The precipitation life cycle of mesoscale convective complexes over the central United States

Abstract

The typical MCC's 10-12 h evolution displays a fairly consistent sequence of events, including the monotonic areal expansion of its anvil from its formation to its maximum size, followed by the monotonic shrinkage of the colder cloud top areas as the system weakens and dissipates. Primarily within the growth phase of this cycle, a characteristic IR signature reflects the MCC in its most intense, mesoconvective stage, which lasts ~4 h and during which the coldest cloud top area reaches its largest extent. The sample reveals several interesting tendencies: 1) smaller, less-organized systems tended to be "drier' than similar-sized but better-organized MCCs; 2) large systems were "rainier' than smaller ones; 3) large systems tended to be "rainier' in the eastern part of the sample domain than in the western part, but this was not so for small systems; and 4) the eastern systems, had a more coherent and intense core of heavy precipitation through their life cycle than the western systems. -from Authors