Minor wind slabs on Silver Peak

We toured into Silver Peak today to look at wind slabs in near treeline terrain. After a brief period of clearing skies this morning, cloud cover moved in with convective snow showers and sustained snowfall rates at S4 to S5 from late morning through early afternoon. As of 1 pm today storm total amounts had reached 18 inches in wind protected areas on Silver Peak.

Moderate amounts of blowing snow continued throughout the day, refilling ski tracks and continuing to enhance wind slabs. We were able to intentionally collapse a wind pillow that triggered a relatively thin, 4 to 6 inch thick wind slab that propagated 25 ft wide on a N aspect in near treeline terrain. This wind slab occurred on the top of well over 2-3 ft of wind drifted snow from earlier in this storm cycle. We were able to easily trigger deeper shooting cracks in a number of other wind loaded areas but triggered no other avalanches.

We watched another party from afar descend into steep, wind loaded N aspect terrain on the south side of the main east avalanche path of Silver Peak. Shortly thereafter we saw a rising plume of snow in the trees below. It was very difficult to see across that distance in poor visibility from our location on the next ridge to the north, but they may have triggered a wind slab avalanche with around a 1 foot deep crown. A little later as visibility improved slightly, we could see that their tracks turned and skied away from what looked like a crown. We could not tell for certain if we were seeing a crown or other feature in the still marginal visibility.

We ski cut a few steep wind protected slopes below treeline which did not reveal any evidence of storm slabs. These test slopes failed as shallow dry loose avalanches.

We noted some minor snow surface warming and stiffening of the new snow on a west aspect at about 7,400' while exiting the area around 2 pm.