A review of the warm-sector rainstorms in China

Many research focused on the characteristics of warm-sector rainstorms in South China during past decades. The rainstorms occurring in warm sectors show abrupt and significantly localized characteristics. The triggering mechanism is complex due to weak synoptic baroclinic forcing, strong environmental instability, as well as external forcing including special topography features and land-sea difference. Nowdays the forecast skills of numerical weather prediction models are still limited. The synoptic characteristics of warm-sector rainstorm in South China have been studied since 1980s, and the development characteristics of convective systems in the warm region have been summarized. It is revealed that the extreme precipitation events in the warm region were closely related to the development of the quasi-stationary linear convection systems. Recently, through several scientific experiments in South China, further scientific understanding has achieved on the convective process, boundary layer physics and cloud physics related to the development of warm-sector rainstorms in South China. Based on the observational analysis of boundary level jet and surface cool pool evolution near coastal area of South China, the convective triggering mechanism has been more clearly understood than before. The studies on the torrential warm-sector rainstorms in recent 40 years are reviewed in this article. The synoptic condition and dynamics of warm-sector rainstorms are analyzed, such as the first proposing of the concept for warm-sector rainstorms in different areas and its multi-scale synoptic characteristics, the relationship between the rainstorm in warm sector and Low Level Jet(LLJ), the development characteristics of meso-scale convective system(MCS). Finally, scientific problems are proposed for further studies.