A tropical storm watch stretches along the coast from Edisto Beach, S.C., to the South Santee River. The hurricane center said those elsewhere along the southeast coast of the United States should also keep an eye on Chantal. Chantal is expected to track slowly to the north and then northwest and move onshore in South Carolina by Sunday morning.

Chantal is the third named storm of an already active season and is forecast to bring "heavy rainfall" that carries an "elevated risk of flash flooding."

Tropical Storm Chantal formed on Saturday as it slowly moved in the Atlantic toward the Carolinas, according to the National Weather Service.