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 February 2, 2013:


February 2, 2013 at 8:00 am

The avalanche danger remains LOW for all elevations and aspects. Continue to use normal caution when travelling in the backcountry.


Forecast Discussion:


The high pressure ridge over the region should keep the weather dry, warm, and calm. Some high clouds could move over the area today and linger through tomorrow. The forecast also calls for slightly increased SW winds that average between 10 and 15 mph through tomorrow. The spring-like weather should continue through the weekend.

Recent Observations:

2-5 inches of soft corn snow had formed on the SE-S-SW aspects by mid day yesterday on Red Lake Peak (photos, more info), Rose Knob Peak, and in the Donner Summit area (photos, more info). This soft, wet corn snow rested on top of a supportable melt-freeze crust. Above 9400 ft on Red Lake Peak, the spring snow conditions gave way to frozen crusts and wind packed snow (photo). Ski cuts, hand pits, and general observations did not reveal signs of significant wet snow instabilities on the soft southerly aspects. The more northerly aspects held scoured surfaces, wind packed snow, and frozen crusts in these three areas yesterday (photos from Donner Summit and Red Lake Peak). A few of the older harder wind slabs still remained on the upper elevation SE aspects on Red Lake Peak. Ski cuts and ski kicks on test slopes with these wind slabs did not result in any cracking or collapsing.

Avalanche Concerns:

Avalanche activity will remain unlikely on a regional scale today. Some small wet loose snow instabilities such as roller balls, pin wheels, or small point releases may form on the most sun exposed southerly aspects in the afternoon. Hard wind slabs do still remain on high elevation SE-S-SW-W aspects. Triggering these wind slabs has become unlikely and will continue to become more difficult as the spring-like weather persists. In the unlikely event that a person triggers either of these kinds of avalanches, neither of them should involve enough snow to bury a person. However, small amounts of moving snow can push a person off course or off his/her feet resulting in other consequences.


The bottom line:

The avalanche danger remains LOW for all elevations and aspects. Continue to use normal caution when travelling in the backcountry.


Andy Anderson - Avalanche Forecaster, Tahoe National Forest


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

0600 temperature: 30-38 deg. F.
Max. temperature in the last 24 hours: 46-49 deg. F.
Average wind direction during the last 24 hours: East to Southwest
Average wind speed during the last 24 hours: 5 mph
Maximum wind gust in the last 24 hours: 21 mph
New snowfall in the last 24 hours: O inches
Total snow depth: 55-81 inches

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

For 7000-8000 ft:

  Saturday: Saturday Night: Sunday:
Weather: Partly cloudy to mostly cloudy Partly cloudy Mostly sunny with some high clouds
Temperatures: 38-45 deg. F. 20-28 deg. F. 38-45 deg. F.
Wind direction: Variable Variable Variable
Wind speed: Light Light Light
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:

  Saturday: Saturday Night: Sunday:
Weather: Partly cloudy to mostly cloudy Partly cloudy Mostly sunny with some high clouds
Temperatures: 39-45 deg. F. 18-25 deg. F. 39-45 deg. F.
Wind direction: Southwest Southwest West
Wind speed: 10-15 mph with gusts to 25 mph in the afternoon 10-15 mph with gusts to 25 mph after midnight 10-15 mph with gusts up to 25 mph in the morning
Expected snowfall: O in. O in. O in.