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 Sunday, February 4th, 2007 at 6:15 pm

The bottom line: Avalanche danger is LOW for all elevations and aspects. Human triggered avalanches are unlikely, but not impossible in very isolated areas near treeline on NW-N-NE aspects, 35 degrees and steeper.

Thanks to everyone who came out an supported us at Homewood! We will update the financial graph as soon as we get the final numbers, but it looks we still have not made the budget for this year and we are still a long way from the fundraising goal. If you like what we do and want to see it continue, 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 ridge that has been sitting over us for a month is forecasted to start breaking down this week. Early in the week a system is projected to move through to the north of us bringing some clouds to this area. It should help push the long lived high pressure out of here to make room for some stormy low pressure systems to move in later in the week. We will see. For the next few days temps should remain warm and the winds are forecasted to start shifting to the south. They should still be light until later in the week.

Even though the air temperatures are quite warm, the snowpack temperatures on northerly aspects have remained cold throughout the forecast area. The cold snow temperatures and the shallow snowpack continue to promote faceting through out the snowpack at all elevations. These sugary grains are most prevalent and weakest in the the Mount Rose area and along the Sierra Crest below 8000' where the snowpack is very shallow. Above 8,000', a deeper snowpack ranging from 4-5 feet deep, is showing less faceting and more stability overall. Highly variable snowpack strength has been observed over the past few days. Layer bonding tests continue to fail within the weak faceted layers and at the facet/crust interfaces. Many of these tests in the in the Mount Rose area and in some areas along the Sierra Crest in the 7,500' to 8,500' elevation range are failing once moderate force is applied. Above 8,500' along the Sierra Crest these same tests take much more force to reach the failure point. The snowpack at these elevations seems to be much more stable due to greater depth and less faceting. Very isolated areas exist on northerly aspects where human triggered avalanches are unlikely but not impossible on faceted weak layers. Check out some of the snowpits from around the forecast area here.

Faceting of surface snow below treeline on northerly aspects has created a layer of soft, fun snow in areas that do not have many tracks. A daily melt-freeze cycle continues on southerly aspects providing some soft riding conditions on these slopes by early afternoon.

No avalanche activity was reported today.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Human triggered avalanches are unlikely, but not impossible near treeline on NW-N-NE aspects, 35 degrees and steeper.

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

Brandon Schwartz and Andy Anderson, Avalanche Forecasters
Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet):
34 deg. F
Max. temperature at Sierra Crest past 24 hours:
45 deg. F
Average wind direction at Sierra Crest past 24 hours:
easterly
Average wind speed at Sierra Crest past 24 hours:
20 mph
Maximum wind gust at Sierra Crest past 24 hours:
38 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 Monday:
Sunny and warm.
Temperature forecast for 8,000 to 9,000 feet:
53 deg. F
Ridgetop winds forecast for the Sierra Crest:
South 10 - 15 mph
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Tonight, clear with lows 20 to 35 degrees F and southeast winds at 15-20 mph. Monday, sunny skies with daytime highs around 56 degrees F. Winds are forecasted to be out of the south at 10 to 15 mph.

Above 8000 Feet
Tonight, clear with lows 30 to 38 degrees F and southeast winds at 15-20 mph. Monday, sunny skies with daytime highs around 53 degrees F. Winds are forecasted to be out of the south at 10 to 15 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:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.