Alberton, Montana Weather Forecast Discussion

829
FXUS65 KMSO 041947
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
147 PM MDT Thu Sep 4 2025
.DISCUSSION...
KEY MESSAGES:
- Easterly winds expected to intensify this evening, then weaken
  but continue into Friday.
- Potential for thunderstorms increases Saturday in north central
  Idaho, then across all of western Montana and north central
  Idaho by Sunday
- Confidence in a pattern change by mid next week is growing
Persistent easterly to northeasterly winds will continue into
Friday as a weak Canadian cold front brushes along the Continental
Divide today. While speeds have decreased slightly this afternoon,
they are anticipated to increase once again this evening, with
gusts 25 to 35 mph anticipated in locations that are exposed to
the easterly wind direction. Wind advisories remain in place
through the evening across northwest Montana, where the stronger
winds are likely to be felt.
Air quality has been degraded over much of western Montana and
north central Idaho due to wildfire smoke today. The easterly
winds will likely begin to bring some improvement across northwest
Montana by Friday. However, areas such as north central Idaho may
actually see air quality degrade further as smoke currently over
western Montana is pushed westwards.
High pressure will remain over the region into Saturday,
supporting overall warm and dry conditions. The upper level
pattern will begin to shift to the southwest on Saturday into
Monday in response to a low pressure system off the west coast
gradually tracking eastwards. This will increase moisture over the
region and bring conditions conducive for thunderstorms. On
Saturday, the activity looks mainly focused through north central
Idaho. By Sunday and Monday however, thunderstorms will be
possible across all of western Montana and north central Idaho.
Any storms that develop will be capable of gusty outflow winds,
lightning, and brief heavy rain. Moisture amounts of 150-200% of
normal will bring a marginal risk of excessive rainfall,
particularly over burn scars and steep terrain, where localized
runoff or debris flows may occur.
Confidence in a pattern change by mid next week continues to
increase, with around 80 percent of forecast solutions supporting
the low pressure system off the west coast moving through the
Intermountain West region. Much cooler temperatures look likely
with this scenario. How much precipitation will fall still has a
range of possibilities, mainly due to questions on whether the
main energy with the trough comes through the Pacific northwest or
digs further south. Most solutions (70 percent) support a wetting
rain for all but far southwest Montana, but the widespread
significant rain event scenario of half an inch or more is only
supported by around 25 percent of the solutions.
&&
.AVIATION...A backdoor cold front is moving across the region
today. East winds have weakened some this afternoon, but are
anticipated to increase once again around 05/0000z with gusts up
to 30kts possible for exposed locations. In some places, strong
Foehn winds will continue on west aspects. The incoming air mass
has also brought quite a bit of smoke from wildland fires in
Canada. Visibility will likely improve slightly across northwest
and west central Montana this evening, but may actually degrade
further in southwest Montana and north central Idaho. Bottom line:
locally lowered visibility and terrain obscurations will continue
into Friday.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory until midnight MDT tonight for Flathead/Mission
     Valleys...West Glacier Region.
ID...None.
&&
$$

NWS MSO Office Area Forecast Discussion