South Carolina Hurricane Climatology
A tropical cyclone is a warm core, non-frontal, low pressure system that develops over tropical or subtropical waters and has an organized cyclonic (counterclockwise) circulation. On the basis of the sustained (1-minute average) wind speed near the center of the storm, tropical cyclones are classified as: Tropical Depression, less than 34 knots (less than 39 miles per hour); Tropical Storms, 34 to 63 knot winds (39-73 miles per hour); or Hurricanes, with winds greater than 63 knots (greater than 73 miles per hour). Only tropical storms and hurricanes are assigned names.
The Atlantic tropical-cyclone basin is one of six in the world and includes much of the North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico.
The official Atlantic hurricane "season" begins June 1 and ends November 30 each year; however, the season can begin and has begun earlier and ended later.
Early season tropical cyclones generally form in the western Caribbean Sea and the Gulf of Mexico. By the
end of June or in early July, the area of formation shifts eastward.
In late August, tropical cyclones form over a broad area of the eastern Atlantic, extending eastward to the area of the Cape Verde Islands off the coast of Africa. The period from about August 20 through about September 15 encompasses the maximum of these Cape Verde storms. Most Cape Verde storms cross-vast areas of the Atlantic Ocean before dissipating over the North Atlantic. Those, which do make landfall in the United States can be especially powerful.
By Mid-September, storm frequency begins to decline, the formative area retreats westward back to the Caribbean Sea and the Gulf of Mexico. Usually, by mid-November, tropical-cyclone occurrence in the North Atlantic has ceased.
Records of tropical-cyclone occurrences in the Atlantic tropical-cyclone basin are kept by the National Climatic Data Center in Asheville, North Carolina, in cooperation with the National Hurricane Center in Miami, Florida. Records are updated annually and are available from the National Climatic Data Center. For the 139-year period 1871-2009, a total of 1267 tropical cyclones were recorded in the Atlantic tropical-cyclone basin. For the years prior to 1969 when weather satellites were first used, the data most likely underestimates the number of tropical cyclones that went undetected over the Atlantic.
Historical Hurricanes in South Carolina
Hurricanes and tropical storms are irregular visitors to coastal South Carolina. In the period, 1901-2009, only 27 tropical cyclones have made landfall on the South Carolina coast. Of these, only eight were of Category 2 to Category 4 intensity. Since 1900, no Category 5 hurricanes have hit South Carolina. There have been two Category 4 hurricanes (Hazel, 1954, and Hugo, 1989) and two Category 3 hurricanes (September 17, 1945, and Gracie, 1959). It is possible that the "Great Storm of 1893" that struck the southern on coast on August 20 of that year was at least a Category 4 storm, but there was no way of accurately measuring tropical-cyclone intensity before 1900.
In the Colonial period tropical storms and hurricanes were known as "September gales," probably because the ones people remembered and wrote about were those which damaged or destroyed crops just before they were to be harvested.
One such storm that struck Charles Town on September 25, 1686, was "wonderfully horrid and destructive...Corne is all beaten down and lyes rotting on the ground... Aboundance of our hoggs and Cattle were killed in the Tempest by the falls of Trees..." The storm also prevented a Spanish assault upon Charles Town by destroying one of their galleys and killing the commander of the Spanish assault.
In autumn of 1700, "a dreadful hurricane happened at Charles Town which did great damage and threatened that total destruction of the Town, the lands on which it is built being low and level and not many feet about high water mark, the swelling sea rushed in with amazing impetuosity, and obliged the inhabitants to fly to shelter..." A ship, Rising Sun, out of Glasgow and filled with settlers had made port just prior to the storm's landfall. It was dashed to pieces and all on board perished.
Of a storm which passes inland along the coast September 7-9, 1854, Adele Pettigru Allston wrote from Pawleys Island, "The tide was higher than has been known since the storm of 1822. Harvest had just commenced and that damage to the crops in immense. From Waverly to Pee Dee not a bank nor any appearance of land was to be seen...(just) one rolling, dashing Sea, and the water was Salt as the Sea."
By 1893, major population centers could be telegraphically alerted to storms moving along the coast, but there were no warnings for the Sea Islands and other isolated areas. The "Great Storm of 1893" struck the south coast at high tide on August 28, pushing an enormous storm surge ahead of it and creating a "tidal wave" that swept over and submerged whole islands. Maximum winds in the Beaufort area were estimated to be 125 miles per hour, those in Charleston were estimated near 120 miles per hour. At least 2,000 people lost their lives, and an estimated 20,000-30,000 were left homeless and with no mean of subsistence. /p>
Hazel (October 1954) and Gracie (September 1959) have been the most memorable storms in recent years. Hazel,
a Category 4 storm, made landfall near Little River, S.C., with 106-miles per hour winds and 16.9 foot storm surge. One
person was killed and damage was estimated at $27 million.
Gracie, a Category 3 hurricane, made landfall on St. Helena Island and continued toward the north-northwest, maintaining hurricane strength for more than 100 miles inland. Heavy damage occurred along the coast from Beaufort to Charleston. Heavy rains caused flooding through much of the State and crop damage was severe.
Hugo (September 1989) made landfall near Sullivan's Island with 120 knot winds. It continued on a northwest track at 25-30 miles per hour and maintained hurricane force winds as far inland as Sumter. Hugo exited the State southwest of Charlotte, N.C., before sunrise on September 22. The hurricane caused 13 directly related deaths and 22 indirectly related deaths, and it injured several hundred people in South Carolina. Damage in the State was estimated to exceed $7 billion, including $2 billion in crop damage. The forests in 36 counties along the path of the storm sustained major damage.
From 1990 to 2009, South Carolina has only had three weak tropical cyclone landfalls along the coast: Tropical Storm Kyle (35 kts) in 2002, Hurricane Gaston (65 kts) and Hurricane Charley (70 kts) in 2004. During September 1999 Hurricane Floyd, a very large storm, came very close to the South Carolina coast, then made landfall near Cape Fear, North Carolina. Hurricane Floyd triggered mandatory coastal evacuations along the South Carolina coast. Heavy rain of more than 15 inches fell in parts of Horry County, S.C., causing major flooding along the Waccamaw River in and around the city of Conway for a month.
Saffir-Simpson Hurricane Scale
Category 1: Winds 74 to 95 miles per hour. Damage primarily to shrubbery, tree foliage, and unanchored mobile homes; no real damage to other structures.Some damage to poorly constructed signs. Minor pier damage; some small craft in exposed anchorages torn from moorings.
Category 2: Winds 96 to 110 miles per hour. Considerable damage to shrubbery and tree foliage, some trees blown down. Major damage to exposed mobile homes; no major damage to buildings; some damage to roofing materials of buildings; some window and door damage. Extensive damage to poorly constructed signs. Considerable damage to piers, marinas flooded. Small craft in protected anchorages may be torn from moorings.
Category 3: Winds 111 to 130 miles per hour. Foliage torn from trees, large trees blown down. Mobile
homes destroyed, some structural damage to small buildings; some damage to roofing materials of buildings; some window and door damage. Practically all poorly constructed signs blown down. Storm surges 9 to 12 feet above normal tide heights.
Category 4: Winds 131 to 155 miles per hour.Shrubs and trees blown down; all signs down. Complete destruction of mobile homes. Extensive damage to roofing materials, windows and doors. Complete failure of roofs on small buildings. Major damage to lower floors of near-shore structures due to flooding and battering by waves and floating debris.
Category 5: Winds greater than 155 miles per hour. Shrubs and trees blown down; all signs down. Extensive shattering of glass in windows and doors; complete failure of roofs on many residences and industrial buildings. Complete destruction of mobile homes; small buildings overturned or blown down; some complete failures of other structures.
SAFFIR/SIMPSON HURRICANE SCALE WITH CENTRAL BAROMETRIC PRESSURE RANGES
Tropical Weather Terminology
The Official Hurricane Season begins June 1 and ends November 30. Occasionally, tropical systems begin earlier and end later. A tropical cyclone is the general term for all cyclone circulations originating over tropical waters.
Watch and Warning Definition
||A moving area of thunderstorms over the tropics maintaining its identity for 24 hours or more.|
||Thunderstorms with a closed cyclonic surface circulation with winds up to 38 miles per hour.|
||Thunderstorms with a closed cyclonic surface circulation with winds 39 to 73 miles per hour.|
||A closed cyclonic surface circulation with sustained surface winds of 74 miles per hour or greater.|
||Issued for coastal areas when there is a threat within 48 hours.|
||Hurricane conditions expected within 36 hours or less.|
Remember, hurricanes produce life threatening winds, tornadoes, and other unforeseen dangers.
Be prepared to save property and lives.
Notable South Carolina Hurricanes
|August 28, 1893
||Landfall near South Carolina / Georgia border, winds estimated at over 120 miles per hour, loss of life estimated at more than 2,000.|
|July 14, 1916
||Landfall near Bulls Bay, South Carolina, winds estimated at over 80 miles per hour, slow-moving torrential rains produced eastern South Carolina's worst flood. Effingham, South Carolina recieved 13.25 inches of rain in 24 hours.|
|August 11, 1940
||Landfall near Beaufort, South Carolina, winds 105 miles per hour, loss of life 34. Beaufort, South Carolina received 10.84 inches of rain in 24 hours.|
|October 15, 1954
||"Hazel"- Landfall near South Carolina / North Carolina border, winds at Myrtle Beach reached 106 miles per hour, loss of life 1, oceanfront property from Pawleys Island, South Carolina northward destroyed. Storm surge 17 feet. Georgetown, South Carolina received 8.80 inches of rain in 24 hours.|
|September 29, 1959
||"Gracie"- Landfall at St. Helena Island, South Carolina. Marine Corps Auxilary Air Station recorded a gust of 138 miles per hour. Heavy flooding from 8 inches of rain (Walterboro, 8.30 inches in 24 hours).|
|September 21, 1989
||"Hugo"- Landfall at Isle of Palms, South Carolina with 138 miles per hour with gust over 160 miles per hour. Costliest storm in South Carolina history at over 6 billion dollars, 35 related fatalities, storm surge 20+ feet. Severe inland damage as winds gusted to 109 miles per hour at Shaw Air Force Base, Sumter, South Carolina.|