Following an increasingly wet spring and especially the relentless downpours of late, runoff from thunderstorms is pushing up Mississippi River levels for the second time this spring.
Portions of the central Plains and part of the Midwest have received over a half a foot of rain during the last week of May. In some cases, almost as much rain fell during a 24- to 36-hour period.
The rain has been falling and will continue to focus on a large part of Iowa, eastern Nebraska, northern Illinois and northern Missouri. Lately, the heavy rain has been reaching farther southwestward and northeastward into portions of Kansas, Wisconsin and Michigan.
Multiple rivers in Iowa, at the center of the heaviest rainfall, were in flood or expected to cause flooding.
The Floyd and Skunk rivers in Iowa recently reached record high levels. The Iowa River at Marengo, Iowa, was a little over a foot away from reaching a record high level Wednesday.
The Iowa, Missouri and Illinois rivers all empty into the Mississippi River above St. Louis.
Moderate to major flooding of the Mississippi River is forecast by National Weather Service hydrologists from about where the Iowa River joins in to near Chester, Ill.
The river is not expected to crest at St. Louis until next week.
High flow rates and river level rises will work downstream into the middle of June.
A number of barges broke loose on the Mississippi during the siege of high water in April.