420
FXUS65 KMSO 120825
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
225 AM MDT Sat Jul 12 2025

.DISCUSSION...

- Warming trend through this weekend, with moderate heat risk
  impacts across low elevations of north-central Idaho.

- A big change is likely (>70%) across the region later Monday
  into Tuesday with winter-like conditions possible along the
  Divide, especially Glacier National Park with northeast winds.

A ridge of high pressure is seen building over the Pacific Coast
this morning in GOES Satellite imagery and is expected to shift
eastwards over our region into Sunday. High temperatures will
climb into the low-100s for lower elevations of north-central
Idaho, where heat advisories remain in effect for the Lower Hells
Canyon/Salmon River Region and Orofino and Camas Prairie Regions.
Consider practicing heat safety by drinking plenty of fluids, and
resting in shaded or air conditioned environments when working
outside. Hot and dry weather, along with breezy westerly winds,
each afternoon, will lead to elevated fire weather conditions.

Forecast models continue to suggest (>70% confidence) a
significant change later Monday into Tuesday. Forecast guidance
drops a trough southeastward from Canada, with a cold front
sweeping along and west of the divide, bringing a sudden north-
northeast wind shift and much cooler temperatures across the
higher elevations along the divide. There remains considerable
timing differences with the front, along with disagreement for how
far west the front will move into western Montana. Nonetheless,
the majority of guidance suggests cold and wet conditions for
higher elevations along the divide, including Glacier Park, with
highs in the 40s Tuesday, with snow levels dropping near 8,000
feet. Those with outdoor recreation plans in the backcountry
and/or on area lakes of northwest Montana should monitor the
forecast closely in the coming days given the potential for
widespread precipitation, north-northeast winds, and much cooler
temperatures.

Once this storm system moves off to the east by mid-week, night-
time low temperatures could get down into the upper 20s and 30s
for high elevation valleys.

&&

.AVIATION...VFR conditions are expected through this weekend,
along with westerly breezes, with area TAF sites experiencing
gusts of 15-20kts, with the higher gusts focused across northwest
Montana and along the divide through this afternoon and evening.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...Heat Advisory from noon today to 8 PM PDT Monday for Lower Hells
     Canyon/Salmon River Region...Orofino/Grangeville Region.

&&

$$