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 February 27, 2008 6:46 AM
Click here for a detailed map of the SAC forecast area

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Today's Advisory:

Early this morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE avalanche danger will develop at all elevations on the majority of aspects, 37 degrees and steeper in response to daytime warming.

An air temperature inversion is in place over most of the forecast area again this morning. Remote sensors report air temperatures at the upper elevations are several degrees colder this morning than temperatures observed 24 hours ago. Air temperatures are forecast to warm into the upper 40s to low 50s at all elevations today. Ridgetop winds shifted to the southwest yesterday morning and have remained light for the past 24 hours. A weak weather system passing well to the north will spread high clouds over the forecast area today.

Yesterday, an additional 4 to 5 inches of settlement was reported in most locations across the forecast area. Snowpit observations from Rose Knob Peak (Mount Rose area) taken just above treeline at 8,860' on a NE aspect showed continued bonding and fewer moderate force shears within the recent storm snow. Wet surface snow was noted on all but true N aspects below 9,000' by 10:00 am. Wet snow instability in the area became widespread with small natural point release avalanches occurring up to 9,000' on E-SE aspects by 11:00 am. Large skier triggered pinwheels were observed up to 9,000' on NE-E-SE aspects at that time. Failure of wet surface snow on 40 degree SE aspect test slopes at 8,500' was observed at 11:30 am. Clear skies overnight are expected to have allowed at least a weak refreeze of surface snow through radiational cooling despite above freezing air temperatures in many locations.

Today, warm air temperatures will create areas of instability on the majority of aspects at all elevations. Air temperature inversion will allow areas of instability to form faster at the upper elevations than if air temperatures had been below freezing overnight. As warm temperatures and solar radiation create free water within the surface snow, small natural point release avalanches and roller ball activity will become possible. Human triggered avalanches large enough to bury or injure a person will be possible today, especially in steep sun exposed areas.

The bottom line: Early this morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE avalanche danger will develop at all elevations on the majority of aspects, 37 degrees and steeper in response to daytime warming.

Please send us your snow, weather, and avalanche observations by clicking the submit observations link on our contact page.

Brandon Schwartz, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 35 deg. F
Max. temperature at Sierra Crest past 24 hours: 48 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 11 mph
Maximum wind gust at Sierra Crest past 24 hours: 34 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 100 inches

Mountain Weather Forecast For Today:
Sunny and warm with high clouds.
Temperature forecast for 8,000 to 9,000 feet: 48 to 54 deg. F
Ridgetop winds forecast for the Sierra Crest: West at 15 to 20 mph with gusts to 30 mph
Snowfall expected in the next 24 hours: 0 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, high cloud cover with daytime highs around 53 deg. F. West winds up to 10 mph.

Tonight, clearing skies with overnight lows around 30 deg. F. Northwest winds at 10 mph shifting to the northeast after midnight.

For Thursday, sunny skies with daytime highs around 50 deg. F. East winds at 10 to 15 mph in the morning, decreasing to less than 10 mph in the afternoon.

Above 8000 Feet:
Today, high cloud cover with daytime highs 48 to 54 deg. F. West winds at 10 to 15 mph with gusts to 30 mph.

Tonight, clearing skies with overnight lows around 30 deg. F. West winds at 10 to 15 mph, shifting to northeast with gusts to 25 mph after midnight.

For Thursday, sunny skies with daytime highs around 47 deg. F. Northeast winds at 10 to 15 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:
	Wednesday:	Wednesday Night:	Thursday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.