378
FXUS66 KOTX 290814
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
114 AM PDT Tue Sep 29 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...
Today and tonight: An atmospheric river aimed at Vancouver Island
and southern British Columbia will sag south over northern
Washington into the North ID Panhandle this morning and then
remain nearly stationary into the afternoon. Strong westerly flow
into the Cascade crest combined with the increase in moisture
will result in steady rains into the west slopes of the Cascades,
with some precipitation spilling over the crest into the upper
reaches of the Methow Valley, Lake Chelan, and Lake Wenatchee.
Some dry air initially combined with a strong rain shadow east of
the Cascades will result in mainly dry conditions except for areas
of light rain in the mountains of NE Washington into the ID
Panhandle. This system will also bring in a 130 kt upper jet into
southern British Columbia. This will keep our region on the
southern, and thus stable side of the jet which will limit our
mixing potential. Yet as 850mb winds increase to 20-30 kts out of
the southwest windy conditions will occur in the mountains, with
breezy winds across the Columbia Basin, Wenatchee Area, Waterville
Plateau, West Plains, and Palouse. These winds also have the
potential to pick up patchy blowing dust near recently plowed
fields.

Wednesday through Monday: Models are in good agreement that a
transition from westerly flow to a strong upper ridge will occur
late in the week bringing about a warming trend. Yet there are a
couple of weak waves in the westerly flow that will track through
Wednesday and Thursday. The most likely scenario given the lack of
lift is for passing mid and high clouds. Yet the NBM is carrying a
20-30 percent chance of lingering light rain Wednesday morning in
the Central Panhandle Mountains, and then on Thursday a weak wave
bringing a 20-30 percent chance of rain to the Cascades and a 5-10
percent chance elsewhere. Once the ridge strengthens Friday into
Saturday confidence increases of the region going into a prolonged
warm spell with dry conditions. The latest 6-10 and 8-14 day
outlooks from the Climate Prediction Center also support this. JW

&&

.AVIATION...
06Z 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        66  46  67  44  68  46 /  20  10   0   0  10  10
Coeur d`Alene  62  49  65  43  66  45 /  20  10  10   0  10  10
Pullman        66  47  65  42  68  45 /   0  10   0   0   0   0
Lewiston       74  53  70  47  73  51 /   0  10   0   0   0   0
Colville       65  38  66  36  68  38 /  10  10   0   0   0  10
Sandpoint      61  43  64  40  65  42 /  30  20  10   0  10  10
Kellogg        60  48  62  44  65  47 /  10  30  20   0  10  10
Moses Lake     72  45  70  44  71  45 /  10  10   0   0   0   0
Wenatchee      69  50  68  52  69  53 /  20  10   0   0  10  10
Omak           66  41  68  42  69  43 /  10  10   0   0   0   0

&&

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

&&

$$