for 10+ inches at Stevens and Lookout Passes.

- Strong, potentially damaging winds in portions of Central
  Washington through Saturday morning. Gusty winds in southeast
  Washington.

- Increased potential for rises along small creeks and streams
  and rock slides next week due to a very wet and warm pattern
  moving through.

&&

.SYNOPSIS...
A very active weather pattern will continue to impact the area
and bring winter and wind impacts through Saturday. Sunday into
next week, a series of very wet and warm systems will move
through. This will result in warmer than normal temperatures,
mountain snow, rain, and strong wind gusts.


&&

.DISCUSSION...
Today through tonight: A series of shortwaves embedded within the
upper level trough combined with a potent surface low is bringing
wintry and windy conditions to the areas today and tonight.
With PWATs near 150-200% of normal, and temperatures tomorrow
set to be 5-8 degrees warmer than normal, snow levels will be
around 3500-4000 feet, limiting snow to mountain areas. For snow
totals, HREF and NBM show a 60 percent chance and above for
Lookout and Stevens Passes to see 10 inches of snow, with
deterministic ranges in the 10-18 inch range. Additionally, the
HREF is showing a 70% chance for both Lookout and Stevens Passes
to see 1 inch per hour snowfall rates through early this
morning. With total snowfall combined with heavier snowfall
rates, winter travel impacts along mountain passes will be
moderate, leading to a Winter Storm Warning being issued for
both mountain passes. The Idaho Winter Storm Warning ends at 4pm
Saturday, while the Washington Winter Storm Warning ends at
11pm Saturday. Bottom line: if you must travel across these
mountain passes, expect moderate travel impacts and heavy
snowfall rates.

Additionally, a tight surface pressure gradient has resulted in
strong wind gusts being observed across the Cascades and southeast
Washington. Wind gusts over 70 mph were observed near Mission Pass
Summit, and Lewiston/Pullman are currently seeing wind gusts near 45
mph. In particular, wind gusts along the Cascades could further
contribute to travel impacts. Stevens Pass has an 85 percent chance
of seeing wind gusts 45 mph or more through the next few hours. A
Wind Advisory is valid for the Pullman, Clarkston, and Moscow areas
through 7am this morning. A High Wind Warning is in effect for
Wenatchee, Moses Lake, Waterville, and Ephrata through 7am this
morning. These wind gusts, especially in the High Wind Warning area
along mountain passes could create blowing snow issues, which is
mentioned in the Winter Storm Warning for Stevens Pass. Right now,
the heaviest wind gusts have struggled to reach the basin and
Spokane/CdA area, with gusts 20-25 mph observed in these areas.
Winds will remain elevated through tonight.

Sunday through Wednesday: The active weather pattern will continue
well into next week with a series of atmospheric rivers impacting
the forecast area. PWATs will drop to right around 100% of normal
for some of the day Sunday, but this drop will be very brief. Late
Sunday morning, the first surge of warm, moist air will move through
and raise PWATs back to 150-200% of normal. Snow levels will start
out around 4000 feet and increase steadily through the week, which
will result in mainly rain for the lowland areas and heavy snowfall
for the mountains. By early Monday morning, NBM probabilities of 24-
hour rainfall give Spokane, CdA, Deer Park, Sandpoint, and Pullman a
60 percent chance and above of 0.25 inches of rain. The second surge
of moisture will move through Monday night into Tuesday, bringing
PWATs even higher, to 200-250% of normal. A similar increase in
PWATs will occur Wednesday through Thursday as well. While in the
extended period at this point, long-range models are indicating the
series of systems next week to have a significant impact on the
area. The Extreme Forecast Index shows very anomalously high QPF,
wind/wind gusts, and temperatures Tuesday through Thursday. All
clusters show strong lower heights moving into the area with
embedded shortwaves. The Climate Prediction Center`s 6-10 Day
Outlook indicates increased chances of higher than normal
temperatures and precipitation.

With snow levels being so high, it is looking more and more like
hydrological impacts may occur alongside wintry travel conditions
and high winds. A Hydrologic Outlook has already been issued for
next week indicating rises on small creeks and streams due to low
elevation snowmelt. Any moderate or high impact burn scars will
continued to be monitored closely for any potential impacts.
Additionally, there will be an increased risk for mud and rock
slides in areas of steep terrain. We will be keeping a very, very
close eye on this series of systems next week due to the potential
for multiple weather headlines and impacts. /AS

&&

.AVIATION...
06Z TAFs: All TAF sites but KPUW/KLWS/KEAT are IFR/LIFR at the
moment. The winds moving through have mostly scoured out the
layer of stratus, allowing fog to form and ceilings to drop.
Lots of prob 30 groups in the TAFs for rainfall and the
occasional improved ceiling. Nearly all of this precipitation
will be rain, though can`t rule out a few snowflakes at KEAT.
Chances of rain increase through the forecast period and through
the next forecast period for most TAF sites. KPUW/KLWS are
currently seeing wind gusts 30-35kts. NBM probabilities have the
wind gusts already at nearly every site, but the HREF shows
wind gusts moving into the KGEG/KSFF/KCOE regions later, so a
slight lack in confidence about when wind gusts will arrive.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence in precipitation chances increasing through the
TAF period. Moderate to low confidence in when strongest wind
gusts will surface, especially near KEAT/KSFF/KCOE. /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  44  35  43  38  49 /  50  30  20  80  60  80
Coeur d`Alene  35  43  35  43  38  47 /  80  70  50  90  80  90
Pullman        38  44  37  43  40  48 /  70  60  60  80  80  80
Lewiston       41  51  40  47  43  52 /  70  50  40  70  70  70
Colville       33  41  28  39  33  44 /  40  40  20  90  50  80
Sandpoint      33  39  34  39  37  43 /  80  90  80 100  90 100
Kellogg        35  39  37  41  40  46 / 100 100  90 100 100 100
Moses Lake     36  50  35  45  38  50 /  10  10   0  60  10  50
Wenatchee      38  49  37  45  39  47 /  60  30  20  70  30  70
Omak           34  43  32  40  34  42 /  40  20  10  60  20  60

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 7 AM PST Saturday for Lower Garfield and
     Asotin Counties-Washington Palouse.
     High Wind Warning from 7 PM this evening to 7 AM PST Saturday
     for Moses Lake Area-Waterville Plateau-Wenatchee Area.
     Winter Storm Warning from 7 PM this evening to 10 PM PST
     Saturday for Western Chelan County.
ID...Wind Advisory until 7 AM PST Saturday for Idaho Palouse.
     Winter Storm Warning until 4 PM PST Saturday for Central
     Panhandle Mountains.

&&

$$