From (5/17/20): "...WS - ASu - R3 - D2 - I SE face of Middle Basin Peak starting at 10,000' Estimated SZ of 30° Slab depth of about 8". We were out too late in the day and chose to ignore a number of observational warnings. We were lucky and remotely triggered the avalanche below us."
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. As seen from the top of Andesite today (5/20) Photo: H. Dougherty
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. As seen from the top of Andesite today (5/20) Photo: H. Dougherty
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. Photo: M. Feller
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. Photo: M. Feller
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. Photo: M. Feller
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. Photo: M. Feller
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. Photo: M. Feller
A very large natural wet slab ran on the afternoon of 5/19 at the Yellowstone Club. (Screenshot from the Y.C. Timberline chair webcam)
Doug McCabe left a message:
A very large wet slab avalanche released on an east aspect of the YC. It was not human triggered. This is the biggest slide he has seen on the shoulder with an estimated 6-8' deep crown. The slide hit a tower. R4/D3.5.
From e- mail (5/20): "Got a better look today. WS-NC-R4.5-D3.5. Trigger looked to be from a cornice fall. The crown was measured at 1800’ in length and ran full path, 950’. NE facing slope at 9840’. The crown was mostly between 6-8’, but ranged from 4’ to 9’. The cornice fall occurred on a shallower section of the snowpack."
