The Christmas Eve rain crust is creating a tricky, low probability but high consequence scenario, and crust thickness remains the most critical variable.

Our biggest concern is on slopes above 9500 feet, where less rain fell and the crust is thinner and less supportable. While we don’t have an exact pattern for where those thin crust areas exist, recent avalanche activity offers clues. It’s a good idea to build in a margin and avoid terrain similar to the recent avalanches: steep, rocky, and wind-exposed slopes. On most mid-elevation terrain, the crust is several inches thick, making triggering unlikely, but not impossible.

As we move into a more active pattern and add new load from snow, water, and wind, the likelihood of triggering this layer could increase again. Use this time to step back, watch how the interface responds, and re-evaluate terrain choices.

The moderate westerly winds will continue to build shallow, soft slabs up to 2 feet thick near exposed ridges. These smooth, rounded pillows of wind drifted snow are forming on a variety of old snow surfaces. While initial wind-drifted avalanches will likely be shallow, there’s potential for them to step down into the deeper, more dangerous hard slab problem, 1 to 3 feet deep, on upper elevation W-N-E facing slopes.

Outside of the wind zone, sensitive new snow instabilities may exist on all aspects. Even a small loose or soft slab avalanche could run long and far on the supportable crust, especially in steep terrain where the snow surface is smooth and continuous.