Tornadoes form from severe thunderstorms, particularly supercells, which are rotating storm systems. When warm, moist air near the ground rises and meets cooler, drier air above, it creates instability. This difference in temperature and humidity can lead to the development of a rotating updraft called a mesocyclone. As the mesocyclone intensifies, it can extend downward, forming a visible funnel cloud. If this funnel touches the ground, it becomes a tornado. The strength of a tornado is measured using the Enhanced Fujita Scale, which categorizes them based on the damage they cause.