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.

Storm totals across the forecast area ranged from 5-7 inches north of Hwy 50 to 9-12 inches south of Hwy 50. In the northern end of the forecast area the snow started around noon yesterday and slowly moved south with snow starting on Carson Pass around 4pm and on Ebbetts Pass by 6 pm.  Most of the accumulation happened overnight. Temperatures have fallen steadily through the storm reaching the low 20s by this morning. As the storm moved south the winds quickly shifted to the Northeast and increased. They have averaged 35-45 mph with gusts to 77 mph out of the Northeast since 5pm yesterday in the northern end of the forecast area. The shift occurred a little later south of Hwy 50. The leftover snow showers should taper off this morning as the storm continues to move south and east. In its wake strong NE winds and cold temperatures should remain through tomorrow.

Yesterday, observations on NW-N-NE aspects above 8700 ft. in the Mt. Rose area continued to show that the Oct. 19th facet layer sitting on top of the fall ice layer remains a fragile combination. Human-triggerred shooting cracks, whumpfing, and snowpack collapse all occurred in this area. On Mt. Judah, where this combination does not exist, layer bonding tests indicate a stronger albeit much shallower snowpack. Unfortunately, the slopes with the most snow (the best places for recreation) are the same slopes where the weakest snowpack exists.

Today the combination of the weak layer (the facets) and a slippery bed surface (the ice layer) will remain the primary avalanche concern. In areas where a slab sits on top of these layers human-triggerrable avalanche activity will still be possible. However, these areas should be smaller and more isolated today due to the strong NE winds that have scoured the E-NE-N aspects for the last 12 hours. These scouring winds should limit avalanche activity to the slopes that have either some protection on from NE winds or have a hard slab sitting above the facet layer on the N-NE aspects. Cross-loading due to these winds could deposit new slabs in unusual places on NW aspects. Where these new wind slabs form on top of the facet/ice layer combination human-triggerrable avalanches will remain possible today. Digging quick test pits, hand pits, or probing with a ski pole often during the day will be the best way to determine if this layer exists on any particular slope. Use clues like drifts, cornices, ripples, and other wind created features to help determine which slopes have been wind loaded.

Use extra cation in the backcountry today.  A persistent weak layer with variable strength and distribution provides a complex avalanche hazard. Along with the avalanche hazard the early season snowpack just barely covers the myriad of rocks, dirt, stumps, shrubbery, and other knee shattering obstacles.

The bottom line:

Areas of MODERATE avalanche danger exist above 8,700ft. on NW-N-NE aspects 32 degrees and steeper both above and below treeline. For all other areas, avalanche danger is LOW.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	20 deg. F.
Max. temperature in the last 24 hours:	35 deg. F.
Average wind direction during the last 24 hours:	SW until 4-5pm yesterday then the wind shifted to the NE
Average wind speed during the last 24 hours:	45 mph
Maximum wind gust in the last 24 hours:	77 mph
New snowfall in the last 24 hours:	North of Hwy 50: 5-7 inches - South of Hwy 50 9-12 inches
Total snow depth:	9-25 inches

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

For 7000-8000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Mostly cloudy with isolated snow showers this morning. Partly cloudy this afternoon	Mostly clear	Sunny
Temperatures:	26-31 deg. F.	17-22 deg. F.	34-39 deg. F.
Wind direction:	Northeast	Northeast	East
Wind speed:	15-30 mph with gusts to 50 mph	15-20 mph increasing to 20-30 mph with gusts to 45 mph after midnight	10-15 mph with gusts to 35 mph
Expected snowfall:	1-3 in.	O in.	O in.
For 8000-9000 ft:
	Saturday:	Saturday Night:	Sunday:
Weather:	Mostly cloudy with isolated snow showers this morning. Partly cloudy this afternoon	Mostly clear	Sunny
Temperatures:	21-28 deg. F.	20-25 deg. F.	34-39 deg. F.
Wind direction:	Northeast	Northeast	East
Wind speed:	30-45 mph with gusts to 80 mph	25-40 mph with gusts to 70 mph	30-45 mph with gusts to 70 mph decreasing to 20-30 mph with gusts to 55 mph in the afternoon
Expected snowfall:	1-3 in.	O in.	O in.