Observation: Public

Observation Details

Signs of Unstable Snow

Observations

We skinned from paradise to 8500 feet along the Muir route, then skied the route back to Alta Vista, down the east face of Alta Vista into the Edith creek basin, then up along the Golden Gate trail and back over toward the Skyline trail for a second lap on Panorama face. Above Panorama point (and especially past McClure Rock) was wind scoured and very icy, with pockets of wind distributed snow; most people used crampons past this point. Weather was sunny, but gusty winds to estimated 40-50 mph kept the snow cold and frozen above Panorama point. On the East face of Alta Vista, we found 5 cm of wind slab on top of a few cm of 4F-1F snow, which lied on top of the recent rain crust. In a few hand shear tests on the east face of alta vista (5900'), we were variably able to elicit partial shears of the upper 5 cm wind slab. Wind distribution occurred in the Edith creek basin, evidenced by blowing snow and textured snow surfaces; see photo and video.