189
FXUS65 KPIH 021203
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
603 AM MDT Wed Sep 2 2026

.KEY MESSAGES...

- Strong Winds Today: Winds will flirt with Wind Advisory and
  Lake Wind Advisory criteria this afternoon. While an advisory
  has not been issued due to the marginal and short-duration
  nature of the winds, a short-fused issuance remains possible
  if winds overperform.

- Red Flag Warning & Mountain Rain: A Red Flag Warning remains
  in effect today for Fire Zone 422 due to thunderstorm
  coverage. Meanwhile, the Central Mountains  especially around
  the Sawtooths  will see multiple rounds of precipitation
  over the next 48 hours. The rest of eastern Idaho will remain
  largely dry through Friday.

- Cool Today, Warming into Saturday: Daytime highs will be
  noticeably cooler today, holding in the 60s and 70s. A gradual
  warming trend will add 1 to 3 degrees to daily highs each day
  from Thursday into the weekend.

- Unsettled & Cool Labor Day: Confidence is increasing for a
  very unsettled Labor Day weekend as a Pacific low moves
  eastward. Expect high probabilities for precipitation and
  daytime high temperatures plummeting 10 to 15 degrees below
  seasonal normals by early next week.

&&

.DISCUSSION...
Issued at 158 AM MDT Wed Sep 2 2026

The region remains under the influence of a broad upper-level
trough in place across the Pacific Northwest. Embedded waves of
energy will continue to rotate through this upper-level pattern,
bringing waves of cloud cover and precipitation to parts of
eastern Idaho over the coming days. Early morning satellite
imagery shows the next wave of clouds and moisture positioned
across eastern Oregon, which will progress toward Idaho
throughout the morning. High-resolution convective-allowing
models (CAMs) show this feature producing multiple rounds of
precipitation across the Central Mountains  especially around
the Sawtooths  over the course of the next 48 hours, albeit
with occasional breaks. Fire Zone 422 remains under a Red Flag
Warning today due to anticipated thunderstorm coverage.

Outside of the Central Mountains, the rest of eastern Idaho
looks dry through Friday, making wind the primary operational
hazard. Winds will push Wind Advisory and Lake Wind thresholds
today. The current wind forecast has been nudged upward closer
to the NBM 90th percentile guidance, placing expected gusts
right on the cusp of advisory criteria. Given the short duration
and marginal nature of the setup, we have opted to hold off on
a formal advisory for now, though a short-fused issuance may be
needed this afternoon if winds overperform. Temperatures today
will be noticeably cooler across the region, with daytime highs
limited to the 60s and 70s.

Winds will remain breezy on Thursday and Friday, but latest
guidance suggests speeds will be a touch lower than what we
experience today. A slight warming trend will take hold during
this period, with maximum temperatures increasing by 2 to 4
degrees each day from Wednesday through the weekend.

As we move into the latter half of the Labor Day holiday
weekend, global models show the aforementioned Pacific upper low
slowly starting to make eastward progress toward Idaho. This
will allow for increased atmospheric lift and deep moisture to
push into the area on Sunday, and especially on Monday.
Precipitation chances are trending upward and look increasingly
likely for the holiday. While there is still a bit of
uncertainty regarding the exact track of the low, confidence is
increasing for a potentially unsettled Labor Day across the
forecast area. Extensive cloud cover, widespread precipitation,
and lower 500 mb heights should result in well-below-normal high
temperatures on Labor Day and through the first part of next
week, dropping 10 to 15 degrees below seasonal norms.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 557 AM MDT Wed Sep 2 2026

Models show potential for some showers and storms approaching
SUN over the next few hours. Otherwise, rest of the TAF sites
are expected to remain dry. Breezy conditions will be in place
until late evening with gusts of 25 to 30 kts likely at east
Idaho terminals.

&&

.FIRE WEATHER...
Issued at 158 AM MDT Wed Sep 2 2026

The primary fire weather concerns today are a Red Flag Warning
in Zone 422 due to scattered thunderstorms, alongside near-
advisory level winds across the broader lower elevations.
Fortunately, noticeably cooler temperatures in the 60s and 70s
will help keep relative humidity values from reaching critical
thresholds across the wind-prone corridors. Looking ahead, a
gradual warming trend is expected into Saturday before a strong,
cold Pacific storm system brings widespread wetting rain and a
10-to-15 degree cooldown for Labor Day and early next week.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 3 PM MDT this afternoon for IDZ422.

&&

$$

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