Standard route to East Peak; followed ridge north to first subpeak; Begin E-NE descent into Cement Basin
Dec. 31, 2018, 1:15 p.m. PST
Weather: Clear, light wind, 25 degrees F
Snowpack: 5-10 inches new snow on rain crust
Area Description: Crystal BC, Cement Basin, 6600'
Avalanches: Observed tell-tale signs of cross load wind effect on slope below, but we didn't think the slope angle would be enough for a slab to release. Dropped in from the ridgeline. Slab did not release immediately. When I was approximately 75 feet down the slope, my partner saw cracks propagating up behind me and started yelling. I stopped about 200 feet downslope at tree line. Slide was large but slow moving, so I was able to ski out of the way of its path before it reached me. Bed surface was approximately 75' wide and 200' long. Debris ran to about 300 feet. The crown (and slab) ranged from 7cm thick on the windward side to 85 cm thick on the leeward side. It was a cross-loaded wind slab that ran on top of the 12/29 rain crust. Observed no hoar or other bed features conducive to sliding. Just rain crust. From the topo, looks like the slope angle was approximately 37 degrees near crown and 30 degrees in the deposition area. (A bit steeper than we thought when assessing.) There was a single ski track on the upper portion of the slope from earlier in the day, and several further downwind from the slab area.
Observation by Ted Bashor
Did you see any avalanches? Yes
Did you trigger any avalanches? Yes
Was anyone caught in an Avalanche? No