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.

This advisory was posted on Friday, January 12, 2007 at 7:00 am

Northeast flow has returned following this small storm. The winds shifted to the north and east along the Sierra Crest yesterday afternoon and will continue from the north and east through the weekend. Only about 1.5 inches of new snow fell on the mountains yesterday and only a trace last night bringing our 24 hr total to almost 2". The cold air mass will stay over the forecast area through Sunday. By the beginning of next week we should see a stable high pressure settle over the area and temperatures will climb back into the normal range.

Above treeline the snow surface is a mix of wind scoured surfaces, glazed crusts, some old hard slabs, and some small, new windslabs. These new windslabs are now sitting mostly on the NW-W aspects because the north and east winds are moving what little snow we got to these aspects from the NE-E aspects. The new windslabs will be small and will not add much additional load to the current snowpack making natural avalanches unlikely. On some of the steeper more windloaded slopes, small, isolated sections of these new windslabs could be tender enough to be triggered by human activity on the slope. The new windslabs would likely fail at their interface with the old snow surface and any slides that are triggered will likely be very small and not run very far. Even though these slides seem insignificant, they could still push you into places you don't want to go. Watch out for terrain traps like cliffs, gullies, and creeks that will amplify the consequences of any size avalanche.

On the SW-S-SE aspects where the melt/freeze crust formed earlier, there is now a dusting of new snow covering these hard, icy crusts. The dusting of new snow is also just barely hiding many of the obstacles that still exist on the slopes. The best snow conditions exist on the northerly tree covered slopes that have been protected from the winds. These slopes now have 2 new inches of cold, low density snow sitting on top of some slightly denser, but still unconsolidated, snow left over from the last storm we had.

Today near and above treeline the avalanche danger is LOW for all non wind affected areas. On the windloaded N-NW-W aspects steeper than 35 degrees small isolated pockets of MODERATE avalanche danger exist.

Below treeline today the avalanche danger remains LOW.

Andy Anderson , Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet):
1 deg. F
Max. temperature at Sierra Crest past 24 hours:
12 deg. F
Average wind direction at Sierra Crest past 24 hours:
East northeast
Average wind speed at Sierra Crest past 24 hours:
30-40 mph
Maximum wind gust at Sierra Crest past 24 hours:
61 mph
New snow fall at 8,200 feet past 24 hours:
1-2 inches
Total snow depth at 8,200 feet:
40 inches
Mountain Weather Forecast For Today:
Partly cloudy with a few isolated snow showers. Clearing by the afternoon.
Temperature forecast for 8,000 to 9,000 feet:
0-5 deg. F
Ridgetop winds forecast for the Sierra Crest:
Northeast winds 30 to 35 mph gusting to 55 mph
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Partly cloudy with a few isolated snow showers especially on the southwest end of the lake. Clearing by the afternoon. Daytime highs 5-13 deg. F. Northeast winds 15 to 25 mph gusting to 35 mph. Overnight, clear with lows 3 below zero to 3 above zero. Northeast winds at 10 to 20 mph. Tomorrow will be sunny. Daytime highs 18 to 24 degrees F. East winds at 10 to 20 mph gusting to 30 mph in the afternoon.

Above 8000 Feet
Partly cloudy with a few isolated snow showers especially on the southwest end of the lake. Clearing by the afternoon. Daytime highs 0-5 deg. F. Northeast winds 30 to 35 mph gusting to 55 mph. Overnight, clear with lows around 2 below zero. Northeast winds at 40 to 50 mph with gusts to 60 mph. Tomorrow will be sunny. Daytime highs 15 to 22 degrees F. Northeast winds at 40 to 50 mph gusting to 60 mph and decreasing to 30-35 mph with 50 mph gusts in the afternoon.

The bottom line:

Andy Anderson - Avalanche Forecaster, Tahoe National Forest

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

0600 temperature:	deg. F.
Max. temperature in the last 24 hours:	deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours:	mph
Maximum wind gust in the last 24 hours:	mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	inches

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

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.