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 Saturday, April 21st, 2007 at 6:48 am

The bottom line: Avalanche danger is LOW for all elevations and aspects. Avalanche danger will increase very late today and overnight into Sunday.

A moderately strong pacific storm system is approaching the forecast area. Cloudy skies with snow showers developing by late afternoon are expected for today. Ridgetop winds shifted from moderate easterly to light westerly late yesterday afternoon. A period of very light to calm winds occurred overnight. Increasing westsouthwesterly winds have been observed this morning ahead of the approaching storm. This storm system has tapped into subtropical moisture, which will prevent low snow levels. Snow level is expected to begin around 6,000-6,500' this evening before falling to near 5,500' overnight. At this time, 10-20 inches of snowfall and moderate to strong ridgetop winds are expected at the 8,000' level from this storm system.

A stable snowpack currently exists within the forecast area. Snow surface conditions in most areas consist of either wind scoured melt-freeze crust, or shallow, unconsolidated snow on top of melt-freeze crust. Many exposed rocks and down trees exist beneath a light cover of snow. Travel with caution.

Any avalanche activity that occurs overnight tonight or on Sunday is expected to involve only new snow from the approaching storm. Anticipated snowpack failure during the storm is expected to occur at or above the existing melt-freeze crust. Snowpack failure occurring below the height of the uppermost melt-freeze crust in the snowpack is not expected at this time.

Natural and human triggered avalanche activity is unlikely today. Very small and isolated human triggered avalanches are unlikely but not impossible in recently wind loaded areas above treeline. Any lingering areas of instability that may exist today are not expected to be larger enough to present a hazard to backcountry travelers.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Avalanche danger will increase very late today and overnight into Sunday.

We are working with a very limited number of observations at this time of year. Due to decreased numbers of observations and waning backcountry interest, we will begin to scale back operations this Sunday, April 22nd. We plan to end operations for the season on April 28th.

Thank you to all of our sponsors, those individuals who purchased tickets for the SAC Ski Day fundraising events, and everyone else who donated funding this winter. We have met our operating budget for this season and have a solid start on next year's funding. For more details about our financial situation please click here.

Brandon Schwartz, Avalanche Forecaster

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Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 23 deg. F
Max. temperature at Sierra Crest past 24 hours: 39 deg. F
Average wind direction at Sierra Crest past 24 hours: easterly shifting to westsouthwesterly
Average wind speed at Sierra Crest past 24 hours: 15 mph
Maximum wind gust at Sierra Crest past 24 hours: 39 mph
New snow fall at 8,200 feet past 24 hours: trace - 2 inches
Total snow depth at 8,200 feet: 56 inches

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Mountain Weather Forecast For Today:
Cloudy skies with snow showers in the afternoon
Temperature forecast for 8,000 to 9,000 feet: 28 - 34 degrees F.
Ridgetop winds forecast for the Sierra Crest: Westsouthwesterly 25 - 35 mph, gusting to 60 mph in the afternoon.
Snowfall expected in the next 24 hours: 6 - 10 inches

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2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, cloudy skies with scattered snow showers in the afternoon. Daytime highs 34 to 44 degrees F. Southwest winds at 10 to 20 mph, gusting to 30 mph. Tonight, cloudy skies with snow. Snow accumulation 6 to 10 inches. Overnight lows 24 to 29 degrees F. Southwest winds at 15 to 25 mph. Sunday, cloudy with snow. Snow accumulation 5 to 10 inches. Daytime highs 34 to 42 degrees F. West winds at 10 to 20 mph are expected.

Above 8000 Feet:
Today, cloudy with scattered snow showers in the afternoon. Daytime highs 28 to 34 degrees F. Southwest winds at 10 to 20 mph, increasing to 25 to 35 mph with gusts to 60 mph in the afternoon. Tonight, cloudy with snow. Snow accumulation 6 to 10 inches. Overnight lows 22 to 27 degrees F. Southwest winds at 40 to 50 mph, gusting to 80 mph. Sunday, cloudy with snow. Snow accumulation 5 to 10 inches. Daytime highs 27 to 35 degrees F. West winds at 25 to 35 mph, gusting 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:
	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.