Name: Irwin Guides (CBMG)
Title: Washington Gulch
Location: Crested Butte Area
Date of Observation: 01/08/2015
Aspect: North East, East, South East
Elevation: 9500-11000
WEATHER: Clear skies, hot in the sun, no wind in valley, light winds from NW on ridge top.
Snowpack: SNOWPACK/AVALANCHE OBS: Huge surface hoar growth from valley floor to ridge top. Overall snowpack very weak and unconsolidated. HS average of 60cm valley floor and 120cm at ridge top. Lots of big collapses observed on bottom 1/2 of terrain both on up track and on egress out. These seemed to become widespread and predictable the minute the snowpack structure lacked any cohesive ‘mid-pack’. Upper 1/3 of terrain was characterized by a snowpack structure that was slightly more supportive with ski pen about 20cm. Here quick test profile pits revealed a small (15cm thick) 4F+/1F- hard layer about 40cm below the surface capping the Dec 13th interface and the basal facets. Hand shear tests and compression tests both showed moderate failures on the basal facets directly below this layer The middle 1/3 is the scary tapering thickness persistent slab problem pointed out in CBAC report (0-15cm thick) where skier triggering is likely to occur.
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