Brush Creek TH area – collapse city and remotely-trigger avalanche

Date of Observation: 12/31/2020
Name: Eric Murrow

Zone: Southeast Mountains
Location: Low elevation east-facing terrain at bottom of Mount Crested Butte above East River
Aspect: North, North East, East
Elevation: 9,000 – 9,800′

Avalanches: Remotely trigged 3 very small D1’s on east-northeast aspect from a single collapse that propagated around 300-400 feet
Remotely trigger a D2 avalanche from about ~500 feet away that traveled through several terrain features and mature aspen groves
Weather:
Snowpack: Slopes very near valley bottom felt incredibly weak and produced regular collapsing but only traveled 20 or so feet. As I ascended just a few hundred feet above valley bottom on east and northeast terrain, the collapsing started to propagate hundreds of feet to slope scale size. Slab formation since 12/10 is only about 40cm thick and mostly fist hard with a small amount of 4finger. It rests on well-developed facets around 3mm in size. Total depth on east and northeast slopes averaged around 65cm. The snowpack was screaming to avoid all avalanche terrain and so that’s what I did, but managed to be surprised by collapses rolling through low-angled, mature aspen forest and triggering adjacent slopes. The snowpack in this area is incredibly reactive and steep slopes feel like a sure bet for an avalanche.  Small surface hoar observed on northerly slopes.

Photos: