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 March 8, 2007:


March 8, 2007 at 1:00 am

Forecast Discussion:


This advisory was posted on Thursday, March 8th, 2007 at 6:57 am

The bottom line: Avalanche danger is LOW for most areas. Very isolated pockets of MODERATE danger will develop today below 8,500' on E-SE-S-SW aspects, 35 degrees and steeper in response to daytime warming. Very isolated human triggered wet snow avalanches are possible. Normal caution is advised while traveling in the backcountry.

The weak weather system that passed through the forecast area yesterday has moved off to the east, leaving building high pressure over our area. Cloud cover and isolated areas of light precipitation occurred yesterday and overnight. Westerly ridgetop winds increased during the day yesterday and are expected to decrease slightly and continue through the day today. Some clouds will linger over the Sierra Crest today, but plenty of sunshine is expected. Daytime air temperatures are expected to continue to warm through the weekend.

Widespread melt-freeze snow surface conditions exist throughout the forecast area. On southerly aspects, these conditions extend above 9000'. On northerly aspects above 8,500', some pockets of well settled, unconsolidated snow linger in areas protected from wind and sun. Isolated rain and snow showers deposited less than one inch of new snow above 7,000' in a few areas. In most locations, no measurable new snowfall occurred. Rain showers below 6,500' were followed by below freezing air temperatures overnight. This has not created an appreciable change in the shallow snowpack in this elevation zone.

Warm daytime air temperatures over the past several days have produced roller balls and large human triggered pinwheels on the majority of aspects, especially below 8,500'. No human triggered or natural wet snow avalanches have been reported, despite these signs of surface instability. As air temperatures continue to warm over the next few days, the possibility of human triggered avalanche activity will increase.

The bottom line: Avalanche danger is LOW for most areas. Very isolated pockets of MODERATE danger will develop today below 8,500' on E-SE-S-SW aspects, 35 degrees and steeper in response to daytime warming. Very isolated human triggered wet snow avalanches are possible. Normal caution is advised while traveling in the backcountry.

At this time, we are still short $3,000 in funding for our operating budget this winter. If you use this service with any regularity and would like to continue to do so, please show your financial support for the Sierra Avalanche Center. You may 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. A graph showing the amount of fundraising completed this season and our overall budget is available by clicking here. The financial support already received this winter from a variety of users is greatly appreciated.

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 28 deg. F
Max. temperature at Sierra Crest past 24 hours: 38 deg. F
Average wind direction at Sierra Crest past 24 hours: Westerly
Average wind speed at Sierra Crest past 24 hours: 43 mph
Maximum wind gust at Sierra Crest past 24 hours: 80 mph
New snow fall at 8,200 feet past 24 hours: 0-1 inches
Total snow depth at 8,200 feet: 91 inches

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Mountain Weather Forecast For Today:
Sunny to partly cloudy skies.
Temperature forecast for 8,000 to 9,000 feet: 37 to 45 degrees F.
Ridgetop winds forecast for the Sierra Crest: Westerly 15-25 mph, G 50 mph. Shifting to southwesterly and decreasing in the afternoon.
Snowfall expected in the next 24 hours: 0 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet
Today, sunny to partly cloudy with daytime highs 45 to 51 degrees F. Southwest winds at 10 to 15 mph with gusts to 30 mph. Tonight, clear to partly cloudy with overnight lows 24 to 30 degrees F. Southwest winds at 10 to 20 mph with gusts to 25 mph in the evening. Friday, sunny to partly cloudy with daytime highs 47 to 53 degrees F. Southwest winds at 10 to 15 mph are expected.

Above 8000 Feet
Today, sunny to partly cloudy with daytime highs 37 to 45 degrees F. West winds at 15 to 25 mph with gusts to 50 mph. Winds shifting to southwest and decreasing to 10 to 15 mph in the afternoon. Tonight, clear to partly cloudy with overnight lows around 29 degrees F. Southwest winds at 15 to 25 mph with gusts to 30 mph in the evening. Friday, sunny to partly cloudy with daytime highs 41 to 47 degrees F. West winds at 10 to 20 mph with gusts to 25 mph in the afternoon 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:

  Thursday: Thursday Night: Friday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:

  Thursday: Thursday Night: Friday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.