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 14th, 2007 at 6:46 am

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. This afternoon, new snowfall is expected to create isolated pockets of MODERATE avalanche danger near and above treeline on wind loaded N-NE-E aspects, 37 degrees and steeper.

A splitting weather system is expected to impact the forecast area today. Ridgetop winds have shifted to westsouthwesterly overnight ahead of the approaching weather system. Snow level is expected to begin around 5,500' and lower to around 4,000' this afternoon. Ridgetop winds are expected to increase in speed this morning, as the weather system moves into the area. Low snowfall rates are expected with this system. Snow showers are expected to linger overnight before clearing skies occur on Sunday. Winds are expected to shift to northeasterly Sunday morning.

Ridgetop winds have shifted all the way around the compass since Thursday morning. This a scoured new snow from last Wednesday out of avalanche start zone above treeline. Warming air temperatures late Thursday and on Friday have created areas of melt-freeze crust on the snow surface in many areas on all aspects. Pockets of settled but unconsolidated snow exist in wind protected areas at the upper elevations. The combination of wind scouring, melt-freeze, and settlement has created a stable snowpack in all areas this morning.

New snowfall amounts of 3-6" are expected from today's weather system. As new snow begins to accumulate later today, some isolated pockets of new soft slab formation are expected near and above treeline on wind loaded N-NE-E aspects. These slabs are expected to remain shallow and limited to only the top portion of avalanche start zones. If the lower end of expected snowfall accumulation occurs, any pockets of snow surface instability that form are not expected to cause significant hazard to backcountry travelers. If the upper end of expected snowfall accumulation is reached, human triggered avalanches that occur on slopes with secondary exposure (such as terrain traps or above cliff bands) will create a significant hazard to backcountry travelers late today through early tomorrow morning on steep N-NE-E aspects.

Isolated human triggered avalanches are expected to become possible by late today in wind loaded areas near and above treeline on N-NE-E aspects, 37 degrees and steeper. Areas of instability are expected to limit to small isolated pockets rather than entire slopes. Natural avalanches are unlikely today.

The bottom line: This morning, avalanche danger is LOW for all elevations and aspects. This afternoon, new snowfall is expected to create isolated pockets of MODERATE avalanche danger near and above treeline on wind loaded N-NE-E aspects, 37 degrees and steeper.

We will raffle a BCA backpack, beacon, shovel, and probe package on April 17th as a way to say thanks to everyone who has sent us a donation in the mail or via Pay Pal this season. All individuals who have donated $10 or more to SAC are automatically entered in this raffle. Thanks to all of our sponsors, the ski days, and everyone who has donated funding this winter, we have met our operating budget for this season and have a start on next year's funding. For more details about our financial situation please click here.

Brandon Schwartz, 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: 46 deg. F
Average wind direction at Sierra Crest past 24 hours: Easterly shifting to westsouthwesterly
Average wind speed at Sierra Crest past 24 hours: 24 mph
Maximum wind gust at Sierra Crest past 24 hours: 58 mph
New snow fall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 56 inches

--------------------------------------------------------------------------------
Mountain Weather Forecast For Today:
Cloudy skies with light snow.
Temperature forecast for 8,000 to 9,000 feet: 31-39 degrees F.
Ridgetop winds forecast for the Sierra Crest: Westsouthwesterly 50-60 mph, gusting to 70 mph
Snowfall expected in the next 24 hours: 3-6 inches

--------------------------------------------------------------------------------
2 Day Mountain Weather Forecast:
7000 to 8000 Feet:
Today, cloudy skies with scattered snow showers in the morning. Light snowfall in the afternoon. Snow accumulation 1-4". Daytime highs 37 to 43 degrees F. Southwest winds at 35 to 45 mph. Tonight, cloudy with scattered snow showers. Snow accumulation up to 2". Overnight lows around 22 degrees F. West winds at 15 to 20 mph. Sunday, mostly to partly cloudy skies with a slight chance of snow showers in the morning. Daytime highs 36 to 42 degrees F. Northeast winds at 30 to 45 mph are expected.

Above 8000 Feet:
Today, cloudy skies with numerous snow showers in the morning. Light snowfall in the afternoon. Snow accumulation 1-4". Daytime highs 31 to 39 degrees F. Westsouthwest winds at 50 to 60 mph, gusting to 70 mph in the morning. Tonight, cloudy with scattered snow showers. Snow accumulation up to 2". Overnight lows around 17 degrees F. Southwest winds at 15 to 25 mph with gusts to 50 mph. Sunday, mostly to partly cloudy skies with a slight chance of snow showers in the morning. Daytime highs 29 to 39 degrees F. Northeast winds at 30 to 40 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.