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 March 7, 2008 7:00 AM
Click here for a detailed map of the SAC forecast area

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Today's Advisory:

The avalanche danger is LOW for all elevations and aspects this morning. Areas of MODERATE danger could develop at all elevations on sun exposed E-SE-S-SW-W aspects, 37 degrees and steeper in response to daytime warming.

Overnight remote sensors along the Sierra Crest and in the Mount Rose indicate that temperatures fell below freezing. They have started to warm up and should reach the mid to upper 40's during today above 8000 ft and the mid 50's below 8000 ft. The forecast calls for more widespread cloud cover and increased winds this afternoon and overnight as a cold front passes to the north of the forecast area.

Yesterday the top 3 to 4 inches of snow softened on southerly aspects. Some radiational cooling and lows below freezing will have allowed this surface snow to refreeze overnight. Today the combination of warmer air temperatures and the March sun should allow more prolonged, widespread, and faster melting. As the snow melts free water will form in the snowpack dissolving bonds between layers and snow grains and weakening the snowpack. The extended melt/freeze cycle has created pathways that drain free water through the snowpack. These channels help prevent free water from saturating layers which would make a layer extremely weak. The repeated melting and refreezing of snow grains helps to eliminate major differences in the layers of the snowpack. Each of these things will help the snowpack adjust to warmer temperatures today. Observations from across the forecast area continue to show a mix of wind affected surfaces, crusts, and unconsolidated snow on the northerly aspects and a well bonded and stable snowpack below the surface layers on all aspects.

Areas of wet snow instability that fail due to human triggering could form during the peak of the melting phase today on steep sun exposed slopes. Afternoon cloud cover, well established drainage channels, a more uniform snowpack, a strong overnight refreeze, and the duration of the current melt/freeze cycle will all help keep natural avalanche activity unlikely today.

The bottom line: The avalanche danger is LOW for all elevations and aspects this morning. Areas of MODERATE danger could develop at all elevations on sun exposed E-SE-S-SW-W aspects, 37 degrees and steeper in response to daytime warming.
Please send us your snow, weather, and avalanche observations by clicking the submit observations link on our contact page.

Thanks to everyone who has donated to the avalanche center this year. We still have not met our fund raising goal for the year, and we need your help to get there. Anyone who donates $100 or more will be entered into a drawing for a BCA backpack, Tracker avalanche beacon, shovel, and probe package worth over $500. Anyone who donates $25 or more will be entered to win a $50 gift certificate to Porters Ski and Snowboard Shop. Winners will be selected on April 1st. Click on the Paypal link at the bottom of the page to donate or here to go to our donations page.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 31 deg. F
Max. temperature at Sierra Crest past 24 hours: 45 deg. F.
Average wind direction at Sierra Crest past 24 hours: Variable
Average wind speed at Sierra Crest past 24 hours: 5 to 10 mph.
Maximum wind gust at Sierra Crest past 24 hours: 22 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 82 inches
Mountain Weather Forecast For Today:
Partly cloudy and warmer with more clouds developing this afternoon.
Temperature forecast for 8,000 to 9,000 feet: 43 to 49 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 10 to 20 mph with gusts to 30 mph.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, partly cloudy this morning becoming mostly cloudy this afternoon. Daytime highs 48 to 54 deg. F. Southwest winds at 10 to 15 mph.

Tonight, mostly cloudy with overnight lows 21 to 31 deg. F. West winds at 10 to 20 mph with gusts to 35 mph.

For Saturday, partly cloudy skies with daytime highs 40 to 45 deg. F. Winds out of the northwest at 10 to 20 mph.

Above 8000 Feet:
Today, partly cloudy this morning becoming mostly cloudy this afternoon. Daytime highs 43 to 49 deg. F. Southwest winds at 10 to 20 mph with gusts to 30 mph.

Tonight, mostly cloudy with overnight lows around 26 deg. F. West winds at 15 to 25 mph with gusts to 60 mph.

For Saturday, partly cloudy skies with daytime highs 30 to 38 deg. F. Winds out of the west at 25 to 35 mph with gusts to 65 in the morning then shifting to the northwest and decreasing to 15 to 25 mph with gusts to 50 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:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.