Analysis of Validated Wind Forcing and Storm Surge from Hurricane Florence

Storm surge is the result of meteorological forcing and the affected area’s geography. Thus, it is essential that accurate meteorological forcing be used when simulating storm surge events. For tropical cyclones affecting shallow coastal systems, the strong winds that create stress on the surface of the water are the primary driver, with some additional rise in water created by the barometric pressure deficit within the core of the storm. This forcing generates the forerunner, often due to Ekman setup and waves, which contributes to the water level setup, driving water towards and onto the shore. Together, these influence the magnitude, location, and timing of surge along the coastline. In the present study, the goal was to examine the impact of error in different sources of meteorology on the storm surge of Hurricane Florence. Several meteorological products were evaluated, including Ocean Weather, Inc. (OWI), HWRF, ERA5, COAMPS-TC, and the Holland based parametric model in ADCIRC, using 61 meteorological stations in coastal North Carolina. Each meteorological product was then used as forcing for a high-resolution implementation of ADCIRC + SWAN to evaluate the impact on storm surge. Comparisons were made with 66 water level gauges throughout the region. Results emphasize the difference in available meteorological products as well as the importance of accurate meteorological forcing to achieve accurate storm surge predictions.