FORT LAUDERDALE, Fla. — While new Tropical Storm Karl emerged in the northwestern Caribbean on Tuesday afternoon, Hurricane Igor has bulked up again, now packing sustained winds of 145 mph, Category 4 strength.

Igor is forecast to become stronger yet, to 150 mph, over the next 12 hours as it aims generally toward Bermuda. That would match the system’s maximum wind speed on Monday.

Although Igor should gradually weaken by Wednesday, it still is projected to arrive near the small island nation on Sunday as a major hurricane.

At 5 p.m. EDT on Tuesday, Igor was in the Atlantic about 655 miles east of the Leeward Islands, crawling northwest at 8 mph.

While it could generate large swells along Florida later this week, Igor is expected to remain well clear of the U.S. East Coast. Under the latest forecast track, it would be about 1,100 miles due east of Miami on Friday.

Karl, the 11th named storm of the season, is projected to hit Mexico twice: the Yucatan on Wednesday and the mainland on Friday. It is not forecast to grow into a hurricane.

At 5 p.m., Karl was about 270 miles east of Chetumal, Mexico, moving northwest at 15 mph with sustained winds of 40 mph.

At 5 p.m., Hurricane Julia was about 405 miles northwest of the Cape Verde Islands, lumbering northwest at 9 mph with sustained winds of 85 mph. It is forecast to remain at sea without threatening land.