383
FXUS65 KPIH 102013
AFDPIH

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

.KEY MESSAGES...

- Red Flag Warnings for the Central Mountains and the Snake
  River plain/Shoshone region Monday afternoon into early
  evening due to low relative humidity and breezy winds.

- Very small chance for an isolated (virga) shower or storm
  Monday afternoon, mainly in the South Hills.

- Wildfire smoke will continue to impact the area on and off for
  the next few days. Expect improvement and the air quality
  advisory for Custer County has expired.

- 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 /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1138 AM MDT Mon Aug 10 2026

Main impact today is going to be 20 to 25 knot wind gusts which
are in TAFs at SUN, IDA, PIH and DIJ after 18Z this afternoon
through about 03Z when they die down. Do not think BYI will gust
much more than 15 knots and do not have gusts in TAFS but mainly
a lower probability than the other three sites. Will remain VFR
and do not have smoke visibility restrictions in this set of
TAFs, but not high confidence in that.

&&

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

Near-critical to critical fire weather conditions continue today due
to the combination of low minimum RH values and gusty winds. RED
FLAG WARNINGS are in effect today for Fire Weather Zones 410, 425,
475, and 476, where critically low RH values and wind gusts 25 to 35
mph are anticipated. We also expect isolated pockets of Red Flag
conditions to materialize elsewhere, as well, but not widespread
enough for RFW issuance. Winds will decrease tomorrow and
we therefore do not anticipate any RFWs for tomorrow.

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...
Red Flag Warning until 9 PM MDT this evening for IDZ410-425-
475-476.

&&

$$

DISCUSSION...GK
AVIATION...GK
FIRE WEATHER...Cropp