St. Anthony, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

154
FXUS65 KPIH 250418
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1018 PM MDT Sun May 24 2026

.KEY MESSAGES...

- Gusty Holiday Weekend Storms: Scattered showers and
  thunderstorms this afternoon and evening are producing erratic
  outflow gusts between 35 and 50 mph.

- Peak Warmth Tomorrow: Memorial Day will bring the warmest
  temperatures of the stretch, with lower elevations climbing
  into the mid-to-upper 80s alongside another round of gusty
  thunderstorm winds.

- Extended Mid-Week Unsettled Pattern: The warm holiday regime
  breaks down Tuesday as a closed low parks itself near Lake
  Tahoe, kicking off a prolonged stretch of daily storm chances,
  breezy conditions, and cooler temperatures through the end of
  May.

&&

.DISCUSSION...
Issued at 142 PM MDT Sun May 24 2026

Afternoon satellite imagery captures modest cumulus development
flanking the northern and southern edges of our forecast area.
Regional radars and surface observations have already lit up
with scattered showers and thunderstorms, many of which are
generating robust, erratic outflow wind gusts between 35 and 50
mph. High-resolution convective models (CAMs) keep this active
regime in place through the remainder of the afternoon and
evening hours. Temperatures are currently responding well to the
holiday warmth, sitting comfortably in the upper 70s to lower
80s across the lower valleys.

Expect a near-repeat performancebut with a bit more heat and
convective wind potentialfor Memorial Day. Lower elevations
will see temperatures peak tomorrow afternoon in the mid-to-
upper 80s. This added heating will drive another round of
afternoon shower and thunderstorm activity. CAMs are
particularly aggressive regarding wind potential tomorrow; the
latest 12Z HREF guidance highlights a 70% to 90% probability of
wind gusts exceeding 35 mph, with the highest risk localized
over the central mountains.

The warm and tranquil pattern completely breaks down on Tuesday
as a potent closed low pressure system drops into the western
U.S. and meanders into the Great Basin. Rather than sweeping
quickly through the region, long-range guidance tracks this
feature to park itself near Lake Tahoe through the middle and
latter half of the week, keeping the regional weather highly
volatile. While minor model discrepancies persist regarding the
precise orientation and day-to-day wobble of this low, the
overarching signal is overwhelmingly unsettled. Consequently, we
will see a sustained cooling trend, with afternoon highs
dropping back down to seasonal averages in the 60s and 70s. This
stagnant synoptic setup ensures that daily rounds of showers and
thunderstorms will return to close out the month of May,
accompanied by breezy intervals depending on exactly how the
core of the low tracks.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1013 PM MDT Sun May 24 2026

Showers and storms have diminished this evening and winds have
weakened and will weaken more becoming light and variable
during the overnight hours. Showers and thunderstorms tomorrow
afternoon will work through the region from south to north. HREF
probability of thunder is 30 to 40 percent at KPIH and KIDA
with 40 to 50 at KBYI, 50 to 60 at KSUN, and 60 to 70 at KDIJ.
Therefore, have included PROB30s at all terminals for
thunderstorm chances beginning at or after 19z. Outside of
showers and storms, winds will gust to around 20 kts. Showers
and thunderstorms will diminish in the early evening with winds
dropping off.

&&

.FIRE WEATHER...
Issued at 1249 AM MDT Sun May 24 2026

Warmer weather continues through Memorial Day, with some light
showers/sprinkles and a few thunderstorms. Best chance for any
virga and thunderstorms today will be across Zones 422 and 475
in the central mountains, 427, 411, and 413. There is 30-70%
chance for gusts over 35 mph especially south of the Snake
River, with higher end gusts reaching 45 mph. On Monday, the
better chance of development shifts to the central mountains,
although isolated showers and storms are possible elsewhere. The
potential for strong gusts increases tomorrow with a corridor of
50-90% chance of gusts over 35 mph across the central mountains
south across the Magic Valley (425), with peak gusts easily
exceeding 50 mph. There chance elsewhere is still elevated at
30-50%. There has been a shift in the pattern for midweek, as
the low ends up potentially parked over the Sierras for a couple
of days. The main impact will be to keep temperatures warmer,
although not quite as warm as today and Monday. Moisture
continues to stream north which will keep a decent shot at
wetting rains along with thunderstorms in the forecast. The low
appears to finally shift across Idaho Thursday and Friday.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...McKaughan
AVIATION...
FIRE WEATHER...Keyes