新乡一次大暴雨过程的强对流特征

Analysis of the Severe Convective Weather Characteristics of a Heavy Rain Process in Xinxiang Area

摘要: 利用常规观测、卫星、多普勒雷达、区域自动站及NCEP FNL再分析资料，对2014年7月29~30日发生在新乡地区的一次大暴雨过程的强对流特征及其成因进行了综合分析。结果表明：此次大暴雨过程是在高空前倾槽、低空切变线、高低空急流、地面扩散南下冷空气及地面辐合线等影响系统的共同作用下产生的，并伴有短时强降水、雷暴大风、龙卷等强对流天气。高空低槽和中低空切变线提供了有利的辐合上升环境场，高低空急流构成了“上干冷、下暖湿”的不稳定层结。低空偏南急流提供了充分的水汽，而地面辐合线是此次强对流天气的重要触发机制。新乡的地形特征也促进了此次强对流的发生发展。多普勒雷达资料对中气旋有较好的指示意义。

Abstract: Using the data of conventional observation, satellite, Doppler radar, regional automatic station and reanalysis data of NCEP FNL, analyzed the severe convective characteristics and their causes of a heavy rainstorm process in Xinxiang area during the 29 - 30 days of July 2014. The results showed that the rainstorm is produced under the common action of upper forward trough, low level shear line, high and low-level jet and surface diffusion southward cold air and surface convergence line etc. affect the system, and are accompanied by a short time strong precipitation, thunderstorm, tornado and other strong convective weather. High altitude low trough and upper-lower shear line provide a favorable convergence ascending field, high and low-level jet constitute the dry and cold, warm and wet the unstable stratification. Low-level southerly jet provided sufficient water vapor, and the surface convergence line is an important trigger mechanism of the strong convective weather. The terrain features of Xinxiang also contributed to the development of the strong convection. Doppler radar data has a good indication to the middle cyclone.