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.

Another weather system will pass to the north of the forecast area today. Continued cloud cover and snow showers are expected today with most of the snowfall occurring during the afternoon and evening hours. A total of 2 to 6 inches of new snow is expected in the next 24 hours. A similar weather pattern occurred yesterday, bringing a trace to 2 inches of new snow to the forecast area over the past 24 hours. Remote sensors are reporting air temperatures in the low to mid teens this morning in nearly all locations above 8,500'. Southwest ridgetop winds have remained light to moderate in speed for the past 24 hours and are expected to continue into Monday.

Observations:

Observations made yesterday on Waterhouse Peak (Luther Pass area) revealed continued wind loading and instability in near treeline terrain along the summit ridge. Skier triggered cracking and some areas of slab failure around 8 inches deep were observed on N aspect 32 to 40 degree test slopes at 9,340' (photo). The greatest amount of fracture propagation was observed in areas where a higher density wind slab existed at the snow surface. In wind sheltered areas below treeline, no evidence of instability was observed. This matched well with observations made yesterday on Becker Peak (Echo Summit area) at 7,930' on a N aspect in wind sheltered below treeline terrain. In this area, a number of formal and informal snowpit and field tests indicated the presence of a stable snowpack in this wind sheltered terrain (more info, video).

Avalanche Concerns:

Avalanche concerns for today continue to focus on unstable slabs in recently wind loaded areas in near and above treeline terrain. The greatest areas of instability are expected to occur on N-NE-E aspects. This morning, lingering instability from yesterday's wind loading will be the main concern. As new snowfall occurs this afternoon and evening, additional wind loading will enhance any areas of instability that exist this morning and create additional areas of unstable slabs. With recent observations indicating that the deeper snowpack is continuing to gain strength, instability observed today is expected to remain limited to the upper 1 to 2 feet of the snowpack.

 

The bottom line:

Near and above treeline, pockets of MODERATE avalanche danger remain in wind loaded areas on N-NE-E aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	13 to 15 deg. F.
Max. temperature in the last 24 hours:	22 to 25 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	27 mph
Maximum wind gust in the last 24 hours:	47 mph
New snowfall in the last 24 hours:	trace to 2 inches
Total snow depth:	80 to 112 inches

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

For 7000-8000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:	Mostly cloudy skies with a slight chance of snow in the morning. Snow likely in the afternoon.	Cloudy skies with snow likely in the evening. Scattered snow showers after midnight.	Cloudy skies with snow.
Temperatures:	24 to 31 deg. F.	22 to 29 deg. F.	28 to 35 deg. F.
Wind direction:	SW	SW	SW
Wind speed:	Around 10 mph.	10 to 15 mph with gusts to 25 mph after midnight.	10 to 15 mph with gusts to 30 mph.
Expected snowfall:	Up to 2 in.	2 to 4 in.	2 to 4 in.
For 8000-9000 ft:
	Sunday:	Sunday Night:	Monday:
Weather:	Mostly cloudy skies with a slight chance of snow in the morning. Snow likely in the afternoon.	Cloudy skies with snow likely in the evening. Scattered snow showers after midnight.	Cloudy skies with snow.
Temperatures:	22 to 29 deg. F.	20 to 27 deg. F.	25 to 32 deg. F.
Wind direction:	SW	SW	SW
Wind speed:	10 to 20 mph with gusts to 40 mph.	20 to 30 mph with gusts to 45 mph. Gusts increasing to 55 mph after midnight.	15 to 25 mph with gusts to 55 mph.
Expected snowfall:	Up to 2 in.	2 to 4 in.	2 to 4 in.