Observation: Turnagain

Location: Magnun - Corn Biscuit Headwall

Route & General Observations

APU Snow Sciences class went to ski the Headwall between Magnum and Corn Biscuit via the common uptrack. We observed glide cracks on southerly aspects, and wind loaded snow on north aspects under the ridges on the alpine. Skinning up on the steepest areas was slippery, so ski crampons may be in season. A melt-freeze crust was present the whole way up until 3600 ft approximately where it switched to lighter snow transported by wind.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?No
Observer Comments

Glide avalanches on Seattle Ridge on southerly aspects.
Glide cracks opened on Magnum on southerly aspects ~2800 ft
Rapid wind loading in the alpine, under ridge lines, cross loaded gullies, and convex rollovers.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Broken skies, flat light, warm temperatures near the trail head, and colder by the alpine.
Consistent moderate SW winds at the ridge top.
Inconsistent trace of light snow was observed throughout the day.

Snow surface

Melt-freeze crust until ~3600 ft.
Slightly lighter snow on the northerly aspects near the upper elevations.
Wind loading under the ridge tops 3700 ft
Trace amounts of snow were easily picked up by the wind.
Snow became decent corn at ~1700 ft at 15:30.


Big cornices present on southerly aspect on the ridge tops of Magnum. However, we did not see any recent signs of cornice fall.
Pole pronometer revealed crust over right side up snowpack.

Photos & Video
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