Natural Avalanche Cycle at Lionhead

Natural Avalanche Cycle at Lionhead


We rode into Lionhead Ridge to pull the weather station for the season. There was a large natural avalanche that broke yesterday on Bald Peak it was bounded laterally by the terrain, so it only broke a couple of hundred feet across, but it appeared to be 4-6' deep and ran the full available vertical into the creek below. This avalanche was the key piece of information for the day and answered the question of whether or not the snowpack is continuing to produce deep slab avalanches with every storm, it is. 

After dealing with the weather station, we rode around to Denny Creek and up under LH Ridge. We saw three more avalanches that broke at least a few feet deep and several storm slab avalanches that failed within the new and wind-drifted snow. No other observed avalanches were as large as the one on Bald Peak. 

We stayed in terrain less than 30 degrees steep, with minor exceptions on small slopes. We avoided all large, wind-loaded slopes and crossed below them cautiously. The snowpack maintains the characteristics of mid-winter, and deeply buried persistent weak layers remain a concern. Going forward, we will continue to assess the upper few feet of the snowpack for instability before considering any steep slopes. We will continue to manage the deep slab avalanche problem through avoidance (of avalanche terrain) and consequence minimization (by selecting non-wind-loaded slopes that are smaller and free of terrain traps). 

Lionhead Range
Location (from list)
Observer Name
Dave Zinn