This satellite picture shows Hurricane Florence approaching the island of Bermuda. NOAA/NHC image

After gaining hurricane status early on Sunday, the storm's maximum sustained winds were at 90 mph, easily making it a Category 1 hurricane, the least powerful on the Saffir-Simpson scale, the U.S. National Hurricane Center said.

Forecasters predicted Florence would intensify to Category 2 as it passed Bermuda on Monday morning. Category 2 hurricanes have top sustained winds of at least 96 mph and are capable of moderate damage.

Bermuda Weather Service Director Mark Guishard said winds of around 100 mph were expected early on Monday. Tropical storm-force winds extended up to 260 miles and were already affecting the island, the hurricane center said.

Florence, the second hurricane of the 2006 Atlantic season, was 185 miles south-southwest of Bermuda at 5 pm and moving toward the north at 13 mph, according to the hurricane center.

The hurricane was expected to stay away from the North American mainland, but was creating risky surf along parts of the eastern United States, according to US forecasters.

Florence's approach prompted Bermuda's government to issue a hurricane warning, telling the 22-mile-long island's 63,000 residents they should rush to complete preparations.

WINDS AND WAVES

Bermuda could experience 6- to 8-foot storm surges and battering waves as Florence passes, as well as 5 to 8 inches of rain, forecasters said. Its South Shore beaches were already taking a severe pounding.

Government leaders called up 200 troops of the Bermuda Regiment and placed 250 more on standby for possible deployment after the storm. A shelter opened at midday, although most Bermudans were expected to weather Florence at home.

Hundreds of emergency service workers on the resort island that is also an international finance center were on standby.

Tourists had been issued emergency plans, Acting Police Commissioner Roseanda Young said. Guests at one low-lying hotel moved to another on higher ground.

The electricity company warned of possible prolonged power outages throughout the island.

Acting Premier Ewart Brown said Bermuda was no stranger to hurricanes after Hurricane Emily nearly 20 years ago and 2003's Hurricane Fabian, which killed four and did about $500 million damage.

"It is my genuine belief that, should we sustain serious damage in the wake of this storm, we will rally together once again to ensure that our island is up and running as swiftly as possible," Brown said.

Florence was a big storm with large ocean swells and was causing dangerous surf conditions in the Bahamas, Northern Leeward Islands, Virgin Islands, Puerto Rico and Hispaniola.

Local forecasters in Massachusetts issued a high surf advisory through Tuesday evening as swells from Hurricane Florence reached Massachusetts and Rhode Island beaches.