Emarie Price conducted research on rain and floods. The water cycle involves water evaporating and forming tiny water drops in clouds, which grow into larger clouds that become too heavy and release rain, starting the cycle again. Raindrops range in size from 1/100 to 1/4 inch and fall between 7 to 18 miles per hour. Floods occur after days of heavy rain or snowmelt cause rivers to overflow their banks, and even 2 feet of water can float large vehicles. Flash floods are the leading weather-related cause of death in the United States.