Hurricane Lee was churning west-northwest in the tropical Atlantic Ocean and was expected to bring dangerous surf and rip currents to the U.S. East Coast from Sunday night into next week, the U.S. National Hurricane Center said.

The storm, about 270 miles (535 km) northeast of the northern Leeward Islands, should pass north of Puerto Rico, the U.S. Virgin Islands and other Caribbean islands.

Lee was packing winds of 110 mph (175 kph), the forecaster said. It weakened to a Category 2 storm from a Category 3 on Sunday when its wind speed dropped below 111 miles per hour (178 kph).

The storm was slowly moving west-northwest at 8 mph (17 kph) and the agency said "some strengthening" was possible.

Swells were affecting portions of the British and U.S. Virgin Islands, Puerto Rico, Hispaniola, Turks and Caicos, the Bahamas and Bermuda.

Sunday appeared to be just another hot and humid late summer day in Puerto Rico's capital San Juan where people walked by the beach or exercised, and businesses were open.

"So far it's just a normal day," Kelly Herrera, a guest service agent at the Condado Vanderbilt Hotel on San Juan's beach front, said in a phone interview.

Herrera said people were advised to stay away from the water in preparation for swells and dangerous rip currents generated by the storm.

The National Weather Service's office in Puerto Rico forecast waves of 6 to 10 feet, possibly higher, in some coastal areas.

(Reporting by Maria Caspani, Editing by Cynthia Osterman)