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.

High pressure is in place over the forecast area. An air temperature inversion is in place once again this morning, with the coldest air below around 7,000'. Ridgetop wind remain out of the NE this morning. Winds are expected to remain moderate in speed through this afternoon before decreasing overnight. For Friday, morning air temperature inversion and light winds are expected.

Yesterday observations made on Carpenter Ridge (Independence Lake area) near treeline at 8,400' on a NE aspect continued to show that the October 19 facet layer that exists near the bottom of the snowpack is still a weak layer in some areas (video). Observations made on Incline Lake Peak (Mount Rose area) below treeline at 9,280' on a NE aspect revealed a stable snowpack and the absence of the Oct 19 facet layer in that location (video). The recent trend in observations has been very stable snow in some areas and unlikely, but still lingering deep slab possibilities in other locations (view all observations on a map).

The small shallow slabs that formed from recent NE winds on SE-S-SW-W aspects above treeline are expected to have stabilized and no longer present a concern. Today's concerns for unlikely human triggered avalanche activity remain focused on deep slab instability associated with the Oct 19 facet layer. This layer lives on many NW-N-NE aspects above 8,000' in near treeline and below treeline areas that receive some protection from NE winds. From the standpoint of skiing, snowboarding, and snowmobiling, it has become very difficult to initiate failure of this weak layer due to the strength of the snow above it. In the unlikely event that an avalanche is triggered, a destructive hard slab avalanche with a slab thickness of 2 to 4+ feet would likely occur. For this reason, continued caution in the backcountry is advised.

The bottom line:

Avalanche danger is LOW for all elevations and aspects. Normal caution is advised. Deep slab instability is unlikely but not impossible near treeline and below treeline on NW-N-NE aspects above 8,000' at this time. The next scheduled update to this advisory will occur Dec 26 at 7am.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	20 deg. F.
Max. temperature in the last 24 hours:	24 to 36 deg. F.
Average wind direction during the last 24 hours:	Northeast
Average wind speed during the last 24 hours:	45 mph
Maximum wind gust in the last 24 hours:	72 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	34 to 55 inches

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

For 7000-8000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:	Sunny skies in the morning, becoming partly cloudy.	Clear skies.	Partly cloudy skies.
Temperatures:	32 to 39 deg. F.	13 to 19 deg. F.	34 to 41 deg. F.
Wind direction:	NE shifting to E	E	Variable
Wind speed:	Around 10 mph.	Around 10 mph in the evening, becoming light.	Light winds
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:	Sunny skies in the morning, becoming partly cloudy.	Clear skies.	Partly cloudy skies.
Temperatures:	31 to 38 deg. F.	13 to 20 deg. F.	32 to 39 deg. F.
Wind direction:	NE shifting to E	E	Variable
Wind speed:	10 to 15 mph with gusts to 40 mph.	Around 10 mph in the evening, becoming light.	Light winds
Expected snowfall:	O in.	O in.	O in.