HS reported by PCMR snow safety early morning on the 22nd during periods of high wind and snow. Other naturals noted in both South and West Monitor of somewhat similar size. Average depth was 1.5-2'....the 4'+ was not measured as it had pulled back up into the cornice.

Compression tests and Extended Column tests revealed a strong slab, but with high energy and poor structure. Full propagation, with a Q1 shear. Photo well illustrates how the spring-loaded slab failed right next to the adjacent bed surface...

Not convinced that a skier/boarder/snowmobiler could have triggered this avalanche. Collapsing noted on ridgeline above South Monitor, but where winds had scoured snow down to the crust and the crust was a bit thinner. Still, cool looking at surface hoar 'stalactites' underneath crust there at the collapse.