Red Flag Warning 2, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
149 AM MDT Fri Jul 18 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 the warmest day of the week and the weekend.
Temperatures in western Montana will range from the upper 80s to
low 90s, while north-central Idaho will see highs in the low 100s
in the lower elevations. There will be just enough instability and
moisture for isolated thunderstorms to develop over Lemhi County
and southwest Montana this afternoon and evening. Otherwise,
mostly dry conditions will prevail, with wind gusts around 20 to
25 mph across the Northern Rockies.

Saturday will be slightly cooler—possibly even a few degrees
below normal—but will remain dry and breezy across the region.
Minimum relative humidity values dropping into the upper teens and
low 20s, combined with gusty winds, will create near-critical
fire weather conditions, particularly across southwest Montana and
north-central Idaho. Currently, there is a 50 to 70 percent
probability that gusts will exceed 25 mph across western Montana
and the Camas Prairie of Idaho. A shortwave trough across the
Canadian border may bring just enough instability and lift for a
few isolated showers and thunderstorms in northwest Montana, north
of Highway 2.

Ensemble forecast models continue to agree on the arrival of
another cool, wet, and breezy weather system in the Northern
Rockies early next week. Models suggest a cutoff low pressure
system moving across central Washington on Monday, with scattered
showers and thunderstorms ahead of it over the Northern Rockies
during the afternoon and evening. As the low moves overhead on
Tuesday, a cool airmass will accompany it, along with widespread
light rainfall. The latest NBM shows a 70 to 80 percent
probability of wetting rains (>0.10") in northwest Montana, and
around 40 percent for the rest of western Montana and north-
central Idaho.

There is a 70 to 80 percent probability that we’ll return to a
hot pattern by the end of next week, with highs in the 90s (and
low 100s in north-central Idaho).

&&

.AVIATION...A west to southwest flow will remain over the
Northern Rockies today, promoting warm, mostly dry, and breezy
conditions across the region. Westerly winds with gusts between
20–25 kts are expected at KMSO, KHRF, KBTM, and KSMN this
afternoon by 18/2100Z. Winds are expected to relax after 19/0300Z
this evening. Weak instability will allow for isolated convection
over Lemhi County and southwest Montana this afternoon,
potentially impacting KSMN and KBTM between 18/2100Z and 19/0200Z.

&&

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