120
FXUS65 KBYZ 261843
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
1243 PM MDT Sat Sep 26 2026

.KEY MESSAGES...

- Unsettled conditions Sunday into Monday will keep seasonable
  temperatures around and introduce small to moderate chances for
  precipitation.

- A few strong storms are possible Sunday evening into the
  overnight hours across southeast MT. Main threats will be heavy
  rain, small hail and gusty winds.

&&

.DISCUSSION...

Today through Friday...

Following the shortwave and associated cold front that moved
through this morning, increasing southwest flow is expected into
Sunday. Although models keep with the trend of splitting the
strongest energy to the north and south, weak energy in the low
levels look to provide enough forcing to potentially produce a few
stronger thunderstorms Sunday evening into the overnight hours.
One caveat to the potential for thunderstorms Sunday evening is
model soundings seeming pretty consistent with a cap or inversion,
preventing thunderstorm development. That being said, if the
instability present (500-1000 J/kg MUCAPE) is able to be tapped
into, the bulk shear present (35-45kts) would support a few strong
storms capable of producing heavy rain, small hail and gusty
winds. Currently, there is about a 30-50% chance for at least a
quarter inch of precipitation for the higher terrain and the
MT/Dakotas border. Any stronger thunderstorm will be capable of
producing locally higher amounts with atmospheric moisture at
150-200% of normal. As trailing energy from this system moves
over the region, small chances for showers will remain in the
forecast for Monday. As a more westerly flow aloft moves in
Tuesday, conditions look to become dry with seasonable
temperatures in place. Towards the end of the week there is a lot
of spread, but ensembles are hinting at a cooler trough moving
through. Will be something to watch through the week. TS


.AVIATION...

18Z discussion.

Winds will turn out of the east for all TAF sites
this afternoon and evening. Occasional high clouds will move in
from the west today, increasing by Sunday morning. Archer

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 046/064 047/068 046/074 050/075 048/070 048/070 046/062
    02/W    21/E    00/U    00/U    00/U    00/B    11/B
LVM 038/063 039/068 038/074 044/074 041/072 042/072 040/064
    01/E    12/W    00/U    00/U    00/U    01/B    11/B
HDN 042/068 045/068 043/075 046/076 045/072 045/072 044/064
    02/W    21/E    10/U    00/U    00/U    00/B    11/B
MLS 045/068 051/069 047/073 049/074 048/069 048/070 047/062
    02/W    21/E    00/U    00/U    00/U    00/B    11/B
4BQ 047/069 053/068 048/073 050/075 049/070 048/072 047/063
    02/W    42/W    10/U    00/U    00/U    00/U    21/B
BHK 044/069 049/069 046/073 047/075 045/068 044/070 043/062
    02/W    53/W    10/U    00/U    00/U    01/B    11/B
SHR 041/068 046/065 041/071 042/074 043/071 043/072 041/063
    01/B    35/W    30/U    00/U    10/U    01/U    12/W

&&

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

&&

$$
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