PART III: STORM WAVE HINDCASTS 



12. Wind wave spectra for hurricane and extratropical storms affecting 

 the Virginia Beach, Virginia, area during the periods 1928 to 1978 were cal- 

 culated. Data recorded in the vicinity of Norfolk, Virginia, from five hurri- 

 canes and six extratropical storms were used for storm selection and ranked by 

 peak still-water level (swl) (Table 1). The three highest-ranked hurricanes 

 and the three highest-ranked extratropical storms were selected for wave hind- 

 casting using numerical simulation. Hindcast periods which were modeled for 

 each of the six storms are listed in Table 2. 



Table 2 

 Selected Storms 



Swl Rank Hindcast Period* 



Hurricane 



1 21 Aug 1933 OOOOZ — 24 Aug 1933 OOOOZ 



2 14 Sep 1933 OOOOZ — 17 Sep 1933 OOOOZ 



3 15 Sep 1936 1200Z — 19 Sep 1936 OOOOZ 



Extratropical 



1 6 Mar 1962 OOOOZ — 9 Mar 1962 1200Z 



2 11 Apr 1956 2100Z ~ 14 Apr 1956 1800Z 



3 26 Apr 1978 OOOOZ ~ 29 Apr 1978 OOOOZ 



* Z = Greenwich mean time. 



13. Three different modeling procedures were required to perform the 



hindcasts based on type of storm and available data. 



a. All hurricane wind fields were computed by a planetary boundary 

 layer (PBL) vortex model.* Necessary input data for the PEL 

 model were obtained from the National Weather Service's tropi- 

 cal cyclone data set TD-9697. Computed winds were then used as 

 forcing functions for the wind wave spectral transformation 

 model. 



Unpublished report by V. J. Cardone (President, Oceanweather) et al. 

 (1981), titled "Unified Program for the Specification of Hurricane Boundary 

 Layer Winds Over Surfaces of Specified Roughness," Unpublished Report for 

 US Army Engineer Waterways Experiment Station, Vicksburg, MS. 



12 



