LiveScience: In May, residents of Tornado Alley braced themselves as the region's usual spring thunderstorms began popping up across the plains, bringing heavy rainfall that caused flash floods, high winds, hail and tornadoes. On May 20, the town of Moore, Okla., seemingly a perennial tornado target, was struck by a monster storm that was 1.3 miles (2 kilometers) wide at its peak, carving a 17-mile-long (27 km) path of destruction through the Oklahoma City suburb with winds that reached 210 mph (338 km/h).
While...