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 20, 2008:


March 20, 2008 at 0:00 am

Forecast Discussion:


This advisory was posted on March 20, 2008 6:42 AM

A map of the SAC forecast area is available on our home page.

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Today's Advisory:
In most areas, avalanche danger is LOW for all elevations and aspects. Very isolated pockets of MODERATE danger may exist north of Hwy 50 in near and above treeline areas on the most heavily wind loaded N-NE-E aspects, 38 degrees and steeper.

A weak weather system passed through the northern portion of the forecast area yesterday afternoon and overnight. Skies have cleared this morning, leaving up to 3 inches of new snow in areas north of Hwy 50. Southwest ridgetop winds have been moderate in speed for the past 24 hours. Sunny skies and a warming trend are forecast for the next several days.

Yesterday, observations made in the Mount Rose area on Tamarack Peak and on Mount Rose proper revealed surface melt-freeze conditions in all sun exposed areas on all aspects. Snow surface melting on southerly aspects was observed all the way up to 10,000' by mid day. Pockets of cold surface snow lingered below treeline on very steep north aspects that are still able to escape direct sunlight, despite higher sun angles associated with this time of year. Melt-freeze and wind scoured snow surfaces dominated conditions on most N-NE-E aspects above treeline. Thick cloud cover was observed over the northern portion of the Sierra Crest by mid morning, spreading to the Mount Rose area by early afternoon. Remote sensors report maximum daytime air temperatures were 7 to 10 degrees warmer along the Sierra Crest in the southern portion of the forecast area than in the northern portion.

Today, melting of surface snow is expected in sun exposed areas, especially below 8,000'. Some natural and human triggered roller ball activity is expected in areas where new snow accumulated in the past 24 hours. Any wet snow instability that does occur today is not expected to present a hazard to backcountry travelers. Near and above treeline areas north of Hwy 50 where up to 3 inches of new snow has accumulated may hold very isolated pockets of unstable snow in the most heavily wind loaded areas on steep N-NE-E aspects. Instability is expected to limit to the very upper portion of avalanche start zones in the form of small and shallow surface slabs. Human triggered avalanches are possible in very isolated areas. Natural avalanche activity is unlikely today.

The bottom line: In most areas, avalanche danger is LOW for all elevations and aspects. Very isolated pockets of MODERATE danger may exist north of Hwy 50 in near and above treeline areas on the most heavily wind loaded N-NE-E aspects, 38 degrees and steeper.

Public donations to the avalanche center this season are below our fundraising goal. We are going to raffle a beacon, shovel, probe, and backpack package as a way give back to those who donate $100 or more before March 30th. For more information on the raffle and amount of donations received click here.

Brandon Schwartz, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 22 deg. F
Max. temperature at Sierra Crest past 24 hours: 34 to 43 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 35 mph
Maximum wind gust at Sierra Crest past 24 hours: 62 mph
New snowfall at 8,200 feet past 24 hours: 0 to 3 inches
Total snow depth at 8,200 feet: 85 inches

Mountain Weather Forecast For Today:
Partly cloudy skies.
Temperature forecast for 8,000 to 9,000 feet: 30 to 35 deg. F
Ridgetop winds forecast for the Sierra Crest: West at 20 to 30 mph with gusts to 50 mph.
Snowfall expected in the next 24 hours: 0 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, partly cloudy skies with daytime highs 36 to 41 deg. F. West winds at 10 to 20 mph with gusts to 35 mph.

Tonight, partly cloudy skies with overnight lows 20 to 25 deg. F. West winds at 15 to 25 mph, decreasing to 10 to 15 mph after midnight.

For Friday, partly cloudy skies with daytime highs 40 to 45 deg. F. Northwest winds around 10 mph.

Above 8000 Feet:
Today, partly cloudy skies with daytime highs 30 to 35 deg. F. West winds at 20 to 30 mph with gusts to 50 mph.

Tonight, partly cloudy skies with overnight lows 18 to 22 deg. F. West winds at 10 to 20 mph with gusts to 40 mph. West winds decreasing to 15 to 25 mph after midnight.

For Friday, partly cloudy skies with daytime highs 33 to 39 deg. F. Northwest winds at 15 to 20 mph with gusts to 30 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:

  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.