Avalanche from Last Storm Cycle: Pretty big.

Location Name: 
North side of ridge above Cup Lake, Ralston-Echo Area
Region: 
Echo Summit Area
Date and time of avalanche (best estimate if unknown): 
Thu, 12/27/2012 - 00:00
Location Map: 
United States
38° 49' 49.3716" N, 120° 5' 18.7764" W
See map: Google Maps
US


Red Flags: 
Observation made by: Public
Avalanche Observations
Avalanche Type: 
slab,
Slope: 
40degrees
Trigger type: 
Natural
Crown Height: 
6 ft
Aspect: 
North
Weak Layer: 
Storm Snow
Avalanche Width: 
1 000ft.
Terrain: 
Above Treeline
Elevation: 
9 000ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
2 000ft.
More detailed information about the avalanche: 

We skiied up the south face of the Ralston Ridge frm HWY 50.  We topped out and saw the remains of a very large slab avalance on the north side of the ridge.  This is one of the biggest avalanche lines I've ever seen in the Sierra.  We dug about 8 feet down on a similar north facing line we wanted to ski up the ridge.  Basic column test showed a layer about 4 feet down and then another 3 ft down but I had to pry hell-a-hard to get the column to go.  Bonding looked typical Sierra bomber despite the layers.  We skiied good windpack and then some good powder down low.  But that avalanche path was freaky big.  Looks like it started from the convex roll-away and pulled it away from the crest.

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