The USDA Forest Service avalanche centers are continuing to operate despite the partial government shutdown because of the critical public safety information they provide.
So far this fall, there have been three early season storms that have contributed to the basal layers for this season's snowpack. These occurred on Oct 25, Oct 31, and Nov 13. Significant melt occurred following the Oct snowfall events on all but shaded upper elevation northerly aspects. Snow depths ranging from 3 to 9 inches were observed on shaded N to NE aspects above 8,000' prior to the Nov 13 precipitation event. In some of these areas snow cover was very patchy melt-freeze snow while in the deeper areas it was fairly continuous facet layers. The Nov 13 event brought rain to most areas with an additional 1 to 3 inches of snow above 8,500' to 9,000'.
As daylight hours continue to trend shorter and air temperatures colder, snowfall that accumulates on N and NE aspects will likely remain through the winter. Aspects with more sun exposure may remain subject to melt. It will all depend on how the weather continues to progress.
At this time, any avalanche concerns remain focused on wind slabs. These wind slabs are most likely to form on wind loaded slopes directly below ridgelines and in gullies. Keep I mind that it does not take a thick slab to create an unforgiving avalanche. The shallow snowpack this time of year does not eliminate the risk of avalanches. It does increase the likelihood of impact with rocks and subsequent injury either while caught in a small avalanche or while attempting over snow travel.
The bigger picture concern at this time is the ongoing crust formation, faceting, and weakening of the slowly building snowpack. While not a major contributor to instability at this time, it may become a significant factor in the future if a major snowfall event is deposited on top of a weak faceted early season snowpack.
The non-profit arm of SAC remains hard at work. There are many great events currently on the calendar ranging from educational talks to ski movies to dinner events. Check the events page for more info.
There are also several excellent online avalanche education opportunities available to refresh and/or build your avalanche skills. Choose one from the drop down list under the "Education" tab at the top of this page.
Current remote weather station data as well as a general weather forecast for the area provided by the NWS can be found by clicking here.
This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.