Area Forecast Discussion
Issued by NWS Great Falls, MT

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809
FXUS65 KTFX 192219
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
319 PM MST Sun Feb 19 2017

.DISCUSSION...

Tonight through Monday...Skies are generally clearing across the
forecast area this afternoon with subsidence following the passage
of a shortwave trough. Scattered rain and mountain snow showers
linger over the forecast area but are expected to dissipate while
exiting to the northeast this evening. Additional new convection
is observed upstream over Idaho. Some of this activity could move
into the western and southwest mountains during the evening hours.
Subtle ridging aloft with weak warm advection maintains generally
fair and mild weather for Monday.

Monday night through Wednesday..Another atmospheric river sends a
surge a Pacific moisture into the region amid a strong southwest
flow aloft. Most of the accumulating rain and mountain snow will
remain along and west of the Continental Divide, though areas of
light precipitation are expected to move across central Montana at
times. A period of strong winds are expected Tuesday afternoon
across much of central, southwest and south-central Montana. This
is a somewhat atypical path for strong winds as the surface low
tracks through North-central MT with a lightning of the 700 hPa
gradient. If this feature arrives during the daytime, boundary
layer mixing will help bring these strong winds to the surface.
Temperatures trend cooler on Wednesday as this system weakens and
cooler air begins to move into the Pacific Northwest.

Wednesday night through Sunday...A northerly flow develops
bringing a return to more normal late-winter temps areawide. This
northerly flow will likely be accompanied by enough moisture for
periods of snow at times through next weekend.
PN

&&

.AVIATION...
Updated 1800Z.

An upper level disturbance and its associated surface front are
moving through North-central and Southwest MT this afternoon. Areas
of rain and snow associated with this system will produce periods of
MVFR and temporary IFR, most likely at KEKS/KBZN/KLWT and KHVR.
Mountain obscuration is likely at times near these terminals. There
exists a low confidence possibility that VCSH over the mountains
near KEKS and KBZN could carry isolated lightning activity and
enhanced turbulence.  Skies clear with VFR conditions prevailing
overnight. Clouds increase again from the west and southwest mid-
day Monday. PN

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  32  52  39  54 /  20  20  20  30
CTB  27  43  31  44 /  10  10  20  40
HLN  23  43  30  46 /  30  30  40  30
BZN  23  43  32  47 /  40  40  50  40
WEY  19  35  31  37 /  70  90  90  90
DLN  26  43  36  46 /  20  40  60  40
HVR  30  50  34  51 /  20  10  10  40
LWT  29  52  36  55 /  30  20  20  30

&&

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

$$

weather.gov/greatfalls



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