Observation: Turnagain

Location: Center Ridge

Route & General Observations

Anchorage Nordic Ski Patrol Mountain Travel & Rescue Field Overnight: Standard uptrack to about 1200′ then north into meadows.

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)?Yes
Cracking (Shooting cracks)?No
Observer Comments

We experienced isolated whumps in 10-15' diameter areas on flat ground both Saturday and Sunday.

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

Saturday partly sunny gave way to full sunshine and clear skies overnight with temps dipping below freezing. Morning sun gave way to light snow (S-1) around noon with winds and snow increasing steadily through the afternoon Sunday.

Snow surface

Over a foot of heavy new snow. Broke trail through the mashed potatoes to our regular camp location. Sun affected surface layers developed a 4cm crust overnight; In shaded areas on Sunday there was still loose snow.


We dug a quick pit on a nearby small a 30 degree southerly slope to see things looked like after experiencing a localized whumpf on flat ground where we were practicing anchor building. Air temp had just risen above freezing. HS 165. There was a notable change in grain form, size, and color 55 cm down from new snow to a large clusters of melt freeze with some facets. We had an ECTP17 SC on this layer. The new storm snow layers included a 4cm crust at the top over F hardness decomposing particles. The storm snow was wetter as depth increased. Conversely the meltfreeze layer was dry.

Photos & Video
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