西风槽是诱发豫西北雷雨大风和暴雨等强对流天气的一种重要的天气系统。利用常规高空、地面观测和探空资料,对2001-2015年6-9月受西风槽影响在豫西北发生的区域性强对流天气过程的分析发现,由于近地面暖湿空气势力和侵入冷空气的强弱不同,致使天气系统配置差异显著。根据不同天气系统配置,将由西风槽入侵引起的强对流天气过程分为斜压锋生类和低层暖平流强迫抬升类两种。斜压锋生类的显著特征是配合高空槽的移近,影响系统在700 h Pa上有明显的冷槽,在近地面层有明显的锋生和锋面移近,锋面逼近使抬升运动增强是强对流天气启动的重要因素;低层暖平流强迫类的影响系统在700 h Pa上有位势高度槽而无冷槽,槽的南段紧贴或者落后于500 h Pa槽线,呈前倾结构,强的热力不稳定和深层垂直风切变所形成的动力不稳定是引发这类强对流天气的主要因素,地面辐合线、干线触发了强对流天气。二者在物理量场分布上也有着显著的异同:相同之处在于两类强对流天气均有较强的位势不稳定且积累了大量的不稳定能量,两类强对流过程的0℃层均接近或超过5km。不同之处主要有以下几点:1)斜压锋生类中低层湿度更大,湿层更厚。2)低层暖平流强迫类850-500 h Pa的...
【英文摘要】
Westerly trough is an important weather system to induce severe weather like thunderstorm gale,heavy rainstorm,etc. in northwest Henan. By using conventional high and surface observation data,sounding data,the severe convective weather cases from June to September during 2001-2015,influenced by the westerly trough in northwest Henan were analyzed. The results showed that there were significant differences in the synoptic system configuration as the intensity of warm air forces near ground were different wit...