Drifting snow from westerly wind at upper elevations will easily build fresh drifts in deposition areas and add weight to existing wind slabs. Avoid stiff and perhaps hollow sounding wind slabs near ridge tops and in and around terrain features like gullies, sub-ridges, scoops, and rock outcroppings. Wind slabs may have formed on weak faceted or feathery snow that was previously on the snow surface, which means the slabs could be reactive to our weight, and the older drifts may stay sensitive to human triggering for a little while.

Wednesday's hard wind slabs rested on weak surface snow, and they were still sensitive to our weight. Hard slabs have a nasty tendency to allow you to get out on them before releasing. Although these wind slabs were pretty small, the hardness makes them less manageable, and more dangerous wind slab conditions likely exist this weekend in some drifted upper elevation areas. (1-13-2016)

The somewhat gradual accumulation on the widespread weak surface snow makes forecasting difficult, but I don't think there's enough of a new slab to create a problem in most areas yet. Before yesterday's snow, we found loose and very weak snow on the surface in many areas, and as a slab consisting of heavy new snow stacks up on it, storm snow avalanches may become more likely. More snow than expected today could cause soft slab avalanches to be possible even in sheltered terrain and at lower elevations. The avalanche danger is likely rise and become more widespread in the backcountry this weekend in areas where (and if) significant new or drifted snow accumulates on slopes with preexisting weak surface snow.