CANCUN: Tropical storm Karl soaked parts of Mexico`s Yucatan Peninsula Wednesday and headed toward Gulf oil installations, as a rare duo of powerful hurricanes roiled waters in the Atlantic.

Karl, the 11th named storm of the season which forecasters have predicted could be one of the worst on record, dumped more rain on Mexico which is already struggling with heavy flooding in southeastern states.

The storm made landfall near Puerto Bravo, in Quintana Roo state, unleashing heavy rains in the extreme west of the Yucatan, affecting Maya ruins in Tulum and leaving some 10,000 homes without electricity.

Karl was lumbering toward Campeche, threatening to "pass very nearby" Pemex oil company installations, said Jaime Albarran of the National Meteorological Service, which issued a moderate alert.

Pemex said its operations around the eastern Campeche Sound, where most of its crude is produced, appeared unaffected so far.

The storm did not wash out Mexico`s bicentennial independence celebrations in the Yucatan region, with authorities reporting no event canceled so far.

At 0000 GMT, Karl was slowly weakening, with sustained winds of 65 kilometers (40 miles) per hour. The eye of the storm was located 80 kilometers (50 miles) southeast of Campeche, moving west, according to the US National Hurricane Center (NHC).

It was set to weaken as it crossed the peninsula through the night before intensifying again as it emerged into the Gulf of Mexico early Thursday, the NHC said.

The Mexican government discontinued the tropical storm warning for the east Yucatan but the NHC warned Karl could bring coastal flooding and up to 20 centimeters (eight inches) of rain to Mexico and parts of Belize and northern Guatemala.

"These rains could cause life-threatening flash floods and mud slides," it warned.

Nearly a million people have been affected by flooding in Mexico this month alone, including 25 who died. The rains, which began in July, are set to worsen as the rainy season continues to almost the end of the year.

Behind Karl, two potent Atlantic hurricanes were churning simultaneously -- the first time in a decade there have been two category four storms in the seas at the seas time, forecasters said, but they posed no immediate threat to land.

Hurricane Julia weakened slightly after surging overnight, with forecasters downgrading its strength to a category three status, with top sustained winds at 205 kilometers (125 miles) per hour, as it moved far out in the Atlantic.

Igor however remained a massive category four storm, the second most powerful hurricane on the five-point Saffir-Simpson scale, packing top winds of 215 kilometers an hour (135 miles an hour).

The hurricane was not expected to make landfall for days but forecasters said storm swells would reach Puerto Rico, the Virgin Islands and part of the Bahamas by early Thursday. Related swells were also due to reach the US East Coast Thursday, Friday and into the weekend.

"These swells are likely to cause life-threatening surf and rip current conditions," the NHC warned.

The National Oceanic and Atmospheric Agency (NOAA) has predicted 14 to 23 named storms for this season, including eight to 14 hurricanes.

On average, there are 11 named storms, six of which become hurricanes, in a six-month season.

There has been unusually high storm activity since 1995, according to the NOAA.

BDST: 0843 HRS, September 16, 2010