Analysis on Radar Echo Characteristics of a Rare Large Hail Event in Jiangxi Province

Dong Ling; Zheng Jingguang; Chen Baofa

doi:10.16765/j.cnki.1673-7148.2025.01.005

Abstract：The monitoring and early warning of hail weather has always been a key and difficult point for the forecasting services of meteorological stations.In order to better monitor and forecast hail weather,this paper uses the meteorological data,Jiangxi radar mosaics,and PUP products as well as the synoptic meteorology,radar meteorology principles and analysis methods to analyze the radar echo fea-tures of the rare large hail weather process in Jiangxi from March 30 to 31,2021.The results indicate that:(1)On the 30th,a supercell echo system was generated within the territory of Hunan Province,went through a process of merging,developing and splitting,and formed a"right-shifting"supercell storm deviating from the 500 hPa high-level wind direction,and the echo maintained for 3-4 hours.On the 31st,there were five supercell echo systems generated,three within the territory of Hunan Province and two within Tonggu and Yifeng,and the echoes lasted for less than 2 hours.(2)When the echoes show the characteristics of"strong echo in the south and weak echo in the north",it means that the echo may split and form right-shifting and left-shifting echo cells.The CR intensity of the right-shifting echo reached 70 dBZ,and large hail occurred,but the left-shifting echo gradually weakened.(3)The super-cell echo on the 30th had typical echo features of a 70 dBZ strong echo core,a large 60 dBZ strong echo area,a large gradient between 30-60 dBZ strong echoes,and a forward-extending weak echo formed by cloud anvils.At the peak of supercell strength,a"shield-shaped"ultra strong echo structure was formed.(4)On the 31st,the supercell echo system occurred on the squall line echo belt,known as"band supercell",with weaker echo intensity than isolated super cells.Sometimes there were two or more band supercells,and all of them could incur hail weather.(5)The composite reflectivity CR of the supercell echoes reached 65 dBZ,the vertical integrated liquid water content(VIL)reached 60 kg/m2,the top height of RCS strong echo(≥60 dBZ)in vertical profile of reflectivity factor was 10-11 km,the echo center strength reached 65 dBZ,and the super cell was suspended at a height of 6-8 km.The echo had wall,suspension,dome and other structures.The vertical profile of radial velocity VCS had a meso-cyclone structure,with a velocity shear value being-19-27 m/s.