BP says the relief well rig and other vessels are returning to the blown-out oil well site after Tropical Depression Bonnie begins to break apart, and with winds near 30 mph the storm could soon weaken to an area of low pressure.
Forecasters with the U.S. National Hurricane Center said Saturday that it was less likely that Bonnie would strengthen as the storm heads toward the site of the oil spill in the Gulf.
"The Development Driller 3 (DD3) is on its way back," BP spokesman Bryan Ferguson said. "It's the one that's drilling the first relief well, and it's the most critical one and it is turned around and is headed back right now."
The rig was disconnected from the spill site ahead of Tropical Storm Bonnie, which later weakened to a tropical depression.
"The assessment was made that the storm intensity has decreased," Ferguson said. "So the decision was made overnight to return the DD3."
In anticipation of the storm, ships working at the oil spill site moved to safer waters and coastal workers packed up oil removal operations.
The storm now seems a less likely threat to cleanup, but is expected to bring periods of heavy rainfall, strong winds, and dangerous surf to the Gulf states. Bonnie could reach the northern Gulf Coast tonight or early tomorrow after passing over the oil spill midday Saturday.
The center of Bonnie came ashore Friday near Cutler Bay, about 20 miles south of Miami. It moved into the eastern Gulf and was about 215 miles east-southeast of the mouth of the Mississippi River at 8 a.m. EDT Saturday.
Though officials along the coast expressed frustration at the sudden halt to cleanup and containment, several said they saw no choice, given the looming arrival of bad weather.
The mechanical cap that has mostly contained the oil for eight days was left closed, and there was no worry the storm could cause any problems with the plug because it's nearly a mile below the ocean's surface.
"Preservation of life and preservation of equipment are our highest priorities," said Allen, the federal government's spill chief who ordered the evacuation of most ships 40 miles from the Louisiana coast
With many of the protective barriers that had been shielding Louisiana's coastal marshes locked away in warehouses, oil began to seep into fragile ecosystems that had been relatively unscathed; the black blotches were visible in the waters off St. Bernard Parish, just east of New Orleans's French Quarter, The Wall Street Journal reported.
"We can't do anything about it," said parish spokeswoman Jennifer Belsom about current skimming operations. But she expects them to resume Monday.
Workers on land readied for a possible storm surge that could push oil into the sensitive marsh areas along the coast.
On the tiny resort island of Grand Isle off the southeast Louisiana coast, workers packed up the oil removal operation, tearing down tents, tying down clean boom and loading oil-soaked boom into large containers so it won't pollute the area if the storm causes flooding.
"We're planning for a 2-to-3-foot storm surge so anything that would be affected by that is being moved or stored," said Big Joe Kramer, 55, who is working on his fourth large spill for Miller Environmental Services, Inc.
At the spill site, the water no longer looks thick with gooey tar. But the oil is still there beneath the surface, staining the hulls of boats motoring around in it.
The evacuation could delay the relief well for as long as two weeks, pushing back the attempt to definitively shut down the leak by intercepting the well to late August, BP officials said. But an attempt to flood the well with drilling mud and cement could be tried shortly after the ships get back to the drilling site, Allen said.
Before the cap was attached and closed a week ago, the broken well spewed 94 million gallons (355 million liters) to 184 million gallons (696 million liters) into the Gulf after the BP-leased Deepwater Horizon rig exploded April 20, killing 11 workers.
The plug is so far beneath the ocean surface, scientists say even a severe storm shouldn't damage it.
"There's almost no chance it'll have any impact on the well head or the cap because it's right around 5,000 feet (1,500 meters) deep and even the largest waves won't get down that far," said Don Van Nieuwenhuise, director of professional geoscience programs at the University of Houston.
The Associated Press contributed to this report.