Ongoing Signs of Instability on Silver Peak Near an Avalanche that Occurred on 3/25

We toured into Silver Peak to try to look at avalanches reported in that area since Wednesday. On our way in, we stopped several times to dig quick hand pits looking for buried surface hoar. We did find the surface hoar buried between 10 and 14 inches below the surface on many open northerly facing slopes below treeline and near treeline. In some of the near treeline areas, wind loading had buried the layer a bit deeper. Identifying the surface hoar proved challenging. Fortunately, a graupel layer at the base of the recent snow and a crust just below the recent snow provide great markers to help locate where the surface hoar should exist in the snowpack. We did several snowpit tests in near and below treeline terrain and got unstable results on all of them (ECTP 15, 23, and 19 {video below}). One of these snowpit tests was next to a wind slab avalanche that failed on this layer sometime on Wednesday (details below). We also saw the other avalanches that were reported yesterday but could not access the most recent one.

Given all the unstable test results, recent avalanche activity, and the presence of the surface hoar layer, we made conservative terrain choices and stayed on low angle terrain on northerly aspects. The snow on these aspects remained cold, soft, and fast. 

On our descent, we did find a suitable north facing test slope small enough to ski cut. Our ski cuts only produced loose sluffs of surface snow. In this more sheltered area, the recent snow was softer and less slab-like. On another more sun-exposed E facing test slope ski cuts produced small pinwheels and roller balls at 11 am. As we exited the area around 1 pm, wet sticky surface snow had started to form on sunny slopes.