A Numerical Study of the Evolution of a Mesoscale Convective Vortex on the Meiyu Front

The Advanced Research WRF (Weather Research and Forecasting) model is used to simulate the evolution of a mesoscale convective vortex (MCV) that formed on the Meiyu front and lasted for more than two days. The simulation is used to investigate the underlying reasons for the genesis, intensification, and vertical expansion of the MCV. This MCV is of a type of mid-level MCV that often develops in the stratiform regions of mesoscale convective systems. The vortex strengthened and reached its maximum intensity and vertical extent (from the surface to upper levels) when secondary organized convection developed within the mid-level circulation. The factors controling the evolution of the kinetic and thermal structure of the MCV are examined through an analysis of the budgets of vorticity, temperature, and energy. The evolution of the local Rossby radius of deformation reveals the interrelated nature of the MCV and its parent mesoscale convective system.