Libby, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

598
FXUS65 KMSO 071933
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
133 PM MDT Mon Jul 7 2025

.DISCUSSION...

KEY MESSAGES:

-  Hot mostly dry on Tuesday

-  Increasing thunderstorm chances on Tuesday and Wednesday,
   capable of gusty winds

- Cooler, showery, and breezy by Thursday

High pressure is expected to peak on Tuesday, bringing hot
temperatures across the region. Daytime highs in the lower valleys
of north-central Idaho are forecast to reach 100-108F, with warm
overnight lows in the mid-60s to low 70s. This combination will
result in moderate to major heat impacts, and a heat advisory is
in effect. Moisture will also increase from the southwest,
bringing afternoon and evening thunderstorm chances. The main
focus for storms capable of producing gusty outflow winds is the
southern half of Idaho County, Lemhi County, and southwest
Montana.

Moisture will continue to increase Tuesday night, with high-
resolution models showing isolated showers and thunderstorms
overnight. More widespread thunderstorms are expected late
Wednesday afternoon through the evening. Breezy winds will also
develop across north-central Idaho and western Montana Wednesday
afternoon, which, combined with hot and dry conditions, will
increase fire weather concerns, especially in north-central Idaho.

Model guidance has been trending toward a deeper trough dropping
out of Canada on Thursday. This system and its cold front will
bring cooler daytime temperatures, northwest winds, and higher
chances for showers. The best chance for rain appears to be in
northwest Montana, with cool and wet conditions likely in the
Glacier region.

A warming and drying trend is expected to return Friday and
continue through the weekend as high pressure builds back into the
Northern Rockies.

&&

.AVIATION...High pressure will peak Tuesday, bringing hot
temperatures and density altitude concerns, especially in north-
central Idaho where valley highs will reach 100-108F with warm
overnight lows. A heat advisory is in effect.

Moisture will increase from the southwest, with scattered
afternoon and evening thunderstorms possible Tuesday, mainly over
the southern half of Idaho County, Lemhi County, and into
southwest Montana. Gusty outflow winds will be the main hazard.
Isolated showers or storms may linger overnight Tuesday.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...Red Flag Warning from 11 AM to 8 PM PDT Wednesday for
     Palouse/Hells Canyon.

     Heat Advisory from 11 AM to 9 PM PDT Tuesday for Lower Hells
     Canyon/Salmon River Region...Orofino/Grangeville Region.

&&

$$