甘肃陇南两次不同强度暴雨天气的中尺度特征分析

Mesoscale Analysis on Two Different Intensity Rainstorm Processes in the East of Gansu Province

利用常规观测资料、自动站地面加密观测资料、卫星云图和NCEP 1°×1°再分析资料,分析了2009年7月16-17日发生在甘肃陇南连续两次不同强降水天气过程的中尺度系统——武都涡、中尺度切变线的发生、发展过程,探讨了两次不同强降水天气过程的云图特征和水汽、热力及动力等物理量场差异,提出了这一类暴雨、大暴雨天气过程的预报着眼点和思路。

Using the routine observation data, automic weather station data, the satellite images, NCEP1°×1° reanalysis data, the circulation background of rare, continuous heavy rainstorm weather process in southern Gansu Province in mid-July of 2009 are analyzed, it is important to study the occurrence and de- velopment process of the mesoscale system Wudu vortex and mesoscale shear line in two different time periods, different magnitude rainstorm and heavy rainstorm weather processes in southern Gansu Province on 16--17 July, the cloud image features of two different intensity precipitation processes and the differ- ences of moisture, heat, power and other physical quantity field differences are explored. The result shows that the cold air is one of the important conditions in the heavy rainstorm processes, it makes the Wudu vortex and mesoscale shear line more developing. In the meantime the cold front cloud and the warm cloud merge and form a southwest to northeast cloud band in southern Gansu Province. Several hours of the con- tinuous cloud band causes the heavy rainstorm.