The first day of summer brought threatening weather to parts of Iowa and Thursday’s violent storms forced Waterloo-area residents to take cover — twice. Warning sirens sounded in Black Hawk County shortly after four p.m. A wall cloud, with rotations, above the Waterloo Regional Airport prompted the tornado warning. The threatening storm cell slowly moved northeast away from the metro area and weakened as it headed toward Bremer County.

Sirens sounded a second time in Black Hawk County about 90-minutes later when law enforcement spotted a twister that briefly touched down in a field south of Evansdale. Yesterday’s storms also spawned tornadoes near Aplington and Shell Rock in neighboring Butler County. No major damage or serious injuries were reported with any of the tornadoes. The storms dumped more than an inch of rain on the Cedar Valley and dropped nickle-sized hail in both Cedar Falls and Greene.

 Black clouds dumped heavy rain and large hail, while winds topped out at 80-miles an hour in Poweshiek County. At least four funnel clouds or tornadoes were spotted near Ames, Fort Dodge, Waterloo and elsewhere.

Forecasters say Iowa may see more severe weather today. National Weather Service meteorologist, Jeff Johnson, says the twisters caused little significant damage.

Johnson says, "We did have some other damage from straight-line wind, here and there some trees down, and we did have some pretty good-sized hail up in north-central Iowa, up over the two-inch mark, northeast of Fort Dodge, up in Humboldt County and parts of Hancock County."

Johnson says conditions are right for another widespread round of heavy thunderstorms this afternoon. He says they’re watching developments carefully but at the moment, storms appear likely this afternoon, particularly in central or southern Iowa toward the Missouri border.

A number of communities in the eastern half of the state report heavy rain totals overnight, including five-inches in Iowa City. Several eastern Iowa counties are under flood and flash flood warnings and watches this morning.

Audio:Elwin Huffman reports on Eastern Iowa storms.:41 MP3