Wednesday, February 4, 2009

A marginal Wasatch experience.

Today was one of those fun informative days--not because of the skiing. If you've been out recently in the Wasatch, you probably already know that the South aspect, or anything close to that is corning up, or has already reached corn stage. The North aspect has settled out significantly to about 20-40cm. with reasonable skiing conditions. You can tell the Inversion is in (not just because you cant see across the valley, or the ice on your window)because the high elevation snow is showing signs of higher temperature bonding (really its just happening faster than normal). Good for the snow, not so good for the skiing.

If, like me, you decided to skin up a South Face early in the morning before it softened up (bad idea) you quickly became aware of the rock hard sun crust that has developed, and the sheet of ice that the skin tracks have become. Needless to say that was a very painful skin to the top of davenport. Next time, take off your ski's and boot pack. If its too hard to skin, then its perfect for booting.

Apparently people have forgotten how to properly ski corn. Its a timing thing: You ski it after the surface softens up, but not once the whole snow pack fills with water. Bruce would say if your booting and you sink up to your knee, then you need to be off the slope. I'd say if it feels like your skiing in 12 inches of mash potatoes your too late. The idea is to not ruin the surface for future skiers, but to preserve it for many good corn days to come. To review. You just want the surface to soften slightly enough for good turns but not so much that your skiing deep potatoes. Another clue that its too late is if you keep hooking up in the back end and losing control. Easy fix? Change aspects slightly to one that hasn't had as much direct sun yet. You can micro-manage your corn depth by this one trick, not to mention you wont leave huge ice jumps for the next guy to brake his knees on.

Instead of skiing today, I really spent most of my time doing a full blown snow profile. Mostly because I was so annoyed by the skin up I didn't really want to ski much! Anyway, here it is. Actually, its a pretty good snow pack compared to what we started with. If we where in Colorado we would have been done on the the North aspects until spring, luckily we ain't in Colorado.

A few notes to mention on the profile:
1. Facets near the ground is normal in most snow packs because the ground heats up the snow from below creating a temperature gradient between over a short distance near the ground. Because of the depth of pack (180cm) its unlikely that it would fail at the surface (although if it did it would be one big mother of a slab, not likely survivable) When we move into spring conditions this will be something we want to watch. Watch for trigger points like rocks, trees, things with a shallow pack that are surrounded by facets, or old, big slide paths that have much shallower snow packs. Below you can see the facets from the ground are actually rounding out pretty well, and are somewhat bonded.

2. The Rain crust is the coolest! But its not really a fear at this point because of how the new snow bonded to it on the following storm; of more interest would be the facets under the rain crust, but again they are pretty deep and its unlikely for a slab to fail that deep. Below is a bad photo of the rain crust.
3. Between 100-115cm there is a interesting hard layer of snow that my feeble brain can't seem to remember, but I would guess its from the extended warm section in January. It also had a harder layer at the top that I was unable to isolate, needless to say I'm pretty sure it was the temperature crust from January.

4. Finally, there is some serious surface hoar (I'm told anyway) in certain places. I didn't see any today, but that because of where I skied. I would be suspicious of it anywhere you have a good clear view of the sky in a cold place (the bottom of drainage's) or places that receive only light wind.

Ski recommendations? Go rock climbing, in the desert, maybe it will snow again before spring.

1 comment:

  1. Click on the Images to make them big, you can get a good view of the profile AND the crystals.