Avalanche: NW Couloir

Observer Name
Dan B. Carolyn L. Luke B.
Observation Date
Sunday, January 15, 2017
Avalanche Date
Sunday, January 15, 2017
Region
Provo » Box Elder » NW Couloir
Location Name or Route
Box Elder Peak NW Couloir
Elevation
10,200'
Aspect
North
Slope Angle
40°
Trigger
Skier
Trigger: additional info
Unintentionally Triggered
Avalanche Type
Hard Slab
Avalanche Problem
Wind Drifted Snow
Weak Layer
Facets
Depth
3'
Width
80'
Vertical
300'
Caught
1
Carried
1
Snow Profile Comments
Snow was layered but not reactive. Some wind features observed on the snow surface when looking from the ridge. From the summit to mid slope 6 inches of soft cold snow on a firm base. Snow became more wind effected mid slope and a bit punchy. Where the slide occurred a dense wind slab was resting on pre storm facets.
Comments
My partners and I were on the summit around 1:30. Temperatures were cool the sun was bright and there was no wind at all. We decided to ski the NW Couloir after evaluating stability on the way up. We could see The snow in the cirque had been slightly wind effected. We felt the most problematic area on descent would be the chutes at mid slope. After skiing the top 1000' we reconvened atop the chutes. The skiing was Sublime to this point and the snow was not sluffing and felt stable. The quality and stability to this point lowered my guard. My bright idea was to straight line the chute to stay away from the thin spots and stay light. As soon as I started a turn the slope spider webbed and the slab picked up speed. I tried to ski off the slab but eventually I was knocked off my skis but was able to dig the edges into the bed surface and arrest. The slide ran quite a distance below me. A very humbling experience and one to learn from.