March 17, 2017

Observations

Portage:

Route:

  • We linked up Baird (summit descent via SE face), Carpathian (descent via NE face just below rocks near summit), and Byron (descent via NE face from N summit) peaks via the Burns, Whittier, Portage, and Byron glaciers.

Obvious signs of instability (red flags):

  • Numerous very small human triggered soft slabs multiple aspects on steep (35*+) terrain from March 15-16 overnight accumulation of several inches new snow (upper Portage glacier and Carpathian peak area had most new snow (wind loaded to well over 1′ in places).  On Baird SE face these ran on very firm windboard and sun crusts.  On Carpathian and Byron northerly aspects they ran on firm windboard.
  • Active wind loading from the N-NW through the morning in the areas of upper Burns glacier, Whittier glacier, Baird Peak, and other exposed high peaks.

Weather:

  • Clear, sunny skies with alpine temps in the teens and generally light northerly wind (moderate in more exposed/channeled areas)

Surface conditions:

  • No noticeable new snow (from March 15-16 overnight isolated accumulation) from visitor’s center to Burns glacier.  Trace of new snow noticeable on lower Burns glacier, and increased with elevation gain.  Sheltered upper Burns glacier had significant new snow and old sastrugi was smoothed over.  Baird SE face was primarily slide-for-life very firm windboard and rime ice with pockets of soft and reactive (to human trigger) wind slab in catchment areas (very small, predictable, and manageable soft slabs triggered here on ascent and descent).  Whittier glacier had generally had several inches of new snow, but large sastrugi formations were only smoothed over in the most sheltered areas.  Carpathian NE face varied from very firm, chalky windboard to varying depths of soft, new snow (over 1′ in wind loaded catchment areas).  Upper Portage glacier had a remarkably nice deposit of sheltered, smooth new snow several inches deep.  Byron E aspect (our ascent route) generally had a few inches of new snow and was mostly smooth.  Byron N aspect from N summit was quite variable with slide-for-life rime ice and windboard, as well as pockets of powder.  No noticeable new snow from mid Byron glacier back to visitor’s center.

Snowpack:

  • Only concerning instabilities were shallow and at old-new snow interface.