宁夏2次暴雨过程初步诊断分析

暴雨是宁夏主要灾害性天气之一.2002年6月8日,宁夏出现1次区域性暴雨天气过程,其中,贺兰山沿山一带及韦州达到了大暴雨,暴雨过程达到历史同期极值.2006年7月14日,宁夏中北部地区又一次区域性暴雨天气,银川、惠农两站创有气象记录以来日降水量历史同期极值.就2次极值暴雨过程的降水特点、环流形势、主要影响系统、雷达实况分析及常用物理量参数进行对比.对发生在宁夏的2次极值暴雨天气过程的主要触发机制:500 hPa冷槽、700 hPa高原低涡等,并对宁夏暴雨发生起决定性作用的天气系统如:地面锢囚锋、台风位置及强度等进行对比分析.利用常规气象资料和T213数值预报产品以及天气动力学原理进行分析,对2次暴雨天气过程的可能物理成因进行总结.

Preliminary diagnosis and analysis of two rainstorm courses in Ningxia

Rainstorm is one of the major disastrous weather conditions in Ningxia.On June 7 and 8,2002,there appeared a regional rainstorm weather course.During the course,there was heavy rainstorm along Helan Mountain and Weizhou,which reached the extreme record of the daily precipitation in historical records.On July 14,2006,there appeared another heavy rainstorm in the central and north parts of Ningxia,which reached the extreme record of the daily precipitation since the foundation of Yinchuan and Huinong Weather Stations.The two rainstorm courses were analyzed from the point of precipitation characteristics,circumfluence posture,major influence system,actual analysis of radar and usual parameters of physical quantity.The triggering mechanisms of the two extreme rainstorm courses in Ningxia were due to 500hPa cold trough,700 hPa plateau vortex,etc.The decisive weather systems influencing the rainstorms in Ningxia were those such as ground frontal occlusion and typhoon location and intensity,etc.The possible physical causes for the two rainstorm courses were summarized through the analysis by using the usual meteorological data and the numerical forecasting products of T213 as well as the principles of meteorological dynamics.