Avalanche on Castle Peak

Location Name: 
North Bowl Castle Peak
Region: 
Donner Summit Area
Date and time of avalanche (best estimate if unknown): 
Thu, 03/02/2017 - 13:20
Location Map: 
United States
39° 21' 52.1892" N, 120° 20' 44.0484" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Obvious avalanche path
Terrain Trap
Observation made by: Public
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
40degrees
Trigger type: 
Skier
Crown Height: 
Less than 1 ft
Aspect: 
North
Weak Layer: 
Unknown
Avalanche Width: 
150ft.
Terrain: 
Near Treeline
Elevation: 
8 400ft.
Bed Surface: 
Old Snow
Avalanche Length: 
100ft.
Number of people caught: 
1
Number of partial burials: 
1
More detailed information about the avalanche: 

Our group of three decided to ski the north bowl of Castle Peak today. Upon arriving at the ridge, we found cold, dry snow on the north aspect. We observed numerous ski and snowmobile tracks, and limited smaller slab releases which appeared to be 24+ hours old. We cut some chunks of cornice onto the slope below us, and observed no instabilities. Combined with recent observations, we decided to ski the slope. 

Approximately halfway down the slope, I skied over a rollover, and two turns past the crest of it I released a ~6" slab. I was carried less than 100 feet, and was buried waist deep. I was able to free myself, and ski away with no injuries. 

Notes from a forecaster visit on 3/3: It looks like this slope was previously undercut by other tracks (snowmobile and skier) and that made this convex rollover into an unsupported slope on a convex rollover. The area was slightly wind affected and a soft wind slab existed on the surface. Snowpit work and observations from the area on 3/3 can be found here.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None