Cloud Seeding = Powder Days?

Vail, CO, Jan. 2, 2001–Vail received a foot of snow following a recent storm. Beaver Creek was blanketed with fourteen inches. Aspen got nine inches, while Summit County resorts received anywhere from 6-8 inches. Was it just a fluke storm that smiled upon the Vail Valley, or was the additional snowfall generated by cloud seeding?

“With individual storms, it can have a 10 to 20 percent increase in snowfall,” said Joe Macy, director of governmental affairs for Vail Resorts, who oversees the ski company’s $134,000 cloud seeding program that has been in place for 23 years.

The process burns silver iodide in a Bunsen burner type device that releases the compound into the atmosphere approximately 10 miles upwind of the two resorts. Moisture clings to the silver iodide particles in a process called accretion, and it falls as snow.

“A relatively small percentage of the moisture that passes over falls as additional snow. We are by no means sucking all the moisture out of the clouds,” said Macy.

Although only four Colorado resorts participate in cloud seeding (Telluride, Durango, Vail, and Beaver Creek), many water districts across the country rely on it for increased precipitation.

Nevada taxes fund a program in the Northern Sierra Mountain Range to augment snowpack for agricultural use and to supplement the water supply for the City of Reno.

“We don’t specifically target ski areas with this year’s program,” said Arlen Huggins, a research scientist at the Desert Research Institute in Reno and the cloud seeding director for Nevada. “But in years past, with other programs, over the course of the season some ski areas may notice an increase in snowfall.”

Utah has operated a cloud seeding program since 1974 following the 1973 Utah Cloud Seeding Act. Cloud seeding programs vary from year-to-year around the state, and some have indirectly benefited resorts around Salt Lake City, including Park City Mountain Resort, Snowbird, Alta, and The Canyons.

However, since the programs are partially State funded, it’s up to area water districts to decide when each program needs to be implemented to augment water storage in area reservoirs.

“There is some carry over for the ski areas when these programs are in place,” said Mark Solak of North American Weather Consultants in Salt Lake City, UT. “But the focus of the programs is not the ski areas, it’s water runoff for agricultural use.”