T he 2002 report “Weather radar technology beyond NEXRAD” from the National Research Council (NRC) identified phased array radar as a can didate technology to replace America’s aging fleet of weather surveillance radars (National Academies 2002). Prompted by the NRC report, the Office of the Federal Coordinator for Meteorology (OFCM) convened a joint action group to investigate user re quirements for this emerging technology. The group’s efforts resulted in the June 2006 report “Federal Research and Development Needs and Priorities for Phased Array Radar” (OFCM 2006). Based on advances in radar technology since the 1980s, the OFCM report recommended con sideration of wholesale replacement of America’s existing weather and aircraft surveillance radar networks with multifunction phased array radar (MPAR) systems. MPAR is a specialized application of general phased array radar technology, designed to simultaneously fulfill the multiple functions of national air and weather surveillance. The basis for this recommendation is as follows: 1) MPAR observa tions will enable improved meteorological forecasts and warnings; 2) major existing radar components and facilities infrastructure are projected to become obsolete; 3) MPAR will become increasingly more affordable, while the cost to maintain the existing radar systems will become increasingly more expen sive; and 4) there is significant potential to greatly reduce overall acquisition and life-cycle costs by combining meteorological and air surveillance func tions into a single system. The OFCM report also laid out a research and development plan of action, culminating in building a full MPAR prototype, to answer questions about capability, concept design, and cost before a final acquisition decision would be made. Under the theme “Leveraging technology to build a next-generation national radar system,” the AFFILIATIONS: Weadon—NOAA/Office of the Federal Coordinator for Meteorology, Silver Spring, Maryland; heinselman—University of Oklahoma, Norman, Oklahoma, and NSSL, Norman, Oklahoma; Forsyth and Kimpel—NSSL, Norman, Oklahoma; Benner and toroK—Federal Aviation Administration, Washington, DC *curreNT AFFILIATION : AvMet Applications Inc., Reston, Virginia cOrreSPONDING AuTHOr: Pamela L. Heinselman, University of Oklahoma, CIMMS, 120 David L. Boren Blvd., Suite 2100, Norman, OK 73072 E-mail: pam.heinselman@noaa.gov