Abstract:Atmospheric motion vectors (AMVs) can supply plenty of useful information for numerical weather prediction. With the launch of the Chinese next generation geostationary meteorological satellite FY-4A in December 2016, it is necessary to evaluate the quality of FY-4A AMVs for the analysis field and precipitation forecast by GRAPES of CMA. In this study, by comparing with the background field based on NCEP FNL data, the qualities of FY-4A AMVs were assessed, and the results suggested that the distribution of FY-4A is stable and the quality of FY-4A infrared AMVs is better than FY-4A water vapor AMVs. Based on GRAPES_RAFS, three numerical experiments were conducted to examine the impact on analysis and forecast for severe Typhoon Hato at 0000 UTC 23 August 2017. The findings showed that assimilating FY-4A AMVs, especially FY-4A water vapor AMVs, has certain adjusting effect on wind and height analysis fields. Furthermore, due to the improvement of the initial fields for the model prediction, the performance of the precipitaion forecast was improved. Conclusively, the FY-4A AMVs have positive impact on analysis field and precipitation forecast of GRAPES.