Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 071044
Area Forecast Discussion
National Weather Service GLASGOW MT
344 AM MST Wed Dec 7 2016
.SHORT TERM...for northeast Montana...today through Fri...
Wind Chill Advisory continues for this morning. Stacked low
pressure system over western Ontario still producing strong
northwest winds to northeast Montana this morning. The wind will
continue to result in areas of blowing and drifting snow, and combined
with the near to sub zero temperatures, bitter wind chills.
Winds are expected to ease slightly today before becoming light
tonight as high pressure slides down the front range. Skies should
clear to the west but position of the high will keep some clouds
over the east. Cold air lingers over the region and even with the
lighter winds, wind chills could approach 20 below again tonight.
The large temperature difference between the air and the surface
of Fort Peck Lake will continue to generate lake effect clouds and
possibly light snow through Thursday. Currently stronger northwest
winds are streaming the clouds across McCone county but as the
winds diminish the lake effect will move closer to the lake and
could become more intense.
By Thursday night a slight upper ridge begins to develop over the
state. The Canadian high pressure moves east and warmer air
spreads across the divide. Pacific moisture will overspread the
lingering cold air on Friday for an overrunning snow event during
the day. Ebert
.LONG TERM...Fri night through Wed...
As a shortwave ridge departs the area, expect a shortwave trough
to quickly push through the CWA Friday night into Saturday. A
little light snow is expected with the increased forcing for
ascent moving through the region. Given 0.1" of QPF or so along
with expected snow to water rations, the area can expect up to an
inch or two of snow accumulation with this system, with the better
chances south of the Missouri River. Location and amounts may need
to be refined some in future shifts, so those with interests in
the area should monitor the latest forecast.
Fairly progressive northwest flow aloft looks to continue into the
new week while a ridge builds across the eastern Pacific and a
large trough with closed low remains situated over Hudson Bay.
Shortwaves will continue to march through the Rockies and into the
Northern High Plains producing periods of light snow through the
extended, along with reinforcing pushes of Arctic temperatures. In
fact, given that 850mb temperatures remain near -20C for much of
the long range, lows near or below zero with highs in the single
digits above zero will remain common.
As is typical, ensemble spread in the 500mb heights increases at
larger time scales and so it becomes difficult to forecast snow
timing and location with any precision for next week. However, as
time unfolds model consensus should improve, leading to the
ability to provide more forecast detail. Maliawco
VFR conditions are expected to prevail for area terminals today,
though mid level clouds will remain present. Gusty northwest
winds will continue at 10 to 20 kts. Maliawco
Wind Chill Advisory until 11 AM MST this morning for Central and
Southeast Phillips...Central and Southern Valley...Daniels...
Sheridan...Southwest Phillips...Western Roosevelt...Wibaux.