Extreme hurricane-generated waves in Gulf of Mexico

Abstract

Accurate predictions and understanding of littoral and coastal wave conditions are of major importance to military operations and civilian coastal zone management. Although WaveWatchIII (WW3) is used by many operational forecasting centers around the world, there is a lack of field studies to evaluate its accuracy in regional applications and under extreme conditions, such as Hurricanes. Data from seven National Data Buoy Center (NDBC) buoys in the Gulf of Mexico, together with an array of pressure and pressure-velocity sensors deployed on the Florida Panhandle shelf during the Office of Naval Research (ONR) SAX04 experiment, were used to test WW3 predictions of extreme waves generated by Hurricane Ivan. The model predicts large differences between wave conditions on the left and right sides of the hurricane track owing to the difference in “dwell time” between wave propagating against and with the storm. Analysis reveals a tendency to predict smaller wave heights and later arrival of hurricane swell than is observed. Additionally, the default operational setting for dissipation by bottom friction yields too much dissipation on the continental shelf. Overall, the agreement between observations and model predictions is reasonable