Analysis of Radar Echo Characteristics of a Severe Rain Process in May of 2010 in Central Hunan

By using the conventional observation data,automatic weather station observational data and radar echo data the regional severe rain occurred from May 5 to 6,2010 in the Central Hunan is analyzed.The results show that unstable energy increased.K index and Showalter index had certain directive significance before the rainstorm occurred.Both the southeastern jet established and the heavy precipitation occurred almost happened simultaneously.Radar data indicated that heavy rainfall occurred in the wind convergence zone,The ground convergence line moved in the same direction as the shear line of middle and low level,and the their locations were very closed,which provided dynamic conditions for the occurrence of strong convection.Strong echo band contains supercell storm and multicell storm.In this process,meso-scale meteorological stations hourly cyclonic(anticyclonic) flow and negative allobaric center had a better corresponding relationship to both of the rainfall area and move direction of the subsequent regional severe rain,which had good indication to the occurrence and warning of short-time heavy rain.