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 30, 2007 at 5:45 pm

The bottom line: Avalanche danger is LOW for all elevations and aspects. Remember that low danger does not mean no danger. Even though human triggered avalanches are unlikely, there are a few small, isolated areas of instability on wind affected NW-N-NE aspects, 35 degrees and steeper. Continue to practice safe travel techniques like traveling one at a time through avalanche terrain and be especially wary of complex terrain.

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. For more details on the current financial situation please click here.

The high pressure has returned to our area bringing clear skies and warmer temperatures. Ridgetop winds should remain light for the next few days. Dry, northerly flow should continue through the weekend.

Our current snowpack looks much more like a continental snowpack than our typical maritime Sierra snowpack. Weak layers persist throughout the shallow snowpack. The current conditions continue to promote weak layer formation both within the snowpack and near the surface of the snowpack. On many of the NW-N-NE-E aspects surface hoar and near surface facets have formed a thin weak layer on the top of the snowpack. Within the snowpack facets are forming weak layers between the crusts and at the base of the snowpack. These weak, sugary grains on the surface and within the snowpack will not support much additional load. So unless conditions change before the next snowfall, these layers could easily become a failure layers. Over the last few days observers have reported that snowpit tests are showing moderate failures on the interfaces between the facets and crusts in the snowpack. Last week these same layer interfaces were not failing unless one applied much greater force during the tests. In some areas there are still a few small, isolated, hard slabs left by the strong easterly winds from earlier this month sitting on top of these facet / crust interfaces. Right now collapse at these interfaces in response to human triggers is unlikely, but not outside the realm of possibility.

No avalanche activity was reported yesterday.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Remember that low danger does not mean no danger. Even though human triggered avalanches are unlikely, there are a few small, isolated areas of instability on wind affected NW-N-NE aspects, 35 degrees and steeper. Continue to practice safe travel techniques like traveling one at a time through avalanche terrain and be especially wary of complex terrain.

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):
27 deg. F
Max. temperature at Sierra Crest past 24 hours:
35 deg. F
Average wind direction at Sierra Crest past 24 hours:
westerly
Average wind speed at Sierra Crest past 24 hours:
15-20 mph
Maximum wind gust at Sierra Crest past 24 hours:
35 mph
New snow fall at 8,200 feet past 24 hours:
0 inches
Total snow depth at 8,200 feet:
34 inches
Mountain Weather Forecast For Wednesday:
Sunny and mild.
Temperature forecast for 8,000 to 9,000 feet:
26-31 deg. F
Ridgetop winds forecast for the Sierra Crest:
Northerly 10-15mph
Snowfall expected in the next 24 hours:
none
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Tonight, clear this evening with lows 16-22 degrees F. Northeast winds 10 mph. Wednesday, clear skies with daytime highs 29 to 34 degrees F. Winds are forecasted to be out of the north at 10-15 mph.

Above 8000 Feet
Tonight, clear this evening with lows 18-24 degrees F. Northeast winds 10-20 mph. Wednesday, clear skies with daytime highs 26 to 31 degrees F. Winds are forecasted to be out of the north at 15-20 mph.

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.