Winter Storm in Montana, February 2 to 4, 2019

Area Forecast Discussion...Updated
National Weather Service Billings MT
859 PM MST Sat Feb 2 2019

.UPDATE...
Cold front has pushed into Judith Gap and temperatures have
fallen from the mid 40s early this evening to the teens this hour
there. Front should push into Billings by around 10 pm. Adjusted
temperatures to account for frontal timing. Adjusted PoPs a bit
as radar was filling in north and east of Billings. Latest model
runs have the bulk of the heavier snow occuring later tonight and
into the early part of the day Sunday. Current highlights look
good. TWH

&&

.SHORT TERM...valid for Sun and Mon...

Strong cold front moving southward through northern Montana driven
by northerly flow aloft over northwest Canada while southwest flow
aloft over southern Montana keeping mixed conditions and producing
gusty winds along the foothills. Front is expected to move through
the forecast area between 8 PM and 2 AM though it may slow as it
begins to move through Sheridan County Wyoming. Upslope and moist
air allows light snow to be produced by the arctic but expect
intensity to pick up as a shortwave tracks into the area Sunday
morning. 700mb inflection from this wave generally follows a track
from Dillon to Lewistown which means the better lift for heavier
snow will be north of and along the Musselshell River. Current
forecasts have zeroed in on this area for the highest
accumulations through Sunday night with much lighter shots of snow
coming across on Monday.

Just as important as the snow is how cold the airmass is behind
the front and how the region will see single digit temperatures at
best Monday into midweek with near double digit below zero low
temperatures. This change occurs quickly and temperatures in the
mid 50s this afternoon will fall into the teens by Sunday morning.
This is supported by a window of strong northerly winds so the
snowfall will be associated with a fair amount of blowing snow
through the day on Sunday. Snow will still blow Sunday night as
snow ratios increase in the cold air so even though snow will be
decreasing it will still be blowing around reducing visibility.
Also the falling temperatures will begin producing dangerous wind
chills Sunday night. Winter highlights currently in effect look
good with having adjusted Judith Gap to start at 8 pm.

A couple of areas look to provide local challenges as the terrain
begins to impact the movement of the cold air as it begins to
slow. Some areas along the foothills with higher elevation may see
some rain this evening before the cold deepens up enough to change
to snow. Could be some icy spots that develop as a result. Another
area that may not see as deep a cold air is Cooke City but the
moisture is progged to remain deeper as it does not dry out so
heavier snow amounts are possible. Last spot that seems to be a
challenge is Sheridan which could see the cold air held up a bit
by mountain wave activity so the change to much colder could be
delayed until daybreak Sunday. borsum

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

For Tuesday into next weekend, the pattern is indicating very
cold temperatures and snow flurries into next weekend. There is a
persistent moist southwest flow that will bring a steady snowfall
to the Beartooth Mountains. Cooke City has a potential of
receiving significant accumulations over the next week. The
plains will also see periods of snow flurries but will accumulate
to an inch or less each day of the period. The best chance for
snow showers in Billings is going to be Tuesday into Tuesday
night.

Cloud and snow cover are going to be the challenge of this
forecast as any break in the clouds could drop temperatures lower
than currently forecasted. The amount of snow cover that is
received will also vary those temperatures and potentially lower
them as well. Winds appear to be light during this period.

High temperatures for Tuesday and Wednesday will struggle to get
out of the single digits for much of the area. Moving into
Thursday and into next weekend temperatures will warm up into the
teens with some locations reaching the low 20's. Lows will drop to
below zero through the end of the week. Carrothers

&&

.AVIATION...

A cold front moving through KLVM and KBIL by 04z and KSHR by 10z will
shift winds to north. There could be gusts 20 to 30 knots as the
front moves through. Ceilings will drop to IFR conditions behind
the front as snow develops. Localized conditions could drop to
VLIFR with the heavier snow. Reimer

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 012/016 909/003 906/005 908/007 907/018 001/020 001/017
    89/S    73/S    24/S    52/S    10/B    01/B    11/E
LVM 022/028 003/020 010/020 003/018 000/024 007/026 008/025
    89/S    74/S    36/S    42/S    10/U    01/B    11/B
HDN 014/019 909/006 906/007 909/007 910/018 902/022 901/018
    69/S    72/S    14/S    42/S    10/B    01/B    11/B
MLS 009/013 912/901 911/001 913/901 915/007 908/012 904/012
    4+/S    72/S    23/S    32/S    10/B    00/B    00/B
4BQ 023/028 910/006 905/010 907/006 909/013 902/019 000/017
    2+/S    71/B    12/S    33/S    20/B    00/B    00/B
BHK 017/018 914/903 912/002 912/000 916/005 911/010 906/010
    2+/S    92/S    23/S    33/S    20/B    00/B    00/E
SHR 023/032 906/016 002/018 904/013 907/019 000/025 002/023
    37/S    41/E    13/S    33/S    20/B    00/B    00/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Warning in effect until noon MST Monday FOR
      ZONES 28>31-40>42-63.
     Winter Weather Advisory in effect until noon MST Monday FOR
      ZONES 32>39-56>58-64>66.
     Winter Storm Warning in effect until 6 PM MST Monday FOR
      ZONES 67-68.
WY...Winter Weather Advisory in effect until noon MST Monday FOR
      ZONE 99.

&&

weather.gov/billings