“…Satellite observations play a very important role in improving the accuracy of numerical weather prediction, especially over areas with sparse conventional observations [e.g., McNally et al ., ; Zapotocny et al ., ; Xu et al ., ]; thus, the satellite observation is the key for improving TC forecasts. Recently, microwave satellite observations have contributed the most to improving numerical weather forecasts; the observations have been (or are being) ingested into DA systems [e.g., Smith et al ., ; Goodrum et al ., ; Li and Liu , ; Liu et al ., ; Schwartz et al ., ; Newman et al ., ; Shen et al ., ]. Examples include the Suomi National Polar‐orbiting Partnership (NPP)‐Advanced Technology Microwave Sounder (ATMS) data, used in the European Centre for Medium‐Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) systems (NIELS) [ Niels et al , ; Collard et al ., ]; the NOAA‐18 and MetOp‐A Microwave Humidity Sounders (MHSs), used in the Weather Research and Forecasting DA system (WRFDA) [ Schwartz et al ., ; Newman et al ., ] as well as most operational centers [ Thépaut , ]; and the FY‐3A and FY‐3B MWHSs, used in the ECMWF system, which is the first operational use of Chinese polar orbiter satellite data by an NWP center outside China [ Lu et al ., a; Chen et al ., ].Notably, the MHS and MWHS are designed to retrieve profiles of atmospheric water vapor.…”