Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Bottom Line

Today we rode sleds into the west side of the Swans near Sunday Mountain and Clearwater lake. Nearly every avalanche path in the Swans had evidence of past wet slides from the last few days.
It did freeze in the Seeley area last night. The snowpack had very little cohesion by midday. For example, the skis on my sled were starting to punch through the surface on the groomed trail.
While investigating a large D2+ slide that had occurred naturally early in the day around lunchtime, we witnessed two wet slabs simultaneously start from just north of Sunday Mountain. Both slides funneled and converged together, and we could hear trees breaking as they moved down the path. This slide could have easily destroyed a single-family (D3). The estimated slide path length was one mile long, 2400ft of vertical fall, and 600ft wide at the debris pile. We believe the trigger was a point realise from a cliff band near the summit that then stepped down to rock and ground.