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.

Sunny skies will prevail over the forecast area today and tomorrow before the first in a series of storm systems impacts the forecast area starting Wednesday. Ridgetop winds are expected to shift to the south today and begin to increase in speed this afternoon. Winds will shift to the southwest tomorrow and increase to strong in speed ahead of the approaching storm systems. Air temperatures are in the 30s this morning at nearly all elevations, with colder air settled below 6,500'. Maximum daytime air temperatures are expected to reach into the 40s today in most locations. Similar air temperatures are forecast for Tuesday.

Recent Observations:

Observations made yesterday on Silver Peak (Pole Creek area) and on Castle Peak (Donner Summit area) both revealed a stable snowpack. Firm and supportable melt-freeze crust existed on all aspects up to at least 8,300' and significantly higher in more sun exposed areas (photos, pit profiles, more info). The existing snowpack gains usable depth above 7,500' where it is generally 1 to 3 feet deep. Isolated areas of deeper snow have been observed in previously wind loaded areas near ridgelines.

Other recent observations from the Mount Rose and Carson Pass areas have given indications of isolated pockets of persistent snowpack instability. These pockets have been observed above 9,000' on NW-N-NE aspects.  In the Mount Rose area a layer of basal facets has shown persistent instability in snowpit tests. This layer appears weakest on isolated northerly aspects above 9500 ft. that received little to no traffic prior to burial of this layer on November 16th. In the Carson Pass area a lower density layer of snow and associated crust located in the upper 1/3 of the snowpack has shown ongoing instability in snowpit tests. This same layer was a contributing factor in two skier/snowboarder triggered avalanches on November 18th (photos, videos, pit profiles, more info).

Today's Avalanche Concerns:

Avalanche concerns at this time are limited to isolated areas above 9,000' on NW-N-NE aspects where some form of ongoing instability has been observed in recent days. At this time, avalanches are difficult to trigger with the only evidence of slope specific snowpack instability available from snowpit data. Any areas of instability that are encountered will exist within greater surrounding areas of stable snow. Use of accepted backcountry travel techniques will help to minimize risk.

The bottom line:

Avalanche danger is LOW for all elevations and aspects. Very isolated areas of unstable snow may exist above 9,000' on NW-N-NE aspects in complex or extreme terrain.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	34 to 39 deg. F.
Max. temperature in the last 24 hours:	45 to 48 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	16 mph
Maximum wind gust in the last 24 hours:	25 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	12 to 28 inches

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

For 7000-8000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:	Sunny skies.	Clear skies.	Partly cloudy skies.
Temperatures:	43 to 50 deg. F.	27 to 33 deg. F.	42 to 49 deg. F.
Wind direction:	S	SW	SW
Wind speed:	Light in the morning increasing to around 10 mph in the afternoon.	10 to 15 mph with gusts to 25 mph.	15 to 25 mph with gusts to 35 mph.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:	Sunny skies.	Clear skies.	Partly cloudy skies.
Temperatures:	39 to 46 deg. F.	25 to 32 deg. F.	42 to 48 deg. F.
Wind direction:	S	SW	SW
Wind speed:	15 to 20 mph with gusts to 30 mph in the afternoon.	30 to 40 mph with gusts to 55 mph.	30 to 40 mph with gusts to 60 mph.
Expected snowfall:	O in.	O in.	O in.