Tropical cyclones affect the South Carolina coast on an infrequent basis, but do provide significant influence annually through enhanced rainfall inland during the summer and fall months. Depending on the storm's intensity and proximity to the coast, tropical systems can be disastrous. The major coastal impacts from tropical cyclones are storm surge, winds, precipitation, and tornadoes. Hurricanes are the most intense warm season coastal storms and are characterized by windspeeds exceeding 64 knots (74 miles per hour) and central pressure usually lass than 980 millibars (mb) (28.94 inches of mercury). Less intense, but more frequent, are tropical storms (winds over 34 knots and under 64 knots: greater than 980 mb central pressure) and tropical depressions (winds under 34 knots).
Winds are usually the most destructive force associated with tropical cyclones, particularly inland. Strong winds, resulting from the low central pressure and forward movement, also combine to result in significant ocean rise and wave action. This resulting water rise, known as the storm surge, plagues coastal inlands and low-lying inland areas as these storms make landfall. Due to the low central pressure of a hurricane, a 100 mb drop in ocean surface pressure results in an increase of elevation of the ocean of about 1 meter (Smith, 1994).
Hurricane Hugo: Hugo crossed into South Carolina coast near the Isle of Palms on September 22, 1989. Surface winds were recorded at 138 miles per hour, with gusts of 160+ miles per hour. The National Weather Service at Charleston recorded a minimum barometric pressure of 27.85 inches. Damage to coastal and inland properties, utilities, agriculture, timber and commerce exceed $6 billion. 50-70,000 people were left homeless and 26 people were killed.
Hurricane Gracie: On September 29, 1959, Gracie made landfall between Charleston and Savannah, Georgia. Winds reached 140 mph and tides reached 8 ft. Damage was estimated at $20 million (1959 dollars), and seven lives were lost.
Hurricane Hazel: Hazel caused $27 million (1954 dollars) in damage on October 14, 1954 after moving parallel to the coast and making landfall near Little River South Carolina. Winds reached 106 mph and tides greater than 16 feet at Myrtle Beach. The heaviest damage in South Carolina was from Pawleys Island northward.
August 27, 1893 Hurricane: This un-named storm was the most deadly hurricane in South Carolina's history. This storm struck near Savannah, Georgia causing extensive flooding along the lower South Carolina coast. Winds of 120 miles per hour were measured at Charleston and Beaufort. More than 2,000 people drowned and damage estimates exceed $10 million (1893 dollars).