What is the definition of a Mesoscale Convective System (MCS)?

A Mesoscale Convective System (MCS) is defined as a collection of thunderstorm cells that are interacting and organized in a way that they produce significant weather phenomena over a large area. MCSs are typically characterized by their ability to develop and sustain a structure that can resolve itself into various forms, such as clusters or lines of thunderstorms. This system often leads to the production of heavy rainfall, severe winds, and sometimes even tornadoes, as the thunderstorms work in concert.

The definition emphasizes the collective nature of the storm cells and how they create an organized system that can influence the weather significantly, often over a larger area than just a single thunderstorm. This behavior is crucial in understanding weather patterns, forecasting, and assessing potential impacts on aviation, particularly for operations like those at American Airlines.

The other choices do not capture the essence of an MCS. While a single thunderstorm, severe weather warning, or a low-pressure system may relate to weather events, they do not represent the collaborative and structured aspect of an MCS, which involves multiple thunderstorm cells functioning together.