The underlying snow pack is weak, but the December drought layer (buried roughly 15 inches deep) is the primary layer of concern. This layer of weak, faceted snow formed near the surface during the December dry spell. A slab now exists on top of this persistent weak layer. Near treeline and below, storm snow over the past week has settled into a thick, cohesive slab. Near treeline and above, elevated winds have stiffened the snow and produced slabs of wind drifted snow over top of this weak layer. This persistent weak layer is most widespread on slopes facing W-N-E, but faceted snow is turning up on all aspects, and it may only be a matter of time before we consider this problem to be widespread.

The video below of an extended column test illustrates the slab's ability to propagate and produce an avalanche:

Shifting winds continue to hammer the mountains alternately scouring and drifting snow on to all apsects. On steep, northerly facing slopes, slabs of wind drifted snow are stressing the "December drought layer," and deep and dangerous avalanches are likely in these areas. Wind slabs have also formed on south facing slopes where they alternate with areas of very shallow snow or even bare ground. Look for slabs on the leeward sides of ridge crests and terrain features such as gully walls and subridges. They are often recognizable by their smooth, rounded appearance, and cracking is a sign of instability. Old hard slabs will support your weight initially and they may sound hollow underneath. Hard slabs may lure you further down slope before breaking well above you. Avoid steep, wind drifted slopes.