Climate Change: The Coastal Storm Season

Hayden, B. P. (1975). Storm Wave Climates at Cape Hatteras, North Carolina: Recent Secular Variations. Science 190:981-983.

Abstract

Mid-Atlantic coastal wave climates have undergone significant change within the last three decades. The duration and frequency of storms generating high waves and the length of the winter storm wave season have increased. These changes may, in part, account for the observed trend in shoreline erosion along the east coast of the United States.

The larger number of autumn storms accounts for most of the expansion of the winter storm season. However, the extension of the storm season in to the spring is also evident in the data. Changes in the number of storms is also evident in the history of the climate of waves produced by these storms.

Climate Change: Mean Annual Wave Climate
Period	Storms >5'	Storms > 11'	Hours >11'
1942-1945	30.7	3.3	64.0
1945-1950	33.5	4.0	57.4
1950-1955	33.0	3.2	42.6
1955-1960	38.4	3.8	49.6
1960-1965	33.2	4.0	40.6
1965-1970	32.2	7.0	117.2
1970-1974	26.0	6.8	122.5

The number of Atlantic Coast storms that produce waves that rework sands on the beach surface (waves > 5') change little between 1942 and 1974. However, the mean annual number of storms that produced waves large enough to overtop the beach and move sand and water inland (waves >11') has doubled as has the number of hours per year with waves greater than 11 feet.