CASCADE4 aims to improve confidence in future projections of low-likelihood, high-impact (LLHI) weather events by focusing on four classes of LLHI extremes, one of which is tropical cyclones (TCs). Here, we examine Atlantic TCs and one of their most common precursors, African easterly waves (AEWs), in observational and reanalysis data. This work falls under two of the main themes of CASCADE4: leveraging the observational record to understand LLHIs, and developing a physical understanding of the drivers of LLHIs. The relationship between AEWs that develop into TCs and the characteristics of the resulting TCs remains uncertain. Additionally, less attention has been paid to the characteristics and trends of Atlantic TCs that do not develop from AEWs. We address these knowledge gaps by identifying Atlantic TCs that do and do not develop from AEWs from the observational record, and tracking developing AEWs in reanalysis data using an objective tracking algorithm. Our results indicate a robust relationship between the strength of developing AEWs and TC genesis location and landfall. We found that weaker AEWs develop closer to the Americas than stronger AEWs. TCs that develop from weaker AEWs are therefore more likely to make landfall due to the close proximity of their genesis locations to the Americas. We also found that the increasing trend in Atlantic TCs over the past four decades is primarily due to an increase in TCs that develop from AEWs, whereas there is no trend in TCs that do not develop from AEWs. These results demonstrate the importance of examining the physical drivers of TCs to better understand how TCs may respond to future climate change.