Statistical Characteristics of Thunderstorm Activity in the Middle Reaches of the Yangtze River Basin Based on a Five‐Year Cloud‐To‐Ground Lighting Data Set

Abstract

Abstract Using a clustering algorithm based on cloud‐to‐ground (CG) lighting data, 72,974 thunderstorms were identified and tracked in the middle reaches of the Yangtze River Basin from May to September of 2016–2020. Thunderstorms predominantly occur in the southeast region and move to the northeast at a speed of 16–64 km/hr. Most thunderstorms have short durations (98.3%, ≤3 hr) and low CG flash frequencies (90.0%, ≤64). Thunderstorms with longer durations are mainly triggered near the mountains and tend to occur (end) earlier (later) in the afternoon (evening). The peak composite reflectivity (CR) corresponding to CG flashes from all thunderstorms is 50 dBZ. Approximately 70% (20%) of CG flashes occur in convective (stratiform) areas. The first CG flash of a thunderstorm tends to occur in convective areas with a higher CR than that of the last CG flash. The average and maximum CRs of CG flashes increase significantly with thunderstorm duration.

Keywords

• thunderstorm
• cloud‐to‐ground lighting
• statistical characteristics
• cluster method