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 Monday, March 26th, 2007 at 6:59 am

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. After the onset of precipitation this afternoon, avalanche danger will rise to MODERATE near and above treeline on wind loaded N-NE-E aspects 35 degrees and steeper. Avalanche danger will continue to rise during the overnight hours with natural avalanches becoming possible as snowfall continues.

A modest weather system is approaching the forecast area this morning. Increasing cloud cover is expected this morning with the onset of precipitation forecast to occur around noon today. Ridgetop winds out of the westsouthwest are increasing in speed this morning and are expected to become strong as the day progresses. Air temperatures will decrease this afternoon. Snow level is expected to begin around 7,000', rapidly lowering to around 5,500' this afternoon. Snow level is expected to continue to lower to around 3,000' overnight. New snow accumulation of 8-12 inches is possible above 7,000' by Tuesday morning.

Last night, air temperatures above 8,000' fell below freezing for a few hours. Light cloud cover with partial clearing early this morning allowed for radiational cooling to refreeze the snow surface in all areas. As air temperatures fall this afternoon, the existing snowpack will continue to refreeze and become strong. Any avalanche activity that occurs during the next 24 hours is expected to involve only new snow.

As new snow begins to accumulate this afternoon, possibility of human triggered avalanches will increase. The areas of greatest snowpack instability due to unstable slab formation are expected near and above treeline on wind loaded N-NE-E aspects, 35 degrees and steeper. Any snowpack failure that occurs is expected to occur at the new snow/old snow interface or within the new snow. Natural avalanches may become possible above treeline during the overnight hours if new snowfall amounts approach 1 foot or more.

Below treeline, some areas of human triggered sluff activity will become possible very late today. This will occur most easily in open areas 37 degrees and steeper where new snow is deposited onto old snow surfaces that are in the form of smooth, frozen crust. Ideal bed surface conditions for sluff activity are found mainly above 7,500'.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. After the onset of precipitation this afternoon, avalanche danger will rise to MODERATE near and above treeline on wind loaded N-NE-E aspects 35 degrees and steeper. Avalanche danger will continue to rise during the overnight hours with natural avalanches becoming possible as snowfall continues.

SAC is very grateful of everyone who was involved in the SAC Ski Day fundraiser at Sugar Bowl. With the financial support of everyone who purchased SAC lift tickets and the organizational and marketing support of those who made the event possible, we were able to raise just over $10,000 for our operating budget. This will allow us to finish operations this spring and have funding for operations during the first two months of next winter. Thank you to all contributors, Sugar Bowl Ski Area, and Snowbomb.com!

Brandon Schwartz, Avalanche Forecaster

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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: 43 deg. F
Average wind direction at Sierra Crest past 24 hours: Westsouthwesterly
Average wind speed at Sierra Crest past 24 hours: 38 mph
Maximum wind gust at Sierra Crest past 24 hours: 70 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 62 inches

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Mountain Weather Forecast For Today:
Increasing clouds with showers in the morning, snowfall and decreasing air temperatures in the afternoon.
Temperature forecast for 8,000 to 9,000 feet: 30 to 34 degrees F. in the morning, 20's in the afternoon.
Ridgetop winds forecast for the Sierra Crest: Westsouthwest at 40-50 mph with gusts to 90 mph.
Snowfall expected in the next 24 hours: 8-12 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, increasing cloud cover and isolated snow showers in the morning. Widespread snowfall in the afternoon. Snow accumulation 4 to 6 inches. Daytime highs 34 to 39 degrees F, falling to around 30 degrees F. in the afternoon. Southwest winds at 25 to 35 mph with gusts to 50 mph. Tonight, continued snowfall, tapering to showers after 1 am. Snow accumulation 4 to 6 inches. Overnight lows 13 to 19 degrees F. West winds at 15 to 25 mph with gusts to 45 mph in the evening. West winds decreasing to 10 to 20 mph after midnight. Tuesday, cloudy with scattered snow showers. Snow accumulation up to 2 inches. Daytime highs 22 to 27 degrees F. Northwest winds at 15 to 25 mph, shifting to north in the afternoon are expected.

Above 8000 Feet:
Today, increasing cloud cover and isolated snow showers in the morning. Widespread snowfall in the afternoon. Snow accumulation 4 to 6 inches. Daytime highs 30 to 34 degrees F, falling into the 20s in the afternoon. Southwest winds at 30 to 40 mph with gusts to 60 mph. Tonight, continued snowfall, tapering to showers after 1 am. Snow accumulation 4 to 6 inches. Overnight lows 19 to 22 degrees F. West winds at 25 to 35 mph with gusts to 55 mph in the evening. West winds decreasing to 15 to 25 mph with gusts to 40 mph after midnight. Tuesday, cloudy with scattered snow showers. Snow accumulation up to 2 inches. Daytime highs 17 to 22 degrees F. Northwest winds at 25 to 35 mph, with gusts to 50 mph 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:
	Monday:	Monday Night:	Tuesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.