• Image about Errol Kerr
Errol Kerr, the sole member of the Jamaican Olympic ski team, trains on man-made snow in Nevada.

When the white, fluffy stuff doesn't fall from the sky, ski resorts give Mother Nature a helping hand.

IT’S JUST EARLY NOVEMBER, but Errol Kerr is already thinking snow. The sole member of the Jamaican Olympic ski team, Kerr looks at the temperature and humidity gauges by the front door of his American-born mother’s home in Lake Tahoe, Nev. The front yard, with his homemade ski-cross starting ramp, is as bare of snow as the mountains around him, and he knows his Austrian and Swiss competitors are already training in the glaciers of the Alps. He heads to his garage and grabs his welding mask, some iron piping and hoses. It’s time to make snow. After 12 hours of his soldering and spraying, an SUV-size mound of snow is piled on the lawn. His season has begun.

  • Image about Errol Kerr
At the same time, a few miles up the road at the Northstar-at-Tahoe resort, director of operations John Loomis is getting ready for the start of his own season. His crew preps and launches computer-controlled snowmaking fan guns, each costing $30,000. With various types of snowmaking guns mounted to hundreds of snow towers covering 50 percent of approximately 520 acres of developed trails, the snowmaking system is a massive and vital component to the survival of this mountain resort — and to your winter vacation.

From the individual athlete to the largest megaresort, snowmaking is an essential and bottom-line aspect of any ski season. No snow, or not enough snow, means fewer skiers. And fewer skiers means less money.

Kerr’s homemade system reduces snowmaking to the basics: a hose with water, a hose with pressurized air, a couple of nozzles and a post to hang them on. The nozzle from one hose sprays a fine mist of water across the high-speed jet of compressed air coming from the second nozzle. On a cold day, the combined jets form small ice ­crystals that float into the larger mist of water vapor and chilled air, then fall to the ground as snow. With everyday materials sourced from a local hardware store, Kerr can create an 8-foot-tall pile of snow in his front yard overnight.

Knowing when to make snow is as important as knowing how to make it. The key indicator is the wet-bulb temperature, a figure indexing humidity and air temperature. The measure is derived from the technique of putting a wet cloth over a thermometer and measuring the temperature on the gauge once blown air dries out the cloth. It’s similar to the wind chill index — what you’d feel if your skin was wet and the wind was blowing. For snowmaking, the wet-bulb temperature means that you can actually produce snow at above 32 degrees if the humidity is low enough.

While the same principles of science apply, comparing Kerr’s homemade rig with a resort snowmaking system would be, as he says, “like comparing a paper airplane with a 777.” Consider California’s ­appropriately named Mammoth Mountain and its snowmaking facilities, which cover more than 800 acres and include 47 miles of underground piping connected to a 25-million-gallon water reservoir. About two hours north of Vancouver, Whistler/Blackcomb’s combined snowmaking system has 270 snow guns, multiple power plants and ­helicopter-placed towers — an infrastructure valued at more than $50 million. In Utah, the Deer Valley ski resort turned 200 million gallons of water into snow last season alone.

Resort snowmaking has not only the scale but also the sophistication to awe visitors. Computer programs alter water and airflow by the minute to adjust to changing temperature and humidity conditions. Snow-jet fans rotate to create an even covering over slopes, ensuring a proper distribution on a ski run. They can cover acres of slopes with a foot of snow overnight, while power-adjustment features manage their energy consumption. Some spray a wetter, firm base layer of snow on the ground before topping it off with dry, fluffy flakes for happier skiers, almost like a birthday cake with frosting. Gone are the days of artificial snow like shaved ice; Whistler Mountain says its ski instructors actually request that artificial snow be sprayed on their favorite runs.