530
FXUS65 KMSO 040336
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
836 PM MST Mon Nov 3 2025

.UPDATE...Winter weather advisories have been issued for northwest
Montana until noon Tuesday.


&&

.DISCUSSION...

Snow levels are remaining low this evening and lowering with the
next round of precipitation, so the forecast has been snow levels
have been lowered. Where precipitation have been moderate, slushy
accumulations are being observed, and valley snow accumulations
are expected by Tuesday morning. Moderate impacts are expected
over Lookout and Marias passes with up to 5 inches of snow. Be
prepared for changing travel conditions tonight and Tuesday
morning.


&&

.AVIATION...A stalled frontal boundary extends from southwest
Idaho towards southwest Montana. To the north, overrunning
precipitation will fall as snow, consistently down to 3000 feet
MSL in northwest Montana, and above around 4,000 feet MSL from
Lookout Pass to west- central Montana, through Tuesday morning.
Expect IFR conditions across northwest Montana from through
04/1800Z (1100 am Tuesday). As surface winds weaken overnight and
the low levels moisten up a bit, fog will also accompany the lower
ceilings. Ceilings are not expected to be as low for the
remainder of the terminals from MSO southwards by Tuesday morning.
Persistent showers are expected along the Idaho/Montana border
and in the northwest Montana mountains through Tuesday afternoon.

&&

.PREV DISCUSSION... /ISSUED 143 PM MST Mon Nov 3 2025/

DISCUSSION...

KEY MESSAGES:

- Widespread precipitation tonight with high elevation snow
  especially for northwest Montana.

- Active weather pattern for the remainder of the work week.

- Breezy conditions Thursday and Friday.

- High pressure over the region this weekend.

A plume of moisture will be streaming into the Northern Rockies
for the remainder of today into Tuesday morning. Snow levels will
be steadily rising throughout the night causing accumulating snow
to be mainly confined to the higher terrain especially across
northwest Montana. The mountains of northwest Montana are expected
to receive several inches of new snow by Tuesday morning with
Marias Pass receiving 2 to 5 inches. Wet and raw conditions are
expected for the backcountry causing high elevation non-paved
roads to become sloppy and/or snow covered.

A short-lived ridge of high pressure slides through the region
Tuesday afternoon into Wednesday morning causing a reduction in
the shower activity across the Northern Rockies. The next round of
precipitation is expected to push into the region by Wednesday
evening. Snow levels will be once again rising across the region,
limiting snow to the highest terrain as mountain passes are not
expected to have much impact.

A short break in the precipitation is expected late Thursday into
the Friday, then another disturbance will impact the region Friday
into Saturday. Once again snow levels will be fairly high so
impacts are anticipated to be minimal.

The upper level winds are expected to increase Thursday and Friday
allowing for gusty west winds to mix to the surface, particularly
during the afternoon hours.

A stronger ridge of high pressure is expected to build over the
Northern Rockies Saturday into Monday morning. This ridge will
create stable conditions with light and variable winds which
combined with moist low levels should allow for the development of
fog and/or low stratus in the valleys of the Northern Rockies.

AVIATION...A stalled frontal boundary extends from southwest
Idaho towards southwest Montana. To the north, overrunning
precipitation will fall as snow, generally above 4,000 feet MSL in
northwest Montana, and above 5,000 feet MSL from Lookout Pass to
west-central Montana, this afternoon through Tuesday morning.
Expect LIFR conditions across northwest Montana from 04/0100Z
(1800 pm MST Monday) through 04/1800Z (1100 am Tuesday). As
surface winds weaken overnight and the low levels moisten up a
bit, fog will also accompany the lower ceilings. Ceilings are not
expected to be as low for the remainder of the terminals from MSO
southwards by Tuesday morning. Persistent showers are expected
along the Idaho/Montana border and in the northwest Montana
mountains through Tuesday afternoon.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until noon MST Tuesday for
     Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
     Clark Fork Region...Potomac/Seeley Lake Region...West
     Glacier Region.

ID...None.
&&

$$