 Tornadoes can develop quickly from severe thunderstorms. If you spot a tornado go at once into the basement or small central room in a sturdy structure. For your protection move to an interior room on the lowest floor of a building. A tornado watch remains in effect until 9 p.m. for South Central Iowa. Repeating, a severe thunderstorm warning has been issued until 5 p.m. for the following counties in Iowa, Lucas, Monroe and Wayne.