Troublesome persistent slab results

CB Avalanche Center 2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/30/2015
Name: Zach Guy
Subject: Troublesome persistent slab results
Aspect: East, South East, South West
Elevation: 10,000-11,500 ft

Avalanches: No new avalanches observed since Christmas cycle.
Weather: Cold temps (~5 to 10*F). Calm to light westerly winds. Light snowfall tapered late afternoon, about an inch of accumulation during the day. Overcast to broken skies.
Snowpack: 5 or 6 rumbling collapses below about 10,200 feet, becoming quieter as we gained elevation to near treeline. One pit on an ESE slope below treeline had 85 cm of slab over fist hard facet layer. The slab was 1F in hardness near the bottom, up to fist hardness at the top, leaving a sense of “It feels good and stable” while skinning. 3x propagating results in ECT, moderate to hard, Q1 SC. Another pit on a SW aspect near treeline showed a 100 cm slab over a thin, friable crust (1cm thick, 1F hard), over a fist hard facet layer. Slab collapsed on isolation (ECTPV) on first test and after 30 taps on second test (ECTP30 Q1, SC). Quick pit in an old bedsurface from Christmas cycle on an E aspect near treeline showed a mix of meltfreeze crusts and pockets of old facets at the ground, with about 45 to 50 cm of recent snow above, 4F to F hardness.  See VIDEO

Hand hardness profile on ESE aspect below treeline. Repeated propagating failures near the ground on fist hard facets

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