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 4, 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. Normal caution is advised.

A low pressure system passing through the Pacific Northwest has caused the winds to shift back to the southwest and increase overnight. These winds should continue to gain speed and intensity today. This low pressure should also bring an increase in cloud cover to the forecast area. By late tonight the system should have moved far enough to east that both the winds and cloud cover should start to decrease leaving light winds and clearer skies for Saturday.

The top 1 to 3 inches of surface snow softened by noon yesterday on the southerly aspects in the Mt. Reba area (near Bear Valley) and in the Blue Lakes area (near Carson Pass). This softening created excellent spring corn conditions on these aspects. Observations this week indicate that these spring corn conditions exist on most of the southerly aspects across the forecast area. The snow surfaces that softened yesterday should have undergone a solid refreeze last night due to radiational cooling and below freezing air temperatures. A melt-freeze crust exists on all the other aspects as well. This crust remained frozen on the northerly aspects yesterday. In some areas, shallow pockets of unconsolidated snow sit on top of this melt-freeze crust. The warm air and sunny skies will quickly change this snow into melt/freeze snow and assimilate it into the snowpack. Recent snowpit data indicates that the deeper snowpack consists of dense layers that are well bonded to one another on all aspects and at all elevations.

Today, warmer air temperatures and solar radiation will melt snow in sun exposed areas at all elevations. The greatest amount of melting will occur on E-SE-S-SW-W aspects. Well formed melt water pathways, a solid overnight refreeze, and an increase in cloud cover should all help to limit the soft, wet snow to the top few inches of the snowpack. Any areas of wet snow instability that form today are not expected to present a significant hazard to backcountry travelers. Natural and human triggered avalanches remain unlikely at this time.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Normal caution is advised.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 27 deg. F
Max. temperature at Sierra Crest past 24 hours: 45 deg. F.
Average wind direction at Sierra Crest past 24 hours: Northeast shifting to the southwest
Average wind speed at Sierra Crest past 24 hours: 15 mph
Maximum wind gust at Sierra Crest past 24 hours: 37 mph
New snowfall at 8,200 feet past 24 hours: 0 inches
Total snow depth at 8,200 feet: 77 inches
Mountain Weather Forecast For Today:
Partly cloudy with more clouds developing this evening.
Temperature forecast for 8,000 to 9,000 feet: 34 to 44 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 15 to 25 mph with gusts to 40 mph increasing to 30 to 40 mph with gusts to 60 mph.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:

Today, partly cloudy skies with daytime highs 42 to 52 deg. F. South winds at 10 mph shifting to the southwest and increasing to 15 to 25 mph with gusts to 40 mph.

Tonight, mostly cloudy skies in the evening then some clearing after midnight. Overnight lows 25 to 33 deg. F. Southwest winds at 15 to 25 mph with gusts to 45 mph decreasing to 10 to 15 mph with gusts to 30 mph after midnight.

For Saturday, partly cloudy with daytime highs 40 to 50 deg. F. Southwest winds at 10 to 15 mph.

Above 8000 Feet:
Today, partly cloudy skies with daytime highs 34 to 44 deg. F. Southwest winds at 15 to 25 mph with gusts to 40 mph increasing to 30 to 40 mph with gusts to 60 mph.

Tonight, mostly cloudy skies in the evening then some clearing after midnight. Overnight lows 21 to 31 deg. F. Southwest winds at 25 to 40 mph with gusts to 65 mph.

For Saturday, partly cloudy with daytime highs 32 to 42 deg. F. Southwest winds at 10 to 15 mph with gusts to 30 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:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.