572
FXUS65 KBYZ 100831
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
231 AM MDT Fri Oct 10 2025

.KEY MESSAGES...

- Warm and mostly dry through midday Saturday. An increasing
  chance of showers by late Saturday.

- Weather system arrives Saturday evening bringing precipitation,
  cooler temperatures, and blustery winds to the area through
  Sunday.

- Several inches of snowfall expected over the Absaroka-Bearooth
  and Crazy Mountains, and accumulations also possible over the
  Bighorn Mountains.

- Frost/freeze for most areas Sunday night and Monday night.

- Unsettled weather with seasonably cool temps expected next
  week.

&&

.DISCUSSION...

Today through Sunday...

Upper ridge axis across eastern MT today will slowly slide east
to the high plains. This allows for backing mid level flow and
some moisture developing into south central MT as early as
sunrise. This could produce a few showers across across Park
county and nearby areas, but measurable rainfall will be spotty at
best. Additional isolated showers may develop across southern MT
and northern Wy this afternoon and into the evening, but again
little more than light local showers or sprinkles. In the
meantime, look for brisk (Gusts 25-35 mph) southeast winds to
develop today across our eastern zones in response to low pressure
developing across the northern front range. We will see
temperatures a few degrees warmer than yesterday, with highs in
the 70s. By the evening into the overnight, a few gusts to 40 mph
are expected over the higher hills around Baker and Ekalaka.

Saturday looks to be the warmest day going forward for areas east
of the mountains with high temperatures in the 70s to lower 80s
thanks to downslope flow and compressional warming ahead of the
approaching upper trough. As the upper trough moves into the
Northern Rockies we will see an increasing chance of scattered
showers, and possibly a few thunderstorms, develop over the
western third of our CWA (think Billings westward) thanks to
increasing instability, divergent flow and some jet dynamics. An
associated cold front pushes across the area Saturday night, and
if the model proggs are correct, it looks like a rather robust
frontal passage with decent pressure rises and cold air advection.
So look for a blustery overnight period into Sunday with NW winds
(gusts 25-40 mph) and a post frontal band of precipitation
pushing across the region. Gusts to near 50 mph are even possible
Sunday over the higher hills from Baker to Ekalaka. Temps may be
20 to near 30 degrees cooler for most locations on Sunday. Models
still differ on the exact track of the upper trough, but consensus
suggest most of the energy lifts into NE MT Sunday afternoon. By
Sunday evening the chance of precipitation diminishes, with just
some lingering rain/snow showers over the foothills west of
Billings (Big Timber through Harlowton).

Precipitation...At this time, the heaviest precipitation is
expected west of Rosebud County where there is a 60-80% chance of
at least 0.50 inches of liquid precipitation possible. That chance
decreases to around 10% by the time you reach the SE corner of MT.
As far as seeing an inch or more of precipitation through the
event goes, chances range from 35 to 65 percent around and west
of Billings, greatest over the mountains and foothills, and drop
to near zero percent in our far east.

Snowfall...While precipitation over the lower elevations will
be mainly rain, snow levels look to drop to around 5,500 to 6,000
feet by mid- day Sunday. At this time, the chance of seeing 6 or
more inches of snow is generally 50-75% above 8,500 feet in the
Absaroka- Beartooth and Crazy Mountains. The chance of seeing 12
or more inches of snow is 20 to 50 percent...highest over the
Crazies which is favored if the trough tracks as expected. We have
issued a Winter Storm Watch for the Crazies from 900 pm Saturday
to 900 pm Sunday. Over the Bighorns, less snow is expected, with
the chance of seeing 6 or more inches of snow just 25%. Overall at
this time we expect 6-10 inches in the Beartooth/Absarokas, 8-15
inches in the Crazies and about 3-5 inches in the Big
Horns...mainly above 8500 ft. This pattern is not the most
favorable for the Red Lodge Foothills as winds look to downslope
initially, though a little snow or mixed precip is possible there
on Sunday.

By late Sunday, temperatures across the area are expected to drop
into the 30s near the foothills and nearby lower elevations (Big
Timber to Judith Gap). Accumulations, should they occur, are
expected to remain pretty light in these areas. Looking farther
east, areas around and north of Baker have around a 20 percent
chance of seeing snow, with only light accumulations possible.
Across the rest of the area, the chance remains low (generally
less than 15 percent). Will have to see how things trend as
uncertainty still remains in just how cold the system is overall
and how much any measurable precip lingers.

As mentioned above, overnight lows Sunday night and Monday night
are also likely to drop near or below freezing (50-100%).

Monday through Thursday...

Ensembles in fair agreement we will see some modest ridging over
our area to start the work week with generally dry conditions.
However, the air mass moderates very little through midweek with
temps generally remaining at or a little below seasonal averages
in the upper 50s to mid 60s by Wed. Progs then indicate another
upper low dropping down the west coast and eventually spinning
some moisture into our region around midweek, with some cooling
as heights fall over our region as a split flow trough axis slides
across our area. So generally remaining on the coolish side with
chance of showers returning at midweek. BT

.AVIATION...

VFR conditions will prevail through the period. Breezy southeast
winds gusting 20-30 kts are forecast in eastern MT (KMLS, KBHK,
K97M), after sunrise this morning and lasting through the
afternoon. PM


&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sat     Sun     Mon     Tue     Wed     Thu
-------------------------------------------------------
BIL 072 051/078 042/050 032/047 030/049 034/060 038/054
    0/B 04/R    +7/R    31/B    11/B    22/W    44/W
LVM 076 048/071 033/050 025/044 025/052 031/059 031/055
    2/R 17/T    97/R    42/O    12/W    33/W    44/W
HDN 073 046/079 040/050 028/052 027/051 031/061 034/055
    1/B 13/R    98/R    21/B    11/B    23/W    54/W
MLS 077 051/080 042/052 027/049 031/056 034/061 037/056
    0/U 00/U    78/R    10/U    11/B    22/W    43/W
4BQ 076 053/079 044/053 029/051 035/057 036/064 039/057
    0/U 00/B    47/R    10/U    10/U    22/W    43/W
BHK 072 049/079 043/054 024/050 030/058 034/062 035/057
    0/N 10/B    36/R    10/U    10/B    22/W    43/W
SHR 076 046/079 037/052 027/053 029/055 031/064 033/057
    1/B 01/B    78/R    20/B    11/U    23/W    54/W

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch in effect from Saturday evening through
      Sunday evening FOR ZONE 68.
WY...None.

&&

$$
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