A real-time algorithm for the correction of bright band effects in radar QPE

The bright band (BB) is a layer of enhanced reflectivity due to melting of aggregated snow. The locally high reflectivity causes significant overestimation in radar precipitation estimates if appropriate correction is not applied. The main objective of the current study is to develop a method that automatically corrects for large errors due to BB effects in a real-time national radar quantitative precipitation estimation (QPE) product. An approach that combines the mean observed volume scan vertical profile of reflectivity (VPR) and an idealized linear VPR model was used for computational efficiency. The methodology was tested for eight events across different regions and seasons in the United States. The VPR correction was found to be effective and robust in reducing overestimation errors in radar QPE, and the corrected radar precipitation fields showed physically continuous distributions. The VPR correction worked consistently well for flat land radars because of relative uniform spatial distributions of the BB in those areas. For mountainous radars, the performance of the correction is mixed because of limited radar visibility in addition to large spatial variations of vertical precipitation structure caused by underlying topography.