Natural avalanches ATL

CB Avalanche Center 2016-17 Observations

Location: Brush Creek Area
Date of Observation: 03/01/2017
Name: Zach Guy
Subject: Natural avalanches ATL
Aspect: North East, East, South East
Elevation: 9,300-12,800

Avalanches: Numerous natural D1 to D2 soft slab avalanches, mostly on easterly aspects above treeline (NE to SE). Based on crown thicknesses and snow structure obs, I assume that most of these failed on the crust/facet layers buried about 18-24″ thick. There were also a few D1 shallow wind slabs. See photos.
Weather: Cold, clear, light winds with no transport.
Snowpack: Below treeline, 12-18″ of soft slab down to the concerning persistent weak layers (crusts/facets).
Above treeline, highly variable slab thickness and distribution due to westerly winds. Most westerly aspects are scoured away. One crown profile on an ESE aspect showed 20″ of F to 4F slab over a thin melt-freeze crust with 1-2mm facets above and below. Extended column failed on isolation (ECTPV, SC).

D2 NE aspect NTL. X Chutes on Whetstone. Ran a long way.

D2 E aspect near White Rock Mountain.

D2 E aspect ATL. Near White Rock Mtn

2xD1.5 NE aspect Double Top

D1.5 NE aspect Double Top

ECTPV on 1-2mm facets below a 1 cm MFcr, 50 cm deep. ESE aspect ATL.

D2. SE aspect Hunter Hill

D1.5 SE aspect Hunter Hill

D2. NE aspect Double Top.

D1.5 E aspect Hunter Hill

D2. SE aspect Timbered Hill

D1.5/D2’s. E and NE aspects above West Brush Creek

D2. N aspect ATL. Lambertsons Peak

D1.5 East aspect ATL. Hunter Hill

D1 windslab. E aspect, Star Pass.

D2. NE aspect ATL. Carbonate Hill