Abstract:Using the basic reflectivity factor PPI image data of 47 severe convective cases from 50 S-band Doppler weather radars in the central-eastern region of China from 2016 to 2020, the three-body scatter spike (TBSS) characteristics are analyzed based on the screening of 2626 TBSS samples. The results show that TBSS is most frequently observed at altitudes of 1.5 km and 5 km and at the elevation 2.4°. TBSS is mainly observed in the range from the edge of the radar static cone area to the radar radial distance of 210 km. It reaches its peak at the spot 115 km away from the radar. In the radar polar coordinate system, TBSS appears more in the south than in the north, and more in the west than in the east. It is better to observe TBSS when the angle between the moving direction of the convective storm and the radial direction of the radar is larger than 30°. The TBSS echo strength decreases rapidly to 5 dBz within 0-15 km radially outward from the beginning, and fluctuates in the range of -5 and 10 dBz after 15 km, with more than 70% of the TBSS zone being weak echoes weaker than 25 dBz. 99% of TBSS length is under 40 km, and the patterns of TBSSs with varying lengths follow a normal distribution. No significant correlation is found between the frequency and length of TBSS occurrences and the highest value of the high echo core and the area of the high echo.