Heavy rainfall and gusty winds are hitting portions of the Carolinas Monday morning as a system that could become Tropical Storm Helene draws closer to the South Carolina coast.

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

But it’s still being called Potential Tropical Cyclone Eight because it hasn’t become organized enough to be dubbed a tropical or subtropical storm. The system still has a medium chance of doing so before making landfall Monday afternoon, but it’s running out of time.

Heavy rain was already drenching eastern parts of the Carolinas Monday morning, triggering flash flood warnings, while strong winds lapped against the coast, churning up rough seas.

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

This means that while the system will likely make landfall in South Carolina – between Charleston and Myrtle Beach – southern North Carolina will endure most of its significant impacts.

Flooding rain will be the storm’s most significant threat.

Areas near the North Carolina-South Carolina border – including Wilmington, North Carolina – are under a level 3 of 4 risk of flooding rainfall Monday, according to the Weather Prediction Center. A much larger level 2 of 4 risk area encapsulates most of North Carolina and northern South Carolina. Flash flooding is likely, especially for any area that gets multiple rounds of heavy rain.

Widespread rainfall totals of 4 to 8 inches will drench these areas through Monday night, but totals could reach double digits for parts of extreme southern North Carolina.

In addition to heavy rain, this system could also produce a few tornadoes in eastern North Carolina Monday. Up to 3 feet of storm surge is possible from the northern South Carolina coast into southern portions of North Carolina’s Outer Banks through landfall Monday afternoon. “Dangerous” marine conditions will persist throughout the day, the National Weather Service warned.

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

The Carolinas were deluged by 6 to 12 inches of rainfall from Debby in early August that created a flash flood emergency near Charleston, South Carolina.

If this system manages to grab a name Monday, it’ll be the first named storm to make landfall in South Carolina since Ian came ashore as a Category 1 hurricane in 2022 and the fourth named storm to make landfall in the US this hurricane season.

CNN Meteorologist Elisa Raffa contributed to this report.