Tuesday, February 10, 2009
All Hair and No Air
So yesterday we recieve 20-24 inches of snow in 24 hrs or less. So that computes to around 1 inch per hour. Hopefully that sets off a red flag in your brain of a elevated danger. Yesterday mid day the Utah Avalanche Forcast Center raised the danger to Red or high. The danger here is the RATE of accumulation. Its not neccessarily the amount, but how quickly it came in. Anytime you hear the 1 inch per hour number you should start to pay attention. Remember that storm a few years back where we got 100 inches in 100 hrs? Ya, lots of bad things happened because of the RATE that the snow accumulated. Slabs don't mind getting new snow, but they need time to adjust to the new weight and to consolidate. As Bruce would say, a slab is like a rubber band if you stretch it our and touch it with a knife blade it will snap, (or add lots of snow to a snow pack quickly) but if you add it slow and give it time to adjust to the weight and consolidate properly its like touching the knife to the same rubber band when its not stretched--nothing happens. That being said we also had a storm beginning at high temps and slowly cooling. (Hopefully we learned from 'the perfect storm' that this is usually a good thing. That being said if you look at the temperature stations throughout the Wasatch you'll notice that if you get high enough (Flagstaff, Collins, etc.) the temperatures never got about about 28 degrees. This tells us that at that level, the new snow isn't going to consolidate as well to the old hard, suncrust as it did lower. Also check the winds over the storm cycle and you would also notice the the wind loaded mostly from the West moving from North West to South West of the high wind cycle then slowing to an insignificant level.
Just to step aside here for a moment to mention a pet peave (sp?) of mine. If you where writing a synopsis about Wind in some type of Forecast it might be a good idea to mention the direction of the wind as either FROM or TO. If you don't, or there is no preset standard, that is readily available to the ignorant public then its almost a useless planning tool because you've got a 50/50 chance of getting it right! My uneducated opinion would be to ALWAYS state it as a TO or FROM as to cause no confusion for those who are not in your loop.
So the most loading would be found on the East aspect (and I might add the best skiing). So to summarize if I was skiing I would try to stay on the higher, but not too high elevations in reasonable protected terrain at a reasonable angle at either below 35 degrees or significantly above 38 degrees using stability tests to check out your current slope. Its OK to ski cut soft slabs (new snow creates soft slabs, but are usually on top of hard slabs) but never ski cut a hard slab. Reason being a soft slab usually releases AT the trigger point (the skier) where as a hard slab usually releases ABOVE the trigger point. If you are ski cutting, make sure to plan your escape route, ski fast and don't fall! (back in my professional days we where ski cutting a steep 38 degree slope and deep new snow section and I turfed it in the middle of my ski cut. The I wolloed for a good 5 minutes to get right side up in the deep powder, not one of my safest moments and of course was followed by relentless heckling) Cornice kicking is a very effect was to test slope stability but the key is again, don't fall onto the slope by either breaking the cornice out from under you, or kicking it off and then losing your balance and falling headlong onto the slope. A refrigerator size cornice is perfect. Make sure you do this on an accurate representative slope, or the same one you are skiing. (Same aspect, angle, elevation, anchors) A note to remember Cornices ofter break much farther back than you expect so start really Conservative and work your way closer. Oh, and of course get a belay. The other option is to saw them off with a snow saw or a peace of cord. The cord being my personal choice. We did both a cord cut cornice and the stamp method today with good results. My favorite method for cornice removal is explosives, but unfortunately they don't just let anyone carry those around these days. So where did we decide to ski today? East aspect, 37 degree average angle with a steep point of 41 degrees. A perfect recipe for disaster right? Yes. Good thing we did multiple stability tests with cornices and ski cuts. This combined with Drew's forecast (http://utahavalanchecenter.org/advisory/slc) today gave us enough faith in the snow pack to give it a run. I would normally disclose our location but I've recently been getting some feedback that people may be skiing my secret stashes of good snow, so I won't be disclosing our location do to our NEED for huge amounts of powder to share with only the select few who we ski with. Not to mention its a long, long skin in with a dicey exit and for 4000ft of climbing you only get a good 1000ft vertical run (although I might add it is, well... Nirvana.)
So after a big climb, a lot of trail breaking we reached our own special powder park, if you will. After doing our stability tests we jumped in to ski (of course one at a time from safe zone to safe zone). And as has been my experience with this place, it was steep, and very deep. After the first few turns my face was freezing and I had to remove my sunglasses because they where covered in snow, I would have been gasping for breath except that I was skiing with my Avalung in. A skill I've found more and more useful. Most people describe this phenomena as 'face shots.' Well worth the hike. After completing or first run, we are all smiles and covered in snow.
After this the story has a short section of disappointment. After setting the return skin track to the top (not a small task) we show up at the top and a gang of 4 skiers had arrived at our secret stash. One in particular was the Wizard of the Wasatch. If you know this particular skier, he doesn't exactly have top notch people interactions skills. He greeted us with profanity and then quickly 'hucked' himself into our , tested, and designed personal powder stash that we had labored on not just to test but also to put in the skin track for. Unfortunately the Wizard has more Hair than Air, as one of his friends pointed out. After that his 3 friends jumped in to remove all available untracked sections left. Nice, work... If I recall I think the Wizard had a post about someone following his skin track up to Silver fork (or somewhere near there) and then stealing his line... We then decided to change to a north aspect and we skied a HUGE line into what I'll call A-basin after the ever overrated ski resort in Colorado. The snow wasn't as deep, and had a weird layer in the middle that made it feel like upside down snow, but it was still a good time with snow that was worth skiing. At the bottom of this line the signs where there to tell you we where sitting in a massive slide path. The tree's where flagged to like 40 feet up (all the branches had been removed except the down hill side) and the center or runout had only little short trees or no trees. (meaning that the slides have been removing them) I should have a good photo of this. We then skied out to a car we stashed at a different canyon. All in all, another stellar day in the Wasatch.