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.

The forecast calls for another warm, sunny day over the forecast area. Some clouds should start to develop later this afternoon as a low pressure system from the Gulf of Alaska begins migrating towards the Sierra. The southwest winds should begin to increase ahead of this system. Temperatures should also drop starting tonight due to the approaching system. The NWS has issued a winter storm watch for the area over the weekend.

Temperatures have remained above freezing since around 8 am on the 18th. These warm temperatures combined with some overnight cloud cover prevented a strong refreeze overnight on the 18th. Yesterday, the snow surface softened much more quickly and more widespread melting occurred as a result of the weak refreeze, the March sun, and the warm temperatures. On Jake's Peak 2-3 inches of soft, wet snow already existed on the surface on sun-exposed E-SE-S aspects by 10am yesterday. By 11am 5-7 inches of wet, soft snow had formed on these aspects. After 11am some human-triggered pinwheels and roller-balls occurred on these slopes. Similar melt/freeze conditions existed on the SW-W aspects. The snow on these aspects softened slightly after the snow on the E-SE-S aspects. The sometimes supportable, sometimes breakable rain crust  persisted on most NW-N-NE aspects up to 8500'. Above 8500' firm wind-affected snow remained widespread on these aspects. Very small, isolated pockets of soft snow existed on the N-NE aspects that have remained protected from the wind and sun and above the rain line.

Today, the main avalanche concern will be wet-snow instabilities. Last night's clear skies and slightly cooler temperatures should have allowed the snowpack to undergo a stronger refreeze than it did yesterday. However, the March sun combined with even warmer daytime temperatures should quickly melt snow and prolong the melting phase of the melt/freeze cycle today. The water produced by melting snow will melt the bonds holding the snowpack together and weaken the snowpack. The snowpack could weaken to the point that a person moving across the snow could overload the snowpack and cause it to fail today. Wet-slab avalanches as well as other wet snow instabilities like pinwheels, roller-balls, and wet point-release avalanches will all remain possible today. They will be most prevalent on the E-SE-S-SW-W aspects. More widespread clouds this afternoon could help limit the melting phase of the melt/freeze cycle. These wet-snow instabilities will persist until the snowpack refreezes.

The bottom line:

This morning the avalanche danger is LOW for all aspects and elevations. On E-SE-S-SW-W aspects, the avalanche danger will quickly rise to MODERATE on slopes steeper than 35 degrees for all elevations due to daytime warming.

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	34 deg. F.
Max. temperature in the last 24 hours:	48 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:	35 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	142 inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Sunny in the morning, becoming partly cloudy this afternoon	Mostly cloudy with a slight chance of showers	Cloudy with a chance of snow showers
Temperatures:	50-60 deg. F.	28-35 deg. F.	36-44 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	5-15 mph	10-20 mph with gusts to 40 mph	20-35 mph with gusts to 60 mph
Expected snowfall:	O in.	O in.	up to 1 in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:	Sunny in the morning, becoming partly cloudy	Mostly cloudy with a slight chance of showers	Cloudy with a chance of snow showers
Temperatures:	40-50 deg. F.	25-35 deg. F.	31-41 deg. F.
Wind direction:	Southwest	Southwest	Southwest
Wind speed:	10-15 mph with gusts to 25 mph increasing to 15-25 mph with gusts to 40 mph this afternoon	15-25 mph with gusts to 35 mph increasing to 25-35 mph with gusts to 60 mph after midnight	25-35 mph increasing to 40-50 mph with gusts between 70-90 mph in the afternoon
Expected snowfall:	O in.	O in.	up to 1 in.