074
FXUS65 KBYZ 012038
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
238 PM MDT Tue Jul 1 2025

.KEY MESSAGES...

- Turning quite warm this week with many locations in the 90s
  today through Thursday, up to 70% chance of a few triple digits
  Wednesday (Forsyth/Miles City).

- Near-normal temperatures return Friday with daily chances of
  showers and thunderstorms through the holiday weekend.


&&

.DISCUSSION...

Today through Wednesday night...

Currently, a weak wave under ridging with a slight southwest flow
is allowing for isolated showers and thunderstorms to initiate
over the mountains into the foothills. Showers will attempt to
make their way onto the plains through the afternoon, but the lack
of forcing and dry air near the surface will likely prevent any
precipitation from reaching the surface. With this, any
thunderstorms that do form with likely have gusty winds associated
with them. Highs today will be in the mid 80s to mid 90s. Temperatures
Wednesday will be around 10-15 degrees above average with highs
in the upper 80s to near 100 degrees. Areas east of Billings up
the river valley area through Custer Co have up to a 50-70% chance
of hitting 100 degrees. Make sure to take the necessary
precautions for the heat and check on those who are heat
sensitive. Additionally, the region will begin to see an increase
in atmospheric moisture from the southwest as well as from the
Gulf. As ridging starts to move east, a slighty stronger wave
is expected to move through. MUCAPE values will be highest along
the foothills (up to 1000 J/kg), but drops off quickly into the
plains with little shear to support the storms. Atmospheric
conditions become more favorable into eastern MT (MUCAPE~
1000-1300 J/kg and 30-40 kts shear). With this, strong winds will
be the main threat with gusts up to 60 mph. Make sure to stay
weather aware if you have outdoor plans. TS


Thursday through Tuesday...

Active weather is forecast through the holiday weekend as the
upper level flow becomes more southwesterly behind an exiting
upper level ridge. With this, cooler, near normal temperatures and
daily afternoon and evening shower and thunderstorm chances are
in the forecast. Those with outdoor plans for the holiday weekend
should pay close attention to the forecast and remain weather
aware.

Looking a bit closer at the forecast for Thursday through Sunday,
warm to hot conditions are expected to continue just into
Thursday with highs in the 80s to middle 90 degrees F forecast.
While these temperatures will be a few degrees cooler than
Wednesday, mid and low level moisture fetches will make Thursday
feel more humid than Wednesday (dew points in the 50s to 60
degrees F). This additional moisture combined with energy moving
through the southwesterly flow aloft will allow for scattered
afternoon and evening showers and thunderstorms (40 to 60 percent
chance of precipitation across the area). With modest CAPE (500 to
750 J/kg) and shear (30 to 40 knots), most thunderstorms look to
remain below severe levels, but a bit higher CAPE and shear in far
eastern Montana may allow for a few isolated strong to severe
thunderstorms. On Friday (the 4th), a more robust shortwave trough
looks to move through the region during the afternoon into the
overnight hours. With this, high temperatures look to remain in
the 70s and 80s with a moderate to high chance of precipitation
across the area (50 to 80 percent, greatest over the mountains).
While lower values of CAPE (250-500 J/kg) should limit the
coverage of any strong thunderstorms, general thunderstorms are
possible (20 to 40 percent chance) and lightning makes all
thunderstorms dangerous. With the passage of the previously
mentioned wave lingering into Saturday, scattered showers and
thunderstorms are forecast on Saturday once again (20 to 50
percent chance). While the daily chances of precipitation remain
in the forecast for Sunday into early next week, ensembles suggest
the upper level flow may become more westerly. This may cut off
some moisture and allow for more downslope, drying conditions.
Will have to see how things trend. Arends

&&

.AVIATION...

Scattered showers and thunderstorms are expected over the
mountains and foothills this afternoon. Thunderstorms will be most
likely for KLVM and KSHR between 23Z and 03Z this evening. KBIL
has about a 20% chance of seeing an isolated shower and
thunderstorm during this same timeframe. The main threat with any
thunderstorms that form will be gusty winds up to 40 kts. Showers
and thunderstorms are expected to again develop off the mountains
early afternoon Wednesday and track east through the afternoon. TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Wed     Thu     Fri     Sat     Sun     Mon     Tue
-----------------------------------------------------------
BIL 063/096 064/090 062/084 058/081 056/083 057/083 058/090
    22/T    22/T    55/T    63/T    32/T    22/T    21/U
LVM 056/091 055/087 054/080 049/078 048/082 050/084 051/090
    33/T    25/T    67/T    74/T    32/T    22/T    21/U
HDN 062/099 063/092 063/085 057/081 053/085 056/084 056/091
    12/T    22/T    65/T    63/T    32/T    31/U    21/U
MLS 065/099 067/095 067/085 061/081 056/083 059/083 058/090
    01/U    31/B    53/T    63/T    32/T    31/U    31/U
4BQ 064/095 067/093 066/083 060/081 056/082 059/084 059/087
    00/U    31/B    53/T    52/T    32/T    31/U    21/U
BHK 060/092 065/095 064/082 057/078 053/078 054/080 055/085
    10/U    31/B    53/T    53/T    32/T    32/T    31/U
SHR 059/095 058/088 058/081 053/081 050/083 052/083 053/087
    22/T    23/T    55/T    53/T    22/T    22/T    21/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Heat Advisory in effect from 9 AM to 9 PM MDT Wednesday FOR
      ZONES 30>32-173.
WY...None.

&&

$$
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