Winds will be increasing from the southwest today and transporting snow to the leeward (or downwind) side of ridges, gullies, and other terrain features. Cohesive slabs of this wind drifted snow will create the largest and most dangerous avalanches today that should be easy to trigger. On most slopes these wind slabs will be resting on a weak layer of faceted snow that formed during two weeks of dry weather in the middle of November.

These wind slabs will cover wide areas, and the most likely places to find them will be upper elevations where southwest winds will be the strongest. However, look for them at mid and low elevations as well. Avoid these slopes.

Dry and cold weather during the middle two weeks of November created a persistent weak layer (PWL) of facets on nearly all slopes. To make matters worse, there may be a layer of surface hoar (another PWL) on top of these facets. Both layers were capped and loaded 1-2 feet of snow from the storm that ended yesterday.

On slopes that received sunshine and ones at mid and low elevations during a brief warmup around Thanksgiving, there is a fragile ice crust on top of this persistent weak layer. This ice crust doesn't really change the situation except on steep slopes facing due south where the ice crust is much thicker and stronger.

As mentioned above, the biggest and most dangerous avalanches will be on wind loaded slopes because the slab of snow on top of this weak layer is more cohesive and thicker. I still expect avalanches will be triggered on this layer on slopes not loaded by winds, but these slides will be smaller and not break over such wide areas. Warmer temperatures today should help consolidate the new snow, helping it become a more cohesive slab.