Identifying critical strengths and limitations of current radar systems

Current weather radars are nearing the end of their expected 20-year engineering design lifetime. One replacement system currently under consideration is multifunction phased array radar (MPAR). The purpose of this study is to illustrate the critical strengths and weaknesses of current radar systems to decision-makers and to determine the suitability of MPAR to users' needs. The study focuses on two key stakeholder groups: National Weather Service (NWS) forecasters and broadcast meteorologists. Interviews are conducted with a variety of radar users from these groups, including Science and Operations Officers (SOOs), Warning Coordination Meteorologists (WCMs), and chief broadcast meteorologists. During the interview, participants are asked to tell stories which exemplify the critical strengths and limitations of current radar technology. Nine interviews have been conducted to date: five with NWS forecasters and four with broadcast meteorologists.

Preliminary findings indicate that the roles of broadcast meteorologists differ widely from those of NWS forecasters. Broadcast meteorologists use radar to anticipate warnings issued by NWS and to make decisions about cutting into regular programming to provide severe weather coverage. These decisions have the potential to impact the television station financially and to aggravate viewers. In addition, broadcast meteorologists use radar on the air to illustrate the current threat to viewers. NWS forecasters use radar data to make important decisions about issuing warnings and face different concerns from those of broadcast meteorologists. Participants from both groups have stressed the importance of frequent scans at the lowest elevation angle, particularly for tornado detection; some have even admitted to re-starting the volume scan to obtain this information. Other common themes in the interviews include radar horizon issues, de-aliasing problems, beam spreading, and detection of precipitation type.