Avalanche

Big Sheep Creek

Caleb MerrillNorthern Wallowas
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Quick report

I noted one D1 natural slab avalanche from sometime in the last week.  It was on a SE aspect around 7800'  in wind-loaded terrain.  The crown was partially filled in and the debris looked wet.  When traveling along small but steep wind-loaded features, I could easily get shallow soft slabs to fail below my skis.  I dug two pits today, one was on a NE aspect at 7600' and the other was on a SE aspect at 7200.  See snowpack obs and video for details.  

One recent D1 avalanche, likely from sometime Wednesday-Friday.

Weather

Cloud Cover
overcast
Wind Loading
light
Recent Snowfall
12
Snow Avail For Transport
small smounts

Overcast to Broken skies. Light intermittent snow. Winds remained light while I was in the field but anticipated to increase.

Snowpack

Pit 1 was dug in a protected area below a fence of trees: NE 7600' HS 235 cm/93".  There was 5" of new light-density snow sitting above a 1" melt-freeze crust.  I noted a mostly strong snowpack with several thin melt-freeze crusts and 3 different layers of Graupel throughout the snowpack.  The graupel layer that was 30cm/1' from the surface produced moderate resistant planar results in a compression test.  No propagating results in my ECT, but this same layer did have a break under my shovel.  See pit profile below.  

Pit 2 was dug on a SE aspect at 7200'.  HS 215cm/85" of snow.  There was 2" of denser new snow above a 4" melt freeze crust.  Below the melt freeze crust was a 1F to P hard slab with moist snow grains.  At 60cm/2' down, I found saturated large grains of snow that were 4F hard.  This structure is concerning and produced Sudden Collapse results in compression tests, but did not propagate in an ECT.  Hopefully forecasted colder temperatures through the week will bring some stability back to this layer.   

Avalanche

Size
D1
Aspect
SE
Trigger
N
Elevation
7800 ft

A D1 natural avalanche was noted with wind-blown terrain above the crown and a terrain feature (viewer's right) that is almost always wind loaded when I view that spot. It looked to me like it was a wind-loaded pocket, with some wet debris.