545
FXUS65 KBYZ 291940
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
140 PM MDT Sun Jun 29 2025

.KEY MESSAGES...

- Turning warm this week with many locations in the 90s by Tuesday
  and Wednesday. Increased risk of heat impacts Tuesday and
  Wednesday.

- Chance of thunderstorms begins to increase again by the middle
  of the week.

&&

.DISCUSSION...

Through Monday night...
Drier air continues to build in from the northwest this
afternoon. This will help confine isolated convection to areas
near the Bighorn mountains eastward across southern portions of SE
Montana this afternoon. By this evening convection should be
mainly south and east of the forecas area. Can`t rule out an
isolated thunderstorm with gusty winds and small hail, but the
severe threat looks to remain generally southeast of Montana
today.

Ridging builds over the area aloft with much drier air (PWATS
~0.5in) tonight through Monday night for mostly clear and dry
conditions to start the work week. Highs Monday will trend warmer,
into the mid 80s most areas. Chambers

Tuesday through Sunday...
There is moderate to high confidence that ridging with above
normal temperatures is in store this week. The latest forecast has
temperatures in the 80s and 90sF with the warmest days being
Tuesday, Wednesday, and Thursday. The latest heat risk forecast
indicates moderate (2/4) impacts on Tuesday and moderate to high
impacts (2/4 to 3/4) on Wednesday, and minor to moderate (1/4 to
2/4) on Thursday. This is subject to change as we are still a few
days away, but it is important to continue monitoring the forecast
and plan activities accordingly. Wednesday looks to be the
warmest day of the week, especially north and east of Billings
where the probability for 100F or greater temps is 25-60%. The
greatest probabilities are currently shown to be in the river
valleys and in northern Rosebud and Custer counties.

Along with the warmth, a push of monsoonal moisture is depicted by
models moving into the region beginning Tuesday. This will bring
the chance for showers and thunderstorms into next weekend.
Although it is too soon to determine the strength and coverage of
storms, continue to monitor the forecast if you have outdoor
plans.

Overnight lows this week will be in the 50s and 60s. In similar
locations to the chance for 100F, there is a 25-70% chance of
overnight temps being greater than 70F, Wednesday night.

Ensembles are in moderate confidence that a Pacific system will
help push the ridge axis east, Thursday into the weekend. This
is shown to bring temperatures back around average (80sF) and an
increased chance for precipitation. Matos

&&

.AVIATION...
Isolated afternoon and evening showers and thunderstorms are
possible from the Bighorn mountains east across southern portions
of southeast Montana. Local MVFR conditions and gusts to 40kts are
possible near precipitation areas. Otherwise VFR conditions and
generally light winds can be expected for the next 36hours.
Chambers

&&

.PRELIMINARY POINT TEMP/POPS...

    Mon     Tue     Wed     Thu     Fri     Sat     Sun
-----------------------------------------------------------
BIL 055/085 058/093 063/095 064/090 063/084 059/081 058/087
    00/U    00/U    11/B    22/T    44/T    33/T    22/T
LVM 046/085 050/092 055/090 056/086 054/079 051/078 051/085
    00/U    01/U    22/T    24/T    55/T    44/T    32/T
HDN 052/086 055/095 061/097 064/091 063/086 058/083 056/087
    00/U    00/U    11/B    22/T    54/T    43/T    32/T
MLS 054/085 057/095 064/098 068/096 067/087 061/084 059/088
    00/U    00/U    10/U    21/B    53/T    33/T    22/T
4BQ 055/083 056/093 063/095 068/093 066/085 060/081 059/085
    00/U    00/U    10/U    21/B    53/T    32/T    22/T
BHK 051/082 053/090 059/094 064/093 063/086 057/081 054/085
    00/U    00/U    10/U    21/B    53/T    33/T    22/T
SHR 048/083 052/092 058/093 060/088 058/081 053/079 051/084
    10/U    01/U    11/U    23/T    55/T    34/T    22/T

&&

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

&&

$$
weather.gov/billings