8" slab in N facing Couloir, Stevens Peak Area

Location Name: 
Stevens Peak Area
Region: 
Luther Pass Area (including Job and Freel)
Date and time of avalanche (best estimate if unknown): 
Sat, 02/18/2017 - 14:55
Location Map: 
United States
38° 44' 14.8344" N, 119° 58' 48.468" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
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: 
Storm Snow
Avalanche Width: 
50ft.
Terrain: 
Near Treeline
Elevation: 
9 000ft.
Avalanche Length: 
100ft.
More detailed information about the avalanche: 

8" slab broke in a smaller N facing couloir in the Stevens Peak area (~400ft couloir, likely un-named). Avalanche broke at skiers feet as traversing above slope, he was not carried with it.  Slid as a cohesive slab, 8" crown, 50ft wide X 100ft long with no solid bed surface.  Not a major avalanche but the terrain could of had consequences.  We had skied similar aspect earlier that was totally unreactive. Friends skied terrain 500ft to the west at the same time and also found it unreactive. Slope was wind loaded, top of the slope sluffed significantly but was not cohesive.

I have a video though can't post here off my phone.

Avalanche observation video: 

Soft Slab (~8") kicked off in a NW facing Couloir in the Stevens Peak area

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: 
North
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

8" new storm snow slid in a ~400ft couloir in the Stevens Peak area.  Slid as a cohesive slab, 50ft X 100ft long.