Colstrip, Montana Weather Forecast Discussion

533
FXUS65 KBYZ 102129
AFDBYZ
Area Forecast Discussion
National Weather Service Billings MT
329 PM MDT Wed Sep 10 2025
.KEY MESSAGES...
- Above normal temperatures through Thursday.
- Periods of isolated to scattered showers and thunderstorms today
  and Thursday. Best chance of precipitation is Thursday.
- A few thunderstorms could become strong to severe on Thursday
  afternoon and evening. Main threat is strong winds and hail.
- Increased chance for precipitation (50-80% chance >0.25in,
  greatest east of Billings) and cooler temps Friday into Sunday.
&&
.DISCUSSION...
Through Thursday night...
Our current synoptic pattern continues to be dominated by a ridge
of high pressure to our east and a large low pressure system to
our west. As the low pressure system to our west gradually
approaches our region through Thursday, we will see increasingly
diffluent mid level flow, increased atmospheric moisture both at
the surface and aloft, and multiple disturbances track northeast
through the area. This will bring periods of isolated to scattered
showers and thunderstorms to the area, with the best chance of
precipitation existing on Thursday (15 to 70 percent, greatest
over south-central Montana where the upper level support is
strongest). A few thunderstorms may become strong to severe
Thursday afternoon and evening with strong winds and hail being
the main threats.
Looking a bit closer at the chance of precipitation, isolated to
scattered showers and thunderstorms are forecast this afternoon
and evening. At this time, uncertainty remains on the spacial
extent of this activity as there is a mid- level cap in place
under the influence of the upper level ridge to our east. However,
a few high resolution models indicate this cap may erode for a
few hours this afternoon and early evening, allowing convection to
develop. Should this occur, a few stronger storms are possible in
eastern Montana before sunset with gusty winds being the main
threat. The probability for any severe thunderstorms remains low.
While any activity that forms today will likely taper off this
evening, a developing low level jet over eastern Montana may allow
showers to linger overnight in eastern Montana (10 to 20 percent
chance). By Thursday morning, another wave of isolated to
scattered showers looks to lift north over south-central Montana.
With this, precipitation looks to be light. By Thursday afternoon
and evening, a more robust round of precipitation is expected.
With modest CAPE and shear, and the passage of a Pacific cold
front, a few strong to severe thunderstorms could develop over the
plains of Montana and Wyoming. As previously mentioned, the main
threats are strong winds and hail. Winds could be locally enhanced
along the front where convection exists. The showers and
thunderstorms Thursday look to lift north and east out of our area
by late in the evening.
Temperatures Thursday will remain warm in the upper 70s to lower
90s, warmest in eastern Montana. Overnight lows will range in the
50s and 60s tonight and 40s and 50s Thursday night. Arends
Friday through Tuesday...
Strong trough and a developing upper low are shown moving into
the region by ensembles through the weekend. Cooler and wetter
conditions will accompany this system.
Models have come into better agreement that the upper low will
develop along the Montana/Canadian border and lift north. This has
large implications for the forecast area, with the low lifting
north the chance for widespread and long lasting precip will
decrease. Currently, the chance for precipitation will increase
from west to east, late Friday morning through the afternoon.
Overall the chance for precipitation on Friday is moderate to high
(50-80%) across the area. Depending on where the low develops,
isolated to scattered thunderstorms are possible with modest
instability remaining from Thursday. The chance for precipitation
over the weekend is currently low to moderate (15-40%). Storm
total rainfall amounts have decreased with the latest forecast,
though 0.1 to 1 inch of rainfall is depicted Friday morning
through Saturday morning. The best chance for more than 0.25" of
QPF largely exists east of Billings, and the best chance for at
least 0.50" of QPF exists in and east of Rosebud County.
Billings and west will generally see amounts between 0.1" to
0.25".
High temperatures will be in the 70s to low 80s Friday, cooling
into the upper 60s and 70s Saturday. A climb back into the 70s and
80s is shown by ensembles, Sunday and Monday.
For relevant precipitation probability graphics, please visit
weather.gov/byz. Matos
&&
.AVIATION...
There is a slight chance of showers and thunderstorms this
afternoon and evening across much of the area. While uncertainty
remains on the extent of this activity, any shower or thunderstorm
that develops could produce gusty and erratic winds. Brief MVFR
conditions are also possible under the strongest cells. By late
this evening into tonight, a low level jet looks to develop over
eastern Montana. This could keep shower activity going into the
night, as well as bring some low level wind shear to airports
around KMLS and KBHK. Over the mountains of south- central Montana
late tonight into Thursday morning, another round of scattered
showers looks to move into the region. The chance of showers and
thunderstorms then spreads across the region once again Thursday
afternoon and evening. Arends
&&
.PRELIMINARY POINT TEMP/POPS...
Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 061/084 054/080 055/075 054/077 054/082 053/077 053/074
    24/T    33/T    55/T    22/W    12/W    33/W    33/W
LVM 051/079 044/075 044/073 044/074 045/077 044/073 044/074
    25/T    34/T    45/T    22/T    13/T    34/T    33/W
HDN 057/086 052/082 053/074 050/077 050/082 050/077 050/075
    23/T    42/T    66/T    32/W    11/U    33/W    43/W
MLS 060/089 056/083 057/073 054/077 053/082 053/078 053/074
    22/T    52/W    77/T    53/W    21/U    32/W    43/W
4BQ 062/088 056/082 058/072 052/074 052/080 053/077 052/072
    21/U    21/U    76/T    42/W    11/U    22/W    43/W
BHK 057/091 054/083 054/072 050/074 050/081 050/079 049/072
    21/B    21/U    78/T    63/T    21/U    22/W    43/W
SHR 054/086 049/079 048/071 044/074 046/080 047/076 046/073
    22/T    24/T    77/T    32/T    11/U    23/W    44/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings

NWS BYZ Office Area Forecast Discussion