Butte-Silver Bow, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

608
FXUS65 KMSO 140951
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
251 AM MST Sat Feb 14 2026

.DISCUSSION...

Key Points:

-Pass Impacts: Accumulating snow on Marias, Lookout, and Lolo
 passes this weekend; travel may be slick, especially overnight
 tonight.

-Arctic Potential: Monitoring the potential for a push of colder
 air Tuesday and again late next week (Feb 20-21).

Southwest flow will maintain light to moderate precipitation across
North-Central Idaho and Northwest Montana today, expanding southward
through Sunday. While primarily terrain-focused, expect spillover into
valleys as a rain/snow mix.

   -Valleys: Very light snow accumulations are more likely to
    occur in Northwest Montana during overnight periods. Localized
    slick spots are possible during the morning hours.

   -Mountain Passes: 48-hour snowfall totals (through Sunday) of 3
    to 8 inches are forecast for Marias, Lookout, and Lolo passes.
    Rates will remain manageable at 1 to 2 inches per 6 hours.

While no advisories are currently in effect, convective pulses
tonight may necessitate highlights for the passes, especially in
the West Glacier Region (including Marias Pass).

Following a brief lull Monday, a vigorous upper-level trough arrives
Tuesday. Most models (60%) favor a more northern track of the trough,
bringing a 50 percent probability of 1 to 2 inches of snow for
northwest Montana valleys. Mountain passes and higher elevations
above roughly 4,500 ft will most likely see a range of 2 to 6
inches of accumulating snow (25th to 75th percentile).

A signal for colder arctic air remains, with approximately 50
percent of ensemble members suggesting a modified Arctic air mass
clipping Northwest Montana on Tuesday. If this deeper cold air
manifests, snowfall ratios and totals will increase along the
Continental Divide.

An unsettled west-northwest flow continues through Saturday, Feb 21.
Confidence is growing (30 to 40%) for a more significant Arctic
intrusion by next weekend. This scenario would likely pin snow
levels to valley floors and increase travel impacts across the
region.


&&

.AVIATION...Widespread mountain obscurations are anticipated today
as southwest flow aloft allows for a surge of moisture and
showers into the region. Periods of light to occasionally moderate
precipitation will develop, initially focusing on terrain north
of I-90 before expanding southward through the day today. While
showers may pass over lower valleys, terminals are expected to
remain predominantly VFR with ceilings staying above critical
thresholds. KGPI may see a light wintry mix early this morning,
leading to icy patches depending on runway surface temperatures.
Surface winds will shift to the southwest and strengthen through
this afternoon, with vertical mixing supporting gusts of 15-20 kts
at valley locations.

&&

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

$$