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.

A temperature inversion exists across the forecast area again this morning with temperatures above 7000 ft. much warmer than those in the mountain valleys. The high pressure ridge over the region should keep the weather mostly clear and dry again today. This high pressure should begin to move out of the area today. The winds and cloud cover should increase this afternoon ahead of a low pressure system forecasted to hit the forecast area tonight. Even though this system should split causing most of its energy to go around the Tahoe region, the forecast calls for this low pressure to bring strong southwest winds and some snow to the area. Along the Sierra Crest 2-7 inches could accumulate by tomorrow afternoon before the storm departs. Areas south of Hwy 50 should see the largest accumulations. 

Recent Observations:

On Maggies Peak (more info), near Stanford Rocks (video, photos, more info), and in the Mt. Rose Wilderness (photos, snowpit, more info) yesterday, observations and data continued to point to a strong and stable upper snowpack with a wide 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 that melted into wet sticky snow on sun-exposed E-SE-S-SW aspects. Patches of surface hoar had also formed in some of the more sheltered below treeline areas. Ski cuts on test slopes, handpits, snowpit data, and general observations 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. 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. If they do start to collapse, the resulting fracture could travel along the weak layer.

Snowpack Concerns: Wind Slabs and Persistent Deep Slabs

On a regional scale, avalanche activity caused by a single skier, snowboarder, or snowmobiler remains 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 deeply buried persistent weak layers have become dormant due to the strong snow on above them that insulates those layers from forces applied to the snow surface. Triggering persistent deep slabs has become unlikely for this reason. 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. Areas of unstable snow might exist on isolated terrain features. 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:	25-33 deg. F.
Max. temperature in the last 24 hours:	37-43 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	10-20 mph
Maximum wind gust in the last 24 hours:	36 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	60-86 inches

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

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Partly cloudy becoming mostly cloudy later in the day	Cloudy with a chance of snow in the evening. Snow becoming likely after midnight.	Snow
Temperatures:	35-42 deg. F.	11-18 deg. F.	19-26 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	15-20 mph with gusts to 30 mph increasing to 35-40 mph with gusts to 60 mph in the afternoon	35-40 mph with gusts to 60 mph decreasing to 25-30 mph with gusts to 40 mph after midnight	20-30 mph with gusts up to 40 mph
Expected snowfall:	O in.	up to 2 in.	2-3 in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Partly cloudy becoming mostly cloudy later in the day	Cloudy with a chance of snow in the evening. Snow becoming likely after midnight.	Snow
Temperatures:	31-38 deg. F.	7-14 deg. F.	13-20 deg. F.
Wind direction:	Southwest	Southwest	Southwest shifting to west in the afternoon
Wind speed:	20-25 mph with gusts to 35 mph increasing to 40-45 mph with gusts to 65 mph in the afternoon	35-45 mph with gusts to 65 mph	35-40 mph with gusts to 60 mph decreasing to 25-30 mph with gusts to 45 mph in the afternoon
Expected snowfall:	O in.	up to 2 in.	2-5 in.