Observation: Public

Observation Details

Signs of Unstable Snow

Observations

Snow levels had lowered to 3500-4000ft after a period of heavy rain well into the alpine Friday. The saturated snowpack was covered by about 1ft of new snow by 2pm Saturday in areas near and above treeline. Below, the rain really did some damage, and the snow line had bumped up to about 3000ft.

Our small riding group chose simple, low-angle terrain, and minimized our exposure to overhead hazard. Strong and sustained winds (southerly, gusting 40mph+) along with heavy snowfall (S2) and rain made for challenging visibility. Observations above treeline were limited. Above 4500ft, we found shallow layers within new and wind drifted snow to be reactive in hand pits and on small test slopes (photo 1). Stability tests targeting deeper layers produced resistant planar fractures and no propagation. Dry, lower-density snow was found above 5000ft along with significant wind loading and cornice development. Between 4000-5000ft, the new snow was heavy and moist. The 01/02 rain layer and mid-snowpack were wet and much less supportive below 5000ft.