615
FXUS65 KMSO 161730
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1130 AM MDT Mon Jun 16 2025

.DISCUSSION...


KEY MESSAGES:

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

- Trending toward much cooler/increased precipitation chances next
  weekend.

A mid-level disturbance will help pave the way for showers and
thunderstorms across west-central and southwest Montana by this
afternoon through the 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 strong
agreement 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 (20 percent probability) or an
open wave (80 percent probability), 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...A mid-level disturbance will help pave the way for showers
and thunderstorms across west-central and southwest Montana by
this afternoon through the evening. Showers and thunderstorms will
form across the higher terrain by 16/1900-2000Z across west-
central and southwest Montana, expanding in coverage between
16/2100-17/0200Z. 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.
&&

$$