Easterly facing slope on Mt Starr

easterly facing slope of Mt. Starr
Submission Info
Tuesday, December 13, 2016 - 3:45pm
Red Flags: 
Whumphing noises, shooting cracks, or collapsing
37° 26' 38.4432" N, 118° 45' 12.1176" W
Snowpit Observations
More detailed information about the snowpack: 

-Gate locked at snowpark parking ~1.7mi before Rock Creek Lodge.  Rd clear and dry for first 1/2mi, then quickly covered with snow up to about 3" at Rock Creek Lodge, ~4" at Rock Creek Pack Station (~2.5mi in from gate, 9,900').  Headed up slope to northern most east facing gully on Mt Starr up to ~11,200'.  Thin snow cover most of the way (4-8" of dense suportable snow), lots of rocks/obstacles to dodge and scrape.

-Snowpack was moist all the way to ground up to ~10,200', then above that temps were cooler and snow became drier.  Pit dug ~11,000 on 38deg NE facing sidewall of gully.  This was a wind deposited area.  2 significant wumphs were heard/felt at this elevation on this slope.  See attached snowpit diagram for details.  60cm total snow depth in this wind deposited area.  SE facing sidewall of this gully was stripped to bare ground/rock.  Obvious raincrust about 2cm above ground, about 2cm thick, covered by a 10cm thick well defined layer of loose facets.  Above this sat a slab of 45cm of cohesive snow.  ECT tests propageted cleanly with moderate force and CT tests failed with Q1 fractures with moderate force at the top of this facet layer (see attached video).

-Impressions:  There are quite a few larger pieces of talus scattered throughout this slopes acting as anchors through this weak faceted layer at the moment, in other areas with smoother ground surfaces it seems a human triggered avalanche could be possible with this snowpack structure in wind loaded areas.  If heavy snow comes as forecasted this Thursday night, natural avalanches failing on this facet layer would seem highly likely.     

Snowpit or crown profile photo or graph: 
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Warm day, strong south winds at tree line.  Air temp below 10,000' above freezing at 3:30pm.  

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