Abstract:The 2002-2007 radar data and observations from Jiangxi were examined statistically to determine the correspondence between surface hail and the three body scatter spike (TBSS). We have discussed its operational use as a large hail (≥19 mm) warning criterion in Jiangxi. The result indicated that TBSS as large hail indicator is of very good application significance. The probability of detection (POD) using the TBSS is 0.818. The false alarm ratio (FAR) is 0.182 for large hail. And the critical success index (CSI) is 0.692. As in the previous studies, the TBSS is an echo region aligned radially downrange from an intense reflectivity core and is usually characterized by low reflectivity and near zero or weak inbound velocities. Spectrum widths are very broad and often noise like. It is found almost exclusively aloft in the mid levels (4-9 km) and then to descend with hail descent. A distinct advantage of the TBSS as a warning criterion is a lead time of up to 77 minutes. The TBSS has various appearances and occurs at different elevation with the distance changing. In brief, the TBSS is an effective large hail criterion.