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.

Snow levels remain between 7000' and 7500' with more rain expected below 7500' this morning. A colder low pressure system pushing southward from the Pacific Northwest should cause freezing levels to drop to Lake level by this afternoon. Depending on the timing of this drop in freezing level, 2-4 inches of snow could fall below 7500' this afternoon. Above 7500' the forecast area could receive 4-6 inches of new snow today. The forecast calls for snow showers to taper off tonight before another cold front impacts the forecast area starting tomorrow bringing colder temperatures and more snow. The southwest winds should remain moderate today before increasing overnight.

Liquid totals for this storm ranged from about 2" along the Sierra Crest to 1.6" east of the Lake. Above 8500' most of this precipitation fell as snow adding 12" of snow in the Mount Rose area and up to 18" along the highest elevations on the Sierra Crest. Between 7500' and 8500' this precipitation fell as a mix of rain and snow. Below 7500' the precipitation has been mostly rain. Yesterday, observations from the Carson Pass area and the Mt. Judah area showed rain falling on 2-6 inches of new snow below 8500'. This rain on new snow resulted in several natural and skier-triggered, wet, point-release slides and ski-width sluffs on slopes steeper than 35 degrees. These wet slides entrained all the new snow and slid on the interface between the new and old snow. Layer bonding tests in the Mt. Judah area indicated that the bond between the wet, new snow and the old snow surfaces has made some minor gains in strength.

Today, the wet, new snow should start to refreeze and gain strength as the freezing level drops. Small new snow amounts and moderate winds should cause less wind slab formation. Even though these factors will help the snowpack adjust to its new load and to gain some strength, two avalanche concerns still exist for today.

The first concern will be newly formed wind slabs on NW-N-NE-E-SE aspects. These wind slabs will be largest and easiest to trigger on the N-NE-E aspects above 8500'; however, some smaller wind slabs could form on slopes between 7500' and 8500' on open, wind-exposed terrain. These wind slabs sit on a mix of surface crusts and facets. Human triggering of these avalanches will be possible today.

The second, more uncertain avalanche concern will result from rain adding weight and lubrication to the snowpack below 7500'. Over 2 inches of rain fell during this storm in some areas. Another .25-.5 inch of rain is expected below 7500' this morning. This water will dissolve bonds that currently hold the snowpack together. If it saturates the snowpack and dissolves enough of those bonds, natural and human-triggered, wet avalanches could be possible again today.

The bottom line:

Above 7500' the avalanche danger is MODERATE with pockets of CONSIDERABLE danger above 8500' on N-NE-E aspects 35 degrees and steeper. Below 7500' the avalanche danger is MODERATE on all aspects 35 degrees and steeper.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	29 deg. F.
Max. temperature in the last 24 hours:	35 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	20 mph
Maximum wind gust in the last 24 hours:	54 mph
New snowfall in the last 24 hours:	4-6 inches
Total snow depth:	66 inches

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

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	A mix of rain and snow in the morning changing to snow by the afternoon. Freezing levels 7500 ft this morning dropping to Lake level by this afternoon.	Cloudy with scattered snow showers	Snow showers
Temperatures:	26-33 deg. F.	18-25 deg. F.	20-27 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	10-15 mph with gusts to 25 mph	10-15 mph with gusts to 25 mph	10-15 mph with gusts to 25 mph
Expected snowfall:	2-4 in.	trace in.	2-4 in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Snow showers	Cloudy with scattered snow showers	Snow showers
Temperatures:	27-33 deg. F.	13-20 deg. F.	18-24 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	15-25 mph with gusts to 45 mph	20-30 mph with gusts to 60 mph	20-30 mph with gusts to 50 mph
Expected snowfall:	4-6 in.	trace in.	3-5 in.