Vail & Summit County
AvalancheDrew Gibson · Nov 30, 2022 · Vail & Summit County
Weather
Clear and cold in the morning at the trailhead. 10 degrees at 0900. Temperatures climbed into the 30s near 10,000ft. Ridge top temperatures were in the mid to high 20s. Winds were light from the west above treeline. Areas in the sun and sheltered from the wind were hot.
Snowpack
Below treeline the snow pack is not much deeper than 60cm. It is supportive in many places due to old buried tracks. Near and above treeline the effects of the west winds are apparent. Large and deep wind rows exist behind trees, rocks and other prominent features. Many slopes near ridge crest are stripped of new snow and only wind pack remains. On leeward aspects slabs were difficult to find on slopes near 30 degrees. On observed east and northeast slopes the snow pack was comprised of mostly facets under the new snow/wind load. Test pits showed failures under the new snow/wind load with easy test scores in both compression and shear. ECT's had no propagation but blocks did fracture and break on the basal facets directly under the shovel. Steeper, leeward slopes (>30 degrees) looked loaded and pillowy. Only a few natural avalanches were observed.
Avalanche
Observed 4 avalanches from a distance from the ridgeline above Lost Lake. Observed 3 avalanches for a distance from Highway 91 near Mayflower Gulch. All avalanches but 1 looked like they ran mid-storm based on how the crown lines were filled in.