Observation: White Pine

Persistent Weak Layer

Decreasing Danger

I toured up white pine to the spire below lake peak. Excellent powder skiing top to bottom with about 12 inches of new snow at the top. As I climbed the last slope to the spire I experienced a collapse under the slab from the previous storm and a fracture as long as my skis. At first it seemed to be a localized old wind slab, but as I continued to ascend I could still feel the weak layer under the slab. This was still a fairly protected area of the slope, and I was ascending towards the ridge which would have worse wind loading. At first I began to discount the instability as localized, but then decided I had observed new snow on a slab on a weak layer that collapsed and propagated under my weight and I was surrounded by avalanche terrain. I shot the slope to the col with my inclinometer at 27 degrees, and decided I could continue to the top safely. I changed my descent plans and took the most conservative route down. At the last pitch to the valley floor, which is quite steep, my intuition told me not to ski and I instead skinned up and traversed down canyon to a safer slope. On the traverse I remembered something Knox Williams told me in a class: You won't get tagged on a high danger day because you will observe the danger and not expose yourself. You won't get tagged on a low danger day because you can ski any line without incident. You are more likely to get tagged on the in between day, when you observe some subtle concerns, but it still seems OK. Today felt like that in between day to me.