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.


This Avalanche Advisory was published on November 13, 2012:

November 13, 2012 at 17:14 pm

Early season conditions update #5

We are returning to full staffing levels this week. We plan to resume daily avalanche advisories as storm systems affect the forecast area at the end of this week. In the mean time we will continue sharing all of the information we gather on our observations page.

Forecast Discussion:

We are ramping up the program for this season, but for this week we are still working with very limited resources and observations.

Coming out of the storm cycle from last weekend, the snowpack has stabilized. Overall, very little snow exists on south and west aspects. What is there will continue to melt this week. North and northeast aspects hold a bit more snow, generally 1 to 3 feet deep at the mid and upper elevations. Old snow surface conditions are generally a mix melt freeze crust and warming affected recent storm snow. Isolated pockets of unconsolidated snow exist in areas of full shade at the upper elevations. We are watching the middle snowpack for the formation of near crust facets. So far, no significant weak layers have been observed.

A series of storm systems is forecast to bring rain and snow to the forecast area Friday through Tuesday. Until that time avalanche concerns are minimal. The greatest hazards out there are rocks, down trees, and stumps that lie hidden just beneath the snow surface. Impact with these objects can greatly increase the consequences of a fall or crash.

When traveling in the backcountry continue to make constant observations and look for indications of current or recent snowpack instability. The best indicator is recent avalanche activity. Wind loading, collapse, audible whumpfing sounds, shooting cracks, and/or test slope failure also represent excellent indications that an unstable snowpack exists in the immediate area. Once an unstable snowpack has formed, the only additional ingredients necessary to create an avalanche are a slope steeper than 30 degrees and a trigger.

If you plan to embark on some early season adventures in or near avalanche terrain, each person should travel with avalanche rescue equipment including a transceiver, probe, and shovel with which they are well practiced. Allow only one person at a time to travel on slopes that are steeper than 30 degrees. Getting out and practicing companion rescue skills remains one of the best activities at this time.

Check out the avalanche tutorials specifically designed for skiers and snowmobilers at the Forest Service National Avalanche Center web site.

Current remote weather station data from the NWS can be found by clicking here. A general weather forecast for the area can be found by clicking here.


The bottom line:

Early season conditions update #5

We are returning to full staffing levels this week. We plan to resume daily avalanche advisories as storm systems affect the forecast area at the end of this week. In the mean time we will continue sharing all of the information we gather on our observations page.


Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature: deg. F.
Max. temperature in the last 24 hours: deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours: mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: O inches
Total snow depth: inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

For 7000-8000 ft:
  Tuesday: Tuesday Night: Wednesday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:
  Tuesday: Tuesday Night: Wednesday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.