Abstract:Significant tornadoes associated with supercells can cause severe disasters, but issuing tornado warnings is challenging. Therefore, it is essential to study the detailed echo structure of supercells. Based on the observations of S-band Doppler polarimetric radar, 9 significant tornadic supercells are compared with 9 non-tornaic supercells. The results demonstrate the significant differences between them. The detailed results are as follows. In significant tornadic supercells, the differential reflectivity ZDR arc extends toward the hook echo, and the area of hail in the mid-to-low levels is smaller than in non-tornadic supercells. The average separation distance between the specific differential phase KDP foot centroid and ZDR arc centroid in low level is much larger in tornadic supercells than in non-tornadic supercells. In significant tornadic supercells, the low-level mesocyclone intensifies markedly. Additionally, 24 min and 6 min before the tornado occurs, the mid-level mesocyclone core remains at relatively low heights, averaged at the height of 4.2 km and 3.1 km, respectively. The aforementioned differences require further confirmation of more cases so as to provide additional evidence for in-depth research on the relationship between the echo structure characteristics of supercells and the mechanisms of tornado formation.