These are the conditions that ski resorts need to make snow

Colorado’s most committed skiers and snowboarders are already checking the weather forecast, looking for any sign of the first snow. It could be another month before that happens, but ski areas across the state are testing their equipment this week to make sure they’re ready for another busy season.

Loryn Roberson, director of marketing for Loveland Ski Area, says that natural flakes and cold weather aren’t actually necessary for snowmaking crews to lay slopes with a good foundation. Instead, the crews operating the snow guns expect an ideal “wet bulb temperature.”

“It’s a measure of the normal outside temperature plus humidity,” Roberson said.

Although digital monitors are now available, wet-bulb temperature is traditionally measured with special thermometers wrapped in wet tissue. The facility is ventilated as part of a larger system called a psychrometer. As the humidity decreases, the wet bulb temperature becomes lower than the normal air temperature.

The ideal wet bulb temperature for making snow is 27.5 degrees Fahrenheit. This means that if atmospheric humidity is very low, ideal snowmaking conditions can develop at temperatures slightly above 32 degrees Fahrenheit when natural snow would be impossible.

For example:

• Dry temperature of 32 degrees Fahrenheit and 90 percent humidity equals a wet bulb temperature of 30.9 degrees Fahrenheit
• Dry temperature of 35.6 degrees Fahrenheit and 30 percent humidity equals a wet bulb temperature of 27.0 degrees Fahrenheit

However, if the air humidity is high, the two most common types of snow cannons require colder temperatures to operate.

The first type of snow gun compresses air and shoots water into the sky as tiny droplets that freeze and fall to the ground as snow. The second type blows a stream of water with a fan and completes the same process.

“What we want this time of year is those cold temperatures. Also do your cold dances, not your snow dances yet,” Roberson said.

Snowmaking requires approximately 106 gallons to create 11 square feet of snow. It is estimated that a typical ski resort can use millions of gallons of water per year to fill the slopes if natural snow does not fall, but much of it returns to the natural basin as the snow melts. artificial melts.

Hart Van Denburg/CPR News

Energy costs can be high, but many resorts are switching to renewables. Arapahoe Basin, for example, uses solar energy powered by Xcel’s Renewable Connect program to power its snow cannons.

As resorts like Loveland and Arapahoe Basin have tested and approved their equipment for the season, crews will now begin monitoring snow conditions throughout the day.

“(Loveland’s snowmaking crew is) constantly watching the wet bulb temperature. They’re ready to go at any time, and that usually happens in the middle of the night, early in the morning,” Roberson said.

Kevin J. Beaty/Denverite

Due to typical perfect wet-bulb temperature weather, snowplow crews work through the night, arriving to start their shifts at 6 p.m.

“It’s always a very exciting time at the station when we get to these temperatures and we can start blowing snow,” Roberson said.

This year, most resorts along I-70 are aiming for a late October or early November opening date. Bernie Meier, a meteorologist with the National Weather Service in Boulder, said ski areas will likely meet that goal regardless of how late the first snowfall occurs in the high country. Temperatures are forecast to cool over the next 10 days, and a storm system moving in from the northwest will allow us to take advantage of optimal snow conditions in the high country.

“The next system we have going would be a good opportunity to make snow and keep the snow in late October and into November,” he said.

NWS is also predicting a La Niña year, meaning conditions will be drier on the eastern slope with more storms accumulating in the mountains due to the west-to-east wind flow that causes the phenomenon. Regardless of what the warmer temperatures may bring, Roberson says the Loveland Ski Area still anticipates a good season.

“It all depends on Mother Nature, but the 10-day forecast looks like those temperatures will start to drop so we can fire those snow cannons … and create that good base to open our ski slopes,” he said.