Avalanche on Elephants Back

Location Name: 
Elephants Back
Region: 
Carson Pass Area
Date and time of avalanche (best estimate if unknown): 
Sat, 12/10/2016 - 17:00
Location Map: 
United States
38° 40' 46.2756" N, 119° 58' 55.6284" 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
Obvious avalanche path
Terrain Trap
Observation made by: Professional Observer
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
43degrees
Trigger type: 
Natural
Crown Height: 
4 ft
Aspect: 
Northeast
Weak Layer: 
Old Snow
Avalanche Width: 
400ft.
Terrain: 
Above Treeline
Elevation: 
9 500ft.
Bed Surface: 
Ground
Avalanche Length: 
700ft.
More detailed information about the avalanche: 

Natural avalanche in the bowl at Elephants Back that likely ran some time on 12/10/16 during the storm. Snow line in this area appeared to be around 9000 feet. Undisturbed surface snow above this elevation was soft and smooth, with a firm rain crust below. The crown ran accross most of the bowl. Slope angle where I measured (near photo 5) was 43 degrees. I estimate the width at approximately 400 feet and the length at approximately 700 feet. The crown featured several step down features. It likely started in new wind slab then stepped down into older snow and ultimately broke at the ground snow interface on basal facets. The terrain near the north of the bowl has a bench feature 200-300 feet below the headwall and the debris stopped here at the northern flank of the slide. In the middle and southern edge the debris ran full path. 

Avalanche Photos: 
Avalanche observation video: 

IMG 0724

Weather Observations
Air temperature: 
Precipitation: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: