Abstract: With the development of big cities and the requirement of society for refined weather forecast, weather nowcasting, especially nowcasting of sudden disaster weather, has become the focus of social attention. In order to improve the nowcasting ability, the Shenyang Meteorological Bureau has introduced ANC and TRACER system. But due to the short time of practical use, correction technology of the two systems has not been summed up. This paper studied the rainstorm weather processes of October 10, 2013 and August 24, 2014 in Shenyang, summarized the differences of ANC and TRACER in nowcasting, and pointed out that the advantage of ANC was more obvious in local strong convection weather forecast and TRACER was more conducive to the continuous and relatively large range precipitation forecast. This paper could provide correction methods and basis for refined weather forecast in Shenyang with ANC and TRACER.