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 low-pressure system should start to impact the forecast area today. The forecast calls for the strongest part of the storm to pass south of the region; however, it should bring cooler temperatures, cloudy skies, and some snow to the Tahoe area over the next 24 hours. The heaviest snowfall should fall overnight tonight before tapering off to showers during the day tomorrow. The forecast calls for a total of 3-8 inches by tomorrow afternoon. Southwest winds should remain moderate during this storm. Click here for more detail and weather graphics from the NWS.

Observations:

Yesterday cooler temperatures and moderate winds kept the snow surface from melting as much as it has during previous days. A few small, skier-triggered roller balls and wet-snow sluffs did occur on 35-40-degree, S-SE-facing slopes below 8000' on Castle Peak yesterday (photos). These wet-snow instabilities did not move enough snow to pose much of a threat to backcountry travelers. They also remained confined to small isolated pockets of terrain. Near Incline Lake Peak in the Mt. Rose backcountry only a few small roller balls occurred near rock outcrops. In both areas 2-4 inches of wet snow existed on the SE-S-SW aspects by midday with a supportable, frozen surface below the wet snow. On the northerly aspects a mix of soft snow, breakable crusts, wind-crusts, and firm conditions existed in both areas. The sheltered northerly aspects above 8000' held the most consistent soft snow. Snowpit observations did show a thin layer of weak snow on the northerly aspects below some of the surface crusts in both areas.

Avalanche Concerns:

A solid overnight refreeze, cooler daytime temperatures, less sun, and more snowpack consolidation will all work together to keep avalanche activity unlikely today. As more snow and wind impact the forecast area over the next 24 hours, new slabs will form on top of the old snow surfaces mentioned above. This new snow and wind will cause the avalanche danger to increase during the next 24hrs. How much the danger increases will depend on how much new snow actually falls and how well it bonds to those old snow surfaces.

The bottom line:

The avalanche danger will remain LOW for all elevations and aspects today. Expect the avalanche danger to increase over the 24 hours as a storm impacts the Central Sierra.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	24 deg. F.
Max. temperature in the last 24 hours:	39 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	20-25 mph
Maximum wind gust in the last 24 hours:	46 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	66-103 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy this morning becoming cloudy with a 30% chance of snow showers this afternoon.	Snow likely	Cloudy with a 50% chance of snow showers.
Temperatures:	33-40 deg. F.	18-25 deg. F.	29-36 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	10-15 mph with gusts to 25 mph	10 mph with gusts to 25 mph after midnight	10-20 mph with gusts to 30 mph
Expected snowfall:	trace in.	3-5 in.	up to 1 in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy this morning becoming cloudy with a 30% chance of snow showers this afternoon.	Snow likely	Cloudy with a 50% chance of snow showers.
Temperatures:	30-37 deg. F.	14-21 deg. F.	27-33 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	15-20 mph with gusts to 30 mph	10-20 mph with gusts to 30 mph	15-25 mph with gusts to 35 mph increasing to 45 mph in the afternoon
Expected snowfall:	trace in.	3-6 in.	up to 2 in.