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 weak weather system passing to the north of the forecast area is expected to bring significant cloud cover in a narrow band along the Sierra Crest with a slight chance of thunderstorms this afternoon. Air temperatures are forecast to be 4 to 8 degrees cooler than yesterday with significant cloud cover limiting incoming solar radiation. To the east of the Sierra Crest, more sunshine is expected in the Carson Range. Ridgetop winds were light and variable for the past 24 hours and are expected to remain light and variable through Wednesday.

Observations:

Observations made yesterday on Tamarack Peak and on Mt. Houghton (Mount Rose area) indicated significant melt freeze conditions on E-S-W aspects. Wet surface snow was noted up to 10,200' on SE aspects by 10:15 am (pit profile). By 1 pm, up to 4 inches of wet snow existed below 9,800' on these aspects. During the afternoon hours, evidence of a skier triggered wet loose snow avalanche was observed in the Third Creek Drainage (Mount Rose area) on a steep SE aspect above treeline. This avalanche was not large enough to bury a person. Observations made yesterday on Donner Peak (Donner Summit area) noted 3 to 4 inches of wet surface snow on S aspects at 7,900'. No significant signs of instability were observed in this area (more info).

High and mid level cloud cover began to thicken over the forecast area around midnight. Remote sensors report that in nearly all locations air temperatures remained just above freezing at all elevations. Some degree of radiational cooling occurred overnight, mainly before cloud cover began to increase. This is expected to have a allowed for only a weak surface refreeze in many areas. Remote sensors indicated that air temperatures dropped several degrees below freezing in the Carson Pass area. A better refreeze is expected to have occurred in this region.

Avalanche Concerns:

Avalanche concerns for today continue to focus on areas of wet snow instability. With only a weak refreeze of the snow surface in many areas, some amount of wet snow instability may exist early this morning. Wet slab avalanches are notoriously hard to predict. While a bit early in the season, this scenario of overnight cloud cover limiting refreeze fits the pattern that sometimes precedes wet slab avalanche activity. While cooler air temperatures are expected to limit snow surface melting compared to what occurred over the past two days, areas of wet snow instability will occur again today. Areas at the far southern portion of the forecast area (Bear Valley and Ebbetts Pass) and far eastern portion (Carson Range) are expected to receive more sun than the rest of the forecast area today. More wet surface snow is expected to form in these areas today than in rest of the forecast area.

The bottom line:

Avalanche danger is LOW with pockets of MODERATE danger below 10,000' on SE-S-SW aspects 35 degrees and steeper. 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:	28 to 37 deg. F.
Max. temperature in the last 24 hours:	46 to 49 deg. F.
Average wind direction during the last 24 hours:	Variable
Average wind speed during the last 24 hours:	4 mph
Maximum wind gust in the last 24 hours:	16 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	67 to 105 inches

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

For 7000-8000 ft:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:	Mostly cloudy skies with a slight chance of thunderstorms along the Sierra Crest in the afternoon.	Mostly cloudy skies with isolated rain/snow showers in the evening. Partly cloudy skies after midnight.	Partly cloudy skies in the morning becoming sunny.
Temperatures:	39 to 46 deg. F.	28 to 34 deg. F.	50 to 56 deg. F.
Wind direction:	Variable	Variable	Variable
Wind speed:	Light winds	Light winds	Light winds
Expected snowfall:	O in.	0 to trace in.	O in.
For 8000-9000 ft:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:	Mostly cloudy skies with a slight chance of thunderstorms along the Sierra Crest in the afternoon.	Mostly cloudy skies with isolated snow showers in the evening. Partly cloudy skies after midnight.	Partly cloudy skies in the morning becoming sunny.
Temperatures:	38 to 44 deg. F.	27 to 33 deg. F.	44 to 52 deg. F.
Wind direction:	Variable	Variable	Variable
Wind speed:	Light winds	Light winds	Light winds
Expected snowfall:	O in.	0 to trace in.	O in.