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 Friday, January 19, 2007 at 2:18 pm

Our current financial situation is still in jeopardy. (for details click here) We still do not have enough money to finish out this season. We need your help to make our second fundraiser this Sunday at Kirkwood a success. By purchasing a $40 SAC ski day lift ticket online before Sunday at Snowbomb.com, you will get to ride the lifts at Kirkwood for 40% off of their normal rate. The entire purchase price of $40 goes directly to supporting the Sierra Avalanche Center. This event is much more than just a day of cheap resort skiing. We will be there all day to meet you and answer your questions. Lots of other folks who are traditionally in the backcountry will also be there trading stories and making turns together. On top of the fun, we will have some great raffle prizes to give away. If you can't make it but would still like to help out, please make a tax deduct able donation directly to us via Paypal or by sending a check to our address listed above, c/o the Truckee Ranger Station. Thank you for your support.

A series of very week weather disturbances will move through the forecast area over the next few days. These systems are expected to produce nothing more than some mid to high level clouds and minor changes in wind speed and direction. Air temperature inversion remains in place allowing for warmer air temperatures at the upper elevations than in the valleys.

Cold snowpack temperatures continue on northerly aspects at all elevations. A temperature gradient of 2 to 3 degrees C. per 10 cm of height continues to exist within the snowpack. This is a temperature gradient that is strong enough to create sufficient vapor pressure to continue the faceting of snow crystals within the snowpack. The rate of faceting has slowed over the past few days in response to gradual warming, but the process has not yet stopped. Layer bonding tests are showing hard force shears on faceted layers that were not producing shear failure 4 to 5 days ago. Overall, the snowpack remains stable at this time, but it is gradually loosing strength. The snowpack on E-S-W aspects is recovering nicely after the cold air temperatures of last week. Diurnal melt-freeze of surface snow is occurring on southerly aspects.

Snow surface conditions remain variable by aspect and elevation. There are two options for the best riding conditions, given the current weather and snowpack. Below treeline, some pockets of shallow, unconsolidated snow linger on northwesterly aspects that are well protected from east winds. Above treeline, snow covered south aspects in the 7,500' to 8,500' elevation range are receiving sufficient sun to soften and provide fun turns around mid day. Above treeline on all aspects, stable hard slab conditions exist. Near and below treeline is a mix of melt-freeze crust, stable hard slab, and unconsolidated snow depending on aspect. There are beacon basins located at the base of Squaw Valley and Kirkwood, if you have yet to practice you rescue skills this season.

Avalanche danger is LOW for all elevations and aspects.

The next scheduled update to this advisory will occur tomorrow afternoon.

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 22 deg. F
Max. temperature at Sierra Crest past 24 hours: 34 deg. F
Average wind direction at Sierra Crest past 24 hours: easterly shifting to northerly
Average wind speed at Sierra Crest past 24 hours: 38 mph
Maximum wind gust at Sierra Crest past 24 hours: 68 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 35 inches

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Mountain Weather Forecast For Saturday:
Partly cloudy skies
Temperature forecast for 8,000 to 9,000 feet: 33 - 38 deg. F
Ridgetop winds forecast for the Sierra Crest: northwesterly 10 - 15 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
Saturday, partly cloudy skies with daytime highs around 38 degrees F. North winds 10 to 15 mph. Overnight, partly cloudy skies with lows around 17 degrees F. North winds at 10 to 20 mph. Sunday will be partly cloudy with daytime highs around 33 degrees F. East winds at 10 to 15 mph are expected.

Above 8000 Feet
Saturday, partly cloudy skies with daytime highs around 36 degrees F. Northwest winds 10 to 15 mph with gusts to 30 mph. Overnight, partly cloudy skies with lows around 19 degrees F. Northeast winds 15 to 20 mph with gusts to 50 mph. Sunday will be partly cloudy with daytime highs around 32 degrees F. East winds at 15 to 20 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:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.