‘Cloud seeding’ offers water generation opportunity in Arizona, with some caveats

PHOENIX — A scientific process of triggering rain or snow known as “cloud seeding” offers tantalizing possibilities for water creation, especially in areas like drought-stricken Arizona.

Orestes Morfin with Central Arizona Project said the actual process of cloud seeding is fairly simple.

“Cloud seeding… stimulates the generation of ice crystals or precipitation,” he explained. “When you introduce what is called a ‘nucleating agent,’ it just gives a little kickstart for the water in that cloud to start coalescing.”

The most commonly used nucleating agent is silver iodide, and it and other compounds like it can be utilized in a variety of ways.

“There’s the aircraft method, where you fly through the clouds and disperse your nucleating agent,” Morfin said. “There are also ground-based generators.”

However, there’s a caveat: for cloud seeding to be most effective, there’s an element of chance involved.

“There are some storms that just don’t lend themselves well to generating enough snow if you seed them,” Morfin explained. “Predicting the suitability of a storm season… that’s sort of hard to assess.”

Morfin added that many specific weather conditions need to be accounted for.

“[Conditions] including air temperature, the cloud moisture, the wind speed, the direction,” he said. “It is absolutely impossible to know before a winter season how often those conditions will occur.”

That reality has guided the way CAP thinks about cloud seeding. Instead of relying on water from cloud seeding, they instead aim to use the technique whenever possible to boost existing water supplies.

Currently, Morfin said CAP is focused on funding cloud seeding projects upstream to boost snowpack and augment the Colorado river.

However, he added that technological development will continue to make cloud seeding more viable as a potential source of water to bolster our supplies.

“There have been some recent events in particle modeling, using historical weather to determine the most ideal places, [and] some pioneering advancements in the use of radar, ice sensors and weather stations to determine the appropriate time to seed,” Morfin said. “The focus now is on predictability.”