Climatology of NEXRAD Dual-Polarization Radar Moments and Derived Products in Select CONUS Regions

The climatology of dual-polarization radar moments and derived products throughout select regions in the contiguous United States (CONUS) was comprehensively assessed using data produced by the Next Generation Weather Radar (NEXRAD) network and archived by the National Centers for Environmental Information (NCEI) in raw form. An upgrade of the NEXRAD network to polarimetric radar technology, completed by 2013, has made the radar moments differential phase shift (Φ_dp), correlation coefficient (ρ_hv), and differential reflectivity (Z_dr) along with the standard radar reflectivity factor (Z_h) available in the form of volume scans surveying most of the CONUS at time intervals on the order of 10 minutes. From this dataset, Z_h, Z_dr, ρ_hv, a specific differential phase (K_dp) product derived from the phase shift data, and three dimensional rainfall rate and hydrometeor identification products produced by fuzzy logic algorithms incorporating the dual-polarization data were considered. For each volume scan, these were interpolated to a three-dimensional common spherical grid with constant elevations above ground level (AGL), and merged into monthly multivariate histograms. This method was performed over three climatically distinct regions (Pacific Northwest U.S., Central Great Plains, and U.S. Gulf Coast) using data from multiple radar stations covering the period from 2013 to 2014. Basic statistics from the data were then tabulated and compared cross-regionally and seasonally, along with pseudo-color visualizations of grid point-by-grid point statistics for multiple heights AGL. A database of the results will be made digitally available to the public and the scientific community. In future work, scans from all NEXRAD stations within the CONUS will likely be analyzed using the same methods, and the database updated.