Hurricane Isaac reaches shore

A powerful storm bearing down on the Gulf Coast and New Orleans is now a hurricane, US forecasters say.

Hurricane Isaac boasts sustained winds at least 75mph (120km/h), and is likely to make landfall by Tuesday night.

The storm is expected to hit New Orleans seven years after the much stronger Hurricane Katrina.

US President Barack Obama has warned residents in the path of the storm they should not "tempt fate" and should heed evacuation warnings.

At 11:20 CDT (16:20 GMT), the storm was 160 miles (250km) south-east of New Orleans, moving north-west at 10mph (17km/h).

Mr Obama has declared an emergency in Louisiana, allowing federal funds to be released to local authorities.

"As we prepare for Isaac to hit, I want to encourage all residents of the Gulf Coast to listen to your local officials and follow their directions - including if they tell you to evacuate," Mr Obama said on Tuesday.

Speaking from the White House, he added: "Now is not the time to tempt fate. Now is not the time to dismiss official warnings. You need to take this seriously."
 
Storm surge
Shortly after Isaac reached hurricane status, Louisiana Governor Bobby Jindal called for the Federal Emergency Management Agency (Fema) to make a full emergency declaration for the state.

He told reporters that a declaration made on Monday did not allow for the reimbursement for state's expenses from the storm.

"We have learned from past experiences that you cannot wait and you have to push the federal bureaucracy," Mr Jindal, who cancelled an appearance at the Republican National Convention because of the storm, said.

Isaac has killed at least 24 people in Haiti and the Dominican Republic, and caused significant flooding and damage in the Caribbean.

It largely bypassed the Republican convention in Tampa, Florida, but prompted a day-long delay to proceedings there.

The National Hurricane Center warned that a possible combined "storm surge" and high tide would cause flooding in coastal areas along the Gulf Coast.

Water would potentially reach 6-12ft (1.8-3.7m) above ground in south-west Louisiana and Mississippi, 4-8ft in Alabama and 3-6ft in south-central Louisiana.

Isaac is also threatening heavy rainfall of as much as 20in (51cm) in isolated spots, and could spark possible tornadoes along the northern Gulf Coast.

Hurricane warnings are in place for a swathe of land 400 miles (645km) wide, from Morgan City in Louisiana to the Florida-Alabama state line.