Area Forecast Discussion
Issued by NWS Great Falls, MT

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102
FXUS65 KTFX 191027
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
327 AM MST Fri Jan 19 2018

.SYNOPSIS...
Areas of light snow will continue to affect southern portions of
Central Montana this morning and most of Southwest Montana today
and tonight. Cooler temperatures will prevail through the weekend
and into next week with a chance of snow showers continuing along
the Continental Divide.

&&

.DISCUSSION...

Today through Sunday...Upper level disturbance continues to bring
light rain and snow (and a few areas of freezing rain) to southern
portions of Central Montana and much of Southwest Montana. This
feature will continue moving to the southeast with precipitation
tapering off in Central Montana but continuing overnight in
Southwest Montana. Core of the upper level trough will remain well
south of Montana through the weekend with generally weak west to
northwest flow aloft prevailing over the Northern Rockies. Breezy
westerly winds will allow mostly dry and cool conditions to
continue over the plains but a chance for precipitation will
linger over the Continental Divide. mpj

Sunday night through Friday...Medium range models are in decent
agreement suggesting that a progressive flow aloft will prevail
over the region through much of next week. Period will start off
with a closed upper level low over the Southern Rockies and
shortwave ridging over Montana. The closed low will lift
northeastward into the Midwest while Montana is expected to see a
series of weak shortwave troughs and ridges pass through the
region through midweek. Abundant Pacific moisture will bring
periods of snow to the western and Southwest Montana mountains
while isolated showers occasionally move out over the plains. From
Wednesday through Friday the region will see a transition to
cooler temperatures as a broad upper level trough moves inland
over the western USA. Models continue to suggest that bulk of
energy associated with this trough will remain mainly south of
Montana but this will continue to be watched for any signs of
models trending further north over the coming days. mpj

&&

.AVIATION...
Updated 0600Z.

Upper level disturbance and its associated cold front will
continue to bring rain and/or snow showers from about KGTF to
KLWT and southward through tonight. MVFR to IFR conditions are
possible with any shower activity. Meanwhile areas north of this
line should see cloudy and generally VFR conditions tonight
through the day Friday. Shower activity shifts slightly southward
for Friday...however...most the same areas mentioned will still
see chances for MVFR to IFR snow showers. Some areas across sw MT
may even see a brief break in activity Friday morning before a
second round of showers comes later Friday morning into the
afternoon hours. Precipitation will then go on a diminishing trend
Friday evening. Mountains will be obscured for most of the
forecast period. Areas that see rain will have the potential for
freezing level just off the ground...possibly creating some icing
potential. LLWS is also a possibility for most sites along the
frontal boundary...although confidence was to low to include.
Anglin

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  37  26  35  20 /  20  10   0  10
CTB  36  26  35  19 /   0  10  10  10
HLN  31  14  27  10 /  40  10  10  10
BZN  31  10  26   7 / 100  30  10  10
WEY  33   4  24  -3 / 100  60  10  10
DLN  33  15  26   9 /  60  20  10  10
HVR  33  20  29  11 /  10  10   0  10
LWT  32  19  32  15 /  60  10   0  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 AM MST this morning
Broadwater...Cascade...Central and Southern Lewis and Clark...
Jefferson...Judith Basin...Meagher.

Winter Weather Advisory until 11 AM MST this morning
Beaverhead...Gallatin...Madison.

&&

$$

http://www.weather.gov/greatfalls



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