By Tom Brown
MIAMI (Reuters) - A trio of potentially dangerous storms swirled over the Atlantic Ocean on Tuesday as Tropical Storm Karl formed in the Caribbean on a path that could take it over oil-production facilities in Mexico's Bay of Campeche.
The threat posed by Karl, which forecasters say will enter the oil-rich Gulf of Mexico, came as Tropical Storm Julia grew in the far eastern Atlantic into the fifth hurricane of the Atlantic storm season and Hurricane Igor remained a dangerous Category 4 storm.
Neither hurricane posed an immediate threat to land or energy interests, but Igor could threaten Bermuda by the weekend.
Karl, located about 270 miles east of Chetumal, Mexico, had maximum sustained winds of about 40 miles per hour on Tuesday afternoon, the U.S. National Hurricane Center said.
The 11th named storm of the Atlantic hurricane season was expected to churn west-northwest across Mexico's Yucatan Peninsula on Wednesday and then plow into the Bay of Campeche in the southwest Gulf of Mexico before moving inland in central Mexico.
The system was expected to miss key U.S. oil and natural gas rigs in the northern part of the Gulf of Mexico. But forecasters said the storm, which some computer models showed becoming a Category 1 hurricane, could hit Mexican oil interests.
Mexico's state-run oil giant Pemex said it had not yet taken any action ahead of the storm but it was monitoring it closely.
Julia reached hurricane status and then continued to strengthen, with top sustained winds of 85 miles per hour. It was moving slowly west-northwest away from the Cape Verde Islands on Tuesday afternoon, the Miami-based hurricane center said.
Julia was a Category 1 hurricane on the five-step Saffir-Simpson scale of hurricane intensity, forecasters said. Its projected path would keep it out to sea.
Julia could strengthen slowly over the next two days, forecasters said. But as it gets closer to the more powerful Igor, strong upper-level winds flowing out from Igor could shear off and weaken Julia.
Farther west in the Atlantic, Hurricane Igor was about 655 miles east of the northern Leeward Islands with maximum sustained winds at 145 mph, the center said.
Igor had been moving west on Monday but curved to the west-northwest on Tuesday. It was expected to curl around to the north in three or four days, and eventually turn east. Its projected path would keep it away from the North American coast but forecasters said it was too soon to rule out a hit.
"Igor is a Category Four hurricane on the Saffir-Simpson hurricane wind scale. some fluctuations in intensity are possible during the next 48 hours, but Igor is expected to remain a very powerful hurricane through Thursday," the hurricane center said.
Igor was expected to weaken before nearing the British territory of Bermuda on Saturday.
Ocean swells generated by Igor were expected to begin affecting Puerto Rico and the Virgin Islands late on Tuesday and Wednesday, causing life-threatening surf and rip current conditions, the hurricane center said.
Computer models kept both storms in the Atlantic and far away from the Gulf of Mexico.
Most forecasters predicted the 2010 Atlantic hurricane season would be extremely active. The season runs from June through November and has already brought 10 tropical storms, with five growing into hurricanes. Three of those -- Danielle, Earl and Igor -- have reached Category 4 strength.
(Editing by Cynthia Osterman)