The Storm Prediction Center has issued a Severe Thunderstorm Watch effective until 11pm this evening for the following counties, Allamakee, Benton, Buchanan, Cedar, Clayton, Clinton, Delaware, Dubuque, Fayette, Henry, Iowa, Jackson, Jefferson, Johnson, Jones, Keokuk, Linn, Louisa, Muscatine, Scott and Washington. Thunderstorms will rapidly develop along the cold front that is moving through the eastern sections of the state. Large hail and damaging winds will be the main threats with the storms. Also some of the storms may produce heavy rainfall.