As the 2014 Atlantic hurricane season begins to heat up this summer so does the ocean surface in the equatorial Pacific, and that’s good news for South Carolina.
The warming in the Pacific, known as El Nino, impacts weather patterns worldwide. In terms of hurricanes, “El Nino is our friend,” said Hope Mizzell, state climatologist with the S.C. Department of Natural Resources.
In the past eight El Nino summers – 1982, 1986, 1987, 1991, 1994, 1997, 2002 and 2009 – no hurricane has so much as sniffed the South Carolina coast. Gordon in 1994 did hit hurricane strength briefly as it did an odd loop out in the Atlantic off the state before coming ashore several days later as a tropical depression that simply brought much-needed rain.
The sea surface in the equatorial Pacific has slowly been warming in recent months. Most forecasts have the temperatures hitting weak to moderate El Nino levels in August.
The El Nino tends to create wind shear over the tropical Atlantic that suppresses hurricane formation in systems coming off Africa, Mizzell said. Most of the storm systems that have impacted South Carolina during past El Nino years emerged from the Gulf of Mexico.
As hurricane season hits its typical August and September peak in South Carolina, the slowly strengthening El Nino is comforting. But, like all historical weather patterns, it’s not a sure thing. Already, a system that formed off Africa this week seems to be bucking the trend.
Also, even weak tropical systems can cause serious problems. In 1994, Tropical Storm Beryl had weakened to a tropical depression as it moved through Georgia from the Gulf of Mexico, but it packed enough moisture to cause the worst flooding in 60 years on the Saluda River in the South Carolina mountains.
In 2002, Kyle formed in the central Atlantic, did a couple of loops, then hugged the S.C. coast at tropical storm strength for a destructive day. It tossed out an F2 tornado that destroyed 28 structures and damaged another 78 in Georgetown County, injuring eight people. Serious flooding occurred as far inland as the I-95 corridor.
While El Nino usually means fewer hurricanes form in the Atlantic, “there’s no correlation between the number that form and the number that make landfall.” Mizzell said. And it only takes one hurricane hitting the coast to cause major damage. For instance, only four hurricanes caused damage in 1992, when El Nino conditions were weakening in the Pacific. One of those, Andrew, devastated South Florida and Louisiana.
Despite strolling into the heart of hurricane season with our friend El Nino, “we always need to be prepared,” Mizzell said.