864
FXUS65 KBYZ 150317
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
917 PM MDT Mon Sep 14 2026

.KEY MESSAGES...

- Winds decrease tonight.

- Below normal temperatures through the middle of the week.

- Increasing chances for showers and thunderstorms Thursday
  through Saturday.

&&

.UPDATE...
Miles City & Baker saw gusts into the lower 50s (mph) early in the
evening but gusts are now decreasing as we move past sunset, and
as strongest cold advection/pressure rises shift into the western
Dakotas. Have let the High Wind Warning for Custer, Fallon &
Carter Counties expire. JKL

&&

.DISCUSSION...

Rest of Today through Sunday...

Strong upper level low is working through the central portion of
the state late this morning. Showers have exited to the east of
the forecast area for the most part as subsidence builds in on the
back side of the system, with strong west/northwest winds expected
for the rest of this afternoon into the early evening hours.
Strongest winds are expected over the western foothills (US-191
corridor), and over Custer/Fallon/Carter Counties where a High
Wind Warning is in effect for occasional gusts around 60 mph
today.

Winds will diminish this evening and a mostly clear and much
calmer overnight is forecast. Models are hinting at some fog
potential for the northeastern zones and as far west as Billings
along the Yellowstone River valley. Currently have diminishing
northwest winds in the forecast (not very favorable for fog
development), but if the winds do turn north/northeast a bit
faster than currently advertised fog could be a possibility with a
saturated near surface layer forecast. Went ahead and added a
mention of fog to the forecast, will re-evaluate this evening and
see if the wind forecast comes into a more favorable direction
tonight. Lows will be cool in the 30s west and low to mid 40s
east. Forecast temperatures are in the Frost range for the western
foothills and valleys, so protect any vegitation that might get
damaged.

Mostly sunny and dry day on Tuesday with breezy easterly winds
helping to hold temperatures in the 65-75 degree range.

An upper level trof approaches the area from the northwest on
Wednesday, but the energy with it splits in two with a good chunk
dropping south along the west coast on Wednesday, while most of
the rest pushes across southern Canada. This splitting system
won`t generate much more than a few more clouds over the area, but
it will push a reinforcing shot of cooler air into the area on
northerly winds, holding temperatures mainly in the 60s, though SE
areas will see low to mid-70s ahead of the wind shift.

Thursday through the weekend...The upper low along the Pacific
Coast will slowly drift northeastward toward our area over
Thursday and Friday, and then either drift east through Montana
Saturday or just open up and dissipate over the area.
Southwesterly winds aloft will over-run increasing southeasterly
surface winds Thursday and Friday. This sets up a decent
shower/thunderstorm pattern heading into the weekend. Energy and
Pacific moisture ride in on the southwest flow aloft, and plains
moisture and warmer temperatures arrive with the low level
southeast flow. NBM is showing isolated to scattered
showers/thunderstorms Thursday/Thursday night for most of the
area, with higher chances over the western mountains. By Friday
precipitation probabilities ramp up into the 60 to 80 percent
range across the area through Saturday morning. Probabilities for
half an inch or more of precipitation Fri-Sat currently sit at
30% in Livingston, 50% in Billings, 60% in Miles City, and 70% in
Baker. As the upper low drifts into the area the dynamics shift
to more of an instability shower mode and precipitation chances
trend downward into Saturday night with Sunday looking mainly dry
at this point. Thursday/Friday look like the warmest days of the
week with highs in the 70s, maybe some lower 80s along the Wyoming
border from Sheridan county eastward. Temperatures stay mainly in
the lower 70s Saturday and Sunday. Chambers

.AVIATION...

Winds gusting generally to 40-50 kt, strongest in eastern MT, will
diminish from west to east through about 08z Tuesday. As winds
decrease and skies trend toward clearing, there is a low chance of
patchy fog developing east and north of KBIL late tonight into
Tuesday morning. 12z HREF has the probability of visibility
dropping below 3 miles at around 20-30% in that area. Otherwise,
expect VFR conditions through the period. Matos/RMS

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 043/069 045/067 047/076 055/074 053/071 051/073 049/076
    00/U    00/U    01/B    35/T    74/W    30/B    00/U
LVM 035/069 040/071 042/078 049/073 045/070 044/074 044/077
    00/U    00/U    03/T    47/T    54/T    21/U    00/U
HDN 040/071 042/068 043/079 052/075 049/072 045/073 043/078
    00/U    00/U    01/B    25/T    75/T    31/B    00/U
MLS 045/068 050/071 046/078 057/076 054/070 049/072 048/076
    00/U    00/U    01/B    25/T    75/T    42/W    01/U
4BQ 045/070 054/074 049/080 059/078 053/072 050/073 048/077
    00/U    00/U    11/B    25/T    75/T    42/W    11/U
BHK 042/069 048/078 043/077 053/078 050/071 046/073 044/076
    00/U    10/U    01/B    46/T    76/T    52/T    11/U
SHR 037/071 044/071 043/079 051/076 046/072 043/073 041/078
    00/U    00/U    01/B    26/T    65/T    42/W    10/U

&&

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

&&

$$
weather.gov/billings