2003年山东雨季最后一场大暴雨过程分析

A Case Analysis of Last Rainstorm in Shandong Rainy Season of 2003

利用实况观测和北京T2 13数值预报资料 ,对 2 0 0 3年 9月 3～ 4日山东雨季最后一场大暴雨过程进行了诊断分析。结果表明 ,本次大暴雨是由在广东登陆的热带气旋倒槽北伸与西风带弱冷空气相结合的产物。伴随登陆热带气旋生成的低空东南急流为暴雨输送了丰富的热量和水汽 ,低层增暖增湿促使层结不稳定加剧 ,而西风带弱冷空气的侵入对暖湿空气具有抬升作用 ,可触发对流发展和不稳定能量释放 ,导致大暴雨产生。鲁中山区西南侧有利地形促使了低层气旋环流的形成 ,对暴雨具有明显的增幅作用 ,是该地区出现暴雨中心的重要原因。

A diagnostic analysis is performed of the last severe storm in the summer of 2003 that occurred during 3～4 September in Shandong Province using observations and Beijing T213 model output data. The results show that the heavy storm was caused by the interaction between a tropical cyclone trough that landed in Guangdong Province and a weak cool front in the westerlies. The southeast low-air jet accompanying the tropical cyclone transported plenty of heat and moisture for the storm, the low-level heating and wetting weakeed the stability of the air, and the weak cool air intruded from the low-level and stimulated the convection, thus leading to the heavy storm. The topographic influences in the southwest of central Shandong are in favor of the formation of the low-level cell, which amplified the rainfall intensity and resulted in the precipitation center there.