Deep Slab on Andesite Ridge

Location Name: 
Andesite Ridge
Region: 
Donner Summit Area
Date and time of avalanche (best estimate if unknown): 
Wed, 01/04/2017 - 15:00
Location Map: 
United States
39° 21' 22.4748" N, 120° 21' 54.612" 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
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
33degrees
Trigger type: 
Natural
Crown Height: 
4 ft
Aspect: 
East
Weak Layer: 
Old Snow
Avalanche Width: 
100ft.
Terrain: 
Near Treeline
Elevation: 
7 960ft.
Bed Surface: 
Old Snow
Avalanche Length: 
200ft.
Number of similar avalanches: 
3
More detailed information about the avalanche: 

This avalanche likely occurred on Wed. 1/4. Snowpack observations near where the photo was taken revealed the facets above the 12/15 rain crust to be the likely failure layer. The slope angle of this slide ranged from 32-33 degrees near the top to 37-39 degrees in the steeper parts of the slope.

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