Table 1 

 PARAMETERS FOR HINDCASTS 



Date 



6 Nov 









7 Nov 



Time (EST) 



0130 



0730 



1330 



1930 



0130 



Velocity (fcn.) 

 Fetch (n.mi.) 



26 



not lim. 



39 

 200 



45 

 180 



55 

 120 



42 

 120 



Duration (hr.) 



3 











By Sverdrup - Munk 



- Bret Schneider Methods 





Min, Dur, (hr.) 

 Min, Fetch (n.mi,) 

 Sig. Height (ft.) 

 Sig. Period (sec.) 



3 

 18 

 5.8 

 5.3 



5.7 

 55 

 15 



8,4 



9.4 

 110 

 24 

 11.0 



9 

 120 

 32 

 12.4 



10.1 

 120 

 23 

 10.8 



By Pierson-Neumann Methcd 



Min. Dur. (hr.) 3 5 9 11 — 



Min, Fetch (n.mi.) — — •— 120 120 



E 0.9 12 45 80 40 



Sig, Ht. (ft.) 2.7 9.8 19.3 25.4 17.9 



Max. Period (sec.) 4,2 6.3 9.5 10.2 9.3 



It is of interest to note that two of the class teams hindcast 

 a wave iraximum of 36 feet while the third hindcast a maximum of 27 

 feet. The authors' maximum using the Bretschneider curves was 32 

 feet; using the Pierson-Neumann technique (with the same forecasting 

 parameters) it was 25 feet. That class team reporting the 27 -foot 

 wave height maximum, in analyzing the weather charts determined a 

 maximum wind velocity significantly lower than that determined by 

 the other class groups. This is not unexpected, interpretation of 

 weather charts being still often a subjective matter, 



Hindcast wave periods also differ. The three class teams reported 

 periods for the maximum portion of the storm of between 13.0 and 13.5 

 seconds. The authors' hindcast periods were 12,4 seconds for the 

 significant period by the Bretschneider technique and 10,2 seconds 

 as the maximum period by the Pierson-Neumann technique; this value 

 corresponds to an average period of about 8 seconds. 



16. 



