904
FXUS65 KBYZ 212122
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
222 PM MST Thu Nov 21 2024

.KEY MESSAGES...

- Low chance (10-15 percent) of freezing rain Friday and Saturday
  morning around Wheatland, Golden Valley, and Musselshell
  Counties.

- Next best chance of precipitation across the area in the form of
  rain then snow arrives for most of the area Saturday evening
  into Sunday. Snow amounts will be light on the plains.

- Sunday and Monday will be cooler.

&&

.DISCUSSION...

Rest of Today through Saturday...

Generally unsettled weather will continue into the weekend before
a more organized weekend system moves through Saturday evening
into Sunday (more on the weekend system in the long-term
discussion).

Before the weekend system, the main weather of concern is the
potential for freezing rain around Wheatland, Golden Valley, and
Musselshell Counties Friday morning and Saturday morning (low,
10-15 percent chance). During this time, the quantitative
precipitation forecast is low, so this should limit the potential
impact. Uncertainty also remains in the depth of the warm nose
aloft, but motorists should still use caution Friday and Saturday
morning around those counties as freezing rain could (low chance)
occur.

Outside of this, periods of isolated to scattered light snow look
to impact the Beartooth/Absaroka and Crazy mountains this evening
into Saturday. With this, accumulations will remain light with
totals around a trace to two inches.

Along with the precipitation, periods of windy conditions look to
continue over the Beartooth/Absaroka Mountains and foothills,
including the gap areas around Livingston to Nye, this evening
into Saturday. At this time, the strongest winds look to occur
this evening/night and Saturday ahead of a cold front. At this
time, there is around a 65 percent chance of 50 mph wind gusts
occuring Saturday.

High temperatures Friday and Saturday are forecast in the 30s to
lower 50s. Lows tonight and Friday night are forecast in the teens
to lower 30s. Arends

Saturday night through Thanksgiving Day...

Strong Pacific Jet noses into northern Wyoming Saturday night and
pulls a chunk of Canadian air southward overnight. This will bring
a period of light snow to the forecast area through Sunday
evening. This is a high precipitation chance/low precipitation
amount type of snowfall as the doesn`t get very deep and the low
level winds don`t stay in an upslope favored direction for too
long. Probabilities for an inch of snow in the lower elevations
tops out around 40 percent in a N/S band from Roundup to near
Billings and into W Big Horn county. Probs for 3+ inches even in
the north facing foothills are toping out around 20 percent. Highs
on Sunday are showing 30 to 80% probabilities of being 25 degrees
or colder along and northeast of a Harlowton to Billings to Alzada
line.

By Sunday night will see warm advection kick in and push the
colder air back out of the forecast area by Tuesday. Some light
flurries will be possible as the cold air retreats, but
significant snow is not expected during this period.

Wednesday looks like another transition day, potentially into a
more prolonged period of cold temperatures and persistent light
over-running snowfall through the holiday weekend. Probabilities
for highs under 25 degrees on Thanksgiving are 30% or better along
and northeast of a Harlowton to Billings to Alzada line. By Friday
most of the area is showing a 30 to 60% probability for cold highs
under 25 degrees. Travel going into the Holiday currently looks
OK, but the travel back is trending cold with persistent light
snow. Chambers

&&

.AVIATION...

Pacific moisture will continue to flow across the forecast area
through Friday, bringing mainly VFR ceilings to the area at times.
Current radar returns are not resulting in precipitation at the
lower elevations, but snow is falling in the mountains which will
bring occasional obscuration to mountains and passes through the
period. Can`t rule out a few light rain/snow showers tonight over
the western foothills and across northern zones from Harlowton to
Miles City as a weak cold front drops into the area. This weak
front may bring localized MVFR ceilings with it. Low level
inversion will persist through the next 24 hours, keeping winds
light across most of the area. Gap winds however will be gusty
along south to north oriented valleys through Friday, including
the KLVM vicinity. Currently gusts 30 to 40kts seem reasonable,
but will keep an eye on the favored gap wind time (09z-15z) for
potential stronger gusts. Chambers

&&

.PRELIMINARY POINT TEMP/POPS...

    Fri     Sat     Sun     Mon     Tue     Wed     Thu
-----------------------------------------------------------
BIL 028/038 024/044 021/029 010/032 018/040 021/038 016/029
    11/B    11/B    64/S    10/U    11/B    12/S    22/S
LVM 035/051 032/050 022/038 016/041 021/042 022/040 018/035
    22/R    27/O    74/S    11/B    21/B    33/S    33/S
HDN 023/042 022/041 018/028 007/032 013/039 016/038 013/028
    11/B    01/B    64/S    21/U    11/B    12/S    23/S
MLS 022/036 021/039 016/024 005/025 009/034 012/032 009/024
    00/B    11/B    43/S    11/U    10/B    01/B    11/B
4BQ 025/044 023/045 019/027 009/031 014/039 017/037 012/027
    00/U    00/B    12/S    10/U    00/B    01/B    11/B
BHK 018/038 017/036 013/026 002/025 006/034 012/033 007/025
    00/B    10/B    22/S    10/B    10/B    01/B    11/B
SHR 026/051 025/052 018/032 010/039 016/044 017/040 014/033
    00/B    00/B    44/S    20/U    00/B    13/S    33/S

&&

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

&&

$$
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