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 February 20, 2008 7:05 AM
Click here for a detailed map of the SAC forecast area

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Today's Advisory:

Near and above treeline, avalanche danger is MODERATE on wind loaded N-NE-E aspects, 37 degrees and steeper. Below treeline, avalanche danger is LOW.

A weak weather system is affecting the forecast area this morning. A few inches of snowfall and light winds have occurred overnight. Remote sensors are reporting 3 to 5 inches of new snow along the Sierra Crest. New snowfall amounts in the Mount Rose area are unknown this morning. Ridgetop winds have been from the southwest for the past 24 hours and are beginning to shift to the west this morning. Winds are expected to shift to the northwest and remain light today. Light snowfall is expected to continue into this afternoon with an additional 3 to 6 inches of accumulation possible today above 8,000'.

The existing snowpack is in excellent condition to handle new snow loading. N-NE-E aspects above treeline have a wind affected old snow surface in nearly all areas. New snow is expected to bond well to this old snow surface. Ridgetop winds have been light with this system, but still strong enough to transport snow over ridgelines. Any instability that occurs today is expected in the most heavily wind loaded areas. Shallow slabs in these areas will likely fail within the new snow, near or above the old/new snow interface. On southerly aspects, new snow is falling on a frozen crust surface. Some shallow loose snow instability is possible on cross loaded SE aspects in response to human triggering.

Human triggered avalanches are possible today in wind loaded areas on steep N-NE-E aspects near and above treeline. Below treeline, human triggered avalanches are unlikely today. Natural avalanches are unlikely today in all areas.

The bottom line: Near and above treeline, avalanche danger is MODERATE on wind loaded N-NE-E aspects, 37 degrees and steeper. Below treeline, avalanche danger is 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): 19 deg. F
Max. temperature at Sierra Crest past 24 hours: 34 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 24 mph
Maximum wind gust at Sierra Crest past 24 hours: 41 mph
New snow fall at 8,200 feet past 24 hours: 3 to 5 inches
Total snow depth at 8,200 feet: 82 inches

Mountain Weather Forecast For Today:
Cloudy with snow showers, decreasing in the afternoon.
Temperature forecast for 8,000 to 9,000 feet: 20 to 28 deg. F
Ridgetop winds forecast for the Sierra Crest: Northwest at 10 to 15 mph with gusts to 30 mph
Snowfall expected in the next 24 hours: 3 to 6 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, cloudy with snow showers in the morning, decreasing in the afternoon. Daytime highs 29 to 35 deg. F. Light winds becoming northwest winds at 10 mph in the afternoon.

Tonight, mostly cloudy skies with overnight lows around 19 deg. F. West winds at 10 mph in the evening, becoming light.

For Thursday, mostly cloudy with a slight chance of snow in the morning. Snow likely in the afternoon. Snow accumulation up to 2 inches. Daytime highs around 36 deg. F. Southwest winds at 10 to 15 mph with gusts to 30 mph in the afternoon.

Above 8000 Feet:
Today, cloudy with snow showers in the morning, decreasing in the afternoon. Daytime highs 20 to 28 deg. F. Northwest winds at 10 to 15 mph with gusts to 30 mph.

Tonight, mostly cloudy skies with overnight lows 15 to 21 deg. F. West winds up to 10 mph.

For Thursday, mostly cloudy with a slight chance of snow in the morning. Snow likely in the afternoon. Snow accumulation up to 2 inches. Daytime highs around 31 deg. F. Southwest winds at 10 to 20 mph with gusts to 25 mph. Gusts increasing to 35 mph in the 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:
	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.