Another important result found in the three limited area model 

 simulations is the appreciable water surface elevation obtained at 

 the edge of the shelf. This water level perturbation, excluding the 

 inverted barometric height at the edge of the shelf, *, reaches a 

 maximum of0.1m-0.3m. In the simulations of the same storms with 

 the actual wind field, the maximum * increases to 0.7 m - 0.8 m. The 

 maximum of * and the peak surge at the coast, locations where the two 

 peaks occur and the ratio of the two peaks obtained from all 

 simulations are presented in Table 4. 



It is important to note that the differences in the maximum peak 

 surges at the coast between the full and limited area model 

 simulations are comparable to the differences in the * maxima. The 

 presence of * is important to a properly posed open boundary- 

 condition for limited area coastal surge models. Generally, these 

 models neglect * by specifying a constant water level, which is 

 equivalent to the inverted barometric height, as the open boundary 

 condition. As noted above, this condition might result in an 

 underestimated maximum peak surge at the coast by a value comparable 

 to the neglected *. Another salient feature of * pertaining to the 

 consideration of open boundary conditions is the nonuniform 

 distribution along the shelf break. Figs. 112 through 114 show 

 profiles of * obtained from the original versions of HUR5, HUR23 and 

 hurricane Car la. The nonuniformity of these profiles implies that 

 the effect of * on the peak surge at the coast is different from one 

 grid block to the other. This result ultimately prompted a question 

 on specifying a constant water level along the shelf break as the 



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