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 6, 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 the northeast winds decreased and temperatures started to warm above 7500 ft. Remote sensors along the Sierra Crest and in the Mount Rose area reported temperatures 10 to 20 degrees higher than yesterday at 6am. The forecast calls for this warming trend to continue today with daytime highs reaching the mid 40's above 8000 ft and the upper 40's to low 50's below 8000 ft today. Some thin, high clouds should build over the forecast area this afternoon.

Observations from Freel Peak and Poison Canyon (Bear Valley area) yesterday continue to show a mix of wind affected surfaces, crusts, and unconsolidated snow on the northerly aspects and melt/freeze conditions on southerly aspects. Only the top few inches of snow melted on southerly aspects above 8000 ft. yesterday. Once the melted surfaces lost direct sunlight, they quickly refroze making the melting phase of the melt/freeze cycle short. The freezing phase has been dominate for the last 36 hours due to lower daytime temperatures, extended periods of below freezing temperatures, and radiational cooling of the snowpack. Today the combination of warmer air temperatures and the March sun should allow more prolonged and widespread melting. As the snow melts free water will form in the snowpack dissolving bonds between layers and snow grains and weakening the snowpack until it refreezes. Hasty pits and layer bonding tests showed a well bonded and stable snowpack below the surface layers on all aspects yesterday.

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. Some afternoon cloud cover, the strong 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. 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): 33 deg. F
Max. temperature at Sierra Crest past 24 hours: 33 deg. F.
Average wind direction at Sierra Crest past 24 hours: Northeast
Average wind speed at Sierra Crest past 24 hours: 30 mph then decreasing to 12 mph after 6 pm yesterday.
Maximum wind gust at Sierra Crest past 24 hours: 63 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 83 inches
Mountain Weather Forecast For Today:
Sunny and warmer with some thin high clouds developing this afternoon.
Temperature forecast for 8,000 to 9,000 feet: 35 to 45 deg. F
Ridgetop winds forecast for the Sierra Crest: Northeast to east at 5 to 15 mph.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, sunny skies with daytime highs 40 to 47 deg. F. and light winds.

Tonight, clear skies with overnight lows 21 to 31 deg. F. and light winds.

For Friday, sunny skies with daytime highs 43 to 50 deg. F. Winds out of the southwest and increasing to 5 to 15 mph in the afternoon.

Above 8000 Feet:
Today, sunny skies with daytime highs 35 to 45 deg. F. Northeast to east winds at 5 to 15 mph.

Tonight, clear skies with overnight lows 20 to 30 deg. F. and light winds.

For Friday, sunny skies with daytime highs 38 to 45 deg. F. Winds out of the southwest and increasing to 10 to 15 mph with gusts to 30 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:
	Thursday:	Thursday Night:	Friday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.