Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 102147
Area Forecast Discussion
National Weather Service GLASGOW MT
247 PM MST Sat Dec 10 2016
.SHORT TERM...for northeast Montana...tonight through Mon...
The Winter Weather Advisory (WSW) in place over Northeast Montana
today is the result of the energetic short-wave trough currently
swinging through the region. This wave was accompanied by Pacific
moisture overriding very cold surface temperatures. The wave
progresses through the area tonight and exits the area after
sunrise. That is near when the WSW is set to expire. Sunday will
see a weak ridge become zonal flow for a mostly dry day. Then
Sunday night and Monday an Arctic trough dips south into
Saskatchewan, which when combined with addition zonal flow and
embedded moisture and disturbances will bring light snow and gusty
northwest winds that will add more wind chills to the mix. Snow
amounts will likely be less than advisory levels.
Tonight additional snow is expected, mainly over the eastern zones
and very light elsewhere. this should bring snow totals to around
2-4 inches. Winds are expected to be light and variable so as not
to be a wind chill issue.
Sunday light winds continue. With the weak ridge/zonal flow,
there will be a slight improvement in temperatures, but still
roughly 20F degrees below normal.
Sunday night and Monday the new Arctic front pushes south over the
area to bring in much colder air aloft. Initially the push will
kick off light snow showers. Some accumulating snow is expected by
Monday morning but it will continue south of Nemont and end by
noon Monday locally. A closed surface low parked over Hudson Bay
will energize northwest winds enough to possibly require an
advisory for wind chills. Wind strength will likely be sufficient
to go ahead and add patchy blowing snow for Monday afternoon.
.LONG TERM...Mon night through Sat...
Tuesday and Wednesday: Polar Vortex over south central Canada will
bring a very cold Arctic high pressure southward along the east
side of the Canadian Rockies and into Northeast Montana with
mainly dry weather.
The cold temperatures and dry conditions will continue into
Thursday with single digit high temperatures and single to double
digit negative low temperatures.
A storm system moves inland from the Pacific on Thursday and
moves into Western Montana, Idaho, and Wyoming.
A reinforcing Arctic cold front drops south out of Canada Friday
with highs struggling to make it to zero. Mean while the storm
system is forecast to effect the central rockies and Wyoming
Friday with snow spreading northward into northeast Montana along
and south of the cold front. There is a good deal of uncertainty
with this weather situation late next week so stay tuned for more
updates to follow over the next several days. Saturday could
possibly see very cold...breezy and dry conditions. Tomc
Snow dvlping and filling in over NE MT...quickly spreading east
to the North Dakota boarder. MVFR Conds deteriorating to IFR into
CIGS/VSBYS improve to MVFR from west to east tonight mainly after
midnight as system moves E into the Dakotas.
WINDS: East 10-15 kts today turning NNW 4-8KTS tonight and Sunday
morning...then WSW Sunday afternoon.
Winter Weather Advisory until 5 AM MST Sunday for Central and
Southeast Phillips...Central and Southern Valley...Daniels...
Sheridan...Southwest Phillips...Western Roosevelt...Wibaux.