Martin City, Montana Weather Forecast Discussion

845
FXUS65 KMSO 201209 CCA
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
226 AM MDT Sat Sep 20 2025
.DISCUSSION...
KEY MESSAGES:
-  Warm, sunny, dry conditions continue today.
-  Westerly winds with gusts 25 to 35 mph Sunday could create
   hazardous, choppy conditions on area lakes, especially Flathead
   Lake where a wind advisory may be needed.
-  Low-lying areas could experience their first frost Tuesday
   morning.
Today will be the last warm, sunny, and dry day before the ridge
of high pressure begins to break down. High temperatures this
afternoon will once again run 10 to 15 degrees above normal for
this time of year. Western Montana valleys are expected to see
highs in the low to mid 80s, while north-central Idaho valleys
will reach the 80s and 90s.
On Sunday, the ridge of high pressure will weaken and flatten as a
cold front moves through the Northern Rockies. Westerly winds will
increase and scattered thunderstorms will develop along the front,
with current timing expected from the early to late afternoon.
There is a 30 to 40 percent probability of widespread wind gusts
of 25 mph beginning shortly after the noon hour and remaining
breezy until sunset. While the probabilities are lower, around 20
percent, isolated stronger gusts in excess of 40 mph are possible,
especially with any convection that develops. Those planning to
recreate on area lakes, especially Flathead Lake, should expect
blustery conditions and a significant increase in chop.
Backcountry users along the Continental Divide can expect to see
the strongest gusts, potentially exceeding 40 mph.
A cool airmass will settle in behind the front, bringing a 30 to 50
percent probability of frost for some low-lying areas across western
Montana and the higher valleys of north-central Idaho on Tuesday
morning. This will be the first frost of the season for most valley
locations in western Montana.
A warm ridge is then forecast to build over the region Tuesday and
Wednesday, and with clear nights, patchy river fog will be
possible in the mornings.
By Thursday and Friday, the ridge will begin to shift eastward,
but temperatures will remain about 10 degrees above average.
Southwest flow will reintroduce the chance for afternoon showers
and thunderstorms toward the end of the week.
&&
.AVIATION...VFR conditions with light winds will prevail through
today. KMSO and KBTM should see gusts up to 20kts from 20/2200Z to
21/0200Z. A significant pattern change will occur Sunday
afternoon (approx. 18Z Sun - 02Z Mon) as a cold front crosses the
region. Expect increasing westerly winds with widespread gusts
around 25-30 kts and isolated gusts over 40 kt possible.
Scattered thunderstorms will develop along the front, bringing
brief MVFR/IFR conditions, lightning, and strong, erratic outflow
winds. Winds will diminish after sunset Sunday.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&
$$

NWS MSO Office Area Forecast Discussion