Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
An old, sled-triggered persistent slab avalanche from earlier in the weekend that broke on a shallow, shrubby, steep slope near Heber Mountain at 9,800' -- Thanks for sharing Nate. Check out more from his travels here.
The likelihood of triggering a persistent slab avalanche continues to go down, but as a rider, it is still possible to trigger a slide breaking 2-5' deep and hundreds of feet wide that takes out the entire season's snowpack. Recent avalanches failing deep and breaking wide have required big triggers like a cornice, snowmobile, or even smaller avalanches to step-down. Suspect terrain is steep, rocky, wind-affected slopes facing northwest through east that have a shallower snowpack (<3').
It is a bit like Minesweeper out there -- Although the likelihood of us triggering a large avalanche has gone down, if we play the game enough and keep putting tracks in terrain where this avalanche problem exists, we are bound to hit the mine eventually. How do we lose the game? All we need to do is find a thin portion of the snowpack around a rock or bush, collapse the weak layer (whumpf), and now we're staring down the barrel of a dangerous avalanche. Remember, today's avalanches are tricky, unmanageable slides. Instead of trying to outsmart the avalanche, avoidance is the go-to tool, and I am steering clear of this problem until it goes away or is buried deep enough and not a concern.
Ted was taking a look at things around 10,000' near the East Fork where he found a shallow, weak snowpack less than 3' that has a similar structure to that of deeper parts of the range.