Good Morning, this is Sue Burak from the Inyo National Forest Eastern
   Sierra Avalanche Center with an avalanche advisory for Thursday
   February 19, 2009.

   The avalanche danger rating is only a starting point. YOU CONTROL YOUR
   OWN RISK by choosing where and when you travel.

   MOUNTAIN WEATHER

   Sunny and clear skies will continue until the weekend. There will be an
   absence of strong winds in the mountains the next few days.

   Expect highs in the 40s at the 8,000 to 9,000 ft elevations through the
   end of the week. Higher elevations will be in the low 30s but will feel
   warmer because the suns energy is increasing as we head towards spring.
   Nights will continue to be cold in the mountains and lows will be in
   the mid teens.

   SNOWPACK AND AVALANCHE DISCUSSION

   The snowpack conditions are variable across the Bishop Creek to June
   Lake area. Around Mammoth and June, the storms dropped around 30 to 40
   of new snow since Monday. Avalanche activity varied depending on
   location. South of Mammoth, loose snow avalanches run up to 1,000 feet
   on steep east facing slopes. These avalanches tended to start around
   rocky outcrops. Slab avalanche debris from last weeks storms was
   visible near the bottom of many bowl shaped starting zones.

   Many loose snow avalanches occurred on the Sherwins and Lakes Basin and
   slab avalanche debris was observed near wind loaded starting zone.
   There were several very recent wind slab avalanches that pulled out in
   short steep wind loaded and crossloaded terrain features in the Lakes
   Basin.

   In the June Lake area, there is a very reactive rain/snow layer not far
   above the ground. Below the June Mountain Mid Chalet this layer is
   about 8 inches above the ground in a 3 ft snowpack. There is some
   potential for large human triggered slides on this layer outside of the
   ski area. A large natural slab avalanche released in the Negatives
   sometime Wednesday morning, many hours after snowfall ended. The
   Negatives have been windloaded from west winds for days. The crown of
   the avalanche propagated across the bowl with the crown and flanks
   estimated in the 4-5 foot range.

   Despite several days of ski cutting and hand charging on the lower part
   of June Mountain below the Mid Chalet, a snowboarder triggered a slide
   Wednesday. The sliding layer was the hard rain/snow layer of late
   January and the slide ran on well developed faceted snow sitting on top
   of the rain/snow layer. After this human triggered slide occurred in
   bounds in an area previously controlled with hand charges and ski
   cutting, you could probably trigger a slide on a similar slope,
   elevation and aspect outside of the ski area. Look at the slope you
   want to ski today- if the slope has not avalanched, remember how much
   wind loaded snow is on the slope. Think of a good reason other than the
   snow looks good to give your party or partner why you should ski the
   slope.

   BOTTOM LINE

   For the June Lake backcountry. The avalanche danger rating for north
   and east facing slopes in alpine areas is CONSIDERABLE. The avalanche
   danger rating for north and east facing slopes in steep trees below
   9,000 ft is CONSIDERABLE. Natural avalanches are possible and human
   triggered avalanches are probable. Evaluate the snow and terrain
   carefully and use good travel habits to minimize risk.

   In the Mammoth Lakes Basin and Sherwins, stability in the storm snow
   will rise with time and increasing solar radiation over the next few
   days. Watch out for sensitive wind slabs in all wind loaded alpine
   areas, particularly just off ridgelines and on convex rollovers on
   slopes steeper than 35 degrees in northeast and east facing terrain.
   The avalanche danger rating for the Mammoth area is CONSIDERABLE in
   isolated steep wind loaded terrain above treeline. In mid elevations
   trees and glades, the avalanche danger rating is MODERATE which means
   there are locally unsafe conditions. Use good travel habits to minimize
   the risk.

   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.