Natural avalanche on Silver Peak from March 1st.

Location Name: 
Silver Peak
Region: 
Cabin Creek, Deep Creek, or Pole Creek Area
Date and time of avalanche (best estimate if unknown): 
Thu, 03/01/2012 - 12:00
Location Map: 
United States
39° 13' 27.8688" N, 120° 14' 30.6312" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
dry,slab,
Slope: 
37degrees
Trigger type: 
Natural
Crown Height: 
2 ft
Aspect: 
North
Weak Layer: 
Old Snow
Avalanche Width: 
100ft.
Terrain: 
Near Treeline
Elevation: 
7 750ft.
Bed Surface: 
Old Snow
Avalanche Length: 
200ft.
More detailed information about the avalanche: 

This natural avalanche most likely failed on March 1. Remains of significant en echelon cracking existed in the upper portion of the slope in lower angle terrain. Note the crown (indicated by red arrow in photo 1) low on the slope below the convexity in 37 degree near treeline terrain. Investigation on March 3 indicated that the snowpack failed on the persistent weak layer of crusts and facets just below the recent storm snow.

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: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Wx obs listed above are for March 1, the day when the avalanche most likely occurred.