South Peak - New Snow Stability, Wind Slab, Persistent Facets

SNOWPACK OBSERVATION
South Peak
Submission Info
Forecaster
Monday, March 19, 2018 - 2:45pm
Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
South Peak 38° 2' 29.04" N, 119° 15' 15.12" W
Snowpit Observations
More detailed information about the snowpack: 

Observer: d lewis
Loc: South Pk
Lat/Lon:38.0414, -119.2542
Elevation: 8123 f
Aspect: NE Angle: 34°
Signs of Instability: Wind Loading
Sky Cover: -BKN
Precipitation: No Precipitation
Wind Speed: Calm
Current Temp:-3.5°C
Snow Depth: 225cm
New Snow Storm:36cm 
Snow Temperature 20cm:-8.5° C 
Boot Penetration: 45cm 2 Stability Tests: CT16 Q3 31cm Weak Q3 partial collapse of the column CTN Q3 120cm Not able to duplicate. 

Toured up on to the shoulder of South Peak to assess the new snow stability, deep persistent facets, and recent Wind Slabs. Snow profile shows mostly a right side up snowpack with the exception of facet/”new snow” interface where there is a distinct density change and a large change in snow grain size.  Stability tests were unable to duplicate the failure. No collapsing or whoomfing noted. 1 recent D1,R1 Loose Wet – SE aspect, 10,000’ on the shoulders of Black Mtn (steep rocky terrain feature). Drove up Lundy Canyon and noted an addition Loose Wet Slide on the flanks of Excelsior Mtn (D1.5, R1, Aspect SE, Elevation 9500’, steep rocky terrain). Ambient air temp below freezing at 10,700' but snow is warming and forming a melt freeze crust on solar aspects and low angle terrain that receives direct sunlight. Crust maturity depends on aspect, elevation, and solar exposure duration. Consistent 40-50cm (16 to 20") from 3/16. Very minimal wind effect below treeline (~10,000), at treeline some crossloading noted from westerly winds. Slabs becoming supportive (1F), overlaying fist. Possible concern in steep complex terrain.   

 

 

Snowpit or crown profile photo or graph: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming
More detailed information about the weather: 

Very light variable winds, building thin cirrus during tha PM. Solar aspects begining to warm. 

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