679
FXUS65 KBYZ 161910
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
110 PM MDT Mon Jun 16 2025

.KEY MESSAGES...

- Slight risk (2/5) of severe thunderstorms today across much of
  the area. Main threats are large hail, strong winds and heavy
  rain. There is a small chance of tornadoes over south-central
  Montana and north-central Wyoming today as well.

- Scattered shower and thunderstorm chances continue into
  Tuesday.

- Quieter weather pattern for the second half of the week.

&&

.DISCUSSION...

Rest of Today through Tuesday Night...

Scattered showers and thunderstorms will move through the region
from west to east this afternoon and evening. Look for this
activity to develop off the higher terrain early this afternoon as
a subtle mid- level shortwave trough tracks over the area. With
moderate instability (MUCAPE values modeled around 750 to 1750
J/kg) and strong deep layer shear (40 to 55 knots), some strong to
severe thunderstorms are possible across much the area (Slight,
2/5 risk of severe weather from the Storm Prediction Center). With
dewpoints remaining in the 50s for many areas, and generally
straight line hodographs, large hail and strong winds are the main
threats today. Heavy rain is also possible under any strong
thunderstorm that develops. While the chance is low (2%), a brief
tornado or two is possible over south-central Montana and north-
central Wyoming today as well. If you have outdoor or travels
plans generally between 2 and 10 PM MDT today, make sure to stay
weather aware.

While the first round of showers and thunderstorms will exit our
east late this evening, another weak, embedded shortwave trough
tracking through the region will keep the chance of precipitation
going over southern Montana and northern Wyoming tonight into
Tuesday morning (30 to 70 percent chance, greatest over the higher
terrain).

On Tuesday, scattered showers and isolated thunderstorms are
possible once again (25 to 70 percent chance, greatest over the
mountains). With weaker instability (MUCAPE values around 500 to
1000 J/kg) and shear (20 to 30 knots), no severe thunderstorms are
expected at this time. However, stronger cells could still
produce small hail and gusty winds. Arends

Wednesday through Sunday...

Ensembles are in good agreement that we will be transitioning to
a drier and warmer pattern through the middle to latter part of
the week. Ridging builds over the inter-mountain west Wednesday
and Thursday with weak downslope flow pushing the bulk of low
level moisture that has been over the region for the last several
days to the east. A mainly dry forecast with limited convection
can be expected Wednesday into Friday. The ridge starts to slide
east by the second half of Friday, as a large trough and
associated upper low push inland into the Pac NW. As the trough
pushes farther inland into the Northern Rockies into the weekend,
daily shower and thunderstorm chances are possible (30-60% chance,
greatest over western areas). This pattern typically promotes
severe thunderstorm development, so this is something to watch
moving forward.

Temperatures will range from the upper 70s to 80s on Wednesday, to
the 80s on Thursday and Friday. Temperatures trend back towards
normal by Sunday. Depending on the strength of the upper trough,
it is possible that some places could have highs in the 60s Sunday
into early next week. STP

&&

.AVIATION...

Scattered showers and thunderstorms will develop over western
areas this afternoon, spreading eastward through the evening
hours. Showers and thunderstorms will decrease overall into the
overnight hours, though some areas of isolated showers could
persist overnight. MVFR conditions are possible with the
strongest thunderstorm activity. Some storms may be severe and
produce large hail and winds gusts up to 55 kts. Expect occasional
mountain obscuration. STP

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 054/077 054/085 056/087 059/087 057/082 051/068 045/072
    53/T    00/U    00/U    22/T    21/U    44/W    21/B
LVM 048/075 048/083 050/087 052/085 050/078 041/064 038/070
    64/T    00/U    01/U    33/T    33/T    55/T    32/T
HDN 054/076 048/086 055/088 059/089 057/084 051/069 045/074
    75/T    10/U    10/U    21/U    21/U    54/W    31/B
MLS 056/077 055/085 057/089 061/086 061/087 054/069 047/071
    43/T    20/U    10/U    42/W    31/U    43/W    31/B
4BQ 055/073 053/084 057/088 060/087 063/090 054/069 047/068
    76/T    20/U    10/U    11/U    21/U    22/W    32/W
BHK 054/075 051/083 054/089 059/084 059/087 055/070 044/068
    33/T    20/U    10/U    32/W    21/U    32/W    31/B
SHR 050/071 048/081 053/088 056/087 057/086 049/068 042/070
    87/T    10/U    00/U    11/U    11/U    34/T    32/T

&&

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

&&

$$
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