* WHAT. Flash flooding caused by excessive rainfall is possible. * WHERE. Portions of central and northern Iowa. * WHEN. From 1 AM CDT Tuesday through Tuesday evening. * IMPACTS. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas.

* WHAT. Flooding caused by excessive rainfall is possible. * WHERE. Portions of Iowa, including the following counties, Harrison, Monona, Pottawattamie and Shelby, and portions of Nebraska, including the following counties, Boone, Burt, Butler, Colfax, Cuming, Dodge, Douglas, Madison, Platte, Sarpy, Saunders, Stanton, Thurston, Washington and Wayne. * WHEN. From 10 PM CDT this evening through Tuesday evening. * IMPACTS. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS. - Multiple rounds of heavy precipitation is expected with an increasing potential for training thunderstorms to develop after midnight. A second round of heavy rain is expected Tuesday late morning and afternoon. This will bring the threat for flash flooding and river flooding across portions of northeast Nebraska, east-central Nebraska, and west- central Iowa. - http://www.weather.gov/safety/flood