A storm system moved toward the Gulf of Mexico oil spill area Saturday, forcing response crews to head inland for safety and halting work to permanently plug the ruptured BP well.
Bonnie weakened to a tropical depression but was expected to regain strength, US forecasters said.
At 0900 GMT, the National Hurricane Center reported that Bonnie was over the eastern Gulf of Mexico, where warm waters were helping the system regain strength on its northwest path towards oil spill response operations.
Its center was located 300 kilometers (185 miles) south of Apalachicola, Florida, and 455 kilometers (285 miles) southeast of the mouth of the Mississippi River, according to the NHR.
The depression was moving west-northwest at nearly 28 kilometers (17 miles) per hour, with diminished sustained winds of 55 kilometers (35 miles) per hour, with higher gusts.
On this track Bonnie's center will move over the Gulf Saturday, and hit Louisiana in the northern Gulf Coast late Saturday or early Sunday, the NHC said.
"Bonnie could regain tropical storm strength before reaching the northern Gulf coast," the Miami-based center warned in a bulletin.
Louisiana Governor Bobby Jindal earlier issued an emergency declaration to help speed state assistance to areas in need.
Despite Bonnie slipping to depression status, tropical storm warnings remained in effect across the entire northern Gulf Coast, a 330-mile stretch from western Florida, through Alabama and Mississippi to New Orleans and the delta regions of Louisiana.
The weather Friday forced evacuation of two rigs and 11 offshore platforms involved in oil and gas operations -- about 1.7 percent of the platforms in the Gulf -- and at least 28 percent of area oil production has been halted, said the US Bureau of Ocean Energy, Management, Regulation and Enforcement.
"Vessels and drilling rigs involved in the BP oil spill response have been required to curtail or halt operations and to begin evacuations" as well, the bureau said in a statement.
BP and US officials decided to begin evacuation procedures Thursday as Bonnie headed towards the Gulf.
US spill response chief Admiral Thad Allen said Friday that officials believe they will feel the effects of Bonnie early Saturday in the oil spill area.
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