Large avalanches on Emmons

Location: Crested Butte Area
Date of Observation: 12/16/2016
Name: Zach Guy
Subject: Large avalanches on Emmons
Aspect: North, North East, South East, South, West
Elevation: 9,600-12,000

Avalanches: Very little margin for error in terrain selection today.
Below treeline, we observed widespread natural storm slab avalanches and skier triggered a handful, all small in size. SS-N/ASc-R1-D1/1.5-S
Near treeline, we observed two large natural persistent slabs, 2 to 3 feet deep, failing on facets near the ground. One on a NE aspect and one on a SE aspect. SS-N-R2-D2.5-O. We also remotely triggered 2 large persistent slab avalanches from ridgelines ~1-4 feet deep on the ground, one of which was triggered by a remote cornice fall. NE and N aspects near treeline. Debris ran far into flats and snapped numerous small trees. SS-ASr-R2-D2/2.5-O. Video to come.
Weather: Pacific northwest!! S2 most of the day with stronger pulses at time. Light winds below treeline, strong to extreme winds above treeline from NW and SW. Intense snow transport during gusts. Warm.
Snowpack: 45cm of dense, new snow over well-documented PS structure, weak snow near the ground. Ski pen ~shin to knee deep. Lots of moderate collapsing, a few large collapses on various aspects. Widespread cracking on a density difference (stellar dendrites) mid storm, about 20 to 25 cm deep.

Spiderweb cracks BTL

Spiderweb cracks BTL

Natural persistent slab. Climax chutes

Natural persistent slab. Climax chutes

Small natural storm slabs.

Small natural storm slabs.

Natural persistent slab, SE aspect NTL.  Coon Basin

Natural persistent slab, SE aspect NTL. Coon Basin

Natural persistent slab, SE aspect NTL.  Coon Basin

Natural persistent slab, SE aspect NTL. Coon Basin

Remotely triggered cornice fall/ persistent slab avalanche.  NE aspect of Coon Basin.

Remotely triggered cornice fall/ persistent slab avalanche. NE aspect of Coon Basin.

Remotely triggered cornice fall/ persistent slab avalanche.  NE aspect of Coon Basin.

Remotely triggered cornice fall/ persistent slab avalanche. NE aspect of Coon Basin.

Remotely triggered cornice fall/ persistent slab avalanche.  NE aspect of Coon Basin.

Remotely triggered cornice fall/ persistent slab avalanche. NE aspect of Coon Basin.

Remotely triggered persistent slab avalanche.  N aspect of Coon Basin.

Remotely triggered persistent slab avalanche. N aspect of Coon Basin.