943
FXUS65 KBYZ 031912
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
112 PM MDT Sun Aug 3 2025

.KEY MESSAGES...

- Better chance of thunderstorms Monday, a few strong to severe
  storms are possible.

- Seasonal temperatures in the upper 80s to lower 90s and mainly
  dry Tuesday through Thursday.

- Much cooler (highs in the 70s) and unsettled conditions
  developing for Friday through the weekend.

&&

.DISCUSSION...

Through Monday night...

Less thunderstorm activity today and any storms that do form will
be less intense than what has occurred over the past few weeks.
Atmospheric moisture continues to decrease over the area,
especially over central and western zones where PWAT values range
from 0.3 to 0.7 inches. Still have better moisture along the
eastern state line this afternoon, but even these values decrease
under an inch by early evening. Less moisture means fewer storms
and along with weak shear means less intense storms. Could still
see isolated wind gusts in the 40 to 50 mph range due to
evaporative cooling into the drier lower levels of the atmosphere.
Convection ends pretty quickly this evening with a mostly clear
and quiet overnight. Temperatures Monday morning will range from
the upper 40s to lower 50s west to the lower 60s central and east.

We have been watching a disturbance coming out of the PacNW in the
models for the past few days. Overall this feature has kept west
of the area resulting in a fairly dry forecast. Latest model runs
have trended further east and south with this feature resulting in
better thunderstorm chances and stronger storm potential. As the
system approaches will see a surge in low level easterly winds
which will do two things, increase low level moisture (PWATs) and
provide stronger shear as easterly winds down low veer to stronger
southwest winds in the mid levels. HREF thunderstorm timing shows
development in the west around 2pm, into central zones (Billings)
as early as 4 but most likely closer to 6pm, and into Miles City
around 9pm, lingering over far eastern zones (Baker, Ekalaka) into
the early morning hours. While hail is a threat tomorrow, strong
wind gusts and locally heavy rainfall (from Billings east) will be
the main threats with storms.

Being a pre-frontal day, high temperatures will be a few degrees
warmer tomorrow, mainly in the lower 90s ahead of thunderstorms.
Lows Monday night will be in the 40s over the western foothills,
with 50s to near 60 elsewhere. Chambers

Tuesday through Sunday...

Pacific disturbance drags a weak front through the area from the
west/northwest Monday night which brings drier more stable air
into the area for Tuesday. High temperatures Tuesday drop into the
mid 80s under sunny skies. Low chances for afternoon/evening
thunderstorms will persist along the eastern state line, but most
likely activity will stay east into the Dakotas.

Southwest flow on Wednesday will bring warmer air back into the
area with highs back to the lowe 90s. Overall looks like a dry day
across the area with light winds. Low level jet redevelops
Wednesday night with moisture advection over SE Montana brining a
slight chance (20%) for showers or a thunderstorm overnight into
early Thursday morning.

Big changes begin on Thursday as a trof over the NE Pacific drops
into western Canada and begins to move our direction. This digging
system is thanks to the semi-permanent Summer ridge over the Great
Basin sagging south and east. Heights aloft drop through the day
Thursday with models hinting at winds turning northerly during the
afternoon signaling cooler air advecting into the region. Better
instability with cooling air aloft should increase precipitation
chances from late in the day Thursday through Friday as the upper
system drops down to park itself over Montana by Saturday. Highs
in the upper 80s to lower 90s on Thursday drop into the 70s for
Friday through Sunday. Precipitation chances look strongest
through Friday night, diminishing Saturday into Sunday. However,
this will depend a lot on how far south the upper low moves over
the weekend, further south the more precipitation potential for
our area. If you have outdoor plans for the weekend be prepared
for more fall-like conditions, and wet for at least the first half
of the weekend. Chambers

&&

.AVIATION...

Isolated showers and thunderstorms are expected to begin
developing near KLVM around 23Z, with KBIL and KSHR just after 0Z.
These locations have about a 20% chance of getting a shower. Any
thunderstorms that form have the potential to produce wind gusts
up to 30-40 kts. TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Mon     Tue     Wed     Thu     Fri     Sat     Sun
-----------------------------------------------------------
BIL 061/091 060/086 058/091 062/090 060/079 055/075 055/078
    21/U    41/U    00/U    11/B    34/T    53/W    11/B
LVM 051/085 049/083 049/089 052/085 050/076 047/073 046/078
    23/T    41/U    00/U    12/T    45/T    43/T    11/U
HDN 059/094 059/086 056/092 060/091 058/080 054/076 052/078
    21/U    41/U    00/U    11/B    34/T    53/W    11/B
MLS 062/093 064/086 059/093 064/092 061/081 057/076 056/078
    11/U    53/T    00/U    12/T    44/T    53/T    11/B
4BQ 063/091 063/086 060/092 064/094 062/083 057/076 055/076
    21/U    31/U    00/U    11/U    33/T    63/T    21/B
BHK 059/090 062/084 057/089 061/090 059/081 055/075 053/076
    21/U    44/T    10/U    12/T    43/T    53/W    11/B
SHR 056/090 055/086 054/092 058/092 055/082 052/075 049/075
    21/U    21/U    00/U    01/B    23/T    53/T    21/B

&&

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

&&

$$
weather.gov/billings