459
FXUS66 KOTX 011100
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
400 AM PDT Fri Aug 1 2025

.KEY MESSAGES...

- Scattered, wet thunderstorms Friday. Heavy rainfall, small hail,
  gusty winds and lightning main threats.

&&

.SYNOPSIS...
Scattered showers and thunderstorms Friday will be similar to
Thursday. The main threat will be flash flooding on recent burn
scars. Showers and cooler weather expected through the start of
next week.

&&

.DISCUSSION...
Today and tomorrow: Expecting another round of thunderstorm
development starting late Friday morning in the INW as a weak wave
moves through the region. With weak to no capping inversion in place
tomorrow, storms will quickly fire with a bit of heating. With PWATs
up to 200% of normal later today, I issued another flash flood watch
for the burn scars in Chelan, Okanogan, Ferry, and Stevens Counties.
The CAPE concentration will be a bit lower in the storms today, so I
did not issue another red flag warning for lightning. With that and
the even higher PWATs, the thunderstorm cores will be very wet. The
threat for strong outflow winds is lower with these factors in mind.
There is still the possibility for new fire starts outside of the
thunderstorm cores. Temperatures today will reach into the mid 80s
to mid 90s. Thunderstorm coverage Saturday looks lower as the best
moisture is confined to northeast Washington and north Idaho.

Sunday through Friday: Sunday looks much drier in the INW as a
transient shortwave ridge builds ahead of another trough developing
offshore. Temperatures will still be mild in the 80s and 90s with
breezy afternoon winds. This trough quickly moves inland Monday
bringing more chances for showers and weak thunderstorms to the
region. Temperatures will be cooler Monday in the 70s and 80s.
Temperatures start to rebound Tuesday into the 80s as this trough
shifts into northwest MT and a weak ridge builds. The mid to late
week period will feature a slow warming trend back towards the 80s
and 90s with unsettled conditions in the mountains. There are hints
of the desert southwest ridge retrograding northwest in the 9-14 day
range in the ensembles. If that is the case, a long lasting heat
wave could happen in mid August. DB


&&

.AVIATION...
12Z TAFS: Scattered light showers are drifting around the area
this morning but lightning activity has been minimal with
1-2 strikes per hour. On Friday, surface heating will initiate
convection over much of north- Central WA starting as early as
19z and continuing into early evening. A second area of
convection will occur just south of Pullman- Lewiston initially
then expand toward these terminals into the later afternoon.
Northeastern WA and North Idaho are expected to experience a
period of convection as well but more stable air may delay start
time until later in the day or evening generally after 22z. Any
storms will bring a potential for gusty and erratic wind gusts
near 30 mph, frequent lightning, small hail, and heavy rainfall
with local MVFR visibilities.


FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is
moderate to high confidence for widely scattered wet
thunderstorms across the northern counties of WA and ID where
HREF 4hour prob thunder are 60-80%. Similar probs exist from NE
Oregon to Lewis County, Idaho just south of LWS.  Uncertainty
comes with how far south cells will develop this afternoon
into the Basin and timing. Some hi-res models have cells
developing as early as 19-21z while others are later in the day
closer to 22-01z. This applies for Spokane-Cd`A and portions
of N ID which could too stable early in the day and experience
increased activity closer to 00z. /sb

&&

.Preliminary Point Temps/PoPs...
Spokane        88  62  90  60  87  59 /  40  30  20  10   0  20
Coeur d`Alene  85  63  87  59  88  59 /  40  30  20  10   0  20
Pullman        83  56  86  53  84  54 /  40  30  10   0  10  30
Lewiston       90  68  95  65  93  66 /  50  30  10   0  10  40
Colville       89  53  89  50  88  49 /  50  50  30  10  10  10
Sandpoint      84  58  82  55  86  53 /  50  50  40  10  10  10
Kellogg        82  63  83  61  84  61 /  50  40  30  10  10  20
Moses Lake     92  62  94  57  90  58 /  10  10   0   0   0  20
Wenatchee      92  66  93  65  89  64 /  30  20   0   0   0  10
Omak           92  63  94  62  92  62 /  40  40  10  10  10  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Flash Flood Watch from 11 AM PDT this morning through this
     evening for Central Chelan County-Northeast Mountains-
     Okanogan Highlands-Okanogan Valley-Wenatchee Area-Western
     Chelan County-Western Okanogan County.
ID...None.

&&

$$