Analysis of the Characteristics of Regional Heavy Rain Clusters in Shanwei

LIN Pei-xian; CHEN Yin-lan; SU Jing-hua; WU Jing-wei; ZHANG Yi

doi:10.3969/j.issn.1007-6190.2023.06.012

Abstract：To help the forecaster to understand the variation patterns of rain clusters fully,this work i-dentifies the regional heavy rain clusters of Shanwei and analyzes their characteristics.A total of 99 processes of regional heavy rain were selected based on the data of daily rainfall amounts for the period from April to September in 2014 to 2020,and a sum of 310 rain clusters were identified using the OPTICS spatial cluste-ring approach and the characteristics of 134 mesoscale rain clusters were analyzed.The results are shown as follows.(1)Most of the regional heavy rain cases were accompanied with one to three rain clusters,in which one-cluster processes took up the majority.(2)For the regional heavy rain clusters,the zones of high spatial frequency were located in the urban districts of Shanwei,the Hekou Town of Luhe County and the Ji-azi Town of Lufeng City.(3)For the mesoscale rain clusters that affected Shanwai,the life cycle decreased with time,mostly lasting between two and three hours,with the distribution of its spatial frequency consistent with that of the rain cluster.(4)The mesoscale rain cluster was mainly rectangular-shaped,and the fre-quency of observation sites that observed different levels of rainfall intensity all roughly decreased with the in-crease of the number of sites.