According to Shao Sun, a climatologist at the University of California, Irvine,” storms that move far upstream affect areas previously less exposed to heavy rain and strong wind, frequently with lower crisis endurance, leading to more severe loss.”
” In this case of Shenzhen, the catastrophe was primarily caused by the slow westward action of Haikui’s residual airflow, which nearly stagnated in its geographical position from the late September 7 to the early September 8 and a” coach effect” of heavy rainfall occurred, causing the event to reach its expected intensity.”
The cumulative impact of numerous convective cloud systems passing over an area successively is referred to as the” train effect ,” which significantly increases rainfall deposition and increases the likelihood of heavy or even extreme rain.