Abstract:Based on NCEP FNL (1°×1°) reanalysis data, observation data from automatic weather stations in Jiangsu Province and new generation weather radar data in Yangtze River Delta area, the cyclone phase space (CPS) method was used to analyze the phase space parameters of typhoons that occurred in Jiangsu from 2000 to 2015. The results show that the CPS method could objectively and accurately describe the transition process of typhoons in Jiangsu affected by various paths according to Typhoon Almanac (CMA-STI). Typhoons affecting the transition of typhoons in Jiangsu are mostly landing northward and show strong intensities before the transition. We further analyze phase space parameters of “Haikui” and “Matmo” with different CPS trajectories. The results show that the phase space parameter can better reflect the evolution of the thermal structure and circulation characteristics during the transition process of typhoon, and it is related to the location and intensity of typhoon precipitation. “Haikui” with obvious changes of CPS parameter has significant variations in the location and intensity of typhoon precipitation. “Matmo” with small CPS parameter changing basically has rains around the typhoon itself.