Crown Profile of the Skier Triggered Avalanche for Virginia Lakes Yesterday

SNOWPACK OBSERVATION
Frog Pass
Submission Info
Forecaster
Monday, January 29, 2018 - 10:45am
Red Flags: 
Recent avalanche activity
Rapid warming
38° 3' 1.08" N, 119° 17' 25.8" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up the Virginia Lakes basin to study the avalanche triggered around noon yesterday. Very warm, mostly calm day. Started to feel light SW wind above 10,900', no blowing snow. Stomped on small previously wind loaded rolls along the same ridgeline as the avalanche and these test slopes had mixed results: all cracked easily, and some failed and slid down the hill. Cracking was about 10cm deep within previously (20180127?) deposited wind slabs. The snow that broke and slid down the hill was becoming moist and heavy, snow underneath was dry.

The starting zone for this avalanche was very steep, almost 50 degrees. See attached crown profile for notes about the slide. Profile was dug ~2m from the actual crown so the slab is slightly deeper in the profile than it was in the actual slide.

No other visible avalanches, only small rollerballs on southerly slopes.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Crown
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
None

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