Good morning, this is Sue Burak with the Eastern Sierra Avalanche
   Center with an avalanche advisory posted for Saturday, January 19,
   2008.

   MOUNTAIN WEATHER
   Today is the final day of mild temperatures before temperatures free
   fall 15 to 20 degrees. Today will be mild with 8,000 ft elevation
   temperatures in the low 40s and mid 30s at 9,000 feet. By Sunday,
   daytime highs will be 10 degrees colder and Monday will be another 10
   degrees colder. Lows will be in the 4-8F range.

   Winds will be from the west today, with gusts up to 45 mph. By Sunday,
   west winds will be gusting on the ridgetops up to 50 mph. Snowfall is
   expected by Sunday late afternoon. Snow is likely on Sunday, Monday
   and Tuesday. The Owens Valley could see a few inches of snow Monday
   into Wednesday morning. Owens Valley temperatures will drop also from
   highs in the mid 50s to 40F on Monday.

   The upcoming storm will be directed at the eastern Sierra from Reno to
   Mammoth Lakes. NWS forecasters are calling for significant snowfall
   but they have not given any precipitation amounts yet. For Tuesday,
   NWS expects an additional foot of snow in the Bridgeport area. For
   Tuesday, snowfall will be focused in the Bridgeport to Bishop area
   along the 395 corridor.

   SNOWPACK AND AVALANCHE DISCUSSION
   Stability tests in the Lakes Basin, Valentine Lakes, McGee Mountain
   and Rock Creek are similar- mostly upper end moderate to hard results
   with the compression test. My extended column tests show no fracture
   and no propagation even in shallow snow on high southern aspects.

   Common to all areas is surface hoar and near surface facets. Near
   surface faceting is driven by solar radiation warming the snow below
   the surface while the snow surface cools from longwave radiation and
   other processes. Extreme temperature gradients can form near the snow
   surface, resulting in facets forming within a few hours.

   How well the new snow will bond to the variety of crusts, wind board
   and small facets and surface hoar is as important as the amount of
   precipitation that falls. Wind loading will be another factor to
   consider as snow begins to fall on Sunday afternoon.

   BOTTOM LINE
   The avalanche danger rating today is LOW. Human triggered avalanches
   are unlikely. The snowpack is generally stable. Pay attention if you
   get on a steep slope greater than 35 degrees and the snowpack is
   shallow near trees, rocks where the development of weak snow is
   favored. Fractures can start in these areas and propagate into areas
   of stronger deeper snow, though this is unlikely now.

   This advisory is our best interpretation of snow pack conditions and
   NWS forecasts issued today. This is a regional forecast and
   significant variations may exist within the forecast area. The
   information and danger ratings are intended as a trip planning aid for
   recreational, backcountry users of avalanche terrain; they are not
   meant to be used as the sole factor in determining the avalanche
   danger presented by a specific slope. Avalanches do not happen by
   accident and most human involvement is a matter of choice, not chance.
   Most avalanche accidents are caused by slab avalanches that are
   triggered by the victim or member of the victim's party. Even small
   slides can be dangerous. Always practice route finding skills and
   carry avalanche rescue gear. Remember that avalanche danger ratings
   are only general guidelines. Distinctions between geographic areas,
   elevations, slope aspects and slope angles should be made.