March 22, 2017

Observations

Front Range – Rabbit Creek & South Fork Campbell Creek:

Route:

Rabbit Creek trail, to Ptarmigan west face gully, to west ridge, to west summit, to saddle, to east summit, back to saddle, descended north face (S couloir), ascended north face (S couloir) back to saddle, climbed back to west summit, descended west face back to Rabbit Creek trail, took trail back to trailhead.

Obvious signs of instability (red flags):

  • None observed

Weather:

  • Clear, sunny skies with alpine temps from the upper 20s to lower teens (decreasing temps with increasing elevation – no inversion) and generally calm to very light northerly wind

Surface conditions:

  • Highly variable
  • On solar aspects in the Rabbit Creek valley: Mid elevation (below brushline) sheltered areas have nice, soft recycled (faceted) powder that is starting to warm up enough to develop into melt-freeze – especially where steeper and more solar exposed.  Mid elevation (above brushline) exposed areas are generally firm, supportable windboard with varying levels of sastrugi (in many areas with a thin layer of faceted snow on top).  There are some breakable patches, but they seemed rather isolated on my route.  Not really warming up enough yet to significantly improve the riding.  Upper elevations have nice chalk on firm windboard in more sheltered areas, with exposed areas being more boilerplate, and isolated patches of breakable windboard.
  • On northerly aspects in the South Fork Campbell Creek valley: Mid elevation areas vary from breakable to supportable windboard based on how sheltered or exposed the micro terrain features are.  Upper elevations range from chalky, carve-able windboard (nice) to boilerplate.
  • Most of the S couloir is slide-for-life; a fall would be disastrous – especially above the Hooker’s wall where there is serious exposure.  Variable snow adds to the seriousness…
  • Hooker’s area is very dry, and I didn’t notice any alpine ice scanning the Ski Tracks climbing area while climbing back up the S couloir

Snowpack:

The snowpack is generally very “stale,” and nothing really seems reactive (minus very, very small micro wind slabs).  However, there are some pockets of hollow sounding-feeling hard, wind slab in the S couloir which were avoided.  These were mainly in the exposed area below the saddle and above the cliffs.  If one of these persistent slabs were to fail with a human trigger, it would likely equal certain death given their size and the exposure.

Many areas harbor a P hard wind slab with ~1cm of heavily faceted snow on the surface.  This will be a serious issue on multiple aspects once we receive more snow; slabs on this bed surface and weak layer are expected to be VERY reactive.  This setup exists on multiple aspects.

Additionally, the varied surfaces on solar aspects (sun crusts, radiation recrystallization, faceted snow on firm wind slab and boilerplate) will create further avalanche problems with new snow.

When we receive new snow, the danger will increase significantly!  Approach the mountains with caution once we get a refresh!