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Area forecast discussion 
National Weather Service Great Falls Montana
1018 am MST sun Dec 28 2014

Update...

The current forecast is on track as widespread snow continues over
north-central and much of southwest Montana. Snow should reach
areas in far southwest Montana by early this afternoon and begin
tapering over far north-central Montana later this afternoon and
early evening. Additional snowfall amounts of 2 to 5 inches are
expected through tonight in lower elevations with an additional 4
to 8 inches in the mountains at and above pass level. Mlv

&&

Aviation...
updated 1718z.
A surface cold front will continue to move south across the area
through the afternoon. Widespread snow along with gusty north winds
will accompany the front. Widespread MVFR/IFR conditions are
expected through the night and mountain obscuration is expected.
Conditions will improve slowly Monday.

&&

Previous discussion...
/issued 450 am MST sun Dec 28 2014/
Sunday through Tuesday...snow continues to increase in coverage
this morning and will fall across central Montana through the
day. Snow totals look very similar to the last storm with amounts
highest over the Continental Divide. The best period for seeing
heavy snowfall looks to be Sunday morning. Most moisture exits the
region early Monday morning but some light snow showers may
linger into the day Monday. Skies begin to clear from the north
Monday night as very cold temperatures move into the region. With
clearing skies and fresh snow, the possibility of widespread low
temperatures around 20 degrees below zero exists Tuesday morning.

Tuesday night through Sunday...the medium range period begins with a
strong upper ridge over the eastern Pacific and a closed upper low
over northern California/western Nevada. The resulting northerly
flow aloft over the area will be dry but cool and will continue
through Wednesday. By Thursday, weak shortwave energy rounding the
top of the upper ridge, along with a plume of moisture, will bring
light snow to the hi-line. Pacific moisture will override the cool
air-mass east of the Continental Divide on Friday resulting in a
large area of snow that will continue into Saturday. Another push of
cold air into the area Sunday will allow scattered snow showers to
continue. Temperatures will remain well below seasonal averages.
Lows Saturday and Sunday will be below zero for most of northern and
north central Montana. GFS model hinting at very cold readings
Monday morning.

&&

Preliminary point temps/pops...
gtf 27 -8 2 -22 / 100 70 10 10
ctb 24 -11 -2 -26 / 100 30 10 0
hln 22 -1 7 -19 / 100 40 20 10
bzn 21 -6 9 -19 / 100 70 20 10
wey 23 -5 15 -19 / 100 80 40 20
dln 24 0 10 -12 / 100 40 10 10
hvr 20 -3 6 -18 / 90 20 10 0
lwt 23 -5 5 -19 / 100 70 20 10

&&

Tfx watches/warnings/advisories...
Winter Weather Advisory until 6 am MST Monday Beaverhead...
Blaine...Broadwater...Cascade...central and southern Lewis And
Clark...Chouteau...eastern Glacier...eastern Pondera...eastern
Teton...Fergus...Gallatin...hill...Jefferson...Judith Basin...
Liberty...Madison...Meagher...Toole.

Winter Storm Warning until 6 am MST Monday Beaverhead...northern
Rocky Mountain front...southern Rocky Mountain front.

Winter Storm Warning until 6 am MST Monday for elevations above
6000 feet for Cascade...Judith Basin...Meagher.

&&

$$

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