Wave data from past measurement programs are available at the National 

 Oceanographic Data Center, Washington, D.C. 20235. Shipboard observations 

 covering U.S. coasts and other ocean areas are available as summaries (Summary 

 of Synoptic Meterological Observations, SSMO) through the National Technical 

 Information Service, Springfield, Va. 22161. See Harris (1972a, b) for a 

 preliminary evaluation of this data for coastal engineering use. 



When data are not available for a specific location, the vave climate can 

 often be estimated by extrapolating from another location — after correcting 

 for differences in coastal exposure, winds, and storms — although this can be a 

 tedious and uncertain procedure. 



On the east, gulf, and Great Lakes coasts, local winds are often highly 

 correlated with the direction of longshore currents. Such wind data are 

 available in "Local Climatological Data" sheets published monthly by the 

 National Weather Service, National Oceanographic and Atmospheric Administra- 

 tion (NOAA), for about 300 U.S. weather stations. Other NOAA wind data 

 sources include annual summaries of the Local Climatological Data by station 

 (Local Climatological Data with Comparative Data), and weekly summaries of the 

 observed weather (Daily Weather Maps), all of which can be ordered from the 

 Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 

 20402. 



Local weather data are often affected by conditions in the neighborhood of 

 the weather station, so care should be used in extrapolating weather records 

 from inland stations to a coastal locality. However, statistics on frequency 

 and severity of storm conditions do not change appreciably for long reaches of 

 the coast. For example, in a study of Texas hurricanes, Bodine (1969) felt 

 justified in assuming no difference in hurricane frequency along the Texas 

 coast. In developing information on the Standard Project Hurricane, Graham 

 and Nunn (1959) divided the Atlantic coast into zones 322 kilometers (200 

 miles) long and the gulf coast into zones 644 kilometers (400 miles) long. 

 Variation of most hurricane parameters within zones is not great along 

 straight open stretches of coast. 



The use of weather charts for wave hindcasting is discussed in Chapter 

 3. Computer methods for generating offshore wave climate have improved 

 considerably over the last decade and are now a viable tool for an office 

 study of wave climate. However, development of nearshore wave climate from 

 hindcasting can be a time-consuming job. Even with the best computer methods, 

 the wave climate must be used with discretion because wind information over 

 the ocean is often incomplete and knowledge of nearshore topography and its 

 effect on the wave is usually limited. Nearshore wave climate data obtained 

 by advanced state-of-the-art computer hindcasts are available for the entire 

 Atlantic coast of the United States (Corson, et. al., 1981). Similar wave 

 climate information development is planned for the Pacific, gulf, and Great 

 Lakes coasts of the United States. 



Other possible sources of wave climate information for office studies 

 include aerial photography, newspaper records, and comments from local 

 residents. 



Data of greater detail and reliability than that obtained in an office 



4-4 2 



