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Islanders crowded stores Friday to buy generators, bottled water and other emergency supplies as Tropical Storm Florence chugged through the open Atlantic on a path toward Bermuda.

Florence is expected to reach hurricane strength by the time it reaches the tiny British territory on Monday, according to forecasters at the U.S. National Hurricane Center in Miami, though it was too early to tell whether it will make a direct hit.

"Even if the center misses Bermuda by a couple hundred miles, this is a very large storm so there's likely to be some effect," said Mark Willis, a meteorologist at the center. "If not the strong winds, there will definitely be some rough surf."

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Bermuda issued a hurricane watch on Friday and urged the territory's 65,000 residents to take precautions.

"The public is encouraged to stock up on normal hurricane supplies and to secure their homes, lawn furniture and any other loose items which could be affected by high winds," Public Safety Minister Derrick Burgess said.

A line of customers snaked through a hardware store in Hamilton, which sold out of lanterns by Friday afternoon. Carolyn Wagensveld, who was stocking up on candles, said she arrived from Toronto on Thursday to take a teaching job and was looking to locals for guidance.

"I'm a little nervous but the islanders don't seem to worried, so I'm not too worried," she said.

Another customer, Colette Lightbourne, said storm preparations were a familiar routine.

"It's happened so many times before, we're used to it," she said. "Everyone will be buying their supplies today and clearing their yards."

The storm was expected to veer away from the U.S. coast as it turns north toward Bermuda, but forecasters said its large size could also create high surf and rip currents along parts of the eastern U.S. coast. The storm had sustained winds of 50 mph, and tropical storm force winds extended up to 375 miles from Florence's center.

The hurricane center said in an advisory that the storm "appears ready to strengthen."

Early Friday evening, the storm was centered about 650 miles south-southeast of Bermuda and was moving northwest at 14 mph.

"We don't know exactly how strong it's going to get, but this is something to which people should pay close attention," said Lou McNally, of the Bermuda Weather Service. "Preparations should be well under way."

Bermuda, a wealthy island chain 640 miles east of the U.S. coast, requires newly built houses to withstand sustained winds of 110 mph. It also has a sturdy infrastructure with many of its power and phone lines underground.

Hurricane Fabian killed four people when it struck in 2003 as the strongest storm to hit Bermuda in 50 years. Fabian, a Category 3 hurricane with 120 mph winds, tore the roofs off several homes and left many of Bermuda's famed golf courses in ruins.

Florence follows on the heels of Tropical Storm Ernesto, which was briefly the season's first hurricane before weakening and drenching the U.S. East Coast last week. The storm was blamed for nine deaths in the United States and two in Haiti.

Florence developed in the peak of hurricane season over warm Atlantic water, the source of energy for storm development this time of year. While those waters are warm enough to spur storm intensification, forecasters said they are not as warm as last year's storm season, which had a record 28 named storms and 15 hurricanes, including Katrina.

The 2006 Atlantic hurricane season has not been as rough as initially feared. The National Hurricane Center lowered its forecast in August to between 12 and 15 named storms and seven to nine hurricanes.

Click here to track Tropical Storm Florence.