Forecasting hurricane impacts on US coasts

The 2024 Atlantic hurricane season was active with 5 landfalling hurricanes in the USA: Beryl, Debby, Francine, and major hurricanes Helene and Milton. In the framework of the National Oceanographic Partnership Program  “Hurricane Coastal Impacts” project, we forecasted the wave conditions, water levels, flooding, beach and dune erosion, and infra-structural impacts on building and bridges due to the combination of rainfall-induced flooding, surge, waves and tides for all these hurricanes. To this end, we developed and implemented an operational system of coupled numerical models such as SFINCS - which is used innovatively as a surge model and as an overland flood model -, a new fast wave model Hurrywave, the morphodynamical model Xbeach and the damage model FIAT, all developed at Deltares. The models are driven by operational US Navy COAMPS-TC and NOAA GFS forecasts. 

The presentation will show the model forecast results, validated against in-situ and remote-sensed observations obtained by project partners. The presentation will demonstrate the relative importance of typo-bathy (vertical) accuracy and the presence of vegetation.

The system also predicts the uncertainty bands in the forecasts and their evolution over time as the hurricane nears landfall. The system is transferrable to other data-rich and data-poor coasts, such as Mozambique of which an example will be shown.

The information that the system provides gives insight to coastal authorities to make decision on anticipatory actions and emergency response. The results of this work are of interest to geomorphological scientists, DRR experts and coastal authorities.