Vail & Summit County
AvalancheAndrew McWilliams · Mar 11, 2023 · Vail & Summit County
Weather
Light snow and overcast skies turned broken by noon and precipitation stopped. Winds increased to moderate from the west.
Snowpack
There was about 25cm of new snow in Montezuma. I ascended on easterly-facing slopes. Below treeline I found snow depths of around 160cm. Near treeline this increased to 180cm to 220cm. The new snow was fist-hard on the Hand Hardness Scale and had not formed a slab. I saw multiple loose dry sluffs on steep slopes that faced easterly and northerly that likely ran during the heavy snowfall. In the upper meter of the snowpack below the new snow, I found a one-finger to pencil-hard snowpack primarily composed of rounds and rounding facets. A thin 10cm layer of facets sandwiched between two pencil-hard layers was unreactive in snowpit tests. The new snow had easy propagating results in Extended Column Tests and easy, sudden collapses in Compression Tests. These results were focused on a slight density change within the new snow about 10cm above the new/old interface. These easy results corresponded well with the natural activity observed around the area. As I ascended the ridge, large chunks of cornice calved off easily and triggered small avalanches within the new snow just below the cornice. If I was on a steeper slope, these avalanches may have been able to run farther and entrain more of the new snow. There were no other signs of instability in the new snow like cracking or collapsing. Wind speeds increased as I descended and will likely build wind slabs on easterly aspects tomorrow.
Avalanche
Multiple small avalanches on steep northerly and easterly-facing slopes.