563
FXUS65 KBYZ 101006
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
306 AM MST Fri Jan 10 2025

.KEY MESSAGES...

- Strong winds with gusts up to 65 mph are expected in the western
  foothills through Friday night.

- Active weather pattern this weekend. Significant snow and
  blowing snow is possible east/southeast of Billings through the
  weekend, heaviest Saturday afternoon through Sunday.

- Cold Canadian air builds into SE Montana Saturday night/Sunday.

- Warmer and drier conditions are expected mid next week.

&&

.DISCUSSION...

Today through Sunday night...

Messy/complicated short term forecast with a Pacific disturbance
crashing through the area tonight, then cold Canadian air making a
re-appearance in the easter half of the forecast area Saturday
night into Sunday. This pattern will bring a mix of precipitation
to the area tonight, and potentially significant snowfall to the
eastern half of the forecast area Saturday afternoon into Sunday.

Today looks mainly dry with ridging in control to start the day.
Westerly winds are already gusting over 50 mph along the western
foothills as of 2am. Approaching disturbance from the northwest
will accelerate winds over these areas further this morning into
this afternoon with gusts up to 65 mph expected from Livingston to
Nye/Big Timber and north to around Harlowton. Extended the going
High Wind Warning to include areas north of Big Timber into
Wheatland county with this forecast package, and pushed the
highlites out to midnight tonight based on latest guidance showing
a bit more widespread and longer lived period of strong winds.
Westerly winds will bring warmer temperatures to the area today,
ranging from the 40s in the west to the mid 30s over SE Montana.

Pacific front arrives this evening, with precipitation developing
along and behind it. Western mountains and foothills will be all
snow tonight, but for lower elevations central and west expect
initial precipitation to be mainly rain through the evening,
mixing with snow overnight. There is a hint in the models for
freezing rain, though this doesn`t fit the normal pattern for
freezing rain in our area. There could be some low lying areas
that hold onto cold temperatures this evening/overnight where
freezing rain could be a threat (20% chance), but overall there is
a bit of a warming trend with the Pacific front moving through
that should negate widespread impacts. That said, even rain
falling above freezing may produce some freezing rain type impacts
where the ground is frozen so will need to keep a close eye on
ground temperatures this afternoon as precipitation begins.

Rain should turn over to all snow Saturday morning and continue as
snow through the rest of this system. Heavier snowfall looks to
get going as colder Canadian air begins to push into the forecast
area from the northeast Saturday afternoon/evening. Latest
guidance suggests 3 to 6 inches of snow is possible over areas
east of Billings, with heavier accumulations in the higher hills
from Big Horn and Sheridan counties east across S. Rosebud and
W. Powder River. The northwest winds with this system will also
favor heavy snowfall for the northern Bighorn and the Pryor
mountains. Some portions of the Beartooth and Crazy mountains may
push over a foot of snow as well, but coverage there is not as
high as the Bighorn/Pryor areas due to these being closer to the
frontal forcing from the cold Canadian airmass hanging up over
central zones. Areas from Billings west should see significantly
less snowfall than areas further east as this system is currently
advertised. But it wouldn`t take a huge shift further west with
deeper cold air infiltration to generate higher snowfall further
west, so stay tuned.

Highs Saturday will be mainly in the lower 30s for highs, by
Sunday Highs will be in the lower teens for far eastern zones,
with 20s to lower 30s central and west. Overnight lows will drop
to the single digits above/below zero Saturday/Sunday night over
SE Montana, with teens and lower 20s elsewhere.

Winter Highlites...Continue with a Winter Storm Watch for the
eastern half of the forecast area from late tonight through Sunday
night. Given the duration of this event, snow amounts are only
getting close to warning criteria (8in/24hrs) for the higher hills
of Big Horn/Sheridan/S. Rosebud/W. Powder River counties at this
point. Timing for this heavier snowfall holds off until Saturday
afternoon so still some time to get a bit better certainty in the
models before pulling the trigger on a warning. Rest of the watch
area looks like an advisory will cover the snow/blowing snow
through the event. Wild card will be the potential wintry mix
should freezing rain become a bigger threat for tonight. Will let
the day shift take another look before finalizing the winter
highlites. Chambers

Monday through Friday...

This weekend`s storm will be on its way out during the day
Monday. A strong parent low centered in western ON could force
some small vort maxes through our area during the day Monday which
could prolong some light snowfall and breezy conditions in far
southeastern MT.

As we move into midweek, the entire CWA is expected to dry out and
slightly warm up. Highs in the mid to upper 30`s for the western
2/3 of the CWA (in the lower elevations) and in the upper 20`s in
the plains are forecast with a building ridge. Some breezy
conditions may return to the western foothills Tuesday into
Wednesday, however, it will not be as strong as this weekend`s
event.

The next chance for impactful weather will come towards the start
of next weekend where we could see below average temperatures and
the return of snow. However, this event is too far out to talk
specifics at this time. WMR

&&

.AVIATION...

VFR Conditions ar expectatio to prevail for most of the period.
Clouds will start to build in towards the end of the TAF period
with the next approaching weather system. The western foothills,
including KLVM and K6S0, will see westerly winds increase tonight.
Gusts of 40-55 kts possible by early Friday morning in these areas.
WMR

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sat     Sun     Mon     Tue     Wed     Thu
-------------------------------------------------------
BIL 037 031/037 026/032 021/033 020/036 023/038 022/037
    1/N 34/S    67/S    63/S    11/B    10/U    00/U
LVM 041 027/034 022/031 018/032 019/039 024/044 025/044
    0/N 56/S    55/S    32/S    00/B    00/U    00/U
HDN 040 030/037 022/031 020/033 018/037 018/039 015/036
    1/B 58/S    99/S    87/S    21/B    10/U    00/U
MLS 037 031/035 012/019 007/027 014/032 017/034 015/031
    0/B 67/S    93/S    34/S    21/B    10/U    00/U
4BQ 039 031/034 017/024 011/029 017/034 021/037 020/035
    0/B 59/S    +5/S    55/S    31/B    10/U    00/U
BHK 036 027/034 001/011 904/023 009/029 015/033 016/033
    0/B 67/S    91/E    12/S    21/Q    10/U    00/U
SHR 044 025/035 021/030 017/033 014/040 021/044 019/043
    0/B 78/S    89/S    77/S    21/B    10/U    00/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch in effect from this evening through late
      Sunday night FOR ZONES 30>33-36-37-57-58-138-169-171.
     Wind Advisory in effect until 4 AM MST Saturday FOR ZONES
      65-66.
     High Wind Warning in effect until midnight MST tonight FOR
      ZONES 141-172-228.
WY...Winter Storm Watch in effect from this evening through late
      Sunday night FOR ZONES 198-199.

&&

$$
weather.gov/billings