High Wind in Montana, December 16, 2019

Area Forecast Discussion
National Weather Service Great Falls MT
445 PM MST Mon Dec 16 2019

UPDATED AVIATION

.SYNOPSIS...Breezy to windy conditions will continue along the
Rocky Mountian Front and North-central Montana for much of this
week. Areas of blowing snow will cause reduced visibility at times
through Tuesday afternoon. Along with gusty winds will come a
warming trend pushing highs into the forties for many locations as
the week progresses.

&&

.DISCUSSION...

Remainder of this afternoon through Tuesday night...A north to
northwesterly flow continues aloft as a shortwave moves southeast
and exits the CWA. A tightening gradient along the Rocky Mountain
Front and Central Montana mountains will continue to support gusty
winds through Tuesday morning. Winds over the Northern Rocky
Mountain Front and Eastern Glacier County are still expected to
approach High Wind Warning criteria tonight into Tuesday morning
so no changes were made to the High Wind Warning, which is set to
begin at 0Z today. Also, the Winter Weather Advisories issued to
address the blowing/drifting snow over the Rocky Mountain Front,
Judith Basin, Eastern Cascade, Glacier and Pondera Counties remain
unchanged. Areas where the snow hasn't compacted and gusty winds
are present, may see some reduced visibilities and snow drifting
onto roads, causing some impacts to travel. During the day on
Tuesday, the pressure gradient relaxes somewhat but winds aloft
will keep the breezy conditions going for much of the remaining
week. Most areas are expected to be dry but areas along the
immediate eastern slopes of the Northern Rocky Mountain Front can
see some light snow overnight tonight.

Wednesday through Monday...Late Wednesday into Thursday, a
passing disturbance will usher in a period of moist westerly flow
across the Northern Rockies. This is expected to result in periods
of snow developing along the immediate eastern foothills of the
Rocky Mountain Front from late Thursday through Saturday. It's a
little early to get into snowfall amounts but this area will be
monitored for potential winter highlights in the next couple of
days. Otherwise, continued downslope winds along with an
increasing influence of high pressure aloft will favor a continued
warming trend pushing high temperatures into the 40s to near 50
for most lower elevation locations by Friday and Saturday. Surface
winds may approach high wind criteria over the Rocky Mountain
Front and the north-central Plains during this period, especially
on Friday. The aforementioned high pressure area begins to break
down later Sunday into Monday, which will lead to cooler
temperatures and an increased chance for precipitation.

&&

.AVIATION...
Updated 445 PM MST Mon Dec 16 2019 (00Z 12/17 TAF period)

Windy conditions will continue through Tuesday morning along the
Rocky Mountain Front and across the adjacent plains of north central
Montana today into tonight. This could yield some areas of
blowing/drifting snow for the Hi-Line terminals including KCTB and
KHVR. KHVR may have some periods of visibility reductions due to
blowing snow. Strong winds aloft will also produce scattered low
level wind shear and turbulence aloft. Mountains will be obscured at
times, however terminals will remain dry. KWYS may have areas of fog
early Tuesday morning. MLS

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  27  42  29  42 /   0   0   0   0
CTB  26  39  25  38 /   0   0   0   0
HLN  18  36  16  38 /   0   0   0   0
BZN   8  32   9  37 /   0   0   0   0
WEY  -1  19  -1  27 /  20  10   0   0
DLN   6  25   7  31 /   0   0   0   0
HVR  21  36  25  38 /   0   0   0   0
LWT  20  40  25  43 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 PM MST Tuesday Northern Rocky
Mountain Front...Southern Rocky Mountain Front.

Winter Weather Advisory until 11 AM MST Tuesday Cascade...Judith
Basin.

Winter Weather Advisory until 5 AM MST Tuesday Eastern Glacier...
Eastern Pondera...Toole.

High Wind Warning until 9 AM MST Tuesday Eastern Glacier...
Northern Rocky Mountain Front.

&&

http://www.weather.gov/greatfalls