2026年6月大气环流和天气分析OA

In June 2026,the polar vortex in the Northern Hemisphere exhibited a dipole distribution with the primary vortex located over the Arctic Ocean near the pole,showing stronger-than-normal intensity.The Eurasian mid-high latitudes featured a two-trough and one-ridge circulation pattern,and the average geopotential height ridge from West Siberia to northern Xinjiang was abnormally strong.The western Pacific subtropical high was zonally distributed,with greater intensity and a more westward and northward position than normal.The national average temperature was 20.7℃,0.3℃ higher than the normal value.The national average precipitation was 99 mm,3.7％below the climatological average.However,cold vortices behaved actively in North China and Northeast China resulting in frequent convective activities.In southern China,heavy precipitation processes occurred frequently,with highly overlapping affected-areas and locally extreme precipitation.During this month,there were five heavy precipitation events and six se-vere convection events.Regions such as the middle and lower reaches of the Yangtze River,South China,and eastern Southwest China experienced regional heavy precipitation and local extreme precipitation.Thunderstorm,gale and hail events occurred more in Northeast China,North China and the Huanghuai Region.Two typhoons were generated over the western North Pacific and the South China Sea,but neither made landfall in China.In addition,this paper briefly analyzes the evolution of circulation patterns,causes and forecasting difficulties of the extreme precipitation in South China from 14 to 18 June and the first spell of heavy precipitation in the Meiyu season over the middle and lower reaches of the Yangtze River from 19 to 22 June.