辽宁一次短时大暴雨过程中暴雨预警信号的发布及其成因分析

为提高短时暴雨预警发布质量，更好地发挥预警信号在防灾减灾当中的作用，笔者对2014年7月15日辽宁发生的一次局地短时大暴雨过程中暴雨预警信号的发布情况进行了分析。结果表明：此次短时大暴雨过程中，在精确到乡镇的前提下，辽宁省的暴雨预警信号准确率达83.3%，平均提前量为 37 min。但暴雨红色、橙色提前时间较短，分别为10 min和20 min。值班预报员应在正确理解预警信号发布规定的基础上灵活处理，把握预警信号最佳发布时机，做好预报服务工作。此外，通过对过程的成因进行分析发现，此次暴雨中小尺度特征明显，具有突发性强、雨强大等特点，大尺度天气系统上不易分析出来，位势不稳定、东南与西南低空急流交汇是其主要成因。

Rainstorms Warning and Cause Analysis of a Short-time Torrential Rain in Liaoning Province

The paper aims to improve the quality of short-time rainstorm early warning, and to exert the role of early warning signal in disaster prevention and mitigation. The release condition of rainstorm warning signal for a local short-time rainstorm on July 15, 2014 in Liaoning Province was analyzed. During this short-time rainstorm process, the rainstorm warning signal accuracy in Liaoning Province was 83.3% on the premise of accuracy on village and township level, and the schedule advanced 37 min on average. But the time of red and orange signal for heavy rain was shortly ahead, respectively for 10 min and 20 min. Forecasters on duty should deal with the rainstorm warning flexibly based on correct understanding of the early warning signal issuing rules, and seize the best opportunity for releasing rainstorm warning signal and provide a good forecast service. Besides, through the analysis of the cause of the rainstorm process, this rainfall had smaller scale feature obviously, and appeared more suddenly and powerfully. But, it was not easy to analyze on large scale weather system, for the potential instability, and the southeast and southwest low level jet were the main causes of the rainstorm.