Shed 7 East, JFS Canyon 27 Dec

From: Ted Steiner

Date: 12/27/2012
Time: 1355
Location: Shed 7 East, JFS Canyon
Activity: Skiing

Snowpack Observations:
Ski toured up into the starting zone of Shed 7 East. Snow coverage excellent for ascent and descent.

Moderate west wind with strong gusts occurring above treeline, light winds at lower elevations. Sky cover- broken to mostly cloudy, air temperatures hovered around -7 C. Light snow fell for most of the day.

At treeline and above, west winds were transporting available snow from windward westerly aspects to leeward easterly aspects. This transported snow was being deposited as windslab on previously scoured east facing aspects and was very sensitive to triggering (Please view the attached video at: http://youtu.be/YMpsckDLBes).

We intentionally triggered a small soft slab avalanche and also observed the crown of a naturally released slab avalanche… Both of these slabs were small in size, occurred on easterly aspects above 5,600 feet elevation, and were comprised of new soft snow.

We classified the intentionally triggered slab during ski tests as SS-ASi- R1-D1-I (Soft slab-skier triggered intentional-very small, relative to the path- relatively harmless to people in size- new snow/old snow interface) and the natural avalanche as SS-N-R1-D1-I (soft slab-natural- very small, relative to the path- relatively harmless to people in size- new snow/old snow interface).

We did conduct a full profile at approximately 6,380 feet elevation in a relatively wind-protected area of the Shed 7 East starting zone. Profile is attached for reference.

12-27-2012-Shed-7-East