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.

The high pressure ridge will remain over the forecast area bringing continued dry and mostly clear weather to the region. Today some cloud cover should develop due to a low pressure east of the forecast area. The northeasterly winds should also continue and should increase today and remain strong through the next 24 hours.

Observations:

Yesterday observations from Trimmer Peak revealed variable and disconnected wind slabs on NW-N aspects between 8500 ft and 9100 ft. These fragile slabs did not represent a threat to backcountry travelers in this area due to their lack of continuity and their overall size (photos and more info). The consolidation of the recent storm snow combined with just enough exposure to the northeast winds seems to be allowing these small slabs to become slightly more reactive. On Castle Peak observations showed a mix of hard to very hard scoured surfaces on aspects exposed to the east and northeast winds near and above treeline. On SE-S aspects snow surface conditions varied greatly ranging from soft snow to wet sticky snow to wind scoured surfaces in this area (photos). On both Castle and Trimmer several inches of soft snow with a crust below it remained on the northerly aspects sheltered from the east and northeast winds in below treeline areas.

Primary Avalanche Concern: Wind Slabs

Previous east and northeast winds scoured most of the exposed N-NE-E aspects back to the frozen crusts that existed before the storm leaving very little snow available for transport by last night's and today's increased northeast winds. Without snow to transport, new wind slab formation by these increased winds will remain very limited. However, these winds could help stiffen the recent snow allowing it to gain strength faster than the bonds holding it to the snow below. Areas where this process occurs and human-triggered avalanche activity becomes possible should remain very isolated due to the numerous factors required to create these specific conditions. These factors include just enough wind loading from the SW winds during the storm, enough east winds to stiffen this slab but not enough to scour it away, an area large enough to allow for a slightly more continuous slab, and enough of a northerly aspect to keep the bonds from strengthening too fast. Steep NW-N-NE aspects near treeline in complex terrain may hold very isolated pockets where these complex wind slabs could push someone into a terrain trap or obstacle.

The bottom line:

LOW avalanche danger exists on most aspects and elevations. Some very isolated pockets of MODERATE danger may exist on NW-N-NE aspects, 37 degrees and steeper near treeline.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	27 deg. F.
Max. temperature in the last 24 hours:	32-40 deg. F.
Average wind direction during the last 24 hours:	Northeast
Average wind speed during the last 24 hours:	25-40 mph
Maximum wind gust in the last 24 hours:	73 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	60-89 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy	Clear	Sunny
Temperatures:	40-47 deg. F.	25-33 deg. F.	37-44 deg. F.
Wind direction:	Northeast	Northeast	Northeast
Wind speed:	10-20 mph with gusts to 50 mph	10-15 mph with gusts to 40 mph	10-15 mph with gusts to 40 mph increasing to 50 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy	Clear	Sunny
Temperatures:	32-42 deg. F.	27-33 deg. F.	32-39 deg. F.
Wind direction:	Northeast	Northeast	Northeast
Wind speed:	25-40 mph with gusts to 60 mph decreasing to 50 mph in the afternoon	25-40 mph with gusts to 55 mph decreasing to 45 mph after midnight	25-35 mph with gusts to 50 mph increasing to 35-45 mph with gusts to 60 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.