Vail & Summit County
AvalancheAndrew McWilliams · Jan 27, 2023 · Vail & Summit County
Weather
Single-digit temperatures to start the morning warmed into the teens by midday. Broken to overcast skies with intermittent flurries throughout the morning. Winds were light near and below treeline and I could not discern a direction. There was no snow accumulation by midday.
Snowpack
The snowpack was supportable for uphill and downhill travel and I did not drop into older snow at any point. There was 5cm of new snow resting on 20-30cm of decomposing fragments above the mid-pack slab that was fist to four-finger on the hand hardness scale. The slab was composed of faceted grains one-finger to four-finger hard about 50cm thick. Below this layer was facets and depth hoar to the ground; fist to four-finger hard. Small test slopes on northwest and west aspects had no signs of instability with ski cuts and I did not notice any cracking or collapsing as I traveled. Extended Column Test, Propagation Saw Test, and Compression Test results support a stubborn Persistent Slab avalanche problem with the persistent weak layer being basal facets and depth hoar 80-90cm below the surface.
Avalanche
Observed a recent, small avalanche on a southwest-facing slope above treeline below Peak 12,936. This avalanche likely ran in the past one to three days based on the look of the debris and other observations nearby on similar slopes.