华南暖区暴雨研究进展

华南前汛期暴雨预报一直是我国大气科学界的一个研究热点，特别是发生在锋前的暖区暴雨，由于其天气尺度斜压性强迫不明显，环境大气水汽含量丰富，热动力不稳定性强，边界层触发机制复杂，以及特殊的地形和海陆热力差异的外强迫作用，导致暴雨突发性强，地域性特征显著，也是困扰预报业务人员的难点问题。目前我国预报业务中使用的全球数值预报模式对暖区暴雨的预报能力十分有限，高分辨率中尺度数值模式的预报效果也不尽人意。该文回顾了近40年华南前汛期暴雨大部分研究成果，针对华南暖区暴雨的提出及典型背景场、暖区暴雨与低空急流的关系、暖区中尺度对流系统的形成及传播、暖区暴雨触发机制等独特的天气动力学特征进行了系统梳理与分析，并依据前人研究成果及中央气象台预报实践经验，总结提炼了3类华南暖区暴雨类型——边界层辐合线型、偏南风风速辐合型，以及强西南急流型的天气系统配置及触发因子。最后提出针对华南暖区暴雨需要进一步研究的科学问题。

A Review of Studies on Prefrontal Torrential Rain in South China

The torrential rain forecast during pre-summer flood season in South China attracts a lot of research interests. The rainstorm occurring in prefrontal zone strong shows abrupt and significant regional characteristics, and it's especially difficult to solve in operational forecast, due to its inapparent synoptic scale baroclinity forcing, rich moisture content, strong environmental atmospheric thermodynamic instability, complex triggering mechanism in boundary-layer, external forcing effect of special terrain and land-sea thermal difference. For the torrential rain occurs in prefrontal district, forecasting capabilities of various global numerical weather prediction models used in China Meteorological Administration are very limited, and forecast results of high-resolution meso-scale numerical models are also disappointing. Most of results on torrential rain during pre-summer flood season in South China since the 1970s are reviewed. The unique synoptic and dynamics characteristics are systematically analyzed, such as the first proposing of the rainstorm occurs in prefrontal zone in South China and its typical synoptic scale background, the relationship between the rainstorm in prefrontal zone and the low level jet (LLJ), the formation and propagation of meso-scale convective system (MCS) produced, and triggering mechanisms of the torrential rain. Finally, according to these studies and practical experiences of China Central Meteorological Observatory, synoptic system configurations and triggering factors for torrential rain in prefrontal zone in South China are summarized as three types: The pattern of boundary layer convergence lines, the pattern of southerly wind convergence and the pattern of stronger southwest jet, and scientific problems which require further in-depth study are proposed.