555
FXUS65 KBYZ 080156
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
656 PM MST Fri Feb 7 2025

.KEY MESSAGES...

- Snow will come to an end from west to east this evening and
  night. Expect travel impacts to continue into tonight.

- Increasing confidence and concern for extreme cold conditions,
  first half of next week. Periods of light snow will accompany
  the cold air.

- Another period of accumulating snow and cold expected late next
  week.

&&

.UPDATE...

Snow has been gradually decreasing from west to east this evening.
Have gone ahead and canceled the Winter Storm Warning for the
western mountains and Winter Weather Advisory for western and
central zones. The rest of the forecast remains on track. STP

&&

.DISCUSSION...

Rest of Today through Sunday Afternoon...

Snow has created difficult travel conditions across much of the
area today. Expect these difficult travel conditions to continue
through the evening commute. For the latest road conditions, call
511, or visit 511mt.net (MT) or map.wyoroad.info (WY).

Snow continues this afternoon across much of the area. While the
snow may decrease a bit temporarily this afternoon, a final push
is expected to move through the area around the evening commute.
By this evening into tonight, the snow is expected to come to an
end from west to east. During this time, another 1 to 3 inches of
snow is forecast across much of south- central and south-eastern
Montana. One thing to note, the probability of seeing snow rates
over an inch an hour decrease this afternoon and evening as cooler
air moves in aloft, limiting the depth of the dendritic growth
layer. Winds are also expected to decrease through the late
afternoon and evening today, ending the blowing and drifting snow
threat. Even after the snow ends, snow packed and drifted roads
will continue to create difficult driving conditions, so continue
to use caution traveling tonight after the snow ends.

As far as products go, the Winter Storm Warnings for the lower
elevations have been downgraded to Winter Weather Advisories as
the heaviest snow is now over. The rest of the Winter Weather
Advisories remain. The end times on all the winter weather
products have been pushed up.

Temperatures tonight will be cold with lows in the single digits
to teens below zero. With this, wind chills could hover in the
teens to lower 20s below zero.

Saturday will be a mostly dry day outside of isolated to
scattered light snow showers in the mountains. Look for
temperatures to warm into the single digits to mid 20s above zero.
Similar temperatures will exist Sunday ahead of another cool down
anticipated for early next week (see long term discussion).
Cyclonic flow Sunday could also produce isolated to scattered
light snow over south- central Montana. Arends

Monday through Friday...

Cold and unsettled pattern through the extended and likely through
next weekend. Upper low drops through the Canadian Plains Sunday
into Sunday night and drops a punch of Arctic air into the area.
The focus of the coldest air with this system looks to be oriented
over far eastern MT into the Dakotas as opposed to hugging the
divide this time, so the latency of the cold air will be shorter.
However it is a cold 1050mb high pressure system with highs Monday
and Tuesday staying in the single digits above and below zero.
Tuesday morning looks like the coldest timeframe with teens/20s
below zero. Wind speeds wont be strong but will be enough for Wind
Chill values of 30 to 45 below zero, coldest along the eastern
state line.

Westerly flow aloft develops late Tuesday into Wednesday which
should push temperatures into the teens, but it doesn`t look to
get much warmer than that through the end of the week, so well
below normal.

Another round of snow sets up for Thursday into the weekend with
more energy rotating in from Canada while a Pacific system throws
moisture over the top of the cold air. This system could be a
prolific snow producer if the ingredients come together just right
so stay tuned. Chambers

&&

.AVIATION...

00z Discussion...

Snow is gradually ending from west to east and this trend is
expected to continue overnight. Most sites are currently sitting
at IFR/LIFR but conditions should improve to MVFR across the
region as the snow tapers off. Gusty winds are not expect to be
an issue tonight for any locations, however, KSHR is seeing some
gusts right now and therefore opted to include BLSN for a short
time in the TAF there.

There is some indication that fog could develop overnight with the
clearing out of the skies but it seems more likely that most
areas should be spared any truly dense fog. I have decided to
leave in / include VCFG and BR at all TAF sites as there still is
a decent chance for some localized development. Reevaluation of
the forecast may be necessary as the snow moves out and skies
clear out and thus amendments will be sent out as needed.

Mountains will be obscured through at least 16z. VFR conditions
will develop after sunrise Saturday. WMR

&&

.PRELIMINARY POINT TEMP/POPS...

    Sat     Sun     Mon     Tue     Wed     Thu     Fri
-----------------------------------------------------------
BIL 906/023 007/021 000/006 914/009 908/015 904/013 001/013
    50/U    12/S    66/S    10/B    00/B    12/S    44/S
LVM 000/025 010/026 001/008 911/013 905/019 003/025 008/023
    10/U    11/B    44/S    10/B    00/B    13/S    54/S
HDN 910/020 002/021 902/007 917/009 913/016 909/016 902/014
    70/U    03/S    67/S    10/B    01/B    12/S    45/S
MLS 906/012 903/014 906/002 921/003 913/008 912/008 903/008
    80/U    00/B    32/S    00/U    00/B    00/B    33/S
4BQ 904/020 003/019 000/005 915/008 909/014 907/015 001/013
    60/U    00/B    23/S    10/B    00/B    00/B    33/S
BHK 905/011 904/012 910/902 924/001 913/006 913/008 907/007
    80/B    00/U    22/S    00/U    00/B    00/B    33/S
SHR 908/024 003/024 902/010 916/009 912/017 907/021 001/020
    30/U    11/B    25/S    11/B    00/B    01/B    23/S

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 9 PM MST this evening
      FOR ZONE 30.
     Winter Weather Advisory in effect until 11 PM MST this
      evening FOR ZONES 31-57-58-138-169.
     Winter Weather Advisory in effect until 2 AM MST Saturday FOR
      ZONES 32-33-36-37.
WY...None.

&&

$$
weather.gov/billings