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 10, 2008 6:49 AM

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

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Today's Advisory:

This morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE avalanche danger will develop on E-SE-S-SW-W aspects, 37 degrees and steeper in response to daytime warming.

An air temperature inversion is in place over the forecast area this morning. Remote sensors indicate that overnight air temperatures did not fall below freezing in the vast majority of locations above 7,500'. Ridgetop winds have remained light for the past 24 hours. Winds have begun to increase from the southwest this morning and are expected to become moderate in speed by this afternoon. Increasing cloud cover and warm daytime air temperatures are expected across the forecast area today. A weak weather system passing to the north of the forecast area will bring isolated rain and snow showers to the area tonight. Snow level is forecast at 7,000' for this event.

Yesterday, warm air temperatures caused widespread melting of surface snow. Observations made on Mt. Tallac (Desolation Wilderness area) revealed melting of surface snow on E-SE-S-SW-W aspects up to 9,700' by mid day. Areas of wet snow where ski penetration exceeded 4 inches were observed on E aspects below 7,600' at 2 pm. Overnight, clear skies and radiational cooling of the snowpack are expected to have caused about the top 2 to 3 inches of the surface snow to refreeze despite above freezing air temperatures.

Today, warm air temperatures will again cause widespread melting of surface snow on sun exposed slopes at all elevations. Areas of wet snow instability are expected to develop as daytime warming occurs. With above freezing air temperatures at the upper elevations last night, melting of surface snow will occur faster today than yesterday due to the lack of a solid overnight refreeze. Natural avalanches are unlikely today. Human triggered avalanches will become possible, especially late in the day on steep E-SE-S-SW-W aspects.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE avalanche danger will develop on E-SE-S-SW-W aspects, 37 degrees and steeper in response to daytime warming.

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): 33 deg. F
Max. temperature at Sierra Crest past 24 hours: 48 to 58 deg. F.
Average wind direction at Sierra Crest past 24 hours: East shifting to west
Average wind speed at Sierra Crest past 24 hours: 11 mph.
Maximum wind gust at Sierra Crest past 24 hours: 28 mph
New snowfall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 81 inches

Mountain Weather Forecast For Today:
Partly to mostly cloudy skies and warm.
Temperature forecast for 8,000 to 9,000 feet: 41 to 46 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 10 to 20 mph with gusts to 35 mph. Winds increasing to 15 to 25 mph with gusts to 50 mph in the afternoon.
Snowfall expected in the next 24 hours: 0 to trace inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, partly cloudy skies in the morning, mostly cloudy skies in the afternoon. Daytime highs 50 to 56 deg. F. Light winds becoming southwest at 10 to 15 mph with gusts to 25 mph in the afternoon.

Tonight, mostly cloudy skies with isolated snow showers. Snow accumulation less than 1/2 inch. Overnight lows 29 to 35 deg. F. Southwest winds at 10 to 15 mph with gusts to 30 mph in the evening.

For Tuesday, partly cloudy skies with daytime highs 47 to 53 deg. F. West winds at 10 to 15 mph with gusts to 25 mph in the afternoon.

Above 8000 Feet:
Today, partly cloudy skies in the morning, mostly cloudy skies in the afternoon. Daytime highs 41 to 46 deg. F. Southwest winds at 10 to 20 mph with gusts to 35 mph. Winds increasing to 15 to 25 mph with gusts to 50 mph in the afternoon.

Tonight, mostly cloudy skies with isolated snow showers. Snow accumulation less than 1/2 inch. Overnight lows around 32 deg. F. Southwest winds at 20 to 30 mph with gusts to 50 mph.

For Tuesday, partly cloudy skies with daytime highs 38 to 43 deg. F. West winds at 15 to 25 mph with gusts to 40 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:
	Monday:	Monday Night:	Tuesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.