PART II: CLIMATOLOGICAL SUMMARY 



Climate 



8. The FRF enjoys a typical marine climate which moderates the ex- 

 tremes of both summer and winter. Average air temperatures in the coldest 

 months, January and February, are near 5° C; during the warmest months, July 

 and August, temperatures are near 27° C. Ocean water surface temperatures at 

 the FRF tend to be lowest in February, averaging 4° C, and highest in Sep- 

 tember, with an average of 23° C. Because of this lag in the response of the 

 ocean to temperature change, diurnal air temperature differences tend to be 

 greatest in the late spring and fall. 



9. Precipitation annually averages 1,009 mm and is generally well- 

 distributed throughout the year. Frontal precipitation from midlatitude cy- 

 clones predominates in the winter, while local convection (thunderstorms) 

 accounts for most of the summer rainfall. 



10. Winds at the FRF have a distinctly seasonal distribution, being 

 generally from the north and northeast in the fall and winter and from the 

 southwest in the spring and summer. The occasional fall and winter storms 

 (northeasters) can produce winds with average speeds of 15 m/sec or more. Be- 

 sides these midlatitude storms, tropical cyclones (hurricanes) can enter the 

 area. Although the portion of the North Carolina coast in the vicinity of the 

 FRF experiences a fairly low occurrence of direct hurricane strikes (once 

 every 42 years), more frequent near-misses can cause high wave conditions at 

 the FRF. 



Waves 



11. Wave directions at the FRF, as with winds, are seasonally distrib- 

 uted. Waves are predominantly from the northeast in the fall and winter and 

 approach from the southeast in the spring and summer. 



12. The annual mean wave height (measured at the seaward end of the FRF 

 pier) is 0,9 m, with a standard deviation of 0.6 m. Wave heights are gen- 

 erally smallest in spring and summer and greatest in fall and winter. 



13. Wave periods vary throughout the year between about 5 and 16 sec, 

 with an annual mean peak spectral period of 8.7 sec and a standard deviation 

 of 2.9 sec. 



