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.

A small system north of the region has pushed some clouds into the forecast area. This system also brought a light west to northwest wind for last night and today. The clouds should dissipate this evening leaving clear skies and slight east winds behind. The high pressure ridge over the area should allow temperatures to continue warming with today's highs in the mid 30's to mid 40's above 7000 ft. With more sunshine forecast for tomorrow temperatures should climb into the mid to upper 40's in the mountains.

Recent Observations:

Observations on Becker Peak yesterday, did not indicate the same weakening trend as those from Donner Peak on Tuesday. In fact data showed the opposite: the snowpack seems to be gaining strength in the Becker Peak area (snowpit and more info). Ski cuts on and aggressively weighting those isolated test slopes where wind slabs did exist did not produce any signs of instability. Snowpit data and tests consistently indicated that if fractures do start in the observed weak layers, they should not travel far enough to result in an avalanche. This data matches most of the other data collected this week far better than the information gathered from Donner Peak on Tuesday.  On the near treeline exposed terrain between Becker Peak and Talking Mtn, wind scoured surfaces with a few isolated pockets of small hard wind slabs existed on all aspects. On the more sheltered lower elevation slopes on all aspects snowpit data and other tests also did not reveal any signs of instability. On the northerly aspects soft unconsolidated snow resting above an eroding crust existed. On the sun exposed southerly aspects a thin layer of wet snow that had not quite transitioned to corn had formed on the surface.

Avalanche Problem #1: Wind Slabs

Isolated, sporadic, and small hard wind slabs still exist in a few places near ridgelines in near and above treeline terrain. These wind slabs do not extend very far down slope due to a combination of a lack of snow available to construct larger slabs and significant wind scouring. A great deal of variability exists concerning the location, thickness, and size of these slabs. Variability also surrounds the stability of these slabs. Most data has indicated that they are very difficult for a single person to trigger, and that they are becoming more stable as time passes. Triggering one of these slabs is unlikely in most areas. However, finding an isolated pocket of terrain with a slope or two where one could trigger these wind slabs is not impossible. Wind loaded or cross loaded complex or extreme near and above treeline terrain along the Sierra Crest represents the best terrain to find one of these very isolated pockets of more fragile wind slabs.

The bottom line:

On a regional scale the avalanche danger remains LOW for all elevations and aspects. While finding a small isolated unstable wind slab is unlikely, it is not impossible today in a few scattered places in near treeline or above treeline terrain. Continue to use normal caution when traveling 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:	24-31 deg. F.
Max. temperature in the last 24 hours:	34-41 deg. F.
Average wind direction during the last 24 hours:	West southwest to northwest
Average wind speed during the last 24 hours:	10-15 mph
Maximum wind gust in the last 24 hours:	39 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	55-80 inches

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

For 7000-8000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:	Partly cloudy	Partly cloudy becoming clear overnight	Sunny
Temperatures:	38-45 deg. F.	20-30 deg. F.	44-51 deg. F.
Wind direction:	West	Variable	East
Wind speed:	5-15 mph	Light	5-15 mph
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:	Partly cloudy	Partly cloudy becoming clear overnight	Sunny
Temperatures:	32-42 deg. F.	20-27 deg. F.	35-45 deg. F.
Wind direction:	West	East	East
Wind speed:	15-25 mph with gusts to 35 mph	5-15 mph	10-20 mph with gusts to 30 mph
Expected snowfall:	O in.	O in.	O in.