Location: Crested Butte Area
Date of Observation: 02/16/2018
Name: Tim Brown
Subject: Remotely triggered slide in Coon Bowl
Aspect: North East, East, South East, South
HS-ASr/c-R1/D2.5-G/O – NE aspect (11,700′-11,200′), remotely triggered a cornice which dropped onto a steep and rocky slope and triggered a large slab avalanche, which stepped out to the side and broke trees.
Several recent slab avalanches on easterly aspects of the shoulder of Red Lady Bowl and above Green Lake on Axtell
Weather: Overcast with thin clouds and strong solar radiation, limited and localized blowing snow along ridge lines from NW after noon
Snowpack: HS 60-160cm with ~ 20-40cm recent storm snow. Large cornices and significant wind loading on easterly aspects near and above treeline.
Forecast danger rating and problem distribution seems appropriate for the terrain we travelled.
SE aspect near treeline: 2 moderate collapses in open meadows, but difficult to determine how deep they were. Multiple crust/facet combinations appeared spooky in snow profile on SE aspect at 11,300′ with HS 105 and PF90cm, but snowpack tests yielded mixed results on these layers (Sudden Fractures in CT’s, ECTP 35+ SC and PST 50-80/100 down 50 and 70 cm on CR/FC combos),