2018年8月19—20日莱阳一次区域性大暴雨天气过程分析

Analysis of a Regional Rainstorm in Laiyang from August 19 to 20,2018

2018年8月19-20日莱阳市受台风"温比亚"减弱成的低压环流影响,普降暴雨或大暴雨。此次降水过程强度大、范围广,强降水时段小时雨强大且持续时间较长。莱阳市位于台风移动路径的右侧,前期台风倒槽、后期台风本身,正涡度中心逐渐向东北方向移动控制山东半岛,为此次极端降水提供了较好的动力条件。东南-偏南急流的建立和持续为降水提供了充沛的水汽条件,深厚的湿层和上升运动区、良好的水汽供应和较长的持续时间是造成此次极端降水的主要原因。短波槽携带弱冷空气入侵及不稳定能量也为此次极端降水提供了有利条件。

From August 19 to20,2018,Laiyang City was affected by the low-pressure circulation weakened by Typhoon "Wenbia",which caused heavy rain or rainstorm. The precipitation process was of great intensity and wide range,and the hourly rainfall was strong and lasted for a long time during the period of heavy rainfall. Laiyang City was located on the right side of the typhoon’s moving path. In the early stage of typhoon’s reversal,the typhoon itself in the late stage,the center of positive vorticity gradually moved to the northeast to control Shandong Peninsula,which provided a better dynamic condition for this extreme precipitation. The establishment and persistence of the southeast to South jet provided abundant water vapor conditions. The deep wet layer and ascending movement area,good water vapor supply and long duration were the main reasons for this extreme precipitation.The short wave trough carrying weak cold air invasion and unstable energy also provided favorable conditions for this extreme precipitation.