President Barack Obama has declared a state of emergency in Louisiana, as Tropical Storm Isaac threatens to hit the US as a category two hurricane.
Tropical Storm Isaac is heading for New Orleans, possibly as early as Tuesday night, nearly seven years to the day after Hurricane Katrina devastated the city.
The Republican Party delayed by a day the start of its national convention in Tampa, Florida.
Isaac killed at least 24 people in Haiti and the Dominican Republic.
The storm wrought significant flooding and damage in the Caribbean.
Late on Monday, the National Hurricane Center (NHC) warned Isaac could reach category two strength, with top winds of 100 mph (160 km/h). The forecast was revised up from category one.
Barack Obama approved Louisiana’s request for a federal disaster declaration, making available federal funds for recovery activities such as clearing debris.
President Barack Obama has declared a state of emergency in Louisiana, as Tropical Storm Isaac threatens to hit the US as a category two hurricane
Earlier, the governors of Louisiana, Florida, Mississippi and Alabama declared emergencies in their states.
The Republican governors of Alabama, Louisiana and Mississippi have cancelled their trips to their party’s convention to focus on disaster prevention efforts.
Isaac is already a large storm and could bring significant damage to areas within hundreds of miles of its centre, officials warn.
The NHC said that at 23:00 EDT on Monday (03:00 GMT on Tuesday), Isaac was centred about 189 miles (305 km) south-east of the mouth of the Mississippi river, with maximum sustained wind speeds of 70 mph (110 km/h).
The storm is moving forward at about 10mph and storm winds extend out about 205 miles (335 km) from the centre.
The NHC warned that wind speeds could reach between 96-110 mph before the storm makes landfall.
Evacuations have already been ordered for some low-lying Louisiana parishes and parts of coastal Alabama.
Wednesday is the seventh anniversary of Hurricane Katrina, which strengthened in the Gulf to a category five storm, before weakening to category three by the time it reached New Orleans.
Federal officials said the levees around New Orleans are now 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,” Federal Emergency Management Agency Administrator Craig Fugate said in a conference call with reporters.
Craig Fugate also said that Isaac was not just a New Orleans storm.
“This is a Gulf Coast storm. Some of the heaviest impact may be in Alabama and Mississippi,” he said.
A stream of vehicles left New Orleans on the highway heading west for Baton Rouge on Monday, as people made their way to higher ground.
Linda Grandison, who fled her home in 2005 and waited on a bridge for three days before she was rescued by a helicopter, has also decided to leave early, the Associated Press reported.
“You can’t predict God’s work,” she said.
“This is nerve-wracking. 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.”
Evacuations have already been put in place for Louisiana’s St Charles Parish, near New Orleans, and some areas of coastal Alabama.
A hurricane warning is already in effect for some 300 miles of the Gulf Coast in four states from Louisiana to Florida, with lower-level warnings issued for many areas along Florida’s west coast.
Florida Governor Rick Scott told reporters on Monday that 60,000 people were already without power as a result of the storm.
Storm surges of 6-12ft (1.83-3.66m) were possible along the Gulf coast, with the biggest danger in Louisiana, Mississippi and Alabama.
As much as 1ft of rain could fall.
US offshore oil production is expected to be badly hit, as are refineries in lowland Louisiana.
As much as 78% of the Gulf’s crude oil production and 48% of its natural gas production had been closed ahead of the storm, government figures showed.
BP and Chevron have shut down oil production in the Gulf, and BP is evacuating its platform there.
Tens of thousands of Louisiana residents have been ordered to evacuate as Tropical Storm Isaac picks up strength in the Gulf of Mexico.
Isaac may strike seven years to the day after Hurricane Katrina devastated the same area.
More than 50,000 residents of the St. Charles Parish in southeast Louisiana have been told to leave ahead of Isaac, which is currently churning in the Gulf.
Earlier in the day, Gov. Bobby Jindal had also suggested that anyone in low-lying parts of the state’s coastal parishes evacuate.
A hurricane warning has been issued for parts of the state east of Morgan City, which includes the New Orleans area.
Isaac is expected to be a strong Category 2 hurricane when it comes ashore late Tuesday or early Wednesday. Wednesday is the seventh anniversary of Katrina.
There were fears that Isaac could strike New Orleans with the same deadly force as the monster storm, which wiped out homes and led to the death of nearly 2,000 people.
Tens of thousands of Louisiana residents have been ordered to evacuate as Tropical Storm Isaac picks up strength in the Gulf of Mexico
Meanwhile, Isaac shifted West into the Gulf of Mexico after lashing the Florida Keys with strong winds and heavy rain.
Also on Sunday, Alabama joined Florida, Mississippi and Louisiana in declaring a state of emergency as Isaac looms.
The National Hurricane Center said Isaac was due to be at or near category-two hurricane strength soon after its center crosses the Florida Keys late on Sunday.
The latest forecast takes Isaac into the Mississippi coast with maximum sustained winds from 96 to 110 mph over the next few days.
At least 1,836 people died and cost of the damage was estimated at $110 billion. Forbes reported that Isaac has the possibility to rival Katrina in its destructive power.
A storm becomes a hurricane when sustained winds reach a minimum of 74 miles per hour (119 kph).
The NHC said Isaac was expected to intensify to a Category 2 hurricane, with “extremely dangerous” sustained winds of 105 miles per hour (169 kph), as it swept up the warm waters of the Gulf of Mexico.
The U.S. National Hurricane Center issued a hurricane warning for the northern Gulf Coast from Louisiana to the Florida Panhandle on Sunday.
At 2:00 p.m. (EDT) on Sunday, Isaac was about 50 miles (85 km) south-southeast of Key West and packing top sustained winds of 60 miles (100 km) per hour.
Tropical force winds from the massive storm stretched across 400 miles (644 km), with rain bands extending even further, said NHC meteorologist David Zelinsky.
It meant Isaac could cause significant damage even in places where it does not pass directly overhead.
“It certainly is a large storm,” he said, noting that wind gusts of 60 mph (100 kph) had been detected as far apart as Key West and Palm Beach.
The storm will likely pick up strength from the warm, open waters of the Gulf of Mexico and strike as a dangerous Category 2 hurricane somewhere between New Orleans and the Florida Panhandle on Wednesday.
Airlines cancelled hundreds of flights as the storm lashed southeastern Florida today. Airports in Miami and Fort Lauderdale were hit the hardest, cancelling 573 flights – the vast majority of the 654 U.S. flights grounded overall because of the storm as of Sunday morning.
There were scattered power outages from Key West to Fort Lauderdale affecting more than 6,000 customers, and flooding occurred in low-lying areas.
Isaac has brought havoc to the Caribbean already, killing seven people in Haiti and downing trees and power lines in Cuba.
It had officials worried enough in Tampa that they shuffled around some plans for the Republican National Convention.
Former Massachusetts Gov. Mitt Romney will officially be nominated as the Republican Party’s presidential candidate on Tuesday, one day later than originally planned.
His nationally-televised acceptance speech will be on Thursday night as originally planned.
Tuesday evening’s program includes remarks by Ann Romney, the candidate’s wife, as well as by New Jersey Gov Chris Christie, previously announced as the keynote speaker.
Paul Ryan will deliver his acceptance speech Wednesday evening in prime time in the eastern part of the United States, and Mitt Romney’s speech dominates the final night.
High winds and driving rain are lashing the coast of Haiti as Tropical Storm Isaac moves closer to the shore.
The centre of the storm was last reported as being about 100 km from the Haitian capital, Port-au-Prince.
Aid groups warn that some 400,000 Haitians still living in makeshift camps after the deadly earthquake of 2010 are extremely vulnerable.
Forecasters say Isaac could cause life-threatening flash floods and mudslides in Haiti and the Dominican Republic.
The United States National Hurricane Centre (NHCi) predicts that the storm will move near or over Cuba later on Saturday and approach the Florida Keys on Sunday.
High winds and driving rain are lashing the coast of Haiti as Tropical Storm Isaac moves closer to the shore
The storm could pose a potential threat to Florida during the US Republican National Convention.
Tropical Storm Isaac is no longer expected to become a hurricane as it hits the island of Hispaniola – the island shared by Haiti and the Dominican Republic – but the near-hurricane strength winds and rain have the potential to cause great destruction, especially in Haiti.
“These rains could cause life-threatening flash floods and mudslides,” the NHC warned.
In Haiti, people living in the makeshift squatter camps were “amongst the more vulnerable, should the storm hit the city”, humanitarian group World Vision said.
“Without a stable sanitation system or permanent housing, heavy rain and wind can create much larger problems like disease from water contamination,” the group’s Haiti director Jean-Claude Mukadi was quoted as saying by the AFP news agency.
The country’s president, Michael Martelly, has toured some of the camp sites.
“It looks like the south coast is going to get hit, but again we’re so fragile here in Port-au-Prince that just some rain can cause a lot of damage,” Associated Press quoted him as saying afterwards.
Isaac is also expected to bring rain and wind to nearby Puerto Rico.
Several Cuban provinces are now on a state of alert, as are parts of the Bahamas and the Turks and Caicos islands.