2007年8月8—11日雷州半岛西南部出现了一次特大暴雨,日雨量和时雨量均超出当地历史观测资料的极大值。对本次暴雨过程雨量、日雨量和时雨量进行了特征分析,讨论了热带气旋“帕布”和“蝴蝶”的路径、天气形势、卫星云图和雷达回波的演变与特大暴雨的关系。结果表明:此次特大暴雨具有降水强度大、持续时间长、雨量大、地段集中的特点。前期受“帕布”环流和外围云系影响,雷州半岛普降大到暴雨;后期由于“帕布”路径转向,大气环流调整,受“帕布”环流和外围云系、北部湾低涡云团共同作用,强降水中心长时间维持和摆动。天气形势有利于大量的水汽和能量汇合,南北降水云系、回波相汇雷州半岛西南部,致使出现特大暴雨。
A severe rainstorm occurred in southwest part of Leizhou Peninsula for the period of August 8 to 11,2007, with both daily and hourly rainfalls exceeding the maximum of historical observations. This paper analyzes the characteristics of total, daily and hourly rainfall, discussing the relationships of the heavy rain with paths of tropical cyclones "Pabuk" and "Wutip", weather pattern, variations of satellite cloud images and radar echo, respectively. The results show that this heavy rain is characteristic of high intensity, long duration,large amount and concentrative location. In the early stage, heavy rain occurred in Leizhou Peninsula on account of the effects of the "Pabuk" circulation and its outer region cloud system. In the subsequent stage after the early morning August 10 the track of "Pabuk" turned, the circulation adjusted, and the center of rainstorm sustained and swayed over southwest part of Leizhou Peninsula for a long period of time as a consequence of the interactions of the "Pabuk" circulation,the outer region cloud system and the cold vortex cloud clusters over the Beibu Gulf. Such a weather situation was in favor of the convergence of a huge amount of energy and water vapor, and the southern and northern convective cloud systems and radar echoes meeted in southwest part of Leizhou Peninsula,leading to a severe flood disaster.