Analysis of three supercell storms with Doppler weather radar data

Three supercell storms on 24 June 2004(0624), 28 June 2003(0628), 27 September 2002(0927) produced different damages in Shandong province respectively, the scale and weather phenomena of storm 0927 were inferior to storms 0628 and 0624. The inner structure and evolvement of the three storms were analyzed in details based on the CINRAD/SA radar data in the combination with weather charts. The results show that surface meso-scale convergence triggered release of unstable energy, which brought about severe convection. There were different evolvement characteristics on storm development stages, storms 0927, 0628 and 0624 displayed multi-cell propagation, single-cell evolution, and multi-cells mergence, respectively. The storm tracks were similar each other, they were right moving supercell storms, i.e. moved at an angle of 30°-70° to the right of the mean wind, at a speed of about 45%-70% of the mean wind speed. In the mature stage, the maximum reflectivity height was at low level in storm 0927, middle level in storm 0628, and middle-upper level in storm 0624, respectively. Three storms possessed almost all typical features of supercell storms: WER, BWER, and mesocyclone. An organized mesocyclone began at the middle height of an updraft, it deepened gradually downwards and upwards, and became a typical mid-level mesocyclone with strong updrafts. The signatures of the vertical structure of airflows in three storms were similar, i.e. significant convergence at low-level, nearly pure rotation at mid-level, and divergent rotation at upper-level. However, signatures of mid-level horizontal airflows in three storms were different: at mid-level there was a single vortex in storm 0628, and a double-vortex flow pattern in storms 0927 and 0624. The horizontal structure of double-vortex flow pattern is hard to be blown away by environmental airflow, thus the storm could resist for a longer time-period relative to single vortex storm.