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 April 17, 2008 7:00 AM

A map of the SAC forecast area is available on our home page.

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Today's Advisory:

Avalanche danger is LOW for all elevations and aspects. Some small, isolated areas of MODERATE danger could develop on sun exposed SE-S-SW aspects steeper than 38 degrees due to daytime warming.

Overnight temperatures started to warm up due to the high pressure ridge over the forecast area. They should continue to climb today reaching the low 60's below 8000' and the mid 50's above 8000'. The winds should shift to the southwest and increase due to an approaching low pressure system today. By tomorrow the forecast area should see windier, cloudier, and slightly cooler weather.

Even though high temperatures reached the mid 40's above 8000', most northerly aspects stayed frozen for the majority of yesterday. The top 2 to 3 inches of surface snow softened on SE-S-SW aspects on Red Lake Peak near Carson Pass by mid afternoon due to the intense solar radiation. The clear skies and overnight temperatures below freezing should have allowed another solid refreeze to occur in the snowpack.

Today, sunshine and warmer air temperatures will cause the surface snow to soften and melt much faster on any sun exposed slopes. The most melting should occur on E-SE-S-SW-W aspects where some isolated areas of wet snow instability could develop. The the solid refreeze that adds strength to the snowpack and well established drainage channels that prevent the newly formed free water from pooling at a specific layer should keep these instabilities small and limited to human triggered point release sluffs. Large wet slab avalanche activity should remain unlikely but not impossible in areas where the snowpack sits on an impermeable ground surface like a granite slab. Natural avalanches are unlikely at this time.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Some small, isolated areas of MODERATE danger could develop on sun exposed SE-S-SW aspects steeper than 38 degrees due to daytime warming.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 31 deg. F
Max. temperature at Sierra Crest past 24 hours: 41 to 45 deg. F.
Average wind direction at Sierra Crest past 24 hours: East northeast
Average wind speed at Sierra Crest past 24 hours: 20 mph
Maximum wind gust at Sierra Crest past 24 hours: 57 mph
New snowfall at 8,200 feet past 24 hours: 0
Total snow depth at 8,200 feet: 67 inches
Mountain Weather Forecast For Today:
Sunny and warmer.
Temperature forecast for 8,000 to 9,000 feet: 48 to 56 deg. F
Ridgetop winds forecast for the Sierra Crest: East at 15 to 30 mph shifting to the southwest at 10 to 20 mph this afternoon.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:

Today, sunny skies with daytime highs 55 to 61 deg. F. East winds at 10 to 20 mph shifting to the southwest this afternoon.

Tonight, clear skies with overnight lows around 33 deg. F. Southwest winds at 10 to 20 mph.

For Friday, partly cloudy skies with daytime highs 52 to 58 deg. F. Southwest winds at 10 to 20 mph with gusts to 30 mph.

Above 8000 Feet:

Today, sunny skies with daytime highs 48 to 56 deg. F. East winds at 15 to 30 mph shifting to the southwest at 10 to 20 mph this afternoon.

Tonight, clear skies with overnight lows around 31 deg. F. Southwest winds at 15 to 25 mph with gusts to 40 mph.

For Friday, partly cloudy skies with daytime highs 46 to 52 deg. F. Southwest winds at 15 to 25 mph with gusts to 40 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:
	Thursday:	Thursday Night:	Friday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Thursday:	Thursday Night:	Friday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.