Inter-Comparison and Validation of NOAA-Unique Combined Atmospheric Processing System Water Vapor Retrievals and Case Study on Howard University Beltsville Site State Best Estimate

S-NPP NOAA-Unique Combined Atmospheric Processing System (NUCAPS) is a retrieval data product of the NPP satellite, which was designed to provide higher resolution of water vapor and temperature retrievals than its predecessor water vapor satellites for improved weather forecasting. We have launched dedicated radiosondes at Beltsville, Maryland from 2012 to present to validate the NUCAPS water vapor retrieval. Here we show water vapor profile intercomparison results of collocated NUCAPS single water vapor retrieval profile, radiosonde water vapor mixing ratio (WVMR) and lidar WVMR. We also introduce a method to select a single satellite retrieval profile using the atmospheric variability of water vapor determined by a lidar for site state best estimate.  We have found that the satellite single retrieval collocated at the Beltsville site are within a 20% agreement of the radiosonde for water vapor mixing ratio values above 3 g/kg in the lower troposphere and have biases for dry atmospheric conditions from 2012 to 2014.