519
FXUS65 KBYZ 081113
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
413 AM MST Wed Jan 8 2025

.KEY MESSAGES...

- West winds gusting 35-55 mph (highest close to foothills)
  producing areas of blowing & drifting snow from Billings
  westward through this morning.

- Rain/snow showers with gusty post-frontal NW winds across lower
  elevations this afternoon into Thursday; some snow accumulation
  over the mountains, and higher hills east and south of
  Billings.

- Seasonable temperatures through the week; periods of snow
  showers expected over the weekend.

&&

.DISCUSSION...

Today through Thursday night...

Currently, analysis shows ridging with a weak wave bringing light
snow showers through Wheatland Co. area ahead of the main wave
set to pass through the day today. Ahead of this system we are
seeing a good pressure gradient over the western foothills as well
as increasing 700 mb winds creating strong winds and reduced
visibility for areas of I-90 west of Billings, especially through
the Big Timber area. Areas west of Billings, (gap wind areas as
well as areas up through Belfry, Laurel and Molt) will continue to
see gusts 35-55 mph with higher gusts for the Big Timber area
near 60 mph through the morning, slightly decreasing into the
afternoon.

Frontal passage is expected to enter the west midday,
tracking east through the afternoon and evening. This will bring
an increased chance of precipitation (rain/snow mix) with areas
east of Billings seeing the best chance for accumulating snowfall
into this evening. Snowfall in combination with the breezy
frontal and post- frontal winds will create areas of blowing snow
through portions of southeast MT with gusts up to 40 mph (40-60%
chance). Accumulations will be up to 2-3 inches with 3-5 inches
possible over areas of higher terrain. With this, a Winter Weather
Advisory has been issued for these areas as well as the Pryors
and northern Bighorn Mountains for accumulations of 5-9 inches and
the increased risk of blowing snow. Advisory for Beartooth/Red
Lodge foothills as well as portions of south-central MT continue
through the morning with the main risk continuing to be blowing
snow causing reduced visibilities.

Into Thursday, snow will end through the early morning in SE MT
with snow over the mountains gradually dissipating through the
day. Conditions will remain breezy across SE MT through Thursday,
but winds will gradually decrease through the day. Conditions
should generally be calm, dry and seasonable Thursday (excluding
the mountains). Thursday`s highs will be only slightly cooler than
today`s highs(30s) in the upper 20s to 30s. Late Thursday evening
the gap wind pattern for Livingston and Big Timber sets up
through the night likely bringing gusts into the 30s and 40s (mph)
with a 40% chance of a gust to 50 mph. TS


Friday through Tuesday...

An active northerly flow will persist into early next week. This
will yield alternating periods of dry windy conditions, and post-
frontal snow with breezy NW-N winds. Overall, temperatures will
fluctuate around season norms.

Friday looks dry with strong winds possible in the western
foothills again (Klondike Chinook pattern). Another trough in the
northwest flow moves into the area Friday night, ending any high
wind threat, but spreading rain/snow showers over the region into
Saturday. Then plenty of mid level moisture and shortwave energy
result in a continued chance of snow showers through Sunday.

So at this time, Saturday into Sunday have the best chance for
accumulating snow. 48 hr snow totals over the weekend hit the
areas east and south of a Billings to Miles City line with 2-4
inches and up to 4-8 inches over the higher hills. The chance of
at least 3 inches in this area range from 40-80% (highest on the
hills). Billings westward looks pretty downsloped and the chance
of an inch accumulation only 25% for the whole weekend time frame.
Over north facing slopes in the mountains, the Absaroka/Beartooths
have a 60% chance of at least 6 inches of snow and the Bighorns
have an 80% chance of the same.

Ensembles still suggest a quieter dry period (though breezy)
after Monday, with drier and breezy conditions by Tuesday as
ridging over the west prevails. This may last for at least the
middle part of next week. BT

&&

.AVIATION...

Look for surface visibility to be frequently reduced from 1-4
miles in the foothills due to blowing/drifting snow. This includes
KLVM, K6SO and K1KM as west winds gust 35 to 45 kts. SOme
reduction in visibility is also possible at KBIL with gusts 24 to
35 kts possible. A cold front will move across the region after
19Z Wed resulting in a decreasing wind and blowing snow threat.
However, post frontal rain/snow showers are then possible late and
into the evening with increasing widespread low clouds dropping
conditions to MVFR/IFR. BT

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Thu     Fri     Sat     Sun     Mon     Tue
-------------------------------------------------------
BIL 037 021/035 015/035 029/036 024/034 020/030 016/031
    4/J 60/U    01/B    45/S    35/S    43/S    11/B
LVM 038 023/034 019/040 026/034 021/032 018/031 017/036
    3/J 60/B    01/N    76/S    23/S    21/B    11/B
HDN 038 020/035 009/037 028/037 024/033 019/030 013/033
    6/W 81/U    02/S    78/S    68/S    74/S    11/B
MLS 036 022/030 009/033 026/033 021/028 010/020 005/024
    4/W 70/B    01/B    78/S    87/S    63/S    11/B
4BQ 038 024/030 013/035 028/035 024/029 015/023 010/029
    2/W 91/B    00/B    79/S    87/S    63/S    11/B
BHK 035 020/028 009/031 022/032 015/026 001/016 003/024
    2/J 80/Q    00/B    68/S    86/S    42/S    10/B
SHR 043 020/033 010/041 024/035 019/032 016/030 011/036
    3/W 91/B    00/B    88/S    67/S    64/S    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect from 2 PM this afternoon to
      9 AM MST Thursday FOR ZONES 33-36-37-58-138.
     Winter Weather Advisory in effect until noon MST today FOR
      ZONES 34-42-56-63-65-66-139-141-170-172-228-235.
     Winter Weather Advisory in effect from 11 AM this morning to
      11 AM MST Thursday FOR ZONE 171.
WY...Winter Weather Advisory in effect from 11 AM this morning to
      11 AM MST Thursday FOR ZONE 198.

&&

$$
weather.gov/billings