Observations from Schallenberger Ridge - Site of the skier triggered avalanche on March 10.

Location Name: 
Schallenberger Ridge
Region: 
Donner Summit Area
Date and time of observation: 
Wed, 03/13/2013 - 11:25
Location Map: 
United States
39° 18' 20.952" N, 120° 16' 51.6" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Obvious avalanche path
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Observations at the site of the skier triggered avalanche that occurred on March 10 indicate a couple small differences from the original information reported by the triggering party. This was a persistent slab avalanche, failing on near crust facets and the slope angle of the bed surface was 38 degrees. All other information from the reporting party seemed very accurate.

Warm air temperatures Monday and Tuesday had changed the upper snowpack at this low to mid elevation area at 7,230'. The facets are now moist, capable of producing a snowball. They were no longer reactive in snowpit tests. Formal propagation tests (ECT & PST) performed adjacent to the avalanche indicated that propagation is now unlikely upon weak layer collapse.

Wet surface snow was noted on all aspects in this area up to the top of the ridge at 7,460'. Skier triggered roller balls up to 1 foot in diameter were prevalent on shaded N aspects between 6,000' and 7,000' in the noon to 1pm time frame.

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

20130313 Schallenberger Ridge

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: 

Thin high level clouds.