April 15, 2017


South Fork Eagle River, Flute, and Organ glaciers:

Obvious signs of instability (red flags):

  • Numerous recent wet avalanches (loose and slab) up to D3 in size on south to west aspects
  • Human triggered wet loose avalanches on solar aspects (afternoon) and dry loose avalanches on northerly aspects
  • Very large (D4?) slab avalanches with VERY wide crowns in the Eagle and Whiteout glacier areas on westerly aspects (observed from Organ summit)
  • Rockfall triggered by warming on solar aspects


  • Sunny with alpine temps from the mid 40s to mid 20s and calm wind

Surface conditions:

  • Supportable melt-freeze crust on solar aspects below ~3500′ in the morning, becoming isothermal by afternoon-evening
  • Soft, dry snow above ~3500′ except on steep solar aspects (where there is melt-freeze crust that’s breakable on E aspects, supportable on S to W aspects)


Rollerballs at best and wet slab avalanches at worst on steep south to west aspects at most elevations.  Mid to lower elevation snowpack becoming generally isothermal and unsupportable by afternoon to evening depending on steepness and aspect.

D3 natural wet slab avalanches triggered by natural wet loose avalanches.  South aspect Hurdy Gurdy above the Eagle Lake marshes.  First photo: wet loose avalanche started at ~5200′ and triggered wet slab at ~4600′ with a total path of ~3000′.