Vail & Summit County
AvalancheJason Konigsberg · Apr 28, 2024 · Vail & Summit County
Weather
Winds weren't a factor near and below treeline. Above treeline northwest winds were drifting snow onto easterly-facing slopes. Temperatures near and above treeline were below freezing. Looking at the temperature history at Vail ski area, temperatures have been below freezing at 11,200 feet since Thursday evening.
Snowpack
The main concern with drifted snow are mentioned in the observation summary. I got easy to moderate propagating test results in ECTs at 15 to 20 cm from the surface on precipitation particles. Beneath the 30 to 45 cm of total storm snow, melt-freeze crusts from before this storm are solid and firm above treeline. As I descended in elevation, these crusts became softer and thinner. At the lower end of near treeline and the upper end of below treeline, beneath this thin and soft crust is wet snow. The wet snow extends to 70 cm from the surface. If we were going into an extended warm-up, this setup would be worrisome for gouging wet loose avalanches. This doesn't look like the case with a small shortwave on Monday night and again on Wednesday night.
Avalanche
I triggered a couple of very small avalanches in drifted snow that ran on a melt-freeze crust that formed on Saturday. I saw a Loose Wet avalanche that skiers triggered while descending a south-facing slope.