Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 192219

Area Forecast Discussion
National Weather Service Billings MT
319 PM MST Mon Feb 19 2018

.SHORT TERM...valid for Tue and Wed...

Light snow continued across portions of southeast Montana into the
mid afternoon with areas of flurries as far west as Yellowstone
County. Dynamic support aloft will continue to slide slowly
southeast this evening and overnight. So we look for precipitation
winding down from west to east overnight. The southeast corner up
into Fallon county are the only areas which may see around an
additional inch of snow from late afternoon through the night.
Other locations will see flurries to maybe a dusting of new snow

The trof axis finally slides by us Tuesday morning. Our main
forecast issue is potential wind chills early tomorrow. Model
progs are slow to dissolve the cloud cover overnight, but do
suggest sky cover will begin to break up toward 12Z in the western
CWA. At that time we see winds shift to the southwest late tonight
and pick up a bit hitting 7-12 kts. As a result, it appears wind
chills by sunrise may be 20 to 30 below zero over our western CWA.
Course this is an issue for children waiting for buses etc. We
will issue a wind chill advisory from midnight to noon Tuesday for
these areas. Areas further east will have less wind and air
temperatures may not bottom out thanks to lingering low clouds.
Highs on Tuesday will be mainly single digits above zero.

Lower elevations will remain dry Tuesday through Wednesday.
However, the flow aloft remains cyclonic and proggs show some
energy dropping south out of Canada into the Northern Rockies.
This may generate some snow showers over our western mountains
Tuesday night into Wednesday, but this should be of little
relative impact or accumulation. Look for another cold night
Tuesday night and highs on Wednesday still only in the single
digits and teens. BT

.LONG TERM...valid for Thu...Fri...Sat...Sun...Mon...

Only minor changes to the extended forecast this afternoon, as
mainly dry conditions and below average temperatures persist
through the latter portions of workweek.

Several reinforcing trofs in western CONUS will keep high
temperatures from rising very quickly through the work week, only
reaching mid 20s by Friday. Meanwhile, low temps a few degrees
above and below zero are expected through Friday. Temps will Jump
into the mid 30s on Saturday, as downslope flow develops ahead of
an approaching weather maker for Sunday evening and Monday.

Western mountains looks good for additional snow into the Cooke
City area through the latter portions of the workweek, as moisture
continues to stream into the region. Models continue to advertise
mainly dry conditions over the lower elevations until
Sunday/Monday time frame. Would not be surprised to see a few
light snow showers slipping off the mountains at times, but would
not anything of significance. AAG



VFR/MVFR conditions prevail across the west and northwest this
afternoon, with IFR and localized LIFR conditions across the south
and east. Widespread IFR conditions expected through at least
early afternoon with light snow continuing. Conditions are
expected to continue to improve from northwest to southeast
through the evening as the storm system moves out of the area.
Cloud cover may be slow to clear, and could hang around in the
east through mid day Tuesday, although VFR conditions should
prevail before that point. AAG



    Tue     Wed     Thu     Fri     Sat     Sun     Mon
BIL 910/006 910/013 907/020 901/027 012/034 016/033 013/034
    41/U    01/B    01/U    11/U    12/J    22/S    21/B
LVM 916/010 905/017 901/023 005/029 016/036 018/034 015/036
    21/U    01/B    11/B    11/B    13/J    43/S    22/S
HDN 916/006 914/012 909/020 907/025 007/033 012/031 009/034
    41/U    00/B    00/U    11/U    01/B    22/S    21/B
MLS 909/003 916/007 912/014 909/018 004/027 007/025 005/029
    51/B    00/U    00/U    10/U    01/B    11/B    21/B
4BQ 910/003 918/011 911/018 907/023 006/030 011/029 009/033
    71/B    00/U    01/U    11/U    01/B    11/B    21/B
BHK 909/003 914/009 911/018 908/018 005/028 009/026 004/029
    71/B    00/U    00/U    10/U    01/B    11/N    21/B
SHR 915/006 917/013 909/021 906/027 006/033 012/032 008/034
    51/B    00/U    01/U    11/U    01/B    21/B    21/B


MT...Wind Chill Advisory in effect from midnight tonight to noon
      MST Tuesday FOR ZONES 28-29-34-35-40>42-63-65-66.
     Winter Weather Advisory in effect until 11 PM MST this
      evening FOR ZONES 36-37.


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