Mesoscale convective systems (MCS) are large, organized clusters of thunderstorms that cover an area of at least 100 km in diameter. They are typically associated with severe weather events such as heavy rainfall, strong winds, hail, and tornadoes. MCSs can last for several hours to days and often form along boundaries between air masses with differing temperatures and moisture levels. Researchers study MCSs to better understand their formation, structure, and dynamics in order to improve weather forecasting and warning systems. They use a combination of observational data from radar, satellites, and ground-based instruments, as well as numerical models to simulate and predict the behavior of MCSs. By studying MCSs, researchers aim to improve our ability to anticipate and mitigate the impacts of severe weather events associated with these systems.