At 5 p.m. (2100 GMT), Ophelia's center was about 80 miles (128 km) east-northeast of Cape Canaveral, Florida. The storm was nearly stationary all day long and was expected to meander around the same spot for the next few days, forecasters at the National Hurricane Center said.

Ophelia was expected to alternately weaken and strengthen as it hugged the Florida coast, but could still grow into a weak hurricane, with winds of at least 74 mph (118 kph).

Tropical storm warnings, alerting residents that the storm could hit them within 24 hours, were posted for an 85-mile (135 km) stretch of shoreline from Cocoa Beach to Flagler Beach in northeast Florida.

Forecasters said Ophelia could dump 3 to 8 inches (8 to 20 cm) of rain on parts of central and north Florida and southeast Georgia, and trigger dangerous rip tides all along the southeastern coast of the United States.

But the air currents that guide the path of tropical storms were so weak that forecasting models disagreed greatly on Ophelia's most likely track.

One or two nudged it west across Florida and into the northern Gulf of Mexico, the region stricken by catastrophic Hurricane Katrina. Others had it looping slowly eastward and away from the United States.

The individual models flip-flopped all day long, so the hurricane center issued a compromise forecast: Ophelia is going to stay put for a few days.

In the mid-Atlantic, Hurricane Nate strengthened as it neared the British colony of Bermuda. It had top winds of 85 mph (140 kph) and was expected to pass just south of the island of 65,000 people on Thursday.

Nate was centered 200 miles (325 km) south-southwest of Bermuda and was expected to pound the island with battering waves.

"I think we're unlikely to sustain a lot of damage from Hurricane Nate," said Elizabeth Harris, a meteorologist with the Bermuda Weather Service. "It's just really going to brush past."

The island, a resort and banking center, rarely sees much damage from storms of Nate's caliber.

"We build all of our houses out of concrete blocks," Harris said.

Farther north in the Atlantic, Hurricane Maria was a danger to ships but did not threaten land. It was about 875 miles (1,410 km) east-northeast of Bermuda and still had top winds of 80 mph (130 kph). Maria was moving over colder water that was expected to siphon its strength and break it apart on Thursday.