This project would use the coupled ADCIRC-WaveWatch III modeling system in a test case to validate the model performance in representing total water level as a combination of storm surge, tides, and wave activity. The model system will be validated for previous hurricane events for which (1) damage from the storm’s inundation led to incidents of buildings being destroyed to their foundation (i.e. “slab” scenarios), and (2) more data on total water level recordings are available to validate the model performance, and (3) pre-existing unstructured triangular grids are available for use, with little or no modifications, in the hindcast simulations. For this project, skill assessment techniques and criteria will be determined that will be consistent with the goal of the COASTAL Act to have models that are 90% accurate. This project will also support coupling to WAVEWATCHIII on an unstructured grid system, critical to achieving the 90% requirement for water levels. The two modeling systems will be dynamically coupled to exchange physical processes so as to obtain accurate estimates of total wave–surge induced inundation. Coupling strategy will be based on long term aligning with overall NOAA plans for coupled modeling as well as being cognizant of deliverable schedules. At those locations where data are available for the hurricane hindcast scenarios, the performance of the coupled model will be evaluated using the skill assessment techniques. While an updated Hurricane Surge On-Demand Forecast System (HSOFS) grid is in development, separate pre-existing grids with higher local refinement and overland coverage will also be used in this assessment to fully evaluate the model resolution requirements for the COASTAL Act.