Kalispell, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

810
FXUS65 KMSO 190800
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
200 AM MDT Thu Jun 19 2025

.DISCUSSION...

KEY MESSAGES:

- Strong thunderstorms, with isolated severe threat, Thursday
  into Friday across west-central and southwest Montana.

- Widespread precipitation Friday night into the weekend, with
  cooler temperatures, and high elevation snow.

- Signifcant snow, for this time of year, across Glacier National
  Park and the Flathead National Forest Saturday into Sunday
  Morning.


Showers and thunderstorms will return by mid-afternoon across
southwest Montana, focusing across Ravalli, Granite, Deer Lodge,
and Silver Bow Counties and in Lemhi County, ID as southwesterly
flow transports Pacific moisture and instability into the region.
Forecast soundings continue to highlight inverted-V profiles,
along with modest shear and instability, supporting the
development of strong to isolated severe thunderstorms (5%
probability), with strong outflow winds being the primary concern.


The risk for strong to isolated severe thunderstorms expands into
west-central Montana and along the divide in northwest Montana
Friday. A cut-off low will move inland across the Pacific
Northwest, with south-southwest flow bringing increased moisture
and instability, while the low provides synoptic ascent. Forecast
models suggest isolated thunderstorms will form early in the
morning, spreading south to north from Lemhi County, Idaho and
southwest Montana into west-central Montana and along the divide
in northwest Montana. The environment will support storms capable
of producing small hail, gusty winds, and periods of heavy rain.
An isolated storm or two will be capable of producing large hail
and strong to potentially damaging winds, with the greatest threat
focused along the divide in southwest Montana, north of where a
surface low will deepen in the afternoon. One caveat, will be the
morning activity and residual cloud-cover into the afternoon. This
could help suppress the strongest convection from really getting
going. Stay tuned!

Little has changed with forecast guidance in the last 12-24hrs
with regards to the closed low expected to impact the Northern
Rockies late Friday into the weekend, with widespread
precipitation, cooler temperatures, and high elevation snow.
Ensemble models have come into stronger agreement with the track
of the mid-level low, with the low tracking along the USA-Canada
border Friday night into Saturday morning, before slowly
meandering into southeast Alberta into Sunday morning.
Probabilities for widespread rain remain high, with areas north of
I-90 having a 90% chance for >0.50 inches of rain, with 50-70%
south of I-90. Flathead and Lincoln Counties are favored to
receive the highest precipitation amounts with a 50-60% chance for
2 or more inches of precipitation across northern Lincoln County
and across Glacier Park and the Flathead National Forest. This
precipitation will increase the risk for rock and debris slides
along steep terrain in Glacier National Park and Forest Service
roads in the Flathead and Kootenai National Forests. Low land
ponding of water will be possible in poor drainage areas.

Those with plans in the backcountry and/or high elevations should
begin preparing for cold temperatures, accumulating snow, and raw
conditions, including Glacier National Park. Speaking of Glacier
Park, models are indicating 4-18 inches of snow, depending on
elevation. Of particular note is Logan Pass, where the middle of
the road forecast has increased to 10 inches, with a 40% chance
for a foot or more. Due to the late season snow potential and
activity in the backcountry, a Winter Storm Watch remains in
effect Saturday into Sunday morning. The heaviest snow is
anticipated to fall Saturday evening through early Sunday morning.
Plan accordingly if traveling across northwest Montana,
particularly the higher terrain.

After the low exits the region late Sunday, a cold dry air mass
will settle in behind it. Monday morning low temperatures will
likely be at or below freezing for the higher valleys along the
Continental Divide and mid 30s for the larger valleys along the
Highway 93 corridor.

&&

.AVIATION...Scattered showers and thunderstorms will develop
across Lemhi County, ID and southwest Montana, this afternoon,
with convective initiation beginning by 19/19-20Z. Storms will
track quickly to the northeast, with the highest threat of
lightning (50-60% chance) across Silver Bow, Deer Lodge, and
Powell Counties between 19/23Z-20/0300Z. Strong thunderstorms are
expected across these areas, with an isolated threat (5%
probability) for severe damaging winds of 50kts. Deepening south-
southwest flow ahead of a closed low will bring increased
moisture and instability overnight into Friday morning, with
convection moving south to north across central ID starting
around 20/0600Z, before spreading into west-central and northwest
Montana through 20/08Z and 20/12Z respectively.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch from Saturday afternoon through Sunday
     morning for West Glacier Region.

ID...None.
&&

$$