PART II; 



STORM SURGE HYDROGRAPHS 



9. Design water level conditions were provided by NAO and selected 

 from a review of historic storm events that have impacted the Virginia Beach 

 area. Eleven storms of record are ranked by peak storm surge height, and the 

 maximum three for each class of storm are selected (Table 1) . Water level 

 elevations shown are for a tide gage (Norfolk Harbor) located approximately 

 10 miles inside the Chesapeake Bay. These data were used because no gage was 

 located at the study site during the storm event or the storm or because the 

 gage failed or was destroyed. Select data were later corrected by NAO for use 

 at the study site. The three severest storms (highest ranking) of each class 

 (i.e., either a hurricane or extratropical) were evaluated to determine which 

 design conditions would be used in physical model tests. 



Table 1 

 Historic Storm Events 























;e 



Class 



of 



H 



Storm* 



Surge Height 

 ft 





Storm 



Ranking 



Dat 



Hurricane 



1 



Extratropical 



23 Aug 



1933 



8.05 





18 Sep 



1936 





H 





7.55 



2 







7 Mar 



1962 





E 





7.06 







1 



16 Sep 



1933 





H 





6.35 



3 







11 Apr 



1956 





E 





6.34 







2 



12 Sep 



1960 





H 





6.09 



4 







18 Sep 



1928 





H 





5.85 



5 







27 Apr 



1978 





E 





5.84 







3 



27 Sep 



1956 





H- 



•E** 



5.74 







4 



6 Oct 



1957 





E 





5.53 







5 



5 Oct 



1948 





E 





5.35 







6 



* H - hurricane; E - extratropical storm. 

 ** Before impacting the study area, this hurricane was reclassified as an 

 extratropical storm. 



10. The evaluation considered the three major hurricanes and three 

 major extratropical storms of record. Documented wind fields associated with 

 the six events were then used in the numerical model SHALWV (Hughes and Jensen 

 1986) to hindcast the deepwater waves and to transform them into shallow 

 water. From this analysis the severest storm event for each class of storm, 

 hurricane and extratropical, was used in the model tests. Figure 3 



