Louisville firm helps track lightning strikes

The dramatic video of Hurricane Irma being broadcast as the storm churns through Florida shows wind-whipped trees, a toppled crane and sheets of rain. Lightning lurks in hurricanes as well, and a company in Colorado supplies systems that are tracking Irma’s strikes.

“One of the things about lightning in hurricanes is it isn’t discussed often,” said Kevin Petty, chief science officer for Vaisala, a Finnish company with North American headquarters in Louisville. “We tend to focus on wind and storm surge because that is obviously very important. But lightning can still be a hazard.”

On Sunday morning, when the storm made landfall in the Florida Keys, and wind and rain pummeled Miami, Vaisala’s lightning systems detected bolts generated near Orlando, approximately 183 miles from Key West.

The lightning strikes flashed in rain bands that spiral inward toward the center of the storm. “That is quite a distance away from the eye of the storm,” Petty said.

“There is quite a bit of lightning in some of those rain bands, and those rain bands can also produce tornadoes,” he added.

Vaisala has seen an average of 45 lightning strikes per minute in Irma, and some peaks of more than 60 per minute.

The National Weather Service uses lightning detection systems from Vaisala and other vendors all around the world, said Kurt Van Speybroeck, weather service meteorologist in Fort Worth, Texas.

Hurricane deaths are not often linked to lightning strikes, Van Speybroeck said. “Most people are in a hardened building, away from a window. Generally, people die from lightning by being outside in an exposed area.”

Vaisala collaborates with Colorado State University, the National Center for Atmospheric Research in Boulder and other research institutions and universities along the Front Range to “leverage some of the research going on to bring science-based products to market,” Petty said.

The company has 150 employees in Louisville and has offices in Boston, Seattle and Tucson.