Recent Avalanches

Wind Loading

Cracking

Rapid Warming

Poor Snowpack Structure

The early morning light and good visibility helped to identify the overall significance of the avalanche cycle that occurred on Saturday. Three more slides that were not reported on Saturday were: 1.) An 80 foot wide pocket in the steep entrance to the bowl to the rider's right of the V-Tree; 2.) A 200 foot wide slide that was on the steep East facing roll on the rider's right entrance to the Tuscarora Bowl from Catherines; 3.) Almost all of the upper half of the Pioneer Main Chute area. All three of these slides had some kind of human trigger factor involved, and all were Soft Slabs that appeared to have a wind loading component. Slides from Sunday were as follows: 1.) South facing terrain in the Highway to Heaven, Wet Loose, see photo; 2.) North and Northeast facing terrain above the Solbright Trail/Silver Lake, Wet Loose; 3.)The Tuscarora Main Chute (Seagull/3 Chute), this was already reported, yet of note: this slide appeared to be initially started in a slab in the upper third of the Chute and when it broke into the lower Bowl it fractured again. This slide mimiced much of the activity from Saturday. Obviously there was much more Wet Actiivty in the mid to late afternoon on Sunday. Minimal cracking was observed early in the morning on South facing terrain in Dry Fork. The Very Easy Shears that were observed on Saturday just above the old snow interface appeared to have settled out as is typical by early on Sunday morning. This suspect weak layer was yielding Moderate shears in all tests. At 9900 feet on a NW facing 38 degree slope an RB5, Q2 SP was observed. At 10250 on a NW facing 40 degree slope a CT21, Q2, SP was observed. Of note, the second cited pit was in the upper starting zones of Sunset and there was Poor Snowpack Structure at this cite with .5 mm facets resting on top of the old snow interface. The cited shear here was in the same identifed weak layer of Light density Snow, combined with the facets. Also of note here was a 5 cm wind slab that was sandwiching this weak layer with the old snow interface. There was 30 cm of total new load on top of the old snow interface in this location, and it appears that any possible significant additional load on this weak structure may produce another round of propagation and or collapse failure.