Snow Depths

Now then, can someone help me out here.

I have just seen the snow depth for Val Thorens at the top and it is advertised as 200cm :shock: Cant wait :)

However, how is that 200cm measured?

Is it 200cm of the soft fluffy powder, or is it 200cm of the compacted stuff? There is a significant difference. I imagine 200cm of the fluffy stuff would compact down to less than a metre?

Answers on a postcard....or knowing christmas mail, just below will do :)

Normally measured unpisted, you can sometimes see the measures as you ride on a chair

Iceman wrote:However, how is that 200cm measured?

Pretty much all resorts have several set measuring points at different levels on the mountain - sometimes just a ruler painted on a lift pylon but usually a pole in a fenced off area where the snow is relatively sheltered.

So, generally, the measure is of settled but un-bashed (i.e. un-pisted) snow.

The density of fresh snow varies massively - one reason why it's almost impossible to predict new snow depths accurately - and it compacts quickly under its own weight, and due to the effect of temperature changes. Light powder can easily halve in depth within 24 hours of falling.

That 200cm probably represents 4 or 5 metres of fresh that has settled over the past couple of weeks.

adders knows his stuff....

Isn't it more useful to us guys in planks to know the actual depth on piste? Or would this vary too much?

Some places can't measure much more than 200cm



These days the measured snow depth doesn't really have much relevance to the state of the pistes, as it doesn't take into account the depth of artificial snow. It should be easily possible to give the depth of snow on the pistes as modern piste machines can measure it to an accuracy of 1cm using GPS systems such as PistenBully's SNOWsat System http://www.pistenbully.com/en/download/brochures/attachments.html

Admin wrote:

Iceman wrote:However, how is that 200cm measured?

Pretty much all resorts have several set measuring points at different levels on the mountain - sometimes just a ruler painted on a lift pylon but usually a pole in a fenced off area where the snow is relatively sheltered.

So, generally, the measure is of settled but un-bashed (i.e. un-pisted) snow.

The density of fresh snow varies massively - one reason why it's almost impossible to predict new snow depths accurately - and it compacts quickly under its own weight, and due to the effect of temperature changes. Light powder can easily halve in depth within 24 hours of falling.

That 200cm probably represents 4 or 5 metres of fresh that has settled over the past couple of weeks.

If it is un bashed snow, how come when it us only artificial snow it still has a depth? It at that time do they measure in piste?

Beep, how do you find these facts??

There are other complications too. As Adders points out, the measure points are often in a sheltered area. Mostly, these are in the lee area of a hill or some trees, hence there is a greater depth of depressurised snow, plus snow dropped by eddy current effect.
As Swingbeep points out, the effective on-piste depth is heavily effected by machine snow, which for much of the alps, is just as well.

Also, in many resorts, if you look off to the sides of the runs, there are huge piles of machine snow, called "whales". In St Anton, these are stored between runs, in many resorts, there are areas cleared for the purpose.

These areas may have up to 8ft of snow, but they are not on the ski routes, so are not noticed.

As the piste cover wears, apart from continuous new machine snow, the piste machines will take snow from the whales. These are then replenished, at a steady rate.

The snow depth measure is a comparitor of natural snow.

This is interesting stuff. What is eddy current effect? I am going to seem so knowledgeable when I start this discussion while I am away!