A Study on the Future Availability of NEXRAD - Study Approach

The current NOAA/NWS weather surveillance Doppler radar system, NEXRAD, has revolutionized the ability of weather forecasters to understand the severe storm environment and issue timely and accurate warnings. During the past quarter century, the NEXRAD program has executed a continuous program of modifications, retrofits, technology refreshments, and pre-planned product improvement upgrades with the aim to avoid obsolescence, improve data quality, meet new mission requirements, improve system maintainability and reliability, and control operations and maintenance (O&M) costs. Because of the challenges posed by obsolescence in the current system and the advancement of new technologies, plans are underway to replace the NEXRAD network.

To fully understand the magnitude of the risk for mission failure over the next ten years, the MITRE Corporation performed a study of the operational and system availability of the current NEXRAD system. The presenters will describe the approach taken and the data collected to perform the study.

The study reviewed all operational NWS radars for the period from 2008, which marked the beginning of the modern WSR-88D era, through 2023. This period incorporated the addition of dual polarization capability and the infrastructure upgrades from the recent service life extension program. The current NEXRAD system availability requires a threshold of 96% operational availability. This level of performance has been achieved by the constant efforts of the NWS Radar Operations Center, the maintenance technicians, and the sparing and repair capability at NWS’s National Logistics and Reconditioning Center. Data was collected from subject matter experts from each of these locations and the databases that support these activities.

The presenters will discuss their study approach that included the review of historic operational availability data, statistical analyses on the data that included analysis of variance trends and root cause analysis, and performance of a risk assessment of the most vulnerable components and projected future radar unavailability. MITRE will also provide an overview of the assessment tools developed to allow for a quick focus on key components and significant unscheduled outage events.