143 
FXUS65 KMSO 160855
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
255 AM MDT Sun Oct 16 2022

.DISCUSSION...High pressure will strengthen over the region 
through Wednesday bringing warm days, cool nights, and generally 
clear skies. Valley afternoon temperatures will continue to run 
15 to 20 degrees above normal for this time of year, ranging from
upper 60s to 70s across western Montana and central Idaho. Very 
stable conditions under the strong high pressure ridge will lead 
to stagnant air, with skies likely becoming noticeably hazy 
through the week.

For Thursday into Friday, the majority of forecast models (80
percent) are showing the ridge beginning to weaken with the flow 
aloft turning westerly to northwesterly. The main result will be a
slight cooling in temperatures with breezy winds, particularly in
the afternoon and evening hours.  

Confidence continues to grow in a more significant pattern change
beginning next weekend (October 22 and 23), as 85 percent of 
forecast models now show a broad trough of low pressure digging 
into the region. This pattern would favor much cooler
temperatures, breezy conditions, and precipitation. The 
backcountry and high elevation mountain passes would also likely 
see accumulating snowfall in this scenario, making for raw 
conditions.

There is an outside chance (20 percent) of an even colder push of
air out of Canada towards Monday/Tuesday of the following week
(Oct 24 and 25). If this scenario were to develop, it's possible 
we could see valley temperatures top out in the 30s, with snowfall
possible down as low as 3500-4000 feet. While this is not the 
most likely scenario at this time, it's worth keeping an eye on
for potential impacts across the region. 

&&

.AVIATION...High pressure will strength over the region today,
lasting through Wednesday. This will result in light, terrain
driven winds and generally clear, though hazy, skies. Patchy river
fog is possible this morning, particularly across northwest
Montana, but should be shortlived and localized. 

&&

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

$$