Tropical Storm Debby Projected to Bring ‘Historic’ Flooding to South Carolina

Tropical Storm Debby Projected to Bring ‘Historic’ Flooding to South Carolina

The National Weather Service’s Charleston office has issued several warnings about Tropical Storm Debby’s potential to bring “historic” rainfall to coastal South Carolina. The storm is projected to move through Florida and Georgia early on August 5 before slowing, and possibly stalling, over coastal South Carolina by midweek.

According to the most recent NWS forecast, Debby could unload 10-20 inches of rain across the region with localized amounts surging to as high as 30 inches. Meteorologist Ron Morales from NWS’ Charleston office highlighted the severity of the situation, stating, “We’re looking at rainfall values … two to four times the entire month’s average rainfall in just a few days.”

State of Emergency Declared

In anticipation of the storm, Governor Henry McMaster has declared a State of Emergency. He urged residents in potentially affected areas to start making preparations and plans for prompt action if required. For weathering the storm, residents can access helpful resources online at hurricane.sc.

Forecasts suggest that coastal South Carolina may start feeling Debby’s effects as early as August 5, and the storm could persist for several days. Morales expressed concerns over model readings, indicating that the effects of the storm, particularly heavy rainfall, and flooding, could linger through August 9 or possibly even longer.

‘Thousand-Year Flood’ Comparison

The current predictions liken Debby to an October 2015 storm system, which caused what is colloquially termed the “Thousand-Year Flood.” The system precipitated 15-20 inches of rain with localized amounts reaching up to 25 inches. The event entirely inundated communities, burst dams, claimed 19 lives, and provoked a presidential disaster declaration.

However, the impact of Debby could be more significant as the storm is expected to affect major city areas where a larger population resides. Morales provided a perspective on the storm’s rainfall combined with the duration of the event, stating that it has around a 0.1 to 0.2 percent chance of occurring in any given year.

Storm Surge and Wind Threats

Alongside the risk of rain, the NWS forecast on August 4 indicated that Debby could also bring powerful winds and up to 4 feet of storm surge to near-coastal communities like Charleston. This surge could cause minor to moderate beach erosion across the coast, flood streets, and other infrastructures.

Preparations Ahead of Debby’s Arrival

In response to the impending storm, the city of Charleston has activated its flood mitigation plan and started distributing sandbags. By August 4, about 3,400 sandbags had already been handed out. The city has planned for widespread road closures due to flooding and updated information on street closures can be found on the city’s official website.

In addition to Charleston, county officials in other low-lying areas are advising residents to consider evacuating ahead of the storm. To provide free parking during the storm, some county parking garages will open, and a general population pet shelter will be available throughout the storm’s duration.

Climate Change Link to Slowing Storms

The National Oceanic and Atmospheric Administration (NOAA) reports that tropical storms like Debby slowing down and stalling after landfall is becoming increasingly common, leading to disastrous flooding. NOAA’s Geophysical Fluid Dynamics Lab expressed that though more research needs to be done, there is evidence suggesting a link between the slowing speed of hurricanes and human-caused climate change.