Large Remotely Triggered Avalanche

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/29/2021

Zone: Northwest Mountains
Location: Purple Ridge
Aspect: East
Elevation: 11,600ft

Avalanches: Remotely triggered a large avalanche from a lower angled slope, connected to a steeper slope. After no signs to instability all day, finally found just the right spot to punch through the slab, into the weak layer, and get a collapse. No shooting cracks in the terrain where the collapse occurred, but within a few seconds the larger bowl started to avalanche. The avalanche ran on the slower side, no powder cloud. It was large in size and propagated widely. This slope has avalanche previously this season. The crown is estimated to have averaged about 40 to 45 cm, while the deepest part of the crown where it broke into a cornice was closer to 110 cm.

Weather: Mostly cloudy to overcast sky. Warm temps. Alpine winds picking up in the afternoon and transporting snow.

Snowpack: No other signs to instability. A few roller balls on steep S and SW aspects at lower elevations.