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.

Mostly cloudy skies first thing this morning will quickly give way to cloudy skies and snow by mid day. Snow level is expected to begin around 6,500' today and fall to 3,000' late tonight. Snowfall intensity is expected to increase as the day progresses, with the bulk of forecast snowfall accumulating between 1pm and 10pm tonight. Snowfall rates of 2 inches per hour are expected between 4pm and 8pm this evening. New snow amounts of 7 to 15 inches are expected by midnight tonight. Southwest ridgetop winds are continuing to increase this morning ahead of the approaching storm system. Strong ridgetop winds with gusts to 100 mph are expected by this afternoon. Air temperatures at the 8,000' level are expected to warm to the low to mid 30s this morning before cooling through the afternoon and evening hours.

Observations:

Observations made yesterday on Incline Lake Peak (Mount Rose area) revealed widespread wet snow instability on E-SE aspects involving the recent new snow. Many small natural point release avalanches were observed on these aspects in open sun exposed areas both above and below treeline. A more significant intentionally skier triggered wet loose snow avalanche occurred at 9,750 on a SE aspect 40 degree slope. The avalanche involved the top 4 to 6" of recent new snow and measured 40' wide and ran 500' down slope. The bed surface was a pencil hard sun crust (photos, pit profile, more info). On more northerly aspects between 8,400' and 10,000' where the sun crust was absent, no evidence of instability was observed.

Avalanche concerns:

Avalanche concerns for today focus on new snow, winds, and slabs that are expected to increase in size and become more widespread during the afternoon and evening hours. Strong SW ridgetop winds today will move any snow available for wind transport. Slab formation on NW-N-NE-E-SE aspects is expected to begin this morning with transport of old snow. Increasing wind loading will begin around mid day and continue overnight with the onset of new snowfall. Strong winds and snowfall rates around 2 inches per hour will allow for a rapid increase in avalanche danger during the late afternoon and evening hours. Natural slab avalanche activity will be possible during this time.

Some melting of surface snow will occur this morning due to warming air temperatures, but significant wet snow instability is not expected.

The bottom line:

Near and above treeline, avalanche danger will rise to MODERATE this afternoon and on to CONSIDERABLE this evening on NW-N-NE-E-SE aspects, 35 degrees and steeper. Below treeline, avalanche danger is LOW with areas of MODERATE avalanche danger forming during the afternoon and evening hours on all aspects, 35 degrees and steeper.  Natural slab avalanche activity is expected beginning late this afternoon and continuing overnight. If the top end of forecast snowfall amounts are reached, a short period of HIGH avalanche danger is possible after sunset.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	25 to 27 deg. F.
Max. temperature in the last 24 hours:	31 to 41 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	30 mph
Maximum wind gust in the last 24 hours:	60 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	91 to 123 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Mostly cloudy skies with isolated snow showers in the morning. Cloudy skies with snow in the afternoon.	Cloudy skies with snow in the evening. Snow showers likely after midnight.	Mostly cloudy skies with isolated snow showers before 9am, then partly cloudy skies.
Temperatures:	35 to 40 deg. F.	12 to 17 deg. F.	22 to 30 deg. F.
Wind direction:	SW	SW shifting to W	W shifting to NE by late morning.
Wind speed:	15 to 25 mph with gusts to 55 mph. Winds increasing to 20 to 35 mph with gusts to 70 mph in the afternoon.	20 to 30 mph with gusts to 60 mph. Winds decreasing to 15 to 25 mph with gusts to 40 mph after midnight.	10 to 20 mph
Expected snowfall:	Up to 2 in.	6 to 12 in.	0 to trace in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Mostly cloudy skies with isolated snow showers in the morning. Cloudy skies with snow in the afternoon.	Cloudy skies with snow in the evening. Snow showers likely after midnight.	Mostly cloudy skies with isolated snow showers before 9am, then partly cloudy skies.
Temperatures:	30 to 35 deg. F.	10 to 15 deg. F.	20 to 25 deg. F.
Wind direction:	SW	SW	W shifting to NE by late morning.
Wind speed:	25 to 35 mph with gusts to 70 mph. Winds increasing to 40 to 55 mph with gusts to 100 mph by afternoon.	40 to 55 mph with gusts to 90 mph. Winds decreasing to 30 to 45 mph with gusts to 80 mph after midnight.	15 to 25 mph with gusts to 50 mph. Winds decreasing to 15 to 20 mph with gusts to 30 mph.
Expected snowfall:	2 to 4 in.	6 to 12 in.	trace to 1 in.