鄂尔多斯地区一次暴雨过程卫星云图特征

利用气象卫星云图、MICAPS资料、地面观测资料以及天气学原理等方法,对发生在鄂尔多斯地区一次暴雨天气过程进行分析。结果表明：这次强降水主要是活跃暖锋云系及镶嵌在其底部中γ尺度暴雨云团共同作用的结果;欧亚上空500 hPa为阶梯槽东移与副热带高压西缘北上暖湿气流在河套地区辐合,700 hPa上有切变线,华东地区江淮气旋北部东南风急流向西北方向输送;有3路水汽输送带从西、西南、东南方向向河套地区源源不断输送水汽和能量并汇聚;处于上冷下暖对流不稳定层结;强降水发生在物理量场平流项和散度项配置较好的区域及暖锋云系前方冷锋云带发生断裂的区域。

Characteristics of Satellite Images during a Heavy Rainfall in Ordos

By use of meteorological satellite images,MICAPS data,and conventional observation data,based on the principles and methods of meteorology and the application of weather satellite images to weather analysis and prediction,the process of a heavy rainfall event in Ordos is analyzed.The analysis results indicated： The heavy rainfall was induced mainly by the coactions of an active warm-front cloud system and a middle-γ scale cloud storm nested in the bottom of the cloud cluster.Above the Europe and Asia at 500 hPa there was an eastward-moving stepped westerly trough converging with the northward warm-moist air flow in the Hetao area to the west of the subtropical high.There was a shear line above 700 hPa,and the northern East China southeast wind jet to the north of the Jianghuai cyclone transported water vapor to the northwest.There were three water-vapor transport channels conveying water vapor and energy to the Hetao area from the west,southwest,and southeast,respectively.There was a convective unstable stratification of cold at upper levels and warm at lower level.Heavy rainfall occurred in the front of the warm-front cloud zone in the area of the cold-front cloud band breaking,in combination with the favorable advection and divergence.