Abstract:The main characteristics of the general atmospheric circulation of the Northern Hemisphere in spring 2024 (from March to May) are as follows. The polar vortex is characterized by a unipole pattern with its center clearly biased towards the Eastern Hemisphere side and its intensity equivalent to the historical average. The circulation in the middle and high latitudes presents a 4-wave pattern. The cold air affecting China is obviously weaker than usual, resulting in less gale processes. There are 4 gale processes above Beaufort wind force scale 8, including three processes produced by cold air and combined action of cold air and offshore cyclones/typhoons, and one process produced by offshore extratropical cyclones, which is accompanied with extreme gale caused by the development of severe convective system in the bottom of cold vortex. There are 10 obvious sea fog processes, including 7 in March, two in April, and one in May. Moreover, most of the sea fog processes are triggered by the southward warm and moist air current in front of low pressure or behind of high pressure. There are 12 rough sea wave processes with the wave height above 2.0 m in offshore China, the maximum wave height is 3.0-4.0 m, and the wave height above 4.0 m does not appear. The sea surface temperature shows a gradual upward trend, and the sea surface temperature gradient from the East China Sea to the Taiwan Strait is relatively high. There are a total of 11 tropical cyclones formed worldwide, three of which are in the Northern Hemisphere (two in western North Pacific and one in the northern Indian Ocean) and 8 are in the Southern Hemisphere (4 in the southwestern Indian Ocean and 4 in the waters near Australia).