This study reports on the atmospheric conditions that are necessary to produce rainfall extremes in three different regions of Australia. It finds that it takes two to tango. In all regions, the ingredients are very high moisture content and strong upward vertical motion. Either of them alone is not sufficient for extreme rainfall. This result highlights the important interplay between the dynamics and thermodynamics of weather systems in making rainfall extremes. In other words, how and where weather systems force ascent, along with how and where they tap into moist air, are crucial. Understanding how extreme rainfall will change with climate change therefore requires us to understand how both moisture and vertical motion change as the planet warms.
White, B.A., Jakob, C., Reeder, M.J., 2022. Fundamental Ingredients of Australian Rainfall Extremes. Journal of Geophysical Research: Atmospheres 127, e2021JD036076. https://doi.org/10.1029/2021JD036076