Hindcast Wave Information for the U.S. Atlantic Coast

Abstract

The Coastal Engineering Research Center (CERC) calculated wave information along the U.S. Atlantic coast for the period 1956-1975 in the late 1970’s. Calculations were made with a numerical wave hindcast model using wind speeds and directions calculated from atmospheric surface pressure records and ship observations. Measured wind and wave data became available in the 1980's from a number (If buoys located off the Atlantic coast. Comparisons of mean wind and wave parameters were made between the measurements of the 1980's and hindcast results for 1956-1975 assuming the mean wind and wave climates for the different time periods were the same. Mean wind climates compared well, but mean wave climates differed. The skill of recently developed wave hindcast models indicates that the hindcast wave results could be improved by using present model technology with the previously calculated winds. Comparison of hindcast results, using present technology to measurements for the year 1990 show little bias with respect to wave height and peak period at coincident locations and times. Typical root mean square differences are 0.5m and 2-3 sec for wave height and peak period respectively. The hindcast for 1956-1975 is improved by using higher resolution numerical grids to better represent the U.S. coastline, continental shelf bathymetry, and offshore islands and shoals in the Bahamas region and by using a more accurate wave model. Results are presented at locations and in a format appropriate for present coastal engineering studies.