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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
230 PM MST Fri Jan 30 2015

.DISCUSSION...

Tonight through Sunday...Clear and mild conditions prevail this 
evening with an upper level split flow over the region. A 
low-amplitude shortwave trof presently over British Columbia will 
move through central Montana on Saturday. The surface cold front 
associated with this feature will cross the International border 
around 09Z. Synoptic-scale dynamical support with low-level upslope 
flow will support snowfall across North Central Montana. Froude 
numbers support mid-slope snow accumulation based on local office 
research. Moisture is limited, and the system will move quickly. 
Therefore, expected snow totals are 1-3 inches over the plains with 
2-5 inches over the central mountains. The NAM-12 suggests banding 
possible on the north-facing aspects of the Little Belt and Highwood 
Mountains. A winter weather advisory has been issued to cover
travel impacts associated with this snowfall. Snow ends early
Sunday. The next wave approaches from the west late Sunday with
increasing PoPS over northern portions of the Continental Divide.
Nutter

Sunday night through Friday...Shortwave energy in a moist 
northwesterly flow aloft will bring a continuing chance for light 
rain and snow across the forecast area Sunday night and Monday. More 
widespread snow is expected over the western mountains but 
accumulations amounts do not look overly impressive at this time. By 
Monday night, however, models are in good agreement pushing another 
batch of cold Canadian air into central Montana along with periods 
of snow. This system will continue to move southward through the 
state with a band of precipitation gradually moving into southwest 
Montana by Tuesday night. For the remainder of the week, models are 
in relatively good agreement in building an upper level ridge over 
the northern Rocky Mountains. Temperatures are expected to warm back 
toward seasonal averages by Thursday with highs possibly climbing 
well above average by Friday. Breezy and mostly dry conditions will 
likely prevail at lower elevations with a chance for precipitation 
expected to persist over the western mountains as flow aloft 
squeezes out any moisture due to orographic lift. mpj

&&

.AVIATION...
UPDATED 1735Z.
Dry northwest flow aloft will continue with a few high clouds 
passing over the area. A disturbance aloft will approach the area 
after 06z resulting in increasing low and mid clouds. A surface cold 
front will also begin pushing south after 06z. Areas of snow will 
develop behind the front and continue through 00z Sunday. VFR 
conditions prevail with increasing MVFR conditions due to low 
ceilings and snow across northern Montana after 12z. 

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  25  28   8  34 /  10  90  30  10 
CTB  21  23   4  28 /  20  70  20  10 
HLN  19  31  11  34 /   0  50  20  10 
BZN  14  36  11  32 /   0  10  20  10 
WEY   7  34   7  27 /   0  10  20  20 
DLN  19  44  18  39 /   0   0  10  10 
HVR  21  26   3  23 /  30  90  30  10 
LWT  21  27   6  30 /   0  80  40  10 

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 5 AM Saturday to 5 AM MST Sunday 
Blaine...Cascade...Chouteau...Fergus...Hill.

&&

$$

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