Large Scale Unstructured WAVEWATCH III for Hurricane Hindcasts: Offshore and Nearshore Validation

Abstract:

The spectral wave model, WAVEWATCH III (Abdolali et. al 2020) has been known for its applicability in large scale operational wave forecasting systems. Recent advances in the model performance for the nearshore applications during high wind events has made it a powerful tool for hurricane hindcasts. In these regards, the model uses unstructured grids to represent the open ocean at coarser resolutions moving to higher resolution in the nearshore. In this study, we performed a sensitivity analysis using two different resolution meshes, a 1.8 million node mesh with an approximate 200m min resolution and a 4 million node mesh with 120m min resolution along with observational data to visualize the accuracy of results from the model.

Hurricane Florence was our test storm, which made landfall near Wrightsville Beach, North Carolina in September 2018. While Florence reached category 4 on the Saffir-Simpson Scale, it made landfall as a category 1 pushing an estimated 2 to 3m of storm surge up into the Neuse River and its tributaries and 1 to 2m of surge along the Atlantic Ocean coastline near Onslow Bay. The model was forced with atmospheric data from HWRF (Hurricane Weather Research and Forecasting) and HRRR (High-Resolution Rapid Refresh) models and one-way coupled with the ADCIRC (ADvanced CIRCulation tide and surge model), to incorporate water level and currents. We validated the one-way coupled model with data from satellite altimeters, NDBC off-shore buoys and 26 rapidly deployed USGS gauges duringHurricane Florence landfall (2018).

Reference:

Abdolali A., Roland, A., Van Der Westhuysen, A., Meixner, J., Chawla, A., Hesser, T., Smith, J.M. and M. Dutour Sikiric (2020), Large-scale Hurricane Modeling Using Domain Decomposition Parallelization and Implicit Scheme Implemented in WAVEWATCH III Wave Model, Coastal Engineering, 157, 103656, doi.org/10.3390/jmse8050308