Dynamical Diagnosis And Numerical Simulation Of A Mesoscale Convective Complex

Dynamical diagnosis, numerical simulation and theory analysis are done on genesis condition, structure, propagation and development mechanism of a mesoscale convective complex (MCC) which caused the first torrential rain in the Meiyu period of Yangtze River and Huaihe River Basins in June 22-23, 2003. Reasons that the wrong forecast of the MCC was made by numerical weather prediction models and official forecasts are investigated and some cues to improve are suggested, too.The MCC formed and developed under the favorable environment by the interaction of weather systems of low and high latitudes in abrupt change period of East Asia general circulation. The MCC is composite of meso- , meso- and meso- scale convective systems which have different structure and motion features. Although circularly approximately on the satellite imagery, the MCC shows linear distributions of radar echo, torrential rain, thunderstorm, cumulonimbus and mesoscale physical parameters as a squall line. The multi-scale structures of MCC cause its multi-scale propagations that meso- , meso- and meso- scale convective systems have their motion features. The movement of the MCC is a mixture effect of various motions of meso- , meso- and meso- scale systems. The MCC develops mechanism is analyzed based on moist thermal wind theory, relatively mesoscale convectively generated vortex, Potential Vorticity Thinking, inertial instability theory and so on. The meso- and meso- scale movement, structure and developing process of the MCC are simulated successfully by Weather Research Forecast model(WRF).