396
FXUS65 KBYZ 222045
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
145 PM MST Wed Jan 22 2025

.KEY MESSAGES...
- Light snow, gusty winds, and blowing snow across southeast
  Montana and north central WY through tonight.

- Period of gusty to strong winds along the western foothills
  Thursday into early Friday.

- Another period of accumulating snow is possible Friday into
  Saturday, heaviest along and south of I-90 in upslope favored
  locations.



&&

.DISCUSSION...
Tonight through Friday Night...

Continued Snow...

Another round of snow showers move through the region tonight
with 700mb warm air advection creating a deeper DGZ. Winds will
continue to gust into the 30s mph leading to continued visibility
reductions due to snow and blowing snow this evening into tonight
for areas in the Winter Weather Advisory. Winds will begin to
decrease from north to south overnight leading to improved
conditions.

Foothills Winds...

An upper level ridge will move into the region tomorrow leading to
pressure falls over the Montana plains. This will strengthen the
pressure gradient over the foothills. Deterministic and ensemble
systems show the Idaho Falls to Lewistown gradient getting into
the teens by early Thursday and remaining strong through early
Friday. Westerly 700mb winds in the 40kt range will contribute to
give Livingston a 90% chance for a gust over 50mph. Big Timber and
Harlowton will be limited by a persistent inversion giving them a
35-50% chance for winds over 50mph.

Friday Snow...

A 500mb trough moves in from the north bringing a frontogenesis
snow band early Friday. The Beartooth and Bighorn foothills with
northerly upslope have the best chance for accumulating snowfall.
Winds appear to be more northwesterly than previous model runs,
leading to ensembles continuing a trend of lower snow totals
across the region. Currently, most of the Beartooth foothills have
a 50-75% chance for greater than 2 inches of snowfall.

Low temperatures tonight will be cool ranging from single digits
to low teens. High temperatures Thursday and Friday will be
similar ranging from the mid 20s to mid 30s.

Torgerson

Saturday through Wednesday...

A relatively quiet extended forecast compared to the last few
weeks. Lingering snow is expected over the southern mountains and
foothills Saturday morning, diminishing by the afternoon. Highs
Saturday will stay on the cool side, mainly 20s with some teens SE
Montana. Northerly flow aloft looks pretty dry and outside of
slowing down the warmup a bit, it doesn`t look like any impactful
weather to speak of through the weekend. By Monday will see the
semi-permanent (at least this winter) West Coast ridge flop over
to the east and cover the Northern Rockies. This will bring back
some gustier west winds for the foothills, and help to boost
temperatures to normal/above normal levels going into the middle
of the week. Right now the strength of the ridge and the surface
pressure gradient don`t look too impressive, but this pattern
would favor advisory type winds in the gap wind favored locations
so stay tuned. Otherwise, enjoy a good deal of sun and warming
temperatures through the weekend into early next week. Chambers &&

.AVIATION...

Unstable northwesterly flow over the area through tonight will
keep areas of light snow, and locally heavier snow showers, going
through the night, mainly east of Billings (KSHR/KMLS/K4BQ). In
addition to the snowfall, NW winds gusting 30-40kts will create
blowing and drifting snow impacts. Visibility may drop under a
mile at times with the heavier snow showers pushing down the
stronger wind gusts and increasing the blowing snow. In the
foothills and higher hills from Sheridan/S. Big Horn county east
into Powder River county LIFR or lower conditions are expected
(and have been occuring) at times through late tonight (~10z).

East of Billings visibility may drop to around 3sm at times in
and near orographic snow bands moving southeast off the higher
terrain to the northwest. This banding could impact KBIL at times
through 07z. KLVM could see some lighter snow showers through late
evening. Expect winds in the KLVM vicinity (along with other
western foothills locations K3HT/) turn from a west/northwest
drainage wind to a southwest gap wind overnight. Winds will
increase to around 40kts overnight with this gap effect, possibly
becoming stronger going through Thursday morning. Chambers
&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 014/032 023/032 012/024 006/028 019/038 024/042 021/039
    20/U    05/J    20/B    00/U    00/N    00/U    00/U
LVM 010/034 022/028 006/021 003/029 017/040 024/044 023/042
    00/N    08/J    20/B    00/U    00/U    00/N    00/N
HDN 009/034 022/033 011/024 000/028 012/041 017/041 016/037
    60/U    17/J    21/B    11/U    00/U    00/U    01/B
MLS 010/029 022/029 011/019 003/025 014/036 019/036 018/033
    20/B    22/J    00/B    00/U    00/B    00/U    00/B
4BQ 015/029 021/029 013/020 001/025 014/037 019/039 018/035
    40/B    13/J    10/B    00/U    00/U    00/U    00/B
BHK 004/025 014/027 006/016 901/020 009/032 014/034 014/032
    10/B    23/J    10/N    00/N    00/N    00/N    00/B
SHR 010/033 015/028 006/020 903/028 008/042 018/044 018/040
    60/U    05/J    41/B    00/U    00/U    00/U    00/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 11 PM MST this
      evening FOR ZONES 30>32-63-171.
     Winter Weather Advisory in effect until 5 AM MST Thursday FOR
      ZONES 33-36-37-57-58-169.
     Wind Advisory in effect from 5 AM Thursday to 5 AM MST Friday
      FOR ZONES 65-66.
     Winter Storm Warning in effect until 5 AM MST Thursday FOR
      ZONE 138.
WY...Winter Weather Advisory in effect until 11 PM MST this
      evening FOR ZONE 198.
     Winter Storm Warning in effect until 5 AM MST Thursday FOR
      ZONE 199.

&&

$$
weather.gov/billings