Aug. 29 (Bloomberg) -- Gustav returned to hurricane strength after it moved west of Jamaica with torrential rain today, picking up speed as it headed toward Cuba and the U.S. Gulf Coast cities ravaged by hurricanes Katrina and Rita in 2005.

Cuba issued a hurricane warning for its western areas, which the U.S. National Hurricane Center forecasts Gustav will hit tomorrow. The storm may then reach central Louisiana as a hurricane on Sept. 2 before moving northwest into other areas of Louisiana and Texas, the center forecast.

President George W. Bush declared a state of emergency for Louisiana, three years to the day after Katrina left more than 80 percent of New Orleans under water and caused more than $81 billion in damage. That hurricane was followed three weeks later by Rita, which ravaged central Louisiana and parts of eastern Texas, the same areas now threatened by Gustav.

``A land strike to the west of New Orleans will place this great city within the most dangerous part of the storm,'' said Jim Rouiller, a senior energy meteorologist with Planalytics Inc., a forecaster based in Wayne, Pennsylvania. ``Gustav has the potential to generate much more damage than Katrina did.''

Storm Watch

Gustav will ``likely explode into a major hurricane over the next two days as it tracks on a west to northwesterly course across the northwestern Caribbean toward western Cuba and the Cayman Islands,'' said Rouiller.

Parts of the Florida Keys were put under a storm watch late today. Hurricane warnings were posted for the Cayman Islands and western Cuba, including the capital Havana.

Bush ordered federal aid to supplement state and local efforts, the White House said by e-mail. Texas, Mississippi and Louisiana issued their own state emergency and disaster declarations and alerted National Guard units.

New Orleans Mayor C. Ray Nagin urged an estimated 30,000 residents needing assistance to register with a program to help them get out of the city if Gustav strikes. New Orleans will assist residents who need help leaving at 8 a.m. tomorrow, according to a statement. Louisiana has about 800 buses mustered for a possible evacuation; Amtrak trains are also available if needed.

``We have to take these storms seriously,'' Governor Bobby Jindal said at a news conference yesterday. ``We as Louisianans have to be better prepared.''

First Test

Gustav will be the first test for federal officials of new procedures since Hurricane Katrina, Homeland Security Secretary Michael Chertoff said in Washington yesterday before flying to Louisiana. The Bush administration was widely criticized for a slow response after the 2005 storm.

The U.S. Federal Emergency Management Agency said it had food, water and supplies ready to move into the area.

``The upper Texas coastline to Louisiana will remain most at risk to receive the brunt,'' Rouiller said today. ``Landfall projections into this high-risk target zone are expected to occur very late Monday night and Tuesday.''

Gustav regained hurricane strength earlier today, and had maximum sustained winds of 80 mph (129 kph) by 8 p.m. Miami time today. The storm was centered 90 miles east of Grand Cayman, the U.S. National Hurricane Center said on its Web site. It is heading toward the northwest at 11 mph.

Extensive Flooding

Gustav was predicted to bring as much as 25 inches (64 centimeters) of rain to Jamaica and the Cayman Islands on a track toward the western tip of Cuba, reaching the Gulf of Mexico by Aug. 31, the center said.

Jamaica's Office of Disaster Preparedness and Emergency Management warned of ``extensive flash flooding'' as heavy rainfall continues into the night, it said in a bulletin.

The storm led to the deaths of 51 people in Haiti, Agence France-Presse reported and at least 11 in Jamaica. In the neighboring Dominican Republic, eight people died and two were hurt in a landslide, the country's Center of Emergency Operations said on its Web site.

Some southern Louisiana parishes, where several oil refineries are located, plan to evacuate civilians today or tomorrow, the local governments said on their Web sites. St. Charles Parish, west of New Orleans, accelerated its emergency plan to begin assisted evacuations today and mandatory evacuations will likely take place at noon local time tomorrow. St. Bernard Parish officials anticipate mandatory evacuations tomorrow.

U.S. oil and gas platforms and pipelines are most concentrated in the waters south of Louisiana and east of Texas. Offshore fields in the Gulf accounted for 26 percent of total U.S. crude production and 12 percent of natural gas output in April, according to the U.S. Energy Department.

Oil Prices

Producers including Royal Dutch Shell Plc and BP Plc evacuated workers from platforms in the Gulf region.

Crude oil for October delivery fell 13 cents to $115.46 a barrel today on the New York Mercantile Exchange. Futures are up 57 percent from a year ago.

The hurricane center also is monitoring Tropical Storm Hanna, which was about 280 miles north-northeast of San Juan, Puerto Rico and heading west-northwest at 10 mph as of 5 p.m. Miami time. The system had maximum sustained winds of 50 mph, and may become a hurricane over the weekend, the center said.

Hanna is predicted to turn west and then southwest toward the central Bahamas next week. Landfall isn't forecast over the next five days, according to the center's Web site.

To contact the reporter on this story: Robin Stringer in New York at rstringer@bloomberg.net.

Last Updated: August 29, 2008 20:45 EDT