Purdue University students are testing new software that may track and warn about tornadoes, such as this one which struck Rochelle, Ill., in early April. Walker Ashley/AP hide caption

toggle caption Walker Ashley/AP

A car is abandoned on a flooded street following heavy rains and flash flooding in Bay Shore, N.Y., on Wednesday. The South Shore of Long Island along with the tri-state region saw record-setting rain that caused roads to flood. Andrew Theodorakis/Getty Images hide caption

toggle caption Andrew Theodorakis/Getty Images

Data released Tuesday shows that the deadly El Reno tornado that struck Friday was the widest every recorded in the U.S., at 2.6 miles. National Weather Service hide caption

toggle caption National Weather Service

Jan. 21, 2012: A winter scene in Brooklyn, N.Y. Snow may be a relatively rare sight this coming winter in the U.S. Spencer Platt/Getty Images hide caption

toggle caption Spencer Platt/Getty Images

Doug Jones, owner of Piedmont Biofarm in Pittsboro, N.C., waters vegetables as temperatures in the South soar, Friday, June 29. Triple-digit temperatures are expected for several days in North Carolina. Gerry Broome/AP hide caption

toggle caption Gerry Broome/AP

Branches and power lines littered the nation's capital after bruising storms swept through the Mid-Atlantic region on Friday night. Win McNamee/Getty Images hide caption

toggle caption Win McNamee/Getty Images

NPR thanks our sponsors

Become an NPR sponsor