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 January 24, 2013:


January 24, 2013 at 7:49 am

Avalanche danger remains LOW for all elevations and aspects. Normal caution is advised.


Forecast Discussion:


A weak weather system system brought moisture into the forecast area last night. Light precipitation brought rain and up to 2 inches of new snow to the region. Snow level began as high as 7,800' in some areas last night. Snow level is down to around 6,500' this morning. Precipitation will decrease today as a brief period of high pressure moves into the area for this evening through tomorrow morning. Ridgetop winds were strong out of the southwest yesterday afternoon and last night. Winds have decreased to light to moderate in speed this morning. Light to moderate speed winds out of the south to southwest will continue over the ridges today.

Recent Observations:

Recent observations from around the forecast area have shown a stable snowpack that is generally in good condition to handle loading by new snow and rain. Old snow surface conditions are highly varied ranging from crust on southerly aspects and some ridgetops to wind packed surfaces in most other areas to unconsolidated near surface facets in wind protected areas on N-NE aspects. Isolated areas below 7,600' on wind protected N-NE aspects where near surface facets are highly developed are the only areas of concern for the existence of a weak layer below the old/new snow interface at this time.

Avalanche Problems:

New snow amounts from the past 24 hours were generally insufficient to create any new slab formation of significant size and concern. A newly formed wind slab of sizable concern might exist near or above treeline on a heavily wind loaded NE aspect, but it would be very isolated. Rain on well developed near surface facets is another concern for today, but this too will be limited at best. Low elevation N-NE aspects that were subject to prolonged cold air during the recent period of air temperature inversion hold some areas of weak, somewhat sugary snow at the surface. In areas where rain is deposited on this weak snow,  small loose wet avalanches could occur. The amount of snow involved could be up to 6 inches deep. Areas with terrain traps present the greatest hazard. Traveling steep N-NE aspect creek bed walls below 7,000' is the type of terrain and situation where enough factors could come together to actually bury a person in a loose wet avalanche today.


The bottom line:

Avalanche danger remains LOW for all elevations and aspects. Normal caution is advised.


Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest


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

0600 temperature: 31 to 35 deg. F.
Max. temperature in the last 24 hours: 35 to 42 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 32 mph
Maximum wind gust in the last 24 hours: 68 mph
New snowfall in the last 24 hours: Up to 2 inches
Total snow depth: 56 to 83 inches

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

For 7000-8000 ft:

  Thursday: Thursday Night: Friday:
Weather: Cloudy skies with scattered snow showers in the morning. Isolated snow showers in the afternoon. Mostly cloudy skies. Mostly cloudy skies with a slight chance of showers.
Temperatures: 35 to 42 deg. F. 28 to 32 deg. F. 33 to 40 deg. F.
Wind direction: SW S SW
Wind speed: Up to 10 mph in the morning, becoming light. Light winds. Light winds up to 10 mph in the afternoon.
Expected snowfall: Up to 1 in. O in. 0 to trace in.

For 8000-9000 ft:

  Thursday: Thursday Night: Friday:
Weather: Cloudy skies with scattered snow showers in the morning. Isolated snow showers in the afternoon. Mostly cloudy skies. Mostly cloudy skies with a slight chance of showers.
Temperatures: 33 to 40 deg. F. 25 to 32 deg. F. 33 to 39 deg. F.
Wind direction: SW S SW
Wind speed: 10 to 15 mph with gusts to 25 mph. 10 to 15 mph with gusts to 25 mph. 10 to 15 mph. Gusts to 25 mph in the afternoon.
Expected snowfall: Up to 1 in. O in. 0 to trace in.