April 3, 2017

Observations

South Fork Eagle River:

Obvious signs of instability (red flags):

  • Numerous collapses (whumphs) between 2500′-4000′ multiple aspects
  • Recent wet loose avalanches on steep solar aspects
  • Somewhat recent wind and persistent slab avalanches (likely from snowfall Tues-Wed last week and the wind that followed)
  • Active wind loading

Weather:

  • Mostly cloudy to obscured skies, moderate easterly wind, alpine temps in the lower 30s to lower 20s

Surface conditions:

  • Breakable melt-freeze crust on solar aspects
  • Breakable to supportable wind affected, dense snow where not affected by sun
  • Soft, dense powder in sheltered areas

Snowpack:

Hanging Valley snowpit: ~4000′, 333* NW aspect, 34* slope, ECTP17 Q1 (Sudden Planar) down 50cm (bottom layer of 4F heavily faceted old snow surface) and 60 cm (upper layer of 4F basal facets) simultaneously (10cm 1F wind packed between failure planes), 90-115cm height of snow across pit (tested from shallow side).

*Snowpits and tests were conducted on the flank of a path that had already slid, where there was undisturbed snow.  We used the debris and bed surface for access.