Quick report
- Red Flags
- Recent Avalanches, Heavy Snowfall, Wind Loading, Collapsing, Poor Snowpack Structure
- Red Flags Comment
- <p>We saw at least 3 avalanches, 2 that were likely natural-triggers, and the third on Lake Peak that was remotely-triggered (these were recorded in avalanche occurrences). We also got several collapses, likely collapsing on one of the density inversions in the top 30 cms of storm snow. </p>
The natural and skier-triggered activity today indicated a sensitive snowpack. I am expecting things to remain sensitive for the next 24-36 hours with additional snow and wind in the forecast, and some slides may break down into deeper weak layers. Photo and video describing current snowpack structure.
We also saw evidence of a natural avalanche on a steep, northeast aspect at 9400' in Boulder Basin. Slide observed on Lake Peak, but this has already been covered in a separate avalanche occurrence (link).
Snowpack
- Instability Comment
- <p>New snow avalanches are failing either within a density inversion in the top 30 cms, or down 40-60 cms on a layer of facets or decomposing fragments (DFs) that is at the interface of the Saturday/Sunday storm. Extended column tests were ECTP, failing between 13 and 23 taps, on the layer of facets/DFs. I am expecting this deeper layer will heal fairly quickly given the warm temperatures of the snowpack, but an additional 1"+ of water with the Friday storm may be reactive on this layer, or within the density inversion.</p> <p>We did find a few denser wind drifts today, and the Friday storm appears to be windy as well, so additional fresh wind drifts can be expected for Friday.</p>
About 30 cms of dense snow that is mostly graupel has fallen since yesterday. Snow below ~8500' had dampened on all aspects. The 30 cms of storm snow has different density inversions.