Thunderstorms are expected to develop across portions of Iowa and Missouri this evening and may track into portions of northern Illinois late this evening and overnight. While the threat for severe thunderstorms is not particularly high, there is a some potential that a couple storms could produce marginally severe hail. The greatest threat lies south and west of a Rockford to Joliet to Paxton line. Elsewhere, showers and a few rumbles of thunder are possible. Additional showers and thunderstorms are possible on Monday.