(Reuters) - Hurricane Ophelia strengthened off the Azores islands in the northern Atlantic Ocean on Saturday and was expected pass to the south of the archipelago later in the day before taking aim at the British Isles, the U.S. National Hurricane Center said.
It said Ophelia, rare for its location and a powerful Category 3 storm with top sustained winds of 114 miles per hour (185 km/h), was the sixth major hurricane of the Atlantic season.
"Ophelia is expected to reach the British Isles as a powerful extra-tropical cyclone with hurricane force winds," he Miami-based hurricane center said. "Dissipation is forecast in about four days after the system moved over these Isles."
(This version of the story corrects headline and first paragraph to drop erroneous reference to hurricane's formation)
(Reporting by Tom Brown; Editing by Bill Trott)