Flood warnings are posted for some three-dozen counties across Iowa this morning after heavy rain most of the weekend. Severe storms also brought at least one tornado to eastern Iowa on Sunday afternoon. Jeff Johnson, a meteorologist at the National Weather Service, says flooding may worsen by midweek.

Most of the flood warnings are the result of the widespread weekend rain which is expected to impact rivers and streams, especially across central and eastern Iowa over the next couple of days. Johnson says virtually all of the state got at least some rain since Friday, with some areas getting many more inches of than others.

Weekend rainfall totals for some areas exceed six inches in the northeast, including parts of Marshall and Black Hawk counties, while heavy rain also fell in the southwest, over Cass and Guthrie counties. At least one tornado hit Linn, Delaware and Dubuque counties late Sunday afternoon, downing trees and power lines, damaging several farmsteads and destroying R-Vs parked at a Central City campground. No injuries are reported. Johnson notes that parts of Colorado, including Denver, are seeing snow this morning.

"That’s one of the reasons why we have this weather," he says. "You get the clash of the air masses in the spring months. You get all that instability and atmospheric energy and it all produces the thunderstorm activity we’ve seen." Johnson says much of Iowa may see a break from the clouds tomorrow (Tuesday) but more rain is expected by Wednesday and on toward the weekend. He adds, it shouldn’t get cold enough in Iowa for any snowfall.