Why tropical cyclones' rainfall surges before landfall

A research team at The Hong Kong University of Science and Technology (HKUST) has analyzed 40 years of data covering about 1,500 tropical cyclones and discovered that average rain rates surge by more than 20% in the 60 hours before landfall. The study is also the first to clearly identify the physical mechanisms behind this increase, showing that rising humidity over coastal areas and enhanced land-sea frictional contrasts strengthen convection, intensifying rainfall ahead of landfall. The results provide valuable insights for improving coastal disaster preparedness and early-warning systems.