593
FXUS65 KMSO 130811
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
211 AM MDT Fri Jun 13 2025

.DISCUSSION...


KEY MESSAGES:

- Thunderstorms again today, some storms may be strong.

- A weak ridge builds over the region Sunday, causing fewer
  showers over the region.

A trough moving across the region today will cause another round
of thunderstorms. There is some uncertainty about how strong they
will be which comes down to timing. Current model forecasts have
the peak lift from the short wave enhancing storms in the morning
and early afternoon. That means that there won`t be much time for
the Sun to heat things up and build up instability, which would
support stronger storms. The earlier arrival of the trough will
also cause more cloud cover, which will somewhat inhibit the
heating of the day. If however the trough arrives later in the
day, conditions will be more unstable and the storms will be
stronger with more shear to support hail growth. Current timing
favors stronger storms east of the Continental Divide.

Sunday, a weak ridge builds over the region. Models are showing
some drying, so it won`t be as humid and there won`t be as much
moisture to support thunderstorms. However, the ridge isn`t very
strong and it is embedded in a much larger trough pattern over the
region with southwest flow. As a result, some thunderstorms and
showers are still possible, especially over the mountains in areas
with up-slope aligned winds.

&&

.AVIATION...A shortwave moving into the region this morning will
cause increasing cloud cover, showers, and thunderstorms. With the
morning and early afternoon timing of the trough, severe storms
are not expected due to less diurnal heating. The stronger storms
are expected east of and along the Continental Divide, that means
in our area terminal KBTM is the most likely to see stronger
convection. Unlike recent days, the presence of a well defined
trough and a jet streak will provide more shear if any strong
updrafts do get started.


&&

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

$$