From The Durango Herald (Mary Shinn):
To seed a cloud in Southwest Colorado, employees with Western Weather Consultants light generators that send vaporized silver iodide up to the base of clouds. The silver iodide forms an artificial ice nuclei and attracts supercooled water to form snowflakes.
In an ideal situation, the cloud would release excess water that would otherwise pass over the region, said Eric Hjermstad, co-owner and director of field operations for the company.
“It’s meant to add just a little bit more per storm,” Busto said.
A study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.
During a dry storm or a dry year it’s harder to make a difference, he said.
Seeding during El Niño can help build snowpack to replenish aquifers and help fill reservoirs such as Lake Powell, Hjermstad said.
It’s an investment that is supported by regional water agencies and ski resorts that paid $237,900 this season, according to the Southwestern Water Conservation District. In this area, Western Weather operates about 36 generators from Pagosa Springs to Telluride, Hjermstad said.
This winter, the cloud-seeding supporters are looking to upgrade their efforts through better generators and potentially a radiometer that helps gauge the water and temperature of clouds before seeding, said Ken Curtis, engineer for the Dolores Water Conservancy District.
While he said there’s always skepticism around cloud seeding, the Wyoming study showed that cloud seeding can work if the silver iodide is delivered in the right place under the right conditions.
“We know it works, but you need to do best practices,” Curtis said.
Last week, the Southwest Basin Roundtable granted the group about $55,600 to hire a consultant to help select equipment and the right areas to place it.
The state will review and finalize the grant in the coming months, he said.
The strategic plan to upgrade equipment will likely take two years because there are 12 agencies and companies involved in funding.