system to flow into the eye. The warm, moist air flowing into the eye 

 is then heated, ascends, and is dispersed in the upper atmosphere thus 

 providing a vital step in the process of transforming heat to kinetic 

 energy. The more air displaced in the column of the eye, the higher will 

 be the wind speeds. Since the highest pressure gradient is in a region 

 near the eye, the highest wind speeds occur at the place of maximum 

 pressure drop. More specifically, the maximum winds are produced at a 

 region near and to the right of the hurricane center, facing the direc- 

 tion which the eye is moving. 



The creation and maintenance of a hurricane requires a delicate 

 balance of all processes; a breakdown in any of these processes will 

 cause the storm to degenerate. The principal source of energy of the 

 tropical cyclone is the release of the latent heat of condensation in 

 the core or center column; thus, the hurricane can only be maintained 

 over the warm ocean waters. As hurricanes move overland, they lose their 

 cyclonic characteristics rapidly and transform into less intense storms 

 which may move over distances of several hundred miles before completely 

 dissipating. A transformation of wind speeds and direction takes place 

 when a hurricane moves into a coastal area due to frictional drag over- 

 land. This will be seen later to have an effect on the water level 

 variation at shore. 



According to Dunn and Miller (1964), the East and Gulf Coasts of 

 the United States can expect a hurricane to cross the coast on the 

 average of about 2 to 3 per year. Any reaches along these coastlines 

 are susceptible to tropical cyclone crossings. On the West Coast, only 

 California can expect a hurricane, and only infrequently. About six 

 tropical storms per year develop off the west coast of Central America 

 or Mexico and only about one-half of those become full-scale hurricanes. 

 Only about one in 50 of these hurricanes hits California. Tropical 

 storms spawned in the North Atlantic Ocean, including the Gulf of Mexico 

 and the Caribbean Sea, on the average, number about eight per year, and 

 only 58 percent of these reach hurricane intensity. 



Three characteristics of hurricanes are important in establishing 

 their capacity for producing storm-induced wind tides and surface waves , 

 and these may be identified as: pressure differential (Ap) , the differ- 

 ence in pressure at the storm periphery (pn) from that at poj the cen- 

 tral pressure (i.e. in the eye); radius of maximum winds (R) , the dis- 

 tance from the eye to the region of maximum winds ; and the forward speed 

 (Vp) , the speed at which the eye moves . The central pressure index is 

 commonly used for tagging the hurricane intensity, and is abbreviated 

 as CPI . All of these characteristics appear to be dependent to some 

 degree upon the storm's latitude, and they usually vary throughout the 

 storm's life span. 



2. Factors Influencing the Maximum Surge 



The high winds of a hurricane which moves over the Continental 

 Shelf and crosses the coast not only generate high waves but drag a 

 large quantity of water along in the process. For a relatively straight 



