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 December 26, 2007 6:47 AM
Click here for a detailed map of the SAC forecast area

low avalanche danger
Today's Advisory:
This morning, avalanche danger is LOW for all elevations and aspects. By this afternoon, some very isolated pockets of MODERATE danger may develop near and above treeline on wind loaded NE-E-SE aspects, 35 degrees and steeper. Below treeline, avalanche danger will remain LOW.

A cold air mass is on track to move into the forecast area today. It is expected cause light to moderate snowfall rates, spreading from north to south across the area as the day progresses. New snowfall amounts of up to 3 inches are possible today. Wind chill is expected to drop to -15 to -25 deg. F. by late afternoon above 8,000'. Ridgetop winds have shifted from east to west ahead of the approaching weather system.

A stable snowpack exists throughout the forecast area at this time. Stability tests have shown that layer bond strength has continued to improve over the past few days under the influence of warmer air temperatures. The lurking basal layer of faceted snow crystals has not been reported to contribute to any avalanche activity since 12/22.

Depending on actual new snowfall amounts this afternoon, formation of some very isolated pockets of instability may occur. Any instability that forms is expected to limit to small shallow slabs of new snow in near and above treeline areas. Any newly formed slabs will be found in the most heavily wind loaded areas on NE-E-SE aspects.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. By this afternoon, some very isolated pockets of MODERATE danger may develop near and above treeline on wind loaded NE-E-SE aspects, 35 degrees and steeper. Below treeline, avalanche danger will remain LOW.

Please send us your snow, weather, and avalanche observations by clicking the submit observations link on our contact page.

Brandon Schwartz, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 14 deg. F
Max. temperature at Sierra Crest past 24 hours: 30 deg. F
Average wind direction at Sierra Crest past 24 hours: East shifting to west
Average wind speed at Sierra Crest past 24 hours: 33 mph
Maximum wind gust at Sierra Crest past 24 hours: 69 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 31 inches

Mountain Weather Forecast For Today:
Cloudy skies with snow showers.
Temperature forecast for 8,000 to 9,000 feet: 12 to 17 deg. F in the morning, dropping to 0 to 5 deg. F. this afternoon.
Ridgetop winds forecast for the Sierra Crest: West at 25 to 40 mph with gusts to 55 mph, shifting to the northwest at 20 to 30 mph with gusts to 45 mph in the afternoon.
Snowfall expected in the next 24 hours: 1 to 3 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:

Today, cloudy skies with snow showers, increasing in the afternoon. Snow accumulation up to 3 inches. Daytime highs 22 to 27 deg. F. in the morning, falling to 10 to 15 deg. F in the afternoon. West winds at 15 to 25 mph shifting to the northwest at 15 to 20 mph in the afternoon.

Tonight, mostly cloudy skies with scattered snow showers in the evening. Overnight lows 4 to 10 deg. F. Northeast winds at 10 to 15 mph.

For Thursday, mostly cloudy skies with a slight chance of snow in the afternoon. Daytime highs 23 to 29 deg. F. Southeast winds at 5 to 10 mph, shifting to southwest in the afternoon.

Above 8000 Feet:

Today, cloudy skies with snow showers, increasing in the afternoon. Snow accumulation up to 3 inches. Daytime highs 12 to 17 deg. F. in the morning, falling to 0 to 5 deg. F in the afternoon. West winds at 25 to 40 mph with gust to 55 mph. Winds shifting to the northwest at 20 to 30 mph with gust to 45 mph in the afternoon.

Tonight, mostly cloudy skies with scattered snow showers in the evening. Overnight lows 0 to 5 deg. F. Northeast winds at 20 to 30 mph with gust to 45 mph.

For Thursday, mostly cloudy skies with a slight chance of snow in the afternoon. Daytime highs 15 to 25 deg. F. South winds at 10 to 15 mph, shifting to west at 15 to 25 mph with gust to 45 mph in the afternoon are expected.

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:
	Wednesday:	Wednesday Night:	Thursday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.