Strong convection mechanisms of the Pearl River Delta vary in different weather conditions, and there are some differences in strong convection indexes accordingly. This paper divides the strong convection triggering mechanisms of weather patterns into four sorts: cold air influence, southwest warm moisture flow, impact on the edge of the subtropical anticyclone, and typhoon influence. Outputs of the mesoscale numerical weather prediction (NWP) model of the Guangzhou Institute of Tropic and Marine Meteorology of CMA were used to calculate the thunderstorm environment characteristics, such as water vapor, unstable energy, and dynamic conditions one hour before strong convection, which were selected to verify the convective index thresholds for Pearl River Delta under different synoptic patterns and to establish the corresponding potential forecast system. Through the verification of a typical thunderstorm process and a shorttime strong rainfall case, it is proved that the strong convection potential forecast products provided by the system can indicate the occurrence time and position of strong convection and convective type, which provides a reference for forecasters.