685
FXUS65 KBYZ 011920
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
120 PM MDT Sat Nov 1 2025

.KEY MESSAGES...

- Windy conditions continue this weekend. The strongest winds are
  forecast in the common gap wind prone areas.

- Mild conditions expected next week with highs in the 50s to
  lower 60s most days. Periods of showers and wind at times.

&&

.DISCUSSION...
Saturday through Friday...
As heights continue to rise with the building ridge, the main
story in the near term remains the gusty winds. The first area of
concern is the Livingston to Nye area with the terrain/gap winds
overnight tonight into Sunday morning. The setup seems to be quite
good as multiple models are showing a pressure gradient between
IDA-LWT of 13mb+ and a delta-T of 10F between LVM and Mammoth. As
the 700mb jet, with 50kt winds, sags southwards the clouds are
expected to quickly clear out this evening allowing for fast
radiational cooling and the development of the surface inversion.
Winds will likely get going before midnight and then peaking in
the very early morning hours potentially up to 70mph at LVM.

As we transition into the early morning hours of Sunday there is a
decent signal amongst the short term models to start to favor the
Big Timber area for the strongest winds. Ahead of the approaching
front a hybrid type event seems to be possible as winds slowly die
down at LVM with the pressure gradient weakening as they
increase at Big Timber with the gap flow between the Absarokas
and Crazys as the strong 700mb winds duct below the inversion.
There is still a big question regarding just how strong these
winds will get as the front, and associated strongest winds, may
lag into mid morning which would allow the inversion to erode
before its arrival.

Harlowton`s threat comes later in the day. With the arrival of the
front in the mid morning the chance of precip, and clouds, should
be well out of the way for the winds to take advantage of the
mixed low levels. Additionally, directly behind the cold front CAA
will aid in providing downward transport of the winds which may
allow the Harlowton area to see its strongest winds early
afternoon. There is also always the potential for some stronger
gusts as the winds funnel through any number of the various gaps
in the terrain in that region. In addition to all of these gap
prone areas, the entire CWA will see some breezy winds during the
day Sunday as the 700mb jet with 40kt winds should have a decent
period to mix down in the afternoon.

As we move into early to mid week it almost looks like deja-vu as
another shortwave is forecast to ride along the ridge which could
give us another chance at some stronger winds, especially for
those gap prone areas. While the mountains may pick up a few
inches of snow with this system, it will still be mostly dry for
most of the region. Later in the week there is a signal that a
potentially stronger trough may make its way into the Northern
Rockies which could provide us another chance for gusty winds
gusts and also maybe some more widespread precipitation. WMR



.AVIATION...

Strong southwest winds will continue over the Beartooth
foothills, including KLVM, with gusts around 30-45 kts, increasing
to 45-55 kts after 02Z through about 15Z Sunday before backing
off. Winds will turn west/northwest, with gusts of 25-35 kts
expected for all TAF sites by Sunday afternoon and stronger gusts
around 40-50 kts possible near K1KM. In addition, areas of local
wind shear are expected to increase late today and continue
through early Sunday. BT

&&

.PRELIMINARY POINT TEMP/POPS...

    Sun     Mon     Tue     Wed     Thu     Fri     Sat
-----------------------------------------------------------
BIL 045/057 032/053 035/054 034/058 041/057 037/055 035/051
    12/W    00/B    24/W    10/B    11/B    14/W    21/B
LVM 041/054 028/052 035/053 035/059 037/052 035/051 030/049
    14/W    01/B    45/W    11/E    42/W    36/W    31/B
HDN 040/057 029/055 031/054 031/059 038/059 033/057 033/051
    12/W    00/B    13/W    10/B    12/W    14/W    31/B
MLS 041/058 028/053 033/053 030/058 039/059 033/055 033/049
    11/N    00/B    12/W    10/B    11/B    13/W    21/B
4BQ 041/057 031/054 034/054 032/059 042/057 034/056 036/049
    00/N    00/B    01/E    10/B    01/B    02/W    21/B
BHK 039/058 025/053 030/058 027/054 035/056 030/054 030/049
    00/N    00/B    01/E    00/B    11/N    01/B    21/N
SHR 038/060 026/055 030/054 029/060 035/056 030/056 028/049
    01/N    00/U    11/B    10/B    12/W    13/W    31/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Warning in effect from 9 AM to 8 PM MDT Sunday FOR
      ZONES 63-228.
     Wind Advisory in effect until 11 AM MDT Sunday FOR ZONES
      65-66.
     High Wind Warning in effect from 9 PM this evening to 8 PM
      MDT Sunday FOR ZONES 141-172.
WY...None.

&&

$$
weather.gov/billings