Heavy versus extreme rainfall events in southeast Australia

Abstract

Focussing on the major cities of Brisbane, Sydney, and Melbourne in southeast Australia, this study seeks to determine the environmental factors that distinguish between heavy rainfall events (HREs) and extreme rainfall events (EREs). Using daily rain gauge observations, HREs and EREs are defined for each domain based, respectively, on the 95th and 99th percentiles of wet-day rainfall for the period 1979–2018. K-means clustering is applied to mean sea-level pressure, data from ERA5 to obtain a set of representative large-scale circulation patterns associated with these events. Composite synoptic maps, mean vertical profiles, and a series of column-integrated diagnostics are then examined for..