270
FXUS65 KPIH 051747
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1147 AM MDT Sat Sep 5 2026

.KEY MESSAGES...

- Favorable Saturday and Most of Sunday: Low-level southerly
  flow will boost valley temperatures into the lower 80s today
  and on Sunday. Rain chances hold off until late Sunday evening
  and overnight, keeping the vast majority of Sunday daylight
  hours dry.

- Lighter Rain Totals & Late Holiday Clearing: Storm-total
  precipitation has trended lower down to 0.10"0.30". Morning
  rain and cloud cover on Labor Day Monday will clear by early-
  to-mid afternoon, leaving cool conditions (highs in the 60s
  and lower 70s) for late afternoon and evening outdoor plans.

- Chilly Monday Night: Post-frontal clearing and cold advection
  will drop Monday night/Tuesday morning lows into the 30s
  across high country basins and 40s on valley floors.

- Mid-Week Warm-Up: Temperatures recover back toward seasonal
  norms in the upper 70s and lower 80s Wednesday and Thursday
  before the next Pacific Northwest system approaches late week.

&&

.DISCUSSION...
Issued at 240 AM MDT Sat Sep 5 2026

Persistent cloud cover and light rain continue across the
Central Mountains this morning as the eastern edge of a Pacific
Northwest low channels moisture overhead. High-resolution
convective-allowing models (CAMs) indicate this activity will
briefly wane late this morning through the afternoon, offering a
short dry window. While isolated showers may redevelop late
tonight across the Central Mountains, the rest of eastern Idaho
will remain dry. Afternoon maximum temperatures will reach the
lower 80s across the lower Snake Plain and Magic Valley, with
mountain zones holding in the mid-to-upper 70s.

Low-level southerly flow will strengthen on Sunday ahead of the
approaching upper-level low. Guidance continues to trend storm-
total precipitation lower (0.10" to 0.30") while delaying rain
chances until late Sunday evening and overnight. Consequently,
the vast majority of eastern Idaho will enjoy dry daylight hours
on Sunday, with valley temperatures warming back into the lower
80s.

Early morning rain showers and cloud cover on Monday will clear
out from west to east during the early-to-mid afternoon, with
precipitation ending well before sunset. This timing allows the
second half of the holiday to remain usable for outdoor
festivities, albeit in a seasonably cool environment with highs
in the 60s and lower 70s. Clearing skies Monday night will drive
overnight lows into the 30s across high country basins and 40s
in valley floors.

Tuesday remains cool with lower-elevation highs in the lower-to-
mid 70s and mountain highs in the 60s. Flow turns predominantly
zonal Wednesday and Thursday, pushing valley temperatures back
toward seasonal averages in the upper 70s and lower 80s under
generally dry conditions. Model guidance indicates another
Pacific Northwest trough digging south Friday into next weekend,
which could lower temperatures slightly while increasing cloud
cover and low-end precipitation chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1146 AM MDT Sat Sep 5 2026

A weak shortwave feature will produce another low chance of
light SHRA at KSUN overnight, otherwise quiet VFR conditions are
expected at all sites. Looking ahead to late Sunday, an
approaching upper level low will increase southerly flow across
the region, bringing an increase in moisture and clouds late in
the day, with precipitation chances increasing into the
overnight.

&&

.FIRE WEATHER...
Issued at 240 AM MDT Sat Sep 5 2026

Widespread critical fire weather conditions are not expected
over the next several days due to seasonable temperatures, high
overnight recoveries, and incoming light wetting rains. Light
rain over the Central Mountains clears briefly this afternoon
before isolated mountain showers return overnight. Strengthening
southerly breezes on Sunday afternoon will precede a late-night
moisture push, delivering 0.10" to 0.30" of cumulative wetting
rain through Monday morning. Seasonably cool temperatures Monday
and Tuesday will keep active fire behavior suppressed before a
warming trend returns mid-week.

&&

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

&&

$$

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