February 14, 2016

Observations

Front Range – Ptarmigan

Obvious signs of instability:

  • Wind loading from moderate easterly wind
  • Small, D1 human triggered avalanche

Weather:

  • Cloudy to obscured skies with temps in the 20s, moderate easterly wind, and intermittent light snow

Surface conditions:

  • Melt-freeze conditions below ~2750′
  • Fresh, wind-affected snow above ~2750′ ranging from firm, supportable, wind slab to carve-able wind-packed powder to relatively loose, slightly wind buffed powder that sluffed off steep terrain

Snowpack:

Ptarmigan West face snowpit at ~4250′, WSW aspect, ~35 degree slope, ECTX (handpits with column tests to ~4750′ revealed faceted layer in top ~2′ of snowpack that required moderate force to release).  Small, D1 human triggered avalanche on cross-loaded terrain feature NW aspect ~4000′.

Snowpit location at ~4250′, WSW aspect:W Ptarm snowpit

Stability assessment on belay in consequential terrain:ptarmigan on belay