Lewiston, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

296
FXUS66 KOTX 070603
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1003 PM PST Fri Mar 6 2026

.KEY MESSAGES...

- Windy on Sunday with widespread gusts 30-45 mph.

- Colder with moderate to heavy mountain snow next week,
  especially over the Cascades and the Idaho Panhandle.

- Elevated winds through next week. Periods of strong winds.


&&

.SYNOPSIS...
A strong cold front will bring gusty westerly winds on Sunday.
Persistent snow showers will bring several days of winter travel
conditions over the mountains next week. We are monitoring
Wednesday into Thursday for lowland snow across northern
Washington and North Idaho. Elevated winds expected through the
week.

&&

.DISCUSSION...

...WINDY CONDITIONS SUNDAY...
...WINTER TRAVEL OVER MOUNTAIN PASSES NEXT WEEK...

Tonight-Saturday: Moisture spilling over the eastern flank of an
upper-level ridge will bring increasing clouds through this
evening. Precipitation chances will be on the rise overnight as
the moisture is squeezed out along a weak frontal boundary.
Rainfall amounts will be extremely light in the lee of the
Cascades and around a tenth in the lowlands of North Idaho and
Eastern WA. The air mass will be mild with mainly rain or wet,
non accumulating snow on the mountain passes.

There will be a noticeable increase in winds across the Inland NW.
We are already seeing gusts 25-35 mph along the Cascade East
Slopes, Waterville Plateau, and foothills of the Blue Mountains
this afternoon. Pressure gradients will be increasing further
heading into Saturday as a 990mb low tracks through north-
central BC-Saskatchewan. The track of this low is far enough to
the north to keep concerns for stronger winds at a minimum,
though widespread gusts 25-35 mph will be common. Local gusts of
35-45 mph will impact the higher peaks of the Cascades, Blue
Mountains, and at times, mix to the benches around East
Wenatchee, Entiat, and Waterville Plateau.

Sunday: The upper-level ridge will retrograde with a stronger and
deeper shortwave spinning through south-central BC-Saskatchwen.
This will result in a deeper low pressure system tracking
through western Canada and continue to ramp up pressure
gradients and winds for the INW. Nearly all models support wind
gusts of 30-40 mph (70-80% chance via the NBM) and 40-70% chance
for wind gusts 40-50 mph. The greatest anomalies are showing up
across the northern two-thirds of WA and far North Idaho. This
is does equate to where the strongest winds will be but more
indicative that these typically "less windy" areas will be
experiencing gusts of at least 30 mph. Wind direction will be
from the west/southwest in the morning and early afternoon with
a subtle shift to the west/northwest in the late afternoon and
evening. Impacts from the winds will be choppy lakes,
challenging cross winds, and potential for isolated tree damage
and power outages. Mountain showers will accompany the windy
system. Snow levels will start off 5000-6000 feet and lower in
the Cascades by Sunday evening to 2000 feet or lower with snow
and winter travel conditions returning to the Cascade passes.

Monday-Friday: There is good agreement for a strong Polar Jet
to reside over the PacNW with wavering north and south from
southern BC/Alberta to WA/OR border. The placement of this jet
suggest an active storm track for the Northwest. What we do
know, there will be a prolonged period of snow showers
bombarding the Cascade Crest with 3-4 day snow amounts measured
in feet. Current NBM has a 60% chance 3 feet or more of snow
over the 72 hour period ending Thursday night. The Cascades will
intercept a bulk of the moisture but the strong west to
northwest flow and orographics will allow for appreciable
amounts over the multi-day period in the Central Panhandle
Mountains and portions of the Selkirks of North Idaho and far
NE WA. Lookout Pass has a 70% chance for at least 1 foot of snow
and 25% chance for 2 feet.

For much of the period, the strong west to northwest flow will
result in significant precipitation shadowing across much of
Central and Eastern WA. The exception will be when shortwaves
ripple through the jet and can result in cyclogenesis or
development of surface lows. Models have been latching on to
such an event for a few days during the March 11-12th or
Wednesday-Thursday period. These systems have the potential to
disrupt the strong shadowing and bring light to moderate
precipitation to the lowlands and Kettle Mountains. This could
be impactful bringing the potential for lowland snow. The
details are far from certain this far out given several
outcomes where the exact low will track and where the lowland
rain/snow will set up out, but something we are closely
monitoring.

The synoptic setup will undoubtedly result in multiple days of
breezy to windy conditions given the placement of the jet over
the region. Oscillations of the jet north and south will help
determine which will be the windiest periods. It is common to
for the windiest periods to come during times of cold advection.
When on the warmer side of the jet, we will closely monitoring
for mountain waves and infrequent strong gusts. These are much
more challenging to forecast in the lowlands. The aforementioned
surface lows spinning up will also enhance winds for the
lowlands and deliver wind shifts. All that being said, there is
moderate uncertainty in precise day to day details but be
prepared for elevated/impactful winds next week. /sb

&&

.AVIATION...
06Z TAFS: Weak warm air advection will bring light rain to far
eastern Washington and north Idaho over the next couple of
hours. The boundary layer has been slow to moisten from the top
down with rain and deteriorating conditions arriving later than
previously forecasted. Best chances for precipitation at
KGEG/KSFF are through 09Z and at KCOE/KPUW through 12Z. Expect
ceilings to gradually decrease early Saturday morning to MVFR at
KGEG/KSFF/KCOE/KPUW/KLWS by 15Z and gradually improve through
the early afternoon. The exception will be at KCOE where models
delay improvements until the early evening. Winds will begin to
increase by the late morning with gusts 20-30 knots through
early Saturday evening. As winds increase aloft this morning,
this may result in a short period of LLWS at KEAT until stronger
surface winds develop around 17Z.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate to high
confidence for MVFR across far eastern Washington and north
Idaho Saturday morning. Moderate confidence for IFR ceilings
developing at KCOE. High confidence for ceilings to gradually
improve to VFR through the afternoon. High confidence for breezy
west to southwest winds late Saturday morning into the evening.

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

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        43  59  43  56  30  43 /  50  10   0  20  20  20
Coeur d`Alene  41  54  43  54  30  43 /  70  40  10  60  40  50
Pullman        41  55  42  54  31  41 /  60  30  10  50  50  60
Lewiston       45  63  44  62  37  48 /  50  20   0  20  40  30
Colville       39  57  40  57  28  44 /  50  10   0  20  10  20
Sandpoint      39  50  42  50  30  41 /  80  60  30  80  40  60
Kellogg        38  50  43  49  32  38 /  90  80  40  90  70  80
Moses Lake     44  65  44  62  31  49 /  40  10   0   0   0   0
Wenatchee      45  63  45  56  33  45 /  30  10  10  30  10  20
Omak           41  60  41  60  29  46 /  40   0  10  10  10  10

&&

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

&&

$$