625
FXUS65 KMSO 070956
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
256 AM MST Thu Nov 7 2024

.DISCUSSION...

KEY MESSAGES:

-  A ridge of high pressure will persist through Saturday, leading
   to areas of valley fog and stratus.

-  A Pacific system will arrive Sunday, bringing valley rain
   showers and snow above 5,000 feet.

-  An active Pacific storm pattern is expected next week, with
   periods of mountain snow.

A broad ridge of high pressure will dominate the western U.S. and
Northern Rockies through Saturday, bringing stable conditions
that will favor the development of valley inversions, especially
across western Montana. These inversions will set the stage for
areas of valley fog and stratus, particularly in northwest
Montana.

Model guidance suggests the ridge will break down on Sunday as a
trough moves onshore in the Pacific Northwest. While there is some
variation in how models forecast the strength of this system as
it progresses eastward into the Northern Rockies, the majority of
ensemble members (over 80%) predict that it will split, keeping
snow levels above 5,000 feet. Precipitation is expected to focus
primarily along the Idaho/Montana border and in the higher
terrain.

Looking further ahead, global ensemble models continue to show an
active Pacific storm pattern, with a series of troughs moving
into the region within westerly flow. This pattern appears
favorable for mountain snow. While these systems will continue to
be monitored, widespread valley winter storm impacts remain
unlikely at this time. /AL

&&

.AVIATION...GOES satellite imagery from early this morning shows
a blanket of stratus clouds over northwest Montana, while clear
skies to the south are allowing patchy radiation fog to form along
and south of the I-90 corridor. High pressure will maintain
stable conditions and light winds across the region this afternoon
and evening. /AL

&&

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

$$