华北一次西南涡暴雨过程的诊断分析

摘要

利用一日4次1°×1°的NCEP再分析资料和常规观测资料,分析了2010年7月19日发生在华北地区的西南涡暴雨过程。结果表明：此次暴雨过程是不同尺度系统共同影响的结果,低空急流将水汽源源不断地向暴雨区输送,云水含量大值区与强上升运动和强降水时段有较好的对应关系,高、低空急流的耦合作用促进了上升运动,暴雨期间对流层低层有自南向北发展的高能舌维持,存在对流性不稳定层结,上升运动自低层向上发展,将低层的暖湿空气向上输送,使得大量的不稳定能量释放,为暴雨区提供了持续的能量。%The heavy rainfall caused by the southwest vortex along North China region on 19 July,2010 was analyzed by the NCEP reanalysis daily data and the conventional observation data.The results indicated that the heavy rainfall was the combined result of the systems at different scales.The low-level jet stream transferred the water vapor to the heavy rainfall area continuously,and the area of abundant cloud water content and the strong ascending motion were consistent well with the heavy precipitation period.The coupling of upper and lower jet streams promoted the ascending motion.During the heavy rainfall,there was high energy tongue which developed from south to north in lower troposphere,and the convective instability stratification existed.The ascending motion developed from low layer to high layer and transferred the warm and moist air upward,along with the release of large amount of unstable energy which provided sustained energy for the heavy rainfall.