Vail & Summit County
AvalancheDrew Gibson · Jan 2, 2023 · Vail & Summit County
Weather
Increasing clouds through the day. Small squalls passing through delivering brief periods of snow and graupel. Mid 20s at ridgecrest and mostly calm. Little wind transport.
Snowpack
8"-15" of new in places. Winds were calm and up to 10" of snow was found on ridgecrest. The warm temperatures, high humidity, have also been at work as many trees near ridgecrest were rimed. There was evidence of previous wind-loading during the storm. Plenty of evidence of the natural avalanche cycle with avalanches being observed on N, NE, E, SE, SW, and W aspects. Minimal collapsing was observed on a SW aspect and also on a NE aspect. Both times collapses were rumbling and lasted several seconds. Pit data showed the quickly increasing depth in the snowpack on the leeward half on leeward aspects. Extended Column Tests showed hard and fast failures in the 20s on facets under 1 Finger hard snow 73cm down. In the thicker areas the slab is holding up quite a bit of weight, but once the sweet spot is found it fails quickly. Areas like this were where rumbling collapses were felt and heard. Moving around on a SE aspect near treeline, the snowpack is a mixed bag. Areas of deep snow that have been wind-loaded and other areas that have only the storm snow with no additional wind-load. These areas are shallower than the N-NE-E aspects and it is easier to effect the total snowpack. Looking at all of the natural activity on the S aspects this lines up. Shallower snowpack means less weight to get it to fail...Unless you find a pocket on the southerly half that has been wind-loaded.
Avalanche
Many D1 slides observed. All ran during the last period of the storm based on loading near the crown lines.