Vail & Summit County
SnowpackAndrew McWilliams · Dec 10, 2024 · Vail & Summit County
Weather
Moderate westerly winds, light snowfall, and temperatures near zero.
Snowpack
We observed two layers of concern on east-facing near treeline slopes today. The first was a thin layer of buried near-surface facets below the most recent snow. You could cracking within the new snow as you traveled and one group member reported shooting cracks. On a small, steep test slope, I was able to break a small slab of this new snow off into the creek with little effort. The layer of new snow was fist to one-finger hard on the Hand Hardness Scale depending on wind exposure and its thickness varied over short distances. The second weak layer of concern was at the interface of the basal facet layer and a pencil-to-one-finger hard layer of faceting rounds just above it and below the Thanksgiving Week storm snow layer. We dug several pits and our test results showed a range of results, but regardless of whether results propagated or not, they consistently identified these two layers. The layer just below the surface failed with taps from the wrist. Where this new slab was thicker there were propagating results, where it was thinner they were non-propagating, and where it was softer there were no results. The layer closer to the ground failed after blows from the shoulder or elbow and propagated in one test, but didn't in multiple others. As the weak layer near the ground is becoming less reactive, we might be developing a new weak layer of concern in the upper snowpack.