Folks triggered both small and large slides remotely on Sunday (12/20) in the Jack Creek Preserve area near Fan Mountain of the northern Madison Range. Photo: C. Ebeling
15-16
GNFAC Avalanche Advisory for Tue Dec 22, 2015
Snowpack and Avalanche Discussion
Southern Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone Cooke City
Snowmobilers near Fan Mountain in the northern Madison Range remotely triggered this slide while riding on the rode. Remotely triggered avalanches are clear indication of very unstable conditions. Photo: C. Ebeling
This snowpit is very represenitve of the snowpack structure that caused the avalanche fatality on Sheep Mountain.
GNFAC Avalanche Forecast for Mon Dec 21, 2015
Snowpack and Avalanche Discussion
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
This large silde occurred on the Football Field just south of the Bridger Bowl. The crown was a few hundred feet wide and up to four feet deep. The avalanche failed on facets near the ground. Photo: B. Bowl Ski Patrol
The avalanche broke on depth hoar 3-4 feet deep and 100 feet wide on the SE end of Sheep Mountain. It struck three snowmobilers low on the slope. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Mon Dec 21, 2015
This avalanche was triggered from low on the slope, not far from where Alex was standing. One person was partially buried, and two fully buried with one death. The hole was where one of the sleds was extricated. The crown was estimated to be 400 vertical feet above the toe with an alpha angle of 28 degrees.Photo: GNFAC