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 March 14, 2008 6:52 AM

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

1_low.jpg
Today's Advisory:

In most areas, avalanche danger is LOW on all aspects. Above 8,700', isolated pockets of MODERATE avalanche danger exist on wind loaded N-NE-E aspects, 37 degrees and steeper.

A series of weak weather systems continue to impact the forecast area. Cold front passage occurred late Thursday, dropping snow level to below 5,000' across the area. Storm totals are running 1 to 4 inches with the greatest accumulations observed above 8,500'. Ridgetop winds have remained from the southwest for the past several days. Wind speed has decreased from strong to moderate during the early hours this morning. Snow shower activity with light accumulation is expected to continue today.

Yesterday, precipitation began during the early morning hours with snow level near 8,700'. Snow level lowered to around 7,000' by mid day before lowering to below 5,000' overnight. On Andesite Peak (Donner Summit area), observations on NE-E-SE-S aspects between 7,200' and 8,200' revealed wet, rain affected snow within the top 1 foot of the snowpack. Between 7,800' and 8,200', excellent bonding of new snow to the wet old snow surface was observed, even in heavily wind loaded areas above treeline. Snowpit data and test slope loading revealed no signs of instability in this area. Observations made above Ophir Creek (Mount Rose area) indicated poor bonding of new snow to the old snow surface on all aspects above 9,000'. Good bonding was observed at the old/new snow interface in areas below 8,500' where rain had fallen earlier in the day.

Today, expect conditions below 8,700' to consist of shallow new snow on top of wet rain affected snow. The wet, rain affected snow will take several days to fully refreeze, despited continuous below freezing air temperatures. Some isolated small and shallow slabs exist in wind loaded areas, mainly on N-NE-E aspects. Isolated human triggered avalanches are possible in wind loaded areas above 8,700' where precipitation for this event has fallen entirely as snow and bonding at the old/new snow interface is poor to fair.

The bottom line: In most areas, avalanche danger is LOW on all aspects. Above 8,700', isolated pockets of MODERATE avalanche danger exist on wind loaded N-NE-E aspects, 37 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): 16 deg. F
Max. temperature at Sierra Crest past 24 hours: 31 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 53 mph.
Maximum wind gust at Sierra Crest past 24 hours: 97 mph
New snowfall at 8,200 feet past 24 hours: 2 to 4 inches
Total snow depth at 8,200 feet: 80 inches

Mountain Weather Forecast For Today:
Mostly cloudy with scattered snow showers.
Temperature forecast for 8,000 to 9,000 feet: 18 to 24 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 20 to 30 mph with gusts to 50 mph.
Snowfall expected in the next 24 hours: 2 to 6 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, mostly cloudy skies with scattered snow showers. Snow accumulation up to 1 inch. Daytime highs 23 to 30 deg. F. Southwest winds at 10 to 20 mph with gusts to 35 mph. Winds increasing to 15 to 25 mph with gusts to 40 mph in the afternoon.

Tonight, cloudy skies with snow showers. Snow accumulation 1 to 3 inches. Overnight lows 12 to 18 deg. F. Southwest winds at 15 to 25 mph with gusts to 35 mph.

For Saturday, cloudy skies with snow showers. Snow accumulation 1 to 3 inches. Daytime highs 22 to 27 deg. F. West winds at 10 to 15 mph.

Above 8000 Feet:
Today, mostly cloudy skies with scattered snow showers. Snow accumulation up to 2 inches. Daytime highs 18 to 24 deg. F. Southwest winds at 20 to 30 mph with gusts to 50 mph.

Tonight, cloudy skies with snow showers. Snow accumulation up to 4 inches. Overnight lows 8 to 12 deg. F. Southwest winds at 20 to 30 mph with gusts to 45 mph.

For Saturday, cloudy skies with snow showers. Snow accumulation 2 to 4 inches. Daytime highs 16 to 22 deg. F. West winds at 10 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:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.