The development of diagnostics and radar monitoring capability within a newly implemented radar data quality management system (RDQMS)

The use of radar based quantitative precipitation estimates (QPE) within hydrological applications, nowcasting and for assimilation into Numerical Weather Prediction (NWP) is currently limited by issues relating to radar data quality and reliability. These issues range from problems with the performance of radar hardware components to limitations associated with the post-processing algorithms.

A comprehensive radar data quality management system (RDQMS) is currently being developed within the Met Office. This will deliver a range of monitoring and verification information and tools, including: quality monitoring of the radar system performance, comparison of radar-based QPE with rain gauge measurements, and monitoring of Doppler wind and radar reflectivity data using NWP model fields. Long term statistical comparison between synthetic and real observations are used to evaluate the forward modeling of Doppler and reflectivity or to identify problems with individual radars through relative comparisons. Such an improved monitoring system and its associated diagnostic products are expected to result in earlier identification of any issues arising with the radars or radar data quality.

This paper introduces the main components of the RDQMS, presents the statistical information derived, and shows how this can be used to improve the quality of data from the UK radar network. It describes in greater detail the quality monitoring of UK network radars using synthesised observations from the Met Office Unified Model and analyses the biases in azimuth and range that result from partial beam blockages, clutter echoes and the combined effects of the bright band, attenuation by atmospheric gases, rain and clouds and beam broadening. It also discusses potential improvements to the forward model.