818
FXUS65 KPIH 231931
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
131 PM MDT Thu Jul 23 2026

.KEY MESSAGES...

- Surging Heat & Heat Advisory Friday: A building Four Corners
  ridge will push temperatures into the mid-to-upper 90s Friday
  through early next week. A Heat Advisory is in effect Friday
  for lower elevationsincluding the Snake Plain, Magic Valley,
  Arco Desert, Shoshone, and South Hills  where highs will
  reach 95F to 100F.

- Shift to Mixed Wet/Dry Storms: Drier air aloft will limit
  overall storm coverage today and Friday, favoring a mix of
  isolated wet and dry thunderstorms. Convection targets the
  Central Mountains and Continental Divide today before shifting
  toward the Utah border on Friday.

- Saturday Shortwave & Gusty Winds: A passing shortwave on
  Saturday will briefly elevate shower and thunderstorm chances
  while generating widespread wind gusts of 30 to 40 mph. This
  could lead to Red Flag Conditions for parts of eastern Idaho.

&&

.DISCUSSION...
Issued at 129 PM MDT Thu Jul 23 2026

Afternoon satellite imagery presents a stark contrast to 24
hours ago, showing mostly clear skies across eastern Idaho.
While gradual cumulus development is underway over the higher
terrain, lower elevations remain virtually cloud-free. Clear
skies coupled with an amplifying Four Corners ridge to our south
will allow significant heat to return to the region. While
afternoon highs today will remain near seasonal benchmarks in
the upper 80s to lower 90s across valley locations, temperatures
will quickly ramp up into the mid-to-upper 90s on Friday and
linger through the weekend into early next week. In response, a
Heat Advisory has been issued for Friday across lower-elevation
zonesincluding the Snake Plain, Magic Valley, Arco Desert,
Shoshone, and the South Hillswhere widespread max temperatures
of 95F to 100F appear likely.

Regarding precipitation, an intrusion of drier mid-level air
will restrict overall storm coverage over the next 48 hours,
prompting a transition back to a mix of wet and dry
thunderstorms. High-resolution convective-allowing models (CAMs)
highlight the Central Mountains and the Continental Divide as
the primary focus for isolated afternoon development today.
Convective activity is forecast to shift southward toward the
Utah border on Friday.

A passing shortwave trough will interrupt the dry-leaning
pattern on Saturday, bringing an uptick in shower and
thunderstorm potential. In addition to storm chances, the
gradient will tighten, yielding widespread afternoon wind gusts
of 30 to 40 mph across the forecast area. Behind this
disturbance, the broad ridge will maintain its grip over the
Intermountain West, keeping temperatures consistently above
normal through early next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1122 AM MDT Thu Jul 23 2026

Drier conditions today mean VFR conditions are expected at all TAF
sites through the forecast period. There is about a 20 percent
chance of an isolated shower or storm around DIJ, but confidence is
not high enough to include in the TAF at this time. Winds remain
light today and tonight, too.

&&

.FIRE WEATHER...
Issued at 129 PM MDT Thu Jul 23 2026

High pressure is building back in over the area today after
yesterday`s shortwave and monsoon moisture push. A few isolated
thunderstorms will continue this afternoon, mainly being triggered
by orographic lift off our mountains and afternoon heating. Overall,
it will be a much drier day for most, but min RHs haven`t completely
dropped from yesterday`s moisture. That will be more noticeable
beginning tomorrow with min RHs areawide of 15 to 25 percent. Winds
will be a bit breezy on Friday afternoon, too, with gusts around 20
to 25 mph. We will see near-critical fire weather conditions in
parts of the Central Mountains in the afternoon, Fire Weather Zones
475 and 476. Winds get even more breezy on Saturday and another
round of monsoon moisture looks to impact parts FWZ 410, 411, 413,
and 427. So, Saturday looks like a day we may need Red Flag Warnings
for a mix of low RHs and gusty winds 475 and 476 and a mix of wet
and dry scattered thunderstorms in 410, 411, 413, and 427, but we
will see how the next few model runs look later tonight and
tomorrow. Overall, it doesn`t look like the pattern is changing much
as we head into next week.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM to 9 PM MDT Friday for IDZ051>057.

&&

$$

DISCUSSION...McKaughan
AVIATION...AMM
FIRE WEATHER...AMM