Witold F. Krajewski

Hydro-NEXRAD: An Updated Overview and Metadata Analysis

Hydro-NEXRAD is a prototype system that allows hydrologists to obtain userspecified rainfall data for their research. These data are based on observations collected by the national network of WSR-88D radars, known as NEXRAD. Users interact with Hydro-NEXRAD through a web-based interface that has map-based components for spatial navigation, calendar- and time series plot components for temporal navigation and a menu-based component for selection of processing options. Through the interface, users browse the Hydro-NEXRAD metadata and select data of interest. As the system is approaching the point of being fully operational, the authors and a group of test users have evaluated several aspects of the system. Metadata remains very important for the system functionality. Radar-based, basinbased and point (for selected set of rain gauge locations) metadata serve multiple purposes: 1) enable users to efficiently search for subsets of data (SQL query, visual inspection), 2) provide information on quality of the collected data archive (missing or corrupt data), 3) and have a scientific value (basin-based metadata has a potential to be used as a precipitation input to hydrologic models).