Test slope failure on the Far East Ridge of Tamarack Peak

Submitted by andy on Mon, 03/08/2010 - 4:32pm
Location Name: 
Far East Ridge of Tamarack Peak
Region: 
Mount Rose Area

Location

United States
39° 18' 47.4588" N, 119° 54' 18.7704" W
See map: Google Maps
Position: 
Forecaster
Date and time of avalanche (best estimate if unknown): 
Mon, 03/08/2010 - 1:15pm
Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Obvious avalanche path
Avalanche Observations
Avalanche Type: 
Dry
Avalanche Type: 
Slab
Trigger type: 
Skier
Slope: 
38degrees
Aspect: 
North
Elevation: 
9080ft.
Bed Surface: 
Old Snow
Weak Layer: 
Storm Snow
Crown Height: 
1 ft
Avalanche Width: 
100ft.
Avalanche Length: 
30ft.
Terrain: 
Near Treeline
Avalanche Photos: 
Avalanche observation video: 
More detailed information about the avalanche: 

Winds started to build stiff wind slabs on wind-loaded slopes last night. In this area these harder (4f+) wind slabs sat on top of a softer (4f-) layer of recent snow. I was able to break this interface with one hard kick from the ridgeline (see video for location). The slide that resulted was about 100 ft wide and ran downslope about 60 ft at the farthest. In most areas it ran down slope only about 30 ft. Shooting cracks occurred on the lower angle part of the ridge steps before triggering the slide (photo above). Wind slabs like this should become larger and more widespread as more snow and wind continue to load the leeward slopes.

Weather Observations
Blowing Snow: 
Yes
Wind Speed: 
Strong
Wind Direction: 
Southwest
Air temperature: 
Below Freezing
Air temperature trend: 
Cooling
Precipitation: 
Snow
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: