Observation: Turnagain

December 18, 2014
Approximate time 14:00

Skier triggered avalanche on Sunburst Southwest face. One caught and fully buried, no injuries.
SS/HS-ASu-D2.5-R3-I

Trigger – Skier
Aspect – SW
Elevation, Start Zone ≈ 3600′

Estimated Dimensions:
Crown Depth ≈ 2 – 3′
Width ≈ 300′
Vertical runout ≈ 1000′ (The toe of the debris was reported to have stopped short of the creek drainage.)
Suspected weak layer – Buried Surface Hoar

Reported events:
CNFAIC staff were able to talk with the two skiers involved in the above avalanche. Skier 1 safely skied the SW face of Sunburst to the valley floor without triggering a slide. Skier 2 triggered the avalanche and was fully buried with a good air pocket and his hand sticking out of the snow. He was able to start excavating himself with his free hand. Skier 2 was out of the way of the debris and was able to get to the buried skier to assist digging him out. No one was injured.

Weather:
Temps in the low 20’s F
Winds calm
Clear skies, no precipitation

Snowpack history:
This was the first clear day after a four day storm (12/14 – 12/17) deposited 24″ – 30+” of new snow in the Turnagain Pass zone. The storm snow is sitting on a layer of buried surface hoar (0.2 – 2cm in size) which sits on top of a melt-freeze crust at elevations from 3000′ and below. See CNFAIC observations from the past week for additional snowpack history at this time.