Aspen
AvalancheDylan Craaybeek Brandon Levy · Dec 13, 2021 · Aspen
Weather
18 degrees F, clear sky and calm winds at the TH at 10:00AM. Sunny all day with Light winds and sporadic Moderate gusts. Sky cover remained between Clear and Few. Some ridgetop snow transport was visible along the higher peaks and ridges but not as much as the past couple of days.
Snowpack
Localized cracking on all slopes with widespread collapsing and shooting cracks on northerly slopes below the treeline. Buried surface hoar was found everywhere we traveled with new surface hoar developing on northerly slopes protected from wind. The buried surface hoar varied between 15cm below the surface on west-facing slopes to over 40cm below the surface on northerly slopes and was on average 2cm thick. Buried melt-freeze crusts were found on many west-facing slopes directly below the buried surface hoar and varied from 4F hard to 1F hard. Ski pen was close to 15cm on west-facing slopes and 30cm on north and east facing slopes throughout our tour.
Avalanche
Observed several old avalanches all likely occurred on Dec. 10 naturally. Avalanches seem to have failed on a layer of buried surface hoar (which existed on top of a crust on westerly aspects) and stepped down through the facets to slide on the ground. Some of the avalanches we observed propagated around terrain features and connected slopes across and through anchors such as trees.