036
FXUS65 KBYZ 191959
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
1259 PM MST Wed Nov 19 2025

.KEY MESSAGES...

- Above normal temperatures continue through the weekend.

- Breezy winds along the western foothills this weekend; a period
  of stronger winds possible Sunday night and Monday.

- Colder temps and possibly light snow by middle of next week
  (Tue/Wed).

- Wintry travel impacts possible for Thanksgiving and the holiday
  weekend...monitor the forecast!

&&

.DISCUSSION...
Isolated light showers continue to affect an area from Judith Gap
to Forsyth and parts of far southeast MT as of 1930z. Conditions
have cleared to the west, but we are starting to see showers
develop over the western mountains (w/ impressive-for-November
moderate cu seen as this is being written, looking out our office
window to the SW toward the Beartooths). PV axis associated with
weak trof to our west is over central MT and the cooler air aloft
along with daytime heating is yielding mid level lapse rates of
~7c/km. So there is some instability to work with. Low level winds
have turned to the NE over our west as surface high sags slowly
thru north central MT...and the combination of weak ascent, steep
lapse rates and upsloping low level winds should allow for at
least isolated showers to develop over our west between now and
sunset, and probably a bit longer per the PV axis itself. Judith
Gap has seen a dusting of wet snow already but surface temps have
stabilized. Cannot rule out a mix with wet snow into the evening
along the western foothills, but this should remain insignificant.
Current temps at Melville, Bozeman Pass and Red Lodge are in the
low 40s...but will continue to monitor.

Precip in the east will taper off this afternoon and in the west
this evening, after which we should see gradual clearing as we
transition to ridging and rising heights. A fairly moist boundary
layer and the light winds would suggest a risk of fog tonight over
much of the area...although latest HRRR runs have backed off on
this somewhat. Looking for low temps tonight in the mid 20s to
lower 30s, several degrees below current dewpts, so localized fog
is a good bet. Fog is a possibility again in southeast MT Thursday
night.

A period of dry and warm weather with max temps generally in the
50s will persist through the weekend, as we remain under a dry
zonal flow with above normal heights (next Pacific trof will also
dive to the SW CONUS). Expect breezy winds along the western
foothills this weekend, but cut off low to our south will keep
pressures in WY lower and thus don`t see a good gap scenario
setting up. By Sunday night or Monday, and perhaps into Monday
night, we should see an increase in pre-frontal winds ahead of a
stronger Canadian trof from the NW. Latest guidance is a bit less
windy during this time, but conceptually this is the time period
to watch. Current probabilities for 50+ mph gusts from Livingston
to Big Timber and Harlowton are 50-60%.

Good news for winter lovers. A Canadian cold front and likely the
coldest air yet of the fall will arrive by next Tuesday. However,
snowfall associated with this push of colder air is highly
uncertain, as the overwhelming consensus keeps the strongest upper
level forcing w/ the trof to our north (across AB/SK/northern
MT). Most ensembles are mostly dry in the Tuesday/Wednesday
period, though obviously this will need to be watched. For now,
look for highs in the 30s and lows in the teens, along with a
15-30% chance of light snow.

Any wintry weather next week will have obvious impacts on
Thanksgiving travel plans, so please monitor the forecast. Also,
it is looking more likely that another shortwave from the NW and
reinforcing cold air will bring much greater potential for
snowfall by the weekend.

JKL

.AVIATION...

Isolated rain showers will continue through the afternoon,
gradually ending in the evening. Expect occasional mountain
obscuration with the showers. Tonight into Thursday morning,
localized fog is possible (20% chance) near all TAF sites. Archer

&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 028/050 032/056 034/057 035/056 035/056 027/038 018/033
    10/U    00/U    00/B    00/B    02/W    32/J    11/B
LVM 028/052 029/054 030/054 033/054 035/054 023/037 015/034
    20/U    00/U    00/B    00/B    13/W    32/J    21/B
HDN 026/050 027/056 029/057 030/056 030/056 026/039 016/034
    00/U    00/U    00/B    01/B    02/W    32/J    22/J
MLS 026/047 027/052 030/055 032/054 030/053 025/035 015/031
    00/U    00/U    00/B    00/B    01/B    21/B    10/B
4BQ 027/050 029/054 031/055 032/055 032/055 026/037 017/030
    00/U    00/U    00/B    00/B    01/B    21/B    11/B
BHK 023/047 027/053 029/052 029/052 027/051 021/035 012/030
    00/U    00/U    00/B    00/B    01/B    21/N    11/B
SHR 026/051 027/055 027/057 028/056 028/058 020/037 012/031
    10/U    00/U    00/U    00/U    01/B    32/J    22/J

&&

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

&&

$$
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