624
FXUS66 KOTX 220728
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1228 AM PDT Wed Jul 22 2026

.KEY MESSAGES...

- Very warm through Thursday with high temperatures in the upper
  90s to low 100s. Widespread moderate and major HeatRisk.

- Isolated thunderstorms Thursday morning and again in the
  afternoon may result in new fire starts and gusty outflow
  winds.

- Critical fire weather conditions Friday and Saturday
  afternoons due to low relative humidity and winds. Any new or
  ongoing wildfires will be capable of spreading rapidly.

&&

.SYNOPSIS...
Hot temperatures expected through Thursday. Smoke from local
wildfires will result in hazy skies and may keep high
temperatures cooler than currently forecasted. Increasing
moisture on Thursday may result in isolated thunderstorms
Thursday morning and again Thursday afternoon. Dry and breezy
winds Friday and Saturday will result in critical fire weather
conditions.

&&

.DISCUSSION...
Wednesday: An amplified upper-level ridge extends from the
desert southwest into the Inland Northwest while a closed low
pressure system moves northward offshore the west coast.
Southerly flow aloft will maintain a steady stream of monsoonal
moisture into the region, resulting in periods of cloud cover.
850 mb temperatures are forecast to climb to around 27-29C,
supporting widespread surface high temperatures in the upper 90s
to lower 100s. There is uncertainty in the exact temperature
forecast due to smoke from local fires in Washington and Oregon.
Light winds will allow smoke to accumulate near active fires,
likely blocking afternoon solar radiation and locally limiting
the degree of warming compared to the current forecast.

Thursday through Saturday: A critical fire weather pattern will
evolve as the offshore upper low approaches the Pacific
Northwest and a weak embedded shortwave moves through the
region. Continued monsoonal moisture advection will result in
elevated instability (50- 100 J/KG of 700-300mb MUCAPE),
bringing a 10-15% chance of thunderstorms as early as late
Wednesday night into Thursday morning across the central WA
Cascades. Instability transitions to surface based by Thursday
afternoon, supporting a continued 12-25% chance of thunderstorms
across the Cascades into the Okanogan Highlands, far northeast
Washington and north Idaho, southeast Washington, and the
southern Idaho Panhandle. Very hot conditions will persist into
Thursday with model soundings showing DCAPE values exceeding
1000 J/kg in the afternoon. This will create a favorable
environment for strong, localized downdraft wind gusts with any
shower or thunderstorm activity.

By Friday into Saturday, an upper-level trough digs off the
Pacific Northwest coast from the Gulf of Alaska, pushing the
initial offshore low eastward, driving a dry cold front across
the region. An increasing cross-Cascade pressure gradient will
bring breezy winds through the Cascade gaps beginning Thursday,
followed by widespread breezier conditions on Friday with better
vertical mixing. The most impactful period is currently
forecasted for Saturday as an 85-96 knot jet streak moves into
the Inland Northwest ahead of the upper-level trough. Stronger
winds at 850mb and 700mb (around 25 mph and 32 mph,
respectively) combined with a +8-10mb PDX- GEG surface pressure
gradient will support widespread gusty winds with southwest wind
gusts 25 to 40 MPH. On Friday the NBM indicates a 30-70% chance
from the Okanogan Valley, Waterville Plateau, and the upper
Columbia Basin into the West Plains for sustained wind speeds
exceeding 15 mph combined with minimum relative humidity below
20%. Some cooling is expected on Saturday, raising the afternoon
relative humidity, with a 40-60% chance for the same
combination across the Inland Northwest. Despite the wetter RHs,
the winds are expected to be stronger than Friday, negating any
benefit of the cooler temperatures. The timeline of very hot
temperatures, lightning potential, and subsequent dry, breezy
frontal passage presents a high impact fire weather scenario for
the Inland Northwest Thursday through Saturday.

Sunday through Tuesday: Ensembles are in broad agreement for
the next upper-level trough to move onshore on Sunday, bringing
cooler conditions and a chance for light preciptiation along the
Cascade crest. Uncertainty in the synoptic pattern increases
Monday and Tuesday with around 40% of ensembles showing the
upper-level ridge rebounding with a return of heat. The other
60% show degrees of troughing, which would keep temperatures
cooler into early next week. /vmt

&&

.AVIATION...
12Z TAFS: High pressure and light winds will allow smoke and
haze to continue across the Inland Northwest. Smoke may
intermittently reduce visibilities to MVFR across TAF sites.
Some slightly higher wind gusts are expected toward afternoon
to evening near the Okanogan Valley and near the Cascades,
including KEAT/KOMK with gusts up to 15kts. Otherwise mid and
high clouds will continue to stream into the region from the
southwest.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence in the visibility forecast at the TAF sites.

-----------------------
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  97  66  95  63 /   0   0  20   0   0   0
Coeur d`Alene  95  67  95  66  94  63 /   0   0  20   0   0   0
Pullman        91  61  91  58  91  57 /   0   0  10  10   0   0
Lewiston       98  70  99  68 100  67 /   0   0  20  20   0   0
Colville       97  62  96  61  95  58 /   0   0  20  10   0   0
Sandpoint      94  64  95  63  93  60 /   0   0  20  10   0   0
Kellogg        91  64  92  62  90  60 /   0   0  20  10   0   0
Moses Lake     99  68  98  64  98  63 /   0   0  20   0   0   0
Wenatchee     100  77  98  69  97  68 /   0  10  20   0   0   0
Omak          101  72  99  68  98  63 /   0   0  20  20   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Heat Advisory until 9 PM PDT Thursday 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 Chelan County-Western Okanogan County.
     Air Quality Alert until 9 AM PDT this morning for Moses Lake
     Area-Northeast Mountains-Okanogan Highlands-Okanogan
     Valley-Spokane Area-Upper Columbia Basin-Washington
     Palouse-Waterville Plateau-Western Okanogan County.
ID...Heat Advisory until 9 PM PDT Thursday for Coeur d`Alene Area-
     Lewis and Southern Nez Perce Counties-Lewiston Area-
     Northern Panhandle.

&&

$$