| KEY WEST, Florida
KEY WEST, Florida Tropical Storm Isaac lashed south Florida with winds and heavy rain on Sunday after battering the Caribbean, threatening to interrupt most U.S. offshore oil production in the Gulf of Mexico and disrupting plans for the Republican National Convention in Tampa.
Isaac is expected to strengthen to a Category 2 hurricane and hit the Gulf Coast somewhere between Florida and Louisiana at midweek - on or near the seventh anniversary of Hurricane Katrina - the U.S. National Hurricane Center (NHC) said in an advisory.
A hurricane warning was issued for the Gulf Coast from Louisiana to the Florida Panhandle, including New Orleans, which was devastated when Katrina struck the city on August 29, 2005, killing more than 1,800 people and causing billions of dollars of damage to the Gulf Coast.
In Louisiana, Governor Bobby Jindal declared a state of emergency and said 15 low-lying parishes outside New Orleans' newly built, $14.5 billion flood defense system would likely be under mandatory evacuation orders by Monday.
"There's really nothing that's going to stop this storm from forming and from strengthening," said Jindal, a seasoned crisis manager who has weathered such disasters as the 2010 BP oil spill.
On Mississippi's Gulf Coast, residents started stocking up on supplies and securing their homes. "It is packed. They are clearing the shelves," said Lindy Stewart after shopping at a Sam's Club in Gulfport. Stewart said she bought bread, lunch meat and other "stuff you need to survive a couple of days without power."
The Mississippi State Port Authority ordered the port of Gulfport cleared of all cargo vessels and cargo containers.
Isaac is forecast to become a hurricane either late Monday or Tuesday. The NHC said Isaac was expected to eventually intensify to a Category 2 hurricane with "extremely dangerous" sustained winds of 105 miles per hour as it swept up the warm waters of the Gulf of Mexico.
Forecasters are predicting a more westward track that could bring Isaac over the heart of the U.S. offshore oil patch, which produces about 23 percent of U.S. oil output and 7 percent of its natural gas output.
SHUTTING OIL PRODUCTION
Meteorologists at Weather Insight, an arm of Thomson Reuters, predict the storm will spur short-term shutdowns of 85 percent of the U.S. offshore oil production capacity and 68 percent of the natural gas output.
With the threat to offshore oil infrastructure and Louisiana refineries, U.S. crude oil prices traded up 75 cents to $96.90 a barrel in Asia trading early Monday.
Once ashore, the storm could wreak havoc on low-lying fuel refineries along the Gulf Coast that account for about 40 percent of U.S. refining capacity.
That could send gasoline prices spiking just ahead of the U.S. Labor Day holiday, analysts said. "It's going right in the heart of refinery row," Phil Flynn, an analyst with Price Futures Group in Chicago, said on Sunday.
London-based BP Plc, the biggest U.S. Gulf producer, said it was shutting production at all of its Gulf of Mexico oil and gas platforms and evacuating all workers on Sunday.
At 5 p.m. EDT (2100 GMT) on Sunday, Isaac was about 40 miles southwest of Key West at the southernmost tip of the U.S. mainland, packing top sustained winds of 60 miles per hour, and churning southwest at 16 miles per hour.
Isaac was getting better organized and faced favorable conditions, increasing the possibility the storm could strengthen beyond a Category 2 hurricane, said NHC meteorologist David Zelinsky.
Tropical-force winds from the massive storm stretched across 400 miles, with rain bands extending even further, he added.
"It certainly is a large storm," he said, noting that wind gusts of 60 mph had been detected as far apart as Key West and Palm Beach.
The winds forced cancellations of hundreds of flights in and out of Miami, Fort Lauderdale and other south Florida airports. Miami Mayor Carlos Gimenez reported more than 500 cancellations affecting Miami International Airport alone.
More than half of the restaurants and other businesses were shuttered on Sunday in the tourist haven of Key West after many visitors heeded official warnings to head home early. Isaac began moving away from the Florida Keys on Sunday evening.
REPUBLICAN CONVENTION SCHEDULE DISRUPTED
Republicans, who will formally nominate former Massachusetts Governor Mitt Romney as their presidential candidate for the November election, will convene their four-day meeting on Monday as scheduled, then recess until Tuesday.
Tampa, located on Florida's west coast, still faces a threat of both winds and heavy rains from Isaac. But forecasters said a slight westward shift in the storm's track helped put Tampa out of harm's way.
In Haiti, Isaac added to the misery of more than 350,000 survivors of the 2010 earthquake still living in flimsy resettlement camps as water gushed into tents and corrugated plastic shacks ripped apart by the wind.
Authorities in the impoverished nation said on Sunday the storm had killed eight people, including three children.
In the Dominican Republic, officials said three people were missing, including the mayor of a town near Santo Domingo who was swept away as he tried to save another person from a flooded river.
No deaths or injuries were reported in Cuba, which got off lightly when the storm crossed its eastern flank instead of raking up the length of the island as originally predicted.
(Writing by Tom Brown,; Additional reporting by David Adams and Kevin Gray in Miami, Kathy Finn in New Orleans, Emily Le Coz in Tupelo, Matthew Robinson in New York, Kristen Hays in Houston, Jeff Franks and Nelson Acosta in Havana, Susana Ferreira in Port-au-Prince and Manuel Jimenez in Santo Domingo; Editing by David Adams and Philip Barbara)