A large organized convective weather system comprised of a number of individual thunderstorms. It normally persists for several hours and may be rounded or linear in shape. This term is often used to describe a cluster of thunderstorms that does not meet the criteria of a mesoscale convective complex (MCC).
MESOSCALE CONVECTIVE SYSTEM (MCS)
Meaning of MESOSCALE CONVECTIVE SYSTEM (MCS) in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012