Couple Of Small Skier Triggered Wind Slabs

CB Avalanche Center 2019-20 Observations

Location: Crested Butte Area, Mt Emmons
Date of Observation: 12/30/2019
Name: Evan Ross
Subject: Couple Of Small Skier Triggered Wind Slabs
Aspect: North East, East, South East
Elevation: 9,200-12,000

Avalanches: Coupe of small skier triggered Wind Slabs to D1.5 with crown depth 30-40cm. SE aspect, above treeline.
Several skier triggered loose snow avalanches on NE to E to SE at NTL and BTL elevations. All small and moving slow.

Weather: Clear sky, calm wind, cold temps.

Snowpack: Wonderful ski conditions. The specific terrain that we found ourselves managing was previously wind-loaded terrain. This was were you could find the best distribution of Persistent Slab Structure and/or today’s forecasted Wind Slab Problem.

NTL SE facing slopes only had the potential for concern where they were wind-loaded. Otherwise the snowpack is generally weak and mixed with crusts. In this terrain, the 12/26 thin crust may be the first to collapse into the 12/24. Though there are several layers of concern in the snowpack. A decent load and a new slab will need to happen to see the PSa problem expand and become widespread on this aspect. 1.5 SWE, or closer to 1.2 SWE in a quick loading event.

NE NTL/BTL elevations were weak and not concerning for a slab avalanche problem in this terrain. HS was about 90cm. A few skier triggered sluffs, but they were stubborn, slow, and easy to manage.

Couple of small Wind Slab Avalanches on an East to Southeast facing slope above treeline.