Q: How do snowmakers used at ski resorts work?

A: Most Pennsylvania ski resorts keep a nearly permanent covering of snow from November to March, but how do they do it?

The answer is snowmaking machines, a nearly indispensable technology that is able to create artificial snow to fill the gaps in snow provided by Mother Nature.

Andy Himes, general manager of Blue Knob All Seasons Resort, explained that there are three main types of snowmakers, and each works a little differently.

The first type mixes large amounts of air and water, then atomizes the water and sends it out in small particles, which become snow.

A second type of snowmaker uses a very fine tip to atomize water under very high pressure and shoot it out into the air.

The third type is an airless gun that looks like a large turbine and uses a fan to atomize the water and throw the snow out away from the machine.

While airless guns are more expensive to buy and maintain, they are less expensive to supply with air and water, Himes said. The second type is more efficient than the airless guns but is not at all mobile. The third type uses large quantities of air but is mobile and much more convenient.

While different, the relative principle behind these machines is the same, said Tom Matalavage, mountain manager of Tussey Mountain Winter Resort. Air and water are introduced together and allowed to freeze as they are shot into the air and fall to the ground.

At Tussey Mountain, one set of lines sends water up the mountain while one set of lines sends the air uphill.

Himes said the most ideal conditions for making snow are temperatures between zero and 12 degrees Fahrenheit with a very low dewpoint. The quality of snow made is completely dependent on the temperature.

The artificial snow made by these machines is much denser than real snow and is often used as a base, because it takes longer to compress and form ice, said Himes.

Matalavage said he uses wetter snow on high-traffic areas of the slopes, including the top of the mountain where the lift lets skiers and snowboarders off, while the drier snow is used on the actual mountain, in the areas where customers ski and snowboard.

While the amount of snow made year to year varies, this year snow was made primarily at the beginning of the season, and more was added in late December into early January.

The basic misconception regarding snowmakers is that snow comes out of them, while in reality it is only water, Matalavage said.

These machines need to have temperatures well below freezing to operate at peak efficiency.

"When the snow starts melting, people ask, 'Why aren't you making snow?' " he said. "It needs to be cold enough for the water to freeze, or all we have is a real expensive irrigation system."

-- By Kelly Sitch