2015年8月3日山东西北部暴雨过程的中尺度特征分析  

Study of mesoscale characteristics of the rainstorm in northwestern Shandong on 3 August 2015

作　　者：高帆[1] 张永婧[1] 李瑞[1] 褚颖佳 GAO Fan ZHANG Yongjing LI Rui CHU Yingjia(Jinan Meteorological Bureau, Jinan 250102, China)

机构地区：[1]济南市气象局,山东济南250102

出　　处：《海洋气象学报》2017年第2期96-101,共6页Journal of Marine Meteorology

基　　金：山东省气象局科研项目济南专项(sdjn2016-04)

摘　　要：2015年8月3日山东西北部出现一次对流性暴雨过程,中尺度特征明显。利用常规和非常规观测资料对该过程的中尺度环境场、对流系统的触发演变及大暴雨的落区进行分析。结果表明:这是一次典型的低槽冷锋暴雨过程。在高层辐散、中层北涡南槽、低层切变线和低空急流的天气背景下,较大的大气可降水量、大的低层比湿、中低层深厚的湿层和暖云层及大的对流有效位能为暴雨的发生提供了有利的环境条件。暴雨由暖区对流和冷锋对流共同造成,暖区对流在地面露点温度大值区内和低层湿舌的南边缘由地面辐合线触发生成,其在聊城形成列车效应,产生大暴雨。地面冷锋侵入低压后暖区对流带与冷锋对流带合并为一条强对流带,且逐渐转向偏东方向移动,列车效应减弱。强对流带后部形成弓形回波,产生地面大风。本次强降水符合热带强降水型特点。强对流带在卫星云图上表现为一个扁平状的中尺度对流系统,小时雨强50 mm以上的区域对应卫星云图上TBB小于-70℃的区域。A convective rainstorm with mesoscale characteristics occurred in northwestern Shandong province on 3 August 2015. Based on both conventional and unconventional observation data, the environmental conditions, initiation, evolution of convective systems, and rainstorm distributions are analyzed in this paper. The results show that this rainstorm event was typically induced by upper-level trough and surface cold front. Under circulations of high level divergence, middle level trough, low level shear line and LLJ, favorable environmental conditions for the rainstorm were composed by large atmospheric precipitable water, high low level specific humidity, deep wet layer and warm clouds in middle and low level, and large CAPE. Warm area convections and cold frontal convections contributed to the rainstorm jointly, while the warm area convections were generated by the surface convergence line, which located in the area of large ground dew point temperature and on the south edge of the low-level wet tongue. In Liaocheng, train effect was formed and further enforced the heavy rainstorm. After the cold front invaded into the low pressure, the cold frontal convections and the warm area convections merged into a strong convection band. The track of the convection band turned to the east gradually, together with the weakening of the train effect. A bow echo formed behind the strong convection band, generating strong winds. The rainstorm has characteristics of tropical heavy rainfall. The strong convection band is shown as a flat mesoscale system on the satellite imagery, and the region, where hourly precipitation equal or greater than 50ram, is corresponded to the area where TBB is lower than -70 ℃.

关 键 词：暴雨 环境条件 暖区对流 列车效应 系统演变 

分 类 号：P458[天文地球—大气科学及气象学]