Professional Observation

Observation Details

Signs of Unstable Snow

Key Points

I went for a quick tour in the Sherwins today to get an idea of how our recent warm temperatures are affecting surface snow in shaded areas and to poke my head into the snow near the ridge to see how the Dec 1 pwl is looking in the area.

• Today was quite warm. I measured 44 degrees at 9500’ at 1 pm and I kept thinking it felt a lot like a classic spring California day.
• Despite the warm temperatures the surface conditions were quite pleasant in sheltered northerly terrain above about 8500’ or so. Below 8500 there was a thin zipper crust forming which provided some audibly crunchy turns. Not enough to be a huge concern but a refreeze may stiffen things up a bit overnight.
• Significant settlement cones are visible around several trees. 
• some exposed areas have textured surface snow and/ or some thin wind board but only along the ridge did i find any breakable crust that proved challenging.
• Areas with more solar exposure are a bit moist and sticky, though I didn’t observe anything concerning.
• It took a lot of probing to find an area with noticeably poor structure. I found a good area to dig in on a NE aspect at 9800’. Structure in this location was similar to areas we have seen across the range, a bit upside down. The basal facets in this location are gaining some strength and showing signs of rounding. Stability tests highlighted the 12/01 pwl as our layer of concern but I did not see propagation in my ECT today. (See pit for more details)