662
FXUS66 KOTX 282323
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
423 PM PDT Mon Sep 28 2026

.KEY MESSAGES...

- Breezy west to southwest winds may result in patchy blowing
  dust near recently plowed fields Tuesday afternoon.

- Mild and dry pattern this week, except for rain near the
  Cascade crest and chance of rain North Idaho Panhandle on
  Tuesday.

&&

.SYNOPSIS...
Moisture off the Pacific will bring rain to the Cascade crest
and northeast Washington and north Idaho mountains on Tuesday.
Breezy west to southwest winds may result in patchy blowing dust
near recently plowed fields Tuesday afternoon. Temperatures
will be near normal through the middle of the week and then
trend to above normal for the end of the week and into the
weekend.

&&

.DISCUSSION...
Monday night through Tuesday: : Weak troughing over the Inland
Northwest will depart eastward today, transitioning to zonal flow
aloft over the Pacific Northwest tonight. A frontal system moving
into northern British Columbia will direct a moisture plume into the
Washington Cascades, supported by a 120-125 kt upper-level jet
streak positioned north of the international border. This setup
favors orographically driven precipitation developing along the
Cascades early Tuesday, spreading into northeast Washington and
north Idaho mountains Tuesday afternoon. Precipitation amounts will
be maximized across the west slopes of the Cascades and at the
Cascade crest with high confidence (greater than an 80% chance) for
amounts exceeding 0.50 inches. Strong westerly flow aloft into the
Cascades will produce a pronounced rain shadow east of the crest,
with amounts quickly dropping off farther east. Precipitation
amounts will be much lighter across northeast Washington with a 50%
chance for 0.10 inches of rain across the northern Selkirks and a
25% chance as far south as Mount Spokane.

Winds will also be breezy on Tuesday as 850mb winds increase to 20-
30 knots. The Inland Northwest will be within the warm sector with
the boundary layer only mixing up to around 800mb Tuesday afternoon.
This will limit the stronger winds at 700mb to materialize down to
the surface. Despite lower mixing heights, the National Blend of
Models shows a 60-80% chance for wind gusts greater than 30 mph
across the Columbia Basin into the Spokane West Plains Tuesday
afternoon. These gusts may result in patchy blowing dust near
recently plowed fields.

Wednesday through Sunday: A warming trend is anticipated as ensemble
guidance depicts an upper-level ridge amplifying across the western
US. Uncertainty exists Thursday into Friday regarding the northward
extent of the ridge axis. Approximately 45% of ensemble members
favor persistent zonal flow, which would direct another moisture
plume into the Pacific Northwest with an additional period of light
mountain precipitation. The remaining 55% of members build the ridge
more aggressively over the region, supporting a drier solution.
Ensembles are in better consensus for the upper-level ridge to
become established over the western US this weekend, resulting in
warm and dry conditions across the Inland Northwest. /vmt

&&

.AVIATION...
00Z TAFS: Mid and high clouds will be on the increase tonight
due to an arrival of moisten laden westerly 500mb jet. The
strong westerly flow across the Cascades tonight into Tuesday
will promote lee waves and favorable pattern for turbulence with
gusty winds surfacing in the lowlands by Tuesday afternoon. The
Cascade crest will likely experience widespread mtn
obscurations Tuesday as well with steady precipitaiton. JW

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for VFR conditions at all TAF sites through Tuesday.

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

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        45  67  47  68  45  69 /   0  10  10   0   0   0
Coeur d`Alene  43  63  48  65  45  67 /   0  10  10   0   0  10
Pullman        42  66  46  65  43  69 /   0   0  10   0   0   0
Lewiston       46  74  53  71  49  74 /   0   0   0  10   0   0
Colville       41  66  38  67  36  69 /  10  20  10   0   0  10
Sandpoint      41  61  44  64  41  65 /   0  30  20  10   0  10
Kellogg        42  61  48  63  45  67 /   0  10  30  20   0  10
Moses Lake     46  73  47  71  44  73 /   0  10   0   0   0   0
Wenatchee      50  69  51  69  52  70 /  10  20  10   0   0   0
Omak           48  67  43  69  45  70 /   0  10  10   0   0   0

&&

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

&&

$$