CHARACTERISTCS OF LIGHTNING AND RADAR ECHOES AND RELATIONS BETWEEN THEM FOR STRONG CONVECTIVE RAINSTROM IN YUNNAN

By cloud-ground lightning data and Doppler weather radar echo data,the characteristics of lightning and radar echoes and the relations between them for Yunnan strong convective rainstorms are analyzed for 2007 flood season.The results show that most rainstorms belong to convective rainstorms in which lightning is mostly negative and the negative lightning number is more than 90% of the total lightning number.The precipitation and the lightning number are little relativity in the rainstorm's day,but big day-lightning frequency always produces heavy precipitation.Hourly evolution curves of precipitation and lightning frequency have peak-style characteristics and evolution tendencies between them are very coherent in strong rainstorm,but lightning occurrence has always precedence over precipitation.Precipitation peaks are in phase to lightning frequency peaks or fall behind them for about 1～2 hr,and the positive frequency peaks are in phase to the precipitation peaks or falls behind them.Uneven wind field structure on radial velocity is advantaged to convective echo development and lightning occurrence.Lightning which produces strong convective rainstorm is very corresponding to the strong echo field and usually produces in the area where reflectivity is above 30 dBz and Echo Top-ET is above 9 km.