It would normally be considered your garden-variety tropical disturbance, plodding through the Caribbean, except for one thing – it holds potential to strengthen into a tropical storm and churn into the BP oil spill.
If that were to happen, oil would likely be sprayed miles inland, damaging homes and businesses and further contaminating vegetation and waterways. It would extend the turmoil in the struggling fishing and tourism industries.
It could also impact Florida if it intensifies into a hurricane, as a powerful system could push the slick farther to the east.
On Wednesday, the tropical wave, which has been fluctuating in strength over the past few days, was centered near Haiti, moving northwest at 10 mph toward the Gulf of Mexico. Forecasters gave it a 30 percent chance of developing into a tropical depression or storm over the next two days.
Some computer models aim it generally toward the Deepwater Horizon blowout and the National Hurricane Center said it is moving into a more favorable environment to strengthen. While chances are low, it could grow into a hurricane.
But there are just too many "ifs" right now to say whether the system will actually become strong enough or draw close enough to impact the slick, said hurricane center spokesman Dennis Feltgen.
"Some of computer models do try to develop this into a tropical depression. But beyond that, it's way too early to speculate," he said.
Forecasters should have a better idea of what the system might do by Friday, when it should be in the western Caribbean.
Some experts, including those at the National Oceanic and Atmospheric Administration – which oversees the hurricane center – have detailed the possible consequences of a hurricane moving into the Gulf later in the storm season.
NOAA said the oil would have little or no influence on a hurricane's strength or track, as such storms are too large and powerful. The agency said oil likely would pushed ashore, but how much and where would depend on the storm's size, strength and the angle it approaches the slick.
A hurricane passing to the west of the slick likely would drive oil to the coast, as a hurricane's winds rotate counter-clockwise. If a storm passes to the east, the oil likely would be pulled away from the coast, NOAA said.
Jeff Masters, chief meteorologist of Weather Underground, an online weather site, paints a much bleaker picture.
If a hurricane hits that area of the Gulf and then strikes land, high winds and storm surge likely would carry the oil far inland and coat an expansive stretch of shoreline, he said.
"We can anticipate that a hurricane passing over the oil spill will be able to hurl oil and toxic dispersants many miles inland during landfall," he said.
Masters, who has been following the Gulf disaster in his blog, said winds alone could deliver oil to hundreds of square miles that otherwise might not be affected.
That was seen in the Exxon Valdez disaster in March 1989. Crews were initially able to contain the tanker spill with booms until a powerful storm roared in with 70 mph winds, he said.
"The oil went on to foul over 400 miles of Alaska coast, a far larger disaster than would have occurred than if the storm had not passed by," Masters said.
Perhaps the biggest problem: A hurricane would delay the process to stem the leak by holding up the installation of relief wells, and could damage BP's containment system, he said.
"The current containment system at the blowout location cannot handle a hurricane," he said. "It is rigidly fixed in place, and cannot flex to handle a hurricane's waves."
Masters noted that a hurricane has never passed over a massive oil spill before, so what actually would happen is uncertain.
The closest call: For 10 months, starting in June 1979, Ixtoc, an exploratory oil well, dumped 126 million gallons of oil into the Southern Gulf of Mexico. In September of that year, Category 1 Hurricane Henri swirled just north of the spill, producing high seas and gale force winds.
The wind converted the oil into a thick "mousse," he said, but the hurricane also scrubbed clean some oil-fouled beaches. NOAA found Henri's winds didn't blow long enough to influence the direction of that spill.
NOAA said a change in currents has greatly reduced the risk of oil reaching the Keys. The latest trajectory maps put the slick no closer than 385 miles from Key West.
However, that could change if a hurricane's winds blow strong and long enough, experts said. Potentially, the oil could end up in the loop current and be carried around the tip of the state and along the East Coast.
"All bets are off with a hurricane," Masters said.
He said that because of currents, it would take "just the right hurricane" to drive oil to the Keys. However, in September the currents likely will create a "relatively clear path for oil to follow to the Keys."
Both Masters and NOAA scientists say a hurricane would not result in oil mixing in with rain.
"Hurricanes draw water vapor from a large area, much larger than the area covered by oil, and rain is produced in clouds circulating the hurricane," NOAA said.