Good morning, this is Sue Burak with the Inyo National Forest Eastern
   Sierra Avalanche Center. Today is Monday, December 15 and winter has
   finally arrived.

   MOUNTAIN WEATHER

   Bands of heavy snowfall with continue for the rest of today with up to
   2 feet of new snow expected above 8K by tomorrow morning. Heavy
   snowfall is occurring this morning in the Lake Tahoe Basin and this
   band of precipitation is moving south towards Mono County. Strong
   ridgetop winds on Mammoth Mountain and Mt. Warren will continue through
   Tuesday morning. The mid elevations will see average hourly windspeeds
   in the 15-20 mph range with gusts up to 45 mph. Very cold temperatures
   will continue through the rest of the week with 8,000 to 9,000 ft
   elevations struggling to reach the 20 degree mark during the day.

   The Reno National Weather Service forecasters told me this morning the
   next chance of precipitation for our area will be Thursday evening into
   Friday morning. The weekend storm will probably miss Mono County.

   SNOWPACK AND AVALANCHE DISCUSSION
   Wow! It sure is nice to see the NWS homepage colored with winter storm
   warnings along the Sierra Crest. Until this storm arrived, snow depths
   on upper elevation, shaded slopes generally ranged from 8"- 14", with
   the greatest depths existing in the volcanic bowls on the Mammoth Crest
   and San Joaquin Ridge. Black Mountain in the Virgina Lakes region had
   been skied also. Where a previous snowpack exists, I suspect it
   consists primarily of facets and a few crust layers. In other words,
   this storm snow is falling on weak, sugary snowpack, some icy surfaces
   and of course, bare ground.

   If were lucky, by Wednesday morning, there will enough new snow to
   start providing some reasonable backcountry recreation from Bloody
   Mountain north. The lower slopes of the Sherwins will be problematic
   and expect some aspen thrashing. However, it will take another couple
   of feet of snow to open up skiing in talus prone slopes. It will take
   another good storm to open up skiing in the Rock Creek and Bishop Creek
   areas.

   With low density snow falling, the stress being added to the existing
   snowpack is being applied slowly. In wind prone areas, unstable wind
   slabs are developing. As a slab builds atop the old snow from wind
   transport, stay alert to surefire signs of unstable conditions like
   recent avalanches, cracking or collapsing of the snowpack, and easy
   shears of the new snow on the old snow surface.

   BOTTOM LINE

   I have no field data to support making an avalanche forecast at this
   time. Expect a forecast by mid week after I get field data from
   snowpits and field observations.