Tornado near South Amana. Photos by Randy Graesser

Severe weather hit wide sections of eastern Iowa last night, with a tornado touching down in Iowa County about 6 P.M., causing damage to crops, farmsteads and homes near Williamsburg and Conroy.

Andy Ervin, a meteorologist with the National Weather Service in Davenport, says the twister landed near Interstate 80 and was seen by many dozens of travelers.

“We have some outbuildings, farm damage,” Ervin says. “We are going to send out a survey team today to check out that tornado damage and we’ll get a reading on that and the exact path as well.” The Dubuque airport clocked winds of 75 miles an hour, toppling trees and power lines, leaving as many as 11,000 homes in the dark at the peak of the storm. Ervin says that was due to what’s known as a “supercell.”

“We had one storm merge with another and it produced a wind event,” Ervin says. “We have a lot of tree damage being reported, enough that even the roads were impassible due to the amount of trees down there.”

The Dubuque County town of Holy Cross reports inch-diameter hail, while in far northeast Iowa, Clayton County reports flash flooding after more than nine inches of rainfall during the storm.

The heaviest amounts of rain were across Clayton County and into Wisconsin’s Grant County, Ervin says, while Dubuque County had 2-to-6 inches of rain. Forecasters say Iowa may have more severe weather this afternoon and tonight. Also, a heat advisory is posted for Iowa’s southeastern half from noon until 7 P-M. Heat indices may reach 105-degrees late this afternoon.

NWS photos courtesy of Randy Graesser.