【摘要】 从环流形势、单站气象要素及中尺度滤波分析等几方面对2004年7月28日新乡市大暴雨过程进行分析,结果表明:这次暴雨、大暴雨天气过程是副热带高压西伸北抬和西风槽东移及北方南下冷空气的共同影响造成的,副高西伸北抬的“突变”过程,是造成大暴雨的直接原因;中低层切变线的生成,为强对流天气的产生提供了动力条件;低空西南急流不仅输送暖湿空气,增强层结的不稳定性,而且可以产生低层扰动,触发不稳定能量的释放,新乡地区东南部位于深厚急流区入口处的左侧,是暴雨、大暴雨产生的关键部位;用T213的初始流场经滤波分析后,能清晰显示出形成大暴雨的中尺度辐合系统,对暴雨、大暴雨预报有一定的指示意义。更多还原

【Abstract】 Utilizing circulation pattern、single station meteorological elements and meso-scale filtering analysis data and so on,the process of the Heavy rainstorm in July 28,2004 over Xinxiang was Analyzed,and the analysis results indicate that the subtropical high’s west extension and north lifting 、east movement of the westerly trough and cool air from the north work together and form the process of the rainstorm and heavy rainstorm.The direct reason for the heavy rainstorm is the catastrophe process of the subtropical high’s west extension and north lifting;The forming of the medium and minimum altitude shear line provides dynamical condition for the formation of the severe convection weather;Minimum altitude southwest jet flow not only transports warm and wet air,strengthens the instability of the stratification,but also causes low layer disturbance,touches off the release of the instable energy.The southeast of Xinxiang is located at the left of the entrance of the profound jet flow,and is the pivotal position of the forming of the rainstorm and heavy rainstorm.Using the initial current field of T213 and through analysis,the meso-scale convergence system forming the heavy rainstorm can be revealed obviously,which has indicatory meaning to forecast rainstorm and heavy rainstorm.更多还原