Hamilton, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

442
FXUS65 KMSO 190736
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
136 AM MDT Sat Jul 19 2025

.DISCUSSION...

KEY MESSAGES:

-  Breezy, warm, and dry conditions are expected through the
   weekend.

-  A 75 percent probability exists for a cool, wet, and breezy
   weather system early next week.

Today will be slightly cooler, with high temperatures below
normal, but dry and breezy conditions will persist. Minimum
relative humidity values in the upper teens to low 20s, combined
with gusty winds, will lead to near-critical fire weather
conditions, particularly across southwest Montana and north-
central Idaho. Theres a 50-70% chance of gusts exceeding 25 mph
across western Montana. A shortwave trough near the Canadian
border may bring enough instability and lift for a few isolated
showers or thunderstorms north of Highway 2 in northwest Montana.

Sunday will feature increasing high clouds, breezy afternoon
conditions, and mild temperatures. The best chances (50-70%) for
gusts over 20 mph are along the Divide, southwest Montana, and
Lemhi County.

By Monday, a slow-moving cutoff low will settle over central
Washington and Oregon. A quasi-stationary frontal boundary from
north-central Idaho into western Montana could support light to
moderate post-frontal showers in the morning. Thunderstorm
potential will depend on daytime heating, with chances continuing
into the afternoon.

As the upper trough ejects northeast by Tuesday, stronger large-
scale lift will increase the potential for widespread showers and
thunderstorms, especially north of I-90 in northwest Montana,
where the NBM shows a 50-75% chance of precipitation exceeding
0.09". Some northeast winds may develop, but are not expected to
be as strong as those earlier this week.

A general warm-up is expected later next week into the weekend.
With upper-level flow turning southwesterly, thunderstorm chances
could return.

&&

.AVIATION...Today, slightly cooler temperatures are expected.
Breezy west-northwest winds with gusts up to 25 kts are likely,
especially in southwest Montana and north-central Idaho. A few
isolated showers or thunderstorms may develop north of Highway 2
in northwest Montana due to a passing shortwave. Localized
turbulence and brief reductions in visibility are possible in
storm proximity. Sunday will bring increasing high clouds, and
afternoon gusts of around 20 kts along the Divide, southwest
Montana, and Lemhi County.


&&

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

$$