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.

Cold air that has been in place over the forecast area for the past two days is moving out of the area. Air temperature inversion will keep air temperatures at the lower elevations on the cool side while significant warming occurs at the mid and upper elevations today, tonight, and tomorrow. Ridgetop winds increased significantly late yesterday afternoon, becoming strong in speed. Winds are forecast to remain out of the E to NE and remain moderate to strong through tomorrow.

Recent Observations:

Observations made yesterday on Silver Peak (Pole Creek area) and on Castle Peak (Donner Summit area) revealed differences in upper snowpack stability as affected by winds in the late afternoon versus the morning and mid day hours. During the morning and mid day hours on Silver Peak, NE winds were light with little to no wind transport of snow on the ground. Good to very good snowpack stability was observed in the area (more info). After 2 pm, NE winds increased significantly and began to move snow. Blowing snow became visible along the Sierra Crest in above treeline areas. On Castle Peak, very small but unstable fresh wind slabs were observed in lee areas by 3:15 pm. These wind slabs became reactive to the weight of a skier with shooting cracks in slabs up to 1 foot deep. At that time these wind slabs did not extend more than a few feet down slope from ridgelines (photos, pit profile, more info).

Avalanche Problem #1: Wind Slabs

A fresh round of wind slab formation occurred late yesterday afternoon through last night. Small slabs observed late yesterday will have increased in size and depth during the overnight hours. Human triggered wind slab avalanches are possible today in recently wind loaded areas in near and above treeline terrain. SE-S-SW-W-NW aspects will hold the most well developed wind slabs and the greatest level of danger. Employ travel practices designed to minimize exposure and risk.

The bottom line:

Near and above treeline, avalanche danger is MODERATE on SE-S-SW-W-NW aspects on slopes 35 degrees and steeper. New wind slabs formed late yesterday afternoon and last night. For all other areas, 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:	1 to 7 deg. F.
Max. temperature in the last 24 hours:	12 to 22 deg. F.
Average wind direction during the last 24 hours:	Northeast
Average wind speed during the last 24 hours:	23 mph
Maximum wind gust in the last 24 hours:	62 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	64 to 89 inches

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

For 7000-8000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:	Sunny skies.	Clear skies.	Sunny skies.
Temperatures:	22 to 26 deg. F.	22 to 32 deg. F.	35 to 40 deg. F.
Wind direction:	E	E	E
Wind speed:	25 to 35 mph with gusts to 45 mph.	20 to 30 mph with gusts to 40 mph.	20 to 30 mph with gusts to 40 mph.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:	Sunny skies.	Clear skies.	Sunny skies.
Temperatures:	21 to 25 deg. F.	22 to 32 deg. F.	37 to 40 deg. F.
Wind direction:	E	E	E
Wind speed:	35 to 45 mph with gusts to 65 mph.	30 to 40 mph with gusts to 65 mph. Gusts decreasing to 55 mph after midnight.	25 to 35 mph with gusts to 55 mph. Gusts decreasing to 45 mph in the afternoon.
Expected snowfall:	O in.	O in.	O in.