2007年7月19日黄淮地区区域性暴雨成因分析

Analysis of the Regional Rainstorm Process between Yellow River and Huaihe River Area on July 19,2007

利用常规资料、T213数值预报产品、卫星云图和NCEP 1°×1°的6 h再分析资料,分析了2007年7月19日河南省黄淮地区区域性暴雨的成因,结果表明:此次区域性暴雨是西伯利亚西部高压脊前不断有冷空气南下,使贝加尔湖切断低压发生替换过程中衍生出许多短波槽携带冷空气南下与南支槽前、副热带高压外围西南暖湿气流大量向北输送汇合产生的;卫星云图直观演示了中尺度对流复合体(MCC)演变特征,而且在其移动过程中激发出的中α、β尺度对流云团造成了短时强降水;云顶亮温tbb最低值中心及强度、sθe高能区可以指示强降水的落区和移动方向;另外,高低空急流耦合形成急流次级环流为中尺度对流云团长时间维持提供了持久、深厚的上升运动。

By using conventional observation data, T213 numerical forecasting products, satellite cloud image and the 1° × 1° NCEP reanalysis data, the cause of the regional rainstorm occurred on July 19, 2007 in Henan Yellow River and Huaihe River Area is analyzed. The result shows the regional rainstorm happened when the unceasing cold air of west Siberia moved south, which made the lake Baikal of cut-off low replace and many short wave troughs grow which carried the cold air to go south, converged the massive southwest warm and wet airflow in the south trough and at the edge of subtropical high. The satellite cloud image direct-viewing demonstrated the evolution characteristic of MCC, which stimulated meso α, β scale convective cloud cluster in motion process and leaded short-time strong precipitation. The minimum value center and intensity of tbb and the high energy region of θse. could instruct the fallen area and moved direction of strong precipitation; moreover, the jet sub-circulation of high-low jet stream coupling provided lasting-deep lifting movement to the mesoscale convective cloud cluster.