The Role of Equatorial Waves in Triggering Precipitation Extremes in the Maritime Continent

Abstract This review offers a comprehensive analysis of convectively coupled equatorial waves (CCEWs) and their pivotal role in driving precipitation extremes across the Maritime Continent. It examines the current understanding of CCEWs, evaluates the performance of numerical models and forecasting techniques in predicting these phenomena, and pinpoints critical areas for improvement. The discussion centers on three key types of equatorial waves: equatorial Rossby waves, Kelvin waves, and mixed Rossby–gravity waves. By connecting scientific insights with practical forecasting applications, the review sheds light on the challenges of predicting these waves while identifying opportunities to advance both fundamental knowledge and forecasting accuracy. Designed as an educational resource, it targets operational forecasting centers, meteorologists, and researchers, aiming to enhance the prediction of extreme weather events in the region. Significance Statement Rainfall extremes in the Maritime Continent are among the most intense on Earth, posing major challenges for both society and weather forecasting. This review highlights the crucial role of convectively coupled equatorial waves—large-scale tropical weather systems—in triggering such events. Through both their direct influence and interactions with the diurnal rainfall cycle and other weather systems, equatorial waves amplify precipitation and create favorable conditions for extreme rainfall. Despite their important role in modulating precipitation extremes, they are still underrepresented in many numerical weather prediction models, limiting forecast accuracy. Improving understanding and representation of these waves offers a pathway toward better forecasts and greater resilience in one of the world’s most vulnerable and rain-prone regions.