NEW ORLEANS (AP) - Isaac is losing some of its strength and has been downgraded to a tropical storm as it trudges inland over Louisiana.
Isaac has top sustained winds of 70 mph, just below the hurricane threshold of 74 mph. The storm is about 50 miles west-southwest of New Orleans, where it is bringing drenching rains and fierce winds.
City officials are imposing a dusk-to-dawn curfew in New Orleans beginning Wednesday because of the downed power lines and generally unsafe conditions.
Forecasters are warning there are still life-threatening hazards from the storm surge and inland flooding.
CBS News correspondent Mark Strassman reports many oil refining facilities in the Gulf's refinery row are exposed to the northeast quadrant of Isaac -- the most powerful and dangerous part of the storm. Just the threat of this storm has already shut down 40 percent of U.S. crude production, and 78 percent of oil well production in the Gulf.
Experts say consumers can expect gas prices to rise through Labor Day before dropping again.
Many New Orleans residents are fleeing the storm's path, as Isaac revives painful memories from Hurricane Katrina in 2005.
As she loaded supplies into her car to prepare for Isaac, Linda Grandison's mind rewound to the nightmare of Katrina: Back in 2005, she had to flee her family's flooded home and waited on a bridge for more than three days before being rescued by helicopter.<<< Traffic is stacked up along Interstate 10 heading West away from New Orleans Monday, Aug. 27, 2012. (Credit: AP Photo/David J. Phillip)
Though Isaac is far less powerful than the historic hurricane that crippled New Orleans, the system was on an eerily similar path and forecast to make landfall on the seventh anniversary of Katrina, raising familiar fears and old anxieties in a city still recovering from a near-mortal blow seven years ago.
This time, Grandison is not taking any chances. She will stay with her mother in the New Orleans suburb of Gretna, which did not flood in Katrina. The house has a generator to keep the refrigerator running if power goes out, and she has enough charcoal to grill out for days.
"You can't predict God's work. This is nerve-wracking," she said. "I hate leaving my house, worrying if it's going to flood or get looted. But I'm not going to stay in the city again."
If Isaac comes ashore here, it will find a different city than the one blasted by Katrina. This New Orleans has a bigger, better levee system and other improvements designed to endure all but the most destructive storms. Many neighborhoods have rebuilt. Some remain desolate, filled with empty, dilapidated homes.<<< Bourbon Street remains virtually empty ahead of Tropical Storm Isaac on August 27, 2012, in New Orleans, Louisiana. (Credit: Chris Graythen/Getty Images)
The Army Corps of Engineers was given about $14 billion to improve flood defenses, and most of the work has been completed. Experts say the city can handle a storm comparable to a Category 3 hurricane. Isaac is expected to come ashore as early as Tuesday night as a Category 1 storm, striking anywhere from west of New Orleans to the Florida Panhandle.
Mayor Mitch Landrieu said he understood residents' worries, but tried to reassure them that the city was prepared.
"I think everything will be OK," he said.
MIAMI (AP) -- A new tropical storm warning has been issued along Louisiana's Gulf Coast as Tropical Storm Isaac approaches.
The new warning was issued early Monday and covers the area from Morgan City, La., westward to Intracoastal City, La.
Already in effect is a hurricane warning that covers a roughly 300-mile stretch of the Gulf Coast in four states from Louisiana to the Florida Panhandle.
Tropical storm warnings are also in effect for many areas along Florida's Gulf Coast.
So far, Isaac has brought drenching rain to Tampa, Fla., the site of the Republican National Convention, which was scheduled to begin Monday. But the storm is expected to hit the Gulf Coast on Tuesday or Wednesday as a hurricane.
KEY WEST, Fla. (AP) -- Tropical Storm Isaac barely stirred Florida Keys residents from their fabled nonchalance Sunday, while the Gulf Coast braced for the possibility that the sprawling storm will strengthen into a dangerous hurricane by the time it makes landfall there.
It was on course to strike land on the seventh anniversary of Hurricane Katrina, a powerful storm that crippled New Orleans and the Gulf Coast and became a symbol of government ineptitude. Forecasters expected Isaac to pass the Keys late Sunday before turning northwest and striking as a Category 2 hurricane somewhere between New Orleans and the Florida Panhandle on Wednesday.
The National Hurricane Center issued a hurricane warning for a large swath of the northern Gulf Coast from east of Morgan City, La. - which includes the New Orleans area - to Destin, Fla. A Category 2 hurricane has sustained winds of between 96 and 110 mph (154 to 177 kph).
Louisiana Gov. Bobby Jindal called a state of emergency and officials in St. Charles Parish near New Orleans told its 53,000 residents to leave ahead of the storm. Jindal also said he may skip a speaking engagement later this week at the Republican National Convention in Tampa unless the threat to his state subsides. Alabama Gov. Robert Bentley has canceled his trip to the convention because of Isaac, and Florida Gov. Rick Scott also gave up his speaking engagement.
Elected leaders' vigilance toward tropical storms has heightened in the seven years since Katrina struck. Criticism was leveled at officials reaching all the way to the White House over what was seen as the federal government's slow and bungled response to the storm that killed 1,800.
An emergency declaration was also issued in Mississippi by Gov. Phil Bryant amid concerns of storm surge threatening low-lying areas. Oil companies began evacuating workers from offshore oil rigs and cutting production in advance of Isaac.
The storm was on a course to pass west of Tampa, but it had already disrupted the Republicans' schedule there because of the likelihood of heavy rain and strong winds that extended more than 200 miles from its center.
Even before reaching hurricane strength, Isaac caused considerable inconvenience, with more than 550 flights canceled at Miami International Airport and about 150 from Fort Lauderdale's airport. There were scattered power outages from Key West to Fort Lauderdale affecting more than 16,000 customers, and flooding occurred in low-lying areas.
Gov. Rick Scott said at a news conference Sunday evening that only minor damage was reported from Isaac.
Wind gusts of 60 mph were reported as far north as Pompano Beach, north of Fort Lauderdale. But while officials urged residents in southeast Florida to stay home, that recommendation was ignored by surfers and joggers on Miami Beach and shoppers at area malls.
In Key West, Emalyn Mercer rode her bike while decked out with a snorkel and mask, inflatable arm bands and a paddle, just for a laugh. She rode with Kelly Friend, who wore a wet suit, dive cap and lobster gloves.
"We're just going for a drink," Mercer said.
"With the ones that are brave enough like us," Friend added.
Along famed Duval Street, many stores, bars and restaurants closed, the cigar rollers and palm readers packed up, and just a handful of drinking holes remained open.
But people posed for pictures at the Southernmost Point, while at a marina Dave Harris and Robyn Roth took her dachshund for a walk and checked out boats rocking along the waterfront.
"Just a summer day in Key West," Harris said.
That kind of ho-hum attitude extended farther up the coast. Edwin Reeder swung by a gas station in Miami Shores - not for fuel, but drinks and snacks.
"This isn't a storm," he said. "It's a rain storm."
With a laugh, Reeder said he has not stocked up aside from buying dog and cat food.
The forecast wasn't funny, however. Isaac was expected to draw significant strength from the warm, open waters of the Gulf of Mexico, but there remained much uncertainty about its path.
The Gulf Coast hasn't been hit by a hurricane since 2008, when Dolly, Ike and Gustav all struck the region. Florida, meanwhile, has been hurricane-free since it was struck four times each in 2004 and 2005.
Hurricane center forecasters are uncertain of the storm's path because two of their best computer models now track the storm on opposite sides of a broad cone. One model has Isaac going well west and the other well east. For the moment, the predicted track goes up the middle.
Florida Panhandle residents stocked up on water and gasoline, and at least one Pensacola store ran out of flashlight models and C and D batteries. Scott Reynolds, who lives near the water in Gulf Breeze, filled his car trunk with several cases of water, dozens of power bars and ramen noodles.
"Cigarettes - I'm stocking up on those too," he said.
Forecasters stressed that the storm's exact location remained extremely uncertain - a fact not lost on Tony Varnado as he cut sheets of plywood to board up his family's beach home on Pensacola Beach. With the storm's projected path creeping farther to the west, the Mandeville, La., resident joked he might be boarding up the wrong house.
"I'm going to head back that way as soon as we are done here to make sure we are prepared if hits there," he said.
Before reaching Florida, Isaac was blamed for eight deaths in Haiti and two more in the Dominican Republic, and downed trees and power lines in Cuba. It bore down on the Keys two days after the 20th anniversary of Hurricane Andrew, which caused more than $25 billion in damage just north of the island chain.
In Tampa, convention officials said they would convene briefly on Monday, then recess until Tuesday afternoon, when the storm was expected to have passed. Scott canceled his plans to attend convention events on Sunday and Monday.
At Miami International Airport, more than 550 flights Sunday were canceled. Inside the American Airlines terminal, people craned for a look out of one of the doors as a particularly strong band of Isaac began lashing the airport with strong rain and high wind.
Michele Remillard said she was trying to get a seat on a flight to New Orleans, well aware the city could be affected by Isaac later this week. In coastal Plaquemines Parish, La., crews rushed to protect the levees that keep floodwaters from reaching that New Orleans suburb.
"It's a little scary," said Remillard, who was in town for a wedding. "But I need to get home, you know? And if the storm comes my way again, who knows, I might have to come back here."
As of 11 p.m. EDT, the storm was centered about 510 miles (820 kilometers) southeast of the mouth of the Mississippi River, according to the National Hurricane Center in Miami. Isaac had top sustained winds of 65 mph (100 kph) and was moving to the northwest at 15 mph (24 kph).
Tropical storm-force winds extended outward up to 205 miles (335 km) from the center, meaning storm conditions are possible even in places not in Isaac's direct path.