NEXRAD Level II and NEXRAD Level III is a series of digital data sets DSI-6500 through DSI-6899, plus DSI-7000, archived at the National Climatic Data Center (NCDC). The Next Generation Weather Radar system (NEXRAD) comprises over 100 Weather Surveillance Radar-1988 Doppler (WSR-88D) sites throughout the United States and selected overseas locations. This system is a joint effort of the United ... States Departments of Commerce (DOC), Defense (DOD), and Transportation (DOT). The controlling agencies within those departments are, respectively, the National Weather Service (NWS), Air Weather Service (AWS) and Federal Aviation Administration (FAA). Level II data are the three meteorological base data quantities: reflectivity, mean radial velocity, and spectrum width. Level II data are recorded at all NWS and most AWS and FAA WSR-88D sites. From these quantities, computer processing generates numerous meteorological analysis products known as Level III data. Level III products are recorded at most of the sites. In general, non-US sites do not have Level III products, although a few US sites also do not. The data is sent to the NCDC for archiving and dissemination. Data is from June 1991 to present. Significant Level III parameters are: Base reflectivity and velocity at 124 nm and elev. 1; velocity azimuth display (VAD) wind profile; echo tops; vertically integrated liquid; 1-hour precipitation accumulation; storm total precipitation; composite reflectivity at 248 nm, 8-level and 16-level; mean radial velocity at 32 nm; spectrum width and 32 nm, elev. 1 and 123 nm elev. 1; storm structure; signficant weather overlay - hail index, mesocyclone, severe weather probability, storm tracking information, and tornado vortex signature.