More tropical trouble brewing for southeast US via Caribbean, Gulf

Conditions remain ripe for tropical development in the western Caribbean and the Gulf of Mexico over the next week and steering breezes would tend to guide any feature that forms in those waters toward the United States.

AccuWeather meteorologists say the area from the western Caribbean to the Gulf of Mexico will remain a potential tropical development zone into the first half of October. Over the next week, one to two tropical storms could be born in this zone and possibly steered across part of the southeastern United States that was hit hard by Hurricane Helene.

"A zone of low pressure will form across the western Caribbean, accompanied by clusters of tropical downpours and thunderstorms over the next several days," AccuWeather Meteorologist Alyssa Glenny said, adding, "This feature will shift into a zone with decent prospects for tropical development with abnormally warm ocean waters and where pockets of limited disruptive breezes (wind shear) are currently low. Due to these factors, our team of expert meteorologists is highlighting a high risk for tropical development."

Wind shear will remain low initially but will tend to increase over the Gulf of Mexico later in the week. As these southwesterly breezes increase, they will tend to cause moisture and any tropical feature that has formed or is trying to form to be guided to the north or east later next week into the following weekend.

The exact strength and direction of the wind shear will tend to determine where downpours and gusty winds will be guided by any budding tropical feature(s).

Downpours will flourish in the vicinity around the western Caribbean and southern Gulf of Mexico this week.

Later on, the downpours can be strewn anywhere from Louisiana to Florida, Georgia and the Carolinas in the U.S.

Should steering breezes remain weak, then a track toward Louisiana could occur. Should strong steering breezes from the southwest occur, then a track toward Florida and perhaps the coastal areas of Georgia and the Carolinas would be more likely.

Perhaps not another Helene, but there is a tropical threat with impacts brewing

There will be significant differences between this new tropical threat and what was Helene.

"Helene was a large tropical disturbance that moved into a highly conducive environment for rapid strengthening. In addition to the very warm water, there was very little wind shear in front of Helene," AccuWeather Senior Meteorologist Brett Anderson said.

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A non-tropical storm also dove southward through the central U.S., providing additional energy to Helene and helping to send it northward into the southern Appalachians and then westward toward the mid-Mississippi Valley.

"This week's disturbance will likely be slow to develop as it expands northward, encountering more land masses and wind shear," Anderson explained, "There will also not be any storm diving southward through the central U.S. to provide that extra energy and northward pull."

The most likely scenario with this week's tropical feature is that it will get drawn northward to a point over the Gulf but then shunted northeastward late this week.

Any tropical feature that grabs Gulf of Mexico and Caribbean moisture and brings it along has the potential to cause excessive rain and flooding. Perhaps the highest risk for significant and possibly excessive rainfall will be across Florida, but this is subject to change.

"The anticipated stiffening southwesterly wind shear may prevent this storm from rapidly strengthening and may even split it apart into two separate entities--the second one may follow the first one a few days later," Anderson said, "If this first tropical feature can fight off the wind shear, then it will have the potential to be a bigger, more compact storm and could prevent the formation of the second feature."

A strong and more compact storm would result in a risk of strong and potentially damaging winds across parts of the Southeast from Friday through next weekend.

Both scenarios--one strong storm or two weaker ones--can deliver excessive rainfall to part of the Southeast.

Elsewhere in the Atlantic

Isaac, which became a hurricane late this past week, will travel over open waters of the North Atlantic south of Iceland and west of the United Kingdom this week. It remains a concern for cross-Atlantic shipping and cruise interests.

Thousands of miles farther to the south over the central Atlantic, Tropical Storm Joyce is forecast to remain at sea while dissipating slowly this week.

A bit to the south of where Joyce is currently located, one to two areas of low pressure have the potential to evolve into a tropical feature over the next several days.

It is possible that one of these may wander close to the islands in the northeastern Caribbean toward the second week of October.

The next names on the list of tropical storms for the 2024 Atlantic hurricane season are Kirk, Leslie and Milton.

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