241
FXUS65 KPIH 242214
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
414 PM MDT Fri Jul 24 2026

.KEY MESSAGES...

- Dangerous Heat & Expanding Advisories: A Heat Advisory remains
  active through Saturday across lower elevations, where
  temperatures are reaching the mid-to-upper 90s with isolated
  100F readings possible in the lower Snake Plain and Magic
  Valley.

- Daily Afternoon Showers & Storms: Persistent southwest flow
  aloft will tap into Pacific moisture, triggering isolated to
  scattered afternoon and evening showers and thunderstorms
  today and Saturday. Storms will favor a mix of wet and dry
  characteristics.

- Persistent Pattern Next Week: An anchored Four Corners ridge
  will lock in above-normal heat through all of next week,
  keeping lower-elevation highs in the mid-to-upper 90s and
  likely necessitating additional heat headlines.

&&

.DISCUSSION...
Issued at 145 PM MDT Fri Jul 24 2026

Summer heat paired with daily rounds of afternoon and evening
showers and thunderstorms will remain the dominant weather
narrative through the weekend and into next week. A Heat
Advisory remains in effect today for lower-elevation zones.
Ambient temperatures have already surged well into the 90s this
afternoon, and a few isolated triple-digit readings remain
possible across the lower Snake Plain and Magic Valley before
peak heating subsides. With Saturday forecast to produce a near-
identical thermal profile, the Heat Advisory was pushed to cover
Saturday as well.

High-resolution convective-allowing models (CAMs) continue to
show isolated to scattered showers and thunderstorms developing
during the afternoon and evening hours today and again on
Saturday. This activity is driven by persistent southwesterly
flow aloft, which continues to transport sub-tropical Pacific
moisture into the Intermountain West. Forecast soundings
indicate that thermodynamic profiles will remain supportive of a
mix of both wet and dry thunderstorms through the period as
southwesterly flow lingers into mid-week. The National Blend of
Models (NBM) continues to struggle with capturing the diurnal
cycle of these terrain-driven convective pops in the medium
range. Consequently, expect baseline rain chances to be nudged
upward as individual forecast days shift into the higher-
resolution short-term window over the days ahead.

Looking further ahead, the synoptic pattern remains heavily
weighted toward above-normal heat across the region. The
persistent Four Corners high-pressure ridge will remain firmly
anchored through all of next week. This configuration will
maintain widespread lower-elevation highs in the mid-to-upper
90s through the entire 7-day period, making additional heat-
related headlines very likely as the pattern unfolds.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 413 PM MDT Fri Jul 24 2026

Scattered thunderstorms will largely diminish in coverage this
evening. Until then, potential for gusty winds and brief heavy
downpours under these storms. Most sites have a 30% probability
of a storm on station. SUN looks like the odds are lower
probably less than 20% so decided to remove mention there.
Keeping vicinity showers at most sites overnight. These
monsoonal pushes often fail to completely shut off after sunset.
Expect another round of storms tomorrow most likely affecting
most sites again with SUN looking like the most unlikely.

&&

.FIRE WEATHER...
Issued at 145 PM MDT Fri Jul 24 2026

RED FLAG WARNING for Fire Weather Zone 427 (South Hills) continues
until 9 PM MDT this evening for scattered thunderstorms. ANOTHER RED
FLAG WARNING will be in effect from 1 PM to 9 PM on Saturday. Both
of these RED FLAG WARNINGS are for scattered thunderstorm activity.
Monsoonal moisture continues to make its way into Eastern Idaho
today and tomorrow with isolated to scattered storms throughout the
South Hills, eastern Magic Valley, Snake River Plain, and Eastern
Highlands. Our short-range models are in disagreement on exactly
where these storms will be and how much coverage we will actually
see, but there is best consensus on FWZ 427 today. Most of our
Isolated storms popping up on radar so far are generally south of I-
84/86 with storms expected to move northeast. Storms today will be
capable of producing gusts of 50 to 60 mph with the SPC now
outlining much of our area in a "Marginal" risk for severe weather.

On Saturday, models show a line of scattered storms developing in
the afternoon, but disagree on the placement of said line. The NAM
sets up the line through FWZ 427 and 410 while the HRRR sets it up
through FWZ 427 and 413. Given the lack of confidence on where
exactly the line will be, the RED FLAG WARNING covers all 3 fire
weather zones for Saturday afternoon.

Also on Saturday, we will be very near RED FLAG criteria up in the
Central Mountains in FWZ 475 and 576. At this point, it looks like
RHs will be around 20 percent with wind gusts of 20 to 30 mph.
Sunday looks a bit drier and still breezy, so perhaps the RFW will
be needed on Sunday for those two zones. We remain breezy in the
Snake River Plain on Sunday, too, with gusts of 20 to 30 mph and RHs
of 10 to 20 percent.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM MDT Saturday for IDZ051>057.
Red Flag Warning from 1 PM to 9 PM MDT Saturday for IDZ410-413-
427.
Red Flag Warning until 9 PM MDT this evening for IDZ427.

&&

$$

DISCUSSION...McKaughan
AVIATION...13
FIRE WEATHER...AMM