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.

First storm system tapering off this morning with continued snow showers expected today along the Sierra Crest. Snowfall totals this morning are running 4 to 7 inches above 7,000'. Rising air temperatures overnight brought snow level up to 6,500'. Snow level is falling this morning behind cold front passage. Strong ridgetop winds gusting to 100 mph overnight have decreased to moderate in speed this morning. Winds are expected to remain moderate to strong in speed out of the southwest today. Snow showers today and another storm system passing through the area tonight are expected to bring an additional 5 to 8 inches of new snow in the next 24 hours.

Observations:

Observations made yesterday morning on Tamarack Peak (Mount Rose area) above treeline at 9,280' on a N aspect 42 degree slope indicated stable conditions with a shallow wind slab at the surface (pit profile). Ski cuts on adjacent slopes yielded no evidence of instability. Winds and snowfall amounts from mid day yesterday onward exceeded forecast expectations. A small skier triggered avalanche occurred on a nearby slope around 1 pm after additional wind and snowfall had affected the area. The avalanche occurred above treeline on a NE aspect 40 degree slope and measured 30 feet wide with an 8 inch crown (photo, more info).

Avalanche Concern #1:

Rising air temperatures overnight during a period of intense snowfall are expected to have placed high density new snow on top of lower density new snow. This upside down snowpack is expected to be unstable today with slabs in wind loaded areas 1 to 2+ feet deep.This will be most prevalent on NW-N-NE-E aspects in near and above treeline terrain.  A shallower form of this same instability is expected below treeline in steep wind affected areas.

Avalanche Concern #2:

Lingering instability from yesterday's wind slabs may allow for deep slab instability to occur. Look for an additional weak layer from yesterday's wind slad up to 1 foot below the lower density new snow that exists at the bottom of the new snow that fell overnight. Failure on this layer will cause larger more destructive avalanches to occur.

The bottom line:

Near and above treeline, avalanche danger is MODERATE with pockets of CONSIDERABLE danger on NW-N-NE-E aspects 35 degrees and steeper. Below treeline, pockets of MODERATE danger exist in open wind affected areas 35 degrees and steeper.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	24 to 28 deg. F.
Max. temperature in the last 24 hours:	26 to 29 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	55 mph
Maximum wind gust in the last 24 hours:	100 mph
New snowfall in the last 24 hours:	4 to 7 inches
Total snow depth:	73 to 112 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Cloudy skies with snow tapering to snow showers by mid morning.	Cloudy skies with numerous snow showers in the evening. Snow after midnight.	Cloudy skies with snow in the morning. Snow showers in the afternoon.
Temperatures:	29 to 34 deg. F.	19 to 24 deg. F.	26 to 31 deg. F.
Wind direction:	SW	S	S
Wind speed:	15 to 30 mph with gusts to 50 mph. Winds decreasing to 10 to 20 mph with gusts to 40 mph in the afternoon.	10 to 20 mph with gusts to 40 mph.	10 to 20 mph with gusts to 35 mph.
Expected snowfall:	2 to 4 in.	2 to 3 in.	2 to 5 in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Cloudy skies with snow tapering to snow showers by mid morning.	Cloudy skies with numerous snow showers in the evening. Snow after midnight.	Cloudy skies with snow in the morning. Snow showers in the afternoon.
Temperatures:	23 to 30 deg. F.	16 to 21 deg. F.	21 to 27 deg. F.
Wind direction:	SW	S	S
Wind speed:	30 to 45 mph with gusts to 85 mph. Winds decreasing to 20 to 35 mph with gusts to 65 mph.	20 to 35 mph with gusts to 55 mph.	15 to 25 with gusts to 55 mph. Gusts decreasing to 40 mph in the afternoon.
Expected snowfall:	2 to 4 in.	2 to 3 in.	3 to 5 in.