Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 242343
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
540 PM MST Tue Jan 24 2017

Aviation Section Updated.

.DISCUSSION...

This afternoon through Thursday...The region will continue to
under the influence of an upper trough with embedded waves moving
south to southeast mainly across western and southwest MT. With
these disturbances and plentiful moisture in the dendritic growth
zone across southwest MT, light snow will be possible at times
particularly at higher elevations. However, impactful snow
accumulations are not expected. Over the Plains, a drier low-level
flow will begin to develop tonight over top of a shallow near-
surface inversion. In areas where there is still snow cover, this
may allow for the formation of patchy fog to develop tonight.

Drier conditions continue to develop through Wednesday into
Thursday, with a slight warming trend as west surface winds
gradually increase. Skies will also trend toward the clear side
over the Plains as high pressure ridging builds over the region,
with valley inversions particularly over the SW valleys
potentially contributing to clouds, fog, and/or air quality
concerns by Thursday morning.  Cassell

Thursday night through Tuesday...Quiet conditions to start the
long term...with perhaps a more active pattern returning early
next week. Ridge of high pressure will dominate our weather
pattern to start the long term. Mainly dry conditions...with a few
clouds...and a gradual warming trend are expected through
Saturday. Sunday we see the ridge flatten and strong westerly flow
is expected for the region. The northern half of the CWA may see
breezy to windy conditions at times. With 700 mb winds near 50
Knots...will have to monitor for potential high wind products. Our
long range models then differ on what happens early next week.
Both showing a clipper system may move across Montana in some
capacity. GFS much more aggressive than recent model runs.
Bringing a sharp cold front across the region Sunday night through
Monday...lingering into Tuesday morning. This would hint at
scattered light snow and colder temperatures to much of our CWA.
Meanwhile the Euro solution has this clipper as more of a glancing
blow..with little precip. Introduced some slight chances for snow
Sunday night through Tuesday morning...although will have to
monitor the exact track of this clipper system. As mentioned
temperatures will be on a gradual warming trend through Sunday.
Warm downsloping air could even bring high temperatures in the low
to mid 40s for the plains of northern Montana on Sunday. The
mentioned cold front then cools down temps for Monday into Tuesday
to near normal readings. Anglin

&&

.AVIATION...
Updated 2340Z.
VFR conditions prevail across most of the region this evening,
except for variable MVFR under patchy stratus over portion of N-
central MT. Drier air is advecting in from the north, so expect
thinning to SCT mid/high clouds overnight into Wednesday. Areas of
ground fog remain possible especially along central and eastern
portions of the Hiline including KHVR. PN

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  10  27  12  30 /  10  10  10  10
CTB   7  28  14  32 /  10  10   0  10
HLN   6  23   6  22 /  10  10  10  10
BZN   2  19   1  18 /  10  10  10  10
WEY -13  16  -9  14 /  10  10  10  20
DLN   2  22   4  21 /  10  10  10  10
HVR   9  23   8  28 /  10  10   0   0
LWT   9  25  10  27 /  20  10  10  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/greatfalls


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