Snowpit and extensive snowpack collapse on the far east ridge of Tamarack Peak

Location Name: 
Far East Ridge of Tamarack Peak
Region: 
Mount Rose Area
Date and time of observation: 
Sun, 12/13/2009 - 10:30
Location Map: 
United States
39° 18' 49.0752" N, 119° 54' 20.8116" 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
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Snowpack collapse resulting from digging the pit propagated across an area about 300ft upslope by 500ft across the slope. The slope fractured but did not slide due to it being only 27-29 degrees. Another simmilar collapse was triggered by a skier on a nearby slope. Photos 4 and 5. This collapse was triggered when the skier stepped onto a shallow area in the snowpack near a tree. Photo 6 and the red lines on the overview photo. . It propagated across a similarly large area. The failure layer on both of these slopes was the Oct/ 19th facet layer. Both slopes were below treeline between 8800' and 9000', north facing and between 26 and 29 degrees in steepness.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Snowpit videos (tests, etc): 

rMVI_0009.AVI

Any other comments about the observation or links to outside pages that have more info on the observation: 

 

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: