09-10

With several inches of new snow and strong winds, newly formed wind slabs can be found near ridgetops and other terrain features where wind-blown snow collects.  Ski patrollers at Big Sky found wind slabs 4-6 inches thick while a few were up to a foot thick and were easily triggered with ski cuts.  Eric and I skied Saddle Peak yesterday where we carefully avoided any wind-blown snow knowing that even a small avalanche could cause serious injuries if it swept us in to trees or over rocks.  Fortunately fresh wind slabs are relatively easy to identify and avoid.

Last week stability assessments were easy.  Avalanches occurred on many slopes and the snowpack produced noticeable collapsing and cracking.  These were clear signs of an unstable snowpack.  The situation has changed as the snowpack has adjusted to the weight of last week's snow and avalanche activity has diminished.  Unfortunately the structure of the snowpack responsible for recent avalanches has not changed, and recent warm weather has not affected weak, faceted snow buried 2-3ft deep.

Mark skied into Mount Blackmore yesterday while I rode into Lionhead to document the carnage from last week's avalanche cycle.  Mark and his partner found 3-4 feet of snow on the ground with the lower half being facets.  His stability tests showed some strengthening and he did not see any obvious signs of instability. The northern Gallatin Range received less snow than other areas last week.  Although the scale was tipped and avalanches occurred, they were not as numerous or widespread as other regions. 

Today is the sixth day in a row without snow.  This quiet period gives the snowpack a rest and allows it to adjust to all the new snow from last week.  Most avalanche activity usually occurs during and immediately after a storm.  This avalanche cycle was no exception.