In this video we shot on December 21, 2014 I get a result of ECTN 6 in my Extended Column Test. I had just remotely triggered a medium / large wind slab avalanche on approach to this area.
The “bull’s eye” data is clear; the snowpack is unstable. The ECT result is unclear; there’s a layer in there but it doesn’t propagate. What if the slide had not triggered?
We need to be aware of “false stable” results in our stability tests. A stable result in a stability test should be a small part of your avalanche assessment. What else is going on? In this case we had immediate recent activity; the snow is sliding. But, you may get unclear results in your stability tests and not have clear data like recent avalanche activity. High winds, recent loading, cracking, whoomphing, avalanche advisories and pit data are all part of the picture.
An unstable result in your stability test should be a huge part of your avalanche assessment. Unstable results clearly show instabilities in the snowpack. Sure; you could be getting a “false unstable”; but the worst thing that happens is you don’t ride or ski a slope. Relying too much on a “false stable” result might kill you.
Dudley Improta, West Central MT Avalanche Center
12/23/14
