Abstract: Using the data from a Doppler weather radar,the sounding data,and 5-min precipitation from meteorological stations in Puer,the evolution characteristics of environmental fields and radar echoes during 41 flash heavy rainfall events from 2015 to 2017 were analyzed.The results showed that mesoscale convergence lines,mesocyclones and adverse wind zones are important causes for the triggering and maintenance of flash heavy rainfall events.Before flash heavy rainfall occurs,the entire atmosphere has abundant water vapor and statically unstable stratification,with precipitable water (PW) ≥ 35 mm,a Showalter index (SI) ≤-0.23,and a K index >35,which can be used as determining factors of the convection potential in the environmental fields.When flashing heavy rainfall occurs,the strongest reflectance factor of radar echoes reaches 40 dBz at least,the echo tops of 35 dBz (RHI35) is larger than 5 km,and the radial velocity of convergence shear variable is larger than 5 m·s^-1.A forecast model for flash heavy rainfall in Puer is established using four influencing factors with significant correlation selected through the multiple linear regression analysis,including RHI35,vertical section center height of 30 dBz,radar echo area more than 30 dBz,and the SI.The validation of this model shows that the relative root mean square (RMS) error of average rainfall intensity is 17.0%,and those of precipitation duration and the amount in local processes are 33.9% and 25.6%,respectively.The forecast error of average rainfall intensity in four flash heavy rainfall events is less than 1.2 mm/5 min,and that for precipitation duration and amount is less than 10 min and 4 mm,respectively.The consistent precipitation exceeds 50 mm for the four events,which is also captured in the model.Overall,the forecast model has good performance and can be used for the short-time forecast of flash heavy rainfall events in Puer area.