Tropical Storm Ophelia re-strengthened Friday as it headed across the Atlantic Ocean and took aim at the Caribbean, U.S. forecasters said.
The U.S. National Hurricane Center said Ophelia was expected to start weakening again by Saturday night, however.
It posed no apparent threat to land and energy interests in the far-off Gulf of Mexico were unaffected.
At 5 p.m. ET, Ophelia was about 540 miles east of the Caribbean's Leeward Islands and its top sustained wind speeds had increased to 60 miles per hour, the Miami-based hurricane center said.
It said the storm's resurgence, after its maximum sustained wind speeds dropped to about 40 miles an hour earlier Friday, was expected to be short-lived.
But some slight strengthening was possible by Wednesday, if there is a decrease in the strong wind shear that has plagued Ophelia since it formed earlier this week.
On its current northwestward track, the core of Ophelia and its heaviest rain squalls were expected to pass well off the northeast coast of Puerto Rico on Sunday afternoon.