The busted well will remain capped if ships evacuate the Gulf of Mexico due to a tropical depression that could turn into a storm as it is moves toward the well site, National Incident Commander Thad Allen told reporters Thursday.
"The decision has been made to leave the cap on even if the well is unattended," Allen said, adding another decision would be made as early as 8 p.m. ET about potentially evacuating ships from the site.
"While this is not a hurricane, this storm could have some significant impacts," he said.
Meanwhile, a third of federal waters in the Gulf that were closed due to the oil spill are being reopened Thursday, the federal government said. Most of the 26,388 square miles are off west Florida.
"We haven't pulled back any of the vessels but we are monitoring the weather because we have to assure the safety of our responders," Coast Guard Chief Petty Officer Robert Lanier said earlier Thursday.
The tropical depression is producing clusters of thunderstorms across the southeastern Bahamas, Hispaniola, Puerto Rico and the Virgin Islands, Kristina Pydynowski, senior meteorologist for AccuWeather.com said.
The storms are expected to spread over more of the Bahamas and eastern Cuba Thursday then reach Florida's southeast coast tonight.
Meteorologists are forecasting the system to head toward the northern Gulf Coast and the oil spill this weekend.
"The biggest legacy of this will probably be pockets of heavy rain. It will come in waves," said Tom Moore, lead meteorologist from The Weather Channel. "It is moving along fast enough that they are going to feel the effects in southern Florida between midnight and dawn. You will get gusty winds at times and heavy rain."
BP placed a temporary plug called a storm packer inside the relief tunnel Wednesday, in case it has to be abandoned until the storm passes.
"We haven't completely stopped operations on the relief well, but we've put this basically this plugging device in to hold what we've got right now pending the decision on whether or not we can remain on scene, " Allen said Wednesday. "If we remain on scene, we'll remove that device and go on and proceed to lay the casing.
The energy giant is waiting for approval from Allen to begin a procedure known as "static kill" that involves pouring mud into the top of the well.
"We need to have the weather window happen for us and then if we had approval to move forward with the "static kill," that could happen in very quick sequence," BP senior vice president Kent Wells said Wednesday. "This all hinges on the weather."
BP is also waiting for a long enough weather window to resume work on its relief well, now four feet horizontally from the well. "We have 100 plus feet to drill before we can intercept the well," he said.
Allen told reporters Wednesday that if the work crews are evacuated, it could take 10 to 14 days before they could resume the effort to kill the well.
"That is the longest case scenario. We are evaluating whether or not we will have to do that based on the storm track," Allen said.