FXUS65 KGGW 031121
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
421 AM MST Tue Dec 3 2024

.DISCUSSION...

KEY MESSAGES:
 
 - A period of surface temperatures warming to near normal is
   expected from west to east beginning this morning.

 - Aside from some brief Lake Effect snow flurries here and there,
   the next chance for light snowfall accumulation arrives by 
   late Wednesday evening. 
   
WEATHER PATTERN OVERVIEW:

General northwest flow aloft will continue to prevail across the
region for the next several days. 

A chinook arch is already developing over the northern Canadian 
Rockies. The resultant strong downslope flow will slide southward
and eastward through central and eastern Montana to begin eroding
the the cold surface air air mass over the high plains.

In response, daily high temperatures will begin to climb to near 
or slightly above normal. 

An embedded weak shortwave disturbance will slide along the
northwest flow aloft later on Wednesday this week, driven by a
much stronger low pressure system sweeping through central Canada
toward the Great Lakes region. For us locally, model data is
lining up to show some snow across the eastern zones. 

Another chinook arch pattern sets up later this week for above
normal temperatures and scattered chances for rain and snow by the
end of the week. 
 

FORECAST CONFIDENCE & DEVIATIONS: 

There is high confidence in near normal temperatures occurring by
this afternoon area-wide. The question will be how much of the 
warm air aloft will erode the cold inversion. There is medium to 
high confidence of temperatures dropping slightly Wednesday and 
Thursday. There is medium confidence on snow showers occurring 
Wednesday night. Low confidence remains for any further precip 
chances beyond Thursday.


&&

.AVIATION...
VFR with partly cloudy to mostly sunny skies through the period.
The exception will be during the early morning hours where lake
effect low clouds could drift over KGGW or KOLF.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/glasgow