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 19, 2008 7:00 AM
Click here for a detailed map of the SAC forecast area

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Today's Advisory:

Avalanche danger is LOW for all elevations and aspects. Normal caution is advised.

The northeast flow has started shifting to the south and west ahead of a small system approaching the forecast area. Temperatures should be warmer today than they have been all week with highs reaching the mid to upper 30's above 8000' and the upper 30's to low 40's at the lower elevations. The winds should be much calmer toady as they shift to the south and west. They should increase again as the cold front reaches the forecast area tonight. This front only has a small amount of moisture associated with it and new snow totals should be small.

As temperatures rise today, some softening should occur on sun exposed aspects above 8000' and on most aspects below 8000'. The forecasted afternoon cloud cover, shortness of the daytime hours (leading to less exposure to the sun), low sun angles, and prolonged hard refreeze should keep this warming from creating significant wet snow instabilities. The melting and softening should be limited to the surface snow. Some small roller balls and pinwheels may form today on sun exposed aspects. If the temperatures climb higher than forecast or the cloud cover does not materialize wet snow instabilities like wet point release activity and larger pinwheels could become more widespread today. This warming should help to destroy some of the surface hoar that exists in the forecast area. In addition to sheltered areas below treeline near Donner Pass, north of Squaw in the Silver Peak area, and in the Mount Rose area, observers reported surface hoar in the Luther Pass and Judah Peak areas yesterday. If it does not get destroyed before the next storm, this layer could become a buried persistent weak layer that could cause problems when more snow falls on the forecast area. It is a great time to go check out your favorite backcountry stash to see what is happening on the surface and below the surface in the snowpack. Observations continue to show a well bonded snowpack exists below the surface throughout the forecast area.

The surface of this snowpack is a mix of wind scoured hard pack, melt-freeze crusts, and some pockets of unconsolidated snow on the more sheltered northerly aspects. Wind protected N-NW aspects above 9000' have the most continuous and consistent areas of this unconsolidated snow. The riding in these areas remains nice.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Normal caution is advised.
Please send us your snow, weather, and avalanche observations by clicking the submit observations link on our contact page.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 28 deg. F
Max. temperature at Sierra Crest past 24 hours: 32 deg. F
Average wind direction at Sierra Crest past 24 hours: East shifting to the south and west
Average wind speed at Sierra Crest past 24 hours: 28 mph
Maximum wind gust at Sierra Crest past 24 hours: 61 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 54 inches
Mountain Weather Forecast For Today:
Sunny in the morning becoming partly cloudy this afternoon.
Temperature forecast for 8,000 to 9,000 feet: around 37 deg. F
Ridgetop winds forecast for the Sierra Crest: Southeast at 10 mph with gusts to 25 mph in the morning increasing to west winds at 15 to 25 mph with gusts to 40 mph in the afternoon.
Snowfall expected in the next 24 hours: 1-3 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, sunny in the morning becoming partly cloudy this afternoon. Daytime highs around 41 deg. F. Southeast winds at 10 mph in the morning shifting to the southwest in the afternoon.

Tonight, mostly cloudy skies with overnight lows around 25 deg. F. Southwest winds at 10 to 15 mph with gusts to 30 mph.

For Sunday, cloudy skies with a chance of snow. Accumulation should be less than 1 inch. Daytime highs around 31 deg. F. West winds at 10 to 20 mph.

Above 8000 Feet:
Today, sunny in the morning becoming partly cloudy this afternoon. Daytime highs around 37 deg. F. Southeast winds at 10 mph with gusts to 25 mph in the morning increasing to west winds at 15 to 25 mph with gusts to 40 mph in the afternoon.

Tonight, mostly cloudy skies with overnight lows around 25 deg. F. West winds at 20 to 35 mph with gusts to 70 mph.

For Sunday, cloudy skies with a chance of snow. Accumulation should be less than 2 inches. Daytime highs around 28 deg. F. West winds at 15 to 25 mph with gusts to 45 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:
	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.