DESIGN HURRICANE TIDAL FLOOD 



B-16, WIND FIELD 



Charts prepared by the Hydrometeorological Section of the 

 U.S. Weather Bureau have provided basic data for \ise of the Beach 

 Erosion Board, the Texas A & M Research Foundation, the Waterways 

 Experiment Station, and the New England Division, Corps of 

 Engineers, for determination of the design hurricane tide elevations 

 in Narragansett Bay, The charts depict the wind flow over 

 Narragansett Bay for the September 19U1| hurricane, transposed to 

 a track over water from Cape Henry, Virginia. The hurricane is assumed 

 to be moving on a hypothetical path due north with a speed of kO knots, 

 so as to pass h9 nautical miles due west of a point at the mouth of 

 Narragansett Bay which produces a wind field most critical to the 

 area. Msiximum winds over a major portion of the bay average 76 miles 

 per hour at the height of the storm. 



The transposed September 19^1; hurricane, described above, was 

 used for the design hurricane tidal flood. Determination of the 

 maximum probable hurricane has not been con^jleted, 



B-17, STORJI SURGE AT MOUTE OF BAT 



Preliminary computations of the water level variations at the 

 mouth of Narragansett Bay for the design hurricane have been carried 

 out for five selected storm speedJs. More detailed calculations were 

 made for 20 and hO knot storm speeds. These have been made by the 

 Texas A & M Research Foundation under contract to the Beach Ebrosion 

 Board. The procedure is similar to that discussed in Report 127-1 

 of the Texas A & M Research Foundation. A summary of preliminary 

 results for the design hurricane follows: 



Shoreward Speed Storm Tide 



of Storm Potential 



(knots) (feet) 



20 10,3 



UO 9.5 



The storm tide noted is the maximum water level rise at the mouth 

 of the bay due to winds and inertial effects alone. 



B-20 



