Sherwins - Sensitive avalanche conditions - multiple intentional skier triggered avalanches

SNOWPACK OBSERVATION
Sherwins
Submission Info
Forecaster
Saturday, March 2, 2019 - 1:30pm
Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
37° 36' 44.7012" N, 118° 59' 31.4376" W
Snowpit Observations
More detailed information about the snowpack: 

 

Toured up past Mammoth Rock carefully staying close to ridge where wind was keeping new snow in shallow deposits.  Thanks to whoever skillfully put in the skintrack I followed to minimize exposure.  Important to note that this route is often times NOT ok depending on how wind is loading snow.  

Intentionally triggered avalanche in Poop Chute next to Mammoth Rock (8800', E aspect, 45degree slope), ~50' across, 8-12" crown.  See attached video after the slide of cracking and more failures above initial crown.  Carefully stomped on some cornices at the top of the ridge, resulting in a large wide avalanche, see seperate avalanche observation observation.  

Upside-down new snow.  Less dense under more dense.  Hand shears failed upon isolation or with easy force on the way up in areas with wind deposit.  See attached video.  

Pit dug in sheltered area ~9600', NE aspect.  ECTPV12cm down in density change within fist hard new snow with overlying 4Finger hard 6cm thick surface layer.  ECTPH22-45cm down just above pencil hard old snow surface in 1finger hard snow.  Old rain crust was buried 90cm deep here, and was well bonded.  

 

Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Wind Direction: 
Southwest
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Snowing and blowing!

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