Abstract:The general atmospheric circulation in the northern hemisphere in autumn (September-November) 2017 is characterized by the dipole polar vortex and 4-wave mid-high latitude westerly belt, which is stronger than that in summer. From September to October, the subtropical high is located abnormally westward with intensity close to normal, tropical cyclones are active, and the westerly belt is straighter without significant ridge and trough. In November, cold air activities are intensified due to the enhanced meridional circulation. In autumn 2017, there are mainly 14 strong winds (above 8-grade) processes in China's inshore areas, including 9 related to cyclones, 11 generated by cold airs, and 7 under the both. There are also 24 rough wave (above 2 m) processes. In this season, there is no thunderstorm induced gale or large-scale sea fog process. In the Northwest Pacific and the South China Sea, there are 11 typhoons, while 18 tropical cyclones occurred in other oceans:9 in the North Atlantic, 7 in the eastern Pacific,and 2 in the India ocean. The sea surface temperature has a overall trend of decrease.