J2Ski Forum Posts and Replies by Dave Mac

The maximum snow conditions are when the temperature is just cold enough to form snow. Warm air holds more water vapour than colder air.

When the air temp gets really cold, water vapour content decreases, and there is less precipitation. Hence the snowflake sizes become smaller. So it may snow heavily at + 2 deg, but much less at - 2deg.

Hence, even at -5 to -7 deg C, the snow is in the form of tiny shards of ice. There is much less deposition.

Also, when the ambient temp is really low, there is less air rise from the ground, hence little movement of ground source water vapour. This condition further decreases snow deposition.

To answer the question, it can't be too cold to snow.It just depends on when you stop calling it snow.

Pray for cold weather, but not too cold!

Iceman wrote: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!

Eddy current occurs when the snow is wind driven, over an obstacle, (trees, rock, small hill, crest) and a partial vacuum is created behind the obstacle.

Sometimes you get to see it, the snow is roaring over the obstacle, and then curves down and backwards into filling the vacuum.

In Scottish resorts they erect snow fences, and the snow is held captive in the low pressure areas behind the fences.

It's one reason that the best powder is always found right beside the treeline, on the lee side.

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.

The Post Office is offering 1.17, same with Travelex, M&S are 1.15, so where are you getting 1.20 from?

Hope you are not going down the postal route again Finn!

Its a rare event when I disagree with Trencher! If you look at the body positions, take away the legs together bit, and you are looking at the sofa ski school. When you look closely at the ski bend, you are looking at Trencher's wonderful ski bend picture.

Trencher, this quality of skiing is not the same as the wedel video you put up to make the same comment. This is a world champion demonstrating skiing through any depth of snow, neatly, in control, avec veuve.

To compound the issue, I'm fairly sure Killy is skiing on 210 Kneissl Black Star. They were practically straight, and pretty stiff,and little in the way of modern ski technology. No carvers, rockers or mods........

Superb video, well found, Old(Young)Andy!

The death of the young boy is a tragedy. I do not see how, under the current and past design of chairlifts, that this kind of accident can be totally avoided, although it should be possible for the incidence to be significantly reduced

I do see irony, that in the current H&S environment, that you may no longer play conkers, but you can sit on a chairlift, and elect, or not be able to, pull down the safety bar.

Trenchers point about a small child not being able to reach the safety bar highlights the lack of local, national and international commonality of safety standards. It seems evident to me, and in my resort it is practice, that when required, (young, old or infirm), the bottom lift man would slow the lift, in order to ensure that the person was safe.

In practise, where there is a predominently adult queue, the chair is way above ground before everyone has aligned their skis, pulled back their sticks, and the bar is lowered.

Further, the worldwide installed capacity is not, in the main, totally safe. Any approach towards maximum safety may imply automation, and that might require power to the chairlift, although mechanical systems do exist.

I have no doubt that technical solutions can be brought to the fore. As a guess, less than 1% of the WIC could be adapted.

Hence, that brings us back to standards,(local to international), of systems, management and training.

Thanks for the early rise tip guys, but I am always there in time for the first lift! :wink:

And so it came to pass.......