Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 290533
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1033 PM MST Fri Nov 28 2014

Updated Aviation Discussion

.UPDATE...
Minor update to the forecast tonight to adjust POP with current
radar. Overall forecast remains in good shape. Cold air continues
to moves south through Central Montana and many locations are
around zero degrees across the plains. Expect snow to move in
through the night and linger through a good portion of Saturday.

&&

.AVIATION...
UPDATED 0533Z.
Arctic front now in the process of moving through the KHLN area will
continue with slower and less dramatic progress south through the
remainder of tonight, reaching the KBZN area Saturday morning.
MVFR/IFR ceilings will affect most of central/N-central MT through
Saturday. Snow will spread south and east across the region tonight
then gradually diminish from N-S Saturday afternoon with a period of
LIFR conditions possible at many terminals late tonight through
Saturday morning. Hoenisch

&&

.PREV DISCUSSION...
/ISSUED 430 PM MST Fri Nov 28 2014/

Tonight through Sunday...The leading edge of an Arctic cold front
has pushed into northern Montana, reaching Great Falls around 3pm.
High wind warnings have been canceled as the lee surface low
moves away and pressure rises rapidly behind the front. The front
has outpaced all model guidance by several hours and has a
temperature gradient nearing 30 degrees Fahrenheit over a few tens
of miles. Low clouds and areas of dense fog will develop soon
after frontal passage. Snow begins a few hours later, with around
1 to 4 inches of snow expected on the plains through Saturday
evening. Light freezing rain has been added in narrow band this
evening between Havre and LWT as suggested by model soundings.
Freezing rain would occur only for a brief time as cold air
quickly deepens behind the front.

A winter storm warming remains in effect for the Rocky Mountain
Front above 5000 feet where 8 to 14 inches of snow are expected
through Saturday evening. Winter weather advisories for snow and
blowing snow remain in effect for most other areas except southwest
Montana. The advisory start time for central Montana was moved up
given how quickly the front is moving through the state.

Wind chill values below -20F are expected tonight through Saturday
for our northwestern zones, and through Sunday morning in the
eastern Zones. Thus, wind chill advisories have been posted to
cover this hazard. Winds will taper from west to east on Sunday as
high pressure settles over the state. Nutter

Sunday Night through Friday...After a short period of very cold
temperatures, westerly flow aloft and southerly surface winds will
return, which will allow for rising temperatures. While there will
be a few weather systems bringing chances for snow to parts of the
area; at this time widespread significant cold or snow events are
not expected.

Long-range models are consistent on bringing a fast-moving
upper-level shortwave over the Treasure State that will bring
chances for snow to areas along the Continental Divide and southwest
Montana Monday night and Tuesday. Have raised PoPs to chance for
areas across southwest Montana, mainly south of MT-200. Also added a
slight chance of PoPs to central Montana. The next weather system
will bring another chance for light mountain snow across southwest
Montana on Wednesday and Thursday while westerly down-slope winds
keep areas across the north-central plains mainly dry. Temperatures
by the later half of the week will be around seasonal averages.
MLV

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  -5   0 -13  13 / 100 100  20   0
CTB -10  -5 -19  10 / 100  90  10   0
HLN  13  18  -7  16 /  70 100  50   0
BZN  28  35  -6  14 /  30 100  90   0
WEY  25  34  -1  19 /  70  90  80  20
DLN  33  41   5  16 /  30  70  70   0
HVR  -1   3 -13   7 /  90  70  10   0
LWT   4   6 -12  12 /  60 100  50   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...

WINTER WEATHER ADVISORY from Midnight tonight to Midnight MST
Saturday Night Broadwater...Cascade...Central and Southern Lewis
and Clark...Gallatin...Jefferson...Judith Basin...Meagher.

WINTER WEATHER ADVISORY until 5 PM MST Saturday Chouteau...
Eastern Glacier...Eastern Pondera...Eastern Teton...Liberty...
Toole.

WIND CHILL ADVISORY from Midnight tonight to 7 PM MST Saturday
Cascade...Eastern Glacier...Eastern Pondera...Eastern Teton...
Liberty...Northern Rocky Mountain Front...Southern Rocky
Mountain Front...Toole.

WIND CHILL ADVISORY from Midnight tonight to 11 AM MST Sunday
Blaine...Chouteau...Fergus...Hill...Judith Basin.

WINTER STORM WARNING until 5 PM MST Saturday FOR ELEVATIONS
ABOVE 5000 FEET FOR Northern Rocky Mountain Front...Southern
Rocky Mountain Front.

WINTER WEATHER ADVISORY until 5 PM MST Saturday FOR ELEVATIONS
BELOW 5000 FEET FOR Northern Rocky Mountain Front...Southern
Rocky Mountain Front.

&&

$$

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