February 18, 2017

Observations

Front Range: Rabbit Creek

Obvious signs of instability (red flags):

  • Soft, thin D1 human triggered wind slab release between steep sections of skintrack switchbacks
  • Subtle shooting cracks in fresh, thin, soft wind slab
  • Subtle, active wind loading at times throughout the day

Weather:

  • Mostly cloudy with alpine temps in the upper teens to lower 20s and generally light SE wind with some moderate gusts (minor snow transport at times)

Surface conditions:

  • In general, a few inches of soft wind-buffed powder (great FRange ski conditions).  Some exposed old, hard wind slab in places.  Exposed, or slightly dusted, ground and rocks in areas that never develop a snowpack.

Snowpack:

West Ptarmigan snowpit #1: 4300′, 229* SW aspect, 39* slope, 110cm HS, ECTP16 Q1 (Sudden Planar) down 40cm on buried surface hoar and near surface facets.  When this slab slid off the extended column it initiated another clean failure down 30cm from surface (above initial failure plane) on a density change (with possible facets) from the multiple bouts of snow and wind earlier this week.

West Ptarmigan snowpit #2: 4600′, 219* SW aspect, 41* slope, 90-120cm HS, ECTP27 Q2 (Resistant Planar) down 90cm on advanced facets, facet chains, depth hoar.