Recent Development in NOAA/NESDIS Satellite Snowfall Rate Product and Its Applications

A passive microwave over land snowfall rate (SFR) QPE product has been produced operationally at the National Oceanic and Atmospheric Administration (NOAA) since 2012 (Meng et al., 2017). The product utilizes measurements from sounders and imager/sounders (ATMS, AMSU/MHS, GMI, and SSMIS) aboard eight polar-orbiting satellites operated by NOAA, NASA, EUMETSAT, and DMSP. Among them, the ATMS SFR product from NOAA-20 and S-NPP commenced operations in 2019. A new calibration technique was developed in the cal/val study for the ATMS SFR. It relies on both satellite observations and NWP model predictions to reduce the uncertainties caused by the lack of hydrometeor profile information. The ATMS SFR was validated against NOAA NCEP Stage IV radar and gauge combined hourly precipitation estimates and showed significant improvement over previous method with correlation coefficient around 0.7. The SFR product serves as the only passive microwave QPE input to the NOAA NCEP Second-Generation CMORPH (CMORPH2) blended precipitation analysis. Traditionally, satellite blended precipitation data sets either lack snowfall estimates or rely on other data sources such as gauge and model. Studies conducted by the CMORPH team have demonstrated the superior performance of CMORPH2 in winter compared to previous version.