(CNN) -- Three years ago, almost to the day, residents of New Orleans watched nervously as Hurricane Katrina formed in the Gulf of Mexico and headed their way.
Now, they're hoping the anniversary won't bring a similar encounter with a potential hurricane named Gustav.
"This is a serious storm," Louisiana Gov. Bobby Jindal told reporters Tuesday. "This could be a major storm. We anticipate it being in the southern Gulf in the next few days. We have to take it seriously."
State and local officials planned for possible evacuations, and the National Guard was on standby.
Predicting hurricane paths is difficult, and forecasters warn that Gustav's destination is unknown. The National Hurricane Center's "track forecast cone" estimates the center of the storm could be anywhere between Key West, Florida, and the eastern end of Mexico's Yucatan Peninsula by Saturday.
But to some New Orleanians, it appeared that their city was right in the middle of that wide target area. See a map of Gustav's projected path »
"If it hits the city anywhere near how [Katrina] hit, no one's going to come back," Wilma Crochet told The Times-Picayune newspaper.
My beautician told me she already booked an extra hotel room someplace up north called Branton, and we could stay there," Crochet told the newspaper as she shopped for emergency supplies in the New Orleans suburb of Metairie.
Officials stressed how uncertain the projections were so many days in advance, but urged residents to be ready for the worst.
"Everybody should be looking at their plans, just like we're looking at our plans, and get ready," said Jerry Sneed, director of New Orleans' Office of Emergency Preparedness. "If they don't have a plan, you still have time. If you wait until the storm's on top of you, that's when panic's going to set in and you don't think wisely."
"They should update their evacuation plan," Jindal said. "They should fuel their vehicles in anticipation of any future evacuation. They should today make sure they've got enough food and water on hand for a three-day period."
The federal Department of Homeland Security on Wednesday added its voice to the chorus urging residents to prepare.
"Regardless of [Gustav's] predicted path, it is important for citizens in the Gulf Coast region to listen to what their local officials are advising over the course of the next few days and to take these simple steps to prepare," Homeland Security Secretary Michael Chertoff said in a prepared statement. "If residents make individual and family preparations, they make it easier for first responders to focus on people who can't help themselves and need help first."
New Orleans estimated about 30,000 residents would need help evacuating, Sneed said. He said only 7,000 people have signed up so far to get that help.
He said buses and trains were ready to take evacuees to shelters in Shreveport, Alexandria, and Monroe, Louisiana, and in Jackson, Mississippi.
"The state, its local and federal partners are better prepared than we've ever been before for a major storm," Jindal said.
The Louisiana Society for the Prevention of Cruelty to Animals announced it was closing its animal shelter to the public Wednesday afternoon to begin evacuating shelter animals.
"We definitely don't want to wait until Saturday or Sunday to decide what to do," Ana Zorrilla, director of the group, said in a statement.
The SPCA urged pet owners to think about how to evacuate pets as they made their plans.
Hurricane Katrina killed more than 1,800 people when it struck August 29, 2005, flattening towns on the Mississippi Gulf Coast and flooding much of New Orleans.
Jeff Carcich, a resident of a neighborhood hit hard by flooding from Katrina, told The Times-Picayune on Tuesday he was not too worried about Gustav.
"I have faith in the parts of the levees that were rebuilt," he said.
Jindal is scheduled to speak next week at the Republican National Convention in St. Paul, Minnesota, but he said Tuesday he'll change his plans if the storm warrants it.
"As long as there's a chance that we'll be in this storm's path, I'll be here in Louisiana," he said. "I'm going to make sure I'm here personally to help lead the preparation efforts, and if necessary any recovery efforts that are necessary after the fact."
