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 21, 2008 6:44 AM

A map of the SAC forecast area is available on our home page.

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Today's Advisory:
This morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE danger will develop on sun exposed E-SE-S-SW-W aspects, 38 degrees and steeper in response to daytime warming.

High pressure is moving into the forecast area this morning. Air temperatures at all elevations are below freezing. Ridgetop winds have remained moderate speed from the west for the past 24 hours. Winds are expected to decrease to light by this afternoon.

Yesterday, observations made on Mt. Judah (Donner Summit area) showed fair bonding of around 3 inches of new snow to a melt-freeze old snow surface on all aspects. Evidence of a small skier triggered soft slab avalanche was observed to have occurred prior to 10 am in the most heavily wind loaded pocket just below the ridgeline. The small avalanche occurred above treeline at 8,200' on a an approximately 40 degree NE aspect. The shallow slab failed on a crusted old snow bed surface and the avalanche was not large enough to bury or injure a person (D1). The crown measured 3 to 8 inches high and 30 feet wide. Debris ran 40 feet down slope. A skier triggered wet snow sluff involving 3 inches of new snow on top of a melt-freeze crust was observed at 8,000' on a E aspect around noon. No other avalanche activity or test slope failure was observed on other steep and wind loaded slopes in the area. No other avalanche activity was reported from the rest of the forecast area. Improved bonding at the old/new snow interface is expected to have occurred overnight, making continued dry slab avalanche activity unlikely.

Today, melting of surface snow is expected in sun exposed areas. This will have the greatest impact on E-SE-S-SW-W aspects below 9,000'. Some natural and human triggered roller ball activity is expected to continue in areas where recent new snow has accumulated. Wet snow instability that occurs today is expected to involve only surface snow. In areas north of Hwy 50, this will likely consist of recent new snow. South of Hwy 50, wet snow will form from the melting of old snow surfaces. Human triggered avalanches will become possible today as daytime warming occurs. Wet snow instability involving recent new snow will occur earlier in the day. Wet snow instability involving old snow surfaces will occur later in the day. Natural avalanche activity is unlikely at this time.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE danger will develop on sun exposed E-SE-S-SW-W aspects, 38 degrees and steeper in response to daytime warming.

Public donations to the avalanche center this season are below our fundraising goal. We are going to raffle a beacon, shovel, probe, and backpack package as a way give back to those who donate $100 or more before March 30th. For more information on the raffle and amount of donations received click here.

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: 28 to 38 deg. F.
Average wind direction at Sierra Crest past 24 hours: West
Average wind speed at Sierra Crest past 24 hours: 35 mph
Maximum wind gust at Sierra Crest past 24 hours: 66 mph
New snowfall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 84 inches

Mountain Weather Forecast For Today:
Mostly sunny skies.
Temperature forecast for 8,000 to 9,000 feet: 34 to 40 deg. F
Ridgetop winds forecast for the Sierra Crest: West at 10 to 15 mph with gusts to 30 mph in the morning, becoming light.
Snowfall expected in the next 24 hours: 0 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, mostly sunny skies with daytime highs around 45 deg. F. West winds around 10 mph in the morning, becoming light.

Tonight, mostly clear skies with overnight lows around 22 deg. F. Northeast winds at 10 to 15 mph with gusts to 25 mph after midnight.

For Saturday, sunny skies with daytime highs around 51 deg. F. East winds around 10 mph.

Above 8000 Feet:
Today, mostly sunny skies with daytime highs 34 to 41 deg. F. West winds at 10 to 15 mph with gusts to 30 mph in the morning, becoming light.

Tonight, mostly clear skies with overnight lows 18 to 24 deg. F. Northeast winds at 10 to 15 mph with gusts to 25 mph after midnight.

For Saturday, sunny skies with daytime highs 39 to 45 deg. F. East winds at 10 to 15 mph with gusts to 25 mph.

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.