Let It Snow: Aerial Cloud Seeding Starts In Wyoming, Proposed In Colorado

Dec 11, 2018

A first-of-its-kind cloud seeding program has started in the mountains of southern Wyoming and could soon be coming to Colorado.

Both states already seed clouds from land-based towers. The practice of spraying silver iodide or other chemicals into winter storm clouds to get them to drop more snow isn’t new, but using aircraft is.

On Nov. 15 Wyoming started using small airplanes to flare silver iodide into snowstorms that roll into the Sierra Madre and Medicine Bow mountains, north of the Colorado-Wyoming border. North Dakota-based Weather Modification Inc. operates the planes. Since starting this fall, WMI has seeded clouds over southern Wyoming four times.

Now, the Jackson County Water Conservancy District wants to expand the practice near the headwaters of the North Platte River in northern Colorado. The district is seeking a permit from the state’s Water Conservation Board to begin aerial seeding during winter storms.

Recent studies have shown cloud seeding can marginally increase snowpack in theory. But a 2018 study from researchers at the University of Wyoming and the University of Colorado said big questions still remain regarding the practice’s effectiveness.

If the state approves the permit, this would be Colorado’s first aerial cloud seeding program.

Wyoming’s program costs the state roughly $425,000, with Cheyenne’s water utility contributing $45,000. The state also oversees cloud seeding towers in the Wind River mountain range, which are partially paid for by water agencies in Arizona, California and Nevada.

Some of Colorado’s cloud seeding operations receive funding from the same states, all in the Colorado River’s lower basin. Earlier this year, water managers in the seven basin states signed a new agreement to continue cloud seeding operations in the southern Rockies, allocating up to $2 million annually. The practice was included as a way to increase water supplies in Drought Contingency Plans being negotiated now, and recently approved by Colorado’s top water authority, the Colorado Water Conservation Board.

Aerial seeding in northern Colorado could begin later this month.

This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.