Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 221044
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
344 AM MST Sat Nov 22 2014

.DISCUSSION...

Today through Monday...Today will be an active weather day as a
surface cold front sweeps through the state. Southerly winds are
already increasing ahead of the front and causing favored
locations in southwest Montana to gust above high wind criteria.
Have expanded the High Wind Warning for Norris Hill to cover all
of Madison, Gallatin and Broadwater Counties through mid
afternoon. Once the front pushes through the region, winds will
shift to the west which will not be as favorable for high winds.
Have also expanded the High Wind Warning to include much of
central Montana as well. Winds in this area will likely increase
just ahead of and behind the front so this portion will begin
later this morning and continue through later this evening.
Temperatures across central and north central Montana have not
cooled off as much as models suggested over the last few days so
have cut back the coverage of freezing rain significantly for this
morning and confined it to mainly far northern Blaine and Hill
Counties. Have not made any changes to the existing Winter Weather
Advisories as mountain snows continue to appear favorable for much
of today and tonight. Heavier snow on the very highest peaks could
approach Winter Storm Warning criteria but coverage is limited so
opted to keep advisory as is. Cooler and unsettled conditions will
prevail for Sunday and Monday but at this time it does not appear
that any type of highlights will be required. mpj

Monday night through Saturday...Unsettled weather continues into the
long term forecast as Northwesterly flow aloft will allow for some
instability to move across the area Monday night and Tuesday.
Confidence remains low as models begin to diverge over temperatures
into the Thanksgiving weekend. Confidence is increasing that
temperatures will more likely be near seasonal averages. The GFS
operational model continues to try and push another cold air system
over the area, however the ECMWF and GEM continue to move a large
scale ridge over the Rocky Mountains and effectively shield most of
the area from the colder temperatures. Another interesting model
solution is the 13km GFS, while still experimental it also is
showing the high pressure ridge over the area by Thanksgiving. While
this model is not in the official suite its solution is helping
build confidence in the "warmer" of the two solutions. Have
therefore trended the forecast in that direction, with a stronger
nudge towards the ECMWF solution for temperatures and precipitation
through the long term. Some decent snowfall amounts are expected in
the higher terrain at this time with the system moving into the area
while highlights are not anticipated at this time, the precipitation
occurring leading up to the Thanksgiving holiday weekend could
impact travel plans and should be closely monitored by potentially
affected parties. Suk

&&

.AVIATION...
UPDATED 0540Z.
Strong west flow aloft will strengthen further during the night
ahead of a low pressure trof over the West Coast. A cold front will
cross the Rockies early Saturday morning and spread east during the
day. Snow, mountain obscuration, and IFR/LIFR conditions are likely
at higher elevations later tonight and Saturday. Elsewhere, VFR
conditions will prevail, except with possible MVFR in rain showers.
Very strong and gusty winds will also be associated with and after
frontal passage, and gusts in excess of 60 kts are expected over and
along the lee slopes of the Rockies. Zelzer/Nutter

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  45  26  40  25 /  20  10  10  20
CTB  41  23  38  21 /  20  20  10  20
HLN  46  28  40  25 /  50  20  20  30
BZN  42  19  35  16 /  80  20  20  30
WEY  31  12  26   6 / 100  70  50  80
DLN  40  19  33  16 /  80  20  20  20
HVR  45  25  35  20 /  30  30  20  20
LWT  47  26  37  23 /  40  30  20  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 9 AM this morning to 10 PM MST this
evening Cascade...Chouteau...Eastern Glacier...Eastern Pondera...
Eastern Teton...Fergus...Judith Basin...Liberty...Toole.

WINTER WEATHER ADVISORY until 5 AM MST Sunday Beaverhead...
Gallatin...Madison.

WINTER WEATHER ADVISORY until 5 AM MST Sunday For US 89 over
Kings Hill Pass.

HIGH WIND WARNING until 2 PM MST this afternoon Broadwater...
Gallatin...Madison.

WINTER WEATHER ADVISORY until 5 AM MST Sunday Central and
Southern Lewis and Clark...Northern Rocky Mountain Front...
Southern Rocky Mountain Front.

HIGH WIND WARNING until 10 PM MST this evening Central and
Southern Lewis and Clark...Northern Rocky Mountain Front...
Southern Rocky Mountain Front.

&&

$$

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