Hurricane Fiona is the strongest hurricane of the Atlantic season, and now forecast models show a developing storm could become a monstrous threat to the U.S. Gulf Coast by next week.

An area of disorganized activity a couple hundred miles east of the eastern reaches of the Caribbean Sea will likely become the next tropical storm -- named Hermine -- in the next few days, maybe even the next few hours, according to the National Hurricane Center.

This small cluster of storms has meteorologists' attention because both American and European forecasting models have consistently showed them developing into a tropical system and entering into the Gulf of Mexico -- though the models don't have the best track record when forecasting that far out.

"The fact that nearly every computer model out there develops this into a westward-moving hurricane is absolutely concerning," CNN meteorologist Chad Myers said.

There's a 70 per cent chance it becomes a tropical depression within the next 48 hours, and there's a 90 per cent chance of development within the next five days, the hurricane centre says. So development is likely -- but where it's going is still somewhat up for debate.

"Well, there's a lot of uncertainty right now," Maria Torres, hurricane centre spokesperson, told CNN. "But yes, it's something that we are keeping an eye on and that we are closely monitoring as we get into the weekend and early next week."

Over the next several days, the disturbance is forecast to move west-northwestward across the southern Windward Islands -- at the Caribbean's eastern edge -- and then move toward the central Caribbean Sea later in the week, the hurricane centre said Wednesday morning.

By late next week, both models show the storm entering the Gulf of Mexico.

The American model shows the storm as a large and possibly major hurricane. It shows it making landfall in the Panhandle of Florida by September 30. The European model has it hitting the southern section of Florida a day earlier but as a much smaller but nearly as intense storm.

If the storm system makes it into the Gulf like the forecast models say, the conditions are ripe for development.

"The water is extremely warm, and the atmosphere is very conducive for rapid development," Myers said.

The conditions in the Gulf of Mexico are favorable for the system to strengthen, and it will do that very rapidly, Torres told CNN.

It has been a slow start to what was forecast to be an above-average hurricane season. Only one storm has made landfall in a U.S. territory, and no hurricane has made landfall or threatened the contiguous United States.

Now, a week past the peak of hurricane season, the tropics seem to have woken up, and forecasters are concerned people have let down their guard.

"After a slow start, the Atlantic hurricane season has ratcheted up quickly," Phil Klotzbach, research scientist at Colorado State University (CSU), tweeted.

"People tend to lower their guard and think, oh, yeah, we're out of the woods," Torres said. "But in reality, the season continues. We are still in September; we still have October to go. Anything that forms over either the Atlantic or the Caribbean is something that we need to keep monitoring very closely."

The Atlantic hurricane season ends November 30.

Four times a day, the American forecast model and the European model spit out an updated forecast. And after each run, meteorologists will tweet what they think will happen.

No matter what, if you live in the Caribbean, Florida and other states along the Gulf Coast, pay attention and watch what the National Hurricane Center says once the storm is strong enough to be named. The track that it issues at that time will give an increasingly good indication of what is most likely to happen.