A large mesoscale convective system (MCS) which is about the size of the state of Ohio or Iowa and lasts at least 6 hours. Forming during the afternoon and evening, this is the peak time for associated severe weather. The complex normally reaches its peak intensity at night when heavy rainfall and flooding become the primary threat.
A large organized convective weather system comprised of a number of individual thunderstorms. The size of an MCC can be 1000 times larger than an individual air-mass thunderstorm.
Organized, persistent areas of deep convection noted in METSAT imagery during the warm season, especially over the US
A large complex of thunderstorms, generally round or oval-shaped, which normally reaches peak intensity at night. An MCC must meet certain criteria for size, duration, and shape. MCCs typically form during the afternoon and evening in the form of several isolated thunderstorms, during which the potential for severe weather is greatest. During peak intensity, the primary threat shifts toward heavy rain and flooding.
A cluster of thunderstorms covering an area of 100,000 kilometers or more. Convective circulation within this system encourages the growth of new thunderstorms for up to 18 hours.
(Abbreviated MCC.) A subset of mesoscale convective systems (MCS) that exhibit a large, circular (as observed by satellite), long-lived, cold cloud shield. The cold cloud shield must exhibit the following physical characteristics. Size: A - Cloud shield with continuously low infrared (IR) temperature ≤ −32°C must have an area ≥ 105 km2; and B - Interior cold cloud region with temperature ≤ −52°C must have an area ≥ 0.5 X 105 km2. Initiate: Size definitions A and B are first satisfied Duration: Size definitions A and B must be met for a period ≥ 6 h. Maximum extent: Contiguous cold cloud shield (IR temperature ≤ −33°C) reaches maximum size. Shape: Eccentricity (minor axis/major axis) ≥ 0.7 at time of maximum extent. Terminate: Size definitions A and B no longer satisfied. Alternatively, a dynamical definition of an MCC requires that the system have a Rossby number of order 1 and exhibit a horizontal scale comparable to the Rossby radius of deformation. In midlatitude MCS environments, the Rossby radius of deformation is about 300 km.
A large mesoscale convective system (MCS) which is about the size of the state of Ohio or Iowa and lasts at least 6 hours. Generally forming during the afternoon and evening, the complex normally reaches its peak intensity at night when heavy rainfall and flooding become the primary threat. Severe weather may occur at anytime.
A Mesoscale Convective Complex (MCC) is a large Mesoscale Convective System, generally round or oval-shaped, which normally reaches peak intensity at night.