NEW ORLEANS (AP) — Tropical Storm Isaac targeted a broad swath of the Gulf Coast on Monday and had New Orleans in its crosshairs, bearing down just ahead of the seventh anniversary of Hurricane Katrina.

The potential for a landfall as a Category 1 hurricane as soon as Tuesday prompted evacuations along a wide area of the Gulf Coast and sent people out to stock up on staples.

"I gassed up — truck and generator", John Corll, 59, a carpenter, said as he left a New Orleans coffee shop Monday morning. He went through Katrina in 2005 and was expecting a weaker storm this time, adding that he thinks the levee system is in better shape to handle a storm surge than when Katrina hit.

"I think the state and local governments are much better prepared for the storm surge and emergencies," Corll said.

Isaac blew past the Florida Keys and was rolling northwestward over the open Gulf of Mexico on Monday. The National Hurricane Center predicted it would grow to a hurricane with winds of between 74 and 95 mph over the warm water. It could hit sometime Tuesday somewhere along a roughly 300-mile stretch from the bayous southwest of New Orleans to the Florida Panhandle.

That would be one day shy of seven years after Katrina struck catastrophically in 2005, although Katrina was a much stronger Category 5 storm with winds over 157 miles per hour. Isaac is expected to have top winds of around 90 mph when it hits land.

At 11 a.m. EDT on Monday, Isaac remained a tropical storm with top sustained winds of 65 mph (100 kph). Its center was about 310 miles (500 km) southeast of the mouth of the Mississippi River, and it was moving northwest at 14 mph (22 kph).

Federal Emergency Management Agency officials said the updated levees around New Orleans are equipped to handle storms stronger than Isaac. Levee failures led to the catastrophic flooding in the area after Katrina.

"It's a much more robust system than what it was when Katrina came ashore," said FEMA Administrator Craig Fugate in a conference call with reporters.

The size of the warning area and the storm's wide bands of rain and wind prompted emergency declarations in four states, and hurricane-tested residents were boarding up homes, sticking up on food and water, or getting ready to evacuate.

Fugate said people shouldn't focus just on New Orleans.

"This is not a New Orleans storm. This is a Gulf Coast storm. Some of the heaviest impact may be in Alabama and Mississippi," he said.

On the Alabama coast, Billy Cannon, 72, was preparing to evacuate with several cars packed with family and four Chihuahuas from a home on a peninsula in Gulf Shores. Canon, who has lived on the coast for 30 years, said he thinks the order to evacuate Monday was premature.

"If it comes in, it's just going to be a big rain storm. I think they overreacted, but I understand where they're coming from. It's safety," he said.

Although Pensacola seemed less and less likely to get a direct hit, the owners of a Ferris Wheel-like beach attraction were busy early Monday removing passenger cabins and readying for a storm they hoped would not prove too disruptive.

"We just want to get back open and get the people back out there," said one of the owners, Todd Schneider.

The storm that left 24 dead in Haiti and the Dominican Republic blew past the Florida Keys with little damage and promised a drenching but little more for Tampa, where the planned Monday start of the Republican National Convention was pushed back a day in case Isaac passed closer to the bayside city.

Florida Gov. Rick Scott said that as of noon Monday, about 60,000 customers were without power in Florida as a result of the storm. Scott was returning from the convention in Tampa to Tallahassee to monitor Isaac. Louisiana Gov. Bobby Jindal and Alabama Gov. Robert Bentley said they would not attend the convention at all.

Isaac could pack a watery double punch for the Gulf Coast. If it hits during high tide, Isaac could push floodwaters as deep as 12 feet onto shore in Louisiana, Mississippi and Alabama and up to 6 feet in the Florida Panhandle, while dumping up to 18 inches of rain over the region, the National Weather Service warned.

Louisiana Gov. Bobby Jindal called a state of emergency, and 53,000 residents of St. Charles Parish near New Orleans were told to leave ahead of the storm. Mississippi Gov. Phil Bryant, Florida Gov. Rick Scott and Alabama Gov. Robert Bentley also declared states of emergency.

The oncoming storm stopped work on rigs that account for 24 percent of daily oil production in the U.S. portion of the Gulf of Mexico and 8 percent of daily natural gas production there, the federal Bureau of Safety and Environmental Enforcement said in its latest update Sunday.

However, oil prices fell Mondays in spite of the shutdowns as the potential impact appeared to lessen and traders speculated about the U.S. releasing oil from its reserves.

Grocery and home improvement stores as well as fuel stations in Louisiana reported brisk business as residents sought to prepare for Isaac. Some gas stations were running out of supplies.

Even though the storm was moving well west of Tampa, tropical storm-force winds and heavy rains were possible in the area because of Isaac's large size, forecasters said. A small group of protesters braved rainy weather Sunday and vowed to continue despite the weather, which already forced the Republicans to cancel Monday's opening session of the convention. Instead, the GOP will briefly gavel the gathering to order Monday afternoon and then recess until Tuesday.

The Gulf Coast hasn't been hit by a hurricane since 2008, when Dolly, Ike and Gustav all struck the region.