Millions of people living along the Gulf Coast are being urged to make sure preparations are in place as the next tropical threat to the U.S. brews in the Caribbean.

Tropical storm warnings were issued for the coast of South Carolina and North Carolina, according to the hurricane center. The potential system is expected to bring a risk of scattered flash and urban flooding, in addition to minor river flooding across parts of the region.

The National Hurricane Center says an area of low pressure in the Caribbean now has a high chance of developing this week, and millions of people living along the Gulf coast are being urged to prepare for the possibility of a tropical storm or hurricane impacting the region.