Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Very Likely
- Größe
- 3
Ted visited the Humpy Drainage Monday and noted these recent sled triggered slides in terrain that fits our bulls-eye profile.
From tip to tail, polar aspects at all elevations, harbor our most recent problem child, the well preserved and aptly named January Drought Layer (JDL). This faceted snow is extremely weak, and teeters on the edge with last weeks colossal storm... 2'-3' of snow and up to 3" of SWE, and now an additional shot of snow, water, and wind stretches the rubber band once again. Flip aspect and you'll find solars present predictable, old heat crusts.
A sub-committee last night with avy-savvy, snow pro and partner in crime (though we are not criminals :) Andy Nassetta and I parsed out three distinct categories of elevation and aspect-centric snowpack structure. Here's where it gets tricky... packaging the problems was easy, but neatly wrapping up the avalanche dragons with a bow and making them all tidy is a challenge.
First- alpine terrain that avalanched early in last weeks storm cycle will be quick to come back to life and reactive to our additional weight, especially with today's added snow, water, and wind.
Next- mid and upper elevation, wind sheltered, polar terrain that harbors very weak surface snow that faceted during the big January drought. That'll take a little more weight before it fails, but the avalanche we trigger is gonna break deep and wide and it's gonna be dangerous.
And finally- low elevation, north facing snow is moist and the January NSF is a little irritated with the spritz of overnight rain.
Bringing it full circle, when I think of bullseye terrain where I could trigger a dangerous slide I'm thinking low on the slope where a big roof and a warehouse full of snow hangs above me... all I need to do is knock the legs out from underneath. Places like Currant Creek Peak, Heber Mountain, Mill Hollow, Wolf Creek Bowl, or Humpy Creek come to mind. I'm also thinking about cut-banks, gullies, and small terrain features that we usually don't consider twice about playing on, but our current set-up is deceiving and this terrain fits the mold.
We typically would view the slope on the right as being more intimidating, and scary when it comes to avalanches, but the slope on the left is where our greatest concern lays... protected, wind-sheltered terrain is where a majority of our human-triggered avalanches are occurring and snowpack is most reactive.
