South Fork Eagle River: North Bowl
Toured up the North Bowl standard up-track. Found a stiff wind crust 2-5″ thick with softer snow beneath. No noticeable cracking, collapsing, or whoomphing; however, there was a recent natural avalanche in North Bowl caused by a cornice fall.
Multiple skier triggered avalanches observed in North Bowl at 3,600 ft N-NW aspect. The first skier triggered a 1 ft. slab that knocked her over and carried her around 100 yards. Second skier triggered a similar slide but managed to dig in at the top of the slide.
The information below is from the party that triggered the aforementioned North Bowl avalanches. It was originally submitted to the Chugach National Forest Avalanche Information Center. It has been edited by the Anchorage Avalanche Center:
|Trigger||Skier||Avalanche Type||Soft Slab||Aspect||North Northwest|
|Elevation||3900ft||Slope Angle||32deg||Crown Depth||10in|
The first skier to descend triggered a soft wind slab avalanche on their 4th turn, about 20m down the slope. The visibility was so bad it wasn’t obvious an avalanche was happening at first. The first skier was knocked down and carried in the sliding soft debris for ~200′. Equipment was lost, but no burial. Skis were found lower down the slope on the surface of the debris. At this point it was difficult to see the crown, track, or runout of the avalanche from the ridge because of poor light. The second skier followed the first skier track and made 3 turns on the flank of the avalanche path trying to get to the bed surface of the 1st avalanche to go down to the first skiers aid. A 2nd D1 size avalanche was triggered that knocked the second skier down and carried them ~10ft before they were able to arrest on the bed surface and let the debris pass. The avalanche started on a 30+ degree slope, and ran downhill slowly until it stopped where the terrain becomes <30 degree.
Overcast skies, temps in the 20s, light winds with occasional moderate gusts. Just before ski descent and avalanche was triggered; winds became moderate on ridge with light blowing snow, light snow falling, and visibility became very obscured.
Variable (scoured to ground, hard wind slabs, new soft snow)
Various old wind slabs and newly developed soft wind slabs on steep shoulder of ridge on approach. Snowpack is variable across the terrain: hard and thick wind slab, breakable wind slab, soft snow, crusts, scoured to ground.
Looking up towards ridge from debris pile:
Debris and start zone from 2nd D1 avalanche:
Part of the crown from the first avalanche triggered: