Concerning structure near Happy Chutes and Climax Chutes

CB Avalanche Center 2015-16 Observations

Location: Crested Butte Area
Date of Observation: 02/09/2016
Name: Zach Guy
Subject: Concerning structure near Happy Chutes and Climax Chutes
Aspect: North East, East
Elevation: Below treeline

Avalanches: Most of the major paths around here ran naturally 2/1, but there were still some slopes that looked like they hadn’t. On the more northerly tilted slopes that had slid, the structure is faceting back to 10-15cm of very soft 1mm facets over crusty bed surfaces, and we were able to skier trigger small and predictable facet sluffs.
Weather: Clear, warm temps. Moderate ridgetop winds, no transport observed on peaks.
Snowpack: See video.  January 14 facet layer (1.5-2mm, Fist hard rounding facets, found on E and NE aspects, 60 to 65 cm deep, under slabs up to 4F+ or 1F-) and Jan 29 surface hoar layer(s) (found on NE aspects, 35-40 cm deep) all still consistently propagating in extended column tests. Repeatable ECTPM results on both layers in all pits. On east aspects the Jan 29 interface is a thin crust with ECTN failures. At noon on a due east slope, ~35 degrees, Tsurface was 0*C, T20 was -3*C, and the Jan 14 facet layer was -4*C 65 cm deep. The top 2 cm was very wet, the next ~8 cm was moist. Dry through the rest of the pack. On northeast aspects, the surface is dry and quickly faceting, with both 1mm near surface facets and surface hoar forming.
No collapsing or cracking observed, although the lower angle terrain that we predominantly traveled on has a noticeably deeper and stronger snowpack than steep terrain because of the Christmas wall-to-wall flush.

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Shaded paths that ran 2/1 in this area have small facet sluff concerns now, which indicates how weak they are if we see future loading.

Shaded paths that ran 2/1 in this area have small facet sluff concerns now, which indicates how weak they are if we see future loading.

Surface hoar and near surface facets growing on shaded slopes.

Surface hoar and near surface facets growing on shaded slopes.