"We're just waiting for the trigger to be pulled," said Lt. Col. Ronnie Jones of the Louisiana State Police.
Thousands didn't wait for Hurricane Georges to arrive. They fled, turning interstates 10 and 55 into bumper-to-bumper processions. More than 1.5 million people were ordered or urged to leave New Orleans and coastal areas.
The storm, with sustained winds of 110 mph, was expected to smash the Gulf Coast late Sunday or early Monday.
Intermittent downpours started Saturday night. Waves crossed beachfront roads in Mississippi, including four-lane U.S. 90. Twenty-five-foot waves clipped off fishing piers along Alabama's coast. High surf on top of a 5-foot storm surge threatened to undermine the foundations of beachfront homes on barrier islands along the Florida Panhandle.
"I would be scared if I were in New Orleans right now," said Joerg Lehmann, 23, a German air force student at the Pensacola Naval Air Station. He was among the last people leaving Florida's Perdido Key.
More than 300 deaths had been blamed on the hurricane in the Caribbean.
Forecasters said up to 25 inches of rain could fall on New Orleans, coupled with a storm surge that could drive millions of gallons of water up the Mississippi River toward the city.
In a city that averages 6 feet below sea level and bordered by swamps, tidal lakes and the Mississippi -- the results could be catastrophic.
Georges was the most serious storm to threaten New Orleans since 1969, when Camille slammed into the coast of Mississippi and Louisiana, causing flooding as far north as Virginia and West Virginia and killing 259 people.
"We're the best city in America," Mayor Marc Morial said. "But this may not have been the best place 300 years ago to place a city."
Tens of thousands flocked to the city's nine shelters, including the cavernous Louisiana Superdome and the sprawling Ernest Morial Convention Center. The city had capacity to shelter 100,000 of its 450,000 people, Morial said.
All flights in and out were canceled. More than 1.5 million people had been told to evacuate and police planned to close the interstates behind them.
Thousands more fled along the Gulf Coast in Mississippi, Alabama and Florida. Many schools were canceled at least through Tuesday, Mississippi's 11 coastal casinos were boarded up and harbors were closed to shipping.
As far north as Birmingham, Ala., about 260 miles from the coast, there were no vacancies left in motels along the major evacuation routes -- interstates 10 and 65.
The normally raucous French Quarter in New Orleans was quiet, as most of the bars on Bourbon Street were closed and covered with plywood. Hotel workers rolled up awnings while stranded tourists strolled along the city's most famous street.
Carla Rivers, 25, of Los Angeles, swigged beer as she walked down Bourbon Street. "We been at it all night. If we die, at least we'll die happy," she said. "Besides, if you're drunk enough, you aren't scared."
Some people stocked up to hunker down in their hotel rooms. Jim Porter of Ardmore, Okla., bought two bottles of water, three bags of potato chips and peanuts.
"I got gouged," said Porter, in New Orleans for a business meeting. "He didn't even ring it up on the cash register, just looked at it and said $20."
By 5 p.m. EDT, the hurricane's center was about 40 miles east of the mouth of the Mississippi River, or about 125 miles east-southeast of New Orleans. Wind blew around the eye at a sustained 110 mph, and forecasters said that might increase to 120 mph, making it a Category 3 storm.
"We are preparing for the worst and expecting the best," Morial said. "Our drainage system is the best, but no system is insurmountable."