. . "line of thunderstorms with hurricane-force winds" . . "a severe storm" . "June 2012 North American derecho" . "strong storms" . . "derecho" . "12\u201313, 2013 derecho series" . "June 2012 North American derecho" . . . . "severe thunderstorm in the summer of 2012" . . "June 2012" . . "sweeps" . "June 2012 derecho storm" . . .