924
FXUS65 KMSO 200822
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
222 AM MDT Sun Apr 20 2025

.DISCUSSION...

KEY MESSAGES:

- Mostly unsettled weather with valley rain, mountain snow, and
  gusty west winds today.

- Snow over mountain passes on Monday morning.

- Unsettled spring-like weather will continue into the middle of
  next week with a warm-up later in the week.

Moist westerly flow will keep some showers in the forecast for
today. The best chances for precipitation will be across
northwest Montana and north-central Idaho in the morning,
spreading southward across the remainder of the Northern Rockies
in the afternoon. Snow levels will fall to about 5000 feet for
northwest Montana and the Clearwater range in Idaho. Tonight, a
trough of low pressures will deepen over the Northern Rockies,
bringing more widespread precipitation in time for the Monday
morning commute. This system will have some colder air associated
with it, so expect snow levels to lower to around 4000 feet for
northwest Montana and north-central Idaho. Lookout, Lolo, Lost
Trail, and Marias passes could all pick up a few inches of snow by
Monday morning. The position of an upper level jet streak and an
unstable atmosphere will be conducive to windy conditions during
the day Monday as well.

Ensemble model solutions are showing an unsettled pattern of
westerly flow with some embedded shower activity, mostly for
northwest Montana and the Clearwater range in Idaho, through
Tuesday. Temperatures for the week will be mostly seasonable, with
Thursday being the warmest.

&&

.AVIATION...Isolated rain showers will continue to stream across
northwest Montana, mainly along and north of the Highway 2
corridor. Brief periods of lowering ceilings and reduced
visibility will occur at KGPI through 20/1400Z this morning. A
moist westerly flow, with modest instability will be conducive for
widespread showers developing this afternoon and evening across
all of the Northern Rockies. The main impacts will be brief
lowering of ceilings and reduced visibility, along with gusts
between 20-25kts. Shower activity is expected to continue through
the overnight hours, with snow levels lowering to around 4000 feet
by Monday morning.

&&

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

$$