Observer Name
Travis England
Observation Date
Sunday, December 6, 2015
Avalanche Date
Sunday, December 6, 2015
Region
Salt Lake » Big Cottonwood Canyon » Days Fork » Upper Days
Location Name or Route
Upper Days Fork
Elevation
10,000'
Aspect
Northeast
Slope Angle
30°
Trigger
Skier
Avalanche Type
Soft Slab
Avalanche Problem
Wind Drifted Snow
Weak Layer
New Snow/Old Snow Interface
Depth
8"
Width
20'
Vertical
250'
Comments
Westerly winds were stronger than expected (20+ MPH gusts?), and the windslabs on the E-NE slopes were very obvious. We carefully ski cut the slope, and got the ~1" wind crust to move but with very little propagation. A few careful turns later, I felt a layer ~6" underneath the surface buckle and start to move. Easy to ski out of, but eventually the slide entrained enough snow to easily move a person.
Investigating the slide path, it was easy to see places where the slide stepped down into the old snow. We didn't do a formal analysis of the layers involved.
Takeaways are that wind has definitely been moving snow and forming slabs, be extra vigilant around ridges or any steeper slope affected by the wind, and be very concerned when new snow comes.
Picture below shows the top ~100 feet of the path. Note the obvious points where the slide stepped down into deeper layers.
Coordinates