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.

High pressure continues to build over the forecast area. Northeast winds increased significantly yesterday evening and last night. Wind speeds reached strong to gale force at times. Wind speeds are forecast to decrease this afternoon and tonight. A slow warming trend is expected over the next few days with below average air temperatures today becoming above average on Wednesday. Remote sensors are reporting air temperatures above 8,000' in the low to upper teens this morning. Maximum daytime air temperatures are forecast to reach into the low 20s to low 30s today for areas above 7,000'.

Recent Observations:

Observations made yesterday on Mt. Tallac (Desolation Wilderness area) revealed a change in conditions from the morning and mid day hours to the evening hours. During the morning and mid day hours, NE winds were insufficient to move snow with stable snowpack conditions observed. In near and above treeline areas, around 2 inches of low density snow was available for wind transport (pit profile, video, more info). Around 5 pm, remote sensors reported a significant increase in ridgetop winds from  20 to 25 mph gusting 30 to 35 mph up to 45 to 55 mph gusting 60 to 92 mph. This increase is expected to have scoured what snow was available for wind transport near and above treeline on N-NE-E aspects and deposited it into lee areas.

Avalanche Problem #1: Wind Slabs

Recent northeast winds are expected to have scoured snow from near and above treeline areas on N-NE-E aspects and deposited it into lee areas on SE-S-SW-W-NW aspects. This is expected to have occurred on both the macro and micro aspect scale on lee slopes.(i.e. cross loaded macro scale N-NE aspects are likely to hold newly formed wind slabs on W-NW aspect micro scale slope features such as the edges of gullies. Know your terrain.) Slab size is expected at less than 1 foot deep and focused close to the terrain feature that creates the lee area for deposition.

The bottom line:

Near and above treeline, pockets of MODERATE avalanche danger exist on SE-S-SW-W-NW aspects on slopes 35 degrees and steeper. Expect to find small wind slabs in a variety of lee areas near ridgelines. For below treeline areas, avalanche danger remains LOW.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	11 to 18 deg. F.
Max. temperature in the last 24 hours:	18 to 26 deg. F.
Average wind direction during the last 24 hours:	Northeast
Average wind speed during the last 24 hours:	40 mph
Maximum wind gust in the last 24 hours:	66 to 92 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	57 to 80 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.	Partly cloudy skies.
Temperatures:	26 to 33 deg. F.	16 to 22 deg. F.	32 to 39 deg. F.
Wind direction:	NE	NE	E
Wind speed:	30 to 40 mph with gusts to 55 mph, decreasing to 20 to 25 mph with gusts to 35 mph in the afternoon.	15 to 20 mph with gusts to 30 mph in the evening, becoming light.	10 to 15 mph in the morning, becoming light.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Monday:	Monday Night:	Tuesday:
Weather:	Sunny skies.	Clear skies.	Partly cloudy skies.
Temperatures:	20 to 27 deg. F.	14 to 21 deg. F.	26 to 33 deg. F.
Wind direction:	NE	NE	NE
Wind speed:	40 to 50 mph with gusts to 65 mph, decreasing to 20 to 30 mph with gusts to 45 mph in the afternoon.	15 to 25 mph with gusts to 35 mph, decreasing to 10 to 15 mph with gusts to 25 mph after midnight.	15 to 20 mph with gusts to 30 mph.
Expected snowfall:	O in.	O in.	O in.