740
FXUS65 KBYZ 082045
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
245 PM MDT Sun Jun 8 2025

.KEY MESSAGES...

- Smoke from Canadian wildfires will bring hazy conditions and
  reduced air quality through Monday over portions of the area.

- Warm and dry through Tuesday (highs in 80s to near 90F).

- There is daily potential for thunderstorms beginning late
  Tuesday and continuing through next weekend; some severe
  thunderstorms are possible.

&&

.DISCUSSION...

Through Monday night...

Rising heights throughout the short term will bring a pattern
change to the region. Downsloping winds rapidly increase
temperatures for Monday with highs near 80 F along the Dakotas
border and mid to high 80s F elsewhere. The NBM is giving
locations along the Yellowstone and Musselshell rivers a 20-40%
chance of getting over 90 F, including Billings and Roundup.
Dewpoint temperatures will be in the 30s F Monday creating large
dewpoint depressions and minimum relative humidity values in the
teens.

Smoke will continue to negatively impact air quality over
southeast Montana through Monday. Current observations and model
guidance indicates the greatest smoke impacts will be west of
Rosebud county. The upper level pattern change to westerly
downsloping winds could reduce smoke concentrations Monday night
into Tuesday morning though this remains uncertain. Torgerson


Tuesday through Sunday...

The weather pattern through the week will consist of WSW flow
downstream of a Pacific coast trof and broad ridging over the
north central U.S. In fact, the longwave pattern stagnates such
that there is persistent troffing over the north Atlantic and an
anomalous blocking ridge over Norway. All of this helps give
credence to the overall setup for the week, which will consist of
daily chances of thunderstorms in our region, some possibly severe
and producers of heavy rain. Courtesy of a plains moisture tap,
expect pwats to rise to ~1" or up to 2 standard deviations above
normal beginning Tuesday night. The probabilities for seeing
dewpts reach 60F climb to 30-50% in our east by late week.

SPC has highlighted Tuesday with a marginal risk of severe
t-storms in our west. Moisture and instability will be on the
increase, as will bulk shear, but late day forcing is weak and
this will limit the severe potential somewhat. It is a transition
day, however. A stronger wave is expected to arrive late Wednesday
and the air mass will be more primed for severe storms by then,
though shear may be weaker. This is a day to watch as there is
potential for strong to severe t-storms and heavy rain. The wave
will move slowly thru the region Wednesday night keeping the
chance of showers/t-storms going over our north and east through
the night and into Thursday morning. On the back side of this wave
there`s an expectation of a period of subsidence...so Thursday
convective potential appears to be lower than Wednesday. Moving to
Friday and the weekend, the potential for t-storms continues, but
there may also be a surge of warmer mid level temps from WY into
southeast MT, which could shift t-storm potential to mostly our
west and north. Tough to say here. Ensemble means have trended a
bit westward with the location of the PacNW trof so this is
something to watch. The lee side air mass will remain moist and
unstable though, and at some point by next weekend we should see
stronger Pacific energy move across the northern Rockies. Please
stay in tune with the forecast as t-storms will have potentially
significant impacts to outdoor activities.

Tuesday still looking like the warmest day of the extended period
with 80s to lower 90s for highs, though we could introduce
northeast winds and weak cool advection by midday (which would
impact t-storm potential). Wednesday and Thursday will trend
cooler but not cold, with near normal temps Thursday. There is
ensemble consensus for a warming trend Friday and next weekend,
which depends on the location of the upstream trof and strength of
additional shortwaves.

As a final note, river/stream levels are in very good shape and we
don`t expect the upcoming convective rains to be concerning.
However, burn scars (including Elk) will need to be watched given
pwats as high as they will be and potential for locally heavy
rain.

JKL
&&

.AVIATION...

The main aviation hazard over the next 24 hours will be visibility
reductions due to wildfire smoke. Slant range visibility will be
reduced while surface visibility reductions are less certain. The
worst smoke impacts tonight and Monday will be west of Rosebud
County including the TAF sites of KBIL, KLVM, and KSHR. Torgerson


&&

.PRELIMINARY POINT TEMP/POPS...

    Mon     Tue     Wed     Thu     Fri     Sat     Sun
-----------------------------------------------------------
BIL 049/088 060/088 058/085 057/079 054/083 057/085 058/088
    00/K    02/T    44/T    64/T    23/T    22/T    22/T
LVM 047/085 053/086 050/081 050/077 049/080 050/083 051/084
    00/K    03/T    46/T    84/T    34/T    22/T    23/T
HDN 045/087 055/089 057/086 056/080 053/084 056/086 058/089
    00/K    01/U    43/T    64/T    22/T    22/T    32/T
MLS 044/086 056/090 059/084 056/075 054/081 059/086 060/088
    00/U    00/U    42/W    76/T    42/T    31/U    42/T
4BQ 046/081 056/090 058/082 057/077 055/081 058/084 060/086
    00/U    00/U    31/B    55/T    32/T    21/U    32/T
BHK 039/081 052/085 053/077 051/070 051/076 053/081 056/083
    00/U    00/U    32/W    57/T    42/T    31/B    32/T
SHR 044/081 053/087 052/083 053/079 051/083 055/085 056/086
    00/K    02/T    34/T    53/T    23/T    22/T    22/T

&&

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

&&

$$
weather.gov/billings