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.

A fast moving weather system passed through the forecast area early this morning. New snow amounts of 2 to 7 inches at 5% density were quickly deposited, with the greatest accumulations along the Sierra Crest north of Hwy 50. Snowfall will taper off today from north to south with up to 2 inches of additional accumulation, mainly south of Hwy 50. Air temperatures above 7,000' are in the upper single digits to teens this morning across most of the forecast area. Maximum daytime air temperatures above 8,000' are forecast to remain in the teens today. Ridgetop winds shifted from west to northeast early this morning and remain moderate to strong in speed. Moderate to strong north to northeast winds will continue into tomorrow. Decreasing cloud cover and daytime highs reaching into the 30s at the upper elevations are forecast for tomorrow.

Recent Observations:

Observations made yesterday on Silver Peak (Pole Creek area) matched well with other recent observations from around the forecast area showing a lack of significant slab formation in the new snow from Monday. Areas of wind affected snow were highly localized and confined directly to the ridgetops. Any slabs that existed along the ridgetops were less than 4 inches thick and extended only a few feet down slope. Snowpit data collected on a N aspect at treeline at 8,030' continued to show that the crusts and near surface faceted snow that exist directly below the recent new snow remained stable after the addition of the light new snow load on Monday (pit profile, photo, more info).

Today's Avalanche Concerns: Wind Slabs

With a stable snowpack in place prior to the addition of snow snow early this morning, avalanche concerns for today will focus on surface wind slabs formed by redistribution of new snow by moderate to strong N to NE winds. Significant amounts of blowing snow are expected today in near and above treeline areas. In locations that only received a couple of inches of new snow last night, this will be a minor issue with no significant instability created due the minimal amounts of snow to work with. In areas that received the higher end of snow totals this morning, redistribution of snow will easily create slabs around 1 foot thick in heavily wind loaded areas. With shifting winds this morning, pockets of wind slabs will exist on all aspects, especially in complex terrain with many lee areas across a single slope. More simple terrain will have more predictable N-NE-E aspect wind scouring and S-SW-W aspect wind loading. In below treeline areas less scouring will occur, but wind effect on the snow surface may serve to increase the slab properties of the new snow in open wind affected areas, mainly on NW-N-NE-E aspects.

The bottom line:

Near and above treeline, avalanche danger is LOW with pockets of MODERATE danger in wind loaded areas on all aspects on slopes 35 degrees and steeper. Below treeline, avalanche danger is LOW with isolated pockets of MODERATE danger in wind affected areas on NW-N-NE-E aspects on slopes 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:	9 to 15 deg. F.
Max. temperature in the last 24 hours:	27 to 36 deg. F.
Average wind direction during the last 24 hours:	West shifting to northeast
Average wind speed during the last 24 hours:	31 mph
Maximum wind gust in the last 24 hours:	74 mph
New snowfall in the last 24 hours:	2 to 7 inches
Total snow depth:	29 to 37 inches

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

For 7000-8000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:	Mostly cloudy skies with snow tapering off from north to south this morning. Partly cloudy skies north of Hwy 50 this afternoon.	Partly cloudy skies.	Partly cloudy skies.
Temperatures:	23 to 28 deg. F.	13 to 19 deg. F.	33 to 38 deg. F.
Wind direction:	NW shifting to N	NE	E
Wind speed:	15 to 30 mph with gusts to 45 mph.	15 to 25 mph with gusts to 40 mph.	15 to 25 mph with gusts to 40 mph. Winds decreasing to 10 to 20 mph.
Expected snowfall:	Up to 2 in.	O in.	O in.
For 8000-9000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:	Mostly cloudy skies with snow tapering off from north to south this morning. Partly cloudy skies north of Hwy 50 this afternoon.	Partly cloudy skies. Isolated snow showers in the evening south of Hwy 50.	Mostly cloudy skies, becoming partly cloudy.
Temperatures:	13 to 18 deg. F.	11 to 16 deg. F.	30 to 35 deg. F.
Wind direction:	NW shifting to N	NE	E
Wind speed:	40 to 45 mph with gusts to 70 mph. Shifting and decreasing to 30 to 35 mph with gusts to 55 mph by late morning.	35 to 45 mph with gusts to 65 mph.	25 to 35 mph with gusts to 55 mph. Winds decreasing to 15 to 25 mph.
Expected snowfall:	Up to 2 in.	O in.	O in.