Precipitation Characteristics of a Dual Mesoscale Convective Complex

摘要

Flash flooding resulted from two Mesoscale Convective Complexes (MCCs, Maddox, 1980) that formed nearly simultaneously and traversed roughly the same geographical area. In addition to heavy rains, hail damage and strong winds occurred. The precipitation characteristics, internal structure, and evolution of the dual MCC are presented using hourly surface mesoanalyses, WSR-57 radar composites and enhanced IR satellite imagery. The analyses suggest that certain features are similar to both tropical squall line systems and middle-latitude squall lines. The MCCs considered here are very complex and distinctly three dimensional. Time-lapse radar film revealed an intense meso-beta-scale circulation embedded in the second MCC. Extremely heavy rains and damaging winds are associated with this feature. As the MCC weakened, this small-scale cyclone gradually evolved into a larger, but less intense meso-alpha-scale cyclone that produced moderate rainfall for several hours. These features are examples of this MCC's complexity and distinguish this middle-latitude system from tropical squall line systems.