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.

 Another warm and sunny day with above average air temperatures and light to moderate southwest winds is forecast for today. An air temperature inversion has most locations above 6,500' in the mid 30s to mid 40s this morning. This will give the upper elevations a good head start on warming today with daytime highs in the 40s and 50s expected for nearly all elevations. Ridgetop winds will increase to moderate in speed tonight in response to a weather system passing to the north of the forecast area tomorrow. An increase in cloud cover and slightly cooler but still above average air temperatures are expected for Thursday. Moderate speed southwest winds are expected to continue for the next couple of days

Observations:

 Recent observations from around the forecast area, including those made yesterday on Tamarack Peak (Mount Rose area) reveal a stabilizing trend in the existing snowpack. The warming and rain event that occurred on December 28-29 added free water to the snowpack. This free water allowed for significant rounding and bonding of faceted snow that had existed for most of the season in the middle and lower portions of the snowpack. As the snowpack has refrozen over the past few days, the entire snowpack has gained strength. This significant structural change and increase in strength has been noted along the Sierra Crest up to at least 9,000'. Most areas above 9,000' have been significantly wind scoured. Isolated snow covered areas above 9,000' that picked up less free water during the melt and rain event are still covered with a rain crust. In some areas there are still loose facets below the crust, but the overall snowpack in these areas tends to be shallow, patchy, and well anchored. Across the forecast area, snow surface conditions in most areas range from breakable to supportable crust anywhere from 1/2 inch to 6 inches thick.

  

Avalanche Concerns:

Avalanche concerns at this time are few. The Dec 28-29 warming event created significant changes in the existing snowpack, especially north of Hwy 80 in what were the most worrisome areas. Now that the persistent weak layer of basal facets has been mostly destroyed, a strong and stable snowpack exists in most snow covered areas. Despite warm daytime air temperatures, wet snow instability is not expected to form on NW-N-NE-E aspects due to weak solar radiation at this time of year. SE-S-SW-W aspects are generally void of snow, negating concerns for wet snow instability on the aspects that receive the highest amounts of solar radiation.

 

 

The bottom line:

LOW avalanche danger exists for all elevations and aspects. Normal caution is advised.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	36 to 43 deg. F.
Max. temperature in the last 24 hours:	44 to 50 deg. F.
Average wind direction during the last 24 hours:	Southwest
Average wind speed during the last 24 hours:	20 mph
Maximum wind gust in the last 24 hours:	37 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	2 to 18 inches

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

For 7000-8000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:	Partly cloudy skies in the morning, then clearing.	Partly cloudy skies.	Mostly cloudy skies.
Temperatures:	48 to 55 deg. F.	32 to 38 deg. F.	43 to 50 deg. F.
Wind direction:	SW	SW	SW
Wind speed:	Around 10 mph.	Up to 10 mph with gusts to 25 mph.	10 to 15 mph with gusts to 25 mph. Gusts increasing to 35 mph in the afternoon.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Wednesday:	Wednesday Night:	Thursday:
Weather:	Partly cloudy skies in the morning, then clearing.	Partly cloudy skies.	Mostly cloudy skies.
Temperatures:	48 to 54 deg. F.	31 to 38 deg. F.	43 to 49 deg. F.
Wind direction:	SW	SW	SW
Wind speed:	10 to 20 mph with gusts to 35 mph.	10 to 15 mph increasing to 15 to 25 mph after midnight. Gusts to 35 mph.	20 to 30 mph with gusts to 50 mph.
Expected snowfall:	O in.	O in.	O in.