3 Wind Wave and Swell 

 Climate 



Sources 



Three sources of wind wave and swell information were available to develop 

 wave climate outside the harbor entrance (Table 6 and Figure 30). The first was 

 the directional array gage in the 47.6-ft (14.5-m) depth just outside the harbor 

 entrance (CDIP gage 77). Data from November 1993 through December 1994 

 were used. The second was the directional buoy north of Molokai (NDBC buoy 

 51026) with data from October 1993 through May 1994 and September through 

 December 1994. These gages are discussed in Chapter 2. The time intervals 

 used were intended to be reasonably representative of the seasons of the year so 

 that the gage data could be compared to long-term climate. Inclusion of the 

 additional three months of available array data (Jan-Mar 95) would have 

 distorted the distribution toward winter conditions (high wave heights). 



The third source was the Wave Information Studies (WIS). WIS has hindcast 

 waves over the North Pacific Ocean and saved information at selected deepwater 

 stations around the Hawaiian Islands (Corson et al. 1986). Station 31, north of 

 Maui, from the main 20-year hindcast, was considered in this study. The study 

 also included two stations from a specially prepared 1-year WIS update 

 coincident with the measurement time period. Stations of interest in the special 

 update, which used a different grid, are shown in Figure 30 (Stations 3 and 5). 

 Results from Station 5 were compared to data from the NDBC buoy to validate 

 the special hindcast Sample validation plots and wave summaries are given in 

 Appendix D. 



Deepwater Wave Climate 



Although an NDBC buoy and three WIS stations are available in deep water 

 offshore from Kahului Harbor, only WIS Station 31 provides long-term climate 

 information. It is important to evaluate whether the locations and time period of 

 measurement and special hindcast are representative of the long-term 



34 



Chapter 3 Wind Wave and Swell Climate 



