Friday, March 25, 2005

   Good morning, this is Bruce Tremper with the Forest Service Utah
   Avalanche Center with your backcountry avalanche and mountain weather
   advisory.  Today is Friday, March 25, 2005, and its 7:30 in the
   morning.

   Weekend Warrior Update:

   This past week we have been hit with our fifth large snowstorm of the
   winter with up to 70 inches of new snow and nearly 7 inches of water
   weight since last Saturday.  The new snow fell on top of a very hard,
   solid base, so most of the avalanches have been running on the old
   snow surface or as soft slabs or wind slabs within the new snow.
   Before the storm, there was some weak faceted snow on the steep, north
   facing, wind sheltered slopes, and people have experienced collapses
   on these slopes and occasional slides breaking on this layer.  Heads
   up for the weekend: we expect dramatic warming with sun and we should
   have a rapidly rising danger of wet avalanches this weekend.

   Current Conditions:  

   Overnight, almost no snow fell because the ridge top winds are too
   weak to push the moist air up the mountains.  Yesterday about five
   inches fell during the day.  Ridge top winds are very light from the
   south with ridge top temperatures in the mid teens.  The powder is
   good, but a bit dense above 9,500 but its pretty manky at lower
   elevations and there is a thin sun crust on sun exposed slopes.

   Avalanche Conditions: 

   Yesterday there was a couple close calls.  In a very active avalanche
   day in the Ogden area mountains, an out-of-bounds skier south of
   Snowbasin triggered a soft slab at 8,200 north facing slope and he was
   buried with just his hand barely sticking out, which was very lucky
   because he didnt have a beacon.  His friends dug him out without
   injuries.  Many of the Ogden-area avalanches have been running on a
   layer of graupel.  Also, yesterday, a skier triggered an avalanche on
   southeast-facing Cardiff Bowl in Little Cottonwood Canyon and he was
   not caught.  Also, yesterday, daytime heating triggered an avalanche
   on south facing Superior that ran full track.  Most of the activity
   yesterday occurred because more dense snow was deposited on top of
   lighter snow from Wednesday and some were triggered by daytime
   heating.  Cornices are sensitive.

   Without any snow or wind overnight, I suspect that many of the
   instabilities within the new snow will have settled out but there has
   been a huge amount of weight added to the snowpack this past week and
   I just dont trust the deeper weak layers, especially on north facing
   slopes.  Also, the winds should pick up from the northwest this
   afternoon with perhaps another 6 inches of snow and more tonight, so
   it will probably keep things interesting.  When you are out today, be
   sure to jump on test slopes, kick cornices and dig down with your 
   hand to see how well
   the new snow is bonded to underlying layers.  Also, continue to follow
   all your safe travel practices like one at a time and doing slope
   cuts.

   Heads up for the weekend: We should have a strong warming with sun
   this weekend and this will almost certainly create widespread areas of
   wet avalanches with dramatically rising avalanche danger.  This
   weekend, you definitely need to stay off of and out from underneath
   steep slopes, especially when they get wet and soggy.

   Bottom Line (Salt Lake and Park City, Ogden and Provo mountains)
   The avalanche danger remains CONSIDERABLE on slopes approaching 35
   degrees or steeper, especially with recent deposits of wind drifted
   snow, especially those shady slopes facing northwest through east.
   Other steep slopes have a MODERATE danger.  Any steep slope receiving
   direct sun today the danger will rise to CONSIDERABLE.
   This weekend, the avalanche danger will likely rise to HIGH.

   Moist air should keep clouds around the mountains today and ridge top
   winds should pick up by afternoon from the northwest, which should
   give us 6 inches of snow this afternoon and tonight.  At 8,000 it
   should get into the upper 20s.  Ridge top temperatures will cool to
   around 10 degrees by Saturday morning.  On Saturday ridge top
   temperatures will rapidly rise from 10 degrees in the morning to near
   freezing by Sunday.  Combined with clear skies and sunshine, it will
   create widespread wet avalanche activity.  On Sunday and Monday,
   temperatures will continue to rise with some high clouds.  Then we
   will have yet another snow storm Monday night through about Thursday.

   The information in this advisory is from the U.S. Forest Service,
   which is solely responsible for its content.  This advisory describes
   general avalanche conditions and local variations always occur.