US: Potential Tropical Cyclone 8 tracking northwestward across North Atlantic Ocean towards South Carolina as of late Sept. 15

Potential Tropical Cyclone 8 is tracking northwestward across the North Atlantic Ocean towards South Carolina late Sept. 15. As of 23:00 EDT, the system's center of circulation was approximately 200 km (125 miles) east-southeast of Charleston, South Carolina.

Forecast models indicate that the storm will strengthen slightly and make landfall over South Carolina, US, southwest of Myrtle Beach, late Sept. 16. The system is forecast to weaken rapidly and transition into a post-tropical cyclone with tropical depression strength as it tracks north-northwestward across eastern South Carolina through early Sept. 17 and across western North Carolina through early Sept. 18. The storm is likely to make a sharp turn to track eastward over western North Carolina and dissipate late Sept. 18.

As of late Sept. 15, authorities have issued the following watches and warnings:

• Tropical Storm Warning: Edisto Beach, South Carolina, northward to Ocracoke Inlet, North Carolina

Authorities will likely update and extend the coverage of the weather advisories over the coming hours and days as the storm approaches.

The storm is forecast to bring rainfall of 7.5-15 cm (3-6 inches), with isolated totals around 20 cm (8 inches) across northern and northeast South Carolina along the North Carolina Coastal Plain. Rainfall of 5-10 cm (2-4 inches) is forecast across the rest of North Carolina and much of Virginia. This rainfall could lead to isolated to scattered flash and urban flooding and minor river flooding. Isolated tornadoes may occur across the eastern Carolinas Sept. 16.

The combination of a storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach up to 0.3-0.9 meters (1-3 feet) from the South Santee River in South Carolina to Oregon Inlet in North Carolina and the Neuse, Bay, Pamlico, and Pungo rivers in North Carolina. Swells are forecast to affect portions of the coast of the southeastern US over the coming days. These swells are likely to cause life-threatening surf and rip current conditions.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

Inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.