Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 032144
Area Forecast Discussion
National Weather Service GLASGOW MT
244 PM MST Sat Dec 3 2016
.SHORT TERM...for northeast Montana...tonight through Mon...
The system currently bringing snow squalls to portions of
northeast Montana will exit to the east late this afternoon,
allowing some partial clearing of skies and dry conditions
overnight tonight. Lingering westerly winds will keep temps mild
for this time of year, with many areas seeing lows in the mid 20s.
Upper ridging will be the dominant player on Sunday, again making
for mild temperatures, with southwest winds at the surface. Weak
disturbances ahead of the main front will create the potential
for some rain and snow mix during the afternoon hours across the
Sunday night the surface cold front will quickly push through,
bringing increasing northwest winds, as well as better potential
for a quick shot of snowfall. Models continue to back off on
significant snowfall with this system, with the ECMWF showing
little to no precipitation with it. Thus, think the best chances
for snowfall will lie across Wibaux county and possible southern
Cold air will continue to stream in out of Canada through the day
on Monday, making for steady or falling temps, as well as breezy
northwest winds. Wind chill readings will drop below zero during
the afternoon. Gilchrist
.LONG TERM...Mon night through Sat...
Overall, similar thinking still exists for the cold push of arctic
air through NE Montana from the Canadian Rockies generally through
the middle of next week.
By Monday night, the area will already be post-frontal with a
steady breezy NW wind. For snowfall, only expecting very light
amounts of left over flurries as the larger storm system deepens
over the Dakotas and Minnesota. Of greater concern for this area
will be the threat of marginally hazardous wind chill values,
especially Tuesday night and Wednesday night. Wind Chill Advisory
might be needed as area sustained winds at the surface are
expected to remain near or above 10 mph.
Previous long term discussion: The extended period begins Monday
evening with the base of a long- wave upper trough plunging south
into the Northern High Plains, leading the way for an incursion of
frigid Arctic Air. 00Z Tuesday 850mb temperatures are progged by
GFS at -18C. By 18Z, progged at -24C. This will drive most surface
lows to single digits below zero. Tuesday surface highs will only
rise into single digits above zero, about 20F degrees below
The winter storm system will have mostly moved out of the area at
the start of the extended period and will begin stacking up on
Tuesday over northern Minnesota. So expect only tapering off light
snow locally Monday evening. The strongest northwest winds will
also have moved on east, but CAA will reinforce those winds
into the evening. This is not usually picked up well by the
models. Expect widespread low stratus in the wake of the departed
system to stick around through at least Wednesday, and maybe
This will also be the first wind chill event of the season, with
probable headlines. Winds will remain elevated at 10-20 kt which
will lead to wind chills 20-25 below north of the Hi-line Tuesday
morning, and 20-35 below everywhere Wednesday morning. Wind
chills continue for Thursday morning too. But with an upper ridge
beginning to build up in the West, wind chills should remain below
advisory level for Friday morning.
With the ridge comes a warm front where Pacific moisture rides
across the Divide. This overrunning moisture will find cold
conditions, which will possibly lead to accumulating snow through
An upper level disturbance dropping south from Canada has sent
limited moisture through Montana this morning and continues to
bring a few concentrated showers this afternoon.
TAF sites will be occasionally impacted with brief MVFR
conditions in a mix of rain and snow showers. Precipitation should
end by mid evening.
Winds: West or northwest around 15-25kts with a few higher gusts
with the passing showers.