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.

Similar to yesterday an inversion exists across the forecast area with temperatures below 7000 ft. much colder than those above 7000 ft. Currently remote sensors above 7000 ft. indicate temperatures in the upper 20's and low 30's. As the day warms up, mountain temperatures should climb into the upper 30's to low 40's. The winds should remain light, and skies should remain mostly clear as the high pressure ridge over the forecast area continues to dictate the weather. A few clouds could start to move into the region today. By tomorrow the winds and clouds should begin to increase ahead of a weak system forecasted to reach the area on Sunday.

Recent Observations:

Observations across the forecast area indicate continued settlement and consolidation above the Dec. rain crust. On Echo Summit (more info), in the Deep Creek drainage (more info), on Donner Peak (photos, snowpit, more info), and on Mt. Judah yesterday, reports showed a variety of surface conditions. These included soft unconsolidated snow on sheltered NW-N-NE aspects, wind scoured and wind buffed surfaces on exposed near and above treeline slopes, and thin breakable sun crusts and some wet snow on sun-exposed E-SE-S-SW aspects. Patches of surface hoar had also formed in the more sheltered below treeline areas in all three of these places. Ski cuts on test slopes, handpits, snowpit data, and small cornice pieces dropped onto steep slopes did not reveal any signs of significant instability within the upper snowpack yesterday.

Over the last several days, data regarding the Dec. facet layers has shown that these deeper persistent weak layers remain weak. If they do start to collapse, the resulting fracture could travel along the weak layer. The data also indicates that transmitting enough force through the snowpack to actually break these layers has become more difficult due to the strong snow above these old weaknesses.

Snowpack Concerns: Wind Slabs and Persistent Deep Slabs

On a regional scale, avalanche activity caused by a single skier, snowboarder, or snowmobiler has become unlikely. Some areas of unstable snow could still lurk in complex or extreme terrain in and around steep chutes, gullies, couloirs, cliffs and rock bands especially in wind loaded areas. The strong snow on top of the persistent weak layers continues to insulate those layers from forces applied to the snow surface meaning that triggering persistent deep slabs has also become unlikely. Triggers larger than a single person recreating on a slope such as multiple people close together on the same slope, very large cornice collapses, or other avalanches might still provide the force needed to cause a deep slab failure.  If such a failure does occur, avalanches with catastrophic consequences would result.

Continue to exercise good travel techniques like moving one at time from safe zone to safe zone while in avalanche terrain. Soft snow and a sense of stability can easily impair judgment and create unsafe situations.

The bottom line:

Avalanche danger remains LOW for all elevations and aspects. During LOW danger avalanches are unlikely but not impossible. Isolated areas of unstable snow may exist in complex or extreme terrain in and around areas of chutes, gullies, cliffs, and exposed rocks. Continue to use normal caution when travelling 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:	34-44 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	15-20 mph
Maximum wind gust in the last 24 hours:	40 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	61-87 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy	Partly cloudy	Partly cloudy
Temperatures:	40-46 deg. F.	14-24 deg. F.	35-42 deg. F.
Wind direction:	Variable	Variable	Southwest
Wind speed:	Light	Light	15-20 mph with gusts to 30 mph increasing to 25-35 mph with gusts to 45 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Partly cloudy	Partly cloudy	Partly cloudy
Temperatures:	37-43 deg. F.	23-31 deg. F.	33-40 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	10-15 mph	10-15 mph	20-25 mph with gusts to 35 mph increasing to 35-45 mph with gusts to 60 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.