CNN
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Heavy rain and gusty winds are hitting parts of the Carolinas Monday morning as a system that could potentially become Tropical Storm Helene moves closer to the South Carolina coast.

The system was located about 100 miles east of Charleston, South Carolina, with tropical storm force winds of 50 mph Monday morning. Tropical storm warnings are in effect for coastal areas of the Carolinas.

But it is still being called Potential Tropical Cyclone Eight because it is not yet organized enough to be called a tropical or subtropical storm. The system still has a medium chance of doing so before it makes landfall Monday afternoon, but time is running out.

By Monday morning, heavy rains had already hit eastern parts of the Carolinas, prompting flash flood warnings. At the same time, strong winds were blowing along the coast, causing rough seas.

The center of a system is typically where the strongest winds and heaviest rain fall, but that is not the case for Potential Tropical Cyclone Eight. Most of the system’s heaviest rain and winds are far from the poorly defined center, satellite imagery shows.

This means the system will likely make landfall in South Carolina – between Charleston and Myrtle Beach – but southern North Carolina will be most impacted.

The biggest threat from the storm will be flooding rain.

Areas near the North Carolina-South Carolina border — including Wilmington, North Carolina — are at a Level 3 of 4 risk for rainfall-related flooding Monday, the Weather Prediction Center said. A much larger Level 2 of 4 risk area includes most of North Carolina and northern South Carolina. Flash flooding is likely, especially for any area that receives multiple heavy rains.

These areas will see between 4 and 8 inches of rain Monday night, but parts of extreme southern North Carolina could see double-digit rainfall.

In addition to heavy rain, the system could also produce a few tornadoes in eastern North Carolina on Monday. Storm surge of up to 3 feet is possible from the northern coast of South Carolina to the southern portions of the Outer Banks of North Carolina and onshore Monday afternoon. “Hazardous” marine conditions will persist throughout the day, the National Weather Service warned.

The system’s winds will quickly weaken as it moves inland across South Carolina late Monday and Monday night. Rain will continue across parts of the Carolinas and reach more of the mid-Atlantic on Tuesday, but the system is expected to dissipate by midweek.

The Carolinas received 6 to 12 inches of rainfall from Debby in early August, causing flash flooding near Charleston, South Carolina.

If the system secures a name on Monday, it will be the first named storm to make landfall in South Carolina since Ian made landfall as a Category 1 hurricane in 2022. It will also be the fourth named storm to make landfall in the U.S. this hurricane season.

CNN meteorologist Elisa Raffa contributed to this report.