Frog Lakes Area - Viriginia Lakes

A relatively calm day today before a major weather system impacts the Sierra and adjacent communities starting tomorrow. We toured into the Alpine near the Frog Lakes basin to see how reactive the wind-affected snow was. The wind event from earlier in the week had touched almost every surface in this area. We noticed sastrugi and large wind-sculpted formations in the snow. North-facing slopes were stripped almost bare in spots. We were able to find some shelter and dug a pit at around 11,010 ft on a northern 30-degree slope. A hard wind slab was present on the surface.  It seems unlikely to trigger an avalanche in the current conditions and I am also not ruling it out. Yesterday in the BWRA there were many machine tracks in all the steep riding zones. One rider triggered a wind slab in McKay Creek and submitted a photo of the slide. The area we were in yesterday had mostly wind-stripped snow, the two areas are next to each other highlighting the large amounts of spatial variability that can be present in the mountains, especially when the wind has blown all the snow around. 

Several breaks in the hard wind slab snow. Compression Tests followed by Extended Column Tests produced breaks 10cm's below the surface and 40 cm's below the surface. Both were quality 2 and resistant planar breaks and broke from the elbow. ECT produced propagation across the block in both tests.  Mutliple layers of wind slab existed in this location. The hardness of the surface snow was pencil and we didn't have any ski penetration in the Alpine. A few soft patches of snow were found in the wind-sheltered near treeline north-facing trees during our route up to our location in the Alpine.