North, South East, South

CB Avalanche Center 2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 12/11/2016
Name: Evan Ross
Subject:
Aspect: North, South East, South
Elevation: 10,000-11,500

Avalanches: D2’ish debris in the runout of East Bowl. Debris only had a dusting of snow on it, but the crown wasn’t visible in the start zone as it has been filled back in by recent wind loading. Didn’t observe the extent of the debris or crown to estimate any more details.
Weather: Snow showers ended mid-day as overcast sky became mostly cloudy for the afternoon. West/south west winds were generally light with a few stronger gusts. Snow plumes were visibility off most of the peaks during the first half of the day, then fewer in the afternoon.
Snowpack: About 8″ of new snow in the last 24hr. Dens and thicker on top on northerly slopes and softer/more uniform on southern slopes, due to wind effect. A few audible collapses on all aspects but no cracking even on suspect terrain features and on previously untraveled slopes.

North aspect at 10,700. HS 128. 13cm thick layer of facets at the ground were large (2-3mm) and striated, but appeared to have been preciously moist with more of a 4f- hardness to them. The more concerning interface was the 12/6 NSF. This interface was mixed forms .8-1mm NSF and DF. ECTP 26 SP at this interface. No other results while traveling on a number of suspect slopes with this structure. (Some of these slopes likely had previous skier traffic.)

South aspect at 11,100ft, slope 34 degrees, HS 97cm. Most concerning interface was again the 12/6 interface, crust. At the pit location this crust was 4cm thick and produced an ECTP 24 SP result on top of the interface. Where this crust was thinner, around 2cm and softer, observed several concerning collapses below this crust in rounding faceted grains. Didn’t find a theme to these thiner/softer crusts, maybe more southeasterly slopes or lower angled slopes. Never the less, no shooting cracks or results on a number of trigger points and concerning terrain features, but maybe we just didn’t push it far enough looking for a more obvious answer that didn’t need to be found.