850
FXUS65 KBYZ 012219
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
319 PM MST Mon Dec 1 2025

.KEY MESSAGES...

- Gusty crosswinds over the foothills west of Billings through Tuesday
  morning, strongest around Livingston to Nye this evening.
  Crosswinds may impact portions of I-90 and US-191.

- Localized blowing snow possible through tonight with increased
  winds, but confidence remains low.

- Weather system brings precipitation (rain/snow) back to the area
  tonight through early Wednesday. Light snow accumulations
  expected over the higher hills of southeast MT with several
  inches of snow down into the southern mountains and foothills.

- Unsettled conditions continue Thursday into the weekend.

&&

.DISCUSSION...

Through Sunday...

Heights building in from the west and a klondike chinook have
allowed temperatures to warm into the 20s and 30s today, with
breezy winds for areas west of Billings. Winds have gusted in the
40 to 55 mph range at times, and the gusty winds are expected to
continue into the evening and night, strongest over the western
foothills. Winds will begin to decrease into Tuesday morning as
the next weather system drops into the region. Where wind gusts
are greatest, localized blowing snow remains a low threat.

An initial shortwave will track south and east through the area
late tonight into Tuesday, bringing some light snow to the western
mountains, but also a band of precipitation for areas mainly north
and east of Billings. South-central Montana (including Billings)
will be affected by downsloping, with less precipitation
potential. By later Tuesday into Tuesday night, a cold front from
the main splitting trough looks to turn winds more out of the
north than northwest, allowing the second wave of precipitation to
push south into the mountains and foothills of southern Montana
and northern Wyoming where upslope enhancement looks to be in
place. Unstable northerly flow (lapse rates greater than 7 degrees
C/km) and frontogenesis pushing into the southern mountains will
allow for a period of decent snowfall Tuesday evening. While
precipitation may linger into Wednesday morning, downslope winds
look to regain control by mid- day, ending any remain
precipitation over the area.

With temperatures expected to climb into the 30s on Tuesday,
precipitation may become a rain/snow mix over the lower
elevations/valleys, while the higher hills remain a wet snow. As
the cold air works in from the north by Tuesday evening, expect
all precipitation to change over to snow. Snowfall amounts are
expected to range from a dusting, up to a few inches over the
highest hills in southeast MT, to several inches of snow into the
southern foothills and mountains. Greatest totals will be found
over the northerly upslope areas of the Beartooth/Absaroka and
Pryor/Bighorn mountains where 5 to 10 inches are possible. Breezy
northerly winds of 15 to 30 mph will produce some blowing snow as
well, which could further reduce visibility. Any wet or slushy
surfaces will likely freeze Tuesday evening as the colder air
works in (lows Tuesday night in the single digits to teens). Have
gone ahead and issued winter weather advisories for portions of
the southern foothills, into southeast MT, as well as the northern
Bighorns/Pryors starting tomorrow, and continuing into Wednesday
morning.

Dry but cooler conditions will prevail for Wednesday, with highs
into the teens to 30s, lowest over the east. The rest of the
forecast looks to remain unsettled with periods of precipitation
and wind. Temperatures will oscillate back and forth from above,
to near, to below normal at times (20s to 40s). While uncertainty
remains in timing and placement of precipitation, there is
moderate to high chances (40-70%) Thursday through Saturday. Stay
up to date with the forecast if you have outdoor or travel plans
later this week. STP

.AVIATION...

21z Discussion...

Expect winds in the foothills (KLVM/K6S0) to continue to be
strong out of the west through this afternoon and evening with
gusts up to 45kts. After sunset (00Z) the winds at KLVM are
forecast to switch to out of the SW. SHSN move into the area after
02z from west to east. All sites will be impacted at some point
over the following 18 hours. BLSN may be a concern today in the
foothills and again across the region as the new snow begins to
fall. Mountains will obscured after 00z. WMR

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 026/037 017/030 019/036 026/038 022/034 018/039 026/041
    26/O    61/B    00/B    23/S    54/S    20/B    10/B
LVM 028/038 018/036 021/039 026/042 027/040 025/042 027/044
    46/S    51/B    01/B    45/O    65/O    21/B    21/N
HDN 021/037 014/029 012/038 023/039 018/034 013/039 023/041
    47/O    81/B    01/B    44/O    66/O    41/B    11/B
MLS 020/036 009/019 011/034 024/034 013/026 008/034 023/037
    37/O    41/B    00/B    42/S    63/S    30/B    10/B
4BQ 021/036 013/022 015/036 023/037 019/033 016/036 026/039
    28/O    71/E    00/B    32/S    43/S    30/B    10/B
BHK 015/035 000/017 005/033 019/032 009/025 004/031 018/036
    24/S    30/B    00/B    32/S    53/S    30/B    10/B
SHR 022/038 015/030 011/039 019/040 019/036 016/042 021/043
    27/O    82/S    00/B    33/O    55/O    40/B    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect from 5 AM Tuesday to 5 AM
      MST Wednesday FOR ZONES 36-37-57-58-138.
     Winter Weather Advisory in effect from 5 PM Tuesday to 5 AM
      MST Wednesday FOR ZONES 56-66-169.
     Winter Weather Advisory in effect from 11 AM Tuesday to 5 AM
      MST Wednesday FOR ZONE 171.
WY...Winter Weather Advisory in effect from 5 PM Tuesday to 5 AM
      MST Wednesday FOR ZONE 199.

&&

$$
weather.gov/billings