Northern Madison

From obs.: "Saw a recent cornice triggered wind slab off of Hardscrabble Peak, crown looked fairly fresh. There was a second crown line below the rock band. Conditions were very windy, with snow still being transported. Most snow surfaces were wind affected, but saw no cracking or collapsing." Photo: F. Miller

Sooooo many pin wheels coming down in the Gallatin canyon today on my way home from work. I was driving and couldn't get a full look, but half way through the canyon, it looked like a whole, relatively small, slope slid, maybe propagated 50-75ft on the west facing side of the road.

2/17 Immediately noticed signs of wind loading and wind slabs on NE-E aspects once in the basin. New cornices have formed in the last couple days along the North ridge to the summit. Cornice collapse on the summit triggered a small wind slab on an isolated slope. 

Cracking in the new and wind-drifted snow on the Ridge of Middle Basin. These resulted in a narrow avalanche that ran quite far. 

Cohesive wind slabs roughly 1 foot deep were triggered between middle peak and the going home chute on the northeast aspect. Upon skiers weight shooting cracks traveled roughly 100 feet to trigger a small avalanche. The size was small as only the top 50 feet of the slope slid but the snow from the avalanche carried down the entire face.

Photo: GNFAC