243
FXUS65 KPIH 110457
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1057 PM MDT Mon Aug 10 2026

.KEY MESSAGES...

- Near critical winds and critical relative humidity Tuesday
  afternoon/early evening.

- Very small chance for an isolated (virga) shower or storm
  Tuesday afternoon, mainly along the Utah and Wyoming borders.

- Wildfire smoke will continue to impact the area on and off for
  the next few days. Overall improvement is expected by mid-week
  into the end of the week.

- Major pattern change with widespread showers and thunderstorms
  expected Thursday into Saturday with significant cooling.

&&

.DISCUSSION...
Issued at 121 PM MDT Mon Aug 10 2026

Main impact this afternoon and evening isolated thunderstorm
development in mainly the southern mountains once again. Areas
of smoke still exist but not as significant and the air quality
advisory for Custer County has been discontinued. Hot conditions
continue through Tuesday with low elevation highs remaining in
the 90s then a significant cooling trend sets in on Wednesday.
Biggest impact in the long term is an upper level trof
approaching with strong southwesterly flow ahead of it drawing
in tons of moisture and have very high chances of precipitation
as this trof moves through Thursday as well as Friday. Will be
some potential for flash flooding especially over recent burn
scars should any of the heavier showers reach those. The chance
for showers and thunderstorms remain Saturday through next
Monday but much lesser precipitation expected. Highs in the 60s
mountains and 70s low elevations Thursday and Friday rising to
the 70s and 80s Saturday into next Monday.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1049 PM MDT Mon Aug 10 2026

Expect VFR conditions the next 24 hours for all TAF sites except
BYI and, to a lesser degree, SUN. Wildfire smoke is still in
the area. BYI and, to a lesser degree, SUN will likely see
reduced visibility bringing MVFR conditions, as they are the
farthest west and, thus, closest to the fires west of them.
There is a plume of smoke headed to BYI from the fire in
southwest Idaho. Expect SCT to BKN high clouds for all TAF sites
except SUN with moisture moving up from the south. These CIGS
will drop to mid-levels by tomorrow afternoon and continue into
tomorrow evening. Expect wind gusts to increase after 18Z once
again on Tuesday but more in the 15 to 20 knot range about 5
knots of so weaker than today`s gusts. Winds will drop off
quickly in the early evening tomorrow.

&&

.FIRE WEATHER...
Issued at 1247 PM MDT Mon Aug 10 2026

Tuesday winds will drop off slightly compared to today. Expect
near critical winds and critical relative humidity in the
afternoon/early evening.

A deepening trough along the Pacific coast will continue to flatten
the ridge of high pressure over Idaho, resulting in a gradual cool-
down through late this week under increasing clouds. Daytime highs
will return to around normal or just below by the middle of this
week, turning cooler than normal late week. While isolated storms
are forecast across the southeast highlands the next couple
afternoons, the main monsoon surge will arrive late Thursday and
continue through Saturday. This will raise humidities and provide
much-needed rain, which could be heavy at times, but also introduce
the risk of lightning. On Wednesday, we will likely need to
coordinate the next round of RFWs for scattered thunderstorms on
Thursday.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...GK
AVIATION...TW
FIRE WEATHER...Cropp/TW