Fusion of 3D high temporal and spatial resolution wind field and its application in nowcasting of severe convective weather

The Rapid-refresh Multi-scale Analysis and Prediction System-Integration (RMAPS-IN) is used in this study to merge the nowcasting three dimensional high spatial and temporal resolution wind field from Variational Doppler Radar Analysis System (VDRAS) with the wind field observed at automatic stations. The results show that the analysis results can obviously improve the wind field.(1)The long time series objective test results show that the absolute errors of U/V components are 0.05 and 0.06 m/s, respectively; the absolute errors of U/V components increase with the forecast lead time for the 10 m ground wind field.(2)For the cases of strong convection, the root mean square errors of the 10 m ground wind speed and wind direction are respectively reduced by 0.3 m/s and 13°, and the root mean square errors of wind speed and wind direction are respectively reduced by 0.8 m/s and 10° for the 3-D high resolution wind field. The wind speed and wind direction have been greatly improved in plain sites and the improvements are relatively small in mountain sites.(3)A detailed analysis of the rainstorm occurred on 20 July 2017 and the thunderstorm gale occurred on 7 July 2017 is given. The results show that the RMAPS-IN wind field fusion products can provide more detailed and quantitative description of meso-scale systems.