Donner Summit

We did a tour on low angle terrain to assess the snow pack on donner summit.  We were in a reassessment mindset and wanted to find a safe N/NE aspect slope to see if we could find any of the deep faceted weak layers.

Skies were overcast with intermittent but regular snow showers and light to moderate winds out of the SW.  Travel was difficult and slow with the deep new snow.  We saw signs of recent snow settlement and did not see or hear any obvious or wide spread cracking or wumpfing throuout the majority of our tour.

We attained a small exposed ridgeline at about 7280' with some cornice build and windloading on NNE slopes.  Small soft cornice kicks did not yield any obvious cracking or failures in the low angle NNE facing slopes below.  Snow was actively transporting and filling our skin track on the ridgeline despite reletively low wind speeds.  

We decended off the ridge onto the NNE slope to dig a test pit and felt some minor settlement wumphing and cracking that did not seem to extend beyond our skis.

320cm total snow depth with 168cm of new soft snow.  The new snow was right side up and did not have any obvious layering within it.  We were in a low angle area below the ridge that did not seem to have any obvious pillowing or wind slab.  Our ECT revealed some non-propagating layering within the new snow largely along transitions of relative hardness.  There was a thin but easily identifiable layer of 2-4mm graupel at the new/old snow interface.  We targeted this layer with a Deep Tap test and while it was hard to initiate (DT22), it broke cleanly and sheared easily and came off as a block with a light shovel pull.  There were a number of ice layers and softer looser more faceted layers beneath the old snow surface, but in this location they did not seem to form a contiguous or reactive layer.  There were pockets of loose faceted snow, ice chunks, ice layers, and more loose snow that suggested a rough snow surface prior to the latest snow, and did not fail even when we pried on them.