Storms/Wind 



It will be best for the early OFEF's to avoid areas of strong storms because of the 

 high waves and surface currents generated by them. If possible, areas of storm-force winds 

 {> 25 m/sec) and hurricane-force winds (> 33 m/sec) should be avoided, and encounters 

 with gale-force winds (> 17 m/sec) should be minimized. In the north, extratropical cy- 

 clones are generated in the Gulf of Alaska, and these frequently move toward the south with 

 diminishing intensity and frequency to a maximum southern limit of about 30°N. Subtrop- 

 ical cyclones move from an area of generation near 15°N to the west and northwest with 

 diminishing intensity to about 35°N (maximum northern limit of tropical storms). North of 

 about 35°N, and particularly to the northwest, storms and high-wind velocities are common. 

 In the south, between 10°N and 30°N, and to the west to 160°W the probability of strong 

 subtropical storms and hurricanes is high, and these areas should initially be avoided. Areas 

 of low-velocity winds with low probability of intense storms (the most desirable for OFEF 

 location) are given below in order of preference. 



1 . Southern California and northern Baja CaHfomia between 35°N and 30°N within 

 97 kOometers of the coast, (areas 1 through 9 and the northern portion of 10). This area has 

 the lowest probability of extreme winds of any coastal area in the United States (approxi- 

 mately 1 storm > 25 m/sec in a 5-year period). 



2. 25°N to 32°N, 120°W to 140°W (areas 15 and 18). 



3. Leeward side of Hawaiian Islands (area 5 1 , Fig. 48). 



4. Trade wind regions south of tropical cyclone areas, 10°N to 10°S from the coast, 

 west to 160°W. (Relatively constant winds of 5-10 m/sec.) 



Waves 



Wind-generated waves are relatively constant througliout the survey area. The mean 

 wave height is between 1 and 1 .5 meters in all areas (Table 4); however, 99.5 percentile and 

 extreme waves are highly variable. North of 35°N. both along the coast and to the west, 5- 

 year significant and extreme waves are higher than the proposed engineering limitations for 

 preliminary farms (1 1 and 19 meters, respectively). Areas to the south, particularly the 

 coastal regions from 34°N to 27°N and west to 125°W (areas 1 througli 10 and the eastern 

 half of 18, Fig. 1) and regions 20 to 23 (Table 5), show very low wave heights and 10-year 

 extremes within the designated criteria. South of this area, to about 10°N, tropical cyclones 

 can cause very high waves which in conjunction with high currents might cause structural or 

 plant damage to an OFEF located in this area. Wave heights increase in a westerly direction. 

 OWS N (30°N, 140°W) is marginal, with an estimated 5-year significant wave height of 1 1 

 meters (Table 6). North of OWS N waves become significantly higher, making this region 

 less desirable as an OFEF site. In Hawaiian waters, extreme wave heights on the windward 

 side of the islands are estimated to be significantly higher than on the leeward side (area 5 1 , 

 Table 5). The leeward side is within the engineering wave height limitations for 1 0-year 

 waves, while the windward (north and east) side is not. 



The southern California/northern Baja region is the area of least severe wind- 

 generated waves. 



86 



