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, January 23, 2007 at 7:05 pm

The bottom line: Avalanche danger is LOW for all elevations and aspects. There is a small possibility that as the steep, sun-exposed SW-S-SE aspects warm up in the afternoon you may be able to cause some small, loose, wet sluffs.

First of all we want to say a heartfelt "thank you" to everyone who has made a contribution to the Avalanche Center this week. The show of support in both cash donations and Kirkwood Ski Day ticket purchases has been amazing! We still have a long way to go to reach our '06-'07 budget and even farther to meet our fund raising goal, but thanks to your generosity we are much closer. For more details on the current financial situation please click here. Our next fund raiser is another ski day on February 4th at Homewood. Tickets are on sale now at Snowbomb.com. If you can't make it but would still like to help out, please make a tax deductible donation directly to us via Paypal or by sending a check to our address listed above, c/o the Truckee Ranger Station. Your support is what makes the Sierra Avalanche Center possible.

Warm temperatures and calm winds prevailed again today. Temperatures above 7000' climbed above freezing early this morning and have stayed in the upper 30's and low 40's all day. The trend of calm and warm should continue for the next few days while this stable high pressure system remains over our area.

The warm temperatures will help bonds form faster between the snow grains and layers within the snowpack. This process should help the snowpack consolidate and gain some strength during the warm spell. The layers of faceted snow will be the slowest layers to gain strength. These typically weaker, sugary, snow grains still exist around some of the more pronounced crusts and have been observed as well formed depth hoar in the Mt Rose area. Even though some of these layers show weakness when isolated in layer bonding tests, it seems that the crusts and other more dense layers bounding them have remained fairly strong and are helping to maintain the overall strength of the snowpack.

This afternoon the southerly slopes again softened enough to provide some decent riding. Those southerly slopes will likely continue to provide the best sliding conditions over the next few days as they go through a daily melt-freeze cycle. Even though these slopes are the most tempting, remember that there is not much snow on them and you have to choose your lines carefully to avoid shallowly buried obstacles. On other aspects the melt freeze crust continued to spread and can be found in places on all but the N-NE aspects. As you get away from the southerly aspects, it is getting very hard to find any consistent conditions. The surface changes from breakable crust, to hard wind slab, to ice crust, to soft drifts with almost every turn.

No avalanche activity was reported today. A few "roller balls" formed on the sun exposed southerly slopes this afternoon but not much else. As the warm temperatures continue for the next few days we may see more of this roller ball activity and maybe a small, wet, loose snow sluff or two. These would be limited to steep, sun exposed, SW-S-SE slopes in the afternoons.

The bottom line: Avalanche danger is LOW for all elevations and aspects. There is a small possibility that as the steep, sun-exposed SW-S-SE aspects warm up in the afternoon you may be able to cause some small, loose, wet sluffs.

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

Andy Anderson , Avalanche Forecaster
Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet):
30 deg. F
Max. temperature at Sierra Crest past 24 hours:
47 deg. F
Average wind direction at Sierra Crest past 24 hours:
East
Average wind speed at Sierra Crest past 24 hours:
20-25 mph
Maximum wind gust at Sierra Crest past 24 hours:
42 mph
New snow fall at 8,200 feet past 24 hours:
0 inches
Total snow depth at 8,200 feet:
35 inches
Mountain Weather Forecast For Wednesday:
Sunny skies
Temperature forecast for 8,000 to 9,000 feet:
45 deg. F
Ridgetop winds forecast for the Sierra Crest:
Northeast 10 mph
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Tonight, clear skies with lows 21 to 31 degrees, F. Light variable winds. Wednesday, sunny skies with daytime highs around 46 degrees F. Winds are forecasted to be light and variable.

Above 8000 Feet
Tonight, clear skies with lows around 36 degrees, F. Northeast winds 10 mph. Wednesday, sunny skies with daytime highs around 44 degrees F. Winds are forecasted to be out of the southeast at 10 to 15mph.

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.