摘要：The research on the characteristics of low-latitude plateau rainstorm is the current hot spot of meteorological research.Therefore,in this paper,we take China's Yunnan Province as the research object,and systematically carry out the diagnosis study of the duration of heavy rainstorms in low-latitude plateau areas.Yunnan belongs to the subtropical plateau area,with sufficient rainfall and distinct dry and wet seasons.The vertical change of temperature with the topography is particularly significant.Through the analysis of the geographical and climatic characteristics,combined with the research on the background of the influence of atmospheric circulation on the heavy rain in Yunnan,the duration of heavy rains in Yunnan in multiple time periods in 2019 is analyzed.Under the interaction of the East Asian cold trough and the south branch trough,and under the influence of the subtropical high in the western Pacific and the south branch trough continues to move southward,a water vapor channel is formed from the Bay of Bengal to southwestern Yunnan.The mesoscale low pressure is affected by the strong cold air,which promotes the development of convection,and strengthens the tropical mesoscale cyclones and causes the instability of convection.Combined with the complex topography of Yunnan,it has resulted in longterm continuous heavy rain in Yunnan.Finally,through the test of the rainfall from 0:00 on July 28 to 12:00 on July 31,the results show that the rainfall during this period is mainly concentrated from 0:00 on July 29 to 12:00 on July 30.The amount of precipitation changes from high to low,and the rainfall in some areas has exceeded 13mm,which lasts for a long time.
