FLAGLER BEACH, Fla. — Tropical Storm Ophelia strengthened into a hurricane again today as forecasters said that a landfall somewhere along the southeast Atlantic coast appeared more likely.

Forecasters have urged residents from the Georgia-Florida border to the Carolinas to a keep close watch on Ophelia's path. A hurricane watch was issued from north of the Savannah River in South Carolina to Cape Lookout in North Carolina, meaning hurricane-force winds of at least 74 mph were possible by Sunday evening.

A hurricane hunter flying through Ophelia measured top sustained winds of 80 mph. It could strengthen a bit before an expected Monday landfall, said Eric Blake, a meteorologist at the National Hurricane Center.

"Almost every (computer) model indicates a United States landfall," he said. "It's time to make those preparations."

At 11 a.m. EDT (8 a.m. PDT), Ophelia was centered about 220 miles east-southeast of Charleston, S.C., and about 255 miles south-southwest of Cape Hatteras, N.C. It was moving northeast near 3 mph, but was expected to head back toward the coast Sunday.

Ophelia seemed to be on a path that would spare Florida, which has been hit by two hurricanes this year and six in the past 13 months. Many residents have already stocked up on batteries, water and nonperishable food.

George Curovic, general manager of Manny's, said his restaurant drew big crowds through last year's season because it was one of few in the Flagler Beach area with power. This time it's different, he said.

"Now they're getting away. I think they've seen too much damage, too much death," Curovic said. "All it takes is one tidal wave to wipe this place out."

Even as it lingered offshore, Ophelia sent waves crashing onto beaches and stirred up strong wind gusts.

Two other tropical storms, Nate and Maria, posed no threat to land as they weakened moving into cooler waters of the north Atlantic.

The Atlantic hurricane season began June 1 and ends Nov. 30. Peak storm activity typically occurs from the end of August through mid-September.