700
FXUS66 KOTX 040904
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
204 AM PDT Mon Aug 4 2025

.KEY MESSAGES...

- Several rounds of scattered showers and isolated thunderstorms
  this week, mainly Monday and again late Wednesday into
  Thursday
- Below normal temperatures for the upcoming work week
- Dry and warmer this weekend

&&

.SYNOPSIS...
A weather system moving in today will bring scattered showers
and isolated thunderstorms mainly over the mountains, southeast
Washington, and the Idaho Panhandle. Another midweek system is
expected late Wednesday through Thursday with another round of
showers and thunderstorms. Temperatures will also cool to below
normal values for much of the upcoming work week with high
temperatures in the 70s and 80s. Warmer and dry weather is
expected for the weekend.

&&

.DISCUSSION...
Today: Water vapor satellite early this morning showed a low
tracking into SW Oregon and moving east. There is good model
agreement that this low will track south of the area into Eastern
Oregon into the Clearwaters this afternoon and evening. The CAM`s
models have backed off on the expansion of showers over more of
Eastern WA, with the best shower and thunderstorms chances today
associated with this feature expected to be over the Blue
Mountains, Camas Prairie, and southern Shoshone county.
Elsewhere, uncapped surface based CAPE of 500-1000 J/KG over the
northern mountains combined with afternoon heating will lead to
another round of showers and thunderstorms as well. The NBM
favors the highest chances (30-50%) over the North Cascades
(including the Methow Valley) east into the Oroville area,
Okanogan Highlands, and near the Canadian border. Slow moving
storms and precipitable water values running near 125-150% of
normal will lead to locally heavy downpours with thunderstorms.
This activity will diminish after sunset with the loss of
daytime heating.

Tuesday and Wednesday afternoon: The next low pressure system
tracks into British Columbia with a significant amount of mid and
high clouds spilling into the region with precipitable water
increasing to 150-180% of normal. Yet mid level westerly flow
combined with cooler temperatures and cloud cover will lead to a
more stable air mass with models showing the best chances for
showers near the Cascade crest and up near the Canadian border.

Wednesday evening through Thursday Night: The NBM continues to
show increasing chances for showers and thunderstorms across the
region, with the best chances over NE Washington and the ID
Panhandle (60-80% chance of showers and 20-40% chance of
thunderstorms). Yet the details are still unclear of the track of
the low after it punches into British Columbia on Wednesday. 45%
of the cluster solution track the low south into NE WA Thursday
afternoon producing an abundance of showers and wet thunderstorms
with wetting rains. 25% of the solutions keep the low much further
north with a mid level dry slot limiting shower coverage to mainly
the northern mountains. The other 30% provide an in-between
solution with an open trough digging south providing an increase
in showers over the region but not as widespread as the first
scenario mentioned. Long story short, there is moderate
confidence that showers will be increasing over the region, but
low confidence on precise coverage and rain amounts.

Friday through Sunday: There is growing confidence of a warming
trend as high pressure moves over the area. 20% of the clusters
hold on to the trough over the area on Friday, otherwise all the
clusters show high pressure over the area for next weekend. There
is some differences on the strength of the ridge (flat or more
amplified) leading to some uncertainty as to the amount of
warming, but confidence in warming and drying is high. Currently
the NBM for Sunday shows highs in the mid 80s to mid 90s (slightly
above normal), and then the upper 80s and 90s next Monday and
Tuesday. This warming and drying may allow recent lightning caused
fire starts in the mountains to become more active, especially if
wetting rains don`t materialize on Thursday. JW

&&

.AVIATION...
12Z TAFS: VFR conditions will continue across the region. A
passing weather system will trigger scattered showers and
isolated thunderstorms over the mountains of northern
Washington, Idaho Panhandle, and down around the Lewiston area.
The NBM shows a 30% chance of thunderstorms for KLWS, so a
PROB30 group is included from 20z-02z. Main concerns with
thunderstorms will be gusty outflow winds, with variable gusts
of 20-30 kts possible. After 02-06Z the threat of
showers/t-storms wanes throughout the region.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is high confidence for VFR conditions except under heavier
showers or thunderstorms where brief MVFR visibilities are
possible. A few showers may also slip north toward the
GEG/SFF/COE area later this afternoon and evening, but
confidence is low, at less than 15%.

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

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        82  56  83  59  80  58 /  10  10   0   0  10  40
Coeur d`Alene  81  56  83  59  79  58 /  10  10   0   0  10  40
Pullman        75  48  80  53  76  53 /  20  10   0   0  10  30
Lewiston       83  59  89  64  85  63 /  30  20   0   0  10  30
Colville       85  47  83  49  80  48 /  20  20   0   0  10  50
Sandpoint      81  53  81  54  77  55 /  20  20   0   0  10  50
Kellogg        78  57  80  59  76  59 /  30  30   0   0  10  40
Moses Lake     85  54  86  58  84  58 /   0   0   0   0  10  20
Wenatchee      86  61  86  65  83  63 /   0   0   0   0  20  20
Omak           90  58  88  61  85  59 /  30  20   0   0  10  30

&&

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

&&

$$