Frontal-Wave-like Evolution in Some Mesoscale Convective Complexes

Abstract

Abstract In some mesoscale convective complexes (MCCs) the convective regions assume a configuration that resembles a frontal wave, while in other systems the configuration is not classifiable. We examined the evolution of the internal structure and flow of two MCCs that were part of an episode of systems that propagated along a stationary front, and in which the convective activity evolved from a chaotic to a frontal-wave-like pattern. The development of mesoscale vorticity and its possible relationship to the spatial patterns are explored. Each system developed two dissimilar convective bands that together formed an open-wave pattern. The greatest number of convective clusters and the greatest midlevel convergence and high-level divergence were found in a core region (the “apex” of the wave) where the bands intersected. The north-south convective line was less enduring than the core convection or the cast-west band; it evolved from outflow boundaries of the early storms preceding the mesosystem. A conce...