Abstract:Using the short time severe rainfall data collected by 125 national automatic weather stations and 3400 regional stations in Yunnan Province, and based on the basic idea of “ingredients”, the analysis of mesoscale characteristics was done by choosing typical short time severe railfall cases from May to October in 2012-2016. Then, five types of short time severe rainfall conceptual models suitable to Yunnan Pro vince were worked out. The results show that the short time severe rainfall in Yunnan concentrates from June to August and there are two obvious peaks a day. The strong dry and cold advection and windy weather at high altitude are important bases to discriminate the upper cold advection category. Cold airs affect Yunnan mainly through two routes. Critical systems for the low level warm advection category are monsoon trough and low pressure at the Bay of Bengal, which mainly affects the central and south areas of Yunnan. The surface front has the feature of baroclinic frontogenesis category. This kind of heavy rain is mainly located in the front of 700 hPa shear and 850 hPa temperature fronts and near the surface front. The quasi barotropic A category short time severe rainfall is mainly influenced by the interaction between the westerly trough and subtropical high. Its precipitation areas are scattered and very difficult to forecast. The quasi barotropic B category is affected by the reduced low pressure after the typhoon landing and peripheral structures, and the severe rainfall is located in the area influenced by the 700 hPa wet tongue, 850 hPa warm ridge and the surface convergence line (usually located in the south area of central Yunnan).