117
FXUS66 KOTX 211833
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1133 AM PDT Fri Aug 21 2026

.KEY MESSAGES...

- A Heat Advisory has been issued for Friday afternoon and
  evening due to very warm temperatures and widespread Major
  HeatRisk.

- Saturday system brings increased chances for showers,
  thunderstorms, and gusty winds. This will lead to critical
  fire weather conditions across the Inland Northwest.

- Patchy blowing dust is possible Saturday in the Western
  Columbia Basin.

&&

.SYNOPSIS...
Temperatures will be very warm Friday with increasing mid and
high level clouds. A pattern change Friday night into Saturday
will bring unsettled conditions with chances for showers,
thunderstorms, and gusty winds. Sunday will remain breezy and
dry, but cooler. Temperatures will warm again at the start of
next week with breezy conditions returning by the middle of next
week.

&&

.DISCUSSION...
Friday: The ridge axis that was over the Inland NW on Thursday
will begin to shift eastward into the Idaho Panhandle as a deep
low wobbles toward the WA Coast. This will allow an influx of
mid and high level moisture to drift northward into the region
bringing filtered sunshine. Temperatures will remain warm
topping out in the mid to upper 90s with with some areas
potentially reaching the century mark. The air mass will support
warmer temperatures than Thursday but the presence of high
clouds does add a decent amount of uncertainty in exactly how
warm conditions will be. Winds will be light with a moderate
amount of terrain influence. Areas which experience northeast to
east terrain-driven winds could see periods of breezy
conditions near 10 mph due to the alignment with the general
winds as they begin to be influenced by the approaching low
pressure system.

Friday night into Saturday night: The low continues to drift
toward the coast Friday night and into Western WA on Saturday.
A weak impulse moving out ahead of the low will come through the
region Friday night bringing an increased risk for elevated
showers or sprinkles. Some hi-res models indicate a small threat
(5-10% chance) for a few lightning strikes Friday night, but
this comes with very low confidence due to 850-300mb CAPE only
on the order of 50-100 J/kg and very weak forcing. HREF also
advertises near zero probabilities for lightning Friday night,
and the HREF model has done well so far over the course of the
summer. HRRR on the other hand has some lightning threat Friday
night as do a few other hi- res models, so the lightning threat
will be something to monitor given its high based nature and
little to no rainfall associated with it.

As we head into Saturday, the weather becomes a bit more dynamic
as stronger lift arrives. At this time, the way things are
starting to evolve comes in different waves. First will be the
threat for showers and thunderstorms along the Cascades Saturday
morning with some activity lingering near the Canadian border
in the afternoon. Second will be showers and thunderstorms
developing over the Idaho Panhandle and extreme southeastern WA
Saturday afternoon and continuing in different waves overnight.
Both areas have the potential for isolated strong storms with
the higher threat leaning toward the Idaho Panhandle given the
activity aligning with peak heating. Gusty outflow winds,
lightning and fire starts, and brief downpours of rain and hail
will be a concern with any cells.

In between these thunderstorm areas, the major concern will be
critical fire weather conditions from gusty winds and hot, dry
conditions. An index used for this is the hot, dry, windy index
which is showing areas of the Columbia Basin well into the 95th
percentile. There is reasonable agreement amongst the models for
a surface low to deepen over NE WA or close to the Canadian
border as the low is drifting inland initially pulling south
winds across the Western Basin and into the Okanogan Valley.
These winds then start to expand eastward while shifting to the
southwest as the low begins to track east, dragging a cold front
with it and sending cold air flooding inland. Winds across the
East Slopes will largely follow the footprints of the terrain
and come from the west/northwest. Strongest winds on Saturday
look to set up across the Western Columbia Basin and into the
Okanogan Valley where sustained speeds will be 20-25 mph with
gusts of 30-35 mph. The Spokane Area and foothills of the
northern mountains will be windy, but speeds look to be a few
mph lighter with sustained speeds of 15-20 mph and gusts to 30
mph. The strongest winds for the Eastern Basin, Palouse, L-C
Valley, and foothills of the Blue Mountains will arrive later in
the day and into the evening as the cold front presses through
and would not rule out gusts close to 35 mph when this occurs.
Overall, it looks to be a very impactful day in regard to fire
weather for new starts and wind driven fires. We will also need
to watch for blowing dust on Saturday around Moses Lake,
Ritzville, Wilbur, and Omak.

While lightning may be limited across the northern mountains
during the day on Saturday as the winds are blowing, the low
will move through northern WA and into southern BC Saturday
night into Sunday. This will keep the threat for showers and
thunderstorms going well into the evening and overnight hours
while winds remain elevated region-wide. The main threat for
thunderstorms on Sunday will be in the morning with the system
departing to the east and breezy winds becoming the most
impactful weather through the day while temperatures cool back
into the 80s.

Monday through Friday: The pattern is setting up to be quite a
roller coaster and has plenty of support from the ensemble
suites. High pressure moves in Monday and Tuesday promoting a
warming and drying trend. This is quickly interrupted by another
robust shortwave Wednesday. The exact depth and track of this
through the NW comes with some uncertainty, but pattern
recognition would suggest another bout of windy conditions and
possibly some thunderstorms. The pattern repeats itself again
with ridging Thursday and Friday and the next system arriving Friday
into Saturday. We are not seeing a lot of signs for appreciable
rainfall with these systems indicating fire weather concerns
will remain elevated or higher as we navigate the end of August.
/sb

&&

.AVIATION...
18Z TAFs: VFR conditions are expected to continue through the
TAF period. Winds will be less than 10kts for all terminals
except COE, which will see these winds decrease over the next
few hours. Smoke from local wildfires may cause reductions in
visibility, especially for EAT. Smoke models remain pessimistic
and show EAT remaining at or below 6SM through the TAF period.
For all other terminals, smoke models show visibilities are
expected to remain VFR at 6SM or greater.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in light winds and VFR conditions for all TAF sites. Moderate
confidence in continued lowered visibilities at EAT due to smoke
from the Little Giant Fire. /AS

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

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        97  66  94  59  81  54 /   0  10   0  30   0   0
Coeur d`Alene  98  67  95  60  80  53 /   0  10   0  40  10   0
Pullman        98  60  90  51  78  46 /   0  20  10  30   0   0
Lewiston      103  72  98  64  86  59 /   0  20  10  20   0   0
Colville       96  58  93  52  80  45 /   0  10  10  30  20   0
Sandpoint      94  62  92  55  79  47 /   0  10  10  40  10   0
Kellogg        96  63  92  54  77  52 /   0  10  10  40  10   0
Moses Lake     99  68  94  55  85  53 /   0  10  10  10   0   0
Wenatchee      97  75  92  62  83  61 /   0  10  30   0   0   0
Omak           98  71  95  59  84  55 /   0  10  20  20  10   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...

WA...Heat Advisory from 11 AM this morning to 10 PM PDT this
evening for Central Chelan County-Lower Garfield and Asotin
Counties-Moses Lake Area-Northeast Blue Mountains-Northeast
Mountains-Okanogan Highlands-Okanogan Valley-Spokane Area-Upper
Columbia Basin-Washington Palouse-Waterville Plateau-Wenatchee
Area-Western Okanogan County.

Fire Weather Watch from Saturday afternoon through Saturday
evening for Colville Reservation (Zone 702)-Eastern Columbia
Basin-Palouse-Spokane Area (Zone 708)-Foothills of Central
Washington Cascades (Zone 705)-Foothills of Northeast
Washington (Zone 701)-Lower Palouse-Snake River (Zone
709)-Waterville Plateau (Zone 706)-Western Columbia Basin (Zone
707).

Air Quality Alert until further notice for Chelan, Douglas,
Ferry, Grant, and Okanogan Counties.

Fire Weather Watch from Saturday morning through Sunday morning
for East Portion of North Cascades National Park/Lake Chelan
National Recreation Area (Zone 697)-East Washington Central
Cascades (Zone 696)-East Washington North Cascades (Zone
698)-Methow Valley (Zone 704)-Okanogan Highlands and Kettle
Mountains (Zone 699)-Okanogan Valley (Zone 703).

ID...Heat Advisory from 11 AM this morning to 10 PM PDT this
evening for Central Panhandle Mountains-Coeur d`Alene Area-Idaho
Palouse-Lewis and Southern Nez Perce Counties-Lewiston Area-
Northern Panhandle.

Fire Weather Watch from Saturday afternoon through Sunday
morning for Northern and Central Idaho Panhandle (Zone 101).

Air Quality Alert until 3 PM PDT this afternoon for Clearwater,
Idaho, and Lewis Counties on the Nez Perce Reservation.

&&

$$