Analysis of the Evolution of Mesoscale System for an Extreme Dragon-boat Rain in Qingquan
Using data from multiple sources and the ERA5 reanalysis,this paper analyzed the process of an extreme and exceptionally heavy rain that took place from June 20 to 21,2022 in Qingyuan.The re-sults are shown as follows.(1)Under the background of diverging flows at 200 hPa,the intense rain of in-terest formed as a low-vortex shear was in the company of a southwesterly jet stream at its front moving gradu-ally across Qingyuan during its eastward travel.(2)Prior to the intense rain,the atmospheric stratification was already highly unstable so that water vapor from the Bay of Bengal and South China Sea kept converging over the city,supplying sufficient amount of water vapor and instability energy for the occurrence of the heavy rain.(3)The intense rain was mainly triggered by a temperature frontal zone and a surface conver-gence line,which resulted from a warm and humid air mass brought about by a cool pool and a low-level jet stream due to earlier rain in Guangxi.The rain was enhanced owing to topographic lifting and funneling effect.(4)The intense rain took place as it was affected successively by two mesoscale convective systems,which was of tropical marine type and with low mass cores.
万方数据
维普
