Convective and meso-scale measurements of convective initiation and evolution associated with seabreeze front and outflow boundary

During the warm season over the Kanto Plain of Japan, strong isolated thunderstorms are often responsible for flooding and other rainfall-related hazards. Forecasting of quantitative precipitation associated with these mesoscale systems is known to be an important challenge. Accurate prediction of precipitation and its distribution from isolated thunderstorms in turn depends on the predictability of timing, location of convective initiation and the subsequent evolution of these thunderstorms. However, it has been difficult because of the poor knowledge of the convective initiation and evolution processes, which arise in part from the lack of data of winds, temperature, and water vapor with high temporal and spatial resolutions. For example, the scale of the majority of isolated thunderstorms is typically 10km and localized convection in unstable air masses which lead to the development of these storms has more smaller-scale structure. It would be highly desirable to resolve both within and around the storm. The Tokyo Metropolitan Area Convection Study (TOMACS) has been designed for better understanding of various mesoscale mechanisms over the Kanto Plain. As a part of the project, our main objectives is to characterize and validate thermodynamic and kinematic structures of thunderstorms, in the context of a better knowledge of the physical processes of rain formation, maintenance, and evolution, as well as future urban meteorological and hydrological applications. In this paper, convective initiation and evolution case studies during the TOMACS field experiment over the Kanto Plain in Japan will be described.