Aspen
AvalancheDylan Craaybeek · Dec 27, 2023 · Aspen
Weather
Cold, clear, calm day. Light breeze along the ridgeline from the northwest, no visible snow transport, and a very cold morning not warming up very much. The temperature was 18F at the trailhead around 9:30 AM and the Snowmass Timberline weather station at 11,522 feet recorded a high temperature of 17F today.
Snowpack
Below the treeline, the snowpack is thin, with a height of snow (HS) less than 40cm, and weak with ski penetration going to the ground with almost every step. At these lower elevations, the snow is fully composed of facets on all shady slopes with no sign of any slabs or any snow harder than 4F- on the hand hardness scale. Near the treeline (NTL) from around 10,800 feet to 11,500 feet HS was around 50-80cm with some signs of discontinuous slabs of 4F hard snow on wind-loaded terrain features. On the wind-loaded slopes where there were some slabs NTL, you could easily see small shooting cracks reaching a few feet in front of you but none of the slabs extended across any individual slopes or even more than a few meters. You might still be able to trigger an avalanche on slopes like these but it would likely be a small avalanche no larger than a D1 and not capable of propagating across the entire slope. Above the treeline (ATL) on the lee side of Willoughby Ridge were the only slopes where there was a continuous slab over a persistent weak layer. Snowpack tests showed propagating failures on less than 15 taps every time and there were still some signs of shooting cracks and small collapses on small test slopes, although no avalanches were triggered or observed. The slab around and above 11,500 feet is composed of faceted rounds from previous wind-loading and about 1F hard. Extended column tests were failing on a layer of 2mm facets directly below the slab and not on the well-developed depth hoar near the ground, although any avalanches that fail higher up in the snowpack will likely gouge down into the weak facets and run on the ground.
Avalanche
Several Loose Dry avalanches were observed on slopes steeper than about 40 degrees and easy to trigger near and below the treeline on similarly steep slopes.