Avy 1 Course, Sherwins Moraine

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SNOWPACK OBSERVATION
Submission Info
Forecaster
Sunday, February 19, 2017 - 3:30pm
Red Flags: 
37° 37' 28.5924" N, 118° 57' 41.4216" W
Snowpit Observations
More detailed information about the snowpack: 

Report from Sierra Mountain Guides Level 1 course:

Toured up from propane tanks parking on the moraines under the Sherwins.

Warm air temperatures mid day: 3deg. C at 1245. Moderate winds. Evidence of recent (past 24 hrs.) loose wet avalanches under the Bluffs originating from rock outcrops, E-SE aspects. Ridge top winds visibly transporting snow from SW winds. (See photos) Some snow transport even down around 8000'.

Variable snow surfaces depending on aspect. Moist surface snow (on all aspects) below 8500'. Solar aspects (E and S) had melt-freeze crusts. SW aspects had well developed sastrugi from wind stripping. Most lee-slope kick tests had no results. One kick turn test in an isolate, low elevation, wind loaded pocket cracked and slid down into the skin track below (<10ft, 20cm deep). No whumphing, no shooting cracks.

Hand shear tests on E aspects pulled with easy to moderate force, planar, about 25cm down on the mid Feb. crust layer (F hard snow over 1F to P hard crust). Shovel tilt tests done on sheltered, steeper, NW aspects showed that a subtle storm instability is still present about 30cm down, easy to moderate tapping. (See photos) Snow depth about 200cm, recent storm snow settled down to between 25-45cm depending on aspect.

 

Snowpack photos: 
Shovel Tilt Test Results
Blowing Snow on Sherwins
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
Air temperature trend: 
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: 

Few clouds at 1000 becoming broken by 1400.

Light snow began falling at 1400.

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