Corn & Cornices in Johnson Canyon

Sunny, fun, near-corn conditions in Johnson Canyon mid-day today. Looking around Donner summit it seemed like almost everything that could slide has slid in the past few days, with large avalanches  visible on Trestle, Heart Chute, Frog Lake cliffs, etc.

In Johnson Canyon, very large cornice chunks (up to van sized) had broken onto the east slope that often loads (see pic 1 and video). In one section the cornice fall triggered a D2 avalanche.

While most of the cornices had already broken off, one concern is that large pieces of hangfire remain, including some sections that are creeping and created open cracks (see pic 2 and video). If the cornices survive to Sunday and new snow bridges the cracks it could be hard to tell where you might break through and trigger a surprisingly large cornice.