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 January 9, 2008 6:51 AM
Click here for a detailed map of the SAC forecast area

2_moderate.jpg
Today's Advisory:
Near and above treeline, avalanche danger is MODERATE on N-NE-E aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW.

Snowfall tapered off during the overnight hours. A weak ridge of high pressure will pass through the forecast area today creating some brief sun breaks this morning before cold cover increases this afternoon. Snow showers are expected to begin during the evening and overnight hours. Ridgetop winds have decrease to moderate speed this morning and are expected to remain moderate today.

Yesterday, moderate to strong southwest winds continued to wind load N-NE-E aspect avalanche start zones. Storm totals are running 10 to 15 inches along the Sierra Crest with around 6 inches of new snow in the Mount Rose area. Air temperatures were fairly warm with this storm. A new snow density of 17% was reported at 7,800' by the Sugar Bowl ski patrol. Significant new snow loading was observed on N-NE-E aspects near treeline on Silver Peak (North of Squaw Peak). Snowpit data and test slope results indicated low force shears within the new snow and near the old/new snow interface. Good snowpack stability was observed within the deeper snowpack below the most recent storm snow. Similar snowpit data was reported from a NE aspect below treeline on Hidden Peak (West Shore Tahoe). Isolated shooting cracks within the new snow, but no test slope failure was reported from this area. Snowpit data from Mt. Rose ski patrol reported good layer bonding at the old/new snow interface and within the new snow in areas not impacted by explosive control work.

As west southwest winds continue to move snow today, recently formed slabs will remain sensitive to human triggered avalanches today. Backcountry travelers should not be surprised by human triggered avalanches in steep wind loaded areas near and above treeline on N-NE-E aspects. Natural avalanche activity is unlikely. Below treeline, natural and human triggered avalanches are unlikely today.

The bottom line: Near and above treeline, avalanche danger is MODERATE on N-NE-E aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW.
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): 19 deg. F
Max. temperature at Sierra Crest past 24 hours: 23 deg. F
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 47 mph
Maximum wind gust at Sierra Crest past 24 hours: 86 mph
New snow fall at 8,200 feet past 24 hours: 10 to 15 inches
Total snow depth at 8,200 feet: 65-75 inches

Mountain Weather Forecast For Today:
Mostly cloudy in the morning, becoming cloudy in the afternoon.
Temperature forecast for 8,000 to 9,000 feet: 24 to 32 deg. F
Ridgetop winds forecast for the Sierra Crest: West southwest at 20 to 30 mph with gusts to 50 mph.
Snowfall expected in the next 24 hours: 2 to 4 inches

2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, mostly cloudy to cloudy skies. Daytime highs 28 to 34 deg. F. Southwest winds at 10 to 15 mph, with gusts to 30 mph.

Tonight, cloudy skies with snow showers. Snow accumulation 2 to 4 inches. Overnight lows around 22 deg. F. Southwest winds at 10 to 15 mph.

For Thursday, mostly cloudy with a chance of snow showers. Daytime highs 32 to 38 deg. F. Southwest winds at 10 to 15 mph with gusts to 30 mph in the afternoon.

Above 8000 Feet:
Today, mostly cloudy to cloudy skies. Daytime highs 24 to 32 deg. F. West southwest winds at 20 to 30 mph, with gusts to 50 mph.

Tonight, cloudy skies with snow showers. Snow accumulation 2 to 4 inches. Overnight lows around 20 deg. F. Southwest winds at 20 to 30 mph with gusts to 60 mph.

For Thursday, mostly cloudy with a chance of snow showers. Daytime highs 29 to 35 deg. F. West winds at 20 to 30 mph with gusts to 60 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.