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Snow-making at ski areas is critical, and here’s why

Climate change is affecting two critical ingredients of snowmaking: cold temperatures and water

Snow-making at Arapahoe Basin Ski Area in Dillon, Colo. (Bill LeClair)

It’s 4:15 a.m. and 23 degrees under a clear sky. While most are cozy in bed, there is a committed crew on the mountain side of a ski area preparing trails for a great day of skiing and riding. This is the call of duty for a snowmaker.

“I look in the mirror and say, ‘Why do I do this?’" joked Bill LeClair, snow-making manager at Arapahoe Basin Ski Area in Dillon, Colo. “It kind of gets stuck in your blood.”

What started as “just a job” on an 11-p.m.-to-7 a.m. shift for LeClair turned into a career spanning more than 35 years in snow-making operations at various ski areas from New England to the Rocky Mountains.

“It takes a different breed to make snow. Snowmakers are proud of their job,” LeClair said. Arapahoe Basin is routinely one of the first ski areas to open each year in the West, largely thanks to both elevation and its snow-making efforts.

Snow-making has been around for decades and has become an important addition to mountain operations at many resorts. It is part of the routine at roughly 87 percent of ski resorts nationwide, most common in the Mid-Atlantic, Midwest and Northeast.

Snow-makers, like LeClair, are among more than half a million jobs supported by the roughly $55 billion ski industry economy, according to 2020 data from the National Ski Areas Association (NSAA).

“Snow-making allows ski areas to put down a durable, consistent snow surface. It’s kind of like an insurance policy against a low snow year or slow start to the season,” said Adrienne Saia Isaac, director of marketing and communications with the NSAA.

Veterans Day is typically the unofficial kick-start to the ski season for some of the early-to-open ski resorts. More traditionally, many ski areas target Thanksgiving to Easter to offer skiing to the public.

But the 2021-2022 ski season — given widespread drought and a mild fall — had a slow start in certain parts of the country. November began with just near 3 percent snow cover — the third-lowest snow cover extent on record for the contiguous United States.

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While a select number of ski resorts in California opened early because of unusually heavy snowstorms, other regions were void of snow for historically long times. Denver didn’t see measurable snow until near the end of November, matching a record for the latest snowfall of the season. In the Mid-Atlantic, many ski resorts struggled to open until they received their first dose of heavy snow and cold-enough temperatures to make snow in January.

The delays could get worse as temperatures continue to rise, too. Winter is the fastest-warming season in the country, most rapidly warming in the Northeast and the Great Lakes region. Climate change will decrease natural snow in higher elevations, making snow-making more critical for the ski resort industry.

Snow may vanish for years at a time in Mountain West with climate warming

On that same note, climate change could also make snow-making more difficult as the cold temperatures necessary for the practice become more scarce, especially at lower elevations.

Snow-making explained

Much like meteorologists, snow-makers are always watching the weather. Weather is the main factor to successful snow creation — humanmade or natural. Besides the equipment, there are two things ski areas need to make snow: cold and water.

“If you look at it, you can get really nerdy about how you make snow, all the way down to the heat exchange,” LeClair said.

For the human variety of snow-making, the key variable is the wet bulb temperature. The wet bulb temperature is a measure of both how cold it is and the amount of moisture in the air. Basically, it indicates the lowest temperature to which the air can cool through the evaporation of water. The drier the air, the more the temperature can cool and the lower the wet bulb temperature.

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At most ski areas, a wet bulb temperature of 26 to 28 degrees or lower is needed to make snow.

“Folks say you can make snow with a wet bulb in the 20s, but I prefer in the teens,” LeClair said. “The lower the humidity when making snow, you just get a better product.”

The artificial snow-making process is similar to that found in nature. In nature, snowflakes are created when extremely cold water freezes onto a small nuclei, such as dust or dirt. Humans make snow by blasting tiny water droplets into the air to serve as the nuclei, allowing moisture to freeze on contact.

“We’re making an ice ball basically. We’re not making a stellar crystal like you see on a Christmas card. But when you give it more hang time, it’s a better quality of snow,” LeClair said.

Hang time refers to the amount of time a snow particle stays in the air after it is blasted from a snow-making machine, either by fans or compressed air, then slowly falls to the trails.

In a new twist on an old tactic, ski resorts are using snow machines to fight fires

How climate change affects snow-making

Snow-making can help ski areas lay a base before frequent snow and consistent cold temperatures settle in for the winter. However, as fall and winter climates trend warmer, snow-making is not the ultimate fix to secure the future of winter recreation. You still need cold temperatures, which have also been slowly declining across the country.

Enter winter, the fastest warming season

“Snow-making allows ski areas to put down a durable, consistent snow surface,” Isaac said. “But it’s not a silver bullet for climate change — you can’t make snow without cold temperatures and water.”

Additionally, snow-making operations can use high amounts of energy, particularly older and more traditional operations. These days, many ski areas have joined climate and efficiency commitments, adopting more sustainable operations and practices, including investing in energy-efficient equipment and adding renewable energy resources such as wind and solar to the mix. Initiatives like Protect Our Winters and NSAA’s Sustainable Slopes encourage more efficient and sustainable ski area operations, which many have adopted.

Drought can also affect the overall season operations, limiting crucial water resources that feed snow-making. Droughts are projected to become more intense in a warming climate. Since the start of this winter, about 90 percent of the West has endured drought conditions, according to the U.S. Drought Monitor.

Many ski areas, particularly in the West, are mandated to follow local guidance on water use, which can have stricter limitations in years of low precipitation.

“Offseason precipitation definitely matters. Water is the most important resource for snow-making, and for so many uses. Drought can affect diversion rates, and contributes to increased threat of wildfires in the summer and fall,” Isaac said. She said about 85 percent of humanmade snow returns to the watershed.

Drought conditions improve in U.S. West, but more snow is needed

At the end of the day, LeClair said snow quality is really what all ski areas are after to make the experience truly enjoyable for guests and keep them coming back for more, season after season. And the efforts continue year-round to provide this experience for consumers.

“There’s no down time in snow-making. The summer is just as important as winter. It’s not like we just turn the light switch off, and we’re done,” LeClair said. “No, when we turn the light switch off, we turn it right back on and start getting ready for next winter.”

Kasha Patel contributed to this report.