Hurricane Ophelia strengthened into a rare Category 3 hurricane Saturday as it continued on a path that was taking it south of the Azores.

The National Hurricane Center said Ophelia, the sixth major hurricane in the Atlantic so far this year, will then track toward Ireland and the U.K., which could have to deal with hurricane conditions by Monday.

Hurricane Ophelia had a distinct eye in satellite images on Saturday. Some of the Azores are visible to the north of the storm. (NASA image)

Ophelia is expected to transition to a non-tropical storm by that point, but it will remain powerful with hurricane-force winds, forecasters said.

Ophelia's winds were holding at 115 mph on Saturday afternoon, making it a Category 3 hurricane. "Ophelia is a quite intense and rare hurricane for its location in the northeastern Atlantic," the hurricane center said.

Hurricane center forecaster Eric Blake said that Ophelia is the first Category 3 storm that far east on record in the Atlantic.

Ophelia had picked up a lot of speed on Saturday. As of the 4 p.m. CDT advisory from the hurricane center it was located about 235 miles southeast of the Azores and was moving northeast at 28 mph.

The hurricane center said Ophelia should maintain that intensity today but could begin to slowly weaken by tonight or Sunday. It is expected to begin to transition into an extratropical storm by late Sunday or early Monday.

Despite that forecast for weakening, the hurricane center cautioned that "Ophelia is forecast to remain a powerful cyclone with hurricane-force winds as it approaches Ireland."

Ophelia is expected to continue on a northeast path today and pick up even more speed through Sunday.

On that track, the hurricane center said the center of the storm will pass to the south and southeast of the southeastern-most Azores through tonight.

Forecasters said tropical storm force winds could affect all the Azores through tonight, in part from Ophelia and in part from an approaching cold front.

The hurricane center said hurricane-force winds (74 mph and higher) will be possible in Ireland, with stronger winds expected over higher terrain.

And Ophelia's wind field is expected to widen once the storm loses its tropical characteristics and becomes extratropical. That could spread strong winds into the British Isles, the hurricane center said.

The center of the storm is forecast to reach Ireland and the U.K. in 48-60 hours, the hurricane center said, but those areas will feel its effects far beforehand.

Ireland's weather service, Met Eireann, raised a storm warning level from yellow to red for areas along the coast and said a wind warning will go into effect as the storm approaches.

Forecasters there said "severe winds" are expected, which could cause "structural damage and disruption" as well as dangerous seas.

In addition to Opehlia there's another potential storm brewing far to the south and west.

The National Hurricane Center was also monitoring Invest 92L near the Leeward Islands on Saturday afternoon.

It was not expected to develop over the next few days but could move into a more favorable are early next week. Forecasters gave it a 40 percent chance of becoming a tropical depression in the next five days.

Invest 92L is forecast to turn more to the north and recurve over the west-central Atlantic, which should keep it away from the U.S.

The Atlantic hurricane season ends on Nov. 30.