Miles City, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

625
FXUS65 KBYZ 121914
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
114 PM MDT Tue Aug 12 2025

.KEY MESSAGES...

- Warmer (90s) with isolated late day thunderstorms today along
  the MT/WY border. Any storms could produce locally strong wind
  gusts.

- Hot Wednesday with a few triple digit readings possible. Dry
  and breezy conditions Wednesday. Isolated late day thunderstorms
  in the mountains.

- Typical summer weather (temps in upper 80s to mid 90s) for late
  this week through the middle of next week. A low risk of
  thunderstorms each day.

&&

.DISCUSSION...
Through Wednesday Night...

While widespread ridging will continue to dominate the CONUS in
true summertime fashion, a glancing blow from a shortwave will
briefly impact the region tonight into tomorrow. Any convection
with this feature was previously looking pretty meek, and still
does to some extent; however, the chance for precip has come up
slightly as new CAM runs have come in this morning. With the weak
forcing and hot mid to low level temps (up to 15C at 700mb)
storms will likely rely in the terrain to initiate. All of the
HREF members seems to have picked up on this and start to pop
some isolated showers and storms over the Absaroka/Beartooths
around 22z this afternoon. As the convection pushes east, there is
a hint that it may become a little more widespread before
reaching places such as Sheridan. As for the city of Billings, I
opted to add some POPs for a short window this evening but it
looks like most models keep the bulk of the precip off to the
south. All storms should remain unconcerning with the primary
threat being strong winds / downbursts as RAP model soundings
show a stark inverted-v sounding throughout the area.

Wednesday is forecast to be the hottest day of this period as
ridging over the Great Basin expands northwards bringing highs
into the mid to upper 90s for much of the area. As surface flow
will be predominantly westerly, and thus downslope, min RH values
are forecast to dip down into the teens for the western 2/3 of the
CWA. As we work into peak daytime heating, the 500mb jet will
situate itself over western MT. This should allow for some breezy
conditions to mix down during the day Wednesday, especially in the
foothills and gap wind prone areas. Thankfully our fuel moisture
remains high across most of the fire zones and thus fire concerns
remain cautiously low at this time. That being said, there are
some locations, piratically as you get into south-central MT that
are more receptive to fire starts at this time and people will
need to use extra caution as to prevent a spark.
WMR

Thursday through Tuesday...

Ridge flattens somewhat Thursday bringing a reduced chance of
convection and temps 5-10F cooler than Wednesday. Any chance of
weak diurnal convection should be confined to our southern
mountains, but there may be a small risk of nocturnal storms in
far southeast MT late Thursday night as theta-e advection returns
with the low level jet.

Friday through the first half of next week will be characterized
by SW flow aloft, with a strong ridge over the Rockies and high
plains, and a stagnating low off the WA/BC coast. There will be
shortwave pulses embedded within the SW flow, and a reasonable
chance of some monsoon moisture by the weekend, but the devil is
in the details making a specific thunderstorm forecast difficult
at this time. That said, expect at least a low risk of afternoon &
evening thunderstorms over the mountains each day, with activity
spreading to lower elevations on some of these days. Pwats are
expected to be high enough for these storms to produce localized
precip, but they will be high-based and thus wind producers.
Persistent above normal heights will keep temps a little warmer
than normal as well. Overall, a very typical mid to late August
pattern.

As we move to the 2nd half of August it is prudent to keep an eye
on the western Pacific tropics, as typhoons can disrupt the
downstream longwave pattern. Models are hinting at 2 or 3 tropical
systems over the next 1-2 weeks. Stay tuned.

JKL
&&

.AVIATION...

18z Discussion...

VFR conditions will prevail across the forecast area with
relatively light winds (remaining under 15kts). After 22z some TS
may form over the mountains in south central MT (near KLVM)
before moving eastwards. These storms, if they form, will be
isolated in nature. PROB30 groups were included in KLVM, KSHR,
and KBIL as any one of these storms has a small chance of
impacting a terminal. The lost likely site to be impacted would be
KSHR (35% chance) between 00z and 04z. WMR

&&

.PRELIMINARY POINT TEMP/POPS...

    Wed     Thu     Fri     Sat     Sun     Mon     Tue
-----------------------------------------------------------
BIL 063/098 064/090 059/088 061/092 062/090 061/093 062/094
    21/U    00/U    00/U    00/U    12/T    21/U    11/U
LVM 055/094 054/090 049/088 052/089 054/088 053/092 055/092
    21/U    11/U    00/U    11/U    12/T    21/U    11/U
HDN 060/098 062/090 058/089 059/093 060/093 060/094 061/095
    20/U    10/U    10/U    00/U    11/U    20/U    11/U
MLS 062/096 064/088 060/087 063/092 064/092 064/093 065/094
    10/U    00/U    10/U    10/U    11/U    21/U    11/U
4BQ 063/095 065/089 061/088 064/091 064/090 063/091 065/093
    20/U    10/U    10/U    10/U    11/U    21/U    11/U
BHK 058/093 061/087 056/083 060/086 061/087 059/088 061/089
    10/U    10/U    10/U    11/B    21/B    21/U    21/U
SHR 058/093 059/090 055/087 058/091 058/089 057/091 060/092
    31/U    00/U    11/U    11/U    12/T    21/U    11/U

&&

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

&&

$$
weather.gov/billings