Copper Mtn

We observed several slab avalanches that released from Sunday into Monday. They occurred on middle and upper elevation slopes facing NE-E-SE, where recent wind loading and underlying weak snow overlap. 

Ski length cracking when stomping above an open snowpit on a shady WNW @ 8,500'. Cracking associated with near-surface facets down 35 cm.

We set out to look for natural activity from Sunday night's storm and to assess the character of the slab avalanche problem. Total snow amounts since (2/8) range from 20 cm at highway level to 35 cm at 8,800'. Down low, storm snow felt well-bonded to rough crusts on all aspects. 

The most concerning snowpack structure we encountered straddles middle and upper elevations on shaded, generally wind-sheltered slopes. In these areas, the weak layer caused by the month-long drought has been minimally disturbed by temperature crusts, sun, and wind. The picture of the pit below was taken in a wind-sheltered area. There, the weak layer was "good" but the slab was generally too weak (F→4F-) to cause long collapses. We were most concerned with areas where near-surface facets and wind-loading overlap. 

Areas where a crust exists at (2/8) appeared well-bonded where we looked, although rapid loading during Sunday's storm may have overwhelmed some thin crusts + facet combinations on ESE-SE margins. We did find small facets beneath these thinner crusts on Copper, and this combination is something to watch if/when we build a larger slab in more areas.