Good morning, this is Sue Burak with the Eastern Sierra Avalanche
   Center with an avalanche advisory posted on Friday February 22, 2008.
   

   MOUNTAIN WEATHER

   Moderate snowfall will continue this morning before turning to showers
   by the afternoon. Another 4-6 inches are expected this morning above
   8,000 feet. Temperatures will be similar to yesterday with highs at the
   8,000-9,000 ft elevations in the mid to upper 20s. Above 10,000 ft,
   another 6-8 inches of new snow is expected by mid day with high
   temperatures in the teens to around 20 F.

   After relatively calm winds yesterday afternoon and evening, southwest
   winds will pick up today. Expect winds in the 15-25 mph range with
   gusts to 40 mph at the 9,000 ft elevations. Higher elevations will see
   gusts up to 60 mph.

   There is a winter storm watch posted for the Saturday/Sunday storm.
   There is an extensive moisture plume stretching back from this system
   to the west-southwest all the way back to the Southwest Pacific. The
   shortwave associated with this storm intensifies remarkably to become
   an intense upper level small-scale low. As it approaches tomorrow,
   southwest flow ahead of the upper level wave will bring some warming to
   the area with snow levels starting high above 7,500 ft. Snow levels
   will drop Saturday night but locations like Lee Vining and Toms Place
   may receive more rain than snow.

   SNOWPACK AND AVALANCHE DISCUSSION

   Snowfall began yesterday afternoon with little wind. Skiing in the
   Mammoth Lakes Basin yesterday afternoon was remarkable for the light
   winds and also the amount of graupel. This morning, over 14 inches of
   new snow has accumulated at the 9,000 ft elevation in the Lakes Basin
   and Mammoth Mountain.

   Over a foot of new snow has fallen from the Sonora Pass area to Mt.
   Whitney with Ellery Lake, Rock Creek and South Lake picking up 14 +
   inches of new snow. Water contents are in the 1 to 1.5 range. Snowfall
   rates last night were intense in the Rock Creek and Bishop Creek area
   with 3 inches an hour falling for a period of 4 hours.

   Winds during the main snowfall part of the storm were relatively calm
   with gusts in the 30-40 mph range. Strong southwest winds are picking
   up this morning so expect wind loading on all northern aspects. Winds
   will continue through today, and wind loading will be occurring all day
   with a plentiful supply of snow to move around.

   There are a couple of potential weak layers in the new snow. First,
   yesterdays new snow was bonding well to old snow surfaces. However, a
   graupel layer was shearing easily within the new snow. Look for this
   layer at about 6- 8 down. Pay attention to slopes that feel slabby or
   punchy- this means dense snow is sitting on top of lighter snow that
   fell before the winds picked up last night.

   BOTTOM LINE
   For today, the avalanche danger rating is CONSIDERABLE on all wind
   loaded slopes steeper than 35 degrees. Wind loading will be found today
   on all north facing slopes. The avalanche danger rating today on non
   wind loaded slopes less than 35 degrees is MODERATE.

   Please note that the avalanche danger rating in this advisory expires
   in 24 hours. This advisory is our best interpretation of snow pack
   conditions and NWS forecasts issued today. Backcountry travelers should
   be aware that elevation and geographic distinctions are approximate and
   that a transition zone exists between upper and lower elevations.

   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 of 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.