Lewiston, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

603
FXUS66 KOTX 161242
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
442 AM PST Tue Dec 16 2025

.KEY MESSAGES...

- High confidence for high winds Tuesday night into Wednesday
  morning with a 40% to 80% chance of wind gusts greater than 60
  mph across much of the region. Tree and powerline damage and
  widespread power outages possible.

- Rain and high mountain snow through early Wednesday to bring
  additional river rises and mud and rock slide concerns to
  Cascades and Idaho Panhandle.

- High confidence for heavy mountain snow impacting the Cascades
  starting overnight Tuesday. There is a 90% chance of 2 feet
  or more of snow at Stevens Pass through Friday afternoon.

&&

.SYNOPSIS...
An extremely active pattern will continue to impact the Inland
Northwest through Thursday. Rain and high mountain snow through
Tuesday night will bring additional river rises with mud and rock
slide concerns in steep terrain of the Cascades and Idaho Panhandle.
Strong, potentially damaging winds, will then develop Tuesday night
into Wednesday, as well as rain transitioning to heavy snow at
pass levels. Temperatures cool toward the end of the week but
still remain above normal. Additional weather systems are
forecast to bring more snow to the mountains and a wintry mix to
the valleys heading into the weekend.

&&

.DISCUSSION...

...VERY ACTIVE WEATHER PATTERN CONTINUES THROUGH THURSDAY WITH
RENEWED FLOODING CONCERNS FOR CASCADES AND NORTH ID PANHANDLE
TUESDAY, HIGH WINDS TUESDAY NIGHT INTO WEDNESDAY, AND HEAVY MOUNTAIN
SNOW FOR THE CASCADES WEDNESDAY THROUGH THE END OF THE WEEK...

Tuesday through Wednesday: This time period will be characterized by
expanding precipitation chances, lowering snow levels, and strong,
damaging winds.

*Precipitation Amounts: Chances for precipitation will be focused
mainly over the Cascades, northeast WA mountains, and ID Panhandle
mountains during the day on Tuesday with limited chances (10-30
percent chance) for lowland areas including the Basin, Palouse, and
Spokane/Coeur d`Alene. Precip chances become widespread across the
region Tuesday night into Wednesday. Forecast precip totals by
Wednesday night range from 3 to 5 inches along the Cascade Crest, 1
to 3 inches along the mid slopes, and 0.10 to 0.40 inches for valley
floors. The deeper Columbia Basin will see the lightest amounts with
less 0.10 inches forecast. The ID Panhandle will generally range
from 0.40 inches to 1 inch with higher amounts for the mountains.

*Snow: Snow levels early Tuesday will range from 3000 feet for the
North Cascades and Okanogan highlands to 4000 feet for the Central
WA Cascades to around 5500 feet for the Blues. Snow levels will rise
to between 5000 and 6500 feet through the day on Tuesday, then
rapidly fall to between 1000 and 2000 feet by Wednesday morning
following the passage of a cold front. This rapid drop in snow
levels will coincide with precip chances ending due to dry air
moving in behind the front, so lowland snow accumulations are not
anticipated. For the Cascades, snow will ramp up Tuesday night into
Wednesday with 12-18 inches forecast by Wednesday night near the
Cascade crest. Thus, a Winter Storm Warning has been issued. Strong
winds may result in blowing snow, reducing visibilities. Other
mountain passes including Sherman and Lookout are forecast to
receive 1 to 3 inches of snow.

*Strong Winds: A rapidly intensifying surface low tracking across
southern BC into Alberta Tuesday Night into Wednesday morning will
produce strong and potentially damaging winds across the region.
Wind speeds have continued to increase with each model run. The
latest run of the National Blend of Models is showing a 50 to 80
percent chance of gusts over 60 MPH across the Columbia Basin,
Cascade Crest, east slopes of the Cascades, and Spokane/CdA area.
Chances increase to between 80 and 95 percent for the southeastern
corner of the region including Pullman, Lewiston, and the Blue
Mountains. For the northern third of Washington, chances are around
20 percent. With all of the recent rain leaving soils saturated,
there will be an especially high risk of tree damage with strong
gusts. A High Wind Warning has been issued for most of the region.

Thursday through Monday: Another surge of precipitation enters by
Thursday. Snow levels start off around 1500-2500 feet but a return
of warmer air from the southwest is expected with the current NBM
raising snow levels to 3000-4000 feet by Thursday evening. More
moderate to heavy snow is anticipated for the Cascades with
potential for multiple feet of accumulation. More on this in the
days to come. /Fewkes

&&

.AVIATION...
12Z TAFs:

.STRONG COLD FRONT TO BRING CONVECTION AND HIGH WINDS ACROSS THE
INLAND NORTHWEST LATE TUESDAY NIGHT INTO WEDNESDAY MORNING.

Today will be a break between frontal systems. Moist westerly
flow across the Palouse into the Spokane-Coer d`Alene area will
result in low clouds developing with the potential for MVFR
ceilings. Winds will be a bit gusty from the south to southwest
into this afternoon. Major to extreme impacts from winds are
expected late tonight with a vigorous cold front passage
between 09-14Z. The front will be preceded by rain and strong
dynamics along the front will bring a threat of convection that
will lead to the potential for heavy rain and isolated
thunderstorms. Higher threat for convective enhancement with
precipitation will be east of a line from KMWH to KOMK. Cold
front passage will bring the potential for wind gusts of 50+ kts
out of west to southwest and convective cells will only enhance
this potential for 60-70 kt wind gusts.

.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence with a probability of 30-60% chance in MVFR
conditions due to low ceilings between 16-22Z at KPUW/KGEG-
KSFF/KCOE. Moderate to high confidence for a convective line
with cold front late Tuesday night into early Wednesday morning.
There is a 20% for thunderstorms to impact KLWS/KPUW/KGEG/KSFF-
KCOE between 10-14Z Wednesday. /SVH

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

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  38  46  33  43  33 /  40 100  50  10  90  80
Coeur d`Alene  48  38  46  33  43  35 /  70 100  70  20  90  90
Pullman        51  36  45  32  44  36 /  40 100  70  10  90  90
Lewiston       59  44  52  37  48  42 /  20  90  60  10  90  90
Colville       45  35  46  28  39  26 /  50 100  50  20 100  80
Sandpoint      44  36  39  30  38  31 /  90 100  90  40 100  90
Kellogg        46  36  44  33  41  35 /  90 100  90  50 100 100
Moses Lake     54  39  48  35  43  33 /  20  90  10  10  80  50
Wenatchee      50  38  45  35  40  30 /  60 100  50  30  90  80
Omak           44  37  42  31  36  25 /  60  90  30  10  90  70

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...High Wind Warning from 10 PM this evening to 4 PM PST
     Wednesday for Central Chelan County-Lower Garfield and
     Asotin Counties-Moses Lake Area-Northeast Blue Mountains-
     Northeast Mountains-Okanogan Highlands-Spokane Area-Upper
     Columbia Basin-Washington Palouse-Waterville Plateau-
     Wenatchee Area-Western Chelan County.
     Flood Watch through Wednesday morning for Central Chelan
     County-Wenatchee Area-Western Chelan County-Western
     Okanogan County.
     Winter Storm Warning from 4 PM this afternoon to 10 PM PST
     Wednesday for Western Chelan County.
ID...Flood Watch from this afternoon through Wednesday afternoon
     for Central Panhandle Mountains-Coeur d`Alene Area-Idaho
     Palouse-Northern Panhandle.
     High Wind Warning from 10 PM this evening to 4 PM PST
     Wednesday for Central Panhandle Mountains-Coeur d`Alene
     Area-Idaho Palouse-Lewis and Southern Nez Perce Counties-
     Lewiston Area-Northern Panhandle.

&&

$$