554
FXUS66 KOTX 171140
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
440 AM PDT Tue Sep 17 2024

.SYNOPSIS...

Periods of rain will persist over north Idaho and the eastern
third of Washington through early Wednesday. Conditions will
trend drier toward the end of the work week, then precipitation
chances return for the weekend.

&&

.DISCUSSION...

Today through Thursday night: Showers will increase along the WA/ID
border this morning as the wrap around moisture sets up behind the
low that has moved over Nevada. Another low is tracking down along
the coast, but most of the moisture will remain on the west side of
the Cascades. Rain totals will be less than a quarter inch in the
heaviest showers, with, most of the area seeing a tenth or less.
Temperatures will cool towards seasonal normals today, with the
exception of the Okanogan Valley warming to temperatures similar to
yesterday. Winds will remain generally in the 10 to 15 mph range,
with occasional gusts to 20 in the Columbia Basin.

The chance of showers will continue into the overnight hours, with
the low shifting eastward in the early morning hours. A slight
chance of showers continues in the Idaho Panhandle, but by early
afternoon, the region is anticipated to dry out. Temperatures will
continue to be near seasonal normals for Wednesday and Thursday,
with dry conditions persisting through the day Thursday as weak
ridging builds over the region. /KM

Friday to Monday: The Inland NW will be in a progressive west-
northwest flow, with a series of weak waves crossing the region
starting this weekend. Friday looks mostly dry except for slight
showers in the onshore flow near the Cascade crest and over the
far northern Panhandle. Some breezy conditions are also in the
forecast Friday, with gusts of 15-20 mph. Then shower chance
expand some Saturday to Monday. The best chances remain around the
mountains Saturday, then increase over a larger portion of the
area heading into Saturday night, Sunday and Monday. The deeper
Columbia Basin will have the smallest risk and the higher risk
will remain in the mountains. Right now these weak systems are not
expected to be big precipitation producers, if anything falls.
There is still some disagreement in the details of the timing and
track of the individual features, but overall models have trended
showing most models showing lighter precipitation.

Temperatures will be near the slightly below normal. Some patchy
frost is possible in some of the sheltered valleys around north-
central to northeast WA and the ID Panhandle Saturday morning and
even more isolated fashion Sunday morning. There could also be
some patchy morning fog in the sheltered valleys and around the
bodies of water. /Solveig


&&

.AVIATION...
12Z TAFS: VFR conditions will prevail. Scattered showers will
continue to rotate north up into SE Washington, the Idaho
Panhandle, and far eastern reaches of NE Washington through
tonight.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence of increasing showers for SE WA and N Idaho through
tonight. Some models show some localized heavier showers, but
confidence of these impacting the TAF sites KPUW, KLWS, KCOE
carries lower confidence.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        73  49  76  49  76  47 /  40  20  10   0   0   0
Coeur d`Alene  71  48  72  48  75  48 /  60  40  20   0   0   0
Pullman        65  45  69  43  73  45 /  60  30  20   0   0   0
Lewiston       74  54  76  53  79  53 /  60  20  10   0   0   0
Colville       77  38  78  39  76  38 /  20  20  10   0   0   0
Sandpoint      70  46  72  45  73  44 /  50  50  20   0   0   0
Kellogg        66  49  67  50  72  49 /  70  60  30  10   0   0
Moses Lake     79  48  79  46  78  46 /   0  10   0   0   0   0
Wenatchee      78  55  80  53  79  53 /   0   0   0   0   0   0
Omak           83  51  82  51  81  48 /  10  10   0   0   0   0

&&

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

$$