HYDRO-NEXRAD is being developed as a prototype by researchers from The University of Iowa, Princeton University, UCAR's Unidata Program Center, and the National Climatic Data Center (NCDC), with funding from the National Science Foundation. The formal goal of the project is to provide the science community with ready access to the vast archives and real time information collected by the national network of NEXRAD radars. The emphasis is on providing radar-rainfall data for use in hydrology, hydrometeorology, and water resources.

Unidata plays several important roles in the HYDRO-NEXRAD project. First, Unidata maintains the LDM feed that is the primary source for the NEXRAD Level II data. Second, Unidata hosts the mapserver that is an integral part of the HYDRO-NEXRAD user interface and meta-data generation. Further, Unidata has established the experimental HYDRO feed. This feed is distributed via the IDD, and as the name suggests, is dedicated to hydrology users. At present the HYDRO-NEXRAD client is the only user. However, any IDD user with an LDM setup can subscribe to the feed. The HYDRO feed carries radar-based metadata for all the radars used by HYDRO-NEXRAD. The radar-based metadata are computed at Unidata and then pushed through the IDD. Internally, HYDRO-NEXRAD uses the NEXRAD data in a very space- and I/O efficient format. In addition to the metadata, Unidata performs this conversion and pushes the radar data through the IDD.