The Storm Prediction Center has issued a Severe Thunderstorm Watch effective until Midnight for the following counties, Adair, Adams, Appanoose, Audubon, Carroll, Cass, Clarke, Crawford, Dallas, Davis, Decatur, Guthrie, Jasper, Lucas, Madison, Mahaska, Marion, Monroe, Polk, Poweshiek, Ringgold, Taylor, Union, Wapello, Warren, Wayne, Fremont, Harrison, Mills, Monona, Montgomery, Page, Pottawattamie and Shelby. Thunderstorms are beginning to develop over southern Iowa into eastern Nebraska. These storms will have the capability of producing large hail and strong damaging winds. Heavy rainfall is also possible. A Flash Flood Watch is in effect for the area as well.