Bighorn, Montana Weather Forecast Discussion

804
FXUS65 KBYZ 060500
AFDBYZ
Area Forecast Discussion
National Weather Service Billings MT
1100 PM MDT Sun Oct 5 2025
.KEY MESSAGES...
- High probability of a frost or freeze for most of the area
  tonight, and some valley locations again Monday night.
- Dry and warmer starting Monday.
&&
.UPDATE...
Snow over the Bighorns and Pryors has tapered to light snow
showers, and have cancelled the Winter Weather Advisory for these
areas. If you happen to be traveling on US-14 through Burgess
Junction tonight or early Monday, be aware of icy spots. JKL
&&
.DISCUSSION...
Tonight through Sunday...
500 mb shortwave trough axis runs from about NV to central MT
this afternoon with the greatest precipitation coverage and
intensity to the east of this feature. Models bring this trough to
the southeast then eastward tonight into Monday. This pattern
evolution will cause precipitation to diminish from north to south
into Monday morning.
The precipitation that is occurring is falling mainly as rain
below 5000 feet elevation with wet snow in the foothills above
this elevation, and heavier, accumulating snow above 6000 feet.
The Winter Storm Warning and Winter Weather Advisory for our
mountains remain in effect through 6 PM (western mountains) and
midnight (Bighorn and Pryor Mountains). (The snow level has been
fluctuating today, and at one point was around 4500 feet.) The
Beartooth and Red Lodge Foothills could receive 0.5-1" of new snow
through this evening from additional light snow. 12z HREF
suggests about a 20% chance of some locations within those areas
receiving the 1" amount of snow, with smaller amounts more
probable. This snow could produce a few slick spots on foothill
roads later tonight as temperatures cool with still high relative
humidity preventing much drying.
Otherwise, sky conditions should display a clearing trend from
north or northeast to the south overnight. The partly cloudy to
mostly clear skies should facilitate surface cooling with many
locations in our forecast area having a forecast low temperature
near or below freezing. Western foothill locations are forecasted
to drop into the 20s tonight. The area least likely to observe
sub-freezing temperatures is east/southeast of Billings where
cloud cover will probably persist long enough to prevent the
stronger cooling that is expected elsewhere. Please be aware if
you have sensitive plants.
500 mb ridging will then dominate our weather Monday into Friday
with generally dry and warmer conditions. Models are in good
agreement on the large-scale pattern through this time. There is
some risk of another frost/freeze Monday night; please view our
Weather Story for more details on that.
For next weekend, 500 mb height clusters generally agree on the
idea of a trough over the eastern Pacific/Pacific
Northwest/Northern Rockies region...but differ on location/timing.
The evolution suggests an increasing chance of precipitation from
west to east for most of the forecast area Friday night into
Saturday evening and then a continuation of the chance of
precipitation into Sunday. The chance of precipitation looks to
reach about 40% near Billings, 50% near Livingston, 30% near
Sheridan, and 20% or so near Miles City/Baker Saturday-Sunday.
High temperatures will generally rise from the 50s Monday to the
60s and 70s Wednesday through Saturday, before a potential cooldown
next Sunday. NBM 10th to 90th percentile data shows that the
uncertainty in the high temperature forecast increases toward the
later part of the week, with the range of high temperatures at
Billings being 63-73F Thursday, then 64-79F Saturday, and 50-70F
Sunday. RMS
.AVIATION...
Precip in our south (i.e. near KSHR) has tapered to light
rain/snow showers, and this light precip will end by sunrise.
There remains areas of low clouds with MVFR ceilings along the
western foothills (i.e. near KLVM, K6S0 & KHWQ) and this will be
slow to diminish through the night. Later tonight, all TAF sites,
excluding KMLS, have a 20-40% chance of seeing fog/low stratus
into early Monday morning, creating MVFR/IFR conditions. Will need
to monitor this through the night. Any fog/stratus will dissipate
by mid-morning Monday. Expect mountain obscurations through the
night. Look for VFR regionwide Monday as high pressure aloft
builds over the region. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Mon     Tue     Wed     Thu     Fri     Sat     Sun
-----------------------------------------------------------
BIL 034/058 039/066 042/071 042/069 042/074 050/077 044/059
    10/U    00/U    00/U    00/U    00/U    12/R    44/R
LVM 026/057 029/066 034/070 036/070 038/075 044/071 036/055
    00/U    00/U    00/U    00/U    00/U    24/R    55/R
HDN 032/059 032/068 034/072 037/070 038/075 044/079 042/062
    10/U    00/U    00/U    00/U    00/U    12/R    43/R
MLS 032/060 035/068 039/072 040/070 041/076 046/079 046/063
    00/U    00/U    00/U    00/U    00/U    01/U    22/R
4BQ 034/057 036/064 041/070 041/069 043/075 050/079 047/063
    10/U    00/U    00/U    00/U    00/U    11/U    22/R
BHK 028/059 033/066 039/072 040/070 040/074 045/079 043/064
    00/U    00/U    00/U    00/U    00/U    01/U    21/B
SHR 032/056 029/065 032/071 036/071 038/076 044/078 040/063
    31/U    00/U    00/U    00/U    00/U    12/R    33/R
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings

NWS BYZ Office Area Forecast Discussion