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.

This advisory was posted on Sunday, December 24, 2006 at 6:40 am

Ridgetop winds remained westerly yesterday and were strong enough to move snow over ridges, depositing it onto lee slopes. The approaching storm system that is expected to bring heavy precipitation in the form of rain and snow to the forecast area has slowed down a bit and is now expected to arrive on Monday. Air temperatures will remain warm today and tomorrow before cold front passage associated with the approaching storm system occurs, possibly late Tuesday.

Moderate westerly ridgetop winds created wind loading on NW-N-NE-E aspects during the day yesterday. A brief period of rain and snow created up to one inch of new snow accumulation. Small pockets of wind slab were deposited in the most heavily wind loaded areas on N-NE-E aspects. Ridgetop winds have become calm overnight, but are expected to increase from the southwest as the day progresses. Most of the snow that was available for wind transport was taken from the windward aspects yesterday, leaving little to no available snow for wind transport today. Very isolated pockets of shallow wind slab still linger on N-NE-E aspects today. Small human triggered avalanches remain possible in very isolated areas near and above treeline. In wind protected areas, an additional inch of settlement was observed over the past 24 hours as the snowpack continues to bond and gain strength. Cold, unconsolidated snow remains on sheltered northerly aspects, especially at the higher elevations.

Near and above treeline, avalanche danger for most areas is LOW. Some very isolated pockets of MODERATE danger linger on recently wind loaded N-NE-E aspects 35 degrees and steeper. Below treeline, avalanche danger remains LOW.

Brandon Schwartz, Avalanche Forecaster

Today's Central Sierra Weather Observations:

0600 temperature at Sierra Crest (8,700 feet): 26 deg. F
Max. temperature at Sierra Crest past 24 hours: 33 deg. F
Average wind direction at Sierra Crest past 24 hours: westerly
Average wind speed at Sierra Crest past 24 hours: 28 mph
Maximum wind gust at Sierra Crest past 24 hours: 57 mph
New snow fall at 8,200 feet past 24 hours: trace - 1 inch
Total snow depth at 8,200 feet: 33 inches

Mountain Weather Forecast For Today:

Mostly cloudy skies
Temperature forecast for 8,000 to 9,000 feet: 36 - 42 deg. F
Ridgetop winds forecast for the Sierra Crest: southwesterly 20 - 30 mph, G 50 mph
Snowfall expected in the next 24 hours: 0 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet
For today, mostly cloudy skies with daytime highs 40 to 45 degrees F. Winds out of the west at 15 to 25 mph with gusts to 35 mph. Overnight lows 25 to 34 degrees F under mostly cloudy skies. Southwesterly winds 25 to 40 mph with gusts to 70 mph after midnight. Monday will be mostly cloudy with a chance of rain and snow. Snow level 7,000' to 7,500'. Snow accumulation up to 2 inches. Daytime highs 40 to 46 degrees F. Southwesterly winds 35 to 40 mph with gusts to 70 mph are expected Monday afternoon.

Above 8000 Feet
For today, mostly cloudy skies with daytime highs 36 to 42 degrees F. Winds out of the west at 20 to 30 mph with gusts to 50 mph. Overnight lows 25 to 31 degrees F. Southwesterly winds 30 to 50 mph with gusts to 90 mph after midnight. Monday will be mostly cloudy with a snow likely by afternoon. Snow accumulation up to 2 inches. Daytime highs around 38 to 44 degrees F. Southwesterly ridgetop winds 45 to 60 mph with gusts to 90 mph are expected Monday afternoon.

The bottom line:

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	deg. F.
Max. temperature in the last 24 hours:	deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours:	mph
Maximum wind gust in the last 24 hours:	mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	inches

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

For 7000-8000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.