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 29, 2008 7:00 AM

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

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Today's Advisory:

Today, avalanche danger is LOW across most of the forecast area at all elevations and aspects. Some very small isolated pockets of MODERATE danger may exist where shallow, disconnected soft slabs formed on the most heavily wind loaded N-NE-E aspects above treeline on slopes steeper then 40 degrees.

A cold front started to pass across the forecast area yesterday afternoon. As it continues eastward isolated snow showers, cloudier skies, and cooler temperatures should prevail across the area. The winds should start to decrease as the front passes to the east later today. A series of low pressure systems moving across the Pacific Northwest over the weekend should keep temperatures cooler and skies cloudier through Sunday.

Cooler daytime temperatures and afternoon cloud cover kept the snow surface from softening very much during the day yesterday. The morning sun caused some lower elevation SE and S aspects in Blackwood Canyon to develop 2-3 inches of corn on the surface by noon. As the clouds moved in these melted surfaces started to slowly refreeze. By late in the afternoon snow showers started across the forecast area. Remote sensors along the Sierra Crest and in the Mount Rose area report that 1 to 3 inches of new snow has fallen accompanied by 40 to 50 mph SW winds. This new snow should have created "dust on crust" conditions on most slopes and should not be enough to increase the avalanche hazard in most areas. However ,along exposed ridgelines above treeline the winds could have transported enough snow to create some shallow soft slabs on the most heavily wind loaded N-NE-E slopes. These soft slabs will have formed on refrozen melt/freeze crusts and bonding between the soft slabs and crusts could be suspect. Snowpit observations over the last few days show a strong snowpack below the melt/freeze crusts and it should gain even more strength as it continues to refreeze.

These soft slabs could produce some very small and very isolated human triggerable avalanche activity that could knock a person off his/her feet or push someone over a cliff. These slabs should be very isolated in distribution, shallow, and small; therefore, they should not pose much of a burial threat to backcountry travelers. If more significant snowfall occurs today these slabs could increase in size and become more widespread in distribution. The strong deeper snowpack and small snow amounts should keep natural avalanche activity unlikely again today.

The bottom line: Today, avalanche danger is LOW across most of the forecast area at all elevations and aspects. Some very small isolated pockets of MODERATE danger may exist where shallow, disconnected soft slabs formed on the most heavily wind loaded N-NE-E aspects above treeline on slopes steeper then 40 degrees.
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.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 26 deg. F
Max. temperature at Sierra Crest past 24 hours: 29 to 36 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 40 mph
Maximum wind gust at Sierra Crest past 24 hours: 64 mph
New snowfall at 8,200 feet past 24 hours: 2 inches
Total snow depth at 8,200 feet: 80 inches
Mountain Weather Forecast For Today:
Mostly cloudy skies with isolated snow showers.
Temperature forecast for 8,000 to 9,000 feet: 31 to 37 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 20 to 35 mph with gusts to 60 mph decreasing to 15 to 20 mph with gusts to 30 mph in the afternoon.
Snowfall expected in the next 24 hours: trace to 2 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, mostly cloudy skies with isolated snow showers. Daytime highs 38 to 46 deg. F. Southwest winds at 10 to 15 mph.

Tonight, cloudy skies with scattered snow showers. Little or no snow accumulation. Overnight lows around 24 deg. F. with light southwesterly winds.

For Sunday, mostly cloudy skies with a slight chance of snow showers. Daytime highs 38 to 44 deg. F. Southwest winds 10 to 15 mph with gusts to 25 mph.

Above 8000 Feet:
Today, mostly cloudy skies with isolated snow showers. Daytime highs 31 to 37 deg. F. Southwest winds at 20 to 35 mph with gusts to 60 mph decreasing to 15 to 20 mph with gusts to 30 mph in the afternoon.

Tonight, cloudy skies with scattered snow showers. Light snow accumulation is possible. Overnight lows around 20 deg. F. Southwest winds at 10 to 15 mph increasing to 15 to 25 mph after midnight.

For Sunday, mostly cloudy skies with a slight chance of snow showers. Daytime highs 30 to 36 deg. F. West winds at 15 to 20 mph with gusts to 35 mph increasing to 20 to 30 mph with gusts to 55 mph in the afternoon.

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.