An Operational System for Predicting Hurricane-Generated Wind Waves in the North Atlantic Ocean*

A new wind–wave prediction model, referred to as the North Atlantic hurricane (NAH) wave model, has been developed at the National Centers for Environmental Prediction (NCEP) to produce forecasts of hurricane-generated waves during the Atlantic hurricane season. A detailed description of this model and a comparison of its performance against the operational western North Atlantic (WNA) wave model during Hurricanes Isidore and Lili, in 2002, are presented. The NAH and WNA models are identical in their physics and numerics. The NAH model uses a wind field obtained by blending data from NCEP’s operational Global Forecast System (GFS) with those from a higher-resolution hurricane prediction model, whereas the WNA wave model uses winds provided exclusively by the GFS. Relative biases of the order of 10% in the prediction of maximum wave heights up to 48 h in advance, indicate that the use of higher-resolution winds in the NAH model provides a successful framework for predicting extreme sea states generated by a hurricane. Consequently, the NAH model has been made operational at NCEP for use during the Atlantic hurricane season.