台风“利奇马”背景下的山东一次暴雨天气过程分析
Analysis of a Rainstorm Weather Process in Shandong under the Background of Typhoon “Lekima”

本文基于NCEP再分析资料、地面常规观测资料、FY-2G卫星资料、台风最佳路线数据对济南章丘区2019年8月10日至11日暴雨天气过程进行诊断分析。结果表明：暴雨期间章丘始终高空槽前部及低层强盛的东南风急流带控制，且暴雨落区、降水量突增发生时间与台风利奇马移动及偏南大风带的位置配合较好。暴雨天气水汽来源主要为台风外围气流引导，主要来源于渤海区域，强水汽输送及水汽辐合使得暴雨前高层至地面均处于高湿状态，说明良好的水汽输送、水汽辐合累积是本次暴雨发生的原因之一。天气过程发生期间济南章丘处于高层至低层强辐合气流配置中，强降水区存在的正涡度区伴随强烈的上升运动、低层辐合、高层辐散的结构为此次暴雨天气提供了有利的动力条件。其中散度最大值出现的时间较降水峰值出现的时间提前了12小时左右，因此对散度的分析，对本次暴雨的预报一定的提前量及指示意义。暴雨云团具有MSC特征，强降水区域与TBB低值中心对应较好，同时TBB低值出现时段与强降雨时段基本吻合，且对不稳定能量分析可知，本次强降水期间各项对流天气指标参数均反映出济南章丘地区大气出处于弱对流状态。
Based on NCEP reanalysis data, ground conventional observation data, FY-2G satellite data and ty-phoon best track data, this paper diagnoses and analyzes the rainstorm weather process from August 10 to 11, 2019 in Zhangqiu District of Jinan. The results show that during the rainstorm, Zhangqiu is always controlled by the front of the upper trough and the strong southeasterly jet belt in the lower level, and the rainstorm area and the time of the sudden increase of precipitation are well matched with the movement of typhoon Lekima and the position of the southerly wind belt. The water vapor source of the rainstorm weather is mainly guided by the airflow outside the typhoon, mainly from the Bohai Sea region. The strong water vapor transport and water vapor convergence make the high-level to the ground in a high-humidity state before the rainstorm, indicat-ing that good water vapor transport and water vapor convergence accumulation is one of the causes of this rainstorm. During the weather process, Zhangqiu in Jinan was in the configuration of high-level to low-level strong convergence airflow. The positive vorticity area in the strong precipi-tation area was accompanied by strong ascending motion, low-level convergence and high-level divergence, which provided favorable dynamic conditions for the rainstorm weather. Among them, the time when the maximum value of divergence appeared was about 12 hours earlier than the time when the peak value of precipitation appeared. Therefore, the analysis of divergence has cer-tain advance and indicative significance for the forecast of this rainstorm. The rainstorm cloud cluster has MSC characteristics, and the heavy precipitation area corresponds well to the low value center of TBB. At the same time, the time period of TBB low value is basically consistent with the heavy precipitation period, and the analysis of unstable energy shows that the convective weather index parameters during this heavy precipitation period reflect that the atmospheric outflow in Zhangqiu area of Jinan