Beaver Creek

Very warm ambient air temperatures today, with either some light rain falling up to ~8,400 or some direct precipitation from wet air/clouds into the snowpack resulted in some liquid water at the snow surface. The upper 10cm of the new snow were becoming moist, even on shaded slopes above 8,500 (able to make some nice cinnamon rolls and roller ball swarms here). The slab overlying 1/6 continues to settle, consolidate, and gain strength.

I did not feel comfortable approaching the crowns of the rider-triggered slides from the day before, but I was able to make it close enough to dig a representative pit in sheltered terrain. Here, I found 8-10mm SH standing upright buried on top of the 1/6 interface. This was very likely the culprit weak layer for these large avalanches. Underneath this surface hoar are well developed facets. Riders initially reported a single avalanche failing, and then several other large pockets opening up sympathetically. The distance from the triggering location to the furthest away portion of crown was over 0.5 miles (2,500'). 

As I walked on the ridge between Beaver and Johnson Creeks I remotely triggered at least two large to very large avalanches. One of these appeared to sympathetically release another D2.5 as it traveled downslope. I experienced at leat 6 other starting-zone size collapses as I traveled. These were occurring in both shaded and solar terrain. The nature of this set of weak layer is impressive and unusual - it is not terribly common to get "productive" weak layers on both shaded and solar slopes.