Observation: Turnagain

Location: Sunburst Treeline

Route & General Observations

Toured to high point of 2,300’ to assess active storm accumulation and reactivity of the Dec 1 layer.
Great low density surface conditions for any method of glide with 2” to 5” of fresh accumulation.
Instability tests showed moderate to hard results overall with propagation potential.
Great to see a refresh!

Red Flags
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Observer Comments

No cracking, collapsing
No test slopes performed
Rapid loading and wind gusts AM to midday.
Easterly plumes observed on Magnum upper ridge.

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

Overcast trending to obscured in AM with sun trying to break through broken skies by 13:00.
Light to moderate N wind (10:00-12:00) shifting to light E with sporadic gusts of 20 to 25 mph.
Active wind transporting 1,800’ and up.
S2 at 10:00, 1000’ to 1,500’
S1 at 11:30, 2,000’+
No riming observed

Snow surface

900’ to 1,200 ’: 3” to 4” of new, moist
1,200’ to 1,800’: 4” to 5” of light, low density
1,800’ to 2,300’: Ranged from 4” to 5” low density to <1” over wind effected, hard, supportable surfaces on exposed terrain.
Wind skins were actively forming above 1,800’
Ski/Boot: 30/60 cm


My focus was to assess storm snow and reactivity of the Dec 1 melt-freeze crust/facet layer, which is generally 2.5’ to 3.5’ below surface at treeline.
Instability tests at 2,100’ showed results of moderate strength, with propagation potential.
Compression tests showed broken and resistant fractures on an existing rime layer, now 1’ down with moderate results, as well as hard results on the Dec 1 layer.
ECT’s showed propagation on both the rime layer and the Dec 1 layer with moderate results.
The propagation of the Dec 1 layer, fractured within the center of this 20 cm thick ‘ sandwich” on clustered melt forms and facets showing a rough, broken bed surface. (See profile photo)
A temperature gradient is present within the Dec 1 layer.
No surface hoar was observed.
*See Snowpilot*

Photos & Video
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