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 Monday, February 19th, 2007 at 6:40 am

The bottom line: Avalanche danger is LOW for all elevations and aspects. Some very small and isolated pockets of shallow surface instability exist in the Carson Pass and Luther Pass areas. These pockets of instability exist in wind loaded areas above treeline on SW-W-NW aspects, 35 degrees and steeper. These areas are not expected to present a significant hazard to backcountry travelers during the next 24 hours.

A few clouds remain over the forecast area this morning. Clearing is expected as the day progresses and drier air moves into the area. Ridgetop winds shifted from westsouthwesterly to easterly overnight. Winds speeds are expected to decrease today during the afternoon hours. A short period of high pressure is expected to build over the forecast area ahead to the next approaching storm system, currently expected to impact the forecast area beginning Wednesday night.

Most locations throughout the forecast area received around 1 inch of new snow yesterday and experienced continued melt-freeze surface conditions on all aspects below 8,500'. The exception was a localized area of greater snowfall that was observed in the Carson Pass and Luther Pass areas. In this area, 5 inches of new snow accumulated during the morning and early afternoon hours. Some very small skier triggered sluffs were reported in this area above treeline on NW-N-NE aspects, 35 degrees and steeper yesterday afternoon.

Easterly ridgetop winds last night and today will create areas of new wind loading on SW-W-NW aspects today in the Carson Pass and Luther Pass area, where the new snow from yesterday is available for wind transport. Very small and shallow human triggered sluffs and wind slabs are possible above treeline on SW-W-NW aspects, 35 degrees and steeper. For the remainder of the forecast area where minimal new snowfall was observed, any avalanche activity is unlikely today. Yesterday, continued increases in layer bond strength within the existing deeper snowpack were observed throughout the forecast area. No areas deep slab instability are expected at this time.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Some very small and isolated pockets of shallow surface instability exist in the Carson Pass and Luther Pass areas. These pockets of instability exist in heavily wind loaded areas above treeline on SW-W-NW aspects, 35 degrees and steeper. These areas are not expected to present a significant hazard to backcountry travelers during the next 24 hours.

At this time, we are still short $8,000 in funding for our operating budget this winter. If you use this service with any regularity and would like to continue to do so, please show your financial support for the Sierra Avalanche Center. You may make a tax deductible donation directly to us via Paypal or by sending a check to our address listed above, c/o the Truckee Ranger Station. A financial graph showing the amount of fundraising completed this season and our overall budget is available by clicking here. The financial support already received this winter from a variety of users is greatly appreciated.

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 16 deg. F
Max. temperature at Sierra Crest past 24 hours: 39 deg. F
Average wind direction at Sierra Crest past 24 hours: westsouthwesterly, shifting to easterly
Average wind speed at Sierra Crest past 24 hours: 28 mph
Maximum wind gust at Sierra Crest past 24 hours: 47 mph
New snow fall at 8,200 feet past 24 hours: 1 - 5 inches
Total snow depth at 8,200 feet: 51 inches

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Mountain Weather Forecast For Today:
Partly cloudy skies.
Temperature forecast for 8,000 to 9,000 feet: 29 - 34 deg. F.
Ridgetop winds forecast for the Sierra Crest: easterly 20 - 30 mph, gusting to 40 mph, decreasing to 10 mph in the afternoon
Snowfall expected in the next 24 hours: 0 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet
Today, partly cloudy skies with daytime highs 35 to 40 degrees F. Northeast winds at 10 to 20 mph, decreasing to 5 to 10 mph in the afternoon. Tonight, clear skies with lows 27 to 32 degrees F. Light winds becoming southwest around 10 mph after midnight. Tuesday, partly cloudy skies with daytime highs 37 to 42 degrees F. Southwest winds at 15 to 25 mph, gusting to 40 mph are expected.

Above 8000 Feet
Today, partly cloudy skies with daytime highs 29 to 34 degrees F. East winds at 20 to 30 mph, gusting to 40 mph, decreasing to 10 mph in the afternoon. Tonight, clear skies with lows 27 to 32 degrees F. East winds at 5 to 10 mph, shifting to southwest 10 to 20 mph after midnight. Tuesday, partly cloudy skies with daytime highs 31 to 36 degrees F. Southwest winds at 20 to 35 mph with gusts to 60 mph are expected.

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.