Hundreds of skimming boats prepared Friday to return to calmer gulf waters in the wake of Hurricane Alex and resume cleanup of the massive BP oil spill, which scientists now predict is likely to reach the Florida Keys and Miami in the months ahead.

Using computer simulations based on 15 years of wind and ocean current data, the National Oceanic and Atmospheric Administration released a report Friday showing a 61% to 80% chance of the oil spill reaching within 20 miles of the coasts of the Florida Keys, Fort Lauderdale and Miami, mostly likely in the form of weathered tar balls.

Shorelines with the greatest chance of being soiled by oil — 81% to 100% — stretch from the Mississippi River Delta to the western Florida Panhandle, NOAA scientists said in a statement on its projections for the next four months.

Other areas of Florida have a low probability of oil hits. The Florida Panhandle has already seen tar balls wash up on beaches.

But the chances of oil reaching east-central Florida and the Eastern Seaboard are less than 1% to 20%, NOAA said. And it is “increasingly unlikely” that areas above North Carolina will be hit.

Meanwhile, officials were moving skimming vessels back to sea and were trying to protect the ecologically sensitive Chandeleur Sound area, said Coast Guard Adm. Paul Zukunft.

“It’s going to be a long weekend from an oil spill response perspective,” Zukunft said Friday. All skimming boats from Louisiana to the Florida Panhandle had been idle for three days because of dangerously high waves.

Officials hoped to move another containment ship above the gushing well by Wednesday to nearly double the 25,000 barrels of oil being recovered daily. As many as 60,000 barrels a day are spewing from the well, according to government estimates.

An operation to drill a relief well, the ultimate solution to stopping the leak, is seven to eight days ahead of its mid-August target date for completion.

But Coast Guard Adm. Thad Allen, the national incident commander, said Friday: “I am reluctant to tell you it will be done before the middle of August because I think everything associated with this spill and response recovery suggests that we should under-promise and over-deliver.”

BP and the Coast Guard worked out an agreement Friday with wildlife groups in response to concerns that sea turtles were being incinerated when oil slicks are burned. The parties agreed to convene a group of scientists to develop plans for monitoring future controlled burns, said Cathy Liss, president of the Washington-based Animal Welfare Institute, lead plaintiff in a lawsuit on the issue.

Liss said the officials also agreed to notify her group of any burns conducted after Tuesday and whether they have a biologist or other trained observer nearby to protect the turtles. Officials had halted such burns through Tuesday because of the weather.

The environmental groups had initially requested a temporary restraining order to prevent the burns.

Meanwhile, U.S. Fish and Wildlife officials were making plans to start shipping thousands of sea turtle eggs marked for collection along the shores of Alabama and western Florida to the Kennedy Space Center this month.

Starting July 12, turtle eggs will be removed from nests, placed in boxes and shipped in special climate-controlled, vibration-resistant FedEx trucks to a climate-controlled, predator-proof warehouse at the space center, Jacksonville, Fla.-based Fish and Wildlife spokesman Chuck Underwood said. Hatchlings will be released at various locations and times along the nearby Space Coast to avoid drawing predators, he said.

Federal officials also announced that stopover grounds would be created along the Gulf Coast in an effort to assist some of the millions of birds that will soon begin their fall migration.

Paul Schmidt, assistant director for migratory birds at the Fish and Wildlife Service, said it would be impossible to redirect vast numbers of migrating birds around the still-expanding oil slicks. But he said safe grounds for feeding and breeding could be created in coastal marshes and up to 100 miles inland.

He said conservation groups would work with private landowners to flood crop fields, cut out invasive plants that have overgrown some habitats and burn off some plants to open more ground for the birds.

On the economic side, new efforts were underway in the courts and Congress to deal with the financial effects of the spill.

A coalition of business groups and Sen. Mary L. Landrieu (D-La.) filed a brief urging the U.S. 5th Circuit Court of Appeals to uphold a judge’s ruling striking down the Obama administration’s six-month deep-water drilling moratorium in the gulf.

Also, a bipartisan group of Gulf Coast lawmakers launched a drive to pass a package of tax breaks to aid struggling businesses hurt by the spill.

richard.simon@latimes.com

molly.hennessy-fiske@latimes.com

Times staff writers Bob Drogin in New Orleans and Nicole Santa Cruz in Los Angeles contributed to this report.