NOAA has issued Winter Storm Watches for Wyoming and Montana for Sunday that are calling for 6-12″ of snow at Big Sky MT and 10-24″ of snow at Jackson Hole WY & Grand Targhee WY.

• Grand Targhee has a 63″ snowpack and they’ve seen 136″ of snowfall this year – open top to bottom.
• Jackson Hole has a 24-48″ snowpack and they’ve seen 130″ of snowfall this year.
• Big Sky has a 26-39″ snowpack.

video of November at Grand Targhee

WYOMING STORM DETAILS:

NOAA just upgraded the storm headed to Wyoming in both snow forecast and advisory level.

At 1:39pm MST today, NOAA issued a Winter Storm Warning (up from a Winter Storm Watch) and is now forecasting 10-24″ of snow (up from 6-14″ previously forecast).

Total snow accumulations of 10 to 15 inches, with localized amounts up to 
24 inches, are expected. - NOAA Riverton, WY today

Grand Targhee and Jackson Hole ski resorts are under this Winter Storm Warning and are both forecast to see 10-24″ of snowfall tomorrow.

MONTANA STORM DETAILS:

Heavy snow possible. Plan on difficult travel conditions for areas south of I-90. 
Total snow accumulations of 4 to 7 inches at lower elevations and 6 to 12 inches 
in the mountains are possible. - NOAA Great Falls, MT

Winter Storm Warning for Wyoming:

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
139 PM MST Sat Dec 2 2017

...Winter storm for mountains of Western Wyoming tonight through
Sunday night...

Winter storm watch for parts of Central Wyoming Sunday night and
Monday Morning...

.Snow will spread south and east from the northwest mountains
this evening. Snow, possibly heavy at times, will continue Sunday
and into Sunday night over the western mountains. The snow will
be accompanied by periods of gusty wind. Areas of blowing and
drifting snow will likely develop. Heavy snow will also be
possible from Eastern Sweetwater County to Casper Mountain Sunday
night through Monday morning.

Teton and Gros Ventre Mountains-
139 PM MST Sat Dec 2 2017

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 5 AM
MST MONDAY...

* WHAT...Heavy snow and blowing snow expected. Plan on difficult
  travel conditions. Total snow accumulations of 10 to 15 inches,
  with localized amounts up to 24 inches, are expected.

* WHERE...Teton and Gros Ventre Mountains.

* WHEN...Midnight to 5 AM Monday.

* ADDITIONAL DETAILS...Winds gusting as high as 35 mph will
  cause patchy blowing and drifting snow.  Travel may become
  difficult over Teton and Togwotee passes.

Winter Storm Warning for Montana:

URGENT - WINTER WEATHER MESSAGE
National Weather Service Great Falls MT
815 AM MST Sat Dec 2 2017
Madison-Gallatin-
Including the following locations Ennis, Norris Hill,
Raynolds Pass, Twin Bridges, Virginia City, Bozeman,
West Yellowstone, Battle Ridge Pass, Bozeman Pass,
and Targhee Pass

...WINTER STORM WATCH IN EFFECT
FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT...

* WHAT...Heavy snow possible. Plan on difficult travel conditions
  for areas south of I-90. Total snow accumulations of 4 to 7
  inches at lower elevations and 6 to 12 inches in the mountains
  are possible.

* WHERE...Madison and Gallatin counties.

* WHEN...From Sunday morning through late Sunday night.

* ADDITIONAL DETAILS...Significant reductions in visibility are
  possible. Poor traveling conditions are possible Sunday
  afternoon and night.