Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

Toured up toward the East Peak of Dana on the shoulder S of the V Bowl.

• High to extreme winds were blowing over the ridge of the East Peak form the SW.
• Wind speeds below 8200 ft were calm.
• Wind speeds above 8200 ft were light to moderate with the occasional localized stronger gust that blew massive amounts of fresh snow off the trees and created small whiteouts.
• Snow transport and active wind loading started picking up around noon  with increased elevation. Winds swirling from several different directions but mostly from the SW.
• The snow in sheltered trees on the lower moraine was soft and unconsolidated. In very steep places we were able to trigger small loose dry sloughs on our way down. Snow in more open treed ares and with increasing elevation became wind affected, forming a slab of about 50 cm. Hand shear tests pulled off with easy force in the snow that fell shortly after rain turned to snow.
• Dug a pit at 8980′ to see how deep down in the snowpack the rain penetrated. The snowpack was 173 cm deep with a 24 cm layer of moist DH at the bottom. It appears that the rain percolated down through the entire pre- storm snow pack.