Frisby Falling

Size 2 slab avalanche triggered accidentally by snowmobiler without his knowledge. Slope angle approx 35° Propagated behind him and he made it over the top.

Snowmobiler riding along the top edge of hill triggered a size 2 slab avalanche. It propagated across behind him so he was not even aware he triggered. I was standing down at the bottom and witnessed the avalanche. One other rider in our group had already got to the top via a straight up route with no signs of instability. The triggered slide had a crown of approx 18” depth average. The could have easily propagated further and that would have resulted in a much larger slide.