Central Sierra Nevada
Avalanche danger
Highlights
LOW avalanche danger continues throughout the forecast region with avalanches unlikely. Isolated areas of unstable snow still exist in places with a shallow and weak snowpack. Normal caution is advised when traveling in the backcountry.
Avalanche Discussion
Avalanches continue to remain unlikely with increasing stability throughout the majority of the forecast region. Strong SW winds will continue today, but with limited snow available for transport, blowing snow and new wind slab development is expected to be limited. Reports continue to come in from areas with a shallow snowpack that are still showing unstable snowpack test results on the Dec. 11 PWL. Most, but not all, of these reports are coming from the southern part of the forecast region in the Carson and Ebbetts Pass areas. While no avalanches have been reported on this weak layer in the last 2 weeks, a weak snowpack structure continues in these areas. If signs of instabilities are encountered (whumpfing sounds, cracking, or unstable snowpack test results) travel plans should be changed to avoid these areas of concern. Practice normal caution to lower your risks while traveling in the backcountry.
Recent Observations:
* The Dec 11 PWL continues to gain strength throughout the majority of the forecast region. Most recent observations are showing continued improving stability associated with this layer located in the lower portion of the snowpack on W-NW-N-NE-E aspects above and below treeline. Stability improvements have occurred more rapidly in the northern 2/3rds of the forecast area where the snowpack is deeper. In the southern 1/3rd of the forecast area, especially to the east of the Sierra Crest in the Carson Pass and Ebbetts Pass areas, the snowpack remains overall shallower and weaker. These areas with a shallow and weak snowpack structure could become more problematic with additional load when our next storm arrives.
* Unstable snowpack test results were reported from Red Lake Peak (Carson Pass area) yesterday on the Dec 11 PWL.
* Recent SW and NE wind events have scoured wind exposed areas down to wind board or firm snow surfaces. These recent wind events have not created any problematic wind drifts or wind slab formation.
* Faceting is beginning to form in some locations around the recently formed rain crust that exists in the upper snowpack in areas below about 7,800' to 8,200'.