Good morning, this is Sue Burak from the Inyo National Forest Eastern
   Sierra Avalanche Center with the avalanche advisory for Tuesday,
   February 10, 2009.

   Tim Villanueva and I will present an avalanche awareness evening at the
   White Mountain Research Station at 6 PM this Wednesday night. This is a
   free event.

   MOUNTAIN WEATHER

   After a cold clear night, expect mostly sunny skies this morning until
   the late afternoon. Today is the first and last day of mostly sunny
   skis and clear, dry weather before unsettled weather returns to the
   eastern Sierra. Below average temperatures, clouds and snow showers
   will continue through the end of the week.

   Elevations above 9,500 ft will continue to see daytime highs in the mid
   to upper teens. High elevation low temperatures will remain cold and in
   the single digits. Mid elevations from 8,000 to 9,000 ft will have
   unsettled weather through the week with below normal temperatures. High
   temperatures will be in the upper 20s and lows will be in the low to
   mid teens. A cold air mass over our area will stick around for the
   week. This means the storms forecasted to affect our area will be cold
   with low snowlines, though little snow accumulation is expected.

   Gusty north and northwest winds will affect the higher terrain from
   Tioga Pass to the Bishop Creek area today. Gusts could reach 45 mph
   over the higher terrain. Winds will shift to the west later tonight and
   will be from the southwest on Wednesday as a weak storm passes north of
   us.

   SNOWPACK AND AVALANCHE DISCUSSION

   Surface winds in the Mammoth area above 9,000 ft died down yesterday
   afternoon, while strong west winds plagued the ridgetops in the Mammoth
   Basin and the Sherwins. Southeast and east facing slopes in the
   mountains in the Tioga Pass and June Mountain area were wind loaded by
   many hours of strong northwest winds.

   Farther south, strong northwest winds moved snow onto high elevation
   southerly terrain in the high mountains west of Bishop. The southern
   Sierra picked up 10 to 12 inches of snow in a short time on Saturday
   night and another 4-6 inches was reported Monday morning.

   Avalanche conditions are dangerous due to strong winds and plenty of
   new snow to move around. One observer reported a slab avalanche
   occurred early Monday afternoon on the Solar Bowl at the northern end
   of the Negatives. The southeast facing slopes had been wind loaded all
   day with snow transported by strong northwest winds. The crown was 2-3
   feet and the slide ran over 1,000 ft.

   The main avalanche story is the wind. The Sierra is known for wind
   loading being the major factor in recent avalanche fatalities. Wind
   speeds have been strong enough to transport snow onto lee slopes below
   exposed ridgetops and in open areas in the trees. Yesterdays wind
   loading mostly occurred on northeast and east facing terrain in the
   Mammoth Lakes Basin. The Tioga Pass and June Mountain areas had strong
   northwest winds that loaded east and southeast terrain. Strong
   northwest winds loaded east and southeastern aspects above 9,500 ft in
   the Bishop Creek area.

   Before jumping onto steep exposed slopes and gullies, take a minute or
   two and figure out where the wind came from and look for signs of wind
   loading such as deep pockets of wind transported snow, scouring and
   cornices. Avoid convex pillows of wind deposited snow and dont ski
   under big cornices.

   Also, remember the deep weak layer at the base of the snowpack and the
   weak snow sitting on top of the lens formed during the end of January
   storm. The distribution of the January layer varies over the forecast
   area and has been found the most active in open glades at mid
   elevations on north facing slopes.

   BOTTOM LINE

   The avalanche danger rating today is CONSIDERABLE above 9,500 ft on
   steep east to southeast facing slopes in the Tioga Pass and June
   Mountain areas. There is a CONSIDERABLE danger rating for mainly
   northwest to northeast facing slopes above 9,500 ft in the Mammoth
   Lakes Basin. There are variable avalanche conditions parties should do
   careful route finding and put one person at a time on a slope during
   ascents and descents in avalanche terrain.

   There is a MODERATE danger rating for the Bishop Creek area. The
   MODERATE danger rating applies to southerly slopes with a previous
   snowpack, which means the MODERATE danger rating is very localized up
   Bishop Creek.

   Below 9,500 ft in the Tioga to Mammoth areas, the danger rating is
   MODERATE in all wind loaded terrain steeper than 35 degrees. The
   MODERATE danger rating means there are locally unsafe conditions so use
   good travel habits to minimize your 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.