Professional Observation

Observation Details

Signs of Unstable Snow

Key Points

We went to Bishop Creek to look for today’s avalanche problems and we weren’t disappointed.

• We saw a ton of avalanche activity from the most recent storm. Many wet loose avalanches and a few wet slab avalanches failed below 9500 feet on all aspects. We saw old crowns from some wind and storm slab avalanches that ran during the same period. Most of these were size 1.5-2 (big enough to injure or bury someone). The most recent slides we saw were loose dry sluffs that likely ran yesterday. (See avalanche obs for more details).
• Above 9500 feet we saw extensive moderate (creeping along the surface) to intense (suspended, makes it hard to see) blowing snow. We watched intense wind loading from north, then northwest, then west, then southwest winds above treeline on the surrounding peaks. On test slopes it was easy to trigger small soft wind slabs and shooting cracks.
• Below 9500 feet, on southeast-facing slopes that had snow between the sage prior to the last rain event, we found that the rain had washed most of the previous snow away. Dry, right-side-up storm snow was sitting right on the sage. It was exhausting trail breaking. (See photos)
• Below 9500 feet, on northeast-facing slopes that held snow prior to the last rain event, we found dry snow on top of wet to moist. There were three crusts between these damp layers. We found the facets at the gound looking more like melt-forms. (See photos)
• We stopped feeling wet snow in the snowpack above about 9500 feet. We dug on a north aspect at 10200 where it was shallow and there were facets at the ground. All the snow in our pit was dry. (See profile)