Weather It Matters: Snowmaking through wild winter weather

CASS COUNTY, Mich. -- It’s a smooth ride down the slopes at Swiss Valley Ski and Snowboard Area in Michigan. To get all the snow it takes to make the mountain sparkle, however, Mother Nature sometimes needs some more firepower.  

Daniel Lewis oversees snowmaking operations at Swiss Valley.  

“On a busy night, I can have more than 60 guns running,” Lewis said.  

While all of this equipment might look complicated, the science behind the sudden snow is simple.  

“It's making a really tiny cloud and mimicking the natural process that makes snowflakes,” Lewis explained. 

Lewis says snowmakers use compressed air to flash freeze water droplets, giving snowflakes something to form around. However, these flakes need time to grow. Swiss Valley uses equipment with 30-foot sticks and giant fans to fill the slopes with feet of snow.  

Lewis and his team can’t just conjure snow in any weather conditions, though. Snowmakers have to pay attention to the air temperature and humidity before firing up their fleet. Lewis uses a combination of the two, known as wet bulb temperature, to test the snowmaking environment.   

“It takes into account the evaporative potential of the air,” Lewis explained, “because a big part of freezing snowflakes quickly is having a small amount of water evaporate, and that takes heat with it.”  

That means some of the worst weather to make snow in is actually when it’s naturally snowing.  

“If it's 28 degrees ambient, 100 percent humidity and natural snow, that's actually a very challenging set of conditions to make more snow,” Lewis described. “A lot of times, we'll let nature take your course and give our skiers some great conditions.”  

Many times, however, Mother Nature doesn’t want to cooperate with winter sports fans’ best wishes. Rainy nights and huge warmups wiped out Michiana's snowpack early this winter. But the snow at Swiss Valley stayed put, largely because of how the manmade snowpack acts like a sponge, letting water through.  

“The top layer might get a little sugary and the bottom of the snowpack, and the last inch or three might get icy and muddy, but we've got three feet, four feet of good snow stored between,” Lewis said.  

Meaning that the slopes will stay ready, no matter what season shows up that day.