Good Morning! This is Eastern Sierra avalanche advisory for December 31st. 
Have A happy and safe New Year!

Weather:

For the Mammoth area:

Today. Snow. Snow accumulation 10 to 20 inches. Highs 23 to 33. Southwest 
winds 10 to 15 mph with gusts up to 60 mph over ridges.

Tonight. Partly cloudy. Snow likely. Snow accumulation 2 to 5 inches. Lows 9 
to 19. Southwest winds 10 to 15 mph with gusts up to 35 mph. Gusts to 65 mph 
over ridges.

New years day. Mostly cloudy and brisk. Snow. Snow accumulation 2 to 5 
inches. Highs 26 to 36. Southwest winds 15 to 25 mph with gusts up to 100 
mph over ridges.

Saturday night. Snow. Lows 11 to 21. Southwest winds 15 to 20 mph with gusts 
up to 35 mph. Gusts to 100 mph over ridges.

For the Bishop area:

Today. Rain and snow in the morning then scattered showers in the afternoon. 
Snow will be heavy at times in the sierra before 10 am. Breezy with areas of 
blowing and drifting snow. Additional snow accumulation of 4 to 8 inches 
above 5000 feet. Snow level falling to 4000 feet in the afternoon. Highs in 
the lower 40s. Southeast wind 15 to 25 mph in the morning shifting to the 
southwest 10 to 15 mph in the afternoon. Chance of rain and snow 80 percent.

Tonight. Partly cloudy with isolated showers. Lows in the lower 20s. 
Northwest wind around 10 mph. Chance of rain and snow 20 percent. Snow level 
3500 to 4000 feet.

New years day. Partly cloudy with a slight chance of showers in the morning 
then mostly cloudy with a chance of showers in the afternoon. Highs in the 
mid 40s. South wind around 10 mph in the morning shifting to the southeast 
10 to 15 mph in the afternoon. Chance of rain and snow 30 percent. Snow 
level rising to 4500 feet.

Saturday night. Mostly cloudy with a chance of showers. Snow level 3500 to 
4000 feet. Lows in the lower 20s. South wind 10 to 15 mph in the evening 
decreasing to around 10 mph after midnight. Chance of rain and snow 30 
percent.

Snow pack: With an already weak snow pack and additional loading from the 
strong winds and snow. Our current snow pack is under tremendous stress. The 
new snow that fell early this week in this event had been already been 
reacting to the stress that was put upon it.

Storm totals so far from this week

Tioga Pass Area: 50 inches ( 127cm.)
Mammoth Area : last 24 hours 120 inches ( 304 cm.)
South lake/Bishop Creek Areas : 62 inches ( 157 cm.)

Advisory:

Alpine: HIGH
Tree line: HIGH
Below tree line: CONSIDERABLE

The Eastern Sierra is a big region these advisories may not apply to the 
area you plan to visit. Please use caution.