Silver bullets: Can cloud seeding ease the drought in the West?

During the summers, Tyler Couch and his crew don’t have a whole lot to do except watch the sky. Sometimes they step outside to scan the pale horizon. Sometimes they huddle with meteorologists at North Dakota’s Bowman Regional Airport to look at radar reports.

When a storm does develop – the right kind of storm, with good size and clouds with enough moisture – Mr. Couch and the other pilots jump into action. They do what most pilots are trained not to do: fly toward a thunderstorm.

They position their aircraft on the fringes of the storm, consult by radio with the radar operators on the ground, and fire off flares burning silver iodide. The hope is that the water in the cloud will adhere to the iodide’s icelike molecular structure and, when it gets heavy enough, fall as precipitation to the parched ground below.

These missions are part of a “cloud seeding” effort – a controversial practice that has been thrust into a brighter spotlight by the grinding drought of the West. Eight U.S. states and parts of Canada undertake similar projects, though mostly in the winter to try to increase their snowpack. Locations in North Dakota, Texas, and Alberta use cloud seeding in the summer to try to wring rain or small, quickly melting hail from often-stingy storms.

A summer of storm chasing

The effort in North Dakota is hotly contested – and banned in some areas – by opponents who object to what they say is an effort to play God, or to the cost of something they say is unproved. Advocates say the science is in; it can increase precipitation marginally and is worth the cost.

Mr. Couch and the three other pilots avoid the public fray. They are young, from the University of North Dakota aviation program. Mr. Couch, at 24, is the oldest and the pilot in command, a veteran of three summers at Bowman.

“We go fly when the weather’s bad. And when it’s nice out, we can just relax and kick back,” says Alex Bestul, from Lester Prairie, Minnesota. “We get the best of both worlds.”

“We like to sit on the hay bales and watch the sunset over the fields,” says Mr. Couch.

But the flying is what they are here for, and flying next to thunderstorms is an exceptional – and sometimes stomach-dropping – experience.

“My first night here – it was probably one of the bigger storms that we had,” recalls Hanna Anderson, an intern who flies co-pilot with Mr. Couch. Both twin-engine planes based in Bowman went aloft.

“It was pretty late,” recalls fellow intern Izzy Adams. Flying in the dark, they had no visual gauge. “We got up there,” Ms. Adams says. “We had enough lightning. Can we see the storm? Can we be close enough to it without being in a threatening spot?” 

“It was quite intimidating,” Ms. Anderson says. “I didn’t go to bed for a while because the adrenaline was still running. It was fun.”

Ms. Adams agrees: “I’ve seen some of the coolest things sitting right next to those storms.”

Jody Fischer, director of flight operations for Weather Modification International, the company that contracts the pilots and planes, says his crews are told to put safety first.

“You have to have a respect for Mother Nature, or she will win,” he says by phone from Fargo. The planes typically flirt with the edges of the storm, and the pilots are taught always to have an escape route and never to get between clouds that could close on them.

Mr. Fisher has been cloud seeding for 21 years, and he says none of his 18 pilots has been hurt. Many of them are itinerant, moving from cloud seeding in one town in the summer to another in the winter.

“Why don’t other counties do it?”

Not everyone is thrilled to see them. Roger Neshem is a farmer who grows grains and row crops in Berthold. He organized the North Dakotans Against Weather Modification campaign, which persuaded voters last year to end the cloud-seeding program in Ward County. 

Mr. Neshem, who has taken his campaign to other counties, mainly argues that the program does not work – and if it does, it takes water away from farmers downwind of the effort.

“It’s property rights,” he says by phone. “You do what you do on your side of the fence, but don’t start to affect what falls on my property.” And, he notes, “If this works so well, why don’t other counties do it?”

Darin Langerud, who runs the North Dakota Cloud Modification Project, says by phone from Bismarck that the program, run by the state for 46 years, has produced results. “Numbers fall between the 5% to 10% range in terms of increasing rainfall. And crop damage from hail reduced 45%.”

When clouds seem to be building hail, the pilots attempt to urge the hail to form quicker and smaller, thus reducing serious damage. “I can see it with my own eyes,” says Bowman rancher Wayne Mrnak. “My crop insurance has gone down on hail damage. When I was a kid, we would lose all or part of our crop to hail every year.” But Mr. Mrnak, who sits on the local cloud seeding board and helped defeat a proposal in Bowman County to end the program, admits the ability of the program to produce more rain is “a bit iffy.”

Indeed, Mr. Neshem argues that the studies showing the success of cloud seeding are mostly on winter seeding. The two sides offer dueling studies.

“The only way we would be doing this, is if we were sure it’s successful,” contends Julie Gondzar, project manager of cloud seeding for the Water Development Office in Cheyenne, Wyoming. Her state, like most of the others, does only wintertime cloud seeding.

Sarah Tessendorf, a project scientist at the National Center for Atmospheric Research in Boulder, Colorado, helped carry out influential wintertime experiments in Idaho. She says the research, dubbed the Snowie study, “unambiguously” showed an increase in snowfall from cloud seeding. But she says there is less proof to support summertime cloud seeding, which deals with fast-moving, fast-rising “popcorn convection” clouds, while snow clouds are low and slow to develop.

“The scientists are divided,” says Adnan Akyüz, North Dakota’s climatologist. “Some are true believers, and some think seeding doesn’t add anything. I am right in the middle.”

Whatever the benefits of cloud seeding, there is agreement on one point: Without clouds, there can be no seeding. “You can’t seed your way out of a drought,” says Mr. Akyüz. Unless the sky offers up clouds, there is nothing to seed.

Which leaves Mr. Couch and the other pilots sitting on haystacks scanning the blank horizon. Waiting for the clouds.