Considerable avalanche danger will continue due to wind slab and storm slab avalanche problems. Wind slabs will be likely in near treeline and above treeline terrain. Storm slabs will be likely in near treeline and below treeline terrain. Careful snowpack evaluation, cautious route finding, and conservative decision making are essential today.
Winds slabs will be likely in near and above treeline terrain on NW-N-NE-E-SE aspects. Strong to gale force SW winds will continue through today with additional snowfall.
Look for signs of recent wind slab avalanches, blowing snow, cornices, cornice formation, and wind pillows. Avoid steep wind loaded terrain and run out zones below corniced slopes.
Storm slabs will be likely on all aspects in near treeline and below treeline terrain. Another 1' of additional snow is expected throughout today in the higher elevations with the potential for high snowfall intensity. In areas where slab cohesion does not exist, loose dry avalanches (sluffing) could present travel concerns for backcountry users in steep wind protected terrain.
Look for signs of cracking or cohesion of the new storm snow. Hand pits could provide a good tool for looking at the bonding of the new storm snow. Avoid slopes with signs of unstable snow.
* High elevation rain was reported from Incline Lake Peak (Mt. Rose area). Thin rain crusts were found up to 9200' yesterday morning. Snow began at 11:30am with snow levels around 8000'.
* Large roller ball activity was observed on Andesite Peak (Donner Summit area) with moderate rainfall on Donner Summit throughout the day.
Continued observations on the recent deep slab avalanche problem have shown signs of overall increasing stability. The previous faceted weak layer of concern is now buried 2.5 to 6 feet deep in the snowpack on NW-N-NE-ENE aspects and has been found at all elevations. This layer has gone through varying degrees of rounding at many locations and has gained strength. In other isolated locations, striated faceted grains are still visible under magnification. This previously faceted layer does remain significantly less dense than the strong slab above it. Snowpack tests mostly indicate that weak layer failure and propagation is unlikely, although there have been some outliers. These outliers have been located in isolated areas of Luther Pass, Echo Summit, and Carson Pass. At this time, data does not exist to warrant an avalanche problem.
