Anaconda-Deer, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

920
FXUS65 KMSO 111905
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
105 PM MDT Fri Apr 11 2025

.DISCUSSION...


KEY MESSAGES:

- A cold front moves across the region this weekend causing
  mountain snow and valley showers.

- Strong winds will cause difficult conditions for boaters on
  Flathead Lake Saturday.

- Mild weather returns for early next week.

The ridge over the region today is breaking down. Later tonight
into Saturday morning, snow showers above 6000 feet could bring
slush at times to Lost Trail Pass, Georgetown Lake and Homestake
Pass. Snow amounts range from 1 to 2 inches in those areas.

Then a trough and its associated cold front will move across
the region causing some mountain snow Saturday night and Sunday
morning. Most of the snow will be in the Whitefish and Swan
mountains and north of the Bob Marshall Wilderness. Marias Pass is
expected to get around 2 inches and up to 5 inches at the pass,
but remote areas north of the pass are expected to get much more
with over a foot in the remote areas of Glacier Park. We have not
yet issued a winter weather advisory for this system, but we are
considering issuing one above 4,000 ft elevation in the Flathead
National Forest and Glacier National Park region. We`ll make a
final decision on that tomorrow morning. Though elevations below
4,000 ft may also have some snow accumulation, it`s not expected
to be much of an impact like it is above that level.

Strong westerly winds behind the front will cause difficult
conditions on Flathead Lake on Saturday. High resolution ensembles
show a 70-90 percent chance of having predominant winds over 20
mph for about 3 hours between 1 PM and 8 PM. The most likely
timing is between 3 PM and 6 PM. Models are showing the strongest
winds mainly on the southern portions of the lake around Wildhorse
Island.

Early next week another ridge builds in and the region returns to
more mild weather.

By Wednesday or Thursday 63 percent of ensemble models depict the
warmth continuing, but 11 percent of the ensembles depict a cool-
down across western Montana, and 26 percent depict a brief cold
front impacting the Glacier Region and Divide.


&&

.AVIATION...Increasing southwest winds and mid level cloud cover
will continue through this evening as the ridge over the region
is breaking down. Models are showing little impact for Saturday
other than some stronger southwest winds and potentially some
showers around terminal KMSO. For Saturday night through Sunday
morning, we expect showers with a cold front and possibly snow
showers. Terminals KGPI and KBTM are the most likely to be
affected with light snow accumulations Sunday morning.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Lake Wind Advisory from 1 PM to 8 PM MDT Saturday for
     Flathead/Mission Valleys.

ID...None.
&&

$$