Ida dwindled to a tropical depression on Tuesday after crawling ashore in Alabama from the Gulf of Mexico, and oil operations in the Gulf were returning to normal after being widely disrupted by the storm.

"Ida has lost tropical characteristics and its winds are expected to slowly diminish during the next day or so," the Miami-based National Hurricane Center (NHC) said.

Ida's winds had decreased to near 35 miles per hour (55 kilometers per hour) and the NHC said all storm warnings had been discontinued.

The weakened weather system moved rain over Birmingham, Alabama and Atlanta but was forecast to weaken further as it turned east over northern Florida.

The storm on Monday had shut down almost 30 percent of Gulf of Mexico oil output, but energy experts predicted that by the end of Tuesday or early Wednesday there would be normal operations across the Gulf production region.

Operations at the giant Louisiana Offshore Oil Port (LOOP) should return to normal by late Tuesday or early Wednesday, a spokeswoman for the facility said.

Other companies were returning workers to platforms in the Gulf of Mexico that had been evacuated during Ida's passage.

Oil prices had eased to about $79 a barrel after Ida was downgraded from a Category 2 hurricane but rose above $80 on Tuesday due to the curtailed output resulting from the storm.

Floods and mudslides triggered by Ida were blamed for causing 130 deaths in El Salvador over the weekend as it trekked northward toward the Gulf of Mexico.

After heavier rainfall overnight, residents of Mobile reported only light rain and winds on Tuesday. Some tunnels and causeways were temporarily closed by minor flooding.

'NOT MUCH TO THIS'

But inhabitants of the southern Alabama city shrugged off the effects of Ida.

"I've got to go check on my mom ... but there's just not much to this. We got a lot worse over the summer and that wasn't even tropical weather," said Gerald Parker as he sipped coffee at a gas station.

Most local schools remained closed.

Alabama Power said initially on Tuesday they had about 3,800 customers without power -- many on Dauphin Island off Mobile, which caught the brunt of Ida's landfall -- but they expected outage numbers to decline as the weather system moved toward Florida.

Ida, downgraded from a hurricane to a tropical storm on Monday, posed the first real threat of the 2009 Atlantic hurricane season to Gulf of Mexico oil and natural gas production and forced some companies to shut down offshore platforms and evacuate personnel.

The U.S. Minerals Management Service had said Ida shut down 29.6 percent of Gulf oil production and 27.5 percent of gas output.

A quarter of U.S. oil and 15 percent of its natural gas are produced from fields in the Gulf, and the coast is home to 40 percent of the nation's refining capacity.

Energy markets have been hypersensitive to Gulf storms since the devastating 2004 and 2005 seasons, when Katrina and other storms disrupted U.S. output and sent pump prices soaring.

(Additional reporting by Jose Cortazar and Michael O'Boyle in Cancun, Nelson Renteria in San Salvador, Ivan Castro in Managua, Erwin Seba in Houston; Pascal Fletcher in Miami, Writing by Pascal Fletcher; Editing by Paul Simao)