Analysis of Organizational Modes of Mesoscale Convective Systems Associated with Extreme Precipitation in Shanwei During Annually First Rainy Seasons
LIU Jiajing
WU Zhifang
ZENG Zhilin
CAI Jingjiu
ZHANG Ruqing
PAN Shixian
Abstract：Utilizing weather radar data,observational data from surface stations,and ERA5 reanalysis data from 2013 to 2022,this study analyzed the organizational modes of mesoscale convective systems(MCSs)associated with extremely heavy rainfall events in Shanwei during annually first rainy seasons and their relationship with strong precipitation.The results are as follows.(1)The MCSs can be categorized into four categories:trailing stratiform(TS),back building(BB),broken line(BL),and nonlinear(NL),with some cases exhibiting transitional evolution between different MCS types.(2)Both BB and BL systems moved slowly.BB systems exhibited backward propagation characteristics,while the BL systems were characterized by discontinuous line echoes.TS systems moved at a moderate speed,with strong convective echo bands located ahead of the systems'direction of motion.(3)These MCSs predominantly initiated along the coast from Huizhou to Haifeng between mid-May and early June,with their impact typically starting from nighttime to early morning.The most vigorous development usually occurred from the afternoon to midnight,with BB systems having the longest duration of impact and maturity phase.(4)The maximum hourly rainfall during MCS events was consistently observed in central Haifeng.BL systems produced the most extensive area of intense precipitation.Moreover,BB systems displayed mesoscale vortex features in four cases and tended to result in the strongest short-duration rainfall.(5)All types of MCSs were influenced by either south branch troughs or weak disturbances.TS systems were accompanied by shear lines and frontal systems,while BB and BL systems were associated with warm-sector heavy rainfall events.
Keywords：extreme precipitationorganizational modesclassification and analysismesoscale convective systems(MCSs)Shanwei
Publication Date：2025-02-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 85-98 )