FXUS65 KMSO 041925

AFDMSO



Area Forecast Discussion

National Weather Service Missoula MT

125 PM MDT Mon May 4 2026



.DISCUSSION...



KEY MESSAGES:



 - A backdoor cold front continues to bring cooler temperatures 

   and northeast winds of 20 to 30 mph across western Montana 

   today and Tuesday.



 - Boaters on Flathead Lake should anticipate choppy conditions 

   returning this evening and Tuesday due to gusty northeast 

   winds.



 - A warming trend begins Wednesday, though a disturbance will 

   bring showers to northwest Montana late Wednesday, followed by 

   showers and isolated thunderstorms along the Continental Divide

   on Thursday.





A backdoor cold front will continue to move westward this 

evening, bringing increasing north and east winds. By Tuesday, 

the upper-level jet stream will orient itself almost directly out 

of the north. This creates a tight pressure gradient across the 

Northern Rockies, sandwiched between the eastern trough and the 

western ridge. Expect the gusty winds to persist throughout 

Tuesday, making it feel notably cooler than the actual air 

temperature.



Flathead Lake will experience enhanced winds this evening and 

Tuesday. Expect an increasing north and east winds, with gusts 

reaching 20 to 30 mph, particularly over the open waters of the 

south half. These winds will generate chop and potentially 

hazardous boating conditions. 



By Wednesday, the tight pressure gradient will relax as the ridge

of high pressure to our west expands eastward. This will shut off

the gusty northerly winds and initiate a warming trend, with 

western Montana valleys returning to the 70s and the lower valleys

of north-central Idaho pushing into the 80s. However, this will 

not be a completely dry ridge. Most guidance indicates a 

disturbance will ride over the top of the ridge late Wednesday 

into Thursday. This atmospheric forcing will initially trigger 

showers across northwest Montana late Wednesday, particularly 

impacting the Glacier Park region. As the system progresses on 

Thursday, instability will increase slightly, shifting the threat

southeastward and bringing showers and isolated thunderstorms 

primarily along the Continental Divide.





&&



.AVIATION...A backdoor cold front will continue to create impacts

for the Northern Rockies airspace. Aviation interests navigating

over the Continental Divide this afternoon will encounter

localized precipitation, mountain obscurations, and terrain-

induced turbulence. For valley and terminal specifics, expect

gusty northeast to east winds this afternoon. KMSO, KGPI, and KBTM

will see gusts of 20 to 30 knots, remaining elevated into the

evening hours (particularly after 2200Z). KHRF will experience a

more northerly wind shift to around 20 knots this afternoon and

evening. These gusty and erratically shifting winds will continue

through Tuesday as the flow becomes more purely northerly. Periods

of turbulence will likely continue through Tuesday along the

Divide due to the tight pressure gradient.



&&



.MSO WATCHES/WARNINGS/ADVISORIES...

MT...None.

ID...None.

&&



$$