Flying near a fast-forming storm in North Dakota. (Photo: Shawn/flickr)

The storm is fierce and glowing turquoise, and Steffany Royal is waiting for it at the border of Montana and North Dakota circling 7,000 feet high in a Piper Seneca—a tiny airplane that looks a bit like a large metal mosquito.

Back on the ground, Wayne Mrnak, a sixth generation North Dakota farmer, fearfully watches the sky. The strange tropical ocean-colored clouds indicate light reflecting off bits of ice in the storm’s core. This means hail, a potential death sentence for farmers like Mrnak, whose 6,000 acres of wheat, barley, corn and sunflower lie striped across picturesque rolling plains in the state’s southwestern corner, near a region of rugged hills called the Badlands. “We’ve had hailstorms here where there is nothing left,” says Mrnak. “It will take the crop completely down—down to the ground.” In mere minutes, millions of dollars of plant material, including the delicate kernels, which aid in reproduction, can be smashed to bits. It’s a crop’s version of death by stoning.

The job of pilots like Royal is to fly directly at monstrous thunderstorms—something most pilots diligently avoid, given that the turbulent airflow in these storms occasionally brings down commercial jetliners—and discharge chemicals into a particular part of the cloud, a technique called “cloud seeding” intended to suppress the storm’s ability to produce hail.

But on this late June day, the storm racing across the prairie is outmaneuvering the 22-year-old Texan pilot. “I started approaching from the east, which is the front of the storm and should have been kind of calm,” says Royal, “but it was so turbulent that my seatbelt wouldn’t even stay fastened.” 

So she turns back, and for the moment, the lives of Mrnak’s crops hang in the balance.

The view from Steffany Royal’s Piper Seneca of a gathering singlecell thunderstorm. It produced hail the size of baseballs. (Photo: Steffany Royal)

Florida has the sun, Buffalo gets snow, the Gulf Coast faces hurricanes and southern California tackles a potpourri of earthquakes, fires, droughts and mudslides. North Dakota is hail country. The most regular and severe hail storms occur in a north-south stripe across the middle of the continent, extending from the panhandles of Texas and Oklahoma up through eastern Colorado, Wyoming and Montana, the western Dakotas, and on into the Canadian province of Alberta.

In late spring and summer, winds blowing east over the Rocky Mountains tap moisture streaming north from the Gulf of Mexico to create massive thunderstorms on the Great Plains that occasionally produce tornados and frequently produce hail. Unfortunately, the hail belt also happens to be the farm belt. In North Dakota, about 90 percent of the land is covered by crops or used for cattle ranching, meaning if it is hailing, someone’s plants are probably getting pelted, if not completely crushed. 

A newspaper from 1966 reporting on hail toradoes

A North Dakota newspaper from 1966 reporting on hail tornadoes. (Photo: Tim Evanson/flickr)

For those who only occasionally experience short bouts of hail, the idea of a hail belt might not seem that bad. But hail in this region can tear the shingles off roofs, pock cars so bad they look as if they were sprayed from above with a machine gun, pile so deep that snow plows need to be called out—a 1980 storm in Orient, Iowa left hail drifts six feet high—rip leaves and even branches and bark off trees. Death comes with hail: the ice chunks bludgeon to death birds, cows, and people. The last known human fatality in the U.S. was in 2000, when a 19-year-old Texas man was struck by a softball-sized hailstone estimated to be traveling at 100 miles per hour. Hail causes around $1 billion in crop and property damage annually. One safeguard against the ice is hail insurance, which is now common across the nation, but in the hail belt there is a more proactive means of protection: cloud seeding pilots like Steffany Royal.

Royal’s employer is Weather Modification Inc., or WMI, the world’s largest company of its kind, and one of the oldest, started by a group of Bowman, North Dakota, wheat farmers in 1961. But WMI Vice President of Meteorology Bruce Boe, speaking from global headquarters, a lackluster office building near the runways at Hector International Airport, in Fargo, North Dakota, is quick to critique the phrase that defines the industry.

“To call what we do ‘weather modification’ is misleading,” says Boe, a sturdy man with a crew cut and a master’s degree in atmospheric science. “We are not modifying weather so much as modifying clouds.”

The history of weather modification was, until fairly recently, littered with failures.

Hans Ahlness, WMI Vice President of Operations (at left), with Bruce Boe, Vice President of Meteorology, in front of one of their air craft on the runway, at the headquarters of Weather Modification Incorporated, at Hector International Airport, in Fargo, North Dakota. (Photo: Justin Nobel)

In the 1st century A.D., the Greek historian Plutarch hypothesized that rain followed military battles. This theory died hard; Napoleon believed volleys of gunfire could bring rain, as did the U.S. Civil War brigadier general, Joshua Lawrence Chamberlain. In the late 1800s, the U.S. Congress bankrolled a project to initiate rain over West Texas using an elaborate system of kites and homemade mortars—despite somewhat promising early results, the effort was eventually deemed a disaster. 

War played a role in WMI’s genesis too. After World War II, and the Korean War, many North Dakota-bred fighter pilots returned to the farm, only to have their crops ruined by a succession of hail storms. As North Dakota farmers were pioneering ways to halt hail, the U.S. government, spurred into action by the Soviets—who were claiming great success using rockets to seed clouds—was initiating Project Skywater. From mountaintop stations across the Rockies government scientists were spraying clouds with silver iodide. “We had just come out of World War II and felt we were on top of world,” says Boe. “We thought we could do anything, we could be Adam, and humanity had no bounds on what science could do.”

During the 1960s and 1970s the project, monitored by the National Science Foundation and the National Center for Atmospheric Research, continued in eastern Colorado as the National Hail Research Experiment. But after several summers scientists concluded there was no evidence their work was enhancing rain or reducing hail and killed the project, which joined a long list of failed government weather mod schemes. 

A Cessna 340 undergoes repairs in a hanger at the headquarters of Weather Modification Incorporated, in Fargo, North Dakota. (Photo: Justin Nobel)

Despite Boe’s aversion to the idea of weather modification, the term favored by the industry is weather mod, and few people realize just how much the process may be affecting their lives. If you fly into Salt Lake City in winter, a weather mod company may have helped clear the fog that allowed your plane to land. If you water ski on Lake Mead in summer, weather mod may have helped to prime the clouds that poured the rain that meandered into the rivers to fill the lake. And if you are in Philadelphia or New York City and dare eat a peach, or plum or apricot or nectarine, it may well have come from California’s Central Valley, irrigated by water channeled from snowmelt on the Sierra Nevada mountain range, above which weather mod planes regularly fly, aiming to enhance snowfall.

There is no firm data on weather mod’s economic footprint, but there are about a dozen weather mod companies operating in the U.S., and the industry as a whole is likely worth somewhere in the tens of millions of dollars—WMI is mum about costs, but larger projects probably cost several hundred thousand dollars, and smaller ones considerably less.

But weather mod goes far beyond the borders of North America. WMI pilots have flown airplanes into thunderstorms on six continents. The company has worked to suppress hail in Argentina and Alberta, build snowpack in California and Wyoming, and enhance rain in Saudi Arabia, Turkey, Mexico, India, Morocco, and Mali. Present projects are in North Dakota, California, Idaho, Wyoming, Alberta and India. Typically, the company’s contact is with government agencies or militaries, but not always. An unusual request came from lush Papua New Guinea, where a copper mine wanted WMI to help boost rainfall during the dry season in order to keep a steady flow in rivers that run the hydroelectric dams that power the mine.

WMI planes are equipped with silver iodide burners on both wings, each capable of running for about two to two and a half hours. ”People think of storms as something fixed, but that is not the case at all,” says 22-year-old WMI pilot Steffany Royal. “They are like living organisms, and are changing constantly. The average cell only lasts 15-20 minutes.” (Photo: Justin Nobel)

“This is a rainforest that gets 10 meters of rain a year and has moths as big as your hand,” recalls Boe, who has been working in the industry for over 40 years. (His company is still writing the project’s proposal.)

Occasionally, a local entrepreneur reaches out to WMI, as has happened in Iran, Iraq, Afghanistan and Syria, but none of these projects made it off the ground. “With Syria the dialogue never got that far,” says Boe. “With all their civil war problems and everything else, I would not want to be going there right now.”

It is worth noting that individual citizens of some of the world’s most volatile regions have asked WMI for cloud seeding services. A growing body of research addresses the idea that many wars and conflicts are stoked by environmental problems, which are often underlain by weather problems. Increasing drought across north-central Africa has ruined crops, starved the populace and is thought to have enabled Al Qaeda in the Islamic Maghreb’s invasion of northern Mali in 2012. A paper published earlier this year in the Proceedings of the National Academy of Sciences journal stated that drought in Syria between 2007 and 2010 was the worst since instrumental record-keeping began, and caused widespread crop failure, mass migration and helped spark the Syrian conflict.

A storm seen from the runway at Bowman Regional Airport in Bowman, ND.  (Photo: Steffany Royal)

If superimposing locations of drought and war on the world map isn’t convincing enough, economists have crunched the numbers. “In sub-Saharan Africa specifically,” reads a 2014 Brookings Institution report on conflict and agriculture, “a proportional change in rainfall (from the previous year) of five percent increases the likelihood of a civil war the following year by 50 percent.”

If drought equals poverty equals war and disaster, every single raindrop alleviates the situation. And, one imagines, in places where hail is common, every single crop-crushing hailstone worsens it. Which seems to make a good case for cloud seeding: rein in the weather and you can literally end wars and save the world. Of course, the reverse seems to be happening. The weather appears to be on an unprecedented climate change-induced rampage, which involves stronger hurricanes and typhoons, and more frequent floods, droughts and wildfires. In response, a sort of weather mod on steroids has been advocated: geoengineering. It differs from weather mod in that it posits that not only can the weather be modified on a local level, but with the right infusion of chemicals or mirrors or god knows what else, the entire climate system can be readjusted. But Bruce Boe’s plans are not so grandiose.

“What we are really doing,” he says, speaking about rainfall enhancement over a bacon cheeseburger at a popular Fargo lunch spot, “is making clouds a little more efficient.” Or, in the case of hail, making them a little less deadly.

A rainbow appears over North Dakota's badlands.

A rainbow appears over North Dakota’s badlands. (Photo: Kirsten/flickr)

Rain falls regularly from clouds onto our umbrellas and faces, yet rarely do we contemplate its dramatic journey. To do so, first erase your mental image of water. It is nothing but a loose-knit collection of H2O molecules, which we call a liquid. Ice is a tightly-packed collection of H2O molecules, a solid, and a bunch of H2O molecules on their own constitutes water vapor, a gas. Oceans, lakes, swamps and even vegetation-covered landscapes like forests and fields contain copious amounts of liquid water, which sunshine helps evaporate into the air as water vapor. Sun-heated air and water vapor near the earth’s surface float up into the sky and cool while rising, the air condenses, and the H2O molecules are drawn closer together. 

But water vapor cannot become liquid water without the help of tiny wind-blown particles in the atmosphere such as dust, soot and salt. These particles serve as collection points, drawing water vapor molecules into a glob of water called a cloud droplet, the beginnings of a cloud. Still, cloud droplets are small, typically five to 10 microns across, and one must collide with a million other cloud droplets before becoming large enough to form the thing we call a raindrop.

In 1946, the atmospheric scientist Bernard Vonnegut, novelist Kurt’s older brother, discovered that when compounds like silver iodide are dropped into clouds they act like the dust, soot or salt and enable water vapor to cling to them, jumpstarting the raindrop formation process. Rain can’t be created from nothing, but clouds can be made more efficient at producing it, or so says the science of cloud seeding.

A diagram about how cloud seeding works.

A diagram on how cloud seeding works. (Photo: Smcnab386/WikiCommons CC BY-SA 3.0)

Ice crystals are formed in basically the same way as rain. Like the change from vapor to liquid, water is sluggish in its transition to ice, but again, particles in the atmosphere help draw liquid water in and lock it into place to become solid. The thinking behind hail suppression is that spraying silver iodide into a developing thunderhead—the birthplace of all hailstones—spawns an army of smaller ice particles that uses up the available cloud water, thus preventing the larger crop-crushing hailstones from forming. 

WMI planes are equipped with silver iodide burners on both wings, each capable of running for about two to two and a half hours. Silver iodide flares sit in racks under the wings. Upon release, they last anywhere from around 30 seconds to two minutes and deliver a concentrated dose to the would-be ice particles. When suppressing hail, the goal for pilots is to release the silver iodide directly into the storm’s updraft, which is the vertically-oriented region of warm moist air rising up off the ground that fuels thunderstorms. Hail forms when cloud droplets get shot up the updraft of a storm into the taller parts of the cloud and freeze. The stronger the updraft, the longer the hailstone can stay suspended in the storm, the more liquid water it can freeze onto its surface, the bigger the hailstone can become. 

Replicas of two of the largest known hailstones ever to fall from the sky in the United States. The 1.937 pound, 8-inch diameter monster hail stone at left landed in Vivian, South Dakota during a summer storm in 2010. The other hail stone fell in Coffeyville, Kansas in 1970. (Photo: Justin Nobel)

Resting on a desk in Darin Langerud’s office is a jagged hunk of plaster that looks like a craft project made by a troubled kindergartener, but is actually a replica of the largest known hailstone ever to fall from the sky in the United States, a 1.937 pound monster that landed in Vivian, South Dakota, during a summer storm in 2010. Langerud is the Director of the North Dakota Atmospheric Resource Board, and runs the state’s cloud modification project. For over 50 years, the group has employed WMI pilots to fly late spring and summer hail suppression flights over counties in the western part of the state, including Bowman County, where Wayne Mrnak’s farm is located. 

Using a framed photograph of a billowing thunderhead, Langerud illustrates the anatomy of a classic thunderstorm. The mature section towers 40,000 feet or more into the sky. Cloud seeding pilots don’t go here because updrafts are too strong—sometimes more than 100 miles per hour—and these storms are usually already producing hail. Instead, pilots aim their silver iodide burners and flares at the juvenile part of the storm, where cottony cumulus clouds are swiftly blossoming and there are more moderate updrafts. An updraft is like an invisible elevator of hot air that rises off the earth’s surface and rushes energy into the heart of the storm. Releasing silver iodide here is a clever ploy to use the developing storm’s own engine to weaken it. “We try to influence the small clouds,” says Langerud, “so we can teach them how to behave when they get older.”

“Most pilots don’t ever get to do anything like this,” says 26-year-old WMI pilot Vadim Alekseyev. “It looks good on the resume.” (Photo: Justin Nobel)

Langerud is keen to drive to Bowman and check on his pilots. Bismarck is in the middle of the state, and driving west on Interstate 94 a steady light rain pings the windshield. The endlessly rolling prairie is cloaked under low gray clouds. This precipitation is not coming from a thunderstorm, but a broad belt of clouds covering the central part of North Dakota, a pattern Langerud says is unusual for this time of year. And what of weather mod’s future, I ask him, as we approach Bowman, entering a misty landscape of lofty buttes.

“There has been some discussion that in the future they are going to be using drones, and they may be,” he says, “but I think that’s a ways down the line.” Later on, he explains further: icing conditions make drone operations “problematic.” He’s not aware of any unmanned planes in current use. 

The past of weather modification, though, stretches into even more fascinating places than its future. Along the banks of the Missouri River, in North Dakota, once nested a pair of eagles called the Thunder Birds, by the local Native American tribes of the region—namely the Mandan, the Arikara and the Hidatsa. The eagle had a wingspan a mile wide, and bolts of lightning flashed from the wings. The Thunder Birds seemed invincible, but every year a tremendous serpent snatched their eggs. One year two young Shoshoni warriors decided to guard the nest. When the snake appeared, they fired arrows into its throat, killing the beast. In return, the Thunder Birds granted the braves the power to make rain. When the men died the power lived on in their skulls, which were severed from their bodies, wrapped in buffalo hide and kept in a bundle by the tribe. In 1907, commissioned by a rich New York City man who wanted to put the treasure in a museum, an anthropologist bought the bundle for about $100. At some point these sacred rain-generating bones may have made it back to the American Indians, but no one seems to know for certain.

Flying towards a cell thunderstorm. (Photo: Steffany Royal)

Steffany Royal has turned her Piper Seneca around to flee the storm and its turbulence, but already racing toward the cell is colleague Vadim Alekseyev, 26, in a Cessna 340. He approaches from the south and finds a clear, less-turbulent path to the edge of the storm. Here he spots what he’s looking for, a shelf, or fluffy layer of clouds just below the base of the thunderhead that indicates an updraft. Alekseyev turns on his burners. And lo and behold, Royal is back. Repositioning, she follows Alekseyev’s route into the storm, making sure to keep her Piper Seneca about several miles distant from his Cessna so the two don’t collide, and switches on her burners. Alekseyev also unloads two burn-in-place flares, an extra bump of silver iodide.

Although it is impossible to instantaneously assess if the dosage has any effect, the storm is weakening, and within minutes it vanishes altogether. “It was amazing,” says Royal. “Once it started dissipating there was nothing, no trace the storm had ever been there.”

The effectiveness of cloud seeding has been hotly debated. Boe points to evidence, published in reputable scientific journals, such as the Journal of Applied Meteorology and Climatology, that indicates seeding clouds for snowfall enhancement can show a five to 15 percent increase in precipitation. But these assessments are often done by painstaking analysis of weather radar outputs and other data and tend to be weighted down with caveats. A more thorough assessment entails lacing seeded clouds with a tracer that can later be detected in the actual rain or snowfall that makes it to the ground, but such projects are prohibitively expensive and still don’t necessarily confirm that the precipitation would have fallen anyway.

Measuring the success of hail suppression is just as difficult. “I’m not aware of any statistical evidence that it works,” says Harold Brooks, a senior research scientist at the National Severe Storms Laboratory in Norman, Oklahoma. “Mind you,” he adds, “it’s very difficult to design and carry out experiments to test it.” 

Perhaps the best analysis comes from Boe himself. “It is not a total solution but it works,” he says. “And it is comparatively cheap, and not doing it is so disastrous that our clients are happy to do it.”

A storm approaches in North Dakota.

A storm approaches the plains near Adams, North Dakota. (Photo: William Neuheisel/flickr) 

With climate change exacerbating the already delicate dynamic between weather and farming, one would imagine this niche industry to blossom. “We’re staying busy,” says Boe. “Interest is increasing, I think because of increasing water supply pressures.” He is hesitant to peg the increased interest to climate change, but says that, “what we do know is that there is increased demand for water.”

Back on the ranch, Wayne Mrnak is quick to defend weather mod. “I remember back when I was young we never expected to get a crop harvested completely without losing some to hail, and in some years losing all of it to hail.” But, he adds, “Since weather modification started, losses have gone down, and in the last five years we’ve had very little measureable hail damage.” 

It’s still summer though, and the black wedge of a thunderstorm can consume the horizon on almost any given day. And these final days and weeks before the harvest are crucial for crops.

“If I can only make it through till September and the harvest then I am golden,” says Mrnak, with an eye to the sky. “But if just one of them storms comes, I am done.” 

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