Impact of Assimilating FY-3D MWTS-2 Upper Air Sounding Data on Forecasting Typhoon Lekima (2019)

In this study, the Fengyun-3D (FY-3D) clear-sky microwave temperature sounder-2 (MWTS-2) radiances were directly assimilated in regional mesoscale Weather Research and Forecasting (WRF) model using Gridpoint Statistical Interpolation (GSI) data assimilation system. The experiments conducted to compare track errors of typhoon Lekima from uses Advanced Microwave Sounding Unit-A (AMSU-A) (EXP_AD) with those FY-3D MWTS-2 upper-air sounding at channels 5–7 (EXP_AMD). mean bias-corrected observation-minus-background (O-B) values 5, 6, 7 are 0.27, 0.10 0.57 K, respectively, which smaller than without bias corrections. Compared control experiment, was forecast WRF use satellite data, can improve performance reduce error by 8.7% (~18.4 km) 30% (~58.6 beyond 36 h through EXP_AD EXP_AMD, respectively. direction simulated steering flow changed southwest southeast be pivotal forecasting landfall (2019) three days advance. Assimilation upper-troposphere has great potential forecasts for Lekima.