Henrique Moreno Dumont Goulart , Karin van der Wiel, Bart van den Hurk, Kees van Ginkel, Panos Athanasiou, Gundula Winter, Izidine Pinto

Coastal settlements, facing increasing flood risk from Tropical Cyclones (TCs) under climate change, need local and detailed climate information for effective adaptation. Analysis of historical events and their impacts provides such information. This study uses storylines to evaluate adaptation strategies, focusing on Cyclone Idai’s impact on Beira, Mozambique, under different climate conditions and tidal cycles. A storyline of Idai under 3°C warming increases flood impacts by 1.8 times, while aligning Idai with spring tides amplifies these by 21 times. Combining both conditions increases impacts beyond 37 times. An adaptation strategy combining flood protection and accommodation measures reduces impacts by maximum 83\%, while a seawall strategy reduces these by 10\%. By offering localised, detailed information, storylines can be used to measure the effectiveness of adaptation strategies against extreme events, evaluating their robustness across different scenarios, and quantifying residual impacts, complementing traditional climate risk assessments for informed decision making.