Real-Time Forecasting System of Winds, Waves and Surge in Tropical Cyclones: A Case Study with Hurricane Georges

The long-term goal of this partnership is to establish an operational forecasting system of winds, waves and surge impacting the coastline during the approach and landfall of tropical cyclones. The results of this forecasting system would provide real-time information to the National Hurricane Center during the tropical cyclone season in the Atlantic for establishing improved advisories for the general public and federal agencies including military and civil emergency response teams. As more people and societal infrastructure concentrate along coastal areas, the United States is becoming more vulnerable to the impact of tropical cyclones. Furthermore, it is not surprising that hurricanes are the costliest natural disasters because of the changes in the population and the national wealth density or revenue. A better understanding of both hurricane frequencies and intensities as they vary from year to year and their relation to changes in damages is of great interest to scientists, public and private decision makers and the general public.

The estimation of tropical cyclone-generated waves and surge in the coastal waters and nearshore zone is of critical importance to the timely evacuation of coastal residents, and the assessment of damage to coastal property in the event that a storm makes landfall. The model predictions of waves and storm surge in coastal waters are functionally related and both depend on the reliability of the atmospheric forcing. Hurricane Georges is an excellent example of an intense tropical cyclone with numerous landfalls and unexpected changes in intensity and movement. Results of real-time forecasting simulations for Hurricane Georges will be presented as the storm segment moved over the Florida Straits and then entered the Gulf of Mexico. As it approached the coast of the central Gulf of Mexico it gradually slowed. Georges made its final landfall near Biloxi, Mississippi early on 28 September with 105 mph winds. Results will include both the predicted wave heights and surge-induced water levels along the Mississippi/Alabama coastline prior and during landfall of Georges. We will also show the variability of these parameters for different forecasted tracks and how such information would impact the advisories.