Abstract:Typhoon and local rainstorm are the primary meteorological disaster in summer fl ood season in Zhejiang. The principal method is based on the primary radar infor mation in the three dimensional variation assimilation for typhoon nowcasting t echnique and research. Automatic echo identification, echo tracking and precipi tation estimation are developed by researching the radar information of last yea rs and modulating the parameter for local. The cross correlation technique and centroid method are used for strong convection echo identification and tracking. The moving direction tendency of the mesoscale convective cloud clusters and th e real time data of auto precipitation station are considered. The dynamic pre cipitation is evaluated by applying the best probability windows to get the mo st suited Z I relationship. Through the retrieved variation correction, the rainstorm nowcasting within 1 hour is made by use of linear extrapolation. Cons idering the requirement of typhoon short time forecast service, the system cont ains the rapid diagnostic analysis for typhoon center and mesoscale circulation pattern based on GBVTD (Ground base Velocity Track Display method). As a workin g platform，the system can be used for disaster weather forecasting and service.