The impact of storms on barrier islands can be predicted with increasing accuracy due to the development of process-based models and the use of high-resolution datasets. However, data availability is restricted in space and time, and the potential use of hydrodynamic forcing from global wave reanalyses and topobathymetric grids from global digital elevation models has yet to be comprehensively evaluated. In this paper, we seek to use global models to overcome the high cost and limited coverage of high-resolution topographic data while mitigating their own uncertainty. Here, coarse-resolution boundary conditions and grids from global datasets were used to model the impact of a 50-year return period synthetic storm on a dissipative barrier island using SWAN and XBeach. The runs with global models were compared to a baseline run with high-resolution data, with results indicating an overall underestimation in storm impacts for the global model runs. However, the erosional response to the synthetic storm is reproduced appropriately and erosion metrics are consistent with the baseline run, providing encouraging results for storm impact modelling with global datasets.
