Weak and faceted snow is widespread on the shady side of the compass. Slopes below treeline lack a cohesive slab. As you gain elevation, you may encounter thicker slabs near treeline and above. Slab formation is most pronounced above treeline, and this is where you are most likely to find avalanche problems. There are two main weak layers of concern: facets at the base of the snowpack, and very weak snow found just below the new and drifted snow. We are most concerned about the weak layer in the upper pack. Recently formed slabs are more likely to overload this layer, and avalanches will fail here first. Any triggered slide has the potential to entrain enough snow to step down to the basal facets, causing deep and dangerous avalanches. If you are skiing slopes steeper than 30 degrees, you'll need to carefully evaluate the snow for signs of a slab over a weak layer.

This snowpit from Ryan Huels perfectly illustrates the snow structure we are most concerned with. Note the obvious dense slab on top over weak faceted snow. The diagram also illustrates the weak faceted layer at the base of the snowpack.