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 Sunday, April 15th, 2007 at 6:48 am

The bottom line: Near and above treeline, pockets of MODERATE avalanche danger exist in wind loaded areas on a variety of slope aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW.

Yesterday's weather system is moving out of the forecast area today. Wrap around moisture is creating lingering snow showers over the forecast area, especially along the eastern edge. Snow showers are expected to gradually taper off during the day with snow level remaining around 6,000'. Ridgetop winds have shifted from westsouthwesterly to moderate northeasterly this morning and are expected to continue into Monday. Cloud cover is expected to clear late today with a significant warming of air temperatures forecasted for Monday.

One human triggered avalanche was reported to occur yesterday. The avalanche was triggered by a high marking snowmobile in the bowl below the Fourth of July Chutes area of Blackwood Canyon on the West Shore of Lake Tahoe. The avalanche is believed to have involved snow from the Wednesday and Saturday weather systems, failing 12-15" deep with a hard melt-freeze crust layer as the bed surface. Any other information concerning time the of occurrence, exact aspect, elevation, slope angle, type of avalanche, exposure of the slope to recent wind, number of previous passes on the slope, and the actual length and width of the avalanche are unknown. The avalanche is believed to have been fairly small.

Storm totals of 3-6" have been reported throughout the forecast area this morning. Wind loading created some new soft slab formation near and above treeline on N-NE-E aspects during the day yesterday. Shifting winds overnight are expected to have redistributed the new snow, creating pockets of instability on a variety of aspects near and above treeline this morning. These areas of instability are expected to be small and shallow, involving only pockets of wind loaded snow and not entire slopes.

Isolated human triggered avalanches remain possible today in wind loaded areas near and above treeline on a variety of aspects, 35 degrees and steeper. Human triggered avalanches are unlikely below treeline. Natural avalanches are unlikely today in all areas.

The bottom line: Near and above treeline, pockets of MODERATE avalanche danger exist in wind loaded areas on a variety of slope aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW.

We will raffle a BCA backpack, beacon, shovel, and probe package on April 17th as a way to say thanks to everyone who has sent us a donation in the mail or via Pay Pal this season. All individuals who have donated $10 or more to SAC are automatically entered in this raffle. Thanks to all of our sponsors, the ski days, and everyone who has donated funding this winter, we have met our operating budget for this season and have a start on next year's funding. For more details about our financial situation please click here.

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 23 deg. F
Max. temperature at Sierra Crest past 24 hours: 28 deg. F
Average wind direction at Sierra Crest past 24 hours: Westsouthwesterly shifting to northeasterly
Average wind speed at Sierra Crest past 24 hours: 35 mph
Maximum wind gust at Sierra Crest past 24 hours: 67 mph
New snow fall at 8,200 feet past 24 hours: 3-6 inches
Total snow depth at 8,200 feet: 58 inches

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Mountain Weather Forecast For Today:
Mostly cloudy skies with scattered snow showers.
Temperature forecast for 8,000 to 9,000 feet: 30 - 40 degrees F.
Ridgetop winds forecast for the Sierra Crest: Northeasterly 30 - 40 mph, gusting to 60 mph
Snowfall expected in the next 24 hours: trace - 2 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, mostly cloudy skies with scattered snow showers through the day. Snow accumulation trace to 2". Daytime highs 37 to 43 degrees F. Northeast winds at 20 to 30 mph. Tonight, clear skies with overnight lows 20 to 26 degrees F. Northeast winds at 20 to 30 mph. Monday, sunny skies with daytime highs 47 to 53 degrees F. Northeast winds at 10 to 15 mph are expected.

Above 8000 Feet:
Today, mostly cloudy skies with scattered snow showers in the morning. Isolated snow showers in the afternoon. Snow accumulation trace to 2". Daytime highs 30 to 40 degrees F. Northeast winds at 30 to 40 mph, gusting to 60 mph. Tonight, clear skies with overnight lows around 21 degrees F. Northeast winds at 25 to 35 mph with gusts to 70 mph. Monday, sunny skies with daytime highs 42 to 48 degrees F. North winds at 15 to 25 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:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.