佛山市5月大暴雨特征分析与预报判据

An Analysis of Characteristics and Forecasting Criteria of Severe Heavy Rain in Foshan in May

对背景流场、触发条件、物理量等方面的分析表明,佛山市5月大暴雨的产生,深厚的热带暖湿气流起着决定作用,而南支槽、能量锋区、低层中间尺度辐合系统和中尺度辐合带上的小涡旋直接起着触发作用,文中结合12场大暴雨分析和值班经验,总结归纳出10条发生大暴雨的必要条件。

By analyzing environmental circulation fields, triggering conditions and diagnostic elements, it is found that the warm moist flows in the deep layer of the tropical atmosphere plays a decisive role in occurrence of severe heavy rain in Foshan in May, while southern troughs, energy front, mesoscale convergent systems and small vortices in lower layer act as triggering conditions directly. Furthermore, ten conditions necessary to induce severe heavy rains are concluded from analyses of twelve heavy rain occurrences and forecasting experience.