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A rare tropical threat in November could hit the United States this weekend, amid an unusual and brutal hurricane season that shows no signs of letting up.

Tropical Depression Eighteen formed in the Caribbean Sea Monday morning and is expected to strengthen and become Tropical Storm Rafael by Monday afternoon. It will then strengthen into a hurricane by midweek as it moves over the northwestern Caribbean Sea.

Rafael is expected to storm Cuba like a hurricane and then end up in the Gulf of Mexico. From there, the storm’s final track and intensity in the Gulf and possibly along the U.S. Gulf Coast is difficult to determine with certainty because the system has just formed and is still several days away from reaching the area.

“It is too early to determine what, if any, impacts could occur,” the National Hurricane Center said. Everyone from the US Gulf Coast and the northeastern coast of Mexico will have to keep a close eye on the updates.

Early forecasts from the hurricane center show the center of the system will reach the U.S. Gulf Coast later this weekend, from the Florida-Alabama border to Louisiana. But this area could change dramatically in the coming days as the system moves through the Caribbean.

Any shift will have a significant impact on the flood threat from the storm in Florida and other parts of the Southeast. The storm will increase rainfall in these areas ahead of its possible arrival there. This means that areas that do receive rain from the storm later this week or this weekend will face a greater threat of flooding.

Five hurricanes have made landfall on the Gulf Coast this year, but it seems unlikely that this storm will be as intense as Hurricanes Helene and Milton because its strength could be hampered by Cuba’s terrain and hostile storm-disturbing winds over the Gulf .

Tropical activity typically ends in November, but the month still produces the occasional storm. However, landfalls in the US are exceptionally rare, with 98% of named storms making landfall in the US before November, according to hurricane expert Michael Lowry. The Atlantic hurricane season ends on November 30.

While the threat the system poses to the US is still uncertain, the threats are much clearer in the Caribbean early this week.

Hurricane and tropical storm warnings are already in effect on Monday for Cuba, Jamaica and the Cayman Islands. Additional warnings are likely to be issued in the coming days as confidence in the system’s ultimate strength and track grows.

The bulk of the system’s storms occurred over the Caribbean Sea early Monday morning, but torrential rain had already begun in parts of Hispaniola and Jamaica.

The system could bring heavy rainfall and flash flooding to more of the western Caribbean in the coming days. This heavy rainfall can also lead to mudslides, especially in the mountainous areas of Jamaica and southern Cuba.

Rainfall totals of 3 to 6 inches are expected for Cuba, the Cayman Islands and Haiti. Parts of Jamaica could flirt with double-digit rainfall totals.

The system could also bring strong winds, especially if it reaches hurricane strength late Tuesday or early Wednesday. A dangerous storm surge could also flood parts of the Cayman Islands and western Cuba.

CNN meteorologist Robert Shackelford contributed to this report.