Tropical Storm Isaias was set to regain hurricane strength Monday before slamming into the US eastern seaboard, bringing life-threatening storm surges to North and South Carolina.
The storm, currently 90 miles (145 kilometers) off the coast of Georgia, was packing sustained winds of 70 miles per hour, with wind speeds predicted to increase during the day.
Isaias is forecast to "make landfall tonight as a hurricane... expected to bring strong winds and heavy rainfall," the National Hurricane Center said, adding the storm would likely hit close to the border between North and South Carolina.
Storm surges could generate water three to five feet above ground level.
The storm will then track up the East Coast, with heavy rainfall expected to cause flash flooding through the mid-Atlantic states and bringing storm-force winds to Washington, Philadelphia and New York on Tuesday.
Residents in flood-prone areas "should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions," the National Hurricane Center said.
In the hurricane warning zone, "preparations to protect life and property should be rushed to completion," it added.