National Weather Service United States Department of Commerce

What is National Level II (NL2)?

The National Level II (NL2) system is a series of servers gathering weather data from NOAA's Doppler Weather Radar (NEXRAD), the Supplemental Product Generator (SPG), and the NOAA Profiler Network (NPN) systems. The data are relayed and forwarded to users in the government and public sectors.

The NL2 system is comprised of two sets of geographically diverse servers. The NL2 objective is to present a robust data delivery solution that is designed to provide continuity of operation in the face of various disaster recovery scenarios.

In addition to the weather data transmission portion of the system, NL2 contains a weather radar system monitor. It monitors the health and dataflow of each radar by extracting the metadata in the existing radar data stream from any given radar site.

These pages do not provide meteorological information for weather analysis.

The Level II data are sent to the National Centers for Environmental Information (NCEI) by the NWS WSR-88D National Level II (NL2) system. Level II data are continuously transmitted and archived from all DOC, DoD and DOT WSR-88D systems and are available via FTP download (http://www.ncdc.noaa.gov/nexradinv/choosesite.jsp). The interface control document describing the Level II format (ICD For Archive II/User) is available at: https://www.roc.noaa.gov/WSR88D/BuildInfo/Files.aspx