| Trigger | Skier | Avalanche Type | Soft Slab |
| Aspect | West | Elevation | 2500ft |
| Slope Angle | 37deg | Crown Depth | 10in |
| Width | 30ft | Vertical Run | 250ft |
Avalanche: Turnagain
Location: Sunburst to Magnum
Ascended Sunburst standard route. No whumphing or shooting cracks. Dug a pit to 90cm hard ice layer.
Pit location: SSW face sunburst, 3300′, 22* slope, 11am
Sky: scattered, Wind: ENE 5-10mph
Did not have ECT cord so only performed CT with the following results:
CT2 Q2 @ 25cm
CT8 Q1 @ 32cm (presumed BSH)
CT22 Q3 @ 44cm
Descended Sunburst and ascended Magnum WNW ridge. Ascent ridge was scoured.
Reached Magnum summit @ 1pm, observed large cornices over Magnum S face (pictured).
Sky became Obscured with S-1 and wind 10-15mph.
Descended Magnum SW bowl via low angle snow, far south away from cornices. High quality, low density snow for descent.
Traversed around SW corner to W face Magnum briefly enroute to the Alders below.
Upon transitioning to Magnum W face, at 2500′ approached a steep rollover. Skier 1 ski cut a concave terrain feature below a rock band, intentionally cutting loose a wind slab, estimated 10″ deep and 40′ wide. Debris was less than 12″ deep, runout traveled ~250′. Bed surface was hard ice below new snow. Estimated size D1.
Skiers 2, 3, and 4 descended the bed surface with no incident.
Avalanche Details
Upon transitioning to Magnum W face, at 2500' approached a steep rollover. Skier 1 ski cut a concave terrain feature below a rock band, intentionally cutting loose a wind slab, estimated 10" deep and 40' wide. Debris was less than 12" deep, runout traveled ~250'. Bed surface was hard ice below new snow.
Skiers 2, 3, and 4 descended the bed surface with no incident.
Events of the day
Avoided crowds, skied conservative terrain as winds picked up, but upon reaching a new, unknown aspect and a small but steep terrain feature, Skier 1 performed a ski cut which triggered the soft windslab.
Weather
11am: Sky Scattered, Wind: 5-10mph ENE
1pm: Sky Obscured, S-1, Wind: 10-15mph ENE
3pm: Sky Obscured, S2, Wind unknown (obs from car).
Snow surface
New, low density snow, beginning to form slabs.
Snowpack
Pit location: SSW face sunburst, 3300', 22* slope, 11am
Sky: scattered, Wind: ENE 5-10mph
Did not have ECT cord so only performed CT with the following results:
CT2 Q2 @ 25cm
CT8 Q1 @ 32cm (presumed BSH)
CT22 Q2 @ 44cm
Hand hardness descended from F to 4F to 1F to K.
Performed a number of hand shears en route on both Sunburst and Magnum up tracks without cause for concern.
large cornices above Magnum S face
hardness profile for Sunburst SWS shoulder
skier 1 descends low angle terrain on Magnum SW bowl.