Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 171019

Area Forecast Discussion
National Weather Service Billings MT
319 AM MST Sun Feb 17 2019

.SHORT TERM...valid for Tdy and Mon...

Light snow was occurring across much of the area early this
morning per radar and surface observations. Visibilities have
remained above 1 mile since the evening hours for most areas. Cold
advection over the area has caused the dendritic growth zone to
become shallow which has limited the size of the snowflakes. Upper
low/inverted trough located from SE MT to NE will pull ESE away
from the area through the day. This loss of lift will cause snow
chances to decrease through the day into tonight from W to E. QPF
and snow ratios supported additional accumulations from a half
inch to an inch from KBIL to KSHR W, to 1 to 2 inches over SE MT
through tonight. No changes to the ongoing snow highlights which
end at 18Z today. Wind chills will be a concern through midday in
the NW and E. The wind chill issues were already covered by the
existing highlights. Areas of blowing snow will continue over
portions of the region.

Highs today will be mainly in the single digits due to clouds,
snow cover and 850 mb temperatures around -20 degrees C. 850 mb
temperatures will fall a few more degrees tonight. Under the
arctic high and with fresh snow cover, expect lows in the single
digits below zero to the teens below zero. A vorticity lobe will
move into the W Monday and Mon. night, bringing a chance of snow
to the SW mountains. The cold airmass will continue over the
region, with highs on Mon. in the single digits, and lows Mon.
night in the teens below zero over much of the area. Arthur

.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...

A messy upper level pattern will be in place for a large part of
the week. The general theme of a trough over the northern Rockies,
remains in place, but the details need to be cleaned out as far
as energy dropping into the trough and generating potential lift
for snow chances. A piece of energy drops into northern Wyoming
and cuts off a weak low Tuesday night into Wednesday. This system
will be starved for moisture, with the strongest energy and
moisture staying well to the south, limiting snow chances.

Another trough drops into place Thursday and Friday. This system
will bring with it a quick punch of cold air, and will have a
little better chance of producing some light snowfall. This system
too will split, with the strongest energy diving well to the
south, so will keep snow chances down at this point.

A warming trend is expected Tuesday and Wednesday, but
temperatures will still remain well below seasonal averages.
Thursday into Friday will bring a quick cool down, before warmer
temperatures try to build back in for next weekend. TWH


Light snow will continue this morning, before decreasing in
coverage this afternoon. Locations from KBIL to KSHR will
experience MVFR conditions, with occasional IFR conditions in
heavier snow. Locations east of KBIL and KSHR will be left with
IFR with occasional LIFR conditions in snow and fog. VFR
conditions will develop late this afternoon, as the snow tapers
off. Mountains will be obscured. TWH


    Tdy Mon     Tue     Wed     Thu     Fri     Sat
BIL 008 910/005 910/021 006/027 008/020 002/018 004/027
    7/S 31/E    10/U    00/B    24/S    21/B    01/B
LVM 013 905/011 903/022 009/024 009/019 001/020 007/026
    4/S 21/E    10/N    03/S    24/S    21/B    01/B
HDN 007 912/006 913/020 001/027 003/020 001/019 000/026
    7/S 21/E    10/U    00/B    14/S    21/B    10/B
MLS 004 908/004 916/013 903/020 001/017 902/014 902/019
    7/S 51/E    10/U    00/U    12/S    21/E    00/B
4BQ 006 910/006 914/019 000/025 002/021 001/019 002/026
    6/S 31/E    10/B    00/B    02/S    21/E    10/B
BHK 006 907/005 915/013 902/018 001/017 902/014 000/019
    9/S 72/S    10/B    00/U    02/S    11/E    10/B
SHR 009 910/008 907/021 002/028 005/023 005/021 004/029
    6/S 41/E    10/U    00/B    13/S    31/B    01/B


MT...Wind Chill Advisory in effect until noon MST today FOR ZONES
     Winter Weather Advisory in effect until 11 AM MST this
      morning FOR ZONES 30-31-58.
     Winter Storm Warning in effect until 11 AM MST this morning
      FOR ZONES 32-33-36-37.


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