A "major tornado outbreak" brewing across nine states in the central United States is adding to insured losses that already may have reached $6.5 billion this season, according to an industry group.
Tornadoes and thunderstorms have caused at least $3 billion in insured losses and perhaps more than double that, said Robert Hartwig, president and economist at the Insurance Information Institute in New York.
"It is going to be an earnings event to insurers," Mr. Hartwig said. "These are outsized losses."
A tornado watch, meaning the deadly storms may develop, was posted Wednesday from Mississippi to Ohio, according to the National Weather Service.
Storm damage from flipped trucks, downed power lines, and damaged homes has been reported in Illinois, Indiana, Kansas, and Missouri, according to the storm center in Norman, Okla.
So far in 2011, tornadoes have killed 504 people, according to the center, which is investigating 1,228 twister reports. Major outbreaks have damaged the St. Louis airport, flattened Tuscaloosa, Ala., and destroyed a large part of Joplin, Mo. In the three years prior to this year, 192 people were killed.
Mr. Hartwig said losses from thunderstorms and tornadoes have been rising since 2008. From 1990 to 2009, tornadoes caused $97.8 billion in insured U.S. losses, second only to hurricanes, responsible for losses of $152.4 billion.
"This is the fourth consecutive year thunderstorm and tornado losses are reaching record levels," he said. He said the industry is positioned to pay the losses.