Vail & Summit County
SnowpackAndrew McWilliams · Jan 11, 2023 · Vail & Summit County
Weather
Snowy and windy up at Arapahoe Basin Ski Area. Ridgeline winds were moderate to strong with some extreme gusts from the northwest. Snowfall was generally S1, but there were periods of S2. Temperatures were in the teens and the wind effect was only noticeable near and above treeline.
Snowpack
There was about 2 inches of new snow when I arrived at Arapahoe Basin. Wind transport was intense above treeline, but quickly subsided as I descended into the trees. East through southeast to south-facing slopes were getting loaded from the strong northwest winds. I dug on a south-facing slope first. The new snow appeared to bond well to a melt-freeze crust that had been at the surface. I was unable to get a small Wind Slab avalanche on a couple of test slopes on the interface of new and old snow. The melt-freeze crust at the interface with the new snow varied in thickness depending on location and appeared to be decomposing already. The weak layer of concern on this south-facing slope is still within the basal facet layer. No depth hoar was noted near the ground in this location. On a northwest-facing slope near treeline, the snowpack was nearly structureless but was still generally supportable to skis, although I did drop into the basal facets in a few spots. The height of snow was about 85 cm in both snowpit locations. In the northwest-facing pit, there were truly only two layers. Basal facets and depth hoar below a layer of precipitation particles, decomposing fragments, and small facets. The concern is the interface of these two layers which had one non-propagating result and one propagating result in Extended Column tests. I observed no signs of instability like cracking and collapsing in my travels today.