905
FXUS65 KPIH 281001
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
401 AM MDT Tue Jul 28 2026

.KEY MESSAGES...

- Monsoon moisture will keep showers and storms around through
  Wednesday, MAYBE Thursday

- Hotter temperatures and very dry conditions return heading  into
  the weekend, including HeatRisk impacts

- Critical to near-criticial fire weather conditions expected
  for the next several days

- Wildfire smoke will continue to produce poor air quality
  especially in areas closer to central and western Idaho

&&

.DISCUSSION...
Issued at 1219 AM MDT Tue Jul 28 2026

As expected, we are seeing a break in monsoon-related showers and
storms early today. That will allow us to be a bit warmer today, and
seeing increased instability this afternoon. Of course, smoke will
also play a role in this. The latest models keep most of the
smoke across areas closer to central and western Idaho, but do
occasionally show it drifting into eastern Idaho a bit at times.
Where the smoke remains more dense, this will limit temperatures
and possibly limited instability. By afternoon and evening, we
are expecting two main areas for thunderstorm development.
Isolated storms are expected to form from around Mackay through
Gilmore Summit through Island Park. There is a 10-40% chance for
gusts over 35 mph, peaking in the 40-50 mph range. Rainfall with
these storms will remain fairly limited. The other area will be
extend across higher terrain south of the Snake River, with some
bleedover possible into the Magic Valley and Snake
Plain...especially along any outflow boundaries that form. These
storms may produce some decent downpours, although total
rainfall will not amount to much, and also higher possibilities
of wind over 35 mph. There is a 50-90% chance for those types
of gusts, peaking in the 40-55 mph range. For tonight, we will
see monsoon moisture continue to stream across central and
eastern Idaho. We do keep a mention of isolated light
showers/virga overnight. We wouldn`t be shocked to see a few
lightning strikes out of that. For tomorrow, showers and storms
will make a resurgence across most of central and eastern Idaho.
Current probabilities for gusts over 35 mph are at 30-80%, but
will be highly dependent on where we see sunshine later in the
day. This may be another situation where morning cloud cover and
smoke, may quell the amount of instability we see.

Starting Thursday, hotter and drier conditions will take hold
through the weekend. There may be just enough lingering moisture
Thursday afternoon for a few storms to fire over higher terrain,
but at the moment that chance is less than 15%. We may need to
increase that chance in later forecast updates. Otherwise,
temperatures peak Friday and Saturday in the mid 90s to mid 100s
across the area. With warm overnight lows, this will quickly
produce HeatRisk impacts especially to people sensitive to heat
or do not have the ability to stay cool and hydrated. There will
be a pattern change heading into next week it appears. Low
pressure to the north will push the ridge back to our south,
with will knock temperatures back 10-15 degrees, but still AT OR
JUST ABOVE AVERAGE. The difference here is that the flow will
keep monsoon moisture to our south as the flow is more from the
west vs southwest. Expect a continuation of very dry conditions
across the board even with the pattern change.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 400 AM MDT Tue Jul 28 2026

Smoke has thinned out farther up the Snake Plain at PIH and IDA,
while staying put and bouncing around between MVFR and VFR at
SUN and BYI. The smoke will likely ebb and flow today based on
the wind pattern across the Magic Valley and Snake Plain, so we
have VFR/MVFR for smoke at times at all sites except DIJ. We
will see another round of showers and storms mid afternoon
through this evening, impacting all sites EXCEPT IDA and SUN.
We did include PROB30 for thunderstorms with gusts up to 45kts
and MVFR ceilings/visibility. Overnight, we do expect some mid
level clouds with next monsoon push. There is the potential for
a few light showers/virga and perhaps a thunderstorm, but the
chance is way too low to mention at this time.

&&

.FIRE WEATHER...
Issued at 1219 AM MDT Tue Jul 28 2026

For a multitude of reasons, we are looking for critical to
near-critical fire weather conditions for the next several days.
We do expected another round of thunderstorms later today and
into this evening. Isolated storms are expected across Zone 476
and extending along the Montana border through Zone 411. A
second area of storms will form across higher terrain across
Zones 413 and 427, extending up through the Tetons. Coverage
will be borderline scattered down south, but confidence and
coordination isn`t there to issue a RED FLAG WARNING at the
moment. Gusts over 35 mph are possible especially with storms
down south. Storms to the north will be mostly dry, with more of
a mix down south. We will also be borderline for a warning due
to winds and low humidity across the central mountains, with
gusts in the 20-30 mph range. We will be watching to see how
smoke impacts instability and temperatures today, especially
since we are seeing it thin out in some spots. One last surge
of monsoon moisture will keep showers, and may a thunderstorm or
two, around tonight...increasing during the day Wednesday.
Coverage tomorrow will be highly dependent on two things: cloud
breaks after morning cloud cover and smoke.

Starting Thursday, we are will see hotter and drier conditions
return. We may see a few dry storms over the mountains Thursday,
but it looks bone dry after that heading through the weekend and
into next week. We will see near-critical conditions Thursday
due to wind and low humidity across the mountains. Expect more
of the same Friday and Saturday. The bigger impacts those day
will likely be a return to hotter temperatures. Crews in the
mountains will be in the 70s to near 90. Valley temperatures
will be in the mid 90s to mid 100s. Look for increasing heat-
related issues during this short stretch. Cooler weather will
return starting Sunday, HOWEVER, this pattern change will not
bring back monsoon moisture it appears. This is the typical
ridge breakdown pattern, as low pressure skirting by brings the
cooler conditions, but also stronger winds and a continued very
dry airmass in place. Any monsoon push should remain to our
south as the flow turns westerly vs southwesterly.

&&

.AIR QUALITY...
Issued at 1219 AM MDT Tue Jul 28 2026

Smoke will continue to produce degraded air quality. Most of the
more dense smoke will remain across central and south-central
Idaho, closer to fires in Oregon and southwest Idaho. The smoke
has thinned out quite a bit across eastern Idaho, however the
latest HRRR smoke model tries to show some smoke drifting back
to the east...when we see some mixing after winds shifting back
to the west and southwest. AIR QUALITY ALERTS from Idaho DEQ
remain in effect, for now, through Wednesday.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Air Quality Alert until 3 PM MDT Wednesday for IDZ051>058-
062>075.

&&

$$

DISCUSSION...Keyes
AVIATION...Keyes
FIRE WEATHER...Keyes
AIR QUALITY...Keyes