175
FXUS65 KBYZ 300009
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
609 PM MDT Mon Sep 29 2025

.KEY MESSAGES...

- Temperatures 10-20 degrees above average through Thursday.

- 20-40% precipitation chances Tuesday across the lower
  elevations. Less than 0.10 inches expected.

- Pattern change expected late Thursday into the weekend with a
  change to cooler and wetter conditions.

- Snow for the mountains and possibly the foothills Thursday night
  through early next week.

&&

.UPDATE...
Satellite imagery shows a shortwave lifting thru northeast WY.
Mesoanalysis shows ~500j/kg of mlcape over Powder River & Carter,
and sure enough just recently we have seen a few weak t-storms
develop in this area. Over the next few hours some convection
could lift with the wave to near Miles City & Baker, though not
quite sure about this as there is CIN in the area. Further west
there remains isolated convection over/near the mountains. Have
made some pop/wx adjustments til 04z, after which the night should
be dry. Look for low temps mostly mid 40s to upper 50s. JKL

&&

.DISCUSSION...
Today through Monday...

Temperatures will remain much above average through Thursday for
most of the region. Temperatures will generally be in the 80s F
(10-20 degrees above average). Upper level troughing to the west
will keep temperatures in our western valleys cooler with
temperatures in the 70s F. Tuesday, 20-40% precipitation chances
will spread across the region west of Miles City. This will bring
the potential for showers and weak thunderstorms. Precipitation
amounts are expected to remain light with the NBM keeping the
chances for greater than 0.1 inches of precipitation below 20%.

Starting Friday, a pattern change to cooler and wetter conditions
enters the region. Temperatures cooling to near to below normal
values is high confidence. Precipitation timing and amounts is
much more uncertain. All that can be said at this time is that
there are multiple chances for precipitation Thursday through
early next week. High elevation snowfall is likely during this
period with the first widespread snowfall of the season for all
of our mountain ranges expected. Thursday through Saturday, snow
levels are expected to remain above the 8,000-9,000 ft range.
Starting Sunday, snow levels could drop into the 6,000-7,000 ft
range potentially putting foothills locations in play.
Temperatures Friday and Saturday are expected to be near normal in
the 60s F before decreasing into the 50s F for Sunday and Monday.
Torgerson

.AVIATION...

Isolated to scattered showers and thunderstorms will develop
mainly over the mountains and foothills this evening with a few
showers making into onto the plains. After a break in the
activity tonight, another round of isolated to scattered showers
and thunderstorms is forecast Tuesday evening, this time over the
mountains and plains. With this activity, brief MVFR conditions
and erratic winds are possible (overall moderate chance).
Otherwise, VFR conditions will prevail through Tuesday. Arends/TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 056/084 054/079 053/075 051/064 045/065 043/055 038/051
    01/B    20/U    11/B    55/W    21/B    34/W    44/W
LVM 049/075 045/073 045/070 041/060 037/062 032/052 029/048
    22/W    21/B    23/W    75/W    22/W    44/W    54/W
HDN 051/086 052/081 048/077 048/066 041/066 040/057 036/053
    01/B    40/U    10/U    64/W    21/B    43/W    43/W
MLS 055/087 056/082 052/080 051/068 044/068 043/060 038/056
    20/U    20/U    00/U    43/W    11/B    22/W    32/W
4BQ 056/085 057/080 052/079 051/065 045/067 044/057 037/053
    20/U    10/U    00/U    33/W    21/B    33/W    33/W
BHK 054/088 053/081 050/081 047/068 041/069 041/060 034/056
    20/U    10/U    00/U    32/W    21/B    22/W    22/W
SHR 049/084 046/078 046/078 043/063 037/064 037/055 031/051
    21/B    30/U    00/U    45/W    32/W    34/W    54/W

&&

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

&&

$$
weather.gov/billings