238
FXUS66 KOTX 281245
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
545 AM PDT Mon Jul 28 2025

.KEY MESSAGES...

- Temperatures warming into the 90s to 100s next week with
  widespread Moderate and localized Major HeatRisk Tuesday and
  Wednesday.

- 10-20 percent chance of thunderstorms Wednesday then 20-40
  percent chance Thursday. 10-30 percent chance lingers over
  the northern mountains and ID Panhandle Friday.

&&

.SYNOPSIS...
Temperatures will trend warmer through the early week with highs
in 90s and low 100s for Tuesday and Wednesday. There are
increasing chances for afternoon and evening thunderstorms by
the middle to end of next week.

&&

.DISCUSSION...

Morning update sent earlier to include thunderstorms for SE WA
and the lower Idaho Panhandle. Well defined midlevel circulation
and unstable environment has been very effective at high based
thunderstorms with scattered lightning strikes and possibly some
small hail.


Monday through Wednesday: A ridge beginning to build in western
Canada will promote a warming trend through much of the work week.
Temperatures will be at their hottest on Tuesday and Wednesday, with
high 90s to low 100s anticipated throughout much of the area. Low
temperatures these nights will be in the mid 60s, which could create
some problems for people prone to heat-related illnesses without
adequate cooling. Widespread moderate to local major HeatRisk is
anticipated. This ridge strengthening will also provide a transition
from southwesterly flow to southerly flow. As this southerly flow
brings in warmer, moister air, thunderstorm potential increases. The
GFE has surface-based CAPE values rising to 200-500 J/kg for these
days. Thunderstorm coverage is limited to far southeastern and
northeastern Washington, and the northern Idaho Panhandle, where NBM
probabilities show a 5-10 percent chance of thunder on these
evenings.

Wednesday evening through Sunday: Lower heights and moisture forming
over California will result in a more robust surge of warmth and
moisture Wednesday through Friday. Additionally, on Thursday, as
heights down in the southwest lower further, a shortwave will move
through the area, providing a boost in lift as well. As of right
now, NBM thunder probabilities increase from 5-10 percent on Tuesday
to 10 to 15 on Wednesday, and further to 15 to 25 percent on
Thursday and Friday afternoon. Thunderstorm coverage also increases,
with much of the forecast area showing chances for thunder. Surface-
based CAPE also jumps from 200-500 J/kg on Wednesday to 500-1000
J/kg on Thursday and Friday, with localized areas of 1000-1500 J/kg
in northeastern Washington and in the northern Idaho Panhandle. This
will create a very favorable environment for thunderstorms, and with
long range models such as the ECMWF and GFS ensembles showing PWATS
near 150 percent of normal on Thursday night, indicates these will
be wet thunderstorms. With wet thunderstorms comes higher chances of
heavy rainfall rates within cores in addition to lightning and
strong outflow wind gusts. This could result in potential flood
issues, particularly within burn scars. With medium-range models
favoring thunderstorm chances, a very close eye will be kept on this
event as it nears, particularly as short-range CAMs become
available. /AS

&&

.AVIATION...
12Z TAFS: Through 17z, main concern will be cluster of thunderstorms
tracking NE across the lower Idaho Panhandle. Currently between
LWS-PUW and will be tracking toward MLP around 15-16z.
There are cumulus buildups starting around Spokane-Cd`A as well.
Would not rule out a few cells maturing into showers or even a
brief t-storm. This comes with low confidence but given the
instability noted on the 06z balloon data, it would not take
much.

Otherwise, VFR conditions will prevail with some high clouds
moving across the region. Winds will be light today with
infrequent afternoon gusts of 15 mph. After 22z, focus will
shift toward a renewed threat for thunderstorms between NE
Oregon and W Montana with 10-20% chance to skirt Lewiston
01-03z.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in VFR conditions for majority of the region. Low confidence in
afternoon thunderstorms impacting LWS after 00z. /sb

&&

.Preliminary Point Temps/PoPs...
Spokane        91  61  95  63  96  65 /   0   0   0   0   0  10
Coeur d`Alene  91  60  94  64  95  64 /  10   0   0  10   0  20
Pullman        88  58  93  60  93  60 /  20  10   0  10  10  20
Lewiston       95  68 101  69 100  69 /  20  10   0  10  10  10
Colville       90  51  95  55  96  55 /   0   0   0   0  10  10
Sandpoint      87  55  92  59  91  60 /  10   0   0  10  10  20
Kellogg        88  63  93  67  92  67 /  20   0   0  10  10  20
Moses Lake     94  60  99  64 100  66 /   0   0   0   0   0  10
Wenatchee      93  68  98  72  99  74 /   0   0   0   0   0  10
Omak           93  63  99  65 100  66 /   0   0   0   0  10  10

&&

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

&&

$$