Modulation of Warm‐Season Heavy Precipitation Microphysics by Synoptic Patterns in the Yangtze‐Huaihe River Basin: Insights From GPM‐DPR and Principal Component Classification

Abstract The microphysical characteristics of warm‐season (April to September) heavy precipitation with respect to synoptic patterns in the Yangtze–Huaihe River Basin of China are investigated using 10 years (2014–2023) of dual‐frequency precipitation radar onboard satellite observations and principal component analysis in T‐mode classification. A total of six synoptic patterns have been identified, including the three most prevalent monsoon‐related types (T1, T2, and T3), which contributing 87% of the heavy precipitation hours. Under persistent monsoonal moisture transport in these monsoon patterns, moderate convection and warm‐rain dominance gives rise to homogeneous microphysical features characterized by high concentrations of small‐to‐medium raindrops. The perturbed synoptic patterns, including cold vortex (T4), typhoon‐influenced (T5), and weak disturbance types (T6), collectively account for 13% of events. Among them, T4 and T6 exhibit stronger convective activity, which serves to intensify ice‐phase processes, thereby producing larger raindrops with low concentration. Conversely, the substantial amount of moisture induced by typhoon flows in T5 enhances warm‐rain processes, maximizing the concentration of small raindrops. Despite these modest differences, all patterns exhibit maritime‐like microphysics with warm‐rain processes being generally dominant. Environmental analysis reveals that moisture supply and convective intensity are two major factors that regulate regional heavy precipitation microphysics through their impact on warm‐rain and ice‐phase processes at different layers. This study highlights the critical role of large‐scale circulation in shaping regional precipitation microphysics, providing observational benchmarks for comprehending precipitation extremes and model parameterization.