Observation: Turnagain

Location: Seattle Ridge

Route & General Observations

Took the snowmachine up to the Repeat Offender slide path above the common motorized up-track to fill in an information gap we had in our forecast area. We dug a pit to assess the snowpack structure around the 3.14.23 interface, considering we have not seen any activity on this aspect. This is the interface that created a bunch of really big avalanches during the end of March and is our current Deep Persistent Slab problem.

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

Light east winds gusting to moderate with short bouts of light snowfall. Overcast skies but warm temps creating a longwave/greenhouse effect that was helping to melt the snow in the mid elevations.

Snow surface

About an inch of fluffy light snow on top of sun crust. The slope had a supportable sun crust and it was possible to link turns until the crust warmed up enough to be breakable at about 1500&#039.


We dug down to our layer of concern, the 3.14 crust/ facet combo buried 2.5' deep under a hard slab. This was a scoured area so the slab is thinner than many other areas. Under this slab, was a knife hard melt/freeze crust that was around 4" thick. The top of the crust seemed to have bonded well to the settled storm snow. Below this crust we found a thin layer of rounding facets that sat on top of a stronger faceted layer (pencil hard, around 1mm rounding facets). This snowpit did not have any alarming layers of weak faceted snow, which is much different than other areas. In other areas we have seen weak facets surrounding the melt-freeze crust or on shaded aspects, just facets without a crust under the March storm snow that is now a hard slab. Our stability test produced no results.

Photos & Video
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