Butte-Silver Bow, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

411
FXUS65 KMSO 110812
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
212 AM MDT Fri Apr 11 2025

.DISCUSSION...

KEY MESSAGES:

- Increasing wind, clouds, and chances for rain today

- Low pressure and associated cold front bring chances for
  rain/snow on Saturday and Sunday

- Mild weather returns next week

The ridge of high pressure that was centered over western Montana
on Thursday will move east today as a trough of low pressure
deepens over the West Coast. This setup will put the Northern
Rockies under southwest flow aloft. An upper level jet streak
along with some midlevel moisture and a weak shortwave will work
together to produce some chances for showers today, mostly focused
on northwest Montana and north-central Idaho. Snow levels stay
about about 5,000 ft. There will be enough instability to allow
those strong upper level winds to mix down to the surface,
creating gusty west or southwest winds along the Continental
Divide and the mountain ranges of western Montana, as well as
southwest Montana and Lemhi County.

On Saturday, the West Coast trough and an associated cold front
will move across the region causing snow levels to fall. The
valleys will still see mainly rain showers, but the mountains will
pick up another round of snow. The most new snow accumulation
will fall along the Continental Divide, especially in the Glacier
Park region, though some accumulations are also expected in the
Whitefish, Swan, and Mission mountains as well. The overall trend
for this system has been drying, and chances for an inch or more
of water equivalent in 24 hours ending Sunday evening are only
about 10% for the higher terrain in and around Glacier Park. The
forecast for Marias Pass is for about 3-6 inches of snow by Sunday
evening.

Model ensemble solutions are in good agreement for high pressure
to build over the Northern Rockies on Monday and last through
Tuesday. Daytime high temperatures will be about 10 degrees above
seasonal norms. By Wednesday, model guidance begins to diverge.

&&

.AVIATION... A shortwave moving through northwest Montana this
morning will bring some chances for rain to KGPI through about
11/1600Z. A jet streak aloft will result in gusty west or
southwesterly winds this afternoon across the Northern Rockies.
Low level moisture will result in ceilings of about 5000 ft AGL
this afternoon. Expect increasing cloud cover this evening ahead
of a trough of low pressure arriving on Saturday.


&&

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

$$