(c) the longest average significant wave periods occur in 



October, August, July, December, and September (in order 

 of decreasing periods) and range between 9.2 and 8.5 

 seconds . 



Cd) a large standard deviation occurs and there are very small 

 monthly differences in both heights and periods. 



The effects of the shelf geomorphology on wave refraction, and 

 resulting shoreline wave energy distribution, are discussed in Section 

 II, 2. 



3. Winds . 



Wind data from the Norfolk International Airport, approximately 

 16 kilometers west of Cape Henry are summarized in Figure 11. North- 

 east and southwest winds occur only slightly more frequently than 

 the other directions. However, the high velocity winds (especially 

 greater than or equal to 11 meters per second) are much more frequent 

 from the northeast. The lack of importance of higher velocity north- 

 west winds in the Norfolk data supplied by the National Climatic 

 Center (Asheville, North Carolina) is not consistent with data 

 recorded at other weather stations around Chesapeake Bay (Rosen, 1976), 

 with Hatteras wind data (Gutman, 1977), or with data recorded by Gutman 

 (1977) and Gutman, Hennigar, and Goldsmith (1977) described below. 



Additional wind data between January and October 1976 are sum- 

 marized in Figure 12 from an anemometer installed on top of 

 Currituck Beach Lighthouse (Gutman, 1977) (Fig. 1) . The instrument 

 used was a Bendix-Frieze Recording Anemometer located 168 feet 

 (51 meters) above MSL. It operated continuously. Data were reduced 

 at VIMS according to standard National Weather Service format where 

 average readings are taken every 3 hours (eight readings per day) . 



Note the importance of both the daily and high velocity winds 

 from the north, northwest, and southwest relative to the less frequent 

 northeast winds. A maximum wind of 100 miles per hour (44.7 meters 

 per second) was recorded on 9 October 1976, due to a tornado which 

 actually touched down in Corolla. 



4 . Storms and Storm Tides . 



Extratropical storms (1956 to 1969) , tropical storms (1964 to 

 1969), and the time of operation of the Virginia Beach gage (1964 to 

 1969) were summarized by Gutman (1976) from information provided by 



42 



