Some uncertainty surrounds the tracks of both storms. However, Humberto is likely to recurve out to sea, avoiding landfall. But forecasters believe the other system to the west, Invest 94L, the future Imelda, could strike the East Coast near the Carolinas.

As of Friday, Humberto has strengthened into a Category 1 hurricane with sustained winds of around 145 km/h (90 mph) and is forecast to intensify into a major hurricane. Imelda is a developing tropical system near Hispaniola that is expected to strengthen into a tropical storm hurricane.

Hurricane Humberto and a system that may become Tropical Storm Imelda in the coming days are swirling quite close to each other in the western Atlantic Ocean

Imelda will pose a danger of heavy rain, high winds and coastal flooding to the Southeast U.S. Meanwhile, Hurricane Humberto underwent rapid intensification on Friday, going from a tropical storm to a Category 4 hurricane in less than a day.

Hurricane Humberto is officially brewing in the Atlantic, but a currently unnamed disturbance could be a bigger threat to South Carolina.

Tropical Storm Humberto expected to strengthen into major hurricane. Will Florida be impacted? That's hard to predict. Here's why.

Two tropical systems may develop into the next named storms of the season over the next few days, the National Hurricane Center said.