Butte-Silver Bow, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

152
FXUS65 KMSO 062010
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
110 PM MST Fri Mar 6 2026

.DISCUSSION...

KEY MESSAGES:

- Minimal impact from light snow tonight and Saturday

- Strong Winds Sunday into Monday, with a 60 to 80 percent chance
  of widespread gusts over 40 mph in the valleys.

- Active Pattern for the rest of next week/weekend; potential for
  more wind and winter weather impacts.

Satellite imagery this afternoon depicts a broad region of high
pressure off the West Coast, and low pressure over southern
Alaska. These features are working together to send a long fetch
of moist air into western Canada and the Pacific Northwest under
northwesterly flow aloft. Although the moisture will arrive in
waves for the Northern Rockies, weather will remain unsettled well
into the coming week.

The first wave of moisture arrives tonight. Lack of appreciable
large-scale lift will make the mountains do the work, so snow
accumulations will be limited to the higher terrain and favor the
long, north-south oriented ranges north of I-90 such as the
Missions, Swans, and the Continental Divide in Glacier Park. Snow
levels stay in the neighborhood of 4,000 ft. Travel impacts will
be minimal, expect only a trace to a few inches over Lookout,
Marias, and Lolo passes by Saturday afternoon.

The focus on Sunday will switch to wind. A strong upper level jet
will become positioned over northwest Montana and the Idaho
Panhandle by Sunday afternoon. Model soundings indicate enough
instability for upper level winds to mix down to the surface,
where widespread southwesterly gusts of about 30-40 mph will be
commonplace. Expect more isolated gusts of 50 mph, while the
higher terrain will experience gusts of over 60 mph. High winds
will become reinforced by a cold front passing overnight on
Sunday, so High Wind Watches for all of western Montana will
remain in effect through Monday morning.

The Pacific ridge/Alaskan trough configuration will keep the upper
level jet pointed at the Northern Rockies through next week into
next weekend (March 14-15). The Climate Prediction Center (CPC)
guidance for March 14-16 highlights a 20-40% chance of both high
winds and heavy snow. While significant model variance regarding
snow levels limits specific valley accumulation forecasts at this
range, the period requires close monitoring for renewed winter
impacts and at least moderate mountain pass travel disruptions.

&&

.AVIATION...A few light showers persist south of I-90 in northwest
flow, remaining mostly terrain-focused. Expect VFR conditions at
all terminals into early evening with light winds, though
occasional gusts of 15-20 kts are possible in well-mixed areas.

A weak disturbance arrives after 07/0300Z, bringing moisture from
a decaying atmospheric river. Expect increasing mountain
obscurations and light precipitation through Saturday morning,
possibly becoming a rain/snow mix in valleys by 07/1200z. Fairly
widespread MVFR ceilings and visibility will likely develop across
northwest/west-central Montana, including KGPI and KMSO. Brief
drops to IFR category are possible under heavier showers. While
shower activity will continue into the afternoon, it will become
more focused over the terrain after 07/1800z. Mechanical
turbulence near ridge top levels is possible late tonight and
early tomorrow morning as ridgetop winds increase to around 40
kts. KBTM in particular may have concerns with LLWS. Winds will
become more widespread and gusty between 15 to 25 kts in the
afternoon as the atmosphere destabilizes.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Watch from Sunday afternoon through Monday morning for
     Bitterroot/Sapphire Mountains...Butte/Blackfoot Region...
     Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
     Clark Fork Region...Missoula/Bitterroot Valleys...
     Potomac/Seeley Lake Region...West Glacier Region.

ID...None.
&&

$$