Wednesday, April 11, 2018

Why Snow-Pits are Bull


Snow-pits are like sex: 

1 NO means NO . . . . . 5 GO's (minimum) means MAYBE


Ski tracks on the left, skin track on the right. For an aerial view see next photo (about 1/2 way down), which looks flat but is actually at the point where I'm entering the pitch-angle which is prime for a slide (27 degrees at mid-slope (next photo) to 37 degrees at bottom of photo). In my grumpy-old-man opinion (take or dismiss at your discretion), breaking trail on that skin track provides much, much better info on snow pack stability than digging multiple snow-pits (and wasting time and getting soaked). I'm not just lazy, I'm so lazy that I try to gain the most education with the easiest obtained, and widest breadth of data. Breaking trail does just that. Step, probe, watch, listen and learn.
  

Upper Rectangle where it opens up off the tight ridge. Here I'm nearing the rollover on the face, where I'm always a bit nervous about starting a slide. The angle steadily increase from flat (on Rectangle Peak) to 27 degrees here to 37 degrees at the base of the open slope. Yeah, it looks flat from this aerial view, but look at the previous photo for a better perspective on the real slope angle. This is in the prime angle for a slide, but I bank on the lower elevation, westerly aspect and breaking trail. A wily sense for stability can be gleaned from same-day trail-breaking (same hour preferably), to get you to your ski run. I hear of folks who regularly ski the Central Wasatch (Big, Little and Millcreek Canyons) who have miraculously NEVER broken trail. Given that, and the huge number of B.C. skiers these days, I am stunned and amazed that there have been NO avy-deaths in the Central Wasatch the last two years. After years of digging pits, I'm convinced that trail breaking and being acutely aware of the sound and site signals that come only from breaking trail, give one much, much, MUCH more information on stability than one or two or three bull-shit snow-pits.  The problem with the "pit mentality" is that a snow pit gives you a tiny, minuscule, pin-prick of information in an incredibility huge universe of data. The information gleaned from one pit can be, and often is, completely different just 100 yards in another direction.

Yes, pits are all the rage and they do serve a purpose. But put it in perspective and don't bank on very little data. The professionals don't. One, two or even five pits is not nearly enough to stake your life on. Breaking trail in virgin snow is a much better source of overall data. Pits are good only in huge numbers. Keep in mind how avalanche forecasts are calculated. The results of many, many pits are provided by many, many observers, coming from many, many different locations, aspects and elevations. These results are then summarized as a general consensus and overall avalanche rating for the next day, provided by the Utah Avalanche Forecast Center. Read it every day and don't be afraid to say no to your dumb-ass buddy who wants to ski everything just one day out from a 20 inch dump.



3 comments:

  1. Pits are no longer just limited to CT tests, which do indeed have a lot of spatial variability and are only particularly helpful when done in large numbers. There are plenty of tests, ECT and PST for instance, that do not measure spatially variable aspects of the snowpack. In addition, it's a great way to get up close and personal with the snow and its layers.
    Is trailbreaking a fantastic way to analyze the snow? Yes. Do people over-rely on pits? Sometimes yes. But snowpits are not useless, and they're not "only good in huge numbers."

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  3. Nick, just saying too many time I've watched folks hike like mad, dig one pit and pretty much ignore every signal along the way except that one pit, which is a pinprick of evidence. They pretty much have their minds made up before leaving home about what they're going to ski, regardless of the conditions. Pits are great, but the tendency is to overemphasize what they may or may not indicate.
    Earlier this year I shared trail-breaking duties with some folks I met at the trail head. For two hours we saw shooting cracks and heard continuous collapses. When we got to the top they dug one pit, 'hooped and hollered' when they got the result they wanted. They smirked when I said I was skiing the 20-degree meadow on the other side to the drainage. I watched them ski a 38-degree, north facing slope, setting off two small, but burial-sized slides. They lucked out and weren't caught. Luck was the winner that day, all education was ignored.

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