Cornice Drop R1D1 Frog Lake Ridge

Location Name: 
Frog Lake Ridge
Region: 
Carson Pass Area
Date and time of avalanche (best estimate if unknown): 
Thu, 03/03/2011 - 12:00
Location Map: 
United States
38° 41' 24.54" N, 119° 59' 9.528" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Professional Observer
Avalanche Observations
Avalanche Type: 
dry,slab,
Slope: 
45degrees
Trigger type: 
Other - explain below
Crown Height: 
1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
60ft.
Terrain: 
Near Treeline
Elevation: 
8 770ft.
Bed Surface: 
Old Snow
Avalanche Length: 
250ft.
More detailed information about the avalanche: 

Small slab triggered by intentional cornice drop ~3 hours before crown profile recorded. Mitt pits and probing showed similar layering elsewhere, but no other signs of instability observed. Clear visibility of surrounding peaks with no further evidence of recent avalanche activity.

pic 1: Crown at it's deepest was 45cm

pic 2: ECTP results - hard to initiate, but likely to propagate. Column fell off cleanly during 2 tests, and failed to propagate on a 3rd.

Snowpit or crown profile photo or graph: 
Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Evidence of previous wind transport, but current wind transport remained light