Poster: A snowHead
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What with all of the "where's the snow?" discussion, it got me thinking about, if you managed a ski station, how much base you might hope for to be able to successfully manage the variables of temperature, precipitation and number of visitors, such that you could survive your stated season duration.
I am assuming you'd need less base on an Austrian meadow than on a Haute-Savoie escarpment above 2000m, but what makes for a base layer which can support not just your opening dates, but also provide a sound platform on which to lay down later snowfall such that avy risk won't be at 5 all week, every week?
This may be a "how long is a piece of string?" question, so apologies in advance for all the one-line "who knows?" responses.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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@zammo, I'm not quite sure what you're asking?
"Base" is not so well defined in my head...
If you have a reasonably typical alpine cycle of something like 4 days snow, 7 days fine, and it's normal winter temperatures, then you'll see a gradualy and lumpy build up of snow depths through the winter months.
If you're sitting in France at the start of the vacances scolaires with a blocking high sitting in the wrong place, you know you'll be toiling hard to keep the pistes in good nick for the required 4 weeks, after which you can sort of relax a little bit.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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I'm not entirely sure what is meant by 'base' either, I assume the depth of snow to enable the piste to be sufficiently prepared to be open. From what I can see of recent activity on the webcams the pistes can go from green grass to open and skiable within 24 hours purely by using snow cannons. Any natural snow fall on top of that is a bonus of course.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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I think the term "base depth" is wot you are after.......
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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So by 'base', in this context, I mean "the depth of (ideally) early-season snow, falling directly onto the ground, that will provide sufficient ground cover to support the inevitability of a longer-than-desired dry spell, and a layer to which later snowfalls can bind effectively, thereby providing a more stable snowpack in the backcountry".
It may well be a question to which there is not an answer. But I was curious. For instance, I imagine that many resorts currently have less base depth at this early stage in the season than they would like; what implications does this have for a resort to maintain cover later on and to predict avy risk levels come touring time?
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You'll need to Register first of course.
You'll need to Register first of course.
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There isn't really any such thing as a "pre-season base". Snowfall adds to the existing snow-depth whether it falls before the lifts open or after.
A more relevant question might be the consolidated depth at the point where temperatures start to rise for Spring (around the beginning of March). Resorts probably have an idea of the minimum depth that's going to last them comfortably through to closing day, but it will vary significantly from piste to piste (depending on steepness, aspect, underlying terrain, etc.).
Equally, in the off-piste, a thin snowpack does not necessarily mean high-avalanche risk on its own. However, a thin snowpack combined with consistently cold temperatures will lead to the formation of a dangerous amount of depth hoar (snow crystals transformed into non-cohesive faceted grains) - as happened last year when we had a cold and snowy November, followed by a cold and dry December.
This year, the snowpack is thin but mild weather and rain to altitude have lead to a snowpack which is close to isothermic (like a Spring snow-pack). This has already started to change in places and will continue to do so as colder, snowier weather returns. The next couple of weeks are likely to be very important in determining the avalanche risk throughout the rest of the season. The ideal situation for a safe snowpack is for the snow to come in one, abundant dump, as happened in December 2011, meaning there is very little chance of depth hoar formation.
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