Performance Evaluation of the NEXRAD (Next Generation Weather Radar) Hail Algorithm Applied to Colorado Thunderstorms

摘要

The relationship between the NEXRAD storm identification algorithms and the Hail Algorithm is described. Skill scores are used to evaluate the performance of the Hail Algorithm when applied to radar reflectivity data for Colorado thunderstorms whose precipitation phenomena were verified by field observers. The Hail Algorithm successfully diagnoses the multiple pulse (long-lived) severe hailstorms while having no skill for diagnosing single pulse (short-lived) severe hailstorms. The best hail indicators for distinguishing between severe hailstorms and non-hail thunderstorms are the storm maximum reflectivity > or = 55dBz and mid-level (5 to 12 kilometers) reflectivity > 50 dBZ.