Combined Wind Profiler/Polarimetric Radar Studies of the Vertical Motion and Microphysical Characteristics of Tropical Sea-Breeze Thunderstorms

Abstract

An experiment combining wind profiler and polarimetric radar analyses of intense, but shallow, tropical thunderstorms has been performed. These storms are important as they are very common along many tropical coasts and islands and are sometimes the precursors to large intense multicellular storms such as occur over the Tiwi Islands north of Darwin, Australia. All the storms sampled had a similar structure, with intense updrafts on the periphery of the cells producing significant-sized hail and downdrafts in the storm center. The hail concentrations are relatively small, but have a large effect on the radar reflectivity and polarimetric measurands because of the size (10?20 mm). It is this hail melting that produces characteristic ZDR columns in the polarimetric radar data.