Newly buried surface hoar and loose dry instability on Silver Peak.

Buried surface hoar and skier triggered loose dry instability was observed in this area. Surface hoar 5-15 mm in grain size was buried under new snow and is now labeled as the 12/4 SH layer.  This weak layer was buried under 3-5 inches of new snow which was not a sufficient new snow load to create instability. Where this weak layer failed, it did so as small skier triggered loose dry avalanches. This matched well with snowpit tests (PST) that showed non-propagating slab fracture results when testing the weak layer and overlying slab..

Today there was still an opportunity to travel in avalanche terrain in this area without triggered slab avalanches. If this buried surface hoar layer continues to persist under future loading events, widespread slab avalanche activity will be expected. Continued monitoring of this weak layer will be critical.