Quantifying Hail and Lightning Risk Factors Using Long-Term Observations Around Australia

Abstract

There is a growing need to better understand and quantify risks associated with extreme weather, including severe thunderstorm-related hazards such as hail and lightning. Hail occurrence based on a long-term archive of radar observations is presented for the first time in many temperate and subtropical regions of Australia, together with lightning observations from a ground-based network of sensors. Mean monthly and hourly occurrence frequencies are examined for hail and lightning. Environmental conditions obtained from hourly reanalysis data indicate stronger wind shear on average for hail than lightning. The environmental conditions also indicate higher freezing levels on average for lightning than hail. These environmental differences provide plausible physical reasons for observed differences between hail and lightning climatology through the year. The study results are intended to help inform future planning and preparedness for thunderstorm-related risks, including for severe weather forecasting and climate risk applications.