Wind Loading on Hidden Peak

We could see blowing snow along all of the Sierra Crest while driving down to the West Shore. Once we arrived we could also see snow blowing around the lower elevation ridges before we started skinning up. On the skin up, strong winds were transporting snow at all elevations. In the lower elevations on open slopes typically considered sheltered terrain, a thin layer of wind-blown snow on the surface resulted in "punchy" snow conditions. In more sheltered areas at all elevations, soft snow still existed and handpits, ski cuts, and other observations did not reveal signs of instability. We also dug a full snowpit on a SE aspect to check for weaknesses around old crusts. Our pit data did not reveal signs of instability. 

In more exposed terrain near the summit of Hidden Peak, more intense wind-loading was occurring and firm 6 to 12+ inch deep wind slabs existed on leeward slopes. Aggressive ski cuts and kicks on these wind-loaded test slopes did not produce cracking or wind slab failures. We undercut one test slope and tried again. This attempt resulted in some minor cracking that only extended ~2 ft downslope from the skier to the track that undercut the slope. Handpits on these test slopes did show signs of instability. Cornices that had formed above the test slopes broke easily with ski kicks several feet away from the edge.

Photo 1: Strong winds were moving snow in below treeline areas.

Photo 2: Intense blowing snow and cornice formation near the summit of Hidden Peak.

Photo 3: Skier triggered cornice failure on a test slope did not produce signs of instability in the wind slab on the test slope.

Photo 4: Minor cracking down to the undercut part of the slope after repeated and aggressive ski kicks and jumps.