Tropical Easterly Waves in the Tropical North Atlantic Basin.

Tropical easterly waves (TEWs) serve as precursors to most Atlantic tropical cyclones and strongly modulate the hydrological cycle over West Africa, the tropical Atlantic, and the Caribbean region. Despite significant advances, uncertainties remain regarding the processes governing TEW maintenance and intensification, the relationship with tropical cyclogenesis, and future projections of TEW activity under global warming. Progress on these fronts is constrained by persistent disparities in tracking methodologies, limited observational understanding of moisture-convection feedbacks across scales, and the inability of global climate models to resolve small-scale processes. This review synthesizes the current state of TEW research, from genesis and tracking methodologies to the multiscale impacts of TEWs on tropical cyclogenesis and regional precipitation, and accounts for the modulation of climate variability modes and future behavior under global warming. We also propose a coordinated research roadmap, including a community-driven intercomparison initiative analogous to those successfully implemented for other complex atmospheric phenomena to reconcile uncertainties in tracking methodologies. In addition, we stress the need for intensive field campaigns to validate high-resolution convection-permitting modeling and train artificial intelligence-driven algorithms. Taken together, these initiatives provide a pathway to resolve outstanding uncertainties and improve the reliability of future TEW projections under global warming.