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.

Temperatures dropped below freezing at the higher elevations and very close to freezing at most of the lower elevations last night. The winds shifted more to the southwest and have started to pull warm air into the region. The forecast calls for one more warm day with daytime highs in the mid to upper 40's above 7000 ft. today. The winds should continue from the southwest and clouds should increase as a low pressure approaches from the Gulf of Alaska. By tonight temperatures should drop well below freezing and some snow showers should begin. The snow should continue through Sunday with the forecast calling for 4-8 inches of new snow above 7000 ft (weather graphic from the NWS). This system will also bring a mass of cold air to the forecast area. Daytime highs above 7000 ft tomorrow should only reach into the mid 20's.

Observations:

Observations from Waterhouse Peak yesterday showed melt-freeze and variable crust conditions similar to those seen across the forecast area during this week. A strong refreeze occurred on Thursday night in this area. During the day yesterday enough warming occurred for a few inches of soft corn snow to form on top of a thick, strong, refrozen melt-freeze crust on the sunny SE-S-SW aspects up to 9200 ft by noon (video). On less sunny northerly aspects, a thinner, sometimes-breakable, sometimes-supportable crust existed with a layer of video).  E aspects held some of both of these conditions depending on how much sun they received. Ski cuts and hand pits on all these aspects did not show any signs of instability.

Avalanche Concerns:

The snow that melted and softened yesterday should have refrozen well last night due to the combination of overnight lows close to and below freezing and clear skies that allowed the snowpack to radiate heat into space until the clouds moved in early this morning. Slightly cooler temperatures and more widespread cloud cover today should limit the melting that occurs. Less melting means less chance for wet snow instabilities to form, but it also means more hard and frozen snow surfaces. If more melting occurs than expected, some wet snow instabilities may become possible in isolated areas on the warmest aspects. Over the next 24 hours as winter returns to the forecast area and new snow starts to fall on the frozen crusts and the thin breakable crusts with weak snow below them, the avalanche danger will increase.

The bottom line:

The avalanche danger should remain LOW for all elevations and aspects for most of the day. Use normal caution when traveling in the backcountry.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature:	29-32 deg. F.
Max. temperature in the last 24 hours:	42-50 deg. F.
Average wind direction during the last 24 hours:	West southwest
Average wind speed during the last 24 hours:	20 mph
Maximum wind gust in the last 24 hours:	42 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	58-87 inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Partly cloudy this morning becoming mostly cloudy this afternoon	Cloudy with snow showers. Snow showers becoming more widespread after midnight.	Snow showers
Temperatures:	44-50 deg. F.	14-21 deg. F.	18-25 deg. F.
Wind direction:	Southwest	Southwest	West shifting to the north in the afternoon
Wind speed:	10-20 mph with gusts to 35 mph	10-20 mph with gusts to 45 mph	10-15 mph with gusts to 35 mph
Expected snowfall:	O in.	up to 2 in.	3-6 in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Partly cloudy this morning becoming mostly cloudy this afternoon	Cloudy with snow showers. Snow showers becoming more widespread after midnight.	Snow showers
Temperatures:	37-44 deg. F.	15-21 deg. F.	13-20 deg. F.
Wind direction:	Southwest	Southwest	West shifting to the north in the afternoon
Wind speed:	20-30 mph with gusts to 50 mph	20-35 mph with gusts to 50 mph	20-30 mph with gusts to 45 mph decreasing to 10-20 mph with gusts to 35 mph in the afternoon
Expected snowfall:	O in.	up to 2 in.	3-6 in.