Grand Bahama residents have been evacuating from its predicted path.
The storm surge could be as high as 15ft (4.6m), officials warned.
Authorities closed some airports in the outlying islands, but the main international airport remains open on Sunday.
The storm was about 35 miles east of the Bahamas' Great Abaco Island, moving westward at 8mph (13km/h) with maximum sustained winds of nearly 175mph (280km/h), putting it among the most dangerous in recent history.
The core of the hurricane was expected to move over the island soon, and continue near or over Grand Bahama later on Sunday and Monday.
After hitting the Bahamas, it was expected to move up the US coast, grazing Florida, which had expected a direct hit but appeared to have been spared the worst by a change in the storm's path.
BBC
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