490 
FXUS65 KMSO 072040
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
140 PM MST Sun Nov 7 2021

.DISCUSSION...The weather pattern this next week will be
deceptively mild. Overall, there is a deep, broad trough south of
Alaska that extends south across the eastern Pacific Ocean and a
ridge over the US Southwest that extends north into Montana. For
the next week or so, the Pacific trough will eject a series of
smaller troughs into the westerly flow and the ridge. When that
happens, they knock down the ridge a little, but it also weakens
each trough system as it moves through the ridge.

The result of all of that is active, but generally mild weather.
Frequent changes from sunshine to clouds and light precipitation
will be the norm. The deceptive part is the temperatures. With the
light precipitation and occasional clearing out, temperatures can
drop below freezing easily and cause ice to form. Overall, expect
any ice impacts to be patchy and intermittent, which makes them
hard to predict. If you're traveling overnight or in the morning 
for the next week or so, be prepared for occasional patches of ice
on the roads.

The most significant such system looks to occur on Tuesday and
Wednesday, and the pattern continues through the end of the week.

Ahead of the next system, we're closely watching Tuesday morning 
for potentially very strong winds on the Camas Prairie of Idaho
near Grangeville. Strong southerly winds are likely along US 95 
from McCall through Riggins and up through Grangeville. The 
strongest winds are expected southwest of Grangeville with 
multiple modeling systems indicating the potential for wind gusts 
around 50 mph. Strong winds 40-50 mph are very likely, severe 
winds over 60 mph are possible.

&&

.AVIATION...Moist southwest flow and a cool air mass are causing
shallow instability under slowly rising heights today. Expect
broken ceilings with isolated mountain showers through this
evening. Upslope flow will keep low clouds entrenched in the 
mountains with some downslope flow and clearing in the valleys 
tonight.

&&

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

$$