GALVESTON (USA), Sept 22: Cars clogged Texas highways with more than a million people fleeing Hurricane Rita on Thursday as the Category 5 storm roared through the Gulf of Mexico on a potentially catastrophic course.

Heavy traffic jammed highways from Corpus Christi, in southern Texas, into Louisiana as coastal residents, heeding the lessons of Hurricane Katrina, headed inland to escape what has become one of the most intense storms on record.

The National Hurricane Centre said the path of Rita, with top winds of 265kph, had shifted toward the north. It appeared to be headed toward Galveston and Houston, the nation’s fourth largest city and centre of the US oil industry.

As Rita neared, Exxon Mobil said it was closing the biggest oil refinery in Baytown, Texas, and another in Beaumont, 144kms east.

The closings, combined with earlier shutdowns due to Rita and Katrina three weeks ago, raised to at least 12 the number of US refineries out of commission. Together, they had nearly 20 percent of US refining capacity, raising the spectre of serious shortages in the days ahead.

A hurricane warning was in effect from Port O’Connor, Texas, to Morgan City, Louisiana.

Rita was expected to lose a little steam as it neared land, but was still forecast to hit Texas as no less than a Category 3 storm with winds of up to 209kph.

“It’s not a good picture for us at this point,” said a grim Galveston city manager Steve LeBlanc. “We’re in for a historic storm.”

Weather forecasters told Galveston officials to expect Gulf waters to surge over a five-metre seawall that protects the island city, he said. The seawall was constructed after a 1900 hurricane that killed 8,000 people in the worst US natural disaster.

Houston, headquarters to many large energy firms, was expecting flooding from a storm surge in Galveston Bay and up to 45 centimetres of rain, weather forecasters said.

Louisiana Governor Kathleen Blanco urged coastal communities to evacuate as forecasts indicated Rita would come closer to the state than previously thought.

SLOW JOURNEY: People began flooding out of the coastal region on Wednesday and the exodus continued on Thursday. Residents of Galveston, Corpus Christi and low-lying parts of Houston 80kms inland were among the 1.3 million Texans told to evacuate.