039
FXUS66 KOTX 281101
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
401 AM PDT Thu Aug 28 2025

.KEY MESSAGES...

- Scattered showers with isolated thunderstorms through Thursday.
  Thunderstorms will be capable of heavy rainfall.

- Warming up into the 90s next week, locally near 100, with
  elevated HeatRisk.

&&

.SYNOPSIS...
An area of low pressure will bring scattered showers and
isolated thunderstorms to the Inland Northwest through Thursday.
Thunderstorms will bring the potential for heavy rainfall
particularly in the Cascades and in the Idaho Panhandle.
Limited shower chances linger Friday and then brush by the
Cascades later in the weekend. Otherwise drier weather returns,
with temperature warming into next week.

&&

.DISCUSSION...
Today and tonight: a moisture-rich low pressure system migrates
north through this period. Precipitation chances will be found
along the deformation axis over a good chunk of the area this
morning, the potential shifts toward the north and around the
Cascades this afternoon and evening. Some embedded t-storms
will be possible, particularly near the Cascades and closer to
northeast WA and ID Panhandle mountains. There is about 20-30%
chance in these areas. Destabilization on the south side of the
deformation axis will also allow for the additional shower and
isolated t-storm chances to develop around the Columbia Basin
and higher Palouse. Most of the deeper moisture (PWATS around
180-229% of normal) is above 10000 feet so that will limited
precipitation amounts, especially away from the mountains.
However the system will has the potential for some wetting
rains. The best chance outside the mountains will be earlier
today before the boundary lifts north. The chance of wetting
rain (>=0.10") in these areas is around 10-30%, with the higher
risk toward he WA/ID border. Closer the the mountains both this
morning through this evening the potential for wetting rains is
around 20-40%, locally between 60-80% around the Cascades and
central Panhandle mountains early today. Given the burn scars in
the region, a flood watch is in place for the Cascades through
this evening. As we head into late this evening into the
overnight the primary shower chance retreat to the northern
mountains and wane. Given the moisture we will be on the look
out for some patchy fog late tonight into Friday morning over
the eastern third of WA and ID, particularly around the
sheltered valleys and near bodies of water.

Friday a boundary lingers around the north to northeast CWA,
with some modest PWATs still in place at 120-160% of normal. The
afternoon also brings modest instability. This will bring renew
the threat of showers and thunderstorms over the northern WA
mountains and north and central ID Panhandle. These could be
locally stronger with heavy downpours and gusty winds, maybe
some hail. Something to keep an eye on is the potential for some
of this activity outside the mountains, over the north and
eastern basin (including the Spokane area). However ensembles
and CAM models are holding PoPs at around 10% or less in these
areas. Definitely worth monitoring but confidence is too low to
include in the forecast.

Saturday to Wednesday: models bring a deep low pressure trough
toward the region and then retrograde it back into the Pacific
heading into early next week. Models have been pretty
inconsistent over the past several days in what to do with that
low. So this retrograde west and away from the area into next
week has medium confidence. Overall the low brushes the western
side of the state Saturday into Sunday, bring some shower
chances to the Cascades Saturday night into Sunday. Thereafter
the area dries out and begins to warm up heading into the new
work week. Ensembles show about about 70-90% chance of pushing
into the 90s and and about a 40-60% chance of reaching near 100
over the deeper basin heading into Tuesday and Wednesday of next
week. HeaRisk rises toward the elevated range again. Summer is
not over. /Solveig


&&

.AVIATION...
12Z TAFS: VFR conditions will prevail. The threat of rain lifts
northward Thursday afternoon, but some pop-up showers or
isolated t-storms are possible in the afternoon before drying
out from the south in the evening. KEAT has a 30% chance of
TSRA from 19-00z this afternoon. Elsewhere probabilities
are below 15%.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in continued VFR conditions at most TAF sites. Low confidence
for thunderstorms impacting airport terminals.

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

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:/weather.gov/otx/avndashboard

&&

.Preliminary Point Temps/PoPs...
Spokane        81  58  88  59  92  60 /  40  10  10   0   0   0
Coeur d`Alene  79  60  86  59  91  61 /  40  20  10  10   0   0
Pullman        80  53  87  54  89  55 /  40  10   0   0   0   0
Lewiston       87  64  93  64  96  66 /  30   0   0   0   0   0
Colville       84  51  88  49  91  51 /  20  30  20  10   0   0
Sandpoint      79  55  84  54  89  55 /  30  30  30  10   0   0
Kellogg        74  60  83  61  88  63 /  60  30  30  10   0   0
Moses Lake     88  60  92  60  95  62 /  30  10   0   0   0  10
Wenatchee      87  67  92  68  93  68 /  50  20  10   0  10  20
Omak           86  63  91  63  93  64 /  50  20  20  10   0  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Flood Watch from 11 AM PDT this morning through this evening
     for Central Chelan County-Okanogan Highlands-Okanogan
     Valley-Wenatchee Area-Western Chelan County-Western
     Okanogan County.
ID...Air Quality Alert until 11 AM PDT this morning for Central
     Panhandle Mountains-Idaho Palouse-Lewis and Southern Nez
     Perce Counties-Lewiston Area.

&&

$$