7·13郑州大暴雨成因与可预报性分析

2008年7月13--14日郑州市出现局地大暴雨，24h降雨量达174mm，为1951年以来第二高值。这次大暴雨主要由两个时段的强降水累计而成，具有明显的中尺度特征。通过对常规气象资料分析发现：第一时段的强降水由副热带高压内部产生的局地对流云团加强造成，对流层底层东风气流的加强提供的水汽输送和动力抬升作用，促进了对流发展；新生云团进入潮湿的大气环境中能够得到迅速的发展。针对降水具有的明显中尺度特征，综合分析卫星、雷达、自动站等资料发现：利用新一代天气雷达的组合风廓线拼图可以很好地监测中尺度系统的演变趋势；区域自动站的10min极大风速场上显示，地面中尺度辐合线和郑州附近的气旋中心维持时段，与对流云团影响郑州及强降水时段对应。因此具有中尺度特征的局地强降水，可由雷达、自动站等信息作出短时临近预报。

Causes and Predictability Analysis of ＂7 · 13＂ Heavy Rain in Zhengzhou

A local heavy rain occurred on July 13--14, 2008 in Zhengzhou. The 24 hours rainfall of the heavy rain reached 174 mm, which is in the second after 1951. The heavy rain is composed of the heavy precipitation in two periods, which has the obvious mesoscale characteristics. By using conventional observation data, something is found. The first strong precipitation is caused by strengthening local convective cluster generated in the subtropical high, the vapor transportation and dynamic conditions offered by strengthened easterly flow in bottom of the troposphere air promote the development of convection; new cluster in the humid air environment will be rapidly strengthened and developed. By using comprehensive analysis of satellite data, radar data and automatic weather station data and the obvious mesoscale features of the precipitation, the results show that using the mosaics of combined wind profile of the new generation weather radar, the evolution trend of mesoscale system is monitored; the 10 minutes maximum wind field of local automatic weather station show that the surface mesoscale convergence line and the cyclone centre nearby Zhengzhou correspond to the convective cluster affecting Zhengzhou and the strong precipitation period. So the local heavy rain with the mesoscale characteristics can make short-term weather forecast by tracking the information of radar, automatic weather station and so on.