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 25, 2006:


November 25, 2006 at 1:00 am

Forecast Discussion:


This advisory was posted on Saturday, November 25, 2006 at 3:38 pm

Increasing cloud cover expected over the forecast area as the next weather system approaches our area. Ridge top winds are expected to increase Sunday afternoon prior to the onset of snowfall. Temperatures are expected to remain cold into early next week.

The existing snowpack is very shallow with up to 40cm of snow found on north aspects above 9,000'. Many areas on east, south, and west aspects are void of snow, especially below 9,500'. Most areas of snow on north aspects above 9,000' are a mix of crust and weak faceted snow layers. This is typical of any early season, shallow snowpack. These layers exist under a hard surface crust that is keeping this snowpack relatively stable. Around 2 inches of snow was deposited on this crust in most areas Wednesday night. The surface crust will support a person on skis or snowshoes, but keep in mind that there are many shallow buried obstacles such as rocks and down trees that could cause significant injury to backcountry travelers.

As of Saturday afternoon, avalanche danger on high elevation north aspects is unlikely from both natural and human triggers. New snowfall and wind beginning Sunday afternoon will increase avalanche danger, especially if poor bonding occurs on the existing, cold surface crust and cold new snow from Wednesday night. Avalanche danger is expected to increase Sunday night into Monday, especially in wind loaded areas on NW-N-NE-E aspects, 35 degrees and steeper. Most avalanches that occur will likely be small, but the potential to be swept over rocks, cliffs, into trees or for burial will exist.

Brandon Schwartz, Avalanche Forecaster

We plan to begin issuing daily avalanche advisories when conditions warrant.


The bottom line:


Andy Anderson - 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:

  Saturday: Saturday Night: Sunday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:

  Saturday: Saturday Night: Sunday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.