Philippine archipelago and South China Sea monsoon plus ocean cooling buffer Northwestern Pacific super typhoons.

In dramatic contrast to the continuous intensification of strong Atlantic hurricanes moving into the Gulf of Mexico, super typhoons (SuperTYs) originating from the Northwest Pacific significantly weaken after entering the South China Sea (SCS). Using an idealized cyclone intensity model, we show that this striking discrepancy results from the SCS's buffering effects, including persistent topographic blocking by the Philippine archipelago and seasonally shifting atmospheric-oceanic constraints. The archipelago accounts for 54% of typhoon weakening throughout the season, while environmental factors explain the remaining ~46% with the significant seasonal dependence on strong SCS monsoon-induced vertical wind shear in summer (30%) and ocean cooling in autumn (~37%). The Coupled Model Intercomparison Project Phase 6 projects that these buffering effects may likely persist through the 21st century. These findings enhance our understanding of the SCS coastal vulnerability to typhoon impacts, with broader implications for climate risk management.