The satellite image for April 27, 2011 shows the southeastern United States, Central America and the Gulf of Mexico -- along with tornado tracks (red solid lines, with the thickest indicating a magnitude 5 tornado, descending to magnitude 1 for the thines

UI researchers link smoke from fires to tornado intensity

Study finds smoke from Central America intensified 2011 tornadoes
University of Iowa researchers have linked smoke from fires to tornado intensity. They examined the effects of smoke—resulting from spring agricultural land-clearing fires in Central America—transported across the Gulf of Mexico and encountering tornado conditions already in process in the United States.
satellite image of Hurricane Sandy

UI researcher predicts more intense North Atlantic tropical storms

Study finds high carbon dioxide levels increase storm strength
A study published in the prestigious Journal of Climate, the official publication of the American Meteorological Society, finds that tropical storms that make their way into the North Atlantic, and possibly strike the East Coast of the United States, likely will become more intense during the rest of this century.