Forecasters expect Alex to grow to hurricane strength later Tuesday over the southwestern Gulf on track for the Texas-Mexico border region and away from the oil spill area off Louisiana. But it will blow waves and stormy winds all the way to the open Gulf, where BP PLC is working to cap and contain the oil, and the coastal waters tinged with crude.
The effects may be mixed.
Waves churned up by Alex -- as high as 12 feet -- could help break up the patches of oil scattered across the sea. The higher-than-normal winds that radiate far from the storm also could help the crude evaporate faster.
"The oil isn't in one solid sheet. It's all broken up into patches anyway. It will actually work to break those patches down," said Piers Chapman, chairman of the oceanography department at Texas A&M University.
But skimming vessels may be idled because they can't operate in such swells. Floating oil-containment booms could be rendered useless by waves slopping over them and may have to be pulled out of the water.
Pulling boats and crews off the water could cost precious time, said Nancy Kinner, co-director of the Coastal Response Research Center at the University of New Hampshire. Equipment has to be stripped down, packed and protected from the force of the storm, and then has to be reassembled and deployed again, she said.
But Coast Guard Adm. Thad Allen, the federal government's point man for the spill response, said the storm wasn't expected to affect two relief wells being drilled, considered the best hope of plugging the leak.
Even 12-foot waves aren't enough to stop the tanker that is sucking up large quantities of oil through the cap on the well, or a second vessel that is burning off hundreds of thousands of gallons at the surface, Allen said.
Forecasters said Alex could bring havoc to the coastline along the U.S. and Mexico.
A hurricane warning was posted for the Texas coast from Baffin Bay, 100 miles (160 kilometers) south to the mouth of the Rio Grande river; and for an additional 225 miles (360 kilometers) south to La Cruz, Mexico. Except for the border area itself, both regions are lightly populated.
Workers along the South Texas coast were clearing drainage ditches, filling sandbags, positioning heavy equipment and water pumps, and preparing emergency shelters. Some cities also handed out sandbags to residents and urged people to make preparations.
Forecasters said rain from Alex would keep falling on southern Mexico and Guatemala into Tuesday, raising the possibility of life-threatening floods and mudslides.
Meanwhile, Louisiana Gov. Bobby Jindal said Monday that the weather could push the oil farther into the ecologically delicate Barataria Bay, home to a diverse group of wildlife.
Other officials echoed that worry. Rough seas already have forced barges to leave their posts as a barrier against the oil near the bay.
"We've already lost over 68 days of decent weather and this is going to be an active hurricane season," Jefferson Parish Council Chairman John Young said Monday. "They're going to start coming yet there continues to be a lack of a sense of urgency."
Farther away Tuesday morning in Pensacola Beach, Fla., winds and surf weren't yet strong enough to keep bull dozers and sand-raking machines from cleaning the beaches ahead of Vice President Joe Biden's visit later in the day. Officials said they are preparing for the busy July Fourth holiday weekend.
For now, Alex is on track to make landfall with hurricane-force winds near the U.S.-Mexico border, possibly by Thursday.
"We are watching very, very closely," Allen said. "As it stands right now, absent the intervention of a hurricane, we're still looking at mid-August" for completing the relief well. Earlier Monday, a BP executive said the well would be done by early August.
All of the uncertainty of what Alex and other storms could do to BP's containment effort gave new urgency to the company's efforts to make its operations at the well as hurricane-resistant as possible.
The company said it hopes to install a new oil-capturing system by next week that would allow BP to disconnect the equipment faster if a hurricane threatens and hook it back up quickly after the storm passes. Right now, BP would need five days to pull out if there is a hurricane. The new system being developed, which uses a flexible hose, would cut that to two days.
The containment system now in place is capturing nearly 1 million gallons per day from the well, which is spewing as much as 2.5 million gallons a day, according to the government's worst-case estimate.