We found lots of thin snow at Lionhead with a layer of weak facets near the ground. These facets consistently propagated fractures with scores ranging from ECTP10 to ECTP24. No avalanches on this layer were seen, but riders can definitely trigger an avalanche on this layer if they hit a weak spot in the snowpack. Photo: GNFAC
14-15
Forecast link: GNFAC Avalanche Advisory for Tue Jan 13, 2015
GNFAC Avalanche Forecast for Fri Jan 9, 2015
Snowpack and Avalanche Discussion
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone Cooke City
GNFAC Avalanche Forecast for Thu Jan 8, 2015
Snowpack and Avalanche Discussion
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone Cooke City
The odds of triggering an avalanche have dropped since just two days ago when heavy snowfall spiked the avalanche danger. The snowpack was not producing many avalanches prior to this storm and did not produce as many avalanches as we expected following the storm.
GNFAC Avalanche Advisory for Wed Jan 7, 2015
Snowpack and Avalanche Discussion
Bridger Range Gallatin Range Madison Range Lionhead area near West Yellowstone Cooke City
This pit showed us that weakest layer in the snowpack was facets 65 cm from the surface. This layer propagated consistently in our stability tests. Photo: GNFAC
This avalanche likely released on Monday during the avalanche warning. It is located in Republic Creek south of Cooke City on a W-NW facing slope around 9,000', and estimated to be about 2' deep and 40' wide. Photo: B. Fredlund