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Silver Lining: How Cloud Seeding Works

Nov 7, 2018

A cloud seeding generator.
Credit http://cwcb.state.co.us

The clouds responsible for snow storms can be pretty inefficient, as skiers and riders know well.

 

“A lot of the moisture can just move away from the area where we would like it to snow,” said Dave Kanzer, an engineer with the Colorado River District.

 

Kanzer says there’s a way to increase the productivity of moisture-rich clouds. Cloud seeding involves adding more particles for flakes to form around.

The process starts on the ground. When weather conditions, like winds and temperatures in the clouds, are right, meteorologists turn on generators. These blow a solution of silver iodide into air rising above the mountains, into the clouds. Once in the clouds, the silver iodide crystals can become the seed around which snowflakes grow.

“Anywhere within a 15-mile range, typically, that snow would fall out of the clouds,” Kanzer said.

Kanzer says the science is clear, but the process is not precise. A study conducted in Wyoming shows the conditions are only right in about 30 percent of storms, but when they are, cloud seeding can increase snowfall. That snowpack contributes to the water supply not just in the Roaring Fork Valley, but across the west.

 

“Even if we only increase the water supply by a small fraction, it can have wide ranging benefits,” Kanzer said, including more water in local rivers and more snow on the mountain.

 

The River District wants to see more cloud seeding activities in the Aspen area. On Thursday, the Pitkin County Healthy Rivers Board will hear a proposal from Kanzer about expanding cloud seeding activities. He also has met with City of Aspen water officials and Aspen Skiing Company.

Rich Burkley, vice president of mountain operations for SkiCo, said the company is interested in supporting the River District, but not as a business investment. The small increase in snowfall doesn’t translate to extra powder days for skiers and riders.

“A 10-inch storm going to a 10.5-inch storm, doesn’t really do too much,” Burkley said.

While cloud seeding might not be a boon for powder skiers, Burkley said SkiCo is supportive of any measures that might help the water supply. The company has offered to participate as a site for the generators and to help with manpower to operate them.

The River District is looking for funding from Pitkin County’s Healthy Rivers Board and the City of Aspen; the proposal would then need a permit from the State of Colorado.