79. January through March and October through December were seasons 

 with waves predominantly from the north (Figure 21). Waves approached from 

 the south from April through September; over 70 percent of waves approached 

 from the south during April through June. 



80. As shown by the wind roses in Figures 6 and 8 and the wave roses 

 in Figure 21, seasonal trends and the overall distribution of wave directions 

 agree with trends in the wind climate at the FRF. In particular, an increase 

 or decrease in northerly winds was the primary factor affecting the distribu- 

 tion of northerly wave directions during the year. This suggests northerly 

 waves (which include the more severe heights) were produced most often by 

 local winds. On the other hand, variation in the frequency of waves from the 

 south frequently were not consistent with the observed onshore winds from the 

 south. In September, for example, there were few southern, onshore winds, 

 but substantial wave action approaching the shore from directions south of 

 the pier (Figure 22) . This resulted from three tropical storms which devel- 

 oped well offshore to the south of the FRF and produced swell from that 

 direction. 



81. Overall, waves approached from south of the pier 5 percent more 

 frequently during 1981 than during 1980. Despite similar seasonal tendencies 

 for northerly waves in January through March and October through December and 

 southerly waves for April through September, monthly variations of northerly 

 and southerly directions were large throughout the years. 



82. Differences are emphasized by the resultant vector wave height 

 magnitudes and directions tabulated below. These resultants were computed by 

 vector-averaging the daily wave height and direction vectors. 



Resultant 

 Magnitude, m 

 Season 1981 1980 



Resultant D: 

 Ref True 



Lrection 

 North 



1981 







1980 



66 







52 



78 







70 



70 







75 



61 







46 



January-March 1.0 0.9 



April- June 0.6 0.6 



July-September 0.7 0.6 



October-December 1.1 0.9 



83. During January through June 1981, more waves arrived from the south 

 than during the same period in 1980; on the other hand, during July through 

 September 1981, slightly more arrived from the north. From October through 



48 



