Dual-Doppler and Dual-Polarization Radar Analysis of the 27 November 2014 Brisbane Hailstorm

On 27 November 2014, a devastating supercell storm hit the Brisbane region, producing torrential rain, destructive wind speeds, 6000 lightning strikes, and widespread hail resulting in damage costs over $1 billion. The South-East Queensland region experiences over 200 thunderstorms a year. Improving the warning lead time for such events is therefore a priority and should be driven by fundamental research on thunderstorms using advanced radars and high-resolution numerical modelling.

The CP2 research-grade dual-polarization radar and the Mt Stapylton operational weather radar fully sampled the Brisbane supercell storm. In this study our aim is to analyse these radar observations in order to show how operational dual-polarization radars and a denser radar network allowing for dual-Doppler 3D wind retrievals could be used operationally in the future to improve the warning lead time of such catastrophic events and assist with post-event mitigation. Particular attention will be on the early detection of the hail core and of the downdrafts associated with the descent of the hail core, conducive to low-level gust winds. To do so, the temporal evolution of the high-resolution 3D wind (1 km horizontal resolution) and the CP2 classification of hydrometeor type (including hail and rain/hail mixture) are analysed during the storm life cycle, allowing for a comprehensive characterization of the dynamical and microphysical processes involved in the rapid intensification of this supercell.