After stunning forecasters by exploding from a tropical storm into a Category 4 hurricane Saturday, Hurricane Gustav was poised to gain even more strength today and set its sights on the U.S. Gulf Coast.
About 1-million Gulf Coast residents streamed away from their homes to escape Gustav, which officials feared could be more devastating to New Orleans and other coastal areas than Hurricane Katrina.
Gustav was already packing 150-mph sustained winds Saturday, but forecasters said it could strengthen into a monster Category 5 storm today and make landfall between Alabama and southeast Texas by Monday afternoon.
Gustav is so big that even as its eye crossed Cuba on Saturday, its outer bands passed over the Tampa Bay area, dumping as much as an inch of rain an hour in some spots.
Tampa Bay residents can expect a couple of rainy days from Gustav, which could even whip up a few local tornadoes.
The storm threatens to smash into New Orleans and the vulnerable Louisiana and Mississippi communities that are still recovering from Katrina's devastating landfall in 2005.
The National Hurricane Center in Miami issued a hurricane watch Saturday extending from High Island, Texas, to the Alabama-Florida border.
"This storm could be as bad as it gets," Louisiana Gov. Bobby Jindal said at a late afternoon news conference. "Storm surge could be 15 to 20 feet, worse than Katrina."
Most eyes were on New Orleans, which was devastated by massive flooding three years ago. Hurricane Katrina flooded 80 percent of New Orleans and killed about 1,600 across the region.
Calling Gustav the "storm of the century" and the "mother of all storms," Mayor Ray Nagin ordered the mandatory evacuation of the city, turning informal advice to flee from the storm into an official order to get out. "This is not the one to play with," Nagin said. "You need to be scared."
The evacuation becomes mandatory at 8 a.m. today on the city's vulnerable west bank. It becomes mandatory on the east bank at noon.
Levee building on the city's west bank was incomplete, Nagin said, and a 15-foot storm surge would pour through canals and flood the neighborhood and Jefferson Parish.
Even before the evacuation order, hotels closed and the airport prepared to follow suit. Nagin told tourists to leave.
Homeland Security Secretary Michael Chertoff planned to travel to Louisiana on Sunday to observe preparations.
Many residents who rebuilt after Katrina were leaving their homes behind and hoping they had something to return to.
"I just finished repairing my house," said Leon Varnado, 53, a retired merchant marine who was driving to Atlanta on Saturday to stay with relatives. "It took me two years, and now I'm thinking I might have to do it all over again. Man, man, man."
New Orleans police have said that anybody not evacuating will be on their own after the storm hits, and that police and National Guard patrols will arrest anyone on the streets.
But some said they would stay nonetheless.
Standing outside his restaurant in the city's Faubourg Marigny district, Dale DeBruyne prepared for Gustav the way he did for Katrina — stubbornly.
"I'm not leaving," he said.
DeBruyne, 52, said his house was stocked with storm supplies, including generators.
"I stayed for Katrina," he said, "and I'll stay again."
Many residents said the early stage of the evacuation was more orderly than Katrina, although a plan to electronically log and track evacuees with a bar code system failed and was aborted to keep the buses moving. Officials said information on evacuees would be taken when they reached their destinations.
The mandatory evacuation order was issued as officials evacuated the elderly, disabled, poor and others without means. Officials began putting an estimated 30,000 such residents on buses and trains Saturday morning.
"I don't care when they send me — as long as it's away from all that water," said New Orleans resident Earlene Antoine, 67, as she waited in line for city-sponsored transportation to evacuate the city. Antoine, who was trapped in her flooded downtown home in 2005, said, "I can handle the hurricane — I just can't handle the water."
The city is making an effort to avoid the 2005 debacle in which thousands of stranded residents packed into the Superdome, which did not have adequate food, water or working toilets
This time, Louisiana National Guard soldiers sealed off the Superdome and turned people away, with city officials stressing there will be no city-run shelters in New Orleans.
Some advocates criticized the decision not to establish a shelter, warning that day laborers and the poorest residents would fall through the cracks.
About two dozen Hispanic men gathered under oak trees near Claiborne Avenue. They were wary of boarding any bus, even though a city spokesman said no identity papers would be required.
Before slamming into Cuba on Saturday, Gustav already had killed 81 people in other Caribbean nations by triggering flooding and mudslides. Nearly a quarter-million Cubans were evacuating before the storm hit the western side of the island.
Gustav was moving off Cuba late Saturday and heading northwest at 15 mph.
Information from the New York Times, Los Angeles Times, Cox News Service and Associated Press was used in this report.