23Coastal Advancements in NOAA’s STOFS-3D-Atlantic: Enhancing Compound Flood Hazard Prediction for the Atlantic and Gulf Coasts

Coastal flood hazards can result from a combination of factors, including storm surges, high tides, river inflows, and precipitation. Accurate prediction of these complex events necessitates an integrated modeling approach, particularly in the intricate coastal transition zone. This poster presents the latest advancements in NOAA’s Three-Dimensional Surge and Tide Operational Forecast System for the Atlantic and Gulf coasts (STOFS-3D-Atlantic).

STOFS-3D-Atlantic is a 3D baroclinic nowcast/forecast simulation running daily on NOAA’s WCOSS2 at a speed exceeding 100 times real-time. The system employs an unstructured mesh in the horizontal dimension, with elements as fine as a few meters, enabling the resolution of small-scale features such as creeks and flood defense structures. A semi-automated meshing tool ensures accurate representation of critical coastal and riverine features within the forecasts. The hydrodynamic core, SCHISM, adeptly manages multi-scale processes, allowing for the seamless integration of hydrologic flows with coastal dynamics and oceanic processes, thereby delivering precise predictions in the coastal transition zone. The high level of automation in the model setup also shortens the development cycle, facilitating frequent incorporation of new digital elevation models (DEMs) and other enhancements.

Since its operational launch in early 2023, STOFS-3D-Atlantic has proven to be robust and reliable in producing accurate forecasts for both normal and extreme conditions. The system’s forecast products are easily accessible and visualized through the Coastal Emergency Risks Assessment (CERA) web interface. Additionally, daily updates of model outputs and statistics are hosted on an Amazon AWS registry, providing overall and station-specific data. These platforms encourage user feedback, which is instrumental in driving continuous improvements to the system. New features and updates undergo rigorous testing in a “shadow” forecast environment before being integrated into the operational forecast. This presentation will highlight key developments from the current upgrade cycle, showcasing the system’s ongoing evolution to meet the challenges of coastal flood hazard prediction.