Lower California coast, and it subsequently dissipated after it encounter- 

 ed the coast of Southern California, The weather maps in Figure 7 show 

 that the storm decreased in intensity from September 22 to September 25» 

 As it traveled northward toward the coastline the winds in the eastern 

 portion of the storm were always directed toward Long Beacho This con- 

 dition, together with the moveirent of the storm, produced an effective 

 fetch which exceeded 1,000 miles „ The velocity of the storm's center was 

 approximately 15 knots during the interval 1630 P<,SoT., September 21 to 

 1630 PoSoT., September 22, after which it gradually decreased to about 6 

 knots by 1630 PoSoTo, September 24 „ 



In order to determine the longest possible effective fetch, within 

 the limits of available weather data, the speed of the wave energy front 

 which remained under the influence of strong winds for the longest time 

 was computed relative to the speed of the storm. This energy front would 

 be expected to emerge from the fetch before the strong winds from the 

 storm reached San Pedro Bay. However, because the wind field quickly 

 elongated and was extended to Long Beach during the period 04-30-1630 PoS,T. 

 September 24 as shown in Figure 7, the waves comprising the energy front 

 continued to grow under these winds all the way to Long Beacho In 

 addition^ the extended wind field represented an earlier local fetch which 

 produced short period wind waves of considerable height. 



Between 1630 PoSoT,, September 24 and 0430 PoS,T,, September 25, the 

 storm elongated in an east-west direction. Soon after the 0430 map the 

 winds at San Pedro Bay subsided to calm or light and variable, and the 

 storm center moved toward the coast in the region between San Pedro and 

 San Diego, At about 0700 the winds at San Pedro backed to the northeast, 

 but a small fetch still existed to the south. The existeance of this 

 fetch is verified by the south winds which ware recorded at San Pedro 

 for soma period after the windshift occurred at San Pedro (Table 1). By 

 1630 PcSeTc, September 25 the storm's center was no longer distinguishable. 



Computed deep water wave conditions , - The computed deep water 

 characteristics at San Pedro Bay for waves from the tropical storm are 

 tabulated in Table 2 and presented graphically in Figure 8, Swells from 

 westerly directions preceding and following the waves from the tropical 

 storm are also shown on the graph. The time wten generation began as 

 shown in Table 2 was the initial time at which the average wind velocity, 

 U, applied. Prior to this time lighter winds which preceded the main 

 fetch had produced low waves of short pariod. These waves were still 

 present in the fetch area at the time generation began. As a result, the 

 actual fetch, F, shown on the weather maps was effectively increased by 

 the distance required to generate the short low waves at velocity, U, 

 This distance together with the fetch sho-wn on the weather maps and the 

 distance the storm moved with the waves dioring generation comprise the 

 effective fetch, Fe a The wave height and period at the end of the fetch, 

 H^i' and Tj,., have been computed using either F or Fg, whichever was greater. 



The opposing wind which existed in the decay area aftar about 0700 

 PcSoT, September 25 was allowed for by increasing the decay distance, D, 

 by a certain amount (Arthur, 1948), The wave height and period at the 



