1. Data Availability . 



Tables 3, 4, and 5 are quick reference guides showing a weekly breakdown 

 of the various types of data available for 1977, 1978, and 1979, respectively. 

 Wave instrument histories, which are provided in Appendix A, may explain major 

 gaps in the data. Detailed listings of available analog chart records for the 

 meteorological Instruments are provided in Appendix B. 



2. Wave Data . 



Appendix A contains significant wave height and peak period summaries for 

 each BEM wave sensor which Include (a) the gage history; (b) a table of over- 

 all, annual, and monthly maximums, means, and standard deviations of signifi- 

 cant wave height and peak period; and (c) tables of the joint distribution of 

 significant height versus peak period for the overall time of operation. 



Figures 6 and 7 present the extreme, mean, and standard deviation of the 

 mean significant wave height values for those months where at least 50 percent 

 of the observations were obtained from the Nags Head and pier-end staff gages, 

 respectively. Thompson (1977) used the 50-percent cutoff to ensure the relia- 

 bility of data summaries. 



Table 6 is an annual joint distribution of significant height versus peak 

 period for the Nags Head gage during 1977. This table gives the frequency of 

 the significant wave height and peak period within specified intervals, based 

 on the number of observations per 1,000 observations. These values can be 

 converted to percent by dividing by 10. A detailed explanation of the table 

 format is provided in Appendix A. 



Tables 7 and 8 show the same type of distributions during similar times of 

 operation in 1978 for the nearshore (615) and pier-end (625) staff gages. The 

 data in these tables are relatively incomplete and should not be used for 

 determining annual trends; the tables are Included to emphasize differences 

 between the pier-end and nearshore locations. 



Figure 8 shows the annual cumulative significant height distributions for 

 a relatively complete year of data from Nags Head during 1977 and from the FRF 

 pier-end staff gage during 1978. Figure 9 shows the typical distribution of 

 peak wave periods during the same years of data; a solid line histogram repre- 

 sents the 1977 data for Nags Head and a symbol indicates the 1978 data for the 

 pier-end Baylor staff gage. 



3. Tides and Water Levels. 



The history of tide gage operations for the two FRF installations is 

 provided in Table 9. Data from these gages were reduced by NOS, and monthly 

 tabulations of daily high and low waters and hourly heights are available at 

 NOS (see Sec. VI). However, monthly mean values of the water level parameters 

 defined below are presented in Figures 10 and 11 and Tables 10 and 11: 



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