Kalispell, Montana Weather Forecast Discussion

034
FXUS65 KMSO 221947
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
147 PM MDT Mon Sep 22 2025
.DISCUSSION...
KEY MESSAGES:
- Widespread valley frost possible Tuesday morning, especially
  western Montana
- Warming and drying trend through late week
- Breezy westerly winds Thursday/Friday
High pressure is building over western Montana and north central
Idaho today and will remain in place through the rest of this
week bringing plenty of sunshine. Daytime temperatures will run
around 10 to 15 degrees above normal for this time of year by mid
week (low to mid 80s), while mornings will be crisp with frost.
Speaking of frost, ideal conditions for radiational cooling will
be in place tonight due to a dry airmass in place, little to no
cloud cover and light winds. Valley temperatures will likely drop
into the low to mid 30s, especially in western Montana valleys,
bringing the first widespread frost of the season. Frost
advisories have been issued for tomorrow morning. If you have
sensitive vegetation, consider taking steps to protect it tonight!
The upper level ridge is anticipated to flatten on Thursday into
Friday, which will bring an increase in westerly winds to the
region. This will also allow for slight cooling on Friday,
although still warmer than typical.
There is still a fair amount of uncertainty with the forecast this
weekend. Solutions still diverge significantly, with various
members supporting a persistent ridge, a transition to southwest
flow with increased moisture (thunderstorms?), or the arrival of a
cooler trough.
&&
.AVIATION...Mostly clear skies and calm winds will prevail today
and on Tuesday under a ridge of high pressure. Expect VFR
conditions during this time. Some haze due to wildfire smoke could
develop at KSMN this afternoon and evening.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Frost Advisory from 3 AM to 10 AM MDT Tuesday for
     Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
     Clark Fork Region...Missoula/Bitterroot Valleys.
ID...Frost Advisory from 3 AM to 10 AM MDT Tuesday for Eastern Lemhi
     County.
&&
$$

NWS MSO Office Area Forecast Discussion