Storm snow from the Dec 8-9 storm totaled around 8 inches in the area. Wind effect and transport from northwesterly winds on the night of December 10 was evident, particularly above about 11,500 feet. On north and east-facing terrain the new snow buried reactive near-surface facets, which looks like it will be our next generation of Persistent Slab avalanche concerns. There were several large collapses, shooting cracks, and a couple small avalanches breaking at the new-snow old snow interface.

Mt Daly and Silver Creek area

Observed three more recent avalanches all breaking just under the recent storm snow. One natural avalanche broke on a northeast-facing slope around 10,500 feet on on old bed surface from avalanche activity during the Thanksgiving storm. This is notable because it suggests that areas that previously avalanched can no longer be considered go-to safe terrain in areas that picked more than about a foot of recent drifted snow. Another natural avalanche consisted of wind-drifted snow on an east-facing slope around 12,000 feet. Lastly, a skier triggered a small slab on a steep east-facing roll over around 11,800 feet.

Small isolated wind-drifted slabs posed little concern on southerly slopes. Storm snow was settling and was difficult to get to move on the underlying supportive crusts except in very steep terrain where we could produce minor slow-moving sluffs. On northerly and east-facing slopes the new snow persevered near-surface facets. Even on previously avalanched bed surfaces, this interface is reactive and worrisome where the drifted slabs are more than about a foot deep. North-facing terrain, especially below treeline is mostly facets top to bottom and capable of producing facet sluff is continuously steep terrain.

Cold start to the day, but warmed quickly under sunny skies with only light northerly winds at ridgetop.