MIAMI — Tropical Storm Imelda formed Sunday and is expected to become a hurricane on a forecast track that could take it away from the U.S. East Coast early this week.

The storm was causing disruption in the Bahamas and Cuba on Sunday, and a tropical storm watch was posted in parts of Florida. Meanwhile, Hurricane Humberto weakened very slightly but remained a strong Category 4 storm in the Atlantic, threatening Bermuda.

At about 8 p.m. EDT, Imelda was about 30 miles southeast of the northwest Bahamas and about 355 miles southeast of Cape Canaveral in Brevard County, Florida, the National Hurricane Center in Miami said. It was headed north at 9 mph and its maximum sustained winds were 40 mph.

The center said the system was expected to move across the central and northwestern Bahamas Sunday and turn east-northeastward, away from the southeastern U.S., by the middle of the week. A tropical storm watch could be required in Bermuda later in the day, forecasters said, and swells could reach the U.S. East Coast today.

— The Associated Press