Thunderstorm Thunderstorm A thunderstorm, also known as an electrical storm, lightning storm, or thundershower, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Thunderstorms occur in a type of cloud known as a cumulonimbus. They are usually accompanied by strong winds, heavy rain, and sometimes snow, sleet, hail, or, in contrast, no precipitation at all. Thunderstorms may line up in a series or become a rainband, known as a squall line. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, and tornadoes.
Cross country running autumn and winter, and can include weather conditions of rain, sleet, snow or hail, and a wide range of temperatures. Cross country running is one of the disciplines under the umbrella sport of athletics, and is a natural terrain version of long-distance track and road running. Although open-air running competitions are pre-historic, the rules and traditions of cross country racing emerged in Britain. The English championship became the first national competition in 1876 and the International Cross Country Championships was held for the first time in 1903. Since 1973 the foremost elite competition has been the IAAF World Cross Country