Sasquatch on Dec 10, 2014
Rendezvous Lodge - Pano Cam
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Base of Bridger Gondola
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Apres Vous
Sasquatch on Dec 10, 2014
Bob Comey has been predicting the avalanche hazard for Jackson Hole Mountain Resort and the surrounding Teton and Greys River Ranges, as well as for the Togwotee Pass area to the Northeast of Jackson Hole. Few have had as much experience with the snow, terrain, and avalanches conditions that return to Jackson Hole every winter than Bob has, and on November 24th, Bob joined us for a few hours in the Teton Gravity Research Forums to answer the prying questions of backcountry skiers and snowboarders.
Bob covered the gamut, from everything from the most common mistakes made by backcountry travelers to the future of snow science to the kind of bacon to have on hand for rescue dogs. Check out the recap of his Ask Me Anything session below:
What type of bacon would you recommend that in-bounds skiers carry so they can be located by rescue dogs in the event of an avalanche? -Below Zero
Any type of bacon will work.
Can you give us a good argument why the Bridger-Teton Avalanche Center doesn’t use the Storm Snow problem as one of their common forecasting problems and every other avalanche center that uses the problems does so? Don’t you think you’re missing a crucial segment along the continuum from loose snow to deep persistent slabs? -homemadesalsa
Great question. My thought: the question for me is what is the difference, scientifically, between a wind slab and a storm slab? We know scientifically that winds make slab avalanches. I haven’t seen a good explanation of what makes a storm slab if it’s not wind. I understand that they typically fail on density differences, but what forms the slab in the storm slab? I believe that it is wind.
In our experience, if there is no wind, there is no slab, and you experience loose snow avalanche activity. I also understand that on one end of the wind slab spectrum you have a hard, hollow-feeling slab and on the other end of the wind slab spectrum you have a very soft slab that is barely a slab and quickly falls apart as it is released. I know of no good science-based explanation as to a boundary that defines the difference between a storm slab and a wind slab.
In the Tetons, the treeline extends to 10,500 feet in many areas, which is the limit of our forecast, and we have lots of open unforested areas at our lower elevations. This is different than places in say Colorado or Canada, where strong winds blast the above treeline areas and create distinct wind slabs. As far as other centers using storm slabs, up until two seasons ago, those centers used the avalanche problems in different ways and used them without definitions and with different definitions. If you have some insight on a valid science-based explanation of how a storm slab forms without wind, please point me towards that.
Do you foresee any huge advances in the future of snow science and safety tech that would dramatically reduce risk for the average winter outdoorsman? -Johnny Utah
The hurdles are understanding the mechanics of avalanche failure and the huge variability of conditions in a micro-environment (i.e. on one particular slope). Without a better understanding of the beast, I don’t foresee any huge advances in the near future. Certainly air bags and better beacons are huge, but they only help to slightly improve your chances of survival. They don’t help you to not get caught, and that is challenge.
The size of the landscape that the Center covers is immense, from JHMR north through the Tetons, east to Togwotee, and Teton Pass continuing south toward the Greys River. On the surface, this would appear to be an extremely diverse and challenging set of potential conditions. Do you feel the Center is adequately staffed and funded for this breadth of terrain responsibility? Or have other models been considered that perhaps decouple the JHMR forecasting function and focus the BTNF piece solely on the backcountry? -Tye1on
Another good question. We could never have enough resources to comprehend conditions on the scale that the BTAC covers, or for that matter, a much smaller piece of the backcountry. Other centers, such as those in Norway and Switzerland, use models that take weather data and produce snowpack profiles for remote areas. We don’t do that and that is not in our plans. Nor is decoupling the BTAC center from the resort. That information exchange partnership is invaluable for both operations and the public.
Bob, in regards to skiing on slopes under 30 degrees. If adjacent connected slopes are pushing over 35+ degrees, it’s my understanding that since you’re not on the slopes that you should be safe. Is this somewhat correct? I realize that under some conditions the rug can be pulled out from underneath you. Just trying to get this down as I know terrain is the answer… -BLOWhERPOW
Terrain is the answer and this is another good question with an important answer. When you are dealing with a persistent weak layer, your weight can propagate the failure of an adjacent slope from the flats. During these conditions (super sensitive persistent weak layer) you need to be super aware of what’s above you.
How do you feel about the current ratings scale names? -thewon
I think they are difficult for the user to understand. Most people die during Moderate or Considerable hazard, so it’s not intuitive that you are most likely to die in a level 2 or 3 on a scale from 1 to 5.
Will you take my pass if I poach Jackson faces? Cause man that shit is tempting early season when you guys got your hands full getting the upper mountain going. Thanks for all the good work dude, to you and all the early risers on Jackson Hole Ski Patrol. -beer30
You’re welcome, and I like your enthusiasm. You should obey all closed signs, and I hope to be busy getting the mountain ready. It would suck though if I had to take time to deal with a poacher that I could be using to get the hill open.
I saw a great NOVA special on landslides and using probes, lasers, etc., they showed how they could predict them to the hour in Switzerland. I’ve always wondered about some sort of whip antenna-like probe that could sense movement or weakness, do you think we’ll ever see something like this for avalanches? –Big Daddy
The Swiss did some research that is very preliminary but indicates snow crystals may make a distinct sound that can be recorded by instruments as they are in the process of breaking before the onset of an avalanche release. It may eventually lead to something. I like the whip idea and hope the Swiss pick up on it.
Do avalanche forecasters have groupies? -spook
Unfortunately they look like you.
What do you think is the most common mistake that seasoned BC travelers make in avalanche terrain? -TahoeJ
Not recognizing really unusual conditions in familiar terrain.
Is there more energy put into developing models and collecting information for experts, or into figuring out how to get people to stay safer in avalanche terrain?
The Swiss and others put a significant amount of energy into modeling snowpack. Most centers spend energy collecting data for experts. All centers including the Swiss spend a lot of time trying figure out how to best way to communicate knowledge to users. They are models for mountain ranges, but intuition is the bottom line.
I ski in the sierras. Often we boot up steep couloirs in powder, after a storm. From a slide perspective, is it safer to boot up the couloir, or climb up the shoulder, then drop in the couloir? -rod9301
Tough question. I don’t really know how to answer this one. It’s beneficial to see conditions in a couloir before you enter, as in hiking up before you ski it. I would not say that snow is better anchored in a couloir than on an open face. Depends on the couloir and the face. I don’t ski the Sierras, but would like to.
Did you guys score an Avatech penetrometer for this season? Use it yet? Initial thoughts? -Telebobski
Yes we did. We got one very late last season, so late we didn’t use it. We will have one to demo in December. I’m looking forward to using it. My initial thoughts are that it could be a helpful tool, but it would be just one small tool in a large tool box.
Maybe folks would like to hear what all goes into making up your daily forecasts. What time you start the day and how much coffee goes into the? –Halsted
Hi, Halsted. I get up at 4 AM. Then I view overnight data from weather stations and weather forecasts. Drive to lab, then review the latest avalanche and field observations. Get out the dartboard and make stuff up. Run routes. Visit study plots and the backcountry. Then I submit afternoon observations. Create an evening forecast, eat and drink. Sleep a little and repeat.
My question is around approach. I tour in the central wasatch and after a mixed history of helping rescue in a fatal slide followed by shunning the backcountry for a long time I’ve adopted a new mantra: Mind the rose and don’t over think it. Avoidance is key and if you respect what the avalanche rose tells you, I believe you eliminate a large portion of the risk of touring on a particular day. In practice, this means simply not skiing considerable or worse conditions with fatal exposure. Open bowl? Okay up to a point, but no bad downhill exposure with considerable avy danger. Moderate danger? Nothing very technical (ex. double fall line with exposure, multiple cliff bands below, etc) but larger lines with some exposure are ok. Any input or critique is welcome -Bromontana
Thanks, and a really great approach. One that comes from a real life experience of how bad a tragic accident really is. The comment I hear when I visit an accident site with the survivors is “If I only knew how bad this could be, I would have approached this instance differently.” It seems really difficult to get someone who has not witnessed such an accident to understand what that outcome feels like and how it would affect the decision you make. Getting steep, deep turns are nothing compared to living the rest of your life.
Ever been caught in a slide? What was your mistake if so? What did you learn from it? -TahoeJ
Only small slides. Just missed getting taken out by a big slide on the Headwall at the Jackson Hole Mountain Resort on Super Bowl Sunday quite a while ago. A poacher (my roomate – Jimmy Zell) set it off. RIP Jimmy!!! Lesson learned-stay above your roommate!
