Natural Persistent Slab Avalanche on Elephants Hump

Location Name: 
Elephants Hump
Region: 
Carson Pass Area
Date and time of avalanche (best estimate if unknown): 
Tue, 01/09/2018 - 02:00
Location Map: 
United States
38° 41' 30.804" N, 119° 58' 6.528" 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: Forecaster
Avalanche Observations
Avalanche Type: 
Wet
Slab
Slope: 
35degrees
Trigger type: 
Natural
Crown Height: 
1 ft
Aspect: 
North
Weak Layer: 
Old Snow
Avalanche Width: 
250ft.
Terrain: 
Near Treeline
Elevation: 
8 400ft.
Avalanche Length: 
100ft.
More detailed information about the avalanche: 

Natural persistent slab avalanche observed on Elephants Hump.  This avalanche had 2 inches of new snow on top of the bed surface and debris and was thought to have occurred in the early morning hours, 2-3am.  Aspect was north, 010*-027*, at 8400', with a slope angle ranging from 34-36 degrees.  This avalanche had wet slab characteristics with the slab and facet layer both moist to wet.  A combination of rain and snow occurred at this elevation during the storm and through today.  The avalanche failed mid slope which was less steep than the upper slope.  The upper slope was thought to have been wind scoured by NE winds in December which removed or changed the weak layer structure.  

Widespread cracking, collapsing, and whumping on similiar aspects throughout this area-see Elephants Hump snowpack observation from today.

Avalanche Photos: