NEW : 11 possible tornadoes are reported across several states . NEW : Iowa 's governor declares a disaster in one county . NEW : A tornado hits the town of New Madrid, Ohio. Baseball-size hail pelts parts of Nebraska as a storm moves in .
NEW : 11 possible tornadoes are reported across several states . NEW : Iowa 's governor declares a disaster in one county . NEW : Forecasters warn that heavy rains could cause flash floods . Baseball-size hail pelts parts of Nebraska as a storm moves in .