927
FXUS66 KOTX 230503
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1003 PM PDT Sun Sep 22 2024

.SYNOPSIS...

A weak weather system will deliver increasing clouds and warmer
overnight low temperatures for tonight. A ridge of high pressure
will deliver above normal temperatures Monday and Tuesday. A more
active pattern is expected toward midweek and beyond, with the
potential for breezy conditions and showers. Temperatures return
to near normal by Thursday.

&&

.DISCUSSION...
Tonight through Tuesday Night: A warm front will spread increasing
mid and high clouds over the region tonight into Monday morning.
The bulk of the lift will pass north of the Canadian border with
the chance of rain limited to mainly the Cascade crest. Cloud
cover will help moderate lows tonight with lows mainly in the mid 40s
to mid 50s. Upper level high pressure moves over the region on
Tuesday with the ridge axis pushing into eastern Idaho and western
Montana in the afternoon. This will result in warmer southwest
flow with 850mb temps climbing to near 20C supporting high
temperatures warming into the 80s for most towns.

Wednesday and Wednesday Night: The ridge pushes east into the
midwest while a closed low in the Gulf of Alaska sends a cold
front across the Inland Northwest late Wednesday. The front
reaches the Cascades late in the afternoon before swinging into
Eastern WA/N Idaho Wednesday evening. This is a stronger front
(typical for late September) with a 100 kt south to north upper
jet paralleling the front. Yet the initially dry low levels and
quick movement will result in the best chances for rain along the
Cascade crest (70-80 percent), and the Idaho Panhandle (50-60
percent). The front also will bring a burst of cold advection
supporting breezy to windy conditions, especially across the
Wenatchee area, Columbia Basin, West Plains, and Palouse with
30-35 MPH gusts expected, locally to 40 MPH. Given the dry
conditions and time of year these winds will likely pick up patchy
blowing dust for the Columbia Basin. Elevated instability along
and ahead of the front over the Blue Mountains into the Central
Panhandle Mountains will lead to a 20% chance of thunderstorms
Wednesday evening as well.

Thursday through Sunday: After a quiet Thursday, ensembles show
another system passing into British Columbia on Friday sending
another cold front across the region. This time the jet is zonal
(west to east), with a noteable dry slot moving across the region.
Another round of breezy to locally windy conditions is expected.
Ensembles show a larger spread in wind gusts for the region, but
currently 80-90% of the solutions favor winds below wind advisory
criteria. Drier air behind the front will lead to colder overnight
lows next weekend, with the main frost potential for areas that
just had a frost this past weekend.

The winds Wednesday and Friday will lead to elevated fire weather
conditions across the Columbia Basin, and the East Slope Cascade
valleys. Relative humidity looks to stay above critical
thresholds. JW

&&

.AVIATION...
06Z TAFS: VFR conditions. Bands of mid and high clouds have moved
over the region and will thicken into tonight. There is a 30
percent chance of showers for the Cascades through the night and
into early tomorrow morning. Winds will be light.

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

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        52  78  51  86  57  85 /   0  10   0   0   0  20
Coeur d`Alene  50  75  51  84  56  84 /   0  10   0   0   0  20
Pullman        49  72  49  82  55  83 /   0   0   0   0   0  20
Lewiston       56  80  56  89  61  89 /   0   0   0   0   0  10
Colville       46  78  43  83  45  83 /   0  10   0   0   0  10
Sandpoint      47  72  47  79  52  80 /   0  10   0   0   0  20
Kellogg        49  70  53  81  60  80 /   0  10   0   0   0  10
Moses Lake     55  82  53  86  55  84 /   0  10   0   0   0  10
Wenatchee      60  82  59  84  61  80 /  10  10   0   0   0  20
Omak           55  85  56  87  58  84 /  10  10   0   0   0  30

&&

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

$$