Budgets of rotational and divergent kinetic energy in the warm-sector torrential rains over South China: a case study

Abstract The contributions of divergent and rotational wind components to the kinetic energy budget during a record-breaking rainstorm on 7 May 2017 over South China are examined. This warm-sector extreme precipitation caused historical maximum 382.6 mm accumulated rainfall in 3 h Pearl River Delta (PRD) regions China. Results show that there was high low-level southerly wind-speed tongue stretching into PRD from northeast Sea (SCS) this precipitation. velocity potential exhibited low-value center as well divergence-center SCS. (KR)-related terms were main contribution-terms budget. KR component (KD) barotropical baroclinic processes-related due cross-contour flow vertical flux divergence.