Using computer graphic workstations 24 hour offshore wind & wave forecast cover adjacent and offshore waters of the eastern and western U.S. and are generated twice a day. These charts are based on the regional surface forecast and depict forecast winds (knots) and significant wave heights (feet). Maximum significant wave heights analyzed does not take into account higher individual wave heights. Significant wave height is defined as the average height of the highest 1/3 of wave heights observed. In addition the Atlantic Regional Wind/Wave Forecast includes a forecast of the north and south walls of the Gulf Stream. The forecast uses sea surface temperature data from the US Navy. Data from the Navy is available Monday, Wednesday, and Friday. This data is used by NOAA Coastal Ocean Forecast System (COFS) to aid meteorologists in forecasting the north and south walls of the Gulf Stream. The North Wall is depicted on the chart as a thick solid black line and South Wall as a thick dashed line.