Study on the local rainstorm classification in Yunnan Province

By counting the local rainstorm processes in Yunnan Province from 2011 to 2015, based on conventional observation data and NCEP re-analytical data, we divided and analyzed the cases of different types. The results show that the local rainstorms can be divided into five types, namely peripheral type of subtropical high, two-high convergence type, shear line type, tropical low pressure type and the Bay of Bengal trough type. The occurrence frequency of peripheral type of subtropical high and two-high convergence type is higher; that is to say, under the influence of subtropical high, it is advantageous to produce local rainstorm processes. The satellite cloud image revealed that, an M_βCS causes such rainstorms directly, the M_αCS and stratiform clouds are fewer, and the heavy rainfall areas are located at the edge of the system and occur in the processes of the system mobile development or mobile weakening. The heavy rainfall areas are located in the high value zone of TBB gradient, the TBB reduction takes place 2—3 hours prior to the start of the strong rainfall, and the development of heavy rainfall lags behind the cloud group development.