September and January through March; during April through June, the least 

 severe conditions occurred (Figure 13). 



73. The overall wave climate during 1981 was more severe than during 

 1980 (Figure 14). At gage 625 near the seaward end of the pier, 7 percent 

 of the wave heights exceeded 2 m during 1981, while less than 5 percent did 

 during 1980. Seasonal variation also differed from 1980. The much greater 

 frequency of higher waves in August (Figure 15) and a succession of storms in 

 September 1981 resulted in a much more severe summer (July through September) 

 than 1980 (Figure 16). A mild January in 1981 was the primary reason the 

 winter season (January through March) was less severe than the winter of 1980. 

 These two seasons were thus reversed between years in order of severity. 



74. The extreme H at the seaward end of the pier for 1981 was 



m 



3.5 m, which occurred in November during an extratropical northeaster storm 

 (see Appendix D for storm data). This matched the 1980 extreme. 

 Wave period 



75. Annual wave period distributions were consistent from gage to gage 

 (Figure 17). The 1981 annual average wave period at the seaward end of the 

 pier (gage 625) was 8.4 sec, with an associated 2.8-sec standard deviation 

 (see tabulation, paragraph 70). Figure 18 shows the 1981 wave period 



-1 — I — I I I 1 1 1 1 — I — I — I I I 1 1 1 



10° 10' 



PERCENT GRERTER THAN INDICATED 



Figure 13. 1981 seasonal wave height 

 distributions for gage 625 



41 



