250
FXUS65 KMSO 160846
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
246 AM MDT Mon Jun 16 2025

.DISCUSSION...

KEY MESSAGES:

- Scattered showers/thunderstorms, mainly west-central and southwest
  Montana, afternoon hours/evening.

- Trending toward much cooler/increased precipitation chances next
  weekend

A mid-level disturbance is seen moving across central OR in GOES
Satellite imagery early this morning and will help pave the way
for showers and thunderstorms across west-central and southwest
Montana by mid-afternoon through this evening. Forecast soundings
suggest the best axis of moisture and instability will take shape
along the divide in southwest Montana, where brief heavy rain and
small hail will accompany stronger thunderstorms. Elsewhere,
typical pulse showers and thunderstorms are expected, with brief
rain, gusty winds, and lightning being the main hazards.

An overall drying trend is expected Tuesday into Thursday this
week under a westerly flow pattern. Temperatures will climb some
5-10 degrees above average each afternoon. Afternoon winds will
also be breezier (gusts 25-35 mph), especially Wednesday as the
westerly pressure gradient tightens.

In the extended, global ensemble models remain in stronger than
normal agreement (>90% of members) for a large upper level low to
bring much cooler temperatures and increased chances for
widespread precipitation next weekend (June 21-22). Much will
depend on how the trough evolves either as a closed low or an open
wave, as the closed low would allow for widespread precipitation
and lower snow levels compared to an open wave. Considering it
will be late June, it`s noteworthy that middle of the road snow
levels are forecast at 6500-7000 feet but would be another 1000 to
1500 feet lower if a strong closed low develops. This would open
up a potential for impacts to back country users including in
Glacier National Park. Gardeners may need to be aware of frost by
Monday morning as well, mainly along the Divide.

&&

.AVIATION...Satellite imagery shows mid-high level clouds
streaming through eastern OR into the Northern Rockies early this
morning associated with a Pacific disturbance within
southwesterly flow. Showers and thunderstorms will form across the
higher terrain by 16/1800-1900Z across west-central and southwest
Montana, expanding in coverage between 16/2100-17/0000Z. A few
stronger storms, capable of producing heavy rain and small hail
will focus along the divide, where the best axis of instability is
expected.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$