298
FXUS66 KOTX 200758
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1258 AM PDT Wed Aug 20 2025

.KEY MESSAGES...

- Dry and breezy southwest winds on Wednesday with elevated fire
  weather conditions.

- Warm and dry through the weekend with widespread Moderate for
  eastern Washington and north Idaho and widespread Major
  HeatRisk for central Washington.

&&

.SYNOPSIS...
Winds will be breezy on Wednesday with elevated fire weather
conditions. Then, a persistent ridging pattern will lead to a
warming and drying trend across the region Thursday through
early next week.

&&

.DISCUSSION...
Wednesday: The Inland Northwest remains under southwesterly flow
aloft, with an upper-level ridge anchored over the central United
States and a closed low tracking across northern British Columbia.
Mid and upper level clouds are increasing across western and central
Washington as a weak mid-level front associated with the low moves
inland. This front will cross the Cascades Wednesday morning,
bringing a noticeable increase in southwest winds across eastern
Washington and north Idaho by late morning into the afternoon.
Sustained winds of 10-20 mph with gusts of 20-30 mph are expected
during this time.

Precipitation is not expected with this front, though a few
sprinkles cannot be ruled out over far northeast Washington and
north Idaho. Ahead of the front, precipitable water values will
range from 100-140% of normal, dropping to 40-80% of normal behind
it by Wednesday evening as much drier air moves in. Elevated fire
weather conditions are anticipated during the afternoon, however,
relative humidity values should remain high enough to mitigate
widespread critical conditions. That said, brief pockets of critical
fire weather are possible, particularly over the Waterville Plateau
and western Columbia Basin, where there is a 30% chance of minimum
RH below 20% and sustained winds above 15 mph between 3 PM and 7 PM.

Thursday through Tuesday: Models are in good agreement that the
upper-level low will shift east through central Canada on Thursday
as another upper-level low approaches the Alaskan Panhandle. This
pattern will allow the Four Corners high to amplify northward,
leaving the Pacific Northwest sandwiched between these two lows and
under the influence of a strengthening ridge for several days.
Heat will be the primary concern. Temperatures will trend warmer
through Saturday, with highs reaching the mid 90s to low 100s and
very little spread between the 25th and 75th percentile temperature
forecasts in the National Blend of Models (NBM) through Monday.
Moderate (orange) HeatRisk will become widespread across the Inland
Northwest by Saturday, with locally Major (red) conditions in the
Wenatchee area and L-C Valley. Little change in the ridge position
will prolong the heat into early next week, with Major HeatRisk
becoming more widespread in central Washington and pockets of
Extreme (magenta) HeatRisk around Wenatchee. Extreme HeatRisk is
rare and typically occurs when several consecutive days of hot
daytime temperatures combine with warm overnight lows (mid 60s to
low 70s). This level and duration of heat will pose a significant
danger to anyone without adequate cooling or hydration.

By Monday and Tuesday, deterministic models begin to suggest the
northward advection of monsoonal moisture as a weak weather system
approaches the PNW coast. This could bring the potential for
elevated convection, raising the risk of new fire starts. Confidence
remains low, with only a 5-10% chance of thunderstorms in the NBM at
this time. This will continue to be monitored closely in the coming
days. /vmt

&&

.AVIATION...
06Z TAFS: VFR conditions will prevail through the next 24 hours.
A weak weather system moving through will bring passing mid and
high clouds along with breezy southwest winds late Wednesday
morning through the afternoon. Gusts 15-25 knots are anticipated
for all TAF sites during this time, with the stronger push of
winds delayed until 23/00Z for KEAT.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
for conditions to remain VFR.

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

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        84  53  87  54  91  57 /   0   0   0   0   0   0
Coeur d`Alene  84  53  87  54  90  58 /   0   0   0   0   0   0
Pullman        80  51  85  51  91  53 /   0   0   0   0   0   0
Lewiston       90  61  93  60  98  63 /   0   0   0   0   0   0
Colville       85  44  86  45  90  48 /   0   0   0   0   0   0
Sandpoint      82  49  85  50  87  52 /   0   0   0   0   0   0
Kellogg        81  57  83  58  90  60 /   0   0   0   0   0   0
Moses Lake     87  52  88  55  94  59 /   0   0   0   0   0   0
Wenatchee      85  60  88  63  93  67 /   0   0   0   0   0   0
Omak           88  55  88  56  93  59 /   0   0   0   0   0   0

&&

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

&&

$$