Good morning, this is Sue Burak with the Eastern Sierra Avalanche
   Center with an avalanche advisory posted on Friday, April 18, 2008.

   A conditions report from the Tuolumne Rangers is posted at the end of
   this advisory.

   Inyo and Mono County road departments advise those driving past road
   closed signs that they can and often will be ticketed if they obstruct
   plowing and rock removal operations. The road to Onion Valley, Whitney
   Portal and South Lake are not officially open yet.

   MOUNTAIN WEATHER

   After a couple of pleasant spring days, its time for the weather to
   change again. There is a high wind watch posted for the mountains of
   Inyo and Mono County. These watches are expected to be upgraded to high
   wind warnings by Saturday, bringing less than ideal weather conditions
   to the higher elevations. The weekend will be cold and windy with a
   chance of snow by the end of the weekend.

   A few more degrees of warming is expected today with highs around 50 F
   at 9,000 ft and mid to upper 40s up to 10,500 ft. Today will also be
   windy at all elevations. Higher elevations will see highs in the upper
   30s and low 40s with strong southwest and west winds by mid day.

   The high pressure ridge that brought clear skies, pleasant temperatures
   and light winds is moving east. The ridge will be replaced by a strong
   low pressure system that moves into the Pacific Northwest, bringing
   more snow to the Cascades and southern Canadian Rockies. As the strong
   cold front moves through, forecasts are for 700 mb (10,000 ft
   elevation) winds of over 60 mph to mix down to the 395 corridor. And,
   as wind speeds increase, temperatures will drop 20-25 degrees from
   todays highs.

   SNOWPACK AND AVALANCHE DISCUSSION

   The spring snow season is going to last a long time if the weather
   patterns continue to shift from warm and dry to cool and windy. The
   high winds are creating a variety of snow textures. In general, snow
   above 10,000 ft is either wind hammered fine grained moist snow or a
   variety of sun crusts. Over the last week, there was one isolated
   report of perfect corn skiing down to 6400 ft in the Big Pine area. The
   rest of the eastern Sierra is not so fortunate, though most spring snow
   is fairly pleasant skiing once the sun melts the surface and takes out
   some of the ridge like corn flake texture.

   A report from a friend to skied from Mammoth to Tuolumne reported
   winter fine grained wet snow at all elevations and aspects above 10,000
   ft. In fact, he reported very little true corn snow except on a south
   aspect climbing out from Waugh Lake to Lost Lakes. Large loose
   avalanches that gouged pretty deep into the existing snowpack were
   observed on east aspects during this tour and snow conditions changed
   from slope to slope. Wind affected snow and sastrugi was reported from
   the Kuna Crest which is typical for that area for those of you who like
   the hike from Parker Lake to Koip Peak.

   Yesterdays snow pits at 10,000 ft on east and west aspects near San
   Joaquin Mountain showed some thick ice lenses over facets and wet fine
   grained snow. The snowpack was almost isothermal, meaning it is close
   to melting. Having a consistent temperature of 0C or 32F also means
   there is potential for point release slides to collect a lot of snow
   and become big avalanches.

   BOTTOM LINE
   For today, the avalanche danger rating is LOW until mid day, when the
   suns energy melts the upper few inches of the snow and surface
   instability increases to MODERATE. With another cooling trend beginning
   Saturday, the avalanche danger will return to LOW.

   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.