Mount Columbia - Wet Slab



Avalanche on SE face of Mount Columbia. 5-6 parties of 2-4 people per group reached the summit between ~12:30pm and 1:20pm. The first group of two snow boarders set off the wet slab avalanche(s), just out of sight of the person reporting. It was not observed if the avalanche was a single trigger point that then split into multiple tracks or if the party set off multiple avalanches (intentionally?) as they were descending. The speed of the avalanche was not observed. A clear headwall could not be made out, but the flank was ~20-25cm thick and the bed surface was the hard old snow surface. It had snowed on the glacier and mountain the previous day. No one was caught in the avalanche(s). The snow on the flat parts of the glacier was much lighter and drier. The snow on the SE face of Mt. Columbia was much wetter and heavier, it was a very sunny the entire day and the slope was perfectly perpendicular to solar radiation. More detailed measurements, observations, and pictures were not taken because more parties still had to descend and we wanted to be clear of the hazardous terrain.