A Thunderstorm Identification Method Combining the Area of Graupel Distribution Region and Weather Radar Reflectivity

Abstract

Abstract Thunderstorm identification from weather radar data remains a fundamental problem in lightning nowcasting. In this study, a novel thunderstorm identification method combining the area of graupel distribution region and weather radar reflectivity is proposed. To optimize identification parameters of the identification method, the radar echoes with 312 thunderstorms in 17 weather processes in Nanjing area, China, from 2014 to 2015 were identified and tested to obtain the optimal identification parameters. The results indicate that the optimal parameter combination is to set the storm region identification reflectivity threshold at 0°C isothermal level to 30 dBZ and set the area of graupel distribution region to 2 km2. With such a parameter combination, the optimal identification results with the probability of detection of 91%, false alarm rate of 6.9%, and critical success index of 85.3% could be obtained. Moreover, the proposed thunderstorm identification method can also provide effective means for thunderstorm nowcasting.

Keywords

• thunderstorm identification
• graupel distribution
• weather radar