The frequency and magnitude of extratropical storms along the Outer Banks of North Carolina

Waves generated by extratropical storms are the primary cause of coastal erosion along the outer Banks of North Carolina. Between 1942 and 1967, 857 storms producing wave heights of at least 5.1 feet were investigated to determine frequency, magnitude, and patterns of occurrence. Results indicate that winds generating wave heights over 5.1 feet occur on average every 10 days; a height of 11.1 feet every three months; one of at least 17.1 feet every three years; and a wave height greater than 23.1 feet every twenty-five years. March is the period of maximum frequency with an average of five storms. Cyclonic occurrence during the period investigated indicates twelve-year cyclic trends, with six years of severe storm climate alternating with six years of light storm activity. The last two years of the investigation were the mildest in the twenty-five year interval.

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