Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 3
Snow structure from the Mill hollow zone.
Here's the wind up... it's not the snow we're riding in that's the problem, it's the snow we're riding on. Remember, early season snow morphed into a weak, sugary, basal layer during the December dryspell and that mess lurks 2-4 feet beneath a supportable, cohesive slab... our midpack. What do you say, let's keep it spicy and throw in an untrustworthy and very Grinchy, Christmas Eve rain crust which now ties our snowpack together. Unfortunately, this is a deceiving layer, adding structure and supportability, but not necessarily stability. Don't forget, crusts promote a mini facet factory above and below, so we're putting all the ingredients together for an avalanche... a slab (today's storm), weak snow (thin layer of facets), and a bed surface (hard, slick, raincrust).
Now the pitch... adding yet another curve ball to the mix, the snowpack feels bomber under our skis, board, or sled but it's not. In fact, all we need to do is find a shallow spot, like around a bush or rock where we can punch through the slab, irritate the weak layer and collapse the slope, and now the entire roof is crashing down on us.
Persistent slab's are tricky and aren't manageable with a ski or side-hill slope cuts. Instead, avoidance is the go-to tool.
JC and I stomped around Campbell Hollow Wednesday and found an intriguing snowpack... weak, faceted snow near the ground is still the main player.
