Avalanche: Douglas Island

Hiked up the west shoulder of Jumbo planning on skiing something in the sun, particularly suspicious of north aspects based on all the recent avalanche activity on Stuart, Fruit Bowl, and South Douglas. Natural crown line in the Jumbo Chute observed from sea level was expected to be only in the lower runout of the chute, but when we got a better view of it found that the avalanche had started at the top entrance. Could clearly see that the entire chute had ripped out at some point in the past week, and had refilled with the most recent snowfall. Probing at the crownline at the top revealed a firm layer 135cm from the surface. A compression test adjacent to the crownline found a resistent planar shear at the same depth, 135cm from the surface. A botched extended column test (cut too thin) gave us a sudden planar propagation at this layer, but on the second attempt with proper dimensions in the ECT block, we were not able to get any results on this layer after 30 taps. Should have done a Deep ECT but moved on to try the compression test instead. Upon investigation of the CT shear interface at this 135cm layer, found 1mm near surface facets. This is the most likely candidate for the weak layer that has produced all these recent north aspect avalanches on Douglas.
Also got test results on a graupel layer 70cm deep between wind packed rounds.