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 low pressure passing north of the forecast area caused the southwest winds to increase overnight. Wind speeds averaged between 35 mph and 50 mph for much of the night. As the cold front associated with this low pressure moves through the region this morning, the winds should decrease. Temperatures should remain cooler today than yesterday with highs only reaching in to the mid to upper 30's above 7000 ft.  The chances for precipitation and cloud cover stayed farther north with the main part of this system. The forecast calls for a cold and mostly clear night tonight before clouds and winds start to increase tomorrow due to a second low pressure system approaching the area. Tomorrow's daytime highs should remain even cooler than today's with temperatures topping out in the upper 20's and low 30's.

Recent Observations:

Similar to other places across the forecast area, observations yesterday on Becker Peak (snowpit, more info) and on Relay Peak (photos, more info) showed a wide variety of snow conditions. The warm temperatures and sunshine allowed several inches of soft wet snow to form on the sun-exposed southerly aspects in both of these areas. A supportable layer of firm melt-freeze snow existed below this wet surface snow on most slopes. Below 9500 ft on Relay Peak and below 7700 ft on Becker Peak, the snow on these aspects became "punchy" and wet. Below 9000 ft on Relay Peak and below 7500 ft on Becker Peak, snow coverage became patchy on these southerly aspects. In both of these areas, only small inconsequential roller balls occurred on the southerly aspects. Some sheltered upper elevation NW aspects on Relay Peak held soft unconsolidated snow, while scoured surfaces and more firm snow existed on the more exposed northerly aspects. On the northerly aspects on Becker Peak, the warm temperatures had melted the breakable crust leaving behind heavy wet snow on top of softer drier snow. Snowpits, hand pits, and pole probes showed that the crust/facet combination still lurks beneath the recent snow on the northerly aspects on Becker Peak. Several Extended Column Tests showed that a fracture traveling very far through this layer remains unlikely; however, one ECT did indicate this possibility. This data shows that the crust/facet combination remains weak and variable, but that the areas where fractures can travel any distance through this layer remain few and far between.

Today's Primary Avalanche Concern:  Persistent Slabs

The persistent weak layer made up of faceted snow and crusts at the base of the recent snow still exists; however, data collected over the last week seems to indicate that it has become dormant. This weak layer has not gone away. It could re-awaken with the arrival of new loading, or it could start to lose strength again. Even though triggering avalanches has become more unlikely on near or below treeline NW-N-NE aspects, unlikely does not mean impossible. Persistent weak layers like this one warrant extra caution and constant monitoring. Continue to use caution and exercise good travel habits in order to minimize risk.

Cooler daytime highs and moderate winds along with a strong overnight refreeze and several days of melt freeze cycles should keep significant wet snow instabilities from forming today. Some softening may occur on the sun-exposed SE-S-SW aspects. This softening should remain shallow and short-lived, and some slopes may remain firm for most of the day.

The bottom line:

The avalanche danger remains LOW for all elevations and aspects. LOW danger does not mean no danger. Continue to 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:	20-32 deg. F.
Max. temperature in the last 24 hours:	43-52 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	30-40 mph
Maximum wind gust in the last 24 hours:	Along the Sierra Crest: 66 mph | In the Mt Rose area: 85 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	21-33 inches

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

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Sunny in the morning then becoming partly cloudy	Partly cloudy becoming mostly cloudy	Partly cloudy
Temperatures:	35-41 deg. F.	8-15 deg. F.	27-33 deg. F.
Wind direction:	West shifting to the northwest in the afternoon	North	Southwest shifting to the south in the afternoon
Wind speed:	50-60 mph with gusts to 85 mph decreasing to 25-30 mph with gusts to 40 mph in the afternoon	15-20 mph with gusts to 35 mph becoming light overnight	10-15 mph with gusts to 25 mph increasing to 15-25 mph with gusts to 35 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Sunny in the morning then becoming partly cloudy	Partly cloudy becoming mostly cloudy	Partly cloudy
Temperatures:	32-38 deg. F.	6-13 deg. F.	21-27 deg. F.
Wind direction:	West shifting to the northwest in the afternoon	North shifting to the south after midnight	South
Wind speed:	60-70 mph with gusts to 95 mph decreasing to 35-45 mph with gusts to 65 mph in the afternoon	30-40 mph with gusts to 55 mph decreasing to 10-15 mph after midnight	15-20 mph with gusts to 30 mph increasing to 20-30 mph with gusts to 45 mph in the afternoon
Expected snowfall:	O in.	O in.	O in.