Big Sky Ski Patrol

suspect strong surface TG with cold temps and intense solar, RRC

50 to 60 foot wide, crown depth up to 60cm averaging 50cm for 20 feet at the center with flanks averaging 20cm deep. avalanche track ran over rocks for 150 feet before merging into the natural path through the gully. Avalanche was triggered by a skier, the skier rode the avalanche to the toe of the debris but was not buried. HS-ASa-O-R2-D2

Crown profile dug on west flank of explosive triggered avalanche.

Most of arch rock 80-90cm, very suspect with a load. Headwaters all 1.5-2.5m.

significant bomb crust near surface. Most depth hoar was more like 30cm thick layer. Layer 99-73 had vertical percolation columns, either from melting snow around bombs crust during last weeks warm/solar, or the initial heat of the explosive detonating.

occasional bomb dust throughout pit

Poor structure, good strength, low energy. Stability conditionally good.

pit was next to the crow of the deep slab avalanche that failed on 01/26/19, in the snow that did not avalanche.