Storm slab avalanche on Tram ridge/ Shirley canyon

Location Name: 
Tram Ridge / Shirley canyon
Region: 
Cabin Creek, Deep Creek, or Pole Creek Area
Date and time of avalanche (best estimate if unknown): 
Thu, 01/19/2017 - 14:30
Location Map: 
United States
39° 11' 56.5332" N, 120° 15' 5.238" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Observation made by: Guide at Alpenglow Expeditions
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
38degrees
Trigger type: 
Skier
Crown Height: 
1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
50ft.
Terrain: 
Below Treeline
Elevation: 
7 200ft.
Bed Surface: 
Old Snow
Avalanche Length: 
100ft.
Number of similar avalanches: 
2
More detailed information about the avalanche: 

Sensitive storm slabs today. This particular slide was intentionally triggered by a ski cut on a steep rollover. Evidence of numerous natural storm slabs was also observed in similar terrain in this zone today. 

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: