652
FXUS66 KOTX 201057
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
357 AM PDT Mon Apr 20 2026

.KEY MESSAGES...

- Dry and warm conditions through Tuesday.

- Breezy winds and increasing risk for showers and
  thunderstorms Tuesday evening.

- Light to moderate rains Wednesday with gusty winds and
  additional chances for thunderstorms.

&&

.SYNOPSIS...
Dry, warm conditions through Tuesday. Unsettled weather returns
Tuesday afternoon into Wednesday next week with potential for
moderate rains, thunderstorms, and gusty winds.

&&

.DISCUSSION...
Today through Tuesday morning: A ridge centered over the state of
Washington will bring drying and warming conditions with little to
no impacts through Tuesday morning. High temperatures will peak
today, with many places reaching the mid-70s and isolated low 80s.
Low temperatures will be in the high 40s to the low 50s.

Tuesday through Thursday: As a low pressure system nears the PNW
coast and moves inland over the California/Oregon border, more
active weather will move through the area. In particular, by midday
Tuesday PoPs will have increased across much of the forecast area.
The current path of the low has it clipping the eastern third of
Washington and the Idaho Panhandle, confining the heaviest
precipitation to this area. The majority of the forecast area will
see at least a wetting rain (0.10 inches) by Wednesday evening.
Wednesday morning through Thursday morning, much of the Idaho
Panhandle and southeast Washington see 0.5 inches of rain. Isolated
higher rainfall totals nearing 0.75-1 inch of rain are possible in
the WA/ID Palouse and in the foothills of the Central ID Panhandle.
This will lead to rises on rivers and streams, and possible nuisance
flooding in poor drainage areas. In particular, Kootenai River at
Bonners Ferry is forecast to go into Action Stage by early Thursday
morning. Stehekin River is seeing ongoing hydrologic issues, and is
expected to reach Minor Flood Stage by Monday. It`s worth noting
that model spread with precipitation totals is very high. The spread
between the 75th and 25th percentile precipitation totals for Wednesday
is 0.5-0.8 inches, which indicates disagreement in the track of
the low. Should the low track further southeast, lower rainfall
totals will be observed. Conversely, should the low track
further northwest, higher rainfall totals will be observed. Stay
tuned for any forecast updates.

Aside from the rain, there are a few other characteristics of this
weather pattern that will result in impacts across the area. Snow
levels with this system will be very high, starting at 8000 feet and
lowering to 4500-5000 feet by Thursday. Much of this snow will be
above pass level. Lookout Pass does have a chance of an inch or so
of snow through Wednesday through Thursday. Bottom line: expect
little to no wintry travel impacts along mountain passes. Chances
for thunderstorms increase, particularly on Tuesday night into early
Wednesday morning as temperatures will still be warm ahead of an
incoming cold frontal passage. CAPE values are modest on Tuesday
night, with 300-500 J/kg expected through Tuesday evening. Main
risks with these thunderstorms will be gusty outflow winds and small
hail. With the frontal passage, winds will increase Wednesday
afternoon, especially across the Cascades, Okanogan Valley and
Highlands, Waterville Plateau, Moses Lake, Basin, and northern Blues
areas, with gusts 20-25 mph expected and locally higher wind gusts
near 35-40 mph. Additionally, high temperatures will drop
considerably, nearly 15-20 degrees, from Tuesday to Wednesday. Low
temperatures will not see quite as dramatic a drop, though it will
still be noticeable at 10-15 degrees.

Friday through Sunday: By Friday, the low pressure system will have
moved out of the area and heights will have increased due to a ridge
off the coast of Canada. This is where clusters and long term models
diverge. There is little agreement in how far the higher heights
move inland. However, even with this disagreement, there will
overall be a warming and drying trend through next weekend with the
departure of the low. /AS

&&

.AVIATION...
12Z TAFS: An upper-level ridge is currently over the Pacific
Northwest with a deep, closed upper-level low offshore. This
will result in VFR conditions and terrain driven winds. Moisture
streaming into the region from the south will bring passing
middle and high level clouds through the period.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
High confidence for VFR conditions.

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

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        75  47  73  46  53  39 /   0   0  10  50  80  50
Coeur d`Alene  75  47  74  46  53  38 /   0   0   0  50  90  70
Pullman        74  47  69  43  48  38 /   0   0  10  70  90  70
Lewiston       78  51  75  49  54  42 /   0   0  10  70  90  70
Colville       78  45  79  47  64  40 /   0   0  10  50  60  40
Sandpoint      73  46  74  47  54  39 /   0   0  10  50  90  80
Kellogg        74  49  75  46  51  39 /   0   0  10  50 100  90
Moses Lake     80  49  77  50  65  43 /   0   0  10  40  50  20
Wenatchee      77  53  75  52  63  46 /   0  10  10  30  30  10
Omak           78  50  78  51  69  42 /   0   0  10  20  30  10

&&

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

&&

$$