Any precipitation falls the long distance through the clouds towards the Earth's surface. As the rising air reaches its dew point temperature, water vapor condenses into water droplets or ice, reducing pressure locally within the thunderstorm cell.
As the warm, moist air moves upward, it cools, condenses, and forms a cumulonimbus cloud that can reach heights of over 20 kilometres (12 mi). However, some kind of cloud forcing, whether it is a front, shortwave trough, or another system is needed for the air to rapidly accelerate upward. Thunderstorms result from the rapid upward movement of warm, moist air, sometimes along a front.
While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction. Some of the most persistent severe thunderstorms, known as supercells, rotate as do cyclones. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, and tornadoes. Thunderstorms may line up in a series or become a rainband, known as a squall line. They are usually accompanied by strong winds and often produce heavy rain and sometimes snow, sleet, or hail, but some thunderstorms produce little precipitation or no precipitation at all. Thunderstorms occur in a type of cloud known as a cumulonimbus.
Relatively weak thunderstorms are sometimes called thundershowers. Problems playing this file? See media help.Ī thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder.