Remote Triggered Avalanches on Andesite

Location Name: 
Andesite Peak
Region: 
Donner Summit Area
Date and time of avalanche (best estimate if unknown): 
Wed, 01/13/2016 - 11:00
Location Map: 
United States
39° 21' 4.338" N, 120° 21' 59.1624" 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: 
Dry
Slab
Slope: 
38degrees
Trigger type: 
Skier
Crown Height: 
2 ft
Aspect: 
Northeast
Weak Layer: 
Old Snow
Terrain: 
Above Treeline
Elevation: 
8 100ft.
Bed Surface: 
Old Snow
Number of similar avalanches: 
3
More detailed information about the avalanche: 

3 separate avalanches near Andesite Peak.  All were in open above treeline terrain with active wind loading occurring.  Aspects were NE-E with start zones above 35 degrees.  2 of the slides were remotely triggered-1 from the corniced ridge above and 1 from below slope and 50' away.  The other avalanche off of Andesite Peak was triggered with an intentional cornice drop on the slope.  All avalanches had crown lines up to 2-3' deep.

Photos 1-3:  Slide #1.  Remotely triggered from below and 50' away.  Long shooting cracks associated with remote triggering.  Photo 3 shows small step down to lower layer.

Photos 4-5:  Slide #2 off of Andesite Peak triggered by cornice drop.

Photo 6: Slide #3.  Remotely triggered from corniced ridge.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Gale Force
Precipitation: 
Snow
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
Greater than 1 in. per hour