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 Tuesday, March 20th, 2007 at 6:59 am

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. After the onset of snowfall, avalanche danger will rise to MODERATE this afternoon in wind loaded areas near and above treeline on N-NE-E aspects 35 degrees and steeper.

A weak and splitting weather system is approaching the forecast area this morning. A few isolated light rain and snow showers occurred last night, but the period of heaviest precipitation is not expected until this afternoon. Less than 8 inches of new snowfall is expected as total accumulation with this weather system. Maximum daytime air temperatures for today will occur this morning. Cooling is expected this afternoon with cold front passage. Westsouthwesterly ridgetop winds increased yesterday afternoon and are expected to continue through the day today. Moderate ridgetop wind speeds are expected to continue today before wind speeds decrease and shift to northeasterly overnight.

Last night, air temperatures at the upper elevations fell below freezing. Minimal warming is expected this morning, allowing the wet upper snowpack on E-S-W aspects to continue to refreeze during the day today. This is a slow process. Areas of unfrozen wet snow may remain in the top few feet of the snowpack on Wednesday. On northerly aspects, high density and well bonded layers exist within all heights of the snowpack. Deep slab instability is unlikely at this time. Areas of snowpack instability that form today will consist of new snow.

As snowfall increases this afternoon, areas of instability will form in wind loaded areas on N-NE-E aspects near and above treeline. A significant density difference will occur as new snow falls on the frozen old snow surface. Any snowpack failure today is expected this afternoon in response to human triggers, occurring at or above the old snow/storm snow interface. Crown height is expected to be less than 1 foot. Natural avalanche activity is unlikely today.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. After the onset of snowfall, avalanche danger will rise to MODERATE this afternoon in wind loaded areas near and above treeline on N-NE-E aspects 35 degrees and steeper.

At this time, SAC is still short $1,700 in operating funds for this season and we have no money with which to start next season. Our next fundraiser is this Sunday, March 25th at Sugar Bowl Ski Area. We are selling $30 lift tickets that have been donated to us by Sugar Bowl. All proceeds from each ticket sale go directly to our operating budget. Tickets are only available online through Snowbomb.com. Tickets can be easily obtained up to the night before the event. Click here to purchase your lift ticket. Come on out and join us for wonderful day of spring sun on the deck, corn snow slopes, and a gear raffle from Backcountry Access, Black Diamond, and Patagonia. We are very appreciative of the financial support already received this winter from a variety of users. If you have not yet shown your financial support for us this winter, please do so!

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 28 deg. F
Max. temperature at Sierra Crest past 24 hours: 45 deg. F
Average wind direction at Sierra Crest past 24 hours: Westsouthwesterly
Average wind speed at Sierra Crest past 24 hours: 36 mph
Maximum wind gust at Sierra Crest past 24 hours: 58 mph
New snow fall at 8,200 feet past 24 hours: 0-trace inches
Total snow depth at 8,200 feet: 67 inches

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Mountain Weather Forecast For Today:
Cloudy with snow showers.
Temperature forecast for 8,000 to 9,000 feet: 25 to 35 degrees F.
Ridgetop winds forecast for the Sierra Crest: Westsouthwesterly 35-45 mph, G 60 mph.
Snowfall expected in the next 24 hours: 2-6 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, cloudy snow showers. Snow accumulation up to 4 inches. Daytime highs 36 to 41 degrees F., dropping to 30 to 35 degrees F. in the afternoon. Southwest winds at 15 to 25 mph with gusts to 35 mph. Tonight, mostly cloudy with scattered snow showers, becoming more isolated after midnight. Snow accumulation up to 2 inches. Overnight lows 20 to 25 degrees F. Northwest winds at 15 to 25 mph, shifting to north after midnight. Wednesday, partly cloudy with daytime highs 30 to 35 degrees F. Northeast winds at 10 to 20 mph with gusts to 30 mph are expected.

Above 8000 Feet:
Today, cloudy snow showers. Snow accumulation up to 6 inches. Daytime highs 30 to 35 degrees F., dropping to 25 to 30 degrees F. in the afternoon. Southwest winds at 25 to 35 mph with gusts 50 to 60 mph. Tonight, mostly cloudy with scattered snow showers. Snow accumulation up to 2 inches. Overnight lows 15 to 20 degrees F. Northwest winds at 15 to 25 mph, shifting to north after midnight. Wednesday, partly cloudy with daytime highs 25 to 30 degrees F. Northeast 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:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.