Good morning, this is Sue Burak with the Eastern Sierra Avalanche
   Center with an advisory for Monday, February 4, 2008. Mammoth
   Mountaineering Supply is the proud sponsor of todays advisory.

   MOUNTAIN WEATHER
   Snow showers will continue today with light upslope flow. June
   Mountain and Lee Vining could pick up more snow due to the Mono Lake
   effect. Partly cloudy skies today will gradually clear and gusty north
   winds will keep snow blowing around and wind chills below zero.

   Todays highs will be 10 degrees colder than the last weeks highs with
   a very cold 10F expected at the 8,000 to 9,000 ft elevations. There
   wont be any difference between todays high and the night time low.
   Tuesday will be about 15F warmer and the rest of the week will
   gradually warm into the upper 30s. Nights will be cold with
   temperatures in the single digits.

   The higher elevations will be partly cloudy today with moderate north
   winds gusting to 40-50 mph. Highs will be in the single digits today
   and gradually warm into the low 20s by Wednesday.

   No snowfall is expected through Sunday. A trough of low pressure will
   slide northeast of the forecast area on Wednesday with ridging
   building behind. This will leave the area under dry northwesterly flow
   through the end of the week. Sunny skies will be a welcome sight after
   the last two weeks of snow and wind!!

   SNOWPACK AND AVALANCHE DISCUSSION
   South of Mammoth in the Rock Creek and Bishop Creek area, compression
   and stuffblock tests showed a weak layer about 4 inches down in 8
   inches of new snow. Most of the snowpack in these southern areas
   consists of mixed forms and small facets with a well defined
   faceted/depth hoar layer at the base of the snowpack. A rain crust
   about 17 inches down in a three foot deep snowpit up the South Fork of
   Bishop Creek had almost an inch of faceted snow under the crust.

   Up Rock Creek Canyon on Saturday it was easy to trigger small 6-8 soft
   slabs on test slopes on wind loaded northeast aspects. The gullies
   that cross the Rock Creek Road above East Fork were heavily cross
   loaded on Saturday and received more wind loading Saturday night and
   yesterday morning. Please respect the Closed Road sign at East Fork
   and use the alternate route to Rock Creek Lodge. This route is also
   known as the Outhouse Trail.

   New snow accumulation is variable in all wind affected areas with
   light dry snow in glades and slopes least affected by the wind. In
   some places, last weeks surfaces are exposed in many places especially
   in convex terrain exposed to the wind. This snow has a sandblasted,
   scoured, scalloped, roughed-up look.

   For today, expect the unexpected- deep snow pillows that formed well
   downslope from ridgelines and normal starting zones, soft slabs
   sitting on top of hard slabs and hard slabs in alpine terrain. Wind
   and snow over the past week have added up to quite the stack of slabs
   on north through east to south aspects and cross drifted around
   terrain features on other slopes. There are softer slabs sitting on
   top of harder slabs. The hard slabs can be insidious, appearing strong
   until you reach the bottom edge where the slab thins. If triggered
   from the lower margin, the entire slab could rip out above you.

   Be suspicious of any steep slope with recent deposits of wind drifted
   snow. Watch out for cross loading in gullies and chutes at all
   elevations. Wind slabs can form in extremely localized areas. Often
   only a few inches separate safe snow from dangerous snow.

   BOTTOM LINE
   For today, the avalanche danger rating is CONSIDERABLE in wind loaded
   terrain greater than 35 degrees. The avalanche danger rating is
   MODERATE on slopes less than 35 degrees and in areas that did not
   receive wind deposited snow.

   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.