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 and slightly warmer air temperatures are on tap for today as the axis of high pressure shifts to the east. An air temperature inversion is in place again this morning, but not nearly as strong as yesterday morning. Ridgetop winds remain out of the east and are light in speed. Winds are forecast the remain light through the day, eventually shifting to the southwest this evening. Maximum daytime air temperatures in the mid 30s to mid 40s are expected today for nearly all elevations. Partly cloudy skies, light to moderate southwest winds, and a continued warming trend are expected for tomorrow.

Observations:

Observations from around the forecast area over the past two weeks all tell the same story. The snowpack on NW-N-NE-E aspects is shallow, weak, and wind affected. Significant amounts of faceted snow exist in nearly all areas with varying degrees of overlying slab. In the vast majority of areas, the overlying slab is either too faceted and weak to propagate or it is sufficiently anchored. Recent east wind events have scoured significant amounts of snow from near and above treeline avalanche start zones. What was left behind is either bare ground or stable hard slabs. The SE-S-SW-W aspects are generally void of snow or hold just a few inches in shaded areas.

Avalanche Concerns: Persistent slabs

Despite widespread weak layers in the existing snowpack, the necessary ingredients for avalanche activity are hard to find all at once in the same location. Finding a faceted weak layer is easy, but finding a slab above it that is both unanchored and has the necessary characteristics to propagate is difficult. Steep northerly aspects with few visible anchors remain the suspect areas. Evaluating suspect areas on a slope by slope basis remains prudent at this time. Any evidence of instability should be weighted heavily in the decision make process. Given the current conditions, evidence of instability is unlikely to be seen outside of a snowpit or the aftermath of a human triggered avalanche. Exercise normal caution when traveling in the the backcountry as any human triggered avalanche activity at this time will occur within surrounding areas of stable snow.

The bottom line:

Avalanche danger remains LOW for all elevations and aspects. Normal caution is advised. The next update to this advisory will occur on December 26th at 7am.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	24 to 28 deg. F.
Max. temperature in the last 24 hours:	35 to 40 deg. F.
Average wind direction during the last 24 hours:	East
Average wind speed during the last 24 hours:	19 mph
Maximum wind gust in the last 24 hours:	41 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	4 to 20 inches

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

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Sunny skies.	Clear skies.	Partly cloudy skies.
Temperatures:	36 to 43 deg. F.	19 to 27 deg. F.	39 to 46 deg. F.
Wind direction:	E	SW	SW
Wind speed:	Around 10 mph.	Light winds increasing to around 10 mph with gusts to 30 mph after midnight.	10 to 15 mph with gusts to 30 mph.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Sunny skies.	Clear skies.	Partly cloudy skies.
Temperatures:	35 to 42 deg. F.	24 to 30 deg. F.	39 to 45 deg. F.
Wind direction:	E	SW	SW
Wind speed:	10 to 15 mph with gusts up to 25 mph in the morning.	10 to 20 mph with gusts to 30 mph.	15 to 25 mph with gusts to 40 mph.
Expected snowfall:	O in.	O in.	O in.