927
FXUS65 KPIH 272346
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
546 PM MDT Mon Jul 27 2026

.KEY MESSAGES...

- Widespread smoke has infiltrated most of eastern Idaho today
  with the effect dropping high temperatures substantially. Air
  Quality Advisories have also been issued through Wednesday for
  the smoke.

- Monsoon moisture remains with a daily chance of light showers
  and thunderstorms through at least midweek

- ABOVE AVERAGE temperatures expected to return by mid week with
  extremely hot conditions expected Friday and Saturday.

- Critical to near-critical fire weather conditions in place for
  the next few days.

&&

.DISCUSSION...
Issued at 104 PM MDT Mon Jul 27 2026

Main impact today is significant smoke has moved into southeast
Idaho and dropped daytime temperatures substantially from the
previous few days. Expected to get at least a bit of clearing
Tuesday but still lack confidence in widespread 90s in low
elevations for high temperatures tomorrow. Air quality alerts
have been issued for a large portion of southeast Idaho for the
smoke present. Isolated showers and thunderstorms are expected
this evening as well as Tuesday and Wednesday in southwest flow
aloft. By Thursday upper level ridge begins to expand north and
dry conditions are in the forecast grids Thursday through next
Monday. With this extreme heat is expected to return with low
elevation highs nearing 100 again both Friday and Saturday.
Presence or non presence of smoke will be a factor in
temperatures for several days.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 541 PM MDT Mon Jul 27 2026

Smoke and haze from regional wildfires will be the biggest
impact to aviation across eastern Idaho over the next 24 hours.
Currently seeing VSBYs range from around 2-5 SM at all
terminals except KDIJ where P6SM continues. Based on latest
output from HRRR smoke model, looks like it`ll take until later
tonight to see some improvement at KIDA, KPIH, KBYI, and KSUN
where we could return to VSBYs around 5-6 SM. All that being
said, confidence is low with regard to just how much improvement
we will see. As far as precip is concerned, still some
potential for showers to impact the Snake Plain and DIJ
terminals but smoke is keeping temperatures lower and will thus
likely limit convection. Look for continued overall light winds
tomorrow afternoon with SCT to BKN mid-level clouds in the
afternoon.

&&

.FIRE WEATHER...
Issued at 142 PM MDT Mon Jul 27 2026

Monsoon moisture remains locked in through Wednesday across central
and eastern Idaho. This will keep some mention of thunderstorms
going through that point. We will continue to see more dry than wet
thunderstorms overall. For today, increasing smoke from fires in
Oregon and southwest Idaho have kept temperatures much cooler than
forecast across much of the area. This has led to more stable
conditions but areas that see just enough clearing, and thus
heating, could see some isolated tstm activity. It should remain
breezy especially over the central mountains, portions of the Arco
Desert, and Magic Valley. A RED FLAG WARNING remains in effect for
the Zone 475/476 in the central mountains, although this remains
marginal. For Tuesday, the pattern remains similar, although cloud
cover will be less overall tomorrow and smoke should improve for the
eastern half of the area based on latest model output. The main push
storms will be outside of the central mountains, although a small
corridor is possible across 475 and 476. We may also be close again
on critical fire weather threshold for wind and humidity in those
zones. Another deeper surge of moisture arrives for a better chance
of showers and storms overall into Wednesday.

By Thursday and into the weekend, the ridge shifts west and
potentially even southwest. This should cut off most, if not all, of
the monsoon moisture for a while. This will allow for very low
humidity issues and hotter temperatures to return. At the moment, we
do not have any thunderstorm chances in the forecast. With hotter
temperatures, any amount of moisture that crosses the state may
produce at least some virga if not a thunderstorm or two.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Air Quality Alert until 3 PM MDT Wednesday for IDZ051>058-
062>075.
Red Flag Warning until 9 PM MDT this evening for IDZ475-476.

&&

$$

DISCUSSION...GK
AVIATION...TW
FIRE WEATHER...McKaughan