Storms are formed when the movement of cold and warm air currents creates extreme air pressure difference. Extreme air pressure is created at an atmospheric level as warm wet air rushes, causing cold air to move towards the area where air pressure is lower, eventually creating a rotation.
The rotational movement of cold and warm air in the atmosphere is centered around an area of low air pressure that is surrounded by a high pressure system. The movement of the earth and the atmosphere starts this rotation, which then generates wind that is centered around it. The winds rotate clockwise in the southern hemisphere and counter-clockwise in the northern hemisphere.
A low and high air pressure system can be generated at a local level as hot air rises off the ground. This creates relatively small air disturbances such as whirlwinds or dust devils. The type of storm that is generated varies depending on temperature and weather conditions around the system. Cold storm systems can take the shape of an ice storm, blizzard or snowstorm. In dry or desert areas, firestorms, windstorms or a dust devil can be generated. Storms in tropical areas can take the form of a tropical cyclone or a thunderstorm.