Evaluation of RADAP II Severe-Storm-Detection Algorithms

Abstract

Computer-generated volumetric radar algorithms have been available at a few operational National Weather Service sites since the mid-1970s under the Digitized Radar Experiment (D/RADFX) and Radar Data Processor (RADAP II) programs. The algorithms were first used extensively for severe-storm warnings at the Oklahoma City National Weather Service Forecast Office (WSFO OKC) in 1983. RADAP IT performance in operational severe-weather forecasting was evaluated using objectively derived warnings based on computer-generated output. Statistical scores of probability of detection, false-alarm rate, and critical-success index for the objective warnings were found to be significantly higher than the average statistical scares reported for National Weather Service warnings. Even higher statistical scores were achieved by experienced forecasters using RADAP II in addition to conventional data during the 1983 severe-storm season at WSFO OKC. This investigation lends further support to the suggestion that incorporating improved reflectivity-based algorithms with Doppler into the future Advanced Weather Interactive Processing System for the 1990s (AWIPS-90) or the Next Generation Weather Radar (NEXRAD) system should greatly enhance severe-storm-detection capabilities.