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 Saturday, March 24th, 2007 at 7:05 am

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 on the 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!

The bottom line: Avalanche danger is LOW for all elevations and aspects. As daytime warming occurs a few small, isolated pockets of MODERATE avalanche danger may develop on SW-S-SE-E slopes 35 degrees and steeper that are exposed to the sun today in the form of wet snow instabilities.

Today temperatures are supposed peak before the high pressure ridge begins to diminish and move to the east. The winds are forecasted to begin shifting and increasing this afternoon. By Sunday they are forecasted to be moderate out of the southwest and should continue to gain strength as the low pressure system approaches Sunday night. Temperatures should also begin a cooling trend on Sunday and should drop down to about 10 degrees below normal as the cold low pressure system arrives over the area by Monday. Even though there is a decent amount of moisture associated with this system, it is starting to look like it might split meaning less precipitation for the forecast area.

Today's high temperatures should peak another 5 degrees warmer than yesterday. The overnight lows also stayed above freezing last night. The continued east and northeast winds along with the clear skies allowed the snowpack to undergo some refreezing due to radiational cooling. This refreeze should be less robust than the previous days, and the snow should begin to soften much earlier today. These warm temperatures are nothing new. After last week's extended period of unseasonable warm temperatures, water percolation channels are well developed through the snowpack in most areas. These channels should help prevent widespread pooling of water at layer interfaces within the snowpack: a process that can weaken the snowpack greatly. The prolonged melt-freeze cycles have also allowed the snowpack to become much more uniform a trend that promotes an increase the overall stability over the long term. In the short term snowpack stability goes through a daily oscillation during the melt freeze cycles. Instability peaks shortly after the peak of the melting phase of the melt-freeze cycle when the most water is present in the snowpack. The peak of today's melt-freeze cycle should have a less intense effect on stability than last week due to more gradual warming, slightly lower high temperatures, stronger refreezes, and those more developed percolation channels. Therefore the chance of wet snow instabilities should be less widespread and severe.

Any wet snow instabilities that do develop in response to daytime warming today should be limited to surface instabilities like pinwheels, roller-balls, and maybe a small wet loose sluff on SW-S-SE-E aspects on slopes steeper than 35 degrees that are exposed to the sun today. Natural and human triggered wet slab avalanches are unlikely today but not impossible. Areas around glide cracks and in places where the snowpack is sitting on an impermeable ground surface like bedrock would be the most likely to produce one of the rare wet slabs.

As the day warms up good corn conditions should develop quickly on the sun exposed SW-S-SE-E aspects across the forecast area. There should be a good supportable base under the corn due to the solid refreezes. This corn should happen early today and quickly become sloppy, wet, punchy, and less stable by the afternoon. Remember to continually evaluate the conditions as they change over the course of the day and be willing to change plans accordingly. A good test for wet snow instability potential is to step off your equipment and check boot penetration in the snowpack. If boot penetration exceeds boot tops in wet snow, it is time to move away from that slope and slopes like it.

The bottom line: Avalanche danger is LOW for all elevations and aspects. As daytime warming occurs a few small, isolated pockets of MODERATE avalanche danger may develop on SW-S-SE-E slopes 35 degrees and steeper that are exposed to the sun today in the form of wet snow instabilities.

Andy Anderson , Avalanche Forecaster
Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet):
36 deg. F
Max. temperature at Sierra Crest past 24 hours:
50-56 deg. F
Average wind direction at Sierra Crest past 24 hours:
Easterly
Average wind speed at Sierra Crest past 24 hours:
25 mph
Maximum wind gust at Sierra Crest past 24 hours:
44 mph
New snow fall at 8,200 feet past 24 hours:
0 inches
Total snow depth at 8,200 feet:
65 inches
Mountain Weather Forecast For Today:
Sunny skies with scattered clouds.
Temperature forecast for 8,000 to 9,000 feet:
42 to 48 degrees F.
Ridgetop winds forecast for the Sierra Crest:
Northeasterly 10-15 mph shifting to the west at 10-20 mph with gusts to 30 mph in the afternoon.
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, sunny skies with scattered clouds and daytime highs 48 to 56 degrees F. Northeast winds at 5 to 10 mph shifting to the west at 10 mph with gusts to 20 mph in the afternoon. Tonight, mostly cloudy skies with overnight lows 30 to 36 degrees F. West winds at 5 to 15 mph with gusts to 25 mph. Tomorrow, mostly cloudy skies with daytime highs 44 to 52 degrees F. Southwest winds at 10 to 20 mph with gusts to 35 mph are expected.

Above 8000 Feet:
Today, sunny skies with scattered clouds and daytime highs 42 to 48 degrees F. Northeast winds at 10 to 15 mph shifting to the west at 10-20 mph with gusts to 30 mph in the afternoon. Tonight, mostly cloudy skies with overnight lows 34 to 40 degrees F. West winds at 10 to 20 mph with gusts to 40 mph. Tomorrow, mostly cloudy skies with daytime highs 38 to 44 degrees F. Southwest winds at 20 to 30 mph with gusts to 60 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:
	Saturday:	Saturday Night:	Sunday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.