Investigation of Supercells in China :Environmental and Storm Characteristics

Based on the Doppler weather radar data, More than 250 supercell events in China were identified during the ten-year period from 2002 to 2011. Their spatial distribution, seasonal and diurnal variations are given. Using routine sounding and surface observational data, several important parameters representing the major features of the environment in which these supercells occurred were investigated, and these parameters include convective available potential energy (CAPE), 0-6km deep layer vertical wind shear, 700-500hPa temperature difference, and surface dewpoints. The results show that the value ranges corresponding to the peak frequencies for the CAPE and the 0-6km wind vector difference distributions are from 1000 j/kg to 1500 j/kg and from 20m/s to 25m/s, respectively. With the base data from more than 50 Doppler weather radars, the characteristics describing the intensity, structure, and evolution of Chinafs supercells were analyzed. The average diameter of mesocyclones associated with supercells is 6.2 km, with the range of the peak frequency for diameter distribution being between 4km and 6km. The value ranges corresponding to peak frequencies for mesocyclone rotational speed and duration are from 15 to 20m/s and 40 to 50 minutes, respectively. Over 85% of supercells display the BWER structure, and the value range of peak frequency for supercell maximum reflectivity distribution is between 65 dBz and 70dBzCwith the extreme reflectivity value over 75dBz. dBz.