The third named storm of the 2018 hurricane season formed in the Atlantic on Sunday off the coast of North Carolina.
The National Hurricane Center said Chris could gain strength and become a hurricane by Monday, but it is expected to stay offshore and eventually turn away from the U.S. coast.
"Swells generated by Chris are expected to increase and affect portions of the coasts of North Carolina and the Mid-Atlantic states into early next week," the NHC said.
Chris' predecessor, Tropical Storm Beryl, continued to move toward the eastern Caribbean. Forecasters predicted that even though the storm is losing strength, it could bring significant rain to the islands still trying to recover from the devastating 2017 hurricane season.
Puerto Rico Governor Ricardo Rossello warned of more power outages as the storm passes over the island Monday. More than 1,500 homes are without power nine months after Hurricane Maria made landfall. He also urged the thousands without sturdy roofs to move in with relatives or into government shelters.
NHC said Beryl was packing winds of up to 75 kilometers per hour late Sunday.
Forecasters predict Puerto Rico could get 5 to 8 centimeters (2-3 inches) of rain and experience 15 to 25 kilometers (9-15 miles) an hour winds from Beryl.