Scientists set out to debunk cloud seeding myth

Laramie, Wyoming – Some might try to blame this week's snowy weather on a cloud seeding program underway in Wyoming. But the scientists running the project say let's wait til the results are in. They're doing the nation's only scientific study on whether cloud seeding increases snowfall and in the process, they hope to banish some misconceptions about seeding the clouds. Wyoming Public Radio's Addie Goss reports.


Cloud seeding suffers from an image problem. Movies like the 1956 film "The Rainmaker" don't help.

You really mean you can bring rain?
It's been done, brother, it's been done.
Where? How? Sodium chloride. Pitch it up high, right up to the clouds, electrify the cold front, neutralize the warm front, barametrecize the tropperpause, magnetize acclusions in the sky!
In other words, BUNK!

In the early 20th century, rainmakers...con men... toured the States looking for people to dupe. They'd fire rockets into the air. Sometimes the rain would come. Often it wouldn't.

B2.8 You can't make rain. You can't make precipitation. You know, that's the Almighty's realm.

Bruce Boe is a modern-day cloud seeder and a scientist... and he's using science to show that cloud seeding isn't bunk. It may not produce rain and snow out of thin air... but Boe says seeding can make snow and rainfall heavier.

B4 You have to do the right thing at the right time at the right amount, you have to be very meticulous about what you do.

Boe works with Weather Modification Incorporated in North Dakota. The company is in demand. States across the West are thirsting for fuller rivers and streams. Wyoming is one of them. But in 2005, when Wyoming decided to fund a cloud seeding program, they wanted to know it would actually work.

Barry Lawrence oversees the program for the state.

L1.3 If we're gonna get into this for the long haul as a potential water management strategy, we want to make sure it's an effective way of increasing snowpack and ultimately stream flow.

Most science experiments take place in a lab. This one takes place over two mountain ranges - the Sierra Madres and the Snowies in southeastern Wyoming. When conditions are right, Bruce Boe's company seeds one of the mountain ranges. The other range goes unseeded. Scientists at NCAR...the National Center for Atmospheric Research in Boulder...then measure the difference in snowfall between the two ranges.

Today Boe stands on sagebrush-covered foothills on the western slope of the Snowies. Overhead is a 25-foot-tall scaffold with a tank of cloud seeding solution at the bottom and a propane burner at the top.

123-3 There it is? See the orange now? We're actually producing ice nuclei.

To understand how cloud seeding works, it helps to know how snow normally falls. When the wind blows in Wyoming, clouds bunch up against the mountains and start to rise. Inside the clouds are tiny water molecules. As they rise, they get colder. But as Boe explains, they don't freeze into ice crystals - even when they reach the standard 32 degrees.

B5 They're still moving too fast to arrange themselves into crystals, so they don't.

They need some help. And they get it from tiny particles called aerosols, like bits of clay or soil that float around in the air.

B7 And some of these have shapes similar to water ice.

These tiny specks of dust work like a mold. Liquid water collects around them and takes the shape of ice. But some of the molds are imperfect. That's where cloud seeding comes into play. Cloud seeders launch silver iodide into the air as a better aerosol.

B16 Silver iodide works because its crystalline shape is very similar to that of natural ice.

Time will tell whether this seeding project will actually increase snow pack. Roy Rasmussen at NCAR is one of the scientists looking into that question. He says it's hard to tease apart the effect of cloud seeding from natural changes in weather. For example, did the project cause some of this week's snowfall? Or was the snow just heavy on its own?

3 The problem is what you're looking for is a small signal in a lot of noise.

Within a few years' time, the NCAR team will learn how well the seeding worked. The hope is it will increase snow pack by 15 to 20 percent. That may not sound like much but Barry Lawrence with the state says it would be a big deal.

L2.4 The municipalities that rely on that water, it recharges the groundwater system, the irrigation systems that rely on that water, it helps make everybody whole.

Meanwhile cloud seeder Bruce Boe hopes this project may clear up some rumors about cloud seeding. While some people think seeding is bunk, others think it's so powerful that they believe Boe's project caused last year's closures of Interstate 80.

B2.4 Two nights ago at the Saratoga inn the manager Kathy are you guys the cloud seeders? Yeah, we're the cloud seeders well stop it! And she was giving her a hard time. We told her, no, Kathy, the Almighty had more to do with that than we did. It was just a heavy snow season. And she said, well, I've been talking to him too.

Boe says... wait a couple years and then we'll know how much snow we can blame on him.

For Wyoming Public Radio, I'm Addie Goss.


Some might try to blame this week's snowy weather on a cloud seeding program underway in Wyoming. But the scientists running the project say let's wait til the results are in. They're doing the nation's only scientific study on whether cloud seeding increases snowfall and in the process, they hope to banish some misconceptions about seeding the clouds. Wyoming Public Radio's Addie Goss reports.


Cloud seeding suffers from an image problem. Movies like the 1956 film "The Rainmaker" don't help.

You really mean you can bring rain?
It's been done, brother, it's been done.
Where? How? Sodium chloride. Pitch it up high, right up to the clouds, electrify the cold front, neutralize the warm front, barametrecize the tropperpause, magnetize acclusions in the sky!
In other words, BUNK!

In the early 20th century, rainmakers...con men... toured the States looking for people to dupe. They'd fire rockets into the air. Sometimes the rain would come. Often it wouldn't.

B2.8 You can't make rain. You can't make precipitation. You know, that's the Almighty's realm.

Bruce Boe is a modern-day cloud seeder and a scientist... and he's using science to show that cloud seeding isn't bunk. It may not produce rain and snow out of thin air... but Boe says seeding can make snow and rainfall heavier.

B4 You have to do the right thing at the right time at the right amount, you have to be very meticulous about what you do.

Boe works with Weather Modification Incorporated in North Dakota. The company is in demand. States across the West are thirsting for fuller rivers and streams. Wyoming is one of them. But in 2005, when Wyoming decided to fund a cloud seeding program, they wanted to know it would actually work.

Barry Lawrence oversees the program for the state.

L1.3 If we're gonna get into this for the long haul as a potential water management strategy, we want to make sure it's an effective way of increasing snowpack and ultimately stream flow.

Most science experiments take place in a lab. This one takes place over two mountain ranges - the Sierra Madres and the Snowies in southeastern Wyoming. When conditions are right, Bruce Boe's company seeds one of the mountain ranges. The other range goes unseeded. Scientists at NCAR...the National Center for Atmospheric Research in Boulder...then measure the difference in snowfall between the two ranges.

Today Boe stands on sagebrush-covered foothills on the western slope of the Snowies. Overhead is a 25-foot-tall scaffold with a tank of cloud seeding solution at the bottom and a propane burner at the top.

123-3 There it is? See the orange now? We're actually producing ice nuclei.

To understand how cloud seeding works, it helps to know how snow normally falls. When the wind blows in Wyoming, clouds bunch up against the mountains and start to rise. Inside the clouds are tiny water molecules. As they rise, they get colder. But as Boe explains, they don't freeze into ice crystals - even when they reach the standard 32 degrees.

B5 They're still moving too fast to arrange themselves into crystals, so they don't.

They need some help. And they get it from tiny particles called aerosols, like bits of clay or soil that float around in the air.

B7 And some of these have shapes similar to water ice.

These tiny specks of dust work like a mold. Liquid water collects around them and takes the shape of ice. But some of the molds are imperfect. That's where cloud seeding comes into play. Cloud seeders launch silver iodide into the air as a better aerosol.

B16 Silver iodide works because its crystalline shape is very similar to that of natural ice.

Time will tell whether this seeding project will actually increase snow pack. Roy Rasmussen at NCAR is one of the scientists looking into that question. He says it's hard to tease apart the effect of cloud seeding from natural changes in weather. For example, did the project cause some of this week's snowfall? Or was the snow just heavy on its own?

3 The problem is what you're looking for is a small signal in a lot of noise.

Within a few years' time, the NCAR team will learn how well the seeding worked. The hope is it will increase snow pack by 15 to 20 percent. That may not sound like much but Barry Lawrence with the state says it would be a big deal.

L2.4 The municipalities that rely on that water, it recharges the groundwater system, the irrigation systems that rely on that water, it helps make everybody whole.

Meanwhile cloud seeder Bruce Boe hopes this project may clear up some rumors about cloud seeding. While some people think seeding is bunk, others think it's so powerful that they believe Boe's project caused last year's closures of Interstate 80.

B2.4 Two nights ago at the Saratoga inn the manager Kathy are you guys the cloud seeders? Yeah, we're the cloud seeders well stop it! And she was giving her a hard time. We told her, no, Kathy, the Almighty had more to do with that than we did. It was just a heavy snow season. And she said, well, I've been talking to him too.

Boe says... wait a couple years and then we'll know how much snow we can blame on him.

For Wyoming Public Radio, I'm Addie Goss.