Analysis on the Impact of Typhoon HAITANG on Heilongjiang Province

In August 2017, Heilongjiang Province was affected by the weakening of the typhoon HAITANG, which turned into a low-pressure system northward, causing a heavy rainstorm. The data used in this paper was obtained from the 2.5°×2.5°NCEP reanalysis dataset, conventional observation data and FY-2C2D satellite images. Starting from the large-scale circulation situation, analyze the physical mechanism of the heavy rain in Heilongjiang Province and the characteristics of satellite images. The results show that typhoon HAITANG degenerates into a low pressure system that carries lots of warm and humid air northward, which is combined with the cold air in the north. Heilongjiang Province is affected by the interaction of warm and cold air. The large value area of water vapor convergence overlaps with the center of pressure and moves northeast with it. At the same time, the water vapor convergence gradient is relatively large, which is a good corresponding relationship with the appearance of heavy rainfall areas. The low-level convergent and high-level divergent circulation conditions are conducive to the maintenance of low-level ascending movement and provide favorable conditions for the occurrence of heavy rainstorms. Heavy rainstorms mainly occur in areas where the cloud system is thicker and densely structured, where the upward movement is relatively strong. Key words: Typhoon HAITANG, water vapor convergence, satellite images