Large natural avalanche in Drifter Bowl

This large natural avalanche likely occurred yesterday afternoon based on amount of snow on the bed surface of the slide. This slide occurred on a N-NE facing heavily wind loaded bowl. The slide initially failed on a density change between the snow that fell on the 23rd and the snow that fell on the 22nd. This initial crown was only 1-2 ft deep. It then stepped down to the facet layer above the rain crust (Dec 12th facets). This caused the avalanche's crown to become 4-6 ft deep across the bowl. The resulting slab was very dense and hard as was the debris.

Photo 1 and 2: Crown line on the N side of the bowl. Note the large debris blocks in the photo as well.

Photo 3: A view of a section of the bottom third of the slide path. Note the medium sized trees that were bent horizontal by the slide. Also the uphill branches have been broken off the larger tree in the foreground up to about 10-12 ft off the ground.

Video: Overview of the avalanche scene.

From the ridgeline above Drifter Bowl, several natural avalanches were visible in the distance on the east side of Donner Peak, on the N-NE-E aspects of the peaks at the head of Negro/Billy Mack Canyon, on Mt Judah, and on Frog Lake Cliffs.