Let it snow! Let it snow! Let it snow! That's what you may be singing when Old Man Winter rolls through. But as you already know, Mother Nature doesn't always cooperate.
For snow to fall, the right weather conditions have to exist. That means there must be moisture in the air, especially high up in the sky where it can fall to the ground as precipitation. The temperature also has to be just cold enough to make the moisture freeze into snowflakes rather than falling as raindrops.
Sometimes, it might be below freezing at ground level where you are, yet you get rained upon. What's up with that? Even when it's cold at ground level, it might be much warmer up higher in the atmosphere, so moisture falls as rain rather than snow.
At other times, it might be above freezing at ground level, but you look out your window to discover beautiful snowflakes falling. That means it's probably much colder up high in the atmosphere.
The people who run ski resorts know very well how fickle Mother Nature can be. They try to provide the very best skiing conditions for visitors for as long as possible, and that requires one thing: lots and lots of snow!
Unfortunately, the weather conditions aren't always right for snow. That fact led some clever guys to invent a way to make snow with a machine way back in 1950. While many people call this manmade snow “artificial," it's actually made in much the same way that Mother Nature makes “real" snow.
Snow machines use water and compressed air to shoot tiny water droplets into the air. As these water droplets hit the cold air, they form ice crystals that fall to the ground as snow. So even if there's not enough moisture in the air to snow, machines can make it snow on command!
However, it still has to be cold enough for the water droplets to crystallize into snowflakes. Machines also have to duplicate the natural process of snow formation as closely as possible. When real snow falls, the crystallization process is aided by dust and other small particles in the air. Modern snow machines spray these same types of particles into the air, along with the water droplets, to help snow crystals form.
Of course, you can still make something close to snow even if temperatures aren't cold enough. In really warm areas, ice is sometimes chopped into tiny pieces and blown into the air to simulate snow.
Modern ski slopes often feature manmade snowmaking machines that cost millions of dollars and rely upon miles of underground water and compressed-air pipes. They can be used year-round to supplement natural snowfall, so that a more consistent snow level can be maintained.
Unfortunately, skiing professionals point out that manmade snow, while made in a similar way to natural snow, is still different from natural snow. They claim manmade snow tends to pack together more tightly and thus becomes icy more quickly. This can be good for ski racers, but those who prefer to ski in fresh powder say it's just not the same!
Making manmade snow can also be very expensive — both in terms of money and resources needed. To cover one acre of ground one foot deep in snow, it can take up to 200,000 gallons of water and cost over $2,000!