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, April 3rd, 2007 at 6:48 am

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. As daytime warming occurs, avalanche danger will rise to MODERATE above 8,000' on sun exposed E-SE-S-SW aspects 35 degrees and steeper. Below 8,000', avalanche danger will rise to MODERATE on all snow covered aspects, 35 degrees and steeper.

Thin, high level cloud cover formed over the forecast area last night and is expected to remain today. Air temperatures are significantly warmer this morning at all elevations as compared to yesterday morning. Ridgetop winds shifted to westsouthwesterly overnight and became light. Winds are expected to shift back to westerly as the day progresses and increase to moderate in speed. A splitting weather system is still expected to bring increasing mid level cloud cover to the forecast area late today and overnight. A slight chance of showers exists for Wednesday afternoon.

Air temperatures above 6,500' in elevation fell only into the upper 30s and low 40s last night. The absence of thick cloud cover still allowed for radiational cooling to refreeze the snow surface. This created a melt-freeze surface crust only a few inches thick this morning. As daytime warming occurs, this crust will rapidly melt, creating free water formation in the snowpack and subsequent areas of wet snow instability.

With the exception of isolated pockets on north aspects around 10,000' in elevation, all areas of the snowpack have entered a daily melt-freeze cycle. Snow surface conditions vary widely from rough and bumpy to smooth and enjoyable. On many northerly aspects above 9,000', snow from the last storm has not yet made the transition from new snow to high quality corn snow. Only a thin melt-freeze crust exists on the snow surface. More melt-freeze cycles are needed to finish the transformation. Below 9,000', excellent corn snow conditions can be found mid morning in many areas, especially on E and SE aspects.

Any avalanche activity is unlikely prior to mid morning. As daytime warming occurs, areas of wet snow instability will form on steep slopes, in a variety of areas. Human triggered avalanches will become possible above 8,000' on E-SE-S-SW aspects, 35 degrees and steeper. Below 8,000', human triggered avalanches will become possible on all snow covered aspects, 35 degrees and steeper.

Keep in mind that when boot penetration in wet snow exceeds boot top height, human triggered wet snow avalanches are possible in that area. Step off of your equipment on a regular basis to check boot penetration. When evidence of wet snow instability such as deep boot penetration or pinwheels larger than 1 foot in diameter develop, move to a less sun exposed aspect or call it a day.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. As daytime warming occurs, avalanche danger will rise to MODERATE above 8,000' on sun exposed E-SE-S-SW aspects 35 degrees and steeper. Below 8,000', avalanche danger will rise to MODERATE on all snow covered aspects, 35 degrees and steeper.

The Heavenly Ski Patrol has been generous enough to include the Sierra Avalanche Center as one of the benefactors of their annual fundraising party this year. The party is this Friday, April 6th at the Horizon Casino Resort in South Lake Tahoe from 7pm to midnight. Tickets are $10 at the door. A portion of the proceeds will go to the SAC operating budget for next season. For more information please click here. We will also raffle off 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): 39 deg. F
Max. temperature at Sierra Crest past 24 hours: 43 deg. F
Average wind direction at Sierra Crest past 24 hours: Westerly
Average wind speed at Sierra Crest past 24 hours: 20 mph
Maximum wind gust at Sierra Crest past 24 hours: 46 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 61 inches

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Mountain Weather Forecast For Today:
Sunny skies becoming partly cloudy in the late afternoon.
Temperature forecast for 8,000 to 9,000 feet: 46 to 52 degrees F.
Ridgetop winds forecast for the Sierra Crest: Westerly at 15 to 20 mph with gusts to 30 mph
Snowfall expected in the next 24 hours: 0 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, sunny skies becoming partly cloudy in the late afternoon. Daytime highs around 56 degrees F. West winds at 10 to 15 mph. Tonight, mostly cloudy skies with overnight lows 33 to 39 degrees F. Southwest winds at 10 to 15 mph. Wednesday, mostly cloudy skies with a slight chance of showers in the afternoon. Daytime highs 48 to 56 degrees F. Southwest winds at 10 to 15 mph are expected.

Above 8000 Feet:
Today, sunny skies becoming partly cloudy in the late afternoon. Daytime highs 46 to 52 degrees F. West winds at 15 to 20 mph with gusts to 30 mph. Tonight, mostly cloudy skies with overnight lows around 35 degrees F. Southwest winds at 15 to 25 mph with gusts to 35 mph. Wednesday, mostly cloudy skies with a slight chance of showers in the afternoon. Daytime highs 42 to 52 degrees F. Southwest winds at 15 to 20 mph with gusts to 30 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.