2012年7月4—5日河南省驻马店暴雨过程分析

The Process Analysis of Rainstorm in Zhumadian on July 4—5,2012

利用MICAPS常规资料、NECP再分析资料、雷达回波资料,对2012年7月4—5日河南省驻马店暴雨过程进行诊断分析,资料表明:此次暴雨过程是受副热带高压边缘西南气流和中低层切变线的共同影响,高空槽后带来的冷空气与西南暖湿气流在淮河流域上空交汇,促使不稳定能量爆发,从而产生中小尺度强降水.在新一代天气雷达上,则表现为对流性降水回波,回波呈块状结构,强度大,中心强度为59 dBZ,对流高度12 km.从回波连续演变来看,整个回波云系随着低槽的东移南压,移速25 km/h.径向速度图上,最大负速度入流为-39 m/s,最大正速度出流为24 m/s,入流绝对值远大于出流绝对值,表明测站附近为气流辐合.垂直风廓线图上,最大风速高度6.7 km,最大风速风向198 deg,最大风速18.0 m/s,表明高层有西南气流加入,在4.6 km高度附近有一个明显的垂直切变线.

By using the MICAPS routine data,radar echo data,the process diagnosis and analysis of rainstorm in Zhumadian on July 4-5,2012 was carried out. The result shows as follows. The rainstorm process is affected by the edge of subtropical high and low level shear line southwest airflow,and the diffusion of cold air in South Huaihe basin,leads to a burst of unstabile energy,resulting in small scale heavy rainfall. In the new generation weather radar,it showed as precipitation echo with strong blocky structure,center intensity 59 dBZ and convective height 12 km. From the continuous evolution of the echo,echo structures are with low trough eastwards and southwards, moving speed 25 km/h. For radial velocity,the maximum negative speed inflow（Max 39 m/s）,maximum speed outflow （Max 24 m/s）,and the absolute value of inflow is much larger than outflow,which means a flow convergence near the station. For vertical wind profile graph,maximum wind velocity height was 6.7 km;maximum wind velocity and wind direction was 198 deg;maximum wind velocity was 18.0 m/s,showing that southwest airflow joined. Near the height of 4.6 km there was a clear vertical shear line.