(Bloomberg) -- Within 5 days, a patch of clouds and showers over the Bahamas could become a dangerous tropical system in the Gulf of Mexico. Or it could mean a rainy, gusty day in Florida. The odds are about even.

Welcome to the game of atmospheric chess watched by the world’s weather forecasters. The U.S. National Hurricane Center on Wednesday gave the rainstorms a 60% chance of changing from a blob on the map to an actual weather system in the next five days, up from 50% earlier.

The showers and clouds are now being held back by wind shear created by an upper level low-pressure system to its west, said Jeff Masters, co-founder of Weather Underground, an IBM business, in Ann Arbor, Michigan. That’s left it a "big sloppy mess,” he said.

If the low-pressure system pulls away, and organizes into a tropical storm, it will be called Humberto, the eighth storm named across the Atlantic in a season that’s been slightly more active than the average.

Meanwhile, some forecast models keep the system and the low-pressure tied together indefinitely, limiting any movement, said Dan Kottlowski, lead hurricane forecaster at AccuWeather Inc. in State College, Pennsylvania.

“I like the idea of a 50-50 chance,” Kottlowski said by telephone. “If one is not starting to develop by Friday, then I think all bets are off.”

The U.S. has been hit by two hurricanes this year: Barry in July, and the just exited Dorian that clawed a path of destruction from the Bahamas, to the U.S. East Coast and then deep into Canada. The Bahamas are still grappling to recover from Dorian, which stalled over the island nation as a Category 5 hurricane with 180-mph winds that left scores dead and devastated Abaco and Grand Bahama islands.

If the blob over the Bahamas does develop, it’s hard to say just how strong it might become, Kottlowski said. The Gulf waters are quite warm, and last year, Micheal was able to grow from a potential storm on a Saturday to a major hurricane by Tuesday. Anyone making a guess as to the possible strength now “is very delusional,” Kottlowski said.

In addition to the system over the Bahamas, forecasters are watching a system near Barbados and a third one near Cabo Verde off of Africa’s coast.

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net

To contact the editors responsible for this story: Tina Davis at tinadavis@bloomberg.net, Reg Gale, Joe Ryan

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