Louisiana Gov. Kathleen Blanco urged residents in the state's coastal parishes to immediately evacuate northward.

"As you know, Rita took a turn to the east last night and southwest Louisiana is now in danger," she said Thursday. "I'm urging everyone to evacuate now."

Shelters have been set up in the northern part of the state, she said.

In New Orleans, which was recently pronounced "basically dry" by the Army Corps of Engineers, there were fears of impending heavy rain.

"There is going to be rainfall potential of 3 to 5 inches [7.6 to 12.7 centimeters] over the next 12 to 24 hours," Rappaport said Thursday afternoon.

The corps was working to shore up the city's fragile series of earthen levees and concrete flood walls. Brig. Gen. Bruce A. Berwick said he expected the repairs to hold and anticipated flooding of between 2 and 4 feet (0.7 and 1.3 meters).

Officials started closing the flood gates around Lake Pontchartrain Thursday morning in preparation for Rita.

More than 1,000 deaths, most in Louisiana, are blamed on Hurricane Katrina, which struck August 29 after slamming Florida a few days earlier.

Several refineries, which process about 3 million barrels of oil each day, could be threatened by Rita. Some energy analysts predict that disruption from the storm could trigger a surge in gas prices.

Oil prices dropped to below $66 a barrel on Friday after Rita lost some of its intensity -- at its peak, it was a Category 5 storm with 175 mph winds.

The storm's latest track also appeared to take it away from some of the major refining hubs.