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An event of continuous rainy weather occurred in Zhejiang Province in February 2019. The characteristics of atmospheric circulation are analyzed based on conventional observed data, FY-2E infrared satellite data, NCEP and ERAInterim reanalysis data. The results show: (1) The polar vortex shrinked near the North Pole in February 2019, which caused positive temperature and southwest wind anomaly at 700 hPa and 850 hPa; the westerly jet on the upper troposphere was norther and stronger than usual. The intensity and location of the jet changed ahead of rainfall. (2) There were two water vapour transport channels during continuous rainy weather, which were from the Tibet Plateau and Bay of Bengal vapour channel, Indo-China Peninsula and northern South China Sea. There will be heavy rain when both water vapour transport channels are strong in Zhejiang Province, and it can be clearly seen from the infrared cloud image. (3) The wet Q Vector convergence area at 700 hPa overlapped with the 0 m·s^-1 longitudinal wind area at 850 hPa corresponded well with heavy rain area. There were large pseudoequivalent potential temperatures and water-vapour flux horizontal gradient in the lower troposphere, water vapour transport belt was under it.