374
FXUS65 KBYZ 220904
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
204 AM MST Sat Nov 22 2025

.KEY MESSAGES...

- Dry & warm (10-15F above normal) through the weekend.

- Breezy winds for the western foothills this weekend (gusts
  25-45mph); a period of stronger winds expected Sunday night and
  Monday.

- Turning windy and colder regionwide Monday and Monday night,
  with scattered rain and snow showers and gusty winds (25-40mph).

- Periods of light rain/snow possible Tuesday through Friday,
  with temps in the 30s to mid 40s (warmest near foothills).

- Confidence increasing for the first Winter Storm of the season
  as surge of Arctic air and accumulating snow arrive Friday night
  and stick around through next weekend; be prepared for wintry
  impacts to holiday travel, and monitor the forecast!

&&

.DISCUSSION...

Today through Saturday...

There are several periods of impactful weather, some mainly due to
the holiday travel period, in the next week to 10 days. Here is a
quick look in chronological order:

- Warm and Dry conditions today and Sunday, if you have outdoor
  activities to get done this is the time.
- Breezy conditions (gusts 20 to 40 mph) in the western foothills
  over the next several days, no advisories or warnings
  anticipated.
- Strong cold front Monday morning bringing 20 to 40 percent
  chances for snow Monday afternoon and night.
- A 10 to 20 percent chance for near Blizzard conditions
  developing over Fallon and Carter counties (maybe eastern
  Custer/Powder River) east into the Dakotas Monday night through
  Tuesday.
- Stalled front over the area could bring light accumulating snow
  Thursday and Friday (20 to 30 percent chance) or it could be a
  light mix of rain/snow.
- Arctic front and several days of accumulating snow looking more
  likely for next weekend when folks are traveling home.

Synopsis: Stronger zonal flow over the area this morning as energy
and cooler air flows from western Canada into a deepening trof in
the vicinity of the Great Lakes. This extra momentum along with
weak impulses in the flow are keeping surface winds stirred up
resulting in warmer overnight temperatures in the 40s central and
west and upper 30s east, about 10 to 15 degrees above yesterdays
low temperatures. This zonal flow regime will remain in place over
the area today and tomorrow for above normal temperatures (50s)
and dry conditions. Winds will continue to be breezy to
occasionally gusty over the western foothills as the cross
mountain flow favors downslope mixed winds each afternoon and
moderate gap winds in the overnight period. Guidance keeps wind
gusts below 50 mph (20% chance) through Sunday. Gusts in the 20s
are expected today over the rest of the forecast area, lighter on
Sunday.

Sunday night the influence of an approaching cold front begin as
Gap winds in the Livingston area kick in. Latest guidance
suggesting a 30 percent chance for getting up to 60 mph wind gusts
by midnight Sunday night, continuing into Monday morning. Front
moves into the area Monday morning and crosses through the eastern
portion of the forecast area Monday afternoon. Winds will increase
behind the front along with rain/snow chances. Most areas are
looking at 30 to 50 percent chances for light precipitation
(0.05in or less) with this system through Monday night, with
higher chances in the mountains. Temperatures Monday will probably
be in the 40s in the morning, falling into the 30s in the
afternoon as the colder air works into the area.

Near Blizzard conditions are being advertised for Monday night
into Tuesday, from SE Montana into the Dakotas, by some members
of the Canadian and most GFS members,but not by the ECMWF
members, this morning. The Blizzard leaning members are dragging
energy from the southern plains northward and combining it with
the Canadian trof moving in from the northwest and spinning up a
strong stacked closed low in the Dakotas, while most of the
Canadian and the ECMWF solutions don`t bring this southern energy
north and the Canadian trof simply slides through without the
strong baroclinicity developing over the northern plains. NBM
probabilities for enough snow and strong winds to support near
Blizzard conditions are in the 10 to 20 percent range for Fallon
and Carter counties, with around 5 percent further west into
Custer and Powder River. This is trending lower than yesterday due
to many ensemble members simply developing the low a bit too far
to the east/northeast to have the stronger impacts over eastern
Montana. At this time the going forecast is showing wind gusts in
the 30 to 45 mph range and periods of light snow (30-40% chance an
inch or less) and some mention of blowing snow. We will continue
to monitor this situation as it could present numerous impacts to
holiday travel and other interests from eastern Montana across the
northern plains, but at this time the probabilities remain low
for an impactful winter storm.

Northwest flow behind the exiting trof will bring cool
temperatures but dry conditions outside of the western mountains.
Pacific moisture flowing over western Montana will keep low
chances for light snow going along and west of the divide. Any
travel impacts should be confined to the higher passes west of
Billings and across western Montana.

Thursday and Friday are going to be tricky to forecast correctly.
The jet stream will be cutting across Montana from NW-SE during
this period, sloshing the colder Canadian air, that built in with
Mondays front, north and south across the forecast area. In this
regime there will be an area/band of persistent precipitation that
will follow these oscillations of cold air. Disturbances following
the jet will bring precipitation enhancement at times as well. The
trick is going to be not only where the precipitation sets up but
what the precipitation type will be. In the colder air mainly
snow, while in the warmer area rain will be the main type. In
between there is a scenario where light freezing rain mixes in.
High temperatures on Thanksgiving are currently advertised in the
mid 40s west and the mid 30s east, falling about 5 degrees across
the area Friday. Given the above considerations though this could
realistically be too warm or cold depending on how deep the cold
air gets and where the dividing line sets up during this period.
Either way at this point impacts look fairly minor with unsettled
conditions on Thanksgiving and on Friday.

Bigger impacts are starting to develop in the models from Friday
night through the end of the Holiday weekend. An Arctic over-
running event is being advertised strongly in the models for this
period. The deterministic ECMWF is pushing a 1050mb surface high
south into our area resulting in sub-zero temperatures arriving by
Sunday night, after a couple of days of light snow Sat/Sun put
down a decent snowpack across the area. This scenario has been
being tracked by NWS long range forecasters at WPC for a few weeks
now as changes in the Arctic Oscillation, Polar Vortex, and
Stratospheric temperatures have been pointing to a dislodging of
cold Arctic air southward at some point by the end of November
into early December, and now the global models are catching on to
it. So, the potential for significant snow and the arrival of
bitter cold temperatures are shaping up for the drive home from
Thanksgiving activities. Stay tuned to the forecast as this could
be the first major winter storm system of the season. Chambers

.AVIATION...

Gusty southwest winds at KLVM will continue through the day in the
25-30kt range with winds picking up to 40kts this evening. VFR
conditions will prevail.

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sun     Mon     Tue     Wed     Thu     Fri
-------------------------------------------------------
BIL 054 034/056 035/046 025/037 021/038 026/044 029/041
    0/B 00/U    03/O    20/B    01/B    34/O    33/O
LVM 054 032/055 031/041 019/035 018/041 028/047 030/044
    0/B 00/N    15/O    20/B    12/S    43/O    24/O
HDN 054 028/055 030/048 023/037 017/038 022/044 025/042
    0/B 00/U    04/O    21/B    01/B    34/O    33/O
MLS 051 030/055 031/048 022/032 016/033 018/036 022/034
    0/B 00/U    03/O    31/N    00/B    23/S    22/S
4BQ 052 030/055 031/048 022/032 018/034 019/039 025/040
    0/B 00/U    02/O    31/N    00/B    12/O    21/E
BHK 049 029/055 029/048 018/031 011/033 013/034 018/034
    0/B 00/U    02/O    42/S    00/B    12/S    21/E
SHR 054 028/057 028/048 017/034 013/037 018/045 023/044
    0/B 00/U    04/O    41/N    00/B    22/O    22/O

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

$$
weather.gov/billings