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 30, 2008 7:00 AM

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

1_low.jpg
Today's Advisory:

Today, avalanche danger should remain LOW across most of the forecast area at all elevations and aspects. If slopes see significant sunshine or faster than forecast warming occurs some very small and isolated areas of MODERATE danger could form on exposed slopes steeper than 40 degrees.

A low pressure area moving eastward across the forecast area should cause cloudier skies and cooler temperatures to continue today. A few isolated snow showers could still occur this morning. As this system moves east, skies should start to clear this afternoon, and a weak high pressure ridge should build over the area bringing clear skies and slightly warmer temperatures tomorrow.

Observations from Heavenly, Kirkwood, remote sensors along the northern Sierra Crest, and the Mount Rose backcountry showed that the new snow accumulation varied from 2 inches in some areas to 0 in others. The winds did transport some of the new snow, but the wind slabs that formed on the N-NE-E aspects remained very small and shallow. Some soft slabs up to 6 inches deep that only extended 1 0ft away from ridgelines formed in the Mount Rose area. These slabs and the new snow initially had difficulty bonding with the hard refrozen old snow surfaces near and above treeline; however, these bonds strengthened during the day yesterday. Below the old snow surfaces the snowpack remains strong and well bonded.

Cooler daytime temperatures, more forecasted cloud cover, decreased winds, very little new snow, and the bonding that is occurring between the new snow and the old snow surfaces should help keep snowpack instability to a minimum today. Some very small, shallow, and isolated pockets of soft wind slabs could still exist on the most heavily wind loaded N-NE aspects. These soft slabs should not be large enough to pose much of a threat to backcountry travelers unless they push someone into terrain that could be dangerous. These soft slabs should also be harder to trigger today. If the forecast area receives more sunshine than forecast or temperatures climb higher than forecast some instabilities could from due to rapid warming of the new snow. These would also be small and limited to point-release slides or other surface instabilities like pinwheels. Natural avalanche activity is unlikely again today.

The bottom line: Today, avalanche danger should remain LOW across most of the forecast area at all elevations and aspects. If slopes see significant sunshine or faster than forecast warming occurs some very small and isolated areas of MODERATE danger could form on exposed slopes steeper than 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): 20 deg. F
Max. temperature at Sierra Crest past 24 hours: 30 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 25 mph
Maximum wind gust at Sierra Crest past 24 hours: 52 mph
New snowfall at 8,200 feet past 24 hours: 0 to 1 inch
Total snow depth at 8,200 feet: 80 inches
Mountain Weather Forecast For Today:
Mostly cloudy skies with isolated snow showers in the morning then clearing in the afternoon.
Temperature forecast for 8,000 to 9,000 feet: 26 to 34 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 15 to 20 mph with gusts to 40 mph increasing to 20 to 30 mph with gusts to 55 mph in the afternoon.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, mostly cloudy skies with isolated snow showers. Daytime highs 34 to 42 deg. F. Southwest winds at 10 to 20 mph with gusts to 35 mph.

Tonight, partly cloudy skies with overnight lows around 24 deg. F. Winds out of the southwest at 10 to 15 mph with gusts to 25 mph then shifting to the northeast after midnight.

For Monday, partly cloudy skies with daytime highs 39 to 45 deg. F. and light southwest winds.

Above 8000 Feet:
Today, mostly cloudy skies with isolated snow showers. Daytime highs 26 to 34 deg. F. Southwest winds at 15 to 20 mph with gusts to 40 mph increasing to 20 to 30 mph with gusts to 55 mph in the afternoon.

Tonight, partly cloudy skies with overnight lows around 16 deg. F. Winds out of the west at 20 to 30 mph with gusts to 45 mph then decreasing after midnight.

For Monday, partly cloudy skies with daytime highs 31 to 37 deg. F. Southwest winds around 10 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:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.