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 Avalanche Advisory was published on February 3, 2007:


February 3, 2007 at 1:00 am

Forecast Discussion:


This advisory was posted on Saturday, February 3, 2007 at 4:45 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.

Tomorrow, February 4th is our ski day at Homewood. Tickets are on sale now at Snowbomb.com. We are hoping that all you backcountry enthusiasts will sacrifice watching the super bowl to come support the Avalanche Center. Not only will you get to ski for only $20, but you will also get to meet lots of other backcountry users, ask questions about the Avalanche Center, and of course enter to win some cool raffle prizes. Maybe if enough of us get together we can even make it snow next week! 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.

A weather system is currently passing to the north of the forecast area. Some clouds will remain in the area this afternoon as it moves through. Following this disturbance skies should clear up again, and temperatures are projected to stay warm. Ridgetop winds are expected to remain light for the next few days.

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 layer 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.

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):
36 deg. F
Max. temperature at Sierra Crest past 24 hours:
46 deg. F
Average wind direction at Sierra Crest past 24 hours:
easterly shifting to the southwest
Average wind speed at Sierra Crest past 24 hours:
10 mph
Maximum wind gust at Sierra Crest past 24 hours:
24 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 Sunday:
Sunny and warm.
Temperature forecast for 8,000 to 9,000 feet:
50 deg. F
Ridgetop winds forecast for the Sierra Crest:
East 10 - 15 mph
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Tonight, becoming clear with lows 18 to 28 degrees F and light winds. Sunday, sunny skies with daytime highs around 52 degrees F. Winds are forecasted to be out of the east at 10 to 15 mph.

Above 8000 Feet
Tonight, becoming clear with lows 23 to 29 degrees F. West winds 10 to 15 mph. Sunday, sunny skies with daytime highs around 50 degrees F. Winds are forecasted to be out of the east at 10 to 15 mph.

Backcountry Travelers:
We want to hear from you! If you see avalanche activity, or want to share condition information for an area you've been in, please let us know. Call (530) 587-3558 or e-mail us at:

sac_avalanche@fs.fed.us

.

Like our new look? Please share your comments! Send e-mail to

sac_avalanche@fs.fed.us

.


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.